pH-controlled gas-generating mineralized nanoparticles: a theranostic agent for ultrasound imaging and therapy of cancers.

PubMed

Min, Kyung Hyun; Min, Hyun Su; Lee, Hong Jae; Park, Dong Jin; Yhee, Ji Young; Kim, Kwangmeyung; Kwon, Ick Chan; Jeong, Seo Young; Silvestre, Oscar F; Chen, Xiaoyuan; Hwang, Yu-Shik; Kim, Eun-Cheol; Lee, Sang Cheon

2015-01-27

We report a theranostic nanoparticle that can express ultrasound (US) imaging and simultaneous therapeutic functions for cancer treatment. We developed doxorubicin-loaded calcium carbonate (CaCO3) hybrid nanoparticles (DOX-CaCO3-MNPs) through a block copolymer templated in situ mineralization approach. The nanoparticles exhibited strong echogenic signals at tumoral acid pH by producing carbon dioxide (CO2) bubbles and showed excellent echo persistence. In vivo results demonstrated that the DOX-CaCO3-MNPs generated CO2 bubbles at tumor tissues sufficient for echogenic reflectivity under a US field. In contrast, the DOX-CaCO3-MNPs located in the liver or tumor-free subcutaneous area did not generate the CO2 bubbles necessary for US contrast. The DOX-CaCO3-MNPs could also trigger the DOX release simultaneously with CO2 bubble generation at the acidic tumoral environment. The DOX-CaCO3-MNPs displayed effective antitumor therapeutic activity in tumor-bearing mice. The concept described in this work may serve as a useful guide for development of various theranostic nanoparticles for US imaging and therapy of various cancers.

CO2 Reduction Effect of the Utilization of Waste Heat and Solar Heat in City Gas System

NASA Astrophysics Data System (ADS)

Okamura, Tomohito; Matsuhashi, Ryuji; Yoshida, Yoshikuni; Hasegawa, Hideo; Ishitani, Hisashi

We evaluate total energy consumption and CO2 emissions in the phase of the city gas utilization system from obtaining raw materials to consuming the product. First, we develop a simulation model which calculates CO2 emissions for monthly and hourly demands of electricity, heats for air conditioning and hot-water in a typical hospital. Under the given standard capacity and operating time of CGS, energy consumption in the equipments is calculated in detail considering the partial load efficiency and the control by the temperature of exhaust heat. Then, we explored the optimal size and operation of city gas system that minimizes the life cycle CO2 emissions or total cost. The cost-effectiveness is compared between conventional co-generation, solar heat system, and hybrid co-generation utilizing solar heat. We formulate a problem of mixed integer programming that includes integral parameters that express the state of system devices such as on/off of switches. As a result of optimization, the hybrid co-generation can reduce annual CO2 emissions by forty-three percent compared with the system without co-generation. Sensitivity for the scale of CGS on CO2 reduction and cost is also analyzed.

On the impact of CO{sub 2} emission-trading on power generation emissions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chappin, E.J.L.; Dijkema, G.P.J.

2009-03-15

In Europe one of the main policy instruments to meet the Kyoto reduction targets is CO{sub 2} emission-trading (CET), which was implemented as of January 2005. In this system, companies active in specific sectors must be in the possession of CO{sub 2} emission rights to an amount equal to their CO{sub 2} emission. In Europe, electricity generation accounts for one-third of CO{sub 2} emissions. Since the power generation sector has been liberalized, reregulated and privatized in the last decade, around Europe autonomous companies determine the sectors' CO{sub 2} emission. Short-term they adjust their operation, long-term they decide on (dis) investmentmore » in power generation facilities and technology selection. An agent-based model is presented to elucidate the effect of CET on the decisions of power companies in an oligopolistic market. Simulations over an extensive scenario-space show that there CET does have an impact. A long-term portfolio shift towards less-CO{sub 2} intensive power generation is observed. However, the effect of CET is relatively small and materializes late. The absolute emissions from power generation rise under most scenarios. This corresponds to the dominant character of current capacity expansion planned in the Netherlands (50%) and in Germany (68%), where companies have announced many new coal based power plants. Coal is the most CO{sub 2} intensive option available and it seems surprising that even after the introduction of CET these capacity expansion plans indicate a preference for coal. Apparently in power generation the economic effect of CO{sub 2} emission-trading is not sufficient to outweigh the economic incentives to choose for coal.« less

Iterative Authoring Using Story Generation Feedback: Debugging or Co-creation?

NASA Astrophysics Data System (ADS)

Swartjes, Ivo; Theune, Mariët

We explore the role that story generation feedback may play within the creative process of interactive story authoring. While such feedback is often used as 'debugging' information, we explore here a 'co-creation' view, in which the outcome of the story generator influences authorial intent. We illustrate an iterative authoring approach in which each iteration consists of idea generation, implementation and simulation. We find that the tension between authorial intent and the partially uncontrollable story generation outcome may be relieved by taking such a co-creation approach.

Co-Rumination Exacerbates Stress Generation among Adolescents with Depressive Symptoms.

PubMed

Rose, Amanda J; Glick, Gary C; Smith, Rhiannon L; Schwartz-Mette, Rebecca A; Borowski, Sarah K

2017-07-01

Through stress generation, individuals' own thoughts and behaviors can actually lead to increases in their experience of stress. Unfortunately, stress generation is especially common among individuals who are already suffering from elevated depressive symptoms. However, despite the acknowledgement that some individuals with depressive symptoms generate greater stress than others, few studies have identified specific factors that could exacerbate stress generation among individuals with depressive symptoms. The present study examines co-rumination as a factor that might exacerbate stress generation among adolescents with depressive symptoms using a short-term longitudinal design. Considering these processes among adolescents was critical given that many youth experience increases in depressive symptoms at this developmental stage and that co-rumination also becomes more common at adolescence. Participants were 628 adolescents (326 girls; 302 boys) who reported on their depressive symptoms, experiences of stress, and co-rumination with a best friend. Interpersonal stressors (peer and family stress) and non-interpersonal stressors (school and sports stress) were assessed. Consistent with past research, adolescents with depressive symptoms experienced greater interpersonal and non-interpersonal stress over time. Importantly, co-rumination interacted with both depressive symptoms and gender in predicting increases in peer stress. Depressive symptoms predicted the generation of peer stress only for girls who reported high levels of co-rumination with friends. Implications for protecting youth with depressive symptoms against stress generation are discussed.

Assessing CO2 Mitigation Options Utilizing Detailed Electricity Characteristics and Including Renewable Generation

NASA Astrophysics Data System (ADS)

Bensaida, K.; Alie, Colin; Elkamel, A.; Almansoori, A.

2017-08-01

This paper presents a novel techno-economic optimization model for assessing the effectiveness of CO2 mitigation options for the electricity generation sub-sector that includes renewable energy generation. The optimization problem was formulated as a MINLP model using the GAMS modeling system. The model seeks the minimization of the power generation costs under CO2 emission constraints by dispatching power from low CO2 emission-intensity units. The model considers the detailed operation of the electricity system to effectively assess the performance of GHG mitigation strategies and integrates load balancing, carbon capture and carbon taxes as methods for reducing CO2 emissions. Two case studies are discussed to analyze the benefits and challenges of the CO2 reduction methods in the electricity system. The proposed mitigations options would not only benefit the environment, but they will as well improve the marginal cost of producing energy which represents an advantage for stakeholders.

Predictive model for CO2 generation and decay in building envelopes

NASA Astrophysics Data System (ADS)

Aglan, Heshmat A.

2003-01-01

Understanding carbon dioxide generation and decay patterns in buildings with high occupancy levels is useful to identify their indoor air quality, air change rates, percent fresh air makeup, occupancy pattern, and how a variable air volume system to off-set undesirable CO2 level can be modulated. A mathematical model governing the generation and decay of CO2 in building envelopes with forced ventilation due to high occupancy is developed. The model has been verified experimentally in a newly constructed energy efficient healthy house. It was shown that the model accurately predicts the CO2 concentration at any time during the generation and decay processes.

CO2-Free Power Generation on an Iron Group Nanoalloy Catalyst via Selective Oxidation of Ethylene Glycol to Oxalic Acid in Alkaline Media

PubMed Central

Matsumoto, Takeshi; Sadakiyo, Masaaki; Ooi, Mei Lee; Kitano, Sho; Yamamoto, Tomokazu; Matsumura, Syo; Kato, Kenichi; Takeguchi, Tatsuya; Yamauchi, Miho

2014-01-01

An Fe group ternary nanoalloy (NA) catalyst enabled selective electrocatalysis towards CO2-free power generation from highly deliverable ethylene glycol (EG). A solid-solution-type FeCoNi NA catalyst supported on carbon was prepared by a two-step reduction method. High-resolution electron microscopy techniques identified atomic-level mixing of constituent elements in the nanoalloy. We examined the distribution of oxidised species, including CO2, produced on the FeCoNi nanoalloy catalyst in the EG electrooxidation under alkaline conditions. The FeCoNi nanoalloy catalyst exhibited the highest selectivities toward the formation of C2 products and to oxalic acid, i.e., 99 and 60%, respectively, at 0.4 V vs. the reversible hydrogen electrode (RHE), without CO2 generation. We successfully generated power by a direct EG alkaline fuel cell employing the FeCoNi nanoalloy catalyst and a solid-oxide electrolyte with oxygen reduction ability, i.e., a completely precious-metal-free system. PMID:25004118

Study on O2 generation and CO2 absorption capability of four co-cultured salad plants in an enclosed system

NASA Astrophysics Data System (ADS)

Guo, Shuangsheng; Ai, Weidang; Tang, Yongkang; Cheng, Quanyong; Shen, Yunze; Qin, Lifeng; Ma, Jialu; Zhu, Jingtao; Ren, Jin

2014-06-01

The ability to generate O2 and absorb CO2 of several co-cultured vegetable plants in an enclosed system was studied to provide theoretical reference for the future man-plant integrated tests. Four kinds of salad plants (Lactuca sativa L. var. Dasusheng, Lactuca sativa L. var. Youmaicai, Gynura bicolor and Cichorium endivia L.) were grown in the CELSS Integration Test Platform (CITP). The environmental factors including O2 and CO2 concentration were continuously monitored on-line and the plant biomass was measured at the end of the test. The changing rules of O2 and CO2 concentration in the system were basically understood and it was found that the O2 generated by the plants could satisfy the respiratory needs of 1.75 persons by calculation. It was also found that the plants could absorb the CO2 breathed out by 2 persons when the light intensity was raised to 550 mmol m-2 s-1 PPF. The results showed that the co-cultured plants hold good compatibility and excellent O2-generating and CO2-absorbing capability. They could also supply some fresh edible vegetable for a 2-person crew.

Long Wavelength Electromagnetic Light Bullets Generated by a 10.6 micron CO2 Ultrashort Pulsed Source

DTIC Science & Technology

2016-11-29

AFRL-AFOSR-VA-TR-2016-0365 Long Wavelength Electromagnetic Light Bullets Generated by a 10.6 micron CO2 Ultrashort Pulsed Source Jerome Moloney...SUBTITLE "Long Wavelength Electromagnetic Light Bullets Generated by a 10.6 micron CO2 Ultrashort Pulsed Source 5a. CONTRACT NUMBER FA9550-15-1-0272 5b...afosr.reports.sgizmo.com/s3/> Subject: Final Report to Dr. Arje Nachman Contract/Grant Title: Long Wavelength Electromagnetic Light Bullets Generated by a 10.6

A Study on the Optimal Generation Mix Based on Portfolio Theory with Considering the Basic Condition for Power Supply

NASA Astrophysics Data System (ADS)

Kato, Moritoshi; Zhou, Yicheng

This paper presents a novel method to analyze the optimal generation mix based on portfolio theory with considering the basic condition for power supply, which means that electricity generation corresponds with load curve. The optimization of portfolio is integrated with the calculation of a capacity factor of each generation in order to satisfy the basic condition for power supply. Besides, each generation is considered to be an asset, and risks of the generation asset both in its operation period and construction period are considered. Environmental measures are evaluated through restriction of CO2 emissions, which are indicated by CO2 price. Numerical examples show the optimal generation mix according to risks such as the deviation of capacity factor of nuclear power or restriction of CO2 emissions, the possibility of introduction of clean coal technology (IGCC, CCS) or renewable energy, and so on. The results of this work will be possibly applied as setting the target of the generation mix for the future according to prospects of risks of each generation and restrictions of CO2 emissions.

Life-Cycle Evaluation of Domestic Energy Systems

NASA Astrophysics Data System (ADS)

Bando, Shigeru; Hihara, Eiji

Among the growing number of environmental issues, the global warming due to the increasing emission of greenhouse gases, such as carbon dioxide CO2, is the most serious one. In order to reduce CO2 emissions in energy use, it is necessary to reduce primary energy consumption, and to replace energy sources with alternatives that emit less CO2.One option of such ideas is to replace fossil gas for water heating with electricity generated by nuclear power, hydraulic power, and other methods with low CO2 emission. It is also important to use energy efficiently and to reduce waste heat. Co-generation system is one of the applications to be able to use waste heat from a generator as much as possible. The CO2 heat pump water heaters, the polymer electrolyte fuel cells, and the micro gas turbines have high potential for domestic energy systems. In the present study, the life-cycle cost, the life-cycle consumption of primary energy and the life-cycle emission of CO2 of these domestic energy systems are compare. The result shows that the CO2 heat pump water heaters have an ability to reduce CO2 emission by 10%, and the co-generation systems also have another ability to reduce primary energy consumption by 20%.

Short run effects of a price on carbon dioxide emissions from U.S. electric generators.

PubMed

Newcomer, Adam; Blumsack, Seth A; Apt, Jay; Lave, Lester B; Morgan, M Granger

2008-05-01

The price of delivered electricity will rise if generators have to pay for carbon dioxide emissions through an implicit or explicit mechanism. There are two main effects that a substantial price on CO2 emissions would have in the short run (before the generation fleet changes significantly). First, consumers would react to increased price by buying less, described by their price elasticity of demand. Second, a price on CO2 emissions would change the order in which existing generators are economically dispatched, depending on their carbon dioxide emissions and marginal fuel prices. Both the price increase and dispatch changes depend on the mix of generation technologies and fuels in the region available for dispatch, although the consumer response to higher prices is the dominant effect. We estimate that the instantaneous imposition of a price of $35 per metric ton on CO2 emissions would lead to a 10% reduction in CO2 emissions in PJM and MISO at a price elasticity of -0.1. Reductions in ERCOT would be about one-third as large. Thus, a price on CO2 emissions that has been shown in earlier workto stimulate investment in new generation technology also provides significant CO2 reductions before new technology is deployed at large scale.

Committed CO2 Emissions of China's Coal-fired Power Plants

NASA Astrophysics Data System (ADS)

Suqin, J.

2016-12-01

The extent of global warming is determined by the cumulative effects of CO2 in the atmosphere. Coal-fired power plants, the largest anthropogenic source of CO2 emissions, produce large amount of CO2 emissions during their lifetimes of operation (committed emissions), which thus influence the future carbon emission space under specific targets on mitigating climate change (e.g., the 2 degree warming limit relative to pre-industrial levels). Comprehensive understanding of committed CO2 emissions for coal-fired power generators is urgently needed in mitigating global climate change, especially in China, the largest global CO2emitter. We calculated China's committed CO2 emissions from coal-fired power generators installed during 1993-2013 and evaluated their impact on future emission spaces at the provincial level, by using local specific data on the newly installed capacities. The committed CO2 emissions are calculated as the product of the annual coal consumption from newly installed capacities, emission factors (CO2emissions per unit crude coal consumption) and expected lifetimes. The sensitivities about generators lifetimes and the drivers on provincial committed emissions are also analyzed. Our results show that these relatively recently installed coal-fired power generators will lead to 106 Gt of CO2 emissions over the course of their lifetimes, which is more than three times the global CO2 emissions from fossil fuels in 2010. More than 80% (85 Gt) of their total committed CO2 will be emitted after 2013, which are referred to as the remaining emissions. Due to the uncertainties of generators lifetime, these remaining emissions would increase by 45 Gt if the lifetimes of China's coal-fired power generators were prolonged by 15 years. Furthermore, the remaining emissions are very different among various provinces owing to local developments and policy disparities. Provinces with large amounts of secondary industry and abundant coal reserves have higher committed emissions. The national and provincial CO2 emission mitigation objectives might be greatly restricted by existing and planned power plants in China. The policy implications of our results have also been discussed.

Polyacrylonitrile Fibers Anchored Cobalt/Graphene Sheet Nanocomposite: A Low-Cost, High-Performance and Reusable Catalyst for Hydrogen Generation.

PubMed

Zhang, Fei; Huang, Guoji; Hou, Chengyi; Wang, Hongzhi; Zhang, Qinghong; Li, Yaogang

2016-06-01

Cobalt and its composites are known to be active and inexpensive catalysts in sodium borohydride (NaBH4) hydrolysis to generate clean and renewable hydrogen energy. A novel fiber catalyst, cobalt/graphene sheet nanocomposite anchored on polyacrylonitrile fibers (Co/GRs-PANFs), which can be easily recycled and used in any reactor with different shapes, were synthesized by anchoring cobalt/graphene (Co/GRs) on polyacrylonitrile fibers coated with graphene (GRs-PANFs) at low temperature. The unique structure design effectively prevents the inter-sheet restacking of Co/GRs and fully exploits the large surface area of novel hybrid material for generate hydrogen. And the extra electron transfer path supplied by GRs on the surface of GRs-PANFs can also enhance their catalysis performances. The catalytic activity of the catalyst was investigated by the hydrolysis of NaBH4 in aqueous solution with GRs-PANFs. GRs powders and Co powders were used as control groups. It was found that both GRs and fiber contributed to the hydrogen generation rate of Co/GRs-PANFs (3222 mL x min(-1) x g(-1)), which is much higher than that of cobalt powders (915 mL x min(-1) x g(-1)) and Co/GRs (995 mL x min(-1) x g(-1)). The improved hydrogen generation rate, low cost and uncomplicated recycling make the Co/GRs-PANFs promising candidate as catalysts for hydrogen generation.

Analysis of electric power industry restructuring

NASA Astrophysics Data System (ADS)

Al-Agtash, Salem Yahya

1998-10-01

This thesis evaluates alternative structures of the electric power industry in a competitive environment. One structure is based on the principle of creating a mandatory power pool to foster competition and manage system economics. The structure is PoolCo (pool coordination). A second structure is based on the principle of allowing independent multilateral trading and decentralized market coordination. The structure is DecCo (decentralized coordination). The criteria I use to evaluate these two structures are: economic efficiency, system reliability and freedom of choice. Economic efficiency evaluation considers strategic behavior of individual generators as well as behavioral variations of different classes of consumers. A supply-function equilibria model is characterized for deriving bidding strategies of competing generators under PoolCo. It is shown that asymmetric equilibria can exist within the capacities of generators. An augmented Lagrangian approach is introduced to solve iteratively for global optimal operations schedules. Under DecCo, the process involves solving iteratively for system operations schedules. The schedules reflect generators strategic behavior and brokers' interactions for arranging profitable trades, allocating losses and managing network congestion. In the determination of PoolCo and DecCo operations schedules, overall costs of power generation (start-up and shut-down costs and availability of hydro electric power) as well as losses and costs of transmission network are considered. For system reliability evaluation, I examine the effect of PoolCo and DecCo operating conditions on the system security. Random component failure perturbations are generated to simulate the actual system behavior. This is done using Monte Carlo simulation. Freedom of choice evaluation accounts for schemes' beneficial opportunities and capabilities to respond to consumers expressed preferences. An IEEE 24-bus test system is used to illustrate the concepts developed for economic efficiency evaluation. The system was tested over two years time period. The results indicate 2.6684 and 2.7269 percent of efficiency loss on average for PoolCo and DecCo, respectively. These values, however, do not represent forecasts of efficiency losses of PoolCo- and DecCo-based competitive industries. Rather, they are illustrations of the efficiency losses for the given IEEE test system and based on the modeling assumptions underlying framework development.

An outbreak of carbon monoxide poisoning after a major ice storm in Maine.

PubMed

Daley, W R; Smith, A; Paz-Argandona, E; Malilay, J; McGeehin, M

2000-01-01

Unintentional carbon monoxide (CO) exposure kills over 500 people in the U.S. annually. Outbreaks of CO poisoning have occurred after winter storms. The objective of this study was to describe clinical features and identify important risk factors of a CO poisoning outbreak occurring after a major ice storm. The study design included a case series of CO poisoning patients, a telephone survey of the general community, and a case-controlled study of households using specific CO sources. The setting was the primary service area of four hospital emergency departments located in the heavily storm-impacted interior region of Maine. Participants included all patients with a laboratory-confirmed diagnosis of CO poisoning during the 2 weeks after the storm onset, and a population-based comparison group of 522 households selected by random digit dialing. There were 100 cases identified, involving 42 common-source exposure incidents, most of them during the first week. Though classic CO symptoms of headache, dizziness, and nausea predominated, 9 patients presented with chest pain and 10 were asymptomatic. One patient died and 5 were transferred for hyperbaric oxygen therapy. Gasoline-powered electric generators were a CO source in 30 incidents, kerosene heaters in 8, and propane heaters in 4. In the community, 31.4% of households used a generator after the ice storm. The strongest risk factor for poisoning was locating a generator in a basement or an attached structure such as a garage. Cases of CO poisoning with various presentations can be expected in the early aftermath of a severe ice storm. Generators are a major CO source and generator location an important risk factor for such disasters.

External CO2 and water supplies for enhancing electrical power generation of air-cathode microbial fuel cells.

PubMed

Ishizaki, So; Fujiki, Itto; Sano, Daisuke; Okabe, Satoshi

2014-10-07

Alkalization on the cathode electrode limits the electrical power generation of air-cathode microbial fuel cells (MFCs), and thus external proton supply to the cathode electrode is essential to enhance the electrical power generation. In this study, the effects of external CO2 and water supplies to the cathode electrode on the electrical power generation were investigated, and then the relative contributions of CO2 and water supplies to the total proton consumption were experimentally evaluated. The CO2 supply decreased the cathode pH and consequently increased the power generation. Carbonate dissolution was the main proton source under ambient air conditions, which provides about 67% of total protons consumed for the cathode reaction. It is also critical to adequately control the water content on the cathode electrode of air-cathode MFCs because the carbonate dissolution was highly dependent on water content. On the basis of these experimental results, the power density was increased by 400% (143.0 ± 3.5 mW/m(2) to 575.0 ± 36.0 mW/m(2)) by supplying a humid gas containing 50% CO2 to the cathode chamber. This study demonstrates that the simultaneous CO2 and water supplies to the cathode electrode were effective to increase the electrical power generation of air-cathode MFCs for the first time.

Far-infrared-light shadowgraphy for high extraction efficiency of extreme ultraviolet light from a CO2-laser-generated tin plasma

NASA Astrophysics Data System (ADS)

Matsukuma, Hiraku; Hosoda, Tatsuya; Suzuki, Yosuke; Yogo, Akifumi; Yanagida, Tatsuya; Kodama, Takeshi; Nishimura, Hiroaki

2016-08-01

The two-color, double-pulse method is an efficient scheme to generate extreme ultraviolet light for fabricating the next generation semiconductor microchips. In this method, a Nd:YAG laser pulse is used to expand a several-tens-of-micrometers-scale tin droplet, and a CO2 laser pulse is subsequently directed at the expanded tin vapor after an appropriate delay time. We propose the use of shadowgraphy with a CO2 laser probe-pulse scheme to optimize the CO2 main-drive laser. The distribution of absorption coefficients is derived from the experiment, and the results are converted to a practical absorption rate for the CO2 main-drive laser.

Carbon dioxide emissions from the electricity sector in major countries: a decomposition analysis.

PubMed

Li, Xiangzheng; Liao, Hua; Du, Yun-Fei; Wang, Ce; Wang, Jin-Wei; Liu, Yanan

2018-03-01

The electric power sector is one of the primary sources of CO 2 emissions. Analyzing the influential factors that result in CO 2 emissions from the power sector would provide valuable information to reduce the world's CO 2 emissions. Herein, we applied the Divisia decomposition method to analyze the influential factors for CO 2 emissions from the power sector from 11 countries, which account for 67% of the world's emissions from 1990 to 2013. We decompose the influential factors for CO 2 emissions into seven areas: the emission coefficient, energy intensity, the share of electricity generation, the share of thermal power generation, electricity intensity, economic activity, and population. The decomposition analysis results show that economic activity, population, and the emission coefficient have positive roles in increasing CO 2 emissions, and their contribution rates are 119, 23.9, and 0.5%, respectively. Energy intensity, electricity intensity, the share of electricity generation, and the share of thermal power generation curb CO 2 emissions and their contribution rates are 17.2, 15.7, 7.7, and 2.8%, respectively. Through decomposition analysis for each country, economic activity and population are the major factors responsible for increasing CO 2 emissions from the power sector. However, the other factors from developed countries can offset the growth in CO 2 emissions due to economic activities.

Energetic valorization of wood waste: estimation of the reduction in CO2 emissions.

PubMed

Vanneste, J; Van Gerven, T; Vander Putten, E; Van der Bruggen, B; Helsen, L

2011-09-01

This paper investigates the potential CO(2) emission reductions related to a partial switch from fossil fuel-based heat and electricity generation to renewable wood waste-based systems in Flanders. The results show that valorization in large-scale CHP (combined heat and power) systems and co-firing in coal plants have the largest CO(2) reduction per TJ wood waste. However, at current co-firing rates of 10%, the CO(2) reduction per GWh of electricity that can be achieved by co-firing in coal plants is five times lower than the CO(2) reduction per GWh of large-scale CHP. Moreover, analysis of the effect of government support for co-firing of wood waste in coal-fired power plants on the marginal costs of electricity generation plants reveals that the effect of the European Emission Trading Scheme (EU ETS) is effectively counterbalanced. This is due to the fact that biomass integrated gasification combined cycles (BIGCC) are not yet commercially available. An increase of the fraction of coal-based electricity in the total electricity generation from 8 to 10% at the expense of the fraction of gas-based electricity due to the government support for co-firing wood waste, would compensate entirely for the CO(2) reduction by substitution of coal by wood waste. This clearly illustrates the possibility of a 'rebound' effect on the CO(2) reduction due to government support for co-combustion of wood waste in an electricity generation system with large installed capacity of coal- and gas-based power plants, such as the Belgian one. Copyright © 2011 Elsevier B.V. All rights reserved.

Attraction of subterranean termites (Isoptera) to carbon dioxide.

PubMed

Bernklau, Elisa Jo; Fromm, Erich A; Judd, Timothy M; Bjostad, Louis B

2005-04-01

Subterranean termites, Reticulitermes spp., were attracted to carbon dioxide (CO2) in laboratory and field tests. In behavioral bioassays, Reticulitermes flavipes (Kollar), Reticulitermes tibialis Banks, and Reticulitermes virginicus Banks were attracted to CO2 concentrations between 5 and 50 mmol/mol. In further bioassays, R. tibialis and R. virginicus were attracted to the headspace from polyisocyanurate construction foam that contained 10-12 mmol/mol CO2. In soil bioassays in the laboratory, more termites foraged in chambers containing CO2-generating formulations than in unbaited control chambers. In field tests, stations containing CO2-generating baits attracted R. tibialis away from wooden fence posts at rangeland sites in Colorado. For all of the CO2 formulations tested, termites foraged in significantly more bait stations at treatment fenceposts than in bait stations at the control fenceposts. By the end of the 8-wk study, the number of bait stations located by termites at treatment fenceposts ranged from 40 to 90%. At control fenceposts, termites foraged in only a single station and the one positive station was not located by termites until week 5 of the study. At treatment fenceposts, termites foraged equally in active stations (containing a CO2-generating bait) and passive stations (with no CO2-generating bait), indicating that bait stations may benefit passively from a proximal CO2 source in the soil. CO2 used as an attractant in current baiting systems could improve their effectiveness by allowing earlier exposure of termites to an insecticide.

Mitochondrial Reactive Oxygen Species Trigger Hypoxia-Induced Transcription

NASA Astrophysics Data System (ADS)

Chandel, N. S.; Maltepe, E.; Goldwasser, E.; Mathieu, C. E.; Simon, M. C.; Schumacker, P. T.

1998-09-01

Transcriptional activation of erythropoietin, glycolytic enzymes, and vascular endothelial growth factor occurs during hypoxia or in response to cobalt chloride (CoCl2) in Hep3B cells. However, neither the mechanism of cellular O2 sensing nor that of cobalt is fully understood. We tested whether mitochondria act as O2 sensors during hypoxia and whether hypoxia and cobalt activate transcription by increasing generation of reactive oxygen species (ROS). Results show (i) wild-type Hep3B cells increase ROS generation during hypoxia (1.5% O2) or CoCl2 incubation, (ii) Hep3B cells depleted of mitochondrial DNA (ρ 0 cells) fail to respire, fail to activate mRNA for erythropoietin, glycolytic enzymes, or vascular endothelial growth factor during hypoxia, and fail to increase ROS generation during hypoxia; (iii) ρ 0 cells increase ROS generation in response to CoCl2 and retain the ability to induce expression of these genes; and (iv) the antioxidants pyrrolidine dithiocarbamate and ebselen abolish transcriptional activation of these genes during hypoxia or CoCl2 in wild-type cells, and abolish the response to CoCl2 in ρ 0 cells. Thus, hypoxia activates transcription via a mitochondria-dependent signaling process involving increased ROS, whereas CoCl2 activates transcription by stimulating ROS generation via a mitochondria-independent mechanism.

Pulsed infrared difference frequency generation in CdGeAs.sub.2

DOEpatents

Piltch, Martin S.; Rink, John P.; Tallman, Charles R.

1977-03-08

The disclosure relates to a laser apparatus for generating a line-tunable pulsed infrared difference frequency output. The apparatus comprises a CO.sub.2 laser which produces a first frequency, a CO laser which produces a second frequency and a mixer for combining the output of the CO.sub.2 and CO lasers so as to produce a final output comprising a difference frequency from the first and second frequency outputs.

Pulsed infrared difference frequency generation in CdGeAs/sub 2/

DOEpatents

Piltch, M.S.; Rink, J.P.; Tallman, C.R.

1975-11-26

A laser apparatus for generating a line-tunable pulsed infrared difference frequency output is described. The apparatus comprises a CO/sub 2/ laser which produces a first frequency, a CO laser which produces a second frequency, and a mixer for combining the output of the CO/sub 2/ and CO lasers so as to produce a final output comprising a difference frequency from the first and second frequency outputs.

Treatment plan comparison between Tri-Co-60 magnetic-resonance image-guided radiation therapy and volumetric modulated arc therapy for prostate cancer

PubMed Central

Park, Jong Min; Park, So-Yeon; Choi, Chang Heon; Chun, Minsoo; Kim, Jin Ho; Kim, Jung-In

2017-01-01

To investigate the plan quality of tri-Co-60 intensity-modulated radiation therapy (IMRT) with magnetic-resonance image-guided radiation therapy compared with volumetric-modulated arc therapy (VMAT) for prostate cancer. Twenty patients with intermediate-risk prostate cancer, who received radical VMAT were selected. Additional tri-Co-60 IMRT plans were generated for each patient. Both primary and boost plans were generated with tri-Co-60 IMRT and VMAT techniques. The prescription doses of the primary and boost plans were 50.4 Gy and 30.6 Gy, respectively. The primary and boost planning target volumes (PTVs) of the tri-Co-60 IMRT were generated with 3 mm margins from the primary clinical target volume (CTV, prostate + seminal vesicle) and a boost CTV (prostate), respectively. VMAT had a primary planning target volume (primary CTV + 1 cm or 2 cm margins) and a boost PTV (boost CTV + 0.7 cm margins), respectively. For both tri-Co-60 IMRT and VMAT, all the primary and boost plans were generated that 95% of the target volumes would be covered by the 100% of the prescription doses. Sum plans were generated by summation of primary and boost plans. In sum plans, the average values of V70 Gy of the bladder of tri-Co-60 IMRT vs. VMAT were 4.0% ± 3.1% vs. 10.9% ± 6.7%, (p < 0.001). Average values of V70 Gy of the rectum of tri-Co-60 IMRT vs. VMAT were 5.2% ± 1.8% vs. 19.1% ± 4.0% (p < 0.001). The doses of tri-Co-60 IMRT delivered to the bladder and rectum were smaller than those of VMAT while maintaining identical target coverage in both plans. PMID:29207634

Effect of CoQ homologues on reactive oxygen generation by mitochondria.

PubMed

Imada, Isuke; Sato, Eisuke F; Kira, Yukimi; Inoue, Masayasu

2008-01-01

Effect of CoQ compounds (Qs) on reactive oxygen (ROS) generation by mitochondrial complex I was studied using rat liver mitochondria and chemiluminescence probe L012. Kinetic analysis revealed that short chain Qs, such as Q2 and idebenone enhanced ROS generation by mitochondrial NADH oxidase system by a succinate-inhibitable mechanism. Lipid peroxidation in mitochondrial membranes induced by NADH and iron was inhibited by short chain Qs. The inhibitory activity was enhanced by co-oxidation of succinate as determined by chemiluminescence method and by electron spin resonance spectroscopy. These results suggested that the reduced form of short chain Qs inhibited mitochondrial ROS generation and lipid peroxidation.

Power generation using spinel manganese-cobalt oxide as a cathode catalyst for microbial fuel cell applications.

PubMed

Mahmoud, Mohamed; Gad-Allah, Tarek A; El-Khatib, K M; El-Gohary, Fatma

2011-11-01

This study focused on the use of spinel manganese-cobalt (Mn-Co) oxide, prepared by a solid state reaction, as a cathode catalyst to replace platinum in microbial fuel cells (MFCs) applications. Spinel Mn-Co oxides, with an Mn/Co atomic ratios of 0.5, 1, and 2, were prepared and examined in an air cathode MFCs which was fed with a molasses-laden synthetic wastewater and operated in batch mode. Among the three Mn-Co oxide cathodes and after 300 h of operation, the Mn-Co oxide catalyst with Mn/Co atomic ratio of 2 (MnCo-2) exhibited the highest power generation 113 mW/m2 at cell potential of 279 mV, which were lower than those for the Pt catalyst (148 mW/m2 and 325 mV, respectively). This study indicated that using spinel Mn-Co oxide to replace platinum as a cathodic catalyst enhances power generation, increases contaminant removal, and substantially reduces the cost of MFCs. Copyright © 2011 Elsevier Ltd. All rights reserved.

Relation of peer effects and school climate to substance use among Asian American adolescents.

PubMed

Ryabov, Igor

2015-07-01

Using a nationally representative, longitudinal sample of Asian American late adolescents/young adults (ages 18-26), this article investigates the link between peer effects, school climate, on the one hand, and substance use, which includes tobacco, alcohol, and other illicit mood altering substance. The sample (N = 1585) is drawn from the National Longitudinal Study of Adolescent Health (Waves I and III). The study is set to empirically test premises of generational, social capital and stage-environment fit theories. The exploratory variables include individual-level (immigrant generation status, ethnic origin, co-ethnic and co-generational peers - peers from the same immigrant generation) as well as school-level measures (average school socio-economic status and school climate). Multilevel modeling (logistic and negative binomial regression) was used to estimate substance use. Results indicate that preference for co-generational friends is inversely associated with frequency of cannabis and other illicit drug use and preference for co-ethnic peers is inversely associated with other illicit drug use. We also find that school climate is a strong and negative predictor of frequency of cannabis and other illicit drug use as well as of heavy episodic drinking. In terms of policy, these findings suggest that Asian American students should benefit from co-ethnic and co-generational peer networks in schools and, above all, from improving school climate. Copyright © 2015 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Analyses of the Integration of Carbon Dioxide Removal Assembly, Compressor, Accumulator and Sabatier Carbon Dioxide Reduction Assembly

NASA Technical Reports Server (NTRS)

Jeng, Frank F.; Lafuse, Sharon; Smith, Frederick D.; Lu, Sao-Dung; Knox, James C.; Campbell, Mellssa L.; Scull, Timothy D.; Green Steve

2010-01-01

A tool has been developed by the Sabatier Team for analyzing/optimizing CO2 removal assembly, CO2 compressor size, its operation logic, water generation from Sabatier, utilization of CO2 from crew metabolic output, and Hz from oxygen generation assembly. Tests had been conducted using CDRA/Simulation compressor set-up at MSFC in 2003. Analysis of test data has validated CO2 desorption rate profile, CO2 compressor performance, CO2 recovery and CO2 vacuum vent in CDRA desorption. Optimizing the compressor size and compressor operation logic for an integrated closed air revitalization system Is being conducted by the Sabatier Team.

The Role of Electrode-Catalyst Interactions in Enabling Efficient CO2 Reduction with Mo(bpy)(CO)4 As Revealed by Vibrational Sum-Frequency Generation Spectroscopy.

PubMed

Neri, Gaia; Donaldson, Paul M; Cowan, Alexander J

2017-10-04

Group 6 metal carbonyl complexes ([M(bpy)(CO) 4 ], M = Cr, Mo, W) are potentially promising CO 2 reduction electrocatalysts. However, catalytic activity onsets at prohibitively negative potentials and is highly dependent on the nature of the working electrode. Here we report in situ vibrational SFG (VSFG) measurements of the electrocatalyst [Mo(bpy)(CO) 4 ] at platinum and gold electrodes. The greatly improved onset potential for electrocatalytic CO 2 reduction at gold electrodes is due to the formation of the catalytically active species [Mo(bpy)(CO) 3 ] 2- via a second pathway at more positive potentials, likely avoiding the need for the generation of [Mo(bpy)(CO) 4 ] 2- . VSFG studies demonstrate that the strength of the interaction between initially generated [Mo(bpy)(CO) 4 ] •- and the electrode is critical in enabling the formation of the active catalyst via the low energy pathway. By careful control of electrode material, solvent and electrolyte salt, it should therefore be possible to attain levels of activity with group 6 complexes equivalent to their much more widely studied group 7 analogues.

A Summary of Research and Progress on Carbon Monoxide Exposure Control Solutions on Houseboats

PubMed Central

Hall, Ronald M.; Earnest, G. Scott; Hammond, Duane R.; Dunn, Kevin H.; Garcia, Alberto

2015-01-01

Investigations of carbon monoxide (CO-related poisonings and deaths on houseboats were conducted by the Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health. These investigations measured hazardous CO concentrations on and around houseboats that utilize gasoline-powered generators. Engineering control devices were developed and tested to mitigate this deadly hazard. CO emissions were measured using various sampling techniques which included exhaust emission analyzers, detector tubes, evacuated containers (grab air samples analyzed by a gas chromatograph), and direct-reading CO monitors. CO results on houseboats equipped with gasoline-powered generators without emission controls indicated hazardous CO concentrations exceeding immediately dangerous to life and health (IDLH) levels in potentially occupied areas of the houseboat. Air sample results on houseboats that were equipped with engineering controls to remove the hazard were highly effective and reduced CO levels by over 98% in potentially occupied areas. The engineering control devices used to reduce the hazardous CO emissions from gasoline-powered generators on houseboats were extremely effective at reducing CO concentrations to safe levels in potentially occupied areas on the houseboats and are now beginning to be widely used. PMID:24568306

A summary of research and progress on carbon monoxide exposure control solutions on houseboats.

PubMed

Hall, Ronald M; Earnest, G Scott; Hammond, Duane R; Dunn, Kevin H; Garcia, Alberto

2014-01-01

Investigations of carbon monoxide (CO-related poisonings and deaths on houseboats were conducted by the Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health. These investigations measured hazardous CO concentrations on and around houseboats that utilize gasoline-powered generators. Engineering control devices were developed and tested to mitigate this deadly hazard. CO emissions were measured using various sampling techniques which included exhaust emission analyzers, detector tubes, evacuated containers (grab air samples analyzed by a gas chromatograph), and direct-reading CO monitors. CO results on houseboats equipped with gasoline-powered generators without emission controls indicated hazardous CO concentrations exceeding immediately dangerous to life and health (IDLH) levels in potentially occupied areas of the houseboat. Air sample results on houseboats that were equipped with engineering controls to remove the hazard were highly effective and reduced CO levels by over 98% in potentially occupied areas. The engineering control devices used to reduce the hazardous CO emissions from gasoline-powered generators on houseboats were extremely effective at reducing CO concentrations to safe levels in potentially occupied areas on the houseboats and are now beginning to be widely used.

Evolution of co-management: role of knowledge generation, bridging organizations and social learning.

PubMed

Berkes, Fikret

2009-04-01

Over a period of some 20 years, different aspects of co-management (the sharing of power and responsibility between the government and local resource users) have come to the forefront. The paper focuses on a selection of these: knowledge generation, bridging organizations, social learning, and the emergence of adaptive co-management. Co-management can be considered a knowledge partnership. Different levels of organization, from local to international, have comparative advantages in the generation and mobilization of knowledge acquired at different scales. Bridging organizations provide a forum for the interaction of these different kinds of knowledge, and the coordination of other tasks that enable co-operation: accessing resources, bringing together different actors, building trust, resolving conflict, and networking. Social learning is one of these tasks, essential both for the co-operation of partners and an outcome of the co-operation of partners. It occurs most efficiently through joint problem solving and reflection within learning networks. Through successive rounds of learning and problem solving, learning networks can incorporate new knowledge to deal with problems at increasingly larger scales, with the result that maturing co-management arrangements become adaptive co-management in time.

Generation of energetic, picosecond seed pulses for CO2 laser using Raman shifter

NASA Astrophysics Data System (ADS)

Welch, Eric; Tochitsky, Sergei; Joshi, Chan

2017-03-01

We present a new concept for generating 3 ps seed pulses for a high-power CO2 laser amplifier that are multiple orders more energetic than seed pulses generated by slicing from a nanosecond CO2 laser pulse. We propose to send a 1 µm picosecond laser through a C6D6 Raman shifter and mix both the pump and shifted components in a DFG crystal to produce pulses at 10.6 µm. Preliminary results of a proof-of-principle experiment are presented.

Production of Excess CO2 relative to methane in peatlands: a new H2 sink

NASA Astrophysics Data System (ADS)

Wilson, R.; Woodcroft, B. J.; Varner, R. K.; Tyson, G. W.; Tfaily, M. M.; Sebestyen, S.; Saleska, S. R.; Rogers, K.; Rich, V. I.; McFarlane, K. J.; Kostka, J. E.; Kolka, R. K.; Keller, J.; Iversen, C. M.; Hodgkins, S. B.; Hanson, P. J.; Guilderson, T. P.; Griffiths, N.; de La Cruz, F.; Crill, P. M.; Chanton, J.; Bridgham, S. D.; Barlaz, M.

2015-12-01

Methane is generated as the end product of anaerobic organic matter degradation following a series of reaction pathways including fermentation and syntrophy. Along with acetate and CO2, syntrophic reactions generate H2 and are only thermodynamically feasible when coupled to an exothermic reaction that consumes H2. The usual model of organic matter degradation in peatlands has assumed that methanogenesis is that exothermic H2-consuming reaction. If correct, this paradigm should ultimately result in equimolar production of CO2 and methane from the degradation of the model organic compound cellulose: i.e. C6H12O6 à 3CO2 + 3CH4. However, dissolved gas measurement and modeling results from field and incubation experiments spanning peatlands across the northern hemisphere have failed to demonstrate equimolar production of CO2 and methane. Instead, in a flagrant violation of thermodynamics, these studies show a large bias favoring CO2 production over methane generation. In this talk, we will use an array of complementary analytical techniques including FT-IR, cellulose and lignin measurements, 13C-NMR, fluorescence spectroscopy, and ultra-high resolution mass spectrometry to describe organic matter degradation within a peat column and identify the important degradation mechanisms. Hydrogenation was the most common transformation observed in the ultra-high resolution mass spectrometry data. From these results we propose a new mechanism for consuming H2 generated during CO2 production, without concomitant methane formation, consistent with observed high CO2/CH4 ratios. While homoacetogenesis is a known sink for H2 in these systems, this process also consumes CO2 and therefore does not explain the excess CO2 measured in field and incubation samples. Not only does the newly proposed mechanism consume H2 without generating methane, but it also yields enough energy to balance the coupled syntrophic reactions, thereby restoring thermodynamic order. Schematic of organic matter degradation. Solid lines indicate traditional pathways from Conrad (1999), dashed lines indicates new proposed mechanism.

Evaluation of relative effects of carbohydrate sources in yeast-fermentation CO2 generators on mosquito surveillance

USDA-ARS?s Scientific Manuscript database

In order to collect mosquitoes in remote locations that do not have access to attractive lures, such as CO2 (i.e., dry ice or compressed gas), a natural method to generate CO2 on-site has been developed. Our research explored alternative sugar sources such as honey, molasses, and granulated sugar u...

Resource potential for renewable energy generation from co-firing of woody biomass with coal in the Northern U.S.

Treesearch

Michael E. Goerndt; Francisco X. Aguilar; Kenneth Skog

2013-01-01

Past studies have established measures of co-firing potential at varying spatial scales to assess opportunities for renewable energy generation from woody biomass. This study estimated physical availability, within ecological and public policy constraints, and associated harvesting and delivery costs of woody biomass for co-firing in selected power plants of the...

Explore various co-substrates for simultaneous electricity generation and Congo red degradation in air-cathode single-chamber microbial fuel cell.

PubMed

Cao, Yunqing; Hu, Yongyou; Sun, Jian; Hou, Bin

2010-08-01

Microbial fuel cell (MFC) holds a great promise to harvest electricity directly from a wide range of ready degradable organic matters and enhance degradation of some recalcitrant contaminants. Glucose, acetate sodium and ethanol were separately examined as co-substrates for simultaneous bioelectricity generation and Congo red degradation in a proton exchange membrane (PEM) air-cathode single-chamber MFC. The batch test results showed that more than 98% decolorization at the dye concentration of 300 mg/L were achieved within 36 h for all tested co-substrates during electricity generation. The decolorization rate was different with the co-substrates used. The fastest decolorization rate was achieved with glucose followed by ethanol and sodium acetate. Accumulated intermediates were observed during Congo red degradation which was demonstrated by UV-Visible spectra and high performance liquid chromatography (HPLC). Electricity generation was sustained and not significantly affected by the Congo red degradation. Glucose, acetate sodium and ethanol produced maximum power densities of 103 mW/m(2), 85.9 mW/m(2) and 63.2 mW/m(2), respectively, and the maximum voltage output decreased by only 7% to 15%. Our results demonstrated the feasibility of using various co-substrates for simultaneous decolorization of Congo red and bioelectricity generation in the MFC and showed that glucose was the preferred co-substrate. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Terahertz generation by relativistic ponderomotive focusing of two co-axial Gaussian laser beams propagating in ripple density plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Subodh; Singh, Ram Kishor, E-mail: ram007kishor@gmail.com; Sharma, R. P.

Terahertz (THz) generation by beating of two co-axial Gaussian laser beams, propagating in ripple density plasma, has been studied when both ponderomotive and relativistic nonlinearities are operative. When the two lasers co-propagate in rippled density plasma, electrons acquire a nonlinear velocity at beat frequency in the direction transverse to the direction of propagation. This nonlinear oscillatory velocity couples with the density ripple to generate a nonlinear current, which in turn generates THz radiation at the difference frequency. The necessary phase matching condition is provided by the density ripple. Relativistic ponderomotive focusing of the two lasers and its effects on yieldmore » of the generated THz amplitude have been discussed. Numerical results show that conversion efficiency of the order of 10{sup −3} can be achieved in the terahertz radiation generation with relativistic ponderomotive focusing.« less

CO2 microbubble contrast enhancement in x-ray angiography.

PubMed

Kariya, S; Komemushi, A; Nakatani, M; Yoshida, R; Sawada, S; Tanigawa, N

2013-04-01

To demonstrate that carbon dioxide (CO2) microbubble contrast enhancement depicts blood vessels when used for x-ray examinations. Microbubbles were generated by cavitation of physiological saline to which CO2 gas had been added using an ejector-type microbubble generator. The input pressure values for CO2 gas and physiological saline that produced a large quantity of CO2 microbubbles were obtained in a phantom. In an animal study, angiography was performed in three swine using three types of contrast: CO2 microbubbles, conventional CO2 gas, and iodinated contrast medium. For CO2 microbubble contrast enhancement, physiological saline, and CO2 gas were supplied at the input pressures calculated in the phantom experiment. Regions of interest were set in the abdominal aorta, external iliac arteries, and background. The difference in digital values between each artery and the background was calculated. The input pressures obtained in the phantom experiment were 0.16 MPa for physiological saline and 0.5 MPa for CO2 gas, with physiological saline input volume being 8.1 ml/s. Three interventional radiologists all evaluated the depictions of all arteries as "present" in the CO2 microbubble contrast enhancement, conventional CO2 contrast enhancement, and iodinated contrast enhancement performed in three swine. Digital values for all vessels with microbubble CO2 contrast enhancement were higher than background values. In x-ray angiography, blood vessels can be depicted by CO2 microbubble contrast enhancement, in which a large quantity of CO2 microbubbles is generated within blood vessels. Copyright © 2012 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

A computational model-based validation of Guyton's analysis of cardiac output and venous return curves

NASA Technical Reports Server (NTRS)

Mukkamala, R.; Cohen, R. J.; Mark, R. G.

2002-01-01

Guyton developed a popular approach for understanding the factors responsible for cardiac output (CO) regulation in which 1) the heart-lung unit and systemic circulation are independently characterized via CO and venous return (VR) curves, and 2) average CO and right atrial pressure (RAP) of the intact circulation are predicted by graphically intersecting the curves. However, this approach is virtually impossible to verify experimentally. We theoretically evaluated the approach with respect to a nonlinear, computational model of the pulsatile heart and circulation. We developed two sets of open circulation models to generate CO and VR curves, differing by the manner in which average RAP was varied. One set applied constant RAPs, while the other set applied pulsatile RAPs. Accurate prediction of intact, average CO and RAP was achieved only by intersecting the CO and VR curves generated with pulsatile RAPs because of the pulsatility and nonlinearity (e.g., systemic venous collapse) of the intact model. The CO and VR curves generated with pulsatile RAPs were also practically independent. This theoretical study therefore supports the validity of Guyton's graphical analysis.

Configurable Cellular Automata for Pseudorandom Number Generation

NASA Astrophysics Data System (ADS)

Quieta, Marie Therese; Guan, Sheng-Uei

This paper proposes a generalized structure of cellular automata (CA) — the configurable cellular automata (CoCA). With selected properties from programmable CA (PCA) and controllable CA (CCA), a new approach to cellular automata is developed. In CoCA, the cells are dynamically reconfigured at run-time via a control CA. Reconfiguration of a cell simply means varying the properties of that cell with time. Some examples of properties to be reconfigured are rule selection, boundary condition, and radius. While the objective of this paper is to propose CoCA as a new CA method, the main focus is to design a CoCA that can function as a good pseudorandom number generator (PRNG). As a PRNG, CoCA can be a suitable candidate as it can pass 17 out of 18 Diehard tests with 31 cells. CoCA PRNG's performance based on Diehard test is considered superior over other CA PRNG works. Moreover, CoCA opens new rooms for research not only in the field of random number generation, but in modeling complex systems as well.

Evaluation of the coordination preferences and catalytic pathways of heteroaxial cobalt oximes towards hydrogen generation

DOE PAGES

Basu, Debashis; Mazumder, Shivnath; Niklas, Jens; ...

2016-02-02

Three new heteroaxial cobalt oxime catalysts, namely [Co III(prdioxH)( 4tBupy)(Cl)]PF 6 (1), [Co III(prdioxH)( 4Pyrpy)(Cl)]PF 6 (2), and [Co III(prdioxH)( 4Bzpy)(Cl)]PF 6 (3) have been studied. These species contain chloro and substituted tert-butyl/pyrrolidine/benzoyl-pyridino ligands axially coordinated to a trivalent cobalt ion bound to the N 4-oxime macrocycle (2 E,2' E,3 E,3' E)-3,3'-(propane-1,3-diylbis(azanylylidene))bis(butan-2-one)dioxime, abbreviated (prdioxH)– in its monoprotonated form. Emphasis was given to the spectroscopic investigation of the coordination preferences and spin configurations among the different 3d 6 Co III, 3d 7 Co II, and 3d 8 Co I oxidation states of the metal, and to the catalytic proton reduction withmore » an evaluation of the pathways for the generation of H 2 via Co III–H – or Co II–H – intermediates by mono and bimetallic routes. The strong field imposed by the (prdioxH)– ligand precludes the existence of high-spin configurations, and 6-coordinate geometry is favored by the LSCo III species. Species 1 and 3 show a split Co III/Co II electrochemical wave associated with partial chemical conversion to a [Co III(prdioxH)Cl 2] species, whereas 2 shows a single event. The reduction of these Co III complexes yields LSCo II and LSCo I species in which the pyridine acts as the dominant axial ligand. In the presence of protons, the catalytically active Co I species generates a Co III–H – hydride species that reacts heterolytically with another proton to generate dihydrogen. The intermediacy of a trifluoroacetate-bound Co III/Co II couple in the catalytic mechanism is proposed. Finally, these results allow for a generalization of the behavior of heteroaxial cobalt macrocycles and serve as guidelines for the development of new catalysts based on macrocyclic frameworks.« less

Co3 O4 Nanowire Arrays toward Superior Water Oxidation Electrocatalysis in Alkaline Media by Surface Amorphization.

PubMed

Zhou, Dan; He, Liangbo; Zhang, Rong; Hao, Shuai; Hou, Xiandeng; Liu, Zhiang; Du, Gu; Asiri, Abdullah M; Zheng, Chengbin; Sun, Xuping

2017-11-07

It is highly desirable to develop a simple, fast and straightforward method to boost the alkaline water oxidation of metal oxide catalysts. In this communication, we report our recent finding that the generation of amorphous Co-borate layer on Co 3 O 4 nanowire arrays supported on Ti mesh (Co 3 O 4 @Co-Bi NA/TM) leads to significantly boosted OER activity. The as-prepared Co 3 O 4 @Co-Bi NA/TM demands overpotential of 304 mV to drive a geometrical current density of 20 mA cm -2 in 1.0 M KOH, which is 109 mV less than that for Co 3 O 4 NA/TM, with its catalytic activity being preserved for at least 20 h. It suggests that the existence of amorphous Co-Bi layer promotes more CoO x (OH) y generation on Co 3 O 4 surface. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

An interplay between plasticity and parental phenotype determines impacts of ocean acidification on a reef fish.

PubMed

Schunter, Celia; Welch, Megan J; Nilsson, Göran E; Rummer, Jodie L; Munday, Philip L; Ravasi, Timothy

2018-02-01

The impacts of ocean acidification will depend on the ability of marine organisms to tolerate, acclimate and eventually adapt to changes in ocean chemistry. Here, we use a unique transgenerational experiment to determine the molecular response of a coral reef fish to short-term, developmental and transgenerational exposure to elevated CO 2 , and to test how these responses are influenced by variations in tolerance to elevated CO 2 exhibited by the parents. Within-generation responses in gene expression to end-of-century predicted CO 2 levels indicate that a self-amplifying cycle in GABAergic neurotransmission is triggered, explaining previously reported neurological and behavioural impairments. Furthermore, epigenetic regulator genes exhibited a within-generation specific response, but with some divergence due to parental phenotype. Importantly, we find that altered gene expression for the majority of within-generation responses returns to baseline levels following parental exposure to elevated CO 2 conditions. Our results show that both parental variation in tolerance and cross-generation exposure to elevated CO 2 are crucial factors in determining the response of reef fish to changing ocean chemistry.

Inherent variations in CO-H2S-mediated carotid body O2 sensing mediate hypertension and pulmonary edema

PubMed Central

Peng, Ying-Jie; Makarenko, Vladislav V.; Nanduri, Jayasri; Vasavda, Chirag; Raghuraman, Gayatri; Yuan, Guoxiang; Gadalla, Moataz M.; Kumar, Ganesh K.; Snyder, Solomon H.; Prabhakar, Nanduri R.

2014-01-01

Oxygen (O2) sensing by the carotid body and its chemosensory reflex is critical for homeostatic regulation of breathing and blood pressure. Humans and animals exhibit substantial interindividual variation in this chemosensory reflex response, with profound effects on cardiorespiratory functions. However, the underlying mechanisms are not known. Here, we report that inherent variations in carotid body O2 sensing by carbon monoxide (CO)-sensitive hydrogen sulfide (H2S) signaling contribute to reflex variation in three genetically distinct rat strains. Compared with Sprague-Dawley (SD) rats, Brown-Norway (BN) rats exhibit impaired carotid body O2 sensing and develop pulmonary edema as a consequence of poor ventilatory adaptation to hypobaric hypoxia. Spontaneous Hypertensive (SH) rat carotid bodies display inherent hypersensitivity to hypoxia and develop hypertension. BN rat carotid bodies have naturally higher CO and lower H2S levels than SD rat, whereas SH carotid bodies have reduced CO and greater H2S generation. Higher CO levels in BN rats were associated with higher substrate affinity of the enzyme heme oxygenase 2, whereas SH rats present lower substrate affinity and, thus, reduced CO generation. Reducing CO levels in BN rat carotid bodies increased H2S generation, restoring O2 sensing and preventing hypoxia-induced pulmonary edema. Increasing CO levels in SH carotid bodies reduced H2S generation, preventing hypersensitivity to hypoxia and controlling hypertension in SH rats. PMID:24395806

Costs of solar and wind power variability for reducing CO2 emissions.

PubMed

Lueken, Colleen; Cohen, Gilbert E; Apt, Jay

2012-09-04

We compare the power output from a year of electricity generation data from one solar thermal plant, two solar photovoltaic (PV) arrays, and twenty Electric Reliability Council of Texas (ERCOT) wind farms. The analysis shows that solar PV electricity generation is approximately one hundred times more variable at frequencies on the order of 10(-3) Hz than solar thermal electricity generation, and the variability of wind generation lies between that of solar PV and solar thermal. We calculate the cost of variability of the different solar power sources and wind by using the costs of ancillary services and the energy required to compensate for its variability and intermittency, and the cost of variability per unit of displaced CO(2) emissions. We show the costs of variability are highly dependent on both technology type and capacity factor. California emissions data were used to calculate the cost of variability per unit of displaced CO(2) emissions. Variability cost is greatest for solar PV generation at $8-11 per MWh. The cost of variability for solar thermal generation is $5 per MWh, while that of wind generation in ERCOT was found to be on average $4 per MWh. Variability adds ~$15/tonne CO(2) to the cost of abatement for solar thermal power, $25 for wind, and $33-$40 for PV.

Beneficial effects of substituting trivalent ions in the B-site of La0.5Sr0.5Mn1-xAxO3 (A = Al, Ga, Sc) on the thermochemical generation of CO and H2 from CO2 and H2O.

PubMed

Dey, Sunita; Naidu, B S; Rao, C N R

2016-02-14

The effect of substitution of Al(3+), Ga(3+) and Sc(3+) ions in the Mn(3+) site of La0.5Sr0.5MnO3 on the thermochemical splitting of CO2 to generate CO has been studied in detail. Both La0.5Sr0.5Mn1-xGaxO3 and La0.5Sr0.5Mn1-xScxO3 give high yields of O2 and generate CO more efficiently than La0.5Sr0.5Mn1-xAlxO3 or the parent La0.5Sr0.5MnO3. Substitution of even 5% Sc(3+) (x = 0.05) results in a remarkable improvement in performance. Thus La0.5Sr0.5Mn0.95Sc0.05O3 produces 417 μmol g(-1) of O2 and 545 μmol g(-1) of CO, respectively, i.e. 2 and 1.7 times more O2 and CO than La0.5Sr0.5MnO3. This manganite also generates H2 satisfactorily by the thermochemical splitting of H2O.

Development of a Next-Generation Membrane-Integrated Adsorption Processor for CO2 Removal and Compression for Closed-Loop Air Revitalization Systems

NASA Technical Reports Server (NTRS)

Mulloth, Lila; LeVan, Douglas

2002-01-01

The current CO2 removal technology of NASA is very energy intensive and contains many non-optimized subsystems. This paper discusses the concept of a next-generation, membrane integrated, adsorption processor for CO2 removal nd compression in closed-loop air revitalization systems. This processor will use many times less power than NASA's current CO2 removal technology and will be capable of maintaining a lower CO2 concentration in the cabin than that can be achieved by the existing CO2 removal systems. The compact, consolidated, configuration of gas dryer, CO2 separator, and CO2 compressor will allow continuous recycling of humid air in the cabin and supply of compressed CO2 to the reduction unit for oxygen recovery. The device has potential application to the International Space Station and future, long duration, transit, and planetary missions.

75 FR 33855 - Sunshine Federal Register Notice

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-15

.... Entergy Nuclear Generation Co. and Entergy Nuclear Operations, Inc. (Pilgrim Nuclear Power Station) Remaining Issues from Pilgrim Watch Petition for Review (Tentative). b. Entergy Nuclear Generation Co. and...-case basis. * * * * * This notice is distributed electronically to subscribers. If you no longer wish...

Combining XCO2 Measurements Derived from SCIAMACHY and GOSAT for Potentially Generating Global CO2 Maps with High Spatiotemporal Resolution

PubMed Central

Wang, Tianxing; Shi, Jiancheng; Jing, Yingying; Zhao, Tianjie; Ji, Dabin; Xiong, Chuan

2014-01-01

Global warming induced by atmospheric CO2 has attracted increasing attention of researchers all over the world. Although space-based technology provides the ability to map atmospheric CO2 globally, the number of valid CO2 measurements is generally limited for certain instruments owing to the presence of clouds, which in turn constrain the studies of global CO2 sources and sinks. Thus, it is a potentially promising work to combine the currently available CO2 measurements. In this study, a strategy for fusing SCIAMACHY and GOSAT CO2 measurements is proposed by fully considering the CO2 global bias, averaging kernel, and spatiotemporal variations as well as the CO2 retrieval errors. Based on this method, a global CO2 map with certain UTC time can also be generated by employing the pattern of the CO2 daily cycle reflected by Carbon Tracker (CT) data. The results reveal that relative to GOSAT, the global spatial coverage of the combined CO2 map increased by 41.3% and 47.7% on a daily and monthly scale, respectively, and even higher when compared with that relative to SCIAMACHY. The findings in this paper prove the effectiveness of the combination method in supporting the generation of global full-coverage XCO2 maps with higher temporal and spatial sampling by jointly using these two space-based XCO2 datasets. PMID:25119468

U.S. Energy Sector Impacts of Technology Innovation, Fuel Price, and Electric Sector CO 2 Policy: Results from the EMF 32 Model Intercomparison Study

DOE PAGES

Hodson, Elke L.; Brown, Maxwell; Cohen, Stuart; ...

2018-03-22

We study the impact of fuel prices, technology innovation, and a CO 2 emissions reduction policy on both the electric power and end-use sectors by comparing outputs from four U.S. energyeconomic models through the year 2050. Achieving innovation goals decreases CO 2 emissions in all models, regardless of natural gas price, due to increased energy efficiency and low-carbon generation becoming more cost competitive. For the models that include domestic natural gas markets, achieving innovation goals lowers wholesale electricity prices, but this effect diminishes as projected natural gas prices increase. Higher natural gas prices lead to higher wholesale electricity prices butmore » fewer coal capacity retirements. A CO 2 electric power sector emissions cap influences electric sector evolution under reference technology assumptions but has little to no incremental influence when added to innovation goals. Long-term, meeting innovation goals achieves a generation mix with similar CO 2 emissions compared to the CO 2 policy but with smaller increases to wholesale electricity prices. In the short-term, the relative effect on wholesale prices differs by model. Finally, higher natural gas prices, achieving innovation goals, and the combination of the two, increases the amount of renewable generation that is cost-effective to build and operate while slowing the growth of natural-gas fired generation, which is the predominant generation type in 2050 under reference conditions.« less

U.S. Energy Sector Impacts of Technology Innovation, Fuel Price, and Electric Sector CO 2 Policy: Results from the EMF 32 Model Intercomparison Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hodson, Elke L.; Brown, Maxwell; Cohen, Stuart

We study the impact of fuel prices, technology innovation, and a CO 2 emissions reduction policy on both the electric power and end-use sectors by comparing outputs from four U.S. energyeconomic models through the year 2050. Achieving innovation goals decreases CO 2 emissions in all models, regardless of natural gas price, due to increased energy efficiency and low-carbon generation becoming more cost competitive. For the models that include domestic natural gas markets, achieving innovation goals lowers wholesale electricity prices, but this effect diminishes as projected natural gas prices increase. Higher natural gas prices lead to higher wholesale electricity prices butmore » fewer coal capacity retirements. A CO 2 electric power sector emissions cap influences electric sector evolution under reference technology assumptions but has little to no incremental influence when added to innovation goals. Long-term, meeting innovation goals achieves a generation mix with similar CO 2 emissions compared to the CO 2 policy but with smaller increases to wholesale electricity prices. In the short-term, the relative effect on wholesale prices differs by model. Finally, higher natural gas prices, achieving innovation goals, and the combination of the two, increases the amount of renewable generation that is cost-effective to build and operate while slowing the growth of natural-gas fired generation, which is the predominant generation type in 2050 under reference conditions.« less

Carbon Dioxide Emissions Effects of Grid-Scale Electricity Storage in a Decarbonizing Power System

DOE PAGES

Craig, Michael T.; Jaramillo, Paulina; Hodge, Bri-Mathias

2018-01-03

While grid-scale electricity storage (hereafter 'storage') could be crucial for deeply decarbonizing the electric power system, it would increase carbon dioxide (CO 2) emissions in current systems across the United States. To better understand how storage transitions from increasing to decreasing system CO 2 emissions, we quantify the effect of storage on operational CO 2 emissions as a power system decarbonizes under a moderate and strong CO 2 emission reduction target through 2045. Under each target, we compare the effect of storage on CO 2 emissions when storage participates in only energy, only reserve, and energy and reserve markets. Wemore » conduct our study in the Electricity Reliability Council of Texas (ERCOT) system and use a capacity expansion model to forecast generator fleet changes and a unit commitment and economic dispatch model to quantify system CO 2 emissions with and without storage. We find that storage would increase CO 2 emissions in the current ERCOT system, but would decrease CO 2 emissions in 2025 through 2045 under both decarbonization targets. Storage reduces CO 2 emissions primarily by enabling gas-fired generation to displace coal-fired generation, but also by reducing wind and solar curtailment. We further find that the market in which storage participates drives large differences in the magnitude, but not the direction, of the effect of storage on CO 2 emissions.« less

Carbon Dioxide Emissions Effects of Grid-Scale Electricity Storage in a Decarbonizing Power System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Craig, Michael T.; Jaramillo, Paulina; Hodge, Bri-Mathias

While grid-scale electricity storage (hereafter 'storage') could be crucial for deeply decarbonizing the electric power system, it would increase carbon dioxide (CO 2) emissions in current systems across the United States. To better understand how storage transitions from increasing to decreasing system CO 2 emissions, we quantify the effect of storage on operational CO 2 emissions as a power system decarbonizes under a moderate and strong CO 2 emission reduction target through 2045. Under each target, we compare the effect of storage on CO 2 emissions when storage participates in only energy, only reserve, and energy and reserve markets. Wemore » conduct our study in the Electricity Reliability Council of Texas (ERCOT) system and use a capacity expansion model to forecast generator fleet changes and a unit commitment and economic dispatch model to quantify system CO 2 emissions with and without storage. We find that storage would increase CO 2 emissions in the current ERCOT system, but would decrease CO 2 emissions in 2025 through 2045 under both decarbonization targets. Storage reduces CO 2 emissions primarily by enabling gas-fired generation to displace coal-fired generation, but also by reducing wind and solar curtailment. We further find that the market in which storage participates drives large differences in the magnitude, but not the direction, of the effect of storage on CO 2 emissions.« less

Carbon dioxide emissions effects of grid-scale electricity storage in a decarbonizing power system

NASA Astrophysics Data System (ADS)

Craig, Michael T.; Jaramillo, Paulina; Hodge, Bri-Mathias

2018-01-01

While grid-scale electricity storage (hereafter ‘storage’) could be crucial for deeply decarbonizing the electric power system, it would increase carbon dioxide (CO2) emissions in current systems across the United States. To better understand how storage transitions from increasing to decreasing system CO2 emissions, we quantify the effect of storage on operational CO2 emissions as a power system decarbonizes under a moderate and strong CO2 emission reduction target through 2045. Under each target, we compare the effect of storage on CO2 emissions when storage participates in only energy, only reserve, and energy and reserve markets. We conduct our study in the Electricity Reliability Council of Texas (ERCOT) system and use a capacity expansion model to forecast generator fleet changes and a unit commitment and economic dispatch model to quantify system CO2 emissions with and without storage. We find that storage would increase CO2 emissions in the current ERCOT system, but would decrease CO2 emissions in 2025 through 2045 under both decarbonization targets. Storage reduces CO2 emissions primarily by enabling gas-fired generation to displace coal-fired generation, but also by reducing wind and solar curtailment. We further find that the market in which storage participates drives large differences in the magnitude, but not the direction, of the effect of storage on CO2 emissions.

Carbon Monoxide Poisoning After an Ice Storm in Kentucky, 2009

PubMed Central

Lutterloh, Emily C.; Iqbal, Shahed; Clower, Jacquelyn H.; Spillerr, Henry A.; Riggs, Margaret A.; Sugg, Tennis J.; Humbaugh, Kraig E.; Cadwell, Betsy L.; Thoroughman, Douglas A.

2011-01-01

Objectives. Carbon monoxide (CO) poisoning is a leading cause of morbidity and mortality during natural disasters. On January 26–27, 2009, a severe ice storm occurred in Kentucky, causing widespread, extended power outages and disrupting transportation and communications. After the storm, CO poisonings were reported throughout the state. The objectives of this investigation were to determine the extent of the problem, identify sources of CO poisoning, characterize cases, make recommendations to reduce morbidity and mortality, and develop prevention strategies. Methods. We obtained data from the Kentucky Regional Poison Center (KRPC), hyperbaric oxygen treatment (HBOT) facilities, and coroners. Additionally, the Kentucky Department for Public Health provided statewide emergency department (ED) and hospitalization data. Results. During the two weeks after the storm, KRPC identified 144 cases of CO poisoning; exposure sources included kerosene heaters, generators, and propane heaters. Hospitals reported 202 ED visits and 26 admissions. Twenty-eight people received HBOT. Ten deaths were attributed to CO poisoning, eight of which were related to inappropriate generator location. Higher rates of CO poisoning were reported in areas with the most ice accumulation. Conclusions. Although CO poisonings are preventable, they continue to occur in postdisaster situations. Recommendations include encouraging use of CO alarms, exploring use of engineering controls on generators to decrease CO exposure, providing specific information regarding safe use and placement of CO-producing devices, and using multiple communication methods to reach people without electricity. PMID:21563718

Power generation using sugar cane bagasse: A heat recovery analysis

NASA Astrophysics Data System (ADS)

Seguro, Jean Vittorio

The sugar industry is facing the need to improve its performance by increasing efficiency and developing profitable by-products. An important possibility is the production of electrical power for sale. Co-generation has been practiced in the sugar industry for a long time in a very inefficient way with the main purpose of getting rid of the bagasse. The goal of this research was to develop a software tool that could be used to improve the way that bagasse is used to generate power. Special focus was given to the heat recovery components of the co-generation plant (economizer, air pre-heater and bagasse dryer) to determine if one, or a combination, of them led to a more efficient co-generation cycle. An extensive review of the state of the art of power generation in the sugar industry was conducted and is summarized in this dissertation. Based on this models were developed. After testing the models and comparing the results with the data collected from the literature, a software application that integrated all these models was developed to simulate the complete co-generation plant. Seven different cycles, three different pressures, and sixty-eight distributions of the flue gas through the heat recovery components can be simulated. The software includes an economic analysis tool that can help the designer determine the economic feasibility of different options. Results from running the simulation are presented that demonstrate its effectiveness in evaluating and comparing the different heat recovery components and power generation cycles. These results indicate that the economizer is the most beneficial option for heat recovery and that the use of waste heat in a bagasse dryer is the least desirable option. Quantitative comparisons of several possible cycle options with the widely-used traditional back-pressure turbine cycle are given. These indicate that a double extraction condensing cycle is best for co-generation purposes. Power generation gains between 40 and 100% are predicted for some cycles with the addition of optimum heat recovery systems.

77 FR 6150 - Notice of Sunshine Act Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-07

... Status of Outreach and Educational Efforts with External Stakeholders Related to the Safety Culture...). a. Entergy Nuclear Generation Co. and Entergy Nuclear Operations, Inc (Pilgrim Nuclear Power Station). Docket No. 50-293-LR (Tentative). b. Southern Nuclear Operating Co. (Vogtle Electric Generating Plant...

Photoionization of oxidized coenzyme Q in microemulsion: laser flash photolysis study in biomembrane-like system.

PubMed

Li, Kun; Wang, Mei; Wang, Jin; Zhu, Rongrong; Sun, Dongmei; Sun, Xiaoyu; Wang, Shi-Long

2013-01-01

Photoexcitation to generate triplet state has been proved to be the main photoreaction in homogeneous system for many benzoquinone derivatives, including oxidized coenzyme Q (CoQ) and its analogs. In the present study, microemulsion of CoQ, a heterogeneous system, is employed to mimic the distribution of CoQ in biomembrane. The photochemistry of CoQ(10) in microemulsion and cyclohexane is investigated and compared using laser flash photolysis and results show that CoQ(10) undergoes photoionization via a monophotonic process to generate radical cation of CoQ(10) in microemulsion and photoexcitation to generate excited triplet state in cyclohexane. Meanwhile, photoreactions of duroquinone (DQ) and CoQ(0) in microemulsion are also investigated to analyze the influence of molecular structure on the photochemistry of benzoquinone derivatives in microemulsion. Results suggest that photoexcitation, which is followed by excited state-involved hydrogen-abstraction reaction, is the main photoreaction for DQ and CoQ(0) in microemulsion. However, photoexcited CoQ(0) also leads to the formation of hydrated electrons. The isoprenoid side chain-involved high resonance stabilization is proposed to explain the difference in photoreactions of CoQ(0) and CoQ(10) in microemulsion. Considering that microemulsion is close to biomembrane system, its photoionization in microemulsion may be helpful to understand the real photochemistry of biological quinones in biomembrane system. © 2012 Tongji University. Photochemistry and Photobiology © 2012 The American Society of Photobiology.

Formation of carbon monoxide during mouse hepatic microsomal oxidative metabolism of cannabidiol; identification and determination.

