WorldWideScience

Sample records for hfb2 anf hfc

  1. Densification and properties of HfB2 based materials

    International Nuclear Information System (INIS)

    Sonber, J.K.; Ch Murthy, T.S.R.; Bedse, R.D.; Subramanian, C.; Kumar, Sunil; Fotedar, R.K.; Krishnamurthy, N.; Suri, A.K.

    2011-01-01

    This paper presents the results of investigation carried out on densification and properties of HfB 2 based materials. Densification study of HfB 2 with and without sinter additive was carried out by hot pressing. TiSi 2 and CrSi 2 were used as sinter additive. Monolithic HfB 2 was densified to only 80%ρ th at 1850 deg C with a pressure of 35 MPa. Addition of 10 wt% TiSi 2 resulted in a density of 95% TD at a relatively low temperature of 1650 deg C and a low pressure of 20 MPa. Addition of 10% CrSi 2 resulted in a density of 99% TD at the same operating conditions. All the samples were characterized by SEM/EDS and mechanical property measurement. (author)

  2. Behavior of HfB2-SiC Materials in Simulated Re-Entry Environments

    Science.gov (United States)

    Ellerby, Don; Beckman, Sarah; Irby, Edward; Johnson, Sylvia M.; Gunsman, Michael; Gasch, Matthew; Ridge, Jerry; Martinez, Ed; Squire, Tom; Olejniczak, Joe

    2003-01-01

    The objectives of this research are to: 1) Investigate the oxidation/ablation behavior of HfB2/SiC materials in simulated re-entry environments; 2) Use the arc jet test results to define appropriate use environments for these materials for use in vehicle design. The parameters to be investigated include: surface temperature, stagnation pressure, duration, number of cycles, and thermal stresses.

  3. Lattice Thermal Conductivity from Atomistic Simulations: ZrB2 and HfB2

    Science.gov (United States)

    Lawson, John W.; Daw, Murray S.; Bauschlicher, Charles W.

    2012-01-01

    Ultra high temperature ceramics (UHTC) including ZrB2 and HfB2 have a number of properties that make them attractive for applications in extreme environments. One such property is their high thermal conductivity. Computational modeling of these materials will facilitate understanding of fundamental mechanisms, elucidate structure-property relationships, and ultimately accelerate the materials design cycle. Progress in computational modeling of UHTCs however has been limited in part due to the absence of suitable interatomic potentials. Recently, we developed Tersoff style parameterizations of such potentials for both ZrB2 and HfB2 appropriate for atomistic simulations. As an application, Green-Kubo molecular dynamics simulations were performed to evaluate the lattice thermal conductivity for single crystals of ZrB2 and HfB2. The atomic mass difference in these binary compounds leads to oscillations in the time correlation function of the heat current, in contrast to the more typical monotonic decay seen in monoatomic materials such as Silicon, for example. Results at room temperature and at elevated temperatures will be reported.

  4. Oxidation Behavior of HfB2-SiC Materials in Dissociated Environments

    Science.gov (United States)

    Ellerby, Don; Irby, Edward; Johnson, Sylvia M.; Beckman, Sarah; Gusman, Michael; Gasch, Matthew

    2002-01-01

    Hafnium diboride based materials have shown promise for use in extremely high temperature applications, such as sharp leading edges on future reentry vehicles. During reentry, the oxygen and nitrogen in the atmosphere are dissociated by the shock layer ahead of the sharp leading edge such that surface reactions are determined by reactions of monatomic oxygen and nitrogen rather than O2, and N2. Simulation of the reentry environment on the ground requires the use of arc jet (plasma jet) facilities that provide monatomic species and are the closest approximation to actual flight conditions. Simple static or flowing oxidation studies under ambient pressures and atmospheres are not adequate to develop an understanding of a materials behavior in flight. Arc jet testing is required to provide the appropriate stagnation pressures, heat fluxes, enthalpies, heat loads and atmospheres encountered during flight. This work looks at the response of HfB2/SiC materials exposed to various simulated reentry environments.

  5. Lattice Thermal Conductivity of Ultra High Temperature Ceramics ZrB2 and HfB2 from Atomistic Simulations

    Science.gov (United States)

    Lawson, John W.; Murray, Daw S.; Bauschlicher, Charles W., Jr.

    2011-01-01

    Atomistic Green-Kubo simulations are performed to evaluate the lattice thermal conductivity for single crystals of the ultra high temperature ceramics ZrB2 and HfB2 for a range of temperatures. Recently developed interatomic potentials are used for these simulations. Heat current correlation functions show rapid oscillations which can be identified with mixed metal-Boron optical phonon modes. Agreement with available experimental data is good.

  6. Role of WC additive on reaction, solid-solution and densification in HfB2–SiC ceramics

    DEFF Research Database (Denmark)

    Hu, Dong-Li; Zheng, Qiang; Gu, Hui

    2014-01-01

    A comparative study of phase components and compositions was performed for the pressureless sintered HfB2–SiC–WC composites by various analytical methods. The relative decrease of HfB2 phase leads to a new reaction of HfO2 removal by WC to create B2O3. By using SiC instead of Si3N4 as milling med...

  7. Phase and Microstructural Correlation of Spark Plasma Sintered HfB2-ZrB2 Based Ultra-High Temperature Ceramic Composites

    Directory of Open Access Journals (Sweden)

    Ambreen Nisar

    2017-07-01

    Full Text Available The refractory diborides (HfB2 and ZrB2 are considered as promising ultra-high temperature ceramic (UHTCs where low damage tolerance limits their application for the thermal protection system in re-entry vehicles. In this regard, SiC and CNT have been synergistically added as the sintering aids and toughening agents in the spark plasma sintered (SPS HfB2-ZrB2 system. Herein, a novel equimolar composition of HfB2 and ZrB2 has shown to form a solid-solution which then allows compositional tailoring of mechanical properties (such as hardness, elastic modulus, and fracture toughness. The hardness of the processed composite is higher than the individual phase hardness up to 1.5 times, insinuating the synergy of SiC and CNT reinforcement in HfB2-ZrB2 composites. The enhanced fracture toughness of CNT reinforced composite (up to a 196% increment surpassing that of the parent materials (ZrB2/HfB2-SiC is attributed to the synergy of solid solution formation and enhanced densification (~99.5%. In addition, the reduction in the analytically quantified interfacial residual tensile stress with SiC and CNT reinforcements contribute to the enhancement in the fracture toughness of HfB2-ZrB2-SiC-CNT composites, mandatory for aerospace applications.

  8. Effects of HfB2 and HfN Additions on the Microstructures and Mechanical Properties of TiB2-Based Ceramic Tool Materials

    Science.gov (United States)

    An, Jing; Song, Jinpeng; Liang, Guoxing; Gao, Jiaojiao; Xie, Juncai; Cao, Lei; Wang, Shiying; Lv, Ming

    2017-01-01

    The effects of HfB2 and HfN additions on the microstructures and mechanical properties of TiB2-based ceramic tool materials were investigated. The results showed that the HfB2 additive not only can inhibit the TiB2 grain growth but can also change the morphology of some TiB2 grains from bigger polygons to smaller polygons or longer ovals that are advantageous for forming a relatively fine microstructure, and that the HfN additive had a tendency toward agglomeration. The improvement of flexural strength and Vickers hardness of the TiB2-HfB2 ceramics was due to the relatively fine microstructure; the decrease of fracture toughness was ascribed to the formation of a weaker grain boundary strength due to the brittle rim phase and the poor wettability between HfB2 and Ni. The decrease of the flexural strength and Vickers hardness of the TiB2-HfN ceramics was due to the increase of defects such as TiB2 coarse grains and HfN agglomeration; the enhancement of fracture toughness was mainly attributed to the decrease of the pore number and the increase of the rim phase and TiB2 coarse grains. The toughening mechanisms of TiB2-HfB2 ceramics mainly included crack bridging and transgranular fracture, while the toughening mechanisms of TiB2-HfN ceramics mainly included crack deflection, crack bridging, transgranular fracture, and the core-rim structure. PMID:28772821

  9. Effects of HfB2 and HfN Additions on the Microstructures and Mechanical Properties of TiB2-Based Ceramic Tool Materials

    Directory of Open Access Journals (Sweden)

    Jing An

    2017-04-01

    Full Text Available The effects of HfB2 and HfN additions on the microstructures and mechanical properties of TiB2-based ceramic tool materials were investigated. The results showed that the HfB2 additive not only can inhibit the TiB2 grain growth but can also change the morphology of some TiB2 grains from bigger polygons to smaller polygons or longer ovals that are advantageous for forming a relatively fine microstructure, and that the HfN additive had a tendency toward agglomeration. The improvement of flexural strength and Vickers hardness of the TiB2-HfB2 ceramics was due to the relatively fine microstructure; the decrease of fracture toughness was ascribed to the formation of a weaker grain boundary strength due to the brittle rim phase and the poor wettability between HfB2 and Ni. The decrease of the flexural strength and Vickers hardness of the TiB2-HfN ceramics was due to the increase of defects such as TiB2 coarse grains and HfN agglomeration; the enhancement of fracture toughness was mainly attributed to the decrease of the pore number and the increase of the rim phase and TiB2 coarse grains. The toughening mechanisms of TiB2-HfB2 ceramics mainly included crack bridging and transgranular fracture, while the toughening mechanisms of TiB2-HfN ceramics mainly included crack deflection, crack bridging, transgranular fracture, and the core-rim structure.

  10. Lattice Thermal Conductivity of Ultra High Temperature Ceramics (UHTC) ZrB2 and HfB2 from Atomistic Simulations

    Science.gov (United States)

    Lawson, John W.; Daw, Murray S.; Bauschlicher, Charles W.

    2012-01-01

    Ultra high temperature ceramics (UHTC) including ZrB2 and HfB2 have a number of properties that make them attractive for applications in extreme environments. One such property is their high thermal conductivity. Computational modeling of these materials will facilitate understanding of fundamental mechanisms, elucidate structure-property relationships, and ultimately accelerate the materials design cycle. Progress in computational modeling of UHTCs however has been limited in part due to the absence of suitable interatomic potentials. Recently, we developed Tersoff style parameterizations of such potentials for both ZrB2 and HfB2 appropriate for atomistic simulations. As an application, Green-Kubo molecular dynamics simulations were performed to evaluate the lattice thermal conductivity for single crystals of ZrB2 and HfB2. The atomic mass difference in these binary compounds leads to oscillations in the time correlation function of the heat current, in contrast to the more typical monotonic decay seen in monoatomic materials such as Silicon, for example. Results at room temperature and at elevated temperatures will be reported.

  11. Global emissions of the hydrofluorocarbons (HFCs) HFC-365mfc, HFC-245fa, HFC-227ea, and HFC-236fa based on atmospheric observations

    Science.gov (United States)

    Vollmer, M. K.; Miller, B. R.; Rigby, M. L.; Reimann, S.; Muhle, J.; Agage, Soge, Snu Members, Kopri Members

    2010-12-01

    We report on the atmospheric measurements and global emissions of the hydrofluorocarbons (HFCs) HFC-365mfc (CH3CH2CF2CF3, 1,1,1,3,3-pentafluorobutane), HFC-245fa (CHF2CH2CF3, 1,1,1,3,3-pentafluoropropane), HFC-227ea (CF3CHFCF3, 1,1,1,2,3,3,3-heptafluoropropane), and HFC-236fa (CF3CH2CF3, 1,1,1,3,3,3-hexafluoropropane). These measurements are from in-situ observations at stations of AGAGE (Advanced Global Atmospheric Gases Experiment) and SOGE (System for Observations of Halogenated Greenhouse Gases in Europe), and from the Korean station Gosan. We also report on flask sample measurements from the Antarctic stations King Sejong and Troll, and extend our records back to the 1970s using archived air samples of both hemispheres. All data are used in a global 12-box 2-dimensional atmospheric transport model to derive global abundances and emission estimates. All four HFCs have strongly increased in the atmosphere in recent years with growth rates at nearly 10 %, resulting in dry air mole fractions at the end of 2009 of 0.49 ppt for HFC-365mfc, 1.00 ppt for HFC-245fa, and 0.51 ppt for HFC-227ea. HFC-236fa, for which we report the first atmospheric measurements, is less abundant and has grown to 0.069 ppt at the end of 2009. Our model results show rapidly growing emissions of HFC-365mfc and HFC-245fa after 2002 but surprisingly these have now started to decline to globally 2.7 kt/yr (HFC-365mfc) and 6.1 kt/yr (HFC-245fa). On the other hand HFC-227ea and HFC-236fa show uninterrupted growth in their emissions of 2.5 kt/yr and 0.2 kt/yr at the end of 2009.

  12. Atrial natriuretic factor receptor guanylate cyclase, ANF-RGC, transduces two independent signals, ANF and Ca2+

    Directory of Open Access Journals (Sweden)

    Teresa eDuda

    2014-03-01

    Full Text Available Atrial natriuretic factor receptor guanylate cyclase, ANF-RGC, was the first discovered member of the mammalian membrane guanylate cyclase family. The hallmark feature of the family is that a single protein contains both the site for recognition of the regulatory signal and the ability to transduce it into the production of the second messenger, cyclic GMP. For over two decades, the family has been classified into two subfamilies, the hormone receptor subfamily with ANF-RGC being its paramount member, and the Ca2+ modulated subfamily, which includes the rod outer segment guanylate cyclases, ROS-GC1 and 2, and the olfactory neuroepithelial guanylate cyclase, ONE-GC. ANF-RGC is the receptor and the signal transducer of the most hypotensive hormones, atrial natriuretic factor (ANF and B-type natriuretic peptide (BNP. After binding these hormones at the extracellular domain it, at its intracellular domain, signals activation of the C-terminal catalytic module and accelerates the production of cyclic GMP. Cyclic GMP then serves the second messenger role in biological responses of ANF and BNP such as natriuresis, diuresis, vasorelaxation and anti-proliferation. Very recently another modus operandi for ANF-RGC was revealed. Its crux is that ANF-RGC activity is also regulated by Ca2+. The Ca2+ sensor neurocalcin  mediates this signaling mechanism. Strikingly, the Ca2+ and ANF signaling mechanisms employ separate structural motifs of ANF-RGC in modulating its core catalytic domain in accelerating the production of cyclic GMP. In this review the biochemistry and physiology of these mechanisms with emphasis on cardiovascular regulation will be discussed.

  13. ANF and exocrine pancreas: ultrastructural autoradiographic localization in acinar cells

    International Nuclear Information System (INIS)

    Chabot, J.G.; Morel, G.; Belles-Isles, M.; Jeandel, L.; Heisler, S.

    1988-01-01

    Atrial natriuretic factor (ANF) binding sites have been recently demonstrated to be present in exocrine pancreas by an in vitro autoradiographic approach. An autoradiographic study was carried out to identify the exocrine cells containing ANF binding sites and to monitor the fate of 125 I-labeled ANF in acinar cells after removal of pancreas at specific time intervals (1-30 min) after intravenous administration. At the light microscopic level, silver grains were found over acinar and centroacinar cells. Concomitant injection of an excess of unlabeled ANF inhibited the binding of labeled peptide by approximately 60%. At the electron microscopic level, the time-course study in acinar cells has revealed that of the cell compartments examined, plasma membrane, Golgi apparatus, mitochondria, and zymogen granules, the nucleus had distinct labeling patterns. Plasma membrane was maximally labeled 1 and 2 min after injection with 125 I-ANF. Golgi apparatus was significantly labeled from 2 to 30 min after injection, mitochondria from 1 to 30 min after injection, zymogen granules at 1 and 15 min, and the nucleus only at 30 min. The lysosomal compartment was not labeled during the 30-min observation period. These results suggest that after binding to the plasma membrane, ANF is rapidly internalized and distributed to the intracellular organelles as a function of time. Labeling of the zymogen granules suggests that they may bind ANF and that the atrial peptide may be secreted by acinar cells. The significance of association of radioactivity with mitochondria and nuclei remains to be elucidated but may represent intracellular sites of action of ANF complementary to those on plasma membranes

  14. Atmospheric histories and global emissions of the anthropogenic hydrofluorocarbons HFC-365mfc, HFC-245fa, HFC-227ea, and HFC-236fa

    Science.gov (United States)

    Vollmer, Martin K.; Miller, Benjamin R.; Rigby, Matthew; Reimann, Stefan; Mühle, Jens; Krummel, Paul B.; O'Doherty, Simon; Kim, Jooil; Rhee, Tae Siek; Weiss, Ray F.; Fraser, Paul J.; Simmonds, Peter G.; Salameh, Peter K.; Harth, Christina M.; Wang, Ray H. J.; Steele, L. Paul; Young, Dickon; Lunder, Chris R.; Hermansen, Ove; Ivy, Diane; Arnold, Tim; Schmidbauer, Norbert; Kim, Kyung-Ryul; Greally, Brian R.; Hill, Matthias; Leist, Michael; Wenger, Angelina; Prinn, Ronald G.

    2011-04-01

    We report on ground-based atmospheric measurements and emission estimates of the four anthropogenic hydrofluorocarbons (HFCs) HFC-365mfc (CH3CF2CH2CF3, 1,1,1,3,3-pentafluorobutane), HFC-245fa (CHF2CH2CF3, 1,1,1,3,3-pentafluoropropane), HFC-227ea (CF3CHFCF3, 1,1,1,2,3,3,3-heptafluoropropane), and HFC-236fa (CF3CH2CF3, 1,1,1,3,3,3-hexafluoropropane). In situ measurements are from the global monitoring sites of the Advanced Global Atmospheric Gases Experiment (AGAGE), the System for Observations of Halogenated Greenhouse Gases in Europe (SOGE), and Gosan (South Korea). We include the first halocarbon flask sample measurements from the Antarctic research stations King Sejong and Troll. We also present measurements of archived air samples from both hemispheres back to the 1970s. We use a two-dimensional atmospheric transport model to simulate global atmospheric abundances and to estimate global emissions. HFC-365mfc and HFC-245fa first appeared in the atmosphere only ˜1 decade ago; they have grown rapidly to globally averaged dry air mole fractions of 0.53 ppt (in parts per trillion, 10-12) and 1.1 ppt, respectively, by the end of 2010. In contrast, HFC-227ea first appeared in the global atmosphere in the 1980s and has since grown to ˜0.58 ppt. We report the first measurements of HFC-236fa in the atmosphere. This long-lived compound was present in the atmosphere at only 0.074 ppt in 2010. All four substances exhibit yearly growth rates of >8% yr-1 at the end of 2010. We find rapidly increasing emissions for the foam-blowing compounds HFC-365mfc and HFC-245fa starting in ˜2002. After peaking in 2006 (HFC-365mfc: 3.2 kt yr-1, HFC-245fa: 6.5 kt yr-1), emissions began to decline. Our results for these two compounds suggest that recent estimates from long-term projections (to the late 21st century) have strongly overestimated emissions for the early years of the projections (˜2005-2010). Global HFC-227ea and HFC-236fa emissions have grown to average values of 2.4 kt yr-1

  15. Isothermal phase equilibria for the (HFC-32 + HFC-134a) mixed-gas hydrate system

    International Nuclear Information System (INIS)

    Miyauchi, Hiroshi; Yasuda, Kenjiro; Matsumoto, Yuuki; Hashimoto, Shunsuke; Sugahara, Takeshi; Ohgaki, Kazunari

    2012-01-01

    Highlights: ► Structural phase transition results in the heterogeneous azeotropic-like behaviour. ► HFC-134a molecules, in spite of an s-II former, occupy the large cages of s-I. ► Negative azeotropic-like behaviour becomes more remarkable at higher temperatures. - Abstract: Isothermal phase equilibria (pressure-composition relations in hydrate, gas, and aqueous phases) in the {difluoromethane (HFC-32) + 1,1,1,2-tetrafluoroethane (HFC-134a)} mixed-gas hydrate system were measured at the temperatures 274.15 K, 279.15 K, and 283.15 K. The heterogeneous azeotropic-like behaviour derived from the structural phase transition of (HFC-32 + HFC-134a) mixed-gas hydrates appears over the whole temperature range of the present study. In addition to the heterogeneous azeotropic-like behaviour, the isothermal phase equilibrium curves of the (HFC-32 + HFC-134a) mixed-gas hydrate system exhibit the negative homogeneous azeotropic-like behaviour at temperatures 279.15 K and 283.15 K. The negative azeotropic-like behaviour, which becomes more remarkable at higher temperatures, results in the lower equilibrium pressure of (HFC-32 + HFC-134a) mixed-gas hydrates than those of both simple HFC-32 and HFC-134a hydrates. Although the HFC-134a molecule forms the simple structure-II hydrate at the temperatures, the present findings reveal that HFC-134a molecules occupy a part of the large cages of the structure-I mixed-gas hydrate.

  16. THERMODYNAMIC PROPERTIES OF SELECTED HFC REFRIGERANTS

    Science.gov (United States)

    Hydrofluorocarbon (HFC) refrigerants are possible alternatives to replace ozone-depleting chlorofluorocarbon and hydrochlorofluorocarbon (HCFC) refrigerants. The flammability of a proposed new refrigerant is a major consideration in assessing its utility for a particular applicat...

  17. Multiscale Modeling of Ultra High Temperature Ceramics (UHTC) ZrB2 and HfB2: Application to Lattice Thermal Conductivity

    Science.gov (United States)

    Lawson, John W.; Daw, Murray S.; Squire, Thomas H.; Bauschlicher, Charles W.

    2012-01-01

    We are developing a multiscale framework in computational modeling for the ultra high temperature ceramics (UHTC) ZrB2 and HfB2. These materials are characterized by high melting point, good strength, and reasonable oxidation resistance. They are candidate materials for a number of applications in extreme environments including sharp leading edges of hypersonic aircraft. In particular, we used a combination of ab initio methods, atomistic simulations and continuum computations to obtain insights into fundamental properties of these materials. Ab initio methods were used to compute basic structural, mechanical and thermal properties. From these results, a database was constructed to fit a Tersoff style interatomic potential suitable for atomistic simulations. These potentials were used to evaluate the lattice thermal conductivity of single crystals and the thermal resistance of simple grain boundaries. Finite element method (FEM) computations using atomistic results as inputs were performed with meshes constructed on SEM images thereby modeling the realistic microstructure. These continuum computations showed the reduction in thermal conductivity due to the grain boundary network.

  18. Increased ANF secretion after volume expansion is preserved in rats with heart failure

    International Nuclear Information System (INIS)

    Chien, Young Wei; Barbee, R.W.; MacPhee, A.L.; Frohlich, E.D.; Trippodo, N.C.

    1988-01-01

    To examine whether the failing heart has reached a maximal capacity to increase plasma atrial natriuretic factor (ANF) concentration, the change in plasma immunoreactive ANF, measured by radioimmunoassay level due to acute blood volume expansion was determined in conscious rats with chronic heart failure. Varying degrees of myocardial infarction and thus heart failure were induced by coronary artery ligation 3 wk before study. Compared with controls, infarcted rats had decreases in mean arterial pressure cardiac index, renal blood flow, and peak left ventricle-developed pressure after aortic occlusion, and increases in central venous pressure, left ventricular end-diastolic pressure, total peripheral resistance, plasma ANF level. Plasma ANF was correlated with infarct size, cardiac filling pressures, and left ventricle pressure-generating ability. At 5 min after 25% blood volume expansion, plasma ANF in rats with heart failure increased by 2,281 ± 345 pg/ml; the magnitude of the changes in circulating ANF and hemodynamic measurements was similar in controls. The results suggest that plasma ANF level can be used as a reliable index of the severity of heart failure, and that the capacity to increase plasma ANF concentration after acute volume expansion is preserved in rats with heart failure. There was no evidence of a relative deficiency of circulating ANF in this model of heart failure

  19. CFC and HFC recycling equipments: Test performances

    International Nuclear Information System (INIS)

    Picini, P.; Caropreso, G.; Cicoli, G.; Posarelli, M.

