Effects of Hydration and Oxygen Vacancy on CO2 Adsorption and Activation on β-Ga2O3(100)

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

Pan, Yunxiang; Liu, Chang-jun; Mei, Donghai

The effects of hydration and oxygen vacancy on CO2 adsorption on the β-Ga2O3(100) surface have been studied using density functional theory slab calculations. Adsorbed CO2 is activated on the dry perfect β-Ga2O3(100) surface, resulting in a carbonate species. This adsorption is slightly endothermic, with an adsorption energy of 0.07 eV. Water is preferably adsorbed molecularly on the dry perfect β-Ga2O3(100) surface with an adsorption energy of -0.56 eV, producing a hydrated perfect β-Ga2O3(100) surface. Adsorption of CO2 on the hydrated surface as a carbonate species is also endothermic, with an adsorption energy of 0.14 eV, indicating a slight repulsive interactionmore » when H2O and CO2 are coadsorbed. The carbonate species on the hydrated perfect surface can be protonated by the co-adsorbed H2O to a bicarbonate species, making the overall process exothermic with an adsorption energy of -0.13 eV. The effect of defects on CO2 adsorption and activation has been examined by creating an oxygen vacancy on the dry β-Ga2O3(100) surface. The formation of an oxygen vacancy is endothermic, by 0.34 eV, with respect to a free O2 molecule in the gas phase. Presence of the oxygen vacancy promoted the adsorption and activation of CO2. In the most stable CO2 adsorption configuration on the dry defective β-Ga2O3(100) surface with an oxygen vacancy, one of the oxygen atoms of the adsorbed CO2 occupies the oxygen vacancy site and the CO2 adsorption energy is -0.31 eV. Water favors dissociative adsorption at the oxygen vacancy site on the defective surface. This process is instantaneous with an adsorption energy of -0.62 eV. These results indicate that, when water and CO2 are both present in the adsorption system simultaneously, the water molecule will compete with CO2 for the oxygen vacancy sites and impact CO2 adsorption and conversion negatively. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy. A portion of the computing time was granted by the scientific user projects using the Molecular Science Computing Facility in the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL). The EMSL is a DOE national scientific user facility located at PNNL, and supported by the DOE’s Office of Science, Biological and Environmental Research.« less

Workplace Charging Behavior of Nissan Leafs in The EV Project at Six Work Sites

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

Rohrbaugh, David; Smart, John

2014-11-01

This paper documents findings from analysis of data collected from Nissan Leafs enrolled in The EV Project who parked and charged at six workplaces with EV charging equipment. It will be published as a white paper on INL's website, accessible by the general public.

[Correlation between thermostability of the xylanase EvXyn11(TS) and its N-terminal disulfide bridge].

PubMed

Min, Rou; Li, Jianfang; Gao, Shujuan; Zhang, Huimin; Wu, Jing; Wu, Minchen

2013-04-04

To reveal the correlation between thermostability of xylanase EvXyn11(TS) and its N-terminal disulfide bridge, an EvXyn11(TS)-encoding gene (Syxyn11) was synthesized and subjected to site-directed mutagenesis. Multiple homology alignment of protein primary structures between the EvXyn11(TS) and several GH family 11 xylanases displayed that, in their N-termini, only EvXyn11(TS) contained a disulfide bridge (Cys5-Cys32), whose effect on the xylanase thermostability was predicted by molecular dynamics simulation. We constructed a gene Syxyn11(M), encoding the mutated xylanase (EvXyn11(M)) without N-terminal disulfide bridge. Then, Syxyn11 and Syxyn11(M) were expressed in Pichia pastoris GS115, and temperature and pH properties of the expressed enzymes were analyzed. The analytical results displayed that the temperature optimum of EvXyn11(M) was 70 degrees C, which was 15 degrees C lower than that of EvXyn11(TS). The half-life (t1/2(90)) of EvXyn11(TS) at 90 degrees C was 32 min, while the t1/2(70) of EvXyn11(M) at 70 degrees C was only 8.0 min. The important role of the N-terminal disulfide bridge on the thermostability of EvXyn11(TS) was first predicted by molecular dynamics simulation, and confirmed by site-directed mutagenesis. This work provided a novel strategy to improve thermostabilities of the mesophilic family 11 xylanases with high specific activities.

Fast Charging Electric Vehicle Research & Development Project

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

Heny, Michael

The research and development project supported the engineering, design and implementation of on-road Electric Vehicle (“EV”) charging technologies. It included development of potential solutions for DC fast chargers (“DCFC”) capable of converting high voltage AC power to the DC power required by EVs. Additional development evaluated solutions related to the packaging of power electronic components and enclosure design, as well as for the design and evaluation of EV charging stations. Research compared different charging technologies to identify optimum applications in a municipal fleet. This project collected EV usage data and generated a report demonstrating that EVs, when supported by adequatemore » charging infrastructure, are capable of replacing traditional internal combustion vehicles in many municipal applications. The project’s period of performance has demonstrated various methods of incorporating EVs into a municipal environment, and has identified three general categories for EV applications: Short Commute: Defined as EVs performing in limited duration, routine commutes. - Long Commute: Defined as tasks that require EVs to operate in longer daily mileage patterns. - Critical Needs: Defined as the need for EVs to be ready at every moment for indefinite periods. Together, the City of Charlottesville, VA (the “City”) and Aker Wade Power Technologies, LLC (“Aker Wade”) concluded that the EV has a viable position in many municipal fleets but with limited recommendation for use in Critical Needs applications such as Police fleets. The report also documented that, compared to internal combustion vehicles, BEVs have lower vehicle-related greenhouse gas (“GHG”) emissions and contribute to a reduction of air pollution in urban areas. The enhanced integration of EVs in a municipal fleet can result in reduced demand for imported oil and reduced municipal operating costs. The conclusions indicated in the project’s Engineering Report (see Attachment A) are intended to assist future implementation of electric vehicle technology. They are based on the cited research and on the empirical data collected and presented. The report is not expected to represent the entire operating conditions of any of the equipment under consideration within this project, and tested equipment may operate differently under other conditions.« less

The impact of electric vehicles on the Southern California Edison System. Final report

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

Ford, A.

1992-07-01

This report describes the results of the first phase of an investigation of the impacts of electric vehicles (EVs) in southern California. The investigation focuses on the Southern California Edison Company (SCE) which provides electric service for approximately 60% of southern California. The project is supported by the ``Air Quality Impacts of Energy Efficiency`` Program of the California Institute for Energy Efficiency (CIEE). The first phase of the research is organized around how EVs might be viewed by customers, vehicle manufacturers and electric utility companies. The vehicle manufacturers` view has been studied with special emphasis on the role of marketablemore » permit systems. The utilities` view of EVs is the subject of this report. The review is particularly important as several case studies of EVs in southern California have been conducted in recent years. The dynamics of a growing population of EVs is explained. Chapter 5 explains a simple method of deriving the electricity demands which could result from the operation of EVs in southern California. The method is demonstrated for several simple examples and then used to find the demands associated with each of the eight EV scenarios. Chapter 6 reports the impacts on SCE operations from the new demands for electricity. Impacts are summarized in terms of system operating costs, reliability of service, and changes in the utility`s average electric rate. Chapter 7 turns to the emissions of air pollutants released by the operation of EVs, conventional vehicles (CVs) and power plants. Chapter 8 takes the air pollution analysis one step further by examining the possible reduction in ambient ozone concentration in southern California.« less

The impact of electric vehicles on the Southern California Edison System

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

Ford, A.

1992-07-01

This report describes the results of the first phase of an investigation of the impacts of electric vehicles (EVs) in southern California. The investigation focuses on the Southern California Edison Company (SCE) which provides electric service for approximately 60% of southern California. The project is supported by the Air Quality Impacts of Energy Efficiency'' Program of the California Institute for Energy Efficiency (CIEE). The first phase of the research is organized around how EVs might be viewed by customers, vehicle manufacturers and electric utility companies. The vehicle manufacturers' view has been studied with special emphasis on the role of marketablemore » permit systems. The utilities' view of EVs is the subject of this report. The review is particularly important as several case studies of EVs in southern California have been conducted in recent years. The dynamics of a growing population of EVs is explained. Chapter 5 explains a simple method of deriving the electricity demands which could result from the operation of EVs in southern California. The method is demonstrated for several simple examples and then used to find the demands associated with each of the eight EV scenarios. Chapter 6 reports the impacts on SCE operations from the new demands for electricity. Impacts are summarized in terms of system operating costs, reliability of service, and changes in the utility's average electric rate. Chapter 7 turns to the emissions of air pollutants released by the operation of EVs, conventional vehicles (CVs) and power plants. Chapter 8 takes the air pollution analysis one step further by examining the possible reduction in ambient ozone concentration in southern California.« less

Medium-Duty Plug-in Electric Delivery Truck Fleet Evaluation

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

Prohaska, Robert; Ragatz, Adam; Simpson, Mike

2016-06-29

In this paper, the authors present an overview of medium-duty electric vehicle (EV) operating behavior based on in-use data collected from Smith Newton electric delivery vehicles and compare their performance and operation to conventional diesel trucks operating in the same fleet. The vehicles' drive cycles and operation are analyzed and compared to demonstrate the importance of matching specific EV technologies to the appropriate operational duty cycle. The results of this analysis show that the Smith Newton EVs demonstrated a 68% reduction in energy consumption over the data reporting period compared to the conventional diesel vehicles, as well as a 46.4%more » reduction in carbon dioxide equivalent emissions based on the local energy generation source.« less

Medium-duty plug-in electric delivery truck fleet evaluation

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

Prohaska, Robert; Ragatz, Adam; Simpson, Mike

2016-06-01

In this paper, the authors present an overview of medium-duty electric vehicle (EV) operating behavior based on in-use data collected from Smith Newton electric delivery vehicles and compare their performance and operation to conventional diesel trucks operating in the same fleet. The vehicles' drive cycles and operation are analyzed and compared to demonstrate the importance of matching specific EV technologies to the appropriate operational duty cycle. The results of this analysis show that the Smith Newton EVs demonstrated a 68% reduction in energy consumption over the data reporting period compared to the conventional diesel vehicles, as well as a 46.4%more » reduction in carbon dioxide equivalent emissions based on the local energy generation source.« less

Medium-Duty Plug-In Electric Delivery Truck Fleet Evaluation: Preprint

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

Prohaska, Robert; Ragatz, Adam; Simpson, Mike

2016-04-13

In this paper, the authors present an overview of medium-duty electric vehicle (EV) operating behavior based on in-use data collected from Smith Newton electric delivery vehicles and compare their performance and operation to conventional diesel trucks operating in the same fleet. The vehicles' drive cycles and operation are analyzed and compared to demonstrate the importance of matching specific EV technologies to the appropriate operational duty cycle. The results of this analysis show that the Smith Newton EVs demonstrated a 68% reduction in energy consumption over the data reporting period compared to the conventional diesel vehicles, as well as a 46.4%more » reduction in carbon dioxide equivalent emissions based on the local energy generation source.« less

NREL Charges Forward to Reduce Time at EV Stations | News | NREL

Science.gov Websites

station siting, travel patterns, grid resources, and business cases. At the same time, it is clear that Charges Forward to Reduce Time at EV Stations NREL Charges Forward to Reduce Time at EV Stations charging stations in Europe that will begin to approach the refueling time of gasoline vehicles. Photo

The Effects of Synthetic and Enhanced Vision Technologies for Lunar Landings

NASA Technical Reports Server (NTRS)

Kramer, Lynda J.; Norman, Robert M.; Prinzel, Lawrence J., III; Bailey, Randall E.; Arthur, Jarvis J., III; Shelton, Kevin J.; Williams, Steven P.

2009-01-01

Eight pilots participated as test subjects in a fixed-based simulation experiment to evaluate advanced vision display technologies such as Enhanced Vision (EV) and Synthetic Vision (SV) for providing terrain imagery on flight displays in a Lunar Lander Vehicle. Subjects were asked to fly 20 approaches to the Apollo 15 lunar landing site with four different display concepts - Baseline (symbology only with no terrain imagery), EV only (terrain imagery from Forward Looking Infra Red, or FLIR, and LIght Detection and Ranging, or LIDAR, sensors), SV only (terrain imagery from onboard database), and Fused EV and SV concepts. As expected, manual landing performance was excellent (within a meter of landing site center) and not affected by the inclusion of EV or SV terrain imagery on the Lunar Lander flight displays. Subjective ratings revealed significant situation awareness improvements with the concepts employing EV and/or SV terrain imagery compared to the Baseline condition that had no terrain imagery. In addition, display concepts employing EV imagery (compared to the SV and Baseline concepts which had none) were significantly better for pilot detection of intentional but unannounced navigation failures since this imagery provided an intuitive and obvious visual methodology to monitor the validity of the navigation solution.

Statistical model and first-principles simulation on concentration of HenV cluster and He bubble formation in α-Fe and W

NASA Astrophysics Data System (ADS)

Liu, Yue-Lin; Yu, Yang; Dai, Zhen-Hong

2015-01-01

Using first-principles calculations, we investigate the stabilities of He and Hen-vacancy (HenV) clusters in α-Fe and W. Vacancy formation energies are 2.08 eV in α-Fe and 3.11 eV in W, respectively. Single He in both α-Fe and W prefers to occupy the tetrahedral interstitial site. We recalculated the He solution energy considering the effect of zero-point energy (ZPE). The ZPEs of He in α-Fe and W at the tetrahedral (octahedral) interstitial site are 0.072 eV (0.031 eV) and 0.078 eV (0.034 eV), respectively. The trapping energies of single He at vacancy in α-Fe and W are -2.39 eV and -4.55 eV, respectively. By sequentially adding He into vacancy, a monovacancy trap up to 10 He atoms distributing in the vacancy vicinity. Based on the above results combined with statistical model, we evaluate the concentrations of all relevant HenV clusters as a function of He chemical potential. The critical HenV concentration is found to be ∼10-40 (atomic) at the critical temperature T = 600 K in α-Fe and T = 1600 K in W, respectively. Beyond the critical HenV concentrations, considerable HenV aggregate to form HenVm clusters. By further growing of HenVm, the HenVm clusters grow bigger resulting in the larger He bubble formation.

African Non-Human Primates Host Diverse Enteroviruses.

PubMed

Mombo, Illich Manfred; Lukashev, Alexander N; Bleicker, Tobias; Brünink, Sebastian; Berthet, Nicolas; Maganga, Gael D; Durand, Patrick; Arnathau, Céline; Boundenga, Larson; Ngoubangoye, Barthélémy; Boué, Vanina; Liégeois, Florian; Ollomo, Benjamin; Prugnolle, Franck; Drexler, Jan Felix; Drosten, Christian; Renaud, François; Rougeron, Virginie; Leroy, Eric

2017-01-01

Enteroviruses (EVs) belong to the family Picornaviridae and are responsible for mild to severe diseases in mammals including humans and non-human primates (NHP). Simian EVs were first discovered in the 1950s in the Old World Monkeys and recently in wild chimpanzee, gorilla and mandrill in Cameroon. In the present study, we screened by PCR EVs in 600 fecal samples of wild apes and monkeys that were collected at four sites in Gabon. A total of 32 samples were positive for EVs (25 from mandrills, 7 from chimpanzees, none from gorillas). The phylogenetic analysis of VP1 and VP2 genes showed that EVs identified in chimpanzees were members of two human EV species, EV-A and EV-B, and those identified in mandrills were members of the human species EV-B and the simian species EV-J. The identification of two novel enterovirus types, EV-B112 in a chimpanzee and EV-B113 in a mandrill, suggests these NHPs could be potential sources of new EV types. The identification of EV-B107 and EV90 that were previously found in humans indicates cross-species transfers. Also the identification of chimpanzee-derived EV110 in a mandrill demonstrated a wide host range of this EV. Further research of EVs in NHPs would help understanding emergence of new types or variants, and evaluating the real risk of cross-species transmission for humans as well for NHPs populations.

Enhanced vision flight deck technology for commercial aircraft low-visibility surface operations

NASA Astrophysics Data System (ADS)

Arthur, Jarvis J.; Norman, R. M.; Kramer, Lynda J.; Prinzel, Lawerence J.; Ellis, Kyle K.; Harrison, Stephanie J.; Comstock, J. R.

2013-05-01

NASA Langley Research Center and the FAA collaborated in an effort to evaluate the effect of Enhanced Vision (EV) technology display in a commercial flight deck during low visibility surface operations. Surface operations were simulated at the Memphis, TN (FAA identifier: KMEM) airfield during nighttime with 500 Runway Visual Range (RVR) in a high-fidelity, full-motion simulator. Ten commercial airline flight crews evaluated the efficacy of various EV display locations and parallax and minification effects. The research paper discusses qualitative and quantitative results of the simulation experiment, including the effect of EV display placement on visual attention, as measured by the use of non-obtrusive oculometry and pilot mental workload. The results demonstrated the potential of EV technology to enhance situation awareness which is dependent on the ease of access and location of the displays. Implications and future directions are discussed.

Enhanced Vision Flight Deck Technology for Commercial Aircraft Low-Visibility Surface Operations

NASA Technical Reports Server (NTRS)

Arthur, Jarvis J., III; Norman, R. Michael; Kramer, Lynda J.; Prinzel, Lawrence J., III; Ellis, Kyle K. E.; Harrison, Stephanie J.; Comstock, J. Ray

2013-01-01

NASA Langley Research Center and the FAA collaborated in an effort to evaluate the effect of Enhanced Vision (EV) technology display in a commercial flight deck during low visibility surface operations. Surface operations were simulated at the Memphis, TN (FAA identifier: KMEM) air field during nighttime with 500 Runway Visual Range (RVR) in a high-fidelity, full-motion simulator. Ten commercial airline flight crews evaluated the efficacy of various EV display locations and parallax and mini cation effects. The research paper discusses qualitative and quantitative results of the simulation experiment, including the effect of EV display placement on visual attention, as measured by the use of non-obtrusive oculometry and pilot mental workload. The results demonstrated the potential of EV technology to enhance situation awareness which is dependent on the ease of access and location of the displays. Implications and future directions are discussed.

Nuclear Protein Sam68 Interacts with the Enterovirus 71 Internal Ribosome Entry Site and Positively Regulates Viral Protein Translation.

PubMed

Zhang, Hua; Song, Lei; Cong, Haolong; Tien, Po

2015-10-01

Enterovirus 71 (EV71) recruits various cellular factors to assist in the replication and translation of its genome. Identification of the host factors involved in the EV71 life cycle not only will enable a better understanding of the infection mechanism but also has the potential to be of use in the development of antiviral therapeutics. In this study, we demonstrated that the cellular factor 68-kDa Src-associated protein in mitosis (Sam68) acts as an internal ribosome entry site (IRES) trans-acting factor (ITAF) that binds specifically to the EV71 5' untranslated region (5'UTR). Interaction sites in both the viral IRES (stem-loops IV and V) and the heterogeneous nuclear ribonucleoprotein K homology (KH) domain of Sam68 protein were further mapped using an electrophoretic mobility shift assay (EMSA) and biotin RNA pulldown assay. More importantly, dual-luciferase (firefly) reporter analysis suggested that overexpression of Sam68 positively regulated IRES-dependent translation of virus proteins. In contrast, both IRES activity and viral protein translation significantly decreased in Sam68 knockdown cells compared with the negative-control cells treated with short hairpin RNA (shRNA). However, downregulation of Sam68 did not have a significant inhibitory effect on the accumulation of the EV71 genome. Moreover, Sam68 was redistributed from the nucleus to the cytoplasm and interacts with cellular factors, such as poly(rC)-binding protein 2 (PCBP2) and poly(A)-binding protein (PABP), during EV71 infection. The cytoplasmic relocalization of Sam68 in EV71-infected cells may be involved in the enhancement of EV71 IRES-mediated translation. Since Sam68 is known to be a RNA-binding protein, these results provide direct evidence that Sam68 is a novel ITAF that interacts with EV71 IRES and positively regulates viral protein translation. The nuclear protein Sam68 is found as an additional new host factor that interacts with the EV71 IRES during infection and could potentially enhance the translation of virus protein. To our knowledge, this is the first report that describes Sam68 actively participating in the life cycle of EV71 at a molecular level. These studies will not only improve our understanding of the replication of EV71 but also have the potential for aiding in developing a therapeutic strategy against EV71 infection. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

A density functional study of atomic hydrogen and oxygen chemisorption on the relaxed (0001) surface of double hexagonal close packed americium

NASA Astrophysics Data System (ADS)

Dholabhai, P. P.; Atta-Fynn, R.; Ray, A. K.

2008-02-01

Ab initio total energy calculations within the framework of density functional theory have been performed for atomic hydrogen and oxygen chemisorption on the (0001) surface of double hexagonal packed americium using a full-potential all-electron linearized augmented plane wave plus local orbitals method. Chemisorption energies were optimized with respect to the distance of the adatom from the relaxed surface for three adsorption sites, namely top, bridge, and hollow hcp sites, the adlayer structure corresponding to coverage of a 0.25 monolayer in all cases. Chemisorption energies were computed at the scalar-relativistic level (no spin-orbit coupling NSOC) and at the fully relativistic level (with spin-orbit coupling SOC). The two-fold bridge adsorption site was found to be the most stable site for O at both the NSOC and SOC theoretical levels with chemisorption energies of 8.204 eV and 8.368 eV respectively, while the three-fold hollow hcp adsorption site was found to be the most stable site for H with chemisorption energies of 3.136 eV at the NSOC level and 3.217 eV at the SOC level. The respective distances of the H and O adatoms from the surface were found to be 1.196 Åand 1.164 Å. Overall our calculations indicate that chemisorption energies in cases with SOC are slightly more stable than the cases with NSOC in the 0.049 0.238 eV range. The work functions and net magnetic moments respectively increased and decreased in all cases compared with the corresponding quantities of bare dhcp Am (0001) surface. The partial charges inside the muffin-tins, difference charge density distributions, and the local density of states have been used to analyze the Am-adatom bond interactions in detail. The implications of chemisorption on Am 5f electron localization-delocalization are also discussed.

Genetic evolution of Human Enterovirus A71 subgenotype C4 in Shenzhen, China, 1998-2013.

PubMed

He, Yaqing; Zou, Linjie; Chong, Marc Ka Chun; Men, Ruoting; Xu, Wenbo; Yang, Hong; Yao, Xiangjie; Chen, Long; Xian, Huixia; Zhang, Hailong; Luo, Min; Cheng, Jinquan; Ma, Hanwu; Feng, Qianjin; Huang, Yun; Wang, Yujie; Yeoh, Eng-Kiong; Zee, Benny Chung-Ying; Zhou, Yuanping; He, Ming-Liang; Wang, Maggie Haitian

2016-06-01

Human Enterovirus A71 (EV-A71) is one of the severest enteroviruses that causes hand, foot, and mouth disease (HFMD) among children. This study identified the mutations of EV-A71 VP1 amino acid residues over a number of years and explored the possible association of identified mutations and HFMD epidemic outbreaks in Shenzhen, China. A total of 3760 stool specimens were collected from HFMD patients by Shenzhen Centers for Disease Control and Prevention (CDC) between 1998 and 2013. In total 289 VP1 strains were sequenced in this study, and amino acids mutation frequency was calculated. There were 2040 China nationwide sequences downloaded from Genebank as replication data. In our samples, 1036 subjects (27.6%) were EV-A71 infected. Three amino acid positions on VP1 protein were found to have high mutation prevalence. These are Q22H, S283T, and A289H. Site 22 showed a fast mutation fixation in the year 2008, at the time of the large scale epidemic outbreak in Shenzhen. Analysis of the nationwide data replicated the same trend of mutation prevalence of the three sites. The switching from Q to H on site 22 of the EV-A71 VP1 strain might be associated with the HFMD outbreak in Shenzhen in 2008. The identified amino acid sites 22, 283 and 289 provided information for developing anti-viral drugs against EV-A71 in the future. Copyright © 2016 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

The impact of electric vehicles on the outlook of future energy system

NASA Astrophysics Data System (ADS)

Zhuk, A.; Buzoverov, E.

2018-02-01

Active promotion of electric vehicles (EVs) and technology of fast EV charging in the medium term may cause significant peak loads on the energy system, what necessitates making strategic decisions related to the development of generating capacities, distribution networks with EV charging infrastructure, and priorities in the development of battery electric vehicles and vehicles with electrochemical generators. The paper analyses one of the most significant aspects of joint development of electric transport system and energy system in the conditions of substantial growth of energy consumption by EVs. The assessments of per-unit-costs of operation and depreciation of EV power unit were made, taking into consideration the expenses of electric power supply. The calculations show that the choice of electricity buffering method for EV fast charging depends on the character of electricity infrastructure in the region where the electric transport is operating. In the conditions of high density of electricity network and a large number of EVs, the stationary storage facilities or the technology of distributed energy storage in EV batteries - vehicle-to-grid (V2G) technology may be used for buffering. In the conditions of low density and low capacity of electricity networks, the most economical solution could be usage of EVs with traction power units based on the combination of air-aluminum electrochemical generator and a buffer battery of small capacity.

Development and testing of the EVS 2000 enhanced vision system

NASA Astrophysics Data System (ADS)

Way, Scott P.; Kerr, Richard; Imamura, Joe J.; Arnoldy, Dan; Zeylmaker, Richard; Zuro, Greg

2003-09-01

An effective enhanced vision system must operate over a broad spectral range in order to offer a pilot an optimized scene that includes runway background as well as airport lighting and aircraft operations. The large dynamic range of intensities of these images is best handled with separate imaging sensors. The EVS 2000 is a patented dual-band Infrared Enhanced Vision System (EVS) utilizing image fusion concepts to provide a single image from uncooled infrared imagers in both the LWIR and SWIR. The system is designed to provide commercial and corporate airline pilots with improved situational awareness at night and in degraded weather conditions. A prototype of this system was recently fabricated and flown on the Boeing Advanced Technology Demonstrator 737-900 aircraft. This paper will discuss the current EVS 2000 concept, show results taken from the Boeing Advanced Technology Demonstrator program, and discuss future plans for EVS systems.

SUMO Modification Stabilizes Enterovirus 71 Polymerase 3D To Facilitate Viral Replication

PubMed Central

Liu, Yan; Shu, Bo; Meng, Jin; Zhang, Yuan; Zheng, Caishang; Ke, Xianliang; Gong, Peng; Hu, Qinxue; Wang, Hanzhong

2016-01-01

ABSTRACT Accumulating evidence suggests that viruses hijack cellular proteins to circumvent the host immune system. Ubiquitination and SUMOylation are extensively studied posttranslational modifications (PTMs) that play critical roles in diverse biological processes. Cross talk between ubiquitination and SUMOylation of both host and viral proteins has been reported to result in distinct functional consequences. Enterovirus 71 (EV71), an RNA virus belonging to the family Picornaviridae, is a common cause of hand, foot, and mouth disease. Little is known concerning how host PTM systems interact with enteroviruses. Here, we demonstrate that the 3D protein, an RNA-dependent RNA polymerase (RdRp) of EV71, is modified by small ubiquitin-like modifier 1 (SUMO-1) both during infection and in vitro. Residues K159 and L150/D151/L152 were responsible for 3D SUMOylation as determined by bioinformatics prediction combined with site-directed mutagenesis. Also, primer-dependent polymerase assays indicated that mutation of SUMOylation sites impaired 3D polymerase activity and virus replication. Moreover, 3D is ubiquitinated in a SUMO-dependent manner, and SUMOylation is crucial for 3D stability, which may be due to the interplay between the two PTMs. Importantly, increasing the level of SUMO-1 in EV71-infected cells augmented the SUMOylation and ubiquitination levels of 3D, leading to enhanced replication of EV71. These results together suggested that SUMO and ubiquitin cooperatively regulated EV71 infection, either by SUMO-ubiquitin hybrid chains or by ubiquitin conjugating to the exposed lysine residue through SUMOylation. Our study provides new insight into how a virus utilizes cellular pathways to facilitate its replication. IMPORTANCE Infection with enterovirus 71 (EV71) often causes neurological diseases in children, and EV71 is responsible for the majority of fatalities. Based on a better understanding of interplay between virus and host cell, antiviral drugs against enteroviruses may be developed. As a dynamic cellular process of posttranslational modification, SUMOylation regulates global cellular protein localization, interaction, stability, and enzymatic activity. However, little is known concerning how SUMOylation directly influences virus replication by targeting viral polymerase. Here, we found that EV71 polymerase 3D was SUMOylated during EV71 infection and in vitro. Moreover, the SUMOylation sites were determined, and in vitro polymerase assays indicated that mutations at SUMOylation sites could impair polymerase synthesis. Importantly, 3D is ubiquitinated in a SUMOylation-dependent manner that enhances the stability of the viral polymerase. Our findings indicate that the two modifications likely cooperatively enhance virus replication. Our study may offer a new therapeutic strategy against virus replication. PMID:27630238

Enterovirus 3A Facilitates Viral Replication by Promoting Phosphatidylinositol 4-Kinase IIIβ–ACBD3 Interaction

PubMed Central

Xiao, Xia; Lei, Xiaobo; Zhang, Zhenzhen; Ma, Yijie; Qi, Jianli; Wu, Chao; Xiao, Yan; Li, Li

2017-01-01

ABSTRACT Like other enteroviruses, enterovirus 71 (EV71) relies on phosphatidylinositol 4-kinase IIIβ (PI4KB) for genome RNA replication. However, how PI4KB is recruited to the genome replication sites of EV71 remains elusive. Recently, we reported that a host factor, ACBD3, is needed for EV71 replication by interacting with viral 3A protein. Here, we show that ACBD3 is required for the recruitment of PI4KB to RNA replication sites. Overexpression of viral 3A or EV71 infection stimulates the interaction of PI4KB and ACBD3. Consistently, EV71 infection induces the production of phosphatidylinositol-4-phosphate (PI4P). Furthermore, PI4KB, ACBD3, and 3A are all localized to the viral-RNA replication sites. Accordingly, PI4KB or ACBD3 depletion by small interfering RNA (siRNA) leads to a reduction in PI4P production after EV71 infection. I44A or H54Y substitution in 3A interrupts the stimulation of PI4KB and ACBD3. Further analysis suggests that stimulation of ACBD3-PI4KB interaction is also important for the replication of enterovirus 68 but disadvantageous to human rhinovirus 16. These results reveal a mechanism of enterovirus replication that involves a selective strategy for recruitment of PI4KB to the RNA replication sites. IMPORTANCE Enterovirus 71, like other human enteroviruses, replicates its genome within host cells, where viral proteins efficiently utilize cellular machineries. While multiple factors are involved, it is largely unclear how viral replication is controlled. We show that the 3A protein of enterovirus 71 recruits an enzyme, phosphatidylinositol 4-kinase IIIβ, by interacting with ACBD3, which alters cellular membranes through the production of a lipid, PI4P. Consequently, the viral and host proteins form a large complex that is necessary for RNA synthesis at replication sites. Notably, PI4KB-ACBD3 interaction also differentially mediates the replication of enterovirus 68 and rhinovirus 16. These results provide new insight into the molecular network of enterovirus replication. PMID:28701404

Do PEV Drivers Park Near Publicly Accessible EVSE in San Diego but Not Use Them?

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

Francfort, James Edward

The PEV charging stations deployed as part of The EV Project included both residential and non-residential sites. Non-residential sites included EVSE installed in workplace environments, fleet applications and those that were publicly accessible near retail centers, parking lots, and similar locations. The EV Project utilized its Micro-Climate® planning process to determine potential sites for publicly accessible EVSE in San Diego. This process worked with local stakeholders to target EVSE deployment near areas where significant PEV traffic and parking was expected. This planning process is described in The Micro-Climate deployment Process in San Diego1. The EV Project issued its deployment planmore » for San Diego in November 2010, prior to the sale of PEVs by Nissan and Chevrolet. The Project deployed residential EVSE concurrent with vehicle delivery starting in December 2010. The installation of non-residential EVSE commenced in April 2011 consistent with the original Project schedule, closely following the adoption of PEVs. The residential participation portion of The EV Project was fully subscribed by January 2013 and the non-residential EVSE deployment was essentially completed by August 2013.« less

Field Evaluation of Medium-Duty Plug-in Electric Delivery Trucks

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

Prohaska, Robert; Simpson, Mike; Ragatz, Adam

2016-12-01

This report focuses on medium-duty electric delivery vehicles operated by Frito-Lay North America (FLNA) at its Federal Way, Washington, distribution center. The 100% electric drive system is an alternative to conventional diesel delivery trucks and reduces both energy consumption and carbon dioxide (CO2) emissions. The vehicles' drive cycles and operation are analyzed and compared to demonstrate the importance of matching specific electric vehicle (EV) technologies to the appropriate operational duty cycle. The results of this analysis show that the Smith Newton EVs demonstrated a 68% reduction in energy consumption over the data reporting period compared to the conventional diesel vehicles,more » as well as a 46.4% reduction in CO 2 equivalent emissions based on the local energy generation source. In addition to characterizing the in-use performance of the EVs compared to the conventional diesels, detailed facility load data were collected at the main building power feed as well as from each of the 10 EV chargers to better understand the broader implications associated with commercial EV deployment. These facility loads were incorporated into several modeling scenarios to demonstrate the potential benefits of integrating onsite renewables.« less

Degradation of Alkali-Based Photocathodes from Exposure to Residual Gases: A First-Principles Study

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

Wang, Gaoxue; Pandey, Ravindra; Moody, Nathan A.

Photocathodes are a key component in the production of electron beams in systems such as X-ray free-electron lasers and X-ray energy-recovery linacs. Alkali-based materials display high quantum efficiency (QE), however, their QE undergoes degradation faster than metal photocathodes even in the high vacuum conditions where they operate. The high reactivity of alkali-based surfaces points to surface reactions with residual gases as one of the most important factors for the degradation of QE. In order to advance the understanding on the degradation of the QE, we investigated the surface reactivity of common residual gas molecules (e.g., O 2, CO 2, CO,more » H 2O, N 2, and H 2) on one of the best-known alkali-based photocathode materials, cesium antimonide (Cs 3Sb), using first-principles calculations based on density functional theory. Furthermore, the reaction sites, adsorption energy, and effect in the local electronic structure upon reaction of these molecules on (001), (110), and (111) surfaces of Cs 3Sb were computed and analyzed. The adsorption energy of these molecules on Cs3Sb follows the trend of O 2 (-4.5 eV) > CO 2 (-1.9 eV) > H 2O (-1.0 eV) > CO (-0.8 eV) > N 2 (-0.3 eV) ≈ H 2 (-0.2 eV), which agrees with experimental data on the effect of these gases on the degradation of QE. The interaction strength is determined by the charge transfer from the surfaces to the molecules. The adsorption and dissociation of O containing molecules modify the surface chemistry such as the composition, structure, charge distribution, surface dipole, and work function of Cs 3Sb, resulting in the degradation of QE with exposure to O 2, CO 2, H 2O, and CO.« less

Degradation of Alkali-Based Photocathodes from Exposure to Residual Gases: A First-Principles Study

DOE PAGES

Wang, Gaoxue; Pandey, Ravindra; Moody, Nathan A.; ...

2017-03-31

Photocathodes are a key component in the production of electron beams in systems such as X-ray free-electron lasers and X-ray energy-recovery linacs. Alkali-based materials display high quantum efficiency (QE), however, their QE undergoes degradation faster than metal photocathodes even in the high vacuum conditions where they operate. The high reactivity of alkali-based surfaces points to surface reactions with residual gases as one of the most important factors for the degradation of QE. In order to advance the understanding on the degradation of the QE, we investigated the surface reactivity of common residual gas molecules (e.g., O 2, CO 2, CO,more » H 2O, N 2, and H 2) on one of the best-known alkali-based photocathode materials, cesium antimonide (Cs 3Sb), using first-principles calculations based on density functional theory. Furthermore, the reaction sites, adsorption energy, and effect in the local electronic structure upon reaction of these molecules on (001), (110), and (111) surfaces of Cs 3Sb were computed and analyzed. The adsorption energy of these molecules on Cs3Sb follows the trend of O 2 (-4.5 eV) > CO 2 (-1.9 eV) > H 2O (-1.0 eV) > CO (-0.8 eV) > N 2 (-0.3 eV) ≈ H 2 (-0.2 eV), which agrees with experimental data on the effect of these gases on the degradation of QE. The interaction strength is determined by the charge transfer from the surfaces to the molecules. The adsorption and dissociation of O containing molecules modify the surface chemistry such as the composition, structure, charge distribution, surface dipole, and work function of Cs 3Sb, resulting in the degradation of QE with exposure to O 2, CO 2, H 2O, and CO.« less

Electric and hybrid vehicle program; Site Operator Program

NASA Astrophysics Data System (ADS)

Warren, J. F.

1992-05-01

Activities during the second quarter included the second meeting of the Site Operators in Phoenix, AZ in late April. The meeting was held in conjunction with the Solar and Electric 500 Race activities. Delivery of vehicles ordered previously has begun, although two of the operators are experiencing some delays in receiving their vehicles. Public demonstration activities continue, with an apparent increasing level of awareness and interest being displayed by the public. Initial problems with the Site Operator Database have been corrected and revised copies of the program have been supplied to the program participants. Operating and Maintenance data is being supplied and submitted to INEL on a monthly basis. Interest in the Site Operator Program is being reflected in requests for information from several organizations from across the country, representing a wide diversity of interests. These organizations have been referred to existing Site Operators with the explanation that the program will not be adding new participants, but that most of the existing organizations are willing to work with other groups. The exception to this was the addition of Potomac Electric Power Company (PEPCO) to the program. PEPCO has been awarded a subcontract to operate and maintain the DOE owned G-Van and Escort located in Washington, DC. They will provide data on these vehicles, as well as a Solectria Force which PEPCO has purchased. The Task Force intends to be actively involved in the infrastructure development in a wide range of areas. These include, among others, personnel development, safety, charging, and servicing. Work continues in these areas. York Technical College (YORK) has completed the draft outline for the EV Technician course. This is being circulated to organizations around the country for comments. Kansas State University (KSU) is working with a private sector company to develop a energy dispensing meter for opportunity charging in public areas.

A first-principles comparative study of lithium, sodium, and magnesium storage in pure and gallium-doped germanium: Competition between interstitial and substitutional sites

NASA Astrophysics Data System (ADS)

Legrain, Fleur; Manzhos, Sergei

2017-01-01

Thermodynamics and kinetics of Li, Na, and Mg storage in Ge are studied ab initio. The most stable configurations can consist of tetrahedral, substitutional, or a combination of the two types of sites. In the dilute limit, Li and Na prefer interstitial, while Mg prefers substitutional sites. At higher concentrations of Li, Na, and Mg, there is a combination of interstitial and substitutional sites. This is an important finding, as most previous ab initio studies of alloying type electrode materials ignored substitutional sites. Insertion energies computed at dilute concentration (x = 1/64) show that Na and Mg insertion are not thermodynamically favored in Ge vs. the formation of bulk Na and Mg, as opposed to Li insertion which is favored. We investigate the effect of p-doping of Ge (with Ga) on the thermodynamics and find that it considerably lowers the defect formation energies associated with the insertion of Li/Na/Mg at tetrahedral sites. On the other hand, the energetics associated with Li/Na/Mg insertion at substitutional sites are not significantly affected. In addition, we compute the migration energy barriers for Li/Na/Mg diffusion between two tetrahedral sites (0.38/0.79/0.66 eV), between two substitutional sites (0.77/0.93/1.83 eV), and between two sites of different types (2.15/1.75/0.85 eV).

A first-principles comparative study of lithium, sodium, and magnesium storage in pure and gallium-doped germanium: Competition between interstitial and substitutional sites.

PubMed

Legrain, Fleur; Manzhos, Sergei

2017-01-21

Thermodynamics and kinetics of Li, Na, and Mg storage in Ge are studied ab initio. The most stable configurations can consist of tetrahedral, substitutional, or a combination of the two types of sites. In the dilute limit, Li and Na prefer interstitial, while Mg prefers substitutional sites. At higher concentrations of Li, Na, and Mg, there is a combination of interstitial and substitutional sites. This is an important finding, as most previous ab initio studies of alloying type electrode materials ignored substitutional sites. Insertion energies computed at dilute concentration (x = 1/64) show that Na and Mg insertion are not thermodynamically favored in Ge vs. the formation of bulk Na and Mg, as opposed to Li insertion which is favored. We investigate the effect of p-doping of Ge (with Ga) on the thermodynamics and find that it considerably lowers the defect formation energies associated with the insertion of Li/Na/Mg at tetrahedral sites. On the other hand, the energetics associated with Li/Na/Mg insertion at substitutional sites are not significantly affected. In addition, we compute the migration energy barriers for Li/Na/Mg diffusion between two tetrahedral sites (0.38/0.79/0.66 eV), between two substitutional sites (0.77/0.93/1.83 eV), and between two sites of different types (2.15/1.75/0.85 eV).

The Evolution of Vp1 Gene in Enterovirus C Species Sub-Group That Contains Types CVA-21, CVA-24, EV-C95, EV-C96 and EV-C99

PubMed Central

Smura, Teemu; Blomqvist, Soile; Vuorinen, Tytti; Ivanova, Olga; Samoilovich, Elena; Al-Hello, Haider; Savolainen-Kopra, Carita; Hovi, Tapani; Roivainen, Merja

2014-01-01

Genus Enterovirus (Family Picornaviridae,) consists of twelve species divided into genetically diverse types by their capsid protein VP1 coding sequences. Each enterovirus type can further be divided into intra-typic sub-clusters (genotypes). The aim of this study was to elucidate what leads to the emergence of novel enterovirus clades (types and genotypes). An evolutionary analysis was conducted for a sub-group of Enterovirus C species that contains types Coxsackievirus A21 (CVA-21), CVA-24, Enterovirus C95 (EV-C95), EV-C96 and EV-C99. VP1 gene datasets were collected and analysed to infer the phylogeny, rate of evolution, nucleotide and amino acid substitution patterns and signs of selection. In VP1 coding gene, high intra-typic sequence diversities and robust grouping into distinct genotypes within each type were detected. Within each type the majority of nucleotide substitutions were synonymous and the non-synonymous substitutions tended to cluster in distinct highly polymorphic sites. Signs of positive selection were detected in some of these highly polymorphic sites, while strong negative selection was indicated in most of the codons. Despite robust clustering to intra-typic genotypes, only few genotype-specific ‘signature’ amino acids were detected. In contrast, when different enterovirus types were compared, there was a clear tendency towards fixation of type-specific ‘signature’ amino acids. The results suggest that permanent fixation of type-specific amino acids is a hallmark associated with evolution of different enterovirus types, whereas neutral evolution and/or (frequency-dependent) positive selection in few highly polymorphic amino acid sites are the dominant forms of evolution when strains within an enterovirus type are compared. PMID:24695547

The evolution of Vp1 gene in enterovirus C species sub-group that contains types CVA-21, CVA-24, EV-C95, EV-C96 and EV-C99.

PubMed

Smura, Teemu; Blomqvist, Soile; Vuorinen, Tytti; Ivanova, Olga; Samoilovich, Elena; Al-Hello, Haider; Savolainen-Kopra, Carita; Hovi, Tapani; Roivainen, Merja

2014-01-01

Genus Enterovirus (Family Picornaviridae,) consists of twelve species divided into genetically diverse types by their capsid protein VP1 coding sequences. Each enterovirus type can further be divided into intra-typic sub-clusters (genotypes). The aim of this study was to elucidate what leads to the emergence of novel enterovirus clades (types and genotypes). An evolutionary analysis was conducted for a sub-group of Enterovirus C species that contains types Coxsackievirus A21 (CVA-21), CVA-24, Enterovirus C95 (EV-C95), EV-C96 and EV-C99. VP1 gene datasets were collected and analysed to infer the phylogeny, rate of evolution, nucleotide and amino acid substitution patterns and signs of selection. In VP1 coding gene, high intra-typic sequence diversities and robust grouping into distinct genotypes within each type were detected. Within each type the majority of nucleotide substitutions were synonymous and the non-synonymous substitutions tended to cluster in distinct highly polymorphic sites. Signs of positive selection were detected in some of these highly polymorphic sites, while strong negative selection was indicated in most of the codons. Despite robust clustering to intra-typic genotypes, only few genotype-specific 'signature' amino acids were detected. In contrast, when different enterovirus types were compared, there was a clear tendency towards fixation of type-specific 'signature' amino acids. The results suggest that permanent fixation of type-specific amino acids is a hallmark associated with evolution of different enterovirus types, whereas neutral evolution and/or (frequency-dependent) positive selection in few highly polymorphic amino acid sites are the dominant forms of evolution when strains within an enterovirus type are compared.

Quantitative Investigation of Room-Temperature Breakdown Effects in Pixelated TlBr Detectors

NASA Astrophysics Data System (ADS)

Koehler, Will; He, Zhong; Thrall, Crystal; O'Neal, Sean; Kim, Hadong; Cirignano, Leonard; Shah, Kanai

2014-10-01

Due to favorable material properties such as high atomic number (Tl: 81, Br: 35), high density ( 7.56 g/cm3), and a wide band gap (2.68 eV), thallium-bromide (TlBr) is currently under investigation for use as an alternative room-temperature semiconductor gamma-ray spectrometer. TlBr detectors can achieve less than 1% FWHM energy resolution at 662 keV, but these results are limited to stable operation at - 20°C. After days to months of room-temperature operation, ionic conduction causes these devices to fail. This work correlates the varying leakage current with alpha-particle and gamma-ray spectroscopic performances at various operating temperatures. Depth-dependent photopeak centroids exhibit time-dependent transient behavior, which indicates trapping sites form near the anode surface during room-temperature operation. After refabrication, similar performance and functionality of failed detectors returned.

Diffusion of Cd and Te adatoms on CdTe(111) surfaces: A computational study using density functional theory

NASA Astrophysics Data System (ADS)

Naderi, Ebadollah; Nanavati, Sachin; Majumder, Chiranjib; Ghaisas, S. V.

2015-01-01

CdTe is one of the most promising semiconductor for thin-film based solar cells. Here we report a computational study of Cd and Te adatom diffusion on the CdTe (111) A-type (Cd terminated) and B-type (Te terminated) surfaces and their migration paths. The atomic and electronic structure calculations are performed under the DFT formalism and climbing Nudge Elastic Band (cNEB) method has been applied to evaluate the potential barrier of the Te and Cd diffusion. In general the minimum energy site on the surface is labeled as Aa site. In case of Te and Cd on B-type surface, the sub-surface site (a site just below the top surface) is very close in energy to the A site. This is responsible for the subsurface accumulation of adatoms and therefore, expected to influence the defect formation during growth. The diffusion process of adatoms is considered from Aa (occupied) to Aa (empty) site at the nearest distance. We have explored three possible migration paths for the adatom diffusion. The adatom surface interaction is highly dependent on the type of the surface. Typically, Te interaction with both type (5.2 eV for A-type and 3.8 eV for B-type) is stronger than Cd interactions(2.4 eV for B-type and 0.39 eV for A-type). Cd interaction with the A-type surface is very weak. The distinct behavior of the A-type and B-type surfaces perceived in our study explain the need of maintaining the A-type surface during growth for smooth and stoichiometric growth.

Passivation effect of Cl, F and H atoms on CuIn0.75Ga0.25Se2 (1 1 2) surface

NASA Astrophysics Data System (ADS)

Qi, Rong-fei; Wang, Zhao-hui; Tang, Fu-ling; Agbonkina, Itohan C.; Xue, Hong-tao; Si, Feng-juan; Ma, Sheng-ling; Wang, Xiao-ka

2018-06-01

Using the first-principles calculations within the density functional-theory (DFT) framework, we theoretically investigated the surface reconstruction, surface states near the Fermi level and their passivation on CuIn0.75Ga0.25Se2 (1 1 2) (CIGS) surface by chlorine, fluorine and hydrogen. Surface reconstruction appears on CIG-terminated CIGS (1 1 2) surface and it is a self-passivation. For the locations of Cl, F and H atoms adsorbing on Se-terminated CIGS (1 1 2) surface, four high symmetry adsorption sites: top sites, bridge sites, hexagonal close-packed (hcp) sites and faced centered cubic (fcc) sites were studied respectively. With the coverage of 0.5 monolayer (ML), Cl, F and H adatoms energetically occupy the top sites on the CIGS (112) surface. The corresponding adsorption energies were -2.20 eV, -3.29 eV, -2.60 eV, respectively. The bond length and electronic properties were analyzed. We found that the surface state density near the Fermi level was markedly diminished for 0.5 ML Cl, F and H adsorption on Se-terminated CIGS (1 1 2) surface at top sites. It was also found that H can more efficiently passivate the surface state density than Cl and F atoms, and the effect of adsorption of Cl atoms is better than that of F.

Cell emulation and preliminary results.

DOT National Transportation Integrated Search

2016-07-01

This report details preliminary results of the testing plan implemented by the Hawaii Natural Energy Institute to evaluate Electric Vehicle (EV) battery durability and reliability under electric utility grid operations. Commercial EV battery cells ar...

Inhibition of EV71 by curcumin in intestinal epithelial cells.

PubMed

Huang, Hsing-I; Chio, Chi-Chong; Lin, Jhao-Yin

2018-01-01

EV71 is a positive-sense single-stranded RNA virus that belongs to the Picornaviridae family. EV71 infection may cause various symptoms ranging from hand-foot-and-mouth disease to neurological pathological conditions such as aseptic meningitis, ataxia, and acute transverse myelitis. There is currently no effective treatment or vaccine available. Various compounds have been examined for their ability to restrict EV71 replication. However, most experiments have been performed in rhabdomyosarcoma or Vero cells. Since the gastrointestinal tract is the entry site for this pathogen, we anticipated that orally ingested agents may exert beneficial effects by decreasing virus replication in intestinal epithelial cells. In this study, curcumin (diferuloylmethane, C21H20O6), an active ingredient of turmeric (Curcuma longa Linn) with anti-cancer properties, was investigated for its anti-enterovirus activity. We demonstrate that curcumin treatment inhibits viral translation and increases host cell viability. Curcumin does not exert its anti-EV71 effects by modulating virus attachment or virus internal ribosome entry site (IRES) activity. Furthermore, curcumin-mediated regulation of mitogen-activated protein kinase (MAPK) signaling pathways is not involved. We found that protein kinase C delta (PKCδ) plays a role in virus translation in EV71-infected intestinal epithelial cells and that curcumin treatment decreases the phosphorylation of this enzyme. In addition, we show evidence that curcumin also limits viral translation in differentiated human intestinal epithelial cells. In summary, our data demonstrate the anti-EV71 properties of curcumin, suggesting that ingestion of this phytochemical may protect against enteroviral infections.

Inhibition of EV71 by curcumin in intestinal epithelial cells

PubMed Central

Chio, Chi-Chong; Lin, Jhao-Yin

2018-01-01

EV71 is a positive-sense single-stranded RNA virus that belongs to the Picornaviridae family. EV71 infection may cause various symptoms ranging from hand-foot-and-mouth disease to neurological pathological conditions such as aseptic meningitis, ataxia, and acute transverse myelitis. There is currently no effective treatment or vaccine available. Various compounds have been examined for their ability to restrict EV71 replication. However, most experiments have been performed in rhabdomyosarcoma or Vero cells. Since the gastrointestinal tract is the entry site for this pathogen, we anticipated that orally ingested agents may exert beneficial effects by decreasing virus replication in intestinal epithelial cells. In this study, curcumin (diferuloylmethane, C21H20O6), an active ingredient of turmeric (Curcuma longa Linn) with anti-cancer properties, was investigated for its anti-enterovirus activity. We demonstrate that curcumin treatment inhibits viral translation and increases host cell viability. Curcumin does not exert its anti-EV71 effects by modulating virus attachment or virus internal ribosome entry site (IRES) activity. Furthermore, curcumin-mediated regulation of mitogen-activated protein kinase (MAPK) signaling pathways is not involved. We found that protein kinase C delta (PKCδ) plays a role in virus translation in EV71-infected intestinal epithelial cells and that curcumin treatment decreases the phosphorylation of this enzyme. In addition, we show evidence that curcumin also limits viral translation in differentiated human intestinal epithelial cells. In summary, our data demonstrate the anti-EV71 properties of curcumin, suggesting that ingestion of this phytochemical may protect against enteroviral infections. PMID:29370243

Extravehicular activities guidelines and design criteria

NASA Technical Reports Server (NTRS)

Brown, N. E.; Dashner, T. R.; Hayes, B. C.

1973-01-01

A listing of astronaut EVA support systems and equipment, and the physical, operational, and performance characteristics of each major system are presented. An overview of the major ground based support operations necessary in the development and verification of orbital EVA systems is included. The performance and biomedical characteristics of man in the orbital EV environment are discussed. Major factors affecting astronaut EV work performance are identified and delineated as they relate to EV support systems design. Data concerning the medical and physiological aspects of spaceflight on man are included. The document concludes with an extensive bibliography, and a series of appendices which expand on some of the information presented in the main body.

Power control apparatus and methods for electric vehicles

DOEpatents

Gadh, Rajit; Chung, Ching-Yen; Chu, Chi-Cheng; Qiu, Li

2016-03-22

Electric vehicle (EV) charging apparatus and methods are described which allow the sharing of charge current between multiple vehicles connected to a single source of charging energy. In addition, this charge sharing can be performed in a grid-friendly manner by lowering current supplied to EVs when necessary in order to satisfy the needs of the grid, or building operator. The apparatus and methods can be integrated into charging stations or can be implemented with a middle-man approach in which a multiple EV charging box, which includes an EV emulator and multiple pilot signal generation circuits, is coupled to a single EV charge station.

Multi-spectrum-based enhanced synthetic vision system for aircraft DVE operations

NASA Astrophysics Data System (ADS)

Kashyap, Sudesh K.; Naidu, V. P. S.; Shanthakumar, N.

2016-04-01

This paper focus on R&D being carried out at CSIR-NAL on Enhanced Synthetic Vision System (ESVS) for Indian regional transport aircraft to enhance all weather operational capabilities with safety and pilot Situation Awareness (SA) improvements. Flight simulator has been developed to study ESVS related technologies and to develop ESVS operational concepts for all weather approach and landing and to provide quantitative and qualitative information that could be used to develop criteria for all-weather approach and landing at regional airports in India. Enhanced Vision System (EVS) hardware prototype with long wave Infrared sensor and low light CMOS camera is used to carry out few field trials on ground vehicle at airport runway at different visibility conditions. Data acquisition and playback system has been developed to capture EVS sensor data (image) in time synch with test vehicle inertial navigation data during EVS field experiments and to playback the experimental data on ESVS flight simulator for ESVS research and concept studies. Efforts are on to conduct EVS flight experiments on CSIR-NAL research aircraft HANSA in Degraded Visual Environment (DVE).

Physical properties of FePt nanocomposite doped with Ag atoms: First-principles study

NASA Astrophysics Data System (ADS)

Jia, Yong-Fei; Shu, Xiao-Lin; Xie, Yong; Chen, Zi-Yu

2014-07-01

L10 FePt nanocomposite with high magnetocrystalline anisotropy energy has been extensively investigated in the fields of ultra-high density magnetic recording media. However, the order—disorder transition temperature of the nanocomposite is higher than 600 °C, which is a disadvantage for the use of the material due to the sustained growth of FePt grain under the temperature. To address the problem, addition of Ag atoms has been proposed, but the magnetic properties of the doped system are still unclear so far. Here in this paper, we use first-principles method to study the lattice parameters, formation energy, electronic structure, atomic magnetic moment and order—disorder transition temperature of L10 FePt with Ag atom doping. The results show that the formation energy of a Ag atom substituting for a Pt site is 1.309 eV, which is lower than that of substituting for an Fe site 1.346 eV. The formation energy of substituting for the two nearest Pt sites is 2.560 eV lower than that of substituting for the further sites 2.621 eV, which indicates that Ag dopants tend to segregate L10 FePt. The special quasirandom structures (SQSs) for the pure FePt and the FePt doped with two Ag atoms at the stable Pt sites show that the order—disorder transition temperatures are 1377 °C and 600 °C, respectively, suggesting that the transition temperature can be reduced with Ag atom, and therefore the FePt grain growth is suppressed. The saturation magnetizations of the pure FePt and the two Ag atoms doped FePt are 1083 emu/cc and 1062 emu/cc, respectively, indicating that the magnetic property of the doped system is almost unchanged.

SIRT1 inhibits EV71 genome replication and RNA translation by interfering with the viral polymerase and 5′UTR RNA

PubMed Central

Han, Yang; Wang, Lvyin; Cui, Jin; Song, Yu; Luo, Zhen; Chen, Junbo; Xiong, Ying; Zhang, Qi; Liu, Fang; Ho, Wenzhe; Liu, Yingle; Wu, Jianguo

2016-01-01

ABSTRACT Enterovirus 71 (EV71) possesses a single-stranded positive RNA genome that contains a single open reading frame (ORF) flanked by a 5′ untranslated region (5′UTR) and a polyadenylated 3′UTR. Here, we demonstrated that EV71 activates the production of silent mating type information regulation 2 homolog 1 (SIRT1), a histone deacetylase (HDAC). EV71 further stimulates SIRT1 sumoylation and deacetylase activity, and enhances SIRT1 translocation from the nucleus to the cytoplasm. More interestingly, activated SIRT1 subsequently binds with the EV71 3Dpol protein (a viral RNA-dependent RNA polymerase, RdRp) to repress the acetylation and RdRp activity of 3Dpol, resulting in the attenuation of viral genome replication. Moreover, SIRT1 interacts with the cloverleaf structure of the EV71 RNA 5′UTR to inhibit viral RNA transcription, and binds to the internal ribosome entry site (IRES) of the EV71 5′UTR to attenuate viral RNA translation. Thus, EV71 stimulates SIRT1 production and activity, which in turn represses EV71 genome replication by inhibiting viral polymerase, and attenuates EV71 RNA transcription and translation by interfering with viral RNA. These results uncover a new function of SIRT1 and reveal a new mechanism underlying the regulation of EV71 replication. PMID:27875274

Awareness and Detection of Traffic and Obstacles Using Synthetic and Enhanced Vision Systems

NASA Technical Reports Server (NTRS)

Bailey, Randall E.

2012-01-01

Research literature are reviewed and summarized to evaluate the awareness and detection of traffic and obstacles when using Synthetic Vision Systems (SVS) and Enhanced Vision Systems (EVS). The study identifies the critical issues influencing the time required, accuracy, and pilot workload associated with recognizing and reacting to potential collisions or conflicts with other aircraft, vehicles and obstructions during approach, landing, and surface operations. This work considers the effect of head-down display and head-up display implementations of SVS and EVS as well as the influence of single and dual pilot operations. The influences and strategies of adding traffic information and cockpit alerting with SVS and EVS were also included. Based on this review, a knowledge gap assessment was made with recommendations for ground and flight testing to fill these gaps and hence, promote the safe and effective implementation of SVS/EVS technologies for the Next Generation Air Transportation System

Electrical characterization of 6H crystalline silicon carbide. M.S. Thesis Final Report

NASA Technical Reports Server (NTRS)

Lempner, Stephen E.

1994-01-01

Crystalline silicon carbide (SiC) substrates and epilayers, undoped as well as n- and p-doped, have been electrically characterized by performing Hall effect and resistivity measurements (van der Pauw) over the temperature range of approximately 85 K to 650 K (200 K to 500 K for p-type sample). By fitting the measured temperature dependent carrier concentration data to the single activation energy theoretical model: (1) the activation energy for the nitrogen donor ranged from 0.078 eV to 0.101 eV for a doping concentration range of 10(exp 17) cm(exp -3) to 10(exp 18) cm(exp -3) and (2) the activation energy for the aluminum acceptor was 0.252 eV for a doping concentration of 4.6 x 10(exp 18) cm(exp -3). By fitting the measured temperature dependent carrier concentration data to the double activation energy level theoretical model for the nitrogen donor: (1) the activation energy for the hexagonal site was 0.056 eV and 0.093 eV corresponding to doping concentrations of 3.33 x 10 (exp 17) cm(exp -3) and 1.6 x 10(exp 18) cm(exp -3) and (2) the activation energy for the cubic site was 0.113 and 0.126 eV corresponding to doping concentrations of 4.2 x 10(exp 17) cm(exp -3) and 5.4 x 10(exp 18) cm(exp -3).

Effects of hydration and oxygen vacancy on CO2 adsorption and activation on beta-Ga2O3(100).

PubMed

Pan, Yun-xiang; Liu, Chang-jun; Mei, Donghai; Ge, Qingfeng

2010-04-20

The effects of hydration and oxygen vacancy on CO(2) adsorption on the beta-Ga(2)O(3)(100) surface have been studied using density functional theory slab calculations. Adsorbed CO(2) is activated on the dry perfect beta-Ga(2)O(3)(100) surface, resulting in a carbonate species. This adsorption is slightly endothermic, with an adsorption energy of 0.07 eV. Water is preferably adsorbed molecularly on the dry perfect beta-Ga(2)O(3)(100) surface with an adsorption energy of -0.56 eV, producing a hydrated perfect beta-Ga(2)O(3)(100) surface. Adsorption of CO(2) on the hydrated surface as a carbonate species is also endothermic, with an adsorption energy of 0.14 eV, indicating a slightly repulsive interaction when H(2)O and CO(2) are coadsorbed. The carbonate species on the hydrated perfect surface can be protonated by the coadsorbed H(2)O to a bicarbonate species, making the CO(2) adsorption exothermic, with an adsorption energy of -0.13 eV. The effect of defects on CO(2) adsorption and activation has been examined by creating an oxygen vacancy on the dry beta-Ga(2)O(3)(100) surface. The formation of an oxygen vacancy is endothermic, by 0.34 eV, with respect to a free O(2) molecule in the gas phase. Presence of the oxygen vacancy promoted the adsorption and activation of CO(2). In the most stable CO(2) adsorption configuration on the dry defective beta-Ga(2)O(3)(100) surface with an oxygen vacancy, one of the oxygen atoms of the adsorbed CO(2) occupies the oxygen vacancy site, and the CO(2) adsorption energy is -0.31 eV. Water favors dissociative adsorption at the oxygen vacancy site on the defective surface. This process is spontaneous, with a reaction energy of -0.62 eV. These results indicate that, when water and CO(2) are present in the adsorption system simultaneously, water will compete with CO(2) for the oxygen vacancy sites and impact CO(2) adsorption and conversion negatively.

Density functional theory study of acetaldehyde hydrodeoxygenation on MoO3

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

Mei, Donghai; Karim, Ayman M.; Wang, Yong

2011-04-06

Periodic spin-polarized density functional theory calculations were performed to investigate acetaldehyde (CH3CHO) hydrodeoxygenation on the reduced molybdenum trioxide (MoO3) surface. The perfect O-terminated α-MoO3(010) surface is reduced to generate an oxygen defect site in the presence of H2. H2 dissociatively adsorbs at the surface oxygen sites forming two surface hydroxyls, which can recombine into a water molecule weakly bound at the Mo site. A terminal oxygen (Ot) defect site thus forms after water desorption. CH3CHO adsorbs at the O-deficient Mo site via either the sole O-Mo bond or the O-Mo and the C-O double bonds. The possible reaction pathways ofmore » the adsorbed CH3CHO with these two configurations were thoroughly examined using the dimer searching method. Our results show that the ideal deoxygenation of CH3CHO leading to ethylene (C2H4) on the reduced MoO3(010) surface is feasible. The adsorbed CH3CHO first dehydrogenate into CH2CHO by reacting with a neighboring terminal Ot. The hydroxyl (OtH) then hydrogenates CH2CHO into CH2CH2O to complete the hydrogen transfer cycle with an activation barrier of 1.39 eV. The direct hydrogen transfer from CH3CHO to CH2CH2O is unlikely due to the high barrier of 2.00 eV. The produced CH2CH2O readily decomposes into C2H4 that directly releases to the gas phase, and regenerates the Ot atom on the Mo site. As a result, the reduced MoO3(010) surface is reoxidized to the perfect MoO3(010) surface after CH3CHO deoxygenation. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.« less

MSC secretes at least 3 EV types each with a unique permutation of membrane lipid, protein and RNA.

PubMed

Lai, Ruenn Chai; Tan, Soon Sim; Yeo, Ronne Wee Yeh; Choo, Andre Boon Hwa; Reiner, Agnes T; Su, Yan; Shen, Yang; Fu, Zhiyan; Alexander, Lezhava; Sze, Siu Kwan; Lim, Sai Kiang

2016-01-01

Mesenchymal stem cell (MSC), a widely used adult stem cell candidate for regenerative medicine, has been shown to exert some of its therapeutic effects through the secretion of extracellular vesicles (EVs). These homogenously sized EVs of 100-150 ηm exhibited many exosome-like biophysical and biochemical properties and carry both proteins and RNAs. Recently, exosome-associated proteins in this MSC EV preparation were found to segregate primarily to those EVs that bind cholera toxin B chain (CTB), a GM1 ganglioside-specific ligand, and pulse-chase experiments demonstrated that these EVs have endosomal origin and carried many of the exosome-associated markers. Here, we report that only a fraction of the MSC EV proteome was found in CTB-bound EVs. Using Annexin V (AV) and Shiga toxin B subunit (ST) with affinities for phosphatidylserine and globotriaosylceramide, respectively, AV- and a ST-binding EV were identified. CTB-, AV- and ST-binding EVs all carried actin. However, the AV-binding EVs carried low or undetectable levels of the exosome-associated proteins. Only the ST-binding EVs carried RNA and EDA-containing fibronectin. Proteins in AV-binding EVs were also different from those released by apoptotic MSCs. CTB- and AV-binding activities were localized to the plasma membrane and cytoplasm of MSCs, while ST-binding activity was localized to the nucleus. Together, this study demonstrates that cells secrete many types of EVs. Specifically, MSCs secrete at least 3 types. They can be differentially isolated based on their affinities for membrane lipid-binding ligands. As the subcellular sites of the binding activities of these ligands and cargo load are different for each EV type, they are likely to have a different biogenesis pathway and possibly different functions.

The Arctic Boreal Vulnerability Experiment (ABoVE) 2017 Airborne Campaign

NASA Astrophysics Data System (ADS)

Miller, C. E.; Goetz, S. J.; Griffith, P. C.; Hoy, E.; Larson, E. K.; Hodkinson, D. J.; Hansen, C.; Woods, J.; Kasischke, E. S.; Margolis, H. A.

2017-12-01

The 2017 ABoVE Airborne Campaign (AAC) was one of the largest airborne experiments ever conducted by NASA's Earth Science Division. It involved nine aircraft in 17 deployments - more than 100 flights - between April and October and sampled over 4 million km2in Alaska and northwestern Canada. Many of these flights were coordinated with detailed, same-day ground-based measurements to link field-based, process-level studies with geospatial data products derived from satellite remote sensing. A major goal of the 2017 AAC was to collect data that spanned the critical intermediate space and time scales that are essential for a comprehensive understanding of scaling issues across the ABoVE Study Domain and extrapolation to the pan-Arctic. Additionally, the 2017 AAC provided unique opportunities to validate satellite and airborne remote sensing data for northern high latitude ecosystems, develop and advance fundamental remote sensing science, and explore scientific insights from innovative sensor combinations. The 2017 AAC science strategy coupled domain-wide sampling with L-band and P-band synthetic aperture radar (SAR), imaging spectroscopy (AVIRIS-NG), full waveform lidar (LVIS) and atmospheric carbon dioxide and methane with more spatially and temporally focused studies using Ka-band SAR (Ka-SPAR) and solar induced chlorophyll fluorescence (CFIS). Additional measurements were coordinated with the NEON Airborne Observing Platform, the ASCENDS instrument development suite, and the ATOM EV-S2 investigation. Targets of interest included the array of field sites operated by the ABoVE Science Team as well as the intensive sites operated by the DOE NGEE-Arctic team on the Seward Peninsula and in Barrow, NSF's LTER sites at Toolik Lake (North Slope) and Bonanza Creek (Interior Alaska), the Canadian Cold Regions Hydrology sites in the Arctic tundra near Trail Valley Creek NT, the Government of the Northwest Territories Slave River/Slave Delta watershed time series and numerous forest and fire disturbance plots maintained by the Alaskan and Canadian Forestry Services. We will present an overview of the 2017 AAC and highlight some key preliminary results.

From clusters to bulk: A relativistic density functional investigation on a series of gold clusters Aun, n=6,…,147

NASA Astrophysics Data System (ADS)

Häberlen, Oliver D.; Chung, Sai-Cheong; Stener, Mauro; Rösch, Notker

1997-03-01

A series of gold clusters spanning the size range from Au6 through Au147 (with diameters from 0.7 to 1.7 nm) in icosahedral, octahedral, and cuboctahedral structure has been theoretically investigated by means of a scalar relativistic all-electron density functional method. One of the main objectives of this work was to analyze the convergence of cluster properties toward the corresponding bulk metal values and to compare the results obtained for the local density approximation (LDA) to those for a generalized gradient approximation (GGA) to the exchange-correlation functional. The average gold-gold distance in the clusters increases with their nuclearity and correlates essentially linearly with the average coordination number in the clusters. An extrapolation to the bulk coordination of 12 yields a gold-gold distance of 289 pm in LDA, very close to the experimental bulk value of 288 pm, while the extrapolated GGA gold-gold distance is 297 pm. The cluster cohesive energy varies linearly with the inverse of the calculated cluster radius, indicating that the surface-to-volume ratio is the primary determinant of the convergence of this quantity toward bulk. The extrapolated LDA binding energy per atom, 4.7 eV, overestimates the experimental bulk value of 3.8 eV, while the GGA value, 3.2 eV, underestimates the experiment by almost the same amount. The calculated ionization potentials and electron affinities of the clusters may be related to the metallic droplet model, although deviations due to the electronic shell structure are noticeable. The GGA extrapolation to bulk values yields 4.8 and 4.9 eV for the ionization potential and the electron affinity, respectively, remarkably close to the experimental polycrystalline work function of bulk gold, 5.1 eV. Gold 4f core level binding energies were calculated for sites with bulk coordination and for different surface sites. The core level shifts for the surface sites are all positive and distinguish among the corner, edge, and face-centered sites; sites in the first subsurface layer show still small positive shifts.

Battery cycling and calendar aging: year one testing results.

DOT National Transportation Integrated Search

2016-07-01

This report is meant to provide an update on the ongoing battery testing performed by the Hawaii Natural Energy Institute to evaluate Electric Vehicle (EV) battery durability and reliability under electric utility grid operations. Commercial EV batte...

Characterization of In-Use Medium Duty Electric Vehicle Driving and Charging Behavior: Preprint

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

Duran, A.; Ragatz, A.; Prohaska, R.

2014-11-01

The U.S. Department of Energy's American Recovery and Reinvestment Act (ARRA) deployment and demonstration projects are helping to commercialize technologies for all-electric vehicles (EVs). Under the ARRA program, data from Smith Electric and Navistar medium duty EVs have been collected, compiled, and analyzed in an effort to quantify the impacts of these new technologies. Over a period of three years, the National Renewable Energy Laboratory (NREL) has compiled data from over 250 Smith Newton EVs for a total of over 100,000 days of in-use operation. Similarly, data have been collected from over 100 Navistar eStar vehicles, with over 15,000 operatingmore » days having been analyzed. NREL has analyzed a combined total of over 4 million kilometers of driving and 1 million hours of charging data for commercial operating medium duty EVs. In this paper, the authors present an overview of medium duty EV operating and charging behavior based on in-use data collected from both Smith and Navistar vehicles operating in the United States. Specifically, this paper provides an introduction to the specifications and configurations of the vehicles examined; discusses the approach and methodology of data collection and analysis, and presents detailed results regarding daily driving and charging behavior. In addition, trends observed over the course of multiple years of data collection are examined, and conclusions are drawn about early deployment behavior and ongoing adjustments due to new and improving technology. Results and metrics such as average daily driving distance, route aggressiveness, charging frequency, and liter per kilometer diesel equivalent fuel consumption are documented and discussed.« less

Strong influence of off-site symmetry positions of hydrogen atoms in ScH3 hcp phases

NASA Astrophysics Data System (ADS)

Pakornchote, T.; Bovornratanaraks, T.; Vannarat, S.; Pinsook, U.

2016-01-01

We investigate the wave-like arrangements of H atoms around metal plane (Hm) in the ScH3 hcp phase by using the ab-initio method. We found that only P63 / mmc, P 3 bar c 1, P63cm and P63 phases are energetically favorable. The wave-like arrangement allows the off-site symmetry positions of the H atoms, and leads to substantial changes in the pair distribution between Sc and H atoms which are associating with the changes in the electronic structure in such a way that the total energy is lowering. The symmetry breaking from P63mmc is also responsible for the band gap opening. In the P63 structure, the calculated band gap is 0.823 eV and 1.223 eV using GGA and sX-LDA functionals, respectively. This band gap can be compared with 1.7 eV derived from the optical measurement and 1.55 eV from the HSE06 calculation. Thus, the broken symmetry structures can be viewed as Peierls distortion of the P63 / mmc structure. Furthermore, we found that only the P63 structure is dynamically stable, unlike YH3 where the P63cm structure is also stable. The stability of P63 comes from sufficiently strong interactions between two neighboring H atoms at their off-site symmetry positions, i.e. near the metal plane and near the tetragonal site. The P63 phonon density of states is in good agreement with the data from the neutron experiment.

Identification of specific antigenic epitope at N-terminal segment of enterovirus 71 (EV-71) VP1 protein and characterization of its use in recombinant form for early diagnosis of EV-71 infection.

PubMed

Zhang, Jianhua; Jiang, Bingfu; Xu, Mingjie; Dai, Xing; Purdy, Michael A; Meng, Jihong

2014-08-30

Human enterovirus 71 (EV-71) is the main etiologic agent of hand, foot and mouth disease (HFMD). We sought to identify EV-71 specific antigens and develop serologic assays for acute-phase EV-71 infection. A series of truncated proteins within the N-terminal 100 amino acids (aa) of EV-71 VP1 was expressed in Escherichia coli. Western blot (WB) analysis showed that positions around 11-21 aa contain EV-71-specific antigenic sites, whereas positions 1-5 and 51-100 contain epitopes shared with human coxsackievirus A16 (CV-A16) and human echovirus 6 (E-6). The N-terminal truncated protein of VP1, VP₁₆₋₄₃, exhibited good stability and was recognized by anti-EV-71 specific rabbit sera. Alignment analysis showed that VP₁₆₋₄₃ is highly conserved among EV-71 strains from different genotypes but was heterologous among other enteroviruses. When the GST-VP₁₆₋₄₃ fusion protein was incorporated as antibody-capture agent in a WB assay and an ELISA for detecting anti-EV-71 IgM in human sera, sensitivities of 91.7% and 77.8% were achieved, respectively, with 100% specificity for both. The characterized EV-71 VP1 protein truncated to positions 6-43 aa has potential as an antigen for detection of anti-EV-71 IgM for early diagnosis of EV-71 infection in a WB format. Copyright © 2014 Elsevier B.V. All rights reserved.

Nuclear transport of cancer extracellular vesicle-derived biomaterials through nuclear envelope invagination-associated late endosomes.

PubMed

Rappa, Germana; Santos, Mark F; Green, Toni M; Karbanová, Jana; Hassler, Justin; Bai, Yongsheng; Barsky, Sanford H; Corbeil, Denis; Lorico, Aurelio

2017-02-28

Extracellular membrane vesicles (EVs) function as vehicles of intercellular communication, but how the biomaterials they carry reach the target site in recipient cells is an open question. We report that subdomains of Rab7+ late endosomes and nuclear envelope invaginations come together to create a sub-nuclear compartment, where biomaterials associated with CD9+ EVs are delivered. EV-derived biomaterials were also found in the nuclei of host cells. The inhibition of nuclear import and export pathways abrogated the nuclear localization of EV-derived biomaterials or led to their accumulation therein, respectively, suggesting that their translocation is dependent on nuclear pores. Nuclear envelope invagination-associated late endosomes were observed in ex vivo biopsies in both breast carcinoma and associated stromal cells. The transcriptome of stromal cells exposed to cancer cell-derived CD9+ EVs revealed that the regulation of eleven genes, notably those involved in inflammation, relies on the nuclear translocation of EV-derived biomaterials. Our findings uncover a new cellular pathway used by EVs to reach nuclear compartment.

Ab initio full-potential fully relativistic study of atomic carbon, nitrogen, and oxygen chemisorption on the (111) surface of δ-Pu

NASA Astrophysics Data System (ADS)

Atta-Fynn, Raymond; Ray, Asok K.

2007-05-01

First-principles total-energy calculations within the framework of generalized gradient approximation to density-functional theory have been performed for atomic carbon, nitrogen, and oxygen chemisorption on the (111) surface of δ-Pu . The full-potential all-electron linearized augmented plane wave plus local orbitals method with the Perdew-Burke-Ernzerhof exchange-correlation functional has been employed. Chemisorption energies have been optimized with respect to the distance of the adatom from the Pu surface for four adsorption sites, namely, the top, bridge, hollow fcc, and hollow hcp sites, with the adlayer structure corresponding to a coverage of 0.50 of a monolayer in all cases. Computations were carried out at two theoretical levels, one without spin-orbit coupling (NSOC) and one with spin-orbit coupling (SOC). For NSOC calculations, the hollow fcc adsorption site was found to be the most stable site for C and N with chemisorption energies of 6.272 and 6.504eV , respectively, while the hollow hcp adsorption site was found to be the most stable site for O with chemisorption energy of 8.025eV . For SOC calculations, the hollow fcc adsorption site was found to be the most stable site in all cases with chemisorption energies for C, N, and O being 6.539, 6.714, and 8.2eV , respectively. The respective distances of the C, N, and O adatoms from the surface were found to be 1.16, 1.08, and 1.25Å . Our calculations indicate that SOC has negligible effect on the chemisorption geometries, but energies with SOC are more stable than the cases with NSOC within a range of 0.05-0.27eV . The work function and net magnetic moments, respectively, increased and decreased in all cases upon chemisorption compared with the bare δ-Pu (111) surface. The partial charges inside the muffin tins, difference charge-density distributions, and the local density of states have been used to analyze the Pu-adatom bond interactions.

Structural, electronic and optical properties of CO adsorbed on the defective anatase TiO2 (101) surface; a DFT study

NASA Astrophysics Data System (ADS)

Rafique, Muhammad; Shuai, Yong; Hassan, Muhammad

2017-08-01

This paper illustrates the study of stable structural, electronic and optical properties of carbon mono oxide (CO) molecule adsorbed on pure anatase TiO2 (101) surface and CO molecule adsorbed on defective anatase TiO2 (101) surface containing oxygen (O) atom subsurface vacancy using first-principles study calculations based on density functional theory (DFT) method. A foreign molecule CO was added in the interstitial space of anatase TiO2 (101) surface. It was observed that, adsorption of CO molecule is not favorable on pure anatase TiO2 (101) surface, however adsorption process is improved when subsurface contains O atom vacancy defect. In case of anatase TiO2 (101) surface containing subsurface vacancy, adsorption process is exothermic, resulting in stable structures. The adsorption energies calculated for CO molecules adsorbed at O2c site, at defect site and at Ti5c site of anatase surface containing subsurface O vacancy are 0.16 eV (at O2c), 0.32 eV (at defect site) and 0.43 eV (at Ti5c) site. DOS and PDOS plots are calculated for all the structures. Results indicated that CO molecule adsorption introduces surface states at the Fermi energy level (EF) as shown in partial density of states (PDOS) plots. The dielectric matrix and absorption coefficient (α) for defective anatase TiO2 (101) surface, CO adsorbed at O2c site, at defect site and at Ti5C site of anatase TiO2 (101) surface containing O atom subsurface vacancy has been calculated within the random phase approximation (RPA) using VASP (Vienna ab-initio simulation package) code. It was observed that upon CO adsorption at defective anatase surface, real and imaginary dielectric function peaks were shifted towards lower energy level and a small absorption peak was observed at 1.1 eV energy level which is not present in case of defective anatase (101) surface. CO adsorption produces a red shift in the absorption spectrum of anatase TiO2 (101) surface containing subsurface O atom vacancy.

Diffusion of hydrogen into and through γ-iron by density functional theory

NASA Astrophysics Data System (ADS)

Chohan, Urslaan K.; Koehler, Sven P. K.; Jimenez-Melero, Enrique

2018-06-01

This study is concerned with the early stages of hydrogen embrittlement on an atomistic scale. We employed density functional theory to investigate hydrogen diffusion through the (100), (110) and (111) surfaces of γ-Fe. The preferred adsorption sites and respective energies for hydrogen adsorption were established for each plane, as well as a minimum energy pathway for diffusion. The H atoms adsorb on the (100), (110) and (111) surfaces with energies of ∼4.06 eV, ∼3.92 eV and ∼4.05 eV, respectively. The barriers for bulk-like diffusion for the (100), (110) and (111) surfaces are ∼0.6 eV, ∼0.5 eV and ∼0.7 eV, respectively. We compared these calculated barriers with previously obtained experimental data in an Arrhenius plot, which indicates good agreement between experimentally measured and theoretically predicted activation energies. Texturing austenitic steels such that the (111) surfaces of grains are preferentially exposed at the cleavage planes may be a possibility to reduce hydrogen embrittlement.

