text:
\section{Introduction}
Asphaltene plays an important role in energy sector through production, refinery, and transportant to value-added product from hydrocarbon-rich waste \cite{gray2015upgrading}. As a complex mixture containing polycyclic aromatic hydrocarbons, asphaltene is defined by solubility class that is soluble in aromatic solvents such as benzene and toluene and insoluble in n-alkanes solvents such as n-pentane and n-heptane \cite{schuler2015unraveling}. On one hand, the presence of asphaltene hinders the coalescence of oil-water emulsions \cite{mao2019novel,ma2020novel}, causing increase in operational cost and production challenges by forming flocculation and deposits in the reservoirs and transportation pipes. Undesirable asphaltene precipitation in the transportation pipes can cause severe problems such as clogging and blocking \cite{keshmiri2019microfluidic,zi2021investigation}. \textcolor{black}{On the other hand, dilution-induced asphaltene precipitation has been utilized in paraffinic froth treatment (PFT) units to remove impurities in bitumen such as water and solids. In this process, the particle size of asphaltene precipitates plays an important role, as they interact and agglomerate with water droplets and solid particles \cite{rao2013froth}.} The precipitated asphaltene can be used as a raw material to make value-added products, such as absorbent, or carbon fibers \cite{plata2022characterization,tehrani2019novel,alivand2019tuning,saad2022transformation}. Therefore, it is of importance to understand and control asphaltene precipitation.

Asphaltene is considered to form nano-aggregates and nano-clusters in a crude oil or aromatic solvents, unless at high dilution \cite{yarranton2013size,mullins2010modified,elkhatib2019nanoscale,zhao2007composition,eyssautier2012mesoscale}. Asphaltene dispersed in toluene is more stable due to the balance of attractions (van der Waals, H-bonding, and acid base interactions) and steric repulsions originated from side alkane chains \cite{gray2011supramolecular,da2012density}. Adding n-alkanes such as paraffinic solvents into the mixture of asphaltene and toluene leads to the collapse of the side alkane chain layer and a reduction in steric repulsion. Consequently, asphaltene nano-aggregates grow to a larger size and manifest as precipitates or aggregates \cite{wang2010interaction,wang2009colloidal}. The effective parameters that may affect asphaltene precipitation include temperature \cite{peramanu1999flow}, pressure \cite{akbarzadeh2005generalized}, addition of inhibitors \cite{alemi2021experimental}, solvent to bitumen (S/B) ratio \cite{rogel2017effect,hristova2022asphaltene}, and type of the solvent \cite{alboudwarej2003regular}.

Recently, the effect of mixing conditions on asphaltene precipitation has attracted the attention of researchers to understand aggregate formation \cite{rahmani2003characterization, rahmani2004evolution,boek2010multi,boek2008deposition,ali1998effect}. In a conventional bulk system, when crude oil and paraffinic solvents were added into a container and mixed by a mixer, the resulting shear force caused by the agitation enhanced the growth rate of asphaltene particles, but the final size of the asphaltene particles was found to be smaller \cite{rahmani2003characterization, rahmani2004evolution}. The increase of the flow rate helped to increase the rate of deposition but the thickness of the final deposit layer was reduced \cite{boek2010multi,boek2008deposition,ali1998effect}.

The influence of mixing dynamics on asphaltene precipitation is mainly from two aspects. The impact of shear force on asphaltene aggregation and fragmentation \cite{rahmani2005online,rastegari2004kinetics,elkhatib2019nanoscale,nguyen2021effect} and the variation in local compositions triggering asphaltene precipitation \cite{shalygin2019spectroscopic,morozov2017reversibility,buckley2006mixing,durand2010effect}. Extensive studies have been carried out to predict the deposition. However, there are knowledge gaps in the dynamics of dilution-induced asphaltene precipitation at the early stage. Importantly, the effects of local flow concentration and convection on asphaltene precipitation are challenging due to the poor mixing control. On the other side, the sampling procedures make it impossible to control convection. The results obtained from the direct visualization of asphaltene particles at a submicron scale may not be sufficient to investigate early-stage asphaltene precipitation due to the limited resolution of conventional optical microscopes. Microfluidic devices have been applied in the study of asphaltene precipitation with high reproducibility of results \cite{mozaffari2021lab,pagan2022physicochemical}. For example, understanding the characteristics of the precipitates from mixing in confined spaces \cite{meng2021primary,meng2021microfluidic,meng2022size}.

Solvent exchange, also called solvent shifting or solvent displacement has shown promising results in a quantitative understanding of solvent-induced phase separation \cite{Zhang9253}. Controlled mixing by solvent exchange has led to fundamental insights into phase separation induced by dilution, including nanobubble and nanodroplet formation \cite{peng2018growth,meng2020viscosity}, oiling out crystallization \cite{zhang2021oiling,choi2021effects}, and polymer nanoprecipitation \cite{zhang2012flash}. The approach of solvent exchange is displacing a solution in a good solvent with a poor solvent. Consequently, the new phase nucleates and grows at the mixing front due to a transient oversaturation \cite{dyett2018growth}. The solvent exchange process is a well-controlled mixing system, which can be described by the advective diffusion equation \cite{Zhang9253}. Overall, the diffusive and convective mixing in the system is controllable by varying the dimension of the microfluidic chamber and the injection rate of the solvents. To the best of our knowledge, such fundamental studies on asphaltene precipitation are not yet reported in the open literature. In particular, the orientation and channel height of the chamber, the flow rate of the mixing, and the operating temperature can dictate the final morphology of asphaltene precipitates in terms of surface coverage ($SC$) and size distribution at the submicron and micron scales.

This research aims to understand the solvent-induced asphaltene precipitation under controlled convective mixing. The microfluidic flow rate, microchannel height, and orientation all enable the control of local concentration of the solvent and local shear force in the experiments. Systematic numerical investigations based on the finite element method (FEM) were performed to visualize the oversaturation pulse in the solvent exchange process for different geometric and flow conditions. Through the numerical results, we identified the generation of convective rolls when the channel height was more than a critical value due to gravity and buoyancy forces. Furthermore, the total internal reflection fluorescence microscope (TIRF) and optical microscope are used to resolve the asphaltene particles at the submicron and micron scales. In this work, the surface coverage ($SC$) is characterized to quantify the asphaltene yield. The size distribution at the submicron and micron scales is specified to investigate the aggregation of asphaltene particles. The implication is that the optimized flow condition may mediate the asphaltene precipitation without leveraging solvents. The findings of this work \textcolor{black}{provide} new insights into the influence of mixing condition on asphaltene precipitation, and is not only applicable to asphaltene precipitation but also has implications for other dilution-induced phase separation processes.

\section{Experimental section}
\subsection{Chemical and substrate preparation}
Murphy Oil (USA) provided the C5-asphaltene (i.e., n-pentane precipitated asphaltene) used in this project. The analysis of elementary and the pre-treated method of the asphaltene sample can be found in our previous research \cite{MENG2021120584}. In brief, raw asphaltene sample was dissolved in toluene (Fisher Scientific, ACS grade, 99.9 \%+) to remove any inorganic solvents by 0.22 $\mu m$ polyvinylidene difluoride (PVDF) filter paper. A rotary evaporator was then used to remove toluene from the inorganic solid free asphaltene. 17 $g$ of inorganic solid-free asphaltene sample was dissolved in toluene to make 1 $L$ of asphaltene in toluene solution (i.e., solution A). \textcolor{black}{The results of diluted crude oil are similar to that of asphaltene in toluene solution at early stage of asphaltene precipitation \cite{meng2022size}.} n-Heptane (Fisher Chemical, 99\%) was used as the solvent (i.e., solution B) for asphaltene precipitation.

A high-precision cover glass (Azer Scientific) was used as the substrate. Before the experiment, the cover glass was sonicated in toluene for 5 min and dried by air to remove any contaminates.

\subsection{Solvent exchange process}
The solvent exchange process was performed in a custom-built microchamber. \textcolor{black}{The experiments were performed at ambient pressure, as the current design of microfluidic chamber did not allow for varying the pressure.} The apparatus is shown in Figure \ref{chamber_5}(a). The micro-channel was 35 $mm$ long and 5 $mm$ wide. Glass was used as a top wall and a spacer in between the glass and substrate was used to seal the system. The channel height was adjusted by using spacers of different thickness.

\begin{figure}[ht]
\centering
\includegraphics[width=1\columnwidth]{chamber5.jpg}
\renewcommand{\captionfont}{\linespread{1.6}\normalsize}
\caption{(a) Sketch of the microchamber used in this study. (b) Zoomed-in image of the mixing front in (a). The flow direction is along the x-axis. The microchamber is placed (c) horizontally, (d) vertically to examine the effect of orientation.}
\label{chamber_5}
\end{figure}

The model oil (solution A) was first injected into the microchamber using a syringe pump (NE-1000, Pumpsystems Inc.). Afterwards, n-heptane (solution B) was injected into the device to displace solution A, creating a mixing front between solution A and solution B as shown in Figure \ref{chamber_5}(b). The asphaltene precipitation began at the moment when the concentration of n-heptane is higher than the onset point in the mixing front. At the moment, the solution A was completely displaced by solution B, asphaltene precipitation stopped due to lack of dissolved asphaltene. After injecting 2.5 $mL$ of solution B (i.e., at least ten times the total volume of solution A), the asphaltene precipitation was considered the final state. Air was injected into the chamber to drive away from the remaining liquid. After the solvent exchange process, the liquid was removed with a 5 $mm/s$ of a constant air flow velocity, in all of the experimental conditions. Subsequently, the substrate was examined by the microscopes. The microchamber was placed both horizontally (Figure~\ref{chamber_5}(c)) and vertically (Figure~\ref{chamber_5}(d)) to examine the gravitational effect.

\subsection{Effect of flow rate, channel height, orientation, and temperature}
This work investigated the influence of four aspects on asphaltene precipitation that include injection flow rate of solution B, channel height, orientation of the microfluidic chamber, and temperature. A horizontally placed 1,000 $\mu m$ height microfluidic chamber was used to study the influence of flow rate under the ambient condition (i.e., 19 - 21$^{\circ}$C, 1 $atm$). The flow rate of solution B was varied from 15 $mL/h$ to 150 $mL/h$. The Reynolds number ($Re$) and P\'{e}clet number ($Pe$) were calculated from $Re = \frac{Q}{w \upsilon}$ and $Pe = \frac{Q}{wD}$, respectively \cite{Zhang9253}, where $Q$, $w$, $\upsilon$, $D$ are the microfluidic flow rate, width of the microchamber, kinematic viscosity, and diffusion coefficient, respectively. Table \ref{table 2} summarizes the flow rate and the corresponding $Re$ and $Pe$.

\begin{table}[ht]
\captionsetup{font=normalsize}
\renewcommand{\captionfont}{\linespread{1.6}\normalsize}
\centering
\caption{Flow rate and the corresponding Reynolds number and P\'{e}clet number in the experiments.}
\label{table 2}
\begin{tabular}{|c|c|c|}
\hline
\multirow{2}{*}{Flow Rate (mL/h)} & \multirow{2}{*}{Reynolds Number} & \multirow{2}{*}{P\'{e}clet Number} \\
 &  &  \\ \hline
15 & 1.37 & 458 \\ \hline
30 & 2.73 & 916 \\ \hline
60 & 5.47 & 1,832 \\ \hline
90 & 8.20 & 2,747 \\ \hline
120 & 10.94 & 3,663\\ \hline
150 & 13.67 & 4,579 \\ \hline
\end{tabular}
\end{table}

Seven spacers of different thickness from 90 $\mu m$ to 1,000 $\mu m$ were used to investigate the effect of channel height. The buoyancy and gravity effects of different channel heights can be estimated by a dimensionless number, Rayleigh number ($Ra$), as shown in Equation (\ref{Ra}) \cite{Zhang9253}. Table \ref{table 1} showed the corresponding Rayleigh number of each channel height.

