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Sample records for supralabyrinthine air cell

  1. Surgical anatomy of the anterior supralabyrinthine air cell tract.

    Science.gov (United States)

    Gluth, M B; Cohen, M A; Friedland, P L; Atlas, M D

    2011-10-01

    In order to safely explore the medial wall of the attic, a working knowledge of the anatomy of the anterior supralabyrinthine air cell tract is required. To clarify the surgically relevant anatomical relationships that comprise the anterior supralabyrinthine air cell tract. Surgical dissection of 10 fresh cadaveric temporal bones was undertaken, including measurement of distances between the key anterior supralabyrinthine anatomical landmarks. The following mean distances were calculated: the labyrinthine segment between the geniculate ganglion and the ampullated end of the superior semicircular canal, 2.33 mm (range 1.75-2.75); the tympanic segment between the anterior margin of the oval window niche and the geniculate ganglion, 3.58 mm (range 3.25-4); and from the tympanic segment adjacent to the anterior margin of the oval window niche to the labyrinthine segment adjacent to the superior semicircular canal, 3.48 mm (range 3-4.25). The key anatomical landmarks of the anterior supralabyrinthine air cell tract define a distinct triangular segment of bone, knowledge of which is helpful in surgical dissection.

  2. Aire and T cell development.

    Science.gov (United States)

    Anderson, Mark S; Su, Maureen A

    2011-04-01

    In the thymus, developing T cells that react against self-antigens with high affinity are deleted in the process of negative selection. An essential component of this process is the display of self-antigens, including those whose expression are usually restricted to specific tissues, to developing T cells within the thymus. The Autoimmune Regulator (Aire) gene plays a crucial role in the expression of tissue specific self-antigens within the thymus, and disruption of Aire function results in spontaneous autoimmunity in both humans and mice. Recent advances have been made in our understanding of how Aire influences the expression of thousands of tissue-specific antigens in the thymus. Additional roles of Aire, including roles in chemokine and cytokine expression, have also been revealed. Factors important in the differentiation of Aire-expressing medullary thymic epithelial cells have been defined. Finally, the identity of antigen presenting cells in negative selection, including the role of medullary thymic epithelial cells in displaying tissue specific antigens to T cells, has also been clarified. Copyright © 2010 Elsevier Ltd. All rights reserved.

  3. Fuel Cell Electrodes for Hydrogen-Air Fuel Cell Assemblies.

    Science.gov (United States)

    The report describes the design and evaluation of a hydrogen-air fuel cell module for use in a portable hydrid fuel cell -battery system. The fuel ... cell module consists of a stack of 20 single assemblies. Each assembly contains 2 electrically independent cells with a common electrolyte compartment

  4. Air breathing lithium power cells

    Science.gov (United States)

    Farmer, Joseph C.

    2014-07-15

    A cell suitable for use in a battery according to one embodiment includes a catalytic oxygen cathode; a stabilized zirconia electrolyte for selective oxygen anion transport; a molten salt electrolyte; and a lithium-based anode. A cell suitable for use in a battery according to another embodiment includes a catalytic oxygen cathode; an electrolyte; a membrane selective to molecular oxygen; and a lithium-based anode.

  5. High performance zinc air fuel cell stack

    Science.gov (United States)

    Pei, Pucheng; Ma, Ze; Wang, Keliang; Wang, Xizhong; Song, Mancun; Xu, Huachi

    2014-03-01

    A zinc air fuel cell (ZAFC) stack with inexpensive manganese dioxide (MnO2) as the catalyst is designed, in which the circulation flowing potassium hydroxide (KOH) electrolyte carries the reaction product away and acts as a coolant. Experiments are carried out to investigate the characteristics of polarization, constant current discharge and dynamic response, as well as the factors affecting the performance and uniformity of individual cells in the stack. The results reveal that the peak power density can be as high as 435 mW cm-2 according to the area of the air cathode sheet, and the influence factors on cell performance and uniformity are cell locations, filled state of zinc pellets, contact resistance, flow rates of electrolyte and air. It is also shown that the time needed for voltages to reach steady state and that for current step-up or current step-down are both in milliseconds, indicating the ZAFC can be excellently applied to vehicles with rapid dynamic response demands.

  6. AIRE deficiency leads to impaired iNKT cell development.

    Science.gov (United States)

    Lindh, Emma; Rosmaraki, Eleftheria; Berg, Louise; Brauner, Hanna; Karlsson, Mikael C I; Peltonen, Leena; Höglund, Petter; Winqvist, Ola

    2010-02-01

    Autoimmune Polyendocrine Syndrome type I (APS I) is caused by mutations in the Autoimmune Regulator gene (AIRE), and results in the immunological destruction of endocrine organs. Herein we have characterized the CD1d-restricted invariant NKT cells (iNKT) and NK cells in APS I patients and Aire(-/-) mice, two cell populations known to play a role in the regulation of autoimmune disease. We show that the frequency of circulating iNKT cells is reduced in APS I patients compared to healthy controls. In accordance with this, iNKT cells are significantly reduced in the thymus and peripheral organs of Aire(-/-) mice. Bone marrow transfer from wild type donors into lethally irradiated Aire(-/-) recipients led to a decreased iNKT cell population in the liver, suggesting an impaired development of iNKT cells in the absence of Aire expression in radio-resistant cells. In contrast to the iNKT cells, both conventional NK cells and thymus-derived NK cells were unaffected by Aire deficiency and differentiated normally in Aire(-/-) mice. Our results show that expression of Aire in radio-resistant cells is important for the development of iNKT cells, whereas NK cell development and function does not depend on Aire. Copyright 2009 Elsevier Ltd. All rights reserved.

  7. Pressurized solid oxide fuel cell integral air accumular containment

    Science.gov (United States)

    Gillett, James E.; Zafred, Paolo R.; Basel, Richard A.

    2004-02-10

    A fuel cell generator apparatus contains at least one fuel cell subassembly module in a module housing, where the housing is surrounded by a pressure vessel such that there is an air accumulator space, where the apparatus is associated with an air compressor of a turbine/generator/air compressor system, where pressurized air from the compressor passes into the space and occupies the space and then flows to the fuel cells in the subassembly module, where the air accumulation space provides an accumulator to control any unreacted fuel gas that might flow from the module.

  8. Progress of air-breathing cathode in microbial fuel cells

    Science.gov (United States)

    Wang, Zejie; Mahadevan, Gurumurthy Dummi; Wu, Yicheng; Zhao, Feng

    2017-07-01

    Microbial fuel cell (MFC) is an emerging technology to produce green energy and vanquish the effects of environmental contaminants. Cathodic reactions are vital for high electrical power density generated from MFCs. Recently tremendous attentions were paid towards developing high performance air-breathing cathodes. A typical air-breathing cathode comprises of electrode substrate, catalyst layer, and air-diffusion layer. Prior researches demonstrated that each component influenced the performance of air-breathing cathode MFCs. This review summarized the progress in development of the individual component and elaborated main factors to the performance of air-breathing cathode.

  9. Aire knockdown in medullary thymic epithelial cells affects Aire protein, deregulates cell adhesion genes and decreases thymocyte interaction.

    Science.gov (United States)

    Pezzi, Nicole; Assis, Amanda Freire; Cotrim-Sousa, Larissa Cotrim; Lopes, Gabriel Sarti; Mosella, Maritza Salas; Lima, Djalma Sousa; Bombonato-Prado, Karina F; Passos, Geraldo Aleixo

    2016-09-01

    We demonstrate that even a partial reduction of Aire mRNA levels by siRNA-induced Aire knockdown (Aire KD) has important consequences to medullary thymic epithelial cells (mTECs). Aire knockdown is sufficient to reduce Aire protein levels, impair its nuclear location, and cause an imbalance in large-scale gene expression, including genes that encode cell adhesion molecules. These genes drew our attention because adhesion molecules are implicated in the process of mTEC-thymocyte adhesion, which is critical for T cell development and the establishment of central self-tolerance. Accordingly, we consider the following: 1) mTECs contribute to the elimination of self-reactive thymocytes through adhesion; 2) Adhesion molecules play a crucial role during physical contact between these cells; and 3) Aire is an important transcriptional regulator in mTECs. However, its role in controlling mTEC-thymocyte adhesion remains unclear. Because Aire controls adhesion molecule genes, we hypothesized that the disruption of its expression could influence mTEC-thymocyte interaction. To test this hypothesis, we used a murine Aire(+) mTEC cell line as a model system to reproduce mTEC-thymocyte adhesion in vitro. Transcriptome analysis of the mTEC cell line revealed that Aire KD led to the down-modulation of more than 800 genes, including those encoding for proteins involved in cell adhesion, i.e., the extracellular matrix constituent Lama1, the CAM family adhesion molecules Vcam1 and Icam4, and those that encode peripheral tissue antigens. Thymocytes co-cultured with Aire KD mTECs had a significantly reduced capacity to adhere to these cells. This finding is the first direct evidence that Aire also plays a role in controlling mTEC-thymocyte adhesion. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Polymer electrolyte fuel cells: flow field for efficient air operation

    Energy Technology Data Exchange (ETDEWEB)

    Buechi, F.N.; Tsukada, A.; Haas, O.; Scherer, G.G. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    A new flow field was designed for a polymer electrolyte fuel cell stack with an active area of 200 cm{sup 2} for operation at low air stoichiometry and low air over pressure. Optimum of gas flow and channel dimensions were calculated based on the required pressure drop in the fluid. Single cells and a bi-cell stack with the new flow field show an improved current/voltage characteristic when operated at low air stoichiometries as compared to that of the previous non optimized design. (author) 4 figs., 3 refs.

  11. Fabrication of VB2/air cells for electrochemical testing.

    Science.gov (United States)

    Stuart, Jessica; Lopez, Ruben; Lau, Jason; Li, Xuguang; Waje, Mahesh; Mullings, Matthew; Rhodes, Christopher; Licht, Stuart

    2013-08-05

    A technique to investigate the properties and performance of new multi-electron metal/air battery systems is proposed and presented. A method for synthesizing nanoscopic VB2 is presented as well as step-by-step procedure for applying a zirconium oxide coating to the VB2 particles for stabilization upon discharge. The process for disassembling existing zinc/air cells is shown, in addition construction of the new working electrode to replace the conventional zinc/air cell anode with a the nanoscopic VB2 anode. Finally, discharge of the completed VB2/air battery is reported. We show that using the zinc/air cell as a test bed is useful to provide a consistent configuration to study the performance of the high-energy high capacity nanoscopic VB2 anode.

  12. Air Breathing Direct Methanol Fuel Cell

    Science.gov (United States)

    Ren; Xiaoming

    2003-07-22

    A method for activating a membrane electrode assembly for a direct methanol fuel cell is disclosed. The method comprises operating the fuel cell with humidified hydrogen as the fuel followed by running the fuel cell with methanol as the fuel.

  13. Annular feed air breathing fuel cell stack

    Science.gov (United States)

    Wilson, Mahlon S.

    1996-01-01

    A stack of polymer electrolyte fuel cells is formed from a plurality of unit cells where each unit cell includes fuel cell components defining a periphery and distributed along a common axis, where the fuel cell components include a polymer electrolyte membrane, an anode and a cathode contacting opposite sides of the membrane, and fuel and oxygen flow fields contacting the anode and the cathode, respectively, wherein the components define an annular region therethrough along the axis. A fuel distribution manifold within the annular region is connected to deliver fuel to the fuel flow field in each of the unit cells. In a particular embodiment, a single bolt through the annular region clamps the unit cells together. In another embodiment, separator plates between individual unit cells have an extended radial dimension to function as cooling fins for maintaining the operating temperature of the fuel cell stack.

  14. Spontaneous T cell mediated keratoconjunctivitis in Aire-deficient mice

    Science.gov (United States)

    Yeh, S; de Paiva, C S; Hwang, C S; Trinca, K; Lingappan, A; Rafati, J K; Farley, W J; Li, D-Q; Pflugfelder, S C

    2013-01-01

    Background/aims Patients with autoimmune polyendocrinopathy-candiasis-ectodermal dystrophy (APECED) develop severe keratoconjunctivitis, corneal scarring and visual loss, but the precise pathogenesis is unknown. This study evaluated the ocular surface immune cell environment, conjunctival goblet cell density and response to desiccating environmental stress of the autoimmune regulatory (Aire) gene knockout murine model of APECED. Methods Aire-deficient and wild type (WT) mice were subjected to desiccating stress from a drafty, low-humidity environment and pharmacological inhibition of tear secretion for 5 days. Immune cell populations (CD4+, CD8+, CD11b+, CD45+) and goblet cell density were measured in ocular surface tissues and meibomian glands, and compared with baseline values. Results Greater CD4+ T cell populations were observed in the conjunctival epithelium of Aire-deficient mice (pAPECED. PMID:19429577

  15. DIRECT AMMONIA-AIR FUEL CELL.

    Science.gov (United States)

    A new type of direct oxidation ammonia fuel cell was investigated. This cell is based on the use of a non-aqueous fused hydroxide electrolyte matrix...EMF’s of 0.5 to 0.6 volts. At practical levels of current density the direct ammonia fuel cell has an overall efficiency of about 60% compared to 30-35% for the indirect-type fuel cell . (Author)

  16. Continuous measurement of radon concentration in air with Lucas cell

    International Nuclear Information System (INIS)

    Machaj, B.; Urbanski, P.

    1998-01-01

    Lucas cell was investigated as alpha radiation detector for continuous measurement of radon concentration in air with air sampling by means of the pump. The investigations carried out indicate that short lived radon decay products inside of the Lucas chamber with dimensions φ54x74 mm (0.17L) attach to the internal walls of the cell and are not removed when the cell is flushed with fresh air. This effect and the known effect of increase of radon daughters concentration when pure radon is introduced into the cell results in delay of response of the gage to variations of radon concentration. The response of the gage is considered and signal processing is suggested that can be useful in continuous measurement of radon concentration. (author)

  17. Annular feed air breathing fuel cell stack

    Science.gov (United States)

    Wilson, Mahlon S.; Neutzler, Jay K.

    1997-01-01

    A stack of polymer electrolyte fuel cells is formed from a plurality of unit cells where each unit cell includes fuel cell components defining a periphery and distributed along a common axis, where the fuel cell components include a polymer electrolyte membrane, an anode and a cathode contacting opposite sides of the membrane, and fuel and oxygen flow fields contacting the anode and the cathode, respectively, wherein the components define an annular region therethrough along the axis. A fuel distribution manifold within the annular region is connected to deliver fuel to the fuel flow field in each of the unit cells. The fuel distribution manifold is formed from a hydrophilic-like material to redistribute water produced by fuel and oxygen reacting at the cathode. In a particular embodiment, a single bolt through the annular region clamps the unit cells together. In another embodiment, separator plates between individual unit cells have an extended radial dimension to function as cooling fins for maintaining the operating temperature of the fuel cell stack.

  18. A methanol/air fuel cell system

    Science.gov (United States)

    Asher, W. J.

    1974-01-01

    High power-density, self-regulating fuel cell develops electrical power from catalyzed reaction between methanol and atmospheric oxygen. Cells such as these are of particular interest, because they may one day offer an emission-free, extremely efficient alternative to internal-combustion engines as power source.

  19. A regenerative zinc-air fuel cell

    Science.gov (United States)

    Smedley, Stuart I.; Zhang, X. Gregory

    The zinc regenerative fuel cell (ZRFC) developed by the former Metallic Power Inc. over the period from 1998 to 2004 is described. The component technologies and engineering solutions for various technical issues are discussed in relation to their functionality in the system. The system was designed to serve as a source of backup emergency power for remote or difficult to access cell phone towers during periods when the main power was interrupted. It contained a 12 cell stack providing 1.8 kW, a separate fuel tank containing zinc pellet fuel and electrolyte, and a zinc electrolyzer to regenerate the zinc pellets during standby periods. Offsite commissioning and testing of the system was successfully performed. The intellectual property of the ZRFC technology is now owned by Teck Cominco Metals Ltd.

  20. Aluminum-air power cell research and development

    Science.gov (United States)

    Cooper, J. F.

    1984-12-01

    The wedge-shaped design, of the aluminum-air battery being developed, is mechanically simple and capable of full anode utilization and rapid full or partial recharge. To maintain constant interelectrode separation and to collect anodic current, the cell uses tin-coated copper tracks mounted on removable cassettes. Under gravity feed, slabs of aluminum enter the cell at a continuous and constant rate and gradually assume the wedge shape as they dissolve. Voltage losses at this tin-aluminum junction are 7 mV at 2 kA/m(2). A second-generation wedge cell incorporates air and electrolyte manifolding into individually replaceable air-cathode cassettes. Prototype wedge cells of one design were operated simultaneously with a fluidized-bed crystallizer, which stabilized aluminate concentration and produced a granular aluminum-trihydroxide reaction product. Electrolyte was circulated between the cell and crystallizer, and a hydrocyclone was used to retain particles larger than 0.015 mm within the crystallizer. Air electrodes were tested over simulated vehicle drive systems that include a standby phase in cold, supersaturated electrolyte.

  1. The California fuel cell partnership: an avenue to clean air

    Science.gov (United States)

    Lloyd, Alan C.

    The California Fuel Cell Partnership presently consists of eight private companies, two state agencies and a federal government representative that will attempt to demonstrate the feasibility of fuel cell cars and buses. California has attempted to advance the commercialization of zero-emission vehicles for much of the past decade to help the state reduce its high levels of air pollution. A special advisory panel convened by the California Air Resources Board concluded last year that fuel cell technology could meet the key requirements for automobiles. The successful commercialization of fuel cell vehicles would help to reduce the levels of ozone, fine particles and toxic air contaminants that pose health risks to California's population. This technology can also help to reduce carbon dioxide emissions. California regulations now encourage the development of zero and near-zero emission vehicle technologies, including fuel cells. The Fuel Cell Partnership will operate approximately 50 fuel cell cars and buses until the year 2003 in order to produce important information on the vehicles and fueling infrastructure needed to support them.

  2. A novel conditional Aire allele enables cell-specific ablation of the immune tolerance regulator Aire

    Czech Academy of Sciences Publication Activity Database

    Dobeš, Jan; Edenhofer, F.; Vobořil, Matouš; Brabec, Tomáš; Dobešová, Martina; Čepková, Adéla; Klein, L.; Rajewsky, K.; Filipp, Dominik

    2017-01-01

    Roč. 48, č. 3 (2017), s. 546-548 ISSN 0014-2980 Institutional support: RVO:68378050 Keywords : Aire * Conditional Knockout * Immune tolerance * Medullary thymic epithelial cells Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.227, year: 2016

  3. Detonation cell widths in hydrogen-air-diluent mixtures

    International Nuclear Information System (INIS)

    Stamps, D.W.

    1990-01-01

    In this paper I report on the influence of steam and carbon dioxide on the detonability of hydrogen-air mixtures. Data were obtained on the detonation cell width in a heated detonation tube that is 0.43 m in diameter and 13.1 m long. The detonation cell widths were correlated using a characteristic length calculated from a chemical kinetic model. The addition of either diluent to a hydrogen-air mixture increased the cell width for all equivalence ratios. For equal diluent concentrations, however, carbon dioxide not only yielded larger increases in the cell width than steam, but its efficacy relative to steam was predicted to increase with increasing concentration. The range of detonable hydrogen concentrations in a hydrogen-air mixture initially at 1 atm pressure was found to be between 11.6 percent and 74.9 percent for mixtures at 20 degree C and 9.4 percent and 76.9 percent for mixtures at 100 degree C. The detonation limit was between 38.8 percent and 40.5 percent steam for a stoichiometric hydrogen-air-steam mixture initially at 100 degree C and 1 atm. 10 refs., 4 figs., 1 tab

  4. Cytotoxic effects of air freshener biocides in lung epithelial cells.

    Science.gov (United States)

    Kwon, Jung-Taek; Lee, Mimi; Seo, Gun-Baek; Kim, Hyun-Mi; Shim, Ilseob; Lee, Doo-Hee; Kim, Taksoo; Seo, Jung Kwan; Kim, Pilje; Choi, Kyunghee

    2013-09-01

    This study evaluated the cytotoxicity of mixtures of citral (CTR) and either benzisothiazolinone (BIT, Mix-CTR-BIT) or triclosan (TCS, Mix-CTR-TCS) in human A549 lung epithelial cells. We investigated the effects of various mix ratios of these common air freshener ingredients on cell viability, cell proliferation, reactive oxygen species (ROS) generation, and DNA damage. Mix-CTR-BIT and Mix-CTR-TCS significantly decreased the viability of lung epithelial cells and inhibited cell growth in a dose-dependent manner. In addition, both mixtures increased ROS generation, compared to that observed in control cells. In particular, cell viability, growth, and morphology were affected upon increase in the proportion of BIT or TCS in the mixture. However, comet analysis showed that treatment of cells with Mix-CTR-BIT or Mix-CTR-TCS did not increase DNA damage. Taken together, these data suggested that increasing the content of biocides in air fresheners might induce cytotoxicity, and that screening these compounds using lung epithelial cells may contribute to hazard assessment.

  5. Air

    Science.gov (United States)

    ... gov/ Home The environment and your health Air Air While we don’t often think about the ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be ...

  6. Differential Features of AIRE-Induced and AIRE-Independent Promiscuous Gene Expression in Thymic Epithelial Cells.

    Science.gov (United States)

    St-Pierre, Charles; Trofimov, Assya; Brochu, Sylvie; Lemieux, Sébastien; Perreault, Claude

    2015-07-15

    Establishment of self-tolerance in the thymus depends on promiscuous expression of tissue-restricted Ags (TRA) by thymic epithelial cells (TEC). This promiscuous gene expression (pGE) is regulated in part by the autoimmune regulator (AIRE). To evaluate the commonalities and discrepancies between AIRE-dependent and -independent pGE, we analyzed the transcriptome of the three main TEC subsets in wild-type and Aire knockout mice. We found that the impact of AIRE-dependent pGE is not limited to generation of TRA. AIRE decreases, via non-cell autonomous mechanisms, the expression of genes coding for positive regulators of cell proliferation, and it thereby reduces the number of cortical TEC. In mature medullary TEC, AIRE-driven pGE upregulates non-TRA coding genes that enhance cell-cell interactions (e.g., claudins, integrins, and selectins) and are probably of prime relevance to tolerance induction. We also found that AIRE-dependent and -independent TRA present several distinctive features. In particular, relative to AIRE-induced TRA, AIRE-independent TRA are more numerous and show greater splicing complexity. Furthermore, we report that AIRE-dependent versus -independent TRA project nonredundant representations of peripheral tissues in the thymus. Copyright © 2015 by The American Association of Immunologists, Inc.

  7. Air pollution and children's health: sickle cell disease

    Directory of Open Access Journals (Sweden)

    Silvia Maria de Macedo Barbosa

    2015-02-01

    Full Text Available The hallmarks of sickle cell disease are anemia and vasculopathy. The aim of this study was to assess the association between air pollution and children's emergency room visits of sickle cell patients. We adopted a case-crossover design. Daily counts of children's and adolescents' sickle cell disease emergency room visits from the pediatric emergency unit in São Paulo, Brazil, were evaluated from September 1999 to December 2004, matching by temperature, humidity and controlling for day of the week. Interquartile range increases of the four-day moving averages of PM10, NO2, SO2, CO, and O3 were associated with increases of 18.9% (95%CI: 11.2-26.5, 19% (95%CI: 8.3-29.6, 14.4% (95%CI: 6.5-22.4, 16,5% (95%CI: 8.9-24.0, and 9.8% (95%CI: 1.1-18.6 in total sickle cell emergency room visits, respectively. When the analyses were stratified by pain, PM10 was found to be 40.3% higher than in sickle cell patients without pain symptoms. Exposure to air pollution can affect the cardiovascular health of children and may promote a significant health burden in a sensitive group.

  8. Interference-robust Air Interface for 5G Small Cells

    DEFF Research Database (Denmark)

    Tavares, Fernando Menezes Leitão

    Generation (5G) RAT standard is expected to support data rates greater than 10 Gbps with very low latency, very low energy consumption and provide the required scalability that will allow the network to transport a 1000 to 10000 times more mobile data traffic in 2020 than a similar network would do in 2010....... To meet these challenging network capacity expansion requirements, the design of the new 5G RAT standard will make use of three main strategies: more antennas, more spectrum and more cells. All these strategies will have important roles in the new system, but the deployment of a massive number of small...... to the fundamental role of inter-cell interference in this type of networks, the inter-cell interference problem must be addressed since the beginning of the design of the new standard. This Ph.D. thesis deals with the design of an interference-robust air interface for 5G small cell networks. The interference...

  9. An improved bifunctional oxygen (air) electrode for reversible alkaline fuel cell systems and for rechargeable metal-air batteries

    Science.gov (United States)

    Kordesch, K.; Steininger, K.-H.; Tomantschger, K.

    1988-10-01

    Electrodes with a nickel layer of dual pore structure on the electrolyte side and a PTFE-bonded carbon layer on the oxygen (air) side are discussed, with application to space energy storage. During the electrolyis stage, the oxygen fills the large pores of the porous Ni structure with gas. During the discharge cycle, the iron/air or zinc/air cell of the carbon layer operates as a regular oxygen electrode.

  10. Age-Associated Decline in Thymic B Cell Expression of Aire and Aire-Dependent Self-Antigens

    Directory of Open Access Journals (Sweden)

    Sergio Cepeda

    2018-01-01

    Full Text Available Although autoimmune disorders are a significant source of morbidity and mortality in older individuals, the mechanisms governing age-associated increases in susceptibility remain incompletely understood. Central T cell tolerance is mediated through presentation of self-antigens by cells constituting the thymic microenvironment, including epithelial cells, dendritic cells, and B cells. Medullary thymic epithelial cells (mTECs and B cells express distinct cohorts of self-antigens, including tissue-restricted self-antigens (TRAs, such that developing T cells are tolerized to antigens from peripheral tissues. We find that expression of the TRA transcriptional regulator Aire, as well as Aire-dependent genes, declines with age in thymic B cells in mice and humans and that cell-intrinsic and cell-extrinsic mechanisms contribute to the diminished capacity of peripheral B cells to express Aire within the thymus. Our findings indicate that aging may diminish the ability of thymic B cells to tolerize T cells, revealing a potential mechanistic link between aging and autoimmunity.

  11. ADAM17 deletion in thymic epithelial cells alters aire expression without affecting T cell developmental progression.

    Directory of Open Access Journals (Sweden)

    David M Gravano

    2010-10-01

    Full Text Available Cellular interactions between thymocytes and thymic stromal cells are critical for normal T cell development. Thymic epithelial cells (TECs are important stromal niche cells that provide essential growth factors, cytokines, and present self-antigens to developing thymocytes. The identification of genes that mediate cellular crosstalk in the thymus is ongoing. One candidate gene, Adam17, encodes a metalloprotease that functions by cleaving the ectodomain of several transmembrane proteins and regulates various developmental processes. In conventional Adam17 knockout mice, a non-cell autonomous role for ADAM17 in adult T cell development was reported, which strongly suggested that expression of ADAM17 in TECs was required for normal T cell development. However, knockdown of Adam17 results in multisystem developmental defects and perinatal lethality, which has made study of the role of Adam17 in specific cell types difficult. Here, we examined T cell and thymic epithelial cell development using a conditional knockout approach.We generated an Adam17 conditional knockout mouse in which floxed Adam17 is deleted specifically in TECs by Cre recombinase under the control of the Foxn1 promoter. Normal T cell lineage choice and development through the canonical αβ T cell stages was observed. Interestingly, Adam17 deficiency in TECs resulted in reduced expression of the transcription factor Aire. However, no alterations in the patterns of TEC phenotypic marker expression and thymus morphology were noted.In contrast to expectation, our data clearly shows that absence of Adam17 in TECs is dispensable for normal T cell development. Differentiation of TECs is also unaffected by loss of Adam17 based on phenotypic markers. Surprisingly, we have uncovered a novel genetic link between Adam17and Aire expression in vivo. The cell type in which ADAM17 mediates its non-cell autonomous impact and the mechanisms by which it regulates intrathymic T cell development

  12. Mechanically refuelable zinc/air electric vehicle cells

    Science.gov (United States)

    Noring, J.; Gordon, S.; Maimoni, A.; Spragge, M.; Cooper, J. F.

    1992-12-01

    Refuelable zinc/air batteries have long been considered for motive as well as stationary power because of a combination of high specific energy, low initial cost, and the possibility of mechanical recharge by electrolyte exchange and additions of metallic zinc. In this context, advanced slurry batteries, stationary packed bed cells, and batteries offering replaceable cassettes have been reported recently. The authors are developing self-feeding, particulate-zinc/air batteries for electric vehicle applications. Emissionless vehicle legislation in California motivated efforts to consider a new approach to providing an electric vehicle with long range (400 km), rapid refueling (10 minutes) and highway safe acceleration - factors which define the essential functions of common automobiles. Such an electric vehicle would not compete with emerging secondary battery vehicles in specialized applications (commuting vehicles, delivery trucks). Rather, different markets would be sought where long range or rapid range extension are important. Examples are: taxis, continuous-duty fork-lift trucks and shuttle busses, and general purpose automobiles having modest acceleration capabilities. In the long range, a mature fleet would best use regional plants to efficiently recover zinc from battery reaction products. One option would be to use chemical/thermal reduction to recover the zinc. The work described focuses on development of battery configurations which efficiently and completely consume zinc particles, without clogging or changing discharge characteristics.

  13. Application of AirCell Cellular AMPS Network and Iridium Satellite System Dual Mode Service to Air Traffic Management

    Science.gov (United States)

    Shamma, Mohammed A.

    2004-01-01

    The AirCell/Iridium dual mode service is evaluated for potential applications to Air Traffic Management (ATM) communication needs. The AirCell system which is largely based on the Advanced Mobile Phone System (AMPS) technology, and the Iridium FDMA/TDMA system largely based on the Global System for Mobile Communications(GSM) technology, can both provide communication relief for existing or future aeronautical communication links. Both have a potential to serve as experimental platforms for future technologies via a cost effective approach. The two systems are well established in the entire CONUS and globally hence making it feasible to utilize in all regions, for all altitudes, and all classes of aircraft. Both systems have been certified for air usage. The paper summarizes the specifications of the AirCell/Iridium system, as well as the ATM current and future links, and application specifications. the paper highlights the scenarios, applications, and conditions under which the AirCell/Iridium technology can be suited for ATM Communication.

  14. AIRE is not essential for the induction of human tolerogenic dendritic cells.

    Science.gov (United States)

    Crossland, Katherine L; Abinun, Mario; Arkwright, Peter D; Cheetham, Timothy D; Pearce, Simon H; Hilkens, Catharien M U; Lilic, Desa

    2016-06-01

    Loss-of-function mutations of the Autoimmune Regulator (AIRE) gene results in organ-specific autoimmunity and disease Autoimmune Polyendocrinopathy type 1 (APS1)/Autoimmune Polyendocrinopathy Candidiasis Ectodermal Dystrophy (APECED). The AIRE protein is crucial in the induction of central tolerance, promoting ectopic expression of tissue-specific antigens in medullary thymic epithelial cells and enabling removal of self-reactive T-cells. AIRE expression has recently been detected in myeloid dendritic cells (DC), suggesting AIRE may have a significant role in peripheral tolerance. DC stimulation of T-cells is critical in determining the initiation or lack of an immune response, depending on the pattern of costimulation and cytokine production by DCs, defining immunogenic/inflammatory (inflDC) and tolerogenic (tolDC) DC. In AIRE-deficient patients and healthy controls, we validated the role of AIRE in the generation and function of monocyte-derived inflDC and tolDCs by determining mRNA and protein expression of AIRE and comparing activation markers (HLA-DR/DP/DQ,CD83,CD86,CD274(PDL-1),TLR-2), cytokine production (IL-12p70,IL-10,IL-6,TNF-α,IFN-γ) and T-cell stimulatory capacity (mixed lymphocyte reaction) of AIRE+ and AIRE- DCs. We show for the first time that: (1) tolDCs from healthy individuals express AIRE; (2) AIRE expression is not significantly higher in tolDC compared to inflDC; (3) tolDC can be generated from APECED patient monocytes and (4) tolDCs lacking AIRE retain the same phenotype and reduced T-cell stimulatory function. Our findings suggest that AIRE does not have a role in the induction and function of monocyte-derived tolerogenic DC in humans, but these findings do not exclude a role for AIRE in peripheral tolerance mediated by other cell types.

  15. Lineage Tracing and Cell Ablation Identify a Post-Aire-Expressing Thymic Epithelial Cell Population

    Directory of Open Access Journals (Sweden)

    Todd C. Metzger

    2013-10-01

    Full Text Available Thymic epithelial cells in the medulla (mTECs play a critical role in enforcing central tolerance through expression and presentation of tissue-specific antigens (TSAs and deletion of autoreactive thymocytes. TSA expression requires autoimmune regulator (Aire, a transcriptional activator present in a subset of mTECs characterized by high CD80 and major histocompatibility complex II expression and a lack of potential for differentiation or proliferation. Here, using an Aire-DTR transgenic line, we show that short-term ablation specifically targets Aire+ mTECs, which quickly undergo RANK-dependent recovery. Repeated ablation also affects Aire− mTECs, and using an inducible Aire-Cre fate-mapping system, we find that this results from the loss of a subset of mTECs that showed prior expression of Aire, maintains intermediate TSA expression, and preferentially migrates toward the center of the medulla. These results clearly identify a distinct stage of mTEC development and underscore the diversity of mTECs that play a key role in maintaining tolerance.

  16. Changes in the air cell volume of artificially incubated ostrich eggs ...

    African Journals Online (AJOL)

    A total of 2160 images of candled, incubated ostrich eggs were digitized to determine the percentage of egg volume occupied by the air cell at different stages of incubation. The air cell on average occupied 2.5% of the volume of fresh eggs. For eggs that hatched successfully, this volume increased to an average of 24.4% ...

  17. 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.

  18. Diversity of TCRs on natural Foxp3+ T cells in mice lacking Aire expression.

    Science.gov (United States)

    Daniely, Danielle; Kern, Joanna; Cebula, Anna; Ignatowicz, Leszek

    2010-06-15

    Medullary thymic epithelial cells expressing the Aire gene play a critical role in the induction of tolerance to tissue-specific Ags (TSAs). It was postulated that recognition of Aire-controlled TSAs by immature thymocytes results in the selection of natural CD4+Foxp3+ regulatory T cells (Tregs) and enriches this repertoire in self-reactive receptors, contributing to its vast diversity. In this study, we compared the TCRs on individual Tregs in Aire+ and Aire- mice expressing a miniature TCR repertoire (TCRmini) along with GFP driven by the Foxp3 promoter (Foxp3GFP). The Treg TCR repertoires in Aire+ and Aire- TCRminiFoxp3GFP mice were similar and more diverse than their repertoires on CD4+ Foxp3- thymocytes. Further, TCRs found on potentially self-reactive T cells, with an activated phenotype (CD4+Foxp3-CD62Llow) in Aire- TCRminiFoxp3GFP mice, appear distinct from TCRs found on Tregs in Aire+ TCRminiFoxp3GFP mice. Lastly, we found no evidence that TSAs presented by medullary thymic epithelial cells in Aire+TCRmini mice are often recognized as agonists by Treg-derived TCR hybridomas or CD4+CD25+ thymocytes, containing both natural Tregs and precursors. Thus, positive selection and self-reactivity of the global Treg repertoire are not controlled by Aire-dependent TSAs.

  19. Air humidity and water pressure effects on the performance of air-cathode microbial fuel cell cathodes

    KAUST Repository

    Ahn, Yongtae

    2014-02-01

    To better understand how air cathode performance is affected by air humidification, microbial fuel cells were operated under different humidity conditions or water pressure conditions. Maximum power density decreased from 1130 ± 30 mW m-2 with dry air to 980 ± 80 mW m -2 with water-saturated air. When the cathode was exposed to higher water pressures by placing the cathode in a horizontal position, with the cathode oriented so it was on the reactor bottom, power was reduced for both with dry (1030 ± 130 mW m-2) and water-saturated (390 ± 190 mW m-2) air. Decreased performance was partly due to water flooding of the catalyst, which would hinder oxygen diffusion to the catalyst. However, drying used cathodes did not improve performance in electrochemical tests. Soaking the cathode in a weak acid solution, but not deionized water, mostly restored performance (960 ± 60 mW m-2), suggesting that there was salt precipitation in the cathode that was enhanced by higher relative humidity or water pressure. These results showed that cathode performance could be adversely affected by both flooding and the subsequent salt precipitation, and therefore control of air humidity and water pressure may need to be considered for long-term MFC operation. © 2013 Elsevier B.V. All rights reserved.

  20. Combinatorial electrochemical cell array for high throughput screening of micro-fuel-cells and metal/air batteries

    Science.gov (United States)

    Jiang, Rongzhong

    2007-07-01

    An electrochemical cell array was designed that contains a common air electrode and 16 microanodes for high throughput screening of both fuel cells (based on polymer electrolyte membrane) and metal/air batteries (based on liquid electrolyte). Electrode materials can easily be coated on the anodes of the electrochemical cell array and screened by switching a graphite probe from one cell to the others. The electrochemical cell array was used to study direct methanol fuel cells (DMFCs), including high throughput screening of electrode catalysts and determination of optimum operating conditions. For screening of DMFCs, there is about 6% relative standard deviation (percentage of standard deviation versus mean value) for discharge current from 10to20mA/cm2. The electrochemical cell array was also used to study tin/air batteries. The effect of Cu content in the anode electrode on the discharge performance of the tin/air battery was investigated. The relative standard deviations for screening of metal/air battery (based on zinc/air) are 2.4%, 3.6%, and 5.1% for discharge current at 50, 100, and 150mA/cm2, respectively.

  1. Stem Cells: All that Is Solid Melts into Air

    NARCIS (Netherlands)

    van der Heijden, Maartje; Vermeulen, Louis

    2017-01-01

    The intestinal epithelium displays great resilience, as several cell populations can replenish the stem cell pool upon damage. Two studies in Cell Stem Cell extend this capacity to enteroendocrine cells, addressing the molecular basis underlying cellular plasticity observed in the intestine and the

  2. 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,…

  3. Aire unleashes stalled RNA polymerase to induce ectopic gene expression in thymic epithelial cells.

    Science.gov (United States)

    Giraud, Matthieu; Yoshida, Hideyuki; Abramson, Jakub; Rahl, Peter B; Young, Richard A; Mathis, Diane; Benoist, Christophe

    2012-01-10

    Aire is a transcriptional regulator that induces expression of peripheral tissue antigens (PTA) in thymic medullary epithelial cells (MECs), driving immunological self-tolerance in differentiating T cells. To elucidate its mechanistic pathways, we examined its transcriptional impact in MECs in vivo by microarray analysis with mRNA-spanning probes. This analysis revealed initiation of Aire-activated genes to be comparable in Aire-deficient and wild-type MECs, but with a block to elongation after 50-100 bp in the absence of Aire, suggesting activation by release of stalled polymerases by Aire. In contrast, patterns of activation by transcription factors such as Klf4 were consistent with regulation of initiation. Mapping of Aire and RNA polymerase-II (Pol-II) by ChIP and high-throughput sequencing (ChIP-seq) revealed that Aire bound all Pol-II-rich transcriptional start sites (TSS), irrespective of its eventual effect. However, the genes it preferentially activated were characterized by a relative surfeit of stalled polymerases at the TSS, which resolved once Aire was introduced into cells. Thus, transcript mapping and ChIP-seq data indicate that Aire activates ectopic transcription not through specific recognition of PTA gene promoters but by releasing stalled polymerases.

  4. Air

    CERN Document Server

    Rivera, Andrea

    2017-01-01

    Air is all around us. Learn how it is used in art, technology, and engineering. Five easy-to-read chapters explain the science behind air, as well as its real-world applications. Vibrant, full-color photos, bolded glossary words, and a key stats section let readers zoom in even deeper. Aligned to Common Core Standards and correlated to state standards. Abdo Zoom is a division of ABDO.

  5. Aire Expression Is Inherent to Most Medullary Thymic Epithelial Cells during Their Differentiation Program.

    Science.gov (United States)

    Kawano, Hiroshi; Nishijima, Hitoshi; Morimoto, Junko; Hirota, Fumiko; Morita, Ryoko; Mouri, Yasuhiro; Nishioka, Yasuhiko; Matsumoto, Mitsuru

    2015-12-01

    Aire in medullary thymic epithelial cells (mTECs) plays an important role in the establishment of self-tolerance. Because Aire(+) mTECs appear to be a limited subset, they may constitute a unique lineage(s) among mTECs. An alternative possibility is that all mTECs are committed to express Aire in principle, but Aire expression by individual mTECs is conditional. To investigate this issue, we established a novel Aire reporter strain in which endogenous Aire is replaced by the human AIRE-GFP-Flag tag (Aire/hAGF-knockin) fusion gene. The hAGF reporter protein was produced and retained very efficiently within mTECs as authentic Aire nuclear dot protein. Remarkably, snapshot analysis revealed that mTECs expressing hAGF accounted for >95% of mature mTECs, suggesting that Aire expression does not represent a particular mTEC lineage(s). We confirmed this by generating Aire/diphtheria toxin receptor-knockin mice in which long-term ablation of Aire(+) mTECs by diphtheria toxin treatment resulted in the loss of most mature mTECs beyond the proportion of those apparently expressing Aire. These results suggest that Aire expression is inherent to all mTECs but may occur at particular stage(s) and/or cellular states during their differentiation, thus accounting for the broad impact of Aire on the promiscuous gene expression of mTECs. Copyright © 2015 by The American Association of Immunologists, Inc.

  6. Post-Aire maturation of thymic medullary epithelial cells involves selective expression of keratinocyte-specific autoantigens

    OpenAIRE

    Xiaoping eWang; Martti eLaan; Rudolf eBichele; Kai eKisand; Hamish S Scott; Hamish S Scott; Pärt ePeterson

    2012-01-01

    The autoimmune regulator (Aire)-directed ectopic expression of tissue-specific antigens (TSAs) by mature medullary thymic epithelial cells (mTECs) has been viewed as an essential mechanism in the induction of central tolerance. Recent data suggest that the survival of mTECs extends beyond the Aire+ cell population to form the post-Aire mTEC population and Hassall's corpuscles (HCs). The nature and function of these post-Aire epithelial cells and structures, however, have remained unidentified...

  7. NKT cell development in the absence of the autoimmune regulator gene (Aire).

    Science.gov (United States)

    Pitt, Lauren A; Hubert, Francois-Xavier; Scott, Hamish S; Godfrey, Dale I; Berzins, Stuart P

    2008-10-01

    Autoimmune regulator gene (Aire)-deficient mice develop an array of autoimmune lesions that reflect failures of immune tolerance. Negative selection is clearly compromised in these mice, but there is evidence to suggest that other mechanisms of tolerance might also be affected, including a possible impairment of regulatory T cell (Treg) development. Studies to date have failed to demonstrate any significant impact on the development or function of the FOXP3+ Treg compartment, but NKT cells represent a distinct regulatory cell lineage that also develop in the thymus and which are known to influence self-tolerance. Aire-related defects coincide with NKT cell deficiencies in a number of animal models, but the direct consequence of Aire-deficiency on NKT cell development has not been established. In this study, we demonstrate that the frequency, distribution and cytokine production of NKT cells and their subsets is principally normal in Aire-deficient mice. We conclude that Aire has little or no effect on regulatory T cell development in general and NKT cells in particular.

  8. Air

    International Nuclear Information System (INIS)

    Gugele, B.; Scheider, J.; Spangl, W.

    2001-01-01

    In recent years several regulations and standards for air quality and limits for air pollution were issued or are in preparation by the European Union, which have severe influence on the environmental monitoring and legislation in Austria. This chapter of the environmental control report of Austria gives an overview about the legal situation of air pollution control in the European Union and in specific the legal situation in Austria. It gives a comprehensive inventory of air pollution measurements for the whole area of Austria of total suspended particulates, ozone, volatile organic compounds, nitrogen oxides, sulfur dioxide, carbon monoxide, heavy metals, benzene, dioxin, polycyclic aromatic hydrocarbons and eutrophication. For each of these pollutants the measured emission values throughout Austria are given in tables and geographical charts, the environmental impact is discussed, statistical data and time series of the emission sources are given and legal regulations and measures for an effective environmental pollution control are discussed. In particular the impact of fossil-fuel power plants on the air pollution is analyzed. (a.n.)

  9. Detonation cell size measurements and predictions in hydrogen-air-steam mixtures at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Ciccarelli, G.; Ginsberg, T.; Boccio, J.; Economos, C.

    1994-01-01

    The present research reports on the effect of initial mixture temperature on the experimentally measured detonation cell size for hydrogen-air-steam mixtures. Experimental and theoretical research related to combustion phenomena in hydrogen-air-steam mixtures has been ongoing for many years. However, detonation cell size data currently exists or hydrogen-air-steam mixtures up to a temperature of only 400K. Sever accident scenarios have been identified for light water reactors (LWRs) where hydrogen-air mixture temperatures in excess of 400K could be generated within containment. The experiments in this report focus on extending the cell size data base for initial mixture temperatures in excess of 400K. The experiments were carried out in a 10-cm inner-diameter, 6.1-m long heated detonation tube with a maximum operating temperature of 700K and spatial temperature uniformity of {plus_minus}14K. Detonation cell size measurements provide clear evidence that the effect of hydrogen-air initial gas mixture temperature, in the range 300K--650K, is to decrease cell size and, hence, to increase the sensitivity of the mixture to undergo detonations. The effect of steam content, at any given temperature, is to increase the cell size and, thereby, to decrease the sensitivity of stoichiometric hydrogen-air mixtures. The hydrogen-air detonability limits for the 10-cm inside-diameter test vessel, based upon the onset of single-head spin, decreased from 15 percent by hydrogen at 300K down to about 9 percent hydrogen at 650K. The one-dimensional ZND model does a very good job at predicting the overall trends in the cell size data over the range of hydrogen-air-steam mixture compositions and temperature studied in the experiments.

  10. Detonation cell size measurements and predictions in hydrogen-air-steam mixtures at elevated temperatures

    International Nuclear Information System (INIS)

    Ciccarelli, G.; Ginsberg, T.; Boccio, J.; Economos, C.

    1994-01-01

    The present research reports on the effect of initial mixture temperature on the experimentally measured detonation cell size for hydrogen-air-steam mixtures. Experimental and theoretical research related to combustion phenomena in hydrogen-air-steam mixtures has been ongoing for many years. However, detonation cell size data currently exists or hydrogen-air-steam mixtures up to a temperature of only 400K. Sever accident scenarios have been identified for light water reactors (LWRs) where hydrogen-air mixture temperatures in excess of 400K could be generated within containment. The experiments in this report focus on extending the cell size data base for initial mixture temperatures in excess of 400K. The experiments were carried out in a 10-cm inner-diameter, 6.1-m long heated detonation tube with a maximum operating temperature of 700K and spatial temperature uniformity of ±14K. Detonation cell size measurements provide clear evidence that the effect of hydrogen-air initial gas mixture temperature, in the range 300K--650K, is to decrease cell size and, hence, to increase the sensitivity of the mixture to undergo detonations. The effect of steam content, at any given temperature, is to increase the cell size and, thereby, to decrease the sensitivity of stoichiometric hydrogen-air mixtures. The hydrogen-air detonability limits for the 10-cm inside-diameter test vessel, based upon the onset of single-head spin, decreased from 15 percent by hydrogen at 300K down to about 9 percent hydrogen at 650K. The one-dimensional ZND model does a very good job at predicting the overall trends in the cell size data over the range of hydrogen-air-steam mixture compositions and temperature studied in the experiments

  11. Detonation cell size measurements and predictions in hydrogen-air-steam mixtures at elevated temperatures

    International Nuclear Information System (INIS)

    Ciccarelli, G.; Ginsberg, T.; Boccio, J.; Economos, C.; Sato, K.; Kinoshita, M.

    1994-01-01

    The effect of initial mixture temperature on the experimentally measured detonation cell size for hydrogen-air-steam mixtures at 0.1 MPa has been investigated. Experiments were carried out in a 10-cm-inner-diameter, 6.1-m-long heated detonation tube with a maximum operating temperature of 700 K and spatial temperature uniformity of ± 14 K. Detonation cell size measurements provide clear evidence that the effect of hydrogen-air initial gas mixture temperature, in the range 300--650 K, is to decrease cell size and, hence, to increase the sensitivity of the mixture to undergo detonations. The effect of steam content, at ay given temperature, is to increase the cell size and, thereby, to decrease the sensitivity of stoichiometric hydrogen-air mixtures. The hydrogen-air detonability limits for the 10-cm-inside-diameter test vessel, based upon the onset of single-head spin, decreased from 15% hydrogen at 300 K down to about 9% hydrogen at 650 K. The experimental detonation cell size data were correlated suing a Zel'dovich-von Neumann-Doering (ZND) model for the detonation using detailed chemical-kinetic reaction mechanisms. The proportionality constants used to scale the reaction zone length calculations from the ZND model varied from 3o to 51 for the hydrogen-air cell size data at 650 and 300 K, respectively

  12. Detonation cell size measurements and predictions in hydrogen-air-steam mixtures at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Ciccarelli, G.; Ginsberg, T.; Boccio, J.; Economos, C.; Sato, K.; Kinoshita, M. (Brookhaven National Lab., Upton, NY (United States). Safety and Risk Evaluation Division)

    1994-11-01

    The effect of initial mixture temperature on the experimentally measured detonation cell size for hydrogen-air-steam mixtures at 0.1 MPa has been investigated. Experiments were carried out in a 10-cm-inner-diameter, 6.1-m-long heated detonation tube with a maximum operating temperature of 700 K and spatial temperature uniformity of [+-] 14 K. Detonation cell size measurements provide clear evidence that the effect of hydrogen-air initial gas mixture temperature, in the range 300--650 K, is to decrease cell size and, hence, to increase the sensitivity of the mixture to undergo detonations. The effect of steam content, at ay given temperature, is to increase the cell size and, thereby, to decrease the sensitivity of stoichiometric hydrogen-air mixtures. The hydrogen-air detonability limits for the 10-cm-inside-diameter test vessel, based upon the onset of single-head spin, decreased from 15% hydrogen at 300 K down to about 9% hydrogen at 650 K. The experimental detonation cell size data were correlated suing a Zel'dovich-von Neumann-Doering (ZND) model for the detonation using detailed chemical-kinetic reaction mechanisms. The proportionality constants used to scale the reaction zone length calculations from the ZND model varied from 3o to 51 for the hydrogen-air cell size data at 650 and 300 K, respectively.

  13. Metal-air cell comprising an electrolyte with a room temperature ionic liquid and hygroscopic additive

    Science.gov (United States)

    Friesen, Cody A.; Krishnan, Ramkumar; Tang, Toni; Wolfe, Derek

    2014-08-19

    An electrochemical cell comprising an electrolyte comprising water and a hydrophobic ionic liquid comprising positive ions and negative ions. The electrochemical cell also includes an air electrode configured to absorb and reduce oxygen. A hydrophilic or hygroscopic additive modulates the hydrophobicity of the ionic liquid to maintain a concentration of the water in the electrolyte is between 0.001 mol % and 25 mol %.

  14. Overcurrent Abuse of Primary Prismatic Zinc–Air Battery Cells Studying Air Supply Effects on Performance and Safety Shut-Down

    OpenAIRE

    Fredrik Larsson; Antti Rytinki; Istaq Ahmed; Ingvar Albinsson; Bengt-Erik Mellander

    2017-01-01

    Overcurrent abuse has been performed on commercial 48 Ah primary prismatic zinc (Zn)–Air battery cells with full air supply as well as with shut-off air supply. Compared to other battery technologies, e.g., lithium-ion batteries, metal–air batteries offer the possibility to physically stop the battery operation by stopping its air supply, thus offering an additional protection against severe battery damage in the case of, e.g., an accidental short circuit. This method may also reduce the elec...

  15. Pressurized air cathodes for enhanced stability and power generation by microbial fuel cells

    KAUST Repository

    He, Weihua

    2016-09-30

    Large differences between the water and air pressure in microbial fuel cells (MFCs) can deform and damage cathodes. To avoid deformation, the cathode air pressure was controlled to balance pressure differences between the air and water. Raising the air pressures from 0 to 10 kPa at a set cathode potential of −0.3 V (versus Ag/AgCl) enhanced cathode performance by 17%, but pressures ≥25 kPa decreased current and resulted in air leakage into the solution. Matching the air pressure with the water pressure avoided cathode deformation and improved performance. The maximum power density increased by 15%, from 1070 ± 20 to 1230 ± 70 mW m, with balanced air and water pressures of 10–25 kPa. Oxygen partial pressures ≥12.5 kPa in the cathode compartment maintained the oxygen reduction rate to be within 92 ± 1% of that in ambient air. The use of pressurized air flow through the cathode compartments can enable closer spacing of the cathodes compared to passive gas transfer systems, which could make the reactor design more compact. The energy cost of pressurizing the cathodes was estimated to be smaller than the increase in power that resulted from the use of pressurized cathodes.

  16. Planar solid oxide fuel cell with staged indirect-internal air and fuel preheating and reformation

    Science.gov (United States)

    Geisbrecht, Rodney A; Williams, Mark C

    2003-10-21

    A solid oxide fuel cell arrangement and method of use that provides internal preheating of both fuel and air in order to maintain the optimum operating temperature for the production of energy. The internal preheat passes are created by the addition of two plates, one on either side of the bipolar plate, such that these plates create additional passes through the fuel cell. This internal preheat fuel cell configuration and method reduce the requirements for external heat exchanger units and air compressors. Air or fuel may be added to the fuel cell as required to maintain the optimum operating temperature through a cathode control valve or an anode control valve, respectively. A control loop comprises a temperature sensing means within the preheat air and fuel passes, a means to compare the measured temperature to a set point temperature and a determination based on the comparison as to whether the control valves should allow additional air or fuel into the preheat or bypass manifolds of the fuel cell.

  17. Air stable organic-inorganic nanoparticles hybrid solar cells

    Science.gov (United States)

    Qian, Lei; Yang, Jihua; Xue, Jiangeng; Holloway, Paul H.

    2015-09-29

    A solar cell includes a low work function cathode, an active layer of an organic-inorganic nanoparticle composite, a ZnO nanoparticle layer situated between and physically contacting the cathode and active layers; and a transparent high work function anode that is a bilayer electrode. The inclusion of the ZnO nanoparticle layer results in a solar cell displaying a conversion efficiency increase and reduces the device degradation rate. Embodiments of the invention are directed to novel ZnO nanoparticles that are advantageous for use as the ZnO nanoparticle layers of the novel solar cells and a method to prepare the ZnO nanoparticles.

  18. New, Efficient, and Reliable Air Electrode Material for Proton-Conducting Reversible Solid Oxide Cells.

    Science.gov (United States)

    Huan, Daoming; Shi, Nai; Zhang, Lu; Tan, Wenzhou; Xie, Yun; Wang, Wanhua; Xia, Changrong; Peng, Ranran; Lu, Yalin

    2018-01-17

    Driven by the demand to minimize fluctuation in common renewable energies, reversible solid oxide cells (RSOCs) have drawn increasing attention for they can operate either as fuel cells to produce electricity or as electrolysis cells to store electricity. Unfortunately, development of proton-conducting RSOCs (P-RSOCs) faces a major challenge of poor reliability because of the high content of steam involved in air electrode reactions, which could seriously decay the lifetime of air electrode materials. In this work, a very stable and efficient air electrode, SrEu 2 Fe 1.8 Co 0.2 O 7-δ (SEFC) with layer structure, is designed and deployed in P-RSOCs. X-ray diffraction analysis and High-angle annular dark-filed scanning transmission electron microscopy images of SEFC reveal that Sr atoms occupy the center of perovskite slabs, whereas Eu atoms arrange orderly in the rock-salt layer. Such a special structure of SEFC largely depresses its Lewis basicity and therefore its reactivity with steam. Applying the SEFC air electrode, our button switches smoothly between both fuel cell and electrolysis cell (EC) modes with no obvious degradation over a 135 h long-term test under wet H 2 (∼3% H 2 O) and 10% H 2 O-air atmospheres. A record of over 230 h is achieved in the long-term stability test in the EC mode, doubling the longest test that had been previously reported. Besides good stability, SEFC demonstrates great catalytic activity toward air electrode reactions when compared with traditional La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ air electrodes. This research highlights the potential of stable and efficient P-RSOCs as an important part in a sustainable new energy power system.

  19. DNA damage and mitochondria dysfunction in cell apoptosis induced by nonthermal air plasma

    Science.gov (United States)

    Kim, G. J.; Kim, W.; Kim, K. T.; Lee, J. K.

    2010-01-01

    Nonthermal plasma is known to induce animal cell death but the mechanism is not yet clear. Here, cellular and biochemical regulation of cell apoptosis is demonstrated for plasma treated cells. Surface type nonthermal air plasma triggered apoptosis of B16F10 mouse melanoma cancer cells causing DNA damage and mitochondria dysfunction. Plasma treatment activated caspase-3, apoptosis executioner. The plasma treated cells also accumulated gamma-H2A.X, marker for DNA double strand breaks, and p53 tumor suppressor gene as a response to DNA damage. Interestingly, cytochrome C was released from mitochondria and its membrane potential was changed significantly.

  20. Air pollution damage to cell membranes in lichens. Pt. 3

    Energy Technology Data Exchange (ETDEWEB)

    Pearson, L.C.; Rodgers, G.A.

    1982-01-01

    Downwind from field furnaces burning sulfur at the rate of 300 g/hr, SO/sub 2/ levels varied from 0.52 ppm at 10 m to 0.23 at 40 m in an open area where fumes could readily disperse but were considerably higher in an area where air movement was chanelled along a swale. The conductivity of water in which pieces of lichens were immersed following exposure to fumes from the field burners increased slightly in liches collected upwind from the burners or over 100 meters downwind, but increased considerably in specimens collected 15-30 m downwind. Leakage of electrolytes, as measured by increase in conductivity of water in which lichen pieces were immersed, was significantly higher downwind from burners in an open area than from those in a densely forested area.

  1. Isolation of mouse respiratory epithelial cells and exposure to experimental cigarette smoke at air liquid interface.

    Science.gov (United States)

    Lam, Hilaire C; Choi, Augustine M K; Ryter, Stefan W

    2011-02-21

    Pulmonary epithelial cells can be isolated from the respiratory tract of mice and cultured at air-liquid interface (ALI) as a model of differentiated respiratory epithelium. A protocol is described for isolating and exposing these cells to mainstream cigarette smoke (CS), in order to study epithelial cell responses to CS exposure. The protocol consists of three parts: the isolation of airway epithelial cells from mouse trachea, the culturing of these cells at air-liquid interface (ALI) as fully differentiated epithelial cells, and the delivery of calibrated mainstream CS to these cells in culture. The ALI culture system allows the culture of respiratory epithelia under conditions that more closely resemble their physiological setting than ordinary liquid culture systems. The study of molecular and lung cellular responses to CS exposure is a critical component of understanding the impact of environmental air pollution on human health. Research findings in this area may ultimately contribute towards understanding the etiology of chronic obstructive pulmonary disease (COPD), and other tobacco-related diseases, which represent major global health problems.

  2. An Optimization and Comparative Study of Air-Coupled CMUT Cells With Circular and Annular Geometries.

    Science.gov (United States)

    Na, Shuai; Li, Zhenhao; Wong, Lawrence L P; Chen, Albert I-Hsiang; Macecek, Mirek; Yeow, John T W

    2017-11-01

    Air-coupled capacitive micromachined ultrasonic transducers (CMUTs) with annular cell geometry have recently been reported to have a promising transmit sensitivity. This paper reports three optimization schemes, which further improve the transmit sensitivity and also help achieve a reasonable comparison between the novel annular and conventional circular cells. Lumped element models of both cell types with laminate plate structures are presented. Based on these models, a design optimization flowchart was constructed to facilitate analytical optimization on the three schemes. Circular and annular CMUTs with a common 97-kHz natural resonance frequency were fabricated and characterized to verify the efficacy of the optimization principle. Using the optimization flowchart, annular and circular cells with frequencies ranging from 100 to 300 kHz were analytically optimized and then compared. The comparison results demonstrate that, given the same dc bias and ac excitation voltage, the output power density at the plate surface of the optimized annular cell is double that of the optimized circular cell. Additionally, when generating the same surface power density, an optimized annular cell requires either half the dc bias or half the ac excitation voltage of an optimized circular cell. This paper provides a practical optimization framework for CMUT cell design and demonstrates the superiority of annular cells for air-coupled applications.

  3. A COMPUTATIONAL FLUID DYNAMICS ANALYSIS OF AIR FLOW THROUGH A TELECOM BACK-UP UNIT POWERED BY AN AIR-COOLED PROTON EXCHANGE MEMBRANE FUEL CELL

    DEFF Research Database (Denmark)

    Gao, Xin; Berning, Torsten; Kær, Søren Knudsen

    2016-01-01

    . This product heat has to be effectively removed from the fuel cell, and while automotive fuel cells are usually liquid-cooled using a secondary coolant loop similar to the internal combustion engines, stationary fuel cell systems as they are used for telecom back-up applications often rely on excessive air fed......Proton exchange membrane fuel cells (PEMFC’s) are currently being commercialized for various applications ranging from automotive to stationary such as powering telecom back-up units. In PEMFC’s, oxygen from air is internally combined with hydrogen to form water and produce electricity and heat...

  4. A specific anti-Aire antibody reveals aire expression is restricted to medullary thymic epithelial cells and not expressed in periphery.

    Science.gov (United States)

    Hubert, François-Xavier; Kinkel, Sarah A; Webster, Kylie E; Cannon, Ping; Crewther, Pauline E; Proeitto, Anna I; Wu, Li; Heath, William R; Scott, Hamish S

    2008-03-15

    Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy is an autoimmune disorder caused by mutations in the autoimmune regulator gene AIRE. We examined the expression of Aire in different organs (thymus, spleen, and lymph nodes) in C57BL/6 mice, using a novel rat mAb, specific for murine Aire. Using flow cytometry, directly fluorochrome-labeled mAb revealed Aire expression in a rare thymic cellular subset that was CD45(-), expressed low levels of Ly51, and was high for MHC-II and EpCam. This subset also expressed a specific pattern of costimulatory molecules, including CD40, CD80, and PD-L1. Immunohistochemical analysis revealed that Aire(+) cells were specifically localized to the thymus or, more precisely, to the cortico-medulla junction and medulla, correlating with the site of negative selection. Although in agreement with previous studies, low levels of Aire mRNA was detected in all dendritic cell subtypes however lacZ staining, immunohistochemistry and flow cytometry failed to detect Aire protein. At a cellular level, Aire was expressed in perinuclear speckles within the nucleus. This report provides the first detailed analysis of Aire protein expression, highlighting the precise location at both the tissue and cellular level.

  5. Effect of acrolein, a hazardous air pollutant in smoke, on human middle ear epithelial cells.

    Science.gov (United States)

    Song, Jae-Jun; Lee, Jong Dae; Lee, Byung Don; Chae, Sung Won; Park, Moo Kyun

    2013-10-01

    Acrolein is a hazardous air pollutant. Tobacco smoke and indoor air pollution are the main causes of human exposure. Acrolein has been shown to cause cytotoxicity in the airways and induce inflammation and mucin production in pulmonary cells. We investigated whether acrolein caused cytotoxicity, induced inflammation or increased expression of mucin in immortalized human middle ear epithelial cell lines (HMEECs). Cytotoxicity following acrolein treatment was investigated using the MTT assay, flow cytometry, and Hoechst 33342 staining of HMEECs. We measured expression of inflammatory cytokines tumor necrosis factor (TNF)-α and cyclo-oxygenase (COX)-2 and the mucin gene MUC5AC using semi-quantitative real-time reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting. Exposure to >50 μg/mL acrolein caused a decrease in cell viability. Acrolein induced apoptosis and necrosis at 50 μg/mL. Acrolein at 5-50 μg/mL increased expression of TNF-α and COX-2, as shown by RT-PCR and Western blotting. Acrolein exposure at 5-50 μg/mL for 2-24h increased MUC5AC expression, as determined by RT-PCR. Acrolein decreased cell viability, induced an inflammatory response, and increased mucin gene expression in HMEECs. These findings support the hypothesis that acrolein, a hazardous air pollutant in tobacco smoke and ambient air, is a risk factor for otitis media. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  6. Targeting cancer cells with reactive oxygen and nitrogen species generated by atmospheric-pressure air plasma.

