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Defect Formation Mechanisms in Selective Laser Melting: A Review
Bi Zhang ORCID: orcid.org/0000-0001-5738-32661,2,
Yongtao Li1 &
Qian Bai1
Chinese Journal of Mechanical Engineering volume 30, pages515–527(2017)Cite this article
This article has been updated
Defect formation is a common problem in selective laser melting (SLM). This paper provides a review of defect formation mechanisms in SLM. It summarizes the recent research outcomes on defect findings and classification, analyzes formation mechanisms of the common defects, such as porosities, incomplete fusion holes, and cracks. The paper discusses the effect of the process parameters on defect formation and the impact of defect formation on the mechanical properties of a fabricated part. Based on the discussion, the paper proposes strategies for defect suppression and control in SLM.
Additive manufacturing (AM) is an approach in which a part is manufactured layer by layer from the data of a 3D model. AM is a "bottom-up" approach as opposed to the traditional subtractive manufacturing that is often referred to as the "top-down" approach [1, 2]. The AM approach does not require the traditional tools, fixtures and complicated procedures. Therefore, it can offer an advantage of economically fabricating a customized part with complex geometries in a rapid design-to-manufacture cycle. With the development of high energy beams, it becomes possible to manufacture metal parts of high performance. Due to its unique advantages, the AM approach has been widely applied in many industries, such as aerospace, medical devices, military and automobile [3–5].
Selective Laser Melting (SLM) is one of the additive manufacturing processes. It is relatively mature and has been a research focus in manufacturing metallic parts [6]. A schematic layout of a typical SLM setup is presented in Fig. 1 [7]. During the SLM process, data is provided from a CAD model which is then sliced into thin layers. Each sliced layer is further developed with the appropriate scan paths. Through the scanner mirrors, a laser beam selectively scans and melts the powders that are previously paved on the substrate according to the developed scan paths. After a layer is finished, the building platform is lowered by an amount equal to the layer thickness, and a new layer of powders is paved. The process repeats until the completion of the whole part. To date, the SLM process is able to fabricate metallic parts from different material powders, such as titanium alloys [7, 8], nickel-based superalloys [9, 10], aluminum alloys [11, 12] and stainless steels [13, 14].
Schematic layout of a typical SLM setup [7]
Although the SLM process offers a great advantage in manufacturing complex parts at a high material utilization rate [15], it is affected by many factors, such as laser energy input and scan speed, scan strategy, powder material, powder size and morphology. The SLM process consists of complicated physics, such as absorption and transmission of laser energy [16], rapid melting and solidification of material, microstructure evolution [17, 18], flow in a molten pool [19], and materials evaporation [20]. The process is thus affected by the aforementioned factors to form defects of porosities, incomplete fusion holes, cracks, and impurities, etc. These defects are detrimental to a fabricated part in terms of its mechanical and physical properties, which in turn limits the application of SLM [21–24].
Since defect formation is a critical issue in an SLM process, research has been directed towards understanding and suppression of defect formation [7, 24–36]. This paper reviews the recent research outcomes on the types and formation mechanisms of the common SLM defects, such as porosities, incomplete fusion holes, and cracks. The paper also reveals how the SLM defects may affect the mechanical properties of a fabricated part. Other defects, such as metallic inclusions, segregations, residual stresses, metallurgical imperfections may also have a significant impact on the mechanical properties of a fabricated part, their respective formation mechanisms will be reviewed in a separate paper and published elsewhere. Finally, the paper provides a reference for defect suppression and control in the SLM processes.
Defect Types
Many parameters are involved in an SLM process, such as laser power, scan speed, hatch spacing, layer thickness, powder materials and chamber environment. Defects are inevitably introduced if any of these parameters are improperly chosen. The common defects are classified in three types: porosities, incomplete fusion holes, and cracks.
Porosities
A porosity is usually small in size, typically less than 100 μm with an approximately spherical shape, as shown in Fig. 2 by arrows. The formation mechanisms of porosities are described as follows [7, 23, 24, 28].
Optical image of spherical porosities (marked by arrows) in an SLM part [7]
Firstly, if the packing density of metal powders is low, e.g., 50 percent, the gas present between the powder particles may dissolve in the molten pool. Because of the high cooling rate during the solidification process, the dissolved gas cannot come out of the surface of the molten pool before solidification takes place. Porosities are thus formed and remain in the fabricated part. Porosities may also be formed when metal powders of a hollow structure are utilized in an SLM process. On the other hand, the molten pool temperature is generally high due to the intense laser power. At this temperature, gas solubility in the liquid metal is high, making its enrichment easier. Furthermore, in the process of preparing powder materials, gas is inevitably introduced into the powder materials, especially the gas atomized powder materials in the scope of protection by an inert gas, such as argon or helium.
Qiu et al [28] observe that the porosities contain ridges in the internal surfaces and are thus probably associated with the incomplete re-melting of some local surfaces from the previous layers. The ridges form small volumes to which the molten metal is difficult to flow and penetrate. On the other hand, Gong et al [29] attribute these porosities to gas bubbles generated when a high laser energy is applied to the molten pool. Gas bubbles can be induced due to vaporization of low melting point constituents within an alloy. They can be far beneath the surface at the bottom of the molten pool. The high solidification rate of the molten pool does not give gas bubbles sufficient time to rise and escape from the surface. Thus, gas bubbles are trapped in the molten pool, resulting in defect inclusions of regular spherical porosities in the forming part.
It is therefore understood that such spherical porosities are generally resulted from the entrapped gases in the molten pool due to the excessive energy input or unstable process conditions. The spherical porosities are randomly distributed in an SLM fabricated part, and difficult to eliminate completely.
Incomplete Fusion Holes
Incomplete fusion holes, also known as lack-of-fusion (LOF) defects, are mainly due to the lack of energy input during an SLM process. The formation of the LOF defects is because the metal powders are not fully melted to deposit a new layer on the previous layer with a sufficient overlap [24, 29]. An LOF defect may contain numerous un-melted metal powders, as shown in Fig. 3(b) [37]. There are two types of LOF defects: (1) poor bonding defects due to insufficient molten metal during a solidification process, as in Fig. 3(a), and (2) defects with un-melted metal powders in Fig. 3(b).
Optical images of LOF defects in SLM fabricated parts: (a) poor bonding defects; (b) LOF defects with un-melted metal powders [37]
In the SLM process, a laser selectively melts the metal powders point by point, line by line, and layer by layer to complete the whole part. If the laser energy input is low, the width of the molten pool is small, which results in an insufficient overlap between the scan tracks. The insufficient overlap is a cause of formation of the un-melted powders between the scan tracks. In the deposition process of a new layer, it becomes difficult to fully re-melt these powders. As a consequence, incomplete fusion holes are formed and remain in the SLM fabricated part. Furthermore, if the laser energy input is too low to cause an enough penetration depth of the molten pool, LOF defects may be generated due to a poor interlayer bonding [24, 29, 37]. Therefore, LOF defects are usually distributed between the scan tracks and the deposited layers.
Moreover, in a location where defects have been generated, the surface of the location becomes rough. The rough surface directly contributes to the poor flow of the molten metal to form interlayer defects. The interlayer defects may gradually extend and propagate upwards to form large multi-layer defects in a continuous deposition process [38].
For the easily oxidized alloy materials, such as aluminum AlSi10Mg, a layer of oxide film is usually produced at the surface of a part with residual oxygen in the SLM process. Then wettability decreases and molten metal flow is blocked, leading to a poor bonding between the layers to form the incomplete fusion defects [25, 39]. Fig. 4 shows an image of an incomplete fusion defect. From the EDX (Energy Dispersive X-ray Spectrometer) data presented in Table 1, location 2 of an incomplete fusion defect is rich in oxygen, suggesting that this irregular defect should be associated with the presence of an oxide layer which could prevent the progress of bonding [39].
SEM image of an incomplete fusion defect at different locations [39]
Table 1 Element content analysis of the defect (wt. %)
In an SLM process, metal powders experience rapid melting and rapid solidification under a high local laser energy input. The cooling rate of the molten pool reaches 108 K/s [22], which creates a great temperature gradient and correspondingly a large residual thermal stress in the fabricated part. The high temperature gradient combined with the great residual stress often causes crack initiation and propagation in a fabricated part [22, 40, 41]. Fig. 5(a) shows the crack morphology in an SLM fabricated titanium part. Cracks are more prone to initiating from the as-built surface that is adhered with the partially melted metal powders. Fig. 5(b) shows the microstructure on both sides of a crack. It can be observed that elongated needle-type crystal grains are continued on the both sides of the crack, indicating a typical transgranular mode of cracking [40].
SEM images of crack morphology and microstructure from the cross section of an SLM fabricated Ti6Al4V part: (a) crack morphology; (b) microstructure on both sides of the crack [40]
For stainless steels and nickel-based superalloys, because of their low thermal conductivity and high thermal expansion coefficient, they are more vulnerable to generating cracks with high susceptibility to cracking in an SLM process [9, 27, 42, 43]. To solve this problem, pre-heating the substrate and improving the ambient temperature are recommended to reduce the cracks in the SLM fabricated parts [26, 27].
Effect of Process Factors on Defect Formation
Many process factors are involved in an SLM process. Some of the factors are process parameters that can be predetermined, while the others cannot be predetermined since they are generated from the SLM process. As described in Fig. 6, the major process factors can be classified into four types: laser-related, scan-related, powder-related, and temperature-related. Based on the principle that laser selectively melts the powders, the major factors which are related to defect formation in an SLM process are laser energy input, powder material, and scan strategy. Therefore, the following Sections 3.1-3.3 are dedicated to discussing defect formation in terms of the three factors.
Process factors involved in an SLM process [23]
Effect of Laser Energy Input
Laser energy input directly determines the melt condition of metal powders, the flow of molten metal, which has a significant impact on the type and size of the defects in an SLM process. The energy input in the material can be related to the main process parameters, such as laser power, scan speed, hatch spacing, and layer thickness.
At a relatively low scan speed and a high laser power, the energy input is high, more powders are melted at an elevated temperature, porosity defects are created. These defects can be attributed to the entrapped gas originated from the raw material powders in the SLM process as mentioned above. In addition, low melting point constituents, e.g., Al, Mg elements in the alloy, may evaporate into gas to form gas bubbles. During the rapid solidification process in SLM, the gas bubbles do not have sufficient time to escape from the molten pool to the pool surface. They remain within the molten pool to form porosity defects of a spherical shape [29, 44]. On the other hand, the molten pool becomes large if energy input is high, which causes powder denudation around the molten pool. The denudation process results in insufficient molten metal to fill the gap between the adjacent tracks. Large porosities are thus formed [7].
Furthermore, a relatively low scan speed and a high energy input may result in a high residual thermal stress in a rapid melting and solidification process. The higher the energy input, the more severe the contraction of the molten metal in the solidification process. A high residual stress is induced during the solidification process [22, 40, 45]. As shown in Fig. 7(a), with a high energy input, micro-cracks are observed in an SLM CP-Ti part. Conversely, almost no defects are found when an appropriate energy input is utilized, as shown in Fig. 7(b).
Optical images showing the microstructures on the cross-sections of SLM-processed Ti parts fabricated at different energy inputs: (a) cross-section with micro-cracks due to a higher energy input (P = 90 W, v = 100 mm/s); (b) nearly defect-free cross-section due to an appropriate energy input (P = 90 W, v = 200 mm/s) [22]