    1996-12-01

    Actual regulatory conditions about ozone layer depleting chemicals set problems on their disposal and on the management of plants still using illegal CFCs. Anyway fluids that will replace CFCs (i.e. HFCs) will not be allowed to be spread into the atmosphere, due to their high costs and to the greenhouse effect. A viable solution would be the recovery, purification and recycle of contaminated fluids. ENEA (National Agency for New Technology, Energy and the Environment), in cooperation with ICF (Industria Componenti Frigoriferi) Company leader in the field of air refrigerating and conditioning, patented a device able to extract, to clean and to recycle CFC 12 and HFC 134a in the refrigerating systems. This paper presents experimental data from the qualification tests on a device performing the above mentioned operations regarding systems that use HFC 134a as process fluid

  20. High-aspect-ratio HfC nanobelts accompanied by HfC nanowires: Synthesis, characterization and field emission properties

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Song, E-mail: tiansong22@126.com [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072 (China); School of Materials Science and Engineering, Chongqing Jiaotong University, Chongqing 400074 (China); Zhang, Yulei; Ren, Jincui; Qiang, Xinfa; Zhang, Shouyang [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072 (China); Li, Hejun, E-mail: lihejun@nwpu.edu.cn [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072 (China)

    2017-04-30

    Highlights: • HfC naobelts accompanied by HfC nanowires were synthesized by a catalytic CVD method. • HfC nanobelts as a novel structure of HfC ceramic are reported for the first time. • HfC nanobelts have 100–200 μm in lengths and reach up to 10 μm in widths. • The synthesized product is promising field nanoemitters. - Abstract: As a key refractory carbide, hafnium carbide (HfC) is commonly used as structural materials while the field emission (FE) application of HfC in the field of vacuum microelectronics is almost the only one for functional material purposes. Based on its outstanding physical and chemical characteristics, HfC is identified as a potential candidate with satisfactory mechanical properties and long-term and/or high-temperature FE stability for future applications in high-performance field emitters. However, the development of HfC in various FE applications is hindered because it is not facile to fabricate large-scale low-dimensional HfC field nanoemitters. Herein, High-aspect-ratio HfC nanobelts accompanied by HfC nanowires were synthesized on a large scale by a traditional and simple catalytic chemical vapor deposition (CVD) method. Classical vapor–liquid–solid (VLS) theory was employed to explain the growth of the HfC nanowires and nanobelts along axial direction. The thin HfO{sub 2} shell and thin C layer surrounding the nanostructures might give rise to the diameter fluctuation of HfC nanowires and the width increase of HfC nanobelts in lateral direction. Field emission results show that the high-aspect-ratio HfC nanobelts accompanied by the nanowires are promising field nanoemitters, which exhibit excellent field emission properties with a fairly low turn-on field of ∼1.5 V μm{sup −1} and a low current fluctuation less than ∼10%. This suggests that HfC ceramics with high-aspect-ratio nanostructures are ideal cathode material for various field emission applications.

  1. Comparison of different standards used in radioimmunoassay for atrial natriuretic factor (ANF)

    DEFF Research Database (Denmark)

    Rasmussen, Peter Have; Nielsen, M. Damkjær; Giese, J.

    1991-01-01

    , estimates of the ANF content in human plasma samples with different standard preparations as the reference showed a considerable variability. With the international standard as the gold reference (plasma ANF concentration 100%) the apparent plasma ANF concentrations measured with the other reference......Six different standards for determination of atrial natriuretic factor (ANF) in human plasma samples have been compared using our radio-immunoassay for ANF: International standard 85/669, National Biological Standard Boards, UK; Bachem standard, Torrance, USA; Bachem standard, Bubendorf......, Switzerland; Bissendorf standard, Wedemark, Germany; Peninsula standard, Belmont, USA; UCB-Bioproducts standard, Brussels, Belgium, Standard curves obtained with different preparations were in parallel but showed considerable quantitative differences. Standard curves referring to the Bissendorf standard...

  2. Study on the changes of serum levels of ANF in patients with atrial fibrillation (AF)

    International Nuclear Information System (INIS)

    Xia Xiaojie; Zan Qin; Yang Junfeng; Huang Yuantao; Cao Kejiang; Du Tongxing; Wang Zizheng

    2004-01-01

    Objective: To study the changes of serum levels of ANF in patients with atrial fibrillation and to explore the mechanism of the prethrombotic state induced by AF. Methods: Serum levels of ANF were measured with RIA in 21 patients with isolated paroxysmal atrial fibrillation (IPAF) both during and one week after termination of the attack. Levels were also measured in 28 patients with isolated sustained atrial fibrillation (ISAF), 27 patients with rheumatic mitral stenosis associated with persistent AF (RHD), 32 patients with paroxysmal supraventricular tachycardia (PSVT) and 35 controls. Results: Serum levels of ANF and Hct% readings in: 1) patients with IPAF during attack 2) patients with ISAF and 3) patients with RHD were significantly higher than those in: 1) patients with IPAF one week after termination of the attack 2) patients with PSVT and 3) the controls (p<0.05). Values in patients with PSVT were not much different from those in controls. In patients with IPAF during the attack, serum ANF levels and Hct% readings were positively correlated to the duration of the attack. Serum ANF levels were not related to such parameters as: age, sex, mitral valve area, ejection fraction and inner diameter of left atrium. Conclusion: There is hemoconcentration in patients with atrial fibrillation, which is related to the hypersecretion of ANF in these patients

  3. Transmission design in a multimode HFC network

    Science.gov (United States)

    Cambron, G. Keith

    1996-11-01

    Contemporary hybrid fiber coaxial (HFC) networks are capable of supporting a wide range of services including traditional analog video, telephony, digital video, and data services. Each service has unique performance or service requirements. This contribution examines transmission design for one such network. Pacific Bell's advanced communications network (ACN). The design methodology begins with a set of end to end service quality objectives. Network impairments, such as noise, distortion and delay, are allocated across the network elements using a set of standard network models. These models are a representative set of the actual field designs and bound the network operating parameters. Network components, headend equipment, and customer premises equipment are specified analytically or characterized empirically in relationship to the chosen impairment set. The component parameters are then included in analytical models to estimate overall network performance. In addition to the forward path transmission considerations examined by traditional coaxial network designers, other dimensions including power consumption, traffic demand, and message latency are taken into account. Analytical models are used to estimate the effects of multiple modulation schemes within the unified network. The variability introduced by on demand services such as telephony and interactive digital services changes the base computational domain from deterministic models to stochastic ones. These models are then used to set operating parameters at measurable points throughout the network for proof of performance prior to turn up, and for ongoing performance monitoring. For closure, empirical results are compared with model projections as a way of verifying and improving the predictive models.

  4. Water plasma generation under atmospheric pressure for HFC destruction

    International Nuclear Information System (INIS)

    Watanabe, Takayuki; Tsuru, Taira

    2008-01-01

    The purpose of this paper is to investigate the decomposition process of hydrofluoroethylene (HFC-134a) by water plasmas. The water plasma was generated by DC arc discharge with a cathode of hafnium embedded into a copper rod and a nozzle-type copper anode. The advantage of the water plasma torch is the generation of 100%-water plasma by DC discharge. The distinctive steam generation leads to the portable light-weight plasma generation system that does not require the gas supply unit, as well as the high energy efficiency owing to the nonnecessity of the additional water-cooling. HFC-134a was injected into the water plasma jet to decompose it in the reaction tube. Neutralization vessel was combined to the reaction tube to absorb F 2 and HF generated from the HFC-134a decomposition. The decomposition was performed with changing the feed rate of HFC-134a up to 185 mmol/min. The decomposition efficiency of 99.9% can be obtained up to 0.43 mmol/kJ of the ratio of HFC-134a feed rate to the arc power, hence the maximum feed rate was estimated to be 160 g/h at 1 kW of the arc power

  5. Two-phase flow characteristics of HFC and HCFC fluid

    International Nuclear Information System (INIS)

    Ueno, T.; Matsuda, K.; Kusakabe, T.

    1998-01-01

    Some two-phase flow characteristics of HFC and HCFC fluid have been investigated experimentally. Fluids used in this experiment are HCFC22 (hereinafter called 'R22'), HCFC123 (hereinafter called 'R123') and Mixture of HFC fluid (hereinafter called 'R407C'). The fluid R407C are mixture of HFC32, HFC134a and HFC125, and their concentrations are 23wt%, 52wt% and 25wt%, respectively. This paper presents main flow parameters such as void fraction, interfacial velocities, bubble diameter distribution and pressure drop multiplier, which can characterize flow behavior. The void fractions and interfacial velocities were measured at some local positions in the single pipe using the bi-optical probe(hereinafter called 'BOP'). The procedure to calculate the void fraction from the void signals obtained by BOP were adopted the so-called slice method. The effects of slice levels on the void fraction were discussed taking into account bubble diameter. The new correlation of slice level as the function of void fraction has been proposed. The area-averaged void fractions obtained from BOP's void signals using new correlation were compared with void fractions obtained from pressure drops. The area-averaged interfacial velocities were also compared with the superficial gas velocities. It was concluded that the accuracy of BOP measurements are 5% for void fraction and less than 8.5% for interfacial velocity

  6. Clinical significance of determination of changes of serum APN, BNP and ANF levels after treatment in patients with heart failure

    International Nuclear Information System (INIS)

    Ge Hengsong; Hu Min; Gao Xinchun

    2011-01-01

    Objective: To explore the significance of changes on serum APN, BNP and ANF levels after treatment in patients with heart failure. Methods: Serum BNP, ANF(with RIA) serum APN (with ELISA) levels were determined in 30 patients with heart failure both before and after treatment as well as in 35 normal controls. Results: Before treatment, serum APN level was significantly lower than those in controls (P<0.01), but serum BNP, ANF levels were apparently higher (P<0.01). After 1 month of treatment, the levels dropped markedly, but still remained obviously higher (P<0.05). Conclusion: Serum APN, BNP and ANF levels were closely related to the process of heart failure and were of clinical value of monitoring therapeutic effect and prognosis. (authors)

  7. Evaporation of refrigerant HFC 407C on plain tubes or at an improved surface; Evaporation du refrigerant HFC 407C sur des tubes lisses ou a surface amelioree

    Energy Technology Data Exchange (ETDEWEB)

    Zuercher, O.; Favrat, D.; Thome, J. R.; Kattan, N.; Nidegger, E. [Ecole polytechnique federale, Lab. d` energetique industrielle, Lausanne (Switzerland)

    1996-11-15

    The substitution of CFC refrigerants in refrigeration systems, heat pumps and organic Rankine cycles for heat recovery, requires good methods for predicting heat transfer of substitute fluids. The measurements in the LENI test facility (concentric tubes with water flowing in a counter-current flow) with HFC 407C, HFC 134a, HCFC 123, HFC 404a and HFC/HCFC 402A provide a new data bank for new refrigerants, and allow a coherent comparison with old refrigerants CFC 11, CFC 12, CFC/HCFC 502 and with existing correlations. The existing correlations were found to be inadequate. Because of this work, an improved flow pattern map and flow boiling model were developed, which resulted in a substantial progress in the accurate predict of heat transfer in plain, horizontal tubes for refrigerants without oil. The Kattan et al. correlation was programmed to calculate and compare predicted heat transfer coefficients to the new HFC 407C test data. The flow pattern map proposed by Kattan et al. was also programmed and compared to flow regimes observed for HFC 407C. It predicted the HFC 407C flow pattern data quite accurately. The original objective of the HFC 407C measurements was the validation of the Kattan et al. correlation applied to a zeotropic refrigerant blend. Local flow boiling heat transfer coefficients were measured for HFC 407C evaporating inside a microfin and a plain tube. In addition, microfin heat transfer augmentation relative to a plain tube was investigated. The presence of oil in the evaporator had a complex effect on heat transfer coefficients. Local flow boiling heat transfer coefficients were measured for refrigerant HFC 407C ester oil mixtures (Mobil EAL Arctic 68). A new thermodynamic approach for modeling mixtures of zeotropic refrigerant blends and lubricating oils was also developed. (author) figs., tabs., 14 refs.

  8. Hydrofluorocarbon (HFC) Scenarios, Climate Effects and the Montreal Protocol

    Science.gov (United States)

    Velders, G. J. M.; Fahey, D. W.; Daniel, J. S.

    2016-12-01

    The Montreal Protocol has reduced the use of ozone-depleting substances by more than 95% from its peak levels in the 1980s. As a direct result the use of hydrofluorocarbons (HFCs) as substitute compounds has increased significantly. National regulations to limit HFC use have been adopted recently in the European Union, Japan and USA, and four proposals have been submitted to amend the Montreal Protocol to substantially reduce growth in HFC use. The Parties of the Montreal Protocol have discussed these proposals during their meetings in 2016. The effects of the national regulations and Montreal Protocol amendment proposals on climate forcings and surface temperatures will be presented. Global scenarios of HFC emissions reach 4.0-5.3 GtCO2-eq yr-1 in 2050, which corresponds to a projected growth from 2015 to 2050 which is 9% to 29% of that for CO2 over the same time period. In 2050, in percent of global HFC emissions, China ( 30%), India and the rest of Asia ( 25%), Middle East and northern Africa ( 10%), and USA ( 10%) are the principal source regions; and refrigeration and stationary air conditioning are the major use sectors. Calculated baseline emissions are reduced by 90% in 2050 by implementing the North America Montreal Protocol amendment proposal. This corresponds to a reduction in surface temperature attributed to HFCs from 0.1 oC to 0.04 oC in 2050 and from 0.3-0.4 oC to 0.02 oC in 2100.

  9. HFC-134A and HCFC-22 supermarket refrigeration demonstration and laboratory testing. Phase I. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    Aspen Systems and a team of nineteen agencies and industry participants conducted a series of tests to determine the performance of HFC-134a, HCFC-22, and CFC-502 for supermarket application. This effort constitutes the first phase of a larger project aimed at carrying out both laboratory and demonstration tests of the most viable HFC refrigerants and the refrigerants they replace. The results of the Phase I effort are presented in the present report. The second phase of the project has also been completed. It centered on testing all viable HFC replacement refrigerants for CFC-502. These were HFC-507, HFC-404A, and HFC-407A. The latter results are published in the Phase II report for this project. As part of Phase I, a refrigeration rack utilizing a horizontal open drive screw compressor was constructed in our laboratory. This refrigeration rack is a duplicate of one we have installed in a supermarket in Clifton Park, NY.

  10. Rate constants for the reactions of OH with HFC-134a (CF3CH2F) and HFC-134 (CHF2CHF2)

    Science.gov (United States)

    Demore, W. B.

    1993-01-01

    Measurements of rate constants for HFC-134 (CF2HCF2H) relative to CH3CCl3, HFC-125, and HFC-134a are reported. The measurements were made in a slow-flow, temperature controlled photochemical reactor, and were based on relative rates of disappearance of the parent compounds as measured by FTIR spectroscopy. Hydroxyl radicals were generated by 254-nm photolysis of O3 in the presence of water vapor. NASA/JPL rate constants for the reference compounds are used to derive temperature-dependent rate constants of both compounds. Rate constants obtained from the different reference compounds are in excellent agreement. The presently recommended rate constant for HFC-134a is about 25 percent too high.

  11. Liquid-air partition coefficients of 1,1-difluoroethane (HFC152a), 1,1,1-trifluoroethane (HFC143a), 1,1,1,2-tetrafluoroethane (HFC134a), 1,1,1,2,2-pentafluoroethane (HFC125) and 1,1,1,3,3-pentafluoropropane (HFC245fa).

    Science.gov (United States)

    Ernstgård, Lena; Lind, Birger; Andersen, Melvin E; Johanson, Gunnar

    2010-01-01

    Blood-air and tissue-blood coefficients (lambda) are essential to characterize the uptake and disposition of volatile substances, e.g. by physiologically based pharmacokinetic (PBPK) modelling. Highly volatile chemicals, including many hydrofluorocarbons (HFC) have low solubility in liquid media. These characteristics pose challenges for determining lambda values. A modified head-space vial equilibrium method was used to determine lambda values for five widely used HFCs. The method is based on automated head-space gas chromatography and injection of equal amount of chemical in two head-space vials with identical air phase volumes but different volumes of the liquid phase. The liquids used were water (physiological saline), fresh human blood, and olive oil. The average lambda values (n = 8) were as follows: 1,1-difluoroethane (HFC152a) - 1.08 (blood-air), 1.11 (water-air) and 5.6 (oil-air); 1,1,1-trifluoroethane (HFC143a) - 0.15, 0.15 and 1.90; 1,1,1,2-tetrafluoroethane (HFC134a) - 0.36, 0.35 and 3.5; 1,1,1,2,2-pentafluoroethane (HFC125) - 0.083, 0.074 and 1.71; and 1,1,1,3,3-pentafluoropropane (HFC245fa) - 0.62, 0.58 and 12.1. The lambda values appeared to be concentration-independent in the investigated range (2-200 ppm). In spite of the low lambda values, the method errors were modest, with coefficients of variation of 9, 11 and 10% for water, blood and oil, respectively.

  12. HfC plasma coating of C/C composites

    International Nuclear Information System (INIS)

    Boncoeur, M.; Schnedecker, G.; Lulewicz, J.D.

    1992-01-01

    The surface properties of C/C composites such as hardness and corrosion or erosion resistance can be modified by a ceramic coating applied by plasma torch. The technique of plasma spraying in controlled temperature and atmosphere, that was developed and patented by the CEA, makes it possible to apply coatings to the majority of metals and ceramics without affecting the characteristics of the composite. An example of hard deposit of HfC on a C/C composite is described. The characteristics of the deposit and of the bonding with the C/C composite were studied before and after a heat treatment under vacuum for 2 hours at 1000 C. 2 refs

  13. Celebrating 10 Years of Delivering EarthScope USArray Transportable Array Data from the Array Network Facility (ANF)

    Science.gov (United States)

    Eakins, J. A.; Vernon, F.; Astiz, L.; Davis, G. A.; Reyes, J. C.; Martynov, V. G.; Tytell, J.; Cox, T. A.; Meyer, J.

    2013-12-01

    Since 2004, the Array Network Facility (ANF) has been responsible for generation and delivery of the metadata as well as collection and initial quality control and the transmission of the seismic, and more recently infrasound and meteorological data, for the Earthscope USArray Transportable Array. As of August 2013, we have managed data from over 1600 stations. Personnel at the ANF provide immediate eyes on the data to improve quality control as well as interact with the individual stations via calibrations, mass recentering, baler data retrieval and event analysis. Web-based tools have been developed, and rewritten over the years, to serve the needs of both station engineers and the public. Many lessons on the needs for scalability have been learned. Analysts continue to review all seismic events recorded on 7 or more TA stations making associations against externally available bulletins and/or generating ANF authored locations which are available at both the ANF and IRIS-DMC. The US Array pressure data have several unique characteristics that are allowing us to conduct a rigorous analysis of the spatio-temporal variations in the pressure field on time scales of less than an hour across the eastern United States. With the installation of the infrasound and atmospheric pressure sensors, starting in 2010, observations of gust fronts, near misses of tornados at individual stations, and of the mesoscale gravity waves showing the value and utility of the US Array pressure data will be presented.

  14. Experimental study of hydrocarbon mixtures to replace HFC-134a in a domestic refrigerator

    International Nuclear Information System (INIS)

    Wongwises, Somchai; Chimres, Nares

    2005-01-01

    This work presents an experimental study on the application of hydrocarbon mixtures to replace HFC-134a in a domestic refrigerator. The hydrocarbons investigated are propane (R290), butane (R600) and isobutane (R600a). A refrigerator designed to work with HFC-134a with a gross capacity of 239 l is used in the experiment. The consumed energy, compressor power and refrigerant temperature and pressure at the inlet and outlet of the compressor are recorded and analysed as well as the distributions of temperature at various positions in the refrigerator. The refrigerant mixtures used are divided into three groups: the mixture of three hydrocarbons, the mixture of two hydrocarbons and the mixture of two hydrocarbons and HFC-134a. The experiments are conducted with the refrigerants under the same no load condition at a surrounding temperature of 25 deg. C. The results show that propane/butane 60%/40% is the most appropriate alternative refrigerant to HFC-134a

  15. HFC-23 (CHF3 emission trend response to HCFC-22 (CHClF2 production and recent HFC-23 emission abatement measures

    Directory of Open Access Journals (Sweden)

    R. G. Prinn

    2010-08-01

    Full Text Available HFC-23 (also known as CHF3, fluoroform or trifluoromethane is a potent greenhouse gas (GHG, with a global warming potential (GWP of 14 800 for a 100-year time horizon. It is an unavoidable by-product of HCFC-22 (CHClF2, chlorodifluoromethane production. HCFC-22, an ozone depleting substance (ODS, is used extensively in commercial refrigeration and air conditioning, in the extruded polystyrene (XPS foam industries (dispersive applications and also as a feedstock in fluoropolymer manufacture (a non-dispersive use. Aside from small markets in specialty uses, HFC-23 has historically been considered a waste gas that was, and often still is, simply vented to the atmosphere. Efforts have been made in the past two decades to reduce HFC-23 emissions, including destruction (incineration in facilities in developing countries under the United Nations Framework Convention on Climate Change's (UNFCCC Clean Development Mechanism (CDM, and by process optimization and/or voluntary incineration by most producers in developed countries. We present observations of lower-tropospheric mole fractions of HFC-23 measured by "Medusa" GC/MSD instruments from ambient air sampled in situ at the Advanced Global Atmospheric Gases Experiment (AGAGE network of five remote sites (2007–2009 and in Cape Grim air archive (CGAA samples (1978–2009 from Tasmania, Australia. These observations are used with the AGAGE 2-D atmospheric 12-box model and an inverse method to produce model mole fractions and a "top-down" HFC-23 emission history. The model 2009 annual mean global lower-tropospheric background abundance is 22.6 (±0.2 pmol mol−1. The derived HFC-23 emissions show a "plateau" during 1997–2003, followed by a rapid ~50% increase to a peak of 15.0 (+1.3/−1.2 Gg/yr in 2006. Following this peak, emissions of HFC-23 declined rapidly to 8.6 (+0.9/−1.0 Gg/yr in 2009, the lowest annual emission of the past 15 years. We derive a 1990–2008 "bottom-up" HFC-23 emission history

  16. Introduction of the new process and quality control methods in fuel fabrication at Siemens/ANF

    International Nuclear Information System (INIS)

    Rogge, K.T.; Fickers, H.H.; Doerr, W.

    2000-01-01

    The central point of ANFs quality philosophy is the process of continuous improvements. With respect to the causes of defects and the efforts needed for elimination, the importance of continuous improvements is evident. In most of the cases, defects are caused in the initial stages of a product but the majority of the problems will be only detected during fabrication and inspection and in the worst case when the product is already in use. Goal of the improvement process is to assure a high product quality. Therefore, the efforts are focused on robust and centered processes. A reasonable quality planning is the basis for achieving and maintaining the quality targets. Quality planning includes prefabrication studies, in-process inspections and final inspections. The inspections provide a large amount of various quality data, process parameters as well as product proper-ties. Key data will be defined and subjected to a statistical analysis. In view of the effectiveness of the analysis, it is important, that the process parameters which influence the characteristics of the product are well known and that appropriate methods for data evaluation and visualization will be used. Main approach of the data visualization is to obtain a tighter control of the product properties and to improve the process robustness by implementation of defined improvements. With respect to the fuel safety and fuel performance, the presentation shows for typical product quality characteristics some examples of visualized quality data. The examples includes the integrity of the pellet column (rod scanner results), the spring force of PWR spacers (critical characteristic with regard to rod fretting) and the spacer intersection weld size (thermo-hydraulic fuel bundle behaviour). The presentation also includes an example for the statistical process control, the in-line surveillance of the fuel rod weld parameters which assures the integrity of the welds within tight tolerance ranges. The quality

  17. New Regional and Global HFC Projections and Effects of National Regulations and Montreal Protocol Amendment Proposals

    Science.gov (United States)

    Velders, G. J. M.

    2015-12-01

    Hydrofluorocarbons (HFCs) are used as substitutes for ozone-depleting substances that are being phased out globally under Montreal Protocol regulations. New global scenarios of HFC emissions reach 4.0-5.3 GtCO2-eq yr-1 in 2050, which corresponds to a projected growth from 2015 to 2050 which is 9% to 29% of that for CO2 over the same time period. New baseline scenarios are formulated for 10 HFC compounds, 11 geographic regions, and 13 use categories. These projections are the first to comprehensively assess production and consumption of individual HFCs in multiple use sectors and geographic regions with emission estimates constrained by atmospheric observations. In 2050, in percent of global HFC emissions, China (~30%), India and the rest of Asia (~25%), Middle East and northern Africa (~10%), and USA (~10%) are the principal source regions; and refrigeration and stationary air conditioning are the major use sectors. National regulations to limit HFC use have been adopted recently in the European Union, Japan and USA, and four proposals have been submitted in 2015 to amend the Montreal Protocol to substantially reduce growth in HFC use. Calculated baseline emissions are reduced by 90% in 2050 by implementing the North America Montreal Protocol amendment proposal. Global adoption of technologies required to meet national regulations would be sufficient to reduce 2050 baseline HFC consumption by more than 50% of that achieved with the North America proposal for most developed and developing countries. The new HFC scenarios and effects of national regulations and Montreal Protocol amendment proposals will be presented.

  18. Resolution of the uncertainties in the radiative forcing of HFC-134a

    International Nuclear Information System (INIS)

    Forster, Piers M. de F; Burkholder, J.B.; Clerbaux, C.; Coheur, P.F.; Dutta, M.; Gohar, L.K.; Hurley, M.D.; Myhre, G.; Portmann, R.W.; Shine, K.P.; Wallington, T.J.; Wuebbles, D.

