GaSb photovoltaic cells for applications in TPV generators

GaSb thermophotovoltaic (TPV) cells are one of the reasons for the renewed interest in TPV technology. Today, they are the most suitable choice for modem TPV generators. This paper reviews the background and the status of the GaSb photovoltaic cell development. GaSb TPV cells are fabricated either by a zinc vapour diffusion technology or by epitaxial methods such as liquid phase epitaxy or metal-organic vapour phase epitaxy. Efficiencies of more than 30% under filtered blackbody spectra were reported

Cascade three-component composition on polystyrene basis absorbing in visible range and emitting in near IR

Design results have been presented for a three-component composition for solar energy conversion into the sensitivity range of Si and GaAs photocells based on polystyrene and polycyclic aromatic organic luminescent compounds. Two possible approaches to selection of concentrations of the components oriented to provide the maximum collection efficienc y of the visible range solar radiation and the optimum conditions of the Foerster non-radiative energy transfer between the intermediate and final components of the cascade compo -sition have been shown to give comparable results and thus do not form an alternative to one another.Представлены результаты дизайна трехкомпонентной композиции для преобразования энергии солнечного излучения в интервал чувствительности Si и GaAs фотоэлементов на основе полистирола и ароматических полициклических органолюминофоров. Показано, что два возможных подхода к подбору концентраций компонентов, ориентированные на обеспечение максимально эффективного сбора излучения в видимом диапазоне и оптимальных условий Ферстеровского безызлучательного переноса энергии между промежуточными и конечными компонентами каскадной композиции, дают сравнимые результаты и, таким образом, не являются альтернативой друг другу.Представлено результати дизайну трьохкомпонентної композиції для конвертування енергії сонячного випромінювання в інтервал чутливості Si та GaAs фотоелементів на основі полістиролу та ароматичних поліциклічних органічних люмінофорів. Показано, що два підходи до добору концентрацій компонентів, орієнтовані на забезпечення максимально ефективного збирання випромінювання у видимому діапазоні і оптимальних умов Ферстерівського безвипромінювального переносу енергії між проміжними та кінцевими компонентами каскадної композиції, дають порівняні результати і, отже, не є альтернативою один одному

Some clinical factors of aseptic instability of the knee joint endoprosthesis

Background. Conducting clinical studies to determine the factors determining the aseptic instability of knee joint endoprosthesis components is an urgent issue in modern orthopedics. The aim of the study was to determine some clinical factors of aseptic instability of knee joint endoprosthesis components. Materials and methods. Comprehensive research was conducted on 285 patients who underwent primary knee arthroplasty between 2010 and 2021, including 85 patients with clinical and radiological signs of aseptic instability of knee arthroplasty components (AIKAC). Also, 200 patients made up a control group with no signs of AIKAC instability observed. Clinical research methods included general, and special orthopedic methods of studying local changes in the knee joint. They included measurement of body mass index (BMI), overloading of the knee joint due to work, previous surgical interventions and early postoperative complications of primary arthroplasty, and presence of angular deformities in the knee joint. For the clinical assessment of the knee joint of patients after knee arthroplasty, we used our own point assessment of the state of the knee joint. Results. It was determined that significant factors for the development of instability of components of the knee joint endoprosthesis are both directly related to the patient (increase in BMI, difficult working conditions, the presence of operative interventions on the knee joint), and factors related to errors du­ring the primary total arthroplasty (residual deformities of the knee joint and early postoperative complications). Conclusions. We determined important factors of aseptic instability of the knee joint in the patients after arthroplasty. Taking into account the results of this study will improve the diagnosis and treatment of aseptic instability of the knee joint

High-throughput two-melt LPE fabrication of AlGaAs/GaAs solar cells

A new type of combined (piston and slider) boat was designed. The new boat allows to use several substrates, two different melts and to regulate precisely the level of the melt under- or supersaturation. The possibility of untraditional acceptor dopants (Mg, Ge) using for LPE-grown AlGaAs/GaAs solar cells is discussed