Ratio Of Grains Research Articles

Drought Stress, Elevated CO2 and Their Combination Differentially Affect Carbon and Nitrogen in Different Organs of Six Spring Wheat Genotypes

This study aimed to analyze the combined impact of CO2 and drought stress at the flowering stage on carbon (C), nitrogen (N), and CN ratios in leaves, stem, and grains of bread wheat. Six diverse bread wheat genotypes, comprised of two commercial checks, two landraces, and two synthetics derivatives, were grown at two levels of CO2, i.e., 400 ppm and 800 ppm, and drought stress was imposed at the flowering stage through progressive soil drying. Stem, leaf, and grain samples were taken at maturity and concentrations of C and N were determined. Our results indicate that the threshold value of fraction of transpirable soil water (CFTSW) at which it diverges towards closure of stomata was different among genotypes and a higher range of values was estimated under elevated CO2. Drought significantly increased C levels in leaves and N levels in grains but decreased N levels in leaves, which increased CN ratios in leaves. In contrast, drought significantly reduced CN ratios in grains. Genotypes differed significantly in N content in grains, where the landrace derivative L2 maintained the highest N content. Moreover, pronounced changes in leaf N and CN ratios were induced by the combination of elevated CO2 and drought stress. Additionally, combined correlation and biplot analyses indicate a strong positive association of grain CN (GCN) with grain number, weight, and grain yield. These effects possibly interact with drought to strongly interfere with the impact of elevated CO2. The differential performance of the tested genotypes shows that selection of appropriate germplasm is essential to maintain agricultural production.

Nitrogen Level Impacts the Dynamic Changes in Nitrogen Metabolism, and Carbohydrate and Anthocyanin Biosynthesis Improves the Kernel Nutritional Quality of Purple Waxy Maize

Waxy corn is a special type of maize primarily consumed as a fresh vegetable by humans. Nitrogen (N) plays an essential role in regulating the growth progression, maturation, yield, and quality of waxy maize. A reasonable N application rate is vital for boosting the accumulation of both N and carbon (C) in the grains, thereby synergistically enhancing the grain quality. However, the impact of varying N levels on the dynamic changes in N metabolism, carbohydrate formation, and anthocyanin synthesis in purple waxy corn kernels, as well as the regulatory relationships among these processes, remains unclear. To explore the effects of varying N application rates on the N metabolism, carbohydrate formation, and anthocyanin synthesis in kernels during grain filling, a two-year field experiment was carried out using the purple waxy maize variety Jinnuo20 (JN20). This study examined the different N levels, specifically 0 (N0), 120 (N1), 240 (N2), and 360 (N3) kg N ha−1. The results of the analysis revealed that, for nearly all traits measured, the N application rate of N2 was the most suitable. Compared to the N0 treatment, the accumulation and content of anthocyanins, total nitrogen, soluble sugars, amylopectin, and C/N ratio in grains increased by an average of 35.62%, 11.49%, 12.84%, 23.74%, 13.00%, and 1.87% under N2 treatment over five filling stages within two years, respectively, while the harmful compound nitrite content only increased by an average of 30.2%. Correspondingly, the activities of related enzymes also significantly increased and were maintained under N2 treatment compared to N0 treatment. Regression and correlation analysis results revealed that the amount of anthocyanin accumulation was highly positively correlated with the activities of phenylalanine ammonia-lyase (PAL) and flavanone 3-hydroxylase (F3H), but negatively correlated with anthocyanidin synthase (ANS) and UDP-glycose: flavonoid-3-O-glycosyltransferase (UFGT) activity, nitrate reductase (NR), and glutamine synthetase (GS) showed significant positive correlations with the total nitrogen content and lysine content, and a significant negative correlation with nitrite, while soluble sugars were negatively with ADP-glucose pyrophosphorylase (AGPase) activity, and amylopectin content was positively correlated with the activities of soluble starch synthase (SSS), starch branching enzyme (SBE), and starch debranching enzyme (SDBE), respectively. Furthermore, there were positive or negative correlations among the detected traits. Hence, a reasonable N application rate improves purple waxy corn kernel nutritional quality by regulating N metabolism, as well as carbohydrate and anthocyanin biosynthesis.

