Hydrogen-oxygen proton-exchange membrane fuel cells and electrolyzers

Hydrogen-oxygen solid polymer electrolyte (SPE) fuel cells and SPE electrolyzers (products of Hamilton Standard) both use a Proton-Exchange Membrane (PEM) as the sole electrolyte. These solid electrolyte devices have been under continuous development for over 30 years. This experience has resulted in a demonstrated ten-year SPE cell life capability under load conditions. Ultimate life of PEM fuel cells and electrolyzers is primarily related to the chemical stability of the membrane. For perfluorocarbon proton exchange membranes an accurate measure of the membrane stability is the fluoride loss rate. Millions of cell hours have contributed to establishing a relationship between fluoride loss rates and average expected ultimate cell life. This relationship is shown. Several features have been introduced into SPE fuel cells and SPE electrolyzers such that applications requiring greater than or equal to 100,000 hours of life can be considered. Equally important as the ultimate life is the voltage stability of hydrogen-oxygen fuel cells and electrolyzers. Here again the features of SPE fuel cells and SPE electrolyzers have shown a cell voltage stability in the order of 1 microvolt per hour. That level of stability has been demonstrated for tens of thousands of hours in SPE fuel cells at up to 500 amps per square foot (ASF) current density

Hydrogen-oxygen proton-exchange membrane fuel cells and electrolyzers

Hydrogen-oxygen SPE fuel cells and SPE electrolyzers (products of Hamilton Standard) both use a Proton-Exchange Membrane (PEM) as the sole electrolyte. The SPE cells have demonstrated a ten year life capability under load conditions. Ultimate life of PEM fuel cells and electrolyzers is primarily related to the chemical stability of the membrane. For perfluorocarbon proton-exchange membranes an accurate measure of the membrane stability is the fluoride loss rate. Millions of cell hours have contributed to establishing a relationship between fluroride loss rates and average expected ultimate cell life. Several features were introduced into SPE fuel cells and SPE electrolyzers such that applications requiring greater than or equal to 100,000 hours of life can be considered. Equally important as the ultimate life is the voltage stability of hydrogen-oxygen fuel cells and electrolyzers. Here again the features of SPE fuel cells and SPE electrolyzers have shown a cell voltage stability in the order of 1 microvolt per hour. That level of stability were demonstrated for tens of thousands of hours in SPE fuel cells at up to 500 amps per square foot (ASF) current density. The SPE electrolyzers have demonstrated the same at 1000 ASF. Many future extraterrestrial applications for fuel cells require that they be self recharged. To translate the proven SPE cell life and stability into a highly reliable extraterrestrial electrical energy storage system, a simplification of supporting equipment is required. Static phase separation, static fluid transport and static thermal control will be most useful in producting required system reliability. Although some 200,000 SPE fuel cell hours were recorded in earth orbit with static fluid phase separation, no SPE electrolyzer has, as yet, operated in space

Optical diagnostics for density measurement in high-quality laser-plasma electron accelerators

Implementation of laser-plasma-based acceleration stages in user-oriented facilities requires the definition and deployment of appropriate diagnostic methodologies to monitor and control the acceleration process. An overview is given here of optical diagnostics for density measurement in laser-plasma acceleration stages, with emphasis on well-established and easily implemented approaches. Diagnostics for both neutral gas and free-electron number density are considered, highlighting real-time measurement capabilities. Optical interferometry, in its various configurations, from standard two-arm to more advanced common-path designs, is discussed, along with spectroscopic techniques such as Stark broadening and Raman scattering. A critical analysis of the diagnostics presented is given concerning their implementation in laser-plasma acceleration stages for the production of high-quality GeV electron bunches

Intra-cycle depolarization of ultraintense laser pulses focused by off-axis parabolic mirrors

A study of the structure of the electric and magnetic fields of ultraintense laser pulses focused by an off-axis parabolic mirror is reported. At first, a theoretical model is laid out, whose final equations integration allows the space and time structure of the fields to be retrieved. The model is then employed to investigate the field patterns at different times within the optical cycle, for off-axis parabola parameters normally employed in the context of ultraintense laser–plasma interaction experiments. The results show that nontrivial, complex electromagnetic field patterns are observed at the time at which the electric and magnetic fields are supposed to vanish. The importance of this effect is then studied for different laser polarizations, $f$ numbers and off-axis angles

Complex reconstruction after extreme Fournier’s gangrene; a case report

In this article we present a severe case of Fournier\u27s gangrene (FG) that affected a 64-year-old male patient, with no other known comorbidities. FG is a type of necrotizing fasciitis of the perineal and genital regions, that affects mostly males in the 5th-7th decades, with mortality rates that reach 70%. The infection usually advances through the superficial fascial layers of the perineum and abdomen and affects the skin. In our case the infection also affected the spermatic fasciae and advanced in the abdominal and pelvic cavities, abdominal muscles, and surrounding soft tissues. Subsequent debridement left the patient with large soft tissue and muscle defects and an open abdominal cavity that needed reconstruction. We designed two pedicled tensor fascia lata flaps with extra fascia for abdominal support. Healing was marked by a pseudomonas aeruginosa infection that led to skin graft sloughing and marginal wound breakdown, which was treated with antibiotics and local wound care. Eventually the wounds healed, and the patient left the hospital 11 weeks after admittance. The outcome of the case was good considering the initial extent of the infection. The cosmetic shortcomings were not shared by the patient and future scar corrections are planned

