Characteristics Of Grains Research Articles

Redox kinetics of nickel oxide foils: Structural evolution and rate-limiting steps

We examine the redox activity of nickel/nickel oxide foils. Thin nickel foils (2.5 µm, 10 µm, and 100 µm) were subjected to redox conditions in a fixed-bed reactor within 800–1000 °C, and samples were examined using SEM at different stages of conversion. We identify some key features or the process that are used to guide model development: (1) Oxidation starts with the nucleation of oxide grains, followed by their rapid growth leading to overlap and the attenuation of fast diffusion pathways. (2) Reduction is impacted by the evolution of macro-pores which facilitate gas-oxide contact, and dense metallic clusters that shield the reactants. (3) The transitions between stages during conversion and the characteristics of grains, pores and clusters depend on the sample thickness. Guided by these observations, analytical models are formulated. Oxidation is modeled as a nucleation nucleation-growth process while reduction is characterized by an adsorption-surface reaction process. We extract the corresponding reaction parameters by training the model using the measurements and show that the model formulation captures the controlling mechanisms of the conversion. The oxidation rate is controlled by the rapid decay of oxygen transport across the products layer, and the dependency of the oxides grain structure on the sample thickness contributes to the rate of decay. The reduction rate is largely controlled by the accessibility of lattice oxygen to surface kinetics, and mostly by slow ionic diffusion. While using different foil thicknesses is useful in extracting the kinetics, if used in rapid redox processes applicable to chemical-looping applications, oxygen carriers (foils or other forms) with characteristic active metal thickness of ∼1 µm are recommended.

METHODS OF INFRASTRUCTURE MANAGEMENT FOR OPTIMIZATION OF GRAIN TRANSPORT ORGANIZATION

The analysis of the railway freight sector in recent years has set a clear trend towards the development of the oil and grain goods transportation. The growth dynamics in the agrarian sector is positive with a growing sum due to the technological development of the industry and the demand for the world market. Taking into account the geographical, normative and legal component of the agricultural transport sector, the railway becomes a key player in this direction. Paying attention to it and to the particular features of grain and oil cargo exports, the industry must meet modern criteria of service and service quality. Due to lack of locomotive traction, lack of a proper investment market, there is a problem of introducing relevant innovations in the formation of the grain cargoes exports logistics. For the last freight year, the price of domestic corn on the world market, according to the expert estimates, was 18 % lower than the world average. Separately, there is a question of forming the wagon shipments of this group of goods. The analysis of the loading capacity of the eastern Ukrainian stations by grain goods at the end of 2018 clearly demonstrates the railways inability to provide the transportation demand for the whole number of shippers with small and medium cargo volumes. This situation creates accumulating and freezing of funds, that makes it impossible to develop the entire business sector and gives a negative assessment of the industry as a whole in the conditions of its investment necessity. The model is developed and the basic principles of forming the stage routes and organizing the movement of grain cargoes are defined. The main trends of the grain cargoes market development are analyzed and key market factors that allow to have a short-term forecast on the transportation tendency are revealed. The model of forming the stage route with the peculiarities of the traction apparatus work of the division and the principle of rolling stock distribution in terms of industry restructuring are proposed.

Effect of grain size on α-variant selection in a ZrTiAlV alloy

Local crystallographic orientation characteristics of grains with different sizes in a ZrTiAlV alloy after interrupted cooling from β phase region are investigated by electron backscatter diffraction (EBSD) technique. A statistical analysis of EBSD data shows that bigger parent β grains present weaker variant selection than smaller grains. The relevant influences are studied by comparing the nucleation behavior of grain boundary α (GBα) and succedent growth stage in varisized grains. In-depth analysis indicates that the deviation between pole of GBα and common pole of adjacent parent β grains is responsible for the smaller degree of variant selection inside the bigger parent β grains. The formation of more than one GBα type at the β/β grain boundary with common pole in bigger grains results in obstructing each other for these variants during the following growth stage, while only one type of GBα nucleate at the β/β grain boundary with common pole in smaller grains and it can freely grow into the interior of the grains, leading to stronger variant selection in smaller β grains.

μCT trait analysis reveals morphometric differences between domesticated temperate small grain cereals and their wild relatives.

