Modern state of use of solar desalination

Water is the most necessary resource for mankind, animals and plants. Although 71% of the Earth’s surface is covered by water, 97% of it is salt water, that is, water that is not suitable for consumption. Also, continuous pollution of surface and underground water is increasing the shortage of drinking water. In solving the above problems, desalination of salt water is an important way of increasing drinking water resources. However, the high energy consumption, increased greenhouse gas emissions, large amounts of wastewater and the high cost of fresh water in desalination limit the widespread adoption of desalination technology in the industry. To solve these limitations, solar energy, which is one of the renewable energy sources, is environmentally friendly, ubiquitous, convenient to use, safe and sustainable. Currently, several constructions of SD are proposed, the main part of which is a pool construction. This research paper presents the results of comparison of the constructional structures of one- and two-basin SD, their heat-technical parameters, device productivity and economic indicators

Применение экстракорпоральных систем протезирования функций печени при острой декомпенсированной печеночной недостаточности

The aim of the study: to evaluate the efficacy of extracorporeal liver support systems in patients with acute liver failure of various etiologies.Material and methods. The study included 117 patients with acute liver failure of various etiologies. The main group consisted of 71 patients who received complex intensive therapy, including MARS-therapy and hemodiafiltration. The comparison group included 46 patients who received albumin dialysis (24 patients) and hemodiafiltration (22 patients) alone. The mean age of the patients was 34±5.6 years, the majority (56.4%) were men. Dynamic assessment of patients' severity was performed using Sequential Organ Failure Assessment (SOFA) and Model for End-Stage Liver Disease (MELD) scales.Results. A more significant reduction of SOFA and MELD scores was noted as early as by day 10 of intensive therapy in the main group with sequential use of extracorporeal liver detoxification methods — to 2.7±0.2 vs. 8.3±0.5 points (P=0.021) on SOFA and to 16.7±0.4 vs. 23.4±1.4 points (P=0.023) MELD scales. The use of a comprehensive approach to extracorporeal detoxification in acute decompensated liver failure increased the regression rate of multiple organ failure from 51.2 to 74.6% and reduced mortality from 47.8 to 25.4% (χ2=6.266; df=1; P=0.013). At the same time, the cumulative proportion of survivors depending on the type of complication within 30 days was 88.4% in the main group and 69.0% in the comparison group (χ2=4.164; df=1; P=0.042).Conclusion. A comprehensive approach to extracorporeal detoxification is highly effective, providing a more significant reduction of SOFA and MELD scores, increasing the proportion of regression of multiple organ dysfunction and reducing mortality.Цель исследования: выявить эффективность систем экстракорпоральной поддержки печени у пациентов с острой печеночной недостаточностью различного генеза.Материал и методы. В исследование включили 117 пациентов с острой печеночной недостаточностью различного генеза. Основную группу составили 71 пациент, которые получали комплексную интенсивную терапию, включая применение MARS-терапии и гемодиафильтрацию. В группу сравнения включили 46 пациентов, которым применены изолированно альбуминовый диализ — 24 пациента и гемодиафильтрация — 22 пациента. Средний возраст пациентов составил 34±5,6 лет, большинство (56,4%) были мужчины. Динамическую оценку тяжести состояния пациентов проводили по оценочным шкалам Sequential Organ Failure Assessment (SOFA) и Model for End-Stage Liver Disease (MELD).Результаты. Более существенное снижение показателей по шкалам SOFA и MELD отмечено уже к 10 суткам интенсивной терапии в основной группе при последовательном использовании методов экстракорпоральной детоксикации печени по шкале SOFA — до 2,7±0,2 против 8,3±0,5 баллов (p=0,021) и MELD — до 16,7±0,4 против 23,4±1,4 баллов (p=0,023). Применение комплексного подхода к экстракорпоральной детоксикации при острой декомпенсированной печеночной недостаточности позволило увеличить долю регресса полиорганной недостаточности с 51,2 до 74,6%, сократить летальность с 47,8 до 25,4% (χ2=6,266; df=1; p=0,013). При этом кумулятивная доля выживших в зависимости от типа осложнения в сроки до 30 суток составила при 88,4% — в основной группе и 69,0% — в группе сравнения (χ2=4,164; df=1; p=0,042).Заключение. Комплексный подход к экстракорпоральной детоксикации имеет высокую эффективность, обеспечивая более существенное снижение баллов по шкалам SOFA и MELD, позволяет увеличить долю регресса полиорганной дисфункции и сократить летальность

