Selection Of Grains Research Articles

Efficiency of Two Cycles of Pedigree Line Selection in Bread Wheat (Triticum aestivum L) under Late Sowing Date

The current study aimed to assess the efficiency of two cycles of pedigree line selection in bread wheat (Triticum aestivum L) in late sowing date during four successive seasons from 2011/2012 to 2014/2015 at Fac. Agric. Farm, Assiut University, Egypt. The genetic materials were two segregating bread wheat populations i.e. Debeira x Sahel and Giza 165 x Sakha 93. The genotypic (gcv) and phenotypic (pcv) coefficients of variation for grain yield/plant decreased from 14.90 and 17.12 in base population (F4) to 3.98 and 6.16% after two cycles (F6) of selection in population I and from 21.93 and 22.65 (F4) to 2.68 and 8.85% (F6) in population II, respectively. The same trend could be found for correlated traits in both populations. Grain yield/plant and number of spikes/plant in the two populations showed low heritability after two cycles of selection compared to their values in base populations. After two cycles of pedigree line selection for grain yield/plant, selections mean in the F6 was 17.82 g for population I compared to their parents Debeira (15.83 g) and Sahel (11.94 g) as well as the bulk sample (13.38 g). Also, the selections of population II averaged 18.78 g compared to the less values of 12.41, 15.09 and 14.19 g for both parents Giza 165, Sakha 93 and the bulk sample; respectively. The selected families in the F6 surpassed the better parent and unselected bulk sample for number of spikes/plant, biological yield/plant, weight of spikes/plant, plant height, spike length and number of spikelets/spike. The observed direct responses of pedigree line selection for grain yield/plant (selection criterion) were 33.18 and 32.35; 12.57 and 24.45; and 36.58 and 28.39% over two cycles of selection as accounted from unselected bulk sample, better parent and mid parents in population I and II, respectively. The results revealed that the mean of family score for selection response (FSSR) over all selected F6 family of Model 1 recorded the highest value (34.57 and 36.19%), followed by Model 2 (31.50 and 33.12%) and Model 7 (29.52 and 31.12%) in population I and II, respectively. In general, the obtained results revealed that the direct pedigree line selection for grain yield/plant in wheat scaled to be powerful tool in late sowing date for improving the grain yield and be effective to get high yielding lines.

Dietary Sources of Phosphorus among Adults in the United States: Results from NHANES 2001-2014.

Interest in the health effects of dietary phosphorus is burgeoning, yet sources and trends in phosphorus consumption have not been well characterized. We describe trends in and primary sources of dietary phosphorus in a nationally representative sample of 34,741 US adults, 20+ years old (NHANES 2001–2014). Dietary sources of phosphorus were estimated in nine food groups and 26 food categories. Phosphorus consumption was expressed in absolute intake, phosphorus density, and proportion contributed by dietary sources. Between 2001 and 2014, dietary phosphorus intake increased from 1345 to 1399 mg/day (p-trend = 0.02), while calorie intake slightly declined (p-trend = 0.1). Grains were the largest dietary phosphorus source, followed by meats, and milk products. Soft drinks accounted for just 3.3% of total dietary phosphorus. Phosphorus intake from grains increased 68 mg/day (p < 0.001), 25 mg/day from meats (p = 0.02), and decreased 75 mg/day (p < 0.001) from milk products. Dietary phosphorus intake and the phosphorus density of the diet are increasing. Grains are an important dietary phosphorus source that has increased in total consumption and phosphorus density. Further research is needed to determine if this is due to individuals’ selection of grains or the composition of those available.

