Initial Material Research Articles

Development of a mathematical model for predicting the quality of semi-smoked sausages made from second-grade beef

The article is devoted to the development of a mathematical model for predicting the quality of semi-smoked sausages from beef of the 2nd grade. The use of meat raw materials below 1st grade in the production of high quality sausages due to enrichment with new natural ingredients represents the relevance of the research. The use of enzymes and buckwheat flour in the production of meat products contributes to the improvement of the quality characteristics of the initial meat raw material, increasing the nutritional and biological value of finished products. The results showed that the addition of the enzyme "Protepsin" intensifies the processes of hydrolysis of proteins of connective tissues of beef, increases the moisture-binding ability of model minced meat. It was found that in model minced meat with the use of enzyme in the amount of pH reaches the optimum value in a shorter time. At addition of buckwheat flour the optimum value of moisture-binding capacity is established. The article shows that increasing the amount of buckwheat flour in the formulation of model minced meat more than 6 % leads to an increase in moisture-binding capacity, but at the same time organoleptic characteristics deteriorate significantly. The results obtained during the experiment showed that the enzyme «Protepsin» can be recommended to improve the functional and technological indicators of minced meat and ready semi-smoked sausages and accelerate the maturation process of raw materials. In this paper the object of the study is model minced beef minced meat of 2 grades, enzyme «Protepsin», buckwheat flour.

Breeding estimation of the winter wheat varieties in the conditions of the southern forest-steppe of Western Siberia

The expansion of winter wheat sowing areas is one of the reserves for increasing grain production in the Siberian region, since the areas under winter wheat is 15–20 % larger than under spring wheat according to productivity and has great potential in using bioclimatic resources of the region. the availability of sources of economically valuable traits and the development of various initial material on their basis is of decisive importance for breeding of new winter wheat varieties and their successful introduction into production. The purpose of the current paper was to find sources of economically valuable traits from the collection of winter wheat varieties of Russian breeding in the conditions of Western Siberia. There has been studied a collection of varieties and lines of winter common wheat of Russian breeding from the institutions of the Rostov region, Stavropol, and Krasnodar Areas. Field and laboratory trials were carried out on the experimental field of the Omsk SAU in the conditions of the southern forest-steppe of Western Siberia in 2020–2022. Sowing was laid in fallow at the generally accepted sowing dates. According to the breeding estimation of the studied samples in the field seasons of 2020–2022 there was a significant correlation between winter resistance of plants and winter wheat productivity (r = 0.59), as well as an inverse correlation between productivity and gluten percentage (r = –0.36), grain ash content (r = –0.73) and sedimentation (r = –0.38). The varieties ‘Barynya’ (North Caucasian FNAC), ‘Gubernator Dona’, ‘Donna’ (Rostov ARC), ‘Don 107’, ‘Nakhodka’ (ARC “Donskoy”) and the line ‘K18918’ (RCG named after P.P. Lukyanenko), characterized by increased winter resistance (6.5–8 points) and productivity (351–384 g/m2) have been recommended as sources in breeding to improve productivity level and stability of winter wheat varieties in the conditions of Western Siberia. The varieties ‘Etnos’, ‘Anka’, ‘Gurt’, ‘Antonina’, ‘Alekseich’ and ‘Duplet’ of Krasnodar breeding with a high protein and gluten percentage (16.1–17.9 % and 35.5–39.3 %), large grain ash content and sedimentation (1.59–1.92 % and 58.0–67.0 ml) can be used as an initial material in breeding to improve the quality of winter wheat grain.

Study on impact performance and optimisation of the CRH380 high-speed train traction converter cooling unit

The reliability of the traction converter, a core component in the power traction system of the CRH380 EMU equipment, is heavily reliant on the performance of its cooling unit. The service life of the cooling unit is primarily impacted by its material performance. In order to investigate the material performance of the cooling unit, an impact model was established by using the finite element method. The stress distribution of the cooling unit, made of different materials, was analysed under various impact loads. The accuracy of the calculation results was verified through experiments. The research results show that stress concentration and cracks were identified in the cooling unit of the initial material when subjected to different impact loads. Consequently, an improvement scheme was proposed, which resulted in reduced deformation of the cooling unit, enhanced damage resistance, and an overall mass reduction of approximately 138 kg. These improvements can effectively increase the service life of the cooling unit. The research findings can serve as a reference for further research and optimisation of cooling unit materials.