SummaryWheat and barley are two of the founder crops domesticated in the Fertile Crescent, and currently represent crops of major economic importance in temperate regions. Due to impacts on yield, quality and end‐use, grain morphometric traits remain an important goal for modern breeding programmes and are believed to have been selected for by human populations. To directly and accurately assess the three‐dimensional (3D) characteristics of grains, we combine X‐ray microcomputed tomography (μCT) imaging techniques with bespoke image analysis tools and mathematical modelling to investigate how grain size and shape vary across wild and domesticated wheat and barley. We find that grain depth and, to a lesser extent, width are major drivers of shape change and that these traits are still relatively plastic in modern bread wheat varieties. Significant changes in grain depth are also observed to be associated with differences in ploidy. Finally, we present a model that can accurately predict the wild or domesticated status of a grain from a given taxa based on the relationship between three morphometric parameters (length, width and depth) and suggest its general applicability to both archaeological identification studies and breeding programmes.

ИЗУЧЕНИЕ ИЗМЕНЧИВОСТИ СОРТОВ РИСА ПО АМИЛОГРАФИЧЕСКИМ ХАРАКТЕРИСТИКАМ КРАХМАЛА ЗЕРНА В СВЯЗИ С ИСПОЛЬЗОВАНИЕМ РАЗЛИЧНЫХ ДОЗ АЗОТНЫХ УДОБРЕНИЙ ПРИ ВОЗДЕЛЫВАНИИ

ИЗУЧЕНИЕ ИЗМЕНЧИВОСТИ СОРТОВ РИСА ПО АМИЛОГРАФИЧЕСКИМ ХАРАКТЕРИСТИКАМ КРАХМАЛА ЗЕРНА В СВЯЗИ С ИСПОЛЬЗОВАНИЕМ РАЗЛИЧНЫХ ДОЗ АЗОТНЫХ УДОБРЕНИЙ ПРИ ВОЗДЕЛЫВАНИИ

Increased rate of potassium fertilizer at the time of heading enhances the quality of direct seeded rice

BackgroundPotassium (K) is not easily assimilated into organic matter but helps to improve rice quality. Paddy yield and its quality depend on the correct time of fertilization and harvesting (days after flowering) in the field.MethodsChanges in the grain quality of (Oryza sativa L.) were studied in a field experiment over two dry seasons using three rates of muriate of potash (MOP; 60% K2O) as 12.5, 25 and 37.5 kg/ha applied at the time of heading (7 weeks after planting—WAP). Paddy samples were harvested during 25, 30 (control), 35 and 40 days after 50% flowering (DAFF). Grain yield and physico-chemical characteristics of grain were studied after harvesting.ResultsThe impact of seasons and treatments’ interactions was not statistically significant (P > 0.05) and, hence, data were averaged over two seasons. Length, breadth, true density and bulk density of rice grains were the highest with 37.5 kg MOP/ha applied at heading and harvested at 30–35 DAFF. Crude protein (6.24%) and crude fat (2.61%) contents in grains were the highest when harvested at 40 DAFF and 35–40 DAFF, respectively. Amylose content decreased with increased MOP rates at the time of heading and delayed paddy harvest. The highest average paddy yield (APY; 6.85 t/ha), head rice yield (HRY; 65%) and total rice milling yield (TMY; 67%) were recorded with 37.5 kg MOP/ha applied at heading of rice plant and paddy harvested at 35 DAFF. The APY, HRY and TMY were also 13.8, 7.7 and 5.9% higher, respectively, compared to the control. Applying K fertilizer at a rate 50% more (18.75 kg K/ha) than the recommended rate at the time of heading (7 WAP) and harvesting paddy at optimum maturity (35 DAFF), which is 5 days later than the recommendation, increase the yield and grain quality of direct seeded rice. Harvesting later than 35 DAFF resulted in a 10.5% loss of HRY (P < 0.05).ConclusionsThe present study showed that K fertilizer applied at the rate of 37.5 kg MOP/ha at the time of heading 50% higher than the recommended rate is the best among K fertilizer treatments to obtain the highest HRY.

Treatment of corn with lactic acid or hydrochloric acid modulates the rumen and plasma metabolic profiles as well as inflammatory responses in beef steers