Electric Vehicles Charging Scheduling Strategy Considering the Uncertainty of Photovoltaic Output

NASA Astrophysics Data System (ADS)

Wei, Xiangxiang; Su, Su; Yue, Yunli; Wang, Wei; He, Luobin; Li, Hao; Ota, Yutaka

2017-05-01

The rapid development of electric vehicles and distributed generation bring new challenges to security and economic operation of the power system, so the collaborative research of the EVs and the distributed generation have important significance in distribution network. Under this background, an EVs charging scheduling strategy considering the uncertainty of photovoltaic(PV) output is proposed. The characteristics of EVs charging are analysed first. A PV output prediction method is proposed with a PV database then. On this basis, an EVs charging scheduling strategy is proposed with the goal to satisfy EVs users’ charging willingness and decrease the power loss in distribution network. The case study proves that the proposed PV output prediction method can predict the PV output accurately and the EVs charging scheduling strategy can reduce the power loss and stabilize the fluctuation of the load in distributed network.

A study on native defects and magnetic properties in undoped rutile TiO2 using LDA and LDA+UO p+UTi d methods

NASA Astrophysics Data System (ADS)

Shi, Li-Bin; Wang, Yong Ping

2016-05-01

The native defects and magnetic properties in undoped rutile TiO2 are studied using local density approximation (LDA) and LDA adding Hubbard parameters (U) schemes. The band gap is adjusted to experimental value of 3.0 eV by combination of UTi d=4.2 eV and UO p=4.8 eV. This LDA+U methodology overcomes the band-gap problem and renders the approach more predictive. The formation energies of oxygen vacancy (VO), oxygen interstitial (Oi), titanium vacancy (VTi), titanium interstitial (Tii), oxygen anti-sites (OTi), and titanium anti-sites (TiO) are investigated by the LDA and LDA+U methods. In addition, some ground state configurations can be obtained by optimization of total spin. It is found that native defects can induce spin polarization and produce magnetic moment.

Real-time sub-Ångstrom imaging of reversible and irreversible conformations in rhodium catalysts and graphene

NASA Astrophysics Data System (ADS)

Kisielowski, Christian; Wang, Lin-Wang; Specht, Petra; Calderon, Hector A.; Barton, Bastian; Jiang, Bin; Kang, Joo H.; Cieslinski, Robert

2013-07-01

The dynamic responses of a rhodium catalyst and a graphene sheet are investigated upon random excitation with 80 kV electrons. An extraordinary electron microscope stability and resolution allow studying temporary atom displacements from their equilibrium lattice sites into metastable sites across projected distances as short as 60 pm. In the rhodium catalyst, directed and reversible atom displacements emerge from excitations into metastable interstitial sites and surface states that can be explained by single atom trajectories. Calculated energy barriers of 0.13 eV and 1.05 eV allow capturing single atom trapping events at video rates that are stabilized by the Rh [110] surface corrugation. Molecular dynamics simulations reveal that randomly delivered electrons can also reversibly enhance the sp3 and the sp1 characters of the sp2-bonded carbon atoms in graphene. The underlying collective atom motion can dynamically stabilize characteristic atom displacements that are unpredictable by single atom trajectories. We detect three specific displacements and use two of them to propose a path for the irreversible phase transformation of a graphene nanoribbon into carbene. Collectively stabilized atom displacements greatly exceed the thermal vibration amplitudes described by Debye-Waller factors and their measured dose rate dependence is attributed to tunable phonon contributions to the internal energy of the systems. Our experiments suggest operating electron microscopes with beam currents as small as zepto-amperes/nm2 in a weak-excitation approach to improve on sample integrity and allow for time-resolved studies of conformational object changes that probe for functional behavior of catalytic surfaces or molecules.

The Impact of Iron Adsorption on the Electronic and Photocatalytic Properties of the Zinc Oxide (0001) Surface: A First-Principles Study.

PubMed

Cheng, Jingsi; Wang, Ping; Hua, Chao; Yang, Yintang; Zhang, Zhiyong

2018-03-12

The structural stability, electronic structure, and optical properties of an iron-adsorbed ZnO (0001) surface with three high-symmetry adsorption sites are investigated with first-principle calculations on the basis of density functional theory and the Hubbard-U method. It is found that the iron adatom in the H₃ adsorption site of ZnO (0001) surface has the lowest adsorption energy of -5.665 eV compared with T₄ and Top sites. For the Top site, compared with the pristine ZnO (0001) surface, the absorption peak located at 1.17 eV has a red shift, and the elevation of the absorption coefficient is more pronounced in the visible-light region, because the Fe-related levels are introduced in the forbidden band and near the Fermi level. The electrostatic potential computation reveals that the work function of the ZnO (0001) surface is significantly decreased from 2.340 to 1.768 eV when iron is adsorbed on the Top site. Furthermore, the degradation mechanism based on the band structure is analyzed. It can be concluded that the adsorption of iron will promote the separation of photoinduced carriers, thus improving the photocatalytic activity of ZnO (0001) surface. Our study benefits research on the photocatalytic activity of ZnO and the utilization rate of solar energy.

Economic impact of V2G technology in a smart microgrid

NASA Astrophysics Data System (ADS)

Anastasiadis, Anestis G.; Polyzakis, Apostolos; Vokas, Georgios A.

2018-05-01

With serious concerns on global warming and energy crisis, there are plenty of motivations for developing and commercializing plug-in Electric Vehicles (EVs). It is believed that substitution of EVs for conventional fuel vehicles can help reduce the greenhouse gases emission, increase the energy efficiency, enhance the integration of renewable energy, and so forth. These advantages originate from the double role of the electrical vehicle's battery. Thus, it may constitute firstly a controllable load that we are able to optimally control at convenient time frames and secondly, it may store and inject energy, acting as a storage device. Nowadays, a number of EVs use power grids around the world to charge and discharge their batteries. Smart Microgrids (SMs) seem to be the best solution for the management of modern Low Voltage (LV) grids with Distributed Energy Resources (DER) and EVs. Among these technologies, EVs pose both a risk by increasing the peak load as well as an opportunity for the existing energy management systems by charging and discharging electricity with the help of Vehicle-to-Grid (V2G) technology. The key to the implementation of V2G is how to effectively integrate information into energy conversion, transmission and distribution. V2G should be carried out within the framework of SM, so that the status information of power grid can be perceived. In this paper, a Low Voltage (LV) SM derived from an interconnection bus is considered which is characterized by the presence of DERs units and EVs. Firstly, an overview of plug in EV technologies is examined and then the main purpose of the paper is to investigate the effects of V2G charging and discharging strategies in a SM. With EVs and absence of DERs is considered as the base case. For each scenario, two different charging technologies are examined (Dump Charging and V2G) in terms of operational cost. All data are taken from Hellenic Distribution/Transmission System Operators and Hellenic Operator of Electricity Market. Matlab software is used for all cases of studies.

Advancing electric-vehicle development with pure-lead-tin battery technology

NASA Astrophysics Data System (ADS)

O'Brien, W. A.; Stickel, R. B.; May, G. J.

Electric-vehicle (EV) development continues to make solid progress towards extending vehicle range, reliability and ease of use, aided significantly by technological advances in vehicle systems. There is, however, a widespread misconception that current battery technologies are not capable of meeting even the minimum user requirements that would launch EVs into daily use. Existing pure-lead-tin technology is moving EVs out of research laboratories and onto the streets, in daily side-by-side operation with vehicles powered by conventional gasoline and alternative fuels. This commercially available battery technology can provide traffic-compatible performance in a reliable and affordable manner, and can be used for either pure EVs or hybrid electric vehicles (HEVs). Independent results obtained when applying lead-tin batteries in highly abusive conditions, both electrically and environmentally, are presented. The test fleet of EVs is owned and operated by Arizona Public Service (APS), an electric utility in Phoenix, AZ, USA. System, charger and battery development will be described. This gives a single charge range of up to 184 km at a constant speed of 72 km h -1, and with suitable opportunity charging, a 320 km range in a normal 8 h working day.

A first principle study for the adsorption and absorption of carbon atom and the CO dissociation on Ir(100) surface

NASA Astrophysics Data System (ADS)

Erikat, I. A.; Hamad, B. A.

2013-11-01

We employ density functional theory to examine the adsorption and absorption of carbon atom as well as the dissociation of carbon monoxide on Ir(100) surface. We find that carbon atoms bind strongly with Ir(100) surface and prefer the high coordination hollow site for all coverages. In the case of 0.75 ML coverage of carbon, we obtain a bridging metal structure due to the balance between Ir-C and Ir-Ir interactions. In the subsurface region, the carbon atom prefers the octahedral site of Ir(100) surface. We find large diffusion barrier for carbon atom into Ir(100) surface (2.70 eV) due to the strong bonding between carbon atom and Ir(100) surface, whereas we find a very small segregation barrier (0.22 eV) from subsurface to the surface. The minimum energy path and energy barrier for the dissociation of CO on Ir(100) surface are obtained by using climbing image nudge elastic band. The energy barrier of CO dissociation on Ir(100) surface is found to be 3.01 eV, which is appreciably larger than the association energy (1.61 eV) of this molecule.

Effect of point defects on the electronic density states of SnC nanosheets: First-principles calculations

NASA Astrophysics Data System (ADS)

Majidi, Soleyman; Achour, Amine; Rai, D. P.; Nayebi, Payman; Solaymani, Shahram; Beryani Nezafat, Negin; Elahi, Seyed Mohammad

In this work, we investigated the electronic and structural properties of various defects including single Sn and C vacancies, double vacancy of the Sn and C atoms, anti-sites, position exchange and the Stone-Wales (SW) defects in SnC nanosheets by using density-functional theory (DFT). We found that various vacancy defects in the SnC monolayer can change the electronic and structural properties. Our results show that the SnC is an indirect band gap compound, with the band gap of 2.10 eV. The system turns into metal for both structure of the single Sn and C vacancies. However, for the double vacancy contained Sn and C atoms, the structure remains semiconductor with the direct band gap of 0.37 eV at the G point. We also found that for anti-site defects, the structure remains semiconductor and for the exchange defect, the structure becomes indirect semiconductor with the K-G point and the band gap of 0.74 eV. Finally, the structure of SW defect remains semiconductor with the direct band gap at K point with band gap of 0.54 eV.

Adsorption of CH4 on nitrogen- and boron-containing carbon models of coal predicted by density-functional theory

NASA Astrophysics Data System (ADS)

Liu, Xiao-Qiang; Xue, Ying; Tian, Zhi-Yue; Mo, Jing-Jing; Qiu, Nian-Xiang; Chu, Wei; Xie, He-Ping

2013-11-01

Graphene doped by nitrogen (N) and/or boron (B) is used to represent the surface models of coal with the structural heterogeneity. Through the density functional theory (DFT) calculations, the interactions between coalbed methane (CBM) and coal surfaces have been investigated. Several adsorption sites and orientations of methane (CH4) on graphenes were systematically considered. Our calculations predicted adsorption energies of CH4 on graphenes of up to -0.179 eV, with the strongest binding mode in which three hydrogen atoms of CH4 direct to graphene surface, observed for N-doped graphene, compared to the perfect (-0.154 eV), B-doped (-0.150 eV), and NB-doped graphenes (-0.170 eV). Doping N in graphene increases the adsorption energies of CH4, but slightly reduced binding is found when graphene is doped by B. Our results indicate that all of graphenes act as the role of a weak electron acceptor with respect to CH4. The interactions between CH4 and graphenes are the physical adsorption and slightly depend upon the adsorption sites on graphenes and the orientations of methane as well as the electronegativity of dopant atoms in graphene.

A first principle study for the adsorption and absorption of carbon atom and the CO dissociation on Ir(100) surface.

PubMed

Erikat, I A; Hamad, B A

2013-11-07

We employ density functional theory to examine the adsorption and absorption of carbon atom as well as the dissociation of carbon monoxide on Ir(100) surface. We find that carbon atoms bind strongly with Ir(100) surface and prefer the high coordination hollow site for all coverages. In the case of 0.75 ML coverage of carbon, we obtain a bridging metal structure due to the balance between Ir-C and Ir-Ir interactions. In the subsurface region, the carbon atom prefers the octahedral site of Ir(100) surface. We find large diffusion barrier for carbon atom into Ir(100) surface (2.70 eV) due to the strong bonding between carbon atom and Ir(100) surface, whereas we find a very small segregation barrier (0.22 eV) from subsurface to the surface. The minimum energy path and energy barrier for the dissociation of CO on Ir(100) surface are obtained by using climbing image nudge elastic band. The energy barrier of CO dissociation on Ir(100) surface is found to be 3.01 eV, which is appreciably larger than the association energy (1.61 eV) of this molecule.

Density functional theory studies of methyl dissociation on a Ni(111) surface in the presence of an external electric field.

PubMed

Che, Fanglin; Zhang, Renqin; Hensley, Alyssa J; Ha, Su; McEwen, Jean-Sabin

2014-02-14

To provide a basis for understanding the reactive processes on nickel surfaces at fuel cell anodes, we investigate the influence of an external electric field on the dehydrogenation of methyl species on a Ni(111) surface using density functional theory calculations. The structures, adsorption energies and reaction barriers for all methyl species dissociation on the Ni(111) surface are identified. Our results show that the presence of an external electric field does not affect the structures and favorable adsorption sites of the adsorbed species, but causes the adsorption energies of the CHx species at the stable site to fluctuate around 0.2 eV. Calculations give an energy barrier of 0.692 eV for CH3* → CH2* + H*, 0.323 eV for CH2* → CH* + H* and 1.373 eV for CH* → C* + H*. Finally, we conclude that the presence of a large positive electric field significantly increases the energy barrier of the CH* → C* + H* reaction more than the other two reactions, suggesting that the presence of pure C atoms on Ni(111) are impeded in the presence of an external positive electric field.

Modeling of life limiting phenomena in the discharge chamber of an electron bombardment ion thruster

NASA Technical Reports Server (NTRS)

Handoo, Arvind K.; Ray, Pradosh K.

1991-01-01

An experimental facility to study the low energy sputtering of metal surfaces with ions produced by an ion gun is described. The energy of the ions ranged from 10 to 500 eV. Cesium ions with energies from 100 to 500 eV were used initially to characterize the operation of the ion gun. Next, argon and xenon ions were used to measure the sputtering yields of cobalt (Co), Cadmium (Cd), and Chromium (Cr) at an operating temperature of 2x10(exp -5) Torr. The ion current ranged from 0.0135 micro-A at 500 eV. The targets were electroplated on a copper substrate. The surface density of the electroplated material was approx. 50 micro-g/sq cm. The sputtered atoms were collected on an aluminum foil surrounding the target. Radioactive tracers were used to measure the sputtering yields. The sputtering yields of Cr were found to be much higher than those of Co and Cd. The yields of Co and Cd were comparable, with Co providing the higher yields. Co and Cd targets were observed to sputter at energies as low as 10 eV for both argon and xenon ions. The Cr yields could not be measured below 20 eV for argon ions and 15 eV for xenon ions. On a linear scale the yield energy curves near the threshold energies exhibit a concave nature.

Design and operational experience of a microwave cavity axion detector for the 20 – 100 μ eV range

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

Al Kenany, S.; Anil, M. A.; Backes, K. M.

We describe a dark matter axion detector designed, constructed, and operated both as an innovation platform for new cavity and amplifier technologies and as a data pathfinder in the 5-25 GHz range (~20-100 eV). The platform is small but flexible to facilitate the development of new microwave cavity and amplifier concepts in an operational environment. The experiment has recently completed its first data production; it is the first microwave cavity axion search to deploy a Josephson parametric amplifier and a dilution refrigerator to achieve near-quantum limited performance.

Design and operational experience of a microwave cavity axion detector for the 20 – 100 μ eV range

DOE PAGES

Al Kenany, S.; Anil, M. A.; Backes, K. M.; ...

2017-02-09

We describe a dark matter axion detector designed, constructed, and operated both as an innovation platform for new cavity and amplifier technologies and as a data pathfinder in the 5-25 GHz range (~20-100 eV). The platform is small but flexible to facilitate the development of new microwave cavity and amplifier concepts in an operational environment. The experiment has recently completed its first data production; it is the first microwave cavity axion search to deploy a Josephson parametric amplifier and a dilution refrigerator to achieve near-quantum limited performance.

[Expression of EV71-VP1, PSGL-1 and SCARB2 in Tissues of Infants with Brain Stem Encephalitis].

PubMed

Li, Ming; Kong, Xiao-ping; Liu, Hong; Cheng, Ling-xi; Huang, Jing-lu; Quan, Li; Wu, Fang-yu; Hao, Bo; Liu, Chao; Luo, Bin

2015-04-01

To understand the correlation of enterovirus 71 (EV71), P-selectin glycoprotein ligand-1 (PSGL-1), and scavenger receptor B2 (SCARB2) and to explore the possible pathway and mechanism of EV71 infection by observing the expression of EV71, PSGL-1 and SCARB2 in tissues of infants with brain stem encephalitis. The organs and tissues of infants with EV71-VP1 positivity in their brain stems were chosen. Expression and distribution of EV71-VP1, PSGL-1, and SCARB2 were detected and compared by immunohistochemistry. Strong staining of EV71 -VP1 was observed in the neuron, glial cells, the inflammatory cells of perivascular cuffing, parietal cells of the gastric fundus gland while alveolar macrophages, intestinal gland epithelium cells, mucosa lymphoid nodule and lymphocyte of palatine tonsil showed moderate staining and weak staining were displayed in mesenteric lymph nodes and lymphocyte of spleen. PSGL-1 expression was detected in parietal cells of the gastric fundus gland, tonsillar crypt squamous epithelium, alveolar macrophages and leukocytes in each tissue. SCARB2 expression was observed in all the above tissues except the intestines and spleen. The distribution of EV71 correlates with SCARB2 expression. SCARB2 plays an important role in virus infection and replication. Stomach may be an important site for EV71 replication.

Apigenin Inhibits Enterovirus-71 Infection by Disrupting Viral RNA Association with trans-Acting Factors

PubMed Central

Zhang, Wei; Qiao, Haishi; Lv, Yuanzi; Wang, Jingjing; Chen, Xiaoqing; Hou, Yayi; Tan, Renxiang; Li, Erguang

2014-01-01

Flavonoids are widely distributed natural products with broad biological activities. Apigenin is a dietary flavonoid that has recently been demonstrated to interact with heterogeneous nuclear ribonucleoproteins (hnRNPs) and interferes with their RNA editing activity. We investigated whether apigenin possessed antiviral activity against enterovirus-71 (EV71) infection since EV71 infection requires of hnRNP proteins. We found that apigenin selectively blocks EV71 infection by disrupting viral RNA association with hnRNP A1 and A2 proteins. The estimated EC50 value for apigenin to block EV71 infection was determined at 10.3 µM, while the CC50 was estimated at 79.0 µM. The anti-EV71 activity was selective since no activity was detected against several DNA and RNA viruses. Although flavonoids in general share similar structural features, apigenin and kaempferol were among tested compounds with significant activity against EV71 infection. hnRNP proteins function as trans-acting factors regulating EV71 translation. We found that apigenin treatment did not affect EV71-induced nucleocytoplasmic redistribution of hnRNP A1 and A2 proteins. Instead, it prevented EV71 RNA association with hnRNP A1 and A2 proteins. Accordingly, suppression of hnRNP A1 and A2 expression markedly reduced EV71 infection. As a positive sense, single strand RNA virus, EV71 has a type I internal ribosome entry site (IRES) that cooperates with host factors and regulates EV71 translation. The effect of apigenin on EV71 infection was further demonstrated using a bicistronic vector that has the expression of a GFP protein under the control of EV71 5′-UTR. We found that apigenin treatment selectively suppressed the expression of GFP, but not a control gene. In addition to identification of apigenin as an antiviral agent against EV71 infection, this study also exemplifies the significance in antiviral agent discovery by targeting host factors essential for viral replication. PMID:25330384

[Genetic evidence for recombination and mutation in the emergence of human enterovirus 71].

PubMed

Liu, Ai-Ping; Tan, Hui; Xie, Qun; Chen, Bai-Tang; Liu, Xiao-Feng; Zhang, Yong

2014-09-01

We wished to understand the genetic recombination and phylogenetic characteristics of human en- terovirus A71 (EV-A71) and to explore its potential virulence-related sites. Full-length genomes of three EV-A71 strains isolated from patients in Chenzhou City (China) were sequenced and analyzed. Possible re- combination events and crossover sites were analyzed with Recombination Detection Program v4. 1. 6 by comparison with the complete genome sequences of 231 strains of EV-A71. Similarly, plot and bootscanning analyses were undertaken with SimPlot v3. 5. 1. Phylogenetic trees based on the sequences of VP1 regions were constructed with MEGA v5. 2 using the Kimura two-parameter model and neighbor-joining method. Results suggested that recombination events were detected among the three EV-A71 isolates from Chenzhou City. The common main parent sequence was from JF799986 isolated from samples in Guang- zhou City (China) in 2009, and the minor parent sequence was TW/70516/08. Intertypic recombination e- vents were found in the C4b strain (strain SHZH98 isolated in 1998) and C4a strain (Fuyang strain isola- ted in 2008) with the prototype strains of CVA4 and CVA14 in the 3D region. The chi-square test was used to screen-out potential virulence-related sites with nucleotide substitutions of different types of hand, foot, and mouth disease (HFMD) cases using SPSS v19.0. Results suggested that there were no significant nucleotide substitutions between death cases and severe-HFMD cases. Eighteen significant nucleotide substitutions were found between death/severe-HFMD cases and mild-HFMD cases, and all these 18 substitutions were distributed only in P2 and P3 regions. Intertypic recombination among the predominant circulating EV-A71 strains in the Chinese mainland and other EV-A strains probably dates before 1998, and intratypic recombination might have occurred frequently in the HFMD outbreak from 2008 to 2012. Substitutions in the non-capsid region may be correlated with the changes in virulence of EV-A71. These data suggest that researchers should pay more attention to the relationships between substitutions in the noncapsid region and the virulence of the virus.

Lattice sites of ion-implanted Mn, Fe and Ni in 6H-SiC

NASA Astrophysics Data System (ADS)

Costa, A. R. G.; Wahl, U.; Correia, J. G.; David-Bosne, E.; Amorim, L. M.; Augustyns, V.; Silva, D. J.; da Silva, M. R.; Pereira, L. M. C.

2018-01-01

Using radioactive isotopes produced at the CERN-ISOLDE facility, the lattice location of the implanted transition metal (TM) ions 56Mn, 59Fe and 65Ni in n-type single-crystalline hexagonal 6H-SiC was studied by means of the emission channeling technique. TM probes on carbon coordinated tetrahedral interstitial sites (T C) and on substitutional silicon sites (S Si,h+k ) were identified. We tested for but found no indication that the TM distribution on S Si sites deviates from the statistical mixture of 1/3 hexagonal and 2/3 cubic sites present in the 6H crystal. The TM atoms partially disappear from T C positions during annealing at temperatures between 500 °C and 700 °C which is accompanied by an increase on S Si and random sites. From the temperature associated with these site changes, interstitial migration energies of 1.7-2.7 eV for Mn and Ni, and 2.3-3.2 eV for Fe were estimated. TM lattice locations are compared to previous results obtained in 3C-SiC using the same technique.

Straight and chopped DC performance data for a General Electric 5BY436A1 DC shunt motor with a General Electric EV-1 controller

NASA Technical Reports Server (NTRS)

Edie, P. C.

1981-01-01

Both straight and chopped dc motor performance data for a General Electric 5BY436A1 motor with a General Electric EV-1 controller is presented in tabular and graphical formats. Effects of motor temperature and operating voltage are also shown. The maximum motor efficiency is approximately 85% at low operating temperatures in the straight dc mode. Chopper efficiency can be assumed to be 95% under all operating conditions. For equal speeds, the motor operated in the chopped mode develops slightly more torque and draws more current than it does in the straight mode.

E-Marketing: Are Community Colleges Embracing the Web?

ERIC Educational Resources Information Center

Clagett, Craig

2001-01-01

Conducted a pilot survey of community colleges to assess their online marketing efforts. Found that while all had Web sites, only a minority of sites were truly interactive. Involvement of marketing offices with Web sites varied considerably, and a minority had used e-mail or Web ads for marketing. (EV)

EV, Microvesicles/MicroRNAs and Stem Cells in Cancer.

PubMed

Tickner, Jacob A; Richard, Derek J; O'Byrne, Kenneth J

2018-01-01

The role of extracellular vesicles (EV) in carcinogenesis has become the focus of much research. These microscopic messengers have been found to regulate immune system function, particularly in tumorigenesis, as well as conditioning future metastatic sites for the attachment and growth of tumor tissue. Through an interaction with a range of host tissues, EVs are able to generate a pro-tumor environment that is essential for tumorigenesis. These small nanovesicles are an ideal candidate for a non-invasive indicator of pathogenesis and/or disease progression as they can display individualized nucleic acid, protein, and lipid expression profiles that are often reflective of disease state, and can be easily detected in bodily fluids, even after extended cryo-storage. Furthermore, the ability of EVs to securely transport signaling molecules and localize to distant tissues suggests these particles may greatly improve the delivery of therapeutic treatments, particularly in cancer. In this chapter, we discuss the role of EV in the identification of new diagnostic and prognostic cancer biomarkers, as well as the development of novel EV-based cancer therapies.

Band alignment at β-(AlxGa1-x)2O3/β-Ga2O3 (100) interface fabricated by pulsed-laser deposition

NASA Astrophysics Data System (ADS)

Wakabayashi, Ryo; Hattori, Mai; Yoshimatsu, Kohei; Horiba, Koji; Kumigashira, Hiroshi; Ohtomo, Akira

2018-06-01

High-quality β-(AlxGa1-x)2O3 (x = 0-0.37) films were epitaxially grown on β-Ga2O3 (100) substrates by oxygen-radical-assisted pulsed-laser deposition with repeating alternate ablation of single crystals of β-Ga2O3 and α-Al2O3. The bandgap was tuned from 4.55 ± 0.01 eV (x = 0) to 5.20 ± 0.02 eV (x = 0.37), where bowing behavior was observed. The band alignment at the β-(AlxGa1-x)2O3/β-Ga2O3 interfaces was found to be type-I with conduction- and valence-band offsets of 0.52 ± 0.08 eV (0.37 ± 0.08 eV) and 0.13 ± 0.07 eV (0.02 ± 0.07 eV) for x = 0.37 (0.27), respectively. The large conduction-band offsets are ascribed to the dominant contribution of the cation-site substitution to the conduction band.

Frequency Control Using On line Learning Method for Island Smart Grid with EVs and PVs

DTIC Science & Technology

2014-07-06

deviation from PVs are modeled as the power disturbance for the system . A. Case 1: active power disturbance without EVs constraints In this case, there are...IEEE Transactions on, vol. 3, no. 1, pp. 565–577, 2012. [7] M. Datta and T. Senjyu, “Fuzzy control of distributed pv inverters /energy storage systems ...this linearity assumption. In island smart grid with photovoltaics ( PVs ) and EVs, system state parameters and operating conditions are changing

High-intensity xenon plasma discharge lamp for bulk-sensitive high-resolution photoemission spectroscopy.

PubMed

Souma, S; Sato, T; Takahashi, T; Baltzer, P

2007-12-01

We have developed a highly brilliant xenon (Xe) discharge lamp operated by microwave-induced electron cyclotron resonance (ECR) for ultrahigh-resolution bulk-sensitive photoemission spectroscopy (PES). We observed at least eight strong radiation lines from neutral or singly ionized Xe atoms in the energy region of 8.4-10.7 eV. The photon flux of the strongest Xe I resonance line at 8.437 eV is comparable to that of the He Ialpha line (21.218 eV) from the He-ECR discharge lamp. Stable operation for more than 300 h is achieved by efficient air-cooling of a ceramic tube in the resonance cavity. The high bulk sensitivity and high-energy resolution of PES using the Xe lines are demonstrated for some typical materials.

An EAS experiment at mountain altitude for the detection of gamma-ray sources

NASA Technical Reports Server (NTRS)

Allkofer, O. C.; Samorski, M.; Stamm, W.

1985-01-01

The plan of an extensive air shower experiment 2.200 m above sea level for the detection of 10 to the 14th power eV to 10 to the 17th power eV gamma rays from sources in the declination band 0 deg to + 60 deg is described. The site selection, detector array and electronic layout are detailed.

Geographical and temporal differences in electric vehicle range due to cabin conditioning energy consumption

NASA Astrophysics Data System (ADS)

Kambly, Kiran; Bradley, Thomas H.

2015-02-01

Electric vehicles (EVs) are vehicles that are propelled by electric motors powered by rechargeable battery. They are generally asserted to have GHG emissions, driveability and life cycle cost benefits over conventional vehicles. Despite this, EVs face significant challenges due to their limited on-board energy storage capacity. In addition to providing energy for traction, the energy storage device operates HVAC systems for cabin conditioning. This results in reduced driving range. The factors such as local ambient temperature, local solar radiation, local humidity, duration and thermal soak have been identified to affect the cabin conditions. In this paper, the development of a detailed system-level approach to HVAC energy consumption in EVs as a function of transient environmental parameters is described. The resulting vehicle thermal comfort model is used to address several questions such as 1) How does day to day environmental conditions affect EV range? 2) How does frequency of EV range change geographically? 3) How does trip start time affect EV range? 4) Under what conditions does cabin preconditioning assist in increasing the EV range? 5) What percentage increase in EV range can be expected due to cabin preconditioning at a given location?

CD30 on extracellular vesicles from malignant Hodgkin cells supports damaging of CD30 ligand-expressing bystander cells with Brentuximab-Vedotin, in vitro

PubMed Central

Hansen, Hinrich P.; Trad, Ahmad; Dams, Maria; Zigrino, Paola; Moss, Marcia; Tator, Maximilian; Schön, Gisela; Grenzi, Patricia C; Bachurski, Daniel; Aquino, Bruno; Dürkop, Horst; Reiners, Katrin S; von Bergwelt-Baildon, Michael; Hallek, Michael; Grötzinger, Joachim; Engert, Andreas; Leme, Adriana F Paes; von Strandmann, Elke Pogge

2016-01-01

The goal of targeted immunotherapy in cancer is to damage both malignant and tumor-supporting cells of the microenvironment but spare unaffected tissue. The malignant cells in classical Hodgkin lymphoma (cHL) selectively express CD30. They release this receptor on extracellular vesicles (EVs) for the tumor-supporting communication with CD30 ligand (CD30L)-positive bystander cells. Here, we investigated how CD30-positive EVs influence the efficacy of the CD30 antibody drug conjugate (ADC) Brentuximab Vedotin (SGN-35). The malignant cells and the EVs expressed the active sheddase ADAM10. ADAM10 cleaved and released the CD30 ectodomain (sCD30), causing a gradual depletion of SGN-35 binding sites on EVs and creating a soluble competitor of the ADC therapy. In a 3D semi-solid tumor microenvironment model, the EVs were retained in the matrix whereas sCD30 penetrated readily into the surrounding culture medium. This resulted in a lowered ratio of EV-associated CD30 (CD30EV) to sCD30 in the surrounding medium in comparison to non-embedded cultures. A low percentage of CD30EV was also detected in the plasma of cHL patients, supporting the clinical relevance of the model. The adherence of CD30EV but not sCD30 to CD30−/CD30L+ mast cells and eosinophils allowed the indirect binding of SGN-35. Moreover, SGN-35 damaged CD30-negative cells, provided they were loaded with CD30+ EVs. PMID:27105521

Antiviral effects of two Ganoderma lucidum triterpenoids against enterovirus 71 infection

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

Zhang, Wenjing; Tao, Junyan; Yang, Xiaoping

Highlights: • Triterpenoids GLTA and GLTB display anti-EV71 activities without cytotoxicity. • The compounds prevent EV71 infection by blocking adsorption of the virus to the cells. • GLTA and GLTB bind to EV71 capsid at the hydrophobic pocket to block EV71 uncoating. • The two compounds significantly inhibit the replication of EV71 viral RNA. • GLTA and GLTB may be used as potential therapeutic agents to treat EV71 infection. - Abstract: Enterovirus 71 (EV71) is a major causative agent for hand, foot and mouth disease (HFMD), and fatal neurological and systemic complications in children. However, there is currently no clinicalmore » approved antiviral drug available for the prevention and treatment of the viral infection. Here, we evaluated the antiviral activities of two Ganoderma lucidum triterpenoids (GLTs), Lanosta-7,9(11),24-trien-3-one,15;26-dihydroxy (GLTA) and Ganoderic acid Y (GLTB), against EV71 infection. The results showed that the two natural compounds display significant anti-EV71 activities without cytotoxicity in human rhabdomyosarcoma (RD) cells as evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell proliferation assay. The mechanisms by which the two compounds affect EV71 infection were further elucidated by three action modes using Ribavirin, a common antiviral drug, as a positive control. The results suggested that GLTA and GLTB prevent EV71 infection through interacting with the viral particle to block the adsorption of virus to the cells. In addition, the interactions between EV71 virion and the compounds were predicated by computer molecular docking, which illustrated that GLTA and GLTB may bind to the viral capsid protein at a hydrophobic pocket (F site), and thus may block uncoating of EV71. Moreover, we demonstrated that GLTA and GLTB significantly inhibit the replication of the viral RNA (vRNA) of EV71 replication through blocking EV71 uncoating. Thus, GLTA and GLTB may represent two potential therapeutic agents to control and treat EV71 infection.« less

Extracellular vesicles have variable dose-dependent effects on cultured draining cells in the eye.

PubMed

Tabak, Saray; Schreiber-Avissar, Sofia; Beit-Yannai, Elie

2018-03-01

The role of extracellular vesicles (EVs) as signal mediators has been described in many biological fields. How many EVs are needed to deliver the desired physiological signal is yet unclear. Using a normal trabecular meshwork (NTM) cell culture exposed to non-pigmented ciliary epithelium (NPCE)-derived EVs, a relevant model for studying the human ocular drainage system, we addressed the EVs dose-response effects on the Wnt signaling. The objective of the study was to investigate the dosing effects of NPCE-derived EVs on TM Wnt signaling. EVs were isolated by PEG 8000 method from NPCE and RPE cells (used as controls) conditioned media. Concentrations were determined by Tunable Resistive Pulse Sensing method. Various exosomes concentration were incubated with TM cells, for the determination of mRNA (β-Catenin, Axin2 and LEF1) and protein (β-Catenin, GSK-3β) expression using real-time quantitative PCR and Western blot, respectively. Exposure of NTM cells for 8 hrs to low EVs concentrations was associated with a significant decreased expression of β-Catenin, GSK-3β, as opposed to exposure to high exosomal concentrations. Pro-MMP9 and MMP9 activities were significantly enhanced in NTM cells treated with high EV concentrations of (X10) as compared to low EV concentrations of either NPCE- or RPE-derived EVs and to untreated control. Our data support the concept that EVs biological effects are concentration-dependent at their target site. Specifically in the present study, we described a general dose-response at the gene and MMPs activity and a different dose-response regarding key canonical Wnt proteins expression. © 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Spitting out the demons: Extracellular vesicles in glioblastoma.

PubMed

André-Grégoire, Gwennan; Gavard, Julie

2017-03-04

Discovered decades ago, extracellular vesicles (EVs) emerge as dedicated organelles, able to deliver protected, specific cellular cues throughout the organism. While virtually every cell can release EVs, cancer cells co-opted this feature and efficiently unleashed them both in the tumor microenvironment and toward healthy tissues. This might contribute to tumor aggressiveness and spreading. Cancer-derived EVs that contain DNA, mRNA, miRNA, and packed and transmembrane proteins can operate locally or at distance. This review will focus on the high-grade brain tumor (i.e. glioblastoma)-derived EVs, discussing recent reports on i) their phenotype and content, ii) their putative functions, and iii) their clinical potential for improving diagnosis and therapeutics.

A multi-factor GIS method to identify optimal geographic locations for electric vehicle (EV) charging stations

NASA Astrophysics Data System (ADS)

Zhang, Yongqin; Iman, Kory

2018-05-01

Fuel-based transportation is one of the major contributors to poor air quality in the United States. Electric Vehicle (EV) is potentially the cleanest transportation technology to our environment. This research developed a spatial suitability model to identify optimal geographic locations for installing EV charging stations for travelling public. The model takes into account a variety of positive and negative factors to identify prime locations for installing EV charging stations in Wasatch Front, Utah, where automobile emission causes severe air pollution due to atmospheric inversion condition near the valley floor. A walkable factor grid was created to store index scores from input factor layers to determine prime locations. 27 input factors including land use, demographics, employment centers etc. were analyzed. Each factor layer was analyzed to produce a summary statistic table to determine the site suitability. Potential locations that exhibit high EV charging usage were identified and scored. A hot spot map was created to demonstrate high, moderate, and low suitability areas for installing EV charging stations. A spatially well distributed EV charging system was then developed, aiming to reduce "range anxiety" from traveling public. This spatial methodology addresses the complex problem of locating and establishing a robust EV charging station infrastructure for decision makers to build a clean transportation infrastructure, and eventually improve environment pollution.

The added economic and environmental value of plug-in electric vehicles connected to commercial building microgrids

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

Stadler, Michael; Momber, Ilan; Megel, Olivier

2010-08-25

Connection of electric storage technologies to smartgrids or microgrids will have substantial implications for building energy systems. In addition to potentially supplying ancillary services directly to the traditional centralized grid (or macrogrid), local storage will enable demand response. As an economically attractive option, mobile storage devices such as plug-in electric vehicles (EVs) are in direct competition with conventional stationary sources and storage at the building. In general, it is assumed that they can improve the financial as well as environmental attractiveness of renewable and fossil based on-site generation (e.g. PV, fuel cells, or microturbines operating with or without combined heatmore » and power). Also, mobile storage can directly contribute to tariff driven demand response in commercial buildings. In order to examine the impact of mobile storage on building energy costs and carbon dioxide (CO2) emissions, a microgrid/distributed-energy-resources (DER) adoption problem is formulated as a mixed-integer linear program with minimization of annual building energy costs applying CO2 taxes/CO2 pricing schemes. The problem is solved for a representative office building in the San Francisco Bay Area in 2020. By using employees' EVs for energy management, the office building can arbitrage its costs. But since the car battery lifetime is reduced, a business model that also reimburses car owners for the degradation will be required. In general, the link between a microgrid and an electric vehicle can create a win-win situation, wherein the microgrid can reduce utility costs by load shifting while the electric vehicle owner receives revenue that partially offsets his/her expensive mobile storage investment. For the California office building with EVs connected under a business model that distributes benefits, it is found that the economic impact is very limited relative to the costs of mobile storage for the site analyzed, i.e. cost reductions from electric vehicle connections are modest. Nonetheless, this example shows that some economic benefit is created because of avoided demand charges and on-peak energy. The strategy adopted by the office building is to avoid these high on-peak costs by using energy from the mobile storage in the business hours. CO2 emission reduction strategy results indicate that EVs' contribution at the selected office building are minor.« less

Identification of Site-Specific Adaptations Conferring Increased Neural Cell Tropism during Human Enterovirus 71 Infection

PubMed Central

Schibler, Manuel; Martinez, Yannick; Gerlach, Daniel; van Belle, Sandra; Turin, Lara; Zdobnov, Evgeny; Kaiser, Laurent; Tapparel, Caroline

2012-01-01

Enterovirus 71 (EV71) is one of the most virulent enteroviruses, but the specific molecular features that enhance its ability to disseminate in humans remain unknown. We analyzed the genomic features of EV71 in an immunocompromised host with disseminated disease according to the different sites of infection. Comparison of five full-length genomes sequenced directly from respiratory, gastrointestinal, nervous system, and blood specimens revealed three nucleotide changes that occurred within a five-day period: a non-conservative amino acid change in VP1 located within the BC loop (L97R), a region considered as an immunogenic site and possibly important in poliovirus host adaptation; a conservative amino acid substitution in protein 2B (A38V); and a silent mutation in protein 3D (L175). Infectious clones were constructed using both BrCr (lineage A) and the clinical strain (lineage C) backgrounds containing either one or both non-synonymous mutations. In vitro cell tropism and competition assays revealed that the VP197 Leu to Arg substitution within the BC loop conferred a replicative advantage in SH-SY5Y cells of neuroblastoma origin. Interestingly, this mutation was frequently associated in vitro with a second non-conservative mutation (E167G or E167A) in the VP1 EF loop in neuroblastoma cells. Comparative models of these EV71 VP1 variants were built to determine how the substitutions might affect VP1 structure and/or interactions with host cells and suggest that, while no significant structural changes were observed, the substitutions may alter interactions with host cell receptors. Taken together, our results show that the VP1 BC loop region of EV71 plays a critical role in cell tropism independent of EV71 lineage and, thus, may have contributed to dissemination and neurotropism in the immunocompromised patient. PMID:22910880

Genetic diversity and recombination of enterovirus G strains in Japanese pigs: High prevalence of strains carrying a papain-like cysteine protease sequence in the enterovirus G population.

PubMed

Tsuchiaka, Shinobu; Naoi, Yuki; Imai, Ryo; Masuda, Tsuneyuki; Ito, Mika; Akagami, Masataka; Ouchi, Yoshinao; Ishii, Kazuo; Sakaguchi, Shoichi; Omatsu, Tsutomu; Katayama, Yukie; Oba, Mami; Shirai, Junsuke; Satani, Yuki; Takashima, Yasuhiro; Taniguchi, Yuji; Takasu, Masaki; Madarame, Hiroo; Sunaga, Fujiko; Aoki, Hiroshi; Makino, Shinji; Mizutani, Tetsuya; Nagai, Makoto

2018-01-01

To study the genetic diversity of enterovirus G (EV-G) among Japanese pigs, metagenomics sequencing was performed on fecal samples from pigs with or without diarrhea, collected between 2014 and 2016. Fifty-nine EV-G sequences, which were >5,000 nucleotides long, were obtained. By complete VP1 sequence analysis, Japanese EV-G isolates were classified into G1 (17 strains), G2 (four strains), G3 (22 strains), G4 (two strains), G6 (two strains), G9 (six strains), G10 (five strains), and a new genotype (one strain). Remarkably, 16 G1 and one G2 strain identified in diarrheic (23.5%; four strains) or normal (76.5%; 13 strains) fecal samples possessed a papain-like cysteine protease (PL-CP) sequence, which was recently found in the USA and Belgium in the EV-G genome, at the 2C-3A junction site. This paper presents the first report of the high prevalence of viruses carrying PL-CP in the EV-G population. Furthermore, possible inter- and intragenotype recombination events were found among EV-G strains, including G1-PL-CP strains. Our findings may advance the understanding of the molecular epidemiology and genetic evolution of EV-Gs.

Electric vehicle energy management system

NASA Astrophysics Data System (ADS)

Alaoui, Chakib

This thesis investigates and analyzes novel strategies for the optimum energy management of electric vehicles (EVs). These are aimed to maximize the useful life of the EV batteries and make the EV more practical in order to increase its acceptability to market. The first strategy concerns the right choice of the batteries for the EV according to the user's driving habits, which may vary. Tests conducted at the University of Massachusetts Lowell battery lab show that the batteries perform differently from one manufacturer to the other. The second strategy was to investigate the fast chargeability of different batteries, which leads to reduce the time needed to recharge the EV battery pack. Tests were conducted again to prove that only few battery types could be fast charged. Test data were used to design a fast battery charger that could be installed in an EV charging station. The third strategy was the design, fabrication and application of an Electric Vehicle Diagnostic and Rejuvenation System (EVDRS). This system is based on Mosfet Controlled Thyristors (MCTs). It is capable of quickly identifying any failing battery(s) within the EV pack and rejuvenating the whole battery pack without dismantling them and unloading them. A novel algorithm to rejuvenate Electric Vehicle Sealed Lead Acid Batteries is described. This rejuvenation extends the useful life of the batteries and makes the EV more competitive. The fourth strategy was to design a thermal management system for EV, which is crucial to the safe operation, and the achievement of normal/optimal performance of, electric vehicle (EV) batteries. A novel approach for EV thermal management, based on Pettier-Effect heat pumps, was designed, fabricated and tested in EV. It shows the application of this type of technology for thermal management of EVs.

Delta-doped hybrid advanced detector for low energy particle detection

NASA Technical Reports Server (NTRS)

Cunningham, Thomas J. (Inventor); Fossum, Eric R. (Inventor); Nikzad, Shouleh (Inventor); Pain, Bedabrata (Inventor); Soli, George A. (Inventor)

2000-01-01

A delta-doped hybrid advanced detector (HAD) is provided which combines at least four types of technologies to create a detector for energetic particles ranging in energy from hundreds of electron volts (eV) to beyond several million eV. The detector is sensitive to photons from visible light to X-rays. The detector is highly energy-sensitive from approximately 10 keV down to hundreds of eV. The detector operates with milliwatt power dissipation, and allows non-sequential readout of the array, enabling various advanced readout schemes.

Delta-doped hybrid advanced detector for low energy particle detection

NASA Technical Reports Server (NTRS)

Cunningham, Thomas J. (Inventor); Fossum, Eric R. (Inventor); Nikzad, Shouleh (Inventor); Pain, Bedabrata (Inventor); Soli, George A. (Inventor)

2002-01-01

A delta-doped hybrid advanced detector (HAD) is provided which combines at least four types of technologies to create a detector for energetic particles ranging in energy from hundreds of electron volts (eV) to beyond several million eV. The detector is sensitive to photons from visible light to X-rays. The detector is highly energy-sensitive from approximately 10 keV down to hundreds of eV. The detector operates with milliwatt power dissipation, and allows non-sequential readout of the array, enabling various advanced readout schemes.

In-situ, Gate Bias Dependent Study of Neutron Irradiation Effects on AlGaN/GaN HFETs

DTIC Science & Technology

2010-03-01

band gap and high breakdown field, AlGaN devices can operate at very high temperature and operating frequency. AlGaN/GaN based structures, have been...stable under ambient conditions [3]. GaN has a wide, direct band gap of 3.4 eV. It is therefore suitable for high temperature devices. Its high...also be grown with a wurtzite crystal structure and has a band - gap of 6.1 eV. Aluminum, due to having smaller atoms than gallium, forms a smaller

Electronic structure of Mott-insulator CaCu3Ti4O12: Photoemission and inverse photoemission study

NASA Astrophysics Data System (ADS)

Im, H. J.; Iwataki, M.; Yamazaki, S.; Usui, T.; Adachi, S.; Tsunekawa, M.; Watanabe, T.; Takegahara, K.; Kimura, S.; Matsunami, M.; Sato, H.; Namatame, H.; Taniguchi, M.

2015-09-01

We have performed the photoemission and inverse photoemission experiments to elucidate the origin of Mott insulating states in A-site ordered perovskite CaCu3Ti4O12 (CCTO). Experimental results have revealed that Cu 3d-O 2p hybridized bands, which are located around the Fermi level in the prediction of the local-density approximation (LDA) band calculations, are actually separated into the upper Hubbard band at ~1.5 eV and the lower Hubbard band at ~-1.7 eV with a band gap of ~1.5-1.8 eV. We also observed that Cu 3d peak at ~-3.8 eV and Ti 3d peak at ~3.8 eV are further away from each other than as indicated in the LDA calculations. In addition, it is found that the multiplet structure around -9 eV includes a considerable number of O 2p states. These observations indicate that the Cu 3d and Ti 3d electrons hybridized with the O 2p states are strongly correlated, which originates in the Mott-insulating states of CCTO.

Losses in chopper-controlled DC series motors

NASA Technical Reports Server (NTRS)

Hamilton, H. B.

1982-01-01

Motors for electric vehicle (EV) applications must have different features than dc motors designed for industrial applications. The EV motor application is characterized by the following requirements: (1) the need for highest possible efficiency from light load to overload, for maximum EV range, (2) large short time overload capability (The ratio of peak to average power varies from 5/1 in heavy city traffic to 3/1 in suburban driving situations) and (3) operation from power supply voltage levels of 84 to 144 volts (probably 120 volts maximum). A test facility utilizing a dc generator as a substitute for a battery pack was designed and utilized. Criteria for the design of such a facility are presented. Two motors, differing in design detail, commercially available for EV use were tested. Losses measured are discussed, as are waves forms and their harmonic content, the measurements of resistance and inductance, EV motor/chopper application criteria, and motor design considerations.

Immunodominant IgM and IgG Epitopes Recognized by Antibodies Induced in Enterovirus A71-Associated Hand, Foot and Mouth Disease Patients

PubMed Central

Aw-Yong, Kam Leng; Sam, I-Ching; Koh, Mia Tuang

2016-01-01

Enterovirus A71 (EV-A71) is one of the main causative agents of hand, foot and mouth disease (HFMD). Unlike other enteroviruses that cause HFMD, EV-A71 is more frequently associated with severe neurological complications and fatality. To date, no effective licensed antivirals are available to combat EV-A71 infection. Little is known about the immunogenicity of viral non-structural proteins in humans. Previous studies have mainly focused on characterization of epitopes of EV-A71 structural proteins by using immunized animal antisera. In this study, we have characterized human antibody responses against the structural and non-structural proteins of EV-A71. Each viral protein was cloned and expressed in either bacterial or mammalian systems, and tested with antisera by western blot. Results revealed that all structural proteins (VP1-4), and non-structural proteins 2A, 3C and 3D were targets of EV-A71 IgM, whereas EV-A71 IgG recognized all the structural and non-structural proteins. Sixty three synthetic peptides predicted to be immunogenic in silico were synthesized and used for the characterization of EV-A71 linear B-cell epitopes. In total, we identified 22 IgM and four IgG dominant epitopes. Synthetic peptide PEP27, corresponding to residues 142–156 of VP1, was identified as the EV-A71 IgM-specific immunodominant epitope. PEP23, mapped to VP1 41–55, was recognized as the EV-A71 IgG cross-reactive immunodominant epitope. The structural protein VP1 is the major immunodominant site targeted by anti-EV-A71 IgM and IgG antibodies, but epitopes against non-structural proteins were also detected. These data provide new understanding of the immune response to EV-A71 infection, which benefits the development of diagnostic tools, potential therapeutics and subunit vaccine candidates. PMID:27806091

Preferential heating of light ions during an ionospheric Ar(+) injection experiment

NASA Technical Reports Server (NTRS)

Pollock, C. J.; Chandler, M. O.; Moore, T. E.; Arnoldy, R. L.; Kintner, P. M.; Chesney, S.; Cahill, L. J., Jr.

1995-01-01

The Argon Release for Controlled Studies (ARCS) 4 sounding rocket was launched northward into high altitude from Poker Flat Research Range on February 23, 1990. The vehicle crossed geomagnetic field lines containing discrete auroral activity. An instrumented subpayload released 100-eV and 200-eV Ar(+) ion beams sequentially, in a direction largely perpendicular to both the local geomagnetic field and the subpayload spin axis. The instrumented main payload was separated along field lines from the beam emitting subpayload by a distance which increased at a steady rate of approximately 2.4 m/s. Three dimensional mass spectrometric ion observations of ambient H(+) and O(+) ions, obtained on board the main payload, are presented. Main payload electric field observations in the frequency range 0-16 kHz, are also presented. These observations are presented to demonstrate the operation of transverse ion acceleration, which was differential with respect to ion mass, primarily during 100-eV beam operations. The preferential transverse acceleration of ambient H(+) ions, as compared with ambient O(+) ions, during the second, third, fourth, and fifth 100-eV beam operations, is attributed to a resonance among the injected Ar(+) ions, beam-generated lower hybrid waves, and H(+) ions in the tail of the ambient thermal distribution. This work provides experimental support of processes predicted by previously published theory and simulations.

UHM/HNEI EV test and evaluation program

NASA Astrophysics Data System (ADS)

1992-03-01

The electric vehicle (EV) program of the Hawaii Natural Energy Institute (HNEI) focuses primarily on the field testing of promising EV/traction batteries. The intent is to utilize typical driving cycles to develop information that verifies or refutes what is obtained in the laboratory. Three different types of batteries were assigned by the U.S. DOE for testing in this program: Sonnenschein Dryfit 6V-160, Exide GC-5, Trojan T-145. We added the following battery to the test program: ALCO2200. The following EVs were chosen in our program: Converted Ford Escort station wagon, Converted Ford Escort two-door sedan, Converted Ford Escort two-door sedan, Converted Dodge van. Based on capacity tests, corrective action such as battery replacement, additional charging, adjusting terminal connections, etc., may be taken to maintain good performance. About 15,500 miles and 600 cycles have been accumulated on the Sonnenschein Dryfit 6V-160 battery pack. Five of its 18 modules have been changed. Based on DOE's standard, the battery has reached the end of its useful life. Nevertheless, the battery pack is still operational and its operating range is still greater than 40 miles per charge. It is too early to evaluate the life expectancy of the other three batteries. No module has been replaced in these three packs. HNEI will keep the Trojan and Exide battery packs in operation. The Alco 2200 batteries will be transferred to another vehicle.

Probe-Hole Field Emission Microscope System Controlled by Computer

NASA Astrophysics Data System (ADS)

Gong, Yunming; Zeng, Haishan

1991-09-01

A probe-hole field emission microscope system, controlled by an Apple II computer, has been developed and operated successfully for measuring the work function of a single crystal plane. The work functions on the clean W(100) and W(111) planes are measured to be 4.67 eV and 4.45 eV, respectively.

Electric vehicles batteries thermal management systems employing phase change materials

NASA Astrophysics Data System (ADS)

Ianniciello, Lucia; Biwolé, Pascal Henry; Achard, Patrick

2018-02-01

Battery thermal management is necessary for electric vehicles (EVs), especially for Li-ion batteries, due to the heat dissipation effects on those batteries. Usually, air or coolant circuits are employed as thermal management systems in Li-ion batteries. However, those systems are expensive in terms of investment and operating costs. Phase change materials (PCMs) may represent an alternative which could be cheaper and easier to operate. In fact, PCMs can be used as passive or semi-passive systems, enabling the global system to sustain near-autonomous operations. This article presents the previous developments introducing PCMs for EVs battery cooling. Different systems are reviewed and solutions are proposed to enhance PCMs efficiency in those systems.

Prospects and limitations for p-type doping in boron nitride polymorphs

NASA Astrophysics Data System (ADS)

Weston, Leigh; van de Walle, Chris G.

Using first-principles calculations, we examine the potential for p-type doping of BN polymorphs via substitutional impurities. Based on density functional theory with a hybrid functional, our calculations reveal that group-IV elements (C, Si) substituting at the N site result in acceptor levels that are more than 1 eV above the valence-band maximum in all of the BN polymorphs, and hence far too deep to allow for p-type doping. On the other hand, group-II elements (Be, Mg) substituting at the B site lead to shallower acceptor levels. However, for the ground-state hexagonal phase (h-BN), we show that p-type doping at the B site is inhibited by the formation of hole polarons. Our calculations reveal that hole localization is intrinsic to sp2 bonded h-BN, and this places fundamental limits on hole conduction in this material. In contrast, the sp3 bonded wurtzite (w-BN) and cubic (c-BN) polymorphs are capable of forming shallow acceptor levels. For Be dopants, the acceptor ionization energies are 0.31 eV and 0.24 eV for w-BN and c-BN, respectively; these values are only slightly larger than the ionization energy of the Mg acceptor in GaN. This work was supported by NSF.

EXPERIENCE IN INCINERATION APPLICABLE TO SUPERFUND SITE REMEDIATION

EPA Science Inventory

This document can be used as a reference tool for hazardous waste site remediation where incineration is used as a treatment alternative. It provides the user with information garnered from the experiences of others who use incineration. The document presents useful lessons in ev...

SITE TECHNOLOGY CAPSULE: NOVOCS EVALUATION AT NAS NORTH ISLAND

EPA Science Inventory

This is a SITE Technology Capsule. The MACTEC, Inc. (MACTEC), NoVOCs(TM) in-well volatile organic compounds (VOC) stripping technology is an in-situ groundwater remediation technology designed for the cleanup of groundwater contaminated with VOCs. The NoVOCs(TM) technology was ev...

Time-Dependent Response Versus Scan Angle for MODIS Reflective Solar Bands

NASA Technical Reports Server (NTRS)

Sun, Junqiang; Xiong, Xiaoxiong; Angal, Amit; Chen, Hongda; Wu, Aisheng; Geng, Xu

2014-01-01

The Moderate Resolution Imaging Spectroradiometer (MODIS) instruments currently operate onboard the National Aeronautics and Space Administration (NASA's) Terra and Aqua spacecraft, launched on December 18, 1999 and May 4, 2002, respectively. MODIS has 36 spectral bands, among which 20 are reflective solar bands (RSBs) covering a spectral range from 0.412 to 2.13 µm. The RSBs are calibrated on orbit using a solar diffuser (SD) and an SD stability monitor and with additional measurements from lunar observations via a space view (SV) port. Selected pseudo-invariant desert sites are also used to track the RSB on-orbit gain change, particularly for short-wavelength bands. MODIS views the Earth surface, SV, and the onboard calibrators using a two-sided scan mirror. The response versus scan angle (RVS) of the scan mirror was characterized prior to launch, and its changes are tracked using observations made at different angles of incidence from onboard SD, lunar, and Earth view (EV) measurements. These observations show that the optical properties of the scan mirror have experienced large wavelength-dependent degradation in both the visible and near infrared spectral regions. Algorithms have been developed to track the on-orbit RVS change using the calibrators and the selected desert sites. These algorithms have been applied to both Terra and Aqua MODIS Level 1B (L1B) to improve the EV data accuracy since L1B Collection 4, refined in Collection 5, and further improved in the latest Collection 6 (C6). In C6, two approaches have been used to derive the time-dependent RVS for MODIS RSB. The first approach relies on data collected from sensor onboard calibrators and mirror side ratios from EV observations. The second approach uses onboard calibrators and EV response trending from selected desert sites. This approach is mainly used for the bands with much larger changes in their time-dependent RVS, such as the Terra MODIS bands 1-4, 8, and 9 and the Aqua MODIS bands 8- and 9. In this paper, the algorithms of these approaches are described, their performance is demonstrated, and their impact on L1B products is discussed. In general, the shorter wavelength bands have experienced a larger on-orbit RVS change, which, in general, are mirror side and detector dependent. The on-orbit RVS change due to the degradation of band 8 can be as large as 35 percent for Terra MODIS and 20 percent for Aqua MODIS. Vital to maintaining the accuracy of the MODIS L1B products is an accurate characterization of the on-orbit RVS change. The derived time-independent RVS, implemented in C6, makes an important improvement to the quality of the MODIS L1B products.

Towards a drift-free multi-level Phase Change Memory

NASA Astrophysics Data System (ADS)

Cinar, Ibrahim; Ozdemir, Servet; Cogulu, Egecan; Gokce, Aisha; Stipe, Barry; Katine, Jordan; Aktas, Gulen; Ozatay, Ozhan

For ultra-high density data storage applications, Phase Change Memory (PCM) is considered a potentially disruptive technology. Yet, the long-term reliability of the logic levels corresponding to the resistance states of a PCM device is an important issue for a stable device operation since the resistance levels drift uncontrollably in time. The underlying mechanism for the resistance drift is considered as the structural relaxation and spontaneous crystallization at elevated temperatures. We fabricated a nanoscale single active layer-phase change memory cell with three resistance levels corresponding to crystalline, amorphous and intermediate states by controlling the current injection site geometry. For the intermediate state and the reset state, the activation energies and the trap distances have been found to be 0.021 eV and 0.235 eV, 1.31 nm and 7.56 nm, respectively. We attribute the ultra-low and weakly temperature dependent drift coefficient of the intermediate state (ν = 0.0016) as opposed to that of the reset state (ν = 0.077) as being due to the dominant contribution of the interfacial defects in electrical transport in the case of the mixed phase. Our results indicate that the engineering of interfacial defects will enable a drift-free multi-level PCM device design.

Electron Thermionic Emission from Graphene and a Thermionic Energy Converter

NASA Astrophysics Data System (ADS)

Liang, Shi-Jun; Ang, L. K.

2015-01-01

In this paper, we propose a model to investigate the electron thermionic emission from single-layer graphene (ignoring the effects of the substrate) and to explore its application as the emitter of a thermionic energy converter (TIC). An analytical formula is derived, which is a function of the temperature, work function, and Fermi energy level. The formula is significantly different from the traditional Richardson-Dushman (RD) law for which it is independent of mass to account for the supply function of the electrons in the graphene behaving like massless fermion quasiparticles. By comparing with a recent experiment [K. Jiang et al., Nano Res. 7, 553 (2014)] measuring electron thermionic emission from suspended single-layer graphene, our model predicts that the intrinsic work function of single-layer graphene is about 4.514 eV with a Fermi energy level of 0.083 eV. For a given work function, a scaling of T3 is predicted, which is different from the traditional RD scaling of T2. If the work function of the graphene is lowered to 2.5-3 eV and the Fermi energy level is increased to 0.8-0.9 eV, it is possible to design a graphene-cathode-based TIC operating at around 900 K or lower, as compared with the metal-based cathode TIC (operating at about 1500 K). With a graphene-based cathode (work function=4.514 eV ) at 900 K and a metallic-based anode (work function=2.5 eV ) like LaB6 at 425 K, the efficiency of our proposed TIC is about 45%.

Medium Duty ARRA Data Reporting and Analysis; NREL (National Renewable Energy Laboratory)

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

Kelly, Kenneth; Duran, Adam; Ragatz, Adam

Medium-duty (MD) electric vehicle (EV) data collection and analysis will help drive design, purchase, and research investments. Over 4 million miles and 160,000 driving days of EV driving data were collected under this project. Publicly available data help drive technology research, development, and deployment. Feeding the vocational database for future analysis will lead to a better understanding of usage and will result in better design optimization and technology implementation. The performance of a vehicle varies with drive cycle and cargo load - MD vehicles are 'multi-functional.' Environment and accessory loads affect vehicle range and in turn add cost by addingmore » battery capacity. MD EV vehicles can function in vocations traditionally serviced by gasoline or diesel vehicles. Facility implications (i.e., demand charges) need to be understood as part of site-based analysis for EV implementation.« less

The trap states in lightly Mg-doped GaN grown by MOVPE on a freestanding GaN substrate

NASA Astrophysics Data System (ADS)

Narita, Tetsuo; Tokuda, Yutaka; Kogiso, Tatsuya; Tomita, Kazuyoshi; Kachi, Tetsu

2018-04-01

We investigated traps in lightly Mg-doped (2 × 1017 cm-3) p-GaN fabricated by metalorganic vapor phase epitaxy (MOVPE) on a freestanding GaN substrate and the subsequent post-growth annealing, using deep level transient spectroscopy. We identified four hole traps with energy levels of EV + 0.46, 0.88, 1.0, and 1.3 eV and one electron trap at EC - 0.57 eV in a p-type GaN layer uniformly doped with magnesium (Mg). The Arrhenius plot of hole traps with the highest concentration (˜3 × 1016 cm-3) located at EV + 0.88 eV corresponded to those of hole traps ascribed to carbon on nitrogen sites in n-type GaN samples grown by MOVPE. In fact, the range of the hole trap concentrations at EV + 0.88 eV was close to the carbon concentration detected by secondary ion mass spectroscopy. Moreover, the electron trap at EC - 0.57 eV was also identical to the dominant electron traps commonly observed in n-type GaN. Together, these results suggest that the trap states in the lightly Mg-doped GaN grown by MOVPE show a strong similarity to those in n-type GaN, which can be explained by the Fermi level close to the conduction band minimum in pristine MOVPE grown samples due to existing residual donors and Mg-hydrogen complexes.

Initial results from the NASA Lewis Bumpy Torus experiment. [of steady-state ion heating method based on modified Penning discharge

NASA Technical Reports Server (NTRS)

Roth, J. R.; Richardson, R. W.; Gerdin, G. A.

1973-01-01

Initial results were obtained from low power operation of the NASA Lewis Bumpy Torus experiment, in which a steady-state ion heating method based on the modified Penning discharge is applied in a bumpy torus confinement geometry. The magnet facility consists of 12 superconducting coils, each 19 cm i.d. and capable of 3.0 T, equally spaced in a toroidal array 1.52 m in major diameter. A 18 cm i.d. anode ring is located at each of the 12 midplanes and is maintained at high positive potentials by a dc power supply. Initial observations indicate electron temperatures from 10 to 150 eV, and ion kinetic temperatures from 200 eV to 1200 eV. Two modes of operation were observed, which depend on background pressure, and have different radial density profiles. Steady state neutron production was observed. The ion heating process in the bumpy torus appears to parallel closely the mechanism observed when the modified Penning discharge was operated in a simple magnetic mirror field.

Solar-Assisted Electric Vehicle Charging Station Interim Report

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

Lapsa, Melissa Voss; Durfee, Norman; Maxey, L Curt

2011-09-01

Oak Ridge National Laboratory (ORNL) has been awarded $6.8 million in the Department of Energy (DOE) American Recovery and Reinvestment Act (ARRA) funds as part of an overall $114.8 million ECOtality grant with matching funds from regional partners to install 125 solar-assisted Electric Vehicle (EV) charging stations across Knoxville, Nashville, Chattanooga, and Memphis. Significant progress has been made toward completing the scope with the installation of 25 solar-assisted charging stations at ORNL; six stations at Electric Power Research Institute (EPRI); and 27 stations at Nissan's Smyrna and Franklin sites, with three more stations under construction at Nissan's new lithium-ion batterymore » plant. Additionally, the procurement process for contracting the installation of 34 stations at Knoxville, the University of Tennessee Knoxville (UTK), and Nashville sites is underway with completion of installation scheduled for early 2012. Progress is also being made on finalizing sites and beginning installations of 30 stations in Nashville, Chattanooga, and Memphis by EPRI and Tennessee Valley Authority (TVA). The solar-assisted EV charging station project has made great strides in fiscal year 2011. A total of 58 solar-assisted EV parking spaces have been commissioned in East and Middle Tennessee, and progress on installing the remaining 67 spaces is well underway. The contract for the 34 stations planned for Knoxville, UTK, and Nashville should be underway in October with completion scheduled for the end of March 2012; the remaining three Nissan stations are under construction and scheduled to be complete in November; and the EPRI/TVA stations for Chattanooga, Vanderbilt, and Memphis are underway and should be complete by the end of March 2012. As additional Nissan LEAFs are being delivered, usage of the charging stations has increased substantially. The project is on course to complete all 125 solar-assisted EV charging stations in time to collect meaningful data by the end of government fiscal year 2012. Lessons learned from the sites completed thus far are being incorporated and are proving to be invaluable in completion of the remaining sites.« less

Spectral engineering of LaF3:Ce3+ nanoparticles: The role of Ce3+ in surface sites

NASA Astrophysics Data System (ADS)

Jacobsohn, L. G.; Toncelli, A.; Sprinkle, K. B.; Kucera, C. J.; Ballato, J.

2012-04-01

Due to the high surface-to-volume ratio, luminescence centers on the surface have relative dominance in the overall spectral response of nanoparticles. The luminescence of LaF3:Ce3+ nanoparticles was investigated in the spectral and temporal domains with a particular focus on the role of Ce3+ on the surface. These nanoparticles present two luminescence bands at 4.10 eV and 4.37 eV attributed to Ce3+ transitions from the 5d level to the spin-orbit split 4f ground levels 2F5/2 and 2F7/2, in addition to a low-energy band at 3.62 eV that has been attributed to Ce3+ ions residing in perturbed sites. The growth of up to three undoped shells, ca. 0.9 nm thick each, around the core promoted a progressive enhancement of luminescence output, concomitant with an increase in the fluorescence lifetime due to the weakening of energy transfer through multipolar interaction between Ce3+ in the core and quenching defects on the surface. Also, the growth of the first shell led to a decrease in the relative intensity of the low-energy band and a 0.23 eV shift to higher energies. These results were interpreted as being due to the existence of two types of perturbed sites, one on the surface that is eliminated by the growth of the first shell, and another within the volume of the nanoparticle, similar to observations in bulk single crystals. This work demonstrates how surface engineering can affect and control the luminescence behavior of this nanomaterial.

Development of GaN/AIN Self Assembled Quantum Dots for Room Temperature Operation of Quantum Dot Devices

DTIC Science & Technology

2003-01-01

Kramer Fabrication of hcp-Co nanocrystals via rapid pyrolysis in inverse PS - b - P2VP micelles and thermal annealing Nano Letters In Press ...the figure) and different pump photon energies. a) hν=1.684eV, b ) hν= 1.536eV and c) hν= 1.433eV. All spectra are normalized to the maximum value of...correlation functions of two consecutively emitted photons from a single excited semiconductor quantum dot. We have shown that a 6 a) b ) 0.10 [ML/s] 250 nm 3.0

Observation of the ankle and evidence for a high-energy break in the cosmic ray spectrum

NASA Astrophysics Data System (ADS)

Abbasi, R.; Abuzayyad, T.; Amman, J.; Archbold, G.; Atkins, R.; Bellido, J.; Belov, K.; Belz, J.; Benzvi, S.; Bergman, D.

2005-07-01

We have measured the cosmic ray spectrum at energies above $10^{17}$ eV using the two air fluorescence detectors of the High Resolution Fly's Eye experiment operating in monocular mode. We describe the detector, PMT and atmospheric calibrations, and the analysis techniques for the two detectors. We fit the spectrum to models describing galactic and extragalactic sources. Our measured spectrum gives an observation of a feature known as the ``ankle'' near $3\\times 10^{18}$ eV, and strong evidence for a suppression near $6\\times 10^{19}$ eV.

Probing carbon impurities in hexagonal boron nitride epilayers

NASA Astrophysics Data System (ADS)

Uddin, M. R.; Li, J.; Lin, J. Y.; Jiang, H. X.

2017-05-01

Carbon doped hexagonal boron nitride epilayers have been grown by metal organic chemical vapor deposition. Photocurrent excitation spectroscopy has been utilized to probe the energy levels associated with carbon impurities in hexagonal boron nitride (h-BN). The observed transition peaks in photocurrent excitation spectra correspond well to the energy positions of the bandgap, substitutional donors (CB, carbon impurities occupying boron sites), and substitutional acceptors (CN, carbon impurities occupying nitrogen sites). From the observed transition peak positions, the derived energy level of CB donors in h-BN is ED ˜ 0.45 eV, which agrees well with the value deduced from the temperature dependent electrical resistivity. The present study further confirms that the room temperature bandgap of h-BN is about 6.42-6.45 eV, and the CN deep acceptors have an energy level of about 2.2-2.3 eV. The results also infer that carbon doping introduces both shallow donors (CB) and deep acceptors (CN) via self-compensation, and the energy level of carbon donors appears to be too deep to enable carbon as a viable candidate as an n-type dopant in h-BN epilayers.

Building a QC Database of Meteorological Data From NASA KSC and the United States Air Force's Eastern Range

NASA Technical Reports Server (NTRS)

Brenton, James C.; Barbre, Robert E.; Orcutt, John M.; Decker, Ryan K.

2018-01-01

The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) Natural Environments Branch (EV44) has provided atmospheric databases and analysis in support of space vehicle design and day-of-launch operations for NASA and commercial launch vehicle programs launching from the NASA Kennedy Space Center (KSC), co-located on the United States Air Force's Eastern Range (ER) at the Cape Canaveral Air Force Station. The ER is one of the most heavily instrumented sites in the United States measuring various atmospheric parameters on a continuous basis. An inherent challenge with the large databases that EV44 receives from the ER consists of ensuring erroneous data are removed from the databases, and thus excluded from launch vehicle design analyses. EV44 has put forth great effort in developing quality control (QC) procedures for individual meteorological instruments; however, no standard QC procedures for all databases currently exist resulting in QC databases that have inconsistencies in variables, methodologies, and periods of record. The goal of this activity is to use the previous efforts by EV44 to develop a standardized set of QC procedures from which to build flags within the meteorological databases from KSC and the ER, while maintaining open communication with end users from the launch community to develop ways to improve, adapt and grow the QC database. Details of the QC checks are described. The flagged data points will be plotted in a graphical user interface (GUI) as part of a manual confirmation that the flagged data do indeed need to be removed from the archive. As the rate of launches increases with additional launch vehicle programs, more emphasis is being placed to continually update and check weather databases for data quality before use in launch vehicle design and certification analyses.

Low Work Function 2.81 eV Rb2CO3-Doped Polyethylenimine Ethoxylated for Inverted Organic Light-Emitting Diodes.

PubMed

Kim, Jeonggi; Kim, Hyo-Min; Jang, Jin

2018-06-06

We report a low work function (2.81 eV), Rb 2 CO 3 -doped polyethyleneimine ethoxylated (PEIE) which is used for highly efficient and long-lifetime, inverted organic light-emitting diodes (OLEDs). Doping Rb 2 CO 3 into PEIE decreases the work function of Li-doped ZnO (LZO) by 1.0 eV and thus significantly improves electron injection ability into the emission layer (EML). The inverted OLED with PEIE:Rb 2 CO 3 interfacial layer (IL) exhibits higher efficiency and longer operation lifetime than those of the device with a PEIE IL. It is found also that Mg-doped ZnO (MZO) can be used instead of LZO as electron transporting layer. Rb 2 CO 3 shows a low work function of 2.81 eV. The OLED with MZO/PEIE:Rb 2 CO 3 exhibits low operating voltage of 5.0 V at 1000 cd m -2 and low efficiency roll-off of 11.8% at high luminance of 10 000 cd m -2 . The results are due to the suppressed exciton quenching at the MZO/organic EML interface.

D autoionization states of He and ionic H

NASA Technical Reports Server (NTRS)

Bhatia, A. K.

1972-01-01

Positions of the lowest 1,3De autoionization states of He and H(-) below the n = 2 level of the He(+) and H were calculated variationally, using Feshbach's Q-operator formalism. The trial wave function is of the Hylleraas-type with appropriate angular momentum factors. The widths and the shifts of the states have also been calculated. The shifts are found to be positive for all the states calculated here. The results with 112 terms for most states are lower than any previously calculated. The calculated lowest autoionization states of the He and H(-) (relative to the ground states of He and H respectively) are 59.902 eV and 10.1185 eV, in good agreement with the observed values of 59.9 eV and 10.13 + or 0.015 eV.

Proton and hydrogen transport through two-dimensional monolayers

NASA Astrophysics Data System (ADS)

Seel, Max; Pandey, Ravindra

2016-06-01

Diffusion of protons and hydrogen atoms in representative two-dimensional materials is investigated. Specifically, density functional calculations were performed on graphene, hexagonal boron nitride (h-BN), phosphorene, silicene, and molybdenum disulfide (MoS2) monolayers to study the surface interaction and penetration barriers for protons and hydrogen atoms employing finite cluster models. The calculated barrier heights correlate approximately with the size of the opening formed by the three-fold open sites in the monolayers considered. They range from 1.56 eV (proton) and 4.61 eV (H) for graphene to 0.12 eV (proton) and 0.20 eV (H) for silicene. The results indicate that only graphene and h-BN monolayers have the potential for membranes with high selective permeability. The MoS2 monolayer behaves differently: protons and H atoms become trapped between the outer S layers in the Mo plane in a well with a depth of 1.56 eV (proton) and 1.5 eV (H atom), possibly explaining why no proton transport was detected, suggesting MoS2 as a hydrogen storage material instead. For graphene and h-BN, off-center proton penetration reduces the barrier to 1.38 eV for graphene and 0.11 eV for h-BN. Furthermore, Pt acting as a substrate was found to have a negligible effect on the barrier height. In defective graphene, the smallest barrier for proton diffusion (1.05 eV) is found for an oxygen-terminated defect. Therefore, it seems more likely that thermal protons can penetrate a monolayer of h-BN but not graphene and defects are necessary to facilitate the proton transport in graphene.

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

Desjardins, G.C.; Beaudet, A.; Brawer, J.R.

The distribution and density of selectively labeled mu-, delta-, and kappa-opioid binding sites were examined by in vitro radioautography in the hypothalamus of normal, estradiol valerate (EV)-injected, and estradiol (E2)-implanted female rats. Hypothalamic beta-endorphin concentration was also examined by RIA in these three groups of animals. Quantitative analysis of film radioautographs demonstrated a selective increase in mu-opioid binding in the medial preoptic area of EV-treated, but not of E2-implanted rats. However, both these estrogenized groups exhibited a reduction in the density of delta-opioid binding in the suprachiasmatic nucleus. Statistically significant changes between either estrogenized groups were not observed for kappa-opioidmore » binding. Results on the hypothalamic concentration of beta-endorphin indicated a marked reduction in EV-injected animals with respect to controls. In contrast, the E2-implanted animals exhibited beta-endorphin concentrations similar to controls. The present results confirm the increase in opioid receptor binding previously reported in the hypothalamus of EV-treated rats and further demonstrate that this increase is confined to the medial preoptic area and exclusively concerns mu-opioid receptors. The concomitant reduction in beta-endorphin levels observed in the same group of animals suggests that the observed increase in mu-opioid binding could reflect a chronic up-regulation of the receptor in response to compromised beta-endorphin input. Given the restriction of this effect to the site of origin of LHRH neurons and the demonstrated inhibitory role of opioids on LHRH release, it is tempting to postulate that such up-regulation could lead to the suppression of the plasma LH pattern that characterizes polycystic ovarian disease in the EV-treated rat.« less

Biochemical characterization of recombinant Enterovirus 71 3C protease with fluorogenic model peptide substrates and development of a biochemical assay.

PubMed

Shang, Luqing; Zhang, Shumei; Yang, Xi; Sun, Jixue; Li, Linfeng; Cui, Zhengjie; He, Qiuhong; Guo, Yu; Sun, Yuna; Yin, Zheng

2015-04-01

Enterovirus 71 (EV71), a primary pathogen of hand, foot, and mouth disease (HFMD), affects primarily infants and children. Currently, there are no effective drugs against HFMD. EV71 3C protease performs multiple tasks in the viral replication, which makes it an ideal antiviral target. We synthesized a small set of fluorogenic model peptides derived from cleavage sites of EV71 polyprotein and examined their efficiencies of cleavage by EV71 3C protease. The novel peptide P08 [(2-(N-methylamino)benzoyl) (NMA)-IEALFQGPPK(DNP)FR] was determined to be the most efficiently cleaved by EV71 3C protease, with a kinetic constant kcat/Km of 11.8 ± 0.82 mM(-1) min(-1). Compared with literature reports, P08 gave significant improvement in the signal/background ratio, which makes it an attractive substrate for assay development. A Molecular dynamics simulation study elaborated the interactions between substrate P08 and EV71 3C protease. Arg39, which is located at the bottom of the S2 pocket of EV71 3C protease, may participate in the proteolysis process of substrates. With an aim to evaluate EV71 3C protease inhibitors, a reliable and robust biochemical assay with a Z' factor of 0.87 ± 0.05 was developed. A novel compound (compound 3) (50% inhibitory concentration [IC50] = 1.89 ± 0.25 μM) was discovered using this assay, which effectively suppressed the proliferation of EV 71 (strain Fuyang) in rhabdomyosarcoma (RD) cells with a highly selective index (50% effective concentration [EC50] = 4.54 ± 0.51 μM; 50% cytotoxic concentration [CC50] > 100 μM). This fast and efficient assay for lead discovery and optimization provides an ideal platform for anti-EV71 drug development targeting 3C protease. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Virtually pure near-infrared electroluminescence from exciplexes at polyfluorene/hexaazatrinaphthylene interfaces

NASA Astrophysics Data System (ADS)

Tregnago, G.; Fléchon, C.; Choudhary, S.; Gozalvez, C.; Mateo-Alonso, A.; Cacialli, F.

2014-10-01

Electronic processes at the heterojunction between chemically different organic semiconductors are of special significance for devices such as light-emitting diodes (LEDs) and photovoltaic diodes. Here, we report the formation of an exciplex state at the heterojunction of an electron-transporting material, a functionalized hexaazatrinaphthylene, and a hole-transporting material, poly(9,9-dioctylfluorene-alt-N-(4-butylphenyl)diphenylamine) (TFB). The energetics of the exciplex state leads to a spectral shift of ˜1 eV between the exciton and the exciplex peak energies (at 2.58 eV and 1.58 eV, respectively). LEDs incorporating such bulk heterojunctions display complete quenching of the exciton luminescence, and a nearly pure near-infrared electroluminescence arising from the exciplex (at ˜1.52 eV) with >98% of the emission at wavelengths above 700 nm at any operational voltage.