A Systematic Review of Bacterial Foodborne Outbreaks Related to Red Meat and Meat Products

Our investigation focused on foodborne outbreaks related to meat and meat products, published in peer reviewed journals in the period 1980–2015. Most of the outbreaks, investigated in this study, were caused by Escherichia coli and Salmonella, causing 33 and 21 outbreaks, respectively, mostly in Europe and the United States. In the E. coli outbreaks, the total number of reported cases was 1966, of which 1543 were laboratory confirmed. The number of cases requiring hospitalization was 476, of whom 233 cases had a hemolytic-uremic syndrome (HUS), and the reported deaths were 32. All of the E. coli outbreaks, except four, were caused by serovar O157:H7. The other four outbreaks were caused by the following serovars: O111:H8, O26:H11, O111, and O103:H25. Fresh processed meat products were the category most frequently implicated. In the Salmonella outbreaks, the total number of all reported cases was 2279, of whom 1891 were laboratory confirmed. The number of reported cases requiring hospitalization was 94, and seven were reported dead. Regarding Salmonella, eight serovars caused those outbreaks. The most common serovar causing Salmonella-related outbreaks was Salmonella Typhimurium. The food category most frequently implicated in those outbreaks was raw-cured fermented sausages. Other organisms linked to meat-associated outbreaks, but less frequently reported, were Staphylococcus aureus, Bacillus cereus, Clostridium perfringens, Clostridium botulinum, and Listeria monocytogenes. Issues of the burden of outbreaks, the challenges of comparing global outbreaks, food attribution, and how the meat industry works to meet consumer demands while maintaining food safety are discussed

Overview and specifications of laser and target areas at the Intense Laser Irradiation Laboratory

Abstract We present the main features of the ultrashort, high-intensity laser installation at the Intense Laser Irradiation Laboratory (ILIL) including laser, beam transport and target area specifications. The laboratory was designed to host laser–target interaction experiments of more than 220 TW peak power, in flexible focusing configurations, with ultrarelativistic intensity on the target. Specifications have been established via dedicated optical diagnostic assemblies and commissioning interaction experiments. In this paper we give a summary of laser specifications available to users, including spatial, spectral and temporal contrast features. The layout of the experimental target areas is presented, with attention to the available configurations of laser focusing geometries and diagnostics. Finally, we discuss radiation protection measures and mechanical stability of the laser focal spot on the target

Location matters:Valuing firm-specific nonmarket risk in the global mining industry

Research summary Using collective action and social movement theory, we investigate the potential incentives and ability of stakeholders to engage in collective action that can increase firm-specific nonmarket risk of mining companies. We argue that proximity to the nearest environmentally sensitive water source increases the probability that local stakeholders will take collective actions that impose material costs on the focal mine. We hypothesize that stock markets recognize this nonmarket risk and apply a discount on announcements related to mines located near such areas, and that these risks are moderated by the type of mineral, the nature of the water source, and the strength of host country institutions. Using a unique data set and an event study method, we find support for most of our arguments. Managerial summary We argue that mines located near environmentally sensitive water sources are subject to nonmarket risks arising from the potential collective actions of local stakeholders and their allies. Stakeholder mobilization can impose material costs on a mine in the form of delays, regulatory hurdles, and closure. We find that stock markets recognize these nonmarket risks and apply a discount on announcements by mining companies whose mines are located near environmentally sensitive water sources, particularly rivers. However, we also find that investor reaction is stronger in countries with strong institutions that support collective action. Thus, nonmarket risk management is important even in countries that are typically characterized by low political and institutional risks. We discuss the degree to which these results can be generalized beyond mining

Needs and Design Assessment for Corn Production Enterprise in Selected Agrarian Reform Communities of Cagayan de Oro City and Lanao del Norte, Southern Philippines

The needs and design assessment was conducted in the Agrarian Reform Communities of Cagayan de Oro City and Lanao del Norte. It aimed to identify performance requirements, knowledge, skills, and abilities of the Agrarian Reform Beneficiaries Organizations (ARBO), as well as the technology and facility needs for a corn production enterprise. Among the ARBOs assessed were: Pagalungan and Tagpangi Tribal and Settlers Association of Women Agrarian Reform Beneficiaries Cooperative, Taglimao Farmers Multi-purpose Cooperative, Indahag Agrarian Reform Community Multipurpose Cooperative, Taguanao Agrarian Reform Community Multipurpose Cooperative and Palambu Cooperative. The needs assessment revealed that the ARBOs still need technologies, as well as facilities and machineries for corn production and marketing. The ARCs offer biophysical condition suitable for corn production. They have natural assets that would favor corn production as the main economic activity. Corn is an appropriate commodity for the ARCCESS project in the ARCs mentioned. The farmers in the ARCs have extensive experience and training related to corn production. The ARBOs have other needs, such as capability development, common service facility on pre- and post-harvest facilities, project monitoring and enterprise development, and financial management and assistance. With the provision of the aforementioned recommended activities and facilities, this should result in increased production, improved quality of products, increased income and realized more profits; thereby improving their standard of living. This will eventually lead to economic growth and development of the community and to the economy as a whole