13 research outputs found

    Series Bosch System Development

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    State-of-the-art (SOA) carbon dioxide (CO2) reduction technology for the International Space Station produces methane as a byproduct. This methane is subsequently vented overboard. The associated loss of hydrogen ultimately reduces the mass of oxygen that can be recovered from CO2 in a closed-loop life support system. As an alternative to SOA CO2 reduction technology, NASA is exploring a Series-Bosch system capable of reducing CO2 with hydrogen to form water and solid carbon. This results in 100% theoretical recovery of oxygen from metabolic CO2. In the past, Bosch-based technology did not trade favorably against SOA technology due to a high power demand, low reaction efficiencies, concerns with carbon containment, and large resupply requirements necessary to replace expended catalyst cartridges. An alternative approach to Bosch technology, labeled "Series-Bosch," employs a new system design with optimized multi-stage reactors and a membrane-based separation and recycle capability. Multi-physics modeling of the first stage reactor, along with chemical process modeling of the integrated system, has resulted in a design with potential to trade significantly better than previous Bosch technology. The modeling process and resulting system architecture selection are discussed

    Size, Role and Performance in the Oil and Gas Sector

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    The oil and gas sector is a key driver of the Canadian and Albertan economies. Directly and indirectly it typically accounts for roughly half of Alberta’s GDP, as well as one-third of the country’s business investment and a quarter of business profits — and rising global demand will only add to these figures. However, that energy sector is also a changeable place populated by companies of all shapes and sizes, from small Emerging Juniors to wellestablished Majors whose daily production capacities are hundreds or thousands of times greater. The sector’s assorted firms have different structures and ambitions, respond in distinct ways to market forces and have unique impacts on the economy. These differences in size, role and performance must be reflected in energy and related economic policies if they are to be effective in achieving policy goals. For example, they must recognize that the smallest firms are not always the fastest growers or the most innovative; that Intermediates are the most highly leveraged, with the highest debt-to-equity ratios; and that while Majors tend to have the lowest average cost per well drilled, they also (along with Emerging Juniors) have the highest operating costs. Despite the industry’s critical importance, relatively little hard data has been made available concerning companies’ structure, behaviour and performance, based on size. This paper goes a considerable way toward filling that gap, bringing together comprehensive datasets on 340 public oil and gas firms to chart essential patterns and trends, so policymakers and industry watchers can better understand the complexity and functioning of this important sector

    Ongoing Development of a Series Bosch Reactor System

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    Future manned missions to deep space or planetary surfaces will undoubtedly require highly robust, efficient, and regenerable life support systems that require minimal consumables. To meet this requirement, NASA continues to explore a Boschbased carbon dioxide reduction system to recover oxygen from CO2. In order to improve the equivalent system mass of Bosch systems, we seek to design and test a "Series Bosch" system in which two reactors in series are optimized for the two steps of the reaction, as well as to explore the use of in situ materials as carbon deposition catalysts. Here we report recent developments in this effort including assembly and initial testing of a Reverse WaterGas Shift reactor (RWGSr) and initial testing of two gas separation membranes. The RWGSr was sized to reduce CO2 produced by a crew of four to carbon monoxide as the first stage in a Series Bosch system. The gas separation membranes, necessary to recycle unreacted hydrogen and CO2, were similarly sized. Additionally, we report results of preliminary experiments designed to determine the catalytic properties of Martian and Lunar regolith simulant for the carbon deposition step

    Mars Atmospheric In Situ Resource Utilization Projects at the Kennedy Space Center

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    The atmosphere of Mars, which is 96 percent carbon dioxide (CO2), is a rich resource for the human exploration of the red planet, primarily by the production of rocket propellants and oxygen for life support. Three recent projects led by NASAs Kennedy Space Center have been investigating the processing of CO2. The first project successfully demonstrated the Mars Atmospheric Processing Module (APM), which freezes CO2 with cryocoolers and combines sublimated CO2 with hydrogen to make methane and water. The second project absorbs CO2 with Ionic Liquids and electrolyzes it with water to make methane and oxygen, but with limited success so far. A third project plans to recover up to 100 of the oxygen in spacecraft respiratory CO2. A combination of the Reverse Water Gas Shift reaction and the Boudouard reaction eventually fill the reactor up with carbon, stopping the process. A system to continuously remove and collect carbon has been tested with encouraging results

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

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    BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)

    Size, Role and Performance in the Oil and Gas Sector

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    The oil and gas sector is a key driver of the Canadian and Albertan economies. Directly and indirectly it typically accounts for roughly half of Alberta’s GDP, as well as one-third of the country’s business investment and a quarter of business profits — and rising global demand will only add to these figures. However, that energy sector is also a changeable place populated by companies of all shapes and sizes, from small Emerging Juniors to wellestablished Majors whose daily production capacities are hundreds or thousands of times greater. The sector’s assorted firms have different structures and ambitions, respond in distinct ways to market forces and have unique impacts on the economy. These differences in size, role and performance must be reflected in energy and related economic policies if they are to be effective in achieving policy goals. For example, they must recognize that the smallest firms are not always the fastest growers or the most innovative; that Intermediates are the most highly leveraged, with the highest debt-to-equity ratios; and that while Majors tend to have the lowest average cost per well drilled, they also (along with Emerging Juniors) have the highest operating costs. Despite the industry’s critical importance, relatively little hard data has been made available concerning companies’ structure, behaviour and performance, based on size. This paper goes a considerable way toward filling that gap, bringing together comprehensive datasets on 340 public oil and gas firms to chart essential patterns and trends, so policymakers and industry watchers can better understand the complexity and functioning of this important sector

    Disruptive sharing in a digital age: rejecting neoliberalism?

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    Some argue that neoliberalism can be seen as having negated its negation, namely socialism and communism, and become unquestionable and common sense. However, many practices from below resist, reject or at least disrupt the stringent property rights regime and the primacy of the market, two core elements of neoliberal ideology. Some of these practices of resistance are in the form of a disruption to or rejection of the commodity exchange model. In this article we address three modes of sharing in a digital context, embedded in a cultural exchange model - sharing code, sharing content and sharing access. These different practices of giving and sharing are analysed according to the way in which reciprocity is articulated, the extent to which they disrupt the capitalist model of commodity exchange, and the ways in which they interact or not with it. We conclude that all forms of digital sharing involve degrees of reciprocity, and that all sharing in digital contexts is gradually appropriated by capitalist logics, mainly through the creation of auxiliary revenues. Many sharing practices do not intend to reject or disrupt, so, while some sharing practices might constitute a (partial) disruption to the commodity exchange model, they may not necessarily result in its negation. Recent attempts by states and parts of the entertainment industry to discipline or coerce the revivified participatory culture and its cultural exchange ethic to fit the commodity exchange model raise serious concerns
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