Study on Shaking Selection of Grains for Combine Harvester

Study on Shaking Selection of Grains for Combine Harvester

Genetic Variability, Correlation, Path Analysis and Discriminant Function of F2 Generations Population in Bread Wheat (Triticum Aestivum) = التباين الوراثي والارتباط وتحليل المسار ودالة التفاضل وقوة الهجين لهجن الجيل الثاني الواعدة في حنطة الخبز

Grains of eighteenth F2 generation produced by using Factorial Mating Design through hybridization between six parents as male named [ATTLA (1), MILAN (2), Acsad 8 (3), Acsad 17 (4), Noor (5) and Cross bred-6 (6)] and three parents as female named Mexipak (7), Aras (8) and Ipa 99 (9)] cultivated on 15 Nov. 2011 at the Agricultural Research Station/Salahaddin University/Erbil using a Randomized Complete Block Design with three replications in order to select the best hybrids. Some growth traits and yield and its components were studied, and the path coefficient analysis, discriminant function and heterobeltiosis were estimated. The results showed significant genotypic, phenotypic and environment variation in all characters. Moderate values of heritability in broad sense were exhibited for plant height (52.99%), spike length (49.94%), 1000-grain weight (50.18%) and grain yield/plant (41.65%). High genetic advance were found in grain yield/plant. Significant positive phenotypic and genotypic correlation was observed between grain yield/plant and all characters except flag leaf area. The genotypic correlation coefficients were higher than their respective phenotypic ones. Phenotypic path coefficient analysis showed that high and positive phenotypic direct effects on grain yield were exhibited only by biological yield/plant (3.24). While highest positive genotypic direct effects on grain yield were exhibited by grain number/spike (0.74) and spike number/plant (0.62). The results of discriminant function indicated that the inclusion of grain number/spike increased the efficiency of the discriminant function by 22.10% than direct selection for grain yield/plant alone, which was used as a criterion for the selection of superior genotypes. The genotypes which gave high values in the selection index also gave a high values in the productivity score. Based on that and if we want to select 10% of the better genotypes, we selected [7 × 3], [7 ×5], [7 × 2] and [7 × 6] genotypes which showed also desirable heterobeltoises in most traits in order to continue the breeding for the F3 and next generation.

Selection of Synthesis Corundum Grain in Grinding Flat Parts from Hardened Steel 30ChGSA by the Macrogeometry Criterion

The stochastic nature of grinding predetermines the necessity of attracting statistical methods to predict output parameters. In this research the form accuracy indices of flat workpieces EFEmax (the main parameter) and two additional indices EFEa and EFEq called the arithmetic average and the quadratic average, respectively are used (GOST 24642-81). In the conditions of violating normality and homoscedasticity of distributions the selection of the grain in the Norton high porous wheels (HPW) made of synthetic corundum 5SG (46, 60) K12VXP is made with an emphasis on a non-parametric method, wherein medians and quartile latitudes are used as one-dimensional frequency distributions. This paper states that grinding by the coarse-grained HPW 5SG46 in comparison with the small-grained 5SG60 made it possible to increase the form accuracy by the predicted medians within the same accuracy quality class: for EFEmax – TFE7; for EFEa and EFEq – TFE6. The precision of the form accuracy of the parts 30ChGSA increased most significantly: for EFEmax it increased by 5 times, for EFEa by 3.1 times, and for EFEq by 4.2 times. The fact that the heights of microasperity remained practically at the same level , μm; , μm was due to the features of the synthetic corundum grain structure. In this study the EFEmax parameter is used for selecting the wheel grain. The auxiliary parameters of form accuracy are used in calculating the correction indexes of basic models in the multivariate dispersion analysis because they have more information about the status of the part surface.

Genetic evidence for differential selection of grain and embryo weight during wheat evolution under domestication.

