Experimental Charging Behavior of Orion UltraFlex Array Designs

The present ground based investigations give the first definitive look describing the charging behavior of Orion UltraFlex arrays in both the Low Earth Orbital (LEO) and geosynchronous (GEO) environments. Note the LEO charging environment also applies to the International Space Station (ISS). The GEO charging environment includes the bounding case for all lunar mission environments. The UltraFlex photovoltaic array technology is targeted to become the sole power system for life support and on-orbit power for the manned Orion Crew Exploration Vehicle (CEV). The purpose of the experimental tests is to gain an understanding of the complex charging behavior to answer some of the basic performance and survivability issues to ascertain if a single UltraFlex array design will be able to cope with the projected worst case LEO and GEO charging environments. Stage 1 LEO plasma testing revealed that all four arrays successfully passed arc threshold bias tests down to -240 V. Stage 2 GEO electron gun charging tests revealed that only the front side area of indium tin oxide coated array designs successfully passed the arc frequency test

Experimental Tests of UltraFlex Array Designs in Low Earth Orbital and Geosynchronous Charging Environments

The present ground based investigations give the first definitive look describing the expected on-orbit charging behavior of Orion UltraFlex array coupons in the Low Earth Orbital and Geosynchronous Environments. Furthermore, it is important to note that the LEO charging environment also applies to the International Space Station as well as to the lunar mission charging environments. The GEO charging environment includes the bounding case for all lunar orbital and lunar surface mission environments. The UltraFlex thin film photovoltaic array technology has been targeted to become the sole power system for life support and on-orbit power for the manned Aires Crew Exploration Vehicle. It is therefore, crucial to gain an understanding of the complex charging behavior to answer some of the basic performance and survivability issues in an attempt to ascertain that a single UltraFlex array design will be able to cope with the projected worst case LEO and GEO charging environments. Testing was limited to four array coupons, two coupons each from two different array manufactures, Emcore and Spectrolab. The layout of each array design is identical and varies only in the actual cell technology used. The individual array cells from each manufacturer have an antireflection layered coating and come in two different varieties either uncoated (only AR coating) or coated with a thin conducting ITO layer. The LEO Plasma tests revealed that all four coupons passed the arc threshold -120 V bias tests. GEO electron gun charging tests revealed that only front side area of ITO coated coupons passed tests. Only the Emcore AR array passed backside Stage 2 GEO Tests

Electrical Breakdown of Anodized Structures in a Low Earth Orbital Environmental

A comprehensive set of investigations involving arcing on a negatively biased anodized aluminum plate immersed in a low density argon plasma at low pressures (P(sub O), 7.5 x 10(exp -5) Torr) have been performed. These arcing experiments were designed to simulate electrical breakdown of anodized coatings in a Low Earth Orbital (LEO) environment. When electrical breakdown of an anodized layer occurs, an arc strikes, and there is a sudden flux of electrons accelerated into the ambient plasma. This event is directly followed by ejection of a quasi-neutral plasma cloud consisting of ejected material blown out of the anodized layer. Statistical analysis of plasma cloud expansion velocities have yielded a mean propagation velocity, v = (19.4 +/- 3.5) km/s. As the plasma cloud expands into the ambient plasma, energy in the form of electrical noise is generated. The radiated electromagnetic noise is detected by means of an insulated antenna immersed in the ambient plasma. The purpose of the investigations is (1) to observe and record the electromagnetic radiation spectrum resulting from the arcing process. (2) Make estimates of the travel time of the quasi-neutral plasma cloud based on fluctuations to several Langmuir probes mounted in the ambient plasma. (3) To study induced arcing between two anodized aluminum structures in close proximity