BackgroundHigh-grain diets that meet the energy requirements of high-producing ruminants are associated with a high risk of rumen disorders. Mild acid treatment with lactic acid (LA) has been used to modify the degradable characteristics of grains to improve the negative effects of high-grain diets. However, the related studies mainly focused on dairy cows and explored the effects on rumen fermentation, production performance, ruminal pH and so forth. And up to date, no studies have reported the hydrochloric acid (HA) treatment of grains for ruminant animals. Therefore, based on metabolomics analysis, the aim of this study was to evaluate the effects of treatment of corn by steeping in 1% LA or 1% HA for 48 h on the rumen and plasma metabolic profiles in beef steers fed a high corn (48.76%) diet with a 60:40 ratio of concentrate to roughage. The inflammatory responses of beef cattle fed LA- and HA-treated corn were also investigated.ResultsBased on ultra-high-performance liquid tandem chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF/MS) metabolomics and multivariate analyses, this study showed that steeping corn in 1% LA or 1% HA modulated the metabolic profiles of the rumen. Feeding beef steers corn steeped in 1% LA or 1% HA was associated with lower relative abundance of carbohydrate metabolites, amino acid metabolites, xanthine, uracil and DL-lactate in the rumen; with higher ruminal pH; with lower concentrations of acetate, iso-butyrate and iso-valerate; and with a tendency for lower ruminal lipopolysaccharide (LPS) concentrations. Moreover, the data showed lower concentrations of plasma C-reactive protein, serum amyloid A, haptoglobin, interleukin (IL)-1β and IL-8 in beef steers fed 1% LA- or HA-treated corn. The 1% LA treatment decreased the concentrations of plasma LPS, LPS-binding protein and tumour necrosis factor-alpha and the relative abundance of L-phenylalanine, DL-3-phenyllactic acid and tyramine in plasma. The 1% HA treatment decreased the relative abundance of urea in plasma and increased the relative abundance of all amino acids in the plasma.ConclusionsThese findings indicated that LA or HA treatment of corn modulated the degradation characteristics of starch, which contributed to improving the rumen and plasma metabolic profiles and to decreasing inflammatory responses in beef steers fed a high-concentrate diet.

Synergistic Effect of Sulfur and Nitrogen in the Organic and Mineral Fertilization of Durum Wheat: Grain Yield and Quality Traits in the Mediterranean Environment

In recent years, awareness on sustainable land use has increased. Optimizing the practice of nitrogen fertilization has become crucially imperative in cropping management as a result of this current trend. The effort to improve the availability of organic nitrogen has incurred a bottleneck while seeking to achieve a high yield and quality performance for organic winter cereals. Field experiments were conducted, under rainfed Mediterranean conditions, over a period of two subsequent growing seasons. The objective was to investigate the effect of soil and foliar S application on the performance of three durum wheat cultivars fertilized with either organic or inorganic N. The hypothesis to be verified was if different S fertilization strategies could improve grain yield and quality when coupled with mineral or organic N fertilizer. There were three levels of treatment with mineral N fertilizer (120, 160 and 200 kg ha−1), two levels of organic N fertilizer (160 and 200 kg ha−1), two levels of S fertilizer applied to the soil (0 and 70 kg ha−1), and two levels of foliar S application at flag leaf stage (0 and 5 kg ha−1). Cultivars were Dylan, Iride and Saragolla. Analyzed traits were grain yield, yield components and quality features of grain. Overall, at the same N rate, grain yield and quality were markedly higher for mineral than organic N source. Cultivar × Year × N treatment interactions significantly affected grain yield and quality indices. Iride showed a high yield stability throughout the mineral N rates in the most favorable year (2011) and, in the same year, was the top performing cultivar in organic N treatments. Dylan was the top performing cultivar for protein content, while Saragolla for the SDS sedimentation test. Soil S fertilization had no effect on grain quality, whereas it significantly increased grain yield (+ 300 kg ha−1) when coupled with organic rather than a mineral N source. However, foliar S application at flag leaf stage did not affect grain yield, but it significantly enhanced quality indices such as test weight (81 vs. 79.9 kg hL−1), protein content (13.7% vs. 12.9 %) and SDS value (72.5 vs. 70.5 mm). A rate of 160 kg ha−1 of N (both mineral and organic) determined the optimal response for both grain yield and quality. Finally, soil and foliar application of S may help to contain the large yield and quality gap that still exists between mineral and organic fertilization of durum wheat.