Wheat is one of the Neolithic founder crops domesticated ~10 500 years ago. Following the domestication episode, its evolution under domestication has resulted in various genetic modifications. Grain weight, embryo weight, and the interaction between those factors were examined among domesticated durum wheat and its direct progenitor, wild emmer wheat. Experimental data show that grain weight has increased over the course of wheat evolution without any parallel change in embryo weight, resulting in a significantly reduced (30%) embryo weight/grain weight ratio in domesticated wheat. The genetic factors associated with these modifications were further investigated using a population of recombinant inbred substitution lines that segregated for chromosome 2A. A cluster of loci affecting grain weight and shape was identified on the long arm of chromosome 2AL. Interestingly, a novel locus controlling embryo weight was mapped on chromosome 2AS, on which the wild emmer allele promotes heavier embryos and greater seedling vigour. To the best of our knowledge, this is the first report of a QTL for embryo weight in wheat. The results suggest a differential selection of grain and embryo weight during the evolution of domesticated wheat. It is argued that conscious selection by early farmers favouring larger grains and smaller embryos appears to have resulted in a significant change in endosperm weight/embryo weight ratio in the domesticated wheat. Exposing the genetic factors associated with endosperm and embryo size improves our understanding of the evolutionary dynamics of wheat under domestication and is likely to be useful for future wheat-breeding efforts.

SELECTION FOR GRAIN YIELD IN BREAD WHEAT UNDER NORMAL IRRIGATION AND DROUGHT STRESS CONDITIONS.

To improve grain yield/plant, two cycles of pedigree selection were achieved in a segregating population of wheat (Triticum aestivum L.)in theF4, F5 and F6 generations under normal and drought stressed environments. Significant differences (p<0.01) among the selected families for the selection criterion; grain yield/plant were observed in all the studied traits under the two environments in F4 and F6-generations. After two cycles of pedigree selection for grain yield/plant the values of gcv and pcv were decreased from F4 to F6-generation in all traits under both environments and were very close to each other, resulted in very high estimates of heritability in broad sense which calculated from the expected mean squares. The average direct gain in grain yield/plant was 90.20, 70.14 and 37.64, 52.46% from the bulk sample and the better parent under normal irrigation and drought stress; respectively. Under irrigation, the best five families, No.127, No.146, No.273, No.377 and No.452 outyielded the better parent Giza 168 by 38.87, 46.57, 42.63, 56.75 and 64.96%; respectively. The family No.452 was like Giza 186 in earliness. Under drought stress, selection for grain yield/plant delayed maturity by 8.59% from the better parent, but, not from the bulk sample. The best families in grain yield; No.202, No.296, No.379, No.389, No.395 and No.397 showed significant delay in maturity than the earlier parent. The best two families No. 92 and No.306 were early as the earlier parent Sisd4 and showed significant (p<0.01) grain yield/plant from the better parent Giza 168 of 26.46 and 59.72%; respectively. In the F6-generation under both environments all the traits which showed positive genotypic correlation with grain yield, days to heading, plant height, biological yield/plant and number of spikes/plant showed negative correlations with grain weight/spike, number of grains/spike, and 100-garin weight.

Simulation of competitive grain growth upon the directional solidification of a Ni-base superalloy

Using the numerical simulation in the CA-FE module of the ProCAST simulation program, a systematic investigation of competitive growth of grains in a thin plate has been performed over a wide range of values of the temperature gradient and solidification rate. It has been established that the result of the simulation in the case of converging grains depends on the only parameter, i.e., the ratio of the value of the overgrowth of the grain with the preferred orientation to the size of the cell of the computational grid. Thus, the size of the cell is an important adjusting parameter of the model and must be coordinated with the parameters of the dendritic structure under given growth conditions. The grain with the preferred orientation always displaces neighboring diverging grains. The converging grains are eliminated if their deviation from the vector of the temperature gradient exceeds 20°. At the smaller angles of deviation, the result of the competitive growth depends on the size of the computational cell and varies from their joint growth (at the cell size of 5 μm) to the displacement of grains with the preferred orientation (at the cell size of 20 μm). However, all of the results of the simulation agree with the experimental data available in the literature. For the efficient selection of grains with the preferred orientation, regimes with a low temperature gradient and high growth rate are favorable.

