A preliminary report on stem cell therapy for neuropathic pain in humans

Directory of Open Access Journals (Sweden)

Vickers ER

2014-05-01

Full Text Available E Russell Vickers,1 Elisabeth Karsten,2 John Flood,3 Richard Lilischkis21Sydney Oral and Maxillofacial Surgery, NSW, Australia; 2Regeneus Ltd, Gordon, NSW, Australia; 3St Vincents Hospital, Sydney, NSW, AustraliaObjective: Mesenchymal stem cells (MSCs have been shown in animal models to attenuate chronic neuropathic pain. This preliminary study investigated if: i injections of autologous MSCs can reduce human neuropathic pain and ii evaluate the safety of the procedure.Methods: Ten subjects with symptoms of neuropathic trigeminal pain underwent liposuction. The lipoaspirate was digested with collagenase and washed with saline three times. Following centrifugation, the stromal vascular fraction was resuspended in saline, and then transferred to syringes for local injections into the pain fields. Outcome measures at 6 months assessed reduction in: i pain intensity measured by standard numerical rating scale from 0–10 and ii daily dosage requirements of antineuropathic pain medication.Results: Subjects were all female (mean age 55.3 years ± standard deviation [SD] 14.67; range 27–80 years with pain symptoms lasting from 4 months to 6 years and 5 months. Lipoaspirate collection ranged from 102–214 g with total cell numbers injected from 33 million to 162 million cells. Cell viability was 62%–91%. There were no systemic or local tissue side effects from the stem cell therapy (n=41 oral and facial injection sites. Clinical pain outcomes showed that at 6 months, 5/9 subjects had reduced both pain intensity scores and use of antineuropathic medication. The mean pain score pre-treatment was 7.5 (SD 1.58 and at 6 months had decreased to 4.3 (SD 3.28, P=0.018, Wilcoxon signed-rank test. Antineuropathic pain medication use showed 5/9 subjects reduced their need for medication (gabapentin, P=0.053, Student's t-test.Conclusion: This preliminary open-labeled study showed autologous administration of stem cells for neuropathic trigeminal pain

Preliminary performance test of control rod position indicator for ballscrew type CEDM

International Nuclear Information System (INIS)

Yoo, J. Y.; Kim, J. H.; Hu, H.; Lee, J. S.; Kim, J. I.

2003-01-01

The reliability and accuracy of the information on control rod position are very important to the reactor safety and the design of the core protection system. A survey on the RSPT(Reed Switch Position Transmitter) type control rod position indication system and its actual implementation in the exiting nuclear power plants in Korea was performed first. The prototype of control rod position indicator having the high performance for the ballscrew type CEDM was developed on the basis of RSPT technology identified through the survey. The characteristics of control rod position indicator was defined and documented through design procedure and preliminary performance test

Behavior of HepG2 liver cancer cells using microfluidic-microscopy: a preliminary study

Science.gov (United States)

Karamahmutoglu, Hande; ćetin, Metin; Yaǧcı, Tamer; Elitaş, Meltem

2018-02-01

Hepatocellular carcinoma is one of the most common types of liver cancer causing death all over the world. Although early-stage liver cancer can sometimes be treated with partial hepatectomy, liver transplantation, ablation, and embolization, sorafenib treatment is the only approved systemic therapy for advanced HCC. The aim of this research is to develop tools and methods to understand the individuality of hepatocellular carcinoma. Microfluidic cell-culture platform has been developed to observe behavior of single-cells; fluorescence microscopy has been implemented to investigate phenotypic changes of cells. Our preliminary data proved high-level heterogeneity of hepatocellular carcinoma while verifying limited growth of liver cancer cell lines on the silicon wafer.

A Preliminary Analysis of Reactor Performance Test (LOEP) for a Research Reactor

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyeonil; Park, Su-Ki [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

The final phase of commissioning is reactor performance test, which is to prove the integrated performance and safety of the research reactor at full power with fuel loaded such as neutron power calibration, Control Absorber Rod/Second Shutdown Rod drop time, InC function test, Criticality, Rod worth, Core heat removal with natural mechanism, and so forth. The last test will be safety-related one to assure the result of the safety analysis of the research reactor is marginal enough to be sure about the nuclear safety by showing the reactor satisfies the acceptance criteria of the safety functions such as for reactivity control, maintenance of auxiliaries, reactor pool water inventory control, core heat removal, and confinement isolation. After all, the fuel integrity will be ensured by verifying there is no meaningful change in the radiation levels. To confirm the performance of safety equipment, loss of normal electric power (LOEP), possibly categorized as Anticipated Operational Occurrence (AOO), is selected as a key experiment to figure out how safe the research reactor is before turning over the research reactor to the owner. This paper presents a preliminary analysis of the reactor performance test (LOEP) for a research reactor. The results showed how different the transient between conservative estimate and best estimate will look. Preliminary analyses have shown all probable thermal-hydraulic transient behavior of importance as to opening of flap valve, minimum critical heat flux ratio, the change of flow direction, and important values of thermal-hydraulic parameters.

Cell kinetics of gastrointestinal tumors after different nutritional regimens. A preliminary report

International Nuclear Information System (INIS)

Franchi, F.; Rossi-Fanelli, F.; Seminara, P.; Cascino, A.; Barone, C.; Scucchi, L.

1991-01-01

Forty-four cases of different untreated gastrointestinal tumors were studied with regard to cell kinetic activity. As a pilot experiment, the authors also determined the 3H-TdR Labeling Index (LI) in 28 patients in basal conditions and after 15 days of nutritional manipulation with prevalently lipid-based or glucose-based feeding to ascertain whether selective nutritional regimens could affect tumor proliferation. Preliminary results from this study indicate that a kinetic perturbation is induced in tumor cells by nutritional manipulation. Lipid-based feeding seems to produce effects similar to those of chemical or physical anticancer agents, thus suggesting a possible supporting role of nutritional manipulation in cancer treatment strategy

Preliminary performance assessment for the Waste Isolation Pilot Plant, December 1992. Volume 3, Model parameters: Sandia WIPP Project

Energy Technology Data Exchange (ETDEWEB)

1992-12-29

This volume documents model parameters chosen as of July 1992 that were used by the Performance Assessment Department of Sandia National Laboratories in its 1992 preliminary performance assessment of the Waste Isolation Pilot Plant (WIPP). Ranges and distributions for about 300 modeling parameters in the current secondary data base are presented in tables for the geologic and engineered barriers, global materials (e.g., fluid properties), and agents that act upon the WIPP disposal system such as climate variability and human-intrusion boreholes. The 49 parameters sampled in the 1992 Preliminary Performance Assessment are given special emphasis with tables and graphics that provide insight and sources of data for each parameter.

Preliminary evaluation of rotational Vol-oxidizer for hot cell operation - 5320

International Nuclear Information System (INIS)

Kim, Y.H.; Lee, J.W.; Cho, Y.Z.; Ahn, D.H.; Song, K.C.

2015-01-01

KAERI is developing a mechanical head-end process for pyro-processing. As a piece of the processing equipment, a vol-oxidizer that can handle several tens of kg of HM/batch is under development to supply U 3 O 8 powders to an electrolytic reduction (ER) reactor. To operate a vol-oxidizer in a hot cell, the reactor should be optimized by the mechanical design, and the vol-oxidizer should have a high hull recovery rate. In addition, a vol-oxidizer for hot cell demonstrations that handles the spent fuel of high radiation virulence in a limited space should have a small size and not scatter in its outlet. In this paper, we aim at a preliminary evaluation of a rotational vol-oxidizer for hot cell operation. To evaluate the preliminary situation, we produced a theoretical equation of an optimum reactor size, and verification tests were conducted using an acryl vessel and zircaloy-4 tube according to various weights and lengths. In addition, we predicted the terminal velocity of U 3 O 8 using the terminal velocity of SiO 2 , which will determine the optimum air flux, and through an oxidation experiment, we verified the theory form to detect the existence of U 3 O 8 powder in a discharge filter. In addition, hull separation tests were conducted using a reactor and hulls with a 50 kg HM/batch for the recovery rate of the hulls. The results indicate that we obtained an appropriate air flux so as to not cause U 3 O 8 powder dispersion from using a Stokes equation and density ratio equation prior to the demonstration. The optimum flow and experimental results of the hull separation test have been applied for the design of the demonstration oxidizer, and the operation conditions of the oxidizer were produced. (authors)

Guidance for performing preliminary assessments under CERCLA

Energy Technology Data Exchange (ETDEWEB)

NONE

1991-09-01

EPA headquarters and a national site assessment workgroup produced this guidance for Regional, State, and contractor staff who manage or perform preliminary assessments (PAs). EPA has focused this guidance on the types of sites and site conditions most commonly encountered. The PA approach described in this guidance is generally applicable to a wide variety of sites. However, because of the variability among sites, the amount of information available, and the level of investigative effort required, it is not possible to provide guidance that is equally applicable to all sites. PA investigators should recognize this and be aware that variation from this guidance may be necessary for some sites, particularly for PAs performed at Federal facilities, PAs conducted under EPA`s Environmental Priorities Initiative (EPI), and PAs at sites that have previously been extensively investigated by EPA or others. The purpose of this guidance is to provide instructions for conducting a PA and reporting results. This guidance discusses the information required to evaluate a site and how to obtain it, how to score a site, and reporting requirements. This document also provides guidelines and instruction on PA evaluation, scoring, and the use of standard PA scoresheets. The overall goal of this guidance is to assist PA investigators in conducting high-quality assessments that result in correct site screening or further action recommendations on a nationally consistent basis.

The Performance of a Direct Borohydride/Peroxide Fuel Cell Using Graphite Felts as Electrodes

Directory of Open Access Journals (Sweden)

Heng-Yi Lee

2017-08-01

Full Text Available A direct borohydride/peroxide fuel cell (DBPFC generates electrical power by recirculating liquid anolyte and catholyte between the stack and reservoirs, which is similar to the operation of flow batteries. To enhance the accessibility of the catalyst layer to the liquid anolyte/catholyte, graphite felts are employed as the porous diffusion layer of a single-cell DBPFC instead of carbon paper/cloth. The effects of the type of anode alkaline solution and operating conditions, including flow rate and temperature of the anolyte/catholyte, on DBPFC performance are investigated and discussed. The durability of the DBPFC is also evaluated by galvanostatic discharge at 0.1 A∙cm−2 for over 50 h. The results of this preliminary study show that a DBPFC with porous graphite electrodes can provide a maximum power density of 0.24 W∙cm−2 at 0.8 V. The performance of the DBPFC drops slightly after 50 h of operation; however, the discharge capacity shows no significant decrease.

Preliminary evaluation of optical glucose sensing in red cell concentrations using near-infrared diffuse-reflectance spectroscopy

Science.gov (United States)

Suzuki, Yusuke; Maruo, Katsuhiko; Zhang, Alice W.; Shimogaki, Kazushige; Ogawa, Hideto; Hirayama, Fumiya

2012-01-01

Bacterial contamination of blood products is one of the most frequent infectious complications of transfusion. Since glucose levels in blood supplies decrease as bacteria proliferate, it should be possible to detect the presence of bacterial contamination by measuring the glucose concentrations in the blood components. Hence this study is aimed to serve as a preliminary study for the nondestructive measurement of glucose level in transfusion blood. The glucose concentrations in red blood cell (RBC) samples were predicted using near-infrared diffuse-reflectance spectroscopy in the 1350 to 1850 nm wavelength region. Furthermore, the effects of donor, hematocrit level, and temperature variations among the RBC samples were observed. Results showed that the prediction performance of a dataset which contained samples that differed in all three parameters had a standard error of 29.3 mg/dL. Multiplicative scatter correction (MSC) preprocessing method was also found to be effective in minimizing the variations in scattering patterns created by various sample properties. The results suggest that the diffuse-reflectance spectroscopy may provide another avenue for the detection of bacterial contamination in red cell concentrations (RCC) products.

Immunohistochemical characterisation of the hepatic stem cell niche in feline hepatic lipidosis: a preliminary morphological study.

Science.gov (United States)

Valtolina, Chiara; Robben, Joris H; Favier, Robert P; Rothuizen, Jan; Grinwis, Guy Cm; Schotanus, Baukje A; Penning, Louis C

2018-05-01

Objectives The aim of this study was to describe the cellular and stromal components of the hepatic progenitor cell niche in feline hepatic lipidosis (FHL). Methods Immunohistochemical staining for the progenitor/bile duct marker (K19), activated Kupffer cells (MAC387), myofibroblasts (alpha-smooth muscle actin [α-SMA]) and the extracellular matrix component laminin were used on seven liver biopsies of cats with FHL and three healthy cats. Double immunofluorescence stainings were performed to investigate co-localisation of different cell types in the hepatic progenitor cell (HPC) niche. Results HPCs, Kupffer cells, myofibroblasts and laminin deposition were observed in the liver samples of FHL, although with variability in the expression and positivity of the different immunostainings between different samples. When compared with the unaffected cats where K19 positivity and minimal α-SMA and laminin positivity were seen mainly in the portal area, in the majority of FHL samples K19 and α-SMA-positive cells and laminin positivity were seen also in the periportal and parenchymatous area. MAC387-positive cells were present throughout the parenchyma. Conclusions and relevance This is a preliminary morphological study to describe the activation and co-localisation of components of the HPC niche in FHL. Although the HPC niche in FHL resembles that described in hepatopathies in dogs and in feline lymphocytic cholangitis, the expression of K19, α-SMA, MAC387 and lamin is more variable in FHL, and a common pattern of activation could not be established. Nevertheless, when HPCs were activated, a spatial association between HPCs and their niche could be demonstrated.

Preliminary performance assessment for the Waste Isolation Pilot Plant, December 1992

International Nuclear Information System (INIS)

1992-12-01

Before disposing of transuranic radioactive waste in the Waste Isolation Pilot Plant (WIPP), the United States Department of Energy (DOE) must evaluate compliance with applicable long-term regulations of the United States Environmental Protection Agency (EPA). Sandia National Laboratories is conducting iterative performance assessments (PAs) of the WIPP for the DOE to provide interim guidance while preparing for a final compliance evaluation. This volume, Volume 2, contains the technical basis for the 1992 PA. Specifically, it describes the conceptual basis for consequence modeling and the PA methodology, including the selection of scenarios for analysis, the determination of scenario probabilities, and the estimation of scenario consequences using a Monte Carlo technique and a linked system of computational models. Additional information about the 1992 PA is provided in other volumes. Volume I contains an overview of WIPP PA and results of a preliminary comparison with the long-term requirements of the EPA's Environmental Protection Standards for Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes (40 CFR 191, Subpart B). Volume 3 contains the reference data base and values for input parameters used in consequence and probability modeling. Volume 4 contains uncertainty and sensitivity analyses related to the preliminary comparison with 40 CFR 191B. Volume 5 contains uncertainty and sensitivity analyses of gas and brine migration for undisturbed performance. Finally, guidance derived from the entire 1992 PA is presented in Volume 6

Expression, purification, crystallization and preliminary X-ray analysis of the olfactomedin domain from the sea urchin cell-adhesion protein amassin

International Nuclear Information System (INIS)

Hillier, Brian J.; Sundaresan, Vidyasankar; Stout, C. David; Vacquier, Victor D.

2005-01-01

The olfactomedin (OLF) domain from the sea urchin cell-adhesion protein amassin has been crystallized. A native data set extending to 2.7 Å has been collected using an in-house X-ray source. A family of animal proteins is emerging which contain a conserved protein motif known as an olfactomedin (OLF) domain. Novel extracellular protein–protein interactions occur through this domain. The OLF-family member amassin, from the sea urchin Strongylocentrotus purpuratus, has previously been identified to mediate a rapid cell-adhesion event resulting in a large aggregation of coelomocytes, the circulating immune cells. In this work, heterologous expression and purification of the OLF domain from amassin was carried out and initial crystallization trials were performed. A native data set has been collected, extending to 2.7 Å under preliminary cryoconditions, using an in-house generator. This work leads the way to the determination of the first structure of an OLF domain

Barrier analogs: Long-term performance issues, preliminary studies, and recommendations

Energy Technology Data Exchange (ETDEWEB)

Waugh, W.J. [Rust Geotech, Inc., Grand Junction, CO (United States). Environmental Sciences Lab.; Chatters, J.C.; Last, G.V.; Bjornstad, B.N.; Link, S.O. [Pacific Northwest Lab., Richland, WA (United States); Hunter, C.R. [Cascade Earth Sciences, La Grande, OR (United States)

1994-02-01

The US Department of Energy`s Hanford Protective Barrier Development Program is funding studies of natural analogs of the long-term performance of waste site covers. Natural-analog studies examine past environments as evidence for projecting the future performance of engineered structures. The information generated by analog studies is needed to (1) evaluate the designs and results of short term experiments and demonstrations, (2) formulate performance-modeling problems that bound expected changes in waste site environments, and (3) understand emergent system attributes that cannot be evaluated with short-term experiments or computer models. Waste site covers will be part of dynamic environmental systems with attributes that transcend the traits of engineered components. This report discusses results of the previously unreported preliminary studies conducted in 1983 and 1984. These results indicate that analogs could play an important role in predicting the long-term behavior of engineered waste covers. Layered exposures of glacial-flood-deposited gravels mantled with silt or sand that resemble contemporary barrier designs were examined. Bergmounds, another anomaly left by cataclysmic glacial floods, were also examined as analogs of surface gravel.

Preliminary assessment of adjuster system performance in CANDU-6 RUFIC core

International Nuclear Information System (INIS)

Kim, Soon Young; Suk, Ho Chun

2002-07-01

Four operational transients in CANDU-6 RUFIC core have been simulated to assess the adjuster system performance. These transients included startup after a short shutdown, startup after a poison-out shutdown, shim mode operation, and a stepback to 60% full power. Also, an alternative adjuster-banking scheme has been assessed in this report. The alternative adjuster-banking scheme involves rods in Bank 1 and Bank 7 being re-distributed within the two banks. In the alternative adjuster-banking scheme, Bank 1 becomes the heaviest one. The results of the preliminary assessment indicated that the adjuster system as currently designed and installed in the NU core will adequately meet the functional requirements in the RUFIC core. Comparing to the adjuster system performance in the NU core, the total worth of the adjuster in the RUFIC core is reduced, leading to less xenon override capability and shimming capability. However, the overall performance is expected to still be satisfactory. The overall results from the transient studied indicated that the alternative banking scheme does show some better performance characteristics and merits further detailed studies

Preliminary estimation of the dose rates of the operation room of the RPR radioisotope cell

International Nuclear Information System (INIS)

Rocha, A.C.S.; Silva, J.J.G.; Pina, J.L.S. de; Fajardo, P.W.

1986-07-01

During the preliminary studies, about the installations layout of a radioisotope production reactor, the possibility of construction of a radioisotope cell at the reactor building has been investigated. The decisions about that construction has considered mainly the level of the radiation dose over the cell operator. The dose rate has been calculated based on: neutron flux and gamma radiation from fission products and activation materials inside the reactor; volatile fission products such as noble gases and iodides; tritium form ternary fission. The objective was calculate the radiation dose over the cell operator during a journey of 8 hours of work per day. For those calculations some data have been obtained from the Angra-3 reactor. (author)

Preliminary results of Digital Pulse Shape Acquisition from Chimera

International Nuclear Information System (INIS)

Alderighi, D.M.; Sechi, G.; Anzalone, A.; Cavallaro, S.; Giustolisi, F.; Laguidara, E.; Lanzalone, G.; Porto, F.; Bassini, R.; Boiano, C.; Guazzoni, P.; Russo, S.; Sassi, M.; Zetta, L.; Cardella, G.; Defilippo, S.E.; Lanzano, G.; Paganod, A.; Papa, M.; Pirrone, S.; Politi, G.; Geraci, E.

2003-01-01

A 100 MS/s 14-bit Sampling Analog-to-Digital converter has been used to perform digital pulse-shape acquisition of signals collected from CHIMERA telescopes. The signals from a typical CHIMERA detection cell have been collected using both a standard CHIMERA electronic chain up to the amplifier, and a very simple analog front end, basically reduced to the preamplifier. The preliminary on-beam results are presented. (authors)

Preliminary results of Digital Pulse Shape Acquisition from Chimera

Energy Technology Data Exchange (ETDEWEB)

Alderighi, D.M.; Sechi, G. [INFN Milano and IASF, CNR, Milano (France); Anzalone, A.; Cavallaro, S.; Giustolisi, F.; Laguidara, E.; Lanzalone, G.; Porto, F. [Catania Univ., LNS and Dipartimento di Fisica (France); Bassini, R.; Boiano, C.; Guazzoni, P.; Russo, S.; Sassi, M.; Zetta, L. [Milano Univ., INFN and Dipartimento di Fisica (Italy); Cardella, G.; Defilippo, S.E.; Lanzano, G.; Paganod, A.; Papa, M.; Pirrone, S.; Politi, G. [Catania Univ., INFN and Dipartimento di Fisica (Italy); Geraci, E. [Bologna Univ., INFN and Dipartimento di Fisica (Italy)

2003-07-01

A 100 MS/s 14-bit Sampling Analog-to-Digital converter has been used to perform digital pulse-shape acquisition of signals collected from CHIMERA telescopes. The signals from a typical CHIMERA detection cell have been collected using both a standard CHIMERA electronic chain up to the amplifier, and a very simple analog front end, basically reduced to the preamplifier. The preliminary on-beam results are presented. (authors)

Handbook of fuel cell performance

Energy Technology Data Exchange (ETDEWEB)

Benjamin, T.G.; Camara, E.H.; Marianowski, L.G.

1980-05-01

The intent of this document is to provide a description of fuel cells, their performances and operating conditions, and the relationship between fuel processors and fuel cells. This information will enable fuel cell engineers to know which fuel processing schemes are most compatible with which fuel cells and to predict the performance of a fuel cell integrated with any fuel processor. The data and estimates presented are for the phosphoric acid and molten carbonate fuel cells because they are closer to commercialization than other types of fuel cells. Performance of the cells is shown as a function of operating temperature, pressure, fuel conversion (utilization), and oxidant utilization. The effect of oxidant composition (for example, air versus O/sub 2/) as well as fuel composition is examined because fuels provided by some of the more advanced fuel processing schemes such as coal conversion will contain varying amounts of H/sub 2/, CO, CO/sub 2/, CH/sub 4/, H/sub 2/O, and sulfur and nitrogen compounds. A brief description of fuel cells and their application to industrial, commercial, and residential power generation is given. The electrochemical aspects of fuel cells are reviewed. The phosphoric acid fuel cell is discussed, including how it is affected by operating conditions; and the molten carbonate fuel cell is discussed. The equations developed will help systems engineers to evaluate the application of the phosphoric acid and molten carbonate fuel cells to commercial, utility, and industrial power generation and waste heat utilization. A detailed discussion of fuel cell efficiency, and examples of fuel cell systems are given.

A preliminary report on the SRP [Savannah River Plant] source term study

International Nuclear Information System (INIS)

Woodley, R.E.; Baldwin, D.L.

1984-09-01

The present report describes the experimental system developed for the measurement of fission product release from Savannah River Plant (SRP) fuels and the preliminary measurements performed on unirradiated SRP fuel specimens and simulated irradiated fuel to check out the system prior to its installation in a hot cell for measurements on irradiated SRP fuel

Preliminary Feasibility Study on the Construction of Steel Hot Cell Facility for Precise Manipulated Examinations

International Nuclear Information System (INIS)

Ahn, Sangbok; Kwon, Hyungmun; Kim, Heemoon; Kim, Dosik; Min, Duckkee; Hong, Kwonpyo

2006-01-01

Hot laboratory is essential facility to research and develop in the nuclear industries to examine radioactive materials. The post irradiation examinations for irradiated fuels and materials should be mainly conducted in the hot cell facility to protect radiations to operators. Hot cells are divided into a concrete hot cell and a steel hot cell according to the wall materials. Usually a concrete hot cell is applied to test for high level radioactive materials like as a fuel assembly, rods, and large structure specimens, and a steel hot cell for comparatively lower level activity materials in fuel fragments, and small structural materials. A steel hot cell has many benefits in a specimen manipulation, construction and maintenance costs. In recent the test for the irradiated materials is more frequently required a small and precise manipulating examination for higher degree tests of research and developments. Unfortunately hot laboratory facilities in domestics have mainly constituted of concrete hot cells, and not ready for techniques in steel hot cells. In this paper the construction feasibility of steel hot cell facility is preliminary reviewed in the points of the status of domestic facilities, the test demand prospect and detailed plans

Transoral robotic surgery for the base of tongue squamous cell carcinoma: a preliminary comparison between da Vinci Xi and Si.

Science.gov (United States)

Alessandrini, Marco; Pavone, Isabella; Micarelli, Alessandro; Caporale, Claudio

2017-09-13

Considering the emerging advantages related to da Vinci Xi robotic platform, the aim of this study is to compare for the first time the operative outcomes of this tool to the previous da Vinci Si during transoral robotic surgery (TORS), both performed for squamous cell carcinomas (SCC) of the base of tongue (BOT). Intra- and peri-operative outcomes of eight patients with early stage (T1-T2) of the BOT carcinoma and undergoing TORS by means of the da Vinci Xi robotic platform (Xi-TORS) are compared with the da Vinci Si group ones (Si-TORS). With respect to Si-TORS group, Xi-TORS group demonstrated a significantly shorter overall operative time, console time, and intraoperative blood loss, as well as peri-operative pain intensity and length of mean hospital stays and nasogastric tube positioning. Considering recent advantages offered by surgical robotic techniques, the da Vinci Xi Surgical System preliminary outcomes could suggest its possible future routine implementation in BOT squamous cell carcinoma procedures.

Review of cell performance in anion exchange membrane fuel cells

Science.gov (United States)

Dekel, Dario R.

2018-01-01

Anion exchange membrane fuel cells (AEMFCs) have recently received increasing attention since in principle they allow for the use of non-precious metal catalysts, which dramatically reduces the cost per kilowatt of power in fuel cell devices. Until not long ago, the main barrier in the development of AEMFCs was the availability of highly conductive anion exchange membranes (AEMs); however, improvements on this front in the past decade show that newly developed AEMs have already reached high levels of conductivity, leading to satisfactory cell performance. In recent years, a growing number of research studies have reported AEMFC performance results. In the last three years, new records in performance were achieved. Most of the literature reporting cell performance is based on hydrogen-AEMFCs, although an increasing number of studies have also reported the use of fuels others than hydrogen - such as alcohols, non-alcohol C-based fuels, as well as N-based fuels. This article reviews the cell performance and performance stability achieved in AEMFCs through the years since the first reports in the early 2000s.

Synthesis, Spectral Analysis and Preliminary in Vitro Evaluation of Some Tetrapyrrolic Complexes with 3d Metal Ions

Directory of Open Access Journals (Sweden)

Radu Socoteanu

2015-08-01

Full Text Available In this paper, two tetrapyrrolic complexes, Zn(II-5-(3-hydroxyphenyl-10,15,20-tris-(4-acetoxy-3-methoxyphenylporphyrin and Cu(II-5-(3-hydroxyphenyl-10,15,20-tris-(4-acetoxy-3-methoxyphenylporphyrin were synthesized, and characterized from a spectral and biological point of view. The study provided data concerning the behavior of identical external substituents vs. two different core insertions. Some of the properties of the proposed tetrapyrrolic structures were highlighted, having photodynamic therapy of cancer as a targeted biomedical application. Elemental analysis, NMR, FTIR and UV-Vis data in various solvents were provided. A preliminary in vitro study on normal and cancer cultured cells was carried out for biocompatibility assessment in dark conditions. The preliminary in vitro study performed on human peripheral mononuclear cells exposed to tetrapyrrolic compounds (2 µM showed that the proposed compounds had a convenient cytotoxic profile on human normal peripheral blood mononuclear cells under dark conditions. Meanwhile, the investigated compounds reduced the number of metabolically active breast tumor MCF-7 cells, with the exception of Zn(II complex-containing a symmetrical ligand. Accordingly, preliminary in vitro data suggest that the proposed tetrapyrrolic compounds are good candidates for PDT, as they limit tumor expansion even under dark conditions, whilst sparing normal cells.

Preliminary Evaluation of MapReduce for High-Performance Climate Data Analysis

Science.gov (United States)

Duffy, Daniel Q.; Schnase, John L.; Thompson, John H.; Freeman, Shawn M.; Clune, Thomas L.

2012-01-01

MapReduce is an approach to high-performance analytics that may be useful to data intensive problems in climate research. It offers an analysis paradigm that uses clusters of computers and combines distributed storage of large data sets with parallel computation. We are particularly interested in the potential of MapReduce to speed up basic operations common to a wide range of analyses. In order to evaluate this potential, we are prototyping a series of canonical MapReduce operations over a test suite of observational and climate simulation datasets. Our initial focus has been on averaging operations over arbitrary spatial and temporal extents within Modern Era Retrospective- Analysis for Research and Applications (MERRA) data. Preliminary results suggest this approach can improve efficiencies within data intensive analytic workflows.

A preliminary study for constructing a bioartificial liver device with induced pluripotent stem cell-derived hepatocytes

Directory of Open Access Journals (Sweden)

Iwamuro Masaya

2012-12-01

Full Text Available Abstract Background Bioartificial liver systems, designed to support patients with liver failure, are composed of bioreactors and functional hepatocytes. Immunological rejection of the embedded hepatocytes by the host immune system is a serious concern that crucially degrades the performance of the device. Induced pluripotent stem (iPS cells are considered a desirable source for bioartificial liver systems, because patient-derived iPS cells are free from immunological rejection. The purpose of this paper was to test the feasibility of a bioartificial liver system with iPS cell-derived hepatocyte-like cells. Methods Mouse iPS cells were differentiated into hepatocyte-like cells by a multi-step differentiation protocol via embryoid bodies and definitive endoderm. Differentiation of iPS cells was evaluated by morphology, PCR assay, and functional assays. iPS cell-derived hepatocyte-like cells were cultured in a bioreactor module with a pore size of 0.2 μm for 7 days. The amount of albumin secreted into the circulating medium was analyzed by ELISA. Additionally, after a 7-day culture in a bioreactor module, cells were observed by a scanning electron microscope. Results At the final stage of the differentiation program, iPS cells changed their morphology to a polygonal shape with two nucleoli and enriched cytoplasmic granules. Transmission electron microscope analysis revealed their polygonal shape, glycogen deposition in the cytoplasm, microvilli on their surfaces, and a duct-like arrangement. PCR analysis showed increased expression of albumin mRNA over the course of the differentiation program. Albumin and urea production was also observed. iPS-Heps culture in bioreactor modules showed the accumulation of albumin in the medium for up to 7 days. Scanning electron microscopy revealed the attachment of cell clusters to the hollow fibers of the module. These results indicated that iPS cells were differentiated into hepatocyte-like cells after culture

Site Characterization and Preliminary Performance Assessment Calculation Applied To JAEA-Horonobe URL Site of Japan

International Nuclear Information System (INIS)

Lim, Doo Hyun; Hatanaka, Koichiro; Ishii, Eiichi

2010-01-01

JAEA-Horonobe Underground Research Laboratory (URL) is designed for research and development on high-level radioactive waste (HLW) repository in sedimentary rock. For a potential HLW repository, understanding and implementing fracturing and faulting system, with data from the site characterization, into the performance assessment is essential because fracture and fault will be the major conductors or barriers for the groundwater flow and radionuclide release. The objectives are i) quantitative derivation of characteristics and correlation of fracturing/faulting system with geologic and geophysics data obtained from the site characterization, and ii) preliminary performance assessment calculation with characterized site information

Site Characterization and Preliminary Performance Assessment Calculation Applied To JAEA-Horonobe URL Site of Japan

Energy Technology Data Exchange (ETDEWEB)

Lim, Doo Hyun [NE Union Hill Road, Suite 200, WA 98052 (United States); Hatanaka, Koichiro; Ishii, Eiichi [Japan Atomic Energy Agency, Hokkaido (Japan)

2010-10-15

JAEA-Horonobe Underground Research Laboratory (URL) is designed for research and development on high-level radioactive waste (HLW) repository in sedimentary rock. For a potential HLW repository, understanding and implementing fracturing and faulting system, with data from the site characterization, into the performance assessment is essential because fracture and fault will be the major conductors or barriers for the groundwater flow and radionuclide release. The objectives are i) quantitative derivation of characteristics and correlation of fracturing/faulting system with geologic and geophysics data obtained from the site characterization, and ii) preliminary performance assessment calculation with characterized site information

Progress in static fourier transform infrared spectroscopy: assessment of sifti preliminary performances

Science.gov (United States)

Hébert, Philippe; Pierangelo, Clémence; Rosak, Alain; Cansot, Elodie; Bernard, Frédéric; Camy-Peyret, Claude

2017-11-01

The concept of static Fourier transform interferometry at thermal infrared wavelengths is well suited in the case of narrow spectral bands that are looked at for targeted molecular species as CO and O3 for pollution and air quality monitoring, or H20 and CO2 for weather forecast, down to the troposphere. It permits a high spectral resolution and a very good radiometric performance, with the advantage of a static interferometer, including no moving part. Along with other molecules sounded in the UV-VIS domain, as for instance in the TRAQ mission, SIFTI will provide scientists with a complete set for pollution measurements and air quality survey. Our paper presents the principles of static Fourier transform spectrometry, the work led on the instrument performance model and our study of the SIFTI instrument. We describe the instrument, its main dimensions and characteristics, and its architecture and major subsystems. We eventually make a preliminary survey of the SIFTI performance budget items. As a conclusion, we introduce the future CNES phase A study of this instrument that is started in 2006

Preliminary Evaluation Methodology of ECCS Performance for Design Basis LOCA Redefinition

International Nuclear Information System (INIS)

Kang, Dong Gu; Ahn, Seung Hoon; Seul, Kwang Won

2010-01-01

To improve their existing regulations, the USNRC has made efforts to develop the risk-informed and performance-based regulation (RIPBR) approaches. As a part of these efforts, the rule revision of 10CFR50.46 (ECCS Acceptance Criteria) is underway, considering some options for 4 categories of spectrum of break sizes, ECCS functional reliability, ECCS evaluation model, and ECCS acceptance criteria. Since the potential for safety benefits and unnecessary burden reduction from design basis LOCA redefinition is high relative to other options, the USNRC is proceeding with the rulemaking for design basis LOCA redefinition. An instantaneous break with a flow rate equivalent to a double ended guillotine break (DEGB) of the largest primary piping system in the plant is widely recognized as an extremely unlikely event, while redefinition of design basis LOCA can affect the existing regulatory practices and approaches. In this study, the status of the design basis LOCA redefinition and OECD/NEA SMAP (Safety Margin Action Plan) methodology are introduced. Preliminary evaluation methodology of ECCS performance for LOCA is developed and discussed for design basis LOCA redefinition

DEMONSTRATION OF FUEL CELLS TO RECOVER ENERGY FROM ANAEROBIC DIGESTER GAS - PHASE I. CONCEPTUAL DESIGN, PRELIMINARY COST, AND EVALUATION STUDY

Science.gov (United States)

The report discusses Phase I (a conceptual design, preliminary cost, and evaluation study) of a program to demonstrate the recovery of energy from waste methane produced by anaerobic digestion of waste water treatment sludge. The fuel cell is being used for this application becau...

A comparison of the recruitment of antibody forming cells in the nose and lung: Preliminary findings

Energy Technology Data Exchange (ETDEWEB)

King-Herbert, A P; Bice, D E; Harkema, J R

1988-12-01

Instillation of a particulate antigen into a selected lung lobe leads to an accumulation of antibody forming cells in the exposed lung lobe. Our goal in this preliminary study was to determine if an immune response could be elicited in the nasal mucosa of Beagle dogs exposed to a particulate antigen, and if so, to compare this immune response with that of the lungs when the nasal mucosa and the lungs are each immunized with a different particulate antigen. An Immune response was observed when the nasal mucosa was exposed to particulate antigen, but numbers of antibody-forming cells and levels of antibody in the nose were much lower than observed in an immunized lung lobe. (author)

A comparison of the recruitment of antibody forming cells in the nose and lung: Preliminary findings

International Nuclear Information System (INIS)

King-Herbert, A.P.; Bice, D.E.; Harkema, J.R.

1988-01-01

Instillation of a particulate antigen into a selected lung lobe leads to an accumulation of antibody forming cells in the exposed lung lobe. Our goal in this preliminary study was to determine if an immune response could be elicited in the nasal mucosa of Beagle dogs exposed to a particulate antigen, and if so, to compare this immune response with that of the lungs when the nasal mucosa and the lungs are each immunized with a different particulate antigen. An Immune response was observed when the nasal mucosa was exposed to particulate antigen, but numbers of antibody-forming cells and levels of antibody in the nose were much lower than observed in an immunized lung lobe. (author)

Accelerated stress testing of thin film solar cells: Development of test methods and preliminary results

Science.gov (United States)

Lathrop, J. W.

1985-01-01

If thin film cells are to be considered a viable option for terrestrial power generation their reliability attributes will need to be explored and confidence in their stability obtained through accelerated testing. Development of a thin film accelerated test program will be more difficult than was the case for crystalline cells because of the monolithic construction nature of the cells. Specially constructed test samples will need to be fabricated, requiring committment to the concept of accelerated testing by the manufacturers. A new test schedule appropriate to thin film cells will need to be developed which will be different from that used in connection with crystalline cells. Preliminary work has been started to seek thin film schedule variations to two of the simplest tests: unbiased temperature and unbiased temperature humidity. Still to be examined are tests which involve the passage of current during temperature and/or humidity stress, either by biasing in the forward (or reverse) directions or by the application of light during stress. Investigation of these current (voltage) accelerated tests will involve development of methods of reliably contacting the thin conductive films during stress.

A Cs-137 afterloading device. Preliminary results of cell kinetic effects of low dose-rate irradiation in an experimental tumour

International Nuclear Information System (INIS)

Rutgers, D.H.

1988-01-01

A Cs-137 afterloading technique is described which can be used in experimental tumours. Preliminary results, obtained with the human cervical carcinoma ME-180 xenografted to nude athymic mice, demonstrated that 20 Gy of low dose-rate irradiation induced an important redistribution of cells over cell cycle. The proportion of cells in G2-phase increased from 14.4% to 44.2% at 140 hours after irradiation. This method allows an accurate calculation of the dose-rate distribution in the tumour. Investigations of the cell kinetic effects of low dose-rate irradiation, at different dose-rates and different total doses, are therefore facilitated by the technique. (orig.) [de

Do district health systems perform differently because of their managers? Preliminary insights from Indonesia

Directory of Open Access Journals (Sweden)

Augustine Asante

2015-07-01

Full Text Available District health systems (DHS are central to the global efforts to improve health outcomes but many remain ineffective. In many lowresource settings, despite the generally weak DHS there is evidence that some districts consistently perform well against the odds, and this is often attributed to the calibre of managers leading such districts and their management and leadership (M&L skills. This paper examines the M&L practices of district health managers in high and low performing districts in Indonesia in an attempt to understand whether the differences in the performance of DHS can be explained, at least in part, by the differences in the performance of their health managers. We employed a mixed methods case study design focusing on two purposefully selected districts. Data were collected in 2011 using questionnaires and in-depth interviews. The preliminary results suggest that M&L practices of managers in the high and low performing districts are similar and provide little explanation for the differences in the performance of the two DHS. Contextual and health system factors offered a much better explanation for the variations in DHS performance.

Preliminary results about Electrodeposition of Cobalt at laboratory level

International Nuclear Information System (INIS)

Cornejo, N.

1992-01-01

As of an organic compound, an extraction and Cobalt electrodeposition method had been developed as a part of fabrication aim of a sealed radioactive source with objective to the construction of density meter prototype. It was performed preliminary test of electrodeposition in the laboratory level in a simple cell. The used electrolyte had been a sulphate solution obtained by extraction of an organic solution. It is obtained a Co film by electrodeposition at 55 o C temperature and with an approximately Co concentration in 70 g/lt. (Author) 3 refs., 1 fig., 1 tab

Instrumental concept and preliminary performances of SIFTI: static infrared fourier transform interferometer

Science.gov (United States)

Hébert, Philippe-Jean; Cansot, E.; Pierangelo, C.; Buil, C.; Bernard, F.; Loesel, J.; Trémas, T.; Perrin, L.; Courau, E.; Casteras, C.; Maussang, I.; Simeoni, D.

2017-11-01

The SIFTI (Static Infrared Fourier Transform Interferometer) instrument aims at supporting an important part in a mission for atmospheric pollution sounding from space, by providing high spectral resolution and high Signal to Noise Ratio spectra of the atmosphere. They will allow to resolve tropospheric profiles of ozone (03) and carbon monoxide (C0), especially down to the planetary boundary layer (PBL), an altitude region of very high interest, though poorly monitored to date, for air quality and pollution monitoring. The retrieved profile of ozone, resp. C0, will contain 5 to 7, resp. 2.5 to 4, independent pieces of information. The French space agency CNES (Centre National d'Etudes Spatiales) has proposed and is studying an instrument concept for SIFTI based on a static interferometer, where the needed optical path are generated by a pair of crossed staircase fixed mirrors (replacing the moving reflector of dynamic Fourier transform interferometers like IASI or MIPAS). With the SIFTI design, a very high spectral resolution ( 0.1 cm-1 apodised) is achieved in a very compact optical setup, allowing a large throughput, hence a high SNR. The measurements are performed in the 9.5 μm band for 03 and in the 4.6 μm band for C0. The science return of the sounder can be further increased if an "intelligent pointing" process is implemented. This consists in combining the TIR sounder with a companion TIR imager, providing information on the cloud coverage in the next observed scene. 0nboard, real-time analysis of the IR image is used to command the sounder staring mirror to cloud free areas, which will maximize the probability for probing down to the surface. After the first part of the phase A, the architecture of SIFTI was studied as a trade-off between performance and resource budget. We review the main architecture and functional choices, and their advantages. The preliminary instrument concept is then presented in its main aspects and in terms of main subsystem

Visual Assessment on Coastal Cruise Tourism: A Preliminary Planning Using Importance Performance Analysis

Science.gov (United States)

Trisutomo, S.

2017-07-01

Importance-Performance Analysis (IPA) has been widely applied in many cases. In this research, IPA was applied to measure perceive on coastal tourism objects and its possibility to be developed as coastal cruise tourism in Makassar. Three objects, i.e. Akkarena recreational site, Losari public space at waterfront, and Paotere traditional Phinisi ships port, were selected and assessed visually from water area by a group of purposive resource persons. The importance and performance of 10 attributes of each site were scored using Likert scale from 1 to 5. Data were processed by SPSS-21 than resulted Cartesian graph which the scores were divided in four quadrants: Quadrant I concentric here, Quadrant II keep up the good work, Quadrant III low priority, and Quadrant IV possible overkill. The attributes in each quadrant could be considered as the platform for preliminary planning of coastal cruise tour in Makassar

Preliminary test conditions for KNGR SBLOCA DVI ECCS performance test

International Nuclear Information System (INIS)

Bae, Kyoo Whan; Song, Jin Ho; Chung, Young Jong; Sim, Suk Ku; Park, Jong Kyun

1999-03-01

The Korean Next Generation Reactor (KNGR) adopts 4-train Direct Vessel Injection (DVI) configuration and injects the safety injection water directly into the downcomer through the 8.5'' DVI nozzle. Thus, the thermal hydraulic phenomena such as ECCS mixing and bypass are expected to be different from those observed in the cold leg injection. In order to investigate the realistic injection phenomena and modify the analysis code developed in the basis of cold leg injection, thermal hydraulic test with the performance evaluation is required. Preliminarily, the sequence of events and major thermal hydraulic phenomena during the small break LOCA for KNGR are identified from the analysis results calculated by the CEFLASH-4AS/REM. It is shown from the analysis results that the major transient behaviors including the core mixture level are largely affected by the downcomer modeling. Therefore, to investigate the proper thermal hydraulic phenomena occurring in the downcomer with limited budget and time, the separate effects test focusing on this region is considered to be effective and the conceptual test facility based on this recommended. For this test facility the test initial and boundary conditions are developed using the CEFLASH-4AS/REM analysis results that will be used as input for the preliminary test requirements. The final test requirements will be developed through the further discussions with the test performance group. (Author). 10 refs., 18 tabs., 4 figs

Investigation of the response of low-dose irradiated cells. Pt. 2. Radio-adaptive response of human embryonic cells is related to cell-to-cell communication

International Nuclear Information System (INIS)

Ishii, Keiichiro; Watanabe, Masami.

1994-01-01

To clarify the radio-adaptive response of normal cells to low-dose radiation, we irradiated human embryonic cells and HeLa cells with low-dose X-ray and examined the changes in sensitivity to subsequent high-dose X-irradiation. The results obtained were as follows; (1) When HE cells were irradiated by a high-dose of 200 cGy, the growth ratio of the living cells five days after the irradiation decreased to 37% of that of the cells which received no X-irradiation. When the cells received a preliminary irradiation of 10 to 20 cGy four hours before the irradiation of 200 cGy, the relative growth ratios increased significantly to 45-53%. (2) This preliminary irradiation effect was not observed in HeLa cells, being cancer cells. (3) When the HE cells suspended in a Ca 2+ iron-free medium or TPA added medium while receiving the preliminary irradiation of 13 cGy, the effect of the preliminary irradiation in increasing the relative growth ratio of living cells was not observed. (4) This indicates that normal cells shows an adaptive response to low-dose radiation and become more radioresistant. This phenomenon is considered to involve cell-to-cell communication maintained in normal cells and intracellular signal transduction in which Ca 2+ ion plays a role. (author)

Dendritic cell vaccines.

Science.gov (United States)

Mosca, Paul J; Lyerly, H Kim; Clay, Timothy M; Morse, Michael A; Lyerly, H Kim

2007-05-01

Dendritic cells are antigen-presenting cells that have been shown to stimulate tumor antigen-specific T cell responses in preclinical studies. Consequently, there has been intense interest in developing dendritic cell based cancer vaccines. A variety of methods for generating dendritic cells, loading them with tumor antigens, and administering them to patients have been described. In recent years, a number of early phase clinical trials have been performed and have demonstrated the safety and feasibility of dendritic cell immunotherapies. A number of these trials have generated valuable preliminary data regarding the clinical and immunologic response to DC-based immunotherapy. The emphasis of dendritic cell immunotherapy research is increasingly shifting toward the development of strategies to increase the potency of dendritic cell vaccine preparations.

Performance analysis of a potassium-base AMTEC cell

International Nuclear Information System (INIS)

Huang, C.; Hendricks, T.J.; Hunt, T.K.

1998-01-01

Sodium-BASE Alkali-Metal-Thermal-to-Electric-Conversion (AMTEC) cells have been receiving increased attention and funding from the Department of Energy, NASA and the United States Air Force. Recently, sodium-BASE (Na-BASE) AMTEC cells were selected for the Advanced Radioisotope Power System (ARPS) program for the next generation of deep-space missions and spacecraft. Potassium-BASE (K-BASE) AMTEC cells have not received as much attention to date, even though the vapor pressure of potassium is higher than that of sodium at the same temperature. So that, K-BASE AMTEC cells with potentially higher open circuit voltage and higher power output than Na-BASE AMTEC cells are possible. Because the surface tension of potassium is about half of the surface tension of sodium at the same temperature, the artery and evaporator design in a potassium AMTEC cell has much more challenging pore size requirements than designs using sodium. This paper uses a flexible thermal/fluid/electrical model to predict the performance of a K-BASE AMTEC cell. Pore sizes in the artery of K-BASE AMTEC cells must be smaller by an order of magnitude than in Na-BASE AMTEC cells. The performance of a K-BASE AMTEC cell was higher than a Na-BASE AMTEC cell at low voltages/high currents. K-BASE AMTEC cells also have the potential of much better electrode performance, thereby creating another avenue for potentially better performance in K-BASE AMTEC cells

Effect of compressive force on PEM fuel cell performance

Science.gov (United States)

MacDonald, Colin Stephen

Polymer electrolyte membrane (PEM) fuel cells possess the potential, as a zero-emission power source, to replace the internal combustion engine as the primary option for transportation applications. Though there are a number of obstacles to vast PEM fuel cell commercialization, such as high cost and limited durability, there has been significant progress in the field to achieve this goal. Experimental testing and analysis of fuel cell performance has been an important tool in this advancement. Experimental studies of the PEM fuel cell not only identify unfiltered performance response to manipulation of variables, but also aid in the advancement of fuel cell modelling, by allowing for validation of computational schemes. Compressive force used to contain a fuel cell assembly can play a significant role in how effectively the cell functions, the most obvious example being to ensure proper sealing within the cell. Compression can have a considerable impact on cell performance beyond the sealing aspects. The force can manipulate the ability to deliver reactants and the electrochemical functions of the cell, by altering the layers in the cell susceptible to this force. For these reasons an experimental study was undertaken, presented in this thesis, with specific focus placed on cell compression; in order to study its effect on reactant flow fields and performance response. The goal of the thesis was to develop a consistent and accurate general test procedure for the experimental analysis of a PEM fuel cell in order to analyse the effects of compression on performance. The factors potentially affecting cell performance, which were a function of compression, were identified as: (1) Sealing and surface contact; (2) Pressure drop across the flow channel; (3) Porosity of the GDL. Each factor was analysed independently in order to determine the individual contribution to changes in performance. An optimal degree of compression was identified for the cell configuration in

Preliminary Axial Flow Turbine Design and Off-Design Performance Analysis Methods for Rotary Wing Aircraft Engines. Part 1; Validation

Science.gov (United States)

Chen, Shu-cheng, S.

2009-01-01

For the preliminary design and the off-design performance analysis of axial flow turbines, a pair of intermediate level-of-fidelity computer codes, TD2-2 (design; reference 1) and AXOD (off-design; reference 2), are being evaluated for use in turbine design and performance prediction of the modern high performance aircraft engines. TD2-2 employs a streamline curvature method for design, while AXOD approaches the flow analysis with an equal radius-height domain decomposition strategy. Both methods resolve only the flows in the annulus region while modeling the impact introduced by the blade rows. The mathematical formulations and derivations involved in both methods are documented in references 3, 4 for TD2-2) and in reference 5 (for AXOD). The focus of this paper is to discuss the fundamental issues of applicability and compatibility of the two codes as a pair of companion pieces, to perform preliminary design and off-design analysis for modern aircraft engine turbines. Two validation cases for the design and the off-design prediction using TD2-2 and AXOD conducted on two existing high efficiency turbines, developed and tested in the NASA/GE Energy Efficient Engine (GE-E3) Program, the High Pressure Turbine (HPT; two stages, air cooled) and the Low Pressure Turbine (LPT; five stages, un-cooled), are provided in support of the analysis and discussion presented in this paper.

Preliminary design report for the NAC combined transport cask

International Nuclear Information System (INIS)

1990-04-01

Nuclear Assurance Corporation (NAC) is under contract to the United States Department of Energy (DOE) to design, license, develop and test models, and fabricate a prototype cask transportation system for nuclear spent fuel. The design of this combined transport (rail/barge) transportation system has been divided into two phases, a preliminary design phase and a final design phase. This Preliminary Design Package (PDP) describes the NAC Combined Transport Cask (NAC-CTC), the results of work completed during the preliminary design phase and identifies the additional detailed analyses, which will be performed during final design. Preliminary analytical results are presented in the appropriate sections and supplemented by summaries of procedures and assumptions for performing the additional detailed analyses of the final design. 60 refs., 1 fig., 2 tabs

Performance optimization of a PEM hydrogen-oxygen fuel cell

Energy Technology Data Exchange (ETDEWEB)

Sadiq Al-Baghdadi, Maher A.R. [Fuel Cell Research Center, International Energy and Environment Foundation, Al-Najaf, P.O.Box 39 (Iraq)

2013-07-01

The objective was to develop a semi-empirical model that would simulate the performance of proton exchange membrane (PEM) fuel cells without extensive calculations. A fuel cell mathematical module has been designed and constructed to determine the performance of a PEM fuel cell. The influence of some operating parameters on the performance of PEM fuel cell has been investigated using pure hydrogen on the anode side and oxygen on the cathode side. The present model can be used to investigate the influence of process variables for design optimization of fuel cells, stacks, and complete fuel cell power system. The possible mechanisms of the parameter effects and their interrelationships are discussed. In order to assess the validity of the developed model a real PEM fuel cell system has been used to generate experimental data. The comparison shows good agreements between the modelling results and the experimental data. The model is shown a very useful for estimating the performance of PEM fuel cell stacks and optimization of fuel cell system integration and operation.

Recent developments in the modeling of molten carbonate fuel cells

International Nuclear Information System (INIS)

Wilemski, G.

1984-01-01

Modeling of porous electrodes and overall performance of molten carbonate fuel cells is reviewed. Aspects needing improvement are discussed. Some preliminary results on internal methane reforming cells are presented. Successful modeling of molten carbonate fuel cells has been carried out at two levels. The first concerns the prediction of overall cell performance and performance decay, i.e., the calculation of current-voltage curves and their decay rates for various cell operating conditions. The second involves the determination of individual porous electrode performance, i.e., how the electrode overpotential is affected by pore structure, gas composition, degree of electrolyte fill, etc. Both levels are treated mechanistically, as opposed to empirically, using fundamental mathematical descriptions of the relevant physical and chemical phenomena, in order to provide quantitative predictive capability

Preliminary design report for the prototypical fuel rod consolidation system

International Nuclear Information System (INIS)

Rosa, J.M.

1986-01-01

This report documents NUTECH's preliminary design of a dry, spent fuel rod consolidation system. This preliminary design is the result of Phase I of a planned four phase project. The present report on this project provides a considerable amount of detail for a preliminary design effort. The design and all of its details are described in this Preliminary Design Report (PDR). The NUTECH dry rod consolidation system described herein is remotely operated. It provides for automatic operation, but with operator hold points between key steps in the process. The operator has the ability to switch to a manual operation mode at any point in the process. The system is directed by the operator using an executive computer which controls and coordinates the operation of the in-cell equipment. The operator monitors the process using an in-cell closed circuit television (CCTV) system with audio output and equipment status displays on the computer monitor. The in-cell mechanical equipment consists of the following: (1) two overhead cranes with manipulators; (2) a multi-degree of freedom fuel handling table and its clamping equipment; (3) a fuel assembly end fitting removal station and its tools; (4) a consolidator (which pulls rods, assembles the consolidated bundle and loads the canister); (5) a canister end cap welder and weld inspection system; (6) decontamination systems; and (7) the CCTV and microphone systems

Preliminary design study of the TMT Telescope structure system: overview

Science.gov (United States)

Usuda, Tomonori; Ezaki, Yutaka; Kawaguchi, Noboru; Nagae, Kazuhiro; Kato, Atsushi; Takaki, Junji; Hirano, Masaki; Hattori, Tomoya; Tabata, Masaki; Horiuchi, Yasushi; Saruta, Yusuke; Sofuku, Satoru; Itoh, Noboru; Oshima, Takeharu; Takanezawa, Takashi; Endo, Makoto; Inatani, Junji; Iye, Masanori; Sadjadpour, Amir; Sirota, Mark; Roberts, Scott; Stepp, Larry

2014-07-01

We present an overview of the preliminary design of the Telescope Structure System (STR) of Thirty Meter Telescope (TMT). NAOJ was given responsibility for the TMT STR in early 2012 and engaged Mitsubishi Electric Corporation (MELCO) to take over the preliminary design work. MELCO performed a comprehensive preliminary design study in 2012 and 2013 and the design successfully passed its Preliminary Design Review (PDR) in November 2013 and April 2014. Design optimizations were pursued to better meet the design requirements and improvements were made in the designs of many of the telescope subsystems as follows: 1. 6-legged Top End configuration to support secondary mirror (M2) in order to reduce deformation of the Top End and to keep the same 4% blockage of the full aperture as the previous STR design. 2. "Double Lower Tube" of the elevation (EL) structure to reduce the required stroke of the primary mirror (M1) actuators to compensate the primary mirror cell (M1 Cell) deformation caused during the EL angle change in accordance with the requirements. 3. M1 Segment Handling System (SHS) to be able to make removing and installing 10 Mirror Segment Assemblies per day safely and with ease over M1 area where access of personnel is extremely difficult. This requires semi-automatic sequence operation and a robotic Segment Lifting Fixture (SLF) designed based on the Compliance Control System, developed for controlling industrial robots, with a mechanism to enable precise control within the six degrees of freedom of position control. 4. CO2 snow cleaning system to clean M1 every few weeks that is similar to the mechanical system that has been used at Subaru Telescope. 5. Seismic isolation and restraint systems with respect to safety; the maximum acceleration allowed for M1, M2, tertiary mirror (M3), LGSF, and science instruments in 1,000 year return period earthquakes are defined in the requirements. The Seismic requirements apply to any EL angle, regardless of the

Performance optimization of a PEM hydrogen-oxygen fuel cell

OpenAIRE

Maher A.R. Sadiq Al-Baghdadi

2013-01-01

The objective was to develop a semi-empirical model that would simulate the performance of proton exchange membrane (PEM) fuel cells without extensive calculations. A fuel cell mathematical module has been designed and constructed to determine the performance of a PEM fuel cell. The influence of some operating parameters on the performance of PEM fuel cell has been investigated using pure hydrogen on the anode side and oxygen on the cathode side. The present model can be used to investigate t...

