The harsh irradiation environment poses serious threat to the structural integrity of leading candidate for plasma-facing materials, tungsten (W), in future nuclear fusion reactors. It is thus essential to understand the radiation-induced segregation of native defects and impurities to defect sinks, such as grain boundaries (GBs), by quantifying the segregation energetics. In this work, molecular statics simulations of a range of equilibrium and metastable  symmetric tilt GBs are carried out to explore the energetics of vacancy segregation. We show that the low-angle GBs have larger absorption length scales over their high-angle counterparts. Vacancy sites that are energetically unfavorable for segregation are found in all GBs. The magnitudes of minimum segregation energies for the equilibrium GBs vary from −2.61 eV to −0.76 eV depending on the GB character, while those for the metastable GB states tend to be much lower. The significance of vacancy delocalization in decreasing the vacancy segregation energies and facilitating GB migration has been discussed. Metrics such as GB energy and local stress are used to interpret the simulation results, and correlations between them have been established. This study contributes to the possible application of polycrystalline W under irradiation in advanced nuclear fusion reactors.
Point defects are the simplest defects of materials. In non-equilibrium processes such as displacement cascades1,2,3,4, an excess of point defects can be created. The subsequent evolution of these point defects may lead to the formation of dislocation loops1,2,5 and voids6,7,8, which inevitably induces the degradation of mechanical properties, such as swelling, hardening, embrittlement and even direct failure. As an intrinsic two-dimensional defect in polycrystalline materials, grain boundary (GB), where grains with different crystallographic orientations join, has tremendous influence on the thermal, electrical and mechanical properties of materials. It has long been established that GBs can act as efficient sources or sinks for point defects2,9,10,11,12,13,14,15. This effect of absorbing or emitting point defects can have significant implications for nanomaterials with a high volume fraction of GBs or interfaces. Prior experimental studies16,17,18 and atomistic simulations10,11,17 revealed that nanomaterials generally show better radiation resistance in comparison with conventional coarse-grained materials. The underlying mechanism has been revealed by Bai, Uberuaga and coworkers10,19, demonstrating that interstitial-loaded GBs, acting as a source, can emit interstitials to annihilate vacancies present in the near-GB region.
A quantitative picture of defect segregation energetics is essential to the understanding of dynamic processes of defect evolution in materials under irradiation. On this very topic, density functional theory calculations20,21 and atomistic simulations9,10,11,22,23,24,25,26,27,28,29 have been frequently used to describe the segregation energetics of point defects (including impurities) to a series of GBs. For example, Tschopp, Solanki and coworkers have performed extensive atomistic simulations to investigate the effects of GB character on the formation energetics of point defects, such as vacancy9,22,23,24,30, self-interstitial9, hydrogen25,26, helium26,27, carbon26,28 and various other impurities23,26. Aiming to mitigate radiation damage, Uberuaga, Demkowicz and coworkers have conducted massive multiscale simulations19,31,32,33,34,35,36,37,38 to understand the effects of interface structure on point defect segregation, defect mobility, defect recombination and GB sink efficiency. Jiang et al.29 demonstrated that GB types can make a difference in determining the sink strength and radiation tolerance of GBs. Another important aspect of this phenomenon is that point defect segregation can lead to GB or interface structural transformation39,40,41,42, which further influences GB migration behavior43,44 and sink strength45.
Tungsten (W) is considered as a leading candidate for plasma-facing materials in future nuclear fusion reactors. The bombardment of high-energy neutrons generated in deuterium-tritium nuclear reaction can be devastating. Therefore, it is of great interest to investigate the point defect segregation energetics in bcc W. Though efforts46 have been made to understand this issue, complete data set regarding the influence of GB character on point defect segregation energetics is still lacking. Furthermore, the nature of GB vacancies along with its potential influence on GB migration, and the effect of different GB states, corresponding to each particular misorientation angle, on vacancy segregation have been unclear. The objective of this work is to gain further understanding on these key issues based on atomistic simulations using an embedded atom method (EAM) potential, and possibly provide inputs of energetics and vacancy absorption length scales for modelling and simulation of W at larger scales.
Grain boundary character described in terms of GB energy and structure has long been studied in bcc, fcc and hcp metals9,47,48,49,50,51. The 36  equilibrium symmetric tilt grain boundaries (STGBs) with misorientation angle θ varying between 5.5° and 84.5° have been previously explored in our most recent work regarding shear-coupled GB migration52. The extra energies of these equilibrium STGBs are presented in Supplementary Table 1. Typical GB structures which possess all the features of  GB family are illustrated in Fig. 1. Specifically, the lower end of the low-angle GBs (≤15°) classified as low angle-I present a discrete array of 〈100〉 dislocations, while the higher end of the low-angle GBs (≥75°) classified as low angle-II consist of an array of resolved 1/2 〈111〉 dislocations53. According to the previous dislocation models, these two kind of low-angle GBs can be satisfactorily described by the type 2 tilt wall model48,49 and type 1 tilt wall model48,49, respectively.
Figure 1: Grain boundary structures and local hydrostatic stress for selected  STGBs.
The labelled structural units are consistent with previous works on bcc iron9,22. Note that ∑5(01-3) and ∑5(01-2) are favored boundaries as they (contain the basic structural units B and C, respectively) along with the structural units of their variants and the units of the perfect lattice constitute the other high angle STGBs. The low-angle STGBs can be readily described by previously proposed dislocation models48,49. Different numbers of coincidence site lattice (CSL) periodicities are depicted to facilitate easy comparison. The range of −15 to 15 GPa is used for visual clarity. Here, the upper grain is taken as the reference lattice for all crystallographic indices with x being the  tilt axis and y the GB normal.
The structures of the high-angle STGBs can be readily characterized by the well-established structural unit model9,47,54, i.e., the STGBs can be determined by a combination of structural units from the favoured ∑5(01-3) (consists of B units) and ∑5(01-2) (consists of C units) boundaries, variant of the basic structural unit such as B′ and those from the perfect lattice A and A′, as shown in Fig. 1. For instance, ∑13(01-5) and ∑97(05-13) can be expressed as ∑13(01-5) = 2 A + 2B and ∑97(05-13) = 2B + 4B′ + 2 C, respectively. Another important feature of the STGBs is that they are not necessarily perfectly mirror-symmetric due to the in-plane translations, as clearly shown by the low-angle ∑145(08-9) or the high-angle ∑5(01-2) GBs. This kind of broken symmetry has also been found in several previous literatures55,56. Regarding the stress fields of the GBs, it has been recognized that GBs do not produce long-range stress fields. Figure 1 shows that the local hydrostatic stress concentrates in the GB region and its site to site values can vary drastically from −30 to 30 GPa for all the  STGBs studied here, which is important in determining the vacancy segregation energetics.
The variations of segregation energy in the vicinity of GBs have been quantified by plotting the correlation between vacancy segregation energy and the distance from the GB, which can be further complemented by drawing the spatial distribution map of the segregation energetics. Figure 2 shows the vacancy segregation energy as a function of distance for the STGBs depicted in Fig. 1. The dependence of vacancy segregation energy on spatial positions is shown in Fig. 3. The segregation energy is closely related to the vacancy sites with respect to GB dislocation cores or structural units. A comparison between Figs 1 and 3a suggests that the strongest vacancy attraction tends to occur at the compressive region. Quantitatively, the minimum segregation energies for these GBs vary significantly from −2.61 to −0.76 eV depending on the GB character. Note that slight repulsion of no more than 0.25 eV between the vacancy and the GB (see Fig. 3b) has been found in all the GBs, indicating that there are some unfavourable GB sites for vacancy segregation. This is consistent with recent atomistic simulations9 of vacancy-GB interaction in bcc iron using an EAM potential.
Figure 2: Vacancy segregation energy as a function of distance from the selected GBs corresponding to Fig. 1.
The blue dashed box is defined as the GB absorption region where there are sites having segregation energies of −0.12 eV or lower at any distance within this region. The reference vacancy formation energy in a perfect bulk lattice is 3.631 eV.
Figure 3: Vacancy segregation energy as a function of spatial position projected onto the (100) plane.
(a) Attractive sites; (b) repulsive sites. Noticeably, values of vacancy repulsion are about an order of magnitude lower than those of vacancy attraction.
To provide further insight, we plot in Fig. 4a the vacancy segregation energy as a function of distance from the GB for all the STGBs. It can be seen that there exists a correlation between GB type and vacancy absorption length scale. Low angle-II STGBs show distinctively larger absorption length than high-angle STGBs, whereas low angle-I STGBs have slightly larger absorption length scale than most of the high-angle STGBs, as also demonstrated in Supplementary Table 1. The mean segregation energy is commonly used to characterize GB sink strength9,22. Figure 4b shows the mean vacancy segregation energy as a function of distance from the GB. A striking feature is the remarkable deviations from the mean values as the vacancy approaches the GB plane, indicating the significant segregation energy site to site variations influenced by the complex local structural compositions and stress environment. The fact that the plot is slight off-symmetry confirms the broken mirror-symmetry for several STGBs illustrated above. Another interesting point is that the vacancies locating right at the GB plane, in many circumstances (see ∑145(01-17) and ∑13(01-5) in Fig. 3), are less energetically favourable than vacancy sites one atomic layer from the GB interface, consistent with prior works9,22.
(a) Vacancy segregation energy and (b) mean vacancy segregation energy as a function of distance from the GB for all the  STGBs. For (b), vacancy segregation energies for sites in each 1 Ǻ bin on both sides of the STGBs are averaged. The error bars present the standard deviation from the mean values.
It is worth noting that vacancy delocalization has been commonly observed in most of the GBs, corresponding, in most cases, to sites having low segregation energies. The definition of "vacancy delocalization" is that the creation of the vacancy leads to marked relaxation further than the nearest neighbours38,46,57,58,59. This phenomenon is closely associated with the GB dislocation cores where the local compressive stress is the strongest. Structural visualization shows that, in low-angle GBs, vacancies in the bulk-like region between the dislocation cores remain compact, while they tend to delocalize as they approach the compressive side of the core. Since GB dislocation cores overlap in high-angle GBs, we observe, as expected, a high density of vacancy sites being delocalized. Figure 5 presents the vacancy segregation energetics of four neighboring GBs with similar character. By comparing Fig. 5a,c (with vacancy delocalization) with Fig. 5b,d (without vacancy delocalization), we show that vacancy delocalization leads to distinctively lower segregation energies, as can be seen from the large segregation energy gaps. It is sometimes, however, difficult to distinguish and quantify the boundaries between vacancies being delocalized and those that are not. The incompact nature of the vacancy structure can be important in several aspects. Kinetically, the migration mechanisms of the delocalized vacancy are dislocation-based, involving the nucleation of thermal kink pairs and multiple metastable states38,57. Since these states are separated by small barriers, the migration of delocalized vacancies is much easier than conventional vacancy migration with a single large activation energy barrier. This effect may have dramatic implications for GB mobility due to that the mobility of GBs have been revealed to be often dictated by the mobility of GB defects and impurities33,60. Our preliminary results show that well-defined vacancies inhibit GB migration (Supplementary Fig. S1) at low temperatures due to their lower mobility while delocalized vacancies facilitate GB migration (Supplementary Fig. S2).
Vacancy segregation energy as a function of distance from (a) ∑37(05-7), (b) ∑25(03-4), (c) ∑65(07-9), and (d) ∑41(04-5) neighboring GBs. The blue dashed box is defined as the GB absorption region where there are sites having segregation energies of −0.12 eV or lower at any distance within this region. The insets are the corresponding GB structures colored according to their potential energies. Vacancies created in (a,c) remain compact, while delocalized vacancies are found in (b and d), which is reflected by the much lower minimum vacancy segregation energies. The reference vacancy formation energy in a perfect bulk lattice is 3.631 eV.
The energetics of vacancy segregation is determined by the local coordination environment and the corresponding local stress fields. In this section, we will probe how local stress and GB energy influence the evolution of vacancy segregation energetics, and whether correlations between them can be established. Figure 6 shows the vacancy segregation energy as a function of the local hydrostatic stress for all the  STGBs. The effect of six independent local stress components on vacancy segregation is shown in Supplementary Fig. S3. Note that a quantitative description of vacancy-GB interaction using elasticity theory is not feasible, especially for high-angle GBs, due to the short-range stress field of the GBs. However, a qualitative interpretation can be given. According to elasticity theory, the vacancy-GB interaction comes from two main terms, i.e., the first-order size effect61,62 and the second-order inhomogeneity effect61,62. The first term only involves the hydrostatic field of the GB and vacancy relaxation volume, whereas the second term originates from the fact that vacancy having different elastic constants from the matrix will bring an inhomogeneity interaction, which comprises contributions from the hydrostatic and deviatoric parts of the stress tensor. The effective elastic constants of vacancy is essentially zero, hence this term only induces attraction. If we only consider the first-order size effect, the vacancy-GB interaction will be increasingly repulsive with increasing tensile stress, which completely deviates from the atomistic results here. Therefore, while the first-order size effect dominates the compressive region, the second-order inhomogeneity interaction term should be dominant at the tensile region possibly due to the small vacancy relaxation volume at this region.
Figure 6: Dependence of vacancy segregation energy on local hydrostatic stress for all the  STGBs.
The dashed lines are guide for the eyes. The first-order size effect and the second-order inhomogeneity effect dominate at the compressive and tensile region respectively.
Figure 7a shows the minimum vacancy segregation energy as a function of GB energy for all the  STGBs. The linear correlation coefficient has been used to quantify the magnitude of linear correlation. Here, values of −1 and 1 represent perfect negative and positive linear correlations, respectively. For the low-angle GBs, low angle-I and low angle-II GBs distribute at separate sides of the fitting line with an energy gap of ~0.5 eV, and the linear correlation coefficient of 0.14 indicates that the minimum segregation energy is, to a great extent, independent of the GB energy. In contrast, both the lowest value of −0.76 eV and the highest value of −2.61 eV are found in the high-angle GB category. The obtained linear correlation coefficient of −0.38 indicates a weak negative correlation. We further show in Fig. 7b the dependence of mean vacancy segregation energy (ranges from −0.44 to −1.01 eV) and absorption length scale (ranges from 3.18 to 12.41 Å) on GB energy for all STGBs. The corresponding linear correlation coefficients of −0.75 and −0.70 suggest reasonably strong negative correlations. Specifically, increasing GB energy, which involves a transition from the low-angle GBs to the high-angle ones, generally enhance vacancy segregation to the GBs, and, on the other hand, decreases the vacancy absorption length scale.
Dependence of (a) minimum vacancy segregation energy and (b) mean vacancy segregation energy and absorption length scale on GB energy for all the  STGBs. For (a), the linear correlation coefficients for the low- and high-angle GBs are 0.14 and −0.38, respectively. For (b), the linear correlation coefficients for the mean segregation energy and absorption length scale were calculated as −0.75 and −0.70, respectively, suggesting they are highly negatively correlated with the GB energy. Note that the vacancy length scale is defined as half of the values defined in Fig. 2. When calculating the mean segregation energy, only vacancies having segregation energies of −0.12 eV or lower are included.
The understanding of GB equilibrium states is, undoubtedly, essential to the construction of the relationship between the GB structure and properties. Nevertheless, GBs in polycrystalline materials are more often found at nonequilibrium states under many circumstances, such as plastic deformation and radiation damage, and their multiplicity has been demonstrated by a wide range of experimental63,64,65,66,67 and computational studies39,40,66,68,69,70,71. In this section, we illustrate the effect of GB metastability on vacancy segregation energetics using four states of a typical long-period ∑89(03-13) GB.
We plot in Fig. 8, similar to Fig. 2, the vacancy segregation energy as a function of distance for one equilibrium (most stable, denoted as 'S') and three nonequilibrium (metastable, denoted as 'MS') STGBs. With increasing GB energies from 1961.9, 1975.5, 1981.6 to 2026.9 mJ/m2, we obtain correspondingly decreasing minimum segregation energies from −2.42, −2.72, −2.77 to −2.88 eV, and decreasing mean segregation energies from −0.76, −0.83, −0.88 to −0.93 eV. The vacancy absorption length scales have also been slightly decreased. The specific correlations are shown in Supplementary Fig. S4. These results support the negative correlations we established in Fig. 7 using equilibrium GBs of different misorientation angles.
Vacancy segregation energy as a function of distance from the selected ∑89(03-13) GB states corresponding to (a) the most stable (denoted as 'S') and three metastable states (b) 'MS1', (c) 'MS2', and (d) 'MS3'. The corresponding GB energies are given in the brackets at the lower right corner. The blue dashed box is defined as the GB absorption region where there are sites having segregation energies of −0.12 eV or lower at any distance within this region. The reference vacancy formation energy in a perfect bulk lattice is 3.631 eV.
The corresponding vacancy segregation maps are depicted in Fig. 9 (the repulsive sites are shown in Supplementary Fig. S5). As we have discussed in the first section of "Results", the four GB states can also be presented as different combinations of basic GB structural units A, B, and B′: S = 4 A + 4B + 2B′ = |B′BABA.B′BABA|, MS1 = 4 A + 3B + 3B′ = |B′BAB′BA.BAB′A|, MS2 = 4 A + 5B + B′ = |B′BABA.BBABA|, and MS3 = 4 A + 6B = |BBABA.BBABA|. Interestingly, the GB states S, MS2 and MS3 follow a similar trend in terms of the arrangement of B (B′) and A. The GB energies can be continuously lowered from MS3, MS2 to S as B units are turned into B′. However, when we replace another B unit in S state to B′, shifting the GB to another metastable state MS4 = 4 A + 3B + 3B′ = |B′BAB′A.B′BABA|, the GB energy increases to 1978.6 mJ/m2, larger in energy than MS1 despite that they have the same combination of structural units. This indicates that GB energy is affected by both the combination and the permutation of GB structural units. At each GB state, neighboring vacancy sites having similar deep colour are found to be delocalized. Removing any one of them yields the same final defect structure, as can also be reflected by Fig. 8, in which sites of different distances from the GB plane have exactly the same level of segregation energies. The distinct feature in Supplementary Fig. S5 is that repulsive sites are only found a few atomic layers from the GB plane in state MS3, which is free of B′ unit, similar to those of ∑13(01-5) and ∑5(01-3) GBs presented in Fig. 3b.
Figure 9: Vacancy segregation energy as a function of spatial position projected onto the (100) plane for ∑89(03-13) of different GB states (see the caption of Fig. 8 for more details).
Only attractive sites are shown. These GB states can be, as we have demonstrated in the first section of "Results", presented as different combinations of basic structural units A, B, and B′.
In this section, the implications of this study will be presented. We have, unfortunately, not found any experimental studies on  W bicrystals regarding their energy and structure, comparisons will thus only be made against existing ab initio and atomistic simulation results. It is well documented that ab initio methods can describe elemental properties and interactions more accurately in comparison with classical atomistic simulations and one of the fundamental issues of the classical atomistic simulations is whether the interatomic potentials used is reliable and trustworthy72. Prior ab initio study by Mrovec et al.73 reported the GB energy of ∑5(01-2) as 2781 mJ/m2, and those of ∑5(01-3) as 2335 mJ/m2 and 2235 mJ/m2 for the mirror-symmetric and the displaced structures, respectively. The present EAM potential yields GB energies for the equilibrium states of ∑5(01-2) and ∑5(01-3) as 2000 mJ/m2 and 1796 mJ/m2, underestimating the GB energies by 781 mJ/m2 and 239 mJ/m2, respectively.
However, since GB structures have been frequently found to be with a broken mirror-symmetry and different GB site densities by both experimental63,64,65,66,67 and computational39,40,66,68,69,70,71 studies, it is important to recognize that the ab initio studies might also overestimate the GB energies due to their inherent inefficiency in thoroughly searching the GB phase space for the equilibrium states as that did by the classical simulations, in which thousands of GB in-plane displacements, atom eliminations, and sometimes high-temperature annealing are implemented45,55,56. Moreover, the high computational cost of ab initio calculations confines its usage to short-period GBs, which makes the comparison of the entire picture of GB structure (energy) versus misorientation angle unfeasible. Notably, the qualitative correlation between GB energy and misorientation angle (see Supplementary Fig. S6) agrees well with atomistic simulations of  STGBs in bcc iron9, tantalum51 and molybdenum74.
Regarding vacancy formation, the obtained bulk vacancy formation energy of 3.631 eV (see Supplementary Fig. S7) is in good agreement with experimental and ab initio values75. The ab initio calculations in our group recently obtained a minimum vacancy segregation energy of −1.53 eV for ∑5(01-3) GB, which doubles that (−0.76 eV) in the present work. However, the fact that a higher energy mirror-symmetric GB state, instead of the equilibrium displaced state, was used in the ab initio study support our conclusion in the previous section "Effect of GB metastability on vacancy segregation energetics": GB states of higher energies lower the vacancy segregation energies. Quantitatively speaking, a GB energy increase of 13.6 mJ/m2 from S to MS1 state lowers the minimum vacancy segregation energy by 0.30 eV (Fig. 8 and Supplementary Fig. S4). We thus expect much larger decrease of vacancy segregation energy considering the energy difference73 of 100 mJ/m2 between the equilibrium displaced state and metastable mirror-symmetric GB state of ∑5(01-3) GB.
The bulk vacancy formation energy of 3.631 eV also indicates that the vacancy formation energies in all the equilibrium and metastable GB states considered in this work are positive, which evidences that the GBs we adopted are at low-energy states. It is, nonetheless, debatable whether researchers should pay primary attention to obtaining the equilibrium GB states considering the widespread presence of metastable GB states in polycrystalline materials. Equal emphasis should, at least, be placed on GB properties of metastable states. Zero or even negative vacancy formation energies are very likely to be observed under continuous vacancy loading according to the recent atomistic simulations conducted by Yu and Demkowicz45. They also stated that higher-energy GBs which have lower vacancy segregation energies are likely to be stronger vacancy sinks than lower-energy ones. In that sense, the high-angle GBs studies here might also have higher sink efficiencies than their low-angle counterparts. However, this hypothesis is also up for debate, since Jiang et al.29 demonstrated the contrary results that the larger stress fields of low-angle GBs lead to them having higher sink strength than high-angle GBs, which, in our case, is shown by the larger vacancy absorption length scales of low-angle GBs. Most recently, A. Vattre et al.34 also demonstrated the strong effect of the elastic stress fields in enhancing interface sink strength. More comprehensive models taking into account these important factors are called for to describe the complex defect evolution in materials upon irradiation.
In terms of the GB vacancy structures, our observation46 of possible vacancy delocalization in the dislocation core of the most GBs is consistent with the dislocation-based mechanism demonstrated by Yu and Demkowicz45, and the transmission electron microscopy observations by King and Smith76. We, however, have not detected such feature in some GBs such as ∑37(05-7) and ∑65(07-9) GBs, which have distinctively higher minimum vacancy segregation energies than its neighbours (see Fig. 5). However, it is reasonable to believe that the compact vacancies near the core are likely to delocalize at finite temperatures. A good test of the nature of the GB vacancies is to perform GB migration simulations (see Supplementary Figs S1 and S2 and the corresponding Supplementary Notes) at low temperatures and examine whether the GB vacancies can follow the migration of GBs. Since vacancies with compact nature are immobile at this temperature, they will inhibit GB migration and eventually be left behind by the migrating GBs. It is, nonetheless, still unclear to what extent will the materials be influenced by the compact vacancies. As we have demonstrated previously46, vacancies are both energetically and kinetically favourable to be absorbed by the GB dislocation cores and become delocalized. Therefore, vacancy delocalization might be an intrinsic feature in GBs.
It is currently well-accepted that equilibrium GBs can switch to different metastable states upon defect loading and absorption33,39,45 and the resulting metastable states can become better defect sinks10,45. In fact, the GB states can switch periodically upon continuous defect loading33,45, consistent with GBs being unsaturable or inexhaustible defect sinks. These observations also justify the self-healing mechanism proposed by Bai et al.10 that both interstitial emission and vacancy absorption can be activated at different temperature windows. Future works are underway to explore the influence of different GB character and states on the segregation energetics of impurities such as hydrogen and helium in bcc W. The obtained energetics and defect absorption length scales will provide useful inputs to the modelling and simulation of defect evolution and absorption at experimental time scales. For example, a rate-theory model on GB sink strength requires point defect formation energetics, absorption length scales, or defect migration barriers that can be readily obtained by atomistic simulations29,34. This will contribute to addressing the lifetime issue confronting the W-based plasma-facing components in future nuclear fusion devices.
We have carried out molecular statics simulations to explore the energy landscapes of vacancy segregation to a range of equilibrium and metastable  symmetric tilt grain boundaries (STGBs) in bcc tungsten (W). The following conclusions can be drawn from this study.
For the equilibrium GBs, the magnitudes of minimum vacancy segregation energies vary from −2.61 to −0.76 eV, while those of mean vacancy segregation and absorption length scales range from −1.01 to −0.44 eV and from 3.18 to 12.41 Å, respectively, depending on the GB character.
Low-angle GBs have larger absorption length scales over their high-angle counterparts and the most energetically favourable vacancy sites are more often found at the first layer from the GB interface, while the repulsive sites are found in all GBs.
A qualitative analysis based on elasticity theory suggests that the first-order size effect and the second-order inhomogeneity effect dominate at the compressive and tensile region respectively.
There exist highly negative linear correlations between GB energy and mean vacancy segregation energy/vacancy absorption length scale for the equilibrium GBs.
The negative correlation between GB energy and mean vacancy segregation energy are applicable to GB metastable states as well. We further show that GB energy is affected by both the combination and the permutation of GB structural units.
The dislocation-based (delocalized) vacancy structure, which has been observed in many of the  STGBs studied here, may be an intrinsic feature of GBs, and it is of great significance in facilitating GB migration.
This study reveals the important effect of different GB character and states on vacancy segregation behavior and provides useful inputs for large-scale models, contributing to the possible application of polycrystalline W under irradiation in advanced nuclear fusion reactors.
where EGB and E0 represent the total energies of the supercell with and without a GB, respectively. A denotes the area of the GB interface. Since three-dimensional periodic boundary conditions were used, reasonably large cells (see Supplementary Table S1) were used to make sure that the interaction of the GBs and vacancies with their periodic images can be neglected. Tests on the possible size effect are presented in the Supplementary Fig. S7. The open software Ovito is used for structural visualization80.
where and denote the vacancy formation energy in a perfect bcc bulk lattice and in a crystal with a GB, respectively. Thus, a negative segregation energy indicates attraction between the vacancy and the GB. Note that the local stress components were calculated using the viral stress tensor expression implemented in LAMMPS divided by the per-atom Voronoi volume.
How to cite this article: Chen, N. et al. Energetics of vacancy segregation to  symmetric tilt grain boundaries in bcc tungsten. Sci. Rep. 6, 36955; doi: 10.1038/srep36955 (2016).
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This work is supported by the National Natural Science Foundation of China (NSFC) through Grant No. 51671009, 51371019 and 11405006. G.H.Lu acknowledges support from China National Funds for Distinguished Young Scientists through Grant No. 51325103. Guang Ran is supported by the National Natural Science Foundation of China (NSFC) through Grant No. 11305136. Ying Zhang acknowledges the Beijing Key Discipline Foundation of Condensed Matter Physics for its support. Liang-Liang Niu thanks the China Scholarship Council for supporting his study at University of Michigan.
N.C. and L.L.N. contributed equally to this work. N.C. and L.L.N. performed the calculations and wrote the manuscript under the supervision of G.R., Y.Z. and X.S. The collaboration is coordinated by G.R., G.H.L. and F.G. H.B.Z. and S.J. contributed to the scientific discussion of the results. All authors reviewed the manuscript.
Correspondence to Ying Zhang or Guang Ran or Fei Gao.