Perturbative Symmetry Approach

Perturbative Symmetry Approach is formulated in symbolic representation. Easily verifiable integrability conditions of a given equation are constructed in the frame of the approach. Generalisation for the case of non-local and non-evolution equations is disscused. Application of the theory to the Benjamin-Ono and Camassa-Holm type equations is considered.Comment: 16 page

CFD model of acceleration of thermal-hydrodynamic processes in solar air collectors

Recent studies on increasing the thermal-hydrodynamic efficiency of solar air collectors have been carried out on the installation of barriers of various shapes on the surface of the absorber, and this method ensures a significant increase in the energy efficiency of the collector. The transfer of the air flow washing the surface of the absorber from a laminar flow state to an accelerated lumped air flow is carried out by installing obstacles. Installation of barriers is the main factor in increasing the heat transfer in solar air collectors and prolongs the time of air flow in the collector. The barrier solar air collector has a high local heat transfer coefficient, and the Nusselt number value is up to 3.5 times higher than that of the flat plate solar air collector. Also, this article presents the results of CFD modeling of the air flow in the solar air collector, the results of which can be used in the theoretical research of the solar air collector

Ассоциация Gln27Glu полиморфизма гена β2-адренорецептора с особенностями каскада иммунорегуляторных цитокинов и продукцией IgE у больных бронхиальной астмой

The objective: to study the level of serum cytokines IL-4, IFN-γ and the activity of IgE production in patients with bronchial asthma (BA) with the consideration of the Gln27Glu-polymorphism of the β2-AR gene.Subjects and Methods. 130 people of Uzbek ethnicity were examined including 83 patients with BA. BA patients were divided into groups according to the international classification of the World Health Organization and the GINA 2006 diagnostic criteria. Genotyping was performed by polymerase chain reaction technology and restriction fragment analysis.Results. In the group with allergic BA, patients with the Gln27Gln-polymorphic variant of the β2-adrenergic receptor gene had an average IgE value (1,664.20 ± 293.29 pg/ml) higher versus patients with the Gln27Glu genotype (338.40 ± 121.33 pg/ml; p < 0.01). No significant relationship between the Gln27Glu polymorphism of the β2-adrenergic receptor gene and the activity of inductor cytokines was found. The Gln27Gln genotype of the β2-adrenergic receptor gene in patients with bronchial asthma, especially in the allergic form of the disease, is associated with hyperproduction of IgE.Цель исследования: изучить уровень сывороточных цитокинов IL-4, IFN-γ и активность продукции IgE у больных бронхиальной астмой (БА) с учетом Gln27Glu-полиморфизма гена β2-АР.Материал и методы. Обследовано 130 человек узбекской национальности, из них 83 больных БА. Больные БА распределялись по группам согласно международной классификации Всемирной организации здравоохранения и в соответствии с диагностическими критериями GINA 2006 г. Проведено генотипирование с использованием технологии полимеразной цепной реакции и анализа рестрикционных фрагментов.Результаты. В группе с аллергической БА у больных с Gln27Gln-полиморфным вариантом гена β2-адренорецептора средний показатель IgE (1 664,20 ± 293,29 пг/мл) превышал уровень такового у больных с Gln27Glu-генотипом (338,40 ± 121,33 пг/мл; p < 0,01). Достоверной взаимосвязи полиморфизма Gln27Glu гена β2-адренорецептора с активностью индукторных цитокинов не обнаружено. Генотип Gln27Gln гена β2-адренорецептора у пациентов с бронхиальной астмой, особенно при аллергической форме заболевания, ассоциирует с гиперпродукцией IgE