Systematic Methodological Evaluation of a Multiplex Bead-Based Flow Cytometry Assay for Detection of Extracellular Vesicle Surface Signatures

PubMed Central

Wiklander, Oscar P. B.; Bostancioglu, R. Beklem; Welsh, Joshua A.; Zickler, Antje M.; Murke, Florian; Corso, Giulia; Felldin, Ulrika; Hagey, Daniel W.; Evertsson, Björn; Liang, Xiu-Ming; Gustafsson, Manuela O.; Mohammad, Dara K.; Wiek, Constanze; Hanenberg, Helmut; Bremer, Michel; Gupta, Dhanu; Björnstedt, Mikael; Giebel, Bernd; Nordin, Joel Z.; Jones, Jennifer C.; EL Andaloussi, Samir; Görgens, André

2018-01-01

Extracellular vesicles (EVs) can be harvested from cell culture supernatants and from all body fluids. EVs can be conceptually classified based on their size and biogenesis as exosomes and microvesicles. Nowadays, it is however commonly accepted in the field that there is a much higher degree of heterogeneity within these two subgroups than previously thought. For instance, the surface marker profile of EVs is likely dependent on the cell source, the cell’s activation status, and multiple other parameters. Within recent years, several new methods and assays to study EV heterogeneity in terms of surface markers have been described; most of them are being based on flow cytometry. Unfortunately, such methods generally require dedicated instrumentation, are time-consuming and demand extensive operator expertise for sample preparation, acquisition, and data analysis. In this study, we have systematically evaluated and explored the use of a multiplex bead-based flow cytometric assay which is compatible with most standard flow cytometers and facilitates a robust semi-quantitative detection of 37 different potential EV surface markers in one sample simultaneously. First, assay variability, sample stability over time, and dynamic range were assessed together with the limitations of this assay in terms of EV input quantity required for detection of differently abundant surface markers. Next, the potential effects of EV origin, sample preparation, and quality of the EV sample on the assay were evaluated. The findings indicate that this multiplex bead-based assay is generally suitable to detect, quantify, and compare EV surface signatures in various sample types, including unprocessed cell culture supernatants, cell culture-derived EVs isolated by different methods, and biological fluids. Furthermore, the use and limitations of this assay to assess heterogeneities in EV surface signatures was explored by combining different sets of detection antibodies in EV samples derived from different cell lines and subsets of rare cells. Taken together, this validated multiplex bead-based flow cytometric assay allows robust, sensitive, and reproducible detection of EV surface marker expression in various sample types in a semi-quantitative way and will be highly valuable for many researchers in the EV field in different experimental contexts.

Systematic Methodological Evaluation of a Multiplex Bead-Based Flow Cytometry Assay for Detection of Extracellular Vesicle Surface Signatures.

PubMed

Wiklander, Oscar P B; Bostancioglu, R Beklem; Welsh, Joshua A; Zickler, Antje M; Murke, Florian; Corso, Giulia; Felldin, Ulrika; Hagey, Daniel W; Evertsson, Björn; Liang, Xiu-Ming; Gustafsson, Manuela O; Mohammad, Dara K; Wiek, Constanze; Hanenberg, Helmut; Bremer, Michel; Gupta, Dhanu; Björnstedt, Mikael; Giebel, Bernd; Nordin, Joel Z; Jones, Jennifer C; El Andaloussi, Samir; Görgens, André

2018-01-01

Extracellular vesicles (EVs) can be harvested from cell culture supernatants and from all body fluids. EVs can be conceptually classified based on their size and biogenesis as exosomes and microvesicles. Nowadays, it is however commonly accepted in the field that there is a much higher degree of heterogeneity within these two subgroups than previously thought. For instance, the surface marker profile of EVs is likely dependent on the cell source, the cell's activation status, and multiple other parameters. Within recent years, several new methods and assays to study EV heterogeneity in terms of surface markers have been described; most of them are being based on flow cytometry. Unfortunately, such methods generally require dedicated instrumentation, are time-consuming and demand extensive operator expertise for sample preparation, acquisition, and data analysis. In this study, we have systematically evaluated and explored the use of a multiplex bead-based flow cytometric assay which is compatible with most standard flow cytometers and facilitates a robust semi-quantitative detection of 37 different potential EV surface markers in one sample simultaneously. First, assay variability, sample stability over time, and dynamic range were assessed together with the limitations of this assay in terms of EV input quantity required for detection of differently abundant surface markers. Next, the potential effects of EV origin, sample preparation, and quality of the EV sample on the assay were evaluated. The findings indicate that this multiplex bead-based assay is generally suitable to detect, quantify, and compare EV surface signatures in various sample types, including unprocessed cell culture supernatants, cell culture-derived EVs isolated by different methods, and biological fluids. Furthermore, the use and limitations of this assay to assess heterogeneities in EV surface signatures was explored by combining different sets of detection antibodies in EV samples derived from different cell lines and subsets of rare cells. Taken together, this validated multiplex bead-based flow cytometric assay allows robust, sensitive, and reproducible detection of EV surface marker expression in various sample types in a semi-quantitative way and will be highly valuable for many researchers in the EV field in different experimental contexts.

Application of SOFC for electric vehicle

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

Yamada, K.; Mizusaki, J.; Sasaki, H.

1995-12-31

Changing from gasoline powered vehicles to electric vehicles (EVs) will provide positive environmental effects. A present disadvantage of EVs with secondary battery systems is a short driving range. This can be improved by the application of a hybrid system of SOFCs and batteries. For that system, both tubular and planer types of SOFCs having 10kW power are designed which can be used for passenger cars with naphtha as fuel operated at 880--850 C . The tubular type has 106 liters in volume and 100kg in weight, and were smaller and lighter than the planer type. Subjects to be investigated onmore » SOFCs for EVs are described.« less

Adsorbing H₂S onto a single graphene sheet: A possible gas sensor

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

Reshak, A. H., E-mail: maalidph@yahoo.co.uk; Center of Excellence Geopolymer and Green Technology, School of Material Engineering, University Malaysia Perlis, 01007 Kangar, Perlis; Auluck, S.

2014-09-14

The electronic structure of pristine graphene sheet and the resulting structure of adsorbing a single molecule of H₂S on pristine graphene in three different sites (bridge, top, and hollow) are studied using the full potential linearized augmented plane wave method. Our calculations show that the adsorption of H₂S molecule on the bridge site opens up a small direct energy gap of about 0.1 eV at symmetry point M, while adsorption of H₂S on top site opens a gap of 0.3 eV around the symmetry point K. We find that adsorbed H₂S onto the hollow site of pristine graphene sheet causesmore » to push the conduction band minimum and the valence band maximum towards Fermi level resulting in a metallic behavior. Comparing the angular momentum decomposition of the atoms projected electronic density of states of pristine graphene sheet with that of H₂S–graphene for three different cases, we find a significant influence of the location of the H₂S molecule on the electronic properties especially the strong hybridization between H₂S molecule and graphene sheet.« less

Probing optical band gaps at the nanoscale in NiFe₂O₄ and CoFe₂O₄ epitaxial films by high resolution electron energy loss spectroscopy

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

Dileep, K.; Loukya, B.; Datta, R., E-mail: ranjan@jncasr.ac.in

2014-09-14

Nanoscale optical band gap variations in epitaxial thin films of two different spinel ferrites, i.e., NiFe₂O₄ (NFO) and CoFe₂O₄ (CFO), have been investigated by spatially resolved high resolution electron energy loss spectroscopy. Experimentally, both NFO and CFO show indirect/direct band gaps around 1.52 eV/2.74 and 2.3 eV, and 1.3 eV/2.31 eV, respectively, for the ideal inverse spinel configuration with considerable standard deviation in the band gap values for CFO due to various levels of deviation from the ideal inverse spinel structure. Direct probing of the regions in both the systems with tetrahedral A site cation vacancy, which is distinct frommore » the ideal inverse spinel configuration, shows significantly smaller band gap values. The experimental results are supported by the density functional theory based modified Becke-Johnson exchange correlation potential calculated band gap values for the different cation configurations.« less

EVpedia: a community web portal for extracellular vesicles research.

PubMed

Kim, Dae-Kyum; Lee, Jaewook; Kim, Sae Rom; Choi, Dong-Sic; Yoon, Yae Jin; Kim, Ji Hyun; Go, Gyeongyun; Nhung, Dinh; Hong, Kahye; Jang, Su Chul; Kim, Si-Hyun; Park, Kyong-Su; Kim, Oh Youn; Park, Hyun Taek; Seo, Ji Hye; Aikawa, Elena; Baj-Krzyworzeka, Monika; van Balkom, Bas W M; Belting, Mattias; Blanc, Lionel; Bond, Vincent; Bongiovanni, Antonella; Borràs, Francesc E; Buée, Luc; Buzás, Edit I; Cheng, Lesley; Clayton, Aled; Cocucci, Emanuele; Dela Cruz, Charles S; Desiderio, Dominic M; Di Vizio, Dolores; Ekström, Karin; Falcon-Perez, Juan M; Gardiner, Chris; Giebel, Bernd; Greening, David W; Gross, Julia Christina; Gupta, Dwijendra; Hendrix, An; Hill, Andrew F; Hill, Michelle M; Nolte-'t Hoen, Esther; Hwang, Do Won; Inal, Jameel; Jagannadham, Medicharla V; Jayachandran, Muthuvel; Jee, Young-Koo; Jørgensen, Malene; Kim, Kwang Pyo; Kim, Yoon-Keun; Kislinger, Thomas; Lässer, Cecilia; Lee, Dong Soo; Lee, Hakmo; van Leeuwen, Johannes; Lener, Thomas; Liu, Ming-Lin; Lötvall, Jan; Marcilla, Antonio; Mathivanan, Suresh; Möller, Andreas; Morhayim, Jess; Mullier, François; Nazarenko, Irina; Nieuwland, Rienk; Nunes, Diana N; Pang, Ken; Park, Jaesung; Patel, Tushar; Pocsfalvi, Gabriella; Del Portillo, Hernando; Putz, Ulrich; Ramirez, Marcel I; Rodrigues, Marcio L; Roh, Tae-Young; Royo, Felix; Sahoo, Susmita; Schiffelers, Raymond; Sharma, Shivani; Siljander, Pia; Simpson, Richard J; Soekmadji, Carolina; Stahl, Philip; Stensballe, Allan; Stępień, Ewa; Tahara, Hidetoshi; Trummer, Arne; Valadi, Hadi; Vella, Laura J; Wai, Sun Nyunt; Witwer, Kenneth; Yáñez-Mó, María; Youn, Hyewon; Zeidler, Reinhard; Gho, Yong Song

2015-03-15

Extracellular vesicles (EVs) are spherical bilayered proteolipids, harboring various bioactive molecules. Due to the complexity of the vesicular nomenclatures and components, online searches for EV-related publications and vesicular components are currently challenging. We present an improved version of EVpedia, a public database for EVs research. This community web portal contains a database of publications and vesicular components, identification of orthologous vesicular components, bioinformatic tools and a personalized function. EVpedia includes 6879 publications, 172 080 vesicular components from 263 high-throughput datasets, and has been accessed more than 65 000 times from more than 750 cities. In addition, about 350 members from 73 international research groups have participated in developing EVpedia. This free web-based database might serve as a useful resource to stimulate the emerging field of EV research. The web site was implemented in PHP, Java, MySQL and Apache, and is freely available at http://evpedia.info. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Changes in the EV-A71 Genome through Recombination and Spontaneous Mutations: Impact on Virulence.

PubMed

Mandary, Madiiha Bibi; Poh, Chit Laa

2018-06-12

Enterovirus 71 (EV-A71) is a major etiological agent of hand, foot and mouth disease (HFMD) that mainly affects young children less than five years old. The onset of severe HFMD is due to neurological complications bringing about acute flaccid paralysis and pulmonary oedema. In this review, we address how genetic events such as recombination and spontaneous mutations could change the genomic organization of EV-A71, leading to an impact on viral virulence. An understanding of the recombination mechanism of the poliovirus and non-polio enteroviruses will provide further evidence of the emergence of novel strains responsible for fatal HFMD outbreaks. We aim to see if the virulence of EV-A71 is contributed solely by the presence of fatal strains or is due to the co-operation of quasispecies within a viral population. The phenomenon of quasispecies within the poliovirus is discussed to reflect viral fitness, virulence and its implications for EV-A71. Ultimately, this review gives an insight into the evolution patterns of EV-A71 by looking into its recombination history and how spontaneous mutations would affect its virulence.

An integrated double-filtration microfluidic device for isolation, enrichment and quantification of urinary extracellular vesicles for detection of bladder cancer

PubMed Central

Liang, Li-Guo; Kong, Meng-Qi; Zhou, Sherry; Sheng, Ye-Feng; Wang, Ping; Yu, Tao; Inci, Fatih; Kuo, Winston Patrick; Li, Lan-Juan; Demirci, Utkan; Wang, ShuQi

2017-01-01

Extracellular vesicles (EVs), including exosomes and microvesicles, are present in a variety of bodily fluids, and the concentration of these sub-cellular vesicles and their associated biomarkers (proteins, nucleic acids, and lipids) can be used to aid clinical diagnosis. Although ultracentrifugation is commonly used for isolation of EVs, it is highly time-consuming, labor-intensive and instrument-dependent for both research laboratories and clinical settings. Here, we developed an integrated double-filtration microfluidic device that isolated and enriched EVs with a size range of 30–200 nm from urine, and subsequently quantified the EVs via a microchip ELISA. Our results showed that the concentration of urinary EVs was significantly elevated in bladder cancer patients (n = 16) compared to healthy controls (n = 8). Receiver operating characteristic (ROC) analysis demonstrated that this integrated EV double-filtration device had a sensitivity of 81.3% at a specificity of 90% (16 bladder cancer patients and 8 healthy controls). Thus, this integrated device has great potential to be used in conjunction with urine cytology and cystoscopy to improve clinical diagnosis of bladder cancer in clinics and at point-of-care (POC) settings. PMID:28436447

Tough Choices.

ERIC Educational Resources Information Center

Kennedy, Mike

2002-01-01

Explores the decision by colleges and universities to outsource or self-operate school services such as food, bookstores, and maintenance. Discusses factors influencing the decision, the pros and cons of outsourcing, and the importance of maintaining the goal of improving operations. (EV)

Advanced integrated enhanced vision systems

NASA Astrophysics Data System (ADS)

Kerr, J. R.; Luk, Chiu H.; Hammerstrom, Dan; Pavel, Misha

2003-09-01

In anticipation of its ultimate role in transport, business and rotary wing aircraft, we clarify the role of Enhanced Vision Systems (EVS): how the output data will be utilized, appropriate architecture for total avionics integration, pilot and control interfaces, and operational utilization. Ground-map (database) correlation is critical, and we suggest that "synthetic vision" is simply a subset of the monitor/guidance interface issue. The core of integrated EVS is its sensor processor. In order to approximate optimal, Bayesian multi-sensor fusion and ground correlation functionality in real time, we are developing a neural net approach utilizing human visual pathway and self-organizing, associative-engine processing. In addition to EVS/SVS imagery, outputs will include sensor-based navigation and attitude signals as well as hazard detection. A system architecture is described, encompassing an all-weather sensor suite; advanced processing technology; intertial, GPS and other avionics inputs; and pilot and machine interfaces. Issues of total-system accuracy and integrity are addressed, as well as flight operational aspects relating to both civil certification and military applications in IMC.

Solar Wind Implantation into Lunar Regolith: Hydrogen Retention in a Surface with Defects

NASA Technical Reports Server (NTRS)

Farrell, W. M.; Hurley, D. M.; Zimmerman, M. I.

2014-01-01

Solar wind protons are implanted directly into the top 100 nm of the lunar near-surface region, but can either quickly diffuse out of the surface or be retained, depending upon surface temperature and the activation energy, U, associated with the implantation site. In this work, we explore the distribution of activation energies upon implantation and the associated hydrogen-retention times; this for comparison with recent observation of OH on the lunar surface. We apply a Monte Carlo approach: for simulated solar wind protons at a given local time, we assume a distribution of U values with a central peak, U(sub c) and width, U(sub w), and derive the fraction retained for long periods in the near-surface. We find that surfaces characterized by a distribution with predominantly large values of U (greater than 1 eV) like that expected at defect sites will retain implanted H (to likely form OH). Surfaces with the distribution predominantly at small values of U (less than 0.2 eV) will quickly diffuse away implanted H. However, surfaces with a large portion of activation energies between 0.3 eV less than U less than 0.9 eV will tend to be H-retentive in cool conditions but transform into H-emissive surfaces when warmed (as when the surface rotates into local noon). These mid-range activation energies give rise to a diurnal effect with diffusive loss of H at noontime.

Tolerability and immunogenicity of an inactivated enterovirus 71 vaccine in Chinese healthy adults and children: an open label, phase 1 clinical trial.

PubMed

Meng, Fan-Yue; Li, Jing-Xin; Li, Xiu-Ling; Chu, Kai; Zhang, Yun-Tao; Ji, Hong; Li, Liang; Liang, Zheng-Lun; Zhu, Feng-Cai

2012-05-01

In this open labeled phase 1 clinical trial with enterovirus 71 (EV71) vaccine (ClinicalTrials.gov number: NCT01267903) performed in Donghai County, Jiangsu Province, China, in January 2011. A total of 100 healthy participants, stratified by age (40 adults aged 16-22 y and 60 children aged 6-15 y), were enrolled from volunteers and sequentially received EV71 vaccines of 160U (only for children), 320U, or 640U on day 0 and 28, in a manner of dose escalation. All the participants were followed for 28 d after each shot. During the study period, 37 participants reported at least one injection-site or systemic adverse reaction. No case of grade 3 adverse reaction or serious adverse event (SAE) was observed. Also no dose-related increase in reaction rate was noticed. Pain at injection-site and fever were the most frequently reported local and systematic reaction, respectively. The studied EV71 vaccines demonstrated acceptable tolerability and no anti-nuclear antibody (ANA) seropositive was detected pre or post vaccinations in participants. Also, no clinically significant abnormal change for the liver or kidney function indexes was found. In the according-to-protocol cohort for immunogenicity, it was observed one dose of EV71 vaccine elicited good immune response in the participants, especially for the ones with sero-positive baseline. No obvious dose-response relationship for immunogenicity was found.

Adsorption and diffusion of lithium in a graphene/blue-phosphorus heterostructure and the effect of an external electric field.

PubMed

Fan, Kaimin; Tang, Jing; Wu, Shiyun; Yang, Chengfu; Hao, Jiabo

2016-12-21

The adsorption and diffusion behaviors of lithium (Li) in a graphene/blue-phosphorus (G/BP) heterostructure have been investigated using a first principles method based on density functional theory (DFT). The effect of an external electric field on the adsorption and diffusion behaviors has also been investigated. The results show that the adsorption energy of Li on the graphene side of the G/BP heterostructure is higher than that on monolayer graphene, and Li adsorption on the BP side of the G/BP/Li system is slightly stronger than that on monolayer BP (BP/Li). The adsorption energy of Li reaches 2.47 eV, however, the energy barriers of Li diffusion decrease in the interlayer of the G/BP heterostructure. The results mentioned above suggest that the rate performance of the G/BP heterostructure is better than that of monolayer graphene. Furthermore, the adsorption energies of Li atoms in the three different most stable sites, i.e., H G , T P and H 1 sites, increase by about 0.49 eV, 0.26 eV, and 0.13 eV, respectively, as the electric field intensity reaches 0.6 V Å -1 . The diffusion energy barrier is significantly decreased by an external electric field. It is demonstrated that the external electric field can not only enhance the adsorption but can also modulate the diffusion barriers of Li atoms in the G/BP heterostructure.

Energy Storage Applications in Power Systems with Renewable Energy Generation

NASA Astrophysics Data System (ADS)

Ghofrani, Mahmoud

In this dissertation, we propose new operational and planning methodologies for power systems with renewable energy sources. A probabilistic optimal power flow (POPF) is developed to model wind power variations and evaluate the power system operation with intermittent renewable energy generation. The methodology is used to calculate the operating and ramping reserves that are required to compensate for power system uncertainties. Distributed wind generation is introduced as an operational scheme to take advantage of the spatial diversity of renewable energy resources and reduce wind power fluctuations using low or uncorrelated wind farms. The POPF is demonstrated using the IEEE 24-bus system where the proposed operational scheme reduces the operating and ramping reserve requirements and operation and congestion cost of the system as compared to operational practices available in the literature. A stochastic operational-planning framework is also proposed to adequately size, optimally place and schedule storage units within power systems with high wind penetrations. The method is used for different applications of energy storage systems for renewable energy integration. These applications include market-based opportunities such as renewable energy time-shift, renewable capacity firming, and transmission and distribution upgrade deferral in the form of revenue or reduced cost and storage-related societal benefits such as integration of more renewables, reduced emissions and improved utilization of grid assets. A power-pool model which incorporates the one-sided auction market into POPF is developed. The model considers storage units as market participants submitting hourly price bids in the form of marginal costs. This provides an accurate market-clearing process as compared to the 'price-taker' analysis available in the literature where the effects of large-scale storage units on the market-clearing prices are neglected. Different case studies are provided to demonstrate our operational-planning framework and economic justification for different storage applications. A new reliability model is proposed for security and adequacy assessment of power networks containing renewable resources and energy storage systems. The proposed model is used in combination with the operational-planning framework to enhance the reliability and operability of wind integration. The proposed framework optimally utilizes the storage capacity for reliability applications of wind integration. This is essential for justification of storage deployment within regulated utilities where the absence of market opportunities limits the economic advantage of storage technologies over gas-fired generators. A control strategy is also proposed to achieve the maximum reliability using energy storage systems. A cost-benefit analysis compares storage technologies and conventional alternatives to reliably and efficiently integrate different wind penetrations and determines the most economical design. Our simulation results demonstrate the necessity of optimal storage placement for different wind applications. This dissertation also proposes a new stochastic framework to optimally charge and discharge electric vehicles (EVs) to mitigate the effects of wind power uncertainties. Vehicle-to-grid (V2G) service for hedging against wind power imbalances is introduced as a novel application for EVs. This application enhances the predictability of wind power and reduces the power imbalances between the scheduled output and actual power. An Auto Regressive Moving Average (ARMA) wind speed model is developed to forecast the wind power output. Driving patterns of EVs are stochastically modeled and the EVs are clustered in the fleets of similar daily driving patterns. Monte Carlo Simulation (MCS) simulates the system behavior by generating samples of system states using the wind ARMA model and EVs driving patterns. A Genetic Algorithm (GA) is used in combination with MCS to optimally coordinate the EV fleets for their V2G services and minimize the penalty cost associated with wind power imbalances. The economic characteristics of automotive battery technologies and costs of V2G service are incorporated into a cost-benefit analysis which evaluates the economic justification of the proposed V2G application. Simulation results demonstrate that the developed algorithm enhances wind power utilization and reduces the penalty cost for wind power under-/over-production. This offers potential revenues for the wind producer. Our cost-benefit analysis also demonstrates that the proposed algorithm will provide the EV owners with economic incentives to participate in V2G services. The proposed smart scheduling strategy develops a sustainable integrated electricity and transportation infrastructure.

Studies of the cosmic ray energy spectrum and chemical composition at 1016 - 1018 eV with the KASCADE-Grande experiment

NASA Astrophysics Data System (ADS)

KASCADE-Grande Collaboration; Cantoni, E.; Apel, W. D.; Arteaga-Velázquez, J. C.; Bekk, K.; Bertaina, M.; Blüumer, J.; Bozdog, H.; Brancus, I. M.; Buchholz, P.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Mayer, H. J.; Melissas, M.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.

The KASCADE-Grande experiment operates at Karlsruhe Institute of Technology (KIT) in Germany. It's aim is the study of the primary cosmic radiation, through Extensive Air Shower detection, in the range 1016 - 1018 eV. In this contribution, KASCADE-Grande recent results will be shown, especially drawing the attention on the measurement of the cosmic ray energy spectrum.

Density-Functional-Theory Modeling of Cation Diffusion in Bulk La 1 - x Sr x MnO 3 ± δ ( x = 0.0 – 0.25 ) for Solid-Oxide Fuel-Cell Cathodes

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

Lee, Yueh-Lin; Duan, Yuhua; Morgan, Dane

In this work, the A - and B -site cation migration pathways involving defect complexes in bulk La 1-xSr xMnO 3±δ (LSM) at x = 0.0-0.25 are investigated based on density-functional-theory modeling for solid-oxide fuel-cell (SOFC) cathode applications. We propose a dominant A -site cation migration mechanism which involves an A -site cation (e.g., Lamore » $$x\\atop{A}$$) V A"' of a V A"' -V B"' cluster, where La$$x\\atop{A}$$, V A"' and V B"' are La 3+, A-site vacancy, and B-site vacancy in bulk LSM, respectively, and V A"' -V B"' is the first nearest-neighbor V A"' and V B"' pair. This hop exhibits an approximately 1.6-eV migration barrier as compared to approximately 2.9 eV of the La$$x\\atop{A}$$ hop into a V A"'. This decrease in the cation migration barrier is attributed to the presence of the V B"' relieving the electrostatic repulsion and steric constraints to the migrating A-site cations in the transition-state image configurations.« less

Density-Functional-Theory Modeling of Cation Diffusion in Bulk La 1 - x Sr x MnO 3 ± δ ( x = 0.0 – 0.25 ) for Solid-Oxide Fuel-Cell Cathodes

DOE PAGES

Lee, Yueh-Lin; Duan, Yuhua; Morgan, Dane; ...

2017-10-04

In this work, the A - and B -site cation migration pathways involving defect complexes in bulk La 1-xSr xMnO 3±δ (LSM) at x = 0.0-0.25 are investigated based on density-functional-theory modeling for solid-oxide fuel-cell (SOFC) cathode applications. We propose a dominant A -site cation migration mechanism which involves an A -site cation (e.g., Lamore » $$x\\atop{A}$$) V A"' of a V A"' -V B"' cluster, where La$$x\\atop{A}$$, V A"' and V B"' are La 3+, A-site vacancy, and B-site vacancy in bulk LSM, respectively, and V A"' -V B"' is the first nearest-neighbor V A"' and V B"' pair. This hop exhibits an approximately 1.6-eV migration barrier as compared to approximately 2.9 eV of the La$$x\\atop{A}$$ hop into a V A"'. This decrease in the cation migration barrier is attributed to the presence of the V B"' relieving the electrostatic repulsion and steric constraints to the migrating A-site cations in the transition-state image configurations.« less

Concentration dependence of Li+/Na+ diffusion in manganese hexacyanoferrates

NASA Astrophysics Data System (ADS)

Takachi, Masamitsu; Fukuzumi, Yuya; Moritomo, Yutaka

2016-06-01

Manganese hexacyanoferrates (Mn-HCFs) with a jungle-gym-type structure are promising cathode materials for Li+/Na+ secondary batteries (LIBs/SIBs). Here, we investigated the diffusion constants D Li/D Na of Li+/Na+ against the Li+/Na+ concentration x Na/x Li and temperature (T) of A 1.32Mn[Fe(CN)6]0.833.6H2O (A = Li and Na). We evaluated the activation energy E\\text{a}\\text{Li}/E\\text{a}\\text{Na} of D Li/D Na against x Na/x Li. We found that E\\text{a}\\text{Na} steeply increases with x Na from 0.41 eV at x Na = 0.69 to 0.7 eV at 1.1. The increase in E\\text{a}\\text{Na} is ascribed to the occupancy effect of the Na+ site. The increase in E\\text{a}\\text{Li} is suppressed, probably because the number of Li+ sites is three times that of Na+ sites.

Performance test of Ti/Au bilayer TES microcalorimeter in combination with continuous ADR

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

Ishisaki, Y.; Akamatsu, H.; Hoshino, A.

2009-12-16

Performance test of a Ti/Au bilayer TES microcalorimeter has been made in combination with a continuous adiabatic demagnetization refrigerator (CADR). The CADR has four stages of ADR to produce continuous cooling by recycling them in dedicated order, and is cryogen-free utilizing a 4K-GM refrigerator. We installed a Ti/Au bilayer TES microcalorimeter and 420-series SQUID array to readout the X-ray signal on the 1st (coldest) stage of the CADR. We successfully operated the CADR at temperature of 120 mK in continuous mode more than 27 hr, however, FWHM energy resolution of the TES microcalorimeter was degraded to 45 eV at 6more » keV, as compared to 10 eV when measured in a dilution refrigerator. This is mainly because the temperature stability was not good enough (about 0.6 mK) and the operation temperature was not sufficiently lower than the transition temperature T{sub c} = 135mK of the TES. We operated the TES microcalorimeter at the operation temperature of 105 mK in one-shot mode and the resolution was improved to 30 eV. We also found that the operating point of the TES was affected by the magnetic field of the 3rd and 4th ADR recycle. More complete shielding of the magnetic field is essential for further improvement of the performance of the TES microcalorimeter.« less

SAND FLIES (DIPTERA: PSYCHODIDAE) IN AN ENDEMIC AREA OF LEISHMANIASIS IN AQUIDAUANA MUNICIPALITY, PANTANAL OF MATO GROSSO DO SUL , BRAZIL

PubMed Central

de FIGUEIREDO, Helen Rezende; SANTOS, Mirella Ferreira da Cunha; CASARIL, Aline Etelvina; INFRAN, Jucelei Oliveira de Moura; RIBEIRO, Leticia Moraes; FERNANDES, Carlos Eurico dos Santos; de OLIVEIRA, Alessandra Gutierrez

2016-01-01

SUMMARY The Aquidauana municipality is considered an endemic area of leishmaniasis and an important tourist site in Mato Grosso do Sul State. The aim of this study was to investigate the sand fly fauna in the city of Aquidauana. Captures were carried out twice a month, from April 2012 to March 2014 with automatic light traps and active aspiration, in the peridomicile and domicile of six residences. A total of 9,338 specimens were collected, 3,179 and 6,159 using light traps and active aspiration, respectively. The fauna consisted of: Brumptomyia brumpti, Evandromyia aldafalcaoae, Ev. evandroi, Ev. lenti, Ev. orcyi, Ev. sallesi, Ev. termitophila, Ev. walkeri, Lutzomyia longipalpis and Psathyromyia bigeniculata. The most abundant species captured was Lutzomyia longipalpis, present in all the ecotopes, predominantly in peridomicile areas, and mainly males. Leishmania DNA was not detected in the insects. It was observed the abundance of the sand fly fauna in the region, as well as the high frequency of Lu. longipalpis, the main vector of L. infantum. The results of this study show the need to increase the monitoring and more effective control measures. It is noteworthy that the studied region presents several activities related to tourism and recreation, increasing the risk of transmission of leishmaniasis to this particular human population. PMID:27982353

The Extracellular Vesicles of the Helminth Pathogen, Fasciola hepatica: Biogenesis Pathways and Cargo Molecules Involved in Parasite Pathogenesis*

PubMed Central

Cwiklinski, Krystyna; de la Torre-Escudero, Eduardo; Trelis, Maria; Bernal, Dolores; Dufresne, Philippe J.; Brennan, Gerard P.; O'Neill, Sandra; Tort, Jose; Paterson, Steve; Marcilla, Antonio; Dalton, John P.; Robinson, Mark W.

2015-01-01

Extracellular vesicles (EVs) released by parasites have important roles in establishing and maintaining infection. Analysis of the soluble and vesicular secretions of adult Fasciola hepatica has established a definitive characterization of the total secretome of this zoonotic parasite. Fasciola secretes at least two subpopulations of EVs that differ according to size, cargo molecules and site of release from the parasite. The larger EVs are released from the specialized cells that line the parasite gastrodermus and contain the zymogen of the 37 kDa cathepsin L peptidase that performs a digestive function. The smaller exosome-like vesicle population originate from multivesicular bodies within the tegumental syncytium and carry many previously described immunomodulatory molecules that could be delivered into host cells. By integrating our proteomics data with recently available transcriptomic data sets we have detailed the pathways involved with EV biogenesis in F. hepatica and propose that the small exosome biogenesis occurs via ESCRT-dependent MVB formation in the tegumental syncytium before being shed from the apical plasma membrane. Furthermore, we found that the molecular “machinery” required for EV biogenesis is constitutively expressed across the intramammalian development stages of the parasite. By contrast, the cargo molecules packaged within the EVs are developmentally regulated, most likely to facilitate the parasites migration through host tissue and to counteract host immune attack. PMID:26486420

Ratio of platelet count/spleen diameter predicted the presence of esophageal varices in patients with schistosomiasis liver cirrhosis.

PubMed

Xu, Xiao-Dan; Xu, Chun-Fang; Dai, Jian-Jun; Qian, Jian-Qing; Pin, Xun

2016-05-01

To examine the platelet count (PC)/spleen diameter (SD) ratio in predicting the presence of esophageal varices (EV) in patients with schistosomiasis liver cirrhosis. A total of 95 consecutive patients with EV induced by schistosomiasis liver cirrhosis were enrolled in this trial. A total of 141 schistosomiasis liver cirrhosis patients without EV were enrolled as controls. All patients were diagnosed by endoscopy. Demographic, laboratory, and Doppler ultrasound parameters were collected and analyzed. Binary logistic regression analysis was carried out to identify independent risk factors associated with EV occurrence. Receiver operating curves were generated to obtain the PC/SD ratio cutoff values for the optimal sensitivity and specificity with respect to EV. The accuracy was increased in diagnosing for EV using the ratio of PC/SD compared with the SD alone [area under the curve: 0.891 95% confidence interval (CI): 0.844-0.928 vs. 0.764 95% CI: 0.705-0.817; P<0.01]. The optimal cutoff value was 1004, with a 77.1% (95% CI: 67.9-84.8%) positive-predictive value and an 89.3% (95% CI: 82.7-94.0%) negative-predictive value. Using a cutoff of 1004, it was determined that 117/141 (83.0%) patients without EV could avoid undergoing unnecessary endoscopy, whereas 14/95 (14.7%) patients with EV would be misdiagnosed. In contrast, when the ratio was set at 909, the positive-predictive and negative-predictive values were 79.5% (95% CI: 69.5-87.4%) and 83.1% (95% CI: 76.1-88.8%), respectively. A ratio of 909 would accurately predict the absence of EV in 123/141 (87.2%) patients; however, 24/95 (25.3%) patients with EV would miss the necessary screening endoscopy. The ratio of PC/SD was a useful marker in predicting the presence of EV in patients with schistosomiasis liver cirrhosis.

caCORE: a common infrastructure for cancer informatics.

PubMed

Covitz, Peter A; Hartel, Frank; Schaefer, Carl; De Coronado, Sherri; Fragoso, Gilberto; Sahni, Himanso; Gustafson, Scott; Buetow, Kenneth H

2003-12-12

Sites with substantive bioinformatics operations are challenged to build data processing and delivery infrastructure that provides reliable access and enables data integration. Locally generated data must be processed and stored such that relationships to external data sources can be presented. Consistency and comparability across data sets requires annotation with controlled vocabularies and, further, metadata standards for data representation. Programmatic access to the processed data should be supported to ensure the maximum possible value is extracted. Confronted with these challenges at the National Cancer Institute Center for Bioinformatics, we decided to develop a robust infrastructure for data management and integration that supports advanced biomedical applications. We have developed an interconnected set of software and services called caCORE. Enterprise Vocabulary Services (EVS) provide controlled vocabulary, dictionary and thesaurus services. The Cancer Data Standards Repository (caDSR) provides a metadata registry for common data elements. Cancer Bioinformatics Infrastructure Objects (caBIO) implements an object-oriented model of the biomedical domain and provides Java, Simple Object Access Protocol and HTTP-XML application programming interfaces. caCORE has been used to develop scientific applications that bring together data from distinct genomic and clinical science sources. caCORE downloads and web interfaces can be accessed from links on the caCORE web site (http://ncicb.nci.nih.gov/core). caBIO software is distributed under an open source license that permits unrestricted academic and commercial use. Vocabulary and metadata content in the EVS and caDSR, respectively, is similarly unrestricted, and is available through web applications and FTP downloads. http://ncicb.nci.nih.gov/core/publications contains links to the caBIO 1.0 class diagram and the caCORE 1.0 Technical Guide, which provide detailed information on the present caCORE architecture, data sources and APIs. Updated information appears on a regular basis on the caCORE web site (http://ncicb.nci.nih.gov/core).

A Comparative Study of Power Supply Architectures In Wireless Electric Vehicle Charging Systems

NASA Astrophysics Data System (ADS)

Esteban, Bryan

Wireless inductive power transfer is a transformational and disruptive technology that enables the reliable and efficient transfer of electrical power over large air gaps for a host of unique applications. One such application that is now gaining much momentum worldwide is the wireless charging of electric vehicles (EVs). This thesis examines two of the primary power supply topologies being predominantly used for EV charging, namely the SLC and the LCL resonant full bridge inverter topologies. The study of both of these topologies is presented in the context of designing a 3 kW, primary side controlled, wireless EV charger with nominal operating parameters of 30 kHz centre frequency and range of coupling in the neighborhood of .18-.26. A comparison of both topologies is made in terms of their complexity, cost, efficiency, and power quality. The aim of the study is to determine which topology is better for wireless EV charging.

Part-Task Simulation of Synthetic and Enhanced Vision Concepts for Lunar Landing

NASA Technical Reports Server (NTRS)

Arthur, Jarvis J., III; Bailey, Randall E.; Jackson, E. Bruce; Williams, Steven P.; Kramer, Lynda J.; Barnes, James R.

2010-01-01

During Apollo, the constraints placed by the design of the Lunar Module (LM) window for crew visibility and landing trajectory were a major problem. Lunar landing trajectories were tailored to provide crew visibility using nearly 70 degrees look-down angle from the canted LM windows. Apollo landings were scheduled only at specific times and locations to provide optimal sunlight on the landing site. The complications of trajectory design and crew visibility are still a problem today. Practical vehicle designs for lunar lander missions using optimal or near-optimal fuel trajectories render the natural vision of the crew from windows inadequate for the approach and landing task. Further, the sun angles for the desirable landing areas in the lunar polar regions create visually powerful, season-long shadow effects. Fortunately, Synthetic and Enhanced Vision (S/EV) technologies, conceived and developed in the aviation domain, may provide solutions to this visibility problem and enable additional benefits for safer, more efficient lunar operations. Piloted simulation evaluations have been conducted to assess the handling qualities of the various lunar landing concepts, including the influence of cockpit displays and the informational data and formats. Evaluation pilots flew various landing scenarios with S/EV displays. For some of the evaluation trials, an eye glasses-mounted, monochrome monocular display, coupled with head tracking, was worn. The head-worn display scene consisted of S/EV fusion concepts. The results of this experiment showed that a head-worn system did not increase the pilot s workload when compared to using just the head-down displays. As expected, the head-worn system did not provide an increase in performance measures. Some pilots commented that the head-worn system provided greater situational awareness compared to just head-down displays.

Part-task simulation of synthetic and enhanced vision concepts for lunar landing

NASA Astrophysics Data System (ADS)

Arthur, Jarvis J., III; Bailey, Randall E.; Jackson, E. Bruce; Barnes, James R.; Williams, Steven P.; Kramer, Lynda J.

2010-04-01

During Apollo, the constraints placed by the design of the Lunar Module (LM) window for crew visibility and landing trajectory were "a major problem." Lunar landing trajectories were tailored to provide crew visibility using nearly 70 degrees look-down angle from the canted LM windows. Apollo landings were scheduled only at specific times and locations to provide optimal sunlight on the landing site. The complications of trajectory design and crew visibility are still a problem today. Practical vehicle designs for lunar lander missions using optimal or near-optimal fuel trajectories render the natural vision of the crew from windows inadequate for the approach and landing task. Further, the sun angles for the desirable landing areas in the lunar polar regions create visually powerful, season-long shadow effects. Fortunately, Synthetic and Enhanced Vision (S/EV) technologies, conceived and developed in the aviation domain, may provide solutions to this visibility problem and enable additional benefits for safer, more efficient lunar operations. Piloted simulation evaluations have been conducted to assess the handling qualities of the various lunar landing concepts, including the influence of cockpit displays and the informational data and formats. Evaluation pilots flew various landing scenarios with S/EV displays. For some of the evaluation trials, an eye glasses-mounted, monochrome monocular display, coupled with head tracking, was worn. The head-worn display scene consisted of S/EV fusion concepts. The results of this experiment showed that a head-worn system did not increase the pilot's workload when compared to using just the head-down displays. As expected, the head-worn system did not provide an increase in performance measures. Some pilots commented that the head-worn system provided greater situational awareness compared to just head-down displays.

Building a Quality Controlled Database of Meteorological Data from NASA Kennedy Space Center and the United States Air Force's Eastern Range

NASA Technical Reports Server (NTRS)

Brenton, James C.; Barbre. Robert E., Jr.; Decker, Ryan K.; Orcutt, John M.

2018-01-01

The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) Natural Environments Branch (EV44) has provided atmospheric databases and analysis in support of space vehicle design and day-of-launch operations for NASA and commercial launch vehicle programs launching from the NASA Kennedy Space Center (KSC), co-located on the United States Air Force's Eastern Range (ER) at the Cape Canaveral Air Force Station. The ER complex is one of the most heavily instrumented sites in the United States with over 31 towers measuring various atmospheric parameters on a continuous basis. An inherent challenge with large sets of data consists of ensuring erroneous data is removed from databases, and thus excluded from launch vehicle design analyses. EV44 has put forth great effort in developing quality control (QC) procedures for individual meteorological instruments, however no standard QC procedures for all databases currently exists resulting in QC databases that have inconsistencies in variables, methodologies, and periods of record. The goal of this activity is to use the previous efforts by EV44 to develop a standardized set of QC procedures from which to build meteorological databases from KSC and the ER, while maintaining open communication with end users from the launch community to develop ways to improve, adapt and grow the QC database. Details of the QC procedures will be described. As the rate of launches increases with additional launch vehicle programs, it is becoming more important that weather databases are continually updated and checked for data quality before use in launch vehicle design and certification analyses.

The glycoprotein TRP36 of Ehrlichia sp. UFMG-EV and related cattle pathogen Ehrlichia sp. UFMT-BV evolved from a highly variable clade of E. canis under adaptive diversifying selection.

PubMed

Cabezas-Cruz, Alejandro; Valdés, James J; de la Fuente, José

2014-12-10

A new species of Ehrlichia, phylogenetically distant from E. ruminantium, was found in 2010 infecting cattle in Canada. In 2012 and 2013, we reported the in vitro propagation, molecular and ultrastructural characterization of Ehrlichia sp. UFMG-EV (E. mineirensis), a new species of Ehrlichia isolated from the haemolymph of Brazilian Rhipicephalus (Boophilus) microplus ticks. A new organism, named Ehrlichia sp. UFMT-BV, closely related to Ehrlichia sp. UFMG-EV, was recently described in Brazil and after experimental infection it was shown to be pathogenic for cattle. This new emerging clade of cattle Ehrlichia pathogens is closely related to E. canis. The major immunogenic Tandem Repeat Protein (TRP36; also known as gp36) is extensively used to characterize the genetic diversity of E. canis. Homologs of TRP36 were found in both Ehrlichia sp. UFMG-EV and Ehrlichia sp. UFMT-BV. Herein, we characterized the evolution of this new Ehrlichia clade using TRP36 sequences. Our working hypothesis is that Ehrlichia sp. UFMG-EV and related microorganisms evolved from a highly variable E. canis clade. In support of our hypothesis we found that Ehrlichia sp. UFMG-EV and Ehrlichia sp. UFMT-BV TRP36 evolved from a highly divergent and variable clade within E. canis and this clade evolved under episodic diversifying selection with a high proportion of sites under positive selection. Our results suggest that Ehrlichia sp. UFMG-EV and Ehrlichia sp. UFMT-BV evolved from a variable clade within E. canis.

Left gastric vein-based noninvasive test for esophageal varices: a same-day comparison of portal hemodynamic assessment with endoscopic appearance.

PubMed

Maruyama, Hitoshi; Kobayashi, Kazufumi; Kiyono, Soichiro; Ogasawara, Sadahisa; Ooka, Yoshihiko; Suzuki, Eiichiro; Chiba, Tetsuhiro; Kato, Naoya

2018-05-25

To examine the effect of hemodynamic assessment of the left gastric vein (LGV) as a noninvasive test to diagnose esophageal varices (EV) in cirrhosis patients. This cross-sectional study consisted of 229 cirrhosis patients (62.7 ± 11.8 years; Child-Pugh score 5-14). One hundred fifty-four patients had EV (67.2%; small, 53; medium, 71; large, 30). All patients underwent a blood test and Doppler ultrasound followed by upper gastrointestinal endoscopy on the same day. The diagnostic ability for EV was compared between LGV-related findings and the platelet count/spleen diameter ratio (Plt/Spl). The detectability of the LGV was higher in patients with EV (129/144, 89.6%) than in those without (35/75, 46.7%; p < 0.0001), and was higher in those with large EV (30/30, 100%) than in those without (134/199, 67.3%; p = 0.0002). The positive detection of the LGV showed 100% sensitivity and negative predictive value (NPV) to identify large EV in the whole cohort and compensated group (n = 127). The best cutoff value in the LGV diameter was 5.35 mm to identify large EV, showing 0.753 area under the receiver operating characteristic curve (AUROC) with 90% sensitivity and 96.5% NPV. The Plt/Spl showed 62.1% sensitivity and 87.1% NPV, and the best cutoff value was 442.9 to identify large EV with 0.658 AUROC, which was comparable to LGV-based assessment (p = 0.162). This same-day comparison study demonstrated the value of LGV-based noninvasive test to identify large EV with high sensitivity and NPV in cirrhosis patients at a lower cost.

Enterovirus 71 Inhibits Pyroptosis through Cleavage of Gasdermin D

PubMed Central

Lei, Xiaobo; Zhang, Zhenzhen; Xiao, Xia; Qi, Jianli

2017-01-01

ABSTRACT Enterovirus 71 (EV71) can cause hand-foot-and-mouth disease (HFMD) in young children. Severe infection with EV71 can lead to neurological complications and even death. However, the molecular basis of viral pathogenesis remains poorly understood. Here, we report that EV71 induces degradation of gasdermin D (GSDMD), an essential component of pyroptosis. Remarkably, the viral protease 3C directly targets GSDMD and induces its cleavage, which is dependent on the protease activity. Further analyses show that the Q193-G194 pair within GSDMD is the cleavage site of 3C. This cleavage produces a shorter N-terminal fragment spanning amino acids 1 to 193 (GSDMD1–193). However, unlike the N-terminal fragment produced by caspase-1 cleavage, this fragment fails to trigger cell death or inhibit EV71 replication. Importantly, a T239D or F240D substitution abrogates the activity of GSDMD consisting of amino acids 1 to 275 (GSDMD1–275). This is correlated with the lack of pyroptosis or inhibition of viral replication. These results reveal a previously unrecognized strategy for EV71 to evade the antiviral response. IMPORTANCE Recently, it has been reported that GSDMD plays a critical role in regulating lipopolysaccharide and NLRP3-mediated interleukin-1β (IL-1β) secretion. In this process, the N-terminal domain of p30 released from GSDMD acts as an effector in cell pyroptosis. We show that EV71 infection downregulates GSDMD. EV71 3C cleaves GSDMD at the Q193-G194 pair, resulting in a truncated N-terminal fragment disrupted for inducing cell pyroptosis. Notably, GSDMD1–275 (p30) inhibits EV71 replication whereas GSDMD1–193 does not. These results reveal a new strategy for EV71 to evade the antiviral response. PMID:28679757

Enterovirus 71 Inhibits Pyroptosis through Cleavage of Gasdermin D.

PubMed

Lei, Xiaobo; Zhang, Zhenzhen; Xiao, Xia; Qi, Jianli; He, Bin; Wang, Jianwei

2017-09-15

Enterovirus 71 (EV71) can cause hand-foot-and-mouth disease (HFMD) in young children. Severe infection with EV71 can lead to neurological complications and even death. However, the molecular basis of viral pathogenesis remains poorly understood. Here, we report that EV71 induces degradation of gasdermin D (GSDMD), an essential component of pyroptosis. Remarkably, the viral protease 3C directly targets GSDMD and induces its cleavage, which is dependent on the protease activity. Further analyses show that the Q193-G194 pair within GSDMD is the cleavage site of 3C. This cleavage produces a shorter N-terminal fragment spanning amino acids 1 to 193 (GSDMD 1-193 ). However, unlike the N-terminal fragment produced by caspase-1 cleavage, this fragment fails to trigger cell death or inhibit EV71 replication. Importantly, a T239D or F240D substitution abrogates the activity of GSDMD consisting of amino acids 1 to 275 (GSDMD 1-275 ). This is correlated with the lack of pyroptosis or inhibition of viral replication. These results reveal a previously unrecognized strategy for EV71 to evade the antiviral response. IMPORTANCE Recently, it has been reported that GSDMD plays a critical role in regulating lipopolysaccharide and NLRP3-mediated interleukin-1β (IL-1β) secretion. In this process, the N-terminal domain of p30 released from GSDMD acts as an effector in cell pyroptosis. We show that EV71 infection downregulates GSDMD. EV71 3C cleaves GSDMD at the Q193-G194 pair, resulting in a truncated N-terminal fragment disrupted for inducing cell pyroptosis. Notably, GSDMD 1-275 (p30) inhibits EV71 replication whereas GSDMD 1-193 does not. These results reveal a new strategy for EV71 to evade the antiviral response. Copyright © 2017 American Society for Microbiology.

Enterovirus D68 in Viet Nam (2009-2015).

PubMed

Ny, Nguyen Thi Han; Anh, Nguyen To; Hang, Vu Thi Ty; Nguyet, Lam Anh; Thanh, Tran Tan; Ha, Do Quang; Minh, Ngo Ngoc Quang; Ha, Do Lien Anh; McBride, Angela; Tuan, Ha Manh; Baker, Stephen; Tam, Pham Thi Thanh; Phuc, Tran My; Huong, Dang Thao; Loi, Tran Quoc; Vu, Nguyen Tran Anh; Hung, Nguyen Van; Minh, Tran Thi Thuy; Xang, Nguyen Van; Dong, Nguyen; Nghia, Ho Dang Trung; Chau, Nguyen Van Vinh; Thwaites, Guy; van Doorn, H Rogier; Anscombe, Catherine; Le Van, Tan

2017-01-01

Since 1962, enterovirus D68 (EV-D68) has been implicated in multiple outbreaks and sporadic cases of respiratory infection worldwide, but especially in the USA and Europe with an increasing frequency between 2010 and 2014. We describe the detection, associated clinical features and molecular characterization of EV-D68 in central and southern Viet Nam between 2009 and 2015. Enterovirus/rhinovirus PCR positive respiratory or CSF samples taken from children and adults with respiratory/central nervous system infections in Viet Nam were tested by an EV-D68 specific PCR. The included samples were derived from 3 different observational studies conducted at referral hospitals across central and southern Viet Nam between 2009 and 2015. Whole-genome sequencing was carried out using a MiSeq based approach. Phylogenetic reconstruction and estimation of evolutionary rate and recombination were carried out in BEAST and Recombination Detection Program, respectively. EV-D68 was detected in 21/625 (3.4%) enterovirus/rhinovirus PCR positive respiratory samples but in none of the 15 CSF. All the EV-D68 patients were young children (age range: 11.8 - 24.5 months) and had moderate respiratory infections. Phylogenetic analysis suggested that the Vietnamese sequences clustered with those from Asian countries, of which 9 fell in the B1 clade, and the remaining sequence was identified within the A2 clade. One intra sub-clade recombination event was detected, representing the second reported recombination within EV-D68. The evolutionary rate of EV-D68 was estimated to be 5.12E -3 substitutions/site/year. Phylogenetic analysis indicated that the virus was imported into Viet Nam in 2008. We have demonstrated for the first time EV-D68 has been circulating at low levels in Viet Nam since 2008, associated with moderate acute respiratory infection in children. EV-D68 in Viet Nam is most closely related to Asian viruses, and clusters separately from recent US and European viruses that were suggested to be associated with acute flaccid paralysis.

Thermionic modules

DOEpatents

King, Donald B.; Sadwick, Laurence P.; Wernsman, Bernard R.

2002-06-18

Modules of assembled microminiature thermionic converters (MTCs) having high energy-conversion efficiencies and variable operating temperatures manufactured using MEMS manufacturing techniques including chemical vapor deposition. The MTCs incorporate cathode to anode spacing of about 1 micron or less and use cathode and anode materials having work functions ranging from about 1 eV to about 3 eV. The MTCs also exhibit maximum efficiencies of just under 30%, and thousands of the devices and modules can be fabricated at modest costs.

High School Parking Lots.

ERIC Educational Resources Information Center

Neff, Thomas G.

2002-01-01

Describes the reorganization of the site of Ben Davis High School in Wayne Township, Indiana as an example of improvements to school parking lot design and vehicle/pedestrian traffic flow and security. Includes design drawings. (EV)

Electric Vehicle Sharing Planning and Operations

DOT National Transportation Integrated Search

2018-02-01

Dongfang Zhao (ORCID ID 0000-0002-5424-9915); Xiaopeng (Shaw) Li (ORCID ID 0000-0002-5264-3775); Yu Zhang (ORCID ID 0000-0003-1202-626X) This project includes literature review and proposing a model for EV planning and operations. We first conducted ...

Effect of multinary substitution on electronic and transport properties of TiCoSb based half-Heusler alloys

NASA Astrophysics Data System (ADS)

Choudhary, Mukesh K.; Ravindran, P.

2018-05-01

The electronic structures of TixZrx/2CoPbxTex, TixZrx/2Hfx/2CoPbxTex (x = 0.5), and the parent compound TiCoSb were investigated using the full potential linearized augmented plane wave method. The thermoelectric transport properties of these alloys are calculated on the basis of semi-classical Boltzmann transport theory. From the band structure calculations we show that the substitution of Zr,Hf in the Ti site and Pb and Te in the Sb site lower the band gap value and also change the indirect band (IB) gap of TiCoSb to the direct band (DB) gap. The calculated band gap of TiCoSb, TixZrx/2CoPbxTex, and TixZrx/2Hfx/2CoPbxTex are 1.04 eV (IB), 0.92 eV (DB), and 0.93 eV (DB), respectively. All these alloys follow the empirical rule of 18 valence-electron content which is essential for bringing semiconductivity in half Heusler alloys. It is shown that the substitution of Hf at the Ti site improve the ZT value (˜1.05) at room temperature, whereas there is no significant difference in ZT is found at higher temperature. Based on the calculated thermoelectric transport properties, we conclude that the appropriate concentration of Hf substitution can further improve the thermoelectric performance of TixZrx/2Hfx/2CoPbxTex.

Global Distribution and Evolutionary History of Enterovirus D68, with Emphasis on the 2014 Outbreak in Ontario, Canada.

PubMed

Eshaghi, Alireza; Duvvuri, Venkata R; Isabel, Sandra; Banh, Philip; Li, Aimin; Peci, Adriana; Patel, Samir N; Gubbay, Jonathan B

2017-01-01

Despite its first appearance in 1962, human enterovirus D68 (EV-D68) has been recognized as an emerging respiratory pathogen in the last decade when it caused outbreaks and clusters in several countries including Japan, the Philippines, and the Netherlands. The most recent and largest outbreak of EV-D68 associated with severe respiratory illness took place in North America between August 2014 and January 2015. Between September 1 and October 31 2014, EV-D68 infection was laboratory confirmed among 153/907 (16.9%) persons tested for the virus in Ontario, Canada, using real time RT-PCR and subsequent genotyping by sequencing of partial VP1 gene. In order to understand the evolutionary history of the 2014 North American EV-D68 outbreak, we conducted phylogenetic and phylodynamic analyses using available partial VP1 genes ( n = 469) and NCBI available whole genome sequences (WGS) ( n = 38). The global EV-D68 phylogenetic tree ( n = 469) reconfirms the divergence of three distinct clades A, B, and C from the prototype EV-D68 Fermon strain as previously documented. Two sub-clades (B1 and B2) were identified, with most 2014 EV-D68 outbreak strains belonging to sub-cluster B2b2 (one of the two emerging clusters within sub-clade B2), with two signature substitutions T650A and M700V in BC and DE loops of VP1 gene, respectively. The close homology between WGS of strains from Ontario ( n = 2) and USA ( n = 21) in the recent EV-D68 outbreak suggests genetic relatedness and also a common source for the outbreak. The time of most recent common ancestor of EV-D68 and the 2014 EV-D68 outbreak strain suggest that the viruses possibly emerged during 1960-1961 and 2012-2013, respectively. We observed lower mean evolutionary rates of global EV-D68 using WGS data than estimated with partial VP1 gene sequences. Based on WGS data, the estimated mean rate of evolution of the EV-D68 B2b cluster was 9.75 × 10 -3 substitutions/site/year (95% BCI 4.11 × 10 -3 to 16 × 10 -3 ).

Global Distribution and Evolutionary History of Enterovirus D68, with Emphasis on the 2014 Outbreak in Ontario, Canada

PubMed Central

Eshaghi, Alireza; Duvvuri, Venkata R.; Isabel, Sandra; Banh, Philip; Li, Aimin; Peci, Adriana; Patel, Samir N.; Gubbay, Jonathan B.

2017-01-01

Despite its first appearance in 1962, human enterovirus D68 (EV-D68) has been recognized as an emerging respiratory pathogen in the last decade when it caused outbreaks and clusters in several countries including Japan, the Philippines, and the Netherlands. The most recent and largest outbreak of EV-D68 associated with severe respiratory illness took place in North America between August 2014 and January 2015. Between September 1 and October 31 2014, EV-D68 infection was laboratory confirmed among 153/907 (16.9%) persons tested for the virus in Ontario, Canada, using real time RT-PCR and subsequent genotyping by sequencing of partial VP1 gene. In order to understand the evolutionary history of the 2014 North American EV-D68 outbreak, we conducted phylogenetic and phylodynamic analyses using available partial VP1 genes (n = 469) and NCBI available whole genome sequences (WGS) (n = 38). The global EV-D68 phylogenetic tree (n = 469) reconfirms the divergence of three distinct clades A, B, and C from the prototype EV-D68 Fermon strain as previously documented. Two sub-clades (B1 and B2) were identified, with most 2014 EV-D68 outbreak strains belonging to sub-cluster B2b2 (one of the two emerging clusters within sub-clade B2), with two signature substitutions T650A and M700V in BC and DE loops of VP1 gene, respectively. The close homology between WGS of strains from Ontario (n = 2) and USA (n = 21) in the recent EV-D68 outbreak suggests genetic relatedness and also a common source for the outbreak. The time of most recent common ancestor of EV-D68 and the 2014 EV-D68 outbreak strain suggest that the viruses possibly emerged during 1960–1961 and 2012–2013, respectively. We observed lower mean evolutionary rates of global EV-D68 using WGS data than estimated with partial VP1 gene sequences. Based on WGS data, the estimated mean rate of evolution of the EV-D68 B2b cluster was 9.75 × 10-3 substitutions/site/year (95% BCI 4.11 × 10-3 to 16 × 10-3). PMID:28298902

Generating circularly polarized radiation in the extreme ultraviolet spectral range at the free-electron laser FLASH

NASA Astrophysics Data System (ADS)

von Korff Schmising, Clemens; Weder, David; Noll, Tino; Pfau, Bastian; Hennecke, Martin; Strüber, Christian; Radu, Ilie; Schneider, Michael; Staeck, Steffen; Günther, Christian M.; Lüning, Jan; Merhe, Alaa el dine; Buck, Jens; Hartmann, Gregor; Viefhaus, Jens; Treusch, Rolf; Eisebitt, Stefan

2017-05-01

A new device for polarization control at the free electron laser facility FLASH1 at DESY has been commissioned for user operation. The polarizer is based on phase retardation upon reflection off metallic mirrors. Its performance is characterized in three independent measurements and confirms the theoretical predictions of efficient and broadband generation of circularly polarized radiation in the extreme ultraviolet spectral range from 35 eV to 90 eV. The degree of circular polarization reaches up to 90% while maintaining high total transmission values exceeding 30%. The simple design of the device allows straightforward alignment for user operation and rapid switching between left and right circularly polarized radiation.

Mass-dependent channel electron multiplier operation. [for ion detection

NASA Technical Reports Server (NTRS)

Fields, S. A.; Burch, J. L.; Oran, W. A.

1977-01-01

The absolute counting efficiency and pulse height distributions of a continuous-channel electron multiplier used in the detection of hydrogen, argon and xenon ions are assessed. The assessment technique, which involves the post-acceleration of 8-eV ion beams to energies from 100 to 4000 eV, provides information on counting efficiency versus post-acceleration voltage characteristics over a wide range of ion mass. The charge pulse height distributions for H2 (+), A (+) and Xe (+) were measured by operating the experimental apparatus in a marginally gain-saturated mode. It was found that gain saturation occurs at lower channel multiplier operating voltages for light ions such as H2 (+) than for the heavier ions A (+) and Xe (+), suggesting that the technique may be used to discriminate between these two classes of ions in electrostatic analyzers.

Spectrum measurement with the Telescope Array Low Energy Extension (TALE) fluorescence detector

NASA Astrophysics Data System (ADS)

Zundel, Zachary James

The Telescope Array (TA) experiment is the largest Ultra High Energy cosmic ray observatory in the northern hemisphere and is designed to be sensitive to cosmic ray air showers above 1018eV. Despite the substantial measurements made by TA and AUGER (the largest cosmic ray observatory in the southern hemisphere), there remains uncertainty about whether the highest energy cosmic rays are galactic or extragalactic in origin. Locating features in the cosmic ray energy spectrum below 1018eV that indicate a transition from galactic to extragalactic sources would clarify the interpretation of measurements made at the highest energies. The Telescope Array Low Energy Extension (TALE) is designed to extend the energy threshold of the TA observatory down to 1016.5eV in order to make such measurements. This dissertation details the construction, calibration, and operation of the TALE flu- orescence detector. A measurement of the flux of cosmic rays in the energy range of 1016.5 -- 1018.5eV is made using the monocular data set taken between September 2013 and January 2014. The TALE fluorescence detector observes evidence for a softening of the cosmic spectrum at 1017.25+/-0.5eV. The evidence of a change in the spectrum motivates continued study of 1016.5 -- 1018.5eV cosmic rays.

Compact, self-contained enhanced-vision system (EVS) sensor simulator

NASA Astrophysics Data System (ADS)

Tiana, Carlo

2007-04-01

We describe the model SIM-100 PC-based simulator, for imaging sensors used, or planned for use, in Enhanced Vision System (EVS) applications. Typically housed in a small-form-factor PC, it can be easily integrated into existing out-the-window visual simulators for fixed-wing or rotorcraft, to add realistic sensor imagery to the simulator cockpit. Multiple bands of infrared (short-wave, midwave, extended-midwave and longwave) as well as active millimeter-wave RADAR systems can all be simulated in real time. Various aspects of physical and electronic image formation and processing in the sensor are accurately (and optionally) simulated, including sensor random and fixed pattern noise, dead pixels, blooming, B-C scope transformation (MMWR). The effects of various obscurants (fog, rain, etc.) on the sensor imagery are faithfully represented and can be selected by an operator remotely and in real-time. The images generated by the system are ideally suited for many applications, ranging from sensor development engineering tradeoffs (Field Of View, resolution, etc.), to pilot familiarization and operational training, and certification support. The realistic appearance of the simulated images goes well beyond that of currently deployed systems, and beyond that required by certification authorities; this level of realism will become necessary as operational experience with EVS systems grows.

Evaluation of sounds for hybrid and electric vehicles operating at low speed

DOT National Transportation Integrated Search

2012-10-22

Electric vehicles (EV) and hybrid electric vehicles (HEVs), operated at low speeds may reduce auditory cues used by pedestrians to assess the state of nearby traffic creating a safety issue. This field study compares the auditory detectability of num...

Electric vehicle battery durability and reliability under electric utility grid operations.

DOT National Transportation Integrated Search

2017-05-01

Battery degradation is extremely important to EV technologies and is a function of several : factors, such as electrode chemistries, operating temperatures, and usage profiles (i.e. vehicle only : vs. vehicle-to-grid (V2G) applications). The goal of ...

A Modular Vaccine Development Platform Based on Sortase-Mediated Site-Specific Tagging of Antigens onto Virus-Like Particles

PubMed Central

Tang, Shubing; Xuan, Baoqin; Ye, Xiaohua; Huang, Zhong; Qian, Zhikang

2016-01-01

Virus-like particles (VLPs) can be used as powerful nanoscale weapons to fight against virus infection. In addition to direct use as vaccines, VLPs have been extensively exploited as platforms on which to display foreign antigens for prophylactic vaccination and immunotherapeutic treatment. Unfortunately, fabrication of new chimeric VLP vaccines in a versatile, site-specific and highly efficient manner is beyond the capability of traditional VLP vaccine design approaches, genetic insertion and chemical conjugation. In this study, we described a greatly improved VLP display strategy by chemoenzymatic site-specific tailoring antigens on VLPs surface with high efficiency. Through the transpeptidation mediated by sortase A, one protein and two epitopes containing N-terminal oligoglycine were conjugated to the LPET motif on the surface of hepatitis B virus core protein (HBc) VLPs with high density. All of the new chimeric VLPs induced strong specific IgG responses. Furthermore, the chimeric VLPs with sortase A tagged enterovirus 71 (EV71) SP70 epitope could elicit effective antibodies against EV71 lethal challenging as well as the genetic insertion chimeric VLPs. The sortase A mediated chemoenzymatic site-specific tailoring of the HBc VLP approach shows great potential in new VLP vaccine design for its simplicity, site specificity, high efficiency, and versatility. PMID:27170066

A Surge of Anti-Semitism or McCarthyism?

ERIC Educational Resources Information Center

Bartlett, Thomas

2002-01-01

Discusses how faculty members nationwide are reacting to a Web site that tracks professors' anti-Israel statements, and to a speech by Harvard's president, who linked an anti-Israel petition to anti-Semitism. (EV)

76 FR 44579 - Notice of Availability of Environmental Assessment for Strike Fighter Realignment at Naval Air...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-26

... Engineering Command, Southwest; Attn: Code EV21.AK; 1220 Pacific Highway, Building 1, 5th Floor; San Diego, CA... available for public review at the following Web site: http://www.cnic.navy.mil/cnrsw . In addition, paper... language informational materials will be made available on the Web site: http://www.cnic.navy.mil/cnrsw and...

Allosteric inhibitors of Coxsackie virus A24 RNA polymerase.

PubMed

Schein, Catherine H; Rowold, Diane; Choi, Kyung H

2016-02-15

Coxsackie virus A24 (CVA24), a causative agent of acute hemorrhagic conjunctivitis, is a prototype of enterovirus (EV) species C. The RNA polymerase (3D(pol)) of CVA24 can uridylylate the viral peptide linked to the genome (VPg) from distantly related EV and is thus, a good model for studying this reaction. Once UMP is bound, VPgpU primes RNA elongation. Structural and mutation data have identified a conserved binding surface for VPg on the RNA polymerase (3D(pol)), located about 20Å from the active site. Here, computational docking of over 60,000 small compounds was used to select those with the lowest (best) specific binding energies (BE) for this allosteric site. Compounds with varying structures and low BE were assayed for their effect on formation of VPgU by CVA24-3D(pol). Two compounds with the lowest specific BE for the site inhibited both uridylylation and formation of VPgpolyU at 10-20μM. These small molecules can be used to probe the role of this allosteric site in polymerase function, and may be the basis for novel antiviral compounds. Copyright © 2015 Elsevier Ltd. All rights reserved.

Thermal photovoltaic cells

NASA Astrophysics Data System (ADS)

Sharps, P. R.; Timmons, M. L.; Venkatasubramanian, R.; Hills, J. S.; O'Quinn, B.; Hutchby, J. A.; Iles, P. A.; Chu, C. L.

1995-01-01

Most current emphasis is on GaInAs alloys or GaSb for thermal photovoltaic converters operating in a band gap range between about 0.50 to 0.75 eV. In this paper the growth and fabrication of GaInAs devices with nominal band gaps of 0.6 eV are described. Yield statistics are presented for the growth of a large number of devices, and I-V data are presented. Alternative cell structures are also described, and manufacturing issues are discussed.

Non-native Co-, Mn-, and Ti-oxyhydroxide nanocrystals in ferritin for high efficiency solar energy conversion

NASA Astrophysics Data System (ADS)

Erickson, S. D.; Smith, T. J.; Moses, L. M.; Watt, R. K.; Colton, J. S.

2015-01-01

Quantum dot solar cells seek to surpass the solar energy conversion efficiencies achieved by bulk semiconductors. This new field requires a broad selection of materials to achieve its full potential. The 12 nm spherical protein ferritin can be used as a template for uniform and controlled nanocrystal growth, and to then house the nanocrystals for use in solar energy conversion. In this study, precise band gaps of titanium, cobalt, and manganese oxyhydroxide nanocrystals within ferritin were measured, and a change in band gap due to quantum confinement effects was observed. The range of band gaps obtainable from these three types of nanocrystals is 2.19-2.29 eV, 1.93-2.15 eV, and 1.60-1.65 eV respectively. From these measured band gaps, theoretical efficiency limits for a multi-junction solar cell using these ferritin-enclosed nanocrystals are calculated and found to be 38.0% for unconcentrated sunlight and 44.9% for maximally concentrated sunlight. If a ferritin-based nanocrystal with a band gap similar to silicon can be found (i.e. 1.12 eV), the theoretical efficiency limits are raised to 51.3% and 63.1%, respectively. For a current matched cell, these latter efficiencies become 41.6% (with an operating voltage of 5.49 V), and 50.0% (with an operating voltage of 6.59 V), for unconcentrated and maximally concentrated sunlight respectively.

Spatial Mapping of NEO 2008 EV5 Using Small Satellite Formation Flying and Steresoscopic Technology

NASA Astrophysics Data System (ADS)

Gonzalez, Juan; Singh Derewa, Chrishma

2016-10-01

NASA is currently developing the first-ever robotic Asteroid Redirect Robotic Mission (ARRM) to the near-Earth asteroid 2008 EV5 with the objective to capture a multi-ton boulder from the asteroids surface and use its mass to redirect its parent into a CIS lunar orbit where astronauts will study its physical and chemical composition.A critical step towards achieving this mission is to effectively map the target asteroid, identify the candidate boulder for retrieval and characterize its critical parameters. Currently, ARRM utilizes a laser altimeter to characterize the height of the boulders and mapping for final autonomous control of the capture. The proposed Lava-Kusha mission provides the increased of stereoscopic imaging and mapping, not only the Earthward side of the asteroid which has been observed for possible landing sites, but mapping the whole asteroid. LKM will enhance the fidelity of the data collected by the laser altimeter and gather improved topographic data for future Orion missions to 2008 EV5 once in cis lunar space.LKM consists of two low cost small satellites (6U) as a part of the ARRM. They will launch with ARRM as an integrated part of the system. Once at the target, this formation of pathfinder satellites will image the mission critical boulder to ensure the system design can support its removal. LKM will conduct a series of flybys prior to ARRM's rendezvous. LKMs stereoscopic cameras will provide detailed surveys of the boulder's terrain and environment to ensure ARRM can operate safely, reach the location and interface with the boulder. The LKM attitude control and cold gas propulsion system will enable formation maintenance maneuvers for global mapping of asteroid 2008 EV5 at an altitude of 100 km to a high-spatial resolution imaging altitude of 5 km.LKM will demonstrate formation flying in deep space and the reliability of stereoscopic cameras to precisely identify a specific target and provide physical characterization of an asteroid. An assessment of the off-the-shelf technology used at JPL will be provided also with technology readiness descriptions, mission architecture, cost analysis and future work required to make the proposed LKM mission a partner to ARRM.

Thermal battery for portable climate control

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

Narayanan, S; Li, XS; Yang, S

2015-07-01

Current technologies that provide climate control in the transportation sector are quite inefficient. In gasoline-powered vehicles, the use of air-conditioning is known to result in higher emissions of greenhouse gases and pollutants apart from decreasing the gas-mileage. On the other hand, for electric vehicles (EVs), a drain in the onboard electric battery due to the operation of heating and cooling system results in a substantial decrease in the driving range. As an alternative to the conventional climate control system, we are developing an adsorption-based thermal battery (ATB), which is capable of storing thermal energy, and delivering both heating and coolingmore » on demand, while requiring minimal electric power supply. Analogous to an electrical battery, the ATB can be charged for reuse. Furthermore, it promises to be compact, lightweight, and deliver high performance, which is desirable for mobile applications. In this study, we describe the design and operation of the ATB-based climate control system. We present a general theoretical framework to determine the maximum achievable heating and cooling performance using the ATB. The framework is then applied to study the feasibility of ATB integration in EVs, wherein we analyze the use of NaX zeolite-water as the adsorbent-refrigerant pair. In order to deliver the necessary heating and cooling performance, exceeding 2.5 kW h thermal capacity for EVs, the analysis determines the optimal design and operating conditions. While the use of the ATB in EVs can potentially enhance its driving range, it can also be used for climate control in conventional gasoline vehicles, as well as residential and commercial buildings as a more efficient and environmentally-friendly alternative. (C) 2015 Elsevier Ltd. All rights reserved.« less

Electronic and optical properties of Cu2XSnS4 (X = Be, Mg, Ca, Mn, Fe, and Ni) and the impact of native defect pairs

NASA Astrophysics Data System (ADS)

Chen, Rongzhen; Persson, Clas

2017-05-01

Reducing or controlling cation disorder in Cu2ZnSnS4 is a major challenge, mainly due to low formation energies of the anti-site pair ( CuZn - + ZnCu +) and the compensated Cu vacancy ( VCu - + ZnCu +). We study the electronic and optical properties of Cu2XSnS4 (CXTS, with X = Be, Mg, Ca, Mn, Fe, and Ni) and the impact of defect pairs, by employing the first-principles method within the density functional theory. The calculations indicate that these compounds can be grown in either the kesterite or stannite tetragonal phase, except Cu2CaSnS4 which seems to be unstable also in its trigonal phase. In the tetragonal phase, all six compounds have rather similar electronic band structures, suitable band-gap energies Eg for photovoltaic applications, as well as good absorption coefficients α(ω). However, the formation of the defect pairs ( C u X + X Cu) and ( V Cu + X Cu) is an issue for these compounds, especially considering the anti-site pair which has formation energy in the order of ˜0.3 eV. The ( C u X + X Cu) pair narrows the energy gap by typically ΔEg ≈ 0.1-0.3 eV, but for Cu2NiSnS4, the complex yields localized in-gap states. Due to the low formation energy of ( C u X + X Cu), we conclude that it is difficult to avoid disordering from the high concentration of anti-site pairs. The defect concentration in Cu2BeSnS4 is however expected to be significantly lower (as much as ˜104 times at typical device operating temperature) compared to the other compounds, which is partly explained by larger relaxation effects in Cu2BeSnS4 as the two anti-site atoms have different sizes. The disadvantage is that the stronger relaxation has a stronger impact on the band-gap narrowing. Therefore, instead of trying to reduce the anti-site pairs, we suggest that one shall try to compensate ( C u X + X Cu) with ( V Cu + X Cu) or other defects in order to stabilize the gap energy.

Design and testing of a dual-band enhanced vision system

NASA Astrophysics Data System (ADS)

Way, Scott P.; Kerr, Richard; Imamura, Joseph J.; Arnoldy, Dan; Zeylmaker, Dick; Zuro, Greg

2003-09-01

An effective enhanced vision system must operate over a broad spectral range in order to offer a pilot an optimized scene that includes runway background as well as airport lighting and aircraft operations. The large dynamic range of intensities of these images is best handled with separate imaging sensors. The EVS 2000 is a patented dual-band Infrared Enhanced Vision System (EVS) utilizing image fusion concepts. It has the ability to provide a single image from uncooled infrared imagers combined with SWIR, NIR or LLLTV sensors. The system is designed to provide commercial and corporate airline pilots with improved situational awareness at night and in degraded weather conditions but can also be used in a variety of applications where the fusion of dual band or multiband imagery is required. A prototype of this system was recently fabricated and flown on the Boeing Advanced Technology Demonstrator 737-900 aircraft. This paper will discuss the current EVS 2000 concept, show results taken from the Boeing Advanced Technology Demonstrator program, and discuss future plans for the fusion system.

Angular Resolution of an EAS Array for Gamma Ray Astronomy at Energies Greater Than 5 x 10 (13) Ev

NASA Technical Reports Server (NTRS)

Apte, A. R.; Gopalakrishnan, N. V.; Tonwar, S. C.; Uma, V.

1985-01-01

A 24 detector extensive air shower array is being operated at Ootacamund (2300 m altitude, 11.4 deg N latitude) in southern India for a study of arrival directions of showers of energies greater than 5 x 10 to the 13th power eV. Various configurations of the array of detectors have been used to estimate the accuracy in determination of arrival angle of showers with such an array. These studies show that it is possible to achieve an angular resolution of better than 2 deg with the Ooty array for search for point sources of Cosmic gamma rays at energies above 5 x 10 to the 13th power eV.

Optimization of the NIF ignition point design hohlraum

NASA Astrophysics Data System (ADS)

Callahan, D. A.; Hinkel, D. E.; Berger, R. L.; Divol, L.; Dixit, S. N.; Edwards, M. J.; Haan, S. W.; Jones, O. S.; Lindl, J. D.; Meezan, N. B.; Michel, P. A.; Pollaine, S. M.; Suter, L. J.; Town, R. P. J.; Bradley, P. A.

2008-05-01

In preparation for the start of NIF ignition experiments, we have designed a porfolio of targets that span the temperature range that is consistent with initial NIF operations: 300 eV, 285 eV, and 270 eV. Because these targets are quite complicated, we have developed a plan for choosing the optimum hohlraum for the first ignition attempt that is based on this portfolio of designs coupled with early NIF experiements using 96 beams. These early experiments will measure the laser plasma instabilities of the candidate designs and will demonstrate our ability to tune symmetry in these designs. These experimental results, coupled with the theory and simulations that went into the designs, will allow us to choose the optimal hohlraum for the first NIF ignition attempt.

Resonant charge transfer in He/+/-He collisions studied with the merging-beams technique

NASA Technical Reports Server (NTRS)

Rundel, R. D.; Nitz, D. E.; Smith, K. A.; Geis, M. W.; Stebbings, R. F.

1979-01-01

Absolute cross sections are reported for the resonant charge-transfer reaction He(+) + He yields He + He(+) at collision energies between 0.1 and 187 eV. The results, obtained using a new merging-beam apparatus are in agreement both with theory and with measurements made using other experimental techniques. The experimentally determined cross sections between 0.5 and 187 eV fall about a line given by sigma exp 1/2(sq-A) = 5.09-2.99 lnW, where W is the collision energy in eV. Considerable attention is paid to the configuration and operation of the apparatus. Tests and calculations which confirm the interpretation of the experimental data in a merging-beam experiment are discussed.

AVTA Federal Fleet PEV Readiness Data Logging and Characterization Study for the National Park Service: Fort Vancouver National Historic Site

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

Stephen Schey; Jim Francfort

Battelle Energy Alliance, LLC, managing and operating contractor for the U.S. Department of Energy’s Idaho National Laboratory, is the lead laboratory for the U.S. Department of Energy’s Advanced Vehicle Testing. Battelle Energy Alliance, LLC contracted with Intertek Testing Services, North America (ITSNA) to collect data on federal fleet operations as part of the Advanced Vehicle Testing Activity’s Federal Fleet Vehicle Data Logging and Characterization study. The Advanced Vehicle Testing Activity study seeks to collect data to validate the use of advanced electric drive vehicle transportation. This report focuses on the Fort Vancouver National Historic Site (FVNHS) fleet to identify dailymore » operational characteristics of select vehicles and report findings on vehicle and mission characterizations to support the successful introduction of electric vehicles (EVs) into the agencies’ fleet. Individual observations of the selected vehicles provided the basis for recommendations related to EV adoption and whether a battery electric vehicle (BEV) or plug-in hybrid electric vehicle (PHEV) (collectively plug-in electric vehicles) could fulfill the mission requirements. FVNHS identified three vehicles in its fleet for consideration. While the FVNHS vehicles conduct many different missions, only two (i.e., support and pool missions) were selected by agency management to be part of this fleet evaluation. The logged vehicles included a pickup truck and a minivan. This report will show that BEVs and PHEVs are capable of performing the required missions and providing an alternative vehicle for both mission categories, because each has sufficient range for individual trips and time available each day for charging to accommodate multiple trips per day. These charging events could occur at the vehicle’s home base, high-use work areas, or in intermediate areas along routes that the vehicles frequently travel. Replacement of vehicles in the current fleet would result in significant reductions in emission of greenhouse gases and petroleum use, while also reducing fuel costs. The Vancouver, Washington area and neighboring Portland, Oregon are leaders in adoption of PEVs in the United States1. PEV charging stations, or more appropriately identified as electric vehicle supply equipment, located on the FVNHS facility would be a benefit for both FVNHS fleets and general public use. Fleet drivers and park visitors operating privately owned plug-in electric vehicles benefit by using the charging infrastructure. ITSNA recommends location analysis of the FVNHS site to identify the optimal station placement for electric vehicle supply equipment. ITSNA recognizes the support of Idaho National Laboratory and ICF International for their efforts to initiate communication with the National Parks Service and FVNHS for participation in this study. ITSNA is pleased to provide this report and is encouraged by the high interest and support from the National Park Service and FVNHS personnel« less

The multi-targeted kinase inhibitor sorafenib inhibits enterovirus 71 replication by regulating IRES-dependent translation of viral proteins.