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Home> Explore NIHR> Specialties> Primary Care
NIHR School for Primary Care Research
We fund primary care research projects through our funding programmes, and support training and career development for primary care researchers.
We deliver primary care research funded by the NIHR, the life sciences industry and non-commercial organisations such as charities. We support the set up and delivery of this research in the NHS and in public health and social care settings. Our research infrastructure also supports primary care research funded by these partners, offering expertise, collaborations and facilities.
We also provide opportunities for patients and their families and carers to influence and take part in primary care research.
The NIHR supports patients and the public to participate in high quality research taking place in health and care settings across England, advancing knowledge and improving care.
NIHR Clinical Research Network
The NIHR Clinical Research Network (CRN) includes 30 specialty groups, who coordinate and support the delivery of high quality research by therapy area. Some of this research is funded by the NIHR, but most of it is funded by non-commercial organisations, such as charities or universities, and the life sciences industry.
The CRN provides researchers with the practical support they need to make research happen. It supports the set up and delivery of clinical research in the NHS and in other health and care settings through our Study Support Service, with tailored offers of support for:
non-commercial organisations
the life sciences industry.
Supporting primary care research
The CRN Primary Care Specialty Group works with researchers and primary care practitioners such as GPs, practice nurses, pharmacists and dentists to promote the successful delivery of research studies in the NHS. We support a wide range of research, including studies that look at:
Disease diagnosis and prevention
Management of long-term illnesses such as diabetes or hypertension
Prevention of future ill-health
Treating common conditions such as tonsillitis or influenza
Where there are considerable overlaps with other specialty areas, for example diabetes, mental health and cardiovascular disease, we work closely with our colleagues from across the CRN to deliver high quality research in a primary care setting.
The Primary Care Specialty has a proven track record of successful recruitment across all manner of conditions and complex interventions. In 2019/20, over 150,000 participants were recruited into 430 studies, with 97 per cent of studies recruiting to time and target.
One of the major issues facing primary care professionals engaging with research was, until recently, the lack of clarity around indemnity for medical negligence in undertaking research. This is now provided by CNSGP within the remit of NHS Resolution, you can find out more on their website.
As well as providing research delivery staff, we also bring together highly engaged NHS consultants and clinical academics from top UK universities, bringing both clinical and academic expertise to your research. Our experts in the CRN Specialty Group can advise on delivering your infection study in the NHS and in particular geographic regions.
Professor Philip Evans is the CRN National Specialty Lead for primary care. Read Associate Professor Evans's full biography.
Professor Philip Evans is supported by local specialty leads in each of the 15 NIHR Local Clinical Research Networks.
Our collaborators and stakeholders
The Clinical Research Network (CRN) Primary Care specialty has developed close links with key stakeholders and clinical researchers to input into the delivery of studies and influence the primary care research agenda.
We have established a longstanding partnership with the Royal College of General Practitioners (RCGP) and support them on a number of initiatives, such as:
The RCGP Awards which recognise outstanding contributions of NHS general practices and First5® GPs who are active in research.
Research Ready® for general practices, relaunched in 2021, was developed by the Royal College of General Practitioners and the Clinical Research Network to support practices to carry out high quality research. This quality framework helps practices to develop a research culture and ethos.
Working with the Royal Pharmaceutical Society, the NIHR have developed Research Ready® for pharmacies to support pharmacies to carry out high quality research. This quality framework helps pharmacies to develop a research culture and ethos.
Clinical Practice Research Datalink
The Clinical Practice Research Datalink (CPRD) provides access to high quality, anonymised primary care data for retrospective and prospective research studies, such as outcomes research, epidemiology and randomised controlled trials.
The primary care data are linked to a range of other health related data to provide a longitudinal, representative UK population health dataset.
CPRD data and services can be highly tailored to meet specific research needs.
Find out more about using CPRD data
Our funding programmes fund high quality research in primary care that benefits the NHS, public health and social care. We also provide career development funding awards for primary care researchers - see the careers tab for more information.
Our funding programmes
Most of our funding programmes run funding calls open to research proposals on any topic (researcher-led calls), including research proposals in primary care.
Find funding opportunities in primary care
We have previously held a themed call on primary care interventions (2013). NIHR themed calls are funding opportunities focusing on a particular research topic, in which all our funding programmes participate.
Have an idea for research in primary care? The NIHR Research Design Service can help you turn it into a funding application, offering advice on research design, research methods, identifying funding sources, and involving patients and the public.
Find out more about the NIHR Research Design Service
Our portfolio of primary care research
You can search and view all the primary care research we've funded on NIHR Funding and Awards.
In addition, a number of our research programmes publish comprehensive accounts of our primary care research in the NIHR Journals Library.
Our research schools
The NIHR School for Primary Care Research (SPCR) is a partnership between nine leading academic centres for primary care research in England.
SPCR aims to increase the evidence base for primary care practice through high quality research and strategic leadership, and to build capacity in primary care with a well established training programme.
The NIHR attracts, trains and supports the best researchers in primary care to tackle the complex health and care challenges of the future.
Our investment in people sustains excellent research capacity and expertise throughout clinical and non-clinical academic career pathways and provides high quality learning and development opportunities for the delivery workforce in our infrastructure.
Funding research careers
The NIHR Academy is responsible for the development and coordination of NIHR academic training, career development and research capacity development.
There is a wide range of NIHR training and career development awards available at different career stages, from pre-doctoral through to Research Professorships. These awards comprise both personal awards, which can be applied for directly with the NIHR, and institutional awards which should be applied for through the host institution.
Find out more about our training programmes
Supporting the delivery workforce
Associate Principal Investigator Scheme for PRINCIPLE Study
The Associate Principal Investigator (PI) Scheme aims to develop junior doctors, nurses and allied health professionals to become the PIs of the future and provides formal recognition of a trainee's engagement in NIHR Portfolio research studies.
The NIHR Associate Principal Investigator (API) scheme in primary care, linked to the PRINCIPLE platform study of COVID-19 treatment in the community, was launched on 19 May 2021. It is designed to encourage doctors and other health professionals in a general practice site to recruit into the study and gain NIHR accreditation and experience of research in practice.
Find out more about the API Scheme for PRINCIPLE
Find out about our career development support for healthcare professionals
The NIHR invests significantly in people, centres of excellence, collaborations, services and facilities to support health and care research in England. Collectively these form the world-class NIHR infrastructure.
This national research infrastructure is available to use by UKRI, research charities and the life sciences industry as well as NIHR researchers.
Find out more about working with our research infrastructure as a researcher or a member of the life sciences industry
NIHR Applied Research Collaborations
NIHR Applied Research Collaborations (ARCs) support applied health and care research that responds to, and meets, the needs of local populations and local health and care systems.
The following ARC undertakes research in primary care:
NIHR Applied Research Collaboration Kent, Surrey and Sussex
NIHR Medtech and In vitro diagnostics Co-operatives
NIHR Medtech and In vitro diagnostics Co-operatives (MICs) build expertise and capacity in the NHS to develop new medical technologies and provide evidence on commercially-supplied in vitro diagnostic tests.
The following MIC undertakes research in primary care:
NIHR Community Healthcare MedTech and In Vitro Diagnostics Co-operative
The NIHR Clinical Research Network (CRN) supports set up and delivery of clinical research in the NHS and in other health and care settings. Find out more on the delivery tab.
The NIHR funds and supports world-class experts in primary care.
Find out more about collaborating with our experts
In addition, our experts in the NIHR Clinical Research Network (National Specialty Leads) can advise on delivering your primary care study in the NHS or in other health and social care settings.
Get our expert advice on delivering your research
National Specialty Lead
Associate Professor Philip Evans is the CRN National Specialty Lead for Primary Care. He is an academic GP and Associate Professor in the University of Exeter Medical School. He has a research interest in continuity of care, management of pre-diabetes and also the prevention and diagnosis of type 2 diabetes in primary care.
Director of the NIHR School for Primary Care Research
Professor Christian Mallen is the National Director of the NIHR School for Primary Care Research. He is the Head of the School of Medicine at Keele University, and an NIHR Research Professor in General Practice.
Read Professor Mallen's full biography
We engage with and involve patients, carers, service users and members of the public in order to improve the reach, quality and impact of research in primary care.
Have your say in research
We involve patients, carers, service users and members of the public in our national research funding and support activities, including in primary care research.
Find out more about getting involved in our national funding and support activities
The researchers we fund also involve patients in planning and delivering their primary care research.
Find out how to get involved in NIHR-funded research in your local area
Our Local Clinical Research Networks involve people in primary care research taking place in your local area.
Find your Local Clinical Research Network to see how you can get involved
Involvement opportunities across the NIHR
The NIHR Community Healthcare MedTech and In vitro diagnostics Co-operative works with members of the public across all of its themes and at all levels, helping to ensure that their research is grounded in issues that matter to patients and society.
Find out more about getting involved with their research
The NIHR School for Primary Care Research, which aims to gather evidence to help decide what will make primary care better for everyone, is committed to meaningful patient and public involvement and public engagement.
Find out more about getting involved with the School for Primary Care Research
Be Part of Research is an online service that lists opportunities to take part in primary care research across the UK.
Refreshed NIHR School for Primary Care Research to strengthen whole primary care research sector
The NIHR has announced the fourth phase of the School for Primary Care Research (SPCR), with a refreshed membership and a new focus on supporting the full spectrum of primary care research and building research capacity.
Read more about the new SPCR
Public health and prevention
Latest news about Primary Care
News: World-leading study to pitch human skill against robot for knee surgery
News: Better treatment for miscarriage patients is more cost effective than current standard NHS treatment, study finds
News: Asthma drug shortens recovery time in non-hospitalised patients with COVID-19
Latest blogs about Primary Care
Blog: Research: Ability to change practice, improve care and learn more
Blog: Creating conversations: Connecting life science companies and patients to improve research
Blog: #Covid19ResearchVoices: Research has never been so important
Latest case studies about Primary Care
Case study: Improving flu vaccination rates in general practice
Case study: Preventing falls in the over 65s
Case study: VOICE training for healthcare professionals aids communication with dementia patients
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redpajama_set_name: RedPajamaCommonCrawl