    Science.gov (United States)

    Ahn, Hak Jun; Kim, Kang Il; Hoan, Nguyen Ngoc; Kim, Churl Ho; Moon, Eunpyo; Choi, Kyeong Sook; Yang, Sang Sik; Lee, Jong-Soo

    2014-01-01

    The plasma jet has been proposed as a novel therapeutic method for cancer. Anticancer activity of plasma has been reported to involve mitochondrial dysfunction. However, what constituents generated by plasma is linked to this anticancer process and its mechanism of action remain unclear. Here, we report that the therapeutic effects of air plasma result from generation of reactive oxygen/nitrogen species (ROS/RNS) including H2O2, Ox, OH-, •O2, NOx, leading to depolarization of mitochondrial membrane potential and mitochondrial ROS accumulation. Simultaneously, ROS/RNS activate c-Jun NH2-terminal kinase (JNK) and p38 kinase. As a consequence, treatment with air plasma jets induces apoptotic death in human cervical cancer HeLa cells. Pretreatment of the cells with antioxidants, JNK and p38 inhibitors, or JNK and p38 siRNA abrogates the depolarization of mitochondrial membrane potential and impairs the air plasma-induced apoptotic cell death, suggesting that the ROS/RNS generated by plasma trigger signaling pathways involving JNK and p38 and promote mitochondrial perturbation, leading to apoptosis. Therefore, administration of air plasma may be a feasible strategy to eliminate cancer cells.

  7. Cell volume regulation in the perfused liver of a freshwater air ...

    Indian Academy of Sciences (India)

    Madhu

    Cell volume regulation in the perfused liver of a freshwater air-breathing catfish Clarias batrachus under aniso-osmotic conditions: Roles of inorganic ions and taurine. CARINA GOSWAMI and NIRMALENDU SAHA*. Biochemical Adaptation Laboratory, Department of Zoology, North-Eastern Hill University, Shillong 793 022, ...

  8. Interference-Robust Air Interface for 5G Ultra-dense Small Cells

    DEFF Research Database (Denmark)

    Tavares, Fernando Menezes Leitão; Berardinelli, Gilberto; Mahmood, Nurul Huda

    2016-01-01

    An ultra-dense deployment of small cells is foreseen as the solution to cope with the exponential increase of the data rate demand targeted by the 5th Generation (5G) radio access technology. In this article, we propose an interference-robust air interface built upon the usage of advanced receive...

  9. Schottky Quantum Dot Solar Cells Stable in Air under Solar Illumination

    KAUST Repository

    Tang, Jiang

    2010-01-07

    (Figure Presented) The air stability and power conversion efficiency of solution-processed PbS quantum dot solar cells is dramatically improved by the insertion of 0.8 nm LiF between the PbS nanoparticle film and the Al contact. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA.

  10. A mixed-pH dual-electrolyte microfluidic aluminum–air cell with high performance

    International Nuclear Information System (INIS)

    Chen, Binbin; Leung, Dennis Y.C.; Xuan, Jin; Wang, Huizhi

    2017-01-01

    Highlights: • A mix-pH dual-electrolyte Al–air cell is proposed. • Cells with dual-electrolyte exhibit higher performance. • Cell performance increases with increasing electrolyte concentration and flow rate. • Optimized channel thickness is 0.3 mm. • A restriction of reaction activation on the Al side is observed. - Abstract: Energy storage capacity has been a major limiting factor in pursuit of increasing functionality and mobility for portable devices. To increase capacity limits, novel battery designs with multi-electron redox couples and increased voltages have been listed as a priority research direction by the US Department of Energy. This study leverages the benefits of microfluidics technology to develop a novel mixed-pH media aluminum–air cell which incorporates the advantages of the trivalence of aluminum and mixed-pH thermodynamics. Experimentally, the new cell exhibited an open circuit potential of 2.2 V and a maximum power density of 176 mW cm −2 , which are respectively 37.5% and 104.6% higher than conventional single alkaline aluminum–air cell under similar conditions. With further optimization of channel thickness, a power density of 216 mW cm −2 was achieved in the present study.

  11. Expression of autoimmune regulator gene (AIRE) and T regulatory cells in human thymomas.

    Science.gov (United States)

    Scarpino, S; Di Napoli, A; Stoppacciaro, A; Antonelli, M; Pilozzi, E; Chiarle, R; Palestro, G; Marino, M; Facciolo, F; Rendina, E A; Webster, K E; Kinkel, S A; Scott, H S; Ruco, L

    2007-09-01

    Expression of the autoimmune regulator gene (AIRE) and the presence of CD25(+)/forkhead box p3 (FoxP3)(+) T regulatory (T(reg)) cells were investigated in histologically normal adult thymi and in thymomas using immunohistochemistry and quantitative real-time polymerase chain reaction (PCR). In the normal thymus staining for AIRE was detected in the nucleus of some epithelial-like cells located in the medulla; in thymomas AIRE-positive cells were extremely rare and could be detected only in the areas of medullary differentiation of two B1 type, organoid thymomas. RNA was extracted from 36 cases of thymoma and 21 non-neoplastic thymi obtained from 11 myasthenic (MG(+)) and 10 non-myasthenic (MG(-)) patients. It was found that AIRE is 8.5-fold more expressed in non-neoplastic thymi than in thymomas (P = 0.01), and that the amount of AIRE transcripts present in the thymoma tissue are not influenced by the association with MG, nor by the histological type. A possible involvement of AIRE in the development of MG was suggested by the observation that medullary thymic epithelial cells isolated from AIRE-deficient mice contain low levels of RNA transcripts for CHRNA 1, a gene coding for acetylcholine receptor. Expression of human CHRNA 1 RNA was investigated in 34 human thymomas obtained from 20 MG(-) patients and 14 MG(+) patients. No significant difference was found in the two groups (thymoma MG(+), CHRNA1 = 0.013 +/- 0.03; thymoma MG-, CHRNA1 = 0.01 +/- 0.03). In normal and hyperplastic thymi CD25(+)/Foxp3(+) cells were located mainly in the medulla, and their number was not influenced by the presence of MG. Foxp3(+) and CD25(+) cells were significantly less numerous in thymomas. A quantitative estimate of T(reg) cells revealed that the levels of Foxp3 RNA detected in non-neoplastic thymi were significantly higher (P = 0.02) than those observed in 31 cases of thymomas. Our findings indicate that the tissue microenvironment of thymomas is defective in the expression of

  12. COD removal characteristics in air-cathode microbial fuel cells

    KAUST Repository

    Zhang, Xiaoyuan

    2015-01-01

    © 2014 Elsevier Ltd. Exoelectrogenic microorganisms in microbial fuel cells (MFCs) compete with other microorganisms for substrate. In order to understand how this affects removal rates, current generation, and coulombic efficiencies (CEs), substrate removal rates were compared in MFCs fed a single, readily biodegradable compound (acetate) or domestic wastewater (WW). Removal rates based on initial test conditions fit first-order kinetics, but rate constants varied with circuit resistance. With filtered WW (100Ω), the rate constant was 0.18h- 1, which was higher than acetate or filtered WW with an open circuit (0.10h- 1), but CEs were much lower (15-24%) than acetate. With raw WW (100Ω), COD removal proceeded in two stages: a fast removal stage with high current production, followed by a slower removal with little current. While using MFCs increased COD removal rate due to current generation, secondary processes will be needed to reduce COD to levels suitable for discharge.

  13. Defect internalization and tyrosine kinase activation in Aire deficient antigen presenting cells exposed to Candida albicans antigens.

    Science.gov (United States)

    Brännström, Johan; Hässler, Signe; Peltonen, Leena; Herrmann, Björn; Winqvist, Ola

    2006-12-01

    Patients with Autoimmune polyendocrine syndrome type I (APS I) present with multiple endocrine failures due to organ-specific autoimmune disease, thought to be T-cell-mediated. Paradoxically, APS I patients suffer from chronic mucocutaneous candidiasis. The mutated gene has been identified as the Autoimmune regulator (AIRE). Aire is expressed in medullary epithelial cells of the thymus and in antigen presenting cells in the periphery. T cells from Aire deficient mice and men displayed an enhanced proliferative response against Candida antigen in vitro, suggesting that Aire deficient T cells are competent in recognizing Candida albicans. In contrast, monocytes from APS I patients displayed a decreased and delayed internalization of zymosan. Furthermore, Candida antigen activated monocytes from APS I patients show decreased and altered phoshotyrosine kinase activation. In conclusion, Aire deficient APCs have a defect receptor mediated internalization of Candida which affects kinase activation, likely altering the innate Candida immune response.

  14. Overcurrent Abuse of Primary Prismatic Zinc–Air Battery Cells Studying Air Supply Effects on Performance and Safety Shut-Down

    Directory of Open Access Journals (Sweden)

    Fredrik Larsson

    2017-01-01

    Full Text Available Overcurrent abuse has been performed on commercial 48 Ah primary prismatic zinc (Zn–Air battery cells with full air supply as well as with shut-off air supply. Compared to other battery technologies, e.g., lithium-ion batteries, metal–air batteries offer the possibility to physically stop the battery operation by stopping its air supply, thus offering an additional protection against severe battery damage in the case of, e.g., an accidental short circuit. This method may also reduce the electrical hazard in a larger battery system since, by stopping the air supply, the voltage can be brought to zero while maintaining the energy capacity of the battery. Measurements of overdischarge currents and current cut-off by suffocation have been performed to assess the safety of this type of Zn–air battery. The time to get to zero battery voltage is shown to mainly be determined by the volume of air trapped in the cell.

  15. Harvesting Hydrogen Gas from Air Pollutants with an Unbiased Gas Phase Photoelectrochemical Cell.

    Science.gov (United States)

    Verbruggen, Sammy W; Van Hal, Myrthe; Bosserez, Tom; Rongé, Jan; Hauchecorne, Birger; Martens, Johan A; Lenaerts, Silvia

    2017-04-10

    The concept of an all-gas-phase photoelectrochemical (PEC) cell producing hydrogen gas from volatile organic contaminated gas and light is presented. Without applying any external bias, organic contaminants are degraded and hydrogen gas is produced in separate electrode compartments. The system works most efficiently with organic pollutants in inert carrier gas. In the presence of oxygen, the cell performs less efficiently but still significant photocurrents are generated, showing the cell can be run on organic contaminated air. The purpose of this study is to demonstrate new application opportunities of PEC technology and to encourage further advancement toward PEC remediation of air pollution with the attractive feature of simultaneous energy recovery and pollution abatement. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Characterizing Air Pollution Exposure Misclassification Errors Using Detailed Cell Phone Location Data

    Science.gov (United States)

    Yu, H.; Russell, A. G.; Mulholland, J. A.

    2017-12-01

    In air pollution epidemiologic studies with spatially resolved air pollution data, exposures are often estimated using the home locations of individual subjects. Due primarily to lack of data or logistic difficulties, the spatiotemporal mobility of subjects are mostly neglected, which are expected to result in exposure misclassification errors. In this study, we applied detailed cell phone location data to characterize potential exposure misclassification errors associated with home-based exposure estimation of air pollution. The cell phone data sample consists of 9,886 unique simcard IDs collected on one mid-week day in October, 2013 from Shenzhen, China. The Community Multi-scale Air Quality model was used to simulate hourly ambient concentrations of six chosen pollutants at 3 km spatial resolution, which were then fused with observational data to correct for potential modeling biases and errors. Air pollution exposure for each simcard ID was estimated by matching hourly pollutant concentrations with detailed location data for corresponding IDs. Finally, the results were compared with exposure estimates obtained using the home location method to assess potential exposure misclassification errors. Our results show that the home-based method is likely to have substantial exposure misclassification errors, over-estimating exposures for subjects with higher exposure levels and under-estimating exposures for those with lower exposure levels. This has the potential to lead to a bias-to-the-null in the health effect estimates. Our findings suggest that the use of cell phone data has the potential for improving the characterization of exposure and exposure misclassification in air pollution epidemiology studies.

  17. Building air conditioning system using fuel cell: Case study for Kuwait

    Energy Technology Data Exchange (ETDEWEB)

    Darwish, Mohamed A. [Department of Mechanical Engineering, Kuwait University, Street 2, Gada 4, Section 1, P.O. Box 5969, Safat 13060, NA Kuwait, Kuwait City (Kuwait)

    2007-12-15

    Air conditioning machines in Kuwait consume more than 75% of electric energy generated at peak load time. It is in the national interest of Kuwait to decelerate the continuous increase of peak electric power demand. One way to do this is to install for new complexes or high-rise apartments buildings distributed utilities (isolated small power plants), mainly for air conditioning A/C systems. Fuel cells are among the alternatives considered for distributed utilities. This paper discusses the use of commercially available phosphoric acid fuel cell PAFC, known as ONSI P25 to operate air conditioning systems for big buildings in Kuwait. The proposed fuel cell, which is usually delivered with built-in heat exchanger for hot water, is operated by natural gas and uses a propylene glycol-water loop to recover thermal energy. The PAFC has 200 kW nominal electric power capacity, and produces thermal energy of 105 kW thermal energy at 120 C, and 100 kW at 60 C. The performance characteristics for the proposed fuel cell are very well documented. In the present study, it is suggested that the fuel cell operates combined mechanical vapor compression and absorption water chillers to utilize the fuel cell full output of electric power and waste heat. Also, to meet the required A/C cooling capacity system by the limited fuel cell power output, it is proposed to use cold storage technique. This allows fuel cell power output to supply the needed energy for average as well as peak A/C system capacity. (author)

  18. Aire controls the differentiation program of thymic epithelial cells in the medulla for the establishment of self-tolerance

    Science.gov (United States)

    Yano, Masashi; Kuroda, Noriyuki; Han, Hongwei; Meguro-Horike, Makiko; Nishikawa, Yumiko; Kiyonari, Hiroshi; Maemura, Kentaro; Yanagawa, Yuchio; Obata, Kunihiko; Takahashi, Satoru; Ikawa, Tomokatsu; Satoh, Rumi; Kawamoto, Hiroshi; Mouri, Yasuhiro; Matsumoto, Mitsuru

    2008-01-01

    The roles of autoimmune regulator (Aire) in the expression of the diverse arrays of tissue-restricted antigen (TRA) genes from thymic epithelial cells in the medulla (medullary thymic epithelial cells [mTECs]) and in organization of the thymic microenvironment are enigmatic. We approached this issue by creating a mouse strain in which the coding sequence of green fluorescent protein (GFP) was inserted into the Aire locus in a manner allowing concomitant disruption of functional Aire protein expression. We found that Aire+ (i.e., GFP+) mTECs were the major cell types responsible for the expression of Aire-dependent TRA genes such as insulin 2 and salivary protein 1, whereas Aire-independent TRA genes such as C-reactive protein and glutamate decarboxylase 67 were expressed from both Aire+ and Aire− mTECs. Remarkably, absence of Aire from mTECs caused morphological changes together with altered distribution of mTECs committed to Aire expression. Furthermore, we found that the numbers of mTECs that express involucrin, a marker for terminal epidermal differentiation, were reduced in Aire-deficient mouse thymus, which was associated with nearly an absence of Hassall's corpuscle-like structures in the medulla. Our results suggest that Aire controls the differentiation program of mTECs, thereby organizing the global mTEC integrity that enables TRA expression from terminally differentiated mTECs in the thymic microenvironment. PMID:19015306

  19. Removable air-cathode to overcome cathode biofouling in microbial fuel cells.

    Science.gov (United States)

    Oliot, Manon; Etcheverry, Luc; Bergel, Alain

    2016-12-01

    An innovative microbial fuel cell (MFC) design is described, which allows the air-cathode to be replaced easily without draining the electrolyte. MFCs equipped with 9-cm 2 or 50-cm 2 bioanodes provided 0.6 and 0.7W/m 2 (referred to the cathode surface area) and were boosted to 1.25 and 1.96W/m 2 , respectively, when the initial air-cathode was replaced by a new one. These results validate the practical interest of removable air-cathodes and evidence the importance of the cathode biofouling that takes place during the MFC starting phase. As this biofouling is compensated by the concomitant improvement of the bioanodes it cannot be detected on the power curves and may be a widespread cause of performance underestimation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Interferometrically stable, enclosed, spinning sample cell for spectroscopic experiments on air-sensitive samples.

    Science.gov (United States)

    Baranov, Dmitry; Hill, Robert J; Ryu, Jisu; Park, Samuel D; Huerta-Viga, Adriana; Carollo, Alexa R; Jonas, David M

    2017-01-01

    In experiments with high photon flux, it is necessary to rapidly remove the sample from the beam and to delay re-excitation until the sample has returned to equilibrium. Rapid and complete sample exchange has been a challenge for air-sensitive samples and for vibration-sensitive experiments. Here, a compact spinning sample cell for air and moisture sensitive liquid and thin film samples is described. The principal parts of the cell are a copper gasket sealed enclosure, a 2.5 in. hard disk drive motor, and a reusable, chemically inert glass sandwich cell. The enclosure provides an oxygen and water free environment at the 1 ppm level, as demonstrated by multi-day tests with sodium benzophenone ketyl radical. Inside the enclosure, the glass sandwich cell spins at ≈70 Hz to generate tangential speeds of 7-12 m/s that enable complete sample exchange at 100 kHz repetition rates. The spinning cell is acoustically silent and compatible with a ±1 nm rms displacement stability interferometer. In order to enable the use of the spinning cell, we discuss centrifugation and how to prevent it, introduce the cycle-averaged resampling rate to characterize repetitive excitation, and develop a figure of merit for a long-lived photoproduct buildup.

  1. A Rechargeable Li-Air Fuel Cell Battery Based on Garnet Solid Electrolytes

    Science.gov (United States)

    Sun, Jiyang; Zhao, Ning; Li, Yiqiu; Guo, Xiangxin; Feng, Xuefei; Liu, Xiaosong; Liu, Zhi; Cui, Guanglei; Zheng, Hao; Gu, Lin; Li, Hong

    2017-01-01

    Non-aqueous Li-air batteries have been intensively studied in the past few years for their theoretically super-high energy density. However, they cannot operate properly in real air because they contain highly unstable and volatile electrolytes. Here, we report the fabrication of solid-state Li-air batteries using garnet (i.e., Li6.4La3Zr1.4Ta0.6O12, LLZTO) ceramic disks with high density and ionic conductivity as the electrolytes and composite cathodes consisting of garnet powder, Li salts (LiTFSI) and active carbon. These batteries run in real air based on the formation and decomposition at least partially of Li2CO3. Batteries with LiTFSI mixed with polyimide (PI:LiTFSI) as a binder show rechargeability at 200 °C with a specific capacity of 2184 mAh g−1carbon at 20 μA cm−2. Replacement of PI:LiTFSI with LiTFSI dissolved in polypropylene carbonate (PPC:LiTFSI) reduces interfacial resistance, and the resulting batteries show a greatly increased discharge capacity of approximately 20300 mAh g−1carbon and cycle 50 times while maintaining a cutoff capacity of 1000 mAh g−1carbon at 20 μA cm−2 and 80 °C. These results demonstrate that the use of LLZTO ceramic electrolytes enables operation of the Li-air battery in real air at medium temperatures, leading to a novel type of Li-air fuel cell battery for energy storage. PMID:28117359

  2. Morphology control of zinc regeneration for zinc-air fuel cell and battery

    Science.gov (United States)

    Wang, Keliang; Pei, Pucheng; Ma, Ze; Xu, Huachi; Li, Pengcheng; Wang, Xizhong

    2014-12-01

    Morphology control is crucial both for zinc-air batteries and for zinc-air fuel cells during zinc regeneration. Zinc dendrite should be avoided in zinc-air batteries and zinc pellets are yearned to be formed for zinc-air fuel cells. This paper is mainly to analyze the mechanism of shape change and to control the zinc morphology during charge. A numerical three-dimensional model for zinc regeneration is established with COMSOL software on the basis of ionic transport theory and electrode reaction electrochemistry, and some experiments of zinc regeneration are carried out. The deposition process is qualitatively analyzed by the kinetics Monte Carlo method to study the morphological change from the electrocrystallization point of view. Morphological evolution of deposited zinc under different conditions of direct currents and pulse currents is also investigated by simulation. The simulation shows that parametric variables of the flowing electrolyte, the surface roughness and the structure of the electrode, the charging current and mode affect morphological evolution. The uniform morphology of deposited zinc is attained at low current, pulsating current or hydrodynamic electrolyte, and granular morphology is obtained by means of an electrode of discrete columnar structure in combination with high current and flowing electrolyte.

  3. Prevalence of Zygomatic Air Cell Defect in adults—A retrospective panoramic radiographic analysis

    International Nuclear Information System (INIS)

    Patil, Karthikeya; Mahima, V.G.; Malleshi, Suchetha N.; Srikanth, H.S.

    2012-01-01

    Objectives: This research involved retrospectively evaluating panoramic radiographs of patients from India with the intention of assessing the prevalence of Zygomatic Air Cell Defect (ZACD) and establishing its dominant location and type. Methods: Seven thousand seven hundred and fifty-five panoramic radiographs of routine outpatients aged between 19 and 91 years were concomitantly evaluated by four investigators for estimating the prevalence and characteristics of the Zygomatic Air Cell Defect. Results: The prevalence of ZACD was noted to be 1.82%, with male preponderance. Unilateralality and multilocular appearance of ZACD were the dominant patterns observed. Conclusion: The frequency of ZACD amongst Indian population is in harmony with most of the similar studies conducted on various geographic populations.

  4. Environmental Assessment for Installation of a New Jet Engine Test Cell, Edwards Air Force Base, California

    Science.gov (United States)

    2012-09-01

    Acetal· Ethyle- Formal- Naph- Ethyle- Formal- Tested Power Setting h’"~ lbslhr’ dehyde Acrolein Ben~ene ben~ene dehyde thalene Scyrene Tolueue Xylenes...TIM Fuel Flow Engine!i per setting, .. I, Acetal- Ethyle- Formal- Naph- Ethyle- Formal- Tested Power Settin hours lb lhrl. dehyde Acrolein Benzene...ENVIRONMENTAL ASSESSMENT FOR INSTALLATION OF A NEW JET ENGINE TEST CELL EDWARDS AIR FORCE BASE, CALIFORNIA September

  5. Effect of Mixture Pressure and Equivalence Ratio on Detonation Cell Size for Hydrogen-Air Mixtures

    Science.gov (United States)

    2015-06-01

    mixture pressure detonation cell sizes are important for scaling the combustion chambers, and before this research no data existed for hydrogen and air...Introduction General Issue Pressure gain combustors have the potential to replace traditional combustions systems in gas turbine engines (Tellefsen et al... combustion has not been fully incorporated into turbine engines. In order to fully integrate RDEs into turbine engines, RDEs must be able to function

  6. Experimental investigation on a turbine compressor for air supply system of a fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Masayasu [Sumitomo Heavy Industries, Ltd., Yokosuka (Japan); Tsuchiyama, Syozo [Shipbuilding Research Association, Minato-ku, Tokyo (Japan)

    1996-12-31

    This report covers part of a joint study on a PEFC propulsion system for surface ships, summarized in a presentation to this Seminar, entitled {open_quotes}Study on a Polymer Electrolyte Fuel Cell (PEFC) Propulsion System for Surface Ships{close_quotes}, and which envisages application to a 1,500 DWT cargo vessel. The aspect treated here concerns a study on the air supply system for the PEFC, with particular reference to system components.

  7. Seeking effective dyes for a mediated glucose-air alkaline battery/fuel cell

    Science.gov (United States)

    Eustis, Ross; Tsang, Tsz Ming; Yang, Brigham; Scott, Daniel; Liaw, Bor Yann

    2014-02-01

    A significant level of power generation from an abiotic, air breathing, mediated reducing sugar-air alkaline battery/fuel cell has been achieved in our laboratories at room temperature without complicated catalysis or membrane separation in the reaction chamber. Our prior studies suggested that mass transport limitation by the mediator is a limiting factor in power generation. New and effective mediators were sought here to improve charge transfer and power density. Forty-five redox dyes were studied to identify if any can facilitate mass transport in alkaline electrolyte solution; namely, by increasing the solubility and mobility of the dye, and the valence charge carried per molecule. Indigo dyes were studied more closely to understand the complexity involved in mass transport. The viability of water-miscible co-solvents was also explored to understand their effect on solubility and mass transport of the dyes. Using a 2.0 mL solution, 20% methanol by volume, with 100 mM indigo carmine, 1.0 M glucose and 2.5 M sodium hydroxide, the glucose-air alkaline battery/fuel cell attained 8 mA cm-2 at short-circuit and 800 μW cm-2 at the maximum power point. This work shall aid future optimization of mediated charge transfer mechanism in batteries or fuel cells.

  8. From the Field to the Laboratory: Air Pollutant-Induced Genomic Effects in Lung Cells

    Directory of Open Access Journals (Sweden)

    William Vizuete

    2015-01-01

    Full Text Available Current in vitro studies do not typically assess cellular impacts in relation to real-world atmospheric mixtures of gases. In this study, we set out to examine the feasibility of measuring biological responses at the level of gene expression in human lung cells upon direct exposures to air in the field. This study describes the successful deployment of lung cells in the heavily industrialized Houston Ship Channel. By examining messenger RNA (mRNA levels from exposed lung cells, we identified changes in genes that play a role as inflammatory responders in the cell. The results show anticipated responses from negative and positive controls, confirming the integrity of the experimental protocol and the successful deployment of the in vitro instrument. Furthermore, exposures to ambient conditions displayed robust changes in gene expression. These results demonstrate a methodology that can produce gas-phase toxicity data in the field.

  9. The thymic orchestration involving Aire, miRNAs and cell-cell interactions during the induction of central tolerance

    Directory of Open Access Journals (Sweden)

    Geraldo eAleixo Passos

    2015-07-01

    Full Text Available Developing thymocytes interact sequentially with two distinct structures within the thymus: the cortex and medulla. Surviving single-positive and double-positive thymocytes from the cortex migrate into the medulla, where they interact with medullary thymic epithelial cells (mTECs. These cells ectopically express a vast set of peripheral tissue antigens (PTAs, a property termed promiscuous gene expression that is associated with the presentation of PTAs by mTECs to thymocytes. Thymocyte clones that have a high affinity for PTAs are eliminated by apoptosis in a process termed negative selection, which is essential for tolerance induction. The Aire gene is an important factor that controls the expression of a large set of PTAs. In addition to PTAs, Aire also controls the expression of miRNAs in mTECs. These miRNAs are important in the organization of the thymic architecture and act as posttranscriptional controllers of PTAs. Herein, we discuss recent discoveries and highlight open questions regarding the migration and interaction of developing thymocytes with thymic stroma, the ectopic expression of PTAs by mTECs, the association between Aire and miRNAs and its effects on central tolerance.

  10. Post-Aire maturation of thymic medullary epithelial cells involves selective expression of keratinocyte-specific autoantigens

    Directory of Open Access Journals (Sweden)

    Xiaoping eWang

    2012-03-01

    Full Text Available The autoimmune regulator (Aire-directed ectopic expression of tissue-specific antigens (TSAs by mature medullary thymic epithelial cells (mTECs has been viewed as an essential mechanism in the induction of central tolerance. Recent data suggest that the survival of mTECs extends beyond the Aire+ cell population to form the post-Aire mTEC population and Hassall's corpuscles (HCs. The nature and function of these post-Aire epithelial cells and structures, however, have remained unidentified. In this study, we characterized in detail the end-stage development of mTECs and HCs in both Aire-sufficient and Aire-deficient mice. In addition, using a transgenic mouse model in which the LacZ reporter gene is under the control of the endogenous Aire promoter, we purified and analyzed the post-Aire mTECs to characterize their function. We showed that the end-stage maturation of mTECs closely resembles that of keratinocytes and that the lack of Aire results in a marked block of mTEC differentiation, which is partially overcome by ligands for RANK and CD40. We also provide evidence that, during mTEC development, Aire is expressed only once and during a limited 1-2 day period. The following loss of Aire expression is accompanied by a quick downregulation of MHC class II and CD80, and of most of the Aire-dependent and Aire-independent TSAs, with the exception of keratinocyte-specific genes. In the final stage of maturation, the mTECs lose their nuclei to become HCs and specifically express desmogleins (DGs 1 and 3, which, via cross-presentation by APCs, may contribute to tolerance against these pemphigus vulgaris-related TSAs.

  11. Post-Aire Maturation of Thymic Medullary Epithelial Cells Involves Selective Expression of Keratinocyte-Specific Autoantigens

    Science.gov (United States)

    Wang, Xiaoping; Laan, Martti; Bichele, Rudolf; Kisand, Kai; Scott, Hamish S.; Peterson, Pärt

    2012-01-01

    The autoimmune regulator (Aire)-directed ectopic expression of tissue-specific antigens (TSAs) by mature medullary thymic epithelial cells (mTECs) has been viewed as an essential mechanism in the induction of central tolerance. Recent data suggest that the survival of mTECs extends beyond the Aire+ cell population to form the post-Aire mTEC population and Hassall’s corpuscles (HCs). The nature and function of these post-Aire epithelial cells and structures, however, have remained unidentified. In this study, we characterized in detail the end-stage development of mTECs and HCs in both Aire-sufficient and Aire-deficient mice. In addition, using a transgenic mouse model in which the LacZ reporter gene is under the control of the endogenous Aire promoter, we purified and analyzed the post-Aire mTECs to characterize their function. We showed that the end-stage maturation of mTECs closely resembles that of keratinocytes and that the lack of Aire results in a marked block of mTEC differentiation, which is partially overcome by ligands for RANK and CD40. We also provide evidence that, during mTEC development, Aire is expressed only once and during a limited 1–2 day period. The following loss of Aire expression is accompanied by a quick downregulation of MHC class II and CD80, and of most of the Aire-dependent and Aire-independent TSAs, with the exception of keratinocyte-specific genes. In the final stage of maturation, the mTECs lose their nuclei to become HCs and specifically express desmogleins (DGs) 1 and 3, which, via cross-presentation by APCs, may contribute to tolerance against these pemphigus vulgaris-related TSAs. PMID:22448160

  12. Potentially Pathogenic Bacteria in Shower Water and Air of a Stem Cell Transplant Unit▿

    Science.gov (United States)

    Perkins, Sarah D.; Mayfield, Jennie; Fraser, Victoria; Angenent, Largus T.

    2009-01-01

    Potential pathogens from shower water and aerosolized shower mist (i.e., shower aerosol) have been suggested as an environmental source of infection for immunocompromised patients. To quantify the microbial load in shower water and aerosol samples, we used culture, microscopic, and quantitative PCR methods to investigate four shower stalls in a stem cell transplant unit at Barnes-Jewish Hospital in St. Louis, MO. We also tested membrane-integrated showerheads as a possible mitigation strategy. In addition to quantification, a 16S rRNA gene sequencing survey was used to characterize the abundant bacterial populations within shower water and aerosols. The average total bacterial counts were 2.2 × 107 cells/liter in shower water and 3.4 × 104 cells/m3 in shower aerosol, and these counts were reduced to 6.3 × 104 cells/liter (99.6% efficiency) and 8.9 × 103 cells/m3 (82.4% efficiency), respectively, after membrane-integrated showerheads were installed. Potentially pathogenic organisms were found in both water and aerosol samples from the conventional showers. Most notable was the presence of Mycobacterium mucogenicum (99.5% identity) in the water and Pseudomonas aeruginosa (99.3% identity) in the aerosol samples. Membrane-integrated showerheads may protect immunocompromised patients from waterborne infections in a stem cell transplant unit because of efficient capture of vast numbers of potentially pathogenic bacteria from hospital water. However, an in-depth epidemiological study is necessary to investigate whether membrane-integrated showerheads reduce hospital-acquired infections. The microbial load in shower aerosols with conventional showerheads was elevated compared to the load in HEPA-filtered background air in the stem cell unit, but it was considerably lower than typical indoor air. Thus, in shower environments without HEPA filtration, the increase in microbial load due to shower water aerosolization would not have been distinguishable from anticipated

  13. Using cathode spacers to minimize reactor size in air cathode microbial fuel cells

    KAUST Repository

    Yang, Qiao

    2012-04-01

    Scaling up microbial fuel cells (MFCs) will require more compact reactor designs. Spacers can be used to minimize the reactor size without adversely affecting performance. A single 1.5mm expanded plastic spacer (S1.5) produced a maximum power density (973±26mWm -2) that was similar to that of an MFC with the cathode exposed directly to air (no spacer). However, a very thin spacer (1.3mm) reduced power by 33%. Completely covering the air cathode with a solid plate did not eliminate power generation, indicating oxygen leakage into the reactor. The S1.5 spacer slightly increased columbic efficiencies (from 20% to 24%) as a result of reduced oxygen transfer into the system. Based on operating conditions (1000ς, CE=20%), it was estimated that 0.9Lh -1 of air would be needed for 1m 2 of cathode area suggesting active air flow may be needed for larger scale MFCs. © 2012 Elsevier Ltd.

  14. Capacitive micromachined ultrasonic transducers based on annular cell geometry for air-coupled applications.

    Science.gov (United States)

    Na, Shuai; Chen, Albert I H; Wong, Lawrence L P; Li, Zhenhao; Macecek, Mirek; Yeow, John T W

    2016-09-01

    A novel design of an air-coupled capacitive micromachined ultrasonic transducer (CMUT) with annular cell geometry (annular CMUT) is proposed. Finite element analysis shows that an annular cell has a ratio of average-to-maximum displacement (RAMD) of 0.52-0.58 which is 58-76% higher than that of a conventional circular cell. The increased RAMD leads to a larger volume displacement which results in a 48.4% improved transmit sensitivity and 127.3% improved power intensity. Single-cell annular CMUTs were fabricated with 20-μm silicon plates on 13.7-μm deep and 1.35-mm wide annular cavities using the wafer bonding technique. The measured RAMD of the fabricated CMUTs is 0.54. The resonance frequency was measured to be 94.5kHz at 170-V DC bias. The transmit sensitivity was measured to be 33.83Pa/V and 25.85Pa/V when the CMUT was excited by a continuous wave and a 20-cycle burst, respectively. The receive sensitivity at 170-V DC bias was measured to be 7.7mV/Pa for a 20-cycle burst, and 15.0mV/Pa for a continuous incident wave. The proposed annular CMUT design demonstrates a significant improvement in transmit efficiency, which is an important parameter for air-coupled ultrasonic transducers. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Fuel Cell Propulsion Systems for an All-electric Personal Air Vehicle

    Science.gov (United States)

    Kohout, Lisa L.; Schmitz, Paul C.

    2003-01-01

    There is a growing interest in the use of fuel cells as a power source for all-electric aircraft propulsion as a means to substantially reduce or eliminate environmentally harmful emissions. Among the technologies under consideration for these concepts are advanced proton exchange membrane and solid oxide fuel cells, alternative fuels and fuel processing, and fuel storage. This paper summarizes the results of a first-order feasibility study for an all-electric personal air vehicle utilizing a fuel cell-powered propulsion system. A representative aircraft with an internal combustion engine was chosen as a baseline to provide key parameters to the study, including engine power and subsystem mass, fuel storage volume and mass, and aircraft range. The engine, fuel tank, and associated ancillaries were then replaced with a fuel cell subsystem. Various configurations were considered including: a proton exchange membrane (PEM) fuel cell with liquid hydrogen storage; a direct methanol PEM fuel cell; and a direct internal reforming solid oxide fuel cell (SOFC)/turbine hybrid system using liquid methane fuel. Each configuration was compared to the baseline case on a mass and range basis.

  16. Temperature dependence of an abiotic glucose/air alkaline fuel cell

    Science.gov (United States)

    Orton, Dane; Scott, Daniel

    2015-11-01

    The temperature dependence of a previously developed glucose fuel cell is explored. This cell uses a small molecule dye mediator to transport oxidizable electrons from glucose to a carbon felt anode. This reaction is driven by an air breathing MnO2 cathode. This research investigates how the temperature of the system affects the power production of the fuel cell. Cell performance is observed using either methyl viologen, indigo carmine, trypan blue, or hydroquinone as a mediator at temperatures of 15, 19, 27, 32, 37, 42, and 49 °C. Cyclic voltammetry of the cell anode at the given temperatures with the individual dyes is also presented. The highest power production amongst all of the cells occurs at 32 °C. This occurs with the mediator indigo carmine or with the mediator methyl viologen. These sustained powers are 2.31 mW cm-2 and 2.39 mW cm-2, respectively. This is approximately a 350% increase for these cells compared to their power produced at room temperature. This dramatic increase is likely due to increased solubility of the mediator dye at higher temperatures.

  17. Mouse thymic epithelial cell lines expressing "Aire" and peripheral tissue-specific antigens reproduce in vitro negative selection of T cells.

    Science.gov (United States)

    Yamaguchi, Yoshitaka; Takayanagi, Atsushi; Chen, Jiabing; Sakai, Kosuke; Kudoh, Jun; Shimizu, Nobuyoshi

    2011-08-15

    In the human thymus, AIRE (autoimmune regulator) gene is expressed in a very limited type of medullary thymic epithelial cells (mTECs) and no cognate cell lines are available, hence the molecular analysis of AIRE gene function has been difficult. To improve this situation, we attempted to isolate Aire-expressing cells and established three cell lines (Aire⁺TEC1, Aire⁺TEC2, Aire⁺DC) from the abnormally enlarged thymus, which was developed in the transgenic mice expressing SV40 T-antigen driven by the mouse Aire gene promoter. When these Aire⁺ cell lines were co-cultured with fresh thymocytes, they adhered to the majority of thymocytes and induced apoptosis as if negative selection of T-cells in the thymus is occurring in vitro. Further analysis revealed that these Aire⁺ cell lines are derived from mTECs and exhibit characteristic natures of "antigen presenting cells" including several distinct abilities: to express a variety of peripheral tissue-specific antigens, to produce immunoproteasome and immunological synapse, and to express some of TNFSFs (tumor necrosis factor super families). Thus, the newly established Aire⁺ cell lines will be invaluable for the further detailed analysis of AIRE gene function in the central tolerance of immunity and autoimmune disease. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Dissolved air flotation and centrifugation as methods for oil recovery from ruptured microalgal cells.

    Science.gov (United States)

    Ghasemi Naghdi, Forough; Schenk, Peer M

    2016-10-01

    Solvent-free microalgal lipid recovery is highly desirable for safer, more sustainable and more economical microalgal oil production. Dispersed air flotation and centrifugation were evaluated for the ability to separate oil and debris from a slurry mixture of osmotically fractured Chaetoceros muelleri cells with and without utilizing collectors. Microalgal oil partially phase-separated as a top layer and partially formed an oil-in-water emulsion. Although collectors, such as sodium dodecyl sulphate enhanced selective flotation, by just adjusting the pH and cell concentration of the mixture, up to 78% of the lipids were recovered in the froth. Using centrifugation of fractured microalgal slurry resulted in removal of 60% cell debris and up to 68.5% of microalgal oil was present in the supernatant. Both methods, centrifugation and flotation provided options for separation of microalgal oil from C. muelleri slurry with similar fatty acid recoveries of 57% and 60%, respectively. Copyright © 2016. Published by Elsevier Ltd.

  19. Quantification of carbon dioxide poisoning in air breathing alkaline fuel cells

    Science.gov (United States)

    Tewari, A.; Sambhy, V.; Urquidi Macdonald, M.; Sen, A.

    Carbon dioxide intolerance has impeded the development of alkaline fuel cells as an alternate source of power supply. The CO 2, in a fuel cell system, could come from the anode side (if "dirty" H 2 is used as fuel), from the cathode side (if air instead of pure O 2 is used as an oxidant) or from inside the electrolyte (if methanol is used as a fuel). In this work, an novel analytical approach is proposed to study and quantify the carbon dioxide poisoning problem. Accelerated tests were carried out in an alkaline fuel cell using methanol as a fuel with different electrical loads and varying the concentration of carbon dioxide in a mixture CO 2/O 2 used as oxidant. Two characteristic quantities, t max and R max, were specified which were shown to comprehensively define the nature and extent of carbon dioxide poisoning in alkaline fuel cells. The poisoning phenomenon was successfully quantified by determining the dependence of these characteristic quantities on the operating parameters, viz. atmospheric carbon dioxide concentration and applied electrical load. Such quantification enabled the prediction of the output of a fuel cell operating in a carbon dioxide enriched atmosphere. In addition, static and dynamic analyses of electrolytes were carried out to determine the dependence of cell current on the electrolyte composition in a fuel cell undergoing poisoning. It was observed that there is a critical concentration of KOH in the electrolyte only below which the effect of carbon dioxide poisoning is reflected on the cell performance. Potentiostatic polarization tests confirmed that the underlying reason for the decreased cell performance because of carbon dioxide poisoning is the sluggish kinetics of methanol oxidation in the presence of potassium carbonate in the electrolyte. Moreover, the decreased conductivity of the electrolyte resulting from hydroxide to carbonate conversion was also shown to increase the ohmic loses in an alkaline fuel cell leading to lower

  20. Determining air quality and greenhouse gas impacts of hydrogen infrastructure and fuel cell vehicles.

    Science.gov (United States)

    Stephens-Romero, Shane; Carreras-Sospedra, Marc; Brouwer, Jacob; Dabdub, Donald; Samuelsen, Scott

    2009-12-01

    Adoption of hydrogen infrastructure and hydrogen fuel cell vehicles (HFCVs) to replace gasoline internal combustion engine (ICE) vehicles has been proposed as a strategy to reduce criteria pollutant and greenhouse gas (GHG) emissions from the transportation sector and transition to fuel independence. However, it is uncertain (1) to what degree the reduction in criteria pollutants will impact urban air quality, and (2) how the reductions in pollutant emissions and concomitant urban air quality impacts compare to ultralow emission gasoline-powered vehicles projected for a future year (e.g., 2060). To address these questions, the present study introduces a "spatially and temporally resolved energy and environment tool" (STREET) to characterize the pollutant and GHG emissions associated with a comprehensive hydrogen supply infrastructure and HFCVs at a high level of geographic and temporal resolution. To demonstrate the utility of STREET, two spatially and temporally resolved scenarios for hydrogen infrastructure are evaluated in a prototypical urban airshed (the South Coast Air Basin of California) using geographic information systems (GIS) data. The well-to-wheels (WTW) GHG emissions are quantified and the air quality is established using a detailed atmospheric chemistry and transport model followed by a comparison to a future gasoline scenario comprised of advanced ICE vehicles. One hydrogen scenario includes more renewable primary energy sources for hydrogen generation and the other includes more fossil fuel sources. The two scenarios encompass a variety of hydrogen generation, distribution, and fueling strategies. GHG emissions reductions range from 61 to 68% for both hydrogen scenarios in parallel with substantial improvements in urban air quality (e.g., reductions of 10 ppb in peak 8-h-averaged ozone and 6 mug/m(3) in 24-h-averaged particulate matter concentrations, particularly in regions of the airshed where concentrations are highest for the gasoline scenario).

  1. Aire Downregulation Is Associated with Changes in the Posttranscriptional Control of Peripheral Tissue Antigens in Medullary Thymic Epithelial Cells

    OpenAIRE

    Oliveira, Ernna H.; Macedo, Claudia; Collares, Cristhianna V.; Freitas, Ana Carolina; Donate, Paula Barbim; Sakamoto-Hojo, Elza T.; Donadi, Eduardo A.; Passos, Geraldo A.

    2016-01-01

    Autoimmune regulator (Aire) is a transcriptional regulator of peripheral tissue antigens (PTAs) and microRNAs (miRNAs) in medullary thymic epithelial cells (mTECs). In this study, we tested the hypothesis that Aire also played a role as an upstream posttranscriptional controller in these cells and that variation in its expression might be associated with changes in the interactions between miRNAs and the mRNAs encoding PTAs. We demonstrated that downregulation of Aire in vivo in the thymuses ...

  2. Compact modeling of a telecom back-up unit powered by air-cooled proton exchange membrane fuel cell

    DEFF Research Database (Denmark)

    Gao, Xin; Kær, Søren Knudsen

    2018-01-01

    Applications of proton exchange membrane fuel cells (PEMFC’s) are expanding in portable, automotive and stationary markets. One promising application is the back-up power for telecommunication applications in remote areas where usually air-cooled PMEFC’s are used. An air-cooled PEMFC system is much...... simpler and cheaper while the stack performance is substantially lower. The thermal management of an air-cooled PEMFC stack is critical. A large amount of heat is side-produced with power and has to be effectively removed by excessive air fed to the stack cathode. This work explores the challenge via...... compact modeling of an air-cooled PEMFC powered telecom back-up system. The presented computational fluid dynamics (CFD) model is three-dimensional (3D), and is based on the commercial CFD package Fluent (ANSYS Inc.). The fuel cell stack is simulated as an anisotropic porous medium and the spatial...

  3. Zinc-air cell with KOH-treated agar layer between electrode and electrolyte containing hydroponics gel

    Energy Technology Data Exchange (ETDEWEB)

    Otham, R. [International Islamic University, Kuala Lumpur (Malaysia); Yahaya, A. H. [University of Malaya, Dept. of Chemistry, Kuala Lumpur (Malaysia); Arof, A. K. [University of Malaya, Dept. of Physics, Kuala Lumpur (Malaysia)

    2002-07-01

    Zinc-air electrochemical power sources possess the highest density compared to other zinc anode batteries, due their free and unlimited supply from the ambient air. In this experiment zinc-air cells have been fabricated employing hydroponics gel as an alternative alkaline electrolyte gelling agent. Thin KOH-treated agar layer was applied between the electrode-electrolyte interfaces which produced significant enhancement of the cells' capacities, indicating that the application of thin agar layer will improve the electrode-gelled electrolyte interfaces. Promising results have been achieved with porous zinc anode prepared from dried zinc-graphite-gelatinized agar paste; e g. a zinc-air cell employing a porous zinc anode has demonstrated a capacity of 1470 mAh rated at 0.1 A continuous discharge. 32 refs., 9 figs.

  4. Zygomatic air cell defect: A panoramic radiographic study of a south Indian population

    International Nuclear Information System (INIS)

    Hs, Srikanth; Patil, Karthikeya; Vg, Mahima

    2010-01-01

    To determine the prevalence, patterns of occurrence and variations of zygomatic air cell defects (ZACDs) using panoramic radiographs. Dental panoramic radiographs of 600 outpatients were examined to evaluate the variations and characteristics of ZACDs. ZACDs were identified in 15 subjects out of 600, giving an overall prevalence of 2.5%. Seven ZACDs were seen in males and eight in females. Among the 15 ZACDs, nine were unilateral and six were bilateral. The overall prevalence of ZACD is relatively low in south Indian population and careful radiographic evaluation is needed to detect these entities

  5. Air pollution effects on the ultrastructure of Phlomis fruticosa mesophyll cells

    Energy Technology Data Exchange (ETDEWEB)

    Psaras, G.K.; Christodoulakis, N.S.

    1987-04-01

    Plant physiologists and environmental scientists suggest that a basic effect of air pollution on plants leads towards the minimization of their productivity. On the other hand the action of individual pollutants on intact plants has been studied from biochemical as well as structural viewpoint. Thus the study of plant responses to SO/sub 2/ exposure revealed that this agent causes acute and chronic injury. Chronic injury results in chlorosis and subsequent necrosis due to destruction of chlorophylls and final chloroplast lysis. It has been documented that ultrastructural characteristics of leaves are affected prior to any visible injury. Electron microscope examination of SO/sub 2/ fumigated plant-attached leaves of Vicia faba revealed chloroplast thylakoids starting to swell whilst photosynthesis rate was drastically reduced. The first light microscope-detected effects of air pollution on the leaf structure of plants common in natural ecosystems of Athens metropolitan area, have been reported. A chlorosis phenomenon in Urginea maritima leaves as well as an indication of detrimental effects of Phlomis fruticosa mesophyll chloroplasts were documented. In this work further investigation has been undertaken in order to elucidate the precise effects of air pollution on the ultrastructure of the photosynthesizing mesophyll cells.

  6. High-Performance Carbon Aerogel Air Cathodes for Microbial Fuel Cells.

    Science.gov (United States)

    Zhang, Xiaoyuan; He, Weihua; Zhang, Rufan; Wang, Qiuying; Liang, Peng; Huang, Xia; Logan, Bruce E; Fellinger, Tim-Patrick

    2016-10-06

    Microbial fuel cells (MFCs) can generate electricity from the oxidation of organic substrates using anodic exoelectrogenic bacteria and have great potential for harvesting electric energy from wastewater. Improving oxygen reduction reaction (ORR) performance at a neutral pH is needed for efficient energy production. Here we show a nitrogen doped (≈4 wt%) ionothermal carbon aerogel (NDC) with a high surface area, large pore volume, and hierarchical porosity, with good electrocatalytic properties for ORR in MFCs. The MFCs using NDC air cathodes achieved a high maximum power density of 2300 mW m -2 , which was 1.7 times higher than the most commonly used Pt/C air cathodes and also higher than most state-of-the-art ORR catalyst air cathodes. Rotating disk electrode measurements verified the superior electrocatalytic activity of NDC with an efficient four-electron transfer pathway (n=3.9). These findings highlight NDC as a better-performing and cost-efficient catalyst compared with Pt/C, making it highly viable for MFC applications. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Power generation by packed-bed air-cathode microbial fuel cells

    KAUST Repository

    Zhang, Xiaoyuan

    2013-08-01

    Catalysts and catalyst binders are significant portions of the cost of microbial fuel cell (MFC) cathodes. Many materials have been tested as aqueous cathodes, but air-cathodes are needed to avoid energy demands for water aeration. Packed-bed air-cathodes were constructed without expensive binders or diffusion layers using four inexpensive carbon-based materials. Cathodes made from activated carbon produced the largest maximum power density of 676±93mW/m2, followed by semi-coke (376±47mW/m2), graphite (122±14mW/m2) and carbon felt (60±43mW/m2). Increasing the mass of activated carbon and semi-coke from 5 to ≥15g significantly reduced power generation because of a reduction in oxygen transfer due to a thicker water layer in the cathode (~3 or ~6cm). These results indicate that a thin packed layer of activated carbon or semi-coke can be used to make inexpensive air-cathodes for MFCs. © 2013 Elsevier Ltd.

  8. Performance of air-cathode stacked microbial fuel cells systems for wastewater treatment and electricity production.

    Science.gov (United States)

    Estrada-Arriaga, Edson Baltazar; Guillen-Alonso, Yvonne; Morales-Morales, Cornelio; García-Sánchez, Liliana; Bahena-Bahena, Erick Obed; Guadarrama-Pérez, Oscar; Loyola-Morales, Félix

    2017-07-01

    Two different air-cathode stacked microbial fuel cell (MFC) configurations were evaluated under continuous flow during the treatment of municipal wastewater and electricity production at a hydraulic retention time (HRT) of 3, 1, and 0.5 d. Stacked MFC 1 was formed by 20 individual air-cathode MFC units. The second stacked MFC (stacked MFC 2) consisted of 40 air-cathode MFC units placed in a shared reactor. The maximum voltages produced at closed circuit (1,000 Ω) were 170 mV for stacked MFC 1 and 94 mV for stacked MFC 2. Different power densities in each MFC unit were obtained due to a potential drop phenomenon and to a change in chemical oxygen demand (COD) concentrations inside reactors. The maximum power densities from individual MFC units were up to 1,107 mW/m 2 for stacked MFC 1 and up to 472 mW/m 2 for stacked MFC 2. The maximum power densities in stacked MFC 1 and MFC 2 connected in series were 79 mW/m 2 and 4 mW/m 2 , respectively. Electricity generation and COD removal efficiencies were reduced when the HRT was decreased. High removal efficiencies of 84% of COD, 47% of total nitrogen, and 30% of total phosphorus were obtained during municipal wastewater treatment.

  9. High-Performance Carbon Aerogel Air Cathodes for Microbial Fuel Cells

    KAUST Repository

    Zhang, Xiaoyuan

    2016-08-11

    Microbial fuel cells (MFCs) can generate electricity from the oxidation of organic substrates using anodic exoelectrogenic bacteria and have great potential for harvesting electric energy from wastewater. Improving oxygen reduction reaction (ORR) performance at a neutral pH is needed for efficient energy production. Here we show a nitrogen doped (≈4 wt%) ionothermal carbon aerogel (NDC) with a high surface area, large pore volume, and hierarchical porosity, with good electrocatalytic properties for ORR in MFCs. The MFCs using NDC air cathodes achieved a high maximum power density of 2300 mW m−2, which was 1.7 times higher than the most commonly used Pt/C air cathodes and also higher than most state-of-the-art ORR catalyst air cathodes. Rotating disk electrode measurements verified the superior electrocatalytic activity of NDC with an efficient four-electron transfer pathway (n=3.9). These findings highlight NDC as a better-performing and cost-efficient catalyst compared with Pt/C, making it highly viable for MFC applications.

  10. Power, heat and chilliness with natural gas - fuel cells and air conditioning

    International Nuclear Information System (INIS)

    Krein, Stephan; Ruehling, Karin

    1999-01-01

    A new and innovative concept of the supply with power, heat and chilliness will realise in the new Malteser-hospital in Kamenz. The core of this demonstration-plant are a fuel cell, an adsorption cooling machine as well as multi-solar collectors. The fuel cell has two goals. Primary it produces power for the own demand. The selected dimension guarantees, that the power will consume nearly continuously. Secondly the produced heat of the fuel cell (and the solar-heat too) will use for heating and preparation of warm water. In the summer, the heat will use for the adsorption cooling machine, which produces chilliness for air-conditioning. The advantage in the face of common concepts of combining power and heat is the high-efficiently use of the fuel-energy for electric power generation on the one hand. Fuel cells work with high efficiency also at partial load. On the other hand, with the adsorption cooling machine the produced heat of fuel cell and multi-solar collectors can be used also in the summer. First experiences with this concept show, that an optimised co-operation of the components with an adaptive, self-learning control system based on the weather forecast as well as various storages for heat and chilliness can be achieve. A continuously operation, high fuel utilisation and reduced environmental pollution can be demonstrated. (author)

  11. A Janus-paper PDMS platform for air-liquid interface cell culture applications

    Science.gov (United States)

    Rahimi, Rahim; Ochoa, Manuel; Donaldson, Amy; Parupudi, Tejasvi; Dokmeci, Mehmet R.; Khademhosseini, Ali; Ghaemmaghami, Amir; Ziaie, Babak

    2015-05-01

    A commercially available Janus paper with one hydrophobic (polyethylene-coated) face and a hygroscopic/hydrophilic one is irreversibly bonded to a polydimethylsiloxane (PDMS) substrate incorporating microfluidic channels via corona discharge surface treatment. The bond strength between the polymer-coated side and PDMS is characterized as a function of corona treatment time and annealing temperature/time. A maximum strength of 392 kPa is obtained with a 2 min corona treatment followed by 60 min of annealing at 120 °C. The water contact angle of the corona-treated polymer side decreases with increased discharge duration from 98° to 22°. The hygroscopic/hydrophilic side is seeded with human lung fibroblast cells encapsulated in a methacrylated gelatin (GelMA) hydrogel to show the potential of this technology for nutrient and chemical delivery in an air-liquid interface cell culture.

  12. Inkjet Impregnation for Tailoring Air Electrode Microstructure to Improve Solid Oxide Cells Performance

    KAUST Repository

    Da’as, Eman H.

    2015-09-30

    The urge to lower the operating temperature of solid oxide cells (SOCs) to the intermediate ranges between 500-700°C motivated the research into impregnation processes, which offer highly efficient SOC air electrodes at low operating temperatures. Lack of controllability and reproducibility of this technique in the conventional way is still considered as an inadequacy for industrialization since it is performed manually. Therefore, inkjet-printing technology was proposed as an adequate approach to perform scalable and controllable impregnation for SOC air electrodes, which in turn leads to low operating temperatures. Composite LSM-ionic conductive air electrodes of weight ratio 1:2 were fabricated by inkjet impregnation of lanthanum strontium manganite (La0.8Sr0.2MnO3) precursor nitrates onto a porous ionic conductive backbone structure. First, porous yttria stabilized zirconia (8YSZ) substrates prepared by tape casting were used to study the influence of the printing parameters on the lateral dispersion and penetration of LSM ink inside the pores. XRD analysis confirmed the formation of LSM phase after calcination at 800°C for 2 h, while SEM revealed the formation of LSM nanostructures. It has been found by optical microscope observations that the spacing between the drops and the substrate temperature have a significant role in controlling the printing process. Next, the optimized printing parameters were applied in the inkjet impregnation of the LSM ink into porous YSZ electrodes that were spin coated on both sides of dense YSZ layers. LSM-YSZ composite air electrodes achieved an area specific resistance (ASR) of around 0.29 Ω.cm2 at 700°C. The performance of LSM-YSZ composite electrodes was influenced by the microstructure and the thickness, and by the electrode/electrolyte interface characteristics. As a result, the enhancement in LSM-YSZ composite electrode performance was observed due to the better percolation in LSM, YSZ and oxygen diffusion. Finally

  13. Divergent effects of T cell costimulation and inflammatory cytokine production on autoimmune peripheral neuropathy provoked by Aire deficiency.

    Science.gov (United States)

    Zeng, Xiaopei L; Nagavalli, Anil; Smith, Colin-Jamal; Howard, James F; Su, Maureen A

    2013-04-15

    Chronic inflammatory demyelinating polyneuropathy results from autoimmune destruction of the peripheral nervous system and is a component of the multiorgan autoimmunity syndrome that results from Aire gene mutations in humans. In parallel, peripheral nervous system autoimmunity resembling chronic inflammatory demyelinating polyneuropathy develops spontaneously in NOD mice with a partial loss of Aire function (NOD.Aire(GW/+) mice) and is a T cell-mediated disease. In this study, we analyze how key aspects of T cell activation and function modulate disease development in Aire-deficient mice. We show that genetic ablation of the Th1 cytokine IFN-γ completely prevents clinical and electrophysiological evidence of neuropathy in NOD.Aire(GW/+) mice. IFN-γ deficiency is associated with absence of immune infiltration and decreased expression of the T cell chemoattractant IP-10 in sciatic nerves. Thus, IFN-γ is absolutely required for the development of autoimmune peripheral neuropathy in NOD.Aire(GW/+) mice. Because IFN-γ secretion is enhanced by B7-CD28 costimulation of T cells, we sought to determine the effects of these costimulatory molecules on neuropathy development. Surprisingly, B7-2 deficiency accelerated neuropathy development in NOD.Aire(GW/+) mice, and Ab blockade of both B7-1 and B7-2 resulted in fulminant, early-onset neuropathy. Thus, in contrast to IFN-γ, B7-2 alone and B7-1/B7-2 in combination function to ameliorate neuropathy development in NOD.Aire(GW/+) mice. Together, these findings reveal distinct and opposing effects of the T cell costimulatory pathway and IFN-γ production on the pathogenesis of autoimmune peripheral neuropathy.

  14. Potentially pathogenic bacteria in shower water and air of a stem cell transplant unit.

    Science.gov (United States)

    Perkins, Sarah D; Mayfield, Jennie; Fraser, Victoria; Angenent, Largus T

    2009-08-01

    Potential pathogens from shower water and aerosolized shower mist (i.e., shower aerosol) have been suggested as an environmental source of infection for immunocompromised patients. To quantify the microbial load in shower water and aerosol samples, we used culture, microscopic, and quantitative PCR methods to investigate four shower stalls in a stem cell transplant unit at Barnes-Jewish Hospital in St. Louis, MO. We also tested membrane-integrated showerheads as a possible mitigation strategy. In addition to quantification, a 16S rRNA gene sequencing survey was used to characterize the abundant bacterial populations within shower water and aerosols. The average total bacterial counts were 2.2 x 10(7) cells/liter in shower water and 3.4 x 10(4) cells/m(3) in shower aerosol, and these counts were reduced to 6.3 x 10(4) cells/liter (99.6% efficiency) and 8.9 x 10(3) cells/m(3) (82.4% efficiency), respectively, after membrane-integrated showerheads were installed. Potentially pathogenic organisms were found in both water and aerosol samples from the conventional showers. Most notable was the presence of Mycobacterium mucogenicum (99.5% identity) in the water and Pseudomonas aeruginosa (99.3% identity) in the aerosol samples. Membrane-integrated showerheads may protect immunocompromised patients from waterborne infections in a stem cell transplant unit because of efficient capture of vast numbers of potentially pathogenic bacteria from hospital water. However, an in-depth epidemiological study is necessary to investigate whether membrane-integrated showerheads reduce hospital-acquired infections. The microbial load in shower aerosols with conventional showerheads was elevated compared to the load in HEPA-filtered background air in the stem cell unit, but it was considerably lower than typical indoor air. Thus, in shower environments without HEPA filtration, the increase in microbial load due to shower water aerosolization would not have been distinguishable from

  15. Thermal investigation of lithium-ion battery module with different cell arrangement structures and forced air-cooling strategies

    International Nuclear Information System (INIS)

    Wang, Tao; Tseng, K.J.; Zhao, Jiyun; Wei, Zhongbao

    2014-01-01

    Highlights: • Three-dimensional CFD model with forced air cooling are developed for battery modules. • Impact of different air cooling strategies on module thermal characteristics are investigated. • Impact of different model structures on module thermal responses are investigated. • Effect of inter-cell spacing on cell thermal characteristics are also studied. • The optimal battery module structure and air cooling strategy is recommended. - Abstract: Thermal management needs to be carefully considered in the lithium-ion battery module design to guarantee the temperature of batteries in operation within a narrow optimal range. This article firstly explores the thermal performance of battery module under different cell arrangement structures, which includes: 1 × 24, 3 × 8 and 5 × 5 arrays rectangular arrangement, 19 cells hexagonal arrangement and 28 cells circular arrangement. In addition, air-cooling strategies are also investigated by installing the fans in the different locations of the battery module to improve the temperature uniformity. Factors that influence the cooling capability of forced air cooling are discussed based on the simulations. The three-dimensional computational fluid dynamics (CFD) method and lumped model of single cell have been applied in the simulation. The temperature distributions of batteries are quantitatively described based on different module patterns, fan locations as well as inter-cell distance, and the conclusions are arrived as follows: when the fan locates on top of the module, the best cooling performance is achieved; the most desired structure with forced air cooling is cubic arrangement concerning the cooling effect and cost, while hexagonal structure is optimal when focus on the space utilization of battery module. Besides, the optimized inter-cell distance in battery module structure has been recommended

  16. Gas Diffusion Electrodes Manufactured by Casting Evaluation as Air Cathodes for Microbial Fuel Cells (MFC

    Directory of Open Access Journals (Sweden)

    Sandipam Srikanth

    2016-07-01

    Full Text Available One of the most intriguing renewable energy production methods being explored currently is electrical power generation by microbial fuel cells (MFCs. However, to make MFC technology economically feasible, cost efficient electrode manufacturing processes need to be proposed and demonstrated. In this context, VITO has developed an innovative electrode manufacturing process based on film casting and phase inversion. The screening and selection process of electrode compositions was done based on physicochemical properties of the active layer, which in turn maintained a close relation with their composition A dual hydrophilic-hydrophobic character in the active layer was achieved with values of εhydrophilic up to 10% while εTOTAL remained in the range 65 wt % to 75 wt %. Eventually, selected electrodes were tested as air cathodes for MFC in half cell and full cell modes. Reduction currents, up to −0.14 mA·cm2− at −100 mV (vs. Ag/AgCl were reached in long term experiments in the cathode half-cell. In full MFC, a maximum power density of 380 mW·m−2 was observed at 100 Ω external load.

  17. Contrasting models for the roles of Aire in the differentiation program of epithelial cells in the thymic medulla.

    Science.gov (United States)

    Matsumoto, Mitsuru

    2011-01-01

    The current prevailing view regarding the role of Aire in self-tolerance is that it is involved in the transcriptional control of many tissue-restricted self-antigen genes in thymic epithelial cells in the medulla (mTECs); however, accumulating evidence also suggests that Aire has other roles, e.g. in mTEC differentiation, and furthermore that Aire can either promote or inhibit the mTEC differentiation program, i.e. Aire does not play a neutral role in mTEC differentiation. This review discusses when and how Aire plays an important role in controlling the organization of mTECs required for the expression of self-antigen genes. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Aire downregulation is associated with changes in the posttranscriptional control of peripheral tissue antigens in medullary thymic epithelial cells.