    2005-01-01

    HFC-134a (CF 3 CH 2 F) is the most rapidly growing hydrofluorocarbon in terms of atmospheric abundance. It is currently used in a large number of household refrigerators and air-conditioning systems and its concentration in the atmosphere is forecast to increase substantially over the next 50-100 years. Previous estimates of its radiative forcing per unit concentration have differed significantly ∼25%. This paper uses a two-step approach to resolve this discrepancy. In the first step six independent absorption cross section datasets are analysed. We find that, for the integrated cross section in the spectral bands that contribute most to the radiative forcing, the differences between the various datasets are typically smaller than 5% and that the dependence on pressure and temperature is not significant. A 'recommended' HFC-134a infrared absorption spectrum was obtained based on the average band intensities of the strongest bands. In the second step, the 'recommended' HFC-134a spectrum was used in six different radiative transfer models to calculate the HFC-134a radiative forcing efficiency. The clear-sky instantaneous radiative forcing, using a single global and annual mean profile, differed by 8%, between the 6 models, and the latitudinally-resolved adjusted cloudy sky radiative forcing estimates differed by a similar amount. We calculate that the radiative forcing efficiency of HFC-134a is 0.16+/-0.02Wm -2 ppbv -1

  19. The large contribution of projected HFC emissions to future climate forcing.

    Science.gov (United States)

    Velders, Guus J M; Fahey, David W; Daniel, John S; McFarland, Mack; Andersen, Stephen O

    2009-07-07

    The consumption and emissions of hydrofluorocarbons (HFCs) are projected to increase substantially in the coming decades in response to regulation of ozone depleting gases under the Montreal Protocol. The projected increases result primarily from sustained growth in demand for refrigeration, air-conditioning (AC) and insulating foam products in developing countries assuming no new regulation of HFC consumption or emissions. New HFC scenarios are presented based on current hydrochlorofluorocarbon (HCFC) consumption in leading applications, patterns of replacements of HCFCs by HFCs in developed countries, and gross domestic product (GDP) growth. Global HFC emissions significantly exceed previous estimates after 2025 with developing country emissions as much as 800% greater than in developed countries in 2050. Global HFC emissions in 2050 are equivalent to 9-19% (CO(2)-eq. basis) of projected global CO(2) emissions in business-as-usual scenarios and contribute a radiative forcing equivalent to that from 6-13 years of CO(2) emissions near 2050. This percentage increases to 28-45% compared with projected CO(2) emissions in a 450-ppm CO(2) stabilization scenario. In a hypothetical scenario based on a global cap followed by 4% annual reductions in consumption, HFC radiative forcing is shown to peak and begin to decline before 2050.

  20. Human safety and pharmacokinetics of the CFC alternative propellants HFC 134a (1,1,1,2-tetrafluoroethane) and HFC 227 (1,1,1,2,3,3,3-heptafluoropropane) following whole-body exposure

    NARCIS (Netherlands)

    Emmen, H.H.; Hoogendijk, E.M.G.; Klöpping-Ketelaars, W.A.A.; Muijser, H.; Duistermaat, E.; Ravensberg, J.C.; Alexander, D.J.; Borkhataria, D.; Rusch, G.M.; Schmit, B.

    2000-01-01

    HFC 134a (1,1,1,2-tetrafluoroethane) and HFC 227 (1,1,1,2,3,3,3-heptafluoropropane) are used to replace chlorofluorocarbons (CFCs) in refrigerant and aerosol applications, including medical use in metered-dose inhalers. Production and consumption of CFCs are being phased out under the Montreal

  1. Future atmospheric abundances and climate forcings from scenarios of global and regional hydrofluorocarbon (HFC) emissions

    Science.gov (United States)

    Velders, Guus J. M.; Fahey, David W.; Daniel, John S.; Andersen, Stephen O.; McFarland, Mack

    2015-12-01

    Hydrofluorocarbons (HFCs) are manufactured for use as substitutes for ozone-depleting substances that are being phased out globally under Montreal Protocol regulations. While HFCs do not deplete ozone, many are potent greenhouse gases that contribute to climate change. Here, new global scenarios show that baseline emissions of HFCs could reach 4.0-5.3 GtCO2-eq yr-1 in 2050. The new baseline (or business-as-usual) scenarios are formulated for 10 HFC compounds, 11 geographic regions, and 13 use categories. The scenarios rely on detailed data reported by countries to the United Nations; projections of gross domestic product and population; and recent observations of HFC atmospheric abundances. In the baseline scenarios, by 2050 China (31%), India and the rest of Asia (23%), the Middle East and northern Africa (11%), and the USA (10%) are the principal source regions for global HFC emissions; and refrigeration (40-58%) and stationary air conditioning (21-40%) are the major use sectors. The corresponding radiative forcing could reach 0.22-0.25 W m-2 in 2050, which would be 12-24% of the increase from business-as-usual CO2 emissions from 2015 to 2050. National regulations to limit HFC use have already been adopted in the European Union, Japan and USA, and proposals have been submitted to amend the Montreal Protocol to substantially reduce growth in HFC use. Calculated baseline emissions are reduced by 90% in 2050 by implementing the North America Montreal Protocol amendment proposal. Global adoption of technologies required to meet national regulations would be sufficient to reduce 2050 baseline HFC consumption by more than 50% of that achieved with the North America proposal for most developed and developing countries.

  2. Diversidade de anfíbios do Estado de Mato Grosso do Sul, Brasil

    Directory of Open Access Journals (Sweden)

    Franco L. Souza

    Full Text Available RESUMO A fauna de anfíbios do estado de Mato Grosso do Sul foi compilada e elaborada pela primeira vez, totalizando 97 espécies, o que representa pouco mais de 10% das espécies que ocorrem no Brasil. Nove famílias e 25 gêneros de Anura e apenas uma espécie de Gymnophiona foram registradas. As áreas de Cerrado apresentaram a maior riqueza, seguidas pelas florestas estacionais semideciduais, Chaco e veredas. Em relação às macrorregiões consideradas, foram registradas 56 espécies para a planície de inundação (majoritariamente representada pelo Pantanal e 92 para o planalto. As regiões mais amostradas em Mato Grosso do Sul são o Parque Nacional da Serra da Bodoquena e algumas áreas do Pantanal, o que resulta em lacunas de amostragens por todo o estado, principalmente nas regiões norte, leste/sudeste e parte do oeste/sudoeste. Foram identificadas áreas consideradas importantes para amostragens em decorrência da complexidade de fitofisionomias e relevos encontrados no estado: Maciço do rio Apa, Serra de Maracaju, grande parte do Chaco brasileiro, leque do rio Taquari, planalto do Taquari-Itiquira, escarpas do planalto Central, áreas úmidas/florestas estacionais da planície do rio Paraná e áreas interioranas do Pantanal, onde o acesso é difícil.

  3. Comparison of four inverse modelling systems applied to the estimation of HFC-125, HFC-134a, and SF6 emissions over Europe

    Directory of Open Access Journals (Sweden)

    D. Brunner

    2017-09-01

    Full Text Available Hydrofluorocarbons (HFCs are used in a range of industrial applications and have largely replaced previously used gases (CFCs and HCFCs. HFCs are not ozone-depleting but have large global warming potentials and are, therefore, reported to the United Nations Framework Convention on Climate Change (UNFCCC. Here, we use four independent inverse models to estimate European emissions of the two HFCs contributing the most to global warming (HFC-134a and HFC-125 and of SF6 for the year 2011. Using an ensemble of inverse models offers the possibility to better understand systematic uncertainties in inversions. All systems relied on the same measurement time series from Jungfraujoch (Switzerland, Mace Head (Ireland, and Monte Cimone (Italy and the same a priori estimates of the emissions, but differed in terms of the Lagrangian transport model (FLEXPART, NAME, inversion method (Bayesian, extended Kalman filter, treatment of baseline mole fractions, spatial gridding, and a priori uncertainties. The model systems were compared with respect to the ability to reproduce the measurement time series, the spatial distribution of the posterior emissions, uncertainty reductions, and total emissions estimated for selected countries. All systems were able to reproduce the measurement time series very well, with prior correlations between 0.5 and 0.9 and posterior correlations being higher by 0.05 to 0.1. For HFC-125, all models estimated higher emissions from Spain + Portugal than reported to UNFCCC (median higher by 390 % though with a large scatter between individual estimates. Estimates for Germany (+140 % and Ireland (+850 % were also considerably higher than UNFCCC, whereas the estimates for France and the UK were consistent with the national reports. In contrast to HFC-125, HFC-134a emissions from Spain + Portugal were broadly consistent with UNFCCC, and emissions from Germany were only 30 % higher. The data suggest that the UK over

  4. Comparison of four inverse modelling systems applied to the estimation of HFC-125, HFC-134a, and SF6 emissions over Europe

    Science.gov (United States)

    Brunner, Dominik; Arnold, Tim; Henne, Stephan; Manning, Alistair; Thompson, Rona L.; Maione, Michela; O'Doherty, Simon; Reimann, Stefan

    2017-09-01

    Hydrofluorocarbons (HFCs) are used in a range of industrial applications and have largely replaced previously used gases (CFCs and HCFCs). HFCs are not ozone-depleting but have large global warming potentials and are, therefore, reported to the United Nations Framework Convention on Climate Change (UNFCCC). Here, we use four independent inverse models to estimate European emissions of the two HFCs contributing the most to global warming (HFC-134a and HFC-125) and of SF6 for the year 2011. Using an ensemble of inverse models offers the possibility to better understand systematic uncertainties in inversions. All systems relied on the same measurement time series from Jungfraujoch (Switzerland), Mace Head (Ireland), and Monte Cimone (Italy) and the same a priori estimates of the emissions, but differed in terms of the Lagrangian transport model (FLEXPART, NAME), inversion method (Bayesian, extended Kalman filter), treatment of baseline mole fractions, spatial gridding, and a priori uncertainties. The model systems were compared with respect to the ability to reproduce the measurement time series, the spatial distribution of the posterior emissions, uncertainty reductions, and total emissions estimated for selected countries. All systems were able to reproduce the measurement time series very well, with prior correlations between 0.5 and 0.9 and posterior correlations being higher by 0.05 to 0.1. For HFC-125, all models estimated higher emissions from Spain + Portugal than reported to UNFCCC (median higher by 390 %) though with a large scatter between individual estimates. Estimates for Germany (+140 %) and Ireland (+850 %) were also considerably higher than UNFCCC, whereas the estimates for France and the UK were consistent with the national reports. In contrast to HFC-125, HFC-134a emissions from Spain + Portugal were broadly consistent with UNFCCC, and emissions from Germany were only 30 % higher. The data suggest that the UK over-reports its HFC-134a emissions to

  5. The Earthscope USArray Array Network Facility (ANF): Metadata, Network and Data Monitoring, Quality Assurance During the Second Year of Operations

    Science.gov (United States)

    Eakins, J. A.; Vernon, F. L.; Martynov, V.; Newman, R. L.; Cox, T. A.; Lindquist, K. L.; Hindley, A.; Foley, S.

    2005-12-01

    The Array Network Facility (ANF) for the Earthscope USArray Transportable Array seismic network is responsible for: the delivery of all Transportable Array stations (400 at full deployment) and telemetered Flexible Array stations (up to 200) to the IRIS Data Management Center; station command and control; verification and distribution of metadata; providing useful remotely accessible world wide web interfaces for personnel at the Array Operations Facility (AOF) to access state of health information; and quality control for all data. To meet these goals, we use the Antelope software package to facilitate data collection and transfer, generation and merging of the metadata, real-time monitoring of dataloggers, generation of station noise spectra, and analyst review of individual events. Recently, an Antelope extension to the PHP scripting language has been implemented which facilitates the dynamic presentation of the real-time data to local web pages. Metadata transfers have been simplified by the use of orb transfer technologies at the ANF and receiver end points. Web services are being investigated as a means to make a potentially complicated set of operations easy to follow and reproduce for each newly installed or decommissioned station. As part of the quality control process, daily analyst review has highlighted areas where neither the regional network bulletins nor the USGS global bulletin have published solutions. Currently four regional networks (Anza, BDSN, SCSN, and UNR) contribute data to the Transportable Array with additional contributors expected. The first 100 stations (42 new Earthscope stations) were operational by September 2005 with all but one of the California stations installed. By year's end, weather permitting, the total number of stations deployed is expected to be around 145. Visit http://anf.ucsd.edu for more information on the project and current status.

  6. HEAT TRANSFER EVALUATION OF HFC-236FA IN CONDENSATION AND EVAPORATION

    Science.gov (United States)

    The report gives results of an evaluation of the shell-side heat transfer performance of hydrofluorocarbon (HFC)-236fa, which is considered to be a potential substitute for chlorofluorocarbon (CFC)-114 in Navy shipboard chillers, for both conventional finned [1024- and 1575-fpm (...

  7. HEAT TRANSFER EVALUATION OF HFC-236EA WITH HIGH PERFORMANCE ENHANCED TUBES IN CONDENSATION AND EVAPORATION

    Science.gov (United States)

    The report gives results of an evaluation of the heat transfer performance of pure hydrofluorocarbon (HFC)-236ea for high performance enhanced tubes which had not been previously used in Navy shipboard chillers. Shell-side heat transfer coefficient data are presented for condensa...

  8. HEAT TRANSFER EVALUATION OF HFC-236EA AND CFC-114 IN CONDENSATION AND EVAPORATION

    Science.gov (United States)

    The report gives results of a heat transfer evaluation of the refrigerants hexafluoropropane (HFC-236ea) and 1,1,2,2-dichloro-tetrafluoroethane (CFC-114). (NOTE: With the mandatory phase-out of chlorofluorocarbons (CFCs), as dictated by the Montreal Protocol and Clean Air Act Ame...

  9. MODELING AND DESIGN STUDY USING HFC-236EA AS AN ALTERNATIVE REFRIGERANT IN A CENTRIFUGAL COMPRESSOR

    Science.gov (United States)

    The report gives results of an investigation of the operation of a centrifugal compressor--part of a chlorofluorocarbon (CFC)-114 chiller installation--with the new refrigerant hydrofluorocarbon (HFC)-236ea, a proposed alternative to CFC-114. A large set of CFC-236ea operating da...

  10. The Earthscope USArray Array Network Facility (ANF): Evolution of Data Acquisition, Processing, and Storage Systems

    Science.gov (United States)

    Davis, G. A.; Battistuz, B.; Foley, S.; Vernon, F. L.; Eakins, J. A.

    2009-12-01

    Since April 2004 the Earthscope USArray Transportable Array (TA) network has grown to over 400 broadband seismic stations that stream multi-channel data in near real-time to the Array Network Facility in San Diego. In total, over 1.7 terabytes per year of 24-bit, 40 samples-per-second seismic and state of health data is recorded from the stations. The ANF provides analysts access to real-time and archived data, as well as state-of-health data, metadata, and interactive tools for station engineers and the public via a website. Additional processing and recovery of missing data from on-site recorders (balers) at the stations is performed before the final data is transmitted to the IRIS Data Management Center (DMC). Assembly of the final data set requires additional storage and processing capabilities to combine the real-time data with baler data. The infrastructure supporting these diverse computational and storage needs currently consists of twelve virtualized Sun Solaris Zones executing on nine physical server systems. The servers are protected against failure by redundant power, storage, and networking connections. Storage needs are provided by a hybrid iSCSI and Fiber Channel Storage Area Network (SAN) with access to over 40 terabytes of RAID 5 and 6 storage. Processing tasks are assigned to systems based on parallelization and floating-point calculation needs. On-site buffering at the data-loggers provide protection in case of short-term network or hardware problems, while backup acquisition systems at the San Diego Supercomputer Center and the DMC protect against catastrophic failure of the primary site. Configuration management and monitoring of these systems is accomplished with open-source (Cfengine, Nagios, Solaris Community Software) and commercial tools (Intermapper). In the evolution from a single server to multiple virtualized server instances, Sun Cluster software was evaluated and found to be unstable in our environment. Shared filesystem

  11. Future emissions and atmospheric fate of HFC-1234yf from mobile air conditioners in Europe.

    Science.gov (United States)

    Henne, Stephan; Shallcross, Dudley E; Reimann, Stefan; Xiao, Ping; Brunner, Dominik; O'Doherty, Simon; Buchmann, Brigitte

    2012-02-07

    HFC-1234yf (2,3,3,3-tetrafluoropropene) is under discussion for replacing HFC-134a (1,1,1,2-tetrafluoroethane) as a cooling agent in mobile air conditioners (MACs) in the European vehicle fleet. Some HFC-1234yf will be released into the atmosphere, where it is almost completely transformed to the persistent trifluoroacetic acid (TFA). Future emissions of HFC-1234yf after a complete conversion of the European vehicle fleet were assessed. Taking current day leakage rates and predicted vehicle numbers for the year 2020 into account, European total HFC-1234yf emissions from MACs were predicted to range between 11.0 and 19.2 Gg yr(-1). Resulting TFA deposition rates and rainwater concentrations over Europe were assessed with two Lagrangian chemistry transport models. Mean European summer-time TFA mixing ratios of about 0.15 ppt (high emission scenario) will surpass previously measured levels in background air in Germany and Switzerland by more than a factor of 10. Mean deposition rates (wet + dry) of TFA were estimated to be 0.65-0.76 kg km(-2) yr(-1), with a maxium of ∼2.0 kg km(-2) yr(-1) occurring in Northern Italy. About 30-40% of the European HFC-1234yf emissions were deposited as TFA within Europe, while the remaining fraction was exported toward the Atlantic Ocean, Central Asia, Northern, and Tropical Africa. Largest annual mean TFA concentrations in rainwater were simulated over the Mediterranean and Northern Africa, reaching up to 2500 ng L(-1), while maxima over the continent of about 2000 ng L(-1) occurred in the Czech Republic and Southern Germany. These highest annual mean concentrations are at least 60 times lower than previously determined to be a safe level for the most sensitive aquatic life-forms. Rainwater concentrations during individual rain events would still be 1 order of magnitude lower than the no effect level. To verify these results future occasional sampling of TFA in the atmospheric environment should be considered. If future HFC-1234yf

  12. Global emissions of refrigerants HCFC-22 and HFC-134a: Unforeseen seasonal contributions

    Science.gov (United States)

    Xiang, Bin; Montzka, Stephen A.; Miller, Scot M.; Elkins, James W.; Moore, Fred L.; Atlas, Elliot L.; Miller, Ben R.; Weiss, Ray F.; Prinn, Ronald G.; Wofsy, Steven C.

    2014-01-01

    HCFC-22 (CHClF2) and HFC-134a (CH2FCF3) are two major gases currently used worldwide in domestic and commercial refrigeration and air conditioning. HCFC-22 contributes to stratospheric ozone depletion, and both species are potent greenhouse gases. In this work, we study in situ observations of HCFC-22 and HFC-134a taken from research aircraft over the Pacific Ocean in a 3-y span [HIaper-Pole-to-Pole Observations (HIPPO) 2009–2011] and combine these data with long-term ground observations from global surface sites [National Oceanic and Atmospheric Administration (NOAA) and Advanced Global Atmospheric Gases Experiment (AGAGE) networks]. We find the global annual emissions of HCFC-22 and HFC-134a have increased substantially over the past two decades. Emissions of HFC-134a are consistently higher compared with the United Nations Framework Convention on Climate Change (UNFCCC) inventory since 2000, by 60% more in recent years (2009–2012). Apart from these decadal emission constraints, we also quantify recent seasonal emission patterns showing that summertime emissions of HCFC-22 and HFC-134a are two to three times higher than wintertime emissions. This unforeseen large seasonal variation indicates that unaccounted mechanisms controlling refrigerant gas emissions are missing in the existing inventory estimates. Possible mechanisms enhancing refrigerant losses in summer are (i) higher vapor pressure in the sealed compartment of the system at summer high temperatures and (ii) more frequent use and service of refrigerators and air conditioners in summer months. Our results suggest that engineering (e.g., better temperature/vibration-resistant system sealing and new system design of more compact/efficient components) and regulatory (e.g., reinforcing system service regulations) steps to improve containment of these gases from working devices could effectively reduce their release to the atmosphere. PMID:25422438

  13. Development of two-stage compression heat pump for hot water supply in commercial use. Research of compatibility with alternative refrigerant, HFC-134a; Gyomuyo nidan asshukushiki kyuto heat pump no kaihatsu. Daitai reibai HFC-134a no tekiyosei kensho

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, K.; Hasegawa, H.; Saikawa, M.; Iwatsubo, T.; Mimaki, T. [Central Research Institute of Electric Power Industry, Tokyo (Japan)

    1996-03-01

    Performance of two-stage compression and cascade heating heat pump cycle was evaluated in the case using alternative refrigerant, HFC-134a, instead of CFC-12 through calculations and experiments. Heat source and heat load temperature conditions of CFC-12, HFC-134a, and HCFC-22 were calculated. As a result, this cycle provided equivalent coefficient of performance to use of CFC-12 and HCFC-22. Especially for HFC-134a, discharge gas temperature from compressor was much lower than that of the others, which prevented the heat decomposition of refrigerant. It was found that HFC-134a was suitable refrigerant for high temperature output equipment like this cycle. To grasp the possibility of hot water supply at 65 {degree}C and behavior of lubricating oil which can not be obtained only from calculations, applicability of HFC-134a was investigated. Experiments were conducted using a small test apparatus with electric input of 2 kW. As a result, satisfactory performance was obtained for each evaluation item. Applicability of HFC-134a to the two-stage compression cycle was confirmed. 9 refs., 21 figs., 16 tabs.

  14. Investigation into the conditions under which HFC134a may become flammable.

    CSIR Research Space (South Africa)

    Kramers, AP

    2002-01-01

    Full Text Available or approaching 180°C would be associated with an onset of catastrophic conditions such as plant room fires and total mechanical failure of equipment. It is suggested in that the guidelines listed in Section 5.2, pertaining to abnormal plant conditions... /lubricant mixtures can become explosive. The work must therefore consider both normal and abnormal operating conditions to which HFC134a may be exposed to empower machine operators, mine maintenance personnel and contractors to take preventative...

  15. FY 1999 survey report on the survey of destruction technology of HFC, etc. for rationalization of energy use. Survey of the actual state of use/recovery/emissions of HFC, etc.; 1999 nendo energy shiyo gorika HFC nado hakai shori gijutsu chosa hokokusho. HFC nado shiyo kaishu haishutsu jittai chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This survey was aimed at collecting the basic data for studying a possibility of conversion of the recovery system of refrigerant freons, mostly DFC, into HFC, etc., which has been proceeded with in Japan. Of HFCs, PFCs and SF{sub 6} used for survey, only SF{sub 6} is now being recovered and processed. As to HFCs, HFC-134a was arranged, and the recovery/destruction to meet users' handling methods are requested because of the diverse usage and users. The points of the control of emissions of chemical substances into the atmosphere are the decrease in number of times of transport/filling-up at the time of materials handling and the closed system in plants and installation. If considering the heightening of efficiency of materials flow, requested are the decrease in number of times of transport/filling-up, the increase in quantity received by users, and measures to be taken for leakage at the time of receiving. In relation to the conversion of the recovery system of refrigerant freons, mainly CFC, into HFC, etc., all the industries concerned with the generation of the used substances to the materials flow have to promote the technical development for the structure and recovery in cooperation with each other. (NEDO)

  16. Experimental investigation of hydrocarbon mixtures to replace HFC-134a in an automotive air conditioning system

    International Nuclear Information System (INIS)

    Wongwises, Somchai; Kamboon, Amnouy; Orachon, Banchob

    2006-01-01

    This paper presents an experimental study on the application of hydrocarbon mixtures to replace HFC-134a in automotive air conditioners. The hydrocarbons investigated are propane (R290), butane (R600) and isobutane (R600a). The measured data are obtained from an automotive air conditioning test facility utilizing HFC-134a as the refrigerant. The air conditioner, with a capacity of 3.5 kW driven by a Diesel engine, is charged and tested with four different ratios of hydrocarbon mixtures. The experiments are conducted at the same surrounding conditions. The temperature and pressure of the refrigerant at every major position in the refrigerant loop, the temperature, flow rate and humidity of air, torque and engine speed are recorded and analyzed. The parameters investigated are the refrigeration capacity, the compressor power and the coefficient of performance (COP). The results show that propane/butane/isobutane: 50%/40%/10% is the most appropriate alternative refrigerant to replace HFC-134a, having the best performance of all the hydrocarbon mixtures investigated

  17. HFC-152a and HFC-134a emission estimates and characterization of CFCs, CFC replacements, and other halogenated solvents measured during the 2008 ARCTAS campaign (CARB phase) over the South Coast Air Basin of California

    Science.gov (United States)

    Barletta, B.; Nissenson, P.; Meinardi, S.; Dabdub, D.; Sherwood Rowland, F.; Vancuren, R. A.; Pederson, J.; Diskin, G. S.; Blake, D. R.