Equivalence classes of the second order ODEs with the constant Cartan invariant

Second order ordinary differential equations that possesses the constant invariant are investigated. Four basic types of these equations were found. For every type the complete list of nonequivalent equations is issued. As the exampes the equivalence problem for the Painleve II equation, Painleve III equation with three zero parameters, Emden equations and for some other equations is solved

Mathematical Modeling of the Combined Heat Supply System of a Solar House

Today, increasing energy efficiency in residential heating systems, saving fuel and energy resources, and improving the efficiency of using devices based on renewable energy sources is an urgent issue. The purpose of the article is to develop a mathematical model of the heat balance and conduct a theoretical study of one-story rural houses based on the use of solar energy in a non-stationary mode. To achieve this goal, an experimental one-story solar house with autonomous heat supply was built. The heat supply of the experimental solar house mainly uses solar energy, and when the heat supply load exceeds this load, the traditional boiler device is used. The power supply of the experimental solar house is provided by a solar panel (photovoltaic converter). A heat balance scheme for a solar house with autonomous heat supply and an electrothermal scheme of a physical model are proposed. Based on the proposed schemes, a mathematical model of heat balance and a calculation algorithm based on the heat balance equation of the dynamic state of the heat supply system of a one-story experimental solar house in a non-stationary mode have been developed. On the basis of mathematical modeling, the influence of the heat capacity of the wall structure on the temperature regime of the building was studied. On the basis of the MATLAB-Simulink program, the main temperature characteristics were built, on which the change in the temperature of the internal air of the building was analyzed depending on the ambient temperature. On the basis of the program, a modular scheme of the dynamic model was built. Based on the modular scheme, the results of the experiment on changing the air inside the solar house and the outdoor temperature are presented in the form of a graph. The mathematical model of the thermal balance of the building in dynamic mode and the obtained calculation results are recommended for use in the development of energy-efficient solar houses

Математическое моделирование комбинированной системы теплоснабжения солнечного дома)

Today, increasing energy efficiency in residential heating systems, saving fuel and energy resources, and improving the efficiency of using devices based on renewable energy sources is an urgent issue. The purpose of the article is to develop a mathematical model of the heat balance and conduct a theoretical study of one-story rural houses based on the use of solar energy in a non-stationary mode. To achieve this goal, an experimental one-story solar house with autonomous heat supply was built. The heat supply of the experimental solar house mainly uses solar energy, and when the heat supply load exceeds this load, the traditional boiler device is used. The power supply of the experimental solar house is provided by a solar panel (photovoltaic converter). A heat balance scheme for a solar house with autonomous heat supply and an electrothermal scheme of a physical model are proposed. Based on the proposed schemes, a mathematical model of heat balance and a calculation algorithm based on the heat balance equation of the dynamic state of the heat supply system of a one-story experimental solar house in a non-stationary mode have been developed. On the basis of mathematical modeling, the influence of the heat capacity of the wall structure on the temperature regime of the building was studied. On the basis of the MATLAB-Simulink program, the main temperature characteristics were built, on which the change in the temperature of the internal air of the building was analyzed depending on the ambient temperature. On the basis of the program, a modular scheme of the dynamic model was built. Based on the modular scheme, the results of the experiment on changing the air inside the solar house and the outdoor temperature are presented in the form of a graph. The mathematical model of the thermal balance of the building in dynamic mode and the obtained calculation results are recommended for use in the development of energy-efficient solar houses.Вопросы экономии топливно-энергетических ресурсов, повышения эффективности систем теплоснабжения жилых помещений, а также использования устройств на основе возобновляемых источников энергии на сегодняшний день имеют особую актуальность. Цель статьи – разработать математическую модель теплового баланса и провести теоретическое исследование одноэтажных сельских домов, использующих солнечную энергию в нестационарном режиме. Для ее реализации построен экспериментальный одноэтажный солнечный дом с автономным теплоснабжением на основе преимущественно солнечной энергии. В случаях, если нагрузка на теплоснабжение превышает солнечную нагрузку, применяется традиционное котельное устройство. Электроснабжение экспериментального дома обеспечивается солнечной панелью (фотоэлектрическим преобразователем). Предложены схема теплового баланса солнечного дома с автономным теплоснабжением и электротепловая схема физической модели. На их основе разработаны математическая модель и алгоритм расчета, базирующийся на уравнении теплового баланса динамического состояния системы теплоснабжения экспериментального дома в нестационарном режиме. Исследовано влияние теплоемкости стеновой конструкции на температурный режим здания. В среде моделирования MATLAB-Simulink построены основные температурные характеристики, на которых проанализировано изменение температуры внутреннего воздуха здания в зависимости от температуры окружающей среды. Построена модульная схема динамической модели, результаты эксперимента по изменению воздуха внутри солнечного дома и температуры наружного воздуха представлены в виде графика. Математическая модель теплового баланса здания в динамическом режиме и результаты расчетов могут использоваться при разработке энергоэффективных солнечных домов