Grain Sizing in Porous Media using Bayesian Magnetic Resonance

We introduce a Bayesian inference approach to analyze magnetic resonance data of granular solids. To characterize structure using magnetic resonance, it is usual to acquire data in k space which are then Fourier transformed to obtain an image. An alternative approach, adopted here, is to utilize the Rayleigh distribution observed in the signal intensity for a given k when a random selection of grains is measured in k space, to define a likelihood function for Bayesian analysis. This Bayesian likelihood function is used to noninvasively characterize grains within a porous medium on length scales below the practical resolution of magnetic resonance imaging. A pore size distribution is then calculated from the measured grain size distribution using a Monte Carlo approach. We demonstrate this general technique with specific examples of water-saturated rock cores.

Response to Pedigree Selection for Earliness and Grain Yield in Spring Wheat under Heat Stress

The objectives of this study were to estimate the response to direct selection for early heading and grain yield under favourable and stress environments and to study the correlated response of other studied traits. Two cycles of pedigree selection for earliness and grain yield/plant were completed on a segregating population of wheat in the F3-F5 generations. Selection for each trait was, separately and over environments, practiced at favourable, stress and over environments. After two cycles of selection for earliness, the realized gain reached to -2.19, -1.85 and -1.72% from the bulk samples for selection under favourable, stress and over environments, respectively. The realized gains from selection for increasing grain yield/plant were 17.32, 24.16 and 7.48% from the bulk samples for selection under favourable, stress and over environments, respectively. The antagonistic selection was more efficient than synergistic selection in changing the mean and in decreasing the sensitivity to environments. Selection for earliness was accompanied by undesired decrease in all correlated traits over the bulk sample at favourable, stress and over environments. However, selection for grain yield/plant was accompanied by late in days to heading and decrease in 1000-grain weight from the bulk sample at favourable, stress and over environments. Two families; No. 58 and No. 50 could be considered the best selected families resulted from selection for earliness and grain yield/plant, respectively which earlier and higher than the bulk sample under different environments. Pedigree selection for either earliness or grain yield/plant was effective in isolating genotypes for early heading and high grain yield.

Hop fields in crop rotation

A number of factors influenced the increased number of crops on Slovenian farms legal limitation of maize production to two years on the same field, introduction of integrated crop production and certain measures of the Slovene Agri-Environmental Programme. Crop rotation on hop fields that has already been analyzed on 22 hop growing and livestock farms in Spodnja Savinjska dolina in 2008 show that the maize monoculture has been supplemented by some other crops like wheat, barley, lucerne, clover-grass mixtures and high beans; compared to the conventional production in the past, the crop rotation is now longer. Phytosanitary adequacy of two- and three-year rotation could be improved with supplementary crops, that is with fodder crucifers (fodder rapeseed and rape, forage kale), green manure (white mustard, oil radish), legume crops (soya, peas, vetch, field bean, white lupin, crimson clover, Persian clover, Egyptian clover) and compound fodders like Landsberger mixture and mixtures of vetch with oat or barley. Prohibition to sow broad-leafed plants in the quarantine rotation due to hop wilting limits the selection of crops to grasses (Italian rye-grass) and fodder grains (maize, barley), but the farmers could increase the selection of grains with oats, rye, triticale, mixture of wheat and rye, millet, sorghum and Sudan grass. With the use of recommended crop rotations in two-, three- and four-year rotation, we can expect the increased influence of crop rotation on improved health condition of the new hop plantations in the future with simultaneous reduction of the use of pesticides as well.

Comparison of Automated Image-Based Grain Sizing to Standard Pebble-Count Methods