Investigation of microstructural evolution and mechanical properties Al13Fe4 produced by casting and spark-plasma sintering

In this paper, the preparation and evolution of the polycrystalline Al13Fe4 microstructure were investigated during the casting and spark plasma sintering process (SPS). Experimental results showed that an increase in the cooling rate (90–100 °C/min) for both methods of synthesis led to the formation of cracks and chips in the bulk of the material. Cracks during casting are formed by the passage of a peritectic reaction. The high cooling rate does not allow contact melting products to fill the pores that coalesce into cracks. With SPS, the main driving force for the formation of cracks is the effect of the thermal expansion coefficient. The analysis of XRD and results of mechanical testing revealed the maximum tensile micro stresses (425–430 MPa) in samples obtained at a high cooling rate. A decrease in cooling rate promotes the formation of high-density polycrystalline Al13Fe4. It is noted that the material prepared by SPS has a fine-grained structure by using Al13Fe4 powder as the initial material. The highest indicators of flexural strength are 60 ± 10 MPa, Vickers hardness HV = 8.2 ± 0.8 GPa, fracture toughness K1c = 1.5 ± 0.1MPa × m−0.5, modulus of elasticity 180 ± 10 GPa. The fractography of the surfaces after the flexural test has common features of a quasi-brittle trans crystalline fracture with a “river” structure.

Exploring the effect of raw material properties on continuous twin-screw wet granulation manufacturability

Twin-screw wet granulation (TSWG) stands out as a promising continuous alternative to conventional batch fluid bed- and high shear wet granulation techniques. Despite its potential, the impact of raw material properties on TSWG processability remains inadequately explored. Furthermore, the absence of supportive models for TSWG process development with new active pharmaceutical ingredients (APIs) adds to the challenge. This study tackles these gaps by introducing four partial least squares (PLS) models that approximate both the applicable liquid-to-solid (L/S) ratio range and resulting granule attributes (i.e., granule size and friability) based on initial material properties. The first two PLS models link the lowest and highest applicable L/S ratio for TSWG, respectively, with the formulation blend properties. The third and fourth PLS models predict the granule size and friability, respectively, from the starting API properties and applied L/S ratio for twin-screw wet granulation. By analysing the developed PLS models, water-related material properties (e.g., solubility, wettability, dissolution rate), as well as density and flow-related properties (e.g., flow function coefficient), were found to be impacting the TSWG processability. In addition, the applicability of the developed PLS models was evaluated by using them to propose suitable L/S ratio ranges (i.e., resulting in granules with the desired properties) for three new APIs and related formulations followed by an experimental validation thereof. Overall, this study helped to better understand the effect of raw material properties upon TSWG processability. Moreover, the developed PLS models can be used to propose suitable TSWG process settings for new APIs and hence reduce the experimental effort during process development.

Design principles for 3D-printed thermally activated shape-morphing structures

Morphing structures can change their shape in response to thermal excitation and are commonly used to enhance the performance of actuators, soft robotics, and biomedical devices. One of the main challenges is the inverse design problem, in which a deformed target shape is prescribed and the initial material properties, distribution, and geometry are to be determined. To tackle this challenge, a model for the thermo-mechanical response of free standing multi-layered struts that experience moderate to large deflections is developed. The model is validated through thermally activated 3D-printed bi-layer beams. Next, the model is exploited to develop an efficient inverse design algorithm that accepts a target function as an input and computes the referential configuration that can achieve the required thermally-activated deformations. It is shown that the solution to the inverse problem is not unique, thus providing flexibility in design. The merit of the algorithm is illustrated through the inverse design of three thermally-activated strut-based target shapes. The simplicity and robustness of the algorithm reveals fundamental principle guidelines for inverse design of thermally activated shape morphing structures and enables its extension to other stimuli.