PubMed

Gao, Meng; Duan, Hao; Liu, Jing; Zhang, Hao; Wang, Xin; Zhu, Meng; Guo, Jitao; Zhao, Zhenlong; Meng, Lirong; Peng, Yihong

2014-06-01

The activation of ERK and p38 signal cascade in host cells has been demonstrated to be essential for picornavirus enterovirus 71 (EV71) replication and up-regulation of virus-induced cyclooxygenase-2 (COX-2)/prostaglandins E2 (PGE2) expression. The aim of this study was to examine the effects of sorafenib, a clinically approved anti-cancer multi-targeted kinase inhibitor, on the propagation and pathogenesis of EV71, with a view to its possible mechanism and potential use in the design of therapy regimes for Hand foot and mouth disease (HFMD) patients with life threatening neurological complications. In this study, non-toxic concentrations of sorafenib were shown to inhibit the yield of infectious progeny EV71 (clinical BC08 strain) by about 90% in three different cell types. A similar inhibitory effect of sorafenib was observed on the synthesis of both viral genomic RNA and the VP1 protein. Interestingly, sorafenib exerted obvious inhibition of the EV71 internal ribosomal entry site (IRES)-mediated translation, the first step in picornavirus replication, by linking it to a firefly luciferase reporter gene. Sorafenib was also able to prevent both EV71-induced CPE and the activation of ERK and p38, which contributes to up-regulation COX-2/PGE2 expression induced by the virus. Overall, this study shows that sorafenib strongly inhibits EV71 replication at least in part by regulating viral IRES-dependent translation of viral proteins, indicating a novel potential strategy for the treatment of HFMD patients with severe neurological complications. To our knowledge, this is the first report that investigates the mechanism by which sorafenib inhibits EV71 replication. Copyright © 2014 Elsevier B.V. All rights reserved.

Evolution and Emergence of Enteroviruses through Intra- and Inter-species Recombination: Plasticity and Phenotypic Impact of Modular Genetic Exchanges in the 5' Untranslated Region.

PubMed

Muslin, Claire; Joffret, Marie-Line; Pelletier, Isabelle; Blondel, Bruno; Delpeyroux, Francis

2015-01-01

Genetic recombination shapes the diversity of RNA viruses, including enteroviruses (EVs), which frequently have mosaic genomes. Pathogenic circulating vaccine-derived poliovirus (cVDPV) genomes consist of mutated vaccine poliovirus (PV) sequences encoding capsid proteins, and sequences encoding nonstructural proteins derived from other species' C EVs, including certain coxsackieviruses A (CV-A) in particular. Many cVDPV genomes also have an exogenous 5' untranslated region (5' UTR). This region is involved in virulence and includes the cloverleaf (CL) and the internal ribosomal entry site, which play major roles in replication and the initiation of translation, respectively. We investigated the plasticity of the PV genome in terms of recombination in the 5' UTR, by developing an experimental model involving the rescue of a bipartite PV/CV-A cVDPV genome rendered defective by mutations in the CL, following the co-transfection of cells with 5' UTR RNAs from each of the four human EV species (EV-A to -D). The defective cVDPV was rescued by recombination with 5' UTR sequences from the four EV species. Homologous and nonhomologous recombinants with large deletions or insertions in three hotspots were isolated, revealing a striking plasticity of the 5' UTR. By contrast to the recombination of the cVDPV with the 5' UTR of group II (EV-A and -B), which can decrease viral replication and virulence, recombination with the 5' UTRs of group I (EV-C and -D) appeared to be evolutionarily neutral or associated with a gain in fitness. This study illustrates how the genomes of positive-strand RNA viruses can evolve into mosaic recombinant genomes through intra- or inter-species modular genetic exchanges, favoring the emergence of new recombinant lineages.

Synthesis and electrical properties of BaBiO 3 and high resistivity BaTiO 3 –BaBiO 3 ceramics

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

Kumar, Nitish; Golledge, Stephen L.; Cann, David P.

2016-12-01

Ceramics of the composition BaBiO3 (BB) were sintered in oxygen to obtain a single phase with monoclinic II2/mm symmetry as suggested by high-resolution X-ray diffraction. X-ray photoelectron spectroscopy confirmed the presence of bismuth in two valence states - 3+ and 5+. Optical spectroscopy showed presence of a direct bandgap at ~ 2.2eV and a possible indirect bandgap at ~ 0.9eV. This combined with determination of the activation energy for conduction of 0.25eV, as obtained from ac impedance spectroscopy, suggested that a polaron-mediated conduction mechanism was prevalent in BB. The BB ceramics were crushed, mixed with BaTiO3 (BT), and sintered tomore » obtain BT–BB solid solutions. All the ceramics had tetragonal symmetry and exhibited a normal ferroelectric-like dielectric response. Using ac impedance and optical spectroscopy, it was shown that resistivity values of BT–BB were orders of magnitude higher than BT or BB alone, indicating a change in the fundamental defect equilibrium conditions. A shift in the site occupancy of Bi to the A-site is proposed to be the mechanism for the increased electrical resistivity.« less

Simplified Numerical Description of SPT Operations

NASA Technical Reports Server (NTRS)

Manzella, David H.

1995-01-01

A simplified numerical model of the plasma discharge within the SPT-100 stationary plasma thruster was developed to aid in understanding thruster operation. A one dimensional description was used. Non-axial velocities were neglected except for the azimuthal electron velocity. A nominal operating condition of 4.5 mg/s of xenon anode flow was considered with 4.5 Amperes of discharge current, and a peak radial magnetic field strength of 130 Gauss. For these conditions, the calculated results indicated ionization fractions of 0.99 near the thruster exit with a potential drop across the discharge of approximately 250 Volts. Peak calculated electron temperatures were found to be sensitive to the choice of total ionization cross section for ionization of atomic xenon by electron bombardment and ranged from 51 eV to 60 eV. The calculated ionization fraction, potential drop, and electron number density agree favorably with previous experiments. Calculated electron temperatures are higher than previously measured.

Straight and chopped dc performance data for a Prestolite MTC-4001 motor and a general electric EV-1 controller

NASA Technical Reports Server (NTRS)

Edie, P. C.

1981-01-01

Performance data on the Prestolite MTC-4001 series wound dc motor and General Electric EV-1 Chopper Controller is supplied for the electric vehicle manufacturer. Data are provided for both straight and chopped dc input to the motor, at 2 motor temperature levels. Testing was done at 6 voltage increments to the motor, and 2 voltage increments to the controller. Data results are presented in both tabular and graphical forms. Tabular information includes motor voltage and current input data, motor speed and torque output data, power data and temperature data. Graphical information includes torque-speed, motor power output-speed, torque-current, and efficiency-speed plots under the various operating conditions. The data resulting from this testing show the speed-torque plots to have the most variance with operating temperature. The maximum motor efficiency is between 76% and 82%, regardless of temperature or mode of operation.

Ectopic Enterobius Vermicularis Infestation; An Extremely Rare Cause Of Mesenteric Lymphadenopathy Mimicking Tuberculous Lymphadenitis.

PubMed

Zafar, Summaiya; Tariq, Muhammad Usman; Ahmed, Zubair

2018-01-01

Enterobius vermicularis (EV) is a pinworm which commonly resides in the lumen of the intestinal tract and lays eggs on the perianal skin. However, rarely the worm can infest various other sites in the body and cases with infestation of such ectopic sites have been reported in literature. Rare cases of mesenteric lymph node involvement have also been reported. We report a case in a young male who presented with signs and symptoms of acute appendicitis. During surgery, enlarged mesenteric lymph nodes were identified. Histological examination revealed adult worm in the appendiceal lumen. Histological examination of mesenteric lymph node revealed degenerated worm surrounded by caseating chronic granulomatous inflammation. We conclude that EV infestation should be considered in the differential diagnosis of enlarged mesenteric lymph node with chronic granulomatous inflammation, especially in young patients and when accompanying bowel tissue also reveal the helminth.

Potassium and water coadsorption on TiO 2(110): OH-induced anchoring of potassium and the generation of single-site catalysts

DOE PAGES

Grinter, David C.; R. Remesal, Elena; Luo, Si; ...

2016-09-15

Potassium deposition on TiO 2(110) results in reduction of the substrate and formation of loosely bound potassium species that can move easily on the oxide surface to promote catalytic activity. The results of density functional calculations predict a large adsorption energy (~3.2 eV) with a small barrier (~0.25 eV) for diffusion on the oxide surface. In scanning tunneling microscopy images, the adsorbed alkali atoms lose their mobility when in contact with surface OH groups. Furthermore, K adatoms facilitate the dissociation of water on the titania surface. Lastly, the K–(OH) species generated are good sites for the binding of gold clustersmore » on the TiO 2(110) surface, producing Au/K/TiO 2(110) systems with high activity for the water–gas shift.« less

First principles investigations of Fe2CrSi Heusler alloys by substitution of Co at Fe site

NASA Astrophysics Data System (ADS)

Jain, Rakesh; Lakshmi, N.; Jain, Vivek Kumar; Chandra, Aarti R.

2018-04-01

Electronic structure and magnetic properties of Fe2-xCoxCrSi Heusler alloys have been investigated by varying Co concentration from x = 0 to 2. On increasing Co concentration, lattice constant and magnetic moment of Fe2-xCoxCrSi alloys increase. These alloys show true half metallic Ferromagnetic behavior with 100% spin polarization. Band gap of the alloys also increase from 0.54 eV to 0.85 eV on increasing Co concentration making these alloys promising materials for spintronics based device applications.

Authentication System for Electrical Charging of Electrical Vehicles in the Housing Development

NASA Astrophysics Data System (ADS)

Song, Wang-Cheol

Recently the smart grid has been a hot issue in the research area. The Electric Vehicle (EV) is the most important component in the Smart Grid, having a role of the battery component with high capacity. We have thought how to introduce the EV in the housing development, and for proper operation of the smart grid systems in the housing area the authentication system is essential for the individual houses. We propose an authentication system to discriminate an individual houses, so that the account management component can appropriately operate the electrical charging and billing in the housing estate. The proposed system has an architecture to integrate the charging system outside a house and the monitoring system inside a house.

Progress toward a 30 percent-efficient, monolithic, three-junction, two-terminal concentrator solar cell for space applications

NASA Technical Reports Server (NTRS)

Partain, L. D.; Chung, B.-C.; Virshup, G. F.; Schultz, J. C.; Macmillan, H. F.; Ristow, M. Ladle; Kuryla, M. S.; Bertness, K. A.

1991-01-01

Component efficiencies of 0.2/sq cm cells at approximately 100x AMO light concentration and 80 C temperatures are not at 15.3 percent for a 1.9 eV AlGaAs top cell, 9.9 percent for a 1.4 eV GaAs middle cell under a 1.9 eV AlGaAs filter, and 2.4 percent for a bottom 1.0 eV InGaAs cell under a GaAs substrate. The goal is to continue improvement in these performance levels and to sequentially grow these devices on a single substrate to give 30 percent efficient, monolithic, two-terminal, three-junction space concentrator cells. The broad objective is a 30 percent efficient monolithic two-terminal cell that can operate under 25 to 100x AMO light concentrations and at 75 to 100 C cell temperatures. Detailed modeling predicts that this requires three junctions. Two options are being pursued, and both use a 1.9 eV AlGaAs top junction and a 1.4 eV GaAs middle junction grown by a 1 atm OMVPE on a lattice matched substrate. Option 1 uses a low-doped GaAs substrate with a lattice mismatched 1.0 eV InGaAs cell formed on the back of the substrate. Option 2 uses a Ge substrate to which the AlGaAs and GaAs top junctions are lattice matched, with a bottom 0.7 eV Ge junction formed near the substrate interface with the GaAs growth. The projected efficiency contributions are near 16, 11, and 3 percent, respectively, from the top, middle, and bottom junctions.

Evidence for Weakly Correlated Oxygen Holes in the Highest-Tc Cuprate Superconductor HgBa2 Ca2 Cu3 O8 +δ

NASA Astrophysics Data System (ADS)

Chainani, A.; Sicot, M.; Fagot-Revurat, Y.; Vasseur, G.; Granet, J.; Kierren, B.; Moreau, L.; Oura, M.; Yamamoto, A.; Tokura, Y.; Malterre, D.

2017-08-01

We study the electronic structure of HgBa2 Ca2 Cu3 O8 +δ (Hg1223; Tc=134 K ) using photoemission spectroscopy (PES) and x -ray absorption spectroscopy (XAS). Resonant valence band PES across the O K edge and Cu L edge identifies correlation satellites originating in O 2 p and Cu 3 d two-hole final states, respectively. Analyses using the experimental O 2 p and Cu 3 d partial density of states show quantitatively different on-site Coulomb energy for the Cu site (Ud d=6.5 ±0.5 eV ) and O site (Up p=1.0 ±0.5 eV ). Cu2 O7 -cluster calculations with nonlocal screening explain the Cu 2 p core level PES and Cu L -edge XAS spectra, confirm the Ud d and Up p values, and provide evidence for the Zhang-Rice singlet state in Hg1223. In contrast to other hole-doped cuprates and 3 d -transition metal oxides, the present results indicate weakly correlated oxygen holes in Hg1223.

Efficient evaluation of nonlocal operators in density functional theory

NASA Astrophysics Data System (ADS)

Chen, Ying-Chih; Chen, Jing-Zhe; Michaud-Rioux, Vincent; Shi, Qing; Guo, Hong

2018-02-01

We present a method which combines plane waves (PW) and numerical atomic orbitals (NAO) to efficiently evaluate nonlocal operators in density functional theory with periodic boundary conditions. Nonlocal operators are first expanded using PW and then transformed to NAO so that the problem of distance-truncation is avoided. The general formalism is implemented using the hybrid functional HSE06 where the nonlocal operator is the exact exchange. Comparison of electronic structures of a wide range of semiconductors to a pure PW scheme validates the accuracy of our method. Due to the locality of NAO, thus sparsity of matrix representations of the operators, the computational complexity of the method is asymptotically quadratic in the number of electrons. Finally, we apply the technique to investigate the electronic structure of the interface between a single-layer black phosphorous and the high-κ dielectric material c -HfO2 . We predict that the band offset between the two materials is 1.29 eV and 2.18 eV for valence and conduction band edges, respectively, and such offsets are suitable for 2D field-effect transistor applications.

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

Ghiringhelli, G.; Piazzalunga, A.; Dallera, C.

We present a 5 m long spectrometer for soft x rays to be used at a synchrotron radiation beamline for resonant x-ray emission spectroscopy and resonant inelastic x-ray scattering in the 400-1600 eV energy range. It is based on a variable line spacing spherical grating (average groove density of 3200 mm{sup -1}, R=58.55 m) and a charge coupled device two dimensional detector. With an x-ray spot on the sample of 10 {mu}m, the targeted resolving power is higher than 10 000 at all energies below 1100 eV and better than 7000 at 1500 eV. The off-line tests made with Almore » and Mg K{alpha}{sub 1,2} fluorescence emissions indicate that the spectrometer can actually work at 12 000 and 17 000 resolving power at the L{sub 3} edges of Cu (930 eV) and of Ti (470 eV), respectively. SAXES (superadvanced x-ray emission spectrometer) is mounted on a rotating platform allowing to vary the scattering angle from 25 degree sign to 130 degree sign . The spectrometer will be operational at the ADRESS (advanced resonant spectroscopies) beamline of the Swiss Light Source from 2007.« less

Studies of air showers produced by primaries 10(16) eV using a combined scintillation and water-Cerenkov array

NASA Technical Reports Server (NTRS)

Brooke, G.; Perrett, J. C.; Watson, A. A.

1986-01-01

An array of 8 x 1.0 sq m plastic scintillation counters and 13 water-Cerenkov detectors (1 to 13.5 sq m) were operated at the center of the Haverah Park array to study some features of air showers produced by 10(16) eV primaries. Measurements of the scintillator lateral distribution function, the water-Cerenkov lateral distribution function, and of the distance dependence of the Cerenkov/scintillator ratio are described.

PM2.5 source apportionment with organic markers in the Southeastern Aerosol Research and Characterization (SEARCH) study.

PubMed

Watson, John G; Chow, Judith C; Lowenthal, Douglas H; Antony Chen, L-W; Shaw, Stephanie; Edgerton, Eric S; Blanchard, Charles L

2015-09-01

Positive matrix factorization (PMF) and effective variance (EV) solutions to the chemical mass balance (CMB) were applied to PM(2.5) (particulate matter with an aerodynamic diameter <2.5 μm) mass and chemically speciated measurements for samples taken from 2008 to 2010 at the Atlanta, Georgia, and Birmingham, Alabama, sites. Commonly measured PM(2.5) mass, elemental, ionic, and thermal carbon fraction concentrations were supplemented with detailed nonpolar organic speciation by thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS). Source contribution estimates were calculated for motor vehicle exhaust, biomass burning, cooking, coal-fired power plants, road dust, vegetative detritus, and secondary sulfates and nitrates for Atlanta. Similar sources were found for Birmingham, with the addition of an industrial source and the separation of biomass burning into open burning and residential wood combustion. EV-CMB results based on conventional species were qualitatively similar to those estimated by PMF-CMB. Secondary ammonium sulfate was the largest contributor, accounting for 27-38% of PM(2.5), followed by biomass burning (21-24%) and motor vehicle exhaust (9-24%) at both sites, with 4-6% of PM(2.5) attributed to coal-fired power plants by EV-CMB. Including organic compounds in the EV-CMB reduced the motor vehicle exhaust and biomass burning contributions at both sites, with a 13-23% deficit for PM(2.5) mass. The PMF-CMB solution showed mixing of sources within the derived factors, both with and without the addition of speciated organics, as is often the case with complex source mixtures such as those at these urban-scale sites. The nonpolar TD-GC/MS compounds can be obtained from existing filter samples and are a useful complement to the elements, ions, and carbon fractions. However, they should be supplemented with other methods, such as TD-GC/MS on derivitized samples, to obtain a wider range of polar compounds such as sterols, sugars, and organic acids. The PMF and EV solutions to the CMB equations are complementary to, rather than replacements for, each other, as comparisons of their results reveal uncertainties that are not otherwise evident. Organic markers can be measured on currently acquired PM(2.5) filter samples by thermal methods. These markers can complement element, ion, and carbon fraction measurements from long-term speciation networks. Applying the positive matrix factorization and effective variance solutions for the chemical mass balance equations provides useful information on the accuracy of the source contribution estimates. Nonpolar compounds need to be complemented with polar compounds to better apportion cooking and secondary organic aerosol contributors.

TIA-1 and TIAR interact with 5'-UTR of enterovirus 71 genome and facilitate viral replication.

PubMed

Wang, Xiaohui; Wang, Huanru; Li, Yixuan; Jin, Yu; Chu, Ying; Su, Airong; Wu, Zhiwei

2015-10-16

Enterovirus 71 is one of the major causative pathogens of HFMD in children. Upon infection, the viral RNA is translated in an IRES-dependent manner and requires several host factors for effective replication. Here, we found that T-cell-restricted intracellular antigen 1 (TIA-1), and TIA-1 related protein (TIAR) were translocated from nucleus to cytoplasm after EV71 infection and localized to the sites of viral replication. We found that TIA-1 and TIAR can facilitate EV71 replication by enhancing the viral genome synthesis in host cells. We demonstrated that both proteins bound to the stem-loop I of 5'-UTR of viral genome and improved the stability of viral genomic RNA. Our results suggest that TIA-1 and TIAR are two new host factors that interact with 5-UTR of EV71 genome and positively regulate viral replication. Copyright © 2015 Elsevier Inc. All rights reserved.

High Chemical Activity of a Perovskite Surface: Reaction of CO with Sr3Ru2O7

NASA Astrophysics Data System (ADS)

Stöger, Bernhard; Hieckel, Marcel; Mittendorfer, Florian; Wang, Zhiming; Fobes, David; Peng, Jin; Mao, Zhiqiang; Schmid, Michael; Redinger, Josef; Diebold, Ulrike

2014-09-01

Adsorption of CO at the Sr3Ru2O7(001) surface was studied with low-temperature scanning tunneling microscopy (STM) and density functional theory. In situ cleaved single crystals terminate in an almost perfect SrO surface. At 78 K, CO first populates impurities and then adsorbs above the apical surface O with a binding energy Eads=-0.7 eV. Above 100 K, this physisorbed CO replaces the surface O, forming a bent CO2 with the C end bound to the Ru underneath. The resulting metal carboxylate (Ru-COO) can be desorbed by STM manipulation. A low activation (0.2 eV) and high binding (-2.2 eV) energy confirm a strong reaction between CO and regular surface sites of Sr3Ru2O7; likely, this reaction causes the "UHV aging effect" reported for this and other perovskite oxides.

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

Jimenez-Orozco, Carlos; Florez, Elizabeth; Moreno, Andres

A comprehensive study of acetylene adsorption on δ-MoC(001), TiC(001) and ZrC(001) surfaces was carried out by means of calculations based on periodic density functional theory, using the Perdew–Burke–Ernzerhof exchange–correlation functional. It was found that the bonding of acetylene was significantly affected by the electronic and structural properties of the carbide surfaces. The adsorbate interacted with metal and/or carbon sites of the carbide. The interaction of acetylene with the TiC(001) and ZrC(001) surfaces was strong (binding energies higher than $-$3.5 eV), while moderate acetylene adsorption energies were observed on δ-MoC(001) ($-$1.78 eV to –0.66 eV). Adsorption energies, charge density difference plotsmore » and Mulliken charges suggested that the binding of the hydrocarbon to the surface had both ionic and covalent contributions. According to the C–C bond lengths obtained, the adsorbed molecule was modified from acetylene-like into ethylene-like on the δ-MoC(001) surface (desired behavior for hydrogenation reactions) but into ethane-like on TiC(001) and ZrC(001). The obtained results suggest that the δ-MoC(001) surface is expected to have the best performance in selective hydrogenation reactions to convert alkynes into alkenes. Another advantage of δ-MoC(001) is that, after C 2H 2 adsorption, surface carbon sites remain available, which are necessary for H 2 dissociation. Furthermore, these sites were occupied when C 2H 2 was adsorbed on TiC(001) and ZrC(001), limiting their application in the hydrogenation of alkynes.« less

Operator Workload: Comprehensive Review and Evaluation of Operator Workload Methodologies

DTIC Science & Technology

1989-06-01

chocking for system failures or emergency conditions. It seems fair to characterize the changes In operator functions as more mental or cognitive In nature ...that the operator, the system hardware, and the evMronment all interact in affecting performance and this Interaction can change the nature of the task...a) classifying the nature of the operator tasks and (b) classifying workload assessment techniques. Task taxonomies are useful because some workload

Pathway to 50% efficient inverted metamorphic concentrator solar cells

NASA Astrophysics Data System (ADS)

Geisz, John F.; Steiner, Myles A.; Jain, Nikhil; Schulte, Kevin L.; France, Ryan M.; McMahon, William E.; Perl, Emmett E.; Horowitz, Kelsey A. W.; Friedman, Daniel J.

2017-09-01

Series-connected five (5J) and six junction (6J) concentrator solar cell strategies have the realistic potential to exceed 50% efficiency to enable low-cost CPV systems. We propose three strategies for developing a practical 6J device. We have overcome many of the challenges required to build such concentrator solar cell devices: We have developed 2.1 eV AlGaInP, 1.7 eV AlGaAs, and 1.7 eV GaInAsP junctions with external radiative efficiency greater than 0.1%. We have developed a transparent tunnel junction that absorbs minimal light intended for the second junction yet resists degradation under thermal load. We have developed metamorphic grades from the GaAs to the InP lattice constant that are transparent to sub-GaAs bandgap light. We have grown and compared low bandgap junctions (0.7eV - 1.2 eV) using metamorphic GaInAs, metamorphic GaInAsP, and GaInAsP lattice-matched to InP. And finally, we have demonstrated excellent performance in a high voltage, low current 4 junction inverted metamorphic device using 2.1, 1.7, 1.4, and 1.1 eV junctions with over 8.7 mA/cm2 one-sun current density that operates up to 1000 suns without tunnel junction failure.

Pathway to 50% Efficient Inverted Metamorphic Concentrator Solar Cells

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

Geisz, John F; Steiner, Myles A; Jain, Nikhil

Series-connected five (5J) and six junction (6J) concentrator solar cell strategies have the realistic potential to exceed 50% efficiency to enable low-cost CPV systems. We propose three strategies for developing a practical 6J device. We have overcome many of the challenges required to build such concentrator solar cell devices: We have developed 2.1 eV AlGaInP, 1.7 eV AlGaAs, and 1.7 eV GaInAsP junctions with external radiative efficiency greater than 0.1%. We have developed a transparent tunnel junction that absorbs minimal light intended for the second junction yet resists degradation under thermal load. We have developed metamorphic grades from the GaAsmore » to the InP lattice constant that are transparent to sub-GaAs bandgap light. We have grown and compared low bandgap junctions (0.7eV - 1.2 eV) using metamorphic GaInAs, metamorphic GaInAsP, and GaInAsP lattice-matched to InP. And finally, we have demonstrated excellent performance in a high voltage, low current 4 junction inverted metamorphic device using 2.1, 1.7, 1.4, and 1.1 eV junctions with over 8.7 mA/cm2 one-sun current density that operates up to 1000 suns without tunnel junction failure.« less

Influence of organic ions on DNA damage induced by 1 eV to 60 keV electrons.

PubMed

Zheng, Yi; Sanche, Léon

2010-10-21

We report the results of a study on the influence of organic salts on the induction of single strand breaks (SSBs) and double strand breaks (DSBs) in DNA by electrons of 1 eV to 60 keV. Plasmid DNA films are prepared with two different concentrations of organic salts, by varying the amount of the TE buffer (Tris-HCl and EDTA) in the films with ratio of 1:1 and 6:1 Tris ions to DNA nucleotide. The films are bombarded with electrons of 1, 10, 100, and 60 000 eV under vacuum. The damage to the 3197 base-pair plasmid is analyzed ex vacuo by agarose gel electrophoresis. The highest yields are reached at 100 eV and the lowest ones at 60 keV. The ratios of SSB to DSB are surprisingly low at 10 eV (∼4.3) at both salt concentrations, and comparable to the ratios measured with 100 eV electrons. At all characteristic electron energies, the yields of SSB and DSB are found to be higher for the DNA having the lowest salt concentration. However, the organic salts are more efficient at protecting DNA against the damage induced by 1 and 10 eV electrons. DNA damage and protection by organic ions are discussed in terms of mechanisms operative at each electron energy. It is suggested that these ions create additional electric fields within the groove of DNA, which modify the resonance parameter of 1 and 10 eV electrons, namely, by reducing the electron capture cross-section of basic DNA units and the lifetime of corresponding transient anions. An interstrand electron transfer mechanism is proposed to explain the low ratios for the yields of SSB to those of DSB produced by 10 eV electrons.

Influence of organic ions on DNA damage induced by 1 eV to 60 keV electrons

PubMed Central

Zheng, Yi; Sanche, Léon

2011-01-01

We report the results of a study on the influence of organic salts on the induction of single strand breaks (SSBs) and double strand breaks (DSBs) in DNA by electrons of 1 eV to 60 keV. Plasmid DNA films are prepared with two different concentrations of organic salts, by varying the amount of the TE buffer (Tris-HCl and EDTA) in the films with ratio of 1:1 and 6:1 Tris ions to DNA nucleotide. The films are bombarded with electrons of 1, 10, 100, and 60 000 eV under vacuum. The damage to the 3197 base-pair plasmid is analyzed ex vacuo by agarose gel electrophoresis. The highest yields are reached at 100 eV and the lowest ones at 60 keV. The ratios of SSB to DSB are surprisingly low at 10 eV (~4.3) at both salt concentrations, and comparable to the ratios measured with 100 eV electrons. At all characteristic electron energies, the yields of SSB and DSB are found to be higher for the DNA having the lowest salt concentration. However, the organic salts are more efficient at protecting DNA against the damage induced by 1 and 10 eV electrons. DNA damage and protection by organic ions are discussed in terms of mechanisms operative at each electron energy. It is suggested that these ions create additional electric fields within the groove of DNA, which modify the resonance parameter of 1 and 10 eV electrons, namely, by reducing the electron capture cross-section of basic DNA units and the lifetime of corresponding transient anions. An interstrand electron transfer mechanism is proposed to explain the low ratios for the yields of SSB to those of DSB produced by 10 eV electrons. PMID:20969428

Fed Up with Delays, a President Pushes To Outsource Technology Operations.

ERIC Educational Resources Information Center

Olsen, Florence

2002-01-01

Discusses how officials at Salt Lake Community College decided the only way they could get the kind of technology service they needed was to hire a company to run the operation; the plan will not save money, but seeks better service and room for expansion. (EV)

Informatic system for a global tissue–fluid biorepository with a graph theory–oriented graphical user interface

PubMed Central

Butler, William E.; Atai, Nadia; Carter, Bob; Hochberg, Fred

2014-01-01

The Richard Floor Biorepository supports collaborative studies of extracellular vesicles (EVs) found in human fluids and tissue specimens. The current emphasis is on biomarkers for central nervous system neoplasms but its structure may serve as a template for collaborative EV translational studies in other fields. The informatic system provides specimen inventory tracking with bar codes assigned to specimens and containers and projects, is hosted on globalized cloud computing resources, and embeds a suite of shared documents, calendars, and video-conferencing features. Clinical data are recorded in relation to molecular EV attributes and may be tagged with terms drawn from a network of externally maintained ontologies thus offering expansion of the system as the field matures. We fashioned the graphical user interface (GUI) around a web-based data visualization package. This system is now in an early stage of deployment, mainly focused on specimen tracking and clinical, laboratory, and imaging data capture in support of studies to optimize detection and analysis of brain tumour–specific mutations. It currently includes 4,392 specimens drawn from 611 subjects, the majority with brain tumours. As EV science evolves, we plan biorepository changes which may reflect multi-institutional collaborations, proteomic interfaces, additional biofluids, changes in operating procedures and kits for specimen handling, novel procedures for detection of tumour-specific EVs, and for RNA extraction and changes in the taxonomy of EVs. We have used an ontology-driven data model and web-based architecture with a graph theory–driven GUI to accommodate and stimulate the semantic web of EV science. PMID:25317275

The microbiome of the lung and its extracellular vesicles in nonsmokers, healthy smokers and COPD patients

PubMed Central

Kim, Hyun Jung; Kim, You-Sun; Kim, Kang-Hyun; Choi, Jun-Pyo; Kim, Yoon-Keun; Yun, Sunmi; Sharma, Lokesh; Dela Cruz, Charles S; Lee, Jae Seung; Oh, Yeon-Mok; Lee, Sang-Do; Lee, Sei Won

2017-01-01

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease, and bacterial infection plays a role in its pathogenesis. Bacteria secrete nanometer-sized extracellular vesicles (EVs), which may induce more immune dysfunction and inflammation than the bacteria themselves. We hypothesized that the microbiome of lung EVs might have distinct characteristics depending on the presence of COPD and smoking status. We analyzed and compared the microbiomes of 13 nonsmokers with normal spirometry, 13 smokers with normal spirometry (healthy smokers) and 13 patients with COPD by using 16S ribosomal RNA gene sequencing of surgical lung tissue and lung EVs. Subjects were matched for age and sex in all groups and for smoking levels in the COPD and healthy smoker groups. Each group included 12 men and 1 woman with the same mean age of 65.5 years. In all groups, EVs consistently showed more operational taxonomic units (OTUs) than lung tissue. In the healthy smoker and COPD groups, EVs had a higher Shannon index and a lower Simpson index than lung tissue and this trend was more prominent in the COPD group. Principal component analysis (PCA) showed clusters based on sample type rather than participants' clinical characteristics. Stenotrophomonas, Propionibacterium and Alicyclobacillus were the most commonly found genera. Firmicutes were highly present in the EVs of the COPD group compared with other samples or groups. Our analysis of the lung microbiome revealed that the bacterial communities present in the EVs and in the COPD group possessed distinct characteristics with differences in the OTUs, diversity indexes and PCA clustering. PMID:28408748

Informatic system for a global tissue-fluid biorepository with a graph theory-oriented graphical user interface.

PubMed

Butler, William E; Atai, Nadia; Carter, Bob; Hochberg, Fred

2014-01-01

The Richard Floor Biorepository supports collaborative studies of extracellular vesicles (EVs) found in human fluids and tissue specimens. The current emphasis is on biomarkers for central nervous system neoplasms but its structure may serve as a template for collaborative EV translational studies in other fields. The informatic system provides specimen inventory tracking with bar codes assigned to specimens and containers and projects, is hosted on globalized cloud computing resources, and embeds a suite of shared documents, calendars, and video-conferencing features. Clinical data are recorded in relation to molecular EV attributes and may be tagged with terms drawn from a network of externally maintained ontologies thus offering expansion of the system as the field matures. We fashioned the graphical user interface (GUI) around a web-based data visualization package. This system is now in an early stage of deployment, mainly focused on specimen tracking and clinical, laboratory, and imaging data capture in support of studies to optimize detection and analysis of brain tumour-specific mutations. It currently includes 4,392 specimens drawn from 611 subjects, the majority with brain tumours. As EV science evolves, we plan biorepository changes which may reflect multi-institutional collaborations, proteomic interfaces, additional biofluids, changes in operating procedures and kits for specimen handling, novel procedures for detection of tumour-specific EVs, and for RNA extraction and changes in the taxonomy of EVs. We have used an ontology-driven data model and web-based architecture with a graph theory-driven GUI to accommodate and stimulate the semantic web of EV science.

First-principles calculation of adsorption of shale gas on CaCO3 (100) surfaces.

PubMed

Luo, Qiang; Pan, Yikun; Guo, Ping; Wang, Zhouhua; Wei, Na; Sun, Pengfei; Liu, Yuxiao

2017-06-16

To demonstrate the adsorption strength of shale gas to calcium carbonate in shale matrix, the adsorption of shale gas on CaCO3 (100) surfaces was studied using the first-principles method, which is based on the density functional theory (DFT). The structures and electronic properties of CH4, C2H6, CO2 and N2 molecules were calculated by the generalized gradient approximation (GGA), for a coverage of 1 monolayer (ML). Under the same conditions, the density of states (DOS) of CaCO3 (100) surfaces before and after the adsorption of shale gas molecules at high-symmetry adsorption sites were compared. The results showed that the adsorption energies of CH4, C2H6, CO2 and N2 on CaCO3 (100) surfaces were between 0.2683 eV and -0.7388 eV. When a CH4 molecule was adsorbed at a hollow site and its 2 hydrogen atoms were parallel to the long diagonal (H3) on the CaCO3 (100) surface, it had the most stable adsorption, and the adsorption energy was only -0.4160 eV. The change of adsorption energy of CH4 was no more than 0.0535 eV. Compared with the DOS distribution of CH4 before adsorption, it shifted to the left overall after adsorption. At the same time, the partial density of states (PDOS) curves of CaCO3 (100) surfaces before and after adsorption basically overlapped. This work showed that the adsorption effect of shale gas on calcium carbonate is very weak, and the adsorption is physisorption at the molecular level.

Effects of rainfalls variability and physical-chemical parameters on enteroviruses in sewage and lagoon in Yopougon, Côte d'Ivoire

NASA Astrophysics Data System (ADS)

Momou, Kouassi Julien; Akoua-Koffi, Chantal; Traoré, Karim Sory; Akré, Djako Sosthène; Dosso, Mireille

2017-07-01

The aim of this study was to assess the variability of the content of nutrients, oxidizable organic and particulate matters in raw sewage and the lagoon on the effect of rainfall. Then evaluate the impact of these changes in the concentration of enteroviruses (EVs) in waters. The sewage samples were collected at nine sampling points along the channel, which flows, into a tropical lagoon in Yopougon. Physical-chemical parameters (5-day Biochemical Oxygen Demand, Chemical Oxygen Demand, Suspended Particulate Matter, Total Phosphorus, Orthophosphate, Total Kjeldahl Nitrogen and Nitrate) as well as the concentration of EV in these waters were determined. The average numbers of EV isolated from the outlet of the channel were 9.06 × 104 PFU 100 ml-1. Consequently, EV was present in 55.55 and 33.33 % of the samples in the 2 brackish lagoon collection sites. The effect of rainfall on viral load at the both sewage and brackish lagoon environments is significant correlate (two-way ANOVA, P < 0.05). Furthermore, in lagoon environment, nutrients (Orthophosphate, Total Phosphorus), 5-day Biochemical Oxygen Demand, Chemical Oxygen Demand and Suspended Particulate Matter were significant correlated with EVs loads ( P < 0.05 by Pearson test). The overall results highlight the problem of sewage discharge into the lagoon and correlation between viral loads and water quality parameters in sewage and lagoon.

Enhanced genetic algorithm optimization model for a single reservoir operation based on hydropower generation: case study of Mosul reservoir, northern Iraq.

PubMed

Al-Aqeeli, Yousif H; Lee, T S; Abd Aziz, S

2016-01-01

Achievement of the optimal hydropower generation from operation of water reservoirs, is a complex problems. The purpose of this study was to formulate and improve an approach of a genetic algorithm optimization model (GAOM) in order to increase the maximization of annual hydropower generation for a single reservoir. For this purpose, two simulation algorithms were drafted and applied independently in that GAOM during 20 scenarios (years) for operation of Mosul reservoir, northern Iraq. The first algorithm was based on the traditional simulation of reservoir operation, whilst the second algorithm (Salg) enhanced the GAOM by changing the population values of GA through a new simulation process of reservoir operation. The performances of these two algorithms were evaluated through the comparison of their optimal values of annual hydropower generation during the 20 scenarios of operating. The GAOM achieved an increase in hydropower generation in 17 scenarios using these two algorithms, with the Salg being superior in all scenarios. All of these were done prior adding the evaporation (Ev) and precipitation (Pr) to the water balance equation. Next, the GAOM using the Salg was applied by taking into consideration the volumes of these two parameters. In this case, the optimal values obtained from the GAOM were compared, firstly with their counterpart that found using the same algorithm without taking into consideration of Ev and Pr, secondly with the observed values. The first comparison showed that the optimal values obtained in this case decreased in all scenarios, whilst maintaining the good results compared with the observed in the second comparison. The results proved the effectiveness of the Salg in increasing the hydropower generation through the enhanced approach of the GAOM. In addition, the results indicated to the importance of taking into account the Ev and Pr in the modelling of reservoirs operation.

Simulation Evaluation of Equivalent Vision Technologies for Aerospace Operations

NASA Technical Reports Server (NTRS)

Kramer, Lynda J.; Williams, Steven P.; Wilz, Susan J.; Arthur, Jarvis J.

2009-01-01

A fixed-based simulation experiment was conducted in NASA Langley Research Center s Integration Flight Deck simulator to investigate enabling technologies for equivalent visual operations (EVO) in the emerging Next Generation Air Transportation System operating environment. EVO implies the capability to achieve or even improve on the safety of current-day Visual Flight Rules (VFR) operations, maintain the operational tempos of VFR, and perhaps even retain VFR procedures - all independent of the actual weather and visibility conditions. Twenty-four air transport-rated pilots evaluated the use of Synthetic/Enhanced Vision Systems (S/EVS) and eXternal Vision Systems (XVS) technologies as enabling technologies for future all-weather operations. The experimental objectives were to determine the feasibility of XVS/SVS/EVS to provide for all weather (visibility) landing capability without the need (or ability) for a visual approach segment and to determine the interaction of XVS/EVS and peripheral vision cues for terminal area and surface operations. Another key element of the testing investigated the pilot's awareness and reaction to non-normal events (i.e., failure conditions) that were unexpectedly introduced into the experiment. These non-normal runs served as critical determinants in the underlying safety of all-weather operations. Experimental data from this test are cast into performance-based approach and landing standards which might establish a basis for future all-weather landing operations. Glideslope tracking performance appears to have improved with the elimination of the approach visual segment. This improvement can most likely be attributed to the fact that the pilots didn't have to simultaneously perform glideslope corrections and find required visual landing references in order to continue a landing. Lateral tracking performance was excellent regardless of the display concept being evaluated or whether or not there were peripheral cues in the side window. Although workload ratings were significantly less when peripheral cues were present compared to when there were none, these differences appear to be operationally inconsequential. Larger display concepts tested in this experiment showed significant situation awareness (SA) improvements and workload reductions compared to smaller display concepts. With a fixed display size, a color display was more influential in SA and workload ratings than a collimated display.

Outsourcing Student Housing.

ERIC Educational Resources Information Center

Cirino, Anna Marie

2003-01-01

Describes discussion at a recent program of the National Association of College and University Business Officers (NACUBO) regarding the trend toward privatized student housing; discussion highlighted market conditions, financing, and operations. (EV)

Dynamics of ions generated by 2.3 kJ UNU/ICTP plasma focus device

NASA Astrophysics Data System (ADS)

Tangitsomboon, P.; Ngamrungroj, D.; Chandrema, E.; Mongkolnavin, R.

2017-09-01

UNU/ICTP Plasma Focus Device has been used as an ions source in many applications. In this paper, the full dynamic range of argon ions produced by the Plasma Focus Device from its initial phase through to beyond the focussing phase of the plasma is shown experimentally. The average speed of the ions is determined by measuring time taken for ions to reach different positions using magnetic probes and ion probes. Also, by adapting a well-established computational model that represents the dynamics of plasma in such device, it is also possible to determine the speed of these ions up to the point where the movement of the plasma sheath under the Lorentz force is completed. However, it was found that the speed determined by the computational model is higher in comparison with the values obtained experimentally at all different operating pressures. The ions’ speed found for operating pressure of 0.5 mbar, 1.0 mbar, 1.5 mbar and 2.0 mbar were 5.16 ± 0.04 cm/μs, 4.24 ± 0.04 cm/μs, 3.81 ± 0.03cm/μs and 3.16 ± 0.04 cm/μs respectively. These correspond to the ion energy of 551.38 ± 8.55 eV, 372.29 ± 7.02 eV, 300.61 ± 4.73 eV and 206.79 ± 5.24 eV.

Advantages and scientific basis of breastfeeding

USDA-ARS?s Scientific Manuscript database

The evidence behind current recommendations for breastfeeding is presented as a series of powerpoint slides with detailed references. Web sites and resources for infant feeding recommendations from the American Academy of Pediatrics and other health care provider professional groups are detailed. Ev...

RAPID OPTICAL SCREEN TOOL (ROST™) - INNOVATIVE TECHNOLOGY EVALUATION REPORT

EPA Science Inventory

In August 1994, a demonstration of cone penetrometer-mounted sensor technologies took place to evaluate their effectiveness in sampling and analyzing the physical and chemical characteristics of subsurface soil at hazardous waste sites. The effectiveness of each technology was ev...

Enhancement of spin polarization induced by Coulomb on-site repulsion between localized pz electrons in graphene embedded with line defects.

PubMed

Ren, Ji-Chang; Wang, Zhigang; Zhang, Rui-Qin; Ding, Zejun; Van Hove, Michel A

2015-11-11

It is well known that the effect of Coulomb on-site repulsion can significantly alter the physical properties of the systems that contain localized d and/or f electrons. However, little attention has been paid to the Coulomb on-site repulsion between localized p electrons. In this study, we demonstrated that Coulomb on-site repulsion between localized pz electrons also plays an important role in graphene embedded with line defects. It is shown that the magnetism of the system largely depends on the choice of the effective Coulomb on-site parameter Ueff. Ueff at the edges of the defect enhances the exchange splitting, which increases the magnetic moment and stabilizes a ferromagnetic state of the system. In contrast, Ueff at the center of the defect weakens the spin polarization of the system. The behavior of the magnetism is explained with the Stoner criterion and the charge accumulation at the edges of the defect. Based on the linear response approach, we estimate reasonable values of Ueff to be 2.55 eV (2.3 eV) at the center (edges) of the defects. More importantly, using a DFT+U+J method, we find that exchange interactions between localized p electrons also play an important role in the spin polarization of the system. These results imply that Coulomb on-site repulsion is necessary to describe the strong interaction between localized pz electrons of carbon related materials.

Joint Services Electronics Program.

DTIC Science & Technology

1987-03-31

58 (no previous unit) Unit 18 Adaptive Algorithms for Identification. Filtering. Control. and S ignal P rocessin g...two new faculty. Professors Arun and Wah. Finally. a total of six new faculty in the areas of adaptive and nonlinear systems. communication systems. and...previously), we observed an additional higher binding energy site at 2.6 eV The Sb coverage in the E, site increased ,xith ion dose and a model was developed

Full-length and defective enterovirus G genomes with distinct torovirus protease insertions are highly prevalent on a Chinese pig farm.

PubMed

Wang, Yan; Zhang, Wen; Liu, Zhijian; Fu, Xingli; Yuan, Jiaqi; Zhao, Jieji; Lin, Yuan; Shen, Quan; Wang, Xiaochun; Deng, Xutao; Delwart, Eric; Shan, Tongling; Yang, Shixing

2018-05-21

Recombination occurs frequently between enteroviruses (EVs) which are classified within the same species of the Picornaviridae family. Here, using viral metagenomics, the genomes of two recombinant EV-Gs (strains EVG 01/NC_CHI/2014 and EVG 02/NC_CHI/2014) found in the feces of pigs from a swine farm in China are described. The two strains are characterized by distinct insertion of a papain-like protease gene from toroviruses classified within the Coronaviridae family. According to recent reports the site of the torovirus protease insertion was located at the 2C/3A junction region in EVG 02/NC_CHI/2014. For the other variant EVG 01/NC_CHI/2014, the inserted protease sequence replaced the entire viral capsid protein region up to the VP1/2A junction. These two EV-G strains were highly prevalent in the same pig farm with all animals shedding the full-length genome (EVG 02/NC_CHI/2014) while 65% also shed the capsid deletion mutant (EVG 01/NC_CHI/2014). A helper-defective virus relationship between the two co-circulating EV-G recombinants is hypothesized.

Water Utility.

ERIC Educational Resources Information Center

Steinbach, Paul

2002-01-01

Describes how sharing campus aquatic facilities can help colleges cover the significant costs of operation. Discusses the priority-setting and planning required to constantly circulate different user groups in and out of pools. (EV)

Influence of the growth method on degradation of InGaN laser diodes

NASA Astrophysics Data System (ADS)

Bojarska, Agata; Muzioł, Grzegorz; Skierbiszewski, Czesław; Grzanka, Ewa; Wiśniewski, Przemysław; Makarowa, Irina; Czernecki, Robert; Suski, Tadek; Perlin, Piotr

2017-09-01

We demonstrate the influence of the operation current density and temperature on the degradation rate of InGaN laser diodes grown via metalorganic vapor-phase epitaxy (MOVPE) and plasma-assisted molecular beam epitaxy (PAMBE). The degradation rate of the MOVPE devices shows an exponential dependence on the temperature, with an activation energy of 0.38-0.43 eV, and a linear dependence on the operating current density. In comparison, the MBE-grown lasers exhibit a higher activation energy, on the order of 1 eV, and typically a lower degradation rate, resulting in a service time exceeding 50,000 h. We suggest that this difference may be related to the lower concentration of H in the Mg-doped MBE-grown GaN.

A relativistic density functional study of the role of 5f electrons in atomic and molecular adsorptions on actinide surfaces

NASA Astrophysics Data System (ADS)

Huda, Muhammad Nurul

Atomic and molecular adsorptions of oxygen and hydrogen on actinide surfaces have been studied within the generalized gradient approximations to density functional theory (GGA-DFT). The primary goal of this work is to understand the details of the adsorption processes, such as chemisorption sites, energies, adsorption configurations and activation energies for dissociation of molecules; and the signature role of the plutonium 5f electrons. The localization of the 5f electrons remains one of central questions in actinides and one objective here is to understand the extent to which localizations plays a role in adsorption on actinide surfaces. We also investigated the magnetism of the plutonium surfaces, given the fact that magnetism in bulk plutonium is a highly controversial issue, and the surface magnetism of it is not a well explored territory. Both the non-spin-polarized and spin-polarized calculations have been performed to arrive at our conclusions. We have studied both the atomic and molecular hydrogen and oxygen adsorptions on plutonium (100) and (111) surfaces. We have also investigated the oxygen molecule adsorptions on uranium (100) surface. Comparing the adsorption on uranium and plutonium (100) surfaces, we have seen that O2 chemisorption energy for the most favorable adsorption site on uranium surface has higher chemisorption energy, 9.492 eV, than the corresponding plutonium site, 8.787 eV. Also degree of localization of 5f electrons is less for uranium surface. In almost all of the cases, the most favorable adsorption sites are found where the coordination numbers are higher. For example, we found center sites are the most favorable sites for atomic adsorptions. In general oxygen reacts more strongly with plutonium surface than hydrogen. We found that atomic oxygen adsorption energy on (100) surface is 3.613 eV more than that of the hydrogen adsorptions, considering only the most favorable site. This is also true for molecular adsorptions, as the oxygen molecules on both (100) and (111) plutonium surfaces dissociate almost spontaneously, whereas hydrogen needs some activation energy to dissociate. From spin-polarized calculations we found both (100) and (111) surfaces have the layer by layer alternating spin-magnetic behavior. In general adsorption of H2 and O2 do not change this behavior.

Towards Stochastic Optimization-Based Electric Vehicle Penetration in a Novel Archipelago Microgrid.

PubMed

Yang, Qingyu; An, Dou; Yu, Wei; Tan, Zhengan; Yang, Xinyu

2016-06-17

Due to the advantage of avoiding upstream disturbance and voltage fluctuation from a power transmission system, Islanded Micro-Grids (IMG) have attracted much attention. In this paper, we first propose a novel self-sufficient Cyber-Physical System (CPS) supported by Internet of Things (IoT) techniques, namely "archipelago micro-grid (MG)", which integrates the power grid and sensor networks to make the grid operation effective and is comprised of multiple MGs while disconnected with the utility grid. The Electric Vehicles (EVs) are used to replace a portion of Conventional Vehicles (CVs) to reduce CO 2 emission and operation cost. Nonetheless, the intermittent nature and uncertainty of Renewable Energy Sources (RESs) remain a challenging issue in managing energy resources in the system. To address these issues, we formalize the optimal EV penetration problem as a two-stage Stochastic Optimal Penetration (SOP) model, which aims to minimize the emission and operation cost in the system. Uncertainties coming from RESs (e.g., wind, solar, and load demand) are considered in the stochastic model and random parameters to represent those uncertainties are captured by the Monte Carlo-based method. To enable the reasonable deployment of EVs in each MGs, we develop two scheduling schemes, namely Unlimited Coordinated Scheme (UCS) and Limited Coordinated Scheme (LCS), respectively. An extensive simulation study based on a modified 9 bus system with three MGs has been carried out to show the effectiveness of our proposed schemes. The evaluation data indicates that our proposed strategy can reduce both the environmental pollution created by CO 2 emissions and operation costs in UCS and LCS.

Towards Stochastic Optimization-Based Electric Vehicle Penetration in a Novel Archipelago Microgrid

PubMed Central

Yang, Qingyu; An, Dou; Yu, Wei; Tan, Zhengan; Yang, Xinyu

2016-01-01

Due to the advantage of avoiding upstream disturbance and voltage fluctuation from a power transmission system, Islanded Micro-Grids (IMG) have attracted much attention. In this paper, we first propose a novel self-sufficient Cyber-Physical System (CPS) supported by Internet of Things (IoT) techniques, namely “archipelago micro-grid (MG)”, which integrates the power grid and sensor networks to make the grid operation effective and is comprised of multiple MGs while disconnected with the utility grid. The Electric Vehicles (EVs) are used to replace a portion of Conventional Vehicles (CVs) to reduce CO2 emission and operation cost. Nonetheless, the intermittent nature and uncertainty of Renewable Energy Sources (RESs) remain a challenging issue in managing energy resources in the system. To address these issues, we formalize the optimal EV penetration problem as a two-stage Stochastic Optimal Penetration (SOP) model, which aims to minimize the emission and operation cost in the system. Uncertainties coming from RESs (e.g., wind, solar, and load demand) are considered in the stochastic model and random parameters to represent those uncertainties are captured by the Monte Carlo-based method. To enable the reasonable deployment of EVs in each MGs, we develop two scheduling schemes, namely Unlimited Coordinated Scheme (UCS) and Limited Coordinated Scheme (LCS), respectively. An extensive simulation study based on a modified 9 bus system with three MGs has been carried out to show the effectiveness of our proposed schemes. The evaluation data indicates that our proposed strategy can reduce both the environmental pollution created by CO2 emissions and operation costs in UCS and LCS. PMID:27322281

Highly Sensitive Assay for Detection of Enterovirus in Clinical Specimens by Reverse Transcription-PCR with an Armored RNA Internal Control

PubMed Central

Beld, Marcel; Minnaar, René; Weel, Jan; Sol, Cees; Damen, Marjolein; van der Avoort, Harry; Wertheim-van Dillen, Pauline; Breda, Alex van; Boom, René

2004-01-01

The objective of the present study was the development of a diagnostic reverse transcription (RT)-PCR for the specific detection of enterovirus (EV) RNA in clinical specimens controlled by an internal control (IC) RNA. The IC RNA contains the same primer binding sites as EV RNA but has a different probe region. The IC RNA was packaged into an MS2 phage core particle (armored) and was added to the clinical sample to allow monitoring of both extraction efficiency and RT-PCR efficiency. Serial dilutions of the IC RNA were made, and the detection limit of the RT-PCR was tested in a background of EV RNA-negative cerebrospinal fluid. The sensitivity and specificity of the RT-PCR assay were tested by using all 64 known EV serotypes, several non-EV serotypes, and two Quality Control for Molecular Diagnostics (QCMD) Program EV proficiency panels from 2001 and 2002. In total, 322 clinical specimens were tested by RT-PCR, and to establish the clinical utility of the RT-PCR, a comparison of the results of viral culture and RT-PCR was done with 87 clinical specimens. The lower limit of sensitivity was reached at about 150 copies of IC RNA/ml. All 64 EV serotypes were positive, while all non-EV serotypes were negative. All culture-positive samples of the 2001 QCMD proficiency panel (according to the 50% tissue culture infective doses per milliliter) were positive by RT-PCR. Invalid results, i.e., negativity for both EV RNA and IC RNA, due to inhibition of RT-PCR were observed for 33.3% of the members of the 2002 QCMD proficiency panel and 3.1% of the clinical specimens. Inhibition of RT-PCR could be relieved by the addition of 400 ng of bovine α-casein per μl to both the RT reaction mixture and the PCR mixture. With this optimized protocol, the results for all samples of the 2002 QCMD proficiency panel and all clinical specimens except one fecal sample (0.3%) were valid. Evaluation of the clinical samples demonstrated that EV infection could be detected in 12 of 87 samples (13.8%) by RT-PCR, while viral culture was negative. Our data show that the RT-PCR with armored IC RNA offers a very reliable and rapid diagnostic tool for the detection of EV in clinical specimens and that the addition of bovine α-casein relieved inhibition of the RT-PCR for 99.7% of clinical specimens. PMID:15243060

A Symphony of Software.

ERIC Educational Resources Information Center

Currents, 2002

2002-01-01

Offers a descriptive table of databases that help higher education institutions orchestrate advancement operations. Information includes vendor, contact, software, price, database engine/server platform, recommended reporting tools, record capacity, and client type. (EV)

Chemical vapor deposition techniques and related methods for manufacturing microminiature thermionic converters

DOEpatents

King, Donald B.; Sadwick, Laurence P.; Wernsman, Bernard R.

2002-06-25

Methods of manufacturing microminiature thermionic converters (MTCs) having high energy-conversion efficiencies and variable operating temperatures using MEMS manufacturing techniques including chemical vapor deposition. The MTCs made using the methods of the invention incorporate cathode to anode spacing of about 1 micron or less and use cathode and anode materials having work functions ranging from about 1 eV to about 3 eV. The MTCs also exhibit maximum efficiencies of just under 30%, and thousands of the devices can be fabricated at modest costs.

Training Program for Operation of Emergency Vehicles. Instructor Lesson Plans.

ERIC Educational Resources Information Center

INNOVATRIX, Inc., Ingomar, PA.

Unit lesson plans for the three parts of the Emergency Vehicle (EV) Operator training program are provided. The units in parts 1 and 2 are designed for use in a classroom setting and contain the following components: description of the unit; trainees' knowledge objectives; instructor preparation activities; instructional content/presentation…

Transcutaneous immunization via rapidly dissolvable microneedles protects against hand-foot-and-mouth disease caused by enterovirus 71.

PubMed

Zhu, Zhuangzhi; Ye, Xiaohua; Ku, Zhiqiang; Liu, Qingwei; Shen, Chaoyun; Luo, Huafei; Luan, Hansen; Zhang, Chenghao; Tian, Shaoqiong; Lim, CheeYen; Huang, Zhong; Wang, Hao

2016-12-10

Recent large outbreaks of hand-foot-and-mouth disease (HFMD) have seriously affected the health of young children. Enterovirus 71 (EV71) is the main causative agent of HFMD. Herein, for the first time, rapidly dissolvable microneedles (MNs) loaded with EV71 virus-like particles (VLPs) were evaluated whether they could induce robust immune responses that confer protection against EV71 infection. The characteristics of prepared MNs including hygroscopy, mechanical strength, insertion capacity, dissolution profile, skin irritation and storage stability were comprehensively assessed. EV71 VLPs remained morphologically stable during fabrication. The MNs made of sodium hyaluronate maintained their insertion ability for at least 3h even at a high relative humidity of 75%. With the aid of spring-operated applicator, EV71 MNs (approximately 500μm length) could be readily penetrated into the mouse skin in vivo, and then rapidly dissolved to release encapsulated antigen within 2min. Additionally, MNs induced slight erythema that disappeared within a few hours. More importantly, mouse immunization and virus challenge studies demonstrated that MNs immunization induced high level of antibody responses conferring full protection against lethal EV71 virus challenge that were comparable to conventional intramuscular injection, but with only 1/10th of the delivered antigen (dose sparing). Consequently, our rapidly dissolving MNs may present as an effective and promising transcutaneous immunization device for HFMD prophylaxis among children. Copyright © 2016 Elsevier B.V. All rights reserved.

Technology Solutions for School Food Service.

ERIC Educational Resources Information Center

Begalle, Mary

2002-01-01

Considers ways to include schools' food service departments in technology planning. Discusses school food service software applications, considerations and challenges of automating food service operations, and business-to-business Internet solutions. (EV)

Machines that Manage.

ERIC Educational Resources Information Center

Kennedy, Mike

2003-01-01

Describes how facilities-management systems use technology to help schools and universities operate their buildings more efficiently, reduce energy consumption, manage inventory more accurately, keep track of supplies and maintenance schedules, and save money. (EV)

Acetylene adsorption on δ-MoC(001), TiC(001) and ZrC(001) surfaces: A comprehensive periodic DFT study

DOE PAGES

Jimenez-Orozco, Carlos; Florez, Elizabeth; Moreno, Andres; ...

2016-12-06

A comprehensive study of acetylene adsorption on δ-MoC(001), TiC(001) and ZrC(001) surfaces was carried out by means of calculations based on periodic density functional theory, using the Perdew–Burke–Ernzerhof exchange–correlation functional. It was found that the bonding of acetylene was significantly affected by the electronic and structural properties of the carbide surfaces. The adsorbate interacted with metal and/or carbon sites of the carbide. The interaction of acetylene with the TiC(001) and ZrC(001) surfaces was strong (binding energies higher than $-$3.5 eV), while moderate acetylene adsorption energies were observed on δ-MoC(001) ($-$1.78 eV to –0.66 eV). Adsorption energies, charge density difference plotsmore » and Mulliken charges suggested that the binding of the hydrocarbon to the surface had both ionic and covalent contributions. According to the C–C bond lengths obtained, the adsorbed molecule was modified from acetylene-like into ethylene-like on the δ-MoC(001) surface (desired behavior for hydrogenation reactions) but into ethane-like on TiC(001) and ZrC(001). The obtained results suggest that the δ-MoC(001) surface is expected to have the best performance in selective hydrogenation reactions to convert alkynes into alkenes. Another advantage of δ-MoC(001) is that, after C 2H 2 adsorption, surface carbon sites remain available, which are necessary for H 2 dissociation. Furthermore, these sites were occupied when C 2H 2 was adsorbed on TiC(001) and ZrC(001), limiting their application in the hydrogenation of alkynes.« less

The calculated magnetic, electronic and thermodynamic properties of Ce{sub 3}Co{sub 29}Si{sub 4}B{sub 10} compound

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

Huo, Jin-Rong; Wang, Xiao-Xu; Cloud Computing Department, Beijing Computing Center, Beijing 100084

2016-05-15

The magnetic moment, lattice parameter and atom fraction coordinates for Ce{sub 3}Co{sub 29}Si{sub 4}B{sub 10} are calculated by the first-principles GGA+U method, and the results indicate that the calculated and experimental values are basically accordant when U=2.6 eV. We study the interaction effect and orbital hybridization between Co and Ce atoms. The projected density of states at U=2.6 eV which provided by Co-2c, Ce-2b and Ce-4d sites are contrasted with else U values. Meanwhile the electron density of states for different sites and the distance between various atoms are exhibited. In addition, the thermodynamic properties of Ce{sub 3}Co{sub 29}Si{sub 4}B{submore » 10} are evaluated by using a series of interatomic pair potentials. - Graphical abstract: Change of the total magnetic moment for Ce{sub 3}Co{sub 29}Si{sub 4}B{sub 10} along with the value of U. There is a sharply decline of the curve at U=2.6 eV and, at the moment, the total magnetic moment of the compound have a good agreement with the experimental data. - Highlights: • We research of quaternary rare earth and transition metal compounds. • We perform the calculation of magnetic moment and electronic structure by GGA+U method. • The orbital hybridization between Co and Ce atoms is displayed and analyzed. • Show the plot of projected density of states for different sites more clearly. • Calculate the thermodynamic property of rare-earth transition metal compound.« less

Charge ordering in the metal-insulator transition of V-doped CrO2 in the rutile structure.

PubMed

Biswas, Sarajit

2018-04-17

Electronic, magnetic, and structural properties of pure and V-doped CrO 2 were extensively investigated utilizing density functional theory. Usually, pure CrO 2 is a half-metallic ferromagnet with conductive spin majority species and insulating spin minority species. This system remains in its half-metallic ferromagnetic phase even at 50% V-substitution for Cr within the crystal. The V-substituted compound Cr 0.5 V 0.5 O 2 encounters metal-insulator transition upon the application of on-site Coulomb repulsion U = 7 eV preserving its ferromagnetism in the insulating phase. It is revealed in this study that Cr 3+ -V 5+ charge ordering accompanied by the transfer of the single V-3d electron to the Cr-3dt 2g orbitals triggers metal-insulator transition in Cr 0.5 V 0.5 O 2 . The ferromagnetism of Cr 0.5 V 0.5 O 2 in the insulating phase arises predominantly due to strong Hund's coupling between the occupied electrons in the Cr-t 2g states. Besides this, the ferromagnetic Curie temperature (T c ) decreases significantly due to V-substitution. Interestingly, a structural distortion is observed due to tilting of CrO 6 or VO 6 octahedra across the metal-insulator transition of Cr 0.5 V 0.5 O 2 . Graphical abstract The V-doped compound Cr 0.5 V 0.5 O 2 is found a half-metallic ferromagnet (HMF) in the absence of on-site Coulomb interaction (U). This HMF behavor maintains up to U = 6 eV. Eventually, this system encounters metal-insulator transition (MIT) upon the application of U = 7 eV with a band gap of E g ~ 0.31 eV. Nevertheless, applications of higher U widen the band gaps. In this figure, calculated total (black), Cr-3d (red), V-3d (violet), and O-2p (blue) DOS of Cr 0.5 V 0.5 O 2 for U = 8 eV are illustrated. The system is insulating with a band gap of E g ~ 0.7 eV.

Determination of Gamma-Prime Site Occupancies in Nickel Superalloys Using Atom Probe Tomography and X-Ray Diffraction (Preprint)

DTIC Science & Technology

2012-08-01

unlimited that Ni and Al occupy different sites of the γ’ lattice and also in agreement with Equations ( 4 ) - ( 6 ). At E1 = 5989 eV, the structure factor...3. DATES COVERED (From - To) August 2012 Technical Paper 1 July 2012 – 1 August 2012 4 . TITLE AND SUBTITLE DETERMINATION OF γ’SITE OCCUPANCIES...PROGRAM ELEMENT NUMBER 62102F 6 . AUTHOR(S) J. Tiley, O. Senkov, and G. Viswanathan (AFRL/RXCM) S. Nag and R. Banerjee (University of North Texas

Thermodynamics and Cation Diffusion in the Oxygen Ion Conductor Lsgm

NASA Astrophysics Data System (ADS)

Martin, M.; Schulz, O.

Perovskite type oxides based on LaGaO3 are of large technical interest because of their high oxygen-ion conductivity. Lanthanum gallate doped with Sr on A- and Mg on B-sites, La1-xSrxGa1-yMgyO3-(x+y)/2 (LSGM), reaches higher oxygen-ion conductivities than yttria-doped zirconia (YSZ). Thus LSGM represents a promising alternative for YSZ as electrolyte in solid oxide fuel cells (SOFC). Cells using thin LSGM-layers as electrolyte are expected to operate at intermediate temperatures around 700°C for more than 30000 hours without severe degradation. A potential long term degradation effect of LSGM is kinetic demixing of the electrolyte, caused by different cation diffusion coefficients. In this paper we report on experimental studies concerning the phase diagram of LSGM and the diffusion of cations. Cation self-diffusion of 139La, 84Sr and 25Mg and cation impurity diffusion of 144Nd, 89Y and 56Fe in polycrystalline LSGM samples was investigated by secondary ion mass spectrometry (SIMS) for temperatures between 900°C and 1400°C. It was found that diffusion occurs by means of bulk and grain boundaries. The bulk diffusion coefficients are similar for all cations with activation energies which are strongly dependent on temperature. At high temperatures, the activation energies are about 5 eV, while at low temperatures values of about 2 eV are found. These results are explained by a frozen in defect structure at low temperatures. This means that the observed activation energy at low temperatures represents only the migration energy of the different cations while the observed activation energy at high temperatures is the sum of the defect formation energy and the migration energy. The migration energies for all cations are nearly identical, although 139La, 84Sr and 144Nd are occupying A-sites while 25Mg and 56Fe are occupying B-sites in the perovskite-structure. To explain these experimental findings we propose a defect cluster containing cation vacancies in both the A- and the B-sublattice and anion vacancies as well.

[Anesthetic Management Using Transesophageal Echocardiography and EV1000 in a Patient with Ebstein's Anomary Undergoing Scoliosis Surgery].

PubMed

Tanimura, Kazuki; Miura, Yukiko; Ishii, Hisanari

2016-02-01

An 18-year-old female patinet with Ebstein anomaly underwent surgical repair of scoliosis under total intravenous anesthesia. In addtition to normal monitors, we used transesophageal echocardiography (TEE) and EV1000 (Edwards Lifesciences, Irvine, USA), which show stroke volume variation and stroke volume index simultaneously in a rectangular coordinates. TEE detected reversal of intracardiac shunt which caused SpO2 decrease during fixing screws at thoracic vertebrae, then manual ventilation with oxygen unproved SpO2. Because of a high venous pressure due to Ebstein anomaly, surgical bleeding seemed to be larger than usual. By using EV1000, volume status and cardiac contractility were estimated and adequate volume loading and inoptrope injection were performed to stabilize circulatory condition. The operation was completed without any cardiac and respiratory complications.

Thermoelectric properties of 2H-CuGaO2 for device applications: A first principle TB-mBJ potential study

NASA Astrophysics Data System (ADS)

Bhamu, K. C.; Praveen, C. S.

2017-12-01

Here we report the structural, electronic, optical, and thermoelectric properties of delafossite type 2H-CuGaO2 using first principles calculations. The present calculation predict an indirect band gap of 1.20 eV and a direct band gap of 3.48 eV. A detailed analysis of the electronic structure is provided based on atom and orbital projected density of states. Frequency dependent dielectric functions, refractive index, and absorption coefficient as a function of photon energy are discussed. The thermoelectric properties with power factor, and the figure of merit are reported as a function of chemical potential in the region ± 0.195 (μ -EF) eV at constant temperature of 300 and 800 K. The thermoelectric properties shows that 2H-CuGaO2 could be potential candidate for engineering devises operating at high temperature for the chemical potential in the range of ± 0.055 (μ -EF) eV and beyond this range the thermoelectric performance of 2H-CuGaO2 get reduced.

Distribution path robust optimization of electric vehicle with multiple distribution centers

PubMed Central

Hao, Wei; He, Ruichun; Jia, Xiaoyan; Pan, Fuquan; Fan, Jing; Xiong, Ruiqi

2018-01-01

To identify electrical vehicle (EV) distribution paths with high robustness, insensitivity to uncertainty factors, and detailed road-by-road schemes, optimization of the distribution path problem of EV with multiple distribution centers and considering the charging facilities is necessary. With the minimum transport time as the goal, a robust optimization model of EV distribution path with adjustable robustness is established based on Bertsimas’ theory of robust discrete optimization. An enhanced three-segment genetic algorithm is also developed to solve the model, such that the optimal distribution scheme initially contains all road-by-road path data using the three-segment mixed coding and decoding method. During genetic manipulation, different interlacing and mutation operations are carried out on different chromosomes, while, during population evolution, the infeasible solution is naturally avoided. A part of the road network of Xifeng District in Qingyang City is taken as an example to test the model and the algorithm in this study, and the concrete transportation paths are utilized in the final distribution scheme. Therefore, more robust EV distribution paths with multiple distribution centers can be obtained using the robust optimization model. PMID:29518169

Sizing Dynamic Wireless Charging for Light-Duty Electric Vehicles in Roadway Applications

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

Foote, Andrew P; Ozpineci, Burak; Chinthavali, Madhu Sudhan

Dynamic wireless charging is a possible cure for the range limitations seen in electric vehicles (EVs) once implemented in highways or city streets. The contribution of this paper is the use of experimental data to show that the expected energy gain from a dynamic wireless power transfer (WPT) system is largely a function of average speed, which allows the power level and number of coils per mile of a dynamic WPT system to be sized for the sustained operation of an EV. First, data from dynamometer testing is used to determine the instantaneous energy requirements of a light-duty EV. Then,more » experimental data is applied to determine the theoretical energy gained by passing over a coil as a function of velocity and power level. Related simulations are performed to explore possible methods of placing WPT coils within roadways with comparisons to the constant velocity case. Analyses with these cases demonstrate what system ratings are needed to meet the energy requirements of the EV. The simulations are also used to determine onboard energy storage requirements for each driving cycle.« less

Active Oxygen Vacancy Site for Methanol Synthesis from CO2 Hydrogenation on In2O3(110): A DFT Study

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

Ye, Jingyun; Liu, Changjun; Mei, Donghai

2013-06-03

Methanol synthesis from CO2 hydrogenation on the defective In2O3(110) surface with surface oxygen vacancies has been investigated using periodic density functional theory calculations. The relative stabilities of six possible surface oxygen vacancies numbered from Ov1 to Ov6 on the perfect In2O3(110) surface were examined. The calculated oxygen vacancy formation energies show that the D1 surface with the Ov1 defective site is the most thermodynamically favorable while the D4 surface with the Ov4 defective site is the least stable. Two different methanol synthesis routes from CO2 hydrogenation over both D1 and D4 surfaces were studied and the D4 surface was foundmore » to be more favorable for CO2 activation and hydrogenation. On the D4 surface, one of the O atoms of the CO2 molecule fills in the Ov4 site upon adsorption. Hydrogenation of CO2 to HCOO on the D4 surface is both thermodynamically and kinetically favorable. Further hydrogenation of HCOO involves both forming the C-H bond and breaking the C-O bond, resulting in H2CO and hydroxyl. The HCOO hydrogenation is slightly endothermic with an activation barrier of 0.57 eV. A high barrier of 1.14 eV for the hydrogenation of H2CO to H3CO indicates that this step is the rate-limiting step in the methanol synthesis on the defective In2O3(110) surface. We gratefully acknowledge the supports from the National Natural Science Foundation of China (#20990223) and from US Department of Energy, Basic Energy Science program (DE-FG02-05ER46231). D. Mei was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. The computations were performed in part using the Molecular Science Computing Facility in the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL), which is a U.S. Department of Energy national scientific user facility located at Pacific Northwest National Laboratory in Richland, Washington. PNNL is a multiprogram national laboratory operated for DOE by Battelle.« less

A density functional theory study on the effect of zero-point energy corrections on the methanation profile on Fe(100).

PubMed

Govender, Ashriti; Ferré, Daniel Curulla; Niemantsverdriet, J W Hans

2012-04-23

The thermodynamics and kinetics of the surface hydrogenation of adsorbed atomic carbon to methane, following the reaction sequence C+4H(-->/<--)CH+3H(-->/<--)CH(2)+2H(-->/<--)CH(3)+H(-->/<--)CH(4), are studied on Fe(100) by means of density functional theory. An assessment is made on whether the adsorption energies and overall energy profile are affected when zero-point energy (ZPE) corrections are included. The C, CH and CH(2) species are most stable at the fourfold hollow site, while CH(3) prefers the twofold bridge site. Atomic hydrogen is adsorbed at both the twofold bridge and fourfold hollow sites. Methane is physisorbed on the surface and shows neither orientation nor site preference. It is easily desorbed to the gas phase once formed. The incorporation of ZPE corrections has a very slight, if any, effect on the adsorption energies and does not alter the trends with regards to the most stable adsorption sites. The successive addition of hydrogen to atomic carbon is endothermic up to the addition of the third hydrogen atom resulting in the methyl species, but exothermic in the final hydrogenation step, which leads to methane. The overall methanation reaction is endothermic when starting from atomic carbon and hydrogen on the surface. Zero-point energy corrections are rarely provided in the literature. Since they are derived from C-H bonds with characteristic vibrations on the order of 2500-3000 cm(-1), the equivalent ZPE of 1/2 hν is on the order of 0.2-0.3 eV and its effect on adsorption energy can in principle be significant. Particularly in reactions between CH(x) and H, the ZPE correction is expected to be significant, as additional C-H bonds are formed. In this instance, the methanation reaction energy of +0.77 eV increased to +1.45 eV with the inclusion of ZPE corrections, that is, less favourable. Therefore, it is crucial to include ZPE corrections when reporting reactions involving hydrogen-containing species. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characteristics of the NASA Lewis bumpy-torus plasma generated with positive applied potentials

NASA Technical Reports Server (NTRS)

Roth, J. R.; Gerdin, G. A.; Richardson, R. W.

1976-01-01

Experimental observations were made during steady-state operation of a bumpy-torus plasma at input powers up to 150 kW in deuterium and helium gas and with positive potentials applied to the midplane electrodes. In this steady-state ion heating method a modified Penning discharge is operated such that the plasma is acted upon by a combination of strong electric and magnetic fields. Experimental investigation of a deuterium plasma revealed electron temperatures from 14 to 140 eV and ion kinetic temperatures from 160 to 1785 eV. At least two distinct modes of operation exist. Experimental data shows that the average ion residence time in the plasma is virtually independent of the magnetic field strength. Data was taken when all 12 anode rings were at high voltage, and in other symmetric configurations in which the toroidal plasma was generated by applying positive potentials to six anode rings, three anode rings, and a single anode ring.

Analysis of electric and thermal behaviour of lithium-ion cells in realistic driving cycles

NASA Astrophysics Data System (ADS)

Tourani, Abbas; White, Peter; Ivey, Paul

2014-12-01

A substantial part of electric vehicles (EVs) powertrain is the battery cell. The cells are usually connected in series, and failure of a single cell can deactivate an entire module in the battery pack. Hence, understanding the cell behaviour helps to predict and improve the battery performance and leads to design a cost effective thermal management system for the battery pack. A first principle thermo electrochemical model is applied to study the cell behaviour. The model is in good agreement with the experimental results and can predict the heat generation and the temperature distribution across the cell for different operating conditions. The operating temperature effect on the cell performance is studied and the operating temperature for the best performance is verified. In addition, EV cells are examined in a realistic driving cycle from the Artemis class. The study findings lead to the proposal of some crucial recommendation to design cost effective thermal management systems for the battery pack.

Long-term operation of surface high-harmonic generation from relativistic oscillating mirrors using a spooling tape

DOE PAGES

Bierbach, Jana; Yeung, Mark; Eckner, Erich; ...

2015-05-01

Surface high-harmonic generation in the relativistic regime is demonstrated as a source of extreme ultra-violet (XUV) pulses with extended operation time. Relativistic high-harmonic generation is driven by a frequency-doubled high-power Ti:Sapphire laser focused to a peak intensity of 3·1019 W/cm2 onto spooling tapes. We demonstrate continuous operation over up to one hour runtime at a repetition rate of 1 Hz. Harmonic spectra ranging from 20 eV to 70 eV (62 nm to 18 nm) were consecutively recorded by an XUV spectrometer. An average XUV pulse energy in the µJ range is measured. With the presented setup, relativistic surface high-harmonic generationmore » becomes a powerful source of coherent XUV pulses that might enable applications in, e.g. attosecond laser physics and the seeding of free-electron lasers, when the laser issues causing 80-% pulse energy fluctuations are overcome.« less

Evolution and Emergence of Enteroviruses through Intra- and Inter-species Recombination: Plasticity and Phenotypic Impact of Modular Genetic Exchanges in the 5’ Untranslated Region

PubMed Central

Muslin, Claire; Joffret, Marie-Line; Pelletier, Isabelle; Blondel, Bruno; Delpeyroux, Francis

2015-01-01

Genetic recombination shapes the diversity of RNA viruses, including enteroviruses (EVs), which frequently have mosaic genomes. Pathogenic circulating vaccine-derived poliovirus (cVDPV) genomes consist of mutated vaccine poliovirus (PV) sequences encoding capsid proteins, and sequences encoding nonstructural proteins derived from other species’ C EVs, including certain coxsackieviruses A (CV-A) in particular. Many cVDPV genomes also have an exogenous 5’ untranslated region (5’ UTR). This region is involved in virulence and includes the cloverleaf (CL) and the internal ribosomal entry site, which play major roles in replication and the initiation of translation, respectively. We investigated the plasticity of the PV genome in terms of recombination in the 5’ UTR, by developing an experimental model involving the rescue of a bipartite PV/CV-A cVDPV genome rendered defective by mutations in the CL, following the co-transfection of cells with 5’ UTR RNAs from each of the four human EV species (EV-A to -D). The defective cVDPV was rescued by recombination with 5’ UTR sequences from the four EV species. Homologous and nonhomologous recombinants with large deletions or insertions in three hotspots were isolated, revealing a striking plasticity of the 5’ UTR. By contrast to the recombination of the cVDPV with the 5’ UTR of group II (EV-A and -B), which can decrease viral replication and virulence, recombination with the 5’ UTRs of group I (EV-C and -D) appeared to be evolutionarily neutral or associated with a gain in fitness. This study illustrates how the genomes of positive-strand RNA viruses can evolve into mosaic recombinant genomes through intra- or inter-species modular genetic exchanges, favoring the emergence of new recombinant lineages. PMID:26562151

Comprehensive analysis of statistical and model-based overlay lot disposition methods

NASA Astrophysics Data System (ADS)

Crow, David A.; Flugaur, Ken; Pellegrini, Joseph C.; Joubert, Etienne L.

2001-08-01

Overlay lot disposition algorithms in lithography occupy some of the highest leverage decision points in the microelectronic manufacturing process. In a typical large volume sub-0.18micrometers fab the lithography lot disposition decision is made about 500 times per day. Each decision will send a lot of wafers either to the next irreversible process step or back to rework in an attempt to improve unacceptable overlay performance. In the case of rework, the intention is that the reworked lot will represent better yield (and thus more value) than the original lot and that the enhanced lot value will exceed the cost of rework. Given that the estimated cost of reworking a critical-level lot is around 10,000 (based upon the opportunity cost of consuming time on a state-of-the-art DUV scanner), we are faced with the implication that the lithography lot disposition decision process impacts up to 5 million per day in decisions. That means that a 1% error rate in this decision process represents over 18 million per year lost in profit for a representative sit. Remarkably, despite this huge leverage, the lithography lot disposition decision algorithm usually receives minimal attention. In many cases, this lack of attention has resulted in the retention of sub-optimal algorithms from earlier process generations and a significant negative impact on the economic output of many high-volume manufacturing sites. An ideal lot- dispositioning algorithm would be an algorithm that results into the best economic decision being made every time - lots would only be reworked where the expected value (EV) of the reworked lot minus the expected value of the original lot exceeds the cost of the rework: EV(reworked lot)- EV(original lot)>COST(rework process) Calculating the above expected values in real-time has generally been deemed too complicated and maintenance-intensive to be practical for fab operations, so a simplified rule is typically used.

Surface-structure dependence of healing radiation-damage mechanism in nanoporous tungsten

NASA Astrophysics Data System (ADS)

Duan, Guohua; Li, Xiangyan; Sun, Jingjing; Hao, Congyu; Xu, Yichun; Zhang, Yange; Liu, Wei; Liu, C. S.