This study explores the use of an automated image-based method for characterizing grain-size distributions (GSDs) of exposed open-framework gravels by comparing the GSDs measured with the image-based method to distributions obtained with two pebble-count methods. Selection of grains for the two pebble-count methods was carried out using a gridded sampling frame and the heel-to-toe Wolman walk method at six field sites. At each site, 500-particle pebble-count samples were collected with each of the two pebble-count methods and digital images were systematically collected over the same sampling area. For the methods used, pebble counts collected with the gridded sampling frame were assumed to be the most accurate representations of the true grain-size population. Therefore, results from the image-based method were compared to the grid-derived GSDs for accuracy estimates; comparisons between the grid and Wolman walk methods were conducted to give an indication of possible variation between commonly used methods for the particular field sites used in the study. The grain-size comparisons were made at two spatial scales. At the larger scale, results from the image-based method were integrated over the sampling area required to collect the 500-particle pebble-count samples. At the smaller sampling scale, the image derived GSDs were compared to those from 100-particle, pebble-count samples obtained with the gridded sampling frame. The comparison shows that the image-based method performed reasonably well on five of the six study sites. For those five sites, the image-based method slightly underestimated all grain-size percentiles relative to the pebble counts collected with the gridded sampling frame, but the method performed well in estimating the median grain size (the average bias for ψ 5 , ψ 50 , and ψ 95 was 0.07ψ, 0.04ψ, and 0.19ψ, respectively). The Wolman pebble-counts yielded coarser results than the pebble counts obtained with the gridded sampling frame, especially for the smaller percentiles (the average bias for ψ 5 , ψ 50 , and ψ 95 was 0.20ψ, 0.16ψ, and 0.04ψ, respectively). Oversegmentation of large pitted grains in the image-analysis procedures was identified as a leading cause for failure of the image-based method at one of the sites. It is likely that lower degrees of oversegmentation and physical particle orientation contributed to the slight underestimation of all grain-size percentiles in the image-based method.

Grain Selection and Texture Evolution in Directionally Solidified Al-Zn Alloys

In a recent contribution, we have reported that dendrites in the aluminum-zinc binary system can change their growth direction continuously from $$ {\left\langle {{\text{100}}} \right\rangle } $$ to $$ {\left\langle {{\text{110}}} \right\rangle } $$ as the concentration of zinc C Zn increases from 5 to 90 wt pct.[1] This was interpreted as an influence of the hcp Zn element on the low anisotropy of the solid-liquid interfacial energy of aluminum. Seaweed morphologies were even observed at the start and end of this so-called “dendrite orientation transition” (DOT), i.e., for C Zn ≈ 30 and 55 wt pct. In the present work, we analyze how this DOT influences the selection of grains and the evolution of the texture in directionally solidified (DS) specimens. The solidification texturing of $$ {\left\langle {hk{\text{0}}} \right\rangle } $$ dendritic specimens is shown to be similar to that occurring in normal $$ {\left\langle {{\text{100}}} \right\rangle } $$ specimens. It is analyzed on a similar basis by considering a random orientation distribution of nuclei at the surface of the chill plate and a minimum undercooling criterion. This produces $$ {\left\langle {hk{\text{0}}} \right\rangle } $$ textures with grains that look fairly “equiaxed” in transverse sections. For seaweed morphologies, which also exhibit an $$ {\left\langle {hk{\text{0}}} \right\rangle } $$ texture parallel to the thermal gradient, the grain selection is slower and the grains appear more elongated in transverse sections. Their elongation occurs along a (001) plane, i.e., along a $$ {\left\langle {1\ifmmode\expandafter\bar\else\expandafter\=\fi{2}0} \right\rangle } $$ direction for $$ {\left\langle {210} \right\rangle } $$ seaweeds (C Zn = 30 wt pct) and along a $$ {\left\langle {1\ifmmode\expandafter\bar\else\expandafter\=\fi{1}0} \right\rangle } $$ direction for $$ {\left\langle {{\text{110}}} \right\rangle } $$ seaweeds (C Zn = 55 wt pct). The scanning electron microscopy (SEM) observations reveal that this elongation is accompanied by a microsegregation pattern that is mainly parallel to (001) planes. This indicates that seaweeds at the onset and end of the DOT grow with some type of layered structures, but their detailed growth and grain selection mechanisms are still unknown.