\begin{equation}
\label{Ra}
Ra=\frac{\Delta \rho g (h/2)^3}{\mu D}
\end{equation}
where $\Delta \rho$ is the density difference between solution A and solution B, $g$ is the gravitational constant, $h$ is the channel height, $\mu$ is the viscosity of solution B, and $D$ is the diffusion coefficient.

\begin{table}[ht]
\captionsetup{font=normalsize}
\renewcommand{\captionfont}{\linespread{1.6}\normalsize}
\centering
\caption{Channel height and the corresponding Rayleigh number in the experiments.}
\label{table 1}
\begin{tabular}{|c|c|}
\hline
\multirow{2}{*}{Channel Height ($\mu m$)} & \multirow{2}{*}{Rayleigh Number} \\
 &  \\ \hline
90 & 219 \\ \hline
180 & 1,753 \\ \hline
260 & 5,283 \\ \hline
340 & 11,814 \\ \hline
430 & 23,899 \\ \hline
510 & 39,873 \\ \hline
\end{tabular}
\end{table}

To study the influence of chamber orientation, the device filled with solution A was placed horizontally and vertically (Figure \ref{chamber_5}(c)-(d)). Solution B was then injected at 30 $mL/h$.
Four elevated temperatures of 35 $^{\circ}$C, 50 $^{\circ}$C, 58 $^{\circ}$C, and 65 $^{\circ}$C were compared with the results of the ambient temperature. The densities, diffusion coefficients and viscosities at those temperatures are listed in Table~\ref{parameters}. All the solutions were immersed in the water bath for 30 $min$ before conducting the experiments to attain thermal equilibrium. The entire solvent exchange system, including the horizontally placed microchamber and pipes, were immersed into the water bath to keep the temperature constant during the experiments. The channel height was kept 1,000 $\mu m$ and the flow rate of solution B maintained a constant flow rate of 90 $mL/h$ for all the elevated temperatures.

\subsection{Observation and characterization of the asphaltene precipitates}
Total internal reflection fluorescence (TIRF) mode of a confocal microscope (Leica TCS SP8) was used to capture high-resolution images. A 488 $nm$ laser was used to excite the fluorophores of asphaltene. The spatial resolution was $\sim$ 200 $nm$ to show the details of asphaltene particles at the submicron scale. An optical microscope (Nikon ECLIPSE Ni) equipped with Nikon DS-FI3 camera was used to detect asphaltene particles at the micron scale. MATLAB (The MathWorks, Inc., US) and ImageJ (open source software) were used to analyze the images. The details of the process for image analysis can be found in our previous work \cite{meng2021microfluidic,MENG2021120584}. In brief, the main steps were to transform the microscopy images into binary images and then to obtain the information of particles such as perimeter and area. The particle size distribution smaller than one micron was obtained from the TIRF images, while the surface coverage and particle size distribution larger than one micron were obtained from the optical microscope images.

\subsection{Description of the numerical model}
\textcolor{black}{In the present study, Level-Set (LS) method is coupled with the Transport of Diluted Species (TDS) physics adopted to track the interface between the two fluids and the concentration of the dissolved species at the oversaturation region.  }
\subsubsection{Transport of diluted species}
The transport of diluted species model solves the chemical species transport through diffusion and convection. This method resolves the mass conservation equation for oversaturation pulse, which can be written as:
\begin{equation}
\label{eq:tdseq}
\frac{ \partial C_{i}}{ \partial t} +  \nabla.  J_{i}  +  \vec {U}. \nabla C_{i}=  0
\end{equation}
where $C_{i}$, $D_{i}$, $\vec{U}$, and $J_{i}$ are the concentration of species, diffusion coefficient, mass average velocity vector, and mass diffusive flux vector, respectively. The mass flux $J_{i}$ is further defined as $J_{i} = - D_{i} \nabla C_{i} $.

\subsubsection{Level-Set model}
A conservative level-set method \cite{sussman1994level} was combined with the transport of diluted species model to visualize the effect of gravity. In addition to the aforementioned equation for transport of diluted species, a set of coupled governing equations consisting continuity, momentum (incompressible Navier-Stokes equation), and a level-set equation was solved.
\textit{Equation of continuity:}
\begin{equation}
\label{eq:mass_eqn}
  \nabla .   \vec{ U }  =0
\end{equation}
\textit{Equation of motion:}
\begin{equation}
\label{eq:mom_eqn}
\rho \frac{ \partial ( \vec{ U })}{ \partial t} + \rho \nabla.( \vec{ U } \vec{ U }) = - \nabla P + \nabla.\mu (\nabla \vec {U} + \nabla { \vec {U} } ^{T}) + \rho g + \vec{ F}_{SF}
\end{equation}
where $\vec{U }$, $\rho $, $\mu$, $P$, and $\vec{ F}_{SF}$ are velocity, density, dynamic viscosity of fluid, pressure, and interfacial tension force, respectively.\\ \\
\textit{Equation of Level-Set (LS) Function:} \\
The interface in a level-set method is
captured by a conservative level set method (CLSM). The level function
changes smoothly across the interface from 0 to
1, when $\phi=0$, it indicates one fluid domain and $\phi=1$ in another fluid domain. The smooth interface between the phases is defined by the 0.5 isocontour of $\phi$. The following equation describes the convection of the reinitialized level set function \cite{mccaslin2014}.
\begin{equation}
\frac{\partial \phi}{\partial t}+\mathbf{u} \cdot \nabla \phi=\gamma \nabla \cdot\left(\epsilon \nabla \phi-\phi(1-\phi) \frac{\nabla \phi}{|\nabla \phi|}\right)
\end{equation}
where $\epsilon$ is a parameter to determine the thickness of the transition layer where $\phi$ goes smoothly from zero to one. It is typically of the same order as the size of the elements of the mesh. The  parameter $\gamma$ determines the amount of reinitialization of stabilization  of level set function \cite{COMSOL}. \textcolor{black}{The coupling of transport of diluted species interface with the level\textendash set physics adds an additional transport equation for computing the concentration of dissolved species "C". The convective transport of "C" is based on the velocity field from the two\textendash phase flow, level\textendash set physics.}

\subsubsection{Computational parameters, implementation and model validation}

Systematic numerical investigations were performed to understand the mixing condition during solvent exchange process inside the microchamber. Two-dimensional transient simulations were carried out using a finite element method based solver COMSOL Multiphysics V. 6.0. (COMSOL AB, Stockholm, Sweden). \textcolor{black}{Asphaltene dissolved in toluene was considered as a fluid\textendash 1 and n\textendash heptane (solvent for asphaltene precipitation) was considered as fluid\textendash 2 in the computational domain. All the details of the fluid properties (i.e., density and viscosity) corresponding to experimental conditions are provided in the supporting information in Table S1. For different temperature conditions, toluene and n\textendash heptane properties were estimated using UNIFAC thermodynamic model with the software package Symmetry \cite{package}.} Influence of different microchannel geometries (i.e., height, see Table \ref{table 1}) and various flow rates (see Table \ref{table 2}) were examined . Unsteady state diffusion equation coupled with the velocity field was solved to obtain the evolution of the mixing front with space and time \cite{C6LC01555G}. The velocity inlet boundary condition was applied to the microchannel inlet, and the pressure outlet boundary condition was used at the outlet as shown in Figure \ref{CFD model}(a).

\begin{figure}[ht]
\centering
\includegraphics[width=1\columnwidth]{cfdmodel.jpg}
\renewcommand{\captionfont}{\linespread{1.6}\normalsize}
\caption{(a) 2D schematic representation of the computational domain with imposed boundary conditions, and (b) computational gird. (c) Influence of grid numbers on the inlet velocity profiles along the height of the channel. (d) Model Validation with the experimental results reported in our previous work \cite{wei2022interfacial}. Blue circles and yellow squares represent the experimental data. Pink and red dashed lines represent the numerical results from our model for the same system.}
\label{CFD model}
\end{figure}

\begin{table}[ht]
\captionsetup{font=normalsize}
\centering
\caption{Meshes in the grid independence study}
\renewcommand{\captionfont}{\linespread{1.6}\normalsize}
\label{grid}
\begin{tabular}{|c|c|c|c|c|c|}
\hline
Grid & \begin{tabular}[c]{@{}c@{}}Total \\ number of \\ elements\end{tabular} & \begin{tabular}[c]{@{}c@{}}Number\\ of boundary\\ elements\end{tabular} & \begin{tabular}[c]{@{}c@{}}Maximum\\ element\\ size (mm)\end{tabular} & \begin{tabular}[c]{@{}c@{}}Average\\ mesh quality\\ (skewness)\end{tabular} & \begin{tabular}[c]{@{}c@{}}Difference (\%)\\ w.r.t G7\end{tabular} \\ \hline
G1 & 3,500 & 730 & 0.10000 & 1.0 & 4.06 \\ \hline
G2 & 6,552 & 978 & 0.0750 & 1.0 & 2.81 \\ \hline
G3 & 14,000 & 1,460 & 0.0500 & 1.0 & 1.76 \\ \hline
G4 & 25,218 & 1,949 & 0.0375 & 1.0 & 1.34 \\ \hline
G5 & 35,008 & 2,248 & 0.0320 & 1.0 & 0.95 \\ \hline
G6 & 56,000 & 2,920 & 0.0250 & 1.0 & 0.51 \\ \hline
G7 & 224,000 & 5,840 & 0.0125 & 1.0 & - \\ \hline
\end{tabular}
\end{table}

No-slip boundary condition was imposed at the top and bottom walls and inflow with zero concentration at the inlet. At $t=0$, the oversaturation pulse in a narrow region (i.e., 100 $\mu m$ thick) was initialized vertically along the inlet with a uniform concentration. The oversaturation pulse was convected and diffused simultaneously inside the microchannel, once the flow is initialized. The computational domain was meshed with quadrilateral mesh elements (Figure \ref{CFD model}(b)). Grid independence study was initially performed using different element sizes ranging from 0.10 to 0.0125 $mm$. Mesh quality and number of elements details are reported in Table \ref{grid}. The velocity profiles were compared for different meshes as shown in Figure \ref{CFD model}(c), and an optimum mesh element size of 0.025 $mm$ was considered for the numerical investigations. Different sets of simulations were performed in a high performance computing (HPC) facility for the same flow conditions ($Pe$, $Ra$, $Re$, $h$, and $Q$) as used in the experiments . For each simulation, 48 CPUs were used to run the 30 $s$ of flow time.

At first, the developed CFD model was validated with the relevant experimental data from our previous study \cite{wei2022interfacial}. The length, width and the height of the considered microchamber are 45 $mm$, 13 $mm$, and 0.3 $mm$ respectively, which are within the range of our current microchamber dimensions. The flow rate at the inlet was set to 50 $mL/h$ and other fluid properties were kept similar to our previous study \cite{wei2022interfacial}. Figure \ref{CFD model}(d) shows a comparison of the analyte concentration as a function of time. The CFD model predictions were found to be in good agreement with experimental data. \textcolor{black}{Therefore, the developed CFD model was capable to predicted underlying phenomena of solvent exchange process.}

\section{Results and Discussion}

In the solvent exchange process, solution B gradually displaces solution A. Simultaneously, asphaltene from solution A diffuses to solution B, and n-heptane diffuses towards solution A. As the diffusion process advances, The S/B ratio in the mixing zone gradually increases beyond the onset, until the concentration of asphaltene in the mixing front is oversaturated. At t = 0, the asphaltene in solution A is undersaturated. As time progresses, the asphaltene becomes oversaturated in the mixing region, which triggers the formation of asphaltene precipitate. Once the solution A is completely displaced by the solution B, the formation of asphaltene precipitate stops due to lack of asphaltene. The duration of the oversaturation pulse is independent of the flow velocity due to the no-slip boundary and depends on the diffusion of chemicals from the mixing front to the substrate \cite{Zhang9253}. Therefore, the new phase formation on the substrate is determined by the profile of the mixing front.