Comments on SKB's SFL 3-5 preliminary performance assessment

International Nuclear Information System (INIS)

Wilmot, R.D.; Crawford, M.B.

2000-01-01

Recently introduced regulations in Sweden have established an individual risk criterion ( -6 per year) for the long-term performance of repositories for the disposal of radioactive wastes. SKB has not focused its assessment of SFL 3-5 on demonstrating compliance with this regulation. Instead, SKB has calculated individual dose and provided a comparison with an annual individual dose of 14 iSv (derived from the risk criteria using the ICRP's dose-risk conversion factor of 0.073 per Sv). The justification of this approach is that probabilities do not need to be determined if doses are less than the dose equivalent to the risk criterion. However, there is insufficient information regarding uncertainty provided in the documentation of the SFL 3-5 assessment to determine whether this approach is reasonable. SKB's parallel assessment of a repository for spent fuel using the KBS-3 concept (SR 97) accounts for uncertainty by specifying a 'reasonable' and a 'pessimistic' value for uncertain parameters in the assessment calculations. Although there are problems with the way probabilities have been assigned to these values, this approach does indicate where there are significant uncertainties. The SFL 3-5 PA does not include a structured approach to defining uncertainty, although a number of assumptions and parameter values are stated to be conservative. As a preliminary assessment, there is insufficient information to identify key uncertainties or sensitivities, or to determine where further work should be focused. Any assessment requires the use of expert judgement to determine how the assessment is conducted, what modelling approach to use, what features, events and processes (FEPs) could potentially affect the disposal system, which FEPs should be included in the conceptual models, and which scenarios should be assessed. Judgements are also required in determining how to parameterize the models, and this may extend to formal expert elicitation for particular parameter

Preliminary report for the license of a hot cell that will be use in the technology development for the obtention of Mo-99

International Nuclear Information System (INIS)

Fucugauchi, L.A.; Millan S, S.; Lopez M, A.E.; Lopez C, R; Sanchez M, V.; Reynoso V, R.; Vera, A.

1991-05-01

A preliminary report for the license of a hot cell that will be used in the development of the technology for the obtaining of Mo-99 is presented. The following topics are also included: objective of the project, technical description, description of the prototype cell, handling of radioactive wastes, lists of equipment that will be used, risk analysis, curricula, quality assurance plan and an annex with the report on handling of radioactive wastes presented to the PAGD-IAEA. (Author)

Performance evaluation of an air-breathing high-temperature proton exchange membrane fuel cell

International Nuclear Information System (INIS)

Wu, Qixing; Li, Haiyang; Yuan, Wenxiang; Luo, Zhongkuan; Wang, Fang; Sun, Hongyuan; Zhao, Xuxin; Fu, Huide

2015-01-01

Highlights: • An air-breathing HT-PEMFC was designed and evaluated experimentally. • The peak power density of the air-breathing HT-PEMFC was 220.5 mW cm"−"2 at 200 °C. • Break-in behavior and effects of temperature and anodic stoichiometry were studied. • The effect of cell orientations on the performance was investigated. • The degradation rate of the air-breathing HT-PEMFC was around 58.32 μV h"−"1. - Abstract: The air-breathing proton exchange membrane fuel cell (PEMFC) is of great interest in mobile power sources because of its simple system design and low parasitic power consumption. Different from previous low-temperature air-breathing PEMFCs, a high-temperature PEMFC with a phosphoric acid doped polybenzimidazole (PBI) membrane as the polymer electrolyte is designed and investigated under air-breathing conditions. The preliminary results show that a peak power density of 220.5 mW cm"−"2 at 200 °C can be achieved without employing any water managements, which is comparable to those with conventional Nafion® membranes operated at low temperatures. In addition, it is found that with the present cell design, the limiting current density arising from the oxygen transfer limitation is around 700 mA cm"−"2 even at 200 °C. The short-term durability test at 200 mA cm"−"2 and 180 °C reveals that all the cells exhibit a gradual decrease in the voltage along with a rise in the internal resistance. The degradation rate of continuous operation is around 58.32 μV h"−"1, which is much smaller than those of start/stop cycling operations.

Preliminary environmental site assessments in New York City

International Nuclear Information System (INIS)

Lundy, P.; Gasson, D.R.; Longendyke, S.T.

1991-01-01

Preliminary Environmental Site Assessments are often performed prior to real estate transactions or refinancing. These assessments are typically performed for real estate buyers, sellers and lending institutions. Undertaking a Preliminary Environmental Site Assessment in New York City can often be quite complex and time-consuming. This is due, in part, to the age and density of buildings in the city as well as the myriad of regulatory agencies with jurisdiction over environmental issues. This paper will discuss how environmental assessments are performed with a special emphasis on building in New York City. In includes hazardous wastes management for Radon, PCB's and asbestos

Lessons learned from the preliminary performance assessment exercise for the Vienne site strategies for investigating the granodiorite confinement capability

International Nuclear Information System (INIS)

Lebon, P.

1999-01-01

One of the three sites under study by ANDRA is located on the Poitou shoal in the Vienne Department. The granitic basement rock is overlain by a 160 m thick layer of Jurassic sediments containing two seasonally pumped aquifers. The preliminary hydrogeological model of the granitic basement assumed that regional flow is SE-NW, and circulates in the hecto-metric fractures, and that groundwater flow velocity is very low. A preliminary performance assessment exercise focusing on the geological barrier was carried out based on these assumptions and a disposal concept where radwaste is stored in separate granodiorite 'blocks' delimited by the water-bearing fractures. As regards of the granodioritic blocks, the programme goals include analysing of detailed structure, obtaining uncontaminated samples of interstitial ground water in order to determine its physicochemical properties and evaluating transport and retention parameters. (author)

Performance characterization of solid oxide cells under high pressure

DEFF Research Database (Denmark)

Sun, Xiufu; Bonaccorso, Alfredo Damiano; Graves, Christopher R.

2014-01-01

in both fuel cell mode and electrolysis mode. In electrolysis mode at low current density, the performance improvement was counteracted by the increase in open circuit voltage, but it has to be born in mind that the pressurised gas contains higher molar free energy. Operating at high current density...... hydrocarbon fuels, which is normally performed at high pressure to achieve a high yield. Operation of SOECs at elevated pressure will therefore facilitate integration with the downstream fuel synthesis and is furthermore advantageous as it increases the cell performance. In this work, recent pressurised test...... results of a planar Ni-YSZ (YSZ: Yttria stabilized Zirconia) supported solid oxide cell are presented. The test was performed at 800 °C at pressures up to 15 bar. A comparison of the electrochemical performance of the cell at 1 and 3 bar shows a significant and equal performance gain at higher pressure...

Five-Kilometers Time Trial: Preliminary Validation of a Short Test for Cycling Performance Evaluation.

Science.gov (United States)

Dantas, Jose Luiz; Pereira, Gleber; Nakamura, Fabio Yuzo

2015-09-01

The five-kilometer time trial (TT5km) has been used to assess aerobic endurance performance without further investigation of its validity. This study aimed to perform a preliminary validation of the TT5km to rank well-trained cyclists based on aerobic endurance fitness and assess changes of the aerobic endurance performance. After the incremental test, 20 cyclists (age = 31.3 ± 7.9 years; body mass index = 22.7 ± 1.5 kg/m(2); maximal aerobic power = 360.5 ± 49.5 W) performed the TT5km twice, collecting performance (time to complete, absolute and relative power output, average speed) and physiological responses (heart rate and electromyography activity). The validation criteria were pacing strategy, absolute and relative reliability, validity, and sensitivity. Sensitivity index was obtained from the ratio between the smallest worthwhile change and typical error. The TT5km showed high absolute (coefficient of variation 0.95) reliability of performance variables, whereas it presented low reliability of physiological responses. The TT5km performance variables were highly correlated with the aerobic endurance indices obtained from incremental test (r > 0.70). These variables showed adequate sensitivity index (> 1). TT5km is a valid test to rank the aerobic endurance fitness of well-trained cyclists and to differentiate changes on aerobic endurance performance. Coaches can detect performance changes through either absolute (± 17.7 W) or relative power output (± 0.3 W.kg(-1)), the time to complete the test (± 13.4 s) and the average speed (± 1.0 km.h(-1)). Furthermore, TT5km performance can also be used to rank the athletes according to their aerobic endurance fitness.

Preliminary performance assessment for the Waste Isolation Pilot Plant, December 1992. Vol. 1: Third comparison with 40 CFR 191, Subpart B

Energy Technology Data Exchange (ETDEWEB)

NONE

1992-12-15

Before disposing of transuranic radioactive wastes in the Waste Isolation Pilot Plant (WIPP), the United States Department of Energy (DOE) must evaluate compliance with applicable long-term regulations of the United States Environmental Protection Agency (EPA). Sandia National Laboratories is conducting iterative performance assessments of the WIPP for the DOE to provide interim guidance while preparing for final compliance evaluations. This volume contains an overview of WIPP performance assessment and a preliminary comparison with the long-term requirements of the Environmental Radiation Protection Standards for Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes (40 CFR 191, Subpart B). Detailed information about the technical basis for the preliminary comparison is contained in Volume 2. The reference data base and values for input parameters used in the modeling system are contained in Volume 3. Uncertainty and sensitivity analyses related to 40 CFR 191B are contained in Volume 4. Volume 5 contains uncertainty and sensitivity analyses of gas and brine migration for undisturbed performance. Finally, guidance derived from the entire 1992 performance assessment is presented in Volume 6. Results of the 1992 performance assessment are preliminary, and are not suitable for final comparison with 40 CFR 191, Subpart B. Portions of the modeling system and the data base remain incomplete, and the level of confidence in the performance estimates is not sufficient for a defensible compliance evaluation. Results are, however, suitable for providing guidance to the WIPP Project. All results are conditional on the models and data used, and are presented for preliminary comparison to the Containment Requirements of 40 CFR 191, Subpart B as mean complementary cumulative distribution functions (CCDFs) displaying estimated probabilistic releases of radionuclides to the accessible environment. Results compare three conceptual models for

Preliminary performance assessment for the Waste Isolation Pilot Plant, December 1992. Vol. 1: Third comparison with 40 CFR 191, Subpart B

International Nuclear Information System (INIS)

1992-12-01

Before disposing of transuranic radioactive wastes in the Waste Isolation Pilot Plant (WIPP), the United States Department of Energy (DOE) must evaluate compliance with applicable long-term regulations of the United States Environmental Protection Agency (EPA). Sandia National Laboratories is conducting iterative performance assessments of the WIPP for the DOE to provide interim guidance while preparing for final compliance evaluations. This volume contains an overview of WIPP performance assessment and a preliminary comparison with the long-term requirements of the Environmental Radiation Protection Standards for Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes (40 CFR 191, Subpart B). Detailed information about the technical basis for the preliminary comparison is contained in Volume 2. The reference data base and values for input parameters used in the modeling system are contained in Volume 3. Uncertainty and sensitivity analyses related to 40 CFR 191B are contained in Volume 4. Volume 5 contains uncertainty and sensitivity analyses of gas and brine migration for undisturbed performance. Finally, guidance derived from the entire 1992 performance assessment is presented in Volume 6. Results of the 1992 performance assessment are preliminary, and are not suitable for final comparison with 40 CFR 191, Subpart B. Portions of the modeling system and the data base remain incomplete, and the level of confidence in the performance estimates is not sufficient for a defensible compliance evaluation. Results are, however, suitable for providing guidance to the WIPP Project. All results are conditional on the models and data used, and are presented for preliminary comparison to the Containment Requirements of 40 CFR 191, Subpart B as mean complementary cumulative distribution functions (CCDFs) displaying estimated probabilistic releases of radionuclides to the accessible environment. Results compare three conceptual models for

Performance of multi-junction cells due to illumination distribution across the cell surface

International Nuclear Information System (INIS)

Schultz, R.D.; Vorster, F.J; Dyk, E.E van

2012-01-01

This paper addresses the influence of illumination distribution on the performance of a high concentration photovoltaic (HCPV) module. CPV systems comprise of optical elements as well as mechanical tracking to concentrate the solar flux onto the solar receiver as well as to keep the system on track with the sun. The performance of the subcells of the multi-junction concentrator cell depends on the optical alignment of the system. Raster scanning of the incident intensity in the optical plane of the receiver and corresponding I–V measurements were used to investigate the influence of illumination distribution on performance. The results show that the illumination distribution that differs between cells does affect the performance of the module. The performance of the subcells of the multi-junction concentrator cell also depends on the optical alignment of the system.

Performance of multi-junction cells due to illumination distribution across the cell surface

Energy Technology Data Exchange (ETDEWEB)

Schultz, R.D., E-mail: s206029578@live.nmmu.ac.za [Nelson Mandela University, Physics Department, P.O. Box 77000, 6031, Port Elizabeth (South Africa); Vorster, F.J; Dyk, E.E van [Nelson Mandela University, Physics Department, P.O. Box 77000, 6031, Port Elizabeth (South Africa)

2012-05-15

This paper addresses the influence of illumination distribution on the performance of a high concentration photovoltaic (HCPV) module. CPV systems comprise of optical elements as well as mechanical tracking to concentrate the solar flux onto the solar receiver as well as to keep the system on track with the sun. The performance of the subcells of the multi-junction concentrator cell depends on the optical alignment of the system. Raster scanning of the incident intensity in the optical plane of the receiver and corresponding I-V measurements were used to investigate the influence of illumination distribution on performance. The results show that the illumination distribution that differs between cells does affect the performance of the module. The performance of the subcells of the multi-junction concentrator cell also depends on the optical alignment of the system.

Gold-silica nanocomposites for the detection of human ovarian cancer cells: a preliminary study

International Nuclear Information System (INIS)

Mishra, Y K; Mohapatra, S; Avasthi, D K; Kabiraj, D; Lalla, N P; Pivin, J C; Sharma, Himani; Kar, Rajarshi; Singh, Neeta

2007-01-01

We report the structural and optical properties of Au nanoparticles embedded in a silica matrix synthesized by atom beam co-sputtering. The presence of surface plasmon resonant absorption indicates the formation of Au nanoparticles. Transmission electron microscopy (TEM) studies show the presence of Au nanoparticles with an average size ranging from ∼1.8 to 5.4 nm with narrow size distributions depending on the relative areas of Au and SiO 2 . We discuss the process of nucleation and growth of Au nanoparticles in the nanocomposite films formed by co-sputtering. The present method of nanoparticle synthesis is compared with other ion beam based techniques such as ion implantation and ion beam mixing. Preliminary experiments for the detection of human ovarian cancer cells using these Au nanoparticles are described

Theoretical performance of hydrogen-bromine rechargeable SPE fuel cell

Science.gov (United States)

Savinell, Robert F.; Fritts, S. D.

1987-01-01

A mathematical model was formulated to describe the performance of a hydrogen-bromine fuel cell. Porous electrode theory was applied to the carbon felt flow-by electrode and was coupled to theory describing the solid polymer electrolyte (SPE) system. Parametric studies using the numerical solution to this model were performed to determine the effect of kinetic, mass transfer, and design parameters on the performance of the fuel cell. The results indicate that the cell performance is most sensitive to the transport properties of the SPE membrane. The model was also shown to be a useful tool for scale-up studies.

Accelerated stress testing of amorphous silicon solar cells

Science.gov (United States)

Stoddard, W. G.; Davis, C. W.; Lathrop, J. W.

1985-01-01

A technique for performing accelerated stress tests of large-area thin a-Si solar cells is presented. A computer-controlled short-interval test system employing low-cost ac-powered ELH illumination and a simulated a-Si reference cell (seven individually bandpass-filtered zero-biased crystalline PIN photodiodes) calibrated to the response of an a-Si control cell is described and illustrated with flow diagrams, drawings, and graphs. Preliminary results indicate that while most tests of a program developed for c-Si cells are applicable to a-Si cells, spurious degradation may appear in a-Si cells tested at temperatures above 130 C.

An Algorithm for Glaucoma Screening in Clinical Settings and Its Preliminary Performance Profile

Directory of Open Access Journals (Sweden)

S-Farzad Mohammadi

2013-01-01

Full Text Available Purpose: To devise and evaluate a screening algorithm for glaucoma in clinical settings. Methods: Screening included examination of the optic disc for vertical cupping (≥0.4 and asymmetry (≥0.15, Goldmann applanation tonometry (≥21 mmHg, adjusted or unadjusted for central corneal thickness, and automated perimetry. In the diagnostic step, retinal nerve fiber layer imaging was performed using scanning laser polarimetry. Performance of the screening protocol was assessed in an eye hospital-based program in which 124 non-physician personnel aged 40 years or above were examined. A single ophthalmologist carried out the examinations and in equivocal cases, a glaucoma subspecialist′s opinion was sought. Results: Glaucoma was diagnosed in six cases (prevalence 4.8%; 95% confidence interval, 0.01-0.09 of whom five were new. The likelihood of making a definite diagnosis of glaucoma for those who were screened positively was 8.5 times higher than the estimated baseline risk for the reference population; the positive predictive value of the screening protocol was 30%. Screening excluded 80% of the initial population. Conclusion: Application of a formal screening protocol (such as our algorithm or its equivalent in clinical settings can be helpful in detecting new cases of glaucoma. Preliminary performance assessment of the algorithm showed its applicability and effectiveness in detecting glaucoma among subjects without any visual complaint.

Performance of the ACWA Pilot Immobilized Cell Bioreactor in Degradation of HD and Tetrytol Payloads of the M60 Chemical Round

National Research Council Canada - National Science Library

Guelta, Mark A; Chester, Nancy A; Kurnas, Carl W; Haley, Mark V; Lupton, F. S; Koch, Mark

2002-01-01

.... Neutralization followed by biodegradation was one technology identified as having potential. Guelta and DeFrank conducted preliminary laboratory studies using 1-liter Immobilized Cell Bioreactors (ICB...

Break-in and Performance Issues on a single cell PBI-based PEM Fuel Cell

DEFF Research Database (Denmark)

Kær, Søren Knudsen; Jespersen, Jesper Lebæk

of the fuel cell, even though break-in of a fuel cell implemented in a commercial application would most likely not be feasible. In the present work a commercially available PBI-based high temperature MEA is subject to a break-in procedure, as specified by the manufacturer. The cell was operated at 160 °C...... during the break-in procedure at a current density of 0.2 A/cm2. The performance of the cell was measured over the 100 hour break-in period and a polarization curve was recorded after completion of break-in. The performance change was minimal during the break-in cycle. However, in the first hour of op......-eration a significant performance decrease of 30 mV was observed. Hereafter a performance in-crease started and the overall performance change during the break-in procedure was a voltage in-crease of 35 mV corresponding to a rate of 240 μV/hr. The performance increase was however fast-est in the first 50 hours...

DOE Hydrogen & Fuel Cell Overview

Science.gov (United States)

2011-01-13

AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) U.S. Department of Energy...Overview of Combined Heat+Power PowerElectricity Natural Gas Heat + Cooling Natural Gas or Biogas ...Fuel Cell Technologies Program eere.energy.gov Source: US DOE 10/2010 Biogas Benefits: Preliminary Analysis Stationary fuel

Preliminary design of a tandem mirror reactor

International Nuclear Information System (INIS)

Strohmayer, J.N.

1984-04-01

The purpose of this thesis is to examine the TARA mirror experiment as a possible tandem mirror reactor configuration. This is a preliminary study to size the coil structure based on using the smallest end cell axial length that physics and engineering allow, zeroing the central cell parallel currents and having interchange stability. The input powers are estimated for the final reactor design so a Q value may be estimated. The Q value is defined as the fusion power divided by the total injected power absorbed by the plasma. A computer study was performed on the effect of the transition size, the transition vertical spacing and transition current. These parameters affect the central cell parallel currents, the recircularization of the flux tube and the ratio of central cell beta to anchor beta needed for marginal stability. Two designs were identified. The first uses 100 keV and 13 keV neutral beams to pump the ions that trap in the thermal barrier. The Q value of this reactor is 11.3. The second reactor uses a pump beam at 40 keV. This energy is chosen because there is a resonance for the charge exchange cross section between D 0 and He 2+ at this energy, thus the alpha ash will be pumped along with the deuterium and tritium. The Q value of this reactor is 11.6

Correlation between impurities, defects and cell performance in semicrystalline silicon

International Nuclear Information System (INIS)

Doolittle, W.A.; Rohatgi, A.

1990-01-01

This paper reports that an in-depth analysis of Solarex CDS semicrystalline silicon has been performed and correlations between the efficiency and impurities, and defects present in the material have been made. Comparisons were made between cell performance and variations in interstitial oxygen, substitutional carbon, grain size, etch pit density, and trap location as a function of position in the ingot. The oxygen concentration was found to decrease with increasing distance from the bottom of the ingot while the carbon concentration as well as average grain size was found to increase. The best cell performance was obtained on wafers with minimum oxygen and maximum carbon (top). No correlation was found between etch pit density and cell performance. DLTS and JVT measurements revealed that samples with higher oxygen content (bottom) gave lower cell performance due to a large number of distributed states, possibly due to extended defects like oxygen precipitates. Low oxygen samples (top) showed predominately discrete states, improved cell performance and a doping dependent average trap density

Solid Polymer Fuel Cells. Electrode and membrane performance studies

Energy Technology Data Exchange (ETDEWEB)

Moeller-Holst, S.

1996-12-31

This doctoral thesis studies aspects of fuel cell preparation and performance. The emphasis is placed on preparation and analysis of low platinum-loading solid polymer fuel cell (SPEC) electrodes. A test station was built and used to test cells within a wide range of real operating conditions, 40-150{sup o}C and 1-10 bar. Preparation and assembling equipment for single SPFCs was designed and built, and a new technique of spraying the catalyst layer directly onto the membrane was successfully demonstrated. Low Pt-loading electrodes (0.1 mg Pt/cm{sup 2}) prepared by the new technique exhibited high degree of catalyst utilization. The performance of single cells holding these electrodes is comparable to state-of-the-art SPFCs. Potential losses in single cell performance are ascribed to irreversibilities by analysing the efficiency of the Solid Oxide Fuel Cell by means of the second law of thermodynamics. The water management in membranes is discussed for a model system and the results are relevant to fuel cell preparation and performance. The new spray deposition technique should be commercially interesting as it involves few steps as well as techniques that are adequate for larger scale production. 115 refs., 43 figs., 18 tabs.

Solid Polymer Fuel Cells. Electrode and membrane performance studies

Energy Technology Data Exchange (ETDEWEB)

Moeller-Holst, S

1997-12-31

This doctoral thesis studies aspects of fuel cell preparation and performance. The emphasis is placed on preparation and analysis of low platinum-loading solid polymer fuel cell (SPEC) electrodes. A test station was built and used to test cells within a wide range of real operating conditions, 40-150{sup o}C and 1-10 bar. Preparation and assembling equipment for single SPFCs was designed and built, and a new technique of spraying the catalyst layer directly onto the membrane was successfully demonstrated. Low Pt-loading electrodes (0.1 mg Pt/cm{sup 2}) prepared by the new technique exhibited high degree of catalyst utilization. The performance of single cells holding these electrodes is comparable to state-of-the-art SPFCs. Potential losses in single cell performance are ascribed to irreversibilities by analysing the efficiency of the Solid Oxide Fuel Cell by means of the second law of thermodynamics. The water management in membranes is discussed for a model system and the results are relevant to fuel cell preparation and performance. The new spray deposition technique should be commercially interesting as it involves few steps as well as techniques that are adequate for larger scale production. 115 refs., 43 figs., 18 tabs.

What Happens Inside a Fuel Cell? Developing an Experimental Functional Map of Fuel Cell Performance

KAUST Repository

Brett, Daniel J. L.

2010-08-20

Fuel cell performance is determined by the complex interplay of mass transport, energy transfer and electrochemical processes. The convolution of these processes leads to spatial heterogeneity in the way that fuel cells perform, particularly due to reactant consumption, water management and the design of fluid-flow plates. It is therefore unlikely that any bulk measurement made on a fuel cell will accurately represent performance at all parts of the cell. The ability to make spatially resolved measurements in a fuel cell provides one of the most useful ways in which to monitor and optimise performance. This Minireview explores a range of in situ techniques being used to study fuel cells and describes the use of novel experimental techniques that the authors have used to develop an \\'experimental functional map\\' of fuel cell performance. These techniques include the mapping of current density, electrochemical impedance, electrolyte conductivity, contact resistance and CO poisoning distribution within working PEFCs, as well as mapping the flow of reactant in gas channels using laser Doppler anemometry (LDA). For the high-temperature solid oxide fuel cell (SOFC), temperature mapping, reference electrode placement and the use of Raman spectroscopy are described along with methods to map the microstructural features of electrodes. The combination of these techniques, applied across a range of fuel cell operating conditions, allows a unique picture of the internal workings of fuel cells to be obtained and have been used to validate both numerical and analytical models. © 2010 Wiley-VCH Verlag GmbH& Co. KGaA, Weinheim.

Space reactor preliminary mechanical design

International Nuclear Information System (INIS)

Meier, K.L.

1983-01-01

An analysis was performed on the SABRE reactor space power system to determine the effect of the number and size of heat pipes on the design parameters of the nuclear subsystem. Small numbers of thin walled heat pipes were found to give a lower subsystem mass, but excessive fuel swelling resulted. The SP-100 preliminary design uses 120 heat pipes because of acceptable fuel swelling and a minimum nuclear subsystem mass of 1875 kg. Salient features of the reactor preliminary design are: individual fuel modules, ZrO 2 block core mounts, bolted collar fuel module restraints, and a BeO central plug

A novel direct carbon fuel cell by approach of tubular solid oxide fuel cells

Energy Technology Data Exchange (ETDEWEB)

Liu, Renzhu; Zhao, Chunhua; Li, Junliang; Zeng, Fanrong; Wang, Shaorong; Wen, Tinglian; Wen, Zhaoyin [CAS Key Laboratory of Materials for Energy Conversion, Shanghai Inorganic Energy Materials and Power Source Engineering Center, Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS), 1295 Dingxi Road, Shanghai 200050 (China)

2010-01-15

A direct carbon fuel cell based on a conventional anode-supported tubular solid oxide fuel cell, which consisted of a NiO-YSZ anode support tube, a NiO-ScSZ anode functional layer, a ScSZ electrolyte film, and a LSM-ScSZ cathode, has been successfully achieved. It used the carbon black as fuel and oxygen as the oxidant, and a preliminary examination of the DCFC has been carried out. The cell generated an acceptable performance with the maximum power densities of 104, 75, and 47 mW cm{sup -2} at 850, 800, and 750 C, respectively. These results demonstrate the feasibility for carbon directly converting to electricity in tubular solid oxide fuel cells. (author)

Modelling fuel cell performance using artificial intelligence

Science.gov (United States)

Ogaji, S. O. T.; Singh, R.; Pilidis, P.; Diacakis, M.

Over the last few years, fuel cell technology has been increasing promisingly its share in the generation of stationary power. Numerous pilot projects are operating worldwide, continuously increasing the amount of operating hours either as stand-alone devices or as part of gas turbine combined cycles. An essential tool for the adequate and dynamic analysis of such systems is a software model that enables the user to assess a large number of alternative options in the least possible time. On the other hand, the sphere of application of artificial neural networks has widened covering such endeavours of life such as medicine, finance and unsurprisingly engineering (diagnostics of faults in machines). Artificial neural networks have been described as diagrammatic representation of a mathematical equation that receives values (inputs) and gives out results (outputs). Artificial neural networks systems have the capacity to recognise and associate patterns and because of their inherent design features, they can be applied to linear and non-linear problem domains. In this paper, the performance of the fuel cell is modelled using artificial neural networks. The inputs to the network are variables that are critical to the performance of the fuel cell while the outputs are the result of changes in any one or all of the fuel cell design variables, on its performance. Critical parameters for the cell include the geometrical configuration as well as the operating conditions. For the neural network, various network design parameters such as the network size, training algorithm, activation functions and their causes on the effectiveness of the performance modelling are discussed. Results from the analysis as well as the limitations of the approach are presented and discussed.

Modelling fuel cell performance using artificial intelligence

Energy Technology Data Exchange (ETDEWEB)

Ogaji, S.O.T.; Singh, R.; Pilidis, P.; Diacakis, M. [Power Propulsion and Aerospace Engineering Department, Centre for Diagnostics and Life Cycle Costs, Cranfield University (United Kingdom)

2006-03-09

Over the last few years, fuel cell technology has been increasing promisingly its share in the generation of stationary power. Numerous pilot projects are operating worldwide, continuously increasing the amount of operating hours either as stand-alone devices or as part of gas turbine combined cycles. An essential tool for the adequate and dynamic analysis of such systems is a software model that enables the user to assess a large number of alternative options in the least possible time. On the other hand, the sphere of application of artificial neural networks has widened covering such endeavours of life such as medicine, finance and unsurprisingly engineering (diagnostics of faults in machines). Artificial neural networks have been described as diagrammatic representation of a mathematical equation that receives values (inputs) and gives out results (outputs). Artificial neural networks systems have the capacity to recognise and associate patterns and because of their inherent design features, they can be applied to linear and non-linear problem domains. In this paper, the performance of the fuel cell is modelled using artificial neural networks. The inputs to the network are variables that are critical to the performance of the fuel cell while the outputs are the result of changes in any one or all of the fuel cell design variables, on its performance. Critical parameters for the cell include the geometrical configuration as well as the operating conditions. For the neural network, various network design parameters such as the network size, training algorithm, activation functions and their causes on the effectiveness of the performance modelling are discussed. Results from the analysis as well as the limitations of the approach are presented and discussed. (author)

Performance Characterization of Solid Oxide Cells Under High Pressure

DEFF Research Database (Denmark)

Sun, Xiufu; Bonaccorso, Alfredo Damiano; Graves, Christopher R.

2015-01-01

on partial pressures (oxygen, steam and hydrogen) were affected by increasing the pressure. In electrolysis mode at low current density, the performance improvement was counteracted by the increase in open circuit voltage, but it has to be borne in mind that the pressurized gas contains higher molar free......In this work, recent pressurized test results of a planar Ni- YSZ (YSZ: Yttria stabilized Zirconia) supported solid oxide cell are presented. Measurements were performed at 800 C in both fuel cell and electrolysis mode at different pressures. A comparison of the electrochemical performance...... of the cell at 1 and 3 bar shows a significant and equal performance gain at higher pressure in both fuel cell mode and electrolysis mode. Electrochemical impedance spectroscopy revealed that the serial resistance was not affected by the operation pressure; all the other processes that are dependent...

A preliminary study on performance of Saccharomyces cerevisiae n0 DY 7221 immobilized using grafted bioflocculant in bioethanol production

Science.gov (United States)

Suci, Windhu Griyasti; Margono, Kaavessina, Mujtahid

2018-02-01

Bioethanol has been well acknowledged to be developed as a biofuel and can be derived from renewable resources. Currently, the utilization of bioethanol as a fuel is more expensive than that of gasoline due to the high production cost. Researchers from industrial and academia have been doing some efforts to reduce it, namely: energy efficiency, exploring many potential renewable resources, increasing fermentation productivity, etc. We propose a novel immobilized Saccharomyces cerevisiae trapped in grafted bioflocculant. The flocculant was developed from polyacrylamide chains grafted into modified starches. This research aims to preliminary performance study of S. cerevisiae immobilized using our new developed method. The bioflocculant solution with the various concentration of 1%, 2%, and 2.5% v/v was dropped into 90 ml of developed inoculum to get flocs which would be used as a starter in fermentation process. The fermentation process was carried out in a shaken flask at 30oC and 150 rpm for 72 hours. The best result was obtained in the sample of 2.5% bioflocculant fraction, i.e. bioethanol 9.25% and enhanced productivity 3.6 times of free cell. These results indicate that flocculation method is a way of immobilizing yeast that needs to be further investigated.

Preliminary performance analysis of exponential experimental system for the determination of neutron effective multiplication factor of PWR spent fuel

International Nuclear Information System (INIS)

Shin, Heesung; Lee, Sang-Yun; Ro, Seung-Gy; Seo, Gi-Seok; Kim, Ho-Dong

2002-01-01

An exponential experiment system which is composed of neutron detector, signal analysis system and neutron source, 10 mCi Cf-252 has been installed in the storage pool of PIEF at KAERI in order to experimentally determining neutron effective multiplication factors of PWR spent fuel assemblies. Preliminary functional characteristic tests of the experimental system are performed for C15, J14 and J44 assemblies loaded in the pool. As a result of preliminary tests, the average neutron counts obtained for 3 minutes in the plateau of the C15, J14 and J44 assemblies are about 1900, 3800 and 3200, respectively. A dip of the neutron flux density distribution is noticed in the spacer grid position. Neutron counts at those positions appear to be reduced to about 70 % in comparison to the fuel position. The measured axial neutron distribution shapes are compared with the result for the P14 assembly and Cs-137 gamma scanning data performed in KAERI. It is revealed that the spacer grid position measured is consistent with the design specifications within a 2.3 % error. The exponential decay constants for the C15 assembly were determined to be 0.152 and 0.165 for detector and source scanning, respectively. (author)

The Preliminary Research for Implementation of Improved DTC Scheme of High Performance PMSM Drives

Directory of Open Access Journals (Sweden)

Tole Sutikno

2008-12-01

Full Text Available The direct torque control (DTC is one of control approache that is used commonly in PMSM control system. This method supports a very quick and precise torque response. However, the DTC method is not perfect and has some disadvantages. Many researchers have been proposed to modify the basic DTC scheme for PMSM drive. All this contributions allow performance to be improved, but at the same time they lead to more complex schemes. Furthermore, the PMSM drive control systems are usually based on microcontroller and DSP. Some researchers also have been used DSP and FPGA together to develop DTC for AC drives. These allow improving the performance, but they will increase cost. For the reason above, this paper proposed a new DTC scheme to apply only based on FPGA. The preliminary research showed that the proposed DTC sheme can reduce torque and flux ripples significantly. Therefore, this paper also recomend to realize proposed DTC scheme based on FPGA in order to support to execute very fast computation.The implementation is hoped that it will very potential to replace not only the induction motor but also the DC servo motor in a number of industrial process, commercial, domestic and modern military applications of high-performance drive.

Scope and purpose of the preliminary planning work

International Nuclear Information System (INIS)

Kalas, P.

1976-01-01

The results of preliminary planning work are usually expressed in a number of recommendations covering mainly: long-term national policy in the field of energy resources and selection of projects to be further studied at the feasibility level. Moreover, recommendations on further actions are made including: inventory of generation and transmission facilities recommended for the implementation in order to meet the load forecasted for medium-term period, preparation of a preliminary calender of decisions to be taken for the implementation of the projects recommended, preparation of a preliminary construction schedule, preparation of a preliminary investment program, preparation of a program of necessary engineering works, and performance of study on electricity rates which would adjust existing tariffs to proposed development program of the utility. (HP) [de

The performance of silicon solar cells operated in liquids

International Nuclear Information System (INIS)

Wang Yiping; Fang Zhenlei; Zhu Li; Huang Qunwu; Zhang Yan; Zhang Zhiying

2009-01-01

Better performance can be achieved when the bare silicon solar cells are immersed into liquids for the enhanced heat removing. In this study, the performance of solar cells immersed in liquids was examined under simulated sunlight. To distinguish the effects of the liquid optic and electric properties on the solar cells, a comparison between immersion of the solar module and the bare solar cells was carried out. It was found that the optic properties of the liquids can cause minor efficiency changes on the solar cells, while the electric properties of the liquids, the molecular polarizable and ions, are responsible for the most of the changes. The bare solar cells immersed in the non-polar silicon oil have the best performance. The accelerated life tests were carried out at 150 deg. C high temperature and under 200 W/m 2 ultraviolet light irradiation, respectively. It was found that the silicon oil has good stability. This study can give support on the cooling of the concentrated photovoltaic systems by immersing the solar cells in the liquids directly

Method to improve reliability of a fuel cell system using low performance cell detection at low power operation

Science.gov (United States)

Choi, Tayoung; Ganapathy, Sriram; Jung, Jaehak; Savage, David R.; Lakshmanan, Balasubramanian; Vecasey, Pamela M.

2013-04-16

A system and method for detecting a low performing cell in a fuel cell stack using measured cell voltages. The method includes determining that the fuel cell stack is running, the stack coolant temperature is above a certain temperature and the stack current density is within a relatively low power range. The method further includes calculating the average cell voltage, and determining whether the difference between the average cell voltage and the minimum cell voltage is greater than a predetermined threshold. If the difference between the average cell voltage and the minimum cell voltage is greater than the predetermined threshold and the minimum cell voltage is less than another predetermined threshold, then the method increments a low performing cell timer. A ratio of the low performing cell timer and a system run timer is calculated to identify a low performing cell.

Purification, crystallization and preliminary X-ray analysis of the IgV domain of human nectin-4.

Science.gov (United States)

Xu, Xiang; Zhang, Xiaoai; Lu, Guangwen; Cai, Yongping

2012-08-01

Nectin-4 belongs to a family of immunoglobulin-like cell adhesion molecules and is highly expressed in cancer cells. Recently, nectin-4 was found to be a receptor of measles virus and the IgV domain sustains strong binding to measles virus H protein. In this study, the successful expression and purification of human nectin-4 V domain (nectin-4v) is reported. The purified protein was crystallized using the sitting-drop vapour-diffusion method. The crystals diffracted to 1.8 Å resolution and belonged to space group P2(1), with unit-cell parameters a = 33.1, b = 51.7, c = 56.9 Å, β = 94.7°. Preliminary analysis of the diffraction data was also performed.

Preliminary Analysis of Remote Monitoring and Robotic Concepts for Performance Confirmation

International Nuclear Information System (INIS)

McAffee, D.A.

1997-01-01

main Performance Confirmation monitoring needs and requirements during the post-emplacement preclosure period. This includes radiological, non-radiological, host rock, and infrastructure performance monitoring needs. It also includes monitoring for possible off-normal events. (Presented in Section 7.3). (3) Identify general approaches and methods for obtaining performance information from within the emplacement drifts for Performance Confirmation. (Presented in Section 7.4) (4)Review and discuss available technologies and design strategies that may permit the use of remotely operated systems within the hostile thermal and radiation environment expected within the emplacement drifts. (Presented in Section 7.5). (5) Based on Performance Confirmation monitoring needs and available technologies, identify potential application areas for remote systems and robotics for post-emplacement preclosure Performance Confirmation activities (Presented in Section 7.6). (6) Develop preliminary remote monitoring and robotic concepts for post-emplacement, preclosure Performance Confirmation activities. (Presented in Section 7.7) This analysis is being performed very early in the systems engineering cycle, even as issues related to the Performance Confirmation program planning phase are being formulated and while the associated needs, constraints and objectives are yet to be fully determined and defined. This analysis is part of an issue formulation effort and is primarily concerned with identification and description of key issues related to remotely monitoring repository performance for Performance Confirmation. One of the purposes of this analysis is to provide an early investigation of potential design challenges that may have a high impact on future design concepts. This analysis can be used to guide future concept development and help access what is feasible and achievable by application of remote systems technology. Future design and systems engineering analysis with applicable

A preliminary parametric performance assessment for the disposal of alpha-contaminated mixed low-level waste stored at the Idaho National Engineering Laboratory

International Nuclear Information System (INIS)

Smith, T.H.; Anderson, G.L.; Myers, J.

1995-01-01

A preliminary parametric performance assessment (PA) has been performed of potential waste disposal systems for alpha-contaminated mixed low-level waste (ALLW) currently stored at the Idaho National Engineering Laboratory. The radionuclide-confinement performance of treated ALLW in various final waste forms, in various disposal locations, and under various assumptions was evaluated. Compliance with performance objectives was assessed for the undisturbed waste scenario and for intrusion scenarios. Some combinations of final waste form, disposal site, and environmental transport assumptions lead to calculated does that comply with the performance objectives, while others do not. The results will help determine the optimum degree of ALLW immobilization to satisfy the performance objectives while minimizing cost

Examining implementation and preliminary performance indicators of veterans treatment courts: The Kentucky experience.

Science.gov (United States)

Shannon, Lisa M; Birdwhistell, Shira; Hulbig, Shelia K; Jones, Afton Jackson; Newell, Jennifer; Payne, Connie

2017-08-01

Veterans' Treatment Courts (VTCs) are posited as a solution to offer rehabilitation for veterans involved in the criminal justice system. Despite the pervasive implementation of VTCs, there is little research focused specifically on VTC implementation and outcomes, which are based on other problem-solving court models such as drug court. The current study presents qualitative process evaluation data from key stakeholders (n=21) and veteran participants (n=4) to show accomplishments, challenges, and lessons learned during first-year implementation at two VTC sites. Quantitative performance data is also presented on veteran participants (n=19) served during the first year to show: types of services, monitoring, judicial interaction, sanctions/therapeutic responses, and rewards, as well as preliminary data on recidivism. Qualitative data, from both key stakeholders and veteran participants, suggests that offering rehabilitation via various program components, services/referrals, and accountability are critical to the success of the VTC. Data also provides valuable lessons learned for VTC implementation including communication, collaboration, information/protocols, and resources. Performance data shows that a variety of services are utilized and that frequent judicial interaction, drug testing, and sanctions are cornerstones of the VTC. Implications and future directions for research are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

What Happens Inside a Fuel Cell? Developing an Experimental Functional Map of Fuel Cell Performance

KAUST Repository

Brett, Daniel J. L.; Kucernak, Anthony R.; Aguiar, Patricia; Atkins, Stephen C.; Brandon, Nigel P.; Clague, Ralph; Cohen, Lesley F.; Hinds, Gareth; Kalyvas, Christos; Offer, Gregory J.; Ladewig, Bradley; Maher, Robert; Marquis, Andrew; Shearing, Paul; Vasileiadis, Nikos; Vesovic, Velisa

2010-01-01

Fuel cell performance is determined by the complex interplay of mass transport, energy transfer and electrochemical processes. The convolution of these processes leads to spatial heterogeneity in the way that fuel cells perform, particularly due

Gas-phase optical fiber photocatalytic reactors for indoor air application: a preliminary study on performance indicators

Science.gov (United States)

Palmiste, Ü.; Voll, H.

2017-10-01

The development of advanced air cleaning technologies aims to reduce building energy consumption by reduction of outdoor air flow rates while keeping the indoor air quality at an acceptable level by air cleaning. Photocatalytic oxidation is an emerging technology for gas-phase air cleaning that can be applied in a standalone unit or a subsystem of a building mechanical ventilation system. Quantitative information on photocatalytic reactor performance is required to evaluate the technical and economic viability of the advanced air cleaning by PCO technology as an energy conservation measure in a building air conditioning system. Photocatalytic reactors applying optical fibers as light guide or photocatalyst coating support have been reported as an approach to address the current light utilization problems and thus, improve the overall efficiency. The aim of the paper is to present a preliminary evaluation on continuous flow optical fiber photocatalytic reactors based on performance indicators commonly applied for air cleaners. Based on experimental data, monolith-type optical fiber reactor performance surpasses annular-type optical fiber reactors in single-pass removal efficiency, clean air delivery rate and operating cost efficiency.

Multiphase lattice Boltzmann on the Cell Broadband Engine

International Nuclear Information System (INIS)

Belletti, F.; Mantovani, F.; Tripiccione, R.; Biferale, L.; Schifano, S.F.; Toschi, F.

2009-01-01

Computational experiments are one of the most used and flexible investigation tools in fluid dynamics. The Lattice Boltzmann Equation is a well established computational method particularly promising for multi-phase flows at micro and macro scales. Here we present preliminary results on performances of the Lbe method on the Cell Broadband Engine platform.

Crystallization and preliminary X-ray diffraction analysis of West Nile virus

International Nuclear Information System (INIS)

Kaufmann, Bärbel; Plevka, Pavel; Kuhn, Richard J.; Rossmann, Michael G.

2010-01-01

Crystals of infectious West Nile virus were obtained and diffracted at best to about 25 Å resolution. Preliminary analysis of the diffraction pattern suggested tight hexagonal packing of the intact virus. West Nile virus, a human pathogen, is closely related to other medically important flaviviruses of global impact such as dengue virus. The infectious virus was purified from cell culture using polyethylene glycol (PEG) precipitation and density-gradient centrifugation. Thin amorphously shaped crystals of the lipid-enveloped virus were grown in quartz capillaries equilibrated by vapor diffusion. Crystal diffraction extended at best to a resolution of about 25 Å using synchrotron radiation. A preliminary analysis of the diffraction images indicated that the crystals had unit-cell parameters a ≃ b ≃ 480 Å, γ = 120°, suggesting a tight hexagonal packing of one virus particle per unit cell

Emergency CT brain: preliminary interpretation with a tablet device: image quality and diagnostic performance of the Apple iPad.

LENUS (Irish Health Repository)

Mc Laughlin, Patrick

2012-04-01

Tablet devices have recently been used in radiological image interpretation because they have a display resolution comparable to desktop LCD monitors. We identified a need to examine tablet display performance prior to their use in preliminary interpretation of radiological images. We compared the spatial and contrast resolution of a commercially available tablet display with a diagnostic grade 2 megapixel monochrome LCD using a contrast detail phantom. We also recorded reporting discrepancies, using the ACR RADPEER system, between preliminary interpretation of 100 emergency CT brain examinations on the tablet display and formal review on a diagnostic LCD. The iPad display performed inferiorly to the diagnostic monochrome display without the ability to zoom. When the software zoom function was enabled on the tablet device, comparable contrast detail phantom scores of 163 vs 165 points were achieved. No reporting discrepancies were encountered during the interpretation of 43 normal examinations and five cases of acute intracranial hemorrhage. There were seven RADPEER2 (understandable) misses when using the iPad display and 12 with the diagnostic LCD. Use of software zoom in the tablet device improved its contrast detail phantom score. The tablet allowed satisfactory identification of acute CT brain findings, but additional research will be required to examine the cause of "understandable" reporting discrepancies that occur when using tablet devices.

Preliminary performance assessment for the Waste Isolation Pilot Plant, December 1992

International Nuclear Information System (INIS)

1993-08-01

Before disposing of transuranic radioactive waste in the Waste Isolation Pilot Plant (WIPP), the United States Department of Energy (DOE) must evaluate compliance with applicable long-term regulations of the United States Environmental Protection Agency (EPA). Sandia National Laboratories is conducting iterative performance assessments (PAs) of the WIPP for the DOE to provide interim guidance while preparing for a final compliance evaluation. This volume of the 1992 PA contains results of uncertainty and sensitivity analyses with respect to migration of gas and brine from the undisturbed repository. Additional information about the 1992 PA is provided in other volumes. Volume 1 contains an overview of WIPP PA and results of a preliminary comparison with 40 CFR 191, Subpart B. Volume 2 describes the technical basis for the performance assessment, including descriptions of the linked computational models used in the Monte Carlo analyses. Volume 3 contains the reference data base and values for input parameters used in consequence and probability modeling. Volume 4 contains uncertainty and sensitivity analyses with respect to the EPA's Environmental Standards for the Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes (40 CFR 191, Subpart B). Finally, guidance derived from the entire 1992 PA is presented in Volume 6. Results of the 1992 uncertainty and sensitivity analyses indicate that, conditional on the modeling assumptions and the assigned parameter-value distributions, the most important parameters for which uncertainty has the potential to affect gas and brine migration from the undisturbed repository are: initial liquid saturation in the waste, anhydrite permeability, biodegradation-reaction stoichiometry, gas-generation rates for both corrosion and biodegradation under inundated conditions, and the permeability of the long-term shaft seal

Performance Gains of Propellant Management Devices for Liquid Hydrogen Depots

Science.gov (United States)

Hartwig, Jason W.; McQuillen, John B.; Chato, David J.

2013-01-01

This paper presents background, experimental design, and preliminary experimental results for the liquid hydrogen bubble point tests conducted at the Cryogenic Components Cell 7 facility at the NASA Glenn Research Center in Cleveland, Ohio. The purpose of the test series was to investigate the parameters that affect liquid acquisition device (LAD) performance in a liquid hydrogen (LH2) propellant tank, to mitigate risk in the final design of the LAD for the Cryogenic Propellant Storage and Transfer Technology Demonstration Mission, and to provide insight into optimal LAD operation for future LH2 depots. Preliminary test results show an increase in performance and screen retention over the low reference LH2 bubble point value for a 325 2300 screen in three separate ways, thus improving fundamental LH2 LAD performance. By using a finer mesh screen, operating at a colder liquid temperature, and pressurizing with a noncondensible pressurant gas, a significant increase in margin is achieved in bubble point pressure for LH2 screen channel LADs.

Preliminary Study of the Use of Sulphonated Polyether Ether Ketone (SPEEK as Proton Exchange Membrane for Microbial Fuel Cell (MFC

Directory of Open Access Journals (Sweden)

Dani Permana

2018-02-01

Full Text Available Sulfonated polyether ether ketone (SPEEK was utilized as a proton exchange membrane (PEM in Microbial Fuel Cell (MFC. The SPEEK performance in producing electricity had been observed in MFC using wastewater and glucose as substrates. The MFC with catering and tofu wastewater produced maximum power density about 0.31 mW/m2 and 0.03 mW/m2, respectively, lower that of MFC with tapioca average power density of 39.4 W/m2 over 48 h. The power density boosted because of the presence of Saccharomyces cerevisiae as inoculum. The study using of S. cerevisiae and Acetobacter acetii, separately, were also conducted in with glucose as substrate. The MFC produced an average power densities were 7.3 and 6.4 mW/m2 for S. cerevisiae and A. acetii, respectively. The results of this study indicated that SPEEK membrane has the potential usage in MFCs and can substitute the commercial membrane, Nafion. Article History: Received: Juni 14th 2017; Received: Sept 25th 2017; Accepted: December 16th 2017; Available online How to Cite This Article: Putra, H.E., Permana, D and Djaenudin, D. (2018 Preliminary Study of the Use of Sulfonated Polyether Ether Ketone (SPEEK as Proton Exchange Membrane for Microbial Fuel Cell (MFC. International Journal of Renewable Energy Development, 7(1, 7-12. https://doi.org/10.14710/ijred.7.1.7-12

Performance enhancement of PV cells through micro-channel cooling

Directory of Open Access Journals (Sweden)

Muzaffar Ali

2015-11-01

Full Text Available Efficiency of a PV cell is strongly dependent on its surface temperature. The current study is focused to achieve maximum efficiency of PV cells even in scorching temperatures in hot climates like Pakistan where the cell surface temperatures can even rise up to around 80 ℃. The study includes both the CFD and real time experimental investigations of a solar panel using micro channel cooling. Initially, CFD analysis is performed by developing a 3D model of a Mono-Crystalline cell with micro-channels to analyze cell surface temperature distribution at different irradiance and water flow rates. Afterwards, an experimental setup is developed for performance investigations under the real conditions of an open climate of a Pakistan's city, Taxila. Two 35W panels are manufactured for the experiments; one is based on the standard manufacturing procedure while other cell is developed with 4mm thick aluminum sheet having micro-channels of cross-section of 1mm by 1mm. The whole setup also includes different sensors for the measurement of solar irradiance, cell power, surface temperature and water flow rates. The experimental results show that PV cell surface temperature drop of around 15 ℃ is achieved with power increment of around 14% at maximum applied water flow rate of 3 LPM. Additionally, a good agreement is also found between CFD and experimental results. Therefore, that study clearly shows that a significant performance improvement of PV cells can be achieved through the proposed cell cooling technique.

Monitoring the Microgravity Environment Quality On-board the International Space Station Using Soft Computing Techniques. Part 2; Preliminary System Performance Results

Science.gov (United States)

Jules, Kenol; Lin, Paul P.; Weiss, Daniel S.

2002-01-01

This paper presents the preliminary performance results of the artificial intelligence monitoring system in full operational mode using near real time acceleration data downlinked from the International Space Station. Preliminary microgravity environment characterization analysis result for the International Space Station (Increment-2), using the monitoring system is presented. Also, comparison between the system predicted performance based on ground test data for the US laboratory "Destiny" module and actual on-orbit performance, using measured acceleration data from the U.S. laboratory module of the International Space Station is presented. Finally, preliminary on-orbit disturbance magnitude levels are presented for the Experiment of Physics of Colloids in Space, which are compared with on ground test data. The ground test data for the Experiment of Physics of Colloids in Space were acquired from the Microgravity Emission Laboratory, located at the NASA Glenn Research Center, Cleveland, Ohio. The artificial intelligence was developed by the NASA Glenn Principal Investigator Microgravity Services Project to help the principal investigator teams identify the primary vibratory disturbance sources that are active, at any moment of time, on-board the International Space Station, which might impact the microgravity environment their experiments are exposed to. From the Principal Investigator Microgravity Services' web site, the principal investigator teams can monitor via a dynamic graphical display, implemented in Java, in near real time, which event(s) is/are on, such as crew activities, pumps, fans, centrifuges, compressor, crew exercise, structural modes, etc., and decide whether or not to run their experiments, whenever that is an option, based on the acceleration magnitude and frequency sensitivity associated with that experiment. This monitoring system detects primarily the vibratory disturbance sources. The system has built-in capability to detect both known

Performance of PEM Liquid-Feed Direct Methanol-Air Fuel Cells

Science.gov (United States)

Narayanan, S. R.

1995-01-01

A direct methanol-air fuel cell operating at near atmospheric pressure, low-flow rate air, and at temperatures close to 60oC would tremendously enlarge the scope of potential applications. While earlier studies have reported performance with oxygen, the present study focuses on characterizing the performance of a PEM liquid feed direct methanol-air cell consisting of components developed in house. These cells employ Pt-Ru catalyst in the anode, Pt at the cathode and Nafion 117 as the PEM. The effect of pressure, flow rate of air and temperature on cell performance has been studied. With air, the performance level is as high as 0.437 V at 300 mA/cm2 (90oC, 20 psig, and excess air flow) has been attained. Even more significant is the performance level at 60oC, 1 atm and low flow rates of air (3-5 times stoichiometric), which is 0.4 V at 150 mA/cm2. Individual electrode potentials for the methanol and air electrode have been separated and analyzed. Fuel crossover rates and the impact of fuel crossover on the performance of the air electrode have also been measured. The study identifies issues specific to the methanol-air fuel cell and provides a basis for improvement strategies.

A preliminary study on the association between ventilation rates in classrooms and student performance.

Science.gov (United States)

Shaughnessy, R J; Haverinen-Shaughnessy, U; Nevalainen, A; Moschandreas, D

2006-12-01

Poor conditions leading to substandard indoor air quality (IAQ) in classrooms have been frequently cited in the literature over the past two decades. However, there is limited data linking poor IAQ in the classrooms to student performance. Whereas, it is assumed that poor IAQ results in reduced attendance and learning potential, and subsequent poor student performance, validating this hypothesis presents a challenge in today's school environment. This study explores the association between student performance on standardized aptitude tests that are administered to students on a yearly basis, to classroom carbon dioxide (CO2) concentrations, which provide a surrogate of ventilation being provided to each room. Data on classroom CO2 concentrations (over a 4-5 h time span within a typical school day) were recorded in fifth grade classrooms in 54 elementary schools within a school district in the USA. Results from this preliminary study yield a significant (P classroom-level ventilation rate and test results in math. They also indicate that non-linear effects may need to be considered for better representation of the association. A larger sample size is required in order to draw more definitive conclusions. Practical Implications Future studies could focus on (1) gathering more evidence on the possible association between classroom ventilation rates and students' academic performance; (2) the linear/non-linear nature of the association; and (3) whether it is possible to detect 'no observed adverse effect level' for adequate ventilation with respect to academic performance in schools. All of this information could be used to improve guidance and take regulatory actions to ensure adequate ventilation in schools. The high prevalence of low ventilation rates, combined with the growing evidence of the positive impact that sufficient ventilation has on human performance, suggests an opportunity for improving design and management of school facilities.

Preliminary Opto-Mechanical Design for the X2000 Transceiver

Science.gov (United States)

Hemmati, H.; Page, N. A.

2000-01-01

Preliminary optical design and mechanical conceptual design for a 30 cm aperture transceiver are described. A common aperture is used for both transmit and receive. Special attention was given to off-axis and scattered light rejection and isolation of the receive channel from the transmit channel. Requirements, details of the design and preliminary performance analysis of the transceiver are provided.