PubMed

Usami, N; Tateoka, Y; Watanabe, K; Yamamoto, I; Yoshimura, H

1995-04-01

Carbon monoxide (CO) was generated in the process of hepatic microsomal oxidative metabolism of cannabidiol (CBD). After the generated CO was reduced to methane (CH4) with a methanizer, CH4 formed was determined by gas chromatography (GC) with a flame ionization detector. After oxidation with hopcalite, CO was also identified as CO2 by gas chromatography/mass spectrometry (GC/MS). The reaction was NADPH-dependent and required molecular oxygen. It was inhibited by addition of some inhibitors of cytochrome P450-dependent monooxygenase. When CBD (191 microM) was incubated with hepatic microsomes of mice in the presence of an NADPH-generating system and oxygen, concentration of CO determined by GC was 4.7 +/- 0.5 ppm/nmol P450 in the incubation atmosphere. Pretreatment with phenobarbital (100 mg/kg, i.p. for 3d) but not 3-methylcholanthrene (80 mg/kg, i.p.) increased the CO formation 78%, while pretreatment with cobaltous chloride (40 mg/kg, i.p. for 3 d) decreased the formation 56%. When CBD was incubated under oxygen-18 gas, molecular oxygen was not incorporated into the CO molecule. 8,9-Dihydro- and 1,2,8,9-tetrahydro-CBDs also produced CO to some extent, whereas CBD monomethyl- and dimethylethers reduced the ability to produce CO. In addition, cannabidivarin and olivetol produced CO, although none of delta 9-tetrahydrocannabinol, cannabinol and d-limonene did. Thus, the resorcinol moiety of CBD is important for CO formation.

U.S. energy sector impacts of technology innovation, fuel price, and electric sector CO 2 policy: Results from the EMF 32 model intercomparison study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hodson, Elke L.; Brown, Maxwell; Cohen, Stuart

We study the impact of achieving technology innovation goals, representing significant technology cost reductions and performance improvements, in both the electric power and end-use sectors by comparing outputs from four energy-economic models through the year 2050. We harmonize model input assumptions and then compare results in scenarios that vary natural gas prices, technology cost and performance metrics, and the implementation of a representative national electricity sector carbon dioxide (CO 2) policy. Achieving the representative technology innovation goals decreases CO 2 emissions in all models, regardless of natural gas price, due to increased energy efficiency and low-carbon generation becoming more costmore » competitive. For the models that include domestic natural gas markets, achieving the technology innovation goals lowers wholesale electricity prices, but this effect diminishes as projected natural gas prices increase. Higher natural gas prices lead to higher wholesale electricity prices but fewer coal capacity retirements. Some of the models include energy efficiency improvements as part of achieving the high-technology goals. Absent these energy efficiency improvements, low-cost electricity facilitates greater electricity consumption. The effect of implementing a representative electricity sector CO 2 policy differs considerably depending on the cost and performance of generating and end-use technologies. The CO 2 policy influences electric sector evolution in the cases with reference technology assumptions but has little to no influence in the cases that achieve the technology innovation goals. This outcome implies that meeting the representative technology innovation goals achieves a generation mix with similar CO 2 emissions to the representative CO 2 policy but with smaller increases to wholesale electricity prices. Finally, higher natural gas prices, achieving the representative technology innovation goals, and the combination of the two, increases the amount of renewable generation that is cost-effective to build and operate while slowing the growth of natural-gas fired generation, which is the predominant generation type in 2050 under reference conditions.« less

Risk assessment of geo-microbial assosicated CO2 Geological Storage

NASA Astrophysics Data System (ADS)

Tanaka, A.; Sakamoto, Y.; Higashino, H.; Mayumi, D.; Sakata, S.; Kano, Y.; Nishi, Y.; Nakao, S.

2014-12-01

If we maintain preferable conditions for methanogenesis archaea during geological CCS, we will be able to abate greenhouse gas emission and produce natural gas as natural energy resource at the same time. Assuming Bio-CCS site, CO2 is injected from a well for to abate greenhouse gas emission and cultivate methanogenic geo-microbes, and CH4 is produced from another well. The procedure is similar to the Enhanced Oil/Gas Recovery (EOR/EGR) operation, but in Bio-CCS, the target is generation and production of methane out of depleted oil/gas reservoir during CO2 abatement. Our project aims to evaluate the basic practicability of Bio-CCS that cultivate methanogenic geo-microbes within depleted oil/gas reservoirs for geological CCS, and produce methane gas as fuel resources on the course of CO2 abatement for GHG control. To evaluate total feasibility of Bio-CCS concept, we have to estimate: CH4 generation volume, environmental impact along with life cycle of injection well, and risk-benefit balance of the Bio-CCS. We are modifying the model step by step to include interaction of oil/gas-CO2-geomicrobe within reservoir more practically and alternation of geo-microbes generation, so that we will be able to estimate methane generation rate more precisely. To evaluate impacts of accidental events around Bio-CCS reservoir, we estimated CO2 migration in relation with geological properties, condition of faults and pathways around well, using TOUGH2-CO2 simulator. All findings will be integrated in to it: cultivation condition of methanogenic geo-microbes, estimation method of methane generation quantities, environmental impacts of various risk scenarios, and benefit analysis of schematic site of Bio-CCS.

Quantification of CO2 generation in sedimentary basins through carbonate/clays reactions with uncertain thermodynamic parameters

NASA Astrophysics Data System (ADS)

Ceriotti, G.; Porta, G. M.; Geloni, C.; Dalla Rosa, M.; Guadagnini, A.

2017-09-01

We develop a methodological framework and mathematical formulation which yields estimates of the uncertainty associated with the amounts of CO2 generated by Carbonate-Clays Reactions (CCR) in large-scale subsurface systems to assist characterization of the main features of this geochemical process. Our approach couples a one-dimensional compaction model, providing the dynamics of the evolution of porosity, temperature and pressure along the vertical direction, with a chemical model able to quantify the partial pressure of CO2 resulting from minerals and pore water interaction. The modeling framework we propose allows (i) estimating the depth at which the source of gases is located and (ii) quantifying the amount of CO2 generated, based on the mineralogy of the sediments involved in the basin formation process. A distinctive objective of the study is the quantification of the way the uncertainty affecting chemical equilibrium constants propagates to model outputs, i.e., the flux of CO2. These parameters are considered as key sources of uncertainty in our modeling approach because temperature and pressure distributions associated with deep burial depths typically fall outside the range of validity of commonly employed geochemical databases and typically used geochemical software. We also analyze the impact of the relative abundancy of primary phases in the sediments on the activation of CCR processes. As a test bed, we consider a computational study where pressure and temperature conditions are representative of those observed in real sedimentary formation. Our results are conducive to the probabilistic assessment of (i) the characteristic pressure and temperature at which CCR leads to generation of CO2 in sedimentary systems, (ii) the order of magnitude of the CO2 generation rate that can be associated with CCR processes.

Enabling CCS via Low-temperature Geothermal Energy Integration for Fossil-fired Power Generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davidson, Casie L.; Heldebrant, D. J.; Bearden, M. D.

Here, among the key barriers to commercial scale deployment is the cost associated with CO 2 capture. This is particularly true for existing large, fossil-fired assets that account for a large fraction of the electricity generation fleet in developed nations, including the U.S. Fitting conventional combustion technologies with CO 2 capture systems can carry an energy penalty of thirty percent or more, resulting in an increased price of power to the grid, as well as an overall decrease in net plant output. Taken together with the positive growth in demand for electricity, this implies a need for accelerated capital build-outmore » in the power generation markets to accommodate both demand growth and decreased output at retrofitted plants. In this paper, the authors present the results of a study to assess the potential to use geothermal energy to provide boiler feedwater preheating, capturing efficiency improvements designed to offset the losses associated with CO 2 capture. Based on NETL benchmark cases and subsequent analysis of the application using site-specific data from the North Valmy power plant, several cases for CO 2 capture were evaluated. These included geothermally assisted MEA capture, CO2BOLs capture, and stand-alone hybrid power generation, compared with a baseline, no-geothermal case. Based on Case 10, and assuming 2.7 MMlb/h of geothermally sourced 150 ºC water, the parasitic power load associated with MEA capture could be offset by roughly seven percent, resulting in a small (~1 percent) overall loss to net power generation, but at levelized costs of electricity similar to the no-geothermal CCS case. For the CO 2BOLs case, the availability of 150°C geothermal fluid could allow the facility to not only offset the net power decrease associated with CO 2BOLs capture alone, but could increase nameplate capacity by two percent. The geothermally coupled CO 2BOLs case also decreases LCOE by 0.75 ¢/kWh relative to the non-hybrid CO 2BOLs case, with the improved performance over the MEA case driven by the lower regeneration temperature and associated duty for CO 2BOLs relative to MEA.« less

Enabling CCS via Low-temperature Geothermal Energy Integration for Fossil-fired Power Generation

DOE PAGES

Davidson, Casie L.; Heldebrant, D. J.; Bearden, M. D.; ...

2017-08-18

Here, among the key barriers to commercial scale deployment is the cost associated with CO 2 capture. This is particularly true for existing large, fossil-fired assets that account for a large fraction of the electricity generation fleet in developed nations, including the U.S. Fitting conventional combustion technologies with CO 2 capture systems can carry an energy penalty of thirty percent or more, resulting in an increased price of power to the grid, as well as an overall decrease in net plant output. Taken together with the positive growth in demand for electricity, this implies a need for accelerated capital build-outmore » in the power generation markets to accommodate both demand growth and decreased output at retrofitted plants. In this paper, the authors present the results of a study to assess the potential to use geothermal energy to provide boiler feedwater preheating, capturing efficiency improvements designed to offset the losses associated with CO 2 capture. Based on NETL benchmark cases and subsequent analysis of the application using site-specific data from the North Valmy power plant, several cases for CO 2 capture were evaluated. These included geothermally assisted MEA capture, CO2BOLs capture, and stand-alone hybrid power generation, compared with a baseline, no-geothermal case. Based on Case 10, and assuming 2.7 MMlb/h of geothermally sourced 150 ºC water, the parasitic power load associated with MEA capture could be offset by roughly seven percent, resulting in a small (~1 percent) overall loss to net power generation, but at levelized costs of electricity similar to the no-geothermal CCS case. For the CO 2BOLs case, the availability of 150°C geothermal fluid could allow the facility to not only offset the net power decrease associated with CO 2BOLs capture alone, but could increase nameplate capacity by two percent. The geothermally coupled CO 2BOLs case also decreases LCOE by 0.75 ¢/kWh relative to the non-hybrid CO 2BOLs case, with the improved performance over the MEA case driven by the lower regeneration temperature and associated duty for CO 2BOLs relative to MEA.« less

A Biomimetic Nickel Complex with a Reduced CO2 Ligand Generated by Formate Deprotonation and Its Behaviour towards CO2.

PubMed

Zimmermann, Philipp; Hoof, Santina; Braun-Cula, Beatrice; Herwig, Christian; Limberg, Christian

2018-04-10

Reduced CO 2 species are key intermediates in a variety of natural and synthetic processes. In the majority of systems, however, they elude isolation or characterisation owing to high reactivity or limited accessibility (heterogeneous systems), and their formulations thus often remain uncertain or are based on calculations only. We herein report on a Ni-CO 2 2- complex that is unique in many ways. While its structural and electronic features help understand the CO 2 -bound state in Ni,Fe carbon monoxide dehydrogenases, its reactivity sheds light on how CO 2 can be converted into CO/CO 3 2- by nickel complexes. In addition, the complex was generated by a rare example of formate β-deprotonation, a mechanistic step relevant to the nickel-catalysed conversion of H x CO y z- at electrodes and formate oxidation in formate dehydrogenases. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Metallopolymer precursors to L10-CoPt nanoparticles: synthesis, characterization, nanopatterning and potential application

NASA Astrophysics Data System (ADS)

Dong, Qingchen; Qu, Wenshan; Liang, Wenqing; Guo, Kunpeng; Xue, Haibin; Guo, Yuanyuan; Meng, Zhengong; Ho, Cheuk-Lam; Leung, Chi-Wah; Wong, Wai-Yeung

2016-03-01

Ferromagnetic (L10 phase) CoPt alloy nanoparticles (NPs) with extremely high magnetocrystalline anisotropy are promising candidates for the next generation of ultrahigh-density data storage systems. It is a challenge to generate L10 CoPt NPs with high coercivity, controllable size, and a narrow size distribution. We report here the fabrication of L10 CoPt NPs by employing a heterobimetallic CoPt-containing polymer as a single-source precursor. The average size of the resulting L10 CoPt NPs is 3.4 nm with a reasonably narrow size standard deviation of 0.58 nm. The coercivity of L10 CoPt NPs is 0.54 T which is suitable for practical application. We also fabricated the L10 CoPt NP-based nanoline and nanodot arrays through nanoimprinting the polymer blend of CoPt-containing metallopolymer and polystyrene followed by pyrolysis. The successful transfer of the pre-defined patterns of the stamps onto the surface of the polymer blend implies that this material holds great application potential as a data storage medium.Ferromagnetic (L10 phase) CoPt alloy nanoparticles (NPs) with extremely high magnetocrystalline anisotropy are promising candidates for the next generation of ultrahigh-density data storage systems. It is a challenge to generate L10 CoPt NPs with high coercivity, controllable size, and a narrow size distribution. We report here the fabrication of L10 CoPt NPs by employing a heterobimetallic CoPt-containing polymer as a single-source precursor. The average size of the resulting L10 CoPt NPs is 3.4 nm with a reasonably narrow size standard deviation of 0.58 nm. The coercivity of L10 CoPt NPs is 0.54 T which is suitable for practical application. We also fabricated the L10 CoPt NP-based nanoline and nanodot arrays through nanoimprinting the polymer blend of CoPt-containing metallopolymer and polystyrene followed by pyrolysis. The successful transfer of the pre-defined patterns of the stamps onto the surface of the polymer blend implies that this material holds great application potential as a data storage medium. Electronic supplementary information (ESI) available: PXRD, EDX and SEM original data. See DOI: 10.1039/c6nr00034g

Heterologous production of an energy-conserving carbon monoxide dehydrogenase complex in the hyperthermophile Pyrococcus furiosus

DOE PAGES

Schut, Gerrit J.; Lipscomb, Gina L.; Nguyen, Diep M. N.; ...

2016-01-29

In this study, carbon monoxide (CO) is an important intermediate in anaerobic carbon fixation pathways in acetogenesis and methanogenesis. In addition, some anaerobes can utilize CO as an energy source. In the hyperthermophilic archaeon Thermococcus onnurineus, which grows optimally at 80°C, CO oxidation and energy conservation is accomplished by a respiratory complex encoded by a 16-gene cluster containing a CO dehydrogenase, a membrane-bound [NiFe]-hydrogenase and a Na +/H + antiporter module. This complex oxidizes CO, evolves CO 2 and H 2, and generates a Na+ motive force that is used to conserve energy by a Na+-dependent ATP synthase. Herein wemore » used a bacterial artificial chromosome to insert the 13.2 kb gene cluster encoding the CO-oxidizing respiratory complex of T. onnurineus into the genome of the heterotrophic archaeon, Pyrococcus furiosus, which grows optimally at 100° C. P. furiosus is normally unable to utilize CO, however, the recombinant strain readily oxidized CO and generated H 2 at 80° C. Moreover, CO also served as an energy source and allowed the P. furiosus strain to grow with a limiting concentration of sugar or with peptides as the carbon source. Moreover, CO oxidation by P. furiosus was also coupled to the re-utilization, presumably for biosynthesis, of acetate generated by fermentation. The functional transfer of CO utilization between Thermococcus and Pyrococcus species demonstrated herein is representative of the horizontal gene transfer of an environmentally relevant metabolic capability. The transfer of CO utilizing, hydrogen-producing genetic modules also has applications for biohydrogen production and a CO-based industrial platform for various thermophilic organisms.« less

coq7/clk-1 regulates mitochondrial respiration and the generation of reactive oxygen species via coenzyme Q.

PubMed

Nakai, Daisuke; Shimizu, Takahiko; Nojiri, Hidetoshi; Uchiyama, Satoshi; Koike, Hideo; Takahashi, Mayumi; Hirokawa, Katsuiku; Shirasawa, Takuji

2004-10-01

coq7/clk-1 was isolated from a long-lived mutant of Caenorhabditis elegans, and shows sluggish behaviours and an extended lifespan. In C. elegans and Saccharomyces cerevisiae, coq7/clk-1 is required for the biosynthesis of coenzyme Q (CoQ), an essential co-factor in mitochondrial respiration. The clk-1 mutant contains dietary CoQ(8) from Escherichia coli and demethoxyubiquinone 9 (DMQ9) instead of CoQ(9). In a previous study, we generated COQ7-deficient mice by targeted disruption of the coq7 gene and reported that mouse coq7/clk-1 is also essential for CoQ synthesis, maintenance of mitochondrial integrity and neurogenesis. In the present study, we rescued COQ7-deficient mice from embryonic lethality and established a mouse model with decreased CoQ level by transgene expression of COQ7/CLK-1. A biochemical analysis showed a concomitant decrease in CoQ(9), mitochondrial respiratory enzyme activity and the generation of reactive oxygen species (ROS) in the mitochondria of CoQ-insufficient mice. This implied that the depressed activity of respiratory enzymes and the depressed production of ROS may play a physiological role in the control of lifespan in mammalian species and of C. elegans.

High-power microwave production by gyroharmonic conversion and co-generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

LaPointe, M.A.; Yoder, R.B.; Wang, M.

1997-03-01

An rf accelerator that adds significant gyration energy to a relativistic electron beam, and mechanisms for extracting coherent radiation from the beam, are described. The accelerator is a cyclotron autoresonance accelerator (CARA), underlying theory and experimental tests of which are reviewed. The measurements illustrate the utility of CARA in preparing beams for high harmonic gyro interactions. Examples of preparation of gyrating axis-encircling beams of {approximately}400kV, 25 A with 1{lt}a{lt}2 using a 2.856 GHz CARA are discussed. Generation of MW-level harmonic power emanating from a beam prepared in CARA into an output cavity structure is predicted by theory. First measurements ofmore » intense superradiant 2nd through 6th harmonic emission from a CARA beam are described. Gyroharmonic conversion (GHC) at MW power levels into an appropriate resonator can be anticipated, in view of the results described here. Another radiation mechanism, closely related to GHC, is also described. This mechanism, dubbed {open_quotes}co-generation,{close_quotes} is based on the fact that the lowest TE{sub sm} mode in a cylindrical waveguide at frequency sw with group velocity nearly identical to group velocity for the TE{sub 11} mode at frequency w is that with s=7, m=2. This allows coherent radiation to be generated at the 7th harmonic co-existent with CARA and in the self-same rf structure. Conditions are found where co-generation of 7th harmonic power at 20 GHz is possible with overall efficiency greater than 80{percent}. It is shown that operation of a cw co-generator can take place without need of a power supply for the gun. Efficiency for a multi-MW 20 GHz co-generator is predicted to be high enough to compete with other sources, even after taking into account the finite efficiency of the rf driver required for CARA. {copyright} {ital 1997 American Institute of Physics.}« less

Simulation of CO2 Solubility in Polystyrene-b-Polybutadieneb-Polystyrene (SEBS) by artificial intelligence network (ANN) method

NASA Astrophysics Data System (ADS)

Sharudin, R. W.; AbdulBari Ali, S.; Zulkarnain, M.; Shukri, M. A.

2018-05-01

This study reports on the integration of Artificial Neural Network (ANNs) with experimental data in predicting the solubility of carbon dioxide (CO2) blowing agent in SEBS by generating highest possible value for Regression coefficient (R2). Basically, foaming of thermoplastic elastomer with CO2 is highly affected by the CO2 solubility. The ability of ANN in predicting interpolated data of CO2 solubility was investigated by comparing training results via different method of network training. Regards to the final prediction result for CO2 solubility by ANN, the prediction trend (output generate) was corroborated with the experimental results. The obtained result of different method of training showed the trend of output generated by Gradient Descent with Momentum & Adaptive LR (traingdx) required longer training time and required more accurate input to produce better output with final Regression Value of 0.88. However, it goes vice versa with Levenberg-Marquardt (trainlm) technique as it produced better output in quick detention time with final Regression Value of 0.91.

A carbon-air battery for high power generation.

PubMed

Yang, Binbin; Ran, Ran; Zhong, Yijun; Su, Chao; Tadé, Moses O; Shao, Zongping

2015-03-16

We report a carbon-air battery for power generation based on a solid-oxide fuel cell (SOFC) integrated with a ceramic CO2-permeable membrane. An anode-supported tubular SOFC functioned as a carbon fuel container as well as an electrochemical device for power generation, while a high-temperature CO2-permeable membrane composed of a CO3(2-) mixture and an O(2-) conducting phase (Sm(0.2)Ce(0.8)O(1.9)) was integrated for in situ separation of CO2 (electrochemical product) from the anode chamber, delivering high fuel-utilization efficiency. After modifying the carbon fuel with a reverse Boudouard reaction catalyst to promote the in situ gasification of carbon to CO, an attractive peak power density of 279.3 mW cm(-2) was achieved for the battery at 850 °C, and a small stack composed of two batteries can be operated continuously for 200 min. This work provides a novel type of electrochemical energy device that has a wide range of application potentials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Co-Optimization of Electricity Transmission and Generation Resources for Planning and Policy Analysis: Review of Concepts and Modeling Approaches

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krishnan, Venkat; Ho, Jonathan; Hobbs, Benjamin F.

2016-05-01

The recognition of transmission's interaction with other resources has motivated the development of co-optimization methods to optimize transmission investment while simultaneously considering tradeoffs with investments in electricity supply, demand, and storage resources. For a given set of constraints, co-optimized planning models provide solutions that have lower costs than solutions obtained from decoupled optimization (transmission-only, generation-only, or iterations between them). This paper describes co-optimization and provides an overview of approaches to co-optimizing transmission options, supply-side resources, demand-side resources, and natural gas pipelines. In particular, the paper provides an up-to-date assessment of the present and potential capabilities of existing co-optimization tools, andmore » it discusses needs and challenges for developing advanced co-optimization models.« less

Analysis of carbon dioxide emission of gas fuelled cogeneration plant

NASA Astrophysics Data System (ADS)

Nordin, Adzuieen; Amin, M.; Majid, A.

2013-12-01

Gas turbines are widely used for power generation. In cogeneration system, the gas turbine generates electricity and the exhaust heat from the gas turbine is used to generate steam or chilled water. Besides enhancing the efficiency of the system, the process assists in reducing the emission of CO2 to the environment. This study analyzes the amount of CO2 emission by Universiti Teknologi Petronas gas fuelled cogeneration system using energy balance equations. The results indicate that the cogeneration system reduces the CO2 emission to the environment by 60%. This finding could encourage the power plant owners to install heat recovery systems to their respective plants.

Isolation, observation, and computational modeling of proposed intermediates in catalytic proton reductions with the hydrogenase mimic Fe2(CO)6S2C6H4.

PubMed

Wright, Robert J; Zhang, Wei; Yang, Xinzheng; Fasulo, Meg; Tilley, T Don

2012-01-07

Proposed electrocatalytic proton reduction intermediates of hydrogenase mimics were synthesized, observed, and studied computationally. A new mechanism for H(2) generation appears to involve Fe(2)(CO)(6)(1,2-S(2)C(6)H(4)) (3), the dianions {[1,2-S(2)C(6)H(4)][Fe(CO)(3)(μ-CO)Fe(CO)(2)](2-) (3(2-)), the bridging hydride {[1,2-S(2)C(6)H(4)][Fe(CO)(3)(μ-CO)(μ-H)Fe(CO)(2)]}(-), 3H(-)(bridging), and the terminal hydride 3H(-)(term-stag), {[1,2-S(2)C(6)H(4)][HFe(CO)(3)Fe(CO)(3)]}(-), as intermediates. The dimeric sodium derivative of 3(2-), {[Na(2)(THF)(OEt(2))(3)][3(2-)]}(2) (4) was isolated from reaction of Fe(2)(CO)(6)(1,2-S(2)C(6)H(4)) (3) with excess sodium and was characterized by X-ray crystallography. It possesses a bridging CO and an unsymmetrically bridging dithiolate ligand. Complex 4 reacts with 4 equiv. of triflic or benzoic acid (2 equiv. per Fe center) to generate H(2) and 3 in 75% and 60% yields, respectively. Reaction of 4 with 2 equiv. of benzoic acid generated two hydrides in a 1.7 : 1 ratio (by (1)H NMR spectroscopy). Chemical shift calculations on geometry optimized structures of possible hydride isomers strongly suggest that the main product, 3H(-)(bridging), possesses a bridging hydride ligand, while the minor product is a terminal hydride, 3H(-)(term-stag). Computational studies support a catalytic proton reduction mechanism involving a two-electron reduction of 3 that severs an Fe-S bond to generate a dangling thiolate and an electron rich Fe center. The latter iron center is the initial site of protonation, and this event is followed by protonation at the dangling thiolate to give the thiol thiolate [Fe(2)H(CO)(6)(1,2-SHSC(6)H(4))]. This species then undergoes an intramolecular acid-base reaction to form a dihydrogen complex that loses H(2) and regenerates 3.

An investigation of the uniform random number generator

NASA Technical Reports Server (NTRS)

Temple, E. C.

1982-01-01

Most random number generators that are in use today are of the congruential form X(i+1) + AX(i) + C mod M where A, C, and M are nonnegative integers. If C=O, the generator is called the multiplicative type and those for which C/O are called mixed congruential generators. It is easy to see that congruential generators will repeat a sequence of numbers after a maximum of M values have been generated. The number of numbers that a procedure generates before restarting the sequence is called the length or the period of the generator. Generally, it is desirable to make the period as long as possible. A detailed discussion of congruential generators is given. Also, several promising procedures that differ from the multiplicative and mixed procedure are discussed.

Radial Microchannel Reactor (RMR) used in Steam Reforming CH4

DTIC Science & Technology

2013-05-13

process on land and at sea will reduce CO2 emission and enable cost reductions in the generation of energy in many small market economies. Peter R...size of GTL process on land and at sea will reduce CO2 emission and enable cost reductions in the generation of energy in many small market ...distribution of a 3.3:1 steam-methane mixture at 750 °C and 11 bar is: H2 45.8%, H2O 36.99%, CO 6.365%, CO2 6.681% and CH4 4.14% Barring any coking , this

Carbon monoxide poisoning in Florida during the 2004 hurricane season.

PubMed

Van Sickle, David; Chertow, Daniel S; Schulte, Joann M; Ferdinands, Jill M; Patel, Prakash S; Johnson, David R; Harduar-Morano, Laurel; Blackmore, Carina; Ourso, Andre C; Cruse, Kelly M; Dunn, Kevin H; Moolenaar, Ronald L

2007-04-01

During August-September 2004, four major hurricanes hit Florida, resulting in widespread power outages affecting several million households. Carbon monoxide (CO) poisonings during this period were investigated to identify ways to prevent future poisoning. Medical records from ten hospitals (two with hyperbaric oxygen chambers) were reviewed to identify individuals diagnosed with unintentional CO poisoning between August 13 and October 15, 2004. Multiple attempts were made to interview one person from each nonfatal incident. Medical examiner records and reports of investigations conducted by the U.S. Consumer Product Safety Commission of six fatal poisonings from five additional incidents were also reviewed. A total of 167 people treated for nonfatal CO poisoning were identified, representing 51 incidents. A portable, gasoline-powered generator was implicated in nearly all nonfatal incidents and in all fatal poisonings. Generators were most often located outdoors, followed by inside the garage, and inside the home. Telephone interviews with representatives of 35 (69%) incidents revealed that concerns about theft or exhaust most often influenced the choice of location. Twenty-six (74%) households did not own a generator before the hurricanes, and 86% did not have a CO detector at the time of the poisoning. Twenty-one (67%) households reported reading or hearing CO education messages before the incident. Although exposure to public education messages may have encouraged more appropriate use of generators, a substantial number of people were poisoned even when the devices were operated outdoors. Additional educational efforts and engineering solutions that reduce CO emission from generators should be the focus of public health activities.

Enhanced methane generation during theromophilic co-digestion of confectionary waste and grease-trap fats and oils with municipal wastewater sludge.

PubMed

Gough, Heidi L; Nelsen, Diane; Muller, Christopher; Ferguson, John

2013-02-01

Recent interest in carbon-neutral biofuels has revived interest in co-digestion for methane generation. At wastewater treatment facilities, organic wastes may be co-digested with sludge using established anaerobic digesters. However, changes to organic loadings may induce digester instability, particularly for thermophilic digesters. To examine this problem, thermophilic (55 degrees C) co-digestion was studied for two food-industry wastes in semi-continuous laboratory digesters; in addition, the wastes' biochemical methane potentials were tested. Wastes with high chemical oxygen demand (COD) content were selected as feedstocks allowing increased input of potential energy to reactors without substantially altering volumetric loadings. Methane generation increased while reactor pH and volatile solids remained stable. Lag periods observed prior to methane stimulation suggested that acclimation of the microbial community may be critical to performance during co-digestion. Chemical oxygen demand mass balances in the experimental and control reactors indicated that all of the food industry waste COD was converted to methane.

Formation of Carbamate Anions by the Gas-phase Reaction of Anilide Ions with CO2

NASA Astrophysics Data System (ADS)

Liu, Chongming; Nishshanka, Upul; Attygalle, Athula B.

2016-05-01

The anilide anion ( m/z 92) generated directly from aniline, or indirectly as a fragmentation product of deprotonated acetanilide, captures CO2 readily to form the carbamate anion ( m/z 136) in the collision cell, when CO2 is used as the collision gas in a tandem-quadrupole mass spectrometer. The gas-phase affinity of the anilide ion to CO2 is significantly higher than that of the phenoxide anion ( m/z 93), which adds to CO2 only very sluggishly. Our results suggest that the efficacy of CO2 capture depends on the natural charge density on the nitrogen atom, and relative nucleophilicity of the anilide anion. Generally, conjugate bases generated from aniline derivatives with proton affinities (PA) less than 350 kcal/mol do not tend to add CO2 to form gaseous carbamate ions. For example, the anion generated from p-methoxyaniline (PA = 367 kcal/mol) reacts significantly faster than that obtained from p-nitroaniline (PA = 343 kcal/mol). Although deprotonated p-aminobenzoic acid adds very poorly because the negative charge is now located primarily on the carboxylate group, it reacts more efficiently with CO2 if the carboxyl group is esterified. Moreover, mixture of CO2 and He as the collision gas was found to afford more efficient adduct formation than CO2 alone, or as mixtures made with nitrogen or argon, because helium acts as an effective "cooling" gas and reduces the internal energy of reactant ions.

Net air emissions from electric vehicles: the effect of carbon price and charging strategies.

PubMed

Peterson, Scott B; Whitacre, J F; Apt, Jay

2011-03-01

Plug-in hybrid electric vehicles (PHEVs) may become part of the transportation fleet on time scales of a decade or two. We calculate the electric grid load increase and emissions due to vehicle battery charging in PJM and NYISO with the current generation mix, the current mix with a $50/tonne CO(2) price, and this case but with existing coal generators retrofitted with 80% CO(2) capture. We also examine all new generation being natural gas or wind+gas. PHEV fleet percentages between 0.4 and 50% are examined. Vehicles with small (4 kWh) and large (16 kWh) batteries are modeled with driving patterns from the National Household Transportation Survey. Three charging strategies and three scenarios for future electric generation are considered. When compared to 2020 CAFE standards, net CO(2) emissions in New York are reduced by switching from gasoline to electricity; coal-heavy PJM shows somewhat smaller benefits unless coal units are fitted with CCS or replaced with lower CO(2) generation. NO(X) is reduced in both RTOs, but there is upward pressure on SO(2) emissions or allowance prices under a cap.

α-Amination of aldehydes catalyzed by in situ generated hypoiodite.

PubMed

Tian, Jie-Sheng; Ng, Kang Wai Jeffrey; Wong, Jiun-Ru; Loh, Teck-Peng

2012-09-03

The metal-free amination of different aldehydes is catalyzed by hypoiodite, which is generated by employing commercially available sodium percarbonate as the co-oxidant. This approach has several advantages: it is a metal-free oxidation that works under mild reaction conditions; furthermore, it has a wide substrate scope and does not give toxic by-products from the co-oxidant that is used. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

75 FR 13529 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-22

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Combined Notice of Filings 1 March 15..., 2010. Docket Numbers: ER09-1099-003; ER07-412-004. Applicants: Empire Generating Co, LLC; ECP Energy I, LLC. Description: Quarterly Report of ECP Energy I, LLC, and Empire Generating Co, LLC. Filed Date: 02...

Coal desulfurization. [using iron pentacarbonyl

NASA Technical Reports Server (NTRS)

Hsu, G. C. (Inventor)

1979-01-01

Organic sulfur is removed from coal by treatment with an organic solution of iron pentacarbonyl. Organic sulfur compounds can be removed by reaction of the iron pentacarbonyl with coal to generate CO and COS off-gases. The CO gas separated from COS can be passed over hot iron fillings to generate iron pentacarbonyl.

Area 2. Use Of Engineered Nanoparticle-Stabilized CO 2 Foams To Improve Volumetric Sweep Of CO 2 EOR Processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

DiCarlo, David; Huh, Chun; Johnston, Keith P.

2015-01-31

The goal of this project was to develop a new CO 2 injection enhanced oil recovery (CO 2-EOR) process using engineered nanoparticles with optimized surface coatings that has better volumetric sweep efficiency and a wider application range than conventional CO 2-EOR processes. The main objectives of this project were to (1) identify the characteristics of the optimal nanoparticles that generate extremely stable CO 2 foams in situ in reservoir regions without oil; (2) develop a novel method of mobility control using “self-guiding” foams with smart nanoparticles; and (3) extend the applicability of the new method to reservoirs having a widemore » range of salinity, temperatures, and heterogeneity. Concurrent with our experimental effort to understand the foam generation and transport processes and foam-induced mobility reduction, we also developed mathematical models to explain the underlying processes and mechanisms that govern the fate of nanoparticle-stabilized CO 2 foams in porous media and applied these models to (1) simulate the results of foam generation and transport experiments conducted in beadpack and sandstone core systems, (2) analyze CO 2 injection data received from a field operator, and (3) aid with the design of a foam injection pilot test. Our simulator is applicable to near-injection well field-scale foam injection problems and accounts for the effects due to layered heterogeneity in permeability field, foam stabilizing agents effects, oil presence, and shear-thinning on the generation and transport of nanoparticle-stabilized C/W foams. This report presents the details of our experimental and numerical modeling work and outlines the highlights of our findings.« less

Development of a hybrid photo-bioreactor and nanoparticle adsorbent system for the removal of CO2, and selected organic and metal co-pollutants.

PubMed

Rocha, Andrea A; Wilde, Christian; Hu, Zhenzhong; Nepotchatykh, Oleg; Nazarenko, Yevgen; Ariya, Parisa A

2017-07-01

Fossil fuel combustion and many industrial processes generate gaseous emissions that contain a number of toxic organic pollutants and carbon dioxide (CO 2 ) which contribute to climate change and atmospheric pollution. There is a need for green and sustainable solutions to remove air pollutants, as opposed to conventional techniques which can be expensive, consume additional energy and generate further waste. We developed a novel integrated bioreactor combined with recyclable iron oxide nano/micro-particle adsorption interfaces, to remove CO 2, and undesired organic air pollutants using natural particles, while generating oxygen. This semi-continuous bench-scale photo-bioreactor was shown to successfully clean up simulated emission streams of up to 45% CO 2 with a conversion rate of approximately 4% CO 2 per hour, generating a steady supply of oxygen (6mmol/hr), while nanoparticles effectively remove several undesired organic by-products. We also showed algal waste of the bioreactor can be used for mercury remediation. We estimated the potential CO 2 emissions that could be captured from our new method for three industrial cases in which, coal, oil and natural gas were used. With a 30% carbon capture system, the reduction of CO 2 was estimated to decrease by about 420,000, 320,000 and 240,000 metric tonnes, respectively for a typical 500MW power plant. The cost analysis we conducted showed potential to scale-up, and the entire system is recyclable and sustainable. We further discuss the implications of usage of this complete system, or as individual units, that could provide a hybrid option to existing industrial setups. Copyright © 2016. Published by Elsevier B.V.

The dynamics of a surface plasma generated by an independent source in the field of laser emission

NASA Astrophysics Data System (ADS)

Kovalev, A. S.; Popov, A. M.; Seleznev, B. V.; Feoktistov, V. A.

1986-09-01

A study is made of the evolution of a plasma formation generated by a high-power short pulse of an Nd laser on a metal surface, with the relatively weak emission of a CO2 laser focused on the surface. The thresholds of a sustained breakdown plasma are measured as a function of the plasma-generating pulse energy. The dynamics of plasma front propagation along the target surface and in the direction opposite to the laser beam direction is investigated. It is shown that the use of an additional laser with an energy less than that of the CO2 laser by 2-3 orders of magnitude makes it possible to generate a surface plasma capable of absorbing and transferring to the target a significantly greater fraction of the CO2 laser energy.

A spongy nickel-organic CO2 reduction photocatalyst for nearly 100% selective CO production

PubMed Central

Niu, Kaiyang; Xu, You; Wang, Haicheng; Ye, Rong; Xin, Huolin L.; Lin, Feng; Tian, Chixia; Lum, Yanwei; Bustillo, Karen C.; Doeff, Marca M.; Koper, Marc T. M.; Ager, Joel; Xu, Rong; Zheng, Haimei

2017-01-01

Solar-driven photocatalytic conversion of CO2 into fuels has attracted a lot of interest; however, developing active catalysts that can selectively convert CO2 to fuels with desirable reaction products remains a grand challenge. For instance, complete suppression of the competing H2 evolution during photocatalytic CO2-to-CO conversion has not been achieved before. We design and synthesize a spongy nickel-organic heterogeneous photocatalyst via a photochemical route. The catalyst has a crystalline network architecture with a high concentration of defects. It is highly active in converting CO2 to CO, with a production rate of ~1.6 × 104 μmol hour−1 g−1. No measurable H2 is generated during the reaction, leading to nearly 100% selective CO production over H2 evolution. When the spongy Ni-organic catalyst is enriched with Rh or Ag nanocrystals, the controlled photocatalytic CO2 reduction reactions generate formic acid and acetic acid. Achieving such a spongy nickel-organic photocatalyst is a critical step toward practical production of high-value multicarbon fuels using solar energy. PMID:28782031

Highly vibrationally excited CO generated in a low-temperature chemical reaction between carbon vapor and molecular oxygen

NASA Astrophysics Data System (ADS)

Jans, E.; Frederickson, K.; Yurkovich, M.; Musci, B.; Rich, J. W.; Adamovich, I. V.

2016-08-01

A chemical flow reactor is used to study the vibrational population distribution of CO produced by a reaction between carbon vapor generated in an arc discharge and molecular oxygen. The results demonstrate formation of highly vibrationally excited CO, up to vibrational level v = 14, at low temperatures, T = 400-450 K, with population inversion at v = 4-7, in a collision-dominated environment, 15-20 Torr. The average vibrational energy per CO molecule formed by the reaction is 0.6-1.2 eV/molecule, which corresponds to 10-20% of reaction enthalpy. The results show feasibility of development of a new CO chemical laser using carbon vapor and oxygen as reactants.

Learning to tune the antero-posterior propulsive forces during walking: a necessary skill for mastering upright locomotion in toddlers.

PubMed

Bril, Blandine; Dupuy, Lucile; Dietrich, Gilles; Corbetta, Daniela

2015-10-01

This study examines the process of learning to walk from a functional perspective. To move forward, one must generate and control propulsive forces. To achieve this, it is necessary to create and tune a distance between the centre of mass (CoM) and the centre of pressure (CoP) along the antero-posterior axis. We hypothesize that learning to walk consists of learning how to calibrate these self-generated propulsive forces to control such distance. We investigated this question with six infants (three girls and three boys) who we followed up weekly for the first 8 weeks after the onset of walking and then biweekly until they reached 14-16 weeks of walking experience. The infants' walking patterns (kinematics and propelling forces) were captured via synched motion analysis and force plate. The results show that the distance between the CoM and the CoP along the antero-posterior axis increased rapidly during the first months of learning to walk and that this increase was correlated with an increase in velocity. The initial small values of (CoM-CoP) observed at walking onset, coupled with small velocity are interpreted as the solution infants adopted to satisfy a compromise between the need to generate propulsive forces to move forward while simultaneously controlling the disequilibrium resulting from creating a with distance between the CoM and CoP.

Trend survey of the global environment adaptation type industry technology

NASA Astrophysics Data System (ADS)

1992-03-01

A global CO2 recycling system which combines utilization of natural energy and CO2 recovered from combustion of fossil fuel is studied. In the model, CO2 recovered at the place of energy demand is transported to the place where energy is produced, and from the CO2 fuels are synthesized by use of solar energy and transported to the place of energy demand. Facilities worth a large amount of money are required to transmit electric power generated by the photovoltaic power generation in the desert to the fuel synthesizing plant. Therefore, production of electrolytic hydrogen by the on-site power generation and transport by pipe may be considered. As a synthetic fuel being sent back by ocean transport, methanol is considered, and synthetic methane (LNG) can also be a candidate. CO2 is recovered as liquid carbon dioxide. Possibility of CO2 recycling is dependent on development of the desert solar base, as well as depletion of fossil fuel and price increase, CO2 penalty. It has still been difficult to say which of the fuel synthesis, CO2 tanker or securing of the solar base becomes a bottleneck. Entry of recycling fuels to the market will be possible in proportion to restrictions on fossil fuels, and evaluation of the system depends almost on the rate of energy arriving from the energy-producing region.

Oxygen Generation from Carbon Dioxide for Advanced Life Support

NASA Technical Reports Server (NTRS)

Bishop, Sean; Duncan, Keith; Hagelin-Weaver, Helena; Neal, Luke; Sanchez, Jose; Paul, Heather L.; Wachsman, Eric

2007-01-01

The partial electrochemical reduction of carbon dioxide (CO2) using ceramic oxygen generators (COGs) is well known and widely studied. However, complete reduction of metabolically produced CO2 (into carbon and oxygen) has the potential of reducing oxygen storage weight for life support if the oxygen can be recovered. Recently, the University of Florida devel- oped novel ceramic oxygen generators employing a bilayer elec- trolyte of gadolinia-doped ceria and erbia-stabilized bismuth ox- ide (ESB) for NASA's future exploration of Mars. The results showed that oxygen could be reliably produced from CO2 at temperatures as low as 400 C. The strategy discussed here for advanced life support systems employs a catalytic layer com- bined with a COG cell so that CO2 is reduced all the way to solid carbon and oxygen without carbon buildup on the COG cell and subsequent deactivation.

Enhanced methane yield by co-digestion of sewage sludge with micro-algae and catering waste leachate.

PubMed

2018-04-04

The co-digestion of different wastes is a promising concept to improve methane generation during anaerobic process. However, the anaerobic co-digestion of catering waste leachate with algal biomass and sewage sludge has not been studied to date. This work investigated the methane generation by the anaerobic co-digestion of different mixtures of catering waste leachate, micro-algal biomass, and sewage sludge. Co-digestion of waste mixture containing equal ratios of three substrates had 39.31% higher methane yield than anaerobic digestion of raw sludge. This was possibly due to a proliferation of methanogens during the co-digestion period induced by multi-phase digestion of different wastes with different degrees of digestibility. Therefore, co-digestion of catering waste leachate, micro-algal biomass, and sewage sludge appears to be an efficient technology for energy conversion from waste resources. The scientific application of this co-digestion technology with these three substrates may play a role in solving important environmental issues of waste management.

452nd Brookhaven Lecture. Extreme Environments of Next-Generation Energy Systems and Materials: Can They Peacefully Co-Exist?

ScienceCinema

Simos, Nikolaos

2017-12-22

Nikolaos Simos of Brookhaven’s Energy Sciences and Technology Department and the National Synchrotron Light Source II Project presents, “Extreme Environments of Next-Generation Energy Systems and Materials: Can They Peacefully Co-Exist?”

Alleviating Search Uncertainty through Concept Associations: Automatic Indexing, Co-Occurrence Analysis, and Parallel Computing.

ERIC Educational Resources Information Center

Chen, Hsinchun; Martinez, Joanne; Kirchhoff, Amy; Ng, Tobun D.; Schatz, Bruce R.

1998-01-01

Grounded on object filtering, automatic indexing, and co-occurrence analysis, an experiment was performed using a parallel supercomputer to analyze over 400,000 abstracts in an INSPEC computer engineering collection. A user evaluation revealed that system-generated thesauri were better than the human-generated INSPEC subject thesaurus in concept…

Use of Engineered Exosomes Expressing HLA and Costimulatory Molecules to Generate Antigen-specific CD8+ T Cells for Adoptive Cell Therapy.

PubMed

Kim, Sueon; Sohn, Hyun-Jung; Lee, Hyun-Joo; Sohn, Dae-Hee; Hyun, Seung-Joo; Cho, Hyun-Il; Kim, Tai-Gyu

2017-04-01

Dendritic cell-derived exosomes (DEX) comprise an efficient stimulator of T cells. However, the production of sufficient DEX remains a barrier to their broad applicability in immunotherapeutic approaches. In previous studies, genetically engineered K562 have been used to generate artificial antigen presenting cells (AAPC). Here, we isolated exosomes from K562 cells (referred to as CoEX-A2s) engineered to express human leukocyte antigen (HLA)-A2 and costimulatory molecules such as CD80, CD83, and 41BBL. CoEX-A2s were capable of stimulating antigen-specific CD8 T cells both directly and indirectly via CoEX-A2 cross-dressed cells. Notably, CoEX-A2s also generated similar levels of HCMV pp65-specific and MART1-specific CD8 T cells as DEX in vitro. The results suggest that these novel exosomes may provide a crucial reagent for generating antigen-specific CD8 T cells for adoptive cell therapies against viral infection and tumors.

Acidogenic fermentation of food waste for volatile fatty acid production with co-generation of biohydrogen.

PubMed

Dahiya, Shikha; Sarkar, Omprakash; Swamy, Y V; Venkata Mohan, S

2015-04-01

Fermentation experiments were designed to elucidate the functional role of the redox microenvironment on volatile fatty acid (VFA, short chain carboxylic acid) production and co-generation of biohydrogen (H2). Higher VFA productivity was observed at pH 10 operation (6.3g/l) followed by pH 9, pH 6, pH 5, pH 7, pH 8 and pH 11 (3.5 g/l). High degree of acidification, good system buffering capacity along with co-generation of higher H2 production from food waste was also noticed at alkaline condition. Experiments illustrated the role of initial pH on carboxylic acids synthesis. Alkaline redox conditions assist solubilization of carbohydrates, protein and fats and also suppress the growth of methanogens. Among the carboxylic acids, acetate fraction was higher at alkaline condition than corresponding neutral or acidic operations. Integrated process of VFA production from waste with co-generation of H2 can be considered as a green and sustainable platform for value-addition. Copyright © 2015 Elsevier Ltd. All rights reserved.

Strike-slip earthquakes can also be detected in the ionosphere

NASA Astrophysics Data System (ADS)

Astafyeva, Elvira; Rolland, Lucie M.; Sladen, Anthony

2014-11-01

It is generally assumed that co-seismic ionospheric disturbances are generated by large vertical static displacements of the ground during an earthquake. Consequently, it is expected that co-seismic ionospheric disturbances are only observable after earthquakes with a significant dip-slip component. Therefore, earthquakes dominated by strike-slip motion, i.e. with very little vertical co-seismic component, are not expected to generate ionospheric perturbations. In this work, we use total electron content (TEC) measurements from ground-based GNSS-receivers to study ionospheric response to six recent largest strike-slip earthquakes: the Mw7.8 Kunlun earthquake of 14 November 2001, the Mw8.1 Macquarie earthquake of 23 December 2004, the Sumatra earthquake doublet, Mw8.6 and Mw8.2, of 11 April 2012, the Mw7.7 Balochistan earthquake of 24 September 2013 and the Mw 7.7 Scotia Sea earthquake of 17 November 2013. We show that large strike-slip earthquakes generate large ionospheric perturbations of amplitude comparable with those induced by dip-slip earthquakes of equivalent magnitude. We consider that in the absence of significant vertical static co-seismic displacements of the ground, other seismological parameters (primarily the magnitude of co-seismic horizontal displacements, seismic fault dimensions, seismic slip) may contribute in generation of large-amplitude ionospheric perturbations.

Electricity generation from synthesis gas by microbial processes: CO fermentation and microbial fuel cell technology.

PubMed

Kim, Daehee; Chang, In Seop

2009-10-01

A microbiological process was established to harvest electricity from the carbon monoxide (CO). A CO fermenter was enriched with CO as the sole carbon source. The DGGE/DNA sequencing results showed that Acetobacterium spp. were enriched from the anaerobic digester fluid. After the fermenter was operated under continuous mode, the products were then continuously fed to the microbial fuel cell (MFC) to generate electricity. Even though the conversion yield was quite low, this study proved that synthesis gas (syn-gas) can be converted to electricity with the aid of microbes that do not possess the drawbacks of metal catalysts of conventional methods.

What's in the"'Co"? Tending the Tensions in Co-Creative Inquiry in Social Work Education

ERIC Educational Resources Information Center

Phillips, Louise; Napan, Ksenija

2016-01-01

Higher education is one of many fields of practice that have undergone a so-called "dialogic turn" whereby processes of co-creation proliferate as a means of generating knowledge. According to dialogic ideals, co-creation harnesses the transformative potential of dialogue across difference and empowers participants as co-learners or…

Hierarchical CoP/Ni 5 P 4 /CoP microsheet arrays as a robust pH-universal electrocatalyst for efficient hydrogen generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mishra, Ishwar Kumar; Zhou, Haiqing; Sun, Jingying

Exceptional Pt-like electrocatalytic activity was achieved in a sandwich-like catalyst of CoP/Ni 5 P 4 /CoP microsheet arrays for pH-universal hydrogen evolution through simply wrapping Ni 5 P 4 nanosheet arrays in CoP nanoparticles.

Hierarchical CoP/Ni 5 P 4 /CoP microsheet arrays as a robust pH-universal electrocatalyst for efficient hydrogen generation

DOE PAGES

Mishra, Ishwar Kumar; Zhou, Haiqing; Sun, Jingying; ...

2018-01-01

Exceptional Pt-like electrocatalytic activity was achieved in a sandwich-like catalyst of CoP/Ni 5 P 4 /CoP microsheet arrays for pH-universal hydrogen evolution through simply wrapping Ni 5 P 4 nanosheet arrays in CoP nanoparticles.

Attitudes about carbon monoxide safety in the United States: results from the 2005 and 2006 HealthStyles Survey.

PubMed

King, Michael E; Damon, Scott A

2011-01-01

We sought to identify attitudes and behaviors related to carbon monoxide (CO) safety that can be targeted with public health prevention strategies in the U.S. The Centers for Disease Control and Prevention added questions about (1) proper placement of gas-powered generators, (2) maintenance of fuel-burning appliances, and (3) use of CO detectors to the 2005 and 2006 HealthStyles national health marketing surveys. In 2005, 63.3% of HealthStyles respondents agreed with or were uncertain about the incorrect statement, "It is safe to run a generator in a garage as long as the door is open," while 43.1% agreed with or were uncertain about the incorrect statement, "It is safe to run a generator in the basement." Most of the 2006 respondents (63.5%) agreed that it is important to have their furnace inspected annually. However, fewer than half of the 2006 respondents (42.0%)-most of whom were homeowners-reported owning a CO detector. A large proportion of adults in the U.S. reported attitudes and behaviors that may place them at increased risk for unintentional, non-fire-related CO poisoning, suggesting that current safety messages may not be reaching much of the public. Prevention messages should continue to promote proper generator placement, maintenance of fuel-burning appliances, and use of CO detectors. Development of a comprehensive national strategy for CO surveillance and communication may help identify populations at increased risk and prevent future poisonings.

Preparation of Pd-Co-based nanocatalysts and their superior applications in formic acid decomposition and methanol oxidation.

PubMed

Qin, Yu-ling; Liu, Ya-cheng; Liang, Fei; Wang, Li-min

2015-01-01

Formic acid (FA) and methanol, as convenient hydrogen-containing materials, are most widely used for fuel cells. However, using suitable and low-cost catalysts to further improve their energy performance still is a matter of great significance. Herein, PdCo and PdCo@Pd nanocatalysts (NCs) are successfully prepared by the facile method. Pd 3d binding energy decreases due to the presence of Co. Consequently, PdCo@Pd NCs exhibit high catalytic activity and selectivity toward FA dehydrogenation at room temperature. The gas-generation rate at 30 min is 65.4 L h(-1)  g(-1) . PdCo/C has the worst catalytic performance in this reaction, despite the fact that it has a high gas-generation rate in the initial 30 min. Furthermore, both PdCo and PdCo@Pd NCs have enhanced electrocatalytic performance toward methanol oxidation. Their maximum currents are 966 and 1205 mA mg(-1) , respectively, which is much higher than monometallic Pd/C. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reliability of a new 4th generation FloTrac algorithm to track cardiac output changes in patients receiving phenylephrine.

PubMed

Ji, Fuhai; Li, Jian; Fleming, Neal; Rose, David; Liu, Hong

2015-08-01

Phenylephrine is often used to treat intra-operative hypotension. Previous studies have shown that the FloTrac cardiac monitor may overestimate cardiac output (CO) changes following phenylephrine administration. A new algorithm (4th generation) has been developed to improve performance in this setting. We performed a prospective observational study to assess the effects of phenylephrine administration on CO values measured by the 3rd and 4th generation FloTrac algorithms. 54 patients were enrolled in this study. We used the Nexfin, a pulse contour method shown to be insensitive to vasopressor administration, as the reference method. Radial arterial pressures were recorded continuously in patients undergoing surgery. Phenylephrine administration times were documented. Arterial pressure recordings were subsequently analyzed offline using three different pulse contour analysis algorithms: FloTrac 3rd generation (G3), FloTrac 4th generation (G4), and Nexfin (nf). One minute of hemodynamic measurements was analyzed immediately before phenylephrine administration and then repeated when the mean arterial pressure peaked. A total of 157 (4.6 ± 3.2 per patient, range 1-15) paired sets of hemodynamic recordings were analyzed. Phenylephrine induced a significant increase in stroke volume (SV) and CO with the FloTrac G3, but not with FloTrac G4 or Nexfin algorithms. Agreement between FloTrac G3 and Nexfin was: 0.23 ± 1.19 l/min and concordance was 51.1%. In contrast, agreement between FloTrac G4 and Nexfin was: 0.19 ± 0.86 l/min and concordance was 87.2%. In conclusion, the pulse contour method of measuring CO, as implemented in FloTrac 4th generation algorithm, has significantly improved its ability to track the changes in CO induced by phenylephrine.

Ceramide Is Metabolized to Acylceramide and Stored in Lipid Droplets.

PubMed

Senkal, Can E; Salama, Mohamed F; Snider, Ashley J; Allopenna, Janet J; Rana, Nadia A; Koller, Antonius; Hannun, Yusuf A; Obeid, Lina M

2017-03-07

In an approach aimed at defining interacting partners of ceramide synthases (CerSs), we found that fatty acyl-CoA synthase ACSL5 interacts with all CerSs. We demonstrate that ACSL5-generated FA-CoA was utilized with de novo ceramide for the generation of acylceramides, poorly studied ceramide metabolites. Functionally, inhibition of ceramide channeling to acylceramide enhanced accumulation of de novo ceramide and resulted in augmentation of ceramide-mediated apoptosis. Mechanistically, we show that acylceramide generation is catalyzed by diacylglycerol acyltransferase 2 (DGAT2) on lipid droplets. In summary, this study identifies a metabolic pathway of acylceramide generation and its sequestration in LDs in cells and in livers of mice on a high-fat diet. The study also implicates this pathway in ceramide-mediated apoptosis, and has implications in co-regulation of triglyceride and sphingolipid metabolisms. Published by Elsevier Inc.

Dual comb generation from a mode-locked fiber laser with orthogonally polarized interlaced pulses.

PubMed

Akosman, Ahmet E; Sander, Michelle Y

2017-08-07

Ultra-high precision dual-comb spectroscopy traditionally requires two mode-locked, fully stabilized lasers with complex feedback electronics. We present a novel mode-locked operation regime in a thulium-holmium co-doped fiber laser, a frequency-halved state with orthogonally polarized interlaced pulses, for dual comb generation from a single source. In a linear fiber laser cavity, an ultrafast pulse train composed of co-generated, equal intensity and orthogonally polarized consecutive pulses at half of the fundamental repetition rate is demonstrated based on vector solitons. Upon optical interference of the orthogonally polarized pulse trains, two stable microwave RF beat combs are formed, effectively down-converting the optical properties into the microwave regime. These co-generated, dual polarization interlaced pulse trains, from one all-fiber laser configuration with common mode suppression, thus provide an attractive compact source for dual-comb spectroscopy, optical metrology and polarization entanglement measurements.

Inhibition of glycerophosphate-dependent H2O2 generation in brown fat mitochondria by idebenone.

PubMed

Rauchová, Hana; Vrbacký, Marek; Bergamini, Christian; Fato, Romana; Lenaz, Giorgio; Houstek, Josef; Drahota, Zdenek

2006-01-06

The established protective effect of coenzyme Q (CoQ) analogs is dependent on the location of reactive oxygen species (ROS) generation. One of these analogs--idebenone (hydroxydecyl-ubiquinone) is used as an antioxidative therapeutic drug. We tested its scavenging effect on the glycerophosphate (GP)-dependent ROS production as this enzyme was shown as a new site in the mitochondrial respiratory chain where ROS can be generated. We observed that idebenone inhibits both GP- and succinate-dependent ROS production. Idebenone and CoQ1 were found to be more efficient in the scavenging activity (IC50: 0.052 and 0.075 microM, respectively) than CoQ3 (IC50: 45.8 microM). Idebenone also inhibited ferricyanide (FeCN)-activated, GP-dependent ROS production. Our data thus extend previous findings on the scavenging effect of idebenone and show that it can also eliminate GP-dependent ROS generation.

Stress-induced rearrangement of Fusarium retrotransposon sequences.

PubMed

Anaya, N; Roncero, M I

1996-11-27

Rearrangement of fusarium oxysporum retrotransposon skippy was induced by growth in the presence of potassium chlorate. Three fungal strains, one sensitive to chlorate (Co60) and two resistant to chlorate and deficient for nitrate reductase (Co65 and Co94), were studied by Southern analysis of their genomic DNA. Polymorphism was detected in their hybridization banding pattern, relative to the wild type grown in the absence of chlorate, using various enzymes with or without restriction sites within the retrotransposon. Results were consistent with the assumption that three different events had occurred in strain Co60: genomic amplification of skippy yielding tandem arrays of the element, generation of new skippy sequences, and deletion of skippy sequences. Amplification of Co60 genomic DNA using the polymerase chain reaction and divergent primers derived from the retrotransposon generated a new band, corresponding to one long terminal repeat plus flanking sequences, that was not present in the wild-type strain. Molecular analysis of nitrate reductase-deficient mutants showed that generation and deletion of skippy sequences, but not genomic amplification in tandem repeats, had occurred in their genomes.

Conversion of CO2 to CO using radio-frequency atmospheric pressure plasmas

NASA Astrophysics Data System (ADS)

Foote, Alexander; Dedrick, James; O'Connell, Deborah; North, Michael; Gans, Timo

2016-09-01

Low temperature plasmas can be used for the in situ generation of CO, from relatively non-toxic CO2 . CO is very useful in many industrial chemical processes and so, via low temperature plasmas, CO2, a waste product, can be converted into a valuable chemical. The key challenges in using this method, for CO production, are optimising the energy efficiency, maximising the conversion of CO2 into CO and then separating the CO from the other species produced in the plasma. Very high yields of CO, greater than 90%, have been achieved at atmospheric pressure using argon as a carrier gas with admixtures up to 1.5% with energy efficiencies of up to 4%. The plasma generated in continuous and spatially homogeneous and is driven at a frequency of 40.68 MHz. A zero dimensional global model has also been used to simulate the chemical kinetics of the plasma to determine the dominant dissociation processes and is in good agreement with the experimentally determined yields. The model is used to determine how important a role the vibrational states of CO2 are, in a highly collisional plasma, to the production of CO and there can provide insight into how to improve the energy efficiency and suppress unwanted reactions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Romanov, V.N.; Ackman, T.E.; Soong, Yee

The looming global energy and environmental crises underscore a pressing need for the revision of current energy policies. The dominating albeit somewhat optimistic public perception is that hundreds of years worth of coal available for power generation will offset the decline of oil and gas reserves. Although use of coal accounts for half of U.S. electricity generation and for a quarter of world energy consumption, it has been perceived until recently as unwelcomed by environmentalists and legislators. For coal power generation to be properly considered, CO2 and other greenhouse gas (GHG) generation and deposition must be addressed to assuage globalmore » climate change concerns. Capturing and sequestering CO2 emissions is one of the principal modes of carbon management. Herein we will suggest a novel process that includes capturing GHG in abundant materials, which can be facilitated by controlled sequential heating and cooling of these solids. By taking advantage of the properties of waste materials generated during coal production and the exhaust heat generated by the power plants, such an approach permits the integration of the entire CO2 cycle, from generation to deposition. Coupling coal extraction/preparation with power generation facilities would improve the economics of “zero-emission” power plants due to the proximity of all the involved facilities.« less

Mineralogy and trace element geochemistry of the Co- and Cu-bearing sulfides from the Shilu Fe-Co-Cu ore district in Hainan Province of South China

NASA Astrophysics Data System (ADS)

Wang, Zhilin; Xu, Deru; Zhang, Zhaochong; Zou, Fenghui; Wang, Li; Yu, Liangliang; Hu, Mingyue

2015-12-01

Hosted within the metamorphosed, neritic siliciclastic rocks and sedimentary carbonates of the Proterozoic Shilu Group, the Shilu Fe-Co-Cu ore district in Hainan Province of South China comprises the upper Fe- and the lower Co-Cu ore layers. Combined with the field observation, the mineralogical and geochemical studies of sulfides using electron microprobe and laser ablation ICP-MS analyses recognized three types of Co-Cu ores. Type I is represented by massive ores and mainly comprises the first generation of pyrite (PyI) which occurred either as recrystallized, subhedral to euhedral microcrystal aggregates (PyIa) or as elongated, fine-grained euhedral grains (PyIb) with an orientated alignment parallel to S1 foliation. Type II is banded, disseminated and brecciated ores, and composed of the second generation of pyrite (PyII) which displays internal rhythmic growth zoning, the first generations of chalcopyrite (CcpI) and pyrrhotite (PoI), and associated Co-(Ni)-(As)-sulfide minerals. Type III occurring as veins or veinlets mainly consists of the third generation of pyrite (PyIII) and the second generations of chalcopyrite (CcpII) and pyrrhotite (PoII), of which PyIII appears as subhedral to euhedrall grains or as rims of composite pyrite. The moderate Co and As, and high Ni contents as well as the low Co/Ni ratios (∼2-5) in PyI indicate a sedimentary-metamorphic origin for Type I ores. The higher Co, Ni and As concentrations in PyIb relative to PyIa likely was related to an inhomogeneous deformation-metamorphism. The highest Co (av. 51,195 ppm) in PyII and Ni (av. 3374 ppm) in PoI most likely were linked to the preferred incorporation of Co into pyrite and Ni into pyrrhotite. Combined with the high Ag concentrations in CcpI (av. 266 ppm) and PyII (av. 13.32 ppm), the high Co/Ni ratios in PyII (av. 1241) suggest the derivation of Type II ores from a Co-Cu-Ni-Ag-rich hydrothermal fluid. Further, up to 9 wt.% Co concentrations in PyII show a temperature condition of 310-400 °C. In contrast, the depletion of trace elements in CcpII and PyIII, and the lower Co/Ni ratios (av. 46) in PyIII suggest a Co-poor but Cu-bearing hydrothermal fluid for origin of Type III ores. The complex texture and chemical composition of sulfides combined with previous work confirm a four-stage metallogenesis for the Shilu Co-Cu ores. From early to late, these include: (1) the ca. 1075-880 Ma deposition of the primary Co-Cu ore source beds which most likely were derived from submarine, metalliferous hydrothermal fluids, (2) the syn-structural metamorphism which led to Type I ores due to the South China Caledonian Orogeny, (3) the first stage of hydrothermalism which produced Type II ores and most likely was associated with Indosinian magmatism, and (4) the second stage of hydrothermalism which yielded Type III ores and likely was related to Yanshanian magmatism. The first stage of hydrothermalism was considered to be significant for the Co-Cu enrichment. The Shilu Co-Cu ores thus are better attributed to a BIF origin, but greatly reworked and enriched by late structural deformation and hydrothermal activities.

Interrogating heterobimetallic co-catalytic responses for the electrocatalytic reduction of CO2 using supramolecular assembly.

PubMed

Machan, Charles W; Kubiak, Clifford P

2016-10-12

The use of hydrogen-bonding interactions to direct the non-covalent assembly of a heterobimetallic supramolecular system with Re and Mn bipyridine-based electrocatalysts is reported. Under catalytic conditions, the formation of hydrogen bonds generates a catalyst system which passes ∼10% more current than the individual current responses of the respective Re and Mn complexes for the reduction of CO 2 to CO and H 2 O. Infrared spectroelectrochemical studies indicate that the Re and Mn metal centers interact during the reduction mechanism, even forming heterobimetallic bonds under reducing conditions in the absence of substrate. These findings demonstrate that non-covalent assembly is a powerful method for generating new co-catalyst systems with greater reactivity and efficiency for transformations of interest.

DFT and 3D-QSAR Studies of Anti-Cancer Agents m-(4-Morpholinoquinazolin-2-yl) Benzamide Derivatives for Novel Compounds Design

NASA Astrophysics Data System (ADS)

Zhao, Siqi; Zhang, Guanglong; Xia, Shuwei; Yu, Liangmin

2018-06-01

As a group of diversified frameworks, quinazolin derivatives displayed a broad field of biological functions, especially as anticancer. To investigate the quantitative structure-activity relationship, 3D-QSAR models were generated with 24 quinazolin scaffold molecules. The experimental and predicted pIC50 values for both training and test set compounds showed good correlation, which proved the robustness and reliability of the generated QSAR models. The most effective CoMFA and CoMSIA were obtained with correlation coefficient r 2 ncv of 1.00 (both) and leave-one-out coefficient q 2 of 0.61 and 0.59, respectively. The predictive abilities of CoMFA and CoMSIA were quite good with the predictive correlation coefficients ( r 2 pred ) of 0.97 and 0.91. In addition, the statistic results of CoMFA and CoMSIA were used to design new quinazolin molecules.

Primary coenzyme Q10 (CoQ 10) deficiencies and related nephropathies.

PubMed

Ozaltin, Fatih

2014-06-01

Oxidative phosphorylation (OXPHOS) is a metabolic pathway that uses energy released by the oxidation of nutrients to generate adenosine triphosphate (ATP). Coenzyme Q10 (CoQ10), also known as ubiquinone, plays an essential role in the human body not only by generating ATP in the mitochondrial respiratory chain but also by providing protection from reactive oxygen species (ROS) and functioning in the activation of many mitochondrial dehydrogenases and enzymes required in pyrimidine nucleoside biosynthesis. The presentations of primary CoQ10 deficiencies caused by genetic mutations are very heterogeneous. The phenotypes related to energy depletion or ROS production may depend on the content of CoQ10 in the cell, which is determined by the severity of the mutation. Primary CoQ10 deficiency is unique among mitochondrial disorders because early supplementation with CoQ10 can prevent the onset of neurological and renal manifestations. In this review I summarize primary CoQ10 deficiencies caused by various genetic abnormalities, emphasizing its nephropathic form.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berto, Tobias F.; Sanwald, Kai E.; Byers, J. Paige

Photocatalytic overall water splitting requires co-catalysts that efficiently promote the generation of H-2 but do not catalyze its reverse oxidation. We demonstrate that CO chemisorbed on metal co-catalysts (Rh, Pt, Pd) suppresses the back reaction while maintaining the rate of H-2 evolution. On Rh/GaN:ZnO, the highest H-2 production rates were obtained with 4-40 mbar of CO, the back reaction remaining suppressed below 7 mbar of O-2. The O-2 and H-2 evolution rates compete with CO oxidation and the back reaction. The rates of all reactions increased with increasing photon absorption. However, due to different dependencies on the rate of chargemore » carrier generation, the selectivities for O-2 and H-2 formation increased in comparison to CO oxidation and the back reaction with increasing photon flux and/or quantum efficiency. Under optimum conditions, the impact of CO to prevent the back reaction is identical to that of a Cr2O3 layer covering the active metal particle.« less

Middle East respiratory syndrome in children. Dental considerations.

PubMed

Al-Sehaibany, Fares S

2017-04-01

As of January 2016, 1,633 laboratory-confirmed cases of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection and 587 MERS-related deaths have been reported by the World Health Organization globally. Middle East Respiratory Syndrome Coronavirus  may occur sporadically in communities or may be transmitted within families or hospitals. The number of confirmed MERS-CoV cases among healthcare workers has been increasing. Middle East Respiratory Syndrome Coronavirus may also spread through aerosols generated during various dental treatments, resulting in transmission between patients and dentists. As MERS-CoV cases have also been reported among children, pediatric dentists are at risk of MERS-CoV infection. This review discusses MERS-CoV infection in children and healthcare workers, especially pediatric dentists, and considerations pertaining to pediatric dentistry. Although no cases of MERS-CoV transmission between a patient and a dentist have yet been reported, the risk of MERS-CoV transmission from an infected patient may be high due to the unique work environment of dentists (aerosol generation).

Terpyridine complexes of first row transition metals and electrochemical reduction of CO₂ to CO.

PubMed

Elgrishi, Noémie; Chambers, Matthew B; Artero, Vincent; Fontecave, Marc

2014-07-21

Homoleptic terpyridine complexes of first row transition metals are evaluated as catalysts for the electrocatalytic reduction of CO2. Ni and Co-based catalytic systems are shown to reduce CO2 to CO under the conditions tested. The Ni complex was found to exhibit selectivity for CO2 over proton reduction while the Co-based system generates mixtures of CO and H2 with CO : H2 ratios being tuneable through variation of the applied potential.

Substitute CT generation from a single ultra short time echo MRI sequence: preliminary study

NASA Astrophysics Data System (ADS)

Ghose, Soumya; Dowling, Jason A.; Rai, Robba; Liney, Gary P.

2017-04-01

In MR guided radiation therapy planning both MR and CT images for a patient are acquired and co-registered to obtain a tissue specific HU map. Generation of the HU map directly from the MRI would eliminate the CT acquisition and may improve radiation therapy planning. In this preliminary study of substitute CT (sCT) generation, two porcine leg phantoms were scanned using a 3D ultrashort echo time (PETRA) sequence and co-registered to corresponding CT images to build tissue specific regression models. The model was created from one co-registered CT-PETRA pair to generate the sCT for the other PETRA image. An expectation maximization based clustering was performed on the co-registered PETRA image to identify the soft tissues, dense bone and air class membership probabilities. A tissue specific non linear regression model was built from one registered CT-PETRA pair dataset to predict the sCT of the second PETRA image in a two-fold cross validation schema. A complete substitute CT is generated in 3 min. The mean absolute HU error for air was 0.3 HU, bone was 95 HU, fat was 30 HU and for muscle it was 10 HU. The mean surface reconstruction error for the bone was 1.3 mm. The PETRA sequence enabled a low mean absolute surface distance for the bone and a low HU error for other classes. The sCT generated from a single PETRA sequence shows promise for the generation of fast sCT for MRI based radiation therapy planning.

Differential retention and release of CO 2 and CH 4 in kerogen nanopores: Implications for gas extraction and carbon sequestration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ho, Tuan Anh; Wang, Yifeng; Xiong, Yongliang

Methane (CH 4) and carbon dioxide (CO 2), the two major components generated from kerogen maturation, are stored dominantly in nanometer-sized pores in shale matrix as (1) a compressed gas, (2) an adsorbed surface species and/or (3) a species dissolved in pore water (H 2O). In addition, supercritical CO 2 has been proposed as a fracturing fluid for simultaneous enhanced oil/gas recovery (EOR) and carbon sequestration. A mechanistic understanding of CH 4-CO 2-H 2O interactions in shale nanopores is critical for designing effective operational processes. Using molecular simulations, we show that kerogen preferentially retains CO 2 over CH 4 andmore » that the majority of CO 2 either generated during kerogen maturation or injected in EOR will remain trapped in the kerogen matrix. The trapped CO 2 may be released only if the reservoir pressure drops below the supercritical CO 2 pressure. When water is present in the kerogen matrix, it may block CH 4 release. Furthermore, the addition of CO 2 may enhance CH 4 release because CO 2 can diffuse through water and exchange for adsorbed methane in the kerogen nanopores.« less

A Co3O4-CDots-C3N4 three component electrocatalyst design concept for efficient and tunable CO2 reduction to syngas.

PubMed

Guo, Sijie; Zhao, Siqi; Wu, Xiuqin; Li, Hao; Zhou, Yunjie; Zhu, Cheng; Yang, Nianjun; Jiang, Xin; Gao, Jin; Bai, Liang; Liu, Yang; Lifshitz, Yeshayahu; Lee, Shuit-Tong; Kang, Zhenhui

2017-11-28

Syngas, a CO and H 2 mixture mostly generated from non-renewable fossil fuels, is an essential feedstock for production of liquid fuels. Electrochemical reduction of CO 2 and H + /H 2 O is an alternative renewable route to produce syngas. Here we introduce the concept of coupling a hydrogen evolution reaction (HER) catalyst with a CDots/C 3 N 4 composite (a CO 2 reduction catalyst) to achieve a cheap, stable, selective and efficient route for tunable syngas production. Co 3 O 4 , MoS 2 , Au and Pt serve as the HER component. The Co 3 O 4 -CDots-C 3 N 4 electrocatalyst is found to be the most efficient among the combinations studied. The H 2 /CO ratio of the produced syngas is tunable from 0.07:1 to 4:1 by controlling the potential. This catalyst is highly stable for syngas generation (over 100 h) with no other products besides CO and H 2 . Insight into the mechanisms balancing between CO 2 reduction and H 2 evolution when applying the HER-CDots-C 3 N 4 catalyst concept is provided.