The Conductor-Dielectric Junctions in a Low Density Plasma

A conductor-dielectric junction exposed to the space environment is a frequent spacecraft design feature. Due to spacecraft charging and/or solar array operation, the conductor can acquire a high potential with respect to the surrounding plasma. If this potential is positive the insulators adjacent to exposed conductors can collect current as if they were conductors themselves. This phenomenon, called snapover, results in a substantial increase in current collection, and may even result in a glow discharge if the potential is high enough. If a conductor has a negative potential, arcing can occur at the site of a junction. Both of these phenomena negatively affect spacecraft operation. To prevent negative consequences, the physical mechanisms of snapover and arc inception require investigation. In this paper, results are presented of an experimental and theoretical study of snapover, glow discharge, and arc phenomena for different materials immersed in argon or xenon plasmas. The effect of snapover is investigated for several metal-dielectric junctions: copper-teflon, copper-Kapton, copper-glass, aluminum-teflon, aluminum-Kapton, steelteflon, anodized aluminum with pinholes, and copper-ceramics. I-V curves are measured and snapover inception voltages, essential parameters (increase in current and collection area due to secondary electrons), and glow discharge inception thresholds are determined. Optical spectra are obtained for glow discharges in both argon and xenon plasmas. These spectra provide information regarding atomic species entrapped in the glow region. Some spectral lines can be used to estimate plasma parameters in the discharge area. A videocamera and linear array were used to confirm that snapover inception is accompanied by very low intensity visible light emission. This result seems to be important for the estimate of the light pollution around spacecraft. Optical spectra (wavelengths 380-650 nm) of arcs are also obtained on a negatively biased chromic acid anodized aluminum plate immersed in low density argon and xenon plasmas. Analysis of these spectra confirms our earlier findings that aluminum atoms are ejected from the arc site. Moreover, it is found that chromium atoms are also quite abundant in the arc plasma. It is believed that the latter results contribute considerably to the understanding of processes of plasma contamination caused by arcing

A Comprehensive Study of Dielectric-Conductor Junctions in Low Density Plasmas

In this paper, results are presented of an experimental and theoretical study of snapover, glow discharge, and arc phenomena for different materials immersed in argon or xenon plasmas. The effect of snapover is investigated for several metal-dielectric junctions: copper-teflon, copper-Kapton, copper-glass, aluminum-teflon, aluminum-Kapton, steel-teflon, anodized aluminum with pinholes, and copper-ceramics. I-V curves are measured, and snapover inception voltages, essential parameters (increase in current and collection area due to secondary electrons), and glow discharge inception thresholds are determined. Optical spectra are obtained for glow discharges in both argon and xenon plasmas. These spectra provide information regarding atomic species entrapped in the glow region. A video-camera and linear array were used to confirm that snapover inception is accompanied by very low intensity visible light emission. This result seems to be important for the estimate of the light pollution around spacecraft. Optical spectra (wavelengths 380-650 nm) of arcs are also obtained on a negatively biased chromic acid anodized aluminum plate immersed in low density argon and xenon plasmas. Analysis of these spectra confirms our earlier findings that aluminum atoms are ejected from the arc site. Moreover, it is found that chromium atoms are also quite abundant in the arc plasma. It is believed that the latter results contribute considerably to the understanding of processes of plasma contamination caused by arcin

Prediction of exacerbation chronic bronchopulmonary diseases in children with influenza

The objective: To develop a method for predicting exacerbation of chronic illness in children with asthma and cystic fibrosis, patients with influenza, based on the study of the dynamics of cytokines. Materials and methods: Were examined 52 patients with bronchial asthma and 45 children with cystic fibrosis at the age from 1 year to 12 years, located in infectious pulmonary Department at the planned treatment of underlying pathology, in which influenza was in-hospital infection. Control group observations included 40 patients with the flu, without concomitant pulmonary disease. The etiology of viral infection was established by detection of viral RNA in nasopharyngeal swabs by PCR. Among the influenza viruses were identified influenza АH1N1, АH3N2, influenza B, and in 2009–2010 the predominant antigen was the pandemic influenza virus АH1N1pdm09. Determination of the concentration of serum interleukins IL-1β, IL-4, IL-8, IL-10, ТNF-α, IFN-γ was performed in the 1st and 3rd day of hospitalization cytokines by the solid-phase immune-enzyme assay. Analysis of the results performed using statistical package SPSS 17.0 EN for Windows. Results: The flu caused the aggravation associated bronchopulmonary pathology in 2/3 of children, as MV patients, and patients with BA (65,4%-66,7%, respectively). With an increase of the ratio of IL-4 / IFN-γ and IL-10/IFN-γ, at least 5-6 times, influenza can be considered a trigger of exacerbation of chronic bronchopulmonary pathologies that require amplification of the therapy of bronchial asthma and of сystic fibrosis. The growth of prognostic coefficients in 2-3 times allows using for treatment of influenza in these patients only antiviral agents. Conclusion: The study has shown a method for predicting exacerbation of bronchial asthma and cystic fibrosis in children at an early stage of influenza by calculating the ratio of IL-4/IFN-γ and IL-10/IFN-γ in children aged from 1 year to 12 years

Прогнозирование обострения хронических бронхолёгочных заболеваний при гриппе у детей