\subsection{Effect of the flow rate}

Simulation results show the oversaturation pulse profile for different flow rates in Figure~\ref{COMSOL_Pe}.
\begin{figure}[ht]
\centering
\includegraphics[width=1\columnwidth]{comsolpe.jpg}
\renewcommand{\captionfont}{\linespread{1.6}\normalsize}
\caption{COMSOL simulation for the profile of the oversaturation pulse at (a) $Pe$ = 458, (b) $Pe$ = 1,832, (c) $Pe$ = 2,747, and (d) $Pe$ = 4,579.
}
\label{COMSOL_Pe}
\end{figure}
The non-blue area is the mixing front, and the color scale bar indicates the corresponding concentration of oversaturation pulse in the system. At $Pe$ of 458, the oversaturation pulse passes through the entire chamber in 16 $s$. At the highest $Pe$ of 4,578, the duration of the pulse is approximately 2.7 $s$. Although the time for the precipitation is considerably shorter at larger $Pe$, the oversaturation levels near the bottom wall are similar through the entire process at all $Pe$, as exhibited by the consistent blue zone at the bottom in all snapshots. Therefore, diffusion of asphaltene and n-heptane towards the substrate at different $Pe$ should be comparable because the concentration gradient is identical, resulting in a similar $SC$ of asphaltene on the bottom wall. At any given moment, the level of the oversaturation on the top plate is substantially higher at lower $Pe$, which may lead to more precipitates on the top surface.

Figure \ref{flow rate results}(a) shows the optical images of asphaltene precipitation in the solvent exchange with the flow rate of solution B ranging from 15 $mL/h$ to 150 $mL/h$ (i.e., $Pe$ from 458 to 4,579).
\begin{figure}[ht]
\centering
\includegraphics[width=1\columnwidth]{flowrateresults.jpg}
\renewcommand{\captionfont}{\linespread{1.6}\normalsize}
\caption{(a) Optical images of asphaltene particle at the final state of different P\'{e}clet numbers. The length of the scale bar is 20 $\mu m$. The images are false-colored. (b) $SC$ of asphaltene particles at the final state as a function of P\'{e}clet number. (c) Size distribution of asphaltene particles for different $Pe$. The solid lines are the Gaussian fitting for the results. (d) The corresponding peak size of Gaussian fitting of (c) vs. P\'{e}clet number.}
\label{flow rate results}
\end{figure}
The black dots are asphaltene particles formed on the substrate placed on the bottom wall. It is worth mentioning that only the area with asphaltene particles is considered. The areas of asphaltene layers, as shown in Figure \ref{1000}(b), are omitted when analyzing surface coverage ($SC$) and the size distribution of asphaltene particles because these large deposits may be agglomerates formed in the bulk. Figure \ref{flow rate results}(b) shows $SC$ of the asphaltene particles divided by the total area, which is approximately independent of $Pe$ and is always $\sim$ 14\%.

Figure \ref{flow rate results}(c) shows the size distribution of asphaltene particles. The distribution is plotted based on area density instead of the number density \cite{maqbool2011modelling} to compare with the conventional study in a bulk system. Interestingly, the Gaussian distribution can fit the area density-based size distribution for each $Pe$. This Gaussian distribution is consistent with the presented results in a conventional mixing system \cite{maqbool2011modelling}. The peaks of the size distribution in Figure \ref{flow rate results}(c) shift to the left with the increase of $Pe$, indicating the size of asphaltene particles decreases with the increase of $Pe$ (Figure \ref{flow rate results}(d)).

Figure \ref{flow rate TIRF}(a) shows the TIRF images of asphaltene particles at different $Pe$.
\begin{figure}[ht]
\centering
\includegraphics[width=1\columnwidth]{flowratetirf.jpg}
\renewcommand{\captionfont}{\linespread{1.6}\normalsize}
\caption{(a) TIRF images of asphaltene particles at the final state of different $Pe$. The length of the scale bar is 5 $\mu m$. (b) Relative frequency of size distribution of asphaltene particles at different flow rates.
}
\label{flow rate TIRF}
\end{figure}
The white speckles are the asphaltene particles due to the natural fluorescence property of asphaltene under 488 $nm$ laser excitation in air. Number density-based relative frequency is introduced to analyze the size distribution quantitatively. The relative frequency of each size bin is calculated by the number of particles of the corresponding size divided by the total number of particles. For primary submicron particles (PSMPs), which are defined as the radius from 200 to 400 $nm$ \cite{meng2021primary}, the relative frequency denotes the degree of aggregation at the early stage. A high relative frequency of PSMPs ($R_p$) represents the low possibility of PSMPs aggregating into larger particles after the precipitation. From the quantitative examination, as shown in Figure \ref{flow rate TIRF}(b), it can be observed that $R_p$ decreases with the increase of $Pe$. \textcolor{black}{$R_p$ is calculated by:}

\begin{equation}
\color{black}
\label{Rp}
R_p = \frac{N_{psmp}}{N_{psmp}+N_{smp}}
\end{equation}
\textcolor{black}{where $N_{psmp}$ and $N_{smp}$ are the quantity of primary submicron particles and quantity of submicron particles, respectively.}

Interestingly, the size of asphaltene particles correlates with the flow rate because of the mass transfer process of asphaltene from the oversaturation pulse to the substrate. The size of asphaltene particles decreases with $Pe$ at micron-scale (Figure \ref{flow rate results}(c)) but increases at submicron scale (Figure \ref{flow rate TIRF}(b)). The particle aggregation and fragmentation process are discussed to examine the reasons for the opposite trend of size distribution at submicron and micron scales. Based on the Smoluchowshi aggregation model, the aggregation is:

\begin{equation}
\label{Sm_5}
\frac{dn_k}{dt}=\frac{1}{2} \sum_{i+j=k} K_{i,j} n_i n_j - n_k \sum_{i \ge 1} K_{i,k} n_i
\end{equation}
where $n_i$, $n_j$, and $n_k$ is the number density change of particle of size $i$, $j$, and $k$, respectively. $t$ is time, and $K_{i,j}$ is aggregation kernel, which is calculated by $K_{i,j} = \alpha_{i,j} \beta_{i,j}$, where $\alpha_{i,j}$ is the collision frequency and $\beta_{i,j}$ is the collision efficiency of particles. $\beta_{i,j}$ is:

\begin{equation}
\label{beta_5}
\beta_{i,j} \propto exp [- \frac{1}{k_B T (\delta_{asp} - \delta_{sol})^2}]
\end{equation}
where $k_B$ is Boltzmann constant, $\delta_{asp}$ and $\delta_{sol}$ are Hildebrand solubility parameters of asphaltene and the paraffinic solvent, respectively. $\alpha_{i,j}$ is driven by two factors in our system, including Brownian motion and shear force \cite{nassar2015development,Ali2008Dynamic,thomas1999flocculation,rahmani2003characterization,rahmani2004evolution}:

\begin{equation}
\label{alpha}
\alpha_{i,j} = \frac{2}{3} \frac{RT}{\mu} \frac{(d_i + d_j)^2}{d_i.d_j} + \frac{G}{6}(d_i + d_j)^3
\end{equation}
where $R$ is the ideal gas constant. $T$ is temperature. $\mu$ is viscosity. $d_i$, and $d_j$ are the diameters of particles with sizes $i$ and $j$, respectively, $G$ is the shear rate.

The oversaturation level near the bottom wall is similar for all the $Pe$ (Figure \ref{COMSOL_Pe}). Regardless, the velocity gradient between the maximum point of the flow and the minimum point adjacent to the substrate increases with $Pe$. The increased shear force leads to the increase of aggregation of PSMPs at an early stage (Equation (\ref{alpha})), ultimately resulting in lowering of $R_p$ (Figure \ref{flow rate TIRF}(b)).

However, shear force brings an increase in the aggregation and the fragmentation of aggregates. The mechanism of fragmentation induced by shear rate is due to different pressures gradient on the opposite sides of the aggregates \cite{parker1972floc}. The fragmentation rate ($B_i$) increases with the particle volume ($V_i$) and the shear rate ($B_i = k G^y V_i^{1/3}$), where $k$ is a proportionality fitting constant, $y$ is a constant inversely proportional to the interaction strength between particles \cite{rahmani2003characterization,kapur1972self,boadway1978dynamics,pandya1982floc}. Therefore, when the asphaltene particles are large enough (i.e., at the micron scale), the fragmentation yielded by shear force prevails, resulting in the decrease of particle size with the increase of shear rate (Figure \ref{flow rate results}(d)). \textcolor{black}{It is worth noting that there is no maximum critical size for the asphaltene particles in the solvent exchange process because the chemical composition varies with time.}

\subsection{Effect of the microchamber height}

A dimensionless number (Rayleigh number, $Ra$) is used to quantitatively analyze the impact of channel height on $SC$ (Table \ref{table 1}). The oversaturation levels near the bottom wall are always high, as exhibited by the red color in Figure \ref{COMSOL channel height}.  At $Ra$ of 219, the oversaturation pulse passes through the chamber in 2.1 $s$. At the highest $Ra$ of 39,873, the duration of the pulse is approximately 9.3 $s$. The increased duration of the oversaturation pulse provides a longer time for asphaltene precipitation and aggregation. Therefore, mass transfer of asphaltene from the oversaturation pulse to the substrate should increase with the increase of the $Ra$, resulting in a higher $SC$ and larger size of asphaltene particles.

\begin{figure}[ht]
\centering
\includegraphics[width=1\columnwidth]{comsolchannelheight.jpg}
\renewcommand{\captionfont}{\linespread{1.6}\normalsize}
\caption{COMSOL simulation for the profile of the oversaturation pulse at (a) $Ra$ = 219, (b) $Ra$ = 1,753, (c) $Ra$ = 11,814, and (d) $Ra$ = 39,873.
}
\label{COMSOL channel height}
\end{figure}

Figure \ref{channel height results}(a) shows the optical microscope images of asphaltene precipitates in channel heights from 90 $\mu m$ to 510 $\mu m$ under the same $Pe$.
\begin{figure}[ht]
\centering
\includegraphics[width=1\columnwidth]{channelheightresults.jpg}
\renewcommand{\captionfont}{\linespread{1.6}\normalsize}
\caption{(a) Optical images of asphaltene particles at the final state for different $Ra$. The length of the scale bar is 20 $\mu m$. The images are false-colored. (b) $SC$ of asphaltene at the final state as a function of Rayleigh number. (c) Size distribution of asphaltene particles for different channel heights. The scatters are the experimental data and the solid lines are the Gaussian fitting for the results. (d) The corresponding peak size of Gaussian fitting of (c) vs. channel height.
}
\label{channel height results}
\end{figure}
It is found that more asphaltene particles are formed with the increase of the channel height. Meanwhile, the size of asphaltene particles increases with the increase of the channel height. $SC$ increases with $Ra$ (Figure \ref{channel height results}(b)). The relationship is almost linear. However, the linear relationship is not held when the channel height is 1,000 $\mu m$ as shown in Figure \ref{1000}(a). At 1,000 $\mu m$, many asphaltene deposits do not exist as particles but form a layer of sediments, as shown in Figure \ref{1000}(b). \textcolor{black}{Therefore, $SC$ increases as the channel height increases and eventually reaches a maximum value.} The formation of a larger $SC$ and a layer of sediments of asphaltene are in line with the numerical findings.
Figure \ref{channel height results}(c) shows the size distribution of asphaltene particles as a function of $Ra$. The size distribution for each $Ra$ can be fitted by Gaussian distribution. The Gaussian curve peaks increased from $\sim$ 0.2 to $\sim$ 0.9 with $Ra$ increasing from 219 to 39,873. It indicates that the mean particle radius increases from 1.6 $\mu m$ to 7.9 $\mu m$ as shown in Figure \ref{channel height results}(d). Particle size increases with $Ra$ because better solution mixing leads to an increase in particle collision efficiency $\beta$ in Equation (\ref{beta_5}), resulting in larger particles. These observations are also consistent with our numerical model predictions.