    Directory of Open Access Journals (Sweden)

    Ernna Hérida Oliveira

    2016-11-01

    Full Text Available Autoimmune regulator (Aire is a transcriptional regulator of peripheral tissue antigens (PTAs and microRNAs (miRNAs in medullary thymic epithelial cells (mTECs. In this study, we tested the hypothesis that Aire also played a role as an upstream posttranscriptional controller in these cells and that variation in its expression might be associated with changes in the interactions between miRNAs and the mRNAs encoding PTAs. We demonstrated that downregulation of Aire in vivo in the thymuses of BALB/c mice imbalanced the large-scale expression of these two RNA species and consequently their interactions. The expression profiles of a large set of mTEC miRNAs and mRNAs isolated from the thymuses of mice subjected (or not to small-interfering (siRNA-induced Aire gene knockdown revealed that 87 miRNAs and 4,558 mRNAs were differentially expressed. The reconstruction of the miRNA-mRNA interaction networks demonstrated that interactions between these RNAs were under Aire influence and therefore changed when this gene was downregulated. Prior to Aire knockdown, only members of the miR-let-7 family interacted with a set of PTA mRNAs. Under Aire knockdown conditions, a larger set of miRNA families and their members established this type of interaction. Notably, no previously described Aire-dependent PTA interacted with the miRNAs, indicating that these PTAs were somehow refractory. The miRNA-mRNA interactions were validated by calculating the minimal free energy of the pairings between the miRNA seed regions and the mRNA 3´ UTRs and within the cellular milieu using the luciferase reporter gene assay. These results suggest the existence of a link between transcriptional and posttranscriptional control because Aire downregulation alters the miRNA-mRNA network controlling PTAs in mTEC cells.

  19. Aire Downregulation Is Associated with Changes in the Posttranscriptional Control of Peripheral Tissue Antigens in Medullary Thymic Epithelial Cells.

    Science.gov (United States)

    Oliveira, Ernna H; Macedo, Claudia; Collares, Cristhianna V; Freitas, Ana Carolina; Donate, Paula Barbim; Sakamoto-Hojo, Elza T; Donadi, Eduardo A; Passos, Geraldo A

    2016-01-01

    Autoimmune regulator (Aire) is a transcriptional regulator of peripheral tissue antigens (PTAs) and microRNAs (miRNAs) in medullary thymic epithelial cells (mTECs). In this study, we tested the hypothesis that Aire also played a role as an upstream posttranscriptional controller in these cells and that variation in its expression might be associated with changes in the interactions between miRNAs and the mRNAs encoding PTAs. We demonstrated that downregulation of Aire in vivo in the thymuses of BALB/c mice imbalanced the large-scale expression of these two RNA species and consequently their interactions. The expression profiles of a large set of mTEC miRNAs and mRNAs isolated from the thymuses of mice subjected (or not) to small-interfering-induced Aire gene knockdown revealed that 87 miRNAs and 4,558 mRNAs were differentially expressed. The reconstruction of the miRNA-mRNA interaction networks demonstrated that interactions between these RNAs were under Aire influence and therefore changed when this gene was downregulated. Prior to Aire-knockdown, only members of the miR-let-7 family interacted with a set of PTA mRNAs. Under Aire-knockdown conditions, a larger set of miRNA families and their members established this type of interaction. Notably, no previously described Aire-dependent PTA interacted with the miRNAs, indicating that these PTAs were somehow refractory. The miRNA-mRNA interactions were validated by calculating the minimal free energy of the pairings between the miRNA seed regions and the mRNA 3' UTRs and within the cellular milieu using the luciferase reporter gene assay. These results suggest the existence of a link between transcriptional and posttranscriptional control because Aire downregulation alters the miRNA-mRNA network controlling PTAs in mTEC cells.

  20. Hardware/Software Data Acquisition System for Real Time Cell Temperature Monitoring in Air-Cooled Polymer Electrolyte Fuel Cells

    Directory of Open Access Journals (Sweden)

    Francisca Segura

    2017-07-01

    Full Text Available This work presents a hardware/software data acquisition system developed for monitoring the temperature in real time of the cells in Air-Cooled Polymer Electrolyte Fuel Cells (AC-PEFC. These fuel cells are of great interest because they can carry out, in a single operation, the processes of oxidation and refrigeration. This allows reduction of weight, volume, cost and complexity of the control system in the AC-PEFC. In this type of PEFC (and in general in any PEFC, the reliable monitoring of temperature along the entire surface of the stack is fundamental, since a suitable temperature and a regular distribution thereof, are key for a better performance of the stack and a longer lifetime under the best operating conditions. The developed data acquisition (DAQ system can perform non-intrusive temperature measurements of each individual cell of an AC-PEFC stack of any power (from watts to kilowatts. The stack power is related to the temperature gradient; i.e., a higher power corresponds to a higher stack surface, and consequently higher temperature difference between the coldest and the hottest point. The developed DAQ system has been implemented with the low-cost open-source platform Arduino, and it is completed with a modular virtual instrument that has been developed using NI LabVIEW. Temperature vs time evolution of all the cells of an AC-PEFC both together and individually can be registered and supervised. The paper explains comprehensively the developed DAQ system together with experimental results that demonstrate the suitability of the system.

  1. Hardware/Software Data Acquisition System for Real Time Cell Temperature Monitoring in Air-Cooled Polymer Electrolyte Fuel Cells.

    Science.gov (United States)

    Segura, Francisca; Bartolucci, Veronica; Andújar, José Manuel

    2017-07-09

    This work presents a hardware/software data acquisition system developed for monitoring the temperature in real time of the cells in Air-Cooled Polymer Electrolyte Fuel Cells (AC-PEFC). These fuel cells are of great interest because they can carry out, in a single operation, the processes of oxidation and refrigeration. This allows reduction of weight, volume, cost and complexity of the control system in the AC-PEFC. In this type of PEFC (and in general in any PEFC), the reliable monitoring of temperature along the entire surface of the stack is fundamental, since a suitable temperature and a regular distribution thereof, are key for a better performance of the stack and a longer lifetime under the best operating conditions. The developed data acquisition (DAQ) system can perform non-intrusive temperature measurements of each individual cell of an AC-PEFC stack of any power (from watts to kilowatts). The stack power is related to the temperature gradient; i.e., a higher power corresponds to a higher stack surface, and consequently higher temperature difference between the coldest and the hottest point. The developed DAQ system has been implemented with the low-cost open-source platform Arduino, and it is completed with a modular virtual instrument that has been developed using NI LabVIEW. Temperature vs time evolution of all the cells of an AC-PEFC both together and individually can be registered and supervised. The paper explains comprehensively the developed DAQ system together with experimental results that demonstrate the suitability of the system.

  2. A dose-controlled system for air-liquid interface cell exposure and application to zinc oxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Ferron George A

    2009-12-01

    Full Text Available Abstract Background Engineered nanoparticles are becoming increasingly ubiquitous and their toxicological effects on human health, as well as on the ecosystem, have become a concern. Since initial contact with nanoparticles occurs at the epithelium in the lungs (or skin, or eyes, in vitro cell studies with nanoparticles require dose-controlled systems for delivery of nanoparticles to epithelial cells cultured at the air-liquid interface. Results A novel air-liquid interface cell exposure system (ALICE for nanoparticles in liquids is presented and validated. The ALICE generates a dense cloud of droplets with a vibrating membrane nebulizer and utilizes combined cloud settling and single particle sedimentation for fast (~10 min; entire exposure, repeatable (2. The cell-specific deposition efficiency is currently limited to 0.072 (7.2% for two commercially available 6-er transwell plates, but a deposition efficiency of up to 0.57 (57% is possible for better cell coverage of the exposure chamber. Dose-response measurements with ZnO nanoparticles (0.3-8.5 μg/cm2 showed significant differences in mRNA expression of pro-inflammatory (IL-8 and oxidative stress (HO-1 markers when comparing submerged and air-liquid interface exposures. Both exposure methods showed no cellular response below 1 μg/cm2 ZnO, which indicates that ZnO nanoparticles are not toxic at occupationally allowed exposure levels. Conclusion The ALICE is a useful tool for dose-controlled nanoparticle (or solute exposure of cells at the air-liquid interface. Significant differences between cellular response after ZnO nanoparticle exposure under submerged and air-liquid interface conditions suggest that pharmaceutical and toxicological studies with inhaled (nano-particles should be performed under the more realistic air-liquid interface, rather than submerged cell conditions.

  3. Durability and regeneration of activated carbon air-cathodes in long-term operated microbial fuel cells

    Science.gov (United States)

    Zhang, Enren; Wang, Feng; Yu, Qingling; Scott, Keith; Wang, Xu; Diao, Guowang

    2017-08-01

    The performance of activated carbon catalyst in air-cathodes in microbial fuel cells was investigated over one year. A maximum power of 1722 mW m-2 was produced within the initial one-month microbial fuel cell operation. The air-cathodes produced a maximum power >1200 mW m-2 within six months, but gradually became a limiting factor for the power output in prolonged microbial fuel cell operation. The maximum power decreased by 55% when microbial fuel cells were operated over one year due to deterioration in activated carbon air-cathodes. While salt/biofilm removal from cathodes experiencing one-year operation increased a limiting performance enhancement in cathodes, a washing-drying-pressing procedure could restore the cathode performance to its original levels, although the performance restoration was temporary. Durable cathodes could be regenerated by re-pressing activated carbon catalyst, recovered from one year deteriorated air-cathodes, with new gas diffusion layer, resulting in ∼1800 mW m-2 of maximum power production. The present study indicated that activated carbon was an effective catalyst in microbial fuel cell cathodes, and could be recovered for reuse in long-term operated microbial fuel cells by simple methods.

  4. Inactivation of Escherichia coli Cells in Aqueous Solution by Atmospheric-Pressure N2, He, Air, and O2 Microplasmas.

    Science.gov (United States)

    Zhou, Renwu; Zhang, Xianhui; Bi, Zhenhua; Zong, Zichao; Niu, Jinhai; Song, Ying; Liu, Dongping; Yang, Size

    2015-08-01

    Atmospheric-pressure N2, He, air, and O2 microplasma arrays have been used to inactivate Escherichia coli cells suspended in aqueous solution. Measurements show that the efficiency of inactivation of E. coli cells is strongly dependent on the feed gases used, the plasma treatment time, and the discharge power. Compared to atmospheric-pressure N2 and He microplasma arrays, air and O2 microplasma arrays may be utilized to more efficiently kill E. coli cells in aqueous solution. The efficiencies of inactivation of E. coli cells in water can be well described by using the chemical reaction rate model, where reactive oxygen species play a crucial role in the inactivation process. Analysis indicates that plasma-generated reactive species can react with E. coli cells in water by direct or indirect interactions. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  5. A New Control and Design of PEM Fuel Cell System Powered Diffused Air Aeration System

    Directory of Open Access Journals (Sweden)

    Hassen T. Dorrah

    2012-06-01

    Full Text Available The goal of aquaculture ponds is to maximize production and profits while holding labor and management efforts to the minimum. Poor water quality in most ponds causes risk of fish kills, disease outbreaks which lead to minimization of pond production. Dissolved Oxygen (DO is considered to be among the most important water quality parameters in fish culture. Fish ponds in aquaculture farms are usually located in remote areas where grid lines are at far distance. Aeration of ponds is required to prevent mortality and to intensify production, especially when feeding is practical, and in warm regions. To increase pond production it is necessary to control dissolved oxygen. Aeration offers the most immediate and practical solution to water quality problems encountered at higher stocking and feeding rates. Many units of aeration system are electrical units so using a continuous, high reliability, affordable, and environmentally friendly power sources is necessary. Fuel cells have become one of the major areas of research in the academia and the industry. Aeration of water by using PEM fuel cell power is not only a new application of the renewable energy, but also, it provides an affordable method to promote biodiversity in stagnant ponds and lakes. This paper presents a new design and control of PEM fuel cell powered a diffused air aeration system for a shrimp farm in Mersa Matruh in Egypt. Also Artificial intelligence (AI control techniques are used to control the fuel cell output power by controlling its input gases flow rate. Moreover the mathematical modeling and simulation of PEM fuel cell is introduced. A comparative study is applied between the performance of fuzzy logic controller (FLC and neural network controller (NNC. The results show the effectiveness of NNC over FLC.

  6. Thermal Cyclability of Reactive Air Braze Seals in Anode Supported Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, John S.; Darsell, Jens T.; Coyle, Christopher A.; Birnbaum, Jerome C.; Weil, K. Scott

    2004-12-31

    The popularity of anode-supported solid oxide fuel cells (SOFC) has increased in tandem with the ability to fabricate thinner gas-tight yttrium-stabilized zirconia (YSZ) electrolyte layers, which can now be routinely produced on the order of 7 to 10 μm thick. While this has significantly improved power output and decreased the required fuel cell operating temperatures, the ability to reliably seal fuel cells remains a concern. The seals must be hermetic and be robust enough to retain their hermeticity even under the extreme operating conditions of SOFCs. Perhaps the largest contributor to stresses experienced by the seal is the fact that the SOFC is an assembly of many different materials with different thermal expansion properties. Although every effort is made to minimize thermal expansion mismatches across the seals, the stresses developed during thermal cycling still jeopardize seal integrity. Reactive air brazing (RAB), a method of joining that employs a metallic, and therefore non-brittle, seal material has been used to seal electrolyte/anode bilayers, such as those in anode-supported SOFCs, to Crofer-22 alloy. The results of rupture strength testing will be reported for as-brazed and thermally cycled samples and the effect of thermal cycling on the RAB seal microstructure will be shown

  7. ZnO nanorods/AZO photoanode for perovskite solar cells fabricated in ambient air

    Science.gov (United States)

    La Ferrara, Vera; De Maria, Antonella; Rametta, Gabriella; Della Noce, Marco; Vittoria Mercaldo, Lucia; Borriello, Carmela; Bruno, Annalisa; Delli Veneri, Paola

    2017-08-01

    ZnO nanorods are a good candidate for replacing standard photoanodes, such as TiO2, in perovskite solar cells and in principle superseding the high performances already obtained. This is possible because ZnO nanorods have a fast electron transport rate due to their large surface area. An array of ZnO nanorods is grown by chemical bath deposition starting from Al-doped ZnO (AZO) used both as a seed layer and as an efficient transparent anode in the visible spectral range. In particular, in this work we fabricate methylammonium lead iodide (CH3NH3PbI3) perovskite solar cells using glass/AZO/ZnO nanorods/perovskite/Spiro-OMeTAD/Au as the architecture. The growth of ZnO nanorods has been optimized by varying the precursor concentrations, growth time and solution temperature. All the fabrication process and photovoltaic characterizations have been carried out in ambient air and the devices have not been encapsulated. Power conversion efficiency as high as 7.0% has been obtained with a good stability over 20 d. This is the highest reported value to the best of our knowledge and it is a promising result for the development of perovskite solar cells based on ZnO nanorods and AZO.

  8. Improved air stability of perovskite solar cells via solution-processed metal oxide transport layers

    Science.gov (United States)

    You, Jingbi; Meng, Lei; Song, Tze-Bin; Guo, Tzung-Fang; Yang, Yang (Michael); Chang, Wei-Hsuan; Hong, Ziruo; Chen, Huajun; Zhou, Huanping; Chen, Qi; Liu, Yongsheng; De Marco, Nicholas; Yang, Yang

    2016-01-01

    Lead halide perovskite solar cells have recently attracted tremendous attention because of their excellent photovoltaic efficiencies. However, the poor stability of both the perovskite material and the charge transport layers has so far prevented the fabrication of devices that can withstand sustained operation under normal conditions. Here, we report a solution-processed lead halide perovskite solar cell that has p-type NiOx and n-type ZnO nanoparticles as hole and electron transport layers, respectively, and shows improved stability against water and oxygen degradation when compared with devices with organic charge transport layers. Our cells have a p-i-n structure (glass/indium tin oxide/NiOx/perovskite/ZnO/Al), in which the ZnO layer isolates the perovskite and Al layers, thus preventing degradation. After 60 days storage in air at room temperature, our all-metal-oxide devices retain about 90% of their original efficiency, unlike control devices made with organic transport layers, which undergo a complete degradation after just 5 days. The initial power conversion efficiency of our devices is 14.6 ± 1.5%, with an uncertified maximum value of 16.1%.

  9. NanoCapillary Network Proton Conducting Membranes for High Temperature Hydrogen/Air Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Pintauro, Peter [Vanderbilt Univ., Nashville, TN (United States)

    2012-07-09

    The objective of this proposal is to fabricate and characterize a new class of NanoCapillary Network (NCN) proton conducting membranes for hydrogen/air fuel cells that operate under high temperature, low humidity conditions. The membranes will be intelligently designed, where a high density interconnecting 3-D network of nm-diameter electrospun proton conducting polymer fibers is embedded in an inert (uncharged) water/gas impermeable polymer matrix. The high density of fibers in the resulting mat and the high ion-exchange capacity of the fiber polymer will ensure high proton conductivity. To further enhance water retention, molecular silica will be added to the sulfonated polymer fibers. The uncharged matrix material will control water swelling of the high ion-exchange capacity proton conducting polymer fibers and will impart toughness to the final nanocapillary composite membrane. Thus, unlike other fuel cell membranes, the role of the polymer support matrix will be decoupled from that of the proton-conducting channels. The expected final outcome of this 5-year project is the fabrication of fuel cell membranes with properties that exceed the DOE’s technical targets, in particular a proton conductivity of 0.1 S/cm at a temperature less than or equal to120°C and 25-50% relative humidity.

  10. Acoustical transmission-line model of the middle-ear cavities and mastoid air cells.

    Science.gov (United States)

    Keefe, Douglas H

    2015-04-01

    An acoustical transmission line model of the middle-ear cavities and mastoid air cell system (MACS) was constructed for the adult human middle ear with normal function. The air-filled cavities comprised the tympanic cavity, aditus, antrum, and MACS. A binary symmetrical airway branching model of the MACS was constructed using an optimization procedure to match the average total volume and surface area of human temporal bones. The acoustical input impedance of the MACS was calculated using a recursive procedure, and used to predict the input impedance of the middle-ear cavities at the location of the tympanic membrane. The model also calculated the ratio of the acoustical pressure in the antrum to the pressure in the middle-ear cavities at the location of the tympanic membrane. The predicted responses were sensitive to the magnitude of the viscothermal losses within the MACS. These predicted input impedance and pressure ratio functions explained the presence of multiple resonances reported in published data, which were not explained by existing MACS models.

  11. Copper current collectors reduce long-term fouling of air cathodes in microbial fuel cells

    KAUST Repository

    Myung, Jaewook

    2018-02-05

    Long-term operation of wastewater-fed, microbial fuel cells (MFCs) with cathodes made of activated carbon and stainless steel (SS) current collectors can result in decreased performance due to cathode fouling. Copper has good antimicrobial properties, and it is more electrically conductive than SS. To demonstrate that a copper current collector could produce a more fouling resistant cathode, MFCs with air cathodes using either SS or copper current collectors were operated using domestic wastewater for 27 weeks. The reduction in biofouling over time was shown by less biofilm formation on the copper cathode surface compared to SS cathodes, due to the antimicrobial properties of copper. Maximum power densities from 17–27 weeks were 440 ± 38 mW/m2 using copper and 370 ± 21 mW/m2 using SS cathodes. The main difference in the microbial community was a nitrifying community on the SS cathodes, which was not present on the copper cathodes.

  12. Cleaning the air and improving health with hydrogen fuel-cell vehicles.

    Science.gov (United States)

    Jacobson, M Z; Colella, W G; Golden, D M

    2005-06-24

    Converting all U.S. onroad vehicles to hydrogen fuel-cell vehicles (HFCVs) may improve air quality, health, and climate significantly, whether the hydrogen is produced by steam reforming of natural gas, wind electrolysis, or coal gasification. Most benefits would result from eliminating current vehicle exhaust. Wind and natural gas HFCVs offer the greatest potential health benefits and could save 3700 to 6400 U.S. lives annually. Wind HFCVs should benefit climate most. An all-HFCV fleet would hardly affect tropospheric water vapor concentrations. Conversion to coal HFCVs may improve health but would damage climate more than fossil/electric hybrids. The real cost of hydrogen from wind electrolysis may be below that of U.S. gasoline.

  13. Controllable Impregnation Via Inkjet Printing for the Fabrication of Solid Oxide Cell Air Electrodes

    KAUST Repository

    Da'as, E. H.

    2013-10-07

    The impregnation method has been considered as one of the most successful techniques for the fabrication of highly efficient electrodes for solid oxide fuel and electrolysis cells (SOCs) at the lab scale. However, because the impregnation is usually performed manually, its irreproducibility remains a major problem that can be solved by using controllable techniques, such as inkjet printing. In this paper, lanthanum strontium manganite (LSM)/yttria stabilized zirconia (YSZ) air electrodes were prepared by infiltrating YSZ porous bodies with LSM precursor solution using inkjet printing, followed by annealing at 800°C for 2 hours. XRD analysis confirmed the formation of the LSM phase, which was in the form of nanoparticles with size in the 50-70 nm range on the YSZ walls, as revealed by FEG-SEM observations. The effect of printing parameters on the distribution of the impregnated phase was investigated and discussed.

  14. Effect of Sodium Dodecyl Sulfate (SDS) and Tween 80 on Cell Viability in an Air-Cathode Microbial Fuel Cell

    KAUST Repository

    Fregoso, Luisa

    2011-07-01

    Microbial fuel cells (MFCs) generate current via electrochemical reactions produced by bacteria attached to the anode that oxidize organic matter. Due to their high volume use in household products, some concentration of surfactant will reach wastewater treatment plants. The average surfactant concentration in wastewater ranges from 10 to 20 mg L-1, and up to 300 mg L-1, for domestic and industrial wastewaters, respectively. This study aimed to demonstrate the feasibility of enhancing power production by adding Tween 80 and SDS surfactants to air-cathode MFCs, and their effect in cell viability at the anodic biofilm. In order to analyze the effect of anionic and nonionic surfactants in MFCs performance, eight MFCs were spiked with two types of surfactants, the anionic surfactant sodium dodecyl sulfate (SDS) and the nonionic surfactant Tween® 80 at two different concentrations 10 and 100 mg L-1. Cell viability at the anodic biofilms was examined using the LIVE/DEAD BacLight viability assay and images were visualized with a confocal laser scanning microscope. The electrochemical results demonstrate that, for an air-cathode MFC operating on 1 g L-1 acetate in a fed-batch mode, reactors where SDS was added show a lower overall performance, maximum PD of 544 mW m-2, CE of 12.3%, Rint of 322 Ω (10 mg L-1) and maximum PD of 265 mW m-2, CE of 9.4%, Rint of 758 Ω (100 mg L-1). Reactors where Tween 80 was added show quite stable performance, maximum PD of 623 mW m-2, CE of 15.4%, Rint of 216 Ω (10 mg L-1) and maximum PD of 591 mW m-2, CE of 10.8%, Rint of 279 Ω (100 mg L-1), compared with reactors operating at only acetate as a substrate, maximum PD of 574 mW m-2. Confocal microscopy images confirm this observation and biofilm viability appeared severely compromised in SDS reactors, especially at high concentrations. This study has opened up a whole new research area in determining which types of surfactants are toxic to the anodic biofilm and to further investigate the

  15. TLR-2 is involved in airway epithelial cell response to air pollution particles

    International Nuclear Information System (INIS)

    Becker, Susanne; Dailey, Lisa; Soukup, Joleen M.; Silbajoris, Robert; Devlin, Robert B.

    2005-01-01

    Primary cultures of normal human airway epithelial cells (NHBE) respond to ambient air pollution particulate matter (PM) by increased production of the cytokine IL-8, and the induction of several oxidant stress response genes. Components of ambient air PM responsible for stimulating epithelial cells have not been conclusively identified, although metal contaminants, benzo[a]pyrene and biological matter have been implicated. Stimulation of IL-8 release from NHBE with coarse (PM 2.5-10 ), fine (PM 2.5 ), and UF particle fractions has shown that the coarse particle fraction has the greatest effect on the epithelial cells as well as alveolar macrophages (AM). Since this fraction concentrates fugitive dusts and particle-associated microbial matter, it was hypothesized that NHBE may recognize PM through microbial pattern recognition receptors TLR2 and TLR4, as has been previously shown with AM. NHBE were shown to release IL-8 when exposed to a Gram-positive environmental isolate of Staphylococcus lentus, and lower levels when exposed to Gram-negative Pseudomonas spp. Comparison of TLR2 and TLR4 mRNA expression in NHBE and AM showed that NHBE express similar levels of TLR2 mRNA as the AM, but expressed very low levels of TLR4. When NHBE were stimulated with PM 2.5-10 , PM 2.5 , and UF PM, in the presence or absence of inhibitors of TLR2 and TLR4 activation, a blocking antibody to TLR2 inhibited production of IL-8, while TLR4 antagonist E5531 or the LPS inhibitor Polymixin B had no effect. Furthermore, effects on expression of TLR2 and TLR4 mRNA, as well as the stress protein HSP70 was assessed in NHBE exposed to PM. TLR4 expression was increased in these cells while TLR2 mRNA levels were unchanged. Hsp70 was increased by PM 2.5-10 > PM 2.5 > UF PM suggesting the possibility of indirect activation of TLR pathway by this endogenous TLR2/4 agonist

  16. Effects of atmospheric air plasma treatment of graphite and carbon felt electrodes on the anodic current from Shewanella attached cells.

    Science.gov (United States)

    Epifanio, Monica; Inguva, Saikumar; Kitching, Michael; Mosnier, Jean-Paul; Marsili, Enrico

    2015-12-01

    The attachment of electrochemically active microorganisms (EAM) on an electrode is determined by both the chemistry and topography of the electrode surface. Pre-treatment of the electrode surface by atmospheric air plasma introduces hydrophilic functional groups, thereby increasing cell attachment and electroactivity in short-term experiments. In this study, we use graphite and carbon felt electrodes to grow the model EAM Shewanella loihica PV-4 at oxidative potential (0.2 V vs. Ag/AgCl). Cell attachment and electroactivity are measured through electrodynamic methods. Atmospheric air plasma pre-treatment increases cell attachment and current output at graphite electrodes by 25%, while it improves the electroactivity of the carbon felt electrodes by 450%. Air plasma pre-treatment decreased the coulombic efficiency on both carbon felt and graphite electrodes by 60% and 80%, respectively. Microbially produced flavins adsorb preferentially at the graphite electrode, and air plasma pre-treatment results in lower flavin adsorption at both graphite and carbon felt electrodes. Results show that air plasma pre-treatment is a feasible option to increase current output in bioelectrochemical systems. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Activated carbon derived from chitosan as air cathode catalyst for high performance in microbial fuel cells

    Science.gov (United States)

    Liu, Yi; Zhao, Yong; Li, Kexun; Wang, Zhong; Tian, Pei; Liu, Di; Yang, Tingting; Wang, Junjie

    2018-02-01

    Chitosan with rich of nitrogen is used as carbon precursor to synthesis activated carbon through directly heating method in this study. The obtained carbon is activated by different amount of KOH at different temperatures, and then prepared as air cathodes for microbial fuel cells. Carbon sample treated with double amount of KOH at 850 °C exhibits maximum power density (1435 ± 46 mW m-2), 1.01 times improved, which ascribes to the highest total surface area, moderate micropore and mesoporous structure and the introduction of nitrogen. The electrochemical impedance spectroscopy and powder resistivity state that carbon treated with double amount of KOH at 850 °C possesses lower resistance. The other electrochemical measurements demonstrate that the best kinetic activity make the above treated sample to show the best oxygen reduction reaction activity. Besides, the degree of graphitization of samples increases with the activated temperature increasing, which is tested by Raman. According to elemental analysis and X-ray photoelectron spectroscopy, all chitosan samples are nitrogen-doped carbon, and high content nitrogen (pyridinic-N) improves the electrochemical activity of carbon treated with KOH at 850 °C. Thus, carbon materials derived from chitosan would be an optimized catalyst for oxygen reduction reaction in microbial fuel cell.

  18. Research and Development of Zinc Air Fuel Cell To Achieve Commercialization Final Report CRADA No. TC-1544-98

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, J. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Haley, H. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-28

    The specific goal of this project was to advance the development of the zinc air fuel cell (ZAFC) towards commercial readiness in different mobile applications, including motor bikes, passenger cars, vans, buses and off-road vehicles (golf carts, factory equipment), and different stationary applications including generator sets, uninterruptible power systems and electric utility loading leveling and distributive power.

  19. Effect of eggshell temperature and a hole in the air cell on the perinatal development and physiology of layer hatchlings

    NARCIS (Netherlands)

    Molenaar, R.; Vries, de S.; Anker, van den I.; Meijerhof, R.; Kemp, B.; Brand, van den H.

    2010-01-01

    To investigate the effect of incubation conditions on layer hatchlings, an experiment was performed in which layer eggs were incubated at a normal (37.8°C) or high (38.9°C) eggshell temperature (EST) and a hole was punctured in the air cell of half of the eggs in both EST treatments from d 14 of

  20. Air-cathode structure optimization in separator-coupled microbial fuel cells

    KAUST Repository

    Zhang, Xiaoyuan

    2011-12-01

    Microbial fuel cells (MFC) with 30% wet-proofed air cathodes have previously been optimized to have 4 diffusion layers (DLs) in order to limit oxygen transfer into the anode chamber and optimize performance. Newer MFC designs that allow close electrode spacing have a separator that can also reduce oxygen transfer into the anode chamber, and there are many types of carbon wet-proofed materials available. Additional analysis of conditions that optimize performance is therefore needed for separator-coupled MFCs in terms of the number of DLs and the percent of wet proofing used for the cathode. The number of DLs on a 50% wet-proofed carbon cloth cathode significantly affected MFC performance, with the maximum power density decreasing from 1427 to 855mW/m 2 for 1-4 DLs. A commonly used cathode (30% wet-proofed, 4 DLs) produced a maximum power density (988mW/m 2) that was 31% less than that produced by the 50% wet-proofed cathode (1 DL). It was shown that the cathode performance with different materials and numbers of DLs was directly related to conditions that increased oxygen transfer. The coulombic efficiency (CE) was more affected by the current density than the oxygen transfer coefficient for the cathode. MFCs with the 50% wet-proofed cathode (2 DLs) had a CE of >84% (6.8A/m 2), which was substantially larger than that previously obtained using carbon cloth air-cathodes lacking separators. These results demonstrate that MFCs constructed with separators should have the minimum number of DLs that prevent water leakage and maximize oxygen transfer to the cathode. © 2011 Elsevier B.V.

  1. Diffusion layer characteristics for increasing the performance of activated carbon air cathodes in microbial fuel cells

    KAUST Repository

    Zhang, Xiaoyuan

    2016-01-01

    The characteristics of several different types of diffusion layers were systematically examined to improve the performance of activated carbon air cathodes used in microbial fuel cells (MFCs). A diffusion layer of carbon black and polytetrafluoroethylene (CB + PTFE) that was pressed onto a stainless steel mesh current collector achieved the highest cathode performance. This cathode also had a high oxygen mass transfer coefficient and high water pressure tolerance (>2 m), and it had the highest current densities in abiotic chronoamperometry tests compared to cathodes with other diffusion layers. In MFC tests, this cathode also produced maximum power densities (1610 ± 90 mW m−2) that were greater than those of cathodes with other diffusion layers, by 19% compared to Gore-Tex (1350 ± 20 mW m−2), 22% for a cloth wipe with PDMS (1320 ± 70 mW m−2), 45% with plain PTFE (1110 ± 20 mW m−2), and 19% higher than those of cathodes made with a Pt catalyst and a PTFE diffusion layer (1350 ± 50 mW m−2). The highly porous diffusion layer structure of the CB + PTFE had a relatively high oxygen mass transfer coefficient (1.07 × 10−3 cm s−1) which enhanced oxygen transport to the catalyst. The addition of CB enhanced cathode performance by increasing the conductivity of the diffusion layer. Oxygen mass transfer coefficient, water pressure tolerance, and the addition of conductive particles were therefore critical features for achieving higher performance AC air cathodes.

  2. Aire Inhibits the Generation of a Perinatal Population of Interleukin-17A-Producing γδ T Cells to Promote Immunologic Tolerance.

    Science.gov (United States)

    Fujikado, Noriyuki; Mann, Alexander O; Bansal, Kushagra; Romito, Kimberly R; Ferre, Elise M N; Rosenzweig, Sergio D; Lionakis, Michail S; Benoist, Christophe; Mathis, Diane

    2016-11-15

    Aire's primary mechanism of action is to regulate transcription of a battery of genes in medullary thymic epithelial cells (mTECs) and, consequently, negative selection of effector T cells and positive selection of regulatory T cells. We found that Aire-deficient mice had expanded thymic and peripheral populations of perinatally generated IL-17A + Vγ6 + Vδ1 + T cells, considered to be "early responders" to tissue stress and drivers of inflammatory reactions. Aire-dependent control of Il7 expression in mTECs regulated the size of thymic IL-17A + Vγ6 + Vδ1 + compartments. In mice lacking Aire and γδ T cells, certain tissues typically targeted in the "Aire-less" disease, notably the retina, were only minimally infiltrated. IL-17A + Vγ6 + Vδ1 + cells were present in the retina of wild-type mice and expanded very early in Aire-deficient mice. A putatively parallel population of IL-17A + Vγ9 + Vδ2 + T cells was increased in humans lacking Aire. Thus, Aire exerts multi-faceted autoimmune control that extends to a population of innate-like T cells. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Full cell simulation and the evaluation of the buffer system on air-cathode microbial fuel cell

    Science.gov (United States)

    Ou, Shiqi; Kashima, Hiroyuki; Aaron, Douglas S.; Regan, John M.; Mench, Matthew M.

    2017-04-01

    This paper presents a computational model of a single chamber, air-cathode MFC. The model considers losses due to mass transport, as well as biological and electrochemical reactions, in both the anode and cathode half-cells. Computational fluid dynamics and Monod-Nernst analysis are incorporated into the reactions for the anode biofilm and cathode Pt catalyst and biofilm. The integrated model provides a macro-perspective of the interrelation between the anode and cathode during power production, while incorporating microscale contributions of mass transport within the anode and cathode layers. Model considerations include the effects of pH (H+/OH- transport) and electric field-driven migration on concentration overpotential, effects of various buffers and various amounts of buffer on the pH in the whole reactor, and overall impacts on the power output of the MFC. The simulation results fit the experimental polarization and power density curves well. Further, this model provides insight regarding mass transport at varying current density regimes and quantitative delineation of overpotentials at the anode and cathode. Overall, this comprehensive simulation is designed to accurately predict MFC performance based on fundamental fluid and kinetic relations and guide optimization of the MFC system.

  4. An air-breathing micro direct methanol fuel cell stack employing a single shared anode using silicon microfabrication technologies

    Science.gov (United States)

    Wang, Xiaohong; Zhou, Yan'an; Zhang, Qian; Zhu, Yiming; Liu, Litian

    2009-09-01

    This paper presents a silicon-based air-breathing micro direct methanol fuel cell (μDMFC) stack with a shared anode plate and two air-breathing cathode plates. Three kinds of anode plates featured by different methanol transport methods are designed and simulated. Microfabrication technologies, including double-side lithography and bulk-micromachining, are used to fabricate both anode and cathode silicon plates on the same wafer simultaneously. Three μDMFC stacks with different kinds of anodes are assembled, and characterized with a single cell together. Simulation and experimental results show that the μDMFC stack with fuel transport in a shared model has the best performance, and this stack achieves a power of 2.52 mW which is almost double that of a single cell of 1.28 mW.

  5. Retaining the 3D framework of zinc sponge anodes upon deep discharge in Zn-air cells.

    Science.gov (United States)

    Parker, Joseph F; Nelson, Eric S; Wattendorf, Matthew D; Chervin, Christopher N; Long, Jeffrey W; Rolison, Debra R

    2014-11-26

    We fabricate three-dimensional zinc electrodes from emulsion-cast sponges of Zn powder that are thermally treated to produce rugged monoliths. This highly conductive, 3D-wired aperiodic scaffold achieves 740 mA h gZn(-1) when discharged in primary Zn-air cells (>90% of theoretical Zn capacity). We use scanning electron microscopy and X-ray diffraction to monitor the microstructural evolution of a series of Zn sponges when oxidized in Zn-air cells to specific depths-of-discharge (20, 40, 60, 80% DOD) at a technologically relevant rate (C/40; 4-6 mA cm(-2)). The Zn sponges maintain their 3D-monolithic form factor at all DOD. The cell resistance remains low under all test conditions, indicating that an inner core of metallic Zn persists that 3D-electrically wires the electrode, even to deep DOD.

  6. Perspective: Maintaining surface-phase purity is key to efficient open air fabricated cuprous oxide solar cells

    International Nuclear Information System (INIS)

    Hoye, Robert L. Z.; Ievskaya, Yulia; MacManus-Driscoll, Judith L.; Brandt, Riley E.; Buonassisi, Tonio; Heffernan, Shane; Musselman, Kevin P.

    2015-01-01

    Electrochemically deposited Cu 2 O solar cells are receiving growing attention owing to a recent doubling in efficiency. This was enabled by the controlled chemical environment used in depositing doped ZnO layers by atomic layer deposition, which is not well suited to large-scale industrial production. While open air fabrication with atmospheric pressure spatial atomic layer deposition overcomes this limitation, we find that this approach is limited by an inability to remove the detrimental CuO layer that forms on the Cu 2 O surface. Herein, we propose strategies for achieving efficiencies in atmospherically processed cells that are equivalent to the high values achieved in vacuum processed cells

  7. Electricity generation from fermented primary sludge using single-chamber air-cathode microbial fuel cells

    KAUST Repository

    Yang, Fei

    2013-01-01

    Single-chamber air-cathode microbial fuel cells (MFCs) were used to generate electricity from fermented primary sludge. Fermentation (30°C, 9days) decreased total suspended solids (26.1-16.5g/L), volatile suspended solids (24.1-15.3g/L) and pH (5.7-4.5), and increased conductivity (2.4-4.7mS/cm), soluble COD (2.66-15.5g/L), and volatile fatty acids (1.9-10.1g/L). To lower the COD and increase pH, fermentation supernatant was diluted with primary effluent before being used in the MFCs. The maximum power density was 0.32±0.01W/m2, compared to 0.24±0.03W/m2 with only primary effluent. Power densities were higher with phosphate buffer added to the supernatant (1.03±0.06W/m2) or the solution (0.87±0.05W/m2). Coulombic efficiencies ranged from 18% to 57%, and sCOD removals from 84% to 94%. These results demonstrated that sludge can effectively be used for power generation when fermented and then diluted with only primary effluent. © 2012 Elsevier Ltd.

  8. Further study of the intrinsic safety of internally shorted lithium and lithium-ion cells within methane-air.

    Science.gov (United States)

    Dubaniewicz, Thomas H; DuCarme, Joseph P

    2014-11-01

    National Institute for Occupational Safety and Health (NIOSH) researchers continue to study the potential for lithium and lithium-ion battery thermal runaway from an internal short circuit in equipment for use in underground coal mines. Researchers conducted cell crush tests using a plastic wedge within a 20-L explosion-containment chamber filled with 6.5% CH 4 -air to simulate the mining hazard. The present work extends earlier findings to include a study of LiFePO 4 cells crushed while under charge, prismatic form factor LiCoO 2 cells, primary spiral-wound constructed LiMnO 2 cells, and crush speed influence on thermal runaway susceptibility. The plastic wedge crush was a more severe test than the flat plate crush with a prismatic format cell. Test results indicate that prismatic Saft MP 174565 LiCoO 2 and primary spiral-wound Saft FRIWO M52EX LiMnO 2 cells pose a CH 4 -air ignition hazard from internal short circuit. Under specified test conditions, A123 systems ANR26650M1A LiFePO 4 cylindrical cells produced no chamber ignitions while under a charge of up to 5 A. Common spiral-wound cell separators are too thin to meet intrinsic safety standards provisions for distance through solid insulation, suggesting that a hard internal short circuit within these cells should be considered for intrinsic safety evaluation purposes, even as a non-countable fault. Observed flames from a LiMnO 2 spiral-wound cell after a chamber ignition within an inert atmosphere indicate a sustained exothermic reaction within the cell. The influence of crush speed on ignitions under specified test conditions was not statistically significant.

  9. Flameballs, cells and cusps in ultra-lean hythane-air mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Shoshin, Y.; Bastiaans, R.; De Goey, P.; Hernandez Perez, F.; Van Oijen, J. [Eindhoven University of Technology TUE, Eindhoven (Netherlands)

    2012-06-07

    There is a growing interest in using hydrogen-containing gas fuel blends for practical combustion applications. The addition of hydrogen to natural gas (the main constituent of which is methane) allows for leaner operation of premixed combustion at lower temperatures, which leads to reduced NOx, CO, and CO2 emissions, and to higher efficiencies of engines and turbines. While hydrogen is often seen as the main energy carrier of the future, the transition to a global hydrogen economy may take decades. In this period, mixtures of hydrogen with natural gas and other hydrogen-containing blends, such as syngas or biofuels, are expected to become dominant fuels. Hydrogen-containing blends exhibit a very specific combustion behavior. Due to the high diffusivity of hydrogen, flames are strongly affected by so-called preferential diffusion effects. Even in the absence of turbulence, these effects lead to flame instability and to the formation of characteristic non-uniform cellular structures. In turbulent flames, the local flame structure still exhibits characteristic features of laminar cellular flames. Non-uniform reaction layers strongly affect the total rate of pollutant generation, overall combustion rate, and the lean limit of operation of combustion devices. Test simulations show that ignoring preferential diffusion effects in hydrogen-containing mixtures may lead to a more than twofold underestimation of the combustion rate. The goal of the proposed research is to acquire deep knowledge on the mentioned effects. To meet this goal a detailed experimental study using (ultra) lean two-dimensional laminar stationary flames of hydrogen-methane air mixtures will be carried out. The experiments will be setup to model all key structural elements of cellular flames: (1) Flame cells; (2) Flame cusps separating the cells; (3) Flame balls (in ultra-lean mixtures). To model flame cusps a flame formed at the tip of a laminar 2-D Bunsen flame will be used, for the flame balls and

  10. DNA damage in buccal mucosa cells of pre-school children exposed to high levels of urban air pollutants.

    Directory of Open Access Journals (Sweden)

    Elisabetta Ceretti

    Full Text Available Air pollution has been recognized as a human carcinogen. Children living in urban areas are a high-risk group, because genetic damage occurring early in life is considered able to increase the risk of carcinogenesis in adulthood. This study aimed to investigate micronuclei (MN frequency, as a biomarker of DNA damage, in exfoliated buccal cells of pre-school children living in a town with high levels of air pollution. A sample of healthy 3-6-year-old children living in Brescia, Northern Italy, was investigated. A sample of the children's buccal mucosa cells was collected during the winter months in 2012 and 2013. DNA damage was investigated using the MN test. Children's exposure to urban air pollution was evaluated by means of a questionnaire filled in by their parents that included items on various possible sources of indoor and outdoor pollution, and the concentration of fine particulate matter (PM10, PM2.5 and NO2 in the 1-3 weeks preceding biological sample collection. 181 children (mean age ± SD: 4.3 ± 0.9 years were investigated. The mean ± SD MN frequency was 0.29 ± 0.13%. A weak, though statistically significant, association of MN with concentration of air pollutants (PM10, PM2.5 and NO2 was found, whereas no association was apparent between MN frequency and the indoor and outdoor exposure variables investigated via the questionnaire. This study showed a high MN frequency in children living in a town with heavy air pollution in winter, higher than usually found among children living in areas with low or medium-high levels of air pollution.

  11. Numerical investigation of interfacial mass transport resistance and two-phase flow in PEM fuel cell air channels

    Science.gov (United States)

    Koz, Mustafa

    Proton exchange membrane fuel cells (PEMFCs) are efficient and environmentally friendly electrochemical engines. The performance of a PEMFC is adversely affected by oxygen (O2) concentration loss from the air flow channel to the cathode catalyst layer (CL). Oxygen transport resistance at the gas diffusion layer (GDL) and air channel interface is a non-negligible component of the O2 concentration loss. Simplified PEMFC performance models in the available literature incorporate the O2 resistance at the GDL-channel interface as an input parameter. However, this parameter has been taken as a constant so far in the available literature and does not reflect variable PEMFC operating conditions and the effect of two-phase flow in the channels. This study numerically calculates the O2 transport resistance at the GDL-air channel interface and expresses this resistance through the non-dimensional Sherwood number (Sh). Local Sh is investigated in an air channel with multiple droplets and films inside. These water features are represented as solid obstructions and only air flow is simulated. Local variations of Sh in the flow direction are obtained as a function of superficial air velocity, water feature size, and uniform spacing between water features. These variations are expressed with mathematical expressions for the PEMFC performance models to utilize and save computational resources. The resulting mathematical correlations for Sh can be utilized in PEMFC performance models. These models can predict cell performance more accurately with the help of the results of this work. Moreover, PEMFC performance models do not need to use a look-up table since the results were expressed through correlations. Performance models can be kept simplified although their predictions will become more realistic. Since two-phase flow in channels is experienced mostly at lower temperatures, performance optimization at low temperatures can be done easier.

  12. The impacts of replacing air bubbles with microspheres for the clarification of algae from low cell-density culture.

    Science.gov (United States)

    Ometto, Francesco; Pozza, Carlo; Whitton, Rachel; Smyth, Beatrice; Gonzalez Torres, Andrea; Henderson, Rita K; Jarvis, Peter; Jefferson, Bruce; Villa, Raffaella

    2014-04-15

    Dissolved Air Flotation (DAF) is a well-known coagulation-flotation system applied at large scale for microalgae harvesting. Compared to conventional harvesting technologies DAF allows high cell recovery at lower energy demand. By replacing microbubbles with microspheres, the innovative Ballasted Dissolved Air Flotation (BDAF) technique has been reported to achieve the same algae cell removal efficiency, while saving up to 80% of the energy required for the conventional DAF unit. Using three different algae cultures (Scenedesmus obliquus, Chlorella vulgaris and Arthrospira maxima), the present work investigated the practical, economic and environmental advantages of the BDAF system compared to the DAF system. 99% cells separation was achieved with both systems, nevertheless, the BDAF technology allowed up to 95% coagulant reduction depending on the algae species and the pH conditions adopted. In terms of floc structure and strength, the inclusion of microspheres in the algae floc generated a looser aggregate, showing a more compact structure within single cell alga, than large and filamentous cells. Overall, BDAF appeared to be a more reliable and sustainable harvesting system than DAF, as it allowed equal cells recovery reducing energy inputs, coagulant demand and carbon emissions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Electronic modification of Pt via Ti and Se as tolerant cathodes in air-breathing methanol microfluidic fuel cells.

    Science.gov (United States)

    Ma, Jiwei; Habrioux, Aurélien; Morais, Cláudia; Alonso-Vante, Nicolas

    2014-07-21

    We reported herein on the use of tolerant cathode catalysts such as carbon supported Pt(x)Ti(y) and/or Pt(x)Se(y) nanomaterials in an air-breathing methanol microfluidic fuel cell. In order to show the improvement of mixed-reactant fuel cell (MRFC) performances obtained with the developed tolerant catalysts, a classical Pt/C nanomaterial was used for comparison. Using 5 M methanol concentration in a situation where the fuel crossover is 100% (MRFC-mixed reactant fuel cell application), the maximum power density of the fuel cell with a Pt/C cathodic catalyst decreased by 80% in comparison with what is observed in the laminar flow fuel cell (LFFC) configuration. With Pt(x)Ti(y)/C and Pt(x)Se(y)/C cathode nanomaterials, the performance loss was only 55% and 20%, respectively. The evaluation of the tolerant cathode catalysts in an air-breathing microfluidic fuel cell suggests the development of a novel nanometric system that will not be size restricted. These interesting results are the consequence of the high methanol tolerance of these advanced electrocatalysts via surface electronic modification of Pt. Herein we used X-ray photoelectron and in situ FTIR spectroscopies to investigate the origin of the high methanol tolerance on modified Pt catalysts.

  14. Investigation of the quality of stored red blood cells after simulated air drop in the maritime environment.

    Science.gov (United States)

    Meli, Athinoula; Hancock, Vicky; Doughty, Heidi; Smedley, Steve; Cardigan, Rebecca; Wiltshire, Michael

    2018-02-01

    Maritime medical capability may be compromised by blood resupply. Air-dropped red blood cells (RBCs) is a possible mitigation factor. This study set out to evaluate RBC storage variables after a simulated parachute air drop into the sea, as limited data exist. The air load construction for the air drop of blood was subject to static drop assessment to simulate a worst-case parachute drop scenario. One control and two test Golden Hour shipping containers were each packaged with 10 RBC units. The control box was not dropped; Test Boxes 1 and 2 were further reinforced with waterproof boxes and underwent a simulated air drop on Day 7 or Day 8 postdonation, respectively. One day after the drop and once a week thereafter until Day 43 of storage, RBCs from each box were sampled and tested for full blood counts, hemolysis, adenosine triphosphate, 2,3-diphosphoglycerate, pH, extracellular potassium, glucose, lactate, deformability, and RBC microvesicles. The packaging configuration completed the air drop with no water ingress or physical damage. All units met UK specifications for volume, hemoglobin, and hemolysis. There were no significant differences for any of the variables studied between RBCs in the control box compared to RBCs in Test Boxes 1 and 2 combined over storage. The test proved that the packaging solution and the impact of a maritime air drop as performed in this study, on Day 7 or Day 8 postdonation, did not affect the in vitro quality of RBCs in SAGM over storage for 35 days. © 2017 AABB.

  15. Conceptual Design Tool for Fuel-Cell Powered Micro Air Vehicles

    Science.gov (United States)

    2010-03-01

    fsID=10469&page=1, accessed 11 Jan 10, Nov 09. 39 Stewart, K., Wagener , J., Abate, G., and Salichon, M., ―Design of the Air Force Research... Wagener , J., Czabaranek, J., and Abate, G., ―Development and Initial Flight Tests of a Single-Jointed Articulated-Wing Micro Air Vehicle,‖ AIAA 2008-6708

  16. Cold atmospheric-pressure air plasma treatment of C6 glioma cells: effects of reactive oxygen species in the medium produced by the plasma on cell death

    Science.gov (United States)

    Wang, Yuyang; Cheng, Cheng; Gao, Peng; Li, Shaopeng; Shen, Jie; Lan, Yan; Yu, Yongqiang; Chu, Paul K.

    2017-02-01

    An atmospheric-pressure air plasma is employed to treat C6 glioma cells in vitro. To elucidate on the mechanism causing cell death and role of reactive species (RS) in the medium produced by the plasma, the concentration of the long-lived RS such as hydrogen peroxide, nitrate, and ozone in the plasma-treated liquid (phosphate-buffered saline solution) is measured. When vitamin C is added to the medium as a ROS quencher, the viability of C6 glioma cells after the plasma treatment is different from that without vitamin C. The results demonstrate that reactive oxygen species (ROS) such as H2O2, and O3 constitute the main factors for inactivation of C6 glioma cells and the reactive nitrogen species (RNS) may only play an auxiliary role in cell death.

  17. Effect of binders on natural graphite powder-based gas diffusion electrode for Mg-air cell

    Science.gov (United States)

    Arinton, Ghenadi; Rianto, Anton; Faizal, Ferry; Hidayat, Darmawan; Hidayat, Sahrul; Panatarani, Camellia; Joni, I. Made

    2016-03-01

    This paper mainly discussed the electrical performance of gas diffusion electrode of Mg-Air Cell. The gas diffusion electrodes (GDE) use a natural graphite powder as catalyst material. The effect of additional binders to the GDE have been investigated to improve electrode performances. Several types of GDE have been developed using binder materials such as epoxy resin, natural clay, carboxymethyl cellulose (CMC) and urea-formaldehyde (UF). By using discharge performance measurement, the characteristics of the as-prepared GDEs are reported.

  18. Morphometric changes of corneal endothelial cells following intracameral air for micro perforation of the Descemet Membrane during big-bubble deep anterior lamellar keratoplasty

    Directory of Open Access Journals (Sweden)

    Ashbala Khattak

    2016-04-01

    Conclusion: The presence of air inside the anterior chamber for a short term may not cause further endothelial cell loss and can be safely performed to prevent postoperative Descemet Membrane detachment in case of micro perforations.

  19. Inhibition of microbial growth on air cathodes of single chamber microbial fuel cells by incorporating enrofloxacin into the catalyst layer.

    Science.gov (United States)

    Liu, Weifeng; Cheng, Shaoan; Sun, Dan; Huang, Haobin; Chen, Jie; Cen, Kefa

    2015-10-15

    The inevitable growth of aerobic bacteria on the surface of air cathodes is an important factor reducing the performance stability of air cathode single-chamber membrane-free microbial fuel cells (MFCs). Thus searching for effective methods to inhibit the cathodic microbial growth is critical for the practical application of MFCs. In this study, enrofloxacin (ENR), a broad spectrum fluoroquinolone antibiotic, was incorporated into the catalyst layer of activated carbon air cathodes (ACACs) to inhibit the cathodic microbial growth. The biomass content on ACACs was substantially reduced by 60.2% with ENR treatment after 91 days of MFCs operation. As a result of the inhibited microbial growth, the oxygen reduction catalytic performance of the ENR treated ACACs was much stable compared to the fast performance decline of the untreated control. Consequently, a quite stable electricity production was obtained for the MFCs with the ENR treated ACACs, in contrast with a 22.5% decrease in maximum power density of the MFCs with the untreated cathode. ENR treatment of ACACs showed minimal effects on the anode performance. These results indicate that incorporating antibiotics into ACACs should be a simple and effective strategy to inhibit the microbial growth and improve the long-term stability of the performance of air cathode and the electricity production of MFCs. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Legal and security requirements for the air transportation of cyanotoxins and toxigenic cyanobacterial cells for legitimate research and analytical purposes.

    Science.gov (United States)

    Metcalf, J S; Meriluoto, J A O; Codd, G A

    2006-05-25

    Cyanotoxins are now recognised by international and national health and environment agencies as significant health hazards. These toxins, and the cells which produce them, are also vulnerable to exploitation for illegitimate purposes. Cyanotoxins are increasingly being subjected to national and international guidelines and regulations governing their production, storage, packaging and transportation. In all of these respects, cyanotoxins are coming under the types of controls imposed on a wide range of chemicals and other biotoxins of microbial, plant and animal origin. These controls apply whether cyanotoxins are supplied on a commercial basis, or stored and transported in non-commercial research collaborations and programmes. Included are requirements concerning the transportation of these toxins as documented by the United Nations, the International Air Transport Association (IATA) and national government regulations. The transportation regulations for "dangerous goods", which by definition include cyanotoxins, cover air mail, air freight, and goods checked in and carried on flights. Substances include those of determined toxicity and others of suspected or undetermined toxicity, covering purified cyanotoxins, cyanotoxin-producing laboratory strains and environmental samples of cyanobacteria. Implications of the regulations for the packaging and air-transport of dangerous goods, as they apply to cyanotoxins and toxigenic cyanobacteria, are discussed.

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

    Science.gov (United States)

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

    2014-10-07

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

  2. Thoracic air-leakage syndrome in allogeneic stem cell transplant recipients as a late complication of chronic graft-versus-host disease: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jae Wook; Kim, Song Soo; Jo, Daeg Yeon; Yun, Hwan Jung; Lee, Hyo Jin; Kim, Jin Hwan [Chungnam National University Hospital, Chungnam National University School of Medicine, Daejeon (Korea, Republic of)

    2016-08-15

    Air-leakage syndrome associated with graft-versus-host disease (GVHD) is a rare complication, but it is also reported as an independent predictor of a worse survival rate after stem cell transplantation. We report two cases of air-leakage syndrome associated with GVHD after allogeneic stem cell transplantation in acute leukemia patients who presented with spontaneous pneumomediastinum and subcutaneous emphysema, and finally death due to respiratory failure seven to eight months later.

  3. A CFD analysis on the effect of ambient conditions on the hygro-thermal stresses distribution in a planar ambient air-breathing PEM fuel cell

    OpenAIRE

    Maher A.R. Sadiq Al-Baghdadi

    2011-01-01

    The need for improved lifetime of air-breathing proton exchange membrane (PEM) fuel cells for portable applications necessitates that the failure mechanisms be clearly understood and life prediction models be developed, so that new designs can be introduced to improve long-term performance. An operating air-breathing PEM fuel cell has varying local conditions of temperature and humidity. As a result of in the changes in temperature and moisture, the membrane, GDL and bipolar plates will all e...

  4. Modeling and control of a proton exchange membrane fuel cell with the air compressor according to requested electrical current

    Directory of Open Access Journals (Sweden)

    Malekbala Mohammad Rahim

    2015-01-01

    Full Text Available The aim of this paper is to design and investigate the dynamic behavior of a PEM fuel cell system. Dynamic analysis of a PEM fuel cell system has been done in Matlab\\Simulink software according to electrical current that has been applied from hybrid system. In addition, dynamical fuel cell system has been explained according to oriented control that is started from air injection compressor model. Also hydrogen valve actuator has been controlled according to the compressor model. The results of the fuel cell dynamic model as well as the applied compressor model are fully validated based on the available results in the open literature. Finally, the effects of several operating parameters of the fuel cell system such as anode and cathode pressures, cell voltage, compressor voltage, compressor mass flow rate variation with respect to inlet pressure ratio, net and stack powers on the dynamic behavior of the hybrid system are investigated. The results show that the model can predict the dynamic behavior of the fuel cell system accurately and it can be used directly for any control purposes.

  5. EVALUATION OF MICROBIOLOGICAL AIR QUALITY INSIDE REFRIGERATION CELLS IN "AOSTA" MECHANIZED BRIGADE’S DEPENDENT REGIMENTS LOCATED IN EASTERN SICILY

    Directory of Open Access Journals (Sweden)

    A. Longo

    2011-01-01

    Full Text Available Authors evaluated the microbiological quality of air inside some refrigeration cells of the “AOSTA” Mechanized Brigade Regiments’ messes in Eastern Sicily, through an active air sampling and monitoring system. They used PCA medium plates for evaluation of microbial mesophilic amounts and Malt agar medium plates for the evaluation of mycotic flora. Study results showed values of TMC within a range of 25 – 273 CFU/m3 and values of mycotic concentrations within range of 10-1720 CFU/m3. All identified mycotic species belonged to Aspergillus and Penicillium genus. Furthermore, authors tested a duster, used for routine cleaning of all examined rooms, as it certainly represented a very important contamination means.

  6. In vitro genotoxicity of PAH mixtures and organic extract from urban air particles part II: human cell lines.

    Science.gov (United States)

    Sevastyanova, O; Binkova, B; Topinka, J; Sram, R J; Kalina, I; Popov, T; Novakova, Z; Farmer, P B

    2007-07-01

    Principal aims of this study were at first, to find a relevant human derived cell line to investigate the genotoxic potential of PAH-containing complex mixtures and second, to use this cell system for the analysis of DNA adduct forming activity of organic compounds bound onto PM10 particles. Particles were collected by high volume air samplers during summer and winter periods in three European cities (Prague, Kosice, and Sofia), representing different levels of air pollution. The genotoxic potential of extractable organic matter (EOM) was compared with the genotoxic potential of individual carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) as well as their artificial mixtures. Metabolically competent human hepatoma HepG2 cells, confluent cultures of human diploid lung fibroblasts (HEL), and the human monocytic leukemia cell line THP-1 were used as models. DNA adducts were analyzed by (32)P-postlabeling. The total DNA adduct levels induced in HepG2 cells after exposure to EOMs were higher than in HEL cells treated under the same conditions (15-190 versus 2-15adducts/10(8) nucleotides, in HepG2 and HEL cells, respectively). THP-1 cells exhibited the lowest DNA adduct forming activity induced by EOMs (1.5-3.7adducts/10(8) nucleotides). A direct correlation between total DNA adduct levels and c-PAH content in EOM was found for all EOMs in HepG2 cells incubated with 50microg EOM/ml (R=0.88; p=0.0192). This correlation was even slightly stronger when B[a]P content in EOMs and B[a]P-like adduct spots were analyzed (R=0.90; p=0.016). As THP-1 cells possess a limited metabolic capacity for most c-PAHs to form DNA reactive intermediates and are also more susceptible to toxic effects of PAHs and various EOM components, this cell line seemed to be an inappropriate system for genotoxicity studies of PAH-containing complex mixtures. The seasonal variability of genotoxic potential of extracts was stronger than variability among the three localities studied. In HepG2 cells

  7. Exploring the effects of symmetrical and asymmetrical relative humidity on the performance of H 2/air PEM fuel cell at different temperatures

    Science.gov (United States)

    Saleh, Mahmoud M.; Okajima, Takeoshi; Hayase, Masahiko; Kitamura, Fusao; Ohsaka, Takeo

    This article is dedicated to study the interlinked effects of symmetric relative humidity (RH), and asymmetric RH on the performance of H 2/air PEM fuel cell at different temperatures. The symmetric and asymmetric RH were achieved by setting the cathode relative humidity (RHC) and anode relative humidity (RHA) as equal and unequal values, respectively. The cell performance was evaluated by collecting polarization curves of the cell at different RH, RHC and RHA and at different cell temperatures (T cell). The polarization curves along with the measured internal cell resistance (membrane resistance) were discussed in the light of the present fuel cell theory. The results showed that symmetric relative humidity has different impacts depending on the cell temperature. While at RH of 35% the cell can show considerable performance at T cell = 70 °C, it is not so at T cell = 90 °C. At T cell = 70 °C, the cell potential increases with RH at lower and medium current densities but decreases with RH at higher currents. This was attributed to the different controlling processes at higher and lower current densities. This trend at 70 °C is completely destroyed at 90 °C. Operating our PEM fuel cell at dry H 2 gas conditions (RHA = 0%) is not detrimental as operating the cell at dry Air (O 2) conditions (RHC = 0%). At RHA = 0% and humidified air, water transport by back diffusion from the cathode to the anode at the employed experimental conditions can support reasonable rehydration of the membrane and catalysts. At RHA = 0, a possible minimum RHC for considerable cell operation is temperature dependent. At RHC = 0 conditions, the cell can operate only at RHA = 100% with a loss that depends on T cell. It was found that the internal cell resistance depends on RH, RHA, RHC and T cell and it is consistent with the observed cell performance.

  8. Characteristic Evaluation on the Cooling Performance of an Electrical Air Conditioning System Using R744 for a Fuel Cell Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Moo-Yeon Lee

    2012-05-01

    Full Text Available The objective of this study was to investigate the cooling performance characteristics of an electrical air conditioning system using R744 as an alternative of R-134a for a fuel cell electric vehicle. In order to analyze the cooling performance characteristics of the air conditioning system using R744 for a fuel cell electric vehicle, an electrical air conditioning system using R744 was developed and tested under various operating conditions according to both inlet air conditions of the gas cooler and evaporator and compressor speed. The cooling capacity and coefficient of performance (COP forcooling of the tested air conditioning system were up to 6.4 kW and 2.5, respectively. In addition, the electrical air conditioning system with R744 using an inverter driven compressor showed better performance than the conventional air conditioning system with R-134a under the same operating conditions. The observed cooling performance of the developed electrical air conditioning system was found to be sufficient for cooling loads under various real driving conditions for a fuel cell electric vehicle.

  9. Development and characterization of a novel air-breathing micro direct methanol fuel cell stack for portable applications

    International Nuclear Information System (INIS)

    Liu, Xiaowei; Zhang, Bo; Zhang, Yufeng; He, Hong; Li, Jianmin; Wang, Shibo; Yuan, Zhenyu; Deng, Huichao

    2010-01-01

    An air-breathing 10-cell micro direct methanol fuel cell (µDMFC) stack with four anode feeding patterns is designed, fabricated and tested. For a better understanding of the operational characteristics of both the single cell and the stack, a two-dimensional numerical model is established and calculated. Employing micro-stamping technology, the current collectors of each single cell are microfabricated on the stainless steel plate with a thickness of 300 µm. The single µDMFC is first tested under various operating parameters. On the basis of the simulation and experimental observation of the single cell performance, the µDMFC stack performance is thoroughly analyzed with different anode feeding patterns. The results indicate that the µDMFC stack with pattern B can ensure the uniform performance of each single cell and generate the highest power output. With pattern B, further experiments are carried out to investigate the influence of the anode flow rate on the stack performance. As a result, the µDMFC stack achieves the best performance with the maximum power density of about 24.75 mW cm −2 at 5.0 ml min −1 . Finally, the stack is successfully applied to two electronic devices of different rated power

  10. Development and characterization of a novel air-breathing micro direct methanol fuel cell stack for portable applications

    Science.gov (United States)

    Liu, Xiaowei; Zhang, Bo; Zhang, Yufeng; He, Hong; Li, Jianmin; Wang, Shibo; Yuan, Zhenyu; Deng, Huichao

    2010-10-01

    An air-breathing 10-cell micro direct methanol fuel cell (µDMFC) stack with four anode feeding patterns is designed, fabricated and tested. For a better understanding of the operational characteristics of both the single cell and the stack, a two-dimensional numerical model is established and calculated. Employing micro-stamping technology, the current collectors of each single cell are microfabricated on the stainless steel plate with a thickness of 300 µm. The single µDMFC is first tested under various operating parameters. On the basis of the simulation and experimental observation of the single cell performance, the µDMFC stack performance is thoroughly analyzed with different anode feeding patterns. The results indicate that the µDMFC stack with pattern B can ensure the uniform performance of each single cell and generate the highest power output. With pattern B, further experiments are carried out to investigate the influence of the anode flow rate on the stack performance. As a result, the µDMFC stack achieves the best performance with the maximum power density of about 24.75 mW cm-2 at 5.0 ml min-1. Finally, the stack is successfully applied to two electronic devices of different rated power.