Enhanced Hybrid Algorithms for Segmentation and Reconstruction of Granular Grains From X‐Ray Micro Computed‐Tomography Images

ABSTRACTAccurate three‐dimensional (3D) reconstruction of granular grains from x‐ray micro‐computed tomography (µCT) images is a long‐standing challenge, particularly for dense soil samples. This study develops a machine learning (ML) enhanced approach to automatically reconstruct granular grains from µCT images. The novel academic contributions of this paper include (a) a hierarchical strategy based on parameter‐independent polygonal approximation, area, and concavity analysis, for the first time, to identify and eliminate both intergranular and intragranular voids; (b) incorporation of a recursive segmentation scheme and ML‐based grain classifier to avoid over‐segmentation; (c) novel modifications on the determination of splitting paths to enhance segmentation accuracy; and (d) an effective approach of assigning initial level set functions for reconstructing granular grains automatically. The hybrid ML algorithm is applied to µCT images of dense Mojave Mars Simulant. The results indicate that the proposed method can accurately segment grain clumps with unclear boundaries. The new automatic reconstruction algorithm eliminates ineffective operations and achieves a three‐fold increase in computational speed than previous methods documented in the literature. Ninety‐one percent of grains with distinct boundaries can be reconstructed and the reconstruction ratio reaches 81% even for grains without distinct boundaries. The overall reconstruction ratio of grains increases by 20% compared with previous methods, achieving a step‐change improvement for one‐to‐one mapping of real soil samples.

Biofortification of wheat in salt-affected soil through seed priming and soil application of zinc

ContextGiven the global significance of wheat production and consumption, it is imperative to achieve high yields of nutritious wheat grains. However, the inadequate availability of zinc (Zn) in salt-affected soils can aggravate salt stress, decrease wheat grain yield, and grain Zn concentration. This study compared the effectiveness of soil Zn application and seed Zn priming in increasing Zn biofortification and grain yield of Zn-biofortified wheat grown in alkaline-calcareous soil affected by salts. MethodsEighteen pots were filled with alkaline-calcareous soil containing elevated levels of soluble salts and exchangeable sodium (Na). The pots were subjected to soil Zn application (0 or 8 mg kg−1) and seed priming (control/non-, hydro-, or Zn-primed seeds) treatments, applied to a Zn-biofortified wheat (cv. Zincol-2016). Plant samples were collected at the heading and maturity stages to measure parameters related to plant growth and grain quality. FindingsSoil Zn application increased grain and straw yields across seed priming treatments by a maximum of 23 %, and seed Zn priming increased grain and straw yields across soil Zn rates by a maximum of 21 %. This yield response was accompanied by significant increases in grain potassium and Zn concentrations at maturity, as well as non-significant to significant increases in photosynthetic parameters (stomatal conductance, photosynthetic rate and transpiration rate) in flag leaves during heading. Additionally, compared to control, the combined treatment of soil Zn application and seed Zn priming decreased grain Na concentration by 14 %. Compared to control, both soil Zn application and seed Zn priming significantly increased grain Zn concentration. With the combined application treatment, the grain Zn concentration reached 27 mg kg−1, but it remained significantly below the desired level of >37 mg kg−1. Seed Zn priming decreased the phytate-to-Zn molar ratio in grains, while the treatments that received soil Zn application exhibited the lowest values of this ratio, potentially increasing Zn bioavailability to humans. ConclusionsThe findings suggest that soil Zn application is more effective in enhancing grain yield and Zn concentration, while seed Zn priming remains crucial in low-Zn and high-salt soils. Future research should optimize Zn application strategies for Zn-biofortified wheat cultivated in salt-affected fields.

