Measurement of young's modulus and hardness of Al-50 wt % Sn alloy phases using nanoindentation

The nanoindentation method was used to measure the Young's modulus and hardness of the phases of the alloy Al-50 wt % Sn: α-aluminum and eutectic. Samples are obtained in different ways, i.e., traditionally via the transition of the melt into a homogeneous structural state by heating to a certain temperature, followed by cooling using the cooling rate greater by the order than that of the traditional method and via the addition of 0.06 wt % Ti and 1 wt % Zr to the binary alloy. It has been found that the most significant effect of the Al-50 wt % Sn phases on the Young's modulus is the transition of the melt into a homogeneous structural state and the introduction of Zr into the melt. As part of the mathematical theory of elasticity, a numerical evaluation of the interfacial pressure that arises due to the difference between Young's modulus of α aluminum and eutectic has been performed. The calculation has showed that the extra pressure is nine times less for the alloy formed through the transition of the melt into a homogeneous structural state than for the alloy produced via a traditional way. © 2013 Pleiades Publishing, Ltd

Research on the possibility of extending the shelf life of cheese raw material and heat-treated cheese by their freezing for further use in HoReCa

The article presents the results of a study of the regularities of changes in the functional properties and quality indicators of heat-treated cheeses made from frozen cheese raw material or frozen after thermomechanical processing for further use in HoReCa. The objects of the study were: Caliatta cheese — a semi-hard ripening cheese intended as the main raw material in the production of heat-treated cheese, as well as heat-treated «pizzacheese», subjected to freezing at temperatures of minus 14 ±2 °Cand minus 55 ±2 °Cand low-temperature storage at a temperature of minus 14 ±2 °Cfor 270 days, followed by defrosting at a temperature of 20 ±2 °C. To confirm the possibility of using the freezing technique in order to increase the shelf life of both the original cheese raw material and heat-treated cheese, their microbiological and physicochemical indicators were determined by standardized methods. Studies of structural and mechanical (rheological) properties were carried out on a Weissenberg rheogoniometer, recording changes in the elastic modulus (G’) and dynamic viscosity (h’). The length of the cheese thread, as one of the main functional properties of the «pizza-cheese», was assessed with a fork test after baking. Organoleptic characteristics were assessed by flavor, texture and appearance. Research results have shown that low-temperature storage of frozen cheese can be considered as a way to retard biological and physicochemical changes, which is a safe way to increase shelf life. Freezing cheese raw material increases the length of the cheese thread in proportion to the temperature and duration of the low-temperature storage. When obtaining heat-treated cheese from both unfrozen and frozen cheese raw material, a significant deterioration in the desired functional properties is observed. Thus, the receipt of heat-treated cheese from the original cheese raw material for further use in the production of pizza is justified only by economic feasibility. Freezing «pizza-cheese» at a temperature of minus 55 ±2 °C, made from unfrozen cheese raw material, ensures the preservation of functional properties and increases the shelf life up to 150 days

QED radiative corrections to impact factors

We consider the radiative corrections to the impact factors of electron and photon. According to a generalized eikonal representation the e\bar e scattering amplitude at high energies and fixed momentum transfers is proportional to the electron form factor. But we show that this representation is violated due to the presence of non-planar diagrams. One loop correction to the photon impact factor for small virtualities of the exchanged photon is obtained using the known results for the cross section of the e\bar e production at photon-nuclei interactions.Comment: 8 pp, plain LaTe

ИССЛЕДОВАНИЕ ВЛИЯНИЯ СТРУКТУРНОГО СОСТОЯНИЯ РАСПЛАВА НА КРИСТАЛЛИЧЕСКОЕ СТРОЕНИЕ И МЕХАНИЧЕСКИЕ СВОЙСТВА ФАЗ СПЛАВА AL-50 МАС.%SN МЕТОДОМ НАНОИНДЕНТИРОВАНИЯ

Nanoindentation is used to measure Young's modulus, the hardness, the plasticity, and the yield strength of the phases in Al-50 wt % Sn alloy samples prepared by a traditional method and using liquid-state homogenization. The effect of an increase in the cooling rate by an order of magnitude and alloying with 0.06 wt % Ti or 1 wt % Zr on the mechanical properties of the phases in the Al-50 wt % Sn alloy is studied. The most substantial effect on Young's modulus of the phases in the Al-50 wt % Sn alloy is found to be exerted by the homogenization of the metallic liquid and the introduction of zirconium in the alloy melt: the metal forming of an ingot is improved substantially. © 2013 Pleiades Publishing, Ltd

Maintenance of potato varieties in <i>in vitro</i> and field collections of the Russian Potato Research Centre

The main biological feature of potato varieties is vegetative reproduction. This mode of reproduction can be associated with problems due to the physiological ageing of the crop and the accumulation of specific pathogens causing reduced tuber yields. In order to avoid these problems, potato seed production widely uses modern biotechnological methods. The use of meristemic technologies allows preserving the identity of the biomaterial in the process of maintaining the potato collection in vitro, but even under these conditions there is a threat that modifications of individual economically valuable traits may get fixed. In potato varieties, such non-heritable deviations manifest themselves in the form of a shift in phenophases and the period of tubers ripening. The use of modern high-tech methods of varietal resources storage implemented on the basis of biotechnological approaches, makes it possible to maintain high quality of biomaterial. At the same time, mobility and practicality remain the main criteria for the effectiveness of different storage methods, depending on the extent to which they can be used in practice. In this review, the collection of varieties at Russian Potato Research Center is used as an example for considering the main stages of the formation and functioning of a modern Bank of Healthy Potato Varieties (BHPV), which supplies various regions of the Russian Federation with high-quality phytopathogen-free potato varieties