  11. The growth rate and size of the mastoid air cell system and mastoid bone: a review and reference.

    Science.gov (United States)

    Cinamon, Udi

    2009-06-01

    This review suggests a reference to the postnatal growth of mastoid air cells and bone. Information was retrieved from studies having large consecutive age groups, in order to reveal a development pattern. Data regarding origin, gender, and antibiotic treatment was investigated as well. Most measurements were obtained by planimetry. Assessment of the various data sources suggested the antrum to be well developed at birth (1-1.5 cm2), the mastoid cells to be about 3.5-4 cm2 at 1 year, followed by a linear growth till the age of 6 (1-1.2 cm2/year), having a slower increment up to adult size at puberty (approximately 12 cm2). The mastoid bone expansion is about 0.6-0.9 cm/year in length and width and 0.4 cm/year in depth in the first year, followed by half that rate until the age of 6-7. At puberty there was a slower sprout reaching adult size. Different ethnic groups share similar mastoid aeration and bone growth patterns. There were no differences between mastoid aeration measured at the pre-antibiotic era and after its widespread use. In conclusion, there are three distinguishable phases of mastoid pneumatization from birth till reaching final size. Bone and air cell compartments share a similar growth pattern; bone expansion lags behind aeration. Antibiotic treatment for otitis may have no impact upon mastoid aeration.

  12. Air pollution upregulates endothelial cell procoagulant activity via ultrafine particle-induced oxidant signaling and tissue factor expression.

    Science.gov (United States)

    Snow, S J; Cheng, W; Wolberg, A S; Carraway, M S

    2014-07-01

    Air pollution exposure is associated with cardiovascular events triggered by clot formation. Endothelial activation and initiation of coagulation are pathophysiological mechanisms that could link inhaled air pollutants to vascular events. Here we investigated the underlying mechanisms of increased endothelial cell procoagulant activity following exposure to soluble components of ultrafine particles (soluble UF). Human coronary artery endothelial cells (HCAEC) were exposed to soluble UF and assessed for their ability to trigger procoagulant activity in platelet-free plasma. Exposed HCAEC triggered earlier thrombin generation and faster fibrin clot formation, which was abolished by an anti-tissue factor (TF) antibody, indicating TF-dependent effects. Soluble UF exposure increased TF mRNA expression without compensatory increases in key anticoagulant proteins. To identify early events that regulate TF expression, we measured endothelial H2O2 production following soluble UF exposure and identified the enzymatic source. Soluble UF exposure increased endothelial H2O2 production, and antioxidants attenuated UF-induced upregulation of TF, linking the procoagulant responses to reactive oxygen species (ROS) formation. Chemical inhibitors and RNA silencing showed that NOX-4, an important endothelial source of H2O2, was involved in UF-induced upregulation of TF mRNA. These data indicate that soluble UF exposure induces endothelial cell procoagulant activity, which involves de novo TF synthesis, ROS production, and the NOX-4 enzyme. These findings provide mechanistic insight into the adverse cardiovascular effects associated with air pollution exposure. Published by Oxford University Press on behalf of Toxicological Sciences 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  13. High cell density cultivation of Pseudomonas putida KT2440 using glucose without the need for oxygen enriched air supply.

    Science.gov (United States)

    Davis, Reeta; Duane, Gearoid; Kenny, Shane T; Cerrone, Federico; Guzik, Maciej W; Babu, Ramesh P; Casey, Eoin; O'Connor, Kevin E

    2015-04-01

    High Cell Density (HCD) cultivation of bacteria is essential for the majority of industrial processes to achieve high volumetric productivity (g L(-1) h(-1) ) of a bioproduct of interest. This study developed a fed batch bioprocess using glucose as sole carbon and energy source for the HCD of the well described biocatalyst Pseudomonas putida KT2440 without the supply of oxygen enriched air. Growth kinetics data from batch fermentations were used for building a bioprocess model and designing feeding strategies. An exponential followed by linearly increasing feeding strategy of glucose was found to be effective in maintaining biomass productivity while also delaying the onset of dissolved oxygen (supplied via compressed air) limitation. A final cell dry weight (CDW) of 102 g L(-1) was achieved in 33 h with a biomass productivity of 3.1 g L(-1) h(-1) which are the highest ever reported values for P. putida strains using glucose without the supply of pure oxygen or oxygen enriched air. The usefulness of the biomass as a biocatalyst was demonstrated through the production of the biodegradable polymer polyhydroxyalkanoate (PHA). When nonanoic acid (NA) was supplied to the glucose grown cells of P. putida KT2440, it accumulated 32% of CDW as PHA in 11 h (2.85 g L(-1) h(-1) ) resulting in a total of 0.56 kg of PHA in 18 L with a yield of 0.56 g PHA g NA(-1) . © 2014 Wiley Periodicals, Inc.

  14. Tracheobronchial air-liquid interface cell culture: a model for innate mucosal defense of the upper airways?

    Science.gov (United States)

    Kesimer, Mehmet; Kirkham, Sara; Pickles, Raymond J.; Henderson, Ashley G.; Alexis, Neil E.; DeMaria, Genevieve; Knight, David; Thornton, David J.; Sheehan, John K.

    2009-01-01

    Human tracheobronchial epithelial cells grown in air-liquid interface culture have emerged as a powerful tool for the study of airway biology. In this study, we have investigated whether this culture system produces “mucus” with a protein composition similar to that of in vivo, induced airway secretions. Previous compositional studies of mucous secretions have greatly underrepresented the contribution of mucins, which are major structural components of normal mucus. To overcome this limitation, we have used a mass spectrometry-based approach centered on prior separation of the mucins from the majority of the other proteins. Using this approach, we have compared the protein composition of apical secretions (AS) from well-differentiated primary human tracheobronchial cells grown at air-liquid interface and human tracheobronchial normal induced sputum (IS). A total of 186 proteins were identified, 134 from AS and 136 from IS; 84 proteins were common to both secretions, with host defense proteins being predominant. The epithelial mucins MUC1, MUC4, and MUC16 and the gel-forming mucins MUC5B and MUC5AC were identified in both secretions. Refractometry showed that the gel-forming mucins were the major contributors by mass to both secretions. When the composition of the IS was corrected for proteins that were most likely derived from saliva, serum, and migratory cells, there was considerable similarity between the two secretions, in particular, in the category of host defense proteins, which includes the mucins. This shows that the primary cell culture system is an important model for study of aspects of innate defense of the upper airways related specifically to mucus consisting solely of airway cell products. PMID:18931053

  15. Enthalpy analysis and Heat Exchanger Sizing of an Air-cooled Proton Exchange Membrane Fuel Cell System

    DEFF Research Database (Denmark)

    Gao, Xin; Berning, Torsten; Kær, Søren Knudsen

    Proton exchange membrane fuel cells (PEMFC’s) are becoming increasingly popular for uninterrupted power supply especially in remote areas. In the case of telecom back-up operations, PEMFC systems are often placed in areas of extreme climates, e.g. in Norway or Canada where the temperatures drop...... or an ordinary heat exchanger can fulfill the heat recovery demand. Despite the fact that the air enters the stack at a cold temperature, even the forefront of the stack is at a much elevated and desired stack temperature with the help of supplying an acceptable amount of power to an electric stack heater. So...

  16. Comparison of adsorption systems using natural gas fired fuel cell as heat source, for residential air conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Clausse, M.; Meunier, F. [LGP2ES, Cnam-IFFI (EA21), case 331, 292 rue Saint-Martin, 75141 Paris Cedex 03 (France); Coulie, J.; Herail, E. [N-GHY, Site Industriel Saint Antoine, ZI Montplaisir, 51 rue Isaac Newton, 81000 Albi (France)

    2009-06-15

    This article aims to evaluate the performances of an adsorption system driven thanks to the heat rejected by the post-combustion exhaust gases of a reformer/fuel cell system for residential air-conditioning application. Three adsorption pairs were compared: activated carbon/methanol, silica gel/water and zeolite/water. Taking into account both cooling power and sensitivity to performances of the heat rejection and recovery exchangers, it appears that zeolite 13X/water is the adsorption pair giving the best performance for this application. Nevertheless, a more detailed model would be of interest to better quantify the heat transfer impact on performance. (author)

  17. Self-assembled nitrogen-doped fullerenes and their catalysis for fuel cell and rechargeable metal-air battery applications.

    Science.gov (United States)

    Noh, Seung Hyo; Kwon, Choah; Hwang, Jeemin; Ohsaka, Takeo; Kim, Beom-Jun; Kim, Tae-Young; Yoon, Young-Gi; Chen, Zhongwei; Seo, Min Ho; Han, Byungchan

    2017-06-08

    In this study, we report self-assembled nitrogen-doped fullerenes (N-fullerene) as non-precious catalysts, which are active for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), and thus applicable for energy conversion and storage devices such as fuel cells and metal-air battery systems. We screen the best N-fullerene catalyst at the nitrogen doping level of 10 at%, not at the previously known doping level of 5 or 20 at% for graphene. We identify that the compressive surface strain induced by doped nitrogen plays a key role in the fine-tuning of catalytic activity.

  18. 76 FR 13851 - National Emission Standards for Hazardous Air Pollutants: Mercury Emissions From Mercury Cell...

    Science.gov (United States)

    2011-03-14

    ... information identified as CBI only to the following address: Roberto Morales, OAQPS Document Control Officer... these average values being slightly less than 450 g/day per facility. Therefore, the information we... benefits for non-air quality related health and environmental values. The potential problems associated...

  19. MoO3–Au composite interfacial layer for high efficiency and air-stable organic solar cells

    DEFF Research Database (Denmark)

    Pan, Hongbin; Zuo, Lijian; Fu, Weifei

    2013-01-01

    Efficient and stable polymer bulk-heterojunction solar cells based on regioregular poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PC61BM) blend active layer have been fabricated with a MoO3–Au co-evaporation composite film as the anode interfacial layer (AIL). The optical...... resistance and thus improving the fill factor and efficiency of the devices. Additionally, the air stability of devices with different AILs (MoO3–Au composite, MoO3 and PEDOT:PSS) were studied and it was found that the MoO3–Au composite layer remarkably improved the stability of the solar cells with shelf...

  20. Growth of airway epithelial cells at an air-liquid interface changes both the response to particle exposure and iron homeostasis

    Science.gov (United States)

    We tested the hypothesis that 1) relative to submerged cells, airway epithelial cells grown at an air-liquid interface and allowed to differentiate would have an altered response to particle exposure and 2) that these differences would be associated with indices of iron homeostas...

  1. B cells are required for Aire-deficient mice to develop multi-organ autoinflammation: A therapeutic approach for APECED patients.

    Science.gov (United States)

    Gavanescu, Irina; Benoist, Christophe; Mathis, Diane

    2008-09-02

    Autoimmune regulator (Aire)-deficient mice and humans have circulating autoantibodies against a multitude of organs and multiorgan autoinflammatory infiltrates. It is not known to what extent autoantibodies or their source, B lymphocytes, are required for disease onset or progression. We show in this research that B cells must be present for Aire-deficient mice to develop fulminant infiltrates. We found no evidence that autoantibodies were directly pathogenic; rather, B cells appeared to play a critical early role in T cell priming or expansion. A therapeutic reagent directed against B cells, Rituximab, induced remission of the autoimmune disease in Aire-deficient mice, raising the hope of applying it to human patients with autoimmune-polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED).

  2. Investigations on fabrication and lifetime performance of self - air breathing direct hydrogen micro fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Giddey, S.; Badwal, S.P.S.; Ciacchi, F.T.; Fini, D. [CSIRO Energy Technology, Private Bag 33, Clayton South, Victoria 3169 (Australia); Sexton, B.A.; Glenn, F.; Leech, P.W. [CSIRO Materials Science and Engineering, Private Bag 33, Clayton South, Victoria 3169 (Australia)

    2010-03-15

    There is an ever - increasing demand for more powerful, compact and longer - life power modules for portable electronic devices for leisure, communication and computing. Micro fuel cells have the potential to replace battery packs for portable electronic appliances because of their high power density, longer operating and standby times, and substantially shorter recharging times. However, fuel cells have stringent operating requirements, including no fuel leakage, water formed in the electrochemical reactions, heat dissipation, robustness, easy and safe use, and reliability. Due to the large market potential, several companies are currently involved in the development of micro fuel cells. For application of fuel cells as a battery charger or in a battery replacement market, the cells require simplification in terms of their construction and operation and must have volumetric power densities equivalent to or better than those of existing battery power packs. This paper discusses results of investigation on methods and materials for direct hydrogen micro fuel cells as well as the lifetime performance of single cells and 2 W{sub e} arrays. The paper also reviews the global technology development status for the direct hydrogen micro fuel cell and compares its salient features with other types of micro fuel cells. (author)

  3. The thymic orchestration involving Aire, miRNAs and cell-cell interactions during the induction of central tolerance

    OpenAIRE

    Geraldo eAleixo Passos; DANIELLA AREAS MENDES-DA-CRUZ; Ernna Hérida Oliveira

    2015-01-01

    Developing thymocytes interact sequentially with two distinct structures within the thymus: the cortex and medulla. Surviving single-positive and double-positive thymocytes from the cortex migrate into the medulla, where they interact with medullary thymic epithelial cells (mTECs). These cells ectopically express a vast set of peripheral tissue antigens (PTAs), a property termed promiscuous gene expression that is associated with the presentation of PTAs by mTECs to thymocytes. Thymocyte clon...

  4. A simple nanostructured polymer/ZnO hybrid solar cell - preparation and operation in air

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Thomann, Yi; Thomann, Ralf

    2008-01-01

    A detailed description is given of the preparation of a polymer solar cell and its characterization. The solar cell can be prepared entirely in the ambient atmosphere by solution processing without the use of vacuum coating steps, and it can be operated in the ambient atmosphere with good......)-oxy-carbonyldithiophene) (P3MHOCT), which through a thermal treatment is converted to the insoluble form poly(3-carboxydithiophene) (P3CT) that generally gives stable polymer solar cells. The devices employed a solution based silver back electrode. One advantage is that preparation of the devices is very simple and can...

  5. BIOCHEMICAL IDENTIFICATION OF FUNGAL SPECIES FROM AIR INSIDE REFRIGERATION CELLS IN “AOSTA” MECHANIZED BRIGADE’S REGIMENTS LOCATED IN ORIENTAL SICILY

    Directory of Open Access Journals (Sweden)

    A.M.F. Marino

    2011-01-01

    Full Text Available In our study, we have identified and typed mycotic colonies after isolation from air sampled in refrigeration cells of the “Aosta” Mechanized Brigade’s Regiments, in Eastern Sicily, through an active air sampling system. Typing has been carried out through macro and microscopic examinations and biochemical identification system machine called “Biolog”. All isolated mycotic species belonged to Aspergillus and Penicillium genus, which have both direct and indirect pathogenic concern for human beings.

  6. Detonation Nanodiamond Toxicity in Human Airway Epithelial Cells Is Modulated by Air Oxidation

    Science.gov (United States)

    Detonational nanodiamonds (DND), a nanomaterial with an increasing range of industrial and biomedical applications, have previously been shown to induce a pro-inflammatory response in cultured human airway epithelial cells (HAEC). We now show that surface modifications induced by...

  7. Transformation of a beta gamma hot-cell under air in a tight hot-cell under inert gas

    International Nuclear Information System (INIS)

    Lambert, G.

    1981-05-01

    For several years now, fuel elements from graphite gas reactors have been stored in pools at the Cadarache Center after having been subjected (in general) to laboratory examinations. The CEA has adopted the following re-transfer procedure for these fuel elements while awaiting reprocessing: the fuel elements are extracted from their existing cartridges and transferred into new welded stainless steel containers capable of assuring long term storage. The storage, however, envisaged is temporary and is realized in the Pegase pool, specially adapted for this purpose. This re-transfer operation is envisaged for some 2.300 containers. All the appropriate safety measures will be taken. The various different fuel materials handled are often highly irradiated. The presence of water in certain containers due to loss of leaktightness has led to a series of chemical reactions (corrosion of uranium by water, reactions with magnesium, formation of hydrides). As a result, existing envelopes can contain UO 2 , UH 3 and hydrogen; operations must therefore being carried out in an inert atmosphere (preferably argon). The re-transfer process can not therefore be carried out in a conventional cell. It is therefore envisaged to carry out this work in a leaktight cell in an inert atmosphere. A laboratory cell could be modified to perform these functions. This cell would be reconverted to its original state when operations terminate (in about 3 years time) [fr

  8. Heme oxygenase-1 protects endothelial cells from the toxicity of air pollutant chemicals

    International Nuclear Information System (INIS)

    Lawal, Akeem O.; Zhang, Min; Dittmar, Michael; Lulla, Aaron; Araujo, Jesus A.

    2015-01-01

    Diesel exhaust particles (DEPs) are a major component of diesel emissions, responsible for a large portion of their toxicity. In this study, we examined the toxic effects of DEPs on endothelial cells and the role of DEP-induced heme oxygenase-1 (HO-1) expression. Human microvascular endothelial cells (HMECs) were treated with an organic extract of DEPs from an automobile engine (A-DEP) or a forklift engine (F-DEP) for 1 and 4 h. ROS generation, cell viability, lactate dehydrogenase leakage, expression of HO-1, inflammatory genes, cell adhesion molecules and unfolded protein respone (UPR) gene were assessed. HO-1 expression and/or activity were inhibited by siRNA or tin protoporphyrin (Sn PPIX) and enhanced by an expression plasmid or cobalt protoporphyrin (CoPPIX). Exposure to 25 μg/ml of A-DEP and F-DEP significantly induced ROS production, cellular toxicity and greater levels of inflammatory and cellular adhesion molecules but to a different degree. Inhibition of HO-1 enzymatic activity with SnPPIX and silencing of the HO-1 gene by siRNA enhanced DEP-induced ROS production, further decreased cell viability and increased expression of inflammatory and cell adhesion molecules. On the other hand, overexpression of the HO-1 gene by a pcDNA 3.1D/V5-HO-1 plasmid significantly mitigated ROS production, increased cell survival and decreased the expression of inflammatory genes. HO-1 expression protected HMECs from DEP-induced prooxidative and proinflammatory effects. Modulation of HO-1 expression could potentially serve as a therapeutic target in an attempt to inhibit the cardiovascular effects of ambient PM. - Highlights: • We examined the role of HO-1 expression on diesel exhaust particle (DEP) in endothelial cells. • DEPs exert cytotoxic and inflammatory effects on human microvascular endothelial cells (HMECs). • DEPs induce HO-1 expression in HMECs. • HO-1 protects against the oxidative stress induced by DEps. • HO-1 attenuates the proinflammatory effects

  9. Uni Sitotoksisitas Ekstrak Air Asam Jawa 5% terhadap Cell Line BHK-21

    Directory of Open Access Journals (Sweden)

    Erawati Wulandari

    2015-10-01

    Full Text Available Tamarindus indica (tamarind is an established traditional medicine. Pulpa tamarindorum includes vitamin C, protein, fat, glucose, citric acid, etc. Citric acid is a root canal irrigant and vitamin C an antioxidant. This study aimed to elucidate the cytotoxicity of 5% tamarind extract as a root canal irrigant to the cell line BHK-21. Eighteen cultures of cell line BHK-21 were divided into 2 groups. Sterila aquabidest was placed on the group 1 cultures (as control, and 5% tamarind extract was on the group 2, for 2.5 minutes each, and then the percentage of the living and dead cells were counted. The collected data were statistically analyzed by using independent t test to 0.05 limit of significance. The results showed 1% of dead cells in group 1 and 22% in group 2, and that there was a significant difference between the effect of 5% tamarind extract and that of sterile aquabidest (p<0.05. It was concluded that 5% tamarind extract is cytotoxic to the cell line BHK-21.

  10. Enhanced electrode-reducing rate during the enrichment process in an air-cathode microbial fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Shun' ichi [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki (Japan). Bio-Medical Research Inst.; J. Craig Venter Institute, San Diego, CA (United States); Japan Society for the Promotion of Science (JSPS), Tokyo (Japan); Logan, Bruce E. [Penn State Univ., University Park, PA (United States). Dept. of Civil and Environmental Engineering; Sekiguchi, Yuji [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki (Japan). Bio-Medical Research Inst.

    2012-05-15

    The improvement in electricity generation during the enrichment process of a microbial consortium was analyzed using an air-cathode microbial fuel cell (MFC) repeatedly fed with acetate that was originally inoculated with sludge from an anaerobic digester. The anodic maximum current density produced by the anode biofilm increased from 0.12 mA/cm{sup 2} at day 28 to 1.12 mA/cm{sup 2} at day 105. However, the microbial cell density on the carbon cloth anode increased only three times throughout this same time period from 0.21 to 0.69 mg protein/cm{sup 2}, indicating that the biocatalytic activity of the consortium was also enhanced. The microbial activity was calculated to have a per biomass anode-reducing rate of 374 {mu}mol electron g protein{sup -1} min{sup -1} at day 28 and 1,002 {mu}mol electron g protein{sup -1} min{sup -1} at day 105. A bacterial community analysis of the anode biofilm revealed that the dominant phylotype, which was closely related to the known exoelectrogenic bacterium, Geobacter sulfurreducens, showed an increase in abundance from 32% to 70% of the total microbial cells. Fluorescent in situ hybridization observation also showed the increase of Geobacter-like phylotypes from 53% to 72%. These results suggest that the improvement of microbial current generation in microbial fuel cells is a function of both microbial cell growth on the electrode and changes in the bacterial community highly dominated by a known exoelectrogenic bacterium during the enrichment process. (orig.)

  11. Spatial distribution of bacterial communities on volumetric and planar anodes in single-chamber air-cathode microbial fuel cells

    KAUST Repository

    Vargas, Ignacio T.

    2013-05-29

    Pyrosequencing was used to characterize bacterial communities in air-cathode microbial fuel cells across a volumetric (graphite fiber brush) and a planar (carbon cloth) anode, where different physical and chemical gradients would be expected associated with the distance between anode location and the air cathode. As expected, the stable operational voltage and the coulombic efficiency (CE) were higher for the volumetric anode than the planar anode (0.57V and CE=22% vs. 0.51V and CE=12%). The genus Geobacter was the only known exoelectrogen among the observed dominant groups, comprising 57±4% of recovered sequences for the brush and 27±5% for the carbon-cloth anode. While the bacterial communities differed between the two anode materials, results showed that Geobacter spp. and other dominant bacterial groups were homogenously distributed across both planar and volumetric anodes. This lends support to previous community analysis interpretations based on a single biofilm sampling location in these systems. © 2013 Wiley Periodicals, Inc.

  12. New highly active oxygen reduction electrode for PEM fuel cell and Zn/air battery applications (NORA). Final report

    Energy Technology Data Exchange (ETDEWEB)

    Thiele, D.; Zuettel, A.

    2008-04-15

    This illustrated final report for the Swiss Federal Office of Energy (SFOE) presents the results of a project concerning a new, highly active oxygen reduction electrode for PEM fuel cell and zinc/air battery applications. The goal of this project was, according to the authors, to increase the efficiency of the oxygen reduction reaction by lowering the activation polarisation through the right choice of catalyst and by lowering the concentration polarisation. In this work, carbon nanotubes are used as support material. The use of these nanotubes grown on perovskites is discussed. Theoretical considerations regarding activation polarisation are discussed and alternatives to the use of platinum are examined. The results of experiments carried out are presented in graphical and tabular form. The paper is completed with a comprehensive list of references.

  13. Simultaneous processes of electricity generation and ceftriaxone sodium degradation in an air-cathode single chamber microbial fuel cell

    Science.gov (United States)

    Wen, Qing; Kong, Fanying; Zheng, Hongtao; Yin, Jinling; Cao, Dianxue; Ren, Yueming; Wang, Guiling

    2011-03-01

    A single chamber microbial fuel cell (MFC) with an air-cathode is successfully demonstrated using glucose-ceftriaxone sodium mixtures or ceftriaxone sodium as fuel. Results show that the ceftriaxone sodium can be biodegraded and produce electricity simultaneously. Interestingly, these ceftriaxone sodium-glucose mixtures play an active role in production of electricity. The maximum power density is increased in comparison to 1000 mg L-1 glucose (19 W m-3) by 495% for 50 mg L-1 ceftriaxone sodium + 1000 mg L-1 glucose (113 W m-3), while the maximum power density is 11 W m-3 using 50 mg L-1 ceftriaxone sodium as the sole fuel. Moreover, ceftriaxone sodium biodegradation rate reaches 91% within 24 h using the MFC in comparison with 51% using the traditional anaerobic reactor. These results indicate that some toxic and bio-refractory organics such as antibiotic wastewater might be suitable resources for electricity generation using the MFC technology.

  14. Sustainable design of high-performance microsized microbial fuel cell with carbon nanotube anode and air cathode.

    Science.gov (United States)

    Mink, Justine E; Hussain, Muhammad Mustafa

    2013-08-27

    Microbial fuel cells (MFCs) are a promising alternative energy source that both generates electricity and cleans water. Fueled by liquid wastes such as wastewater or industrial wastes, the microbial fuel cell converts waste into energy. Microsized MFCs are essentially miniature energy harvesters that can be used to power on-chip electronics, lab-on-a-chip devices, and/or sensors. As MFCs are a relatively new technology, microsized MFCs are also an important rapid testing platform for the comparison and introduction of new conditions or materials into macroscale MFCs, especially nanoscale materials that have high potential for enhanced power production. Here we report a 75 μL microsized MFC on silicon using CMOS-compatible processes and employ a novel nanomaterial with exceptional electrochemical properties, multiwalled carbon nanotubes (MWCNTs), as the on-chip anode. We used this device to compare the usage of the more commonly used but highly expensive anode material gold, as well as a more inexpensive substitute, nickel. This is the first anode material study done using the most sustainably designed microsized MFC to date, which utilizes ambient oxygen as the electron acceptor with an air cathode instead of the chemical ferricyanide and without a membrane. Ferricyanide is unsustainable, as the chemical must be continuously refilled, while using oxygen, naturally found in air, makes the device mobile and is a key step in commercializing this for portable technology such as lab-on-a-chip for point-of-care diagnostics. At 880 mA/m(2) and 19 mW/m(2) the MWCNT anode outperformed the others in both current and power densities with between 6 and 20 times better performance. All devices were run for over 15 days, indicating a stable and high-endurance energy harvester already capable of producing enough power for ultra-low-power electronics and able to consistently power them over time.

  15. Sustainable design of high-performance microsized microbial fuel cell with carbon nanotube anode and air cathode

    KAUST Repository

    Mink, Justine E.

    2013-08-27

    Microbial fuel cells (MFCs) are a promising alternative energy source that both generates electricity and cleans water. Fueled by liquid wastes such as wastewater or industrial wastes, the microbial fuel cell converts waste into energy. Microsized MFCs are essentially miniature energy harvesters that can be used to power on-chip electronics, lab-on-a-chip devices, and/or sensors. As MFCs are a relatively new technology, microsized MFCs are also an important rapid testing platform for the comparison and introduction of new conditions or materials into macroscale MFCs, especially nanoscale materials that have high potential for enhanced power production. Here we report a 75 μL microsized MFC on silicon using CMOS-compatible processes and employ a novel nanomaterial with exceptional electrochemical properties, multiwalled carbon nanotubes (MWCNTs), as the on-chip anode. We used this device to compare the usage of the more commonly used but highly expensive anode material gold, as well as a more inexpensive substitute, nickel. This is the first anode material study done using the most sustainably designed microsized MFC to date, which utilizes ambient oxygen as the electron acceptor with an air cathode instead of the chemical ferricyanide and without a membrane. Ferricyanide is unsustainable, as the chemical must be continuously refilled, while using oxygen, naturally found in air, makes the device mobile and is a key step in commercializing this for portable technology such as lab-on-a-chip for point-of-care diagnostics. At 880 mA/m2 and 19 mW/m2 the MWCNT anode outperformed the others in both current and power densities with between 6 and 20 times better performance. All devices were run for over 15 days, indicating a stable and high-endurance energy harvester already capable of producing enough power for ultra-low-power electronics and able to consistently power them over time. © 2013 American Chemical Society.

  16. Method for the integrated operation of a fuel cell and an air separator

    NARCIS (Netherlands)

    Hemmes, K.

    2007-01-01

    The invention relates to a system and method for integrating renewable energy and a fuel cell for the production of electricity and hydrogen, wherein this comprises the use of renewable energy as fluctuating energy source for the production of electricity and also comprises the use of at least one

  17. Detonation cell size measurements in high-temperature hydrogen-air-steam mixtures at the BNL high-temperature combustion facility

    Energy Technology Data Exchange (ETDEWEB)

    Ciccarelli, G.; Ginsberg, T.; Boccio, J.L. [and others

    1997-11-01

    The High-Temperature Combustion Facility (HTCF) was designed and constructed with the objective of studying detonation phenomena in mixtures of hydrogen-air-steam at initially high temperatures. The central element of the HTCF is a 27-cm inner-diameter, 21.3-m long cylindrical test vessel capable of being heating to 700K {+-} 14K. A unique feature of the HTCF is the {open_quotes}diaphragmless{close_quotes} acetylene-oxygen gas driver which is used to initiate the detonation in the test gas. Cell size measurements have shown that for any hydrogen-air-steam mixture, increasing the initial mixture temperature, in the range of 300K to 650K, while maintaining the initial pressure of 0.1 MPa, decreases the cell size and thus makes the mixture more detonable. The effect of steam dilution on cell size was tested in stoichiometric and off-stoichiometric (e.g., equivalence ratio of 0.5) hydrogen-air mixtures. Increasing the steam dilution in hydrogen-air mixtures at 0.1 MPa initial pressure increases the cell size, irrespective of initial temperature. It is also observed that the desensitizing effect of steam diminished with increased initial temperature. A 1-dimensional, steady-state Zel`dovich, von Neumann, Doring (ZND) model, with full chemical kinetics, has been used to predict cell size for hydrogen-air-steam mixtures at different initial conditions. Qualitatively the model predicts the overall trends observed in the measured cell size versus mixture composition and initial temperature and pressure. It was found that the proportionality constant used to predict detonation cell size from the calculated ZND model reaction zone varies between 10 and 100 depending on the mixture composition and initial temperature. 32 refs., 35 figs.

  18. Detonation cell size measurements in high-temperature hydrogen-air-steam mixtures at the BNL high-temperature combustion facility

    International Nuclear Information System (INIS)

    Ciccarelli, G.; Ginsberg, T.; Boccio, J.L.

    1997-11-01

    The High-Temperature Combustion Facility (HTCF) was designed and constructed with the objective of studying detonation phenomena in mixtures of hydrogen-air-steam at initially high temperatures. The central element of the HTCF is a 27-cm inner-diameter, 21.3-m long cylindrical test vessel capable of being heating to 700K ± 14K. A unique feature of the HTCF is the 'diaphragmless' acetylene-oxygen gas driver which is used to initiate the detonation in the test gas. Cell size measurements have shown that for any hydrogen-air-steam mixture, increasing the initial mixture temperature, in the range of 300K to 650K, while maintaining the initial pressure of 0.1 MPa, decreases the cell size and thus makes the mixture more detonable. The effect of steam dilution on cell size was tested in stoichiometric and off-stoichiometric (e.g., equivalence ratio of 0.5) hydrogen-air mixtures. Increasing the steam dilution in hydrogen-air mixtures at 0.1 MPa initial pressure increases the cell size, irrespective of initial temperature. It is also observed that the desensitizing effect of steam diminished with increased initial temperature. A 1-dimensional, steady-state Zel'dovich, von Neumann, Doring (ZND) model, with full chemical kinetics, has been used to predict cell size for hydrogen-air-steam mixtures at different initial conditions. Qualitatively the model predicts the overall trends observed in the measured cell size versus mixture composition and initial temperature and pressure. It was found that the proportionality constant used to predict detonation cell size from the calculated ZND model reaction zone varies between 10 and 100 depending on the mixture composition and initial temperature. 32 refs., 35 figs

  19. The Lymphotoxin Pathway Regulates Aire-Independent Expression of Ectopic Genes and Chemokines in Thymic Stromal Cells1

    Science.gov (United States)

    Seach, Natalie; Ueno, Tomoo; Fletcher, Anne L.; Lowen, Tamara; Mattesich, Monika; Engwerda, Christian R.; Scott, Hamish S.; Ware, Carl F.; Chidgey, Ann P.; Gray, Daniel H. D.; Boyd, Richard L.

    2009-01-01

    Medullary thymic epithelial cells (mTEC) play an important and unique role in central tolerance, expressing tissue-restricted Ags (TRA) which delete thymocytes autoreactive to peripheral organs. Since deficiencies in this cell type or activity can lead to devastating autoimmune diseases, it is important to understand the factors which regulate mTEC differentiation and function. Lymphotoxin (LT) ligands and the LTβR have been recently shown to be important regulators of mTEC biology; however, the precise role of this pathway in the thymus is not clear. In this study, we have investigated the impact of this signaling pathway in greater detail, focusing not only on mTEC but also on other thymic stromal cell subsets. LTβR expression was found in all TEC subsets, but the highest levels were detected in MTS-15+ thymic fibroblasts. Rather than directing the expression of the autoimmune regulator Aire in mTEC, we found LTβR signals were important for TRA expression in a distinct population of mTEC characterized by low levels of MHC class II (mTEClow), as well as maintenance of MTS-15+ fibroblasts. In addition, thymic stromal cell subsets from LT-deficient mice exhibit defects in chemokine production similar to that found in peripheral lymphoid organs of Lta−/− and Ltbr−/− mice. Thus, we propose a broader role for LTα1β2-LTβR signaling in the maintenance of the thymic microenvironments, specifically by regulating TRA and chemokine expression in mTEClow for efficient induction of central tolerance. PMID:18390720

  20. System modeling of an air-independent solid oxide fuel cell system for unmanned undersea vehicles

    Science.gov (United States)

    Burke, A. Alan; Carreiro, Louis G.

    To examine the feasibility of a solid oxide fuel cell (SOFC)-powered unmanned undersea vehicle (UUV), a system level analysis is presented that projects a possible integration of the SOFC stack, fuel steam reformer, fuel/oxidant storage and balance of plant components into a 21-in. diameter UUV platform. Heavy hydrocarbon fuel (dodecane) and liquid oxygen (LOX) are chosen as the preferred reactants. A maximum efficiency of 45% based on the lower heating value of dodecane was calculated for a system that provides 2.5 kW for 40 h. Heat sources and sinks have been coupled to show viable means of thermal management. The critical design issues involve proper recycling of exhaust steam from the fuel cell back into the reformer and effective use of the SOFC stack radiant heat for steam reformation of the hydrocarbon fuel.

  1. Evaluation of an air-liquid interface cell culture model for studies on the inflammatory and cytotoxic responses to tobacco smoke aerosols.

    Science.gov (United States)

    Azzopardi, David; Haswell, Linsey E; Foss-Smith, Geoff; Hewitt, Katherine; Asquith, Nathan; Corke, Sarah; Phillips, Gary

    2015-10-01

    In vitro toxicological studies for tobacco product assessment have traditionally been undertaken using the particulate phase of tobacco smoke. However, this does not truly reflect exposure conditions that occur in smokers. Thus in vitro cell culture systems are required in which cells are exposed to tobacco whole smoke (WS) at the air-liquid interface (ALI). In this study bronchial epithelial cells were cultured on semi-permeable membranes, transitioned to the ALI and the robustness and sensitivity of the cells to tobacco WS and vapour phase (VP) assessed. Although no effect of air exposure was observed on cell viability, IL-6 and IL-8 release was increased. Exposure to WS resulted in a significant dose dependent decrease in cell viability and a significant non-dose dependent increase in inflammatory mediator secretion. The VP was found to contribute approximately 90% of the total cytotoxicity derived from WS. The cell culture system was also able to differentiate between two smoking regimens and was sensitive to passage number with increased inflammatory mediator secretion and lower cell viability observed in cell cultures of low passage number following WS exposure. This simple cell culture system may facilitate studies on the toxicological impact of future tobacco products and nicotine delivery devices. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Steam Methane Reformation Testing for Air-Independent Solid Oxide Fuel Cell Systems

    Science.gov (United States)

    Mwara, Kamwana N.

    2015-01-01

    Recently, NASA has been looking into utilizing landers that can be propelled by LOX-CH (sub 4), to be used for long duration missions. Using landers that utilize such propellants, also provides the opportunity to use solid oxide fuel cells as a power option, especially since they are able to process methane into a reactant through fuel reformation. One type of reformation, called steam methane reformation, is a process to reform methane into a hydrogen-rich product by reacting methane and steam (fuel cell exhaust) over a catalyst. A steam methane reformation system could potentially use the fuel cell's own exhaust to create a reactant stream that is hydrogen-rich, and requires less internal reforming of the incoming methane. Also, steam reformation may hold some advantages over other types of reforming, such as partial oxidation (PROX) reformation. Steam reformation does not require oxygen, while up to 25 percent can be lost in PROX reformation due to unusable CO (sub 2) reformation. NASA's Johnson Space Center has conducted various phases of steam methane reformation testing, as a viable solution for in-space reformation. This has included using two different types of catalysts, developing a custom reformer, and optimizing the test system to find the optimal performance parameters and operating conditions.

  3. Shelf life stability comparison in air for solution processed pristine PDPP3T polymer and doped spiro-OMeTAD as hole transport layer for perovskite solar cell

    Directory of Open Access Journals (Sweden)

    Ashish Dubey

    2016-06-01

    Full Text Available This data in brief includes forward and reverse scanned current density–voltage (J–V characteristics of perovskite solar cells with PDPP3T and spiro-OMeTAD as HTL, stability testing conditions of perovskite solar cell shelf life in air for both PDPP3T and spiro-OMeTAD as HTL as per the description in Ref. [1], and individual J–V performance parameters acquired with increasing time exposed in ambient air are shown for both type of devices using PDPP3T and spiro-OMeTAD as HTL. The data collected in this study compares the device stability with time for both PDPP3T and spiro-OMeTAD based perovskite solar cells and is directly related to our research article “solution processed pristine PDPP3T polymer as hole transport layer for efficient perovskite solar cells with slower degradation” [2].

  4. Toxicological characterization of size-segregated urban air particulate matter in macrophage cell line - effects of chemical composition and sources

    Energy Technology Data Exchange (ETDEWEB)

    Jalava, P.

    2008-07-01

    of the chemical mass closure method in the characterization of the gravimetrically measured, size-segregated particulate mass of the HVCI samples used in toxicological studies. These results and well-established chemical tracers were utilized in the identification of potentially harmful particulate sources. Inflammatory properties of the HVCI particulate samples were investigated in an immortalized mouse macrophage cell line (RAW264.7). They were assessed by measuring the production of proinflammatory cytokines (IL-6, TNFalpha) and chemokine (MIP-2) by macrophages exposed to the particulate samples. Nitric oxide production was also measured. Cell viability, apoptosis and the stage of the cell cycle of the macrophages were analyzed as indicators of cytotoxicity. Toxicity profiles of the samples collected during different air pollution situations in Helsinki varied extensively. The overall toxicity of the PM{sub 1-0.2} mass per cubic meter of air during transnational forest fire smoke episodes was estimated as being higher than the seasonal average in springtime. The particulate samples in PM{sub 10-2.5} size range were the most potent inducers of inflammation and cytotoxicity. However, the air pollution situation strongly affected the particle-induced responses in six European cities. There was more heterogeneity in the toxic responses in association with the PM{sub 2.5-0.2} than the PM{sub 10-2.5} samples. In both size ranges, the responses were mainly due to the insoluble fraction of the particulate samples with only minor effects by the water-soluble or organic solvent soluble fractions. The PM{sub 0.2} samples did not substantially increase cytokine production, but some samples exhibited cytotoxic and apoptotic activity. This suggests that the solubility and the chemical composition of the particulate material affect the toxic potency and that the material in different particulate size ranges can activate distinct biological mechanisms. There were a larger number

  5. Biofuel cell for generating power from methanol substrate using alcohol oxidase bioanode and air-breathed laccase biocathode.

    Science.gov (United States)

    Das, Madhuri; Barbora, Lepakshi; Das, Priyanki; Goswami, Pranab

    2014-09-15

    We report here an alcohol oxidase (AOx) based third generation bioanode for generating power from methanol substrate in a fuel cell setup using air breathed laccase biocathode. A composite three dimensional microporous matrix containing multiwalled carbon nanotubes, carbon paste and nafion was used as electroactive support for immobilization of the enzymes on toray carbon paper as supporting electrode in the fabrication of the bioelectrodes. Polyethylenimine was used to electrostatically stabilize the AOx (pI 4.3) on the anode operating on direct electrochemistry principle. Osmium tetroxide on poly (4-vinylpyridine) was used to wire the laccase for electron transfer in the biocathode. The enzymatic biofuel cell (EFC) generated an open circuit potential of 0.61 (±0.02) V with a maximum power density of 46 (±0.002) µW cm(-2) at an optimum of 1M methanol, 25 °C and an internal resistance of 0.024 µΩ. The operation and storage half life (t1/2) of the EFC were 17.22 h and 52 days, respectively at a fixed load of 1.85 Ω. The findings have demonstrated the feasibility of developing EFC using AOx based bioanode and laccase based biocathode without applying any toxic free mediator and metal electrode supports for generating electricity. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Wastewater treatment, energy recovery and desalination using a forward osmosis membrane in an air-cathode microbial osmotic fuel cell

    KAUST Repository

    Werner, Craig M.

    2013-02-01

    A microbial osmotic fuel cell (MOFC) has a forward osmosis (FO) membrane situated between the electrodes that enable desalinated water recovery along with power generation. Previous designs have required aerating the cathode chamber water, offsetting the benefits of power generation by power consumption for aeration. An air-cathode MOFC design was developed here to improve energy recovery, and the performance of this new design was compared to conventional microbial fuel cells containing a cation (CEM) or anion exchange membrane (AEM). Internal resistance of the MOFC was reduced with the FO membrane compared to the ion exchange membranes, resulting in a higher maximum power production (43W/m3) than that obtained with an AEM (40W/m3) or CEM (23W/m3). Acetate (carbon source) removal reached 90% in the MOFC; however, a small amount of acetate crossed the membrane to the catholyte. The initial water flux declined by 28% from cycle 1 to cycle 3 of operation but stabilized at 4.1L/m2/h over the final three batch cycles. This decline in water flux was due to membrane fouling. Overall desalination of the draw (synthetic seawater) solution was 35%. These results substantially improve the prospects for simultaneous wastewater treatment and seawater desalination in the same reactor. © 2012 Elsevier B.V.

  7. Flexible high power-per-weight perovskite solar cells with chromium oxide-metal contacts for improved stability in air.

    Science.gov (United States)

    Kaltenbrunner, Martin; Adam, Getachew; Głowacki, Eric Daniel; Drack, Michael; Schwödiauer, Reinhard; Leonat, Lucia; Apaydin, Dogukan Hazar; Groiss, Heiko; Scharber, Markus Clark; White, Matthew Schuette; Sariciftci, Niyazi Serdar; Bauer, Siegfried

    2015-10-01

    Photovoltaic technology requires light-absorbing materials that are highly efficient, lightweight, low cost and stable during operation. Organolead halide perovskites constitute a highly promising class of materials, but suffer limited stability under ambient conditions without heavy and costly encapsulation. Here, we report ultrathin (3 μm), highly flexible perovskite solar cells with stabilized 12% efficiency and a power-per-weight as high as 23 W g(-1). To facilitate air-stable operation, we introduce a chromium oxide-chromium interlayer that effectively protects the metal top contacts from reactions with the perovskite. The use of a transparent polymer electrode treated with dimethylsulphoxide as the bottom layer allows the deposition-from solution at low temperature-of pinhole-free perovskite films at high yield on arbitrary substrates, including thin plastic foils. These ultra-lightweight solar cells are successfully used to power aviation models. Potential future applications include unmanned aerial vehicles-from airplanes to quadcopters and weather balloons-for environmental and industrial monitoring, rescue and emergency response, and tactical security applications.

  8. Development of technique for air coating and nickel and copper metalization of solar cells

    Science.gov (United States)

    1982-01-01

    Solar cells were made with a variety of base metal screen printing inks applied over silicon nitride AR coating and copper electroplated. Fritted and fritless nickel and fritless tin base printing inks were evaluated. Conversion efficiencies as high as 9% were observed with fritted nickel ink contacts, however, curve shapes were generally poor, reflecting high series resistance. Problems encountered in addition to high series reistance included loss of adhesion of the nickel contacts during plating and poor adhesion, oxidation and inferior curve shapes with the tin base contacts.

  9. Efficient light incoupling into silicon thin-film solar cells by anti-reflecting MgO/high-compact-AZO with air-side textured glass

    International Nuclear Information System (INIS)

    Kang, Dong-Won; Han, Min-Koo; Lee, Heon-Min

    2013-01-01

    Light incoupling effects have been enhanced at front interfaces of silicon (Si) thin-film solar cells. Firstly, a MgO thin film was introduced at glass substrate/Al-doped ZnO (AZO) interface for anti-reflection effect. We additionally found that the surface morphology of AZO films grown on MgO film after texture-etching is dependent on the compactness of AZO. For high-compact AZO films, the texture-etched MgO/AZO double layer exhibited significantly enhanced light-scattering capability. Secondly, we made textured surfaces at air/glass interface through simple plasma-etching without sacrificial layers or masks by optimizing the etching pressure. The additional air-side texture contributed to further improvement of total light scattering from the MgO/AZO-coated glass substrate. Fabricated microcrystalline Si thin-film solar cells employing the MgO coated glass with air-side surface texture showed decreased cell reflectance and increased quantum efficiency. The J sc increased from 21.7 to 26.5 mA cm −2 and final efficiency of 9.49% was achieved. Based on our experimental results, the suggested structure, the MgO coating on glass substrate of which air-side surface is texture-etched, can offer a promising approach to improve the light incoupling and efficiency of Si thin-film solar cells. (paper)

  10. No oxidative stress or DNA damage in peripheral blood mononuclear cells after exposure to particles from urban street air in overweight elderly

    DEFF Research Database (Denmark)

    Hemmingsen, Jette Gjerke; Jantzen, Kim; Møller, Peter

    2015-01-01

    particle-filtered or sham-filtered air from a busy street with number of concentrations and PM2.5 levels of 1800/cm(3) versus 23 000/cm(3) and 3 µg/m(3) versus 24 µg/m(3), respectively. Peripheral blood mononuclear cells (PBMCs) were collected and assayed for production of ROS with and without ex vivo...

  11. Enhanced water desalination efficiency in an air-cathode stacked microbial electrodeionization cell (SMEDIC)

    KAUST Repository

    Chehab, Noura A.

    2014-11-01

    A microbial desalination cell was developed that contained a stack of membranes packed with ion exchange resins between the membranes to reduce ohmic resistances and improve performance. This new configuration, called a stacked microbial electro-deionization cell (SMEDIC), was compared to a control reactor (SMDC) lacking the resins. The SMEDIC+S reactors contained both a spacer and 1.4±0.2. mL of ion exchange resin (IER) per membrane channel, while the spacer was omitted in the SMEDIC-S reactors and so a larger volume of resin (2.4±0.2. mL) was used. The overall extent of desalination using the SMEDIC with a moderate (brackish water) salt concentration (13. g/L) was 90-94%, compared to only 60% for the SMDC after 7 fed-batch cycles of the anode. At a higher (seawater) salt concentration of 35. g/L, the extent of desalination reached 61-72% (after 10 cycles) for the SMEDIC, compared to 43% for the SMDC. The improved performance was shown to be due to the reduction in ohmic resistances, which were 130. Ω (SMEDIC-S) and 180. Ω (SMEDIC+S) at the high salt concentration, compared to 210. Ω without resin (SMDC). These results show that IERs can improve performance of stacked membranes for both moderate and high initial salt concentrations. © 2014 Elsevier B.V.

  12. Water recovery and air humidification by condensing the moisture in the outlet gas of a proton exchange membrane fuel cell stack

    International Nuclear Information System (INIS)

    Wan, Z.M.; Wan, J.H.; Liu, J.; Tu, Z.K.; Pan, M.; Liu, Z.C.; Liu, W.

    2012-01-01

    Humidification is one of the most important factors for the operation of proton exchange membrane fuel cell (PEMFC). To maintain the membrane at hydrated state, plenty of water is needed for the state-of-the-art of PEMFC technology, especially in large power applications or long time operation. A condenser is introduced to separate liquid water from the air outlet for air self-sufficient in water of the stack in this study. The condensed temperature at the outlet of the condenser and water recovered amount for air self-sufficient in water are investigated theoretically and experimentally. It is shown that the condensed temperature for air self-sufficient in water is irrelevant with the working current of the stack. When the condenser outlet temperature was above the theoretical line, recovery water was not sufficient for the air humidification. On the contrary, it is sufficient while the temperature was below the theoretical line. It is also shown that when the moisture is sufficiently cooled, large amount water can be separated from the outlet gas, and it increased almost linearly with the time. With the introduction of the condenser, the recovered amount of water can easily satisfy the air self-sufficient in water by condensing the outlet gas to a proper temperature. - Highlights: ► We introduce a condenser to separate liquid water from the air outlet in the stack. ► The mechanism of air self-sufficient in water by condensing gas is presented. ► The condensed temperature and water recovered amount are investigated. ► An experiment is present to validate simplicity and feasibility of the criterion. ► The criterion for air humidification is used for choosing the condenser.

  13. Air Research

    Science.gov (United States)

    EPA's air research provides the critical science to develop and implement outdoor air regulations under the Clean Air Act and puts new tools and information in the hands of air quality managers and regulators to protect the air we breathe.

  14. Internal short circuit and accelerated rate calorimetry tests of lithium-ion cells: Considerations for methane-air intrinsic safety and explosion proof/flameproof protection methods.

    Science.gov (United States)

    Dubaniewicz, Thomas H; DuCarme, Joseph P

    2016-09-01

    Researchers with the National Institute for Occupational Safety and Health (NIOSH) studied the potential for lithium-ion cell thermal runaway from an internal short circuit in equipment for use in underground coal mines. In this third phase of the study, researchers compared plastic wedge crush-induced internal short circuit tests of selected lithium-ion cells within methane (CH 4 )-air mixtures with accelerated rate calorimetry tests of similar cells. Plastic wedge crush test results with metal oxide lithium-ion cells extracted from intrinsically safe evaluated equipment were mixed, with one cell model igniting the chamber atmosphere while another cell model did not. The two cells models exhibited different internal short circuit behaviors. A lithium iron phosphate (LiFePO 4 ) cell model was tolerant to crush-induced internal short circuits within CH 4 -air, tested under manufacturer recommended charging conditions. Accelerating rate calorimetry tests with similar cells within a nitrogen purged 353-mL chamber produced ignitions that exceeded explosion proof and flameproof enclosure minimum internal pressure design criteria. Ignition pressures within a 20-L chamber with 6.5% CH 4 -air were relatively low, with much larger head space volume and less adiabatic test conditions. The literature indicates that sizeable lithium thionyl chloride (LiSOCl 2 ) primary (non rechargeable) cell ignitions can be especially violent and toxic. Because ignition of an explosive atmosphere is expected within explosion proof or flameproof enclosures, there is a need to consider the potential for an internal explosive atmosphere ignition in combination with a lithium or lithium-ion battery thermal runaway process, and the resulting effects on the enclosure.

  15. Air system in the hot cell for injectable radiopharmaceutical production: requirements for personnel and environment safety and protection of the product

    International Nuclear Information System (INIS)

    Campos, Fabio E.; Araujo, Elaine B.

    2009-01-01

    Radiopharmaceuticals are applied in Nuclear Medicine in diagnostic and therapeutic procedures and must be manufactured in accordance with the basic principles of Good Manufacturing Practices (GMP) for sterile pharmaceutical products. In order to prevent the uncontrolled spread of radioactive contamination, the processing of radioactive materials requires an exhausted and shielded special enclosure called hot cell. The quality of air inside the hot cell must be controlled in order to prevent the contamination of the product with particulate material or microorganisms. On the other hand, the hot cell must prevent external contamination with radioactive material. The aim of this work is to discuss the special requirements for hot cells taking in account the national rules for injectable pharmaceutical products and international standards available. Ventilation of radiopharmaceutical production facilities should meet the requirement to prevent the contamination of products and the exposure of working personnel to radioactivity. Positive pressure areas should be used to process sterile products. In general, any radioactivity should handle within specifically designed areas maintained under negative pressures. The production of sterile radioactive products should therefore be carried out under negative pressure surrounded by a positive pressure zone ensuring that appropriate air quality requirements are met. Some of the recent developments in the use of radioisotopes in medical field have also significantly impacted on the evolution of handling facilities. Application of pharmaceutical GMP requirements for air quality and processing conditions in the handling facilities of radioactive pharmaceuticals has led to significant improvements in the construction of isolator-like hot cells and clean rooms with HEPA filtered ventilation and air conditioning (HVAC) systems. Clean grade A (class 100) air quality hot cells are now available commercially, but in a high cost

  16. Large scale deployment of polymer solar cells on land, on sea and in the air

    DEFF Research Database (Denmark)

    Espinosa Martinez, Nieves; Hösel, Markus; Jørgensen, Mikkel

    2014-01-01

    key parameters in order to assess their environmental impact. The novel technology when installed in a solar park system can generate more than 1300 kW h kWp-1 of electricity a year, which means that the whole system can pay the energy invested back before the first year of operation, in 320 days......With the development of patterns that connect all cells in series, organic photovoltaics have leapt a step forward being ahead of other solar and even other energy technologies in terms of manufacturing speed and energy density. The important questions of how they are meant to be installed....... If this electricity is fed back to the same electricity supply system that was used for manufacturing the potential saving of more than 13 GJ of primary energy per kWp per year can be reached. With the real data logged, a dynamic energy payback time has been furthermore calculated for the case of the solar tube...

  17. Performance of direct ethanol fuel cells as function of using of compressed air; Desempenho de celulas a combustivel com alimentacao direta de etanol em funcao do uso de ar comprimido

    Energy Technology Data Exchange (ETDEWEB)

    Belchor, P.M. [UFRGS - Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Berns, B.A.; Ferreira, R.C.; Goldbach, A.; Carpenter, D. [FURB - Fundacao Universidade Regional de Blumenau, Blumenau, SC (Brazil)

    2010-07-01

    This paper compared the performance of a direct ethanol fuel cell (CCADE) cathode feeding with air replacing the pure oxygen. The results have shown that the small decreasing of the yield of the cell under both practical and experimental situations, by the use of air replacing pure oxygen, it completely acceptable as function of great diminishing of operational costs. (author)

  18. An isopropanol-assisted fabrication strategy of pinhole-free perovskite films in air for efficient and stable planar perovskite solar cells

    Science.gov (United States)

    Ren, Ziqiu; Zhu, Menghua; Li, Xin; Dong, Cunku

    2017-09-01

    As a promising photovoltaic device, perovskite solar cells have attracted numerous attention in recent years, where forming a compact and pinhole-free perovskite film in air is of great importance. Herein, we evaluate highly efficient and air stable planar perovskite solar cells in air (relative humidity over 50%) with the modified two-step sequential deposition method by adjusting the CH3NH3I (MAI) concentrations and regulating the crystallization process of the perovskite film. The optimum MAI concentration is 60 mg mL-1 in isopropanol. With a planar structure of FTO/TiO2/MAPbI3/spiro-OMeTAD/Au, the efficient devices composed of compact and pinhole-free perovskite films are constructed in air, achieving a high efficiency of up to 15.10% and maintaining over 80% after 20 days storing without any encapsulation in air. With a facile fabrication process and high photovoltaic performance, this work represents a promising method for fabricating low-cost, highly efficient and stable photovoltaic device.

  19. A novel approach to regulate cell membrane permeability for ATP and NADH formation in Saccharomyces cerevisiae induced by air cold plasma

    Science.gov (United States)

    Dong, Xiaoyu; Liu, Tingting; Xiong, Yuqin

    2017-02-01

    Air cold plasma has been used as a novel method for enhancing microbial fermentation. The aim of this work was to explore the effect of plasma on membrane permeability and the formation of ATP and NADH in Saccharomyces cerevisiae, so as to provide valuable information for large-scale application of plasma in the fermentation industry. Suspensions of S. cerevisiae cells were exposed to air cold plasma for 0, 1, 2, 3, 4 and 5 min, and then subjected to various analyses prior to fermentation (0 h) and at the 9 and 21 h stages of fermentation. Compared with non-exposed cells, cells exposed to plasma for 1 min exhibited a marked increase in cytoplasmic free Ca2+ concentration as a result of the significant increase in membrane potential prior to fermentation. At the same time, the ATP level in the cell suspension decreased by about 40%, resulting in a reduction of about 60% in NADH prior to culturing. However, the levels of ATP and NADH in the culture at the 9 and 21 h fermentation stages were different from the level at 0 h. Taken together, the results indicated that exposure of S. cerevisiae to air cold plasma could increase its cytoplasmic free Ca2+ concentration by improving the cell membrane potential, consequently leading to changes in ATP and NADH levels. Supported by National Natural Science Foundation of China (Nos. 21246012, 21306015 and 21476032).

  20. Electrochemical analysis of separators used in single-chamber, air-cathode microbial fuel cells

    KAUST Repository

    Wei, Bin

    2013-02-01

    Polarization, solution-separator, charge transfer, and diffusion resistances of clean and used separator electrode assemblies were examined in microbial fuel cells using current-voltage curves and electrochemical impedance spectroscopy (EIS). Current-voltage curves showed the total resistance was reduced at low cathode potentials. EIS results revealed that at a set cathode potential of 0.3 V diffusion resistance was predominant, and it substantially increased when adding separators. However, at a lower cathode potential of 0.1 V all resistances showed only slight differences with and without separators. Used separator electrode assemblies with biofilms had increased charge transfer and diffusion resistances (0.1 V) when one separator was used; however, charge transfer resistance increased, and diffusion resistance did not appreciably change with four separators. Adding a plastic mesh to compress the separators improved maximum power densities. These results show the importance of pressing separators against the cathode, and the adverse impacts of biofilm formation on electrochemical performance. © 2012 Elsevier Ltd. All Rights Reserved.

  1. Electricity generation using white and red wine lees in air cathode microbial fuel cells

    Science.gov (United States)

    Pepe Sciarria, Tommy; Merlino, Giuseppe; Scaglia, Barbara; D'Epifanio, Alessandra; Mecheri, Barbara; Borin, Sara; Licoccia, Silvia; Adani, Fabrizio

    2015-01-01

    Microbial fuel cell (MFC) is a useful biotechnology to produce electrical energy from different organic substrates. This work reports for the first time results of the application of single chamber MFCs to generate electrical energy from diluted white wine (WWL) and red wine (RWL) lees. Power obtained was of 8.2 W m-3 (262 mW m-2; 500 Ω) and of 3.1 W m-3 (111 mW m-2; 500Ω) using white and red wine lees, respectively. Biological processes lead to a reduction of chemical oxygen (TCOD) and biological oxygen demand (BOD5) of 27% and 83% for RWL and of 90% and 95% for WWL, respectively. These results depended on the degradability of organic compounds contained, as suggest by BOD5/TCOD of WWL (0.93) vs BOD5/TCOD of RWL (0.33), and to the high presence of polyphenols in RWL that inhibited the process. Coulombic efficiency (CE) of 15 ± 0%, for WWL, was in line with those reported in the literature for other substrates, i.e. CE of 14.9 ± 11.3%. Different substrates led to different microbial consortia, particularly at the anode. Bacterial species responsible for the generation of electricity, were physically connected to the electrode, where the direct electron transfer took place.

  2. Increasing power generation for scaling up single-chamber air cathode microbial fuel cells

    KAUST Repository

    Cheng, Shaoan

    2011-03-01

    Scaling up microbial fuel cells (MFCs) requires a better understanding the importance of the different factors such as electrode surface area and reactor geometry relative to solution conditions such as conductivity and substrate concentration. It is shown here that the substrate concentration has significant effect on anode but not cathode performance, while the solution conductivity has a significant effect on the cathode but not the anode. The cathode surface area is always important for increasing power. Doubling the cathode size can increase power by 62% with domestic wastewater, but doubling the anode size increases power by 12%. Volumetric power density was shown to be a linear function of cathode specific surface area (ratio of cathode surface area to reactor volume), but the impact of cathode size on power generation depended on the substrate strength (COD) and conductivity. These results demonstrate the cathode specific surface area is the most critical factor for scaling-up MFCs to obtain high power densities. © 2010 Elsevier Ltd.

  3. Paper-Based Analytical Devices Relying on Visible-Light-Enhanced Glucose/Air Biofuel Cells.

    Science.gov (United States)

    Wu, Kaiqing; Zhang, Yan; Wang, Yanhu; Ge, Shenguang; Yan, Mei; Yu, Jinghua; Song, Xianrang

    2015-11-04

    A strategy that combines visible-light-enhanced biofuel cells (BFCs) and electrochemical immunosensor into paper-based analytical devices was proposed for sensitive detection of the carbohydrate antigen 15-3 (CA15-3). The gold nanoparticle modified paper electrode with large surface area and good conductibility was applied as an effective matrix for primary antibodies. The glucose dehydrogenase (GDH) modified gold-silver bimetallic nanoparticles were used as bioanodic biocatalyst and signal magnification label. Poly(terthiophene) (pTTh), a photoresponsive conducting polymer, served as catalyst in cathode for the reduction of oxygen upon illumination by visible light. In the bioanode, electrons were generated through the oxidation of glucose catalyzed by GDH. The amount of electrons is determined by the amount of GDH, which finally depended on the amount of CA15-3. In the cathode, electrons from the bioanode could combine with the generated holes in the HOMO energy level of cathode catalysts pTTh. Meanwhile, the high energy level photoexcited electrons were generated in the LUMO energy level and involved in the oxygen reduction reaction, finally resulting in an increasing current and a decreasing overpotential. According to the current signal, simple and efficient detection of CA15-3 was achieved.

  4. The Injection of Air/Oxygen Bubble into the Anterior Chamber of Rabbits as a Treatment for Hyphema in Patients with Sickle Cell Disease

    Directory of Open Access Journals (Sweden)

    Emre Ayintap

    2014-01-01

    Full Text Available Purpose. To investigate the changes of partial oxygen pressure (PaO2 in aqueous humour after injecting air or oxygen bubble into the anterior chamber in sickle cell hyphema. Methods. Blood samples were taken from the same patient with sickle cell disease. Thirty-two rabbits were divided into 4 groups. In group 1 (n=8, there was no injection. Only blood injection constituted group 2 (n=8, both blood and air bubble injection constituted group 3 (n=8, and both blood and oxygen bubble injection constituted group 4 (n=8. Results. The PaO2 in the aqueous humour after 10 hours from the injections was 78.45 ± 9.9 mmHg (Mean ± SD for group 1, 73.97 ± 8.86 mmHg for group 2, 123.35 ± 13.6 mmHg for group 3, and 306.47 ± 16.5 mmHg for group 4. There was statistically significant difference between group 1 and group 2, when compared with group 3 and group 4. Conclusions. PaO2 in aqueous humour was increased after injecting air or oxygen bubble into the anterior chamber. We offer to leave an air bubble in the anterior chamber of patients with sickle cell hemoglobinopathies and hyphema undergoing an anterior chamber washout.

  5. Thymic epithelial cell-specific deletion of Jmjd6 reduces Aire protein expression and exacerbates disease development in a mouse model of autoimmune diabetes.