Pre-harvest sprouting resistance of soft winter wheat varieties and associated grain characteristics

The varietal differences in pre-harvest sprouting (PHS) resistance and associated grain characteristics have yet to be understood. We tested the grains of 125–166 soft winter (SW) wheat varieties grown for three years for falling number (FN), α-amylase activity, and degree of sprouting (DS) under field sprouting (FS) and spike wetting conditions, and determined the characteristics of grain produced under non-FS conditions for two years. Eleven to 31 varieties exhibited FNs higher than 200 under spike wetting conditions, and 16 to 99 varieties exhibited FNs above 300 under FS conditions. Red wheat varieties showed significantly (p < 0.05) higher FNs than soft white wheat varieties for the grains produced under FS conditions in 2015 and 2017 and subjected to spike wetting in 2017. Awned varieties showed significantly (p < 0.05) lower FNs and higher DS values than awnless varieties when subjected to spike wetting in 2016. Falling number, α-amylase activity, and DS of grain produced under FS in 2015, 2016 and 2017 exhibited significant correlations with test weight (TW) (p < 0.01) of grain produced under non-FS conditions in 2016 and 2017. Five awnless red wheat varieties exhibited relatively high FNs, even under FS and spike wetting conditions.

Prediction of apparent metabolizable energy and metabolizable energy corrected for nitrogen of corn according to physical classification of the grain

ABSTRACT The objective of this study was to develop an equation to determine the apparent metabolizable energy (AME) and metabolizable energy corrected for nitrogen balance (AMEn) using a physical-based classification of corn. A total of 5,055 samples were taken from bulk cargo trucks, over a five-year period. The parameters studied were the variables related to the physical characteristics of grains. The density of maize was evaluated, and AME and AMEn were calculated. The average value for AME was 3,375 kcal/kg, [...]

Numerical study on the inner temperature measurement for the target in CiADS

Abstract The gravity-driven dense granular target (DGT) was proposed as a new concept for a high-power spallation target in China initiative Accelerator Driven System (CiADS). A DGT has several attractive features, coexisting with some new challenges such as the inner temperature measurement for the target. It has been analyzed and proved that a traditional method cannot be used for the inner temperature measurement. A natural viewpoint is that measuring the temperature by means of the other physical quantities. In this paper, the minimum velocity distribution along the radial direction was firstly gained by investigating the relationship between the velocity and energy deposited in grains. Then, the relationship between the temperature increment and flow rate was studied based on the velocity and flow characteristics of grains in the target. At the same time, the temperature field at a specific flow rate was also studied. The method was finally proved feasible and practical theoretically. The trial of the research thought is new and also suitable for other cases similar with the one in this paper.

Composition, functional components, and physical characteristics of grain from staygreen and senescent sorghum lines grown under variable water availability

AbstractBackground and objectivesThe inclusion of sorghum into human food and feed is limited by its low digestibility compared to corn, due to the presence of high total kafirin levels in sorghum grain. Water stress after pollination reduced grain filling, affecting the grain composition, grain functional components, and grain physical characteristics. Sorghum lines possessing the staygreen trait continue to fill their grain under postflowering water deficit. Understanding the environmental effect on the grain nutritional composition and grain physical characteristics of staygreen and senescent sorghum lines will be critical for breeders when selecting traits. This research evaluated a diverse group of staygreen and senescent sorghum lines subjected to full, preflowering water deficit, and postflowering water deficit irrigations.FindingsStaygreen lines had significantly higher levels of total protein and total kafirin, but lower total starch than senescent types. Higher kafirin level was linked to kernel hardness, and this level increased under water deficit. There were no differences between staygreen and senescent sorghum lines in protein digestibility, fermentation efficiency, kafirin per percent protein, kernel hardness, kernel weight, and kernel diameter irrespective of irrigation treatment.ConclusionsThe nutritional quality and digestibility of sorghum grains were affected by the environment and varies across lines and cultivars. Higher total kafirin level in grains reduces digestibility and impedes energy utilization by interfering with starch digestion. Staygreen lines had significantly higher levels of total protein and total kafirin, but lower total starch than senescent types.Significance and noveltyWith considerable variability in grain digestibility and feeding value among sorghum cultivars, the effect of environments on grain nutritional composition and other quality traits should be considered to match the user's purpose.

Micro-plastic deformation behavior of Al-Zn-Mg-Cu alloy subjected to cryo-cycling treatment