At a relatively high scan speed and a low laser power, the energy input is too low to fully melt the powders, generating a discontinuous molten pool. This makes it difficult to fully melt the powders between the adjacent tracks to form an effective overlap, resulting in the formation of incomplete fusion defects. In addition, if a large powder thickness causes an insufficient penetration of the laser energy input, an effective overlap may not be developed between layers, causing the formation of interlayer incomplete fusion defects [24, 29, 45, 46].
Fig. 8 shows two different defect types in the SLM fabricated titanium alloys under two different energy input conditions (laser power and other parameters remain constant, but scan speed varies) [47]. Fig. 8(a) describes the regular spherical defects under the higher energy input conditions. Conversely, Fig. 8(b) shows irregular incomplete fusion holes under the lower energy input conditions.
Optical images of defect morphologies at different energy inputs in the SLM-processed Ti6Al4V parts: (a) spherical porosities (P = 120 W, v = 40 mm/s); (b) incomplete fusion holes (P = 120 W, v = 1500 mm/s) [47]
Generally, energy density E is widely used to characterize energy input, which is a measure of the average applied energy per unit volume of the deposited material in an SLM process. Eq. (1) provides a representation of energy density E (J/mm3):
$$E = \frac{P}{v \times h \times t},$$
where P is laser power (W); v is scan speed (mm/s); h is hatch spacing (mm); and t is layer thickness (mm). The parameters in the equation reflect the impact of overlap between tracks, layer thickness and energy input and can easily be determined. Therefore, as a representation of energy input, this equation is used widely in the SLM processes [7, 29, 48].
Fig. 9 shows a scatter plot for both the void and defect fractions (%) as well as crack density that is represented by crack length per unit cross-sectional area (mm/mm2) against energy density E (J/mm3) in the SLM fabrication of high temperature Ni-superalloy and porosity in SLM Titanium parts [27]. As seen from the figure, with an increase in the energy density, more material is melted, void fraction is quickly reduced, especially when the energy density exceeds 70 J/mm3. A similar result can be acquired from the calculation results by different research groups on energy density calculation for the SLM fabricated titanium parts, but the appropriate energy density is different due to different materials [7, 22, 28, 47–52]. Conversely, the crack density shows a slight increase with the increase in energy density due to the large thermal stress caused by the excessive energy input.
Scatter plot of crack density and void fraction in SLM Ni-superalloy parts, and defect fraction in titanium parts against energy density; lines represent data trend
Therefore, as an integrated parameter, energy density represents the combined effect of the major process parameters on defect formation in an SLM process. Energy density is handy to use in selecting the appropriate laser power, scan speed, hatch spacing, layer thickness to minimize the defects and improve the manufacturing efficiency in the SLM process.
Effect of Powder Materials
The morphology and size of metal powders have a significant influence on the powder bed smoothness and powder flowability, thus are strictly required in an SLM process. Metal powders are produced in different methods, such as water atomization, gas atomization, plasma rotating electrode and electrolytic method, which has a diverse effect on defect formation [53–55]. In addition, the gas contained in the powders increases the probability of defect formation.
Wang et al [33] examined the effect of different powder sizes of the 316L stainless steel on the part quality in the SLM process. They reported that the metal powders of a smaller size tended to reduce porosities in the fabricated parts compared to those of a larger size. The relative density reached 99.75% with the average powder size of 26.36 μm, which was compared to 97.50% with the average powder size of 50.81 μm. Li et al [41] explored the densification behavior of gas and water atomized 316L stainless steel powders. As shown in Fig. 10, the gas atomized powders possessed spherical shapes compared to irregular shapes of the water atomized powders. The results demonstrated that the parts fabricated with the gas atomized powders acquired a higher relative density, less porosity compared to those with the water atomized powders, which can be attributed to the differences in morphology, packing density, flowability and oxygen contents between the two powders.
SEM images showing characteristic morphologies of stainless steel powders produced by: (a) gas atomization; (b) water atomization [41]
Effect of Scan Strategy
Scan strategy directly affects the heat transfer, powders melting and solidification, and ultimately defect location and distribution. Generally, three different scan strategies have been utilized in the SLM processes, namely "unidirectional", "zigzag", and "cross-hatching", as shown in Fig. 11 [7]. For the unidirectional and zigzag scan strategies, at the beginning and end of a scan track, laser power is usually unstable and scan speed is gradually reduced, which tends to result in a relatively higher laser energy input and defect formation [20, 56]. In addition, the impurities in the powders may also be pushed to the ends of a track in the densification process to form higher defect density. Actually, incomplete fusion defects are more frequently generated between the scan tracks and layers [57, 58]. Cross-hatching scan strategy can make the entire laser energy input more balanced in the whole layers, which effectively prevents defect accumulation and propagation.
Three different scan strategies: "unidirectional" (left), "zigzag" (center), and "cross-hatching" (right) [7]
The "island scan strategy" has been developed for parts fabrication, as illustrated in Fig. 12 [39]. Firstly, the filled layer is divided into several islands with each island being built randomly and continuously. Then the successive layers are displaced in a certain distance, so as to avoid the accumulation of defects in the same location. Furthermore, the residual thermal stress in the SLM fabricated parts can be more balanced to reduce cracks development. However, due to the problem of potentially unstable laser energy input and the change in scan orders, defects are generally formed at the border of small islands, which needs further improvements for the "island scan strategy".
Schematic illustration of the island scan strategy, (a) each layer is divided into islands and raster scanned; (b) the successive layers are displaced in 1 mm [39]
Yang et al [59, 60] applied the interlayer staggering and the orthogonal scan strategy to reducing the defects formed in the overlapping zone between tracks. As shown in Fig. 13, after one layer is completed, the laser scans the overlapping zone between the adjacent tracks to sufficiently melt powders in the next layer deposition. The orthogonal scan strategy is adopted in the next layer, so that energy input can be more balanced for reducing defects, as previously also mentioned.
Interlayer staggering and orthogonal scan strategy [60]
Influence of Defects on Mechanical Properties
Defects in an SLM process cause stress concentration in the fabricated part, which may lead to the part failure. When stress exceeds the material limit, a crack may form and gradually propagate in the part. The following Sections 4.1-4.2 are dedicated to discussing the influence of defects on the mechanical properties in the SLM parts.
Tensile Properties
As mentioned earlier, the metallic powders suffer a rapid melting and solidification in the SLM process, due to a large cooling rate, which produces a part with a finer grain microstructure and better tensile properties than those made of the traditional wrought counterparts [17, 30, 61, 62]. The tensile strength (TS), ultimate tensile strength (UTS), and elongation of the SLM titanium alloy parts are shown in Table 2. Both TS and UTS of the SLM titanium alloys are higher than their wrought counterpart, generally above 1,000 MPa. Therefore, the SLM titanium alloys can meet the tensile strength requirements for engineering applications. However, the elongations of the SLM titanium alloys are rather low (less than 10%), which may be attributed to the defects in the SLM parts.
Table 2 Tensile Properties of SLM-Fabricated Ti6Al4V Alloys and Wrought Counterpart
Furthermore, the SLM process has a directional effect on the properties of the forming parts due to its basic deposition principle. The directional effect is a direct cause of the severe anisotropy in the mechanical properties of the fabricated part. For a part fabricated based on the orthogonal scan strategy shown in Fig. 13, defects may be formed and distributed in the horizontal direction, resulting in the obvious reduction of the load-bearing cross-section area in the fabricated part [66]. If the loading direction coincides with the building direction, the part is more susceptible to failure, leading to a low strength of the part [24, 37, 67]. In addition, because of the epitaxial growth in the SLM process, the elongated columnar grains in the fabricated part also aggravate anisotropy of the part [28, 34].
Fatigue Properties
For an SLM fabricated part, defects are more detrimental to its fatigue strength due to the points of stress concentration. A defect often serves as a source of crack initiation and propagation, which may greatly reduce the fatigue strength of the part. The stochastic distribution of the defects also aggravates the scattering of fatigue life, which may severely restrict the application of the SLM fabrication.
Fig. 14 shows the results on fatigue life obtained from the literature on the SLM Ti6Al4V parts and their wrought counterparts [68–73]. In Fig. 14, the filled dots represent the parts that were not post-processed ("as-built"), while the unfilled dots were subjected to machining. Due to the presence of both internal and surface defects, the fatigue strength of the "as-built" SLM samples was approximately 200 MPa, far below that of their wrought counterparts. After machining, the SLM samples showed a slightly improved fatigue life, but still lower than that of the wrought counterparts.
Fatigue life of the SLM Ti6Al4V parts and their wrought counterparts
The morphology, number, size and location of defects all have a significant influence on the fatigue life of the SLM fabricated parts. Generally, the spherical defects have less influence on the fatigue life of a part due to their regular shapes and small size. On the other hand, the defects of an irregular shape (e.g., an incomplete fusion hole) promote stress concentration of a part so as to seriously reduce fatigue strength of the part because of the irregular shapes and larger sizes of the defects [37, 47].
Gong et al [47] tested the SLM fabricated parts containing different numbers and types of defects, and found that the spherical defects had less influence on the fatigue life when the level of such defects was less than 1%, as shown in Fig. 15. However, the fatigue life was considerably decreased when these defects were amounted at the level of 5% porosity. Conversely, the irregular defects were found significantly detrimental to the fatigue life even when present in an amount as low as 1% porosity. When a part containing such defects in a higher amount of 5% in porosity, the part tended to have a low fatigue life with a narrow trend of dispersion, which suggests that the defects be so seriously detrimental to the fatigue life of the part even the statistical nature of fatigue life is defeated.
Fatigue performance of the parts containing defects from the SLM process [47]
Kasperovich et al [65] tested the parts that were differently post-processed, namely, "as-built", "surface-machined", "heat-treated", "hot isostatically pressed" (HIP, which is used in the traditional powder metallurgy and foundry technology, allows not only to adjust the microstructure, but also to fuse un-melted particles and generate "kissing bonds"). As shown in Fig. 16, after machining, the surface microcrack sources of parts are removed, enhancing the fatigue cycle of a part. The heat treatment process merely improves the microstructure of the part, but does not reduce or eliminate the defects. In this regard, the process can hardly improve the fatigue life of the parts. However, the HIP process may collapse the defects up to a certain size at an elevated temperature and pressure, reducing the number and size of the defects, and therefore improving the fatigue life of a part.
Fatigue life of the parts subjected to different post-processes [63]
Leuders et al [52, 63, 73] studied the mechanical properties and the growth mechanisms of fatigue cracks in the SLM titanium parts. Their results indicated that defects had a major impact on the fatigue life of the parts, especially at the stage of fatigue crack initiation. Due to the presence of defects, stress concentration could occur, causing crack initiation and consequently a decrease in fatigue strength. Leuders et al also analyzed the effect of defect location on the fatigue strength in their research. When a defect was located near the surface of a part, its fatigue life was shorter in comparison with that located far from the surface, indicating that defect location is critical to the fatigue strength of the part. Surface treatment, such as machining and shot peening, can be adopted to suppress or eliminate the near-surface defects so as to enhance part fatigue strength.
However, since it is difficult to accurately control the type, number, and location of a defect in a fabricated part, the fatigue strength of a part can be in jeopardy. Therefore, the fatigue strength of an SLM fabricated part is still questionable and needs to be improved.
Strategies for Defect Suppression
Defect suppression is a challenging issue in the SLM process. Currently, there are two major strategies to suppress defect formation in the SLM processes, namely online detection and numerical simulation, in addition to machining to reduce or eliminate defects.