This weekend's Rants addresses a subject on which I am experienced as a man, husband, and a father. That said, I am still learning.
Maybe I and all of us need to stop for a moment and consider the lesson taught to a young grandson by an Elder Cherokee Grandfather? Do you know it?
I wish I could tell you that at 65-years young I have it pretty much all figured out. The truth is that I do not, and I am not always a "good guy." I am often obtuse, prideful, too quick to anger, I fail and disappoint. The truth is, I am in desperate need of God's Grace and forgiveness at least once or twice an hour.
You see, I struggle more often than I would prefer to choose what I know to be the emotionally and spiritually healthier choice. Perhaps you do too?
Come on, I know you know it deep down inside… but when is the last time you said it out loud so others would hear you? When the battle is ragging under the stresses of the day, are you deciding you need to feed the right wolf?
Never has it been more evident with the current news cycle of sexual violence in Hollywood and the halls of power that, as a gender, we are guilty of some appalling and soul-destroying behavior. Yes, I know you, and I are not Harvey Weinstein. We don't likely commit that kind of violence.
But if certain Hollywood "A-Listers" are guilty of turning a blind eye to protect their borrowed power, how many times have you or I done the same thing perhaps? Let's not split hairs.
How often are we guilty of the sin of omission (not commission) when we are with friends, at the office or simply by ourselves? And how many of us are willing to confront and confess our weakness and temptation?
Like the old Cherokee Grandfather, perhaps we often feed the wrong wolf?
In the early 90's a heavy metal Christian rock band took the national music scene by storm. Stryper (whose name was taken from Isaiah 53:5 "by his stripes, we are healed") was all the rage with youth groups and now older 60-somethings like me who to this day love our prog rock. They also severely disrupted a good many church "elders" as they used heavy metal music to share the Gospel of forgiveness and redemption.
WATCH HERE: Annie Lobert (wife of Stryper's Oz Fox) tells her story of the "Little girl lost." Failed and abused by the men in her life, she prostituted herself and became addicted… as much to the desire for revenge as to the cocaine.
Annie is no longer lost and addicted to her power. Annie is a redemption story gone full circle. In Grace, she stopped feeding the dark wolf that had nearly destroyed her. Today she runs Hookers for Jesus – saved, unbowed and making a difference on the streets of Los Angeles. Yes, it is an extreme story… but perhaps not as much as you might think.
A Gold Star Dad whose Fallen Hero son was killed in Iraq in 2005. He too must decide every day which wolf he will feed. His name is George… Gold Star Dad, George Lutz.
Suddenly and forever, George's son, Cpl. George "Tony" A. Lutz II was a Fallen Hero in The War on Terror. God-in-Heaven, what do you do with the loss and the pain? I can't imagine it. Can you?
In the midst of his grief and pain, George chose which wolf he would feed. No less grief-stricken, he took action.
The result of that choice now flies over my house, 21 State Houses all across the country… and maybe over your house. George's gift to us all is The Honor and Remember flag which has become the national symbol of recognition of all those, who when called upon have made the supreme sacrifice.
Heart, soul, and action. That's George's way. It's our way. Men and women are choosing to try to feed the right wolf… not always perfectly but doing our best every day.
WATCH HERE: My friend, George has a very personal message to share with you today. Take a few moments to be encouraged and motivated by this humble yet powerful man and his mission to Honor and Remember.
PreviousRich's Rants – Men. I Am One. Now For An "Out Loud" Conversation With Brothers and Sons.