Fabrication and hardness of in-situ Al3Ti–Al2O3 composite

In this work, an in-situ Al3Ti–Al2O3 composite was optimally synthesized from raw powders via mechanical milling and conventional sintering processes. The strong influence of milling time on the promotion of the phase reaction between the initial TiO2 and Al materials was proven by using X-ray diffraction and surface morphology analysis. The obtained results showed that the milling process did not initiate any reaction between the raw TiO2 and Al materials. However, the milling process was important for creating a homogeneous powder mixture and refining the particle size of the powders. The Al3Ti–Al2O3 composites were completely formed after conventional sintering at 750°C for 30 min for a milling time of over 4 h. The highest obtained microhardness of the composite was approximately 130 HV, which was suggested to be related to the microstructure of the bulk composite specimen consisting of two main phases, the Al3Ti matrix and the Al2O3 particles dispersed in the matrix. A small portion of an unidentified phase, a Ti-rich compound, was found in the matrix together with a tiny fraction of AlTi3. We suggest that the optimal sintering process and mechanical milling are important key factors in fabricating bulk hardness Al3Ti–Al2O3 composite materials.

Comparison of costs associated with transcatheter mitral valve repair: PASCAL vs MitraClip in a real-world setting

AimsWe aimed to conduct a clinical process cost analysis to evaluate all upcoming costs of mitral valve transcatheter edge-to-edge repair (M-TEER) treatment using the MitraClip and the PASCAL repair system.MethodsFirst, we prospectively enrolled 107 M-TEER patients treated with either the PASCAL or MitraClip system and compared all upcoming costs during the M-TEER procedure and the associated in-hospital stay. Second, we retrospectively analysed 716 M-TEER procedures with regard to the occurrence of complications and their associated costs. All materials used in the catheterization laboratory for the procedures were evaluated. The cost analysis considered various expenses, such as general in-hospital costs, device costs, catheter laboratory and material costs.ResultsIn the prospective study, 51 patients were treated using the PASCAL system, and 56 were treated using the MitraClip system. The two groups had comparable baseline characteristics and comorbidities. The total in-hospital costs were 25 414 (Interquartile range (IQR) 24 631, 27 697) € in the PASCAL group and 25 633 (IQR 24 752, 28 256) € in the MitraClip group (p = 0.515). The major cost driver was initial material expenditure, mostly triggered by device costs, which were similar to the PASCAL and MitraClip systems. Overall intensive care unit and general ward costs did not differ between the PASCAL and MitraClip groups. In the retrospective analysis, M-TEER-related complications were rare but were associated with higher costs, mainly due to prolonged hospitalisation.ConclusionThe major cost driver of M-TEER was the material expenditure, which was mostly triggered by high device costs. The costs of treating patients were similar for the PASCAL and MitraClip systems. M-TEER-related complications are associated with higher costs, mainly due to prolonged hospitalisation. This analysis provides valuable insights into reducing expenses by modifying the process of M-TEER.

Overview of the process technology for the preparation of ultrahigh purity indium required for the fabrication of indium phosphide related epitaxial structures based devices needed for advanced electronic applications