2018-01-01

Under nuclear fusion environments, displacement damage in tungsten (W) is usually caused by neutrons irradiation through producing large quantities of vacancies (Vs) and self-interstitial atoms (SIAs). These defects not only affect the mechanical properties of W, but also act as the trap sites for implanted hydrogen isotopes and helium. Nano-porous (NP) W with a high fraction of free surfaces has been developed to mitigate the radiation damage. However, the mechanism of the surface reducing defects accumulation is not well understood. By using multi-scale simulation methods, we investigated the interaction of the SIA and V with different surfaces on across length and time scales. We found that, at a typical operation temperature of 1000 K, surface (1 1 0) preferentially heals radiation damage of W compared with surface (1 0 0) and boundary (3 1 0). On surface (1 1 0), the diffusion barrier for the SIA is only 0.68 eV. The annihilation of the SIA-V happens via the coupled motion of the V segregation towards the surface from the bulk and the two-dimensional diffusion of the SIA on the surface. Such mechanism makes the surface (1 1 0) owe better healing capability. On surface (1 0 0), the diffusion energy barrier for the SIA is 2.48 eV, higher than the diffusion energy barrier of the V in bulk. The annihilation of the SIA-V occurs via the V segregation and recombination. The SIA was found to migrate one-dimensionally along a boundary (3 1 0) with a barrier of 0.21 eV, leading to a lower healing efficiency in the boundary. This study suggested that the on-surface process plays an important role in healing radiation damage of NP W in addition to surface-enhanced diffusion and annihilation near the surface. A certain surface structure renders nano-structured W more radiation-tolerant.

A density functional study on adsorption and dissociation of O 2 on Ir(1 0 0) surface

NASA Astrophysics Data System (ADS)

Erikat, I. A.; Hamad, B. A.; Khalifeh, J. M.

2011-06-01

The adsorption and the reaction barrier for the dissociation of O 2 on Ir(1 0 0) surface are studied using periodic self-consistent density functional theory (DFT) calculations. Dissociative adsorption is found to be energetically more favorable compared to molecular adsorption. Parallel approaches Prl1 and Prl2 on a hollow site with the same adsorption energy of -3.93 eV for both of them are found to have the most energetically preferred sites of adsorptions among all the studied cases. Hybridization between p-O 2 and d-metal orbitals is responsible for the dissociative adsorption. The minimum energy path is determined by using the nudge elastic band method (NEB). We found that the dissociation occurs immediately and very early in the dissociation path with a small activation barrier (0.26 eV), which means that molecular adsorption of O 2 on Ir(1 0 0) surface occurs at very low temperatures; this is consistent with previous experimental and theoretical studies on Ir surfaces.

Hole polarons and p -type doping in boron nitride polymorphs

NASA Astrophysics Data System (ADS)

Weston, L.; Wickramaratne, D.; Van de Walle, C. G.

2017-09-01

Boron nitride polymorphs hold great promise for integration into electronic and optoelectronic devices requiring ultrawide band gaps. We use first-principles calculations to examine the prospects for p -type doping of hexagonal (h -BN ), wurtzite (w z -BN ), and cubic (c -BN ) boron nitride. Group-IV elements (C, Si) substituting on the N site result in a deep acceptor, as the atomic levels of the impurity species lie above the BN valence-band maximum. On the other hand, group-II elements (Be, Mg) substituting on the B site do not give impurity states in the band gap; however, these dopants lead to the formation of small hole polarons. The tendency for polaron formation is far more pronounced in h -BN compared to w z -BN or c -BN . Despite forming small hole polarons, Be acceptors enable p -type doping, with ionization energies of 0.31 eV for w z -BN and 0.24 eV for c -BN ; these values are comparable to the Mg ionization energy in GaN.

Molecular dynamics and quasidynamics simulations of the annealing of bulk and near-surface interstitials formed in molecular-beam epitaxial Si due to low-energy particle bombardment during deposition

NASA Technical Reports Server (NTRS)

Kitabatake, M.; Fons, P.; Greene, J. E.

1991-01-01

The relaxation, diffusion, and annihilation of split and hexagonal interstitials resulting from 10 eV Si irradiation of (2x1)-terminated Si(100) are investigated. Molecular dynamics and quasidynamics simulations, utilizing the Tersoff many-body potential are used in the investigation. The interstitials are created in layers two through six, and stable atomic configurations and total potential energies are derived as a function of site symmetry and layer depth. The interstitial Si atoms are allowed to diffuse, and the total potential energy changes are calculated. Lattice configurations along each path, as well as the starting configurations, are relaxed, and minimum energy diffusion paths are derived. The results show that the minimum energy paths are toward the surface and generally involved tetrahedral sites. The calculated interstitial migration activation energies are always less than 1.4 eV and are much lower in the near-surface region than in the bulk.

Rotation and diffusion of naphthalene on Pt(111)

NASA Astrophysics Data System (ADS)

Kolsbjerg, E. L.; Goubert, G.; McBreen, P. H.; Hammer, B.

2018-03-01

The behavior of naphthalene on Pt(111) surfaces is studied by combining insight from scanning tunneling microscopy (STM) and van der Waals enabled density functional theory. Adsorption, diffusion, and rotation are investigated by a series of variable temperature STM experiments revealing naphthalene ability to rotate on-site with ease with a rotational barrier of 0.69 eV. Diffusion to neighbouring sites is found to be more difficult. The experimental results are in good agreement with the theoretical investigations which confirm that the barrier for diffusion is slightly higher than the one for rotation. The theoretical barriers for rotation and translation are found to be 0.75 and 0.78 eV, respectively. An automatic mapping of the possible diffusion pathways reveals very detailed diffusion paths with many small local minima that would have been practically impossible to find manually. This automated procedure provides detailed insight into the preferred diffusion pathways that are important for our understanding of molecule-substrate interactions.

Orientation-dependent surface core-level shifts and chemical shifts on clean and H 2S-covered GaAs

NASA Astrophysics Data System (ADS)

Ranke, W.; Finster, J.; Kuhr, H. J.

1987-08-01

Photoelectron spectra of the As 3d and Ga 3d core levels were studied in situ on a cylindrically shaped GaAs single crystal for the six inequivalent orientations (001), (113), (111), (110), (11¯1) and (11¯3). On the clean surface, prepared by molecular beam epitaxy (MBE), surface core levels are shifted by 0.25 to 0.55 eV towards smaller binding energy (BE) for As 3d and -0.25 to -0.35 eV towards higher BE for Ga, depending on orientation. Additional As causes As 3d contributions shifted between -0.45 and -0.7 eV towards higher BE. The position and intensity of them is influenced by H 2S adsorption. At 150 K, H 2S adsorbs preferentially on As sites. As chemical shifts appear at -0.6 to -0.9 eV towards higher BE. Simultaneously, As accumulation occurs on all orientations with the exception of (110). High temperature adsorption (550 K, 720 K) influences mainly the Ga 3d peaks. Two peaks shifted by about -0.45 and -0.8 eV towards higher Be were found which are attributed to Ga atoms with one or two sulfur ligands, respectively. At 720 K, also As depletion is observed. The compatibility of surface core-level positions and intensities with recent structural models for the (111) and (11¯1) surfaces is discussed.

Thermally robust Au99(SPh)42 nanoclusters for chemoselective hydrogenation of nitrobenzaldehyde derivatives in water.

PubMed

Li, Gao; Zeng, Chenjie; Jin, Rongchao

2014-03-05

We report the synthesis and catalytic application of thermally robust gold nanoclusters formulated as Au99(SPh)42. The formula was determined by electrospray ionization and matrix-assisted laser desorption ionization mass spectrometry in conjunction with thermogravimetric analysis. The optical spectrum of Au99(SPh)42 nanoclusters shows absorption peaks at ~920 nm (1.35 eV), 730 nm (1.70 eV), 600 nm (2.07 eV), 490 nm (2.53 eV), and 400 nm (3.1 eV) in contrast to conventional gold nanoparticles, which exhibit a plasmon resonance band at 520 nm (for spherical particles). The ceria-supported Au99(SPh)42 nanoclusters were utilized as a catalyst for chemoselective hydrogenation of nitrobenzaldehyde to nitrobenzyl alcohol in water using H2 gas as the hydrogen source. The selective hydrogenation of the aldehyde group catalyzed by nanoclusters is a surprise because conventional nanogold catalysts instead give rise to the product resulting from reduction of the nitro group. The Au99(SPh)42/CeO2 catalyst gives high catalytic activity for a range of nitrobenzaldehyde derivatives and also shows excellent recyclability due to its thermal robustness. We further tested the size-dependent catalytic performance of Au25(SPh)18 and Au36(SPh)24 nanoclusters, and on the basis of their crystal structures we propose a molecular adsorption site for nitrobenzaldehyde. The nanocluster material is expected to find wide application in catalytic reactions.

BepiColombo Serena/ELENA instrument:development and testing

NASA Astrophysics Data System (ADS)

Orsini, S.; De Angelis, E.; Selci, S.; Di Lellis, A. M.:; Leoni, R.; Rispoli, R.; Colasanti, L.; Vertolli, N.; Scheer, J.; Mura, A.; Milillo, A.; Wurz, P.; D'Alessandro, M.; Maschietti, D.; Mattioli, F.; Cibella, S.; Brienza, D.; lo Spazio, Compagnia Generale per

2012-04-01

ELENA is a TOF sensor, based on a novel concept ultra-sonic oscillating shutter (Start section) which is operated at frequencies up to 50 kHz; a MCP detector is used as a Stop section. It is aimed to detect neutral atoms in the range 10 eV - 5 keV, within 70° FOV, perpendicular to the S/C orbital plane. ELENA will monitor the emission of neutral atoms from the whole surface of Mercury thanks to the spacecraft motion. The major scientific objectives are the interaction between the environment and the planet, the global particle loss-rate and the remote sensing of the surface properties. In particular, surface release processes are investigated by identifying particles release from the surface, via solar wind-induced ion sputtering (<1eV - >100 eV) as well as Hydrogen back-scattered at hundreds eV. In particular, the capability to detect non-thermal low energy neutral species is crucial for the sensor ELENA (Emitted Low-Energy Neutral Atoms), part of the package SERENA (Search for Exospheric Refilling and Emitted Natural Abundances) on board the BepiColombo mission to Mercury to be launched in 2014. The instrument is now validated and tested to reach its performances: the up-graded shutter system (Start section) has been operated for the first time with neutral atom beam and tested at high frequency, the Stop section has been calibrated investigating the region of very low energy detection efficiency, the electronics boards and the entire acquisition chain has been appointed and tested with ion beam. The first results of all the ELENA capability will be presented.

Solving the O&M Equation.

ERIC Educational Resources Information Center

Flach, Robert; Dorgan, Chad B.

2003-01-01

Concerning the issue of molds and indoor air quality in school buildings, addresses the importance of planning and design for building operations and maintenance, the effects of indoor air quality, and ongoing documentation and training. (EV)

Sequence specificity for uridylylation of the viral peptide linked to the genome (VPg) of enteroviruses.

PubMed

Schein, Catherine H; Ye, Mengyi; Paul, Aniko V; Oberste, M Steven; Chapman, Nora; van der Heden van Noort, Gerbrand J; Filippov, Dmitri V; Choi, Kyung H

2015-10-01

Enteroviruses (EV) uridylylate a peptide, VPg, as the first step in their replication. VPgpUpU, found free in infected cells, serves as the primer for RNA elongation. The abilities of four polymerases (3D(pol)), from EV-species A-C, to uridylylate VPgs that varied by up to 60% of their residues were compared. Each 3D(pol) was able to uridylylate all five VPgs using polyA RNA as template, while showing specificity for its own genome encoded peptide. All 3D(pol) uridylylated a consensus VPg representing the physical chemical properties of 31 different VPgs. Thus the residues required for uridylylation and the enzymatic mechanism must be similar in diverse EV. As VPg-binding sites differ in co-crystal structures, the reaction is probably done by a second 3D(pol) molecule. The conservation of polymerase residues whose mutation reduces uridylylation but not RNA elongation is compared. Copyright © 2015 Elsevier Inc. All rights reserved.

Enterovirus 71 infection of human airway organoids reveals VP1-145 as a viral infectivity determinant.

PubMed

van der Sanden, Sabine M G; Sachs, Norman; Koekkoek, Sylvie M; Koen, Gerrit; Pajkrt, Dasja; Clevers, Hans; Wolthers, Katja C

2018-05-09

Human enteroviruses frequently cause severe diseases in children. Human enteroviruses are transmitted via the fecal-oral route and respiratory droplets, and primary replication occurs in the gastro-intestinal and respiratory tracts; however, how enteroviruses infect these sites is largely unknown. Human intestinal organoids have recently proven to be valuable tools for studying enterovirus-host interactions in the intestinal tract. In this study, we demonstrated the susceptibility of a newly developed human airway organoid model for enterovirus 71 (EV71) infection. We showed for the first time in a human physiological model that EV71 replication kinetics are strain-dependent. A glutamine at position 145 of the VP1 capsid protein was identified as a key determinant of infectivity, and residues VP1-98K and VP1-104D were identified as potential infectivity markers. The results from this study provide new insights into EV71 infectivity in the human airway epithelia and demonstrate the value of organoid technology for virus research.

DNA strand breaks and crosslinks induced by transient anions in the range 2-20 eV.

PubMed

Luo, Xinglan; Zheng, Yi; Sanche, Léon

2014-04-15

The energy dependence of the yields of single and double strand breaks (SSB and DSB) and crosslinks induced by electron impact on plasmid DNA films is measured in the 2-20 eV range. The yield functions exhibit two strong maxima, which are interpreted to result from the formation of core-excited resonances (i.e., transient anions) of the bases, and their decay into the autoionization channel, resulting in π → π * electronic transitions of the bases followed by electron transfer to the C-O σ * bond in the phosphate group. Occupancy of the σ * orbital ruptures the C-O bond of the backbone via dissociative electron attachment, producing a SSB. From a comparison of our results with those of other works, including theoretical calculations and electron-energy-loss spectra of the bases, the 4.6 eV peak in the SSB yield function is attributed to the resonance decay into the lowest electronically excited states of the bases; in particular, those resulting from the transitions 1 3 A'( π 2 → π 3 *) and 1 3 A″(n 2 → π 3 *) of thymine and 1 3 A'( π → π *) of cytosine. The strongest peak at 9.6 eV in the SSB yield function is also associated with electron captured by excited states of the bases, resulting mostly from a multitude of higher-energy π → π * transitions. The DSB yield function exhibits strong maxima at 6.1 and 9.6 eV. The peak at 9.6 eV is probably related to the same resonance manifold as that leading to SSB, but the other at 6.1 eV may be more restricted to decay into the electronic state 1 3 A' ( π → π *) of cytosine via autoionization. The yield function of crosslinks is dominated by a broad peak extending over the 3.6-11.6 eV range with a sharper one at 17.6 eV. The different line shape of the latter function, compared to that of SSB and DSB, appears to be due to the formation of reactive radical sites in the initial supercoiled configuration of the plasmid, which react with the circular form (i.e., DNA with a SSB) to produce a crosslink.

Power grid operation risk management: V2G deployment for sustainable development

NASA Astrophysics Data System (ADS)

Haddadian, Ghazale J.

The production, transmission, and delivery of cost--efficient energy to supply ever-increasing peak loads along with a quest for developing a low-carbon economy require significant evolutions in the power grid operations. Lower prices of vast natural gas resources in the United States, Fukushima nuclear disaster, higher and more intense energy consumptions in China and India, issues related to energy security, and recent Middle East conflicts, have urged decisions makers throughout the world to look into other means of generating electricity locally. As the world look to combat climate changes, a shift from carbon-based fuels to non-carbon based fuels is inevitable. However, the variability of distributed generation assets in the electricity grid has introduced major reliability challenges for power grid operators. While spearheading sustainable and reliable power grid operations, this dissertation develops a multi-stakeholder approach to power grid operation design; aiming to address economic, security, and environmental challenges of the constrained electricity generation. It investigates the role of Electric Vehicle (EV) fleets integration, as distributed and mobile storage assets to support high penetrations of renewable energy sources, in the power grid. The vehicle-to-grid (V2G) concept is considered to demonstrate the bidirectional role of EV fleets both as a provider and consumer of energy in securing a sustainable power grid operation. The proposed optimization modeling is the application of Mixed-Integer Linear Programing (MILP) to large-scale systems to solve the hourly security-constrained unit commitment (SCUC) -- an optimal scheduling concept in the economic operation of electric power systems. The Monte Carlo scenario-based approach is utilized to evaluate different scenarios concerning the uncertainties in the operation of power grid system. Further, in order to expedite the real-time solution of the proposed approach for large-scale power systems, it considers a two-stage model using the Benders Decomposition (BD). The numerical simulation demonstrate that the utilization of smart EV fleets in power grid systems would ensure a sustainable grid operation with lower carbon footprints, smoother integration of renewable sources, higher security, and lower power grid operation costs. The results, additionally, illustrate the effectiveness of the proposed MILP approach and its potentials as an optimization tool for sustainable operation of large scale electric power systems.

Surface reaction of silicon chlorides during atomic layer deposition of silicon nitride

NASA Astrophysics Data System (ADS)

Yusup, Luchana L.; Park, Jae-Min; Mayangsari, Tirta R.; Kwon, Young-Kyun; Lee, Won-Jun

2018-02-01

The reaction of precursor with surface active site is the critical step in atomic layer deposition (ALD) process. We performed the density functional theory calculation with DFT-D correction to study the surface reaction of different silicon chloride precursors during the first half cycle of ALD process. SiCl4, SiH2Cl2, Si2Cl6 and Si3Cl8 were considered as the silicon precursors, and an NH/SiNH2*-terminated silicon nitride surface was constructed to model the thermal ALD processes using NH3 as well as the PEALD processes using NH3 plasma. The total energies of the system were calculated for the geometry-optimized structures of physisorption, chemisorption, and transition state. The order of silicon precursors in energy barrier, from lowest to highest, is Si3Cl8 (0.92 eV), Si2Cl6 (3.22 eV), SiH2Cl2 (3.93 eV) and SiCl4 (4.49 eV). Silicon precursor with lower energy barrier in DFT calculation showed lower saturation dose in literature for both thermal and plasma-enhanced ALD of silicon nitride. Therefore, DFT calculation is a promising tool in predicting the reactivity of precursor during ALD process.

Photoinduced current transient spectroscopy of deep levels and transport mechanisms in iron-doped GaN thin films grown by low pressure-metalorganic vapor phase epitaxy

NASA Astrophysics Data System (ADS)

Muret, P.; Pernot, J.; Azize, M.; Bougrioua, Z.

2007-09-01

Electrical transport and deep levels are investigated in GaN:Fe layers epitaxially grown on sapphire by low pressure metalorganic vapor phase epitaxy. Photoinduced current transient spectroscopy and current detected deep level spectroscopy are performed between 200 and 650 K on three Fe-doped samples and an undoped sample. A detailed study of the detected deep levels assigns dominant centers to a deep donor 1.39 eV below the conduction band edge EC and to a deep acceptor 0.75 eV above the valence band edge EV at low electric field. A strong Poole-Frenkel effect is evidenced for the donor. Schottky diodes characteristics and transport properties in the bulk GaN:Fe layer containing a homogenous concentration of 1019 Fe/cm3 are typical of a compensated semiconductor. They both indicate that the bulk Fermi level is located typically 1.4 eV below EC, in agreement with the neutrality equation and dominance of the deep donor concentration. This set of results demonstrates unambiguously that electrical transport in GaN:Fe is governed by both types, either donor or acceptor, of the iron impurity, either substitutional in gallium sites or associated with other defects.

A Search for Ultra--High-Energy Gamma-Ray Emission from Five Supernova Remnants

NASA Astrophysics Data System (ADS)

Allen, G. E.; Berley, D.; Biller, S.; Burman, R. L.; Cavalli-Sforza, M.; Chang, C. Y.; Chen, M. L.; Chumney, P.; Coyne, D.; Dion, C. L.; Dorfan, D.; Ellsworth, R. W.; Goodman, J. A.; Haines, T. J.; Hoffman, C. M.; Kelley, L.; Klein, S.; Schmidt, D. M.; Schnee, R.; Shoup, A.; Sinnis, C.; Stark, M. J.; Williams, D. A.; Wu, J.-P.; Yang, T.; Yodh, G. B.

1995-07-01

The majority of the cosmic rays in our Galaxy with energies in the range of ~1010--1014 eV are thought to be accelerated in supernova remnants (SNRs). Measurements of SNR gamma-ray spectra in this energy region could support or contradict this concept. The Energetic Gamma-Ray Experiment Telescope (EGRET) collaboration has reported six sources of gamma rays above 108 eV whose coordinates are coincident with SNRs. Five of these sources are within the field of view of the CYGNUS extensive air shower detector. A search of the CYGNUS data set reveals no evidence of gamma-ray emission at energies ~1014 eV for these five SNRs. The flux upper limits from the CYGNUS data are compared to the lower energy fluxes measured with the EGRET detector using Drury, Aharonian, & Volk's recent model of gamma-ray production in the shocks of SNRs. The results suggest one or more of the following: (1) the gamma-ray spectra for these five SNRs soften by about 1014 eV, (2) the integral gamma-ray spectra of the SNRs are steeper than about E-1.3, or (3) most of the gamma rays detected with the EGRET instrument for each SNR are not produced in the SNR's shock but are produced at some other site (such as a pulsar).

Effect of nickel monolayer deposition on the structural and electronic properties of the low miller indices of (bcc) iron: A DFT study

NASA Astrophysics Data System (ADS)

Kwawu, Caroline R.; Tia, Richard; Adei, Evans; Dzade, Nelson Y.; Catlow, C. Richard A.; de Leeuw, Nora H.

2017-04-01

Metal clusters of both iron (Fe) and nickel (Ni) have been found in nature as active electro-catalytic sites, for example in the enzyme carbon mono-oxide dehydrogenase found in autotrophic organisms. Thus, surface modification of iron with nickel could improve the surface work function to enhance catalytic applications. The effects of surface modifications of iron by nickel on the structural and electronic properties have been studied using spin-polarised density functional theory calculations within the generalised gradient approximation. The thermodynamically preferred sites for Ni adsorption on the Fe (100), (110) and (111) surfaces have been studied at varying monolayer coverages (including 0.25 ML and 1 ML). The work function of the bare Fe surfaces is found to be of the order (100) ∼ (111) < (110) i.e. 3.80 eV ∼ 3.84 eV < 4.76 eV, which is consistent with earlier studies. The adsorption energies show that monolayer Ni deposition is thermodynamically favoured on the (100) and (111) surfaces, but not on the (110) surface. Expansion of the first interlayer spacing (d12) of all three Fe surfaces is observed upon Ni deposition with the extent of expansion decreasing in the order (111) > (110) > (100), i.e. 6.78% > 5.76% > 1.99%. The extent of relaxation is magnified on the stepped (111) surface (by 1.09% to 30.88%), where the Ni coordination number is highest at 7 compared to 5 on the (100) facet and 4 on the (110) facet. The Ni deposition changes the work functions of the various surfaces due to charge reordering illustrated by charge density plots, where the work function is reduced only on the (110) surface by 0.04 eV, 0.16 eV and 0.17 eV at 1 ML, 0.5 ML and 0.25 ML respectively, with a concomitant increase in the surface dipole (polarity). This result implies enhanced electron activity and electrochemical reactivity on the most stable and therefore frequently occurring Ni-doped (110) facet compared to the clean (110) facet, which has implications for the development of improved Fe electro-catalysts (for example for CO2 activation and reduction). These findings improve our understanding of the role of surface topology and stability on the extent of Ni interactions with Fe surfaces and the extent to which the Fe surface structures and properties are altered by the Ni deposition.

Study of Small-Scale Anisotropy of Ultra-High-Energy Cosmic Rays Observed in Stereo by the High Resolution Fly's Eye Detector

NASA Astrophysics Data System (ADS)

Abbasi, R. U.; Abu-Zayyad, T.; Amann, J. F.; Archbold, G.; Atkins, R.; Bellido, J. A.; Belov, K.; Belz, J. W.; BenZvi, S.; Bergman, D. R.; Boyer, J. H.; Burt, G. W.; Cao, Z.; Clay, R. W.; Connolly, B. M.; Dawson, B. R.; Deng, W.; Fedorova, Y.; Findlay, J.; Finley, C. B.; Hanlon, W. F.; Hoffman, C. M.; Holzscheiter, M. H.; Hughes, G. A.; Hüntemeyer, P.; Jui, C. C. H.; Kim, K.; Kirn, M. A.; Knapp, B. C.; Loh, E. C.; Maestas, M. M.; Manago, N.; Mannel, E. J.; Marek, L. J.; Martens, K.; Matthews, J. A. J.; Matthews, J. N.; O'Neill, A.; Painter, C. A.; Perera, L.; Reil, K.; Riehle, R.; Roberts, M. D.; Sasaki, M.; Schnetzer, S. R.; Seman, M.; Simpson, K. M.; Sinnis, G.; Smith, J. D.; Snow, R.; Sokolsky, P.; Song, C.; Springer, R. W.; Stokes, B. T.; Thomas, J. R.; Thomas, S. B.; Thomson, G. B.; Tupa, D.; Westerhoff, S.; Wiencke, L. R.; Zech, A.; HIRES Collaboration

2004-08-01

The High Resolution Fly's Eye (HiRes) experiment is an air fluorescence detector which, operating in stereo mode, has a typical angular resolution of 0.6d and is sensitive to cosmic rays with energies above 1018 eV. The HiRes cosmic-ray detector is thus an excellent instrument for the study of the arrival directions of ultra-high-energy cosmic rays. We present the results of a search for anisotropies in the distribution of arrival directions on small scales (<5°) and at the highest energies (>1019 eV). The search is based on data recorded between 1999 December and 2004 January, with a total of 271 events above 1019 eV. No small-scale anisotropy is found, and the strongest clustering found in the HiRes stereo data is consistent at the 52% level with the null hypothesis of isotropically distributed arrival directions.

Microminiature thermionic converters

DOEpatents

King, Donald B.; Sadwick, Laurence P.; Wernsman, Bernard R.

2001-09-25

Microminiature thermionic converts (MTCs) having high energy-conversion efficiencies and variable operating temperatures. Methods of manufacturing those converters using semiconductor integrated circuit fabrication and micromachine manufacturing techniques are also disclosed. The MTCs of the invention incorporate cathode to anode spacing of about 1 micron or less and use cathode and anode materials having work functions ranging from about 1 eV to about 3 eV. Existing prior art thermionic converter technology has energy conversion efficiencies ranging from 5-15%. The MTCs of the present invention have maximum efficiencies of just under 30%, and thousands of the devices can be fabricated at modest costs.

Laser-Induced Fluorescence Velocity Measurements of a Low Power Cylindrical Hall Thruster

DTIC Science & Technology

2009-08-25

Hall thruster . Xenon ion velocities for the thruster are derived from laser-induced fluorescence measurements of the 5d[4]7/2-6p[3]5/2 xenon ion excited state transition. Three operating conditions are considered with variations to the magnetic field strength and chamber background pressure in an effort to capture their effects on ion acceleration and centerline ion energy distributions. Under nominal conditions, xenon ions are accelerated to an energy of 25 eV within the thruster with an additional 188 eV gain in the thruster plume. At a position 40 mm into the plume,

Thermal detectors for high resolution spectroscopy

NASA Technical Reports Server (NTRS)

Mccammon, D.; Juda, M.; Zhang, J.; Kelley, R. L.; Moseley, S. H.; Szymkowiak, A. E.

1986-01-01

Cryogenic microcalorimeters can be made sensitive enough to measure the energy deposited by a single particle or X-ray photon with an accuracy of about one electron volt. It may also be possible to construct detectors of several-kilograms mass whose resolution is only a few times worse than this. Data from relatively crude test devices are in good agreement with thermal performance calculations, and a total system noise of 11 eV FWHM has been obtained for a silicon detector operating at 98 mK. Observations of 35 eV FWHM for 6-keV X-rays with a different device have been made.

Design and analysis of aluminum/air battery system for electric vehicles

NASA Astrophysics Data System (ADS)

Yang, Shaohua; Knickle, Harold

Aluminum (Al)/air batteries have the potential to be used to produce power to operate cars and other vehicles. These batteries might be important on a long-term interim basis as the world passes through the transition from gasoline cars to hydrogen fuel cell cars. The Al/air battery system can generate enough energy and power for driving ranges and acceleration similar to gasoline powered cars. From our design analysis, it can be seen that the cost of aluminum as an anode can be as low as US 1.1/kg as long as the reaction product is recycled. The total fuel efficiency during the cycle process in Al/air electric vehicles (EVs) can be 15% (present stage) or 20% (projected) comparable to that of internal combustion engine vehicles (ICEs) (13%). The design battery energy density is 1300 Wh/kg (present) or 2000 Wh/kg (projected). The cost of battery system chosen to evaluate is US 30/kW (present) or US$ 29/kW (projected). Al/air EVs life-cycle analysis was conducted and compared to lead/acid and nickel metal hydride (NiMH) EVs. Only the Al/air EVs can be projected to have a travel range comparable to ICEs. From this analysis, Al/air EVs are the most promising candidates compared to ICEs in terms of travel range, purchase price, fuel cost, and life-cycle cost.

Effect of film thickness on NO2 gas sensing properties of sprayed orthorhombic nanocrystalline V2O5 thin films

NASA Astrophysics Data System (ADS)

Mane, A. A.; Moholkar, A. V.

2017-09-01

The nanocrystalline V2O5 thin films with different thicknesses have been grown onto the glass substrates using chemical spray pyrolysis (CSP) deposition method. The XRD study shows that the films exhibit an orthorhombic crystal structure. The narrow scan X-ray photoelectron spectrum of V-2p core level doublet gives the binding energy difference of 7.3 eV, indicating that the V5+ oxidation state of vanadium. The FE-SEM micrographs show the formation of nanorods-like morphology. The AFM micrographs show the high surface area to volume ratio of nanocrystalline V2O5 thin films. The optical study gives the band gap energy values of 2.41 eV, 2.44 eV, 2.47 eV and 2.38 eV for V2O5 thin films deposited with the thicknesses of 423 nm, 559 nm, 694 nm and 730 nm, respectively. The V2O5 film of thickness 559 nm shows the NO2 gas response of 41% for 100 ppm concentration at operating temperature of 200 °C with response and recovery times of 20 s and 150 s, respectively. Further, it shows the rapid response and reproducibility towards 10 ppm NO2 gas concentration at 200 °C. Finally, NO2 gas sensing mechanism based on chemisorption process is discussed.

The Public Discourse of U.S. Graduate Employee Unions: Social Movement Identities, Ideologies, and Strategies.

ERIC Educational Resources Information Center

Rhoades, Gary; Rhoads, Robert A.

2003-01-01

Drew on extensive archives from 10 graduate employee unions' Web sites to examine their publicly presented identities (marginalized workers and future professionals), ideologies (traditional and professional unionism with little focus on social justice), and strategies (disruptive protest and professional politics locally). (EV)

Endo-Fullerene and Doped Diamond Nanocrystallite Based Models of Qubits for Solid-State Quantum Computers

NASA Technical Reports Server (NTRS)

Park, Seongjun; Srivastava, Deepak; Cho, Kyeongjae; Biegel, Bryan (Technical Monitor)

2001-01-01

Models of encapsulated 1/2 nuclear spin H-1 and P-31 atoms in fullerene and diamond nanocrystallite, respectively, are proposed and examined with ab-initio local density functional method for possible applications as single quantum bits (qubits) in solid-state quantum computers. A H-1 atom encapsulated in a fully deuterated fullerene, C(sub 20)D(sub 20), forms the first model system and ab-initio calculation shows that H-1 atom is stable in atomic state at the center of the fullerene with a barrier of about 1 eV to escape. A P-31 atom positioned at the center of a diamond nanocrystallite is the second model system, and 3 1P atom is found to be stable at the substitutional site relative to interstitial sites by 15 eV, Vacancy formation energy is 6 eV in diamond so that substitutional P-31 atom will be stable against diffusion during the formation mechanisms within the nanocrystallite. The coupling between the nuclear spin and weakly bound (valance) donor electron coupling in both systems is found to be suitable for single qubit applications, where as the spatial distributions of (valance) donor electron wave functions are found to be preferentially spread along certain lattice directions facilitating two or more qubit applications. The feasibility of the fabrication pathways for both model solid-state qubit systems within practical quantum computers is discussed with in the context of our proposed solid-state qubits.

H2S adsorption and dissociation on NH-decorated graphene: A first principles study

NASA Astrophysics Data System (ADS)

Faye, Omar; Eduok, Ubong; Szpunar, Jerzy; Samoura, Almoustapha; Beye, Aboubaker

2018-02-01

The removal of H2S gas poses an emerging environmental concern because of the lack of knowledge of an efficient adsorbent. A detailed theoretical study of H2S adsorption and dissociation on NH-doped graphene (GNH) has been carried out by means of density theory calculations. Our results reveal that the adsorption of H2S molecule on GNH composite is enhanced by the presence of active site such as the NH radicals. These NH radical sites formed NHsbnd H bonds and increase the charge transfer from H2S to GNH. The dissociation of the adsorbed H2S molecule leads the chemisorption of SH radical via H-transfer to GNH, while the formation of GNH2 at a weight percent of 3.76 wt% of NH radical is an endothermic process with an energy of 0.299 eV and 0.358 eV for ortho and para-position respectively. However, at 7.25 wt% NH radical, we observed a complete dissociation of H2S molecule with an energy released of 0.711 eV for the chemisorbed S atom on GN2H4. Moreover, the H-transfer of the second H atom of H2S molecule at 3.76 wt% was energetic unfavorable. The trend of predicted results within this study reveals that NH-doped graphene (GNH) successfully adsorbed and eliminated of H2S molecule; this work unveils definitive theoretical procedures which can be tested and validated experimentally.

Alternative Fuels Data Center: Maps and Data

Science.gov Websites

-24960-10gn0o4 Annual Percent Growth of Vehicles in Operation Generated_thumb20160914-24960-10gn0o4 Last Annual Percent Growth of Vehicles in Operation 2010-2011 2011-2012 2012-2013 2013-2014 2014-2015 CNG States of America. Electric drive trains (EVs, Hydrogen, PHEVs and HEVs) experienced the greatest growth

OSO-8 soft X-ray experiment (Wisconsin)

NASA Technical Reports Server (NTRS)

1975-01-01

Information for operating and reducing data from the experiment which was designed to map low energy X-ray background emissions from 130 eV to 35 keV is presented. The detectors, counters, data system, and the gas system are discussed along with the functional operation of the subsystems. A command list indicating preconditions and resulting telemetry response for each command is included.

Regenerative braking strategies, vehicle safety and stability control systems: critical use-case proposals

NASA Astrophysics Data System (ADS)

Oleksowicz, Selim A.; Burnham, Keith J.; Southgate, Adam; McCoy, Chris; Waite, Gary; Hardwick, Graham; Harrington, Cian; McMurran, Ross

2013-05-01

The sustainable development of vehicle propulsion systems that have mainly focused on reduction of fuel consumption (i.e. CO2 emission) has led, not only to the development of systems connected with combustion processes but also to legislation and testing procedures. In recent years, the low carbon policy has made hybrid vehicles and fully electric vehicles (H/EVs) popular. The main virtue of these propulsion systems is their ability to restore some of the expended energy from kinetic movement, e.g. the braking process. Consequently new research and testing methods for H/EVs are currently being developed. This especially concerns the critical 'use-cases' for functionality tests within dynamic events for both virtual simulations, as well as real-time road tests. The use-case for conventional vehicles for numerical simulations and road tests are well established. However, the wide variety of tests and their great number (close to a thousand) creates a need for selection, in the first place, and the creation of critical use-cases suitable for testing H/EVs in both virtual and real-world environments. It is known that a marginal improvement in the regenerative braking ratio can significantly improve the vehicle range and, therefore, the economic cost of its operation. In modern vehicles, vehicle dynamics control systems play the principal role in safety, comfort and economic operation. Unfortunately, however, the existing standard road test scenarios are insufficient for H/EVs. Sector knowledge suggests that there are currently no agreed tests scenarios to fully investigate the effects of brake blending between conventional and regenerative braking as well as the regenerative braking interaction with active driving safety systems (ADSS). The paper presents seven manoeuvres, which are considered to be suitable and highly informative for the development and examination of H/EVs with regenerative braking capability. The critical manoeuvres presented are considered to be appropriate for examination of the regenerative braking mode according to ADSS. The manoeuvres are also important for investigation of regenerative braking system properties/functionalities that are specified by the legal requirements concerning H/EVs braking systems. The last part of this paper shows simulation results for one of the proposed manoeuvres that explicitly shows the usefulness of the manoeuvre.

Higher-order equation-of-motion coupled-cluster methods for ionization processes.

PubMed

Kamiya, Muneaki; Hirata, So

2006-08-21

Compact algebraic equations defining the equation-of-motion coupled-cluster (EOM-CC) methods for ionization potentials (IP-EOM-CC) have been derived and computer implemented by virtue of a symbolic algebra system largely automating these processes. Models with connected cluster excitation operators truncated after double, triple, or quadruple level and with linear ionization operators truncated after two-hole-one-particle (2h1p), three-hole-two-particle (3h2p), or four-hole-three-particle (4h3p) level (abbreviated as IP-EOM-CCSD, CCSDT, and CCSDTQ, respectively) have been realized into parallel algorithms taking advantage of spin, spatial, and permutation symmetries with optimal size dependence of the computational costs. They are based on spin-orbital formalisms and can describe both alpha and beta ionizations from open-shell (doublet, triplet, etc.) reference states into ionized states with various spin magnetic quantum numbers. The application of these methods to Koopmans and satellite ionizations of N2 and CO (with the ambiguity due to finite basis sets eliminated by extrapolation) has shown that IP-EOM-CCSD frequently accounts for orbital relaxation inadequately and displays errors exceeding a couple of eV. However, these errors can be systematically reduced to tenths or even hundredths of an eV by IP-EOM-CCSDT or CCSDTQ. Comparison of spectroscopic parameters of the FH+ and NH+ radicals between IP-EOM-CC and experiments has also underscored the importance of higher-order IP-EOM-CC treatments. For instance, the harmonic frequencies of the A 2Sigma- state of NH+ are predicted to be 1285, 1723, and 1705 cm(-1) by IP-EOM-CCSD, CCSDT, and CCSDTQ, respectively, as compared to the observed value of 1707 cm(-1). The small adiabatic energy separation (observed 0.04 eV) between the X 2Pi and a 4Sigma- states of NH+ also requires IP-EOM-CCSDTQ for a quantitative prediction (0.06 eV) when the a 4Sigma- state has the low-spin magnetic quantum number (s(z) = 1/2). When the state with s(z) = 3/2 is sought, the energy separations converge much more rapidly with the IP-EOM-CCSD value (0.03 eV) already being close to the observed (0.04 eV).

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

Bierbach, Jana; Yeung, Mark; Eckner, Erich

Surface high-harmonic generation in the relativistic regime is demonstrated as a source of extreme ultra-violet (XUV) pulses with extended operation time. Relativistic high-harmonic generation is driven by a frequency-doubled high-power Ti:Sapphire laser focused to a peak intensity of 3·1019 W/cm2 onto spooling tapes. We demonstrate continuous operation over up to one hour runtime at a repetition rate of 1 Hz. Harmonic spectra ranging from 20 eV to 70 eV (62 nm to 18 nm) were consecutively recorded by an XUV spectrometer. An average XUV pulse energy in the µJ range is measured. With the presented setup, relativistic surface high-harmonic generationmore » becomes a powerful source of coherent XUV pulses that might enable applications in, e.g. attosecond laser physics and the seeding of free-electron lasers, when the laser issues causing 80-% pulse energy fluctuations are overcome.« less

What is the Impact of Utility Demand Charges on a DCFC host

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

Francfort, James Edward

The PEV Electric Vehicle Supply Equipment (EVSE) delivered by The EV Project included both AC Level 2 and DCFC units. Over 100 of these dual-port Blink DC fast chargers were deployed by The EV Project. These DCFCs were installed in workplaces and in publicly accessible locations near traffic hubs, retail centers, parking lots, restaurants, and similar locations. The Blink DCFC is capable of charging at power up to 60 kW. Its dual-port design sequences the charge from one port to the other, delivering power to only one of two vehicles connected at a time. The actual power delivered through amore » port is determined by the PEV’s on-board battery management system (BMS). Both the power and the total energy used to recharge a PEV can represent a significant cost for the charging site host. Many electric utilities impose fees for power demand as part of their commercial rate structure. The demand charge incurred by a customer is related to the peak power used during a monthly billing cycle. This is in contrast to the cumulative total energy usage that is the more familiar utility charge seen for most residential services. A demand charge is typically assessed for the highest average power over any 15 minute interval during the monthly billing cycle. One objective of The EV Project was to identify and elucidate the motivations and barriers to potential DCFC site hosts. The application of electric utility demand charges is one such potential barrier. This subject was introduced in the paper: DC Fast Charge - Demand Charge Reduction1. It discussed demand charge impact in general terms in order to focus on potential mitigation actions. This paper identifies specific cases in order to quantify the impact of demand charges on EV Project DCFC hosts.« less

First-principles analysis of C2H2 molecule diffusion and its dissociation process on the ferromagnetic bcc-Fe110 surface.

PubMed

Ikeda, Minoru; Yamasaki, Takahiro; Kaneta, Chioko

2010-09-29

Using the projector-augmented plane wave method, we study diffusion and dissociation processes of C(2)H(2) molecules on the ferromagnetic bcc-Fe(110) surface and investigate the formation process of graphene created by C(2)H(2) molecules. The most stable site for C(2)H(2) on the Fe surface is a hollow site and its adsorption energy is - 3.5 eV. In order to study the diffusion process of the C(2)H(2) molecule, the barrier height energies for the C atom, C(2)-dimer and CH as well as the C(2)H(2) molecule are estimated using the nudged elastic band method. The barrier height energy for C(2)H(2) is 0.71 eV and this indicates that the C(2)H(2) diffuses easily on this FM bcc-Fe(110) surface. We further investigate the two step dissociation process of C(2)H(2) on Fe. The first step is the dissociation of C(2)H(2) into C(2)H and H, and the second step is that of C(2)H into C(2) and H. Their dissociation energies are 0.9 and 1.2 eV, respectively. These energies are relatively small compared to the dissociation energy 7.5 eV of C(2)H(2) into C(2)H and H in the vacuum. Thus, the Fe surface shows catalytic effects. We further investigate the initial formation process of graphene by increasing the coverage of C(2)H(2). The formation process of the benzene molecule on the FM bcc(110) surface is also discussed. We find that there exists a critical coverage of C(2)H(2) which characterizes the beginning of the formation of the graphene.

Designing Universitas Indonesia Molina EV Bus Dashboard Using ECQFD and TRIZ

NASA Astrophysics Data System (ADS)

Faiq Pradhila, Muhammad; Suzianti, Amalia; Putri Adinda, Prilly

2018-01-01

Universitas Indonesia is involved in the national electric car development program. One of the focus by the research team is to develop the Molina EV Bus which is planned to replace the current operational bus at UI so that it can be more environmental friendly. With UI developing facilities for the disabled, the Molina research team planned to make a new prototype of the Molina EV Bus to contribute to the facilities developed for the disabled. The new prototype is expected to increase the quality of the previous features of the EV Bus, including the dashboard that had been ignored. To support the development of the new prototype, this research was conducted to design a suitable dashboard for the new prototype. Design of the prototype are made using Autodesk Inventor. This research used the integration of ECQFD (Environmentally Conscious Quality Function Deployment) and TRIZ (Theory of Inventive Problem Solving) method. ECQFD was used to translate user needs into quality characteristics based on environmental aspects. TRIZ was used to translate the quality characteristics into technical specifications. This research has generated 3 sustainable, innovative, and user-preferred dashboard design recommendation for the new prototype.

The Role of Economic Uncertainty on the Block Economic Value - a New Valuation Approach / Rola Czynnika Niepewności Przy Obliczaniu Wskaźnika Rentowności - Nowe Podejście

NASA Astrophysics Data System (ADS)

Dehghani, H.; Ataee-Pour, M.

2012-12-01

The block economic value (EV) is one of the most important parameters in mine evaluation. This parameter can affect significant factors such as mining sequence, final pit limit and net present value. Nowadays, the aim of open pit mine planning is to define optimum pit limits and an optimum life of mine production scheduling that maximizes the pit value under some technical and operational constraints. Therefore, it is necessary to calculate the block economic value at the first stage of the mine planning process, correctly. Unrealistic block economic value estimation may cause the mining project managers to make the wrong decision and thus may impose inexpiable losses to the project. The effective parameters such as metal price, operating cost, grade and so forth are always assumed certain in the conventional methods of EV calculation. While, obviously, these parameters have uncertain nature. Therefore, usually, the conventional methods results are far from reality. In order to solve this problem, a new technique is used base on an invented binomial tree which is developed in this research. This method can calculate the EV and project PV under economic uncertainty. In this paper, the EV and project PV were initially determined using Whittle formula based on certain economic parameters and a multivariate binomial tree based on the economic uncertainties such as the metal price and cost uncertainties. Finally the results were compared. It is concluded that applying the metal price and cost uncertainties causes the calculated block economic value and net present value to be more realistic than certain conditions.

E/V Nautilus Detection of Isolated Features in the Eastern Pacific Ocean: Newly Discovered Calderas and Methane Seeps

NASA Astrophysics Data System (ADS)

Raineault, N.; Irish, O.; Lubetkin, M.

2016-02-01

The E/V Nautilus mapped over 80,000 km2 of the seafloor in the Gulf of Mexico and Eastern Pacific Ocean during its 2015 expedition. The Nautilus used its Kongsberg EM302 multibeam system to map the seafloor prior to remotely operated vehicle (ROV) dives, both for scientific purposes (site selection) and navigational safety. The Nautilus also routinely maps during transits to identify previously un-mapped or unresolved seafloor features. During its transit from the Galapagos Islands to the California Borderland, the Nautilus mapped 44,695 km2 of seafloor. Isolated features on the seafloor and in the water-column, such as calderas and methane seeps, were detected during this data collection effort. Operating at a frequency of 30 kHz in waters ranging from 1000-5500 m, we discovered caldera features off the coast of Central America. Since seamounts are known hotspots of biodiversity, locating new ones may enrich our understanding of seamounts as "stepping stones" for species distribution and ocean current pathways. Satellite altimetry datasets prior to this data either did not discern these calderas or recognized the presence of a bathymetric high without great detail. This new multibeam bathymetry data, gridded at 50 m, gives a precise look at these seamounts that range in elevation from 350 to 1400 m from abyssal depth. The largest of the calderas is circular in shape and is 10,000 m in length and 5,000 m in width, with a distinct circular depression at the center of its highest point, 1,400 m above the surrounding abyssal depth. In the California Borderland region, located between San Diego and Los Angeles, four new seeps were discovered in water depths from 400-1,020 m. ROV exploration of these seeps revealed vent communities. Altogether, these discoveries reinforce how little we know about the global ocean, indicate the presence of isolated deep-sea ecosystems that support biologically diverse communities, and will impact our understanding of seafloor habitat.

The Astro-H High Resolution Soft X-Ray Spectrometer

NASA Technical Reports Server (NTRS)

Kelley, Richard L.; Akamatsu, Hiroki; Azzarell, Phillip; Bialas, Tom; Boyce, Kevin R.; Brown, Gregory V.; Canavan, Edgar; Chiao, Meng P.; Costantini, Elisa; DiPirro, Michael J.;

Stationary Plasma Thruster Plume Emissions

NASA Technical Reports Server (NTRS)

Manzella, David H.

1994-01-01

The emission spectrum from a xenon plasma produced by a Stationary Plasma Thruster provided by the Ballistic Missile Defense Organization (BMDO) was measured. Approximately 270 individual Xe I, Xe II, and XE III transitions were identified. A total of 250 mW of radiated optical emission was estimated from measurements taken at the thruster exit plane. There was no evidence of erosion products in the emission signature. Ingestion and ionization of background gas at elevated background pressure was detected. The distribution of excited states could be described by temperatures ranging from fractions of 1 eV to 4 eV with a high degree of uncertainty due to the nonequilibrium nature of this plasma. The plasma was over 95 percent ionized at the thruster exit plane. Between 10 and 20 percent of the ions were doubly charged. Two modes of operation were identified. The intensity of plasma emission increased by a factor of two during operation in an oscillatory mode. The transfer between the two modes of operation was likely related to unidentified phenomena occurring on a time scale of minutes.

Active implantable medical device EMI assessment for wireless power transfer operating in LF and HF bands.

PubMed

Hikage, Takashi; Nojima, Toshio; Fujimoto, Hiroshi

2016-06-21

The electromagnetic interference (EMI) imposed on active implantable medical devices by wireless power transfer systems (WPTSs) is discussed based upon results of in vitro experiments. The purpose of this study is to present comprehensive EMI test results gathered from implantable-cardiac pacemakers and implantable cardioverter defibrillators exposed to the electromagnetic field generated by several WPTSs operating in low-frequency (70 kHz-460 kHz) and high-frequency (6.78 MHz) bands. The constructed in vitro experimental test system based upon an Irnich's flat torso phantom was applied. EMI test experiments are conducted on 14 types of WPTSs including Qi-compliant system and EV-charging WPT system mounted on current production EVs. In addition, a numerical simulation model for active implantable medical device (AIMD) EMI estimation based on the experimental test system is newly proposed. The experimental results demonstrate the risk of WPTSs emitting intermittent signal to affect the correct behavior of AIMDs when operating at very short distances. The proposed numerical simulation model is applicable to obtain basically the EMI characteristics of various types of WPTSs.

Plasma physics analysis of SERT-2 operation

NASA Technical Reports Server (NTRS)

Kaufman, H. R.

1980-01-01

An analysis of the major plasma processes involved in the SERT 2 spacecraft experiments was conducted to aid in the interpretation of recent data. A plume penetration model was developed for neutralization electron conduction to the ion beam and showed qualitative agreement with flight data. In the SERT 2 configuration conduction of neutralization electrons between thrusters was experimentally demonstrated in space. The analysis of this configuration suggests that the relative orientation of the two magnetic fields was an important factor in the observed results. Specifically, the opposed field orientation appeared to provide a high conductivity channel between thrusters and a barrier to the ambient low energy electrons in space. The SERT 2 neutralizer currents with negative neutralizer biases were up to about twice the theoretical prediction for electron collection by the ground screen. An explanation for the higher experimental values was a possible conductive path from the neutralizer plume to a nearby part of the ground screen. Plasma probe measurements of SERT 2 gave the clearest indication of plasma electron temperature, with normal operation being near 5 eV and discharge only operation near 2 eV.

Straight and chopped dc performance data for a General Electric 5BT 2366C10 motor and an EV-1 controller

NASA Technical Reports Server (NTRS)

Edie, P. C.

1981-01-01

Performance data on the General Electric 5BT 2366C10 series wound dc motor and EV-1 Chopper Controller is supplied for the electric vehicle manufacturer. Data is provided for both straight and chopped dc input to the motor, at 2 motor temperature levels. Testing was done at 6 voltage increments to the motor, and 2 voltage increments to the controller. Data results are presented in both tabular and graphical forms. Tabular information includes motor voltage and current input data, motor speed and torque output data, power data and temperature data. Graphical information includes torque-speed, motor power output-speed, torque-current, and efficiency-speed plots under the various operating conditions. The data resulting from this testing shows the speed-torque plots to have the most variance with operating temperature. The maximum motor efficiency is between 86% and 87%, regardless of temperature or mode of operation. When the chopper is utilized, maximum motor efficiency occurs when the chopper duty cycle approaches 100%.

Active implantable medical device EMI assessment for wireless power transfer operating in LF and HF bands

NASA Astrophysics Data System (ADS)

Hikage, Takashi; Nojima, Toshio; Fujimoto, Hiroshi

2016-06-01

The electromagnetic interference (EMI) imposed on active implantable medical devices by wireless power transfer systems (WPTSs) is discussed based upon results of in vitro experiments. The purpose of this study is to present comprehensive EMI test results gathered from implantable-cardiac pacemakers and implantable cardioverter defibrillators exposed to the electromagnetic field generated by several WPTSs operating in low-frequency (70 kHz-460 kHz) and high-frequency (6.78 MHz) bands. The constructed in vitro experimental test system based upon an Irnich’s flat torso phantom was applied. EMI test experiments are conducted on 14 types of WPTSs including Qi-compliant system and EV-charging WPT system mounted on current production EVs. In addition, a numerical simulation model for active implantable medical device (AIMD) EMI estimation based on the experimental test system is newly proposed. The experimental results demonstrate the risk of WPTSs emitting intermittent signal to affect the correct behavior of AIMDs when operating at very short distances. The proposed numerical simulation model is applicable to obtain basically the EMI characteristics of various types of WPTSs.

The Astro-H high resolution soft x-ray spectrometer

NASA Astrophysics Data System (ADS)

Kelley, Richard L.; Akamatsu, Hiroki; Azzarello, Phillipp; Bialas, Tom; Boyce, Kevin R.; Brown, Gregory V.; Canavan, Edgar; Chiao, Meng P.; Costantini, Elisa; DiPirro, Michael J.; Eckart, Megan E.; Ezoe, Yuichiro; Fujimoto, Ryuichi; Haas, Daniel; den Herder, Jan-Willem; Hoshino, Akio; Ishikawa, Kumi; Ishisaki, Yoshitaka; Iyomoto, Naoko; Kilbourne, Caroline A.; Kimball, Mark O.; Kitamoto, Shunji; Konami, Saori; Koyama, Shu; Leutenegger, Maurice A.; McCammon, Dan; Mitsuda, Kazuhisa; Mitsuishi, Ikuyuki; Moseley, Harvey; Murakami, Hiroshi; Murakami, Masahide; Noda, Hirofumi; Ogawa, Mina; Ohashi, Takaya; Okamoto, Atsushi; Ota, Naomi; Paltani, Stéphane; Porter, F. S.; Sakai, Kazuhiro; Sato, Kosuke; Sato, Yohichi; Sawada, Makoto; Seta, Hiromi; Shinozaki, Keisuke; Shirron, Peter J.; Sneiderman, Gary A.; Sugita, Hiroyuki; Szymkowiak, Andrew E.; Takei, Yoh; Tamagawa, Toru; Tashiro, Makoto; Terada, Yukikatsu; Tsujimoto, Masahiro; de Vries, Cor P.; Yamada, Shinya; Yamasaki, Noriko Y.; Yatsu, Yoichi

2016-07-01

We present the overall design and performance of the Astro-H (Hitomi) Soft X-Ray Spectrometer (SXS). The instrument uses a 36-pixel array of x-ray microcalorimeters at the focus of a grazing-incidence x-ray mirror Soft X-Ray Telescope (SXT) for high-resolution spectroscopy of celestial x-ray sources. The instrument was designed to achieve an energy resolution better than 7 eV over the 0.3-12 keV energy range and operate for more than 3 years in orbit. The actual energy resolution of the instrument is 4-5 eV as demonstrated during extensive ground testing prior to launch and in orbit. The measured mass flow rate of the liquid helium cryogen and initial fill level at launch predict a lifetime of more than 4 years assuming steady mechanical cooler performance. Cryogen-free operation was successfully demonstrated prior to launch. The successful operation of the SXS in orbit, including the first observations of the velocity structure of the Perseus cluster of galaxies, demonstrates the viability and power of this technology as a tool for astrophysics.

Asteroid Redirect Mission Proximity Operations for Reference Target Asteroid 2008 EV5

NASA Technical Reports Server (NTRS)

Reeves, David M.; Mazanek, Daniel D.; Cichy, Benjamin D.; Broschart, Steve B.; Deweese, Keith D.

2016-01-01

NASA's Asteroid Redirect Mission (ARM) is composed of two segments, the Asteroid Redirect Robotic Mission (ARRM), and the Asteroid Redirect Crewed Mission (ARCM). In March of 2015, NASA selected the Robotic Boulder Capture Option1 as the baseline for the ARRM. This option will capture a multi-ton boulder, (typically 2-4 meters in size) from the surface of a large (greater than approx.100 m diameter) Near-Earth Asteroid (NEA) and return it to cis-lunar space for subsequent human exploration during the ARCM. Further human and robotic missions to the asteroidal material would also be facilitated by its return to cis-lunar space. In addition, prior to departing the asteroid, the Asteroid Redirect Vehicle (ARV) will perform a demonstration of the Enhanced Gravity Tractor (EGT) planetary defense technique2. This paper will discuss the proximity operations which have been broken into three phases: Approach and Characterization, Boulder Capture, and Planetary Defense Demonstration. Each of these phases has been analyzed for the ARRM reference target, 2008 EV5, and a detailed baseline operations concept has been developed.

Salivary extracellular vesicle-associated miRNAs as potential biomarkers in oral squamous cell carcinoma.

PubMed

Gai, Chiara; Camussi, Francesco; Broccoletti, Roberto; Gambino, Alessio; Cabras, Marco; Molinaro, Luca; Carossa, Stefano; Camussi, Giovanni; Arduino, Paolo G

2018-04-18

Several studies in the past have investigated the expression of micro RNAs (miRNAs) in saliva as potential biomarkers. Since miRNAs associated with extracellular vesicles (EVs) are known to be protected from enzymatic degradation, we evaluated whether salivary EVs from patients with oral squamous cell carcinoma (OSCC) were enriched with specific subsets of miRNAs. OSCC patients and controls were matched with regards to age, gender and risk factors. Total RNA was extracted from salivary EVs and the differential expression of miRNAs was evaluated by qRT-PCR array and qRT-PCR. The discrimination power of up-regulated miRNAs as biomarkers in OSCC patients versus controls was evaluated by the Receiver Operating Characteristic (ROC) curves. A preliminary qRT-PCR array was performed on samples from 5 OSCC patients and 5 healthy controls whereby a subset of miRNAs were identified that were differentially expressed. On the basis of these results, a cohort of additional 16 patients and 6 controls were analyzed to further confirm the miRNAs that were up-regulated or selectively expressed in the previous pilot study. The following miRNAs: miR-302b-3p and miR-517b-3p were expressed only in EVs from OSCC patients and miR-512-3p and miR-412-3p were up-regulated in salivary EVs from OSCC patients compared to controls with the ROC curve showing a good discrimination power for OSCC diagnosis. The Kyoto Encyclopedia of Gene and Genomes (KEGG) pathway analysis suggested the possible involvement of the miRNAs identified in pathways activated in OSCC. In this work, we suggest that salivary EVs isolated by a simple charge-based precipitation technique can be exploited as a non-invasive source of miRNAs for OSCC diagnosis. Moreover, we have identified a subset of miRNAs selectively enriched in EVs of OSCC patients that could be potential biomarkers.

Electric vehicle fleet implications and analysis : final research project report.

DOT National Transportation Integrated Search

2016-11-01

The objective of this project was to evaluate the implementation and effectiveness of : electric vehicles (EVs) used in fleet operations. The study focuses on Battery-Electric : Vehicles (BEVs) and Plug-In Hybrid Electric Vehicles (PHEVs); collective...

ELENA MCP detector: absolute detection efficiency for low-energy neutral atoms

NASA Astrophysics Data System (ADS)

Rispoli, R.; De Angelis, E.; Colasanti, L.; Vertolli, N.; Orsini, S.; Scheer, J. A.; Mura, A.; Milillo, A.; Wurz, P.; Selci, S.; Di Lellis, A. M.; Leoni, R.; D'Alessandro, M.; Mattioli, F.; Cibella, S.

2012-09-01

Microchannel Plates (MCP) detectors are frequently used in space instrumentation for detecting a wide range of radiation and particles. In particular, the capability to detect non-thermal low energy neutral species is crucial for the sensor ELENA (Emitted Low-Energy Neutral Atoms), part of the package SERENA (Search for Exospheric Refilling and Emitted Natural Abundances) on board the BepiColombo mission of ESA to Mercury to be launched in 2015. ELENA is a Time of Flight (TOF) sensor, based on a novel concept using an ultra-sonic oscillating shutter (Start section), which is operated at frequencies up to 50 kHz; a MCP detector is used as a Stop detector. The scientific objective of ELENA is to detect energetic neutral atoms in the range 10 eV - 5 keV, within 76° FOV, perpendicular to the S/C orbital plane. ELENA will monitor the emission of neutral atoms from the whole surface of Mercury thanks to the spacecraft motion. The major scientific objectives are the interaction between the plasma environment and the planet’s surface, the global particle loss-rate and the remote sensing of the surface properties. In particular, surface release processes are investigated by identifying particles released from the surface, via solar wind-induced ion sputtering (< 1eV - < 100 eV) as well as Hydrogen back-scattered at hundreds eV. MCP absolute detection efficiency for very low energy neutral atoms (E < 30 eV) is a crucial point for this investigation. At the MEFISTO facility of the Physical Institute of the University of Bern (CH), measurements on three different types of MCP (with and without coating) have been performed providing the detection efficiencies in the energy range 10eV - 1keV. Outcomes from such measurements are discussed here.

ELENA MCP detector: absolute efficiency measurement for low energy neutral atoms

NASA Astrophysics Data System (ADS)

Rispoli, R.; De Angelis, E.; Colasanti, L.; Vertolli, N.; Orsini, S.; Scheer, J.; Mura, A.; Milillo, A.; Wurz, P.; Selci, S.; Di Lellis, A. M.; Leoni, R.; D'Alessandro, M.; Mattioli, F.; Cibella, S.

2012-04-01

MicroChannel plates (MCP) detectors are frequently used in space instrumentation for detecting a wide range of radiation and particles. In particular, the capability to detect non-thermal low energy neutral species is crucial for the sensor ELENA (Emitted Low-Energy Neutral Atoms), part of the package SERENA (Search for Exospheric Refilling and Emitted Natural Abundances) on board the BepiColombo mission to Mercury to be launched in 2014. ELENA is a TOF sensor, based on a novel concept ultra-sonic oscillating shutter (Start section)which is operated at frequencies up to 50 kHz; a MCP detector is used as a Stop section. It is aimed to detect neutral atoms in the range 10 eV - 5 keV, within 70° FOV, perpendicular to the S/C orbital plane. ELENA will monitor the emission of neutral atoms from the whole surface of Mercury thanks to the spacecraft motion. The major scientific objectives are the interaction between the environment and the planet, the global particle loss-rate and the remote sensing of the surface properties. In particular, surface release processes are investigated by identifying particles release from the surface, via solar wind-induced ion sputtering (<1eV and >100 eV) as well as Hydrogen back-scattered at hundreds eV. MCP absolute detection efficiency for very low energy neutral atoms (E< 30eV) is a crucial point not yet investigated. At the MEFISTO facility of the Physical Institute of University of Bern (CH), measurements on three different type of MCPs coating have been performed providing the behaviors of MCP detection efficiency in the range 10eV-1keV. Outcomes from such measurements are here discussed.

DNA strand breaks and crosslinks induced by transient anions in the range 2-20 eV

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

Luo, Xinglan; Zheng, Yi, E-mail: Yizheng@fzu.edu.cn; Sanche, Léon

2014-04-21

The energy dependence of the yields of single and double strand breaks (SSB and DSB) and crosslinks induced by electron impact on plasmid DNA films is measured in the 2-20 eV range. The yield functions exhibit two strong maxima, which are interpreted to result from the formation of core-excited resonances (i.e., transient anions) of the bases, and their decay into the autoionization channel, resulting in π → π{sup *} electronic transitions of the bases followed by electron transfer to the C–O σ{sup *} bond in the phosphate group. Occupancy of the σ{sup *} orbital ruptures the C–O bond of themore » backbone via dissociative electron attachment, producing a SSB. From a comparison of our results with those of other works, including theoretical calculations and electron-energy-loss spectra of the bases, the 4.6 eV peak in the SSB yield function is attributed to the resonance decay into the lowest electronically excited states of the bases; in particular, those resulting from the transitions 1{sup 3}A{sup ′} (π{sub 2} → π{sub 3}{sup *}) and 1{sup 3}A{sup ″} (n{sub 2} → π{sub 3}{sup *}) of thymine and 1{sup 3}A{sup ′} (π → π{sup *}) of cytosine. The strongest peak at 9.6 eV in the SSB yield function is also associated with electron captured by excited states of the bases, resulting mostly from a multitude of higher-energy π → π{sup *} transitions. The DSB yield function exhibits strong maxima at 6.1 and 9.6 eV. The peak at 9.6 eV is probably related to the same resonance manifold as that leading to SSB, but the other at 6.1 eV may be more restricted to decay into the electronic state 1{sup 3}A{sup ′} (π → π{sup *}) of cytosine via autoionization. The yield function of crosslinks is dominated by a broad peak extending over the 3.6-11.6 eV range with a sharper one at 17.6 eV. The different line shape of the latter function, compared to that of SSB and DSB, appears to be due to the formation of reactive radical sites in the initial supercoiled configuration of the plasmid, which react with the circular form (i.e., DNA with a SSB) to produce a crosslink.« less

Spectroscopic determination of surface geometry: Ti(0001)-H(1×1)

NASA Astrophysics Data System (ADS)

Feibelman, Peter J.; Hamann, D. R.

1980-02-01

The electronic structure of a Ti(0001) film covered by a monolayer of H is shown to depend strongly on the location of the H atom in the surface unit cell. Best agreement with experiment is found with the H's in three-fold sites, 0.8 a.u. outside the outer Ti layer. In this geometry the H atoms "heal" the surface-the clean Ti(0001) surface state near the Fermi level is removed and the outer layer d-like local density of states (LDOS) is quite similar to that of the interior. Additionally, the calculated work function is 4.0 eV and an H-derived peak in the calculated LDOS appears 5 eV below EF, in agreement with photoemission measurements.

Carbon dioxide is tightly bound in the [Co(Pyridine)(CO2)]- anionic complex

NASA Astrophysics Data System (ADS)

Graham, Jacob D.; Buytendyk, Allyson M.; Zhang, Xinxing; Kim, Seong K.; Bowen, Kit H.

2015-11-01

The [Co(Pyridine)(CO2)]- anionic complex was studied through the combination of photoelectron spectroscopy and density functional theory calculations. This complex was envisioned as a primitive model system for studying CO2 binding to negatively charged sites in metal organic frameworks. The vertical detachment energy (VDE) measured via the photoelectron spectrum is 2.7 eV. Our calculations imply a structure for [Co(Pyridine)(CO2)]- in which a central cobalt atom is bound to pyridine and CO2 moieties on either sides. This structure was validated by acceptable agreement between the calculated and measured VDE values. Based on our calculations, we found CO2 to be bound within the anionic complex by 1.4 eV.

Carbon dioxide is tightly bound in the [Co(Pyridine)(CO2)](-) anionic complex.

PubMed

Graham, Jacob D; Buytendyk, Allyson M; Zhang, Xinxing; Kim, Seong K; Bowen, Kit H

2015-11-14

The [Co(Pyridine)(CO2)](-) anionic complex was studied through the combination of photoelectron spectroscopy and density functional theory calculations. This complex was envisioned as a primitive model system for studying CO2 binding to negatively charged sites in metal organic frameworks. The vertical detachment energy (VDE) measured via the photoelectron spectrum is 2.7 eV. Our calculations imply a structure for [Co(Pyridine)(CO2)](-) in which a central cobalt atom is bound to pyridine and CO2 moieties on either sides. This structure was validated by acceptable agreement between the calculated and measured VDE values. Based on our calculations, we found CO2 to be bound within the anionic complex by 1.4 eV.

NH3 adsorption on anatase-TiO2(101)

NASA Astrophysics Data System (ADS)

Koust, Stig; Adamsen, Kræn C.; Kolsbjerg, Esben Leonhard; Li, Zheshen; Hammer, Bjørk; Wendt, Stefan; Lauritsen, Jeppe V.

2018-03-01

The adsorption of ammonia on anatase TiO2 is of fundamental importance for several catalytic applications of TiO2 and for probing acid-base interactions. Utilizing high-resolution scanning tunneling microscopy (STM), synchrotron X-ray photoelectron spectroscopy, temperature-programmed desorption (TPD), and density functional theory (DFT), we identify the adsorption mode and quantify the adsorption strength on the anatase TiO2(101) surface. It was found that ammonia adsorbs non-dissociatively as NH3 on regular five-fold coordinated titanium surface sites (5f-Ti) with an estimated exothermic adsorption energy of 1.2 eV for an isolated ammonia molecule. For higher adsorbate coverages, the adsorption energy progressively shifts to smaller values, due to repulsive intermolecular interactions. The repulsive adsorbate-adsorbate interactions are quantified using DFT and autocorrelation analysis of STM images, which both showed a repulsive energy of ˜50 meV for nearest neighbor sites and a lowering in binding energy for an ammonia molecule in a full monolayer of 0.28 eV, which is in agreement with TPD spectra.

Parallel Harmony Search Based Distributed Energy Resource Optimization

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

Ceylan, Oguzhan; Liu, Guodong; Tomsovic, Kevin

2015-01-01

This paper presents a harmony search based parallel optimization algorithm to minimize voltage deviations in three phase unbalanced electrical distribution systems and to maximize active power outputs of distributed energy resources (DR). The main contribution is to reduce the adverse impacts on voltage profile during a day as photovoltaics (PVs) output or electrical vehicles (EVs) charging changes throughout a day. The IEEE 123- bus distribution test system is modified by adding DRs and EVs under different load profiles. The simulation results show that by using parallel computing techniques, heuristic methods may be used as an alternative optimization tool in electricalmore » power distribution systems operation.« less

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

Franke, J.-H.; Kosov, D. S.

We study the adsorption and ring-opening of lactide on the naturally chiral metal surface Pt(321){sup S}. Lactide is a precursor for polylactic acid ring-opening polymerization, and Pt is a well known catalyst surface. We study, here, the energetics of the ring-opening of lactide on a surface that has a high density of kink atoms. These sites are expected to be present on a realistic Pt surface and show enhanced catalytic activity. The use of a naturally chiral surface also enables us to study potential chiral selectivity effects of the reaction at the same time. Using density functional theory with amore » functional that includes the van der Waals forces in a first-principles manner, we find modest adsorption energies of around 1.4 eV for the pristine molecule and different ring-opened states. The energy barrier to be overcome in the ring-opening reaction is found to be very small at 0.32 eV and 0.30 eV for LL- and its chiral partner DD-lactide, respectively. These energies are much smaller than the activation energy for a dehydrogenation reaction of 0.78 eV. Our results thus indicate that (a) ring-opening reactions of lactide on Pt(321) can be expected already at very low temperatures, and Pt might be a very effective catalyst for this reaction; (b) the ring-opening reaction rate shows noticeable enantioselectivity.« less

Hyperthermal (1-100 eV) nitrogen ion scattering damage to D-ribose and 2-deoxy-D-ribose films.

PubMed

Deng, Zongwu; Bald, Ilko; Illenberger, Eugen; Huels, Michael A

2007-10-14

Highly charged heavy ion traversal of a biological medium can produce energetic secondary fragment ions. These fragment ions can in turn cause collisional and reactive scattering damage to DNA. Here we report hyperthermal (1-100 eV) scattering of one such fragment ion (N(+)) from biologically relevant sugar molecules D-ribose and 2-deoxy-D-ribose condensed on polycrystalline Pt substrate. The results indicate that N(+) ion scattering at kinetic energies down to 10 eV induces effective decomposition of both sugar molecules and leads to the desorption of abundant cation and anion fragments. Use of isotope-labeled molecules (5-(13)C D-ribose and 1-D D-ribose) partly reveals some site specificity of the fragment origin. Several scattering reactions are also observed. Both ionic and neutral nitrogen atoms abstract carbon from the molecules to form CN(-) anion at energies down to approximately 5 eV. N(+) ions also abstract hydrogen from hydroxyl groups of the molecules to form NH(-) and NH(2) (-) anions. A fraction of OO(-) fragments abstract hydrogen to form OH(-). The formation of H(3)O(+) ions also involves hydrogen abstraction as well as intramolecular proton transfer. These findings suggest a variety of severe damaging pathways to DNA molecules which occur on the picosecond time scale following heavy ion irradiation of a cell, and prior to the late diffusion-limited homogeneous chemical processes.

Near sulfur L-edge X-ray absorption spectra of methanethiol in isolation and adsorbed on a Au(111) surface: a theoretical study using the four-component static exchange approximation.

PubMed

Villaume, Sebastien; Ekström, Ulf; Ottosson, Henrik; Norman, Patrick

2010-06-07

The relativistic four-component static exchange approach for calculation of near-edge X-ray absorption spectra has been reviewed. Application of the method is made to the Au(111) interface and the adsorption of methanethiol by a study of the near sulfur L-edge spectrum. The binding energies of the sulfur 2p(1/2) and 2p(3/2) sublevels in methanethiol are determined to be split by 1.2 eV due to spin-orbit coupling, and the binding energy of the 2p(3/2) shell is lowered from 169.2 eV for the isolated system to 167.4 and 166.7-166.8 eV for methanethiol in mono- and di-coordinated adsorption sites, respectively (with reference to vacuum). In the near L-edge X-ray absorption fine structure spectrum only the sigma*(S-C) peak at 166 eV remains intact by surface adsorption, whereas transitions of predominantly Rydberg character are largely quenched in the surface spectra. The sigma*(S-H) peak of methanethiol is replaced by low-lying, isolated, sigma*(S-Au) peak(s), where the number of peaks in the latter category and their splittings are characteristic of the local bonding situation of the sulfur.

Temperature dependence of deuterium retention mechanisms in tungsten

NASA Astrophysics Data System (ADS)

Roszell, J. P.; Davis, J. W.; Haasz, A. A.

2012-10-01

The retention of 500 eV D+ was measured as a function of implantation temperature in single- (SCW) and poly-crystalline (PCW) tungsten. The results show a decrease in retention of ˜2 orders of magnitude over the temperature range of 350-550 K in SCW and a decrease of an order of magnitude over the temperature range of 600-700 K in PCW. Inspection of the TDS spectra showed a shift in peak location from 600 to 800 K as temperature was increased above 350 K in SCW and above 450 K in PCW specimens. TMAP modeling showed that the change in peak location corresponds to a change in trapping energy from 1.3 eV for the 600 K peak to 2.1 eV for the 800 K peak. It is proposed that for implantations performed above 350 K in SCW and 450 K in PCW, deuterium-containing vacancies are able to diffuse and combine to create stable nano-bubbles within the crystal lattice. The formation of nano-bubbles due to the annihilation of deuterium-vacancy complexes results in a change in the trapping energy from 1.3 to 2.1 eV as well as a decrease in retention as some of the deuterium-vacancy complexes will be destroyed at surfaces or grain boundaries, decreasing the number of trapping sites available.

Theoretical study on electronic structure of bathocuproine: Renormalization of the band gap in the crystalline state and the large exciton binding energy

NASA Astrophysics Data System (ADS)

Yanagisawa, Susumu; Hatada, Shin-No-Suke; Morikawa, Yoshitada

Bathocuproine (BCP) is a promising organic material of a hole blocking layer in organic light-emitting diodes or an electron buffer layer in organic photovoltaic cells. The nature of the unoccupied electronic states is a key characteristic of the material, which play vital roles in the electron transport. To elucidate the electronic properties of the molecular or crystalline BCP, we use the GW approximation for calculation of the fundamental gap, and the long-range corrected density functional theory for the molecular optical absorption. It is found that the band gap of the BCP single crystal is 4.39 eV, and it is in agreement with the recent low-energy inverse photoemission spectroscopy measurement. The polarization energy is estimated to be larger than 1 eV, demonstrating the large polarization effects induced by the electronic clouds surrounding the injected charge. The theoretical optical absorption energy is 3.68 eV, and the exciton binding energy is estimated to be 0.71 eV, implying the large binding in the eletron-hole pair distributed around the small part of the molecular region. This work was supported by the Grants-in-Aid for Young Scientists (B) (No. 26810009), and for Scientific Research on Innovative Areas ``3D Active-Site Science'' (No. 26105011) from Japan Society for the Promotion of Science.

Customer Relationship Management.

ERIC Educational Resources Information Center

Fayerman, Michael

2002-01-01

Presents an approach increasingly employed by businesses to track and respond to their customers to provide better and faster services: customer relationship management. Discusses its applicability to the operations of higher education and institutional research and the role it plays in the knowledge management framework. (EV)

Ce3+ luminescent centers of different symmetries in KMgF3 single crystals

NASA Astrophysics Data System (ADS)

Francini, R.; Grassano, U. M.; Landi, L.; Scacco, A.; D'elena, M.; Nikl, M.; Cechova, N.; Zema, N.

1997-12-01

Absorption, emission, and excitation spectra of KMgF3 doped with Ce3+ have been measured in the near ultraviolet up to 180 nm. In this fluoroperovskite lattice, absorption of the Ce3+ impurity is found at energies higher than 4.4 eV. Broad-band emissions are measured at 350 nm and 275 nm which are identified as the 5d-->4f radiative recombination at two different Ce3+ centers. The same substitutional site is proposed for both centers, with the unperturbed site rapidly saturating with an increasing concentration of Ce3+ in favor of a site perturbed by two K+-ion vacancies.

Multiple core-hole formation by free-electron laser radiation in molecular nitrogen

NASA Astrophysics Data System (ADS)

Banks, H. I. B.; Little, D. A.; Emmanouilidou, A.

2018-05-01

We investigate the formation of multiple-core-hole states of molecular nitrogen interacting with a free-electron laser pulse. In previous work, we obtained bound and continuum molecular orbitals in the single-center expansion scheme and used these orbitals to calculate photo-ionization and auger decay rates. We extend our formulation to track the proportion of the population that accesses single-site versus two-site double-core-hole (TSDCH) states, before the formation of the final atomic ions. We investigate the pulse parameters that favor the formation of the single-site and TSDCH as well as triple-core-hole states for 525 and 1100 eV photons.

Simulation studies for operating electron beam ion trap at very low energy for disentangling edge plasma spectra

NASA Astrophysics Data System (ADS)

Jin, Xuelong; Fei, Zejie; Xiao, Jun; Lu, Di; Hutton, Roger; Zou, Yaming

2012-07-01

Electron beam ion traps (EBITs) are very useful tools for disentanglement studies of atomic processes in plasmas. In order to assist studies on edge plasma spectroscopic diagnostics, a very low energy EBIT, SH-PermEBIT, has been set up at the Shanghai EBIT lab. In this work, simulation studies for factors which hinder an EBIT to operate at very low electron energies were made based on the Tricomp (Field Precision) codes. Longitudinal, transversal, and total kinetic energy distributions were analyzed for all the electron trajectories. Influences from the electron current and electron energy on the energy depression caused by the space charge are discussed. The simulation results show that although the energy depression is most serious along the center of the electron beam, the electrons in the outer part of the beam are more likely to be lost when an EBIT is running at very low energy. Using the simulation results to guide us, we successfully managed to reach the minimum electron beam energy of 60 eV with a beam transmission above 57% for the SH-PermEBIT. Ar and W spectra were measured from the SH-PermEBIT at the apparent electron beam energies (read from the voltage difference between the electron gun cathode and the central drift tube) of 60 eV and 1200 eV, respectively. The spectra are shown in this paper.

Multi-parameter Nonlinear Gain Correction of X-ray Transition Edge Sensors for the X-ray Integral Field Unit

NASA Astrophysics Data System (ADS)

Cucchetti, E.; Eckart, M. E.; Peille, P.; Porter, F. S.; Pajot, F.; Pointecouteau, E.

2018-04-01

With its array of 3840 Transition Edge Sensors (TESs), the Athena X-ray Integral Field Unit (X-IFU) will provide spatially resolved high-resolution spectroscopy (2.5 eV up to 7 keV) from 0.2 to 12 keV, with an absolute energy scale accuracy of 0.4 eV. Slight changes in the TES operating environment can cause significant variations in its energy response function, which may result in systematic errors in the absolute energy scale. We plan to monitor such changes at pixel level via onboard X-ray calibration sources and correct the energy scale accordingly using a linear or quadratic interpolation of gain curves obtained during ground calibration. However, this may not be sufficient to meet the 0.4 eV accuracy required for the X-IFU. In this contribution, we introduce a new two-parameter gain correction technique, based on both the pulse-height estimate of a fiducial line and the baseline value of the pixels. Using gain functions that simulate ground calibration data, we show that this technique can accurately correct deviations in detector gain due to changes in TES operating conditions such as heat sink temperature, bias voltage, thermal radiation loading and linear amplifier gain. We also address potential optimisations of the onboard calibration source and compare the performance of this new technique with those previously used.

Nonstationary phenomena in cosmic rays with E 0 ≤ 1018 eV according to the data of the Yakutsk EAS array

NASA Astrophysics Data System (ADS)

Glushkov, A. V.; Pravdin, M. I.

2012-07-01

The energy spectrum of cosmic rays and the fraction of muons with the threshold 1.0secθ GeV in the total number of charged particles in extensive air showers with energy E 0 ≥ 1017 eV according to Yakutsk array data collected during 35 years of its continuous operation in 1978-2012 have been analyzed. It has been shown that these characteristics are noticeably different in different time periods. Before 1996, the integral intensity of the spectrum at E 0 = 1017 eV varied near one stable position and then began to increase. It increased by (45 ± 5)% in seven years and, then, began to decrease. This phenomenon was accompanied a similar change in the fraction of muons and was caused by a significant increase in the average weight of the chemical composition of cosmic rays after 1996 as compared to preceding years.