Hello, I am looking at purchasing a biax and have been told that is a type 10e. The seller doesnt seem to know much about it and I cannot find any information on the web about this model?
The other information on the plate reads 110v, 220w, and 1200/s .
Does anyone know anything abou tthis model? Is this a flaker or a scraper?
If it's a BL-10 it is a light duty scraper model. If it's a HM-10, it is a flaker. Can't do any scraping with it.
But, painted blue, indicates the much older models of the Biax scrapers that are no longer made or supported for parts. But again the "10" in the model number would still indicate a light duty scraper or flaker.
Can you post a couple of pictures to give us a clue of what you have there?
here it is. Its a biax 10/e scraper. Over on PM richard says its an 80s model light duty scraper. Its basically immaculate. The powder coat or whatever it is on the front end isnt even chipped.
400 dollars out the door. I think it was a fair deal.
........400 dollars out the door. I think it was a fair deal.
Not bad, good deal in fact.
I only gave $150 for my 7EL that I bought used about 18 years ago. It was used very little, too!
It was a suprising deal. It popped up as a craigslist ad at a local pawn shop.
I bought mine from a pawn shop, too!
A pawn shop?!! I never would have thought of that showing up there. I'm going to start keeping my eyes open.
I have 2 of the 10E power scrapers....and I love then......great for light duty work.....you can pick a nice close bearing... then finnish by hand..
DAPRA is the distributer in the U.S. Their Web Site is: Dapra.com A definite steal, great find!
Check the date on the top. 2015.....what a deal. Oh I am a DAPRA distributor plus I am the USA Instructor that DAPRA calls on to teach classes on the BIAX tools. Also teach classes in Europe for BIAX the factory. I'll be teaching in Austria in November and have a class scheduled in OHIO next month, a class in Oklahoma in October. I taught 3 classes in CA last spring and if anyone has questions on machine rebuilding or the scrapers, please ask.
I will be at the IMTS show spending some time at the DAPRA booth in September.


