For many years, real-time OS-based applications have been used in embedded special-purpose systems. Recently they have been used everywhere, from on-board control systems for aircraft, to household ...appliances. The development of multiprocessor computing systems usually aims to increase either the level of reliability or the level of system performance to values that are inaccessible or difficult to implement in traditional computer systems. In the first case, the question of the availability of special means of ensuring the fault tolerance of computer systems arises, the main feature (and advantage) of which is the absence of any single resource, failure of which leads to a fatal failure of the entire system. The use of a real-time operating system is always associated with equipment, with an object and with events occurring at an object. A real-time system, as a hardware-software complex, includes sensors that record events at an object, input / output modules that convert sensor readings into a digital form suitable for processing these readings on a computer, and finally, a computer with a program that responds to events occurring at the facility. The RTOS is focused on processing external events. It is this that leads to fundamental differences (compared with general-purpose OS) in the structure of the system as well as in the functions of the kernel and in the construction of the input-output system. The RTOS can be similar in its user interface to general-purpose operating systems, but it is completely different in its structure. In addition, the use of RTOS is always specific. If users (not developers) usually perceive a general-purpose OS as a ready-made set of applications, then the RTOS serves only as a tool for creating a specific hardware-software complex in real time. Therefore, the widest class of users of RTOS is the developers of real-time complexes, people designing control and data collection systems. When designing and developing a specific real-time system, the programmer always knows exactly what events can occur at the facility, and he knows the critical terms for servicing each of these events. We call a real-time system (SRV) a hardware-software complex that responds in predictable times to an unpredictable stream of external events. The system must have time to respond to the event that occurred at the facility, during the time critical for this event. The critical time for each event is determined by the object and by the event itself, and, of course, it can be different, but the response time of the system must be predicted (calculated) when creating the system. Lack of response at the predicted time is considered an error for real-time systems. The system must have time to respond to simultaneously occurring events. Even if two or more external events occur simultaneously, the system must have time to respond to each of them during time intervals critical for these events. In this study, as part of a network fault-tolerant technology, the RTOS becomes a special type of control software that is used to organize the operation of embedded applications, which are characterized by limited memory resources, low productivity and the requirements of a guaranteed response time (T<4 μs), high level availability and availability of auto-monitoring facilities.
In the work the effect of the number of In0.8Ga0.2As stacked quantum dots (QDs) embedded in a single-junction GaAs solar cell (SC) on its photoelectric characteristics has been studied. A series of ...GaAs SC structures, which differed by a number of embedded QD layers, were grown using metalorganic vapor phase epitaxy. By analyzing the electroluminescence spectra and the current-voltage characteristics of the obtained structures the main reason for the voltage loss in SC with QDs has been established which is an increase in recombination through the QD levels with an increase the number of QD layers.
The results of studying the InxGa1−xAs laser power converters with the indium percentage of 18% and of 23% are presented. In the mode of 1064 nm laser radiation conversion the photovoltaic parameters ...dynamics with raising temperature is discussed.
In this work, physical and optical properties of In0.8Ga0.2As quantum dots (QDs) embedded in the structure of a single-junction GaAs solar cell (SC) grown by MOVPE technique were investigated using ...spectral characteristics of external quantum yield (EQE) and electroluminescence (EL). It has been found that, in characterizing QD physical parameters, simplified model of a thin stressed quantum well can be applied to a wetting layer (WL). It has been demonstrated that the EL spectra allows determining the absorption energy of photons in WL and QDs more accurately compared to the EQE spectra. Energies of "Ee-Ehh" and "Ee-Elh" transitions in WL have been determined and were 1.325 eV and 1.388 eV respectively. The calculated values of the WL thickness (5.63 Å) and In composition of QDs (xIn = 80%) coincide with the technological parameters used in the epitaxial growth of the device.