KASCADE-Grande experiment measurements of the cosmic ray spectrum and large scale anisotropy

NASA Astrophysics Data System (ADS)

Chiavassa, A.; Apel, W. D.; Arteaga-Velázquez, J. C.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Fuhrmann, D.; Gherghel-Lascu, A.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Palmieri, N.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schoo, S.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Zabierowski, J.; KASCADE-Grande Collaboration

2016-10-01

The KASCADE-Grande experiment operated at KIT from January 2004 to November 2012, measuring Extensive Air Showers (EAS) generated by primary cosmic rays in the 1016-1018 eV energy range. The experiment measured, for each single event, with a high resolution, the total number of charged particles (Nch) and of muons (Nμ). In this contribution we summarize the results obtained about: (i) the measurement of the all particle energy spectrum, discussing the influence of the hadronic interaction model used to derive the energy calibration of the experimental data. (ii) The energy spectra derived separating the events according to the Nμ /Nch ratio. This technique allowed us to unveil a steepening of the spectrum of heavy primaries at E ˜10 16.92 ± 0.04 eV and a hardening of the spectrum of light primaries at E ˜10 17.08 ± 0.08 eV. (ii) A search for large scale anisotropies.

Latest results from the KASCADE-Grande experiment

NASA Astrophysics Data System (ADS)

Chiavassa, A.; Apel, W. D.; Arteaga-Velázquez, J. C.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Cossavella, F.; Curcio, C.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Fuchs, B.; Fuhrmann, D.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Mayer, H. J.; Melissas, M.; Milke, J.; Mitrica, B.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schoo, S.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Zabierowski, J.

2014-04-01

The KASCADE-Grande experiment operated at KIT from January 2004 to November 2012, measuring EAS generated by primary cosmic rays in the 1016-1018 eV energy range. The experiment detected, for each single event, with a high resolution, the total number of charged particles (Nch) and of muons (Nμ). In this contribution we present the latest results about: The measurement of the all particle energy spectrum, discussing the influence of the hadronic interaction model used to derive the energy calibration of the experimental data. The energy spectra derived separating the events according to the Nμ /Nch ratio. This technique allowed us to unveil a steepening of the spectrum of heavy primaries at E ~10 16.92 ± 0.04 eV and a hardening of the spectrum of light primaries at E ~10 17.08 ± 0.08 eV. The elemental spectra (for five mass groups) obtained applying a detailed unfolding analysis technique. A search for large scale anisotropies.

Informatics-Aided Density Functional Theory Study on the Li Ion Transport of Tavorite-Type LiMTO4F (M(3+)-T(5+), M(2+)-T(6+)).

PubMed

Jalem, Randy; Kimura, Mayumi; Nakayama, Masanobu; Kasuga, Toshihiro

2015-06-22

The ongoing search for fast Li-ion conducting solid electrolytes has driven the deployment surge on density functional theory (DFT) computation and materials informatics for exploring novel chemistries before actual experimental testing. Existing structure prototypes can now be readily evaluated beforehand not only to map out trends on target properties or for candidate composition selection but also for gaining insights on structure-property relationships. Recently, the tavorite structure has been determined to be capable of a fast Li ion insertion rate for battery cathode applications. Taking this inspiration, we surveyed the LiMTO4F tavorite system (M(3+)-T(5+) and M(2+)-T(6+) pairs; M is nontransition metals) for solid electrolyte use, identifying promising compositions with enormously low Li migration energy (ME) and understanding how structure parameters affect or modulate ME. We employed a combination of DFT computation, variable interaction analysis, graph theory, and a neural network for building a crystal structure-based ME prediction model. Candidate compositions that were predicted include LiGaPO4F (0.25 eV), LiGdPO4F (0.30 eV), LiDyPO4F (0.30 eV), LiMgSO4F (0.21 eV), and LiMgSeO4F (0.11 eV). With chemical substitutions at M and T sites, competing effects among Li pathway bottleneck size, polyanion covalency, and local lattice distortion were determined to be crucial for controlling ME. A way to predict ME for multiple structure types within the neural network framework was also explored.

Computerizing Maintenance Management Improves School Processes.

ERIC Educational Resources Information Center

Conroy, Pat

2002-01-01

Describes how a Computerized Maintenance Management System (CMMS), a centralized maintenance operations database that facilitates work order procedures and staff directives, can help individual school campuses and school districts to manage maintenance. Presents the benefits of CMMS and things to consider in CMMS selection. (EV)

Building a QC Database of Meteorological Data from NASA KSC and the United States Air Force's Eastern Range

NASA Technical Reports Server (NTRS)

Brenton, J. C.; Barbre, R. E.; Decker, R. K.; Orcutt, J. M.

2018-01-01

The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) Natural Environments Branch (EV44) provides atmospheric databases and analysis in support of space vehicle design and day-of-launch operations for NASA and commercial launch vehicle programs launching from the NASA Kennedy Space Center (KSC), co-located on the United States Air Force's Eastern Range (ER) at the Cape Canaveral Air Force Station. The ER complex is one of the most heavily instrumented sites in the United States with over 31 towers measuring various atmospheric parameters on a continuous basis. An inherent challenge with large datasets consists of ensuring erroneous data are removed from databases, and thus excluded from launch vehicle design analyses. EV44 has put forth great effort in developing quality control (QC) procedures for individual meteorological instruments, however no standard QC procedures for all databases currently exists resulting in QC databases that have inconsistencies in variables, development methodologies, and periods of record. The goal of this activity is to use the previous efforts to develop a standardized set of QC procedures from which to build meteorological databases from KSC and the ER, while maintaining open communication with end users from the launch community to develop ways to improve, adapt and grow the QC database. Details of the QC procedures will be described. As the rate of launches increases with additional launch vehicle programs, It is becoming more important that weather databases are continually updated and checked for data quality before use in launch vehicle design and certification analyses.

Anti-site defected MoS2 sheet for catalytic application

NASA Astrophysics Data System (ADS)

Sharma, Archana; Husain, Mushahid; Khan, Mohd. Shahid

2018-04-01

To prevent harmful and poisonous CO gas molecules, catalysts are needed for converting them into benign substances. Density functional theory (DFT) calculations have been used to investigate CO oxidation on the surface of MoS2 monolayer with Mo atom embedded at S-vacancy site (anti-site defect). The stronger interaction between Mo metal with O2 molecule as compared with CO molecule suggests high catalytic activity. The complete oxidation of CO is studied in a two-step procedure using Langmuir-Hinshelwood (LH) and Eley-Rideal (ER) mechanisms with a low overall energy barrier of 0.35 eV. Creation of anti-site defect makes the surface of MoS2 nanosheet catalytically active for the CO oxidation to take place.

Light-Independent Ionic Transport in Inorganic Perovskite and Ultrastable Cs-Based Perovskite Solar Cells.

PubMed

Zhou, Wenke; Zhao, Yicheng; Zhou, Xu; Fu, Rui; Li, Qi; Zhao, Yao; Liu, Kaihui; Yu, Dapeng; Zhao, Qing

2017-09-07

Due to light-induced effects in CH 3 NH 3 -based perovskites, such as ion migration, defects formation, and halide segregation, the degradation of CH 3 NH 3 -based perovskite solar cells under maximum power point is generally implicated. Here we demonstrated that the effect of light-enhanced ion migration in CH 3 NH 3 PbI 3 can be eliminated by inorganic Cs substitution, leading to an ultrastable perovskite solar cell. Quantitatively, the ion migration barrier for CH 3 NH 3 PbI 3 is 0.62 eV under dark conditions, larger than that of CsPbI 2 Br (0.45 eV); however, it reduces to 0.07 eV for CH 3 NH 3 PbI 3 under illumination, smaller than that for CsPbI 2 Br (0.43 eV). Meanwhile, photoinduced halide segregation is also suppressed in Cs-based perovskites. Cs-based perovskite solar cells retained >99% of the initial efficiency (10.3%) after 1500 h of maximum power point tracking under AM1.5G illumination, while CH 3 NH 3 PbI 3 solar cells degraded severely after 50 h of operation. Our work reveals an uncovered mechanism for stability improvement by inorganic cation substitution in perovskite-based optoelectronic devices.

The BepiColombo Serena/ELENA instrument: performances and testing

NASA Astrophysics Data System (ADS)

Orsini, Stefano; De Angelis, Elisabetta; Selci, Stefano; Di Lellis, Andrea; Leoni, Roberto; Rispoli, Rosanna; Colasanti, Luca; Vertolli, Nello; Mura, Alessandro; Milillo, Anna; D'Alessandro, Marco; Mattioli, Francesco; Maschietti, Daniele; Brienza, Daniele; Scheer, Juergen; Wurz, Peter

2013-04-01

The neutral sensor ELENA (Emitted Low-Energy Neutral Atoms) for the ESA cornerstone BepiColombo mission to Mercury (in the SERENA instrument package) is a new kind of low energetic neutral atoms instrument, mostly devoted to sputtering emission from planetary surfaces, from E ~20 eV up to E~5 keV, within 1-D (4.5°x76°). ELENA is a Time of Flight instrument, based on the novel concept of ultra-sonic oscillating shutter as Start section and MCP detector with 32 discrete anodes as a direct Stop section. ELENA will monitor the emission of neutral atoms from the whole surface of Mercury allowing to investigate the interaction between the environment and the planet, the global particle loss-rate and the remote sensing of the surface properties. In particular, surface release processes are investigated by identifying particles release from the surface via solar wind-induced ion sputtering (<1eV - >100 eV) as well as Hydrogen back-scattered at hundreds eV. The results of ELENA performance test, will be presented: the innovative Shutter system (Start section) operating at requested frequencies (around 43kHz), the ion rejection capability of double deflection system, the Stop detector, the electronic boards, the validation test.

Electric vehicles

NASA Astrophysics Data System (ADS)

1990-03-01

Quiet, clean, and efficient, electric vehicles (EVs) may someday become a practical mode of transportation for the general public. Electric vehicles can provide many advantages for the nation's environment and energy supply because they run on electricity, which can be produced from many sources of energy such as coal, natural gas, uranium, and hydropower. These vehicles offer fuel versatility to the transportation sector, which depends almost solely on oil for its energy needs. Electric vehicles are any mode of transportation operated by a motor that receives electricity from a battery or fuel cell. EVs come in all shapes and sizes and may be used for different tasks. Some EVs are small and simple, such as golf carts and electric wheel chairs. Others are larger and more complex, such as automobile and vans. Some EVs, such as fork lifts, are used in industries. In this fact sheet, we will discuss mostly automobiles and vans. There are also variations on electric vehicles, such as hybrid vehicles and solar-powered vehicles. Hybrid vehicles use electricity as their primary source of energy, however, they also use a backup source of energy, such as gasoline, methanol or ethanol. Solar-powered vehicles are electric vehicles that use photovoltaic cells (cells that convert solar energy to electricity) rather than utility-supplied electricity to recharge the batteries. These concepts are discussed.

Mechanism and kinetics of the electrocatalytic reaction responsible for the high cost of hydrogen fuel cells.

PubMed

Cheng, Tao; Goddard, William A; An, Qi; Xiao, Hai; Merinov, Boris; Morozov, Sergey

2017-01-25

The sluggish oxygen reduction reaction (ORR) is a major impediment to the economic use of hydrogen fuel cells in transportation. In this work, we report the full ORR reaction mechanism for Pt(111) based on Quantum Mechanics (QM) based Reactive metadynamics (RμD) simulations including explicit water to obtain free energy reaction barriers at 298 K. The lowest energy pathway for 4 e - water formation is: first, *OOH formation; second, *OOH reduction to H 2 O and O*; third, O* hydrolysis using surface water to produce two *OH and finally *OH hydration to water. Water formation is the rate-determining step (RDS) for potentials above 0.87 Volt, the normal operating range. Considering the Eley-Rideal (ER) mechanism involving protons from the solvent, we predict the free energy reaction barrier at 298 K for water formation to be 0.25 eV for an external potential below U = 0.87 V and 0.41 eV at U = 1.23 V, in good agreement with experimental values of 0.22 eV and 0.44 eV, respectively. With the mechanism now fully understood, we can use this now validated methodology to examine the changes upon alloying and surface modifications to increase the rate by reducing the barrier for water formation.

Dynamic Optoelectronic Properties in Perovskite Oxide Thin Films Measured with Ultrafast Transient Absorption & Reflectance Spectroscopy

NASA Astrophysics Data System (ADS)

Smolin, Sergey Y.

Ultrafast transient absorption and reflectance spectroscopy are foundational techniques for studying photoexcited carrier recombination mechanisms, lifetimes, and charge transfer rates. Because quantifying photoexcited carrier dynamics is central to the intelligent design and improvement of many solid state devices, these transient optical techniques have been applied to a wide range of semiconductors. However, despite their promise, interpretation of transient absorption and reflectance data is not always straightforward and often relies on assumptions of physical processes, especially with respect to the influence of heating. Studying the material space of perovskite oxides, the careful collection, interpretation, and analysis of ultrafast data is presented here as a guide for future research into novel semiconductors. Perovskite oxides are a class of transition metal oxides with the chemical structure ABO3. Although traditionally studied for their diverse physical, electronic, and magnetic properties, perovskite oxides have gained recent research attention as novel candidates for light harvesting applications. Indeed, strong tunable absorption, unique interfacial properties, and vast chemical flexibility make perovskite oxides a promising photoactive material system. However, there is limited research characterizing dynamic optoelectronic properties, such as recombination lifetimes, which are critical to know in the design of any light-harvesting device. In this thesis, ultrafast transient absorption and reflectance spectroscopy was used to understand these dynamic optoelectronic properties in highquality, thin (<50 nm) perovskite oxide films grown by molecular beam epitaxy. Starting with epitaxial LaFeO3 (LFO) grown on (LaAlO 3)0.3(Sr2AlTaO6)0.7 (LSAT), transient absorption spectroscopy reveals two photoinduced absorption features at the band gap of LFO at 2.4 eV and at the higher energy absorption edge at 3.5 eV. Using a combination of temperature-dependent, variable-angle spectroscopic ellipsometry and time-resolved ultrafast optical spectroscopy on a type I heterostructure, we clarify thermal and electronic contributions to spectral transients in LaFeO3. Upon comparison to thermally-derived static spectra of LaFeO3, we find that thermal contributions dominate the transient absorption and reflectance spectra above the band gap. A transient photoinduced absorption feature below the band gap at 1.9 eV is not reproduced in the thermally derived spectra and has significantly longer decay kinetics from the thermallyinduced features; therefore, this long lived photoinduced absorption is likely derived, at least partially, from photoexcited carriers with lifetimes much longer than 3 nanoseconds. LaFeO3 has a wide band gap of 2.4 eV but its absorption can be decreased with chemical substitution of Sr for Fe to make it more suitable for various applications. This type of A-site substitution is a common route to change static optical absorption in perovskite oxides, but there are no systematic studies looking at how A-site substitution changes dynamic optoelectronic properties. To understand the relationship between composition and static and dynamic optical properties we worked with the model system of La1-xSrxFeO 3-delta epitaxial films grown on LSAT, uncovering the effects of A-site cation substitution and oxygen stoichiometry. Variable-angle spectroscopic ellipsometry was used to measure static optical properties, revealing a linear increase in absorption coefficient at 1.25 eV and a red-shifting of the optical absorption edge with increasing Sr fraction. The absorption spectra can be similarly tuned through the introduction of oxygen vacancies, indicating the critical role that nominal Fe valence plays in optical absorption. Dynamic optoelectronic properties were studied with ultrafast transient reflectance spectroscopy with broadband visible (1.6 eV to 4 eV) and near-infrared (0.9 eV to 1.5 eV) probes. The sign of the reflectance change in the near-infrared region in LSFO is indicative of carrier bandfilling of newly created electronic states by photoexcited carriers. Moreover, we find that similar transient spectral trends can be induced with A-site substitution or through oxygen vacancies, which is a surprising result. Probing the near-infrared region reveals similar nanosecond (1-3 ns) photoexcited carrier lifetimes for oxygen deficient and stoichiometric films. These results demonstrate that while the static optical absorption is strongly dependent on nominal Fe valence tuned through cation or anion stoichiometry, oxygen vacancies do not appear to play a significantly detrimental role in long lived recombination kinetics. Although this thesis represents one of the first comprehensive studies using broad band transient absorption and reflectance spectroscopy to study dynamic optoelectronic phenomena in perovskite oxides, it can also serve as a guide for the implementation and interpretation of ultrafast spectroscopy in other material systems. Moreover, the ultrafast work on perovskite oxides indicates that these materials have long nanosecond lifetimes required for light harvesting devices and should be investigated further.

Lateral and Time Distributions of Extensive Air Showers for CHICOS

NASA Astrophysics Data System (ADS)

Jillings, C. J.; Wells, D.; Chan, K. C.; Hill, J.; Falkowski, B.; Sepikas, J.

2005-04-01

We report results of a series of detailed Monte-Carlo calculations to determine the density and arrival-time distribution of charged particles in extensive air showers. We have parameterized both distributions as a function of distance from the shower axis, energy of the primary cosmic-ray proton, and incident zenith angle. Muons and electrons are parameterized separately. These parameterizations can be easily used in maximum-likelihood reconstruction of air showers. Calculations were performed for primary energies between 10^18 and 10^21eV and zenith angles out to approximately 50^o. The calculations are appropriate for the California High School Cosmic Ray Observatory: a 400 km^2 array of scintillation detectors in Los Angeles county. The average elevation of the array is approximately 250 meters above sea level. Currently 64 of 90 sites are operational. The array will be completed this year. We thank the NSF, the CURE program at the Jet Propulsion Laboratory, the SURF program at Caltech, and the Chinese University of Hong Kong.

Recent Results from KASCADE-Grande and LOPES

NASA Astrophysics Data System (ADS)

Kascade-Grande; Lopes Collaboration; Kampert, K.-H.; Apel, W. D.; Arteaga, J. C.; Asch, T.; Badea, F.; Bähren, L.; Bekk, K.; Bertaina, M.; Biermann, P. L.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Buitink, S.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Ender, M.; Engel, R.; Engler, J.; Falcke, H.; Finger, M.; Fuhrmann, D.; Gemmeke, H.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Horneffer, A.; Huege, T.; Isar, P. G.; Kang, D.; Kickelbick, D.; Klages, H. O.; Kolotaev, Y.; Krömer, O.; Kuijpers, J.; Lafebre, S.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Melissas, M.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Nigl, A.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rautenberg, J.; Rebel, H.; Roth, M.; Saftoiu, A.; Schieler, H.; Schmidt, A.; Schröder, F.; Sima, O.; Singh, K.; Stümpert, M.; Toma, G.; Trinchero, G.; Ulrich, H.; Walkowiak, W.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.; Zensus, J. A.; KASCADE-Grande and LOPES Collaboration

2009-05-01

KASCADE-Grande is an extensive air-shower experiment located at Forschungszentrum Karlsruhe, Germany. Main parts of the experiment are the Grande array spread over an area of 700×700 m, the original KASCADE array covering 200×200 m with unshielded and shielded detectors, and additional muon tracking devices. This multi-detector system allows to investigate the energy spectrum, composition, and anisotropies of cosmic rays in the energy range up to 1 EeV. LOPES is co-located at the same site to measure radio pulses from extensive air showers in coincidence with KASCADE-Grande. It consists of 30 digital antennas operated in different geometrical configurations. Read out is performed at high bandwidths and rate data processing with the aim to calibrate the emitted signal in the primary energy range of 10-10 eV by making use of reconstructed air-shower observables of KASCADE-Grande. An overview on the performance of both experiments will be given and recent analysis results be reported.

The ARIANNA Hexagonal Radio Array - performance and prospects

NASA Astrophysics Data System (ADS)

Hallgren, Allan

2016-04-01

The origin of the highest energy cosmic rays at ˜1020 eV is still unknown. Ultra-high energy neutrinos from the GZK process should provide information on the sources and their properties. A promising and cost effective method for observing GZK-neutrinos is based on detection of Askaryan radio pulses with antennas installed in ice. The ARIANNA project aims at instrumenting a 36*36 km2 large area on the Ross Ice Shelf with an array of radio detection stations. The deployment of a test system for ARIANNA, the Hexagonal Radio Array (HRA), was completed in December 2014. The three first stations were installed in 2012. Solar panels are used to drive the < 10 W stations. The system hibernated at sunset in April and all stations returned to operation in September. The site is essentially free of anthropogenic noise. Simple cuts eliminate background and provides for efficient selection of neutrino events. Prospects for the sensitivity of the full ARIANNA array to the flux of GZK neutrinos are shown.

Defect states in hexagonal boron nitride: Assignments of observed properties and prediction of properties relevant to quantum computation

NASA Astrophysics Data System (ADS)

Sajid, A.; Reimers, Jeffrey R.; Ford, Michael J.

2018-02-01

Key properties of nine possible defect sites in hexagonal boron nitride (h-BN), VN,VN -1,CN,VNO2 B,VNNB,VNCB,VBCN,VBCNS iN , and VNCBS iB , are predicted using density-functional theory and are corrected by applying results from high-level ab initio calculations. Observed h-BN electron-paramagnetic resonance signals at 22.4, 20.83, and 352.70 MHz are assigned to VN,CN, and VNO2 B , respectively, while the observed photoemission at 1.95 eV is assigned to VNCB . Detailed consideration of the available excited states, allowed spin-orbit couplings, zero-field splitting, and optical transitions is made for the two related defects VNCB and VBCN . VNCB is proposed for realizing long-lived quantum memory in h-BN. VBCN is predicted to have a triplet ground state, implying that spin initialization by optical means is feasible and suitable optical excitations are identified, making this defect of interest for possible quantum-qubit operations.

Benchmarking Helps Measure Union Programs, Operations.

ERIC Educational Resources Information Center

Mann, Jerry

2001-01-01

Explores three examples of benchmarking by college student unions. Focuses on how a union can collect information from other unions for use as benchmarking standards for the purposes of selling a concept or justifying program increases, or for comparing a union's financial performance to other unions. (EV)

Absence of Resources. 32nd Annual M & O Cost Study.

ERIC Educational Resources Information Center

Agron, Joe

2003-01-01

An annual survey of school maintenance and operations (M & O) funding concludes, among other detailed findings, that budgets continue to shrink in the face of a weak economy--the sixth year of dropping budgets and the smallest level since the survey began. (EV)

Impeding Sustainability? The Ecological Footprint of Higher Education.

ERIC Educational Resources Information Center

Rees, William E.

2003-01-01

Asserts that universities must strive to reduce the ecological footprints of both their own operations and, more importantly, of the growth-oriented materialistic worldview they promote. Suggests that the real challenge for higher education is to help articulate an alternative life-sustaining worldview. (EV)

Injection of a coaxial-gun-produced magnetized plasma into a background helicon plasma

NASA Astrophysics Data System (ADS)

Zhang, Yue; Lynn, Alan; Gilmore, Mark; Hsu, Scott

2014-10-01

A compact coaxial plasma gun is employed for experimental investigation of plasma bubble relaxation into a lower density background plasma. Experiments are being conducted in the linear device HelCat at UNM. The gun is powered by a 120-uF ignitron-switched capacitor bank, which is operated in a range of 5 to 10 kV and 100 kA. Multiple diagnostics are employed to investigate the plasma relaxation process. Magnetized argon plasma bubbles with velocities 1.2Cs, densities 1020 m-3 and electron temperature 13eV have been achieved. The background helicon plasma has density 1013 m-3, magnetic field from 200 to 500 Gauss and electron temperature 1eV. Several distinct operational regimes with qualitatively different dynamics are identified by fast CCD camera images. Additionally a B-dot probe array has been employed to measure the spatial toroidal and poloidal magnetic flux evolution to identify plasma bubble configurations. Experimental data and analysis will be presented.

Hot ion plasma production in HIP-1 using water-cooled hollow cathodes

NASA Technical Reports Server (NTRS)

Reinmann, J. J.; Lauver, M. R.; Patch, R. W.; Layman, R. W.; Snyder, A.

1975-01-01

The paper reports on hot-ion plasma experiments conducted in a magnetic mirror facility. A steady-state E x B plasma was formed by applying a strong radially inward dc electric field near the mirror throats. Most of the results were for hydrogen, but deuterium and helium plasmas were also studied. Three water-cooled hollow cathodes were operated in the hot-ion plasma mode with the following results: (1) thermally emitting cathodes were not required to achieve the hot-ion mode; (2) steady-state operation (several minutes) was attained; (3) input powers greater than 40 kW were achieved; (4) cathode outside diameters were increased from 1.2 cm (uncooled) to 4.4 cm (water-cooled); (5) steady-state hydrogen plasmas with ion temperatures from 185 to 770 eV and electron temperatures from 5 to 21 eV were produced. Scaling relations were empirically obtained for discharge current, ion temperature, electron temperature, and relative ion density as a function of hydrogen gas feed rate, magnetic field, and cathode voltage.

First Evidence for the Presence of Iron Oxidizing Zetaproteobacteria at the Levantine Continental Margins

PubMed Central

Rubin-Blum, Maxim; Antler, Gilad; Tsadok, Rami; Shemesh, Eli; Austin, James A.; Coleman, Dwight F.; Goodman-Tchernov, Beverly N.; Ben-Avraham, Zvi; Tchernov, Dan

2014-01-01

During the 2010–2011 E/V Nautilus exploration of the Levantine basin’s sediments at the depth of 300–1300 m, densely patched orange-yellow flocculent mats were observed at various locations along the continental margin of Israel. Cores from the mat and the control locations were collected by remotely operated vehicle system (ROV) operated by the E/V Nautilus team. Microscopic observation and phylogenetic analysis of microbial 16S and 23S rRNA gene sequences indicated the presence of zetaproteobacterial stalk forming Mariprofundus spp. – like prokaryotes in the mats. Bacterial tag-encoded FLX amplicon pyrosequencing determined that zetaproteobacterial populations were a dominant fraction of microbial community in the biofilm. We show for the first time that zetaproteobacterial may thrive at the continental margins, regardless of crustal iron supply, indicating significant fluxes of ferrous iron to the sediment-water interface. In light of this discovery, we discuss the potential bioavailability of sediment-water interface iron for organisms in the overlying water column. PMID:24614177

Extracellular Vesicles in Bile as Markers of Malignant Biliary Stenoses.

PubMed

Severino, Valeria; Dumonceau, Jean-Marc; Delhaye, Myriam; Moll, Solange; Annessi-Ramseyer, Isabelle; Robin, Xavier; Frossard, Jean-Louis; Farina, Annarita

2017-08-01

Algorithms for diagnosis of malignant common bile duct (CBD) stenoses are complex and lack accuracy. Malignant tumors secrete large numbers of extracellular vesicles (EVs) into surrounding fluids; EVs might therefore serve as biomarkers for diagnosis. We investigated whether concentrations of EVs in bile could discriminate malignant from nonmalignant CBD stenoses. We collected bile and blood samples from 50 patients undergoing therapeutic endoscopic retrograde cholangiopancreatography at university hospitals in Europe for CBD stenosis of malignant (pancreatic cancer, n = 20 or cholangiocarcinoma, n = 5) or nonmalignant (chronic pancreatitis [CP], n = 15) origin. Ten patients with CBD obstruction due to biliary stones were included as controls. EV concentrations in samples were determined by nanoparticle tracking analyses. The discovery cohort comprised the first 10 patients with a diagnosis of pancreatic cancer, based on tissue analysis, and 10 consecutive controls. Using samples from these subjects, we identified a threshold concentration of bile EVs that could best discriminate between patients with pancreatic cancer from controls. We verified the diagnostic performance of bile EV concentration by analyzing samples from the 30 consecutive patients with a diagnosis of malignant (pancreatic cancer or cholangiocarcinoma, n = 15) or nonmalignant (CP, n = 15) CBD stenosis. Samples were compared using the Mann-Whitney test and nonparametric Spearman correlation analysis. Receiver operating characteristic area under the curve was used to determine diagnostic accuracy. In both cohorts, the median concentration of EVs was significantly higher in bile samples from patients with malignant CBD stenoses than controls or nonmalignant CBD stenoses (2.41 × 10 15 vs 1.60 × 10 14 nanoparticles/L in the discovery cohort; P < .0001 and 4.00 × 10 15 vs 1.26 × 10 14 nanoparticles/L in the verification cohort; P < .0001). A threshold of 9.46 × 10 14 nanoparticles/L in bile best distinguished patients with malignant CBD from controls in the discovery cohort. In the verification cohort, this threshold discriminated malignant from nonmalignant CBD stenoses with 100% accuracy. Serum concentration of EVs distinguished patients with malignant vs patients with nonmalignant CBD stenoses with 63.3% diagnostic accuracy. Concentration of EVs in bile samples discriminates between patients with malignant vs nonmalignant CBD stenosis with 100% accuracy. Further studies are needed to confirm these findings. Clinical Trial registration no: ISRCTN66835592. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Nature of the Active Sites for CO Reduction on Copper Nanoparticles; Suggestions for Optimizing Performance.

PubMed

Cheng, Tao; Xiao, Hai; Goddard, William A

2017-08-30

Recent experiments show that the grain boundaries (GBs) of copper nanoparticles (NPs) lead to an outstanding performance in reducing CO 2 and CO to alcohol products. We report here multiscale simulations that simulate experimental synthesis conditions to predict the structure of a 10 nm Cu NP (158 555 atoms). To identify active sites, we first predict the CO binding at a large number of sites and select four exhibiting CO binding stronger than the (211) step surface. Then, we predict the formation energy of the *OCCOH intermediate as a descriptor for C-C coupling, identifying two active sites, both of which have an under-coordinated surface square site adjacent to a subsurface stacking fault. We then propose a periodic Cu surface (4 by 4 supercell) with a similar site that substantially decreases the formation energy of *OCCOH, by 0.14 eV.

Adsorption and ring-opening of lactide on the chiral metal surface Pt(321)S studied by density functional theory

NASA Astrophysics Data System (ADS)

Franke, J.-H.; Kosov, D. S.

2015-01-01

We study the adsorption and ring-opening of lactide on the naturally chiral metal surface Pt(321)S. Lactide is a precursor for polylactic acid ring-opening polymerization, and Pt is a well known catalyst surface. We study, here, the energetics of the ring-opening of lactide on a surface that has a high density of kink atoms. These sites are expected to be present on a realistic Pt surface and show enhanced catalytic activity. The use of a naturally chiral surface also enables us to study potential chiral selectivity effects of the reaction at the same time. Using density functional theory with a functional that includes the van der Waals forces in a first-principles manner, we find modest adsorption energies of around 1.4 eV for the pristine molecule and different ring-opened states. The energy barrier to be overcome in the ring-opening reaction is found to be very small at 0.32 eV and 0.30 eV for LL- and its chiral partner DD-lactide, respectively. These energies are much smaller than the activation energy for a dehydrogenation reaction of 0.78 eV. Our results thus indicate that (a) ring-opening reactions of lactide on Pt(321) can be expected already at very low temperatures, and Pt might be a very effective catalyst for this reaction; (b) the ring-opening reaction rate shows noticeable enantioselectivity.

First-Principles Modeling of Polaron Formation in TiO2 Polymorphs.

PubMed

Elmaslmane, A R; Watkins, M B; McKenna, K P

2018-06-21

We present a computationally efficient and predictive methodology for modeling the formation and properties of electron and hole polarons in solids. Through a nonempirical and self-consistent optimization of the fraction of Hartree-Fock exchange (α) in a hybrid functional, we ensure the generalized Koopmans' condition is satisfied and self-interaction error is minimized. The approach is applied to model polaron formation in known stable and metastable phases of TiO 2 including anatase, rutile, brookite, TiO 2 (H), TiO 2 (R), and TiO 2 (B). Electron polarons are predicted to form in rutile, TiO 2 (H), and TiO 2 (R) (with trapping energies ranging from -0.02 eV to -0.35 eV). In rutile the electron localizes on a single Ti ion, whereas in TiO 2 (H) and TiO 2 (R) the electron is distributed across two neighboring Ti sites. Hole polarons are predicted to form in anatase, brookite, TiO 2 (H), TiO 2 (R), and TiO 2 (B) (with trapping energies ranging from -0.16 eV to -0.52 eV). In anatase, brookite, and TiO 2 (B) holes localize on a single O ion, whereas in TiO 2 (H) and TiO 2 (R) holes can also be distributed across two O sites. We find that the optimized α has a degree of transferability across the phases, with α = 0.115 describing all phases well. We also note the approach yields accurate band gaps, with anatase, rutile, and brookite within six percent of experimental values. We conclude our study with a comparison of the alignment of polaron charge transition levels across the different phases. Since the approach we describe is only two to three times more expensive than a standard density functional theory calculation, it is ideally suited to model charge trapping at complex defects (such as surfaces and interfaces) in a range of materials relevant for technological applications but previously inaccessible to predictive modeling.

An operational analysis of the Hampton Roads hurricane evacuation traffic control plan.

DOT National Transportation Integrated Search

2006-01-01

The Hampton Roads region of Virginia has developed a hurricane evacuation plan to facilitate the movement of large numbers of vehicles as they attempt to leave the region in advance of a storm. Although the plan considers many aspects of hurricane ev...

Role of driver hearing in commercial motor vehicle operation : an evaluation of the FHWA hearing requirement

DOT National Transportation Integrated Search

1998-11-01

The Federal Highway Administration (FHWA) currently requires that all commercial motor vehicle (CMV) drivers have a specified minimum level of hearing to drive in interstate commerce. This tech brief summarizes an FHWA study of the same title that ev...

Implementing a Capital Plan.

ERIC Educational Resources Information Center

Daigneau, William A.

2003-01-01

Addresses four questions regarding implementation of a long-term capital plan to manage a college's facilities portfolio: When should the projects be implemented? How should the capital improvements be implemented? What will it actually cost in terms of project costs as well as operating costs? Who will implement the plan? (EV)

Large local disorder in superconducting K(0.8)Fe(1.6)Se2 studied by extended x-ray absorption fine structure.

PubMed

Iadecola, A; Joseph, B; Simonelli, L; Puri, A; Mizuguchi, Y; Takeya, H; Takano, Y; Saini, N L

2012-03-21

We have measured the local structure of superconducting K(0.8)Fe(1.6)Se(2) chalcogenide (T(c) = 31.8 K) by temperature dependent polarized extended x-ray absorption fine structure (EXAFS) at the Fe and Se K-edges. We find that the system is characterized by a large local disorder. The Fe-Se and Fe-Fe distances are found to be shorter than the distances measured by diffraction, while the corresponding mean square relative displacements reveal large Fe-site disorder and relatively large c-axis disorder. The local force constant for the Fe-Se bondlength (k ~ 5.8 eV Å(-2)) is similar to the one found in the binary FeSe superconductor, however, the Fe-Fe bondlength appears to be flexible (k ~ 2.1 eV Å(-2)) in comparison to the binary FeSe (k ~ 3.5 eV Å(-2)), an indication of partly relaxed Fe-Fe networks in K(0.8)Fe(1.6)Se(2). The results suggest a glassy nature for the title system, with the superconductivity being similar to that in the granular materials. © 2012 IOP Publishing Ltd

Structure and properties of Mn4Cl9: an antiferromagnetic binary hyperhalogen.

PubMed

Li, Yawei; Zhang, Shunhong; Wang, Qian; Jena, Puru

2013-02-07

Calculations based on density functional theory show that the structure of Mn(4)Cl(9) anion is that of a Mn atom at the core surrounded by three MnCl(3) moieties. Since Mn is predominantly divalent and MnCl(3) is known to be a superhalogen with a vertical detachment energy (VDE) of 5.27 eV, Mn(4)Cl(9) can be viewed as a hyperhalogen with the formula unit Mn(MnCl(3))(3). Indeed, the calculated VDE of Mn(4)Cl(9) anion, namely 6.76 eV, is larger than that of MnCl(3) anion. More importantly, unlike previously discovered hyperhalogens, Mn(4)Cl(9) is the first such hyperhalogen species composed of only two constituent atoms. We further show that Mn(4)Cl(9) can be used as a ligand to design molecules with even higher VDEs. For example, Li[Mn(MnCl(3))(3)](2) anion has a VDE of 7.26 eV. These negatively charged clusters are antiferromagnetic with most of the magnetic moments localized at the Mn sites. Our studies show new pathways for creating binary hyperhalogens.

Structure and properties of Mn4Cl9: An antiferromagnetic binary hyperhalogen

NASA Astrophysics Data System (ADS)

Li, Yawei; Zhang, Shunhong; Wang, Qian; Jena, Puru

2013-02-01

Calculations based on density functional theory show that the structure of Mn4Cl9 anion is that of a Mn atom at the core surrounded by three MnCl3 moieties. Since Mn is predominantly divalent and MnCl3 is known to be a superhalogen with a vertical detachment energy (VDE) of 5.27 eV, Mn4Cl9 can be viewed as a hyperhalogen with the formula unit Mn(MnCl3)3. Indeed, the calculated VDE of Mn4Cl9 anion, namely 6.76 eV, is larger than that of MnCl3 anion. More importantly, unlike previously discovered hyperhalogens, Mn4Cl9 is the first such hyperhalogen species composed of only two constituent atoms. We further show that Mn4Cl9 can be used as a ligand to design molecules with even higher VDEs. For example, Li[Mn(MnCl3)3]2 anion has a VDE of 7.26 eV. These negatively charged clusters are antiferromagnetic with most of the magnetic moments localized at the Mn sites. Our studies show new pathways for creating binary hyperhalogens.

78 FR 57845 - Notice of Public Meetings for the Draft Supplemental Environmental Impact Statement for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-20

... submitted via the U.S. Postal Service to Naval Facilities Engineering Command Atlantic, Attn: Code EV21/CZ... via the project Web site ( http://www.mmaseis.com ). All statements submitted during the public review... in writing at the public meetings, via the U.S. Postal Service, or electronically via the public Web...

Interplay of Coordination Environment and Magnetic Behavior of Layered Co(II) Hydroxichlorides: A DFT+U Study.

PubMed

Hunt, Diego; Jobbagy, Matías; Scherlis, Damián A

2018-05-07

In this work we present a systematic computational study of the structural and magnetic properties of a layered family of Co(II) hydroxichlorides, obeying to the general formula Co(OH) 2- x Cl x (H 2 O) y . This solid contains both octahedral and tetrahedral cobalt ions, displaying a complex magnetic order arising from the particular coupling between the two kinds of metallic centers. Here, supercells representing concentrations of 12, 20, and 40% of tetrahedral sites were modeled consistently with the compositions reported experimentally. Our simulations show that the two types of cobalt ions tend to couple antiferromagnetically, giving rise to a net magnetic moment slightly out of the plane of the layers. The band gap reaches its minimum value of 1.4 eV for the most diluted fraction of tetrahedral Co(II) sites, going up to 2.2 eV when the content is 40%. Moreover, our results suggest that the presence of interlayer water stabilizes the material and at the same time strongly modifies the electronic environment of tetrahedral Co(II), leading to a further drop of the band gap. To our knowledge, this is the first theoretical investigation of this material.

Radiative neutron capture as a counting technique at pulsed spallation neutron sources: a review of current progress

NASA Astrophysics Data System (ADS)

Schooneveld, E. M.; Pietropaolo, A.; Andreani, C.; Perelli Cippo, E.; Rhodes, N. J.; Senesi, R.; Tardocchi, M.; Gorini, G.

2016-09-01

Neutron scattering techniques are attracting an increasing interest from scientists in various research fields, ranging from physics and chemistry to biology and archaeometry. The success of these neutron scattering applications is stimulated by the development of higher performance instrumentation. The development of new techniques and concepts, including radiative capture based neutron detection, is therefore a key issue to be addressed. Radiative capture based neutron detectors utilize the emission of prompt gamma rays after neutron absorption in a suitable isotope and the detection of those gammas by a photon counter. They can be used as simple counters in the thermal region and (simultaneously) as energy selector and counters for neutrons in the eV energy region. Several years of extensive development have made eV neutron spectrometers operating in the so-called resonance detector spectrometer (RDS) configuration outperform their conventional counterparts. In fact, the VESUVIO spectrometer, a flagship instrument at ISIS serving a continuous user programme for eV inelastic neutron spectroscopy measurements, is operating in the RDS configuration since 2007. In this review, we discuss the physical mechanism underlying the RDS configuration and the development of associated instrumentation. A few successful neutron scattering experiments that utilize the radiative capture counting techniques will be presented together with the potential of this technique for thermal neutron diffraction measurements. We also outline possible improvements and future perspectives for radiative capture based neutron detectors in neutron scattering application at pulsed neutron sources.

High density processing electronics for superconducting tunnel junction x-ray detector arrays

NASA Astrophysics Data System (ADS)

Warburton, W. K.; Harris, J. T.; Friedrich, S.

2015-06-01

Superconducting tunnel junctions (STJs) are excellent soft x-ray (100-2000 eV) detectors, particularly for synchrotron applications, because of their ability to obtain energy resolutions below 10 eV at count rates approaching 10 kcps. In order to achieve useful solid detection angles with these very small detectors, they are typically deployed in large arrays - currently with 100+ elements, but with 1000 elements being contemplated. In this paper we review a 5-year effort to develop compact, computer controlled low-noise processing electronics for STJ detector arrays, focusing on the major issues encountered and our solutions to them. Of particular interest are our preamplifier design, which can set the STJ operating points under computer control and achieve 2.7 eV energy resolution; our low noise power supply, which produces only 2 nV/√Hz noise at the preamplifier's critical cascode node; our digital processing card that digitizes and digitally processes 32 channels; and an STJ I-V curve scanning algorithm that computes noise as a function of offset voltage, allowing an optimum operating point to be easily selected. With 32 preamplifiers laid out on a custom 3U EuroCard, and the 32 channel digital card in a 3U PXI card format, electronics for a 128 channel array occupy only two small chassis, each the size of a National Instruments 5-slot PXI crate, and allow full array control with simple extensions of existing beam line data collection packages.

Electronic structure, magnetism, and optical properties of Fe2SiO4 fayalite at ambient and high pressures: A GGA+U study

NASA Astrophysics Data System (ADS)

Jiang, Xuefan; Guo, G. Y.

2004-04-01

The electronic structure, magnetism, and optical properties of Fe2SiO4 fayalite, the iron-rich end member of the olivine-type silicate, one of the most abundant minerals in Earth’s upper mantle, have been studied by density-functional theory within the generalized gradient approximation (GGA) with the on-site Coulomb energy U=4.5 eV taken into account (GGA+U). The stable insulating antiferromagnetic solution with an energy gap ˜1.49 eV and a spin magnetic moment of 3.65μB and an orbital magnetic moment of 0.044μB per iron atom is obtained. It is found that the gap opening in this fayalite results mainly from the strong on-site Coulomb interaction on the iron atoms. In this band structure, the top of valence bands consists mainly of the 3d orbitals of Fe2 atoms, and the bottom of the conduction bands is mainly composed of the 3d orbitals of Fe1 atoms. Therefore, since the electronic transition from the Fe2 3d to Fe1 3d states is weak, significant electronic transitions would appear only about 1 eV above the absorption edge when Fe-O orbitals are involved in the final states. In addition, our band-structure calculations can explain the observed phenomena including redshift near the absorption edge and the decrease of the electrical resistivity of Fe2SiO4 upon compression. The calculated Fe p partial density of states agree well with Fe K-edge x-ray absorption spectrum. The calculated lattice constants and atomic coordinates for Fe2SiO4 fayalite in orthorhombic structure are in good agreement with experiments.

Nearly temperature-independent ultraviolet light emission intensity of indirect excitons in hexagonal BN microcrystals

NASA Astrophysics Data System (ADS)

Chichibu, Shigefusa F.; Ishikawa, Youichi; Kominami, Hiroko; Hara, Kazuhiko

2018-02-01

The radiative performance of hexagonal boron nitride (h-BN) was assessed by the spatio-time-resolved luminescence measurements on its microcrystals (MCs) annealed in an O2 gas ambient. The MCs exhibited distinct deep ultraviolet luminescence peaks higher than 5.7 eV, although h-BN is an indirect bandgap semiconductor. The result indicates a strong interaction between the indirect excitons (iXs) and LO/TO (and LA/TA) phonons at T points of the Brillouin zone. Such phonon replicas of free iXs and a luminescence band at 4.0 eV showed negligible thermal quenching, most probably assisted by the strong excitonic effect, enhanced phonon scattering, and formation of a surface BxOy layer that prevents excitons from surface recombination by the thermal excitation. Conversely, the luminescence band between 5.1 and 5.7 eV, which seems to consist of LO/TO phonon replicas of iXs localized at a certain structural singularity that are further scattered by multiple TO phonons at K points and another two emission peaks that originate from the singularity, showed the thermal quenching. In analogy with GaN and AlGaN, cation vacancy complexes most likely act as native nonradiative recombination centers (NRCs). In the present case, vacancy complexes that contain a boron vacancy (VB), such as divacancies with a nitrogen vacancy (VN), VBVN, are certain to act as NRCs. In this instance, iXs delocalized from the singularity are likely either captured by NRCs or the origin of the 4.0 eV-band; the latter is assigned to originate from a carbon on the N site or a complex between VB and an oxygen on the N site.

Steps Towards an Operational Service Using Near Real-Time Altimeter Data

NASA Astrophysics Data System (ADS)

Ash, E. R.

2006-07-01

Thanks largely to modern computing power, numerical forecasts of w inds and waves over the oceans ar e ev er improving, offering greater accuracy and finer resolution in time and sp ace. Howev er, it is recognized that met-ocean models still have difficulty in accurately forecasting sever e w eather conditions, conditions that cause the most damag e and difficulty in mar itime operations. Ther efore a key requir emen t is to provid e improved information on sever e conditions. No individual measur emen t or prediction system is perfect. Offshore buoys provide a continuous long-ter m record of wind and wave conditions, but only at a limited numb er of sites. Satellite data offer all-weath er global cov erage, but with relatively infrequen t samp ling. Forecasts rely on imperf ect numerical schemes and the ab ility to manage a vast quantity of input data. Therefore the best system is one that integr ates information from all available sources, taking advantage of the benef its that each can offer. We report on an initiative supported by the European Space Agen cy (ESA) which investig ated how satellite data could be used to enhan ce systems to provide Near Real Time mon itor ing of met-ocean conditions.

Dialectical Materialism: Analysis of Mental Actions.

ERIC Educational Resources Information Center

Reese, Hayne W.

In the Soviet theory of cognitive development, originated by Vygotsky and elaborated by Leont'ev, acts occur at three levels of abstraction: activities, actions, and operations. According to this theory, an activity has an associated motive and may function directively as a motive. While many activities are possible, one activity tends to…

Cell-Phone Technology Threatens To Devour Distance-Education Bandwidth.

ERIC Educational Resources Information Center

Blumenstyk, Goldie

2001-01-01

Describes educators' fear that a government proposal to help accommodate new Web-surfing cell phones and other hand-held devices could end up displacing instructional-television operations. The proposal could also undermine partnerships that educational broadcasters have begun negotiating with companies to create new speedy Internet services. (EV)

Alternative Fuels Data Center: Hybrid and Plug-In Electric Vehicles

Science.gov Websites

in this section... Electricity Basics Benefits & Considerations Stations Vehicles Availability -electric vehicles (EVs)-also called electric-drive vehicles collectively-use electricity either as their charge the battery. Some can travel more than 70 miles on electricity alone, and all can operate solely

INDOOR-OUTDOOR RELATIONSHIPS OF PARTICLES, PAH, AND BLACK CARBON IN AN OCCUPIED TOWNHOUSE

EPA Science Inventory

Real-time instrumentation for measuring particles, PAH, and black carbon (soot) has been operated since May of 1998 in an occupied 3-story town house in Reston, VA. Indoor and outdoor concentrations have been measured every five minutes for the particles and black carbon and ev...

State Funding of Higher Education: A New Formula.

ERIC Educational Resources Information Center

Edirisooriya, Gunapala

2003-01-01

Asserts that heavy dependence on state support is quite detrimental to operational viability of higher education institutions, and that securing financial stability of higher education institutions should be a major priority among higher education policymakers. Presents a new funding formula that can be adopted by any state. (EV)

Some photophysical properties of new oligomer obtained from anodic oxidation of 4,4‧-dimethoxychalcone

NASA Astrophysics Data System (ADS)

Ghomrasni, S.; Aribi, I.; Chemek, M.; Said, A. Haj; Alimi, K.

2018-04-01

Some photopysical properties of a new oligomer obtained from the anodic oxidation of the 4,4‧-dimethoxy-chalcone were investigated using different and complementary techniques. Firstly, TGA analysis and X-Ray diffraction experiments showed that the oligomer is thermally stable up to 500 K and partially organized at the solid state, respectively. Secondly, the optical properties of the oligomer were studied in solution and in the solid state. The optical band gap was estimated to be 3.17 eV in solution state and 2.70 eV in film state. What's more, the fluorescence decay is determined showing a considerably faster in the film state (0.183 ns) than in solution state (1.606 ns), due to the rapid non-radiative decay at inter-chain trap sites.

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

Jain, Richa Naja, E-mail: ltprichanaja@gmail.com; Chakraborty, Brahmananda; Ramaniah, Lavanya M.

The electronic structure and hydrogen storage capability of Yttrium-doped BNNTs has been theoretically investigated using first principles density functional theory (DFT). Yttrium atom prefers the hollow site in the center of the hexagonal ring with a binding energy of 0.8048eV. Decorating by Y makes the system half-metallic and magnetic with a magnetic moment of 1.0µ{sub B}. Y decorated Boron-Nitride (8,0) nanotube can adsorb up to five hydrogen molecules whose average binding energy is computed as 0.5044eV. All the hydrogen molecules are adsorbed with an average desorption temperature of 644.708 K. Taking that the Y atoms can be placed only in alternatemore » hexagons, the implied wt% comes out to be 5.31%, a relatively acceptable value for hydrogen storage materials. Thus, this system can serve as potential hydrogen storage medium.« less

Low Earth orbital atomic oxygen environmental simulation facility for space materials evaluation

NASA Technical Reports Server (NTRS)

Stidham, Curtis R.; Banks, Bruce A.; Stueber, Thomas J.; Dever, Joyce A.; Rutledge, Sharon K.; Bruckner, Eric J.

1993-01-01

Simulation of low Earth orbit atomic oxygen for accelerated exposure in ground-based facilities is necessary for the durability evaluation of space power system component materials for Space Station Freedom (SSF) and future missions. A facility developed at the National Aeronautics and Space Administrations's (NASA) Lewis Research Center provides accelerated rates of exposure to a directed or scattered oxygen beam, vacuum ultraviolet (VUV) radiation, and offers in-situ optical characterization. The facility utilizes an electron-cyclotron resonance (ECR) plasma source to generate a low energy oxygen beam. Total hemispherical spectral reflectance of samples can be measured in situ over the wavelength range of 250 to 2500 nm. Deuterium lamps provide VUV radiation intensity levels in the 115 to 200 nm range of three to five equivalent suns. Retarding potential analyses show distributed ion energies below 30 electron volts (eV) for the operating conditions most suited for high flux, low energy testing. Peak ion energies are below the sputter threshold energy (approximately 30 eV) of the protective coatings on polymers that are evaluated in the facility, thus allowing long duration exposure without sputter erosion. Neutral species are expected to be at thermal energies of approximately .04 eV to .1 eV. The maximum effective flux level based on polyimide Kapton mass loss is 4.4 x 10 exp 6 atoms/((sq. cm)*s), thus providing a highly accelerated testing capability.

Ion acceleration and non-Maxwellian electron distributions in a low collisionality, high power helicon plasma source

NASA Astrophysics Data System (ADS)

Li, Yan; Sung, Yung-Ta; Scharer, John

2015-11-01

Ion acceleration through plasma double layer and non-Maxwellian two temperature electron distributions have been observed in Madison Helicon Experiment (MadHeX) operated in high RF power (>1000 W) and low Ar pressure (0.17 mtorr) inductive mode. By applying Optical Emission Spectroscopy (OES) cross-checked with an RF-compensated Langmuir probe (at 13.56 MHz and its second and third harmonics), the fast (>80 eV), untrapped electrons downstream of the double layer have a higher temperature of 13 eV than the trapped bulk electrons upstream with a temperature of 4 eV. The reduction of plasma potential and density observed in the double layer region require an upstream temperature ten times the measured 4 eV if occurring via Boltzmann ambipolar expansion. The hot tail electrons of the non-Maxwellian electron distribution affect the formation and the potential drop of the double layer region. The mechanism behind this has been explored via several non-invasive plasma diagnostics tools. The OES measured electron temperatures and densities are also cross-checked with Atomic Data and Analysis Structure (ADAS) and a millimeter wave interferometer respectively. The IEDF is measured by a four-grid RPA and also cross-checked with argon 668 nm Laser Induced Fluorescence (LIF). An emissive probe has been used to measure the plasma potential.

Aluminium X-ray absorption Near Edge Structure in model compounds and Earth's surface minerals

NASA Astrophysics Data System (ADS)

Ildefonse, P.; Cabaret, D.; Sainctavit, P.; Calas, G.; Flank, A.-M.; Lagarde, P.

Aluminium K-edge X-ray absorption near edge spectra (XANES) of a suite of silicate and oxides minerals consist of electronic excitations occurring in the edge region, and multiple scattering resonances at higher energies. The main XANES feature for four-fold Al is at around 2 eV lower energy than the main XANES feature for six-fold Al. This provides a useful probe for coordination numbers in clay minerals, gels, glasses or material with unknown Al-coordination number. Six-fold aluminium yields a large variety of XANES features which can be correlated with octahedral point symmetry, number of aluminium sites and distribution of Al-O distances. These three parameters may act together, and the quantitative interpretation of XANES spectra is difficult. For a low point symmetry (1), variations are mainly related to the number of Al sites and distribution of Al-O distances: pyrophyllite, one Al site, is clearly distinguished from kaolinite and gibbsite presenting two Al sites. For a given number of Al-site (1), variations are controlled by changes in point symmetry, the number of XANES features being increased as point symmetry decreases. For a given point symmetry (1) and a given number of Al site (1), variations are related to second nearest neighbours (gibbsite versus kaolinite). The amplitude of the XANES feature at about 1566 eV is a useful probe for the assessment of AlIV/Altotal ratios in 2/1 phyllosilicates. Al-K XANES has been performed on synthetic Al-bearing goethites which cannot be studied by 27Al NMR. At low Al content, Al-K XANES is very different from that of α-AlOOH but at the highest level, XANES spectrum tends to that of diaspore. Al-K XAS is thus a promising tool for the structural study of poorly ordered materials such as clay minerals and natural alumino-silicate gels together with Al-subsituted Fe-oxyhydroxides.

Development of a 2.0 eV AlGaInP Solar Cell Grown by OMVPE

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

Perl, Emmett E.; Simon, John; Geisz, John F.

2015-06-14

AlGaInP solar cells with a bandgap (Eg) of ~2.0 eV are developed for use in next-generation multijunction photovoltaic devices. This material system is of great interest for both space and concentrator photovoltaics due to its high bandgap, which enables the development of high-efficiency five-junction and six-junction devices and is also useful for solar cells operated at elevated temperatures. In this work, we explore the conditions for the Organometallic Vapor Phase Epitaxy (OMVPE) growth of AlGaInP and study their effects on cell performance. A ~2.0 eV AlGaInP solar cell is demonstrated with an open circuit voltage (VOC) of 1.59V, a bandgap-voltagemore » offset (WOC) of 420mV, a fill factor (FF) of 88.0%, and an efficiency of 14.8%. These AlGaInP cells have attained a similar FF, WOC and internal quantum efficiency (IQE) to the best upright GaInP cells grown in our lab to date.« less

A broadband metamaterial absorber based on multi-layer graphene in the terahertz region

NASA Astrophysics Data System (ADS)

Fu, Pan; Liu, Fei; Ren, Guang Jun; Su, Fei; Li, Dong; Yao, Jian Quan

2018-06-01

A broadband metamaterial absorber, composed of the periodic graphene pattern on SiO2 dielectric with the double layer graphene films inserted in it and all of them backed by metal plan, is proposed and investigated. The simulation results reveal that the wide absorption band can be flexibly tuned between the low-frequency band and the high-frequency band by adjusting graphene's Fermi level. The absorption can achieve 90% in 5.50-7.10 THz, with Fermi level of graphene is 0.3 eV, while in 6.98-9.10 THz with Fermi level 0.6 eV. Furthermore, the proposed structure can be switched from reflection (>81%) to absorption (>90%) over the whole operation band, when the Fermi level of graphene varies from 0 to 0.6 eV. Besides, the proposed absorber is insensitive to the polarization and can work over a wide range of incident angle. Compared with the previous broadband absorber, our graphene based wideband terahertz absorber can enable a wide application of high performance terahertz devices, including sensors, imaging devices and electro-optic switches.

Small RNAs and extracellular vesicles in filarial nematodes: From nematode development to diagnostics.

PubMed

Quintana, J F; Babayan, S A; Buck, A H

2017-02-01

Parasitic nematodes have evolved sophisticated mechanisms to communicate with their hosts in order to survive and successfully establish an infection. The transfer of RNA within extracellular vesicles (EVs) has recently been described as a mechanism that could contribute to this communication in filarial nematodes. It has been shown that these EVs are loaded with several types of RNAs, including microRNAs, leading to the hypothesis that parasites could actively use these molecules to manipulate host gene expression and to the exciting prospect that these pathways could result in new diagnostic and therapeutic strategies. Here, we review the literature on the diverse RNAi pathways that operate in nematodes and more specifically our current knowledge of extracellular RNA (exRNA) and EVs derived from filarial nematodes in vitro and within their hosts. We further detail some of the issues and questions related to the capacity of RNA-mediated communication to function in parasite-host interactions and the ability of exRNA to enable us to distinguish and detect different nematode parasites in their hosts. © 2016 The Authors. Parasite Immunology published by John Wiley & Sons Ltd.

Soft x-ray streak camera for laser fusion applications

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

Stradling, G.L.

This thesis reviews the development and significance of the soft x-ray streak camera (SXRSC) in the context of inertial confinement fusion energy development. A brief introduction of laser fusion and laser fusion diagnostics is presented. The need for a soft x-ray streak camera as a laser fusion diagnostic is shown. Basic x-ray streak camera characteristics, design, and operation are reviewed. The SXRSC design criteria, the requirement for a subkilovolt x-ray transmitting window, and the resulting camera design are explained. Theory and design of reflector-filter pair combinations for three subkilovolt channels centered at 220 eV, 460 eV, and 620 eV aremore » also presented. Calibration experiments are explained and data showing a dynamic range of 1000 and a sweep speed of 134 psec/mm are presented. Sensitivity modifications to the soft x-ray streak camera for a high-power target shot are described. A preliminary investigation, using a stepped cathode, of the thickness dependence of the gold photocathode response is discussed. Data from a typical Argus laser gold-disk target experiment are shown.« less

A high resolution gas scintillation proportional counter for studying low energy cosmic X-ray sources

NASA Technical Reports Server (NTRS)

Hamilton, T. T.; Hailey, C. J.; Ku, W. H.-M.; Novick, R.

1980-01-01

In recent years much effort has been devoted to the development of large area gas scintillation proportional counters (GSPCs) suitable for use in X-ray astronomy. The paper deals with a low-energy GSPC for use in detecting sub-keV X-rays from cosmic sources. This instrument has a measured energy resolution of 85 eV (FWHM) at 149 eV over a sensitive area of 5 sq cm. The development of imaging capability for this instrument is discussed. Tests are performed on the feasibility of using an arrangement of several phototubes placed adjacent to one another to determine event locations in a large flat counter. A simple prototype has been constructed and successfully operated.

Ultraviolet light-absorbing and emitting diodes consisting of a p-type transparent-semiconducting NiO film deposited on an n-type GaN homoepitaxial layer

NASA Astrophysics Data System (ADS)

Nakai, Hiroshi; Sugiyama, Mutsumi; Chichibu, Shigefusa F.

2017-05-01

Gallium nitride (GaN) and related (Al,Ga,In)N alloys provide practical benefits in the production of light-emitting diodes (LEDs) and laser diodes operating in ultraviolet (UV) to green wavelength regions. However, obtaining low resistivity p-type AlN or AlGaN of large bandgap energies (Eg) is a critical issue in fabricating UV and deep UV-LEDs. NiO is a promising candidate for useful p-type transparent-semiconducting films because its Eg is 4.0 eV and it can be doped into p-type conductivity of sufficiently low resistivity. By using these technologies, heterogeneous junction diodes consisting of a p-type transparent-semiconducting polycrystalline NiO film on an n-type single crystalline GaN epilayer on a low threading-dislocation density, free-standing GaN substrate were fabricated. The NiO film was deposited by using the conventional RF-sputtering method, and the GaN homoepitaxial layer was grown by metalorganic vapor phase epitaxy. They exhibited a significant photovoltaic effect under UV light and also exhibited an electroluminescence peak at 3.26 eV under forward-biased conditions. From the conduction and valence band (EV) discontinuities, the NiO/GaN heterointerface is assigned to form a staggered-type (TYPE-II) band alignment with the EV of NiO higher by 2.0 eV than that of GaN. A rectifying property that is consistent with the proposed band diagram was observed in the current-voltage characteristics. These results indicate that polycrystalline NiO functions as a hole-extracting and injecting layer of UV optoelectronic devices.

Spleen Stiffness Is Superior to Liver Stiffness for Predicting Esophageal Varices in Chronic Liver Disease: A Meta-Analysis.

PubMed

Ma, Xiaowen; Wang, Le; Wu, Hao; Feng, Yuemin; Han, Xibiao; Bu, Haoran; Zhu, Qiang

2016-01-01

Liver stiffness (LS) and spleen stiffness (SS) are two most widely accessible non-invasive parameters for predicting esophageal varices (EV), but the reported accuracy of the two predictors have been inconsistent across studies. This meta-analysis aims to evaluate the diagnostic performance of LS and SS measurement for detecting EV in patients with chronic liver disease (CLD), and compare their accuracy. Pubmed/Medline, Embase, Cochrane Library and Ovid were searched for all studies assessing SS and LS simultaneously in EV diagnosis. A total of 16 studies including 1892 patients were included in this meta-analysis, and the pooled statistical parameters were calculated using the bivariate mixed effects models. In detection of any EV, for LS measurement, the summary sensitivity was 0.83 (95% confidence interval [CI]: 0.78-0.87), and the specificity was 0.66 (95% CI: 0.60-0.72). While for SS measurement, the pooled sensitivity and specificity was 0.88 (95% CI: 0.83-0.92) and 0.78 (95% CI: 0.73-0.83). The summary receiver operating characteristic (SROC) curve values of LS and SS were 0.81 (95% CI: 0.77-0.84) and 0.88 (95% CI: 0.85-0.91) respectively, and the results had statistical significance (P<0.01). The diagnostic odds ratio (DOR) of SS (25.73) was significantly higher than that of LS (9.54), with the relative DOR value was 2.48 (95%CI: 1.10-5.60), P<0.05. Under current techniques, SS is significantly superior to LS for identifying the presence of EV in patients with CLD. SS measurement may help to select patients for endoscopic screening.

[Epidemiological characteristics of enterovirus type 71 diseases].

PubMed

Gan, Zhengkai; Li, Jingxin; Meng, Fanyue; Hu, Yuemei; Yao, Xuejun; Zhang, Xuefeng; Zhu, Fengcai

2015-01-01

The objective of this study was to investigate the epidemiological characteristics of disease caused by enterovirus type 71. A total of 10 158 children aged between 6 and 35 months, were recruited from 7 sites where EV71 inactivated vaccine phase 3 clinical trial was carried out. All the subjects were followed up to one year to investigate the epidemiological characteristics of the disease caused by EV71. The accumulate incidence density of disease caused by EV71 was 15.17/1 000 person-year. Of all the cases, hand, foot and mouth disease (HFMD), herpangina, respiratory system diseases, digestive system diseases and other diseases accounted for 82.00%, 2.67%, 13.33%, 1.33% and 0.67%, respectively. The difference of the incidence density between boys and girls showed no statistical significance. Majority of the patients were between 12 and 23 months of age, which accounted for 58.67% of the total patients. The differences of incidence density between different months of age were statistically significant (χ(2) = 7.789, P = 0.020). The peak incidence density of disease caused by EV71 occurred from April to June. Nine cases showed severe symptoms or signs that accounted for 6.00% of all the cases. All severe cases were identified as HFMD, of which 7 were boys and 2 were girls. The number of severe cases in different months of age appeared to be 1, 7, and 1, all occurred between April and June. The median courses of HFMD cases and non-HFMD cases were 9 and 6 days, with difference statistically significant (Z = -4.000, P < 0.001). Median of excretion cycle for HFMD and non-HFMD cases were 9 and 11 days respectively. But with no statistically significant difference between the two. Majority of the disease that caused by EV71 appeared as HFMD. Most of them were younger children and with seasonal variation.

Ag nanoparticle decorated molybdenum oxide structures: growth, characterization, DFT studies and their application to enhanced field emission

NASA Astrophysics Data System (ADS)

Guha, Puspendu; Ghosh, Arnab; Thapa, Ranjit; Mathan Kumar, E.; Kirishwaran, Sabari; Singh, Ranveer; Satyam, Parlapalli V.

2017-10-01

We report a simple single step growth of α-MoO3 structures and energetically suitable site specific Ag nanoparticle (NP) decorated α-MoO3 structures on varied substrates, having almost similar morphologies and oxygen vacancies. We elucidate possible growth mechanisms in light of experimental findings and density functional theory (DFT) calculations. We experimentally establish and verified by DFT calculations that the MoO3(010) surface is a weakly interacting and stable surface compared to other orientations. From DFT study, the binding energy is found to be higher for (100) and (001) surfaces (˜-0.98 eV), compared to the (010) surface (˜-0.15 eV) and thus it is likely that Ag NP formation is not favorable on the MoO3(010) surface. The Ag decorated MoO3 (Ag-MoO3) nanostructured sample shows enhanced field emission properties with an approimately 2.1 times lower turn-on voltage of 1.67 V μm-1 and one order higher field enhancement factor (β) of 8.6 × 104 compared to the MoO3 sample without Ag incorporation. From Kelvin probe force microscopy measurements, the average local work function (Φ) is found to be approximately 0.47 eV smaller for the Ag-MoO3 sample (˜5.70 ± 0.05 eV) compared to the MoO3 sample (˜6.17 ± 0.05 eV) and the reduction in Φ can be attributed to the shifting Fermi level of MoO3 toward vacuum via electron injection from Ag NPs to MoO3. The presence of oxygen vacancies together with Ag NPs lead to the highest β and lowest turn-on field among the reported values under the MoO3 emitter category.

Observation of two distinct negative trions in tungsten disulfide monolayers

NASA Astrophysics Data System (ADS)

Boulesbaa, Abdelaziz; Huang, Bing; Wang, Kai; Lin, Ming-Wei; Mahjouri-Samani, Masoud; Rouleau, Christopher; Xiao, Kai; Yoon, Mina; Sumpter, Bobby; Puretzky, Alexander; Geohegan, David

2015-09-01

Ultrafast pump-probe spectroscopy of two-dimensional tungsten disulfide monolayers (2 D W S2) grown on sapphire substrates revealed two transient absorption spectral peaks that are attributed to distinct negative trions at ˜2.02 eV (T1) and ˜1.98 eV (T2) . The dynamics measurements indicate that trion formation by the probe is enabled by photodoped 2D WS2 crystals with electrons remaining after trapping of holes from excitons or free electron-hole pairs at defect sites in the crystal or on the substrate. Dynamics of the characteristic absorption bands of excitons XA and XB at ˜2.03 and ˜2.40 eV , respectively, were separately monitored and compared to the photoinduced absorption features. Selective excitation of the lowest exciton level XA using λpump<2.4 eV forms only trion T1, implying that the electron remaining from dissociation of exciton XA is involved in the creation of this trion with a binding energy ˜10 meV with respect to XA. The absorption peak corresponding to trion T2 appears when λpump<2.4 eV , which is just sufficient to excite exciton XB. The dynamics of trion T2 formation are found to correlate with the disappearance of the bleach of the XB exciton, indicating the involvement of holes participating in the bleach dynamics of exciton XB. Static electrical-doping photoabsorption measurements confirm the presence of an induced absorption peak similar to that of T2. Since the proposed trion formation process here involves exciton dissociation through hole trapping by defects in the 2D crystal or substrate, this discovery highlights the strong role of defects in defining optical and electrical properties of 2D metal chalcogenides, which is relevant to a broad spectrum of basic science and technological applications.

Characterization of Cancer Stem-Like Cells Derived from Mouse Induced Pluripotent Stem Cells Transformed by Tumor-Derived Extracellular Vesicles

PubMed Central

Yan, Ting; Mizutani, Akifumi; Chen, Ling; Takaki, Mai; Hiramoto, Yuki; Matsuda, Shuichi; Shigehiro, Tsukasa; Kasai, Tomonari; Kudoh, Takayuki; Murakami, Hiroshi; Masuda, Junko; Hendrix, Mary J. C.; Strizzi, Luigi; Salomon, David S.; Fu, Li; Seno, Masaharu

2014-01-01

Several studies have shown that cancer niche can perform an active role in the regulation of tumor cell maintenance and progression through extracellular vesicles-based intercellular communication. However, it has not been reported whether this vesicle-mediated communication affects the malignant transformation of normal stem cells/progenitors. We have previously reported that the conditioned medium derived from the mouse Lewis Lung Carcinoma (LLC) cell line can convert mouse induced pluripotent stem cells (miPSCs) into cancer stem cells (CSCs), indicating that normal stem cells when placed in an aberrant microenvironment can give rise to functionally active CSCs. Here, we focused on the contribution of tumor-derived extracellular vesicles (tEVs) that are secreted from LLC cells to induce the transformation of miPSCs into CSCs. We isolated tEVs from the conditioned medium of LLC cells, and then the differentiating miPSCs were exposed to tEVs for 4 weeks. The resultant tEV treated cells (miPS-LLCev) expressed Nanog and Oct3/4 proteins comparable to miPSCs. The frequency of sphere formation of the miPS-LLCev cells in suspension culture indicated that the self-renewal capacity of the miPS-LLCev cells was significant. When the miPS-LLCev cells were subcutaneously transplanted into Balb/c nude mice, malignant liposarcomas with extensive angiogenesis developed. miPS-LLCevPT and miPS-LLCevDT, the cells established from primary site and disseminated liposarcomas, respectively, showed their capacities to self-renew and differentiate into adipocytes and endothelial cells. Moreover, we confirmed the secondary liposarcoma development when these cells were transplanted. Taken together, these results indicate that miPS-LLCev cells possess CSC properties. Thus, our current study provides the first evidence that tEVs have the potential to induce CSC properties in normal tissue stem cells/progenitors. PMID:25057308

Hyperthermal (1-100 eV) nitrogen ion scattering damage to D-ribose and 2-deoxy-D-ribose films

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

Deng Zongwu; Bald, Ilko; Illenberger, Eugen

2007-10-14

Highly charged heavy ion traversal of a biological medium can produce energetic secondary fragment ions. These fragment ions can in turn cause collisional and reactive scattering damage to DNA. Here we report hyperthermal (1-100 eV) scattering of one such fragment ion (N{sup +}) from biologically relevant sugar molecules D-ribose and 2-deoxy-D-ribose condensed on polycrystalline Pt substrate. The results indicate that N{sup +} ion scattering at kinetic energies down to 10 eV induces effective decomposition of both sugar molecules and leads to the desorption of abundant cation and anion fragments. Use of isotope-labeled molecules (5-{sup 13}C D-ribose and 1-D D-ribose) partlymore » reveals some site specificity of the fragment origin. Several scattering reactions are also observed. Both ionic and neutral nitrogen atoms abstract carbon from the molecules to form CN{sup -} anion at energies down to {approx}5 eV. N{sup +} ions also abstract hydrogen from hydroxyl groups of the molecules to form NH{sup -} and NH{sub 2}{sup -} anions. A fraction of O/O{sup -} fragments abstract hydrogen to form OH{sup -}. The formation of H{sub 3}O{sup +} ions also involves hydrogen abstraction as well as intramolecular proton transfer. These findings suggest a variety of severe damaging pathways to DNA molecules which occur on the picosecond time scale following heavy ion irradiation of a cell, and prior to the late diffusion-limited homogeneous chemical processes.« less

Leishmania infantum Exoproducts Inhibit Human Invariant NKT Cell Expansion and Activation.

PubMed

Belo, Renata; Santarém, Nuno; Pereira, Cátia; Pérez-Cabezas, Begoña; Macedo, Fátima; Leite-de-Moraes, Maria; Cordeiro-da-Silva, Anabela

2017-01-01

Leishmania infantum is one of the major parasite species associated with visceral leishmaniasis, a severe form of the disease that can become lethal if untreated. This obligate intracellular parasite has developed diverse strategies to escape the host immune response, such as exoproducts (Exo) carrying a wide range of molecules, including parasite virulence factors, which are potentially implicated in early stages of infection. Herein, we report that L. infantum Exo and its two fractions composed of extracellular vesicles (EVs) and vesicle-depleted-exoproducts (VDEs) inhibit human peripheral blood invariant natural killer T (iNKT) cell expansion in response to their specific ligand, the glycolipid α-GalactosylCeramide (α-GalCer), as well as their capacity to promptly produce IL-4 and IFNγ. Using plate-bound CD1d and α-GalCer, we found that Exo, EV, and VDE fractions reduced iNKT cell activation in a dose-dependent manner, suggesting that they prevented α-GalCer presentation by CD1d molecules. This direct effect on CD1d was confirmed by the observation that CD1d:α-GalCer complex formation was impaired in the presence of Exo, EV, and VDE fractions. Furthermore, lipid extracts from the three compounds mimicked the inhibition of iNKT cell activation. These lipid components of L. infantum exoproducts, including EV and VDE fractions, might compete for CD1-binding sites, thus blocking iNKT cell activation. Overall, our results provide evidence for a novel strategy through which L. infantum can evade immune responses of mammalian host cells by preventing iNKT lymphocytes from recognizing glycolipids in a TCR-dependent manner.

Drop-In Alternative Jet Fuels: Status of DoDs RDT and E, Interagency Initiatives, and Policies

DTIC Science & Technology

2015-08-25

biodiesel , EVs, natural gas Drivers: Compliance and cost Market penetration: ᝺% of fuel use 3 INSTALLATIONS (COMPLIANCE) Military...including pure  biodiesel  (B100))1 – P‐Series.2 4 Why does DoD Care about “Drop‐in” Alternative Fuels for Operational Platforms? • Fuels for operations make

Marine Seismic System At-Sea-Test Deployment Operation

DTIC Science & Technology

1981-10-09

ton crane can handle deck loads. An early version Deloo type ASK ( Automatic Stationkeeping) system is used to maintain position over a deployed short...b --- 00 - Ir RPT 006-007EV "A 126283 [ I iMIIE SEISMIC SYSTEM I AT-SEA-TEST DEP OYiN OFERATION I GLOBAL MARINE DEVELOPMENT INC 2302 Martin Street...Seismic System At-Sea-Test Deployment Operation 6. PERFORNING *o. REPORT NUMOER IPT 006-007 7. AUTNMORI) O. CONTRACT Ol GRANT NUMOERIa iR. Wallerstedt

The SGR-ReSI and its application for GNSS reflectometry on the NASA EV-2 CYGNSS mission

NASA Astrophysics Data System (ADS)

Unwin, M.; Jales, P.; Blunt, P.; Duncan, S.; Brummitt, M.; Ruf, C.

As part of the EV-2 Cyclone Global Navigation Satellite System (CYGNSS) mission team, Surrey will be providing the Delay Doppler Mapping Instrument (DDMI) for eight Observatories designed and built by the University of Michigan and Southwest Research Institute (SwRI). Following the success of the GPS Reflectometry Experiment on the UK-DMC 1 satellite launched in 2003, Surrey has developed the SGR-ReSI as a move towards operational reflectometry and other applications. The Space GPS Receiver Remote Sensing Instrument (SGR-ReSI) is a COTS-electronics based GNSS receiver which can support up to eight programmable front-ends. It allows collection of raw sampled data but also is capable of processing the reflections into Delay Doppler Maps in real time. The first flight of the SGR-ReSI will be on the UK TechDemoSat-1 to prove the instrument and its various applications. The SGR-ReSI on CYGNSS has a different configuration to that on TechDemoSat-1 which is needed to focus on the requirements for operational cyclone sensing.

Hot ion plasma production in HIP-1 using water-cooled hollow cathodes

NASA Technical Reports Server (NTRS)

Reinmann, J. J.; Lauver, M. R.; Patch, R. W.; Layman, R. W.; Snyder, A.

1975-01-01

A steady-state ExB plasma was formed by applying a strong radially inward dc electric field near the mirror throats. Most of the results were for hydrogen, but deuterium and helium plasmas were also studied. Three water-cooled hollow cathodes were operated in the hot-ion plasma mode with the following results: (1) thermally emitting cathodes were not required to achieve the hot-ion mode; (2) steady-state operation (several minutes) was attained; (3) input powers greater than 40 kW were achieved; (4) cathode outside diameters were increased from 1.2 cm (uncooled) to 4.4 cm (water-cooled); (5) steady-state hydrogen plasma with ion temperatures from 185 to 770 eV and electron temperatures from 5 to 21 eV were produced. Scaling relations were empirically obtained for discharge current, ion temperature, electron temperature, and relative ion density as a function of hydrogen gas feed rate, magnetic field, and cathode voltage. Neutrons were produced from deuterium plasma, but it was not established whether thay came from the plasma volume or from the electrode surfaces.

A Penning sputter ion source with very low energy spread

NASA Astrophysics Data System (ADS)

Nouri, Z.; Li, R.; Holt, R. A.; Rosner, S. D.

2010-03-01

We have developed a version of the Frankfurt Penning ion source that produces ion beams with very low energy spreads of ˜3 eV, while operating in a new discharge mode characterized by very high pressure, low voltage, and high current. The extracted ions also comprise substantial metastable and doubly charged species. Detailed studies of the operating parameters of the source showed that careful adjustment of the magnetic field and gas pressure is critical to achieving optimum performance. We used a laser-fluorescence method of energy analysis to characterize the properties of the extracted ion beam with a resolving power of 1×10 4, and to measure the absolute ion beam energy to an accuracy of 4 eV in order to provide some insight into the distribution of plasma potential within the ion source. This characterization method is widely applicable to accelerator beams, though not universal. The low energy spread, coupled with the ability to produce intense ion beams from almost any gas or conducting solid, make this source very useful for high-resolution spectroscopic measurements on fast-ion beams.

Non-Volatile High Speed & Low Power Charge Trapping Devices

NASA Astrophysics Data System (ADS)

Kim, Moon Kyung; Tiwari, Sandip

2007-06-01

We report the operational characteristics of ultra-small-scaled SONOS (below 50 nm gate width and length) and SiO2/SiO2 structural devices with 0.5 um gate width and length where trapping occurs in a very narrow region. The experimental work summarizes the memory characteristics of retention time, endurance cycles, and speed in SONOS and SiO2/SiO2 structures. Silicon nitride has many defects to hold electrons as charge storage media in SONOS memory. Defects are also incorporated during growth and deposition in device processing. Our experiments show that the interface between two oxides, one grown and one deposited, provides a remarkable media for electron storage with a smaller gate stack and thus lower operating voltage. The exponential dependence of the time on the voltage is reflected in the characteristic energy. It is ˜0.44 eV for the write process and ˜0.47 eV for the erase process in SiO2/SiO2 structural device which is somewhat more efficient than those of SONOS structure memory.

An enhanced Enterovirus surveillance system allows identification and characterization of rare and emerging respiratory enteroviruses in Denmark, 2015-16.

PubMed

Barnadas, Céline; Midgley, Sofie E; Skov, Marianne N; Jensen, Lotte; Poulsen, Mille W; Fischer, Thea Kølsen

2017-08-01

The potential for outbreaks due to Enteroviruses (EV) with respiratory tropism, such as EV-D68, and the detection of new and rare EV species C is a concern. These EVs are typically not detected in stool specimens and may therefore be missed by standard EV surveillance systems. Following the North American outbreak of EV-D68 in 2014, Denmark piloted an enhanced EV surveillance system that included the screening of respiratory samples. We aim to report clinical manifestations and phylogenetic descriptions from the rare and emerging EVs identified thereby demonstrating the usefulness of this system. Positive EV samples received through the enhanced non-polio EV pilot surveillance system were characterized by sequencing fragments of VP1, VP2 and VP4 capsid proteins and clinical observations were compiled. Between January 2015 and October 2016, six cases of rare genotypes EV-C104, C105 and C109 and nine cases of EV-D68 were identified. Patients presented with mild to moderately severe respiratory illness; no paralysis occurred. Distinct EV-C104, EV-C109 and EV-D68 sequences argue against a common source of introduction of these genotypes in the Danish population. The enhanced EV surveillance system enabled detection and characterization of rare EVs in Denmark. In order to improve our knowledge of and our preparedness against emerging EVs, public health laboratories should consider expanding their EV surveillance system to include respiratory specimens. Copyright © 2017 Elsevier B.V. All rights reserved.