Altogether, it was an inviting and intimidating bit of madness from executive chef Oliver Ridgeway, whose skill, creativity and passion have made Grange one of the very best restaurants in the Sacramento region. I said as much in my recent review. Since then, I have visited three of Grange's most direct competitors – and came away thinking Grange is operating at another level. Watch for a Q&A in with Ridgeway by Chris Macias in Sunday's Feast section.
But I digress. Burgers at upscale restaurants are both a chance to have a little fun and show off. That's what's going on here – times ten. One bite into this Bacon Fest special burger and I knew it was special. The flavors are so deep and exciting and the mouthfeel is incredible. That thick bacon is so tender it practically dissolves on your tongue, and it coats your mouth as you bite into the beef.
The patty itself is ground with an infusion of bacon, which brings an extra wallop of flavor and, with notes of smoke and salt, makes the beef taste like super beef. Cooked medium-rare, it is pink-red in the center. Served with house-made pickels, grilled onions, light-as-air bacon aioli, a bacon-salted bun, and cheddar cheese – along with an order of those excellent french fries – this burger was a tremendous eating experience.
I'm making a point to tell you all this because this is a limited-run burger. You have to act fast. Although Bacon Fest officially wraps up Sunday, I'm told this burger is coming off the menu after 2 p.m. today. I would urge Ridgeway and Grange to keep it around. If they don't, someone should launch a "save this burger" petition drive.
In this job, I have eaten a lot of great burgers, at upscale restaurants and dives alike, but as I wrack my brain and recall the burgers at Juno's, Formoli's, The Waterboy, Mulvaney's, the Flaming Grill, Broderick, Capital Dime, Pangaea and many others, I cannot think of a hamburger that was this delicious, this balanced and this bold.
Is this the best burger I've ever had? Right now, I'd have to say yes.
A bacon-salted bun, bacon so thick you'll think you're looking at pork belly, cheddar, a patty with bacon ground into it — this burger sounds way over the top but is actually balanced and delicious, albeit very bold and extra big.