The micro-plastic deformation behavior of Al-Zn-Mg-Cu alloy subjected to cryo-cycling treatment was investigated experimentally in the present work. Micro-plastic deformation was produced by continuous loading-unloading method with applied stress far below the yield strength of this alloy, and the deformation characteristics of grains were detected by Optical Microscope (OM) and Scanning Electron Microscope (SEM). The results showed that cryo-cycling treatment reduced the residual strain (εp) after each cycle of loading-unloading, and the degree of grain deformation was decreased apparently, which indicated that cryo-cycling treatment enhanced the capacity of resistance to micro-plastic deformation. Transmission Electron Microscope (TEM) was employed to reveal the mechanisms of cryo-cycling treatment on Al-Zn-Mg-Cu alloy. The results showed that higher content of homogenous η phases precipitated in the matrix and grain boundaries of Al-Zn-Mg-Cu alloy after cryo-cycling treatment. Meanwhile, no clear precipitate-free zones (PFZs) can be observed in the microstructure of cryo-treated specimen. The changes of microstructure had great contribution to improve the pinning effect of dislocations during micro-plastic deformation. Internal stress was released by the cryo-cycling treatment which was demonstrated by the in-suit cryogenic X-Ray (XRD) measurement, as a result, the stability of dislocation was improved. Cryo-cycling treatment had no obvious influence on the tensile strength and yield strength of Al-Zn-Mg-Cu alloy, while elongation and fracture toughness were improved by the extent of 7% and 10.3% respectively, compared to those of the untreated specimen.

Effect of particle size on the explosive characteristics of grain (wheat) starch in a closed cylindrical vessel

Wheat starch dust explosion poses a serious threat to food processing and handling industries. This study attempts to show the influence of particle size on some explosive characteristics of wheat starch dust. The maximum pressure, maximum rate of pressure rises, and severity factor index were determined in relation to four different particle sizes of wheat starch dust of 38 µm, 45 µm, 53 µm and 71 µm using the 1.2 L Hartmann explosion tube. The result of proximate and elemental analysis conducted showed the sample has a moisture content of 2.1 %, volatile content of 93.3 % and a calorific value of 15,777.2 J/g. The carbon content of the sample was 40 % and the hydrogen content 6.9 %. The result of the explosive parameter tests showed that the maximum explosion pressure of the wheat starch dust sample increased with decreasing particle size with the highest recorded value of 735 kPa for the particle size of 38 µm.

On Errors in Constructing the Polarization Phase Dependences for Solar System Bodies

In astrophysical studies of Solar System bodies, the measured values of the linear polarization degree Pobs and the position angle of the polarization plane θ are usually considered relative to the plane orthogonal to the scattering plane; and the resulting quantities are designated as Pr and θr, respectively. Parameters of the phase curve of polarization Pr = f(α) serve for determining the physical characteristics of grains composing the regolith surfaces of such bodies as, for example, the Moon, Mercury, asteroids, and planetary satellites, or the polydisperse media, such as cometary comae and tails. In this paper it has been shown that the error in the polarization degree grows $${\sigma _{{P_r}}}$$ due to the error $${\sigma _{{\theta _{obs}}}}$$ in determining the position angle. The interrelations between these errors were obtained, and the conditions, under which the values of the linear polarization degree Pr relative to the orthogonal system can be used to analyze the phase dependences of polarization, were formulated.

Comparative characteristics of grain classifications of soft wheat of Kazakhstan and major grain-producing countries

Soft wheat is one of the most important crops, grown in more than 130 countries. To date, one-fifth of the world's wheat, or about 150 million tons a year, is sold on international markets. In the world trade traditionally dominated by the US, Australia, Canada and Argentina. Kazakhstan, being on the 15th place in the production of wheat grain, is among the first ten exporters - in 2017 the country exported about 8 million tons to the amount of 1.5 billion dollars. USA, then, as potential export opportunities are much higher, as evidenced by annual carryover stocks at 3 million tons. According to experts, considerable differences in the classification of wheat grain used in Kazakhstan and in other countries participating in the grain market and the methods for assessing the technological dignity indicators (TDs) laid down in the classifications are a significant obstacle to increasing the export potential of wheat grains. In view of this, an analysis was made of grain classifications of wheat grains used in the most important grain producing countries, TD indicators were determined, methods for their evaluation, and differences were revealed. It is established that in countries that are stable in the quantitative and qualitative characteristics of grain, an insignificant list of TD indicators is adopted, while they characterize the physical quality and state of the grain, which may indicate a general suitability for grinding. It is determined that in Russia and Kazakhstan, in determining the contamination, such an indicator as dockage is not taken into account. Comparative tests of different methods of sampling and determination of contamination have been carried out, and correlation coefficients have been established between indicators of contamination determined by different methods.

