Integral Glass Encapsulation for Solar Arrays

Work reported was performed during the period from August 1977 to December 1978. The program objective was to continue the development of electrostatic bonding (ESB) as an encapsulation technique for terrestrial cells. Economic analyses shows that this process can be a cost-effective method of producing reliable, long lifetime solar modules. When considered in sufficient volume, both material and equipment costs are competitive with conventional encapsulation systems. In addition, the possibility of integrating cell fabrication into the encapsulation process, as in the case of the preformed cell contacts discussed in this report, offers the potential of significant overall systems cost reduction

High efficiency GaAs-Ge tandem solar cells grown by MOCVD

High conversion efficiency and low weight are obviously desirable for solar cells intended for space applications. One promising structure is GaAs on Ge. The advantages of using Ge wafers as substrates include the following: they offer high efficiency by forming a two-junction tandem cell; low weight combined with superior strength allows usage of thin (3 mil) wafers; and they are a good substrate for GaAs, being lattice matched, thermal expansion matched, and available as large-area wafers

Strengthening public health systems: Assessing the attributes of the NSW influenza surveillance system

© 2016 Dawson et al. Objective: In New South Wales (NSW), influenza surveillance is informed by a number of discrete data sources, including laboratories, emergency departments, death registrations and community surveillance programs. The purpose of this study was to evaluate the NSW influenza surveillance system using the US Centers for Disease Control and Prevention guidelines for evaluating public health surveillance systems. Importance of study: Having a strong influenza surveillance system is important for both seasonal and pandemic influenza preparedness. The findings will inform recommendations for strengthening surveillance in NSW. Methods: The scope was limited to all sources included in the NSW Health Influenza Report in 2012-13. To assess the performance of the system, in-depth interviews (N = 21) were conducted with key stakeholders and thematically analysed. Respiratory testing data gathered through the sentinel laboratories in 2012 were used to estimate sensitivity, and laboratory notifications were analysed to assess timeliness and representativeness. Key documents - including reports, guidelines, correspondence and meeting minutes - were also reviewed, providing a method of triangulation. Results: The NSW influenza surveillance system integrates multiple sources of surveillance of influenza and influenza-like illness to provide a comprehensive picture of influenza in the community. Despite its structural complexity, the system delivers quality, timely and relevant data to inform a range of public health activities, and the NSW Health Influenza Report is well regarded by stakeholders. Challenges include managing system complexity, key person risk and cross-jurisdictional issues. Stakeholders commented that system flexibility would depend on additional resourcing. Although the sensitivity of sentinel laboratory surveillance was estimated as 1-25%, depending on the time of year, understanding sensitivity remains a challenge in influenza surveillance where the true incidence of infection is unknown. Conclusion: Influenza surveillance is critical for monitoring virological changes, understanding disease epidemiology and informing public health responses. The system was found to deliver timely and good-quality surveillance information. Additional value could be achieved by increasing flexibility and stability, automating systems (where possible) and formalising processes of data acquisition. The system continues to negotiate a number of constraints, including complexity and cross-jurisdictional issues, which are ongoing obstacles to realising some potential system improvements

Effects of Na2S and (NH4)2S edge passivation treatments on the dark current-voltage characteristics of GaAs pn diodes

We have investigated the dark current-voltage characteristics of GaAs pn homojunctions whose surfaces have been passivated with NuzS and (NH4)2S chemical treatments. Reductions in 2kTpcrimeter recombination currents by a factor of 3.2 were obtained for the two treatments. A shunt leakage, observed at low forward bias for the NazS treated devices, is virtually eliminated with the {NH4hS treatment. It is also shown that even the high quality, large area (0.25 cm1 ) pn diodes used in this study are dominated by 2kTedge currents before passivation

Financial Transaction Tax: Small is Beautiful

The case for taxing financial transactions merely to raise more revenues from the financial sector is not particularly strong. Better alternatives to tax the financial sector are likely to be available. However, a tax on financial transactions could be justified in order to limit socially undesirable transactions when more direct means of doing so are unavailable for political or practical reasons. Some financial transactions are indeed likely to do more harm than good, especially when they contribute to the systemic risk of the financial system. However, such a financial transaction tax should be very small, much smaller than the negative externalities in question, because it is a blunt instrument that also drives out socially useful transactions. There is a case for taxing over-the-counter derivative transactions at a somewhat higher rate than exchange-based derivative transactions. More targeted remedies to drive out socially undesirable transactions should be sought in parallel, which would allow, after their implementation, to reduce or even phase out financialtransaction taxes

Probing 5f-state configurations in URu2Si2 with U L3-edge resonant x-ray emission spectroscopy

Resonant x-ray emission spectroscopy (RXES) was employed at the U L3 absorption edge and the La1 emission line to explore the 5f occupancy, nf, and the degree of 5f orbital delocalization in the hidden order compound URu2Si2. By comparing to suitable reference materials such as UF4, UCd11, and alpha-U, we conclude that the 5f orbital in URu2Si2 is at least partially delocalized with nf = 2.87 +/- 0.08, and does not change with temperature down to 10 K within the estimated error. These results place further constraints on theoretical explanations of the hidden order, especially those requiring a localized f2 ground state.Comment: 11 pages,7 figure

Effects of Heavy Impurity Doping on Electron Injection in p+-n GaAs Diodes

Measurements of electron injection currents in p+‐n diodes are presented for a range of p‐type dopant concentrations. A successive etch technique was used to characterize the electron injection current in terms of the product (noDn). Measurements are presented for Zn‐doped GaAs solar cells with p‐layer hole concentrations in the range 6.3×1017−1.3×1019 cm−3. The results demonstrate that so‐called band‐gap narrowing effects substantially increase the injected electron current in heavily doped p‐type GaAs. These heavy doping effects must be accounted for in the modeling and design of GaAs solar cells and heterostructure bipolar transistors

Current-voltage characteristics of quasi-one-dimensional superconductors: An S-curve in the constant voltage regime

Applying a constant voltage to superconducting nanowires we find that its IV-characteristic exhibits an unusual S-behavior. This behavior is the direct consequence of the dynamics of the superconducting condensate and of the existence of two different critical currents: j_{c2} at which the pure superconducting state becomes unstable and j_{c1}<j_{c2} at which the phase slip state is realized in the system.Comment: 4 pages, 5 figures, replaced with minor change