Expression, crystallization and preliminary crystallographic study of GluB from Corynebacterium glutamicum

International Nuclear Information System (INIS)

Liu, Qingbo; Li, Defeng; Hu, Yonglin; Wang, Da-Cheng

2013-01-01

GluB, a substrate-binding protein from C. glutamicum, was expressed, purified and crystallized, followed by X-ray diffraction data collection and preliminary crystallographic analysis. GluB is a substrate-binding protein (SBP) which participates in the uptake of glutamic acid in Corynebacterium glutamicum, a Gram-positive bacterium. It is part of an ATP-binding cassette (ABC) transporter system. Together with the transmembrane proteins GluC and GluD and the cytoplasmic protein GluA, which couples the hydrolysis of ATP to the translocation of glutamate, they form a highly active glutamate-uptake system. As part of efforts to study the amino-acid metabolism, especially the metabolism of glutamic acid by C. glutamicum, a bacterium that is widely used in the industrial production of glutamic acid, the GluB protein was expressed, purified and crystallized, an X-ray diffraction data set was collected to a resolution of 1.9 Å and preliminary crystallographic analysis was performed. The crystal belonged to space group P3 1 21 or P3 2 21, with unit-cell parameters a = b = 82.50, c = 72.69 Å

In Vivo Articular Cartilage Regeneration Using Human Dental Pulp Stem Cells Cultured in an Alginate Scaffold: A Preliminary Study

Directory of Open Access Journals (Sweden)

Manuel Mata

2017-01-01

Full Text Available Osteoarthritis is an inflammatory disease in which all joint-related elements, articular cartilage in particular, are affected. The poor regeneration capacity of this tissue together with the lack of pharmacological treatment has led to the development of regenerative medicine methodologies including microfracture and autologous chondrocyte implantation (ACI. The effectiveness of ACI has been shown in vitro and in vivo, but the use of other cell types, including bone marrow and adipose-derived mesenchymal stem cells, is necessary because of the poor proliferation rate of isolated articular chondrocytes. In this investigation, we assessed the chondrogenic ability of human dental pulp stem cells (hDPSCs to regenerate cartilage in vitro and in vivo. hDPSCs and primary isolated rabbit chondrocytes were cultured in chondrogenic culture medium and found to express collagen II and aggrecan. Both cell types were cultured in 3% alginate hydrogels and implanted in a rabbit model of cartilage damage. Three months after surgery, significant cartilage regeneration was observed, particularly in the animals implanted with hDPSCs. Although the results presented here are preliminary, they suggest that hDPSCs may be useful for regeneration of articular cartilage.

In Vivo Articular Cartilage Regeneration Using Human Dental Pulp Stem Cells Cultured in an Alginate Scaffold: A Preliminary Study.

Science.gov (United States)

Mata, Manuel; Milian, Lara; Oliver, Maria; Zurriaga, Javier; Sancho-Tello, Maria; de Llano, Jose Javier Martin; Carda, Carmen

2017-01-01

Osteoarthritis is an inflammatory disease in which all joint-related elements, articular cartilage in particular, are affected. The poor regeneration capacity of this tissue together with the lack of pharmacological treatment has led to the development of regenerative medicine methodologies including microfracture and autologous chondrocyte implantation (ACI). The effectiveness of ACI has been shown in vitro and in vivo , but the use of other cell types, including bone marrow and adipose-derived mesenchymal stem cells, is necessary because of the poor proliferation rate of isolated articular chondrocytes. In this investigation, we assessed the chondrogenic ability of human dental pulp stem cells (hDPSCs) to regenerate cartilage in vitro and in vivo . hDPSCs and primary isolated rabbit chondrocytes were cultured in chondrogenic culture medium and found to express collagen II and aggrecan. Both cell types were cultured in 3% alginate hydrogels and implanted in a rabbit model of cartilage damage. Three months after surgery, significant cartilage regeneration was observed, particularly in the animals implanted with hDPSCs. Although the results presented here are preliminary, they suggest that hDPSCs may be useful for regeneration of articular cartilage.

Study on the micro direct ethanol fuel cell (Micro-DEFC) performance

Science.gov (United States)

Saisirirat, Penyarat; Joommanee, Bordindech

2018-01-01

The direct ethanol fuel cell (DEFC) is selected for this research. DEFC uses ethanol in the fuel cell instead of the more toxic methanol. Ethanol is more attractive than methanol by many reasons. Ethanol is a hydrogen-rich liquid and it has a higher specific energy (8.0 kWh/kg) compared to that of methanol (6.1 kWh/kg). Ethanol can be obtained in great quantity from biomass through a fermentation process from renewable resources such as sugar cane, wheat, corn, and even straw. The use of ethanol would also overcome both the storage and infrastructure challenge of hydrogen for fuel cell applications. The experimental apparatus on the micro direct ethanol fuel cell for measuring the cell performance has been set for this research. The objective is to study the micro direct ethanol fuel cell performance for applying with the portable electronic devices. The cell performance is specified in the terms of cell voltage, cell current and power of the cell at room operating temperature and 1 atm for the pressure and also includes the ethanol fuel consumption. The effect of operating temperature change on the electrical production performance is also studied. The steady-state time for collecting each data value is about 5-10 minutes. The results show that with the increase of concentrations of ethanol by volume, the reactant concentration at the reaction sites increases so the electrochemical rate also increases but when it reaches the saturated point the performance gradually drops.

Preliminary Test for Constitutive Models of CAP

Energy Technology Data Exchange (ETDEWEB)

Choo, Yeon Joon; Hong, Soon Joon; Hwang, Su Hyun; Lee, Keo Hyung; Kim, Min Ki; Lee, Byung Chul [FNC Tech., Seoul (Korea, Republic of); Ha, Sang Jun; Choi, Hoon [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

2010-05-15

The development project for the domestic design code was launched to be used for the safety and performance analysis of pressurized light water reactors. As a part of this project, CAP (Containment Analysis Package) code has been developing for the containment safety and performance analysis side by side with SPACE. The CAP code treats three fields (vapor, continuous liquid and dispersed drop) for the assessment of containment specific phenomena, and is featured by assessment capabilities in multi-dimensional and lumped parameter thermal hydraulic cell. Thermal hydraulics solver was developed and has a significant progress now. Implementation of the well proven constitutive models and correlations are essential in other for a containment code to be used with the generalized or optimized purposes. Generally, constitutive equations are composed of interfacial and wall transport models and correlations. These equations are included in the source terms of the governing field equations. In order to develop the best model and correlation package of the CAP code, various models currently used in major containment analysis codes, such as GOTHIC, CONTAIN2.0 and CONTEMPT-LT are reviewed. Several models and correlations were incorporated for the preliminary test of CAP's performance and test results and future plans to improve the level of execution besides will be discussed in this paper

Preliminary Test for Constitutive Models of CAP

International Nuclear Information System (INIS)

Choo, Yeon Joon; Hong, Soon Joon; Hwang, Su Hyun; Lee, Keo Hyung; Kim, Min Ki; Lee, Byung Chul; Ha, Sang Jun; Choi, Hoon

2010-01-01

The development project for the domestic design code was launched to be used for the safety and performance analysis of pressurized light water reactors. As a part of this project, CAP (Containment Analysis Package) code has been developing for the containment safety and performance analysis side by side with SPACE. The CAP code treats three fields (vapor, continuous liquid and dispersed drop) for the assessment of containment specific phenomena, and is featured by assessment capabilities in multi-dimensional and lumped parameter thermal hydraulic cell. Thermal hydraulics solver was developed and has a significant progress now. Implementation of the well proven constitutive models and correlations are essential in other for a containment code to be used with the generalized or optimized purposes. Generally, constitutive equations are composed of interfacial and wall transport models and correlations. These equations are included in the source terms of the governing field equations. In order to develop the best model and correlation package of the CAP code, various models currently used in major containment analysis codes, such as GOTHIC, CONTAIN2.0 and CONTEMPT-LT are reviewed. Several models and correlations were incorporated for the preliminary test of CAP's performance and test results and future plans to improve the level of execution besides will be discussed in this paper

Preliminary Demonstration of Power Beaming With Non-Coherent Laser Diode Arrays

National Research Council Canada - National Science Library

Kare, Jordin

1999-01-01

A preliminary demonstration of free-space electric power transmission has been conducted using non-coherent laser diode arrays as the transmitter and standard silicon photovoltaic cell arrays as the receiver...

Performance of direct alcohol fuel cells fed with mixed methanol/ethanol solutions

Energy Technology Data Exchange (ETDEWEB)

Wongyao, N. [The Joint Graduate School of Energy and Environment, King Mongkut' s University of Technology Thonburi, 126 Pracha-Uthit Rd., Bang Mod, Thung Khru, Bangkok 10140 (Thailand); Therdthianwong, A., E-mail: apichai.the@kmutt.ac.t [Fuel Cell and Hydrogen Research and Engineering Center, Clean Energy System Group, PDTI, King Mongkut' s University of Technology Thonburi, 126 Pracha-Uthit Rd., Bang Mod, Thung Khru, Bangkok 10140 (Thailand); Therdthianwong, S. [Department of Chemical Engineering, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, 126 Pracha-Uthit Rd., Bang Mod, Thung Khru, Bangkok 10140 (Thailand)

2011-07-15

Research highlights: {yields} We examined the performance of direct alcohol fuel cells fed with mixed alcohol. {yields} PtRu-PtSn/C and PtRu/C as catalysts for mixed alcohol electrooxidation reaction. {yields} Misplace adsorption of ethanol on PtRu/C caused the cell performance drop. {yields} PtRu/C showed higher performance than PtRu-PtSn/C for mixed alcohol fuel. -- Abstract: In combining the advantages of both methanol and ethanol, direct alcohol fuel cells fed with mixed alcohol solutions (1 M methanol and 1 M ethanol in varying volume ratios) were tested for performance. Employing a PtRu-PtSn/C catalyst as anode, cell performance was found to diminish rapidly even at 2.5% by volume ethanol mixture. Further increase of ethanol exceeded 10%, the cell performance gradually decreased and finally approached that of direct ethanol fuel cells. The causes of the decrease in the cell performance were the slow electro-oxidation of ethanol and the misplaced adsorption of ethanol on PtRu/C. By comparing the PtRu-PtSn/C cell with the PtRu/C cell operated with mixed alcohol solutions, the cell using PtRu/C as an anode catalyst provided higher power density since more PtRu/C surface was available for methanol oxidation reaction and less ohmic resistance of PtRu/C than that of PtRu-PtSn/C. In order to reach optimization of DAFC performance fed with mixed alcohol, the electrocatalyst used for the anode must selectively adsorb an alcohol, especially ethanol.

Performance of direct alcohol fuel cells fed with mixed methanol/ethanol solutions

International Nuclear Information System (INIS)

Wongyao, N.; Therdthianwong, A.; Therdthianwong, S.

2011-01-01

Research highlights: → We examined the performance of direct alcohol fuel cells fed with mixed alcohol. → PtRu-PtSn/C and PtRu/C as catalysts for mixed alcohol electrooxidation reaction. → Misplace adsorption of ethanol on PtRu/C caused the cell performance drop. → PtRu/C showed higher performance than PtRu-PtSn/C for mixed alcohol fuel. -- Abstract: In combining the advantages of both methanol and ethanol, direct alcohol fuel cells fed with mixed alcohol solutions (1 M methanol and 1 M ethanol in varying volume ratios) were tested for performance. Employing a PtRu-PtSn/C catalyst as anode, cell performance was found to diminish rapidly even at 2.5% by volume ethanol mixture. Further increase of ethanol exceeded 10%, the cell performance gradually decreased and finally approached that of direct ethanol fuel cells. The causes of the decrease in the cell performance were the slow electro-oxidation of ethanol and the misplaced adsorption of ethanol on PtRu/C. By comparing the PtRu-PtSn/C cell with the PtRu/C cell operated with mixed alcohol solutions, the cell using PtRu/C as an anode catalyst provided higher power density since more PtRu/C surface was available for methanol oxidation reaction and less ohmic resistance of PtRu/C than that of PtRu-PtSn/C. In order to reach optimization of DAFC performance fed with mixed alcohol, the electrocatalyst used for the anode must selectively adsorb an alcohol, especially ethanol.

Cell shunt resistance and photovoltaic module performance

Energy Technology Data Exchange (ETDEWEB)

McMahon, T.J.; Basso, T.S.; Rummel, S.R. [National Renewable Energy Lab., Golden, CO (United States)

1996-05-01

Shunt resistance of cells in photovoltaic modules can affect module power output and could indicate flawed manufacturing processes and reliability problems. The authors describe a two-terminal diagnostic method to directly measure the shunt resistance of individual cells in a series-connected module non-intrusively, without deencapsulation. Peak power efficiency vs. light intensity was measured on a 12-cell, series-connected, single crystalline module having relatively high cell shunt resistances. The module was remeasured with 0.5-, 1-, and 2-ohm resistors attached across each cell to simulate shunt resistances of several emerging technologies. Peak power efficiencies decreased dramatically at lower light levels. Using the PSpice circuit simulator, the authors verified that cell shunt and series resistances can indeed be responsible for the observed peak power efficiency vs. intensity behavior. The authors discuss the effect of basic cell diode parameters, i.e., shunt resistance, series resistance, and recombination losses, on PV module performance as a function of light intensity.

Performance of PEM fuel cells stack as affected by number of cell and gas flow-rate

Science.gov (United States)

Syampurwadi, A.; Onggo, H.; Indriyati; Yudianti, R.

2017-03-01

The proton exchange membrane fuel cell (PEMFC) is a promising technology as an alternative green energy due to its high power density, low operating temperatures, low local emissions, quiet operation and fast start up-shutdown. In order to apply fuel cell as portable power supply, the performance investigation of small number of cells is needed. In this study, PEMFC stacks consisting of 1, 3, 5 and 7-cells with an active area of 25 cm2 per cell have been designed and developed. Their was evaluated in variation of gas flow rate. The membrane electrode assembly (MEA) was prepared by hot-pressing commercial gas diffusion electrodes (Pt loading 0.5 mg/cm2) on pre-treated Nafion 117 membrane. The stacks were constructed using bipolar plates in serpentine pattern and Z-type gas flow configuration. The experimental results were presented as polarization and power output curves which show the effects of varying number of cells and H2/O2 flow-rates on the PEMFC performance. The experimental results showed that not only number of cells and gas flow-rates affected the fuel cells performance, but also the operating temperature as a result of electrochemistry reaction inside the cell.

Use of an adaptable cell culture kit for performing lymphocyte and monocyte cell cultures in microgravity

Science.gov (United States)

Hatton, J. P.; Lewis, M. L.; Roquefeuil, S. B.; Chaput, D.; Cazenave, J. P.; Schmitt, D. A.

1998-01-01

The results of experiments performed in recent years on board facilities such as the Space Shuttle/Spacelab have demonstrated that many cell systems, ranging from simple bacteria to mammalian cells, are sensitive to the microgravity environment, suggesting gravity affects fundamental cellular processes. However, performing well-controlled experiments aboard spacecraft offers unique challenges to the cell biologist. Although systems such as the European 'Biorack' provide generic experiment facilities including an incubator, on-board 1-g reference centrifuge, and contained area for manipulations, the experimenter must still establish a system for performing cell culture experiments that is compatible with the constraints of spaceflight. Two different cell culture kits developed by the French Space Agency, CNES, were recently used to perform a series of experiments during four flights of the 'Biorack' facility aboard the Space Shuttle. The first unit, Generic Cell Activation Kit 1 (GCAK-1), contains six separate culture units per cassette, each consisting of a culture chamber, activator chamber, filtration system (permitting separation of cells from supernatant in-flight), injection port, and supernatant collection chamber. The second unit (GCAK-2) also contains six separate culture units, including a culture, activator, and fixation chambers. Both hardware units permit relatively complex cell culture manipulations without extensive use of spacecraft resources (crew time, volume, mass, power), or the need for excessive safety measures. Possible operations include stimulation of cultures with activators, separation of cells from supernatant, fixation/lysis, manipulation of radiolabelled reagents, and medium exchange. Investigations performed aboard the Space Shuttle in six different experiments used Jurkat, purified T-cells or U937 cells, the results of which are reported separately. We report here the behaviour of Jurkat and U937 cells in the GCAK hardware in ground

Preliminary performance assessment for the Waste Isolation Pilot Plant, December 1992. Volume 1, Third comparison with 40 CFR 191, Subpart B

Energy Technology Data Exchange (ETDEWEB)

1992-12-01

Before disposing of transuranic radioactive wastes in the Waste Isolation Pilot Plant (WIPP), the United States Department of Energy (DOE) must evaluate compliance with applicable long-term regulations of the United States Environmental Protection Agency (EPA). Sandia National Laboratories is conducting iterative performance assessments of the WIPP for the DOE to provide interim guidance while preparing for final compliance evaluations. This volume contains an overview of WIPP performance assessment and a preliminary comparison with the long-term requirements of the Environmental Radiation Protection Standards for Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes (40 CFR 191, Subpart B).

R and D Requirements, RF Gun Mode Studies, FEL-2 Steady-State Studies, Preliminary FEL-1 Time-Dependent Studies, and Preliminary Layout Option Investigation

International Nuclear Information System (INIS)

Byrd, John; Corlett, John; Doolittle, Larry; Fawley, William; Lidia, Steven; Penn, Gregory; Ratti, Alex; Staples, John; Wilcox Russell; Wurtele, Jonathan; Zholents, Alexander

2005-01-01

This report constitutes the third deliverable of LBNLs contracted role in the FERMI (at) Elettra Technical Optimization study. It describes proposed RandD activities for the baseline design of the Technical Optimization Study, initial studies of the RF gun mode-coupling and potential effects on beam dynamics, steady-state studies of FEL-2 performance to 10 nm, preliminary studies of time-dependent FEL-1 performance using electron bunch distribution from the start-to-end studies, and a preliminary investigation of a configuration with FEL sinclined at a small angle from the line of the linac

Preliminary Cluster Size and Efficiencies results of CMS RPC at GIF++

CERN Document Server

Gonzalez Blanco Gonzalez, Genoveva

2016-01-01

A brief description and first preliminary results of the Efficiencies and Cluster Size measurements of the CMS Resistive Plate Chambers, will be presented inside the Gamma Irradiation Facility GIF++ at CERN. Preliminary studies that sets the base performance measurements of CMS RPC for starting aging studies.

Preliminary parametric performance assessment of potential final waste forms for alpha low-level waste at the Idaho National Engineering Laboratory. Revision 1

International Nuclear Information System (INIS)

Smith, T.H.; Sussman, M.E.; Myers, J.; Djordjevic, S.M.; DeBiase, T.A.; Goodrich, M.T.; DeWitt, D.

1995-08-01

This report presents a preliminary parametric performance assessment (PA) of potential waste disposal systems for alpha-contaminated, mixed, low-level waste (ALLW) currently stored at the Transuranic Storage Area of INEL. The ALLW, which contains from 10 to 100 nCi/g of transuranic (TRU) radionuclides, is awaiting treatment and disposal. The purpose of this study was to examine the effects of several parameters on the radiological-confinement performance of potential disposal systems for the ALLW. The principal emphasis was on the performance of final waste forms (FWFs). Three categories of FWF (cement, glass, and ceramic) were addressed by evaluating the performance of two limiting FWFs for each category. Performance at five conceptual disposal sites was evaluated to illustrate the effects of site characteristics on the performance of the total disposal system. Other parameters investigated for effects on receptor dose included inventory assumptions, TRU radionuclide concentration, FWF fracture, disposal depth, water infiltration rates, subsurface-transport modeling assumptions, receptor well location, intrusion scenario assumptions, and the absence of waste immobilization. These and other factors were varied singly and in some combinations. The results indicate that compliance of the treated and disposed ALLW with the performance objectives depends on the assumptions made, as well as on the FWF and the disposal site. Some combinations result in compliance, while others do not. The implications of these results for decision making relative to treatment and disposal of the INEL ALLW are discussed. The report compares the degree of conservatism in this preliminary parametric PA against that in four other PAs and one risk assessment. All of the assessments addressed the same disposal site, but different wastes. The report also presents a qualitative evaluation of the uncertainties in the PA and makes recommendations for further study

Preliminary effects of pagoclone, a partial GABAA agonist, on neuropsychological performance

Directory of Open Access Journals (Sweden)

Angela F Caveney

2008-03-01

Full Text Available Angela F Caveney1, Bruno Giordani1, George M Haig21Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA; 2Neurosciences Development, Abbott Laboratories, Abbott Park, IL, USAAbstract: Pagoclone is a novel cyclopyrrolone that acts as a partial GABAA receptor agonist. Preclinical studies suggest that pagoclone may have clinical utility as an anxiolytic agent, as well as a reduced incidence of side-effects. The present study was conducted to determine whether pagoclone would affect healthy individuals’ performances on neuropsychological measures as a function of dose within the projected therapeutic range. Twelve healthy adult subjects were randomly assigned to dosage groups in a 3-way crossover study. Participants were administered neuropsychological measures six hours following dosing on Day 1 and Day 6 of administration of the drug. Dose effects were noted on measures of alertness, learning, and memory and movement time. Significant effects were also noted on measures of alertness, learning and memory, information processing and psychomotor speed. Overall, the results of this small, preliminary study do not support a finding of behavioral toxicity for these doses of pagoclone. Rather, a pattern was found of transient and mild negative effects on learning and memory scores at the highest dose administered, though these changes were small and no longer evident by the sixth day of use.Keywords: pagoclone, cyclopyrrolone, neuropsychological, memory, generalized anxiety disorder

Preliminary Performance Analysis Program Development for Safety System with Safeguard Vessel

International Nuclear Information System (INIS)

Kang, Han-Ok; Lee, Jun; Park, Cheon-Tae; Yoon, Ju-Hyeon; Park, Keun-Bae

2007-01-01

SMART is an advanced modular integral type pressurized water reactor for a seawater desalination and an electricity production. Major components of the reactor coolant system such as the pressurizer, Reactor Coolant Pump (RCP), and steam generators are located inside the reactor vessel. The SMART can fundamentally eliminate the possibility of large break loss of coolant accidents (LBLOCAs), improve the natural circulation capability, and better accommodate and thus enhance a resistance to a wide range of transients and accidents. The safety goals of the SMART are enhanced through highly reliable safety systems such as the passive residual heat removal system (PRHRS) and the safeguard vessel coupled with the passive safety injection feature. The safeguard vessel is a steel-made, leak-tight pressure vessel housing the RPV, SIT, and the associated valves and pipelines. A primary function of the safeguard vessel is to confine any radioactive release from the primary circuit within the vessel under DBAs related to loss of the integrity of the primary system. A preliminary performance analysis program for a safety system using the safeguard vessel is developed in this study. The developed program is composed of several subroutines for the reactor coolant system, passive safety injection system, safeguard vessel including the pressure suppression pool, and PRHRS. A small break loss of coolant accident at the upper part of a reactor is analyzed and the results are discussed

Repetitious nature of repaired DNA in mammalian cells

International Nuclear Information System (INIS)

1978-01-01

The report consists of three appendices, as follows: summary of preliminary studies of the comparative DNA repair in normal lymphoblastoid and Burkitt's lymphoma cell lines; nonuniform reassociation of human lymphoblastoid cell DNA repair replicated following methyl methane sulfonate treatment; and preliminary DNA single-strand breakage studies in the L5178Y cell line

STUDY OF PERFORMANCES OF ORGANIC SOLAR CELLS BY ...

African Journals Online (AJOL)

30 juin 2011 ... results of analysis of performances of organic solar cells by using what one call the datamining materials. ... Keywords: organic solar cells, gap energie, effiency, PCA. Author Correspondence .... oubli est malencontreux car le type de données disponibles influence toujours la direction de la recherche.

Impact of Interfacial Water Transport in PEMFCs on Cell Performance

International Nuclear Information System (INIS)

Kotaka, Toshikazu; Tabuchi, Yuichiro; Pasaogullari, Ugur; Wang, Chao-Yang

2014-01-01

Coupled cell performance evaluation, liquid water visualization by neutron radiography (NRG) and numerical modeling based on multiphase mixture (M2) model were performed with three types of GDMs: Micro Porous Layer (MPL) free; Carbon Paper (CP) with MPL; and CP free to investigate interfacial liquid water transport phenomena in PEMFCs and its effect on cell performance. The visualized results of MPL free GDM with different wettability of bi-polar plates (BPPs) showed hydrophilic BPP improved liquid water transport at the interface between CP and channel. Numerical modeling results indicated that this difference with BPP wettability was caused by the liquid water coverage difference on CP surface. Thus, controlling liquid water coverage is the one of the key strategies for improving cell performance. Additionally, liquid water distributions across the cell for three types of GDMs were compared and significant difference in liquid water content at the interface between Catalyst Layer (CL) and GDM was observed. Numerical modeling suggests this difference is influenced by the gap at the interface and that the MPL could minimize this effect. The CP free cell (i.e. only MPL) showed the best performance and the lowest liquid water content. There were multiple impacts of interfacial liquid water transport both at CL-GDM and GDM-channel interfaces. High hydrophobicity and fine structure of MPLs contributed to enhanced liquid water transport at GDM-channel interface and as a result reduced the liquid water coverage. At the same time, MPL improves contact at the CL-GDM interface in the same manner as seen in CP with MPL case. Thus, the CP free concept showed the best performance. It is suggested that the design of the interface between each component of the PEMFC has a great impact on cell performance and plays a significant role in achievement of high current density operation and cost reduction in FCEVs

Preliminary I&C Design for LORELEI

International Nuclear Information System (INIS)

Korotkin, S.; Kaufman, Y.; Guttmann, E. B.; Levy, S.; Amidan, D.; Gdalyho, B.; Cahana, T.; Ellenbogen, A.; Arad, M.; Weiss, Y.; Sasson, A.; Ferry, L.; Bourrelly, F.; Cohen, Y.

2014-01-01

This document summarizes the preliminary I&C design for LORELEI experiment The preliminary design deals with considerations regarding appropriate safety and service instrumentation. The determined closed loop control rules for temperature and position will be implemented in the detailed design. The Computer Aided Operator Decisions System (CAODS) will be used for prediction of hot spot temperature and thickness of oxidation layer using Baker-Just correlation. The proposed hybrid simulation system comprising of both virtual and real hardware will be in-cooperated for LORELEI verification. It will perform both integration cold tests for a partial hardware loop and virtual tests for the final I&C design

Standard Test Method for Electrical Performance of Photovoltaic Cells Using Reference Cells Under Simulated Sunlight

CERN Document Server

American Society for Testing and Materials. Philadelphia

2009-01-01

1.1 This test method covers the determination of the electrical performance of a photovoltaic cell under simulated sunlight by means of a calibrated reference cell procedure. 1.2 Electrical performance measurements are reported with respect to a select set of standard reporting conditions (SRC) (see Table 1) or to user-specified conditions. 1.2.1 The SRC or user-specified conditions include the cell temperature, the total irradiance, and the reference spectral irradiance distribution. 1.3 This test method is applicable only to photovoltaic cells with a linear response over the range of interest. 1.4 The cell parameters determined by this test method apply only at the time of test, and imply no past or future performance level. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this s...

Stability and Performance of Oxygen Electrodes for Reversible Solid Oxide Cells

Science.gov (United States)

Railsback, Justin Gary

Worldwide, governments are beginning to take action to reduce anthropogenic CO2 emissions in order to mitigate the extent of global climate change. The largest fraction of global CO2 emission comes from electrical power generation, which is rapidly being converted to wind and solar installations. The intermittent nature of renewable resources requires that large scale energy storage be implemented to ensure grid stability. Pumped hydro storage is currently the only technology available for large scale energy storage; however, pumped hydro remains geographically confined and susceptible to seasonal fluctuations and offers limited discharge hours. Recent system level models predict that reversible solid oxide cells may be a competitive solution, but two key advancements are required to realize the technology: low cell resistance (cell resistance, and when a cell is operated in electrolysis the oxygen electrode is known to degrade quickly. This work focuses on both aspects of the oxygen electrode. A Pr2NiO4 based electrode is developed that has improved phase stability and good polarization resistance ( 0.1 O•cm2 at 650 °C). The electrode is prepared by wet chemical impregnation (infiltration) of Pr2NiO4 precursors into a La0.9Sr 0.1Ga0.8Mg0.2O3 scaffold. Electrochemical data for a number cells is presented and the number of infiltrations is optimized. Preliminary life tests and x-ray data are presented. Pressurization of the oxygen electrode is predicted to decrease its polarization resistance and pressurization of the reversible solid oxide cell system is desirable to achieve high round-trip efficiency. The electrochemical performance of mixed electronic-ionic conducting electrodes has not been reported above 1 atm. Four candidate electrodes are examined under pressurization up to 10 atm: Pr2NiO4 infiltrated La0.9Sr0.1 Ga0.8Mg0.2O3, Sm0.5Sr 0.5CoO3 infiltrated Ce0.9Gd0.1O 2, single phase La0.6Sr0.4Co0.2Fe 0.8O3, and single phase Nd2NiO4. The role of the ion

Performance of a vanadium redox flow battery with tubular cell design

Science.gov (United States)

Ressel, Simon; Laube, Armin; Fischer, Simon; Chica, Antonio; Flower, Thomas; Struckmann, Thorsten

2017-07-01

We present a vanadium redox flow battery with a tubular cell design which shall lead to a reduction of cell manufacturing costs and the realization of cell stacks with reduced shunt current losses. Charge/discharge cycling and polarization curve measurements are performed to characterize the single test cell performance. A maximum current density of 70 mAcm-2 and power density of 142 Wl-1 (per cell volume) is achieved and Ohmic overpotential is identified as the dominant portion of the total cell overpotential. Cycling displays Coulomb efficiencies of ≈95% and energy efficiencies of ≈55%. During 113 h of operation a stable Ohmic cell resistance is observed.

Preliminary investigation of airgap electrospun silk-fibroin-based structures for ligament analogue engineering.

Science.gov (United States)

Sell, S A; McClure, M J; Ayres, C E; Simpson, D G; Bowlin, G L

2011-01-01

The process of electrospinning has proven to be highly beneficial for use in a number of tissue-engineering applications due to its ease of use, flexibility and tailorable properties. There have been many publications on the creation of aligned fibrous structures created through various forms of electrospinning, most involving the use of a metal target rotating at high speeds. This work focuses on the use of a variation known as airgap electrospinning, which does not use a metal collecting target but rather a pair of grounded electrodes equidistant from the charged polymer solution to create highly aligned 3D structures. This study involved a preliminary investigation and comparison of traditionally and airgap electrospun silk-fibroin-based ligament constructs. Structures were characterized with SEM and alignment FFT, and underwent porosity, permeability, and mechanical anisotropy evaluation. Preliminary cell culture with human dermal fibroblasts was performed to determine the degree of cellular orientation and penetration. Results showed airgap electrospun structures to be anisotropic with significantly increased porosity and cellular penetration compared to their traditionally electrospun counterparts.

Performance effects of coal-derived contaminants on the carbonate fuel cell

Energy Technology Data Exchange (ETDEWEB)

Pigeaud, A. [Energy Research Corp., Danbury, CT (United States); Wilemski, G. [Physical Sciences, Inc., Andover, MA (United States)

1993-05-01

Coal-derived contaminant studies have been pursued at ERC since the early 1980`s when the pace of carbonate fuel cell development began to markedly increase. Initial work was concerned with performance effects on laboratory and bench-scale carbonate fuel cells primarily due to sulfur compounds. Results have now also been obtained with respect to nine additional coal-gas contaminants, including volatile trace metal species. Thermochemical calculations, out-of-cell experiments, and cell performance as well as endurance testshave recently been conducted which have involved the following species: NH{sub 3}, H{sub 2}S [COS], HCl, AsH{sub 3}[As{sub 2}(v)], Zn(v), Pb(v), Cd(v), H{sub 2} Se, Hg(v), Sn(v). Employing thermochemically calculated results, thermogravimetric (TGA) and pre-, and post-test analytical data as well as fuel cell performance observations, it has been shown that there are four main mechanisms of contaminant interaction with the carbonate fuel cell. These have been formulated into performance models for six significant contaminant species, thus providing long-term endurance estimations.

Performance effects of coal-derived contaminants on the carbonate fuel cell

Energy Technology Data Exchange (ETDEWEB)

Pigeaud, A. (Energy Research Corp., Danbury, CT (United States)); Wilemski, G. (Physical Sciences, Inc., Andover, MA (United States))

1993-01-01

Coal-derived contaminant studies have been pursued at ERC since the early 1980's when the pace of carbonate fuel cell development began to markedly increase. Initial work was concerned with performance effects on laboratory and bench-scale carbonate fuel cells primarily due to sulfur compounds. Results have now also been obtained with respect to nine additional coal-gas contaminants, including volatile trace metal species. Thermochemical calculations, out-of-cell experiments, and cell performance as well as endurance testshave recently been conducted which have involved the following species: NH[sub 3], H[sub 2]S [COS], HCl, AsH[sub 3][As[sub 2](v)], Zn(v), Pb(v), Cd(v), H[sub 2] Se, Hg(v), Sn(v). Employing thermochemically calculated results, thermogravimetric (TGA) and pre-, and post-test analytical data as well as fuel cell performance observations, it has been shown that there are four main mechanisms of contaminant interaction with the carbonate fuel cell. These have been formulated into performance models for six significant contaminant species, thus providing long-term endurance estimations.

TITAN Legal Weight Truck cask preliminary design report

International Nuclear Information System (INIS)

1990-04-01

The Preliminary Design of the TITAN Legal Weight Truck (LWT) Cask System and Ancillary Equipment is presented in this document. The scope of this document includes the LWT cask with fuel baskets, impact limiters, and lifting and tiedown features; the cask support system for transportation; intermodal transfer skid; personnel barrier; and cask lifting yoke assembly. The results of the tradeoff studies and evaluations that were performed during the preliminary design are presented in Appendix A to this report. 51 figs., 17 tabs

Experimental Study and Comparison of Various Designs of Gas Flow Fields to PEM Fuel Cells and Cell Stack Performance

International Nuclear Information System (INIS)

Liu, Hong; Li, Peiwen; Juarez-Robles, Daniel; Wang, Kai; Hernandez-Guerrero, Abel

2014-01-01

In this study, a significant number of experimental tests to proton exchange membrane (PEM) fuel cells were conducted to investigate the effect of gas flow fields on fuel cell performance. Graphite plates with various flow field or flow channel designs, from literature survey and also novel designs by the authors, were used for the PEM fuel cell assembly. The fabricated fuel cells have an effective membrane area of 23.5 cm 2 . The results showed that the serpentine flow channel design is still favorable, giving the best single fuel cell performance amongst all the studied flow channel designs. A novel symmetric serpentine flow field was proposed for a relatively large sized fuel cell application. Four fuel cell stacks each including four cells were assembled using different designs of serpentine flow channels. The output power performances of fuel cell stacks were compared and the novel symmetric serpentine flow field design is recommended for its very good performance.

Final Report - Effects of Impurities on Fuel Cell Performance and Durability

Energy Technology Data Exchange (ETDEWEB)

Trent Molter

2012-08-18

This program is focused on the experimental determination of the effects of key hydrogen side impurities on the performance of PEM fuel cells. Experimental data has been leveraged to create mathematical models that predict the performance of PEM fuel cells that are exposed to specific impurity streams. These models are validated through laboratory experimentation and utilized to develop novel technologies for mitigating the effects of contamination on fuel cell performance. Results are publicly disseminated through papers, conference presentations, and other means.

Preliminary design and definition of field experiments for welded tuff rock mechanics program

International Nuclear Information System (INIS)

Zimmerman, R.M.

1982-06-01

The preliminary design contains objectives, typical experiment layouts, definitions of equipment and instrumentation, test matrices, preliminary design predictive modeling results for five experiments, and a definition of the G-Tunnel Underground Facility (GTUF) at the Nevada Test Site where the experiments are to be located. Experiments described for investigations in welded tuff are the Small Diameter Heater, Unit Cell-Canister Scale, Heated Block, Rocha Slot, and Miniature Heater

In-cell facility for performing mechanical-property tests on irradiated cladding

International Nuclear Information System (INIS)

Yaggee, F.L.; Haglund, R.C.; Mattas, R.F.

1978-11-01

A new facility was developed for testing cladding sections of LWR fuel rods. This facility and the accompanying test procedures have improved the level of in-cell mechanical-testing capabilities, making them comparable to existing capabilities for unirradiated cladding. The new facility is currently being used to study the susceptibility of irradiated Zircaloy cladding from LWR fuel rods to iodine stress-corrosion cracking. Preliminary testing results indicate a systematic effect of temperature, stress and irradiation on the susceptibility of annealed and stress-relieved Zircaloy-2. Experimental data obtained to date are being used to develop a stress-corrosion cracking model for LWR fuel rod failure. SEM examination of the undisturbed fracture surface of specimens that failed by pinhole leakage provides useful information on crack propagation and morphology

Performances of 250 Amp-hr lithium/thionyl chloride cells

Science.gov (United States)

Goualard, Jacques

1991-01-01

A 250 Ah lithium thionyl chloride battery is being developed for a booster rocket engine. Extensive cell testing is running to evaluate functional and safety performances. Some results are presented. The lithium/thionyl chloride batteries were selected for their high energy density (low weight) as compared to other sources. The temperature of a lower weight item will be more sensitive to variations of internal and external heat fluxes than a heavier one. The use of high energy density L/TC batteries is subjected to stringent thermal environments to have benefit of energy density and to stay safe in any conditions. The battery thermal environment and discharge rate have to be adjusted to obtain the right temperature range at cell level, to have the maximum performances. Voltage and capacity are very sensitive to temperature. This temperature is the cell internal actual temperature during discharge. This temperature is directed by external thermal environment and by cell internal heat dissipation, i.e., cell actual voltage.

Performances of 250 Amp-hr lithium/thionyl chloride cells

Science.gov (United States)

Goualard, Jacques

1991-05-01

A 250 Ah lithium thionyl chloride battery is being developed for a booster rocket engine. Extensive cell testing is running to evaluate functional and safety performances. Some results are presented. The lithium/thionyl chloride batteries were selected for their high energy density (low weight) as compared to other sources. The temperature of a lower weight item will be more sensitive to variations of internal and external heat fluxes than a heavier one. The use of high energy density L/TC batteries is subjected to stringent thermal environments to have benefit of energy density and to stay safe in any conditions. The battery thermal environment and discharge rate have to be adjusted to obtain the right temperature range at cell level, to have the maximum performances. Voltage and capacity are very sensitive to temperature. This temperature is the cell internal actual temperature during discharge. This temperature is directed by external thermal environment and by cell internal heat dissipation, i.e., cell actual voltage.

Preliminary disposal limits, plume interaction factors, and final disposal limits

Energy Technology Data Exchange (ETDEWEB)

Flach, G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2018-01-11

In the 2008 E-Area Performance Assessment (PA), each final disposal limit was constructed as the product of a preliminary disposal limit and a plume interaction factor. The following mathematical development demonstrates that performance objectives are generally expected to be satisfied with high confidence under practical PA scenarios using this method. However, radionuclides that experience significant decay between a disposal unit and the 100-meter boundary, such as H-3 and Sr-90, can challenge performance objectives, depending on the disposed-of waste composition, facility geometry, and the significance of the plume interaction factor. Pros and cons of analyzing single disposal units or multiple disposal units as a group in the preliminary disposal limits analysis are also identified.

Performance of Platinum Nanoparticles / Multiwalled Carbon Nanotubes / Bacterial Cellulose Composite as Anode Catalyst for Proton Exchange Membrane Fuel Cells

Directory of Open Access Journals (Sweden)

Henry Fonda Aritonang

2017-05-01

Full Text Available Highly dispersed platinum (Pt nanoparticles / multiwalled carbon nanotubes (MWCNTs on bacterial cellulose (BC as anode catalysts for proton exchange membrane fuel cells (PEMFC were prepared with various precursors and their electro-catalytic activities towards hydrogen oxidation at 70 oC under non-humidified conditions. The composite was prepared by deposition of Pt nanoparticles and MWCNTs on BC gel by impregnation method using a water solution of metal precursors and MWCNTs followed by reducing reaction using a hydrogen gas. The composite was characterized by using TEM (transmission electron microscopy, EDS (energy dispersive spectroscopy, and XRD (X-ray diffractometry techniques. TEM images and XRD patterns both lead to the observation of spherical metallic Pt nanoparticles with mean diameter of 3-11 nm well impregnated into the BC fibrils. Preliminary tests on a single cell indicate that renewable BC is a good prospect to be explored as a membrane in fuel cell field. Copyright © 2017 BCREC Group. All rights reserved Received: 21st November 2016; Revised: 26th February 2017; Accepted: 27th February 2017 How to Cite: Aritonang, H.F., Kamu, V.S., Ciptati, C., Onggo, D., Radiman, C.L. (2017. Performance of Platinum Nanoparticles / Multiwalled Carbon Nanotubes / Bacterial Cellulose Composite as Anode Catalyst for Proton Exchange Membrane Fuel Cells. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (2: 287-292 (doi:10.9767/bcrec.12.2.803.287-292 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.12.2.803.287-292

Chemistry and preliminary environmental effects of mixtures of triisopropyl phosphite, Bis-(2-ethylexyl)-phosphonate, and sulfur. Final report

Energy Technology Data Exchange (ETDEWEB)

Cataldo, D.A.; Harvey, S.D.; McVeety, B.D.; Fellows, R.J.; Van Noris, P.

1991-12-01

The present studies were performed to evaluate the reaction chemistry and preliminary biotic impacts of BIS, TIP, and TIPS. Reaction chemistry studies were designed to simulate in-flight mixing characteristics. The binary mixture undergoes rapid and nearly complete reaction. The final products released to the environment are TIPS and excess elemental sulfur. There is an apparent species sensitivity difference in algae for the simulants BIS, TIP, and TIPS, with Chlorella being more sensitive than Selenastrum based on cell number studies. However, the extent of adverse effects was not excessive for either algal species. There was no apparent effect of TIP or TIPS on the electron transport systems of isolated chloroplasts at the concentration tested (10 ppm). In general, it is unlikely that environmental release of these products would have significant or lasting effects, based on the preliminary algal tests and electron transport studies.

Preliminary crystallographic analysis of a possible transcription factor encoded by the mimivirus L544 gene

International Nuclear Information System (INIS)

Ciaccafava, Alexandre; Lartigue, Audrey; Mansuelle, Pascal; Jeudy, Sandra; Abergel, Chantal

2011-01-01

The mimivirus L544 gene product was expressed in E. coli and crystallized; preliminary phasing of a MAD data set was performed using the selenium signal present in a crystal of recombinant selenomethionine-substituted protein. Mimivirus is the prototype of a new family (the Mimiviridae) of nucleocytoplasmic large DNA viruses (NCLDVs), which already include the Poxviridae, Iridoviridae, Phycodnaviridae and Asfarviridae. Mimivirus specifically replicates in cells from the genus Acanthamoeba. Proteomic analysis of purified mimivirus particles revealed the presence of many subunits of the DNA-directed RNA polymerase II complex. A fully functional pre-transcriptional complex appears to be loaded in the virions, allowing mimivirus to initiate transcription within the host cytoplasm immediately upon infection independently of the host nuclear apparatus. To fully understand this process, a systematic study of mimivirus proteins that are predicted (by bioinformatics) or suspected (by proteomic analysis) to be involved in transcription was initiated by cloning and expressing them in Escherichia coli in order to determine their three-dimensional structures. Here, preliminary crystallographic analysis of the recombinant L544 protein is reported. The crystals belonged to the orthorhombic space group C222 1 with one monomer per asymmetric unit. A MAD data set was used for preliminary phasing using the selenium signal present in a selenomethionine-substituted protein crystal

Performance of proton exchange membrane fuel cells at elevated temperature

International Nuclear Information System (INIS)

Shyu, Jin-Cherng; Hsueh, Kan-Lin; Tsau, Fanghei

2011-01-01

Highlights: → At 1 atm, cell has best performance (∼1300 mA/cm at 0.6 V) at 100 deg. C and RH = 100%. → The A value in Eq. increased with increases in the back pressure and RH. →R i dramatically decreased at back pressure of 1 atm. → At each RH, R i decreased and then increased as cell temperature increased at 1 atm. - Abstract: The polarization curves of a single PEMFC having a Nafion membrane fed with H 2 /O 2 with relative humidity (RH) of 35%, 70% and 100% were measured at cell temperatures ranging from 65 deg. C to 120 deg. C at back pressures of 0 atm and 1 atm, respectively. Measured results showed that the best cell performance at 0.6 V operated within 65-120 deg. C at zero back pressure was 1000 mA cm -2 at 65 deg. C and RH = 100%, while the best cell performance at 1 atm back pressure was 1300 mA cm -2 at 100 deg. C and RH = 100%. Based on the analysis of impedance data measured at anode and cathode humidification temperatures of 90 deg. C and cell temperature of 100 deg. C at back pressures of 0 and 1 atm (90-100p0 and 90-100p1), it could be found that the membrane resistance was reduced and the catalyst became more active as the back pressure increases. The present results showed that increasing back pressure was able to dramatically improve cell performance and the effect of the back pressure surpassed that of humidification in the internal resistance of cell.

Silicon Solar Cell Process Development, Fabrication and Analysis, Phase 1

Science.gov (United States)

Yoo, H. I.; Iles, P. A.; Tanner, D. P.

1979-01-01

Solar cells from RTR ribbons, EFG (RF and RH) ribbons, dendritic webs, Silso wafers, cast silicon by HEM, silicon on ceramic, and continuous Czochralski ingots were fabricated using a standard process typical of those used currently in the silicon solar cell industry. Back surface field (BSF) processing and other process modifications were included to give preliminary indications of possible improved performance. The parameters measured included open circuit voltage, short circuit current, curve fill factor, and conversion efficiency (all taken under AM0 illumination). Also measured for typical cells were spectral response, dark I-V characteristics, minority carrier diffusion length, and photoresponse by fine light spot scanning. the results were compared to the properties of cells made from conventional single crystalline Czochralski silicon with an emphasis on statistical evaluation. Limited efforts were made to identify growth defects which will influence solar cell performance.

Fort Hood Solar Total Energy Project. Volume II. Preliminary design. Part 2. System performance and supporting studies. Final report

Energy Technology Data Exchange (ETDEWEB)

None,

1979-01-01

The preliminary design developed for the Solar Total Energy System to be installed at Fort Hood, Texas, is presented. System performance analysis and evaluation are described. Feedback of completed performance analyses on current system design and operating philosophy is discussed. The basic computer simulation techniques and assumptions are described and the resulting energy displacement analysis is presented. Supporting technical studies are presented. These include health and safety and reliability assessments; solar collector component evaluation; weather analysis; and a review of selected trade studies which address significant design alternatives. Additional supporting studies which are generally specific to the installation site are reported. These include solar availability analysis; energy load measurements; environmental impact assessment; life cycle cost and economic analysis; heat transfer fluid testing; meteorological/solar station planning; and information dissemination. (WHK)

Indoor Light Performance of Coil Type Cylindrical Dye Sensitized Solar Cells.

Science.gov (United States)

Kapil, Gaurav; Ogomi, Yuhei; Pandey, Shyam S; Ma, Tingli; Hayase, Shuzi

2016-04-01

A very good performance under low/diffused light intensities is one of the application areas in which dye-sensitized solar cells (DSSCs) can be utilized effectively compared to their inorganic silicon solar cell counterparts. In this article, we have investigated the 1 SUN and low intensity fluorescent light performance of Titanium (Ti)-coil based cylindrical DSSC (C-DSSC) using ruthenium based N719 dye and organic dyes such as D205 and Y123. Electrochemical impedance spectroscopic results were analyzed for variable solar cell performances. Reflecting mirror with parabolic geometry as concentrator was also utilized to tap diffused light for indoor applications. Fluorescent light at relatively lower illumination intensities (0.2 mW/cm2 to 0.5 mW/cm2) were used for the investigation of TCO-less C-DSSC performance with and without reflector geometry. Furthermore, the DSSC performances were analyzed and compared with the commercially available amorphous silicon based solar cell for indoor applications.

Performance study of solar cell arrays based on a Trough Concentrating Photovoltaic/Thermal system

International Nuclear Information System (INIS)

Li, Ming; Ji, Xu; Li, Guoliang; Wei, Shengxian; Li, YingFeng; Shi, Feng

2011-01-01

Highlights: → The performances of solar cell arrays based on a Trough Concentrating Photovoltaic/Thermal (TCPV/T) system have been studied. → The optimum concentration ratios for the single crystalline silicon cell, the Super cells and the GaAs cells were studied by experiments. → The influences between the solar cell's performance and the series resistances, the working temperature, solar irradiation intensity were explored. - Abstract: The performances of solar cell arrays based on a Trough Concentrating Photovoltaic/Thermal (TCPV/T) system have been studied via both experiment and theoretical calculation. The I-V characteristics of the solar cell arrays and the output performances of the TCPV/T system demonstrated that among the investigated four types of solar cell arrays, the triple junction GaAs cells possessed good performance characteristics and the polysilicon cells exhibited poor performance characteristics under concentrating conditions. The optimum concentration ratios for the single crystalline silicon cell, the Super cells and the GaAs cells were also studied by experiments. The optimum concentration ratios for the single crystalline silicon cells and Super cells were 4.23 and 8.46 respectively, and the triple junction GaAs cells could work well at higher concentration ratio. Besides, some theoretical calculations and experiments were performed to explore the influences of the series resistances and the working temperature. When the series resistances R s changed from 0 Ω to 1 Ω, the maximum power P m of the single crystalline silicon, the polycrystalline silicon, the Super cell and the GaAs cell arrays decreased by 67.78%, 74.93%, 77.30% and 58.07% respectively. When the cell temperature increased by 1 K, the short circuit current of the four types of solar cell arrays decreased by 0.11818 A, 0.05364 A, 0.01387 A and 0.00215 A respectively. The research results demonstrated that the output performance of the solar cell arrays with lower

Preliminary experience on the use of the Adnatest® system for detection of circulating tumor cells in prostate cancer patients.

Science.gov (United States)

Todenhöfer, Tilman; Hennenlotter, Jörg; Feyerabend, Susan; Aufderklamm, Stefan; Mischinger, Johannes; Kühs, Ursula; Gerber, Valentina; Fetisch, Jasmin; Schilling, David; Hauch, Siegfried; Stenzl, Arnulf; Schwentner, Christian

2012-08-01

The Adnatest® system combines immunomagnetic enrichment of epithelial cells with polymerase chain reaction for prostate cancer (PC)-specific transcripts for the detection circulating tumor cells (CTCs). We evaluated the Adnatest® in patients with castration-resistant PC receiving docetaxel chemotherapy. CTCs were assessed in 16 patients with castration-resistant PC before cycles one and three of chemotherapy. Furthermore, markers of stem cells and epithelial-mesenchymal transition were assessed. Treatment response was assessed by imaging and prostate-specific antigen measurements. Before chemotherapy, 11 patients were Adnatest®-positive whereas five patients were Adnatest®-positive before cycle three. A positive Adnatest® correlated with radiological progression (p=0.02). Rates of disease progression in epidermal growth factor receptor (EGFR)-positive and -negative patients were 100% and 7.7% (p=0.03). In this preliminary study, the Adnatest® detected CTCs in a considerable proportion of patients with castration-resistant PC. First data on certain markers (EGFR and aldehyd dehydrogenase 1) encourage future studies investigating transcripts predicting treatment response.

Preliminary screening and identification of the peptide binding to hepatocarcinoma cell

International Nuclear Information System (INIS)

Zhu Xiaohua; Wu Ha

2004-01-01

Objective: The present study was performed to screen and isolate homing peptides that bind specifically, or preferentially, to hepatocarcinoma cells using phage display of random peptide library with the purpose of developing a new peptide which may be potentially used as target delivery carrier in the biological target diagnosis or therapy for liver cancer. Methods: A peptide 12-mer phage display library was used to screen and isolate peptide that bind to human hepatocarcinoma cell, and four rounds subtractive panning were carried out with the human hepatocarcinoma cell line HepG2 as the target. The affinities of selected phage clones to human hepatocarcinoma cell were determined with ELISA and compared with human liver cell and other tumor cells of different tissue origins respectively. In addition, the binding site in the tumor cells was observed with immunofluorescence analysis under confocal light microscopy. The amino acid sequences of phages that bind HepG2 specifically were deduced though DNA sequencing. Based on the results of DNA sequence, a 16-mer peptide (WH16) was designed and synthesized. Binding ability of the new peptide WH16 was determined with competitive inhibition test. Results: After four rounds panning, the phages that bound to and internalized in human hepatocarcinoma cell were isolated. ELISA and immunofluorescence analysis confirmed the affinity of these phages to hepatpcarcinoma cells 56.57%(17/30) of the isolated phages displayed repeated sequence FLLEPHLMDTSM, and FLEP was defined as conservative motif. Binding of the selected phage to HepG2 cells was inhibited by synthesized peptide WH16, which strongly support that cellular binding of phage is mediated though its displayed peptide and WH16 can also bind to HepG2. Conclusion: It is feasible to screen and isolate homing peptides that bind specifically, or preferentially, to hepatocarcinoma cells using phage display of random peptide libraries. The sequence of peptide that can bind to

Preliminary screening and identification of the peptide binding to hepatocarcinoma cell

Energy Technology Data Exchange (ETDEWEB)

Xiaohua, Zhu; Ha, Wu [Department of Nuclear Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China)

2004-07-01

Objective: The present study was performed to screen and isolate homing peptides that bind specifically, or preferentially, to hepatocarcinoma cells using phage display of random peptide library with the purpose of developing a new peptide which may be potentially used as target delivery carrier in the biological target diagnosis or therapy for liver cancer. Methods: A peptide 12-mer phage display library was used to screen and isolate peptide that bind to human hepatocarcinoma cell, and four rounds subtractive panning were carried out with the human hepatocarcinoma cell line HepG2 as the target. The affinities of selected phage clones to human hepatocarcinoma cell were determined with ELISA and compared with human liver cell and other tumor cells of different tissue origins respectively. In addition, the binding site in the tumor cells was observed with immunofluorescence analysis under confocal light microscopy. The amino acid sequences of phages that bind HepG2 specifically were deduced though DNA sequencing. Based on the results of DNA sequence, a 16-mer peptide (WH16) was designed and synthesized. Binding ability of the new peptide WH16 was determined with competitive inhibition test. Results: After four rounds panning, the phages that bound to and internalized in human hepatocarcinoma cell were isolated. ELISA and immunofluorescence analysis confirmed the affinity of these phages to hepatpcarcinoma cells 56.57%(17/30) of the isolated phages displayed repeated sequence FLLEPHLMDTSM, and FLEP was defined as conservative motif. Binding of the selected phage to HepG2 cells was inhibited by synthesized peptide WH16, which strongly support that cellular binding of phage is mediated though its displayed peptide and WH16 can also bind to HepG2. Conclusion: It is feasible to screen and isolate homing peptides that bind specifically, or preferentially, to hepatocarcinoma cells using phage display of random peptide libraries. The sequence of peptide that can bind to

New technologies and new performances of the JCMT radio-telescope: a preliminary design study

Science.gov (United States)

Mian, S.; De Lorenzi, S.; Ghedin, L.; Rampini, F.; Marchiori, G.; Craig, S.

2012-09-01

With a diameter of 15m the James Clerk Maxwell Telescope (JCMT) is the largest astronomical telescope in the world designed specifically to operate in the submillimeter wavelength region of the spectrum. It is situated close to the summit of Mauna Kea, Hawaii, at an altitude of 4092m. Its primary reflector currently consists of a steel geodesic supporting structure and pressed aluminium panels on a passive mount. The major issues of the present reflector are its thermal stability and its panels deterioration. A preliminary design study for the replacement of the JCMT antenna dish is here presented. The requested shape error for the new reflector is <20μm RMS. The proposed solution is based on a semi-monocoque backing structure made of CFRP and on high precision electroformed panels. The choice of CFRP for the backing structure allows indeed to improve the antenna performance in terms of both stiffness and thermal stability, so that the required surface accuracy of the primary can be achieved even by adopting a passive panels system. Moreover thanks to CFRP, a considerable weight reduction of the elevation structure can be attained. The performance of the proposed solution for the JCMT antenna has been investigated through FE analyses and the assessed deformation of the structure under different loading cases has been taken into account for subsequent error budgeting. Results show that the proposed solution is in line with the requested performance. With this new backing structure, the JCMT would have the largest CFRP reflector ever built.

Bovine annulus fibrosus cell lines isolated from intervertebral discs

Directory of Open Access Journals (Sweden)

Petra Kraus

2016-12-01

Full Text Available The adult bovine (Bos taurus intervertebral disc is primarily comprised of two major tissue types: The outer annulus fibrosus (AF and the central nucleus pulposus (NP. We isolated several primary cell lineages of passage (P 0 cells from the AF tissue omitting typically used enzymatic tissue digestion protocols. The cells grow past p10 without signs of senescence in DMEM + 10% FCS on 0.1% gelatin coated/uncoated surfaces of standard cell culture plates and survive freeze-thawing. Preliminary analysis of the AF derived cells for expression of the two structural genes Col1a1 and Col2a1 was performed by PISH recapitulating the expression observed in vivo.

Preliminary melter performance assessment report

International Nuclear Information System (INIS)

Elliott, M.L.; Eyler, L.L.; Mahoney, L.A.; Cooper, M.F.; Whitney, L.D.; Shafer, P.J.