The objective: To develop a method for predicting exacerbation of chronic illness in children with asthma and cystic fibrosis, patients with influenza, based on the study of the dynamics of cytokines. Materials and methods: Were examined 52 patients with bronchial asthma and 45 children with cystic fibrosis at the age from 1 year to 12 years, located in infectious pulmonary Department at the planned treatment of underlying pathology, in which influenza was in-hospital infection. Control group observations included 40 patients with the flu, without concomitant pulmonary disease. The etiology of viral infection was established by detection of viral RNA in nasopharyngeal swabs by PCR. Among the influenza viruses were identified influenza АH1N1, АH3N2, influenza B, and in 2009–2010 the predominant antigen was the pandemic influenza virus АH1N1pdm09. Determination of the concentration of serum interleukins IL-1β, IL-4, IL-8, IL-10, ТNF-α, IFN-γ was performed in the 1st and 3rd day of hospitalization cytokines by the solid-phase immune-enzyme assay. Analysis of the results performed using statistical package SPSS 17.0 EN for Windows. Results: The flu caused the aggravation associated bronchopulmonary pathology in 2/3 of children, as MV patients, and patients with BA (65,4%-66,7%, respectively). With an increase of the ratio of IL-4 / IFN-γ and IL-10/IFN-γ, at least 5-6 times, influenza can be considered a trigger of exacerbation of chronic bronchopulmonary pathologies that require amplification of the therapy of bronchial asthma and of сystic fibrosis. The growth of prognostic coefficients in 2-3 times allows using for treatment of influenza in these patients only antiviral agents. Conclusion: The study has shown a method for predicting exacerbation of bronchial asthma and cystic fibrosis in children at an early stage of influenza by calculating the ratio of IL-4/IFN-γ and IL-10/IFN-γ in children aged from 1 year to 12 years. Цель: разработать способ прогнозирования обострения основного заболевания при гриппе у детей, больных бронхиальной астмой и муковисцидозом, на основании изучения динамики цитокинов. Материалы и методы: обследованы 52 пациента с бронхиальной астмой и 45 детей с муковисцидозом в возрасте от 1 года до 12 лет, находившихся в инфекционно-пульмонологическом отделении на плановом лечении основной патологии, у которых грипп являлся госпитальной инфекцией. Контрольную группу наблюдений составили 40 пациентов с гриппом, но без сопутствующих бронхолегочных заболеваний. Этиология вирусной инфекции устанавливалась определением вирус-специфической РНК в носоглоточных смывах методом ПЦР. Среди вирусов гриппа определялись АH1N1, АH3N2, В, а в 2009–2010 гг. преобладающим антигеном являлся вирус пандемического гриппа АH1N1pdm09. Определение содержания в сыворотке крови интерлейкинов IL-1β, IL-4, IL-8, IL-10, ТNF-α, IFN-γ проводилось в 1-й и 3-й день госпитализации «сэндвич»-методом твердофазного иммуноферментного анализа. Статистическая обработка результатов выполнена с применением программы SPSS 17.0 RU for Windows. Результаты: грипп вызывал обострение сопутствующей бронхолегочной патологии у большинства детей, больных как муковисцидозом, так и бронхиальной астмой (65,4% и 66,7% соответственно). При увеличении коэффициента соотношения IL-4/IFN-γ и IL-10/IFN-γ как минимум в 5–6 раз грипп может считаться триггером обострения сопутствующей хронической бронхолегочной патологии. Нарастание прогностических коэффициентов в 2–3 раза позволяет ограничить лечение гриппа у данной категории больных противовирусными средствами. Заключение: представлен способ прогнозирования обострения бронхиальной астмы и муковисцидоза у детей на ранней стадии гриппа с помощью расчета коэффициентов соотношения IL-4/IFN-γ и IL-10/IFN-γ у детей в возрасте от 1 года до 12 лет.

System of forming control signals by correction devices with creation of neural network patterns based on matrix analysis

The compensating devices are controlled in the structure of the automatic control system in conjunction with the sensors included in a particular node of the power grid. But the overall state of the local power grid for the reactive power flow is not considered. It is proposed to generate control signals to correction devices by processing the information obtained by monitoring from remote sensors of voltage and current of the distribution grid. It is possible to use the matrix method of forming the control signals to correction devices to adjust the grid parameters. To improve the energy efficiency of correction devices in the monitoring structure, it is proposed to use static reactive power compensators (SVCs) based on magneto-valve elements. The proposed distribution grid monitoring structure with the transfer of information over a local area network from sensors to correction devices makes it possible to stabilize the required grid parameters among consumers and minimize the loss of electrical energy from reactive power flow