The transcription factor dFOXO controls the expression of insulin pathway genes and lipids content under heat stress in <i>Drosophila melanogaster</i>

The insulin/insulin-like growth factor signaling (IIS) pathway is one of the key elements in an organism’s response to unfavourable conditions. The deep homology of this pathway and its evolutionary conservative role in controlling the carbohydrate and lipid metabolism make it possible to use Drosophila melanogaster for studying its functioning. To identify the properties of interaction of two key IIS pathway components under heat stress in D. melanogaster (the forkhead box O transcription factor (dFOXO) and insulin-like peptide 6 (DILP6), which intermediates the dFOXO signal sent from the fat body to the insulin-producing cells of the brain where DILPs1–5 are synthesized), we analysed the expression of the genes dilp6, dfoxo and insulin-like receptor gene (dInR) in females of strains carrying the hypomorphic mutation dilp641 and hypofunctional mutation foxoBG01018. We found that neither mutation influenced dfoxo expression and its uprise under short-term heat stress, but both of them disrupted the stress response of the dilp6 and dInR genes. To reveal the role of identified disruptions in metabolism control and feeding behaviour, we analysed the effect of the dilp641 and foxoBG01018 mutations on total lipids content and capillary feeding intensity in imago under normal conditions and under short-term heat stress. Both mutations caused an increase in these parameters under normal conditions and prevented decrease in total lipids content following heat stress observed in the control strain. In mutants, feeding intensity was increased under normal conditions; and decreased following short-term heat stress in all studied strains for the first 24 h of observation, and in dilp641 strain, for 48 h. Thus, we may conclude that dFOXO takes part in regulating the IIS pathway response to heat stress as well as the changes in lipids content caused by heat stress, and this regulation is mediated by DILP6. At the same time, the feeding behaviour of imago might be controlled by dFOXO and DILP6 under normal conditions, but not under heat stress

El moderno sistema de tributación de los bienes inmuebles

Taxation has long been an integral part of the functioning of the state, and if earlier the so-called “taxes” were used exclusively for the ruling elite and the bureaucratic apparatus, today taxes, forming the state budget revenue item, are subsequently redistributed to support programs various spheres of society, be it medicine, education, science, etc. The article is devoted to the study of the modern system of taxation of real estate, in particular, the specific features of real estate as objects of taxation, the main types of property taxes, regulatory legal acts in the field of taxation, as well as the advantages and disadvantages of the tax structure of the Russian Federation.Los impuestos han sido durante mucho tiempo una parte integral del funcionamiento del estado, y si antes los llamados «impuestos» se usaban exclusivamente para la élite gobernante y el aparato burocrático, hoy los impuestos, que forman la partida de ingresos del presupuesto estatal, se redistribuyen posteriormente a programas de apoyo en diversas esferas de la sociedad, ya sea medicina, educación, ciencia, etc. El artículo está dedicado al estudio del sistema moderno de tributación de bienes inmuebles, en particular, las características específicas de los bienes inmuebles como objetos impositivos, los principales tipos de impuestos a la propiedad, actos legales regulatorios en el campo de los impuestos, así como las ventajas y desventajas de la estructura tributaria de la Federación de Rusia

Physiological and biochemical features of fig cultivars (<I>Ficus carica</I> L.) from the collection of the Nikita Botanical Gardens

Background. Identification of promising fig cultivars (Ficus carica L.) with high content of bioactive compounds in fruits and increased adaptability to moisture deficiency is important for breeding and fruit growing in arid regions.Methods. The chemical analysis of fruits was performed using conventional methods. The content of essential elements was measured on a Kvant 2MT atomic absorption spectrophotometer. Drought resistance was assessed using the method of determining the water-holding capacity and resistance to dehydration in the leaves of fruit crops.Results. Fruits of cv. ‘Muason’ demonstrated the highest dry matter content (26.60 ± 1.30%), total phenolic compounds (169.0±26.0 mg%), sugars (mono: 15.03 ± 1.25%, and total: 17.46 ± 0.56%), water-soluble pectin (1.17%), total pectin substances (1.99%), and K (13565 ± 805 mg/kg); fruits of cv. ‘Pomoriysky’ had the maximum content of Ca (532 ± 65 mg/kg), Mg (982 ± 121 mg/kg), and Mn (1.98 ± 0.182 mg/kg); ‘Sabrutsiya Rozovaya’ excelled in the content of ascorbic acid (17.32 ± 0.78 mg%), Fe (15.413 ± 1.989 mg/kg), Zn (10.688 ± 1.338 mg/kg), and Cu (1.435 ± 0.132 mg/kg). ‘Sabrutsiya Rozovaya’ showed high drought resistance, ‘Pomoriysky’ had a medium degree of resistance, while ‘Muason’ demonstrated low water regime values. The loss of 15–20% of moisture by the leaves is critical: dehydration exceeding this limit leads to the impossibility of restoring satisfactory turgor. Conclusion. Fruits of the studied fig cultivars belong to the group of products with high K and Mg content, and satisfactory content of Fe, Zn and Mn. ‘Sabrutsiya Rozovaya’, a potentially adaptable cultivar with resistance to hydrothermal stress, was identified for its increased water-retaining capacities and high reparative ability of leaf tissues. It is recommended for use in the breeding for drought resistance and for establishment of large-scale plantations in arid regions