DESIGN FEATURES OF GRAIN HARVESTING COMBINEERS CASE IH "AXIAL-FLOW" SERIES

Harvesting grain is a very important production process that must be carried out as quickly as possible to obtain high-quality grain. Here it is important that the equipment is adjusted to the structure of the plants, and the plants, in turn, are prepared for machine harvesting. When creating grain harvesting equipment, various factors are taken into account: agrobiological properties and the structure of plant organs, stand height and density, lowness, strength, humidity, size and weight of fruits, weight ratio of grain to non-grain part, stage of maturity and others. Currently, harvesting of grain crops is carried out by direct or separate combining. Direct involves performing several operations: cutting plants, threshing plant mass, separating grain from straw, cleaning grain from various impurities, as well as harvesting grain and non-grain part of the crop. It is important that the harvester performs these processes at the same time in the stage of full maturity of the grain. This harvesting method is suitable for bread mass that is not clogged and has ripened evenly. As for separate combining, here mowing of plants and their threshing are carried out separately. Providing the enterprise with high-performance harvesters and the level of their use significantly affect the gross harvest of agricultural crops. In case of violation of the calendar terms for harvesting grain crops by more than 10–12 days, grain losses can reach 25–30%. In order for such a situation not to arise, agricultural enterprises must have the required number of harvesters of the necessary capacity, which could ensure, in the optimal time, harvesting of agricultural crops. In order to give preference to one or another combine harvester model, you need to know not only its price, but also individual technical and economic characteristics and the cost of threshing a ton of harvest. Because this indicator reflects the cost of the harvester, operating costs, its productivity, reliability and cost of spare parts. Innovation is only accelerating. Over the past 20 years, the average productivity of self-propelled grain harvesters has increased almost four to five times. The level of computerization of mechanized operating technologies also increased. The demand for products of the grain sub-complex is only growing. Ukraine is dominated by a diverse fleet of industrial grain harvesters of foreign production, purchased both new and used, the use of these grain transport systems is expedient and relevant. The question of choosing a modern high-performance grain harvester and the question of its effective use remain relevant.

Influence of solid solution treatment on fatigue crack propagation behavior in the thickness direction of 2519A aluminum alloy thick plates

2519A aluminum alloy thick plates have excellent applications in the military industry due to their superior ballistic resistance and fatigue properties. However, the delamination cracking along the thickness direction of this alloy hinders its further utilization. To address this issue and enhance the fatigue properties of this alloy, the effect of single-stage solid solution treatment (SST) and two-stage solid solution treatment (DST) on the fatigue crack propagation (FCP) behavior in the thickness direction of the alloy was investigated. Compared to the optimum SST, the volume fraction of the secondary phase of the alloy was reduced by 28.6% after DST. The precipitated phases were finer with more uniform distribution, and the volume fraction and number density of the precipitation increased by 47% and 30%, respectively. The DST resulted in a lower fatigue crack growth rate (FCGR) and an increase of 2.92% in the critical stress intensity factor value (ΔKcr). The crack propagation mode of the alloy after SST was inter/transgranular crack propagation, while it was transgranular after DST. The aspect ratio of grain and the number of secondary phases in the alloy decrease after DST. Meanwhile, the grain boundary (GB) precipitation phase spacing, the precipitation-free zone (PFZ) width, and the spacing between the secondary phases increase. These changes result in decreased crack sources in the alloy and reduced the bridging effect of secondary phases on fatigue cracks, thus improving the fatigue performance of the alloy.

Response of nutrients uptake and bio fortification to the optimum zinc fertilizer doses for maize crop (Zea mays L.)

Zinc (Zn) is an essential micronutrient that participates in several plant metabolisms. Soil application of Zn is an effective strategy to increase the productivity and Zn concentration in maize grains, but the effect of Zn fertilizers on the nutrients uptake and biofortification still needs more studies. In this study, a greenhouse plot experiment was conducted to evaluate the effect of the optimum Zn fertilizer doses (0, 5.7, and 11.4 kg ha−1) on the nutrients uptake and Zn biofortification of maize crops. Zn applications were found to increase significantly the transpiration rate; photosynthesis rate, Zn, and P concentration in the maize shoot at the VT (Tasseling) stage as well as the grain Zn and maize grain yield. P, Mg, and phytic acid (PA) concentration in grains was also increased with a Zn application of 11.4 kg ha−1. The PA/Zn molar ratio in grains decreased due to the Zn application doses as compared with the control treatment, but there was no significant difference between Zn 5.7 and 11.4 kg ha−1 doses, while Zn 5.7 kg ha−1 achieved a higher PA/Fe molar ratio in maize grains compared to other treatments.

Reduced order model for hard magnetic films

In the pursuit of rare earth-lean permanent magnets for green technologies, microstructural optimisation offers a promising strategy to enhance coercivity while minimising critical element content. For this approach, the combination of experimental work on hard magnetic films and numerical investigations is necessary. However, computational limitations restrict micromagnetics to small systems, motivating the development of a reduced order model for investigating large multigrain systems. The model is based on the embedded Stoner-Wohlfarth method and is used to investigate the influence of a nonmagnetic grain boundary phase thickness and the aspect ratio of the magnetic grains on the overall coercivity. It is possible to simulate large NdFeB multigrain structures which can be compared to hard magnetic films. We derive design recommendations to increase coercivity by increasing the grain boundary phase thickness and the aspect ratio of the grains in hard magnetic materials.