1994-08-01

The Melter Performance Assessment activity, a component of the Pacific Northwest Laboratory's (PNL) Vitrification Technology Development (PVTD) effort, was designed to determine the impact of noble metals on the operational life of the reference Hanford Waste Vitrification Plant (HWVP) melter. The melter performance assessment consisted of several activities, including a literature review of all work done with noble metals in glass, gradient furnace testing to study the behavior of noble metals during the melting process, research-scale and engineering-scale melter testing to evaluate effects of noble metals on melter operation, and computer modeling that used the experimental data to predict effects of noble metals on the full-scale melter. Feed used in these tests simulated neutralized current acid waste (NCAW) feed. This report summarizes the results of the melter performance assessment and predicts the lifetime of the HWVP melter. It should be noted that this work was conducted before the recent Tri-Party Agreement changes, so the reference melter referred to here is the Defense Waste Processing Facility (DWPF) melter design

Device Engineering Towards Improved Tin Sulfide Solar Cell Performance and Performance Reproducibility

Energy Technology Data Exchange (ETDEWEB)

Steinmann, Vera; Chakraborty, Rupak; Rekemeyer, Paul; Siol, Sebastian; Martinot, Loic; Polizzotti, Alex; Yang, Chuanxi; Hartman, Katy; Gradecak, Silvija; Zakutayev, Andriy; Gordon, Roy G.; Buonassisi, Tonio

2016-11-21

As novel absorber materials are developed and screened for their photovoltaic (PV) properties, the challenge remains to rapidly test promising candidates in high-performing PV devices. There is a need to engineer new compatible device architectures, including the development of novel transparent conductive oxides and buffer layers. Here, we consider the two approaches of a substrate-style and a superstrate-style device architecture for novel thin-film solar cells. We use tin sulfide as a test absorber material. Upon device engineering, we demonstrate new approaches to improve device performance and performance reproducibility.

2010 Survey on cell phone use while performing cardiopulmonary bypass.

Science.gov (United States)

Smith, T; Darling, E; Searles, B

2011-09-01

Cell phone use in the U.S. has increased dramatically over the past decade and text messaging among adults is now mainstream. In professions such as perfusion, where clinical vigilance is essential to patient care, the potential distraction of cell phones may be especially problematic. However, the extent of this as an issue is currently unknown. Therefore, the purpose of this study was to (1) determine the frequency of cell phone use in the perfusion community, and (2) to identify concerns and opinions among perfusionists regarding cell phone use. In October 2010, a link to a 19-question survey (surveymonkey.com) was posted on the AmSECT (PerfList) and Perfusion.com (PerfMail) forums. There were 439 respondents. Demographic distribution is as follows; Chief Perfusionist (30.5%), Staff Perfusionist (62.0%), and Other (7.5%), with age ranges of 20-30 years (14.2%), 30-40 years (26.5%), 40-50 years (26.7%), 50-60 years (26.7%), >60 years (5.9%). The use of a cell phone during the performance of cardiopulmonary bypass (CPB) was reported by 55.6% of perfusionists. Sending text messages while performing CPB was acknowledged by 49.2%, with clear generational differences detected when cross-referenced with age groups. For smart phone features, perfusionists report having accessed e-mail (21%), used the internet (15.1%), or have checked/posted on social networking sites (3.1%) while performing CPB. Safety concerns were expressed by 78.3% who believe that cell phones can introduce a potentially significant safety risk to patients. Speaking on a cell phone and text messaging during CPB are regarded as "always an unsafe practice" by 42.3% and 51.7% of respondents, respectively. Personal distraction by cell phone use that negatively affected performance was admitted by 7.3%, whereas witnessing another perfusionist distracted with phone/text while on CPB was acknowledged by 33.7% of respondents. This survey suggests that the majority of perfusionists believe cell phones raise

HEU benchmark calculations and LEU preliminary calculations for IRR-1

International Nuclear Information System (INIS)

Caner, M.; Shapira, M.; Bettan, M.; Nagler, A.; Gilat, J.

2004-01-01

We performed neutronics calculations for the Soreq Research Reactor, IRR-1. The calculations were done for the purpose of upgrading and benchmarking our codes and methods. The codes used were mainly WIMS-D/4 for cell calculations and the three dimensional diffusion code CITATION for full core calculations. The experimental flux was obtained by gold wire activation methods and compared with our calculated flux profile. The IRR-1 is loaded with highly enriched uranium fuel assemblies, of the plate type. In the framework of preparation for conversion to low enrichment fuel, additional calculations were done assuming the presence of LEU fresh fuel. In these preliminary calculations we investigated the effect on the criticality and flux distributions of the increase of U-238 loading, and the corresponding uranium density.(author)

The TMI Regenerative Solid Oxide Fuel Cell

Science.gov (United States)

Cable, Thomas L.; Ruhl, Robert C.; Petrik, Michael

1996-01-01

Energy storage and production in space requires rugged, reliable hardware which minimizes weight, volume, and maintenance while maximizing power output and usable energy storage. Systems generally consist of photovoltaic solar arrays which operate (during sunlight cycles) to provide system power and regenerate fuel (hydrogen) via water electrolysis and (during dark cycles) fuel cells convert hydrogen into electricity. Common configurations use two separate systems (fuel cell and electrolyzer) in conjunction with photovoltaic cells. Reliability, power to weight and power to volume ratios could be greatly improved if both power production (fuel cells) and power storage (electrolysis) functions can be integrated into a single unit. The solid oxide fuel cell (SOFC) based design integrates fuel cell and electrolyzer functions and potentially simplifies system requirements. The integrated fuel cell/electrolyzer design also utilizes innovative gas storage concepts and operates like a rechargeable 'hydrogen-oxygen battery'. Preliminary research has been completed on improved H2/H20 electrode (SOFC anode/electrolyzer cathode) materials for regenerative fuel cells. Tests have shown improved cell performance in both fuel and electrolysis modes in reversible fuel cell tests. Regenerative fuel cell efficiencies, ratio of power out (fuel cell mode) to power in (electrolyzer mode), improved from 50 percent using conventional electrode materials to over 80 percent. The new materials will allow a single SOFC system to operate as both the electolyzer and fuel cell. Preliminary system designs have also been developed to show the technical feasibility of using the design for space applications requiring high energy storage efficiencies and high specific energy. Small space systems also have potential for dual-use, terrestrial applications.

How the relative permittivity of solar cell materials influences solar cell performance

DEFF Research Database (Denmark)

Crovetto, Andrea; Huss-Hansen, Mathias K.; Hansen, Ole

2017-01-01

of the materials permittivity on the physics and performance of the solar cell by means of numerical simulation supported by analytical relations. We demonstrate that, depending on the specific solar cell configuration and materials properties, there are scenarios where the relative permittivity has a major......The relative permittivity of the materials constituting heterojunction solar cells is usually not considered as a design parameter when searching for novel combinations of heterojunction materials. In this work, we investigate the validity of such an approach. Specifically, we show the effect...... the heterojunction partner has a high permittivity, solar cells are consistently more robust against several non-idealities that are especially likely to occur in early-stage development, when the device is not yet optimized....

Cooling via one hand improves physical performance in heat-sensitive individuals with Multiple Sclerosis: A preliminary study

Directory of Open Access Journals (Sweden)

Murray Julie

2008-05-01

Full Text Available Abstract Background Many individuals afflicted with multiple sclerosis (MS experience a transient worsening of symptoms when body temperature increases due to ambient conditions or physical activity. Resulting symptom exacerbations can limit performance. We hypothesized that extraction of heat from the body through the subcutaneous retia venosa that underlie the palmar surfaces of the hands would reduce exercise-related heat stress and thereby increase the physical performance capacity of heat-sensitive individuals with MS. Methods Ten ambulatory MS patients completed one or more randomized paired trials of walking on a treadmill in a temperate environment with and without cooling. Stop criteria were symptom exacerbation and subjective fatigue. The cooling treatment entailed inserting one hand into a rigid chamber through an elastic sleeve that formed an airtight seal around the wrist. A small vacuum pump created a -40 mm Hg subatmospheric pressure enviinside the chamber where the palmar surface of the hand rested on a metal surface maintained at 18–22°C. During the treatment trials, the device was suspended from above the treadmill on a bungee cord so the subjects could comfortably keep a hand in the device without having to bear its weight while walking on the treadmill. Results When the trials were grouped by treatment only, cooling treatment increased exercise durations by 33% (43.6 ± 17.1 min with treatment vs. 32.8 ± 10.9 min. without treatment, mean ± SD, p -6, paired t-test, n = 26. When the average values were calculated for the subjects who performed multiple trials before the treatment group results were compared, cooling treatment increased exercise duration by 35% (42.8 ± 16.4 min with treatment vs. 31.7 ± 9.8 min. without treatment, mean ± SD, p Conclusion These preliminary results suggest that utilization of the heat transfer capacity of the non-hairy skin surfaces can enable temperature-sensitive individuals with MS to

Effects of cadmium electrode properties on nickel-cadmium cell performance

International Nuclear Information System (INIS)

Zimmerman, A.H.

1986-01-01

Tests have been conducted on a number of nickel-cadmium cells that have exhibited a variety of performance problems, ranging from high voltages and pressures during overcharge to low capacity. The performance problems that have been specifically linked to the cadmium electrode are primarily related to two areas, poor sinter and the buildup of excessive pressure during overcharge. A number of specific nickel-cadmium cell and cadmium electrode characterists have been studied in this work to determine what the effects of poor sinter are, and to determine what factors are important in causing excessive pressures during overcharge in cells that otherwise appear normal. Several of the tests appear suitable for screening cells and electrodes for such problems

High performance direct methanol fuel cell with thin electrolyte membrane

Science.gov (United States)

Wan, Nianfang

2017-06-01

A high performance direct methanol fuel cell is achieved with thin electrolyte membrane. 320 mW cm-2 of peak power density and over 260 mW cm-2 at 0.4 V are obtained when working at 90 °C with normal pressure air supply. It is revealed that the increased anode half-cell performance with temperature contributes primarily to the enhanced performance at elevated temperature. From the comparison of iR-compensated cathode potential of methanol/air with that of H2/air fuel cell, the impact of methanol crossover on cathode performance decreases with current density and becomes negligible at high current density. Current density is found to influence fuel efficiency and methanol crossover significantly from the measurement of fuel efficiency at different current density. At high current density, high fuel efficiency can be achieved even at high temperature, indicating decreased methanol crossover.

Comparison of the Cellient(™) automated cell block system and agar cell block method.

Science.gov (United States)

Kruger, A M; Stevens, M W; Kerley, K J; Carter, C D

2014-12-01

To compare the Cellient(TM) automated cell block system with the agar cell block method in terms of quantity and quality of diagnostic material and morphological, histochemical and immunocytochemical features. Cell blocks were prepared from 100 effusion samples using the agar method and Cellient system, and routinely sectioned and stained for haematoxylin and eosin and periodic acid-Schiff with diastase (PASD). A preliminary immunocytochemical study was performed on selected cases (27/100 cases). Sections were evaluated using a three-point grading system to compare a set of morphological parameters. Statistical analysis was performed using Fisher's exact test. Parameters assessing cellularity, presence of single cells and definition of nuclear membrane, nucleoli, chromatin and cytoplasm showed a statistically significant improvement on Cellient cell blocks compared with agar cell blocks (P cell groups, PASD staining or the intensity or clarity of immunocytochemical staining. A discrepant immunocytochemistry (ICC) result was seen in 21% (13/63) of immunostains. The Cellient technique is comparable with the agar method, with statistically significant results achieved for important morphological features. It demonstrates potential as an alternative cell block preparation method which is relevant for the rapid processing of fine needle aspiration samples, malignant effusions and low-cellularity specimens, where optimal cell morphology and architecture are essential. Further investigation is required to optimize immunocytochemical staining using the Cellient method. © 2014 John Wiley & Sons Ltd.

A preliminary model for estimating the first wall lifetime of a fusion reactor

International Nuclear Information System (INIS)

Daenner, W.

1975-02-01

The estimation of the first wall lifetime is a necessary basis for predicting the availability of a fusion power plant. In order to do this, an analytical model was prepared and programmed for the computer which calculates the temperature and stress load of the first wall from the principal design parameters and quotes them against the relevant material properties. Neither the analytical model nor the information about the material performance is yet complete so that the answers obtained from the program are very preliminary. This situation is underlined by the results of sample calculations performed for the CTRD blanket module cell. The results obtained for vanadium and vanadium alloys show a strong dependence of the lifetime on the irradiation creep and the ductility of these materials. Completion of this model is envisaged as soon as the missing information becomes available. (orig.) [de

Polybenzimidazoles based on high temperature polymer electrolyte fuel cells

Energy Technology Data Exchange (ETDEWEB)

Linares Leon, Jose Joaquin; Camargo, Ana Paula M.; Ashino, Natalia M.; Morgado, Daniella L.; Frollini, Elisabeth; Paganin, Valdecir A.; Gonzalez, Ernesto Rafael [Universidade de Sao Paulo (IQSC/USP), Sao Carlos, SP (Brazil); Bajo, Justo Lobato [University of Castilla-La Mancha, Ciudad Real (Spain). Dept. of Chemical Engineering

2010-07-01

This work presents an interesting approach in order to enhance the performance of Polymer Electrolyte Membrane Fuel Cells (PEMFC) by means of an increase in the operational temperature. For this, two polymeric materials, Poly(2,5-bibenzimidazole) (ABPBI) and Poly[2,2'-(m-phenyl en)-5,5' bib enzimidazol] (PBI), impregnated with phosphoric acid have been utilized. These have shown excellent properties, such as thermal stability above 500 deg C, reasonably high conductivity when impregnated with H{sub 3}PO{sub 4} and a low permeability to alcohols compared to Nafion. Preliminary fuel cells measurements on hydrogen based Polymer Electrolyte Membrane Fuel Cell (PEMFC) displayed an interestingly reasonable good fuel cell performance, a quite reduced loss when the hydrogen stream was polluted with carbon monoxide, and finally, when the system was tested with an ethanol/water (E/W) fuel, it displayed quite promising results that allows placing this system as an attractive option in order to increase the cell performance and deal with the typical limitations of low temperature Nafion-based PEMFC. (author)

Purification, crystallization and preliminary X-ray analysis of the IgV domain of human nectin-4

International Nuclear Information System (INIS)

Xu, Xiang; Zhang, Xiaoai; Lu, Guangwen; Cai, Yongping

2012-01-01

Nectin-4 belongs to a family of immunoglobulin-like cell adhesion molecules and is highly expressed in cancer cells. Recently, nectin-4 was found to be a receptor of measles virus and the IgV domain sustains strong binding to measles virus H protein. In this study, the successful expression and purification of human nectin-4 V domain (nectin-4v) is reported Nectin-4 belongs to a family of immunoglobulin-like cell adhesion molecules and is highly expressed in cancer cells. Recently, nectin-4 was found to be a receptor of measles virus and the IgV domain sustains strong binding to measles virus H protein. In this study, the successful expression and purification of human nectin-4 V domain (nectin-4v) is reported. The purified protein was crystallized using the sitting-drop vapour-diffusion method. The crystals diffracted to 1.8 Å resolution and belonged to space group P2 1 , with unit-cell parameters a = 33.1, b = 51.7, c = 56.9 Å, β = 94.7°. Preliminary analysis of the diffraction data was also performed

Hybrid Direct Carbon Fuel Cell Performance with Anode Current Collector Material

DEFF Research Database (Denmark)

Deleebeeck, Lisa; Kammer Hansen, Kent

2015-01-01

collectors were studied: Au, Ni, Ag, and Pt. It was shown that the performance of the direct carbon fuel cell (DCFC) is dependent on the current collector materials, Ni and Pt giving the best performance, due to their catalytic activity. Gold is suggested to be the best material as an inert current collector......The influence of the current collector on the performance of a hybrid direct carbon fuel cell (HDCFC), consisting of solid oxide fuel cell (SOFC) with a molten carbonate-carbon slurry in contact with the anode, has been investigated using current-voltage curves. Four different anode current...

A hand-held imaging probe for radio-guided surgery: physical performance and preliminary clinical experience

International Nuclear Information System (INIS)

Pitre, S.; Menard, L.; Charon, Y.; Solal, M.; Garbay, J.R.

2003-01-01

Improvements in the specificity of radiopharmaceutical compounds have been paralleled by an upsurge of interest in developing small detectors to assist surgeons in localizing tumour tissue during surgery. This study reports the main technical features and physical characteristics of a new hand-held gamma camera dedicated to accurate and real-time intra-operative imaging. First clinical experience is also reported. The POCI (Per-operative Compact Imager) camera consists of a head module composed of a high-resolution interchangeable lead collimator and a CsI(Na) crystal plate optically coupled to an intensified position-sensitive diode. The current prototype has a 40-mm diameter field of view, an outer diameter of 9.5 cm, a length of 9 cm and a weight of 1.2 kg. Overall detector imaging characteristics were evaluated by technetium-99m phantom measurements. Three patients with breast cancer previously scheduled to undergo sentinel lymph node detection were selected for the preliminary clinical experience. Preoperative images of the lymphatic basin obtained using the POCI camera were compared with conventional transcutaneous explorations using a non-imaging gamma probe. The full-width at half-maximum (FWHM) spatial resolution was investigated in both air and scattering medium; when the phantom was placed in contact with the collimator, the POCI camera exhibited a 3.2 mm FWHM. The corresponding sensitivity was 290 cps/MBq. The preliminary clinical results showed that POCI was able to predict the number and location of all SLNs. In one case, two deep radioactive nodes missed by the gamma probe were detected on the intra-operative images. This very initial experience demonstrates that the physical performance of the POCI camera is adequate for radio-guided surgery. These results are sufficiently encouraging to prompt further evaluation studies designed to determine the specific and optimal clinical role of intra-operative imaging devices

Performance analysis of solar cell arrays in concentrating light intensity

International Nuclear Information System (INIS)

Xu Yongfeng; Li Ming; Lin Wenxian; Wang Liuling; Xiang Ming; Zhang Xinghua; Wang Yunfeng; Wei Shengxian

2009-01-01

Performance of concentrating photovoltaic/thermal system is researched by experiment and simulation calculation. The results show that the I-V curve of the GaAs cell array is better than that of crystal silicon solar cell arrays and the exergy produced by 9.51% electrical efficiency of the GaAs solar cell array can reach 68.93% of the photovoltaic/thermal system. So improving the efficiency of solar cell arrays can introduce more exergy and the system value can be upgraded. At the same time, affecting factors of solar cell arrays such as series resistance, temperature and solar irradiance also have been analyzed. The output performance of a solar cell array with lower series resistance is better and the working temperature has a negative impact on the voltage in concentrating light intensity. The output power has a -20 W/V coefficient and so cooling fluid must be used. Both heat energy and electrical power are then obtained with a solar trough concentrating photovoltaic/thermal system. (semiconductor devices)

The Effects of Battalion Staff Stabilization on Individual and Unit Performance: A Preliminary Investigation

National Research Council Canada - National Science Library

Ardison, Sharon

2001-01-01

... (six of the seven units). Although improvements in leadership skills and abilities were associated with longer command team tenure, the results are those of a preliminary investigation and not intended for generalization to the Army-at-large.

Transcriptome analysis of Spodoptera frugiperda Sf9 cells reveals putative apoptosis-related genes and a preliminary apoptosis mechanism induced by azadirachtin.

Science.gov (United States)

Shu, Benshui; Zhang, Jingjing; Sethuraman, Veeran; Cui, Gaofeng; Yi, Xin; Zhong, Guohua

2017-10-16

As an important botanical pesticide, azadirachtin demonstrates broad insecticidal activity against many agricultural pests. The results of a previous study indicated the toxicity and apoptosis induction of azadirachtin in Spodoptera frugiperda Sf9 cells. However, the lack of genomic data has hindered a deeper investigation of apoptosis in Sf9 cells at a molecular level. In the present study, the complete transcriptome data for Sf9 cell line was accomplished using Illumina sequencing technology, and 97 putative apoptosis-related genes were identified through BLAST and KEGG orthologue annotations. Fragments of potential candidate apoptosis-related genes were cloned, and the mRNA expression patterns of ten identified genes regulated by azadirachtin were examined using qRT-PCR. Furthermore, Western blot analysis showed that six putative apoptosis-related proteins were upregulated after being treated with azadirachtin while the protein Bcl-2 were downregulated. These data suggested that both intrinsic and extrinsic apoptotic signal pathways comprising the identified potential apoptosis-related genes were potentially active in S. frugiperda. In addition, the preliminary results revealed that caspase-dependent or caspase-independent apoptotic pathways could function in azadirachtin-induced apoptosis in Sf9 cells.

NSLS-II Preliminary Design Report

International Nuclear Information System (INIS)

Dierker, S.

2007-01-01

Following the CD0 approval of the National Synchrotron Light Source II (NSLS-II) during August 2005, Brookhaven National Laboratory prepared a conceptual design for a worldclass user facility for scientific research using synchrotron radiation. DOE SC review of the preliminary baseline in December 2006 led to the subsequent CD1 approval (approval of alternative selection and cost range). This report is the documentation of the preliminary design work for the NSLS-II facility. The preliminary design of the Accelerator Systems (Part 1) was developed mostly based of the Conceptual Design Report, except for the Booster design, which was changed from in-storage-ring tunnel configuration to in external- tunnel configuration. The design of beamlines (Part 2) is based on designs developed by engineering firms in accordance with the specification provided by the Project. The conventional facility design (Part 3) is the Title 1 preliminary design by the AE firm that met the NSLS-II requirements. Last and very important, Part 4 documents the ES and H design and considerations related to this preliminary design. The NSLS-II performance goals are motivated by the recognition that major advances in many important technology problems will require scientific breakthroughs in developing new materials with advanced properties. Achieving this will require the development of new tools that will enable the characterization of the atomic and electronic structure, chemical composition, and magnetic properties of materials, at nanoscale resolution. These tools must be nondestructive, to image and characterize buried structures and interfaces, and they must operate in a wide range of temperatures and harsh environments. The NSLS-II facility will provide ultra high brightness and flux and exceptional beam stability. It will also provide advanced insertion devices, optics, detectors, and robotics, and a suite of scientific instruments designed to maximize the scientific output of the

NSLS-II Preliminary Design Report

Energy Technology Data Exchange (ETDEWEB)

Dierker, S.

2007-11-01

Following the CD0 approval of the National Synchrotron Light Source II (NSLS-II) during August 2005, Brookhaven National Laboratory prepared a conceptual design for a worldclass user facility for scientific research using synchrotron radiation. DOE SC review of the preliminary baseline in December 2006 led to the subsequent CD1 approval (approval of alternative selection and cost range). This report is the documentation of the preliminary design work for the NSLS-II facility. The preliminary design of the Accelerator Systems (Part 1) was developed mostly based of the Conceptual Design Report, except for the Booster design, which was changed from in-storage-ring tunnel configuration to in external- tunnel configuration. The design of beamlines (Part 2) is based on designs developed by engineering firms in accordance with the specification provided by the Project. The conventional facility design (Part 3) is the Title 1 preliminary design by the AE firm that met the NSLS-II requirements. Last and very important, Part 4 documents the ES&H design and considerations related to this preliminary design. The NSLS-II performance goals are motivated by the recognition that major advances in many important technology problems will require scientific breakthroughs in developing new materials with advanced properties. Achieving this will require the development of new tools that will enable the characterization of the atomic and electronic structure, chemical composition, and magnetic properties of materials, at nanoscale resolution. These tools must be nondestructive, to image and characterize buried structures and interfaces, and they must operate in a wide range of temperatures and harsh environments. The NSLS-II facility will provide ultra high brightness and flux and exceptional beam stability. It will also provide advanced insertion devices, optics, detectors, and robotics, and a suite of scientific instruments designed to maximize the scientific output of the facility

The effect of liner hydraulic conductivity on disposal cell performance

International Nuclear Information System (INIS)

Yu, C.; Yuan, Y.C.; Chia, Y.P.

1988-01-01

Multilayered disposal cells are frequently used for the disposal of radioactive and hazardous wastes. These disposal cells consist of materials with different permeabilities that are placed in various thicknesses at the bottom as well as in the cover of the cell. Typically, a layer of permeable material is placed above a layer with low permeability; the permeable layer functions as a drainage/leachate collection system and the low-permeability layer functions as a migration barrier/liner. This paper analyzes the effects of infiltration through unsaturated soil liners on the long-term performance of the disposal cell. Based on the results of this study, it is concluded that the long-term performance of a disposal cell is dependent on a well-designed cell cover. The design should emphasize a cap with less permeable material to prevent water from infiltrating the disposal cell. An impermeable bottom liner is effective only in the short term; however, it can eventually result in saturation of the wastes and cause the bathtub effect over the long term

Effects of ambient conditions on fuel cell vehicle performance

Science.gov (United States)

Haraldsson, K.; Alvfors, P.

Ambient conditions have considerable impact on the performance of fuel cell hybrid vehicles. Here, the vehicle fuel consumption, the air compressor power demand, the water management system and the heat loads of a fuel cell hybrid sport utility vehicle (SUV) were studied. The simulation results show that the vehicle fuel consumption increases with 10% when the altitude increases from 0 m up to 3000 m to 4.1 L gasoline equivalents/100 km over the New European Drive Cycle (NEDC). The increase is 19% on the more power demanding highway US06 cycle. The air compressor is the major contributor to this fuel consumption increase. Its load-following strategy makes its power demand increase with increasing altitude. Almost 40% of the net power output of the fuel cell system is consumed by the air compressor at the altitude of 3000 m with this load-following strategy and is thus more apparent in the high-power US06 cycle. Changes in ambient air temperature and relative humidity effect on the fuel cell system performance in terms of the water management rather in vehicle fuel consumption. Ambient air temperature and relative humidity have some impact on the vehicle performance mostly seen in the heat and water management of the fuel cell system. While the heat loads of the fuel cell system components vary significantly with increasing ambient temperature, the relative humidity did not have a great impact on the water balance. Overall, dimensioning the compressor and other system components to meet the fuel cell system requirements at the minimum and maximum expected ambient temperatures, in this case 5 and 40 °C, and high altitude, while simultaneously choosing a correct control strategy are important parameters for efficient vehicle power train management.

Hydrothermal Liquefaction Treatment Preliminary Hazard Analysis Report

Energy Technology Data Exchange (ETDEWEB)

Lowry, Peter P.; Wagner, Katie A.

2015-08-31

A preliminary hazard assessment was completed during February 2015 to evaluate the conceptual design of the modular hydrothermal liquefaction treatment system. The hazard assessment was performed in 2 stages. An initial assessment utilizing Hazard Identification and Preliminary Hazards Analysis (PHA) techniques identified areas with significant or unique hazards (process safety-related hazards) that fall outside of the normal operating envelope of PNNL and warranted additional analysis. The subsequent assessment was based on a qualitative What-If analysis. This analysis was augmented, as necessary, by additional quantitative analysis for scenarios involving a release of hazardous material or energy with the potential for affecting the public.

Experimental study of commercial size proton exchange membrane fuel cell performance

International Nuclear Information System (INIS)

Yan, Wei-Mon; Wang, Xiao-Dong; Lee, Duu-Jong; Zhang, Xin-Xin; Guo, Yi-Fan; Su, Ay

2011-01-01

Commercial sized (16 x 16 cm 2 active surface area) proton exchange membrane (PEM) fuel cells with serpentine flow chambers are fabricated. The GORE-TEX (registered) PRIMEA 5621 was used with a 35-μm-thick PEM with an anode catalyst layer with 0.45 mg cm -2 Pt and cathode catalyst layer with 0.6 mg cm -2 Pt and Ru or GORE-TEX (registered) PRIMEA 57 was used with an 18-μm-thick PEM with an anode catalyst layer at 0.2 mg cm -2 Pt and cathode catalyst layer at 0.4 mg cm -2 of Pt and Ru. At the specified cell and humidification temperatures, the thin PRIMEA 57 membrane yields better cell performance than the thick PRIMEA 5621 membrane, since hydration of the former is more easily maintained with the limited amount of produced water. Sufficient humidification at both the cathode and anode sides is essential to achieve high cell performance with a thick membrane, like the PRIMEA 5621. The optimal cell temperature to produce the best cell performance with PRIMEA 5621 is close to the humidification temperature. For PRIMEA 57, however, optimal cell temperature exceeds the humidification temperature.

Performance of planar heterojunction perovskite solar cells under light concentration

Directory of Open Access Journals (Sweden)

Aaesha Alnuaimi

2016-11-01

Full Text Available In this work, we present 2D simulation of planar heterojunction perovskite solar cells under high concentration using physics-based TCAD. The performance of planar perovskite heterojunction solar cells is examined up to 1000 suns. We analyze the effect of HTM mobility and band structure, surface recombination velocities at interfaces and the effect of series resistance under concentrated light. The simulation results revealed that the low mobility of HTM material limits the improvement in power conversation efficiency of perovskite solar cells under concentration. In addition, large band offset at perovskite/HTM interface contributes to the high series resistance. Moreover, losses due to high surface recombination at interfaces and the high series resistance deteriorate significantly the performance of perovskite solar cells under concentration.

Performance of a Fuel-Cell-Powered, Small Electric Airplane Assessed

Science.gov (United States)

Berton, Jeffrey J.

2004-01-01

Rapidly emerging fuel-cell-power technologies may be used to launch a new revolution of electric propulsion systems for light aircraft. Future small electric airplanes using fuel cell technologies hold the promise of high reliability, low maintenance, low noise, and - with the exception of water vapor - zero emissions. An analytical feasibility and performance assessment was conducted by NASA Glenn Research Center's Airbreathing Systems Analysis Office of a fuel-cell-powered, propeller-driven, small electric airplane based on a model of the MCR-01 two-place kitplane (Dyn'Aero, Darois, France). This assessment was conducted in parallel with an ongoing effort by the Advanced Technology Products Corporation and the Foundation for Advancing Science and Technology Education. Their project - partially funded by a NASA grant - is to design, build, and fly the first manned, continuously propelled, nongliding electric airplane. In our study, an analytical performance model of a proton exchange membrane (PEM) fuel cell propulsion system was developed and applied to a notional, two-place light airplane modeled after the MCR-01 kitplane. The PEM fuel cell stack was fed pure hydrogen fuel and humidified ambient air via a small automotive centrifugal supercharger. The fuel cell performance models were based on chemical reaction analyses calibrated with published data from the fledgling U.S. automotive fuel cell industry. Electric propeller motors, rated at two shaft power levels in separate assessments, were used to directly drive a two-bladed, variable-pitch propeller. Fuel sources considered were compressed hydrogen gas and cryogenic liquid hydrogen. Both of these fuel sources provided pure, contaminant-free hydrogen for the PEM cells.

Antares: preliminary demonstrator results

International Nuclear Information System (INIS)

Kouchner, A.

2000-05-01

The ANTARES collaboration is building an undersea neutrino telescope off Toulon (Mediterranean sea) with effective area ∼ 0.1 km 2 . An extensive study of the site properties has been achieved together with software analysis in order to optimize the performance of the detector. Results are summarized here. An instrumented line, linked to shore for first time via an electro-optical cable, has been immersed late 1999. The preliminary results of this demonstrator line are reported. (author)

Preliminary investigation of stereotactic body radiation therapy for medically inoperable stage I/II non-small cell lung cancer

International Nuclear Information System (INIS)

Guo Jindong; Lu Changxing; Wang Jiaming; Liu Jun; Li Hongxuan; Wang Changlu; Gao Lanting; Zhao Lei

2011-01-01

Objective: To evaluate the therapeutic efficacy and treatment-related toxicity of stereotactic body radiation therapy (SBRT) in patients with medically inoperable stage I/II non-small cell lung cancer (NSCLC). Methods: SBRT was applied to 30 patients, including clinically staged T 1 , T 2 (≤5 cm) or T 3 (chest wall primary tumors only), N 0 , M 0 ,biopsy-confirmed NSCLC. All patients were precluded from lobotomy because of physical condition or comorbidity. No patients developed tumors of any T-stage in the proximal zone. SBRT was performed with the total dose of 50 Gy to 70 Gy in 10 - 11 fractions during 12 - 15 days. prescription line was set onthe edge of the PTV. Results: The follow-up rate was 100%. The number of patients who completed the 1-, and 2-year follow-up were 15, and 10, respectively. All 30 patients completed therapy as planned. The complete response (CR), partial response (PR) and stable disease (SD) rates were 37%, 53% and 3%, respectively. With a median follow-up of 16 months (range, 4-36 months), Kaplan-Meier local control at 2 years was 94%. The 2-year overall survival was 84% and the 2-year cancer specific survival was 90%. Seven patients(23%) developed Grade 2 pneumonitis, no grade > 2 acute or late lung toxicity was observed. No one developed chest wall pain. Conclusions: It is feasible to deliver 50 Gy to 70 Gy of SBRT in 10 - 11 fractions for medically inoperable patients with stage I / II NSCLC. It was associated with low incidence of toxicities and provided sustained local tumor control.The preliminary investigation indicated the cancer specific survival probability of SBRT was high. It is necessary to perform similar investigation in a larger number of patients with long-term follow-up. (authors)

Development of a moderate rate lithium/thionyl-chloride D cell

Science.gov (United States)

Cieslak, Wendy R.; Street, Henry K.

1990-05-01

We have designed a lithium/thionyl chloride D cell for efficient performance at the moderate rate of approximately 500 mA (6.25 omega load). The SNL-MR-D cell has 345 sq cm of active electrode area, 1.0 M LiAlCl4 electrolyte that may have SO2 additive, and a cathode blended of Shawinigan Acetylene Black, Cabot Black Pearls 2000, and Teflon binder. The average performance of cells built in-house and discharged at 25 C and 6.25 omega has been 14.9 Ah (50 Wh). We have aged the cells at 30 C and 50 C, and measured complex impedance and microcalorimetry during the aging period. The cells have been discharged after the aging period at 25 C and 0 C. This preliminary study has allowed us to establish an initial cell design and estimate the rate of capacity loss on storage or long-term usage.

Preliminary Hazards Analysis Plasma Hearth Process

International Nuclear Information System (INIS)

Aycock, M.; Coordes, D.; Russell, J.; TenBrook, W.; Yimbo, P.

1993-11-01

This Preliminary Hazards Analysis (PHA) for the Plasma Hearth Process (PHP) follows the requirements of United States Department of Energy (DOE) Order 5480.23 (DOE, 1992a), DOE Order 5480.21 (DOE, 1991d), DOE Order 5480.22 (DOE, 1992c), DOE Order 5481.1B (DOE, 1986), and the guidance provided in DOE Standards DOE-STD-1027-92 (DOE, 1992b). Consideration is given to ft proposed regulations published as 10 CFR 830 (DOE, 1993) and DOE Safety Guide SG 830.110 (DOE, 1992b). The purpose of performing a PRA is to establish an initial hazard categorization for a DOE nuclear facility and to identify those processes and structures which may have an impact on or be important to safety. The PHA is typically performed during and provides input to project conceptual design. The PRA then is followed by a Preliminary Safety Analysis Report (PSAR) performed during Title I and II design. This PSAR then leads to performance of the Final Safety Analysis Report performed during construction, testing, and acceptance and completed before routine operation. Radiological assessments indicate that a PHP facility, depending on the radioactive material inventory, may be an exempt, Category 3, or Category 2 facility. The calculated impacts would result in no significant impact to offsite personnel or the environment. Hazardous material assessments indicate that a PHP facility will be a Low Hazard facility having no significant impacts either onsite or offsite to personnel and the environment

Enhancing the performance of photovoltaic cells by using down-converting KCaGd(PO4)2∶Eu3+ phosphors

Institute of Scientific and Technical Information of China (English)

Yen-Chi Chen; Woan-Yu Huang; Teng-Ming Chen

2011-01-01

The goal of this work is aimed to improve the power conversion efficiency of single crystalline silicon-based photovoltaic (PV) cells by using the solar spectral conversion principle,which employed a down-converting phosphor to convert a high-energy ultraviolet photon to the less energetic red-emitting photons to improve the spectral response of Si solar cells.In this study,the surface of silicon solar cells was coated with a red-emitting KCaGd(PO4)2∶Eu3+ phosphor by using the screen-printing technique.In addition to the investigation on the microstructure using scanning electron microscopy (SEM),we measured the short circuit current (Isc),open circuit voltage (Voc),and power conversion efficiency (η) of spectral-conversion cells and compared with those of bare solar cells as a reference.Preliminary experimental results revealed that in an optimized PV cell,an enhancement of (0.64+0.01)％ (from 16.03％ to 16.67％) in △η ofa Si-based PV cell was achieved.

Preliminary biogeochemical assessment of EPICA LGM and Holocene ice samples

Science.gov (United States)

Bulat, S.; Alekhina, I.; Marie, D.; Wagenbach, D.; Raynaud, D.; Petit, J. R.

2009-04-01

We are investigating the biological content (biomass and microbial diversity of Aeolian origin) of EPICA ice core within the frame of EPICA Microbiology consortium*. Two ice core sections were selected from EPICA Dome C and Droning Maud Land, both from LGM and Holocene. Preliminary measurements of DOC (dissolved organic content) and microbial cell concentrations have been performed. Both analyses showed the very low biomass and ultra low DOC content. Trace DNA analyses are in a progress. The ice sections were decontaminated in LGGE cold and clean room facilities benefiting the protocol developed for Vostok ice core studies. The melt water was then shared between two party laboratories for a complementary approach in studying microbial content. Prior to biology the melt water was tested for chemical contaminant ions and organic acids, DOC and dust contents. The biological methods included all the spectra of appropriate molecular techniques (gDNA extraction, PCR, clone libraries and sequencing). As preliminary results, both LGM (well identified by dust fallout) and Holocene ice samples (EDC99 and EDML) proved to be extremely clear (i.e. pristine) in terms of biomass (less then 4 cells per ml) and DOC contents (less then 5 ppbC). There was no obvious difference between LGM and Holocene in cell counts, while LGM showed a bit high organic carbon content. The latter in terms of biology means ultra-oligotrophic conditions (i.e., no possibility for heterotrophic life style). In fact no metabolizing microbial cells or propagating populations are expected at these depths at temperature -38oC and lower (limiting life temperature threshold is -20°C). Nevertheless some life seeds brought in Antarctica with precipitation could be well preserved because the age is rather young (21 kyr and less). Trying to identify these aliens and document their distribution during last climate cycle the meltwater was concentrated about 1000 times down. The genomic DNA was extracted and very

Theoretical performance of hydrogen-bromine rechargeable SPE fuel cell. [Solid Polymer Electrolyte

Science.gov (United States)

Savinell, R. F.; Fritts, S. D.

1988-01-01

A mathematical model was formulated to describe the performance of a hydrogen-bromine fuel cell. Porous electrode theory was applied to the carbon felt flow-by electrode and was coupled to theory describing the solid polymer electrolyte (SPE) system. Parametric studies using the numerical solution to this model were performed to determine the effect of kinetic, mass transfer, and design parameters on the performance of the fuel cell. The results indicate that the cell performance is most sensitive to the transport properties of the SPE membrane. The model was also shown to be a useful tool for scale-up studies.

Exponential Decay Nonlinear Regression Analysis of Patient Survival Curves: Preliminary Assessment in Non-Small Cell Lung Cancer

Science.gov (United States)

Stewart, David J.; Behrens, Carmen; Roth, Jack; Wistuba, Ignacio I.

2010-01-01

Background For processes that follow first order kinetics, exponential decay nonlinear regression analysis (EDNRA) may delineate curve characteristics and suggest processes affecting curve shape. We conducted a preliminary feasibility assessment of EDNRA of patient survival curves. Methods EDNRA was performed on Kaplan-Meier overall survival (OS) and time-to-relapse (TTR) curves for 323 patients with resected NSCLC and on OS and progression-free survival (PFS) curves from selected publications. Results and Conclusions In our resected patients, TTR curves were triphasic with a “cured” fraction of 60.7% (half-life [t1/2] >100,000 months), a rapidly-relapsing group (7.4%, t1/2=5.9 months) and a slowly-relapsing group (31.9%, t1/2=23.6 months). OS was uniphasic (t1/2=74.3 months), suggesting an impact of co-morbidities; hence, tumor molecular characteristics would more likely predict TTR than OS. Of 172 published curves analyzed, 72 (42%) were uniphasic, 92 (53%) were biphasic, 8 (5%) were triphasic. With first-line chemotherapy in advanced NSCLC, 87.5% of curves from 2-3 drug regimens were uniphasic vs only 20% of those with best supportive care or 1 drug (p<0.001). 54% of curves from 2-3 drug regimens had convex rapid-decay phases vs 0% with fewer agents (p<0.001). Curve convexities suggest that discontinuing chemotherapy after 3-6 cycles “synchronizes” patient progression and death. With postoperative adjuvant chemotherapy, the PFS rapid-decay phase accounted for a smaller proportion of the population than in controls (p=0.02) with no significant difference in rapid-decay t1/2, suggesting adjuvant chemotherapy may move a subpopulation of patients with sensitive tumors from the relapsing group to the cured group, with minimal impact on time to relapse for a larger group of patients with resistant tumors. In untreated patients, the proportion of patients in the rapid-decay phase increased (p=0.04) while rapid-decay t1/2 decreased (p=0.0004) with increasing

Preliminary Transcriptome Analysis of Mature Biofilm and Planktonic Cells of Salmonella Enteritidis Exposure to Acid Stress

Directory of Open Access Journals (Sweden)

Kun Jia

2017-09-01

Full Text Available Salmonella has emerged as a well-recognized food-borne pathogen, with many strains able to form biofilms and thus cause cross-contamination in food processing environments where acid-based disinfectants are widely encountered. In the present study, RNA sequencing was employed to establish complete transcriptome profiles of Salmonella Enteritidis in the forms of planktonic and biofilm-associated cells cultured in Tryptic Soytone Broth (TSB and acidic TSB (aTSB. The gene expression patterns of S. Enteritidis significantly differed between biofilm-associated and planktonic cells cultivated under the same conditions. The assembled transcriptome of S. Enteritidis in this study contained 5,442 assembled transcripts, including 3,877 differentially expressed genes (DEGs identified in biofilm and planktonic cells. These DEGs were enriched in terms such as regulation of biological process, metabolic process, macromolecular complex, binding and transferase activity, which may play crucial roles in the biofilm formation of S. Enteritidis cultivated in aTSB. Three significant pathways were observed to be enriched under acidic conditions: bacterial chemotaxis, porphyrin-chlorophyll metabolism and sulfur metabolism. In addition, 15 differentially expressed novel non-coding small RNAs (sRNAs were identified, and only one was found to be up-regulated in mature biofilms. This preliminary study of the S. Enteritidis transcriptome serves as a basis for future investigations examining the complex network systems that regulate Salmonella biofilm in acidic environments, which provide information on biofilm formation and acid stress interaction that may facilitate the development of novel disinfection procedures in the food processing industry.

Effects of dissolved iron and chromium on the performance of direct methanol fuel cell

International Nuclear Information System (INIS)

Chen, Weimin; Xin, Qin; Sun, Gongquan; Yang, Shaohua; Zhou, Zhenhua; Mao, Qing; Sun, Pichang

2007-01-01

Effects of Fe 3+ and Cr 3+ ions on the performance of direct methanol fuel cell were investigated. The results show that the cell performance decreased remarkably when the concentration of Fe 3+ or Cr 3+ exceeded 1 x 10 -4 mol L -1 . Fe 3+ displayed a strong negative effect on the catalytic oxidation of methanol, while Cr 3+ affected the cell performance primarily by exchanging with protons of the membrane/ionomer and resulted in ionic conductivity losses. Complete recovery of the cell performance was not obtained after flushing the cell with deionized water

Performance improvement of silicon solar cells by nanoporous silicon coating

Directory of Open Access Journals (Sweden)

Dzhafarov T. D.

2012-04-01

Full Text Available In the present paper the method is shown to improve the photovoltaic parameters of screen-printed silicon solar cells by nanoporous silicon film formation on the frontal surface of the cell using the electrochemical etching. The possible mechanisms responsible for observed improvement of silicon solar cell performance are discussed.

Preliminary hazards analysis -- vitrification process

International Nuclear Information System (INIS)

Coordes, D.; Ruggieri, M.; Russell, J.; TenBrook, W.; Yimbo, P.

1994-06-01

This paper presents a Preliminary Hazards Analysis (PHA) for mixed waste vitrification by joule heating. The purpose of performing a PHA is to establish an initial hazard categorization for a DOE nuclear facility and to identify those processes and structures which may have an impact on or be important to safety. The PHA is typically performed during and provides input to project conceptual design. The PHA is then followed by a Preliminary Safety Analysis Report (PSAR) performed during Title 1 and 2 design. The PSAR then leads to performance of the Final Safety Analysis Report performed during the facility's construction and testing. It should be completed before routine operation of the facility commences. This PHA addresses the first four chapters of the safety analysis process, in accordance with the requirements of DOE Safety Guidelines in SG 830.110. The hazards associated with vitrification processes are evaluated using standard safety analysis methods which include: identification of credible potential hazardous energy sources; identification of preventative features of the facility or system; identification of mitigative features; and analyses of credible hazards. Maximal facility inventories of radioactive and hazardous materials are postulated to evaluate worst case accident consequences. These inventories were based on DOE-STD-1027-92 guidance and the surrogate waste streams defined by Mayberry, et al. Radiological assessments indicate that a facility, depending on the radioactive material inventory, may be an exempt, Category 3, or Category 2 facility. The calculated impacts would result in no significant impact to offsite personnel or the environment. Hazardous materials assessment indicates that a Mixed Waste Vitrification facility will be a Low Hazard facility having minimal impacts to offsite personnel and the environment

Preliminary hazards analysis -- vitrification process

Energy Technology Data Exchange (ETDEWEB)

Coordes, D.; Ruggieri, M.; Russell, J.; TenBrook, W.; Yimbo, P. [Science Applications International Corp., Pleasanton, CA (United States)

1994-06-01

This paper presents a Preliminary Hazards Analysis (PHA) for mixed waste vitrification by joule heating. The purpose of performing a PHA is to establish an initial hazard categorization for a DOE nuclear facility and to identify those processes and structures which may have an impact on or be important to safety. The PHA is typically performed during and provides input to project conceptual design. The PHA is then followed by a Preliminary Safety Analysis Report (PSAR) performed during Title 1 and 2 design. The PSAR then leads to performance of the Final Safety Analysis Report performed during the facility`s construction and testing. It should be completed before routine operation of the facility commences. This PHA addresses the first four chapters of the safety analysis process, in accordance with the requirements of DOE Safety Guidelines in SG 830.110. The hazards associated with vitrification processes are evaluated using standard safety analysis methods which include: identification of credible potential hazardous energy sources; identification of preventative features of the facility or system; identification of mitigative features; and analyses of credible hazards. Maximal facility inventories of radioactive and hazardous materials are postulated to evaluate worst case accident consequences. These inventories were based on DOE-STD-1027-92 guidance and the surrogate waste streams defined by Mayberry, et al. Radiological assessments indicate that a facility, depending on the radioactive material inventory, may be an exempt, Category 3, or Category 2 facility. The calculated impacts would result in no significant impact to offsite personnel or the environment. Hazardous materials assessment indicates that a Mixed Waste Vitrification facility will be a Low Hazard facility having minimal impacts to offsite personnel and the environment.

French 900 MWe PWR PSA preliminary results

International Nuclear Information System (INIS)

Lanore, J.M.; Brisbois, J.

1988-10-01

A PSA is performed by the Safety Assessment Department of CEA for a 900 MWe standardized plant. The paper presents the objectives, the scope of the study and the relative preliminary results. Some general insights are drawn, especially the benefit related to the implementation of emergency procedures

Effects of impurities on silicon solar-cell performance

Science.gov (United States)

Hopkins, R. H.

1986-01-01

Model analyses indicate that sophisticated solar cell designs (back surface fields, optical reflectors, surface passivation, and double layer antireflective coatings) can produce devices with conversion efficiencies above 20%. To realize this potential, the quality of the silicon from which the cells are made must be improved; and these excellent electrical properties must be maintained during device processing. As the cell efficiency rises, the sensitivity to trace contaminants also increases. For example, the threshold Ti impurity concentraion at which cell performance degrades is more than an order of magnitude lower for an 18% cell than for a 16% cell. Similar behavior occurs for numerous other metal species which introduce deep level traps that stimulate the recombination of photogenerated carriers in silicon. Purification via crystal growth in conjunction with gettering steps to preserve the large diffusion length of the as grown material can lead to the production of devices with efficiencies above 18%, as verified experimentally.

Preliminary experimental evaluation of a four wheel motors, batteries plus ultracapacitors and series hybrid powertrain

Energy Technology Data Exchange (ETDEWEB)

Rambaldi, Lorenzo [Interuniversity Research Center on Sustainable Development, Sapienza University of Rome, Rome (Italy); Bocci, Enrico [Department of Mechanics and Aeronautics, Sapienza University of Rome, Rome (Italy); Orecchini, Fabio [Guglielmo Marconi University, Rome (Italy)

2011-02-15

This paper reports the preliminary experimental evaluation of a four wheel motors series hybrid prototype equipped with an internal combustion engine coupled to a generator and an energy recovery system (batteries plus ultracapacitors). The paper analyses global efficiency (energy dissipated to overcome the dissipative forces on energy dissipated in fuel), autonomy in electric configuration, and the efficiency of the regenerative braking system. The tests were carried out in a test cell equipped with a chassis dynamometer. The tests were performed according to the current regulated procedures. A constant speed test was performed in order to evaluate the autonomy of the vehicle in the electric configuration. The results show that the real tank to wheels efficiency is about 30% for HOST as a series hybrid and 79% for HOST as an electric vehicle. (author)

Preliminary In Vivo Experiments on Adhesion of Geckos

OpenAIRE

Lepore, E.; Brianza, S.; Antoniolli, F.; Buono, M.; Carpinteri, A.; Pugno, N.

2008-01-01

We performed preliminary experiments on the adhesion of a Tokay gecko on surfaces with different roughness, with or without particles with significant different granulometry, before/after or during the moult. The results were analyzed using the Weibull statistics.

Preliminary model and validation of molten carbonate fuel cell kinetics under sulphur poisoning

Science.gov (United States)

Audasso, E.; Nam, S.; Arato, E.; Bosio, B.

2017-06-01

MCFC represents an effective technology to deal with CO2 capture and relative applications. If used for these purposes, due to the working conditions and the possible feeding, MCFC must cope with a different number of poisoning gases such as sulphur compounds. In literature, different works deal with the development of kinetic models to describe MCFC performance to help both industrial applications and laboratory simulations. However, in literature attempts to realize a proper model able to consider the effects of poisoning compounds are scarce. The first aim of the present work is to provide a semi-empirical kinetic formulation capable to take into account the effects that sulphur compounds (in particular SO2) have on the MCFC performance. The second aim is to provide a practical example of how to effectively include the poisoning effects in kinetic models to simulate fuel cells performances. To test the reliability of the proposed approach, the obtained formulation is implemented in the kinetic core of the SIMFC (SIMulation of Fuel Cells) code, an MCFC 3D model realized by the Process Engineering Research Team (PERT) of the University of Genova. Validation is performed through data collected at the Korea Institute of Science and Technology in Seoul.

Performance adaptive training control strategy for recovering wrist movements in stroke patients: a preliminary, feasibility study

Directory of Open Access Journals (Sweden)

Sandini Giulio

2009-12-01

Full Text Available Abstract Background In the last two decades robot training in neuromotor rehabilitation was mainly focused on shoulder-elbow movements. Few devices were designed and clinically tested for training coordinated movements of the wrist, which are crucial for achieving even the basic level of motor competence that is necessary for carrying out ADLs (activities of daily life. Moreover, most systems of robot therapy use point-to-point reaching movements which tend to emphasize the pathological tendency of stroke patients to break down goal-directed movements into a number of jerky sub-movements. For this reason we designed a wrist robot with a range of motion comparable to that of normal subjects and implemented a self-adapting training protocol for tracking smoothly moving targets in order to facilitate the emergence of smoothness in the motor control patterns and maximize the recovery of the normal RoM (range of motion of the different DoFs (degrees of Freedom. Methods The IIT-wrist robot is a 3 DoFs light exoskeleton device, with direct-drive of each DoF and a human-like range of motion for Flexion/Extension (FE, Abduction/Adduction (AA and Pronation/Supination (PS. Subjects were asked to track a variable-frequency oscillating target using only one wrist DoF at time, in such a way to carry out a progressive splinting therapy. The RoM of each DoF was angularly scanned in a staircase-like fashion, from the "easier" to the "more difficult" angular position. An Adaptive Controller evaluated online performance parameters and modulated both the assistance and the difficulty of the task in order to facilitate smoother and more precise motor command patterns. Results Three stroke subjects volunteered to participate in a preliminary test session aimed at verify the acceptability of the device and the feasibility of the designed protocol. All of them were able to perform the required task. The wrist active RoM of motion was evaluated for each patient at the

Full-Duplex MIMO Small-Cell Networks: Performance Analysis

OpenAIRE

Atzeni, Italo; Kountouris, Marios

2015-01-01

Full-duplex small-cell relays with multiple antennas constitute a core element of the envisioned 5G network architecture. In this paper, we use stochastic geometry to analyze the performance of wireless networks with full-duplex multiple-antenna small cells, with particular emphasis on the probability of successful transmission. To achieve this goal, we additionally characterize the distribution of the self-interference power of the full-duplex nodes. The proposed framework reveals useful ins...

Methodology for the preliminary design of high performance schools in hot and humid climates

Science.gov (United States)

Im, Piljae

A methodology to develop an easy-to-use toolkit for the preliminary design of high performance schools in hot and humid climates was presented. The toolkit proposed in this research will allow decision makers without simulation knowledge easily to evaluate accurately energy efficient measures for K-5 schools, which would contribute to the accelerated dissemination of energy efficient design. For the development of the toolkit, first, a survey was performed to identify high performance measures available today being implemented in new K-5 school buildings. Then an existing case-study school building in a hot and humid climate was selected and analyzed to understand the energy use pattern in a school building and to be used in developing a calibrated simulation. Based on the information from the previous step, an as-built and calibrated simulation was then developed. To accomplish this, five calibration steps were performed to match the simulation results with the measured energy use. The five steps include: (1) Using an actual 2006 weather file with measured solar radiation, (2) Modifying lighting & equipment schedule using ASHRAE's RP-1093 methods, (3) Using actual equipment performance curves (i.e., scroll chiller), (4) Using the Winkelmann's method for the underground floor heat transfer, and (5) Modifying the HVAC and room setpoint temperature based on the measured field data. Next, the calibrated simulation of the case-study K-5 school was compared to an ASHRAE Standard 90.1-1999 code-compliant school. In the next step, the energy savings potentials from the application of several high performance measures to an equivalent ASHRAE Standard 90.1-1999 code-compliant school. The high performance measures applied included the recommendations from the ASHRAE Advanced Energy Design Guides (AEDG) for K-12 and other high performance measures from the literature review as well as a daylighting strategy and solar PV and thermal systems. The results show that the net

Performance of an electrochemical solar cell with molybdenite anode

International Nuclear Information System (INIS)

Lima, G.F.; Chagas, J.W.R.; Cesar, H.L.; Juliao, J.F.

1984-01-01

The performance of photoeletrochemical cells for solar energy conversion, using photoanodes of molybdenite and platinum cathode is reported. Conversion efficiency between 0.1 and 1% were determined. The surface condition of the photoanode and the light absorption by the electrolite were some factors responsible for the low efficiency of those cells. (C.L.B.) [pt

Preliminary In Vivo Experiments on Adhesion of Geckos

Directory of Open Access Journals (Sweden)

E. Lepore

2008-01-01

Full Text Available We performed preliminary experiments on the adhesion of a Tokay gecko on surfaces with different roughness, with or without particles with significant different granulometry, before/after or during the moult. The results were analyzed using the Weibull statistics.

Improved performance in GaInNAs solar cells by hydrogen passivation

International Nuclear Information System (INIS)

Fukuda, M.; Whiteside, V. R.; Keay, J. C.; Meleco, A.; Sellers, I. R.; Hossain, K.; Golding, T. D.; Leroux, M.; Al Khalfioui, M.

2015-01-01

The effect of UV-activated hydrogenation on the performance of GaInNAs solar cells is presented. A proof-of-principle investigation was performed on non-optimum GaInNAs cells, which allowed a clearer investigation of the role of passivation on the intrinsic nitrogen-related defects in these materials. Upon optimized hydrogenation of GaInNAs, a significant reduction in the presence of defect and impurity based luminescence is observed as compared to that of unpassivated reference material. This improvement in the optical properties is directly transferred to an improved performance in solar cell operation, with a more than two-fold improvement in the external quantum efficiency and short circuit current density upon hydrogenation. Temperature dependent photovoltaic measurements indicate a strong contribution of carrier localization and detrapping processes, with non-radiative processes dominating in the reference materials, and evidence for additional strong radiative losses in the hydrogenated solar cells

Glucose-based Biofuel Cells: Nanotechnology as a Vital Science in Biofuel Cells Performance

OpenAIRE

Hamideh Aghahosseini; Ali Ramazani; Pegah Azimzadeh Asiabi; Farideh Gouranlou; Fahimeh Hosseini; Aram Rezaei; Bong-Ki Min; Sang Woo Joo

2016-01-01

Nanotechnology has opened up new opportunities for the design of nanoscale electronic devices suitable for developing high-performance biofuel cells. Glucose-based biofuel cells as green energy sources can be a powerful tool in the service of small-scale power source technology as it provides a latent potential to supply power for various implantable medical electronic devices. By using physiologically produced glucose as a fuel, the living battery can recharge for continuous production of el...

Preliminary results for avelumab plus axitinib as first-line therapy in patients with advanced clear-cell renal-cell carcinoma (JAVELIN Renal 100): an open-label, dose-finding and dose-expansion, phase 1b trial.