    Science.gov (United States)

    Yanagihara, Toyoshi; Tomino, Takahiro; Uruno, Takehito; Fukui, Yoshinori

    2017-07-15

    Thymic epithelial cells (TECs) establish spatially distinct microenvironments in which developing T cells are selected to mature or die. A unique property of medullary TECs is their expression of thousands of tissue-restricted self-antigens that is largely under the control of the transcriptional regulator Aire. We previously showed that Jmjd6, a lysyl hydroxylase for splicing regulatory proteins, is important for Aire protein expression and that transplantation of Jmjd6-deficient thymic stroma into athymic nude mice resulted in multiorgan autoimmunity. Here we report that TEC-specific deletion of Jmjd6 exacerbates development of autoimmune diabetes in a mouse model, which express both ovalbumin (OVA) under the control of the rat insulin gene promoter and OT-I T cell receptor specific for OVA peptide bound to major histocompatibility complex class I K b molecules. We found that Aire protein expression in mTECs was reduced in the absence of Jmjd6, with retention of intron 2 in Aire transcripts. Our results thus demonstrate the importance of Jmjd6 in establishment of immunological tolerance in a more physiological setting. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Oxidative stress and DNA damage caused by the urban air pollutant 3-NBA and its isomer 2-NBA in human lung cells analyzed with three independent methods.

    OpenAIRE

    Nagy, Eszter; Johansson, Clara; Zeisig, Magnus; Moller, Lennart

    2005-01-01

    The air pollutant 3-nitrobenzanthrone (3-NBA), emitted in diesel exhaust, is a potent mutagen and genotoxin. 3-NBA can isomerise to 2-nitrobenzanthrone (2-NBA), which can become more than 70-fold higher in concentration in ambient air. In this study, three independent methods have been employed to evaluate the oxidative stress and genotoxicity of 2-NBA compared to 3-NBA in the human A549 lung cell line. HPLC-EC/UV was applied for measurements of oxidative damage in the form of 8-oxo-2'-deoxyg...

  7. Surpassing 10% Efficiency Benchmark for Nonfullerene Organic Solar Cells by Scalable Coating in Air from Single Nonhalogenated Solvent

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Long [Department of Physics, Organic and Carbon Electronics Lab (ORaCEL), North Carolina State University, Raleigh NC 27695 USA; Xiong, Yuan [Department of Physics, Organic and Carbon Electronics Lab (ORaCEL), North Carolina State University, Raleigh NC 27695 USA; Zhang, Qianqian [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill NC 27599 USA; Li, Sunsun [Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 P. R. China; Wang, Cheng [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley CA 94720 USA; Jiang, Zhang [Advanced Photon Source, Argonne National Laboratory, Argonne IL 60439 USA; Hou, Jianhui [Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 P. R. China; You, Wei [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill NC 27599 USA; Ade, Harald [Department of Physics, Organic and Carbon Electronics Lab (ORaCEL), North Carolina State University, Raleigh NC 27695 USA

    2018-01-10

    The commercialization of nonfullerene organic solar cells (OSCs) relies critically on the response under typical operating conditions (for instance, temperature, humidity) and the ability of scale-up. Despite the rapid increase in power conversion efficiency (PCE) of spin-coated devices fabricated in a protective atmosphere, the device efficiencies of printed nonfullerene OSC devices by blade-coating are still lower than 6%. This slow progress significantly limits the practical printing of high-performance nonfullerene OSCs. Here, a new and stable nonfullerene combination was introduced by pairing a commercially available nonfluorinated acceptor IT-M with the polymeric donor FTAZ. Over 12%-efficiency can be achieved in spincoated FTAZ:IT-M devices using a single halogen-free solvent. More importantly, chlorinefree, in air blade-coating of FTAZ:IT-M is able to yield a PCE of nearly 11%, despite a humidity of ~50%. X-ray scattering results reveal that large π-π coherence lengths, high degree of faceon orientation with respect to the substrate, and small domain spacings of ~20 nm are closely correlated with such high device performance. Our material system and approach yields the highest reported performance for nonfullerene OSC devices by a coating technique approximating scalable fabrication methods and holds great promise for the development of low-cost, low-toxicity, and high-efficiency OSCs by high-throughput production.

  8. Performance of low cost scalable air-cathode microbial fuel cell made from clayware separator using multiple electrodes.

    Science.gov (United States)

    Ghadge, Anil N; Ghangrekar, Makarand M

    2015-04-01

    Performance of scalable air-cathode microbial fuel cell (MFC) of 26 L volume, made from clayware cylinder with multiple electrodes, was evaluated. When electrodes were connected in parallel with 100 Ω resistance (R ext), power of 11.46 mW was produced which was 4.48 and 3.73 times higher than individual electrode pair and series connection, respectively. Coulombic efficiency of 5.10 ± 0.13% and chemical oxygen demand (COD) removal of 78.8 ± 5.52% was observed at R ext of 3 Ω. Performance under different organic loading rates (OLRs) varying from 0.75 to 6.0 g CODL(-1)d(-1) revealed power of 17.85 mW (47.28 mA current) at OLR of 3.0 g CODL(-1)d(-1). Internal resistance (R int) of 5.2 Ω observed is among the least value reported in literature. Long term operational stability (14 months) demonstrates the technical viability of clayware MFC for practical applications and potential benefits towards wastewater treatment and electricity recovery. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. A novel microbial fuel cell sensor with a gas diffusion biocathode sensing element for water and air quality monitoring.

    Science.gov (United States)

    Jiang, Yong; Liang, Peng; Huang, Xia; Ren, Zhiyong Jason

    2018-03-26

    Toxicity monitoring is essential for the protection of public health and ecological safety. Microbial fuel cell (MFC) sensors demonstrated good potential in toxicity monitoring, but current MFC sensors can only be used for anaerobic water monitoring. In this study, a novel gas diffusion (GD)-biocathode sensing element was fabricated using a simple method. The GD-biocathode MFC sensor can directly be used for formaldehyde detection (from 0.0005% to 0.005%) in both aerobic and anaerobic water bodies. Electrochemical analysis indicated that the response by the sensor was caused by the toxic inhibition to the microbial activity for the oxygen reduction reaction (ORR). This study for the first time demonstrated that the GD-biocathode MFC sensor has a detection limit of 20 ppm for formaldehyde and can be used to monitor air pollution. Selective sensitivity to formaldehyde was not achieved as the result of using a mixed-culture, which confirms that it can serve as a generic biosensor for monitoring gaseous pollutants. This study expands the realm of knowledge for MFC sensor applications. Copyright © 2018. Published by Elsevier Ltd.

  10. Catalysis kinetics and porous analysis of rolling activated carbon-PTFE air-cathode in microbial fuel cells.

    Science.gov (United States)

    Dong, Heng; Yu, Hongbing; Wang, Xin

    2012-12-04

    The microbial fuel cell (MFC), being an environment-friendly technology for wastewater treatment, is limited by low efficiency and high cost. Power output based on capital cost had been greatly increased in our previous work by introducing a novel activated carbon (AC) air-cathode (ACAC). The catalysis behavior of this ACAC was studied here based on catalysis kinetics and pore analysis of both carbon powders and catalyst layers (CLs). Plain AC (AC1#), ultracapacitor AC (AC2#), and non-AC (XC-72) powders were used as catalysts. The electron transfer number (n) of oxygen reduction reaction (ORR) with CLs increased by 5-23% compared to those n values of corresponding carbon powders before being rolled to CLs with PTFE, while the n value of Pt/C decreased by 38% when it was brushed with Nafion as the CL, indicating that rolling procedure with PTFE binder substantially increased the catalytic activity of carbon catalysts. Two-four times larger in micropore area of AC powders than non-AC powder resulted in 1.3-1.9 times increase in power density of MFCs. In addition, more uniform distribution of microporosity was found in AC1# than in AC2#, which could be the reason for the 25% increase in power density of ACAC1# (1355 ± 26 mW·m(-2)) compared to 1086 ± 8 mW·m(-2) of ACAC2#.

  11. Bio-electrochemical characterization of air-cathode microbial fuel cells with microporous polyethylene/silica membrane as separator.

    Science.gov (United States)

    Kircheva, Nina; Outin, Jonathan; Perrier, Gérard; Ramousse, Julien; Merlin, Gérard; Lyautey, Emilie

    2015-12-01

    The aim of this work was to study the behavior over time of a separator made of a low-cost and non-selective microporous polyethylene membrane (RhinoHide®) in an air-cathode microbial fuel cell with a reticulated vitreous carbon foam bioanode. Performances of the microporous polyethylene membrane (RhinoHide®) were compared with Nafion®-117 as a cationic exchange membrane. A non-parametric test (Mann-Whitney) done on the different sets of coulombic or energy efficiency data showed no significant difference between the two types of tested membrane (p<0.05). Volumetric power densities were ranging from 30 to 90 W·m(-3) of RVC foam for both membranes. Similar amounts of biomass were observed on both sides of the polyethylene membrane illustrating bacterial permeability of this type of separator. A monospecific denitrifying population on cathodic side of RhinoHide® membrane has been identified. Electrochemical impedance spectroscopy (EIS) was used at OCV conditions to characterize electrochemical behavior of MFCs by equivalent electrical circuit fitted on both Nyquist and Bode plots. Resistances and pseudo-capacitances from EIS analyses do not differ in such a way that the nature of the membrane could be considered as responsible. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Design, fabrication and testing of an air-breathing micro direct methanol fuel cell with compound anode flow field

    Science.gov (United States)

    Wang, Luwen; Zhang, Yufeng; Zhao, Youran; An, Zijiang; Zhou, Zhiping; Liu, Xiaowei

    2011-10-01

    An air-breathing micro direct methanol fuel cell (μDMFC) with a compound anode flow field structure (composed of the parallel flow field and the perforated flow field) is designed, fabricated and tested. To better analyze the effect of the compound anode flow field on the mass transfer of methanol, the compound flow field with different open ratios (ratio of exposure area to total area) and thicknesses of current collectors is modeled and simulated. Micro process technologies are employed to fabricate the end plates and current collectors. The performances of the μDMFC with a compound anode flow field are measured under various operating parameters. Both the modeled and the experimental results show that, comparing the conventional parallel flow field, the compound one can enhance the mass transfer resistance of methanol from the flow field to the anode diffusion layer. The results also indicate that the μDMFC with an anode open ratio of 40% and a thickness of 300 µm has the optimal performance under the 7 M methanol which is three to four times higher than conventional flow fields. Finally, a 2 h stability test of the μDMFC is performed with a methanol concentration of 7 M and a flow velocity of 0.1 ml min-1. The results indicate that the μDMFC can work steadily with high methanol concentration.

  13. Using ammonium bicarbonate as pore former in activated carbon catalyst layer to enhance performance of air cathode microbial fuel cell

    Science.gov (United States)

    Li, Da; Qu, Youpeng; Liu, Jia; He, Weihua; Wang, Haiman; Feng, Yujie

    2014-12-01

    The rolling catalyst layers in air cathode microbial fuel cells (MFCs) are prepared by introducing NH4HCO3 as pore former (PF) with four PF/activated carbon mass ratios of 0.1, 0.2, 0.3 and 1.0. The maximum power density of 892 ± 8 mW m-2 is obtained by cathodes with the mass ratio of 0.2, which is 33% higher than that of the control reactor (without PF, 671 ± 22 mW m-2). Pore analysis indicates the porosity increases by 38% and the major pore range concentrates between 0.5 μm-0.8 μm which likely facilitates to enrich the active reaction sites compared to 0.8 μm-3.0 μm in the control and other PF-cathodes. In addition, pore structure endows the cathode improved exchange current density by 2.4 times and decreased charge transfer resistance by 44%, which are the essential reasons to enhance the oxygen reduction. These results show that addition of NH4HCO3 proves an effective way to change the porosity and pore distribution of catalyst layers and then enhance the MFC performance.

  14. Self-Driven Desalination and Advanced Treatment of Wastewater in a Modularized Filtration Air Cathode Microbial Desalination Cell.

    Science.gov (United States)

    Zuo, Kuichang; Wang, Zhen; Chen, Xi; Zhang, Xiaoyuan; Zuo, Jiaolan; Liang, Peng; Huang, Xia

    2016-07-05

    Microbial desalination cells (MDCs) extract organic energy from wastewater for in situ desalination of saline water. However, to desalinate salt water, traditional MDCs often require an anolyte (wastewater) and a catholyte (other synthetic water) to produce electricity. Correspondingly, the traditional MDCs also produced anode effluent and cathode effluent, and may produce a concentrate solution, resulting in a low production of diluate. In this study, nitrogen-doped carbon nanotube membranes and Pt carbon cloths were utilized as filtration material and cathode to fabricate a modularized filtration air cathode MDC (F-MDC). With real wastewater flowing from anode to cathode, and finally to the middle membrane stack, the diluate volume production reached 82.4%, with the removal efficiency of salinity and chemical oxygen demand (COD) reached 93.6% and 97.3% respectively. The final diluate conductivity was 68 ± 12 μS/cm, and the turbidity was 0.41 NTU, which were sufficient for boiler supplementary or industrial cooling. The concentrate production was only 17.6%, and almost all the phosphorus and salt, and most of the nitrogen were recovered, potentially allowing the recovery of nutrients and other chemicals. These results show the potential utility of the modularized F-MDC in the application of municipal wastewater advanced treatment and self-driven desalination.

  15. Long-term performance of activated carbon air cathodes with different diffusion layer porosities in microbial fuel cells

    KAUST Repository

    Zhang, Fang

    2011-08-01

    Activated carbon (AC) air-cathodes are inexpensive and useful alternatives to Pt-catalyzed electrodes in microbial fuel cells (MFCs), but information is needed on their long-term stability for oxygen reduction. AC cathodes were constructed with diffusion layers (DLs) with two different porosities (30% and 70%) to evaluate the effects of increased oxygen transfer on power. The 70% DL cathode initially produced a maximum power density of 1214±123mW/m 2 (cathode projected surface area; 35±4W/m 3 based on liquid volume), but it decreased by 40% after 1 year to 734±18mW/m 2. The 30% DL cathode initially produced less power than the 70% DL cathode, but it only decreased by 22% after 1 year (from 1014±2mW/m 2 to 789±68mW/m 2). Electrochemical tests were used to examine the reasons for the degraded performance. Diffusion resistance in the cathode was found to be the primary component of the internal resistance, and it increased over time. Replacing the cathode after 1 year completely restored the original power densities. These results suggest that the degradation in cathode performance was due to clogging of the AC micropores. These findings show that AC is a cost-effective material for oxygen reduction that can still produce ~750mW/m 2 after 1 year. © 2011 Elsevier B.V.

  16. Long-Term Performance of Chemically and Physically Modified Activated Carbons in Air Cathodes of Microbial Fuel Cells

    KAUST Repository

    Zhang, Xiaoyuan

    2014-07-31

    © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Activated carbon (AC) is a low-cost and effective catalyst for oxygen reduction in air cathodes of microbial fuel cells (MFCs), but its performance must be maintained over time. AC was modified by three methods: 1)pyrolysis with iron ethylenediaminetetraacetic acid (AC-Fe), 2)heat treatment (AC-heat), and 3)mixing with carbon black (AC-CB). The maximum power densities after one month with these AC cathodes were 35% higher with AC-Fe (1410±50mW m-2) and AC-heat (1400±20mW m-2), and 16% higher with AC-CB (1210±30mW m-2) than for plain AC (1040±20mW m-2), versus 1270±50mW m-2 for a Pt control. After 16months, the Pt cathodes produced only 250±10mW m-2. However, the AC-heat and AC-CB cathodes still produced 960-970mW m-2, whereas plain AC produced 860±60mW m-2. The performance of the AC cathodes was restored to >85% of the initial maximum power densities by cleaning with a weak acid solution. Based on cost considerations among the AC materials, AC-CB appears to be the best choice for long-term performance.

  17. Surpassing 10% Efficiency Benchmark for Nonfullerene Organic Solar Cells by Scalable Coating in Air from Single Nonhalogenated Solvent.

    Science.gov (United States)

    Ye, Long; Xiong, Yuan; Zhang, Qianqian; Li, Sunsun; Wang, Cheng; Jiang, Zhang; Hou, Jianhui; You, Wei; Ade, Harald

    2018-02-01

    The commercialization of nonfullerene organic solar cells (OSCs) critically relies on the response under typical operating conditions (for instance, temperature and humidity) and the ability of scale-up. Despite the rapid increase in power conversion efficiency (PCE) of spin-coated devices fabricated in a protective atmosphere, the efficiencies of printed nonfullerene OSC devices by blade coating are still lower than 6%. This slow progress significantly limits the practical printing of high-performance nonfullerene OSCs. Here, a new and relatively stable nonfullerene combination is introduced by pairing the nonfluorinated acceptor IT-M with the polymeric donor FTAZ. Over 12% efficiency can be achieved in spin-coated FTAZ:IT-M devices using a single halogen-free solvent. More importantly, chlorine-free, blade coating of FTAZ:IT-M in air is able to yield a PCE of nearly 11% despite a humidity of ≈50%. X-ray scattering results reveal that large π-π coherence length, high degree of face-on orientation with respect to the substrate, and small domain spacing of ≈20 nm are closely correlated with such high device performance. The material system and approach yield the highest reported performance for nonfullerene OSC devices by a coating technique approximating scalable fabrication methods and hold great promise for the development of low-cost, low-toxicity, and high-efficiency OSCs by high-throughput production. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Air Pollution

    Science.gov (United States)

    Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, dust, pollen and ... Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, ...

  19. Radioactive Mapping Contaminant of Alpha on The Air in Space of Repair of Hot Cell and Medium Radioactivity Laboratory in Radio metallurgy Installation

    International Nuclear Information System (INIS)

    Yusuf-Nampira; Endang-Sukesi; S-Wahyuningsih; R-Budi-Santoso

    2007-01-01

    Hot cell and space of acid laboratory medium activity in Radio metallurgy Installation are used for the examination preparation of fuel nuclear post irradiation. The sample examined is dangerous radioactive material representing which can disseminate passing air stream. The dangerous material spreading can be pursued by arranging air stream from laboratory space to examination space. To know the performance the air stream arrangement is hence conducted by radioactive mapping contaminant of alpha in laboratory / space of activity place, for example, medium activity laboratory and repair space. This mapping radioactivity contaminant is executed with the measurement level of the radioactivity from sample air taken at various height with the distance of 1 m, various distance and from potential source as contaminant spreading access. The mapping result indicate that a little spreading of radioactive material happened from acid cupboard locker to laboratory activity up to distance of 3 m from acid cupboard locker and spreading of radioactive contaminant from goods access door of the hot cell 104 to repair space reach the distance of 2 m from goods door access. Level of the radioactive contamination in the space was far under maximum limitation allowed (20 Bq / m 3 ). (author)

  20. Simulation of an air conditioning absorption refrigeration system in a co-generation process combining a proton exchange membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Pilatowsky, I.; Gamboa, S.A.; Rivera, W. [Centro de Investigacion en Energia - UNAM, Temixco, Morelos (Mexico); Romero, R.J. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas - UAEM, Cuernavaca, Morelos (Mexico); Isaza, C.A. [Universidad Pontificia Bolivariana, Medellin (Colombia). Instituto de Energia y Termodinamica; Sebastian, P.J. [Centro de Investigacion en Energia - UNAM, Temixco, Morelos (Mexico); Cuerpo Academico de Energia y Sustentabilidad-UP Chiapas, Tuxtla Gutierrez, Chiapas (Mexico); Moreira, J. [Cuerpo Academico de Energia y Sustentabilidad-UP Chiapas, Tuxtla Gutierrez, Chiapas (Mexico)

    2007-10-15

    In this work, a computer simulation program was developed to determine the optimum operating conditions of an air conditioning system during the co-generation process. A 1 kW PEMFC was considered in this study with a chemical/electrical theoretical efficiency of 40% and a thermal efficiency of 30% applying an electrical load of 100%. A refrigeration-absorption cycle (RAC) operating with monomethylamine-water solutions (MMA-WS), with low vapor generation temperatures (up to 80 C) is proposed in this work. The computer simulation was based on the refrigeration production capacity at the maximum power capacity of the PEMFC. Heat losses between the fuel cell and the absorption air conditioning system at standard operating conditions were considered to be negligible. The results showed the feasibility of using PEMFC for cooling, increasing the total efficiency of the fuel cell system. (author)

  1. Nitrogen removal in a single-chamber microbial fuel cell with nitrifying biofilm enriched at the air cathode

    KAUST Repository

    Yan, Hengjing

    2012-05-01

    Nitrogen removal is needed in microbial fuel cells (MFCs) for the treatment of most waste streams. Current designs couple biological denitrification with side-stream or combined nitrification sustained by upstream or direct aeration, which negates some of the energy-saving benefits of MFC technology. To achieve simultaneous nitrification and denitrification, without extra energy input for aeration, the air cathode of a single-chamber MFC was pre-enriched with a nitrifying biofilm. Diethylamine-functionalized polymer (DEA) was used as the Pt catalyst binder on the cathode to improve the differential nitrifying biofilm establishment. With pre-enriched nitrifying biofilm, MFCs with the DEA binder had an ammonia removal efficiency of up to 96.8% and a maximum power density of 900 ± 25 mW/m 2, compared to 90.7% and 945 ± 42 mW/m 2 with a Nafion binder. A control with Nafion that lacked nitrifier pre-enrichment removed less ammonia and had lower power production (54.5% initially, 750 mW/m 2). The nitrifying biofilm MFCs had lower Coulombic efficiencies (up to 27%) than the control reactor (up to 36%). The maximum total nitrogen removal efficiency reached 93.9% for MFCs with the DEA binder. The DEA binder accelerated nitrifier biofilm enrichment on the cathode, and enhanced system stability. These results demonstrated that with proper cathode pre-enrichment it is possible to simultaneously remove organics and ammonia in a single-chamber MFC without supplemental aeration. © 2012 Elsevier Ltd.

  2. Stereolithographic biomodelling to create tangible hard copies of the ethmoidal labyrinth air cells based on the visible human project.

    Science.gov (United States)

    Kapakin, S

    2011-02-01

    Rapid prototyping (RP), or stereolithography, is a new clinical application area, which is used to obtain accurate three-dimensional physical replicas of complex anatomical structures. The aim of this study was to create tangible hard copies of the ethmoidal labyrinth air cells (ELACs) with stereolithographic biomodelling. The visible human dataset (VHD) was used as the input imaging data. The Surfdriver software package was applied to these images to reconstruct the ELACs as three-dimensional DXF (data exchange file) models. These models were post-processed in 3D-Doctor software for virtual reality modelling language (VRML) and STL (Standard Triangulation Language) formats. Stereolithographic replicas were manufactured in a rapid prototyping machine by using the STL format. The total number of ELACs was 21. The dimensions of the ELACs on the right and left sides were 52.91 x 13.00 x 28.68 mm and 53.79 x 12.42 x 28.55 mm, respectively. The total volume of the ELACs was 4771.1003 mm(3). The mean ELAC distance was 27.29 mm from the nasion and 71.09 mm from the calotte topologically. In conclusion, the combination of Surfdriver and 3D-Doctor could be effectively used for manufacturing 3D solid models from serial sections of anatomical structures. Stereolithographic anatomical models provide an innovative and complementary tool for students, researchers, and surgeons to apprehend these anatomical structures tangibly. The outcomes of these attempts can provide benefits in terms of the visualization, perception, and interpretation of the structures in anatomy teaching and prior to surgical interventions.

  3. Oxidative stress, DNA damage, and inflammation induced by ambient air and wood smoke particulate matter in human A549 and THP-1 cell lines.

    Science.gov (United States)

    Danielsen, Pernille Høgh; Møller, Peter; Jensen, Keld Alstrup; Sharma, Anoop Kumar; Wallin, Håkan; Bossi, Rossana; Autrup, Herman; Mølhave, Lars; Ravanat, Jean-Luc; Briedé, Jacob Jan; de Kok, Theo Martinus; Loft, Steffen

    2011-02-18

    Combustion of biomass and wood for residential heating and/or cooking contributes substantially to both ambient air and indoor levels of particulate matter (PM). Toxicological characterization of ambient air PM, especially related to traffic, is well advanced, whereas the toxicology of wood smoke PM (WSPM) is poorly assessed. We assessed a wide spectrum of toxicity end points in human A549 lung epithelial and THP-1 monocytic cell lines comparing WSPM from high or low oxygen combustion and ambient PM collected in a village with many operating wood stoves and from a rural background area. In both cell types, all extensively characterized PM samples (1.25-100 μg/mL) induced dose-dependent formation of reactive oxygen species and DNA damage in terms of strand breaks and formamidopyrimidine DNA glycosylase sites assessed by the comet assay with WSPM being most potent. The WSPM contained more polycyclic aromatic hydrocarbons (PAH), less soluble metals, and expectedly also had a smaller particle size than PM collected from ambient air. All four types of PM combined increased the levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine dose-dependently in A549 cells, whereas there was no change in the levels of etheno-adducts or bulky DNA adducts. Furthermore, mRNA expression of the proinflammatory genes monocyte chemoattractant protein-1, interleukin-8, and tumor necrosis factor-α as well as the oxidative stress gene heme oxygenase-1 was upregulated in the THP-1 cells especially by WSPM and ambient PM sampled from the wood stove area. Expression of oxoguanine glycosylase 1, lymphocyte function-associated antigen-1, and interleukin-6 did not change. We conclude that WSPM has small particle size, high level of PAH, low level of water-soluble metals, and produces high levels of free radicals, DNA damage as well as inflammatory and oxidative stress response gene expression in cultured human cells.

  4. A new computer-controlled air-liquid interface cultivation system for the generation of differentiated cell cultures of the airway epithelium.

    Science.gov (United States)

    Aufderheide, Michaela; Förster, Christine; Beschay, Morris; Branscheid, Detlev; Emura, Makito

    2016-01-01

    The increased application of in vitro systems in pharmacology and toxicology requires cell culture systems that facilitate the cultivation process and ensure stable, reproducible and controllable cultivation conditions. Up to now, some devices have been developed for the cultivation of cells under submersed conditions. However, systems meeting the requirements of an air-liquid interface (ALI) cultivation for the special needs of bronchial epithelial cells for example are still lacking. In order to obtain in vivo like organization and differentiation of these cells they need to be cultivated under ALI conditions on microporous membranes in direct contact with the environmental atmosphere. For this purpose, a Long-Term-Cultivation system was developed (CULTEX(®) LTC-C system) for the computer-controlled cultivation of such cells. The transwell inserts are placed in an incubator module (24 inserts), which can be adjusted for the medium level (ultrasonic pulse-echosensor), time and volume-dependent medium exchange, and frequency for mixing the medium with a rotating disc for homogeneous distribution of medium and secretion components. Normal primary freshly isolated bronchial epithelial cells were cultivated for up to 38 days to show the efficiency of such a cultivation procedure for generating 3D cultures exhibiting in vivo-like pseudostratified organization of the cells as well as differentiation characteristics like mucus-producing and cilia-forming cells. Copyright © 2015 The Authors. Published by Elsevier GmbH.. All rights reserved.

  5. Site Evaluation for Application of Fuel Cell Technology, Naval Hospital - Marine Corps Air Ground Combat Center Twentynine Palms, CA

    National Research Council Canada - National Science Library

    Binder, Michael

    2001-01-01

    ...). CERL has selected and evaluated application sites, supervised the design and installation of fuel cells, actively monitored the operation and maintenance of fuel cells, and compiled "lessons learned...

  6. Study of magnetic field to promote oxygen transfer and its application in zinc–air fuel cells

    International Nuclear Information System (INIS)

    Shi, Jicheng; Xu, Hongfeng; Lu, Lu; Sun, Xin

    2013-01-01

    Highlights: ► High magnetic strength reduces R ct and increases C d in oxygen reduction reaction. ► Oxygen diffusion and transfer coefficient become large in high magnetic strength. ► The magnetic ZAFC discharge performance is better than the nonmagnetic ZAFC. ► Increased NdFeB/C load density improves the magnetic ZAFC discharge performance. ► Excess NdFeB/C load density decreases the magnetic ZAFC discharge performance. -- Abstract: This study investigates the effects of magnetic field on oxygen transfer and the correlations of electrochemical parameters in different magnetic strengths. The discharge performance of zinc–air fuel cell (ZAFC) was tested under magnetic and nonmagnetic conditions using neodymium–iron–boron/carbon (NdFeB/C) magnetic particles in ZAFC cathode. The results showed that the oxygen diffusion coefficient (D Oi ) and transfer coefficient (α i ) increased by 102.14% and 52.38% when the magnetic strength increased from 0 mT to 5.0 mT, respectively. In addition, the electric double-layer capacitance (C d ) increased from 8.16 to 22.46 μF cm −2 , the charge-transfer resistance (R ct ) decreased from 9.43 Ω cm 2 to 6.02 Ω cm 2 , and the oxygen reduction reaction (ORR) current was improved. With the NdFeB/C load density of 2.4 mg cm −2 in ZAFC cathode, the discharge current of magnetic ZAFC increased by 13.86% compared with the nonmagnetic ZAFC at the 0.80 V discharge voltage. These results indicate that magnetic strength has a positive correlation with D Oi , α i , and the ORR current. Under magnetic attractions, the oxygen transfer process is easier at the Pt/C catalytic surface, and the discharge performance of magnetic ZAFC is superior to the nonmagnetic ZAFC. At lower NdFeB/C load density, increasing the NdFeB/C load density facilitates oxygen transfer and improves the discharge performance of ZAFC. However, the magnetic ZAFC discharge performance decreases at a higher NdFeB/C load density because of the blocked oxygen

  7. Stall/surge dynamics of a multi-stage air compressor in response to a load transient of a hybrid solid oxide fuel cell-gas turbine system

    Science.gov (United States)

    Azizi, Mohammad Ali; Brouwer, Jacob

    2017-10-01

    A better understanding of turbulent unsteady flows in gas turbine systems is necessary to design and control compressors for hybrid fuel cell-gas turbine systems. Compressor stall/surge analysis for a 4 MW hybrid solid oxide fuel cell-gas turbine system for locomotive applications is performed based upon a 1.7 MW multi-stage air compressor. Control strategies are applied to prevent operation of the hybrid SOFC-GT beyond the stall/surge lines of the compressor. Computational fluid dynamics tools are used to simulate the flow distribution and instabilities near the stall/surge line. The results show that a 1.7 MW system compressor like that of a Kawasaki gas turbine is an appropriate choice among the industrial compressors to be used in a 4 MW locomotive SOFC-GT with topping cycle design. The multi-stage radial design of the compressor enhances the ability of the compressor to maintain air flow rate during transient step-load changes. These transient step-load changes are exhibited in many potential applications for SOFC/GT systems. The compressor provides sustained air flow rate during the mild stall/surge event that occurs due to the transient step-load change that is applied, indicating that this type of compressor is well-suited for this hybrid application.

  8. Nitric oxide and superoxide mediate diesel particle effects in cytokine-treated mice and murine lung epithelial cells — implications for susceptibility to traffic-related air pollution

    Directory of Open Access Journals (Sweden)

    Manzo Nicholas D

    2012-11-01

    Full Text Available Abstract Background Epidemiologic studies associate childhood exposure to traffic-related air pollution with increased respiratory infections and asthmatic and allergic symptoms. The strongest associations between traffic exposure and negative health impacts are observed in individuals with respiratory inflammation. We hypothesized that interactions between nitric oxide (NO, increased during lung inflammatory responses, and reactive oxygen species (ROS, increased as a consequence of traffic exposure ─ played a key role in the increased susceptibility of these at-risk populations to traffic emissions. Methods Diesel exhaust particles (DEP were used as surrogates for traffic particles. Murine lung epithelial (LA-4 cells and BALB/c mice were treated with a cytokine mixture (cytomix: TNFα, IL-1β, and IFNγ to induce a generic inflammatory state. Cells were exposed to saline or DEP (25 μg/cm2 and examined for differential effects on redox balance and cytotoxicity. Likewise, mice undergoing nose-only inhalation exposure to air or DEP (2 mg/m3 × 4 h/d × 2 d were assessed for differential effects on lung inflammation, injury, antioxidant levels, and phagocyte ROS production. Results Cytomix treatment significantly increased LA-4 cell NO production though iNOS activation. Cytomix + DEP-exposed cells incurred the greatest intracellular ROS production, with commensurate cytotoxicity, as these cells were unable to maintain redox balance. By contrast, saline + DEP-exposed cells were able to mount effective antioxidant responses. DEP effects were mediated by: (1 increased ROS including superoxide anion (O2˙-, related to increased xanthine dehydrogenase expression and reduced cytosolic superoxide dismutase activity; and (2 increased peroxynitrite generation related to interaction of O2˙- with cytokine-induced NO. Effects were partially reduced by superoxide dismutase (SOD supplementation or by blocking iNOS induction. In mice, cytomix

  9. Air Pollution

    OpenAIRE

    Appleton, Bonnie Lee, 1948-2012; Koci, Joel; Harris, Roger; Sevebeck, Kathryn P.; Alleman, Dawn; Swanson, Lynette

    2009-01-01

    This publication reviews the major phytotoxic air pollutants, in decreasing order of severity, they include oxidants, sulfur dioxide, and particulates. Topics also include the connection between weather and air pollution and a section on diagnosing air pollution damage to trees.

  10. Air Abrasion

    Science.gov (United States)

    ... delivered directly to your desktop! more... What Is Air Abrasion? Article Chapters What Is Air Abrasion? What Happens? The Pros and Cons Will I Feel Anything? Is Air Abrasion for Everyone? print full article print this ...

  11. A novel structure of scalable air-cathode without Nafion and Pt by rolling activated carbon and PTFE as catalyst layer in microbial fuel cells.

    Science.gov (United States)

    Dong, Heng; Yu, Hongbing; Wang, Xin; Zhou, Qixing; Feng, Junli

    2012-11-01

    Single chambered air-cathode microbial fuel cells (MFCs) are promising to be scaled up as sustainable wastewater treatment systems. However, the current air-cathode made by brushing noble metal catalyst and Nafion binder onto carbon matrix becomes one of the biggest bottlenecks for the further development of MFCs due to its high cost, huge labor-consuming and less accuracy. A novel structure of air-cathode was constructed here by rolling activated carbon (AC) and polytetrafluoroethylene (PTFE) as catalyst layer to enhance the reproducibility and improve the performance by an optimized three-phase interface (TPI). Air-cathodes with AC/PTFE ratios of 3, 5, 6, 8 and 11 in the catalyst layer were prepared, and the physical and electrochemical techniques were employed to investigate their surface microstructure and electrochemical characteristics. Uniform cross-linked ropiness networks were observed from the catalyst layer of all the cathodes and increased as the AC/PTFE ratio decreased, while the exchange currents were positively related to this ratio. Maximum power densities (MPDs) decreased as follows: AC/PTFE = 6 (802 mW m(-2) at 3.4 A m(-2)), 5 (704 mW m(-2) at 2.2 mA m(-2)), 8 (647 mW m(-2) at 2.2 A m(-2)), 3 (597 mW m(-2) at 2.1 A m(-2)) and 11 (584 mW m(-2) at 2.0 mA m(-2)), which was due to the changes of both the capacitance characteristics and conductivities according to the electrochemical impedance spectrum (EIS) analysis. This study demonstrated that inexpensive, highly reproducible, high performance and scalable air-cathode can be produced by rolling method without using noble metal and expensive binder. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. One pot synthesis of water-dispersible dehydroascorbic acid coated Fe3O4 nanoparticles under atmospheric air: blood cell compatibility and enhanced magnetic resonance imaging.

    Science.gov (United States)

    Gupta, Hariom; Paul, P; Kumar, Naresh; Baxi, Seema; Das, Dipti P

    2014-09-15

    Water dispersible and biologically important molecule dehydroascorbic acid (DHA, capable to cross the blood brain barrier) coated Fe3O4 superparamagnetic nanoparticles having an average size of ∼6 nm were synthesized through one pot aqueous coprecipitation method under atmospheric air. An antioxidant ascorbic acid (AA) used in the synthesis oxidized itself to dehydroascorbic acid (DHA) to consume dissolved or available oxygen in reaction mixture which died away the oxidative impact of atmospheric air and formed DHA encapsulated the Fe3O4 nanoparticles which stabilized the Fe3O4 nanoparticles and significantly enhanced their colloidal solubility in water. Fe3O4 phase, superparamagnetic property, DHA coating and stable colloidal solubility in water were confirmed by means of XPS, VSM, IR and zeta potential analysis respectively. T1, T2 and T2(∗) weighted magnetic resonance imaging (MRI) and corresponding relaxivity (r1=0.416, r2=50.28 and r2(∗)=123.65 mM(-1) and r2/r1=120.86, r2(∗)r1=297.23) of colloidally dispersed DHA-coated nanoparticle water phantom revealed a strong contrast enhancement in T2 and T2(∗) weighted images. The compatibility of DHA-coated Fe3O4 nanoparticles toward human blood cells was examined by means of cell counting and cell morphological analysis with the use of optical microscope and scanning electron microscope imaging. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Twenty Years of AIRE

    Directory of Open Access Journals (Sweden)

    Roberto Perniola

    2018-02-01

    Full Text Available About two decades ago, cloning of the autoimmune regulator (AIRE gene materialized one of the most important actors on the scene of self-tolerance. Thymic transcription of genes encoding tissue-specific antigens (ts-ags is activated by AIRE protein and embodies the essence of thymic self-representation. Pathogenic AIRE variants cause the autoimmune polyglandular syndrome type 1, which is a rare and complex disease that is gaining attention in research on autoimmunity. The animal models of disease, although not identically reproducing the human picture, supply fundamental information on mechanisms and extent of AIRE action: thanks to its multidomain structure, AIRE localizes to chromatin enclosing the target genes, binds to histones, and offers an anchorage to multimolecular complexes involved in initiation and post-initiation events of gene transcription. In addition, AIRE enhances mRNA diversity by favoring alternative mRNA splicing. Once synthesized, ts-ags are presented to, and cause deletion of the self-reactive thymocyte clones. However, AIRE function is not restricted to the activation of gene transcription. AIRE would control presentation and transfer of self-antigens for thymic cellular interplay: such mechanism is aimed at increasing the likelihood of engagement of the thymocytes that carry the corresponding T-cell receptors. Another fundamental role of AIRE in promoting self-tolerance is related to the development of thymocyte anergy, as thymic self-representation shapes at the same time the repertoire of regulatory T cells. Finally, AIRE seems to replicate its action in the secondary lymphoid organs, albeit the cell lineage detaining such property has not been fully characterized. Delineation of AIRE functions adds interesting data to the knowledge of the mechanisms of self-tolerance and introduces exciting perspectives of therapeutic interventions against the related diseases.

  14. Tumor Spread Through Air Spaces Is an Independent Predictor of Recurrence-free Survival in Patients With Resected Lung Squamous Cell Carcinoma.

    Science.gov (United States)

    Kadota, Kyuichi; Kushida, Yoshio; Katsuki, Naomi; Ishikawa, Ryou; Ibuki, Emi; Motoyama, Mutsumi; Nii, Kazuhito; Yokomise, Hiroyasu; Bandoh, Shuji; Haba, Reiji

    2017-08-01

    Tumor spread through air spaces (STAS) is a newly recognized pattern of invasion in lung adenocarcinoma. However, clinical significance of STAS has not yet been characterized in lung squamous cell carcinoma. In this study, we investigated whether STAS could determine clinical outcome in Japanese patients with lung squamous cell carcinoma. We reviewed tumor slides from surgically resected lung squamous cell carcinomas (n=216). STAS was defined as tumor cells within air spaces in the lung parenchyma beyond the edge of the main tumor. Tumors were evaluated for histologic subtypes, tumor budding, and nuclear diameter. Recurrence-free survival (RFS) was analyzed using the log-rank test and the Cox proportional hazards model. Tumor STAS was observed in 87 patients (40%), increasing incidence with lymph node metastasis (P=0.037), higher pathologic stage (P=0.026), and lymphatic invasion (P=0.033). All cases with STAS showed a solid nest pattern. The 5-year RFS for patients with STAS was significantly lower than it was for patients without STAS in all patients (P=0.001) and in stage I patients (n=134; P=0.041). On multivariate analysis, STAS was an independent prognostic factor of a worse RFS (hazard ratio=1.61; P=0.023). Patients with STAS had a significantly increased risk of developing locoregional and distant recurrences (P=0.012 and 0.001, respectively). We found that tumor STAS was an independent predictor of RFS in patients with resected lung squamous cell carcinoma, and it was associated with aggressive tumor behavior.

  15. Comparison of Two Human Lung Cell Lines to Study Genotoxicity of Complex Mixtures of the Organic Air Pollutants.

    Czech Academy of Sciences Publication Activity Database

    Schmuczerová, Jana; Milcová, Alena; Špátová, Milada; Šrám, Radim; Topinka, Jan

    2013-01-01

    Roč. 54, Supplement 1 (2013), S43-S43 ISSN 0893-6692. [Annual Meeting of the Environmental-Mutagenesis-and-Genomics-Society (EMGS) /44./. 21.09.2013-25.09.2013, Monterey] Institutional support: RVO:68378041 Keywords : environmental * air pollutants * ecology Subject RIV: DN - Health Impact of the Environment Quality

  16. In vitro exposure of human lung cells to emissions of several indoor air sources created in a climate chamber

    NARCIS (Netherlands)

    Bluyssen, P.M.; Alblas, M.J.; Tuinman, I.L.

    2013-01-01

    In the last decade, studies on indoor air pollution suggest a link between exposure to indoor particulate matter and compounds, in particular ultrafine particles and secondary organic aerosols, and several health effects. The mechanisms of how those complex mixtures relate to health effects are

  17. Electricity production and phosphorous recovery as struvite from synthetic wastewater using magnesium-air fuel cell electrocoagulation.

    Science.gov (United States)

    Kim, Jung Hwan; An, Byung Min; Lim, Dae Hwan; Park, Joo Yang

    2018-04-01

    This research was based on the investigation of a major principle, regarding the effects of NaCl and KH 2 PO 4 concentrations on struvite recovery, with electricity production using magnesium-air fuel cell electrocoagulation, in accordance with the concentration of phosphorous and chloride. The weight ratio of N:P in the synthetic wastewater was in the range of 1.2-21. The concentration of NH 4 Cl was fixed at 0.277 M (approximately 3888 ppm as NH 3 -N and 5000 ppm as NH 4 ), while PO 4 -P was in the range of 0.006-0.1 M. In addition, the concentrations of NaCl as electrolyte were 0, 0.01, and 0.1 M. Phosphate removal increased linearly with the Mg:P ratio, up to approximately 1.1 mol mol -1 , irrespective of the initial concentrations of phosphate and NaCl. The one-to-one reaction as mole ratio between phosphate and the dissolved Mg ions resulted in phosphate removal, with the production of a one-to-one magnesium/phosphate mineral, such as struvite. The average removal rate of phosphorous in experiments without a dose of NaCl was 4.19 mg P cm -2 h -1 , which was lower than the relative values of 5.35 and 4.77 mg P cm -2 h -1 , in experiments with 0.01 and 0.1 M NaCl. The dissolution rate of Mg with electro-oxidation determined the rate of phosphorous removal with struvite recovery. The average removal rates of phosphorous with dose concentrations of 0.006, 0.01 and 0.02 M KH 2 PO 4 were 4.02, 5.54, 6.9 mg P cm -2 h -1 , respectively, which increased with the increase in KH 2 PO 4 dose. However, in experiments with a dose of 0.05 and 0.1 M KH 2 PO 4, the average removal rates of phosphorous decreased to 4.84 and 2.51, respectively. The maximum power densities in the electrolyte mixture of 0.05 M KH 2 PO 4 /0.277 M NH 4 Cl, 0.01 M NaCl/0.05 M KH 2 PO 4 /0.277 M NH 4 Cl, and 0.1 NaCl/0.05 KH 2 PO 4 /0.277 M NH 4 Cl were 25.1, 26.4, and 33.2 W/m 2 , respectively. The increase in the NaCl dose concentration resulted in an

  18. Efficient and stable CH3NH3PbI3-x(SCN)x planar perovskite solar cells fabricated in ambient air with low-temperature process

    Science.gov (United States)

    Zhang, Zongbao; Zhou, Yang; Cai, Yangyang; Liu, Hui; Qin, Qiqi; Lu, Xubing; Gao, Xingsen; Shui, Lingling; Wu, Sujuan; Liu, Jun-Ming

    2018-02-01

    Planar perovskite solar cells (PSCs) based on CH3NH3PbI3-x(SCN)x (SCN: thiocyanate) active layer and low-temperature processed TiO2 films are fabricated by a sequential two-step method in ambient air. Here, alkali thiocyanates (NaSCN, KSCN) are added into Pb(SCN)2 precursor to improve the microstructure of CH3NH3PbI3-x(SCN)x perovskite layers and performance of the as-prepared PSCs. At the optimum concentrations of alkali thiocyanates as additives, the as-prepared NaSCN-modified and KSCN-modified PSCs demonstrate the efficiencies of 16.59% and 15.63% respectively, being much higher than 12.73% of the reference PSCs without additives. This improvement is primarily ascribed to the enhanced electron transport, reduced recombination rates and much improved microstructures with large grain size and low defect density at grain boundaries. Importantly, it is revealed that the modified PSCs at the optimized concentrations of alkali thiocyanates additives exhibit remarkably improved stability than the reference PSCs against humid circumstance, and a continuous exposure to humid air without encapsulation over 45 days only records about 5% degradation of the efficiency. These findings provide a facile approach to fabricate efficient and stable PSCs by low processing temperature in ambient air, both of which are highly preferred for future practical applications of PSCs.

  19. Added value of stress related gene inductions in HepG2 cells as effect measurement in monitoring of air pollution

    Science.gov (United States)

    Nobels, Ingrid; Vanparys, Caroline; Van den Heuvel, Rosette; Vercauteren, Jordy; Blust, Ronny

    2012-08-01

    In this study we studied the effects of particulate matter samples (PM) through gene expression analysis in a routine air quality monitoring campaign by the Flemish Environment Agency (VMM, Belgium). We selected a human hepatoma (HepG2) multiple endpoint reporter assay for targeted stress related endpoint screening. Organic extracts of air samples (total suspended particles, TSP) were collected during one year in an industrial, urban and background location in Flanders, Belgium. Simultaneously, meteorological conditions (temperature, wind speed and precipitation) and particulate matter size ≤ 10 μM (PM10), organic (OC), elemental (EC) and total (TC) carbon were monitored and air samples were collected for chemical analysis (11 PAHs). Correlations between the induction of the different stress genes and the chemical pollutants were analysed. Exposure of HepG2 cells to daily air equivalents (20 m3) of organic TSP extracts revealed the dominant induction of the xenobiotic response element (Xre) and phase I (Cyp1A1) and phase II (GstYa) biotransformation enzymes. Additional effects were the induction of c-Fos, a proto-oncogen and Gadd45, a marker for cell cycle disturbance and responsive to genotoxic compounds. Inductions of other relevant pathways, such as sequestration of heavy metals, retinoids response, protein misfolding and increased cAMP levels were measured occasionally. A significant correlation was found between the genes Cyp1A1 (a typical marker for presence of PAHs and dioxin like compounds), c-Fos, Gadd45, (responsive to DNA damaging compounds) and the amount of PM10 and elemental carbon (EC) whereas no correlation was found between these genes and total PAHs content. This may suggest that the observed induction of Cyp1A1 and DNA damage related genes was provoked (partially) by other particle bound compounds (e.g. pesticides, PCBs, brominated flame retardants, dioxins, …), than PAHs. The contribution of particle bound compounds, other than PAHs might

  20. Development of a Novel Home Cogeneration System using a Polymer Electrolyte Fuel Cell which Enabled Air Conditioning by Its Low-TemperatureWaste Heat

    Science.gov (United States)

    Nishimura, Nobuya; Honda, Kuniaki; Kawakami, Ryuichiro; Nishikawa, Toshimichi; Iyota, Hiroyuki; Nomura, Tomohiro

    Micro-scale distributed power generation system, which means a micro-cogeneration system in almost cases, has been paid a great attention from a standpoint of saving fossil fuels' consumption and preventing global warming. Especially, polymer electrolyte fuel cell (PEFC) is considered the most promising power generation system for small scale commercial use and residential use. In the PEFC cogeneration system, small amount of waste heat at low temperature from a cell stack is almost used to produce hot water. Therefore, in the paper, we proposed a new heat utilization method of the waste heat for air conditioning. In the proposed home cogeneration system, absorption refrigerator is introduced in order to produce chilled water. Thermal performances of the proposed system have been analyzed by a computer simulation which was developed for the prediction both of power generation characteristics of PEFC and absorption refrigerator's behavior.

  1. Treatment of synthetic arsenate wastewater with iron-air fuel cell electrocoagulation to supply drinking water and electricity in remote areas.

    Science.gov (United States)

    Kim, Jung Hwan; Maitlo, Hubdar Ali; Park, Joo Yang

    2017-05-15

    Electrocoagulation with an iron-air fuel cell is an innovative arsenate removal system that can operate without an external electricity supply. Thus, this technology is advantageous for treating wastewater in remote regions where it is difficult to supply electricity. In this study, the possibility of real applications of this system for arsenate treatment with electricity production was verified through electrolyte effect investigations using a small-scale fuel cell and performance testing of a liter-scale fuel cell stack. The electrolyte species studied were NaCl, Na 2 SO 4 , and NaHCO 3 . NaCl was overall the most effective electrolyte for arsenate treatment, although Na 2 SO 4 produced the greatest electrical current and power density. In addition, although the current density and power density were proportional to the concentrations of NaCl and Na 2 SO 4 , the use of concentrations above 20 mM of NaCl and Na 2 SO 4 inhibited arsenate treatment due to competition effects between anions and arsenate in adsorption onto the iron hydroxide. The dominant iron hydroxide produced at the iron anode was found to be lepidocrocite by means of Raman spectroscopy. A liter-scale four-stack iron-air fuel cell with 10 mM NaCl electrolyte was found to be able to treat about 300 L of 1 ppm arsenate solution to below 10 ppb during 1 day, based on its 60-min treatment capacity, as well as produce the maximum power density of 250 mW/m 2 . Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Design and Control of High Temperature PEM Fuel Cell Systems using Methanol Reformers with Air or Liquid Heat Integration

    OpenAIRE

    Andreasen, Søren Juhl; Sahlin, Simon Lennart; Justesen, Kristian Kjær; Kær, Søren Knudsen

    2013-01-01

    The present work describes the ongoing development of high temperature PEM fuel cell systems fuelled by steam reformed methanol. Various fuel cell system solutions exist, they mainly differ depending on the desired fuel used. Hightemperature PEM (HTPEM) fuel cells offer the possibility of using liquid fuels such as methanol, due to the increased robustness of operating at higher temperatures (160-180oC). Using liquid fuels such as methanol removes the high volume demands of compressed hydroge...

  3. Efficient, air-stable colloidal quantum dot solar cells encapsulated using atomic layer deposition of a nanolaminate barrier

    KAUST Repository

    Ip, Alexander H.

    2013-12-23

    Atomic layer deposition was used to encapsulate colloidal quantum dot solar cells. A nanolaminate layer consisting of alternating alumina and zirconia films provided a robust gas permeation barrier which prevented device performance degradation over a period of multiple weeks. Unencapsulated cells stored in ambient and nitrogen environments demonstrated significant performance losses over the same period. The encapsulated cell also exhibited stable performance under constant simulated solar illumination without filtration of harsh ultraviolet photons. This monolithically integrated thin film encapsulation method is promising for roll-to-roll processed high efficiency nanocrystal solar cells. © 2013 AIP Publishing LLC.

  4. Achieving high-powered Zn/air fuel cell through N and S co-doped hierarchically porous carbons with tunable active-sites as oxygen electrocatalysts

    Science.gov (United States)

    Tang, Qiaowei; Wang, Luming; Wu, Mingjie; Xu, Nengneng; Jiang, Lei; Qiao, Jinli

    2017-10-01

    Electrochemical reduction of oxygen is the heart of the next-generation energy technologies to fuel cells and metal-air batteries, of which the reference catalysts suffer from two critical bottlenecks lying in their insufficient electroactivities and unclear active site structures. Herein, we introduce the effectively hierarchically porous carbons (HPCs) as the active-sites enriched platform for oxygen electroreduction. Three quaternized copolymers (PUB, PAADDA and PICP) with different chemical structures are used to pursue Fe/N/S-tailored ORR electrocatalysts. The most efficient one prepared by PAADDA gives the onset potential of 0.94 V and a half-wave potential of 0.85 V in basic solution, as well as superb electroactivities of low H2O2% and high electron transfer number in both alkaline and acidic medium. Surprisingly, they all display high discharge power density as applied to Zn-air fuel cells, and the HPCs-PAADDA catalyst thrillingly reaches 516.3 mW cm-2 when catalyst loading is optimized to 5.0 mg cm-2. The results elucidate that the polymer with long aliphatic chain is propitious to trap metals to create active sites and enwrap silica template to construct uniform pore structure. Only two kinds of nitrogen configuration (pyridinic-N and graphitic-N) are found with distinct structure in these HPCs, which happens to be active sites.

  5. Rechargeability of Li-air cathodes pre-filled with discharge products using an ether-based electrolyte solution: implications for cycle-life of Li-air cells.

    Science.gov (United States)

    Meini, Stefano; Tsiouvaras, Nikolaos; Schwenke, K Uta; Piana, Michele; Beyer, Hans; Lange, Lukas; Gasteiger, Hubert A

    2013-07-21

    The instability of currently used electrolyte solutions and of the carbon support during charge-discharge in non-aqueous lithium-oxygen cells can lead to discharge products other than the desired Li2O2, such as Li2CO3, which is believed to reduce cycle-life. Similarly, discharge in an O2 atmosphere which contains H2O and CO2 impurities would lead to LiOH and Li2CO3 discharge products. In this work we therefore investigate the rechargeability of model cathodes pre-filled with four possible Li-air cell discharge products, namely Li2O2, Li2CO3, LiOH, and Li2O. Using Online Electrochemical Mass Spectrometry (OEMS), we determined the charge voltages and the gases evolved upon charge of pre-filled electrodes, thus determining the reversibility of the formation/electrooxidation reactions. We show that Li2O2 is the only reversible discharge product in ether-based electrolyte solutions, and that the formation of Li2CO3, LiOH, or Li2O is either irreversible and/or reacts with the electrolyte solution or the carbon during its oxidation.

  6. Parasitic corrosion-resistant anode for use in metal/air or metal/O/sub 2/ cells

    Science.gov (United States)

    Joy, R.W.; Smith, D.F.

    1982-09-20

    A consumable metal anode is described which is used in refuelable electrochemical cells and wherein at least a peripheral edge portion of the anode is protected against a corrosive alkaline environment of the cell by the application of a thin metal coating, the coating being formed of metals such as nickel, silver, and gold.

  7. Hot air treatment reduces postharvest decay and delays softening of cherry tomato by regulating gene expression and activities of cell wall-degrading enzymes.

    Science.gov (United States)

    Wei, Yingying; Zhou, Dandan; Wang, Zhenjie; Tu, Sicong; Shao, Xingfeng; Peng, Jing; Pan, Leiqing; Tu, Kang

    2018-04-01

    Fruit softening facilitates pathogen infection and postharvest decay, leading to the reduction of shelf-life. Hot air (HA) treatment at 38 °C for 12 h is effective in reducing postharvest disease and chilling injury of tomato fruit. To explore the effect and mechanism of HA treatment on reducing postharvest decay and softening of cherry tomato, fruit at the mature green stage were treated with HA and then stored at 20 °C for 15 days. Changes in natural decay incidence, firmness, cell wall compositions, activities and gene expression of cell wall-degrading enzymes of cherry tomatoes were assessed. HA treatment reduced natural decay incidence, postponed the firmness decline, inhibited the respiration rate and ethylene production, and retarded pectin solubilisation and cellulose degradation of cherry tomatoes. Enzymatic activities and gene expression of pectin methylesterase, polygalacturonase, cellulase and β-galactosidase were inhibited by HA treatment. In addition, the gene expression of LeEXP1 was reduced, while LeEXT was up-regulated after HA treatment. Our findings suggested that HA treatment could inhibit cell wall degradation and postpone softening of cherry tomatoes by regulating gene expression and activities of cell wall-degrading enzymes, resulting in the reduction of postharvest decay. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  8. Preliminary design and analysis of aluminum-air cells providing for continuous feed and full utilization of anodes

    Science.gov (United States)

    Cooper, J. F.

    1981-08-01

    The advantages, disadvantages, and engineering problem areas of the wedge shaped cells in anodes utilization are reviewed. The importance of solution side current collection to the practicality of this approach when used with alkaline electrolytes is identified. The relationship between cell height and total anode mass is derived for this and corresponding cells of the M1 design. It is concluded that the M1-CF design may provide the basis for an automotive battery of greater simplicity, reliability, and economy than earlier designs.

  9. Fabrication of efficient graphene-doped polymer/fullerene bilayer organic solar cells in air using spin coating followed by ultrasonic vibration post treatment

    Science.gov (United States)

    Zabihi, Fatemeh; Chen, Qianli; Xie, Yu; Eslamian, Morteza

    2016-12-01

    In this work, in an attempt to improve the performance and lifetime of organic solar cells, P3HT photon absorbing polymer was doped with graphene (G) nano-sheets, to make light harvesting G-P3HT composite thin film. The composite this film was then employed as the donor of a bilayer organic solar cell with the structure of glass/ITO/PEDOT:PSS/G-P3HT/C60/Al. The reference P3HT:PCBM bulk heterojunction solar cell was also fabricated for comparison. All solution-processed layers were made by spin coating in humid air (Shanghai, China); C60 and Al were deposited by thermal evaporation. An effective mechanical treatment approach developed by the authors, i.e. the application of forced ultrasonic vibration on the wet spun-on films, was used to improve the dispersion of graphene in G-P3HT composite films to obtain a uniform nanostructure. This mechanical method eliminates tedious and expensive chemical steps, currently performed to engineer the structure of organic solar cells. It is evidenced that the G-P3HT composite thin films, post treated by ultrasonic vibration at the optimum vibration duration, possess superior electrical conductivity, charge carrier mobility and density, uniform surface potential distribution, and lower surface roughness, compared to those of P3HT and G-P3HT thin films made without vibration. The results show significant improvement in the power conversion efficiency (PCE) of vibration-treated G-P3HT/C60 cell (PCE = 5.17%, the highest reported for this structure), substantiating the strong positive effect of using graphene and forced vibration for the fabrication of P3HT active layer in the bilayer cell structure.

  10. Effects of solubility of urban air fine and coarse particles on cytotoxic and inflammatory responses in RAW 264.7 macrophage cell line

    International Nuclear Information System (INIS)

    Jalava, Pasi I.; Salonen, Raimo O.; Pennanen, Arto S.; Happo, Mikko S.; Penttinen, Piia; Haelinen, Arja I.; Sillanpaeae, Markus; Hillamo, Risto; Hirvonen, Maija-Riitta

    2008-01-01

    We investigated the inflammatory and cytotoxic activities of the water-soluble and -insoluble as well as organic-solvent-soluble and -insoluble fractions of urban air fine (PM 2.5-0.2 ) and coarse (PM 10-2.5 ) particulate samples. The samples were collected with a high volume cascade impactor (HVCI) in 7-week sampling campaigns of selected seasons in six European cities. Mouse macrophage cells (RAW 264.7) were exposed to the samples for 24 h. The production of nitric oxide (NO) and proinflammatory cytokines (TNFα, IL-6), and cytotoxicity (MTT-test, apoptosis, cell cycle) were measured. The inflammatory and cytotoxic responses in both size ranges were mostly associated with the insoluble particulate fractions. However, both the water- and organic-solvent-soluble particulate fractions induced TNFα production and apoptosis and had some other cytotoxic effects. Soil-derived water-soluble and -insoluble components of the chemical PM 2.5-0.2 mass closure had consistent positive correlations with the responses, while the correlations were negative with the secondary inorganic anions (NO 3 - , NH 4 + , non-sea-salt SO 4 2- ) and particulate organic matter (POM). With the PM 10-2.5 samples, sea salt and soluble soil components correlated positively with the induced toxic responses. In this size range, a possible underestimation of the insoluble, soil-related compounds containing Si and Ca, and biological components of POM, increased uncertainties in the evaluation of associations of the mass closure components with the responses. It is concluded that insoluble components of the complex urban air particulate mixture exert the highest inflammatory and cytotoxic activities in the macrophage cell line but, at the same time, they may operate as carriers for active water- and lipid-soluble components

  11. Imaging the Spatial Evolution of Degradation in Perovskite/Si Tandem Solar Cells After Exposure to Humid Air

    KAUST Repository

    Song, Zhaoning

    2017-09-14

    Monolithically integrated two-terminal perovskite/Si tandem solar cells promise to achieve high power conversion efficiency. However, there is a concern that the stability of the perovskite top cell will limit the long-term performance of tandem devices. To investigate the impact of perovskite cell degradation on the photocurrent generation and collection in the individual subcells, we employed light beam induced current mapping to spatially resolve the photocurrent under controlled humidity conditions. The evolution of the device behavior is consistent with the formation of an optically transparent hydrated perovskite phase that allows the bottom Si cell to continue to generate photocurrent at the probing wavelength (532 nm). Additional measurements were performed on perovskite thin films on glass substrates to verify the interpretation.

  12. Oxidative stress and DNA damage caused by the urban air pollutant 3-NBA and its isomer 2-NBA in human lung cells analyzed with three independent methods.

    Science.gov (United States)

    Nagy, Eszter; Johansson, Clara; Zeisig, Magnus; Möller, Lennart

    2005-11-15

    The air pollutant 3-nitrobenzanthrone (3-NBA), emitted in diesel exhaust, is a potent mutagen and genotoxin. 3-NBA can isomerise to 2-nitrobenzanthrone (2-NBA), which can become more than 70-fold higher in concentration in ambient air. In this study, three independent methods have been employed to evaluate the oxidative stress and genotoxicity of 2-NBA compared to 3-NBA in the human A549 lung cell line. HPLC-EC/UV was applied for measurements of oxidative damage in the form of 8-oxo-2'-deoxyguanosine (8-oxodG), (32)P-HPLC for measurements of lipophilic DNA-adducts, and the Comet assay to measure a variety of DNA lesions, including oxidative stress. No significant oxidative damage from either isomer was found regarding formation of 8-oxodG analysed using HPLC-EC/UV. However, the Comet assay (with FPG-treatment), which is more sensitive and detects more types of damages compared to HPLC-EC/UV, showed a significant effect from both 3-NBA and 2-NBA. (32)P-HPLC revealed a strong DNA-adduct formation from both 3-NBA and 2-NBA, and also a significant difference between both isomers compared to negative control. These results clearly show that 2-NBA has a genotoxic potential. Even if the DNA-adduct forming capacity and the amount of DNA lesions measured with the (32)P-HPLC and Comet assay is about one third of 3-NBA, the high abundance of 2-NBA in ambient air calls for further investigation and evaluation of its health hazard.

  13. Nuclear abnormalities in cells from nasal epithelium: a promising assay to evaluate DNA damage related to air pollution in infants.

    Science.gov (United States)

    Mergener, Michelle; Rhoden, Cláudia R; Amantéa, Sérgio L

    2014-01-01

    This study intends to provide a quick, easy, and inexpensive way to assess nuclear abnormalities such as micronuclei and bud frequencies; binucleated, karyorrhectic, karyolytic, pycnotic, and condensed chromatin cells in nasal scrapings of infants, which are particularly important for conducting genotoxic studies related to the inhaled atmosphere in pediatric populations. Nasal swab samples were collected from 40 infants under 12 months of age using a small cytobrush. 2,000 cells from each infant sample were analyzed and classified according to the frequency of nuclear abnormalities. Rates of nuclear abnormalities found agree with values reported in other studies of neonates and children. This study found 0.13% of cells with micronuclei; 1.20% karyorrhexis; 0.03% pyknosis; 10.85% karyolysis; 1.11% condensed chromatin; 0.54 binucleated cells; and 0.02% nuclear bud. Differences were not observed between genders or environmental passive smoking, nor was any age correlation found. The assay proposed here is suitable for assessing the frequency of nuclear abnormalities from nasal cells in infants. Copyright © 2014 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  14. Nuclear abnormalities in cells from nasal epithelium: a promising assay to evaluate DNA damage related to air pollution in infants

    Directory of Open Access Journals (Sweden)

    Michelle Mergener

    2014-12-01

    Full Text Available OBJECTIVES: This study intends to provide a quick, easy, and inexpensive way to assess nuclear abnormalities such as micronuclei and bud frequencies; binucleated, karyorrhectic, karyolytic, pycnotic, and condensed chromatin cells in nasal scrapings of infants, which are particularly important for conducting genotoxic studies related to the inhaled atmosphere in pediatric populations. METHODS: Nasal swab samples were collected from 40 infants under 12 months of age using a small cytobrush. 2,000 cells from each infant sample were analyzed and classified according to the frequency of nuclear abnormalities. RESULTS: Rates of nuclear abnormalities found agree with values reported in other studies of neonates and children. This study found 0.13% of cells with micronuclei; 1.20% karyorrhexis; 0.03% pyknosis; 10.85% karyolysis; 1.11% condensed chromatin; 0.54 binucleated cells; and 0.02% nuclear bud. Differences were not observed between genders or environmental passive smoking, nor was any age correlation found. CONCLUSION: The assay proposed here is suitable for assessing the frequency of nuclear abnormalities from nasal cells in infants.