In one of the many ironies of history, President Barack Obama, who left Iraq back in 2011 to fulfill a campaign promise, "is winding down his time in the White House by defending fresh military action in that nation," writes Jennifer Bendery in The Huffington Post.
The speech that President Obama made last night was as much an anti-ISIS speech as it was a pro-American speech, as Newt Gingrich said afterwards on CNN. And there is nothing wrong, or surprising, about that. Every U.S. president beats his chest in every speech, whatever the time or occasion. It's mandatory.
But mixing the issues of fighting terrorism and the revival of the auto industry together in the same speech just doesn't sound right. Obama went from war commander to used car salesman in a span of twenty minutes.
The biggest error of the speech wasn't even about ISIS, but about Russia. President Obama said, "It is America that has rallied the world against Russian aggression and in support of the Ukrainian people's right to determine their own destiny."
There is no evidence whatsoever that Russia has committed aggression against Ukraine. The problems there arose when the democratically elected government in Kiev was replaced by Washington with a neo-Nazi regime.
But President Obama wasn't totally dishonest in his speech. He was upfront about the limits to American power in confronting ISIS. Obama made many wise statements. He said at one point that the Islamic State was neither Islamic nor a state. That is something that not even so-called Muslim leaders have the courage or the moral conscience to say.
President Obama is completely right that the threat that ISIS poses to the region, and the wider world to a certain extent, has to be faced by local actors and regional governments.
But there is no amount of hair pulling that can be done to get Saudi Arabia, Qatar, Kuwait, UAE, and Turkey all on board with the U.S.-led anti-ISIS campaign. They see ISIS as a useful tool, as does Washington, and Obama's prime-time denouncements hasn't suddenly ended the group's usefulness.
The simple truth is that Sunni Muslim political leaders and princes have abdicated their moral and political responsibilities. They have sided with ISIS in its war against Shiites, Christians, Kurds, Yezidis, and other minorities, and they cannot turn back now even if they wanted to. They have chosen terrorism as the means to exert their influence and spread chaos in Iraq and Syria.
Former Iraqi Prime Minister Maliki was on the money when he said in an interview earlier this year something to the effect that the ISIS snake will bite off Saudi Arabia and other Gulf states.
For now and the foreseeable future, the so-called Islamic State will flourish. Obama's half-baked strategy isn't designed to accomplish anything spectacular. Experts have pointed out that U.S. policy towards ISIS is full of holes and contradictions.
Indian historian and commentator Vijay Prashad said on Democracy Now, "It seems that the United States wants to have it both ways: on the one side, take on the Islamic State, and on the other side, continue with promoting chaos inside Syria. You cannot promote chaos and take on the Islamic State. You have to pick one particular strategy, and Mr. Obama actually has chosen both."
History will decide whether President Obama has made the right decision.


Deluxe Two Doubles Room - Deluxe room with two double beds and a view of Aspen town. All rooms incorporate custom furnishings and marble bathrooms.
Deluxe King Room - Deluxe room with a king bed and a view of Aspen town. All rooms incorporate custom furnishings and marble bathrooms.
Junior Suite - The signature Junior Suites feature a king bed, an intimate living area and a large entrance hall. Most also have a powder room and sofa bed. The St Regis Butler Service is on hand for any requests.
One Bedroom Suite - One bedroom suites offer ample space to unwind with a master bedroom with king bed and a separate living room. These suites provide views of the mountain, courtyard or town. Guests can also take advantage of the St Regis Butler Service.
Grand Deluxe King Room - Grand Deluxe rooms have a mountain view. All have custom furnishings with a leather bed and an exquisite marble bathroom.
Grand Deluxe Two Doubles Room - Grand Deluxe rooms have a mountain view. All have custom furnishings with a leather bed and an exquisite marble bathroom.
Having undergone a multi-million dollar refurbishment, the luxurious 5 star St Regis Aspen Resort exudes elegance and style, mirrored by its first class service and hospitality. With a concierge service available to guests and personal butler for those looking for that extra special level of attention, the St Regis aims to go above and beyond to cater for the most discerning of guests.
The beautiful rooms and suites at the St Regis enjoy stunning views of either the surrounding mountains or across the town of Aspen. Each room features a private bathroom, internet access, a mini refrigerator, flat-screen cable TV, bathrobes and designer furniture.
When it comes to dining, the culinary offerings at the St Regis are sure to please all tastes. The Velvet Buck restaurant presents modern mountain cuisine with a focus on local ingredients and primal cooking techniques. Alternatively, the Chef's Club invites up and coming award winning chefs to curate new menu items, in collaboration with the culinary team at the restaurant, for a unique dining experience. Guests can also opt to dine privately in their rooms if they wish or by the pool. Finally, after a hard day on the hill, what could be better than enjoying a handcrafted cocktail in the Mountain Social bar, with sweeping views of Aspen Mountain.
The St Regis is also home to a fantastic spa and wellness area for complete relaxation and rejuvenation. Featuring hot tubs, a fitness centre, outdoor heated pool and variety of massage and beauty treatments available to book, guests can feel truly pampered after a day on the slopes.


text:
Q: Cart page not working properly! As Iam trying to remove items from cart the price does not change once the page reloads? I am try to make a shopping cart where i store data in the session. The problem is when i delete something from the cart and once the page is realoaded the price changes back to the price that was before i deleted the product. here is the code
I am getting the data from session storage from backend and then iam updating it.
function updateBill(cos) {
  let billPrice = document.querySelector(".cost");
  billPrice.innerHTML = cos;
}

itemCon.forEach((item, i) => {
  increment[i].addEventListener("click", async () => {
    let data = await fetchData();
    let cost = parseFloat(data.totals / 100);
    let bill = 0.0;
    data.items[i].qty++;
    bill += parseFloat(data.items[i].price);
    cost += bill;
    //   console.log(cost, data.items[i].qty, price[i].innerHTML);
    data.totals = cost * 100;
    cost = setFormattedTotals(cost);
    data.formattedTotals = cost;
    updateBill(cost);
    await postData(data);
  });
  decrement[i].addEventListener("click", async () => {
    let data = await fetchData();
    let cost = parseFloat(data.totals / 100);
    if (data.items[i].qty > 1) {
      data.items[i].qty--;
      cost -= parseFloat(data.items[i].price);
      // console.log(cost, data.items[i].qty, price[i].innerHTML);
      data.totals = cost * 100;
      cost = setFormattedTotals(cost);
      data.formattedTotals = cost;
      updateBill(cost);
      await postData(data);
    }
  });
});

deleteBtn.forEach((it, i) => {
  deleteBtn[i].addEventListener("click", async (e) => {
    let data = await fetchData();
    let cost = parseFloat(data.totals) / 100;
    console.log("Totalc", cost);
    if (data.items[i].id === itemId[i].value) {
      let total = 0.0;
      total = parseInt(data.items[i].qty) * parseFloat(data.items[i].price);
      console.log("Total", total);
      cost = cost - total;
      data.totals = cost * 100;
      cost = setFormattedTotals(cost);
      noCon[i].innerHTML = "";
      data.items = data.items.filter((data, index) => index != i);
      updateBill(cost);
      await postData(data);
      window.location.reload(true);
    }
  });
});