Our simulations for the vertically placed devices also demonstrate that the duration of the oversaturation pulse increases with the increase of the channel height, as shown in Figure \ref{vertical placed}(d), which is consistent with the horizontally placed devices. Therefore, the $SC$ increases with the channel height and the size distribution shifts to the right with the increase of channel height (Figure \ref{vertical placed}(a)-(c)).
\begin{figure}[ht]
\centering
\includegraphics[width=1\columnwidth]{verticalplaced.jpg}
\renewcommand{\captionfont}{\linespread{1.6}\normalsize}
\caption{(a) Optical images of asphaltene particles at the final state of different channel heights. The length of the scale bar is 20 $\mu m$. The images are false-colored. (b) Surface coverage of asphaltene at the final state as a function of channel heights. (c) Size distribution of asphaltene particles for different temperatures. The solid lines are the Gaussian fitting for the results. (d) COMSOL simulation for the profile of the oversaturation pulse at different channel heights.
}
\label{vertical placed}
\end{figure}

TIRF images of the final state of asphaltene particles are captured to show the details of asphaltene particles at the submicron scale, and is shown in Figure \ref{channel height TIRF}(a).
\begin{figure}[ht]
\centering
\includegraphics[width=1\columnwidth]{channelheighttirff.jpg}
\renewcommand{\captionfont}{\linespread{1.6}\normalsize}
\caption{(a) TIRF images of asphaltene particles at the final state for different channel heights. The length of the scale bar is 5 $\mu m$. (b) Relative frequency of the size distribution of asphaltene particles of different channel height.}
\label{channel height TIRF}
\end{figure}
It can be seen from Figure \ref{channel height TIRF}(b) that $R_p$ decreases from $\sim$ 65\% to $\sim$ 52\% with the increase of $Ra$ from 219 to 39,873, reflecting the aggregation of particles is more intensified in the channel with a more significant height. Correspondingly, the proportion of large particles, especially those larger than 0.8 $\mu m$, increases with the increase of the channel height. This observation at the submicron scale is consistent with that at the micron scale.

\subsection{Effect of the microchamber orientation}

In the device with the same channel height, the oversaturation pulse takes the same time to pass through the channel in both horizontal and vertical devices. However, the mixing dynamics are different. When the channel height is 510 $\mu m$ ($Ra$ is 39,873 for the horizontally placed device), simulation results showed the formation of convective rolls (Figure \ref{COMSOL channel height}(d)) in the horizontally placed device, leading to better mixing between solutions A and B. The final maximum oversaturation level for the horizontally placed device is approximately 0.02, while the one for the vertically placed device is approximately 0.01. In addition, the oversaturation area is not in the middle but shifts downwards and thus closer to the bottom wall because the asphaltene is heavier compared with n-heptane and toluene, an asphaltene-rich domain forms at the tail of the profile of the oversaturation pulse (Figure \ref{COMSOL channel height}(c)). However, the asphaltene-rich domain does not appear in the vertically placed cases. The loss of convective rolls and asphaltene-rich domain in the vertically placed devices results in reduced mass transfer compared to horizontally placed devices. Therefore, diffusion of asphaltene and n-heptane towards the substrate of the vertically placed device should be smaller than the horizontally placed device, resulting in the decrease of $SC$ and left-shift of the particle size distribution.

Figure \ref{vertical}(a) shows the comparison of optical images of asphaltene precipitates between horizontally and vertically placed devices. The horizontally placed device has a higher $SC$ of asphaltene particles than the vertically placed device, especially for 510 $\mu m$ (Figure \ref{vertical}(b)). $SC$ increases from $\sim$ 12\% to $\sim$ 18\%, revealing more asphaltene deposits on the substrate, which is in line with the numerical results.

The numerical results of varying P\'{e}clet number displays stack-like extreme convective rolls and very large asphaltene-rich region (Figure \ref{COMSOL_1000}). Video S1 (see supplementary information) shows a backflow after the mixing front reaches the outlet. Therefore, the $SC$ may increase sharply when the channel height is 1,000 $\mu m$. The formation of the layer of sediments in the 1,000 $\mu m$ channel height group is consistent with our numerical results in Figure \ref{1000}(b). Due to the intense mixing of the model oil and solvents, the asphaltene precipitation at 1,000 $\mu m$ may be closer to that in the bulk phase mixing system in the conventional study \cite{xu2017asphaltene}.

Orientation direction can also affect the size distribution of the asphaltene particles deposited on the substrate. Figure \ref{vertical}(d)-(f) reveals the rightwards shift of particle size in the horizontally placed device, meaning the asphaltene particles are relatively large in horizontally placed devices compared with the vertically placed ones. However, the shift of size distribution is not observed in the 90 $\mu m$ microchamber (Figure \ref{vertical}(c)). This is due to $Ra$ is smaller than the critical value (1,708) when the channel height is 90 $\mu m$ \cite{Zhang9253}. The convective rolls and asphaltene-rich domain are not observed in the horizontally placed device.

In the solvent exchange process, particles may form on the substrate and in the bulk of the liquid simultaneously. The particles formed in the bulk may settle down onto the substrate under gravity in the horizontally placed device. This is mainly due to the competition between gravity and Brownian motion. Brownian motion of the particles ($\overline{X}_{Brownian}$) is \cite{allen1990particle}:

\begin{equation}
\color{black}
\label{Brownian}
\overline{X}_{Brownian}^2 = \frac{4RTK_mt}{3\pi^2 \mu Nd}
\end{equation}
where $R$ is the ideal gas constant, $T$ is temperature, $K_m$ is the correction for discontinuity of fluid, which is 1 for liquid. $t$ is time, which is calculated by dividing the volume of the microchamber by the flow rate, $\mu$ is the viscosity of the solvent, $N$ is Avogadro constant, \textcolor{black}{$d$ is the diameter of particles}. The Stokes settling motion of a particle is \cite{allen1990particle}:

\begin{equation}
\color{black}
\label{stokes}
\overline{X}_{Settling} = \frac{(\rho_{asp}-\rho_{sol}) g d^2 t}{18 \mu}
\end{equation}
where $\rho_{asp}$ is the density of asphaltene and $\rho_{sol}$ is the density of the solvent. For each channel height, only the particles with a diameter larger than 8 $\mu m$ (logarithmic radius is 0.6) can settle under gravity. However, the rightwards shift is observed of particles smaller than 8 $\mu m$ as shown in Figure \ref{vertical}(d). In addition, particles larger than 8 $\mu m$ in Figure \ref{vertical}(c) of 90 $\mu m$ device do not show a rightwards shift. Therefore, gravity-induced settlement is not the reason for the rightwards shift in horizontally placed devices. The increase of particle size is also due to the enhancement of solution mixing in the horizontally placed device.

\subsection{Effect of the temperature}

The density difference between solutions A and B does not change significantly with the change in temperature (Table \ref{parameters}). The duration for the oversaturation pulse to completely pass the entire channel is approximately 4 $s$ for all the examined temperatures. Figure \ref{COMSOL_temp} shows the profile of the oversaturation pulse near the bottom wall does not change much with the increase in temperature, as indicated by the consistent blue zone.
\begin{figure}[ht]
\centering
\includegraphics[width=\columnwidth]{comsoltemp.jpg}
\renewcommand{\captionfont}{\linespread{1.6}\normalsize}
\caption{COMSOL simulation results of the oversaturation profile at 20 $^\circ C$, 35 $^\circ C$, 50 $^\circ C$, 58 $^\circ C$, and 65 $^\circ C$.}
\label{COMSOL_temp}
\end{figure}
In addition, from the experiments performed in the 1,000 $\mu m$ microchamber, it was evident that there \textcolor{black}{was} sufficient mixing in all of the temperatures due to the presence of convective rolls, as shown in Figure \ref{COMSOL_1000}. Therefore, mixing at all the temperatures we studied should be adequate.

Figure \ref{temp results}(a) shows the optical images of asphaltene particles at different temperatures.
\begin{figure}[ht]
\centering
\includegraphics[width=1\columnwidth]{tempresults.jpg}
\renewcommand{\captionfont}{\linespread{1.6}\normalsize}
\caption{(a) Optical images of asphaltene particles at the final state of different temperatures. The length of the scale bar is 20 $\mu m$. The images are false-colored. (b) Surface coverage of asphaltene at the final state as a function of temperature. (c) Size distribution of asphaltene particles for different temperatures. The solid lines are the Gaussian fitting for the results. (d) The corresponding peak size of Gaussian fitting of (c) vs. temperature.
}
\label{temp results}
\end{figure}
$SC$ from 20 $^\circ C$ to 58 $^\circ C$ are similar but $SC$ of 65 $^\circ C$ is much smaller than the other groups. The size distribution shows a rightwards shift trend with the increase of temperature from 20 to 58 $^\circ C$. But the size distribution shifts to left from 58 to 65 $^\circ C$ (Figure \ref{temp results}(b)-(d)). The experiment results are mainly due to the thermodynamics influence. Asphaltene is a mixture of different fractions, and the increase in temperature resulted in some asphaltene fractions becoming soluble in asphaltene \cite{acevedo2010investigation}. \textcolor{black}{The reason may be the increase of steric repulsion between asphaltene particles caused by the increase in temperature \cite{wang2010interaction,wang2009colloidal}.} These asphaltene fractions do not precipitate, resulting in a decrease of $SC$ at 65 $^\circ C$. This observation is consistent with the previous study in a conventional bulk system \cite{xu2017asphaltene}.

Figure \ref{temp tirf}(a) shows the TIRF images of asphaltene particles. The quantitative size distribution at the submicron scale is shown in Figure \ref{temp tirf}(b). In summary, PSMPs are less likely to aggregate into fractal particles with increasing temperature.
\begin{figure}[ht]
\centering
\includegraphics[width=1\columnwidth]{temptirf.jpg}
\renewcommand{\captionfont}{\linespread{1.6}\normalsize}
\caption{(a) TIRF images of asphaltene particles at the final state of different temperatures. The length of the scale bar is 5 $\mu m$. (b) Relative frequency of size distribution of asphaltene particles at different temperatures.}
\label{temp tirf}
\end{figure}

Equations (\ref{beta_5}) and (\ref{alpha}) show both the collision frequency and efficiency increase with temperature. Therefore, the overall right-shift trend from 20 $^\circ C$  to 58 $^\circ C$  in micron scale is expected in Figure \ref{temp results}(c) and (d). The leftwards shift from 58 $^\circ C$ to 65 $^\circ C$ is caused by asphaltene dissolution in n-heptane at 65 $^\circ C$, as we discussed in the previous section. However, it is surprising that $R_p$ increases apparently from $\sim$ 48\% to $\sim$ 58\% with the increase of temperature at the submicron scale (Figure \ref{temp tirf}(b)). In this regard, it is to be noted that asphaltene is a mixture of several fractions. The responses of various fractions to temperature are different \cite{yang2016effect}. The increase in temperature causes some fractions of asphaltene become more soluble in n-heptane. The Hildebrand solubility parameter difference in Equation (\ref{beta_5}) is lower. The repulsive interaction between this 'soluble-like' fraction of asphaltene particles is high when they form PSMPs, causing a decrease in collision efficiency for further aggregation. In addition, a decrease in $SC$ also leads to less possibility of PSMPs aggregation \cite{meng2022size}. As a result, the PSMPs formed by these `soluble-like' asphaltene do not form aggregates but exist as PSMPs on the substrate to cause a higher $R_p$.