  15. Effects of nozzle type atmospheric dry air plasma on L929 fibroblast cells hybrid poly (ε-caprolactone)/chitosan/poly (ε-caprolactone) scaffolds interactions.

    Science.gov (United States)

    Ozkan, Ozan; Turkoglu Sasmazel, Hilal

    2016-08-01

    In the study presented here, in order to improve the surface functionality and topography of poly (ε-caprolactone) (PCL)/chitosan/PCL hybrid tissue scaffolds fabricated layer by layer with electrospinning technique, an atmospheric pressure nozzle type plasma surface modification was utilized. The optimization of the plasma process parameters was carried out by monitoring the changes in surface hydrophilicity by using contact angle measurements. SEM, AFM and XPS analyses were utilized to observe the changes in topographical and chemical properties of the modified surfaces. The results showed that applied plasma modification altered the nanotopography and the functionality of the surfaces of the scaffolds. The modification applied for 9 min from a distance of 17 cm was found to provide the possible contact angle value (75.163±0.083) closest to the target value which is the value of tissue culture polystyrene (TCPS) petri dishes (∼49.7°), compared to the unmodified samples (84.46±3.86). In vitro cell culture was carried out by L929 mouse fibroblast cell line in order to examine the effects of plasma surface modification on cell-material interactions. Standard MTT assay showed improved cell viability on/within modified scaffolds confirmed with the observations of the cell attachment and the morphology by means of SEM, fluorescence and confocal imaging. The experiments performed in the study proved the enhanced biocompatibility of the nozzle type dry air plasma modified scaffolds. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  16. Measurements of 220Rn in air using a flow-through Lucas cell and multiple time analysis of recorded pulse events

    International Nuclear Information System (INIS)

    Falk, R.; Moere, H.; Nyblom, L.

    1992-01-01

    A multiple time analysis technique has successfully been applied for measurements of environmental levels of 220 Rn using a flow-through Lucas radon detector. The method is based on selective alpha counting of the short-lived nuclide 216 Pu. Owing to its short half-life (0.145 s), the alpha particle emitted at the decay of a 220 Rn atom will, within a fraction of a second, be followed by an alpha particle from the decay of 216 Po. By measuring the time interval between successive alpha counts followed by a multiple time analysis, the 216 Po activity and thereby the 220 Rn activity can be calculated. The method applied to a commercial instrument with a 160 ml Lucas cell as detector shows that a mean 220 Rn air concentration of less than 20 Bq.m -3 can easily be determined even if the 222 Rn air concentration is 10 times higher and varies. At lower 222 Rn levels a 220 Rn concentration less than 1 Bq.m -3 can be assessed using this technique. The method will be described together with some examples of its practical use. (author)

  17. Efficient removal of nitrobenzene and concomitant electricity production by single-chamber microbial fuel cells with activated carbon air-cathode.

    Science.gov (United States)

    Zhang, Enren; Wang, Feng; Zhai, Wenjing; Scott, Keith; Wang, Xu; Diao, Guowang

    2017-04-01

    Single-chamber microbial fuel cells (S-MFCs) with bio-anodes and activated carbon (AC) air-cathodes showed high nitrobenzene (NB) tolerance and NB removal with concomitant electricity production. The maximum power over 25Wm -3 could be obtained when S-MFCs were operated in the NB loading range of 1.2-6.2molm -3 d -1 , and stable electricity production over 13.7Wm -3 could be produced in a NB loading range of 1.2-14.7molm -3 d -1 . The present S-MFCs exhibited high NB removal performance with NB removal efficiency over 97% even when the NB loading rate was increased to 17.2molm -3 d -1 . The potential NB reduced product (i.e. aniline) could also be effectively removed from influents. The findings in this study means that single-chamber MFCs assembled with pre-enriched bio-anodes and AC air-cathodes could be developed as effective bio-electrochemical systems to remove NB from wastewaters and to harvest energy instead of consuming energy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Effect of air-exposed biocathode on the performance of a Thauera-dominated membraneless single-chamber microbial fuel cell (SCMFC).

    Science.gov (United States)

    Yang, Nuan; Zhan, Guoqiang; Wu, Tingting; Zhang, Yanyan; Jiang, Qinrui; Li, Daping; Xiang, Yuanying

    2018-04-01

    To investigate the effect of air-exposed biocathode (AEB) on the performance of single-chamber microbial fuel cell (SCMFC), wastewater quality, bioelectrochemical characteristics and the electrode biofilms were researched. It was demonstrated that exposing the biocathode to air was beneficial to nitrogen removal and current generation. In Test 1 of 95% AEB, removal rates of ammonia, total nitrogen (TN) and chemical oxygen demand (COD) reached 99.34%±0.11%, 99.34%±0.10% and 90.79%±0.12%, respectively. The nitrogen removal loading rates were 36.38gN/m 3 /day. Meanwhile, current density and power density obtained at 0.7A/m 3 and 104mW/m 3 respectively. Further experiments on open-circuit (Test 2) and carbon source (Test 3) indicated that this high performance could be attributed to simultaneous biological nitrification/denitrification and aerobic denitrification, as well as bioelectrochemical denitrification. Results of community analysis demonstrated that both microbial community structures on the surface of the cathode and in the liquid of the chamber were different. The percentage of Thauera, identified as denitrifying bacteria, maintained at a high level of over 50% in water, but decreased gradually in the AEB. Moreover, the genus Nitrosomonas, Alishewanella, Arcobacter and Rheinheimera were significantly enriched in the AEB, which might contribute to both enhancement of nitrogen removal and electricity generation. Copyright © 2017. Published by Elsevier B.V.

  19. Satellite Sounder Observations of Contrasting Tropospheric Moisture Transport Regimes: Saharan Air Layers, Hadley Cells, and Atmospheric Rivers

    Energy Technology Data Exchange (ETDEWEB)

    Nalli, Nicholas R.; Barnet, Christopher D.; Reale, Tony; Liu, Quanhua; Morris, Vernon R.; Spackman, J. Ryan; Joseph, Everette; Tan, Changyi; Sun, Bomin; Tilley, Frank; Leung, L. Ruby; Wolfe, Daniel

    2016-12-01

    This paper examines the performance of satellite sounder atmospheric vertical moisture proles (AVMP) under tropospheric conditions encompassing moisture contrasts driven by convection and advection transport mechanisms, specifically Atlantic Ocean Saharan air layers (SALs) and Pacific Ocean moisture conveyer belts (MCBs) commonly referred to as atmospheric rivers (ARs), both of these being mesoscale to synoptic meteorological phenomena within the vicinity of subtropical Hadley subsidence zones. Operational AVMP environmental data records retrieved from the Suomi National Polar-orbiting Partnership (SNPP) NOAA-Unique Combined Atmospheric Processing System (NUCAPS) are collocated with dedicated radiosonde observations (RAOBs) obtained from ocean-based intensive field campaigns; these RAOBs provide uniquely independent correlative truth data not assimilated into numerical weather prediction models for satellite sounder validation over open ocean. Using these marine-based data, we empirically assess the performance of the operational NUCAPS AVMP product for detecting and resolving these tropospheric moisture features over otherwise RAOB-sparse regions.

  20. Enhancement of electricity production in a mediatorless air-cathode microbial fuel cell using Klebsiella sp. IR21.

    Science.gov (United States)

    Lee, Yun-Yeong; Kim, Tae Gwan; Cho, Kyung-Suk

    2016-06-01

    A novel dissimilatory iron-reducing bacteria, Klebsiella sp. IR21, was isolated from the anode biofilm of an MFC reactor. Klebsiella sp. IR21 reduced 27.8 % of ferric iron to ferrous iron demonstrating that Klebsiella sp. IR21 has electron transfer ability. Additionally, Klebsiella sp. IR21 generated electricity forming a biofilm on the anode surface. When a pure culture of Klebsiella sp. IR21 was supplied into a single chamber, air-cathode MFC fed with a mixture of glucose and acetate (500 mg L(-1) COD), 40-60 mV of voltage (17-26 mA m(-2) of current density) was produced. Klebsiella sp. IR21 was also utilized as a biocatalyst to improve the electrical performance of a conventional MFC reactor. A single chamber, air-cathode MFC was fed with reject wastewater (10,000 mg L(-1) COD) from a H2 fermentation reactor. The average voltage, current density, and power density were 142.9 ± 25.74 mV, 60.5 ± 11.61 mA m(-2), and 8.9 ± 3.65 mW m(-2), respectively, in the MFC without inoculation of Klebsiella sp. IR21. However, these electrical performances of the MFC were significantly increased to 204.7 ± 40.24 mV, 87.5 ± 17.20 mA m(-2), and 18.6 ± 7.23 mW m(-2), respectively, with inoculation of Klebsiella sp. IR21. The results indicate that Klebsiella sp. IR21 can be utilized as a biocatalyst for enhancement of electrical performance in MFC systems.

  1. Modeling and Implementation of a 1 kW, Air Cooled HTPEM Fuel Cell in a Hybrid Electrical Vehicle

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Ashworth, Leanne; Remón, Ian Natanael

    2008-01-01

    , was implemented in a small electrical vehicle. A dynamic model was developed using Matlab-Simulink to describe the system characteristics, select operating conditions and to size system components. Preheating of the fuel cell stack with electrical resistors was investigated and found to be an unrealistic approach...

  2. Critical Evaluation of Air-Liquid Interface Cell Exposure Systems for In Vitro Assessment of Atmospheric Pollutants##

    Science.gov (United States)

    Conventional in vitro exposure studies of airborne pollutants involve, for example, the addition of particulate matter (PM) or PM extracts to the cell culture medium, or the bubbling of gases into the culture medium; these methods alter the pollutant’s physical and chemical...

  3. Treatment of poly(ethylene terephthalate) foils by atmospheric pressure air dielectric barrier discharge and its influence on cell growth

    Czech Academy of Sciences Publication Activity Database

    Kuzminova, A.; Vandrovcová, Marta; Shelemin, A.; Kylián, O.; Choukourov, A.; Hanuš, J.; Bačáková, Lucie; Slavínská, D.; Biederman, H.

    2015-01-01

    Roč. 357, part A (2015), s. 689-695 ISSN 0169-4332 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:67985823 Keywords : plasma treatment * DBD plasma * cells growth Subject RIV: JJ - Other Materials Impact factor: 3.150, year: 2015

  4. Long Term Stability Investigation of Solid Oxide Electrolysis Cell with Infiltrated Porous YSZ Air Electrode Under High Current

    DEFF Research Database (Denmark)

    Veltzé, Sune; Ovtar, Simona; Simonsen, Søren Bredmose

    2015-01-01

    The increased interest in stable and low cost electrodes for solid oxide cells (SOC) has driven the research of electrode preparation to infiltration of catalyst material into porous backbone material. The infiltration method enables a reduction of amount of catalyst material and increases its ac...

  5. Carbon-Nanotube-Supported Bio-Inspired Nickel Catalyst and Its Integration in Hybrid Hydrogen/Air Fuel Cells.

    Science.gov (United States)

    Gentil, Solène; Lalaoui, Noémie; Dutta, Arnab; Nedellec, Yannig; Cosnier, Serge; Shaw, Wendy J; Artero, Vincent; Le Goff, Alan

    2017-02-06

    A biomimetic nickel bis-diphosphine complex incorporating the amino acid arginine in the outer coordination sphere was immobilized on modified carbon nanotubes (CNTs) through electrostatic interactions. The functionalized redox nanomaterial exhibits reversible electrocatalytic activity for the H 2 /2 H + interconversion from pH 0 to 9, with catalytic preference for H 2 oxidation at all pH values. The high activity of the complex over a wide pH range allows us to integrate this bio-inspired nanomaterial either in an enzymatic fuel cell together with a multicopper oxidase at the cathode, or in a proton exchange membrane fuel cell (PEMFC) using Pt/C at the cathode. The Ni-based PEMFC reaches 14 mW cm -2 , only six-times-less as compared to full-Pt conventional PEMFC. The Pt-free enzyme-based fuel cell delivers ≈2 mW cm -2 , a new efficiency record for a hydrogen biofuel cell with base metal catalysts. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Planar air-breathing micro-direct methanol fuel cell stacks based on micro-electronic-mechanical-system technology

    Science.gov (United States)

    Cao, Jianyu; Zou, Zhiqing; Huang, Qinghong; Yuan, Ting; Li, Zhilin; Xia, Baojia; Yang, Hui

    To meet the demands for high power micro-electronic devices, two silicon-based micro-direct methanol fuel cell (μDMFC) stacks consisting of six individual cells with two different anode flow fields were designed, fabricated and evaluated. Micro-electronic-mechanical-system (MEMS) technology was used to fabricate both flow field plate and fuel distribution plate on the silicon wafer. Experimental results show that either an individual cell or a stack with double serpentine-type flow fields presents better cell performance than those with pin-type flow fields. A μDMFC stack with double serpentine-type flow fields generates a peak output power of ca. 151 mW at a working voltage of 1.5 V, corresponding to an average power density of ca. 17.5 mW cm -2, which is ca. 20.7% higher than that with pin-type flow fields. The volume and weight of the stacks are only 5.3 cm 3 and 10.7 g, respectively. Such small stacks could be used as power sources for micro-electronic devices.

  7. From lithium to sodium: cell chemistry of room temperature sodium–air and sodium–sulfur batteries

    Directory of Open Access Journals (Sweden)

    Philipp Adelhelm

    2015-04-01

    Full Text Available Research devoted to room temperature lithium–sulfur (Li/S8 and lithium–oxygen (Li/O2 batteries has significantly increased over the past ten years. The race to develop such cell systems is mainly motivated by the very high theoretical energy density and the abundance of sulfur and oxygen. The cell chemistry, however, is complex, and progress toward practical device development remains hampered by some fundamental key issues, which are currently being tackled by numerous approaches. Quite surprisingly, not much is known about the analogous sodium-based battery systems, although the already commercialized, high-temperature Na/S8 and Na/NiCl2 batteries suggest that a rechargeable battery based on sodium is feasible on a large scale. Moreover, the natural abundance of sodium is an attractive benefit for the development of batteries based on low cost components. This review provides a summary of the state-of-the-art knowledge on lithium–sulfur and lithium–oxygen batteries and a direct comparison with the analogous sodium systems. The general properties, major benefits and challenges, recent strategies for performance improvements and general guidelines for further development are summarized and critically discussed. In general, the substitution of lithium for sodium has a strong impact on the overall properties of the cell reaction and differences in ion transport, phase stability, electrode potential, energy density, etc. can be thus expected. Whether these differences will benefit a more reversible cell chemistry is still an open question, but some of the first reports on room temperature Na/S8 and Na/O2 cells already show some exciting differences as compared to the established Li/S8 and Li/O2 systems.

  8. Source apportionment of Beijing air pollution during a severe winter haze event and associated pro-inflammatory responses in lung epithelial cells

    Science.gov (United States)

    Liu, Qingyang; Baumgartner, Jill; Zhang, Yuanxun; Schauer, James J.

    2016-02-01

    Air pollution is a leading risk factor for the disease burden in China and globally. Few epidemiologic studies have characterized the particulate matter (PM) components and sources that are most responsible for adverse health outcomes, particularly in developing countries. In January 2013, a severe haze event occurred over 25 days in urban Beijing, China. Ambient fine particulate matter (PM2.5) was collected at a central urban site in Beijing from January 16-31, 2013. We analyzed the samples for water soluble ions, metals, elemental carbon (EC), organic carbon (OC), and individual organic molecular markers including n-alkanes, hopanes, PAHs and sterols. Chemical components were used to quantify the source contributions to PM2.5 using the chemical mass balance (CMB) model by the conversion of the OC estimates combined with inorganic secondary components (e.g. NH4+, SO42-, NO3-). Water extracts of PM were exposed to lung epithelial cells, and supernatants recovered from cell cultures were assayed for the pro-inflammatory cytokines by a quantitative ELLSA method. Linear regression models were used to estimate the associations between PM sources and components with pro-inflammatory responses in lung epithelial cells following 24-hrs and 48-hrs of exposure. The largest contributors to PM2.5 during the monitoring period were inorganic secondary ions (53.2% and 54.0% on haze and non-haze days, respectively). Other organic matter (OM) contributed to a larger proportion of PM2.5 during haze days (16.9%) compared with non-haze days (12.9%), and coal combustion accounted for 10.9% and 8.7% on haze and non-haze days, respectively. We found PM2.5 mass and specific sources (e.g. coal combustion, traffic emission, dust, other OM, and inorganic secondary ions) were highly associated with inflammatory responses of lung epithelial cells. Our results showed greater responses in the exposure to 48-hr PM2.5 mass and its sources compared to 24-hr PM exposure, and that secondary and coal

  9. Activation of Pulmonary Dendritic Cells and Th2-Type Inflammatory Responses on Instillation of Engineered, Environmental Diesel Emission Source or Ambient Air Pollutant Particles in vivo

    Science.gov (United States)

    Bezemer, Gillina F.G.; Bauer, Stephen M.; Oberdörster, Günter; Breysse, Patrick N.; Pieters, Raymond H.H.; Georas, Steve N.; Williams, Marc A.

    2011-01-01

    The biological effects of acute particulate air pollution exposure in host innate immunity remain obscure and have relied largely on in vitro models. We hypothesized that single acute exposure to ambient or engineered particulate matter (PM) in the absence of other secondary stimuli would activate lung dendritic cells (DC) in vivo and provide information on the early immunological events of PM exposure and DC activation in a mouse model naïve to prior PM exposure. Activation of purified lung DC was studied following oropharyngeal instillation of ambient particulate matter (APM). We compared the effects of APM exposure with that of diesel-enriched PM (DEP), carbon black particles (CBP) and silver nanoparticles (AgP). We found that PM species induced variable cellular infiltration in the lungs and only APM exposure induced eosinophilic infiltration. Both APM and DEP activated pulmonary DC and promoted a Th2-type cytokine response from naïve CD4+ T cells ex vivo. Cultures of primary peribronchial lymph node cells from mice exposed to APM and DEP also displayed a Th2-type immune response ex vivo. We conclude that exposure of the lower airway to various PM species induces differential immunological responses and immunomodulation of DC subsets. Environmental APM and DEP activated DC in vivo and provoked a Th2 response ex vivo. By contrast, CBP and AgP induced altered lung tissue barrier integrity but failed to stimulate CD4+ T cells as effectively. Our work suggests that respirable pollutants activate the innate immune response with enhanced DC activation, pulmonary inflammation and Th2-immune responsiveness. PMID:21099199

  10. Instant power generation from an air-breathing paper and pencil based bacterial bio-fuel cell.

    Science.gov (United States)

    Veerubhotla, Ramya; Bandopadhyay, Aditya; Das, Debabrata; Chakraborty, Suman

    2015-06-21

    We present a low-cost, disposable microbial fuel cell fabricated on a paper based platform, having a start-up time of 10 s. The platform deploys ordinary pencil strokes for graphite electrode deposition. The device uses a membrane-less design in a one-time injection (OTI) mode or a continuous capillary driven flow mode (CPF), where oxygen from the atmosphere is used up at the cathode for water formation, leading to the generation of bioelectricity. The performance of the fuel cell is evaluated using two bacterial strains, namely, Pseudomonas aeruginosa IIT BT SS1 and Shewanella putrefaciens. This flexible device is shown to retain bacteria for a period of at least one hour, resulting in the generation of almost 0.4 V using P. aeruginosa and a maximum current of 18 μA using S. putrefaciens without the use of any additional catalysts.

  11. Nuclear abnormalities in cells from nasal epithelium: a promising assay to evaluate DNA damage related to air pollution in infants

    OpenAIRE

    Michelle Mergener; Cláudia R. Rhoden; Sérgio L. Amantéa

    2014-01-01

    OBJECTIVES: This study intends to provide a quick, easy, and inexpensive way to assess nuclear abnormalities such as micronuclei and bud frequencies; binucleated, karyorrhectic, karyolytic, pycnotic, and condensed chromatin cells in nasal scrapings of infants, which are particularly important for conducting genotoxic studies related to the inhaled atmosphere in pediatric populations. METHODS: Nasal swab samples were collected from 40 infants under 12 months of age using a small cytobrush...

  12. Analysis of gene expression changes in A549 cells induced by organic compounds from respirable air particles

    Czech Academy of Sciences Publication Activity Database

    Líbalová, Helena; Krčková, S.; Uhlířová, Kateřina; Kléma, J.; Ciganek, M.; Rössner ml., Pavel; Šrám, Radim; Vondráček, J.; Machala, M.; Topinka, Jan

    2014-01-01

    Roč. 770, DEC 2014 (2014), s. 94-105 ISSN 0027-5107 R&D Projects: GA ČR GAP503/11/0142; GA ČR(CZ) GBP503/12/G147 Institutional support: RVO:68378041 Keywords : Ah receptor * gene expression profile * A549 cells Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 3.680, year: 2014

  13. Can Youthful Mesenchymal Stem Cells from Wharton’s Jelly Bring a Breath of Fresh Air for COPD?

    Directory of Open Access Journals (Sweden)

    Andrzej M. Janczewski

    2017-11-01

    Full Text Available Chronic obstructive pulmonary disease (COPD is a major global cause of morbidity and mortality, projected to become the 3rd cause of disease mortality worldwide by 2020. COPD is characterized by persistent and not fully reversible airflow limitation that is usually progressive and is associated with an abnormal chronic inflammatory response of the lung to noxious agents including cigarette smoke. Currently available therapeutic strategies aim to ease COPD symptoms but cannot prevent its progress or regenerate physiological lung structure or function. The urgently needed new approaches for the treatment of COPD include stem cell therapies among which transplantation of mesenchymal stem cells derived from Wharton’s jelly (WJ-MSCs emerges as a promising therapeutic strategy because of the unique properties of these cells. The present review discusses the main biological properties of WJ-MSCs pertinent to their potential application for the treatment of COPD in the context of COPD pathomechanisms with emphasis on chronic immune inflammatory processes that play key roles in the development and progression of COPD.

  14. Investigations of Pulmonary Epithelial Cell Damage due to Air-Liquid Interfacial Stresses in a Microgravity Environment

    Science.gov (United States)

    Gaver, Donald P., III; Bilek, A. M.; Kay, S.; Dee, K. C.

    2004-01-01

    Pulmonary airway closure is a potentially dangerous event that can occur in microgravity environments and may result in limited gas exchange for flight crew during long-term space flight. Repetitive airway collapse and reopening subjects the pulmonary epithelium to large, dynamic, and potentially injurious mechanical stresses. During ventilation at low lung volumes and pressures, airway instability leads to repetitive collapse and reopening. During reopening, air must progress through a collapsed airway, generating stresses on the airway walls, potentially damaging airway tissues. The normal lung can tolerate repetitive collapse and reopening. However, combined with insufficient or dysfunctional pulmonary surfactant, repetitive airway collapse and reopening produces severe lung injury. Particularly at risk is the pulmonary epithelium. As an important regulator of lung function and physiology, the degree of pulmonary epithelial damage influences the course and outcome of lung injury. In this paper we present experimental and computational studies to explore the hypothesis that the mechanical stresses associated with airway reopening inflict injury to the pulmonary epithelium.

  15. Air Pollution

    OpenAIRE

    Ababsa, Myriam

    2014-01-01

    The human costs of air pollution are considerable in Jordan. According to a report published in 2000 by the World Bank under the Mediterranean Environmental Technical Assistance Program (METAP), approximately 600 people die prematurely each year in Jordan because of urban pollution. 50-90% of air pollution in Jordanian towns is caused by road traffic. Readings taken in 2007 by Jordanian researchers showed that levels of black carbon particles in the air were higher in urban areas (caused by v...

  16. Efficient and Air-Stable Planar Perovskite Solar Cells Formed on Graphene-Oxide-Modified PEDOT:PSS Hole Transport Layer

    Science.gov (United States)

    Luo, Hui; Lin, Xuanhuai; Hou, Xian; Pan, Likun; Huang, Sumei; Chen, Xiaohong

    2017-10-01

    As a hole transport layer, PEDOT:PSS usually limits the stability and efficiency of perovskite solar cells (PSCs) due to its hygroscopic nature and inability to block electrons. Here, a graphene-oxide (GO)-modified PEDOT:PSS hole transport layer was fabricated by spin-coating a GO solution onto the PEDOT:PSS surface. PSCs fabricated on a GO-modified PEDOT:PSS layer exhibited a power conversion efficiency (PCE) of 15.34%, which is higher than 11.90% of PSCs with the PEDOT:PSS layer. Furthermore, the stability of the PSCs was significantly improved, with the PCE remaining at 83.5% of the initial PCE values after aging for 39 days in air. The hygroscopic PSS material at the PEDOT:PSS surface was partly removed during spin-coating with the GO solution, which improves the moisture resistance and decreases the contact barrier between the hole transport layer and perovskite layer. The scattered distribution of the GO at the PEDOT:PSS surface exhibits superior wettability, which helps to form a high-quality perovskite layer with better crystallinity and fewer pin holes. Furthermore, the hole extraction selectivity of the GO further inhibits the carrier recombination at the interface between the perovskite and PEDOT:PSS layers. Therefore, the cooperative interactions of these factors greatly improve the light absorption of the perovskite layer, the carrier transport and collection abilities of the PSCs, and especially the stability of the cells.

  17. Physicochemical characterization of ambient PM2.5in Tehran air and its potential cytotoxicity in human lung epithelial cells (A549).

    Science.gov (United States)

    MohseniBandpi, Anoushiravan; Eslami, Akbar; Shahsavani, Abbas; Khodagholi, Fariba; Alinejad, Abdolazim

    2017-09-01

    As air pollution is a major problem in Tehran, this study aimed to investigate the physicochemical characterization of the water-soluble and organic contents of ambient PM 2.5 in Tehran and determine its in vitro toxicological impact on human lung epithelial cells (A549). A total of 11 sampling stations were selected, including three categories: traffic, urban, and suburban. All sampling was carried out in the spring and summer of 2015. Ion chromatography (IC), inductively coupled plasma atomic emission spectroscopy (ICP-AES), and GC-MS were used to analyze ionic compounds, heavy metals, and polycyclic aromatic hydrocarbons (PAHs), respectively, and an ELISA reader was used for cytotoxicity analysis. The most prevalent ionic species found for all three categories was SO 4 2- . PAH concentrations were 43.45±32.71, 50.51±37.27, and 29.13±33.29ng/m 3 for traffic, urban, and suburban stations, respectively. For all sampling stations, Al and Fe had the highest values among the investigated heavy metals. Cell viability measurements, carried out using the MTT assay, showed that all three categories of samples cause cytotoxicity, although the urban station samples showed higher cytotoxicity than those from the other stations (p˂0.05). Based on the results of the present study, organic compounds and insoluble particles could be the main causes of cytotoxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Modeling Frequency Response of Photoacoustic Cells using FEM for Determination of N-heptane Contamination in Air: Experimental Validation

    Directory of Open Access Journals (Sweden)

    Lars Duggen

    2012-04-01

    Full Text Available We briefly present the basic principle of the photoacoustic effect in gases. We present the equations and boundary conditions governing the acoustic field generated by the absorption of a modulated laser beam. We solve these equations using Finite Element Methods and compare the results with experiment. We find that apparently there are effects not taken into account in the classic acoustic theory as we find a larger damping than theory predicts. However, we see that these effects have significant negative influence on the quality factor of the cell and thereby the performance limit.

  19. Carbon-Nanotube-Supported Bio-Inspired Nickel Catalyst and Its Integration in Hybrid Hydrogen/Air Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Gentil, Solène [Univ. Grenoble Alpes, CNRS, DCM UMR 5250, 38000 Grenoble France; Laboratoire de Chimie et Biologie des Métaux, Univ. Grenoble Alpes, CNRS UMR5249, CEA, 38000 Grenoble France; Lalaoui, Noémie [Univ. Grenoble Alpes, CNRS, DCM UMR 5250, 38000 Grenoble France; Dutta, Arnab [Pacific Northwest National Laboratory, Richland WA 99532 USA; Current address: Chemistry Department, IIT Gandhinagar, Gujarat 382355 India; Nedellec, Yannig [Univ. Grenoble Alpes, CNRS, DCM UMR 5250, 38000 Grenoble France; Cosnier, Serge [Univ. Grenoble Alpes, CNRS, DCM UMR 5250, 38000 Grenoble France; Shaw, Wendy J. [Pacific Northwest National Laboratory, Richland WA 99532 USA; Artero, Vincent [Laboratoire de Chimie et Biologie des Métaux, Univ. Grenoble Alpes, CNRS UMR5249, CEA, 38000 Grenoble France; Le Goff, Alan [Univ. Grenoble Alpes, CNRS, DCM UMR 5250, 38000 Grenoble France

    2017-01-12

    A biomimetic nickel bis-diphosphine complex incorporating the amino-acid arginine in the outer coordination sphere, was immobilized on modified single-wall carbon nanotubes (SWCNTs) through electrostatic interactions. The sur-face-confined catalyst is characterized by a reversible 2-electron/2-proton redox process at potentials close to the equibrium potential of the H+/H2 couple. Consequently, the functionalized redox nanomaterial exhibits reversible electrocatalytic activity for the H2/2H+ interconversion over a broad range of pH. This system exhibits catalytic bias, analogous to hydrogenases, resulting in high turnover frequencies at low overpotentials for electrocatalytic H2 oxida-tion between pH 0 and 7. This allowed integrating such bio-inspired nanomaterial together with a multicopper oxi-dase at the cathode side in a hybrid bioinspired/enzymatic hydrogen fuel cell. This device delivers ~2 mW cm–2 with an open-circuit voltage of 1.0 V at room temperature and pH 5, which sets a new efficiency record for a bio-related hydrogen fuel cell with base metal catalysts.

  20. Air lock

    International Nuclear Information System (INIS)

    Palkovich, P.; Gruber, J.; Madlener, W.

    1974-01-01

    The patent refers to an air lock system preferably for nuclear stations for the transport of heavy loads by means of a trolley on rails. For opening and closing of the air lock parts of the rails are removed, e.g. by a second rail system perpendicular to the main rails. (P.K.)

  1. Temporal-spatial analysis of U.S.-Mexico border environmental fine and coarse PM air sample extract activity in human bronchial epithelial cells

    International Nuclear Information System (INIS)

    Lauer, Fredine T.; Mitchell, Leah A.; Bedrick, Edward; McDonald, Jacob D.; Lee, Wen-Yee; Li, Wen-Whai; Olvera, Hector; Amaya, Maria A.; Berwick, Marianne; Gonzales, Melissa; Currey, Robert; Pingitore, Nicholas E.

    2009-01-01

    Particulate matter less than 10 μm (PM10) has been shown to be associated with aggravation of asthma and respiratory and cardiopulmonary morbidity. There is also great interest in the potential health effects of PM2.5. Particulate matter (PM) varies in composition both spatially and temporally depending on the source, location and seasonal condition. El Paso County which lies in the Paso del Norte airshed is a unique location to study ambient air pollution due to three major points: the geological land formation, the relatively large population and the various sources of PM. In this study, dichotomous filters were collected from various sites in El Paso County every 7 days for a period of 1 year. The sampling sites were both distant and near border crossings, which are near heavily populated areas with high traffic volume. Fine (PM2.5) and Coarse (PM10-2.5) PM filter samples were extracted using dichloromethane and were assessed for biologic activity and polycyclic aromatic (PAH) content. Three sets of marker genes human BEAS2B bronchial epithelial cells were utilized to assess the effects of airborne PAHs on biologic activities associated with specific biological pathways associated with airway diseases. These pathways included in inflammatory cytokine production (IL-6, IL-8), oxidative stress (HMOX-1, NQO-1, ALDH3A1, AKR1C1), and aryl hydrocarbon receptor (AhR)-dependent signaling (CYP1A1). Results demonstrated interesting temporal and spatial patterns of gene induction for all pathways, particularly those associated with oxidative stress, and significant differences in the PAHs detected in the PM10-2.5 and PM2.5 fractions. Temporally, the greatest effects on gene induction were observed in winter months, which appeared to correlate with inversions that are common in the air basin. Spatially, the greatest gene expression increases were seen in extracts collected from the central most areas of El Paso which are also closest to highways and border crossings.

  2. Anolyte recycling enhanced bioelectricity generation of the buffer-free single-chamber air-cathode microbial fuel cell.

    Science.gov (United States)

    Ren, Yueping; Chen, Jinli; Shi, Yugang; Li, Xiufen; Yang, Na; Wang, Xinhua

    2017-11-01

    Anolyte acidification is an inevitable restriction for the bioelectricity generation of buffer-free microbial fuel cells (MFCs). In this work, acidification of the buffer-free KCl anolyte has been thoroughly eliminated through anolyte recycling. The accumulated HCO 3 - concentration in the recycled KCl anolyte was above 50mM, which played as natural buffer and elevated the anolyte pH to above 8. The maximum power density (P max ) increased from 322.9mWm -2 to 527.2mWm -2 , which is comparable with the phosphate buffered MFC. Besides Geobacter genus, the gradually increased anolyte pH and conductivity induced the growing of electrochemically active Geoalkalibacter genus, in the anode biofilm. Anolyte recycling is a feasible strategy to strengthen the self-buffering capacity of buffer-free MFCs, thoroughly eliminate the anolyte acidification and prominently enhance the electric power. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Scalable air cathode microbial fuel cells using glass fiber separators, plastic mesh supporters, and graphite fiber brush anodes

    KAUST Repository

    Zhang, Xiaoyuan

    2011-01-01

    The combined use of brush anodes and glass fiber (GF1) separators, and plastic mesh supporters were used here for the first time to create a scalable microbial fuel cell architecture. Separators prevented short circuiting of closely-spaced electrodes, and cathode supporters were used to avoid water gaps between the separator and cathode that can reduce power production. The maximum power density with a separator and supporter and a single cathode was 75±1W/m3. Removing the separator decreased power by 8%. Adding a second cathode increased power to 154±1W/m3. Current was increased by connecting two MFCs connected in parallel. These results show that brush anodes, combined with a glass fiber separator and a plastic mesh supporter, produce a useful MFC architecture that is inherently scalable due to good insulation between the electrodes and a compact architecture. © 2010 Elsevier Ltd.

  4. Effects on Air Pollution and Regional Climate of Producing and Using Hydrogen in Fuel Cells in all U.S. OnroadVehicles

    Science.gov (United States)

    Jacobson, M. Z.; Colella, W. G.; Golden, D. M.

    2004-12-01

    The purpose of this study was to examine the potential effects on U.S. air pollution and regional climate of switching the current U.S. fleet of onroad motor vehicles to hydrogen fuel-cell vehicles, where hydrogen was produced by (1) steam-reforming of methane, (2) wind energy, or (3) coal gasification. An additional scenario in which the U.S. fleet was switched to gasoline-electric hybrid vehicles was also examined. The model used was GATOR-GCMOM, a global-through-urban-scale nested and parallelized gas, aerosol, transport, radiation, general-circulation, mesoscale, and ocean model. U.S. emission data for the baseline case were obtained from the U.S. National Emission Inventory, which considers 370,000 stack and fugitive sources, 250,000 area sources, and 1700 categories of onroad and nonroad vehicular sources (including motorcycles, passenger vehicles, trucks, recreational vehicles, construction vehicles, farm vehicles, industrial vehicles, etc.). Emission inventories for each of the three hydrogen scenarios were prepared following a process chain analysis that accounted for energy inputs and pollution outputs during all stages of hydrogen and fossil-fuel production, distribution, storage, and end-use. Emitted pollutants accounted for included CO, CO2, H2, H2O, CH4, speciated ROGs, NOx, NH3, SOx, and speciated particulate matter. Results from the first scenario suggest that switching vehicles in the U.S. to hydrogen produced by steam-reforming of methane may reduce emission of NOx, reactive hydrocarbons, CO, CO2, BC, NO3-, and NH4+, but increase CH4, H2, and SO2 (slightly).The switch may also decrease O3 over most of the U.S. but short-term near-surfaces increases may occur over low-vegetated cities (e.g., in Los Angeles and along the Boston-Washington corridor) due to loss of NOx that otherwise titrates O3. The switch is also estimated to decrease PAN, HCHO, and several other pollutants formed in the atmosphere. Isoprene may increase since fewer oxidants (OH, O3

  5. Surface-oxidized cobalt phosphide used as high efficient electrocatalyst in activated carbon air-cathode microbial fuel cell

    Science.gov (United States)

    Yang, Tingting; Wang, Zhong; Li, Kexun; Liu, Yi; Liu, Di; Wang, Junjie

    2017-09-01

    Herein, we report a simplistic method to fabricate the surface-oxidized cobalt phosphide (CoP) nanocrystals (NCs), which is used as electrocatalyst for oxygen reduction reaction (ORR) in microbial fuel cell (MFC) for the first time. The corallite-like CoP NCs are successfully prepared by a hydrothermal reaction following a phosphating treatment in N2 atmosphere. When used as an ORR catalyst, cobalt phosphide shows comparable onset potential, inferior resistance, as well as a small Tafel slope with long-term stability in neutral media. The maximum power density of MFC embellished with 10% CoP reached 1914.4 ± 59.7 mW m-2, which is 108.5% higher than the control. The four-electron pathway, observed by the RDE, plays a crucial role in electrochemical catalytic activity. In addition, material characterizations indicate that the surface oxide layer (CoOx) around the metallic CoP core is important and beneficial for ORR. Accordingly, it can be expected that the as-synthesized CoP will be a promising candidate of the non-precious metal ORR electrocatalysts for electrochemical energy applications.

  6. FePO4based single chamber air-cathode microbial fuel cell for online monitoring levofloxacin.

    Science.gov (United States)

    Zeng, Libin; Li, Xinyong; Shi, Yueran; Qi, Yefei; Huang, Daqiong; Tadé, Moses; Wang, Shaobin; Liu, Shaomin

    2017-05-15

    A bio-electrochemical strategy was developed for constructing a simple and sensitive levofloxacin (LEV) sensor based on a single chamber microbial fuel cell (SC-MFC) using FePO 4 nanoparticles (NPs) as the cathode catalyst instead of traditional Pt/C. In this assembled sensor device, FePO 4 NPs dramatically promoted the electrooxidation of oxygen on the cathode, which helps to accelerate the voltage output from SC-MFC and can provide a powerful guarantee for LEV detection. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to fully characterize the FePO 4 NPs. Under the optimized COD condition (3mM), the LEV with a concentration range of 0.1-1000µg/L could be detected successfully, and exhibited the excellent linear interval in the concentration range of 0.1-100µg/L. During this range of concentrations of LEV, a temporary effect on the anode of exoelectrogenic bacterial in less than 10min could occur, and then came back to the normal. It exhibited a long-term stability, maintaining the stable electricity production for 14 months of continuous running. Besides, the detection mechanism was investigated by quantum chemical calculation using density functional theory (DFT). Copyright © 2016. Published by Elsevier B.V.

  7. An Air-Stable DPP-thieno-TTF Copolymer for Single-Material Solar Cell Devices and Field Effect Transistors.

    Science.gov (United States)

    Arumugam, Sasikumar; Cortizo-Lacalle, Diego; Rossbauer, Stephan; Hunter, Simon; Kanibolotsky, Alexander L; Inigo, Anto R; Lane, Paul A; Anthopoulos, Thomas D; Skabara, Peter J

    2015-12-30

    Following an approach developed in our group to incorporate tetrathiafulvalene (TTF) units into conjugated polymeric systems, we have studied a low band gap polymer incorporating TTF as a donor component. This polymer is based on a fused thieno-TTF unit that enables the direct incorporation of the TTF unit into the polymer, and a second comonomer based on the diketopyrrolopyrrole (DPP) molecule. These units represent a donor-acceptor copolymer system, p(DPP-TTF), showing strong absorption in the UV-visible region of the spectrum. An optimized p(DPP-TTF) polymer organic field effect transistor and a single material organic solar cell device showed excellent performance with a hole mobility of up to 5.3 × 10(-2) cm(2)/(V s) and a power conversion efficiency (PCE) of 0.3%, respectively. Bulk heterojunction organic photovoltaic devices of p(DPP-TTF) blended with phenyl-C71-butyric acid methyl ester (PC71BM) exhibited a PCE of 1.8%.

  8. Solid oxide fuel cell power plant having a fixed contact oxidation catalyzed section of a multi-section cathode air heat exchanger

    Science.gov (United States)

    Saito, Kazuo; Lin, Yao

    2015-02-17

    The multi-section cathode air heat exchanger (102) includes at least a first heat exchanger section (104), and a fixed contact oxidation catalyzed section (126) secured adjacent each other in a stack association. Cool cathode inlet air flows through cool air channels (110) of the at least first (104) and oxidation catalyzed sections (126). Hot anode exhaust flows through hot air channels (124) of the oxidation catalyzed section (126) and is combusted therein. The combusted anode exhaust then flows through hot air channels (112) of the first section (104) of the cathode air heat exchanger (102). The cool and hot air channels (110, 112) are secured in direct heat exchange relationship with each other so that temperatures of the heat exchanger (102) do not exceed 800.degree. C. to minimize requirements for using expensive, high-temperature alloys.

  9. Characterization of bacterial and archaeal communities in air-cathode microbial fuel cells, open circuit and sealed-off reactors

    KAUST Repository

    Chehab, Noura A.

    2013-06-18

    A large percentage of organic fuel consumed in a microbial fuel cell (MFC) is lost as a result of oxygen transfer through the cathode. In order to understand how this oxygen transfer affects the microbial community structure, reactors were operated in duplicate using three configurations: closed circuit (CC; with current generation), open circuit (OC; no current generation), and sealed off cathodes (SO; no current, with a solid plate placed across the cathode). Most (98 %) of the chemical oxygen demand (COD) was removed during power production in the CC reactor (maximum of 640 ± 10 mW/m 2), with a low percent of substrate converted to current (coulombic efficiency of 26.5 ± 2.1 %). Sealing the cathode reduced COD removal to 7 %, but with an open cathode, there was nearly as much COD removal by the OC reactor (94.5 %) as the CC reactor. Oxygen transfer into the reactor substantially affected the composition of the microbial communities. Based on analysis of the biofilms using 16S rRNA gene pyrosequencing, microbes most similar to Geobacter were predominant on the anodes in the CC MFC (72 % of sequences), but the most abundant bacteria were Azoarcus (42 to 47 %) in the OC reactor, and Dechloromonas (17 %) in the SO reactor. Hydrogenotrophic methanogens were most predominant, with sequences most similar to Methanobacterium in the CC and SO reactor, and Methanocorpusculum in the OC reactors. These results show that oxygen leakage through the cathode substantially alters the bacterial anode communities, and that hydrogenotrophic methanogens predominate despite high concentrations of acetate. The predominant methanogens in the CC reactor most closely resembled those in the SO reactor, demonstrating that oxygen leakage alters methanogenic as well as general bacterial communities. © 2013 Springer-Verlag Berlin Heidelberg.

  10. Oxidative damage induced in A549 cells by physically and chemically characterized air particulate matter (PM2.5) collected in Abidjan, Côte d'Ivoire.

    Science.gov (United States)

    Kouassi, Kouakou S; Billet, Sylvain; Garçon, Guillaume; Verdin, Anthony; Diouf, Amadou; Cazier, Fabrice; Djaman, Joseph; Courcot, Dominique; Shirali, Pirouz

    2010-05-01

    Exposure to high levels of air pollution particulate matter (PM) is strongly associated with increased pulmonary morbidity and mortality. However, the underlying mechanisms of action whereby PM cause adverse health effects are still unclear. In developing countries, like in the sub-Saharian region of Africa, people are often exposed to high PM levels. Hence, three PM(2.5) samples were collected in the District of Abidjan (Côte d'Ivoire), under rural, urban or industrial influences. Their most toxicologically relevant physical and chemical characteristics were determined--thereby showing that most of them were equal or smaller than 2.5 microm--and the influence of both natural (Ca, Na, Mg, Ti, etc.) and anthropic (Al, Fe, Mn, Cr, Pb, Zn, Cu, Ni, benzene and its derivatives, paraffins, etc.) emission sources. The toxicity induced by the three PM samples was studied through 5-bromodeoxyuridine incorporation to DNA, mitochondrial dehydrogenase activity and extracellular lactate dehydrogenase activity. Hence, effect concentrations at 10 and 50% (EC(10) and EC(50), respectively) were as follows: (i) rural PM--EC(10) = 5.91 microg cm(-2) and EC(50) = 29.55 microg cm(-2); (ii) urban PM--EC(10) = 5.45 microg cm(-2) and EC(50) = 27.23 microg cm(-2); and (iii) industrial PM--EC(10) = 6.86 microg cm(-2) and EC(50) = 34.29 microg cm(-2). Moreover, PM-induced oxidative damage in A549 cells was observed through the induction of lipid peroxidation, the alteration of superoxide dismutase activity, and the disruption of glutathione status. Both the transition metals and the organic chemicals within the three collected PM samples under study might be involved in the oxidative damage and, therefore, the toxicity they induced in A549 cells. 2009 John Wiley & Sons, Ltd.

  11. Air Pollution

    Science.gov (United States)

    ... Health Lead Mercury Mold Nanomaterials Ozone Perfluorinated Chemicals Pesticides Radon Soy Infant Formula Styrene Water Pollution Weather ... government and non-government websites covering specific environmental, biological, and chemical agents that cause indoor air pollution. ...

  12. Air lasing

    CERN Document Server

    Cheng, Ya

    2018-01-01

    This book presents the first comprehensive, interdisciplinary review of the rapidly developing field of air lasing. In most applications of lasers, such as cutting and engraving, the laser source is brought to the point of service where the laser beam is needed to perform its function. However, in some important applications such as remote atmospheric sensing, placing the laser at a convenient location is not an option. Current sensing schemes rely on the detection of weak backscattering of ground-based, forward-propagating optical probes, and possess limited sensitivity. The concept of air lasing (or atmospheric lasing) relies on the idea that the constituents of the air itself can be used as an active laser medium, creating a backward-propagating, impulsive, laser-like radiation emanating from a remote location in the atmosphere. This book provides important insights into the current state of development of air lasing and its applications.

  13. Domestic wastewater treatment and power generation in continuous flow air-cathode stacked microbial fuel cell: Effect of series and parallel configuration.

    Science.gov (United States)

    Estrada-Arriaga, Edson Baltazar; Hernández-Romano, Jesús; García-Sánchez, Liliana; Guillén Garcés, Rosa Angélica; Bahena-Bahena, Erick Obed; Guadarrama-Pérez, Oscar; Moeller Chavez, Gabriela Eleonora

    2018-05-15

    In this study, a continuous flow stack consisting of 40 individual air-cathode MFC units was used to determine the performance of stacked MFC during domestic wastewater treatment operated with unconnected individual MFC and in series and parallel configuration. The voltages obtained from individual MFC units were of 0.08-1.1 V at open circuit voltage, while in series connection, the maximum power and current density were 2500 mW/m 2 and 500 mA/m 2 (4.9 V), respectively. In parallel connection, the maximum power and current density was 5.8 mW/m 2 and 24 mA/m 2 , respectively. When the cells were not connected to each other MFC unit, the main bacterial species found in the anode biofilms were Bacillus and Lysinibacillus. After switching from unconnected to series and parallel connections, the most abundant species in the stacked MFC were Pseudomonas aeruginosa, followed by different Bacilli classes. This study demonstrated that when the stacked MFC was switched from unconnected to series and parallel connections, the pollutants removal, performance electricity and microbial community changed significantly. Voltages drops were observed in the stacked MFC, which was mainly limited by the cathodes. These voltages loss indicated high resistances within the stacked MFC, generating a parasitic cross current. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Impact of after-treatment devices and biofuels on diesel exhausts genotoxicity in A549 cells exposed at air-liquid interface.

    Science.gov (United States)

    Barraud, C; Corbière, C; Pottier, I; Estace, E; Blanchard, K; Logie, C; Lagadu, S; Kéravec, V; Pottier, D; Dionnet, F; Morin, J P; Préterre, D; André, V; Monteil, C; Sichel, F

    2017-12-01

    Using an air-liquid interface (ALI) device in dynamic conditions, we evaluated the efficiency of fuel after-treatment strategies (diesel oxidation catalysis, DOC, and diesel particulate filter, DPF, devices) and the impact of 7% and 30% rapeseed methyl esters (RME) blending on oxidative stress and genotoxicity induced in A549 lung cells after 3h exposure to whole Diesel exhausts. Oxidative stress was studied using assays of ROS production, glutathione level, catalase and superoxide-dismutase (SOD) activities. No oxidative stress and no clear differences on cytotoxicity patterns between biodiesel and standard Diesel exhausts were found. A weak but significant genotoxicity (8-oxodGuo adducts) and, for standard Diesel only, a DNA damage response (DDR) as evidenced by ƔH2AX foci, remained after DOC+DPF flowing. All together, these data could contribute to the improvement of the after treatment strategies and to health risk assessment of current diesel exhausts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Electrochemical characteriztion of the bioanode during simultaneous azo dye decolorization and bioelectricity generation in an air-cathode single chambered microbial fuel cell

    International Nuclear Information System (INIS)

    Sun Jian; Hu Yongyou; Hou Bin

    2011-01-01

    To achieve high power output based on simultaneously azo dye decolorization using microbial fuel cell (MFC), the bioanode responses during decolorization of a representative azo dye, Congo red, were investigated in an air-cathode single chambered MFC using representative electrochemical techniques. It has been found that the maximum stable voltage output was delayed due to slowly developed anode potential during Congo red decolorization, indicating that the electrons recovered from co-substrate are preferentially transferred to Congo red rather than the bioanode of the MFC and Congo red decolorization is prior to electricity generation. Addition of Congo red had a negligible effect on the Ohmic resistance (R ohm ) of the bioanode, but the charge-transfer resistance (R c ) and the diffusion resistance (R d ) were significantly influenced. The R c and R d firstly decreased then increased with increase of Congo red concentration, probably due to the fact that the Congo red and its decolorization products can act as electron shuttle for conveniently electrons transfer from bacteria to the anode at low concentration, but result in accelerated consumption of electrons at high concentration. Cyclic voltammetry results suggested that Congo red was a more favorable electron acceptor than the bioanode of the MFC. Congo red decolorization did not result in a noticeable decrease in peak catalytic current until Congo red concentration up to 900 mg l -1 . Long-term decolorization of Congo red resulted in change in catalytic active site of anode biofilm.

  16. Coal-fuelled systems for peaking power with 100% CO2 capture through integration of solid oxide fuel cells with compressed air energy storage

    Science.gov (United States)

    Nease, Jake; Adams, Thomas A.

    2014-04-01

    In this study, a coal-fuelled integrated solid oxide fuel cell (SOFC) and compressed air energy storage (CAES) system in a load-following power production scenario is discussed. Sixteen SOFC-based plants with optional carbon capture and sequestration (CCS) and syngas shifting steps are simulated and compared to a state-of-the-art supercritical pulverised coal (SCPC) plant. Simulations are performed using a combination of MATLAB and Aspen Plus v7.3. It was found that adding CAES to a SOFC-based plant can provide load-following capabilities with relatively small effects on efficiencies (1-2% HHV depending on the system configuration) and levelized costs of electricity (∼0.35 ¢ kW-1 h-1). The load-following capabilities, as measured by least-squares metrics, show that this system may utilize coal and achieve excellent load-tracking that is not adversely affected by the inclusion of CCS. Adding CCS to the SOFC/CAES system reduces measurable direct CO2 emission to zero. A seasonal partial plant shutdown schedule is found to reduce fuel consumption by 9.5% while allowing for cleaning and maintenance windows for the SOFC stacks without significantly affecting the performance of the system (∼1% HHV reduction in efficiency). The SOFC-based systems with CCS are found to become economically attractive relative to SCPC above carbon taxes of 22 ton-1.

  17. Electricity generation and microbial community structure of air-cathode microbial fuel cells powered with the organic fraction of municipal solid waste and inoculated with different seeds

    KAUST Repository

    El-Chakhtoura, Joline

    2014-08-01

    The organic fraction of municipal solid waste (OFMSW), normally exceeding 60% of the waste stream in developing countries, could constitute a valuable source of feed for microbial fuel cells (MFCs). This study tested the start-up of two sets of OFMSW-fed air-cathode MFCs inoculated with wastewater sludge or cattle manure. The maximum power density obtained was 123±41mWm-2 in the manure-seeded MFCs and 116±29mWm-2 in the wastewater-seeded MFCs. Coulombic efficiencies ranged between 24±5% (manure-seeded MFCs) and 23±2% (wastewater-seeded MFCs). Chemical oxygen demand removal was >86% in all the MFCs and carbohydrate removal >98%. Microbial community analysis using 16S rRNA gene pyrosequencing demonstrated the dominance of the phylum Firmicutes (67%) on the anode suggesting the possible role of members of this phylum in electricity generation. Principal coordinate analysis showed that the microbial community structure in replicate MFCs converged regardless of the inoculum source. This study demonstrates efficient electricity production coupled with organic treatment in OFMSW-fueled MFCs inoculated with manure or wastewater. © 2014 Elsevier Ltd.

  18. Electricity generation from real industrial wastewater using a single-chamber air cathode microbial fuel cell with an activated carbon anode.

    Science.gov (United States)

    Mohamed, Hend Omar; Obaid, M; Sayed, Enas Taha; Liu, Yang; Lee, Jinpyo; Park, Mira; Barakat, Nasser A M; Kim, Hak Yong

    2017-08-01

    This study introduces activated carbon (AC) as an effective anode for microbial fuel cells (MFCs) using real industrial wastewater without treatment or addition of external microorganism mediators. Inexpensive activated carbon is introduced as a proper electrode alternative to carbon cloth and carbon paper materials, which are considered too expensive for the large-scale application of MFCs. AC has a porous interconnected structure with a high bio-available surface area. The large surface area, in addition to the high macro porosity, facilitates the high performance by reducing electron transfer resistance. Extensive characterization, including surface morphology, material chemistry, surface area, mechanical strength and biofilm adhesion, was conducted to confirm the effectiveness of the AC material as an anode in MFCs. The electrochemical performance of AC was also compared to other anodes, i.e., Teflon-treated carbon cloth (CCT), Teflon-treated carbon paper (CPT), untreated carbon cloth (CC) and untreated carbon paper (CP). Initial tests of a single air-cathode MFC display a current density of 1792 mAm -2 , which is approximately four times greater than the maximum value of the other anode materials. COD analyses and Coulombic efficiency (CE) measurements for AC-MFC show the greatest removal of organic compounds and the highest CE efficiency (60 and 71%, respectively). Overall, this study shows a new economical technique for power generation from real industrial wastewater with no treatment and using inexpensive electrode materials.

  19. Porous metal-organic framework Cu3(BTC)2as catalyst used in air-cathode for high performance of microbial fuel cell.

    Science.gov (United States)

    Tian, Pei; Liu, Di; Li, Kexun; Yang, Tingting; Wang, Junjie; Liu, Yi; Zhang, Song

    2017-11-01

    Metal-organic framework Cu 3 (BTC) 2 , prepared by an easy hydrothermal method, was used as the oxygen-based catalyst in microbial fuel cell (MFC). The maximum power density of Cu 3 (BTC) 2 modified air-cathode MFC was 1772±15mWm -2 , almost 1.8 times higher than the control. BET results disclosed high specific surface area of 2159.7m 2 g -1 and abundant micropores structure. Regular octahedron and porous surface of Cu 3 (BTC) 2 were observed in SEM. XPS testified the existence of divalent copper in the extended 3D frameworks, which importantly acted as the Lewis-acid sites or redox centers in ORR. Additionally, the total resistance decreased by 42% from 17.60 to 10.24Ω compared with bare AC electrode. The rotating disk electrode test results showed a four-electron transfer pathway for Cu 3 (BTC) 2 , which was crucial for electrochemical catalytic activity. All the structural and electrochemical advantages make Cu 3 (BTC) 2 a promising catalyst for ORR in MFC. Copyright © 2017. Published by Elsevier Ltd.

  20. Iron-nitrogen-activated carbon as cathode catalyst to improve the power generation of single-chamber air-cathode microbial fuel cells.

    Science.gov (United States)

    Pan, Yajun; Mo, Xiaoping; Li, Kexun; Pu, Liangtao; Liu, Di; Yang, Tingting

    2016-04-01

    In order to improve the performance of microbial fuel cell (MFC), iron-nitrogen-activated carbon (Fe-N-C) as an excellent oxygen reduction reaction (ORR) catalyst was prepared here using commercial activated carbon (AC) as matrix and employed in single chamber MFC. In MFC, the maximum power density increased to 2437±55 mW m(-2), which was 2 times of that with AC. The open circuit potential (OCP) of Fe-N-C cathode (0.47) was much higher than that of AC cathode (0.21 V). The R0 of Fe-N-C decreased by 47% from 14.36 Ω (AC) to 7.6 Ω (Fe-N-C). From X-ray photoelectron spectroscopy (XPS), pyridinic nitrogen, quaternary nitrogen and iron species were present, which played an important role in the ORR performance of Fe-N-C. These results demonstrated that the as-prepared Fe-N-C material provided a potential alternative to Pt in AC air cathode MFC for relatively desirable energy generation and wastewater treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. A distributed air index based on maximum boundary rectangle over grid-cells for wireless non-flat spatial data broadcast.

    Science.gov (United States)

    Im, Seokjin; Choi, JinTak

    2014-06-17

    In the pervasive computing environment using smart devices equipped with various sensors, a wireless data broadcasting system for spatial data items is a natural way to efficiently provide a location dependent information service, regardless of the number of clients. A non-flat wireless broadcast system can support the clients in accessing quickly their preferred data items by disseminating the preferred data items more frequently than regular data on the wireless channel. To efficiently support the processing of spatial window queries in a non-flat wireless data broadcasting system, we propose a distributed air index based on a maximum boundary rectangle (MaxBR) over grid-cells (abbreviated DAIM), which uses MaxBRs for filtering out hot data items on the wireless channel. Unlike the existing index that repeats regular data items in close proximity to hot items at same frequency as hot data items in a broadcast cycle, DAIM makes it possible to repeat only hot data items in a cycle and reduces the length of the broadcast cycle. Consequently, DAIM helps the clients access the desired items quickly, improves the access time, and reduces energy consumption. In addition, a MaxBR helps the clients decide whether they have to access regular data items or not. Simulation studies show the proposed DAIM outperforms existing schemes with respect to the access time and energy consumption.

  2. Enhanced bioelectricity generation of air-cathode buffer-free microbial fuel cells through short-term anolyte pH adjustment.

    Science.gov (United States)

    Ren, Yueping; Chen, Jinli; Li, Xiufen; Yang, Na; Wang, Xinhua

    2018-04-01

    Short-term initial anolyte pH adjustment can relieve the performance deterioration of the single-chamber air-cathode buffer-free microbial fuel cell (BFMFC) caused by anolyte acidification. Adjusting the initial anolyte pH to 9 in 5 running cycles is the optimum strategy. The relative abundance of the electrochemically active Geobacter in the KCl-pH9-MFC anode biofilm increased from 59.01% to 75.13% after the short-term adjustment. The maximum power density (P max ) of the KCl-pH9-MFC was elevated from 316.4mW·m -2 to 511.6mW·m -2 , which was comparable with that of the PBS-MFC. And, after the short-term adjusting, new equilibrium between the anolyte pH and the anode biofilm electrochemical activity has been established in the BFMFC, which ensured the sustainability of the improved bioelectricity generation performance. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Improved performance of air-cathode single-chamber microbial fuel cell for wastewater treatment using microfiltration membranes and multiple sludge inoculation

    Science.gov (United States)

    Sun, Jian; Hu, Yongyou; Bi, Zhe; Cao, Yunqing

    Substantial optimization and cost reduction are required before microbial fuel cells (MFCs) can be practically applied. We show here the performance improvement of an air-cathode single-chamber MFC by using a microfiltration membrane (MFM) on the water-facing side of the cathode and using multiple aerobic sludge (AES), anaerobic sludge (ANS), and wetland sediment (WLS) as anodic inoculums. Batch test results show that the MFC with an MFM resulted in an approximately two-fold increase in maximum power density compared to the MFC with a proton exchange membrane (PEM). The Coulombic efficiency increased from 4.17% to 5.16% in comparison with the membrane-less MFC, without a significant negative effect on power generation and internal resistance. Overall performance of the MFC was also improved by using multiple sludge inoculums in the anode. The MFC inoculated with ANS + WLS produced the greatest maximal power density of 373 mW m -2 with a substantially low internal resistance of 38 Ω. Higher power density with a decreased internal resistance was also achieved in MFC inoculated with ANS + AES and ANS + AES + WLS in comparison with those inoculated with only one sludge. The MFCs inoculated with AES + ANS achieved the highest Coulombic efficiency. Over 92% COD was removed from confectionery wastewater in all tested MFCs, regardless of the membrane or inoculum used.

  4. Improved performance of air-cathode single-chamber microbial fuel cell for wastewater treatment using microfiltration membranes and multiple sludge inoculation

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Jian; Hu, Yongyou; Bi, Zhe; Cao, Yunqing [Department of Environmental Science and Engineering, South China University of Technology, Guangzhou 510006 (China)

    2009-02-15

    Substantial optimization and cost reduction are required before microbial fuel cells (MFCs) can be practically applied. We show here the performance improvement of an air-cathode single-chamber MFC by using a microfiltration membrane (MFM) on the water-facing side of the cathode and using multiple aerobic sludge (AES), anaerobic sludge (ANS), and wetland sediment (WLS) as anodic inoculums. Batch test results show that the MFC with an MFM resulted in an approximately two-fold increase in maximum power density compared to the MFC with a proton exchange membrane (PEM). The Coulombic efficiency increased from 4.17% to 5.16% in comparison with the membrane-less MFC, without a significant negative effect on power generation and internal resistance. Overall performance of the MFC was also improved by using multiple sludge inoculums in the anode. The MFC inoculated with ANS + WLS produced the greatest maximal power density of 373 mW m{sup -2} with a substantially low internal resistance of 38 {omega}. Higher power density with a decreased internal resistance was also achieved in MFC inoculated with ANS + AES and ANS + AES + WLS in comparison with those inoculated with only one sludge. The MFCs inoculated with AES + ANS achieved the highest Coulombic efficiency. Over 92% COD was removed from confectionery wastewater in all tested MFCs, regardless of the membrane or inoculum used. (author)

  5. Air conditioner

    International Nuclear Information System (INIS)

    Sato, Masaaki

    1993-01-01

    The present invention provides an air conditioner which can prevent an undesirable effects on a human body due to radon daughter nuclides in a closed space. That is, the concentration of the radon daughter nuclides in the air in the closed space is continuously measured. A necessary amount of ventilation air is determined based on the measured concentration to generate control signals. External air is introduced into the closed space by the generated control signals. With such procedures, necessary amount of external air is taken from the atmospheric air which can be regarded to have the radon daughter nuclide concentration substantially at zero, thereby enabling to reduce the concentration of the radon daughter nuclides in the closed space. As a result, undesired effects on the human body due to the radon daughter nuclides staying in the closed space can be prevented. According to simulation, the radon daughter nuclides are rapidly decreased only by ventilation only for three times or so in one hour. Accordingly, ventilation is extremely effective and convenient means as a countermeasure for the radon daughter nuclides. (I.S.)

  6. Brd4 bridges the transcriptional regulators, Aire and P-TEFb, to promote elongation of peripheral-tissue antigen transcripts in thymic stromal cells.

    Science.gov (United States)

    Yoshida, Hideyuki; Bansal, Kushagra; Schaefer, Uwe; Chapman, Trevor; Rioja, Inmaculada; Proekt, Irina; Anderson, Mark S; Prinjha, Rab K; Tarakhovsky, Alexander; Benoist, Christophe; Mathis, Diane

    2015-08-11

    Aire controls immunologic tolerance by inducing a battery of thymic transcripts encoding proteins characteristic of peripheral tissues. Its unusually broad effect is achieved by releasing RNA polymerase II paused just downstream of transcriptional start sites. We explored Aire's collaboration with the bromodomain-containing protein, Brd4, uncovering an astonishing correspondence between those genes induced by Aire and those inhibited by a small-molecule bromodomain blocker. Aire:Brd4 binding depended on an orchestrated series of posttranslational modifications within Aire's caspase activation and recruitment domain. This interaction attracted P-TEFb, thereby mobilizing downstream transcriptional elongation and splicing machineries. Aire:Brd4 association was critical for tolerance induction, and its disruption could account for certain point mutations that provoke human autoimmune disease. Our findings evoke the possibility of unanticipated immunologic mechanisms subtending the potent antitumor effects of bromodomain blockers.