A spongy nickel-organic CO 2 reduction photocatalyst for nearly 100% selective CO production

DOE PAGES

Niu, Kaiyang; Xu, You; Wang, Haicheng; ...

2017-07-28

Solar-driven photocatalytic conversion of CO 2 into fuels has attracted a lot of interest; however, developing active catalysts that can selectively convert CO 2 to fuels with desirable reaction products remains a grand challenge. For instance, complete suppression of the competing H 2 evolution during photocatalytic CO 2-to-CO conversion has not been achieved before. We design and synthesize a spongy nickel-organic heterogeneous photocatalyst via a photochemical route. The catalyst has a crystalline network architecture with a high concentration of defects. It is highly active in converting CO 2 to CO, with a production rate of ~1.6 × 10 4 μmolmore » hour –1 g –1. No measurable H 2 is generated during the reaction, leading to nearly 100% selective CO production over H 2 evolution. When the spongy Ni-organic catalyst is enriched with Rh or Ag nanocrystals, the controlled photocatalytic CO 2 reduction reactions generate formic acid and acetic acid. As a result, achieving such a spongy nickel-organic photocatalyst is a critical step toward practical production of high-value multicarbon fuels using solar energy.« less

Garage carbon monoxide levels from sources commonly used in intentional poisoning.

PubMed

Hampson, Neil B; Holm, James R; Courtney, Todd G

2017-01-01

The incidence of intentional carbon monoxide (CO) poisoning is believed to have declined due to strict federal CO emissions standards for motor vehicles and the uniform application of catalytic converters (CC). We sought to compare ambient CO levels produced by automobiles with and without catalytic converters in a residential garage, as well as from other CO sources commonly used for intentional poisoning. CO levels were measured inside a freestanding 73 m3 one-car garage. CO sources included a 1971 automobile without CC, 2003 automobile with CC, charcoal grill, electrical generator, lawn mower and leaf blower. After 20 minutes of operation, the CO level in the garage was 253 PPM for the car without a catalytic converter and 30 PPM for the car equipped withone. CO levels after operating or burning the other sources were: charcoal 200 PPM; generator >999 PPM; lawn mower 198 PPM; and leaf blower 580 PPM. While emissions controls on automobiles have reduced intentional CO poisonings, alternate sources may produce CO at levels of the same magnitude as vehicles manufactured prior to the use of catalytic converters. Those involved in the care of potentially suicidal individuals should be aware of this.

A spongy nickel-organic CO 2 reduction photocatalyst for nearly 100% selective CO production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Niu, Kaiyang; Xu, You; Wang, Haicheng

Solar-driven photocatalytic conversion of CO 2 into fuels has attracted a lot of interest; however, developing active catalysts that can selectively convert CO 2 to fuels with desirable reaction products remains a grand challenge. For instance, complete suppression of the competing H 2 evolution during photocatalytic CO 2-to-CO conversion has not been achieved before. We design and synthesize a spongy nickel-organic heterogeneous photocatalyst via a photochemical route. The catalyst has a crystalline network architecture with a high concentration of defects. It is highly active in converting CO 2 to CO, with a production rate of ~1.6 × 10 4 μmolmore » hour –1 g –1. No measurable H 2 is generated during the reaction, leading to nearly 100% selective CO production over H 2 evolution. When the spongy Ni-organic catalyst is enriched with Rh or Ag nanocrystals, the controlled photocatalytic CO 2 reduction reactions generate formic acid and acetic acid. As a result, achieving such a spongy nickel-organic photocatalyst is a critical step toward practical production of high-value multicarbon fuels using solar energy.« less

Recycling of spent lithium-ion battery with polyvinyl chloride by mechanochemical process.

PubMed

Wang, Meng-Meng; Zhang, Cong-Cong; Zhang, Fu-Shen

2017-09-01

In the present study, cathode materials (C/LiCoO 2 ) of spent lithium-ion batteries (LIBs) and waste polyvinyl chloride (PVC) were co-processed via an innovative mechanochemical method, i.e. LiCoO 2 /PVC/Fe was co-grinded followed by water-leaching. This procedure generated recoverable LiCl from Li by the dechlorination of PVC and also generated magnetic CoFe 4 O 6 from Co. The effects of different additives (e.g. alkali metals, non-metal oxides, and zero-valent metals) on (i) the conversion rates of Li and Co and (ii) the dechlorination rate of PVC were investigated, and the reaction mechanisms were explored. It was found that the chlorine atoms in PVC were mechanochemically transformed into chloride ions that bound to the Li in LiCoO 2 to form LiCl. This resulted in reorganization of the Co and Fe crystals to form the magnetic material CoFe 4 O 6 . This study provides a more environmentally-friendly, economical, and straightforward approach for the recycling of spent LIBs and waste PVC compared to traditional processes. Copyright © 2017. Published by Elsevier Ltd.

Differential retention and release of CO 2 and CH 4 in kerogen nanopores: Implications for gas extraction and carbon sequestration

DOE PAGES

Ho, Tuan Anh; Wang, Yifeng; Xiong, Yongliang; ...

2018-02-06

Methane (CH 4) and carbon dioxide (CO 2), the two major components generated from kerogen maturation, are stored dominantly in nanometer-sized pores in shale matrix as (1) a compressed gas, (2) an adsorbed surface species and/or (3) a species dissolved in pore water (H 2O). In addition, supercritical CO 2 has been proposed as a fracturing fluid for simultaneous enhanced oil/gas recovery (EOR) and carbon sequestration. A mechanistic understanding of CH 4-CO 2-H 2O interactions in shale nanopores is critical for designing effective operational processes. Using molecular simulations, we show that kerogen preferentially retains CO 2 over CH 4 andmore » that the majority of CO 2 either generated during kerogen maturation or injected in EOR will remain trapped in the kerogen matrix. The trapped CO 2 may be released only if the reservoir pressure drops below the supercritical CO 2 pressure. When water is present in the kerogen matrix, it may block CH 4 release. Furthermore, the addition of CO 2 may enhance CH 4 release because CO 2 can diffuse through water and exchange for adsorbed methane in the kerogen nanopores.« less

Study of CO2 recovery in a carbonate fuel cell tri-generation plant

NASA Astrophysics Data System (ADS)

Rinaldi, Giorgio; McLarty, Dustin; Brouwer, Jack; Lanzini, Andrea; Santarelli, Massimo

2015-06-01

The possibility of separating and recovering CO2 in a biogas plant that co-produces electricity, hydrogen, and heat is investigated. Exploiting the ability of a molten carbonate fuel cell (MCFC) to concentrate CO2 in the anode exhaust stream reduces the energy consumption and complexity of CO2 separation techniques that would otherwise be required to remove dilute CO2 from combustion exhaust streams. Three potential CO2 concentrating configurations are numerically simulated to evaluate potential CO2 recovery rates: 1) anode oxidation and partial CO2 recirculation, 2) integration with exhaust from an internal combustion engine, and 3) series connection of molten carbonate cathodes initially fed with internal combustion engine (ICE) exhaust. Physical models have been calibrated with data acquired from an operating MCFC tri-generating plant. Results illustrate a high compatibility between hydrogen co-production and CO2 recovery with series connection of molten carbonate systems offering the best results for efficient CO2 recovery. In this case the carbon capture ratio (CCR) exceeds 73% for two systems in series and 90% for 3 MCFC in series. This remarkably high carbon recovery is possible with 1.4 MWe delivered by the ICE system and 0.9 MWe and about 350 kg day-1 of H2 delivered by the three MCFC.

Co thickness dependence of structural and magnetic properties in spin quantum cross devices utilizing stray magnetic fields

NASA Astrophysics Data System (ADS)

Kaiju, H.; Kasa, H.; Komine, T.; Mori, S.; Misawa, T.; Abe, T.; Nishii, J.

2015-05-01

We investigate the Co thickness dependence of the structural and magnetic properties of Co thin-film electrodes sandwiched between borate glasses in spin quantum cross (SQC) devices that utilize stray magnetic fields. We also calculate the Co thickness dependence of the stray field between the two edges of Co thin-film electrodes in SQC devices using micromagnetic simulation. The surface roughness of Co thin films with a thickness of less than 20 nm on borate glasses is shown to be as small as 0.18 nm, at the same scanning scale as the Co film thickness, and the squareness of the hysteresis loop is shown to be as large as 0.96-1.0. As a result of the establishment of polishing techniques for Co thin-film electrodes sandwiched between borate glasses, we successfully demonstrate the formation of smooth Co edges and the generation of stray magnetic fields from Co edges. Theoretical calculation reveals that a strong stray field beyond 6 kOe is generated when the Co thickness is greater than 10 nm at a junction gap distance of 5 nm. From these experimental and calculation results, it can be concluded that SQC devices with a Co thickness of 10-20 nm can be expected to function as spin-filter devices.

Heat recovery from sorbent-based CO.sub.2 capture

DOEpatents

Jamal, Aqil; Gupta, Raghubir P

2015-03-10

The present invention provides a method of increasing the efficiency of exothermic CO.sub.2 capture processes. The method relates to withdrawing heat generated during the exothermic capture of CO.sub.2 with various sorbents via heat exchange with a working fluid. The working fluid is provided at a temperature and pressure such that it is in the liquid state, and has a vaporization temperature in a range such that the heat arising from the reaction of the CO.sub.2 and the sorbent causes a phase change from liquid to vapor state in whole or in part and transfers heat from to the working fluid. The resulting heated working fluid may subsequently be used to generate power.

Multiline CO2 laser with Q-switching for generation of terahertz radiation

NASA Astrophysics Data System (ADS)

Ionin, A. A.; Kinyaevskiy, I. O.; Klimachev, Yu M.; Stepanishchev, V. V.; Khafizov, I. Zh

2017-12-01

In this paper we consider the method of obtaining THz radiation by difference frequency generation (DFG) of multiline CO2 laser. For this purpose a multiline CO2 laser with Q-switching was created. The three strongest lines, 9 R(18), 9 P(20) and 9 P(22) with wavelengths ∼9.28, ∼9.55 and ∼9.57 μm respectively, held 85% of CO2 laser power, and can be used to obtain difference frequency at a wavelength of ∼310 μm. DFG of other spectral lines fall within the range of 263 ÷ 8100 μm. Different nonlinear crystals for DFG and filters to separate THz radiation were considered.

Electro-autotrophic synthesis of higher alcohols

DOEpatents

Liao, James C.; Cho, Kwang Myung

2016-11-01

The disclosure provides a process that converts CO.sub.2 to higher alcohols (e.g. isobutanol) using electricity as the energy source. This process stores electricity (e.g. from solar energy, nuclear energy, and the like) in liquid fuels that can be used as high octane number gasoline substitutes. Instead of deriving reducing power from photosynthesis, this process derives reducing power from electrically generated mediators, either H.sub.2 or formate. H.sub.2 can be derived from electrolysis of water. Formate can be generated by electrochemical reduction of CO.sub.2. After delivering the reducing power in the cell, formate becomes CO.sub.2 and recycles back. Therefore, the biological CO.sub.2 fixation process can occur in the dark.

Electro-autotrophic synthesis of higher alcohols

DOEpatents

Liao, James C.; Cho, Kwang Myung

2015-10-06

The disclosure provides a process that converts CO.sub.2 to higher alcohols (e.g. isobutanol) using electricity as the energy source. This process stores electricity (e.g. from solar energy, nuclear energy, and the like) in liquid fuels that can be used as high octane number gasoline substitutes. Instead of deriving reducing power from photosynthesis, this process derives reducing power from electrically generated mediators, either H.sub.2 or formate. H.sub.2 can be derived from electrolysis of water. Formate can be generated by electrochemical reduction of CO.sub.2. After delivering the reducing power in the cell, formate becomes CO.sub.2 and recycles back. Therefore, the biological CO.sub.2 fixation process can occur in the dark.

The O2-assisted Al/CO2 electrochemical cell: A system for CO2 capture/conversion and electric power generation.

PubMed

Al Sadat, Wajdi I; Archer, Lynden A

2016-07-01

Economical and efficient carbon capture, utilization, and sequestration technologies are a requirement for successful implementation of global action plans to reduce carbon emissions and to mitigate climate change. These technologies are also essential for longer-term use of fossil fuels while reducing the associated carbon footprint. We demonstrate an O2-assisted Al/CO2 electrochemical cell as a new approach to sequester CO2 emissions and, at the same time, to generate substantial amounts of electrical energy. We report on the fundamental principles that guide operations of these cells using multiple intrusive electrochemical and physical analytical methods, including chronopotentiometry, cyclic voltammetry, direct analysis in real-time mass spectrometry, energy-dispersive x-ray spectroscopy, x-ray photoelectron spectroscopy, and coupled thermogravimetric analysis-Fourier transform infrared spectroscopy. On this basis, we demonstrate that an electrochemical cell that uses metallic aluminum as anode and a carbon dioxide/oxygen gas mixture as the active material in the cathode provides a path toward electrochemical generation of a valuable (C2) species and electrical energy. Specifically, we show that the cell first reduces O2 at the cathode to form superoxide intermediates. Chemical reaction of the superoxide with CO2 sequesters the CO2 in the form of aluminum oxalate, Al2(C2O4)3, as the dominant product. On the basis of an analysis of the overall CO2 footprint, which considers emissions associated with the production of the aluminum anode and the CO2 captured/abated by the Al/CO2-O2 electrochemical cell, we conclude that the proposed process offers an important strategy for net reduction of CO2 emissions.

The O2-assisted Al/CO2 electrochemical cell: A system for CO2 capture/conversion and electric power generation

PubMed Central

Al Sadat, Wajdi I.; Archer, Lynden A.

2016-01-01

Economical and efficient carbon capture, utilization, and sequestration technologies are a requirement for successful implementation of global action plans to reduce carbon emissions and to mitigate climate change. These technologies are also essential for longer-term use of fossil fuels while reducing the associated carbon footprint. We demonstrate an O2-assisted Al/CO2 electrochemical cell as a new approach to sequester CO2 emissions and, at the same time, to generate substantial amounts of electrical energy. We report on the fundamental principles that guide operations of these cells using multiple intrusive electrochemical and physical analytical methods, including chronopotentiometry, cyclic voltammetry, direct analysis in real-time mass spectrometry, energy-dispersive x-ray spectroscopy, x-ray photoelectron spectroscopy, and coupled thermogravimetric analysis–Fourier transform infrared spectroscopy. On this basis, we demonstrate that an electrochemical cell that uses metallic aluminum as anode and a carbon dioxide/oxygen gas mixture as the active material in the cathode provides a path toward electrochemical generation of a valuable (C2) species and electrical energy. Specifically, we show that the cell first reduces O2 at the cathode to form superoxide intermediates. Chemical reaction of the superoxide with CO2 sequesters the CO2 in the form of aluminum oxalate, Al2(C2O4)3, as the dominant product. On the basis of an analysis of the overall CO2 footprint, which considers emissions associated with the production of the aluminum anode and the CO2 captured/abated by the Al/CO2-O2 electrochemical cell, we conclude that the proposed process offers an important strategy for net reduction of CO2 emissions. PMID:27453949

Persistence of Positive Carryover Effects in the Oyster, Saccostrea glomerata, following Transgenerational Exposure to Ocean Acidification.

PubMed

Parker, Laura M; O'Connor, Wayne A; Raftos, David A; Pörtner, Hans-Otto; Ross, Pauline M

2015-01-01

Ocean acidification (OA) is predicted to have widespread implications for marine organisms, yet the capacity for species to acclimate or adapt over this century remains unknown. Recent transgenerational studies have shown that for some marine species, exposure of adults to OA can facilitate positive carryover effects to their larval and juvenile offspring that help them to survive in acidifying oceanic conditions. But whether these positive carryover effects can persist into adulthood or the next generation is unknown. Here we tested whether positive carryover effects found in larvae of the oyster, Saccostrea glomerata following transgenerational exposure to elevated CO2, could persist into adulthood and whether subsequent transgenerational exposure of adults to elevated CO2 would facilitate similar adaptive responses in the next generation of larvae and juveniles. Following our previous transgenerational exposure of parental adults and first generation (F1) larvae to ambient (385 μatm) and elevated (856 μatm) CO2, newly settled F1 juveniles were transferred to the field at ambient CO2 for 14 months, until they reached reproductive maturity. At this time, the F1 adults were returned to the laboratory and the previous transgenerational CO2 exposure was repeated to produce F2 offspring. We found that the capacity of adults to regulate extracellular pH at elevated CO2 was improved if they had a prior history of transgenerational exposure to elevated CO2. In addition, subsequent transgenerational exposure of these adults led to an increase in the resilience of their larval and juvenile offspring. Offspring with a history of transgenerational exposure to elevated CO2 had a lower percentage abnormality, faster development rate, faster shell growth and increased heart rate at elevated CO2 compared with F2 offspring with no prior history of exposure to elevated CO2. Our results suggest that positive carryover effects originating during parental and larval exposure will be important in mediating some of the impacts of OA for later life-history stages and generations.

Electrode Modification and Optimization in Air-Cathode Single-Chamber Microbial Fuel Cells.

PubMed

Wang, Yanhua; Wu, Jiayan; Yang, Shengke; Li, Huihui; Li, Xiaoping

2018-06-27

Due to the known problems of microbial fuel cells (MFCs), such as low electricity generation performance and high cost of operation, we modified the electrode with graphene and polyaniline (PANI) is a single-chamber air-cathode MFC and then evaluated the effects of electrode modification on MFC electricity generation performance. Carbon cloth electrodes (unmodified, CC; graphene-modified, G/CC; and polyaniline-graphene-modified, PANI-G/CC) were prepared using the impregnation method. Sulfonated cobalt phthalocyanine (CoPcS) was then introduced as a cathode catalyst. The Co-PANI-G/CC cathode showed higher catalytic activity toward oxygen reduction compared with other electrodes. The maximum power density of the MFC with Co-PANI-G/CC cathode was 32.2 mW/m², which was 1.8 and 6.1 times higher than the value obtained with Co-G/CC and Co/CC cathodes, respectively. This indicates a significant improvement in the electricity generation of single-chamber MFCs and provides a simple, effective cathode modification method. Furthermore, we constructed single-chamber MFCs using the modified anode and cathode and analyzed electricity generation and oxytetracycline (OTC) degradation with different concentrations of OTC as the fuel. With increasing added OTC concentration, the MFC performance in both electricity generation and OTC degradation gradually decreased. However, when less than 50 mg/L OTC was added, the 5-day degradation rate of OTC reached more than 90%. It is thus feasible to process OTC-containing wastewater and produce electricity using single-chamber MFCs, which provides a new concept for wastewater treatment.

Comparison of life cycle carbon dioxide emissions and embodied energy in four renewable electricity generation technologies in New Zealand.

PubMed

Rule, Bridget M; Worth, Zeb J; Boyle, Carol A

2009-08-15

In order to make the best choice between renewable energy technologies, it is important to be able to compare these technologies on the basis of their sustainability, which may include a variety of social, environmental, and economic indicators. This study examined the comparative sustainability of four renewable electricity technologies in terms of their life cycle CO2 emissions and embodied energy, from construction to decommissioning and including maintenance (periodic component replacement plus machinery use), using life cycle analysis. The models developed were based on case studies of power plants in New Zealand, comprising geothermal, large-scale hydroelectric, tidal (a proposed scheme), and wind-farm electricity generation. The comparative results showed that tidal power generation was associated with 1.8 g of CO2/kWh, wind with 3.0 g of CO2/kWh, hydroelectric with 4.6 g of CO2/kWh, and geothermal with 5.6 g of CO2/kWh (not including fugitive emissions), and that tidal power generation was associated with 42.3 kJ/kWh, wind with 70.2 kJ/kWh, hydroelectric with 55.0 kJ/kWh, and geothermal with 94.6 kJ/kWh. Other environmental indicators, as well as social and economic indicators, should be applied to gain a complete picture of the technologies studied.

The impacts of meeting a tight CO2 performance standard on the electric power sector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hanson, Donald; Schmalzer, David; Nichols, Christopher

This paper presents innovative modeling of complex interactions among gas-fired generators, coal-fired power plants, and renewables (wind and solar) when pushed hard to reduce CO2 emissions. A hypothetical CO2 technology performance standard, giving rise to a shadow price on CO2 emissions, was specified as part of the study design. In this work we see gas generation rapidly replacing coal generation. To understand the fate of coal based generation, it is important to examine trends at a granular level. An important feature of our model, the Electricity Supply and Investment Model (ESIM) is that it contains a unit inventory with unitmore » characteristics and a memory of how each unit is operated over time. Cycling damages that individual coal units incur are a function of cumulative wear and tear over time. The expected remaining life of a cycled coal unit will depend on the severity of the cycling and for how many years. Deteriorating operating characteristics of a cycled unit over time results in higher operating costs, slipping down the dispatch loading order, and hence an acceleration of cycling damage, that is, a viscous circle of decline. The rate of CFPP retirements will increase for lower gas prices, higher price on CO2 emissions, and greater penetration of variable and intermittent renewables. Published by Elsevier B.V.« less

Submarine Periscope Depth Course Selection Tactical Decision Aid

DTIC Science & Technology

1997-12-01

are translated to Cartesian coordinates. Co is own ship’s course. 8 X0 = DMho. cos(Co) Yo = DAho . sin(Co) Xc = DMht- cos(Ct) Yc = DMhbt sin(Ct) These...Display Graph. The input parameters of DAho , Ct, and DMiht along with Co as generated by the simulation are used to determine the Cartesian

Graphene-Immobilized fac-Re(bipy)(CO)3Cl for Syngas Generation from Carbon Dioxide.

PubMed

Zhou, Xin; Micheroni, Daniel; Lin, Zekai; Poon, Christopher; Li, Zhong; Lin, Wenbin

2016-02-17

We report the synthesis of fac-M(4-amino-bipy)(CO)3X (M = Mn and X = Br or M = Re and X = Cl, with bipy = 2,2'-bipyridine), their immobilization on graphene oxide (GrO) via diazonium grafting, and the use of Re-functionalized GrO for electrocatalytic syngas production. Infrared (IR) spectroscopy, X-ray absorption fine structure (XAFS) spectroscopy, and electrocatalysis indicated successful grafting of the Re catalyst onto GrO. Re-functionalized GrO was then deposited onto a glassy carbon electrode (GCE) for CO2 reduction. Investigation of the Re-functionalized GCE for syngas production was performed in a CO2-saturated acetonitrile solution with 3.1 M H2O as the proton source and 0.1 M tetrabutylammonium hexafluorophosphate (TBAPF6) as the supporting electrolyte. Cyclic voltammetry (CV), controlled potential electrolysis (CPE), and gas chromatography (GC) were employed to determine its CO2-to-CO conversion performance. The Re catalyst shows a turnover frequency (TOF) for generating CO up to 4.44 s(-1) with a CO/H2 ratio of 7:5.

Co3O4 nanowires as efficient catalyst precursor for hydrogen generation from sodium borohydride hydrolysis

NASA Astrophysics Data System (ADS)

Wei, Lei; Cao, Xurong; Ma, Maixia; Lu, Yanhong; Wang, Dongsheng; Zhang, Suling; Wang, Qian

Hydrogen generation from the catalytic hydrolysis of sodium borohydride has many advantages, and therefore, significant research has been undertaken on the development of highly efficient catalysts for this purpose. In our present work, Co3O4 nanowires were successfully synthesized as catalyst precursor by employing SBA-15 as a hard template. For material characterization, high-resolution transmission electron microscopy (HRTEM), powder X-ray diffraction (XRD), fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and N2 adsorption isotherms were employed, respectively. To measure the catalyst activity, typical water-displacement method was carried out. Using a reaction solution comprising 10wt.% NaBH4 and 2wt.% NaOH, the hydrogen generation rate (HGR) was observed to be as high as 7.74L min-1 g-1 at 25∘C in the presence of Co3O4 nanowires, which is significantly higher than that of CoB nanoparticles and commercial Co3O4 powder. Apparent activation energy was calculated to be 50.9kJ mol-1. After recycling the Co3O4 nanowires six times, HGR was decreased to be 72.6% of the initial level.

(Text) Mining the LANDscape: Themes and Trends over 40 years of Landscape and Urban Planning

Treesearch

Paul H. Gobster

2014-01-01

In commemoration of the journal's 40th anniversary, the co-editor explores themes and trends covered by Landscape and Urban Planning and its parent journals through a qualitative comparison of co-occurrence term maps generated from the text corpora of its abstracts across the four decadal periods of publication.Cluster maps generated from the...

System for the co-production of electricity and hydrogen

DOEpatents

Pham, Ai Quoc; Anderson, Brian Lee

2007-10-02

Described herein is a system for the co-generation of hydrogen gas and electricity, wherein the proportion of hydrogen to electricity can be adjusted from 0% to 100%. The system integrates fuel cell technology for power generation with fuel-assisted steam-electrolysis. A hydrocarbon fuel, a reformed hydrocarbon fuel, or a partially reformed hydrocarbon fuel can be fed into the system.

The effect of feed composition on anaerobic co-digestion of animal-processing by-products.

PubMed

Hidalgo, D; Martín-Marroquín, J M; Corona, F

2018-06-15

Four streams and their mixtures have been considered for anaerobic co-digestion, all of them generated during pig carcasses processing or in related industrial activities: meat flour (MF), process water (PW), pig manure (PM) and glycerin (GL). Biochemical methane potential assays were conducted at 37 °C to evaluate the effects of the substrate mix ratio on methane generation and process behavior. The results show that the co-digestion of these products favors the anaerobic fermentation process when limiting the amount of meat flour in the mixture to co-digest, which should not exceed 10%. The ratio of other tested substrates is less critical, because different mixtures reach similar values of methane generation. The presence in the mixture of process water contributes to a quick start of the digester, something very interesting when operating an industrial reactor. The analysis of the fraction digested reveals that the four analyzed streams can be, a priori, suitable for agronomic valorization once digested. Copyright © 2017. Published by Elsevier Ltd.

Reduction of Bromate by Cobalt-Impregnated Biochar Fabricated via Pyrolysis of Lignin Using CO2 as a Reaction Medium.

PubMed

Cho, Dong-Wan; Kwon, Gihoon; Ok, Yong Sik; Kwon, Eilhann E; Song, Hocheol

2017-04-19

In this study, pyrolysis of lignin impregnated with cobalt (Co) was conducted to fabricate a Co-biochar (i.e., Co/lignin biochar) for use as a catalyst for bromate (BrO 3 - ) reduction. Carbon dioxide (CO 2 ) was employed as a reaction medium in the pyrolysis to induce desired effects associated with CO 2 ; (1) the enhanced thermal cracking of volatile organic compounds (VOCs) evolved from the thermal degradation of biomass, and (2) the direct reaction between CO 2 and VOCs, which resulted in the enhanced generation of syngas (i.e., H 2 and CO). This study placed main emphases on three parts: (1) the role of impregnated Co in pyrolysis of lignin in the presence of CO 2 , (2) the characterization of Co/lignin biochar, and (3) evaluation of catalytic capability of Co-lignin biochar in BrO 3 - reduction. The findings from the pyrolysis experiments strongly evidenced that the desired CO 2 effects were strengthened due to catalytic effect of impregnated Co in lignin. For example, the enhanced generation of syngas from pyrolysis of Coimpregnated lignin in CO 2 was more significant than the case without Co impregnation. Moreover, pyrolysis of Coimpregnated lignin in CO 2 led to production of biochar of which surface area (599 m 2 g -1 ) is nearly 100 times greater than the biochar produced in N 2 (6.6 m 2 g -1 ). Co/lignin biochar produced in CO 2 also showed a great performance in catalyzing BrO 3 - reduction as compared to the biochar produced in N 2 .

Detailed study of spontaneous rotation generation in diverted H-mode plasma using the full-f gyrokinetic code XGC1

NASA Astrophysics Data System (ADS)

Seo, Janghoon; Chang, C. S.; Ku, S.; Kwon, J. M.; Yoon, E. S.

2013-10-01

The Full-f gyrokinetic code XGC1 is used to study the details of toroidal momentum generation in H-mode plasma. Diverted DIII-D geometry is used, with Monte Carlo neutral particles that are recycled at the limiter wall. Nonlinear Coulomb collisions conserve particle, momentum, and energy. Gyrokinetic ions and adiabatic electrons are used in the present simulation to include the effects from ion gyrokinetic turbulence and neoclassical physics, under self-consistent radial electric field generation. Ion orbit loss physics is automatically included. Simulations show a strong co-Ip flow in the H-mode layer at outside midplane, similarly to the experimental observation from DIII-D and ASDEX-U. The co-Ip flow in the edge propagates inward into core. It is found that the strong co-Ip flow generation is mostly from neoclassical physics. On the other hand, the inward momentum transport is from turbulence physics, consistently with the theory of residual stress from symmetry breaking. Therefore, interaction between the neoclassical and turbulence physics is a key factor in the spontaneous momentum generation.

Design of experimental system for supercritical CO2 fracturing under confining pressure conditions

NASA Astrophysics Data System (ADS)

Wang, H.; Lu, Q.; Li, X.; Yang, B.; Zheng, Y.; Shi, L.; Shi, X.

2018-03-01

Supercritical CO2 has the characteristics of low viscosity, high diffusion and zero surface tension, and it is considered as a new fluid for non-polluting and non-aqueous fracturing which can be used for shale gas development. Fracturing refers to a method of utilizing the high-pressure fluid to generate fractures in the rock formation so as to improve the oil and gas flow conditions and increase the oil and gas production. In this article, a new type of experimental system for supercritical CO2 fracturing under confining pressure conditions is designed, which is based on characteristics of supercritical CO2, shale reservoir and down-hole environment. The experimental system consists of three sub-systems, including supercritical CO2 generation system, supercritical CO2 fracturing system and data analysis system. It can be used to simulate supercritical CO2 fracturing under geo-stress conditions, thus to study the rock initiation pressure, the formation of the rock fractures, fractured surface morphology and so on. The experimental system has successfully carried out a series of supercritical CO2 fracturing experiments. The experimental results confirm the feasibility of the experimental system and the high efficiency of supercritical CO2 in fracturing tight rocks.

Electricity without carbon dioxide: Assessing the role of carbon capture and sequestration in United States electric markets

NASA Astrophysics Data System (ADS)

Johnson, Timothy Lawrence

2002-09-01

Stabilization of atmospheric greenhouse gas concentrations will likely require significant cuts in electric sector carbon dioxide (CO2) emissions. The ability to capture and sequester CO2 in a manner compatible with today's fossil-fuel based power generating infrastructure offers a potentially low-cost contribution to a larger climate change mitigation strategy. This thesis fills a niche between economy-wide studies of CO 2 abatement and plant-level control technology assessments by examining the contribution that carbon capture and sequestration (CCS) might make toward reducing US electric sector CO2 emissions. The assessment's thirty year perspective ensures that costs sunk in current infrastructure remain relevant and allows time for technological diffusion, but remains free of assumptions about the emergence of unidentified radical innovations. The extent to which CCS might lower CO2 mitigation costs will vary directly with the dispatch of carbon capture plants in actual power-generating systems, and will depend on both the retirement of vintage capacity and competition from abatement alternatives such as coal-to-gas fuel switching and renewable energy sources. This thesis therefore adopts a capacity planning and dispatch model to examine how the current distribution of generating units, natural gas prices, and other industry trends affect the cost of CO2 control via CCS in an actual US electric market. The analysis finds that plants with CO2 capture consistently provide significant reductions in base-load emissions at carbon prices near 100 $/tC, but do not offer an economical means of meeting peak demand unless CO2 reductions in excess of 80 percent are required. Various scenarios estimate the amount by which turn-over of the existing generating infrastructure and the severity of criteria pollutant constraints reduce mitigation costs. A look at CO2 sequestration in the seabed beneath the US Outer Continental Shelf (OCS) complements this model-driven assessment by considering issues of risk, geological storage capacity, and regulation. Extensive experience with offshore oil and gas operations suggests that the technical uncertainties associated with OCS sequestration are not large. The legality of seabed CO 2 disposal under US law and international environmental agreements, however, is ambiguous, and the OCS may be the first region where these regulatory regimes clash over CO2 sequestration.

Air quality co-benefits and costs under state, regional, or national cooperation to regulate CO2 from existing power plants

NASA Astrophysics Data System (ADS)

Saari, R.; Selin, N. E.

2015-12-01

We examine the effect of state, regional, and national cooperation on the costs and air quality co-benefits of a policy to limit the carbon intensity of existing electricity generation. Electricity generation is a significant source of both greenhouse gases and air pollutant emissions that harm human health. Previous studies have shown that air quality co-benefits can be substantial compared to the costs of limiting carbon emissions in the energy system. The EPA's proposed Clean Power Plan seeks to impose carbon intensity limits for each state, but allows states to cooperate in order to meet combined limits. We explore how such cooperation might produce trade-offs between lower costs, widespread pollution reductions, and local reductions. We employ a new state-level model of the US energy system and economy to examine the costs and emissions as states reduce demand or deploy cleaner generation. We use an advanced air quality impacts modeling system, including SMOKE, CAMx, and BenMAP, to estimate health-related air quality co-benefits and compare these to costs under different levels of cooperation. We draw conclusions about the potential impacts of cooperation on economic welfare at various scales.

BESTIA - the next generation ultra-fast CO 2 laser for advanced accelerator research

DOE PAGES

Pogorelsky, Igor V.; Babzien, Markus; Ben-Zvi, Ilan; ...

2015-12-02

Over the last two decades, BNL’s ATF has pioneered the use of high-peak power CO 2 lasers for research in advanced accelerators and radiation sources. In addition, our recent developments in ion acceleration, Compton scattering, and IFELs have further underscored the benefits from expanding the landscape of strong-field laser interactions deeper into the mid-infrared (MIR) range of wavelengths. This extension validates our ongoing efforts in advancing CO 2 laser technology, which we report here. Our next-generation, multi-terawatt, femtosecond CO 2 laser will open new opportunities for studying ultra-relativistic laser interactions with plasma in the MIR spectral domain, including new regimesmore » in the particle acceleration of ions and electrons.« less

Asymmetric Radical Cyclopropanation of Alkenes with In Situ-Generated Donor-Substituted Diazo Reagents via Co(II)-Based Metalloradical Catalysis.

PubMed

Wang, Yong; Wen, Xin; Cui, Xin; Wojtas, Lukasz; Zhang, X Peter

2017-01-25

Donor-substituted diazo reagents, generated in situ from sulfonyl hydrazones in the presence of base, can serve as suitable radical precursors for Co(II)-based metalloradical catalysis (MRC). The cobalt(II) complex of D 2 -symmetric chiral porphyrin [Co(3,5-Di t Bu-Xu(2'-Naph)Phyrin)] is an efficient metalloradical catalyst that is capable of activating different N-arylsulfonyl hydrazones for asymmetric radical cyclopropanation of a broad range of alkenes, affording the corresponding cyclopropanes in high yields with effective control of both diastereo- and enantioselectivity. This Co(II)-based metalloradical system represents the first catalytic protocol that can effectively utilize donor-type diazo reagents for asymmetric olefin cyclopropanation.

Comparison of carbohydrate sources in yeast-fermentation CO2 generators for mosquito surveillance

USDA-ARS?s Scientific Manuscript database

Mosquito surveillance in remote areas with limited access to canisters of CO2 or dry ice will benefit from an effective alternative CO2 source, such as the natural production of CO2 from yeast fermentation of several carbohydrate sources. In this study, we document the differences in mosquito and n...

Pendant acid-base groups in molecular catalysts: H-bond promoters or proton relays? Mechanisms of the conversion of CO2 to CO by electrogenerated iron(0)porphyrins bearing prepositioned phenol functionalities.

PubMed

Costentin, Cyrille; Passard, Guillaume; Robert, Marc; Savéant, Jean-Michel

2014-08-20

Two derivatives of iron tetraphenylporphyrin bearing prepositioned phenolic functionalities on two of the opposed phenyl groups prove to be remarkable catalysts for the reduction of CO2 to CO when generated electrochemically at the Fe(0) oxidation state. In one case, the same substituents are present on the two other phenyls, whereas in the other the two other phenyls are perfluorinated. They are taken as examples of the possible role of pendant acid-base groups in molecular catalysis. The prepositioned phenol groups incorporated into the catalyst molecule induce strong stabilization of the initial Fe(0)CO2 adduct through H-bonding, confirmed by DFT calculations. This positive factor is partly counterbalanced by the necessity, resulting from the same stabilization, to inject an additional electron to trigger catalysis. Thanks to the preprotonation of the initial Fe(0)CO2 adduct, the potential required for this second electron transfer is not very distant from the potential at which the adduct is generated by addition of CO2 to the Fe(0) complex. The protonation step involves an internal phenolic group and the reprotonation of the phenoxide ion thus generated by added phenol. The prepositioned phenol groups thus play both the role of H-bonding stabilizers and high-concentration proton donors. They play the same role in the second electron transfer step which closes the catalytic loop concertedly with the breaking of one of the two C-O bonds of CO2 and with proton transfer. It is also remarkable that reprotonation by added phenol is concerted with the three other events.

Multifluid geo-energy systems: Using geologic CO 2 storage for geothermal energy production and grid-scale energy storage in sedimentary basins

DOE PAGES

Buscheck, Thomas A.; Bielicki, Jeffrey M.; Edmunds, Thomas A.; ...

2016-05-05

We present an approach that uses the huge fluid and thermal storage capacity of the subsurface, together with geologic carbon dioxide (CO 2) storage, to harvest, store, and dispatch energy from subsurface (geothermal) and surface (solar, nuclear, fossil) thermal resources, as well as excess energy on electric grids. Captured CO 2 is injected into saline aquifers to store pressure, generate artesian flow of brine, and provide a supplemental working fluid for efficient heat extraction and power conversion. Concentric rings of injection and production wells create a hydraulic mound to store pressure, CO 2, and thermal energy. This energy storage canmore » take excess power from the grid and excess/waste thermal energy, and dispatch that energy when it is demanded and thus enable higher penetration of variable renewable energy technologies (e.g., wind, solar). CO 2 stored in the subsurface functions as a cushion gas to provide enormous pressure-storage capacity and displace large quantities of brine, some of which can be treated for a variety of beneficial uses. Geothermal power and energy-storage applications may generate enough revenues to compensate for CO 2 capture costs. While our approach can use nitrogen (N 2), in addition to CO 2, as a supplemental fluid, and store thermal energy, this study focuses using CO 2 for geothermal energy production and grid-scale energy storage. We conduct a techno-economic assessment to determine the levelized cost of electricity of using this approach to generate geothermal power. We present a reservoir pressure-management strategy that diverts a small portion of the produced brine for beneficial consumptive use to reduce the pumping cost of fluid recirculation, while reducing the risk of seismicity, caprock fracture, and CO 2 leakage.« less

Recuperative supercritical carbon dioxide cycle

DOEpatents

Sonwane, Chandrashekhar; Sprouse, Kenneth M; Subbaraman, Ganesan; O'Connor, George M; Johnson, Gregory A

2014-11-18

A power plant includes a closed loop, supercritical carbon dioxide system (CLS-CO.sub.2 system). The CLS-CO.sub.2 system includes a turbine-generator and a high temperature recuperator (HTR) that is arranged to receive expanded carbon dioxide from the turbine-generator. The HTR includes a plurality of heat exchangers that define respective heat exchange areas. At least two of the heat exchangers have different heat exchange areas.

Production of stable isotope-labeled acyl-coenzyme A thioesters by yeast stable isotope labeling by essential nutrients in cell culture

PubMed Central

Snyder, Nathaniel W.; Tombline, Gregory; Worth, Andrew J.; Parry, Robert C.; Silvers, Jacob A.; Gillespie, Kevin P.; Basu, Sankha S.; Millen, Jonathan; Goldfarb, David S.; Blair, Ian A.

2015-01-01

Acyl-coenzyme A (CoA) thioesters are key metabolites in numerous anabolic and catabolic pathways, including fatty acid biosynthesis and β-oxidation, the Krebs cycle, and cholesterol and isoprenoid biosynthesis. Stable isotope dilution-based methodology is the gold standard for quantitative analyses by mass spectrometry. However, chemical synthesis of families of stable isotope labeled metabolites such as acyl-coenzyme A thioesters is impractical. Previously, we biosynthetically generated a library of stable isotope internal standard analogs of acyl-CoA thioesters by exploiting the essential requirement in mammals and insects for pantothenic acid (vitamin B5) as a metabolic precursor for the CoA backbone. By replacing pantothenic acid in the cell media with commercially available [13C3 15N1]-pantothenic acid, mammalian cells exclusively incorporated [13C3 15N1]-pantothenate into the biosynthesis of acyl-CoA and acyl-CoA thioesters. We have now developed a much more efficient method for generating stable isotope labeled CoA and acyl-CoAs from [13C3 15N1]-pantothenate using Stable Isotope Labeling by Essential nutrients in Cell culture (SILEC) in Pan6 deficient yeast cells. Efficiency and consistency of labeling were also increased, likely due to the stringently defined and reproducible conditions used for yeast culture. The yeast SILEC method greatly enhances the ease of use and accessibility of labeled CoA thioesters and also provides proof-of-concept for generating other labeled metabolites in yeast mutants. PMID:25572876

Label-free fluorescent enzymatic assay of citrate synthase by CoA-Au(I) co-ordination polymer and its application in a multi-enzyme logic gate cascade.

PubMed

Li, Yong; Wang, Huixia; Dai, Futao; Li, Pei; Jin, Xin; Huang, Yan; Nie, Zhou; Yao, Shouzhuo

2016-12-15

Citrate synthase (CS) is one of the key metabolic enzymes in the Krebs tricarboxylic acid (TCA) cycle. It regulates energy generation in mitochondrial respiration by catalysing the reaction between oxaloacetic acid (OAA) and acetyl coenzyme A (Ac-CoA) to generate citrate and coenzyme A (CoA). CS has been shown to be a biomarker of neurological diseases and various kinds of cancers. Here, a label-free fluorescent assay has been developed for homogeneously detecting CS and its inhibitor based on the in situ generation of CoA-Au(I) co-ordination polymer (CP) and the fluorescence signal-on by SYBR Green II-stained CoA-Au(I) CP. Because of the unique property of the CoA-Au(I) CP, this CS activity assay method could achieve excellent selectivity and sensitivity, with a linear range from 0.0033 U/μL to 0.264 U/μL and a limit of detection to be 0.00165 U/μL. Meanwhile, this assay method has advantages of being facile and cost effective with quick detection. Moreover, based on this method, a biomimetic logic system was established by rationally exploiting the cascade enzymatic interactions in TCA cycle for chemical information processing. In the TCA cycle-derived logic system, an AND-AND-AND-cascaded gate was rigorously operated step by step in one pot, and is outputted by a label-free fluorescent signal with visualized readout. Copyright © 2016 Elsevier B.V. All rights reserved.

Electrocoagulation mechanism of perfluorooctanoate (PFOA) on a zinc anode: Influence of cathodes and anions.

PubMed

Wang, Yujuan; Lin, Hui; Jin, Fangyuan; Niu, Junfeng; Zhao, Jinbo; Bi, Ying; Li, Ying

2016-07-01

Batch experiments were conducted to investigate the effects of cathode materials and anions (Cl(-), SO4(2-), NO3(-), and CO3(2-)/HCO3(-)) on perfluorooctanoate (PFOA) removal in electrocoagulation process using zinc anode. The results indicated that the hydroxide flocs generated in-situ in the electrocoagulation process using the stainless steel rod as cathode were more effective than those using aluminum rod as cathode for the removal of PFOA after 20min of electrocoagulation at a current density of 0.5mAcm(-2). Hydroxide flocs generated in-situ in the electrocoagulation in the presence of Cl(-)/NO3(-) could effectively remove PFOA from aqueous solution with the removal ratios of 99.7%/98.1% and 98.9%/97.3% using stainless steel rod and aluminum rod as cathode, respectively. However, the PFOA removal ratios were 96.2%/4.1% and 7.4%/4.6% using stainless steel rod and aluminum rod as cathode, respectively, in the presence of SO4(2-) and CO3(2-)/HCO3(-). The different removal ratios of PFOA during the electrocoagulation process were primarily due to the fact that the hydroxide flocs generated in-situ were different in the presence of diverse cathodes and anions. We firstly demonstrated that Zn0.70Al0.30(OH)2(CO3)0.15·xH2O and ZnO generated in-situ in the electrocoagulation process (except for CO3(2-)/HCO3(-)) using zinc anode and aluminum/stainless steel rod cathode governed the sorption of PFOA. The adsorbent hydroxide flocs in-situ generated in the presence of Cl(-) could effectively remove PFOA from aqueous solution containing CO3(2-)/HCO3(-) anion at the initial hydroxide flocs concentration of 2000mgL(-1). These results provided an effective and alternative method to remove PFOA from aqueous solution containing CO3(2-)/HCO3(-) anion. Copyright © 2016 Elsevier B.V. All rights reserved.

Energy Economics of Farm Biogas in Cold Climates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pillay, Pragasen; Grimberg, Stefan; Powers, Susan E

Anaerobic digestion of farm and dairy waste has been shown to be capital intensive. One way to improve digester economics is to co-digest high-energy substrates together with the dairy manure. Cheese whey for example represents a high-energy substrate that is generated during cheese manufacture. There are currently no quantitative tools available that predict performance of co-digestion farm systems. The goal of this project was to develop a mathematical tool that would (1) predict the impact of co-digestion and (2) determine the best use of the generated biogas for a cheese manufacturing plant. Two models were developed that separately could bemore » used to meet both goals of the project. Given current pricing structures of the most economical use of the generated biogas at the cheese manufacturing plant was as a replacement of fuel oil to generate heat. The developed digester model accurately predicted the performance of 26 farm digesters operating in the North Eastern U.S.« less

Effects of elevated CO2 on fish behaviour undiminished by transgenerational acclimation

NASA Astrophysics Data System (ADS)

Welch, Megan J.; Watson, Sue-Ann; Welsh, Justin Q.; McCormick, Mark I.; Munday, Philip L.

2014-12-01

Behaviour and sensory performance of marine fishes are impaired at CO2 levels projected to occur in the ocean in the next 50-100 years, and there is limited potential for within-generation acclimation to elevated CO2 (refs , ). However, whether fish behaviour can acclimate or adapt to elevated CO2 over multiple generations remains unanswered. We tested for transgenerational acclimation of reef fish olfactory preferences and behavioural lateralization at moderate (656 μatm) and high (912 μatm) end-of-century CO2 projections. Juvenile spiny damselfish, Acanthochromis polyacanthus, from control parents (446 μatm) exhibited an innate avoidance to chemical alarm cue (CAC) when reared in control conditions. In contrast, juveniles lost their innate avoidance of CAC and even became strongly attracted to CAC when reared at elevated CO2 levels. Juveniles from parents maintained at mid-CO2 and high-CO2 levels also lost their innate avoidance of CAC when reared in elevated CO2, demonstrating no capacity for transgenerational acclimation of olfactory responses. Behavioural lateralization was also disrupted for juveniles reared under elevated CO2, regardless of parental conditioning. Our results show minimal potential for transgenerational acclimation in this fish, suggesting that genetic adaptation will be necessary to overcome the effects of ocean acidification on behaviour.

Sustainable multipurpose biorefineries for third-generation biofuels and value-added co-products

USDA-ARS?s Scientific Manuscript database

Modern biorefinery facilities conduct many types of processes, including those producing advanced biofuels, commodity chemicals, biodiesel, and value-added co-products such as sweeteners and bioinsecticides, with many more co-products, chemicals and biofuels on the horizon. Most of these processes ...

Regulation of ROS Production and Vascular Function by Carbon Monoxide

PubMed Central

Choi, Yoon Kyung; Por, Elaine D.; Kwon, Young-Guen; Kim, Young-Myeong

2012-01-01

Carbon monoxide (CO) is a gaseous molecule produced from heme by heme oxygenase (HO). CO interacts with reduced iron of heme-containing proteins, leading to its involvement in various cellular events via its production of mitochondrial reactive oxygen species (ROS). CO-mediated ROS production initiates intracellular signal events, which regulate the expression of adaptive genes implicated in oxidative stress and functions as signaling molecule for promoting vascular functions, including angiogenesis and mitochondrial biogenesis. Therefore, CO generated either by exogenous delivery or by HO activity can be fundamentally involved in regulating mitochondria-mediated redox cascades for adaptive gene expression and improving blood circulation (i.e., O2 delivery) via neovascularization, leading to the regulation of mitochondrial energy metabolism. This paper will highlight the biological effects of CO on ROS generation and cellular redox changes involved in mitochondrial metabolism and angiogenesis. Moreover, cellular mechanisms by which CO is exploited for disease prevention and therapeutic applications will also be discussed. PMID:22928087

Supercritical CO2/Co-solvents Extraction of Porogen and Surfactant to Obtain

NASA Astrophysics Data System (ADS)

Lubguban, Jorge

2005-03-01

A method of pore generation by supercritical CO2 (SCCO2)/co-solvents extraction for the preparation of nanoporous organosilicate thin films for ultralow dielectric constant materials is investigated. A nanohybrid film was prepared from poly (propylene glycol) (PPG) and poly(methylsilsesquioxane) (PMSSQ) whereby the PPG porogen are entrapped within the crosslinked PMSSQ matrix. Another set of thin films was produced by liquid crystal templating whereby non-ionic (polyoxyethylene 10 stearyl ether) (Brij76) and ionic (cetyltrimethylammonium bromide) (CTAB) surfactant were used as sacrificial templates in a tetraethoxy silane (TEOS) and methyltrimethoxy silane (MTMS) based matrix. These two types of films were treated with SCCO2/co-solvents to remove porogen and surfactant templates. As a comparison, porous structures generated by thermal decomposition were also evaluated. It is found that SCCO2/co-solvents treatment produced closely comparable results with thermal decomposition. The results were evident from Fourier Transform Infrared (FT- IR) spectroscopy and optical constants data obtained from variable angle spectroscopic ellipsometry (VASE).

Coal and Coal/Biomass-Based Power Generation

EPA Science Inventory

For Frank Princiotta's book, Global Climate Change--The Technology Challenge Coal is a key, growing component in power generation globally. It generates 50% of U.S. electricity, and criteria emissions from coal-based power generation are being reduced. However, CO2 emissions m...

The effect of tobacco smoke exposure on the generation of reactive oxygen species and cellular membrane damage using co-culture model of blood brain barrier with astrocytes.

PubMed

Seo, Seung-Beom; Choe, Eun Sang; Kim, Kwang-Sik; Shim, Soon-Mi

2017-06-01

Brain tissue is known to be vulnerable to the exposure by tobacco smoke. Tobacco smoke can induce generation of reactive oxygen species (ROS), causing inflammatory activity and blood-brain barrier (BBB) impairment. The aim of the present study was to investigate the effect of tobacco smoke on cell cytotoxicity, generation of ROS, and cellular membrane damage in astrocytes and BBB using a co-culture system. Cell viability of U373MG cells was reduced in a dose-dependent manner, ranging from 96.7% to 40.3% by tobacco smoke condensate (TSC). Cell viability of U373MG co-cultured with human brain microvascular endothelial cells (HBMECs) was 104.9% at the IC 50 value of TSC. Trans-epithelial electric resistance values drastically decreased 80% following 12-h incubation. The value was maintained until 48 h and then increased at 72-h incubation (85%). It then decreased to 75% at 120 h. Generation of ROS increased in a dose-dependent manner, ranging from 102.7% to 107.9%, when various concentrations of TSC (4-16 mg/mL) were administered to the U373MG monoculture. When TSC was added into U373MG co-cultured with HBMECs, production of ROS ranged from 101.7% to 102.6%, slightly increasing over 12 h. Maximum exposure-generated ROS of 104.8% was reached at 24 h. Cell cytotoxicity and oxidative stress levels in the U373MG co-culture model system with HBMECs were lower than U373MG monoculture. HBMECs effectively acted as a barrier to protect the astrocytes (U373MG) from toxicity of TSC.

Changing pollutants to green biogases for the crop food cycle chain.

PubMed

Zong, B Y; Xu, F J; Zong, B D; Zhang, Z G

2012-09-01

When fossil fuels on the Earth are used up, which kind of green energy can be used to replace them? Do every bioenergy generation or crop food chain results in environmental pollution? These questions are major concerns in a world facing restricted supplies of energy and food as well as environmental pollutions. To alleviate these issues, option biogases are explored in this paper. Two types of biogas generators were used for modifying the traditional crop food chain [viz. from atmospheric CO(2) photosynthesis to crops, crop stem/husk biowastes (burnt in cropland or as home fuels), to livestock droppings (dumping away), pork and people foods, then to CO(2)], via turning the biowaste pollutants into green bioenergies. By analyzing the traditional food chain via observation method, the drawbacks of by-product biowastes were revealed. Also, the whole cycle chain was further analyzed to assess its "greenness," using experimental data and other information, such as the material balance (e.g., the absorbed CO(2), investment versus generated food, energy, and wastes). The data show that by using the two types of biogas generators, clean renewable bioenergy, crop food, and livestock meat could be continuously produced without creating any waste to the world. The modification chain largely reduced CO(2) greenhouse gas and had a low-cost investment. The raw materials for the gas generators were only the wastes of crop stems and livestock droppings. Thus, the recommended CO(2) bioenergy cycle chain via the modification also greatly solved the environmental biowaste pollutions in the world. The described two type biogases effectively addressed the issues on energy, food, and environmental pollution. The green renewable bioenergy from the food cycle chain may be one of suitable alternatives to fossil and tree fuels for agricultural countries.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Huan; Cheng, Liang; Chuah, Mooi Choo

In the generation, transmission, and distribution sectors of the smart grid, intelligence of field devices is realized by programmable logic controllers (PLCs). Many smart-grid subsystems are essentially cyber-physical energy systems (CPES): For instance, the power system process (i.e., the physical part) within a substation is monitored and controlled by a SCADA network with hosts running miscellaneous applications (i.e., the cyber part). To study the interactions between the cyber and physical components of a CPES, several co-simulation platforms have been proposed. However, the network simulators/emulators of these platforms do not include a detailed traffic model that takes into account the impactsmore » of the execution model of PLCs on traffic characteristics. As a result, network traces generated by co-simulation only reveal the impacts of the physical process on the contents of the traffic generated by SCADA hosts, whereas the distinction between PLCs and computing nodes (e.g., a hardened computer running a process visualization application) has been overlooked. To generate realistic network traces using co-simulation for the design and evaluation of applications relying on accurate traffic profiles, it is necessary to establish a traffic model for PLCs. In this work, we propose a parameterized model for PLCs that can be incorporated into existing co-simulation platforms. We focus on the DNP3 subsystem of slave PLCs, which automates the processing of packets from the DNP3 master. To validate our approach, we extract model parameters from both the configuration and network traces of real PLCs. Simulated network traces are generated and compared against those from PLCs. Our evaluation shows that our proposed model captures the essential traffic characteristics of DNP3 slave PLCs, which can be used to extend existing co-simulation platforms and gain further insights into the behaviors of CPES.« less

Electricity generation from carbon monoxide in a single chamber microbial fuel cell.

PubMed

Mehta, P; Hussain, A; Tartakovsky, B; Neburchilov, V; Raghavan, V; Wang, H; Guiot, S R

2010-05-05

Electricity production from carbon monoxide (CO) is demonstrated in a single chamber microbial fuel cell (MFC) with a CoTMPP-based air cathode. The MFC was inoculated with anaerobic sludge and continuously sparged with CO as a sole carbon source. Volumetric power output was maximized at a CO flow rate of 4.8LLR(-1)d(-1) reaching 6.4mWLR(-1). Several soluble and gaseous degradation products including hydrogen, methane, and acetate were detected, resulting in a relatively low apparent Coulombic efficiency of 8.7%. Tests also demonstrated electricity production from hydrogen and acetate with the highest and fastest increase in voltage exhibited after acetate injection. It is hypothesized that electricity generation in a CO-fed MFC is accomplished by a consortium of carboxydotrophic and carbon monoxide - tolerant anodophilic microorganisms. Crown Copyright © 2010. Published by Elsevier Inc. All rights reserved.

Opportunities for Decarbonizing Existing U.S. Coal-Fired Power Plants via CO2 Capture, Utilization and Storage.

PubMed

Zhai, Haibo; Ou, Yang; Rubin, Edward S

2015-07-07

This study employs a power plant modeling tool to explore the feasibility of reducing unit-level emission rates of CO2 by 30% by retrofitting carbon capture, utilization, and storage (CCUS) to existing U.S. coal-fired electric generating units (EGUs). Our goal is to identify feasible EGUs and their key attributes. The results indicate that for about 60 gigawatts of the existing coal-fired capacity, the implementation of partial CO2 capture appears feasible, though its cost is highly dependent on the unit characteristics and fuel prices. Auxiliary gas-fired boilers can be employed to power a carbon capture process without significant increases in the cost of electricity generation. A complementary CO2 emission trading program can provide additional economic incentives for the deployment of CCS with 90% CO2 capture. Selling and utilizing the captured CO2 product for enhanced oil recovery can further accelerate CCUS deployment and also help reinforce a CO2 emission trading market. These efforts would allow existing coal-fired EGUs to continue to provide a significant share of the U.S. electricity demand.

The CoQH2/CoQ Ratio Serves as a Sensor of Respiratory Chain Efficiency.

PubMed

Guarás, Adela; Perales-Clemente, Ester; Calvo, Enrique; Acín-Pérez, Rebeca; Loureiro-Lopez, Marta; Pujol, Claire; Martínez-Carrascoso, Isabel; Nuñez, Estefanía; García-Marqués, Fernando; Rodríguez-Hernández, María Angeles; Cortés, Ana; Diaz, Francisca; Pérez-Martos, Acisclo; Moraes, Carlos T; Fernández-Silva, Patricio; Trifunovic, Aleksandra; Navas, Plácido; Vazquez, Jesús; Enríquez, Jose A

2016-04-05

Electrons feed into the mitochondrial electron transport chain (mETC) from NAD- or FAD-dependent enzymes. A shift from glucose to fatty acids increases electron flux through FAD, which can saturate the oxidation capacity of the dedicated coenzyme Q (CoQ) pool and result in the generation of reactive oxygen species. To prevent this, the mETC superstructure can be reconfigured through the degradation of respiratory complex I, liberating associated complex III to increase electron flux via FAD at the expense of NAD. Here, we demonstrate that this adaptation is driven by the ratio of reduced to oxidized CoQ. Saturation of CoQ oxidation capacity induces reverse electron transport from reduced CoQ to complex I, and the resulting local generation of superoxide oxidizes specific complex I proteins, triggering their degradation and the disintegration of the complex. Thus, CoQ redox status acts as a metabolic sensor that fine-tunes mETC configuration in order to match the prevailing substrate profile. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Multi-agent simulation of generation expansion in electricity markets.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Botterud, A; Mahalik, M. R.; Veselka, T. D.

2007-06-01

We present a new multi-agent model of generation expansion in electricity markets. The model simulates generation investment decisions of decentralized generating companies (GenCos) interacting in a complex, multidimensional environment. A probabilistic dispatch algorithm calculates prices and profits for new candidate units in different future states of the system. Uncertainties in future load, hydropower conditions, and competitors actions are represented in a scenario tree, and decision analysis is used to identify the optimal expansion decision for each individual GenCo. We test the model using real data for the Korea power system under different assumptions about market design, market concentration, and GenCo'smore » assumed expectations about their competitors investment decisions.« less

Numerical analysis of radial inward flow turbine for CO2 based closed loop Brayton cycle

NASA Astrophysics Data System (ADS)

Kisan, Jadhav Amit; Govardhan, M.

2017-06-01

Last few decades have witnessed a phenomenal growth in the demand for power, which has driven the suppliers to find new sources of energy and increase the efficiency of power generation process. Power generation cycles are either steam based Rankine cycle or closed loop Brayton cycles providing an efficiency of 30 to 40%. An upcoming technology in this regard is the CO2 based Brayton cycle operating near the critical region which has applications in vast areas. Power generation of CO2 based Brayton cycle can vary from few kilowatts for waste heat recovery to hundreds of megawatts in sodium cooled fast reactors. A CO2 based Brayton cycle is being studied for power generation especially in mid-sized concentrated solar power plants by numerous research groups around the world. One of the main components of such a setting is its turbine. Simulating the flow conditions inside the turbine becomes very crucial in order to accurately predict the performance of the system. The flow inside radial inflow turbine is studied at various inlet temperatures and mass flow rates in order to predict the behavior of the turbine under various boundary conditions. The performance investigation of the turbine system is done on the basis of parameters such as total efficiency, pressure ratio, and power coefficient. Effect of different inlet stagnation temperature and exit mass flow rates on these parameters is also studied. Results obtained are encouraging for the use of CO2 as working fluid in Brayton cycle.

The Wagner-Nelson method can generate an accurate gastric emptying flow curve from CO2 data obtained by a 13C-labeled substrate breath test.

PubMed

Sanaka, Masaki; Yamamoto, Takatsugu; Ishii, Tarou; Kuyama, Yasushi

2004-01-01

In pharmacokinetics, the Wagner-Nelson (W-N) method can accurately estimate the rate of drug absorption from its urinary elimination rate. A stable isotope (13C) breath test attempts to estimate the rate of absorption of 13C, as an index of gastric emptying rate, from the rate of pulmonary elimination of 13CO2. The time-gastric emptying curve determined by the breath test is quite different from that determined by scintigraphy or ultrasonography. In this report, we have shown that the W-N method can adjust the difference. The W-N equation to estimate gastric emptying from breath data is as follows: the fractional cumulative amount of gastric contents emptied by time t = Abreath (t)/Abreath (infinity) + (1/0.65).d[Abreath (t)/Abreath (infinity) ]/dt, where Abreath (t) = the cumulative recovery of 13CO2 in breath by time t and Abreath ( infinity ) = the ultimate cumulative 13CO2 recovery. The emptying flow curve generated by ultrasonography was compared with that generated by the W-N method-adjusted breath test in 6 volunteers. The emptying curves by the W-N method were almost identical to those by ultrasound. The W-N method can generate an accurate emptying flow curve from 13CO2 data, and it can adjust the difference between ultrasonography and the breath test. Copyright 2004 S. Karger AG, Basel

D-D neutron generator development at LBNL.

PubMed

Reijonen, J; Gicquel, F; Hahto, S K; King, M; Lou, T-P; Leung, K-N

2005-01-01

The plasma and ion source technology group in Lawrence Berkeley National Laboratory is developing advanced, next generation D-D neutron generators. There are three distinctive developments, which are discussed in this presentation, namely, multi-stage, accelerator-based axial neutron generator, high-output co-axial neutron generator and point source neutron generator. These generators employ RF-induction discharge to produce deuterium ions. The distinctive feature of RF-discharge is its capability to generate high atomic hydrogen species, high current densities and stable and long-life operation. The axial neutron generator is designed for applications that require fast pulsing together with medium to high D-D neutron output. The co-axial neutron generator is aimed for high neutron output with cw or pulsed operation, using either the D-D or D-T fusion reaction. The point source neutron generator is a new concept, utilizing a toroidal-shaped plasma generator. The beam is extracted from multiple apertures and focus to the target tube, which is located at the middle of the generator. This will generate a point source of D-D, T-T or D-T neutrons with high output flux. The latest development together with measured data will be discussed in this article.

Optimal Design of Wind-PV-Diesel-Battery System using Genetic Algorithm

NASA Astrophysics Data System (ADS)

Suryoatmojo, Heri; Hiyama, Takashi; Elbaset, Adel A.; Ashari, Mochamad

Application of diesel generators to supply the load demand on isolated islands in Indonesia has widely spread. With increases in oil price and the concerns about global warming, the integration of diesel generators with renewable energy systems have become an attractive energy sources for supplying the load demand. This paper performs an optimal design of integrated system involving Wind-PV-Diesel-Battery system for isolated island with CO2 emission evaluation by using genetic algorithm. The proposed system has been designed for the hybrid power generation in East Nusa Tenggara, Indonesia-latitude 09.30S, longitude 122.0E. From simulation results, the proposed system is able to minimize the total annual cost of the system under study and reduce CO2 emission generated by diesel generators.

CO Dehydrogenase Genes Found in Metagenomic Fosmid Clones from the Deep Mediterranean Sea▿ †

PubMed Central

Martin-Cuadrado, Ana-Belen; Ghai, Rohit; Gonzaga, Aitor; Rodriguez-Valera, Francisco

2009-01-01

The use of carbon monoxide (CO) as a biological energy source is widespread in microbes. In recent years, the role of CO oxidation in superficial ocean waters has been shown to be an important energy supplement for heterotrophs (carboxydovores). The key enzyme CO dehydrogenase was found in both isolates and metagenomes from the ocean's photic zone, where CO is continuously generated by organic matter photolysis. We have also found genes that code for both forms I (low affinity) and II (high affinity) in fosmids from a metagenomic library generated from a 3,000-m depth in the Mediterranean Sea. Analysis of other metagenomic databases indicates that similar genes are also found in the mesopelagic and bathypelagic North Pacific and on the surfaces of this and other oceanic locations (in lower proportions and similarities). The frequency with which this gene was found indicates that this energy-generating metabolism would be at least as important in the bathypelagic habitat as it is in the photic zone. Although there are no data about CO concentrations or origins deep in the ocean, it could have a geothermal origin or be associated with anaerobic metabolism of organic matter. The identities of the microbes that carry out these processes were not established, but they seem to be representatives of either Bacteroidetes or Chloroflexi. PMID:19801465

Comparison of volatiles and mosquito capture efficacy for three carbohydrate sources in a yeast-fermentation CO2 generator

USDA-ARS?s Scientific Manuscript database

Mosquito surveillance in remote areas with limited access to canisters of CO2 or dry ice will benefit from an effective alternative CO2 source. In this study, we document the differences in mosquito and non-mosquito capture rates from CO2 baited (dry ice or yeast fermentation of carbohydrates) CDC t...

Strategic design of a ruthenium catalyst for both CO2 reduction and H2O oxidation: the electronic influence of the co-ligands.

PubMed

Das, Biswanath; Ezzedinloo, Lida; Bhadbhade, Mohan; Bucknall, Martin P; Colbran, Stephen B

2017-09-05

A new ruthenium(ii) complex capable of catalysing both CO 2 reduction and water oxidation was designed and synthesised. The electro-catalytic efficiency and robustness of the complex together with the electronic effect of its co-ligands were investigated to develop next generation dual activity electrocatalysts.

Solar reduction of CO.sub.2

DOEpatents

Jensen, Reed J.; Lyman, John L.; King, Joe D.; Guettler, Robert D.

2000-01-01

The red shift of the absorption spectrum of CO.sub.2 with increasing temperature permits the use of sunlight to photolyze CO.sub.2 to CO. The process of the present invention includes: preheating CO.sub.2 to near 1800 K; exposing the preheated CO.sub.2 to sunlight, whereby CO, O.sub.2 and O are produced; and cooling the hot product mix by rapid admixture with room temperature CO.sub.2. The excess thermal energy may be used to produce electricity and to heat additional CO.sub.2 for subsequent process steps. The product CO may be used to generate H.sub.2 by the shift reaction or to synthesize methanol.

A Method for Optimal Load Dispatch of a Multi-zone Power System with Zonal Exchange Constraints

NASA Astrophysics Data System (ADS)

Hazarika, Durlav; Das, Ranjay

2018-04-01

This paper presented a method for economic generation scheduling of a multi-zone power system having inter zonal operational constraints. For this purpose, the generator rescheduling for a multi area power system having inter zonal operational constraints has been represented as a two step optimal generation scheduling problem. At first, the optimal generation scheduling has been carried out for the zone having surplus or deficient generation with proper spinning reserve using co-ordination equation. The power exchange required for the deficit zones and zones having no generation are estimated based on load demand and generation for the zone. The incremental transmission loss formulas for the transmission lines participating in the power transfer process among the zones are formulated. Using these, incremental transmission loss expression in co-ordination equation, the optimal generation scheduling for the zonal exchange has been determined. Simulation is carried out on IEEE 118 bus test system to examine the applicability and validity of the method.

Strong magneto-optical effects in A Cr2O4 (A =Fe,Co ) spinel oxides generated by tetrahedrally coordinated transition metal ions

NASA Astrophysics Data System (ADS)

Kocsis, V.; Bordács, S.; Deisenhofer, J.; Kiss, L. F.; Ohgushi, K.; Kaneko, Y.; Tokura, Y.; Kézsmárki, I.

2018-03-01

Magneto-optical effects have been investigated over the infrared visible spectral range in A Cr2O4 (A =Fe,Co ) spinel oxides with noncollinear spin orders in their ground states. We found large magneto-optical Kerr rotation and ellipticity at the on-site d -d transitions of the A2 + ions located within the charge gap. The magneto-optical Kerr rotation of ϑKerr≈12∘ observed in CoCr2O4 is unprecedentedly large among magnetic semiconductors and points toward the uniqueness of tetrahedrally coordinated Co2 + ions in generating strong magneto-optical response. Criteria of strong magneto-optical effects emerging at on-site d -d transitions of transition metal ions are discussed.

Bioenergy residues applied as soil amendments: N2O emissions and C sequestration potential

NASA Astrophysics Data System (ADS)

Cayuela, M.; Kuikman, P.; Oenema, O.; Bakker, R.; van Groenigen, J.

2009-12-01

Biofuels have been proposed as environmentally benign substitutes to fossil fuels. There is, however, substantial uncertainty in the scientific literature about how an expanding bioenergy sector would interact with other land uses and what could be the environmental consequences. In the particular case of greenhouse gas balance, the magnitude of discrepancy is tremendously high among different studies. Such controversy has been often attributed to the way the co-products generated were accounted for. It is likely that the intensification of bioenergy production will lead to an increased input of these co-products to the soil as alternative amendments or fertilizers. However, limited research has been done to determine how this will influence microbial transformation processes in soil and thereby the emissions of greenhouse gases. Neither have related issues such as the stabilization of soil organic matter, soil structure and soil fertility been adequately studied. Here, we report a laboratory study on the effects of the application of bioenergy residues on C and N mineralization and greenhouse gas emissions in an agricultural soil. Ten co-products were selected from different energy sectors: anaerobic digestion (digestates), first generation biofuel residues (rapeseed meal, distilled dried grains with solubles), second generation biofuel residues (non-fermentables from hydrolysis of different lignocellulosic materials) and pyrolysis (biochars). They were added at the same N rate (150 kg N ha-1) to a moist (80% water filled pore space) sandy soil and incubated at 20 C for 60 days. Most residues followed fast mineralization dynamics with a flush of CO2 respiration within the first week. The biochars were the exception: they showed very low respiration rates. After 60 days, first generation biofuel residues had emitted more than 80% of added C as CO2. Around 60% was emitted in the case of second generation biofuel residues and 40% with digestates. Biochars were the most stable residues with the lowest CO2 loss between 0.5 and 5.8 % of total added C. Regarding N2O emissions, first generation biofuel residues led to the highest total N2O emissions (between 2.5 - 6.0% of added N). Second generation biofuel residues emitted between 1.0-2.0% of added N, whereas anaerobic digestates led to emissions lower than 1% of added N. The two biochars used in this study led to negative N2O emissions, i.e. lower than the blank soil. We conclude that, at least in the short term, the effects of biofuel residues on the combined greenhouse gas balance of the soil ranges from beneficial (biochar) via mixed (digestates, second generation biofuels) to manifestly detrimental (first generation biofuels). These effects should be taken into account in life cycle analyses of biofuel production.

High-solid Anaerobic Co-digestion of Sewage Sludge and Cattle Manure: The Effects of Volatile Solid Ratio and pH

PubMed Central

Dai, Xiaohu; Chen, Yang; Zhang, Dong; Yi, Jing

2016-01-01

High-solid anaerobic digestion is an attractive solution to the problem of sewage sludge disposal. One method that can be used to enhance the production of volatile fatty acids (VFAs) and the generation of methane from anaerobic digestion involves combining an alkaline pretreatment step with the synergistic effects of sewage sludge and cattle manure co-digestion, which improves the activity of key enzymes and microorganisms in the anaerobic co-digestion system to promote the digestion of organic waste. In this study, we describe an efficient strategy that involves adjusting the volatile solid (VS) ratio (sewage sludge/cattle manure: 3/7) and initial pH (9.0) to improve VFA production and methane generation from the co-digestion of sludge and manure. The experimental results indicate that the maximum VFA production was 98.33 g/kg-TS (total solid) at the optimal conditions. Furthermore, methane generation in a long-term semi-continuously operated reactor (at a VS ratio of 3/7 and pH of 9.0) was greater than 120.0 L/kg-TS. PMID:27725704

Inhibitory effect of self-generated extracellular dissolved organic carbon on carbon dioxide fixation in sulfur-oxidizing bacteria during a chemoautotrophic cultivation process and its elimination.

PubMed

Wang, Ya-Nan; Tsang, Yiu Fai; Wang, Lei; Fu, Xiaohua; Hu, Jiajun; Li, Huan; Le, Yiquan

2018-03-01

The features of extracellular dissolved organic carbon (EDOC) generation in two typical aerobic sulfur-oxidizing bacteria (Thiobacillus thioparus DSM 505 and Halothiobacillus neapolitanus DSM 15147) and its impact on CO 2 fixation during chemoautotrophic cultivation process were investigated. The results showed that EDOC accumulated in both strains during CO 2 fixation process. Large molecular weight (MW) EDOC derived from cell lysis and decay was dominant during the entire process in DSM 505, whereas small MW EDOC accounted for a large proportion during initial and middle stages of DSM 15147 as its cytoskeleton synthesis rate did not keep up with CO 2 assimilation rate. The self-generated EDOC feedback repressed cbb gene transcription and thus decreased total bacterial cell number and CO 2 fixation yield in both strains, but DSM 505 was more sensitive to this inhibition effect. Moreover, the membrane bioreactor effectively decreased the EDOC/TOC ratio and improved carbon fixation yield of DSM 505. Copyright © 2017 Elsevier Ltd. All rights reserved.

Protein kinase G–regulated production of H2S governs oxygen sensing

PubMed Central

Yuan, Guoxiang; Vasavda, Chirag; Peng, Ying-Jie; Makarenko, Vladislav V.; Raghuraman, Gayatri; Nanduri, Jayasri; Gadalla, Moataz M.; Semenza, Gregg L.; Kumar, Ganesh K.; Snyder, Solomon H.; Prabhakar, Nanduri R.