    2011-03-01

    This work presents results from the NASA Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) study. Whole air samples were obtained on board research flights that flew over California during June 2008 and analyzed for selected volatile organic compounds, including several halogenated species. Samples collected over the South Coast Air Basin of California (SoCAB), which includes much of Los Angeles (LA) County, were compared with samples from inflow air masses over the Pacific Ocean. The levels of many halocarbon species were enhanced significantly over the SoCAB, including compounds regulated by the Montreal Protocol and subsequent amendments. Emissions estimates of HFC-152a (1,1-difluoroethane, CH3CHF2; 0.82 ± 0.11 Gg) and HFC-134a (1,1,1,2-tetrafluoroethane, CH2FCF3; 1.16 ± 0.22 Gg) in LA County for 2008 were obtained using the observed HFC:carbon monoxide (CO) enhancement ratio. Emission rates also were calculated for the SoCAB (1.60 ± 0.22 Gg yr-1 for HFC-152a and 2.12 ± 0.28 Gg yr-1 for HFC-134a) and then extrapolated to the United States (32 ± 4 Gg yr-1 for HFC-152a and 43 ± 6 Gg yr-1 for HFC-134a) using population data. In addition, emission rates of the two HFCs in LA County and SoCAB were calculated by a second method that utilizes air quality modeling. Emissions estimates obtained using both methods differ by less than 25% for the LA County and less than 45% for the SoCAB.

  18. HFC-152a and HFC-134a emission estimates and characterization of CFCs, CFC replacements, and other halogenated solvents measured during the 2008 ARCTAS campaign (CARB phase over the South Coast Air Basin of California

    Directory of Open Access Journals (Sweden)

    B. Barletta

    2011-03-01

    Full Text Available This work presents results from the NASA Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS study. Whole air samples were obtained on board research flights that flew over California during June 2008 and analyzed for selected volatile organic compounds, including several halogenated species. Samples collected over the South Coast Air Basin of California (SoCAB, which includes much of Los Angeles (LA County, were compared with samples from inflow air masses over the Pacific Ocean. The levels of many halocarbon species were enhanced significantly over the SoCAB, including compounds regulated by the Montreal Protocol and subsequent amendments. Emissions estimates of HFC-152a (1,1-difluoroethane, CH3CHF2; 0.82 ± 0.11 Gg and HFC-134a (1,1,1,2-tetrafluoroethane, CH2FCF3; 1.16 ± 0.22 Gg in LA County for 2008 were obtained using the observed HFC:carbon monoxide (CO enhancement ratio. Emission rates also were calculated for the SoCAB (1.60 ± 0.22 Gg yr−1 for HFC-152a and 2.12 ± 0.28 Gg yr−1 for HFC-134a and then extrapolated to the United States (32 ± 4 Gg yr−1 for HFC-152a and 43 ± 6 Gg yr−1 for HFC-134a using population data. In addition, emission rates of the two HFCs in LA County and SoCAB were calculated by a second method that utilizes air quality modeling. Emissions estimates obtained using both methods differ by less than 25% for the LA County and less than 45% for the SoCAB.

  19. Modelling of fluid flow through short tube orifices under metastable conditions: A new numerical validation approach for evaluating the mass flow rate with refrigerant mixtures (HFC-407C and HFC-410A)

    International Nuclear Information System (INIS)

    García-Valladares, O.; Santoyo, E.

    2014-01-01

    In a previous work, one-dimensional numerical modelling of fluid-flow inside short tube orifices was performed, and successfully validated against a wide range of mass flow rate measurements reported for the refrigerant HFC-134a. Governing equations of continuity, momentum, energy and entropy were solved for describing the fluid flow under a wide variety of thermodynamic transitions (e.g., subcooled liquid region, metastable liquid region, metastable two-phase region and equilibrium two-phase region), including sudden contraction and enlargement. In this new study, a comprehensive comparison analysis between numerical simulation data and experimental measurements obtained for HFC-407C and HFC-410A refrigerants (N o  = 241) to extend the applicability of the same mathematical model was carried out. Using a widespread statistical analysis, based on weighted linear regressions with an outlier detection/rejection module at 95% of confidence level, the prediction performance of the mathematical model was again assessed. Linear regressions between predicted mass flow rate data and experimental measurements were computed, and used them as a statistical comparison criterion. A statistical comparison between predicted simulation results and mass flow rate experimental data are reported. Average deviation errors of ±11.1% (for the refrigerant HFC-407C) and ±7.3% (for refrigerant HFC-410A) were found between numerical model and experimental data. These results demonstrate a new and robust application of the model to predict reliably the mass flow rate through short tube orifices under metastable conditions, which enable this tool to be reliably used for the design of short tube orifices. - Highlights: •A modelling for evaluating short tube orifice was developed for refrigerant mixtures. •The numerical model applied considered metastable regions and choke flow. •The model was validated against experimental data for HFC-407C and HFC-410A. •Statistical analysis based

  20. Sudden death involving inhalation of 1,1-difluoroethane (HFC-152a) with spray cleaner: three case reports.

    Science.gov (United States)

    Sakai, Kentaro; Maruyama-Maebashi, Kyoko; Takatsu, Akihiro; Fukui, Kenji; Nagai, Tomonori; Aoyagi, Miwako; Ochiai, Eriko; Iwadate, Kimiharu

    2011-03-20

    Spray cleaner is a cleaning product containing compressed 1,1-difluoroethane (HFC-152a) to blow dust off electric devices and other sensitive equipment; however, it is also inhaled to induce euphoria. This report describes three cases of death involving HFC-152a inhalation with spray cleaner under different circumstances. In case 1, death was during inhalation for euphoria with which led to having frostbite. In case 2, death may have been associated with suicidal intention. Case 3 was also considered an accidental autoerotic death. In all three cases, HFC-152a was detected at 99.2-136.2mg/l in blood samples, 94.5-191.9 mg/l in urine samples and 3.6-18.4 mg in the gastric contents according to gas chromatography with flame ionization detection. To prevent death associated with HFC-152a inhalation from spray cleaner, the danger of the sudden death should be announced to people, given the ready availability of commercial products containing HFC-152a. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  1. Study of thermodynamic properties of HFC refrigerant mixtures for Loretz-cycled niew generation air-conditioning equipment; Lorentz cycle ka shinsedai kucho kikiyo HFC kei kongo reibai no netsu rikigaku seishitsu ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, K; Sato, H [Keio University, Tokyo (Japan). Faculty of Science and Technology

    1997-02-01

    This paper describes thermodynamic properties of HFC refrigerant mixtures for Lorentz-cycled new generation air-conditioning equipment. Equipment has been completed for simultaneous measurement of density and vapor-liquid equilibrium property, accurate measurement of latent heat of vaporization, and accurate measurement of specific heat at constant pressure in liquid phase. Final adjustment and preliminary measurements are currently conducted. Through analytical investigation using actually measured data of thermodynamic properties of HFC refrigerant mixtures, five state equations were obtained, i.e., modified Peng-Robinson state equation which can reproduce the vapor-liquid equilibrium property of refrigerant mixtures, modified Patel-Teja state equation, Helmholtz function type state equation which is applicable in the whole fluid region of refrigerant mixtures, and so on. An evaluation test equipment has been fabricated as a trial for Lorentz-cycled air-conditioning equipments using HFC refrigerant mixtures, and demonstration test is conducted to confirm the validity. 9 refs., 5 figs.

  2. Photoionization and dissociative photoionization study of HFC-152a using synchrotron radiation

    International Nuclear Information System (INIS)

    Huang Chaoqun; Wei Lixia; Yang Bin; Yang Rui; Wang Sisheng; Shan Xiaobin; Qi Fei; Zhang Yunwu; Sheng Liusi; Hao Liqing; Zhou Shikang; Wang Zhenya

    2006-01-01

    Photoionization and dissociative photoionization of HFC-152a have been studied using synchrotron radiation and a reflection time-of-flight mass spectrometry (RTOF-MS). The ionization energy of parent molecule (11.94 ± 0.04 eV) and appearance potentials of various fragment ions have been determined by measuring their photoionization efficiency curves. Energies, symmetry point groups and ground electronic states of neutrals and cations of parent and its fragments have been calculated using GAUSSIAN-03 program with the G3 method. According to the theoretical and experimental results, some dissociation channels and their dissociation energies of CH 3 CHF 2 + have been analyzed. (authors)

  3. Preparation of HfC single crystals by a floating zone technique

    International Nuclear Information System (INIS)

    Otani, S.; Tanaka, T.

    1981-01-01

    HfC single crystals have been prepared using a floating zone technique by controlling the compositions of the initial molten zone and the feed rod. The obtained crystal rods were 6 cm long and 0.9 cm in diameter. The various parts of the crystal rods have nearly constant compositions (C/Hf(ZR) = 0.956-0.977), and do not contain any free carbon. The impurities in the crystal, evaporation product, and starting material were examined by fluorescence X-ray spectroscopy. The refining effect due to evaporation was discussed. (orig.)

  4. HFC404A vaporisation inside a Brazed Plate Heat Exchanger (BPHE): Comparison with the possible long-term low GWP substitutes HC290 (Propane) and HC1270 (Propylene)

    International Nuclear Information System (INIS)

    Longo, Giovanni A.; Mancin, Simone; Righetti, Giulia; Zilio, Claudio

    2016-01-01

    Highlights: • This paper investigates HFC404A vaporisation inside a BPHE. • HC290 and HC1270 exhibit heat transfer coefficients similar to HFC404A. • HC290 and HC1270 exhibit frictional pressure drops higher than HFC404A. • The experimental measurements are complemented with an IR thermography analysis. - Abstract: This paper presents the heat transfer coefficients and the pressure drops measured during HFC404A vaporisation inside a commercial BPHE and the comparison of this data with previous measurements carried out during HC290 (Propane) and HC1270 (Propylene) vaporisation inside the same BPHE and similar operating condition in order to assess the capability of HydroCarbon refrigerants as long-term low GWP substitutes for HFC404A in commercial and industrial refrigeration. Propane and Propylene exhibit boiling heat transfer coefficient very similar and frictional pressure drops higher than to those of HFC404A, therefore, taking into account also their good thermodynamic properties, they seems to be very promising as long-term low GWP substitutes for HFC404A. The HFC404A boiling heat transfer coefficients were also compared with a new model for refrigerant boiling inside BPHE (Longo et al., 2015): the mean absolute percentage deviation between calculated and experimental data is 6.0%. The heat transfer measurements were also complemented with an IR thermography analysis for a better understanding of refrigerant vaporisation heat transfer regime inside a BPHE.

  5. Experimental investigation of HFC407C/HC290/HC600a mixture in a window air conditioner

    International Nuclear Information System (INIS)

    Jabaraj, D.B.; Avinash, P.; Lal, D. Mohan; Renganarayan, S.

    2006-01-01

    HCFC22, one of the widely used refrigerants in window air conditioners must be phased out soon as per the Montreal protocol. Presently, HFC407C is considered as a potential drop in substitute for HCFC22, but retrofitting HCFC22 systems with HFC407C with polyol ester oil (POE) is a major issue as HFC407C is immiscible with mineral oil. The miscibility issue of HFC407C with mineral oil was overcome with the addition of a HC blend to it. The above technoeconomic feasibility issues to retrofit the existing HCFC22 systems with an ozone friendly refrigerant and retain the energy efficiency of the system are challenges in the air conditioning sector. In this present work, an experimental analysis has been conducted in a window air conditioner retrofitted with eco-friendly refrigerant mixtures of HFC407C/HC290/HC600a without changing the mineral oil. Its performance, as well as energy consumption, was compared with the conventional one. It is observed that the mixtures demand lengthening of the condenser in order to maintain the discharge pressure within acceptable limits. This also resulted in better heat transfer at the condenser. Therefore, in this study, the condenser tube length was increased by 19% to suit the mixtures as compared to HCFC22. Compared to HCFC22, the refrigeration capacity of the new mixture was 9.54-12.76% higher than that of HCFC22, while the actual COP was found to be 11.91-13.24% higher than that of HCFC22. The overall performance has proved that the HFC407C/HC blend refrigerant mixture could be an eco-friendly substitute to phase out HCFC22

  6. Viscosity Measurements and Correlations for 1,1,1,2-tetrafluoroethane (HFC-134a) up to 140 MPa

    DEFF Research Database (Denmark)

    Comuñas, M.J.P.; Baylaucq, A.; Cisneros, Sergio

    2003-01-01

    In spite of being one of the most studied refrigerants, large discrepancies in the experimental determination of the dynamic viscosity of 1, 1, 1,2-tetrafluoroethane (HFC-134a) prevail. Additionally, there is a need for supplementary high-pressure measurements that can help to derive sound general...... correlations for the viscosity of this compound. Hence, in this work new dynamic viscosity measurements for HFC-134a using a falling-body viscometer in the temperature range of 293.15-373.15 K and pressures up to 140 MPa are presented. This work high-pressure data in combination with already published data...

  7. Action mechanism of hydrogen gas on deposition of HfC coating using HfCl{sub 4}-CH{sub 4}-H{sub 2}-Ar system

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yalei, E-mail: yaleipm@csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083 (China); School of Metallurgy and Environment, Central South University, Changsha, 410083 (China); Li, Zehao [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083 (China); Xiong, Xiang, E-mail: xiongx@csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083 (China); Li, Xiaobin [School of Metallurgy and Environment, Central South University, Changsha, 410083 (China); Chen, Zhaoke; Sun, Wei [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083 (China)

    2016-12-30

    Highlights: • HfC coatings were deposited on C/C composites by LPCVD using HfCl4-CH4-H2-Ar system. • Action mechanism of H2 on structure and growth behavior of HfC coating was studied. • Increased H2 concentration leads to transformation in growth mechanism of coating. - Abstract: Hafnium carbide coatings were deposited on carbon/carbon composites by low pressure chemical vapor deposition using HfCl{sub 4}-CH{sub 4}-H{sub 2}-Ar system. The microstructure, mechanical and ablation resistance performance of HfC coatings deposited with various H{sub 2} concentrations were investigated. The effect of hydrogen gas on the deposition of HfC coating was also discussed. Results show that all of the deposited coatings are composed of single cubic HfC phase, the hydrogen gas acted as a crucial role in determining the preferred orientation, microstructure and growth behavior of HfC coatings. During the deposition process, the gas phase supersaturation of the reaction species can be controlled by adjusting the hydrogen gas concentration. When deposited with low hydrogen gas concentration, the coating growth was dominated by the nucleation of HfC, which results in the particle-stacked structure of HfC coating. Otherwise, the coating growth was dominated by the crystal growth at high hydrogen gas concentration, which leads to the column-arranged structure of HfC coating. Under the ablation environment, the coating C2 exhibits better configurational stability and ablation resistance. The coating structure has a significant influence on the mechanical and ablation resistance properties of HfC coating.

  8. Experimental evaluation of automotive air-conditioning using HFC-134a and HC-134a

    Science.gov (United States)

    Nasution, Henry; Zainudin, Muhammad Amir; Aziz, Azhar Abdul; Latiff, Zulkarnain Abdul; Perang, Mohd Rozi Mohd; Rahman, Abd Halim Abdul

    2012-06-01

    An experimental study to evaluate the energy consumption of an automotive air conditioning is presented. In this study, these refrigerants will be tested using the experimental rig which simulated the actual cars as a cabin complete with a cooling system component of the actual car that is as the blower, evaporator, condenser, radiators, electric motor, which acts as a vehicle engine, and then the electric motor will operate the compressor using a belt and pulley system, as well as to the alternator will recharge the battery. The compressor working with the fluids HFC-134a and HC-134a and has been tested varying the speed in the range 1000, 1500, 2000 and 2500 rpm. The measurements taken during the one hour experimental periods at 2-minutes interval times for temperature setpoint of 20°C with internal heat loads 0, 500, 700 and 1000 W. The final results of this study show an overall better energy consumption of the HFC-134a compared with the HC-134a.

  9. A molecular orbital study on the oxidative decomposition of HFC-32

    International Nuclear Information System (INIS)

    Mochizuki, Yuji

    1999-03-01

    A series of ab initio molecular orbital calculations, in which Hartree-Fock, second-order Moeller-Plesset perturbation, density functional (B3LYP and BHandHLYP) levels of theory were used, was performed on the elementary reactions related to the oxidative decomposition of HFC-32 (CH 2 F 2 ) by hydroxyl (OH) radicals in a supercritical water condition (so-called SCWO). The whole process is written as CH 2 F 2 + 4OH → CO 2 + 2H 2 O + 2HF and consists of (1) H abstraction by OH to form H 2 O, (2) OH coupling to C-center, and (3) HF leaving to form C=O bond. Molecular geometries were optimized at each level of theory. The HF leaving was found to be the rate-determining step, but its barrier height was lowered by the reactive solvation with an extra H 2 O. Calculations implied that the SCWO of HFC-32 can proceed efficiently. (author)

  10. US emissions of HFC-134a derived for 2008-2012 from an extensive flask-air sampling network

    NARCIS (Netherlands)

    Hu, Lei; Montzka, Stephen A.; Miller, John B.; Andrews, Aryln E.; Lehman, Scott J.; Miller, Benjamin R.; Thoning, Kirk; Sweeney, Colm; Chen, Huilin; Godwin, David S.; Masarie, Kenneth; Bruhwiler, Lori; Fischer, Marc L.; Biraud, Sebastien C.; Torn, Margaret S.; Mountain, Marikate; Nehrkorn, Thomas; Eluszkiewicz, Janusz; Miller, Scot; Draxler, Roland R.; Stein, Ariel F.; Hall, Bradley D.; Elkins, James W.; Tans, Pieter P.

    2015-01-01

    U.S. national and regional emissions of HFC-134a are derived for 2008-2012 based on atmospheric observations from ground and aircraft sites across the U.S. and a newly developed regional inverse model. Synthetic data experiments were first conducted to optimize the model assimilation design and to

  11. A fundamental equation of state for 1,1-difluoroethane (HFC-152a)

    Science.gov (United States)

    Tillner-Roth, R.

    1995-01-01

    A fundamental equation ofstale for HFC-152a ( 1,1-dilluorocthane) is presented covering temperatures between the triple-point temperature ( 154.56 K) and 435 K for pressures up to 311 M Pa. The equation is based on reliable ( p, g, T) data in the range mentioned above. These are generally represented within ±0.1 % of density. Furthermore. experimental values of the vapor pressure, the saturated liquid density, and some isobaric heat capacities in the liquid were included during the correlation process. The new equation of state is compared with experimental data and also with the equation of state developed by Tamatsu et al. Differences between the two equations of state generally result from using different experimental input data. It is shown that the new equation of state allows an accurate calculation of various thermodynamic properties for most technical applications.

  12. Performance Analysis of a Centrifugal Compressor for HFC-134a with aviation of Diffuser Vane Angle

    International Nuclear Information System (INIS)

    Park, Han Young; Chung, Jin Taek; Shin, You Hwan; Lee, Yoon Pyo; Kim, Kwang Ho; Cho, Yong Hun; Kim, Jong Seong

    2007-01-01

    Numerical simulation on the two-stage centrifugal compressor with Low Solidity Vaned Diffuser (LSVD) for HFC-134a turbo-chiller was performed using a commercial code. The comparative study with experimental results from other compressor was also investigated to testify the simulation schemes. The numerical analysis was separately simulated for each stage of the compressor and the effect of impeller-diffuser flow interaction was considered. Setting angle of the diffuser vane changed in the range of 15 .deg. and the effects on its variation were discussed in detail including the flow analysis in the passage of the compressor. The vane setting angle obtained from the preliminary design was slightly adjusted to the optimal value by the performance enhancement in terms of pressure recovery and flow characteristics

  13. Inventory and mitigation opportunities for HFC-134a emissions from nonprofessional automotive service

    Science.gov (United States)

    Zhan, Tao; Potts, Winston; Collins, John F.; Austin, Jeff

    2014-12-01

    Many vehicle owners in the United States recharge their vehicles' air conditioning systems with small containers of hydrofluorocarbon-134a (HFC-134a, CH2FCF3), at a frequency estimated to be once every year on average. Such nonprofessional service produces immediate emissions of this potent greenhouse gas during service and from the residual heel in partially used containers. The nonprofessional operations are also associated with increased delayed refrigerant emissions that occur because owners are less likely to repair leaks than professional technicians. In California, an estimated 1.3 million nonprofessional service operations performed each year generate 0.27 ± 0.07 million metric ton CO2 equivalent (MMTCO2e) of immediate emissions and 0.54 ± 0.08 MMTCO2e of delayed emissions, using a Global Warming Potential of 1300 for HFC-134a. The immediate emissions can be largely mitigated by a regulation that requires self-sealing valves and improved labeling instructions on the containers, a deposit-return-recycling program for the containers, and a consumer education program. If 95% of the used containers were to be returned by consumers for recycling of the container heel, the annual immediate emissions would be reduced by 0.26 ± 0.07 MMTCO2e. In the United States, an estimated 24 million nonprofessional service operations are performed each year, generating 5.1 ± 1.4 MMTCO2e of immediate emissions and 10.4 ± 1.5 MMTCO2e of delayed emissions. Mitigation measures equivalent to the California regulation would reduce nationwide immediate emissions by 4.9 ± 1.4 MMTCO2e, if 95% of the used cans were returned for recycling. These business-as-usual emissions and mitigation potentials are projected to stay approximately constant until around 2022, and remain at significant levels into the 2030s.

  14. MAKING VISIBLE THE INVISIBLE HAND OF NEOLIBERAL THOUGHT IN COSTA RICA: BIRTH AND TRAJECTORY OF THE NATIONAL ASSOCIATION OF ECONOMIC DEVELOPMENT (ANFE: 1958-1975

    Directory of Open Access Journals (Sweden)

    Jorge Marchena Sanabria

    2011-12-01

    Full Text Available The following article deals with Costa Rican intellectual and political history, particularly focusedon the National Association of Economic Development (AsociaciónNacional de FomentoEconómico-ANFE.This organization was created in 1958 with the purpose of studying and transforming the Costa Rican State in the second half of the twentieth century and proposing policies aimed at developing the economy, making it more consistent with the free-market and reduction of state interventionliberal models.The article is part of a more extensive investigation, for which a wider corpus of documents was analyzed than the one cited here.

  15. Observations of 1,1-difluoroethane (HFC-152a) at AGAGE and SOGE monitoring stations in 1994-2004 and derived global and regional emission estimates

    Science.gov (United States)

    Greally, B. R.; Manning, A. J.; Reimann, S.; McCulloch, A.; Huang, J.; Dunse, B. L.; Simmonds, P. G.; Prinn, R. G.; Fraser, P. J.; Cunnold, D. M.; O'Doherty, S.; Porter, L. W.; Stemmler, K.; Vollmer, M. K.; Lunder, C. R.; Schmidbauer, N.; Hermansen, O.; Arduini, J.; Salameh, P. K.; Krummel, P. B.; Wang, R. H. J.; Folini, D.; Weiss, R. F.; Maione, M.; Nickless, G.; Stordal, F.; Derwent, R. G.

    2007-03-01

    Ground-based in situ measurements of 1,1-difluoroethane (HFC-152a, CH3CHF2) which is regulated under the Kyoto Protocol are reported under the auspices of the AGAGE (Advanced Global Atmospheric Gases Experiment) and SOGE (System of Observation of halogenated Greenhouse gases in Europe) programs. Observations of HFC-152a at five locations (four European and one Australian) over a 10 year period were recorded. The annual average growth rate of HFC-152a in the midlatitude Northern Hemisphere has risen from 0.11 ppt/yr to 0.6 ppt/yr from 1994 to 2004. The Southern Hemisphere annual average growth rate has risen from 0.09 ppt/yr to 0.4 ppt/yr from 1998 to 2004. The 2004 average mixing ratio for HFC-152a was 5.0 ppt and 1.8 ppt in the Northern and Southern hemispheres, respectively. The annual cycle observed for this species in both hemispheres is approximately consistent with measured annual cycles at the same locations in other gases which are destroyed by OH. Yearly global emissions of HFC-152a from 1994 to 2004 are derived using the global mean HFC-152a observations and a 12-box 2-D model. The global emission of HFC-152a has risen from 7 Kt/yr to 28 Kt/yr from 1995 to 2004. On the basis of observations of above-baseline elevations in the HFC-152a record and a consumption model, regional emission estimates for Europe and Australia are calculated, indicating accelerating emissions from Europe since 2000. The overall European emission in 2004 ranges from 1.5 to 4.0 Kt/year, 5-15% of global emissions for 1,1-difluoroethane, while the Australian contribution is negligible at 5-10 tonnes/year, <0.05% of global emissions.