Indium, a rare metal, is created incidentally during the zinc refining process. When a zinc metal is produced, valuable elements, such as indium, are recovered and reused. The sulfide minerals, sphalerite, galena, and chalcopyrite, are all common hosts for indium metals. Indium metals of varying purities (from 99% to 99.9%) are used in many different commercial, other exclusive, specialty, dentistry, and research and development settings. In the production of indium phosphide and related select bulk single crystals, such as InP, InAs, InSb, etc., and select multilayered epitaxial material-systems based device structures, such as InGaAs/InP, InGaAsP/InP, etc., an ultrahigh purity (99.99999%) indium metal is used as one of the initial and primary input materials. light-emitting diodes, infrared detectors, lasers, and other components cannot be made without these device topologies. Triple junction solar cells made of GaInP, GaAs, and Ge with 40% conversion efficiency are being developed for use in space. Metal-organic and molecular beam epitaxial methods utilize trimethyl/triethyl-indium-epi-precursors, the high purity indium derivatives, as starting materials to develop and manufacture multilayered structures of InGaAs/InP, InGaAsP/InP, InGaN/InP AlInN, etc. The purpose of this review is to quickly touch on indium mineral sources, important uses for different indium metal grades, and the processes needed to refine, purify, and ultrahigh purify indium to higher purity levels using a zone refining–melting–leveling process, as well as impurity segregation considerations. The use of vacuum, inert gas environments, and an external electromagnetic field to efficiently segregate, levitate, stir, homogenize, and mix the molten zone/melt interface area (region) as well as purity analyses at ppb levels, class clean room, and packaging concepts were also discussed. This review also touched briefly on the use of ultrahigh purity indium in the preparation of TMIn, TEIn, and InCl precursors necessary for the growth of device structures by molecular beam, metal-organic vapor phase, atomic layer epitaxial, and chemical vapor deposition processes. Purifying and preparing polycrystalline indium to a type 7 N purity level as well as standardization and criticality testing for fine-tuning system parameters are essential parts of developing the purification process technology. It also highlights various compound semiconductors and epitaxial systems, such as high purity indium compounds, such as indium phosphide, for cutting-edge electronic applications. Material yield enhancement, impurity management (including C, O, N, and others), consistent results, impurity reduction (down to the ppb level), and class clean packaging are all active topics of research and development. There has been a rise in demand for ultrapure metals (7–10 N) with stringent purity criteria in the aerospace and defense sectors, where they are used in cutting-edge nanoelectronic applications. This literature review delves into these and related topics regarding the production of ultrahigh purity indium. The major objective of this review is to provide a concise summary of the research and development progress made toward the ultrahigh purity (7N-99.99999%) indium preparation and its epitaxial electronics application considerations as of the time of this writing.

TSUNAMI RUN-UP CONSIDERING TIME VARIATION OF DENSITY OF INUNDATION WATER

Aiming for the advancement of tsunami load, historical and/or prospective tsunami scale evaluations, practical empirical formulas for evaluating friction factor K of inundation flow and density ρ of inundation water over a movable bed, which can be applied to a tsunami run-up theory, are proposed using experimental data whose amount (range) is increased (expanded) by carrying out additional experiments on ρ and run-up of inundation flow with sediment, and verification data of the above theory under a uniformly sloping movable bed condition are provided. Series solutions with a higher universality to the run-up of tsunami inundation flow with sediment over a uniformly sloping movable bed, in which both K and ρ depend on time, are derived under the conditions depending on an incident bore height h1 at shoreline (or an initial stored water depth), bed slope i, median particle diameter d50 of initial bed material, and examples of the solutions are shown. The solutions are applicable to the case that ρ is independent on time, i.e., the case of inundation flow without sediment over a movable bed or fixed bed. Including the case of inundation flow without sediment, validity of one of the solutions is also verified through a comparison with the verification data on run-up distance.

Features of the expression of breeding traits in Linum usitatissimum L. somaclones

Aim. Determining the level of expression, variability and features of inheritance of the main breeding traits of flax somaclones (Linum usitatissimum L.) in connection with the possibility of their use as initial selection material was the aim of our research. Methods. Hypocotyl and epicotyl segments for the induction of callusogenesis and somatic embryogenesis were cultured in vitro on the nutrient medium of Murashige and Skoog with the addition of 1.00 mg/l 6-benzylaminopurine and 0.05 mg/l 1-naphthylacetic acid, 30 g/l sucrose, a photoperiod of 16 h, illumination 2500 lux, relative air humidity 60–80 %, air temperature 22–24°C. Somaclones were adapted in vivo, and their generations were studied in the field. Results. Somaclones of the Hlinum variety were tested in the field according to the main selection traits and were not significantly inferior to the control variant; however, among them it is possible to single out some valuable individual plants for further breeding. Conclusions. Peculiarities of correlations between traits indicate the possibility of creating breeding material with a high level of fibrousness and seed productivity at the same time, high fiber mass and its content, allow selection for fibrousness by indirect traits – total and/or technical stem length, stem mass. A promising direction is the use of somaclones as sources of a high level of manifestation of the trait of the number of capsules on a plant (up to 17 pcs.).