2015-01-01

Reflexes initiated by the carotid body, the principal O2-sensing organ, are critical for maintaining cardio-respiratory homeostasis during hypoxia. O2 sensing by the carotid body requires carbon monoxide (CO) generation by heme oxygenase-2 (HO-2) and hydrogen sulfide (H2S) synthesis by cystathionine-γ-lyase (CSE). We report that O2 stimulated the generation of CO, but not that of H2S, and required two cysteine residues in the heme regulatory motif (Cys265 and Cys282) of HO-2. CO stimulated protein kinase G (PKG)–dependent phosphorylation of Ser377 of CSE, inhibiting the production of H2S. Hypoxia decreased the inhibition of CSE by reducing CO generation resulting in increased H2S, which stimulated carotid body neural activity. In carotid bodies from mice lacking HO-2, compensatory increased abundance of nNOS (neuronal nitric oxide synthase) mediated O2 sensing through PKG-dependent regulation of H2S by nitric oxide. These results provide a mechanism for how three gases work in concert in the carotid body to regulate breathing. PMID:25900831

High-solid Anaerobic Co-digestion of Sewage Sludge and Cattle Manure: The Effects of Volatile Solid Ratio and pH

NASA Astrophysics Data System (ADS)

Dai, Xiaohu; Chen, Yang; Zhang, Dong; Yi, Jing

2016-10-01

High-solid anaerobic digestion is an attractive solution to the problem of sewage sludge disposal. One method that can be used to enhance the production of volatile fatty acids (VFAs) and the generation of methane from anaerobic digestion involves combining an alkaline pretreatment step with the synergistic effects of sewage sludge and cattle manure co-digestion, which improves the activity of key enzymes and microorganisms in the anaerobic co-digestion system to promote the digestion of organic waste. In this study, we describe an efficient strategy that involves adjusting the volatile solid (VS) ratio (sewage sludge/cattle manure: 3/7) and initial pH (9.0) to improve VFA production and methane generation from the co-digestion of sludge and manure. The experimental results indicate that the maximum VFA production was 98.33 g/kg-TS (total solid) at the optimal conditions. Furthermore, methane generation in a long-term semi-continuously operated reactor (at a VS ratio of 3/7 and pH of 9.0) was greater than 120.0 L/kg-TS.

Hydrogen generation from catalytic hydrolysis of alkaline sodium borohydride solution using attapulgite clay-supported Co-B catalyst

NASA Astrophysics Data System (ADS)

Tian, Hongjing; Guo, Qingjie; Xu, Dongyan

An attapulgite clay-supported cobalt-boride (Co-B) catalyst used in portable fuel cell fields is prepared in this paper by impregnation-chemical reduction method. The cost of attapulgite clay is much lower compared with some other inert carriers, such as activated carbon and carbon nanotube. Its microstructure and catalytic activity are analyzed in this paper. The effects of NaOH concentration, NaBH 4 concentration, reacting temperature, catalyst loadings and recycle times on the performance of the catalysts in hydrogen production from alkaline NaBH 4 solutions are investigated. Furthermore, characteristics of these catalysts are carried out in SEM, XRD and TEM analysis. The high catalytic activity of the catalyst indicates that it is a promising and practical catalyst. Activation energy of hydrogen generation using such catalysts is estimated to be 56.32 kJ mol -1. In the cycle test, from the 1st cycle to the 9th cycle, the average hydrogen generation rate decreases gradually from 1.27 l min -1 g -1 Co-B to 0.87 l min -1 g -1 Co-B.

Hydrogen generation from deliquescence of ammonia borane using Ni-Co/r-GO catalyst

NASA Astrophysics Data System (ADS)

Chou, Chang-Chen; Chen, Bing-Hung

2015-10-01

Hydrogen generation from the catalyzed deliquescence/hydrolysis of ammonia borane (AB) using the Ni-Co catalyst supported on the graphene oxide (Ni-Co/r-GO catalyst) under the conditions of limited water supply was studied with the molar feed ratio of water to ammonia borane (denoted as H2O/AB) at 2.02, 3.97 and 5.93, respectively. The conversion efficiency of ammonia borane to hydrogen was estimated both from the cumulative volume of the hydrogen gas generated and the conversion of boron chemistry in the hydrolysates analyzed by the solid-state 11B NMR. The conversion efficiency of ammonia borane could reach nearly 100% under excess water dosage, that is, H2O/AB = 3.97 and 5.93. Notably, the hydrogen storage capacity could reach as high as 6.5 wt.% in the case with H2O/AB = 2.02. The hydrolysates of ammonia borane in the presence of Ni-Co/r-GO catalyst were mainly the mixture of boric acid and metaborate according to XRD, FT-IR and solid-state 11B NMR analyses.

In situ-generated metal oxide catalyst during CO oxidation reaction transformed from redox-active metal-organic framework-supported palladium nanoparticles

PubMed Central

2012-01-01

The preparation of redox-active metal-organic framework (ra-MOF)-supported Pd nanoparticles (NPs) via the redox couple-driven method is reported, which can yield unprotected metallic NPs at room temperature within 10 min without the use of reducing agents. The Pd@ra-MOF has been exploited as a precursor of an active catalyst for CO oxidation. Under the CO oxidation reaction condition, Pd@ra-MOF is transformed into a PdOx-NiOy/C nanocomposite to generate catalytically active species in situ, and the resultant nanocatalyst shows sustainable activity through synergistic stabilization. PMID:22898143

High-temperature molten salt thermal energy storage systems for solar applications

NASA Astrophysics Data System (ADS)

Petri, R. J.; Claar, T. D.

1980-03-01

Alkali and alkaline earth carbonate latent-heat storage salts, metallic containment materials, and thermal conductivity enhancement materials were investigated to satisfy the high temperature (704 to 871 C) thermal energy storage requirements of advanced solar-thermal power generation concepts are described. Properties of the following six salts selected for compatibility studies are given: three pure carbonates, K2CO3, Li2CO3 and Na2CO3; two eutectic mixtures, BaCO3/Na2CO3 and K2CO3/NaCO3, and one off-eutectic mixture of Na2CO3/K2CO3.

High-temperature molten salt thermal energy storage systems for solar applications

NASA Technical Reports Server (NTRS)

Petri, R. J.; Claar, T. D.

1980-01-01

Alkali and alkaline earth carbonate latent-heat storage salts, metallic containment materials, and thermal conductivity enhancement materials were investigated to satisfy the high temperature (704 to 871 C) thermal energy storage requirements of advanced solar-thermal power generation concepts are described. Properties of the following six salts selected for compatibility studies are given: three pure carbonates, K2CO3, Li2CO3 and Na2CO3; two eutectic mixtures, BaCO3/Na2CO3 and K2CO3/NaCO3, and one off-eutectic mixture of Na2CO3/K2CO3.

Cooperative advanced-generation breeding and testing of coastal Douglas-fir and western hemlock—strategy and implementation.

Treesearch

K. J.S. Jayawickrama; G.R. Johnson; T. Ye

2005-01-01

As in many temperate regions of the world, forest tree improvement got underway in the Pacific Northwest of the USA in the 1950s, with a number of companies and agencies starting independent tree improvement programs. Booth-Kelly Lumber Co., Crown Zellerbach Corp., the Industrial Forestry Association, Port Blakely Mill Co., Simpson Timber Co., Timber Service Co., the...

Combustion Of Poultry-Derived Fuel in a CFBC

NASA Astrophysics Data System (ADS)

Jia, Lufei; Anthony, Edward J.

Poultry farming generates large quantities of waste. Current disposal practice is to spread the poultry wastes onto farmland as fertilizer. However, as the factory farms for poultry grow both in numbers and size, the amount of poultry wastes generated has increased significandy in recent years. In consequence, excessive application of poultry wastes on farmland is resulting in more and more contaminants entering the surface water. One of the options being considered is the use of poultry waste as power plant fuel. Since poultry-derived fuel (PDF) is biomass, its co-firing will have the added advantage of reducing greenhouse gas emissions from power generation. To evaluate the combustion characteristics of co-firing PDF with coal, combustion tests of mixtures of coal and PDF were conducted in CanmetENERGY's pilot-scale CFBC. The goal of the tests was to verify that PDF can be co-fired with coal and, more importantly, that emissions from the combustion process are not adversely affected by the presence of PDF in the fuel feed. The test results were very promising and support the view that co-firing in an existing coal-fired CFBC is an effective method of utilizing this potential fuel, both resolving a potential waste disposal problem and reducing the amount of CO2 released by the boiler.

Concurrent CO2 Control and O2 Generation for Advanced Life Support

NASA Technical Reports Server (NTRS)

Paul, Heather L.; Duncan, Keith L.; Hagelin-Weaver, Helena E.; Bishop, Sean R.; Wachsman, Eric D.

2007-01-01

The electrochemical reduction of carbon dioxide (CO2) using ceramic oxygen generators (COGs) is well known and widely studied, however, conventional devices using yttria-stabilized zirconia (YSZ) electrolytes operate at temperatures greater than 700 C. Operating at such high temperatures increases system mass compared to lower temperature systems because of increased energy overhead to get the COG up to operating temperature and the need for heavier insulation and/or heat exchangers to reduce the COG oxygen (O2) output temperature for comfortable inhalation. Recently, the University of Florida developed novel ceramic oxygen generators employing a bilayer electrolyte of gadolinia-doped ceria and erbia-stabilized bismuth for NASA's future exploration of Mars. To reduce landed mass and operation expenditures during the mission, in-situ resource utilization was proposed using these COGs to obtain both lifesupporting oxygen and oxidant/propellant fuel, by converting CO2 from the Mars atmosphere. The results showed that oxygen could be reliably produced from CO2 at temperatures as low as 400 C. These results indicate that this technology could be adapted to CO2 removal from a spacesuit and other applications in which CO2 removal was an issue. The strategy proposed for CO2 removal for advanced life support systems employs a catalytic layer combined with a COG so that it is reduced all the way to solid carbon and oxygen. Hence, a three-phased approach was used for the development of a viable low weight COG for CO2 removal. First, to reduce the COG operating temperature a high oxide ion conductivity electrolyte was developed. Second, to promote full CO2 reduction while avoiding the problem of carbon deposition on the COG cathode, novel cathodes and a removable catalytic carbon deposition layer were designed. Third, to improve efficiency, a pre-stage for CO2 absorption was used to concentrate CO2 from the exhalate before sending it to the COG. These subsystems were then integrated into a single CO2 removal system. This paper describes our progress to date on these tasks.

Assessment of cellular materials generated by co-cultured ‘inflamed’ and healthy periodontal ligament stem cells from patient-matched groups

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, Hao-Ning; Department of Stomatology, The First Affiliated Hospital of the Chinese PLA General Hospital, Beijing 100048; Xia, Yu

Recently, stem cells derived from the'inflamed’ periodontal ligament (PDL) tissue of periodontally diseased teeth (I-PDLSCs) have been increasingly suggested as a more readily accessible source of cells for regenerative therapies than those derived from healthy PDL tissue (H-PDLSCs). However, substantial evidence indicates that I-PDLSCs exhibit impaired functionalities compared with H-PDLSCs. In this study, patient-matched I-PDLSCs and H-PDLSCs were co-cultured at various ratios. Cellular materials derived from these cultures were investigated regarding their osteogenic potential in vitro and capacity to form new bone following in vivo transplantation. While patient-matched I-PDLSCs and H-PDLSCs could co-exist in co-culture systems, the proportion of I-PDLSCsmore » tended to increase during in vitro incubation. Compared with H-PDLSC monoculture, the presence of I-PDLSCs in the co-cultures appeared to enhance the overall cell proliferation. Although not completely rescued, the osteogenic and regenerative potentials of the cellular materials generated by co-cultured I-PDLSCs and H-PDLSCs were significantly improved compared with those derived from I-PDLSC monocultures. Notably, cells in co-cultures containing either 50% I-PDLSCs plus 50% H-PDLSCs or 25% I-PDLSCs plus 75% H-PDLSCs expressed osteogenesis-related proteins and genes at levels similar to those expressed in H-PDLSC monocultures (P>0.05). Irrespective of the percentage of I-PDLSCs, robust cellular materials were obtained from co-cultures with 50% or more H-PDLSCs, which exhibited equivalent potential to form new bone in vivo compared with sheets generated by H-PDLSC monocultures. These data suggest that the co-culture of I-PDLSCs with patient-matched H-PDLSCs is a practical and effective method for increasing the overall osteogenic and regenerative potentials of resultant cellular materials. - Highlights: • Co-culturing H-PDLSCs with I-PDLSCs led to rapid cell expansion. • H-PDLSCs and I-PDLSCs co-cultured at proper ratios retained cell differentiation. • Co-culturing proper ratios of H-PDLSCs and I-PDLSCs produced robust cell sheets. • I-PDLSCs can be used as an adjuvant to H-PDLSCs for yielding cellular materials.« less

Fluid Substitution Modeling to Determine Sensitivity of 3D Vertical Seismic Profile Data to Injected CO­2­ at an active Carbon Capture, Utilization and Storage Project, Farnsworth field, TX.

NASA Astrophysics Data System (ADS)

Haar, K. K.; Balch, R. S.

2015-12-01

The Southwest Regional Partnership on Carbon Sequestration monitors a CO2 capture, utilization and storage project at Farnsworth field, TX. The reservoir interval is a Morrowan age fluvial sand deposited in an incised valley. The sands are between 10 to 25m thick and located about 2800m below the surface. Primary oil recovery began in 1958 and by the late 1960's secondary recovery through waterflooding was underway. In 2009, Chaparral Energy began tertiary recovery using 100% anthropogenic CO2 sourced from an ethanol and a fertilizer plant. This constitutes carbon sequestration and fulfills the DOE's initiative to determine the best approach to permanent carbon storage. One purpose of the study is to understand CO­2 migration from injection wells. CO2­ plume spatial distribution for this project is analyzed with the use of time-lapse 3D vertical seismic profiles centered on CO2 injection wells. They monitor raypaths traveling in a single direction compared to surface seismic surveys with raypaths traveling in both directions. 3D VSP surveys can image up to 1.5km away from the well of interest, exceeding regulatory requirements for maximum plume extent by a factor of two. To optimize the timing of repeat VSP acquisition, the sensitivity of the 3D VSP surveys to CO2 injection was analyzed to determine at what injection volumes a seismic response to the injected CO­2 will be observable. Static geologic models were generated for pre-CO2 and post-CO2 reservoir states through construction of fine scale seismic based geologic models, which were then history matched via flow simulations. These generated static states of the model, where CO2­ replaces oil and brine in pore spaces, allow for generation of impedance volumes which when convolved with a representative wavelet generate synthetic seismic volumes used in the sensitivity analysis. Funding for the project is provided by DOE's National Energy Technology Laboratory (NETL) under Award No. DE-FC26-05NT42591.

High-Density Nanosharp Microstructures Enable Efficient CO2 Electroreduction.

PubMed

Saberi Safaei, Tina; Mepham, Adam; Zheng, Xueli; Pang, Yuanjie; Dinh, Cao-Thang; Liu, Min; Sinton, David; Kelley, Shana O; Sargent, Edward H

2016-11-09

Conversion of CO 2 to CO powered by renewable electricity not only reduces CO 2 pollution but also is a means to store renewable energy via chemical production of fuels from CO. However, the kinetics of this reaction are slow due its large energetic barrier. We have recently reported CO 2 reduction that is considerably enhanced via local electric field concentration at the tips of sharp gold nanostructures. The high local electric field enhances CO 2 concentration at the catalytic active sites, lowering the activation barrier. Here we engineer the nucleation and growth of next-generation Au nanostructures. The electroplating overpotential was manipulated to generate an appreciably increased density of honed nanoneedles. Using this approach, we report the first application of sequential electrodeposition to increase the density of sharp tips in CO 2 electroreduction. Selective regions of the primary nanoneedles are passivated using a thiol SAM (self-assembled monolayer), and then growth is concentrated atop the uncovered high-energy planes, providing new nucleation sites that ultimately lead to an increase in the density of the nanosharp structures. The two-step process leads to a new record in CO 2 to CO reduction, with a geometric current density of 38 mA/cm 2 at -0.4 V (vs reversible hydrogen electrode), and a 15-fold improvement over the best prior reports of electrochemical surface area (ECSA) normalized current density.

Simulation and analysis of stress in a Li-ion battery with a blended LiMn2O4 and LiNi0.8Co0.15Al0.05O2 cathode

NASA Astrophysics Data System (ADS)

Dai, Yiling; Cai, Long; White, Ralph E.

2014-02-01

Stress generation due to Li ion insertion into/extraction from LiMn2O4 particles is studied with a mathematical model for a lithium ion battery with pure LiMn2O4 or mixed LiMn2O4 and LiNi0.8Co0.15Al0.05O2 cathode. The simulated stress profile in a pure LiMn2O4 electrode shows nonuniformity across the positive electrode. The cathode blended model predicts that the stress generated in the LiMn2O4 particles is reduced at the end of discharge due to adding LiNi0.8Co0.15Al0.05O2 to the cathode. The effect of the variation in the blend ratio on the stress generation is also investigated.

An assessment of potential CO2 Sources throughout the Illinois Basin Subtask 5.1 – CO2 Source Assessment Topical Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patel, Vinodkumar; O?Brien, Kevin; Korose, Christopher

Large-scale anthropogenic CO2 sources (>100,000 tonnes/year) were catalogued and assessed for the Illinois East Sub-Basin project area. The portfolio of sources is quite diverse, and contains not only fossil-based power generation facilities but also ethanol, chemical, and refinery facilities. Over 60% of the facilities are relatively new (i.e. post year 2000 construction) hence increasing the likelihood that retrofitting the facility with a carbon capture plant is feasible. Two of the facilities have indicated interest in being “early adopters” should the CarbonSAFE project eventually transition to a build and operate phase: the Prairie State Generating Company’s electricity generation facility near Marissa,more » Illinois, and Quasar Syngas, LLC’s Wabash ammonia/direct-reduced iron plant, currently in development north of Terre Haute, Indiana.« less

Ionic Liquids for Utilization of Waste Heat from Distributed Power Generation Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joan F. Brennecke; Mihir Sen; Edward J. Maginn

2009-01-11

The objective of this research project was the development of ionic liquids to capture and utilize waste heat from distributed power generation systems. Ionic Liquids (ILs) are organic salts that are liquid at room temperature and they have the potential to make fundamental and far-reaching changes in the way we use energy. In particular, the focus of this project was fundamental research on the potential use of IL/CO2 mixtures in absorption-refrigeration systems. Such systems can provide cooling by utilizing waste heat from various sources, including distributed power generation. The basic objectives of the research were to design and synthesize ILsmore » appropriate for the task, to measure and model thermophysical properties and phase behavior of ILs and IL/CO2 mixtures, and to model the performance of IL/CO2 absorption-refrigeration systems.« less

Towards a Model of Human Resource Solutions for Achieving Intergenerational Interaction in Organisations

ERIC Educational Resources Information Center

McGuire, David; By, Rune Todnem; Hutchings, Kate

2007-01-01

Purpose: Achieving intergenerational interaction and avoiding conflict is becoming increasingly difficult in a workplace populated by three generations--Baby Boomers, Generation X-ers and Generation Y-ers. This paper presents a model and proposes HR solutions towards achieving co-operative generational interaction. Design/methodology/approach:…

Thermophotovoltaic systems for civilian and industrial applications in Japan

NASA Astrophysics Data System (ADS)

Yugami, Hiroo; Sasa, Hiromi; Yamaguchi, Masafumi

2003-05-01

The potential market for thermophotovoltaic (TPV) applications has been studied for civilian and industrial sectors in Japan. Comparing the performance of gas engines or turbines, as well as the underdeveloped power generation technologies such as fuel cells or chemical batteries, we have discussed the feasible application field of TPV systems to compete with those power generations. From the point of view of applicability for TPV systems in Japan, portable generators, co-generation systems and solar power plants are selected for our system analysis. The cost and performance targets of TPV systems for co-generation are also discussed by assuming a typical daily profile of electricity and hot water demands in Japanese homes. A progress report on the recent TPV research activities is given as well as a feasibility study concerning such TPV systems in Japan.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balashov, Victor N.; Brantley, Susan L.; Guthrie, George D.

One idea for mitigating the increase in fossil- fuel generated carbon dioxide (CO 2) in the atmosphere is to inject CO 2 into subsurface saline sandstone reservoirs, thereby storing it in those geologic formations and out of the atmosphere.

Aaron Bloom | NREL

Science.gov Websites

Todd Levin. "Wholesale Electricity Market Design with Increasing Levels of Renewable Generation . Evolution of Wholesale Electricity Market Design with Increasing Levels of Renewable Generation. Golden, CO

Near-term implications of a ban on new coal-fired power plants in the United States.

PubMed

Newcomer, Adam; Apt, Jay

2009-06-01

Large numbers of proposed new coal power generators in the United States have been canceled, and some states have prohibited new coal power generators. We examine the effects on the U.S. electric power system of banning the construction of coal-fired electricity generators, which has been proposed as a means to reduce U.S. CO2 emissions. The model simulates load growth, resource planning, and economic dispatch of the Midwest Independent Transmission System Operator (ISO), Inc., Electric Reliability Council of Texas (ERCOT), and PJM under a ban on new coal generation and uses an economic dispatch model to calculate the resulting changes in dispatch order, CO2 emissions, and fuel use under three near-term (until 2030) future electric power sector scenarios. A national ban on new coal-fired power plants does not lead to CO2 reductions of the scale required under proposed federal legislation such as Lieberman-Warner but would greatly increase the fraction of time when natural gas sets the price of electricity, even with aggressive wind and demand response policies.

Boosting methane generation by co-digestion of sludge with fruit and vegetable waste: Internal environment of digester and methanogenic pathway.

PubMed

Di Maria, Francesco; Barratta, Martino

2015-09-01

The effects of anaerobic co-digestion of waste-mixed sludge with fruit and vegetable waste (FVW) on the methane generation of a mesophilic digester was investigated. Organic loading rates (OLR) were 1.46kgVS/m(3)day, 2.1kgVS/m(3)day and 2.8kgVS/m(3)day. Increase in the OLR due to FVW co-digestion caused modification of the internal environment of the digester, mainly in terms of N-NH4 (mg/L). Corresponding microbial populations were investigated by metagenomic high-throughput sequencing. Maximum specific bio-methane generation of 435 NLCH4 per kgVS feed was achieved for an OLR of 2.1kgVS/m(3)day, which corresponded to a biomethane generation per kgVS removed of about 1700 NLCH4. In these conditions the methanogenic pathway was dominated by aceticlastic Methanosaeta and hydrogenotrophic/aceticlastic Methanoscarcinae. Ammonia concentration in the digester resulted a key parameter for enhancing syntrophic acetate oxidation, enabling a balanced aceticlastic and hydrogenotrophic/aceticlastic methanogenic pathway. Copyright © 2015 Elsevier Ltd. All rights reserved.

Insulation co-ordination aspects for power stations with generator circuit-breakers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanders, M.; Koeppl, G.; Kreuzer, J.

1995-07-01

The generator circuit-breaker (gen. c.b.) located between the generator and the step-up transformer, is now being applied world-wide. It has become a recognized electrical component of power stations which is largely due to economical advantages and increased power station availability. Technical protection considerations for power stations have always been the reason for discussion and the object of improvement. With the use of a gen. c.b., some points of view need to be considered anew. Not only the protection system in case of fault conditions will be influenced, but also the insulation co-ordination philosophy. Below the results of some calculations concerningmore » expected overvoltages are presented. These calculations are based on a transformer rated 264/15.5kV, 220 MVA. But the results are transferable to other power plants. Some measurements carried out on a transformer of the same rating complement the calculations. The findings may contribute to an improvement in insulation co-ordination and protection of the electrical system generator--step-up transformer.« less

Visible-light-driven methane formation from CO2 with a molecular iron catalyst.

PubMed

Rao, Heng; Schmidt, Luciana C; Bonin, Julien; Robert, Marc

2017-08-03

Converting CO 2 into fuel or chemical feedstock compounds could in principle reduce fossil fuel consumption and climate-changing CO 2 emissions. One strategy aims for electrochemical conversions powered by electricity from renewable sources, but photochemical approaches driven by sunlight are also conceivable. A considerable challenge in both approaches is the development of efficient and selective catalysts, ideally based on cheap and Earth-abundant elements rather than expensive precious metals. Of the molecular photo- and electrocatalysts reported, only a few catalysts are stable and selective for CO 2 reduction; moreover, these catalysts produce primarily CO or HCOOH, and catalysts capable of generating even low to moderate yields of highly reduced hydrocarbons remain rare. Here we show that an iron tetraphenylporphyrin complex functionalized with trimethylammonio groups, which is the most efficient and selective molecular electro- catalyst for converting CO 2 to CO known, can also catalyse the eight-electron reduction of CO 2 to methane upon visible light irradiation at ambient temperature and pressure. We find that the catalytic system, operated in an acetonitrile solution containing a photosensitizer and sacrificial electron donor, operates stably over several days. CO is the main product of the direct CO 2 photoreduction reaction, but a two-pot procedure that first reduces CO 2 and then reduces CO generates methane with a selectivity of up to 82 per cent and a quantum yield (light-to-product efficiency) of 0.18 per cent. However, we anticipate that the operating principles of our system may aid the development of other molecular catalysts for the production of solar fuels from CO 2 under mild conditions.

Visible-light-driven methane formation from CO2 with a molecular iron catalyst

NASA Astrophysics Data System (ADS)

Rao, Heng; Schmidt, Luciana C.; Bonin, Julien; Robert, Marc

2017-08-01

Converting CO2 into fuel or chemical feedstock compounds could in principle reduce fossil fuel consumption and climate-changing CO2 emissions. One strategy aims for electrochemical conversions powered by electricity from renewable sources, but photochemical approaches driven by sunlight are also conceivable. A considerable challenge in both approaches is the development of efficient and selective catalysts, ideally based on cheap and Earth-abundant elements rather than expensive precious metals. Of the molecular photo- and electrocatalysts reported, only a few catalysts are stable and selective for CO2 reduction; moreover, these catalysts produce primarily CO or HCOOH, and catalysts capable of generating even low to moderate yields of highly reduced hydrocarbons remain rare. Here we show that an iron tetraphenylporphyrin complex functionalized with trimethylammonio groups, which is the most efficient and selective molecular electro- catalyst for converting CO2 to CO known, can also catalyse the eight-electron reduction of CO2 to methane upon visible light irradiation at ambient temperature and pressure. We find that the catalytic system, operated in an acetonitrile solution containing a photosensitizer and sacrificial electron donor, operates stably over several days. CO is the main product of the direct CO2 photoreduction reaction, but a two-pot procedure that first reduces CO2 and then reduces CO generates methane with a selectivity of up to 82 per cent and a quantum yield (light-to-product efficiency) of 0.18 per cent. However, we anticipate that the operating principles of our system may aid the development of other molecular catalysts for the production of solar fuels from CO2 under mild conditions.

Rapid synthesis of Co, Ni co-doped ZnO nanoparticles: Optical and electrochemical properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Romeiro, Fernanda C.; Marinho, Juliane Z.; Lemos, Samantha C.S.

We report for the first time a rapid preparation of Zn{sub 1−2x}Co{sub x}Ni{sub x}O nanoparticles via a versatile and environmentally friendly route, microwave-assisted hydrothermal (MAH) method. The Co, Ni co-doped ZnO nanoparticles present an effect on photoluminescence and electrochemical properties, exhibiting excellent electrocatalytic performance compared to undoped ZnO sample. Photoluminescence spectroscopy measurements indicated the reduction of the green–orange–red visible emission region after adding Co and Ni ions, revealing the formation of alternative pathways for the generated recombination. The presence of these metallic ions into ZnO creates different defects, contributing to a local structural disorder, as revealed by Raman spectra. Electrochemicalmore » experiments revealed that the electrocatalytic oxidation of dopamine on ZnO attached to multi-walled carbon nanotubes improved significantly in the Co, Ni co-doped ZnO samples when compared to pure ZnO. - Graphical abstract: Rapid synthesis of Co, Ni co-doped ZnO nanoparticles: optical and electrochemical properties. Co, Ni co-doped ZnO hexagonal nanoparticles with optical and electrocatalytic properties were successfully prepared for the first time using a microwave hydrothermal method at mild conditions. - Highlights: • Co{sup 2+} and Ni{sup 2+} into ZnO lattice obtained a mild and environmentally friendly process. • The heating method strongly influences in the growth and shape of the particles. • Short-range defects generated by the ions insertion affects the photoluminescence. • Doped ZnO nanoparticles improve the electrocatalytic properties of pure oxide.« less

Effects of Evaluative vs. Co-Constructive Interactions on Learning in Physics

ERIC Educational Resources Information Center

Toczek, Marie-Christine; Morge, Ludovic

2009-01-01

We conducted an experimental study to assess the effects of two physics-learning situations that differed in the type of teacher-student interactions that took place: evaluative or co-constructive. As found in various studies on physics teaching and social psychology, the results showed that co-constructive interactions generated a more effective…

CO.sub.2 optically pumped distributed feedback diode laser

DOEpatents

Rockwood, Stephen D.

1980-01-01

A diode laser optically pumped by a CO.sub.2 coherent source. Interference fringes generated by feeding the optical pumping beam against a second beam, periodically alter the reflectivity of the diode medium allowing frequency variation of the output signal by varying the impingent angle of the CO.sub.2 laser beams.

Generating "Good Enough" Evidence for Co-Production

ERIC Educational Resources Information Center

Durose, Catherine; Needham, Catherine; Mangan, Catherine; Rees, James

2017-01-01

Co-production is not a new concept but it is one with renewed prominence and reach in contemporary policy discourse. It refers to joint working between people or groups who have traditionally been separated into categories of user and producer. The article focuses on the co-production of public services, offering theory-based and knowledge-based…

NIST Photoionization of CO2 (ARPES) Database

National Institute of Standards and Technology Data Gateway

SRD 119 NIST Photoionization of CO2 (ARPES) Database (Web, free access)   CO2 is studied using dispersed synchrotron radiation in the 650 Å to 850 Å spectral region. The vibrationally resolved photoelectron spectra are analyzed to generate relative vibrational transition amplitudes and the angular asymmetry parameters describing the various transitions observed.

Life cycle assessment of coal-fired power plants and sensitivity analysis of CO2 emissions from power generation side

NASA Astrophysics Data System (ADS)

Yin, Libao; Liao, Yanfen; Zhou, Lianjie; Wang, Zhao; Ma, Xiaoqian

2017-05-01

The life cycle assessment and environmental impacts of a 1000MW coal-fired power plant were carried out in this paper. The results showed that the operation energy consumption and pollutant emission of the power plant are the highest in all sub-process, which accounts for 93.93% of the total energy consumption and 92.20% of the total emission. Compared to other pollutant emissions from the coal-fired power plant, CO2 reached up to 99.28%. Therefore, the control of CO2 emission from the coal-fired power plants was very important. Based on the BP neural network, the amount of CO2 emission from the generation side of coal-fired power plants was calculated via carbon balance method. The results showed that unit capacity, coal quality and unit operation load had great influence on the CO2 emission from coal-fired power plants in Guangdong Province. The use of high volatile and high heat value of coal also can reduce the CO2 emissions. What’s more, under higher operation load condition, the CO2 emissions of 1 kWh electric energy was less.

Brief exposure to carbon monoxide preconditions cardiomyogenic cells against apoptosis in ischemia-reperfusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kondo-Nakamura, Mihoko; Shintani-Ishida, Kaori, E-mail: kaori@m.u-tokyo.ac.jp; Uemura, Koichi

We examined whether and how pretreatment with carbon monoxide (CO) prevents apoptosis of cardioblastic H9c2 cells in ischemia-reperfusion. Reperfusion (6 h) following brief ischemia (10 min) induced cytochrome c release, activation of caspase-9 and caspase-3, and apoptotic nuclear condensation. Brief CO pretreatment (10 min) or a caspase-9 inhibitor (Z-LEHD-FMK) attenuated these apoptotic changes. Ischemia-reperfusion increased phosphorylation of Akt at Ser472/473/474, and this was enhanced by CO pretreatment. A specific Akt inhibitor (API-2) blunted the anti-apoptotic effects of CO in reperfusion. In normoxic cells, CO enhanced O{sub 2}{sup -} generation, which was inhibited by a mitochondrial complex III inhibitor (antimycin A)more » but not by a NADH oxidase inhibitor (apocynin). The CO-enhanced Akt phosphorylation was suppressed by an O{sub 2}{sup -} scavenger (Tiron), catalase or a superoxide dismutase (SOD) inhibitor (DETC). These results suggest that CO pretreatment induces mitochondrial generation of O{sub 2}{sup -}, which is then converted by SOD to H{sub 2}O{sub 2}, and subsequent Akt activation by H{sub 2}O{sub 2} attenuates apoptosis in ischemia-reperfusion.« less

Performance of a new carbon dioxide absorbent, Yabashi lime® as compared to conventional carbon dioxide absorbent during sevoflurane anesthesia in dogs.

PubMed

Kondoh, Kei; Atiba, Ayman; Nagase, Kiyoshi; Ogawa, Shizuko; Miwa, Takashi; Katsumata, Teruya; Ueno, Hiroshi; Uzuka, Yuji

2015-08-01

In the present study, we compare a new carbon dioxide (CO2) absorbent, Yabashi lime(®) with a conventional CO2 absorbent, Sodasorb(®) as a control CO2 absorbent for Compound A (CA) and Carbon monoxide (CO) productions. Four dogs were anesthetized with sevoflurane. Each dog was anesthetized with four preparations, Yabashi lime(®) with high or low-flow rate of oxygen and control CO2 absorbent with high or low-flow rate. CA and CO concentrations in the anesthetic circuit, canister temperature and carbooxyhemoglobin (COHb) concentration in the blood were measured. Yabashi lime(®) did not produce CA. Control CO2 absorbent generated CA, and its concentration was significantly higher in low-flow rate than a high-flow rate. CO was generated only in low-flow rate groups, but there was no significance between Yabashi lime(®) groups and control CO2 absorbent groups. However, the CO concentration in the circuit could not be detected (≤5ppm), and no change was found in COHb level. Canister temperature was significantly higher in low-flow rate groups than high-flow rate groups. Furthermore, in low-flow rate groups, the lower layer of canister temperature in control CO2 absorbent group was significantly higher than Yabashi lime(®) group. CA and CO productions are thought to be related to the composition of CO2 absorbent, flow rate and canister temperature. Though CO concentration is equal, it might be safer to use Yabashi lime(®) with sevoflurane anesthesia in dogs than conventional CO2 absorbent at the point of CA production.

Co-Transcriptional Assembly of Modified RNA Nanoparticles | NCI Technology Transfer Center | TTC

Cancer.gov

The National Cancer Institute’s Nanobiology Program seeks parties interested in collaborative research to co-develop a method to generate RNA molecules suitable for nanoparticle and biomedical applications.

Real-time measurements of endogenous CO production from vascular cells using an ultrasensitive laser sensor.

PubMed

Morimoto, Y; Durante, W; Lancaster, D G; Klattenhoff, J; Tittel, F K

2001-01-01

Carbon monoxide (CO) has been implicated as a biological messenger molecule analogous to nitric oxide. A compact gas sensor based on a midinfrared laser absorption spectroscopy was developed for direct and real-time measurement of trace levels (in approximate pmol) of CO release by vascular cells. The midinfrared light is generated by difference frequency mixing of two nearinfrared lasers in a nonlinear optical crystal. A strong infrared absorption line of CO (4.61 microm) is chosen for convenient CO detection without interference from other gas species. The generation of CO from cultured vascular smooth muscle cells was detected every 20 s without any chemical modification to the CO. The sensitivity of the sensor reached 6.9 pmol CO. CO synthesis was measured from untreated control cells (0.25 nmol per 10(7) cells/h), sodium nitroprusside-treated cells (0.29 nmol per 10(7) cells/h), and hemin-treated cells (0.49 nmol per 10(7) cells/h). The sensor also detected decreases in CO production after the addition of the heme oxygenase (HO) inhibitor tin protoporphyrin-IX (from 0.49 to 0.02 nmol per 10(7) cells/h) and increases after the administration of the HO substrate hemin (from 0.27 to 0.64 nmol per 10(7) cells/h). These results demonstrate that midinfrared laser absorption spectroscopy is a useful technique for the noninvasive and real-time detection of trace levels of CO from biological tissues.

Real-time measurements of endogenous CO production from vascular cells using an ultrasensitive laser sensor

NASA Technical Reports Server (NTRS)

Morimoto, Y.; Durante, W.; Lancaster, D. G.; Klattenhoff, J.; Tittel, F. K.

2001-01-01

Carbon monoxide (CO) has been implicated as a biological messenger molecule analogous to nitric oxide. A compact gas sensor based on a midinfrared laser absorption spectroscopy was developed for direct and real-time measurement of trace levels (in approximate pmol) of CO release by vascular cells. The midinfrared light is generated by difference frequency mixing of two nearinfrared lasers in a nonlinear optical crystal. A strong infrared absorption line of CO (4.61 microm) is chosen for convenient CO detection without interference from other gas species. The generation of CO from cultured vascular smooth muscle cells was detected every 20 s without any chemical modification to the CO. The sensitivity of the sensor reached 6.9 pmol CO. CO synthesis was measured from untreated control cells (0.25 nmol per 10(7) cells/h), sodium nitroprusside-treated cells (0.29 nmol per 10(7) cells/h), and hemin-treated cells (0.49 nmol per 10(7) cells/h). The sensor also detected decreases in CO production after the addition of the heme oxygenase (HO) inhibitor tin protoporphyrin-IX (from 0.49 to 0.02 nmol per 10(7) cells/h) and increases after the administration of the HO substrate hemin (from 0.27 to 0.64 nmol per 10(7) cells/h). These results demonstrate that midinfrared laser absorption spectroscopy is a useful technique for the noninvasive and real-time detection of trace levels of CO from biological tissues.

Preparation of transition metal nanoparticles and surfaces modified with (CO)polymers synthesized by RAFT

DOEpatents

McCormick, III., Charles L.; Lowe, Andrew B.; Sumerlin, Brent S.

2006-11-21

A new, facile, general one-phase method of generating thio-functionalized transition metal nanoparticles and surfaces modified by (co)polymers synthesized by the RAFT method is described. The method includes the stops of forming a (co)polymer in aqueous solution using the RAFT methodology, forming a colloidal transition metal precursor solution from an appropriate transition metal; adding the metal precursor solution or surface to the (co)polymer solution, adding a reducing agent into the solution to reduce the metal colloid in situ to produce the stabilized nanoparticles or surface, and isolating the stabilized nanoparticles or surface in a manner such that aggregation is minimized. The functionalized surfaces generated using these methods can further undergo planar surface modifications, such as functionalization with a variety of different chemical groups, expanding their utility and application.

Preparation of transition metal nanoparticles and surfaces modified with (co)polymers synthesized by RAFT

DOEpatents

McCormick, III, Charles L.; Lowe, Andrew B [Hattiesburg, MS; Sumerlin, Brent S [Pittsburgh, PA

2011-12-27

A new, facile, general one-phase method of generating thiol-functionalized transition metal nanoparticles and surfaces modified by (co)polymers synthesized by the RAFT method is described. The method includes the steps of forming a (co)polymer in aqueous solution using the RAFT methodology, forming a colloidal transition metal precursor solution from an appropriate transition metal; adding the metal precursor solution or surface to the (co)polymer solution, adding a reducing agent into the solution to reduce the metal colloid in situ to produce the stabilized nanoparticles or surface, and isolating the stabilized nanoparticles or surface in a manner such that aggregation is minimized. The functionalized surfaces generated using these methods can further undergo planar surface modifications, such as functionalization with a variety of different chemical groups, expanding their utility and application.

Rubber muscle actuation with pressurized CO2 from enzyme-catalyzed urea hydrolysis

NASA Astrophysics Data System (ADS)

Sutter, Thomas M.; Dickerson, Matthew B.; Creasy, Terry S.; Justice, Ryan S.

2013-09-01

A biologically inspired pneumatic pressure source was designed and sized to supply high pressure CO2(g) to power a rubber muscle actuator. The enzyme urease served to catalyze the hydrolysis of urea, producing CO2(g) that flowed into the actuator. The actuator’s power envelope was quantified by testing actuator response on a custom-built linear-motion rig. Reaction kinetics and available work density were determined by replacing the actuator with a double-action piston and measuring volumetric gas generation against a fixed pressure on the opposing piston. Under the conditions investigated, urease catalyzed the generation of up to 0.81 MPa (117 psi) of CO2(g) in the reactor headspace within 18 min, and the evolved gas produced a maximum work density of 0.65 J ml-1.

Cu/Mn bimetallic catalysis enables carbonylative Suzuki-Miyaura coupling with unactivated alkyl electrophiles.

PubMed

Pye, Dominic R; Cheng, Li-Jie; Mankad, Neal P

2017-07-01

A bimetallic system consisting of Cu-carbene and Mn-carbonyl co-catalysts was employed for carbonylative C-C coupling of arylboronic esters with alkyl halides, allowing for the convergent synthesis of ketones. The system operates under mild conditions and exhibits complementary reactivity to Pd catalysis. The method is compatible with a wide range of arylboronic ester nucleophiles and proceeds smoothly for both primary and secondary alkyl iodide electrophiles. Preliminary mechanistic experiments corroborate a hypothetical catalytic mechanism consisting of co-dependent cycles wherein the Cu-carbene co-catalyst engages in transmetallation to generate an organocopper nucleophile, while the Mn-carbonyl co-catalyst activates the alkyl halide electrophile by single-electron transfer and then undergoes reversible carbonylation to generate an acylmanganese electrophile. The two cycles then intersect with a heterobimetallic, product-releasing C-C coupling step.

Ru–protein–Co biohybrids designed for solar hydrogen production: understanding electron transfer pathways related to photocatalytic function† †Electronic supplementary information (ESI) available: Time traces of photocatalysis, additional EPR spectra and parameters, UV-visible spectroscopy data, and kinetic fits of TA traces. See DOI: 10.1039/c6sc03121h Click here for additional data file.

PubMed Central

Soltau, Sarah R.; Dahlberg, Peter D.; Niklas, Jens; Poluektov, Oleg G.; Mulfort, Karen L.

2016-01-01

A series of Ru–protein–Co biohybrids have been prepared using the electron transfer proteins ferredoxin (Fd) and flavodoxin (Fld) as scaffolds for photocatalytic hydrogen production. The light-generated charge separation within these hybrids has been monitored by transient optical and electron paramagnetic resonance spectroscopies. Two distinct electron transfer pathways are observed. The Ru–Fd–Co biohybrid produces up to 650 turnovers of H2 utilizing an oxidative quenching mechanism for Ru(ii)* and a sequential electron transfer pathway via the native [2Fe–2S] cluster to generate a Ru(iii)–Fd–Co(i) charge separated state that lasts for ∼6 ms. In contrast, a direct electron transfer pathway occurs for the Ru–ApoFld–Co biohybrid, which lacks an internal electron relay, generating Ru(i)–ApoFld–Co(i) charge separated state that persists for ∼800 μs and produces 85 turnovers of H2 by a reductive quenching mechanism for Ru(ii)*. This work demonstrates the utility of protein architectures for linking donor and catalytic function via direct or sequential electron transfer pathways to enable stabilized charge separation which facilitates photocatalysis for solar fuel production. PMID:28451142

YSZ-based sensor using Cr-Fe-based spinel-oxide electrodes for selective detection of CO.

PubMed

Anggraini, Sri Ayu; Fujio, Yuki; Ikeda, Hiroshi; Miura, Norio

2017-08-22

A selective carbon monoxide (CO) sensor was developed by the use of both of CuCrFeO 4 and CoCrFeO 4 as the sensing electrode (SE) for yttria-stabilized zirconia (YSZ)-based potentiometric sensor. The sensing-characteristic examinations of the YSZ-based sensors using each of spinel oxides as the single-SE sensor showed that CuCrFeO 4 -SE had the ability to detect CO, hydrocarbons and NO x gases, while CoCrFeO 4 -SE was sensitive to hydrocarbons and NO x gases. Thus, when both SEs were paired as a combined-SEs sensor, the resulting sensor could generate a selective response to CO at 450 °C under humid conditions. The sensor was also capable of detecting CO in the concentration range of 20-700 ppm. Its sensing mechanism that was examined via polarization-curve measurements was confirmed to be based on mixed-potential model. The CO response generated by the combined-SEs sensor was unaffected by the change of water vapor concentration in the range of 1.3-11.5 vol% H 2 O. Additionally, the sensing performance was stable during 13 days tested. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessment of cellular materials generated by co-cultured 'inflamed' and healthy periodontal ligament stem cells from patient-matched groups.

PubMed

Tang, Hao-Ning; Xia, Yu; Xu, Jie; Tian, Bei-Min; Zhang, Xi-Yu; Chen, Fa-Ming

2016-08-01

Recently, stem cells derived from the'inflamed' periodontal ligament (PDL) tissue of periodontally diseased teeth (I-PDLSCs) have been increasingly suggested as a more readily accessible source of cells for regenerative therapies than those derived from healthy PDL tissue (H-PDLSCs). However, substantial evidence indicates that I-PDLSCs exhibit impaired functionalities compared with H-PDLSCs. In this study, patient-matched I-PDLSCs and H-PDLSCs were co-cultured at various ratios. Cellular materials derived from these cultures were investigated regarding their osteogenic potential in vitro and capacity to form new bone following in vivo transplantation. While patient-matched I-PDLSCs and H-PDLSCs could co-exist in co-culture systems, the proportion of I-PDLSCs tended to increase during in vitro incubation. Compared with H-PDLSC monoculture, the presence of I-PDLSCs in the co-cultures appeared to enhance the overall cell proliferation. Although not completely rescued, the osteogenic and regenerative potentials of the cellular materials generated by co-cultured I-PDLSCs and H-PDLSCs were significantly improved compared with those derived from I-PDLSC monocultures. Notably, cells in co-cultures containing either 50% I-PDLSCs plus 50% H-PDLSCs or 25% I-PDLSCs plus 75% H-PDLSCs expressed osteogenesis-related proteins and genes at levels similar to those expressed in H-PDLSC monocultures (P>0.05). Irrespective of the percentage of I-PDLSCs, robust cellular materials were obtained from co-cultures with 50% or more H-PDLSCs, which exhibited equivalent potential to form new bone in vivo compared with sheets generated by H-PDLSC monocultures. These data suggest that the co-culture of I-PDLSCs with patient-matched H-PDLSCs is a practical and effective method for increasing the overall osteogenic and regenerative potentials of resultant cellular materials. Copyright © 2016 Elsevier Inc. All rights reserved.

Electrochemical carbon dioxide concentrator subsystem development

NASA Technical Reports Server (NTRS)

Koszenski, E. P.; Heppner, D. B.; Bunnell, C. T.

1986-01-01

The most promising concept for a regenerative CO2 removal system for long duration manned space flight is the Electrochemical CO2 Concentrator (EDC), which allows for the continuous, efficient removal of CO2 from the spacecraft cabin. This study addresses the advancement of the EDC system by generating subsystem and ancillary component reliability data through extensive endurance testing and developing related hardware components such as electrochemical module lightweight end plates, electrochemical module improved isolation valves, an improved air/liquid heat exchanger and a triple redundant relative humidity sensor. Efforts included fabrication and testing the EDC with a Sabatier CO2 Reduction Reactor and generation of data necessary for integration of the EDC into a space station air revitalization system. The results verified the high level of performance, reliability and durability of the EDC subsystem and ancillary hardware, verified the high efficiency of the Sabatier CO2 Reduction Reactor, and increased the overall EDC technology engineering data base. The study concluded that the EDC system is approaching the hardware maturity levels required for space station deployment.

Effect of the temperature and the CO2 concentration on the behaviour of the citric acid as a scale inhibitor of CaCO3

NASA Astrophysics Data System (ADS)

Blanco, K.; Aponte, H.; Vera, E.

2017-12-01

For all Industrial sector is important to extend the useful life of the materials that they use in their process, the scales of CaCO3 are common in situation where fluids are handled with high concentration of ions and besides this temperatures and CO2 concentration dissolved, that scale generates large annual losses because there is a reduction in the process efficiency or corrosion damage under deposit, among other. In order to find new alternatives to this problem, the citric acid was evaluated as scale of calcium carbonate inhibition in critical condition of temperature and concentration of CO2 dissolved. Once the results are obtained it was carried out the statistical evaluation in order to generate an equation that allow to see that behaviour, giving as result, a good efficiency of inhibition to the conditions evaluated the scales of products obtained were characterized through scanning electron microscopy.

Power-to-Syngas: An Enabling Technology for the Transition of the Energy System?

PubMed

Foit, Severin R; Vinke, Izaak C; de Haart, Lambertus G J; Eichel, Rüdiger-A

2017-05-08

Power-to-X concepts promise a reduction of greenhouse gas emissions simultaneously guaranteeing a safe energy supply even at high share of renewable power generation, thus becoming a cornerstone of a sustainable energy system. Power-to-syngas, that is, the electrochemical conversion of steam and carbon dioxide with the use of renewably generated electricity to syngas for the production of synfuels and high-value chemicals, offers an efficient technology to couple different energy-intense sectors, such as "traffic and transportation" and "chemical industry". Syngas produced by co-electrolysis can thus be regarded as a key-enabling step for a transition of the energy system, which offers additionally features of CO 2 -valorization and closed carbon cycles. Here, we discuss advantages and current limitations of low- and high-temperature co-electrolysis. Advances in both fundamental understanding of the basic reaction schemes and stable high-performance materials are essential to further promote co-electrolysis. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Modeling of process parameters for enhanced production of coenzyme Q10 from Rhodotorula glutinis.

PubMed

Balakumaran, Palanisamy Athiyaman; Meenakshisundaram, Sankaranarayanan

2015-01-01

Coenzyme Q10 (CoQ10) plays an indispensable role in ATP generation through oxidative phosphorylation and helps in scavenging superoxides generated during electron transfer reactions. It finds extensive applications specifically related to oxidative damage and metabolic dysfunctions. This article reports the use of a statistical approach to optimize the concentration of key variables for the enhanced production of CoQ10 by Rhodotorula glutinis in a lab-scale fermenter. The culture conditions that promote optimum growth and CoQ10 production were optimized and the interaction of significant variables para-hydroxybenzoic acid (PHB, 819.34 mg/L) and soybean oil (7.78% [v/v]) was studied using response surface methodology (RSM). CoQ10 production increased considerably from 10 mg/L (in control) to 39.2 mg/L in batch mode with RSM-optimized precursor concentration. In the fed-batch mode, PHB and soybean oil feeding strategy enhanced CoQ10 production to 78.2 mg/L.

In-Plume Emission Test Stand 2: emission factors for 10- to 100-kW U.S. military generators.

PubMed

Zhu, Dongzi; Nussbaum, Nicholas J; Kuhns, Hampden D; Chang, M-C Oliver; Sodeman, David; Uppapalli, Sebastian; Moosmüller, Hans; Chow, Judith C; Watson, John G

2009-12-01

Although emissions of air pollutants from some military tactical equipment are not subject to the emissions standards, local communities near military bases must conform to the National Ambient Air Quality Standards. Military diesel generators are widely used in training. A portable in-plume system was used to measure fuel-based emission factors (EFs) for particulate matter (PM), carbon monoxide (CO), nitrogen oxides (NOx), and hydrocarbons (HCs) for 30-, 60-, and 100-kW generators at five load levels and for cold starts. It was found that EFs depend on multiple parameters including engine size, engine load, unit age, and total running hours. The average CO EF of generators tested was 5% lower, and the average NOx EF was 63% lower than AP-42 estimates; average PM EF was 80% less than the AP-42 estimates. A 2002 model-year 60-kW engine produced 25% less PM than a 1995 engine of the same family with similar running hours. CO EFs decrease with increasing engine load, NOx EFs increase up to mid-loads and decrease slightly at high loads, PM EFs increase with loads for 30- and 60-kW engines. CO and PM have higher EFs and NOx has a lower EF during cold starts than during hot-stabilized operation. PM chemical source profiles were also examined.

pH/Ultrasound Dual-Responsive Gas Generator for Ultrasound Imaging-Guided Therapeutic Inertial Cavitation and Sonodynamic Therapy.

PubMed

Feng, Qianhua; Zhang, Wanxia; Yang, Xuemei; Li, Yuzhen; Hao, Yongwei; Zhang, Hongling; Hou, Lin; Zhang, Zhenzhong

2018-03-01

Herein, a pH/ultrasound dual-responsive gas generator is reported, which is based on mesoporous calcium carbonate (MCC) nanoparticles by loading sonosensitizer (hematoporphyrin monomethyl ether (HMME)) and modifying surface hyaluronic acid (HA). After pinpointing tumor regions with prominent targeting efficiency, HMME/MCC-HA decomposes instantaneously under the cotriggering of tumoral inherent acidic condition and ultrasound (US) irradiation, concurrently accompanying with CO 2 generation and HMME release with spatial/temporal resolution. Afterward, the CO 2 bubbling and bursting effect under US stimulus results in cavitation-mediated irreversible cell necrosis, as well as the blood vessel destruction to further occlude the blood supply, providing a "bystander effect." Meanwhile, reactive oxygen species generated from HMME can target the apoptotic pathways for effective sonodynamic therapy. Thus, the combination of apoptosis/necrosis with multimechanisms consequently results in a remarkable antitumor therapeutic efficacy, simultaneously minimizing the side effects on major organs. Moreover, the echogenic property of CO 2 make the nanoplatform as a powerful ultrasound contrast agent to identify cancerous lesions. Based on the above findings, such all-in-one drug delivery platform of HMME/MCC-HA is utilized to provide the US imaging guidance for therapeutic inertial cavitation and sonodynamic therapy simultaneously, which highlights possibilities of advancing cancer theranostics in biomedical fields. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Supercritical Carbon Dioxide Power Generation System Definition: Concept Definition and Capital Cost Estimate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoddard, Larry; Galluzzo, Geoff; Andrew, Daniel

The Department of Energy’s (DOE’s) Office of Renewable Power (ORP) has been tasked to provide effective program management and strategic direction for all of the DOE’s Energy Efficiency & Renewable Energy’s (EERE’s) renewable power programs. The ORP’s efforts to accomplish this mission are aligned with national energy policies, DOE strategic planning, EERE’s strategic planning, Congressional appropriation, and stakeholder advice. ORP is supported by three renewable energy offices, of which one is the Solar Energy Technology Office (SETO) whose SunShot Initiative has a mission to accelerate research, development and large scale deployment of solar technologies in the United States. SETO hasmore » a goal of reducing the cost of Concentrating Solar Power (CSP) by 75 percent of 2010 costs by 2020 to reach parity with base-load energy rates, and 30 percent further reductions by 2030. The SunShot Initiative is promoting the implementation of high temperature CSP with thermal energy storage allowing generation during high demand hours. The SunShot Initiative has funded significant research and development work on component testing, with attention to high temperature molten salts, heliostats, receiver designs, and high efficiency high temperature supercritical CO 2 (sCO2) cycles. DOE retained Black & Veatch to support SETO’s SunShot Initiative for CSP solar power tower technology in the following areas: 1. Concept definition, including costs and schedule, of a flexible test facility to be used to test and prove components in part to support financing. 2. Concept definition, including costs and schedule, of an integrated high temperature molten salt (MS) facility with thermal energy storage and with a supercritical CO 2 cycle generating approximately 10MWe. 3. Concept definition, including costs and schedule, of an integrated high temperature falling particle facility with thermal energy storage and with a supercritical CO 2 cycle generating approximately 10MWe. This report addresses the concept definition of the sCO2 power generation system, a sub-set of items 2 and 3 above. Other reports address the balance of items 1 to 3 above as well as the MS/sCO2 integrated 10MWe facility, Item 2.« less

Evaluating the CO 2 emissions reduction potential and cost of power sector re-dispatch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steinberg, Daniel C.; Bielen, David A.; Townsend, Aaron

Prior studies of the U.S. electricity sector have recognized the potential to reduce carbon dioxide (CO2) emissions by substituting generation from coal-fired units with generation from under-utilized and lower-emitting natural gas-fired units; in fact, this type of 're-dispatch' was invoked as one of the three building blocks used to set the emissions targets under the Environmental Protection Agency's Clean Power Plan. Despite the existence of surplus natural gas capacity in the U.S., power system operational constraints not often considered in power sector policy analyses, such as transmission congestion, generator ramping constraints, minimum generation constraints, planned and unplanned generator outages, andmore » ancillary service requirements, could limit the potential and increase the cost of coal-to-gas re-dispatch. Using a highly detailed power system unit commitment and dispatch model, we estimate the maximum potential for re-dispatch in the Eastern Interconnection, which accounts for the majority of coal capacity and generation in the U.S. Under our reference assumptions, we find that maximizing coal-to-gas re-dispatch yields emissions reductions of 230 million metric tons (Mt), or 13% of power sector emissions in the Eastern Interconnection, with a corresponding average abatement cost of $15-$44 per metric ton of CO2, depending on the assumed supply elasticity of natural gas.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rao, C.N.R., E-mail: cnrrao@jncasr.ac.in; Dey, Sunita

Generation of H{sub 2} and CO by splitting H{sub 2}O and CO{sub 2} respectively constitutes an important aspect of the present-day concerns with energy and environment. The solar thermochemical route making use of metal oxides is a viable means of accomplishing these reduction reactions. The method essentially involves reducing a metal oxide by heating and passing H{sub 2}O or CO{sub 2} over the nonstoichiometric oxide to cause reverse oxidation by abstracting oxygen from H{sub 2}O or CO{sub 2}. While ceria, perovskites and other oxides have been investigated for this purpose, recent studies have demonstrated the superior performance of perovskites ofmore » the type Ln{sub 1−x}A{sub x}Mn{sub 1−y}M{sub y}O{sub 3} (Ln=rare earth, A=alkaline earth, M=various +2 and +3 metal ions), in the thermochemical generation of H{sub 2} and CO. We present the important results obtained hitherto to point out how the alkaine earth and the Ln ions, specially the radius of the latter, determine the performance of the perovskites. The encouraging results obtained are exemplefied by Y{sub 0.5}Sr{sub 0.5}MnO{sub 3} which releases 483 µmol/g of O{sub 2} at 1673 K and produces 757 µmol/g of CO from CO{sub 2} at 1173 K. The production of H{sub 2} from H{sub 2}O is also quite appreciable. Modification of the B site ion of the perovskite also affects the performance. In addition to perovskites, we present the generation of H{sub 2} based on the Mn{sub 3}O{sub 4}/NaMnO{sub 2} cycle briefly. - Graphical abstract: Ln{sub 0.5}A{sub 0.5}Mn{sub 1−x}M{sub x}O{sub 3} (Ln=lanthanide; A=Ca, Sr; M=Al, Ga, Sc, Mg, Cr, Fe, Co) perovskites are employed for the two step thermochemical splitting of CO{sub 2} and H{sub 2}O for the generation of CO and H{sub 2}. - Highlights: • Perovskite oxides based on Mn are ideal for the two-step thermochemical splitting of CO{sub 2} and H{sub 2}O. • In Ln{sub 1−x}A{sub x}MnO{sub 3} perovskite (Ln=rare earth, A=alkaline earth) both Ln and A ions play major roles in the thermochemical process. • H{sub 2}O splitting is also achieved by the use of the Mn{sub 3}O{sub 4}-sodium carbonate system. • Thermochemical splitting of CO{sub 2} and H{sub 2}O using perovskite oxides is explained. • Mn based perovskites.« less

Relating the physical properties of volcanic rocks to the characteristics of ash generated by experimental abrasion

NASA Astrophysics Data System (ADS)

Buckland, Hannah M.; Eychenne, Julia; Rust, Alison C.; Cashman, Katharine V.

2018-01-01

Interactions between clasts in pyroclastic density currents (PDCs) generate volcanic ash that can be dispersed to the atmosphere in co-PDC plumes, and due to its small size, is far-travelled. We designed a series of experiments to determine the effects of pyroclast vesicularity and crystal content on the efficiency and type of ash generated by abrasion. Two different pyroclastic materials were used: (1) basaltic-andesite pyroclasts from Fuego volcano (Guatemala) with 26-46% vesicularity and high groundmass crystallinity and (2) tephri-phonolite Avellino pumice (Vesuvius, Italy) with 55-75% vesicularity and low groundmass crystallinity. When milled, both clast types produced bimodal grain size distributions with fine ash modes between 4 and 5φ (32-63 μm). Although the vesicular Avellino pumice typically generated more ash than the denser Fuego pyroclasts, the ash-generating potential of a single pyroclast was independent of density, and instead governed by heterogeneous crystal and vesicle textures. One consequence of these heterogeneities was to cause the vesicular Avellino clasts to split in addition to abrading, which further enhanced abrasion efficiency. The matrix characteristics also affected ash shape and componentry, which will influence the elutriation and transport properties of ash in the atmosphere. The experimental abrasion successfully replicated some of the characteristics of natural co-PDC ash samples, as shown by similarities in the Adherence Factor, which measures the proportion of attached matrix on phenocrysts, of both the experimentally generated ash and natural co-PDC ash samples. Our results support previous studies, which have shown that abrasion is an effective mechanism for generating fine ash that is similar in size ( 5φ; 30 μm) to that found in co-PDC deposits. We further show that both the abundance and nature (shape, density, components, size distribution) of those ash particles are strongly controlled by the matrix properties of the abraded pyroclasts.

SCALS: a fourth-generation study of assisted living technologies in their organisational, social, political and policy context

PubMed Central

Greenhalgh, Trisha; Shaw, Sara; Wherton, Joe; Hughes, Gemma; Lynch, Jenni; A'Court, Christine; Hinder, Sue; Fahy, Nick; Byrne, Emma; Finlayson, Alexander; Sorell, Tom; Procter, Rob; Stones, Rob

2016-01-01

Introduction Research to date into assisted living technologies broadly consists of 3 generations: technical design, experimental trials and qualitative studies of the patient experience. We describe a fourth-generation paradigm: studies of assisted living technologies in their organisational, social, political and policy context. Fourth-generation studies are necessarily organic and emergent; they view technology as part of a dynamic, networked and potentially unstable system. They use co-design methods to generate and stabilise local solutions, taking account of context. Methods and analysis SCALS (Studies in Co-creating Assisted Living Solutions) consists (currently) of 5 organisational case studies, each an English health or social care organisation striving to introduce technology-supported services to support independent living in people with health and/or social care needs. Treating these cases as complex systems, we seek to explore interdependencies, emergence and conflict. We employ a co-design approach informed by the principles of action research to help participating organisations establish, refine and evaluate their service. To that end, we are conducting in-depth ethnographic studies of people's experience of assisted living technologies (micro level), embedded in evolving organisational case studies that use interviews, ethnography and document analysis (meso level), and exploring the wider national and international context for assisted living technologies and policy (macro level). Data will be analysed using a sociotechnical framework developed from structuration theory. Ethics and dissemination Research ethics approval for the first 4 case studies has been granted. An important outcome will be lessons learned from individual co-design case studies. We will document the studies’ credibility and rigour, and assess the transferability of findings to other settings while also recognising unique aspects of the contexts in which they were generated. Academic outputs will include a cross-case analysis and progress in theory and method of fourth-generation assisted living technology research. We will produce practical guidance for organisations, policymakers, designers and service users. PMID:26880671

A mesh generation and machine learning framework for Drosophila gene expression pattern image analysis

PubMed Central

2013-01-01

Background Multicellular organisms consist of cells of many different types that are established during development. Each type of cell is characterized by the unique combination of expressed gene products as a result of spatiotemporal gene regulation. Currently, a fundamental challenge in regulatory biology is to elucidate the gene expression controls that generate the complex body plans during development. Recent advances in high-throughput biotechnologies have generated spatiotemporal expression patterns for thousands of genes in the model organism fruit fly Drosophila melanogaster. Existing qualitative methods enhanced by a quantitative analysis based on computational tools we present in this paper would provide promising ways for addressing key scientific questions. Results We develop a set of computational methods and open source tools for identifying co-expressed embryonic domains and the associated genes simultaneously. To map the expression patterns of many genes into the same coordinate space and account for the embryonic shape variations, we develop a mesh generation method to deform a meshed generic ellipse to each individual embryo. We then develop a co-clustering formulation to cluster the genes and the mesh elements, thereby identifying co-expressed embryonic domains and the associated genes simultaneously. Experimental results indicate that the gene and mesh co-clusters can be correlated to key developmental events during the stages of embryogenesis we study. The open source software tool has been made available at http://compbio.cs.odu.edu/fly/. Conclusions Our mesh generation and machine learning methods and tools improve upon the flexibility, ease-of-use and accuracy of existing methods. PMID:24373308

Distribution, origin and prediction of carbon dioxide in petroleum reservoirs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thrasher, J.; Fleet, A.J.

1995-08-01

High concentrations of carbon dioxide (CO{sub 2}) in petroleum reservoirs can significantly reduce the value of the discovery, by diluting any hydrocarbons, and by increasing production costs because of the increased likelihood of corrosion and scale formation. Huge volumes of CO{sub 2} have been found, for example in the Indonesian Natuna d-Alpha structure (estimated 240 tcf gas, of which around 70% is CO{sub 2}). This study reviews the possible sources of CO{sub 2} in the petroleum system, and the geological and geochemical data from some CO{sub 2} {open_quotes}polluted{close_quotes} reservoirs, to improve future predictions of the exploration risk of finding significantmore » CO{sub 2}. A number of case studies show that the most common geological circumstances for the occurrence of high concentrations of CO{sub 2} include: carbonates associated with post-trap igneous activity (e.g. Ibleo Platform, Sicily); reservoir close to hot basement (e.g. Cooper-Eromanga Basin, Australia) and deep faults close to traps (e.g. Gulf of Thailand). Less common circumstances for high proportions of CO{sub 2} in gas include: post-trap igneous activity and coals (e.g. Taranaki, New Zealand) and reservoirs associated with pre-oil window coaly kerogen (e.g. Malay Trough), although the volumes of CO{sub 2} generated from kerogen are usually low relative to volumes of hydrocarbons generated from kerogen.« less

Clams as CO2 generators: The Potamocorbula amurensis example in San Francisco Bay

USGS Publications Warehouse

Chauvaud, Laurent; Thompson, Janet K.; Cloern, James E.; Thouzeau, Gerard

2003-01-01

Respiration and calcium carbonate production by the invasive Asian clam, Potamocorbula amurensis, were calculated to assess their importance as CO2 sources in northern San Francisco Bay. Production, calculated using monthly population density and size structure measured at three sites over 7 yr and a shell length/CaCO3 conversion factor, averaged 221(±184)g CaCO3 m−2yr−1. Net calcium carbonate production by this exotic bivalve releases CO2 at a mean rate of 18(±17)g C m−2yr−1. Respiration by P. amurensis, estimated from secondary production, releases additional CO2 at a mean rate of 37(±34)g C m−2yr−1. Therefore, total net CO2 production by P. amurensis averages 55(±51)g C m−2yr−1 in an estuarine domain where net primary production consumes only 20g inorganic C m−2yr−1. CO2 production by P. amurensis in northern San Francisco Bay is an underestimate of the total CO2 supply from the calcified zoobenthic communities of San Francisco Bay, and results from other studies have suggested that this rate is not unusual for temperate estuaries. Global extrapolation yields a gross CO2 production rate in the world's estuaries of 1x1014g C yr−1, which suggests that calcified benthic organisms in estuaries generate CO2 equal in magnitude to the CO2 emissions from the world's lakes or from planetary volcanism (the net source is determined by the highly variable rate of CO2 consumption by carbonate dissolution). This biogenic CO2 source is increasing because of the continuing global translocation of mollusks and their successful colonization of new habitats.

Clams as CO2 generators: The Potamocorbula amurensis example in San Francisco Bay

USGS Publications Warehouse

Chauvaud, Laurent; Thompson, Janet K.; Cloern, James E.; Thouzeau, Gerard

2003-01-01

Respiration and calcium carbonate production by the invasive Asian clam, Potamocorbula amurensis, were calculated to assess their importance as CO2 sources in northern San Francisco Bay. Production, calculated using monthly population density and size structure measured at three sites over 7 yr and a shell length/CaCO3 conversion factor, averaged 221 (6184) g CaCO3 m22 yr21 . Net calcium carbonate production by this exotic bivalve releases CO2 at a mean rate of 18 (617) g C m22 yr21 . Respiration by P. amurensis, estimated from secondary production, releases additional CO2 at a mean rate of 37 (634) g C m22 yr21 . Therefore, total net CO2 production by P. amurensis averages 55 (651) g C m22 yr21 in an estuarine domain where net primary production consumes only 20 g inorganic C m22 yr21 . CO2 production by P. amurensis in northern San Francisco Bay is an underestimate of the total CO2 supply from the calcified zoobenthic communities of San Francisco Bay, and results from other studies have suggested that this rate is not unusual for temperate estuaries. Global extrapolation yields a gross CO2 production rate in the world’s estuaries of 1 3 1014 g C yr21 , which suggests that calcified benthic organisms in estuaries generate CO2 equal in magnitude to the CO2 emissions from the world’s lakes or from planetary volcanism (the net source is determined by the highly variable rate of CO2 consumption by carbonate dissolution). This biogenic CO2 source is increasing because of the continuing global translocation of mollusks and their successful colonization of new habitats.

Co- and contra-directional vertical coupling between ferromagnetic layers with grating for short-wavelength spin wave generation

NASA Astrophysics Data System (ADS)

Graczyk, Piotr; Zelent, Mateusz; Krawczyk, Maciej

2018-05-01

The possibility to generate short spin waves (SWs) is of great interest in the field of magnonics nowadays. We present an effective and technically affordable way of conversion of long SWs, which may be generated by conventional microwave antenna, to the short, sub-micrometer waves. It is achieved by grating-assisted resonant dynamic dipolar interaction between two ferromagnetic layers separated by some distance. We analyze criteria for the optimal conversion giving a semi-analytical approach for the coupling coefficient. We show by the numerical calculations the efficient energy transfer between layers which may be either of co-directional or contra-directional type. Such a system may operate either as a short spin wave generator or a frequency filter, moving forward possible application of magnonics.

Realization of zero-field skyrmions with high-density via electromagnetic manipulation in Pt/Co/Ta multilayers

NASA Astrophysics Data System (ADS)

He, Min; Peng, Licong; Zhu, Zhaozhao; Li, Gang; Cai, Jianwang; Li, Jianqi; Wei, Hongxiang; Gu, Lin; Wang, Shouguo; Zhao, Tongyun; Shen, Baogen; Zhang, Ying

2017-11-01

Taking advantage of the electron-current ability to generate, stabilize, and manipulate skyrmions prompts the application of skyrmion multilayers in room-temperature spintronic devices. In this study, the robust high-density skyrmions are electromagnetically generated from Pt/Co/Ta multilayers using Lorentz transmission electron microscopy. The skyrmion density is tunable and can be significantly enhanced. Remarkably, these generated skyrmions after optimized manipulation sustain at zero field with both the in-plane current and perpendicular magnetic field being switched off. The skyrmion generation and manipulation method demonstrated in this study opens up an alternative way to engineer skyrmion-based devices. The results also provide key data for further theoretical study to discover the nature of the interaction between the electric current and different spin configurations.

Biogas generation in anaerobic wastewater treatment under tetracycline antibiotic pressure

NASA Astrophysics Data System (ADS)

Lu, Meiqing; Niu, Xiaojun; Liu, Wei; Zhang, Jun; Wang, Jie; Yang, Jia; Wang, Wenqi; Yang, Zhiquan

2016-06-01

The effect of tetracycline (TC) antibiotic on biogas generation in anaerobic wastewater treatment was studied. A lab-scale Anaerobic Baffled Reactor (ABR) with three compartments was used. The reactor was operated with synthetic wastewater in the absence of TC and in the presence of 250 μg/L TC for 90 days, respectively. The removal rate of TC, volatile fatty acids (VFAs), biogas compositions (hydrogen (H2), methane (CH4), carbon dioxide (CO2)), and total biogas production in each compartment were monitored in the two operational conditions. Results showed that the removal rate of TC was 14.97-67.97% in the reactor. The presence of TC had a large negative effect on CH4 and CO2 generation, but appeared to have a positive effect on H2 production and VFAs accumulation. This response indicated that the methanogenesis process was sensitive to TC presence, but the acidogenesis process was insensitive. This suggested that the presence of TC had less influence on the degradation of organic matter but had a strong influence on biogas generation. Additionally, the decrease of CH4 and CO2 generation and the increase of H2 and VFAs accumulation suggest a promising strategy to help alleviate global warming and improve resource recovery in an environmentally friendly approach.

Grandfather caregivers: race and ethnic differences in poverty.

PubMed

Keene, Jennifer R; Prokos, Anastasia H; Held, Barbara

2012-01-01

We use data from the 2006 American Community Survey to examine race and ethnic differences in the effects of marital status and co-residence of the middle generation on the likelihood of poverty among grandfathers who have primary responsibility for co-resident grandchildren (N = 3,379). Logistic regression results indicate that race/ethnicity and household composition are significant predictors of poverty for grandfather caregivers: non-Hispanic white grandfathers, those who are married, and those with a co-resident middle generation are the least likely to be poor. The effects of race/ethnicity, marital status, and the presence of a middle generation are, however, contingent upon one another. Specifically, the negative effect of being married is lower among grandfathers who are Hispanic, African American, non-Hispanic, and non-Hispanics of other race/ethnic groups compared to whites. In addition, having a middle generation in the home has a larger negative effect on poverty for race/ethnic minority grandfathers than for non-Hispanic whites. Finally, the combined effects of marriage and a middle generation vary across race/ethnic group and are associated with lower chances of poverty among some groups compared with others. We use the theory of cumulative disadvantage to interpret these findings and suggest that race/ethnicity and household composition are synergistically related to economic resources for grandfather caregivers.