\section{Conclusions}
 Dilution-induced asphaltene precipitation was experimentally investigated using a solvent exchange method in a microchamber. The size distribution of asphaltene precipitates in high resolution images was analyzed and compared after 20 different mixing conditions with a paraffinic solvent, including flow rate, chamber height and orientation, and the solvent temperature.
 In the same microfluidic chamber, increasing the flow rate of paraffinic solvents accelerated the aggregation rate but caused the particle growth to stop at smaller levels. However, the flow rate had no obvious effect on the surface coverage of asphaltene precipitates. The surface coverage and size of asphaltene precipitates increased with the chamber height, regardless of the orientation of the chamber. But both the surface coverage and size of asphaltene particles of the horizontally placed device were larger than the vertically placed device when the channel height was higher than 180 $\mu m$. The difference between a horizontally and a vertically chamber was attributed the formation of convective rolls caused by gravity, which vanished in a narrow chamber (90 $\mu m$ in height). Moreover, our results showed that  higher temperatures resulted in lower $SC$ and larger particle sizes from 20 to 65 $^\circ$C, possibly due to more stable asphaltene in the mixture liquid at higher temperature.  For all mixing conditions, the oversaturation pulse resulted from the solvent exchange process were simulated using a finite element method based multiphysics solver.  Our model results corroborated well with the experimental results. The combination of the experimental and simulation results demonstrated the significance of mixing dynamics on the morphology of the asphaltene precipitates.

The important implication from this study is that mixing conditions, such as flow rate, temperature, orientation, and dimension of microchamber, may be potentially leveraged as a cost-saving and effective approach to controlled asphaltene precipitation without using additional paraffinic solvents. \textcolor{black}{Our work covers a wide range of mixing conditions to be relevant to many situations.} Furthermore, this implication is not only applicable to asphaltene precipitation, but to other dilution-induced phase separation processes, such as nanoparticle aggregation or polymer precipitation.

\section*{Declaration of Competing Interests}
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

\section*{Acknowledgement}
The authors acknowledge the funding support from the Institute for Oil Sands Innovation (IOSI) (project number IOSI 2018–03), from the Natural Science and Engineering Research Council of Canada (NSERC)-Collaborative Research and Development Grants, and from the Canada Research Chair Program and from Canada Foundation for Innovation, John R. Evans Leaders Fund. The authors are grateful for technical support from IOSI lab, particularly from Lisa Brandt and Brittany MacKinnon. We also thank Compute Canada (www.computecanada.ca) for the computational facility and technical support. We are also grateful to Gilmar F. Arends for his help on symmetry software, Dr. Shantanu Maheshwari for his help on COMSOL simulations, and our industry steward Dr. Sepideh Mortazavi Manesh for the fruitful discussion.

\section*{Nomenclature}

$\alpha_{i,j}$ = Collision frequency ($m^3/mol \cdot s$)

$\beta_{i,j}$ = Collision efficiency

$\delta$ = Hildebrand solubility parameter ($MPa^{1/2}$)

$C$ = Concentration ($mol/L$)

$d$ = Diameter of particle ($\mu m$)

$D$ = Diffusion coefficient ($m^2/s$)

$F$ = Interfacial tension ($N/m$)

$g$ = Gravitational constant ($m/s^2$)

$G$ = Shear force ($s^{-1}$)

$h$ = Channel height ($\mu m$)

$J$ = Mass flux ($kg / m^{2} \cdot s^{}$)

$k_B$ = Boltzmann constant ($J/K$)

$K_{i,j}$ = Aggregation kernel

$K_m$ = Correction for discontinuity of fluid

$\mu$ = Viscosity ($mPa \cdot s$)

$\nu$ = Kinematic viscosity ($m^2/s$)

$n$ = quantity of particle

$N$ = Avogadro constant ($mol^{-1}$)

\textcolor{black}{$N_{psmp}$ = Quantity of primary submicron particles}

\textcolor{black}{$N_{smp}$ = Quantity of submicron particles}

$\phi$ = Level-Set function

$P$ = Pressure ($Pa$)

$Pe$ = P\'{e}clet number

$Q$ = Flow rate ($m^3/s$)

$\rho$ = Density ($kg/m^3$)

$R$ = Ideal gas constant ($J / K^{} \cdot mol^{}$)

$Ra$ = Rayleigh number

$Re$ = Reynolds number

$R_p$ = Ratio of primary submicron particles (\%)

$t$ = Time ($s$)

$T$ = Temperature ($K$)

$U$ = Mass average velocity ($kg/s$)

$w$ = Width ($\mu m$)

$\overline{X}$ = Particle moving distance ($m$)

\subsection{Fractal dimension}

\section{Large asphaltene layer}
When the channel height of the microfluidic chamber is 1000 $\mu m$, we noticed the formation of large asphaltene layer, as shown in Figure \ref{1000}(b). The corresponding COMSOL simulation is shown in Figure \ref{COMSOL_1000}.

\begin{figure}[ht]
\centering
\includegraphics[width=1\columnwidth]{1000.jpg}
\captionsetup{font={normal}}
\renewcommand{\captionfont}{\normalsize}
\renewcommand{\captionfont}{\linespread{1.6}\normalsize}
\caption{(a) SC of asphaltene at the final state as a function of Rayleigh number. The red-colored point is of 1,000 $\mu m$ channel height. (b) Optical image of layer of sediments in the 1,000 $\mu m$ channel height. The length of the scale bar is 50 $\mu m$.}
\label{1000}
\end{figure}

\begin{figure}[ht]
\centering
\includegraphics[width=\columnwidth]{COMSOL_1000.jpg}
\captionsetup{font={normal}}
\renewcommand{\captionfont}{\normalsize}
\renewcommand{\captionfont}{\linespread{1.6}\normalsize}
\caption{COMSOL simulations for the profile of the pulse of oversaturation in horizontally placed 1000 $\mu m$ microchannel.}
\label{COMSOL_1000}
\end{figure}

\begin{figure}[ht]
\centering
\includegraphics[width=1\columnwidth]{vertical.jpg}
\renewcommand{\captionfont}{\linespread{1.6}\normalsize}
\caption{(a) Optical images of asphaltene at the final state in vertical and horizontally placed devices. The channel heights are 90 $\mu m$, 180 $\mu m$, 340 $\mu m$, and 510 $\mu m$ from left to right. The length of the scale bar is 20 $\mu m$. The images are false-colored. (b) Comparison of $SC$ of vertically and horizontally place devices. Size distribution of asphaltene particles in vertically and horizontally placed devices with channel heights of (c) 90 $\mu m$, (d) 180 $\mu m$, (e) 340 $\mu m$, and (f) 510 $\mu m$.}
\label{vertical}
\end{figure}

\section{COMSOL simulation parameters at different temperatures}
Density and viscosity of n-heptane and toluene at different temperatures were obtained from the literature, as summaried in Table \ref{parameters}.

\begin{table}[ht]
\centering
\renewcommand{\captionfont}{\linespread{1.6}\normalsize}
\caption{Density and viscosity of n-heptane and toluene at different temperatures}
\label{parameters}
\begin{tabular}{|l|ll|ll|}
\hline
 & \multicolumn{2}{l|}{Density ($g/cm^3$)} & \multicolumn{2}{l|}{Viscosity ($mPa \cdot s$)} \\ \hline
 & \multicolumn{1}{l|}{n-Heptane} & Toluene & \multicolumn{1}{l|}{n-Heptane} & Toluene \\ \hline
20 $^\circ$C  & \multicolumn{1}{l|}{0.684 \cite{dandekar1998measurement}} & 0.867 \cite{Engineering} & \multicolumn{1}{l|}{0.417 \cite{dandekar1998measurement}} & 0.590 \cite{santos2006standard} \\ \hline
35 $^\circ$C  & \multicolumn{1}{l|}{0.671 \cite{pena1978isothermal}}  & 0.853 \cite{Engineering} & \multicolumn{1}{l|}{0.348 \cite{sagdeev2013experimental}} & 0.494 \cite{santos2006standard} \\ \hline
50 $^\circ$C  & \multicolumn{1}{l|}{0.658 \cite{iwahashi1990dynamical}} & 0.839 \cite{Engineering} & \multicolumn{1}{l|}{0.315 \cite{iwahashi1990dynamical}} & 0.422 \cite{santos2006standard} \\ \hline
58 $^\circ$C  & \multicolumn{1}{l|}{0.649 \cite{sagdeev2013experimental}} & 0.832 \cite{Engineering} & \multicolumn{1}{l|}{0.275 \cite{sagdeev2013experimental}} & 0.390 \cite{santos2006standard} \\ \hline
65 $^\circ$C  & \multicolumn{1}{l|}{0.645 \cite{sagdeev2013experimental}} & 0.825 \cite{Engineering} & \multicolumn{1}{l|}{0.264 \cite{sagdeev2013experimental}} & 0.365 \cite{santos2006standard} \\ \hline
\end{tabular}
\end{table}

Mutual diffusion coefficients of toluene and n-heptane binary mixture at different temperatures were calculated using the same method reported in our previous study \cite{meng2022}. In summary, the diffusion coefficient was estimated by Darken model \cite{almasi2021molecular,zhu2016prediction}:

\begin{equation}
    D_{ij} = \left(x_jD_{i}^{*} + x_iD_{j}^{*} \right) \Gamma
\label{equationDarken}
\end{equation}

The thermodynamics correction factor ($\Gamma$) was estimated based on activity coefficient ($\gamma_i$) as shown in Equation (\ref{equationthermo}). The activity coefficient was calculated by UNIFAC thermodynamic model with the software package Symmetry \cite{package_s}.

\begin{equation}
    \Gamma = 1 + x_i \left( \frac{\partial \ln \gamma_i}{\partial x_i} \right)
\label{equationthermo}
\end{equation}

The self-diffusion coefficients ($D_{1}^{*}$ and $D_{2}^{*}$) in the Darken model (Equation \ref{equationDarken}) were approximated using the Wilke-Chang equation:

\begin{equation}
    D_{i}^{*} = \frac{7.4 \times 10^{-8} \left(\psi_jM_j \right)^{0.5}T}{\mu_{j} \times V_{i,BP}^{0.6}}
\label{Wilke-Chang}
\end{equation}

$M_j$, $T$, $\mu_{j}$ and $V_{i,BP}$ represent the molecular weight of the solvent, temperature, solvent viscosity, and molar volume of solute at normal boiling point conditions, respectively. The estimated diffusion coefficients at different temperatures are summarized in Figure \ref{diffusion coefficient}.

\begin{figure}[ht]
\centering
\includegraphics[width=\columnwidth]{diffusion coefficient.jpg}
\captionsetup{font={normal}}
\renewcommand{\captionfont}{\normalsize}
\renewcommand{\captionfont}{\linespread{1.6}\normalsize}
\caption{Diffusion coefficients of toluene in n-heptane at (a) 20 $^\circ C$, (b) 35 $^\circ C$, (c) 50 $^\circ C$, (d) 58 $^\circ C$, (e) 65 $^\circ C$. Diffusion coefficient of toluene in n-heptane vs. temperature. }
\label{diffusion coefficient}
\end{figure}

\section*{Nomenclature}
$\gamma_i$ = Activity coefficient of solute at T and $x_i$

$x_i$ = Molar composition of solute $i$

$x_j$ = Molar composition of solvent $j$

$D_{i}^{*}$ = Self-diffusion coefficient of solute $i$ ($cm^2 \cdot s^{-1}$)

$D_{j}^{*}$ = Self-diffusion coefficient of solvent $j$ ($cm^2 \cdot s^{-1}$)

$D_{ij}$ = Mutual diffusion coefficient of solute $i$ in solvent $j$ ($cm^2 \cdot s^{-1}$)

$\Gamma$ = Thermodynamic factor

$M_j$ = Molecular weight of solvent $j$ ($g/mol$)

$T$ = Temperature ($K$)

$\mu_j$ = Viscosity of solvent $j$ at T ($cP$)