The Measurement of Structural Characteristics of Barley forShochuUsing Single-Kernel Characterization System 4100 Crush-Response Profiles

J. Inst. Brew. 111(2), 181–189, 2005 The selection of grain that is optimum for barley Shochu is not straightforward. Usually malting barley is used, but not all malting barley samples perform well in Shochu production. In addition there is a genotype × environment effect, so that a given variety may perform satisfactorily in one environment but not another. Therefore a method for testing samples for Shochu is required. This group has previously reported on the evaluation of barley for Shochu production using the Single Kernel Characterization System (SKCS) and demonstrated a significant correlation between the SKCS Hardness Index and pearling performance. The Hardness Index values are multivariate statistical predictions derived from an incremental change analysis of the crush-response profiles. In the present study, a detailed analysis was performed of the averaged SKCS Crush-Response Profiles of barley, obtained when measuring the SKCS Hardness Index. It was concluded that the morphological differences between averaged barley SKCS Crush-Response Profiles appear to allow barley varieties to be classified into four distinct classes. In addition, the elastic response to the crushing on the SKCS device of the aleurone layers of barley kernels yields a useful predictor of pearling quality /performance.

Detrital zircons as tracers of sedimentary provenance: limiting conditions from statistics and numerical simulation

U–Pb ages of detrital zircons in clastic sediments are potential indicators of sedimentary provenance and crustal evolution. To extract geologically significant information from such data, it is necessary that the zircons analysed in the laboratory reflect the sediment from which they were separated. Among other factors, this depends on the number of grains analysed. The probability that a detrital zircon in a sediment belongs to one of several populations (defined by their age or another well-defined parameter) is described by the binomial probability formula, from which detection limits and expected values for the accuracy and precision of population sizes can be derived. Monte Carlo simulation of sets of data with up to 120 individual analyses drawn from pools with known age probability density distributions shows that quantitative representation of the age distribution of the zircons in the host sediment is unlikely to be achieved in natural cases. Methods that assume such representation (e.g., age spectrum deconvolution, multivariate statistical analysis using probability density scores, and mass balance modelling) are therefore likely to give results of questionable significance. The best way to extract the potential information contained in detrital zircons may be a combination of random and nonrandom selection of grains for analysis; yielding two complementary sets of age data from each sample, the random fraction should comprise 35–70 grains or more, depending on the complexity of the age distribution. The use of trace element and Lu–Hf isotope data from the zircons dated by U–Pb will give additional, valuable information, which may facilitate interpretation of detrital zircon ages. The use of detrital zircon ages to limit the age of deposition of the host sediment is fraught with both geological and statistical sources of error, and is therefore discouraged.

A preliminary electron backscattered diffraction study of sintered NdFeB-type magnets.

This paper reports, for the first time, the use of electron backscattered diffraction (EBSD) to study orientation in sintered NdFeB type magnets. The magnetic properties of NdFeB magnets are greatly improved if a strong crystallographic texture is firstly achieved, namely, the direction of the c-axis is along the direction of magnetization. A systematic survey of sample preparation techniques showed that samples that were mechanically polished and then etched gave the most reliable EBSD data. Analyses were made using both fully automated EBSD scans and by EBSD measurements taken after manual movement of the beam. The EBSD results are presented as secondary electron SEM micrographs, orientation images and 001 pole figures. For the selection of grains investigated, the deviation of the c-axis was shown to be between 10 degrees and 30 degrees from the ideal [001]//magnetization direction. It is demonstrated that EBSD is a valuable tool for characterizing the microstructure and texture relationships and for assessing the performance of the processing routes of NdFeB magnets.