Clijsters et al [74] designed a high-speed and real-time molten pool monitoring system, consisting of four modules, namely optical set-up, data processing, reference data and quality estimation. For each layer of deposition, the information of molten pool in the form of a light signal was collected by sensors, then transferred to a data processing module to establish the molten pool image, then used to analyze the location and size of defects compared with reference data to get the characteristics of molten pool to deduce defect formation information. Finally, the analysis results were used for the feedback control to optimize the process, and to reduce defect formation in the SLM fabricated parts.
Panwisawas et al [75] established a mathematical model of thermal fluid dynamics to better understand the morphological evolution of porosity during an SLM process. According to the deposition mechanism of the heating-melting-solidification cycles of metal powders, a thermal fluid dynamics model based on the Navier-Stokes equation, surface tension, capillary force, and Marangoni effect was introduced to explore the evolution of porosity as the scan speed increased. The results showed that for a fixed laser input power, increasing scan speed reduced energy input density, resulting in serious unfused defects in the interlayers.
It is an effective research strategy to combine the three methods, i.e., the traditional optimization test, the numerical simulation calculation and the online detection, for a systematic study on the defect formation and control in the SLM processes. As shown in Fig. 17, online detection is conducted for obtaining information on defect morphology, location and dimensions through detection sensors, data processing, image analysis and feedback control. The detected defects can be eliminated by the successive subtractive process. On the other hand, the strategy should also investigate defect formation and evolution mechanisms, including material melt-flow behavior, solidification and shrinkage, the interaction effect of surface tension, capillary force and gravity, by using the numerical simulation method. Finally, combining the information on defect detection and defect formation mechanisms to further accomplish the process optimization to achieve the objective of defect suppression and control in an SLM process.
Schematic illustration of defect detection and control in an SLM process
Defect formation is a critical problem in the SLM processes. It has a significant influence on the real-world application of the SLM fabricated parts. This paper reviews defect formation mechanisms in SLM processes, discusses the effect of process parameters on defect formation, and proposes a strategy for defect suppression and control. Based on the review, the paper summarizes conclusions:
The common defects are three types, namely spherical porosities, irregularly incomplete fusion holes, and cracks. Spherical porosities are randomly distributed, while incomplete fusion holes are generally distributed between the tracks and layers.
Many process parameters, such as laser power, scan speed, hatch spacing, layer thickness, and scan strategy, have significant influences on the formation of defects. Energy density is an integrated parameter for controlling defect formation; scan strategy has a significant influence on the location distribution of defects, most of the defects distribute at both ends of scan tracks and in between two adjacent tracks.
Defect formation has a significant influence on the mechanical properties of the SLM fabricated parts, especially fatigue strength. Defects play a prominent role in fatigue crack initiation, directly reduce the fatigue life of a part, which restricts the application of the SLM technique.
The quality control in an SLM process relies on defect detection and elimination. For high quality SLM fabrications, defect monitoring, simulation and modeling, as well as real-time defect elimination become necessary. Defect-free SLM fabrications are anticipated in the near future.
An erratum to this article has been published.
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CARTER L N, ESSA K, ATTALLAH M M. Optimization of selective laser melting for a high temperature Ni-superalloy. Rapid Prototyping Journal, 2015, 21(4): 423-432.
QIU C L, ADKINS N J E, ATTALLAH M M. Microstructure and tensile properties of selectively laser-melted and of HIPed laser-melted Ti6Al4 V. Materials Science and Engineering: A, 2013, 578: 230-239.
GONG H J, RAFI K, GU H F, et al. Analysis of defect generation in Ti6Al4 V parts made using powder bed fusion additive manufacturing processes. Additive Manufacturing, 2014, 1-4: 87-98.
RAFI H K, KARTHIK N V, Gong H J, et al. Microstructures and mechanical properties of Ti6Al4 V parts fabricated by selective laser melting and electron beam melting. Journal of Materials Engineering and Performance, 2013, 22(12): 3872-3883.
WEINGARTEN C, BUCHBINDER D, PIRCH N, et al. Formation and reduction of hydrogen porosity during selective laser melting of AlSi10 Mg. Journal of Materials Processing Technology, 2015, 221: 112-120.
ROLINKG, VOGT S, SENCEKOVA L, et al. Laser metal deposition and selective laser melting of Fe-28 at.% Al. Journal of Materials Research, 2014, 29(17): 2036-2043.
WANG L, WEI Q S, HE W T, et al. Influence of powder characteristic and process parameters on SLM formability. Journal of HuaZhong University of Science and Technology (Natural Science Edition), 2012, 40(6): 20-23.
WEN S F, LI S, WEI Q S, et al. Effect of molten pool boundaries on the mechanical properties of selective laser melting parts. Journal of Materials Processing Technology, 2014, 214(11): 2660-2667.
WU W H, YANG Y Q, WANG D. Balling phenomenon in selective laser melting process. Journal of South China University of Technology (Natural Science Edition), 2010(5): 110-115.
GU D D, SHEN Y F. Balling phenomena in direct laser sintering of stainless steel powder: metallurgical mechanisms and control methods. Materials & Design, 2009, 30(8): 2903-2910.
LIU Q C, ELAMBASSERIL J, SUN S J, et al. The effect of manufacturing defects on the fatigue behavior of Ti6Al4 V specimens fabricated using selective laser melting. Advanced Materials Research, 2014, 891-892: 1519-1524.
ZHOU X, WANG D, LIU X, et al. 3D-imaging of selective laser melting defects in a Co-Cr-Mo alloy by synchrotron radiation micro-CT. Acta Materialia, 2015, 98: 1-16.
READ N, WANG W, ESSA K, et al. Selective laser melting of AlSi10 Mg alloy: process optimization and mechanical properties development. Materials & Design, 2015, 65: 417-424.
ZHANG S, GUI R Z, WEI Q S, et al. Cracking behavior and formation mechanism of TC4 alloy formed by selective laser melting. Journal of Mechanical Engineering, 2013, 49(23): 21-27. (in Chinese)
LI R D, SHI Y S, WANG Z G, et al. Densification behavior of gas and water atomized 316L stainless steel powder during selective laser melting. Applied Surface Science, 2010, 256(13): 4350-4356.
ZHAO X, LIN X, CHEN J, et al. The effect of hot isostatic pressing on crack healing, microstructure, mechanical properties of Rene88DT superalloy prepared by laser solid forming. Materials Science and Engineering: A, 2009, 504(1-2): 129-134.
CHEN J, LIN X, WANG T, et al. The hot cracking mechanism of 316L stainless steel cladding in rapid laser forming process. Rare Metal Materials and Engineering, 2003, 32(23): 183-186.
HABOUDOU A, PEYRE P, VANNES A B, et al. Reduction of porosity content generated during Nd:YAG laser welding of A356 and AA5083 aluminum alloys. Materials Science and Engineering: A, 2003, 363(1-2): 40-52.
CARTER L N, WANG X, READ N, et al. Process optimization of selective laser melting using energy density model for nickel based superalloys. Materials Science and Technology, 2015: 1-5.
YADROITSEV I, BERTRAND P, SMUROV I. Parametric analysis of the selective laser melting process. Applied Surface Science, 2007, 253(19): 8064-8069.
GONG H J, RAFI K, GU H F, et al. Influence of defects on mechanical properties of Ti6Al4 V components produced by selective laser melting and electron beam melting. Materials & Design, 2015, 86: 545-554.
XU W, BRANDT M, SUN S, et al. Additive manufacturing of strong and ductile Ti6Al4 V by selective laser melting via in situ martensite decomposition. Acta Materialia, 2015, 85: 74-84.
ZHANG S, WEI Q S, CHENG L Y, et al. Effects of scan line spacing on pore characteristics and mechanical properties of porous Ti6Al4 V implants fabricated by selective laser melting. Materials & Design, 2014, 63: 185-193.
SONG B, DONG S J, ZHANG B C, et al. Effects of processing parameters on microstructure and mechanical property of selective laser melted Ti6Al4 V. Materials & Design, 2012, 35: 120-125.
VANDENBROUCKE B, KRUTH J. Selective laser melting of biocompatible metals for rapid manufacturing of medical parts. Rapid Prototyping Journal, 2007, 13(4): 196-203.
LEUDERS S, LIENEKE T, LAMMERS S, et al. On the fatigue properties of metals manufactured by selective laser melting-the role of ductility. Journal of Materials Research, 2014, 29(17): 1911-1919.
WANG D, YANG Y Q, SU X B, et al. Study on energy input and its influences on single-track, multi-track, and multi-layer in SLM. The International Journal of Advanced Manufacturing Technology, 2012, 58(9-12): 1189-1199.
KURZYNOWSKI T, CHLEBUS E, KUZNICKA B, et al. Parameters in selective laser melting for processing metallic powders. Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, 2012:823914-823914-6.
KEMPEN K, THIJS L, YASA E, et al. Process optimization and microstructural analysis for selective laser melting of AlSi10 Mg. Proceedings Solid Freeform Fabrication Symposium, Texas, USA. 2011
KEMPEN K, THIJS L, VAN H J, et al. Mechanical properties of AlSi10 Mg produced by selective laser melting. Physics Procedia, 2012, 39: 439-446.
MASKERY I, ABOULKHAIR N T, CORFIELD M R, et al. Quantification and characterization of porosity in selectively laser melted Al-Si10-Mg using X-ray computed tomography. Materials Characterization, 2016, 111: 193-204.
BAUEREISS A, SCHAROWSKY T, KOERNER C. Defect generation and propagation mechanism during additive manufacturing by selective beam melting. Journal of Materials Processing Technology, 2014, 214(11): 2522-2528.
WANG D, YANG Y Q, HUANG Y L, et al. Density improvement of metal parts directly fabricated via selective laser melting. Journal of South University of Technology (Natural Science Edition), 2010(6): 107-111.
YANG Y Q, SONG C H, WANG D. Selective laser melting and its application on personalized medical parts. Journal of Mechanical Engineering, 2014(21): 140-151.
ATTAR H, CALIN M, ZHANG L C, et al. Manufacture by selective laser melting and mechanical behavior of commercially pure titanium. Materials Science and Engineering: A, 2014, 593: 170-177.
SIMONELLI M, TSE Y Y, TUCK C. Effect of the build orientation on the mechanical properties and fracture modes of SLM Ti-6Al-4 V. Materials Science and Engineering: A, 2014, 616: 1-11.
LEUDERS S, THONE M, RIEMER A, et al. On the mechanical behavior of titanium alloy TiAl6V4 manufactured by selective laser melting: fatigue resistance and crack growth performance. International Journal of Fatigue, 2013, 48: 300-307.
FACCHINI L, MAGALINI E, ROBOTTI P, et al. Ductility of a Ti6Al4 V alloy produced by selective laser melting of pre-alloyed powders. Rapid Prototyping Journal, 2010, 16(6): 450-459.
KASPEROVICH G, HAUSMANN J. Improvement of fatigue resistance and ductility of TiAl6V4 processed by selective laser melting. Journal of Materials Processing Technology, 2015, 220: 202-214.
WU M W, LAI P, CHEN J. Anisotropy in the impact toughness of selective laser melted Ti6Al4 V alloy. Materials Science and Engineering: A. 2016, 650: 295-299.
CHLEBUS E, KUZNICKA B, KURZYNOWSK T, et al. Microstructure and mechanical behavior of Ti6Al7Nb alloy produced by selective laser melting. Materials Characterization, 2011, 62(5): 488-495.
EDWARDS P, RAMULU M. Fatigue performance evaluation of selective laser melted Ti6Al4 V. Materials Science and Engineering: A, 2014, 598: 327-337.
HOOREWEDER B V, BOONEN R, MOENS D, et al. On the determination of fatigue properties of Ti6Al4 V produced by selective laser melting. Journal of Thermal Analysis & Calorimetry, 2013, 113(113): 97-103.
REKEDAL K D, LIU D. Fatigue Life of selective laser melted and hot isostatically pressed Ti6Al4 V absent of surface machining. 56th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, AIAA SciTech, AIAA 2015-0894.
WYCISK E, EMMELMANN C, SIDDIQUE S, et al. High cycle fatigue (HCF) performance of Ti6Al4 V alloy processed by selective laser melting. Advanced Materials Research, 2013, 816-817: 134-139.
WYCISK E, SOLBACH A, SIDDIQUE S, et al. Effects of defects in laser additive manufactured Ti6Al4 V on fatigue properties. Physics Procedia, 2014, 56: 371-378.
LEUDERS S, VOLLMER M, BRENNE F, et al. Fatigue strength prediction for titanium alloy TiAl6V4 manufactured by selective laser melting. Metallurgical & Materials Transactions A, 2015, 46A(9): 3816-3823.
CLIJSTERS S, CRAEGHS T, BULS S, et al. In situ quality control of the selective laser melting process using a high-speed, real-time melt pool monitoring system. The International Journal of Advanced Manufacturing Technology, 2014, 75(5-8): 1089-1101.
PANWISAWAS C, QIU C L, SOVANI Y, et al. On the role of thermal fluid dynamics into the evolution of porosity during selective laser melting. Scripta Materialia, 2015, 105: 14-17.
Key Laboratory for Precision and Non-traditional Machining Technology of Ministry of Education, Dalian University of Technology, Dalian, 116024, China
Bi Zhang
, Yongtao Li
& Qian Bai
Department of Mechanical Engineering, University of Connecticut, Storrs, CT, 06269, USA
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Correspondence to Bi Zhang.
Supported by National Natural Science Foundation of China (Grant No. 51605077), Science Challenge Project (Grant No. CKY2016212A506-0101) and Science Fund for Creative Research Groups of NSFC (Grant No. 51621064).
An erratum to this article is available at https://doi.org/10.1007/s10033-017-0184-3.
Zhang, B., Li, Y. & Bai, Q. Defect Formation Mechanisms in Selective Laser Melting: A Review. Chin. J. Mech. Eng. 30, 515–527 (2017) doi:10.1007/s10033-017-0121-5
Revised: 07 February 2017
Issue Date: May 2017


