Analytical Investigation of Projectile Motion in Midair

Here is studied a classic problem of the motion of a projectile thrown at an angle to the horizon. The air drag force is taken into account as the quadratic resistance law. An analytic approach is used for the investigation. Equations of the projectile motion are solved analytically. All the basic functional dependencies of the problem are described by elementary functions. There is no need for to study the problem numerically. The found analytical solutions are highly accurate over a wide range of parameters. The motion of a baseball and a badminton shuttlecock are presented as examples

Simple analytical algorithm for constructing the envelope of the projectile trajectories in midair

A classic problem of the motion of a projectile thrown at an angle to the horizon is studied. The air drag force is taken into account asthe quadratic resistance law.An analytic approach is used for the investigation. Simple analytical formulae are used for constructing the envelope of the family of the projectile trajectories. The equation of envelope is applied for the determination of the maximum range of flight. The motion of a baseball is presented as an example

Effects of Inert Nanoparticles of High-Melting-Point Compositions on Grain Structure and Strength of Ni[3]Al Intermetallic Compounds

The paper represents experimental findings both in the area of effects of nanoparticles of inert high-melting-point TiN compounds on a Ni[3]Al intermetallic grain structure creation in the conditions of high temperature synthesis under pressure, and in the area of impact of grain structure modification on intermetallic compounds' strength factor temperature dependence. It was demonstrated that appending a stoichiometric composition of nanosized particles of high-melting-point inert chemical compounds (TiN) initiates a manyfold loss of average size of grain of Ni[3]Al intermetallic compounds, synthesized under pressure, as well as a sufficient intermetallic compounds' strength rise within a wide range of temperatures (up to 1 000 degree C). Electron-microscopic evaluations of a synthesized intermetallic structure with TiN nanoparticles, showed that, during the process of intermetallic polycrystalline structure creation from high temperature synthesis products melts, TiN nanoparticles are mainly spread throughout the boundaries and joints of grain structure, acting as stoppers of grain boundaries migration

Yield and Quality in Purple-Grained Wheat Isogenic Lines

Breeding programs for purple wheat are underway in many countries but there is a lack of information on the effects of Pp (purple pericarp) genes on agronomic and quality traits in variable environments and along the product chain (grain-flour-bread). This study was based on unique material: two pairs of isogenic lines in a spring wheat cv. Saratovskaya-29 (S29) background differing only in Pp genes and grain color. In 2017, seven experiments were conducted in Kazakhstan, Russia, and Turkey with a focus on genotype and environment interaction and, in 2018, one experiment in Turkey with a focus on grain, flour, and bread quality. The eect of environment was greater compared to genotype for the productivity and quality traits studied. Nevertheless, several important traits, such as grain color and anthocyanin content, are closely controlled by genotype, offering the opportunity for selection. Phenolic content in purple-grained lines was not significantly higher in whole wheat flour than in red-colored lines. However, this trait was significantly higher in bread. For antioxidant activities, no differences between the genotypes were detected in both experiments. Comparison of two sources of Pp genes demonstrated that the lines originating from cv. Purple Feed had substantially improved productivity and quality traits compared to those from cv. Purple

Structural mechanisms of formation of adiabatic shear bands

The paper focuses on the experimental and theoretical study of plastic deformation instability and localization in materials subjected to dynamic loading and high-velocity perforation. We investigate the behavior of samples dynamically loaded during Hopkinson-Kolsky pressure bar tests in a regime close to simple shear conditions. Experiments were carried out using samples of a special shape and appropriate test rigging, which allowed us to realize a plane strain state. Also, the shear-compression specimens proposed in were investigated. The lateral surface of the samples was investigated in a real-time mode with the aid of a high-speed infra-red camera CEDIP Silver 450M. The temperature field distribution obtained at different time made it possible to trace the evolution of plastic strain localization. Use of a transmission electron microscope for studying the surface of samples showed that in the regions of strain localization there are parts taking the shape of bands and honeycomb structure in the deformed layer. The process of target perforation involving plug formation and ejection was investigated using a high-speed infra-red camera. A specially designed ballistic set-up for studying perforation was used to test samples in different impulse loading regimes followed by plastic flow instability and plug ejection. Changes in the velocity of the rear surface at different time of plug ejection were analyzed by Doppler interferometry techniques. The microstructure of tested samples was analyzed using an optical interferometer-profilometer and a scanning electron microscope. The subsequent processing of 3D deformation relief data enabled estimation of the distribution of plastic strain gradients at different time of plug formation and ejection. It has been found that in strain localization areas the subgrains are elongated taking the shape of bands and undergo fragmentation leading to the formation of super-microcrystalline structure, in which the size of grains is ~300nm. Rotational deformation modes give rise to the high angular disorientations of grains. The development of plastic shear instability regions has been simulated numerically. For this purpose, we use a recently developed theory, in which the influence of microshears on the deformation properties of materials has been studied by the methods of statistical physics and thermodynamics of irreversible processes. The results of theoretical and experimental studies suggest that one of the mechanisms of the plastic shear instability and localization of plastic strain at high-velocity perforation is related to structural and kinetic transitions in microshear ensembles.&nbsp