  16. FY1995 study of thermodynamic properties of HFC refrigerant mixtures for Lorentz-cycled new generation air-conditioning equipments; 1995 nendo Lorentz cycle ka shinsedai kucho kikiyo HFC kei kongo reibai no netsurikigaku seishitsu ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    A hydrochlorofluorocarbon (HCFC) refrigerant, R-22, is currently being used almost exclusively as a refrigerant for conventional air-conditioning equipments. Since HCFCs are expected to be banned shortly, it is considered a crucial issue to support R and D of the air-conditioning system Lorentz-cycled with hydrofluorocarbon (HFC) refrigerants mixtures. In the present research project, therefore, it is aimed to reveal some of the essential thermodynamic properties of HFC refrigerant mixtures systematically. On the basis of a series of achievements for the last several years by the present research coordinator and his group regarding thermodynamic properties of single-component and blended HFC refrigerants, we have conducted following three major research programs rather systematically on which no challenges have ever been reported worldwide. Throughout a series of experimental as well as analytical researches performed so as to meet the objectives mentioned above, some novel knowledge and valuable outcomes could be obtained in the present study. (1) Precise measurements of vapor-liquid equilibrium properties with simultaneous determination of densities, latent heats of vaporization, and isobaric specific heat capacities in liquid phase. (2) Analytical studies to establish thermodynamic property modeling. (3) Feasibility study of evaluating the Lorentz-cycled performance. (NEDO)

  17. Isosteric heats of adsorption extracted from experiments of ethanol and HFC 134a on carbon based adsorbents

    Energy Technology Data Exchange (ETDEWEB)

    El-Sharkawy, Ibrahim I.; Saha, Bidyut B.; Koyama, Shigeru [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-koen 6-1, Kasuga-shi, Fukuoka 816-8580 (Japan); Srinivasan, Kandadai [School of Engineering and Logistics, Charles Darwin University, Darwin NT 0909 (Australia)

    2007-03-15

    The purpose of this paper is to provide empirical correlations for isosteric heats of adsorption on carbon based adsorbents for two refrigerants namely ethanol and HFC 134a. A non-dimensional correlation which partitions the contributions of the concentration and temperature dependence is proposed. The correlation is tested out against data obtained from experimental isotherms of ethanol adsorption on activated carbon fibers [ACF (A-20) and ACF (A-15)] and HFC 134a on two specimens of activated carbon powders and one specimen of carbon granules. It is expected that the suggested correlation will be useful for designers of adsorption chillers where indenting heat inventories fulcrums on the magnitude of isosteric heat of adsorption. (author)

  18. Final Project Closeout Report for Sprint Hydrogen Fuel Cell (HFC) Deployment Project in California, Gulf Coast and Eastern Seaboard Markets

    Energy Technology Data Exchange (ETDEWEB)

    Kenny, Kevin [Sprint, Reston, VA (United States); Bradley, Dwayne [Burns & McDonnell, Kansas City, MO (United States)

    2015-09-01

    Sprint is one of the telecommunications industry leaders in the deployment of hydrogen fuel cell (HFC) systems to provide backup power for their mission critical wireless network facilities. With several hundred fuel cells commissioned in California, states in the gulf coast region, and along the upper eastern seaboard. A strong incentive for advancing the integration of fuel cells into the Sprint network came through the award of a Department of Energy (DOE) grant focused on Market Transformation activities for project (EE0000486). This grant was funded by the 2009 American Recovery and Reinvestment Act (ARRA). The funding provided by DOE ($7.295M) was allocated to support the installation of 260 new HFC systems, equipped with an on-site refillable Medium Pressure Hydrogen Storage Solution (MPHSS), as well as for the conversion of 21 low pressure hydrogen systems to the MPHSS, in hopes of reducing barriers to market acceptance.

  19. Ticks infesting amphibians and reptiles in Pernambuco, Northeastern Brazil Carrapatos infestando anfíbios e répteis em Pernambuco, Nordeste do Brasil

    Directory of Open Access Journals (Sweden)

    Filipe Dantas-Torres

    2008-12-01

    Full Text Available Ticks infesting amphibians and reptiles in the State of Pernambuco are reviewed, based on the current literature and new collections recently carried out by the authors. To date, three tick species have been found on amphibians and reptiles in Pernambuco. Amblyomma fuscum appears to be exclusively associated with Boa constrictor, its type host. Amblyomma rotundatum has a relatively low host-specificity, being found on toads, snakes, and iguana. Amblyomma dissimile has been found on a lizard and also small mammals (i.e., rodents and marsupials. New tick-host associations and locality records are given.Os carrapatos encontrados infestando anfíbios e répteis no Estado de Pernambuco são revisados com base na literatura atual e em novas coletas realizadas recentemente pelos autores. Até o momento, três espécies de carrapatos foram encontradas sobre anfíbios e répteis em Pernambuco. Amblyomma fuscum parece estar exclusivamente associado à Boa constrictor, seu hospedeiro-tipo. Amblyomma rotundatum tem uma especificidade parasitária relativamente baixa, sendo encontrado em sapos, serpentes e iguana. Amblyomma dissimile já foi encontrado sobre um lagarto e também sobre pequenos mamíferos (isto é, roedores e marsupiais. Novas associações carrapato-hospedeiro e novos registros de localidades são apresentados.

  20. Recent increases in the atmospheric growth rate and emissions of HFC-23 (CHF3 and the link to HCFC-22 (CHClF2 production

    Directory of Open Access Journals (Sweden)

    P. G. Simmonds

    2018-03-01

    Full Text Available High frequency measurements of trifluoromethane (HFC-23, CHF3, a potent hydrofluorocarbon greenhouse gas, largely emitted to the atmosphere as a by-product of the production of the hydrochlorofluorocarbon HCFC-22 (CHClF2, at five core stations of the Advanced Global Atmospheric Gases Experiment (AGAGE network, combined with measurements on firn air, old Northern Hemisphere air samples and Cape Grim Air Archive (CGAA air samples, are used to explore the current and historic changes in the atmospheric abundance of HFC-23. These measurements are used in combination with the AGAGE 2-D atmospheric 12-box model and a Bayesian inversion methodology to determine model atmospheric mole fractions and the history of global HFC-23 emissions. The global modelled annual mole fraction of HFC-23 in the background atmosphere was 28.9 ± 0.6 pmol mol−1 at the end of 2016, representing a 28 % increase from 22.6 ± 0.4 pmol mol−1 in 2009. Over the same time frame, the modelled mole fraction of HCFC-22 increased by 19 % from 199 ± 2 to 237 ± 2 pmol mol−1. However, unlike HFC-23, the annual average HCFC-22 growth rate slowed from 2009 to 2016 at an annual average rate of −0.5 pmol mol−1 yr−2. This slowing atmospheric growth is consistent with HCFC-22 moving from dispersive (high fractional emissions to feedstock (low fractional emissions uses, with HFC-23 emissions remaining as a consequence of incomplete mitigation from all HCFC-22 production.Our results demonstrate that, following a minimum in HFC-23 global emissions in 2009 of 9.6 ± 0.6, emissions increased to a maximum in 2014 of 14.5 ± 0.6 Gg yr−1 and then declined to 12.7 ± 0.6 Gg yr−1 (157 Mt CO2 eq. yr−1 in 2016. The 2009 emissions minimum is consistent with estimates based on national reports and is likely a response to the implementation of the Clean Development Mechanism (CDM to mitigate HFC-23 emissions by

  1. Recent increases in the atmospheric growth rate and emissions of HFC-23 (CHF3) and the link to HCFC-22 (CHClF2) production

    Science.gov (United States)

    Simmonds, Peter G.; Rigby, Matthew; McCulloch, Archie; Vollmer, Martin K.; Henne, Stephan; Mühle, Jens; O'Doherty, Simon; Manning, Alistair J.; Krummel, Paul B.; Fraser, Paul J.; Young, Dickon; Weiss, Ray F.; Salameh, Peter K.; Harth, Christina M.; Reimann, Stefan; Trudinger, Cathy M.; Steele, L. Paul; Wang, Ray H. J.; Ivy, Diane J.; Prinn, Ronald G.; Mitrevski, Blagoj; Etheridge, David M.

    2018-03-01

    High frequency measurements of trifluoromethane (HFC-23, CHF3), a potent hydrofluorocarbon greenhouse gas, largely emitted to the atmosphere as a by-product of the production of the hydrochlorofluorocarbon HCFC-22 (CHClF2), at five core stations of the Advanced Global Atmospheric Gases Experiment (AGAGE) network, combined with measurements on firn air, old Northern Hemisphere air samples and Cape Grim Air Archive (CGAA) air samples, are used to explore the current and historic changes in the atmospheric abundance of HFC-23. These measurements are used in combination with the AGAGE 2-D atmospheric 12-box model and a Bayesian inversion methodology to determine model atmospheric mole fractions and the history of global HFC-23 emissions. The global modelled annual mole fraction of HFC-23 in the background atmosphere was 28.9 ± 0.6 pmol mol-1 at the end of 2016, representing a 28 % increase from 22.6 ± 0.4 pmol mol-1 in 2009. Over the same time frame, the modelled mole fraction of HCFC-22 increased by 19 % from 199 ± 2 to 237 ± 2 pmol mol-1. However, unlike HFC-23, the annual average HCFC-22 growth rate slowed from 2009 to 2016 at an annual average rate of -0.5 pmol mol-1 yr-2. This slowing atmospheric growth is consistent with HCFC-22 moving from dispersive (high fractional emissions) to feedstock (low fractional emissions) uses, with HFC-23 emissions remaining as a consequence of incomplete mitigation from all HCFC-22 production.Our results demonstrate that, following a minimum in HFC-23 global emissions in 2009 of 9.6 ± 0.6, emissions increased to a maximum in 2014 of 14.5 ± 0.6 Gg yr-1 and then declined to 12.7 ± 0.6 Gg yr-1 (157 Mt CO2 eq. yr-1) in 2016. The 2009 emissions minimum is consistent with estimates based on national reports and is likely a response to the implementation of the Clean Development Mechanism (CDM) to mitigate HFC-23 emissions by incineration in developing (non-Annex 1) countries under the Kyoto Protocol. Our derived cumulative

  2. (Vapour + liquid) equilibria of the {1,1-difluoroethane (HFC-152a) + n-butane (HC-600)} system

    International Nuclear Information System (INIS)

    Im, Jihoon; Lee, Gangwon; Lee, Yong-Jin; Kim, Hwayong

    2007-01-01

    Binary (vapour + liquid) equilibrium data were obtained for the {1,1-difluoroethane (HFC-152a) + n-butane (HC-600)} system at temperatures from 313.15 K to 363.15 K. These experiments were carried out with a circulating-type apparatus with on-line gas chromatography. The experimental data were correlated well by Peng-Robinson equation of state using the Wong-Sandler mixing rules. This system shows positive azeotropic phase behaviour

  3. Measurements of HFC-134a and HCFC-22 in groundwater and unsaturated-zone air: implications for HFCs and HCFCs as dating tracers

    Science.gov (United States)

    Haase, Karl B.; Busenberg, Eurybiades; Plummer, Niel; Casile, Gerolamo; Sanford, Ward E.

    2014-01-01

    A new analytical method using gas chromatography with an atomic emission detector (GC–AED) was developed for measurement of ambient concentrations of hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) in soil, air, and groundwater, with the goal of determining their utility as groundwater age tracers. The analytical detection limits of HCFC-22 (difluorochloromethane, CHClF2) and HFC-134a (1,2,2,2-tetrafluoroethane, C2H2F4) in 1 L groundwater samples are 4.3 × 10− 1 and 2.1 × 10− 1 pmol kg− 1, respectively, corresponding to equilibrium gas-phase mixing ratios of approximately 5–6 parts per trillion by volume (pptv). Under optimal conditions, post-1960 (HCFC-22) and post-1995 (HFC-134a) recharge could be identified using these tracers in stable, unmixed groundwater samples. Ambient concentrations of HCFC-22 and HFC-134a were measured in 50 groundwater samples from 27 locations in northern and western parts of Virginia, Tennessee, and North Carolina (USA), and 3 unsaturated-zone profiles were collected in northern Virginia. Mixing ratios of both HCFC-22 and HFC-134a decrease with depth in unsaturated-zone gas profiles with an accompanying increase in CO2 and loss of O2. Apparently, ambient concentrations of HCFC-22 and HFC-134a are readily consumed by methanotrophic bacteria under aerobic conditions in the unsaturated zone. The results of this study indicate that soils are a sink for these two greenhouse gases. These observations contradict the previously reported results from microcosm experiments that found that degradation was limited above-ambient HFC-134a. The groundwater HFC and HCFC concentrations were compared with concentrations of chlorofluorocarbons (CFCs, CFC-11, CFC-12, CFC-113) and sulfur hexafluoride (SF6). Nearly all samples had measured HCFC-22 or HFC-134a that were below concentrations predicted by the CFCs and SF6, with many samples showing a complete loss of HCFC-22 and HFC-134a. This study indicates that HCFC-22 and HFC-134

  4. Choked flow mechanism of HFC-134a flowing through short-tube orifices

    Energy Technology Data Exchange (ETDEWEB)

    Nilpueng, Kitti; Wongwises, Somchai [Fluid Mechanics, Thermal Engineering and Multiphase Flow Research Lab (FUTURE), Department of Mechanical Engineering, King Mongkut' s University of Technology Thonburi, Bangmod, Bangkok (Thailand)

    2011-02-15

    This paper is a continuation of the author's previous work. New experimental data on the occurrence of choked flow phenomenon and mass flow rate of HFC-134a inside short-tube orifices under choked flow condition are presented. Short-tube orifices diameters ranging from 0.406 mm to 0.686 mm with lengths ranging from 1 mm to 3 mm which can be applied to a miniature vapour-compression refrigeration system are examined. The experimental results indicated that the occurrence of choked flow phenomena inside short-tube orifices is different from that obtained from short-tube orifice diameters of greater than 1 mm, which are typically used in air-conditioner. The beginning of choked flow is dependent on the downstream pressure, degree of subcooling, and length-to-diameter ratio. Under choked flow condition, the mass flow rate is greatly varied with the short-tube orifice dimension, but it is slightly affected by the operating conditions. A correlation of mass flow rate through short-tube orifices is proposed in terms of the dimensionless parameters. The predicted results show good agreement with experimental data with a mean deviation of 4.69%. (author) transfer coefficient was also proposed. (author)

  5. Uptake and disposition of 1,1-difluoroethane (HFC-152a) in humans.

    Science.gov (United States)

    Ernstgård, Lena; Sjögren, Bengt; Dekant, Wolfgang; Schmidt, Tobias; Johanson, Gunnar

    2012-02-25

    The aim of this study was to determine the toxicokinetics of inhaled 1,1-difluoroethane (HFC-152a) in humans. Healthy volunteers were exposed to 0, 200 or 1000 ppm 1,1-difluoroethane for 2h at light exercise in an exposure chamber. Capillary blood, urine and exhaled air were sampled up to 22 h post-exposure and analyzed for 1,1-difluoroethane. Fluoride and other potential metabolites were analyzed in urine. Symptoms of irritation and central nervous system effects were rated and inflammatory markers were analyzed in blood. Within a few minutes of exposure to 200 and 1000 ppm, 1,1-difluoroethane increased rapidly in blood and reached average levels of 7.4 and 34.3 μM, respectively. The post-exposure decreases in blood were fast and parallel to those in exhaled air. The observed time courses in blood and breath agreed well with those obtained with the PBPK model. The PBPK simulations indicate a net uptake during exposure to 1000 ppm of 6.6 mmol (6.7%) which corresponds to the amount exhaled post-exposure. About 20 μmol excess fluoride (0.013% of inhaled 1,1-difluoroethane on a molar basis) was excreted in urine after exposure to 1000 ppm, compared to control. No fluorine-containing metabolites were detected in urine. Symptom ratings and changes in inflammatory markers revealed no exposure-related effects. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  6. Investigation of two-phase thermosyphon performance filled with modern HFC refrigerants

    Science.gov (United States)

    Gorecki, Grzegorz

    2018-02-01

    Two-phase closed thermosyphons (TPCTs) are widely utilized as heat exchanger elements in waste heat recovery systems and as passive heating/cooling devices. They are popular because of their high thermal conductivity, simple construction and reliability. Previous researches indicate that refrigerants are performing better than typical TPCT working fluids like deionized water or alcohols in the low temperature range. In the present study three HFC (Hydrofluorocarbons) refrigerants were tested: R134a, R404A and R407C. The total length of the investigated TPCT is 550 mm with equal length (245 mm) condenser and evaporator sections. Its outer diameter is 22 mm with 1 mm wall thickness. The evaporator section was heated by hot water with varying inlet temperature by 5 K step in the range of 288 K - 323 K. The condenser was cooled by cold water with inlet temperature kept at a constant value of 283 K. It was found that using R134a and R404A as working fluids heat transfer rates are the highest. For both refrigerants 10% is optimal filling ratio. They can be utilized interchangeably because the differences between their throughputs are within uncertainty bands. R407C performance was 50% lower. Other disadvantages of using this refrigerant are relatively high working pressures and higher optimal filling ratio (30%).

  7. Indirect phase transition of TiC, ZrC, and HfC crystal structures

    Energy Technology Data Exchange (ETDEWEB)

    Abavare, Eric K.K.; Dodoo, Samuel N.A. [Department of Physics, Kwame Nkrumah University of Science and Technology, Kumasi (Ghana); Uchida, Kazuyuki; Oshiyama, Atsushi [Department of Applied Physics, The University of Tokyo, Hongo, Tokyo (Japan); Nkurumah-Buandoh, George K.; Yaya, Abu [Department of Physics, University of Ghana, Legon (Ghana)

    2016-06-15

    We have performed first-principles calculations to analyze the electronic structures, static, and dynamical structural stabilities of the pressure-induced phase transformation of refractory compounds (transition-metal carbides) from NaCl-type (B1) to CsCl-type (B2) via zinc-blende phase using the plane-wave pseudopotential approach in the framework of the generalized gradient approximation (GGA) for the exchange and correlation functional. The ground-state properties, equilibrium lattice constant, bulk moduli, and band structures are determined for the stoichiometry of the compounds and compared with known experimental and theoretical values. We find that the phase-transition pressure for the indirect phase transition from B1→B2 via zinc-blende structure is about 17-fold for TiC, 12-fold for both ZrC and HfC, respectively, when compared with the direct phase transition. Calculated phonon instability exists for the CsCl-B2 phase, which can prevent the structures from forming and contrary to the zinc-blende and the NaCl-B1 phases. The band dispersion and electronic density of states for B1 and B2 crystal phases were explored and found to indicate metallic character in contrast with the zinc-blende phase, which has a pseudogap opening in the bandgap region suggesting a semiconducting property and also a frequency gap in the phonon spectrum. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Anfípodos hiperídeos (Crustacea: Peracarida del Parque Nacional Isla del Coco, Costa Rica, Pacífico Tropical Oriental

    Directory of Open Access Journals (Sweden)

    Rebeca Gasca

    2012-11-01

    Full Text Available Los anfípodos hiperídeos son uno de los grupos de crustáceos pelágicos más frecuentemente encontrados y están entre los más diversos del zooplancton marino. Para determinar la composición de especies de anfípodos hipéridos que habitan las aguas alrededor del Parque Nacional Isla del Coco, Costa Rica, se analizaron 12 muestras de zooplancton. Estas fueron recolectadas mediante arrastres verticales y horizontales con una red de plancton con mallas de 200 y 500 micras y 49cm de diámetro en la boca. Se encontró un total de 22 especies pertenecientes a 17 géneros y 12 familias. Se presenta el listado faunístico de este grupo junto con datos acerca de su taxonomía, su distribución en el área de estudio y su distribución general. La mayor parte de las especies registradas en esta zona han sido reportadas en estudios previos referentes a la región del Pacífico Tropical Oriental y en particular en aguas oceánicas de Costa Rica. Encontramos ocho especies que representan nuevos registros para aguas del Pacífico costarricense, lo que incrementa en un 26% (a 38 el número de especies de hipéridos conocidos en Costa Rica. Las especies más frecuentes fueron Lestrigonus shoemakeri, L. bengalensis, Hyperioides sibaginis y Phronimosis spinifera. Se espera que muestreos adicionales tanto de aguas superficiales como profundas expandan el conocimiento de la diversidad del grupo en esta área protegida.

  9. Atmospheric observations for quantifying emissions of point-source synthetic greenhouse gases (CF4, NF3 and HFC-23)

    Science.gov (United States)

    Arnold, Tim; Manning, Alistair J.; Li, Shanlan; Kim, Jooil; Park, Sunyoung; Fraser, Paul J.; Mitrevski, Blagoj; Steele, L. Paul; Krummel, Paul B.; Mühle, Jens; Weiss, Ray F.

    2016-04-01

    The fluorinated species carbon tetrafluoride (CF4; PFC-14), nitrogen trifluoride (NF3) and trifluoromethane (CHF3; HFC-23) are potent greenhouse gases with 100-year global warming potentials of 6,630, 16,100 and 12,400, respectively. Unlike the majority of CFC-replacement compounds that are emitted from fugitive and mobile emission sources, these gases are largely emitted from large single point sources - semiconductor manufacturing facilities (all three), aluminium smelting plants (CF4) and chlorodifluoromethane factories (HFC-23). In this work we show the potential for atmospheric measurements to understand regional sources of these gases and to highlight emission 'hotspots'. We target our analysis on measurements from two Advanced Global Atmospheric Gases Experiment (AGAGE) long term monitoring sites that are particularly sensitive to regional emissions of these gases: Gosan on Jeju Island in the Republic of Korea and Cape Grim on Tasmania in Australia. These sites measure CF4, NF3 and HFC-23 alongside a suite of greenhouse and stratospheric ozone depleting gases every two hours using automated in situ gas-chromatography mass-spectrometry instrumentation. We couple each measurement to an analysis of air history using the regional atmospheric transport model NAME (Numerical Atmospheric dispersion Modelling Environment) driven by 3D meteorology from the Met Office's Unified Model, and use a Bayesian inverse method (InTEM - Inversion Technique for Emission Modelling) to calculate yearly emission changes over a decade (2005-2015) at high spatial resolution. At present these gases make a small contribution to global radiative forcing, however, given that their impact could rise significantly and that point sources of such gases can be mitigated, atmospheric monitoring could be an important tool for aiding emissions reduction policy.

  10. HFO1234ze(E) And HFC134a Flow Boiling Inside a 4mm Horizontal Smooth Tube

    OpenAIRE

    Longo, Giovanni A.; Mancin, Simone; Righetti, Giulia; Zilio, Claudio

    2016-01-01

    Nowadays, the substitution of HFC134a with low GWP refrigerants is one of the most important challenge for refrigeration and air conditioning. The possible substitutes include natural refrigerants, such as HC600 (Butane) and HC600a (Isobutane), and also synthetic refrigerants, such as HFO1234yf and HFO1234ze(E). The HC refrigerants exhibit very low GWP, 3 and 4 HC600a and HC600 respectively, good thermodynamic and transport properties, and pressure and volumetric performance very similar to H...

  11. Substituting HCFC-22 for HFC-410A: an environmental impact trade-off between the ozone depletion and climate change regimes

    Science.gov (United States)

    Wang, Z.; Fang, X.; Zhang, J.

    2015-12-01

    After the phase-out of hydrochlorofluorocarbons (HCFCs) as ozone-depleting substances pursuant to the requirements of the Montreal Protocol, hydrofluorocarbons (HFCs) are worldwide used as substitutes although the bulk of them are potent greenhouse gases (GHGs). Therefore, the alternation may bring side effect on global climate change. The trade-off of its environmental impacts between the ozone depletion and climate change regimes necessitates a quantification of the past and future consumption and emissions of both the original HCFCs and their alternative HFCs. Now a dilemma arise in China's RAC industry that HCFC-22, which has an ozone-depleting potential (ODP) of 0.055, has been replaced by HFC-410A, which is a blended potent GHG from respective 50% HFC-32 and HFC-125 with a global warming potential (GWP) of 1923.5. Here, we present our results of estimates of consumption and emissions of HCFC-22 and HFC-410A from 1994 to 2050. Historic emissions of HCFC-22 contributed to global total HCFCs by 4.0% (3.0%-5.6%) ODP-weighted. Projection under a baseline scenario shows future accumulative emissions of HFC-410A make up 5.9%-11.0% of global GWP-weighted HFCs emissions, and its annual contribution to national overall CO2 emissions can be 5.5% in 2050. This makes HCFC-22 and HFC-410A emissions of significant importance in ozone depletion and climate change regimes. Two mitigation scenarios were set to assess the mitigation performance under the North America Proposal and an accelerated schedule. In practice of international environmental agreement, "alternative to alternative" should be developed to avoid regrettable alternations.