Science.gov (United States)

Choueiri, Toni K; Larkin, James; Oya, Mototsugu; Thistlethwaite, Fiona; Martignoni, Marcella; Nathan, Paul; Powles, Thomas; McDermott, David; Robbins, Paul B; Chism, David D; Cho, Daniel; Atkins, Michael B; Gordon, Michael S; Gupta, Sumati; Uemura, Hirotsugu; Tomita, Yoshihiko; Compagnoni, Anna; Fowst, Camilla; di Pietro, Alessandra; Rini, Brian I

2018-04-01

The combination of an immune checkpoint inhibitor and a VEGF pathway inhibitor to treat patients with advanced renal-cell carcinoma might increase the clinical benefit of these drugs compared with their use alone. Here, we report preliminary results for the combination of avelumab, an IgG1 monoclonal antibody against the programmed cell death protein ligand PD-L1, and axitinib, a VEGF receptor inhibitor approved for second-line treatment of advanced renal-cell carcinoma, in treatment-naive patients with advanced renal-cell carcinoma. The JAVELIN Renal 100 study is an ongoing open-label, multicentre, dose-finding, and dose-expansion, phase 1b study, done in 14 centres in the USA, UK, and Japan. Eligible patients were aged 18 years or older (≥20 years in Japan) and had histologically or cytologically confirmed advanced renal-cell carcinoma with clear-cell component, life expectancy of at least 3 months, an Eastern Cooperative Oncology Group performance status of 1 or less, received no previous systemic treatment for advanced renal cell carcinoma, and had a resected primary tumour. Patients enrolled into the dose-finding phase received 5 mg axitinib orally twice daily for 7 days, followed by combination therapy with 10 mg/kg avelumab intravenously every 2 weeks and 5 mg axitinib orally twice daily. Based on the pharmacokinetic data from the dose-finding phase, ten additional patients were enrolled into the dose-expansion phase and assigned to this regimen. The other patients in the dose-expansion phase started taking combination therapy directly. The primary endpoint was dose-limiting toxicities in the first 4 weeks (two cycles) of treatment with avelumab plus axitinib. Safety and antitumour activity analyses were done in all patients who received at least one dose of avelumab or axitinib. This trial is registered with ClinicalTrials.gov, number NCT02493751. Between Oct 30, 2015, and Sept 30, 2016, we enrolled six patients into the dose-finding phase and 49 into the

Purification, crystallization and preliminary crystallographic analysis of the SH2 domain of IL-2-inducible T-cell kinase

International Nuclear Information System (INIS)

Joseph, Raji E.; Ginder, Nathaniel D.; Hoy, Julie A.; Nix, Jay C.; Honzatko, Richard B.; Andreotti, Amy H.

2011-01-01

Crystallization conditions are described for the cis- and trans-imide bond-containing SH2 domain of IL-2-inducible T-cell kinase. Proline is a unique amino acid owing to the relatively small energy difference between the cis and trans conformations of its peptide bond. The X–Pro imide bond readily undergoes cis–trans isomerization in the context of short peptides as well as some proteins. However, the direct detection of cis–trans proline isomerization in folded proteins is technically challenging. NMR spectroscopy is well suited to the direct detection of proline isomerization in folded proteins. It is less clear how well X-ray crystallography can reveal this conformational exchange event in folded proteins. Conformational heterogeneity owing to cis–trans proline isomerization in the Src homology 2 (SH2) domain of the IL-2-inducible T-cell kinase (ITK) has been extensively characterized by NMR. Using the ITK SH2 domain as a test system, an attempt was made to determine whether proline isomerization could be detected in a crystal structure of the ITK SH2 domain. As a first step towards this goal, the purification, crystallization and preliminary characterization of the ITK SH2 domain are described

Performance analysis of high-concentrated multi-junction solar cells in hot climate

Science.gov (United States)

Ghoneim, Adel A.; Kandil, Kandil M.; Alzanki, Talal H.; Alenezi, Mohammad R.

2018-03-01

Multi-junction concentrator solar cells are a promising technology as they can fulfill the increasing energy demand with renewable sources. Focusing sunlight upon the aperture of multi-junction photovoltaic (PV) cells can generate much greater power densities than conventional PV cells. So, concentrated PV multi-junction solar cells offer a promising way towards achieving minimum cost per kilowatt-hour. However, these cells have many aspects that must be fixed to be feasible for large-scale energy generation. In this work, a model is developed to analyze the impact of various atmospheric factors on concentrator PV performance. A single-diode equivalent circuit model is developed to examine multi-junction cells performance in hot weather conditions, considering the impacts of both temperature and concentration ratio. The impacts of spectral variations of irradiance on annual performance of various high-concentrated photovoltaic (HCPV) panels are examined, adapting spectra simulations using the SMARTS model. Also, the diode shunt resistance neglected in the existing models is considered in the present model. The present results are efficiently validated against measurements from published data to within 2% accuracy. Present predictions show that the single-diode model considering the shunt resistance gives accurate and reliable results. Also, aerosol optical depth (AOD) and air mass are most important atmospheric parameters having a significant impact on HCPV cell performance. In addition, the electrical efficiency (η) is noticed to increase with concentration to a certain concentration degree after which it decreases. Finally, based on the model predictions, let us conclude that the present model could be adapted properly to examine HCPV cells' performance over a broad range of operating conditions.

Analysis of cell performance and thermal regeneration of a lithium-tin cell having an immobilized fused-salt electrolyte

Science.gov (United States)

Cairns, E. J.; Shimotake, H.

1969-01-01

Cell performance and thermal regeneration of a thermally regenerative cell uses lithium and tin and a fused-salt electrolyte. The emf of the Li-Sn cell, as a function of cathode-alloy composition, is shown to resemble that of the Na-Bi cell.

Solid oxide fuel cell performance under severe operating conditions

DEFF Research Database (Denmark)

Koch, Søren; Hendriksen, P.V.; Mogensen, Mogens Bjerg

2006-01-01

The performance and degradation of Solid Oxide Fuel Cells (SOFC) were studied under severe operating conditions. The cells studied were manufactured in a small series by ECN, in the framework of the EU funded CORE-SOFC project. The cells were of the anode-supported type with a double layer LSM...... cathode. They were operated at 750 °C or 850 °C in hydrogen with 5% or 50% water at current densities ranging from 0.25 A cm–2 to 1 A cm–2 for periods of 300 hours or more. The area specific cell resistance, corrected for fuel utilisation, ranged between 0.20 Ω cm2 and 0.34 Ω cm2 at 850 °C and 520 m......V, and between 0.51 Ω cm2 and 0.92 Ω cm2 at 750 °C and 520 mV. The degradation of cell performance was found to be low (ranging from 0 to 8%/1,000 hours) at regular operating conditions. Voltage degradation rates of 20 to 40%/1,000 hours were observed under severe operating conditions, depending on the test...

No detection of Merkel cell polyomavirus in oral lichen planus: Results of a preliminary study in a French cohort of patients.

Science.gov (United States)

Masson Regnault, Marie; Vigarios, Emmanuelle; Projetti, Fabrice; Herbault-Barres, Beatrice; Tournier, Emilie; Lamant, Laurence; Sibaud, Vincent

2017-11-01

Oral lichen planus (OLP) is a chronic inflammatory disease considered as a CD8+ T lymphocyte-mediated autoimmune reaction, which may be triggered by undetermined virus. Recent reports have described the detection of Merkel cell polyomavirus (MCPyV) DNA in oral samples from healthy patients and in patients with different forms of oral cancers. We therefore investigated in a prospective way whether MCPyV was detectable in oral lesions of patients with active OLP. Our preliminary results do not support the hypothesis that OLP may be triggered by MCPyV infection. Further studies are needed to evaluate the involvement of other human polyomaviruses in OLP pathogenesis. © 2017 Wiley Periodicals, Inc.

Characterization of multicrystalline solar cells

International Nuclear Information System (INIS)

Malik, A.Q.; Chong Chew Hah; Chan Siang Khwang; Tan Kha Sheng; Lim Chee Ming

2006-01-01

The evaluation and assessment of the performance of photovoltaic (PV) cells in terms of measurable parameters requires the measurement of the current as a function of voltage, temperature, intensity, wind speed and spectrum. Most noticeable of all these parameters in the PV conversion efficiency η, defined as the maximum electrical power P max produced by the PV cell divided by the incident photon power P in which is measured with respect to standard test conditions (Sc). These conditions refer to the spectrum (AM 1.5), solar radiation intensity (1000 Wm -2 ), cell temperature (25 ± 2 degree C) and wind speed (2 mph). Tests under STC are carried out in the laboratory at a controlled environment. There have been several studies that analyze uncertainties in the laboratory measurement of solar cell efficiencies using different solar simulators and their transference to operational situations. Our preliminary results demonstrate that the short circuit current (I SC ) of the solar cell decreases when irradiance is less than 1000 Wm -2 irrespective of the working temperature of the cell

Characterisation of multicrystalline solar cells

Directory of Open Access Journals (Sweden)

A.Q. Malik

2017-10-01

Full Text Available The evaluation and assessment of the performance of photovoltaic (PV cells in terms of measurable parameters requires the measurement of the current as a function of voltage, temperature, intensity, wind speed and spectrum. Mo st noticeable of all these parameters is the PV conversion efficiency η, defined as the maximum electrical power Pmax produced by the PV cell divided by the incident photon power P in which is measured with respect to standard test conditions (STC. These conditions refer to the spectrum (AM 1.5, solar radiation intensity (1000 Wm-2, cell temperature (25 ±2oC and wind speed (2 mph. Tests under STC are carried out in the laboratory at a controlled environment. There have been several studies that analyze uncertainties in the laboratory measurement of solar cell efficiencies using different solar simulators and their transference to operational situations. Our preliminary results demonstratethat the short circuit current (ISC of the solar cell decreases when irradiance is less than 1000 Wm-2 irrespective of the working temperature of the cell.

Preliminary design package for prototype solar heating system

Energy Technology Data Exchange (ETDEWEB)

1978-12-01

A summary is given of the preliminary analysis and design activity on solar heating systems. The analysis was made without site specific ata other than weather; therefore, the results indicate performance expected under these special conditions. Major items in this report include systeem candidates, design approaches, trade studies and other special data required to evaluate the preliminary analysis and design. The program calls for the development and delivery of eight prototype solar heating and coolin systems for installation and operational test. Two-heating and six heating and cooling units will be delivered for Single Family Residences (SFR), Multi-Family Residences (MFR) and commercial applications.

Performance study of sugar-yeast-ethanol bio-hybrid fuel cells

Science.gov (United States)

Jahnke, Justin P.; Mackie, David M.; Benyamin, Marcus; Ganguli, Rahul; Sumner, James J.

2015-05-01

Renewable alternatives to fossil hydrocarbons for energy generation are of general interest for a variety of political, economic, environmental, and practical reasons. In particular, energy from biomass has many advantages, including safety, sustainability, and the ability to be scavenged from native ecosystems or from waste streams. Microbial fuel cells (MFCs) can take advantage of microorganism metabolism to efficiently use sugar and other biomolecules as fuel, but are limited by low power densities. In contrast, direct alcohol fuel cells (DAFCs) take advantage of proton exchange membranes (PEMs) to generate electricity from alcohols at much higher power densities. Here, we investigate a novel bio-hybrid fuel cell design prepared using commercial off-the-shelf DAFCs. In the bio-hybrid fuel cells, biomass such as sugar is fermented by yeast to ethanol, which can be used to fuel a DAFC. A separation membrane between the fermentation and the DAFC is used to purify the fermentate while avoiding any parasitic power losses. However, shifting the DAFCs from pure alcohol-water solutions to filtered fermented media introduces complications related to how the starting materials, fermentation byproducts, and DAFC waste products affect both the fermentation and the long-term DAFC performance. This study examines the impact of separation membrane pore size, fermentation/fuel cell byproducts, alcohol and salt concentrations, and load resistance on fuel cell performance. Under optimized conditions, the performance obtained is comparable to that of a similar DAFC run with a pure alcohol-water mixture. Additionally, the modified DAFC can provide useable amounts of power for weeks.

Interfacial Layer Engineering for Performance Enhancement in Polymer Solar Cells

Directory of Open Access Journals (Sweden)

Hao Zeng

2015-02-01

Full Text Available Improving power conversion efficiency and device performance stability is the most critical challenge in polymer solar cells for fulfilling their applications in industry at large scale. Various methodologies have been developed for realizing this goal, among them interfacial layer engineering has shown great success, which can optimize the electrical contacts between active layers and electrodes and lead to enhanced charge transport and collection. Interfacial layers also show profound impacts on light absorption and optical distribution of solar irradiation in the active layer and film morphology of the subsequently deposited active layer due to the accompanied surface energy change. Interfacial layer engineering enables the use of high work function metal electrodes without sacrificing device performance, which in combination with the favored kinetic barriers against water and oxygen penetration leads to polymer solar cells with enhanced performance stability. This review provides an overview of the recent progress of different types of interfacial layer materials, including polymers, small molecules, graphene oxides, fullerene derivatives, and metal oxides. Device performance enhancement of the resulting solar cells will be elucidated and the function and operation mechanism of the interfacial layers will be discussed.

Glucose-based Biofuel Cells: Nanotechnology as a Vital Science in Biofuel Cells Performance

Directory of Open Access Journals (Sweden)

Hamideh Aghahosseini

2016-07-01

Full Text Available Nanotechnology has opened up new opportunities for the design of nanoscale electronic devices suitable for developing high-performance biofuel cells. Glucose-based biofuel cells as green energy sources can be a powerful tool in the service of small-scale power source technology as it provides a latent potential to supply power for various implantable medical electronic devices. By using physiologically produced glucose as a fuel, the living battery can recharge for continuous production of electricity. This review article presents how nanoscience, engineering and medicine are combined to assist in the development of renewable glucose-based biofuel cell systems. Here, we review recent advances and applications in both abiotic and enzymatic glucose biofuel cells with emphasis on their “implantable” and “implanted” types. Also the challenges facing the design and application of glucose-based biofuel cells to convert them to promising replacement candidates for non-rechargeable lithium-ion batteries are discussed. Nanotechnology could make glucose-based biofuel cells cheaper, lighter and more efficient and hence it can be a part of the solutions to these challenges.

Effect of localized polycrystalline silicon properties on solar cell performance

Science.gov (United States)

Leung, D.; Iles, P. A.; Hyland, S.; Kachare, A.

1984-01-01

Several forms of polycrystalline silicon, mostly from cast ingots, (including UCP, SILSO and HEM) were studied. On typical slices, localized properties were studied in two ways. Small area (about 2.5 sq mm) mesa diodes were formed, and localized photovoltaic properties were measured. Also a small area (about .015 sq mm) light spot was scanned across the cells; the light spot response was calibrated to measure local diffusion length directly. Using these methods, the effects of grain boundaries, or of intragrain imperfections were correlated with cell performance. Except for the fine grain portion of SILSO, grain boundaries played only a secondary role in determining cell performance. The major factor was intra-grain material quality and it varied with position in ingots and probably related to solidification procedure.

A Preliminary Model for Spacecraft Propulsion Performance Analysis Based on Nuclear Gain and Subsystem Mass-Power Balances

Science.gov (United States)

Chakrabarti, Suman; Schmidt, George R.; Thio, Y. C.; Hurst, Chantelle M.

1999-01-01

A preliminary model for spacecraft propulsion performance analysis based on nuclear gain and subsystem mass-power balances are presented in viewgraph form. For very fast missions with straight-line trajectories, it has been shown that mission trip time is proportional to the cube root of alpha. Analysis of spacecraft power systems via a power balance and examination of gain vs. mass-power ratio has shown: 1) A minimum gain is needed to have enough power for thruster and driver operation; and 2) Increases in gain result in decreases in overall mass-power ratio, which in turn leads to greater achievable accelerations. However, subsystem mass-power ratios and efficiencies are crucial: less efficient values for these can partially offset the effect of nuclear gain. Therefore, it is of interest to monitor the progress of gain-limited subsystem technologies and it is also possible that power-limited systems with sufficiently low alpha may be competitive for such ambitious missions. Topics include Space flight requirements; Spacecraft energy gain; Control theory for performance; Mission assumptions; Round trips: Time and distance; Trip times; Vehicle acceleration; and Minimizing trip times.

Performance of Lithium Polymer Cells with Polyacrylonitrile based Electrolyte

DEFF Research Database (Denmark)

Perera, Kumudu; Dissanayake, M.A.K.L.; Skaarup, Steen

2006-01-01

The performance of lithium polymer cells fabricated with Polyacrylonitrile (PAN) based electrolytes was studied using cycling voltammetry and continuous charge discharge cycling. The electrolytes consisted of PAN, ethylene carbonate (EC), propylene carbonate (PC) and lithium...... trifluoromethanesulfonate (LiCF3SO3 – LiTF). The polymer electrode material was polypyrrole (PPy) doped with dodecyl benzene sulfonate (DBS). The cells were of the form, Li / PAN : EC : PC : LiCF3SO3 / PPy : DBS. Polymer electrodes of three different thicknesses were studied using cycling at different scan rates. All cells...

Development of a moderate rate lithium/thionyl-chloride D'' cell

Energy Technology Data Exchange (ETDEWEB)

Cieslak, W.R.; Street, H.K.

1990-01-01

We have designed a lithium/thionyl chloride D'' cell for efficient performance at the moderate rate of {approximately}500 mA (6.25 {Omega} load). The SNL-MR-D cell has 345 cm{sup 2} of active electrode area, 1.0 M LiAlCl{sub 4} electrolyte that may have SO{sub 2} additive, and a cathode blended of Shawinigan Acetylene Black, Cabot Black Pearls 2000, and Teflon binder. The average performance of cells built in-house and discharged at 25{degree}C and 6.25 {Omega} has been 14.9 Ah (50 Wh). We have aged the cells at 30{degree}C and 50{degree}C, and measured complex impedance and microcalorimetry during the aging period. The cells have been discharged after the aging period at 25{degree}C and 0{degree}C. This preliminary study has allowed us to establish an initial cell design and estimate the rate of capacity loss on storage or long-term usage. 13 refs., 6 figs.

The TMI regenerable solid oxide fuel cell

Science.gov (United States)

Cable, Thomas L.

1995-04-01

Energy storage and production in space requires rugged, reliable hardware which minimizes weight, volume, and maintenance while maximizing power output and usable energy storage. These systems generally consist of photovoltaic solar arrays which operate during sunlight cycles to provide system power and regenerate fuel (hydrogen) via water electrolysis; during dark cycles, hydrogen is converted by the fuel cell into system. The currently preferred configuration uses two separate systems (fuel cell and electrolyzer) in conjunction with photovoltaic cells. Fuel cell/electrolyzer system simplicity, reliability, and power-to-weight and power-to-volume ratios could be greatly improved if both power production (fuel cell) and power storage (electrolysis) functions can be integrated into a single unit. The Technology Management, Inc. (TMI), solid oxide fuel cell-based system offers the opportunity to both integrate fuel cell and electrolyzer functions into one unit and potentially simplify system requirements. Based an the TMI solid oxide fuel cell (SOPC) technology, the TMI integrated fuel cell/electrolyzer utilizes innovative gas storage and operational concepts and operates like a rechargeable 'hydrogen-oxygen battery'. Preliminary research has been completed on improved H2/H2O electrode (SOFC anode/electrolyzer cathode) materials for solid oxide, regenerative fuel cells. Improved H2/H2O electrode materials showed improved cell performance in both fuel cell and electrolysis modes in reversible cell tests. ln reversible fuel cell/electrolyzer mode, regenerative fuel cell efficiencies (ratio of power out (fuel cell mode) to power in (electrolyzer model)) improved from 50 percent (using conventional electrode materials) to over 80 percent. The new materials will allow the TMI SOFC system to operate as both the electrolyzer and fuel cell in a single unit. Preliminary system designs have also been developed which indicate the technical feasibility of using the TMI SOFC

Influences of bipolar plate channel blockages on PEM fuel cell performances

International Nuclear Information System (INIS)

Heidary, Hadi; Kermani, Mohammad J.; Dabir, Bahram

2016-01-01

Highlights: • Effect of partial- or full-blockage of PEMFC flow channels is numerically studied. • The anode blockage does not show any positive effects on cell performance. • Full blockages, despite higher pressure drop, better enhance net electrical power. • Additions of blocks more than five do not improve the cell performance. • Full blockage of cathode channels with five blocks enhances the net power by 30%. - Abstract: In this paper, the effect of partial- or full-block placement along the flow channels of PEM fuel cells is numerically studied. Blockage in the channel of flow-field diverts the flow into the gas diffusion layer (GDL) and enhances the mass transport from the channel core part to the catalyst layer, which in turn improves the cell performance. By partial blockage, only a part of the channel flow is shut off. While in full blockage, in which the flow channel cross sections are fully blocked, the only avenue left for the continuation of the gas is to travel over the blocks via the porous zone (GDL). In this study, a 3D numerical model consisting of a 9-layer PEM fuel cell is performed. A wide spectrum of numerical studies is performed to study the influences of the number of blocks, blocks height, and anode/cathode-side flow channel blockage. The results show that the case of full blockage enhances the net electrical power more than that of the partial blockage, in spite of higher pressure drop. Performed studies show that full blockage of the cathode-side flow channels with five blocks along the 5 cm channel enhances the net power by 30%. The present work provides helpful guidelines to bipolar plate manufacturers.

Preliminary conceptual design and analysis on KALIMER reactor structures

International Nuclear Information System (INIS)

Kim, Jong Bum

1996-10-01

The objectives of this study are to perform preliminary conceptual design and structural analyses for KALIMER (Korea Advanced Liquid Metal Reactor) reactor structures to assess the design feasibility and to identify detailed analysis requirements. KALIMER thermal hydraulic system analysis results and neutronic analysis results are not available at present, only-limited preliminary structural analyses have been performed with the assumptions on the thermal loads. The responses of reactor vessel and reactor internal structures were based on the temperature difference of core inlet and outlet and on engineering judgments. Thermal stresses from the assumed temperatures were calculated using ANSYS code through parametric finite element heat transfer and elastic stress analyses. While, based on the results of preliminary conceptual design and structural analyses, the ASME Code limits for the reactor structures were satisfied for the pressure boundary, the needs for inelastic analyses were indicated for evaluation of design adequacy of the support barrel and the thermal liner. To reduce thermal striping effects in the bottom are of UIS due to up-flowing sodium form reactor core, installation of Inconel-718 liner to the bottom area was proposed, and to mitigate thermal shock loads, additional stainless steel liner was also suggested. The design feasibilities of these were validated through simplified preliminary analyses. In conceptual design phase, the implementation of these results will be made for the design of the reactor structures and the reactor internal structures in conjunction with the thermal hydraulic, neutronic, and seismic analyses results. 4 tabs., 24 figs., 4 refs. (Author)

Long-Term Performance of Uranium Tailings Disposal Cells - 13340

International Nuclear Information System (INIS)

Bostick, Kent; Daniel, Anamary; Pill, Ken; Tachiev, Georgio; Noosai, Nantaporn; Villamizar, Viviana

2013-01-01

Recently, there has been interest in the performance and evolution of Uranium Mill Tailings Remedial Action (UMTRA) Project disposal cell covers because some sites are not compliant with groundwater standards. Field observations of UMTRA disposal cells indicate that rock covers tend to become vegetated and that saturated conductivities in the upper portion of radon barriers may increase due to freeze/thaw cycles and biointrusion. This paper describes the results of modeling that addresses whether these potential changes and transient drainage of moisture in the tailings affect overall performance of the disposal cells. A numerical unsaturated/saturated 3-dimensional flow model was used to simulate whether increases in saturated conductivities in radon barriers with rock covers affect the overall performance of the disposal cells using field data from the Shiprock, NM, UMTRA site. A unique modeling approach allowed simulation with daily climatic conditions to determine changes in moisture and moisture flux from the disposal cell. Modeling results indicated that increases in the saturated conductivity at the top of radon barrier do not influence flux from the tailings with time because the tailings behave similar hydraulically to the radon barrier. The presence of a thin layer of low conductivity material anywhere in the cover or tailings restricts flux in the worst case to the saturated conductivity of that material. Where materials are unsaturated at depth within the radon barrier of tailings slimes, conductivities are typically less than 10 -8 centimeters per second. If the low conductivity layer is deep within the disposal cell, its saturated properties are less likely to change with time. The significance of this modeling is that operation and maintenance of the disposal cells can be minimized if they are allowed to progress to a natural condition with some vegetation and soil genesis. Because the covers and underlying tailings have a very low saturated

Long-Term Performance of Uranium Tailings Disposal Cells - 13340

Energy Technology Data Exchange (ETDEWEB)

Bostick, Kent; Daniel, Anamary; Pill, Ken [Professional Project Services, Inc., 1100 Bethel Valley Road, Oak Ridge, TN, 37922 (United States); Tachiev, Georgio; Noosai, Nantaporn; Villamizar, Viviana [Florida International University, 10555 W. Flagler St., EC 2100, Miami FL, 33174 (United States)

2013-07-01

Recently, there has been interest in the performance and evolution of Uranium Mill Tailings Remedial Action (UMTRA) Project disposal cell covers because some sites are not compliant with groundwater standards. Field observations of UMTRA disposal cells indicate that rock covers tend to become vegetated and that saturated conductivities in the upper portion of radon barriers may increase due to freeze/thaw cycles and biointrusion. This paper describes the results of modeling that addresses whether these potential changes and transient drainage of moisture in the tailings affect overall performance of the disposal cells. A numerical unsaturated/saturated 3-dimensional flow model was used to simulate whether increases in saturated conductivities in radon barriers with rock covers affect the overall performance of the disposal cells using field data from the Shiprock, NM, UMTRA site. A unique modeling approach allowed simulation with daily climatic conditions to determine changes in moisture and moisture flux from the disposal cell. Modeling results indicated that increases in the saturated conductivity at the top of radon barrier do not influence flux from the tailings with time because the tailings behave similar hydraulically to the radon barrier. The presence of a thin layer of low conductivity material anywhere in the cover or tailings restricts flux in the worst case to the saturated conductivity of that material. Where materials are unsaturated at depth within the radon barrier of tailings slimes, conductivities are typically less than 10{sup -8} centimeters per second. If the low conductivity layer is deep within the disposal cell, its saturated properties are less likely to change with time. The significance of this modeling is that operation and maintenance of the disposal cells can be minimized if they are allowed to progress to a natural condition with some vegetation and soil genesis. Because the covers and underlying tailings have a very low saturated

Systems, methods and computer-readable media for modeling cell performance fade of rechargeable electrochemical devices

Science.gov (United States)

Gering, Kevin L

2013-08-27

A system includes an electrochemical cell, monitoring hardware, and a computing system. The monitoring hardware periodically samples performance characteristics of the electrochemical cell. The computing system determines cell information from the performance characteristics of the electrochemical cell. The computing system also develops a mechanistic level model of the electrochemical cell to determine performance fade characteristics of the electrochemical cell and analyzing the mechanistic level model to estimate performance fade characteristics over aging of a similar electrochemical cell. The mechanistic level model uses first constant-current pulses applied to the electrochemical cell at a first aging period and at three or more current values bracketing a first exchange current density. The mechanistic level model also is based on second constant-current pulses applied to the electrochemical cell at a second aging period and at three or more current values bracketing the second exchange current density.

Effects of dimethyl ether on the performance characteristics of a direct methanol fuel cell

International Nuclear Information System (INIS)

Seo, Sang Hern; Lee, Chang Sik

2013-01-01

Highlights: • Activation loss is significantly reduced in fuel cell with DME-methanol. • DME crossover through the membrane reduces. • The open circuit voltage of DME-methanol the fuel cell increases. • The overall efficiency of the mixed fuel cell is higher than that of DMFC. - Abstract: The objective of this study was to determine the effects of dimethyl ether (DME) on the performance characteristics of a direct methanol fuel cell. Impedance and crossover experiments were performed in order to investigate the performance losses such as ohmic loss, activation loss and crossover loss accurately. The DME was pressurized to 5 bar to supply with liquid phase was and blended with an aqueous methanol solution. In this experiment, the membrane electrode assembly (MEA) was composed of Nafion 115, anode catalyst loaded Pt–Ru and cathode catalyst loaded Pt-Black. Experimental results showed that fuel cells with DME-methanol enhanced performance when compared to fuel cells with methanol only. Such performance enhancement was due to a decrease in activation losses by DME oxidation reactions. As the DME crossover through the membrane was reduced, the open circuit voltage (OCV) of the fuel cell increased. Other output characteristics are also discussed

High Performance Fuel Cell and Electrolyzer Membrane Electrode Assemblies (MEAs) for Space Energy Storage Systems

Science.gov (United States)

Valdez, Thomas I.; Billings, Keith J.; Kisor, Adam; Bennett, William R.; Jakupca, Ian J.; Burke, Kenneth; Hoberecht, Mark A.

2012-01-01

Regenerative fuel cells provide a pathway to energy storage system development that are game changers for NASA missions. The fuel cell/ electrolysis MEA performance requirements 0.92 V/ 1.44 V at 200 mA/cm2 can be met. Fuel Cell MEAs have been incorporated into advanced NFT stacks. Electrolyzer stack development in progress. Fuel Cell MEA performance is a strong function of membrane selection, membrane selection will be driven by durability requirements. Electrolyzer MEA performance is catalysts driven, catalyst selection will be driven by durability requirements. Round Trip Efficiency, based on a cell performance, is approximately 65%.

Hot wire deposited hydrogenated amorphous silicon solar cells

Energy Technology Data Exchange (ETDEWEB)

Mahan, A.H.; Iwaniczko, E.; Nelson, B.P.; Reedy, R.C. Jr.; Crandall, R.S. [National Renewable Energy Lab., Golden, CO (United States)

1996-05-01

This paper details the results of a study in which low H content, high deposition rate hot wire (HW) deposited amorphous silicon (a-Si:H) has been incorporated into a substrate solar cell. The authors find that the treatment of the top surface of the HW i layer while it is being cooled from its high deposition temperature is crucial to device performance. They present data concerning these surface treatments, and correlate these treatments with Schottky device performance. The authors also present first generation HW n-i-p solar cell efficiency data, where a glow discharge (GD) {mu}c-Si(p) layer was added to complete the partial devices. No light trapping layer was used to increase the device Jsc. Their preliminary investigations have yielded efficiencies of up to 6.8% for a cell with a 4000 {Angstrom} thick HW i-layer, which degrade less than 10% after a 900 hour light soak. The authors suggest avenues for further improvement of their devices.

Silicon materials task of the Low Cost Solar Array Project: Effect of impurities and processing on silicon solar cells

Science.gov (United States)

Hopkins, R. H.; Davis, J. R.; Rohatgi, A.; Hanes, M. H.; Rai-Choudhury, P.; Mollenkopf, H. C.

1982-01-01

The effects of impurities and processing on the characteristics of silicon and terrestrial silicon solar cells were defined in order to develop cost benefit relationships for the use of cheaper, less pure solar grades of silicon. The amount of concentrations of commonly encountered impurities that can be tolerated in typical p or n base solar cells was established, then a preliminary analytical model from which the cell performance could be projected depending on the kinds and amounts of contaminants in the silicon base material was developed. The impurity data base was expanded to include construction materials, and the impurity performace model was refined to account for additional effects such as base resistivity, grain boundary interactions, thermal processing, synergic behavior, and nonuniform impurity distributions. A preliminary assessment of long term (aging) behavior of impurities was also undertaken.

Preliminary characterization of abandoned septic tank systems. Volume 1

International Nuclear Information System (INIS)

1995-12-01

This report documents the activities and findings of the Phase I Preliminary Characterization of Abandoned Septic Tank Systems. The purpose of the preliminary characterization activity was to investigate the Tiger Team abandoned septic systems (tanks and associated leachfields) for the purpose of identifying waste streams for closure at a later date. The work performed was not to fully characterize or remediate the sites. The abandoned systems potentially received wastes or effluent from buildings which could have discharged non-domestic, petroleum hydrocarbons, hazardous, radioactive and/or mixed wastes. A total of 20 sites were investigated for the preliminary characterization of identified abandoned septic systems. Of the 20 sites, 19 were located and characterized through samples collected from each tank(s) and, where applicable, associated leachfields. The abandoned septic tank systems are located in Areas 5, 12, 15, 25, and 26 on the Nevada Test Site

Serotonin transporter bi- and triallelic genotypes and their relationship with anxiety and academic performance: a preliminary study.

Science.gov (United States)

Calapoğlu, Mustafa; Sahin-Calapoğlu, Nilufer; Karaçöp, Ataman; Soyöz, Mustafa; Elyıldırım, Umit Y; Avşaroğlu, Selahattin

2011-01-01

Considerable evidence suggests that variation of the serotonin-transporter-linked promoter region (5- HTTLPR) is associated with anxiety-related traits. Academic outcomes are also more closely related to trait anxiety. This preliminary study aimed to explore the association between academic performance and levels of anxiety with respect to the bi- and triallelic classification of 5-HTTLPR polymorphism of the 5-HTT gene in teacher candidates. In our study, Spielberger's State-Trait Anxiety Inventory, the Selection Examination for Professional Posts in Public Organizations (KPSS) and 5-HTTLPR genotypes were used to investigate a group of 94 healthy teacher candidates. Higher anxiety scores were significantly associated with the S'S' genotype. There was no direct, statistically significant association between academic performance and genotypic groups regarding bi- and triallelic classification. However, the students who have L'L' or LL genotypes had the lowest levels of trait anxiety and the poorest academic performance. Additionally, there was a significant positive correlation between academic performance and anxiety levels. These findings support the idea that S and L(G) alleles are associated with anxiety-related traits, and that the S'S' genotype may be a good indicator for anxiety-related traits in a sample from the Turkish population. A specific degree of anxiety is considered to be a motivation for learning and high academic performance. However, 5-HTTLPR polymorphism of the 5-HTT gene may be one of the genetic factors affecting academic performance in connection with anxiety levels. Implications for incorporating anxiety management training in the educational process in terms of both environmental and individual factors will have a very important role in improving effective strategies for student personality services, as well as for development and planning. © 2010 S. Karger AG, Basel.

HTGR gas turbine power plant preliminary design

International Nuclear Information System (INIS)

Koutz, S.L.; Krase, J.M.; Meyer, L.

1973-01-01

The preliminary reference design of the HTGR gas turbine power plant is presented. Economic and practical problems and incentives related to the development and introduction of this type of power plant are evaluated. The plant features and major components are described, and a discussion of its performance, economics, development, safety, control, and maintenance is presented. 4 references

Production, crystallization and preliminary X-ray diffraction analysis of the allergen Can f 2 from Canis familiaris

International Nuclear Information System (INIS)

Madhurantakam, Chaithanya; Nilsson, Ola B.; Jönsson, Klas; Grönlund, Hans; Achour, Adnane

2009-01-01

The recombinant form of the allergen Can f 2 from C. familiaris was produced, isolated and crystallized in two different forms. Preliminary X-ray diffraction analyses are reported for the two crystal forms of Can f 2. The allergen Can f 2 from dog (Canis familiaris) present in saliva, dander and fur is an important cause of allergic sensitization worldwide. Here, the production, isolation, crystallization and preliminary X-ray diffraction analysis of two crystal forms of recombinant Can f 2 are reported. The first crystal form belonged to space group C222, with unit-cell parameters a = 68.7, b = 77.3, c = 65.1 Å, and diffracted to 1.55 Å resolution, while the second crystal form belonged to space group C2, with unit-cell parameters a = 75.7, b = 48.3, c = 68.7 Å, β = 126.5°, and diffracted to 2.1 Å resolution. Preliminary data analysis indicated the presence of a single molecule in the asymmetric unit for both crystal forms

Characterization of high performance silicon-based VMJ PV cells for laser power transmission applications

Science.gov (United States)

Perales, Mico; Yang, Mei-huan; Wu, Cheng-liang; Hsu, Chin-wei; Chao, Wei-sheng; Chen, Kun-hsien; Zahuranec, Terry

2016-03-01

Continuing improvements in the cost and power of laser diodes have been critical in launching the emerging fields of power over fiber (PoF), and laser power beaming. Laser power is transmitted either over fiber (for PoF), or through free space (power beaming), and is converted to electricity by photovoltaic cells designed to efficiently convert the laser light. MH GoPower's vertical multi-junction (VMJ) PV cell, designed for high intensity photovoltaic applications, is fueling the emergence of this market, by enabling unparalleled photovoltaic receiver flexibility in voltage, cell size, and power output. Our research examined the use of the VMJ PV cell for laser power transmission applications. We fully characterized the performance of the VMJ PV cell under various laser conditions, including multiple near IR wavelengths and light intensities up to tens of watts per cm2. Results indicated VMJ PV cell efficiency over 40% for 9xx nm wavelengths, at laser power densities near 30 W/cm2. We also investigated the impact of the physical dimensions (length, width, and height) of the VMJ PV cell on its performance, showing similarly high performance across a wide range of cell dimensions. We then evaluated the VMJ PV cell performance within the power over fiber application, examining the cell's effectiveness in receiver packages that deliver target voltage, intensity, and power levels. By designing and characterizing multiple receivers, we illustrated techniques for packaging the VMJ PV cell for achieving high performance (> 30%), high power (> 185 W), and target voltages for power over fiber applications.

A Preliminary Study on Cathodic Prevention in Reinforced Mortar

NARCIS (Netherlands)

Koleva, D.A.; Van Breugel, K.; Mol, J.M.C.; De Wit, J.H.W.

2010-01-01

This work presents the preliminary tests on the performance of cathodic prevention (CPre) in reinforced mortar, subjected to aggressive (10% NaCl environment). Cathodic prevention is an electrochemical technique for minimizing, actually "preventing" any eventual corrosion of the steel bars in

Hydrogen Production Performance of a 10-Cell Planar Solid-Oxide Electrolysis Stack

International Nuclear Information System (INIS)

James O'Brien; Carl Stoots; Steve Herring; J. Hartvigsen

2005-01-01

An experimental study is under way to assess the performance of solid-oxide cells operating in the steam electrolysis mode for hydrogen production over a temperature range of 800 to 900 C. Results presented in this paper were obtained from a ten-cell planar electrolysis stack, with an active area of 64 cm2 per cell. The electrolysis cells are electrolyte supported, with scandia-stabilized zirconia electrolytes (∼140 (micro)m thick), nickel-cermet steam/hydrogen electrodes, and manganite air-side electrodes. The metallic interconnect plates are fabricated from ferritic stainless steel. The experiments were performed over a range of steam inlet mole fractions (0.1-0.6), gas flow rates (1000-4000 sccm), and current densities (0 to 0.38 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. Cell operating potentials and cell current were varied using a programmable power supply. Hydrogen production rates up to 100 Normal liters per hour were demonstrated. Values of area-specific resistance and stack internal temperatures are presented as a function of current density. Stack performance is shown to be dependent on inlet steam flow rate

Performance prediction of a proton exchange membrane fuel cell using the ANFIS model

Energy Technology Data Exchange (ETDEWEB)

Vural, Yasemin; Ingham, Derek B.; Pourkashanian, Mohamed [Centre for Computational Fluid Dynamics, University of Leeds, Houldsworth Building, LS2 9JT Leeds (United Kingdom)

2009-11-15

In this study, the performance (current-voltage curve) prediction of a Proton Exchange Membrane Fuel Cell (PEMFC) is performed for different operational conditions using an Adaptive Neuro-Fuzzy Inference System (ANFIS). First, ANFIS is trained with a set of input and output data. The trained model is then tested with an independent set of experimental data. The trained and tested model is then used to predict the performance curve of the PEMFC under various operational conditions. The model shows very good agreement with the experimental data and this indicates that ANFIS is capable of predicting fuel cell performance (in terms of cell voltage) with a high accuracy in an easy, rapid and cost effective way for the case presented. Finally, the capabilities and the limitations of the model for the application in fuel cells have been discussed. (author)

Disruptive effect of Dzyaloshinskii-Moriya interaction on the magnetic memory cell performance

Energy Technology Data Exchange (ETDEWEB)

Sampaio, J.; Cubukcu, M.; Cros, V.; Reyren, N., E-mail: nicolas.reyren@thalesgroup.com [Unité Mixte de Physique, CNRS, Thales, Univ. Paris-Sud, Université Paris-Saclay, 91767, Palaiseau (France); Khvalkovskiy, A. V. [Samsung Electronics, Semiconductor R& D Center (Grandis), San Jose, California 95134 (United States); Moscow Institute of Physics and Technology, State University, Moscow 141700 (Russian Federation); Kuteifan, M.; Lomakin, V. [Department of Electrical and Computer Engineering, University of California at San Diego, La Jolla, California 92093-0407 (United States); Apalkov, D. [Samsung Electronics, Semiconductor R& D Center (Grandis), San Jose, California 95134 (United States)

2016-03-14

In order to increase the thermal stability of a magnetic random access memory cell, materials with high spin-orbit interaction are often introduced in the storage layer. As a side effect, a strong Dzyaloshinskii-Moriya interaction (DMI) may arise in such systems. Here, we investigate the impact of DMI on the magnetic cell performance, using micromagnetic simulations. We find that DMI strongly promotes non-uniform magnetization states and non-uniform switching modes of the magnetic layer. It appears to be detrimental for both the thermal stability of the cell and its switching current, leading to considerable deterioration of the cell performance even for a moderate DMI amplitude.

Meteosat third generation: preliminary imagery and sounding mission concepts and performances

Science.gov (United States)

Aminou, Donny M.; Bézy, Jean-Loup; Bensi, Paolo; Stuhlmann, Rolf; Rodriguez, Antonio

2017-11-01

The operational deployment of MSG-1 at the beginning of 2004, the first of a series of four Meteosat Second Generation (MSG) satellites, marks the start of a new era in Europe for the meteorological observations from the geostationary orbit. This new system shall be the backbone of the European operational meteorological services up to at least 2015. The time required for the definition and the development of new space systems as well as the approval process of such complex programs implies to plan well ahead for the future missions. EUMETSAT have initiated in 2001, with ESA support, a User Consultation Process aiming at preparing for a future operational geostationary meteorological satellite system in the post-MSG era, named Meteosat Third Generation (MTG). The first phase of the User Consultation Process was devoted to the definition and consolidation of end user requirements and priorities in the field of Nowcasting and Very Short Term Weather Forecasting (NWC), Medium/Short Range global and regional Numerical Weather Prediction (NWP), Climate and Air Composition Monitoring and to the definition of the relevant observation techniques. After an initial post-MSG mission study (2003-2004) where preliminary instrument concepts were investigated allowing in the same time to consolidate the technical requirements for the overall system study, a MTG pre-phase A study has been performed for the overall system concept, architecture and programmatic aspects during 2004-2005 time frame. This paper provides an overview of the outcome of the MTG sensor concept studies conducted in the frame of the pre-phase A. It namely focuses onto the Imaging and Sounding Missions, highlights the resulting instrument concepts, establishes the critical technologies and introduces the study steps towards the implementation of the MTG development programme.

Performance comparison of low-temperature direct alcohol fuel cells with different anode catalysts

Science.gov (United States)

Zhou, W. J.; Zhou, B.; Li, W. Z.; Zhou, Z. H.; Song, S. Q.; Sun, G. Q.; Xin, Q.; Douvartzides, S.; Goula, M.; Tsiakaras, P.

Low-temperature polymer electrolyte membrane fuel cells directly fed by methanol and ethanol were investigated employing carbon supported Pt, PtSn and PtRu as anode catalysts, respectively. Employing Pt/C as anode catalyst, both direct methanol fuel cell (DMFC) and direct ethanol fuel cell (DEFC) showed poor performances even in presence of high Pt loading on anode. It was found that the addition of Ru or Sn to the Pt dramatically enhances the electro-oxidation of both methanol and ethanol. It was also found that the single cell adopting PtRu/C as anode shows better DMFC performance, while PtSn/C catalyst shows better DEFC performance. The single fuel cell using PtSn/C as anode catalyst at 90 °C shows similar power densities whenever fueled by methanol or ethanol. The cyclic voltammetry (CV) and single fuel cell tests indicated that PtRu is more suitable for DMFC while PtSn is more suitable for DEFC.

"Imaging" LEIS of micro-patterned solid oxide fuel cell electrodes

Science.gov (United States)

Druce, John; Simrick, Neil; Ishihara, Tatsumi; Kilner, John

2014-08-01

Understanding the kinetics of oxygen exchange between the gas phase and a ceramic electrode is key to optimising the performance of electrochemical energy conversion devices such as Solid Oxide Fuel Cells. Clearly the surface chemistry of these materials is important, and surface sensitive techniques such as Low Energy Ion Scattering (LEIS) can provide important compositional information key to unravelling electrode kinetics. In this work, we use high lateral resolution LEIS to perform local analyses of a micropatterned electrode structure, of the type often used for studies of the geometrical dependences of electrode performance. We find that the results are comparable to those for bulk materials, but detect evidence of cation interdiffusion from the electrode to the electrolyte. Finally, we note that this preliminary study could open the prospect of in situ measurements of cells near operating conditions.

Enhancement in photovoltaic performance of phthalocyanine-sensitized solar cells by attapulgite nanoparticles

International Nuclear Information System (INIS)

Jin Ling; Chen Dajun

2012-01-01

Highlights: ► Dye-sensitized solar cells sensitized by zinc octacarboxylic phthalocyanine. ► Attapulgite nanoparticles have been used to suppress phthalocyanine aggregation. ► Adding attapulgite improves the photovoltaic performance of the dye-sensitized solar cells. - Abstract: Attapulgite nanoparticles were used to improve photovoltaic performance of phthalocyanine-sensitized solar cells. The effects of attapulgite on the devices were investigated in details. Adding of attapulgite into TiO 2 electrodes not only reduced the adsorption of zinc octacarboxylic phthalocyanine but also prevented phthalocyanine aggregation effect, which greatly improved photovoltaic performance of the dye-sensitized solar cell. The solar cell with 10 mg attapulgite nanoparticles dispersed in the dye solution exhibited nearly three times larger photoelectric conversion efficiency under simulated AM 1.5 G irradiation (100 mW cm −2 ) when compared to the pure dye, which was further characterized by the electrochemical impedance spectroscopy (EIS). The EIS studies showed that attapulgite decreased the charge-transfer resistances at the TiO 2 /dye/electrolyte interface, which can promote electron transport.

Analysis and performance of adjacent-cell preconditioners for accelerating multidimensional transport calculations

International Nuclear Information System (INIS)

Azmy, Y.Y.

1996-01-01

The formal development of the Adjacent-cell Preconditioner (AP) and its implementation in the TORT code are briefly reviewed. Based on earlier experience with diffusion type acceleration, and excellent results in slab geometry the reciprocal averaging formula is used to mix the preconditioner elements across material and mesh discontinuities. Numerical testing of the method employing the Burre Suite of Test Problems (BSTeP), a collection of 144 cases covering a wide range in parameter space, using AP, Partial Current Rebalance (PCR), and TWODANT's Diffusion Synthetic Acceleration (DSA) is presented. While AP outperforms the other two methods for the majority of the cases included in BSTeP it consumes many more iterations than can be explained by spectral analysis of the homogeneous model problem in cases with sharp material discontinuity. In order to verify this undesirable behavior and explore potential remedies a model problem, the Periodic Horizontal Interface (PHI), is developed that permits discontinuity of nuclear properties and cell height across the interface. Fourier mode decomposition is applied to AP with the reciprocal averaging mixing formula for the PHI configuration and shown to possess a spectral radius that approaches unity as the material discontinuity gets larger. The question of whether an unconditionally stable AP exists for PHI is tackled and preliminary indications are negative. Novel preconditioners that have nontraditional cell-coupling schemes that remain stable in these regimes may have to be sought

Graphene liquid cells for multi-technique analysis of biological cells in water environment

Science.gov (United States)

Matruglio, A.; Zucchiatti, P.; Birarda, G.; Marmiroli, B.; D'Amico, F.; Kocabas, C.; Kiskinova, M.; Vaccari, L.

2018-05-01

In-cell exploration of biomolecular constituents is the new frontier of cellular biology that will allow full access to structure-activity correlation of biomolecules, overcoming the limitations imposed by dissecting the cellular milieu. However, the presence of water, which is a very strong IR absorber and incompatible with the vacuum working conditions of all analytical methods using soft x-rays and electrons, poses severe constraint to perform important imaging and spectroscopic analyses under physiological conditions. Recent advances to separate the sample compartment in liquid cell are based on electron and photon transparent but molecular-impermeable graphene membranes. This strategy has opened a unique opportunity to explore technological materials under realistic operation conditions using various types of electron microscopy. However, the widespread of the graphene liquid cell applications is still impeded by the lack of well-established approaches for their massive production. We report on the first preliminary results for the fabrication of reproducible graphene liquid cells appropriate for the analysis of biological specimens in their natural hydrated environment with several crucial analytical techniques, namely FTIR microscopy, Raman spectroscopy, AFM, SEM and TEM.

Microstructured Electrolyte Membranes to Improve Fuel Cell Performance

Science.gov (United States)

Wei, Xue

Fuel cells, with the advantages of high efficiency, low greenhouse gas emission, and long lifetime are a promising technology for both portable power and stationary power sources. The development of efficient electrolyte membranes with high ionic conductivity, good mechanical durability and dense structure at low cost remains a challenge to the commercialization of fuel cells. This thesis focuses on exploring novel composite polymer membranes and ceramic electrolytes with the microstructure engineered to improve performance in direct methanol fuel cells (DMFCs) and solid oxide fuel cells (SOFCs), respectively. Polymer/particle composite membranes hold promise to meet the demands of DMFCs at lower cost. The structure of composite membranes was controlled by aligning proton conducting particles across the membrane thickness under an applied electric field. The field-induced structural changes caused the membranes to display an enhanced water uptake, proton conductivity, and methanol permeability in comparison to membranes prepared without an applied field. Although both methanol permeability and proton conductivity are enhanced by the applied field, the permeability increase is relatively lower than the proton conductivity improvement, which results in enhanced proton/methanol selectivity and improved DMFC performance. Apatite ceramics are a new class of fast ion conductors being studied as alternative SOFC electrolytes in the intermediate temperature range. An electrochemical/hydrothermal deposition method was developed to grow fully dense apatite membranes containing well-developed crystals with c-axis alignment to promote ion conductivity. Hydroxyapatite seed crystals were first deposited onto a metal substrate electrochemically. Subsequent ion substitution during the hydrothermal growth process promoted the formation of dense, fully crystalline films with microstructure optimal for ion transport. The deposition parameters were systematically investigated, such as

Study of double porous silicon surfaces for enhancement of silicon solar cell performance

Science.gov (United States)

Razali, N. S. M.; Rahim, A. F. A.; Radzali, R.; Mahmood, A.

2017-09-01

In this work, design and simulation of double porous silicon surfaces for enhancement of silicon solar cell is carried out. Both single and double porous structures are constructed by using TCAD ATHENA and TCAD DEVEDIT tools of the SILVACO software respectively. After the structures were created, I-V characteristics and spectral response of the solar cell were extracted using ATLAS device simulator. Finally, the performance of the simulated double porous solar cell is compared with the performance of both single porous and bulk-Si solar cell. The results showed that double porous silicon solar cell exhibited 1.8% efficiency compared to 1.3% and 1.2% for single porous silicon and bulk-Si solar cell.

Preliminary evaluation of the tibial tuberosity-trochlear groove measurement

DEFF Research Database (Denmark)

Miles, James Edward; Kirpensteijn, Jolle; Svalastoga, Eiliv Lars

guide surgical treatment. The TTTG measures tibial tuberosity position relative to the axis of the femoral trochlea. A preliminary investigation of TTTG measurement was performed using the red fox (Vulpes vulpes) cadavers as a morphologically similar and homogenous substitute for dog cadavers. CT...

Enhanced photovoltaic performance of an inclined nanowire array solar cell.

Science.gov (United States)

Wu, Yao; Yan, Xin; Zhang, Xia; Ren, Xiaomin

2015-11-30

An innovative solar cell based on inclined p-i-n nanowire array is designed and analyzed. The results show that the inclined geometry can sufficiently increase the conversion efficiency of solar cells by enhancing the absorption of light in the active region. By tuning the nanowire array density, nanowire diameter, nanowire length, as well as the proportion of intrinsic region of the inclined nanowire solar cell, a remarkable efficiency in excess of 16% can be obtained in GaAs. Similar results have been obtained in InP and Si nanowire solar cells, demonstrating the universality of the performance enhancement of inclined nanowire arrays.

Long Term Performance Study of a Direct Methanol Fuel Cell Fed with Alcohol Blends

Directory of Open Access Journals (Sweden)

Eleuterio Mora

2013-01-01

Full Text Available The use of alcohol blends in direct alcohol fuel cells may be a more environmentally friendly and less toxic alternative to the use of methanol alone in direct methanol fuel cells. This paper assesses the behaviour of a direct methanol fuel cell fed with aqueous methanol, aqueous ethanol and aqueous methanol/ethanol blends in a long term experimental study followed by modelling of polarization curves. Fuel cell performance is seen to decrease as the ethanol content rises, and subsequent operation with aqueous methanol only partly reverts this loss of performance. It seems that the difference in the oxidation rate of these alcohols may not be the only factor affecting fuel cell performance.

Biomass gasification and fuel cells: system with PEM fuel cell; Gaseificacao de biomassa e celula a combustivel: sistema com celula tipo PEMFC

Energy Technology Data Exchange (ETDEWEB)

Sordi, Alexandre; Lobkov, Dmitri D.; Lopes, Daniel Gabriel; Rodrigues, Jean Robert Pereira [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Fac. de Engenharia Mecanica], e-mail: asordi@fem.unicamp.br, e-mail: lobkov@fem.unicamp.br, e-mail: danielg@fem.unicamp.br, e-mail: jrobert@fem.unicamp.br; Silva, Ennio Peres da [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Inst. de Fisica Gleb Wataghin], e-mail: Lh2ennio@ifi.unicamp.br

2006-07-01

The objective of this paper is to present the operation flow diagram of an electricity generation system based on the biomass integrated gasification fuel cell of the type PEMFC (Proton Exchange Membrane Fuel Cell). The integration between the gasification and a fuel cell of this type consists of the gas methane (CH4) reforming contained in the synthesis gas, the conversion of the carbon monoxide (CO), and the cleaning of the gaseous flow through a PSA (Pressure Swing Adsorption) system. A preliminary analysis was carried out to estimate the efficiency of the system with and without methane gas reforming. The performance was also analyzed for different gasification gas compositions, for larger molar fractions of hydrogen and methane. The system electrical efficiency was 29% respective to the lower heating value of the gasification gas. The larger the molar fraction of hydrogen at the shift reactor exit, the better the PSA exergetic performance. Comparative analysis with small gas turbines exhibited the superiority of the PEMFC system. (author)

A preliminary study of a miniature planar 6-cell PEMFC stack combined with a small hydrogen storage canister

Science.gov (United States)

Zhang, Xigui; Zheng, Dan; Wang, Tao; Chen, Cong; Cao, Jianyu; Yan, Jian; Wang, Wenming; Liu, Juanying; Liu, Haohan; Tian, Juan; Li, Xinxin; Yang, Hui; Xia, Baojia

The fabrication and performance evaluation of a miniature 6-cell PEMFC stack based on Micro-Electronic-Mechanical-System (MEMS) technology is presented in this paper. The stack with a planar configuration consists of 6-cells in serial interconnection by spot welding one cell anode with another cell cathode. Each cell was made by sandwiching a membrane-electrode-assembly (MEA) between two flow field plates fabricated by a classical MEMS wet etching method using silicon wafer as the original material. The plates were made electrically conductive by sputtering a Ti/Pt/Au composite metal layer on their surfaces. The 6-cells lie in the same plane with a fuel buffer/distributor as their support, which was fabricated by the MEMS silicon-glass bonding technology. A small hydrogen storage canister was used as fuel source. Operating on dry H 2 at a 40 ml min -1 flow rate and air-breathing conditions at room temperature and atmospheric pressure, the linear polarization experiment gave a measured peak power of 0.9 W at 250 mA cm -2 for the stack and average power density of 104 mW cm -2 for each cell. The results suggested that the stack has reasonable performance benefiting from an even fuel supply. But its performance tended to deteriorate with power increase, which became obvious at 600 mW. This suggests that the stack may need some power assistance, from say supercapacitors to maintain its stability when operated at higher power.

Performance of 12Ah aerospace nickel-cadmium cells of design variable groups

Science.gov (United States)

Vasanth, K. L.

1985-01-01

The design variable program of NASA is a systematic approach to evaluate the performance of 12Ah aerospace nickel-cadmium cells of 9 important cell designs. These cells were life cycled in a Low-Earth Orbit (LEO) regime for 3 to 4 years. Representative cells taken from the design variable groups after different cycling periods have been examined. The results show that: (1) positive swelling and carbonate content in the electrolyte increases as a function of the number of cycles, (2) electrolyte distribution follows the order NEG greater than POS greater than SEP, 3) control and no PQ groups outperformed the rest of the groups and (4) the polypropylene group shows very heavy cadmium migration and poor performance.

Preliminary tests of the electrostatic plasma accelerator

Science.gov (United States)

Aston, G.; Acker, T.

