Energy requirement for the production of silicon solar arrays

An assessment of potential changes and alternative technologies which could impact the photovoltaic manufacturing process is presented. Topics discussed include: a multiple wire saw, ribbon growth techniques, silicon casting, and a computer model for a large-scale solar power plant. Emphasis is placed on reducing the energy demands of the manufacturing process

Energy requirement for the production of silicon solar arrays

Photovoltaics is subject of an extensive technology assessment in terms of its net energy potential as an alternate energy source. Reduction of quartzite pebbles, refinement, crystal growth, cell processing and panel building are evaluated for energy expenditure compared to direct, indirect, and overhead energies

Nanoscale Defect Formation on InP(111) Surfaces after MeV Sb Implantation

We have studied the surface modifications as well as the surface roughness of the InP(111) surfaces after 1.5 MeV Sb ion implantations. Scanning Probe Microscope (SPM) has been utilized to investigate the ion implanted InP(111) surfaces. We observe the formation of nanoscale defect structures on the InP surface. The density, height and size of the nanostructures have been investigated here as a function of ion fluence. The rms surface roughness, of the ion implanted InP surfaces, demonstrates two varied behaviors as a function of Sb ion fluence. Initially, the roughness increases with increasing fluence. However, after a critical fluence the roughness decreases with increasing fluence. We have further applied the technique of Raman scattering to investigate the implantation induced modifications and disorder in InP. Raman Scattering results demonstrate that at the critical fluence, where the decrease in surface roughness occurs, InP lattice becomes amorphous.Comment: 18 pages, 9 figure

Prolastin, a pharmaceutical preparation of purified human α1-antitrypsin, blocks endotoxin-mediated cytokine release

BACKGROUND: α1-antitrypsin (AAT) serves primarily as an inhibitor of the elastin degrading proteases, neutrophil elastase and proteinase 3. There is ample clinical evidence that inherited severe AAT deficiency predisposes to chronic obstructive pulmonary disease. Augmentation therapy for AAT deficiency has been available for many years, but to date no sufficient data exist to demonstrate its efficacy. There is increasing evidence that AAT is able to exert effects other than protease inhibition. We investigated whether Prolastin, a preparation of purified pooled human AAT used for augmentation therapy, exhibits anti-bacterial effects. METHODS: Human monocytes and neutrophils were isolated from buffy coats or whole peripheral blood by the Ficoll-Hypaque procedure. Cells were stimulated with lipopolysaccharide (LPS) or zymosan, either alone or in combination with Prolastin, native AAT or polymerised AAT for 18 h, and analysed to determine the release of TNFα, IL-1β and IL-8. At 2-week intervals, seven subjects were submitted to a nasal challenge with sterile saline, LPS (25 μg) and LPS-Prolastin combination. The concentration of IL-8 was analysed in nasal lavages performed before, and 2, 6 and 24 h after the challenge. RESULTS: In vitro, Prolastin showed a concentration-dependent (0.5 to 16 mg/ml) inhibition of endotoxin-stimulated TNFα and IL-1β release from monocytes and IL-8 release from neutrophils. At 8 and 16 mg/ml the inhibitory effects of Prolastin appeared to be maximal for neutrophil IL-8 release (5.3-fold, p < 0.001 compared to zymosan treated cells) and monocyte TNFα and IL-1β release (10.7- and 7.3-fold, p < 0.001, respectively, compared to LPS treated cells). Furthermore, Prolastin (2.5 mg per nostril) significantly inhibited nasal IL-8 release in response to pure LPS challenge. CONCLUSION: Our data demonstrate for the first time that Prolastin inhibits bacterial endotoxin-induced pro-inflammatory responses in vitro and in vivo, and provide scientific bases to explore new Prolastin-based therapies for individuals with inherited AAT deficiency, but also for other clinical conditions

DESIGN OF A LOW POWER CARGO SECURITY DEVICE USING A MICROPOWER ULTRA-WIDEBAND IMPULSE RADAR

Each year, thousands of cargo containers are broken into during shipping, costing billions of dollars in lost and damaged goods. In addition to removing its contents, intruders can also add unwanted and dangerous materials to a container, posing a threat to National Security. The possibilities of cargo container break-ins require that the containers go through check points at which they are physically searched. These searches often require the opening of the container, unloading and inspecting all cargo, and then loading the container and resealing it. This is a long and costly process. Because of the high costs of break-ins and inspections, many security devices have been developed to ensure the safety and detect the tampering of cargo containers. Most of these mechanisms involve more intricate door locks and electronic seals that are able to add a degree of security to the containers. Other “smart” cargo security devices exist, which employ a variety of sensors to detect intrusion, however, none of the current solutions are reliable and practical enough to eliminate the necessity for frequent inspection of cargo containers. The shipping industry is in need of a reliable, unobtrusive, low-cost, low-effort cargo security device. Over the last two decades, Lawrence Livermore National Laboratory (LLNL) has been developing a micropower impulse radar capable of detecting objects and motion within a short to medium range. Due to its past uses for intrusion and motion detection, the LLNL micropower impulse radar is a top prospect for a sensor technology used in a cargo security device. This paper describes the design of a low-power, low-cost cargo security device which uses the LLNL micropower impulse radar for the detection of shipping container intrusions. With the evaluation of the impulse radar as well as various other sensors, a device was created which successfully detected intrusions over 98% of the time with the capability of lasting 5 to 6 months when powered by two AA batteries

Phase 2 of the Array Automated Assembly Task for the Low Cost Silicon Solar Array Project. Second quarterly report

Automation is the key factor in reaching the LSSA Project goal of 500 megawatts annual production at $0.50 per watt. Solarex is currently analyzing the potential for automating a particular process sequence. Assessment of the cell making steps for this sequence is nearly complete. For the steps analyzed so far there seems to be no technological barrier to reaching the LSSA Project goals. The cell making steps are reviewed individually. A review of the technology, a description of verification experiments, and an economic analysis are given for the process sequence of junction formation, metalligation, edge removal, and testing. (WHK

Phase 2 of the array automated assembly task for the low-cost Silicon Solar Array Project. Third quarterly report

The results of the continuing work done on the feasibility of manufacturing photovoltaic solar modules in a future automated production facility are documented. During this quarter, the verification of metallization and junction formation were completed, and the verification of interconnection and encapsulation of cells into modules was started

Parliament and reconstruction: a plea and a plan.

Mode of access: Internet

High Efficiency, High Density Terrestrial Panel

Terrestrial panels were fabricated using rectangular cells. Packing densities in excess of 90% with panel conversion efficiencies greater than 13% were obtained. Higher density panels can be produced on a cost competitive basis with the standard salami panels