РЕНТГЕНОФЛЮОРЕСЦЕНТНЫЙ АНАЛИЗ ИЗДЕЛИЙ ИЗ ЦВЕТНОГО МЕТАЛЛА ПРЕДТЮРКСКОГО ВРЕМЕНИ, ОБНАРУЖЕННЫХ НА НЕКРОПОЛЕ ЧОБУРАК-I (СЕВЕРНЫЙ АЛТАЙ)

During excavations of burial complexes in Altai, which belong to the Bulan-Koby archaeological culture, items made of non-ferrous metal were found. However, their purposeful study has not yet been undertaken, which limits the possibilities for making the necessary scientific interpretations. This article presents the results of X-ray fluorescence analysis of a small series of finds from the Choburak-I necropolis. This site is located in the Northern Altai and dates back to the preTurkic period. The obtained determinations of the chemical composition of simple decorations demonstrate the variety of recipes used in casting the initial materials. Of particular importance are the items made of brass. The presented variety of metal alloys can testify to wide contacts of the Altai population in the pre-Turkic period, as well as to the existence of local traditions of decoratiions making. It is important to continue the systematic study of similar and other finds from non-ferrous metal, which are in museum collections in Russia and abroad.

Analisis Kesulitan Membaca Permulaan Pada Siswa Dasar Kota Bekasi

This research was motivated by the learning difficulties experienced by class IA students at SDN Teluk Pucung VI Kota Bekasi in the initial reading material. This study is aimed to determine the ability of students for beginning reading and the types of difficulties faced by students in beginning reading. The method used in this research is a qualitative research with a case study approach. The data collection techniques used are field observation, indept interviews, and documentation. The model analysis and interpretation of data using interactive model proposed by Miles and Hubermen, namely: data collection, data reduction, data presentation, and drawing conclusions. The results showed that 6 students were able to read the beginning but still had difficulty, and 1 student could not read the beginning. The types of difficulties experienced by students include (1) difficulty distinguishing similar letters, (3) not being able to understand sound symbols, (3) having a deficiency in visual memory, (4) having a lot of reading errors, and (5) not being able to read fluent reading. Based on these results, it can be concluded that the students of class SDN Teluk Pucung VI Kota Bekasi still have difficulty reading the beginning. Collaboration between teacher and parents are needed for the sake of the students in the future time

Influence of the Structural-Phase Composition of the Initial Charge Material on the Qualitative Characteristics of Castings from Al-Si-Mg System Alloy