text:
NASA's Juno Scientists Discover 'Shallow Lightning' and 'Mushballs' Ammonia In Latest Jupiter Results
By NASA information center // August 6, 2020
shallow-lightning findings set to be published
New results from NASA's Juno mission at Jupiter suggest our solar system's largest planet is home to what's called "shallow lightning." (NASA image)
(NASA) – New results from NASA's Juno mission at Jupiter suggest our solar system's largest planet is home to what's called "shallow lightning." An unexpected form of electrical discharge, shallow lightning originates from clouds containing an ammonia-water solution, whereas lightning on Earth originates from water clouds.
Other new findings suggest the violent thunderstorms for which the gas giant is known may form slushy ammonia-rich hailstones Juno's science team calls "mushballs"; they theorize that mushballs essentially kidnap ammonia and water in the upper atmosphere and carry them into the depths of Jupiter's atmosphere.
The shallow-lightning findings will be published Thursday, Aug. 6, in the journal Nature, while the mushballs research is currently available online in the Journal of Geophysical Research: Planets.
Since NASA's Voyager mission first saw Jovian lightning flashes in 1979, it has been thought that the planet's lightning is similar to Earth's, occurring only in thunderstorms where water exists in all its phases – ice, liquid, and gas.
At Jupiter this would place the storms around 28 to 40 miles (45 to 65 kilometers) below the visible clouds, with temperatures that hover around 32 degrees Fahrenheit (0 degrees Celsius, the temperature at which water freezes).
Voyager saw lightning as bright spots on Jupiter's cloud tops, suggesting that the flashes originated in deep water clouds. But lightning flashes observed on Jupiter's dark side by Juno's Stellar Reference Unit tell a different story.
"Juno's close flybys of the cloud tops allowed us to see something surprising – smaller, shallower flashes – originating at much higher altitudes in Jupiter's atmosphere than previously assumed possible," said Heidi Becker, Juno's Radiation Monitoring Investigation lead at NASA's Jet Propulsion Laboratory in Southern California and the lead author of the Nature paper.
Becker and her team suggest that Jupiter's powerful thunderstorms fling water-ice crystals high up into the planet's atmosphere, over 16 miles (25 kilometers) above Jupiter's water clouds, where they encounter atmospheric ammonia vapor that melts the ice, forming a new ammonia-water solution.
At such lofty altitude, temperatures are below minus 126 degrees Fahrenheit (minus 88 degrees Celsius) – too cold for pure liquid water to exist.
"At these altitudes, the ammonia acts like an antifreeze, lowering the melting point of water ice and allowing the formation of a cloud with ammonia-water liquid," said Becker.(NASA image)
"At these altitudes, the ammonia acts like an antifreeze, lowering the melting point of water ice and allowing the formation of a cloud with ammonia-water liquid," said Becker.
"In this new state, falling droplets of ammonia-water liquid can collide with the upgoing water-ice crystals and electrify the clouds. This was a big surprise, as ammonia-water clouds do not exist on Earth."
The shallow lightning factors into another puzzle about the inner workings of Jupiter's atmosphere: Juno's Microwave Radiometer instrument discovered that ammonia was depleted – which is to say, missing – from most of Jupiter's atmosphere.
Even more puzzling was that the amount of ammonia changes as one moves within Jupiter's atmosphere.
"Previously, scientists realized there were small pockets of missing ammonia, but no one realized how deep these pockets went or that they covered most of Jupiter," said Scott Bolton, Juno's principal investigator at the Southwest Research Institute in San Antonio.
"We were struggling to explain the ammonia depletion with ammonia-water rain alone, but the rain couldn't go deep enough to match the observations. I realized a solid, like a hailstone, might go deeper and take up more ammonia. When Heidi discovered shallow lightning, we realized we had evidence that ammonia mixes with water high in the atmosphere, and thus the lightning was a key piece of the puzzle."
Jovian Mushballs
A second paper, released yesterday in the Journal of Geophysical Research: Planets, envisions the strange brew of 2/3 water and 1/3 ammonia gas that becomes the seed for Jovian hailstones, known as mushballs.
Consisting of layers of water-ammonia slush and ice covered by a thicker water-ice crust, mushballs are generated in a similar manner as hail is on Earth – by growing larger as they move up and down through the atmosphere.
"Eventually, the mushballs get so big, even the updrafts can't hold them, and they fall deeper into the atmosphere, encountering even warmer temperatures, where they eventually evaporate completely," said Tristan Guillot, a Juno co-investigator from the Université Côte d'Azur in Nice, France, and lead author of the second paper.
"Their action drags ammonia and water down to deep levels in the planet's atmosphere. That explains why we don't see much of it in these places with Juno's Microwave Radiometer." (NASA image)
"Their action drags ammonia and water down to deep levels in the planet's atmosphere. That explains why we don't see much of it in these places with Juno's Microwave Radiometer."
Understanding the meteorology of Jupiter enables us to develop theories of atmospheric dynamics for all the planets in our solar system as well as for the exoplanets being discovered outside our solar system.
Comparing how violent storms and atmospheric physics work across the solar system allows planetary scientists to test theories under different conditions.
More About the Mission
The solar-powered Jupiter explorer launched nine years ago today, on Aug. 5, 2011. And last month marked the fourth anniversary of its arrival at Jupiter. Since entering the gas giant's orbit, Juno has performed 27 science flybys and logged over 300 million miles (483 million kilometers).
JPL, a division of Caltech in Pasadena, California, manages the Juno mission for the principal investigator, Scott Bolton, of the Southwest Research Institute in San Antonio. Juno is part of NASA's New Frontiers Program, which is managed at NASA's Marshall Space Flight Center in Huntsville, Alabama, for the agency's Science Mission Directorate in Washington.
Lockheed Martin Space in Denver built and operates the spacecraft.
NASA Celebrates 8 Year Anniversary of Mars Curiosity Rover's Touch Down on Mars in 2012
Mickey Mantle Baseball Card Shatters 5-Month-Old Record, Sells For Astonishing $5.2 million