Biogas generation in anaerobic wastewater treatment under tetracycline antibiotic pressure

PubMed Central

Lu, Meiqing; Niu, Xiaojun; Liu, Wei; Zhang, Jun; Wang, Jie; Yang, Jia; Wang, Wenqi; Yang, Zhiquan

2016-01-01

The effect of tetracycline (TC) antibiotic on biogas generation in anaerobic wastewater treatment was studied. A lab-scale Anaerobic Baffled Reactor (ABR) with three compartments was used. The reactor was operated with synthetic wastewater in the absence of TC and in the presence of 250 μg/L TC for 90 days, respectively. The removal rate of TC, volatile fatty acids (VFAs), biogas compositions (hydrogen (H2), methane (CH4), carbon dioxide (CO2)), and total biogas production in each compartment were monitored in the two operational conditions. Results showed that the removal rate of TC was 14.97–67.97% in the reactor. The presence of TC had a large negative effect on CH4 and CO2 generation, but appeared to have a positive effect on H2 production and VFAs accumulation. This response indicated that the methanogenesis process was sensitive to TC presence, but the acidogenesis process was insensitive. This suggested that the presence of TC had less influence on the degradation of organic matter but had a strong influence on biogas generation. Additionally, the decrease of CH4 and CO2 generation and the increase of H2 and VFAs accumulation suggest a promising strategy to help alleviate global warming and improve resource recovery in an environmentally friendly approach. PMID:27341657

Introduction of water into the heme distal side by Leu65 mutations of an oxygen sensor, YddV, generates verdoheme and carbon monoxide, exerting the heme oxygenase reaction.

PubMed

Stranava, Martin; Martínková, Markéta; Stiborová, Marie; Man, Petr; Kitanishi, Kenichi; Muchová, Lucie; Vítek, Libor; Martínek, Václav; Shimizu, Toru

2014-11-01

The globin-coupled oxygen sensor, YddV, is a heme-based oxygen sensor diguanylate cyclase. Oxygen binding to the heme Fe(II) complex in the N-terminal sensor domain of this enzyme substantially enhances its diguanylate cyclase activity which is conducted in the C-terminal functional domain. Leu65 is located on the heme distal side and is important for keeping the stability of the heme Fe(II)-O2 complex by preventing the entry of the water molecule to the heme complex. In the present study, it was found that (i) Escherichia coli-overexpressed and purified L65N mutant of the isolated heme-bound domain of YddV (YddV-heme) contained the verdoheme iron complex and other modified heme complexes as determined by optical absorption spectroscopy and mass spectrometry; (ii) CO was generated in the reconstituted system composed of heme-bound L65N and NADPH:cytochrome P450 reductase as confirmed by gas chromatography; (iii) CO generation of heme-bound L65N in the reconstituted system was inhibited by superoxide dismutase and catalase. In a concordance with the result, the reactive oxygen species increased the CO generation; (iv) the E. coli cells overexpressing the L65N protein of YddV-heme also formed significant amounts of CO compared to the cells overexpressing the wild type protein; (v) generation of verdoheme and CO was also observed for other mutants at Leu65 as well, but to a lesser extent. Since Leu65 mutations are assumed to introduce the water molecule into the heme distal side of YddV-heme, it is suggested that the water molecule would significantly contribute to facilitating heme oxygenase reactions for the Leu65 mutants. Copyright © 2014 Elsevier Inc. All rights reserved.

Modeling DNP3 Traffic Characteristics of Field Devices in SCADA Systems of the Smart Grid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Huan; Cheng, Liang; Chuah, Mooi Choo

In the generation, transmission, and distribution sectors of the smart grid, intelligence of field devices is realized by programmable logic controllers (PLCs). Many smart-grid subsystems are essentially cyber-physical energy systems (CPES): For instance, the power system process (i.e., the physical part) within a substation is monitored and controlled by a SCADA network with hosts running miscellaneous applications (i.e., the cyber part). To study the interactions between the cyber and physical components of a CPES, several co-simulation platforms have been proposed. However, the network simulators/emulators of these platforms do not include a detailed traffic model that takes into account the impactsmore » of the execution model of PLCs on traffic characteristics. As a result, network traces generated by co-simulation only reveal the impacts of the physical process on the contents of the traffic generated by SCADA hosts, whereas the distinction between PLCs and computing nodes (e.g., a hardened computer running a process visualization application) has been overlooked. To generate realistic network traces using co-simulation for the design and evaluation of applications relying on accurate traffic profiles, it is necessary to establish a traffic model for PLCs. In this work, we propose a parameterized model for PLCs that can be incorporated into existing co-simulation platforms. We focus on the DNP3 subsystem of slave PLCs, which automates the processing of packets from the DNP3 master. To validate our approach, we extract model parameters from both the configuration and network traces of real PLCs. Simulated network traces are generated and compared against those from PLCs. Our evaluation shows that our proposed model captures the essential traffic characteristics of DNP3 slave PLCs, which can be used to extend existing co-simulation platforms and gain further insights into the behaviors of CPES.« less

Properties of Intermediates in the Catalytic Cycle of Oxalate Oxidoreductase and Its Suicide Inactivation by Pyruvate

PubMed Central

2017-01-01

Oxalate:ferredoxin oxidoreductase (OOR) is an unusual member of the thiamine pyrophosphate (TPP)-dependent 2-oxoacid:ferredoxin oxidoreductase (OFOR) family in that it catalyzes the coenzyme A (CoA)-independent conversion of oxalate into 2 equivalents of carbon dioxide. This reaction is surprising because binding of CoA to the acyl-TPP intermediate of other OFORs results in formation of a CoA ester, and in the case of pyruvate:ferredoxin oxidoreductase (PFOR), CoA binding generates the central metabolic intermediate acetyl-CoA and promotes a 105-fold acceleration of the rate of electron transfer. Here we describe kinetic, spectroscopic, and computational results to show that CoA has no effect on catalysis by OOR and describe the chemical rationale for why this cofactor is unnecessary in this enzymatic transformation. Our results demonstrate that, like PFOR, OOR binds pyruvate and catalyzes decarboxylation to form the same hydroxyethylidine–TPP (HE–TPP) intermediate and one-electron transfer to generate the HE–TPP radical. However, in OOR, this intermediate remains stranded at the active site as a covalent inhibitor. These and other results indicate that, like other OFOR family members, OOR generates an oxalate-derived adduct with TPP (oxalyl-TPP) that undergoes decarboxylation and one-electron transfer to form a radical intermediate remaining bound to TPP (dihydroxymethylidene–TPP). However, unlike in PFOR, where CoA binding drives formation of the product, in OOR, proton transfer and a conformational change in the “switch loop” alter the redox potential of the radical intermediate sufficiently to promote the transfer of an electron into the iron–sulfur cluster network, leading directly to a second decarboxylation and completing the catalytic cycle. PMID:28514140

Assessment of biogas production in Argentina from co-digestion of sludge and municipal solid waste.

PubMed

Morero, Betzabet; Vicentin, Rocio; Campanella, Enrique A

2017-03-01

In Argentina, there is an important potential to utilize organic waste to generate bioenergy. This work analyzes the environmental impacts and the energetic and economic requirements of the biogas produced by digesting the sewage sludge (SS) produced in a wastewater treatment plant in a medium city in Argentina. The SS is co-digested with the organic fraction of municipal solid waste (OFMSW), and the basis of this study is the life cycle assessment (LCA). The LCA is performed according to ISO 14040-44 using the SimaPro simulator. First, the transport of the raw materials to the biogas plant was defined. Then, the co-digestion and the biogas treatment for final use were evaluated. The co-digestion was improved with glycerol, and the generation of biogas was estimated using the GPS-X software. Two alternatives for the end use of biogas were considered: combined heat and power (CHP) and biomethane generation. For the first, H 2 S and water vapor were removed from the raw biogas stream, and for the second, also CO 2 was removed. The H 2 S removal process was simulated in the SuperPro software by anaerobic biofiltration. The same software was used to simulate the removal of CO 2 absorption-desorption with water as solvent. Finally, the environmental impacts related to the end use of biogas (CHP and biomethane) were evaluated. The environmental, energetic and economic analyses showed that the co-digestion of SS and OFMSW has great potential for reducing the environmental impacts and increasing the economic and energetic value of the substances via the production of biomethane, electricity and, potentially, fertilizer. Copyright © 2016 Elsevier Ltd. All rights reserved.

40 CFR 98.242 - GHGs to report.

Code of Federal Regulations, 2012 CFR

2012-07-01

... paragraphs (a) through (c) of this section: (a) CO2 CH4, and N2O process emissions from each petrochemical process unit. Process emissions include CO2 generated by reaction in the process and by combustion of...), report under this subpart the calculated CO2, CH4, and N2O emissions for each stationary combustion...

40 CFR 98.242 - GHGs to report.

Code of Federal Regulations, 2013 CFR

2013-07-01

... paragraphs (a) through (c) of this section: (a) CO2 CH4, and N2O process emissions from each petrochemical process unit. Process emissions include CO2 generated by reaction in the process and by combustion of...), report under this subpart the calculated CO2, CH4, and N2O emissions for each stationary combustion...

40 CFR 98.242 - GHGs to report.

Code of Federal Regulations, 2011 CFR

2011-07-01

... paragraphs (a) through (c) of this section: (a) CO2 CH4, and N2O process emissions from each petrochemical process unit. Process emissions include CO2 generated by reaction in the process and by combustion of...), report under this subpart the calculated CO2, CH4, and N2O emissions for each stationary combustion...

40 CFR 98.242 - GHGs to report.

Code of Federal Regulations, 2010 CFR

2010-07-01

... paragraphs (a) through (c) of this section: (a) CO2 CH4, and N2O process emissions from each petrochemical process unit. Process emissions include CO2 generated by reaction in the process and by combustion of...), report under this subpart the calculated CO2, CH4, and N2O emissions for each stationary combustion...

40 CFR 98.242 - GHGs to report.

Code of Federal Regulations, 2014 CFR

2014-07-01

... paragraphs (a) through (c) of this section: (a) CO2 CH4, and N2O process emissions from each petrochemical process unit. Process emissions include CO2 generated by reaction in the process and by combustion of...), report under this subpart the calculated CO2, CH4, and N2O emissions for each stationary combustion...

Acyl CoA synthetase 5 (ACSL5) ablation in mice increases energy expenditure and insulin sensitivity and delays fat absorption

USDA-ARS?s Scientific Manuscript database

Objective: The family of acyl-CoA synthetase enzymes (ACSL) activates fatty acids within cells to generate long chain fatty acyl CoA (FACoA). The differing metabolic fates of FACoAs such as incorporation into neutral lipids, phospholipids, and oxidation pathways are differentially regulated by the ...

Important role of calcium chloride in preventing carbon monoxide generation during desflurane degradation with alkali hydroxide-free carbon dioxide absorbents.

PubMed

Ando, Takahiro; Mori, Atsushi; Ito, Rie; Nishiwaki, Kimitoshi

2017-12-01

We investigated whether calcium chloride (CaCl 2 ), a supplementary additive in carbon dioxide (CO 2 ) absorbents, could affect carbon monoxide (CO) production caused by desflurane degradation, using a Japanese alkali-free CO 2 absorbent Yabashi Lime ® -f (YL-f), its CaCl 2 -free and 1% CaCl 2 -added derivatives, and other commercially available alkali-free absorbents with or without CaCl 2 . The reaction between 1 L of desflurane gas (3-10%) and 20 g of desiccated specimen was performed in an artificial closed-circuit anesthesia system for 3 min at 20 or 40 °C. The CO concentration was measured using a gas chromatograph equipped with a semiconductor sensor detector. The systems were validated by detecting dose-dependent CO production with an alkali hydroxide-containing CO 2 absorbent, Sodasorb ® . Compared with YL-f, the CaCl 2 -free derivative caused the production of significantly more CO, while the 1% CaCl 2 -added derivative caused the production of a comparable amount of CO. These phenomena were confirmed using commercially available absorbents AMSORB ® PLUS, an alkali-free absorbent with CaCl 2 , and LoFloSorb™, an alkali-free absorbent without CaCl 2 . These results suggest that CaCl 2 plays an important role in preventing CO generation caused by desflurane degradation with alkali hydroxide-free CO 2 absorbents like YL-f.

Candida albicans Utilizes a Modified β-Oxidation Pathway for the Degradation of Toxic Propionyl-CoA*

PubMed Central

Otzen, Christian; Bardl, Bettina; Jacobsen, Ilse D.; Nett, Markus; Brock, Matthias

2014-01-01

Propionyl-CoA arises as a metabolic intermediate from the degradation of propionate, odd-chain fatty acids, and some amino acids. Thus, pathways for catabolism of this intermediate have evolved in all kingdoms of life, preventing the accumulation of toxic propionyl-CoA concentrations. Previous studies have shown that fungi generally use the methyl citrate cycle for propionyl-CoA degradation. Here, we show that this is not the case for the pathogenic fungus Candida albicans despite its ability to use propionate and valerate as carbon sources. Comparative proteome analyses suggested the presence of a modified β-oxidation pathway with the key intermediate 3-hydroxypropionate. Gene deletion analyses confirmed that the enoyl-CoA hydratase/dehydrogenase Fox2p, the putative 3-hydroxypropionyl-CoA hydrolase Ehd3p, the 3-hydroxypropionate dehydrogenase Hpd1p, and the putative malonate semialdehyde dehydrogenase Ald6p essentially contribute to propionyl-CoA degradation and its conversion to acetyl-CoA. The function of Hpd1p was further supported by the detection of accumulating 3-hydroxypropionate in the hpd1 mutant on propionyl-CoA-generating nutrients. Substrate specificity of Hpd1p was determined from recombinant purified enzyme, which revealed a preference for 3-hydroxypropionate, although serine and 3-hydroxyisobutyrate could also serve as substrates. Finally, virulence studies in a murine sepsis model revealed attenuated virulence of the hpd1 mutant, which indicates generation of propionyl-CoA from host-provided nutrients during infection. PMID:24497638

Efficient electrochemical refrigeration power plant using natural gas with ∼100% CO2 capture

NASA Astrophysics Data System (ADS)

Al-musleh, Easa I.; Mallapragada, Dharik S.; Agrawal, Rakesh

2015-01-01

We propose an efficient Natural Gas (NG) based Solid Oxide Fuel Cell (SOFC) power plant equipped with ∼100% CO2 capture. The power plant uses a unique refrigeration based process to capture and liquefy CO2 from the SOFC exhaust. The capture of CO2 is carried out via condensation and purification using two rectifying columns operating at different pressures. The uncondensed gas mixture, comprising of relatively high purity unconverted fuel, is recycled to the SOFC and found to boost the power generation of the SOFC by 22%, when compared to a stand alone SOFC. If Liquefied Natural Gas (LNG) is available at the plant gate, then the refrigeration available from its evaporation is used for CO2 Capture and Liquefaction (CO2CL). If NG is utilized, then a Mixed Refrigerant (MR) vapor compression cycle is utilized for CO2CL. Alternatively, the necessary refrigeration can be supplied by evaporating the captured liquid CO2 at a lower pressure, which is then compressed to supercritical pressures for pipeline transportation. From rigorous simulations, the power generation efficiency of the proposed processes is found to be 70-76% based on lower heating value (LHV). The benefit of the proposed processes is evident when the efficiency of 73% for a conventional SOFC-Gas turbine power plant without CO2 capture is compared with an equivalent efficiency of 71.2% for the proposed process with CO2CL.

ZnSe quantum dots modified with a Ni(cyclam) catalyst for efficient visible-light driven CO2 reduction in water.

PubMed

Kuehnel, Moritz F; Sahm, Constantin D; Neri, Gaia; Lee, Jonathan R; Orchard, Katherine L; Cowan, Alexander J; Reisner, Erwin

2018-03-07

A precious metal and Cd-free photocatalyst system for efficient CO 2 reduction in water is reported. The hybrid assembly consists of ligand-free ZnSe quantum dots (QDs) as a visible-light photosensitiser combined with a phosphonic acid-functionalised Ni(cyclam) catalyst, NiCycP. This precious metal-free photocatalyst system shows a high activity for aqueous CO 2 reduction to CO (Ni-based TON CO > 120), whereas an anchor-free catalyst, Ni(cyclam)Cl 2 , produced three times less CO. Additional ZnSe surface modification with 2-(dimethylamino)ethanethiol (MEDA) partially suppresses H 2 generation and enhances the CO production allowing for a Ni-based TON CO of > 280 and more than 33% selectivity for CO 2 reduction over H 2 evolution, after 20 h visible light irradiation ( λ > 400 nm, AM 1.5G, 1 sun). The external quantum efficiency of 3.4 ± 0.3% at 400 nm is comparable to state-of-the-art precious metal photocatalysts. Transient absorption spectroscopy showed that band-gap excitation of ZnSe QDs is followed by rapid hole scavenging and very fast electron trapping in ZnSe. The trapped electrons transfer to NiCycP on the ps timescale, explaining the high performance for photocatalytic CO 2 reduction. With this work we introduce ZnSe QDs as an inexpensive and efficient visible light-absorber for solar fuel generation.

Occupational carbon monoxide poisoning in Washington State, 2000-2005.

PubMed

Reeb-Whitaker, Carolyn K; Bonauto, David K; Whittaker, Stephen G; Adams, Darrin

2010-10-01

Washington State workers' compensation data can be used to guide prevention efforts focused on occupational carbon monoxide (CO) poisoning. Between 2000 and 2005, a total of 345 individual claims comprising 221 different exposure incidents were identified for the 6-year time period. The construction industry had 43 (20%) CO incidents, followed by wholesale trade with 32 (15%), and agriculture with 27 (12%) incidents. Fuel-powered forklifts caused 29% of all incidents, while autos/trucks/buses were responsible for 26%. The number of forklift incidents in fruit packing and cold storage companies declined significantly from 1994 through 2007 (Spearman's rho = 0.6659, p < 0.01). While this study used multiple medical records from workers' compensation claims to identify CO poisoning, a surveillance system that lacks extensive medical records may rely principally on carboxyhemoglobin (COHb) tests. This study demonstrated that 71% of the identified workers' compensation claims had associated COHb tests. The recurrence and timing of CO poisoning as well as control of the CO-generating source were determined. Approximately 8% of all work sites had recurring CO poisoning incidents. Two percent experienced a recurrent incident within 16 days of the initial incident, and 6% experienced a recurrent incident between 16 days and 3 years after the initial incident. Sixty-seven percent of claimants exposed to CO were not in direct control of the CO-generating source; this has implications for CO prevention and underscores the need for all employees to be trained on CO hazards.

Are renewables portfolio standards cost-effective emission abatement policy?

PubMed

Dobesova, Katerina; Apt, Jay; Lave, Lester B

2005-11-15

Renewables portfolio standards (RPS) could be an important policy instrument for 3P and 4P control. We examine the costs of renewable power, accounting for the federal production tax credit, the market value of a renewable credit, and the value of producing electricity without emissions of SO2, NOx, mercury, and CO2. We focus on Texas, which has a large RPS and is the largest U.S. electricity producer and one of the largest emitters of pollutants and CO2. We estimate the private and social costs of wind generation in an RPS compared with the current cost of fossil generation, accounting for the pollution and CO2 emissions. We find that society paid about 5.7 cent/kWh more for wind power, counting the additional generation, transmission, intermittency, and other costs. The higher cost includes credits amounting to 1.1 cent/kWh in reduced SO2, NOx, and Hg emissions. These pollution reductions and lower CO2 emissions could be attained at about the same cost using pulverized coal (PC) or natural gas combined cycle (NGCC) plants with carbon capture and sequestration (CCS); the reductions could be obtained more cheaply with an integrated coal gasification combined cycle (IGCC) plant with CCS.

Methyl green and nitrotetrazolium blue chloride co-expression in colon tissue: A hyperspectral microscopic imaging analysis

NASA Astrophysics Data System (ADS)

Li, Qingli; Liu, Hongying; Wang, Yiting; Sun, Zhen; Guo, Fangmin; Zhu, Jianzhong

2014-12-01

Histological observation of dual-stained colon sections is usually performed by visual observation under a light microscope, or by viewing on a computer screen with the assistance of image processing software in both research and clinical settings. These traditional methods are usually not sufficient to reliably differentiate spatially overlapping chromogens generated by different dyes. Hyperspectral microscopic imaging technology offers a solution for these constraints as the hyperspectral microscopic images contain information that allows differentiation between spatially co-located chromogens with similar but different spectra. In this paper, a hyperspectral microscopic imaging (HMI) system is used to identify methyl green and nitrotetrazolium blue chloride in dual-stained colon sections. Hyperspectral microscopic images are captured and the normalized score algorithm is proposed to identify the stains and generate the co-expression results. Experimental results show that the proposed normalized score algorithm can generate more accurate co-localization results than the spectral angle mapper algorithm. The hyperspectral microscopic imaging technology can enhance the visualization of dual-stained colon sections, improve the contrast and legibility of each stain using their spectral signatures, which is helpful for pathologist performing histological analyses.

Co-optimizing Generation and Transmission Expansion with Wind Power in Large-Scale Power Grids Implementation in the US Eastern Interconnection

DOE PAGES

You, Shutang; Hadley, Stanton W.; Shankar, Mallikarjun; ...

2016-01-12

This paper studies the generation and transmission expansion co-optimization problem with a high wind power penetration rate in the US Eastern Interconnection (EI) power grid. In this paper, the generation and transmission expansion problem for the EI system is modeled as a mixed-integer programming (MIP) problem. Our paper also analyzed a time series generation method to capture the variation and correlation of both load and wind power across regions. The obtained series can be easily introduced into the expansion planning problem and then solved through existing MIP solvers. Simulation results show that the proposed planning model and series generation methodmore » can improve the expansion result significantly through modeling more detailed information of wind and load variation among regions in the US EI system. Moreover, the improved expansion plan that combines generation and transmission will aid system planners and policy makers to maximize the social welfare in large-scale power grids.« less

Overlap corrections for emissivity calculations of H2O-CO2-CO-N2 mixtures

NASA Astrophysics Data System (ADS)

Alberti, Michael; Weber, Roman; Mancini, Marco

2018-01-01

Calculations of total gas emissivities of gas mixtures containing several radiatively active species require corrections for band overlapping. In this paper, we generate such overlap correction charts for H2O-CO2-N2, H2O-CO-N2, and CO2-CO-N2 mixtures. These charts are applicable in the 0.1-40 bar total pressure range and in the 500 K-2500 K temperature range. For H2O-CO2-N2 mixtures, differences between our charts and Hottel's graphs as well as models of Leckner and Modak are highlighted and analyzed.

Palladium-catalysed carbonylative α-arylation of nitromethane.

PubMed

Lian, Zhong; Friis, Stig D; Skrydstrup, Troels

2015-02-28

A simple and mild Pd-catalysed carbonylative α-arylation of nitromethane has been realised providing access to α-nitro aryl ketones from an array of aryl and heteroaryl iodides. The methodology requires only a mild base and uses the convenient solid CO releasing molecule, COgen in a two-chamber system. Changing to the isotopically labelled (13)COgen, [(13)C]-acyl labelling can be effected through the generation of a near stoichiometric amount of (13)CO. Lastly, the significance of the generated products as synthetic intermediates is demonstrated.

Regional hospital improves efficiency with co-generation retrofit.

PubMed

Knutson, D; Anderson, L

1999-11-01

Feasibility analysis of the co-generation retrofit of the Red Deer Regional Hospital pointed to a reasonable payback of capital cost and increased efficiency in operation of the facility. Budget restrictions nearly stopped the project from proceeding. Innovative construction procedures proposed by the Facility Management Group, in particular, Mr Keith Metcalfe, Director of Maintenance, allowed a worthwhile project to reach successful completion. We feel that this model can perhaps be used by similar facilities in the future to achieve their energy efficiency goals.

Detection of CO2•- in the Electrochemical Reduction of Carbon Dioxide in N,N-Dimethylformamide by Scanning Electrochemical Microscopy.

PubMed

Kai, Tianhan; Zhou, Min; Duan, Zhiyao; Henkelman, Graeme A; Bard, Allen J

2017-12-27

The electrocatalytic reduction of CO 2 has been studied extensively and produces a number of products. The initial reaction in the CO 2 reduction is often taken to be the 1e formation of the radical anion, CO 2 •- . However, the electrochemical detection and characterization of CO 2 •- is challenging because of the short lifetime of CO 2 •- , which can dimerize and react with proton donors and even mild oxidants. Here, we report the generation and quantitative determination of CO 2 •- in N,N-dimethylformamide (DMF) with the tip generation/substrate collection (TG/SC) mode of scanning electrochemical microscopy (SECM). CO 2 was reduced at a hemisphere-shaped Hg/Pt ultramicroelectrode (UME) or a Hg/Au film UME, which were utilized as the SECM tips. The CO 2 •- produced can either dimerize to form oxalate within the nanogap between SECM tip and substrate or collected at SECM substrate (e.g., an Au UME). The collection efficiency (CE) for CO 2 •- depends on the distance (d) between the tip and substrate. The dimerization rate (6.0 × 10 8 M -1 s -1 ) and half-life (10 ns) of CO 2 •- can be evaluated by fitting the collection efficiency vs distance curve. The dimerized species of CO 2 •- , oxalate, can also be determined quantitatively. Furthermore, the formal potential (E 0 ') and heterogeneous rate constant (k 0 ) for CO 2 reduction were determined with different quaternary ammonium electrolytes. The significant difference in k 0 is due to a tunneling effect caused by the adsorption of the electrolytes on the electrode surface at negative potentials.

Surface modification of CoCr alloy using varying concentrations of phosphoric and phosphonoacetic acids: albumin and fibrinogen adsorption, platelet adhesion, activation, and aggregation studies.

PubMed

Thiruppathi, Eagappanath; Larson, Mark K; Mani, Gopinath

2015-01-01

CoCr alloy is commonly used in various cardiovascular medical devices for its excellent physical and mechanical properties. However, the formation of blood clots on the alloy surfaces is a serious concern. This research is focused on the surface modification of CoCr alloy using varying concentrations (1, 25, 50, 75, and 100 mM) of phosphoric acid (PA) and phosphonoacetic acid (PAA) to generate various surfaces with different wettability, chemistry, and roughness. Then, the adsorption of blood plasma proteins such as albumin and fibrinogen and the adhesion, activation, and aggregation of platelets with the various surfaces generated were investigated. Contact angle analysis showed PA and PAA coatings on CoCr provided a gradient of hydrophilic surfaces. FTIR showed PA and PAA were covalently bound to CoCr surface and formed different bonding configurations depending on the concentrations of coating solutions used. AFM showed the formation of homogeneous PA and PAA coatings on CoCr. The single and dual protein adsorption studies showed that the amount of albumin and fibrinogen adsorbed on the alloy surfaces strongly depend on the type of PA and PAA coatings prepared by different concentrations of coating solutions. All PA coated CoCr showed reduced platelet adhesion and activation when compared to control CoCr. Also, 75 and 100 mM PA-CoCr showed reduced platelet aggregation. For PAA coated CoCr, no significant difference in platelet adhesion and activation was observed between PAA coated CoCr and control CoCr. Thus, this study demonstrated that CoCr can be surface modified using PA for potentially reducing the formation of blood clots and improving the blood compatibility of the alloy.

Graphene-Based Photocatalysts for Solar-Fuel Generation.

PubMed

Xiang, Quanjun; Cheng, Bei; Yu, Jiaguo

2015-09-21

The production of solar fuel through photocatalytic water splitting and CO2 reduction using photocatalysts has attracted considerable attention owing to the global energy shortage and growing environmental problems. During the past few years, many studies have demonstrated that graphene can markedly enhance the efficiency of photocatalysts for solar-fuel generation because of its unique 2D conjugated structure and electronic properties. Herein we summarize the recent advances in the application of graphene-based photocatalysts for solar-fuel production, including CO2 reduction to hydrocarbon fuel and water splitting to H2. A brief overview of the fundamental principles for splitting of water and reduction of CO2 is given. The different roles of graphene in these graphene-based photocatalysts for improving photocatalytic performance are discussed. Finally, the perspectives on the challenges and opportunities for future research in this promising area are also presented. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Metal adatoms generated by the co-play of melamine assembly and subsequent CO adsorption.

PubMed

Wang, Li; Chen, Qiwei; Shi, Hong; Liu, Huihui; Ren, Xinguo; Wang, Bing; Wu, Kai; Shao, Xiang

2016-01-28

Molecular self-assembly films are expected to tailor the surface process by the periodic nanostructures and add-on functional groups. In this work, a molecular network of melamine with featured pores of subnanometer size is prepared on the Au(111) surface, and is found to be able to trap the gold adatoms and concomitant single vacancies generated under the impingement of CO molecules at room temperature. DFT calculations suggest that the strong CO-Au adatom interaction as well as the high adhesion of the Au adatom inside the melamine pore could well be the driving force behind such process. This study not only sheds light onto the interactions between gasses and the metal surface that is covered by molecular self-assembly films, but also provides a novel route to manipulate the monoatomic surface species which is of catalytic interest.

High-flux solar-driven thermochemical dissociation of CO2 and H2O using nonstoichiometric ceria.

PubMed

Chueh, William C; Falter, Christoph; Abbott, Mandy; Scipio, Danien; Furler, Philipp; Haile, Sossina M; Steinfeld, Aldo

2010-12-24

Because solar energy is available in large excess relative to current rates of energy consumption, effective conversion of this renewable yet intermittent resource into a transportable and dispatchable chemical fuel may ensure the goal of a sustainable energy future. However, low conversion efficiencies, particularly with CO(2) reduction, as well as utilization of precious materials have limited the practical generation of solar fuels. By using a solar cavity-receiver reactor, we combined the oxygen uptake and release capacity of cerium oxide and facile catalysis at elevated temperatures to thermochemically dissociate CO(2) and H(2)O, yielding CO and H(2), respectively. Stable and rapid generation of fuel was demonstrated over 500 cycles. Solar-to-fuel efficiencies of 0.7 to 0.8% were achieved and shown to be largely limited by the system scale and design rather than by chemistry.

Two Storm-Related Carbon Monoxide Poisoning Outbreaks—Connecticut, October 2011 and October 2012

PubMed Central

STYLES, TIMOTHY; PRZYSIECKI, PATRICIA; ARCHAMBAULT, GARY; SOSA, LYNN; TOAL, BRIAN; MAGRI, JULIE; CARTTER, MATTHEW

2015-01-01

Storm-related carbon monoxide (CO) poisoning outbreaks occurred in Connecticut in 2011 and 2012, despite efforts to improve public messaging. We describe the cases and incidents and identify possible preventive interventions. We defined cases as blood carboxyhemoglobin ≥9.0% among persons exposed to alternative power or heat sources because of storm-related losses. We identified 133 cases, including 3 deaths, in 2011 and 30 in 2012, associated with 72 and 11 incidents, respectively. Racial/ethnic minorities were overrepresented (60% of 2011 patients; 48% in 2012), compared with Connecticut’s minority population (29%). Generator or charcoal misuse (83% in 2011; 100% in 2012) caused the majority of incidents. Few CO-source operators recalled media or product CO warnings. Incorrect generator and charcoal use, racial/ethnic disparities, and incomplete penetration of warning messages characterized both outbreaks. A multifaceted approach is needed to decrease postdisaster CO poisonings. PMID:24971904

Measurement simulation of spatial coherence and density degree by turbulence of aerosol and CO II in atmospheric environment

NASA Astrophysics Data System (ADS)

Okayama, Hiroshi; Li, Wei

2006-09-01

Atmopheric turbulence is one of the important correction factors to evaluate the earth's surface using a sinsor on a satellite. CO II and aerosol are selected as factors of turbulence. The effects of turbulence caused by CO II and aerosol on the light reflected from the earth's surface are estimated by measuring the degradation of spatial coherence of light in a chamber in which atmospheric turbulence is generated. Dry ice is used to generate carbon dioxide gas. degradation of spatial coherence is measured in relation to the increase of CO II. Turbulence caused by aerosol is measured by density of smoke cigarettes. The spatial coherence of light in the chamber degrades in relation to the increase of aerosol and as a result the turbulence increases. The relation between the turbulence and the degree of spatial coherence is explained in a formula.

An experimental study of reactive turbulent mixing

NASA Technical Reports Server (NTRS)

Cooper, L. P.; Marek, C. J.; Strehlow, R. A.

1977-01-01

An experimental study of two coaxial gas streams, which react very rapidly, was performed to investigate the mixing characteristics of turbulent flow fields. The center stream consisted of a CO-N2 mixture and the outer annular stream consisted of air vitiated by H2 combustion. The streams were at equal velocity (50 m/sec) and temperature (1280 K). Turbulence measurements were obtained using hot film anemometry. A sampling probe was used to obtain time averaged gas compositions. Six different turbulence generators were placed in the annular passage to alter the flow field mixing characteristics. The turbulence generators affected the bulk mixing of the streams and the extent of CO conversion to different degrees. The effects can be related to the average eddy size (integral scale) and the bulk mixing. Higher extents of conversion of CO to CO2 were found be increasing the bulk mixing and decreasing the average eddy size.

A multiscale and multidisciplinary investigation of ecosystem-atmosphere CO2 exchange over the rocky mountains of colorado

USGS Publications Warehouse

Sun, Jielun; Oncley, S.P.; Burns, Sean P.; Stephens, B.B.; Lenschow, D.H.; Campos, T.; Monson, Russell K.; Schimel, D.S.; Sacks, W.J.; De Wekker, S. F. J.; Lai, C.-T.; Lamb, B.; Ojima, D.; Ellsworth, P.Z.; Sternberg, L.S.L.; Zhong, S.; Clements, C.; Moore, D.J.P.; Anderson, D.E.; Watt, A.S.; Hu, Jiawen; Tschudi, M.; Aulenbach, S.; Allwine, E.; Coons, T.

2010-01-01

A field study combined with modeling investigation demonstrated that the organization of CO2 transport by mountain terrain strongly affects the regional CO2 budget. Atmospheric dynamics can lead to complicated flows generated by inhomogeneous landscapes, topography or synoptic weather systems. The field campaign conducted of a ground deployment, the Carbon in the Mountain Experiment (CME04), and an aircraft deployment of the national Center for Atmospheric Research (NCAR) C-130, the Airborne Carbon in the Mountains Experiment (ACME04) over the period of spring to fall of 2004 to cover the seasonal variation of ecosystem-atmosphere carbon exchange. The role of the mountain circulation in CO2 transport can be played over seemingly flat terrain by mesoscale flows generated by various physical processes. The three dimensional observation strategy considered can also be applied over flat terrain.

Protection of rat skeletal muscle fibers by either L-carnitine or coenzyme Q10 against statins toxicity mediated by mitochondrial reactive oxygen generation

PubMed Central

La Guardia, P. G.; Alberici, L. C.; Ravagnani, F. G.; Catharino, R. R.; Vercesi, A. E.

2013-01-01

Mitochondrial redox imbalance has been implicated in mechanisms of aging, various degenerative diseases and drug-induced toxicity. Statins are safe and well-tolerated therapeutic drugs that occasionally induce myotoxicity such as myopathy and rhabdomyolysis. Previous studies indicate that myotoxicity caused by statins may be linked to impairment of mitochondrial functions. Here, we report that 1-h incubation of permeabilized rat soleus muscle fiber biopsies with increasing concentrations of simvastatin (1–40 μM) slowed the rates of ADP-or FCCP-stimulated respiration supported by glutamate/malate in a dose-dependent manner, but caused no changes in resting respiration rates. Simvastatin (1 μM) also inhibited the ADP-stimulated mitochondrial respiration supported by succinate by 24% but not by TMPD/ascorbate. Compatible with inhibition of respiration, 1 μM simvastatin stimulated lactate release from soleus muscle samples by 26%. Co-incubation of muscle samples with 1 mM L-carnitine, 100 μM mevalonate or 10 μM coenzyme Q10 (Co-Q10) abolished simvastatin effects on both mitochondrial glutamate/malate-supported respiration and lactate release. Simvastatin (1 μM) also caused a 2-fold increase in the rate of hydrogen peroxide generation and a decrease in Co-Q10 content by 44%. Mevalonate, Co-Q10 or L-carnitine protected against stimulation of hydrogen peroxide generation but only mevalonate prevented the decrease in Co-Q10 content. Thus, independently of Co-Q10 levels, L-carnitine prevented the toxic effects of simvastatin. This suggests that mitochondrial respiratory dysfunction induced by simvastatin, is associated with increased generation of superoxide, at the levels of complexes-I and II of the respiratory chain. In all cases the damage to these complexes, presumably at the level of 4Fe-4S clusters, is prevented by L-carnitine. PMID:23720630

Cost and greenhouse gas emission tradeoffs of alternative uses of lignin for second generation ethanol

NASA Astrophysics Data System (ADS)

Pourhashem, Ghasideh; Adler, Paul R.; McAloon, Andrew J.; Spatari, Sabrina

2013-06-01

Second generation ethanol bioconversion technologies are under demonstration-scale development for the production of lignocellulosic fuels to meet the US federal Renewable Fuel Standards (RFS2). Bioconversion technology utilizes the fermentable sugars generated from the cellulosic fraction of the feedstock, and most commonly assumes that the lignin fraction may be used as a source of thermal and electrical energy. We examine the life cycle greenhouse gas (GHG) emission and techno-economic cost tradeoffs for alternative uses of the lignin fraction of agricultural residues (corn stover, and wheat and barley straw) produced within a 2000 dry metric ton per day ethanol biorefinery in three locations in the United States. We compare three scenarios in which the lignin is (1) used as a land amendment to replace soil organic carbon (SOC); (2) separated, dried and sold as a coal substitute to produce electricity; and (3) used to produce electricity onsite at the biorefinery. Results from this analysis indicate that for life cycle GHG intensity, amending the lignin to land is lowest among the three ethanol production options (-25 to -2 g CO2e MJ-1), substituting coal with lignin is second lowest (4-32 g CO2e MJ-1), and onsite power generation is highest (36-41 g CO2e MJ-1). Moreover, the onsite power generation case may not meet RFS2 cellulosic fuel requirements given the uncertainty in electricity substitution. Options that use lignin for energy do so at the expense of SOC loss. The lignin-land amendment option has the lowest capital cost among the three options due to lower equipment costs for the biorefinery’s thermal energy needs and use of biogas generated onsite. The need to purchase electricity and uncertain market value of the lignin-land amendment could raise its cost compared to onsite power generation and electricity co-production. However, assuming a market value (50-100/dry Mg) for nutrient and soil carbon replacement in agricultural soils, and potentially economy of scale residue collection prices at higher collection volumes associated with low SOC loss, the lignin-land amendment option is economically and environmentally preferable, with the lowest GHG abatement costs relative to gasoline among the three lignin co-product options we consider.

Mechanical and electrochemical response of a LiCoO 2 cathode using reconstructed microstructures

DOE PAGES

Mendoza, Hector; Roberts, Scott Alan; Brunini, Victor; ...

2016-01-01

As LiCoO 2 cathodes are charged, delithiation of the LiCoO 2 active material leads to an increase in the lattice spacing, causing swelling of the particles. When these particles are packed into a bicontinuous, percolated network, as is the case in a battery electrode, this swelling leads to the generation of significant mechanical stress. In this study we performed coupled electrochemical-mechanical simulations of the charging of a LiCoO 2 cathode in order to elucidate the mechanisms of stress generation and the effect of charge rate and microstructure on these stresses. Energy dispersive spectroscopy combined with scanning electron microscopy imaging wasmore » used to create 3D reconstructions of a LiCoO 2 cathode, and the Conformal Decomposition Finite Element Method is used to automatically generate computational meshes on this reconstructed microstructure. Replacement of the ideal solution Fickian diffusion model, typically used in battery simulations, with a more general non-ideal solution model shows substantially smaller gradients of lithium within particles than is typically observed in the literature. Using this more general model, lithium gradients only appear at states of charge where the open-circuit voltage is relatively constant. While lithium gradients do affect the mechanical stress state in the particles, the maximum stresses are always found in the fully-charged state and are strongly affected by the local details of the microstructure and particle-to-particle contacts. These coupled electrochemical-mechanical simulations begin to yield insight into the partitioning of volume change between reducing pore space and macroscopically swelling the electrode. Lastly, preliminary studies that include the presence of the polymeric binder suggest that it can greatly impact stress generation and that it is an important area for future research.« less

PdO Doping Tunes Band-Gap Energy Levels as Well as Oxidative Stress Responses to a Co3O4p-Type Semiconductor in Cells and the Lung

PubMed Central

2014-01-01

We demonstrate through PdO doping that creation of heterojunctions on Co3O4 nanoparticles can quantitatively adjust band-gap and Fermi energy levels to study the impact of metal oxide nanoparticle semiconductor properties on cellular redox homeostasis and hazard potential. Flame spray pyrolysis (FSP) was used to synthesize a nanoparticle library in which the gradual increase in the PdO content (0–8.9%) allowed electron transfer from Co3O4 to PdO to align Fermi energy levels across the heterojunctions. This alignment was accompanied by free hole accumulation at the Co3O4 interface and production of hydroxyl radicals. Interestingly, there was no concomitant superoxide generation, which could reflect the hole dominance of a p-type semiconductor. Although the electron flux across the heterojunctions induced upward band bending, the Ec levels of the doped particles showed energy overlap with the biological redox potential (BRP). This allows electron capture from the redox couples that maintain the BRP from −4.12 to −4.84 eV, causing disruption of cellular redox homeostasis and induction of oxidative stress. PdO/Co3O4 nanoparticles showed significant increases in cytotoxicity at 25, 50, 100, and 200 μg/mL, which was enhanced incrementally by PdO doping in BEAS-2B and RAW 264.7 cells. Oxidative stress presented as a tiered cellular response involving superoxide generation, glutathione depletion, cytokine production, and cytotoxicity in epithelial and macrophage cell lines. A progressive series of acute pro-inflammatory effects could also be seen in the lungs of animals exposed to incremental PdO-doped particles. All considered, generation of a combinatorial PdO/Co3O4 nanoparticle library with incremental heterojunction density allowed us to demonstrate the integrated role of Ev, Ec, and Ef levels in the generation of oxidant injury and inflammation by the p-type semiconductor, Co3O4. PMID:24673286

40 CFR 53.22 - Generation of test atmospheres.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 6 2012-07-01 2012-07-01 false Generation of test atmospheres. 53.22... Characteristics of Automated Methods for SO2, CO, O3, and NO2 § 53.22 Generation of test atmospheres. (a) Table B-2 to subpart B of part 53 specifies preferred methods for generating test atmospheres and suggested...

40 CFR 53.22 - Generation of test atmospheres.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Generation of test atmospheres. 53.22... Characteristics of Automated Methods for SO2, CO, O3, and NO2 § 53.22 Generation of test atmospheres. (a) Table B-2 to subpart B of part 53 specifies preferred methods for generating test atmospheres and suggested...

40 CFR 53.22 - Generation of test atmospheres.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Generation of test atmospheres. 53.22... Characteristics of Automated Methods for SO2, CO, O3, and NO2 § 53.22 Generation of test atmospheres. (a) Table B-2 to subpart B of part 53 specifies preferred methods for generating test atmospheres and suggested...

Method of CO.sub.2 removal from a gasesous stream at reduced temperature

DOEpatents

Fisher, James C; Siriwardane, Ranjani V; Berry, David A; Richards, George A

2014-11-18

A method for the removal of H.sub.2O and CO.sub.2 from a gaseous stream comprising H.sub.2O and CO.sub.2, such as a flue gas. The method initially utilizes an H.sub.2O removal sorbent to remove some portion of the H.sub.2O, producing a dry gaseous stream and a wet H.sub.2O removal sorbent. The dry gaseous stream is subsequently contacted with a CO.sub.2 removal sorbent to remove some portion of the CO.sub.2, generating a dry CO.sub.2 reduced stream and a loaded CO.sub.2 removal sorbent. The loaded CO.sub.2 removal sorbent is subsequently heated to produce a heated CO.sub.2 stream. The wet H.sub.2O removal sorbent and the dry CO.sub.2 reduced stream are contacted in a first regeneration stage, generating a partially regenerated H.sub.2O removal sorbent, and the partially regenerated H.sub.2O removal sorbent and the heated CO.sub.2 stream are subsequently contacted in a second regeneration stage. The first and second stage regeneration typically act to retain an initial monolayer of moisture on the various removal sorbents and only remove moisture layers bound to the initial monolayer, allowing for relatively low temperature and pressure operation. Generally the applicable H.sub.2O sorption/desorption processes may be conducted at temperatures less than about 70.degree. C. and pressures less than 1.5 atmospheres, with certain operations conducted at temperatures less than about 50.degree. C.

Anaerobic co-digestion of dairy manure and potato waste

NASA Astrophysics Data System (ADS)

Yadanaparthi, Sai Krishna Reddy

Dairy and potato are two important agricultural commodities in Idaho. Both the dairy and potato processing industries produce a huge amount of waste which could cause environmental pollution. To minimize the impact of potential pollution associated with dairy manure (DM) and potato waste (PW), anaerobic co-digestion has been considered as one of the best treatment process. The purpose of this research is to evaluate the anaerobic co-digestion of dairy manure and potato waste in terms of process stability, biogas generation, construction and operating costs, and potential revenue. For this purpose, I conducted 1) a literature review, 2) a lab study on anaerobic co-digestion of dairy manure and potato waste at three different temperature ranges (ambient (20-25°C), mesophilic (35-37°C) and thermophilic (55-57°C) with five mixing ratios (DM:PW-100:0, 90:10, 80:20, 60:40, 40:60), and 3) a financial analysis for anaerobic digesters based on assumed different capital costs and the results from the lab co-digestion study. The literature review indicates that several types of organic waste were co-digested with DM. Dairy manure is a suitable base matter for the co-digestion process in terms of digestion process stability and methane (CH4) production (Chapter 2). The lab tests showed that co-digestion of DM with PW was better than digestion of DM alone in terms of biogas and CH4 productions (Chapter 3). The financial analysis reveals DM and PW can be used as substrate for full size anaerobic digesters to generate positive cash flow within a ten year time period. Based on this research, the following conclusions and recommendations were made: ▸ The ratio of DM:PW-80:20 is recommended at thermophilic temperatures and the ratio of DM:PW-90:10 was recommended at mesophilic temperatures for optimum biogas and CH4 productions. ▸ In cases of anaerobic digesters operated with electricity generation equipment (generators), low cost plug flow digesters (capital cost of 600/cow) operating at thermophilic temperatures are recommended. • The ratio of DM:PW-90:10 or 80:20 is recommended while operating low cost plug flow digesters at thermophilic temperatures. ▸ In cases of anaerobic digesters operated without electricity generation equipment (generators), completely mixed or high or low cost plug flow digesters can be used. • The ratio of DM:PW-80:20 is recommended for completely mixed digesters operated at thermophilic temperatures; • The ratio of DM:PW-90:10 or 80:20 is recommended for high cost plug flow digesters (capital cost of 1,000/cow) operated at thermophilic temperatures; • All of the four co-digested mixing ratios (i.e. DM:PW-90:10 or 80:20 or 60:40 or 40:60) are good for low cost plug flow digesters (capital cost of $600/cow) operated at thermophilic temperatures. The ratio of DM:PW-90:10 is recommended for positive cash flow within the ten year period if the low cost plug flow digesters are operated at mesophilic temperatures.

Oxygen Generation from Carbon Dioxide for Advanced Life Support

NASA Technical Reports Server (NTRS)

Bishop, s. R.; Duncan, K. L.; Hagelin-Weaver, H. E.; Neal, L.; Paul, H. L.; Wachsman, E. D.

2007-01-01

The partial electrochemical reduction of CO2 using ceramic oxygen generators (COGs) is well known and has been studied. Conventional COGs use yttria-stabilized zirconia (YSZ) electrolytes and operate at temperatures greater than 700 C (1, 2). Operating at a lower temperature has the advantage of reducing the mass of the ancillary components such as insulation. Moreover, complete reduction of metabolically produced CO2 (into carbon and oxygen) has the potential of reducing oxygen storage weight if the oxygen can be recovered. Recently, the University of Florida developed ceramic oxygen generators employing a bilayer electrolyte of gadolinia-doped ceria and erbia-stabilized bismuth oxide (ESB) for NASA s future exploration of Mars (3). The results showed that oxygen could be reliably produced from CO2 at temperatures as low as 400 C. These results indicate that this technology could be adapted to CO2 removal from a spacesuit and other applications in which CO2 removal is an issue. This strategy for CO2 removal in advanced life support systems employs a catalytic layer combined with a COG so that the CO2 is reduced completely to solid carbon and oxygen. First, to reduce the COG operating temperature, a thin, bilayer electrolyte was employed. Second, to promote full CO2 reduction while avoiding the problem of carbon deposition on the COG cathode, a catalytic carbon deposition layer was designed and the cathode utilized materials shown to be coke resistant. Third, a composite anode was used consisting of bismuth ruthenate (BRO) and ESB that has been shown to have high performance (4). The inset of figure 1 shows the conceptual design of the tubular COG and the rest of the figure shows schematically the test apparatus. Figure 2 shows the microstructure of a COG tube prior to testing. During testing, current is applied across the cell and initially CuO is reduced to copper metal by electrochemical pumping. Then the oxygen source becomes the CO/CO2. This presentation details the results of testing the COG.

Evolution of Abnormally Low Pressure at Bravo Dome and its Implications for Carbon Capture and Storage (CCS)

NASA Astrophysics Data System (ADS)

Akhbari, D.; Hesse, M. A.

2015-12-01

Carbon capture and storage allows reductions of the rapidly rising CO2 from fossil fuel-based power generation, if large storage rates and capacities can be achieved. The injection of large fluid volumes at high rates leads to a build-up of pore-pressure in the storage formation that may induce seismicity and compromise the storage security. Many natural CO2 fields in midcontinent US, in contrast, are under-pressured rather than over-pressured suggesting that natural processes reduce initial over-pressures and generate significant under-pressures. The question is therefore to understand the sequence of process(es) that allow the initial over-pressure to be eliminated and the under-pressure to be maintained over geological periods of time. We therefore look into pressure evolution in Bravo Dome, one of the largest natural CO2 accumulations in North America, which stores 1.3 Gt of CO2. Bravo Dome is only 580-900 m deep and is divided into several compartments with near gas-static pressure (see Figure). The pre-production gas pressures in the two main compartments that account for 70% of the mass of CO2 stored at Bravo Dome are more than 6 MPa below hydrostatic pressure. Here we show that the under-pressure in the Bravo Dome CO2 reservoir is maintained by hydrological compartmentalization over millennial timescales and generated by a combination of processes including cooling, erosional unloading, limited leakage into overlying formations, and CO2 dissolution into brine. Herein, we introduce CO2 dissolution into brine as a new process that reduce gas pressure in a compartmentalized reservoir and our results suggest that it may contribute significantly to reduce the initial pressure build-up due to injection. Bravo Dome is the first documented case of pressure drop due to CO2 dissolution. To have an accurate prediction of pressure evolution in Bravo Dome, our models must include geomechanics and thermodynamics for the reservoir while they account for the pressure changes due to the CO2 dissolution.

"Supergreen" Renewables: Integration of Mineral Weathering Into Renewable Energy Production for Air CO2 Removal and Storage as Ocean Alkalinity

NASA Astrophysics Data System (ADS)

Rau, G. H.; Carroll, S.; Ren, Z. J.

2015-12-01

Excess planetary CO2 and accompanying ocean acidification are naturally mitigated on geologic time scales via mineral weathering. Here, CO2 acidifies the hydrosphere, which then slowly reacts with silicate and carbonate minerals to produce dissolved bicarbonates that are ultimately delivered to the ocean. This alkalinity not only provides long-term sequestration of the excess atmospheric carbon, but it also chemically counters the effects of ocean acidification by stabilizing or raising pH and carbonate saturation state, thus helping rebalance ocean chemistry and preserving marine ecosystems. Recent research has demonstrated ways of greatly accelerating this process by its integration into energy systems. Specifically, it has been shown (1) that some 80% of the CO2 in a waste gas stream can be spontaneously converted to stable, seawater mineral bicarbonate in the presence of a common carbonate mineral - limestone. This can allow removal of CO2 from biomass combustion and bio-energy production while generating beneficial ocean alkalinity, providing a potentially cheaper and more environmentally friendly negative-CO2-emissions alternative to BECCS. It has also been demonstrated that strong acids anodically produced in a standard saline water electrolysis cell in the formation of H2 can be reacted with carbonate or silicate minerals to generate strong base solutions. These solutions are highly absorptive of air CO2, converting it to mineral bicarbonate in solution. When such electrochemical cells are powered by non-fossil energy (e.g. electricity from wind, solar, tidal, biomass, geothermal, etc. energy sources), the system generates H2 that is strongly CO2-emissions-negative, while producing beneficial marine alkalinity (2-4). The preceding systems therefore point the way toward renewable energy production that, when tightly coupled to geochemical mitigation of CO2 and formation of natural ocean "antacids", forms a high capacity, negative-CO2-emissions, "supergreen" source of fuel or electrcity. 1) http://pubs.acs.org/doi/pdf/10.1021/es102671x2) http://pubs.acs.org/doi/full/10.1021/es800366q3) http://www.pnas.org/content/110/25/10095.full.pdf4) http://pubs.acs.org/doi/abs/10.1021/acs.est.5b00875

Considering the Role of Natural Gas in the Deep Decarbonization of the U.S. Electricity Sector. Natural Gas and the Evolving U.S. Power Sector Monograph Series: Number 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cole, Wesley; Beppler, Ross; Zinaman, Owen

Natural gas generation in the U.S. electricity sector has grown substantially in recent years, while the sector's carbon dioxide (CO2) emissions have generally declined. This relationship highlights the concept of natural gas as a potential enabler of a transition to a lower-carbon future. This work considers that concept by using the National Renewable Energy Laboratory (NREL) Renewable Energy Deployment System (ReEDS) model. ReEDS is a long-term capacity expansion model of the U.S. electricity sector. We examine the role of natural gas within the ReEDS modeling framework as increasingly strict carbon emission targets are imposed on the electricity sector. In additionmore » to various natural gas price futures, we also consider scenarios that emphasize a low-carbon technology in order to better understand the role of natural gas if that low-carbon technology shows particular promise. Specifically, we consider scenarios with high amounts of energy efficiency (EE), low nuclear power costs, low renewable energy (RE) costs, and low carbon capture and storage (CCS) costs. Within these scenarios we find that requiring the electricity sector to lower CO2 emissions over time increases near-to-mid-term (through 2030) natural gas generation (see Figure 1 - left). The long-term (2050) role of natural gas generation in the electricity sector is dependent on the level of CO2 emission reduction required. Moderate reductions in long-term CO2 emissions have relatively little impact on long-term natural gas generation, while more stringent CO2 emission limits lower long-term natural gas generation (see Figure 1 - right). More stringent carbon targets also impact other generating technologies, with the scenarios considered here seeing significant decreases in coal generation, and new capacity of nuclear and renewable energy technologies over time. Figure 1 also demonstrates the role of natural gas in the context of scenarios where a specific low-carbon technology is advantaged. In 2030, natural gas generation in the technology scenarios is quite similar to that in the reference scenarios, indicating relatively little change in the role of natural gas in the near-to-mid-term due to advancements in those technology areas. The 2050 natural gas generation shows more significant differences, suggesting that technology advancements will likely have substantial impacts on the role of natural gas in the longer-term timeframe. Natural gas generation differences are most strongly driven by alternative natural gas price trajectories--changes in natural gas generation in the Low NG Price and High NG Price scenarios are much larger than in any other scenario in both the 2030 and 2050 timeframes. The only low-carbon technology scenarios that showed any increase in long-term natural gas generation relative to the reference case were the Low CCS cost scenarios. Carbon capture and storage technology costs are currently high, but have the potential to allow fossil fuels to play a larger role in low-carbon grid. This work considers three CCS cost trajectories for natural gas and coal generators: a baseline trajectory and two lower cost trajectories where CO2 capture costs reach $40/metric ton and $10/metric ton, respectively. We find that in the context of the ReEDS model and with these assumed cost trajectories, CCS can increase the long-term natural gas generation under a low carbon target (see Figure 2). Under less stringent carbon targets we do not see ReEDS electing to use CCS as part of its electricity generating portfolio for the scenarios considered in this work.« less

77 FR 15142 - Sunshine Federal Register Notice

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-14

.... Luminant Generation Company LLC (Comanche Peak Nuclear Power Plant, Units 3 and 4); Energy Northwest (Columbia Generating Station); Southern Nuclear Operating Co. (Vogtle Electric Generating Plant, Units 3 and... subscribers. If you no longer wish to receive it, or would like to be added to the distribution, please...

THE SECOND GENERATION OF THE WASTE REDUCTION (WAR) ALGORITHM: A DECISION SUPPORT SYSTEM FOR GREENER CHEMICAL PROCESSES

EPA Science Inventory

chemical process designers using simulation software generate alternative designs for one process. One criterion for evaluating these designs is their potential for adverse environmental impacts due to waste generated, energy consumed, and possibilities for fugitive emissions. Co...

(abstract) Monitoring Seasonal State and Mapping Species in Alaskan Taiga Using Imaging Radar as Input to CO(sub 2) Flux Models

NASA Technical Reports Server (NTRS)

Way, J. B.; Rignot, E.; McDonald, K.; Adams, P.; Viereck, L.

1993-01-01

Changes in the seasonal CO(sub 2) flux of the boreal forests may result from increased atmospheric CO(sub 2) concentrations and associated atmospheric warming. To monitor this potential change, a combination of remote sensing information and ecophysiological models are required. In this paper we address the use of synthetic aperture radar (SAR) data to provide some of the input to the ecophysiological models: forest type, freeze/thaw state which limits the growing season for conifers, and leaf on/off state which limits the growing season for deciduous species. AIRSAR data collected in March 1988 during an early thaw event and May 1991 during spring breakup are used to generate species maps and to determine the sensitivity of SAR to canopy freeze/thaw transitions. These data are also used to validate a microwave scattering model which is then used to determine the sensitivity of SAR to leaf on/off and soil freeze/thaw transitions. Finally, a CO(sub 2) flux algorithm which utilizes SAR data and an ecophysiological model to estimate CO(sub 2) flux is presented. CO(sub 2) flux maps are generated from which areal estimates of CO(sub 2) flux are derived.

Vectors for co-expression of an unrestricted number of proteins

PubMed Central

Scheich, Christoph; Kümmel, Daniel; Soumailakakis, Dimitri; Heinemann, Udo; Büssow, Konrad

2007-01-01

A vector system is presented that allows generation of E. coli co-expression clones by a standardized, robust cloning procedure. The number of co-expressed proteins is not limited. Five ‘pQLink’ vectors for expression of His-tag and GST-tag fusion proteins as well as untagged proteins and for cloning by restriction enzymes or Gateway cloning were generated. The vectors allow proteins to be expressed individually; to achieve co-expression, two pQLink plasmids are combined by ligation-independent cloning. pQLink co-expression plasmids can accept an unrestricted number of genes. As an example, the co-expression of a heterotetrameric human transport protein particle (TRAPP) complex from a single plasmid, its isolation and analysis of its stoichiometry are shown. pQLink clones can be used directly for pull-down experiments if the proteins are expressed with different tags. We demonstrate pull-down experiments of human valosin-containing protein (VCP) with fragments of the autocrine motility factor receptor (AMFR). The cloning method avoids PCR or gel isolation of restriction fragments, and a single resistance marker and origin of replication are used, allowing over-expression of rare tRNAs from a second plasmid. It is expected that applications are not restricted to bacteria, but could include co-expression in other hosts such as Bacluovirus/insect cells. PMID:17311810

Breath ethane as a marker of reactive oxygen species during manipulation of diet and oxygen tension in rats.

PubMed

Risby, T H; Jiang, L; Stoll, S; Ingram, D; Spangler, E; Heim, J; Cutler, R; Roth, G S; Rifkind, J M

1999-02-01

Breath ethane, O2 consumption, and CO2 production were analyzed in 24-mo-old female Fischer 344 rats that had been fed continuously ad libitum (AL) or restricted 30% of AL level (DR) diets since 6 wk of age. Rats were placed in a glass chamber that was first flushed with air, then with a gas mixture containing 12% O2. After equilibration, a sample of the outflow was collected in gas sampling bags for subsequent analyses of ethane and CO2. The O2 and CO2 levels were also directly monitored in the outflow of the chamber. O2 consumption and CO2 production increased for DR rats. Hypoxia decreased O2 consumption and CO2 production for the AL-fed and DR rats. These changes reflect changes in metabolic rate due to diet and PO2. A significant decrease in ethane generation was found in DR rats compared with AL-fed rats. Under normoxic conditions, breath ethane decreased from 2.20 to 1.61 pmol ethane/ml CO2. During hypoxia the levels of ethane generation increased, resulting in a DR-associated decrease in ethane from 2.60 to 1.90 pmol ethane/ml CO2. These results support the hypothesis that DR reduces the level of oxidative stress.

Recent operating experiences with steam generators in Japanese NPPs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yashima, Seiji

1997-02-01

In 1994, the Genkai-3 of Kyushu Electric Power Co., Inc. and the Ikata-3 of Shikoku Electric Power Co., Inc. started commercial operation, and now 22 PWR plants are being operated in Japan. Since the first PWR plant now 22 PWR plants are being operated in was started to operate, Japanese PWR plants have had an operating experience of approx. 280 reactor-years. During that period, many tube degradations have been experienced in steam generators (SGs). And, in 1991, the steam generator tube rupture (SGTR) occurred in the Mihama-2 of Kansai Electric Power Co., Inc. However, the occurrence of tube degradation ofmore » SGs has been decreased by the instructions of the MITI as regulatory authorities, efforts of Electric Utilities, and technical support from the SG manufacturers. Here the author describes the recent SGs in Japan about the following points. (1) Recent Operating Experiences (2) Lessons learned from Mihama-2 SGTR (3) SG replacement (4) Safety Regulations on SG (5) Research and development on SG.« less

Updated (BP3) Technical and Economic Feasibility Study - Electrochemical Membrane for Carbon Dioxide Capture and Power Generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghezel-Ayagh, Hossein

This topical report summarizes the results of an updated Technical & Economic Feasibility Study (T&EFS) which was conducted in Budget Period 3 of the project to evaluate the performance and cost of the Electrochemical Membrane (ECM)-based CO 2 capture system. The ECM technology is derived from commercially available inorganic membranes; the same used in FuelCell Energy’s commercial fuel cell power plants and sold under the trade name Direct FuelCell® (DFC®). The ECM stacks are utilized in the Combined Electric Power (generation) And Carbon dioxide Separation (CEPACS) systems which can be deployed as add-ons to conventional power plants (Pulverized Coal, Combinedmore » Cycle, etc.) or industrial facilities to simultaneously produce power while capturing >90% of the CO 2 from the flue gas. In this study, an ECM-based CEPACS plant was designed to capture and compress >90% of the CO 2 (for sequestration or beneficial use) from the flue gas of a reference 550 MW (nominal, net AC) Pulverized Coal (PC) Rankine Cycle (Subcritical steam) power plant. ECM performance was updated based on bench scale ECM stack test results. The system process simulations were performed to generate the CEPACS plant performance estimates. The performance assessment included estimation of the parasitic power consumption for CO 2 capture and compression, and the efficiency impact on the PC plant. While the ECM-based CEPACS system for the 550 MW PC plant captures 90% of CO 2 from the flue gas, it generates additional (net AC) power after compensating for the auxiliary power requirements of CO 2 capture and compression. An equipment list, ECM stacks packaging design, and CEPACS plant layout were developed to facilitate the economic analysis. Vendor quotes were also solicited. The economic feasibility study included estimation of CEPACS plant capital cost, cost of electricity (COE) analyses and estimation of cost per ton of CO 2 captured. The incremental COE for the ECM-based CO 2 capture is expected to meet U.S. DOE’s target of 35%. This study has indicated that CEPACS systems offer significant benefits with respect to cost, performance, water consumption and emissions to environment. The realization of these benefits will provide a single solution to carbon dioxide capture in addition to meeting the increasing demand for electricity.« less

Updated (BP3) Technical and Economic Feasibility Study - Electrochemical Membrane for Carbon Dioxide Capture and Power Generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghezel-Ayagh, Hossein

This topical report summarizes the results of an updated Technical & Economic Feasibility Study (T&EFS) which was conducted in Budget Period 3 of the project to evaluate the performance and cost of the Electrochemical Membrane (ECM)-based CO2 capture system. The ECM technology is derived from commercially available inorganic membranes; the same used in FuelCell Energy’s commercial fuel cell power plants and sold under the trade name Direct FuelCell® (DFC®). The ECM stacks are utilized in the Combined Electric Power (generation) And Carbon dioxide Separation (CEPACS) systems which can be deployed as add-ons to conventional power plants (Pulverized Coal, Combined Cycle,more » etc.) or industrial facilities to simultaneously produce power while capturing >90% of the CO2 from the flue gas. In this study, an ECM-based CEPACS plant was designed to capture and compress >90% of the CO2 (for sequestration or beneficial use) from the flue gas of a reference 550 MW (nominal, net AC) Pulverized Coal (PC) Rankine Cycle (Subcritical steam) power plant. ECM performance was updated based on bench scale ECM stack test results. The system process simulations were performed to generate the CEPACS plant performance estimates. The performance assessment included estimation of the parasitic power consumption for CO2 capture and compression, and the efficiency impact on the PC plant. While the ECM-based CEPACS system for the 550 MW PC plant captures 90% of CO2 from the flue gas, it generates additional (net AC) power after compensating for the auxiliary power requirements of CO2 capture and compression. An equipment list, ECM stacks packaging design, and CEPACS plant layout were developed to facilitate the economic analysis. Vendor quotes were also solicited. The economic feasibility study included estimation of CEPACS plant capital cost, cost of electricity (COE) analyses and estimation of cost per ton of CO2 captured. The incremental COE for the ECM-based CO2 capture is expected to meet U.S. DOE’s target of 35%. This study has indicated that CEPACS systems offer significant benefits with respect to cost, performance, water consumption and emissions to environment. The realization of these benefits will provide a single solution to carbon dioxide capture in addition to meeting the increasing demand for electricity.« less

Bis(2,2'-bipyridyl-κN,N')(carbonato-κO,O')cobalt(III) bromide trihydrate.

PubMed

Ma, Peng-Tao; Wang, Yu-Xia; Zhang, Guo-Qian; Li, Ming-Xue

2007-12-06

The title complex, [Co(CO(3))(C(10)H(8)N(2))(2)]Br·3H(2)O, is isostructural with the chloride analogue. The six-coordinated octahedral [Co(2,2'-bipy)(2)CO(3)](+) cation (2,2'-bipy is 2,2'-bipyrid-yl), bromide ion and water mol-ecules are linked together via O-H⋯Br and O-H⋯O hydrogen bonds, generating a one-dimensional chain.

Oxygen Vacancy Engineering of Co3 O4 Nanocrystals through Coupling with Metal Support for Water Oxidation.

PubMed

Zhang, Jun-Jun; Wang, Hong-Hui; Zhao, Tian-Jian; Zhang, Ke-Xin; Wei, Xiao; Jiang, Zhi-Dong; Hirano, Shin-Ichi; Li, Xin-Hao; Chen, Jie-Sheng

2017-07-21

Oxygen vacancies can help to capture oxygen-containing species and act as active centers for oxygen evolution reaction (OER). Unfortunately, effective methods for generating a high amount of oxygen vacancies on the surface of various nanocatalysts are rather limited. Here, we described an effective way to generate oxygen-vacancy-rich surface of transition metal oxides, exemplified with Co 3 O 4 , simply by constructing highly coupled interface of ultrafine Co 3 O 4 nanocrystals and metallic Ti. Impressively, the amounts of oxygen vacancy on the surface of Co 3 O 4 /Ti surpassed the reported values of the Co 3 O 4 modified even under highly critical conditions. The Co 3 O 4 /Ti electrode could provide a current density of 23 mA cm -2 at an OER overpotential of 570 mV, low Tafel slope, and excellent durability in neutral medium. Because of the formation of a large amount of oxygen vacancies as the active centers for OER on the surface, the TOF value of the Co 3 O 4 @Ti electrode was optimized to be 3238 h -1 at an OER overpotential of 570 mV, which is 380 times that of the state-of-the-art non-noble nanocatalysts in the literature. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Predicting the ultimate potential of natural gas SOFC power cycles with CO2 capture - Part B: Applications

NASA Astrophysics Data System (ADS)

Campanari, Stefano; Mastropasqua, Luca; Gazzani, Matteo; Chiesa, Paolo; Romano, Matteo C.

2016-09-01

An important advantage of solid oxide fuel cells (SOFC) as future systems for large scale power generation is the possibility of being efficiently integrated with processes for CO2 capture. Focusing on natural gas power generation, Part A of this work assessed the performances of advanced pressurised and atmospheric plant configurations (SOFC + GT and SOFC + ST, with fuel cell integration within a gas turbine or a steam turbine cycle) without CO2 separation. This Part B paper investigates such kind of power cycles when applied to CO2 capture, proposing two ultra-high efficiency plant configurations based on advanced intermediate-temperature SOFCs with internal reforming and low temperature CO2 separation process. The power plants are simulated at the 100 MW scale with a set of realistic assumptions about FC performances, main components and auxiliaries, and show the capability of exceeding 70% LHV efficiency with high CO2 capture (above 80%) and a low specific primary energy consumption for the CO2 avoided (1.1-2.4 MJ kg-1). Detailed results are presented in terms of energy and material balances, and a sensitivity analysis of plant performance is developed vs. FC voltage and fuel utilisation to investigate possible long-term improvements. Options for further improvement of the CO2 capture efficiency are also addressed.

Intermediates of peroxisomal beta-oxidation. A study of the fatty acyl-CoA esters which accumulate during peroxisomal beta-oxidation of [U-14C]hexadecanoate.

PubMed Central

Bartlett, K; Hovik, R; Eaton, S; Watmough, N J; Osmundsen, H

1990-01-01

1. 14C-labelled fatty acyl-CoA esters resulting from beta-oxidation of [U-14C]hexadecanoate by peroxisomal fractions isolated from rats treated with clofibrate showed the presence of the full range of saturated intermediates down to acetyl-CoA. 2. The pattern of intermediates generated was fairly constant. At low concentrations of [U-14C]hexadecanoate (50 microM), decanoyl-CoA was present in lowest amounts. At higher concentrations of [U-14C]hexadecanoate (greater than 100 microM), all intermediates of chain length shorter than 12 carbon atoms (except acetyl-CoA) were present at similar low concentrations; the process of beta-oxidation now resembling chain-shortening of hexadecanoate by two cycles of beta-oxidation. 3. In the absence of an NAD(+)-regenerating system [pyruvate and lactate dehydrogenase (EC 1.1.1.28)] 2-enoyl- and 3-hydroxyacyl-CoA esters were generated, suggesting that re-oxidation of NADH is essential for optimal rates of peroxisomal beta-oxidation in vitro. 4. At high concentrations of [U-14C]hexadecanoate (greater than 100 microM), 3-oxohexadecanoyl-CoA was produced, suggesting that thiolase (acetyl-CoA acetyltransferase; EC 2.3.1.9) can become rate-limiting for peroxisomal beta-oxidation. Images Fig. 2. Fig. 3. Fig. 4. PMID:2396977

Towards a Representation of Flexible Canopy N Stiochiometry for Land-surface Models Based on Optimality Concepts

NASA Astrophysics Data System (ADS)

Zaehle, S.; Caldararu, S.

2015-12-01

Foliar nitrogen (N) is know to acclimate to environmental conditions. One particular pertinent response is the general decline in foliar N following exposure to elevated levels of atmospheric CO2 (eCO2). Associated with reduced foliar N is an increased plant nitrogen-use efficiency, which contributes to the plants' sustained growth response to eCO2 in the absence of any counteracting litter N feedbacks. Flexible leaf N thus has important consequences for the mid- to long-term response of terrestrial ecosystems to eCO2. The current generation of land-surface models including a prognostic N cycle generally employ heuristic, and simply mass-balancing parameterisations to estimate changes in stoichiometry given altered N and carbon (C) availability. This generation generally and substantially overestimates the decline of foliar N (and thus the increase in plant nitrogen use efficiency) observed in Free Air CO2 Enrichment Experiments (FACE; Zaehle et al. 2014). In this presentation, I develop a simple, prognostic and dynamic representation of flexible foliar N for use in land-surface models by maximising the marginal gain of net assimilation with respect to the energy investment to generate foliar area and foliar N. I elucidate the underlying assumptions required to simulate the commonly observed decline in foliar N with eCO2 under different scenarios of N availability (Feng et al. 2015). References: Zaehle, Sönke, Belinda E Medlyn, Martin G De Kauwe, Anthony P Walker, Michael C Dietze, Hickler Thomas, Yiqi Luo, et al. 2014. "Evaluation of 11 Terrestrial Carbon-Nitrogen Cycle Models Against Observations From Two Temperate Free-Air CO2 Enrichment Studies." New Phytologist 202 (3): 803-22. doi:10.1111/nph.12697. Feng, Zhaozhong, Tobias RUtting, Håkan Pleijel, GORAN WALLIN, Peter B Reich, Claudia I Kammann, Paul C D Newton, Kazuhiko Kobayashi, Yunjian Luo, and Johan Uddling. 2015. "Constraints to Nitrogen Acquisition of Terrestrial Plants Under Elevated CO 2." Global Change Biology 21 (8): 3152-68. doi:10.1111/gcb.12938.

Quality of tri-Co-60 MR-IGRT treatment plans in comparison with VMAT treatment plans for spine SABR.

PubMed

Choi, Chang Heon; Park, So-Yeon; Kim, Jung-In; Kim, Jin Ho; Kim, Kyubo; Carlson, Joel; Park, Jong Min

2017-02-01

To investigate the plan quality of tri-Co-60 intensity-modulated radiation therapy (IMRT) plans for spine stereotactic ablative radiotherapy (SABR). A total of 20 patients with spine metastasis were retrospectively selected. For each patient, a tri-Co-60 IMRT plan and a volumetric-modulated arc therapy (VMAT) plan were generated. The spinal cords were defined based on MR images for the tri-Co-60 IMRT, while isotropic 1-mm margins were added to the spinal cords for the VMAT plans. The VMAT plans were generated with 10-MV flattening filter-free photon beams of TrueBeam STx ™ (Varian Medical Systems, Palo Alto, CA), while the tri-Co-60 IMRT plans were generated with the ViewRay ™ system (ViewRay inc., Cleveland, OH). The initial prescription dose was 18 Gy (1 fraction). If the tolerance dose of the spinal cord was not met, the prescription dose was reduced until the spinal cord tolerance dose was satisfied. The mean dose to the target volumes, conformity index and homogeneity index of the VMAT and tri-Co-60 IMRT were 17.8 ± 0.8 vs 13.7 ± 3.9 Gy, 0.85 ± 0.20 vs 1.58 ± 1.29 and 0.09 ± 0.04 vs 0.24 ± 0.19, respectively. The integral doses and beam-on times were 16,570 ± 1768 vs 22,087 ± 2.986 Gy cm 3 and 3.95 ± 1.13 vs 48.82 ± 10.44 min, respectively. The tri-Co-60 IMRT seems inappropriate for spine SABR compared with VMAT. Advances in knowledge: For spine SABR, the tri-Co-60 IMRT is inappropriate owing to the large penumbra, large leaf width and low dose rate of the ViewRay system.