  12. Achievement report on development of global warming prevention related technologies in fiscal 1998. Development of HFC-23 destruction technology; 1998 nendo chikyu ondanka boshi kanren gijutsu kaihatsu seika hokokusho. HFC-23 hakai gijutsu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-01-01

    HFC-23 is produced as a by-product during HCFC-22 manufacturing (produced at by-production rate of about 2%, whereas the reaction control has limitation in reducing the production). This is one of the substances subjected to the greenhouse effect gas reduction in the climate change framework treaty. This paper describes the achievements in 1998 on developing the HFC-23 destruction technology. High-temperature pyrolysis decomposes the substance into HF and CO2, which are given absorption treatment by water and alkali to make them harmless, and are recovered finally as calcium fluoride. An equipment having the treatment capability of 195 kg/h was constructed. Design was made on a facility capable of treating fluorine containing waste water at 3 t/h at maximum. Utilities consumed in a factory (industrial water, acids for neutralization, and alkali) are used effectively to identify the effect of reducing the treatment cost. Discussions were given from the safety aspect on facilities to prevent leakage of fluorine containing waste water being a harmful substance. Fabrication was executed on a full-size treatment testing equipment that can utilize the utilities in the factory effectively, and trial equipment operation was performed to arrange the system prepared toward the future tests and researches. (NEDO)

  13. Global and regional emissions estimates of 1,1-difluoroethane (HFC-152a, CH[subscript 3]CHF[subscript 2]) from in situ and air archive observations

    OpenAIRE

    Prinn, Ronald G.

    2015-01-01

    High frequency, in situ observations from 11 globally distributed sites for the period 1994–2014 and archived air measurements dating from 1978 onward have been used to determine the global growth rate of 1,1-difluoroethane (HFC-152a, CH[subscript 3]CHF[subscript 2]). These observations have been combined with a range of atmospheric transport models to derive global emission estimates in a top-down approach. HFC-152a is a greenhouse gas with a short atmospheric lifetime of about 1.5 years. Si...

  14. Emissions of CO2, CO, NOx, HC, PM, HFC-134a, N2O and CH4 from the global light duty vehicle fleet

    Directory of Open Access Journals (Sweden)

    Timothy J. Wallington

    2008-04-01

    Full Text Available Vehicles emit carbon dioxide (CO2, carbon monoxide (CO, nitrogen oxides (NOx, hydrocarbons (HC, particulate matter (PM, hydrofluorocarbon 134a (HFC-134a, methane (CH4, and nitrous oxide (N2O. An understanding of these emissions is needed in discussions of climate change and local air pollution issues. To facilitate such discussions an overview of past, present, and likely future emissions from light duty vehicles is presented. Emission control technologies have reduced the emissions of CO, VOCs, PM, HFC-134a, CH4, and N2O from modern vehicles to very low levels.

  15. FPGAs Emulate Microprocessors-A Successful Case for HFC NPP Digital I and C Upgrade

    International Nuclear Information System (INIS)

    Hsu, Allen; Crow, Ivan; Reese, Carl; Kim, Jong; Yang, Steve

    2014-01-01

    upgrade and that are consistent with US NRC regulatory requirements and industrial standards are presented. Then hardware and software requirements including interfaces for replacing the existing microprocessor-based controllers with FPGA-based components are described. Next, HFC FPGA design philosophy and architecture for emulating Intel 8085 Microprocessor is described. Finally, the experience, benefits, and recommendations using FPGAs to emulate microprocessors for applications in the nuclear safety digital I and C upgrades as well as for new builds are summarized and discussed

  16. FPGAs Emulate Microprocessors-A Successful Case for HFC NPP Digital I and C Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Allen; Crow, Ivan; Reese, Carl; Kim, Jong; Yang, Steve [Doosan HF Controls Corp, Carrollton (United States)

    2014-08-15

    upgrade and that are consistent with US NRC regulatory requirements and industrial standards are presented. Then hardware and software requirements including interfaces for replacing the existing microprocessor-based controllers with FPGA-based components are described. Next, HFC FPGA design philosophy and architecture for emulating Intel 8085 Microprocessor is described. Finally, the experience, benefits, and recommendations using FPGAs to emulate microprocessors for applications in the nuclear safety digital I and C upgrades as well as for new builds are summarized and discussed.

  17. An experimental investigation on the substitution of HFC134a with HFO1234YF in a domestic refrigerator

    International Nuclear Information System (INIS)

    Aprea, Ciro; Greco, Adriana; Maiorino, Angelo

    2016-01-01

    Highlights: • An experimental comparison between R134A and HFO1234YF is presented. • A domestic refrigerator made to work with R134A is analysed. • The annual energy consumptions of the device are reported. • The energy saving achievable after the drop-in is evaluated. - Abstract: The latest international regulations on the reduction of greenhouse gases are strongly redesigning the scenario of use of refrigerants, gradually eliminating the possibility of employing the HFCs. Among all sectors of refrigeration, one of the most affected by these restrictions is the domestic refrigeration. Although for it have been suggested some solutions, such as the construction of household refrigerator operating with the hydrocarbons, there remains the need to find a substitute for HFC134a. In particular, the substitution may involve both existing machines and already in operation, which cannot be loaded with hydrocarbons, and new devices. With the aim of finding a simple implementation solution, in the present work, it is reported an experimental investigation carried out on a domestic refrigerator designed and built to operate with HFC134a and for which a drop-in with HFO1234yf has been realised. The experimentation has been addressed so as to highlight the behaviour of the system as a result of the drop-in, with a particular interest in the energy performance variation. A slight energy saving has been recorded with HFO1234yf, and an improving of the cooling capacity has been noticed.

  18. Viscosity measurements and correlations of binary mixtures: 1,1,1,2-tetrafluoroethane (HFC-134a)+tetraethylene glycol dimethylether (TEGDME)

    DEFF Research Database (Denmark)

    Monsalvo, Matias Alfonso; Baylaucq, A.; Reghem, P.

    2005-01-01

    .15-373.15 K. The measurements have been carried out with a failing body viscometer for four molar fractions x(1) =(0.28, 0.44, 0.63 and 0.88). The density values of this system were interpolated from previous results obtained at the laboratory. All of the available viscosity data, including pure HFC-134a...

  19. [Roman Czaja. Die Anfänge preussischer Hansestädte im Lichte der historischen und archäologischen quellen : Danzig/Gdańsk, Elbing/Elbląg, Thorn/Toruń] / Dennis Hormuth

    Index Scriptorium Estoniae

    Hormuth, Dennis

    2013-01-01

    Arvustus : Roman Czaja. Die Anfänge preussischer Hansestädte im Lichte der historischen und archäologischen quellen : Danzig/Gdańsk, Elbing/Elbląg, Thorn/Toruń. In: Stadtgründung und Stadterweiterung. Beiträge von Archäologie und Stadtgeschichtsforschung. (=Beiträge zur Geschichte der Städte Mitteleuropas XXII). LInz, 2011. S. 59-74

  20. Global and regional emissions estimates of 1,1-difluoroethane (HFC-152a, CH3CHF2) from in situ and air archive observations

    Science.gov (United States)

    Simmonds, P. G.; Rigby, M.; Manning, A. J.; Lunt, M. F.; O'Doherty, S.; McCulloch, A.; Fraser, P. J.; Henne, S.; Vollmer, M. K.; Mühle, J.; Weiss, R. F.; Salameh, P. K.; Young, D.; Reimann, S.; Wenger, A.; Arnold, T.; Harth, C. M.; Krummel, P. B.; Steele, L. P.; Dunse, B. L.; Miller, B. R.; Lunder, C. R.; Hermansen, O.; Schmidbauer, N.; Saito, T.; Yokouchi, Y.; Park, S.; Li, S.; Yao, B.; Zhou, L. X.; Arduini, J.; Maione, M.; Wang, R. H. J.; Ivy, D.; Prinn, R. G.

    2016-01-01

    High frequency, in situ observations from 11 globally distributed sites for the period 1994-2014 and archived air measurements dating from 1978 onward have been used to determine the global growth rate of 1,1-difluoroethane (HFC-152a, CH3CHF2). These observations have been combined with a range of atmospheric transport models to derive global emission estimates in a top-down approach. HFC-152a is a greenhouse gas with a short atmospheric lifetime of about 1.5 years. Since it does not contain chlorine or bromine, HFC-152a makes no direct contribution to the destruction of stratospheric ozone and is therefore used as a substitute for the ozone depleting chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). The concentration of HFC-152a has grown substantially since the first direct measurements in 1994, reaching a maximum annual global growth rate of 0.84 ± 0.05 ppt yr-1 in 2006, implying a substantial increase in emissions up to 2006. However, since 2007, the annual rate of growth has slowed to 0.38 ± 0.04 ppt yr-1 in 2010 with a further decline to an annual average rate of growth in 2013-2014 of -0.06 ± 0.05 ppt yr-1. The annual average Northern Hemisphere (NH) mole fraction in 1994 was 1.2 ppt rising to an annual average mole fraction of 10.1 ppt in 2014. Average annual mole fractions in the Southern Hemisphere (SH) in 1998 and 2014 were 0.84 and 4.5 ppt, respectively. We estimate global emissions of HFC-152a have risen from 7.3 ± 5.6 Gg yr-1 in 1994 to a maximum of 54.4 ± 17.1 Gg yr-1 in 2011, declining to 52.5 ± 20.1 Gg yr-1 in 2014 or 7.2 ± 2.8 Tg-CO2 eq yr-1. Analysis of mole fraction enhancements above regional background atmospheric levels suggests substantial emissions from North America, Asia, and Europe. Global HFC emissions (so called "bottom up" emissions) reported by the United Nations Framework Convention on Climate Change (UNFCCC) are based on cumulative national emission data reported to the UNFCCC, which in turn are based on

  1. Oxidation behavior of TiC, ZrC, and HfC dispersed in oxide matrices

    International Nuclear Information System (INIS)

    Arun, R.; Subramanian, M.; Mehrotra, G.M.

    1990-01-01

    The oxidation behavior of hot pressed TiC-Al 2 O 3 , TiC-ZrO 2 , ZrC-ZrO 2 , and HfC-HfO 2 composites has been investigated at 1273 K. The oxidation of TiC, ZrC, and HfC in hot-pressed composites containing ZrO 2 and HfO 2 has been found to be extremely rapid. The kinetics of oxidation of TiC and a 90 wt% TiC-Al 2 O 3 composite appear to be faster compared to that of pure TiC. X-ray diffraction results for hot-pressed ZrC-HfO 2 and HfC-HfO 2 composites indicate partial stabilization of tetragonal ZrO 2 and HfO 2 phases in these composites

  2. Potential energy and dipole moment surfaces for HF@C60: Prediction of spectral and electric response properties

    Science.gov (United States)

    Kalugina, Yulia N.; Roy, Pierre-Nicholas

    2017-12-01

    We present a five-dimensional potential energy surface (PES) for the HF@C60 system computed at the DF-LMP2/cc-pVTZ level of theory. We also calculated a five-dimensional dipole moment surface (DMS) based on DFT(PBE0)/cc-pVTZ calculations. The HF and C60 molecules are considered rigid with bond length rHF = 0.9255 Å (gas phase ground rovibrational state geometry). The C60 geometry is of Ih symmetry. The ab initio points were fitted to obtain a PES in terms of bipolar spherical harmonics. The minimum of the PES corresponds to a geometry where the center of mass of HF is located 0.11 Å away from the center of the cage with an interaction energy of -6.929 kcal/mol. The DMS was also represented in terms of bipolar spherical harmonics. The PES was used to calculate the rotation-translation bound states of HF@C60, and good agreement was found relative to the available experimental data [A. Krachmalnicoff et al., Nat. Chem. 8, 953 (2016)] except for the splitting of the first rotational excitation levels. We propose an empirical adjustment to the PES in order to account for the experimentally observed symmetry breaking. The form of that effective PES is additive. We also propose an effective Hamiltonian with an adjusted rotational constant in order to quantitatively reproduce the experimental results including the splitting of the first rotational state. We use our models to compute the molecular volume polarizability of HF confined by C60 and obtain good agreement with experiment.

  3. Répteis e anfíbios de uma região pouco conhecida do sudeste da Amazônia

    Directory of Open Access Journals (Sweden)

    Frederico Gustavo Rodrigues França

    2010-01-01

    Full Text Available Amazônia é a maior floresta tropical do mundo e possui uma enorme biodiversidade. Entretanto, algumas regiões ainda são pouco conhecidas. Este trabalho apresenta um inventário da herpetofauna de uma destas regiões, o município de Boca do Acre, no sudoeste do Amazonas. O inventário foi realizado em dois períodos, uma amostragem durante o meio da estação chuvosa e outra ao final da mesma estação. Diversos métodos foram empregados para as amostragens, como armadilhas de interceptação e queda, procuras visuais diurnas e noturnas, procuras de carro em trechos da BR 317, e registros oportunísticos. Cinqüenta e seis espécies de anfíbios e 53 de répteis foram registradas durante o inventário. Vinte e sete espécies foram capturadas nas armadilhas de interceptação e queda e 38 foram encontradas na BR317, sendo as serpentes o grupo mais impactado por atropelamentos. A curva de acumulação de espécies não atingiu a estabilidade indicando que o inventário não está completo. Os resultados demonstram a grande riqueza de espécies desta região, sua importância para a biodiversidade da Amazônia, e a urgência em sua preservação.

  4. Role of surface thermal properties of HfB2 nanoparticles on heat ...

    Indian Academy of Sciences (India)

    2018-02-02

    Feb 2, 2018 ... flow in MWCNT/novolac composites ... C to investigate the thermal behaviour and the mechanism of mass loss of the samples. Two phenolic matrix ..... endothermic gases undergo heat exchange with the incoming heat flux ...

  5. High-pressure viscosity behavior of x 1,1,1,2-tetrafluoroethane (HFC-134a)+(1-x) triethylene glycol dimethylether (TriEGDME) mixtures: Measurements and modeling

    DEFF Research Database (Denmark)

    Monsalvo, Matias Alfonso; Baylaucq, A.; Cisneros, Sergio

    2006-01-01

    fractions x(HFC) = 0.3427 and 0.5940 (a total of 100 experimental values). Since lubricants and refrigerants are in two different thermodynamic states at atmospheric pressure and ambient temperature, an especially designed falling-body viscometer has been used to perform the measurements. The data obtained...... with a physical and theoretical background, such as the hard-sphere scheme, the free-volume model, and the friction theory....

  6. Heat transfer during condensation of HFC-134a and R-404A inside of a horizontal smooth and micro-fin tube

    Energy Technology Data Exchange (ETDEWEB)

    Sapali, S N [Govt. College of Engineering, Department of Mechanical Engineering, Shivaji Nagar, Pune, Maharashtra 411 005 (India); Patil, Pradeep A [AISSMS College of Engineering, Pune University, Mechanical Engineering Department, Kennedy Road, Near R.T.O., Pune, Maharashtra 411 001 (India)

    2010-11-15

    In recent small and medium capacity refrigeration systems, the condenser tubes are provided with micro-fins from inside. The vapour refrigerant at the compressor outlet and the condenser inlet is in superheat state. As it advances in the condenser it is in two phases and at the outlet it is in sub cooled liquid. The heat transfer coefficient (HTC) during condensation of HFC-134a and R-404A in a smooth (8.56 mm ID) and micro-fin tubes (8.96 mm ID) are experimentally investigated. Different from previous studies, the present experiments are performed for various condensing temperatures, with superheating and sub cooling and using hermetically sealed compressor. The test runs are done at average saturated condensing temperatures ranging from 35 C to 60 C. The mass fluxes are between 90 and 800 kg m{sup -2} s{sup -1}. The experimental results indicate that the average HTC increases with mass flux but decreases with increasing condensing temperature for both smooth and micro-fin tubes. The average condensation HTCs of HFC-134a and R-404A for the micro-fin tubes were 1.5-2.5 and 1.3-2 times larger than that in smooth tube respectively. The HTCs for R-404A are less than that of HFC-134a. New correlations based on the data gathered during the experimentation for predicting condensation HTCs are proposed for wide range of operating conditions. (author)

  7. La producción anfórica en la bahía de Cádiz durante la República como índice de romanización

    OpenAIRE

    García Vargas, Enrique Alberto

    1996-01-01

    Desde al menos el s. II a.C. se producen en la bahía de Cádiz ánforas que imitan formas itálicas contemporáneas. se recogen aquí los resultados de la investigación más reciente en la zona, prestando especial atención al fenómeno de la romanización de Gadir a partir del estudio de la tipología anfórica y de las estructuras de la producción.

  8. Power Optimization of Organic Rankine-cycle System with Low-Temperature Heat Source Using HFC-134a

    Energy Technology Data Exchange (ETDEWEB)

    Baik, Young Jin; Kim, Min Sung; Chang, Ki Chang; Lee, Young Soo; Ra, Ho Sang [Korea Institute of Energy Research, Daejeon (Korea, Republic of)

    2011-01-15

    In this study, an organic Rankine-cycle system using HFC-134a, which is a power cycle corresponding to a low temperature heat source, such as that for geothermal power generation, was investigated from the view point of power optimization. In contrast to conventional approaches, the heat transfer and pressure drop characteristics of the working fluid within the heat exchangers were taken into account by using a discretized heat exchanger model. The inlet flow rates and temperatures of both the heat source and the heat sink were fixed. The total heat transfer area was fixed, whereas the heat-exchanger areas of the evaporator and the condenser were allocated to maximize the power output. The power was optimized on the basis of three design parameters. The optimal combination of parameters that can maximize power output was determined on the basis of the results of the study. The results also indicate that the evaporation process has to be optimized to increase the power output.

  9. Global and regional emissions estimates of 1,1-difluoroethane (HFC-152a, CH3CHF2 from in situ and air archive observations

    Directory of Open Access Journals (Sweden)

    P. G. Simmonds

    2016-01-01

    Full Text Available High frequency, in situ observations from 11 globally distributed sites for the period 1994–2014 and archived air measurements dating from 1978 onward have been used to determine the global growth rate of 1,1-difluoroethane (HFC-152a, CH3CHF2. These observations have been combined with a range of atmospheric transport models to derive global emission estimates in a top-down approach. HFC-152a is a greenhouse gas with a short atmospheric lifetime of about 1.5 years. Since it does not contain chlorine or bromine, HFC-152a makes no direct contribution to the destruction of stratospheric ozone and is therefore used as a substitute for the ozone depleting chlorofluorocarbons (CFCs and hydrochlorofluorocarbons (HCFCs. The concentration of HFC-152a has grown substantially since the first direct measurements in 1994, reaching a maximum annual global growth rate of 0.84 ± 0.05 ppt yr−1 in 2006, implying a substantial increase in emissions up to 2006. However, since 2007, the annual rate of growth has slowed to 0.38 ± 0.04 ppt yr−1 in 2010 with a further decline to an annual average rate of growth in 2013–2014 of −0.06 ± 0.05 ppt yr−1. The annual average Northern Hemisphere (NH mole fraction in 1994 was 1.2 ppt rising to an annual average mole fraction of 10.1 ppt in 2014. Average annual mole fractions in the Southern Hemisphere (SH in 1998 and 2014 were 0.84 and 4.5 ppt, respectively. We estimate global emissions of HFC-152a have risen from 7.3 ± 5.6 Gg yr−1 in 1994 to a maximum of 54.4 ± 17.1 Gg yr−1 in 2011, declining to 52.5 ± 20.1 Gg yr−1 in 2014 or 7.2 ± 2.8 Tg-CO2 eq yr−1. Analysis of mole fraction enhancements above regional background atmospheric levels suggests substantial emissions from North America, Asia, and Europe. Global HFC emissions (so called “bottom up” emissions reported by the United Nations Framework Convention on Climate Change (UNFCCC

  10. Notas sobre predação em uma taxocenose de anfíbios anuros no sudeste do Brasil Predation notes in an anuran amphibians assemblage from southeastern Brazil

    Directory of Open Access Journals (Sweden)

    José P. Pombal Jr

    2007-01-01

    Full Text Available Anfíbios anuros são predados por todos os grupos de vertebrados e muitos invertebrados. Todavia os estudos sobre predação em anfíbios anuros ainda são esparsos e anedóticos. Neste estudo são fornecidas informações sobre predação de anuros de uma assembléia no sudeste do Brasil. Invertebrados (aranhas e barata d’agua, a rã Leptodactylus cf. ocellatus e cinco espécies serpentes (quatro Colubridae e um Viperidae predaram espécies ou indivíduos de pequeno porte.Anuran amphibians are preyer by all vertebrate groups and several invertebrates. However, predation studies on amphibians are still occasional and anecdotic. Herein, informations on predation of an anuran assemblage of southeastern Brazil are provided. Invertebrates (spiders and water bugs, the frog Leptodactylus cf. ocellatus, and five snake species (four Colubridae and one Viperidae preyer on small individuals or small anuran species.

  11. EVALUASI PENGELOLAAN REFRIGERAN CFC, DAN HFC DENGAN MESIN 3R DAN UJI UNJUK KERJA MESIN PENDINGIN STUDI KASUS PADA BENGKEL AC MOBIL DI DENPASAR - BALI

    Directory of Open Access Journals (Sweden)

    I MADE RASTA

    2015-06-01

    Full Text Available CFC refrigerant has been known to be one of causes of ozone layer diminishing and HFC is one of green house gases contributing to global warming through the leak and synthetic refrigerant waste to environment. As a response to the ozone layer diminishment on stratosphere, UNEP, in 1981, through a negotiating process of international stages of development reserve the ozone layer through Wina Convention legalized in March 1985. It was then followed up with Montreal Protocol in September 1987 consisting supervision rules on producing, consuming, and treading ozone damaging materials. The government of Indonesia had ratified the convention through President Decree Number 23 Year 1999. The ozone layer reservation program implementation in Indonesia is facilitated by KLH. Governor of Bali issued Decree Number 523/04-B/HK/2010 on membership restructuring of ozone layer reservation and ozone damaging materials control team work in province of Bali. This research was done in 27 car AC service companies or workshop, which received grant of 3R engine in Denpasar, Bali. The research was dominantly focused on monitoring and evaluation, that is how car AC service company or workshop manage CFC/ R-12 and HFC/R-134a refrigerant at service time using 3R engine that refrigerant does not escape to atmostphere. Cooling machine work procedure test (COP was conducted in laboratory. Research result showed that car AC service company or workshop could manage CFC/ R-12 and HFC /R-l 34a eefctively ( 88,3%. The cooling engine work procedure using CFC /R-12 as the result of 3R engine recovery and recycel resulted in 2,435 while pure CFC/R-12 resulted in 2,54. There were differences in cooling engine work procedure to the use of pure CFC/R-12 refrigerant with that resulted by 3R engine with avarage difference 0,089 or 3,53%.

  12. Technical–economic analysis of including wind farms and HFC to solve hybrid TNEM–RPM problem in the deregulated environment

    International Nuclear Information System (INIS)

    Shayeghi, H.; Hashemi, Y.

    2014-01-01

    Highlights: • Capability of wind farms is contributed in the problem of hybrid TNEM–RPM. • Inclusion of HFC as a novel and versatile device to implement hybrid TNEM–RPM. • INSGA-II optimization and FDM method is applied to specify the best solution. • Simulation study is conducted on the real power system of Iran. - Abstract: This paper addresses a mathematical model for solving transmission network expansion management (TNEM) associated with reactive power management (RPM) in the presence of double-fed induction generator (DFIG) variable speed wind turbine and hybrid flow controller (HFC). According to this plan, the reactive power capability of DFIG wind turbine is gained and the constraints of deliverable power are derived for each operation point. Strong control capability of the HFC with controlling bus voltage and line power flow offers a great potential for solving many of the problems facing electric utilities. For a precise steady-state analysis of HFC, the injection model is considered which it is an adaptive model in steady-state analysis. The main goals of the proposed management strategy are to minimize investment cost, real power loss cost in transmission lines and voltage deviation and maximize voltage stability index and social benefit at the same time. A three-stage scheme has been developed for solving hybrid TNEM–RPM problem. In the beginning of the plan, it is assumed that all the reactive demands are acquired from local sources and an optimal transmission plan is specified. After transmission lines are constructed, in the second step, reactive power sources will be allocated to weak buses. In order to assess reliability of the system, EENS criterion is used. Due to multi-objective nature of the proposed management method, an improved non-dominated sorting genetic algorithm-II (INSGA-II) style is applied for an optimization procedure. Also, a decision making method based on fuzzy decision making (FDM) is used for finding the best

  13. Composição e distribuição espacial e sazonal de anfíbios em unidade de conservação da Mata Atlântica, Alfredo Chaves, Espírito Santo

    OpenAIRE

    Dantas, Roberto de Barros

    2009-01-01

    Este estudo objetivou determinar a composição e distribuição espacial e sazonal de anfíbios anuros da Reserva Particular do Patrimônio Natural Oiutrem, fragmento de Mata Atlântica, região de montanha, Alfredo Chaves, Espírito Santo, Brasil, bem como testar a correlação das variáveis climáticas sobre a atividade de vocalização dessas espécies. As amostragens ocorreram de janeiro de 2008 a fevereiro de 2009, empregando-se os métodos de busca ativa e armadilhas de interceptação e queda (pitfalls...