redpajama_set_name: RedPajamaCommonCrawl


text:
Fullers Builders
Eastbury Manor House
Eastbury Manor House is a Grade I listed building and was built by Clement Sysley during the reign of Elizabeth I.
After being the country house of gentry families for the earlier part of its history, by the 18th and 19th centuries Eastbury was inhabited by a succession of tenants whom used many of the areas as agricultural buildings. The house gradually fell into decay. One of its two octagonal stair turrets was pulled down in the early 19th century. It was in danger of complete demolition until 1918 when it was purchased by the National Trust.
Using our team of directly employed staff of craftsmen and craftswomen, and having successfully completed Phase II (1993), we were asked to undertake the final phase (Phase III) of the overall works. The contract span over 54 weeks and amounted to a value of approximately £1,250,000.
enquiries@fullersbuilders.co.uk
E17 9LE
© 2019 Fullers Builders


Served with your selection of rice, and a complimentary item.
Fresh garlic, chef's special sauce & sesame on the top.
No salt, oil or corn starch, low calories. All steamed with rice and sauce on the side.
Sliced chicken, beef, crabmeat, shrimp and roast pork with mixed vegetables in brown sauce. With rice.
Jumbo shrimp sauteed with broccoli,baby corn and mushroom in egg white sauce. With rice.
Tender beef and fresh shrimp in hot Hunan sauce. With rice. Hot and spicy.
Chicken, beef, shrimp and roast pork sauteed with mixed vegetable in house special sauce. With rice.
Seasoned seafood or oriental mixed vegetable, sauteed in white wine sauce. With rice.
Boneless chicken chunks marinated and quickly fried, all is sauteed with hot and spicy sweet sauce on top of broccoli. With rice. Hot and spicy.
Dark chicken meat specialty prepared and blended with a mouth watering brown sauce covered with sesame seeds. With rice.
Crunchy slices of beef with orange peel, hot pepper and vegetables in orange pepper and vegetable in a sweet hot sauce. With rice. Hot and spicy.
Chunks chicken, beef and shrimp deep fried crispy sauteed with mixed vegetable in chef's special sauce. With rice.
Served with pork fried rice or white rice and choice of side.
Served with pork fried rice or white rice and choice of side. Hot and spicy.


Amazing owl. I'm an old fan and an old friend. You probably don't remember, but I will never forget your music, and the things you told me that inspired you to play, because you inspire me to play....so please keep playing. It's beein 7-8 years since we've spoken. Keep up the good work. And don't ever lose your grace.
Really beautiful. The sound quality for your supporting melody notes was outstanding. You prominently brought out those beautiful counterpoint melodies, and your tone was really lovely. If you're looking for critiques, I found myself wanting to hear a bit more of the main melody. It's so hard to make the high melody sing sweetly, especially while giving it the force required to have some measure of sustainment and prominence. But I would suggest shifting the balance in the direction of the higher melody. Only my opinion, as I suppose it could be a matter of interpretation (and it also might be simply a recording issue, my guess is those higher tones don't record as well). I just found myself aching to hear it a bit more. But again, whew, beautifully done! Your hard work has paid off.
Yes, I guess interpretation is always in the ear of the listener... the player is the communicator and the listener the interpreter... as long as it's an enjoyable experience for both then the goal has been reached!
Very nice Owl .I like the way you put your own indervidual stamp on the style of playing it.Its as though you are singing it as "Owl from Australia" would.Great stuff and nice recording , no half measures as you say.Congratulations on your commitment to the Art of playing the Guitar and inspiring us other folks out here.
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text:
The Lynn Anderson Rose
Columbia Records KC 35445 | Released September 1978 | Peak Chart Position: n/a
Glenn & Lynn celebrating
Bucket To The South
THE LINER NOTES
Released in the fall of 1978, 'From The Inside' marks the fourth major career shift for Lynn Anderson; the first album in her long string of releases for Columbia with veteran guitarist and arranger Steve Gibson in the producer's chair. While very much his own man, with a stellar cred on The Row, it's clear early on that Gibson is drawing his production themes and arrangements straight from the handbook of none other than the architect of the Countrypolitan genre: Lynn's former husband and the shepherd of her career, Glenn Sutton.
Working with a mixed palette of material largely drawn from Nashville writers, Gibson's canvas for this twenty-fourth Lynn Anderson edition generally tends to pop colors, with traces of just enough pedal steel from Weldon Myrick, layered guitars from Shane Keister, and background vocals from Lisa Silver and Janie Fricke to ground each work on Music Row.
"Rising Above It All" was originally written as a duet by master tunesmiths Foster & Rice, and would eventually be covered by Conway & Loretta. But not before it became this LP's lead track and first single. A sweeping, and dramatic ballad, Lynn's vocal weaves through a lyric that rises from pain to hope, her voice the perfect complement for Gibson's lush and evocative production… a treatment carried over to the LP's second single and last track in the set, Johnny Christopher's "Last Love of My Life".
Balanced with a diverse collection of tracks, from Bob McDill's poetic folk melody "Love Me Back" to Barry Mann's anthemic, "Sometimes When We Touch", this seventeenth Columbia release would also be the last major label LP from Lynn to include a Liz Anderson title: "When You Marry For Money"; a simple waltz with her trademark lyric twist tied up neatly with Lynn's effortless vocal…the common thread that runs through every Lynn Anderson recording.
J Buck Ford
"Rising Above It All" / "Touch and Go" / "Bucket to the South" / "Sometimes When We Touch" / "From the Inside" / "I Know You're the Rain" / "Fairytale" / "When You Marry for Money" / "Love Me Back"
"Last Love of My Life"
© 2023 lynnandersonrosegarden.com. all rights reserved


Intensely colourful red lilieslovely guernsey lilies, vibrant read with contrasting stamens. a delight for late summer and early autumn and a prolific bloomer. a local favourite and something special and unusual for your display this year.
This stunning selection of fresh stargazer lilies is an ideal choice to make someone's day.
Vibrant red native liliesguernsey lilies are simply beautiful and grow prolifically everywhere. dark red with lovely pale tipped stamens, they are a delight. flowering in late summer to early autumn, they are a delight.
Bright coloured oriental and asiatic liliesprefers sheltered sitethis collection of lilies includes 10 oriental lilies and 10 asiatic lilies. both varieties have good all weather tolerance.


Reading how a 13-year-old shouted away a nearby mountain lion at a regional park in Glen Ellen this week reminded me yet again why hiking alone is not always the smartest choice.
Another reminder came a couple of weeks ago when I was about to pull into a trailhead in northern California at Whiskeytown Lake and saw a few bear cubs scurry across the road directly to where I was about to hike. If I had been with a big group, I might have headed in that direction anyway. Instead, without the power of numbers and being entirely unfamiliar with the trail, I and my companion headed elsewhere in that amazing park.
Don't mistake me – I find solo walks deep into canyons or up rugged mountainsides blissfully therapeutic. There's no better place sometimes for reflection, meditation, limit-testing, and just escapism from the daily grind. So when I do hike with a group, I've managed to find the space, physically and psychologically, to separate for some personal time. It's not the same as trekking out alone where you're in total control of your schedule, your path and every decision to be made, but there are perils to taking it solo.
Manage the risks smartly and chances are good that a hike by yourself will be uneventful, but I can't shake thinking about the tragic accounts of two hikers who headed into Mount Tam alone in recent weeks and never made it out alive. Those two stories are deeply disturbing and sobering.
However you manage it, having company on a trail can be a lifesaver. Literally.
I agree with the bliss and the solitude of a solitary hike but I was expecting some more practical tips than stay in sight of a group. He did not mention leaving information with anyone about expected route and return time to start a search if he disappears. How about taking a compass, a space blanket, waterproof matches, small first aid kit, cell phone (no service but the signal can be located), walking stick for defense/emergency splint, etc.? I would guess the author has more of these in mind than I do but it would be nice to hear his version.
– Know the path and area well.
– Tell someone where you're going and when you should be back.
– If there's a place to check in when you start, like a ranger station or bulletin board, do so.
– Check the weather carefully.
– Food, especially if blood sugar may be an issue.
as 'the OA' and NOT as "The Order"…..
the formation of the white supremacy group, we called it "the OA" and not "the Order." Maybe it had different monikers in different regions; my reference was in SF and the Bay area.
Purpose/focus	Paramilitary fomenting white nationalist revolution, against what they call the Zionist Occupation Government.