1990-01-01

This report describes the results of a program to verify an electrostatic plasma acceleration concept and to identify those parameters most important in optimizing an Electrostatic Plasma Accelerator (EPA) thruster based upon this thrust mechanism. Preliminary performance measurements of thrust, specific impulse and efficiency were obtained using a unique plasma exhaust momentum probe. Reliable EPA thruster operation was achieved using one power supply.

Fe-substituted (La,Sr)TiO{sub 3} as potential electrodes for symmetrical fuel cells (SFCs)

Energy Technology Data Exchange (ETDEWEB)

Canales-Vazquez, Jesus [Renewable Energy Research Institute, University of Castilla la Mancha, 02006 Albacete (Spain); Instituto de Ciencia de los Materiales de Barcelona, ICMAB-CSIC, 01893 Bellaterra (Spain); Ruiz-Morales, Juan Carlos; Marrero-Lopez, David; Pena-Martinez, Juan; Nunez, Pedro [Dpto. Quimica Inorganica, Universidad de La Laguna, Avda. Francisco Sanchez s/n, 38200 Tenerife, Canary Islands (Spain); Gomez-Romero, Pedro [Instituto de Ciencia de los Materiales de Barcelona, ICMAB-CSIC, 01893 Bellaterra (Spain)

2007-09-27

In the work presented herein, the potential use of La{sub 4}Sr{sub 8}Ti{sub 12-x}Fe{sub x}O{sub 38-{delta}} (LSTF) materials as electrodes for a new concept of solid oxide fuel cells, symmetrical fuel cells (SFCs), is considered. Such fuel cells use simultaneously the same material as anode and cathode, which notably simplifies the assembly and further maintenance of the cells. Therefore, we search for materials showing high conductivity in a wide range of oxygen partial pressures in addition to certain degree of catalytic activity for the oxidation of the fuel and reduction of the oxidant, respectively. The preliminary electrochemical experiments performed reveal that the overall conductivity increases notably upon Fe substitution, being the main contribution electronic n-type. The fuel cell tests indicate that LSTF composites with YSZ and CeO{sub 2} perform reasonably well under H{sub 2} conditions, although the performance in methane is rather modest and require further optimisation. (author)

Modeling electrochemical performance in large scale proton exchange membrane fuel cell stacks

Energy Technology Data Exchange (ETDEWEB)

Lee, J H [Los Alamos National Lab., NM (United States); Lalk, T R [Texas A and M Univ., College Station, TX (United States). Dept. of Mechanical Engineering; Appleby, A J [Center for Electrochemical Studies and Hydrogen Research, Texas Engineering Experimentation Station, Texas A and M Univ., College Station, TX (United States)

1998-02-01

The processes, losses, and electrical characteristics of a Membrane-Electrode Assembly (MEA) of a Proton Exchange Membrane Fuel Cell (PEMFC) are described. In addition, a technique for numerically modeling the electrochemical performance of a MEA, developed specifically to be implemented as part of a numerical model of a complete fuel cell stack, is presented. The technique of calculating electrochemical performance was demonstrated by modeling the MEA of a 350 cm{sup 2}, 125 cell PEMFC and combining it with a dynamic fuel cell stack model developed by the authors. Results from the demonstration that pertain to the MEA sub-model are given and described. These include plots of the temperature, pressure, humidity, and oxygen partial pressure distributions for the middle MEA of the modeled stack as well as the corresponding current produced by that MEA. The demonstration showed that models developed using this technique produce results that are reasonable when compared to established performance expectations and experimental results. (orig.)

Preliminary Monthly Climatological Summaries

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Preliminary Local Climatological Data, recorded since 1970 on Weather Burean Form 1030 and then National Weather Service Form F-6. The preliminary climate data pages...

Performance Analysis and Development Strategies for Solid Oxide Fuel Cells

International Nuclear Information System (INIS)

Ivers-Tiffee, E; Leonide, A; Weber, A

2011-01-01

Solid oxide fuel cells (SOFC) are of great interest for a diverse range of applications. Within the past 10 years, an increase in power density by one order of magnitude, a lowering of the operating temperature by 200 K, and degradation rates lowered by a factor of 10 have been achieved on the cell and stack level. However, there is still room for further enhancement of the overall performance by suitably tailoring the cell components on a micro- and nanostructural level. The efficiency of the electrochemically active single cell is characterized by the linear ohmic losses within the electrolyte and by nonlinear polarization losses at the electrode-electrolyte interfaces. Both depend on material composition and operation conditions (temperature and time, fuel utilisation and gas composition). The area-specific resistance (ASR) is considered as the figure of merit for overall performance. ASR values of anode supported cells (ASC) were determined by means of impedance spectroscopy and subsequently separated into ohmic losses (mainly electrolyte) and nonlinear polarisation losses resulting from gas diffusion and activation polarization in the cathode and anode. The efficiencies of ASCs will be discussed for various material combinations in the temperature range of technological interest (between 550 deg. C and 850 deg. C).

Crystallization and preliminary X-ray diffraction analysis of rat autotaxin

International Nuclear Information System (INIS)

Day, Jacqueline E.; Hall, Troii; Pegg, Lyle E.; Benson, Timothy E.; Hausmann, Jens; Kamtekar, Satwik

2010-01-01

Autotaxin (ATX), a pyrophosphatase/phosphodiesterase enzyme, is a promising drug target for many indications and is only distantly related to enzymes of previously determined structure. Here, the cloning, expression, purification, crystallization and preliminary diffraction analysis of ATX are reported. Rat autotaxin has been cloned, expressed, purified to homogeneity and crystallized via hanging-drop vapour diffusion using PEG 3350 as precipitant and ammonium iodide and sodium thiocyanate as salts. The crystals diffracted to a maximum resolution of 2.05 Å and belonged to space group P1, with unit-cell parameters a = 53.8, b = 63.3, c = 70.5 Å, α = 98.8, β = 106.2, γ = 99.8°. Preliminary X-ray diffraction analysis indicated the presence of one molecule per asymmetric unit, with a solvent content of 47%

Preliminary analysis of a 1:4 scale prestressed concrete containment vessel model

International Nuclear Information System (INIS)

Dameron, R.A.; Rashid, Y.R.; Luk, V.K.; Hessheimer, M.F.

1997-01-01

Sandia National Laboratories is conducting a research program to investigate the integrity of nuclear containment structures. As part of the program Sandia will construct an instrumented 1:4 scale model of a prestressed concrete containment vessel (PCCV) for pressurized water reactors (PWR), which will be pressure tested up to its ultimate capacity. One of the key program objectives is to develop validated methods to predict the structural performance of containment vessels when subjected to beyond design basis loadings. Analytical prediction of structural performance requires a stepwise, systematic approach that addresses all potential failure modes. The analysis effort includes two and three-dimensional nonlinear finite element analyses of the PCCV test model to evaluate its structural performance under very high internal pressurization. Such analyses have been performed using the nonlinear concrete constitutive model, ANACAP-U, in conjunction with the ABAQUS general purpose finite element code. The analysis effort is carried out in three phases: preliminary analysis; pretest prediction; and post-test data interpretation and analysis evaluation. The preliminary analysis phase serves to provide instrumentation support and identify candidate failure modes. The associated tasks include the preliminary prediction of failure pressure and probable failure locations and the development of models to be used in the detailed failure analyses. This paper describes the modeling approaches and some of the results obtained in the first phase of the analysis effort

Parallel local search for solving Constraint Problems on the Cell Broadband Engine (Preliminary Results

Directory of Open Access Journals (Sweden)

Salvator Abreu

2009-10-01

Full Text Available We explore the use of the Cell Broadband Engine (Cell/BE for short for combinatorial optimization applications: we present a parallel version of a constraint-based local search algorithm that has been implemented on a multiprocessor BladeCenter machine with twin Cell/BE processors (total of 16 SPUs per blade. This algorithm was chosen because it fits very well the Cell/BE architecture and requires neither shared memory nor communication between processors, while retaining a compact memory footprint. We study the performance on several large optimization benchmarks and show that this achieves mostly linear time speedups, even sometimes super-linear. This is possible because the parallel implementation might explore simultaneously different parts of the search space and therefore converge faster towards the best sub-space and thus towards a solution. Besides getting speedups, the resulting times exhibit a much smaller variance, which benefits applications where a timely reply is critical.

Acrylic acid grafted PDMS preliminary activated by Ar{sup +}beam plasma and cell observation

Energy Technology Data Exchange (ETDEWEB)

Kostadinova, A.; Zaekov, N. [Institute of Biophysics, BAS, Sofia (Bulgaria); Keranov, I. [Department of Polymer Engineering, University of Chemical Technology and Metallurgy (UCTM), Sofia (Bulgaria)

2007-07-01

Plasma based Ar{sup +} beam performed in RF (13.56 MHz) low-pressure (200 mTorr) glow discharge (at 100 W, 1200 W and 2500 W) with a serial capacitance was employed for surface modification of poly(dimethylsiloxane) (PDMS) aimed at improvement of its interactions with living cells. The presence of a serial capacitance ensures arise of an ion-flow inside the plasma volume directed toward the treated sample and the vary of the discharge power ensures varied density of the ion-flow The initial adhesion of human fibroblast cells was studied on the described above plasma based Ar{sup +}beam modified and acrylic acid (AA) grafted or not fibronectin (FN) pre-coated or ba resurfaces. The cell response seem sto be related with the peculiar structure and wettability of the modified PDMS surface layer after plasma based Ar{sup +} beam treatment followed or not by AA grafting. Key words: Biomaterials; Surface treatment of PDMS; Plasma based Ar{sup +} beam; Acrylic acid grafting; Fibroblast cells.

Synthesis and preliminary evaluation of 9-(4-[{sup 18}F]fluoro-3-hydroxymethylbutyl) guanine ([{sup 18}F]FHBG) in HSV1-tk gene transduced hepatoma cell

Energy Technology Data Exchange (ETDEWEB)

Moon, Byung Seok; Lee, Tae Sup [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Lee, Myoung Keun [Yonsei University, Wonju (Korea, Republic of)] (and others)

2006-08-15

The HSV1-tk reporter gene system is the most widely used system because of its advantage that direct monitoring is possible without the introduction of a separate reporter gene in case of HSV1-tk suicide gene therapy. In this study, we investigate the usefulness of the reporter probe (substrate), 9-(4-[{sup 18}F]fluoro-3-hydroxymethylbutyl) guanine ([{sup 18}F]FHBG) for non-invasive reporter gene imaging using PET in HSV1-tk expressing hepatoma model. Radiolabeled FHBG was prepared in 8 steps from a commercially available triester. The labeling reaction was carried out by NCA nucleophilic substitution with K[{sup 18}F]/K2.2.2. in acetonitrile using N2-monomethoxytrityl-9-[4-(tosly)-3-monomethoxytritylmethylbutl] guanine as a precursor, followed by deprotection with 1 N HCI. Preliminary biological properties of the probe were evaluated with MCA cells and MCA-tk cells transduced with HSV1-tk reporter gene. In vitro uptake and release-out studies of [{sup 18}F]FHBG were performed, and was analyzed correlation between [{sup 18}F]FHBG uptake ratio according to increasing numeric count of MCA-tk cells and degree of gene expression. MicroPET scan image was obtained with MCA and MCA-tk tumor beating Balb/c-nude mouse model. [{sup 18}F]FHBG was purified by reverse phase semi-HPLC system and collected at around 16-18 min. Radiochemical yield was about 20-25% (corrected for decay), radiochemical purity was > 95% and specific activity was around > 55.5 GBq/ {mu} mol. Specific accumulation of [{sup 18}F]FHBG was observed in HSV1-tk gene transduced MCA-tk cells but not MCA cells, and consecutive 1 hour release-out results showed more than 86% of uptaked [{sup 18}F]FHBG was retained inside of cells. The uptake of [{sup 18}F]FHBG was showed a highly significant linear correlation (R{sup 2} = 0.995) with increasing percentage of MCA-tk numeric cell count. In microPET scan images, remarkable difference of accumulation was observed for the two type of tumors. [{sup 18}F]FHBG appears

A preliminary assessment of financial stability, efficiency, health systems and health outcomes using performance-based contracts in Belize.

Science.gov (United States)

Bowser, Diana M; Figueroa, Ramon; Natiq, Laila; Okunogbe, Adeyemi

2013-01-01

Over the last 10 years, Belize has implemented a National Health Insurance (NHI) program that uses performance-based contracts with both public and private facilities to improve financial sustainability, efficiency and service provision. Data were collected at the facility, district and national levels in order to assess trends in financial sustainability, efficiency payments, year-end bonuses and health system and health outcomes. A difference-in-difference approach was used to assess the difference in technical efficiency between private and public facilities. The results show that per capita spending on services provided by the NHI program has decreased over the period 2006-2009 from BZ$177 to BZ$136. The private sector has achieved higher levels of technical efficiency, but lower percentages of efficiency and year-end bonus payments. Districts with contracts through the NHI program showed greater improvements in facility births, nurse density, reducing maternal mortality, diabetes deaths and morbidity from bronchitis, emphysema and asthma than districts without contracts over the period 2006-2010. This preliminary assessment of Belize's pay-for-performance system provides some positive results, however further research is needed to use the lessons learned from Belize to implement similar reforms in other systems.

Cloning, expression, purification, crystallization and preliminary X-ray analysis of the pilus-associated sortase C from Streptococcus pneumoniae

International Nuclear Information System (INIS)

Neiers, F.; Madhurantakam, C.; Fälker, S.; Normark, S.; Henriques-Normark, B.; Achour, A.

2008-01-01

Crystallization conditions and preliminary X-ray diffraction analysis of the S. pneumoniae-derived pilus-associated protein sortase C are reported. The pilus-associated sortase C from Streptococcus pneumoniae (SrtC or Srt-2) acts as a polymerase for the pilus subunit proteins RrgA and RrgB. Here, the crystallization and preliminary X-ray diffraction analysis of three crystal forms of SrtC are reported. One crystal form belongs to space group P2 1 2 1 2 1 , with unit-cell parameters a = 48.9, b = 96.9, c = 98.9 Å, α = β = γ = 90°. The other two crystal forms belong to space group P222, with unit-cell parameters a = 48.8, b = 97.2, c = 99.2 Å, α = β = γ = 90° and a = 48.6, b = 96.5, c = 98.8 Å, α = β = γ = 90°, respectively. Preliminary analysis indicates the presence of two molecules in the asymmetric unit of the crystal for all three forms

The Effects of Nonuniform Illumination on the Electrical Performance of a Single Conventional Photovoltaic Cell

Directory of Open Access Journals (Sweden)

Damasen Ikwaba Paul

2015-01-01

Full Text Available Photovoltaic (PV concentrators are a promising approach for lowering PV electricity costs in the near future. However, most of the concentrators that are currently used for PV applications yield nonuniform flux profiles on the surface of a PV module which in turn reduces its electrical performance if the cells are serially connected. One way of overcoming this effect is the use of PV modules with isolated cells so that each cell generates current that is proportional to the energy flux absorbed. However, there are some cases where nonuniform illumination also exists in a single cell in an isolated cells PV module. This paper systematically studied the effect of nonuniform illumination on various cell performance parameters of a single monocrystalline standard PV cell at low and medium energy concentration ratios. Furthermore, the effect of orientation, size, and geometrical shapes of nonuniform illumination was also investigated. It was found that the effect of nonuniform illumination on various PV cell performance parameters of a single standard PV cell becomes noticeable at medium energy flux concentration whilst the location, size, and geometrical shape of nonuniform illumination have no effect on the performance parameters of the cell.

High-performance polymer photovoltaic cells and photodetectors

Science.gov (United States)

Yu, Gang; Srdanov, Gordana; Wang, Hailiang; Cao, Yong; Heeger, Alan J.

2001-02-01

Polymer photovoltaic cells and photodetectors have passed their infancy and become mature technologies. The energy conversion efficiency of polymer photovoltaic cells have been improved to over 4.1% (500 nm, 10 mW/cm2). Such high efficiency polymer photovoltaic cells are promising for many applications including e-papers, e-books and smart- windows. The development of polymer photodetectors is even faster. The performance parameters have been improved to the level meeting all specifications for practical applications. The polymer photodetectors are of high photosensitivity (approximately 0.2 - 0.3 A/Watt in visible and UV), low dark current (0.1 - 1 nA/cm2), large dynamic range (> 8 orders of magnitude), linear intensity dependence, low noise level and fast response time (to nanosecond time domain). These devices show long shelf and operation lives. The advantages of low manufacturing cost, large detection area, and easy hybridization and integration with other electronic or optical components make the polymer photodetectors promising for a variety of applications including chemical/biomedical analysis, full-color digital image sensing and high energy radiation detection.

Preliminary AD-Horn Thermomechanical and Electrodynamic Simulations

CERN Document Server

AUTHOR|(CDS)2095747; Horvath, David; Calviani, Marco

2016-01-01

As part of the Antiproton Decelerator (AD) target area consolidation activities planned for LS2, it has been necessary to perform a comprehensive study of the thermo-structural behaviour of the AD magnetic horn during operation, in order to detail specific requirements for the upgrade projects and testing procedures. The present work illustrates the preliminary results of the finite element analysis carried out to evaluate the thermal and structural behaviour of the device, as well as the methodology used to model and solve the thermomechanical and electrodynamic simulations performed in the AD magnetic horn.

A preliminary conceptual design study for Korean fusion DEMO reactor

Energy Technology Data Exchange (ETDEWEB)

Kim, Keeman, E-mail: kkeeman@nfri.re.kr [National Fusion Research Institute, 169-148 Gwahak-ro, Daejeon 305-806 (Korea, Republic of); Kim, Hyoung Chan; Oh, Sangjun; Lee, Young Seok; Yeom, Jun Ho; Im, Kihak; Lee, Gyung-Su [National Fusion Research Institute, 169-148 Gwahak-ro, Daejeon 305-806 (Korea, Republic of); Neilson, George; Kessel, Charles; Brown, Thomas; Titus, Peter [Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543 (United States)

2013-10-15

Highlights: ► Perform a preliminary conceptual study for a steady-state Korean DEMO reactor. ► Present design guidelines and requirements of Korean DEMO reactor. ► Present a preliminary design of TF (toroidal field) and CS (central solenoid) magnet. ► Present a preliminary result of the radial build scheme of Korean DEMO reactor. -- Abstract: As the ITER is being constructed, there is a growing anticipation for an earlier realization of fusion energy, so called fast-track approach. Korean strategy for fusion energy can be regarded as a fast-track approach and one special concept discussed in this paper is a two-stage development plan. At first, a steady-state Korean DEMO Reactor (K-DEMO) is designed not only to demonstrate a net electricity generation and a self-sustained tritium cycle, but also to be used as a component test facility. Then, at its second stage, a major upgrade is carried out by replacing in-vessel components in order to show a net electric generation on the order of 300 MWe and the competitiveness in cost of electricity (COE). The major radius is designed to be just below 6.5 m, considering practical engineering feasibilities. By using high performance Nb{sub 3}Sn-based superconducting cable currently available, high magnetic field at the plasma center above 8 T can be achieved. A design concept for TF magnets and radial builds for the K-DEMO considering a vertical maintenance scheme, are presented together with preliminary design parameters.

Preliminary Seismic Response and Fragility Analysis for DACS Cabinet

Energy Technology Data Exchange (ETDEWEB)

Oh, Jinho; Kwag, Shinyoung; Lee, Jongmin; Kim, Youngki [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-05-15

A DACS cabinet is installed in the main control room. The objective of this paper is to perform seismic analyses and evaluate the preliminary structural integrity and seismic capacity of the DACS cabinet. For this purpose, a 3-D finite element model of the DACS cabinet was developed and its modal analyses are carried out to analyze the dynamic characteristics. The response spectrum analyses and the related safety evaluation are then performed for the DACS cabinet subject to seismic loads. Finally, the seismic margin and seismic fragility of the DACS cabinet are investigated. A seismic analysis and preliminary structural integrity of the DACS cabinet under self weight and SSE load have been evaluated. For this purpose, 3-D finite element models of the DACS cabinet were developed. A modal analysis, response spectrum analysis, and seismic fragility analysis were then performed. From the structural analysis results, the DACS cabinet is below the structural design limit of under SSE 0.3g, and can structurally withstand until less than SSE 3g based on an evaluation of the maximum effective stresses. The HCLPF capacity for the DGRS of the SSE 0.3g is 0.55g. A modal analysis, response spectrum analysis, and seismic fragility analysis were then performed. From the structural analysis results, the DACS cabinet is below the structural design limit of under SSE 0.3g, and can structurally withstand until less than SSE 3g based on an evaluation of the maximum effective stresses. The HCLPF capacity for the DGRS of the SSE 0.3g is 0.55g. Therefore, it is concluded that the DACS cabinet was safely designed in that no damage to the preliminary structural integrity and sufficient seismic margin is expected.

Preliminary Seismic Response and Fragility Analysis for DACS Cabinet

International Nuclear Information System (INIS)

Oh, Jinho; Kwag, Shinyoung; Lee, Jongmin; Kim, Youngki

2013-01-01

A DACS cabinet is installed in the main control room. The objective of this paper is to perform seismic analyses and evaluate the preliminary structural integrity and seismic capacity of the DACS cabinet. For this purpose, a 3-D finite element model of the DACS cabinet was developed and its modal analyses are carried out to analyze the dynamic characteristics. The response spectrum analyses and the related safety evaluation are then performed for the DACS cabinet subject to seismic loads. Finally, the seismic margin and seismic fragility of the DACS cabinet are investigated. A seismic analysis and preliminary structural integrity of the DACS cabinet under self weight and SSE load have been evaluated. For this purpose, 3-D finite element models of the DACS cabinet were developed. A modal analysis, response spectrum analysis, and seismic fragility analysis were then performed. From the structural analysis results, the DACS cabinet is below the structural design limit of under SSE 0.3g, and can structurally withstand until less than SSE 3g based on an evaluation of the maximum effective stresses. The HCLPF capacity for the DGRS of the SSE 0.3g is 0.55g. A modal analysis, response spectrum analysis, and seismic fragility analysis were then performed. From the structural analysis results, the DACS cabinet is below the structural design limit of under SSE 0.3g, and can structurally withstand until less than SSE 3g based on an evaluation of the maximum effective stresses. The HCLPF capacity for the DGRS of the SSE 0.3g is 0.55g. Therefore, it is concluded that the DACS cabinet was safely designed in that no damage to the preliminary structural integrity and sufficient seismic margin is expected

Performance of 500 m3 TankCell® at Kevitsa Cu-Ni-PGM concentrator

Directory of Open Access Journals (Sweden)

Mattsson Toni

2016-01-01

Full Text Available Outotec TankCell e500 flotation cell, with 500 m3 of efficient flotation volume, has been in operation since October 2014 at Kevitsa Cu-Ni-PGM concentrator as the first Cu rougher flotation cell. The 500 m3 flotation cell has proven to provide metallurgical superiority at very low specific power. On average the cell has recovered 71% of copper contained in the flotation feed. The cell has produced the concentrate with the Cu grade equal to 17% Cu. The typical specific power for the cell is around 0.4 kW/m3 (blower power not included. After the start-up of the cell the operating parameters have varied. The mixing speed have varied from 4.9 to 7.0 m/s and the superficial gas velocity from 0.3 to 1.5 cm/s. At various operating parameters the mixing, gas dispersion and metallurgical performance of the cell have been evaluated. In this paper a review of the hydrodynamic and metallurgical performance of the cell is presented. The paper focuses on the interactions of mixing intensity, bubble size and metallurgical performance in industrial application.

A review on the performance and modelling of proton exchange membrane fuel cells

Energy Technology Data Exchange (ETDEWEB)

Boucetta, A., E-mail: abirboucetta@yahoo.fr; Ghodbane, H., E-mail: h.ghodbane@mselab.org; Bahri, M., E-mail: m.bahri@mselab.org [Department of Electrical Engineering, MSE Laboratory, Mohamed khider Biskra University (Algeria); Ayad, M. Y., E-mail: ayadmy@gmail.com [R& D, Industrial Hybrid Vehicle Applications (France)

2016-07-25

Proton Exchange Membrane Fuel Cells (PEMFC), are energy efficient and environmentally friendly alternative to conventional energy conversion for various applications in stationary power plants, portable power device and transportation. PEM fuel cells provide low operating temperature and high-energy efficiency with near zero emission. A PEM fuel cell is a multiple distinct parts device and a series of mass, energy, transport through gas channels, electric current transport through membrane electrode assembly and electrochemical reactions at the triple-phase boundaries. These processes play a decisive role in determining the performance of the Fuel cell, so that studies on the phenomena of gas flows and the performance modelling are made deeply. This paper gives a comprehensive overview of the state of the art on the Study of the phenomena of gas flow and performance modelling of PEMFC.

Influence of Boundary Conditions on the Simulation of a Diamond-Type Lattice Structure: A Preliminary Study

Directory of Open Access Journals (Sweden)

Patrick Terriault

2017-01-01

Full Text Available Emergent additive manufacturing processes allow the use of metallic porous structures in various industrial applications. Because these structures comprise a large number of ordered unit cells, their design using conventional modeling approaches, such as finite elements, becomes a real challenge. A homogenization technique, in which the lattice structure is simulated as a fully dense volume having equivalent material properties, can then be employed. To determine these equivalent material properties, numerical simulations can be performed on a single unit cell of the lattice structure. However, a critical aspect to consider is the boundary conditions applied to the external faces of the unit cell. In the literature, different types of boundary conditions are used, but a comparative study is definitely lacking. In this publication, a diamond-type unit cell is studied in compression by applying different boundary conditions. If the porous structure’s boundaries are free to deform, then the periodic boundary condition is found to be the most representative, but constraint equations must be introduced in the model. If, instead, the porous structure is inserted in a rigid enclosure, it is then better to use frictionless boundary conditions. These preliminary results remain to be validated for other types of unit cells loaded beyond the yield limit of the material.

State performance in pluripotent and adult stem cell research, 2009-2016.

Science.gov (United States)

Surani, Sana H; Levine, Aaron D

2018-04-01

To examine how the geographic distribution of pluripotent and adult stem cell research publications within the USA differs from other areas of biomedical research. Publication count data for pluripotent stem cell research, adult stem cell research and a comparison group representative of biomedical research more broadly were collected and analyzed for each US state from 2009 to 2016. The distribution of pluripotent stem cell research differed from the other fields with overperformance in pluripotent stem cell research observed in California, as well as Wisconsin, Massachusetts, Maryland and Connecticut. Our analysis suggests that permissive state stem cell policy may be one of the several factors contributing to strong state performance in pluripotent stem cell research.

“Imaging” LEIS of micro-patterned solid oxide fuel cell electrodes

Energy Technology Data Exchange (ETDEWEB)

Druce, John, E-mail: john.druce@i2cner.kyushu-u.ac.jp [International Institute for Carbon Neutral Energy Research (wpi-I2CNER), Kyushu University, Fukuoka 819-0395 (Japan); Simrick, Neil [Department of Materials, Imperial College London, London SW7 2BP (United Kingdom); Ishihara, Tatsumi [International Institute for Carbon Neutral Energy Research (wpi-I2CNER), Kyushu University, Fukuoka 819-0395 (Japan); Kilner, John [International Institute for Carbon Neutral Energy Research (wpi-I2CNER), Kyushu University, Fukuoka 819-0395 (Japan); Department of Materials, Imperial College London, London SW7 2BP (United Kingdom)

2014-08-01

Understanding the kinetics of oxygen exchange between the gas phase and a ceramic electrode is key to optimising the performance of electrochemical energy conversion devices such as Solid Oxide Fuel Cells. Clearly the surface chemistry of these materials is important, and surface sensitive techniques such as Low Energy Ion Scattering (LEIS) can provide important compositional information key to unravelling electrode kinetics. In this work, we use high lateral resolution LEIS to perform local analyses of a micropatterned electrode structure, of the type often used for studies of the geometrical dependences of electrode performance. We find that the results are comparable to those for bulk materials, but detect evidence of cation interdiffusion from the electrode to the electrolyte. Finally, we note that this preliminary study could open the prospect of in situ measurements of cells near operating conditions.

Preliminary 19F-MRS Study of Tumor Cell Proliferation with 3′-deoxy-3′-fluorothymidine and Its Metabolite (FLT-MP

Directory of Open Access Journals (Sweden)

In Ok Ko

2017-01-01

Full Text Available The thymidine analogue 3′-deoxy-3′-[18F]fluorothymidine, or [18F]fluorothymidine ([18F]FLT, is used to measure tumor cell proliferation with positron emission tomography (PET imaging technology in nuclear medicine. FLT is phosphorylated by thymidine kinase 1 (TK1 and then trapped inside cells; it is not incorporated into DNA. Imaging with 18F-radiolabeled FLT is a noninvasive technique to visualize cellular proliferation in tumors. However, it is difficult to distinguish between [18F]FLT and its metabolites by PET imaging, and quantification has not been attempted using current imaging methods. In this study, we successfully acquired in vivo F19 spectra of natural or nonradioactive 3′-deoxy-3′-fluorothymidine ([19F]FLT and its monophosphate metabolite (FLT-MP in a tumor xenograft mouse model using 9.4T magnetic resonance imaging (MRI. This preliminary result demonstrates that 19F magnetic resonance spectroscopy (MRS with FLT is suitable for the in vivo assessment of tumor aggressiveness and for early prediction of treatment response.

Application of biocathode in microbial fuel cells: cell performance and microbial community

Energy Technology Data Exchange (ETDEWEB)

Guo-Wei, Chen [Pusan National Univ. (Korea). Dept. of Environmental Engineering; Hefei Univ. of Technology (China). School of Civil Engineering; Choi, Soo-Jung; Lee, Tae-Ho; Lee, Gil-Young; Cha, Jae-Hwan; Kim, Chang-Won [Pusan National Univ. (Korea). Dept. of Environmental Engineering

2008-06-15

Instead of the utilization of artificial redox mediators or other catalysts, a biocathode has been applied in a two-chamber microbial fuel cell in this study, and the cell performance and microbial community were analyzed. After a 2-month startup, the microorganisms of each compartment in microbial fuel cell were well developed, and the output of microbial fuel cell increased and became stable gradually, in terms of electricity generation. At 20 ml/min flow rate of the cathodic influent, the maximum power density reached 19.53 W/m{sup 3}, while the corresponding current and cell voltage were 15.36 mA and 223 mV at an external resistor of 14.9 {omega}, respectively. With the development of microorganisms in both compartments, the internal resistance decreased from initial 40.2 to 14.0 {omega}, too. Microbial community analysis demonstrated that five major groups of the clones were categorized among those 26 clone types derived from the cathode microorganisms. Betaproteobacteria was the most abundant division with 50.0% (37 of 74) of the sequenced clones in the cathode compartment, followed by 21.6% (16 of 74) Bacteroidetes, 9.5% (7 of 74) Alphaproteobacteria, 8.1% (6 of 74) Chlorobi, 4.1% (3 of 74) Deltaproteobacteria, 4.1% (3 of 74) Actinobacteria, and 2.6% (2 of 74) Gammaproteobacteria. (orig.)

Fabrication of preliminary fuel rods for SFR

International Nuclear Information System (INIS)

Kim, Sun Ki; Oh, Seok Jin; Ko, Young Mo; Woo, Youn Myung; Kim, Ki Hwan

2012-01-01

Metal fuels was selected for fueling many of the first reactors in the US, including the Experimental Breeder Reactor-I (EBR-I) and the Experimental Breeder Reactor-II (EBR-II) in Idaho, the FERMI-I reactor, and the Dounreay Fast Reactor (DFR) in the UK. Metallic U.Pu.Zr alloys were the reference fuel for the US Integral Fast Reactor (IFR) program. Metallic fuel has advantages such as simple fabrication procedures, good neutron economy, high thermal conductivity, excellent compatibility with a Na coolant and inherent passive safety. U-Zr-Pu alloy fuels have been used for SFR (sodium-cooled fast reactor) related to the closed fuel cycle for managing minor actinides and reducing a high radioactivity levels since the 1980s. Fabrication technology of metallic fuel for SFR has been in development in Korea as a national nuclear R and D program since 2007. For the final goal of SFR fuel rod fabrication with good performance, recently, three preliminary fuel rods were fabricated. In this paper, the preliminary fuel rods were fabricated, and then the inspection for QC(quality control) of the fuel rods was performed

Introducing catalyst in alkaline membrane for improved performance direct borohydride fuel cells

Science.gov (United States)

Qin, Haiying; Lin, Longxia; Chu, Wen; Jiang, Wei; He, Yan; Shi, Qiao; Deng, Yonghong; Ji, Zhenguo; Liu, Jiabin; Tao, Shanwen

2018-01-01

A catalytic material is introduced into the polymer matrix to prepare a novel polymeric alkaline electrolyte membrane (AEM) which simultaneously increases ionic conductivity, reduces the fuel cross-over. In this work, the hydroxide anion exchange membrane is mainly composed of poly(vinylalcohol) and alkaline exchange resin. CoCl2 is added into the poly(vinylalcohol) and alkaline exchange resin gel before casting the membrane to introduce catalytic materials. CoCl2 is converted into CoOOH after the reaction with KOH solution. The crystallinity of the polymer matrix decreases and the ionic conductivity of the composite membrane is notably improved by the introduction of Co-species. A direct borohydride fuel cell using the composite membrane exhibits an open circuit voltage of 1.11 V at 30 °C, which is notably higher than that of cells using other AEMs. The cell using the composite membrane achieves a maximum power density of 283 mW cm-2 at 60 °C while the cell using the membrane without Co-species only reaches 117 mW cm-2 at the same conditions. The outstanding performance of the cell using the composite membrane benefits from impregnation of the catalytic Co-species in the membrane, which not only increases the ionic conductivity but also reduces electrode polarization thus improves the fuel cell performance. This work provides a new approach to develop high-performance fuel cells through adding catalysts in the electrolyte membrane.

Solid lipid nanoparticles by coacervation loaded with a methotrexate prodrug: preliminary study for glioma treatment.

Science.gov (United States)

Battaglia, Luigi; Muntoni, Elisabetta; Chirio, Daniela; Peira, Elena; Annovazzi, Laura; Schiffer, Davide; Mellai, Marta; Riganti, Chiara; Salaroglio, Iris Chiara; Lanotte, Michele; Panciani, Pierpaolo; Capucchio, Maria Teresa; Valazza, Alberto; Biasibetti, Elena; Gallarate, Marina

2017-03-01

Methotrexate-loaded biocompatible nanoparticles were tested for preliminary efficacy in glioma treatment. Behenic acid nanoparticles, prepared by the coacervation method, were loaded with the ester prodrug didodecylmethotrexate, which was previously tested in vitro against glioblastoma human primary cultures. Nanoparticle conjugation with an ApoE mimicking chimera peptide was performed to obtain active targeting to the brain. Biodistribution studies in healthy rats assessed the superiority of ApoE-conjugated formulation, which was tested on an F98/Fischer glioma model. Differences were observed in tumor growth rate (measured by MRI) between control and treated rats. In vitro tests on F98 cultured cells assessed their susceptibility to treatment, with consequent apoptosis, and allowed us to explain the apoptosis observed in glioma models.

Improving the photovoltaic performance of perovskite solar cells with acetate

Science.gov (United States)

Zhao, Qian; Li, G. R.; Song, Jian; Zhao, Yulong; Qiang, Yinghuai; Gao, X. P.

2016-01-01

In an all-solid-state perovskite solar cell, methylammonium lead halide film is in charge of generating photo-excited electrons, thus its quality can directly influence the final photovoltaic performance of the solar cell. This paper accentuates a very simple chemical approach to improving the quality of a perovskite film with a suitable amount of acetic acid. With introduction of acetate ions, a homogeneous, continual and hole-free perovskite film comprised of high-crystallinity grains is obtained. UV-visible spectra, steady-state and time-resolved photoluminescence (PL) spectra reveal that the obtained perovskite film under the optimized conditions shows a higher light absorption, more efficient electron transport, and faster electron extraction to the adjoining electron transport layer. The features result in the optimized perovskite film can provide an improved short-circuit current. The corresponding solar cells with a planar configuration achieves an improved power conversion efficiency of 13.80%, and the highest power conversion efficiency in the photovoltaic measurements is up to 14.71%. The results not only provide a simple approach to optimizing perovskite films but also present a novel angle of view on fabricating high-performance perovskite solar cells. PMID:27934924

Improving the photovoltaic performance of perovskite solar cells with acetate.

Science.gov (United States)

Zhao, Qian; Li, G R; Song, Jian; Zhao, Yulong; Qiang, Yinghuai; Gao, X P

2016-12-09

In an all-solid-state perovskite solar cell, methylammonium lead halide film is in charge of generating photo-excited electrons, thus its quality can directly influence the final photovoltaic performance of the solar cell. This paper accentuates a very simple chemical approach to improving the quality of a perovskite film with a suitable amount of acetic acid. With introduction of acetate ions, a homogeneous, continual and hole-free perovskite film comprised of high-crystallinity grains is obtained. UV-visible spectra, steady-state and time-resolved photoluminescence (PL) spectra reveal that the obtained perovskite film under the optimized conditions shows a higher light absorption, more efficient electron transport, and faster electron extraction to the adjoining electron transport layer. The features result in the optimized perovskite film can provide an improved short-circuit current. The corresponding solar cells with a planar configuration achieves an improved power conversion efficiency of 13.80%, and the highest power conversion efficiency in the photovoltaic measurements is up to 14.71%. The results not only provide a simple approach to optimizing perovskite films but also present a novel angle of view on fabricating high-performance perovskite solar cells.

Performance of molten carbonate fuel cells with the electrolyte molded at low pressure (IV). Analysis of performance decay factors in MCFC stack

Energy Technology Data Exchange (ETDEWEB)

Sonai, Atuo; Ozu, Hideyuki; Murata, Kenji; Shirogami, Tamotsu; Watanabe, Takao; Izaki, Yoshiyuki; Horiuchi, Nagayuki

1987-09-01

A 1500-h performance test on a 30 x 30 cm cell stack of 10 molten carbonate fuel cells was performed to evaluate the durability of the stack. Beyond 1000 h, decay of its performance was observed. The result of the study for the cause of the decay is reported. The structures of the single cell and stack are introduced. The effective area of the electrode is 530 m/sup 2/. After 1020 h use, the output voltage decreased. Analysis of the cell characteristics and post-test analysis were performed to study the cause of the decrease. It was found that the main cause for the voltage loss would be the occurrence of slight short circuiting between the edge-seal areas via a corrosion product. However, little transfer of lithium and potassium ions was observed through the manifold seal which had been regarded as the main cause for the decay of stacked cells. It was assumed that this was due to the employment of a sealing material which contained glass of low manifold ion conductivity. (10 figs, 4 refs)

Understanding InP Nanowire Array Solar Cell Performance by Nanoprobe-Enabled Single Nanowire Measurements.

Science.gov (United States)

Otnes, Gaute; Barrigón, Enrique; Sundvall, Christian; Svensson, K Erik; Heurlin, Magnus; Siefer, Gerald; Samuelson, Lars; Åberg, Ingvar; Borgström, Magnus T

2018-05-09

III-V solar cells in the nanowire geometry might hold significant synthesis-cost and device-design advantages as compared to thin films and have shown impressive performance improvements in recent years. To continue this development there is a need for characterization techniques giving quick and reliable feedback for growth development. Further, characterization techniques which can improve understanding of the link between nanowire growth conditions, subsequent processing, and solar cell performance are desired. Here, we present the use of a nanoprobe system inside a scanning electron microscope to efficiently contact single nanowires and characterize them in terms of key parameters for solar cell performance. Specifically, we study single as-grown InP nanowires and use electron beam induced current characterization to understand the charge carrier collection properties, and dark current-voltage characteristics to understand the diode recombination characteristics. By correlating the single nanowire measurements to performance of fully processed nanowire array solar cells, we identify how the performance limiting parameters are related to growth and/or processing conditions. We use this understanding to achieve a more than 7-fold improvement in efficiency of our InP nanowire solar cells, grown from a different seed particle pattern than previously reported from our group. The best cell shows a certified efficiency of 15.0%; the highest reported value for a bottom-up synthesized InP nanowire solar cell. We believe the presented approach have significant potential to speed-up the development of nanowire solar cells, as well as other nanowire-based electronic/optoelectronic devices.

Atmospheric effects on the photovoltaic performance of hybrid perovskite solar cells

KAUST Repository

Sheikh, Arif D.

2015-06-01

Organometal trihalide perovskite solar cells have recently attracted lots of attention in the photovoltaic community due to their escalating efficiency and solution processability. The most efficient organometallic mixed-halide sensitized solar cells often employ 2,2′7,7′-tetrakis-(N,N-di-p-methoxyphenyl-amine)-9,9′-spirobifluorene (spiro-MeOTAD) as the hole-transporting material. In this work, we investigated the effect of different atmospheric storage conditions, particularly vacuum, dry nitrogen, and dry air, on the photovoltaic performance of TiO2-CH3NH3PbI3-xClx-spiro-MeOTAD solar cells. We found that spin coating of spiro-MeOTAD in an oxygen atmosphere alone was not adequate to functionalize its hole-transport property completely, and our systematic experiments revealed that the device efficiency depends on the ambient atmospheric conditions during the drying process of spiro-MeOTAD. Complementary incident photon to current conversion efficiency (IPCE), light absorption and photoluminescence quenching measurements allowed us to attribute the atmosphere-dependent efficiency to the improved electronic characteristics of the solar cells. Furthermore, our Fourier transform infrared and electrical impedance measurements unambiguously detected modifications in the spiro-MeOTAD after the drying processes in different gas environments. Our findings demonstrate that proper oxidization and p-doping in functionalizing spiro-MeOTAD play a very critical role in determining device performance. These findings will facilitate the search for alternative hole-transporting materials in high-performance perovskite solar cells with long-term stability.

Expression, purification and preliminary X-ray diffraction studies of the transcriptional factor PyrR from Bacillus halodurans

Energy Technology Data Exchange (ETDEWEB)

Arreola, Rodrigo [Departamento de Bioquímica, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Apartado Postal 70-243, Mexico City 04510 (Mexico); Vega-Miranda, Anita [Instituto Nacional de Enfermedades Respiratorias, Calzada de Tlalpan 4502, México DF 14080 (Mexico); Gómez-Puyou, Armando; Pérez-Montfort, Ruy [Departamento de Bioquímica, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Apartado Postal 70-243, Mexico City 04510 (Mexico); Merino-Pérez, Enrique [Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apartado Postal 510-3, Cuernavaca, Morelos (Mexico); Torres-Larios, Alfredo, E-mail: torres@ifc.unam.mx [Departamento de Bioquímica, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Apartado Postal 70-243, Mexico City 04510 (Mexico)

2008-08-01

The gene-regulation factor PyrR from B. halodurans has been crystallized in two crystal forms. Preliminary crystallographic analysis showed that the protein forms tetramers in both space groups. The PyrR transcriptional regulator is widely distributed in bacteria. This RNA-binding protein is involved in the control of genes involved in pyrimidine biosynthesis, in which uridyl and guanyl nucleotides function as effectors. Here, the crystallization and preliminary X-ray diffraction analysis of two crystal forms of Bacillus halodurans PyrR are reported. One of the forms belongs to the monoclinic space group P2{sub 1} with unit-cell parameters a = 59.7, b = 87.4, c = 72.1 Å, β = 104.4°, while the other form belongs to the orthorhombic space group P22{sub 1}2{sub 1} with unit-cell parameters a = 72.7, b = 95.9, c = 177.1 Å. Preliminary X-ray diffraction data analysis and molecular-replacement solution revealed the presence of four and six monomers per asymmetric unit; a crystallographic tetramer is formed in both forms.

Expression, purification and preliminary X-ray diffraction studies of the transcriptional factor PyrR from Bacillus halodurans

International Nuclear Information System (INIS)

Arreola, Rodrigo; Vega-Miranda, Anita; Gómez-Puyou, Armando; Pérez-Montfort, Ruy; Merino-Pérez, Enrique; Torres-Larios, Alfredo

2008-01-01

The gene-regulation factor PyrR from B. halodurans has been crystallized in two crystal forms. Preliminary crystallographic analysis showed that the protein forms tetramers in both space groups. The PyrR transcriptional regulator is widely distributed in bacteria. This RNA-binding protein is involved in the control of genes involved in pyrimidine biosynthesis, in which uridyl and guanyl nucleotides function as effectors. Here, the crystallization and preliminary X-ray diffraction analysis of two crystal forms of Bacillus halodurans PyrR are reported. One of the forms belongs to the monoclinic space group P2 1 with unit-cell parameters a = 59.7, b = 87.4, c = 72.1 Å, β = 104.4°, while the other form belongs to the orthorhombic space group P22 1 2 1 with unit-cell parameters a = 72.7, b = 95.9, c = 177.1 Å. Preliminary X-ray diffraction data analysis and molecular-replacement solution revealed the presence of four and six monomers per asymmetric unit; a crystallographic tetramer is formed in both forms

Pathology of gastric lesions in donkeys: A preliminary study.

Science.gov (United States)

Al-Mokaddem, A K; Ahmed, K A; Doghaim, R E

2015-11-01

Donkeys (Equus africanus asinus) are important working animals, particularly in countries where the majority of the population lives below the poverty line. Gastric ulceration has been shown to be common in British donkeys but donkeys from other parts of the world have not been as extensively researched. This study was performed as a preliminary overview of the severity and distribution of gastric lesions in mature donkeys and to document which parasites were present. Descriptive study of pathological findings. Stomachs of 35 mature draught donkeys were examined grossly and histopathology samples taken from 5 regions of the gastric mucosa. Gross examination revealed hyperaemia, oedema, erosions and ulcers in addition to parasitic lesions. Histopathological examination revealed hyperkeratosis, acanthosis, vacuolar degeneration of stratified squamous cells, gastritis, erosions, ulcerations, scarring, hyperactivity of mucus glands, periglandular fibroplasia and parasitic granulomes with infestation by Gasterophilus spp. larvae, Habronema spp. and Draschia megastoma. In donkeys, ulceration of the nonglandular regions of the stomach is more prominent than the glandular regions and parasitic infestations were frequent. © 2014 EVJ Ltd.

Preliminary risk assessments of the small HTGR

International Nuclear Information System (INIS)

Everline, C.J.; Bellis, E.A.

1985-05-01

Preliminary investment and safety risk assessments were performed for a preconceptual design of a four-module 250-MW(t) side-by-side steel-vessel pebble bed HTGR plant. Broad event spectra were analyzed involving component damage resulting in unscheduled plant outages and fission product releases resulting in offsite doses. The preliminary assessment indicates at this stage of the design that two categories of events govern the investment risk envelope: primary coolant leaks which release some circulating and plate-out activity that contaminates the confinement and turbogenerator damage which involves extensive turbine blade failure. Primary coolant leaks are important contributors because associated cleanup and decontamination requirements result in longer outages that arise from other events with comparable frequencies. Turbogenerator damage is the salient low-frequency investment risk accident due to the relatively long outages being experienced in the industry. Thermal transients are unimportant investment risk contributors because pressurized core heatups cause little damage, and depressurized core heatups occur at negligible frequencies relative to the forced outage goal. These preliminary results demonstrate investment and safety risk goal compliance at this stage in the design process. Studies are continuing in order to provide valuable insights into risk-significant events to assure a balanced approach to meeting user and regulatory requirements

Impact of temperature on performance of series and parallel connected mono-crystalline silicon solar cells

Directory of Open Access Journals (Sweden)

Subhash Chander

2015-11-01

Full Text Available This paper presents a study on impact of temperature on the performance of series and parallel connected mono-crystalline silicon (mono-Si solar cell employing solar simulator. The experiment was carried out at constant light intensity 550 W/m2with cell temperature in the range 25–60 oC for single, series and parallel connected mono-Si solar cells. The performance parameters like open circuit voltage, maximum power, fill factor and efficiency are found to decrease with cell temperature while the short circuit current is observed to increase. The experimental results reveal that silicon solar cells connected in series and parallel combinations follow the Kirchhoff’s laws and the temperature has a significant effect on the performance parameters of solar cell.

OMEGA Upgrade preliminary design

International Nuclear Information System (INIS)

Craxton, R.S.

1989-10-01

The OMEGA laser system at the Laboratory for Laser Energetics of the University of Rochester is the only major facility in the United States capable of conducting fully diagnosed, direct-drive, spherical implosion experiments. As such, it serves as the national Laser Users Facility, benefiting scientists throughout the country. The University's participation in the National Inertial Confinement Fusion (ICF) program underwent review by a group of experts under the auspices of the National Academy of Sciences (the Happer Committee) in 1985. The Happer Committee recommended that the OMEGA laser be upgraded in energy to 30 kJ. To this end, Congress appropriated $4,000,000 for the preliminary design of the OMEGA Upgrade, spread across FY88 and FY89. This document describes the preliminary design of the OMEGA Upgrade. The proposed enhancements to the existing OMEGA facility will result in a 30-kHJ, 351-nm, 60-beam direct-drive system, with a versatile pulse-shaping facility and a 1%--2% uniformity of target drive. The Upgrade will allow scientists to explore the ignition-scaling regime, and to study target behavior that is hydrodynamically equivalent to that of targets appropriate for a laboratory microfusion facility (LMF). In addition, it will be possible to perform critical interaction experiments with large-scale-length uniformly irradiated plasmas

Preliminary Disposal Analysis for Selected Accelerator Production of Tritium Waste Streams

International Nuclear Information System (INIS)

Ades, M.J.; England, J.L.

1998-06-01

A preliminary analysis was performed for two selected Accelerator Production of Tritium (APT) generated mixed and low-level waste streams to determine if one mixed low-level waste (MLLW) stream that includes the Mixed Waste Lead (MWL) can be disposed of at the Nevada Test Site (NTS) and at the Hanford Site and if one low-level radioactive waste (LLW) stream, that includes the Tungsten waste stream (TWS) generated by the Tungsten Neutron Source modules and used in the Target/Blanket cavity vessel, can be disposed of in the LLW Vaults at the Savannah River Plant (SRP). The preliminary disposal analysis that the radionuclide concentrations of the two selected APT waste streams are not in full compliance with the Waste Acceptance Criteria (WAC) and the Performance Assessment (PA) radionuclide limits of the disposal sites considered

Preliminary Analysis of Google+'s Privacy

OpenAIRE

Mahmood, Shah; Desmedt, Yvo

2011-01-01

In this paper we provide a preliminary analysis of Google+ privacy. We identified that Google+ shares photo metadata with users who can access the photograph and discuss its potential impact on privacy. We also identified that Google+ encourages the provision of other names including maiden name, which may help criminals performing identity theft. We show that Facebook lists are a superset of Google+ circles, both functionally and logically, even though Google+ provides a better user interfac...

Preliminary Studies on the Use of Natural Fibers in Sustainable Concrete

International Nuclear Information System (INIS)

Awad, E.; Mabsout, M.; Hamad, B.; Khatib, H.

2011-01-01

The paper reports on preliminary tests performed to produce a sustainable 'green' concrete material using natural fibers such as industrial hemp, palm, and banana leaves fibers. Such material would increse the service life and reduce the life cost of the structure, and would have a positive effect on social life and social economy. The demand for the agricultural fibers for concrete production would be a major incentive to Lebanese farmers to benefit from the social impact on the habitat level of living. In the preliminary program reported in this paper, cubes and standard flexural beams were tested to evaluate the structural and physical performance of concrete mixes prepared with different volumetric ratios of added fibers and diffeent proportions of aggregates. Test results indicated that the case of natural fibers resulted in reducing the coarse aggregate quantity without affecting the flexural performance of concrete. However, no clear trend was determined in the cubes compressive strength test results.(author)

Performance Degradation Tests of Phosphoric Acid Doped PBI Membrane Based High Temperature PEM Fuel Cells

DEFF Research Database (Denmark)

Zhou, Fan; Araya, Samuel Simon; Grigoras, Ionela

2014-01-01

Degradation tests of two phosphoric acid (PA) doped PBI membrane based HT-PEM fuel cells were reported in this paper to investigate the effects of start/stop and the presence of methanol in the fuel to the performance degradation. Continuous tests with H2 and simulated reformate which was composed...... of H2, water steam and methanol as the fuel were performed on both single cells. 12-h-startup/12-h-shutdown dynamic tests were performed on the first single cell with pure dry H2 as the fuel and on the second single cell with simulated reformate as the fuel. Along with the tests electrochemical...... techniques such as polarization curves and electrochemical impedance spectroscopy (EIS) were employed to study the degradation mechanisms of the fuel cells. Both single cells showed an increase in the performance in the H2 continuous tests, because of a decrease in the ORR kinetic resistance probably due...

Performance of (CoPC)n catalyst in active lithium-thionyl chloride cells

Science.gov (United States)

Shah, Pinakin M.

1990-01-01

An experimental study was conducted with anode limited D size cells to characterize the performance of an active lithium-thionyl chloride (Li/SOCl2) system using the polymeric cobalt phthalocyanine, (CoPC)n, catalyst in carbon cathodes. The author describes the results of this experiment with respect to initial voltage delays, operating voltages, and capacities. The effectiveness of the preconditioning methods evolved to alleviate passivation effects on storage are also discussed. The results clearly demonstrated the superior high rate capability of cells with the catalyst. The catalyst did not adversely impact the performance of cells after active storage for up to 6 months, while retaining its beneficial influences.

Thermal plasma treatment of cell-phone waste : preliminary result

Energy Technology Data Exchange (ETDEWEB)

Ruj, B. [Central Mechanical Engineering Research Inst., Durgapur (India). Thermal Engineering Group; Chang, J.S.; Li, O.L. [McMaster Univ., Hamilton, ON (Canada). Dept. of Engineering Physics; Pietsch, G. [RWTH Aachen Univ., Aachen (Germany)

2010-07-01

The cell phone is an indispensable service facilitator, however, the disposal and recycling of cell phones is a major problem. While the potential life span of a mobile phone, excluding batteries, is over 10 years, most of the users upgrade their phones approximately four times during this period. Cell phone waste is significantly more hazardous than many other municipal wastes as it contains thousands of components made of toxic chemicals and metals like lead, cadmium, chromium, mercury, polyvinyl chlorides (PVC), brominated flame retardants, beryllium, antimony and phthalates. Cell phones also use many expensive rare metals. Since cell phones are made up of plastics, metals, ceramics, and trace other substances, primitive recycling or disposal of cell phone waste to landfills and incinerators creates irreversible environmental damage by polluting water and soil, and contaminating air. In order to minimize releases into the environment and threat to human health, the disposal of cell phones needs to be managed in an environmentally friendly way. This paper discussed a safer method of reducing the generation of syngas and hydrocarbons and metal recovery through the treatment of cell phone wastes by a thermal plasma. The presentation discussed the experiment, with particular reference to sample preparation; experimental set-up; and results four samples with different experimental conditions. It was concluded that the plasma treatment of cell phone waste in reduced condition generates gaseous components such as hydrogen, carbon monoxide, and hydrocarbons which are combustible. Therefore, this system is an energy recovery system that contributes to resource conservation and reduction of climate change gases. 5 refs., 2 tabs., 2 figs.

Modelling of proton exchange membrane fuel cell performance based on semi-empirical equations

Energy Technology Data Exchange (ETDEWEB)

Al-Baghdadi, Maher A.R. Sadiq [Babylon Univ., Dept. of Mechanical Engineering, Babylon (Iraq)

2005-08-01

Using semi-empirical equations for modeling a proton exchange membrane fuel cell is proposed for providing a tool for the design and analysis of fuel cell total systems. The focus of this study is to derive an empirical model including process variations to estimate the performance of fuel cell without extensive calculations. The model take into account not only the current density but also the process variations, such as the gas pressure, temperature, humidity, and utilization to cover operating processes, which are important factors in determining the real performance of fuel cell. The modelling results are compared well with known experimental results. The comparison shows good agreements between the modeling results and the experimental data. The model can be used to investigate the influence of process variables for design optimization of fuel cells, stacks, and complete fuel cell power system. (Author)

Performance of a low-cost methane sensor for ambient concentration measurements in preliminary studies

Directory of Open Access Journals (Sweden)

W. Eugster

2012-08-01

Full Text Available Methane is the second most important greenhouse gas after CO₂ and contributes to global warming. Its sources are not uniformly distributed across terrestrial and aquatic ecosystems, and most of the methane flux is expected to stem from hotspots which often occupy a very small fraction of the total landscape area. Continuous time-series measurements of CH₄ concentrations can help identify and locate these methane hotspots. Newer, low-cost trace gas sensors such as the Figaro TGS 2600 can detect CH₄ even at ambient concentrations. Hence, in this paper we tested this sensor under real-world conditions over Toolik Lake, Alaska, to determine its suitability for preliminary studies before placing more expensive and service-intensive equipment at a given locality. A reasonably good agreement with parallel measurements made using a Los Gatos Research FMA 100 methane analyzer was found after removal of the strong sensitivities for temperature and relative humidity. Correcting for this sensitivity increased the absolute accuracy required for in-depth studies, and the reproducibility between two TGS 2600 sensors run in parallel is very good. We conclude that the relative CH₄ concentrations derived from such sensors are sufficient for preliminary investigations in the search of potential methane hotspots.

