Influence of Na on the properties of Cu-rich prepared CuInS2 thin films and the performance of corresponding CuInS2/CdS/ZnO solar cells

Using different glass substrate types the Na content in sequentially and Cu-rich prepared CuInS₂ films and corresponding CuInS₂/CdS/ZnO thin-film solar cells is varied. The purpose was to investigate the influence of different Na concentrations on absorbers and devices. While the morphology of the absorbers seems not to be affected by this variation, corresponding PL spectra differ significantly. The properties of the solar cells, however, show no dependence on the Na concentration. This implies that even though the defect chemistry of CuInS₂, sequentially prepared under Cu excess, is changed by the presence of Na this influence has no impact on properties of corresponding solar cells.     

Crisis intervention after the suicide of a teacher.

Educational institutions increasingly are requesting the services of mental health professionals after a suicide has occurred. Although such communities have sustained sudden shock and loss, the contagious quality of suicide results in uncertainty about the most appropriate response. We describe an intervention occurring after the suicide of an elementary school teacher. The intervention included a meeting with faculty, classroom discussions with the students most directly affected, and the availability of the school psychologist for individual meetings. In addition, a memorial service was held at the school. We argue that such a broad, multifaceted response contributes to the healing process and serves to minimize mental health difficulties after such an event. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development and analysis — an intergrated approach

Due to the growing complexity and size of software systems, the development of correct and easy to maintain software has become more and more of a problem. This is especially true for distributed systems with real-time requirements. Therefore, great efforts have been made to overcome this problem. However, most approaches either do not consider every aspect of interest or are restricted to only one development phase. This paper describes OASIS, an open environment, that allows the integration of different analysis techniques in different system development phases, and presents the existing OASIS-toolset, that is already incorporated in this environment.     

Investigations of a Superconducting Beam Tube Niobium Cavity at S-Band

The influence of several surface preparation techniques like electropolishing, chemical edging, anodizing and UIIV-heat treatment on both the Q-value and the peak RF fields have been studied in a welded S-band cavity having large beam tubes. Peak magnetic fields up to 650 Oe at a Q-value of 8×1010 in the TE011-mode and peak surface electric fields of 25 MV/m at Q = 7×109 in the TM010-mode have been obtained. Simultaneous measurements of the mean free path in the surface layer of the cavity permit to calculate Hc1. The results indicate that Hc1 is no limitation for the magnetic fields achievable in RF-cavities. This makes type-II-superconductors like Nb3Sn interesting for practical applications at high frequencies.     

Low temperature laser scanning microscopy of a superconducting radio-frequency cavity

An apparatus was developed to obtain, for the first time, 2D maps of the surface resistance of the inner surface of an operating superconducting radio-frequency niobium cavity by a low-temperature laser scanning microscopy technique. This allows identifying non-uniformities of the surface resistance with a spatial resolution of about 2.4 mm and surface resistance resolution of ~1 μΩ at 3.3 GHz. A signal-to-noise ratio of about 10 dB was obtained with 240 mW laser power and 1 Hz modulation frequency. The various components of the apparatus, the experimental procedure and results are discussed in detail in this contribution.     

Portable radio antenna performance in the 150, 450, 800, and 900MHz bands `outside' and in-vehicle

Portable radio antenna performance on the human body was measured for several different radio models in the 150, 450, 800, and 900 MHz. bands. In-vehicle measurements were made at an outdoor antenna range equipped with a vehicle turntable. All other measurements were made in an anechoic chamber. Tests were made at the head level, at the side-level swivel-type carry case, at the side-level belt-loop type carry case, and at the shoulder level with a speaker microphone antenna. A statistical analysis was made of the data for use in coverage propagation predictions, and system designs. The results of the statistical analysis are presented     

Applying MDD in the content management system domain

Software and Systems Modeling - Content management systems (CMSs) such as Joomla and WordPress dominate today’s web. Enabled by standardized extensions, administrators can build powerful web...     

Measurements of superconducting Nb3Sn cavities in the GHz range

Superconducting Nb3Sn Cavities have potential advantages over rf cavities with Nb surfaces To test possible applications and to improve the understanding of Nb3Sn coatings on Nb, rf cavities have been measured between 1.5 and 8K and between 0.1 and 7GHz. The temperature dependence of the surface resistance R(T) indicates weak superconducting spots with transition temperaturesTmin{c}max{ast} < 1K andTmin{c}max{ast} simeq 2.5K. The normal conducting spotsTmin{c}max{ast} lsim 1K cause the large rf residual lossesR'_{res} propto f^{2}observed up to date. The spots withTmin_{c}max_{ast} simeq 2.5K cause temperature dependences ofR'(T)between 2 and 6K, where RBCS(Nb3Sn) is still negligible. In line withR_{res} propto f^{2}, the lowest rf lossesR_{res} < 2.10^{-9}Omegaand the highest field strengthB_{crit} = 83 m^{T}(wedgeE_{peak} = 29have been observed at the lowest frequency 0.1GHz measured. Surface resistance and penetration depth measurements have shown that grain boundaries or hydrogen clusters do not cause the weak spots observed withTmin{c}max{ast} < 2.5K. The origin and the chemistry of the weak spots withTmin{c}max{ast} lsim 1K, which cause the largeR_{res} propto f^{2}and the lowB_{crit} (T) simeq const, are still not clear. They seem related to the Nb3Sn surface. The weak spots withTmin{c}max{ast} simeq 2.5K consist most likely of Nb6Sn5, which in cooling below 950°C precipitates due to the excess Sn present in Nb3Sn coatings grown in Sn vapor.