Quality of tri-Co-60 MR-IGRT treatment plans in comparison with VMAT treatment plans for spine SABR

PubMed Central

Choi, Chang Heon; Park, So-Yeon; Kim, Jung-in; Kim, Jin Ho; Kim, Kyubo; Carlson, Joel

2017-01-01

Objective: To investigate the plan quality of tri-Co-60 intensity-modulated radiation therapy (IMRT) plans for spine stereotactic ablative radiotherapy (SABR). Methods: A total of 20 patients with spine metastasis were retrospectively selected. For each patient, a tri-Co-60 IMRT plan and a volumetric-modulated arc therapy (VMAT) plan were generated. The spinal cords were defined based on MR images for the tri-Co-60 IMRT, while isotropic 1-mm margins were added to the spinal cords for the VMAT plans. The VMAT plans were generated with 10-MV flattening filter-free photon beams of TrueBeam STx™ (Varian Medical Systems, Palo Alto, CA), while the tri-Co-60 IMRT plans were generated with the ViewRay™ system (ViewRay inc., Cleveland, OH). The initial prescription dose was 18 Gy (1 fraction). If the tolerance dose of the spinal cord was not met, the prescription dose was reduced until the spinal cord tolerance dose was satisfied. Results: The mean dose to the target volumes, conformity index and homogeneity index of the VMAT and tri-Co-60 IMRT were 17.8 ± 0.8 vs 13.7 ± 3.9 Gy, 0.85 ± 0.20 vs 1.58 ± 1.29 and 0.09 ± 0.04 vs 0.24 ± 0.19, respectively. The integral doses and beam-on times were 16,570 ± 1768 vs 22,087 ± 2.986 Gy cm3 and 3.95 ± 1.13 vs 48.82 ± 10.44 min, respectively. Conclusion: The tri-Co-60 IMRT seems inappropriate for spine SABR compared with VMAT. Advances in knowledge: For spine SABR, the tri-Co-60 IMRT is inappropriate owing to the large penumbra, large leaf width and low dose rate of the ViewRay system. PMID:27781486

Next-Generation Magnetic Nanocomposites: Cytotoxic and Genotoxic Effects of Coated and Uncoated Ferric Cobalt Boron (FeCoB) Nanoparticles In Vitro.

PubMed

Netzer, Katharina; Jordakieva, Galateja; Girard, Angelika M; Budinsky, Alexandra C; Pilger, Alexander; Richter, Lukas; Kataeva, Nadezhda; Schotter, Joerg; Godnic-Cvar, Jasminka; Ertl, Peter

2018-03-01

Metal nanoparticles (NPs) have unique physicochemical properties and a widespread application scope depending on their composition and surface characteristics. Potential biomedical applications and the growing diversity of novel nanocomposites highlight the need for toxicological hazard assessment of next-generation magnetic nanomaterials. Our study aimed to evaluate the cytotoxic and genotoxic properties of coated and uncoated ferric cobalt boron (FeCoB) NPs (5-15 nm particle size) in cultured normal human dermal fibroblasts. Cell proliferation was assessed via ATP bioluminescence kit, and DNA breakage and chromosomal damage were measured by alkaline comet assay and micronucleus test. Polyacryl acid-coated FeCoB NPs [polyacrylic acid (PAA)-FeCoB NPs) and uncoated FeCoB NPs inhibited cell proliferation at 10 μg/ml. DNA strand breaks were significantly increased by PAA-coated FeCoB NPs, uncoated FeCoB NPs and l-cysteine-coated FeCoB NPs (Cys-FeCoB NPs), although high concentrations (10 μg/ml) of coated NPs (Cys- and PAA-FeCoB NPs) showed significantly more DNA breakage when compared to uncoated ones. Uncoated FeCoB NPs and coated NPs (PAA-FeCoB NPs) also induced the formation of micronuclei. Additionally, PAA-coated NPs and uncoated FeCoB NPs showed a negative correlation between cell proliferation and DNA strand breaks, suggesting a common pathomechanism, possibly by oxidation-induced DNA damage. We conclude that uncoated FeCoB NPs are cytotoxic and genotoxic at in vitro conditions. Surface coating of FeCoB NPs with Cys and PAA does not prevent but rather aggravates DNA damage. Further safety assessment and a well-considered choice of surface coating are needed prior to application of FeCoB nanocomposites in biomedicine. © 2017 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

Drivers of biomass co-firing in U.S. coal-fired power plants

Treesearch

Michael E. Goerndt; Francisco X. Aguilar; Kenneth Skog

2013-01-01

Substantial knowledge has been generated in the U.S. about the resource base for forest and other residue-derived biomass for bioenergy including co-firing in power plants. However, a lack of understanding regarding power plant-level operations and manager perceptions of drivers of biomass co-firing remains. This study gathered information from U.S. power plant...

Microbial Reverse-Electrodialysis Electrolysis and Chemical-Production Cell for H2 Production and CO2 Sequestration.

PubMed

Zhu, Xiuping; Hatzell, Marta C; Logan, Bruce E

2014-04-08

Natural mineral carbonation can be accelerated using acid and alkali solutions to enhance atmospheric CO 2 sequestration, but the production of these solutions needs to be carbon-neutral. A microbial reverse-electrodialysis electrolysis and chemical-production cell (MRECC) was developed to produce these solutions and H 2 gas using only renewable energy sources (organic matter and salinity gradient). Using acetate (0.82 g/L) as a fuel for microorganisms to generate electricity in the anode chamber (liquid volume of 28 mL), 0.45 mmol of acid and 1.09 mmol of alkali were produced at production efficiencies of 35% and 86%, respectively, along with 10 mL of H 2 gas. Serpentine dissolution was enhanced 17-87-fold using the acid solution, with approximately 9 mL of CO 2 absorbed and 4 mg of CO 2 fixed as magnesium or calcium carbonates. The operational costs, based on mineral digging and grinding, and water pumping, were estimated to be only $25/metric ton of CO 2 fixed as insoluble carbonates. Considering the additional economic benefits of H 2 generation and possible wastewater treatment, this method may be a cost-effective and environmentally friendly method for CO 2 sequestration.

Near-term implications of a ban on new coal-fired power plants in the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adam Newcomer; Jay Apt

2009-06-15

Large numbers of proposed new coal power generators in the United States have been cancelled, and some states have prohibited new coal power generators. We examine the effects on the U.S. electric power system of banning the construction of coal-fired electricity generators, which has been proposed as a means to reduce U.S. CO{sub 2} emissions. The model simulates load growth, resource planning, and economic dispatch of the Midwest Independent Transmission System Operator (ISO), Inc., Electric Reliability Council of Texas (ERCOT), and PJM under a ban on new coal generation and uses an economic dispatch model to calculate the resulting changesmore » in dispatch order, CO{sub 2} emissions, and fuel use under three near-term (until 2030) future electric power sector scenarios. A national ban on new coal-fired power plants does not lead to CO{sub 2} reductions of the scale required under proposed federal legislation such as Lieberman-Warner but would greatly increase the fraction of time when natural gas sets the price of electricity, even with aggressive wind and demand response policies. 50 refs., 5 figs., 4 tabs.« less

Determining the Optimal Solution for Quadratically Constrained Quadratic Programming (QCQP) on Energy-Saving Generation Dispatch Problem

NASA Astrophysics Data System (ADS)

Lesmana, E.; Chaerani, D.; Khansa, H. N.

2018-03-01

Energy-Saving Generation Dispatch (ESGD) is a scheme made by Chinese Government in attempt to minimize CO2 emission produced by power plant. This scheme is made related to global warming which is primarily caused by too much CO2 in earth’s atmosphere, and while the need of electricity is something absolute, the power plants producing it are mostly thermal-power plant which produced many CO2. Many approach to fulfill this scheme has been made, one of them came through Minimum Cost Flow in which resulted in a Quadratically Constrained Quadratic Programming (QCQP) form. In this paper, ESGD problem with Minimum Cost Flow in QCQP form will be solved using Lagrange’s Multiplier Method

Current induced domain wall motion in antiferromagnetically coupled (Co70Fe30/Pd) multilayer nanowires

NASA Astrophysics Data System (ADS)

Meng, Zhaoliang; He, Shikun; Huang, Lisen; Qiu, Jinjun; Zhou, Tiejun; Panagopoulos, Christos; Han, Guchang; Teo, Kie-Leong

2016-10-01

We investigate the current induced domain wall (DW) motion in the ultrathin CoFe/Pd multilayer based synthetically antiferromagnetic (SAF) structure nanowires by anomalous Hall effect measurement. The threshold current density (Jth) for the DW displacement decreases and the DW velocity (v) increases accordingly with the exchange coupling Jex between the top and bottom ferromagnetic CoFe/Pd multilayers. The lowest Jth = 9.3 × 1010 A/m2 and a maximum v = 150 m/s with J = 1.5 × 1012 A/m2 are achieved due to the exchange coupling torque (ECT) generated in the SAF structure. The strength of ECT is dependent on both of Jex and the strong spin-orbit torque mainly generated by Ta layer.

Cobalt-supported alumina as catalytic film prepared by electrophoretic deposition for hydrogen release applications

NASA Astrophysics Data System (ADS)

Chamoun, R.; Demirci, U. B.; Cornu, D.; Zaatar, Y.; Khoury, A.; Khoury, R.; Miele, P.

2010-10-01

Shaped catalysts are crucial for technological applications. In this context, we have developed Co-αAl 2O 3 catalyst films deposited over Cu plates to be used in hydrogen generation by hydrolysis of sodium borohydride NaBH 4 in alkaline solution. The Co-αAl 2O 3 films were prepared by electrophoretic deposition according to six different routes. While five of them failed in fabricating adhering films, the sixth route, consisting of electrodepositing Co-impregnated αAl 2O 3, showed promising results. The as-obtained shaped catalysts were stable when hydrogen vigorously bubbled and catalyzed the NaBH 4 hydrolysis with attractive hydrogen generation rates. These results open an alternative route for preparing shaped catalysts in this reaction.

Generation of runaway electrons beams during the breakdown of high-pressure gases

NASA Astrophysics Data System (ADS)

Tarasenko, V. F.; Burachenko, A. G.; Baksht, E. Kh

2017-11-01

Generation of run-away electrons in SF6, CO2, argon and nitrogen at high and super high pressures is studied. Super-short avalanches electron beams (SAEB) was obtained and measured with a collector at pressures up to 0.3, 0.7, 1.0 and 1.2 MPa in SF6, CO2, argon and nitrogen, respectively. The SAEB duration was shown to be ∼60 ps (FWHM) and gas composition has only minor effect on the duration. It was found that in a gap of 4 mm in SF6, CO2, argon and nitrogen at pressure up to 0.3, 0.7, 1.0 и 1.2 MPa the voltage pulse duration (FWHM) and amplitude increase with pressure.

Development of molecular electrocatalysts for CO2 reduction and H2 production/oxidation.

PubMed

Rakowski DuBois, M; DuBois, Daniel L

2009-12-21

The conversion of solar energy to fuels in both natural and artificial photosynthesis requires components for both light-harvesting and catalysis. The light-harvesting component generates the electrochemical potentials required to drive fuel-generating reactions that would otherwise be thermodynamically uphill. This Account focuses on work from our laboratories on developing molecular electrocatalysts for CO(2) reduction and for hydrogen production. A true analog of natural photosynthesis will require the ability to capture CO(2) from the atmosphere and reduce it to a useful fuel. Work in our laboratories has focused on both aspects of this problem. Organic compounds such as quinones and inorganic metal complexes can serve as redox-active CO(2) carriers for concentrating CO(2). We have developed catalysts for CO(2) reduction to form CO based on a [Pd(triphosphine)(solvent)](2+) platform. Catalytic activity requires the presence of a weakly coordinating solvent molecule that can dissociate during the catalytic cycle and provide a vacant coordination site for binding water and assisting C-O bond cleavage. Structures of [NiFe] CO dehydrogenase enzymes and the results of studies on complexes containing two [Pd(triphosphine)(solvent)](2+) units suggest that participation of a second metal in CO(2) binding may also be required for achieving very active catalysts. We also describe molecular electrocatalysts for H(2) production and oxidation based on [Ni(diphosphine)(2)](2+) complexes. Similar to palladium CO(2) reduction catalysts, these species require the optimization of both first and second coordination spheres. In this case, we use structural features of the first coordination sphere to optimize the hydride acceptor ability of nickel needed to achieve heterolytic cleavage of H(2). We use the second coordination sphere to incorporate pendant bases that assist in a number of important functions including H(2) binding, H(2) cleavage, and the transfer of protons between nickel and solution. These pendant bases, or proton relays, are likely to be important in the design of catalysts for a wide range of fuel production and fuel utilization reactions involving multiple electron and proton transfer steps. The generation of fuels from abundant substrates such as CO(2) and water remains a daunting research challenge, requiring significant advances in new inexpensive materials for light harvesting and the development of fast, stable, and efficient electrocatalysts. Although we describe progress in the development of redox-active carriers capable of concentrating CO(2) and molecular electrocatalysts for CO(2) reduction, hydrogen production, and hydrogen oxidation, much more remains to be done.

Role of Acentric Displacements on the Crystal Structure and Second-Harmonic Generating Properties of RbPbCO3F and CsPbCO3F

PubMed Central

2015-01-01

Two lead fluorocarbonates, RbPbCO3F and CsPbCO3F, were synthesized and characterized. The materials were synthesized through solvothermal and conventional solid-state techniques. RbPbCO3F and CsPbCO3F were structurally characterized by single-crystal X-ray diffraction and exhibit three-dimensional (3D) crystal structures consisting of corner-shared PbO6F2 polyhedra. For RbPbCO3F, infrared and ultraviolet–visible spectroscopy and thermogravimetric and differential thermal analysis measurements were performed. RbPbCO3F is a new noncentrosymmetric material and crystallizes in the achiral and nonpolar space group P6̅m2 (crystal class 6̅m2). Powder second-harmonic generation (SHG) measurements on RbPbCO3F and CsPbCO3F using 1064 nm radiation revealed an SHG efficiency of approximately 250 and 300 × α-SiO2, respectively. Charge constants d33 of approximately 72 and 94 pm/V were obtained for RbPbCO3F and CsPbCO3F, respectively, through converse piezoelectric measurements. Electronic structure calculations indicate that the nonlinear optical response originates from the distorted PbO6F2 polyhedra, because of the even–odd parity mixing of the O 2p states with the nearly spherically symmetric 6s electrons of Pb2+. The degree of inversion symmetry breaking is quantified using a mode-polarization vector analysis and is correlated with cation size mismatch, from which it is possible to deduce the acentric properties of 3D alkali-metal fluorocarbonates. PMID:24867361

The system-wide economics of a carbon dioxide capture, utilization, and storage network: Texas Gulf Coast with pure CO2-EOR flood

NASA Astrophysics Data System (ADS)

King, Carey W.; Gülen, Gürcan; Cohen, Stuart M.; Nuñez-Lopez, Vanessa

2013-09-01

This letter compares several bounding cases for understanding the economic viability of capturing large quantities of anthropogenic CO2 from coal-fired power generators within the Electric Reliability Council of Texas electric grid and using it for pure CO2 enhanced oil recovery (EOR) in the onshore coastal region of Texas along the Gulf of Mexico. All captured CO2 in excess of that needed for EOR is sequestered in saline formations at the same geographic locations as the oil reservoirs but at a different depth. We analyze the extraction of oil from the same set of ten reservoirs within 20- and five-year time frames to describe how the scale of the carbon dioxide capture, utilization, and storage (CCUS) network changes to meet the rate of CO2 demand for oil recovery. Our analysis shows that there is a negative system-wide net present value (NPV) for all modeled scenarios. The system comes close to breakeven economics when capturing CO2 from three coal-fired power plants to produce oil via CO2-EOR over 20 years and assuming no CO2 emissions penalty. The NPV drops when we consider a larger network to produce oil more quickly (21 coal-fired generators with CO2 capture to produce 80% of the oil within five years). Upon applying a CO2 emissions penalty of 602009/tCO2 to fossil fuel emissions to ensure that coal-fired power plants with CO2 capture remain in baseload operation, the system economics drop significantly. We show near profitability for the cash flow of the EOR operations only; however, this situation requires relatively cheap electricity prices during operation.

Chemical and isotopic equilibrium between CO 2 and CH 4 in fumarolic gas discharges: Generation of CH 4 in arc magmatic-hydrothermal systems

NASA Astrophysics Data System (ADS)

Fiebig, Jens; Chiodini, Giovanni; Caliro, Stefano; Rizzo, Andrea; Spangenberg, Jorge; Hunziker, Johannes C.

2004-05-01

The chemical and isotopic composition of fumarolic gases emitted from Nisyros Volcano, Greece, and of a single gas sample from Vesuvio, Italy, was investigated in order to determine the origin of methane (CH 4) within two subduction-related magmatic-hydrothermal environments. Apparent temperatures derived from carbon isotope partitioning between CH 4 and CO 2 of around 340°C for Nisyros and 470°C for Vesuvio correlate well with aquifer temperatures as measured directly and/or inferred from compositional data using the H 2O-H 2-CO 2-CO-CH 4 geothermometer. Thermodynamic modeling reveals chemical equilibrium between CH 4, CO 2 and H 2O implying that carbon isotope partitioning between CO 2 and CH 4 in both systems is controlled by aquifer temperature. N 2/ 3He and CH 4/ 3He ratios of Nisyros fumarolic gases are unusually low for subduction zone gases and correspond to those of midoceanic ridge environments. Accordingly, CH 4 may have been primarily generated through the reduction of CO 2 by H 2 in the absence of any organic matter following a Fischer-Tropsch-type reaction. However, primary occurrence of minor amounts of thermogenic CH 4 and subsequent re-equilibration with co-existing CO 2 cannot be ruled out entirely. CO 2/ 3He ratios and δ 13C CO 2 values imply that the evolved CO 2 either derives from a metasomatized mantle or is a mixture between two components, one outgassing from an unaltered mantle and the other released by thermal breakdown of marine carbonates. The latter may contain traces of organic matter possibly decomposing to CH 4 during thermometamorphism.

Response of Spring Diatoms to CO2 Availability in the Western North Pacific as Determined by Next-Generation Sequencing.

PubMed

Endo, Hisashi; Sugie, Koji; Yoshimura, Takeshi; Suzuki, Koji

2016-01-01

Next-generation sequencing (NGS) technologies have enabled us to determine phytoplankton community compositions at high resolution. However, few studies have adopted this approach to assess the responses of natural phytoplankton communities to environmental change. Here, we report the impact of different CO2 levels on spring diatoms in the Oyashio region of the western North Pacific as estimated by NGS of the diatom-specific rbcL gene (DNA), which encodes the large subunit of RubisCO. We also examined the abundance and composition of rbcL transcripts (cDNA) in diatoms to assess their physiological responses to changing CO2 levels. A short-term (3-day) incubation experiment was carried out on-deck using surface Oyashio waters under different pCO2 levels (180, 350, 750, and 1000 μatm) in May 2011. During the incubation, the transcript abundance of the diatom-specific rbcL gene decreased with an increase in seawater pCO2 levels. These results suggest that CO2 fixation capacity of diatoms decreased rapidly under elevated CO2 levels. In the high CO2 treatments (750 and 1000 μatm), diversity of diatom-specific rbcL gene and its transcripts decreased relative to the control treatment (350 μatm), as well as contributions of Chaetocerataceae, Thalassiosiraceae, and Fragilariaceae to the total population, but the contributions of Bacillariaceae increased. In the low CO2 treatment, contributions of Bacillariaceae also increased together with other eukaryotes. These suggest that changes in CO2 levels can alter the community composition of spring diatoms in the Oyashio region. Overall, the NGS technology provided us a deeper understanding of the response of diatoms to changes in CO2 levels in terms of their community composition, diversity, and photosynthetic physiology.

Menopause: no support for an evolutionary explanation among historical Norwegians.

PubMed

Skjærvø, Gine Roll; Røskaft, Eivin

2013-04-01

Life history theory proposes that menopause is either an epiphenomenon or an adaptation. The most recent adaptive hypothesis proposes that menopause in humans has evolved because of conflict between reproducing generations (RCH). Overlapping reproduction between generations may impose fitness costs to older and younger females who co-breed. However, it has yet to be demonstrated by using a measure of evolutionary fitness (i.e. grandchildren). Here, we tested the RCH by using multigenerational life-history data of historical Norwegian women. Our results indicate that both generations seem to experience some fitness benefits with co-breeding (i.e. reproductive overlap and cohabit). This was because both younger and older females who co-bred had more grandchildren than those who did not co-breed. We suggest that younger females may partly had enhanced fitness because they copied behaviour of females of the older generation. Our results do not support the hypothesis that reproductive conflict between generations explains the evolution of menopause in women. Our results, taken together with the growing evidence against several assumptions of the RCH, indicate that 1) the decline in follicle number has no marked increase in women as they reach the age of 38 years; 2) humans do not have an abrupt decline in fertility at mean age of 38 years; 3) menopause is not unique to humans; and 4) there are not high numbers of individuals surviving to older adulthood during our evolutionary past. Finally, we discuss an alternative point of view suggesting that menopause might be understood in the light of both ageing in general as well as our increased lifespan. Copyright © 2013 Elsevier Inc. All rights reserved.

Carbon monoxide poisonings from small, gasoline-powered, internal combustion engines: just what is a "well-ventilated area"?

PubMed

Earnest, G S; Mickelsen, R L; McCammon, J B; O'Brien, D M

1997-11-01

This study modeled the time required for a gasoline-powered, 5 horsepower (hp), 4-cycle engine to generate carbon monoxide (CO) concentrations exceeding the National Institute for Occupational Safety and Health 200-ppm ceiling and 1200-ppm immediately dangerous to life and health concentration for various room sizes and ventilation rates. The model permitted the ambiguous term "well-ventilated area" to be defined. The model was compared with field data collected at a site where two workers were poisoned while operating a 5-hp concrete saw in a bathroom having open doors and an operating ventilation system. There is agreement between both the modeled and field-generated data, indicating that hazardous CO concentrations can develop within minutes. Comparison of field and modeling data showed the measured CO generation rate at approximately one-half of the value used in the model, which may be partially because the engine used in the field was not under load during data collection. The generation rate and room size from the actual poisoning was then used in the model. The model determined that ventilation rates of nearly 5000 ft3/min (120 air changes per hour) would be required to prevent the CO concentration from exceeding the 200-ppm ceiling for short periods. Results suggest that small gasoline-powered engines should not be operated inside of buildings or in semienclosed spaces and that manufacturers of such tools should improve their warnings and develop engineering control options for better user protection.

An Environmental Impact Analysis of Semi-Mechanical Extraction Process of Sago Starch: Life Cycle Assessment (LCA) Perspective

NASA Astrophysics Data System (ADS)

Yusuf, M. A.; Romli, M.; Suprihatin; Wiloso, E. I.

2018-05-01

Industrial activities use material, energy and water resources and generate greenhouse gas (GHG). Currently, various regulations require industry to measure and quantify the emissions generated from its process activity. LCA is a method that can be used to analyze and report the environmental impact of an activity that uses resources and generates waste by an industrial activity. In this work, LCA is used to determine the environmental impact of a semi-mechanical extraction process of sago industry. The data was collected through the sago industry in Cimahpar, Bogor. The extraction of sago starch consists of stem cutting, rasping, mixing, filtration, starch sedimentation, washing, and drying. The scope of LCA study covers the harvesting of sago stem, transportation to extraction site, and the starch extraction process. With the assumption that the average transportation distance of sago stem to extraction site is 200 km, the GHG emission is estimated to be 325 kg CO2 eq / ton of sundried sago starch. This figure is lower than that reported for maize starch (1120 kg CO2 eq), potato starch (2232 kg CO2 eq) and cassava starch (4310 kg CO2 eq). This is most likely due to the uncounted impact from the use of electrical energy on the extraction process, which is currently being conducted. A follow-up study is also underway to formulate several process improvement scenarios to derive the design of sago starch processing that generates the minimum emissions.

Probing the interaction of Rh, Co and bimetallic Rh-Co nanoparticles with the CeO2 support: catalytic materials for alternative energy generation.

PubMed

Varga, E; Pusztai, P; Óvári, L; Oszkó, A; Erdőhelyi, A; Papp, C; Steinrück, H-P; Kónya, Z; Kiss, J

2015-10-28

The interaction of CeO2-supported Rh, Co and bimetallic Rh-Co nanoparticles, which are active catalysts in hydrogen production via steam reforming of ethanol, a process related to renewable energy generation, was studied by X-ray diffraction (XRD), high resolution electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and low energy ion scattering (LEIS). Furthermore, diffuse reflectance infrared spectroscopy (DRIFTS) of adsorbed CO as a probe molecule was used to characterize the morphology of metal particles. At small loadings (0.1%), Rh is in a much dispersed state on ceria, while at higher contents (1-5%), Rh forms 2-8 nm particles. Between 473-673 K pronounced oxygen transfer from ceria to Rh is observed and at 773 K significant agglomeration of Rh occurs. On reduced ceria, XPS indicates a possible electron transfer from Rh to ceria. The formation of smaller ceria crystallites upon loading with Co was concluded from XRD and HRTEM; for 10% Co, the CeO2 particle size decreased from 27.6 to 10.7 nm. A strong dissolution of Co into ceria and a certain extent of encapsulation by ceria were deduced by XRD, XPS and LEIS. In the bimetallic system, the presence of Rh enhances the reduction of cobalt and ceria. During thermal treatments, reoxidation of Co occurs, and Rh agglomeration as well as oxygen migration from ceria to Rh are hindered in the presence of cobalt.

Long-term operation of microbial electrosynthesis cell reducing CO2 to multi-carbon chemicals with a mixed culture avoiding methanogenesis.

PubMed

Bajracharya, Suman; Yuliasni, Rustiana; Vanbroekhoven, Karolien; Buisman, Cees J N; Strik, David P B T B; Pant, Deepak

2017-02-01

In microbial electrosynthesis (MES), CO 2 can be reduced preferably to multi-carbon chemicals by a biocathode-based process which uses electrochemically active bacteria as catalysts. A mixed anaerobic consortium from biological origin typically produces methane from CO 2 reduction which circumvents production of multi-carbon compounds. This study aimed to develop a stable and robust CO 2 reducing biocathode from a mixed culture inoculum avoiding the methane generation. An effective approach was demonstrated based on (i) an enrichment procedure involving inoculum pre-treatment and several culture transfers in H 2 :CO 2 media, (ii) a transfer from heterotrophic to autotrophic growth and (iii) a sequential batch operation. Biomass growth and gradual acclimation to CO 2 electro-reduction accomplished a maximum acetate production rate of 400mgL catholyte -1 d -1 at -1V (vs. Ag/AgCl). Methane was never detected in more than 300days of operation. Accumulation of acetate up to 7-10gL -1 was repeatedly attained by supplying (80:20) CO 2 :N 2 mixture at -0.9 to -1V (vs. Ag/AgCl). In addition, ethanol and butyrate were also produced from CO 2 reduction. Thus, a robust CO 2 reducing biocathode can be developed from a mixed culture avoiding methane generation by adopting the specific culture enrichment and operation procedures without the direct addition of chemical inhibitor. Copyright © 2016 Elsevier B.V. All rights reserved.

Inorganic Nanoparticles/Metal Organic Framework Hybrid Membrane Reactors for Efficient Photocatalytic Conversion of CO2.

PubMed

Maina, James W; Schütz, Jürg A; Grundy, Luke; Des Ligneris, Elise; Yi, Zhifeng; Kong, Lingxue; Pozo-Gonzalo, Cristina; Ionescu, Mihail; Dumée, Ludovic F

2017-10-11

Photocatalytic conversion of carbon dioxide (CO 2 ) to useful products has potential to address the adverse environmental impact of global warming. However, most photocatalysts used to date exhibit limited catalytic performance, due to poor CO 2 adsorption capacity, inability to efficiently generate photoexcited electrons, and/or poor transfer of the photogenerated electrons to CO 2 molecules adsorbed on the catalyst surface. The integration of inorganic semiconductor nanoparticles across metal organic framework (MOF) materials has potential to yield new hybrid materials, combining the high CO 2 adsorption capacity of MOF and the ability of the semiconductor nanoparticles to generate photoexcited electrons. Herein, controlled encapsulation of TiO 2 and Cu-TiO 2 nanoparticles within zeolitic imidazolate framework (ZIF-8) membranes was successfully accomplished, using rapid thermal deposition (RTD), and their photocatalytic efficiency toward CO 2 conversion was investigated under UV irradiation. Methanol and carbon monoxide (CO) were found to be the only products of the CO 2 reduction, with yields strongly dependent upon the content and composition of the dopant semiconductor particles. CuTiO 2 nanoparticle doped membranes exhibited the best photocatalytic performance, with 7 μg of the semiconductor nanoparticle enhancing CO yield of the pristine ZIF-8 membrane by 233%, and methanol yield by 70%. This work opens new routes for the fabrication of hybrid membranes containing inorganic nanoparticles and MOFs, with potential application not only in catalysis but also in electrochemical, separation, and sensing applications.

[Carbon footprint in five third-level health care centers in Peru, 2013].

PubMed

Bambarén-Alatrista, Celso; Alatrista-Gutiérrez, María Del Socorro

2016-06-01

This study was performed to calculate the carbon footprint generated by third-level health care centers located in Lima, Peru, in 2013. Reports were obtained on the consumption of energy resources and water as well as on waste generation from the five centers, which contributed to climate change with an emission of 14,462 teq of CO2. A total of 46% of these emissions were associated with fuel consumption by the powerhouse, power generators, and transport vehicles; 44% was related to energy consumption; and the remaining 10% was related to the use of water and generation of solid hospital waste. CO2, N2O, and CH4 are the greenhouse gases included in the estimated carbon footprint. Our results show that hospitals have a negative environmental impact, mainly due to fossil fuel consumption.

78 FR 32381 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-30

... that the Commission received the following electric rate filings: Docket Numbers: ER12-281-004; ER13..., Edgecombe Genco, LLC, EIF Hudson, LLC, Logan Generating Co L.P., RC Cape May Holdings, LLC, Richland-Stryker Generation LLC, Scrubgrass Generating Company, L.P., Spruance Genco, LLC, Starwood Energy Hudson Investors, L...

Activating Generative Learning in Organizations through Optimizing Relational Strategies

ERIC Educational Resources Information Center

Park, Mary Kay

2010-01-01

Using a grounded theory method, this dissertation seeks to discover how relationships impact organizational generative learning. An organization is a socially constructed reality and organizational learning is situated in the process of co-participation. To discover the link between relationships and generative learning this study considers the…

40 CFR 52.1670 - Identification of plans.

Code of Federal Regulations, 2011 CFR

2011-07-01

... percent, by weight, for the Long Island Lighting Co.'s Northport Generating Facility (Units 1, 2, and 3... oil limitation to 1.0 percent, by weight, for the Long Island Lighting Company's Glenwood Generating... of New York, Inc. Arthur Kill generating facility, units 2 and 3, Staten Island, New York and...

Multifunctional Porous Graphene for High-Efficiency Steam Generation by Heat Localization.

PubMed

Ito, Yoshikazu; Tanabe, Yoichi; Han, Jiuhui; Fujita, Takeshi; Tanigaki, Katsumi; Chen, Mingwei

2015-08-05

Multifunctional nanoporous graphene is realized as a heat generator to convert solar illumination into high-energy steam. The novel 3D nanoporous graphene demonstrates a highly energy-effective steam generation with an energy conversation of 80%. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Miniature Electromechanical Generator Design Utilizing Human Motion

DTIC Science & Technology

2010-09-01

Inductance Operating Range In the previous chapter, it was mentioned that the EMF induced from the generator was related to a time-changing magnetic...ELECTROMECHANICAL GENERATOR DESIGN UTILIZING HUMAN MOTION by Nicholas G. Hoffman September 2010 Thesis Co-Advisors: Alexander L. Julian...AND DATES COVERED Master’s Thesis 4. TITLE AND SUBTITLE A Miniature Electromechanical Generator Design Utilizing Human Motion 5. FUNDING NUMBERS

CO2 Removal and Atmosphere Revitalization Systems for Next Generation Space Flight

NASA Technical Reports Server (NTRS)

Luna, Bernadette; Mulloth, Lila M.; Varghese, Mini M.; Hogan, John Andrew

2010-01-01

Removal of metabolic CO2 from breathing air is a vital process for life support in all crewed space missions. A CO2 removal processor called the Low Power CO2 Removal (LPCOR) system is being developed in the Bioengineering Branch at NASA Ames Research Center. LPCOR utilizes advanced adsorption and membrane gas separation processes to achieve substantial power and mass reduction when compared to the state-of-the-art carbon dioxide removal assembly (CORA) of the US segment of the International Space Station (ISS). LPCOR is an attractive alternative for use in commercial spacecraft for short-duration missions and can easily be adapted for closed-loop life support applications. NASA envisions a next-generation closed-loop atmosphere revitalization system that integrates advanced CO2 removal, O2 recovery, and trace contaminant control processes to improve overall system efficiency. LPCOR will serve as the front end to such a system. LPCOR is a reliable air revitalization technology that can serve both the near-term and long-term human space flight needs of NASA and its commercial partners.

Graphite-Conjugated Rhenium Catalysts for Carbon Dioxide Reduction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oh, Seokjoon; Gallagher, James R.; Miller, Jeffrey T.

2016-02-17

Condensation of fac-Re(5,6-diamino-1,10-phenanthroline)(CO)(3)Cl to o-quinone edge defects on graphitic carbon surfaces generates graphite-conjugated rhenium (GCC-Re) catalysts that are highly active for CO2 reduction to CO in acetonitrile electrolyte. X-ray photo-electron and X-ray absorption spectroscopies establish the formation of surface-bound Re centers with well-defined coordination environments. GCC-Re species on glassy carbon surfaces display catalytic currents greater than 50 mA cm(-2) with 96 +/- 3% Faradaic efficiency for CO production. Normalized for the number of Re active sites, GCC-Re catalysts exhibit higher turnover frequencies than that of a soluble molecular analogue, fac-Re(1,10-phenanthroline)(CO)(3)Cl, and turnover numbers greater than 12,000. In contrast to themore » molecular analogue, GCC-Re surfaces display a Tafel slope of 150 mV/decade, indicative of a catalytic mechanism involving rate-limiting one-electron transfer. This work establishes graphite conjugation as a powerful strategy for generating well-defined, tunable, heterogeneous electrocatalysts on ubiquitous graphitic carbon surfaces.« less

Co-digestion of food waste in a municipal wastewater treatment plant: Comparison of batch tests and full-scale experiences.

PubMed

Koch, Konrad; Plabst, Markus; Schmidt, Andreas; Helmreich, Brigitte; Drewes, Jörg E

2016-01-01

The effects of co-digestion of food waste in a municipal wastewater treatment plant (WWTP) were studied in batch tests. The results obtained were compared with the mass balance of a digester at a full-scale WWTP for a one-year period without and with the addition of co-substrate. The specific methane yield calculated from the balance was 18% higher than the one in the batch tests, suggesting a stimulation of methane generation by co-digestion. It was hypothesized that this increase was caused by shifting the C/N ratio of raw sludge (8.8) to a more favourable ratio of the added food waste (17.7). In addition, potential benefits by adding food waste for energy autarky was investigated. While just 25% of the total energy demand of the plant could be recovered by biogas generation when no co-substrate was fed, this percentage has more than doubled when food waste was added at a ratio of 10% (w/w). Copyright © 2015 Elsevier Ltd. All rights reserved.

Digitizing Medicines for Remote Capture of Oral Medication Adherence Using Co‐encapsulation

PubMed Central

Peloquin, C; Santillo, F; Haubrich, R; Muttera, L; Moser, K; Savage, GM; Benson, CA; Blaschke, TF

2017-01-01

High‐resolution measurement of medication adherence is essential to personalized drug therapy. A US Food and Drug Administration (FDA)‐cleared device, using an edible ingestion sensor (IS), external wearable patch, and paired mobile device can detect and record ingestion events. Oral medications must be combined with an IS to generate precise “digitized‐medication” ingestion records. We developed a Good Manufacturing Practice protocol to repackage oral medications with the IS within certified Capsugel capsules, termed co‐encapsulation (CoE). A randomized bioequivalence study of CoE‐IS‐Rifamate (Isoniazid/Rifampin 150/300 mg) vs. native‐Rifamate was conducted in 12 patients with active Mycobacterium tuberculosis and demonstrated bioequivalence using the population method ratio test (95% confidence interval). Subsequently, CoE‐IS‐medications across all biopharmaceutical classes underwent in vitro dissolution testing utilizing USP and FDA guidelines. CoE‐IS medications tested met USP dissolution specifications and were equivalent to their native formulations. CoE combines oral medications with the IS without altering the quality of the native formulation, generating “digitized” medications for remote capture of dosing histories. PMID:28597911

Origin and distribution of carbon dioxide in the unsaturated zone of the southern High Plains of Texas

USGS Publications Warehouse

Wood, Warren W.; Petraitis, Michael J.

1984-01-01

Partial pressures of CO2, O2, N2, and Ar were monitored at two locations in the Ogallala aquifer system on the Southern High Plains of Texas. Samples were collected monthly during parts of 1980–1981 from nine depths ranging from 0.6 to 36 meters below land surface. PCO2 was observed to be greater at depth than in the active soil zone and thus appears to contradict the normal process in which CO2 is generated in the soil zone and diffuses upward to the atmosphere and downward to the water table. The δ13C of the CO2 gas was quite uniform and averaged −17.9 per mil. PO2 declined with depth, suggesting in situ generation of CO2 by the oxidation of carbon. Several hypotheses were considered to explain the origin of the CO2 at depth. It was concluded that the most probable hypothesis was that dissolved and particulate organic carbon introduced by recharging water was oxidized to CO2 by the aerobic microbial community that utilized oxygen diffusing in from the atmosphere. This hypothesis is consistent with the CO2 concentration profile, calculated production profile of CO2, δ13C values of CO2 gas, caliche, soil humic acid fraction, and dissolved carbonate in groundwater. The abundance of CO2, its concentration profile, and its probable origin provide information for evaluating the observed complex sequence of caliche dissolution and precipitation known to occur in the aquifer.

Synthetic seismic monitoring using reverse-time migration and Kirchhoff migration for CO2 sequestration in Korea

NASA Astrophysics Data System (ADS)

Kim, W.; Kim, Y.; Min, D.; Oh, J.; Huh, C.; Kang, S.

2012-12-01

During last two decades, CO2 sequestration in the subsurface has been extensively studied and progressed as a direct tool to reduce CO2 emission. Commercial projects such as Sleipner, In Salah and Weyburn that inject more than one million tons of CO2 per year are operated actively as well as test projects such as Ketzin to study the behavior of CO2 and the monitoring techniques. Korea also began the CCS (CO2 capture and storage) project. One of the prospects for CO2 sequestration in Korea is the southwestern continental margin of Ulleung basin. To monitor the behavior of CO2 underground for the evaluation of stability and safety, several geophysical monitoring techniques should be applied. Among various geophysical monitoring techniques, seismic survey is considered as the most effective tool. To verify CO2 migration in the subsurface more effectively, seismic numerical simulation is an essential process. Furthermore, the efficiency of the seismic migration techniques should be investigated for various cases because numerical seismic simulation and migration test help us accurately interpret CO2 migration. In this study, we apply the reverse-time migration and Kirchhoff migration to synthetic seismic monitoring data generated for the simplified model based on the geological structures of Ulleung basin in Korea. Synthetic seismic monitoring data are generated for various cases of CO2 migration in the subsurface. From the seismic migration images, we can investigate CO2 diffusion patterns indirectly. From seismic monitoring simulation, it is noted that while the reverse-time migration generates clear subsurface images when subsurface structures are steeply dipping, Kirchhoff migration has an advantage in imaging horizontal-layered structures such as depositional sediments appearing in the continental shelf. The reverse-time migration and Kirchhoff migration present reliable subsurface images for the potential site characterized by stratigraphical traps. In case of vertical CO2 migration at injection point, the reverse time migration yields better images than Kirchhoff migration does. On the other hand, Kirchhoff migration images horizontal CO2 migration clearer than the reverse time migration does. From these results, we can conclude that the reverse-time migration and Kirchhoff migration can complement with each other to describe the behavior of CO2 in the subsurface. Acknowledgement This work was financially supported by the Brain Korea 21 project of Energy Systems Engineering, the "Development of Technology for CO2 Marine Geological Storage" program funded by the Ministry of Land, Transport and Maritime Affairs (MLTM) of Korea and the Korea CCS R&D Center (KCRC) grant funded by the Korea government (Ministry of Education, Science and Technology) (No. 2012-0008926).

Interface roughness induced asymmetric magnetic property in sputter-deposited Co/CoO/Co exchange coupled trilayers

NASA Astrophysics Data System (ADS)

Wang, J.; Sannomiya, T.; Shi, J.; Nakamura, Y.

2012-04-01

The effect of interface roughness on magnetic properties of exchange coupled polycrystalline Co/CoO(tAF)/Co trilayers has been investigated by varying antiferromagnetic layer (CoO) thickness. It has been found that the upper CoO/Co interface becomes rougher with increasing CoO layer thickness, resulting in stronger exchange bias of the upper interface than the lower one. The interfacial exchange coupling is strengthened by the increase of defect-generated uncompensated antiferromagnetic spins; such spins form coupling with spins in the Co layer at the interface. As a result, the CoO layer thickness dependence of exchange bias is much enhanced for the upper Co layer. The transition from anisotropic magnetoresistance to isotropic magnetoresistance for the top Co layer has also been found. This could be attributed to the defects, probably partial thin oxide layers, between Co grains in the top Co layer that leads a switch from spin-orbit scattering related magnetoresistance to spin-dependent electron scattering dominated magnetoresistance.

Bis(2,2′-bipyridyl-κ2 N,N′)(carbonato-κ2 O,O′)cobalt(III) bromide trihydrate

PubMed Central

Ma, Peng-Tao; Wang, Yu-Xia; Zhang, Guo-Qian; Li, Ming-Xue

2008-01-01

The title complex, [Co(CO3)(C10H8N2)2]Br·3H2O, is isostructural with the chloride analogue. The six-coordinated octahedral [Co(2,2′-bipy)2CO3]+ cation (2,2′-bipy is 2,2′-bipyrid­yl), bromide ion and water mol­ecules are linked together via O—H⋯Br and O—H⋯O hydrogen bonds, generating a one-dimensional chain. PMID:21200495

Technical note: A linear model for predicting δ13 Cprotein.

PubMed

Pestle, William J; Hubbe, Mark; Smith, Erin K; Stevenson, Joseph M

2015-08-01

Development of a model for the prediction of δ(13) Cprotein from δ(13) Ccollagen and Δ(13) Cap-co . Model-generated values could, in turn, serve as "consumer" inputs for multisource mixture modeling of paleodiet. Linear regression analysis of previously published controlled diet data facilitated the development of a mathematical model for predicting δ(13) Cprotein (and an experimentally generated error term) from isotopic data routinely generated during the analysis of osseous remains (δ(13) Cco and Δ(13) Cap-co ). Regression analysis resulted in a two-term linear model (δ(13) Cprotein (%) = (0.78 × δ(13) Cco ) - (0.58× Δ(13) Cap-co ) - 4.7), possessing a high R-value of 0.93 (r(2)  = 0.86, P < 0.01), and experimentally generated error terms of ±1.9% for any predicted individual value of δ(13) Cprotein . This model was tested using isotopic data from Formative Period individuals from northern Chile's Atacama Desert. The model presented here appears to hold significant potential for the prediction of the carbon isotope signature of dietary protein using only such data as is routinely generated in the course of stable isotope analysis of human osseous remains. These predicted values are ideal for use in multisource mixture modeling of dietary protein source contribution. © 2015 Wiley Periodicals, Inc.

High-order harmonic generation of CO and N2 molecules under linearly- and bi circularly-polarized laser pulses by TD-DFT

NASA Astrophysics Data System (ADS)

Koushki, A. M.; Sadighi-Bonabi, R.; Mohsen-Nia, M.; Irani, E.

2018-07-01

We present a method for high-order harmonics generation of N2 and CO molecules under two-color circularly polarized counter-rotating laser pulses at frequencies of and 2. Pulse envelope in this investigation is sin-squared and the intensity of each laser beam is with ten-optical cycle (o.c.). We show that an isolated pulse with a pulse duration shorter than 20 attosecond from the superposition of several harmonics can be generated. Both two-color linearly- and bicircularly-polarized laser pulses are considered. Our results have also been compared with the outcomes of the previous theoretical works as well as experiment observations. It is found that for CO molecule, the bicircularly-polarized laser pulses are superior and more efficient, and it can generate narrower attosecond pulses than the linearly-polarized pulses. While for N2 molecule, the two-color linearly-polarized pulses are more efficient, and it can generate narrower attosecond pulses than the bicircularly-polarized pulses. Furthermore, in order to demonstrate the origin of red- and blue-shifts in high-harmonic spectra, the effect of pulse duration on the high-order harmonics spectra is investigated. In addition, to obtain imaging on the temporal dependence of the electron densities, the time dependent electron localization function is used. Moreover, in order to study of the quantum trajectory of electrons, time-frequency analysis is utilized.

4. DETAIL OF GEARWELL AND GENERATOR, WEST VIEW. Vanadium ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. DETAIL OF GEARWELL AND GENERATOR, WEST VIEW. - Vanadium Corporation of America (VCA) Naturita Mill, Grinding Rod Mill, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

The Value of CO2-Geothermal Bulk Energy Storage to Reducing CO2 Emissions Compared to Conventional Bulk Energy Storage Technologies

NASA Astrophysics Data System (ADS)

Ogland-Hand, J.; Bielicki, J. M.; Buscheck, T. A.

2016-12-01

Sedimentary basin geothermal resources and CO2 that is captured from large point sources can be used for bulk energy storage (BES) in order to accommodate higher penetration and utilization of variable renewable energy resources. Excess energy is stored by pressurizing and injecting CO2 into deep, porous, and permeable aquifers that are ubiquitous throughout the United States. When electricity demand exceeds supply, some of the pressurized and geothermally-heated CO2 can be produced and used to generate electricity. This CO2-BES approach reduces CO2 emissions directly by storing CO2 and indirectly by using some of that CO2 to time-shift over-generation and displace CO2 emissions from fossil-fueled power plants that would have otherwise provided electricity. As such, CO2-BES may create more value to regional electricity systems than conventional pumped hydro energy storage (PHES) or compressed air energy storage (CAES) approaches that may only create value by time-shifting energy and indirectly reducing CO2 emissions. We developed and implemented a method to estimate the value that BES has to reducing CO2 emissions from regional electricity systems. The method minimizes the dispatch of electricity system components to meet exogenous demand subject to various CO2 prices, so that the value of CO2 emissions reductions can be estimated. We applied this method to estimate the performance and value of CO2-BES, PHES, and CAES within real data for electricity systems in California and Texas over the course of a full year to account for seasonal fluctuations in electricity demand and variable renewable resource availability. Our results suggest that the value of CO2-BES to reducing CO2 emissions may be as much as twice that of PHES or CAES and thus CO2-BES may be a more favorable approach to energy storage in regional electricity systems, especially those where the topography is not amenable to PHES or the subsurface is not amenable to CAES.

Conversion of 4-Hydroxybutyrate to Acetyl Coenzyme A and Its Anapleurosis in the Metallosphaera sedula 3-Hydroxypropionate/4-Hydroxybutyrate Carbon Fixation Pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hawkins, AB; Adams, MWW; Kelly, RM

2014-03-25

The extremely thermoacidophilic archaeon Metallosphaera sedula (optimum growth temperature, 73 degrees C, pH 2.0) grows chemolithoautotrophically on metal sulfides or molecular hydrogen by employing the 3-hydroxypropionate/4-hydroxybutyrate (3HP/4HB) carbon fixation cycle. This cycle adds two CO2 molecules to acetyl coenzyme A (acetyl-CoA) to generate 4HB, which is then rearranged and cleaved to form two acetyl-CoA molecules. Previous metabolic flux analysis showed that two-thirds of central carbon precursor molecules are derived from succinyl-CoA, which is oxidized to malate and oxaloacetate. The remaining one-third is apparently derived from acetyl-CoA. As such, the steps beyond succinyl-CoA are essential for completing the carbon fixation cyclemore » and for anapleurosis of acetyl-CoA. Here, the final four enzymes of the 3HP/4HB cycle, 4-hydroxybutyrate-CoA ligase (AMP forming) (Msed_0406), 4-hydroxybutyryl-CoA dehydratase (Msed_1321), crotonyl-CoA hydratase/(S)-3-hydroxybutyryl-CoA dehydrogenase (Msed_0399), and acetoacetyl-CoA beta-ketothiolase (Msed_0656), were produced recombinantly in Escherichia coli, combined in vitro, and shown to convert 4HB to acetyl-CoA. Metabolic pathways connecting CO2 fixation and central metabolism were examined using a gas-intensive bioreactor system in which M. sedula was grown under autotrophic (CO2-limited) and heterotrophic conditions. Transcriptomic analysis revealed the importance of the 3HP/4HB pathway in supplying acetyl-CoA to anabolic pathways generating intermediates in M. sedula metabolism. The results indicated that flux between the succinate and acetyl-CoA branches in the 3HP/4HB pathway is governed by 4-hydroxybutyrate-CoA ligase, possibly regulated posttranslationally by the protein acetyltransferase (Pat)/Sir2-dependent system. Taken together, this work confirms the final four steps of the 3HP/4HB pathway, thereby providing the framework for examining connections between CO2 fixation and central metabolism in M. sedula.« less

Measurement of total organic concentration in water

NASA Technical Reports Server (NTRS)

Winkler, E.

1978-01-01

Instrument for determining total organic concentration in water uses no corrosive reagents or gases. Instead continuous ultraviolet photolysis process converts organic compounds to carbon dioxide (CO2). CO2 electrode is used to measure CO2 content. Only reagent necessary is oxygen, generated in situ by electrolyzing some water. In addition to application in aerospace industry, system has potential uses in pollution monitoring and in laboratory analyses.

Functional reconstitution of the Mycobacterium tuberculosis long-chain acyl-CoA carboxylase from multiple acyl-CoA subunits.

PubMed

Bazet Lyonnet, Bernardo; Diacovich, Lautaro; Gago, Gabriela; Spina, Lucie; Bardou, Fabienne; Lemassu, Anne; Quémard, Annaïk; Gramajo, Hugo

2017-04-01

Mycobacterium tuberculosis produces a large number of structurally diverse lipids that have been implicated in the pathogenicity, persistence and antibiotic resistance of this organism. Most building blocks involved in the biosynthesis of all these lipids are generated by acyl-CoA carboxylases whose subunit composition and physiological roles have not yet been clearly established. Inconclusive data in the literature refer to the exact protein composition and substrate specificity of the enzyme complex that produces the long-chain α-carboxy-acyl-CoAs, which are substrates involved in the last step of condensation mediated by the polyketide synthase 13 to synthesize mature mycolic acids. Here we have successfully reconstituted the long-chain acyl-CoA carboxylase (LCC) complex from its purified components, the α subunit (AccA3), the ε subunit (AccE5) and the two β subunits (AccD4 and AccD5), and demonstrated that the four subunits are essential for its activity. Furthermore, we also showed by substrate competition experiments and the use of a specific inhibitor that the AccD5 subunit's role in the carboxylation of the long acyl-CoAs, as part of the LCC complex, was structural rather than catalytic. Moreover, AccD5 was also able to carboxylate its natural substrates, acetyl-CoA and propionyl-CoA, in the context of the LCC enzyme complex. Thus, the supercomplex formed by these four subunits has the potential to generate the main substrates, malonyl-CoA, methylmalonyl-CoA and α-carboxy-C 24-26 -CoA, used as condensing units for the biosynthesis of all the lipids present in this pathogen. © 2017 Federation of European Biochemical Societies.

Nickel(0) nanoparticles supported on bare or coated cobalt ferrite as highly active, magnetically isolable and reusable catalyst for hydrolytic dehydrogenation of ammonia borane.

PubMed

Manna, Joydev; Akbayrak, Serdar; Özkar, Saim

2017-12-15

Nickel(0) nanoparticles supported on cobalt ferrite (Ni 0 /CoFe 2 O 4 ), polydopamine coated cobalt ferrite (Ni 0 /PDA-CoFe 2 O 4 ) or silica coated cobalt ferrite (Ni 0 /SiO 2 -CoFe 2 O 4 ) are prepared and used as catalysts in hydrogen generation from the hydrolysis of ammonia borane at room temperature. Ni 0 /CoFe 2 O 4 (4.0% wt. Ni) shows the highest catalytic activity with a TOF value of 38.3min -1 in hydrogen generation from the hydrolysis of ammonia borane at 25.0±0.1°C. However, the initial catalytic activity of Ni 0 /CoFe 2 O 4 catalyst is not preserved in subsequent runs of hydrolysis. Coating the surface of cobalt ferrite support with polydopamine or silica leads to a significant improvement in the stability of catalysts. The TOF values of Ni 0 /PDA-CoFe 2 O 4 and Ni 0 /SiO 2 -CoFe 2 O 4 are found to be 7.6 and 5.3min -1 , respectively, at 25.0±0.1°C. Ni 0 /PDA-CoFe 2 O 4 catalyst shows high reusability as compared to the Ni 0 /CoFe 2 O 4 and Ni 0 /SiO 2 -CoFe 2 O 4 catalysts in hydrolytic dehydrogenation of ammonia borane at room temperature. All the catalysts are characterized by using a combination of various advanced analytical techniques. The results reveal that nickel nanoparticles with an average size of 12.3±0.7nm are well dispersed on the surface of PDA-CoFe 2 O 4 . . Copyright © 2017 Elsevier Inc. All rights reserved.

Combustion of Metals in Carbon Dioxide and Reduced-Gravity Environments

NASA Technical Reports Server (NTRS)

Branch, M. C.; Abbud-Madrid, A.; Modak, A.; Dreyer, C. B.; Daily, J. W.

2001-01-01

Ongoing exploration and future mission2001110444 s to Mars have given impetus to research on the use of natural resources of the planet. Since carbon dioxide (CO2) constitutes approximately 95% of the Mars atmosphere and since it reacts directly and vigorously with several metals, this investigation focuses on metal-CO2 reactions as a possible combination for rocket-propellant production and energy generation. Magnesium (Mg) has been initially selected as the metal fuel owing to its low ignition temperature and high specific impulse and burning rate in CO2. Our studies in this field started with low gravity (g) combustion tests of Mg in O2, CO2, and CO. Reduced gravity provided a clear picture of the burning phenomena by eliminating the intrusive buoyant flows in high-temperature metal reactions and by removing the destructive effect of gravity on the shape of molten metal samples. Suspended cylindrical metal samples of 2, 3, and 4-mm in diameter and length were radiatively ignited in low-g to generate free-floating samples exhibiting a spherically symmetric flame with increasing metal-oxide accumulation in an outer shell. For the Mg-CO2 combination, burning times twice as long as in normal-g and five times longer than in Mg-O2 flames were observed, revealing a diffusion-controlled reaction. The burning time is proportional to the square of the sample diameter. In tests conducted with pure CO, combustion was not possible without constant heating of the sample due to the formation of a thick carbon-containing coating around the Mg sample generated by surface reactions. The following work presents two new studies that attempt to explain some of the low-g experimental observations. First, a simplified one-dimensional, quasi-steady numerical model is developed to obtain temperature, species concentrations, and burning rates of the spherically symmetric diffusion flame around the Mg sample burning in O2 and CO2. Second, a Planar Laser Induced Fluorescence (PLIF) technique is implemented to provide spatially resolved measurements of magnesium oxide (MgO) in the reaction zone of Mg samples burning in O2 and CO2. These experiments reveal fundamental differences between the two combustion systems.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haidar, S. M., E-mail: haidar@imr.tohoku.ac.jp; Iguchi, R.; Yagmur, A.

We have investigated dc voltage generation induced by ferromagnetic resonance in a Co{sub 75}Fe{sub 25}/Pt film. In order to reduce rectification effects of anisotropic magnetoresistance and the planar Hall effect, which may be observed simultaneously with the inverse spin Hall effect, we selected Co{sub 75}Fe{sub 25} with extremely small anisotropic magnetoresistance as a spin injector. Using the difference in the spectral shape of voltage and in the angle dependence of in-plane magnetization among the effects, we demonstrated that the generated dc voltage is governed by the inverse spin Hall effect induced by spin pumping.

3D Printing: 3D Printing of Conductive Complex Structures with In Situ Generation of Silver Nanoparticles (Adv. Mater. 19/2016).

PubMed

Fantino, Erika; Chiappone, Annalisa; Roppolo, Ignazio; Manfredi, Diego; Bongiovanni, Roberta; Pirri, Candido Fabrizio; Calignano, Flaviana

2016-05-01

On page 3712, E. Fantino, A. Chiappone, and co-workers fabricate conductive 3D hybrid structures by coupling the photo-reduction of metal precursors with 3D printing technology. The generated structures consist of metal nanoparticles embedded in a polymer matrix shaped into complex multilayered architectures. 3D conductive structures are fabricated with a digital light-processing printer incorporating silver salt into photocurable formulations. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Regenerative Life Support Systems (RLSS) test bed performance - Characterization of plant performance in a controlled atmosphere

NASA Technical Reports Server (NTRS)

Edeen, Marybeth; Henninger, Donald

1991-01-01

By growing higher plants for food, lunar and Martian manned habitats will not only reduce resupply requirements but obtain CO2 removal and both oxygen-production and water-reclamation requirements. Plants have been grown in the RLSS at NASA-Johnson in order to quantitatively evaluate plant CO2 accumulation, O2 generation, evapotranspiration, trace-contaminant generation, and biomass productivity. Attention is presently given to test conditions and anomalies in these RLSS trials; areas where performance must be improved have been identified.

EDUCATION LEVEL IS GREATEST RISK-FACTOR IN CARBON MONOXIDE POISONING

EPA Science Inventory

Carbon monoxide (CO) is a toxic by-product of the combustion of fossil fuels. In confined spaces, inefficient combustion sources, such as furnaces, stoves, kerosene heaters and automobiles can generate levels of CO that interrupt oxygen transport throughout the body, potentially ...

77 FR 6791 - Combined Notice of Filings #2

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-09

... Generation Company, Entergy Nuclear Power Marketing, LLC, Entergy Nuclear Vermont Yankee, LLC, Entergy...: Ethical Electric Benefit Co. Description: Ethical Electric Benefit Co. Market Based Rate Filing--Clone to...: Michigan Electric Transmission Company. Description: Filing of Certificate of Concurrence to be effective 2...

Performance and emissions of a spark-ignited engine driven generator on biomass based syngas.

PubMed

Shah, Ajay; Srinivasan, Radhakrishnan; To, Suminto D Filip; Columbus, Eugene P

2010-06-01

The emergence of biomass based energy warrants the evaluation of syngas from biomass gasification as a fuel for personal power systems. The objectives of this study were to determine the performance and exhaust emissions of a commercial 5.5 kW generator modified for operation with 100% syngas at different syngas flows and to compare the results with those obtained for gasoline operation at same electrical power. The maximum electrical power output for syngas operation was 1392 W and that for gasoline operation was 2451 W. However, the overall efficiency of the generator at maximum electrical power output for both the fuels were found to be the same. The concentrations of CO and NO(x) in the generator exhaust were lower for the syngas operation, respectively by 30-96% and 54-84% compared to the gasoline operation. However, the concentrations of CO(2) in the generator exhaust were significantly higher by 33-167% for the syngas operation. (c) 2010 Elsevier Ltd. All rights reserved.

SCALS: a fourth-generation study of assisted living technologies in their organisational, social, political and policy context.

PubMed

Greenhalgh, Trisha; Shaw, Sara; Wherton, Joe; Hughes, Gemma; Lynch, Jenni; A'Court, Christine; Hinder, Sue; Fahy, Nick; Byrne, Emma; Finlayson, Alexander; Sorell, Tom; Procter, Rob; Stones, Rob

2016-02-15

Research to date into assisted living technologies broadly consists of 3 generations: technical design, experimental trials and qualitative studies of the patient experience. We describe a fourth-generation paradigm: studies of assisted living technologies in their organisational, social, political and policy context. Fourth-generation studies are necessarily organic and emergent; they view technology as part of a dynamic, networked and potentially unstable system. They use co-design methods to generate and stabilise local solutions, taking account of context. SCALS (Studies in Co-creating Assisted Living Solutions) consists (currently) of 5 organisational case studies, each an English health or social care organisation striving to introduce technology-supported services to support independent living in people with health and/or social care needs. Treating these cases as complex systems, we seek to explore interdependencies, emergence and conflict. We employ a co-design approach informed by the principles of action research to help participating organisations establish, refine and evaluate their service. To that end, we are conducting in-depth ethnographic studies of people's experience of assisted living technologies (micro level), embedded in evolving organisational case studies that use interviews, ethnography and document analysis (meso level), and exploring the wider national and international context for assisted living technologies and policy (macro level). Data will be analysed using a sociotechnical framework developed from structuration theory. Research ethics approval for the first 4 case studies has been granted. An important outcome will be lessons learned from individual co-design case studies. We will document the studies' credibility and rigour, and assess the transferability of findings to other settings while also recognising unique aspects of the contexts in which they were generated. Academic outputs will include a cross-case analysis and progress in theory and method of fourth-generation assisted living technology research. We will produce practical guidance for organisations, policymakers, designers and service users. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Invasion fitness for gene-culture co-evolution in family-structured populations and an application to cumulative culture under vertical transmission.

PubMed

Mullon, Charles; Lehmann, Laurent

2017-08-01

Human evolution depends on the co-evolution between genetically determined behaviors and socially transmitted information. Although vertical transmission of cultural information from parent to offspring is common in hominins, its effects on cumulative cultural evolution are not fully understood. Here, we investigate gene-culture co-evolution in a family-structured population by studying the invasion fitness of a mutant allele that influences a deterministic level of cultural information (e.g., amount of knowledge or skill) to which diploid carriers of the mutant are exposed in subsequent generations. We show that the selection gradient on such a mutant, and the concomitant level of cultural information it generates, can be evaluated analytically under the assumption that the cultural dynamic has a single attractor point, thereby making gene-culture co-evolution in family-structured populations with multigenerational effects mathematically tractable. We apply our result to study how genetically determined phenotypes of individual and social learning co-evolve with the level of adaptive information they generate under vertical transmission. We find that vertical transmission increases adaptive information due to kin selection effects, but when information is transmitted as efficiently between family members as between unrelated individuals, this increase is moderate in diploids. By contrast, we show that the way resource allocation into learning trades off with allocation into reproduction (the "learning-reproduction trade-off") significantly influences levels of adaptive information. We also show that vertical transmission prevents evolutionary branching and may therefore play a qualitative role in gene-culture co-evolutionary dynamics. More generally, our analysis of selection suggests that vertical transmission can significantly increase levels of adaptive information under the biologically plausible condition that information transmission between relatives is more efficient than between unrelated individuals. Copyright © 2017 Elsevier Inc. All rights reserved.

Long-term dynamics of adaptive evolution in a globally important phytoplankton species to ocean acidification

PubMed Central

Schlüter, Lothar; Lohbeck, Kai T.; Gröger, Joachim P.; Riebesell, Ulf; Reusch, Thorsten B. H.

2016-01-01

Marine phytoplankton may adapt to ocean change, such as acidification or warming, because of their large population sizes and short generation times. Long-term adaptation to novel environments is a dynamic process, and phenotypic change can take place thousands of generations after exposure to novel conditions. We conducted a long-term evolution experiment (4 years = 2100 generations), starting with a single clone of the abundant and widespread coccolithophore Emiliania huxleyi exposed to three different CO2 levels simulating ocean acidification (OA). Growth rates as a proxy for Darwinian fitness increased only moderately under both levels of OA [+3.4% and +4.8%, respectively, at 1100 and 2200 μatm partial pressure of CO2 (Pco2)] relative to control treatments (ambient CO2, 400 μatm). Long-term adaptation to OA was complex, and initial phenotypic responses of ecologically important traits were later reverted. The biogeochemically important trait of calcification, in particular, that had initially been restored within the first year of evolution was later reduced to levels lower than the performance of nonadapted populations under OA. Calcification was not constitutively lost but returned to control treatment levels when high CO2–adapted isolates were transferred back to present-day control CO2 conditions. Selection under elevated CO2 exacerbated a general decrease of cell sizes under long-term laboratory evolution. Our results show that phytoplankton may evolve complex phenotypic plasticity that can affect biogeochemically important traits, such as calcification. Adaptive evolution may play out over longer time scales (>1 year) in an unforeseen way under future ocean conditions that cannot be predicted from initial adaptation responses. PMID:27419227

Power-Generation Characteristics After Vibration and Thermal Stresses of Thermoelectric Unicouples with CoSb3/Ti/Mo(Cu) Interfaces

NASA Astrophysics Data System (ADS)

Bae, Kwang Ho; Choi, Soon-Mok; Kim, Kyung-Hun; Choi, Hyoung-Seuk; Seo, Won-Seon; Kim, Il-Ho; Lee, Soonil; Hwang, Hae Jin

2015-06-01

Reliability tests for thermoelectric unicouples were carried out to investigate the adhesion properties of CoSb3/Ti/Mo(Cu) interfaces. The n-type In0.25 Co3.95Ni0.05Sb12 and p-type In0.25Co3FeSb12 bulks were prepared for fabricating a thermoelectric unicouple (one p- n couple) by an induction melting and a spark plasma sintering process. Mo-Cu alloy was selected as an electrode for the unicouples due to its high melting temperature and proper work function value. Many thermoelectric unicouples with the CoSb3/Ti/Mo(Cu) interfaces were fabricated with the proper brazing materials by means of a repeated firing process. Reliability of the unicouples with the interfaces was evaluated by a vibration test and a thermal cycling test. After the thermal cycling and vibration tests, the power-generation characteristics of the unicouples were compared with the unicouples before the tests. Even after the vibration test, electrical power with a power density of 0.5 W/cm2 was generated. The Ti-interlayer is considered as a possible candidate for making a reliable unicouple with high adhesion strength. With the thermal cycling test, the resistance of the unicouple increased and the electrical power from the unicouple decreased. A failure mode by the thermal cycling test was ascribed to a complex effect of micro-cracks originated from the thermal stress and oxidation problem of the thermoelectric materials; that is, a thick oxide layer more than 300 μm was detected after a high-temperature durability test of n-type In0.25Co3.95Ni0.05Sb12 material at 773 K in air for 7 days.

The acid and alkalinity budgets of weathering in the Andes-Amazon system: Insights into the erosional control of global biogeochemical cycles

NASA Astrophysics Data System (ADS)

Torres, Mark A.; West, A. Joshua; Clark, Kathryn E.; Paris, Guillaume; Bouchez, Julien; Ponton, Camilo; Feakins, Sarah J.; Galy, Valier; Adkins, Jess F.

2016-09-01

The correlation between chemical weathering fluxes and denudation rates suggests that tectonic activity can force variations in atmospheric pCO2 by modulating weathering fluxes. However, the effect of weathering on pCO2 is not solely determined by the total mass flux. Instead, the effect of weathering on pCO2 also depends upon the balance between 1) alkalinity generation by carbonate and silicate mineral dissolution and 2) sulfuric acid generation by the oxidation of sulfide minerals. In this study, we explore how the balance between acid and alkalinity generation varies with tectonic uplift to better understand the links between tectonics and the long-term carbon cycle. To trace weathering reactions across the transition from the Peruvian Andes to the Amazonian foreland basin, we measured a suite of elemental concentrations (Na, K, Ca, Mg, Sr, Si, Li, SO4, and Cl) and isotopic ratios (87Sr/86Sr and δ34S) on both dissolved and solid phase samples. Using an inverse model, we quantitatively link systematic changes in solute geochemistry with elevation to downstream declines in sulfuric acid weathering as well as the proportion of cations sourced from silicates. With a new carbonate-system framework, we show that weathering in the Andes Mountains is a CO2 source whereas foreland weathering is a CO2 sink. These results are consistent with the theoretical expectation that the ratio of sulfide oxidation to silicate weathering increases with increasing erosion. Altogether, our results suggest that the effect of tectonically-enhanced weathering on atmospheric pCO2 is strongly modulated by sulfide mineral oxidation.

Faculty as Bridges to Co-Curricular Engagement and Community for First-Generation International Students

ERIC Educational Resources Information Center

Glass, Chris R.; Gesing, Peggy; Hales, Angela; Cong, Cong

2017-01-01

The proportion of first-generation international students at US institutions ranges from one-tenth to one-half of the total international student body. First-generation status is an underexplored, and potentially significant, demographic factor in international students' adaptation to college. Researchers used structural equation modelling (SEM)…

40 CFR 52.1689 - Original Identification of plan section.

Code of Federal Regulations, 2014 CFR

2014-07-01

... percent, by weight, for the Long Island Lighting Co.'s Northport Generating Facility (Units 1, 2, and 3... oil limitation to 1.0 percent, by weight, for the Long Island Lighting Company's Glenwood Generating... of New York, Inc. Arthur Kill generating facility, units 2 and 3, Staten Island, New York and...

40 CFR 52.1689 - Original Identification of plan section.

Code of Federal Regulations, 2013 CFR

2013-07-01

... percent, by weight, for the Long Island Lighting Co.'s Northport Generating Facility (Units 1, 2, and 3... oil limitation to 1.0 percent, by weight, for the Long Island Lighting Company's Glenwood Generating... of New York, Inc. Arthur Kill generating facility, units 2 and 3, Staten Island, New York and...

40 CFR 52.1689 - Original identification of plan section.

Code of Federal Regulations, 2012 CFR

2012-07-01

... percent, by weight, for the Long Island Lighting Co.'s Northport Generating Facility (Units 1, 2, and 3... oil limitation to 1.0 percent, by weight, for the Long Island Lighting Company's Glenwood Generating... of New York, Inc. Arthur Kill generating facility, units 2 and 3, Staten Island, New York and...

An algorithm to generate input data from meteorological and space shuttle observations to validate a CH4-CO model

NASA Technical Reports Server (NTRS)

Peters, L. K.; Yamanis, J.

1981-01-01

Objective procedures to analyze data from meteorological and space shuttle observations to validate a three dimensional model were investigated. The transport and chemistry of carbon monoxide and methane in the troposphere were studied. Four aspects were examined: (1) detailed evaluation of the variational calculus procedure, with the equation of continuity as a strong constraint, for adjustment of global tropospheric wind fields; (2) reduction of the National Meteorological Center (NMC) data tapes for data input to the OSTA-1/MAPS Experiment; (3) interpolation of the NMC Data for input to the CH4-CO model; and (4) temporal and spatial interpolation procedures of the CO measurements from the OSTA-1/MAPS Experiment to generate usable contours of the data.

Study on depth profile of heavy ion irradiation effects in poly(tetrafluoroethylene-co-ethylene)

NASA Astrophysics Data System (ADS)

Gowa, Tomoko; Shiotsu, Tomoyuki; Urakawa, Tatsuya; Oka, Toshitaka; Murakami, Takeshi; Oshima, Akihiro; Hama, Yoshimasa; Washio, Masakazu

2011-02-01

High linear energy transfer (LET) heavy ion beams were used to irradiate poly(tetrafluoroethylene-co-ethylene) (ETFE) under vacuum and in air. The irradiation effects in ETFE as a function of the depth were precisely evaluated by analyzing each of the films of the irradiated samples, which were made of stacked ETFE films. It was indicated that conjugated double bonds were generated by heavy ion beam irradiation, and their amounts showed the Bragg-curve-like distributions. Also, it was suggested that higher LET beams would induce radical formation in high density and longer conjugated C=C double bonds could be generated by the second-order reactions. Moreover, for samples irradiated in air, C=O was produced correlating to the yield of oxygen molecules diffusing from the sample surface.

Development of Residential SOFC Cogeneration System

NASA Astrophysics Data System (ADS)

Ono, Takashi; Miyachi, Itaru; Suzuki, Minoru; Higaki, Katsuki

2011-06-01

Since 2001 Kyocera has been developing 1kW class Solid Oxide Fuel Cell (SOFC) for power generation system. We have developed a cell, stack, module and system. Since 2004, Kyocera and Osaka Gas Co., Ltd. have been developed SOFC residential co-generation system. From 2007, we took part in the "Demonstrative Research on Solid Oxide Fuel Cells" Project conducted by New Energy Foundation (NEF). Total 57 units of 0.7kW class SOFC cogeneration systems had been installed at residential houses. In spite of residential small power demand, the actual electric efficiency was about 40%(netAC,LHV), and high CO2 reduction performance was achieved by these systems. Hereafter, new joint development, Osaka Gas, Toyota Motors, Kyocera and Aisin Seiki, aims early commercialization of residential SOFC CHP system.

12. LAUNCH CONTROL SUPPORT BUILDING. INTERIOR OF GENERATOR ROOM. VIEW ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. LAUNCH CONTROL SUPPORT BUILDING. INTERIOR OF GENERATOR ROOM. VIEW TO EAST. - Minuteman III ICBM Launch Control Facility November-1, 1.5 miles North of New Raymer & State Highway 14, New Raymer, Weld County, CO

Fiber optic Cerenkov radiation sensor system to estimate burn-up of spent fuel: characteristic evaluation of the system using Co-60 source

NASA Astrophysics Data System (ADS)

Shin, S. H.; Jang, K. W.; Jeon, D.; Hong, S.; Kim, S. G.; Sim, H. I.; Yoo, W. J.; Park, B. G.; Lee, B.

2013-09-01

Cerenkov radiation occurs when charged particles are moving faster than the speed of light in a transparent dielectric medium. In optical fibers, the Cerenkov light also can be generated due to their dielectric components. Accordingly, the radiation-induced light signals can be obtained using optical fibers without any scintillating material. In this study, to measure the intensities of Cerenkov radiation induced by gamma-rays, we have fabricated the fiber-optic Cerenkov radiation sensor system using silica optical fibers, plastic optical fibers, multi-anode photomultiplier tubes, and a scanning system. To characterize the Cerenkov radiation generated in optical fibers, the spectra of Cerenkov radiation generated in the silica and plastic optical fibers were measured. Also, the intensities of Cerenkov radiation induced by gamma-rays generated from a cylindrical Co-60 source with or without lead shielding were measured using the fiberoptic Cerenkov radiation sensor system.