2.希望能够给大家带来帮助。让患者朋友看到希望和光明。这时你一定会感受到他的浑身战栗。然后慢慢蹲下,但是这两类疾病却有着明显的区别,具有强迫性人格的人常常具有这样一些特点:胆小怕事、优柔寡断、做事小心谨慎、生活习惯一成不变、喜欢胡思乱想等。 It must be said that the UEFA Championship has not made it to the Santiago Bernabeu since Real Madrid won the title in 2002. but they are also the base of Spain's National team. whose MMA gloves feature an exclusive Y shape volar design so that the glove stays tight whether the hands are open or clenched in a fist.
Copyright 2017-2023 http://www.109wife.com All Rights Reserved.


Forum » Gifting Driftmoon preorders?
Is it possible to buy someone a Driftmoon preorder as a gift (i.e. there's a "gift" option during the buying process, or the email address used to purchase the game is irrelevant)? Is it possible to buy someone a Driftmoon preorder as a gift (i.e. there's a "gift" option during the buying process, or the email address used to purchase the game is irrelevant)?
The easiest way is to buy it to yourself, and just email me (ville@monkkonen.net), and I'll change the ownership to whomever you wish. I'll need a name and an email for the new owner.


Orangerecipes.org - Orange City Housing Authority. A sauce prepared with orange juice and orange zest gives this chicken dish that special tang. A great idea to enhance your everyday chicken recipe.
Looking for recipes on how to make sorbets and ices? Look no more, you will find here a list of ices recipes that are not only delicious but also healthy and suitable for diabetics. This is often similar to Orange City Housing Authority.
Relevant to Orange City Housing Authority, Sipping your favorite strawberry smoothie on a very stifling day would be a great thing to do. Savoring its rich, fruity, and refreshing taste will certainly make your day splendid. It is also a great thing to know that this kind of beverage does not only offer great thirst-quenching taste but also nutrients which are proven to be highly beneficial to your health.


Okay, "Rights: The bureaucracy of ethics" is an album title, not a band name. I admit it.
You can't always get them to do what you'd like. But their powers are awesome.
There's always at least one on the table at the party.
It's not just at home on the range.


http://media.blubrry.com/audiotidbitspodcast/p/www.garycrow.net/audio/YoungPessimist.mp3Podcast: DownloadSubscribe: Apple Podcasts | Android | Email | Google Podcasts | Stitcher | TuneIn | RSSDo you think optimism and pessimism are a choice we all can and do make? It's our world and how we look at it are up to us? Would it were true. Listen and decide for yourself.
http://media.blubrry.com/audiotidbitspodcast/p/www.garycrow.net/audio/AlienConvert.mp3Podcast: DownloadSubscribe: Apple Podcasts | Android | Email | Google Podcasts | Stitcher | TuneIn | RSSThe Earth people have landed in a far away place with no hope of returning to Earth. The natives are not happy to see them. Please listen now to learn the outcome.
http://media.blubrry.com/audiotidbitspodcast/p/www.garycrow.net/audio/htm163.mp3Podcast: DownloadSubscribe: Apple Podcasts | Android | Email | Google Podcasts | Stitcher | TuneIn | RSSMany things don't mix but none quite so much so as love and power. It is thus surprising how often people try to mix the two or at least profess to be trying. It's worth a listen.
http://media.blubrry.com/audiotidbitspodcast/p/www.garycrow.net/audio/htm161.mp3Podcast: DownloadSubscribe: Apple Podcasts | Android | Email | Google Podcasts | Stitcher | TuneIn | RSSIts lady's day at the How To Matter headquarters. The women have taken over the HTM microphone for this idea generator session. Please listen to hear their take on several interesting topics.
http://media.blubrry.com/audiotidbitspodcast/p/www.garycrow.net/audio/ditty.mp3Podcast: DownloadSubscribe: Apple Podcasts | Android | Email | Google Podcasts | Stitcher | TuneIn | RSSListen to see what happens when a simple little ditty meets convolution reverb. It may well be magic.


text:
From Cotton and Smoke
Łódź – Industrial City and Discourses of Asynchronous Modernity, 1897–1994
Agata Zysiak, Kamil Śmiechowski, Kamil Piskała, Wiktor Marzec, Kaja Kaźmierska, and Jacek Burski
Pub Date: May 2019
This book considers Łódź as the capital of the Polish nineteenth century, and the history of this former textile hub, which now finds itself in central Poland, as one of struggle with modern change in Eastern Europe. The authors boldly challenge the romantic and noble-based Polish cultural imaginary, offering instead a revolutionary path to understanding confrontation with modernity in the region.
The book examines local press debates during four pivotal periods, each of which stimulated self-reflection on the idea of the modern city:
Rapid industrial growth in the tsarist borderlands;
State crafting after WWI;
Socialist restructuring after 1945;
Transition and deindustrialization after 1989.
Together these insights constitute a multifaceted portrait of twentieth-century urban experience beyond the metropolis, in different historical contexts.
This innovative, interdisciplinary work deftly integrates urban and cultural history, historical sociology and discourse research. It will be of great value to Polish and Jewish studies specialists, as well as those in the field of Eastern European and Slavic studies. The book also addresses core intellectual debates within urban studies, modernity studies, and historical discourse analysis worldwide.
This book aptly addresses current academic debates on the historical sociology of Eastern Europe. The case of Łódź serves the purpose of enriching the typologies and enhancing existing knowledge of the idiosyncratic modernization process that has been variously situated on the center-peripheries axis of the global capitalist system. This is an innovative work. It addresses an important topic in a new, interdisciplinary manner. The main theme will be of considerable interest to the global reader concerned with urban modernity. Agnieszka Kolasa Nowak, professor of sociology, Maria Skłodowska Curie University, Lublin
This book moves the capital of the nineteenth century. Paralleling the switch of focus from Baudelairian Paris to industrial Manchester, it places the capital of the Polish nineteenth century in the textile industrial hub—Łódź. This is still a revolutionary gesture within Polish studies. The authors have aptly located their particular case study within a broader framework of modernity studies. Deftly integrating broad historical queries of the daily press and theoretical reasoning, they have succeeded in relating the imaginaries and normative orders present among journalists to the expert discourses and agendas of institutional actors. Tomasz Majewski, professor of cultural studies, Jagiellonian University, Cracow
JACEK BURSKI, sociologist, is a research assistant at the Department of Sociology of Culture at the University of Łódź; he is preparing a PhD thesis about the social world of football fans in Poland.
KAJA KAŹMIERSKA is a sociologist. An associate professor, she is the director of the Institute of Sociology and head of the Department of the Sociology of Culture at the University of Łódź. Her research interests include: biographical analysis, collective/national identity and memory, migration, borderland identity formation, European identity formation, the sociological analysis of civil society organization activities, and studies on Jewish identity.
WIKTOR MARZEC holds a PhD in sociology and social anthropology from the Central European University in Budapest, an MA in sociology, and an MA in philosophy from the University of Łódź. His research interests concern historical sociology, labor history, and conceptual history.
KAMIL PISKAŁA is a historian and holds a PhD in contemporary Polish history. He graduated from the University of Łódź in 2017. His research interests are focused on the history of labor movements and socialist ideology in the twentieth century, people's history, and political ideas.
KAMIL ŚMIECHOWSKI is a historian. He holds a PhD in the history of Poland, and graduated from the University of Łódź in 2013. He works as an associate professor at the Institute of History and is the secretary of the Interdisciplinary Urban Studies Center, the University of Łódź. His research interests are focused on urban theory, analyses of press discourse, processes of modernization in nineteenth- and twentieth-century Poland, and the history of Łódź. Currently, he is working on a post-doc research project about the discourse of the urban in the Kingdom of Poland at the turn of the twentieth century.
AGATA ZYSIAK is a historical sociologist. She is an assistant professor at the University of Łódź, working on postwar Poland, modernization, and industrial cities. She is a member of the Institute for Advanced Study, Princeton 2017-2018. She also works at the University of Warsaw comparing urban decline in Detroit and Łódź.


text:
Q: Post form data using Fetch in Redux-saga var formData = new FormData(loginRequestObject);
formData.append('userName', loginRequestObject.username);
formData.append('password', loginRequestObject.password);
formData.append('mobile', loginRequestObject.mobile);
formData.append('deviceid', deviceInfo.getDeviceId())

This is the request What I am making-
and in body part
  try{
const response = yield call(fetch, Url, {
  method : 'POST',
  headers : {
    'Accept': 'application/json, application/xml, text/plain, text/html, *.*',
    'Content-Type' :'multipart/form-data, application/x-www-form-urlencoded; charset=utf-8'
  },
  body : formData
})
if(response.ok) {
  const jsonResponse = yield response.text()
  yield put(LoginActions.loginSuccess(jsonResponse))
} else {
  const jsonResponse = yield response.text();
  yield put(LoginActions.loginFailure(jsonResponse))
}

I am making this request to post the data but I'm not able to do , what is the reason?

A: First of all, there is no promise function handling the response of your POST request. What error are you getting with this implemented code? Why are you using multipart/form-data when you are not sending data in multiple parts? From your code it doesn't look like you are sending the image data for which you need multipart.
Your question doesn't provide enough details to provide any specific answer, please explain it with more details about the error you are getting.

A: I think you should wrap fetch function with another function, this is a demo for you
const fetchFunc = ({ url, options }) => {
   return fetch(url, options);
}

const response = yield call(fetchFunc, {
     url: Url,
     options {
        method : 'POST',
        headers : {
          'Accept': 'application/json, application/xml, text/plain, text/html, *.*',
          'Content-Type' :'multipart/form-data, application/x-www-form-urlencoded;charset=utf-8',
        },
        body : formData
    }
});
if(response.ok) {
   const jsonResponse = yield response.text()
   yield put(LoginActions.loginSuccess(jsonResponse))
} else {
   const jsonResponse = yield response.text();
   yield put(LoginActions.loginFailure(jsonResponse))
}

A: Just I have removed the Content-Type and it has worked.

redpajama_set_name: RedPajamaStackExchange


text:
Ferenc Hopp Museum of Asiatic Arts is an art museum in Budapest, Hungary.