EFFECT OF CULTIVARS AND HARVEST DATES ON SOME TRAITS OF YIELD IN RICE

A field experiment was carried out at Rice Researches Station in Mashkhab, Najaf in 2020 and 2021 seasons to study the effect of cultivars and harvest date on some traits of rice yield. Randomized complete block design was applied within split-plot with four replications. Five cultivars of rice (Amber 33, Yasmin, Dijlah, Amber-albaraka and Furat 1) were distributed in the main plots and five harvest dates (harvest at physiological maturity and harvest after 7, 14, 21 and 28 days of physiological maturity) in the sub-plots. The results showed significant difference among cultivars, and superiority cultivars of Dijlah, Furat 1 and Yasmin in recording the highest yield due to its superiority in number of grains per panicle or weight of grain. It can be concluded that traits of grain number in panicle and weight of 1000-grain were among the most influential traits in determining the grain yield, and date of harvest plays an active role in determining the traits of yield. Third harvest date was the best in grain yield, and early harvest before that date would cause loss of yield for all cultivars due to the high grain moisture, and delay after that date would cause a loss of yield as a result of shattering ratio of grain, in addition to difference of cultivars in recording shattering ratio according to harvest date. It can be recommended planting cultivars of Dijlah, Furat 1 and Yasmin, as they achieved the highest yield, and considering the harvest date 14 days after physiological maturity the best date to obtain the highest grain yield.

Growth, Yield, and Phosphorus Efficiency of Safflower Cultivars as Affected by Phosphorus Application in East Azarbaijan Province, Iran

ABSTRACT Identifying the cultivars that efficiently take up and use soil phosphorus (P) can reduce the financial and environmental costs of using P fertilizers. To investigate the growth, yield, and P acquisition efficiency of different cultivars of safflower affected by P deficiency and P applications, this study was conducted as a randomized complete block design in factorial arrangement with three replications in the Tikmeh Dash research station in East Azerbaijan province, Iran in 2016–2017. The studied factors were P fertilization in five levels (0, 10, 20, 30, and 40 kg P ha-1 from Triple superphosphate (TSP)) and safflower cultivars (Padideh and Goldasht). The results showed that under the P deficiency condition, the grain yield of Padideh was about 17% greater than that of Goldasht (1544 vs 1319 kg ha-1). Padideh cultivar was superior to Goldasht in terms of oil percentage (43.2 vs. 40.9%). Grain yield correlated with straw yield (R2 = 0.526**), P concentration (R2 = 0.192**), and the number of fertile capsules (R2 = 0.51**). In general, it is concluded that P concentration in straw is an important factor for grain production in safflower. Although both cultivars showed the greatest benefit-cost ratio of grain and oil yield in the 10 kg ha-1 P treatment, the Padideh cultivar was the superior cultivar. For the conditions of about 7.2 mg kg-1 available Olsen P, the application of 10 kg ha-1 P (50 kg ha-1 TSP) for the Padideh cultivar can be economical.

The Effect of Water Availability on the Carbon Content of Grain and Above- and Belowground Residues in Common and Einkorn Wheat.

The carbon (C) fixed by crops, which is exported with harvest and retained as postharvest residues in a field, is important for calculating the C balance. The aim of this study was to determine the effect of water availability on the C content in whole wheat plants. In a three-year field trial, the weights of grain, straw, chaff, stubble, and roots of two cultivars of winter wheat (Triticum aestivum L.) and one cultivar of einkorn wheat (Triticum monococcum L.) and their carbon contents were determined in water stress, irrigation, and rain-fed control treatments. The water availability, year, and cultivar had a significant influence on the C content in aboveground plant parts, but the effect of water on grain C was weak. The C content decreased with irrigation and increased with drought, but the differences were small (at most, 3.39% in chaff). On average, the C contents of grain, straw, chaff, and roots reached 45.0, 45.7, 42.6, and 34.9%, respectively. The amount of C exported with grain and left on the field in the form of postharvest residues depended on the weight of the total biomass and the ratio of grain to straw and residue. Whole plant C yield reached 8.99, 7.46, and 9.65 t ha-1 in rain-fed control, stressed, and irrigated treatments, respectively, and 8.91, 9.45, and 7.47 t ha-1 in Artix, Butterfly, and Rumona, respectively. Irrigation significantly increased the C content in grain and straw (but not in chaff, stubble, and roots) in comparison with water shortage conditions. On average, a grain yield of 1 t ha-1 corresponded to an average export of 0.447-0.454 t C ha-1 in the grain of all cultivars and inputs of 0.721, 0.832, and 2.207 t C ha-1 of residue to the soil in the form of straw and postharvest residue in the two cultivars of common wheat and one of einkorn. The results of the study provided reliable data for the calculation of the C balance of wheat under conditions of different water availability.