$\psi_j$ = Association factor of solvent $j$

$V_{i,BP}$ = Molar volume of solute $i$ at normal boiling temperature ($cm^3 \cdot mol^{-1}$)

redpajama_set_name: RedPajamaArXiv


text:
Site Must Be Cleaned Up Before Work on 12-Story Building Starts: Officials
By Ewa Kern-Jedrychowska |&nbspJuly 20, 2016 5:58pm
@ewakj
A new mixed-use building is planned at 124-22 Queens Blvd.
DNAinfo.com/Ewa Kern-Jedrychowska
QUEENS — A site where a new 12-story mixed-use building will soon be constructed in Kew Gardens has to undergo cleanup first after elevated levels of contaminants were found at the location, which used to house a dry cleaning business, state officials said.
The new development, at 124-22 Queens Blvd., will replace the building currently located at the site, where Elena Cleaners was operating from 1986 to 2015. The building, which was purchased by New Jersey-based developer Luciano LLC for $6.5 million in 2015, also included office space and a Chase ATM, according to city records.
The building will soon be demolished, but before construction of the new development can begin, the developer is required to do remedial work because a state study found tetrachloroethylene, a substance commonly used for dry cleaning of fabrics, at potentially hazardous levels in the soil beneath the site, as first reported by the Queens Chronicle.
Specific levels of the chemical, which may possibly be carcinogenic and cause skin irritation, were not immediately known, but the state Department of Environmental Conservation said in a fact sheet about the site that a so called "interim remedial measure" is planned for the site, meaning a cleanup which "can be conducted at a site relatively quickly."
During the cleanup, the contaminated soil will be excavated and removed from the site, the DEC said.
The new development, across the street from Queens Borough Hall and Queens Criminal Court, will include retail stores on the ground floor, offices on the second and third floors, and a health facility on the fourth floor, according to the application filed with the Department of Buildings last August.
Mark Dong of Luciano LLC said that the building will contain a total of 32 condominium units on the remaining floors.
There will also be 10 parking spaces for cars and 14 for bicycles in the basement, according to the application.
Dong said that the cleanup will begin as soon as the old building is demolished, and he expects it to take about a month.
The company hopes to complete the project in two years, Dong said.
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redpajama_set_name: RedPajamaCommonCrawl


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Bucks vs Celtics 2019 NBA Playoffs Betting Lines & Pick for Game 4
Written by Henry Watkins on May 6, 2019
Over the course of the regular season in the NBA, it's not unusual to see every team go through a little bit of a rough patch. With an 82-game season to navigate, there are going to be times when the confidence is down, or the breaks just don't go the way you want them to. While this is an expected part of the game, it's something that cannot be carried over into the playoffs. Simply going on a streak where a team loses back to back games could very well be the difference between winning and losing a series.
Both the Milwaukee Bucks and the Boston Celtics came into the second round after breezing through the opening round in a sweep. It quickly became clear, though, that things were going to be a good deal tougher, with Boston going on the road and stealing Game 1. The Bucks bounced back and took the next two games, though, and can now put the Celtics on the brink of elimination with a win in Game 4. It is the Celtics who are 1.5 points favorite for this one, with the point total set at 220 ½.
When: Monday, May 6 at 7 PM EST
Where: TD Garden, Boston
TV: TNT
Radio: Sports Hub
Live Stream: NBA League Pass
2019 NBA Playoffs Betting Lines: Boston Celtics -2 (Total 220)
Warriors vs Rockets 2019 NBA Playoffs Odds & Game 4 Preview
Why bet on the Milwaukee Bucks?
The Milwaukee Bucks finished the regular season with the best record in the NBA, but they also knew that people would forget all about that if they did not make a deep run in the playoffs. They certainly seemed to be aware of that in the opening round, dispatching the Detroit Pistons in a 4-game sweep that was about as one-sided as it gets.
The easy path got a little rockier in Round 2, though, with the Bucks dropping the opening game of this series in a 112-90 loss to the Celtics. Good teams recover quickly, which is exactly what Milwaukee did, winning Game 2 at home and then taking Game 3 in Boston. The Bucks are now 6-1 ATS in the playoffs and 7-2 ATS overall as a road dog.
Total Score: 118.08
Field Goal Percentage: 47.57
Three-Point Percentage: 35.46
Free Throw Percentage: 76.89
Total Rebounds: 49.83
Why bet on the Boston Celtics?
The Celtics could not have asked for a better start to this series, winning comfortably in Game 1 and stealing home-court advantage in the process. If they thought things were going to be easy, they were given a serious wake-up call in Game 2, with the Bucks bouncing back and winning 123-102.
Milwaukee upped the heat a little further with a win in Game 3 on the road in Boston. The Celtics now find themselves in a bit of a must-win situation, as you can't really like their chances of digging out of a 1-3 hole with 2 games still be to play in Milwaukee. Boston started the playoffs by covering 5 straight games, but they have failed to cover in each of the last 2.
Bucks vs Celtics 2019 NBA Playoffs Betting Trends
Bucks are 5-11 ATS in their last 16 games against Boston
Bucks are 4-1 SU in their last 5 games against Boston
The total has gone OVER in 5 of Milwaukee's last 6 games
Celtics are 2-9 ATS in their last 11 games at home
Celtics are 9-3 SU in their last 12 games
The total has gone OVER in 11 of Boston's last 15 games against Milwaukee
Expert Pick & Final Score Prediction for Bucks vs Celtics
This has the makings of a long series, but that could quickly change if the Bucks make it 3 straight wins in a row, which is exactly what I think they will do, albeit in a close one.
Score: Milwaukee Bucks 109 – Boston Celtics 107


Take Wilson Ave or Lawrence Ave east off of Lake Shore Drive – the roads loop towards the beach. Our dog beach is located on the Northwest corner of Montrose Beach (the point closest to the city). Look for the big corrugated steel walls of the old Boat Launch, and you're there.The entrance to Mondog is at the old boat launch structure.
The Montrose Dog Beach is Chicago's first legal off-leash beach.
Mondog started out in the summer of 2000 as a group of people with nothing more in common than the love of Montrose Beach and enjoying a good walk with our four-legged friends. We were brought together by our founder, Susan Kimmelman, with the intention of making legal what had been a long standing practice of early morning and evening walks on the beach.After 2 years of patience, persistence and compromise, and the unexpected passing of our beloved Susan, we were granted a corner of the beach for a pilot area, and we've been there ever since.
So why do we need Mondog? After all, isn't it the Park Districts' responsibility to take care of the Dog Parks? Well, yes and no. The Chicago Park District charter for Dog Friendly Areas (DFA) requires that every Dog Park has a community organization to sponsor it. Once the Dog Beach became an official DFA it fell to Mondog to oversee the area, and to represent the dog beach community. The Park provides us with some services, but it is up to us to keep our area clean and safe. Our members help clean the beach daily, inform newcomers of the rules, and exert a positive influence over the dog beach. We try to solve problems within the community, and alert the authorities when necessary. We keep in touch with the Park District, and with other Community organizations who have an interest in our great park system. We work to provide information to the members and make improvements to the beach.
You don't have to be a member of Mondog to visit the dog beach, but if you are a regular beach user you should consider becoming a member of Mondog. It's the best way to show your on-going support for the Dog Beach. Our strength is in our numbers, and we need your support to allow us to keep supporting Chicago's first off-leash dog beach.


You can help – become a member!
Climate change is real and it's up to each of us to do what we can to reduce its impact. We are looking for the next generation of parents and citizens to join this movement to help bring bold, environmentally-friendly energy solutions to reality.
Joining is easy – and just a one-off fee of $10.
Members can also participate in BCEC's management by voting at our Annual General Meeting and by joining one of our working groups. Members may also choose to invest in the cooperative.