Патологія нервової системи пов’язана з низкою імунних процесів: деструктивні зміни в тканинах мозку контролюються імунною системою, а втрата регуляторних механізмів з боку ЦНС спричиняє імунні ...порушення.Мета дослідження – з’ясувати особливості імунних порушень залежно від варіанта перебігу віддаленого періоду черепно-мозкової (ЧМТ).Матеріали і методи. У 280 хворих із наслідками ЧМТ та 30 пацієнтів контрольної групи дослідили вміст основних субпопуляцій CD. Середній вік основної групи – (42,54±0,59) року, середній катамнез травми – (8,02±0,49) року. В 130 пацієнтів діагностували стаціонарний перебіг віддаленого періоду ЧМТ, 57 – із пароксизмальним та 93 – з прогресуючим. Неврологічний дефіцит оцінювали за шкалою NOS-TBI, когнітивний – за Монреальською шкалою когнітивного дефіциту (МоСА). Вміст основних субпопуляцій CD3+, CD4+, CD8+, CD22+, CD16+ - лімфоцитів дослідили методом проточної цитофлуориметрії (проточний цитофлюориметр Epics XL (“Beckman Coulter”, США).Результати досліджень та їх обговорення. Незалежно від варіанта перебігу травматичної хвороби головного мозку, вміст субпопуляцій лімфоцитів (CD3+, CD4+, CD8+ та CD22+) був достовірно нижчими, ніж у групі контролю (р<0,05). Значення імунорегуляторного індексу у пацієнтів усіх груп було нижчим за значення контролю, досягнувши мінімального – 1,68 у групі з пароксизмальним варіантом перебігу. За умови стаціонарного та пароксизмального перебігу віддаленого періоду легкої (ЧМТ) встановлено достовірну різницю (р=0,001) значень СD16+-лімфоцитів. Пацієнти з пароксизмальним перебігом наслідків травми середньогї тяжкості (СТЧМТ) мали нижчі значення CD4+ порівняно з групою прогресуючого перебігу (р=0,037). Для пароксизмального варіанта перебігу тяжкої (ТЧМТ), порівняно зі стаціонарним, було характерним достовірне (р=0,034) збільшення вмісту CD4+-лімфоцитів при достовірному (р=0,038) зменшенні вмісту СD22+-лімфоцитів. При прогресуючому перебігу наслідків ЛЧМТ уміст СD4+-лімфоцитів зростав при подовженні катамнезу травми (r=0,43, р=0,046), а рівень СD3+ – знижувався при вищих показниках тривожності (r=-0,50, р=0,018). У цій групі кореляції між МоСА-тестом та: СD3+ - r=0,46, р=0,032, СD4+ - r=0,48, р=0,025, СD8+ - r=0,53, р=0,012 вказують на негативний вплив імуносупресії на когнітивне функціонування.Висновок. У пацієнтів із наслідками ЧМТ встановлено достовірне (р<0,05) зниження рівня субпопуляцій: CD3+, CD4+, CD8+, CD22+ - лімфоцитів при зростанні CD16+ - лімфоцитів. За прогресуючого перебігу наслідків ЛЧМТ рівень СD4+ зростав із подовженням катамнезу травми, рівень СD3+ – знижувався при вищих показниках тривожності, а кореляції СD3+ СD4+, СD8+ з МоСА-тестом вказували на негативний вплив імуносупресії на когнітивне функціонування.
InAs and In
0.8
Ga
0.2
As quantum dots in a GaAs matrix as well as GaAs solar cells with quantum dots of both types in the
i
-region are obtained by metalorganic vapor-phase epitaxy. As a result of ...investigations by photoluminescence and transmission electron microscopy, it is found that the In
0.8
Ga
0.2
As quantum-dot array is highly uniform, contains a smaller number of large imperfect quantum dots, and also provides a decrease in mechanical stresses in the structure. An analysis of the spectral dependences of the internal quantum yield shows that the quality of a solar-cell matrix after embedding up to 20 rows of In
0.8
Ga
0.2
As quantum dots remains at a level close to the reference GaAs solar cells. In this case, a linear increase in the additional photocurrent generated due to the absorption of sub-bandgap photons in In
0.8
Ga
0.2
As quantum dots is provided with an increase in the number of rows of quantum dots, since the value of the photocurrent gain per row is preserved.