Three-dimensional geometrical and topological characteristics of grains in conventional and grain boundary engineered 316L stainless steel

The three-dimensional microstructures of a conventional 316L stainless steel and the same material after grain boundary (GB) engineering have been measured by serial sectioning coupled with electron backscatter diffraction mapping. While it is well known that GB engineered materials are differentiated from conventional materials because of the proportion of coincidence site lattice boundaries, the size of their twin-related domains, and their reduced random boundary connectivity, this work provides a quantitative comparison of the geometrical and topological characteristics of grains in 316L stainless steel before and after GB engineering. Specifically, the numbers of grain faces, triple lines, and quadruple unions per grain have been measured and compared. In addition, the distributions of grain sizes, surface areas, and grain boundary areas have been measured and compared. The results show that, in many ways, the three-dimensional geometrical and topological characteristics of the grains in the GB engineered and conventional materials are similar. In both materials, the distributions of the geometrical parameters are well represented by a log-normal distribution. Comparatively, the GB engineered microstructure has grains that, on average, have both fewer faces and higher (specific) surface areas that deviate more from an ideal equiaxed shape, but there are several eccentric or non-compact shaped grains that have a huge number of faces and extremely large surface area in the GB engineered material. All of these characteristics are likely to be a result of the increased number of twins in the GB engineered microstructure. These eccentric grains would have a positive influence on increasing the resistance to intergranular degradation.

Effect of the New Plant Growth Biostimulants Based on Amino Acids on Yield and Grain Quality of Winter Wheat.

Field and laboratory experiments were carried out in 2012–2013, aimed at evaluating the influence of new products stimulating plant growth based on amino acids on crop yield, characteristics of grain and content of macro- and micronutrients in winter wheat (Triticum aestivum L.). The tests included two formulations produced in cooperation with INTERMAG Co. (Olkusz, Poland)—AminoPrim and AminoHort, containing 15% and 20% amino acids, respectively, and 0.27% and 2.1% microelements, respectively. Field experiments showed that the application of products based on amino acids influenced the increase of grain yield of winter wheat (5.4% and 11%, respectively, for the application of AminoPrim at a dose 1.0 L/ha and AminoHort at dose 1.25 L/ha) when compared to the control group without biostimulant. Laboratory tests showed an increase of technological characteristics of grain such as ash content, Zeleny sedimentation index and content of protein. The use of the tested preparations at different doses also contributed to the increase of the nutrients content in grains, in particular copper (ranging 31–50%), as well as sodium (35–43%), calcium (4.3–7.9%) and molybdenum (3.9–16%). Biostimulants based on amino acids, tested in the present study, can be recommended for an efficient agricultural production.

Effect of blunt nanocracks on the splitting transformation of grain boundary dislocation piled up at triple junctions

Considering that grain boundary (GB) deformation is a structural element that hinders crack growth and promotes superplastic deformation in nanocrystalline materials (NCMs), a theoretical model is suggested to describe the effect of the blunt pre-nanocracks with surface stress on the splitting transformation of the first head grain boundary dislocation (GBD) within the pile-up at the triple junctions (TJs) of GBs in mechanically loaded NCMs. The analytic solution of the total energy change that characterizes this process of splitting transformation of GBD is derived quantitatively by the complex variable method, and then, the very beginning plastic deformation occurrence near the nanocrack tip is predicted. We theoretically evaluated the influence of the various parameters of blunt pre-nanocracks, such as nanocrack blunting and length, the characteristics of grain and GBs, such as grain size, the number of GBDs, and GB angles, and the surface stress at critical conditions for such a splitting transformation. Further analyses revealed that the positive (negative) surface stress significantly decreases (increases) the energy and obviously influences the critical conditions for splitting transformation. Our study identified the beneficial role of GB defect structure transformation, namely the splitting transformation, in enhancing the ductility and fracture toughness of NCMs. It also lays the foundation for investigating how the microstructures caused by GB deformation affect the novel mechanical properties of NCMs.

Local and Global Granular Mechanical Characteristics of Grain–Structure Interactions

The focus of this work is on systematically understanding the effects of packing density of the sand grains on both the internal and bulk mechanical properties for strip footing interacting with granular soil. The studies are based on particle image velocimetry (PIV) method, coupled with a high resolution imaging camera. This provides valuable new insights on the evolution of slip planes at grain-scale under different fractions of the ultimate load. Furthermore, the PIV based results are compared with finite element method simulations in which the experimentally characterised parameters and constitutive behaviour are fed as an input, and a good level of agreements are obtained. The reported results would serve to the practicing engineers, researchers and graduate students in unravelling the mechanics of granular soil at both local and global levels when they interact with structures. The outcomes would be beneficial not only to the geotechnical engineering community, but also to related disciplines dealing with granular materials such as materials processing, minerals and space exploration.