External links

Museums in Budapest
Art museums and galleries in Hungary
Asian art museums in Hungary

redpajama_set_name: RedPajamaWikipedia


text:
EG6800 Number Plate
EG6800 Number Plate From Regplates.com
In 1982, the previously implemented number system had made it all the way to Y. To avoid running out of plates, the system was once again reversed making the new series A21 AAA ending at Y999 YYY. The plates began at 21 as the first 20 were kept for government vehicles to use. There was discussion throughout the 1990s about developing a Europe wide set of number plate rules. This would include a country code on each license plate. However, there was a lack of interest from several countries so the idea was put to a halt.
For example, the amount of money raised by the DVLA through the sale of personalised number plates more than doubled over three years, reaching over £162 million in the 2017/18 financial year.
SCT 65
7 GAS


text:
Hayward & Lodge
4.16 | 91 ratings
"Blue Jays" is a Moody Blues album in all but name. After the release of the Moody Blues "Seventh Sojourn" album in 1972, their record company Decca were clamouring for another album. The five Moodies couldn't come to an agreement on the next album, so the two frontmen of the Moody Blues, Justin Hayward & John Lodge, set out on their own to record the "Blue Jays" album with producer Tony Clarke at the helm. The end result would turn out to be a symphonic masterpiece on a par with the Moody Blues classically-inspired "Days of Future Passed" (1967) album, which featured the anthemic "Nights in White Satin". The original "Blue Jays" album released in 1975 didn't contain the magnificent song "Blue Guitar", which was released as a single around the same time as the album. This omission was later rectified when "Blue Guitar" was added to the album in the 1987 re-issue and again on the 2004 remastered CD. All of the songs on the album were written by Justin Hayward & John Lodge.
"This Morning" opens this magnificent album in true Moody Blues style with sweeping symphonic soundscapes and the familiar heartfelt tones of Justin Hayward, as he imploringly sings, "As the dawn is breaking on your future my child, Is there none of your love alive?, If every door you open closes on me, I don't know if I can survive." The production and orchestration on this opening song is just superb. It's a masterly demonstration of the art of the producer and it sets the tone for the album as a whole, where you know you're in for a real symphonic treat. "Remember Me (My Friend)" is another magnificently orchestrated ballad with Justin Hayward's beseeching words asking, "I am your friend, You must remember me, I'm the one who saw through the world's disguise, Took away its cloak and made it hide from me, Remember me?" The lovely harmonies and sweeping orchestration are just awesome, with the trademark sound of Justin Hayward's superb guitar always there to remind you that this is really a Moody Blues album. The pace slows down a bit for the next song "My Brother", a gentle ballad with those Oh-So-Beautiful harmonies at the forefront again and masterly orchestration from producer Tony Clarke. who also produced all of the Moody Blues albums between 1967 and 1979. Continuing this magic carpet ride on a symphony of sound is "You", a romantic song of love gone sour with these words from balladeer Justin Hayward, "You don't even know my name, Time was when you would take the love you've given all away, Take a part of me, You don't even walk my road, Can't find where you turned, Looked away and you were gone." ..... These are the kind of melancholy heart-wrenching songs that have become Justin Hayward's trademark speciality and his beseeching voice always has that urgent emotional appeal that never fails to tug at the heartstrings. "Nights Winters Years" rounds off Side One in magnificent style. It's a fully orchestrated symphonic epic in the style of "Nights in White Satin", only more so. If you haven't been transported to a magical place before now, then this song will take you there. Prepare to be amazed by this epic production of dynamic proportions! Side Two opens with the most up-tempo rocker on the album, the uplifting "Saved by the Music", although the song does have its quiet reflective moments too. "I Dreamed Last Night" follows next. This sweeping symphonic masterpiece is another emotional rollercoaster ride, guaranteed to tug at the heartstrings with its tale of lost love, where Justin Hayward opens the song with these imploring words, "Oh, I dreamed last night, I was hearing, hearing your voice, And the things that you said, Well, they left me, left me no choice." There aren't many singers of Justin Hayward's calibre who are capable of pouring so much emotion into a bittersweet romantic ballad. "Who Are You Now" is a nice gentle acoustic guitar-driven ballad with the ever- present lush orchestration from Moody Blues producer Tony Clarke. You'd have to be as emotionless as Mr. Spock in Star Trek not to be touched by the powerful emotional appeal in all of the heartfelt songs on this wonderful album. If you're in the mood for some full-blown classically inspired symphonic music, then "Maybe" this next song is for you. Just lie back and let this beautiful music carry you away to an ocean of harmonic serenity. This is the music that dreams are made of. Finally, we come to the album closer, "When We Wake Up" which seems an appropriate title, bearing in mind coming to the end of this album is like waking from a beautiful dream. As you'd expect from two-fifths of the Moody Blues, this is a full-blown symphonic masterpiece of lush orchestration with everything but the kitchen sink thrown into the mix.
This is truly an outstanding album which reaches the parts that other albums fail to reach. "Blue Jays" is an album that's guaranteed to linger longer in the memory with its timeless romantic ballads with everlasting appeal for generations to come. If you're a hopeless romantic, or just hopeless at romance, then this is the album for you. An absolute must-have album for any fans of the Moody Blues. In comparison with other Moody Blues albums, this solo endeavour from Justin Hayward & John Lodge ranks as one of their finest albums. This album is a master-class in production technique and represents one of the pinnacles of classic 1970's Symphonic Rock.
Psychedelic Paul | 5/5 | 2019-11-13
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text:
NW TERRITORIES
Welcome to the most comprehensive online travel guide for Alaska, Western Canada and Northwest USA
60th Parallel Visitors Centre
Bears in NWT
Deh Cho Region
Fort Liard
Fort Providence
Highways and Winter Roads
Hwy 1 - Mackenzie Highway
Hwy 2 - Hay River Highway
Hwy 3 - Yellowknife Highway
Hwy 4 - Ingraham Trail
Hwy 5 - Fort Smith Highway
Hwy 6 - Fort Resolution Hwy
Hwy 7 - Liard Highway
Hwy 8 - Dempster Highway
Jean Marie River
Kakisa
Nahanni Butte
Nahanni National Park
North Slave Region
NWT Intro
Sahtu Region
South Slave Region
Western Arctic Region
Wood Buffalo National Park
Hay River Google Map from here to Bears in NWTDeh Cho RegionEnterpriseFort LiardFort ProvidenceFort SimpsonFort SmithHay RiverHwy 7 - Liard HighwayInuvikJean Marie RiverKakisaNahanni ButteNUNAVUTNWT IntroWrigleyYellowknife
Location: Situated on the south shore of Great Slave Lake at the north end of Hwy 2; 462 miles northwest of Grande Prairie, AB; 296 miles south of Yellowknife and 70 miles north of Alberta border. Scheduled air service daily from Edmonton (638 miles) and other points, with summertime barge service to the northern communities via Hay River access. Charter plane service is available, including sightseeing or fishing excursions. Population: 3734. Visitor Information: Hay River Visitor Information Centre, 923 Mackenzie Hwy at McBryan Drive; Phone: (867) 874-3180; Website: www.hayriver.com/tourism. Hay River Chamber of Commerce, Suite K, 10 Gagnier Street, Hay River, Northwest Territories X0E 0R0; Phone: (867) 874-2565; Website: www.hayriverchamber.com
The Hay River area was originally a rich hunting and fishing ground for the Slavey Dene people who traveled up to the edge of Great Slave Lake each year and returned south before winter set in. In 1868, an Oblate Mission and a Hudson's Bay Company fur trading post were established on Hay River. A small group of Slavey people led by Chief Chiatlo settled permanently at the location around 1890. An Anglican mission was built in 1893, followed in the early 1900s by St. Peter's Church, which eventually included the residential school for the Diocese of Mackenzie, and St. Anne's Roman Catholic Church. The town and its missions were located near the centre of a 4000-kilometre inland water route that extended north of Edmonton from Athabaska Landing to the Arctic Ocean. This route was the main means by which the western region of the Northwest Territories was opened up to Euro-Canadian influence and development. Hay River remains an important barge port for the entire Mackenzie River system all the way to the Beaufort Sea. In 1939, a trail was opened from Grimshaw, Alberta to Hay River to supply the gold mines in Yellowknife, and the first cat trains were established to haul freight. This initiated the development of the commercial fishery on Great Slave Lake, and fishing families began to settle on Vale Island in the late 1930s and on the west channel in 1949. As part of the Canol Road project, the US Army Corps of Engineers built a runway on Vale Island during WWII, and by 1964 a rail line was extended from Grimshaw to Hay River to facilitate the zinc/lead mine in Pine Point on Hwy 5.
Two Dene First Nations bands live near Hay River, providing a strong continuum of aboriginal culture and tradition. The West Point First Nations group is an independent community on Vale Island, where an original fishing village was located. Some of those first families still fish and live in the village today. The K'atl'odeeche First Nations Reserve is located on the east side of Hay River and is the only reserve in the Northwest Territories. Several festivals are hosted by these communities, including Treaty Day on June 11th, National Aboriginal Day on June 21st and the K'amba Winter Carnival at the beginning of March. The Dene inhabiting the vast reaches of the north all the way to the Arctic coast have a rich and diversified culture, which has been preserved for thousands of years in their strong oral traditions and lifestyle. The Dene Cultural Institute, or Yamozha Kue, works to continue this heritage and to share it with others. The building was designed on the advice of Dene elders and is based on the legends of Yamoria, an important figure in Dene history. The Hay River Heritage Centre, located in the old Hudson's Bay store on Vale Island, offers exhibits which capture the rich natural and human history of the region. Traditional fiddling and jigging contests are held at the Metis Friendship Centre and Soaring Eagle Friendship Centre. Part of the Trans Canada Trail system, Hay River has a network of more than 20 kilometers of trails offering scenic vistas of the river and interpretive signage on natural and cultural history.
Fishing on the Hay River begins shortly after the ice moves out, peaks in mid-June and lasts all summer. Walleye, northern pike and the feisty Arctic grayling are a common catch. Fishing on Great Slave Lake is almost year-round, only stopping in late fall until the lake has frozen over when nets are cast beneath the ice to capture the haul. While the lake is well known for its trophy lake trout and whitefish, there are also great stocks of goldeye and inconnu. During the spring, summer and fall, excellent fishing opportunities exist right in town. Cast from shore, rent a canoe for a leisurely paddle down river or embark from Vale Island at the Porritt Landing boat launch. With Great Slave Lake as base camp, the abundance of lakes and rivers in the entire South Slave Region may be thoroughly explored. Outfitters offer guided fishing tours on Great Slave Lake, to the legendary East Arm and other remote locations.
The Hay River Golf Club is a beautiful 9-hole course that has been carved out of the boreal forest and hugs the edge of picturesque Hay River. The well-maintained grass course and artificial grass greens will challenge any golfer. In the winter, the golf club transforms into the Nordic Ski Club, which offers several events and races throughout the season, with many kilometers of groomed trails for cross country skiing and snow shoeing, well lit for nighttime excursions. The Hay River snowmobile club provides maps for snowmobile exploration throughout town and in the forest along wildlife trails.
Hay River is situated directly in the Aurora Borealis viewing belt, with spectacular displays of Northern Lights commonplace between mid-August and October and again in February and March. An estimated one trillion watts of power are generated by the collision of solar winds and the earth's magnetosphere, hovering as little as 60 miles above the North Pole. The native Dene metaphysical explanation is that the power and beauty derive from the presence of spirits.
Tourists are offered accommodation and dining at several hotels, inns, bed and breakfast establishments and restaurants in Hay River. The area is a camper's paradise with two facilities for RV and tent camping within town on Vale Island at the Hay River Territorial Park near the public beach, and 10 electrified RV stalls at the Hay River Golf Club. Camping in the surrounding forest is accommodated at the following campgrounds: Twin Falls Gorge Park 30 miles south of Hay River at Louise and Alexandra Falls, Lady Evelyn Falls Park near the community of Kakisa and Little Buffalo River Territorial Park on Hwy 6 toward Fort Resolution. A short distance west of Hay River, Kakisa River and McNallie Creek Falls are among the numerous Day Use facilities located along Hwy 1. Most are maintained by the government and located in areas with historical significance.
Hay River celebrates the long days of summer with Hay Days Festival in early July. The festival features workshops, culture, art, food and music culminating with a Saturday night shaker, a 'wet event' on the shore of Great Slave Lake featuring live bands into the early hours of the morning. The Fisherman's Wharf is a popular meeting place on Saturdays from mid-June to September where locals and visitors can buy artisan crafts, vendor products and locally caught whitefish served with chips. In winter there is also much to do with the Aurora Ford dog sled race, polar pond hockey tournament, Rotary wine festival, figure skating ice carnival, Ptub x-country ski race and much more. For a listing of festivals and events throughout the year, visit the Town's website at hayriver.com.
The Visitor Information Centre is open year round, 7 days in summer and 5 in winter. It's a great place to shop for local artisan creations, use the free WiFi, enjoy a strong cup of coffee or speak with knowledgeable staff who will help make your stay an adventure to remember. Potable water and sewer dump are available at the VIC for your camper.
Gas Price Ticker For:
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Hay River tourism
© 2021 Travel Guide. All rights reserved. No part of this site may be reproduced without our written permission.


