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

Role of doped layers in dephasing of 2D electrons in quantum well structures

The temperature and gate voltage dependences of the phase breaking time are studied experimentally in GaAs/InGaAs heterostructures with single quantum well. It is shown that appearance of states at the Fermi energy in the doped layers leads to a significant decrease of the phase breaking time of the carriers in quantum well and to saturation of the phase breaking time at low temperature.Comment: 4 pages, 6 figure

Terahertz gain on intersubband transitions in multilayer delta-doped p-Ge structures

A far-infrared laser concept based on intersubband transitions of holes in p-type periodically delta-doped semiconductor films is studied using numerical Monte Carlo simulation of hot-hole dynamics. The considered device consists of monocrystalline pure Ge layers periodically interleaved with delta-doped layers and operates with vertical hole transport in the presence of an in-plane magnetic field. Population inversion on intersubband transitions arises due to light-hole accumulation in E perpendicular to B fields, as in the bulk p-Ge laser. However, the considered structure achieves spatial separation of hole accumulation regions from the doped layers, which reduces ionized-impurity and carrier-carrier scattering for the majority of light holes. This allows a remarkable increase of the gain in comparison with bulk p-Ge lasers. Population inversion and gain sufficient for laser operation are expected up to 77 K. Test structures grown by chemical-vapor deposition demonstrate feasibility of producing the device with sufficient active thickness to allow quasioptical electrodynamic cavity solutions

A model for the education of a student of a vocational pedagogical educational institution through the gaming simulation

The relevance of the problem subject to the research is conditioned by the discrepancy between (a) the orientation of the modern vocational-pedagogical education on the result of the future teacher training that is based on the subject matter and contents, and (b) the need to develop pedagogical skills. The application of the gaming simulation within the process of pedagogical skills development takes such skills to a completely new level. A study of the process of pedagogical skills development at students of a vocational-pedagogical education by way of the gaming simulation is the purpose of the article. Experiment and research activities were carried out during four years. A pedagogical experiment using the specially developed programme allowing discovering the level of pedagogical skills development at the trainees is the leading method for the research of this problem. Research results: The article provides for a model for the education of a student of a vocational-pedagogical educational institution through the gaming simulation; a scheme for this model implementation has been developed. Article contents may be useful for lecturers and students of pedagogical higher education institutions at the monitoring of the education quality. © 2016 Fominykh et al

Hardiness of adolescents with special educational needs: Research results

The relevance of the problem under study is due to the fact that the current worldwide trend shows high dynamics of the increase in the number of children with SEN, which requires that society in general and the education system, in particular, should develop approaches to the socialization and adaptation of people with SEN through strengthening their personal resources. The purpose of the article is to explore the peculiarities of the phenomenology and structure of hardiness of adolescents with SEN in comparison with the conventionally healthy peers. The main method applied in the research of this problem is a comparative study based on the cross-sectional method, which makes it possible to identify the specificity of hardiness of adolescents with SEN. The results of the research: the research revealed the peculiarities of expression and relationship of the components of hardiness of adolescents with SEN in comparison with the conventionally healthy peers. The materials of the article may be useful for educational and social psychologists in devising programs for psychological support and comprehensive psycho-social assistance to families with children with SEN, which will contribute to the successful integration of adolescents with SEN in society. © 2016 Shchipanova et al

Interactive Methods of Teachingforeign Language at University

В современной лингводидактике существует множество методов преподавания иностранных языков. Одной подгруппой из этих методов являются интерактивные методы обучения, использование которых позволяет пробудить мотивацию студентов к изучению иностранного языка и повысить эффективность занятий. В статье разбираются различные классификации интерактивных методов и даются рекомендации преподавателям по их применению в профессиональной деятельности.There are many methods of teaching foreign languages in modern linguodidactics. One subgroup of these methods are interactive teaching methods, the use of which allows teachers to motivate students to learn a foreign language and increase the effectiveness of classes. The article analyzes various classifications of interactive methods and gives recommendations to teachers on their application in professional activities

Quantum corrections to conductivity: from weak to strong localization

Results of detailed investigations of the conductivity and Hall effect in gated single quantum well GaAs/InGaAs/GaAs heterostructures with two-dimensional electron gas are presented. A successive analysis of the data has shown that the conductivity is diffusive for $k_F l=25-2$ and behaves like diffusive one for $k_F l=2-0.5$ down to the temperature T=0.4 K. It has been therewith found that the quantum corrections are not small at low temperature when $k_F l\simeq 1$. They are close in magnitude to the Drude conductivity so that the conductivity $\sigma$ becomes significantly less than $e^{2}/h$ (the minimal $\sigma$ value achieved in our experiment is about $3\times 10^{-8}\Omega^{-1}$ at $k_Fl\simeq 0.5$ and $T=0.46$ K). We conclude that the temperature and magnetic field dependences of conductivity in whole $k_Fl$ range are due to changes of quantum corrections.Comment: RevTex 4.0, 10 figures, 7 two-column page

Clinical and epidemiological characteristics and effectiveness of antiviral therapy for COVID-19 in children: The experience of the first year of the pandemic

Background. The use of antiviral agents can shorten the duration of the viral infection. The aim: to study the clinical and epidemiological features and the effectiveness of antiviral therapy for new coronavirus infection (COVID-19) in outpatient children.Materials and methods. From April 2020 to March 2021, 9334 outpatient children aged from 0 months to 17 years were randomly tested for new coronavirus infection. SARS-CoV-2 RNA was detected in oropharyngeal and nasal material by PCR. Patients with confirmed new coronavirus infection were prescribed interferon-alpha (IFN-α) intranasally, antiviral agents of systemic action. The control group consisted of children with COVID-19 who did not receive treatment.Results. When examining clinically healthy contact children, SARS-CoV-2 RNA was detected in 7.4 % of cases. In the structure of ARI, the specific weight of COVID-19 was 12.3 % with the peak incidence in April-May (up to 22.8 %) and NovemberDecember (up to 30.0 %). In half of the cases, children became infected in the family, and usually adults were the index patient. In 47.7 % of cases, an asymptomatic form of COVID-19 was registered without significant differences in patients of different ages. In one third of children with concomitant pathology, the disease was asymptomatic, in half it was mild, in other cases moderate severity was diagnosed. The clinical picture of COVID-19 did not differ from other ARIs. Anosmia (9.4 %) in half of the cases was combined with ageusia (4.4 %) and was significantly more common in boys. The duration of clinical manifestations in children of the control group and those who received antiviral therapy did not statistically significantly differ in mild and severity of the disease. Also, various antiviral therapy options did not significantly affect the duration of SARS-CoV-2 detection in children with various forms of COVID-19.Conclusion. In the first year of the pandemic, the novel coronavirus infection did not dominate the pattern of respiratory diseases in outpatient children. Further research is required to develop pediatric guidelines for the treatment of COVID-19 at the outpatient stage