Atom mechanisms of primary processes during radiation impact on solid body

Materials with side-centred structure, body-centred structure, hexagonal structure and A-15 structure under radiation were investigated with the aim of study of the impact of the peculiarities of forces of interatom interaction and with the aim of prediction of behaviour of materials with different structure under radiation. As a result the decisive role of peculiarities of forces of interatom interaction under various kinds of radiation impact and various temperatures which cause the main differencies in radiation-stimulated properties was shown. The results obtained may find their field of application in the development of construction materials which are serviceable under radiation of high intensityAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

Novel QTL Hotspots for Barley Flowering Time, Plant Architecture, and Grain Yield

Barley (Hordeum vulgare L.) is one of the oldest cultivated grains and remains a significant crop globally. Barley breeders focus on developing high-yield cultivars resistant to biotic and abiotic stresses. Barley’s flowering time, regulated genetically and by environmental stimuli, significantly impacts all of its agronomic traits, including the grain yield and plant architecture. This study aimed to detect the quantitative trait loci (QTLs) affecting these traits in 273 two-row spring barley accessions from the USA, Kazakhstan, Europe, and the Middle East across two regions of Kazakhstan, evaluating their impact on grain yield. Genotypic data were obtained from 26,529 segregating single-nucleotide polymorphisms (SNPs), and field trial data for 273 accessions, which were obtained for six traits (heading time, maturity time, vegetation period, plant height, peduncle length, and grain yield) in two regions of Kazakhstan over three growth years. As a result of a genome-wide association study (GWAS), 95 QTLs were identified for 6 agronomic traits, including 58 QTLs linked with candidate genes and/or QTLs. The remaining 37 QTLs were putatively novel, with 13 of them forming 3 QTL hotspots on chromosomes 1H (5 QTLs in the interval of 13.4–41.4 Mbp), 3H (4 QTLs in 608.6–624.9 Mbp), and 6H (4 QTLs in 553.8–572.8 Mbp). These hotspots were pleiotropic, and targeting these regions would allow breeders to enhance multiple yield-associated traits

QTL mapping of agronomic traits in wheat using the UK Avalon × Cadenza reference mapping population grown in Kazakhstan

Background The success of wheat production is largely dependent on local breeding projects that focus on the development of high-yielding cultivars with the use of novel molecular tools. One strategy for improving wheat productivity involves the deployment of diverse germplasms with a high potential yield. An important factor for achieving success involves the dissection of quantitative trait loci (QTLs) for complex agronomic traits, such as grain yield components, in targeted environments for wheat growth. Methods In this study, we tested the United Kingdom (UK) spring set of the doubled haploid (DH) reference population derived from the cross between two British cultivars, Avalon (winter wheat) and Cadenza (spring wheat), in the Northern, Central, and Southern regions (Karabalyk, Karaganda, Kyzylorda) of Kazakhstan over three years (2013–2015). The DH population has previously been genotyped by UK scientists using 3647 polymorphic DNA markers. The list of tested traits includes the heading time, seed maturation time, plant height, spike length, productive tillering, number of kernels per spike, number of kernels per meter, thousand kernel weight, and yield per square meter. Windows QTL Cartographer was applied for QTL mapping using the composite interval mapping method. Results In total, 83 out of 232 QTLs were identified as stable QTLs from at least two environments. A literature survey suggests that 40 QTLs had previously been reported elsewhere, indicating that this study identified 43 QTLs that are presumably novel marker-trait associations (MTA) for these environments. Hence, the phenotyping of the DH population in new environments led to the discovery of novel MTAs. The identified SNP markers associated with agronomic traits in the DH population could be successfully used in local Kazakh breeding projects for the improvement of wheat productivity

Identification of SNP Markers Associated with Grain Quality Traits in a Barley Collection (Hordeum vulgare L.) Harvested in Kazakhstan

Barley (Hordeum vulgare L.) is a cereal crop traditionally used in animal feed, malting, and food production. In this study, a collection of barley was analyzed according to key grain quality traits, including protein content (GPC), starch content (GSC), extractivity (EX), and grain test weight per liter (TWL). A genome-wide association study (GWAS) was conducted to identify the quantitative trait loci (QTLs) associated with GPC, GSC, EX, and TWL using a collection of 658 barley accessions from the USA and Kazakhstan. The collection was grown at three breeding organizations in Kazakhstan in 2010 and 2011 and genotyped using the 9K SNP Illumina chip. As a result, 18 marker-trait associations (MTAs) for GPC, 19 MTAs for GSC, 12 MTAs for EX, and 27 MTAs for TWL were detected, resulting in 30 identified QTLs. It was shown that the genetic locations of 25 of these 30 QTLs were in similar positions to the QTLs and genes previously reported in the scientific literature, suggesting that the 5 remaining QTLs are novel putative genetic factors for the studied grain quality traits. Five of the most significant SNP markers (p < 2.6 × 10−5) for the studied quality traits identified in the GWAS were used for the development of reliable and informative competitive allele-specific PCR (KASP) genotyping assays. The effectiveness of two assays (ipbb_hv_6 and ipbb_hv_128) was confirmed via validation in a separate collection of barley breeding lines grown in large field plots in northern Kazakhstan. Therefore, these KASP assays can be efficiently used in a marker-assisted selection of grain quality traits in barley breeding