Method of Selection for Grain with Ventral Swelling in Malting Barley by Water Sprinkling During the Late-ripening Stage

ビール大麦の被害粒の一つである凸腹粒における耐性検定法確立のために登熟後期の散水処理の効果について検討した.国内外のビール大麦26品種・系統を用いて, 登熟後期の植物体に1日当たり50mmの水を連続2日間, これを5回実施することで供試品種・系統全てに凸腹粒を発生させることができた.その発生率は, 品種・系統間で異なり, 0.9～16.8%の範囲であった.これらのうち, 過去の自然条件で共通に供試してきた13品種・系統は, 人工降雨処理による発生率と自然条件下で多発生した年の凸腹粒発生率との間に有意な正の相関関係が認められた.また, 出穂・成熟期の早晩と発生の多少との関係を解析したところ, 凸腹粒発生率と出穂期および成熟期との間には, 相関関係は認められず, 熟期が異なる品種・系統を一度に検定できるものと考えられた.以上のことから, ビール大麦の登熟後期における散水処理は, 凸腹粒耐性の評価が可能であり, 凸腹粒耐性系統の選抜に利用できると考えられた.

A Simulation of Recrystallization Textures of Al-Alloys With Consideration of the Probabilities of Nucleation and Growth

The characteristic recrystallization texture components of cold rolled Al-alloys can be traced back to a growth selection of grains with an approximate 40º 〈111〉 orientation relationship out of a limited spectrum of preferentially formed nucleus orientations. Accordingly, recrystallization textures can be modeled by the multiplication of a function f(g)nucl describing the probability of nucleation of the various orientations and a function f(g)grow representing their growth probability.Whereas the growth probability can be accounted for by a 40 111 transformation of the rolling texture, the nucleation probability of the respective grains is given by the distribution of potential nucleus orientations, which is known from local texture analysis for the most important nucleation sites in cold rolled Al-alloys, cube-bands, grain boundaries and second-phase particles. If several nucleation sites are active simultaneously, the nucleation probabilities have to be weighted according to their respective proportions. For that purpose, the numbers of nuclei forming at the various nucleation sites were calculated according to a model approach proposed by Vatne et al. (Acta Mater 44, 1996, 4463–4473).The paper describes the model for recrystallization texture simulation in Al-alloys and gives examples of recrystallization textures simulated regarding a variation of different microstructural parameters to demonstrate the predictive power of the model.

Modeling the recrystallization textures of aluminum alloys after hot deformation

The recrystallization textures of aluminum alloys can be explained by a growth selection of grains with an approximate 40° 〈111〉 orientation relationship out of a limited spectrum of preferentially formed nucleus orientations. Accordingly, recrystallization textures can be modeled by the multiplication of a function f(g)nucl describing the probability of nucleation of the various orientations with a function f(g)grow representing their growth probability. Whereas the growth probability can be accounted for by a 40° 〈111〉 transformation of the rolling texture, the nucleation probability of the respective grains is given by the distribution of potential nucleus orientations, which is known from local texture analysis of rolled aluminum alloys to be cube bands, grain boundaries, and second-phase particles. The contributions of these nucleation sites are determined according to an approach to calculate the number of nuclei forming at each site, which is based on microstructural investigations of the evolution of the various nucleation sites during deformation. This article describes the model for recrystallization texture simulation in aluminum alloys and gives examples of recrystallization textures of AA3004 deformed in plane-strain compression at different deformation temperatures and strain rates.

Working Processes on Cereals: An Approach Through Microwear Analysis

The exploitation of cereal crops implies several working processes (e.g. preparation of land, harvesting, selection of grain, subsequent use or disposal of the straw, storage and food manufacture) that require the development of different specific working tools, such as hoes, sickles and mortars. Lithic tools which have been used to cut plants are usually identifiable because of their characteristic microwear traces. In the course of several research projects concerning microwear analyses of lithic assemblages from Neolithic, Chalcolithic and Bronze Age sites, many tools were discovered which have been used as sickles. In addition, many tools were observed which showed microwear traces differing from those on sickles and the microwear pattern of threshing sledges. This paper presents the results of research which aimed to reproduce these microwear traces and to interpret them on archaeological flint tools. We present different hypotheses put forth by other researchers in order to explain wear traces similar to those described here and propose that these tools were used to cut straw directly on the soil, either to separate grain from the straw and/or to deliberately cut the straw itself.