ЛЕЧЕНИЕ ГИПЕРВОЛЕМИИ МАЛОГО КРУГА ПОСЛЕ ОПЕРАЦИИ РАСТЕЛЛИ У БОЛЬНОЙ С ТЕТРАДОЙ ФАЛЛО И АТРЕЗИЕЙ ЛЕГОЧНОЙ АРТЕРИИ

17yearold patient with hypervolemia of lesser (pulmonary) circulation was operated for tetralogy of Fallout with pulmonary atresia. She was successfully treated by intensive therapy using techniques of noninvasive ventilation with regard to clinical status of hypovolemia of the lesser (pulmonary) circulatory system in the early post operative period.Пациентка, 17 лет, была оперирована по поводу тетрады Фалло с атрезией легочной артерии. В раннем послеоперационном периоде наблюдалась клиника гиперволемии малого круга кровообращения. После проведения интенсивной терапии с применением методов неинвазивной вентиляции легких пациентка в удовлетворительном состоянии переведена из ОРИТ на 5е сутки

Efficacy of Videoendoscopic Inguinal Femoral Lymphadenectomy for Management of Metastatic Skin Melanoma

Aim. Assessment of the utility and advantage of videoendoscopic inguinal femoral lymphadenectomy (VE-LAD) over the standard open technique (OLAD) in patients with malignant skin melanoma and metastatic lesions of regional inguinal and/or femoral lymph nodes.Materials and methods. The Saint-Petersburg Clinical Research Centre for Specialty Medical Aid in Oncology managed 86 inguinal femoral LADs in melanoma patients over 2013–2016. VE-LAD was rendered in 48 (54.7 %) cases, and OLAD otherwise.Results and discussion. A total of 72 patients were included in the study. VE-LAD was performed in 48 (54.7 %) cases, and OLAD otherwise. An average VE-LAD duration was 90 (60 to 160) min. Severe complications were observed in 4/48 (8 %) VE-LAD and 16/24 (66 %) OLAD cases, which reveals a significantly lower complication rate in the study cohort (chi-square p > 0.000). Lymphorrhoea was shorter in the study cohort (> 7 days in 5 patients vs. 3/24 and > 14 days only in 11/24 OLAD cases; chi-square p > 0.000). No significant differences in relapse-free survival were observed between the cohorts, with higher absolute values of 22.6 months in the VE-LAD (95 % CI 14.8–30.4, p = 0.087) vs. 9.4 months (95 % CI 0.0–18.9, p = 0.087) in OLAD cohort. A median OS was 52.3 months (95 % CI 30.5–74.1, p = 0.996) in the VE-LAD vs. 39.9 months (95 % CI 30.6–49.2, p = 0.996) in OLAD cohort.Conclusion. Videoendoscopic inguinal femoral lymphadenectomy allows a radical inguinal femoral lymph node removal alike in conventional surgical dissection. Our results indicate the method performance towards reduced postoperative wound complications. The oncological indicators are comparable to the traditional surgery cohort