text:
Save The Kalakala!
More Practical Solution(s)
3/2 - Return of the Kalakala, Spew
3/2 - A New Vision for the Kalakala?, Exit133
10/28/2008 - Preserve MV Kalakala & Black Ball Line, GoPetition.com
KALAKALA-Mania
Kalakala.org
by jenyum on 3/10/2009 @ 8:31am Hee. Nice one.
by fredo on 3/10/2009 @ 9:30am Other Kalakala reuses: Office space for Tacoma's 2 rapidly expanding businesses: Foreclosure and unemployment benefits processing.
by Dave_L on 3/10/2009 @ 12:20pm Brilliant! How much for the original? Or a signed photocopy? (Tacomic, that is, not the real Kalakala)
BTW, it's odd that other Kalakala's come up when searching, like Kalakala, Sudan, or some guy named Kalakala.
Once again, the Black Ball Ferry Line song, with the Andrews Sisters gleefully singing of the Kalakala.
www.archive.org/details/Bing-Crosby--And...
by NineInchNachos on 3/10/2009 @ 1:02pm Thanks Dave, ALL TACOMICS are available for purchase the day of publishing on FEED TACOMA at a value cost of $66.66 !
As a courtesy of your request and future TACOMIC CUSTOMERS I have created an item in the shops page:
tinyurl.com/buy-tacomic
maybe I can talk kevin into adding a 'buy original' link to the tacomic page.
by marumaruyopparai on 3/10/2009 @ 1:59pm How about putting the Kalakala back into service as a studio for RR Anderson, Muffy and Lord Xenu for the Learn 2 Draw teevee show?
Or, a new headquarters for CLAW, so you don't have to slum it in coffee shops anymore like crazy fez wearing homeless people.
by NineInchNachos on 3/10/2009 @ 5:45pm Yeah, this cartoon was dealing mostly with realistic or practical uses for the skeleton of the Kalakala. What you propose would be realistic in that world between awake and sleep known as the twilight zone... a child's fantasy of hot air and ladies underwear.
The Kalakala will live on alright, but only in dreams.
by Mofo from the Hood on 3/11/2009 @ 12:29am The Kalakala restoration plan is totally bogus. The real Kalakala was submerged off Vashon Island on December 8, 1941 after "Wong Way Kawasaki" a lost kamakazi pilot, flew past Pearl Harbor and nosedived his Zero onto the unescorted ferry.
The Kalakala clone we've seen is a tool of The Conspiracy to scam naive and sentimental Tacoman's into funneling their hard-earned money into "Educational" projects "For the Kid's."
Once the clone is "restored" then displayed to the public, the ferry will undergo an accelerated aging process, developed by Conspiracy atheist scientists. Next, The Ministry of Planned Giving developed by Conspiracy atheist MBA's will promote a cross-media marketing campaign to scam naive and sentimental Tacoman's into funneling their hard-earned money into "Educational" projects "For the Kid's."
by izenmania on 3/11/2009 @ 9:42am (RxR, your shops posting might benefit from a list of which Tacomics are still available. Possibly even with links!)
by jenyum on 3/11/2009 @ 9:43am Well, it looks like we may need the Kalakala after all. You know, it might go well with the architecture of Hunt Middle School. I could see it parked next to their cafeteria dome.
by jenyum on 3/11/2009 @ 11:16am
by NineInchNachos on 3/11/2009 @ 12:09pm that's a wicked photoshopped kalakala Tacoma mama
by Mofo from the Hood on 3/11/2009 @ 12:11pm VISUALIZE TACOMAN'S
by NineInchNachos on 3/11/2009 @ 12:41pm hey Joe, I'm working with Kevin on your 'sold' tacomic request. Hopefully we can add some admin functionality to my feed/shop account that lets me mark (un)availabe cartoons.
pioneering cartoon entrepreneurial technology here folks!
by NineInchNachos on 3/11/2009 @ 12:42pm in the meantime i'll put together a google doc spreadsheet or something..
by Dave_L on 3/11/2009 @ 6:50pm Hope I still got dibs ;-)
by Dave_L on 3/24/2009 @ 4:09pm I'm like a kid with a new toy as I purchased Tacomic #105 Save the Kalakala, framed and complete with custom inscription and decoy packaging. The exchange was made at the new Blackwater for the exact sum of a mere $66.66 USD. I wish Blackwater was more convenient for me. The new location looked fine, and I noticed a familiar face or two that I hadn't seen in a long time. And fortunately, Tacoma Urbanist wasn't there to document the exchange. Anyway, Thanks, RxR! Several more Tacomics still available, and unlike BA posters, these are one-of!
tinyurl.com/tacomic-sale
by NineInchNachos on 3/24/2009 @ 5:05pm
may it serve you well through the years Dave!
by Erik on 3/24/2009 @ 5:17pm Yeah. That's a good one. Nice one Dave L.
And fortunately, Tacoma Urbanist wasn't there to document the exchange.
Must have missed you.
by morgan on 3/28/2009 @ 11:21pm Did anyone catch the follow up to this in the Tacoma Weekly? I just caught it here (Kevin: they have RSS): www.tacomaweekly.com/article/2953/
Pretty interesting article! That upside down spire would be home to an indoor ski facility.
Here are some snippets:
Steve Rodrigues thinks it would be a big draw and would drive people to visit Kalakala, the aging ferryboat he purchased several years ago. Rodrigues wants to spend between $80 million and $100 million on what is arguably the most unconventional idea yet proposed for Tacoma?s downtown waterfront.
He envisions it as a part of an ambitious attraction for Thea Foss Waterway. Rodrigues wants to build an 11-story structure that would house ski runs, waterslides, skydiving, restaurants, hotel rooms and a health club.
Adjacent to it would be smaller buildings with retail shops.
Kalakala would be in the center of it all, restored to an extent that people could take tours of it. The ship would either sit in a trench on the land, or inside a special structure that would keep it out of the nearby water. Part of it would be a museum, while other areas could be rented for private parties.
Next to it would be a tank for dolphins and floating docks for future passenger ferries.
Rodrigues presented his proposal to Mayor Bill Baarsma, who steered him to the board of Foss Waterway Development Authority (FWDA). He made a presentation to the board on March 18.
Rodrigues is interested in site 4, located between the Esplanade and Thea?s Landing condominium buildings. Robert Thurston, a businessman who operates a boutique hotel at Pike Place Market in Seattle, had secured this parcel for a hotel/condominium building. His efforts have met numerous delays as the market for condos has gone downhill and he has found financing difficult to come by.
According to Rodrigues, Thurston is ready to abandon his plans. He told the board he has negotiated a deal with Thurston to purchase the land from him. ?He is willing to sell the property to us,? Rodrigues said.
That is absolutely crazy! And I love it! Tacoma needs more ideas like this around here - and the capacity to pull it off. See you on the slopes!
by ixia on 3/29/2009 @ 8:29am Nice to know soon we won't have to travel to Dubai to do some indoor downhill.
Perhaps the empty Esplanade could be offered up? Just lift the Kalakala up on top and voila- instant pre-use.
by L.S.Erhardt on 3/29/2009 @ 8:55pm It's so damn crazy... that it might work.
by Erik on 3/29/2009 @ 10:19pm The plan makes RR's renditions pretty tame.
by Twisty on 3/30/2009 @ 9:25am I saw that Tacoma Weekly article, too. I looked and looked, but I couldn't find Mike Parker's name on it anywhere.
by morgan on 3/30/2009 @ 9:32am What ever happened to Mike?
I would love to see an article on former city leaders on "Where Are They Now?" - seems like once they're out of office they fall off the face of the eart- or at least it seems like they aren't in Tacoma anymore.
by NineInchNachos on 3/30/2009 @ 9:33am before we go making accusations of whose idea is tame, please consider the context of my cartoon suggestions as PRACTICAL SOLUTIONS and thus have some chance of being implemented. An indoor ski slope surrounded by some of the best ski mountains ever is quite IMPRACTICAL... an idea of hot air and fantasy.
by Twisty on 3/30/2009 @ 9:43am "What ever happened to Mike?"
No idea, but my guess would be that he's out there selling stock in a cold fusion start-up or something similar.
by Twisty on 3/30/2009 @ 9:44am RR is spot-on. Indoor ski slopes work well in places like Dubai. The NW? Not so much.
by Mofo from the Hood on 3/30/2009 @ 12:32pm Regarding this fantasy building project newspaper story:
Is this the kind of customer bankers are looking for nowadays?
If I go out to Roy Y Auto Wrecking and buy a rusting heap of Pontiac and then say that I want to make it the center piece of a tennis club and tanning spa surrounding it, then I'm like newsworthy and a communty hero and worthy of receiving millions of dollars?
People used to think that National Enquirer newspaper wrote about wacky stuff...
by NineInchNachos on 3/31/2009 @ 10:24pm RIDDLE ME THIS:
what looks like an upsidedown pyramid mashed up with a paul bunion sized urinal?
you can also skydive down it...
MADE IN GERMANY. HOME OF THE HUMAN-SIZED OVEN!
by NineInchNachos on 3/31/2009 @ 10:31pm REBUTTAL STATEMENT:
"If he cannot work a deal in Tacoma, he said he has an alternate site on Puget Sound for Kalakala, as well as a different, undisclosed site for the ski attraction. �If you do not want our snow, if you do not want our hotel, we can take it somewhere else." ~ Steve Rodrigues, 2009
THE REALIST and SKEPTIC RR ANDERSON sez: do we indeed need more snow-jobs from developers? I'm tired of being hurt by these wild eyed dreamers. Be like me, do the right thing. Do the super thing. GIVE UP. EMBRACE OBLIVION. If you stare into the void long enough the void stares back. This november elect a CITY HECKLER you can believe in. Vote RR for City Heckler. the cynical choice
by NineInchNachos on 3/31/2009 @ 10:44pm TOURISTS, THRILL SEEKERS and ne'er-do-wellS...
do we want to be the city that attracts the type of people who would want to jump down a giant urinal?
i'm tired of the brain-dead vegas style pacifiers; the frivolous novelty.
I'm done with that.
I want thrifty practical and useful.
I want the hanging gardens of Babylon.... a research laboratory aquarium... oceanography institute... a kick ass library of Alexandria...
instead they give me fucking indoor skiing.
by NineInchNachos on 3/31/2009 @ 10:50pm this idea is so superman III
by Erik on 3/31/2009 @ 10:52pm RR, your just jealous because this guy came up with something crazier for the Kalakala than your Kalakala starship version.
Nice find on the toilet though, looks like the developer may have a copyright infringement issue to deal with.
by NineInchNachos on 3/31/2009 @ 10:54pm if they build this thing I'm going to make a giant salt patty out of Styrofoam block
I swear to god.
any how. yeah. It's crazy. crazy like a fox.
by NineInchNachos on 3/25/2011 @ 11:23pm NOOOOOOOOOOOOOO!
www.thenewstribune.com/2011/03/25/159996...
man alot of these old comments of mine are embarrassing. Now I know how Hans Zeiger must feel.
by fredo on 3/26/2011 @ 5:01am Nachos, I'm really feeling bad about the Kalakala.
The Kalakala could be a local icon. It's as emblemic of the Art Deco movement as anything in the world including the Chrysler Building.
If it's eventually cut up for scrap I think it will be sadder than the day the Luzon was demolished.
by NineInchNachos on 3/26/2011 @ 8:51am Kalakala stands alone on earth. There will never be another one... ever.
by NineInchNachos on 3/26/2011 @ 8:57am a song for the Kalakala www.youtube.com/watch?v=4spkVX8z-vs
by fredo on 3/26/2011 @ 9:15am You can't resist her
She's in your bones
She is your marrow
And your ride home
You can't avoid her
She's in the air
In between molecules
Of oxygen and carbon dioxide
Only in dreams
We see what it means
Reach out our hands
Hold on to hers
But when we wake
It's all been erased
And so it seems
You walk up to her
Ask her to dance
She says "Hey baby
I just might take the chance"
You say "It's a good thing
That you float in the air
That way there's no way
I will crush your pretty toenails into a thousand pieces"
I was looking at a picture of weezer. One of the band members had a large red birth mark on his face like Gorbachav. But then I cleaned by screen with some windex and I made his birth mark go away.
by Jesse on 3/26/2011 @ 9:27am Kiss this ship goodbye if the current owner doesn't either sell it to someone who can restore it right away or actually start fixing it up himself.
Another case of good intentions going bad. I'm sure this guy loves the ship and loves the fact that he owns it but obviously doesn't have the ability, money, or know-how to do anything with it.
(See also; Old City Hall, Luzon, Winthrop, etc.)
by fredo on 3/26/2011 @ 9:28am Are there enough people in the country who would respond to an appeal to send a few dollars to help save the Kalakala? Wouldn't a picture of this listing old behemouth get people to click through a little money on their paypal accounts? Imagine the Kalakala all polished up and proud, perhaps serving as venue available for weddings, reunions etc. People all dressed up and a big band playing Boogie Woogie Bugle Boy. Something like that. How do you make an idea like that go viral?
by Jesse on 3/26/2011 @ 9:30am The minute it got fixed up it would be off to Seattle. Anyone wanna bet me on that one?
Since it is currently trash, it's ok that it sits in Tacoma. As soon as it's worth something Seattle will want it -- and probably get it.
My call is that the only way it stays in Tacoma (and gets restored) is if the Tacoma Waterfront Maritime Museum buys and restores it --- soon.
by NineInchNachos on 3/26/2011 @ 9:35am I've emailed Steve Rodriguez a few times. He has a fanatical devotion to this ship. I'd say the Kalakala was his white whale... or Silver Fail Whale.. if his chest were a cannon he'd blow his heart upon it etc. The question is can the W.M. Dickson demolition claws operate in a maritime environment? Can you park the crane claws on a barge or something?
by fredo on 3/26/2011 @ 9:36am good point jesse.
OK, we place the Kalakala in a marina type spot with water all around it, but it's actually sitting on land surrounded with a little moat. It's not actually seaworthy. Place it near the LeMay museum and allow LeMay ticket holders free admission to tour the boat. I think this would be a hit.
by Jesse on 3/26/2011 @ 9:43am Perhaps the owner can donate the boat to the maritime museum for a tax write-off under the condition that they restore it. Then, the museum would really have something grand to boast about for a new capital campaign for the restoration. Have Rodriguez chair the campaign (as the volunteer chair as opposed to the professional one) and give him recognition somehow when it's finished.
Otherwise, right now, it looks like it's destined for the scrap yard.
by fredo on 3/26/2011 @ 9:53am The Kalakala is the nautical equivalent of the spruce goose airplane which has an entire structure built around it down in Oregon, I forget where. We could pull the Kalakala, ala the movie Fitzcaraldo, out of the marina and up the hill to the parking lot of the Tacoma Dome and cover it up. Put in some windows so people driving on I-5 can get a tantalizing view.
People are fretting about losing the history museum which is just a representation of history. The Kalakala is'nt a representation of history...it IS history.
by NineInchNachos on 3/26/2011 @ 9:53am would make a good greasy spoon restaurant too. wasn't there one of those already on ruston way?
by fredo on 3/26/2011 @ 9:57am There was a restaurant that looked like a ship, I don't know if it was an actual ship or not. I think it was called the Top of the Ocean or something like that. It's a little before my time here in Tacoma. It was near the foot of McCarver Street. Tacoma historians...Jinx?...Crenshaw?
by fredo on 3/26/2011 @ 10:08am When people think of seattle there are some things that immediately come to mind like the space needle and the pike place market. There is nothing like those two places and they really can't be recreated anywhere else. You have to go to seattle to experience them
but when people think of Tacoma the things they mention as iconic are really not so much iconic as merely curiosities. Yes the frisko freeze is nice and we have stadium high school but we are really deficient in the category of iconic landmarks. this is where the Kalakala would fit in.
Any one else agree or have a comment?
by jenyum on 3/26/2011 @ 10:39am I do agree, but unless someone forks over the money or the owner actually donates the boat I'm not sure what we can do.
by NineInchNachos on 3/26/2011 @ 1:38pm clap your hands if you believe in ferries!
by cisserosmiley on 3/26/2011 @ 1:53pm park a couple lemay cars on it and everyone will give em millions of dollars
by jenyum on 3/26/2011 @ 2:28pm I think the owner may be hoping to employ your magical strategy, RR...
kalakala.org/
"We need 8 private investors to become members towards saving the Kalakala effectively starting March 25, 2011. The Kalakala is now to be privately owned and managed as a for profit entity!"
Invest and become a member of the Kalakala. We are to sell private shares of stock. Join us by contacting Steve Rodrigues.
Email: olympicforum2000@usa.net
by Dave_L on 3/27/2011 @ 6:18pm www.youtube.com/user/HistoryMediaHistory...
by Mofo from the Hood on 3/27/2011 @ 10:39pm There's really only one fitting end for the Kalakala if it is to remain in Tacoma. I've sent a handwritten letter and sketches by courier to 1801 Dock Street and by tomorrow morning we shall awaken to a new dawn of integrated artistry---a synthesis of the best of Tacomakind's cultural history and its contemporary ingenuity and craftsmanship.
I've looked at the facts of the Kalakala story and used that knowledge to form the basis of a theory to explain why Tacoma's waterfront has developed to its present state. The fundamental question that has puzzled many Tacoman's is this: Why does a seaport which has a history of shipbuilding also have a contemporary glassblowing hotshop? I believe that the juxaposition of these seemingly unrelated fabrication shops reveals a cause and effect relationship that goes beyond mere coincidence.
If my theory and predictions prove to be more than conceptual chewing gum, we shall soon witness the seaship Kalakala encased in a magnificent handblown glass bottle!
by cisserosmiley on 3/28/2011 @ 4:28am maybe that could be the first feature installment at the new seattle glass museum
by NineInchNachos on 3/28/2011 @ 7:44am HA!
by The Jinxmedic on 3/28/2011 @ 8:03am Here's a new one for the "city motto" thread:
"Tacoma- where history comes to die."
by L.S.Erhardt on 3/28/2011 @ 8:58am I'm going to cry
by cisserosmiley on 3/28/2011 @ 12:10pm we should break off a piece of the 11th street bridge dough and restore the kalakala to run back and forth underneath it in hourly shows...SEE THE KALAKALA, RIDE THE KALAKALA!
by NineInchNachos on 3/28/2011 @ 12:16pm action playset!
by The Jinxmedic on 3/28/2011 @ 12:47pm It really should be part of a LeMay waterfront exhibit on the lower Foss. That would be a natural.
by NineInchNachos on 3/28/2011 @ 12:52pm it could be a traveling LeMay exhibit. park a bunch of cars on it an she could make the rounds.
by NineInchNachos on 3/28/2011 @ 12:55pm this guy had the right idea:
"They say it�s going to cost millions to clean up if it sinks. (Public funds of course) Why not be proactive and spend the same millions to fix it and do something positive with it?"
www.exit133.com/6200/the-kalakala-shrugg...
by The Jinxmedic on 3/28/2011 @ 1:33pm Because they don't think that way here. The Luzon would have been made safe with $50,000 of bracing while awaiting the Glitz Group financing for the rennovation. It cost over three times that amount to tear it down.
by cisserosmiley on 3/28/2011 @ 1:55pm park it on a pile of sand next to lemay like the crazy fireboat on ruston way
by NineInchNachos on 4/7/2011 @ 10:55pm Thanks Dave! www.tacomaweekly.com/news/city/kalakalas...
by NineInchNachos on 5/3/2011 @ 11:06pm noooooooooooooooooooooooooooooooooooooooooo! www.thenewstribune.com/2011/05/03/165148...
by L.S.Erhardt on 5/3/2011 @ 11:40pm Perhaps the time has come to let it go, RR.
Might be best to let it sink in Bellingham Bay rather than in Commencement Bay.
by NineInchNachos on 12/5/2011 @ 9:18pm anyone have a dollar I can borrow?
www.nwcn.com/home/?fId=135063898&fPa...
by Jesse on 12/6/2011 @ 7:20am I'm glad this guy is basically being forced to sell it. However, I bet it will end up scrap metal. I hope not.
by NineInchNachos on 1/5/2012 @ 4:15pm ON NPR!
www.npr.org/2012/01/05/144741339/sinking...
by NineInchNachos on 1/5/2012 @ 6:21pm so apparently the upper most dome pilot house portion of the Kalakala is made entirely of copper (via comment reply from npr news reporter) don't let that get out to the Meth copper thieves !
by The Jinxmedic on 1/6/2012 @ 7:55am I think you just did that...
by NineInchNachos on 5/6/2012 @ 10:09am alert Dave!
www.thenewstribune.com//2012/05/05/21333...
by ChrisTopher on 5/6/2012 @ 11:18am The Kalakala yesterday.
by Non Sequitur on 5/6/2012 @ 11:39am Abandon hope, ye who moor here...
by ChrisTopher on 5/28/2012 @ 8:41pm The Kalakala tonight.
by ChrisTopher on 5/28/2012 @ 8:43pm The Kalakala on 5/5/12
by NineInchNachos on 5/28/2012 @ 8:58pm doesn't look that bad.
by ChrisTopher on 5/28/2012 @ 9:08pm I can't get a close up picture without the security guard's siren going off. From what I've seen, I'm not sure if I believe it's unmovable with their estimated costs. If we asked the whole planet for ideas on how to safely relocate it, I'm sure we could find a more inexpensive way. The reports imply that the ship would fall to pieces if it was moved. I wonder how much worse it is now compared to how it was when it got there.
by L.S.Erhardt on 5/28/2012 @ 10:32pm Kayak down the Hylebos to the Kalakala.
by KevinFreitas on 5/29/2012 @ 7:00am I've always wanted to go on a kayak-based Kalakala photo shoot!
by NineInchNachos on 7/26/2012 @ 8:05pm he'll sue you. and you and you and you...
by NineInchNachos on 3/4/2013 @ 8:39am guys, it's time to get real.
petitions.whitehouse.gov/petition/save-k...