  14. Energy savings with the effect of magnetic field using R290/600a mixture as substitute for CFC12 and HFC134a

    Directory of Open Access Journals (Sweden)

    Mani Kolandavel

    2008-01-01

    Full Text Available This paper presents an experimental study on the replacement of CFC12 and HFC134a by the new R290/R600a refrigerant mixture as drop-in replacement refrigerant with and without the effect of magnetic field. Without any modification to the system components drop-in experimental tests were performed on a vapour compression refrigeration system with a reciprocating compressor, which was originally designed to operate with CFC12.The test results with no magnets showed that the refrigerant R290/R600a had 19.9-50.1% higher refrigerating capacity than R12 and 28.6-87.2% than R134a. The mixture R290/R600a consumed 6.8- -17.4% more energy than R12. The coefficient of performance of R290/R600a mixture increases from 3.9-25.1% than R12 at lower evaporating temperatures and 11.8-17.6% at higher evaporating temperatures. The effect of magnetic field force reduced the compressor energy consumption by 1.5-2.5% than with no magnets. The coefficient of performance of the system was higher in the range 1.5-2.4% with the effect of magnetic field force. The R290/600a (68/32 by wt.% mixture can be considered as an excellent alternative refrigerant for CFC12 and HFC134a systems.

  15. Evaluation of stratospheric age of air from CF4, C2F6, C3F8, CHF3, HFC-125, HFC-227ea and SF6; implications for the calculations of halocarbon lifetimes, fractional release factors and ozone depletion potentials

    Science.gov (United States)

    Leedham Elvidge, Emma; Bönisch, Harald; Brenninkmeijer, Carl A. M.; Engel, Andreas; Fraser, Paul J.; Gallacher, Eileen; Langenfelds, Ray; Mühle, Jens; Oram, David E.; Ray, Eric A.; Ridley, Anna R.; Röckmann, Thomas; Sturges, William T.; Weiss, Ray F.; Laube, Johannes C.

    2018-03-01

    In a changing climate, potential stratospheric circulation changes require long-term monitoring. Stratospheric trace gas measurements are often used as a proxy for stratospheric circulation changes via the mean age of air values derived from them. In this study, we investigated five potential age of air tracers - the perfluorocarbons CF4, C2F6 and C3F8 and the hydrofluorocarbons CHF3 (HFC-23) and HFC-125 - and compare them to the traditional tracer SF6 and a (relatively) shorter-lived species, HFC-227ea. A detailed uncertainty analysis was performed on mean ages derived from these new tracers to allow us to confidently compare their efficacy as age tracers to the existing tracer, SF6. Our results showed that uncertainties associated with the mean age derived from these new age tracers are similar to those derived from SF6, suggesting that these alternative compounds are suitable in this respect for use as age tracers. Independent verification of the suitability of these age tracers is provided by a comparison between samples analysed at the University of East Anglia and the Scripps Institution of Oceanography. All five tracers give younger mean ages than SF6, a discrepancy that increases with increasing mean age. Our findings qualitatively support recent work that suggests that the stratospheric lifetime of SF6 is significantly less than the previous estimate of 3200 years. The impact of these younger mean ages on three policy-relevant parameters - stratospheric lifetimes, fractional release factors (FRFs) and ozone depletion potentials - is investigated in combination with a recently improved methodology to calculate FRFs. Updates to previous estimations for these parameters are provided.

  16. On-site study of HCFC-22 substitution for HFC non-azeotropic blends (R417A, R422D) on a water chiller of a centralized HVAC system

    Energy Technology Data Exchange (ETDEWEB)

    Torrella, E.; Larumbe, J.A. [Polytechnic University of Valencia, Dep. of Applied Thermodynamics, Camino de Vera 14, E-46022 Valencia (Spain); Cabello, R.; Sanchez, D.; Llopis, R. [Jaume I University, Dep. of Mechanical Engineering and Construction, Campus de Riu Sec s/n, E-12071 Castellon (Spain)

    2010-09-15

    The European Regulation no 2037/2000 has banned manufacturing HCFC refrigerants from January 1st 2010, although its use is allowed up to 2015 if the fluids come from a recycling process. This situation creates the need for developing new working fluids to replace the HCFC in the refrigeration plants now in operation. Among all the HCFCs the R22 is the most widely used in a wide range of applications, especially in air conditioning. This work presents an on-site experimental study of the R22 replacement by two possible substitutes, the HFC-417A and the HFC-422D, in a water chiller in which the energy performance was evaluated. This chiller is part of the centralized HVAC system of a lecture room building at the Jaume I University of Castellon, Spain. This communication compares and analyses main operation parameters of the chiller when operating with each refrigerant in real conditions. (author)

  17. Anfípodos hiperídeos (Crustacea: Peracarida del Parque Nacional Isla del Coco, Costa Rica, Pacífico Tropical Oriental Hyperiid amphipods (Crustacea: Peracarida of the Parque Nacional Isla del Coco, Costa Rica, Eastern Tropical Pacific

    Directory of Open Access Journals (Sweden)

    Rebeca Gasca

    2012-11-01

    Full Text Available Los anfípodos hiperídeos son uno de los grupos de crustáceos pelágicos más frecuentemente encontrados y están entre los más diversos del zooplancton marino. Para determinar la composición de especies de anfípodos hipéridos que habitan las aguas alrededor del Parque Nacional Isla del Coco, Costa Rica, se analizaron 12 muestras de zooplancton. Estas fueron recolectadas mediante arrastres verticales y horizontales con una red de plancton con mallas de 200 y 500 micras y 49cm de diámetro en la boca. Se encontró un total de 22 especies pertenecientes a 17 géneros y 12 familias. Se presenta el listado faunístico de este grupo junto con datos acerca de su taxonomía, su distribución en el área de estudio y su distribución general. La mayor parte de las especies registradas en esta zona han sido reportadas en estudios previos referentes a la región del Pacífico Tropical Oriental y en particular en aguas oceánicas de Costa Rica. Encontramos ocho especies que representan nuevos registros para aguas del Pacífico costarricense, lo que incrementa en un 26% (a 38 el número de especies de hipéridos conocidos en Costa Rica. Las especies más frecuentes fueron Lestrigonus shoemakeri, L. bengalensis, Hyperioides sibaginis y Phronimosis spinifera. Se espera que muestreos adicionales tanto de aguas superficiales como profundas expandan el conocimiento de la diversidad del grupo en esta área protegida.Hyperiid amphipods are one of the most frequently encountered pelagic crustaceans and among the most diverse marine zooplankters. To determine the species composition of the hyperiid amphipods dwelling in the waters around Isla del Coco National Park, Pacific Costa Rica, we analyzad 12 zooplankton samples, collected by vertical and horizontals tows with plankton net with mesh sizes of 200 and 500 microns and 49cm mouth diameter. We recorded a total of 22 species belonging to 17 genera and 12 families. A faunistic list of this group is provided

  18. Anatomia de espécies anfíbias de Cyperaceae de lagoas do semi-árido, BA, Brasil Anatomy of amphibious Cyperaceae species from lakes in the semi-arid region of Bahia State, Brazil

    Directory of Open Access Journals (Sweden)

    Kelly Regina Batista Leite

    2009-09-01

    Full Text Available Foi estudada a anatomia de raízes, rizomas, folhas e escapos de Cyperus odoratus L., Oxycaryum cubense (Poep. & Kunth Lye e Pycreus macrostachyos (Lam. Raynal (Cyperaceae-Poales de lagoas do semi-árido da Bahia visando caracterizar anatomicamente as espécies e levantar estruturas adaptativas à forma de vida anfíbia. As espécies apresentam raízes com epiderme unisseriada, córtex com exoderme e lacunas de ar. Os rizomas apresentam feixes vasculares anfivasais ou colaterais no cilindro vascular. As folhas apresentam epiderme unisseriada, com células de parede periclinal externa mais espessada que a interna, estômatos somente na face abaxial, parênquima clorofiliano alternado com lacunas de ar e feixes vasculares colaterais. Os escapos apresentam epiderme unisseriada, feixes de fibras distribuídos perifericamente alternados com parênquima clorofiliano, lacunas de ar e feixes vasculares colaterais. Oxycaryum cubense difere de Cyperus odoratus e Pycreus macrostachyos por apresentar raízes com pêlos longos, rizomas e estolões com feixes vasculares colaterais, folhas com bordo agudo, e ausência de estrutura Kranz nas folhas e escapos. Características anatômicas como: lacunas de ar observadas principalmente nas raízes, células buliformes na face adaxial da epiderme foliar, hipoderme, reduzido número de elementos xilemáticos e pouca lignificação nas paredes celulares dos tecidos nos diferentes órgãos estudados são consideradas importantes na adaptação dessas plantas anfíbias às lagoas temporárias do semi-árido da Bahia.We examined the anatomy of roots, rhizomes, leaves, and scapes of Cyperus odoratus L., Oxycaryum cubense (Poep. & Kunth Lye, and Pycreus macrostachyos (Lam. Raynal (Cyperaceae-Poales from temporary lakes in the semi-arid region of Bahia in order to characterize the anatomy and examine structural adaptations to amphibious lifestyle. All species had roots with uniseriate epidermal cells, cortex with exoderm

  19. A biodegradabilidade da blenda de poli(β-Hidroxibutirato-co-Valerato/amido anfótero na presença de microrganismos The Biodegradation of polyhydroxybutyrate-co-valerate/amphiprotic starch in the presence of microorganisms

    Directory of Open Access Journals (Sweden)

    Nadjane S. Coelho

    2008-09-01

    Full Text Available O crescimento do consumo de plásticos vem gerando grandes problemas ambientais, pois um polímero, uma vez descartado no ambiente, necessita de mais de cem anos para se degradar. O plástico ideal deve apresentar propriedades industriais desejáveis e, ao mesmo tempo ser degradável num período considerado satisfatório. Busca-se desenvolver plásticos com boas propriedades para embalagens e que possam ser biodegradados quando descartados ao ambiente. Neste trabalho avaliamos a biodegradação da blenda do copolímero poli(β-hidroxibutirato-co-valerato, PHB-HV, que é um termoplástico natural, biodegradável e biocompatível, e do amido anfótero, na proporção de 75 e 25% m/m, respectivamente. Os resultados foram obtidos através do teste de Sturm, uma metodologia para a avaliação da biodegradação na presença de uma cultura mista dos fungos Phanerochaete chrysosporium e Talaromyces wortmannii. Os resultados evidenciam a biodegradação da blenda em função do tempo, de acordo com os resultados do teste de Sturm, com o aparecimento de grupos carboxílicos terminais. Foi detectado também o aparecimento de nova simetria cristalina na estrutura polimérica.The increasing consumption of plastics has generated environmental problems because it takes more than a hundred years for a discarded polymer to degrade. The ideal plastic should present desirable industrial properties and be degradable within a satisfactory time period. Researches is conducted to plastics with good properties for packaging, but that are biodegradable when discarded to the environment. In this work we evaluated the biodegradation of the blend of the copolymer poly(hydroxybutyrate-hydroxyvalerate, PHB-HV, which is a natural, biodegradable and biocompatible thermoplastic, and of the starch amphiprotic, in the proportion of 75 and 25% m/m, respectively. The results were obtained through the Sturm test, a methodology for the evaluation of biodegradation in the presence

  20. Anurofauna da bacia do Rio Tijuco, Minas Gerais, Brasil e sua relação com taxocenoses de anfíbios do Cerrado e suas transições

    Directory of Open Access Journals (Sweden)

    Carlos E. Conte

    2013-09-01

    Full Text Available A supressão de paisagens naturais tem dizimado populações e/ou reduzido a área de ocorrência de muitas espécies de anuros, caso do Cerrado, dado o grande potencial econômico e velocidade de descaracterização por atividades humanas. Por este motivo, inventários de espécies são extremamente necessários nessas regiões que dependendo do grau de alteração ambiental podem prejudicar as atividades de dispersão e reprodução dos anuros. Este estudo tem por objetivo determinar a riqueza e a diversidade de modos reprodutivos da anurofauna da bacia do Rio Tijuco e comparar a composição da taxocenose dessa região com taxocenoses de anfíbios de outras regiões do bioma Cerrado e da floresta estacional semidecidual anteriormente estudadas. O estudo foi desenvolvido ao longo da bacia do Rio Tijuco numa extensão aproximada de 80 km. Através de quatro métodos de amostragem, foram registradas 40 espécies de anuros pertencentes a seis famílias, o que corresponde a 20% das espécies de anuros registradas para o Cerrado. As condições da paisagem favorecem espécies mais tolerantes e adaptadas ao clima mais seco, o que reflete numa taxocenose que possui baixa proporção de modos reprodutivos e uma elevada representatividade de modos generalizados, dependentes de água ou com adaptações contra dessecação. Em comparação com outras 15 localidades verificou-se que a anurofauna do Cerrado é típica, com baixa similaridade taxonômica com ecossistemas adjacentes. A diversidade de habitats e a expressiva riqueza de espécies tornam a bacia do Rio Tijuco de grande importância para a conservação da anurofauna do bioma Cerrado.

  1. Experimental determination of Henry's law constants of difluoromethane (HFC-32 and the salting-out effects in aqueous salt solutions relevant to seawater

    Directory of Open Access Journals (Sweden)

    S. Kutsuna

    2017-06-01

    Full Text Available Gas-to-water equilibrium coefficients, KeqS (in M atm−1, of difluoromethane (CH2F2, a hydrofluorocarbon refrigerant (HFC-32, in aqueous salt solutions relevant to seawater were determined over a temperature (T range from 276 to 313 K and a salinity (S range up to 51 ‰ by means of an inert-gas stripping method. From the van't Hoff equation, the KeqS value in water, which corresponds to the Henry's law constant (KH, at 298 K was determined to be 0.065 M atm−1. The salinity dependence of KeqS (the salting-out effect, ln(KH∕KeqS, did not obey the Sechenov equation but was proportional to S0. 5. Overall, the KeqS(T value was expressed by ln(KeqS(T  =  −49.71 + (77.70 − 0.134  ×  S0. 5  ×  (100∕T + 19.14  ×  ln(T∕100. By using this equation in a lower-tropospheric semi-hemisphere (30–90 °S of the Advanced Global Atmospheric Gases Experiment (AGAGE 12-box model, we estimated that 1 to 4 % of the atmospheric burden of CH2F2 resided in the ocean mixed layer and that this percentage was at least 4 % in the winter; dissolution of CH2F2 in the ocean may partially influence estimates of CH2F2 emissions from long-term observational data of atmospheric CH2F2 concentrations.

  2. Compatibility of manufacturing process fluids with HFC refrigerants and ester lubricants. First draft of final report of part one and quarterly report of part two, January 3, 1994--November 30, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Cavestri, R.C. [Imagination Resources, Inc., Dublin, OH (United States)

    1994-11-01

    Included in this report is a compiled partial list of presently used processing materials in the air-conditioning and refrigeration industry and the manufacturers, intended uses, and applications of each. Also listed are the processing materials that have received final acceptance for this contracted study. An analytical methodology discussion is presented, including the final decision and the limitations of said methodology, as well as how to establish a level of confidence in observed immiscible material components in two 32 ISO VG polyolesters: (1) Mobil EAL Arctic 32; and (2) ICI Emkarate RL32H; both with HFC 134a refrigerant solutions.

  3. Surface Tension and p−ρ−T Data for 1,1,1,3,3-Pentafluorobutane (HFC-365mfc) and 1,1,1,2,2,3,3-Heptafluoro-3-methoxy-propane (HFE-347mcc)

    Czech Academy of Sciences Publication Activity Database

    Klomfar, Jaroslav; Součková, Monika; Pátek, Jaroslav

    2013-01-01

    Roč. 58, č. 8 (2013), s. 2316-2325 ISSN 0021-9568 R&D Projects: GA ČR GA101/09/0010 Institutional support: RVO:61388998 Keywords : surface tension * density * HFC-365mfc * HFE-347mcc Subject RIV: BJ - Thermodynamics Impact factor: 2.045, year: 2013

  4. Utilização medicinal da secreção (“vacina-do-sapo”) do anfíbio kambô (Phyllomedusa bicolor) (Anura: Hylidae) por população não-indígena em Espigão do Oeste, Rondônia, Brasil

    OpenAIRE

    Bernarde, Paulo Sérgio; Santos, Rosimeyri Aparecida

    2011-01-01

    http://dx.doi.org/10.5007/2175-7925.2009v22n3p213 Anfíbios apresentam substâncias farmacologicamente ativas em sua pele com funções de proteção contra infecções de microorganismos e predadores. Algumas tribos indígenas no Sudoeste da Amazônia utilizam a secreção de Phyllomedusa bicolor para fins medicinais. Apesar de existirem relatos sobre a utilização dessa secreção em comunidades indígenas, praticamente nada existe em literatura sobre a prática em populações não indígenas. O presente es...

  5. Utilização medicinal da secreção (“vacina-do-sapo” do anfíbio kambô (Phyllomedusa bicolor (Anura: Hylidae por população não-indígena em Espigão do Oeste, Rondônia, Brasil

    Directory of Open Access Journals (Sweden)

    Paulo Sérgio Bernarde

    2009-06-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2009v22n3p213 Anfíbios apresentam substâncias farmacologicamente ativas em sua pele com funções de proteção contra infecções de microorganismos e predadores. Algumas tribos indígenas no Sudoeste da Amazônia utilizam a secreção de Phyllomedusa bicolor para fins medicinais. Apesar de existirem relatos sobre a utilização dessa secreção em comunidades indígenas, praticamente nada existe em literatura sobre a prática em populações não indígenas. O presente estudo tem como objetivo relatar a utilização da “vacina-do-sapo” por populações não-indígenas em Espigão do Oeste (Rondônia. Foram entrevistadas 31 pessoas que receberam aplicações dessa vacina. A utilização da “vacina-do-sapo” em Espigão do Oeste não se trata de um hábito tradicional da região, sendo que o aplicador veio de outra parte da Amazônia. Em geral, as pessoas que utilizaram a vacina são de classe média a alta e apresentam algum nível de escolaridade (ensino fundamental, médio ou superior. Cerca de metade dos entrevistados acharam que as aplicações ajudaram no problema de saúde que as levaram a receber a vacina ou sentiram melhor disposição após o tratamento e fariam novamente as aplicações. A maioria das pessoas não conhece a espécie P. bicolor, da qual são retiradas as secreções para elaboração da vacina. Embora várias pessoas tenham procurado o tratamento achando que a vacina servia para tudo, suas propriedades medicinais ainda se encontram em estudo.

  6. HFC perspectives in air-conditioning and refrigeration; Perspectives HFC en A/C et refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Fauvarque, P [ELF Atochem, Centre d` Application de Lavallois, 92 (France)

    1998-12-31

    This paper is a series of transparencies dealing with the development of substitutes for the replacement of the R-22 refrigerant in air-conditioning systems (R-134a, R-407C, R-410A), and in industrial refrigeration systems of agriculture and food industry (R-134a and R-404A). (J.S.)

  7. HFC perspectives in air-conditioning and refrigeration; Perspectives HFC en A/C et refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Fauvarque, P. [ELF Atochem, Centre d`Application de Lavallois, 92 (France)

    1997-12-31

    This paper is a series of transparencies dealing with the development of substitutes for the replacement of the R-22 refrigerant in air-conditioning systems (R-134a, R-407C, R-410A), and in industrial refrigeration systems of agriculture and food industry (R-134a and R-404A). (J.S.)

  8. Une activité touristique et de loisir « amphibie » entre espaces de pratiques et territoires de gestion : la plaisance Uma atividade turística e de lazer “anfíbia” entre espaços de práticas e territórios de gestão : o nautismo

    Directory of Open Access Journals (Sweden)

    Ewan Sonnic

    2010-03-01

    of coincidence between practice spaces and management spaces is such as to lead several actors (territorial collectivities, decentralized services of the State, research departments, associations… to operate more and more within the framework of territories copied on practice spaces. The latter remain nevertheless largely fixed by traditional administrative cuttings and see their regularly redefined.Na era do turismo de massa e dos lazeres, o nautismo é uma expressão específica de territorialidade, através de diversos equipamentos construidos na costa (portos, marinas, estaleiros navais, etc. e dos fluxos tanto marítimos como terrestres (itinerários no mar dos iatistas, entre portos e objetivos, ligações domicílio-pontos de embarque, ligações domicílio-trabalho dos profissionais do nautismo, etc.. Este caráter “anfíbio” confere ao nautismo um lugar atípico entre as atividades turísticas.Na França, mais que outros lazeres, o nautismo é esquartejado entre espaços vividos, resultando essencialmente dos percursos dos iatistas (bacias de navegação, bacias de cruzeiro, bacias de nautismo…, e dos territórios administrativos que pertencem a uma lógica bem diferente na terra (coletividades territoriais, subdivisões dos negócios marítimos como no mar (águas territoriais, zona de exercício do direito de polícia.Em conformidade com muitos outros espaços vividos, as áreas de práticas do nautismo são particularmente complexas. Para além do seu caráter crónico, tendo em conta o caráter essencialmente sazonal da atividade, estes territórios vão depender da diversidade das práticas (pesca, passeio no mar, cruzeiro costeiro, cruzeiro do alto mar, vela desportiva…, do regulamento em vigor que proibe a navegação além de certa distância de um abrigo, de acordo com as diferentes categorias de navios, etc. Por a sua parte, os territórios de gestão dependem de uma lógica largamente continental, mesmo perto da costa. A não coincid

  9. Oxidation Resistance, Electrical and Thermal Conductivity, and Spectral Emittance of Fully Dense HfB2 and ZrB2 with SiC, TaSi2, and LaB6 Additives

    Science.gov (United States)

    2012-01-26

    of ZrB2-30 mol% SiC Electrically Heated Ribbons over 1-6 µm5 Spectral radiosities of direct electrically-heated ZrB2-30 mol% SiC specimens were mea...where RT (λ) is the spectral radiosity , h is Planck’s constant, k is Boltzmann’s constant, λ is wavelength, c is the speed of light, and T is the...Thus spectral radiosity measurements were performed at an angle normal to the ribbon surface. Specimens were loaded and removed from the chamber via an O

  10. Novel optical and structural properties of porous GaAs formed by anodic etching of n±GaAs in a HF:C_2H_5OH:HCl:H_2O_2:H_2O electrolyte: effect of etching time

    International Nuclear Information System (INIS)

    Naddaf, M.; Saad, M.

    2014-01-01

    Porous GaAs layers have been formed by anodic etching of n±type GaAs (10.0) substrates in a HF:C_2H_5OH:HCl:H_2O_2:H_2O electrolyte. A dramatic impact of etching time on the optical and structural properties of porous GaAs layer is demonstrated. The nano/micro-features of porous GaAs layers are revealed by scanning electron microscopy (SEM) imaging. Two-peak room temperature photoluminescence (PL), "blue-green"and "green-yellow", is obtained in all prepared porous GaAs samples. Proper adjustment of etching time is found to produce a white color layer, instead of the usual dark gray color of porous GaAs. This is found to cause vast enhancement in the intensity of the visible PL in porous GaAs layer. Chemical composition and structural characterization by means of X-ray photoelectron spectroscopic (XPS), X-ray diffraction (XRD), and micro-Raman spectroscopy, confirm that this layer is characterized with monoclinic β-Ga_2O_3 rich surface. Etching time induced-modification of structural and chemical properties of porous GaAs layer is discussed and correlated to its PL behavior. It is inferred that the "blue-green"PL in porous GaAs can be ascribed to different degrees of quantum confinement in GaAs nano crystallites, whereas, the "green-yellow"PL is highly influenced by the As_2O_3 and Ga_2O_3, content in the porous GaAs layer. In addition, the reflectance measurements reveal an anti-refection trend of behavior of porous GaAs layers in the spectral range (500-1,100 nm). (author)

  11. Atmospheric chemistry of CH3CHF2 (HFC-152a)

    DEFF Research Database (Denmark)

    Taketani, Fumikazu; Nakayama, Tomoki; Takahashi, Kenshi

    2005-01-01

    Smog chamber/Fourier transform infrared (FTIR) and laser-induced fluorescence (LIF) spectroscopic techniques were used to study the atmospheric degradation of CH3CHF2. The kinetics and products of the Cl(2P(3/2)) (denoted Cl) atom- and the OH radical-initiated oxidation of CH3CHF2 in 700 Torr of ...