SHALLOW AND COMBINED TILLAGE OF BLACK SOIL TYPICAL AT DIFFERENT SPECIALISATION IN AGRICULTURAL PRODUCTION IN THE LEFT BANK FOREST STEPPE OF UKRAINE

The article presents the results of long-term experimental studies on the effect of different methods of main tillage on soil fertility and crop productivity when applying different degrees of fertilization. Field research was conducted during 2013-2020 on the lands of the Poltava Research Station of the Institute of Pig Breeding and Agro-Industrial Production of the National Academy of Agricultural Sciences. It has been established that the systematic use of organic and organic and-mineral fertilization systems improves the nutrient regime of typical black soil with differentiation of the arable layer by the amount of phosphorus and potassium when applying long-term minimal loosening. There is a tendency towards an increase in density in the layers of 20-40 and 40-60 cm when applying systematic shallow tillage, where this indicator exceeds the upper limit of the optimal range of 1,0-1,3 g/cm3. Application of manure and mineral fertilizers compared to surface loosening makes it possible to additionally annually sequester 0,3-0,4 t/ha of carbon, which is equivalent to 1,2-1,6 t of carbon dioxide. By the average multi-year yield of corn per silage, shallow loosening is inferior to combined tillage by an average of 10%. Tendencies to a decrease in the average long-term productivity of soybean, spring barley, and pea crops when using minimal tillage compared to the combined one are manifested only in certain fertilizer options. Under optimal conditions of heat and moisture supply, the ratio of grain and straw in soybeans decreases. On winter wheat, after peas, there is a tendency towards the preference of shallow loosening. The ratio of wheat grain to straw increases significantly under favorable conditions. Corn responds better to the combined tillage system, which prevails shallow loosening in terms of grain yield by the fertilizer options by 6-10%. Under favorable conditions, the ratio of stems to grain increases significantly, especially on fertilized grounds. From the studied crops, the productivity of sugar beets fluctuates to a greater extent to the conditions of the year, and to a lesser extent - winter wheat, grown after peas and corn for grain. By the average long-term crop productivity, shallow tillage is inferior to combined tillage by 4-8% having a confidence level of 5%. When applying manure, it is advisable to use a combined system of soil tillage, for plant-oriented agrarian production, it is economically advisable to use surface loosening for all crops.

The Impact of Production Techniques on the Physicochemical Properties, Microbiological, and Consumer’s Acceptance of Milk and Water Kefir Grain-Based Beverages

The increasing focus on a healthy lifestyle has emphasized a connection between gut microbiome and health. Consumers face the choice between consuming traditional dairy kefirs or more trendy fruit-based fermented drinks. Also, the aim of this study is to determine the similarities and differences theoretically and experimentally based on a higher ratio of grains to make a lower pH-based beverage at different inoculation times and durations. This study also aims to assess acceptability from a sensory perspective. The goal of the research was to make kefir grain-based beverages with a higher number of lactic acid bacteria (LAB) owing to their probiotic impact on the human gut. After analysis, it was found that there was the highest content of LAB in water kefir after 48 h of inoculation. However, consumer acceptance tests found traditional dairy kefir with a 24-h inoculation to be more acceptable. Although both drinks were inoculated in a 1:4 ratio, it is important to note the variations in grain origin as well as the initial composition of the milk–water suspension, which significantly affects the final product. Since the recipe of the kefir determines the benefits of the drink, the onus is on the consumers to decide which fermented drink suits their health condition best.

Differences in Ratio of Carbon Stable Isotopes among Barley Grain Milling Fractions with Various Concentrations of Beta-Glucans.