Introduction. The work focuses on solving quality problems of castings made of Al-Si-Mg alloy (AK9). The paper draws attention to the absence of a unified theory of alloy modification and the need to find solutions that ensure good product quality. The reasons for bad quality due to the weak justification of the choice of the manufacturer of the initial charge material — ingots are considered. Ingots from two suppliers are compared in terms of the structural-phase state. The paper shows how it causes defects in castings. The inefficiency of traditional methods of suppressing the formation of brittle plates of the iron-containing phase in the alloy of the Al-Si-Mg system due to the presence of Mn in the chemical composition of the alloy is noted. If the specified flaw is inherited from the source material, the generally accepted approach does not work. The article formulates the recommendations for solving this problem. The introduction of the proposed approach into production practice can open the way to solving an important applied task — to improve the wording of tasks for tenders. The relevance of the study is due to the widespread use of alloys of the Al-Si-Mg (AK9) system in modern mechanical engineering, including in aerospace structures. The work objective is to study the influence of the structural-phase state of the source material on the qualitative characteristics of finished castings from the Al-Si-Mg alloy system.Materials and Methods. Eight casts were analyzed, in which ingots from two manufacturers were used. Radiography revealed a correlation between the fracture structure of castings, structure and quality indicators. Scanning electron microscopy was used to analyze the microstructure and chemical composition of the phases. When setting quality requirements, the authors proceeded from the existing industry and state standards. The conditions of heat treatment of samples were taken from the same documents. The spectrograms were visualized as graphs showing the intensity of the element peak in the Auger spectrum and the energy of the electrons resulting from the Auger effect.Results. The results of radiography gave grounds to assert that the products provided by supplier No. 1 had significant advantages in terms of quality. If we focused on the industry standard, the exclusion of the 2nd supplier's ingots from the process ensured the production of products without casting defects at the level of 73 %. Otherwise, this figure did not exceed 57 %. The rejection indicators were discontinuities, clusters of flaws, high porosity. After melting 5-8, which involved the materials of the 2nd manufacturer, the fractures of the samples after rupture were investigated. Locations with smooth, viscous and mixed relief are highlighted. An increase of up to ×500 made it possible to establish insignificant areas with a viscous relief, which was characteristic of brittle fracture by the cleavage mechanism. The absence of inclusions and liquations was established. The microstructure of the sections from discontinuous samples was considered. It turned out that it corresponded to the modified and heat-treated state of the AK9ch alloy without signs of burnout. Individual dark needle-like phases and single pores were noted. The conditions of dispersed Si precipitations, Al32Si10Fe5Mn and Al37Si5Fe5Mn chipping, as well as the separation of the Al36Si3Fe6Mn3 phase in skeletal form were described. The advantages of the microstructure of ingots samples from manufacturer No. 1 were listed. It corresponded to the modified state of the AK9ch alloy. The branches of dendrites and the sizes of silicon inclusions were smaller. Needle-like phases of AlxSiyFezMnq were not detected.Discussion and Conclusion. Light areas in the castings fractures were formed by a brittle fracture mechanism, which is due to the presence of AlxSiyFezMnq phase plates in the alloy structure. If iron-containing phases are inherited from the source material, then traditional methods of suppressing formation do not lead to the creation of compact equiaxed polyhedra. To improve the quality of castings, it is recommended to use ingots with a pre-modified structure, without including phase plates of variable composition AlxSiyFezMnq. The results obtained can be used, among other things, to justify the requirements for the material during tenders, which will enable the enterprises of the machine-building industry to improve the quality of products and reduce the cost of marriage. As a result, this will increase their competitiveness in the Russian and world markets.

YÜKSEK ENERJİLİ ÖĞÜTME İLE ÜRETİLEN Al2O3 TAKVİYELİ CU KOMPOZİTLERDE PARÇACIK BOYUTUNUN ETKİSİ

Production of copper (Cu) composites with a reinforced Cu matrix using mechanical alloying with Aluminum oxide (Al2O3) particles of different sizes was achieved using high-energy ball milling procedure. The initial materials consisted of inert gas-atomized spherical electrolytic Cu powders containing 0.5 wt. % commercial Al2O3 powders, with particle sizes ranging from 10 µm to 1 µm. Cu powders with different particle sizes of Al2O3 were high-energy ball milled at 500 rpm for 3 hours to attain a consistent distribution of Al2O3 throughout in the Cu matrix. The powders that were high-energy ball milled were then subjected to cold-pressing at 500 MPa and isothermally sintered for 1.5 hours at 880°C in an Ar atmosphere. The fabricated copper composite materials were characterized using X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDXS), density and macrohardness tests. The wear properties and mechanism were investigated through tribological pin-on-disc experiments, which revealed that the reinforcing effect was more significant when finely dispersed Al2O3 particles were combined into the Cu matrix compared to coarse Al2O3 particles.