text:
William Jenkins may refer to:

 William Jenkins (1825–1895), Welsh general manager of Consett Iron Company
 William Jenkins (coal merchant) (1878–1968), British politician, former MP for Brecon and Radnor
 William (Bill) Jenkins (1925–2002), youngest Royal Marine to win a DSO in the Second World War
 William Jenkins (Labour politician) (1871–1944), former MP for Neath
 William Jenkins (Canadian politician) (1921–1995), politician in the Legislative Assembly of Manitoba
 William Miller Jenkins (1856–1941), American politician
 William Jenkins (veterinarian), former president of Louisiana State University
 William Jenkins (Northern Ireland politician) (1904–?), Lord Mayor of Belfast
 William Jenkins (Australian politician) (1895–1963), member of the South Australian House of Assembly
 William Jenkins (New Zealand) (1813–1902), New Zealand sailor, whaler, accommodation-house keeper, farmer, market gardener, horse-trainer and jockey
 William Jenkins (cricketer) (1788–1844), English cricketer
 William O. Jenkins (1878–1963), American businessman who made great wealth in Mexico
 William Stanley Jenkins (1890–?), Canadian flying ace during World War I
 William Fitzgerald Jenkins, better known under his pen name Murray Leinster (1896–1975), American science fiction author
 William Franklin Jenkins (1876–1961), Justice of the Georgia Supreme Court
 William A. Jenkins (1917–2022), United States Coast Guard rear admiral
 William Jenkins (priest) (born 1963), bishop coadjutor-elect in the Reformed Episcopal Church

See also
 Bill Jenkins (disambiguation)
 Billy Jenkins (disambiguation)

redpajama_set_name: RedPajamaWikipedia


text:
<?php

use yii\db\Migration;

/**
 * Handles the creation of table `domain`.
 */
class m170227_100050_create_domain_table extends Migration
{
    /**
     * @inheritdoc
     */
    public function safeUp()
    {
        $tableOptions = null;
        if ($this->db->driverName === 'mysql') {
            // http://stackoverflow.com/questions/766809/whats-the-difference-between-utf8-general-ci-and-utf8-unicode-ci
            $tableOptions = 'CHARACTER SET utf8 COLLATE utf8_unicode_ci ENGINE=InnoDB';
        }

        $this->createTable('{{%domain}}', [
            'id'          => $this->primaryKey(),
            'language_id' => $this->integer()->notNull(),
            'name'        => $this->string(45)->notNull(),
            'counter'     => $this->text()
        ], $tableOptions);

        $this->addCommentOnColumn('{{%domain}}', 'name', 'Format like example.com');
        $this->addCommentOnColumn(
            '{{%domain}}',
            'counter',
            'Field for storage google analytics (or other) counter code'
        );

        $this->createIndex(
            'idx-domain-language_id',
            '{{%domain}}',
            'language_id'
        );

        $this->addForeignKey(
            'fk-domain-language_id',
            '{{%domain}}',
            'language_id',
            '{{%language}}',
            'id',
            'NO ACTION',
            'NO ACTION'
        );
    }

    /**
     * @inheritdoc
     */
    public function safeDown()
    {
        $this->dropTable('domain');
    }
}

redpajama_set_name: RedPajamaGithub


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text:
Portraits from the London Underground Spanning 40 Years
The Tube started shuttling Londoners through its vast network of tunnels more than 150 years ago. Photographer Bob Mazzer has spent 40 of those years capturing the London Underground commuters, shining a spotlight on the evolving subcultures that have popped up over time. A former job as a movie theater projectionist found him traveling on the Tube late at night, surrounded by a cast of characters. Mazzer's work was shown in a Greater London Council exhibition at the Royal Festival Hall in the 1980s, but he's been sharing his photos on Facebook recently. See more of Mazzer's funny, touching, and surreal portraits of strangers on the London metro, which we spotted on Kottke, in our gallery.
Photo credit: Bob Mazzer


text:
Matsuyama, Schauffele headline as PGA Tour golf returns to Asia
Issued on: 19/10/2021 - 04:04
Tokyo (AFP) –
The US PGA Tour returns to Asia for the first time since the coronavirus pandemic when Japan hosts the Zozo Championship this week, with home hero Hideki Matsuyama and Olympic gold medallist Xander Schauffele headlining a strong field.
Two-time major winner Collin Morikawa will also be in action at the $9.95 million event at Accordia Golf Narashino Country Club in Chiba, east of Tokyo, from Thursday.
Other big names in the 78-man field include Tommy Fleetwood and Rickie Fowler, with 5,000 spectators allowed to watch each day as long as they wear masks at all times.
Masters champion Matsuyama will be the focus of intense home interest, while for the American Schauffele -- whose family has ties to Japan -- it will be a return to the country where he won Olympic gold in August.
The 24-year-old Morikawa, the highest-ranked player in the field at number three in the world, will also be popular because he is half-Japanese.
He was tied 22nd at the Zozo Championship in 2019, the year he turned pro, but plenty has happened since then, including major victories at the British Open and PGA Championship.
"Playing there (Zozo) in 2019, I was able to start my professional career and since then, two years later, the world has obviously changed, so has my golf game and my experience," Morikawa told the tournament's official website.
"So I look forward to hopefully contending and trying to win in Japan for the first time."
The inaugural edition of Japan's first US PGA Tour event in 2019 was memorably won by Tiger Woods -- the victory saw him tie the all-time mark of 82 PGA Tour wins held by the legendary Sam Snead.
But last year's tournament was moved to California because of the coronavirus pandemic.
There had been speculation that the Zozo Championship could be relocated again this year, after the other two tournaments on the US PGA Tour's "Asian Swing" fell victim to the pandemic.
The CJ Cup -- won by Rory McIlroy on Sunday, one shot ahead of Morikawa -- was moved from South Korea to Las Vegas.
Shanghai's World Golf Championships-HSBC Champions, scheduled for October 28-31, has been cancelled for the second successive year.
Last year's Zozo Championship winner, at Sherwood Country Club, Thousand Oaks, was Patrick Cantlay, who finished one stroke ahead of Jon Rahm and Justin Thomas.