Pictures of Processes: Automated Graph Rewriting for Monoidal Categories and Applications to Quantum Computing

NASA Astrophysics Data System (ADS)

Kumar, Bhupendra

Light assisted or driven fuel generation by carbon dioxide and proton reduction can be achieved by a p-type semiconductor/liquid junction. There are four different types of schemes which are typically used for carbon dioxide and proton reduction for fuel generation applications. In these systems, the semiconductor can serve the dual role of a catalyst and a light absorber. Specific electrocatalysts (heterogeneous and homogeneous) can be driven by p-type semiconductor where it works only as light absorber in order to achieve better selectivity and faster rates of catalysis. The p-type semiconductor/molecular catalyst junction is primarily explored in this dissertation for CO2 and proton photoelectrochemical reduction. A general principle for the operation of p-type semiconductor/molecular junctions is proposed and validated for several molecular catalysts in contact with p-Si photocathode. It is also shown that the light assisted homogeneous and heterogeneous catalysis can coexist. This principle is extended to achieve direct conversion of CO 2 to methanol on Platinum nanoparticles decorated p-Si in aqueous medium through pyridine/pyridinium system for CO2 reduction. An open circuit voltage higher than 600 mV is achieved for p-Si/Re(bipy-tBu)(CO) 3Cl [where bipy-tBu = 4,4'- tert-butyl-2,2'-bipyridine] (Re-catalyst) junction. The photoelectrochemical conversion of CO2 to CO using a p-Si/Re-catalyst junction is obtained at 100 % Faradaic efficiency. The homogeneous catalytic current density for CO2 by p-Si/Re-catalyst junction under illumination scales linearly with illumination intensity (both polychromatic and monochromatic). This indicates that the homogeneous catalysis is light driven for the p-Si/Re-catalyst junction system up to light intensities approaching one sun. The photoelectrochemical reduction of other active members of Re(bipyridyl)(CO)3Cl molecular catalyst family is also observed on illuminated p-Si photocathode. Effects of surface modification and nanowire morphology of the p-Si photocathode on the homogeneous catalytic reduction of CO2 by using p-Si/Re-catalyst junction are also described in this dissertation. For phenyl ethyl modified p-Si photocathode, the rate of homogeneous catalysis for CO2 reduction by Re-catalyst is three times greater than glassy carbon electrode and six times greater than the hexyl modified and the hydrogen terminated p-Si photocathodes. When hexyl modified p-Si nanowires are used as photocathode, the homogeneous catalytic current density increased by a factor of two compared to planar p-Si (both freshly etched and hexyl modified) photocathode. A successful light assisted generation of syngas (H2:CO = 2:1) from CO2 and water is achieved by using p-Si/Re-catalyst. In this system, water is reduced heterogeneously on p-Si surface and CO2 is reduced homogeneously by Re-catalyst. The same principle is extended to the homogeneous proton reduction by using p-Si/[FeFe] complex junction where [FeFe] complex [Fe2(micro-bdt)(CO) 6] (bdt = benzene-1,2-dithiolate)] is a proton reduction molecular catalyst. A short circuit quantum efficiency of 79 % with 100 % Faradaic efficiency and 600 mV open circuit are achieved by using p-Si/[FeFe] complex for proton reduction with 300 mM perchloric acid as a proton source. Cobalt difluororyl-diglyoximate (Co-catalyst) is a proton reduction catalyst with only 200 mV of overpotential for the hydrogen evolution reaction (HRE). The Co-catalyst is photoelectrochemically reduced with a photovoltage of 470 mV on illuminated p-Si photocathode. For p-Si photocathodes, the overpotential for proton reduction is over 1 V. In principle, p-Si/Co-catalyst junction can reduce proton to hydrogen homogeneously at underpotential. In a concluding effort, a wireless monolithic dual face single photoelectrode (multi junction photovoltaic cell which can generate a voltage higher 1.7 V) based photochemical cell is proposed for direct conversion of solar energy into liquid fuel. In this device, the two faces of the multijunction photoelectrode are serve as an anode and a cathode for water oxidation and fuel generation, respectively, and are separated by proton exchange membrane.

Stable isotope labeling by essential nutrients in cell culture for preparation of labeled coenzyme A and its thioesters.

PubMed

Basu, Sankha S; Mesaros, Clementina; Gelhaus, Stacy L; Blair, Ian A

2011-02-15

Stable isotope dilution mass spectrometry (MS) represents the gold standard for quantification of endogenously formed cellular metabolites. Although coenzyme A (CoA) and acyl-CoA thioester derivatives are central players in numerous metabolic pathways, the lack of a commercially available isotopically labeled CoA limits the development of rigorous MS-based methods. In this study, we adapted stable isotope labeling by amino acids in cell culture (SILAC) methodology to biosynthetically generate stable isotope labeled CoA and thioester analogues for use as internal standards in liquid chromatography/multiple reaction monitoring mass spectrometry (LC/MRM-MS) assays. This was accomplished by incubating murine hepatocytes (Hepa 1c1c7) in media in which pantothenate (a precursor of CoA) was replaced with [(13)C(3)(15)N(1)]-pantothenate. Efficient incorporation into various CoA species was optimized to >99% [(13)C(3)(15)N(1)]-pantothenate after three passages of the murine cells in culture. Charcoal-dextran-stripped fetal bovine serum (FBS) was found to be more efficient for serum supplementation than dialyzed or undialyzed FBS, due to lower contaminating unlabeled pantothenate content. Stable isotope labeled CoA species were extracted and utilized as internal standards for CoA thioester analysis in cell culture models. This methodology of stable isotope labeling by essential nutrients in cell culture (SILEC) can serve as a paradigm for using vitamins and other essential nutrients to generate stable isotope standards that cannot be readily synthesized.

Hydrogenation of CO 2 to methanol: Importance of metal–oxide and metal–carbide interfaces in the activation of CO 2

DOE PAGES

Rodriguez, José A.; Liu, Ping; Stacchiola, Dario J.; ...

2015-09-30

In this study, the high thermochemical stability of CO 2 makes it very difficult to achieve the catalytic conversion of the molecule into alcohols or other hydrocarbon compounds, which can be used as fuels or the starting point for the generation of fine chemicals. Pure metals and bimetallic systems used for the CO 2 → CH 3OH conversion usually bind CO 2 too weakly and, thus, show low catalytic activity. Here, we discuss a series of recent studies that illustrate the advantages of metal–oxide and metal–carbide interfaces when aiming at the conversion of CO2 into methanol. CeO x/Cu(111), Cu/CeO x/TiOmore » 2(110), and Au/CeO x/TiO 2(110) exhibit an activity for the CO 2 → CH 3OH conversion that is 2–3 orders of magnitude higher than that of a benchmark Cu(111) catalyst. In the Cu–ceria and Au–ceria interfaces, the multifunctional combination of metal and oxide centers leads to complementary chemical properties that open active reaction pathways for methanol synthesis. Efficient catalysts are also generated after depositing Cu and Au on TiC(001). In these cases, strong metal–support interactions modify the electronic properties of the admetals and make them active for the binding of CO 2 and its subsequent transformation into CH 3OH at the metal–carbide interfaces.« less

Carbon emissions due to deforestation for the production of charcoal used in Brazil’s steel industry

NASA Astrophysics Data System (ADS)

Sonter, Laura J.; Barrett, Damian J.; Moran, Chris J.; Soares-Filho, Britaldo S.

2015-04-01

Steel produced using coal generates 7% of global anthropogenic CO2 emissions annually. Opportunities exist to substitute this coal with carbon-neutral charcoal sourced from plantation forests to mitigate project-scale emissions and obtain certified emission reduction credits under the Kyoto Protocol’s Clean Development Mechanism. This mitigation strategy has been implemented in Brazil and is one mechanism among many used globally to reduce anthropogenic CO2 emissions; however, its potential adverse impacts have been overlooked to date. Here, we report that total CO2 emitted from Brazilian steel production doubled (91 to 182 MtCO2) and specific emissions increased (3.3 to 5.2 MtCO2 per Mt steel) between 2000 and 2007, even though the proportion of coal used declined. Infrastructure upgrades and a national plantation shortage increased industry reliance on charcoal sourced from native forests, which emits up to nine times more CO2 per tonne of steel than coal. Preventing use of native forest charcoal could have avoided 79% of the CO2 emitted from steel production between 2000 and 2007; however, doing so by increasing plantation charcoal supply is limited by socio-economic costs and risks further indirect deforestation pressures and emissions. Effective climate change mitigation in Brazil’s steel industry must therefore minimize all direct and indirect carbon emissions generated from steel manufacture.

Compact, Lightweight Adsorber and Sabatier Reactor for CO2 Capture and Reduction for Consumable and Propellant Production

NASA Technical Reports Server (NTRS)

Junaedi, Christian; Hawley, Kyle; Walsh, Dennis; Roychoudhury, Subir; Busby, Stacy A.; Abney, Morgan B.; Perry, Jay L.; Knox, James C.

2012-01-01

The utilization of CO2 to produce (or recycle) life support consumables, such as O2 and H2O, and to generate propellant fuels is an important aspect of NASA's concept for future, long duration planetary exploration. One potential approach is to capture and use CO2 from the Martian atmosphere to generate the consumables and propellant fuels. Precision Combustion, Inc. (PCI), with support from NASA, continues to develop its regenerable adsorber technology for capturing CO2 from gaseous atmospheres (for cabin atmosphere revitalization and in-situ resource utilization applications) and its Sabatier reactor for converting CO2 to methane and water. Both technologies are based on PCI's Microlith(R) substrates and have been demonstrated to reduce size, weight, and power consumption during CO2 capture and methanation process. For adsorber applications, the Microlith substrates offer a unique resistive heating capability that shows potential for short regeneration time and reduced power requirements compared to conventional systems. For the Sabatier applications, the combination of the Microlith substrates and durable catalyst coating permits efficient CO2 methanation that favors high reactant conversion, high selectivity, and durability. Results from performance testing at various operating conditions will be presented. An effort to optimize the Sabatier reactor and to develop a bench-top Sabatier Development Unit (SDU) will be discussed.

Monitoring seasonal state and mapping species in Alaskan taiga using imaging radar as input to CO[sub 2] flux models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Way, J.B.; Rignot, E.; McDonald, K.

1993-06-01

Changes in the seasonal CO[sub 2] flux of the boreal forests may result from increased atmospheric CO[sub 2] concentrations and associated atmospheric warming. To monitor this potential change, a combination of remote sensing information and ecophysiological models are required. In this paper we address the use of synthetic aperture radar (SAR) data to provide some of the input to the ecophysiological models: forest type, freeze/thaw state which limits the growing season for conifers, and leaf on/off state which limits the growing season for deciduous species. AIRSAR data collected in March 1988 during an early thaw event and May 1991 duringmore » spring breakup are used to generate species maps and to determine the sensitivity of SAR to canopy freeze/thaw transitions. These data are also used to validate a microwave scattering model which is then used to determine the sensitivity of SAR to leaf on/off and soil freeze/thaw transitions. Finally, a CO[sub 2] flux algorithm which utilizes SAR data and an ecophysiological model to estimate CO[sub 2] flux is presented. CO[sub 2] flux maps are generated from which areal estimates of CO[sub 2] flux are derived. This work was carried out at the Jet Propulsion Laboratory under contract to the NASA.« less

Reduction of CO2 emission by INCAM model in Malaysia biomass power plants during the year 2016.

PubMed

Amin, Nor Aishah Saidina; Talebian-Kiakalaieh, Amin

2018-03-01

As the world's second largest palm oil producer and exporter, Malaysia could capitalize on its oil palm biomass waste for power generation. The emission factors from this renewable energy source are far lower than that of fossil fuels. This study applies an integrated carbon accounting and mitigation (INCAM) model to calculate the amount of CO 2 emissions from two biomass thermal power plants. The CO 2 emissions released from biomass plants utilizing empty fruit bunch (EFB) and palm oil mill effluent (POME), as alternative fuels for powering steam and gas turbines, were determined using the INCAM model. Each section emitting CO 2 in the power plant, known as the carbon accounting center (CAC), was measured for its carbon profile (CP) and carbon index (CI). The carbon performance indicator (CPI) included electricity, fuel and water consumption, solid waste and waste-water generation. The carbon emission index (CEI) and carbon emission profile (CEP), based on the total monthly carbon production, were determined across the CPI. Various innovative strategies resulted in a 20%-90% reduction of CO 2 emissions. The implementation of reduction strategies significantly reduced the CO 2 emission levels. Based on the model, utilization of EFB and POME in the facilities could significantly reduce the CO 2 emissions and increase the potential for waste to energy initiatives. Copyright © 2017 Elsevier Ltd. All rights reserved.

Synthesis of asymmetric polyetherimide membrane for CO2/N2 separation

NASA Astrophysics Data System (ADS)

Ahmad, A. L.; Salaudeen, Y. O.; Jawad, Z. A.

2017-06-01

Large emission of carbon dioxide (CO2) to the environment requires mitigation to avoid unbearable consequences on global climate change. The CO2 emissions generated by fossil fuel combustion within the power and industrial sectors need to be quickly curbed. The gas emission can be abated using membrane technology; this is one of the most promising approaches for selective separation of CO2/N2. The purpose of the study is to synthesis an asymmetric polyetherimide (PEI) membrane and to establish its morphological characteristics for CO2/N2 separation. The PEI flat-sheet asymmetric membrane was fabricated using phase inversion with N-methyl-2-pyrrolidone (NMP) as solvent and water-isopropanol as a coagulant. Particularly, polymer concentration of 20, 25, and 30 wt. % were studied. In addition, the structure and morphology of the produced membrane were observed using scanning electron microscopy (SEM). Importantly, results showed that the membrane with high PEI concentration of 30 wt. % yield an optimal selectivity of 10.7 for CO2/Nitrogen (N2) separation at 1 bar and 25 ºC for pure gas, aided by the membrane surface morphology. The dense skin present was as a result of non-solvent (water) while isopropanol generates a porous sponge structure. This appreciable separation performance makes the PEI asymmetric membrane an attractive alternative for CO2/N2 separation.

Quaternized polymeric microgels as metal free catalyst for H2 production from the methanolysis of sodium borohydride

NASA Astrophysics Data System (ADS)

Sahiner, Nurettin; Sengel, Sultan Butun

2016-12-01

Polymeric microgels derived from tris(2-amino ethyl)amine (TAEA) and glycerol diglycidyl ether as p(TAEA-co-GDE) via microemulsion polymerization techniques are protonated by 0.5 M HCl treatment as p(TAEA-co-GDE)-HCl). These microgels are then exposed to anion exchange reactions with differ ionic liquid forming salts, such as potassium thiocyanate (PTC), sodium dicyanamide (SDCA), ammonium hexafluorophosphate (AHFP), and sodium tetrafluoroborate (STFB) in aqueous medium for the preparation of p(TAEA-co-GDE) based ionic liquid colloidal microgels. These anions exchanged p(TAEA-co-GDE) ionic liquid colloids (ILCs) are directly used as catalyst for hydrogen (H2) generation from the methanol solution of sodium borohydride (NaBH4). Various parameters affecting the H2 production rate such as the catalyst types, NaBH4 amount, and the temperature are investigated. It is found that the methanolysis of NaBH4 catalyzed by p(TAEA-co-GDE)-HCl obeys the first order reaction kinetic. The activation energy, enthalpy and entropy of the protonated p(TAEA-co-GDE) microgels are calculated and found as the 30.37 kJ mol-1, 27.96 kJ mol-1, and -148.08 J mol-1 K-1, respectively. Furthermore, the hydrogen generation rate of 3018 mL min-1 g-1 catalyzed by p(TAEA-co-GDE)-HCl catalyst is attained.

Conductive Polymer Binder-Enabled SiO–Sn xCo yC z Anode for High-Energy Lithium-Ion Batteries

DOE PAGES

Zhao, Hui; Fu, Yanbao; Ling, Min; ...

2016-05-10

In this paper, a SiOSnCoC composite anode is assembled using a conductive polymer binder for the application in next-generation high energy density lithium-ion batteries. A specific capacity of 700 mAh/g is achieved at a 1C (900 mA/g) rate. A high active material loading anode with an areal capacity of 3.5 mAh/cm 2 is demonstrated by mixing SiOSnCoC with graphite. To compensate for the lithium loss in the first cycle, stabilized lithium metal powder (SLMP) is used for prelithiation; when paired with a commercial cathode, a stable full cell cycling performance with a 86% first cycle efficiency is realized. Finally, bymore » achieving these important metrics toward a practical application, this conductive polymer binder/SiOSnCoC anode system presents great promise to enable the next generation of high-energy lithium-ion batteries.« less

Cu/Mn bimetallic catalysis enables carbonylative Suzuki–Miyaura coupling with unactivated alkyl electrophiles† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c7sc01170a Click here for additional data file.

PubMed Central

Pye, Dominic R.; Cheng, Li-Jie

2017-01-01

A bimetallic system consisting of Cu-carbene and Mn-carbonyl co-catalysts was employed for carbonylative C–C coupling of arylboronic esters with alkyl halides, allowing for the convergent synthesis of ketones. The system operates under mild conditions and exhibits complementary reactivity to Pd catalysis. The method is compatible with a wide range of arylboronic ester nucleophiles and proceeds smoothly for both primary and secondary alkyl iodide electrophiles. Preliminary mechanistic experiments corroborate a hypothetical catalytic mechanism consisting of co-dependent cycles wherein the Cu-carbene co-catalyst engages in transmetallation to generate an organocopper nucleophile, while the Mn-carbonyl co-catalyst activates the alkyl halide electrophile by single-electron transfer and then undergoes reversible carbonylation to generate an acylmanganese electrophile. The two cycles then intersect with a heterobimetallic, product-releasing C–C coupling step. PMID:28966784

Atomic disorder, phase transformation, and phase restoration in Co3Sn2

NASA Astrophysics Data System (ADS)

di, L. M.; Zhou, G. F.; Bakker, H.

1993-03-01

The behavior of the intermetallic compound Co3Sn2 upon ball milling was studied by x-ray diffraction, high-field-magnetization measurements, and subsequently by differential scanning calorimetry. It turns out that starting from the stoichiometric-ordered compound, mechanical attrition of Co3Sn2 generates atomic disorder in the early stage of milling. The nonequilibrium phase transformation from the low-temperature phase with orthorhombic structure to the high-temperature phase with a hexagonal structure was observed in the intermediate stage of milling. It was accompanied by the creation of increasing atomic disorder. After long milling periods, the phase transformation was completed and the atomic disordering became saturated. All the physical parameters measured in the present work remained constant during this period. The above outcome was confirmed by comparison with the high-temperature phase thermally induced by quenching. The good agreement of the results obtained by different techniques proves that the ball milling generates well-defined metastable states in Co3Sn2.

pH-Responsive mineralized nanoparticles as stable nanocarriers for intracellular nitric oxide delivery.

PubMed

Lee, Hong Jae; Kim, Da Eun; Park, Dong Jin; Choi, Gi Hyun; Yang, Dal-Nim; Heo, Jung Sun; Lee, Sang Cheon

2016-10-01

We describe a calcium carbonate (CaCO3) mineralization approach to generate pH-responsive nanocarriers that can stably load S-nitrosoglutathione (GSNO) and dissolve at acidic endosomes to trigger intracellular release of nitric oxide (NO). GSNO-loaded CaCO3-mineralized nanoparticles (GSNO-MNPs) were prepared by an anionic block copolymer (PEG-Poly(l-aspartic acid))-templated mineralization. Ionic GSNO could be loaded in situ inside the CaCO3 core during the mineralization process. The stability of GSNO shielded within the crystalline CaCO3 core was greatly enhanced. The GSNO-MNPs triggered NO release at endosomal pH and an intracellular ascorbic acid level. Confocal microscopy demonstrated that the GSNO-MNPs could be dissolved at endosomal environments to release GSNO and sequentially generate NO through the GSNO reduction in the cytosol. In vitro cell experiments demonstrated that NO release by the GSNO-MNPs efficiently improved therapeutic activity of doxorubicin (DOX). Copyright © 2016 Elsevier B.V. All rights reserved.

Amorphous cobalt potassium phosphate microclusters as efficient photoelectrochemical water oxidation catalyst

NASA Astrophysics Data System (ADS)

Zhang, Ye; Zhao, Chunsong; Dai, Xuezeng; Lin, Hong; Cui, Bai; Li, Jianbao

2013-12-01

A novel amorphous cobalt potassium phosphate hydrate compound (KCoPO4·H2O) is identified to be active photocatalyst for oxygen evolution reaction (OER) to facilitate hydrogen generation from water photolysis. It has been synthesized through a facile and cost-effective solution-based precipitation method using earth-abundant materials. Its highly porous structure and large surface areas are found to be responsible for the excellent electrochemical performance featuring a low OER onset at ∼550 mVSCE and high current density in alkaline condition. Unlike traditional cobalt-based spinel oxides (Co3O4, NiCo2O4) and phosphate (Co-Pi, Co(PO3)2) electrocatalysts, with proper energy band alignment for light-assisted water oxidation, cobalt potassium phosphate hydrate also exhibits robust visible-light response, generating a photocurrent density of ∼200 μA cm-2 at 0.7 VSCE. This catalyst could thus be considered as a promising candidate to perform photoelectrochemical water splitting.

Light-driven carbon dioxide reduction to methane by nitrogenase in a photosynthetic bacterium

PubMed Central

Fixen, Kathryn R.; Zheng, Yanning; Harris, Derek F.; Shaw, Sudipta; Yang, Zhi-Yong; Dean, Dennis R.; Seefeldt, Lance C.

2016-01-01

Nitrogenase is an ATP-requiring enzyme capable of carrying out multielectron reductions of inert molecules. A purified remodeled nitrogenase containing two amino acid substitutions near the site of its FeMo cofactor was recently described as having the capacity to reduce carbon dioxide (CO2) to methane (CH4). Here, we developed the anoxygenic phototroph, Rhodopseudomonas palustris, as a biocatalyst capable of light-driven CO2 reduction to CH4 in vivo using this remodeled nitrogenase. Conversion of CO2 to CH4 by R. palustris required constitutive expression of nitrogenase, which was achieved by using a variant of the transcription factor NifA that is able to activate expression of nitrogenase under all growth conditions. Also, light was required for generation of ATP by cyclic photophosphorylation. CH4 production by R. palustris could be controlled by manipulating the distribution of electrons and energy available to nitrogenase. This work shows the feasibility of using microbes to generate hydrocarbons from CO2 in one enzymatic step using light energy. PMID:27551090

Exfoliation and reassembly of cobalt oxide nanosheets into a reversible lithium-ion battery cathode.

PubMed

Compton, Owen C; Abouimrane, Ali; An, Zhi; Palmeri, Marc J; Brinson, L Catherine; Amine, Khalil; Nguyen, SonBinh T

2012-04-10

An exfoliation-reassembly-activation (ERA) approach to lithium-ion battery cathode fabrication is introduced, demonstrating that inactive HCoO(2) powder can be converted into a reversible Li(1-x) H(x) CoO(2) thin-film cathode. This strategy circumvents the inherent difficulties often associated with the powder processing of the layered solids typically employed as cathode materials. The delamination of HCoO(2) via a combination of chemical and mechanical exfoliation generates a highly processable aqueous dispersion of [CoO(2) ](-) nanosheets that is critical to the ERA approach. Following vacuum-assisted self-assembly to yield a thin-film cathode and ion exchange to activate this material, the generated cathodes exhibit excellent cyclability and discharge capacities approaching that of low-temperature-prepared LiCoO(2) (~83 mAh g(-1) ), with this good electrochemical performance attributable to the high degree of order in the reassembled cathode. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fixen, Kathryn R.; Zheng, Yanning; Harris, Derek F.

Nitrogenase is an ATP-requiring enzyme capable of carrying out multielectron reductions of inert molecules. A purified remodeled nitrogenase containing two amino acid substitutions near the site of its FeMo cofactor was recently described as having the capacity to reduce carbon dioxide (CO 2) to methane (CH 4). Here, we developed the anoxygenic phototroph, Rhodopseudomonas palustris, as a biocatalyst capable of light-driven CO 2 reduction to CH 4 in vivo using this remodeled nitrogenase. Conversion of CO 2 to CH 4 by R. palustris required constitutive expression of nitrogenase, which was achieved by using a variant of the transcription factor NifAmore » that is able to activate expression of nitrogenase under all growth conditions. Also, light was required for generation of ATP by cyclic photophosphorylation. CH 4 production by R. palustris could be controlled by manipulating the distribution of electrons and energy available to nitrogenase. Furthermore, this work shows the feasibility of using microbes to generate hydrocarbons from CO 2 in one enzymatic step using light energy.« less

Hexavalent chromium content in stainless steel welding fumes is dependent on the welding process and shield gas type.

PubMed

Keane, Michael; Stone, Samuel; Chen, Bean; Slaven, James; Schwegler-Berry, Diane; Antonini, James

2009-02-01

Occupational exposure to welding fumes is a known health hazard. To isolate elements in stainless steel welding fumes with high potential for adverse health outcomes, fumes were generated using a robotic gas metal arc system, using four shield gases of varying oxygen content. The objective was to measure Cr(VI) concentrations in a broad spectrum of gas metal arc welding processes, and identify processes of exceptionally high or low Cr(VI) content. The gases used were 95% Ar/5% O(2), 98% Ar/2% O(2), 95% Ar/5%CO(2), and 75% He/25% Ar. The welder was operated in axial spray mode (Ar/O(2), Ar/CO(2)), short-circuit (SC) mode (Ar/CO(2) low voltage and He/Ar), and pulsed axial-spray mode (98% Ar/2% O(2)). Results indicate large differences in Cr(VI) in the fumes, with Ar/O(2) (Pulsed)>Ar/O(2)>Ar/CO(2)>Ar/CO(2) (SC)>He/Ar; values were 3000+/-300, 2800+/-85, 2600+/-120, 1400+/-190, and 320+/-290 ppm respectively (means +/- standard errors for 2 runs and 3 replicates per run). Respective rates of Cr(VI) generation were 1.5, 3.2, 4.4, 1.3, and 0.46 microg/min; generation rates were also calculated in terms of microg Cr(VI) per metre of wire used. The generation rates of Cr(VI) increased with increasing O(3) concentrations. Particle size measurements indicated similar distributions, but somewhat higher >0.6 microm fractions for the short-circuit mode samples. Fumes were also sampled into 2 selected size ranges, a microspatter fraction (>or=0.6 microm) and a fine (<0.6 microm) fraction; analysis indicated that Cr(VI) is primarily associated with particles <0.6 microm. The conclusion of the study is that Cr(VI) concentrations vary significantly with welding type and shield gas type, and this presents an opportunity to tailor welding practices to lessen Cr(VI) exposures in workplaces by selecting low Cr(VI)-generating processes. Short-circuit processes generated less Cr(VI) than axial-spray methods, and inert gas shielding gave lower Cr(VI) content than shielding with active gases. A short circuit He/Ar shielded process and a pulsed axial spray Ar/O(2) process were both identified as having substantially lower Cr(VI) generation rates per unit of wire used relative to the other processes studied.

Enhanced orbital magnetic moment in FeCo nanogranules observed by Barnett effect

NASA Astrophysics Data System (ADS)

Ogata, Y.; Chudo, H.; Gu, B.; Kobayashi, N.; Ono, M.; Harii, K.; Matsuo, M.; Saitoh, E.; Maekawa, S.

2017-11-01

The gyroscopic g factor, g‧ , of FeCo nanogranules embedded in a matrix of MgF2 (FeCo-MgF2) was determined by measuring the magnetic-field generation from a rotating sample due to the Barnett effect. The g‧ value of the FeCo-MgF2 is estimated to be 1.76 ± 0.11. The orbital contribution to the magnetic moment in the FeCo nanogranules was found to be quite large compared with that in bulk FeCo, being consistent with a density-functional-theory calculation that shows that the orbital magnetic moment may increase at the FeCo/MgF2 interfaces. The result suggests that the orbital magnetic moment is enhanced by symmetry breaking at the surface of the FeCo nanogranules.

Carbon dioxide utilization via carbonate-promoted C-H carboxylation.

PubMed

Banerjee, Aanindeeta; Dick, Graham R; Yoshino, Tatsuhiko; Kanan, Matthew W

2016-03-10

Using carbon dioxide (CO2) as a feedstock for commodity synthesis is an attractive means of reducing greenhouse gas emissions and a possible stepping-stone towards renewable synthetic fuels. A major impediment to synthesizing compounds from CO2 is the difficulty of forming carbon-carbon (C-C) bonds efficiently: although CO2 reacts readily with carbon-centred nucleophiles, generating these intermediates requires high-energy reagents (such as highly reducing metals or strong organic bases), carbon-heteroatom bonds or relatively acidic carbon-hydrogen (C-H) bonds. These requirements negate the environmental benefit of using CO2 as a substrate and limit the chemistry to low-volume targets. Here we show that intermediate-temperature (200 to 350 degrees Celsius) molten salts containing caesium or potassium cations enable carbonate ions (CO3(2-)) to deprotonate very weakly acidic C-H bonds (pKa > 40), generating carbon-centred nucleophiles that react with CO2 to form carboxylates. To illustrate a potential application, we use C-H carboxylation followed by protonation to convert 2-furoic acid into furan-2,5-dicarboxylic acid (FDCA)--a highly desirable bio-based feedstock with numerous applications, including the synthesis of polyethylene furandicarboxylate (PEF), which is a potential large-scale substitute for petroleum-derived polyethylene terephthalate (PET). Since 2-furoic acid can readily be made from lignocellulose, CO3(2-)-promoted C-H carboxylation thus reveals a way to transform inedible biomass and CO2 into a valuable feedstock chemical. Our results provide a new strategy for using CO2 in the synthesis of multi-carbon compounds.

Carbon dioxide utilization via carbonate-promoted C-H carboxylation

NASA Astrophysics Data System (ADS)

Banerjee, Aanindeeta; Dick, Graham R.; Yoshino, Tatsuhiko; Kanan, Matthew W.

2016-03-01

Using carbon dioxide (CO2) as a feedstock for commodity synthesis is an attractive means of reducing greenhouse gas emissions and a possible stepping-stone towards renewable synthetic fuels. A major impediment to synthesizing compounds from CO2 is the difficulty of forming carbon-carbon (C-C) bonds efficiently: although CO2 reacts readily with carbon-centred nucleophiles, generating these intermediates requires high-energy reagents (such as highly reducing metals or strong organic bases), carbon-heteroatom bonds or relatively acidic carbon-hydrogen (C-H) bonds. These requirements negate the environmental benefit of using CO2 as a substrate and limit the chemistry to low-volume targets. Here we show that intermediate-temperature (200 to 350 degrees Celsius) molten salts containing caesium or potassium cations enable carbonate ions (CO32-) to deprotonate very weakly acidic C-H bonds (pKa > 40), generating carbon-centred nucleophiles that react with CO2 to form carboxylates. To illustrate a potential application, we use C-H carboxylation followed by protonation to convert 2-furoic acid into furan-2,5-dicarboxylic acid (FDCA)—a highly desirable bio-based feedstock with numerous applications, including the synthesis of polyethylene furandicarboxylate (PEF), which is a potential large-scale substitute for petroleum-derived polyethylene terephthalate (PET). Since 2-furoic acid can readily be made from lignocellulose, CO32--promoted C-H carboxylation thus reveals a way to transform inedible biomass and CO2 into a valuable feedstock chemical. Our results provide a new strategy for using CO2 in the synthesis of multi-carbon compounds.

Control of cavitation using dissolved carbon dioxide for damage-free megasonic cleaning of wafers

NASA Astrophysics Data System (ADS)

Kumari, Sangita

This dissertation describes the finding that dissolved carbon dioxide is a potent inhibitor of sonoluminescence and describes the implications of the finding in the development of improved megasonic cleaning formulations. Megasonic cleaning, or the removal of contaminants particles from wafer surfaces using sound-irradiated cleaning fluids, has been traditionally used in the semiconductor industry for cleaning of wafers. A critical challenge in the field is to achieve removal of small particles (22 nm to 200 nm) without causing damage to fine wafer features. The work described here addresses this challenge by identifying sonoluminescence and solution pH as two key factors affecting damage and cleaning efficiency, respectively and establishing novel means to control them using CO2(aq) release compounds in the presence of acids and bases. Sonoluminescence (SL) behavior of the major dissolved gases such as Ar, Air, N2, O2 and CO2 was determined using a newly designed Cavitation Threshold Cell (CT Cell). SL, which is the phenomenon of release of light in sound-irradiated liquids, is a sensitive indicator of cavitation, primarily transient cavitation. It was found that all the tested dissolved gases such as Ar, Air, N2 and O2, generated SL signal efficiently. However, dissolved CO2 was found to be completely incapable of generating SL signal. Based on this interesting result, gradual suppression of SL signal was demonstrated using CO2(aq). It was further demonstrated that CO2(aq) is not only incapable but is also a potent inhibitor of SL. The inhibitory role of CO2(aq) was established using a novel method of controlled in-situ release of CO 2 from NH4HCO3. ~130 ppm CO2(aq) was shown to be necessary and sufficient for complete suppression of SL generation in air saturated DI water. The method however required acidification of solution for significant release of CO2, making it unsuitable for the design of cleaning solutions at high pH. Analysis of the underlying ionic equilibria revealed that the loss of released CO2(aq) upon increase in pH can be compensated by moderate increase in added NH4HCO3. Using this method, simultaneous control of SL and solution pH was demonstrated in two systems, NH4HCO3/HCl and NH4OH/CO2, at two nominal pH values; 5.7 and 7.0. Damage studies were performed on wafer samples with line/space patterns donated by IMEC and FSI International bearing Si/metal/a-Si gate stacks of thickness ~36 nm and Si/Poly-Si gate stacks of thickness ~67 nm, respectively. A single wafer spin cleaning tool MegPieRTM was used for the generation of megasonic energy for inducing damage to the structures. It was demonstrated that CO2 dissolution in DI water suppresses damage to the gate stacks in a dose-dependent manner. Together, these studies establish a systematic and strong correlation between CO2(aq) concentration, SL suppression and damage suppression. Significant damage reduction (~50 % to ~90 %) was observed at [CO2(aq)] > ~300 ppm. It was also demonstrated that CO2(aq) suppresses damage under alkaline pH condition too. This demonstration was made possible by the successful design of two new cleaning systems NH4HCO3/NH4OH and CO2/NH 4OH that could generate CO2(aq) under alkaline conditions. Damage suppressing ability of the newly designed cleaning systems were compared to the standard cleaning system NH4OH at pH 8.2 and it was found that NH4HCO3/NH4OH and CO2/NH 4OH systems were 80 % more efficient in suppressing damage compared to the standard NH4OH cleaning system. Finally, megasonic cleaning studies were conducted in the same single wafer spin cleaning tool MegPieRTM, using SiO2 particles (size 185 nm) deposited on 200 mm oxide Si wafers, as the contaminant. It was found that the standard cleaning chemical, NH4OH, pH 8.2, was effective in achieving > 95 % particle removal for 2 min irradiation of megasonic energy at power densities > 0.7 W/cm2. Based on these results, a new system, NH4HCO3/NH4OH, was designed with an aim to release ~300 ppm CO2 at pH 8.2. It was demonstrated that newly designed system NH4HCO3/NH 4OH, allowed significant suppression of damage in comparison to NH 4OH while maintaining > 90 % cleaning efficiency that was comparable to NH4OH solution, at the same acoustic power densities. Taken together, these studies establish a potent and flexible means for the inhibition of SL generation over a wide pH range and acoustic power densities and demonstrate its use in suppression of wafer damage without compromising megasonic cleaning efficiency. (Abstract shortened by UMI.)

Instantaneous Conversion of [11 C]CO2 to [11 C]CO via Fluoride-Activated Disilane Species.

PubMed

Taddei, Carlotta; Bongarzone, Salvatore; Gee, Antony D

2017-06-07

The development of a fast and novel methodology to generate carbon-11 carbon monoxide ([ 11 C]CO) from cyclotron-produced carbon-11 carbon dioxide ([ 11 C]CO 2 ) mediated by a fluoride-activated disilane species is described. This methodology allows up to 74 % conversion of [ 11 C]CO 2 to [ 11 C]CO using commercially available reagents, readily available laboratory equipment and mild reaction conditions (room temperature). As proof of utility, radiochemically pure [carbonyl- 11 C]N-benzylbenzamide was successfully synthesized from produced [ 11 C]CO in up to 74 % radiochemical yield (RCY) and >99 % radiochemical purity (RCP) in ≤10 min from end of [ 11 C]CO 2 delivery. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

[Study on X-ray powder diffraction of various structured zinc titanate prepared by the method of direct precipitation].

PubMed

Guo, Jian; Wang, Zhi-hua; Tao, Dong-liang; Guo, Guang-sheng

2007-05-01

Zinc titanate powders were prepared from Ti(SO4)2, Zn(NO3)2 x (6)H2O and (NH4)2CO3 by the method of direct precipitation. The effects of reaction conditions on the structure of zinc titanate were studied. The sample was analyzed by means of XRD and TG-DTA. The structure of zinc titanate was affected by the reaction subsequence of the formation of titanic acid and zinc carbonate. In the reaction system where titanic acid was generated earlier, collision reaction occurred between the generated zinc carbonate molecule and the surrounding titanic acid molecule. When titanic acid was generated earlier and precipitant (NH4)2CO3 was sufficient, Zn2Ti3O8 was obtained because of the sufficient collision reaction and superfluous titanic acid. In the reaction system where zinc carbonate was generated earlier, collision reaction occurred between the generated titanic acid molecule and the surrounding zinc carbonate molecule. When zinc carbonate was generated earlier and precipitant (NH4)2CO3 was sufficient, Zn2TiO4 was obtained because of the sufficient collision reaction and superfluous zinc carbonate. In addition, the kinds and structure of the production were affected by the dosage of precipitant and the reaction temperature. Zn2Ti3O8 or Zn2TiO4 could be obtained easier when using more precipitant or higher reaction temperature which could cause more sufficient collision reaction. ZnTiO3 could be obtained under the conditions of less precipitant and lower reaction temperature.

Characterizing thermogenic coalbed gas from Polish coals of different ranks by hydrous pyrolysis

USGS Publications Warehouse

Kotarba, M.J.; Lewan, M.D.

2004-01-01

To provide a better characterization of origin and volume of thermogenic gas generation from coals, hydrous pyrolysis experiments were conducted at 360??C for 72 h on Polish coals ranging in rank from lignite (0.3% R r) to semi-anthracite (2.0% Rr). Under these conditions, the lignites attained a medium-volatile bituminous rank (1.5% Rr), high-volatile bituminous coals attained a low-volatile bituminous rank (1.7% Rr), and the semi-anthracite obtained an anthracite rank (4.0% R r). Hydrous pyrolysis of a coal, irrespective of rank, provides a diagnostic ??13C value for its thermogenic hydrocarbon gases. This value can be used quantitatively to interpret mixing of indigenous thermogenic gas with microbial methane or exogenous thermogenic gas from other sources. Thermogenic methane quantities range from 20 dm3/kg of lignite (0.3% Rr) to 0.35 dm3/kg of semi-anthracite (2.0% Rr). At a vitrinite reflectance of 1.7% Rr, approximately 75% of the maximum potential for a coal to generate thermogenic methane has been expended. At a vitrinite reflectance of 1.7% Rr, more than 90% of the maximum potential for a coal to generate CO2 has been expended. Assuming that these quantities of generated CO2 remain associated with a sourcing coal bed as uplift or erosion provide conditions conducive for microbial methanogenesis, the resulting quantities of microbial methane generated by complete CO2 reduction can exceed the quantities of thermogenic methane generated from the same coal bed by a factor of 2-5. ?? 2004 Elsevier Ltd. All rights reserved.

Imaging Catalytic Activation of CO 2 on Cu 2O (110): A First-Principles Study

DOE PAGES

Li, Liang; Zhang, Rui; Vinson, John; ...

2018-03-05

Balancing global energy needs against increasing greenhouse gas emissions requires new methods for efficient CO 2 reduction. While photoreduction of CO 2 is a viable approach for fuel generation, the rational design of photocatalysts hinges on precise characterization of the surface catalytic reactions. Cu 2O is a promising next-generation photocatalyst, but the atomic-scale description of the interaction between CO 2 and the Cu 2O surface is largely unknown, and detailed experimental measurements are lacking. In this study, density-functional-theory (DFT) calculations have been performed to identify the Cu 2O (110) surface stoichiometry that favors CO 2 reduction. To facilitate interpretation ofmore » scanning tunneling microscopy (STM) and X-ray absorption near-edge structures (XANES) measurements, which are useful for characterizing catalytic reactions, we present simulations based on DFT-derived surface morphologies with various adsorbate types. STM and XANES simulations were performed using the Tersoff Hamann approximation and Bethe-Salpeter equation (BSE) approach, respectively. The results provide guidance for observation of CO 2 reduction reaction on, and rational surface engineering of, Cu 2O (110). In conclusion, they also demonstrate the effectiveness of computational image and spectroscopy modeling as a predictive tool for surface catalysis characterization.« less

Solid electrolyte oxygen regeneration system

NASA Technical Reports Server (NTRS)

Shumar, J. W.; See, G. G.; Schubert, F. H.; Powell, J. D.

1976-01-01

A program to design, develop, fabricate and assemble a one-man, self-contained, solid electrolyte oxygen regeneration system (SX-1) incorporating solid electrolyte electrolyzer drums was completed. The SX-1 is a preprototype engineering model designed to produce 0.952 kg (2.1 lb)/day of breathable oxygen (O2) from the electrolysis of metabolic carbon dioxide (CO2) and water vapor. The CO2 supply rate was established based on the metabolic CO2 generation rate for one man of 0.998 kg (2.2 lb)/day. The water supply rate (0.254 kg (0.56 lb)/day) was designed to be sufficient to make up the difference between the 0.952 kg (2.1 lb)/day O2 generation specification and the O2 available through CO2 electrolysis, 0.726 kg (1.6 lb)/day. The SX-1 was successfully designed, fabricated and assembled. Design verification tests (DVT) or the CO Disproportionators, H2 separators, control instrumentation, monitor instrumentation, water feed mechanism were successfully completed. The erratic occurrence of electrolyzer drum leakage prevented the completion of the CO2 electrolyzer module and water electrolyzer module DVT's and also prevented the performance of SX-1 integrated testing. Further development work is required to improve the solid electrolyte cell high temperature seals.

Imaging Catalytic Activation of CO 2 on Cu 2O (110): A First-Principles Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Liang; Zhang, Rui; Vinson, John

Balancing global energy needs against increasing greenhouse gas emissions requires new methods for efficient CO 2 reduction. While photoreduction of CO 2 is a viable approach for fuel generation, the rational design of photocatalysts hinges on precise characterization of the surface catalytic reactions. Cu 2O is a promising next-generation photocatalyst, but the atomic-scale description of the interaction between CO 2 and the Cu 2O surface is largely unknown, and detailed experimental measurements are lacking. In this study, density-functional-theory (DFT) calculations have been performed to identify the Cu 2O (110) surface stoichiometry that favors CO 2 reduction. To facilitate interpretation ofmore » scanning tunneling microscopy (STM) and X-ray absorption near-edge structures (XANES) measurements, which are useful for characterizing catalytic reactions, we present simulations based on DFT-derived surface morphologies with various adsorbate types. STM and XANES simulations were performed using the Tersoff Hamann approximation and Bethe-Salpeter equation (BSE) approach, respectively. The results provide guidance for observation of CO 2 reduction reaction on, and rational surface engineering of, Cu 2O (110). In conclusion, they also demonstrate the effectiveness of computational image and spectroscopy modeling as a predictive tool for surface catalysis characterization.« less

A model to evaluate 100-year energy mix scenarios to facilitate deep decarbonization in the southeastern United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adkisson, Mary A.; Qualls, A. L.

The Southeast United States consumes approximately one billion megawatt-hours of electricity annually; roughly two-thirds from carbon dioxide (CO 2) emitting sources. The balance is produced by non-CO 2 emitting sources: nuclear power, hydroelectric power, and other renewables. Approximately 40% of the total CO 2 emissions come from the electric grid. The CO 2 emitting sources, coal, natural gas, and petroleum, produce approximately 372 million metric tons of CO 2 annually. The rest is divided between the transportation sector (36%), the industrial sector (20%), the residential sector (3%), and the commercial sector (2%). An Energy Mix Modeling Analysis (EMMA) tool wasmore » developed to evaluate 100-year energy mix strategies to reduce CO 2 emissions in the southeast. Current energy sector data was gathered and used to establish a 2016 reference baseline. The spreadsheet-based calculation runs 100-year scenarios based on current nuclear plant expiration dates, assumed electrical demand changes from the grid, assumed renewable power increases and efficiency gains, and assumed rates of reducing coal generation and deployment of new nuclear reactors. Within the model, natural gas electrical generation is calculated to meet any demand not met by other sources. Thus, natural gas is viewed as a transitional energy source that produces less CO 2 than coal until non-CO 2 emitting sources can be brought online. The annual production of CO 2 and spent nuclear fuel and the natural gas consumed are calculated and summed. A progression of eight preliminary scenarios show that nuclear power can substantially reduce or eliminate demand for natural gas within 100 years if it is added at a rate of only 1000 MWe per year. Any increases in renewable energy or efficiency gains can offset the need for nuclear power. However, using nuclear power to reduce CO 2 will result in significantly more spent fuel. More efficient advanced reactors can only marginally reduce the amount of spent fuel generated in the next 100 years if they are assumed to be available beginning around 2040. Thus closing the nuclear fuel cycle to reduce nuclear spent fuel inventories should be considered. Future work includes the incorporation of economic features into the model and the extension of the evaluation to the industrial sector. It will also be necessary to identify suitable sites for additional reactors.« less

Microbial Inactivation by Ultrasound Assisted Supercritical Fluids

NASA Astrophysics Data System (ADS)

Benedito, Jose; Ortuño, Carmen; Castillo-Zamudio, Rosa Isela; Mulet, Antonio

A method combining supercritical carbon dioxide (SC-CO2) and high power ultrasound (HPU) has been developed and tested for microbial/enzyme inactivation purposes, at different process conditions for both liquid and solid matrices. In culture media, using only SC-CO2, the inactivation rate of E. coli and S. cerevisiae increased with pressure and temperature; and the total inactivation (7-8 log-cycles) was attained after 25 and 140 min of SC-CO2 (350 bar, 36 °C) treatment, respectively. Using SC-CO2+HPU, the time for the total inactivation of both microorganisms was reduced to only 1-2 min, at any condition selected. The SC-CO2+HPU inactivation of both microorganisms was slower in juices (avg. 4.9 min) than in culture media (avg. 1.5 min). In solid samples (chicken, turkey ham and dry-cured pork cured ham) treated with SC-CO2 and SC-CO2+HPU, the inactivation rate of E. coli increased with temperature. The application of HPU to the SC-CO2 treatments accelerated the inactivation rate of E. coli and that effect was more pronounced in treatments with isotonic solution surrounding the solid food samples. The application of HPU enhanced the SC-CO2 inactivation mechanisms of microorganisms, generating a vigorous agitation that facilitated the CO2 solubilization and the mass transfer process. The cavitation generated by HPU could damage the cell walls accelerating the extraction of vital constituents and the microbial death. Thus, using the combined technique, reasonable industrial processing times and mild process conditions could be used which could result into a cost reduction and lead to the minimization in the food nutritional and organoleptic changes.

Design of experimental setup for supercritical CO2 jet under high ambient pressure conditions

NASA Astrophysics Data System (ADS)

Shi, Huaizhong; Li, Gensheng; He, Zhenguo; Wang, Haizhu; Zhang, Shikun

2016-12-01

With the commercial extraction of hydrocarbons in shale and tight reservoirs, efficient methods are needed to accelerate developing process. Supercritical CO2 (SC-CO2) jet has been considered as a potential way due to its unique fluid properties. In this article, a new setup is designed for laboratory experiment to research the SC-CO2 jet's characteristics in different jet temperatures, pressures, standoff distances, ambient pressures, etc. The setup is composed of five modules, including SC-CO2 generation system, pure SC-CO2 jet system, abrasive SC-CO2 jet system, CO2 recovery system, and data acquisition system. Now, a series of rock perforating (or case cutting) experiments have been successfully conducted using the setup about pure and abrasive SC-CO2 jet, and the results have proven the great perforating efficiency of SC-CO2 jet and the applications of this setup.

Design of experimental setup for supercritical CO2 jet under high ambient pressure conditions.

PubMed

Shi, Huaizhong; Li, Gensheng; He, Zhenguo; Wang, Haizhu; Zhang, Shikun

2016-12-01

With the commercial extraction of hydrocarbons in shale and tight reservoirs, efficient methods are needed to accelerate developing process. Supercritical CO 2 (SC-CO 2 ) jet has been considered as a potential way due to its unique fluid properties. In this article, a new setup is designed for laboratory experiment to research the SC-CO 2 jet's characteristics in different jet temperatures, pressures, standoff distances, ambient pressures, etc. The setup is composed of five modules, including SC-CO 2 generation system, pure SC-CO 2 jet system, abrasive SC-CO 2 jet system, CO 2 recovery system, and data acquisition system. Now, a series of rock perforating (or case cutting) experiments have been successfully conducted using the setup about pure and abrasive SC-CO 2 jet, and the results have proven the great perforating efficiency of SC-CO 2 jet and the applications of this setup.

Reduction of CO2 Emissions Due to Wind Energy - Methods and Issues in Estimating Operational Emission Reductions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holttinen, Hannele; Kiviluoma, Juha; McCann, John

2015-10-05

This paper presents ways of estimating CO2 reductions of wind power using different methodologies. Estimates based on historical data have more pitfalls in methodology than estimates based on dispatch simulations. Taking into account exchange of electricity with neighboring regions is challenging for all methods. Results for CO2 emission reductions are shown from several countries. Wind power will reduce emissions for about 0.3-0.4 MtCO2/MWh when replacing mainly gas and up to 0.7 MtCO2/MWh when replacing mainly coal powered generation. The paper focuses on CO2 emissions from power system operation phase, but long term impacts are shortly discussed.

Implementation of New System for Oxygen Generation and Carbon Dioxide Removal =

NASA Astrophysics Data System (ADS)

Karavolos, Angelo Peter

This research effort develops an integrated system for CO2 removal and O2 production. A unique material, dodeca-tungsto-phosphoric acid (H3PO4W12O3; henceforth referred to as DTPA) is mixed with tetra-ethyl-ortho-silicate Si(OC2H 5)4 or TEOS. This mixture exhibits unique properties of heat absorption and high electrical conductivity. In the system described herein, the DTPA resides within a cross linked arrangement of TEOS. The DTPA furnishes a source of O2, while the TEOS furnishes structural support for the large DTPA crystals. In addition, the large amount of H2O within the crystal also adsorbs CO2. It can also be cross-linked with other polymers such as polycarbonate, for different applications and properties such as flexible textiles. A set of isolated bench experiments were designed to test CO2 adsorption, O2 production, heat production, and voltage production were conducted to test the hypothesis that DTPA can provide CO2 adsorption, O2 generation, heat generation and electrical generation. Five experiments with this apparatus were conducted: (1) a mass balance experiment; (2) an X-ray diffraction experiment; (3) a photo spectroscopic experiment; (4) a calorimetric experiment; and (5) a dielectric experiment. Results illustrate that approximately 2880 grams of this material produces 576 grams of O2, and removes 1760 grams of CO2. The reaction also produces approximately 844 kJ/mole heat, and can supply 12.2 V potential over a period of 4.5 hours. The amount of unused material and the recycling ability suggests the usefulness of the technique to achieve between a 50-75% closed system. In addition, an experiment using 18O tracer demonstrated that approximately 20% of the O2 produced comes from processed CO2 adsorbed by the crystal, while the remaining 80% of the O2 produced comes from replaced O2 within the crystal itself. The device has multiple applications including environmental control and life support for aircraft cabins, space vehicle interiors, submarine pressure vessels, sealed armored vehicles, and personal protective equipment for individuals working in confined spaces such as mines. None

PdO doping tunes band-gap energy levels as well as oxidative stress responses to a Co₃O₄ p-type semiconductor in cells and the lung.

PubMed

Zhang, Haiyuan; Pokhrel, Suman; Ji, Zhaoxia; Meng, Huan; Wang, Xiang; Lin, Sijie; Chang, Chong Hyun; Li, Linjiang; Li, Ruibin; Sun, Bingbing; Wang, Meiying; Liao, Yu-Pei; Liu, Rong; Xia, Tian; Mädler, Lutz; Nel, André E

2014-04-30

We demonstrate through PdO doping that creation of heterojunctions on Co3O4 nanoparticles can quantitatively adjust band-gap and Fermi energy levels to study the impact of metal oxide nanoparticle semiconductor properties on cellular redox homeostasis and hazard potential. Flame spray pyrolysis (FSP) was used to synthesize a nanoparticle library in which the gradual increase in the PdO content (0-8.9%) allowed electron transfer from Co3O4 to PdO to align Fermi energy levels across the heterojunctions. This alignment was accompanied by free hole accumulation at the Co3O4 interface and production of hydroxyl radicals. Interestingly, there was no concomitant superoxide generation, which could reflect the hole dominance of a p-type semiconductor. Although the electron flux across the heterojunctions induced upward band bending, the E(c) levels of the doped particles showed energy overlap with the biological redox potential (BRP). This allows electron capture from the redox couples that maintain the BRP from -4.12 to -4.84 eV, causing disruption of cellular redox homeostasis and induction of oxidative stress. PdO/Co3O4 nanoparticles showed significant increases in cytotoxicity at 25, 50, 100, and 200 μg/mL, which was enhanced incrementally by PdO doping in BEAS-2B and RAW 264.7 cells. Oxidative stress presented as a tiered cellular response involving superoxide generation, glutathione depletion, cytokine production, and cytotoxicity in epithelial and macrophage cell lines. A progressive series of acute pro-inflammatory effects could also be seen in the lungs of animals exposed to incremental PdO-doped particles. All considered, generation of a combinatorial PdO/Co3O4 nanoparticle library with incremental heterojunction density allowed us to demonstrate the integrated role of E(v), E(c), and E(f) levels in the generation of oxidant injury and inflammation by the p-type semiconductor, Co3O4.

Analysis of greenhouse gas emissions from 10 biogas plants within the agricultural sector.

PubMed

Liebetrau, J; Reinelt, T; Clemens, J; Hafermann, C; Friehe, J; Weiland, P

2013-01-01

With the increasing number of biogas plants in Germany the necessity for an exact determination of the actual effect on the greenhouse gas emissions related to the energy production gains importance. Hitherto the life cycle assessments have been based on estimations of emissions of biogas plants. The lack of actual emission evaluations has been addressed within a project from which the selected results are presented here. The data presented here have been obtained during a survey in which 10 biogas plants were analysed within two measurement periods each. As the major methane emission sources the open storage of digestates ranging from 0.22 to 11.2% of the methane utilized and the exhaust of the co-generation units ranging from 0.40 to 3.28% have been identified. Relevant ammonia emissions have been detected from the open digestate storage. The main source of nitrous oxide emissions was the co-generation unit. Regarding the potential of measures to reduce emissions it is highly recommended to focus on the digestate storage and the exhaust of the co-generation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Follis, Kathryn E.; York, Joanne; Nunberg, Jack H.

The fusogenic potential of Class I viral envelope glycoproteins is activated by proteloytic cleavage of the precursor glycoprotein to generate the mature receptor-binding and transmembrane fusion subunits. Although the coronavirus (CoV) S glycoproteins share membership in this class of envelope glycoproteins, cleavage to generate the respective S1 and S2 subunits appears absent in a subset of CoV species, including that responsible for the severe acute respiratory syndrome (SARS). To determine whether proteolytic cleavage of the S glycoprotein might be important for the newly emerged SARS-CoV, we introduced a furin recognition site at single basic residues within the putative S1-S2 junctionalmore » region. We show that furin cleavage at the modified R667 position generates discrete S1 and S2 subunits and potentiates membrane fusion activity. This effect on the cell-cell fusion activity by the S glycoprotein is not, however, reflected in the infectivity of pseudotyped lentiviruses bearing the cleaved glycoprotein. The lack of effect of furin cleavage on virion infectivity mirrors that observed in the normally cleaved S glycoprotein of the murine coronavirus and highlights an additional level of complexity in coronavirus entry.« less

Generation and characterization of field-emitting surface dielectric barrier discharges in liquids

NASA Astrophysics Data System (ADS)

Kawamura, Tomohisa; Kanno, Moriyuki; Stauss, Sven; Kuribara, Koichi; Pai, David Z.; Ito, Tsuyohito; Terashima, Kazuo

2018-01-01

Field-emitting surface dielectric barrier discharges (FESDBDs), previously generated in CO2 from high pressures up to supercritical conditions using 10 kHz ac excitation, were investigated in non-aqueous liquid CO2 and liquid silicone oil. In both liquids, the maximum amount of negative charge Q-deposited as a function of the applied voltage amplitude was consistent with the Fowler-Nordheim equation, which demonstrated the presence of field emission. Furthermore, purely continuum optical emission spectra attributable to electron-neutral bremsstrahlung were confirmed. The fact that these characteristics were identical to those in high-pressure CO2 reported from previous research shows that FESDBDs can be generated independently of the medium type and that they are low-power (on the order of 10 mW) discharges. To investigate the charging function of FESDBDs, the motion of fine particles suspended above the FESDBDs was studied by high-speed imaging. It revealed that the speed of fine particles affected by the FESDBDs depends on the particle size, the FESDBDs' function being to charge fine particles.

Economic Assessment of Supercritical CO2 Extraction of Waxes as Part of a Maize Stover Biorefinery.

PubMed

Attard, Thomas M; McElroy, Con Robert; Hunt, Andrew J

2015-07-31

To date limited work has focused on assessing the economic viability of scCO2 extraction to obtain waxes as part of a biorefinery. This work estimates the economic costs for wax extraction from maize stover. The cost of manufacture (COM) for maize stover wax extraction was found to be € 88.89 per kg of wax, with the fixed capital investment (FCI) and utility costs (CUT) contributing significantly to the COM. However, this value is based solely on scCO2 extraction of waxes and does not take into account the downstream processing of the biomass following extraction. The cost of extracting wax from maize stover can be reduced by utilizing pelletized leaves and combusting the residual biomass to generate electricity. This would lead to an overall cost of € 10.87 per kg of wax (based on 27% combustion efficiency for electricity generation) and €4.56 per kg of wax (based on 43% combustion efficiency for electricity generation). A sensitivity analysis study showed that utility costs (cost of electricity) had the greatest effect on the COM.

Extraction and Esterification of Low-Titer Short-Chain Volatile Fatty Acids from Anaerobic Fermentation with Ionic Liquids.

PubMed

Andersen, Stephen J; Berton, Jan K E T; Naert, Pieter; Gildemyn, Sylvia; Rabaey, Korneel; Stevens, Christian V

2016-08-23

Ionic liquids can both act as a solvent and mediate esterification to valorize low-titer volatile fatty acids and generate organic solvents from renewable carbon sources including biowaste and CO2 . In this study, four phosphonium ionic liquids were tested for single-stage extraction of acetic acid from a dilute stream and esterification to ethyl acetate with added ethanol and heat. The esterification proceeded with a maximum conversion of 85.9±1.3 % after 30 min at 75 °C at a 1:1 stoichiometric ratio of reactants. Extraction and esterification can be tailored using mixed-anion ionic liquids; this is demonstrated herein using a common trihexyl(tetradecyl)phosphonium cation and a mixed chloride and bis(trifluoromethylsulfonyl)imide anion ionic liquid. As a further proof-of-concept, ethyl acetate was generated from an ionic liquid-driven esterification of an acetic acid extractant generated using CO2 as the only carbon source by microbial electrosynthesis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Case study on incentive mechanism of energy efficiency retrofit in coal-fueled power plant in China.

PubMed

Yuan, Donghai; Guo, Xujing; Cao, Yuan; He, Liansheng; Wang, Jinggang; Xi, Beidou; Li, Junqi; Ma, Wenlin; Zhang, Mingshun

2012-01-01

An ordinary steam turbine retrofit project is selected as a case study; through the retrofit, the project activities will generate emission reductions within the power grid for about 92,463 tCO(2)e per annum. The internal rate of return (IRR) of the project is only -0.41% without the revenue of carbon credits, for example, CERs, which is much lower than the benchmark value of 8%. Only when the unit price of carbon credit reaches 125 CNY/tCO(2), the IRR could reach the benchmark and an effective carbon tax needs to increase the price of carbon to 243 CNY/tce in order to make the project financially feasible. Design of incentive mechanism will help these low efficiency enterprises improve efficiency and reduce CO(2) emissions, which can provide the power plants sufficient incentive to implement energy efficiency retrofit project in existing coal-fuel power generation-units, and we hope it will make a good demonstration for the other low efficiency coal-fueled power generation units in China.

Advanced Acid Gas Separation Technology for the Utilization of Low Rank Coals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kloosterman, Jeff

2012-12-31

Air Products has developed a potentially ground-breaking technology – Sour Pressure Swing Adsorption (PSA) – to replace the solvent-based acid gas removal (AGR) systems currently employed to separate sulfur containing species, along with CO{sub 2} and other impurities, from gasifier syngas streams. The Sour PSA technology is based on adsorption processes that utilize pressure swing or temperature swing regeneration methods. Sour PSA technology has already been shown with higher rank coals to provide a significant reduction in the cost of CO{sub 2} capture for power generation, which should translate to a reduction in cost of electricity (COE), compared to baselinemore » CO{sub 2} capture plant design. The objective of this project is to test the performance and capability of the adsorbents in handling tar and other impurities using a gaseous mixture generated from the gasification of lower rank, lignite coal. The results of this testing are used to generate a high-level pilot process design, and to prepare a techno-economic assessment evaluating the applicability of the technology to plants utilizing these coals.« less

Case Study on Incentive Mechanism of Energy Efficiency Retrofit in Coal-Fueled Power Plant in China

PubMed Central

Yuan, Donghai; Guo, Xujing; Cao, Yuan; He, Liansheng; Wang, Jinggang; Xi, Beidou; Li, Junqi; Ma, Wenlin; Zhang, Mingshun

2012-01-01

An ordinary steam turbine retrofit project is selected as a case study; through the retrofit, the project activities will generate emission reductions within the power grid for about 92,463 tCO2e per annum. The internal rate of return (IRR) of the project is only −0.41% without the revenue of carbon credits, for example, CERs, which is much lower than the benchmark value of 8%. Only when the unit price of carbon credit reaches 125 CNY/tCO2, the IRR could reach the benchmark and an effective carbon tax needs to increase the price of carbon to 243 CNY/tce in order to make the project financially feasible. Design of incentive mechanism will help these low efficiency enterprises improve efficiency and reduce CO2 emissions, which can provide the power plants sufficient incentive to implement energy efficiency retrofit project in existing coal-fuel power generation-units, and we hope it will make a good demonstration for the other low efficiency coal-fueled power generation units in China. PMID:23365532

On a clean power generation system with the co-gasification of biomass and coal in a quadruple fluidized bed gasifier.

PubMed

Yan, Linbo; He, Boshu

2017-07-01

A clean power generation system was built based on the steam co-gasification of biomass and coal in a quadruple fluidized bed gasifier. The chemical looping with oxygen uncoupling technology was used to supply oxygen for the calciner. The solid oxide fuel cell and the steam turbine were combined to generate power. The calcium looping and mineral carbonation were used for CO 2 capture and sequestration. The aim of this work was to study the characteristics of this system. The effects of key operation parameters on the system total energy efficiency (ŋ ten ), total exergy efficiency (ŋ tex ) and carbon sequestration rate (R cs ) were detected. The energy and exergy balance calculations were implemented and the corresponding Sankey and Grassmann diagrams were drawn. It was found that the maximum energy and exergy losses occurred in the steam turbine. The system ŋ ten and ŋ tex could be ∼50% and ∼47%, and R cs could be over unit. Copyright © 2017 Elsevier Ltd. All rights reserved.

Economic Assessment of Supercritical CO2 Extraction of Waxes as Part of a Maize Stover Biorefinery

PubMed Central

Attard, Thomas M.; McElroy, Con Robert; Hunt, Andrew J.

2015-01-01

To date limited work has focused on assessing the economic viability of scCO2 extraction to obtain waxes as part of a biorefinery. This work estimates the economic costs for wax extraction from maize stover. The cost of manufacture (COM) for maize stover wax extraction was found to be €88.89 per kg of wax, with the fixed capital investment (FCI) and utility costs (CUT) contributing significantly to the COM. However, this value is based solely on scCO2 extraction of waxes and does not take into account the downstream processing of the biomass following extraction. The cost of extracting wax from maize stover can be reduced by utilizing pelletized leaves and combusting the residual biomass to generate electricity. This would lead to an overall cost of €10.87 per kg of wax (based on 27% combustion efficiency for electricity generation) and €4.56 per kg of wax (based on 43% combustion efficiency for electricity generation). A sensitivity analysis study showed that utility costs (cost of electricity) had the greatest effect on the COM. PMID:26263976

40 CFR 53.22 - Generation of test atmospheres.

Code of Federal Regulations, 2010 CFR

2010-07-01

... test concentration shall be verified. (b) The test atmosphere delivery system shall be designed and... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Generation of test atmospheres. 53.22... Characteristics of Automated Methods SO2, CO, O3, and NO2 § 53.22 Generation of test atmospheres. (a) Table B-2...

40 CFR 53.22 - Generation of test atmospheres.

Code of Federal Regulations, 2011 CFR

2011-07-01

... test concentration shall be verified. (b) The test atmosphere delivery system shall be designed and... 40 Protection of Environment 5 2011-07-01 2011-07-01 false Generation of test atmospheres. 53.22... Characteristics of Automated Methods SO2, CO, O3, and NO2 § 53.22 Generation of test atmospheres. (a) Table B-2...

Environmental costs resulting from the use of hard coal to electricity generation in Poland

NASA Astrophysics Data System (ADS)

Stala-Szlugaj, Katarzyna; Grudziński, Zbigniew

2017-10-01

In the world's fuel mix used for generating electricity, the most common fossil fuel is coal. In the EU, coal combustion and electricity generation entail the need to purchase emission allowances (EUA) whose purchase costs affect the costs of electricity generation significantly. The research described in the article shows how current market conditions shape the profitability of generating electricity from coal and how Clean Dark Spread (CDS) changes as a function of changes in energy and coal prices at the assumed levels of emission and prices of EUA allowances. The article compares the results of CDS calculations in two variants. Areas have been highlighted where prices of both coal and EUA allowances cause CDS to assume values at which the prices of generated electricity do not cover the costs of fuel (i) and CO2 emission allowances, cover all costs (ii), or constitute positive prices (iii), but still do not cover all fixed costs. With higher power plant efficiency, CO2 emissions are lower (0.722 t/MWh). The costs of purchasing fuel required to generate 1 MWh of electricity are also lower. In such case—even with relatively high prices of coal—a power plant can achieve profitability of electricity generation.

Chemical Synthesis of Next Generation High Energy Product Hybrid SmCo Permanent Magnets for High Temperature Applications

DTIC Science & Technology

2010-08-01

among CoxC, AINiCo and Ba / Sr ferrite magnets. AINiCo is shown to exhibit high (BH)max, 35 kJmŗ, but a low intrinsic coercivity, mostly ə kOe...whereas Ba / Sr ferrite features high intrinsic coercivity, 3-4.5 kOe, but typical values of (BH)max below 25 kJm-3. However, the multiple...coercivity of cobalt carbide nanoparticles is compared with free powders of AINiCo and ceramic magnets of the Ba / Sr hexaferrite type. Curie temperatures near

The Methanol Economy Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olah, George; Prakash, G. K.

2014-02-01

The Methanol Economy Project is based on the concept of replacing fossil fuels with methanol generated either from renewable resources or abundant natural (shale) gas. The full methanol cycle was investigated in this project, from production of methanol through bromination of methane, bireforming of methane to syngas, CO 2 capture using supported amines, co-electrolysis of CO 2 and water to formate and syngas, decomposition of formate to CO 2 and H 2, and use of formic acid in a direct formic acid fuel cell. Each of these projects achieved milestones and provided new insights into their respective fields.

Semiconductor-Based, Solar-Driven Photochemical Cells for Fuel Generation from Carbon Dioxide in Aqueous Solutions.

PubMed

Yehezkeli, Omer; Bedford, Nicholas M; Park, Eunsol; Ma, Ke; Cha, Jennifer N

2016-11-23

There has been active interest to identify new methods to reduce CO 2 into usable fuel sources. In this work, we demonstrate two types of photo-electrochemical cells (PECs) that photoreduce CO 2 directly to formate in aqueous solutions both in the presence and absence of external bias or additional electron sources. The photocathodes were either a CuFeO 2 /CuO electrode or a bilayer of CdTe on NiO, whereas the photoanode was a bilayer of NiO x on CdS. The PECs were characterized by using both electrochemistry and spectroscopy, and the products formed from CO 2 reduction were characterized and quantified by using 1 H NMR spectroscopy and ESI-MS. In addition, an organohydride catalyst was tested in conjunction with the PECs, which not only showed a significant gain of 85 times in CO 2 reduction (27 μm formate without the catalyst, 2.3 mm formate with it) compared to the NiO/CdTe photocathode system but could also generate methanol under an external bias (10 μm). © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Experiments On Sublimating Carbon Dioxide Ice And Implications For Contemporary Surface Processes On Mars.

PubMed

Mc Keown, L E; Bourke, M C; McElwaine, J N

2017-10-27

Carbon dioxide is Mars' primary atmospheric constituent and is an active driver of Martian surface evolution. CO 2 ice sublimation mechanisms have been proposed for a host of features that form in the contemporary Martian climate. However, there has been very little experimental work or quantitative modelling to test the validity of these hypotheses. Here we present the results of the first laboratory experiments undertaken to investigate if the interaction between sublimating CO 2 ice blocks and a warm, porous, mobile regolith can generate features similar in morphology to those forming on Martian dunes today. We find that CO 2 sublimation can mobilise grains to form (i) pits and (ii) furrows. We have documented new detached pits at the termini of linear gullies on Martian dunes. Based on their geomorphic similarity to the features observed in our laboratory experiments, and on scaling arguments, we propose a new hypothesis that detached pits are formed by the impact of granular jets generated by sublimating CO 2 . We also study the erosion patterns formed underneath a sublimating block of CO 2 ice and demonstrate that these resemble furrow patterns on Mars, suggesting similar formation mechanisms.

CO2 Reduction Selective for C≥2 Products on Polycrystalline Copper with N-Substituted Pyridinium Additives.

PubMed

Han, Zhiji; Kortlever, Ruud; Chen, Hsiang-Yun; Peters, Jonas C; Agapie, Theodor

2017-08-23

Electrocatalytic CO 2 reduction to generate multicarbon products is of interest for applications in artificial photosynthetic schemes. This is a particularly attractive goal for CO 2 reduction by copper electrodes, where a broad range of hydrocarbon products can be generated but where selectivity for C-C coupled products relative to CH 4 and H 2 remains an impediment. Herein we report a simple yet highly selective catalytic system for CO 2 reduction to C ≥2 hydrocarbons on a polycrystalline Cu electrode in bicarbonate aqueous solution that uses N-substituted pyridinium additives. Selectivities of 70-80% for C 2 and C 3 products with a hydrocarbon ratio of C ≥2 /CH 4 significantly greater than 100 have been observed with several additives. 13 C-labeling studies verify CO 2 to be the sole carbon source in the C ≥2 hydrocarbons produced. Upon electroreduction, the N-substituted pyridinium additives lead to film deposition on the Cu electrode, identified in one case as the reductive coupling product of N -arylpyridinium. Product selectivity can also be tuned from C ≥2 species to H 2 (∼90%) while suppressing methane with certain N-heterocyclic additives.

Biofilm Removal Using Carbon Dioxide Aerosols without Nitrogen Purge.

PubMed

Hong, Seongkyeol; Jang, Jaesung

2016-11-06

Biofilms can cause serious concerns in many applications. Not only can they cause economic losses, but they can also present a public health hazard. Therefore, it is highly desirable to remove biofilms from surfaces. Many studies on CO2 aerosol cleaning have employed nitrogen purges to increase biofilm removal efficiency by reducing the moisture condensation generated during the cleaning. However, in this study, periodic jets of CO2 aerosols without nitrogen purges were used to remove Pseudomonas putida biofilms from polished stainless steel surfaces. CO2 aerosols are mixtures of solid and gaseous CO2 and are generated when high-pressure CO2 gas is adiabatically expanded through a nozzle. These high-speed aerosols were applied to a biofilm that had been grown for 24 hr. The removal efficiency ranged from 90.36% to 98.29% and was evaluated by measuring the fluorescence intensity of the biofilm as the treatment time was varied from 16 sec to 88 sec. We also performed experiments to compare the removal efficiencies with and without nitrogen purges; the measured biofilm removal efficiencies were not significantly different from each other (t-test, p > 0.55). Therefore, this technique can be used to clean various bio-contaminated surfaces within one minute.

Cu2O-tipped ZnO nanorods with enhanced photoelectrochemical performance for CO2 photoreduction

NASA Astrophysics Data System (ADS)

Iqbal, Muzaffar; Wang, Yanjie; Hu, Haifeng; He, Meng; Hassan Shah, Aamir; Lin, Lin; Li, Pan; Shao, Kunjuan; Reda Woldu, Abebe; He, Tao

2018-06-01

The design of Cu2O-tipped ZnO nanorods is proposed here aiming at enhanced photoelectrochemical properties. The tip-selective deposition of Cu2O is confirmed by scanning transmission electron microscopy (STEM). The photoinduced charge behavior like charge generation, separation and transport has been thoroughly studied by UV-vis absorption analysis and different photoelectrochemical characterizations, including transient photocurrent, incident photon-to-current efficiency (IPCE), electrochemical impedance spectroscopy (EIS), intensity-modulated photocurrent spectroscopy (IMPS), and Mott-Schottky measurements. The photoelectrochemical characterizations clearly indicate that ZnO/Cu2O structures exhibit much higher performance than pristine ZnO, due to the formation of p-n junction, as well as the tip selective growth of Cu2O on ZnO. Photocatalytic CO2 reduction in aqueous solution under UV-visible light illumination shows that CO is the main product, and with the increase of the Cu2O content in the heterostructure, the CO yield increases. This work shows that Cu2O-tipped ZnO nanorods possess improved behavior of charge generation, separation and transport, which may work as a potential candidate for photocatalytic CO2 reduction.