Preliminary Tests of a New Low-Cost Photogrammetric System

Science.gov (United States)

Santise, M.; Thoeni, K.; Roncella, R.; Sloan, S. W.; Giacomini, A.

2017-11-01

This paper presents preliminary tests of a new low-cost photogrammetric system for 4D modelling of large scale areas for civil engineering applications. The system consists of five stand-alone units. Each of the units is composed of a Raspberry Pi 2 Model B (RPi2B) single board computer connected to a PiCamera Module V2 (8 MP) and is powered by a 10 W solar panel. The acquisition of the images is performed automatically using Python scripts and the OpenCV library. Images are recorded at different times during the day and automatically uploaded onto a FTP server from where they can be accessed for processing. Preliminary tests and outcomes of the system are discussed in detail. The focus is on the performance assessment of the low-cost sensor and the quality evaluation of the digital surface models generated by the low-cost photogrammetric systems in the field under real test conditions. Two different test cases were set up in order to calibrate the low-cost photogrammetric system and to assess its performance. First comparisons with a TLS model show a good agreement.

PRELIMINARY TESTS OF A NEW LOW-COST PHOTOGRAMMETRIC SYSTEM

Directory of Open Access Journals (Sweden)

M. Santise

2017-11-01

Full Text Available This paper presents preliminary tests of a new low-cost photogrammetric system for 4D modelling of large scale areas for civil engineering applications. The system consists of five stand-alone units. Each of the units is composed of a Raspberry Pi 2 Model B (RPi2B single board computer connected to a PiCamera Module V2 (8 MP and is powered by a 10 W solar panel. The acquisition of the images is performed automatically using Python scripts and the OpenCV library. Images are recorded at different times during the day and automatically uploaded onto a FTP server from where they can be accessed for processing. Preliminary tests and outcomes of the system are discussed in detail. The focus is on the performance assessment of the low-cost sensor and the quality evaluation of the digital surface models generated by the low-cost photogrammetric systems in the field under real test conditions. Two different test cases were set up in order to calibrate the low-cost photogrammetric system and to assess its performance. First comparisons with a TLS model show a good agreement.

Preliminary design of RDE feedwater pump impeller

International Nuclear Information System (INIS)

Sri Sudadiyo

2018-01-01

Nowadays, pumps are being widely used in the thermal power generation including nuclear power plants. Reaktor Daya Experimental (RDE) is a proposed nuclear reactor concept for the type of nuclear power plant in Indonesia. This RDE has thermal power 10 MW th , and uses a feedwater pump within its steam cycle. The performance of feedwater pump depends on size and geometry of impeller model, such as the number of blades and the blade angle. The purpose of this study is to perform a preliminary design on an impeller of feedwater pump for RDE and to simulate its performance characteristics. The Fortran code is used as an aid in data calculation in order to rapidly compute the blade shape of feedwater pump impeller, particularly for a RDE case. The calculations analyses is solved by utilizing empirical correlations, which are related to size and geometry of a pump impeller model, while performance characteristics analysis is done based on velocity triangle diagram. The effect of leakage, pass through the impeller due to the required clearances between the feedwater pump impeller and the volute channel, is also considered. Comparison between the feedwater pump of HTR-10 and of RDE shows similarity in the trend line of curve shape. These characteristics curves will be very useful for the values prediction of performance of a RDE feedwater pump. Preliminary design of feedwater pump provides the size and geometry of impeller blade model with 5-blades, inlet angle 14.5 degrees, exit angle 25 degrees, inside diameter 81.3 mm, exit diameter 275.2 mm, thickness 4.7 mm, and height 14.1 mm. In addition, the optimal values of performance characteristics were obtained when flow capacity was 4.8 kg/s, fluid head was 29.1 m, shaft mechanical power was 2.64 kW, and efficiency was 52 % at rotational speed 1750 rpm. (author)

Compatibility and performance of separators in Li/SOCl(sub 2) cells

Science.gov (United States)

Cieslak, Wendy R.

1988-05-01

Degradation of many common separator materials, such as polyethylene, excludes their uses in SOCl2 electrolytes. Degradation of the binder in an otherwise chemically-resistant separator may also eliminate it for use in this aggressive environment. We are interested in a separator that does not degrade during more than 10-year storage in either active or reserve cells. Even in reserve configurations, degradation may occur by reaction with Li. Additionally, the separator must be flexible and strong enough for a spiral-wound cell, and it must have the proper thickness and porosity for optimum performance. The properties of three categories of separator materials have been investigated: polymers, glasses and ceramics. We have performed compatibility tests in LiAlCl4/SOCl2 electrolyte and in contact with Li (no electrolyte), and we have assessed electrochemical performance in laboratory cells. The purpose of these tests was to screen a wide variety of materials to identify several candidate separators so that a specific product might readily be chosen on the basis of application requirements.

Identification of transplanted pancreatic islet cells by radioactive Dithizone-[131I]-Histamine conjugate. Preliminary report

International Nuclear Information System (INIS)

Garnuszek, P.; Licinska, I.; Mazurek, A.P.; Mrozek, A.; Wardawa, A.; Fiedor, P.S.

2000-01-01

Background: The unique mechanism of dithizone action in the interior of the viable pancreatic islet suggests the possible development of a specific radiopharmaceutical that may have a potential clinical application in the diagnosis of the pancreatic organ allografts or islets rejection. The radiodiagnostic properties of the newly developed radioactive analogue of dithizone, i.e. Dithizone-[131I]-Histamine conjugate have been evaluated in the present study. METHODS: The four islet cells transplantation models were chosen for this purpose. The most important feature of the Dithizone-[131I]-Histamine conjugate is its possessed ability of zinc chelation. As was presented in the recent study, the conjugate stains pink-reddish the isolated pancreatic islets in vitro. Among the studied transplantation models, only the islets grafting under testis capsule enabled determination of the pancreatic islets in rats by radioactive Dithizone-[131I]-Histamine conjugate. The level of the radioactivity in the recipient testis (right) was almost two times higher compared to the controls (0.24 v. 0.13% ID/g, respectively). CONCLUSIONS: These preliminary data demonstrate the ability of the developed radioactive analogue of dithizone for in vivo identification of transplanted pancreatic islets, and suggests a potential clinical application of the radiodithizone in the diagnosis of the pancreatic islet rejection. (author)

Porous titanium obtained by a new powder metallurgy technique: Preliminary results of human osteoblast adhesion on surface polished substrates.

Science.gov (United States)

Biasotto, M; Ricceri, R; Scuor, N; Schmid, C; Sandrucci, M A; Di Lenarda, R; Matteazzi, P

2003-01-01

This study concerns a novel powder metallurgy method for producing porous titanium (pTi) exhibiting high mechanical properties. The preparation procedure consisted of the following stages: first, the preparation of Ti and titanium hydride (TiH2) powder mixtures and their consolidation with a cold isostatic press, followed by a sintering of the green bodies performed with hot isostatic press (HIP) equipment. Thermal decomposition in controlled environment of the TiH2 phase results in the foam structure. The resulting porosity percolates with a volume fraction of approximately 20%. The final material exhibits interesting mechanical properties, comparable to those of full density titanium (between grade 2 and grade 3), with the advantage of a minor density. The samples produced were tested to verify their biological response by studying the effectiveness of osteoblast adhesion and growth. In this preliminary study, osteoblastic cell morphology was investigated and compared to that observed on fully dense commercially pure titanium (Ti-cp) (ASTM, grade 3). The preliminary results were promising regarding cellular adhesion and spreading. (Journal of Applied Biomaterials & Biomechanics 2003; 1: 172-7).

Environmental Survey preliminary report

Energy Technology Data Exchange (ETDEWEB)

1988-04-01

This report presents the preliminary findings from the first phase of the Environmental Survey of the United States Department of Energy (DOE) Sandia National Laboratories conducted August 17 through September 4, 1987. The objective of the Survey is to identify environmental problems and areas of environmental risk associated with Sandia National Laboratories-Albuquerque (SNLA). The Survey covers all environmental media and all areas of environmental regulation. It is being performed in accordance with the DOE Environmental Survey Manual. This phase of the Survey involves the review of existing site environmental data, observations of the operations carried on at SNLA, and interviews with site personnel. 85 refs., 49 figs., 48 tabs.

Detectability index of differential phase contrast CT compared with conventional CT: a preliminary channelized Hotelling observer study

Science.gov (United States)

Tang, Xiangyang; Yang, Yi; Tang, Shaojie

2013-03-01

Under the framework of model observer with signal and background exactly known (SKE/BKE), we investigate the detectability of differential phase contrast CT compared with that of the conventional attenuation-based CT. Using the channelized Hotelling observer and the radially symmetric difference-of-Gaussians channel template , we investigate the detectability index and its variation over the dimension of object and detector cells. The preliminary data show that the differential phase contrast CT outperforms the conventional attenuation-based CT significantly in the detectability index while both the object to be detected and the cell of detector used for data acquisition are relatively small. However, the differential phase contrast CT's dominance in the detectability index diminishes with increasing dimension of either object or detector cell, and virtually disappears while the dimension of object or detector cell approaches a threshold, respectively. It is hoped that the preliminary data reported in this paper may provide insightful understanding of the differential phase contrast CT's characteristic in the detectability index and its comparison with that of the conventional attenuation-based CT.

Output performance analyses of solar array on stratospheric airship with thermal effect

International Nuclear Information System (INIS)

Li, Jun; Lv, Mingyun; Tan, Dongjie; Zhu, Weiyu; Sun, Kangwen; Zhang, Yuanyuan

2016-01-01

Highlights: • A model investigating the output power of solar array is proposed. • The output power in the cruise condition with thermal effect is researched. • The effect of some factors on output performance is discussed in detail. • A suitable transmissivity of external layer is crucial in preliminary design step. - Abstract: Output performance analyses of the solar array are very critical for solving the energy problem of a long endurance stratospheric airship, and the solar cell efficiency is very sensitive to temperature of the solar cell. But the research about output performance of solar array with thermal effect is rare. This paper outlines a numerical model including the thermal model of airship and solar cells, the incident solar radiation model on the solar array, and the power output model. Based on this numerical model, a MATLAB computer program is developed. In the course of the investigation, the comparisons of the simulation results with and without considering thermal effect are reported. Furthermore, effects of the transmissivity of external encapsulation layer of solar array and wind speed on the thermal performance and output power of solar array are discussed in detail. The results indicate that this method is helpful for planning energy management.

Lithium alloy-thionyl chloride cells - Performance and safety aspects

Science.gov (United States)

Peled, E.; Lombardi, A.; Schlaikjer, C. R.

1983-06-01

It is pointed out that the lithium-thionyl chloride cell has the highest energy density among all the commercially available batteries. The low rate, AA-bobbin cathode cell has been in the marketplace for several years, while the wound or spiral electrode cell is still in the stage of development. The main reason for this are safety problems. These problems are related to the very high reactivity of lithium toward thionyl chloride and the rather low melting point of lithium (180.5 C). The practical stability of the system depends on an LiCl-passivating layer which forms spontaneously on the immersion of the lithium in the electrolyte. This layer serves as a solid electrolyte interphase (SEI). Under certain extreme conditions, however, the SEI can be damaged in such a way that an explosion of the cell occurs. The present investigation is concerned with the reduction of the short-circuit current and the improvement of the safety performance of the cell by the use of special, treated lithium alloys.

Preliminary X-ray crystallographic analysis of sulfide:quinone oxidoreductase from Acidithiobacillus ferrooxidans

International Nuclear Information System (INIS)

Zhang, Yanfei; Cherney, Maia M.; Solomonson, Matthew; Liu, Jianshe; James, Michael N. G.; Weiner, Joel H.

2009-01-01

The sulfide:quinone oxidoreductase from A. ferrooxidans ATCC 23270 was overexpressed in E. coli and purified. Crystallization and preliminarily X-ray crystallographic analysis were performed for the recombinant enzyme. The gene product of open reading frame AFE-1293 from Acidithiobacillus ferrooxidans ATCC 23270 is annotated as encoding a sulfide:quinone oxidoreductase, an enzyme that catalyses electron transfer from sulfide to quinone. Following overexpression in Escherichia coli, the enzyme was purified and crystallized using the hanging-drop vapour-diffusion method. The native crystals belonged to the tetragonal space group P4 2 2 1 2, with unit-cell parameters a = b = 131.7, c = 208.8 Å, and diffracted to 2.3 Å resolution. Preliminary crystallographic analysis indicated the presence of a dimer in the asymmetric unit, with an extreme value of the Matthews coefficient (V M ) of 4.53 Å 3 Da −1 and a solvent content of 72.9%

Design and performance of U7B beamline and X-ray diffraction and scattering station at NSRL and its preliminary experiments in protein crystallography

International Nuclear Information System (INIS)

Pan Guoqiang; Xu, Chaoyin; Fan Rong; Gao Chen; Lou Xiaohua; Teng Maikun; Huang Qingqiu; Niu Liwen

2005-01-01

This publication describes the design and performance of the U7B beamline and X-ray diffraction and diffuse scattering station at National Synchrotron Radiation Laboratory (NSRL). The beamline optics comprise a Pt-coated toroidal focusing mirror and a double-crystal Si(1 1 1) monochromator. A preliminary experiment of diffraction data collection and processing was carried out using a commercial imaging plate detector system (Mar345). The data collected from one single crystal of acutohaemolysin, a Lys49-type PLA2 from Agkistrodon acutus venom, are of high quality

BIPS-FS preliminary design, miscellaneous notes

International Nuclear Information System (INIS)

1976-01-01

A compendium of flight system preliminary design internal memos and progress report extracts for the Brayton Isotope Power System Preliminary Design Review to be held July 20, 21, and 22, 1975 is presented. The purpose is to bring together those published items which relate only to the preliminary design of the Flight System, Task 2 of Phase I. This preliminary design effort was required to ensure that the Ground Demonstration System will represent the Flight System as closely as possible

45 CFR 150.217 - Preliminary determination.

Science.gov (United States)

2010-10-01

... 45 Public Welfare 1 2010-10-01 2010-10-01 false Preliminary determination. 150.217 Section 150.217... Are Failing To Substantially Enforce HIPAA Requirements § 150.217 Preliminary determination. If, at... designees). (b) Notifies the State of CMS's preliminary determination that the State has failed to...

Cell module and fuel conditioner development

Science.gov (United States)

Hoover, D. Q., Jr.

1980-01-01

Components for the first 5 cell stack (no cooling plates) of the MK-2 design were fabricated. Preliminary specfications and designs for the components of a 23 cell MK-1 stack with four DIGAS cooling plates were developed. The MK-2 was selected as a bench mark design and a preliminary design of the facilities required for high rate manufacture of fuel cell modules was developed. Two stands for testing 5 cell stacks were built and design work for modifying existing stands and building new stands for 23 and 80 cell stacks was initiated. Design and procurement of components and materials for the catalyst test stand were completed and construction initiated. Work on the specifications of pipeline gas, tap water and recovered water and definition of equipment required for treatment was initiated. An innovative geometry for the reformer was conceived and modifications of the computer program to be used in its design were stated.

Analysis of A549 cell proteome alteration in response to recombinant influenza A virus nucleoprotein and its interaction with cellular proteins, a preliminary study.

Science.gov (United States)

Kumar, D; Tiwari, K; Rajala, M S

Influenza A virus undergoes frequent changes of antigenicity and contributes to seasonal epidemics or unpredictable pandemics. Nucleoprotein, encoded by gene segment 5, is an internal protein of the virus and is conserved among strains of different host origins. In the current study, we analyzed the differentially expressed proteins in A549 cells transiently transfected with the recombinant nucleoprotein of influenza A virus by 2D gel electrophoresis. The resolved protein spots on gel were identified by MALDI-TOF/Mass spectrometry analysis. The majority of the host proteins detected to be differentially abundant in recombinant nucleoprotein-expressing cells as compared to vector-transfected cells are the proteins of metabolic pathways, glycolytic enzymes, molecular chaperones and cytoskeletal proteins. We further demonstrated the interaction of virus nucleoprotein with some of the identified host cellular proteins. In vitro binding assay carried out using the purified recombinant nucleoprotein (pET29a+NP-His) and A549 cell lysate confirmed the interaction between nucleoprotein and host proteins, such as alpha enolase 1, pyruvate kinase and β-actin. The preliminary data of our study provides the information on virus nucleoprotein interaction with proteins involved in glycolysis. However, studies are ongoing to understand the significance of these interactions in modulating the host factors during virus replication.

Effects of emotionally charged auditory stimulation on gait performance in the elderly: a preliminary study.

Science.gov (United States)

Rizzo, John-Ross; Raghavan, Preeti; McCrery, J R; Oh-Park, Mooyeon; Verghese, Joe

2015-04-01

To evaluate the effect of a novel divided attention task-walking under auditory constraints-on gait performance in older adults and to determine whether this effect was moderated by cognitive status. Validation cohort. General community. Ambulatory older adults without dementia (N=104). Not applicable. In this pilot study, we evaluated walking under auditory constraints in 104 older adults who completed 3 pairs of walking trials on a gait mat under 1 of 3 randomly assigned conditions: 1 pair without auditory stimulation and 2 pairs with emotionally charged auditory stimulation with happy or sad sounds. The mean age of subjects was 80.6±4.9 years, and 63% (n=66) were women. The mean velocity during normal walking was 97.9±20.6cm/s, and the mean cadence was 105.1±9.9 steps/min. The effect of walking under auditory constraints on gait characteristics was analyzed using a 2-factorial analysis of variance with a 1-between factor (cognitively intact and minimal cognitive impairment groups) and a 1-within factor (type of auditory stimuli). In both happy and sad auditory stimulation trials, cognitively intact older adults (n=96) showed an average increase of 2.68cm/s in gait velocity (F1.86,191.71=3.99; P=.02) and an average increase of 2.41 steps/min in cadence (F1.75,180.42=10.12; Pactivities of daily living accounted for these differences. Our results provide preliminary evidence of the differentiating effect of emotionally charged auditory stimuli on gait performance in older individuals with minimal cognitive impairment compared with those without minimal cognitive impairment. A divided attention task using emotionally charged auditory stimuli might be able to elicit compensatory improvement in gait performance in cognitively intact older individuals, but lead to decompensation in those with minimal cognitive impairment. Further investigation is needed to compare gait performance under this task to gait on other dual-task paradigms and to separately examine the

Feasibly study of gas-cooled test cell for material testing in IFMIF

International Nuclear Information System (INIS)

Yonemoto, Yukihiro; Maki, Eiji; Ebara, Shinji; Yokomine, Takehiko; Shimizu, Akihiko; Korenaga, Tadashi

2002-01-01

Temperature control performance of test pieces enclosed in IFMIF capsule by using single phase gas was estimated experimentally. The key issue of this study is to obtain the definite value of dimension of test facility and flow conditions of coolant and to clarify the temperature response of test piece to the beam-off scenario. Firstly, we have examined the cooling performance of the test cell originally proposed in IFMIF-KEP and from results of this calculation performed in three dimensional system by using brand-new turbulence model for flow and thermal fields, it is concluded that the drastical change of design of test cell is needed in order to obtain the unformity of temperature of test piece, to improve the responsibility of temperature measurement of test piece, and to relieve the coolant flow condition, especially for inlet pressure value. Thus, we have proposed new design of test cell and test piece arrangement. A mock-up experimental facility was made based on our design and preliminary experiments for temperature control were performed. As a result, we have verified the cooling performance at the case that corresponds to two beam-off scenario by using mock-up facility

School Performance and Disease Interference in Adolescents with Sickle Cell Disease

Science.gov (United States)

Crosby, Lori E.; Joffe, Naomi E.; Irwin, Mary Kay; Strong, Heather; Peugh, James; Shook, Lisa; Kalinyak, Karen A.; Mitchell, Monica J.

2015-01-01

Sickle cell disease (SCD) results in neuropsychological complications that place adolescents at higher risk for limited educational achievement. A first step to developing effective educational interventions is to understand the impact of SCD on school performance. The current study assessed perceptions of school performance, SCD interference and…

Trade-off results and preliminary designs of Near-Term Hybrid Vehicles

Science.gov (United States)

Sandberg, J. J.

1980-01-01

Phase I of the Near-Term Hybrid Vehicle Program involved the development of preliminary designs of electric/heat engine hybrid passenger vehicles. The preliminary designs were developed on the basis of mission analysis, performance specification, and design trade-off studies conducted independently by four contractors. THe resulting designs involve parallel hybrid (heat engine/electric) propulsion systems with significant variation in component selection, power train layout, and control strategy. Each of the four designs is projected by its developer as having the potential to substitute electrical energy for 40% to 70% of the petroleum fuel consumed annually by its conventional counterpart.

In Vitro Exposure of Porcine Ovarian Follicular Cells to PCB 153 Alters Steroid Secretion But Not Their Viability—Preliminary Study

Directory of Open Access Journals (Sweden)

Ewa L. Gregoraszczuk

2002-01-01

Full Text Available In our previous paper[1], we demonstrated that porcine follicles collected during the early stage of development are the most sensitive to the toxic action of polychlorinated biphenyl 153 (PCB 153. Follicles of this type were collected to test the effect of PCB 153 on cell steroidogenesis and viability. Cocultures of granulosa and theca cells were grown in M199 medium at 37ºC. Control cultures were maintained in that medium alone, while experimental ones were supplemented with PCB 153 at doses of 5, 10, 50, and 100 ng/ml. After 48, 96, and 144 h, media were collected for steroid analysis and cell viability was measured using an LDH (lactate dehydrogenase activity cytotoxicity test. A 2-day exposure of follicular cells to all the investigated doses of PCB 153 caused a statistically significant decrease in progesterone (P4 secretion, while in doses of 50 and 100 ng/ml there was also a decrease in testosterone (T secretion. No effect on estradiol (E2 secretion was observed. The observed decrease in P4 and T secretion, and lack of any statistically significant effect on E2 secretion by cells from small follicles exposed for 48 h to PCB, suggests that PCB 153 acts before P4 formation. Longer exposures caused an increase in P4 secretion, with a concomitant drastic decrease in T secretion and a tendency to decrease the E2 secretion, suggesting inhibition of P450 17α hydroxysteroid dehydrogenase, an enzyme that converts P4 to T. The observed PCB 153–induced increase in P4 secretion by cells collected from small antral follicles, with a concomitant decrease in E2 secretion, accounts for the induction of luteinization and, in this case, inhibition of aromatization process in the follicles. However, in all doses tested and at all times of exposure, PCB 153 had no effect on cell viability. These findings suggest different time of exposure–dependent action of PCB 153 on particular steps of steroidogenesis but not action on cell viability. These results

Exploratory shaft facility preliminary designs - Permian Basin

International Nuclear Information System (INIS)

1983-09-01

The purpose of the Preliminary Design Report, Permian Basin, is to provide a description of the preliminary design for an Exploratory Shaft Facility in the Permian Basin, Texas. This issue of the report describes the preliminary design for constructing the exploratory shaft using the Large Hole Drilling method of construction and outlines the preliminary design and estimates of probable construction cost. The Preliminary Design Report is prepared to complement and summarize other documents that comprise the design at the preliminary stage of completion, December 1982. Other design documents include drawings, cost estimates and schedules. The preliminary design drawing package, which includes the construction schedule drawing, depicts the descriptions in this report. For reference, a list of the drawing titles and corresponding numbers are included in the Appendix. The report is divided into three principal sections: Design Basis, Facility Description, and Construction Cost Estimate. 30 references, 13 tables

X-ray microbeam stand-alone facility for cultured cells irradiation

Energy Technology Data Exchange (ETDEWEB)

Bożek, Sebastian, E-mail: sebastian.bozek@yahoo.com [Jagiellonian University Medical College, Department of Pharmaceutical Biophysics, Krakow (Poland); Bielecki, Jakub; Wiecheć, Anna; Lekki, Janusz; Stachura, Zbigniew; Pogoda, Katarzyna; Lipiec, Ewelina; Tkocz, Konrad; Kwiatek, Wojciech M. [Institute of Nuclear Physics Polish Academy of Sciences, PL-31342 Krakow (Poland)

2017-03-01

Highlights: • An X-ray microbeam line for irradiation of living cultured cells was constructed. • A step by step explanation of working principles with engineering details, procedures and calculations is presented. • A model of beam and cell interaction is presented. • A method of uniform irradiation of living cells with an exact dose per a cell is presented. • Results of preliminary experiments are presented. - Abstract: The article describes an X-ray microbeam standalone facility dedicated for irradiation of living cultured cells. The article can serve as an advice for such facilities construction, as it begins from engineering details, through mathematical modeling and experimental procedures, ending up with preliminary experimental results and conclusions. The presented system consists of an open type X-ray tube with microfocusing down to about 2 μm, an X-ray focusing system with optical elements arranged in the nested Kirckpatrick-Baez (or Montel) geometry, a sample stand and an optical microscope with a scientific digital CCD camera. For the beam visualisation an X-ray sensitive CCD camera and a spectral detector are used, as well as a scintillator screen combined with the microscope. A method of precise one by one irradiation of previously chosen cells is presented, as well as a fast method of uniform irradiation of a chosen sample area. Mathematical models of beam and cell with calculations of kerma and dose are presented. The experiments on dose-effect relationship, kinetics of DNA double strand breaks repair, as well as micronuclei observation were performed on PC-3 (Prostate Cancer) cultured cells. The cells were seeded and irradiated on Mylar foil, which covered a hole drilled in the Petri dish. DNA lesions were visualised with γ-H2AX marker combined with Alexa Fluor 488 fluorescent dye.

Performance of a polymer electrolyte membrane fuel cell with thin film catalyst electrodes

Energy Technology Data Exchange (ETDEWEB)

Chun, Young Gab; Kim, Chang Soo; Peck, Dong Hyun; Shin, Dong Ryul [Korea Institute of Energy Research, Taejon (Korea, Republic of)

1998-03-15

In order to develop a kW-class polymer electrolyte membrane fuel cell (PEMFC), several electrodes have been fabricated by different catalyst layer preparation procedures and evaluated based on the cell performance. Conventional carbon paper and carbon cloth electrodes were fabricated using a ptfe-bonded Pt/C electrol catalyst by coating and rolling methods. Thin-film catalyst/ionomer composite layers were also formed on the membrane by direct coating and transfer printing techniques. The performance evaluation with catalyst layer preparation methods was carried out using a large or small electrode single cell. Conventional and thin film membrane and electrode assemblies (MEAs) with small electrode area showed a performance of 350 and 650 mA/cm{sup 2} at 0.6 V, respectively. The performance of direct coated thin film catalyst layer with 300 cm{sup 2} MEAs was higher than those of the conventional and transfer printing technique MEAs. The influence of some characteristic parameters of the thin film electrode on electrochemical performance was examined. Various other aspects of overall operation of PEMFC stacks were also discussed. (orig.)

Development and preliminary experimental study on micro-stacked insulator

International Nuclear Information System (INIS)

Ren Chengyan; Yuan Weiqun; Zhang Dongdong; Yan Ping; Wang Jue

2009-01-01

High gradient insulating technology is one of the key technologies in new type dielectric wall accelerator(DWA). High gradient insulator, namely micro-stacked insulator, was developed and preliminary experimental study was done. Based on the finite element and particle simulating method, surface electric field distribution and electron movement track of micro-stacked insulator were numerated, and then the optimized design proposal was put forward. Using high temperature laminated method, we developed micro-stacked insulator samples which uses exhaustive fluorinated ethylene propylene(FEP) as dielectric layer and stainless steel as metal layer. Preliminary experiment of vacuum surface flashover in nanosecond pulse voltage was done and micro-stacked insulator exhibited favorable vacuum surface flashover performance with flashover field strength of near 180 kV/cm. (authors)

Percutaneous Irreversible Electroporation Lung Ablation: Preliminary Results in a Porcine Model

International Nuclear Information System (INIS)

Deodhar, Ajita; Monette, Sébastien; Single, Gordon W.; Hamilton, William C.; Thornton, Raymond H.; Sofocleous, Constantinos T.; Maybody, Majid; Solomon, Stephen B.

2011-01-01

Objective: Irreversible electroporation (IRE) uses direct electrical pulses to create permanent “pores” in cell membranes to cause cell death. In contrast to conventional modalities, IRE has a nonthermal mechanism of action. Our objective was to study the histopathological and imaging features of IRE in normal swine lung. Materials and Methods: Eleven female swine were studied for hyperacute (8 h), acute (24 h), subacute (96 h), and chronic (3 week) effects of IRE ablation in lung. Paired unipolar IRE applicators were placed under computed tomography (CT) guidance. Some applicators were deliberately positioned near bronchovascular structures. IRE pulse delivery was synchronized with the cardiac rhythm only when ablation was performed within 2 cm of the heart. Contrast-enhanced CT scan was performed immediately before and after IRE and at 1 and 3 weeks after IRE ablation. Representative tissue was stained with hematoxylin and eosin for histopathology. Results: Twenty-five ablations were created: ten hyperacute, four acute, and three subacute ablations showed alveolar edema and necrosis with necrosis of bronchial, bronchiolar, and vascular epithelium. Bronchovascular architecture was maintained. Chronic ablations showed bronchiolitis obliterans and alveolar interstitial fibrosis. Immediate post-procedure CT images showed linear or patchy density along the applicator tract. At 1 week, there was consolidation that resolved partially or completely by 3 weeks. Pneumothorax requiring chest tube developed in two animals; no significant cardiac arrhythmias were noted. Conclusion: Our preliminary porcine study demonstrates the nonthermal and extracellular matrix sparing mechanism of action of IRE. IRE is a potential alternative to thermal ablative modalities.

Dye-sensitized solar cells and solar module using polymer electrolytes: Stability and performance investigations

Directory of Open Access Journals (Sweden)

Jilian Nei de Freitas

2006-01-01

Full Text Available We present recent results on solid-state dye-sensitized solar cell research using a polymer electrolyte based on a poly(ethylene oxide derivative. The stability and performance of the devices have been improved by a modification in the method of assembly of the cells and by the addition of plasticizers in the electrolyte. After 30 days of solar irradiation (100 mW cm-2 no changes in the cell's efficiency were observed using this new method. The effect of the active area size on cell performance and the first results obtained for the first solar module composed of 4.5 cm2 solid-state solar cells are also presented.

King County Metro Battery Electric Bus Demonstration: Preliminary Project Results

Energy Technology Data Exchange (ETDEWEB)

2017-05-22

The U.S. Federal Transit Administration (FTA) funds a variety of research projects that support the commercialization of zero-emission bus technology. To evaluate projects funded through these programs, FTA has enlisted the help of the National Renewable Energy Laboratory (NREL) to conduct third-party evaluations of the technologies deployed under the FTA programs. NREL works with the selected agencies to evaluate the performance of the zero-emission buses compared to baseline conventional buses in similar service. The evaluation effort will advance the knowledge base of zero-emission technologies in transit bus applications and provide 'lessons learned' to aid other fleets in incrementally introducing next generation zero-emission buses into their operations. This report provides preliminary performance evaluation results from a demonstration of three zero-emission battery electric buses at King County Metro in King County, Washington. NREL developed this preliminary results report to quickly disseminate evaluation results to stakeholders. Detailed evaluation results will be published in future reports.

The Comparative Performance of Batteries: The Lead-Acid and the Aluminum-Air Cells.

Science.gov (United States)

LeRoux, Xavier; And Others

1996-01-01

Describes a teaching program that shows how electrochemical principles can be conveyed by means of hands-on experiences of student-centered teaching experiments. Employs the readily available lead-acid cell and the simple aluminum-air cell. Discusses the batteries, equilibrium cell potential, performance comparison, current, electrode separation,…

Effect of time-varying humidity on the performance of a polymer electrolyte membrane fuel cells

Energy Technology Data Exchange (ETDEWEB)

Noorani, Shamsuddin [Department of Mechanical Engineering, University of Michigan-Dearborn (United States); Shamim, Tariq [Mechanical Engineering, Masdar Institute of Science and Technology (United Arab Emirates)], E-mail: tshamim@masdar.ac.ae

2011-07-01

In the energy sector, fuel cells constitute a promising solution for the future due to their energy-efficient and environment-friendly characteristics. However, the performance of fuel cells is very much affected by the humidification level of the reactants, particularly in hot regions. The aim of this paper is to develop a better understanding of the effect of driving conditions on the performance of fuel cells. A macroscopic single-fuel-cell-based, one dimensional, isothermal model was used on a polymer electrolyte membrane fuel cell to carry out a computational study of the impact of humidity conditions which vary over time. It was found that the variation of humidity has a significant effect on water distribution but a much lower impact on power and current densities. This paper provided useful information on fuel cells' performance under varying conditions which could be used to improve their design for mobile applications.

Preliminary safety assessment of the WIPP facility

International Nuclear Information System (INIS)

Balestri, R.J.; Torres, B.W.; Pahwa, S.B.; Brannen, J.P.

1979-01-01

This paper summarizes the efforts to perform a safety assessment of the Waste Isolation Pilot Plant (WIPP) facility being proposed for southeastern New Mexico. This preliminary safety assessment is limited to a consequence assessment in terms of the dose to a maximally exposed individual as a result of introducing the radionuclides into the biosphere. The extremely low doses to the organs as a result of the liquid breach scenarios are contrasted with the background radiation

Topological cell clustering in the ATLAS calorimeters and its performance in LHC Run 1

Energy Technology Data Exchange (ETDEWEB)

Aad, G. [CPPM, Aix-Marseille Univ. et CNRS/IN2P3, Marseille (France); Abbott, B. [Oklahoma Univ., Norman, OK (United States). Homer L. Dodge Dept. of Physics and Astronomy; Abdallah, J. [Academia Sinica, Taipei (China). Inst. of Physics; Collaboration: ATLAS Collaboration; and others

2017-07-15

The reconstruction of the signal from hadrons and jets emerging from the proton-proton collisions at the Large Hadron Collider (LHC) and entering the ATLAS calorimeters is based on a three-dimensional topological clustering of individual calorimeter cell signals. The cluster formation follows cell signal-significance patterns generated by electromagnetic and hadronic showers. In this, the clustering algorithm implicitly performs a topological noise suppression by removing cells with insignificant signals which are not in close proximity to cells with significant signals. The resulting topological cell clusters have shape and location information, which is exploited to apply a local energy calibration and corrections depending on the nature of the cluster. Topological cell clustering is established as a well-performing calorimeter signal definition for jet and missing transverse momentum reconstruction in ATLAS. (orig.)

Performance evaluation and parametric optimum design of a molten carbonate fuel cell-thermophotovoltaic cell hybrid system

International Nuclear Information System (INIS)

Yang, Zhimin; Liao, Tianjun; Zhou, Yinghui; Lin, Guoxing; Chen, Jincan

2016-01-01

Highlights: • A molten carbonate fuel cell-thermophotovoltaic cell hybrid system is established. • The performance characteristics of the hybrid system are systematically evaluated. • The optimal regions of the power output density and efficiency are determined. • The values of key parameters at the maximum power output density are calculated. • The proposed system is proved to have advantages over other hybrid systems. - Abstract: A new model of the hybrid system composed of a molten carbonate fuel cell (MCFC) and a thermophotovoltaic cell (TPVC) is proposed to recovery the waste heat produced by the MCFC. Expressions for the power output and the efficiency of the hybrid system are analytically derived. The performance characteristics of the hybrid system are evaluated. It is found that when the current density of the MCFC, voltage output of the TPVC, electrode area ratio of the MCFC to the TPVC, and energy gap of the material in the photovoltaic cell are optimally chosen, the maximum power output density of the hybrid system is obviously larger than that of the single MCFC. Moreover, the improved percentages of the maximum power output density of the proposed model relative to that of the single MCFC are calculated for differently operating temperatures of the MCFC and are compared with those of some MCFC-based hybrid systems reported in the literature, and consequently, the advantages of the MCFC-TPVC hybrid system are revealed.

The donor-supply electrode enhances performance in colloidal quantum dot solar cells.

Science.gov (United States)

Maraghechi, Pouya; Labelle, André J; Kirmani, Ahmad R; Lan, Xinzheng; Adachi, Michael M; Thon, Susanna M; Hoogland, Sjoerd; Lee, Anna; Ning, Zhijun; Fischer, Armin; Amassian, Aram; Sargent, Edward H

2013-07-23

Colloidal quantum dot (CQD) solar cells combine solution-processability with quantum-size-effect tunability for low-cost harvesting of the sun's broad visible and infrared spectrum. The highest-performing colloidal quantum dot solar cells have, to date, relied on a depleted-heterojunction architecture in which an n-type transparent metal oxide such as TiO2 induces a depletion region in the p-type CQD solid. These devices have, until now, been limited by a modest depletion region depth produced in the CQD solid owing to limitations in the doping available in TiO2. Herein we report a new device geometry-one based on a donor-supply electrode (DSE)-that leads to record-performing CQD photovoltaic devices. Only by employing this new charge-extracting approach do we deepen the depletion region in the CQD solid and thereby extract notably more photocarriers, the key element in achieving record photocurrent and device performance. With the use of optoelectronic modeling corroborated by experiment, we develop the guidelines for building a superior CQD solar cell based on the DSE concept. We confirm that using a shallow-work-function terminal electrode is essential to producing improved charge extraction and enhanced performance.

Influence of cathode flow pulsation on performance of proton exchange membrane fuel cell with interdigitated gas distributors

International Nuclear Information System (INIS)

Ramiar, A.; Mahmoudi, A.H.; Esmaili, Q.; Abdollahzadeh, M.

2016-01-01

In this paper, a numerical study is conducted in order to investigate the effect of pulsation of air flow at the cathode side of Proton Exchange Membrane (PEM) fuel cell with interdigitated flow field. A two dimensional, isothermal, two-phase, unsteady multi-component transport model is used in order to simulate the transport phenomena. The obtained results are discussed in terms of the influence of flow pulsation on water management and cell performance. The results prove the effectiveness of flow pulsation on improving water removal from cell, enhancing reactants transports to the reaction sites, and increasing the cell performance expressed by increment in the cell limiting current density and maximum output power. The effects of pulsation frequency (f), amplitude (Amp), and mean inlet pressure (P_i_n) on the performance and the output power of the cell, are also investigated. The performance of the cell has no dependency on the frequency range considered in this study. However, as the pulsation amplitude increases the increment in the cell performance is more obvious. Moreover, applying flow pulsation at low flow rates leads to higher efficiency in water removal and performance enhancement. - Highlights: • Mechanism of water and oxygen transport under flow pulsation are discussed. • Pulsating cathode flow increases the limiting current density and output power. • The performance of cell has no significant dependency on pulsation frequency. • The performance and output power increase with the pulsation amplitude. • Using pulsating flow at lower average pressures leads to higher water removal rate.

Expression, crystallization and preliminary crystallographic analysis of the extracellular IgV-like domain of the human natural killer cell inhibitory receptor p75/AIRM1.

Science.gov (United States)

Dimasi, Nazzareno; Moretta, Lorenzo; Biassoni, Roberto; Mariuzza, Roy A

2003-10-01

p75/AIRM1 (Siglec-7) is a sialic acid-binding Ig-like lectin recently identified as an inhibitory receptor on natural killer cells. The expression, in vitro folding, circular-dichroism spectroscopy, crystallization and preliminary X-ray characterization of the Ig-V like domain of p75/AIRM1 are reported. X-ray data were collected from a single crystal at 100 K, with a maximum useful diffraction pattern extending to 1.45 A resolution on a synchrotron source. The crystal belongs to a primitive monoclinic space group, with unit-cell parameters a = 32.65, b = 49.72, c = 39.79 A, alpha = gamma = 90, beta = 113 degrees. The systematic absences indicate that the space group is P2(1). Assuming one molecule per asymmetric unit, V(M) (the Matthews coefficient) was calculated to be 1.879 A(3) Da(-1) and the solvent content was estimated to be 32.01%.

Fabrication and performance analysis of 4-sq cm indium tin oxide/InP photovoltaic solar cells

Science.gov (United States)

Gessert, T. A.; Li, X.; Phelps, P. W.; Coutts, T. J.; Tzafaras, N.

1991-01-01

Large-area photovoltaic solar cells based on direct current magnetron sputter deposition of indium tin oxide (ITO) into single-crystal p-InP substrates demonstrated both the radiation hardness and high performance necessary for extraterrestrial applications. A small-scale production project was initiated in which approximately 50 ITO/InP cells are being produced. The procedures used in this small-scale production of 4-sq cm ITO/InP cells are presented and discussed. The discussion includes analyses of performance range of all available production cells, and device performance data of the best cells thus far produced. Additionally, processing experience gained from the production of these cells is discussed, indicating other issues that may be encountered when large-scale productions are begun.

Performance of Electrolyte Supported Solid Oxide Fuel Cells with STN Anodes

DEFF Research Database (Denmark)

Veltzé, Sune; Reddy Sudireddy, Bhaskar; Jørgensen, Peter Stanley

2013-01-01

In order to replace the state of the art Ni-cermet as SOFC anode, electrolyte supported cells comprising CGO/Ni infiltrated Nbdoped SrTiO3 anodes, and LSM/YSZ cathodes have been developed and tested as single 5 x 5 cm2 cells. The initial performance reached 0.4 W/cm2 at 850 C. Further tests under...

LONG-TERM PERFORMANCE OF SOLID OXIDE STACKS WITH ELECTRODE-SUPPORTED CELLS OPERATING IN THE STEAM ELECTROLYSIS MODE

Energy Technology Data Exchange (ETDEWEB)

J. E. O' Brien; R. C. O' Brien; X. Zhang; G. Tao; B. J. Butler

2011-11-01

Performance characterization and durability testing have been completed on two five-cell high-temperature electrolysis stacks constructed with advanced cell and stack technologies. The solid oxide cells incorporate a negative-electrode-supported multi-layer design with nickel-zirconia cermet negative electrodes, thin-film yttria-stabilized zirconia electrolytes, and multi-layer lanthanum ferrite-based positive electrodes. The per-cell active area is 100 cm2. The stack is internally manifolded with compliant mica-glass seals. Treated metallic interconnects with integral flow channels separate the cells. Stack compression is accomplished by means of a custom spring-loaded test fixture. Initial stack performance characterization was determined through a series of DC potential sweeps in both fuel cell and electrolysis modes of operation. Results of these sweeps indicated very good initial performance, with area-specific resistance values less than 0.5 ?.cm2. Long-term durability testing was performed with A test duration of 1000 hours. Overall performance degradation was less than 10% over the 1000-hour period. Final stack performance characterization was again determined by a series of DC potential sweeps at the same flow conditions as the initial sweeps in both electrolysis and fuel cell modes of operation. A final sweep in the fuel cell mode indicated a power density of 0.356 W/cm2, with average per-cell voltage of 0.71 V at a current of 50 A.

Nuclear code case development of printed-circuit heat exchangers with thermal and mechanical performance testing

Energy Technology Data Exchange (ETDEWEB)

Aakre, Shaun R. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Mechanical Engineering; Jentz, Ian W. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Mechanical Engineering; Anderson, Mark H. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Mechanical Engineering

2018-03-27

The U.S. Department of Energy has agreed to fund a three-year integrated research project to close technical gaps involved with compact heat exchangers to be used in nuclear applications. This paper introduces the goals of the project, the research institutions, and industrial partners working in collaboration to develop a draft Boiler and Pressure Vessel Code Case for this technology. Heat exchanger testing, as well as non-destructive and destructive evaluation, will be performed by researchers across the country to understand the performance of compact heat exchangers. Testing will be performed using coolants and conditions proposed for Gen IV Reactor designs. Preliminary observations of the mechanical failure mechanisms of the heat exchangers using destructive and non-destructive methods is presented. Unit-cell finite element models assembled to help predict the mechanical behavior of these high-temperature components are discussed as well. Performance testing methodology is laid out in this paper along with preliminary modeling results, an introduction to x-ray and neutron inspection techniques, and results from a recent pressurization test of a printed-circuit heat exchanger. The operational and quality assurance knowledge gained from these models and validation tests will be useful to developers of supercritical CO₂ systems, which commonly employ printed-circuit heat exchangers.

Light-induced performance increase of silicon heterojunction solar cells

KAUST Repository

Kobayashi, Eiji; De Wolf, Stefaan; Levrat, Jacques; Christmann, Gabriel; Descoeudres, Antoine; Nicolay, Sylvain; Despeisse, Matthieu; Watabe, Yoshimi; Ballif, Christophe

2016-01-01

Silicon heterojunction solar cells consist of crystalline silicon (c-Si) wafers coated with doped/intrinsic hydrogenated amorphous silicon (a-Si:H) bilayers for passivating-contact formation. Here, we unambiguously demonstrate that carrier injection either due to light soaking or (dark) forward-voltage bias increases the open circuit voltage and fill factor of finished cells, leading to a conversion efficiency gain of up to 0.3% absolute. This phenomenon contrasts markedly with the light-induced degradation known for thin-film a-Si:H solar cells. We associate our performance gain with an increase in surface passivation, which we find is specific to doped a-Si:H/c-Si structures. Our experiments suggest that this improvement originates from a reduced density of recombination-active interface states. To understand the time dependence of the observed phenomena, a kinetic model is presented.

Light-induced performance increase of silicon heterojunction solar cells

KAUST Repository

Kobayashi, Eiji

2016-10-11

Silicon heterojunction solar cells consist of crystalline silicon (c-Si) wafers coated with doped/intrinsic hydrogenated amorphous silicon (a-Si:H) bilayers for passivating-contact formation. Here, we unambiguously demonstrate that carrier injection either due to light soaking or (dark) forward-voltage bias increases the open circuit voltage and fill factor of finished cells, leading to a conversion efficiency gain of up to 0.3% absolute. This phenomenon contrasts markedly with the light-induced degradation known for thin-film a-Si:H solar cells. We associate our performance gain with an increase in surface passivation, which we find is specific to doped a-Si:H/c-Si structures. Our experiments suggest that this improvement originates from a reduced density of recombination-active interface states. To understand the time dependence of the observed phenomena, a kinetic model is presented.

In situ metal ion contamination and the effects on proton exchange membrane fuel cell performance

Science.gov (United States)

Sulek, Mark; Adams, Jim; Kaberline, Steve; Ricketts, Mark; Waldecker, James R.

Automotive fuel cell technology has made considerable progress, and hydrogen fuel cell vehicles are regarded as a possible long-term solution to reduce carbon dioxide emissions, reduce fossil fuel dependency and increase energy efficiency. Even though great strides have been made, durability is still an issue. One key challenge is controlling MEA contamination. Metal ion contamination within the membrane and the effects on fuel cell performance were investigated. Given the possible benefits of using stainless steel or aluminum for balance-of-plant components or bipolar plates, cations of Al, Fe, Ni and Cr were studied. Membranes were immersed in metal sulfide solutions of varying concentration and then assembled into fuel cell MEAs tested in situ. The ranking of the four transition metals tested in terms of the greatest reduction in fuel cell performance was: Al 3+ ≫ Fe 2+ > Ni 2+, Cr 3+. For iron-contaminated membranes, no change in cell performance was detected until the membrane conductivity loss was greater than approximately 15%.

Solvent Engineering for High-Performance PbS Quantum Dots Solar Cells

Directory of Open Access Journals (Sweden)

Rongfang Wu

2017-07-01

Full Text Available PbS colloidal quantum dots (CQDs solar cells have already demonstrated very impressive advances in recent years due to the development of many different techniques to tailor the interface morphology and compactness in PbS CQDs thin film. Here, n-hexane, n-octane, n-heptane, isooctane and toluene or their hybrids are for the first time introduced as solvent for comparison of the dispersion of PbS CQDs. PbS CQDs solar cells with the configuration of PbS/TiO2 heterojunction are then fabricated by using different CQDs solution under ambient conditions. The performances of the PbS CQDs solar cells are found to be tuned by changing solvent and its content in the PbS CQDs solution. The best device could show a power conversion efficiency (PCE of 7.64% under AM 1.5 G illumination at 100 mW cm−2 in a n-octane/isooctane (95%/5% v/v hybrid solvent scheme, which shows a ~15% improvement compared to the control devices. These results offer important insight into the solvent engineering of high-performance PbS CQDs solar cells.

National Data Center Preparedness Exercise 2015 (NPE 2015): MY-NDC Preliminary Analysis Result

International Nuclear Information System (INIS)

Faisal Izwan Abdul Rashid; Muhammed Zulfakar Zolkaffly

2016-01-01

Malaysia has established the CTBT National Data Centre (MY-NDC) in December 2005. MY-NDC is tasked to perform Comprehensive Nuclear-Test-Ban-Treaty (CTBT) data management as well as provide information for Treaty related events to Nuclear Malaysia as CTBT National Authority. In 2015, MY-NDC has participated in the National Data Centre Preparedness Exercise 2015 (NPE 2015). This paper aims at presenting MY-NDC preliminary analysis result of NPE 2015. In NPE 2015, MY-NDC has performed five different analyses, namely, radionuclide, atmospheric transport modelling (ATM), data fusion, seismic analysis and site forensics. The preliminary findings show the hypothetical scenario in NPE 2015 most probably is an uncontained event resulted high release of radionuclide to the air. (author)

Performance of direct methanol fuel cell with a palladium–silica nanofibre/Nafion composite membrane

International Nuclear Information System (INIS)

Thiam, H.S.; Daud, W.R.W.; Kamarudin, S.K.; Mohamad, A.B.; Kadhum, A.A.H.; Loh, K.S.; Majlan, E.H.

2013-01-01

Highlights: • This study introduces Pd–SiO 2 Carbon Nano Fibre as an additive to Nafion membrane. • It investigates the effects of membrane annealing temperature and casting solvent. • Results show that Pd–SiO 2 fibre/Nafion performs lower methanol permeability. • This could effectively reduces methanol crossover in direct methanol fuel cell. - Abstract: Palladium–silica nanofibres (Pd–SiO 2 fibre) were adopted as an additive to Nafion recast membranes in order to reduce methanol crossover and improve the cell performance. The performance of a membrane electrode assembly (MEA) with fabricated composite membrane was evaluated through a passive air-breathing single cell direct methanol fuel cell (DMFC). The limiting crossover current density was measured to determine the methanol permeation in the DMFC. The effects of membrane annealing temperature and casting solvent of composite membrane on the cell performance were investigated and are discussed here. Compared to recast Nafion with the same thickness (150 μm), the Pd–SiO 2 fibre/Nafion composite membrane exhibited higher performance and lower methanol permeability. A maximum power density of 10.4 mW cm −2 was obtained with a 2 M methanol feed, outperforming the much thicker commercial Nafion 117 with a power density of 7.95 mW cm −2 under the same operating conditions. The experimental results showed that the Pd–SiO 2 fibre as inorganic fillers for Nafion could effectively reduce methanol crossover and improve the membrane performance in DMFC applications

Purification, crystallization and preliminary crystallographic analysis of the SH2 domain of IL-2-inducible T-cell kinase.

Science.gov (United States)

Joseph, Raji E; Ginder, Nathaniel D; Hoy, Julie A; Nix, Jay C; Honzatko, Richard B; Andreotti, Amy H

2011-02-01

Proline is a unique amino acid owing to the relatively small energy difference between the cis and trans conformations of its peptide bond. The X-Pro imide bond readily undergoes cis-trans isomerization in the context of short peptides as well as some proteins. However, the direct detection of cis-trans proline isomerization in folded proteins is technically challenging. NMR spectroscopy is well suited to the direct detection of proline isomerization in folded proteins. It is less clear how well X-ray crystallography can reveal this conformational exchange event in folded proteins. Conformational heterogeneity owing to cis-trans proline isomerization in the Src homology 2 (SH2) domain of the IL-2-inducible T-cell kinase (ITK) has been extensively characterized by NMR. Using the ITK SH2 domain as a test system, an attempt was made to determine whether proline isomerization could be detected in a crystal structure of the ITK SH2 domain. As a first step towards this goal, the purification, crystallization and preliminary characterization of the ITK SH2 domain are described.

A Preliminary Fire PSA on PGSFR

International Nuclear Information System (INIS)

Kim, Kilyoo; Han, Sanghoon; Lee, KwiLim

2017-01-01

A Prototype Generation IV Sodium Fast Reactor (PGSFR) is under design with defense in depth concept with active, passive, and inherent safety features to acquire a design approval for PGSFR from Korean regulatory authority by around 2017. A preliminary fire PSA on PGSFR is done in 2016 and a final fire PSA of PGSFR will be done in 2017. The characteristics of the preliminary fire PSA on PGSFR are described in this paper. Since PGSFR is very safe reactor, it is not bad approach to use a conservative assumption in the preliminary PSA. In addition, several drawings including cable routing are not yet issued, a conservative calculation for CDF is performed. As shown in Table 2, the CDF caused by the fire in the control room takes 89% portion of total CDF. Thus, a detailed fire modeling for control room is necessary for the final fire PSA on PGSFR. Also, the increased ignition frequency due to sodium leak would be derived by considering the sodium piping complexity in the final fire PSA on PGSFR. The 4th column of Table 2 is derived the 3rd column by multiplying the factor (592/1177). The 5th column is the ignition frequency caused by the sodium leak. The 6th column is derived by summing the 4th column and the 5th column. The 7th column is the CDF portion of each fire area. The control room (fire area F-A404A) is the most important area since the control room fire takes 89% portion of total CDF.

Numerical study of assembly pressure effect on the performance of proton exchange membrane fuel cell

Energy Technology Data Exchange (ETDEWEB)

Taymaz, Imdat; Benli, Merthan [Department of Mechanical Engineering, University of Sakarya, 54187 Adapazari (Turkey)

2010-05-15

The performance of the fuel cell is affected by many parameters. One of these parameters is assembly pressure that changes the mechanical properties and dimensions of the fuel cell components. Its first duty, however, is to prevent gas or liquid leakage from the cell and it is important for the contact behaviors of fuel cell components. Some leakage and contact problems can occur on the low assembly pressures whereas at high pressures, components of the fuel cell, such as bipolar plates (BPP), gas diffusion layers (GDL), catalyst layers, and membranes, can be damaged. A finite element analysis (FEA) model is developed to predict the deformation effect of assembly pressure on the single channel PEM fuel cell in this study. Deformed fuel cell single channel model is imported to three-dimensional, computational fluid dynamics (CFD) model which is developed for simulating proton exchange membrane (PEM) fuel cells. Using this model, the effect of assembly pressure on fuel cell performance can be calculated. It is found that, when the assembly pressure increases, contact resistance, porosity and thickness of the gas diffusion layer (GDL) decreases. Too much assembly pressure causes GDL to destroy; therefore, the optimal assembly pressure is significant to obtain the highest performance from fuel cell. By using the results of this study, optimum fuel cell design and operating condition parameters can be predicted accordingly. (author)

Performance Analysis of Air Breathing Proton Exchange Membrane Fuel Cell Stack (PEMFCS) At Different Operating Condition

Science.gov (United States)

Sunil, V.; Venkata siva, G.; Yoganjaneyulu, G.; Ravikumar, V. V.

2017-08-01

The answer for an emission free power source in future is in the form of fuel cells which combine hydrogen and oxygen producing electricity and a harmless by product-water. A proton exchange membrane (PEM) fuel cell is ideal for automotive applications. A single cell cannot supply the essential power for any application. Hence PEM fuel cell stacks are used. The effect of different operating parameters namely: type of convection, type of draught, hydrogen flow rate, hydrogen inlet pressure, ambient temperature and humidity, hydrogen humidity, cell orientation on the performance of air breathing PEM fuel cell stack was analyzed using a computerized fuel cell test station. Then, the fuel cell stack was subjected to different load conditions. It was found that the stack performs very poorly at full capacity (runs only for 30 min. but runs for 3 hours at 50% capacity). Hence, a detailed study was undertaken to maximize the duration of the stack’s performance at peak load.

Treatment of Unruptured Intracranial Aneurysms and Cognitive Performance: Preliminary Results of a Prospective Clinical Trial.