The grains of three barley varieties were milled and sieved to obtain respective milling fractions with a content of beta-glucans (b-G) from 1.4 to 10.7%. The enriched fraction obtained by the extraction and precipitation contained 24.7% of b-G. The differences between the ratio of stable C carbon isotopes were established. Milling fractions with coarse particles had more beta-glucans and a more negative ratio of δ13C isotope in comparison to the respective intact barley grain. However, the enriched fraction had a less negative isotope ratio. So, it is not expected that the deviation from the stable isotope ratio of grain in milling fractions is the result of the content of b-G, but it depends on other barley grain constituents. In different parts of barley grain, there are substances with different stable isotope ratios, and by milling and sieving, they are assorted to the same milling fraction with most of the b-G. The method for determining the ratio of a stable carbon isotope in diverse barley grain fractions, applied in this investigation, is potentially opening the possibility for an additional method of screening the concentration of bioactive constituents in barley grain.

Enhanced thermal conductivity of Si3N4 ceramics through pyrolytic carbon prepared by gel casting using DMAA

To reduce the lattice oxygen content of Si3N4 green bodies, samples were prepared using an N,N-dimethylacrylamide (DMAA) system. The endothermic and exothermic peaks are related to the decomposition of organic matter and the reaction between pyrolytic carbon and impurity oxides in the sintering process. Multi-step heat preservation during the thermal degreasing process reduced the carbon content and defects. The α→β phase transformation and aspect ratio of grains changed from 89.2% to 4.84:1 at 1640 °C to 96.3% and 7.80:1 at 1700 °C, respectively. The relative density, hardness, fracture toughness, and thermal conductivity of the Si3N4 samples reached 98.5%, 1353 HV, 8.51 MPa·m1/2, and 97.1 W·m−1·K−1, respectively. Pyrolytic carbon can react with SiO2, which reduces the content of the glass phase in the green body and affects the dissolution and precipitation process and lattice oxygen content. In the structure of the Si3N4 sample, carbon particles with sizes of 100–500 nm and near-spherical shapes were observed. Intergranular-phase YMgSi2O5N was formed during the sintering process, which was conducive to improving the thermal conductivity. This article uses lower temperature and no pressure conditions to prepare Si3N4 ceramics, which can provide reference for batch and low-cost production.

Analysis of the error of influencing factors on the result of measuring the moisture content of grain and grain products

The potential to utilize an ultrahigh-frequency method to regulate the humidity of grain and the products of their industrial processing, allowing one to use this method to regulate technological processes in the production environments of grain-processing industries by controlling the material under examination in free space and converting the measured parameters of the electromagnetic wave passed through the material into an electrical signal. The developed functional scheme of the experimental setup based on the ultrahigh-frequency method of dependence of attenuation and phase shift of electromagnetic wave on the volumetric density of wheat grain at different mass fraction of humidity is discussed, it is shown that with increasing volumetric density at a constant value of the mass fraction of moisture decreases the error of grain moisture measurement with increasing volumetric density, where the main component of the total error of the ultrahigh frequency method (amplitude and phase) is associated with the influence of interfering factors and depends mainly on the variable thickness and density of the controlled material. In order to reduce the components of measurement error brought on by various non-informative (interfering factors) parameters on the outcome of measuring the mass moisture ratio of grain and grain products, the method of moisture measurement in both discrete and inline manufacturing is investigated.

Effective medium method in solution of the elastic and thermo-elastic homogenization problems for polycrystals with spheroidal transverse isotropic grains

Self-consistent effective medium method is used for determination of the effective elastic and thermo-elastic properties of polycrystalline materials with spheroidal transverse isotropic grains. The grains with arbitrary aspect ratios including very oblate (disks) and very prolate (fibers) spheroids are considered. The function of the Owens-March type is used for description of distribution of grains over orientations. The equations for the effective elastic stiffness tensor and the tensor of effective coefficients of thermo-expansion of polycrystals are derived using integral equations for elastic and thermo-elastic fields in heterogeneous media and the hypotheses of the effective medium method. The numerical algorithm of the method is described in detail. Numerical examples are presented for polycrystalline clay rock materials with strongly anisotropic grains and for polycrystalline zinc. Graphs of the dependences of the effective elastic constants and effective coefficients of thermo-expansion of the polycrystals on the parameters of the orientation distribution function and aspect ratios of grains are presented.