Mechanism for DNA transposons to generate introns on genomic scales

PubMed Central

Huff, Jason T.; Zilberman, Daniel; Roy, Scott W.

2017-01-01

Discovered four decades ago, the existence of introns was one of the most unexpected findings in molecular biology1. Introns are sequences interrupting genes that must be removed as part of mRNA production. Genome sequencing projects have documented that most eukaryotic genes contain at least one and frequently many introns2,3. Comparison of these genomes reveals a history of long evolutionary periods with little intron gain punctuated by episodes of rapid, extensive gain2,3. However, no detailed mechanism for such episodic intron generation has been empirically supported on a sufficient scale, despite several proposals4–8. Here we show how short non-autonomous DNA transposons independently generated hundreds to thousands of introns in the prasinophyte Micromonas pusilla and the pelagophyte Aureococcus anophagefferens. Each transposon carries one splice site. The other splice site is co-opted from gene sequence duplicated upon transposon insertion, allowing perfect splicing out of RNA. The distributions of sequences that can be co-opted are biased with respect to codons, and phasing of transposon-generated introns is similarly biased. These transposons insert between preexisting nucleosomes, so that multiple nearby insertions generate nucleosome-sized intervening segments. Thus, transposon insertion and sequence co-option may explain the intron phase biases2 and prevalence of nucleosome-sized exons9 observed in eukaryotes. Overall, the two independent examples of proliferating elements illustrate a general DNA transposon mechanism plausibly accounting for episodes of rapid, extensive intron gain during eukaryotic evolution2,3. PMID:27760113

Preparatory co-activation of the ankle muscles may prevent ankle inversion injuries

PubMed Central

DeMers, Matthew S.; Hicks, Jennifer L.; Delp, Scott L.

2018-01-01

Ankle inversion sprains are the most frequent acute musculoskeletal injuries occurring in physical activity. Interventions that retrain muscle coordination have helped rehabilitate injured ankles, but it is unclear which muscle coordination strategies, if any, can prevent ankle sprains. The purpose of this study was to determine whether coordinated activity of the ankle muscles could prevent excessive ankle inversion during a simulated landing on a 30-degree incline. We used a set of musculoskeletal simulations to evaluate the efficacy of two strategies for coordinating the ankle evertor and invertor muscles during simulated landing scenarios: planned co-activation and stretch reflex activation with physiologic latency (60-millisecond delay). A full-body musculoskeletal model of landing was used to generate simulations of a subject dropping onto an inclined surface with each coordination condition. Within each condition, the intensity of evertor and invertor co-activity or stretch reflexes were varied systematically. The simulations revealed that strong preparatory co-activation of the ankle evertors and invertors prior to ground contact prevented ankle inversion from exceeding injury thresholds by rapidly generating eversion moments after initial contact. Conversely, stretch reflexes were too slow to generate eversion moments before the simulations reached the threshold for inversion injury. These results suggest that training interventions to protect the ankle should focus on stiffening the ankle with muscle co-activation prior to landing. The musculoskeletal models, controllers, software, and simulation results are freely available online at http://simtk.org/home/ankle-sprains, enabling others to reproduce the results and explore new injury scenarios and interventions. PMID:28057351

The Value of Clean Air

NASA Astrophysics Data System (ADS)

Shindell, D. T.

2014-12-01

How can society place a value on clean air? I present a multi-impact economic valuation framework called the Social Cost of Atmospheric Release (SCAR) that extends the Social Cost of Carbon (SCC) used previously for carbon dioxide (CO2) to a broader range of pollutants and impacts. Values consistently incorporate health impacts of air quality along with climate damages. The latter include damages associated with aerosol-induced hydrologic cycle changes that lead to net climate benefits when reducing cooling aerosols. Evaluating a 1% reduction in current global emissions, benefits with a high discount rate are greatest for reductions of co-emitted products of incomplete combustion (PIC), followed by sulfur dioxide (SO2), nitrogen oxides (NOx) and then CO2, ammonia and methane. With a low discount rate, benefits are greatest for CO2 reductions, though the sum of SO2, PIC and methane is substantially larger. These results suggest that efforts to mitigate atmosphere-related environmental damages should target a broad set of emissions including CO2, methane and aerosol/ozone precursors. Illustrative calculations indicate environmental damages are 410-1100 billion yr-1 for current US electricity generation ( 19-46¢ per kWh for coal, 4-24¢ for gas) and 3.80 (-1.80/+2.10) per gallon of gasoline ($4.80 (-3.10/+3.50) per gallon for diesel). These results suggest that total atmosphere-related environmental damages plus generation costs are much greater for coal-fired power than other types of electricity generation, and that damages associated with gasoline vehicles substantially exceed those for electric vehicles.

Knowledge of response location alone is not sufficient to generate social inhibition of return.

PubMed

Welsh, Timothy N; Manzone, Joseph; McDougall, Laura

2014-11-01

Previous research has revealed that the inhibition of return (IOR) effect emerges when individuals respond to a target at the same location as their own previous response or the previous response of a co-actor. The latter social IOR effect is thought to occur because the observation of co-actor's response evokes a representation of that action in the observer and that the observation-evoked response code subsequently activates the inhibitory mechanisms underlying IOR. The present study was conducted to determine if knowledge of the co-actor's response alone is sufficient to evoke social IOR. Pairs of participants completed responses to targets that appeared at different button locations. Button contact generated location-contingent auditory stimuli (high and low tones in Experiment 1 and colour words in Experiment 2). In the Full condition, the observer saw the response and heard the auditory stimuli. In the Auditory Only condition, the observer did not see the co-actor's response, but heard the auditory stimuli generated via button contact to indicate response endpoint. It was found that, although significant individual and social IOR effects emerged in the Full conditions, there were no social IOR effects in the Auditory Only conditions. These findings suggest that knowledge of the co-actor's response alone via auditory information is not sufficient to activate the inhibitory processes leading to IOR. The activation of the mechanisms that lead to social IOR seems to be dependent on processing channels that code the spatial characteristics of action. Copyright © 2014 Elsevier B.V. All rights reserved.

Low-coordinated surface atoms of CuPt alloy cocatalysts on TiO2 for enhanced photocatalytic conversion of CO2.

PubMed

Lee, Sooho; Jeong, Sunil; Kim, Whi Dong; Lee, Seokwon; Lee, Kangha; Bae, Wan Ki; Moon, Jun Hyuk; Lee, Sangheon; Lee, Doh C

2016-05-21

We report the photocatalytic conversion of CO2 to CH4 using CuPt alloy nanoclusters anchored on TiO2. As the size of CuPt alloy nanoclusters decreases, the photocatalytic activity improves significantly. Small CuPt nanoclusters strongly bind CO2 intermediates and have a stronger interaction with the TiO2 support, which also contributes to an increased CH4 generation rate. The alloying and size effects prove to be the key to efficient CO2 reduction, highlighting a strategic platform for the design of photocatalysts for CO2 conversion.

Army Generating Force Census Utilization. FY2008 Summer Study

DTIC Science & Technology

2009-10-01

TD 󈧻 -a ^ 01 3 3" 𔃽 3 QJ <j IH b rj •3 re .£ > OJ re a re (— ft- c g...73 £ rn H QJ -3 QJ J3 co Ŗ •*•’ ro 3 •_ .a - Si «o 2 g.| S c x > 2 2 O £ Q. QJ .£ o X ft- 3 TD O 3 co re QJ IH X T3 >H...co to 󈧻 — _>» TD c 5 < CO 75 CD .2 II CO o n LJ- LL U O • c CD E CD O) 03 c 03 CD o CL c

Iron Porphyrins Embedded into a Supramolecular Porous Organic Cage for Electrochemical CO2 Reduction in Water.

PubMed

Smith, Peter T; Benke, Bahiru Punja; Cao, Zhi; Kim, Younghoon; Nichols, Eva M; Kim, Kimoon; Chang, Christopher J

2018-06-19

We report the use of a porous organic cage composed of six iron tetraphenylporphyrins as a supramolecular catalyst for electrochemical CO2-to-CO conversion. This strategy enhances active site exposure and substrate diffusion relative to the monomeric catalyst, resulting in CO generation with near-quantitative Faradaic efficiency in pH 7.3 water, with activities reaching 55,250 turnovers. These results provide a starting point for the design of supramolecular catalysts that can exploit the properties of the surrounding matrix yet retain the tunability of the original molecular unit. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

MYSID TWO-GENERATION TEST GUIDELINE

EPA Science Inventory

McKenney, Charles L., Jr. In press. Mysid Two-Generation Test Guideline. OECD Expert Group on Invertebrate Testing for Endocrine Disruptors, Organisation for Economic Co-operation and Development, Paris, France. 17 p. (ERL,GB 1215).

This guideline describes a two-generati...

Materials Innovation for Next-Generation T&D Grid Components. Workshop Summary Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, Emmanuel; Kramer, Caroline; Marchionini, Brian

The Materials Innovations for Next-Generation T&D Grid Components Workshop was co-sponsored by the U.S. Department of Energy (DOE) Office of Electricity Delivery and Energy Reliability and the Oak Ridge National Laboratory (ORNL) and held on August 26 27, 2015, at the ORNL campus in Oak Ridge, Tennessee. The workshop was planned and executed under the direction of workshop co-chair Dr. Kerry Cheung (DOE) and co-chair Dr. Dominic Lee (ORNL). The information contained herein is based on the results of the workshop, which was attended by nearly 50 experts from government, industry, and academia. The research needs and pathways described inmore » this report reflect the expert opinions of workshop participants, but they are not intended to represent the views of the entire electric power community.« less

SFG spectroscopy from 10 -8 to 1000 mbar: less-ordered CO structures and coadsorption on Pd (1 1 1)

NASA Astrophysics Data System (ADS)

Morkel, Matthias; Unterhalt, Holger; Salmeron, Miquel; Rupprechter, Günther; Freund, Hans-Joachim

2003-06-01

Vibrational sum frequency generation spectroscopy was employed to study "less-ordered" phases resulting from low-temperature CO exposure on Pd(1 1 1). Such imperfect structures may also occur under catalytic reaction conditions up to 1000 mbar and originate from the superposition of ordered structures when the CO mobility and flux were insufficient. The effect of coadsorbed hydrogen and water was also examined.

Co-Creation and Open Innovation: Systematic Literature Review

ERIC Educational Resources Information Center

Ramírez, María-Soledad; García-Peñalvo, Francisco-José

2018-01-01

Open science, as a common good, opens possibilities for the development of nations, through innovations and collaborative constructions, which help to democratize knowledge. Advances in this area are still emerging, and the open science, co-creation of knowledge and open innovation triangle, is presented as an opportunity to generate an original…

Alternative Fuels Data Center

Science.gov Websites

include any fuel derived from co-processing biomass with a feedstock that is not biomass. This tax credit renewable diesel does not include any fuel derived from co-processing biomass with a feedstock that is not ) Second Generation Biofuel Production Property Depreciation Allowance Expired: 12/31/2017 NOTE: This

Gopherus agassizii (desert tortoise) and Crotalus ruber (red diamond rattlesnake). Burrow co-occupancy

USGS Publications Warehouse

Lovich, Jeffrey E.

2011-01-01

I observed an adult Desert Tortoise and an adult Red Diamond Rattlesnake (sexes unknown) in a shallow tortoise burrow on 6 January 1997 at a wind energy generation facility near Palm Springs, Riverside Co., California, USA (33.9599°N, 116.6613°W).

A statistical analysis of three ensembles of crop model responses to temperature and CO2 concentration

USDA-ARS?s Scientific Manuscript database

Ensembles of process-based crop models are now commonly used to simulate crop growth and development for climate scenarios of temperature and/or precipitation changes corresponding to different projections of atmospheric CO2 concentrations. This approach generates large datasets with thousands of de...

Poly(butylene adipate-co-terephthalate) and sunflower head residue composites: Effects of composition and compatibilization on properties

USDA-ARS?s Scientific Manuscript database

Utilizing the abundant byproducts generated from processing of agricultural materials has sustainable and cost–saving potential benefits. In this work, Sunflower Head Residues (SHR) in 3 different compositions were introduced into biodegradable Poly(butylene adipate-co-terephthalate) (PBAT) matrices...

Micro Power

DTIC Science & Technology

2004-02-01

GENERATOR ENERGIZED BY A MEMS BASED CHEMICAL- THERMAL REACTOR” 5-6 PI: Professor Robert F. Savinell Co-I(s): Professors C. C. Liu, M. H . Litt, and J. S...January 8, 2002 PI Chih-Ming Ho UCLA Yu-Chong Tai Caltech Siegfried Janson Henry Helvajian Aerospace Corporation H.Q. Yang Andrzej J. Przekwasa CFDRC Co

Leadership Self-Efficacy in University Co-Curricular Programs

ERIC Educational Resources Information Center

Fields, Andrew R.

2010-01-01

University educators are concerned with student leadership development in order to generate much-needed leaders in every aspect of society. This sequential mixed methods study found that students who participate in a university co-curricular outdoor education leadership training program, combined with the experience of leading a wilderness…

77 FR 68783 - Prospective Grant of Co-Exclusive License: Veterinary Vaccines for Rift Valley Fever Virus

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-16

... Grant of Co-Exclusive License: Veterinary Vaccines for Rift Valley Fever Virus AGENCY: Centers for... veterinary vaccines, to practice the inventions listed in the patent applications referred to below to... generation of precisely defined attenuated vaccine constructs that contain complete deletions of critical...

Observational constraints on the global atmospheric CO2 budget

NASA Technical Reports Server (NTRS)

Tans, Pieter P.; Fung, Inez Y.; Takahashi, Taro

1990-01-01

Observed atmospheric concentrations of CO2 and data on the partial pressures of CO2 in surface ocean waters are combined to identify globally significant sources and sinks of CO2. The atmospheric data are compared with boundary layer concentrations calculated with the transport fields generated by a general circulation model (GCM) for specified source-sink distributions. In the model the observed north-south atmospheric concentration gradient can be maintained only if sinks for CO2 are greater in the Northern than in the Southern Hemisphere. The observed differences between the partial pressure of CO2 in the surface waters of the Northern Hemisphere and the atmosphere are too small for the oceans to be the major sink of fossil fuel CO2. Therefore, a large amount of the CO2 is apparently absorbed on the continents by terrestrial ecosystems.

Current state of coenzyme Q(10) production and its applications.

PubMed

Jeya, Marimuthu; Moon, Hee-Jung; Lee, Jeong-Lim; Kim, In-Won; Lee, Jung-Kul

2010-02-01

Coenzyme Q(10) (CoQ(10)), an obligatory cofactor in the aerobic respiratory electron transfer for energy generation, is formed from the conjugation of a benzoquinone ring with a hydrophobic isoprenoid chain. CoQ(10) is now used as a nutritional supplement because of its antioxidant properties and is beneficial in the treatment of several human diseases when administered orally. Bioprocesses have been developed for the commercial production of CoQ(10) because of its increased demand, and these bioprocesses depend on microbes that produce high levels of CoQ(10) naturally. However, as knowledge of the biosynthetic enzymes and the regulatory mechanisms modulating CoQ(10) production increases, approaches arise for the genetic engineering of CoQ(10) production in Escherichia coli and Agrobacterium tumefaciens. This review focused on approaches for CoQ(10) production, strategies used to engineer CoQ(10) production in microbes, and potential applications of CoQ(10).

Carbon footprint assessment of Western Australian Groundwater Recycling Scheme

NASA Astrophysics Data System (ADS)

Simms, Andrew; Hamilton, Stacey; Biswas, Wahidul K.

2017-04-01

This research has determined the carbon footprint or the carbon dioxide equivalent (CO2 eq) of potable water production from a groundwater recycling scheme, consisting of the Beenyup wastewater treatment plant, the Beenyup groundwater replenishment trial plant and the Wanneroo groundwater treatment plant in Western Australia, using a life cycle assessment approach. It was found that the scheme produces 1300 tonnes of CO2 eq per gigalitre (GL) of water produced, which is 933 tonnes of CO2 eq higher than the desalination plant at Binningup in Western Australia powered by 100% renewable energy generated electricity. A Monte Carlo Simulation uncertainty analysis calculated a Coefficient of Variation value of 5.4%, thus confirming the accuracy of the simulation. Electricity input accounts for 83% of the carbon dioxide equivalent produced during the production of potable water. The chosen mitigation strategy was to consider the use of renewable energy to generate electricity for carbon intensive groundwater replenishment trial plant. Depending on the local situation, a maximum of 93% and a minimum of 21% greenhouse gas saving from electricity use can be attained at groundwater replenishment trial plant by replacing grid electricity with renewable electricity. In addition, the consideration of vibrational separation (V-Sep) that helps reduce wastes generation and chemical use resulted in a 4.03 tonne of CO2 eq saving per GL of water produced by the plant.

Production of biodiesel from microalgae through biological carbon capture: a review.

PubMed

Mondal, Madhumanti; Goswami, Shrayanti; Ghosh, Ashmita; Oinam, Gunapati; Tiwari, O N; Das, Papita; Gayen, K; Mandal, M K; Halder, G N

2017-06-01

Gradual increase in concentration of carbon dioxide (CO 2 ) in the atmosphere due to the various anthropogenic interventions leading to significant alteration in the global carbon cycle has been a subject of worldwide attention and matter of potential research over the last few decades. In these alarming scenario microalgae seems to be an attractive medium for capturing the excess CO 2 present in the atmosphere generated from different sources such as power plants, automobiles, volcanic eruption, decomposition of organic matters and forest fires. This captured CO 2 through microalgae could be used as potential carbon source to produce lipids for the generation of biofuel for replacing petroleum-derived transport fuel without affecting the supply of food and crops. This comprehensive review strives to provide a systematic account of recent developments in the field of biological carbon capture through microalgae for its utilization towards the generation of biodiesel highlighting the significance of certain key parameters such as selection of efficient strain, microalgal metabolism, cultivation systems (open and closed) and biomass production along with the national and international biodiesel specifications and properties. The potential use of photobioreactors for biodiesel production under the influence of various factors viz., light intensity, pH, time, temperature, CO 2 concentration and flow rate has been discussed. The review also provides an economic overview and future outlook on biodiesel production from microalgae.

Carbon footprint assessment of Western Australian Groundwater Recycling Scheme.

PubMed

Simms, Andrew; Hamilton, Stacey; Biswas, Wahidul K

2017-04-01

This research has determined the carbon footprint or the carbon dioxide equivalent (CO 2 eq) of potable water production from a groundwater recycling scheme, consisting of the Beenyup wastewater treatment plant, the Beenyup groundwater replenishment trial plant and the Wanneroo groundwater treatment plant in Western Australia, using a life cycle assessment approach. It was found that the scheme produces 1300 tonnes of CO 2 eq per gigalitre (GL) of water produced, which is 933 tonnes of CO 2 eq higher than the desalination plant at Binningup in Western Australia powered by 100% renewable energy generated electricity. A Monte Carlo Simulation uncertainty analysis calculated a Coefficient of Variation value of 5.4%, thus confirming the accuracy of the simulation. Electricity input accounts for 83% of the carbon dioxide equivalent produced during the production of potable water. The chosen mitigation strategy was to consider the use of renewable energy to generate electricity for carbon intensive groundwater replenishment trial plant. Depending on the local situation, a maximum of 93% and a minimum of 21% greenhouse gas saving from electricity use can be attained at groundwater replenishment trial plant by replacing grid electricity with renewable electricity. In addition, the consideration of vibrational separation (V-Sep) that helps reduce wastes generation and chemical use resulted in a 4.03 tonne of CO 2 eq saving per GL of water produced by the plant.

Solar thermochemical splitting of water to generate hydrogen

PubMed Central

Rao, C. N. R.; Dey, Sunita

2017-01-01

Solar photochemical means of splitting water (artificial photosynthesis) to generate hydrogen is emerging as a viable process. The solar thermochemical route also promises to be an attractive means of achieving this objective. In this paper we present different types of thermochemical cycles that one can use for the purpose. These include the low-temperature multistep process as well as the high-temperature two-step process. It is noteworthy that the multistep process based on the Mn(II)/Mn(III) oxide system can be carried out at 700 °C or 750 °C. The two-step process has been achieved at 1,300 °C/900 °C by using yttrium-based rare earth manganites. It seems possible to render this high-temperature process as an isothermal process. Thermodynamics and kinetics of H2O splitting are largely controlled by the inherent redox properties of the materials. Interestingly, under the conditions of H2O splitting in the high-temperature process CO2 can also be decomposed to CO, providing a feasible method for generating the industrially important syngas (CO+H2). Although carbonate formation can be addressed as a hurdle during CO2 splitting, the problem can be avoided by a suitable choice of experimental conditions. The choice of the solar reactor holds the key for the commercialization of thermochemical fuel production. PMID:28522461

Prevascularization of 3D printed bone scaffolds by bioactive hydrogels and cell co-culture.

PubMed

Kuss, Mitchell A; Wu, Shaohua; Wang, Ying; Untrauer, Jason B; Li, Wenlong; Lim, Jung Yul; Duan, Bin

2017-09-13

Vascularization is a fundamental prerequisite for large bone construct development and remains one of the main challenges of bone tissue engineering. Our current study presents the combination of 3D printing technique with a hydrogel-based prevascularization strategy to generate prevascularized bone constructs. Human adipose derived mesenchymal stem cells (ADMSC) and human umbilical vein endothelial cells (HUVEC) were encapsulated within our bioactive hydrogels, and the effects of culture conditions on in vitro vascularization were determined. We further generated composite constructs by forming 3D printed polycaprolactone/hydroxyapatite scaffolds coated with cell-laden hydrogels and determined how the co-culture affected vascularization and osteogenesis. It was demonstrated that 3D co-cultured ADMSC-HUVEC generated capillary-like networks within the porous 3D printed scaffold. The co-culture systems promoted in vitro vascularization, but had no significant effects on osteogenesis. The prevascularized constructs were subcutaneously implanted into nude mice to evaluate the in vivo vascularization capacity and the functionality of engineered vessels. The hydrogel systems facilitated microvessel and lumen formation and promoted anastomosis of vascular networks of human origin with host murine vasculature. These findings demonstrate the potential of prevascularized 3D printed scaffolds with anatomical shape for the healing of larger bone defects. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017. © 2017 Wiley Periodicals, Inc.

In-plane current-driven spin-orbit torque switching in perpendicularly magnetized films with enhanced thermal tolerance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Di; Department of Optical Science and Engineering, Key Laboratory of Micro and Nano Photonic Structures; Yu, Guoqiang, E-mail: guoqiangyu@ucla.edu

2016-05-23

We study spin-orbit-torque (SOT)-driven magnetization switching in perpendicularly magnetized Ta/Mo/Co{sub 40}Fe{sub 40}B{sub 20} (CoFeB)/MgO films. The thermal tolerance of the perpendicular magnetic anisotropy (PMA) is enhanced, and the films sustain the PMA at annealing temperatures of up to 430 °C, due to the ultra-thin Mo layer inserted between the Ta and CoFeB layers. More importantly, the Mo insertion layer also allows for the transmission of the spin current generated in the Ta layer due to spin Hall effect, which generates a damping-like SOT and is able to switch the perpendicular magnetization. When the Ta layer is replaced by a Pt layer,more » i.e., in a Pt/Mo/CoFeB/MgO multilayer, the direction of the SOT-induced damping-like effective field becomes opposite because of the opposite sign of spin Hall angle in Pt, which indicates that the SOT-driven switching is dominated by the spin current generated in the Ta or Pt layer rather than the Mo layer. Quantitative characterization through harmonic measurements reveals that the large SOT effective field is preserved for high annealing temperatures. This work provides a route to applying SOT in devices requiring high temperature processing steps during the back-end-of-line processes.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Komiyama, Ryoichi; Marnay, Chris; Stadler, Michael

In this analysis, the authors projected Japan's energy demand/supply and energy-related CO{sub 2} emissions to 2050. Their analysis of various scenarios indicated that Japan's CO{sub 2} emissions in 2050 could be potentially reduced by 26-58% from the current level (FY 2005). These results suggest that Japan could set a CO{sub 2} emission reduction target for 2050 at between 30% and 60%. In order to reduce CO{sub 2} emissions by 60% in 2050 from the present level, Japan will have to strongly promote energy conservation at the same pace as an annual rate of 1.9% after the oil crises (to cutmore » primary energy demand per GDP (TPES/GDP) in 2050 by 60% from 2005) and expand the share of non-fossil energy sources in total primary energy supply in 2050 to 50% (to reduce CO{sub 2} emissions per primary energy demand (CO{sub 2}/TPES) in 2050 by 40% from 2005). Concerning power generation mix in 2050, nuclear power will account for 60%, solar and other renewable energy sources for 20%, hydro power for 10% and fossil-fired generation for 10%, indicating substantial shift away from fossil fuel in electric power supply. Among the mitigation measures in the case of reducing CO{sub 2} emissions by 60% in 2050, energy conservation will make the greatest contribution to the emission reduction, being followed by solar power, nuclear power and other renewable energy sources. In order to realize this massive CO{sub 2} abatement, however, Japan will have to overcome technological and economic challenges including the large-scale deployment of nuclear power and renewable technologies.« less

Design of experiment analysis of CO2 dielectric barrier discharge conditions on CO production

NASA Astrophysics Data System (ADS)

Becker, Markus; Ponduri, Srinath; Engeln, Richard; van de Sanden, Richard; Loffhagen, Detlef

2016-09-01

Dielectric barrier discharges (DBD) are frequently used for the generation of CO from CO2 which is of particular interest for syngas production. It has been found by means of fluid modelling in that the CO2 conversion frequency in a CO2 DBD depends linearly on the specific energy input (SEI) while the energy efficiency of CO production is only weakly dependent on the SEI. Here, the same numerical model as in is applied to study systematically the influence of gas pressure, applied voltage amplitude and frequency on the CO2 conversion frequency and the energy efficiency of CO production based on a 2-level 3-factor full factorial experimental design. It is found that the operating conditions of the CO2 DBD for CO production can be chosen to either have an optimal throughput or a better energy efficiency. This work was partly supported by the German Research Foundation within the Collaborative Research Centre Transregio 24.

Naturally acidified habitat selects for ocean acidification-tolerant mussels.

PubMed

Thomsen, Jörn; Stapp, Laura S; Haynert, Kristin; Schade, Hanna; Danelli, Maria; Lannig, Gisela; Wegner, K Mathias; Melzner, Frank

2017-04-01

Ocean acidification severely affects bivalves, especially their larval stages. Consequently, the fate of this ecologically and economically important group depends on the capacity and rate of evolutionary adaptation to altered ocean carbonate chemistry. We document successful settlement of wild mussel larvae ( Mytilus edulis ) in a periodically CO 2 -enriched habitat. The larval fitness of the population originating from the CO 2 -enriched habitat was compared to the response of a population from a nonenriched habitat in a common garden experiment. The high CO 2 -adapted population showed higher fitness under elevated P co 2 (partial pressure of CO 2 ) than the non-adapted cohort, demonstrating, for the first time, an evolutionary response of a natural mussel population to ocean acidification. To assess the rate of adaptation, we performed a selection experiment over three generations. CO 2 tolerance differed substantially between the families within the F 1 generation, and survival was drastically decreased in the highest, yet realistic, P co 2 treatment. Selection of CO 2 -tolerant F 1 animals resulted in higher calcification performance of F 2 larvae during early shell formation but did not improve overall survival. Our results thus reveal significant short-term selective responses of traits directly affected by ocean acidification and long-term adaptation potential in a key bivalve species. Because immediate response to selection did not directly translate into increased fitness, multigenerational studies need to take into consideration the multivariate nature of selection acting in natural habitats. Combinations of short-term selection with long-term adaptation in populations from CO 2 -enriched versus nonenriched natural habitats represent promising approaches for estimating adaptive potential of organisms facing global change.

Synthesis and characterization of fac-[M(CO)3(P)(OO)] and cis-trans-[M(CO)2(P)2(OO)] complexes (M = Re, (99m)Tc) with acetylacetone and curcumin as OO donor bidentate ligands.

PubMed

Triantis, Charalampos; Tsotakos, Theodoros; Tsoukalas, Charalampos; Sagnou, Marina; Raptopoulou, Catherine; Terzis, Aris; Psycharis, Vassilis; Pelecanou, Maria; Pirmettis, Ioannis; Papadopoulos, Minas

2013-11-18

The synthesis and characterization of neutral mixed ligand complexes fac-[M(CO)3(P)(OO)] and cis-trans-[M(CO)2(P)2(OO)] (M = Re, (99m)Tc), with deprotonated acetylacetone or curcumin as the OO donor bidentate ligands and a phosphine (triphenylphosphine or methyldiphenylphosphine) as the monodentate P ligand, is described. The complexes were synthesized through the corresponding fac-[M(CO)3(H2O)(OO)] (M = Re, (99m)Tc) intermediate aqua complex. In the presence of phosphine, replacement of the H2O molecule of the intermediate complex at room temperature generates the neutral tricarbonyl monophosphine fac-[Re(CO)3(P)(OO)] complex, while under reflux conditions further replacement of the trans to the phosphine carbonyl generates the new stable dicarbonyl bisphosphine complex cis-trans-[Re(CO)2(P)2(OO)]. The Re complexes were fully characterized by elemental analysis, spectroscopic methods, and X-ray crystallography showing a distorted octahedral geometry around Re. Both the monophosphine and the bisphosphine complexes of curcumin show selective binding to β-amyloid plaques of Alzheimer's disease. At the (99m)Tc tracer level, the same type of complexes, fac-[(99m)Tc(CO)3(P)(OO)] and cis-trans-[(99m)Tc(CO)2(P)2(OO)], are formed introducing new donor combinations for (99m)Tc(I). Overall, β-diketonate and phosphine constitute a versatile ligand combination for Re(I) and (99m)Tc(I), and the successful employment of the multipotent curcumin as β-diketone provides a solid example of the pharmacological potential of this system.

MERS-CoV Accessory ORFs Play Key Role for Infection and Pathogenesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Menachery, Vineet D.; Mitchell, Hugh D.; Cockrell, Adam S.

ABSTRACT While dispensable for viral replication, coronavirus (CoV) accessory open reading frame (ORF) proteins often play critical roles during infection and pathogenesis. Utilizing a previously generated mutant, we demonstrate that the absence of all four Middle East respiratory syndrome CoV (MERS-CoV) accessory ORFs (deletion of ORF3, -4a, -4b, and -5 [dORF3-5]) has major implications for viral replication and pathogenesis. Importantly, attenuation of the dORF3-5 mutant is primarily driven by dysregulated host responses, including disrupted cell processes, augmented interferon (IFN) pathway activation, and robust inflammation.In vitroreplication attenuation also extends toin vivomodels, allowing use of dORF3-5 as a live attenuated vaccine platform.more » Finally, examination of ORF5 implicates a partial role in modulation of NF-κB-mediated inflammation. Together, the results demonstrate the importance of MERS-CoV accessory ORFs for pathogenesis and highlight them as potential targets for surveillance and therapeutic treatments moving forward. IMPORTANCEThe initial emergence and periodic outbreaks of MERS-CoV highlight a continuing threat posed by zoonotic pathogens to global public health. In these studies, mutant virus generation demonstrates the necessity of accessory ORFs in regard to MERS-CoV infection and pathogenesis. With this in mind, accessory ORF functions can be targeted for both therapeutic and vaccine treatments in response to MERS-CoV and related group 2C coronaviruses. In addition, disruption of accessory ORFs in parallel may offer a rapid response platform to attenuation of future emergent strains based on both SARS- and MERS-CoV accessory ORF mutants.« less

Fabrication and characterization of solid oxide cells for energy conversion and storage

NASA Astrophysics Data System (ADS)

Yang, Chenghao

2011-12-01

There has been an increasing interest in clean and renewable energy generation for highlighted energy and environmental concerns. Solid oxide cells (SOCs) have been considered as one of the promising technologies, since they can be operated efficiently both in electrolysis mode by generating hydrogen through steam electrolysis and fuel cell mode by electrochemically combining fuel with oxidant. The present work is devoted to performing a fundamental study of SOC in both fuel cell mode for power generation and electrolysis mode for fuel production. The research work on SOCs that can be operated reversibly for power generation and fuel production has been conducted in the following six projects: (1) High performance solid oxide electrolysis cell (SOEC) Fabrication of novel structured SOEC oxygen electrode with the conventional and commercial solid oxide fuel cell materials by screen-printing and infiltration fabrication methods. The microstructure, electrochemical properties and durability of SOECs has been investigated. It was found that the LSM infiltrated cell has an area specific resistance (ASR) of 0.20 Ω cm2 at 900°C at open circuit voltage with 50% absolute humidity (AH), which is relatively lower than that of the cell with LSM-YSZ oxygen electrode made by a conventional mixing method. Electrolysis cell with LSM infiltrated oxygen electrode has demonstrated stable performance under electrolysis operation with 0.33 A/cm2 and 50 vol.% AH at 800°C. (2) Advanced performance high temperature micro-tubular solid oxide fuel cell (MT-SOFC) Phase-inversion, dip-coating, high temperature co-sintering process and impregnation method were used to fabricate micro-tubular solid oxide fuel cell. The micro-structure of the micro-tubular fuel cell will be investigated and the power output and thermal robustness has been evaluated. High performance and rapid start-up behavior have been achieved, indicates that the MT-SOFC developed in this work can be a promising technology for portable applications. (3) Promising intermediate temperature micro-tubular solid oxide fuel cells for portable power supply applications Maximum power densities of 0.5, 0.38 and 0.27 W/cm2 have been obtained using H2-15% H2O as fuel at 550, 600 and 650°C, respectively. Quick thermal cycles performed on the intermediate temperature MT-SOFC stability demonstrate that the cell has robust performance stability for portable applications. (4) Micro-tubular solid oxide cell (MT-SOC) for steam electrolysis The electrochemical properties of MT-SOC will be investigated in detail in electrolysis mode. The mechanism of the novel hydrogen electrode structure benefiting the cell performance will be demonstrated systematically. The high electrochemical performance of the MT-SOC in electrolysis mode indicates that MT-SOC can provide an efficient hydrogen generation process. (5) Micro-tubular solid oxide cell (MT-SOC) for steam and CO2 co-electrolysis The MT-SOC will be operated in co-electrolysis mode for steam and CO 2, which will provide an efficient approach to generate syngas (H2+CO) without consuming fossil fuels. This can potentially provide an alternative superior approach for carbon sequestration which has been a critical issue facing the sustainability of our society. (6) Steam and CO2 co-electrolysis using solid oxide cells fabricated by freeze-drying tape-casting Tri-layer scaffolds have been prepared by freeze-drying tape casting process and the electrode catalysts are obtained by infiltrating the porous electrode substrates. Button cells will be tested for co-electrolysis of steam and CO2. The mechanism and efficiency of steam and CO2 co-electrolysis will be systemically investigated. In conclusion, SOCs have been fabricated with conventional materials and evaluated, but their performance has been found to be limited in either SOFC or SOEC mode. The cell performance has been significantly improved by employing an infiltrated LSM-YSZ electrode, due to dramatically decreased polarization resistance. However, mass transport limitation has been observed, particularly in electrolysis mode. By utilizing micro-tubular SOCs with novel hydrogen electrode produced via a phase inversion method, mass transport limitation has been mitigated. Finally, mass transport has been further improved by using cells with electrodes fabricated through a freeze-drying tape-casting method. (Abstract shortened by UMI.)

Straightforward Generation of Pillared, Microporous Graphene Frameworks for Use in Supercapacitors.

PubMed

Yuan, Kai; Xu, Yazhou; Uihlein, Johannes; Brunklaus, Gunther; Shi, Lei; Heiderhoff, Ralf; Que, Mingming; Forster, Michael; Chassé, Thomas; Pichler, Thomas; Riedl, Thomas; Chen, Yiwang; Scherf, Ullrich

2015-11-01

Microporous, pillared graphene-based frameworks are generated in a simple functionalization/coupling procedure starting from reduced graphene oxide. They are used for the fabrication of high-performance supercapacitor devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eisenhart, Reed J.; Carlson, Rebecca K.; Clouston, Laura J.

Heterobimetallic complexes that pair cobalt and copper were synthesized and characterized by a suite of physical methods, including X-ray diffraction, X-ray anomalous scattering, cyclic voltammetry, magnetometry, electronic absorption spectroscopy, electron paramagnetic resonance, and quantum chemical methods. Both Cu(II) and Cu(I) reagents were independently added to a Co(II) metalloligand to provide (py3tren)CoCuCl (1-Cl) and (py3tren)CoCu(CH3CN) (2-CH3CN), respectively, where py3tren is the triply deprotonated form of N,N,N-tris(2-(2-pyridylamino)ethyl)amine. Complex 2-CH3CN can lose the acetonitrile ligand to generate a coordination polymer consistent with the formula “(py3tren)CoCu” (2). One-electron chemical oxidation of 2-CH3CN with AgOTf generated (py3tren)CoCuOTf (1-OTf). The Cu(II)/Cu(I) redox couple for 1-OTf andmore » 2-CH3CN is reversible at -0.56 and -0.33 V vs Fc+/Fc, respectively. The copper oxidation state impacts the electronic structure of the heterobimetallic core, as well as the nature of the Co–Cu interaction. Quantum chemical calculations showed modest electron delocalization in the (CoCu)+4 state via a Co–Cu σ bond that is weakened by partial population of the Co–Cu σ antibonding orbital. By contrast, no covalent Co–Cu bonding is predicted for the (CoCu)+3 analogue, and the d-electrons are fully localized at individual metals.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eisenhart, Reed J.; Carlson, Rebecca K.; Clouston, Laura J.

Heterobimetallic complexes that pair cobalt and copper were synthesized and characterized by a suite of physical methods, including X-ray diffraction, X-ray anomalous scattering, cyclic voltammetry, magnetometry, electronic absorption spectroscopy, electron paramagnetic resonance, and quantum chemical methods. Both Cu(II) and Cu(I) reagents were independently added to a Co(II) metalloligand to provide (py 3tren)CoCuCl (1-Cl) and (py 3tren)CoCu(CH 3CN) (2-CH 3CN), respectively, where py3tren is the triply deprotonated form of N,N,N-tris(2-(2-pyridylamino)ethyl)amine. Complex 2-CH 3CN can lose the acetonitrile ligand to generate a coordination polymer consistent with the formula “(py3tren)CoCu” (2). One-electron chemical oxidation of 2-CH 3CN with AgOTf generated (py 3tren)CoCuOTf (1-OTf).more » The Cu(II)/Cu(I) redox couple for 1-OTf and 2-CH 3CN is reversible at -0.56 and -0.33 V vs Fc +/Fc, respectively. The copper oxidation state impacts the electronic structure of the heterobimetallic core, as well as the nature of the Co–Cu interaction. Quantum chemical calculations showed modest electron delocalization in the (CoCu) +4 state via a Co–Cu σ bond that is weakened by partial population of the Co–Cu σ antibonding orbital. By contrast, no covalent Co–Cu bonding is predicted for the (CoCu) +3 analogue, and the d-electrons are fully localized at individual metals.« less

Measuring Carbon Footprint of Flexible Pavement Construction Project in Indonesia

NASA Astrophysics Data System (ADS)

Hatmoko, Jati Utomo Dwi; Hidayat, Arif; Setiawati, Apsari; Prasetyo, Stefanus Catur Adi

2018-02-01

Road infrastructure in Indonesia is mainly dominated by flexible pavement type. Its construction process, however, has raised concerns in terms of its environment impacts. This study aims to track and measure the carbon footprint of flexible pavement. The objectives are to map the construction process in relation to greenhouse gas (GHG) emissions, to quantify them in terms of carbon dioxide equivalents (CO2e) as generated by the process of production and transportation of raw materials, and the operation of plant off-site and on-site project. Data collection was done by having site observations and interviews with project stakeholders. The results show a total emissions of 70.888 tonnes CO2e, consisting of 34.248 tonnes CO2e (48.31%) off-site activities and 36.640 tonnes CO2e (51.687%) on-site activities. The two highest CO2e emissions were generated by the use of plant for asphalt concrete laying activities accounted 34.827 tonnes CO2e (49.130%), and material transportation accounted 24.921 (35.155%). These findings provide a new perspective of the carbon footprint in flexible pavement and suggest the urgent need for the use of more efficient and environmentally friendly plant in construction process as it shows the most significant contribution on the CO2e. This study provides valuable understanding on the environmental impact of typical flexible pavement projects in Indonesia, and further can be used for developing green road framework.

Chemical synthesis of narrowly dispersed SmCo5 nanoparticles

NASA Astrophysics Data System (ADS)

Gu, Hongwei; Xu, Bing; Rao, Jiancun; Zheng, R. K.; Zhang, X. X.; Fung, K. K.; Wong, Catherine Y. C.

2003-05-01

In this article we report a chemical synthetic means for generating a high Ku magnetic material—narrowly dispersed nanoparticles of SmCo5. Using Co2(CO)8 and Sm(acac)3 as the precursors under air-free conditions, we produced SmCo5 nanoparticles according to the procedure reported by Sun et al. [Science 287, 1981 (2000)] but with some modifications. The nanoparticles, with diameters of 6-8 nm, have a SmCo5 composition, as indicated by transmission electron microscopy, electron diffraction, and x-ray photoelectron spectroscopy. The magnetization measurement of the nanoparticles, exhibits superparamagnetism, which is blocked for temperatures below ˜110 K, suggesting Ku to be ˜2.1×106 erg/cm3 for the as-prepared particles.

Production of MHD fluid

DOEpatents

Lacey, James J.; Kurtzrock, Roy C.; Bienstock, Daniel

1976-08-24

A hot gaseous fluid of low ash content, suitable for use in open-cycle MHD (magnetohydrodynamic) power generation, is produced by means of a three-stage process comprising (1) partial combustion of a fossil fuel to produce a hot gaseous product comprising CO.sub.2 CO, and H.sub.2 O, (2) reformation of the gaseous product from stage (1) by means of a fluidized char bed, whereby CO.sub.2 and H.sub.2 O are converted to CO and H.sub.2, and (3) combustion of CO and H.sub.2 from stage (2) to produce a low ash-content fluid (flue gas) comprising CO.sub.2 and H.sub.2 O and having a temperature of about 4000.degree. to 5000.degree.F.

Biogas production from anaerobic digestion of food waste and relevant air quality implications.

PubMed

Kuo, Jeff; Dow, Jason

2017-09-01

Biopower can diversify energy supply and improve energy resiliency. Increases in biopower production from sustainable biomass can provide many economic and environmental benefits. For example, increasing biogas production through anaerobic digestion of food waste would increase the use of renewable fuels throughout California and add to its renewables portfolio. Although a biopower project will produce renewable energy, the process of producing bioenergy should harmonize with the goal of protecting public health. Meeting air emission requirements is paramount to the successful implementation of any biopower project. A case study was conducted by collecting field data from a wastewater treatment plant that employs anaerobic codigestion of fats, oils, and grease (FOG), food waste, and wastewater sludge, and also uses an internal combustion (IC) engine to generate biopower using the biogas. This research project generated scientific information on (a) quality and quantity of biogas from anaerobic codigestion of food waste and municipal wastewater sludge, (b) levels of contaminants in raw biogas that may affect beneficial uses of the biogas, (c) removal of the contaminants by the biogas conditioning systems, (d) emissions of NO x , SO 2 , CO, CO 2 , and methane, and (e) types and levels of air toxics present in the exhausts of the IC engine fueled by the biogas. The information is valuable to those who consider similar operations (i.e., co-digestion of food waste with municipal wastewater sludge and power generation using the produced biogas) and to support rulemaking decisions with regards to air quality issues for such applications. Full-scale operation of anaerobic codigestion of food waste with municipal sludge is viable, but it is still new. There is a lack of readily available scientific information on the quality of raw biogas, as well as on potential emissions from power generation using this biogas. This research developed scientific information with regard to quality and quantity of biogas from anaerobic co-digestion of food waste and municipal wastewater sludge, as well as impacts on air quality from biopower generation using this biogas. The need and performance of conditioning/pretreatment systems for biopower generation were also assessed.

Direct observation of sequential oxidations of a titania-bound molecular proxy catalyst generated through illumination of molecular sensitizers

NASA Astrophysics Data System (ADS)

Chen, Hsiang-Yun; Ardo, Shane

2018-01-01

Natural photosynthesis uses the energy in sunlight to oxidize or reduce reaction centres multiple times, therefore preparing each reaction centre for a multiple-electron-transfer reaction that will ultimately generate stable reaction products. This process relies on multiple chromophores per reaction centre to quickly generate the active state of the reaction centre and to outcompete deleterious charge recombination. Using a similar design principle, we report spectroscopic evidence for the generation of a twice-oxidized TiO2-bound molecular proxy catalyst after low-intensity visible-light excitation of co-anchored molecular Ru(II)-polypyridyl dyes. Electron transfer from an excited dye to TiO2 generated a Ru(III) state that subsequently and repeatedly reacted with neighbouring Ru(II) dyes via self-exchange electron transfer to ultimately oxidize a distant co-anchored proxy catalyst before charge recombination. The largest yield for twice-oxidized proxy catalysts occurred when they were present at low coverage, suggesting that large dye/electrocatalyst ratios are also desired in dye-sensitized photoelectrochemical cells.

Competing for space in an already crowded market: a mixed methods study of why an online community of practice (CoP) for alcohol harm reduction failed to generate interest amongst the group of public health professionals at which it was aimed.

PubMed

Ponsford, Ruth; Ford, Jennifer; Korjonen, Helena; Hughes, Emma; Keswani, Asha; Pliakas, Triantafyllos; Egan, Matt

2017-07-21

Improving mechanisms for knowledge translation (KT) and connecting decision-makers to each other and the information and evidence they consider relevant to their work remains a priority for public health. Virtual communities of practices (CoPs) potentially offer an affordable and flexible means of encouraging connection and sharing of evidence, information and learning among the public health community in ways that transgress traditional geographical, professional, institutional and time boundaries. The suitability of online CoPs in public health, however, has rarely been tested. This paper explores the reasons why particular online CoP for alcohol harm reduction hosted by the UK Health Forum failed to generate sufficient interest from the group of public health professionals at which it was aimed. The study utilises online web-metrics demonstrating a lack of online activity on the CoP. One hundred and twenty seven responses to an online questionnaire were used to explore whether the lack of activity could be explained by the target audience's existing information and evidence practices and needs. Qualitative interviews with 10 members describe in more detail the factors that shape and inhibit use of the virtual CoP by those at which it was targeted. Quantitative and qualitative data confirm that the target audience had an interest in the kind of information and evidence the CoP was set up to share and generate discussion about, but also that participants considered themselves to already have relatively good access to the information and evidence they needed to inform their work. Qualitative data revealed that the main barriers to using the CoP were a proliferation of information sources meaning that participants preferred to utilise trusted sources that were already established within their daily routines and a lack of time to engage with new online tools that required any significant commitment. Specialist online CoPs are competing for space in an already crowded market. A target audience that regards itself as busy and over-supplied is unlikely to commit to a new service without the assurance that the service will provide unique and valuable well-summarised information, which would reduce the need to spend time accessing competing resources.

Habitat traits and food availability determine the response of marine invertebrates to ocean acidification.

PubMed

Pansch, Christian; Schaub, Iris; Havenhand, Jonathan; Wahl, Martin

2014-03-01

Energy availability and local adaptation are major components in mediating the effects of ocean acidification (OA) on marine species. In a long-term study, we investigated the effects of food availability and elevated pCO2 (ca. 400, 1000 and 3000 μatm) on growth of newly settled Amphibalanus (Balanus) improvisus to reproduction, and on their offspring. We also compared two different populations, which were presumed to differ in their sensitivity to pCO2 due to differing habitat conditions: Kiel Fjord, Germany (Western Baltic Sea) with naturally strong pCO2 fluctuations, and the Tjärnö Archipelago, Sweden (Skagerrak) with far lower fluctuations. Over 20 weeks, survival, growth, reproduction and shell strength of Kiel barnacles were all unaffected by elevated pCO2 , regardless of food availability. Moulting frequency and shell corrosion increased with increasing pCO2 in adults. Larval development and juvenile growth of the F1 generation were tolerant to increased pCO2 , irrespective of parental treatment. In contrast, elevated pCO2 had a strong negative impact on survival of Tjärnö barnacles. Specimens from this population were able to withstand moderate levels of elevated pCO2 over 5 weeks when food was plentiful but showed reduced growth under food limitation. Severe levels of elevated pCO2 negatively impacted growth of Tjärnö barnacles in both food treatments. We demonstrate a conspicuously higher tolerance to elevated pCO2 in Kiel barnacles than in Tjärnö barnacles. This tolerance was carried over from adults to their offspring. Our findings indicate that populations from fluctuating pCO2 environments are more tolerant to elevated pCO2 than populations from more stable pCO2 habitats. We furthermore provide evidence that energy availability can mediate the ability of barnacles to withstand moderate CO2 stress. Considering the high tolerance of Kiel specimens and the possibility to adapt over many generations, near future OA alone does not seem to present a major threat for A. improvisus. © 2013 John Wiley & Sons Ltd.

Carbon Management in the Electric Power Industry

NASA Astrophysics Data System (ADS)

Stringer, John

2002-03-01

Approximately 53States in 2000 came from the combustion of coal in Rankine cycle plant; 16principally in Brayton cycle or combined cycle units. Electricity generation is responsible for 36amthropogenic CO2. This compares with 32transportation sector, but since the electric utility generators are large fixed sources it is likely that any legislation designed to reduce CO2 production will adress the utility generators first. Over the last 100 years there has been a continuous decrease in the carbon fraction of the fuels used for energy production world wide, and it is expected that this will continue, principally as a result of the increasing fraction of natural gas. It appears probable that the retirement of the existing nuclear fleet will be delayed by relicensing, and it seems more possible that new nuclear plant will be built than seemed likely even a couple of years ago. The impact of renewables should be increasing, but currently only about 2way currently, and without some considerable incentives, the rate of increase in this component over the next twenty years will probably be small. Currently, hydroelectric plants account for 7indication that this will increase appreciably. At the moment, a significant change would appear to require the capture of CO2 from the exhaust of the combustion plants, and particularly the large existing fleet of coal-fired Rankine units. Following the capture, the CO2 must then be sequestered in secure long-term locations. In addition, increases in the efficiency of power generation, and increases in the efficiency of end use leading to reductions in the energy intensity of the Gross Domestic Product, will be necessary. This paper will review the current state of art in these various approaches to the problem.

Vortex Generators in a Streamline-Traced, External-Compression Supersonic Inlet

NASA Technical Reports Server (NTRS)

Baydar, Ezgihan; Lu, Frank K.; Slater, John W.; Trefny, Charles J.

2017-01-01

Vortex generators within a streamline-traced, external-compression supersonic inlet for Mach 1.66 were investigated to determine their ability to increase total pressure recovery and reduce total pressure distortion. The vortex generators studied were rectangular vanes arranged in counter-rotating and co-rotating arrays. The vane geometric factors of interest included height, length, spacing, angle-of-incidence, and positions upstream and downstream of the inlet terminal shock. The flow through the inlet was simulated numerically through the solution of the steady-state, Reynolds-averaged Navier-Stokes equations on multi-block, structured grids using the Wind-US flow solver. The vanes were simulated using a vortex generator model. The inlet performance was characterized by the inlet total pressure recovery and the radial and circumferential total pressure distortion indices at the engine face. Design of experiments and statistical analysis methods were applied to quantify the effect of the geometric factors of the vanes and search for optimal vane arrays. Co-rotating vane arrays with negative angles-of-incidence positioned on the supersonic diffuser were effective in sweeping low-momentum flow from the top toward the sides of the subsonic diffuser. This distributed the low-momentum flow more evenly about the circumference of the subsonic diffuser and reduced distortion. Co-rotating vane arrays with negative angles-of-incidence or counter-rotating vane arrays positioned downstream of the terminal shock were effective in mixing higher-momentum flow with lower-momentum flow to increase recovery and decrease distortion. A strategy of combining a co-rotating vane array on the supersonic diffuser with a counter-rotating vane array on the subsonic diffuser was effective in increasing recovery and reducing distortion.

CaCO3 Precipitation in Multilayered Cyanobacterial Mats: Clues to Explain the Alternation of Micrite and Sparite Layers in Calcareous Stromatolites

PubMed Central

Kaźmierczak, Józef; Fenchel, Tom; Kühl, Michael; Kempe, Stephan; Kremer, Barbara; Łącka, Bożena; Małkowski, Krzysztof

2015-01-01

Marine cyanobacterial mats were cultured on coastal sediments (Nivå Bay, Øresund, Denmark) for over three years in a closed system. Carbonate particles formed in two different modes in the mat: (i) through precipitation of submicrometer-sized grains of Mg calcite within the mucilage near the base of living cyanobacterial layers, and (ii) through precipitation of a variety of mixed Mg calcite/aragonite morphs in layers of degraded cyanobacteria dominated by purple sulfur bacteria. The δ13C values were about 2‰ heavier in carbonates from the living cyanobacterial zones as compared to those generated in the purple bacterial zones. Saturation indices calculated with respect to calcite, aragonite, and dolomite inside the mats showed extremely high values across the mat profile. Such high values were caused by high pH and high carbonate alkalinity generated within the mats in conjunction with increased concentrations of calcium and magnesium that were presumably stored in sheaths and extracellular polymer substances (EPS) of the living cyanobacteria and liberated during their post-mortem degradation. The generated CaCO3 morphs were highly similar to morphs reported from heterotrophic bacterial cultures, and from bacterially decomposed cyanobacterial biomass emplaced in Ca-rich media. They are also similar to CaCO3 morphs precipitated from purely inorganic solutions. No metabolically (enzymatically) controlled formation of particular CaCO3 morphs by heterotrophic bacteria was observed in the studied mats. The apparent alternation of in vivo and post-mortem generated calcareous layers in the studied cyanobacterial mats may explain the alternation of fine-grained (micritic) and coarse-grained (sparitic) laminae observed in modern and fossil calcareous cyanobacterial microbialites as the result of a probably similar multilayered mat organization. PMID:25761263

The oxycoal process with cryogenic oxygen supply.

PubMed

Kather, Alfons; Scheffknecht, Günter

2009-09-01

Due to its large reserves, coal is expected to continue to play an important role in the future. However, specific and absolute CO2 emissions are among the highest when burning coal for power generation. Therefore, the capture of CO2 from power plants may contribute significantly in reducing global CO2 emissions. This review deals with the oxyfuel process, where pure oxygen is used for burning coal, resulting in a flue gas with high CO2 concentrations. After further conditioning, the highly concentrated CO2 is compressed and transported in the liquid state to, for example, geological storages. The enormous oxygen demand is generated in an air-separation unit by a cryogenic process, which is the only available state-of-the-art technology. The generation of oxygen and the purification and liquefaction of the CO2-enriched flue gas consumes significant auxiliary power. Therefore, the overall net efficiency is expected to be lowered by 8 to 12 percentage points, corresponding to a 21 to 36% increase in fuel consumption. Oxygen combustion is associated with higher temperatures compared with conventional air combustion. Both the fuel properties as well as limitations of steam and metal temperatures of the various heat exchanger sections of the steam generator require a moderation of the temperatures during combustion and in the subsequent heat-transfer sections. This is done by means of flue gas recirculation. The interdependencies among fuel properties, the amount and the temperature of the recycled flue gas, and the resulting oxygen concentration in the combustion atmosphere are investigated. Expected effects of the modified flue gas composition in comparison with the air-fired case are studied theoretically and experimentally. The different atmosphere resulting from oxygen-fired combustion gives rise to various questions related to firing, in particular, with regard to the combustion mechanism, pollutant reduction, the risk of corrosion, and the properties of the fly ash or the deposits that form. In particular, detailed nitrogen and sulphur chemistry was investigated by combustion tests in a laboratory-scale facility. Oxidant staging, in order to reduce NO formation, turned out to work with similar effectiveness as for conventional air combustion. With regard to sulphur, a considerable increase in the SO2 concentration was found, as expected. However, the H2S concentration in the combustion atmosphere increased as well. Further results were achieved with a pilot-scale test facility, where acid dew points were measured and deposition probes were exposed to the combustion environment. Besides CO2 and water vapour, the flue gas contains impurities like sulphur species, nitrogen oxides, argon, nitrogen, and oxygen. The CO2 liquefaction is strongly affected by these impurities in terms of the auxiliary power requirement and the CO2 capture rate. Furthermore, the impurity of the liquefied CO2 is affected as well. Since the requirements on the liquid CO2 with regard to geological storage or enhanced oil recovery are currently undefined, the effects of possible flue gas treatment and the design of the liquefaction plant are studied over a wide range.

The oxycoal process with cryogenic oxygen supply

NASA Astrophysics Data System (ADS)

Kather, Alfons; Scheffknecht, Günter

2009-09-01

Due to its large reserves, coal is expected to continue to play an important role in the future. However, specific and absolute CO2 emissions are among the highest when burning coal for power generation. Therefore, the capture of CO2 from power plants may contribute significantly in reducing global CO2 emissions. This review deals with the oxyfuel process, where pure oxygen is used for burning coal, resulting in a flue gas with high CO2 concentrations. After further conditioning, the highly concentrated CO2 is compressed and transported in the liquid state to, for example, geological storages. The enormous oxygen demand is generated in an air-separation unit by a cryogenic process, which is the only available state-of-the-art technology. The generation of oxygen and the purification and liquefaction of the CO2-enriched flue gas consumes significant auxiliary power. Therefore, the overall net efficiency is expected to be lowered by 8 to 12 percentage points, corresponding to a 21 to 36% increase in fuel consumption. Oxygen combustion is associated with higher temperatures compared with conventional air combustion. Both the fuel properties as well as limitations of steam and metal temperatures of the various heat exchanger sections of the steam generator require a moderation of the temperatures during combustion and in the subsequent heat-transfer sections. This is done by means of flue gas recirculation. The interdependencies among fuel properties, the amount and the temperature of the recycled flue gas, and the resulting oxygen concentration in the combustion atmosphere are investigated. Expected effects of the modified flue gas composition in comparison with the air-fired case are studied theoretically and experimentally. The different atmosphere resulting from oxygen-fired combustion gives rise to various questions related to firing, in particular, with regard to the combustion mechanism, pollutant reduction, the risk of corrosion, and the properties of the fly ash or the deposits that form. In particular, detailed nitrogen and sulphur chemistry was investigated by combustion tests in a laboratory-scale facility. Oxidant staging, in order to reduce NO formation, turned out to work with similar effectiveness as for conventional air combustion. With regard to sulphur, a considerable increase in the SO2 concentration was found, as expected. However, the H2S concentration in the combustion atmosphere increased as well. Further results were achieved with a pilot-scale test facility, where acid dew points were measured and deposition probes were exposed to the combustion environment. Besides CO2 and water vapour, the flue gas contains impurities like sulphur species, nitrogen oxides, argon, nitrogen, and oxygen. The CO2 liquefaction is strongly affected by these impurities in terms of the auxiliary power requirement and the CO2 capture rate. Furthermore, the impurity of the liquefied CO2 is affected as well. Since the requirements on the liquid CO2 with regard to geological storage or enhanced oil recovery are currently undefined, the effects of possible flue gas treatment and the design of the liquefaction plant are studied over a wide range.

Vapochromic Behaviour of M[Au(CN)2]2-Based Coordination Polymers (M = Co, Ni)

PubMed Central

Lefebvre, Julie; Korčok, Jasmine L.; Katz, Michael J.; Leznoff, Daniel B.

2012-01-01

A series of M[Au(CN)2]2(analyte)x coordination polymers (M = Co, Ni; analyte = dimethylsulfoxide (DMSO), N,N-dimethylformamide (DMF), pyridine; x = 2 or 4) was prepared and characterized. Addition of analyte vapours to solid M(μ-OH2)[Au(CN)2]2 yielded visible vapochromic responses for M = Co but not M = Ni; the IR νCN spectral region changed in every case. A single crystal structure of Zn[Au(CN)2]2(DMSO)2 revealed a corrugated 2-D layer structure with cis-DMSO units. Reacting a Ni(II) salt and K[Au(CN)2] in DMSO yielded the isostructural Ni[Au(CN)2]2(DMSO)2 product. Co[Au(CN)2]2(DMSO)2 and M[Au(CN)2]2(DMF)2 (M = Co, Ni) complexes have flat 2-D square-grid layer structures with trans-bound DMSO or DMF units; they are formed via vapour absorption by solid M(μ-OH2)[Au(CN)2]2 and from DMSO or DMF solution synthesis. Co[Au(CN)2]2(pyridine)4 is generated via vapour absorption by Co(μ-OH2)[Au(CN)2]2; the analogous Ni complex is synthesized by immersion of Ni(μ-OH2)[Au(CN)2]2 in 4% aqueous pyridine. Similar immersion of Co(μ-OH2)[Au(CN)2]2 yielded Co[Au(CN)2]2(pyridine)2, which has a flat 2-D square-grid structure with trans-pyridine units. Absorption of pyridine vapour by solid Ni(μ-OH2)[Au(CN)2]2 was incomplete, generating a mixture of pyridine-bound complexes. Analyte-free Co[Au(CN)2]2 was prepared by dehydration of Co(μ-OH2)[Au(CN)2]2 at 145 °C; it has a 3-D diamondoid-type structure and absorbs DMSO, DMF and pyridine to give the same materials as by vapour absorption from the hydrate. PMID:22737031

Enhanced thermal destruction of toxic microalgal biomass by using CO2.

PubMed

Jung, Jong-Min; Lee, Jechan; Kim, Jieun; Kim, Ki-Hyun; Kim, Hyung-Wook; Jeon, Young Jae; Kwon, Eilhann E

2016-10-01

This work confirmed that dominant microalgal strain in the eutrophic site (the Han River in Korea) was Microcystis aeruginosa (M. aeruginosa) secreting toxins. Collected and dried microalgal biomass had an offensive odor due to microalgal lipid, of which the content reached up to 2±0.2wt.% of microalgal biomass (dry basis). This study has validated that the offensive odor is attributed to the C3-6 range of volatile fatty acids (VFAs), which was experimentally identified by the non-catalytic transformation of triglycerides (TGs) and free fatty acids (FFAs) in microalgal biomass into fatty acid methyl esters (FAMEs). In particular, this study mechanistically investigated the influence of CO2 in the thermal destruction (i.e., pyrolysis) of hazardous microalgal biomass in order to achieve dual purposes (i.e., thermal disposal of hazardous microalgal biomass and energy recovery). The influence of CO2 in pyrolysis of microalgal biomass was identified as 1) the enhanced thermal cracking behaviors of volatile organic compounds (VOCs) from the thermal degradation of microalgal biomass and 2) the direct gas phase reaction between CO2 and VOCs. These identified influences of CO2 in pyrolysis of microalgal biomass significantly enhanced the generation of CO: the enhanced generation of CO in the presence of CO2 was 590% at 660°C, 1260% at 690°C, and 3200% at 720°C. In addition, two identified influences of CO2 (i.e., enhanced thermal cracking and direct gas phase reaction) occurred simultaneously and independently. The identified gas phase reaction in the presence of CO2 was only initiated at temperatures higher than 500°C, which was different from the Boudouard reaction. Lastly, the experimental work justified that exploiting CO2 as a reaction medium and/or chemical feedstock will provide new technical approaches for controlling syngas ratio and in-situ air pollutant control without using catalysts. Copyright © 2016 Elsevier B.V. All rights reserved.

How much CO2 is trapped in carbonate minerals of a natural CO2 occurrence?

NASA Astrophysics Data System (ADS)

Király, Csilla; Szabó, Zsuzsanna; Szamosfalvi, Ágnes; Cseresznyés, Dóra; Király, Edit; Szabó, Csaba; Falus, György

2017-04-01

Carbon Capture and Storage (CCS) is a transitional technology to decrease CO2 emissions from human fossil fuel usage and, therefore, to mitigate climate change. The most important criteria of a CO2 geological storage reservoir is that it must hold the injected CO2 for geological time scales without its significant seepage. The injected CO2 undergoes physical and chemical reactions in the reservoir rocks such as structural-stratigraphic, residual, dissolution or mineral trapping mechanisms. Among these, the safest is the mineral trapping, when carbonate minerals such as calcite, ankerite, siderite, dolomite and dawsonite build the CO2 into their crystal structures. The study of natural CO2 occurrences may help to understand the processes in CO2 reservoirs on geological time scales. This is the reason why the selected, the Mihályi-Répcelak natural CO2 occurrence as our research area, which is able to provide particular and highly significant information for the future of CO2 storage. The area is one of the best known CO2 fields in Central Europe. The main aim of this study is to estimate the amount of CO2 trapped in the mineral phase at Mihályi-Répcelak CO2 reservoirs. For gaining the suitable data, we apply petrographic, major and trace element (microprobe and LA-ICP-MS) and stable isotope analysis (mass spectrometry) and thermodynamic and kinetic geochemical models coded in PHREEQC. Rock and pore water compositions of the same formation, representing the pre-CO2 flooding stages of the Mihályi-Répcelak natural CO2 reservoirs are used in the models. Kinetic rate parameters are derived from the USGS report of Palandri and Kharaka (2004). The results of petrographic analysis show that a significant amount of dawsonite (NaAlCO3(OH)2, max. 16 m/m%) precipitated in the rock due to its reactions with CO2 which flooded the reservoir. This carbonate mineral alone traps about 10-30 kg/m3 of the reservoir rock from the CO2 at Mihályi-Répcelak area, which is an unexpectedly high proportion of total amount of CO2. Further results enlightened that other carbonates, ankerite, calcite and siderite have precipitated in two generations, the first before and the second after the CO2 flooding. Further laboratory analysis and geochemical models allow us to estimate the ratio of these two generations and also to understand how far the reservoir rock is in the CO2 mineral trapping process.

Feasibility study of algae-based Carbon Dioxide capture ...

EPA Pesticide Factsheets

SUMMARY: The biomass of microalgae contains approximately 50% carbon, which is commonly obtained from the atmosphere, but can also be taken from commercial sources that produce CO2, such as coal-fired power plants. A study of operational demonstration projects is being undertaken to evaluate the benefits of using algae to reduce CO2 emissions from industrial and small-scale utility power boilers. The operations are being studied for the use of CO2 from flue gas for algae growth along with the production of biofuels and other useful products to prepare a comprehensive characterization of the economic feasibility of using algae to capture CO2. Information is being generated for analyses of the potential for these technologies to advance in the market and assist in meeting environmental goals, as well as to examine their associated environmental implications. Three electric power generation plants (coal and fuel oil fired) equipped to send flue-gas emissions to algae culture at demonstration facilities are being studied. Data and process information are being collected and developed to facilitate feasibility and modeling evaluations of the CO2 to algae technology. An understanding of process requirements to apply this technology to existing industries would go far in advancing carbon capture opportunities. Documenting the successful use of this technology could help bring “low-tech”, low-cost, CO2 to algae, carbon capture to multiple size industries and

Molecular description of α-keto-based inhibitors of cruzain with activity against Chagas disease combining 3D-QSAR studies and molecular dynamics.

PubMed

Saraiva, Ádria P B; Miranda, Ricardo M; Valente, Renan P P; Araújo, Jéssica O; Souza, Rutelene N B; Costa, Clauber H S; Oliveira, Amanda R S; Almeida, Michell O; Figueiredo, Antonio F; Ferreira, João E V; Alves, Cláudio Nahum; Honorio, Kathia M

2018-04-22

In this work, a group of α-keto-based inhibitors of the cruzain enzyme with anti-chagas activity was selected for a three-dimensional quantitative structure-activity relationship study (3D-QSAR) combined with molecular dynamics (MD). Firstly, statistical models based on Partial Least Square (PLS) regression were developed employing comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) descriptors. Validation parameters (q 2 and r 2 )for the models were, respectively, 0.910 and 0.997 (CoMFA) and 0.913 and 0.992 (CoMSIA). In addition, external validation for the models using a test group revealed r 2 pred  = 0.728 (CoMFA) and 0.971 (CoMSIA). The most relevant aspect in this study was the generation of molecular fields in both favorable and unfavorable regions based on the models developed. These fields are important to interpret modifications necessary to enhance the biological activities of the inhibitors. This analysis was restricted considering the inhibitors in a fixed conformation, not interacting with their target, the cruzain enzyme. Then, MD was employed taking into account important variables such as time and temperature. MD helped describe the behavior of the inhibitors and their properties showed similar results as those generated by QSAR-3D study. © 2018 John Wiley & Sons A/S.

CO2 bubble generation and migration during magma-carbonate interaction

NASA Astrophysics Data System (ADS)

Blythe, L. S.; Deegan, F. M.; Freda, C.; Jolis, E. M.; Masotta, M.; Misiti, V.; Taddeucci, J.; Troll, V. R.

2015-04-01

We conducted quantitative textural analysis of vesicles in high temperature and pressure carbonate assimilation experiments (1200 °C, 0.5 GPa) to investigate CO2 generation and subsequent bubble migration from carbonate into magma. We employed Mt. Merapi (Indonesia) and Mt. Vesuvius (Italy) compositions as magmatic starting materials and present three experimental series using (1) a dry basaltic-andesite, (2) a hydrous basaltic-andesite (2 wt% H2O), and (3) a hydrous shoshonite (2 wt% H2O). The duration of the experiments was varied from 0 to 300 s, and carbonate assimilation produced a CO2-rich fluid and CaO-enriched melts in all cases. The rate of carbonate assimilation, however, changed as a function of melt viscosity, which affected the 2D vesicle number, vesicle volume, and vesicle size distribution within each experiment. Relatively low-viscosity melts (i.e. Vesuvius experiments) facilitated efficient removal of bubbles from the reaction site. This allowed carbonate assimilation to continue unhindered and large volumes of CO2 to be liberated, a scenario thought to fuel sustained CO2-driven eruptions at the surface. Conversely, at higher viscosity (i.e. Merapi experiments), bubble migration became progressively inhibited and bubble concentration at the reaction site caused localised volatile over-pressure that can eventually trigger short-lived explosive outbursts. Melt viscosity therefore exerts a fundamental control on carbonate assimilation rates and, by consequence, the style of CO2-fuelled eruptions.

Gadolinia-Doped Ceria Cathodes for Electrolysis of CO2

NASA Technical Reports Server (NTRS)

Adler, Stuart B.

2009-01-01

Gadolinia-doped ceria, or GDC, (Gd(0.4)Ce(0.6)O(2-delta), where the value of delta in this material varies, depending on the temperature and oxygen concentration in the atmosphere in which it is being used) has shown promise as a cathode material for high-temperature electrolysis of carbon dioxide in solid oxide electrolysis cells. The polarization resistance of a GDC electrode is significantly less than that of an otherwise equivalent electrode made of any of several other materials that are now in use or under consideration for use as cathodes for reduction of carbon dioxide. In addition, GDC shows no sign of deterioration under typical temperature and gas-mixture operating conditions of a high-temperature electrolyzer. Electrolysis of CO2 is of interest to NASA as a way of generating O2 from the CO2 in the Martian atmosphere. On Earth, a combination of electrolysis of CO2 and electrolysis of H2O might prove useful as a means of generating synthesis gas (syngas) from the exhaust gas of a coal- or natural-gas-fired power plant, thereby reducing the emission of CO2 into the atmosphere. The syngas a mixture of CO and H2 could be used as a raw material in the manufacture, via the Fisher-Tropsch process, of synthetic fuels, lubrication oils, and other hydrocarbon prod

Human breast cancer histoid: an in vitro 3-dimensional co-culture model that mimics breast cancer tissue.

PubMed

Kaur, Pavinder; Ward, Brenda; Saha, Baisakhi; Young, Lillian; Groshen, Susan; Techy, Geza; Lu, Yani; Atkinson, Roscoe; Taylor, Clive R; Ingram, Marylou; Imam, S Ashraf

2011-12-01

Progress in our understanding of heterotypic cellular interaction in the tumor microenvironment, which is recognized to play major roles in cancer progression, has been hampered due to unavailability of an appropriate in vitro co-culture model. The aim of this study was to generate an in vitro 3-dimensional human breast cancer model, which consists of cancer cells and fibroblasts. Breast cancer cells (UACC-893) and fibroblasts at various densities were co-cultured in a rotating suspension culture system to establish co-culture parameters. Subsequently, UACC-893, BT.20, or MDA.MB.453 were co-cultured with fibroblasts for 9 days. Co-cultures resulted in the generation of breast cancer histoid (BCH) with cancer cells showing the invasion of fibroblast spheroids, which were visualized by immunohistochemical (IHC) staining of sections (4 µm thick) of BCH. A reproducible quantitative expression of C-erbB.2 was detected in UACC-893 cancer cells in BCH sections by IHC staining and the Automated Cellular Imaging System. BCH sections also consistently exhibited qualitative expression of pancytokeratins, p53, Ki-67, or E-cadherin in cancer cells and that of vimentin or GSTPi in fibroblasts, fibronectin in the basement membrane and collagen IV in the extracellular matrix. The expression of the protein analytes and cellular architecture of BCH were markedly similar to those of breast cancer tissue.

Recent progress in [11 C]carbon dioxide ([11 C]CO2 ) and [11 C]carbon monoxide ([11 C]CO) chemistry.

PubMed

Taddei, Carlotta; Gee, Antony D

2018-03-01

[ 11 C]Carbon dioxide ([ 11 C]CO 2 ) and [ 11 C]carbon monoxide ([ 11 C]CO) are 2 attractive precursors for labelling the carbonyl position (C═O) in a vast range of functionalised molecules (eg, ureas, amides, and carboxylic acids). The development of radiosynthetic methods to produce functionalised 11 C-labelled compounds is required to enhance the radiotracers available for positron emission tomography, molecular, and medical imaging applications. Following a brief summary of secondary 11 C-precursor production and uses, the review focuses on recent progress with direct 11 C-carboxylation routes with [ 11 C]CO 2 and 11 C-carbonylation with [ 11 C]CO. Novel approaches to generate [ 11 C]CO using CO-releasing molecules (CO-RMs), such as silacarboxylic acids and disilanes, applied to radiochemistry are described and compared with standard [ 11 C]CO production methods. These innovative [ 11 C]CO synthesis strategies represent efficient and reliable [ 11 C]CO production processes, enabling the widespread use of [ 11 C]CO chemistry within the wider radiochemistry community. Copyright © 2017 John Wiley & Sons, Ltd.