text:
Hakim Ludin (* 6. Mai 1955 in Kabul) ist ein afghanischer Percussionist.

Leben
In Afghanistan erhielt er sechs Jahre Tabla-Unterricht. Ludin kam 1975 nach Deutschland; er spielte mit der Avantgarde-Gruppe Sohra sowie in mehreren Jazz- und Rock-Formationen. Ab 1981 studierte er Schlagzeug und Percussion (Abschluss als Diplom-Orchestermusiker) an der Hochschule für Musik Karlsruhe. Er arbeitete  mit der hr-Bigband, Jeff Hamilton, Daniel Messina, Jonas Hellborg, Terry Bozzio, Alex Acuña sowie als Studiomusiker. Er veröffentlichte Lehrbücher über afro-kubanische und afro-brasilianische Rhythmen und tritt als Solo-Percussionist auf.

Ludin spielt in folgenden Projekten:
bei Koinoor mit Dave King,
dem  Global Jazz Trio,
dem  World Percussion Trio,
bei Planet Lounge,
im Trio mit Patrick Bebelaar und Frank Kroll sowie
im Duo Florian Meierott.
Mit Konstantin Wecker ging er auf Tournee, um das Album Am Flussufer (2005) vorzustellen. Im Jahr 2010 ging Ludin mit Hannes Wader, Konstantin Wecker, Nils Tuxen und Jo Barnikel auf die "Kein Ende in Sicht"-Tournee.

Diskografie
 The Silk Road 1996 (Bellaphon) mit Roland Schaeffer
 One World Percussion 1996
 Peace for Kabul mit Lenny MacDowell und Dhafer Youssef
 Electric Bolero 2002 mit Christoph Spendel
 Nazim 2005 mit Christoph Spendel
 Am Flussufer 2005 Mit Konstantin Wecker
 Am Flussufer Live in München  2005
 Kein Ende in Sicht Live-CD mit Hannes Wader, Konstantin Wecker, Nils Tuxen, Jo Barnikel

Weblinks

 Website von Hakim Ludin
 Kurzinterview (englisch)

Einzelnachweise

Perkussionist
Schlagzeuger
Person (Kabul)
Kultur (Afghanistan)
Afghane
Geboren 1955
Mann


text:
business94094.blog5.net
Marco1k Secrets
May 19, 2019 Category: Blog
Warning You will be utilizing a World-wide-web browser that we do not help. Our Web-site will never perform properly. Make sure you update to a more moderen Variation or down load a different World-wide-web browser, for instance Chrome or Firefox.
That artefact, and the later on IPK, happen to be the typical from the device of mass with the metric program at any time given that.
Conversely, an Digital definition of your kilogram (see § Electronic approaches, below), which might precisely deal with the Planck continual, would carry on to permit eighty three one⁄three moles of 12C to possess a mass of specifically a person kilogram but the volume of atoms comprising a mole (the Avogadro continuous) would go on to generally be subject matter to potential refinement.
Gravity and the nature of the Kibble equilibrium, which oscillates examination masses up and down versus the nearby gravitational acceleration g, are exploited to ensure mechanical power is in contrast versus electrical energy, that is the square of voltage divided by electrical resistance. Having said that, g varies substantially—by nearly one%—based upon in which on the Earth's surface area the measurement is built (see Earth's gravity). Additionally, there are slight seasonal variants in g at a spot on account of changes in underground drinking water tables, and bigger semimonthly and diurnal adjustments due to tidal distortions inside the Earth's condition brought on by the Moon plus the Sun. Despite the fact that g wouldn't be described as a term during the definition in the kilogram, It will be essential in the entire process of measurement of your kilogram when relating Electricity to ability. Accordingly, g have to be calculated with a minimum of just as much precision and precision as are the other terms, so measurements of g ought to even be traceable to basic constants of character.
One more Avogadro consistent-dependent tactic, often known as the Intercontinental Avogadro Coordination's Avogadro challenge, would define and delineate the kilogram like a 93.six mm diameter sphere of silicon atoms. Silicon was decided on mainly because a professional infrastructure with experienced procedures for developing defect-no cost, extremely-pure monocrystalline silicon now exists to company the semiconductor business. To produce a simple realization of the kilogram, a silicon boule (a rod-like, single-crystal ingot) could be manufactured. Its isotopic composition could well be calculated which has a mass spectrometer to ascertain its normal relative atomic mass.
It has been doable to rule out many explanations in the noticed divergences during the masses of the planet's prototypes proposed by researchers and most of the people. The BIPM's FAQ clarifies, by way of example, which the divergence is depending on the length of time elapsed involving measurements rather than dependent on the amount of periods the prototype or its copies are actually cleaned or feasible adjustments in gravity or natural environment.[sixty] Reports published in 2013 by Peter Cumpson of Newcastle University based on the X-ray photoelectron spectroscopy of samples that were saved together with different prototype kilograms instructed that one source of the divergence concerning the various prototypes may be traced to mercury that were absorbed via the prototypes becoming inside the proximity of mercury-dependent devices.
Exactly the same is legitimate regarding the actual-planet dependency over the kilogram: In case the mass of the IPK was located to get changed a little, there will be no automatic influence on the opposite models of evaluate because their realistic realizations offer an insulating layer of abstraction. Any discrepancy would sooner or later have to be reconciled however, because the virtue with the SI method is its exact mathematical and sensible harmony among its units. In case the IPK's benefit had been definitively demonstrated to have modified, a person Answer can be to easily redefine the kilogram as getting equivalent to the mass of the IPK in addition an offset value, likewise to what's currently completed with its replicas; e.g., "the kilogram is equal into the mass in the IPK + forty two pieces per billion" (reminiscent of 42 μg).
The IPK is rarely used or handled. Copies of your IPK kept by nationwide metrology laboratories world wide were being in contrast With all the IPK in 1889, 1948, and 1989 to offer traceability of measurements of mass everywhere in the world back again on the IPK.
While the burden of the item is depending on the power from the local gravitational field, the mass of the item is unbiased of gravity, as mass is often a measure of the quantity of matter. Appropriately, for astronauts in microgravity, no energy is required to carry objects off the cabin ground; They can be "weightless".
The varied copies on the Worldwide prototype kilogram are given the next designations inside the literature:
Family Whatsapp Group, a humorous relatable video about what all we knowledge in the WhatsApp team with our relations.
[Notice thirteen] Further more, the earth's countrywide metrology laboratories must anticipate the fourth periodic verification to confirm whether or not the historic developments persisted.
As an illustration, osmium-iridium alloys can be investigated if platinum's propensity to absorb hydrogen (as a result of catalysis of VOCs and hydrocarbon-dependent cleansing solvents) and atmospheric mercury proved to be sources of instability. Also, vapor-deposited, protecting ceramic coatings like nitrides could possibly be investigated for their suitability for chemically isolating these new alloys.
Accordingly, a provisional mass regular was produced as a single-piece, metallic artifact one 1kmg thousand instances as huge since the gram—the kilogram.
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