A time-space window between Eocene karst bauxite genesis and the first molasse deposition in the Dinaric Foreland Basin in the North Dalmatia, Croatia

Karst bauxite deposits in the North Dalmatian piggyback basin (NDPGB) are a part of the Mediterranean bauxite belt, which is the largest European bauxite deposit zone; however, there is a general lack of information regarding the genesis, age, and precursor of the bauxite deposits in this region. In this study, we combined detrital zircon U–Pb geochronology with compositional, mineralogical, and morphological data from four bauxite locations in the NDPGB to provide a new palaeogeographical and palaeoenvironmental evolution model for the Lutetian–Rupelian timeframe of the NDPGB. The Eocene climatic conditions began with the Palaeocene–Eocene Thermal Maximum event (∼56 Ma), followed by the Early Eocene Climatic Optimum (∼49 Ma) and Middle Eocene Climatic Optimum (∼40 Ma), and were completed as a cooling trend culminating around the Eocene/Oligocene boundary (∼34 Ma), with a shift towards an icehouse climate. These events were coeval with the continuous drift of the African continent towards Eurasia and the subsequent closure of the western part of the former Neo-Tethys Ocean associated with massive volcanic activity. Based on the bauxite deposits of the NDPGB, Early Eocene limestones formed in the last phase of the long-lasting Adriatic Carbonate Platform. The Middle Eocene orogenic activity resulted in an elevation in this area. High average temperatures, accelerated hydrological cycles and precipitation, and intensive continental weathering with increased volcanic carbon input resulted in favourable conditions for the development of karst bauxites at this time. Further Upper Eocene tectonic deformation of the NDPGB area resulted in the development of bauxite traps and enabled redeposition of the initial bauxite material. Subsequently, the bauxite deposits were covered with clastic carbonate molasse derived from the intensive erosion of the young Dinaric orogeny. The implications of this study are as follows. First, it provides new information on the timing of bauxitisation in the area by providing the first radiometric zircon geochronology, which refined and restricted the time window for bauxite formation in this region. Additionally, our results provide a new perspective on the possibility of aeolian precursors in karst bauxite formation and provide new constraints on the first tectonic marks of the initial Dinaric orogeny.

Creation of doubled haploid lines of maize <i>Zea mays</i> L. by resynthesis from a tetraploid population

The search for new, effective methods for broadening the genetic polymorphism of the original breeding material remains one of important problems of hybrid maize breeding. Globally, breeding of commercial maize varieties and hybrids is carried out using diploid genotypes, whereas tetraploid sources of initial material and wild relatives of maize are poorly involved in the breeding process. The direct heteroploid crosses between diploid and tetraploid genotypes lead to the formation of weakly fertile or completely sterile triploid hybrids, which are cytologically unstable in subsequent generations. Tetraploid maize (2n=40), as well as some wild relatives with tetraploid genome, such as Zea perennis Hitchk. (2n=40) and Tripsacum dactiloides (L.) L. (2n=72), are attractive to breeders as sources for improving economically valuable traits. The attractiveness of resynthesized diploid lines is explained by the fact that unequal crossing over between homologous chromosomes forming polyvalent associations of chromosomes, more chromosomal rearrangements occur in tetraploids than in diploid genotypes, the chromosomes of which form bivalents. Synthetic tetraploid populations of maize and its tetraploid wild relatives have great potential of variability for improving diploid maize. The authors proposed a direct method for the resynthesis of doubled haploid lines using haploid induction and an indirect method for obtaining diploid lines by heteroploid crossing and subsequent segregation of a triploid hybrid in the progeny. The method of resynthesizing the tetraploid maize genome to diploid serves as an ideal model for studying the processes of crossing over in meiosis between multivalent associations of homologous chromosomes; it is promising for obtaining diploid lines with an increased frequency of recombination between the homologous chromosomes of different genomes, combined into a common one, and can serve as a source for obtaining aneuploid series.