  7. Natural Flow Air Cooled Photovoltaics

    Science.gov (United States)

    Tanagnostopoulos, Y.; Themelis, P.

    2010-01-01

    Our experimental study aims to investigate the improvement in the electrical performance of a photovoltaic installation on buildings through cooling of the photovoltaic panels with natural air flow. Our experimental study aims to investigate the improvement in the electrical performance of a photovoltaic installation on buildings through cooling of the photovoltaic panels with natural air flow. We performed experiments using a prototype based on three silicon photovoltaic modules placed in series to simulate a typical sloping building roof with photovoltaic installation. In this system the air flows through a channel on the rear side of PV panels. The potential for increasing the heat exchange from the photovoltaic panel to the circulating air by the addition of a thin metal sheet (TMS) in the middle of air channel or metal fins (FIN) along the air duct was examined. The operation of the device was studied with the air duct closed tightly to avoid air circulation (CLOSED) and the air duct open (REF), with the thin metal sheet (TMS) and with metal fins (FIN). In each case the experiments were performed under sunlight and the operating parameters of the experimental device determining the electrical and thermal performance of the system were observed and recorded during a whole day and for several days. We collected the data and form PV panels from the comparative diagrams of the experimental results regarding the temperature of solar cells, the electrical efficiency of the installation, the temperature of the back wall of the air duct and the temperature difference in the entrance and exit of the air duct. The comparative results from the measurements determine the improvement in electrical performance of the photovoltaic cells because of the reduction of their temperature, which is achieved by the naturally circulating air.

  8. In-situ growing NiCo2O4 nanoplatelets on carbon cloth as binder-free catalyst air-cathode for high-performance microbial fuel cells

    International Nuclear Information System (INIS)

    Cao, Chun; Wei, Liling; Wang, Gang; Shen, Jianquan

    2017-01-01

    Highlights: • NiCo 2 O 4 nanoplatelets were in-situ growing on carbon cloth as ORR catalyst in biofuel cells. • Binder-free cathode with the lower internal resistance. • Binder-free cathode was low-cost. • NiCo 2 O 4 -CFC shows better power generation performance than Pt/C. - Abstract: Air-cathode microbial fuel cells (MFCs) was one of most promising sustainable new energy device as well as an advanced sewage treatment technology, and thoroughly studies have been devoted to lower its cost and enhance its power generation. Herein, a binder-free and low-cost catalyst air-cathode was fabricated by in-situ electro-deposition of NiCo 2 O 4 nanoplatelets on carbon cloth, followed by feasible calcinations. The catalytic activity of catalyst air-cathode was optimized by varying the deposition time. And the optimal air-cathode was installed in real MFCs and exhibited distinct maximum out-put power density (645 ± 6 mW m −2 ), which was 12.96% higher than commercial Pt/C (571 ± 11 mW m −2 ). Noted that its remarkable electricity generation performance in MFCs should absolutely attributed to the well catalytic activity for oxygen reduction reaction, and more likely ascribed to its low internal resistance since binder-free catalyst air-cathode can facilitate the electron/charge transfer process. Therefore, it was an efficient strategy to improve the electricity generation performance of MFCs by using this binder-free catalyst air-cathode, which was also potential for application in many other electrochemical devices.

  9. Healthy Air Outdoors

    Science.gov (United States)

    ... lung.org > Our Initiatives > Healthy Air > Outdoor Healthy Air Outdoors The quality of the air we breathe ... families and can even shorten their lives. Outdoor Air Pollution and Health Outdoor air pollution continues to ...

  10. Oxidative Stress, DNA Damage, and Inflammation Induced by Ambient Air and Wood Smoke Particulate Matter in Human A549 and THP-1 Cell Lines

    DEFF Research Database (Denmark)

    Danielsen, Pernille Høgh; Møller, Peter; Jensen, Keld Alstrup

    2011-01-01

    Combustion of biomass and wood for residential heating and/or cooking contributes substantially to both ambient air and indoor levels of particulate matter (PM). Toxicological characterization of ambient air PM, especially related to traffic, is well advanced, whereas the toxicology of wood smoke...

  11. Air pollution

    International Nuclear Information System (INIS)

    Feugier, A.

    1996-01-01

    The air pollution results from the combustion of petroleum products, natural gas, coal, wastes and transports. Some compounds are considered as particularly pollutants: the carbon monoxide, the nitrogen oxides, the tropospheric ozone and the sulfur dioxides. Their environmental and biological effects are described. The present political guide lines concerns the combustion plants, the ozone, the wastes incineration and the vehicles emissions. The aim is at some future date to control the air quality, to reduce the volatile organic compounds emissions and to limit the sulfur rate of some petroleum products. (O.L.)

  12. An air-cell-based cushion for pressure ulcer protection remarkably reduces tissue stresses in the seated buttocks with respect to foams: finite element studies.

    Science.gov (United States)

    Levy, Ayelet; Kopplin, Kara; Gefen, Amit

    2014-02-01

    A sitting-acquired pressure ulcer (PU) is a common injury in wheelchair-bound patients. Preventative measures for the post spinal cord injury (SCI) population include prescription of a supportive thick cushion on the wheelchair, in order to better distribute loads between the buttocks and support surface (which are quantifiable using interface pressure measurements), and potentially, to minimize internal soft tissue loads (which are typically unknown). Information about the biomechanical efficacy of commercially-available structured cushion designs such as air-cell-based (ACB) cushions, gel, and honeycomb-like cushions is sparse. Considering the importance of such evaluations to patient safety and quality of life, we studied the biomechanical performances of an ACB cushion in comparison to standard, flat foam cushions with different stiffness properties. Using a set of finite element (FE) model variants, we determined the mechanical stresses in muscle, fat, and skin tissues under the ischial tuberosities during sitting. Tissue stress analyses were conducted in a reference SCI anatomy, incorporating pathoanatomical and pathophysiological changes associated with chronic SCI, including bone shape adaptation, muscle atrophy, and spasms. We found up to 57% greater immersion and 4 orders-of-magnitude lower muscle, fat, and skin tissue stresses for the ACB cushion. We also found the ACB cushion provides better protection against the aforementioned bone shape adaptation, muscle atrophy, and spasms. Hence, theoretically, the use of a suitable ACB cushion should provide longer safe sitting times for SCI patients with respect to standard foam cushions. Copyright © 2013 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.

  13. Deep tissue loads in the seated buttocks on an off-loading wheelchair cushion versus air-cell-based and foam cushions: finite element studies.

    Science.gov (United States)

    Peko Cohen, Lea; Gefen, Amit

    2017-12-01

    For wheelchair users, a common injury is a sitting-acquired pressure ulcer (PU) which typically onsets near the interface between the ischial tuberosity (IT) and the overlying soft tissues. The risk of developing PUs can be reduced considerably if an adequate cushion is placed on the wheelchair in order to protect tissues from PUs by minimising interface mechanical loads between the body and cushion and also, exposure to internal soft tissue loads. In this work, we studied the biomechanical performances of an off-loading (OL) cushion with limited adjustability, in comparison to a standard foam cushion and a fully adjustable air-cell-based (ACB) cushion. These different cushion design approaches were methodologically and quantitatively analysed and compared here using a finite element (FE) modelling framework. We determined the internal mechanical deformations, strains and stresses in soft tissues of the seated buttocks during symmetric sitting, in a specific anatomy of a person with a spinal cord injury that was acquired during sitting in an open, magnetic resonance imaging configuration. Our results have shown that strains and stresses in muscle, fat and skin tissues are orders of magnitude lower for the ACB cushion with respect to the standard foam and OL cushions. The OL cushion design has taken the approach of protecting at-risk sites of the buttocks by transferring local internal tissue loads away from the ITs and towards the greater trochanters, at the price of increasing exposure to internal tissue loads at sites other than the ITs. The ACB cushion design, however, has taken a different approach, that is, immersion and envelopment of the entire buttocks structure, which is useful for minimising the exposure to internal tissue loads throughout the whole buttocks. Quantifying performances of wheelchair cushions using FE modelling provides insights into deep tissue loads, which is essential for informed decision-making in developing sitting solutions for

  14. The use of nylon and glass fiber filter separators with different pore sizes in air-cathode single-chamber microbial fuel cells

    KAUST Repository

    Zhang, Xiaoyuan

    2010-01-01

    Separators are needed in microbial fuel cells (MFCs) to reduce electrode spacing and preventing electrode short circuiting. The use of nylon and glass fiber filter separators in single-chamber, air-cathode MFCs was examined for their effect on performance. Larger pore nylon mesh were used that had regular mesh weaves with pores ranging from 10 to 160 μm, while smaller pore-size nylon filters (0.2-0.45 μm) and glass fiber filters (0.7-2.0 μm) had a more random structure. The pore size of both types of nylon filters had a direct and predictable effect on power production, with power increasing from 443 ± 27 to 650 ± 7 mW m-2 for pore sizes of 0.2 and 0.45 μm, and from 769 ± 65 to 941 ± 47 mW m-2 for 10 to 160 μm. In contrast, changes in pore sizes of the glass fiber filters resulted in a relatively narrow change in power (732 ± 48 to 779 ± 43 mW m-2) for pore sizes of 0.7 to 2 μm. An ideal separator should increase both power density and Coulombic efficiency (CE). However, CEs measured for the different separators were inversely correlated with power production, demonstrating that materials which reduced the oxygen diffusion into the reactor also hindered proton transport to the cathode, reducing power production through increased internal resistance. Our results highlight the need to develop separators that control oxygen transfer and facilitate proton transfer to the cathode. © 2010 The Royal Society of Chemistry.

  15. Single-Step Fabrication Using a Phase Inversion Method of Poly(vinylidene fluoride) (PVDF) Activated Carbon Air Cathodes for Microbial Fuel Cells

    KAUST Repository

    Yang, Wulin

    2014-10-14

    Air cathodes used in microbial fuel cells (MFCs) need to have high catalytic activity for oxygen reduction, but they must also be easy to manufacture, inexpensive, and watertight. A simple one-step, phase inversion process was used here to construct an inexpensive MFC cathode using a poly(vinylidene fluoride) (PVDF) binder and an activated carbon catalyst. The phase inversion process enabled cathode preparation at room temperatures, without the need for additional heat treatment, and it produced for the first time a cathode that did not require a separate diffusion layer to prevent water leakage. MFCs using this new type of cathode produced a maximum power density of 1470 ± 50 mW m–2 with acetate as a substrate, and 230 ± 10 mW m–2 with domestic wastewater. These power densities were similar to those obtained using cathodes made using more expensive materials or more complex procedures, such as cathodes with a polytetrafluoroethylene (PTFE) binder and a poly(dimethylsiloxane) (PDMS) diffusion layer, or a Pt catalyst. Even though the PVDF cathodes did not have a diffusion layer, they withstood up to 1.22 ± 0.04 m of water head (∼12 kPa) without leakage, compared to 0.18 ± 0.02 m for cathodes made using PTFE binder and PDMS diffusion layer. The cost of PVDF and activated carbon ($3 m–2) was less than that of the stainless steel mesh current collector ($12 m–2). PVDF-based AC cathodes therefore are inexpensive, have excellent performance in terms of power and water leakage, and they can be easily manufactured using a single phase inversion process at room temperature.

  16. Air quality

    International Nuclear Information System (INIS)

    1995-01-01

    This chapter of the 'Assessment of the state of the environment in Lebanon' describes the air quality and identifies the most important air quality issues. Baseline information about the factors affecting dispersion and the climate of Lebanon presents as well and overall estimation of total emissions in Lebanon. Emissions from vehicles, electricity and power plants generation are described. Industrial emitters of air pollutants are described for each kind of industry i.e.cement plants, Selaata fertilizer factory, sugar-beet factory, refineries and for those derived from the use of leaded fuel . Impact of economic and human activities on air quality in Lebanon (especially in Beirut and Tripoli) are quantified by quantities of CO 2 , SO 2 , NO x , total suspended particulates(TSP), deposition and their environmental effects on health. In abscence of emissions monitoring, data available are expressed in terms of fuel use, output and appropriate empirical factors, national output and workfores sizes. Finally key issues and some potential mitigation /management approaches are presented

  17. Air pollution

    International Nuclear Information System (INIS)

    Anon.

    2008-01-01

    Air pollution has accompanied and developed with the industrial age, since its beginnings. This very complete review furnishes the toxicological data available for the principal pollutants and assesses the epidemiologic studies thus far conducted. It also describes European regulations and international commitments for the reduction of emissions. (author)

  18. Dirty air or shelter air

    International Nuclear Information System (INIS)

    Schlesinger, H.

    1981-01-01

    The life-saving function of a shelter especially against radioactive radiation depends above all on its ventilation-air filter system. It has to function without a mistake. As the structure itself assures radiation protection only in part even when it has very thick concrete walls and a total protection equipment it does not have any effect when the ventilation-air filter system installation has some defects. Its exact calculation, installation and subsequent permanent control assure optimal protection. The problem concerning the efficiency of the technical installations in shelters and the maintenance of this function is discussed. (orig./HP) [de

  19. Royal Danish Air Force. Air Operations Doctrine

    DEFF Research Database (Denmark)

    Nørby, Søren

    This brief examines the development of the first Danish Air Force Air Operations Doctrine, which was officially commissioned in October 1997 and remained in effect until 2010. The development of a Danish air power doctrine was heavily influenced by the work of Colonel John Warden (USAF), both...... through his book ”The Air Campaign” and his subsequent planning of the air campaign against Iraq in 1990-1991. Warden’s ideas came to Denmark and the Danish Air Force by way of Danish Air Force students attending the United States Air Force Air University in Alabama, USA. Back in Denmark, graduates from...... the Air University inspired a small number of passionate airmen, who then wrote the Danish Air Operations Doctrine. The process was supported by the Air Force Tactical Command, which found that the work dovetailed perfectly with the transformation process that the Danish Air Force was in the midst...

  20. Forced Air-Breathing PEMFC Stacks

    Directory of Open Access Journals (Sweden)

    K. S. Dhathathreyan

    2012-01-01

    Full Text Available Air-breathing fuel cells have a great potential as power sources for various electronic devices. They differ from conventional fuel cells in which the cells take up oxygen from ambient air by active or passive methods. The air flow occurs through the channels due to concentration and temperature gradient between the cell and the ambient conditions. However developing a stack is very difficult as the individual cell performance may not be uniform. In order to make such a system more realistic, an open-cathode forced air-breathing stacks were developed by making appropriate channel dimensions for the air flow for uniform performance in a stack. At CFCT-ARCI (Centre for Fuel Cell Technology-ARC International we have developed forced air-breathing fuel cell stacks with varying capacity ranging from 50 watts to 1500 watts. The performance of the stack was analysed based on the air flow, humidity, stability, and so forth, The major advantage of the system is the reduced number of bipolar plates and thereby reduction in volume and weight. However, the thermal management is a challenge due to the non-availability of sufficient air flow to remove the heat from the system during continuous operation. These results will be discussed in this paper.

  1. Bi-Cell Unit for Fuel Cell.

    Science.gov (United States)

    The patent concerns a bi-cell unit for a fuel cell . The bi-cell unit is comprised of two electrode packs. Each of the electrode packs includes an...invention relates in general to a bi-cell unit for a fuel cell and in particular, to a bi-cell unit for a hydrazine-air fuel cell .

  2. Air Warfare

    Science.gov (United States)

    2002-03-01

    genus as its predecessor of pre-war days. It would, however, be erroneous to conclude from this that the military value of each new development was...marked by periods of crescendo, air warfare will consist of a succession of actions of great violence , with periods of almost complete calm between...influence of time, if it should require fif- teen seconds for each airplane to take off, and one minute to land, the commander of a group of 100 airplanes

  3. Air filtration and indoor air quality

    DEFF Research Database (Denmark)

    Bekö, Gabriel

    2006-01-01

    Demands for better indoor air quality are increasing, since we spend most of our time indoors and we are more and more aware of indoor air pollution. Field studies in different parts of the world have documented that high percentage of occupants in many offices and buildings find the indoor air...... decent ventilation and air cleaning/air filtration, high indoor air quality cannot be accomplished. The need for effective air filtration has increased with increasing evidence on the hazardous effects of fine particles. Moreover, the air contains gaseous pollutants, removal of which requires various air...... cleaning techniques. Supply air filter is one of the key components in the ventilation system. Studies have shown that used ventilation filters themselves can be a significant source of indoor air pollution with consequent impact on perceived air quality, sick building syndrome symptoms and performance...

  4. Atomic Layer Deposition of TiO2 for a High-Efficiency Hole-Blocking Layer in Hole-Conductor-Free Perovskite Solar Cells Processed in Ambient Air.

    Science.gov (United States)

    Hu, Hang; Dong, Binghai; Hu, Huating; Chen, Fengxiang; Kong, Mengqin; Zhang, Qiuping; Luo, Tianyue; Zhao, Li; Guo, Zhiguang; Li, Jing; Xu, Zuxun; Wang, Shimin; Eder, Dominik; Wan, Li

    2016-07-20

    In this study we design and construct high-efficiency, low-cost, highly stable, hole-conductor-free, solid-state perovskite solar cells, with TiO2 as the electron transport layer (ETL) and carbon as the hole collection layer, in ambient air. First, uniform, pinhole-free TiO2 films of various thicknesses were deposited on fluorine-doped tin oxide (FTO) electrodes by atomic layer deposition (ALD) technology. Based on these TiO2 films, a series of hole-conductor-free perovskite solar cells (PSCs) with carbon as the counter electrode were fabricated in ambient air, and the effect of thickness of TiO2 compact film on the device performance was investigated in detail. It was found that the performance of PSCs depends on the thickness of the compact layer due to the difference in surface roughness, transmittance, charge transport resistance, electron-hole recombination rate, and the charge lifetime. The best-performance devices based on optimized TiO2 compact film (by 2000 cycles ALD) can achieve power conversion efficiencies (PCEs) of as high as 7.82%. Furthermore, they can maintain over 96% of their initial PCE after 651 h (about 1 month) storage in ambient air, thus exhibiting excellent long-term stability.

  5. California Air Basins

    Data.gov (United States)

    California Department of Resources — Air ResourcesCalifornia Air Resources BoardThe following datasets are from the California Air Resources Board: * arb_california_airbasins - California Air BasinsThe...

  6. AirData

    Data.gov (United States)

    U.S. Environmental Protection Agency — The AirData site provides access to yearly summaries of United States air pollution data, taken from EPA's air pollution databases. AirData has information about...

  7. Air Quality System (AQS)

    Science.gov (United States)

    The Air Quality System (AQS) database contains measurements of air pollutant concentrations from throughout the United States and its territories. The measurements include both criteria air pollutants and hazardous air pollutants.

  8. Hazardous Air Pollutants

    Science.gov (United States)

    ... Protection Agency Search Search Contact Us Share Hazardous Air Pollutants Hazardous air pollutants are those known to ... of industrial facilities in two phases . About Hazardous Air Pollutants What are Hazardous Air Pollutants? Health and ...

  9. Aeromicrobiology/air quality

    Science.gov (United States)

    Andersen, Gary L.; Frisch, A.S.; Kellogg, Christina A.; Levetin, E.; Lighthart, Bruce; Paterno, D.

    2009-01-01

    The most prevalent microorganisms, viruses, bacteria, and fungi, are introduced into the atmosphere from many anthropogenic sources such as agricultural, industrial and urban activities, termed microbial air pollution (MAP), and natural sources. These include soil, vegetation, and ocean surfaces that have been disturbed by atmospheric turbulence. The airborne concentrations range from nil to great numbers and change as functions of time of day, season, location, and upwind sources. While airborne, they may settle out immediately or be transported great distances. Further, most viable airborne cells can be rendered nonviable due to temperature effects, dehydration or rehydration, UV radiation, and/or air pollution effects. Mathematical microbial survival models that simulate these effects have been developed.

  10. Effects of Cd{sub 1-x}Zn{sub x}S alloy composition and post-deposition air anneal on ultra-thin CdTe solar cells produced by MOCVD

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, A.J., E-mail: Andrew.J.Clayton@Swansea.ac.uk [Centre for Solar Energy Research, College of Engineering, Swansea University, OpTIC, St. Asaph, LL17 0JD (United Kingdom); Baker, M.A.; Babar, S.; Grilli, R. [The Surface Analysis Laboratory, Department of Mechanical Engineering Sciences, University of Surrey, Guildford, GU2 7XH (United Kingdom); Gibson, P.N. [Institute for Health and Consumer Protection, Joint Research Centre of the European Commission, 21027, Ispra, VA (Italy); Kartopu, G.; Lamb, D.A. [Centre for Solar Energy Research, College of Engineering, Swansea University, OpTIC, St. Asaph, LL17 0JD (United Kingdom); Barrioz, V. [Engineering and Environment, Department of Physics and Electrical Engineering, Northumbria University, Newcastle, NE1 8ST (United Kingdom); Irvine, S.J.C. [Centre for Solar Energy Research, College of Engineering, Swansea University, OpTIC, St. Asaph, LL17 0JD (United Kingdom)

    2017-05-01

    Ultra-thin CdTe:As/Cd{sub 1-x}Zn{sub x}S photovoltaic solar cells with an absorber thickness of 0.5 μm were deposited by metal-organic chemical vapour deposition on indium tin oxide coated boro-aluminosilicate substrates. The Zn precursor concentration was varied to compensate for Zn leaching effects after CdCl{sub 2} activation treatment. Analysis of the solar cell composition and structure by X-ray photoelectron spectroscopy depth profiling and X-ray diffraction showed that higher concentrations of Zn in the Cd{sub 1-x}Zn{sub x}S window layer resulted in suppression of S diffusion across the CdTe/Cd{sub 1-x}Zn{sub x}S interface after CdCl{sub 2} activation treatment. Excessive Zn content in the Cd{sub 1-x}Zn{sub x}S alloy preserved the spectral response in the blue region of the solar spectrum, but increased series resistance for the solar cells. A modest increase in the Zn content of the Cd{sub 1-x}Zn{sub x}S alloy together with a post-deposition air anneal resulted in an improved blue response and an enhanced open circuit voltage and fill factor. This device yielded a mean efficiency of 8.3% over 8 cells (0.25 cm{sup 2} cell area) and best cell efficiency of 8.8%. - Highlights: • CdCl{sub 2} anneal treatment resulted in S diffusing to the back contact. • High Zn levels created mixed cubic/hexagonal structure at the p-n junction. • Increased Zn in Cd{sub 1-x}Zn{sub x}S supressed S diffusion into CdTe. • Device V{sub oc} was enhanced overall with an additional back surface air anneal.

  11. Toxicological Impact of Air Pollution Particulate Matter PM 2.5 Collected under Urban Industrial or Rural Influence Occurrence of Oxidative Stress and Inflammatory Reaction in BEAS 2B Human Bronchial Epithelial Cells Corrected Version

    International Nuclear Information System (INIS)

    Dergham, M.; Billet, S; Verdin, A.; Courcot, D.; Cazier, F.; Pirouz, Sh.; Garcon, G.

    2011-01-01

    Exposure to air pollution Particulate Matter (PM) is one of the risk factors involved in the high incidence of respiratory and cardio-vascular diseases. In this work, to integrate inter-seasonal and inter-site variations, fine particle (PM2.5) samples have been collected in spring-summer 2008) and autumn 2008-winter 2009, in Dunkerque (France) under urban or industrial influence, and in Rubrouck (France), under rural influence. Attention was paid to characterize their physico-chemical characteristics, and to determine their ability to induce oxidative stress and inflammatory response in a human bronchial epithelial cell model (BEAS-2B cell line). Physico-chemical characterization of the six PM samples showed their heterogeneities and complexities depending upon their respective natural and/or anthropogenic emission sources. Lung cytotoxicity of these air pollution PM2.5 samples, as shown in BEAS-2B cells, might rely on the induction of oxidative stress conditions and particularly on the excessive inflammatory response. (author)

  12. Ex vivo exposure to gaseous pollutants of air passages and human and animal pulmonary vessels: effect on the reactivity and cell signalling; Exposition ex vivo aux polluants gazeux des voies aeriennes et de vaisseaux pulmonaires humains et animaux: effet sur la reactivite et la signalisation cellulaire

    Energy Technology Data Exchange (ETDEWEB)

    Hyvelin, J.M.

    2000-07-01

    The objectives of this work have been to characterize effects of exposure to several pollutants on the reactivity of air passages, to study the action mechanisms of pollutants on the smooth muscle cell of air passages, to characterize the calcic signalling of the human bronchi smooth muscle in order to identify the pollutants cell targets, to look for others pollutants cell targets. This work contributes to a better knowledge of air pollution effects, by underlining the additive character of pollutants. It allows a better knowledge of cell mechanisms implied in the pollutants effects. Then, it notices the existence of other cell types, the pulmonary arterial myocyte, sensitive to pollutants exposure and that can be implied in the respiratory health degradation. (N.C.)

  13. Development of measure methods of radon in indoor air

    International Nuclear Information System (INIS)

    Yaginuma, L.T.; Pela, C.A.; Navas, E.A.; Ghilardi, A.J.P.

    1992-01-01

    The development of some conventional measuring methods, aiming obtain an estimation of radon concentration in air, mainly in indoor air is described, including the charcoal absorption collector, Lucas cell and thermoluminescent dosemeters. (C.G.C)

  14. Switching on the Aire conditioner.

    Science.gov (United States)

    Matsumoto, Mitsuru

    2015-12-01

    Aire has been cloned as the gene responsible for a hereditary type of organ-specific autoimmune disease. Aire controls the expression of a wide array of tissue-restricted Ags by medullary thymic epithelial cells (mTECs), thereby leading to clonal deletion and Treg-cell production, and ultimately to the establishment of self-tolerance. However, relatively little is known about the mechanism responsible for the control of Aire expression itself. In this issue of the European Journal of Immunology, Haljasorg et al. [Eur. J. Immunol. 2015. 45: 3246-3256] have reported the presence of an enhancer element for Aire that binds with NF-κB components downstream of the TNF receptor family member, RANK (receptor activator of NF-κB). The results suggest that RANK has a dual mode of action in Aire expression: one involving the promotion of mTEC differentiation and the other involving activation of the molecular switch for Aire within mature mTECs. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Air movement and perceived air quality

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor; Kaczmarczyk, J.

    2012-01-01

    The impact of air movement on perceived air quality (PAQ) and sick building syndrome (SBS) symptoms was studied. In total, 124 human subjects participated in four series of experiments performed in climate chambers at different combinations of room air temperature (20, 23, 26 and 28 °C), relative....... min. Acceptability of PAQ and freshness of the air improved when air movement was applied. The elevated air movement diminished the negative impact of increased air temperature, relative humidity and pollution level on PAQ. The degree of improvement depended on the pollution level, the temperature...

  16. Novel design of a compacted micro-structured air-breathing PEM fuel cell as a power source for mobile phones

    OpenAIRE

    Maher A.R. Sadiq Al-Baghdadi

    2010-01-01

    The presence of microelectromechanical system (MEMS) technology makes it possible to manufacture the miniaturized fuel cell systems for application in portable electronic devices. The majority of research on micro-scale fuel cells is aimed at micro-power applications. There are many new miniaturized applications which can only be realized if a higher energy density power source is available compared to button cells and other small batteries. In small-scale applications, the fuel cell should b...

  17. Cellular effects in an in vitro human 3D cellular airway model and A549/BEAS-2B in vitro cell cuultures following air exposure to cerium oxide particles at an air-liquid interface

    NARCIS (Netherlands)

    Kooter, I.M.; Grollers-Mulderij, M.; Steenhof, M.; Duistermaat, E.; Acker, F.A.A. van; Staal, Y.C.M.; Tromp, P.C.; Schoen, E.D.; Kuiper, C.F.; Someren, E.P. van

    2016-01-01

    There is a need for representative in vitro models to assess the effects of airborne particles on lung health. The ob-jective of this study was to assess the cellular effects of cerium oxide (Ce02) particles exposed via an air—liquid interface in three relevant cell models in parallel. BEAS-2B,

  18. AIRE in the thymus and beyond.

    Science.gov (United States)

    Gardner, James M; Fletcher, Anne L; Anderson, Mark S; Turley, Shannon J

    2009-12-01

    The maintenance of immunologic self-tolerance requires the coordination of multiple complementary systems. Studies of the Autoimmune Regulator (Aire) gene have revealed that Aire promotes self-tolerance partly by inducing the transcription of a wide array of tissue-specific antigens (TSAs), particularly in the thymus. The importance of Aire is highlighted by the fact that patients and mice defective in Aire expression develop a multi-organ autoimmune syndrome. In this review we discuss recent progress in our understanding of Aire's control of immune tolerance at the cellular and molecular levels, and also address the potential importance of Aire expression both in the thymus and in the peripheral lymphoid organs. The detection of both Aire and TSA expression by cell populations outside of the thymus raises the possibility that such expression may play a relevant role in the maintenance of self-tolerance.

  19. The role of Aire in clonal selection.

    Science.gov (United States)

    Taniguchi, Ruth T; Anderson, Mark S

    2011-01-01

    In his clonal selection theory, Frank Macfarlane Burnet predicted that autoreactive lymphocytes are deleted to prevent autoimmunity. This and other principles of lymphocyte behavior outlined by Burnet guided many studies that lead to our current understanding of thymic selection. Thus, when the genetic mutation responsible for autoimmune polyglandular syndrome type 1 was mapped to the autoimmune regulator (AIRE) gene, and Aire was found to be highly expressed in thymic epithelium, studying the role of Aire in negative selection made sense in the context of modern models of thymic selection. We now know Aire is a transcription factor required for the expression of many tissue-specific antigens (TSAs) in the thymus. In the absence of functional Aire, human patients and mice develop multi-organ autoimmune disease because of a defect in thymic negative selection. In addition to its role in the thymus, recent work in our lab suggests that extrathymic Aire-expressing cells have an important role in the clonal deletion of autoreactive CD8+ T cells. In this review, we summarize the latest studies on thymic and peripheral Aire-expressing cells, as well as other TSA-expressing stromal cell populations in peripheral lymphoid organs. We also discuss theoretical differences in thymic and peripheral Aire function that warrant further studies.

  20. Design and Control of High Temperature PEM Fuel Cell Systems using Methanol Reformers with Air or Liquid Heat Integration:Proceedings CD

    OpenAIRE

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Sahlin, Simon Lennart; Justesen, Kristian Kjær

    2013-01-01

    The present work describes the ongoing development of high temperature PEM fuel cell systems fuelled by steam reformed methanol. Various fuel cell system solutions exist, they mainly differ depending on the desired fuel used. Hightemperature PEM (HTPEM) fuel cells offer the possibility of using liquid fuels such as methanol, due to the increased robustness of operating at higher temperatures (160-180oC). Using liquid fuels such as methanol removes the high volume demands of compressed hydroge...

  1. Air pollution particles and iron homeostasis

    Science.gov (United States)

    Background: The mechanism underlying biological effects of particles deposited in the lung has not been defined. Major Conclusions: A disruption in iron homeostasis follows exposure of cells to all particulate matter including air pollution particles. Following endocytosis, fun...

  2. Hi-g lithium thionyl chloride flat cells for artillery/air delivered expendables. Quarterly report no. 1, 10 October 31-December 1980

    Energy Technology Data Exchange (ETDEWEB)

    Snuggerud, D.; Surprenant, J.; Waterhouse, R.

    1981-05-01

    Rate capability studies on small prototype cells showed that single anode designs should be adequate for Hi-G rate specifications. Large prototype cells safely delivered 1.6 amps for 6 hours. Design work was begun on seal structures to withstand extreme g forces.

  3. Cathode Composition in a Saltwater Metal-Air Battery

    Directory of Open Access Journals (Sweden)

    William Shen

    2017-01-01

    Full Text Available Metal-air batteries consist of a solid metal anode and an oxygen cathode of ambient air, typically separated by an aqueous electrolyte. Here, simple saltwater-based models of aluminum-air and zinc-air cells are used to determine the differences between theoretical cell electric potentials and experimental electric potentials. A substantial difference is observed. It is also found that the metal cathode material is crucial to cell electric potential, despite the cathode not participating in the net reaction. Finally, the material composition of the cathode appears to have a more significant impact on cell potential than the submerged surface area of the cathode.

  4. Measurement of Atmospheric Pressure Air Plasma via Pulsed Electron Beam and Sustaining Electric Field

    National Research Council Canada - National Science Library

    Vidmar, Robert J; Stalder, Kenneth R

    2007-01-01

    .... A particle in cell plasma code (MAGIC) and an air-chemistry code are used to quantify beam propagation through an electron-beam transmission window into air and the volumetric ionization rate within the test cell...

  5. Study on the performance of Nafion 212 membrane in polymeric electrolyte fuel cells operating with air; Estudo do desempenho da membrana de Nafion 212 em celulas a combustivel de eletrolito polimerico operando com ar

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Adriano C.; Ticianelli, Edson Antonio [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Inst. de Quimica]. E-mail: edsont@iqsc.usp.br

    2008-07-01

    The operational characteristics of the Nafion 212 membrane (N212) were investigated and compared to the Nafion 112 membrane (N112), both 50 thick, in polymer electrolyte fuel cell (PEFC). The polarization measurements were performed changing the cell and gases humidification temperature and the gases pressure. The kinetic parameters obtained from the polarization curve proved that the cell with membrane N212 showed better performance than membrane N112, when they operating with air at cathode. The electrochemical impedance studies were carried out to make clear the polarization phenomena due to the resistive and diffusive effects that limit the cell performance. At high frequency region is found an arc, which dimension in depends on the current density, whereas at the mid frequency region we can find two loops with different characteristics and both dependent of current density. This behavior becomes evident that there are polarization components linked to resistive processes at high frequency, as well as charge transference and diffusional at mid and low frequency, respectively. (author)

  6. Clean Air Markets

    Science.gov (United States)

    Clean Air Markets implements regulatory programs such as the Acid Rain Program and the Cross-State Air Pollution Rule to reduce air pollution from the power sector that contributes to human health and environmental issues.

  7. Indoor Air Quality

    Science.gov (United States)

    ... protect yourself and your family. Learn more Air Quality at Work Workers should breathe easy while on the job, but worksites with poor air quality put employees at risk. Healthy air is essential ...

  8. GSPEL - Air Filtration Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Evaluation capabilities for air filtration devicesThe Air Filtration Lab provides testing of air filtration devices to demonstrate and validate new or legacy system...

  9. Outdoor air Pollution

    CSIR Research Space (South Africa)

    Forbes, PBC

    2016-07-01

    Full Text Available regions. Ambient air pollution relates to the quality of outdoor air and will be discussed in this chapter, with a focus on the air pollutants which are typically regulated in this context internationally....

  10. Wisconsin Air Cargo Study

    Science.gov (United States)

    2011-04-01

    Air cargo is a key economic lifeline for the communities that have airports. Manufacturers, businesses, hospitals and : other community cornerstone employers depend on air cargo to successfully operate. While there is no doubt that air : cargo repres...

  11. Air Sensor Toolbox

    Science.gov (United States)

    Air Sensor Toolbox provides information to citizen scientists, researchers and developers interested in learning more about new lower-cost compact air sensor technologies and tools for measuring air quality.

  12. HEPA air filter (image)

    Science.gov (United States)

    ... pet dander and other irritating allergens from the air. Along with other methods to reduce allergens, such ... controlling the amount of allergens circulating in the air. HEPA filters can be found in most air ...

  13. Kinetics of ROS generation induced by polycyclic aromatic hydrocarbons and organic extracts from ambient air particulate matter in model human lung cell lines.

    Science.gov (United States)

    Libalova, Helena; Milcova, Alena; Cervena, Tereza; Vrbova, Kristyna; Rossnerova, Andrea; Novakova, Zuzana; Topinka, Jan; Rossner, Pavel

    2018-03-01

    Polycyclic aromatic hydrocarbons (PAHs) associated with particulate matter (PM) may induce oxidative damage via reactive oxygen species (ROS) generation. However, the kinetics of ROS production and the link with antioxidant response induction has not been well studied. To elucidate the differences in oxidative potential of individual PAH compounds and extractable organic matter (EOM) from PM containing various PAH mixtures, we studied ROS formation and antioxidant response [total antioxidant capacity (TAC) and expression of HMOX1 and TXNRD1] in human alveolar basal epithelial cells (A549 cells) and human embryonic lung fibroblasts (HEL12469 cells). We treated the cells with three concentrations of model PAHs (benzo[a]pyrene, B[a]P; 3-nitrobenzanthrone, 3-NBA) and EOM from PM ROS levels were evaluated at 8 time intervals (30 min-24 h). In both cell lines, B[a]P treatment was associated with a time-dependent decrease of ROS levels. This trend was more pronounced in HEL12469 cells and was accompanied by increased TAC. A similar response was observed upon 3-NBA treatment in HEL12469 cells. In A549 cells, however, this compound significantly increased superoxide levels. This response was accompanied by the decrease of TAC as well as HMOX1 and TXNRD1 expression. In both cell lines, a short-time exposure to EOMs tended to increase ROS levels, while a marked decrease was observed after longer treatment periods. This was accompanied by the induction of HMOX1 and TXNRD1 expression in HEL12469 cells and increased TAC in A549 cells. In summary, our data indicate that in the studied cell lines B[a]P and EOMs caused a time-dependent decrease of intracellular ROS levels, probably due to the activation of the antioxidant response. This response was not detected in A549 cells following 3-NBA treatment, which acted as a strong superoxide inducer. Pro-oxidant properties of EOMs are limited to short-time exposure periods. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Primary zone air proportioner

    Science.gov (United States)

    Cleary, Edward N. G.

    1982-10-12

    An air proportioner is provided for a liquid hydrocarbon fueled gas turbine of the type which is convertible to oil gas fuel and to coal gas fuel. The turbine includes a shell for enclosing the turbine, an air duct for venting air in said shell to a gasifier, and a fuel injector for injecting gasified fuel into the turbine. The air proportioner comprises a second air duct for venting air from the air duct for mixing with fuel from the gasifier. The air can be directly injected into the gas combustion basket along with the fuel from the injector or premixed with fuel from the gasifier prior to injection by the fuel injector.

  15. 40 CFR 90.310 - Engine intake air humidity measurement.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine intake air humidity measurement... Emission Test Equipment Provisions § 90.310 Engine intake air humidity measurement. This section refers to... for the engine intake air, the ambient test cell humidity measurement may be used. (a) Humidity...

  16. Kajian Analitik Perencanaan Pintu Air Pembangkit Listrik Tenaga Air

    OpenAIRE

    Pradoto, Pradoto

    1993-01-01

    Pada pintu air pembangkit listrik tenaga air umumnya dipasang pengauat-penguat (girder). Tujuannya agar pintu air kuat dalam menahan tekanan air. Tekanan air yang diderita oleh pintu air cukup besar karena dipasang pada kedalaman + 50 meter di bawah permukaan air. Permasalahan yang timbul adalah menentukan posisi atau letak girder pada pintu air.

  17. Genotoxic and mutagenic effects of passive smoking and urban air pollutants in buccal mucosa cells of children enrolled in public school.

    Science.gov (United States)

    Cavalcante, Deborah Navit de Carvalho; Sposito, Juliana Caroline Vivian; Crispim, Bruno do Amaral; Nascimento, André Vieira do; Grisolia, Alexeia Barufatti

    2017-06-01

    Nuclear abnormalities (micronuclei and meta-nuclear changes) have been used as biomarkers to identify cell damages. As children are more vulnerable to the adverse effects of pollution when compared to adults, assessing genetic damage caused by environmental influences is of great interest. As such, the objective was to determine metanuclear (karyolysis, pycnosis, karyorrhexis, binucleated cells, chromosome bridges and micronuclei) in cells from the oral mucosa of children associated with the school environment, gender, exposure to cigarette smoke and vehicular traffic. Analyses of nuclear abnormalities were performed in exfoliated buccal cells of children from two public schools located in Dourados - MS. The data were analyzed through Kruskal-Wallis test considering a significance level of 5% (p mutagenic and genotoxic agent, suggesting that such contaminants are related to clastogenic and aneugenic effects on DNA. Moreover, female children had higher amounts of nuclear abnormalities when compared to male children. With regards to the school environment, the study results indicated statistical differences in of term chromosomal abnormalities for schools A and B. Thus, it was possible to determine that children exposed to cigarette smoke are susceptible to further genetic damage than unexposed children, and female children may be more susceptible to genotoxic and mutagenic agents. This study contributes to the current knowledge on the mutagenic characteristics of human cells, supporting the adoption of preventive Public Health measures.

  18. Hazardous air pollutants

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This chapter presents an overview of the requirements of Title 3 of the 1990 Amendments to the Clean Air Act. The following topics are included: listed air toxics; sources covered by the program; standards for regulation of air toxics; area source program; air toxics permit program; prevention of accidental releases; and duties of the Risk Assessment and Management Commission

  19. Ectopic Aire Expression in the Thymic Cortex Reveals Inherent Properties of Aire as a Tolerogenic Factor within the Medulla.

    Science.gov (United States)

    Nishijima, Hitoshi; Kitano, Satsuki; Miyachi, Hitoshi; Morimoto, Junko; Kawano, Hiroshi; Hirota, Fumiko; Morita, Ryoko; Mouri, Yasuhiro; Masuda, Kiyoshi; Imoto, Issei; Ikuta, Koichi; Matsumoto, Mitsuru

    2015-11-15

    Cortical thymic epithelial cells (cTECs) and medullary thymic epithelial cells (mTECs) play essential roles in the positive and negative selection of developing thymocytes, respectively. Aire in mTECs plays an essential role in the latter process through expression of broad arrays of tissue-restricted Ags. To determine whether the location of Aire within the medulla is absolutely essential or whether Aire could also function within the cortex for establishment of self-tolerance, we used bacterial artificial chromosome technology to establish a semiknockin strain of NOD-background (β5t/Aire-transgenic) mice expressing Aire under control of the promoter of β5t, a thymoproteasome expressed exclusively in the cortex. Although Aire was expressed in cTECs as typical nuclear dot protein in β5t/Aire-Tg mice, cTECs expressing Aire ectopically did not confer transcriptional expression of either Aire-dependent or Aire-independent tissue-restricted Ag genes. We then crossed β5t/Aire-Tg mice with Aire-deficient NOD mice, generating a strain in which Aire expression was confined to cTECs. Despite the presence of Aire(+) cTECs, these mice succumbed to autoimmunity, as did Aire-deficient NOD mice. The thymic microenvironment harboring Aire(+) cTECs, within which many Aire-activated genes were present, also showed no obvious alteration of positive selection, suggesting that Aire's unique property of generating a self-tolerant T cell repertoire is functional only in mTECs. Copyright © 2015 by The American Association of Immunologists, Inc.

  20. AIRE and APECED: molecular insights into an autoimmune disease.

    Science.gov (United States)

    Villaseñor, Jennifer; Benoist, Christophe; Mathis, Diane

    2005-04-01

    Mutations in the autoimmune regulator (AIRE) protein are the causative factor in development of the human disease autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). In mice, the absence of the analogous protein aire influences ectopic expression of peripheral tissue antigens in thymic medullary epithelial cells (MECs), resulting in the development of an autoimmune disorder similar to APECED and establishing aire/AIRE as an important player in the induction of central tolerance. However, the molecular mechanism of AIRE's function, in particular its ability to specifically control the expression of peripheral tissue antigens in MECs, is still unclear. Here, we review current evidence relating to the molecular mechanism of AIRE.

  1. Reactive Air Aluminization

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jung-Pyung; Chou, Y. S.; Stevenson, Jeffry W.

    2011-10-28

    Ferritic stainless steels and other alloys are of great interest to SOFC developers for applications such as interconnects, cell frames, and balance of plant components. While these alloys offer significant advantages (e.g., low material and manufacturing cost, high thermal conductivity, and high temperature oxidation resistance), there are challenges which can hinder their utilization in SOFC systems; these challenges include Cr volatility and reactivity with glass seals. To overcome these challenges, protective coatings and surface treatments for the alloys are under development. In particular, aluminization of alloy surfaces offers the potential for mitigating both evaporation of Cr from the alloy surface and reaction of alloy constituents with glass seals. Commercial aluminization processes are available to SOFC developers, but they tend to be costly due to their use of exotic raw materials and/or processing conditions. As an alternative, PNNL has developed Reactive Air Aluminization (RAA), which offers a low-cost, simpler alternative to conventional aluminization methods.

  2. Monitoring Distribusi Air Bersih

    OpenAIRE

    Sutono Sutono

    2016-01-01

    Abstrak - Penelitian ini bertujuan untuk memberikan pilihan solusi permasalahan penyaluran air pada Wilayah Babakan Irigasi yang memiliki masalah terbatasnya Kuota Air Bersih untuk memenuhi kebutuhan penggunaan air sehari-hari. Pemanfaatan Mikrokontroler Arduino Atmega328 pada Arduino UNO yang dirancang dengan menambahkan beberapa komponen pendukung seperti Sensor Flowmeter, Selenoid Valve dan Pompa Air dibuat menjadi sistem kran air otomatis. Sistem ini bekerja dengan dikontrol oleh timer da...

  3. Alveolar epithelial cells (A549) exposed at the air-liquid interface to diesel exhaust: First study in TNO's powertrain test center

    NARCIS (Netherlands)

    Kooter, I.M.; Alblas, M.J.; Jedynska, A.D.; Steenhof, M.; Houtzager, M.M.G.; Ras, M.G. van

    2013-01-01

    Air–liquid interface (ALI) exposures enable in vitro testing ofmixtures of gases and particles such as diesel exhaust (DE). The main objective of this study was to investigate the feasibility of exposing human lung epithelial cells at the ALI to complete DE generated by a heavy-duty truck in the

  4. Aqua AIRS Level 3 Pentad Quantization in Physical Units (AIRS+AMSU) V006

    Data.gov (United States)

    National Aeronautics and Space Administration — AIRS/Aqua Level 3 pentad quantization product in physical units (Without HSB). The geophysical parameters have been averaged and binned into 1 x 1 deg grid cells,...

  5. AIRS/Aqua Level 3 Pentad quantization in physical units (AIRS+AMSU) V005

    Data.gov (United States)

    National Aeronautics and Space Administration — AIRS/Aqua Level 3 pentad quantization product in physical units (Without HSB). The geophysical parameters have been averaged and binned into 1 x 1 deg grid cells,...

  6. A Lithium-Air Battery with a High Energy Air Cathode, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This project will advance an efficient and lightweight energy storage device for Oxygen Concentrators by developing a high specific energy lithium-air cell....

  7. Prooxidant and proinflammatory potency of air pollution particulate matter (PM₂.₅₋₀.₃) produced in rural, urban, or industrial surroundings in human bronchial epithelial cells (BEAS-2B).

    Science.gov (United States)

    Dergham, Mona; Lepers, Capucine; Verdin, Anthony; Billet, Sylvain; Cazier, Fabrice; Courcot, Dominique; Shirali, Pirouz; Garçon, Guillaume

    2012-04-16

    Compelling evidence indicates that exposure to air pollution particulate matter (PM) affects human health. However, how PM composition interacts with PM-size to cause adverse health effects needs elucidation. In this study, we were also interested in the physicochemical characteristics and toxicological end points of PM₂.₅₋₀.₃ samples produced in rural, urban, or industrial surroundings, thereby expecting to differentiate their respective in vitro adverse health effects in human bronchial epithelial cells (BEAS-2B). Physicochemical characteristics of the three PM₂.₅₋₀.₃ samples, notably their inorganic and organic components, were closely related to their respective emission sources. Referring also to the dose/response relationships of the three PM₂.₅₋₀.₃ samples, the most toxicologically relevant exposure times (i.e., 24, 48, and 72 h) and doses (i.e., 3.75 μg PM/cm² and 15 μg PM/cm²) to use to study the underlying mechanisms of action involved in PM-induced lung toxicity were chosen. Organic chemicals adsorbed on the three PM₂.₅₋₀.₃ samples (i.e., polycyclic aromatic hydrocarbons) were able to induce the gene expression of xenobiotic-metabolizing enzymes (i.e., Cytochrome P4501A1 and 1B1, and, to a lesser extent, NADPH-quinone oxidoreductase-1). Moreover, intracellular reactive oxygen species within BEAS-2B cells exposed to the three PM₂.₅₋₀.₃ samples induced oxidative damage (i.e., 8-hydroxy-2'-deoxyguanosine formation, malondialdehyde production and/or glutathione status alteration). There were also statistically significant increases of the gene expression and/or protein secretion of inflammatory mediators (i.e., notably IL-6 and IL-8) in BEAS-2B cells after their exposure to the three PM₂.₅₋₀.₃ samples. Taken together, the present findings indicated that oxidative damage and inflammatory response preceeded cytotoxicity in air pollution PM₂.₅₋₀.₃-exposed BEAS-2B cells and supported the

  8. A new cell line-based coculture model of the human air-blood barrier to evaluate the interaction with aerosolized drug carriers

    OpenAIRE

    Kletting, Stephanie

    2016-01-01

    Besides reducing animal testing, in vitro models allow for the pre-screening of new drug candidates in terms of safety and efficacy before they enter clinical trials. To date, models mimicking the deep lung show limitations such as cellular origin or lack of appropriate barrier properties. Therefore, the focus of this work was on the establishment of a robust and reproducible cell line-based coculture model that reflects the two major barrier structures present in the alveolar region, namely ...

  9. High-efficiency and air-stable P3HT-based polymer solar cells with a new non-fullerene acceptor

    Science.gov (United States)

    Holliday, Sarah; Ashraf, Raja Shahid; Wadsworth, Andrew; Baran, Derya; Yousaf, Syeda Amber; Nielsen, Christian B.; Tan, Ching-Hong; Dimitrov, Stoichko D.; Shang, Zhengrong; Gasparini, Nicola; Alamoudi, Maha; Laquai, Frédéric; Brabec, Christoph J.; Salleo, Alberto; Durrant, James R.; McCulloch, Iain

    2016-01-01

    Solution-processed organic photovoltaics (OPV) offer the attractive prospect of low-cost, light-weight and environmentally benign solar energy production. The highest efficiency OPV at present use low-bandgap donor polymers, many of which suffer from problems with stability and synthetic scalability. They also rely on fullerene-based acceptors, which themselves have issues with cost, stability and limited spectral absorption. Here we present a new non-fullerene acceptor that has been specifically designed to give improved performance alongside the wide bandgap donor poly(3-hexylthiophene), a polymer with significantly better prospects for commercial OPV due to its relative scalability and stability. Thanks to the well-matched optoelectronic and morphological properties of these materials, efficiencies of 6.4% are achieved which is the highest reported for fullerene-free P3HT devices. In addition, dramatically improved air stability is demonstrated relative to other high-efficiency OPV, showing the excellent potential of this new material combination for future technological applications. PMID:27279376

  10. High-efficiency and air-stable P3HT-based polymer solar cells with a new non-fullerene acceptor

    KAUST Repository

    Holliday, Sarah

    2016-06-09

    Solution-processed organic photovoltaics (OPV) offer the attractive prospect of low-cost, light-weight and environmentally benign solar energy production. The highest efficiency OPV at present use low-bandgap donor polymers, many of which suffer from problems with stability and synthetic scalability. They also rely on fullerene-based acceptors, which themselves have issues with cost, stability and limited spectral absorption. Here we present a new non-fullerene acceptor that has been specifically designed to give improved performance alongside the wide bandgap donor poly(3-hexylthiophene), a polymer with significantly better prospects for commercial OPV due to its relative scalability and stability. Thanks to the well-matched optoelectronic and morphological properties of these materials, efficiencies of 6.4% are achieved which is the highest reported for fullerene-free P3HT devices. In addition, dramatically improved air stability is demonstrated relative to other high-efficiency OPV, showing the excellent potential of this new material combination for future technological applications.

  11. Regulation of human autoimmune regulator (AIRE) gene translation by miR-220b.

    Science.gov (United States)

    Matsuo, Tomohito; Noguchi, Yukiko; Shindo, Mieko; Morita, Yoshifumi; Oda, Yoshie; Yoshida, Eiko; Hamada, Hiroko; Harada, Mine; Shiokawa, Yuichi; Nishida, Takahiro; Tominaga, Ryuji; Kikushige, Yoshikane; Akashi, Koichi; Kudoh, Jun; Shimizu, Nobuyoshi; Tanaka, Yuka; Umemura, Tsukuru; Taniguchi, Taketoshi; Yoshimura, Akihiko; Kobayashi, Takashi; Mitsuyama, Masao; Kurisaki, Hironori; Katsuta, Hitoshi; Nagafuchi, Seiho

    2013-11-01

    Although mutations of autoimmune regulator (AIRE) gene are responsible for autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), presenting a wide spectrum of many characteristic and non-characteristic clinical features, some patients lack AIRE gene mutations. Therefore, something other than a mutation, such as dysregulation of AIRE gene, may be a causal factor for APECED or its related diseases. However, regulatory mechanisms for AIRE gene expression and/or translation have still remained elusive. We found that IL-2-stimulated CD4(+) T (IL-2T) cells showed a high expression of AIRE gene, but very low AIRE protein production, while Epstein-Barr virus-transformed B (EBV-B) cells express both AIRE gene and AIRE protein. By using microarray analysis, we could identify miR-220b as a possible regulatory mechanism for AIRE gene translation in IL-2T cells. Here we report that miR-220b significantly reduced the expression of AIRE protein in AIRE gene with 3'UTR region transfected 293T cells, whereas no alteration of AIRE protein production was observed in the open reading frame of AIRE gene alone transfected cells. In addition, anti-miR-220b reversed the inhibitory function of miR-220b for the expression of AIRE protein in AIRE gene with 3'UTR region transfected cells. Moreover, when AIRE gene transfected cells with mutated 3'UTR were transfected with miR-220b, no reduction of AIRE protein production was observed. Taken together, it was concluded that miR-220b inhibited the AIRE gene translation through the 3'UTR region of AIRE gene, indicating that miR-220b could serve as a regulator for human AIRE gene translation. © 2013.

  12. Air Pollution Emissions Overview | Air Quality Planning & ...

    Science.gov (United States)

    2016-06-08

    Air pollution comes from many different sources: stationary sources such as factories, power plants, and smelters and smaller sources such as dry cleaners and degreasing operations; mobile sources such as cars, buses, planes, trucks, and trains; and naturally occurring sources such as windblown dust, and volcanic eruptions, all contribute to air pollution.

  13. AIRE-mutations and autoimmune disease.

    Science.gov (United States)

    Bruserud, Øyvind; Oftedal, Bergithe E; Wolff, Anette B; Husebye, Eystein S

    2016-12-01

    The gene causing the severe organ-specific autoimmune disease autoimmune polyendocrine syndrome type-1 (APS-1) was identified in 1997 and named autoimmune regulator (AIRE). AIRE plays a key role in shaping central immunological tolerance by facilitating negative selection of T cells in the thymus, building the thymic microarchitecture, and inducing a specific subset of regulatory T cells. So far, about 100 mutations have been identified. Recent advances suggest that certain mutations located in the SAND and PHD1 domains exert a dominant negative effect on wild type AIRE resulting in milder seemingly common forms of autoimmune diseases, including pernicious anemia, vitiligo and autoimmune thyroid disease. These findings indicate that AIRE also contribute to autoimmunity in more common organ-specific autoimmune disorders. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Development and evaluation of carbon and binder loading in low-cost activated carbon cathodes for air-cathode microbial fuel cells

    KAUST Repository

    Wei, Bin

    2012-01-01

    Activated carbon (AC) air cathodes were constructed using variable amounts of carbon (43-171 mg cm-2) and an inexpensive binder (10 wt% polytetrafluoroethylene, PTFE), and with or without a porous cloth wipe-based diffusion layer (DL) that was sealed with PDMS. The cathodes with the highest AC loading of 171 mg cm-2, and no diffusion layer, produced 1255 ± 75 mW m-2 and did not appreciably vary in performance after 1.5 months of operation. Slightly higher power densities were initially obtained using 100 mg cm-2 of AC (1310 ± 70 mW m-2) and a PDMS/wipe diffusion layer, although the performance of this cathode decreased to 1050 ± 70 mW m-2 after 1.5 months, and 1010 ± 190 mW m-2 after 5 months. AC loadings of 43 mg cm-2 and 100 mg cm-2 did not appreciably affect performance (with diffusion layers). MFCs with the Pt catalyst and Nafion binder initially produced 1295 ± 13 mW m-2, but the performance decreased to 930 ± 50 mW m -2 after 1.5 months, and then to 890 ± 20 mW m-2 after 5 months. Cathode performance was optimized for all cathodes by using the least amount of PTFE binder (10%, in tests using up to 40%). These results provide a method to construct cathodes for MFCs that use only inexpensive AC and a PTFE, while producing power densities similar to those of Pt/C cathodes. The methods used here to make these cathodes will enable further tests on carbon materials in order to optimize and extend the lifetime of AC cathodes in MFCs. © 2012 The Royal Society of Chemistry.

  15. Hydrogen /Hydride/-air secondary battery

    Science.gov (United States)

    Sarradin, J.; Bronoel, G.; Percheron-Guegan, A.; Achard, J. C.

    1979-01-01

    The use of metal hydrides as negative electrodes in a hydrogen-air secondary battery seems promising. However, in an unpressurized cell, more stable hydrides that LaNi5H6 must be selected. Partial substitutions of nickel by aluminium or manganese increase the stability of hydrides. Combined with an air reversible electrode, a specific energy close to 100 Wh/kg can be expected.

  16. Air Data - Concentration Map

    Science.gov (United States)

    Make a map of daily concentrations over several days. The daily air quality can be displayed in terms of the Air Quality Index or in concentration ranges for certain PM species like organic carbon, nitrates, and sulfates.

  17. Air Quality Facilities

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — Facilities with operating permits for Title V of the Federal Clean Air Act, as well as facilities required to submit an air emissions inventory, and other facilities...

  18. Nonequilibrium Air Plasma Chemistry

    National Research Council Canada - National Science Library

    Kruger, Charles

    2002-01-01

    .... The goal of the Air Plasma Ramparts program is to investigate energy efficient methods for creating and sustaining large volume atmospheric air plasmas with electron number densities greater than 10(exp 13...

  19. Nuclear air cleaning

    International Nuclear Information System (INIS)

    Bellamy, R.R.

    1994-01-01

    This report briefly describes the history of the use of high- efficiency particulate air filters for air cleaning at nuclear installations in the United States and discusses future uses of such filters

  20. Clean Air Technology Center

    Science.gov (United States)

    The Clean Air Technology Center provides resources for emerging and existing air pollution prevention and control technologies and provides public access to data and information on their use, effectiveness and cost.

  1. AirCompare

    Data.gov (United States)

    U.S. Environmental Protection Agency — AirCompare contains air quality information that allows a user to compare conditions in different localities over time and compare conditions in the same location at...

  2. Lead (Pb) Air Pollution

    Science.gov (United States)

    ... Environmental Protection Agency Search Search Lead (Pb) Air Pollution Contact Us Share As a result of EPA's ... protect aquatic and terrestrial ecosystems. Lead (Pb) Air Pollution Basic Information How does lead get in the ...

  3. Air Quality System (AQS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Air Quality System (AQS) database contains measurements of air pollutant concentrations from throughout the United States and its territories. The measurements...

  4. Allegheny County Air Quality

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Air quality data from Allegheny County Health Department monitors throughout the county. Air quality monitored data must be verified by qualified individuals before...

  5. Investigation of a hybrid PVT air collector system

    Science.gov (United States)

    Haddad, S.; Touafek, K.; Mordjaoui, M.; Khelifa, A.; Tabet, I.

    2017-02-01

    The photovoltaic thermal hybrid (PVT) collectors, which simultaneously produce electricity and heat, are an alternative to photovoltaic modules and thermal collectors installed separately. Indeed, the heat extracted from the solar cell is used to heat water or air, thereby cooling the cell, and thus increasing its energy efficiency. This paper deals with a hybrid PVT air collector in which a new design has been proposed and tested. Its principle is based on the return of the preheating air to a second heating. The air thus passes twice under the solar cells before being evacuated to the outside of the collector (for space heating). The system is modular and expandable to cover large spaces to be heated. The experimental results of this novel design are presented and discussed under both normal and forced circulation. This technique of air return shows favorable results in terms of the quality of the heated air and electric power generation.

  6. Indoor air quality

    DEFF Research Database (Denmark)

    Jensen, Trine Susanne; Recevska, Ieva

     The objective of the 35th specific agreement is to provide support to the EEA activities in Environment and Health (E&H) on the topic of indoor air quality. The specific objectives have been to provide an overview of indoor air related projects in EU and indoor air related policies as well...... as idenfiying "good practices" to reduce health impact of indoor air exposure and suggest areas for future improvements....

  7. AIR NCO's AND AIRMEN

    African Journals Online (AJOL)

    D.F.C. o Proceeded to Cape Town 9:5:22. Left Cape Town for. African Protectorate 25:2:22. J Left for South West African Protectorate 25:2:22. [ Left for South West African Protectorate. 1:6:22. Colonel: Director of Air Services. Air Directorate. 6th June 1922. SOUTH AFRICAN AIR FORCE. NOMINAL ROLL OF AIR W.O.'s,.

  8. The interaction of mefloquine hydrochloride with cell membrane models at the air-water interface is modulated by the monolayer lipid composition.

    Science.gov (United States)

    Goto, Thiago Eichi; Caseli, Luciano

    2014-10-01

    The antiparasitic properties of antiparasitic drugs are believed to be associated with their interactions with the protozoan membrane, encouraging research on the identification of membrane sites capable of drug binding. In this study, we investigated the interaction of mefloquine hydrochloride, known to be effective against malaria, with cell membrane models represented by Langmuir monolayers of selected lipids. It is shown that even small amounts of the drug affect the surface pressure-area isotherms as well as surface vibrational spectra of some lipid monolayers, which points to a significant interaction. The effects on the latter depend on the electrical charge of the monolayer-forming molecules, with the drug activity being particularly distinctive for negatively charged lipids. Therefore, the lipid composition of the monolayer modulates the interaction with the lipophilic drug, which may have important implications in understanding how the drug acts on specific sites of the protozoan membrane. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Air Pollution Training Programs.

    Science.gov (United States)

    Public Health Service (DHEW), Rockville, MD.

    This catalog lists the universities, both supported and not supported by the Division of Air Pollution, which offer graduate programs in the field of air pollution. The catalog briefly describes the programs and their entrance requirements, the requirements, qualifications and terms of special fellowships offered by the Division of Air Pollution.…

  10. Indoor Air Pollution

    Indian Academy of Sciences (India)

    the risks to health may be greater due to indoor air pollution than the outdoor air. ... materials, furnishings, wet or damp carpets, household chemical products, air cond itioners, dehumidifiers and outdoor sources such as radon and pesticides. ... organic compounds are emitted from construction materials, furnishings and ...

  11. Clean Air Act Text

    Science.gov (United States)

    The Clean Air Act is the law that defines EPA's responsibilities for protecting and improving the nation's air quality and the stratospheric ozone layer. The last major change in the law, the Clean Air Act Amendments of 1990, enacted in 1990 by Congress.

  12. Air quality and disease

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Climate change is an important determinant of air quality. Climate change is an important determinant of air quality. Poor air quality associated with higher levels of respiratory and cardiovascular disease. Exposure to high levels of ground-level ozone associated with ...

  13. Indoor Air Pollution

    Science.gov (United States)

    We usually think of air pollution as being outdoors, but the air in your house or office could also be polluted. Sources of indoor pollution ... is known as sick building syndrome. Usually indoor air quality problems only cause discomfort. Most people feel ...

  14. Towards high efficiency air-processed near-infrared responsive photovoltaics: bulk heterojunction solar cells based on PbS/CdS core-shell quantum dots and TiO2 nanorod arrays.