Effects of Microbial Inoculants and Organic Amendments on Wheat Nutrition and Development in a Variety of Soils

Manipulation of soil microbial communities through inoculants or amendments can improve crop nutrition. However, to what extent these benefits vary depending on soil properties is not yet understood. Thus, here we studied the effects of microbial inoculants and the application of labile organic C on the yield and uptake of micronutrients and P in wheat (Triticum durum) in different soils. The application of Bacillus subtilis QST713, Trichoderma asperellum strain T34, and cellulose was tested in ten soils varying greatly in properties in a pot experiment. Microbial inoculants and cellulose increased dry matter (between 5 and 10%) and grain yield (between 15 and 20%), regardless of the soil. Some treatments triggered nutrient mobilization mechanisms such as phosphatase and oxalate production. However, total Zn and P in plants did not increase with treatments, and their effect on Fe and Mn varied depending on soils. The effect of B. subtilis and T. asperellum improving Fe uptake by plants decreased with increasing pH and also with decreased microbial activity in soil. Inoculants and cellulose increased the Zn harvest index and decreased the P-to-Zn ratio in grains independently of the soil. This was probably ascribable to changes in the distribution of phytohormones in plants. Microorganisms and cellulose improved wheat yield, the portion of absorbed Zn accumulated in grains, and grain quality. These effects did not depend on the soil. However, the effect on Fe and Mn nutrition was affected by soil pH and microbial activity.

Fermentation of increasing ratios of grain starch and straw fiber: effects on hydrogen allocation and methanogenesis through in vitro ruminal batch culture.

Grain starch has a faster rate of rumen fermentation than straw fiber and causes a rapid increase in ruminal molecular hydrogen (H2) partial pressure, which may promote other H2 sinks to compete H2 away from methanogenesis. The study was designed to investigate the effects of increasing ratios of grain starch to straw fiber on hydrogen allocation and methanogenesis through in vitro ruminal batch incubation. Corn grain and corn straw were employed as starch and fiber source respectively. Seven treatments were the ratios of corn grain to corn straw (RGS) being 0:6, 1:5, 2:4, 3:3, 4:2, 5:1, and 6:0. Elevating RGS increased dry matter (DM) degradation and decreased methane (CH4) and hydrogen gas (gH2) production relative to DM degraded. Elevating RGS increased volatile fatty acid (VFA) concentration, propionate molar percentage and microbial protein (MCP) concentration, decreased acetate molar percentage, acetate to propionate ratio and estimated net metabolic hydrogen ([H]) production relative to DM degraded. Elevating RGS decreased the molar percentage of [H] utilized for CH4 and gH2 production. In summary, increasing ratios of grain starch to straw fiber altered rumen fermentation pathway from acetate to propionate production, reduced the efficiency of [H] production with the enhancement of MCP synthesis, and led to a reduction in the efficiency of CH4 and gH2 production.

Could effective fracture toughness of polycrystalline aggregates exceed inner grain fracture toughness by adjusting toughness of grain boundary?

Obtaining intergranular and transgranular fractures through grain boundary engineering has been considered an efficient technique that improves the effective fracture toughness of polycrystalline aggregates. In this paper, the idealized hexagonal microstructure, random microstructures, and microstructures of grains with large aspect ratios are analyzed through a semi-analytical approach and the cohesive finite element method. The results indicate that when the aspect ratio of grains is not too large, the crack paths consisting of intergranular and transgranular fractures are approximately Mode I fracture morphologies among these microstructures. As the ratio of toughness between grain boundaries and grains varies, the effective fracture toughness of the microstructure can be increased more than the grain boundary fracture toughness but cannot exceed the inner grain fracture toughness.In contrast, the microstructure of grains with a large aspect ratio leads to deflected crack paths that are unexpectedly obtained, which implies that the approximate Mode-I intergranular fracture along transverse direction is almost impossible. The results demonstrate that the projected energy dissipation rate along the direction perpendicular to the loading axis can be significantly improved beyond the inner grain fracture toughness by enlarging the aspect ratio of the grains. Nevertheless, the mixed-mode effective fracture toughness is still limited to the grain fracture toughness. Corresponding experiments are also carried out to qualitatively verify the numerical results. The underlying mechanism for this deflection of fracture path is due to the strong anisotropy of fracture toughness. The higher the grain aspect ratio, the greater the anisotropy of the macroscopic effective fracture toughness. The energy favored fracture path is determined by the largest ratio between the driving force and the toughness of fracture over all directions. Therefore, cracks cannot propagate in the direction of the maximum fracture toughness when the aspect ratio of the grain is sufficiently large. The fracture diagrams that vary with the aspect ratio of grain and the ratio of fracture toughness between the grain and grain boundary are provided. The results can provide valuable guidance for designing microstructures and improving fracture toughness in materials.