Niobium monoxide NbO single crystal growing by floating zone method

In this work, a single crystal of niobium monoxide NbO was grown by crucible-free zone melting method. Polycrystalline NbO with ordered cubic structure (sp.gr. Pm-3m) with vacancies in both metal and nonmetal sublattices served as an initial material. According to XRD data, the grown niobium monoxide NbO single crystal has predominant growth in the [111]B1 direction and contains only one ordered cubic phase NbO, its lattice constant is equal to a = 421.2 pm. The growing mechanism of the NbO single crystal was clarified, in accordance with the Kossel and Stransky theory, it was suggested that the single crystal grows layer by layer. Analysis of the Kikuchi lines geometry allowed the orientations and disorientations of single crystal to be determined to high precision. An analysis of the diffraction pattern and intersection of Kikuchi lines showed that the NbO single crystal has (111)B1 facet. The experimental Laue diffraction patterns confirmed this direction of niobium monoxide NbO single crystal growth.

Composite Membrane Based on Graphene Oxide and Carboxymethylcellulose from Local Kazakh Raw Materials for Possible Applications in Electronic Devices

The synthesis of new composite nanomaterials based on graphene oxide (GO)modified with cellulose and its derivatives, as well as nanocellulose, is currently an important direction and contributes toward solving many problems in various fields such as nanotechnology, information technology, medicine, high-dielectric materials, and nanoelectronics. In this work, for the first time, for the production of GO and its membrane with carboxymethylcellulose (CMC), local Kazakhstan “Ognevsky” graphite was used as the initial raw material. In this regard, the preparation of nanocomposites of GO modified with cellulose derivatives, including CMC, attracts great interest from scientists and expands its field of practical application due to the significant changes in its physicochemical properties. In this work, the GO obtained using the Hummers method was modified by CMC, and its physicochemical, structural, and electrical characteristics were studied. The GO/CMC membrane was synthesized by mixing 1% GO with crushed solid mass of CMC (0.03 g; 0.06 g; 0.15 g) and then processing using ultrasound. The surface morphology of the GO/CMC membrane was studied using scanning electron microscopy (SEM). It has been established that by increasing the mass of CMC (0.03 g; 0.06 g; 0.15 g), the polymerization of CMC occurs on the surface of GO nanosheets. Cross-sectional micrographs of GO/CMC show the formation of sandwich-like layered structures. The synthesis efficiency (yield) of GO from synthetic graphite is 10.8%, and GO from Ognevsky graphite is 11.9%, almost 1.1% more than GO from synthetic graphite. The mechanical tensile strength increases from 2.3 MPa to 14.3 MPa and the Young’s modulus from 2.3 MPa to 143 MPa. The electrical parameters of the humidity sensor based on GO and GO/CMC membranes (0.03 g; 0.06 g; 0.15 g) were studied as a function of humidity to determine the performance of the device.

Three-Dimensional Printing of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] Biodegradable Scaffolds: Properties, In Vitro and In Vivo Evaluation.

The results of constructing 3D scaffolds from degradable poly(3-hydrosbutyrpate-co-3-hydroxyvalerate) using FDM technology and studying the structure, mechanical properties, biocompatibility in vitro, and osteoplastic properties in vivo are presented. In the process of obtaining granules, filaments, and scaffolds from the initial polymer material, a slight change in the crystallization and glass transition temperature and a noticeable decrease in molecular weight (by 40%) were registered. During the compression test, depending on the direction of load application (parallel or perpendicular to the layers of the scaffold), the 3D scaffolds had a Young's modulus of 207.52 ± 19.12 and 241.34 ± 7.62 MPa and compressive stress tensile strength of 19.45 ± 2.10 and 22.43 ± 1.89 MPa, respectively. SEM, fluorescent staining with DAPI, and calorimetric MTT tests showed the high biological compatibility of scaffolds and active colonization by NIH 3T3 fibroblasts, which retained their metabolic activity for a long time (up to 10 days). The osteoplastic properties of the 3D scaffolds were studied in the segmental osteotomy test on a model defect in the diaphyseal zone of the femur in domestic Landrace pigs. X-ray and histological analysis confirmed the formation of fully mature bone tissue and complete restoration of the defect in 150 days of observation. The results allow us to conclude that the constructed resorbable 3D scaffolds are promising for bone grafting.