const fetchData = async () => {
  const res = await axios.get(`/cartdata`);
  const data = res.data;
  return data;
};

const postData = async (data) => {
  await axios.put("/cartdata", {
    data: data,
  });
};

redpajama_set_name: RedPajamaStackExchange


text:
Home » With ESSER funds, Columbus School Board eyes facility needs, staffing possibilities
With ESSER funds, Columbus School Board eyes facility needs, staffing possibilities
Bethany Hutchinson 27 March, 2021
COLUMBUS JUNCTION — With more than $755,000 in federal assistance available to the Columbus School District through the second phase of the Elementary & Secondary Schools Emergency Relief Program, the school board met Thursday in a work session to consider several possible uses of the support.
Although no final decisions were made, the board focused on earmarking the funds for several facility needs and educational staffing possibilities.
The facility needs discussion began with district business manager Neil Mills outlining a five-year facilities plan that could use about $434,000 of the ESSER 2 funds.
Included in that plan was a $160,550 expansion of the district's 1:1 computer distribution to the Roundy Elementary School and additional technology equipment; $245,000 for a new chiller at Roundy; $23,785 for junior high heating, ventilation and cooling equipment; and $4,500 for breezeway heaters.
Another $279,188 in work, which would include a welding exhaust system, wood shop dust collection, new middle school doors that would comply with the state fire code, a walk-in freezer at Roundy and carpet in the administrative building were also part of the plan, but would not qualify for ESSER 2 funds.
Other major potential future expenses facing the district, but whose cost had not yet been determined, included asbestos removal in the middle school and other areas, repair or replacement of the Roundy and high school library roofs and a new high school kitchen hood.
The board reviewed the Roundy chiller replacement project with Tim Fehr, a mechanical engineer with Shive-Hattery, Inc., Cedar Rapids.
Fehr described several options for that project, including replacing the current chiller and incorporating a hot/chilled water system, a nearly $1.7 million project; installing a hot/chilled water system coupled with a geothermal wellfield, a $2.56 million option; installing heat pumps with a geothermal field, the same system the secondary campus has, which could cost nearly $3.7 million.
Since that funding would exceed the district's ESSER and Physical Plant and Equipment funding, board members indicated the district would need to seek a bond referendum.
Board members agreed there were not enough facts to present to the public and requested Fehr to review the district's utility usage and determine the cost of a smaller chiller since the initial cost estimates used a chiller that apparently would be larger than necessary.
The board later discussed a revised Teacher Leadership Compensation Plan for Fiscal Year 2022. Superintendent Jeff Maeder outlined the revised plan, which would replace a modified plan adopted by the board last year.
Maeder and other school administrators stressed the revised plan was needed to boost leadership capacity within the certified staff and to improve the district's instruction and learning programs.
Under the revised plan, a director of instruction and two instructional coaches would be hired by the district. Additional stipends would be paid to members of the Building and District Leadership Teams.
Currently the district has a director of instruction and an induction coach provided by the area education agency.
The new plan would allow the district to spend down an existing $260,990 carryover in funds that must be used for teacher leadership training. Once the carryover is used, the district can apply for new funding from the state.
In final action, the board also discussed adding a new prekindergarten program and a third section of sixth grade in the elementary; and a half-time math interventionist, half-time math teacher and half-time Extended Learning Plan staff member at the secondary.
The board is expected to continue discussing and possibly act on the proposals at its regular meeting on March 29.
Tags: board Columbus ESSER eyes facility funds possibilities School staffing
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text:
Guest Blog: Henry Paul On Marshall Tucker
by Henry Paul
My first recollection of The Marshall Tucker Band was hearing them on the radio and seeing their records in the store. This was probably around 1974. I loved their country music influences and the image they projected with the artwork on their albums. I knew they were connected to the Capricorn Records scene in Macon and they represented a version of my dream come true.
Just before the release of The Outlaws' first album we got a chance to open for the Tucker band in a small theater somewhere in Georgia. I remember how excited we were to be working with a band of their caliber and musical character.
After the show that night Tommy Caldwell came to our dressing room to say hello and introduce himself. He complemented us on our performance and asked us if there was anything we needed. We told him we were running low on beer, so he gave us two cases of ice cold Coors. This was before Coors was sold in the east and it was a much sought after rarity. Well, needless to say this made quite an impression on me. Tommy's kindness and outgoingness that night defined him as a person and it became clear to me that he was the band leader and that he ran to organization from a position of strength and generosity.
With The Outlaws rise to stardom the following year we had the opportunity to work with the Tucker boys a lot. I was always impressed by the band's power and unique musical personality. I think Tucker commanded more respect than any other band short of The Allman Brothers, and it was clear when you were in the presence that you were in the company of grown men! From the Marine Corps tattoos on their arms to the close knit group of professionals they hired to help them in their work, these were serious people doing great work without the bullshit trappings of excessive rock and roll stars who pretend to be bad asses.
Some of my fondest recollections of the Tucker Band were Tommy's boots with golf spikes in the bottom that he wore with shorts to play golf in; Toy's incredible talent as a player and a songwriter; Doug Gray's seemingly effortless range and vocal power; Paul Riddle's energy and intensity a drummer; George McCorkle's song "Fire On The Mountain;" Jerry's jazz influence; and their Silver Eagle bus all decorated inside with western style hardware and leather.
This was a band of intense professionals who dominated the rock and roll world for a moment. To this day I respect them more than any other band of the time.
Henry Paul has come full circle as a past and present member of The Outlaws, as well as country hitmakers Blackhawk, The Henry Paul Band and Brothers of The Southland. Visit henrypaul.com
South Carolina,


High school teacher Lindsey called in to share an unexpected occurrence of genealogy serendipity.
Here the original Genealogy Gems Podcast episode 185 where George Ella Lyon reads her poem.
StoryWorth gives your loved ones a reason to spend time with their favorite memories and share them with you giving you opportunities to become closer, even when you live far apart. It's an easy and thoughtful gift even at the last minute.
I'm organizing and digitizing my Grandmother's old home movies with Video Conversion Experts. I told my uncle about it and now he's sending me the rest of his old home movies! Video Conversion Experts is the company that Dr. Haas used to convert his films. They did an exceptional job in post production restoration, and are known for this work in the film industry. They are the ideal company to go with if you want to invest in the highest quality of restoration. They are currently running a terrific 35% off sale now through 12/21/18.
Discount is valid on: video tapes, movie film, audio reels, audio tapes, slides, negatives, photos & specialty film.
"I loved this episode Lisa! Anna's song is so beautiful too! I learned a lot and the way you shared this story was wonderful. A favorite gem for sure."
"I'm loving the new narrative/profile episodes and had noticed the evolving voice and style in GGP 223. You and your team are wonderful writers...David Haas' story reminded me of my good friend Mark Holtze. An editor in Toronto, Mark has digitised all of his grandfathers' 16mm vacation films from across Canada in the 50s, 60s and 70s. They are brilliantly presented. Mark is very talented. I think they're worth sharing with your listeners. I don't know Mark's connection to this posting specifically but it's an amazing one on his playlist."
I've used RootsMagic for years and love it. You will too!
You can use Playlists to group the videos you find by topic. You could create playlists for locations, timeframes, people and so on. Sign in with your free Google account which will give you access to your YouTube "channel." When you find a video, under the title of the video click the plus sign that says "Add to". Select a playlist from the playlists listed in the dropdown menu. These are playlists you have already created in your account. If it's a long list, use the search box to search for a playlist title. Or create a new Playlist by clicking "Create New Playlist" at the bottom of the menu.
If you would like to have even more control over organizing the videos that you find, and you want to be able to add your own notes and memories, consider using Pinterest. In your free Pinterest account you can create as many boards as you want. Create a board for each topic (much like with the Playlists I suggested previously) and save YouTube videos to them. And of course, you can save any other online content "memories" that you find along with them if you want. The beauty of pinning is that you can add your own notes and memories, plus you can set the video to begin at any point within the video that you want. Simply click "Share" under the video in YouTube, and click to check the box for "Start at." Next, click on the player timeline that runs across the bottom of the video on the spot where you want the video to begin playing. Finally, click the Pinterest icon in the Share area to pin it to your Pinterest board of choice.
Thursday, December 13th. The important holiday business of viewing such classics as "It's A Wonderful Life" and "A Christmas Story" on home TVs owes much to a technological advance this month 80 years ago. In December 1938, Russian-American engineer Vladimir Zworykin was awarded two patents for cathode ray tubes. One was for the iconoscope to capture video images. The other was for the kinescope, which displayed television and computer monitor images for decades until the advent of flat panel screens. Whatever the ills of TV programming, obviously the American people consider it an appliance for a wonderful life. More than 98 percent of American households own at least one set, a percentage that has held steady for years and across all age groups.


text:
Акулько () — город и муниципалитет в Мексике, входит в штат Мехико.