Metamorphic Ga
0.76
In
0.24
As heterostructures for photovoltaic converters are grown by the MOCVD (metal–organic chemical vapor deposition) technique. It is found that, due to the valence-band ...offset at the
p
-In
0.24
Al
0.76
As/
p
-In
0.24
Ga
0.76
As (wide-gap window/emitter) heterointerface, a potential barrier for holes arises as a result of a low carrier concentration in the wide-gap material. The use of an InAlGaAs solid solution with an Al content lower than 40% makes it possible to raise the hole concentration in the widegap window up ~9 × 10
18
cm
–3
and completely remove the potential barrier, thereby reducing the series resistance of the device. The parameters of an GaInAs metamorphic buffer layer with a stepwise In content profile are calculated and its epitaxial growth conditions are optimized, which improves carrier collection from the
n
-GaInAs base region and provides a quantum efficiency of 83% at a wavelength of 1064 nm. Optimization of the metamorphic heterostructure of the photovoltaic converter results in that its conversion efficiency for laser light with a wavelength of 1064 nm is 38.5%.
Pathology of the nervous system is related to different immune processes: destructive changes in tissues of the brain are controlled by the immune system and the loss of regulator mechanisms from the ...side of central nervous system causes immune disturbances. The aim of the study – to find out the pattern of immune disorders, in accordance with the course of remote period at traumatic brain injury (TBI). Materials and Methods. 280 patients with the consequences of TBI and 30 patients of control group were examined. We studied the content of CD subpopulations in them. The average age of the main group was (42.54±0.59) years, the average injury catamnesis was (8.02±0.49) years. In 130 patients, we diagnosed stationary course of the remote period, in 57 patients – paroxysmal and in 93 patients - progressive course of the remote period at TBI. Neurological deficit was evaluated by means of Neurological Outcome Scale for Traumatic Brain Injury (scale NOS-TBI), cognitive impairments were evaluated by means of Montreal scale for cognitive deficits (MoCA). We studied the content of CD subpopulations (CD3+, CD4+, CD8+, CD22+, CD16+) by flow cytometry (flow cytoflowmetry Epics XL («Beckman Coulter», USA). Results and Discussion. Regardless of the course of TBI, the content of subpopulations of lymphocytes (CD3+, CD4+, CD8+ and CD22+) was significantly lower compared with the control group (p<0,05). The immune regulative index values in patients of all groups were significantly lower compared with the control group, reaching a minimum (1.68) in the group with paroxysmal course of TBI. In case of stationary and paroxysmal course of remote period at mild TBI we found significant difference (p=0,001) of values of CD16+-lymphocytes. Patients with paroxysmal course of moderate TBI had significantly lower CD4+ values compared with a group that was characterized by progressive course of TBI (p=0.037). Paroxysmal course of severe TBI (compared with stationary one) was characterized by significant (p=0.034) increase of CD4+-lymphocytes on the background of significant (p=0.038) reduction of CD22+-lymphocytes. In case of progressive course of mild TBI the content of CD4+-lymphocytes increased with extension of catamnesis of TBI (r=0,43, p=0,046). The level of CD3+- declined at higher rates of anxiety (r=-0.50, p=0.018). In this group, the correlation between MoCA-test and: CD3+ - r=0.46, p=0.032, CD4+ - r=0.48, p=0.025, CD8+ - r=0.53, p=0.012. These results point to the negative impact of immunosuppression on cognitive functioning. Conclusions. The patients with TBI demonstrate significant (p<0.05) reduction of subpopulations: CD3+, CD4+, CD8+, CD22+ lymphocytes on the background of growth of CD16+- lymphocytes. At progressive course of mild TBI consequences the level of CD4+ levels increased with extension of catamnesis of TBI, the level of CD3+- declined at higher rates of anxiety. The correlation with MoCA-test pointed to the negative impact of immunosuppression on cognitive functioning.
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