Modification of the amorphous carbon films by the ns-laser irradiation

NASA Astrophysics Data System (ADS)

Grigonis, Alfonsas; Marcinauskas, Liutauras; Vinciunaite, Vinga; Raciukaitis, Gediminas

2011-10-01

The effect of a nanosecond laser irradiation of thin (60 and 145 nm) amorphous, diamond-like carbon films deposited on Si substrate by an ion beam deposition (IBD) from pure acetylene and acetylene/hydrogen (1:2) gas mixture was analyzed in this work. The films were irradiated with the infrared (IR) and ultraviolet (UV) radiation of the nanosecond Nd:YAG lasers working at the first (1.16 eV) and the third (3.48 eV) harmonics, using a multi-shot regime. The IR laser irradiation stimulated a minor increase in the fraction of sp2 bonds, causing a slight decrease in the hardness of the films and initiated SiC formation. Irradiation with the UV laser caused the formation of carbides and increased hydrogenization of the Si substrate and the fraction of sp2 sites. Spalliation and ablation were observed at a higher energy density and with a large number of laser pulses per spot.

How does methylation suppress the electron-induced decomposition of 1-methyl-nitroimidazoles?

NASA Astrophysics Data System (ADS)

Kossoski, F.; Varella, M. T. do N.

2017-10-01

The efficient decomposition of nitroimidazoles (NIs) by low energy electrons is believed to underlie their radiosensitizing properties. Recent dissociative electron attachment (DEA) measurements showed that methylation at the N1 site unexpectedly suppresses the electron-induced reactions in 4(5)-NI. We report theoretical results that provide a clear interpretation of that astounding finding. Around 1.5 eV, DEA reactions into several fragments are initiated by a π* resonance, not considered in previous studies. The autoionization lifetime of this anion state, which limits the predissociation dynamics, is considerably shorter in the methylated species, thereby suppressing the DEA signals. On the other hand, the lifetime of the π* resonance located around 3 eV is less affected by methylation, which explains why DEA is still observed at these energies. Our results demonstrate how even a simple methylation can significantly modify the probabilities for DEA reactions, which may be significant for NI-based cancer therapy.

Battery Electric Vehicle Driving and Charging Behavior Observed Early in The EV Project

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

John Smart; Stephen Schey

2012-04-01

As concern about society's dependence on petroleum-based transportation fuels increases, many see plug-in electric vehicles (PEV) as enablers to diversifying transportation energy sources. These vehicles, which include plug-in hybrid electric vehicles (PHEV), range-extended electric vehicles (EREV), and battery electric vehicles (BEV), draw some or all of their power from electricity stored in batteries, which are charged by the electric grid. In order for PEVs to be accepted by the mass market, electric charging infrastructure must also be deployed. Charging infrastructure must be safe, convenient, and financially sustainable. Additionally, electric utilities must be able to manage PEV charging demand on themore » electric grid. In the Fall of 2009, a large scale PEV infrastructure demonstration was launched to deploy an unprecedented number of PEVs and charging infrastructure. This demonstration, called The EV Project, is led by Electric Transportation Engineering Corporation (eTec) and funded by the U.S. Department of Energy. eTec is partnering with Nissan North America to deploy up to 4,700 Nissan Leaf BEVs and 11,210 charging units in five market areas in Arizona, California, Oregon, Tennessee, and Washington. With the assistance of the Idaho National Laboratory, eTec will collect and analyze data to characterize vehicle consumer driving and charging behavior, evaluate the effectiveness of charging infrastructure, and understand the impact of PEV charging on the electric grid. Trials of various revenue systems for commercial and public charging infrastructure will also be conducted. The ultimate goal of The EV Project is to capture lessons learned to enable the mass deployment of PEVs. This paper is the first in a series of papers documenting the progress and findings of The EV Project. This paper describes key research objectives of The EV Project and establishes the project background, including lessons learned from previous infrastructure deployment and PEV demonstrations. One such previous study was a PHEV demonstration conducted by the U.S. Department of Energy's Advanced Vehicle Testing Activity (AVTA), led by the Idaho National Laboratory (INL). AVTA's PHEV demonstration involved over 250 vehicles in the United States, Canada, and Finland. This paper summarizes driving and charging behavior observed in that demonstration, including the distribution of distance driven between charging events, charging frequency, and resulting proportion of operation charge depleting mode. Charging demand relative to time of day and day of the week will also be shown. Conclusions from the PHEV demonstration will be given which highlight the need for expanded analysis in The EV Project. For example, the AVTA PHEV demonstration showed that in the absence of controlled charging by the vehicle owner or electric utility, the majority of vehicles were charged in the evening hours, coincident with typical utility peak demand. Given this baseline, The EV Project will demonstrate the effects of consumer charge control and grid-side charge management on electricity demand. This paper will outline further analyses which will be performed by eTec and INL to documenting driving and charging behavior of vehicles operated in a infrastructure-rich environment.« less

Characterisation of adipocyte-derived extracellular vesicle subtypes identifies distinct protein and lipid signatures for large and small extracellular vesicles

PubMed Central

Durcin, Maëva; Fleury, Audrey; Taillebois, Emiliane; Hilairet, Grégory; Krupova, Zuzana; Henry, Céline; Truchet, Sandrine; Trötzmüller, Martin; Köfeler, Harald; Mabilleau, Guillaume; Hue, Olivier; Andriantsitohaina, Ramaroson; Martin, Patrice; Le Lay, Soazig

2017-01-01

ABSTRACT Extracellular vesicles (EVs) are biological vectors that can modulate the metabolism of target cells by conveying signalling proteins and genomic material. The level of EVs in plasma is significantly increased in cardiometabolic diseases associated with obesity, suggesting their possible participation in the development of metabolic dysfunction. With regard to the poor definition of adipocyte-derived EVs, the purpose of this study was to characterise both qualitatively and quantitatively EVs subpopulations secreted by fat cells. Adipocyte-derived EVs were isolated by differential centrifugation of conditioned media collected from 3T3-L1 adipocytes cultured for 24 h in serum-free conditions. Based on morphological and biochemical properties, as well as quantification of secreted EVs, we distinguished two subpopulations of adipocyte-derived EVs, namely small extracellular vesicles (sEVs) and large extracellular vesicles (lEVs). Proteomic analyses revealed that lEVs and sEVs exhibit specific protein signatures, allowing us not only to define novel markers of each population, but also to predict their biological functions. Despite similar phospholipid patterns, the comparative lipidomic analysis performed on these EV subclasses revealed a specific cholesterol enrichment of the sEV population, whereas lEVs were characterised by high amounts of externalised phosphatidylserine. Enhanced secretion of lEVs and sEVs is achievable following exposure to different biological stimuli related to the chronic low-grade inflammation state associated with obesity. Finally, we demonstrate the ability of primary murine adipocytes to secrete sEVs and lEVs, which display physical and biological characteristics similar to those described for 3T3-L1. Our study provides additional information and elements to define EV subtypes based on the characterisation of adipocyte-derived EV populations. It also underscores the need to distinguish EV subpopulations, through a combination of multiple approaches and markers, since their specific composition may cause distinct metabolic responses in recipient cells and tissues. PMID:28473884

Study of organic radicals through anion photoelectron velocity-map imaging spectroscopy

NASA Astrophysics Data System (ADS)

Dixon, Andrew Robert

We report preliminary results on the photoelectron imaging of phenylcarbene, cyanophenylcarbene, and chlorophenylcarbene anions. Triplet phenylcarbene is observed to have an EA of ≤ 0.83 eV, considerably lower than the previously indirectly-determined value. Transitions to the singlet and triplet ground state of both cyanophenylcarbene and chlorophenylcarbene are observable, though unidentified bands make full assignment difficult. Cyanophenylcarbene is found to have a triplet ground-state, with a tentative EA of 2.04 eV. Chlorophenylcarbene is found to have a singlet ground-state. The phenyl-group is found to favor the singlet state slightly. The cyanofluoromethyl radical, FC(H)CN, was estimated to have an EA of 1.53 +/- 0.08 eV, by a combination of experimental and theoretical results.. With similar methodology, we report the adiabatic electron affinity of the cyanobenzyl radical, EA(PhCHCN) = 1.90 +/- 0.01 eV, and assign an upper limit of the EA for the chlorobenzyl radical, EA(PhCHCl) ≤ 1.12 eV. These values were used to estimate the C-H bond dissociation energy (BDE)s for these substituted methanes. Fluoroacetonitrile was found to have a BDE of D H198 = 90.7 +/- 2.8 kcal mol□1. The C-H bond dissociation energies at the benzyl-alpha sites of the phenylmethanes are determined as 80.9 +/- 2.3 kcal mol-1 for benzyl nitrile and an upper limit of 84.2 kcal mol-1 for benzyl chloride. These results are discussed in terms of substituent interactions in a simple MO framework and in relation to other similar molecules, including recently reported results for chloroacetonitrile. The 532 nm photoelectron spectrum of glyoxal provides the first direct spectroscopic determination of the adiabatic electron affinity, EA = 1.10(2) eV. This assignment is supported by a Franck-Condon simulation of the experimental spectrum that successfully reproduces the observed spectral features. The vertical detachment energy (VDE) of the glyoxal radical anion is determined as VDE = 1.30(4) eV. The EA of methylglyoxal is determined as ≤ 0.8 eV based on the signal-to-noise ratio of the X 1A ' ← X 2A'' transition, with a VDE = 1.28(4) eV. The EA of the a 3A'' ← X 2A '' and A 1A'' ← X 2A'' transitions are determined as 3.28(3) eV and 3.614(5) eV respectively. The intrinsically short-lived ethylenedione molecule (OCCO) was observed and investigated using anion photoelectron spectroscopy. The adiabatic electron affinity of its 3Sigmag □ ground state is 1.936(8) eV. The vibrational progression with a 417(15) cm-1 frequency observed within the triplet band corresponds to a trans-bending mode. Several dissociative singlet states are also observed, corresponding to two components of the 1Delta g state and the 1Sigmag + state. The experimental results are in agreement with the theory predictions and constitute the first spectroscopic observation and characterization of the elusive ethylenedione molecule. Two glyoxal derivatives related to the ethylenedione anion (OCCO -), ethynediolide (HOCCO-) and glyoxalide (OHCCO-), were studied. These anions provide access to the corresponding neutral reactive intermediates: the HOCCO and OHCCO radicals. In the HOCCO/OHCCO anion photoelectron spectrum, we identify several electronic states of this radical system and determine the adiabatic electron affinity of HOCCO as 1.763(6) eV. This result is compared to the corresponding 1.936(8) eV value for ethylenedione (OCCO). Initial attempts were made to detect and observe the dicyanoacetylene anion, NCCCCN- , by photoelectron imaging. While it is believed the experimental design path of H2+ abstraction from fumaronitrile is sound, no spectral signature can be assigned to NCCCCN -. Calculations targeting the low-lying transitions from the anion indicate that the molecule should have a significantly positive electron affinity and at least the ground state should be accessible with the currently available laser sources. The cluster ion O2(N2O) of the same nominal mass as NCCCCN- is identified as an interfering ion and ideas have been proposed for resolving this difficulty. (Abstract shortened by ProQuest.).

Computational study of sodium magnesium hydride for hydrogen storage applications

NASA Astrophysics Data System (ADS)

Soto Valle, Fernando Antonio

Hydrogen offers considerable potential benefits as an energy carrier. However, safe and convenient storage of hydrogen is one of the biggest challenges to be resolved in the near future. Sodium magnesium hydride (NaMgH 3) has attracted attention as a hydrogen storage material due to its light weight and high volumetric hydrogen density of 88 kg/m3. Despite the advantages, hydrogen release in this material occurs at approximately 670 K, which is well above the operable range for on-board hydrogen storage applications. In this regard, hydrogen release may be facilitated by substitution doping of transition-metals. This dissertation describes first-principles computational methods that enable an examination of the hydrogen storage properties of NaMgH3. The novel contribution of this dissertation includes a combination of crystal, supercell, and surface slab calculations that provides new and relevant insights about the thermodynamic and kinetic properties of NaMgH3. First-principles calculations on the pristine crystal structure provide a starting reference point for the study of this material as a hydrogen storage material. To the best of our knowledge, it is reported for the first time that a 25% mol doping concentration of Ti, V, Cu, and Zn dopants reduce the reaction enthalpy of hydrogen release for NaMgH3. The largest decrease in the DeltaH(298 K) value corresponds to the Zn-doped model (67.97 kJ/(mol H2)). Based on cohesive energy calculations, it is reported that at the 6.25% mol doping concentration, Ti and Zn dopants are the only transition metals that destabilize the NaMgH3 hydride. In terms of hydrogen removal energy, it is quantified that the energy cost to remove a single H from the Ti-doped supercell model is 0.76 eV, which is lower with respect to the pristine model and other prototypical hydrogen storage materials. From the calculation of electronic properties such as density of states, electron density difference, and charge population analysis schemes it is shown that the effectiveness of these two dopants is due to the modified chemical bonding induce by the overlap of d orbitals. For the surface slab calculations, a key finding is that the preferred layer for the simultaneous substitution of Ti and Zn dopants at two different Na sites is the outermost layer with substitution energy values of -5.27 eV and -5.24 eV, respectively. The kinetic barrier for hydrogen desorption from the (001) surface is studied using DFT calculations, LST/QST, and NEB methods. We find that for the pristine model, the direct recombination of a H 2 molecule has a kinetic barrier of 1.16 eV. More importantly, we find that the calculated kinetic barrier of H2 desorption when the (001) surface is co-doped with Ti and Zn is 0.42 eV. These results show that the combined use of a Ti dopant and a Zn dopant is the best mix for reducing the energy barrier to release hydrogen from the (001) NaMgH3 surface.

Ergonomic Synthesis Suitable for Industrial Production of Silver-Festooned Zinc Oxide Nanorods

NASA Astrophysics Data System (ADS)

Khan, G. R.; Khan, R. A.

2015-07-01

For maximizing productivity, minimizing cost, time-boxing process and optimizing human effort, a single-step, cost-effective, ultra-fast and environmentally benign synthesis suitable for industrial production of nanocrystalline ZnO, and Ag-doped ZnO has been reported in this paper. The synthesis based on microwave-supported aqueous solution method used zinc acetate dehydrate and silver nitrate as precursors for fabrication of nanorods. The synthesized products were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and UV-Vis-NIR spectroscopy. The undoped and Ag-doped ZnO nanorods crystallized in a hexagonal wurtzite structure having spindle-like morphology. The blue shift occurred at absorption edge of Ag-doped ZnO around 260 nm compared to 365 nm of bulk ZnO. The red shift occurred at Raman peak site of 434 cm-1 compared to characteristic wurtzite phase peak of ZnO (437 cm-1). The bandgap energies were found to be 3.10 eV, 3.11 eV and 3.18 eV for undoped, 1% Ag-doped, and 3% Ag-doped ZnO samples, respectively. The TEM results provided average particle sizes of 17 nm, 15 nm and 13 nm for undoped, and 1% and 3% Ag-doped ZnO samples, respectively.

Stabilization of Reactive MgO Surfaces by Ni Doping

NASA Astrophysics Data System (ADS)

Mazheika, Aliaksei; Levchenko, Sergey V.

Ni-MgO solid solutions are promising materials for catalytic reduction of CO2 and dry reforming of CH4. To explain the catalytic activity, an ab initio study of Ni-substitutional defects in MgO (NiMg) has been performed. At first, the validation of the theory level was done. We compared results of CCSD(T) embedded-cluster calculations of NiMg formation energies and adsorption energies of CO, CO2 and H2 on them to the HSE(α) hybrid DFT functional with the fraction of the exact exchange α varied between 0 and 1. HSE(0.3) was found to be the best compromise in this study. Our periodic HSE(0.3) calculations show that NiMg defects are most stable at corner sites, followed by steps, and are least stable at (001) terraces. Thus, Ni-doping stabilizes stepped MgO surfaces. The dissociative adsorption of H2 on the terrace is found to be endothermic (+ 1 . 1 eV), whereas on (110) surface with NiMg it is highly exothermic (- 1 . 6 eV). Adsorbed CO2 is also significantly stabilized (- 0 . 6 vs. - 2 . 2 eV). These findings explain recent microcalorimetry measurements of H2 and CO2 adsorption at doped Ni-MgO samples. partially supported by UniCat (Deutsche Forschungsgemeinschaft).

Optical and Magnetic Resonance Studies of Na-Diffused ZnO Bulk Single Crystals

NASA Astrophysics Data System (ADS)

Glaser, E. R.; Garces, N. Y.; Parmar, N. S.; Lynn, K. G.

2013-03-01

Photoluminescence (PL) and optically-detected magnetic resonance (ODMR) at 24 GHz were performed on bulk ZnO crystals after diffusion of Na impurities that were explored as an alternate doping source for p-type conductivity. PL at 2K revealed strong bandedge excitonic recombination at 3.361 eV and a broad ``orange'' PL band at 2.17 eV with FWHM of ~0.5 eV. This ``orange'' emission is very similar to that reported previously[1] from thermoluminescence measurements of intentionally Na-doped bulk ZnO and, thus, strongly suggests the incorporation and activation of the Na-diffused impurities. ODMR performed on this ``orange'' PL revealed two signals. The first was a sharp feature with g-value of ~1.96 and is a well-known ``fingerprint'' of shallow donors in ZnO. The second signal consisted of a pair of lines with an intensity ratio of ~3:1 and with g-tensors (g∥,g⊥ ~2.008-2.029) very similar to ESR signals attributed previously[2] to holes bound to Na impurities located at the axial and non-axial Zn host lattice sites in Na-doped ZnO. Thus, the ``orange'' PL can be tentatively assigned to radiative recombination between residual shallow donors and deep Na-related hole traps.

High frequency of Polio-like Enterovirus C strains with differential clustering of CVA-13 and EV-C99 subgenotypes in a cohort of Malawian children.

PubMed

Brouwer, Lieke; van der Sanden, Sabine M G; Calis, Job C J; Bruning, Andrea H L; Wang, Steven; Wildenbeest, Joanne G; Rebers, Sjoerd P H; Phiri, Kamija S; Westerhuis, Brenda M; van Hensbroek, Michaël Boele; Pajkrt, Dasja; Wolthers, Katja C

2018-05-28

Enteroviruses (EVs) are among the most commonly detected viruses infecting humans worldwide. Although the prevalence of EVs is widely studied, the status of EV prevalence in sub-Saharan Africa remains largely unknown. The objective of our present study was therefore to increase our knowledge on EV circulation in sub-Saharan Africa. We obtained 749 fecal samples from a cross-sectional study conducted on Malawian children aged 6 to 60 months. We tested the samples for the presence of EVs using real time PCR, and typed the positive samples based on partial viral protein 1 (VP1) sequences. A large proportion of the samples was EV positive (89.9%). 12.9% of the typed samples belonged to EV species A (EV-A), 48.6% to species B (EV-B) and 38.5% to species C (EV-C). More than half of the EV-C strains (53%) belonged to subgroup C containing, among others, Poliovirus (PV) 1-3. The serotype most frequently isolated in our study was CVA-13, followed by EV-C99. The strains of CVA-13 showed a vast genetic diversity, possibly representing a new cluster, 'F'. The majority of the EV-C99 strains grouped together as cluster B. In conclusion, this study showed a vast circulation of EVs among Malawian children, with an EV prevalence of 89.9%. Identification of prevalences for species EV-C comparable to our study (38.5%) have only previously been reported in sub-Saharan Africa, and EV-C is rarely found outside of this region. The data found in this study are an important contribution to our current knowledge of EV epidemiology within sub-Saharan Africa.

High-resolution x-ray spectroscopy with the EBIT Calorimeter Spectrometer

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

Porter, F. Scott; Adams, Joseph S.; Kelley, Richard L.

The EBIT Calorimeter Spectrometer (ECS) is a production-class 36 pixel x-ray calorimeter spectrometer that has been continuously operating at the Electron Beam Ion Trap (EBIT) facility at Lawrence Livermore National Laboratory for almost 2 years. The ECS was designed to be a long-lifetime, turn-key spectrometer that couples high performance with ease of operation and minimal operator intervention. To this end, a variant of the Suzaku/XRS spaceflight detector system has been coupled to a low-maintenance cryogenic system consisting of a long-lifetime liquid He cryostat, and a closed cycle, {sup 3}He pre-cooled adiabatic demagnetization refrigerator. The ECS operates for almost 3 weeksmore » between cryogenic servicing and the ADR operates at 0.05 K for more than 60 hours between automatic recycles under software control. Half of the ECS semiconductor detector array is populated with mid-band pixels that have a resolution of 4.5 eV FWHM, a bandpass from 0.05-12 keV, and a quantum efficiency of 95% at 6 keV. The other half of the array has thick HgTe absorbers that have a bandpass from 0.3 to over 100 keV, an energy resolution of 33 eV FWHM, and a quantum efficiency of 32% at 60 keV. In addition, the ECS uses a real-time, autonomous, data collection and analysis system developed for the Suzaku/XRS instrument and implemented in off-the-shelf hardware for the ECS. Here we will discuss the performance of the ECS instrument and its implementation as a turnkey cryogenic detector system.« less

Room temperature large-scale synthesis of layered frameworks as low-cost 4 V cathode materials for lithium ion batteries.

PubMed

Hameed, A Shahul; Reddy, M V; Nagarathinam, M; Runčevski, Tomče; Dinnebier, Robert E; Adams, Stefan; Chowdari, B V R; Vittal, Jagadese J

2015-11-23

Li-ion batteries (LIBs) are considered as the best available technology to push forward the production of eco-friendly electric vehicles (EVs) and for the efficient utilization of renewable energy sources. Transformation from conventional vehicles to EVs are hindered by the high upfront price of the EVs and are mainly due to the high cost of LIBs. Hence, cost reduction of LIBs is one of the major strategies to bring forth the EVs to compete in the market with their gasoline counterparts. In our attempt to produce cheaper high-performance cathode materials for LIBs, an rGO/MOPOF (reduced graphene oxide/Metal-Organic Phosphate Open Framework) nanocomposite with ~4 V of operation has been developed by a cost effective room temperature synthesis that eliminates any expensive post-synthetic treatments at high temperature under Ar/Ar-H2. Firstly, an hydrated nanocomposite, rGO/K2[(VO)2(HPO4)2(C2O4)]·4.5H2O has been prepared by simple magnetic stirring at room temperature which releases water to form the anhydrous cathode material while drying at 90 °C during routine electrode fabrication procedure. The pristine MOPOF material undergoes highly reversible lithium storage, however with capacity fading. Enhanced lithium cycling has been witnessed with rGO/MOPOF nanocomposite which exhibits minimal capacity fading thanks to increased electronic conductivity and enhanced Li diffusivity.

Electronic properties of light-induced recombination centers in boron-doped Czochralski silicon

NASA Astrophysics Data System (ADS)

Schmidt, Jan; Cuevas, Andrés

1999-09-01

In order to study the electronic properties of the recombination centers responsible for the light-induced carrier lifetime degradation commonly observed in high-purity boron-doped Czochralski (Cz) silicon, injection-level dependent carrier lifetime measurements are performed on a large number of boron-doped p-type Cz silicon wafers of various resistivities (1-31 Ω cm) prior to and after light degradation. The measurement technique used is the contactless quasi-steady-state photoconductance method, allowing carrier lifetime measurements over a very broad injection range between 1012 and 1017cm-3. To eliminate all recombination channels not related to the degradation effect, the difference of the inverse lifetimes measured after and before light degradation is evaluated. A detailed analysis of the injection level dependence of the carrier lifetime change using the Shockley-Read-Hall theory shows that the fundamental recombination center created during illumination has an energy level between Ev+0.35 and Ec-0.45 eV and an electron/hole capture time constant ratio between 0.1 and 0.2. This deep-level center is observed in all samples and is attributed to a new type of boron-oxygen complex. Besides this fundamental defect, in some samples an additional shallow-level recombination center at 0.15 eV below Ec or above Ev is found to be activated during light exposure. This second center dominates the light-degraded carrier lifetime only under high-injection conditions and is hence only of minor importance for low-injection operated devices.

Room temperature large-scale synthesis of layered frameworks as low-cost 4 V cathode materials for lithium ion batteries

PubMed Central

Hameed, A. Shahul; Reddy, M. V.; Nagarathinam, M.; Runčevski, Tomče; Dinnebier, Robert E; Adams, Stefan; Chowdari, B. V. R.; Vittal, Jagadese J.

2015-01-01

Li-ion batteries (LIBs) are considered as the best available technology to push forward the production of eco-friendly electric vehicles (EVs) and for the efficient utilization of renewable energy sources. Transformation from conventional vehicles to EVs are hindered by the high upfront price of the EVs and are mainly due to the high cost of LIBs. Hence, cost reduction of LIBs is one of the major strategies to bring forth the EVs to compete in the market with their gasoline counterparts. In our attempt to produce cheaper high-performance cathode materials for LIBs, an rGO/MOPOF (reduced graphene oxide/Metal-Organic Phosphate Open Framework) nanocomposite with ~4 V of operation has been developed by a cost effective room temperature synthesis that eliminates any expensive post-synthetic treatments at high temperature under Ar/Ar-H2. Firstly, an hydrated nanocomposite, rGO/K2[(VO)2(HPO4)2(C2O4)]·4.5H2O has been prepared by simple magnetic stirring at room temperature which releases water to form the anhydrous cathode material while drying at 90 °C during routine electrode fabrication procedure. The pristine MOPOF material undergoes highly reversible lithium storage, however with capacity fading. Enhanced lithium cycling has been witnessed with rGO/MOPOF nanocomposite which exhibits minimal capacity fading thanks to increased electronic conductivity and enhanced Li diffusivity. PMID:26593096

Room temperature large-scale synthesis of layered frameworks as low-cost 4 V cathode materials for lithium ion batteries

NASA Astrophysics Data System (ADS)

Hameed, A. Shahul; Reddy, M. V.; Nagarathinam, M.; Runčevski, Tomče; Dinnebier, Robert E.; Adams, Stefan; Chowdari, B. V. R.; Vittal, Jagadese J.

2015-11-01

Li-ion batteries (LIBs) are considered as the best available technology to push forward the production of eco-friendly electric vehicles (EVs) and for the efficient utilization of renewable energy sources. Transformation from conventional vehicles to EVs are hindered by the high upfront price of the EVs and are mainly due to the high cost of LIBs. Hence, cost reduction of LIBs is one of the major strategies to bring forth the EVs to compete in the market with their gasoline counterparts. In our attempt to produce cheaper high-performance cathode materials for LIBs, an rGO/MOPOF (reduced graphene oxide/Metal-Organic Phosphate Open Framework) nanocomposite with ~4 V of operation has been developed by a cost effective room temperature synthesis that eliminates any expensive post-synthetic treatments at high temperature under Ar/Ar-H2. Firstly, an hydrated nanocomposite, rGO/K2[(VO)2(HPO4)2(C2O4)]·4.5H2O has been prepared by simple magnetic stirring at room temperature which releases water to form the anhydrous cathode material while drying at 90 °C during routine electrode fabrication procedure. The pristine MOPOF material undergoes highly reversible lithium storage, however with capacity fading. Enhanced lithium cycling has been witnessed with rGO/MOPOF nanocomposite which exhibits minimal capacity fading thanks to increased electronic conductivity and enhanced Li diffusivity.

Climate Control Load Reduction Strategies for Electric Drive Vehicles in Cold Weather

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

Jeffers, Matthew A.; Chaney, Larry; Rugh, John P.

When operated, the climate control system is the largest auxiliary load on a vehicle. This load has significant impact on fuel economy for conventional and hybrid vehicles, and it drastically reduces the driving range of all electric vehicles (EVs). Heating is even more detrimental to EV range than cooling because no engine waste heat is available. Reducing the thermal loads on the heating, ventilating, and air conditioning system will extend driving range and increase the market penetration of EVs. Researchers at the National Renewable Energy Laboratory have evaluated strategies for vehicle climate control load reduction with special attention toward gridmore » connected electric vehicles. Outdoor vehicle thermal testing and computational modeling were used to assess potential strategies for improved thermal management and to evaluate the effectiveness of thermal load reduction technologies. A human physiology model was also used to evaluate the impact on occupant thermal comfort. Experimental evaluations of zonal heating strategies demonstrated a 5.5% to 28.5% reduction in cabin heating energy over a 20-minute warm-up. Vehicle simulations over various drive cycles show a 6.9% to 18.7% improvement in EV range over baseline heating using the most promising zonal heating strategy investigated. A national-level analysis was conducted to determine the overall national impact. If all vehicles used the best zonal strategy, the range would be improved by 7.1% over the baseline heating range. This is a 33% reduction in the range penalty for heating.« less

Climate Control Load Reduction Strategies for Electric Drive Vehicles in Cold Weather: Preprint

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

Jeffers, Matthew; Chaney, Lawrence; Rugh, John

When operated, the climate control system is the largest auxiliary load on a vehicle. This load has significant impact on fuel economy for conventional and hybrid vehicles, and it drastically reduces the driving range of all electric vehicles (EVs). Heating is even more detrimental to EV range than cooling because no engine waste heat is available. Reducing the thermal loads on the heating, ventilating, and air conditioning system will extend driving range and increase the market penetration of EVs. Researchers at the National Renewable Energy Laboratory have evaluated strategies for vehicle climate control load reduction with special attention toward gridmore » connected electric vehicles. Outdoor vehicle thermal testing and computational modeling were used to assess potential strategies for improved thermal management and to evaluate the effectiveness of thermal load reduction technologies. A human physiology model was also used to evaluate the impact on occupant thermal comfort. Experimental evaluations of zonal heating strategies demonstrated a 5.5% to 28.5% reduction in cabin heating energy over a 20-minute warm-up. Vehicle simulations over various drive cycles show a 6.9% to 18.7% improvement in EV range over baseline heating using the most promising zonal heating strategy investigated. A national-level analysis was conducted to determine the overall national impact. If all vehicles used the best zonal strategy, the range would be improved by 7.1% over the baseline heating range. This is a 33% reduction in the range penalty for heating.« less

Giant topological nontrivial band gaps in chloridized gallium bismuthide.

PubMed

Li, Linyang; Zhang, Xiaoming; Chen, Xin; Zhao, Mingwen

2015-02-11

Quantum spin Hall (QSH) effect is promising for achieving dissipationless transport devices but presently is achieved only at extremely low temperature. Searching for the large-gap QSH insulators with strong spin-orbit coupling (SOC) is the key to increase the operating temperature. We demonstrate theoretically that this can be solved in the chloridized gallium bismuthide (GaBiCl2) monolayer, which has nontrivial gaps of 0.95 eV at the Γ point, and 0.65 eV for bulk, as well as gapless edge states in the nanoribbon structures. The nontrivial gaps due to the band inversion and SOC are robust against external strain. The realization of the GaBiCl2 monolayer will be beneficial for achieving QSH effect and related applications at high temperatures.

A brief review on key technologies in the battery management system of electric vehicles

NASA Astrophysics Data System (ADS)

Liu, Kailong; Li, Kang; Peng, Qiao; Zhang, Cheng

2018-04-01

Batteries have been widely applied in many high-power applications, such as electric vehicles (EVs) and hybrid electric vehicles, where a suitable battery management system (BMS) is vital in ensuring safe and reliable operation of batteries. This paper aims to give a brief review on several key technologies of BMS, including battery modelling, state estimation and battery charging. First, popular battery types used in EVs are surveyed, followed by the introduction of key technologies used in BMS. Various battery models, including the electric model, thermal model and coupled electro-thermal model are reviewed. Then, battery state estimations for the state of charge, state of health and internal temperature are comprehensively surveyed. Finally, several key and traditional battery charging approaches with associated optimization methods are discussed.

Self-interaction corrected LDA + U investigations of BiFeO3 properties: plane-wave pseudopotential method

NASA Astrophysics Data System (ADS)

Yaakob, M. K.; Taib, M. F. M.; Lu, L.; Hassan, O. H.; Yahya, M. Z. A.

2015-11-01

The structural, electronic, elastic, and optical properties of BiFeO3 were investigated using the first-principles calculation based on the local density approximation plus U (LDA + U) method in the frame of plane-wave pseudopotential density functional theory. The application of self-interaction corrected LDA + U method improved the accuracy of the calculated properties. Results of structural, electronic, elastic, and optical properties of BiFeO3, calculated using the LDA + U method were in good agreement with other calculation and experimental data; the optimized choice of on-site Coulomb repulsion U was 3 eV for the treatment of strong electronic localized Fe 3d electrons. Based on the calculated band structure and density of states, the on-site Coulomb repulsion U had a significant effect on the hybridized O 2p and Fe 3d states at the valence and the conduction band. Moreover, the elastic stiffness tensor, the longitudinal and shear wave velocities, bulk modulus, Poisson’s ratio, and the Debye temperature were calculated for U = 0, 3, and 6 eV. The elastic stiffness tensor, bulk modulus, sound velocities, and Debye temperature of BiFeO3 consistently decreased with the increase of the U value.

Electronic structure, optical and thermal/concentration quenching properties of Lu{sub 2−2x}Eu{sub 2x}WO{sub 6} (0 ≤ x ≤0.2)

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

Chen, Xiang-Yang; University of Chinese Academy of Science, Beijing 100039; Zhang, Zhi-Jun, E-mail: zhangzhijun@shu.edu.cn

Highlights: • The band gap of Lu{sub 2}WO{sub 6} is calculated to be 3.13 eV using the CASTEP mode. • Valent state and occupation site of Eu are clarified by X-ray absorption fine structure (XAFS) spectra. • The thermal/concentration quenching mechanisms of Eu in Lu{sub 2}WO{sub 6} have been investigated in detail. - Abstract: Density functional theory calculations on monoclinic Lu{sub 2}WO{sub 6} is carried out using the Cambridge Sequential Total Energy Package code. The result indicates that Lu{sub 2}WO{sub 6} is a broad band gap semiconductor with an indirect band gap of 3.13 eV. Eu ions are trivalency and themore » average coordination number is 7.6(5), indicating that the site of Lu is occupied by Eu. The activation energy ΔE is calculated as 0.314 eV. In addiation, the thermal quenching mechnism of Eu-activated Lu{sub 2}WO{sub 6} and the different concentration quenching mechanisms for {sup 5}D{sub 0} and {sup 5}D{sub 1} emissions of Eu ions have been proposed.« less

Nitrogen-doped fullerene as a potential catalyst for hydrogen fuel cells.

PubMed

Gao, Feng; Zhao, Guang-Lin; Yang, Shizhong; Spivey, James J

2013-03-06

We examine the possibility of nitrogen-doped C60 fullerene (N-C60) as a cathode catalyst for hydrogen fuel cells. We use first-principles spin-polarized density functional theory calculations to simulate the electrocatalytic reactions on N-C60. The first-principles results show that an O2 molecule can be adsorbed and partially reduced on the N-C complex sites (Pauling sites) of N-C60 without any activation barrier. Through a direct pathway, the partially reduced O2 can further react with H(+) and additional electrons and complete the water formation reaction (WFR) with no activation energy barrier. In the indirect pathway, reduced O2 reacts with H(+) and additional electrons to form H2O molecules through a transition state (TS) with a small activation barrier (0.22-0.37 eV). From an intermediate state to a TS, H(+) can obtain a kinetic energy of ∼0.95-3.68 eV, due to the Coulomb electric interaction, and easily overcome the activation energy barrier during the WFR. The full catalytic reaction cycles can be completed energetically, and N-C60 fullerene recovers to its original structure for the next catalytic reaction cycle. N-C60 fullerene is a potential cathode catalyst for hydrogen fuel cells.

Dynamics-A explorer RIMS data analysis

NASA Technical Reports Server (NTRS)

Banks, P. M.; Clauer, C. R.

1985-01-01

Activities of the RIMS instrument during the extended mission are planned. The modes of operation for RIMS to achieve the science requirements utilizing the new and exciting information on the composition and dynamics of the low energy (0-50eV) ions in the Earth's ionosphere and magnetosphere are determined. The specific science problems and the required RIMS operational modes needed to acquire the desired data are identified. The analysis was performed on the RIMS data to achieve the science results and this new information was used in determining RIMS operations during the latter part of the mission. Necessary sensitivity tests of RIMS operating modes and instrument performance was suggested. The inflight results was compared with theoretical models.

Clinical Characterization of Children Presenting to the Hospital with Enterovirus D68 Infection During the 2014 Outbreak in St. Louis

PubMed Central

Orvedahl, Anthony; Padhye, Amruta; Barton, Kevin; O’Bryan, Kevin; Baty, Jack; Gruchala, Nancy; Niesen, Angela; Margoni, Angeliki; Srinivasan, Mythili

2016-01-01

Background The largest known outbreak of enterovirus D68 (EV-D68) infections occurred during 2014. The goal of our study is to characterize the illness severity and clinical presentation of children infected with enterovirus-D68 (EV-D68) in comparison to non-EV-D68-Human Rhino/Enteroviruses (HR/EV). Method Our study is a retrospective analysis of severity level, charges and length of stay of children who presented to St. Louis Children’s Hospital from 8/31/2014–10/31/2014 and tested positive for EV-D68 in comparison to non-EV-D68-HR/EV infected patients. Chart review was performed for all EV-D68 infected patients and age and severity matched non-EV-D68-HR/EV infected patients. Result There was a striking increase in hospital census in August of 2014 in our hospital with simultaneous increase in the number of patients with EV-D68 infection. There was no significant difference in severity of illness, length of stay or total charges between EV-D68 and non-EV-D68-HR/EV infected children. EV-D68 infection was characterized by presenting complaints of difficulty breathing (80%) and wheezing (67%), and by findings of tachypnea (65%), wheezing (71%) and retractions (65%) on examination. The most common interventions were albuterol (79%) and corticosteroid (68%) treatments and the most common discharge diagnosis was asthma exacerbation (55%). Conclusion EV-D68 caused a significant outbreak in 2014 with increased hospital admissions and associated increased charges. There was no significant difference in severity of illness caused by EV-D68 and non-EV-D68-HR/EV infections suggesting that the impact from EV-D68 was due to increased number of infected children presenting to the hospital and not necessarily due to increased severity of illness. PMID:26771663

Fluorescence triggering: A general strategy for enumerating and phenotyping extracellular vesicles by flow cytometry.

PubMed

Arraud, Nicolas; Gounou, Céline; Turpin, Delphine; Brisson, Alain R

2016-02-01

Plasma contains cell-derived extracellular vesicles (EVs) which participate in various physiopathological processes and have potential biomedical applications. Despite intense research activity, knowledge on EVs is limited mainly due to the difficulty of isolating and characterizing sub-micrometer particles like EVs. We have recently reported that a simple flow cytometry (FCM) approach based on triggering the detection on a fluorescence signal enabled the detection of 50× more Annexin-A5 binding EVs (Anx5+ EVs) in plasma than the conventional FCM approach based on light scattering triggering. Here, we present the application of the fluorescence triggering approach to the enumeration and phenotyping of EVs from platelet free plasma (PFP), focusing on CD41+ and CD235a+ EVs, as well as their sub-populations which bind or do not bind Anx5. Higher EV concentrations were detected by fluorescence triggering as compared to light scattering triggering, namely 40× for Anx5+ EVs, 75× for CD41+ EVs, and 15× for CD235a+ EVs. We found that about 30% of Anx5+ EVs were of platelet origin while only 3% of them were of erythrocyte origin. In addition, a majority of EVs from platelet and erythrocyte origin do not expose PS, in contrast to the classical theory of EV formation. Furthermore, the same PFP samples were analyzed fresh and after freeze-thawing, showing that freeze-thawing processes induce an increase, of about 35%, in the amount of Anx5+ EVs, while the other EV phenotypes remain unchanged. The method of EV detection and phenotyping by fluorescence triggering is simple, sensitive and reliable. We foresee that its application to EV studies will improve our understanding on the formation mechanisms and functions of EVs in health and disease and help the development of EV-based biomarkers. © 2015 International Society for Advancement of Cytometry.

Selenization of Cu2ZnSnS4 Enhanced the Performance of Dye-Sensitized Solar Cells: Improved Zinc-Site Catalytic Activity for I3.

PubMed

Wang, Xiuwen; Xie, Ying; Bateer, Buhe; Pan, Kai; Jiao, Yanqing; Xiong, Ni; Wang, Song; Fu, Honggang

2017-11-01

Cu 2 ZnSnS 4 (CZTS) and Cu 2 ZnSn(S,Se) 4 (CZTSSe) as promising photovoltaic materials have drawn much attention because they are environmentally benign and earth-abundant elements. In this work, the monodispersed, low-cost Cu 2 ZnSnS 4 nanocrystals with small size have been controllably synthesized via a wet chemical routine. And CZTSSe could be easily prepared after selenization of CZTS. When they are employed as counter electrodes (CEs) for dye-sensitized solar cells (DSSCs), the power conversion efficiency (PCE) has been improved from 3.54% to 7.13% as CZTS is converted to CZTSSe, which is also compared to that of Pt (7.62%). The exact reason for the enhanced catalytic activity of I 3 - is discussed with the work function and density functional theory (DFT) when CZTSSe converted from CZTS. The results of a Kelvin probe suggest that the work function of CZTSSe (5.61 eV) is closer to that of Pt (5.65 eV) and higher than that of CZTS, which matched the redox shuttle potential better. According to the theory calculation, all the atomic and bond populations changed significantly when Se replaced partly the S on the CZTS system, especially in the Zn site. During the catalytic process as CEs, the adsorption energy obviously increased compared to those at other sites when I 3 - adsorbed on the Zn site in CZTSSe. So, Zn plays an important role for the reduction of I 3 - after CZTS is converted to CZTSSe. Based on above analysis, the reason for enhanced performance of DSSCs when CZTS converted to CZTSSe is mainly due to the enhancement of Zn-site activity. This work is beneficial for understanding the catalytic reaction mechanism of CZTS(Se) as CEs of DSSCs.

Electronic characterization of defects in narrow gap semiconductors

NASA Technical Reports Server (NTRS)

Patterson, James D.

1994-01-01

We use a Green's function technique to calculate the position of deep defects in narrow gap semiconductors. We consider substitutional (including antisite), vacancy, and interstitial (self and foreign) deep defects. We also use perturbation theory to look at the effect of nonparabolic bands on shallow defect energies and find nonparabolicity can increase the binding by 10 percent or so. We consider mercury cadmium telluride (MCT), mercury zinc telluride (MZT), and mercury zinc selenide (MZS). For substitutional and interstitial defects we look at the situation with and without relaxation. For substitutional impurities in MCT, MZT, and MZS, we consider x (the concentration of Cd or Zn) in the range 0.1 less than x less than 0.3 and also consider appropriate x so E(sub g) = 0.1 eV for each of the three compounds. We consider several cation site s-like deep levels and anion site p-like levels. For E(sub g) = 0.1 eV, we also consider the effects of relaxation. Similar comments apply to the interstitial deep levels whereas no relaxation is considered for the ideal vacancy model. Relaxation effects can be greater for the interstitial than the substitutional cases. Specific results are given in figures and tables and comparison to experiment is made in a limited number of cases. We find, for example, that I, Se, S, Rn, and N are possible cation site, s-like deep levels in MCT and Zn and Mg are for anion site, p-like levels (both levels for substitutional cases). The corresponding cation and anion site levels for interstitial deep defects are (Au, Ag, Hg, Cd, Cu, Zn) and (N, Ar, O, F). For the substitutional cases we have some examples of relaxation moving the levels into the band gap, whereas for the interstitial case we have examples where relaxation moves it out of the band gap. Future work involves calculating the effects of charge state interaction and seeing the effect of relaxation on vacancy levels.

First-principles calculations of nitrogen-doped antimony triselenide: A prospective material for solar cells and infrared optoelectronic devices

NASA Astrophysics Data System (ADS)

Sajid-ur-Rehman; Butt, Faheem K.; Li, Chuanbo; Ul Haq, Bakhtiar; Tariq, Zeeshan; Aleem, F.

2018-06-01

This study is focused on calculation of the electronic structure and optical properties of non-metal doped Sb2Se3 using the first-principles method. One and two N atoms are introduced to Sb and Se sites in a Sb2Se3 crystal. When one and two N atoms are introduced into the Sb2Se3 lattice at Sb sites, the electronic structure shows that the doping significantly modifies the bandgap of Sb2Se3 from 1.11 eV to 0.787 and 0.685 eV, respectively. When N atoms are introduced to Se sites, the material shows a metallic behavior. The static dielectric constants ɛ1(0) for Sb16Se24, Sb15N1Se24, Sb14N2Se24, Sb16Se23N1, and Sb16Se22N2 are 14.84, 15.54, 15.02, 18.9, and 39.29, respectively. The calculated values of the refractive index n(0) for Sb16Se24, Sb15N1Se24, Sb14N2Se24, Sb16Se23N1, and Sb16Se22N2 are 3.83, 3.92, 3.86, 4.33, and 6.21, respectively. The optical absorbance and optical conductivity curves of the crystal for N-doping at Sb sites show a significant redshift towards the short-wave infrared spectral region as compared to N-doping at Se sites. The modulation of the static refractive index and static dielectric constant is mainly dependent on the doping level. The optical properties and bandgap narrowing effect suggest that the N-doped Sb2Se3is a promising new semiconductor and can be a replacement for GaSb due to its very similar bandgap and low cost.

Isolation and Characterization of Extracellular Vesicles from Adult Schistosoma japonicum.

PubMed

Liu, Juntao; Zhu, Lihui; Wang, Lihui; Chen, Yongjun; Giri, Bikash Ranjan; Li, Jianjun; Cheng, Guofeng

2018-05-22

Extracellular vesicles (EVs) are membranous vesicles released by a variety of cells into the extracellular microenvironment. EVs represent a population of heterogeneous vesicles, whose size range between 40 and 1,000 nm. Accumulated evidence indicated that EVs play important regulatory roles in pathogen-host interactions. A deep understanding of schistosome EVs should provide insights into the mechanisms underlying schistosome-host interactions, enabling development of novel strategies against schistosomiasis. Here, we aim to further study EVs functions in schistosomes by presenting a protocol for the isolation and characterization of EVs from adult Schistosoma japonicum (S. japonicum). EVs were isolated from in vitro culture medium using centrifugation combined with a commercial exosome isolation kit. The isolated S. japonicum EVs (SjEVs) typically possess a diameter of 100 - 400 nm, and are characterized by transmission electronic microscopy and western blotting. The usage of PKH67 dye-labeled SjEVs has demonstrated that SjEVs are internalized by the recipient cells. Overall, our protocol provides an alternative method for isolating EVs from adult schistosomes; the isolated SjEVs may be suitable for functional analysis.

A new bioluminescent reporter system to study the biodistribution of systematically injected tumor-derived bioluminescent extracellular vesicles in mice

PubMed Central

Gangadaran, Prakash; Li, Xiu Juan; Lee, Ho Won; Oh, Ji Min; Kalimuthu, Senthilkumar; Rajendran, Ramya Lakshmi; Son, Seung Hyun; Baek, Se Hwan; Singh, Thoudam Debraj; Zhu, Liya; Jeong, Shin Young; Lee, Sang-Woo; Lee, Jaetae; Ahn, Byeong-Cheol

2017-01-01

In vivo biodistribution and fate of extracellular vesicles (EVs) are still largely unknown and require reliable in vivo tracking techniques. In this study, in vivo bioluminescence imaging (BLI) using Renilla luciferase (Rluc) was developed and applied to monitoring of EVs derived from thyroid cancer (CAL-62 cells) and breast cancer (MDA-MB-231) in nude mice after intravenous administration and was compared with a dye-based labeling method for EV derived from CAL-62 cells. The EVs were successfully labeled with Rluc and visualized by BLI in mice. In vivo distribution of the EVs, as measured by BLI, was consistent with the results of ex vivo organ analysis. EV-CAL-62/Rluc showed strong signals at lung followed by liver, spleen & kidney (P < 0.05). EV-MDA-MB-231/Rluc showed strong signals at liver followed by lung, spleen & kidney (P < 0.05). EV-CAL-62/Rluc and EV-MDA-MB-231/Rluc stayed in animal till day 9 and 3, respectively; showed a differential distribution. Spontaneous EV-CAL-62/Rluc shown distributed mostly to lung followed by liver, spleen & kidney. The new BLI system used to show spontaneous distribution of EV-CAL-62/Rluc in subcutaneous CAL-62/Rluc bearing mice. Dye (DiR)-labeled EV-CAL-62/Rluc showed a different distribution in vivo & ex vivo compared to EV-CAL-62/Rluc. Fluorescent signals were predominately detected in the liver (P < 0.05) and spleen (P < 0.05) regions. The bioluminescent EVs developed in this study may be used for monitoring of EVs in vivo. This novel reporter-imaging approach to visualization of EVs in real time is expected to pave the way for monitoring of EVs in EV-based treatments. PMID:29299117

MiR-145 detection in urinary extracellular vesicles increase diagnostic efficiency of prostate cancer based on hydrostatic filtration dialysis method.

PubMed

Xu, Yong; Qin, Sihua; An, Taixue; Tang, Yueting; Huang, Yiyao; Zheng, Lei

2017-07-01

Extracellular vesicles (EVs) can be detected in body fluids and may serve as disease biomarkers. Increasing evidence suggests that circulating miRNAs in serum and urine may be potential non-invasive biomarkers for prostate cancer (PCa). In the present study, we aimed to investigate whether hydrostatic filtration dialysis (HFD) is suitable for urinary EVs (UEVs) isolation and whether such reported PCa-related miRNAs can be detected in UEVs as PCa biomarkers. To analyze EVs miRNAs, we searched for an easy and economic method to enrich EVs from urine samples. We compared the efficiency of HFD method and conventional ultracentrifugation (UC) in isolating UEVs. Subsequently, UEVs were isolated from patients with PCa, patients with benign prostate hyperplasia (BPH) and healthy individuals. Differential expression of four PCa-related miRNAs (miR-572, miR-1290, miR-141, and miR-145) were measured in UEVs and paired serum EVs using SYBR Green-based quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The overall performance of HFD was similar to UC. In miRNA yield, both HFD and UC can meet the needs of further analysis. The level of miR-145 in UEVs was significantly increased in patients with PCa compared with the patients with BPH (P = 0.018). In addition, significant increase was observed in miR-145 levels when patients with Gleason score ≥8 tumors compared with Gleason score ≤7 (P = 0.020). Receiver-operating characteristic curve (ROC) revealed that miR-145 in UEVs combined with serum PSA could differentiate PCa from BPH better than PSA alone (AUC 0.863 and AUC 0.805, respectively). In serum EVs, four miRNAs were significantly higher in patients with PCa than with BPH. HFD is appropriate for UEVs isolation and miRNA analysis when compared with conventional UC. miR-145 in UEVs is upregulated from PCa patients compared BPH patients and healthy controls. We suggest the potential use of UEVs miR-145 as a biomarker of PCa. © 2017 Wiley Periodicals, Inc.

Immunoaffinity based methods are superior to kits for purification of prostate derived extracellular vesicles from plasma samples.

PubMed

Brett, Sabine I; Lucien, Fabrice; Guo, Charles; Williams, Karla C; Kim, Yohan; Durfee, Paul N; Brinker, C J; Chin, Joseph I; Yang, Jun; Leong, Hon S

2017-05-01

The ability to isolate extracellular vesicles (EVs) such as exosomes or microparticles is an important method that is currently not standardized. While commercially available kits offer purification of EVs from biofluids, such purified EV samples will also contain non-EV entities such as soluble protein and nucleic acids that could confound subsequent experimentation. Ideally, only EVs would be isolated and no soluble protein would be present in the final EV preparation. We compared commercially available EV isolation kits with immunoaffinity purification techniques and evaluated our final EV preparations using atomic force microscopy (AFM) and nanoscale flow cytometry (NFC). AFM is the only modality capable of detecting distinguishing soluble protein from EVs which is important for downstream proteomics approaches. NFC is the only technique capable of quantitating the proportion of target EVs to non-target EVs in the final EV preparation. To determine enrichment of prostate derived EVs relative to non-target MPs, anti-PSMA (Prostate Specific Membrane Antigen) antibodies were used in NFC. Antibody-based immunoaffinity purification generated the highest quality of prostate derived EV preparations due to the lack of protein and RNA present in the samples. All kits produced poor purity EV preparations that failed to deplete the sample of plasma protein. While attractive due to their ease of use, EV purification kits do not provide substantial improvements in isolation of EVs from biofluids such as plasma. Immunoaffinity approaches are more efficient and economical and will also eliminate a significant portion of plasma proteins which is necessary for downstream approaches. © 2017 Wiley Periodicals, Inc.

A Novel Recombinant Enterovirus Type EV-A89 with Low Epidemic Strength in Xinjiang, China

PubMed Central

Fan, Qin; Zhang, Yong; Hu, Lan; Sun, Qiang; Cui, Hui; Yan, Dongmei; Sikandaner, Huerxidan; Tang, Haishu; Wang, Dongyan; Zhu, Zhen; Zhu, Shuangli; Xu, Wenbo

2015-01-01

Enterovirus A89 (EV-A89) is a novel member of the EV-A species. To date, only one full-length genome sequence (the prototype strain) has been published. Here, we report the molecular identification and genomic characterization of a Chinese EV-A89 strain, KSYPH-TRMH22F/XJ/CHN/2011, isolated in 2011 from a contact of an acute flaccid paralysis (AFP) patient during AFP case surveillance in Xinjiang China. This was the first report of EV-A89 in China. The VP1 coding sequence of this strain demonstrated 93.2% nucleotide and 99.3% amino acid identity with the EV-A89 prototype strain. In the P2 and P3 regions, the Chinese EV-A89 strain demonstrated markedly higher identity than the prototype strains of EV-A76, EV-A90, and EV-A91, indicating that one or more recombination events between EV-A89 and these EV-A types might have occurred. Long-term evolution of these EV types originated from the same ancestor provides the spatial and temporal circumstances for recombination to occur. An antibody sero-prevalence survey against EV-A89 in two Xinjiang prefectures demonstrated low positive rates and low titres of EV-A89 neutralization antibody, suggesting limited range of transmission and exposure to the population. This study provides a solid foundation for further studies on the biological and pathogenic properties of EV-A89. PMID:26685900

Enterovirus infections in hospitals of Ile de France region over 2013.

PubMed

Molet, Lucie; Saloum, Kenda; Marque-Juillet, Stéphanie; Garbarg-Chenon, Antoine; Henquell, Cécile; Schuffenecker, Isabelle; Peigue-Lafeuille, Hélène; Rozenberg, Flore; Mirand, Audrey

2016-01-01

The monitoring and genotyping of Enterovirus (EV) infections can help to associate particular or severe clinical manifestations with specific EV types and to identify the aetiology of infectious outbreaks. To describe the epidemiological features of EV infections diagnosed during the year 2013 in the Greater Paris area (Ile de France). During 2013, 2497 samples taken from 470 patients in 33 hospitals of Ile-de France were tested for EV genome by RT-PCR. EV genotyping was performed by the National Reference Centre (NRC) laboratories. EV infections were retrospectively reviewed by retrieving clinical and genotyping data from the NRC database. Of the 2497 samples, 490 (19.6%) was positive for EV genome detection. These EV infections represented 88.7% and 24.1%, respectively, of all reported regional and national infections. Twenty-seven different genotypes were identified. Echovirus 30 (E-30) accounted for 54.1% of all characterized strains and caused a large outbreak. Four severe neonatal infections were reported, of which two were caused by EV-A71. Respiratory infections involving EV-D68 were observed in two adults. One fatal case of Coxsackievirus A2-associated myocarditis was reported. Monitoring EV infections in combination with EV genotyping via the French EV network characterized the epidemiology of EV infections in the Ile de France region in 2013 and documented severe EV infections associated with EV-A71 or CV-A2. Copyright © 2015 Elsevier B.V. All rights reserved.

A Novel Recombinant Enterovirus Type EV-A89 with Low Epidemic Strength in Xinjiang, China.

PubMed

Fan, Qin; Zhang, Yong; Hu, Lan; Sun, Qiang; Cui, Hui; Yan, Dongmei; Sikandaner, Huerxidan; Tang, Haishu; Wang, Dongyan; Zhu, Zhen; Zhu, Shuangli; Xu, Wenbo

2015-12-21

Enterovirus A89 (EV-A89) is a novel member of the EV-A species. To date, only one full-length genome sequence (the prototype strain) has been published. Here, we report the molecular identification and genomic characterization of a Chinese EV-A89 strain, KSYPH-TRMH22F/XJ/CHN/2011, isolated in 2011 from a contact of an acute flaccid paralysis (AFP) patient during AFP case surveillance in Xinjiang China. This was the first report of EV-A89 in China. The VP1 coding sequence of this strain demonstrated 93.2% nucleotide and 99.3% amino acid identity with the EV-A89 prototype strain. In the P2 and P3 regions, the Chinese EV-A89 strain demonstrated markedly higher identity than the prototype strains of EV-A76, EV-A90, and EV-A91, indicating that one or more recombination events between EV-A89 and these EV-A types might have occurred. Long-term evolution of these EV types originated from the same ancestor provides the spatial and temporal circumstances for recombination to occur. An antibody sero-prevalence survey against EV-A89 in two Xinjiang prefectures demonstrated low positive rates and low titres of EV-A89 neutralization antibody, suggesting limited range of transmission and exposure to the population. This study provides a solid foundation for further studies on the biological and pathogenic properties of EV-A89.

Enterovirus D68 and other enterovirus serotypes identified in South African patients with severe acute respiratory illness, 2009-2011.

PubMed

Hellferscee, Orienka; Treurnicht, Florette K; Tempia, Stefano; Variava, Ebrahim; Dawood, Halima; Kahn, Kathleen; Cohen, Adam L; Pretorius, Marthi; Cohen, Cheryl; Madhi, Shabir A; Venter, Marietjie

2017-05-01

Human enteroviruses (EV) have been associated with severe acute respiratory illness (SARI) in South Africa. We aimed to describe the molecular epidemiology of EV serotypes among patients hospitalized with SARI during 2009-2011. Study samples from patients were tested for the presence of enterovirus using a polymerase chain reaction assay. 8.2% (842/10 260) of SARI cases tested positive for enterovirus; 16% (7/45) were species EV-A, 44% (20/45) EV-B, 18% (8/45) EV-C and 22% (10/45) EV-D. Seventeen different EV serotypes were identified within EV-A to EV-D, of which EV-D68 (22%; 10/45) and Echovirus 3 (11%; 5/45) were the most prevalent. EV-D68 should be monitored in South Africa to assess the emergence of highly pathogenic strains. © 2017 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

NREL to Research Revolutionary Battery Storage Approaches in Support of

Science.gov Websites

adoption by dramatically improving driving range and reliability, and by providing low-cost carbon have the potential to meet the demanding safety, cost and performance levels for EVs set by ARPA-E, but materials to develop a new low-cost battery that operates similar to a flow battery, where chemical energy

Recent progress in avalanche photodiodes for sensing in the IR spectrum

NASA Astrophysics Data System (ADS)

Maddox, S. J.; Ren, M.; Woodson, M. E.; Bank, S. R.; Campbell, J. C.

2016-05-01

Abstract—We report low-noise avalanche gain from photodiodes composed of a previously uncharacterized alloy, AlxIn1-xAsySb1-y, grown lattice-matched on GaSb substrates. By varying the aluminum content the direct bandgap can be tuned from 0.25 eV (0% aluminum) to 1.24 eV (75% aluminum), corresponding to photon wavelengths from 5000 nm to 1000 nm, with the transition from direct-gap to indirect-gap occurring at ~1.18 eV (~72% aluminum), or 1050 nm. This has been used to fabricate separate absorption, charge, and multiplication (SACM) APDs using Al0.7In0.3As0.3Sb0.7 for the multiplication region and Al0.4In0.6As0.3Sb0.7 for the absorber. Gain values as high as 100 have been achieved and the excess noise factor is characterized by a k value of 0.01, which is comparable to or below that of Si. In addition, since the bandgap of the absorption region is direct, its absorption depth is 5 to 10 times shorter than indirect-bandgap silicon, potentially enabling significantly higher operating bandwidths.

CdZnTe γ detector for deep inelastic neutron scattering on the VESUVIO spectrometer

NASA Astrophysics Data System (ADS)

Andreani, C.; D'Angelo, A.; Gorini, G.; Imberti, S.; Pietropaolo, A.; Rhodes, N. J.; Schooneveld, E. M.; Senesi, R.; Tardocchi, M.

In this paper it is shown that solid-state cadmium-zinc-telluride (CZT) is a promising photon detector for neutron spectroscopy in a wide energy interval, ranging from thermal ( 25 meV) to epithermal ( 70 eV) neutron energies. In the present study two CZT detectors were tested as part of the inverse-geometry neutron spectrometer VESUVIO operating at the ISIS pulsed neutron source. The response of the CZT detector to photon emission from radiative neutron capture in 238U was determined by biparametric measurements of neutron time of flight and photon energy. The scattering response function F(y) from a Pb sample has been derived using both CZT and conventional 6Li-glass scintillator detectors. The former showed both an improved signal to background ratio and higher efficiency as compared to 6Li glass, allowing us to measure F(y) up to the fourth 238U absorption energy (Er=66.02 eV). Due to the small size of CZT detectors, their use is envisaged in arrays, with high spatial resolution, for neutron-scattering studies at high energy (ω>1 eV) and low wavevector (q <10 Å-1) transfers.

Design and development of low pressure evaporator/condenser unit for water-based adsorption type climate control systems

NASA Astrophysics Data System (ADS)

Venkataramanan, Arjun; Rios Perez, Carlos A.; Hidrovo, Carlos H.

2016-11-01

Electric vehicles (EVs) are the future of clean transportation and driving range is one of the important parameters which dictates its marketability. In order to increase driving range, electrical battery energy consumption should be minimized. Vapor-compression refrigeration systems currently employed in EVs for climate control consume a significant fraction of the battery charge. Thus, by replacing this traditional heating ventilation and air-conditioning system with an adsorption based climate control system one can have the capability of increasing the drive range of EVs.The Advanced Thermo-adsorptive Battery (ATB) for climate control is a water-based adsorption type refrigeration cycle. An essential component of the ATB is a low pressure evaporator/condenser unit (ECU) which facilitates both the evaporation and condensation processes. The thermal design of the ECU relies predominantly on the accurate prediction of evaporation/boiling heat transfer coefficients since the standard correlations for predicting boiling heat transfer coefficients have large uncertainty at the low operating pressures of the ATB. This work describes the design and development of a low pressure ECU as well as the thermal performance of the actual ECU prototype.

Rapid restoration of electric vehicle battery performance while driving at cold temperatures

NASA Astrophysics Data System (ADS)

Zhang, Guangsheng; Ge, Shanhai; Yang, Xiao-Guang; Leng, Yongjun; Marple, Dan; Wang, Chao-Yang

2017-12-01

Electric vehicles (EVs) driven in cold weather experience two major drawbacks of Li-ion batteries: drastic power loss (up to 10-fold at -30 °C) and restriction of regenerative braking at temperatures below 5-10 °C. Both factors greatly reduce cruise range, exacerbating drivers' range anxiety in winter. While preheating the battery before driving is a practice widely adopted to maintain battery power and EV drivability, it is time-consuming (on the order of 40 min) and prohibits instantaneous mobility. Here we reveal a control strategy that can rapidly restore EV battery power and permit full regeneration while driving at temperatures as low as -40 °C. The strategy involves heating the battery internally during regenerative braking and rest periods of driving. We show that this technique fully restores room-temperature battery power and regeneration in 13, 33, 46, 56 and 112 s into uninterrupted driving in 0, -10, -20, -30 and -40 °C environments, respectively. Correspondingly, the strategy significantly increases cruise range of a vehicle operated at cold temperatures, e.g. 49% at -40 °C in simulated US06 driving cycle tests. The present work suggests that smart batteries with embedded sensing/actuation can leapfrog in performance.

Thermal modeling of secondary lithium batteries for electric vehicle/hybrid electric vehicle applications

NASA Astrophysics Data System (ADS)

Al-Hallaj, Said; Selman, J. R.

A major obstacle to the development of commercially successful electric vehicles (EV) or hybrid electric vehicles (HEV) is the lack of a suitably sized battery. Lithium ion batteries are viewed as the solution if only they could be "scaled-up safely", i.e. if thermal management problems could be overcome so the batteries could be designed and manufactured in much larger sizes than the commercially available near-2-Ah cells. Here, we review a novel thermal management system using phase-change material (PCM). A prototype of this PCM-based system is presently being manufactured. A PCM-based system has never been tested before with lithium-ion (Li-ion) batteries and battery packs, although its mode of operation is exceptionally well suited for the cell chemistry of the most common commercially available Li-ion batteries. The thermal management system described here is intended specifically for EV/HEV applications. It has a high potential for providing effective thermal management without introducing moving components. Thereby, the performance of EV/HEV batteries may be improved without complicating the system design and incurring major additional cost, as is the case with "active" cooling systems requiring air or liquid circulation.

Cellular tropism of human enterovirus D species serotypes EV-94, EV-70, and EV-68 in vitro: implications for pathogenesis.

PubMed

Smura, Teemu; Ylipaasto, Petri; Klemola, Päivi; Kaijalainen, Svetlana; Kyllönen, Lauri; Sordi, Valeria; Piemonti, Lorenzo; Roivainen, Merja

2010-11-01

Enterovirus 94 (EV-94) is an enterovirus serotype described recently which, together with EV-68 and EV-70, forms human enterovirus D species. This study investigates the seroprevalences of these three serotypes and their abilities to infect, replicate, and damage cell types considered to be essential for enterovirus-induced diseases. The cell types studied included human leukocyte cell lines, primary endothelial cells, and pancreatic islets. High prevalence of neutralizing antibodies against EV-68 and EV-94 was found in the Finnish population. The virus strains studied had wide leukocyte tropism. EV-94 and EV-68 were able to produce infectious progeny in leukocyte cell lines with monocytic, granulocytic, T-cell, or B-cell characteristics. EV-94 and EV-70 were capable of infecting primary human umbilical vein endothelial cells, whereas EV-68 had only marginal progeny production and did not induce cytopathic effects in these cells. Intriguingly, EV-94 was able to damage pancreatic islet β-cells, to infect, replicate, and cause necrosis in human pancreatic islets, and to induce proinflammatory and chemoattractive cytokine expression in endothelial cells. These results suggest that HEV-D viruses may be more prevalent than has been thought previously, and they provide in vitro evidence that EV-94 may be a potent pathogen and should be considered a potentially diabetogenic enterovirus type. © 2010 Wiley-Liss, Inc.

Shift of Enterovirus species among children in Cameroon--identification of a new enterovirus, EV-A119.

PubMed

Ayukekbong, James; Kabayiza, Jean-Claude; Lindh, Magnus; Nkuo-Akenji, Theresia; Tah, Ferdinand; Bergström, Tomas; Norder, Helene

2013-09-01

Infections caused by human enteroviruses (EVs) are often asymptomatic or mild, although they may cause more severe illnesses as meningitis and acute flaccid paralysis. EVs have globally posed a threat to children, and outbreaks of aseptic meningitis and hand, foot and mouth disease are frequently reported. To identify EV strains circulating among healthy children in a small community in Limbe, Cameroon two years apart. Species and EV types were obtained by partial 5'UTR-VP4 and VP1 sequencing of RNA from stool samples collected in October 2009 and September 2011 from 150 children in Cameroon. In all, 74 children (49%) were infected with 28 different types of EV. There were 29 (54%) infected children in 2009, and 45 (47%) in 2011. There was a significant difference between detected species of EV, with 15 (47%) children infected with EV-A in 2009, and 22 (71%) with EV-B in 2011 (p=0.0001). In 2009, one child was infected by a divergent EV, which was most similar to EV-A90. Based on the complete VP1 sequence, it was shown to be a new EV designated EV-A119. The current study shows a high heterogeneity of circulating EV types among children in Limbe, Cameroon, and a previously not described shift in predominating EV species. Copyright © 2013 Elsevier B.V. All rights reserved.

Large-scale screening and characterization of enteroviruses and kobuviruses infecting pigs in Vietnam

PubMed Central

Van Dung, Nguyen; Anh, Pham Hong; Van Cuong, Nguyen; Hoa, Ngo Thi; Carrique-Mas, Juan; Hien, Vo Be; Sharp, C.; Rabaa, M.; Berto, A.; Campbell, James; Baker, Stephen; Farrar, Jeremy; Woolhouse, Mark E.; Bryant, Juliet E.; Simmonds, Peter

2016-01-01

A recent survey of pigs in Dong Thap province, Vietnam identified a high frequency of enterovirus species G (EV-G) infection (144/198; 72.7 %). Amongst these was a plethora of EV-G types (EV-G1, EV-G6 and four new types EV-G8–EV-G11). To better characterize the genetic diversity of EV-G and investigate the possible existence of further circulating types, we performed a larger-scale study on 484 pig and 45 farm-bred boar faecal samples collected in 2012 and 2014, respectively. All samples from the previous and current studies were also screened for kobuviruses. The overall EV infection frequency remained extremely high (395/484; 81.6 %), but with comparable detection rates and viral loads between healthy and diarrhoeic pigs; this contrasted with less frequent detection of EV-G in boars (4/45; 8.9 %). EV was most frequently detected in pigs ≤ 14 weeks old (∼95 %) and declined in older pigs. Infections with EV-G1 and EV-G6 were most frequent, whilst less commonly detected types included EV-G3, EV-G4 and EV-G8–EV-G11, and five new types (EV-G12–EV-G16). In contrast, kobuvirus infection frequency was significantly higher in diarrhoeic pigs (40.9 versus 27.6 %; P = 0.01). Kobuviruses also showed contrasting epizootiologies and age associations; a higher prevalence was found in boars (42 %) compared with domestic pigs (29 %), with the highest infection frequency amongst pigs >52 weeks old. Although genetically diverse, all kobuviruses identified belonged to the species Aichivirus C. In summary, this study confirms infection with EV-G was endemic in Vietnamese domestic pigs and exhibits high genetic diversity and extensive inter-type recombination. PMID:26653281

Complete coding regions of the prototypes enterovirus B93 and C95: phylogenetic analyses of the P1 and P3 regions of EV-B and EV-C strains.

PubMed

Junttila, N; Lévêque, N; Magnius, L O; Kabue, J P; Muyembe-Tamfum, J J; Maslin, J; Lina, B; Norder, H

2015-03-01

Complete coding regions were sequenced for two new enterovirus genomes: EV-B93 previously identified by VP1 sequencing, derived from a child with acute flaccid paralysis in the Democratic Republic of Congo; and EV-C95 from a French soldier with acute gastroenteritis in Djibouti. The EV-B93 P1 had more than 30% nucleotide divergence from other EV-B types, with highest similarity to E-15 and EV-B80. The P1 nucleotide sequence of EV-C95 was most similar, 71%, to CV-A21. Complete coding regions for the new enteroviruses were compared with those of 135 EV-B and 176 EV-C strains representing all types available in GenBank. When strains from the same outbreak or strains isolated during the same year in the same geographical region were excluded, 27 of the 58 EV-B, and 16 of the 23 EV-C types were represented by more than one sequence. However, for EV-B the P3 sequences formed three clades mainly according to origin or time of isolation, irrespective of type, while for EV-C the P3 sequences segregated mainly according to disease manifestation, with most strains causing paralysis, including polioviruses, forming one clade, and strains causing respiratory illness forming another. There was no intermixing of types between these two clades, apart from two EV-C96 strains. The EV-B P3 sequences had lower inter-clade and higher intra-clade variability as compared to the EV-C sequences, which may explain why inter-clade recombinations are more frequent in EV-B. Further analysis of more isolates may shed light on the role of recombinations in the evolution of EV-B in geographical context. © 2014 Wiley Periodicals, Inc.

Unimolecular reaction energies for polycyclic aromatic hydrocarbon ions.

PubMed

West, Brandi; Rodriguez Castillo, Sarah; Sit, Alicia; Mohamad, Sabria; Lowe, Bethany; Joblin, Christine; Bodi, Andras; Mayer, Paul M

2018-03-07

Imaging photoelectron photoion coincidence spectroscopy was employed to explore the unimolecular dissociation of the ionized polycyclic aromatic hydrocarbons (PAHs) acenaphthylene, fluorene, cyclopenta[d,e,f]phenanthrene, pyrene, perylene, fluoranthene, dibenzo[a,e]pyrene, dibenzo[a,l]pyrene, coronene and corannulene. The primary reaction is always hydrogen atom loss, with the smaller species also exhibiting loss of C 2 H 2 to varying extents. Combined with previous work on smaller PAH ions, trends in the reaction energies (E 0 ) for loss of H from sp 2 -C and sp 3 -C centres, along with hydrocarbon molecule loss were found as a function of the number of carbon atoms in the ionized PAHs ranging in size from naphthalene to coronene. In the case of molecules which possessed at least one sp 3 -C centre, the activation energy for the loss of an H atom from this site was 2.34 eV, with the exception of cyclopenta[d,e,f]phenanthrene (CPP) ions, for which the E 0 was 3.44 ± 0.86 eV due to steric constraints. The hydrogen loss from PAH cations and from their H-loss fragments exhibits two trends, depending on the number of unpaired electrons. For the loss of the first hydrogen atom, the energy is consistently ca. 4.40 eV, while the threshold to lose the second hydrogen atom is much lower at ca. 3.16 eV. The only exception was for the dibenzo[a,l]pyrene cation, which has a unique structure due to steric constraints, resulting in a low H loss reaction energy of 2.85 eV. If C 2 H 2 is lost directly from the precursor cation, the energy required for this dissociation is 4.16 eV. No other fragmentation channels were observed over a large enough sample set for trends to be extrapolated, though data on CH 3 and C 4 H 2 loss obtained in previous studies is included for completeness. The dissociation reactions were also studied by collision induced dissociation after ionization by atmospheric pressure chemical ionization. When modeled with a simple temperature-based theory for the post-collision internal energy distribution, there was reasonable agreement between the two sets of data.

Severe paediatric conditions linked with EV-A71 and EV-D68, France, May to October 2016

PubMed Central

Antona, Denise; Kossorotoff, Manoëlle; Schuffenecker, Isabelle; Mirand, Audrey; Leruez-Ville, Marianne; Bassi, Clément; Aubart, Mélodie; Moulin, Florence; Lévy-Bruhl, Daniel; Henquell, Cécile; Lina, Bruno; Desguerre, Isabelle

2016-01-01

We report 59 cases of severe paediatric conditions linked with enterovirus (EV)-A71 and EV-D68 in France between May and October 2016. Fifty-two children had severe neurological symptoms. EV sequence-based typing for 42 cases revealed EV-A71 in 21 (18 subgenotype C1, detected for the first time in France) and EV-D68 in eight. Clinicians should be encouraged to obtain stool and respiratory specimens from patients presenting with severe neurological disorders for EV detection and characterisation. PMID:27918268

Nano-scale investigations of electric-dipole-layer enhanced field and thermionic emission from high current density cathodes

NASA Astrophysics Data System (ADS)

Vlahos, Vasilios

Cesium iodide coated graphitic fibers and scandate cathodes are two important electron emission technologies. The coated fibers are utilized as field emitters for high power microwave sources. The scandate cathodes are promising thermionic cathode materials for pulsed power vacuum electron devices. This work attempts to understand the fundamental physical and chemical relationships between the atomic structure of the emitting cathode surfaces and the superior emission characteristics of these cathodes. Ab initio computational modeling in conjunction with experimental investigations was performed on coated fiber cathodes to understand the origin of their very low turn on electric field, which can be reduced by as much as ten-fold compared to uncoated fibers. Copious amounts of cesium and oxygen were found co-localized on the fiber, but no iodine was detected on the surface. Additional ab initio studies confirmed that cesium oxide dimers could lower the work function significantly. Surface cesium oxide dipoles are therefore proposed as the source of the observed reduction in the turn on electric field. It is also proposed that emission may be further enhanced by secondary electrons from cesium oxide during operation. Thermal conditioning of the coated cathode may be a mechanism by which surface cesium iodide is converted into cesium oxide, promoting the depletion of iodine by formation of volatile gas. Ab initio modeling was also utilized to investigate the stability and work functions of scandate structures. The work demonstrated that monolayer barium-scandium-oxygen surface structures on tungsten can dramatically lower the work function of the underlying tungsten substrate from 4.6 eV down to 1.16 eV, by the formation of multiple surface dipoles. On the basis of this work, we conclude that high temperature kinetics force conventional dispenser cathodes (barium-oxygen monolayers on tungsten) to operate in a non-equilibrium compositional steady state with higher than optimal work functions of ˜2 eV. We hypothesize that scandium enables the barium-oxygen surface monolayer kinetics to access a more thermodynamically stable phase with reported work functions as low as ˜1.3 eV.

Comparison between Silicon-Carbide and diamond for fast neutron detection at room temperature

NASA Astrophysics Data System (ADS)

Obraztsova, O.; Ottaviani, L.; Klix, A.; Döring, T.; Palais, O.; Lyoussi, A.

2018-01-01

Neutron radiation detector for nuclear reactor applications plays an important role in getting information about the actual neutron yield and reactor environment. Such detector must be able to operate at high temperature (up to 600° C) and high neutron flux levels. It is worth nothing that a detector for industrial environment applications must have fast and stable response over considerable long period of use as well as high energy resolution. Silicon Carbide is one of the most attractive materials for neutron detection. Thanks to its outstanding properties, such as high displacement threshold energy (20-35 eV), wide band gap energy (3.27 eV) and high thermal conductivity (4.9 W/cm·K), SiC can operate in harsh environment (high temperature, high pressure and high radiation level) without additional cooling system. Our previous analyses reveal that SiC detectors, under irradiation and at elevated temperature, respond to neutrons showing consistent counting rates as function of external reverse bias voltages and radiation intensity. The counting-rate of the thermal neutron-induced peak increases with the area of the detector, and appears to be linear with respect to the reactor power. Diamond is another semi-conductor considered as one of most promising materials for radiation detection. Diamond possesses several advantages in comparison to other semiconductors such as a wider band gap (5.5 eV), higher threshold displacement energy (40-50 eV) and thermal conductivity (22 W/cm·K), which leads to low leakage current values and make it more radiation resistant that its competitors. A comparison is proposed between these two semiconductors for the ability and efficiency to detect fast neutrons. For this purpose the deuterium-tritium neutron generator of Technical University of Dresden with 14 MeV neutron output of 1010 n·s-1 is used. In the present work, we interpret the first measurements and results with both 4H-SiC and chemical vapor deposition (CVD) diamond detectors irradiated with 14 MeV neutrons at room temperature.

IGSN e.V.: Registration and Identification Services for Physical Samples in the Digital Universe

NASA Astrophysics Data System (ADS)

Lehnert, K. A.; Klump, J.; Arko, R. A.; Bristol, S.; Buczkowski, B.; Chan, C.; Chan, S.; Conze, R.; Cox, S. J.; Habermann, T.; Hangsterfer, A.; Hsu, L.; Milan, A.; Miller, S. P.; Noren, A. J.; Richard, S. M.; Valentine, D. W.; Whitenack, T.; Wyborn, L. A.; Zaslavsky, I.

2011-12-01

The International Geo Sample Number (IGSN) is a unique identifier for samples and specimens collected from our natural environment. It was developed by the System for Earth Sample Registration SESAR to overcome the problem of ambiguous naming of samples that has limited the ability to share, link, and integrate data for samples across Geoscience data systems. Over the past 5 years, SESAR has made substantial progress in implementing the IGSN for sample and data management, working with Geoscience researchers, Geoinformatics specialists, and sample curators to establish metadata requirements, registration procedures, and best practices for the use of the IGSN. The IGSN is now recognized as the primary solution for sample identification and registration, and supported by a growing user community of investigators, repositories, science programs, and data systems. In order to advance broad disciplinary and international implementation of the IGSN, SESAR organized a meeting of international leaders in Geoscience informatics in 2011 to develop a consensus strategy for the long-term operations of the registry with approaches for sustainable operation, organizational structure, governance, and funding. The group endorsed an internationally unified approach for registration and discovery of physical specimens in the Geosciences, and refined the existing SESAR architecture to become a modular and scalable approach, separating the IGSN Registry from a central Sample Metadata Clearinghouse (SESAR), and introducing 'Local Registration Agents' that provide registration services to specific disciplinary or organizational communities, with tools for metadata submission and management, and metadata archiving. Development and implementation of the new IGSN architecture is underway with funding provided by the US NSF Office of International Science and Engineering. A formal governance structure is being established for the IGSN model, consisting of (a) an international not-for-profit organization, the IGSN e.V. (e.V. = 'Eingetragener Verein', legal status for a registered voluntary association in Germany), that defines the IGSN scope and syntax and maintains the IGSN Handle system, and (b) a Science Advisory Board that guides policies, technology, and best practices of the SESAR Sample Metadata Clearinghouse and Local Registration Agents. The IGSN e.V. is being incorporated in Germany at the GFZ Potsdam, a founding event is planned for the AGU Fall Meeting.