    Science.gov (United States)

    Gonfa, Belete Atomsa; Kim, Mee Rahn; Delegan, Nazar; Tavares, Ana C; Izquierdo, Ricardo; Wu, Nianqiang; El Khakani, My Ali; Ma, Dongling

    2015-06-14

    Near infrared (NIR) PbS quantum dots (QDs) have attracted significant research interest in solar cell applications as they offer several advantages, such as tunable band gaps, capability of absorbing NIR photons, low cost solution processability and high potential for multiple exciton generation. Nonetheless, reports on solar cells based on NIR PbS/CdS core-shell QDs, which are in general more stable and better passivated than PbS QDs and thus more promising for solar cell applications, remain very rare. Herein we report high efficiency bulk heterojunction QD solar cells involving hydrothermally grown TiO2 nanorod arrays and PbS/CdS core-shell QDs processed in air (except for a device thermal annealing step) with a photoresponse extended to wavelengths >1200 nm and with a power conversion efficiency (PCE) as high as 4.43%. This efficiency was achieved by introducing a thin, sputter-deposited, uniform TiO2 seed layer to improve the interface between the TiO2 nanorod arrays and the front electrode, by optimizing TiO2 nanorod length and by conducting QD annealing treatment to enhance charge carrier transport. It was found that the effect of the seed layer became more obvious when the TiO2 nanorods were longer. Although photocurrent did not change much, both open circuit voltage and fill factor clearly changed with TiO2 nanorod length. This was mainly attributed to the variation of charge transport and recombination processes, as evidenced by series and shunt resistance studies. The optimal PCE was obtained at the nanorod length of ∼450 nm. Annealing is shown to further increase the PCE by ∼18%, because of the improvement of charge carrier transport in the devices as evidenced by considerably increased photocurrent. Our results clearly demonstrate the potential of the PbS/CdS core-shell QDs for the achievement of high PCE, solution processable and NIR responsive QD solar cells.

  15. Towards high efficiency air-processed near-infrared responsive photovoltaics: bulk heterojunction solar cells based on PbS/CdS core-shell quantum dots and TiO2 nanorod arrays

    Science.gov (United States)

    Gonfa, Belete Atomsa; Kim, Mee Rahn; Delegan, Nazar; Tavares, Ana C.; Izquierdo, Ricardo; Wu, Nianqiang; El Khakani, My Ali; Ma, Dongling

    2015-05-01

    Near infrared (NIR) PbS quantum dots (QDs) have attracted significant research interest in solar cell applications as they offer several advantages, such as tunable band gaps, capability of absorbing NIR photons, low cost solution processability and high potential for multiple exciton generation. Nonetheless, reports on solar cells based on NIR PbS/CdS core-shell QDs, which are in general more stable and better passivated than PbS QDs and thus more promising for solar cell applications, remain very rare. Herein we report high efficiency bulk heterojunction QD solar cells involving hydrothermally grown TiO2 nanorod arrays and PbS/CdS core-shell QDs processed in air (except for a device thermal annealing step) with a photoresponse extended to wavelengths >1200 nm and with a power conversion efficiency (PCE) as high as 4.43%. This efficiency was achieved by introducing a thin, sputter-deposited, uniform TiO2 seed layer to improve the interface between the TiO2 nanorod arrays and the front electrode, by optimizing TiO2 nanorod length and by conducting QD annealing treatment to enhance charge carrier transport. It was found that the effect of the seed layer became more obvious when the TiO2 nanorods were longer. Although photocurrent did not change much, both open circuit voltage and fill factor clearly changed with TiO2 nanorod length. This was mainly attributed to the variation of charge transport and recombination processes, as evidenced by series and shunt resistance studies. The optimal PCE was obtained at the nanorod length of ~450 nm. Annealing is shown to further increase the PCE by ~18%, because of the improvement of charge carrier transport in the devices as evidenced by considerably increased photocurrent. Our results clearly demonstrate the potential of the PbS/CdS core-shell QDs for the achievement of high PCE, solution processable and NIR responsive QD solar cells.Near infrared (NIR) PbS quantum dots (QDs) have attracted significant research interest in

  16. Manual for THOR-AirPAS - air pollution assessment system

    DEFF Research Database (Denmark)

    Jensen, Steen Solvang; Ketzel, Matthias; Brandt, Jørgen

    The report provides an outline of the THOR-AirPAS - air pollution assessment system and a brief manual for getting started with the air quality models and input data included in THOR-AirPAS.......The report provides an outline of the THOR-AirPAS - air pollution assessment system and a brief manual for getting started with the air quality models and input data included in THOR-AirPAS....

  17. Advanced air distribution

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor

    2011-01-01

    The aim of total volume air distribution (TVAD) involves achieving uniform temperature and velocity in the occupied zone and environment designed for an average occupant. The supply of large amounts of clean and cool air are needed to maintain temperature and pollution concentration at acceptable....... Ventilation in hospitals is essential to decrease the risk of airborne cross-infection. At present, mixing air distribution at a minimum of 12 ach is used in infection wards. Advanced air distribution has the potential to aid in achieving healthy, comfortable and productive indoor environments at levels...... higher than what can be achieved today with the commonly used total volume air distribution principles....

  18. Air-water screen

    Energy Technology Data Exchange (ETDEWEB)

    Prokopov, O.I.; Kutepov, A.I.

    1980-12-08

    The air-water screen based on inventor's certificate No. 577364 contains horizontal water and air lines with water and air nozzles. The air line is situated inside the water line eccentrically and contracts it in the area of the nozzle, whose orifices are situated along the line of contact, while the orifices of the water nozzle are situated symmetrically relative to the air orifices and are located at an acute angle to them. To raise the protective properties, on the end of the water line is a lateral nozzle water distributor is an additional nozzle, connected to this container.

  19. Optimum spacing between electrodes in an air-cathode single chamber microbial fuel cell with a low-cost polypropylene separator.

    Science.gov (United States)

    Kondaveeti, Sanath; Moon, Jung Mi; Min, Booki

    2017-12-01

    The performance of a single chamber microbial fuel cell (MFC) with a low-cost polypropylene separator was investigated at various electrode interspaces in a separator electrode assembly (SEA). The lag period was shortened (3.74-0.17 days) and voltage generation was enhanced (0.2-0.5 V) as electrode spacing was increased from 0 to 9 mm. Power density was increased from 220 to 370 mW/m 2 with increased spacing. The highest power density of 488 mW/m 2 was obtained in polarization analysis with 6 mm. The oxygen mass transfer coefficients with 0 mm (K o  = 3.69 × 10 -5  cm/s) electrode spacing were 3.8 times higher than with 9 mm (K o  = 0.96 × 10 -5  cm/s) spacing. Columbic efficiency (CE) was increased from 5 to 32% due to less oxygen diffusion with increase in electrode spacing, but on contrary the ohmic resistance (R oh ) was increased from 2 to 4 Ω. In a long-term operation (200 days), a gradual decrease in cathode potentials was observed in all electrode spacing as the main limiting factor of stable MFC performance.

  20. Spray-on polyvinyl alcohol separators and impact on power production in air-cathode microbial fuel cells with different solution conductivities

    KAUST Repository

    Hoskins, Daniel L.

    2014-11-01

    © 2014 Elsevier Ltd. Separators are used to protect cathodes from biofouling and to avoid electrode short-circuiting, but they can adversely affect microbial fuel cell (MFC) performance. A spray method was used to apply a polyvinyl alcohol (PVA) separator to the cathode. Power densities were unaffected by the PVA separator (339 ± 29 mW/m2), compared to a control lacking a separator in a low conductivity solution (1mS/cm) similar to wastewater. Power was reduced with separators in solutions typical of laboratory tests (7-13 mS/cm), compared to separatorless controls. The PVA separator produced more power in a separator assembly (SEA) configuration (444 ± 8 mW/m2) in the 1mS/cm solution, but power was reduced if a PVA or wipe separator was used in higher conductivity solutions with either Pt or activated carbon catalysts. Spray and cast PVA separators performed similarly, but the spray method is preferred as it was easier to apply and use.

  1. UV air cleaners and upper-room air ultraviolet germicidal irradiation for controlling airborne bacteria and fungal spores.

    Science.gov (United States)

    Kujundzic, Elmira; Matalkah, Fatimah; Howard, Cody J; Hernandez, Mark; Miller, Shelly L

    2006-10-01

    In-room air cleaners (ACs) and upper-room air ultraviolet germicidal irradiation (UVGI) are engineering control technologies that can help reduce the concentrations of airborne bacteria and fungal spores in the indoor environment. This study investigated six different types of ACs and quantified their ability to remove and/or inactivate airborne bacteria and fungal spores. Four of the air cleaners incorporated UV lamp(s) into their flow path. In addition, the efficacy of combining ACs with upper-room air UVGI was investigated. With the ventilation system providing zero or six air changes per hour, the air cleaners were tested separately or with the upper-room air UVGI system in operation in an 87-m3 test room. Active bacteria cells and fungal spores were aerosolized into the room such that their numbers and physiologic state were comparable both with and without air cleaning and upper-room air UVGI. In addition, the disinfection performance of a UV-C lamp internal to one of the ACs was evaluated by estimating the percentage of airborne bacteria cells and fungal spores captured on the air filter medium surface that were inactivated with UV exposure. Average airborne microbial clean air delivery rates (CADRm) varied between 26-981 m3 hr-1 depending on the AC, and between 1480-2370 m3 hr-1, when using air cleaners in combination with upper-room air UVGI. Culturing, direct microscopy, and optical particle counting revealed similar CADRm. The ACs performed similarly when challenged with three different microorganisms. Testing two of the ACs showed that no additional air cleaning was provided with the operation of an internal UV-C lamp; the internal UV-C lamps, however, inactivated 75% of fungal spores and 97% of bacteria cells captured in the air filter medium within 60 min.

  2. Air Conditioner/Dehumidifier

    Science.gov (United States)

    1986-01-01

    An ordinary air conditioner in a very humid environment must overcool the room air, then reheat it. Mr. Dinh, a former STAC associate, devised a heat pipe based humidifier under a NASA Contract. The system used heat pipes to precool the air; the air conditioner's cooling coil removes heat and humidity, then the heat pipes restore the overcooled air to a comfortable temperature. The heat pipes use no energy, and typical savings are from 15-20%. The Dinh Company also manufactures a "Z" coil, a retrofit cooling coil which may be installed on an existing heater/air conditioner. It will also provide free hot water. The company has also developed a photovoltaic air conditioner and solar powered water pump.

  3. Performance of three pilot-scale immobilized-cell biotrickling filters for removal of hydrogen sulfide from a contaminated air steam.

    Science.gov (United States)

    Chen, Yiqing; Fan, Zhidong; Ma, Lixia; Yin, Juan; Luo, Man; Cai, Wangfeng

    2014-11-01

    Hydrogen sulfide (H2S) is a major malodorous compound emitted from wastewater treatment plants. In this study, the performance of three pilot-scale immobilized-cell biotrickling filters (BTFs) spacked with combinations of bamboo charcoal and ceramsite in different ratios was investigated in terms of H2S removal. Extensive tests were performed to determine the removal characteristics, pressure drops, metabolic products, and removal kinetics of the BTFs. The BTFs were operated in continuous mode at low loading rates varying from 0.59 to 5.00 g H2S m(-3) h(-1) with an empty bed retention time (EBRT) of 25 s. The removal efficiency (RE) for each BTF was >99% in the steady-state period, and high standards were met for the exhaust gas. It was found that a multilayer BTF had a slight advantage over a perfectly mixed BTF for the removal of H2S. Furthermore, an impressive amount >97% of the H2S was eliminated by 10% of packing materials near the inlet of the BTF. The modified Michaelis-Menten equation was adopted to describe the characteristics of the BTF, and K s and V m values for the BTF with pure bamboo charcoal packing material were 3.68 ppmv and 4.26 g H2S m(-3) h(-1), respectively. Both bamboo charcoal and ceramsite demonstrated good performance as packing materials in BTFs for the removal of H2S, and the results of this study could serve as a guide for further design and operation of industrial-scale systems.

  4. Investigations on cytotoxic and genotoxic effects of laser printer emissions in human epithelial A549 lung cells using an air/liquid exposure system.

    Science.gov (United States)

    Tang, Tao; Gminski, Richard; Könczöl, Mathias; Modest, Christoph; Armbruster, Benedikt; Mersch-Sundermann, Volker

    2012-03-01

    Exposure to emissions from laser printers during the printing process is commonplace worldwide, both in the home and workplace environment. In the present study, cytotoxic and genotoxic effects of the emission from five low to medium-throughput laser printers were investigated with respect to the release of ozone (O(3) ), volatile organic compounds (VOC), particulate matter (PM), and submicrometer particles (SMP) during standby and operation. Experiments were conducted in a 1 m(3) emission chamber connected to a Vitrocell® exposure system. Cytotoxicity was determined by the WST-1 assay and genotoxicity by the micronucleus test in human A549 lung cells. The five laser printers emitted varying but generally small amounts of O(3) , VOC, and PM. VOC emissions included 13 compounds with total VOC concentrations ranging from 95 to 280 μg/m(3) (e.g., 2-butanone, hexanal, m,p-xylene, and o-xylene). Mean PM concentrations were below 2.4 μg/m(3). SMP number concentration levels during standby ranged from 9 to 26 particles/cm(3). However, three of the printers generated a 90 to 16 × 10(3) -fold increase of SMP during the printing process (maximum 294,460 particles/cm(3)). Whereas none of the printer emissions were found to cause cytotoxicity, emissions from two printers induced formation of micronuclei (P printers. Because laser printing technology is widely used, studies with additional cytogenetic endpoints are necessary to confirm the DNA-damaging potency and to identify emission components responsible for genotoxicity. Copyright © 2011 Wiley-Liss, Inc.

  5. Air filtration in HVAC systems

    CERN Document Server

    Ginestet, Alain; Tronville, Paolo; Hyttinen, Marko

    2010-01-01

    Air filtration Guidebook will help the designer and user to understand the background and criteria for air filtration, how to select air filters and avoid problems associated with hygienic and other conditions at operation of air filters. The selection of air filters is based on external conditions such as levels of existing pollutants, indoor air quality and energy efficiency requirements.

  6. Study of the Nafion quantity effect in membrane and electrodes assemblies (MEAs) of 50 cm{sup 2} used in type proton exchange membrane (PEM) fuel cell operating with H{sub 2}/Air; Estudo do efeito da quantidade de Nafion em MEAs de 50 cm{sup 2} utilizadas em celula a combustivel tipo PEM operando com H{sub 2}/ar

    Energy Technology Data Exchange (ETDEWEB)

    Profeti, Demetrius; Colmati, Flavio; Carlindo, Adao A.J.; Paganin, Valdecir A.; Gonzalez, Ernesto R.; Ticianelli, Edson A. [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Inst. de Quimica]. E-mail: dprofeti@iqsc.usp.br

    2008-07-01

    The performance of a proton exchange membrane fuel cell (PEMFC) was investigated with the aim at characterizing the effects of the Nafion. content on the scale-up of the electrodes from 5 to 50 cm{sup 2}. It is observed that a diminution of the single cell performance occurred when the electrode area is increased from 5 to 50 cm{sup 2}. The tests carried out with different Nafion. contents, and fuel cell and humidifiers at the same temperature (T{sub cell}=T{sub H2}=T{sub air}=70 deg C) showed a slightly decrease of the fuel cell performance compared to the tests performed at different temperatures (T{sub cell}=70 deg C, T{sub H2}=85 deg C, T{sub air}=75 deg C). In the study of the variation on the Nafion. contents, the higher performance up to a current density of 0.8 A cm-2 is obtained with the 35.5 wt.% Nafion.. On the other hand, at higher current densities values, the performance of the fuel cells is very similar for the 31.0, 35.5 and 39.4 wt.% Nafion contents. (author)

  7. Understanding the degradation of Congo red and bacterial diversity in an air-cathode microbial fuel cell being evaluated for simultaneous azo dye removal from wastewater and bioelectricity generation.

    Science.gov (United States)

    Sun, Jian; Li, Youming; Hu, Yongyou; Hou, Bin; Zhang, Yaping; Li, Sizhe

    2013-04-01

    We investigated the mechanism of Congo red degradation and bacterial diversity in a single-chambered microbial fuel cell (MFC) incorporating a microfiltration membrane and air-cathode. The MFC was operated continuously for more than 4 months using a mixture of Congo red and glucose as fuel. We demonstrated that the Congo red azo bonds were reduced at the anode to form aromatic amines. This is consistent with the known mechanism of anaerobic biodegradation of azo dyes. The MFC developed a less dense biofilm at the anode in the presence of Congo red compared to its absence indicating that Congo red degradation negatively affected biofilm formation. Denaturing gradient gel electrophoresis and direct 16S ribosomal DNA gene nucleotide sequencing revealed that the microbial communities differed depending on whether Congo red was present in the MFC. Geobacter-like species known to generate electricity were detected in the presence or absence of Congo red. In contrast, Azospirillum, Methylobacterium, Rhodobacter, Desulfovibrio, Trichococcus, and Bacteroides species were only detected in its presence. These species were most likely responsible for degrading Congo red.

  8. Air pollution and brain damage.

    Science.gov (United States)

    Calderón-Garcidueñas, Lilian; Azzarelli, Biagio; Acuna, Hilda; Garcia, Raquel; Gambling, Todd M; Osnaya, Norma; Monroy, Sylvia; DEL Tizapantzi, Maria Rosario; Carson, Johnny L; Villarreal-Calderon, Anna; Rewcastle, Barry

    2002-01-01

    Exposure to complex mixtures of air pollutants produces inflammation in the upper and lower respiratory tract. Because the nasal cavity is a common portal of entry, respiratory and olfactory epithelia are vulnerable targets for toxicological damage. This study has evaluated, by light and electron microscopy and immunohistochemical expression of nuclear factor-kappa beta (NF-kappaB) and inducible nitric oxide synthase (iNOS), the olfactory and respiratory nasal mucosae, olfactory bulb, and cortical and subcortical structures from 32 healthy mongrel canine residents in Southwest Metropolitan Mexico City (SWMMC), a highly polluted urban region. Findings were compared to those in 8 dogs from Tlaxcala, a less polluted, control city. In SWMMC dogs, expression of nuclear neuronal NF-kappaB and iNOS in cortical endothelial cells occurred at ages 2 and 4 weeks; subsequent damage included alterations of the blood-brain barrier (BBB), degenerating cortical neurons, apoptotic glial white matter cells, deposition of apolipoprotein E (apoE)-positive lipid droplets in smooth muscle cells and pericytes, nonneuritic plaques, and neurofibrillary tangles. Persistent pulmonary inflammation and deteriorating olfactory and respiratory barriers may play a role in the neuropathology observed in the brains of these highly exposed canines. Neurodegenerative disorders such as Alzheimer's may begin early in life with air pollutants playing a crucial role.

  9. Microfluidic liquid-air dual-gradient chip for synergic effect bio-evaluation of air pollutant.

    Science.gov (United States)

    Liu, Xian-Jun; Hu, Shan-Wen; Xu, Bi-Yi; Zhao, Ge; Li, Xiang; Xie, Fu-Wei; Xu, Jing-Juan; Chen, Hong-Yuan

    2018-05-15

    In this paper, a novel prototype liquid-air dual gradient chip is introduced, which has paved the way for effective synergic effect bio-evaluation of air pollutant. The chip is composed of an array of the agarose liquid-air interfaces, top air gradient layer and bottom liquid gradient layer. The novel agarose liquid-air interface allows for non-biased exposure of cells to all the substances in the air and diffusive interactions with the liquid phase; while the dual liquid-air gradient provides powerful screening abilities, which well reduced errors, saved time and cost from repeated experiment. Coupling the two functions, the chip subsequently facilitates synergic effect evaluation of both liquid and air factors on cells. Here cigarette smoke was taken as the model air pollutant, and its strong synergic effects with inflammatory level of A549 lung cancer cells on their fate were successfully quantified for the first time. These results well testified that the proposed dual-gradient chip is powerful and indispensable for bio-evaluation of air pollutant. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Radioactive material air transportation

    International Nuclear Information System (INIS)

    Pader y Terry, Claudio Cosme

    2002-01-01

    As function of the high aggregated value, safety regulations and the useful life time, the air transportation has been used more regularly because is fast, reliable, and by giving great security to the cargo. Based on the International Atomic Energy Agency (IAEA), the IATA (International Air Transportation Association) has reproduced in his dangerous goods manual (Dangerous Goods Regulations - DGR IATA), the regulation for the radioactive material air transportation. Those documents support this presentation

  11. Air Power and Warfare

    Science.gov (United States)

    1978-09-01

    American air ace.- New York: Putnam , 1958. (UG!3 290 G98) Guild, Richard E. The double attack system: a formalization. Yokota Air Base, Japan, 1968...1962) Sa..dby;•Robert H.M.S. Air bombardment: the story of it- development New York: Harper, 1961. (UGK 207 S25) Saunders, Hilary A.S. .Per ardua; the...1961. Letchworth, Herts: Harleyford Publications, 1961. (UGH 3215 .F5 887) Bruce, John N. British ,aeroplance 1914-1918. London: Putnam ; 1957. (Ref

  12. Olefin metathesis in air.

    Science.gov (United States)

    Piola, Lorenzo; Nahra, Fady; Nolan, Steven P

    2015-01-01

    Since the discovery and now widespread use of olefin metathesis, the evolution of metathesis catalysts towards air stability has become an area of significant interest. In this fascinating area of study, beginning with early systems making use of high oxidation state early transition metal centers that required strict exclusion of water and air, advances have been made to render catalysts more stable and yet more functional group tolerant. This review summarizes the major developments concerning catalytic systems directed towards water and air tolerance.

  13. Bad traffic, bad air

    OpenAIRE

    Duca, Edward

    2012-01-01

    Air pollution is one of Malta’s greatest concerns. Transportation is the principal source with over 300,000 vehicles belching out smoke, which damages our environment and health. Emissions from vehicles need to be monitored and controlled, and the information used to improve the current system and ensure an acceptable air quality. By using the pollution data set, Nicolette Formosa (supervised by Dr Kenneth Scerri) mapped the air pollution levels and major sources around Malta. http://www....

  14. Air pollution engineering

    Science.gov (United States)

    Maduna, Karolina; Tomašić, Vesna

    2017-11-01

    Air pollution is an environmental and a social problem which leads to a multitude of adverse effects on human health and standard of human life, state of the ecosystems and global change of climate. Air pollutants are emitted from natural, but mostly from anthropogenic sources and may be transported over long distances. Some air pollutants are extremely stable in the atmosphere and may accumulate in the environment and in the food chain, affecting human beings, animals and natural biodiversity. Obviously, air pollution is a complex problem that poses multiple challenges in terms of management and abatements of the pollutants emission. Effective approach to the problems of air pollution requires a good understanding of the sources that cause it, knowledge of air quality status and future trends as well as its impact on humans and ecosystems. This chapter deals with the complexities of the air pollution and presents an overview of different technical processes and equipment for air pollution control, as well as basic principles of their work. The problems of air protection as well as protection of other ecosystems can be solved only by the coordinated endeavors of various scientific and engineering disciplines, such as chemistry, physics, biology, medicine, chemical engineering and social sciences. The most important engineering contribution is mostly focused on development, design and operation of equipment for the abatement of harmful emissions into environment.

  15. Applications Using AIRS Data

    Science.gov (United States)

    Ray, S. E.; Pagano, T. S.; Fetzer, E. J.; Lambrigtsen, B.; Olsen, E. T.; Teixeira, J.; Licata, S. J.; Hall, J. R.; Thompson, C. K.

    2015-12-01

    The Atmospheric Infrared Sounder (AIRS) on NASA's Aqua spacecraft has been returning daily global observations of Earth's atmospheric constituents and properties since 2002. With a 12-year data record and daily, global observations in near real-time, AIRS data can play a role in applications that fall under many of the NASA Applied Sciences focus areas. For vector-borne disease, research is underway using AIRS near surface retrievals to assess outbreak risk, mosquito incubation periods and epidemic potential for dengue fever, malaria, and West Nile virus. For drought applications, AIRS temperature and humidity data are being used in the development of new drought indicators and improvement in the understanding of drought development. For volcanic hazards, new algorithms using AIRS data are in development to improve the reporting of sulfur dioxide concentration, the burden and height of volcanic ash and dust, all of which pose a safety threat to aircraft. In addition, anomaly maps of many of AIRS standard products are being produced to help highlight "hot spots" and illustrate trends. To distribute it's applications imagery, AIRS is leveraging existing NASA data frameworks and organizations to facilitate archiving, distribution and participation in the BEDI. This poster will communicate the status of the applications effort for the AIRS Project and provide examples of new maps designed to best communicate the AIRS data.

  16. Air pollution meteorology

    International Nuclear Information System (INIS)

    Shirvaikar, V.V.; Daoo, V.J.

    2002-06-01

    This report is intended as a training cum reference document for scientists posted at the Environmental Laboratories at the Nuclear Power Station Sites and other sites of the Department of Atomic Energy with installations emitting air pollutants, radioactive or otherwise. Since a manual already exists for the computation of doses from radioactive air pollutants, a general approach is take here i.e. air pollutants in general are considered. The first chapter presents a brief introduction to the need and scope of air pollution dispersion modelling. The second chapter is a very important chapter discussing the aspects of meteorology relevant to air pollution and dispersion modelling. This chapter is important because without this information one really does not understand the phenomena affecting dispersion, the scope and applicability of various models or their limitations under various weather and site conditions. The third chapter discusses the air pollution models in detail. These models are applicable to distances of a few tens of kilometres. The fourth chapter discusses the various aspects of meteorological measurements relevant to air pollution. The chapters are followed by two appendices. Apendix A discusses the reliability of air pollution estimates. Apendix B gives some practical examples relevant to general air pollution. It is hoped that the document will prove very useful to the users. (author)

  17. Crowdsourcing urban air temperature measurements using smartphones

    Science.gov (United States)

    Balcerak, Ernie

    2013-10-01

    Crowdsourced data from cell phone battery temperature sensors could be used to contribute to improved real-time, high-resolution air temperature estimates in urban areas, a new study shows. Temperature observations in cities are in some cases currently limited to a few weather stations, but there are millions of smartphone users in many cities. The batteries in cell phones have temperature sensors to avoid damage to the phone.

  18. Analysis of reaction and transport processes in zinc air batteries

    CERN Document Server

    Schröder, Daniel

    2016-01-01

    This book contains a novel combination of experimental and model-based investigations, elucidating the complex processes inside zinc air batteries. The work presented helps to answer which battery composition and which air-composition should be adjusted to maintain stable and efficient charge/discharge cycling. In detail, electrochemical investigations and X-ray transmission tomography are applied on button cell zinc air batteries and in-house set-ups. Moreover, model-based investigations of the battery anode and the impact of relative humidity, active operation, carbon dioxide and oxygen on zinc air battery operation are presented. The techniques used in this work complement each other well and yield an unprecedented understanding of zinc air batteries. The methods applied are adaptable and can potentially be applied to gain further understanding of other metal air batteries. Contents Introduction on Zinc Air Batteries Characterizing Reaction and Transport Processes Identifying Factors for Long-Term Stable O...

  19. A study of mercuric oxide and zinc-air battery life in hearing aids.

    Science.gov (United States)

    Sparkes, C; Lacey, N K

    1997-09-01

    The requirement to phase out mercuric oxide (mercury) batteries on environmental grounds has led to the widespread introduction of zinc-air technology. The possibility arises that high drain hearing aids may not be adequately catered for by zinc-air cells, leading to poor performance. This study investigated the hearing aid user's ability to perceive differences between zinc-air and mercury cells in normal everyday usage. The data was collected for 100 experienced hearing aid users in field trials. Users report 50 per cent greater life for zinc-air cells in high power aids and 28 per cent in low power aids. The average life of the zinc-air cells range from 15 days in high power to 34 days in low power aids. Users are able to perceive a difference in sound quality in favour of zinc-air cells for low and medium power aids. The hearing aid population is not disadvantaged by phasing out mercury cells.

  20. Restoran Buenos Aires = Restaurant Buenos Aires

    Index Scriptorium Estoniae

    2008-01-01

    Restorani Buenos Aires (Narva mnt. 5, Tallinn) sisekujundusest. Sisearhitektid: Janno Roos ja Andres Labi (Ruumilabor OÜ). Laudu eraldavad 400 vardasse aetud puukuuli. Sisearhitektidest, nende tähtsamad tööd. I-III korruse plaan, 12 värv. vaadet, fotod sisearhitektidest

  1. Protective air lock

    International Nuclear Information System (INIS)

    Evans, H.W.

    1976-01-01

    A device suitable for preventing escape and subsequent circulation of toxic gases is described. An enclosure is sealed by a surrounding air lock, and an automatic mechanism partially evacuates the enclosure and air lock. The enclosure ventilating mechanism can be disconnected so that a relatively undisturbed atmosphere is created in the enclosure

  2. Air Pollution Primer.

    Science.gov (United States)

    National Tuberculosis and Respiratory Disease Association, New York, NY.

    As the dangers of polluted air to the health and welfare of all individuals became increasingly evident and as the complexity of the causes made responsibility for solutions even more difficult to fix, the National Tuberculosis and Respiratory Disease Association felt obligated to give greater emphasis to its clean air program. To this end they…

  3. Air Pollution and Industry.

    Science.gov (United States)

    Ross, R. D., Ed.

    This book is an authoritative reference and practical guide designed to help the plant engineer identify and solve industrial air pollution problems in order to be able to meet current air pollution regulations. Prepared under the editorial supervision of an experienced chemical engineer, with each chapter contributed by an expert in his field,…

  4. Air Cargo Marketing Development

    Science.gov (United States)

    Kersey, J. W.

    1972-01-01

    The factors involved in developing a market for air cargo services are discussed. A comparison is made between the passenger traffic problems and those of cargo traffic. Emphasis is placed on distribution analyses which isolates total distribution cost, including logistical costs such as transportation, inventory, materials handling, packaging, and processing. Specific examples of methods for reducing air cargo costs are presented.

  5. Energy and air quality

    International Nuclear Information System (INIS)

    1981-12-01

    This is one of a series of handbooks designed to provide nontechnical readers with a general understanding of the interaction between energy development and environmental media and to provide a rudimentary data base from which estimates of potential future impacts can be made. This handbook describes the air quality impacts of energy development and summarizes the major federal legislation which regulates the potential air quality impacts of energy facilities and can thus influence the locations and timing of energy development. In addition, this report describes and presents the data which can be used as the basis for measurement, and in some cases, prediction of the potential conflicts between energy development and achieving and maintaining clean air. Energy utilization is the largest emission source of man-made air pollutants. Choices in energy resource development and utilization generate varying emissions or discharges into the atmosphere, the emissions are affected by the assimilative character of the atmosphere, and the resultant air pollutant concentrations have biological and aesthetic effects. This handbook describes the interrelationships of energy-related air emissions under various methods of pollution control, the assimilative character of the air medium, and the effects of air pollution. The media book is divided into three major sections: topics of concern relating to the media and energy development, descriptions of how to use available data to quantify and examine energy/environmental impacts, and the data

  6. Air Pollution, Teachers' Edition.

    Science.gov (United States)

    Lavaroni, Charles W.; O'Donnell, Patrick A.

    One of three in a series about pollution, this teacher's guide for a unit on air pollution is designed for use in junior high school grades. It offers suggestions for extending the information and activities contained in the textual material for students. Chapter 1 discusses the problem of air pollution and involves students in processes of…

  7. Indoor Air Pollution

    Indian Academy of Sciences (India)

    Airforce. His hobbies include reading books and listening to music. Keywords. Indoor air pollution. GENERAL I ARTICLE. Indoor Air Pollution. Danger at Home ... concentration of. VOCs and it is also a source of stable inorganic gases. GENERAL I ARTICLE which homes are built. Radon is a product of radioactive decay.

  8. Over the air test

    DEFF Research Database (Denmark)

    2015-01-01

    [1] This invention relates to over-the-air testing of a device in an anechoic chamber. In particular, the invention is suitable for simulating both uplink and downlink over-the-air communication with a device under test even when the anechoic chamber has different numbers of uplink and downlink...

  9. AIR RADIOACTIVITY MONITOR

    Science.gov (United States)

    Bradshaw, R.L.; Thomas, J.W.

    1961-04-11

    The monitor is designed to minimize undesirable background buildup. It consists of an elongated column containing peripheral electrodes in a central portion of the column, and conduits directing an axial flow of radioactively contaminated air through the center of the column and pure air through the annular portion of the column about the electrodes. (AEC)

  10. Culture systems: air quality.

    Science.gov (United States)

    Thomas, Theodore

    2012-01-01

    Poor laboratory air quality is a known hazard to the culture of human gametes and embryos. Embryologists and chemists have employed analytical methods for identifying and measuring bulk and select air pollutants to assess the risk they pose to the embryo culture system. However, contaminant concentrations that result in gamete or embryotoxicity are poorly defined. Combating the ill effects of poor air quality requires an understanding of how toxicants can infiltrate the laboratory, the incubator, and ultimately the culture media. A further understanding of site-specific air quality can then lead to the consideration of laboratory design and management strategies that can minimize the deleterious effects that air contamination may have on early embryonic development in vitro.

  11. Airing 'clean air' in Clean India Mission.

    Science.gov (United States)

    Banerjee, T; Kumar, M; Mall, R K; Singh, R S

    2017-03-01

    The submission explores the possibility of a policy revision for considering clean air quality in recently launched nationwide campaign, Clean India Mission (CIM). Despite of several efforts for improving availability of clean household energy and sanitation facilities, situation remain still depressing as almost half of global population lacks access to clean energy and proper sanitation. Globally, at least 2.5 billion people do not have access to basic sanitation facilities. There are also evidences of 7 million premature deaths by air pollution in year 2012. The situation is even more disastrous for India especially in rural areas. Although, India has reasonably progressed in developing sanitary facilities and disseminating clean fuel to its urban households, the situation in rural areas is still miserable and needs to be reviewed. Several policy interventions and campaigns were made to improve the scenario but outcomes were remarkably poor. Indian census revealed a mere 31% sanitation coverage (in 2011) compared to 22% in 2001 while 60% of population (700 million) still use solid biofuels and traditional cook stoves for household cooking. Further, last decade (2001-2011) witnessed the progress decelerating down with rural households without sanitation facilities increased by 8.3 million while minimum progress has been made in conversion of conventional to modern fuels. To revamp the sanitation coverage, an overambitious nationwide campaign CIM was initiated in 2014 and present submission explores the possibility of including 'clean air' considerations within it. The article draws evidence from literatures on scenarios of rural sanitation, energy practises, pollution induced mortality and climatic impacts of air pollution. This subsequently hypothesised with possible modification in available technologies, dissemination modes, financing and implementation for integration of CIM with 'clean air' so that access to both sanitation and clean household energy may be

  12. Health Effects of Air Pollution

    Science.gov (United States)

    ... at https://www.opm.gov/ . Section navigation The environment and your health: Green living Sun Water Air Health effects of air pollution How to protect yourself from air pollution Chemicals Noise Quizzes Links to more ... The environment and your health Air Health effects of air ...

  13. A Micro Hydrogen Air Fuel Cell

    National Research Council Canada - National Science Library

    Savinell, Robert F; Wainright, Jesse S

    2005-01-01

    .... The result will be a device capable of providing on-board electrical power for microelectronic circuits, sensors, and actuators with energy storage and power delivery capabilities considerably...

  14. A Micro Hydrogen Air Fuel Cell

    Science.gov (United States)

    2005-10-01

    process. As an alternative, 13 we are also considering depositing the catalyst layers by thick film printing of catalyst / ionomer inks. These inks...have a favorable environment for electrode reaction kinetics, and must permit gas access to the polymer- catalyst interface so reaction can occur. In a...based Catalyst varies 45 minutes Electrolyte 15 mil 0 mil 6 lbs. 40% Nafion in EG 110°C 20 minutes Cathode 10 mil 1 mil 6 lbs. DEG based Catalyst 110°C 10

  15. Air Baltic: Estonian Air on nurka surutud / Teele Tammeorg

    Index Scriptorium Estoniae

    Tammeorg, Teele

    2010-01-01

    Air Balticu asepresidendi Janis Vanagsi hinnangul on Estonian Air aastaid jätnud tähelepanuta oma peamised turismiturud ning on praegu halvas seisus. Air Baltic on endiselt huvitatud Estonian Airi ostust. Majandus- ja kommunikatsiooniminister Juhan Partsi seisukoht

  16. Aire deficiency causes increased susceptibility to streptozotocin-induced murine type 1 diabetes.

    Science.gov (United States)

    Hässler, S; Peltonen, L; Sandler, S; Winqvist, O

    2008-06-01

    Aire-deficient mice are a model of the human monogenic disorder autoimmune polyendocrine syndrome type I (APS I) characterized by a progressive autoimmune destruction of multiple endocrine glands such as the adrenal cortex, the parathyroids and the beta-cells of the pancreas. The disease is caused by mutations in the autoimmune regulator (AIRE) gene, a putative transcription factor expressed in thymic medullary epithelial cells and in antigen-presenting cells of the myeloid lineage in peripheral lymphoid organs. As Aire(-/-) mice do not spontaneously develop endocrinopathies, we wanted to evaluate the autoimmune multiple low-dose streptozotocin (MLDSTZ) diabetes model in Aire(-/-) mice. Surprisingly, Aire heterozygote mice were most susceptible to MLDSTZ-induced diabetes, whereas Aire(-/-) mice displayed an intermediate sensitivity to diabetes. Furthermore, Aire(-/-) macrophages produced higher levels of TNF-alpha and lower levels of IL-10 following streptozotocin stimulation, and Aire(-/-) mice developed a higher frequency of islet cells autoantibodies as a sign of increased activation. However, the number of islet infiltrating F4/80(+) Aire(-/-) macrophages was significantly decreased which was attributed to an increased susceptibility to streptozotocin cytotoxicity of Aire(-/-) macrophages. In conclusion, Aire(-/-) macrophages display an increased activation after STZ stimuli, but suffer from increased susceptibility to STZ cytotoxicity. These results support an important function of Aire in the control of peripheral tolerance through myeloid antigen-presenting cells.

  17. Air ejector augmented compressed air energy storage system

    Science.gov (United States)

    Ahrens, F.W.; Kartsounes, G.T.

    Energy is stored in slack demand periods by charging a plurality of underground reservoirs with air to the same peak storage pressure, during peak demand periods throttling the air from one storage reservoir into a gas turbine system at a constant inlet pressure until the air presure in the reservoir falls to said constant inlet pressure, thereupon permitting air in a second reservoir to flow into said gas turbine system while drawing air from the first reservoir through a variable geometry air ejector and adjusting said variable geometry air ejector, said air flow being essentially at the constant inlet pressure of the gas turbine system.

  18. Controlled air incineration

    International Nuclear Information System (INIS)

    Seitz, K.A.

    1991-01-01

    From 1960 to 1970, incineration was recognized as an economical method of solid waste disposal with many incinerators in operation through the country. During this period a number of legislation acts began to influence the solid waste disposal industry, namely, the Solid Waste Disposal Act of 1965; Resource Conservation Recovery Act (RCRA) of 1968; Resource Recovery Act of 1970; and Clean Air Act of 1970. This period of increased environmental awareness and newly created regulations began the closure of many excess air incineration facilities and encouraged the development of new controlled air, also known as Starved-Air incinerator systems which could meet the more stringent air emission standards without additional emission control equipment. The Starved-Air technology initially received little recognition because it was considered unproven and radically different from the established and accepted I.I.A. standards. However, there have been many improvements and developments in the starved-air incineration systems since the technology was first introduced and marketed, and now these systems are considered the proven technology standard

  19. Air Pollution and Stroke

    Science.gov (United States)

    Lee, Kuan Ken; Miller, Mark R.; Shah, Anoop S. V.

    2018-01-01

    The adverse health effects of air pollution have long been recognised; however, there is less awareness that the majority of the morbidity and mortality caused by air pollution is due to its effects on the cardiovascular system. Evidence from epidemiological studies have demonstrated a strong association between air pollution and cardiovascular diseases including stroke. Although the relative risk is small at an individual level, the ubiquitous nature of exposure to air pollution means that the absolute risk at a population level is on a par with “traditional” risk factors for cardiovascular disease. Of particular concern are findings that the strength of this association is stronger in low and middle income countries where air pollution is projected to rise as a result of rapid industrialisation. The underlying biological mechanisms through which air pollutants exert their effect on the vasculature are still an area of intense discussion. A greater understanding of the effect size and mechanisms is necessary to develop effective strategies at individual and policy levels to mitigate the adverse cardiovascular effects of air pollution. PMID:29402072

  20. Air Pollution and Stroke.

    Science.gov (United States)

    Lee, Kuan Ken; Miller, Mark R; Shah, Anoop S V

    2018-01-01

    The adverse health effects of air pollution have long been recognised; however, there is less awareness that the majority of the morbidity and mortality caused by air pollution is due to its effects on the cardiovascular system. Evidence from epidemiological studies have demonstrated a strong association between air pollution and cardiovascular diseases including stroke. Although the relative risk is small at an individual level, the ubiquitous nature of exposure to air pollution means that the absolute risk at a population level is on a par with "traditional" risk factors for cardiovascular disease. Of particular concern are findings that the strength of this association is stronger in low and middle income countries where air pollution is projected to rise as a result of rapid industrialisation. The underlying biological mechanisms through which air pollutants exert their effect on the vasculature are still an area of intense discussion. A greater understanding of the effect size and mechanisms is necessary to develop effective strategies at individual and policy levels to mitigate the adverse cardiovascular effects of air pollution.

  1. Air Quality Management Process Cycle

    Science.gov (United States)

    Air quality management are activities a regulatory authority undertakes to protect human health and the environment from the harmful effects of air pollution. The process of managing air quality can be illustrated as a cycle of inter-related elements.

  2. Emission Facilities - Air Emission Plants

    Data.gov (United States)

    NSGIC Education | GIS Inventory — Represents the Primary Facility type Air Emission Plant (AEP) point features. Air Emissions Plant is a DEP primary facility type related to the Air Quality Program....

  3. Lean in Air Permitting Guide

    Science.gov (United States)

    The Lean in Air Permitting Guide is designed to help air program managers at public agencies better understand the potential value and results that can be achieved by applying Lean improvement methods to air permitting processes.

  4. Ambient Air Quality Data Inventory

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Office of Air and Radiation's (OAR) Ambient Air Quality Data (Current) contains ambient air pollution data collected by EPA, other federal agencies, as well as...

  5. Agriculture: Agriculture and Air Quality

    Science.gov (United States)

    Information on air emissions from agricultural practices, types of agricultural burning, air programs that may apply to agriculture, reporting requirements, and links to state and other federal air-quality information.

  6. Air Quality Guide for Ozone

    Science.gov (United States)

    GO! Local Air Quality Conditions Zip Code: State : My Current Location Air Quality Guide for Ozone Ground-level ozone is one of our nation’s most common air pollutants. Use the chart below to help reduce ...

  7. Air Cleaning Technologies

    Science.gov (United States)

    2005-01-01

    Executive Summary Objective This health technology policy assessment will answer the following questions: When should in-room air cleaners be used? How effective are in-room air cleaners? Are in-room air cleaners that use combined HEPA and UVGI air cleaning technology more effective than those that use HEPA filtration alone? What is the Plasmacluster ion air purifier in the pandemic influenza preparation plan? The experience of severe acute respiratory syndrome (SARS) locally, nationally, and internationally underscored the importance of administrative, environmental, and personal protective infection control measures in health care facilities. In the aftermath of the SARS crisis, there was a need for a clearer understanding of Ontario’s capacity to manage suspected or confirmed cases of airborne infectious diseases. In so doing, the Walker Commission thought that more attention should be paid to the potential use of new technologies such as in-room air cleaning units. It recommended that the Medical Advisory Secretariat of the Ontario Ministry of Health and Long-Term Care evaluate the appropriate use and effectiveness of such new technologies. Accordingly, the Ontario Health Technology Advisory Committee asked the Medical Advisory Secretariat to review the literature on the effectiveness and utility of in-room air cleaners that use high-efficiency particle air (HEPA) filters and ultraviolet germicidal irradiation (UVGI) air cleaning technology. Additionally, the Ontario Health Technology Advisory Committee prioritized a request from the ministry’s Emergency Management Unit to investigate the possible role of the Plasmacluster ion air purifier manufactured by Sharp Electronics Corporation, in the pandemic influenza preparation plan. Clinical Need Airborne transmission of infectious diseases depends in part on the concentration of breathable infectious pathogens (germs) in room air. Infection control is achieved by a combination of administrative, engineering

  8. Ventilating Air-Conditioner

    Science.gov (United States)

    Dinh, Khanh

    1994-01-01

    Air-conditioner provides ventilation designed to be used alone or incorporated into cooling or heating system operates efficiently only by recirculating stale air within building. Energy needed to operate overall ventilating cooling or heating system slightly greater than operating nonventilating cooling or heating system. Helps to preserve energy efficiency while satisfying need for increased forced ventilation to prevent accumulation of undesired gases like radon and formaldehyde. Provides fresh treated air to variety of confined spaces: hospital surgeries, laboratories, clean rooms, and printing shops and other places where solvents used. In mobile homes and portable classrooms, eliminates irritant chemicals exuded by carpets, panels, and other materials, ensuring healthy indoor environment for occupants.

  9. Olefin metathesis in air

    Directory of Open Access Journals (Sweden)

    Lorenzo Piola

    2015-10-01

    Full Text Available Since the discovery and now widespread use of olefin metathesis, the evolution of metathesis catalysts towards air stability has become an area of significant interest. In this fascinating area of study, beginning with early systems making use of high oxidation state early transition metal centers that required strict exclusion of water and air, advances have been made to render catalysts more stable and yet more functional group tolerant. This review summarizes the major developments concerning catalytic systems directed towards water and air tolerance.

  10. Air Quality Monitoring Programme

    DEFF Research Database (Denmark)

    Kemp, K.; Palmgren, F.

    The air quality in Danish cities has been monitored continuously since 1982 within the Danish Air Quality (LMP) network. The aim has been to follow the concentration levels of toxic pollutants in the urban atmosphere and to provide the necessary knowledge to assess the trends, to perform source...... apportionment, and to evaluate the chemical reactions and the dispersion of the pollutants in the atmosphere. In 2002 the air quality was measured in four Danish cities and at two background sites. NO2 and PM10 were at several stations found in concentrations above the new EU limit values, which the Member...

  11. Clean Air and Water

    Centers for Disease Control (CDC) Podcasts

    2007-04-10

    The air we breathe and the water we drink are both vital components of our health. Nevertheless, bacteria, pollutants, and other contaminates can alter life-giving air and water into health-threatening hazards. Learn about how scientists at the Centers for Disease Control and Prevention work to protect the public from air and water-related health risks.  Created: 4/10/2007 by CDC National Center for Environmental Health.   Date Released: 4/13/2007.

  12. Air/Water Purification

    Science.gov (United States)

    1992-01-01

    After 18 years of research into air/water pollution at Stennis Space Center, Dr. B. C. Wolverton formed his own company, Wolverton Environmental Services, Inc., to provide technology and consultation in air and water treatment. Common houseplants are used to absorb potentially harmful materials from bathrooms and kitchens. The plants are fertilized, air is purified, and wastewater is converted to clean water. More than 100 U.S. communities have adopted Wolverton's earlier water hyacinth and artificial marsh applications. Catfish farmers are currently evaluating the artificial marsh technology as a purification system.

  13. Air/liquid collectors

    DEFF Research Database (Denmark)

    Jensen, Søren Østergaard; Olesen, Ole; Kristiansen, Finn Harken

    1997-01-01

    this kind of collectors. The modified simulation program has been used for the determination of the surplus in performance which solar heating systems with this type of solar collectors for combined preheating of ventilation air and domestic hot water will have. The simulation program and the efficiency......This report determine efficiency equations for combined air/liquid solar collectors by measurements on to different air/liquid collectors. Equations which contain all relevant informations on the solar collectors. A simulation program (Kviksol) has been modified in order to be able to handle...... equation will allow the manufactures to optimize this kind of systems....

  14. PERAN AIR DALAM PENYEBARAN PENYAKIT

    Directory of Open Access Journals (Sweden)

    Dwi Priyanto

    2012-10-01

    Full Text Available Air merupakan komponen penting dalam kehidupan, semua jenis makhluk hidup memerlukan air untuk kelangsungan hidupnya. Untuk kepentingan manusia, air tidak saja digunakan untuk minum, masak dan cuci, tetapi juga untuk keperluan agrikultur, industri, transportasi, perikanan dan pembuangan limbah cair domestik dan industri. Dalam bidang kesehatan, beberapa  jenis penyakit melibatkan media air dalam proses penyebarannya, baik secara langsung maupun tidak langsung. Penyebaran penyakit secara tidak langsung oleh air disebabkan oleh kandungan bahan kimia terlarut dalam badan air yang bersifat toxic bagi tubuh manusia. Adanya bahan-bahan ini dalam air disebabkan aktifitas industri, pertanian maupun limbah domestik rumah tangga yang dibuang dan mencemari air.

  15. Air-Inflated Fabric Structures

    National Research Council Canada - National Science Library

    Cavallaro, Paul V; Sadegh, Ali M

    2006-01-01

    .... Examples include air ships, weather balloons, inflatable antennas and radomes, temporary shelters, pneumatic muscles and actuators, inflatable boats, temporary bridging, and energy absorbers such as automotive air bags...

  16. Atmospheric Ionizing Radiation (AIR) ER-2 Preflight Analysis

    Science.gov (United States)

    Tai, Hsiang; Wilson, John W.; Maiden, D. L.

    1998-01-01

    Atmospheric ionizing radiation (AIR) produces chemically active radicals in biological tissues that alter the cell function or result in cell death. The AIR ER-2 flight measurements will enable scientists to study the radiation risk associated with the high-altitude operation of a commercial supersonic transport. The ER-2 radiation measurement flights will follow predetermined, carefully chosen courses to provide an appropriate database matrix which will enable the evaluation of predictive modeling techniques. Explicit scientific results such as dose rate, dose equivalent rate, magnetic cutoff, neutron flux, and air ionization rate associated with those flights are predicted by using the AIR model. Through these flight experiments, we will further increase our knowledge and understanding of the AIR environment and our ability to assess the risk from the associated hazard.

  17. Hanscom Air Force Base

    Data.gov (United States)

    Federal Laboratory Consortium — MIT Lincoln Laboratory occupies 75 acres (20 acres of which are MIT property) on the eastern perimeter of Hanscom Air Force Base, which is at the nexus of Lexington,...

  18. Investigating Air Pollution

    Science.gov (United States)

    Carter, Edward J.

    1977-01-01

    Describes an experiment using live plants and cigarette smoke to demonstrate the effects of air pollution on a living organism. Procedures include growth of the test plants in glass bottles, and construction and operation of smoking machine. (CS)

  19. Radioactive air sampling methods

    CERN Document Server

    Maiello, Mark L

    2010-01-01

    Although the field of radioactive air sampling has matured and evolved over decades, it has lacked a single resource that assimilates technical and background information on its many facets. Edited by experts and with contributions from top practitioners and researchers, Radioactive Air Sampling Methods provides authoritative guidance on measuring airborne radioactivity from industrial, research, and nuclear power operations, as well as naturally occuring radioactivity in the environment. Designed for industrial hygienists, air quality experts, and heath physicists, the book delves into the applied research advancing and transforming practice with improvements to measurement equipment, human dose modeling of inhaled radioactivity, and radiation safety regulations. To present a wide picture of the field, it covers the international and national standards that guide the quality of air sampling measurements and equipment. It discusses emergency response issues, including radioactive fallout and the assets used ...

  20. Criteria Air Emissions Trends

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Air Emissions Trends site provides national trends of criteria pollutant and precursor emissions data based on the the National Emissions Inventory (NEI) from...

  1. Calidad del aire interior

    Science.gov (United States)

    This web site will educate the public about indoor environmental issues including health risks and means by which human exposures can be reduced. Content on this site will be focused on Spanish translated resources for information about indoor air quality.

  2. Indoor air pollution

    International Nuclear Information System (INIS)

    Spengler, J.D.

    1985-01-01

    Although official efforts to control air pollution have traditionally focused on outdoor air, it is now apparent that elevated contaminant concentrations are common inside some private and public buildings. Concerns about potential public health problems due to indoor air pollution are based on evidence that urban residents typically spend more than 90 percent of their time indoors, concentrations of some contaminants are higher indoors than outdoors, and for some pollutants personal exposures are not characterized adequately by outdoor measurements. Among the more important indoor contaminants associated with health or irritation effects are passive tobacco smoke, radon decay products, carbon monoxide, nitrogen dioxide, formaldehyde, asbestos fibers, microorganisms and aeroallergens. Efforts to assess health risks associated with indoor air pollution are limited by insufficient information about the number of people exposed, the pattern and severity of exposures, and the health consequences of exposures. An overall strategy should be developed to investigate indoor exposures, health effects, control options, and public policy alternatives

  3. Regional Air Quality Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — This asset provides data on regional air quality, including trace level SO2, nitric acid, ozone, carbon monoxide, and NOy; and particulate sulfate, nitrate, and...

  4. Indoor air quality

    International Nuclear Information System (INIS)

    Hollowell, C.D.

    1981-06-01

    Rising energy prices, among other factors, have generated an incentive to reduce ventilation rates and thereby reduce the cost of heating and cooling buildings. Reduced ventilation in buildings may significantly increase exposure to indoor air pollution and perhaps have adverse effects on occupant health and comfort. Preliminary findings suggest that reduced ventilation may adversely affect indoor air quality unless appropriate control strategies are undertaken. The strategies used to control indoor air pollution depend on the specific pollutant or class of pollutants encountered, and differ somewhat depending on whether the application is to an existing building or a new building under design and construction. Whenever possible, the first course of action is prevention or reduction of pollutant emissions at the source. In most buildings, control measures involve a combination of prevention, removal, and suppression. Common sources of indoor air pollution in buildings, the specific pollutants emitted by each source, the potential health effects, and possible control techniques are discussed

  5. Air void clustering.

    Science.gov (United States)

    2015-06-01

    Air void clustering around coarse aggregate in concrete has been identified as a potential source of : low strengths in concrete mixes by several Departments of Transportation around the country. Research was : carried out to (1) develop a quantitati...

  6. Air Data Calibration Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This facility is for low altitude subsonic altimeter system calibrations of air vehicles. Mission is a direct support of the AFFTC mission. Postflight data merge is...

  7. Diskursus Bahan Bakar Air

    OpenAIRE

    Hidayatulloh, Poempida

    2015-01-01

    Kebutuhan akan energi bagi manusia adalah suatu keniscayaan. Oleh karena itu pencarian manusia dalam menemukan suatu energi yang berkelanjutan (sustainable) adalah suatu proses alamiah yang terjadi secara terus-menerus. Keterbatasan manusia dalam mendapatkan energi selalu berkutat pada paradigma keberadaan hukum kekekalan energi yang menjadi basis pemikiran fisika klasik. Air adalah suatu senyawa yang senantiasa ada di sekitar kita dan tersedia dalam berbagai wujud. Senyawa Air (H2O) terdiri ...

  8. Indoor Air Pollution

    OpenAIRE

    Smith, Kirk R.

    2003-01-01

    Outdoor air pollution in developing-country cities is difficult to overlook. Indoor air pollution caused by burning such traditional fuels as wood, crop residues, and dung is less evident, yet it is responsible for a significant part of country and global disease burdens. The main groups affected are poor women and children in rural areas and urban slums as they go about their daily activi...

  9. Olefin metathesis in air

    OpenAIRE

    Lorenzo Piola; Fady Nahra; Steven P. Nolan

    2015-01-01

    Summary Since the discovery and now widespread use of olefin metathesis, the evolution of metathesis catalysts towards air stability has become an area of significant interest. In this fascinating area of study, beginning with early systems making use of high oxidation state early transition metal centers that required strict exclusion of water and air, advances have been made to render catalysts more stable and yet more functional group tolerant. This review summarizes the major developments...

  10. Air Distribution in Rooms

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    The research on air distribution in rooms is often done as full-size investigations, scale-model investigations or by Computational Fluid Dynamics (CFD). New activities have taken place within all three areas and this paper draws comparisons between the different methods. The outcome of the l......EA sponsored research "Air Flow Pattern within Buildings" is used for comparisons in some parts of the paper because various types of experiments and many countries are involved....

  11. Air Force Leadership Diversity

    Science.gov (United States)

    2017-04-06

    College, Air University, Maxwell AFB, AL. He grew up as part of an Air Force family, entered active duty in 1996, and is a career Aircraft Maintenance... artificially limit them to capping out at O-6 if we want to encourage diversity in our most senior leadership levels as we seek to create a stronger...but I am not sure it does. I find it interesting that as of 31 December 2016 the Deputy Chief of Staff for Intelligence , Surveillance and

  12. Multipollutant air quality management.

    Science.gov (United States)

    Hidy, George M; Pennell, William T

    2010-06-01

    On the basis of a recent NARSTO assessment, this review discusses the factors involved in the implementation of a risk- and results-based multipollutant air quality management strategy applicable to North America. Such a strategy could evolve from current single-pollutant regulatory practices using a series of steps that would seek to minimize risk of exposure for humans and ecosystems while providing for a quantitative evaluation of the effectiveness of the management process. The tools needed to support multipollutant air quality management are summarized. They include application of a formal risk analysis, accounting for atmospheric processes, ambient measurements, emissions characterization, air quality modeling of emissions to ambient concentrations, and characterization of human and ecological responses to ambient pollutant exposure. The new management strategy would expand the current practice of accountability that relates emission reductions and attainment of air quality derived from air quality criteria and standards. Conceptually, achievement of accountability would establish goals optimizing risk reduction associated with pollution management. This expanded approach takes into account the sequence of processes from emissions reduction to resulting changes in ambient concentration. Using ambient concentration as a proxy for exposure, the resulting improvement in human and ecosystem health is estimated. The degree to which this chain of processes and effects can be achieved in current practice is examined in a multipollutant context exemplified by oxidants, as indicated by ozone, particulate matter, and some hazardous air pollutants. Achievement of a multipollutant management strategy will mostly depend on improving knowledge about human and ecosystem response to pollutant exposure.

  13. Canada's Clean Air Act

    International Nuclear Information System (INIS)

    2006-01-01

    This paper provided an outline of Canada's Clean Air Act and examined some of the regulatory changes that will occur as a result of its implementation. The Act is being introduced to strengthen the legislative basis for taking action on reducing air pollution and GHGs, and will allow the government to regulate both indoor and outdoor air pollutants and GHGs. The Act will require the Ministers of the Environment and Health to establish national air quality objectives, as well as to monitor and report on their attainment. The Canadian Environmental Protection Act will be amended to enable the government to regulate the blending of fuels and their components. The Motor Vehicle Fuel Consumption Standards Act will also be amended to enhance the government's authority to regulate vehicle fuel efficiency. The Energy Efficiency Act will also be expanded to allow the government to set energy efficiency standards and labelling requirements for a wider range of consumer and commercial products. The Act will commit to short, medium and long-term industrial air pollution targets. Regulations will be proposed for emissions from industry; on-road and off-road vehicles and engines; and consumer and commercial products. It was concluded that the Government of Canada will continue to consult with provinces, territories, industries and Canadians to set and reach targets for the reduction of both indoor and outdoor air pollutants and GHG emissions. 6 figs

  14. Effect of La0.6 Sr0.4 Co0.2 Fe0.8O3 - δ air electrode-electrolyte interface on the short-term stability under high-current electrolysis in solid oxide electrolyzer cells

    Science.gov (United States)

    Pan, Zehua; Liu, Qinglin; Lyu, Renzhi; Li, Ping; Chan, Siew Hwa

    2018-02-01

    In this work, the effects of the La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) electrode-yttria stabilized zirconia (YSZ) electrolyte interface on the stability of LSCF electrodes under high-current electrolysis are studied. Six different half-cells with different configurations are tested at 800 °C for 264 h under an electrolysis current of 1 A cm-2. A few concluding remarks can be drawn by comparing the behaviors of different cells. Firstly, it is confirmed that the formation of SrZrO3 at the interface will lead to the delamination of air electrode. Thus, the formation of SrZrO3 should be strictly prevented. Secondly, increasing sintering temperature can decrease the degradation rate of polarization resistance, RP, for LSCF electrodes. Thirdly, the increase of ohmic resistance, RS, comes from structural changes as the degradation rate in percentage is similar for cells with different electrolytes and electrodes. Fourthly, the LSCF electrode after the electrolysis test shows recrystallization and lattice shrink which could be the reason for the degradation of LSCF electrodes on Gd0.1Ce0.9O2-δ (GDC) electrolytes. Lastly, comparing all the samples, the cell composed of YSZ electrolyte, dense GDC interlayer and LSCF electrode sintered at 1000 °C can be used for future study on the degradation mechanisms of the LSCF air electrode and the electrolyte.

  15. Automatic air flow control in air conditioning ducts

    Science.gov (United States)

    Obler, H. D.

    1972-01-01

    Device is designed which automatically selects air flow coming from either of two directions and which can be adjusted to desired air volume on either side. Device uses one movable and two fixed scoops which control air flow and air volume.

  16. The urban air; L'air de la ville

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    This paper presents the abstracts of conferences proposed during the meeting on the urban air, organized by the French Meteorological Society in november 2002. These conferences dealt with the air quality monitoring, the public health impacts, the air pollution in function of the meteorological effects, the pollutants, the main factors of the air quality and the models of the meteorology. (A.L.B.)

  17. Control of the Air: The Primary Air Power Role

    Science.gov (United States)

    2011-12-01

    air, p 8-9. 23. R Cargill Hall. Case Studies in Strategic Bombardment, Air Force History and Museums Program, 1998, “British Strategic Air...Relations with Special Reference to Kashmir. Atlantic Publishers. New Delhi. 2003. Hall, R. Cargill . Case Studies in Strategic Bombardment. Air

  18. 40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Air conditioning environmental test... conditioning environmental test facility ambient requirements. The goal of an air conditioning test facility is... elements that are discussed are ambient air temperature and humidity, minimum test cell size, solar heating...

  19. Evaluation of reciprocating electromagnetic air pumping for portable PEMFC

    International Nuclear Information System (INIS)

    Kwon, Kilsung; Kang, Ho; Kang, Seongwon; Kim, Daejoong

    2013-01-01

    In this paper, we present a proton exchange membrane fuel cell (PEMFC) integrated with an electromagnetic (EM) air pump. The EM air pump provides the PEMFC with air by reciprocating motions of the permanent magnet attached to a flexible membrane. We performed a parametric study to decide the optimal dimensions of the reciprocating EM air pump. The effects of various operating parameters on the EM air pump were investigated with the root-mean-square (RMS) flow rate and current. A core with a higher relative permeability shows better performance. The RMS current linearly increases with the applied voltage and shows no dependence on the frequency. The RMS flow rate also increases with the voltage. The RMS flow rate per power consumption is highest at the frequency around 20 Hz and decreases as the applied voltage increases. When the reciprocating EM air pump was used to supply air to the portable PEMFC, it was found that the power density of the PEMFC increases with the applied voltage and shows the highest performance at the frequency of 10 Hz. We compared the performance of the PEMFC between the flow meter and the EM air pump used as an air supplier. About 81% of the output power using the flow meter was obtained when the EM air pump is operated at the applied voltage of 5 V. The parasitic power ratio reaches at its minimum value about 0.1 with an EM applied voltage of 0.25V. (paper)

  20. The Role of AIRE in the Immunity Against Candida Albicans in a Model of Human Macrophages

    Directory of Open Access Journals (Sweden)

    Jose Antonio Tavares de Albuquerque

    2018-03-01

    Full Text Available Autoimmune-polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED is a primary immunodeficiency caused by mutations in the autoimmune regulator gene (AIRE. Patients with AIRE mutations are susceptible to Candida albicans infection and present with autoimmune disorders. We previously demonstrated that cytoplasmic AIRE regulates the Syk-dependent Dectin-1 pathway. In this study, we further evaluated direct contact with fungal elements, synapse formation, and the response of macrophage-like THP-1 cells to C. albicans hyphae to determine the role of AIRE upon Dectin receptors function and signaling. We examined the fungal synapse (FS formation in wild-type and AIRE-knockdown THP-1 cells differentiated to macrophages, as well as monocyte-derived macrophages from APECED patients. We evaluated Dectin-2 receptor signaling, phagocytosis, and cytokine secretion upon hyphal stimulation. AIRE co-localized with Dectin-2 and Syk at the FS upon hyphal stimulation of macrophage-like THP-1 cells. AIRE-knockdown macrophage-like THP-1 cells exhibited less Dectin-1 and Dectin-2 receptors accumulation, decreased signaling pathway activity at the FS, lower C. albicans phagocytosis, and less lysosome formation. Furthermore, IL-1β, IL-6, or TNF-α secretion by AIRE-knockdown macrophage-like THP-1 cells and AIRE-deficient patient macrophages was decreased compared to control cells. Our results suggest that AIRE modulates the FS formation and hyphal recognition and help to orchestrate an effective immune response against C. albicans.