Science.gov (United States)

Bründl, Elisabeth; Böhm, Christina; Lürding, Ralf; Schödel, Petra; Bele, Sylvia; Hochreiter, Andreas; Scheitzach, Judith; Zeman, Florian; Brawanski, Alexander; Schebesch, Karl-Michael

2016-10-01

Few studies have addressed the effect of treatment of unruptured intracranial aneurysm (UIA) on cognitive function. Neuropsychological assessment after UIA treatment is underreported, and prospective trials have repeatedly been demanded. In 2014, we conducted a prospective controlled study to evaluate the differences in cognitive processing caused by the treatment of anterior circulation UIAs. Thirty patients were enrolled until September 2015. Ten patients received endovascular aneurysm occlusion (EV), 10 patients were treated microsurgically (MS), and 10 patients with surgically treated degenerative lumbar spine disease (LD) served as control. All patients underwent extended standardized neuropsychological assessment before (t 1 ) and 6 weeks after treatment (t 2 ). Tests included verbal, visual, and visuospatial memory, psychomotor functioning, executive functioning, and its subdomains verbal fluency and cognitive flexibility. We statistically evaluated intragroup and intergroup changes. Intragroup comparisons and group-rate analysis showed no significant impairment in overall neuropsychological performance, either postinterventionally or postoperatively. However, the postoperative performance in cognitive processing speed, cognitive flexibility, and executive functioning was significantly worse in the MS group than in the EV (P = 0.038) and LD group (P = 0.02). Compared with the EV group, patients with MS showed significant postoperative impairment in a subtest for auditory-verbal memory (Wechsler Memory Scale, Fourth Edition, Logical Memory II; MS vs. EV P = 0.011). The MS group trended toward posttreatment impairment in subtests for verbal fluency and semantic memory (Regensburg Word Fluency Test; MS vs. EV P = 0.083) and in auditory-verbal memory (Wechsler Memory Scale, Fourth Edition, Logical Memory II; MS vs. LD P = 0.06). Our preliminary data showed no effect of anterior circulation UIA treatment on overall neuropsychological function but impaired

Preliminary study for small animal preclinical hadrontherapy facility

Energy Technology Data Exchange (ETDEWEB)

Russo, G. [Institute of Molecular Bioimaging and Physiology, IBFM CNR-LATO, Cefalú (Italy); Pisciotta, P., E-mail: pietro.pisciotta@ibfm.cnr.it [Institute of Molecular Bioimaging and Physiology, IBFM CNR-LATO, Cefalú (Italy); National Institute for Nuclear Physics, Laboratori Nazionali del Sud, INFN-LNS, Catania (Italy); Cirrone, G.A.P.; Romano, F. [National Institute for Nuclear Physics, Laboratori Nazionali del Sud, INFN-LNS, Catania (Italy); Cammarata, F.; Marchese, V.; Forte, G.I.; Lamia, D.; Minafra, L.; Bravatá, V. [Institute of Molecular Bioimaging and Physiology, IBFM CNR-LATO, Cefalú (Italy); Acquaviva, R. [University of Catania, Catania (Italy); Gilardi, M.C. [Institute of Molecular Bioimaging and Physiology, IBFM CNR-LATO, Cefalú (Italy); Cuttone, G. [National Institute for Nuclear Physics, Laboratori Nazionali del Sud, INFN-LNS, Catania (Italy)

2017-02-21

Aim of this work is the study of the preliminary steps to perform a particle treatment of cancer cells inoculated in small animals and to realize a preclinical hadrontherapy facility. A well-defined dosimetric protocol was developed to explicate the steps needed in order to perform a precise proton irradiation in small animals and achieve a highly conformal dose into the target. A precise homemade positioning and holding system for small animals was designed and developed at INFN-LNS in Catania (Italy), where an accurate Monte Carlo simulation was developed, using Geant4 code to simulate the treatment in order to choose the best animal position and perform accurately all the necessary dosimetric evaluations. The Geant4 application can also be used to realize dosimetric studies and its peculiarity consists in the possibility to introduce the real target composition in the simulation using the DICOM micro-CT image. This application was fully validated comparing the results with the experimental measurements. The latter ones were performed at the CATANA (Centro di AdroTerapia e Applicazioni Nucleari Avanzate) facility at INFN-LNS by irradiating both PMMA and water solid phantom. Dosimetric measurements were performed using previously calibrated EBT3 Gafchromic films as a detector and the results were compared with the Geant4 simulation ones. In particular, two different types of dosimetric studies were performed: the first one involved irradiation of a phantom made up of water solid slabs where a layer of EBT3 was alternated with two different slabs in a sandwich configuration, in order to validate the dosimetric distribution. The second one involved irradiation of a PMMA phantom made up of a half hemisphere and some PMMA slabs in order to simulate a subcutaneous tumour configuration, normally used in preclinical studies. In order to evaluate the accordance between experimental and simulation results, two different statistical tests were made: Kolmogorov test and

Preliminary study for small animal preclinical hadrontherapy facility

Science.gov (United States)

Russo, G.; Pisciotta, P.; Cirrone, G. A. P.; Romano, F.; Cammarata, F.; Marchese, V.; Forte, G. I.; Lamia, D.; Minafra, L.; Bravatá, V.; Acquaviva, R.; Gilardi, M. C.; Cuttone, G.

2017-02-01

Aim of this work is the study of the preliminary steps to perform a particle treatment of cancer cells inoculated in small animals and to realize a preclinical hadrontherapy facility. A well-defined dosimetric protocol was developed to explicate the steps needed in order to perform a precise proton irradiation in small animals and achieve a highly conformal dose into the target. A precise homemade positioning and holding system for small animals was designed and developed at INFN-LNS in Catania (Italy), where an accurate Monte Carlo simulation was developed, using Geant4 code to simulate the treatment in order to choose the best animal position and perform accurately all the necessary dosimetric evaluations. The Geant4 application can also be used to realize dosimetric studies and its peculiarity consists in the possibility to introduce the real target composition in the simulation using the DICOM micro-CT image. This application was fully validated comparing the results with the experimental measurements. The latter ones were performed at the CATANA (Centro di AdroTerapia e Applicazioni Nucleari Avanzate) facility at INFN-LNS by irradiating both PMMA and water solid phantom. Dosimetric measurements were performed using previously calibrated EBT3 Gafchromic films as a detector and the results were compared with the Geant4 simulation ones. In particular, two different types of dosimetric studies were performed: the first one involved irradiation of a phantom made up of water solid slabs where a layer of EBT3 was alternated with two different slabs in a sandwich configuration, in order to validate the dosimetric distribution. The second one involved irradiation of a PMMA phantom made up of a half hemisphere and some PMMA slabs in order to simulate a subcutaneous tumour configuration, normally used in preclinical studies. In order to evaluate the accordance between experimental and simulation results, two different statistical tests were made: Kolmogorov test and

Preliminary study for small animal preclinical hadrontherapy facility

International Nuclear Information System (INIS)

Russo, G.; Pisciotta, P.; Cirrone, G.A.P.; Romano, F.; Cammarata, F.; Marchese, V.; Forte, G.I.; Lamia, D.; Minafra, L.; Bravatá, V.; Acquaviva, R.; Gilardi, M.C.; Cuttone, G.

2017-01-01

Aim of this work is the study of the preliminary steps to perform a particle treatment of cancer cells inoculated in small animals and to realize a preclinical hadrontherapy facility. A well-defined dosimetric protocol was developed to explicate the steps needed in order to perform a precise proton irradiation in small animals and achieve a highly conformal dose into the target. A precise homemade positioning and holding system for small animals was designed and developed at INFN-LNS in Catania (Italy), where an accurate Monte Carlo simulation was developed, using Geant4 code to simulate the treatment in order to choose the best animal position and perform accurately all the necessary dosimetric evaluations. The Geant4 application can also be used to realize dosimetric studies and its peculiarity consists in the possibility to introduce the real target composition in the simulation using the DICOM micro-CT image. This application was fully validated comparing the results with the experimental measurements. The latter ones were performed at the CATANA (Centro di AdroTerapia e Applicazioni Nucleari Avanzate) facility at INFN-LNS by irradiating both PMMA and water solid phantom. Dosimetric measurements were performed using previously calibrated EBT3 Gafchromic films as a detector and the results were compared with the Geant4 simulation ones. In particular, two different types of dosimetric studies were performed: the first one involved irradiation of a phantom made up of water solid slabs where a layer of EBT3 was alternated with two different slabs in a sandwich configuration, in order to validate the dosimetric distribution. The second one involved irradiation of a PMMA phantom made up of a half hemisphere and some PMMA slabs in order to simulate a subcutaneous tumour configuration, normally used in preclinical studies. In order to evaluate the accordance between experimental and simulation results, two different statistical tests were made: Kolmogorov test and

Characteristics of Labial Gland Mesenchymal Stem Cells of Healthy Individuals and Patients with Sjögren's Syndrome: A Preliminary Study.

Science.gov (United States)

Wang, Shi-Qin; Wang, Yi-Xiang; Hua, Hong

2017-08-15

Sjögren's syndrome (SS) is a systemic autoimmune disease that is characterized by focal lymphocytic infiltration into exocrine organs such as salivary and lacrimal glands, resulting in dry mouth and eyes, and other systemic injuries. There is no curative clinical therapy for SS, and stem cell therapy has shown great potential in this area. The mesenchymal stem cells (MSCs) in the salivary glands of healthy individuals and in patients with SS have not been extensively studied. The aim of this study was to elucidate the characteristics of MSCs from the labial glands of healthy controls and of those from patients with SS to elucidate the related pathogenesis and to uncover potential avenues for novel clinical interventions. Labial glands from patients with SS and healthy subjects were obtained, and MSCs were isolated and cultured by using the tissue adherent method. The MSC characteristics of the cultured cells were confirmed by using morphology, proliferation, colony forming-unit (CFU) efficiency, and multipotentiality, including osteogenic, adipogenic, and salivary gland differentiation. The MSCs from the healthy controls and SS patients expressed characteristic MSC markers, including CD29, CD44, CD73, CD90, and CD105; they were negative for CD34, CD45, and CD106, and also negative for the salivary gland epithelium markers (CD49f and CD117). Labial gland MSCs from both groups were capable of osteogenic and adipogenic differentiation. The CFU efficiency and adipogenic differentiation potential of MSCs were significantly lower in the SS group compared with the healthy controls. Cells from both groups could also be induced into salivary gland-like cells. Real-time polymerase chain reaction and immunofluorescence staining showed that the gene and protein expression of AMY1, AQP5, and ZO-1 in cells from the SS group was lower than that in cells from the healthy group. Thus, MSCs from the labial glands in patients with SS could lack certain characteristics and functions

Gravity-Based Precise Cell Manipulation System Enhanced by In-Phase Mechanism

Directory of Open Access Journals (Sweden)

Koji Mizoue

2016-07-01

Full Text Available This paper proposes a gravity-based system capable of generating high-resolution pressure for precise cell manipulation or evaluation in a microfluidic channel. While the pressure resolution of conventional pumps for microfluidic applications is usually about hundreds of pascals as the resolution of their feedback sensors, precise cell manipulation at the pascal level cannot be done. The proposed system successfully achieves a resolution of 100 millipascals using water head pressure with an in-phase noise cancelation mechanism. The in-phase mechanism aims to suppress the noises from ambient vibrations to the system. The proposed pressure system is tested with a microfluidic platform for pressure validation. The experimental results show that the in-phase mechanism effectively reduces the pressure turbulence, and the pressure-driven cell movement matches the theoretical simulations. Preliminary experiments on deformability evaluation with red blood cells under incremental pressures of one pascal are successfully performed. Different deformation patterns are observed from cell to cell under precise pressure control.

Preliminary report on the experiment performed in MARIUS reactor loaded with teledial fuel

Energy Technology Data Exchange (ETDEWEB)

Estiot, J C; Morier, F

1972-06-15

The experimental work described in this paper is part of a collaborative programme agreed between CEA and the Dragon Project. The aim of the programme is the measurement of the relative conversion ratio in a reactor loaded with Teledial fuel elements. The results will allow us to check our calculational methods and assumptions upon which the calculations are based, in the case of a teledial core, which represents a very complicated geometry, specially, due to the presence of the U238 with its resonance. The programme of experiments described in the paper have been completed. Some preliminary results are presented in the second part of this report (Part 2).

Preliminary test results for post irradiation examination on the HTTR fuel

International Nuclear Information System (INIS)

Ueta, Shohei; Umeda, Masayuki; Sawa, Kazuhiro; Sozawa, Shizuo; Shimizu, Michio; Ishigaki, Yoshinobu; Obata, Hiroyuki

2007-01-01

The future post-irradiation program for the first-loading fuel of the HTTR is scheduled using the HTTR fuel handling facilities and the Hot Laboratory in the Japan Materials Testing Reactor (JMTR) to confirm its irradiation resistance and to obtain data on its irradiation characteristics in the core. This report describes the preliminary test results and the future plan for a post-irradiation examination for the HTTR fuel. In the preliminary test, fuel compacts made with the same SiC-coated fuel particle as the first loading fuel were used. In the preliminary test, dimension, weight, fuel failure fraction, and burnup were measured, and X-ray radiograph, SEM, and EPMA observations were carried out. Finally, it was confirmed that the first-loading fuel of the HTTR showed good quality under an irradiation condition. The future plan for the post-irradiation tests was described to confirm its irradiation performance and to obtain data on its irradiation characteristics in the HTTR core. (author)

Preliminary Study of a Piston Pump for Cryogenic Fluids

Science.gov (United States)

Biermann, Arnold E.; Kohl, Robert C.

1959-01-01

Preliminary data are presented covering the performance of a low-speed, five-cylinder piston pump designed for handling boiling hydrogen. This pump was designed for a flow of 55 gallons per minute at 240 rpm with a discharge pressure of 135 pounds per square inch. Tests were made using JP-4 fuel, liquid nitrogen, and liquid hydrogen. Pump delivery and endurance characteristics were satisfactory for the range of operation covered. In connection with the foregoing pump development, the cavitation characteristics of a preliminary visual model, glass-cylinder pump and of a simple reciprocating disk were studied. Subcooling of approximately 0.60 F was obtained from the cavitation produced by reciprocating a disk in boiling nitrogen and in boiling water. The subcooling obtained in a similar manner with liquid hydrogen was somewhat less.

Purification, crystallization and preliminary X-ray diffraction studies of parakeet (Psittacula krameri) haemoglobin

International Nuclear Information System (INIS)

Jaimohan, S. M.; Naresh, M. D.; Arumugam, V.; Mandal, A. B.

2009-01-01

Parakeet (Psittacula krameri) haemoglobin has been purified and crystallized under low salt buffered conditions. Preliminary analysis of the crystal that belonged to monoclinic system (C2) is reported. Birds often show efficient oxygen management in order to meet the special demands of their metabolism. However, the structural studies of avian haemoglobins (Hbs) are inadequate for complete understanding of the mechanism involved. Towards this end, purification, crystallization and preliminary X-ray diffraction studies have been carried out for parakeet Hb. Parakeet Hb was crystallized as the met form in low-salt buffered conditions after extracting haemoglobin from crude blood by microcentrifugation and purifying the sample by column chromatography. Good-quality crystals were grown from 10% PEG 3350 and a crystal diffracted to about 2.8 Å resolution. Preliminary diffraction data showed that the Hb crystal belonged to the monoclinic system (space group C2), with unit-cell parameters a = 110.68, b = 64.27, c = 56.40 Å, β = 109.35°. Matthews volume analysis indicated that the crystals contained a half-tetramer in the asymmetric unit

Expression, purification, crystallization and preliminary X-ray analysis of Aeromonas hydrophilia metallo-β-lactamase

Energy Technology Data Exchange (ETDEWEB)

Sharma, Nandini, E-mail: nandini-sharma@merck.com; Toney, Jeffrey H.; Fitzgerald, Paula M. D.

2005-02-01

Crystallization and preliminary X-ray analysis of the CphA metallo-β-lactamase from A. hydrophilia are described. The crystals belonged to space group P2{sub 1}2{sub 1}2, with unit-cell parameters a = 40.75, b = 42.05, c = 128.88 Å, and diffract to 1.8 Å.

Experimental and theoretical analysis of cell module output performance for a thermophotovoltaic system

International Nuclear Information System (INIS)

Xu, Xiaojie; Ye, Hong; Xu, Yexin; Shen, Mingrong; Zhang, Xiaojing; Wu, Xi

2014-01-01

Highlights: • An accurate theoretical model for thermophotovoltaic system is constructed. • Parallel connected module is superior if radiator temperature is uneven. • Series connected module is superior if cell temperature is uneven. • Short circuit current of series module rises when the shunt resistance decreases. • Fill factor is not always accurate to evaluate the module performance. - Abstract: An experimental thermophotovoltaic (TPV) system with a cylindrical-geometry radiator was established to test the output performances of modules under different conditions. The results demonstrate that the output performance of a cell module decreases when the combustion power increases because of the uneven temperature of the radiator or cells. On this basis, a theoretical model for a TPV system was constructed to compare the performance under different conditions of the series-connected (SC) module and the parallel-connected (PC) module, and was verified by the experimental results. The influences of the temperature gradient of the radiator or the cell module, and the series and shunt resistance of the TPV cell on the module performance were analyzed in detail. The results demonstrate that the PC module can effectively reduce the mismatch loss of output power caused by the uneven radiator temperature. The PC module, for instance, has a maximum output power of 2.54 times higher than that of the SC module when the radiator temperature difference is 500 K. However, the output performance of the module connected in series is superior to the PC module while the cell temperature is non-uniform. The output power of the SC module is 9.93% higher than that of the PC module at the cell temperature difference of 125 K. The short circuit current of the SC module is sensitive to the series and shunt resistance if the radiator temperature distribution is non-uniform. As the shunt resistance falls from ∞ to 0.5 Ω, the current varies from 1.757 A to 4.488 A when the

A Preliminary Study of Human Amniotic Membrane as a Potential Chondrocyte Carrier

Directory of Open Access Journals (Sweden)

L Boo

2009-11-01

Full Text Available PURPOSE: To investigate the feasibility of using processed human amniotic membrane (HAM to support the attachment and proliferation of chondrocytes in vitro which in turn can be utilised as a cell delivery vehicle in tissue engineering applications. METHODS: Fresh HAM obtained from patients undergoing routine elective caesarean sections was harvested, processed and dried using either freeze drying (FD or air drying (AD methods prior to sterilisation by gamma irradiation. Isolated, processed and characterised rabbit autologous chondrocytes were seeded on processed HAM and cultured for up to three weeks. Cell attachment and proliferation were examined qualitatively using inverted brightfield microscopy. RESULTS: Processed HAM appeared to allow cell attachment when implanted with chondrocytes. Although cells seeded on AD and FD HAM did not appear to attach as strongly as those seeded on glycerol preserved intact human amniotic membrane, these cells to be proliferated in cell culture conditions. CONCLUSION: Preliminary results show that processed HAM promotes chondrocyte attachment and proliferation.

High Performance Biological Pairwise Sequence Alignment: FPGA versus GPU versus Cell BE versus GPP

Directory of Open Access Journals (Sweden)

Khaled Benkrid

2012-01-01

Full Text Available This paper explores the pros and cons of reconfigurable computing in the form of FPGAs for high performance efficient computing. In particular, the paper presents the results of a comparative study between three different acceleration technologies, namely, Field Programmable Gate Arrays (FPGAs, Graphics Processor Units (GPUs, and IBM’s Cell Broadband Engine (Cell BE, in the design and implementation of the widely-used Smith-Waterman pairwise sequence alignment algorithm, with general purpose processors as a base reference implementation. Comparison criteria include speed, energy consumption, and purchase and development costs. The study shows that FPGAs largely outperform all other implementation platforms on performance per watt criterion and perform better than all other platforms on performance per dollar criterion, although by a much smaller margin. Cell BE and GPU come second and third, respectively, on both performance per watt and performance per dollar criteria. In general, in order to outperform other technologies on performance per dollar criterion (using currently available hardware and development tools, FPGAs need to achieve at least two orders of magnitude speed-up compared to general-purpose processors and one order of magnitude speed-up compared to domain-specific technologies such as GPUs.

Preliminary X-ray crystallographic analysis of the glycosyltransferase from a marine Streptomyces species

International Nuclear Information System (INIS)

Gong, Liping; Xiao, Yi; Liu, Qiang; Li, Sumei; Zhang, Changsheng; Liu, Jinsong

2010-01-01

The recombinant glycosyltransferase ElaGT from the elaiophylin-producing marine Streptomyces sp. SCSIO 01934 has been overexpressed in E. coli, purified and crystallized. Diffraction data were collected to 2.9 Å resolution. ElaGT is a glycosyltransferase from a marine Streptomyces species that is involved in the biosynthesis of elaiophylin. Here, the molecular cloning, protein expression and purification, preliminary crystallization and crystallographic characterization of ElaGT are reported. The rod-shaped crystals belonged to space group P2 1 22, with unit-cell parameters a = 66.7, b = 131.7, c = 224.6 Å, α = 90, β = 90, γ = 90°. Data were collected to 2.9 Å resolution. A preliminary molecular-replacement solution implied the presence of two ElaGT molecules in the asymmetric unit

Cell-element simulations to optimize the performance of osmotic processes in porous membranes

KAUST Repository

Calo, Victor M.; Iliev, Oleg; Nunes, Suzana Pereira; Printsypar, Galina; Shi, Meixia

2018-01-01

concerns the design of a cell element for the forward osmosis experiments. Using the developed software tool we qualitatively and quantitatively investigate the performance of a cell element that we designed for laboratory experiments of forward osmosis

Hydraulically driven control rod concept for integral reactors: fluid dynamic simulation and preliminary test

International Nuclear Information System (INIS)

Ricotti, M.E.; Cammi, A.; Lombardi, C.; Passoni, M.; Rizzo, C.; Carelli, M.; Colombo, E.

2003-01-01

The paper deals with the preliminary study of the Hydraulically Driven Control Rod concept, tailored for PWR control rods (spider type) with hydraulic drive mechanism completely immersed in the primary water. A specific solution suitable for advanced versions of the IRIS integral reactor is under investigation. The configuration of the Hydraulic Control Rod device, made up by an external movable piston and an internal fixed cylinder, is described. After a brief description of the whole control system, particular attention is devoted to the Control Rod characterization via Computational Fluid Dynamics (CFD) analysis. The investigation of the system behavior, including dynamic equilibrium and stability properties, has been carried out. Finally, preliminary tests were performed in a low pressure, low temperature, reduced length experimental facility. The results are compared with the dynamic control model and CFD simulation model, showing good agreement between simulations and experimental data. During these preliminary tests, the control system performs correctly, allowing stable dynamic equilibrium positions for the Control Rod and stable behavior during withdrawal and insertion steps. (author)

The donor-supply electrode enhances performance in colloidal quantum dot solar cells

KAUST Repository

Maraghechi, Pouya

2013-07-23

Colloidal quantum dot (CQD) solar cells combine solution-processability with quantum-size-effect tunability for low-cost harvesting of the sun\\'s broad visible and infrared spectrum. The highest-performing colloidal quantum dot solar cells have, to date, relied on a depleted-heterojunction architecture in which an n-type transparent metal oxide such as TiO2 induces a depletion region in the p-type CQD solid. These devices have, until now, been limited by a modest depletion region depth produced in the CQD solid owing to limitations in the doping available in TiO2. Herein we report a new device geometry - one based on a donor-supply electrode (DSE) - that leads to record-performing CQD photovoltaic devices. Only by employing this new charge-extracting approach do we deepen the depletion region in the CQD solid and thereby extract notably more photocarriers, the key element in achieving record photocurrent and device performance. With the use of optoelectronic modeling corroborated by experiment, we develop the guidelines for building a superior CQD solar cell based on the DSE concept. We confirm that using a shallow-work-function terminal electrode is essential to producing improved charge extraction and enhanced performance. © 2013 American Chemical Society.

Preliminary screening and identification of the hepatocarcinoma cell-binding peptide

International Nuclear Information System (INIS)

Zhu Xiaohua; Wu Hua

2004-01-01

Objective: To explore the feasibility of screening and isolating homing peptides that bind specifically, or preferentially, to hepatocarcinoma cells using phage display random peptide library and to develop a new peptide which may be potentially used as targeting delivery carrier in the biological targeted diagnosis or therapy for liver cancer. Methods: A 12-mer peptide phage display library was used to screen and isolate peptides that bind to human hepatocarcinoma cells, and four rounds of subtractive panning were carried out with the human hepatocarcinoma cell line HepG2 as the target. The affinities of selected phage clones for human hepatocarcinoma cells were determined with enzyme-linked immunosorbent assay (ELISA) and compared with that to human liver cell and other tumor cells of different tissue origins, respectively. In addition, the binding site in the tumor cells was observed with immunofluorescence analysis under confocal light microscopy. The amino acid sequences of phages that bind HepG2 specifically were deduced through DNA sequencing. Based on the results of DNA sequence, a 16-mer peptide (WH16) was designed and synthesized. Binding ability of the new peptide, WH16, was determined with competitive inhibition test. Results: After four rounds of panning, the phages that were bound to and internalized in human hepatocarcinoma cells were isolated. ELISA and immunofluorescence analysis confirmed the affinity of these phages for hepatocarcinoma cells. 56.67%(17/30) of the isolated phages displayed repeated sequence FLLEPHLMDTSM, and FLEP was defined as conservative motif . Binding of the selected phage to HepG2 cells was inhibited by synthesized peptide WH16, that strongly support that cellular binding of the phage is mediated through its displayed peptide, and WH16 can also bind to HepG2. Conclusions: It is feasible to screen and isolate homing peptides that bind specifically, or preferentially, to hepatocarcinoma cells using phage display random peptide

Preliminary screening and identification of the hepatocarcinoma cell-binding peptide

Energy Technology Data Exchange (ETDEWEB)

Xiaohua, Zhu; Hua, Wu [Department of Nuclear Medicine, Tongji Hospital, Tongji Medical College, Huazhong Univ. of Science and Technology, Wuhan (China)

2004-12-15

Objective: To explore the feasibility of screening and isolating homing peptides that bind specifically, or preferentially, to hepatocarcinoma cells using phage display random peptide library and to develop a new peptide which may be potentially used as targeting delivery carrier in the biological targeted diagnosis or therapy for liver cancer. Methods: A 12-mer peptide phage display library was used to screen and isolate peptides that bind to human hepatocarcinoma cells, and four rounds of subtractive panning were carried out with the human hepatocarcinoma cell line HepG2 as the target. The affinities of selected phage clones for human hepatocarcinoma cells were determined with enzyme-linked immunosorbent assay (ELISA) and compared with that to human liver cell and other tumor cells of different tissue origins, respectively. In addition, the binding site in the tumor cells was observed with immunofluorescence analysis under confocal light microscopy. The amino acid sequences of phages that bind HepG2 specifically were deduced through DNA sequencing. Based on the results of DNA sequence, a 16-mer peptide (WH16) was designed and synthesized. Binding ability of the new peptide, WH16, was determined with competitive inhibition test. Results: After four rounds of panning, the phages that were bound to and internalized in human hepatocarcinoma cells were isolated. ELISA and immunofluorescence analysis confirmed the affinity of these phages for hepatocarcinoma cells. 56.67%(17/30) of the isolated phages displayed repeated sequence FLLEPHLMDTSM, and FLEP was defined as conservative motif . Binding of the selected phage to HepG2 cells was inhibited by synthesized peptide WH16, that strongly support that cellular binding of the phage is mediated through its displayed peptide, and WH16 can also bind to HepG2. Conclusions: It is feasible to screen and isolate homing peptides that bind specifically, or preferentially, to hepatocarcinoma cells using phage display random peptide

Determinants of academic performance in children with sickle cell anaemia.

Science.gov (United States)

Ezenwosu, Osita U; Emodi, Ifeoma J; Ikefuna, Anthony N; Chukwu, Barth F; Osuorah, Chidiebere D

2013-11-19

Some factors are known to influence the academic performance of children with Sickle Cell Anaemia (SCA). Information on their effects in these children is limited in Nigeria. The factors which influence academic performance of children with SCA in Enugu, Nigeria are determined in this study. Consecutive children with SCA aged 5-11 years were recruited at the weekly sickle cell clinic of the University of Nigeria Teaching Hospital (UNTH) Enugu, Nigeria. Their age- and sex- matched normal classmates were recruited as controls. The total number of days of school absence for 2009/2010 academic session was obtained for each pair of pupils from the class attendance register. Academic performance was assessed using the average of the overall scores in the three term examinations of same session. Intelligence ability was determined with Draw-A-Person Quotient (DAPQ) using the Draw-A-Person Test while socio-economic status was determined using the occupational status and educational attainment of each parent. Academic performance of children with SCA showed statistically significant association with their socio-economic status (χ2 = 9.626, p = 0.047), and significant correlation with DAPQ (r = 0.394, p = 0.000) and age (r = -0.412, p = 0.000). However, no significant relationship existed between academic performance and school absence in children with SCA (r = -0.080, p = 0.453). Academic performance of children with SCA is influenced by their intelligence ability, age and socio-economic status but not negatively affected by their increased school absenteeism.

Electric terminal performance and characterization of solid oxide fuel cells and systems

Science.gov (United States)

Lindahl, Peter Allan

Solid Oxide Fuel Cells (SOFCs) are electrochemical devices which can effect efficient, clean, and quiet conversion of chemical to electrical energy. In contrast to conventional electricity generation systems which feature multiple discrete energy conversion processes, SOFCs are direct energy conversion devices. That is, they feature a fully integrated chemical to electrical energy conversion process where the electric load demanded of the cell intrinsically drives the electrochemical reactions and associated processes internal to the cell. As a result, the cell's electric terminals provide a path for interaction between load side electric demand and the conversion side processes. The implication of this is twofold. First, the magnitude and dynamic characteristics of the electric load demanded of the cell can directly impact the long-term efficacy of the cell's chemical to electrical energy conversion. Second, the electric terminal response to dynamic loads can be exploited for monitoring the cell's conversion side processes and used in diagnostic analysis and degradation-mitigating control schemes. This dissertation presents a multi-tier investigation into this electric terminal based performance characterization of SOFCs through the development of novel test systems, analysis techniques and control schemes. First, a reference-based simulation system is introduced. This system scales up the electric terminal performance of a prototype SOFC system, e.g. a single fuel cell, to that of a full power-level stack. This allows realistic stack/load interaction studies while maintaining explicit ability for post-test analysis of the prototype system. Next, a time-domain least squares fitting method for electrochemical impedance spectroscopy (EIS) is developed for reduced-time monitoring of the electrochemical and physicochemical mechanics of the fuel cell through its electric terminals. The utility of the reference-based simulator and the EIS technique are demonstrated

Interface Engineering of Organic Schottky Barrier Solar Cells and Its Application in Enhancing Performances of Planar Heterojunction Solar Cells

OpenAIRE

Fangming Jin; Zisheng Su; Bei Chu; Pengfei Cheng; Junbo Wang; Haifeng Zhao; Yuan Gao; Xingwu Yan; Wenlian Li

2016-01-01

In this work, we describe the performance of organic Schottky barrier solar cells with the structure of ITO/molybdenum oxide (MoOx)/boron subphthalocyanine chloride (SubPc)/bathophenanthroline (BPhen)/Al. The SubPc-based Schottky barrier solar cells exhibited a short-circuit current density (Jsc) of 2.59?mA/cm2, an open-circuit voltage (Voc) of 1.06?V, and a power conversion efficiency (PCE) of 0.82% under simulated AM1.5?G solar illumination at 100?mW/cm2. Device performance was substantiall...

Performance Analysis of enhanced Inter-cell Interference Coordination in LTE-Advanced Heterogeneous Networks

DEFF Research Database (Denmark)

Wang, Yuanye; Pedersen, Klaus I.

2012-01-01

The performance of enhanced Inter-Cell Interference Coordination (eICIC) for Long Term Evolution (LTE)- Advanced with co-channel deployment of both macro and pico is analyzed. The use of pico-cell Range Extension (RE) and time domain eICIC (TDM muting) is combined. The performance is evaluated...... in the downlink by means of extensive system level simulations that follow the 3GPP guidelines. The overall network performance is analyzed for different number of pico-eNBs, transmit power levels, User Equipment (UE) distributions, and packet schedulers. Recommended settings of the RE offset and TDM muting ratio...... in different scenarios are identified. The presented performance results and findings can serve as input to guidelines for co-channel deployment of macro and pico-eNBs with eICIC....

The effect of material properties on the performance of a new geometry PEM fuel cell

Energy Technology Data Exchange (ETDEWEB)

Khazaee, Iman [Islamic Azad University, Department of Mechanical Engineering, Torbat-e-jam Branch, Torbat-e-jam (Iran, Islamic Republic of); Ghazikhani, Mohsen [Ferdowsi University of Mashhad, Department of Mechanical Engineering, Faculty of Engineering, Mashhad (Iran, Islamic Republic of)

2012-05-15

In this paper a computational dynamics model for duct-shaped geometry proton exchange membrane (PEM) fuel cell was used to investigate the effect of changing gas diffusion layer and membrane properties on the performances, current density and gas concentration. The proposed model is a full cell model, which includes all the parts of the PEM fuel cell, flow channels, gas diffusion electrodes, catalyst layers and the membrane. Coupled transport and electrochemical kinetics equations are solved in a single domain; therefore no interfacial boundary condition is required at the internal boundaries between cell components. This computational fluid dynamics code is used as the direct problem solver, which is used to simulate the 2-dimensional mass, momentum and species transport phenomena as well as the electron- and proton-transfer process taking place in a PEMFC that cannot be investigated experimentally. The results show that by increasing the thickness and decreasing the porosity of GDL the performance of the cell enhances that it is different with planner PEM fuel cell. Also the results show that by increasing the thermal conductivity of the GDL and membrane, the overall cell performance increases. (orig.)

Preparation and performance of intermediate-temperature fuel cells based on Gd-doped ceria electrolytes with different compositions

International Nuclear Information System (INIS)

Li, Zhimin; Mori, Toshiyuki; Yan, Pengfei; Wu, Yuanyuan; Li, ZhiPeng

2012-01-01

Highlights: ► Gd 0.1 Ce 0.9 O 1.95 electrolyte had less density of oxygen vacancies ordering. ► Gd 0.2 Ce 0.8 O 1.9 fuel cell showed better performance than Gd 0.1 Ce 0.9 O 1.95 . ► The relationship between microstructures and performance for cells were discussed. ► Gd 0.2 Ce 0.8 O 1.9 electrolyte with higher grain boundary conductivity was concluded. - Abstract: In this work, the effect of two frequently used Gd x Ce 1−x O 2−x/2 electrolytes (x = 0.1 and x = 0.2) on the performance of fuel cells operated at intermediate temperature was studied. The microstructures of ceria electrolytes responsible for the performance were discussed. Electrochemical measurements of as-prepared cells showed that the cell with Gd 0.2 Ce 0.8 O 1.9 electrolyte had a better performance than that of Gd 0.1 Ce 0.9 O 1.95 . It can be concluded that the increase of grain boundary conductivity of Gd 0.2 Ce 0.8 O 1.9 electrolyte contributes to its better cell performance.

Testing And Performance Analysis Of NASA 5 CM BY 5 CM Bi-Supported Solid Oxide Electrolysis Cells Operated In Both Fuel Cell And Steam Electrolysis Modes

International Nuclear Information System (INIS)

O'Brien, R.C.; O'Brien, J.E.; Stoots, C.M.; Zhang, X.; Farmer, S.C.; Cable, T.L.; Setlock, J.A.

2011-01-01

A series of 5 cm by 5 cm bi-supported Solid Oxide Electrolysis Cells (SOEC) were produced by NASA for the Idaho National Laboratory (INL) and tested under the INL High Temperature Steam Electrolysis program. The results from the experimental demonstration of cell operation for both hydrogen production and operation as fuel cells is presented. An overview of the cell technology, test apparatus and performance analysis is also provided. The INL High Temperature Steam Electrolysis laboratory has developed significant test infrastructure in support of single cell and stack performance analyses. An overview of the single cell test apparatus is presented. The test data presented in this paper is representative of a first batch of NASA's prototypic 5 cm by 5 cm SOEC single cells. Clearly a significant relationship between the operational current density and cell degradation rate is evident. While the performance of these cells was lower than anticipated, in-house testing at NASA Glenn has yielded significantly higher performance and lower degradation rates with subsequent production batches of cells. Current post-test microstructure analyses of the cells tested at INL will be published in a future paper. Modification to cell compositions and cell reduction techniques will be altered in the next series of cells to be delivered to INL with the aim to decrease the cell degradation rate while allowing for higher operational current densities to be sustained. Results from the testing of new batches of single cells will be presented in a future paper.

Nb/NiCu bilayers in single and stacked superconductive tunnel junctions: preliminary results

International Nuclear Information System (INIS)

Pepe, G.P.; Ruotolo, A.; Parlato, L.; Peluso, G.; Ausanio, G.; Carapella, G.; Latempa, R.

2004-01-01

We present preliminary experimental results concerning both single and stacked tunnel junctions in which one of the electrodes was formed by a superconductor/ferromagnet (S/F) bi-layer. In particular, in the stacked configuration a Nb/NiCu bi-layer was used as the intermediate electrode, and it was probed by tunneling on both sides. Tunnel junctions have been characterized in terms of current-voltage characteristics (IVC), and differential conductance. Preliminary steady-state injection-detection measurements performed in the stacked devices at T=4.2 K are also presented and discussed

Crystallization and preliminary X-ray structural studies of a Melan-A pMHC–TCR complex

International Nuclear Information System (INIS)

Yuan, Fang; Georgiou, Theonie; Hillon, Theresa; Gostick, Emma; Price, David A.; Sewell, Andrew K.; Moysey, Ruth; Gavarret, Jessie; Vuidepot, Annelise; Sami, Malkit; Bell, John I.; Gao, George F.; Rizkallah, Pierre J.; Jakobsen, Bent K.

2007-01-01

A preliminary X-ray crystal structural study of a soluble cognate T-cell receptor (TCR) in complex with a pMHC presenting the Melan-A peptide (ELAGIGILTV) is reported. The TCR and pMHC were refolded, purified and mixed together to form complexes, which were crystallized using the sitting-drop vapour-diffusion method. Single TCR–pMHC complex crystals were cryocooled and used for data collection. Melanocytes are specialized pigmented cells that are found in all healthy skin tissue. In certain individuals, diseased melanocytes can form malignant tumours, melanomas, which cause the majority of skin-cancer-related deaths. The melanoma-associated antigenic peptides are presented on cell surfaces via the class I major histocompatibility complex (MHC). Among the melanoma-associated antigens, the melanoma self-antigen A/melanoma antigen recognized by T cells (Melan-A/MART-1) has attracted attention because of its wide expression in primary and metastatic melanomas. Here, a preliminary X-ray crystal structural study of a soluble cognate T-cell receptor (TCR) in complex with a pMHC presenting the Melan-A peptide (ELAGIGILTV) is reported. The TCR and pMHC were refolded, purified and mixed together to form complexes, which were crystallized using the sitting-drop vapour-diffusion method. Single TCR–pMHC complex crystals were cryocooled and used for data collection. Diffraction data showed that these crystals belonged to space group P4 1 /P4 3 , with unit-cell parameters a = b = 120.4, c = 81.6 Å. A complete data set was collected to 3.1 Å and the structure is currently being analysed

Experimental-demonstrative system for energy conversion using hydrogen fuel cell - preliminary results

International Nuclear Information System (INIS)

Stoenescu, D.; Stefanescu, I.; Patularu, I.; Culcer, M.; Lazar, R.E.; Carcadea, E.; Mirica, D. . E-mail address of corresponding author: daniela@icsi.ro; Stoenescu, D.)

2005-01-01

It is well known that hydrogen is the most promising solution of future energy, both for long and medium term strategies. Hydrogen can be produced using many primary sources (natural gas, methane, biomass, etc.), it can be burned or chemically react having a high yield of energy conversion, being a non-polluted fuel. This paper presents the preliminary results obtained by ICSI Rm. Valcea in an experimental-demonstrative conversion energy system made by a sequence of hydrogen purification units and a CO removing reactors until a CO level lower than 10ppm, that finally feeds a hydrogen fuel stack. (author)

Experimental analysis of performance degradation of micro-tubular solid oxide fuel cells fed by different fuel mixtures

Science.gov (United States)

Calise, F.; Restucccia, G.; Sammes, N.

This paper analyzes the thermodynamic and electrochemical dynamic performance of an anode supported micro-tubular solid oxide fuel cell (SOFC) fed by different types of fuel. The micro-tubular SOFC used is anode supported, consisting of a NiO and Gd 0.2Ce 0.8O 2- x (GDC) cermet anode, thin GDC electrolyte, and a La 0.6Sr 0.4Co 0.2Fe 0.8O 3- y (LSCF) and GDC cermet cathode. The fabrication of the cells under investigation is briefly summarized, with emphasis on the innovations with respect to traditional techniques. Such micro-tubular cells were tested using a Test Stand consisting of: a vertical tubular furnace, an electrical load, a galvanostast, a bubbler, gas pipelines, temperature, pressure and flow meters. The tests on the micro-SOFC were performed using H 2, CO, CH 4 and H 2O in different combinations at 550 °C, to determine the cell polarization curves under several load cycles. Long-term experimental tests were also performed in order to assess degradation of the electrochemical performance of the cell. Results of the tests were analyzed aiming at determining the sources of the cell performance degradation. Authors concluded that the cell under investigation is particularly sensitive to the carbon deposition which significantly reduces cell performance, after few cycles, when fed by light hydrocarbons. A significant performance degradation is also detected when hydrogen is used as fuel. In this case, the authors ascribe the degradation to the micro-cracks, the change in materials crystalline structure and problems with electrical connections.

Characterization and fuel cell performance analysis of polyvinylalcohol-mordenite mixed-matrix membranes for direct methanol fuel cell use

Energy Technology Data Exchange (ETDEWEB)

Uctug, Fehmi Goerkem, E-mail: gorkem.uctug@bahcesehir.edu.t [University of Manchester, School of Chemical Engineering and Analytical Science, M60 1QD (United Kingdom); Holmes, Stuart M. [University of Manchester, School of Chemical Engineering and Analytical Science, M60 1QD (United Kingdom)

2011-10-01

Highlights: > We investigated the availability of PVA-mordenite membranes for DMFC use. > We measured the methanol permeability of PVA-mordenite membranes via pervaporation. > We did the fuel cell testing of these membranes, which had not been done before. > We showed that PVA-mordenite membranes have poorer DMFC performance than Nafion. > Membrane performance can be improved by increasing the proton conductivity of PVA. - Abstract: Polyvinylalcohol-mordenite (PVA-MOR) mixed matrix membranes were synthesized for direct methanol fuel cell (DMFC) use. For the structural and the morphological characterization, Scanning Electron Microscopy and Thermal Gravimetric Analysis methods were used. Zeolite distribution within the polymer matrix was found to be homogeneous. An impedance spectroscope was used to measure the proton conductivity. In order to obtain information about methanol permeation characteristics, swelling tests and a series of pervaporation experiments were carried out. 60-40 wt% PVA-MOR membranes were found to give the optimum transport properties. Proton conductivity of these membranes was found to be slightly lower than that of Nafion117{sup TM} whereas their methanol permeability was at least two orders of magnitude lower than Nafion117{sup TM}. DMFC performance of the PVA-MOR membranes was also measured. The inferior DMFC performance of PVA-MOR membranes was linked to drying in the fuel cell medium and the consequent proton conductivity loss. Their performance was improved by adding a dilute solution of sulfuric acid into the feed methanol solution. Future studies on the improvement of the proton conductivity of PVA-MOR membranes, especially via sulfonation of the polymer matrix, can overcome the low-performance problem associated with insufficient proton conductivity.

Characterization and fuel cell performance analysis of polyvinylalcohol-mordenite mixed-matrix membranes for direct methanol fuel cell use

International Nuclear Information System (INIS)

Uctug, Fehmi Goerkem; Holmes, Stuart M.

2011-01-01

Highlights: → We investigated the availability of PVA-mordenite membranes for DMFC use. → We measured the methanol permeability of PVA-mordenite membranes via pervaporation. → We did the fuel cell testing of these membranes, which had not been done before. → We showed that PVA-mordenite membranes have poorer DMFC performance than Nafion. → Membrane performance can be improved by increasing the proton conductivity of PVA. - Abstract: Polyvinylalcohol-mordenite (PVA-MOR) mixed matrix membranes were synthesized for direct methanol fuel cell (DMFC) use. For the structural and the morphological characterization, Scanning Electron Microscopy and Thermal Gravimetric Analysis methods were used. Zeolite distribution within the polymer matrix was found to be homogeneous. An impedance spectroscope was used to measure the proton conductivity. In order to obtain information about methanol permeation characteristics, swelling tests and a series of pervaporation experiments were carried out. 60-40 wt% PVA-MOR membranes were found to give the optimum transport properties. Proton conductivity of these membranes was found to be slightly lower than that of Nafion117 TM whereas their methanol permeability was at least two orders of magnitude lower than Nafion117 TM . DMFC performance of the PVA-MOR membranes was also measured. The inferior DMFC performance of PVA-MOR membranes was linked to drying in the fuel cell medium and the consequent proton conductivity loss. Their performance was improved by adding a dilute solution of sulfuric acid into the feed methanol solution. Future studies on the improvement of the proton conductivity of PVA-MOR membranes, especially via sulfonation of the polymer matrix, can overcome the low-performance problem associated with insufficient proton conductivity.

Effect of junction quality on the performance of a silicon solar cell ...

African Journals Online (AJOL)

In this work, a modeling study of the effect of the junction quality on the performance of a silicon solar cell is presented. Based on a one dimensional modeling of the solar cell, the continuity equation of excess minority carriers is solved with boundary conditions taking into account the intrinsic junction recombination velocity ...

High Performance Nano-Ceria Electrodes for Solid Oxide Cells

DEFF Research Database (Denmark)

Graves, Christopher R.; Martinez Aguilera, Lev; Sudireddy, Bhaskar Reddy

2016-01-01

forming the active surfaces on a porous backbone with embedded electronic current collector material, yielding one of the highest performances reported for an electrode that operates either on fuel or oxidant. The second is a nano-Ce0.9Gd0.1O2-δ thin film prepared by spin-coating, which provides......In solid oxide electrochemical cells, the conventional Ni-based fuel-electrodes provide high electrocatalytic activity but they are often a major source of long-term performance degradation due to carbon deposition, poisoning of reaction sites, Ni mobility, etc. Doped-ceria is a promising mixed...

CDTE alloys and their application for increasing solar cell performance

Science.gov (United States)

Swanson, Drew E.

Cadmium Telluride (CdTe) thin film solar is the largest manufactured solar cell technology in the United States and is responsible for one of the lowest costs of utility scale solar electricity at a purchase agreement of $0.0387/kWh. However, this cost could be further reduced by increasing the cell efficiency. To bridge the gap between the high efficiency technology and low cost manufacturing, a research and development tool and process was built and tested. This fully automated single vacuum PV manufacturing tool utilizes multiple inline close space sublimation (CSS) sources with automated substrate control. This maintains the proven scalability of the CSS technology and CSS source design but with the added versatility of independent substrate motion. This combination of a scalable deposition technology with increased cell fabrication flexibility has allowed for high efficiency cells to be manufactured and studied. The record efficiency of CdTe solar cells is lower than fundamental limitations due to a significant deficit in voltage. It has been modeled that there are two potential methods of decreasing this voltage deficiency. The first method is the incorporation of a high band gap film at the back contact to induce a conduction-band barrier that can reduce recombination by reflecting electrons from the back surface. The addition of a Cd1-x MgxTe (CMT) layer at the back of a CdTe solar cell should induce this desired offset and reflect both photoelectrons and forward-current electrons away from the rear surface. Higher collection of photoelectrons will increase the cells current and the reduction of forward current will increase the cells voltage. To have the optimal effect, CdTe must have reasonable carrier lifetimes and be fully depleted. To achieve this experimentally, CdTe layers have been grown sufficiently thin to help produce a fully depleted cell. A variety of measurements including performance curves, transmission electron microscopy, x

High-pressure single-crystal neutron diffraction (to 20 kbar) using a pulsed source: Preliminary investigation of Tl3PSe4

International Nuclear Information System (INIS)

Alkire, R.W.; Larson, A.C.; Vergamini, P.J.; Schirber, J.E.; Morosin, B.

1985-01-01

A new technique is described for performing high-pressure single-crystal neutron diffraction [up to 20 kbar (2GPa) at room temperature], using a BeCu pressure cell, an area detector and the Los Alamos National Laboratory pulsed neutron source. Success of this method depends on the increase in information available with a multi-wavelength pulse neutron source, a novel orientation of a cylindrically symmetric pressure cell with its axis coincident with the neutron beam and a specific crystal orientation within the pressure cell. Bragg scattering from the pressure cell is avoided and background for a given 2theta is constant. For a crystal of orthorhombic or higher symmetry oriented with the incident beam passing midway between the major lattice vectors, it will be possible to refine a complete three-dimensional structure with data collected from only one pressure loading. Preliminary investigations of Tl 3 PSe 4 lattice parameters (space group Pcmn) at 15(1)kbar yielded linear compressibilities (. 1000 in kbar -1 ) of Ksub(a) = 1.05(8), Ksub(b) = 1.50(10), Ksub(c) = 1.20(8). The anisotropic compressibility is explained by examination of the ambient-pressure room-temperature structure. (orig.)

Performance and Safety Tests on Samsung 18650 Li-ion Cells: Two Cell Designs

Science.gov (United States)

Deng, Yi; Jeevarajan, Judith; Rehm, Raymond; Bragg, Bobby; Zhang, Wenlin

2002-01-01

In order to meet the applications for space shuttle in future, two types of Samsung cells, with capacity 1800 mAh and 2000 mAh, have been investigated. The studies focused on: (1) Performance tests: completed 250 cycles at various combinations of charge/discharge C rates and discharge capacity measurements at various temperatures; and (2) Safety tests: overcharge and overdischarge, heat abuse, short circuit, internal and external short, and vibration, vacuum, and drop tests

Effect of Perovskite Film Preparation on Performance of Solar Cells

Directory of Open Access Journals (Sweden)

Yaxian Pei

2016-01-01

Full Text Available For the perovskite solar cells (PSCs, the performance of the PSCs has become the focus of the research by improving the crystallization and morphology of the perovskite absorption layer. In this thesis, based on the structure of mesoporous perovskite solar cells (MPSCs, we designed the experiments to improve the photovoltaic performance of the PSCs by improved processing technique, which mainly includes the following two aspects. Before spin-coating PbI2 solution, we control the substrate temperature to modify the crystal quality and morphology of perovskite films. On the other hand, before annealing, we keep PbI2 films for the different drying time at room temperature to optimize films morphology. In our trials, it was found that the substrate temperature is more important in determining the photovoltaic performance than drying time. These results indicate that the crystallization and morphology of perovskite films affect the absorption intensity and obviously influence the short circuit current density of MPSCs. Utilizing films prepared by mentioning two methods, MPSCs with maximum power conversion efficiency of over 4% were fabricated for the active area of 0.5 × 0.5 cm2.

Performance enhancement technique of visible light communications using passive photovoltaic cell

Science.gov (United States)

Wu, Jhao-Ting; Chow, Chi-Wai; Liu, Yang; Hsu, Chin-Wei; Yeh, Chien-Hung

2017-06-01

The light emitting diode (LED) based visible light communication (VLC) system can provide lighting and communication simultaneously. It has attracted much attenuation recently. As the photovoltaic cell (also known as solar cell) is physically flexible, low cost, and easily available, it could be a good choice for the VLC receiver (Rx). Furthermore, besides acting as the VLC Rx, the solar cell can convert VLC signal into electricity for charging up the Rx devices. Hence, it could be a promising candidate for the future internet-of-thing (IoT) networks. However, using solar cell as VLC Rx is challenging, since the response of the solar cell is highly limited and it will limit the VLC data rate. In this work, we propose and demonstrate for the first time using pre-distortion Manchester coding (MC) signal to enhance the signal performance of solar cell Rx based VLC. The proposed scheme can significantly mitigate the slow response, as well as the direct-current (DC) wandering effect of the solar cell; hence 50 times increase in data rate can be experimentally achieved.

28 CFR 2.48 - Revocation: Preliminary interview.

Science.gov (United States)

2010-07-01

... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Revocation: Preliminary interview. 2.48....48 Revocation: Preliminary interview. (a) Interviewing officer. A parolee who is retaken on a warrant issued by a Commissioner shall be given a preliminary interview by an official designated by the Regional...

Clinical responses in patients with advanced colorectal cancer to a dendritic cell based vaccine

DEFF Research Database (Denmark)

Burgdorf, Stefan K; Fischer, Anders; Myschetzky, Peter S

2008-01-01

Patients with disseminated colorectal cancer have a poor prognosis. Preliminary studies have shown encouraging results from vaccines based on dendritic cells. The aim of this phase II study was to evaluate the effect of treating patients with advanced colorectal cancer with a cancer vaccine based...... with this DC-based cancer vaccine was safe and non-toxic. Stable disease was found in 24% (4/17) of the patients. The quality of life remained for most categories high and stable throughout the study period.......Patients with disseminated colorectal cancer have a poor prognosis. Preliminary studies have shown encouraging results from vaccines based on dendritic cells. The aim of this phase II study was to evaluate the effect of treating patients with advanced colorectal cancer with a cancer vaccine based......-testis antigens. Vaccines were biweekly administered intradermally with a total of 10 vaccines per patient. CT scans were performed and responses were graded according to the RECIST criteria. Quality of life was monitored with the SF-36 questionnaire. Toxicity and adverse events were graded according...

TESTING AND PERFORMANCE ANALYSIS OF NASA 5 CM BY 5 CM BI-SUPPORTED SOLID OXIDE ELECTROLYSIS CELLS OPERATED IN BOTH FUEL CELL AND STEAM ELECTROLYSIS MODES

Energy Technology Data Exchange (ETDEWEB)

R. C. O' Brien; J. E. O' Brien; C. M. Stoots; X. Zhang; S. C. Farmer; T. L. Cable; J. A. Setlock

2011-11-01

A series of 5 cm by 5 cm bi-supported Solid Oxide Electrolysis Cells (SOEC) were produced by NASA for the Idaho National Laboratory (INL) and tested under the INL High Temperature Steam Electrolysis program. The results from the experimental demonstration of cell operation for both hydrogen production and operation as fuel cells is presented. An overview of the cell technology, test apparatus and performance analysis is also provided. The INL High Temperature Steam Electrolysis laboratory has developed significant test infrastructure in support of single cell and stack performance analyses. An overview of the single cell test apparatus is presented. The test data presented in this paper is representative of a first batch of NASA's prototypic 5 cm by 5 cm SOEC single cells. Clearly a significant relationship between the operational current density and cell degradation rate is evident. While the performance of these cells was lower than anticipated, in-house testing at NASA Glenn has yielded significantly higher performance and lower degradation rates with subsequent production batches of cells. Current post-test microstructure analyses of the cells tested at INL will be published in a future paper. Modification to cell compositions and cell reduction techniques will be altered in the next series of cells to be delivered to INL with the aim to decrease the cell degradation rate while allowing for higher operational current densities to be sustained. Results from the testing of new batches of single cells will be presented in a future paper.

Analysis of performance losses of direct ethanol fuel cells with the aid of a reference electrode

Science.gov (United States)

Li, Guangchun; Pickup, Peter G.

The performances of direct ethanol fuel cells with different anode catalysts, different ethanol concentrations, and at different operating temperatures have been studied. The performance losses of the cell have been separated into individual electrode performance losses with the aid of a reference electrode, ethanol crossover has been quantified, and CO 2 and acetic acid production have been measured by titration. It has been shown that the cell performance strongly depends on the anode catalyst, ethanol concentration, and operating temperature. It was found that the cathode and anode exhibit different dependences on ethanol concentration and operating temperature. The performance of the cathode is very sensitive to the rate of ethanol crossover. Product analysis provides insights into the mechanisms of electro-oxidation of ethanol.

Analysis of performance losses of direct ethanol fuel cells with the aid of a reference electrode

Energy Technology Data Exchange (ETDEWEB)

Li, Guangchun; Pickup, Peter G. [Department of Chemistry, Memorial University of Newfoundland, Elizabeth Avenue, St. John' s, Newfoundland (Canada A 1B 3X7)

2006-10-20

The performances of direct ethanol fuel cells with different anode catalysts, different ethanol concentrations, and at different operating temperatures have been studied. The performance losses of the cell have been separated into individual electrode performance losses with the aid of a reference electrode, ethanol crossover has been quantified, and CO{sub 2} and acetic acid production have been measured by titration. It has been shown that the cell performance strongly depends on the anode catalyst, ethanol concentration, and operating temperature. It was found that the cathode and anode exhibit different dependences on ethanol concentration and operating temperature. The performance of the cathode is very sensitive to the rate of ethanol crossover. Product analysis provides insights into the mechanisms of electro-oxidation of ethanol. (author)

Business cycles and the financial performance of fuel cell companies

International Nuclear Information System (INIS)

Henriques, I.; Sadorsky, P.

2005-01-01

Fuel cells are expected to play a major role in a hydrogen powered world. They will provide power to homes, modes of transportation and appliances. Hydrogen is the most abundant element in nature, but it must be extracted in order to be usable. It can be produced from oil, natural gas and coal or from renewable sources such as biomass, thermal or nuclear reactions. Fuel cells running on hydrogen extracted from non renewable resources have an efficiency of 30 per cent, which is twice as efficient as an internal combustion engine. The greatest barrier to mass commercialization is the cost of making hydrogen-powered auto engines. Also, an infrastructure must be developed to refill hydrogen cars. One solution is to build a hydrogen highway using the existing natural gas grid to produce hydrogen and sell it at existing filling stations. The cost of building 12,000 refueling pumps in urban areas which will provide access to 70 per cent of America's population is estimated at $10 to $15 billion. This paper described the vector autoregression (VAR) model which empirically examines the relationship between financial performance of fuel cell companies and business cycles. It was used to measure how sensitive the financial performance of fuel cell companies are to changes in macroeconomic activity. A four variable VAR model was developed to examine the relationship between stock prices, oil prices and interest rates. It was shown that the stock prices of fuel cell companies are affected by shocks to technology stock prices and oil prices, with the former having a longer lasting impact. These results add to the growing literature that oil price movements are not as important as once thought. 15 refs., 3 tabs., 3 figs