Leishmania infantum Exoproducts Inhibit Human Invariant NKT Cell Expansion and Activation

PubMed Central

Belo, Renata; Santarém, Nuno; Pereira, Cátia; Pérez-Cabezas, Begoña; Macedo, Fátima; Leite-de-Moraes, Maria; Cordeiro-da-Silva, Anabela

2017-01-01

Leishmania infantum is one of the major parasite species associated with visceral leishmaniasis, a severe form of the disease that can become lethal if untreated. This obligate intracellular parasite has developed diverse strategies to escape the host immune response, such as exoproducts (Exo) carrying a wide range of molecules, including parasite virulence factors, which are potentially implicated in early stages of infection. Herein, we report that L. infantum Exo and its two fractions composed of extracellular vesicles (EVs) and vesicle-depleted-exoproducts (VDEs) inhibit human peripheral blood invariant natural killer T (iNKT) cell expansion in response to their specific ligand, the glycolipid α-GalactosylCeramide (α-GalCer), as well as their capacity to promptly produce IL-4 and IFNγ. Using plate-bound CD1d and α-GalCer, we found that Exo, EV, and VDE fractions reduced iNKT cell activation in a dose-dependent manner, suggesting that they prevented α-GalCer presentation by CD1d molecules. This direct effect on CD1d was confirmed by the observation that CD1d:α-GalCer complex formation was impaired in the presence of Exo, EV, and VDE fractions. Furthermore, lipid extracts from the three compounds mimicked the inhibition of iNKT cell activation. These lipid components of L. infantum exoproducts, including EV and VDE fractions, might compete for CD1-binding sites, thus blocking iNKT cell activation. Overall, our results provide evidence for a novel strategy through which L. infantum can evade immune responses of mammalian host cells by preventing iNKT lymphocytes from recognizing glycolipids in a TCR-dependent manner. PMID:28674535

SPod Progress Summary Slides | Science Inventory | US EPA

EPA Pesticide Factsheets

This presentation describes the draft “open source” design package for the SPod fenceline sensor. The SPod is a low cost, solar-powered system that combines wind field and air pollutant concentration measurements to detect emission plumes and help locate the source of emissions. The current design works only in “near-fenceline” applications where localized source emission plumes may be present. The SPod uses data analysis software (described elsewhere) to separate baseline drift from the plume signal of interest. This software is necessary for proper operation of the SPod. Because the SPod is designed to detect source emissions plumes, it is not useful for ambient applications large distances away from sources. The current SPod detects a subset of air pollutants that can be ionized with a 10.6 eV photoionization detector (PID). In the future, other air pollutant sensors may be used. The purpose of this presentation and related postings is to advance design concepts in the low-cost fenceline sensor area with any interested parties. The SPod is a work in progress with continued advances incorporated on an ongoing basis. This document is posted on an EPA share drive along with other information that describes the use operation and limitations of the SPod. These slides summarize the SPod design, purpose, and progress as of June, 2016. These slides will be posted on the EPA SPod Share Site along with design information and other materials that communicat

Radiation-induced amorphization of Ce-doped Mg2Y8(SiO4)6O2 silicate apatite

NASA Astrophysics Data System (ADS)

Zhou, Jianren; Yao, Tiankai; Lian, Jie; Shen, Yiqiang; Dong, Zhili; Lu, Fengyuan

2016-07-01

Ce-doped Mg2Y8(SiO4)6O2 silicate apatite (Ce = 0.05 and 0.5) were irradiated with 1 MeV Kr2+ ion beam irradiation at different temperatures and their radiation response and the cation composition dependence of the radiation-induced amorphization were studied by in situ TEM. The two Ce-doped Mg2Y8(SiO4)6O2 silicate apatites are sensitive to ion beam induced amorphization with a low critical dose (0.096 dpa) at room temperature, and exhibits significantly different radiation tolerance at elevated temperatures. Ce concentration at the apatite AI site plays a critical role in determining the radiation response of this silicate apatite, in which the Ce3+ rich Mg2Y7.5Ce0.5(SiO4)6O2 displays lower amorphization susceptibility than Mg2Y7.95Ce0.05(SiO4)6O2 with a lower Ce3+ occupancy at the AI sites. The critical temperature (Tc) and activation energy (Ea) change from 667.5 ± 33 K and 0.162 eV of Mg2Y7.5Ce0.5(SiO4)6O2 to 963.6 ± 64 K and 0.206 eV of Mg2Y7.95Ce0.05(SiO4)6O2. We demonstrate that the radiation tolerance can be controlled by varying the chemical composition, and enhanced radiation tolerance is achieved by increasing the Ce concentration at the AI site.

Surveillance and laboratory detection for non-polio enteroviruses in the European Union/European Economic Area, 2016

PubMed Central

Harvala, Heli; Jasir, Aftab; Penttinen, Pasi; Pastore Celentano, Lucia; Greco, Donato; Broberg, Eeva

2017-01-01

Enteroviruses (EVs) cause severe outbreaks of respiratory and neurological disease as illustrated by EV-D68 and EV-A71 outbreaks, respectively. We have mapped European laboratory capacity for identification and characterisation of non-polio EVs to improve preparedness to respond to (re)-emerging EVs linked to severe disease. An online questionnaire on non-polio EV surveillance and laboratory detection was submitted to all 30 European Union (EU)/European Economic Area (EEA) countries. Twenty-nine countries responded; 26 conducted laboratory-based non-polio EV surveillance, and 24 included neurological infections in their surveillance. Eleven countries have established specific surveillance for EV-D68 via sentinel influenza surveillance (n = 7), typing EV-positive respiratory samples (n = 10) and/or acute flaccid paralysis surveillance (n = 5). Of 26 countries performing non-polio EV characterisation/typing, 10 further characterised culture-positive EV isolates, whereas the remainder typed PCR-positive but culture-negative samples. Although 19 countries have introduced sequence-based EV typing, seven still rely entirely on virus isolation. Based on 2015 data, six countries typed over 300 specimens mostly by sequencing, whereas 11 countries characterised under 50 EV-positive samples. EV surveillance activity varied between EU/EEA countries, and did not always specifically target patients with neurological and/or respiratory infections. Introduction of sequence-based typing methods is needed throughout the EU/EEA to enhance laboratory capacity for the detection of EVs. PMID:29162204

Surveillance and laboratory detection for non-polio enteroviruses in the European Union/European Economic Area, 2016.

PubMed

Harvala, Heli; Jasir, Aftab; Penttinen, Pasi; Pastore Celentano, Lucia; Greco, Donato; Broberg, Eeva

2017-11-01

Enteroviruses (EVs) cause severe outbreaks of respiratory and neurological disease as illustrated by EV-D68 and EV-A71 outbreaks, respectively. We have mapped European laboratory capacity for identification and characterisation of non-polio EVs to improve preparedness to respond to (re)-emerging EVs linked to severe disease. An online questionnaire on non-polio EV surveillance and laboratory detection was submitted to all 30 European Union (EU)/European Economic Area (EEA) countries. Twenty-nine countries responded; 26 conducted laboratory-based non-polio EV surveillance, and 24 included neurological infections in their surveillance. Eleven countries have established specific surveillance for EV-D68 via sentinel influenza surveillance (n = 7), typing EV-positive respiratory samples (n = 10) and/or acute flaccid paralysis surveillance (n = 5). Of 26 countries performing non-polio EV characterisation/typing, 10 further characterised culture-positive EV isolates, whereas the remainder typed PCR-positive but culture-negative samples. Although 19 countries have introduced sequence-based EV typing, seven still rely entirely on virus isolation. Based on 2015 data, six countries typed over 300 specimens mostly by sequencing, whereas 11 countries characterised under 50 EV-positive samples. EV surveillance activity varied between EU/EEA countries, and did not always specifically target patients with neurological and/or respiratory infections. Introduction of sequence-based typing methods is needed throughout the EU/EEA to enhance laboratory capacity for the detection of EVs.

Update on Controls for Isolation and Quantification Methodology of Extracellular Vesicles Derived from Adipose Tissue Mesenchymal Stem Cells

PubMed Central

Franquesa, Marcella; Hoogduijn, Martin J.; Ripoll, Elia; Luk, Franka; Salih, Mahdi; Betjes, Michiel G. H.; Torras, Juan; Baan, Carla C.; Grinyó, Josep M.; Merino, Ana Maria

2014-01-01

The research field on extracellular vesicles (EV) has rapidly expanded in recent years due to the therapeutic potential of EV. Adipose tissue human mesenchymal stem cells (ASC) may be a suitable source for therapeutic EV. A major limitation in the field is the lack of standardization of the challenging techniques to isolate and characterize EV. The aim of our study was to incorporate new controls for the detection and quantification of EV derived from ASC and to analyze the applicability and limitations of the available techniques. ASC were cultured in medium supplemented with 5% of vesicles-free fetal bovine serum. The EV were isolated from conditioned medium by differential centrifugation with size filtration (0.2 μm). As a control, non-conditioned culture medium was used (control medium). To detect EV, electron microscopy, conventional flow cytometry, and western blot were used. The quantification of the EV was by total protein quantification, ExoELISA immunoassay, and Nanosight. Cytokines and growth factors in the EV samples were measured by multiplex bead array kit. The EV were detected by electron microscope. Total protein measurement was not useful to quantify EV as the control medium showed similar protein contents as the EV samples. The ExoELISA kits had technical troubles and it was not possible to quantify the concentration of exosomes in the samples. The use of Nanosight enabled quantification and size determination of the EV. It is, however, not possible to distinguish protein aggregates from EV with this method. The technologies for quantification and characterization of the EV need to be improved. In addition, we detected protein contaminants in the EV samples, which make it difficult to determine the real effect of EV in experimental models. It will be crucial in the future to optimize design novel methods for purification and characterization of EV. PMID:25374572

High levels of circulating extracellular vesicles with altered expression and function during pregnancy.

PubMed

Nardi, Fabiola da Silva; Michelon, Tatiana Ferreira; Neumann, Jorge; Manvailer, Luis Felipe Santos; Wagner, Bettina; Horn, Peter A; Bicalho, Maria da Graça; Rebmann, Vera

2016-07-01

Extracellular vesicles (EVs) are widely considered important modulators of cell-cell communication and may interact with target cells locally and on a systemic level. Several studies had shown that circulating EVs' levels are increased during pregnancy. However, EVs characteristics, composition and biological functions in pregnancy still need to be clarified. This study aims to determine if circulating EVs during pregnancy are modified regarding levels, markers and cytokine profile as well as their reactivity towards peripheral blood cells. 26 pregnant women (PW) being in the second gestational trimester and 59 non-pregnant women (NPW) were investigated. EVs enrichment was performed by ExoQuick™ or ultracentrifugation; nanoparticle tracking analysis, SDS-PAGE followed by Western Blotting and densitometry, and IFN-γ, IL-10 and TGF-β1 ELISA for EVs characterization; imaging flow cytometry to analyze EVs' uptake by peripheral blood cells and flow cytometry were performed to analyze EVs function regarding induction of caspase-3 activity. Circulating EVs' levels were increased during pregnancy [26.9×10(6)EVs/ml (range: 6.4-46.3); p=0.003] vs NPW [18.9×10(6)EVs/ml (range: 2.5-61.3)]. Importantly, the immunosuppressive TGF-β1 and IL-10 cytokine cargo were increased in EVs of PW even after normalization to 1 million EVs [TGF-β1: 0.25pg/10(6)EVs (range: 0.0-2.0); p<0.0001] and [IL-10: 0.21pg/10(6)EVs (range: 0.0-16.8); p=0.006] vs NPW. Although EVs derived from non-pregnant and pregnant women were taken up by NK cells, the latter exclusively enhanced the caspase-3 activity in CD56(dim) NK cells (8.2±0.9; p=0.02). The qualitative and quantitative pregnancy-related alterations of circulating EVs provide first hints for an immune modulating role of circulating EVs during pregnancy. Copyright © 2016 Elsevier GmbH. All rights reserved.

Extracellular vesicles from mice with alcoholic liver disease carry a distinct protein cargo and induce macrophage activation through heat shock protein 90.

PubMed

Saha, Banishree; Momen-Heravi, Fatemeh; Furi, Istvan; Kodys, Karen; Catalano, Donna; Gangopadhyay, Anwesha; Haraszti, Reka; Satishchandran, Abhishek; Iracheta-Vellve, Arvin; Adejumo, Adeyinka; Shaffer, Scott A; Szabo, Gyongyi

2018-05-01

A salient feature of alcoholic liver disease (ALD) is Kupffer cell (KC) activation and recruitment of inflammatory monocytes and macrophages (MØs). These key cellular events of ALD pathogenesis may be mediated by extracellular vesicles (EVs). EVs transfer biomaterials, including proteins and microRNAs, and have recently emerged as important effectors of intercellular communication. We hypothesized that circulating EVs from mice with ALD have a protein cargo characteristic of the disease and mediate biological effects by activating immune cells. The total number of circulating EVs was increased in mice with ALD compared to pair-fed controls. Mass spectrometric analysis of circulating EVs revealed a distinct signature for proteins involved in inflammatory responses, cellular development, and cellular movement between ALD EVs and control EVs. We also identified uniquely important proteins in ALD EVs that were not present in control EVs. When ALD EVs were injected intravenously into alcohol-naive mice, we found evidence of uptake of ALD EVs in recipient livers in hepatocytes and MØs. Hepatocytes isolated from mice after transfer of ALD EVs, but not control EVs, showed increased monocyte chemoattractant protein 1 mRNA and protein expression, suggesting a biological effect of ALD EVs. Compared to control EV recipient mice, ALD EV recipient mice had increased numbers of F4/80 hi cluster of differentiation 11b (CD11b) lo KCs and increased percentages of tumor necrosis factor alpha-positive/interleukin 12/23-positive (inflammatory/M1) KCs and infiltrating monocytes (F4/80 int CD11b hi ), while the percentage of CD206 + CD163 + (anti-inflammatory/M2) KCs was decreased. In vitro, ALD EVs increased tumor necrosis factor alpha and interleukin-1β production in MØs and reduced CD163 and CD206 expression. We identified heat shock protein 90 in ALD EVs as the mediator of ALD-EV-induced MØ activation. Our study indicates a specific protein signature of ALD EVs and demonstrates a functional role of circulating EVs containing heat shock protein 90 in mediating KC/MØ activation in the liver. (Hepatology 2018;67:1986-2000). © 2017 by the American Association for the Study of Liver Diseases.

Severe paediatric conditions linked with EV-A71 and EV-D68, France, May to October 2016.

PubMed

Antona, Denise; Kossorotoff, Manoëlle; Schuffenecker, Isabelle; Mirand, Audrey; Leruez-Ville, Marianne; Bassi, Clément; Aubart, Mélodie; Moulin, Florence; Lévy-Bruhl, Daniel; Henquell, Cécile; Lina, Bruno; Desguerre, Isabelle

2016-11-17

We report 59 cases of severe paediatric conditions linked with enterovirus (EV)-A71 and EV-D68 in France between May and October 2016. Fifty-two children had severe neurological symptoms. EV sequence-based typing for 42 cases revealed EV-A71 in 21 (18 subgenotype C1, detected for the first time in France) and EV-D68 in eight. Clinicians should be encouraged to obtain stool and respiratory specimens from patients presenting with severe neurological disorders for EV detection and characterisation. This article is copyright of The Authors, 2016.

An Update on in Vivo Imaging of Extracellular Vesicles as Drug Delivery Vehicles

PubMed Central

Gangadaran, Prakash; Hong, Chae Moon; Ahn, Byeong-Cheol

2018-01-01

Extracellular vesicles (EVs) are currently being considered as promising drug delivery vehicles. EVs are naturally occurring vesicles that exhibit many characteristics favorable to serve as drug delivery vehicles. In addition, EVs have inherent properties for treatment of cancers and other diseases. For research and clinical translation of use of EVs as drug delivery vehicles, in vivo tracking of EVs is essential. The latest molecular imaging techniques enable the tracking of EVs in living animals. However, each molecular imaging technique has its certain advantages and limitations for the in vivo imaging of EVs; therefore, understanding the molecular imaging techniques is essential to select the most appropriate imaging technology to achieve the desired imaging goal. In this review, we summarize the characteristics of EVs as drug delivery vehicles and the molecular imaging techniques used in visualizing and monitoring EVs in in vivo environments. Furthermore, we provide a perceptual vision of EVs as drug delivery vehicles and in vivo monitoring of EVs using molecular imaging technologies. PMID:29541030

Crystal and electronic structure of copper sulfides

NASA Astrophysics Data System (ADS)

Lukashev, Pavel

Copper sulfides with different copper concentration exist in mineral form ranging from CuS to Cu2S. Among these, chalcosite Cu 2S, and digenite Cu1.8S were the subject of extensive research for decades mainly because of their use as the absorber in photovoltaic cells. Yet; their electronic structure is poorly understood because their crystal structure is complex. Most of the results published so far report the semiconducting nature of these compounds with the energy band gap being in the range of 0.84 to 1.9 eV. The crystal structure consists of a close-packed lattice of S with mobile Cu occupying various types of interstitial sites with a statistical distribution depending on temperature. In this thesis we present the first computational study of their electronic band structure. Initially, we investigated the simpler antifluorite structure. Both local density approximation (LDA) and self-consistent quasiparticle GW calculations with the full-potential linearized muffin-tin orbital method give a semimetallic band structure. Inspection of the nature of the bands shows that the lowest conduction band is mainly Cu-s-like except right near the center of the Brillouin zone where a Cu-s-like state lies about 1 eV below the valence band maximum. Significantly, in GW calculations, this state shifts up by several 0.1 eV but not sufficiently to open a gap. A random distortion of the Cu atoms from the perfect antifluorite positions is found to break the degeneracy of the d state at the Gamma-point and thus opens up a small gap of about 0.1 eV in LDA. As our next step we constructed supercell models for the cubic and hexagonal phases with the Cu positions determined by a weighted random number generator. The low temperature monoclinic phase was also studied. The computed total energies of these structures follow the same order as the reported phases with increasing temperatures. All these models gave similar small band gaps of order 0.1-0.2 eV. However, their conduction band is now mainly s-like and addition of an expected Cu-s level shift opens the gap to about 0.5 eV. Some simpler hexagonal model structures gave slightly larger band gap but were found to be unrealistic. The optical absorption data all show a strong intraband absorption with a minimum in absorption at about 1 eV. Our calculations suggest a significantly lower gap of order 0.5 eV with low absorption cross section, the true nature of which is masked by the free carrier absorption. As part of our study of the related Cu-compounds, we analyzed the quasiparticle effects beyond LDA obtained from a GW calculation on the effective masses and Kohn-Luttinger hamiltonian parameters for CuBr.

PEGylated and targeted extracellular vesicles display enhanced cell specificity and circulation time.

PubMed

Kooijmans, S A A; Fliervoet, L A L; van der Meel, R; Fens, M H A M; Heijnen, H F G; van Bergen En Henegouwen, P M P; Vader, P; Schiffelers, R M

2016-02-28

Extracellular vesicles (EVs) are increasingly being recognized as candidate drug delivery systems due to their ability to functionally transfer biological cargo between cells. However, the therapeutic applicability of EVs may be limited due to a lack of cell-targeting specificity and rapid clearance of exogenous EVs from the circulation. In order to improve EV characteristics for drug delivery to tumor cells, we have developed a novel method for decorating EVs with targeting ligands conjugated to polyethylene glycol (PEG). Nanobodies specific for the epidermal growth factor receptor (EGFR) were conjugated to phospholipid (DMPE)-PEG derivatives to prepare nanobody-PEG-micelles. When micelles were mixed with EVs derived from Neuro2A cells or platelets, a temperature-dependent transfer of nanobody-PEG-lipids to the EV membranes was observed, indicative of a 'post-insertion' mechanism. This process did not affect EV morphology, size distribution, or protein composition. After introduction of PEG-conjugated control nanobodies to EVs, cellular binding was compromised due to the shielding properties of PEG. However, specific binding to EGFR-overexpressing tumor cells was dramatically increased when EGFR-specific nanobodies were employed. Moreover, whereas unmodified EVs were rapidly cleared from the circulation within 10min after intravenous injection in mice, EVs modified with nanobody-PEG-lipids were still detectable in plasma for longer than 60min post-injection. In conclusion, we propose post-insertion as a novel technique to confer targeting capacity to isolated EVs, circumventing the requirement to modify EV-secreting cells. Importantly, insertion of ligand-conjugated PEG-derivatized phospholipids in EV membranes equips EVs with improved cell specificity and prolonged circulation times, potentially increasing EV accumulation in targeted tissues and improving cargo delivery. Copyright © 2015. Published by Elsevier B.V.

Extracellular vesicles for liquid biopsy in prostate cancer: where are we and where are we headed?

PubMed

Minciacchi, V R; Zijlstra, A; Rubin, M A; Di Vizio, D

2017-09-01

Extracellular vesicles (EVs) are a heterogeneous class of lipid bound particles shed by any cell in the body in physiological and pathological conditions. EVs play critical functions in intercellular communication. EVs can actively travel in intercellular matrices and eventually reach the circulation. They can also be released directly in biological fluids where they appear to be stable. Because the molecular content of EVs reflects the composition of the cell of origin, they have recently emerged as a promising source of biomarkers in a number of diseases. EV analysis is particularly attractive in cancer patients that frequently present with increased numbers of circulating EVs. We sought to review the current literature on the molecular profile of prostate cancer-derived EVs in model systems and patient biological fluids in an attempt to draw some practical and universal conclusions on the use of EVs as a tool for liquid biopsy in clinical specimens. We discuss advantages and limitations of EV-based liquid biopsy approaches summarizing salient studies on protein, DNA and RNA. Several candidate biomarkers have been identified so far but these results are difficult to apply to the clinic. However, the field is rapidly moving toward the implementation of novel tools to isolate cancer-specific EVs that are free of benign EVs and extra-vesicular contaminants. This can be achieved by identifying markers that are exquisitely present in tumor cell-derived EVs. An important contribution might also derive from a better understanding of EV types that may play specific functions in tumor progression and that may be a source of cancer-specific markers. EV analysis holds strong promises for the development of non-invasive biomarkers in patients with prostate cancer. Implementation of modern methods for EV isolation and characterization will enable to interrogate circulating EVs in vivo.

Prediction of esophageal variceal bleeding in B-viral liver cirrhosis using the P2/MS noninvasive index based on complete blood counts.

PubMed

Kim, Beom Kyung; Ahn, Sang Hoon; Han, Kwang-Hyub; Park, Jun Yong; Han, Min Seok; Jo, Jung Hyun; Kim, Ja Kyung; Lee, Kwan Sik; Chon, Chae Yoon; Kim, Do Young

2012-01-01

Periodic endoscopy for esophageal varices (EVs) and prophylactic treatment of high-risk EVs, i.e., medium/large EVs, small EVs with the red-color sign or decompensation, are recommended in cirrhotic patients. We assessed the cumulative risks for future EV bleeding using the following simple P2/MS index: (platelet count)2/[monocyte fraction (%) × segmented neutrophil fraction (%)]. We enrolled 475 consecutive B-viral cirrhosis patients for 4 years, none of whom experienced EV bleeding. All underwent laboratory work-ups, endoscopy and ultrasonography. Those with EV bleeding took a nonselective β-blocker as prophylaxis. The major endpoint was the first occurrence of EV bleeding, analyzed using the Kaplan-Meier and Cox regression methods. Among patients with EV bleeding (n = 131), 25 experienced their first EV bleeding during follow-up. To differentiate the risk for EV bleeding, we divided them into two subgroups according to their P2/MS value (subgroup 1: P2/MS ≥9 and subgroup 2: P2/MS <9). The risk was significantly higher in subgroup 2 (p = 0.029). From multivariate analysis, a lower P2/MS (p = 0.040) remained a significant predictor for EV bleeding along with large varix size (p = 0.015), red-color sign (p = 0.041) and Child-Pugh classification B/C (p = 0.001). In subgroup 1, the risk for EV bleeding was similar to that of patients with low-risk EVs (p = 0.164). The P2/MS is a reliable predictor for the risk of EV bleeding among patients with EV bleeding. According to risk stratification, different prophylactic treatments should be considered for the subgroup with a P2/MS <9. Copyright © 2012 S. Karger AG, Basel.

Study of the characteristics current-voltage and capacitance-voltage in nitride GaAs Schottky diode

NASA Astrophysics Data System (ADS)

Rabehi, Abdelaziz; Amrani, Mohamed; Benamara, Zineb; Akkal, Boudali; Hatem-Kacha, Arslane; Robert-Goumet, Christine; Monier, Guillaume; Gruzza, Bernard

2015-10-01

This article reports the study of Au/GaN/GaAs Schottky diodes, where the thin GaN film is prepared by nitridation of GaAs substrates with thicknesses of 0.7 and 0.8 nm. The resulting GaN sample with thickness 0.8 nm is then treated with an annealing operation (heating to 620 °C) to improve the current transport. The current-voltage (I-V) and capacitance-voltage (C-V) of the Au/GaN/GaAs structures were investigated at room temperature. In fact, the I-V characteristics show that the annealed sample has low series resistance (Rs) and ideality factor (n) (63 Ω, 2.27 respectively) when compared to the values obtained in the untreated sample (1.83 kΩ, 3.31 respectively). The formation of the GaN layer on the gallium arsenide surface is investigated through calculation of the interface state density NSS with and without the presence of series resistance Rs. The value of the interface state density NSS(E) close to the mid-gap was estimated to be in the order of 4.7×1012 cm-2 eV-1 and 1.02× 1013 cm-2 eV-1 with and without the annealing operation, respectively. However, nitridation with the annealing operation at 620 °C improves the electrical properties of the resultant Schottky diode.

Interfacial strain effects on lithium diffusion pathways in the spinel solid electrolyte Li-doped MgAl2O4

NASA Astrophysics Data System (ADS)

O'Rourke, Conn; Morgan, Benjamin J.

2018-04-01

The (Li,Al)-codoped magnesium spinel (LixMg1 -2 xAl2 +xO4 ) is a solid lithium-ion electrolyte with potential use in all-solid-state lithium-ion batteries. The spinel structure means that interfaces with spinel electrodes, such as LiyMn2O4 and Li4 +3 zTi5O12 , may be lattice matched, with potentially low interfacial resistances. Small lattice parameter differences across a lattice-matched interface are unavoidable, causing residual epitaxial strain. This strain potentially modifies lithium diffusion near the electrolyte-electrode interface, contributing to interfacial resistance. Here, we report a density functional theory study of strain effects on lithium diffusion pathways for (Li,Al)-codoped magnesium spinel, for xLi=0.25 and xLi=0.5 . We have calculated diffusion profiles for the unstrained materials, and for isotropic and biaxial tensile strains of up to 6 % , corresponding to {100 } epitaxial interfaces with LiyMn2O4 and Li4 +3 zTi5O12 . We find that isotropic tensile strain reduces lithium diffusion barriers by as much as 0.32 eV , with typical barriers reduced by ˜0.1 eV. This effect is associated with increased volumes of transitional octahedral sites, and broadly follows qualitative changes in local electrostatic potentials. For biaxial (epitaxial) strain, which more closely approximates strain at a lattice-matched electrolyte-electrode interface, changes in octahedral site volumes and in lithium diffusion barriers are much smaller than under isotropic strain. Typical barriers are reduced by only ˜0.05 eV. Individual effects, however, depend on the pathway considered and the relative strain orientation. These results predict that isotropic strain strongly affects ionic conductivities in (Li,Al)-codoped magnesium spinel electrolytes, and that tensile strain is a potential route to enhanced lithium transport. For a lattice-matched interface with candidate spinel-structured electrodes, however, epitaxial strain has a small, but complex, effect on lithium diffusion barriers.

Synthesis of new visible light active photocatalysts of Ba(In(1/3)Pb(1/3)M'(1/3))O3 (M' = Nb, Ta): a band gap engineering strategy based on electronegativity of a metal component.

PubMed

Hur, Su Gil; Kim, Tae Woo; Hwang, Seong-Ju; Park, Hyunwoong; Choi, Wonyong; Kim, Sung Jin; Kim, Sun Jin; Choy, Jin-Ho

2005-08-11

We have synthesized new, efficient, visible light active photocatalysts through the incorporation of highly electronegative non-transition metal Pb or Sn ions into the perovskite lattice of Ba(In(1/3)Pb(1/3)M'(1/3))O3 (M = Sn, Pb; M' = Nb, Ta). X-ray diffraction, X-ray absorption spectroscopic, and energy dispersive spectroscopic microprobe analyses reveal that tetravalent Pb or Sn ions exist in the B-site of the perovskite lattice, along with In and Nb/Ta ions. According to diffuse UV-vis spectroscopic analysis, the Pb-containing quaternary metal oxides Ba(In(1/3)Pb(1/3)M'(1/3))O3 possess a much narrower band gap (E(g) approximately 1.48-1.50 eV) when compared to the ternary oxides Ba(In(1/2)M'(1/2))O3 (E(g) approximately 2.97-3.30 eV) and the Sn-containing Ba(In(1/3)Sn(1/3)M'(1/3))O3 derivatives (E(g) approximately 2.85-3.00 eV). Such a variation of band gap energy upon the substitution is attributable to the broadening of the conduction band caused by the dissimilar electronegativities of the B-site cations. In contrast to the ternary or the Sn-substituted quaternary compounds showing photocatalytic activity under UV-vis irradiation, the Ba(In(1/3)Pb(1/3)M'(1/3))O3 compounds induce an efficient photodegradation of 4-chlorophenol under visible light irradiation (lambda > 420 nm). The present results highlight that the substitution of electronegative non-transition metal cations can provide a very powerful way of developing efficient visible light harvesting photocatalysts through tuning of the band structure of a semiconductive metal oxide.

Improved sliced velocity map imaging apparatus optimized for H photofragments.

PubMed

Ryazanov, Mikhail; Reisler, Hanna

2013-04-14

Time-sliced velocity map imaging (SVMI), a high-resolution method for measuring kinetic energy distributions of products in scattering and photodissociation reactions, is challenging to implement for atomic hydrogen products. We describe an ion optics design aimed at achieving SVMI of H fragments in a broad range of kinetic energies (KE), from a fraction of an electronvolt to a few electronvolts. In order to enable consistently thin slicing for any imaged KE range, an additional electrostatic lens is introduced in the drift region for radial magnification control without affecting temporal stretching of the ion cloud. Time slices of ∼5 ns out of a cloud stretched to ⩾50 ns are used. An accelerator region with variable dimensions (using multiple electrodes) is employed for better optimization of radial and temporal space focusing characteristics at each magnification level. The implemented system was successfully tested by recording images of H fragments from the photodissociation of HBr, H2S, and the CH2OH radical, with kinetic energies ranging from <0.4 eV to >3 eV. It demonstrated KE resolution ≲1%-2%, similar to that obtained in traditional velocity map imaging followed by reconstruction, and to KE resolution achieved previously in SVMI of heavier products. We expect it to perform just as well up to at least 6 eV of kinetic energy. The tests showed that numerical simulations of the electric fields and ion trajectories in the system, used for optimization of the design and operating parameters, provide an accurate and reliable description of all aspects of system performance. This offers the advantage of selecting the best operating conditions in each measurement without the need for additional calibration experiments.

A better understanding of POLDER's cloud droplet size retrieval: impact of cloud horizontal inhomogeneity and directional sampling

NASA Astrophysics Data System (ADS)

Shang, H.; Chen, L.; Bréon, F.-M.; Letu, H.; Li, S.; Wang, Z.; Su, L.

2015-07-01

The principles of the Polarization and Directionality of the Earth's Reflectance (POLDER) cloud droplet size retrieval requires that clouds are horizontally homogeneous. Nevertheless, the retrieval is applied by combining all measurements from an area of 150 km × 150 km to compensate for POLDER's insufficient directional sampling. Using the POLDER-like data simulated with the RT3 model, we investigate the impact of cloud horizontal inhomogeneity and directional sampling on the retrieval, and then analyze which spatial resolution is potentially accessible from the measurements. Case studies show that the sub-scale variability in droplet effective radius (CDR) can mislead both the CDR and effective variance (EV) retrievals. Nevertheless, the sub-scale variations in EV and cloud optical thickness (COT) only influence the EV retrievals and not the CDR estimate. In the directional sampling cases studied, the retrieval is accurate using limited observations and is largely independent of random noise. Several improvements have been made to the original POLDER droplet size retrieval. For example, the measurements in the primary rainbow region (137-145°) are used to ensure accurate large droplet (> 15 μm) retrievals and reduce the uncertainties caused by cloud heterogeneity. We apply the improved method using the POLDER global L1B data for June 2008, the new CDR results are compared with the operational CDRs. The comparison show that the operational CDRs tend to be underestimated for large droplets. The reason is that the cloudbow oscillations in the scattering angle region of 145-165° are weak for cloud fields with CDR > 15 μm. Lastly, a sub-scale retrieval case is analyzed, illustrating that a higher resolution, e.g., 42 km × 42 km, can be used when inverting cloud droplet size parameters from POLDER measurements.

Measurement of electron antineutrino oscillation based on 1230 days of operation of the Daya Bay experiment

NASA Astrophysics Data System (ADS)

An, F. P.; Balantekin, A. B.; Band, H. R.; Bishai, M.; Blyth, S.; Cao, D.; Cao, G. F.; Cao, J.; Cen, W. R.; Chan, Y. L.; Chang, J. F.; Chang, L. C.; Chang, Y.; Chen, H. S.; Chen, Q. Y.; Chen, S. M.; Chen, Y. X.; Chen, Y.; Cheng, J.-H.; Cheng, J.; Cheng, Y. P.; Cheng, Z. K.; Cherwinka, J. J.; Chu, M. C.; Chukanov, A.; Cummings, J. P.; de Arcos, J.; Deng, Z. Y.; Ding, X. F.; Ding, Y. Y.; Diwan, M. V.; Dolgareva, M.; Dove, J.; Dwyer, D. A.; Edwards, W. R.; Gill, R.; Gonchar, M.; Gong, G. H.; Gong, H.; Grassi, M.; Gu, W. Q.; Guan, M. Y.; Guo, L.; Guo, X. H.; Guo, Y. H.; Guo, Z.; Hackenburg, R. W.; Han, R.; Hans, S.; He, M.; Heeger, K. M.; Heng, Y. K.; Higuera, A.; Hor, Y. K.; Hsiung, Y. B.; Hu, B. Z.; Hu, T.; Hu, W.; Huang, E. C.; Huang, H. X.; Huang, X. T.; Huber, P.; Huo, W.; Hussain, G.; Jaffe, D. E.; Jaffke, P.; Jen, K. L.; Jetter, S.; Ji, X. P.; Ji, X. L.; Jiao, J. B.; Johnson, R. A.; Jones, D.; Joshi, J.; Kang, L.; Kettell, S. H.; Kohn, S.; Kramer, M.; Kwan, K. K.; Kwok, M. W.; Kwok, T.; Langford, T. J.; Lau, K.; Lebanowski, L.; Lee, J.; Lee, J. H. C.; Lei, R. T.; Leitner, R.; Leung, J. K. C.; Li, C.; Li, D. J.; Li, F.; Li, G. S.; Li, Q. J.; Li, S.; Li, S. C.; Li, W. D.; Li, X. N.; Li, Y. F.; Li, Z. B.; Liang, H.; Lin, C. J.; Lin, G. L.; Lin, S.; Lin, S. K.; Lin, Y.-C.; Ling, J. J.; Link, J. M.; Littenberg, L.; Littlejohn, B. R.; Liu, D. W.; Liu, J. L.; Liu, J. C.; Loh, C. W.; Lu, C.; Lu, H. Q.; Lu, J. S.; Luk, K. B.; Lv, Z.; Ma, Q. M.; Ma, X. Y.; Ma, X. B.; Ma, Y. Q.; Malyshkin, Y.; Martinez Caicedo, D. A.; McDonald, K. T.; McKeown, R. D.; Mitchell, I.; Mooney, M.; Nakajima, Y.; Napolitano, J.; Naumov, D.; Naumova, E.; Ngai, H. Y.; Ning, Z.; Ochoa-Ricoux, J. P.; Olshevskiy, A.; Pan, H.-R.; Park, J.; Patton, S.; Pec, V.; Peng, J. C.; Pinsky, L.; Pun, C. S. J.; Qi, F. Z.; Qi, M.; Qian, X.; Raper, N.; Ren, J.; Rosero, R.; Roskovec, B.; Ruan, X. C.; Steiner, H.; Sun, G. X.; Sun, J. L.; Tang, W.; Taychenachev, D.; Treskov, K.; Tsang, K. V.; Tull, C. E.; Viaux, N.; Viren, B.; Vorobel, V.; Wang, C. H.; Wang, M.; Wang, N. Y.; Wang, R. G.; Wang, W.; Wang, X.; Wang, Y. F.; Wang, Z.; Wang, Z.; Wang, Z. M.; Wei, H. Y.; Wen, L. J.; Whisnant, K.; White, C. G.; Whitehead, L.; Wise, T.; Wong, H. L. H.; Wong, S. C. F.; Worcester, E.; Wu, C.-H.; Wu, Q.; Wu, W. J.; Xia, D. M.; Xia, J. K.; Xing, Z. Z.; Xu, J. Y.; Xu, J. L.; Xu, Y.; Xue, T.; Yang, C. G.; Yang, H.; Yang, L.; Yang, M. S.; Yang, M. T.; Ye, M.; Ye, Z.; Yeh, M.; Young, B. L.; Yu, Z. Y.; Zeng, S.; Zhan, L.; Zhang, C.; Zhang, H. H.; Zhang, J. W.; Zhang, Q. M.; Zhang, X. T.; Zhang, Y. M.; Zhang, Y. X.; Zhang, Y. M.; Zhang, Z. J.; Zhang, Z. Y.; Zhang, Z. P.; Zhao, J.; Zhao, Q. W.; Zhao, Y. B.; Zhong, W. L.; Zhou, L.; Zhou, N.; Zhuang, H. L.; Zou, J. H.; Daya Bay Collaboration

2017-04-01

A measurement of electron antineutrino oscillation by the Daya Bay Reactor Neutrino Experiment is described in detail. Six 2.9-GWth nuclear power reactors of the Daya Bay and Ling Ao nuclear power facilities served as intense sources of ν¯ e 's. Comparison of the ν¯e rate and energy spectrum measured by antineutrino detectors far from the nuclear reactors (˜1500 - 1950 m ) relative to detectors near the reactors (˜350 - 600 m ) allowed a precise measurement of ν¯e disappearance. More than 2.5 million ν¯e inverse beta-decay interactions were observed, based on the combination of 217 days of operation of six antineutrino detectors (December, 2011-July, 2012) with a subsequent 1013 days using the complete configuration of eight detectors (October, 2012-July, 2015). The ν¯e rate observed at the far detectors relative to the near detectors showed a significant deficit, R =0.949 ±0.002 (stat )±0.002 (syst ) . The energy dependence of ν¯e disappearance showed the distinct variation predicted by neutrino oscillation. Analysis using an approximation for the three-flavor oscillation probability yielded the flavor-mixing angle sin22 θ13=0.0841 ±0.0027 (stat )±0.0019 (syst ) and the effective neutrino mass-squared difference of |Δ mee2| =(2.50 ±0.06 (stat )±0.06 (syst ))×10-3 eV2 . Analysis using the exact three-flavor probability found Δ m322=(2.45 ±0.06 (stat )±0.06 (syst ))×10-3 eV2 assuming the normal neutrino mass hierarchy and Δ m322=(-2.56 ±0.06 (stat )±0.06 (syst ))×10-3 eV2 for the inverted hierarchy.

A large area cosmic muon detector located at Ohya stone mine

NASA Technical Reports Server (NTRS)

Nii, N.; Mizutani, K.; Aoki, T.; Kitamura, T.; Mitsui, K.; Matsuno, S.; Muraki, Y.; Ohashi, Y.; Okada, A.; Kamiya, Y.

1985-01-01

The chemical composition of the primary cosmic rays between 10 to the 15th power eV and 10 to the 18th power eV were determined by a Large Area Cosmic Muon Detector located at Ohya stone mine. The experimental aims of Ohya project are; (1) search for the ultra high-energy gamma-rays; (2) search for the GUT monopole created by Big Bang; and (3) search for the muon bundle. A large number of muon chambers were installed at the shallow underground near Nikko (approx. 100 Km north of Tokyo, situated at Ohya-town, Utsunomiya-city). At the surface of the mine, very fast 100 channel scintillation counters were equipped in order to measure the direction of air showers. These air shower arrays were operated at the same time, together with the underground muon chamber.

Performance of Magnetic Penetration Thermometers for X-Ray Astronomy

NASA Technical Reports Server (NTRS)

Nagler, P. C.; Adams, J. S.; Balvin, M. A.; Bandler, S. R.; Denis, K. L.; Hsieh, W. T.; Kelly, D. P.; Porst, J. P.; Sadleir, J. E.; Seidel, G. M.;

Accelerated step-temperature aging of Al/x/Ga/1-x/As heterojunction laser diodes

NASA Technical Reports Server (NTRS)

Kressel, H.; Ettenberg, M.; Ladany, I.

1978-01-01

Double-heterojunction A2(0.3)Ga(0.7)As/Al(0.08)Ga(0.92)As lasers (oxide-striped and Al2O3 facet coated) were subjected to step-temperature aging from 60 to 100 C. The change in threshold current and spontaneous output was monitored at 22 C. The average time required for a 20% pulsed threshold current increase ranges from about 500 h, when operating at 100 C, to about 5000 h at a 70 C ambience. At 22 C, the extrapolated time is about 1 million h. The time needed for a 50% spontaneous emission reduction is of the same order of magnitude. The resulting activation energies are approximately 0.95 eV for laser degradation and approximately 1.1 eV for the spontaneous output decrease

The energy spectrum of cosmic rays above 1017.2 eV measured by the fluorescence detectors of the Telescope Array experiment in seven years

NASA Astrophysics Data System (ADS)

Abbasi, R. U.; Abe, M.; Abu-Zayyad, T.; Allen, M.; Azuma, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; Cheon, B. G.; Chiba, J.; Chikawa, M.; Cho, W. R.; Fujii, T.; Fukushima, M.; Goto, T.; Hanlon, W.; Hayashi, Y.; Hayashida, N.; Hibino, K.; Honda, K.; Ikeda, D.; Inoue, N.; Ishii, T.; Ishimori, R.; Ito, H.; Ivanov, D.; Jui, C. C. H.; Kadota, K.; Kakimoto, F.; Kalashev, O.; Kasahara, K.; Kawai, H.; Kawakami, S.; Kawana, S.; Kawata, K.; Kido, E.; Kim, H. B.; Kim, J. H.; Kim, J. H.; Kitamura, S.; Kitamura, Y.; Kuzmin, V.; Kwon, Y. J.; Lan, J.; Lundquist, J. P.; Machida, K.; Martens, K.; Matsuda, T.; Matsuyama, T.; Matthews, J. N.; Minamino, M.; Mukai, Y.; Myers, I.; Nagasawa, K.; Nagataki, S.; Nakamura, T.; Nonaka, T.; Nozato, A.; Ogio, S.; Ogura, J.; Ohnishi, M.; Ohoka, H.; Oki, K.; Okuda, T.; Ono, M.; Oshima, A.; Ozawa, S.; Park, I. H.; Pshirkov, M. S.; Rodriguez, D. C.; Rubtsov, G.; Ryu, D.; Sagawa, H.; Sakurai, N.; Scott, L. M.; Shah, P. D.; Shibata, F.; Shibata, T.; Shimodaira, H.; Shin, B. K.; Shin, H. S.; Smith, J. D.; Sokolsky, P.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Stroman, T. A.; Suzawa, T.; Takamura, M.; Takeda, M.; Takeishi, R.; Taketa, A.; Takita, M.; Tameda, Y.; Tanaka, H.; Tanaka, K.; Tanaka, M.; Thomas, S. B.; Thomson, G. B.; Tinyakov, P.; Tkachev, I.; Tokuno, H.; Tomida, T.; Troitsky, S.; Tsunesada, Y.; Tsutsumi, K.; Uchihori, Y.; Udo, S.; Urban, F.; Vasiloff, G.; Wong, T.; Yamane, R.; Yamaoka, H.; Yamazaki, K.; Yang, J.; Yashiro, K.; Yoneda, Y.; Yoshida, S.; Yoshii, H.; Zollinger, R.; Zundel, Z.

2016-07-01

The Telescope Array (TA) experiment is the largest detector to observe ultra-high-energy cosmic rays in the northern hemisphere. The fluorescence detectors at two stations of TA are newly constructed and have now completed seven years of steady operation. One advantage of monocular analysis of the fluorescence detectors is a lower energy threshold for cosmic rays than that of other techniques like stereoscopic observations or coincidences with the surface detector array, allowing the measurement of an energy spectrum covering three orders of magnitude in energy. Analyzing data collected during those seven years, we report the energy spectrum of cosmic rays covering a broad range of energies above 1017.2eV measured by the fluorescence detectors and a comparison with previously published results.

High-flux soft x-ray harmonic generation from ionization-shaped few-cycle laser pulses

PubMed Central

Brahms, Christian; Gregory, Andrew; Tisch, John W. G.; Marangos, Jon P.

2018-01-01

Laser-driven high-harmonic generation provides the only demonstrated route to generating stable, tabletop attosecond x-ray pulses but has low flux compared to other x-ray technologies. We show that high-harmonic generation can produce higher photon energies and flux by using higher laser intensities than are typical, strongly ionizing the medium and creating plasma that reshapes the driving laser field. We obtain high harmonics capable of supporting attosecond pulses up to photon energies of 600 eV and a photon flux inside the water window (284 to 540 eV) 10 times higher than previous attosecond sources. We demonstrate that operating in this regime is key for attosecond pulse generation in the x-ray range and will become increasingly important as harmonic generation moves to fields that drive even longer wavelengths. PMID:29756033

Broad-band efficiency calibration of ITER bolometer prototypes using Pt absorbers on SiN membranes.

PubMed

Meister, H; Willmeroth, M; Zhang, D; Gottwald, A; Krumrey, M; Scholze, F

2013-12-01

The energy resolved efficiency of two bolometer detector prototypes for ITER with 4 channels each and absorber thicknesses of 4.5 μm and 12.5 μm, respectively, has been calibrated in a broad spectral range from 1.46 eV up to 25 keV. The calibration in the energy range above 3 eV was performed against previously calibrated silicon photodiodes using monochromatized synchrotron radiation provided by five different beamlines of Physikalische Technische Bundesanstalt at the electron storage rings BESSY II and Metrology Light Source in Berlin. For the measurements in the visible range, a setup was realised using monochromatized halogen lamp radiation and a calibrated laser power meter as reference. The measurements clearly demonstrate that the efficiency of the bolometer prototype detectors in the range from 50 eV up to ≈6 keV is close to unity; at a photon energy of 20 keV the bolometer with the thick absorber detects 80% of the photons, the one with the thin absorber about 50%. This indicates that the detectors will be well capable of measuring the plasma radiation expected from the standard ITER scenario. However, a minimum absorber thickness will be required for the high temperatures in the central plasma. At 11.56 keV, the sharp Pt-L3 absorption edge allowed to cross-check the absorber thickness by fitting the measured efficiency to the theoretically expected absorption of X-rays in a homogeneous Pt-layer. Furthermore, below 50 eV the efficiency first follows the losses due to reflectance expected for Pt, but below 10 eV it is reduced further by a factor of 2 for the thick absorber and a factor of 4 for the thin absorber. Most probably, the different histories in production, storage, and operation led to varying surface conditions and additional loss channels.

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

Cobb, Corie Lynn

The development of mass markets for large-format batteries, including electric vehicles (EVs) and grid support, depends on both cost reductions and performance enhancements to improve their economic viability. Palo Alto Research Center (PARC) has developed a multi-material, advanced manufacturing process called co-extrusion (CoEx) to remove multiple steps in a conventional battery coating process with the potential to simultaneously increase battery energy and power density. CoEx can revolutionize battery manufacturing across most chemistries, significantly lowering end-product cost and shifting the underlying economics to make EVs and other battery applications a reality. PARC’s scale-up of CoEx for electric vehicle (EV) batteries buildsmore » on a solid base of experience in applying CoEx to solar cell manufacturing, deposition of viscous ceramic pastes, and Li-ion battery chemistries. In the solar application, CoEx has been deployed commercially at production scale where multi-channel CoEx printheads are used to print viscous silver gridline pastes at full production speeds (>40 ft/min). This operational scale-up provided invaluable experience with the nuances of speed, yield, and maintenance inherent in taking a new technology to the factory floor. PARC has leveraged this experience, adapting the CoEx process for Lithium-ion (Li-ion) battery manufacturing. To date, PARC has worked with Li-ion battery materials and structured cathodes with high-density Li-ion regions and low-density conduction regions, documenting both energy and power performance. Modeling results for a CoEx cathode show a path towards a 10-20% improvement in capacity for an EV pouch cell. Experimentally, we have realized a co-extruded battery structure with a Lithium Nickel Manganese Cobalt (NMC) cathode at print speeds equivalent to conventional roll coating processes. The heterogeneous CoEx cathode enables improved capacity in thick electrodes at higher C-rates. The proof-of-principle coin cells demonstrate the feasibility of the CoEx technology and a path towards higher energy and higher power EV pouch cells.« less

Comparison of accelerometer cut points for predicting activity intensity in youth.

PubMed

Trost, Stewart G; Loprinzi, Paul D; Moore, Rebecca; Pfeiffer, Karin A

2011-07-01

The absence of comparative validity studies has prevented researchers from reaching consensus regarding the application of intensity-related accelerometer cut points for children and adolescents. This study aimed to evaluate the classification accuracy of five sets of independently developed ActiGraph cut points using energy expenditure, measured by indirect calorimetry, as a criterion reference standard. A total of 206 participants between the ages of 5 and 15 yr completed 12 standardized activity trials. Trials consisted of sedentary activities (lying down, writing, computer game), lifestyle activities (sweeping, laundry, throw and catch, aerobics, basketball), and ambulatory activities (comfortable walk, brisk walk, brisk treadmill walk, running). During each trial, participants wore an ActiGraph GT1M, and V˙O2 was measured breath-by-breath using the Oxycon Mobile portable metabolic system. Physical activity intensity was estimated using five independently developed cut points: Freedson/Trost (FT), Puyau (PU), Treuth (TR), Mattocks (MT), and Evenson (EV). Classification accuracy was evaluated via weighted κ statistics and area under the receiver operating characteristic curve (ROC-AUC). Across all four intensity levels, the EV (κ=0.68) and FT (κ=0.66) cut points exhibited significantly better agreement than TR (κ=0.62), MT (κ=0.54), and PU (κ=0.36). The EV and FT cut points exhibited significantly better classification accuracy for moderate- to vigorous-intensity physical activity (ROC-AUC=0.90) than TR, PU, or MT cut points (ROC-AUC=0.77-0.85). Only the EV cut points provided acceptable classification accuracy for all four levels of physical activity intensity and performed well among children of all ages. The widely applied sedentary cut point of 100 counts per minute exhibited excellent classification accuracy (ROC-AUC=0.90). On the basis of these findings, we recommend that researchers use the EV ActiGraph cut points to estimate time spent in sedentary, light-, moderate-, and vigorous-intensity activity in children and adolescents.

Comfort and exertion while using filtering facepiece respirators with exhalation valve and an active venting system among male military personnel.

PubMed

Seng, Melvin; Wee, Liang En; Zhao, Xiahong; Cook, Alex R; Chia, Sin Eng; Lee, Vernon J

2017-07-06

This study aimed to determine if disposable filtering facepiece respirators (FFRs), with exhalation valve (EV) and a novel active venting system (AVS), provided greater perceived comfort and exertion when compared to standard N95 FFRs without these features among male military personnel performing prolonged essential outdoor duties. We used a randomised open-label controlled crossover study design to compare three FFR options: (a) standard FFR; (b) FFR with EV; and (c) FFR with EV+AVS. Male military personnel aged between 18 and 20 years completed a questionnaire at the beginning (baseline), after two hours of standardised non-strenuous outdoor duty and after 12 hours of duty divided into two-hour work-rest cycles. Participants rated the degree of discomfort, exertion and symptoms using a five-point Likert scale. The association between outcomes and the types of FFR was assessed using a multivariate ordered probit mixed-effects model. For a majority of the symptoms, study participants rated FFR with EV and FFR with EV+AVS with significantly better scores than standard FFR. Both FFR with EV and FFR with EV+AVS had significantly less discomfort (FFR with EV+AVS: 91.1%; FFR with EV: 57.6%) and exertion (FFR with EV+AVS: 83.5%; FFR with EV: 34.4%) than standard FFR. FFR with EV+AVS also had significantly better scores for exertion (53.4%) and comfort (39.4%) when compared to FFR with EV. Usage of FFR with EV+AVS resulted in significantly reduced symptoms, discomfort and exertion when compared to FFR with EV and standard FFR.

A platform for actively loading cargo RNA to elucidate limiting steps in EV-mediated delivery.

PubMed

Hung, Michelle E; Leonard, Joshua N

2016-01-01

Extracellular vesicles (EVs) mediate intercellular communication through transfer of RNA and protein between cells. Thus, understanding how cargo molecules are loaded and delivered by EVs is of central importance for elucidating the biological roles of EVs and developing EV-based therapeutics. While some motifs modulating the loading of biomolecular cargo into EVs have been elucidated, the general rules governing cargo loading and delivery remain poorly understood. To investigate how general biophysical properties impact loading and delivery of RNA by EVs, we developed a platform for actively loading engineered cargo RNAs into EVs. In our system, the MS2 bacteriophage coat protein was fused to EV-associated proteins, and the cognate MS2 stem loop was engineered into cargo RNAs. Using this Targeted and Modular EV Loading (TAMEL) approach, we identified a configuration that substantially enhanced cargo RNA loading (up to 6-fold) into EVs. When applied to vesicles expressing the vesicular stomatitis virus glycoprotein (VSVG) - gesicles - we observed a 40-fold enrichment in cargo RNA loading. While active loading of mRNA-length (>1.5 kb) cargo molecules was possible, active loading was much more efficient for smaller (~0.5 kb) RNA molecules. We next leveraged the TAMEL platform to elucidate the limiting steps in EV-mediated delivery of mRNA and protein to prostate cancer cells, as a model system. Overall, most cargo was rapidly degraded in recipient cells, despite high EV-loading efficiencies and substantial EV uptake by recipient cells. While gesicles were efficiently internalized via a VSVG-mediated mechanism, most cargo molecules were rapidly degraded. Thus, in this model system, inefficient endosomal fusion or escape likely represents a limiting barrier to EV-mediated transfer. Altogether, the TAMEL platform enabled a comparative analysis elucidating a key opportunity for enhancing EV-mediated delivery to prostate cancer cells, and this technology should be of general utility for investigations and applications of EV-mediated transfer in other systems.

Handling and storage of human body fluids for analysis of extracellular vesicles

PubMed Central

Yuana, Yuana; Böing, Anita N.; Grootemaat, Anita E.; van der Pol, Edwin; Hau, Chi M.; Cizmar, Petr; Buhr, Egbert; Sturk, Auguste; Nieuwland, Rienk

2015-01-01

Because procedures of handling and storage of body fluids affect numbers and composition of extracellular vesicles (EVs), standardization is important to ensure reliable and comparable measurements of EVs in a clinical environment. We aimed to develop standard protocols for handling and storage of human body fluids for EV analysis. Conditions such as centrifugation, single freeze–thaw cycle, effect of time delay between blood collection and plasma preparation and storage were investigated. Plasma is the most commonly studied body fluid in EV research. We mainly focused on EVs originating from platelets and erythrocytes and investigated the behaviour of these 2 types of EVs independently as well as in plasma samples of healthy subjects. EVs in urine and saliva were also studied for comparison. All samples were analysed simultaneously before and after freeze–thawing by resistive pulse sensing, nanoparticle tracking analysis, conventional flow cytometry (FCM) and transmission (scanning) electron microscopy. Our main finding is that the effect of centrifugation markedly depends on the cellular origin of EVs. Whereas erythrocyte EVs remain present as single EVs after centrifugation, platelet EVs form aggregates, which affect their measured concentration in plasma. Single erythrocyte and platelet EVs are present mainly in the range of 100–200 nm, far below the lower limit of what can be measured by conventional FCM. Furthermore, the effects of single freeze–thaw cycle, time delay between blood collection and plasma preparation up to 1 hour and storage up to 1 year are insignificant (p>0.05) on the measured concentration and diameter of EVs from erythrocyte and platelet concentrates and EVs in plasma, urine and saliva. In conclusion, in standard protocols for EV studies, centrifugation to isolate EVs from collected body fluids should be avoided. Freezing and storage of collected body fluids, albeit their insignificant effects, should be performed identically for comparative EV studies and to create reliable biorepositories. PMID:26563735

Handling and storage of human body fluids for analysis of extracellular vesicles.

PubMed

Yuana, Yuana; Böing, Anita N; Grootemaat, Anita E; van der Pol, Edwin; Hau, Chi M; Cizmar, Petr; Buhr, Egbert; Sturk, Auguste; Nieuwland, Rienk

2015-01-01

Because procedures of handling and storage of body fluids affect numbers and composition of extracellular vesicles (EVs), standardization is important to ensure reliable and comparable measurements of EVs in a clinical environment. We aimed to develop standard protocols for handling and storage of human body fluids for EV analysis. Conditions such as centrifugation, single freeze-thaw cycle, effect of time delay between blood collection and plasma preparation and storage were investigated. Plasma is the most commonly studied body fluid in EV research. We mainly focused on EVs originating from platelets and erythrocytes and investigated the behaviour of these 2 types of EVs independently as well as in plasma samples of healthy subjects. EVs in urine and saliva were also studied for comparison. All samples were analysed simultaneously before and after freeze-thawing by resistive pulse sensing, nanoparticle tracking analysis, conventional flow cytometry (FCM) and transmission (scanning) electron microscopy. Our main finding is that the effect of centrifugation markedly depends on the cellular origin of EVs. Whereas erythrocyte EVs remain present as single EVs after centrifugation, platelet EVs form aggregates, which affect their measured concentration in plasma. Single erythrocyte and platelet EVs are present mainly in the range of 100-200 nm, far below the lower limit of what can be measured by conventional FCM. Furthermore, the effects of single freeze-thaw cycle, time delay between blood collection and plasma preparation up to 1 hour and storage up to 1 year are insignificant (p>0.05) on the measured concentration and diameter of EVs from erythrocyte and platelet concentrates and EVs in plasma, urine and saliva. In conclusion, in standard protocols for EV studies, centrifugation to isolate EVs from collected body fluids should be avoided. Freezing and storage of collected body fluids, albeit their insignificant effects, should be performed identically for comparative EV studies and to create reliable biorepositories.

Advances in Small Pixel TES-Based X-Ray Microcalorimeter Arrays for Solar Physics and Astrophysics

NASA Technical Reports Server (NTRS)

Bandler, S. R.; Adams, J. S.; Bailey, C. N.; Busch, S. E.; Chervenak, J. A.; Eckart, M. E.; Ewin, A. E.; Finkbeiner, F. M.; Kelley, R. L.; Kelly, D. P.;

Serological detection and analysis of anti-VP1 responses against various enteroviruses (EV) (EV-A, EV-B and EV-C) in Chinese individuals.

PubMed

Gao, Caixia; Ding, Yingying; Zhou, Peng; Feng, Jiaojiao; Qian, Baohua; Lin, Ziyu; Wang, Lili; Wang, Jinhong; Zhao, Chunyan; Li, Xiangyu; Cao, Mingmei; Peng, Heng; Rui, Bing; Pan, Wei

2016-02-26

The overall serological prevalence of EV infections based on ELISA remains unknown. In the present study, the antibody responses against VP1 of the EV-A species (enterovirus 71 (EV71), Coxsackievirus A16 (CA16), Coxsackievirus A5 (CA5) and Coxsackievirus A6 (CA6)), of the EV-B species (Coxsackievirus B3 (CB3)), and of the EV-C species (Poliovirus 1 (PV1)) were detected and analyzed by a NEIBM (novel evolved immunoglobulin-binding molecule)-based ELISA in Shanghai blood donors. The serological prevalence of anti-CB3 VP1 antibodies was demonstrated to show the highest level, with anti-PV1 VP1 antibodies at the second highest level, and anti-CA5, CA6, CA16 and EV71 VP1 antibodies at a comparatively low level. All reactions were significantly correlated at different levels, which were approximately proportional to their sequence similarities. Antibody responses against EV71 VP1 showed obvious differences with responses against other EV-A viruses. Obvious differences in antibody responses between August 2013 and May 2014 were revealed. These findings are the first to describe the detailed information of the serological prevalence of human antibody responses against the VP1 of EV-A, B and C viruses, and could be helpful for understanding of the ubiquity of EV infections and for identifying an effective approach for seroepidemiological surveillance based on ELISA.

[Step Fisher discriminant analysis on severe clinical features of hand foot and mouth disease between enterovirus (EV) 71 and other EV].

PubMed

Ruan, Feng; Tan, Ai-jun; Zhang, Xue-bao; Chen, Xue-qin; Xiao, Song-jian; Ye, Zhong-wen; Wang, Song

2011-07-01

To compare the clinical features of severe hand foot and mouth disease between enterovirus (EV) 71 and other EV to find specific diagnosis index of EV71 severe hand foot and mouth disease. Case definition were adopted from national guideline of hand foot and mouth disease diagnose (Version 2010). Clinical data of severe hand foot and mouth disease came from case history and contents of questionnaire would include the ones between the time of onset and diagnoses being made. EV and EV71, Cox A16 nucleic acid tested were by RT-PCR in stool samples. Clinical features of severe hand foot and mouth disease between EV71 and other EV were compare. There appeared statistical differences between neurologic symptoms such as tremor, myoclonic jerk, listlessness, convulsion and white blood cell counts in CSF (P < 0.05). Results from the step Fisher discriminant analysis showed only tremor and white blood cell had an increase in CSF, with statistically significant differences. The discriminant equation of EV71 was Y = 3.059X(1) + 3.83X(5) - 2.742 and the equation of other EV was Y = 1.634X(1) + 1.623X(5) - 1.693. The specificity of EV71 was 91% and the specificity of other EV was 40%. The increase of clinical features of tremor and white blood cell in CSF could be used as diagnosis index of severe EV71.

Applications of EVA guidelines and design criteria. Volume 3: EVA systems cost model formating

NASA Technical Reports Server (NTRS)

Brown, N. E.

1973-01-01

The development of a model for estimating the impact of manned EVA costs on future payloads is discussed. Basic information on the EV crewman requirements, equipment, physical and operational characteristics, and vehicle interfaces is provided. The cost model is being designed to allow system designers to quantify the impact of EVA on vehicle and payload systems.

78 FR 2797 - Federal Motor Vehicle Safety Standards; Minimum Sound Requirements for Hybrid and Electric Vehicles

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-14

... vehicles when 4.1% of the fleet is HV and EV would be 2790 fewer pedestrian and pedalcyclist injuries. We... Engine Vehicles to Hybrid and Electric Vehicles B. Need for Independent Mobility of People Who Are... requirements for hybrid and electric vehicles when operating under 30 kilometers per hour (km/h) (18 mph), when...

MEANS FOR PRODUCING PLUTONIUM CHAIN REACTIONS

DOEpatents

Wigner, E.P.; Weinberg, A.M.

1961-01-24

A neutronic reactor is described with an active portion capable of operating at an energy level of 0.5 to 1000 ev comprising discrete bodies of Pu/ sup 239/ disposed in a body of water which contains not more than 5 molecules of water to one atom of plutonium, the total amount of Pu/sup 239/ being sufficient to sustain a chain reaction. (auth)

Fast response of sprayed vanadium pentoxide (V2O5) nanorods towards nitrogen dioxide (NO2) gas detection

NASA Astrophysics Data System (ADS)

Mane, A. A.; Suryawanshi, M. P.; Kim, J. H.; Moholkar, A. V.

2017-05-01

The V2O5 nanorods have been successfully spray deposited at optimized substrate temperature of 400 °C onto the glass substrates using vanadium trichloride (VCl3) solution of different concentrations. The effect of solution concentration on the physicochemical and NO2 gas sensing properties of sprayed V2O5 nanorods is studied at different operating temperatures and gas concentrations. The XRD study reveals the formation of V2O5 having an orthorhombic symmetry. The FE-SEM micrographs show the nanorods-like morphology of V2O5. The AFM micrographs exhibit a well covered granular surface topography. For direct allowed transition, the band gap energy values are found to be decreased from 2.45 eV to 2.42 eV. The nanorods deposited with 30 mM solution concentration shows the maximum response of 24.2% for 100 ppm NO2 gas concentration at an operating temperature of 200 °C with response and recovery times of 13 s and 140 s, respectively. Finally, the chemisorption mechanism of NO2 gas on the V2O5 nanorods is discussed.

Invited Article: High resolution angle resolved photoemission with tabletop 11 eV laser

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

He, Yu; Vishik, Inna M.; Yi, Ming

2016-01-15

We developed a table-top vacuum ultraviolet (VUV) laser with 113.778 nm wavelength (10.897 eV) and demonstrated its viability as a photon source for high resolution angle-resolved photoemission spectroscopy (ARPES). This sub-nanosecond pulsed VUV laser operates at a repetition rate of 10 MHz, provides a flux of 2 × 10{sup 12} photons/s, and enables photoemission with energy and momentum resolutions better than 2 meV and 0.012 Å{sup −1}, respectively. Space-charge induced energy shifts and spectral broadenings can be reduced below 2 meV. The setup reaches electron momenta up to 1.2 Å{sup −1}, granting full access to the first Brillouin zone ofmore » most materials. Control over the linear polarization, repetition rate, and photon flux of the VUV source facilitates ARPES investigations of a broad range of quantum materials, bridging the application gap between contemporary low energy laser-based ARPES and synchrotron-based ARPES. We describe the principles and operational characteristics of this source and showcase its performance for rare earth metal tritellurides, high temperature cuprate superconductors, and iron-based superconductors.« less

Deep-level transient spectroscopy of Pd-H complexes in silicon

NASA Astrophysics Data System (ADS)

Sachse, J.-U.; Weber, J.; Lemke, H.

2000-01-01

The interaction of atomic hydrogen with substitutional palladium impurities is studied in n- and p-type Si by deep-level transient spectroscopy. After wet-chemical etching, we determine seven different electrically active and at least one passive palladium hydrogen complex. The levels belong to Pd complexes with different number of hydrogen atoms. The PdH1 complex exhibits one level E(200) at EC-0.43 eV. PdH2 has two levels E(60) at EC-0.10 eV and H(280) at EV+0.55 eV. Four levels are assigned to the PdH3 complex E(160) at EC-0.29 eV, H(140) at EV+0.23 eV, H(55) at EV+0.08 eV, and H(45) at EV+0.07 eV. An electrically passive complex is associated with a PdH4 complex. There is great similarity with the correspondent complexes in Pt-doped Si. Annealing above 650 K destroys all hydrogen related complexes and restores the original substitutional Pd concentration.

Metabolomic Profiling of Extracellular Vesicles and Alternative Normalization Methods Reveal Enriched Metabolites and Strategies to Study Prostate Cancer-Related Changes

PubMed Central

Puhka, Maija; Takatalo, Maarit; Nordberg, Maria-Elisa; Valkonen, Sami; Nandania, Jatin; Aatonen, Maria; Yliperttula, Marjo; Laitinen, Saara; Velagapudi, Vidya; Mirtti, Tuomas; Kallioniemi, Olli; Rannikko, Antti; Siljander, Pia R-M; af Hällström, Taija Maria

2017-01-01

Body fluids are a rich source of extracellular vesicles (EVs), which carry cargo derived from the secreting cells. So far, biomarkers for pathological conditions have been mainly searched from their protein, (mi)RNA, DNA and lipid cargo. Here, we explored the small molecule metabolites from urinary and platelet EVs relative to their matched source samples. As a proof-of-concept study of intra-EV metabolites, we compared alternative normalization methods to profile urinary EVs from prostate cancer patients before and after prostatectomy and from healthy controls. Methods: We employed targeted ultra-performance liquid chromatography-tandem mass spectrometry to profile over 100 metabolites in the isolated EVs, original urine samples and platelets. We determined the enrichment of the metabolites in the EVs and analyzed their subcellular origin, pathways and relevant enzymes or transporters through data base searches. EV- and urine-derived factors and ratios between metabolites were tested for normalization of the metabolomics data. Results: Approximately 1 x 1010 EVs were sufficient for detection of metabolite profiles from EVs. The profiles of the urinary and platelet EVs overlapped with each other and with those of the source materials, but they also contained unique metabolites. The EVs enriched a selection of cytosolic metabolites including members from the nucleotide and spermidine pathways, which linked to a number of EV-resident enzymes or transporters. Analysis of the urinary EVs from the patients indicated that the levels of glucuronate, D-ribose 5-phosphate and isobutyryl-L-carnitine were 2-26-fold lower in all pre-prostatectomy samples compared to the healthy control and post-prostatectomy samples (p < 0.05). These changes were only detected from EVs by normalization to EV-derived factors or with metabolite ratios, and not from the original urine samples. Conclusions: Our results suggest that metabolite analysis of EVs from different samples is feasible using a high-throughput platform and relatively small amount of sample material. With the knowledge about the specific enrichment of metabolites and normalization methods, EV metabolomics could be used to gain novel biomarker data not revealed by the analysis of the original EV source materials. PMID:29109780

Abundance of enterovirus C in RD-L20B cell culture-negative stool samples from acute flaccid paralysis cases in Nigeria is geographically defined.

PubMed

Donbraye, Emmanuel; Olasunkanmi, Oluwatayo Israel; Opabode, Babatunde Ayoola; Ishola, Temitayo Rachael; Faleye, Temitope Oluwasegun Cephas; Adewumi, Olubusuyi Moses; Adeniji, Johnson Adekunle

2018-06-01

We recently showed that enteroviruses (EVs) andenterovirus species C (EV-C) in particular were abundant in faecal samples from children who had been diagnosed with acute flaccid paralysis (AFP) in Nigeria but declared to be EV-free by the RD-L20B cell culture-based algorithm. In this study, we investigated whether this observed preponderance of EVs (and EV-Cs) in such samples varies by geographical region. One hundred and eight samples (i.e. 54 paired stool suspensions from 54 AFP cases) that had previously been confirmed to be negative for EVs by the WHO-recommended RD-L20B cell culture-based algorithm were analysed. The 108 samples were made into 54 pools (27 each from North-West and South-South Nigeria). All were subjected to RNA extraction, cDNA synthesis and the WHO-recommended semi-nested PCR assay and its modifications. All of the amplicons were sequenced, and the enteroviruses identified, using the enterovirus genotyping tool and phylogenetic analysis. EVs were detected in 16 (29.63 %) of the 54 samples that were screened and successfully identified in 14 (25.93 %). Of these, 10 were from North-West and 4 were from South-South Nigeria. One (7.14 %), 2 (14.29 %) and 11 (78.57 %) of the strains detected were EV-A, EV-B and EV-C, respectively. The 10 strains from North-West Nigeria included 7 EV types, namely CV-A10, E29, CV-A13, CV-A17, CV-A19, CV-A24 and EV-C99. The four EV types recovered from South-South Nigeria were E31, CV-A1, EV-C99 and EV-C116. The results of this study showed that the presence of EVs and consequently EV-Cs in AFP samples declared to be EV-free by the RD-L20B cell culture-based algorithm varies by geographical region in Nigeria.

Yersinia pestis biovar Microtus strain 201, an avirulent strain to humans, provides protection against bubonic plague in rhesus macaques.

PubMed

Zhang, Qingwen; Wang, Qiong; Tian, Guang; Qi, Zhizhen; Zhang, Xuecan; Wu, Xiaohong; Qiu, Yefeng; Bi, Yujing; Yang, Xiaoyan; Xin, Youquan; He, Jian; Zhou, Jiyuan; Zeng, Lin; Yang, Ruifu; Wang, Xiaoyi

2014-01-01

Yersinia pestis biovar Microtus is considered to be a virulent to larger mammals, including guinea pigs, rabbits and humans. It may be used as live attenuated plague vaccine candidates in terms of its low virulence. However, the Microtus strain's protection against plague has yet to be demonstrated in larger mammals. In this study, we evaluated the protective efficacy of the Microtus strain 201 as a live attenuated plague vaccine candidate. Our results show that this strain is highly attenuated by subcutaneous route, elicits an F1-specific antibody titer similar to the EV and provides a protective efficacy similar to the EV against bubonic plague in Chinese-origin rhesus macaques. The Microtus strain 201 could induce elevated secretion of both Th1-associated cytokines (IFN-γ, IL-2 and TNF-α) and Th2-associated cytokines (IL-4, IL-5, and IL-6), as well as chemokines MCP-1 and IL-8. However, the protected animals developed skin ulcer at challenge site with different severity in most of the immunized and some of the EV-immunized monkeys. Generally, the Microtus strain 201 represented a good plague vaccine candidate based on its ability to generate strong humoral and cell-mediated immune responses as well as its good protection against high dose of subcutaneous virulent Y. pestis challenge.

Yersinia pestis biovar Microtus strain 201, an avirulent strain to humans, provides protection against bubonic plague in rhesus macaques

PubMed Central

Zhang, Qingwen; Wang, Qiong; Tian, Guang; Qi, Zhizhen; Zhang, Xuecan; Wu, Xiaohong; Qiu, Yefeng; Bi, Yujing; Yang, Xiaoyan; Xin, Youquan; He, Jian; Zhou, Jiyuan; Zeng, Lin; Yang, Ruifu; Wang, Xiaoyi

2014-01-01

Yersinia pestis biovar Microtus is considered to be a virulent to larger mammals, including guinea pigs, rabbits and humans. It may be used as live attenuated plague vaccine candidates in terms of its low virulence. However, the Microtus strain’s protection against plague has yet to be demonstrated in larger mammals. In this study, we evaluated the protective efficacy of the Microtus strain 201 as a live attenuated plague vaccine candidate. Our results show that this strain is highly attenuated by subcutaneous route, elicits an F1-specific antibody titer similar to the EV and provides a protective efficacy similar to the EV against bubonic plague in Chinese-origin rhesus macaques. The Microtus strain 201 could induce elevated secretion of both Th1-associated cytokines (IFN-γ, IL-2 and TNF-α) and Th2-associated cytokines (IL-4, IL-5, and IL-6), as well as chemokines MCP-1 and IL-8. However, the protected animals developed skin ulcer at challenge site with different severity in most of the immunized and some of the EV-immunized monkeys. Generally, the Microtus strain 201 represented a good plague vaccine candidate based on its ability to generate strong humoral and cell-mediated immune responses as well as its good protection against high dose of subcutaneous virulent Y. pestis challenge. PMID:24225642

Complementary roles of benzylpiperazine and iodine 'vapor' in the strong enhancement of orange photoluminescence from CuI(1 1 1) thin film.

PubMed

Rawal, Takat B; Turkowski, Volodymyr; Rahman, Talat S

2014-05-07

We have employed density functional theory, corrected by the on-site electron-electron repulsion energy U, to clarify the mechanism behind the enhanced orange photoluminescence (PL) of a CuI(1 1 1) thin film conjugated with a benzylpiperazine (BZP) molecule in the presence of an iodine 'vapor' atom. Our results demonstrated that the adsorbed molecule and the 'vapor' atom play complementary roles in producing the PL. The latter, in attaching to the film surface, creates a hole-trapping surface state located ~0.25 eV above the valence band-edge of the film, in good agreement with ~0.2 eV reported in experiments. Upon photo-excitation of the BZP/CuI(1 1 1) system in the presence of surface iodine 'vapor' atoms, excited electrons are transferred into the conduction band of CuI, and holes are trapped by the 'vapor' atoms. These holes, in turn, quickly relax into the HOMO state of the BZP molecule, owing to the fact that the molecule adsorbs on the film surface in the immediate vicinity of a 'vapor' atom. Relaxed holes subsequently recombine with excited electrons in the conduction band of the CuI film, thereby producing a luminescence peak at ~2.1 eV, in qualitative agreement with experimental findings.

MnNiO3 revisited with modern theoretical and experimental methods

NASA Astrophysics Data System (ADS)

Dzubak, Allison L.; Mitra, Chandrima; Chance, Michael; Kuhn, Stephen; Jellison, Gerald E.; Sefat, Athena S.; Krogel, Jaron T.; Reboredo, Fernando A.

2017-11-01

MnNiO3 is a strongly correlated transition metal oxide that has recently been investigated theoretically for its potential application as an oxygen-evolution photocatalyst. However, there is no experimental report on critical quantities such as the band gap or bulk modulus. Recent theoretical predictions with standard functionals such as LDA+U and HSE show large discrepancies in the band gaps (about 1.23 eV), depending on the nature of the functional used. Hence there is clearly a need for an accurate quantitative prediction of the band gap to gauge its utility as a photocatalyst. In this work, we present a diffusion quantum Monte Carlo study of the bulk properties of MnNiO3 and revisit the synthesis and experimental properties of the compound. We predict quasiparticle band gaps of 2.0(5) eV and 3.8(6) eV for the majority and minority spin channels, respectively, and an equilibrium volume of 92.8 Å3, which compares well to the experimental value of 94.4 Å3. A bulk modulus of 217 GPa is predicted for MnNiO3. We rationalize the difficulty for the formation of ordered ilmenite-type structure with specific sites for Ni and Mn to be potentially due to the formation of antisite defects that form during synthesis, which ultimately affects the physical properties of MnNiO3.

Extracellular Vesicle Heterogeneity: Subpopulations, Isolation Techniques, and Diverse Functions in Cancer Progression.

PubMed

Willms, Eduard; Cabañas, Carlos; Mäger, Imre; Wood, Matthew J A; Vader, Pieter

2018-01-01

Cells release membrane enclosed nano-sized vesicles termed extracellular vesicles (EVs) that function as mediators of intercellular communication by transferring biological information between cells. Tumor-derived EVs have emerged as important mediators in cancer development and progression, mainly through transfer of their bioactive content which can include oncoproteins, oncogenes, chemokine receptors, as well as soluble factors, transcripts of proteins and miRNAs involved in angiogenesis or inflammation. This transfer has been shown to influence the metastatic behavior of primary tumors. Moreover, tumor-derived EVs have been shown to influence distant cellular niches, establishing favorable microenvironments that support growth of disseminated cancer cells upon their arrival at these pre-metastatic niches. It is generally accepted that cells release a number of major EV populations with distinct biophysical properties and biological functions. Exosomes, microvesicles, and apoptotic bodies are EV populations most widely studied and characterized. They are discriminated based primarily on their intracellular origin. However, increasing evidence suggests that even within these EV populations various subpopulations may exist. This heterogeneity introduces an extra level of complexity in the study of EV biology and function. For example, EV subpopulations could have unique roles in the intricate biological processes underlying cancer biology. Here, we discuss current knowledge regarding the role of subpopulations of EVs in cancer development and progression and highlight the relevance of EV heterogeneity. The position of tetraspanins and integrins therein will be highlighted. Since addressing EV heterogeneity has become essential for the EV field, current and novel techniques for isolating EV subpopulations will also be discussed. Further dissection of EV heterogeneity will advance our understanding of the critical roles of EVs in health and disease.

Increased Risk of Tics in Children Infected with Enterovirus: A Nationwide Population-Based Study.

PubMed

Lin, Jiun-Nong; Lin, Cheng-Li; Yen, Hung-Rong; Yang, Chi-Hui; Lai, Chung-Hsu; Lin, Hsi-Hsun; Kao, Chia-Hung

2017-05-01

Both tics and enterovirus (EV) infections are common in children. The association between EV infections and tics has been seldom evaluated. The aim of this study was to evaluate the risk of diagnosed tics after EV infections in children. A nationwide retrospective cohort study was conducted to determine the risk of tics after EV infections by analyzing data from the National Health Insurance Research Database in Taiwan. Children aged < 18 years with EV infection during 2000 to 2007 were enrolled. For comparison, non-EV-infected children were randomly selected and matched with EV-infected children at a 1:1 ratio according to sex, age, urbanization level, parental occupation, and the year of EV infection. All patients were followed up until the diagnosis of tics, death, loss to follow-up, withdrawal from the insurance system, or December 31, 2008. A total of 282,321 EV-infected and 282,317 non-EV-infected children were included in this study. The mean age was 2.39 years in both cohorts. The overall incidences of tics were 9.12 and 6.21 per 10,000 person-years in the EV-infected and non-EV-infected cohorts, respectively. Children with EV infection were significantly associated with an increased risk of tics compared with those without EV infection (adjusted hazard ratio, 1.38; 95% confidence interval, 1.27-1.5). Multivariable analyses showed that boys, children living in urbanized areas, children whose parents had white-collar jobs, and children with allergic rhinitis or bronchial asthma exhibited a significantly increased risk of tics. This study revealed an increased risk of tics after EV infection in children.