Муниципалитет расположен на северо-западе штата. Название происходит из науатля.

Центр муниципалитета — город , хотя и город, и муниципалитет часто называют «Сан-Херонимо-Акулько».

Муниципалитет расположен в 110 км от Мехико, и известен, согласно «», своими изделиями ручной работы и сырами. Населения Акулько составляет  человек. Мэр или президент муниципалитета Акулько — Хорхе Альфредо Оснорнио Виктория.

Примечания

Муниципалитеты Мехико
Города Мехико

redpajama_set_name: RedPajamaWikipedia


Today I'm bringing you an Adobe Lightroom tutorial in two different ways.
Lightroom presets are a key component in speeding up the photo editing workflow. You can make them yourself (time consuming) or you can buy them for next to nothing from a number of different online stores. Once you've purchased them, you'll need to install them, and that's what I'm going to show you how to today – in less than 30 seconds!
Actually I'm going to give you two videos.
The first video shows you the best way to install Lightroom presets with the sub 30 second method, and if you're a reasonably confident computer user with some very basic Lightroom knowledge this will be all you need. The second video takes things a little slower, and discusses some of the potential pitfalls if you are having some troubles. I was compelled to create this first video because I found a ton of tutorials online for this process and the videos ranged in length from 8 minutes all the way up to 19 minutes. Whilst I do see the benefit of such great detail for some users, I also thought that they were all unnecessarily long and drawn out for those users that are already fairly confident with their computer and the Lightroom environment.
Hit the ground running. No fluff. This video will only walk you through the best (and fastest) way to install Lightroom presets.
To compliment the simplicity of this first video, I'll keep the written version of these instructions equally brief. For some folks, this will be enough of a memory jog for how to do this. For anyone looking for more detail, please view the second video and elongated instructions further down the page (which also shows a second method for installing the presets). If you have additional questions, there's an FAQ at the bottom of the page as well!
Step 1 – If you have purchased some Lightroom presets, ensure that you have unzipped the file to reveal the folder containing the presets.
Step 2 – In Lightroom, click the Preferences option in the main menu, located under the Lightroom tab.
Step 3 – Under the Presets tab in the preferences menu, click the button that says Show Lightroom Presets. This will open your file browser and show the parent folder called Lightroom location for storing presets.
Step 4 – Double click on the folder labelled Develop Presets.
Step 5 – Open a second separate window in your file browser and navigate to the folder which contains the Lightroom presets you want to install. Drag the folder of new presets from this second window, into the Develop Presets folder in the first window.
Step 6 – Shut down Lightroom and the re-open it. Your presets will now be visible in their folder in the Presets section of the Develop tab.
If you're a real Lightroom beginner, or just using presets for the first time, that first video probably wasn't for you. This second video walks through the process in much more detail and also explains some of the common issues that people have when installing Lightroom presets for the first time.
This second video actually explains two methods for installing Lightroom develop presets. The first method in the video is the same as the method described in the first video on this page, although I run through things a little slower this time. In the step-by-step guide below, I'll repeat the process described further up the page in the first section, but similar to the more in-depth style of the second video, I'll explain the process in a bit more detail.
Step 1 – In most circumstances you've probably downloaded multiple Lightroom presets simultaneously as a zip file. The first thing you need to do is open up your file browser and locate the zip file on your hard drive. Once this is located, you'll need to unzip the folder so that we can access the develop resets that are inside it. On a Mac, this is as simple as double clicking the zip file. As soon as you do this, a folder with the same name as the zip file will appear within the folder that contains the zip. On a PC, do not double click the zip file! Instead you need to right-click on the zip file and select the option that says "Extract All".
Step 3 – Navigate to the Presets tab within the Preferences menu and then click the button that says Show Lightroom Presets Folder. This will open up your computers default file browser again, and the Lightroom folder will be highlighted and selected. Double click the Lightroom folder to open it, and within that folder, once it has opened, double click the folder called Develop Presets. Inside this folder you will find two pre-existing folders. One is called Lightroom Presets, and the other is called User Presets. That first folder is where the default presets are stored, these are the small number o basic presets that come with Lightroom when you install it. The second folder, User Presets, can basically be ignored. If you haven't yet created your own presets in Lightroom, this second folder will be empty. Either way, for our purposes right now you can just ignore it. All you need to know is that we are going to leave both those folder as-is. We will not be putting any files or folder into them, so just ignore them!
Step 4 – We now need to gather both of the file browser windows we have discussed, together on the same screen. In one panel I want you to keep the Develop Presets folder open, and in the other panel, I want you to have the the download folder that contained your downloaded zip file, and now also contains the expanded folder of presets. Now, we simply drag the preset folder into the Develop Presets folder so that it's alongside the User Presets folder and the Lightroom Presets folder.
Step 5 – At this point, it's very important that you close down Lightroom and re-open it again. Unless you do this, the imported presets will not appear. Once you've done this, you'll find the presets panel underneath the navigation panel, once you have selected the Develop module. People often get tripped up at this point because they are still in the Library module! You must make sure you are in the Develop module, where you will now see your new folder of freshly installed Lightroom CC presets.
Step 1 – Locate your downloaded Lightroom Presets and unzip them if they have been compressed. On a Mac, simply double click the zip file to do this, on a PC, right-click and then use the option to "Expand All". Once this is done, you can close this file browser window, we won't be needing it anymore for this particular installation method. All we needed to do there was make sure the presets aren't zipped up.
Step 2 – Open Lightroom, choose the Develop module and find your way to the Presets panel on the left side of the screen. If this is your first time importing Lightroom Presets then you'll see a preset folder called User Presets, and then several other that all start with the word "Lightroom" – such as Lightroom B&W Presets, or Lightroom Effects Presets. We need to right click on any of those existing preset folder and then choose the option to create a "New Folder". Give the folder a name that helps you to identify the new presets we are trying to install.
Step 3 – Right click on this newly created folder and choose the option to "Import…". This will open a dialogue box that allows you to specify which presets you install into this folder. Navigate to your unzipped preset files, select all of them and then press the Import button.
This second method has some advantages and disadvantages. It forces you to name the new Lightroom preset folder, whereas the first method simply names the folder based on the name of the zip folder that you downloaded. On the plus side though, this second method allows you to be much more selective about which presets are installed, since you are having to manually select them, rather than blindly importing everything as in the first method. This could be very useful if you have purchased a bundle that contains many hundreds of presets, and perhaps you're only interested in a small number of them, for example, all of the ones that are applicable to landscape photography.
Hopefully this clears everything up! Two different methods for installing Lightoom CC develop presets.


text:
Q: Consecutive Javascript script tags in an HTML file I have a .jsp file which is outlined below. Note that:

*

*There are two script tags

*The first script tag has the Javascript type associated with it, the second doesn't

*The second script tag is directly after the first

*The second script tag contains a function that is invoked from inside the first

    <div>
        <!--  various bits of HTML and JSTL etc -->
    </div>

    <script type="text/javascript">
        runWhenPageReady() {
            doSomething();
        }
    </script>
    <script>
        function doSomething() {
            //do something
        }
    </script>

We have one user whose browser doesn't load the page correctly, and the console returns the following error:
Uncaught ReferenceError: doSomething is not defined

How do browsers evaluate  tags - is the fact that the function is defined in a different <script> tag from the first the likely culprit? Are there any problems associated with joining the two <script> tags together?

A: I would have expected the error in any browser.
A <script> tag is executed after the closing tag is reached. So when the first tag is closed, the function definition has not yet been processed. This should break with "Uncaught ReferenceError: foo is not defined" at the time the function is invoked:

<script>
  foo();
</script>
<script>
  function foo() {
    console.log("foo");
  }
</script>

If we reverse the scripts, the function will be defined at the time it is invoked, and everything works:

<script>
  function foo() {
    console.log("foo");
  }
</script>
<script>
  foo();
</script>

If we join the scripts together, it will work in either order, since within a single script, function will be hoisted to the top:

<script>
  foo();

  function foo() {
    console.log("foo");
  }
</script>


text:
Voting Poll Results: Majority Believe Bankruptcy Reform Necessary, But Not by a Large Margin
WEST PALM BEACH, Fla. - Bankruptcy reform has been a major issue for CUNA and NAFCU the last five years, but what do credit unions think? According to Credit Union Times' just expired voting poll, a majority believe that the current bankruptcy reform legislation making its way through Congress should...
By Staff Writer | April 05, 2005 at 08:00 PM | The original version of this story was published on Credit Union Times Magazine