  12. Thermal conductivity and PVT measurements of pentafluoroethane (refrigerant HFC-125)

    International Nuclear Information System (INIS)

    Tsvetkov, O.B.; Kletski, A.V.; Laptev, Yu.A.

    1995-01-01

    By means of the transient and steady-state coaxial cylinder methods, the thermal conductivity of pentfluoroethane was investigated at temperatures from 187 to 419 K and pressures from atmospheric to 6.0 MPa. The estimated uncertainty of the measured results is ± (2-3)%. The operation of the experimental apparatus was validated by measuring the thermal conductivity of R22 and R12. Determinations of the vapor pressure and PVT properties were carried out by a constant-volume apparatus for the temperature range 263 to 443 K, pressures up to 6 MPa, and densities from 36 to 516 kg m -3 . The uncertainties in temperature, pressure, and density are less than ±10 mK, ±0.08%, and ±0.1%, respectively

  13. Correlation between structural, optical and electrical properties anf the suitability of phase change alloys

    Energy Technology Data Exchange (ETDEWEB)

    Woda, Michael; Steimer, Christoph; Wamwangi, Daniel; Wuttig, Matthias [I. Insitute of Physics (IA), RWTH Aachen University, 52056 Aachen (Germany)

    2007-07-01

    Phase change random access memory (PCRAM) is a very promising candidate to replace Flash memories employed in the non-volatile storage sector. In the active region of this emerging memory, a phase change material is found. This class of materials is already used in rewritable optical data storage. In both application areas the reversible switching between the amorphous and the crystalline state by short current or laser pulses, respectively is used to store data. A key question that has not yet been answered regards the optimum choice of materials for phase change recording. We present a material selection strategy which classifies carefully chosen alloys, being representative for a larger selection of phase change materials, regarding their suitability for non-volatile storage applications. XRD and XRR measurements reveal structural properties of the as-deposited, amorphous and the crystalline state, the corresponding local bond arrangements and the change of film density. Ellipsometry measurements determine the optical contrast of the samples while the temperature dependent resistivity is measured by four point probe experiments. Finally the electrical switching behaviour is tested in nanometer size test cells to validate the full functionality of the chosen materials.

  14. Anfíbios Anuros do Distrito Federal The Frogs of the Federal District of Brazil

    Directory of Open Access Journals (Sweden)

    Bertha Lutz

    1954-03-01

    Full Text Available The frogs of the Federal District of Brazil are listed and discussed as to habit, biology and ecology. The F. D is situated 22° 54' 24" S. & 43° 10' 21" W Gr. and comprises 1.356 km². Its topography includes sea-shore, maritime scrub, lagoons, plains and marsh, open slopes, forested mountains and great heads of rock. Three thousand feet of altitude are attained at two points. Fifty two different frogs occur in the F.D. Three fifths of them live in open country. Two fifths of these have never been found above the plains; the others range higher but mostly in open country. Their environment offers conditions suitable for average tadpoles and adults. these frogs are more or less unspecialized. There are six genera and thirty species. Two thirds of the latter belong to the type genera of the large neotropical families Bufonidae, Leptodactylidae and Hylidae. Only in the maritime scrub formation are conditions somewhat different. Water for average tadpoles is provided by the lagoons. The xerophytism of the vegetation is, however, so marked that bromeliads growing on the ground provide almost the only appropriate shelter for adult tree-frogs used to sleeping upright on the vegetation. One large Hylid genus lives entirely in them. It is casque-headed and phragmotic, shutting the lumen of the leaf-cup with head used as a plug. Another large Hylid genus shows a lesser degree of the same specialization. (Lutz A & Lutz B, 1939 II. One genus with two species is entirely saxicolous; it lives on wet ledges of rock at all phases of its life history. (B. Lutz 1948. The other two fifths of the frogs from F. D. are montane forest forms. Their environment offers numerous and varied biotopes and is near optimum for adults. There is,however, hardly any standing water available for larvae. These frogs are ecologically diversified. They also show a general trend towards spawning in the adult biotipe, which leads to delayed hatching, semi-aquatic and terrestrial larvae and direct development. (B Lutz, 1948. The author interprets the morphological specialization of the casque-headed Hylids and the biological specialization of the montane forest forms as adaptive. Casque-headedness and phragmosis increase protection against blood-suckers and predators. The humidity of the rain forest permits eggs, embryos and larvae to develop, unharmed, outside their usual, aquatic, environment.

  15. MALDI-Imaging Mass Spectrometry of Ochratoxin A and Fumonisins in Mold-Infected Food.

    Science.gov (United States)

    Hickert, Sebastian; Cramer, Benedikt; Letzel, Matthias C; Humpf, Hans-Ulrich

    2016-09-06

    Mycotoxins are toxic secondary metabolites produced by various fungi. Their distribution within contaminated material is of high interest to obtain insight into infection mechanisms and the possibility of reducing contamination during food processing. Various vegetable foodstuffs were infected with fungi of the genera Fusarium and Aspergillus. The localization of the produced mycotoxins was studied by matrix assisted laser desorption ionization time of flight imaging mass spectrometry (MALDI-MSI) of cryosections obtained from infected material. The results were confirmed by HPLC-electrospray ionization triple quadrupole mass spectrometry (HPLC/MS/MS). The mycotoxins ochratoxin A (OTA) and fumonisins of the B- and C-series (FB 1 , FB 2 , FB 3 , FB 4 , FC 2/3 , and FC 4 ) as well as partially hydrolyzed fumonisins (pHFB 1 , pHFB 2 , pHFB 3 , pHFC 1 , and pHFC 2/3 ) could successfully be detected by MALDI-IMS in mold-infested foodstuffs. The toxins are distributed differently in the material: OTA is co-localized with visible fungal spoilage while fumonisins could be detected throughout the whole sample. This work shows the applicability of MALDI-Imaging Mass Spectrometry (MALDI-MSI) to mycotoxin analysis. It has been demonstrated that the analyzed mycotoxins are differently distributed within moldy foodstuffs. These findings show the potential of MALDI-MSI for the localization of these hazardous compounds in various plant tissues. This article is protected by copyright. All rights reserved.

  16. Anfíbios Anuros da coleção Adolpho Lutz: III - Hyla claresignata Lutz & B. Lutz, 1939

    Directory of Open Access Journals (Sweden)

    Bertha Lutz

    1948-12-01

    Full Text Available Hyla claresignata Lutz & Lutz, 1939, is a large species apparently not closely allied to the other known Brazilian hylas. It is characterized by the very small tympanum; the head is short and the snout rounded; the legs are long, the hands and feet unusually large, the latter extensively webbbed. The specific name is derived from the insular, irregular, or roughly triangular, dark spots, with a light halo, found mostly in the dorso-lateral region and on the legs. It belongs to the rain-forest fauna of the Marítime Range. The adult is a bromeliad-dweller and the tadpole rhyacophilous. DESCRIPTION. Vomerine teeth in two separate, oblique, groups, behind the large choanae, parallel to the posterior half of their inner border. Tongue entire, short, very broad and hardly free behind. Snout short, rounded, with distinct canthus rostralis and gradually sloping loreal region. Eye very large and prominent, its horizontal diameter almost equal to the distance between its anterior corner and the tip of the snout. Tympanum very small, less than one third of the diameter of the eye, but distinct, partly covered by a short, heavy ridge. Lateral fingers less than one third webbed; fourth finger slightly longer than the second, just reaching the base of the disk of the third; subarticular tubercles well developed; an angular pollex rudiment, more noticeable in the males. Toes almost completely webbed, the edge of the web inserted at the base of the disk on the third and the fifth; an inner metatarsal tubercle. Skin smooth above, granular beneath, on the throat minutely so. No dermal appendage on the hell. Habit robust, head broader than long, body rather heavy, slightly narrowed in the postaxillary region. Legs long, the tibiotarsal articulation reaching beyond the tip of the snout when adpressed. Type (female: 61 mm. (Fig. 1. DIAGNOSIS of TADPOLE (by G. Orton. "A large specialized, mountain-stream tadpole, with wide head an elongated, flattened snout, greatly enlarged lips and high tooth formula. Eyes dorsal. Spiracle sinistral, projecting, situated far back on side. Anus dextral. Tooth formula 8/12 to 9/14 in fully grown larvae. Tail with a prominent, vertical dark band across musculature and fins; a second concentration of dark pigment near tip of tail, may or may not form a similar but narrower band. Maximum known total length: 60mm.; head and body length 25mm. (Figs. 6 e 7. For further details see Lutz & Lutz, 1939 and Lutz B. & Orton G. 1946.

  17. “Olhar o mar como anfíbio”: humor e política em Luiz Rettamozo

    Directory of Open Access Journals (Sweden)

    Everton de Oliveira Moraes

    2016-08-01

    Full Text Available O artista gaúcho Luiz Carlos Rettamozo atuou intensamente na cena cultural curitibana da década de 1970. Da capital paranaense, Rettamozo buscou participar de uma movimentação que ocorria no Brasil naquele momento, isto é, aquela de um conjunto de poetas, músicos e artistas plásticos que Eduardo Viveiros de Castro sintetizou ao chamar de “tropical-concreta”. Tal movimentação foi vivenciada por uma geração que tinha no humor, entendido de forma ampla, como poética e não apenas como atitude cômica, um modo privilegiado de atuação, uma espécie de “arte das artes”, que permitia jogar com os paradoxos, ambiguidades e avessos da sociedade brasileira. O que interessa apontar neste artigo, por meio da análise da temporalidade própria de alguns dos cartuns e experimentações visuais de Rettamozo, é precisamente o modo como o artista buscou investir no humor não apenas como forma de contestação política à ditadura militar, então instalada no país, mas também como modo de desativar os dispositivos de poder postos para funcionar tanto pelo Estado como pelo mercado, que perpassavam a vida cotidiana brasileira, produzindo um clima de “sufoco”.   Palavras-chave: Rettamozo; Humor; Tempo; Política.

  18. In Anführungszeichen. Glanz und Elend der Political Correctness von Matthias Dusini und Thomas Edlinger

    Directory of Open Access Journals (Sweden)

    Raffaela Rogy

    2014-12-01

    Full Text Available Matthias Dusini und Thomas Edlinger nähern sich in erfrischend lockerem Ton dem Thema Political Correctness (PC, indem sie dessen historisches Gewebe offenlegen, aktuelle Debatten aufzeigen und eigene Überlegungen dazu vorstellen. Raffaela Rogy berichtet.

  19. Anchoring of CoHFC nanoparticles on clinoptilolite for remedy of nuclear wastes

    Directory of Open Access Journals (Sweden)

    Yousefi Taher

    2017-01-01

    Full Text Available To improve the mechanical properties, the cobalt ferrocyanide precipitation was carried out on clinoptilolite as an inorganic polymer. In this work the combination of two important factors, stability (zeolite and high adsorption capacity (cobalt ferrocyanide were considered to improve the ions uptake ability of adsorbent. The modification was approved by X-ray diffraction, Scanning electronic microscopy and Fourier transform infrared spectroscopy. The modified zeolite was applied to remove Sr(II and Cs(I ions from aqueous solution in a batch system. The adsorption capacities of modified zeolite for Cs(I and Sr(II improved to 90 and 130 mgg-1, respectively. The Sr(II and Cs(I removal were investigated as a function of shaking time, pH, Sr(II, and Cs(I initial concentration and temperature. The experimental data were fitted well to Langmuir isotherm model for two sorbet metal ions. The time dependence sorption data showed that the uptakes of Cs(I and Sr(II were very rapid and apparent sorption equilibriums were achieved within 100 min of contact time. The kinetic experimental data were fitted to the pseudo-first order, pseudo-second order, the double exponential, Elovich and intraparticle diffusion models. The sorption rates and capacities as well as rate constants were evaluated.

  20. Exploring policy strategies for mitigating HFC emissions from refrigeration and air conditioning

    NARCIS (Netherlands)

    Hekkenberg, M.; Uiterkamp, Anton J. M. Schoot

    The growing demand for cooling throughout the world, possibly increased by global climate change, requires the implementation of policies to mitigate the related greenhouse gas (GHG) emissions from energy and refrigerant use in the refrigeration and air conditioning (RAC) sector. This article aims

  1. Survey of experimental data of thermophysical properties for difluoromethane (HFC-32)

    Czech Academy of Sciences Publication Activity Database

    Šifner, Oldřich

    1999-01-01

    Roč. 20, č. 6 (1999), s. 1653-1666 ISSN 0195-928X. [Symp.on Thermophysical Properties /13./. Colorado, 22.06.1999-27.06.1999] R&D Projects: GA ČR GA101/95/1369 Subject RIV: BJ - Thermodynamics Impact factor: 0.736, year: 1999

  2. Air-source heat pump carbon footprints: HFC impacts and comparison to other heat sources

    International Nuclear Information System (INIS)

    Johnson, Eric P.

    2011-01-01

    European governments see that heat pumps could reduce carbon emissions in space- and hot-water heating. EU's Renewable Energy Directive designates heat pumps as renewable - eligible for various subsidies - if their carbon footprints are below an implied, average threshold. This threshold omits carbon generated by manufacture and emission of a heat-pump's fluorocarbon refrigerant. It also omits the footprint of the heat pump's hardware. To see if these omissions are significant, this study calculated carbon footprints of representative, residential heat pumps in the UK. Three findings emerged. First, in relation to power generation, which accounts for most of a heat-pump's greenhouse-gas emissions, fluorocarbons add another 20% to the footprint. Second, at UK efficiencies a heat-pump footprint (in kg CO 2 e emitted per kWh delivered) is comparable or higher than footprints of gaseous fuels used in heating. It is lower than the footprint of heating oil and far lower than the footprints of solid fuels. Third, production and disposal of a heat pump's hardware is relatively insignificant, accounting for only 2-3% of the overall heat-pump footprint. Sensitivities to the results were assessed: key factors are footprint of electricity generation, F-gas composition and leak rates and type of wall construction. - Research highlights: → Refrigerant emissions add 20% to a UK air-source heat pump's carbon footprint. → This contribution is so far ignored by regulations. → UK heat pump footprints are comparable to those of gaseous fuels.

  3. Compatibility of lubricant additives with HFC refrigerants and synthetic lubricants. Final report, Part 1

    Energy Technology Data Exchange (ETDEWEB)

    Cavestri, R.C. [Imagination Resources, Inc., Dublin, OH (United States)

    1997-07-01

    Part one of this research provides manufacturers of components of air-conditioning and refrigeration equipment with a useful list of lubricant additives, sources, functional properties and chemical species. The list in part one is comprised of domestic lubricant additive suppliers and the results of a literature search that was specifically targeted for additives reported to be useful in polyolester chemistry.

  4. Zero-ODP Refrigerants for Low Tonnage Centrifugal Chiller Systems

    National Research Council Canada - National Science Library

    Gui, Fulin

    1996-01-01

    ..., HFC-236cb, HFC-236fa, HFC-245cb, and HFC-254cb, for centrifugal chiller applications. We took into account the thermodynamic properties of the refrigerant and aerodynamic properties of the impeller compression process to this evaluation...

  5. Atomphysik für Höhlenmenschen und andere Anfänger das Universum von innen : Moleküle, Atome und Elementarteilchen

    CERN Document Server

    Beetz, Jürgen

    2016-01-01

    Jürgen Beetz zeigt zuerst den Ursprung der erdachten Geschichten der Physik aus der Steinzeit, denn vieles ist so einfach, dass es schon Steinzeitmenschen hätten verstehen können. Im Anschluss daran erklärt der Autor den Aufbau von Atomen und sagt etwas zu ihren physikalischen Größen aus. Obwohl „Atom“ eigentlich „unteilbar“ bedeutet, bestehen Atome dennoch aus Teilen – dies erläutert er im Weiteren genau. Schließlich bespricht er die geheimnisvollen „Quanten“ und ihr merkwürdiges Verhalten.

  6. Kosmologie für Höhlenmenschen und andere Anfänger das Universum von aussen : Trabanten, Planeten, Sterne, Galaxien

    CERN Document Server

    Beetz, Jürgen

    2016-01-01

    Jürgen Beetz zeigt zuerst den Ursprung der erdachten Geschichten der Physik aus der Steinzeit, denn vieles ist so einfach, dass es schon Steinzeitmenschen hätten verstehen können. Im Anschluss daran untersucht der Autor das Weltall auf seine Bestandteile: Monde, Planeten, Sterne, Galaxien usw. Daraus ergibt sich die Frage nach dessen Struktur und Dynamik: Ist das Universum ewig, endlos, konstant? Nichts davon: Es hat eine Entstehungsgeschichte, es expandiert und verändert sich – zum Teil aus noch ungeklärten Ursachen. Besonderes Augenmerk richtet er auf die Expansion des Weltalls und die sich daraus ergebenden Folgen.

  7. Anfíbios anuros de serrapilheira do parque Estadual do Rio Doce: resposta à disponibilidade de recursos e aos fatores climáticos

    OpenAIRE

    Rievers, Camila Rabelo

    2010-01-01

    A herpetofauna associada à serrapilheira apresenta características complexas e particulares quanto ao uso de recursos e estratégias reprodutivas. Ainda há muitas lacunas sobre os padrões de distribuição, abundância, riqueza e diversidade da herpetofauna e os fatores que os influenciam. A presente dissertação teve como objetivo estudar a comunidade de anuros associados à serrapilheira do Parque Estadual do Rio Doce (PERD), e sua relação com a heterogeneidade do habitat, a disponibilidade de al...

  8. Lípidos en el anfípodo Talorchestia margaritae (Amphipoda: Talitridae y su relación con la ecología de la especie

    Directory of Open Access Journals (Sweden)

    Sandra López

    2010-09-01

    Full Text Available T. margaritae cumple un papel importante en la descomposición de restos vegetales y animales en las costas venezolanas. El objetivo fue determinar las diferencias en la composición lipídica entre sexos y talla de la especie. Para esto, especímenes de T. margaritae fueron recolectados en la zona supralitoral de dos playas arenosas: Mangle Quemao y las Mercedes de Paparo. Posteriormente se separaron por talla y sexo determinándoles su peso, densidad, biomasa y perfil lipídico. Todas las categorías presentaron tallas similares entre localidades. Los pesos fueron superiores en los organismos de Mangle Quemao. Los lípidos totales presentaron proporciones similares entre sexos, talla y localidad (3-5%, al igual que los fosfololípidos (20-30%, glicolípidos (<1% y esteroles (4%, exceptuando los triglicéridos (TAG, siendo estos superiores en Mangle Quemao. Esto último pudiendo estar relacionado con la diferencia de pesos entre localidades. Los ácidos grasos más abundantes en ambas localidades fueron 16:0 y 18:1(n-9. Se identificaron otros 9 marcadores con variaciones en su distribución. Con base en los biomarcadores se puede catalogar a T. margaritae como una especie carnívora- generalista, siendo sus poblaciones influenciadas por la disponibilidad de alimento que a su vez, podría inducir diferencias de peso, TAG y biomarcadores.

  9. Lípidos en el anfípodo Talorchestia margaritae (Amphipoda: Talitridae y su relación con la ecología de la especie

    Directory of Open Access Journals (Sweden)

    Sandra López

    2010-09-01

    Full Text Available T. margaritae cumple un papel importante en la descomposición de restos vegetales y animales en las costas venezolanas. El objetivo fue determinar las diferencias en la composición lipídica entre sexos y talla de la especie. Para esto, especímenes de T. margaritae fueron recolectados en la zona supralitoral de dos playas arenosas: Mangle Quemao y las Mercedes de Paparo. Posteriormente se separaron por talla y sexo determinándoles su peso, densidad, biomasa y perfil lipídico. Todas las categorías presentaron tallas similares entre localidades. Los pesos fueron superiores en los organismos de Mangle Quemao. Los lípidos totales presentaron proporciones similares entre sexos, talla y localidad (3-5%, al igual que los fosfololípidos (20-30%, glicolípidos (Lipids in the amphipod Talorchestia margaritae (Amphipoda: Talitridae and its relationship with the ecology of the species. T. margaritae, an endemic species inhabiting Venezuelan coasts, plays an important ecological role in plant and animal decomposition. To understand this issue in some animal groups, especially small ones, lipid composition analysis has been an interesting tool to describe their trophic relationships and food preferences. In order to assess this and visualize the components of their diet, we determined the lipid composition differences between males and females and among age classes in this species. Two sandy beaches were selected: Mangle Quemao and Las Mercedes de Paparo, from which sand samples of known volume were collected at the supralittoral area in 2007. Organisms were separated by age and sex classes, and their size, weight, density, biomass, total lipids (TL, lipid classes and fatty acid markers present in their tissues were determined. The sizes were similar for all age classes between the two locations, while the weights were higher for Mangle Quemao. The TL and lipid classes showed similar proportions between sexes, age classes and locations (TL: 3-5%; Phospholipids: 20-30%; Glycolipids: <1%; sterols: 4%. On the other hand, Triglycerides (TAG were higher in Mangle Quemao, which may be related to the difference between the weights of two locations. The most abundant fatty acid biomarkers in the two studied sites were 16:0 and 18:1(n-9; this last one is characteristic of a carnivorous diet. The other nine markers were identified with changes in their distribution in organisms at Mangle Quemao and between males and females of both populations. Based on observed fatty acids markers we can assume T. margaritae as a generalist carnivore. Those populations were influenced by available food; inducing differences in weight, TAG proportion and markers diversity. Rev. Biol. Trop. 58 (3: 841-855. Epub 2010 September 01.

  10. Românticos, os seres anfíbios: entre a crítica de Kant e a síntese de Hegel

    Directory of Open Access Journals (Sweden)

    Pedro Duarte de Andrade

    2010-06-01

    Full Text Available This article seeks to understand the philosophical situation of some authors whose lives and thoughts were between Kant and Hegel. This age was called German Romanticism. Among its first authors, were Friedrich Schlegel and Novalis, besides Hölderlin. These thinkers sought to overcome Kant’s criticism of all philosophical knowledge that intended to reach the absolute truth, the way things are in themselves. This process, however, was never completed for them – as happened later with the system of Hegel, for whom contradictions would only be accepted as the steps of what he called dialectic, whose essence was, in the end, to resolve them in the figure of synthesis. Finite limitation of man before the whole of being, as it was established by Kant, was left behind with Hegel. Schlegel, Novalis and Hölderlin were not satisfied with the criticism of Kant, but neither did they believe in the synthesis of Hegel. They seem to suggest another path to Western modernity, which is not taken by the fury of Hegelian absolute knowledge without awaking it every time with the Kantian critical consciousness and is not content with this critical consciousness without dreaming with the absolute. This path is what this article seeks to understand.

  11. Super altare in ecclesia tua. Die Anfänge der Pfarrorganisation in den böhmischen Ländern aus archäologischer Sicht

    Czech Academy of Sciences Publication Activity Database

    Štefan, I.; Varadzin, Ladislav

    2014-01-01

    Roč. 31, č. 2 (2014), s. 357-372 ISSN 0231-5432 Institutional support: RVO:67985912 Keywords : Bohemia * Middle Ages * parish organisation * burials * churchyards * church buildings Subject RIV: AC - Archeology, Anthropology, Ethnology

  12. Atmospheric chemistry of HFC-134a. Kinetic and mechanistic study of the CF3CFHO2 + NO2 reaction

    DEFF Research Database (Denmark)

    Møgelberg, T.E.; Nielsen, O.J.; Sehested, J.

    1994-01-01

    A pulse radiolysis system was used to study the kinetics of the reaction of CF3CFHO2 with NO2. By monitoring the rate of the decay of NO2 using its absorption at 400 nm the reaction rate constant was determined to be k = (5.0 +/- 0.5) x 10(-12) cm3 molecule-1 s-1. A long path length Fourier......-transform infrared technique was used to investigate the thermal decomposition of the product CF3CFHO2NO2. At 296 K in the presence of 700 Torr of air, decomposition of CF3CFHO2NO2 was rapid (greater than 90% decomposition within 3 min). The results are discussed in the context of atmospheric chemistry of CF3CFH2...

  13. Role of excited CF3CFHO radicals in the atmospheric chemistry of HFC-134a

    DEFF Research Database (Denmark)

    Wallington, T.J.; Hurley, M.D.; Fracheboud, J.M.

    1996-01-01

    with Oz, CF3CFHO + O-2 --> CF3C(O)F + HO2, and decomposition via C-C bond scission, CF3CFHO + M --> CS3 + HC(O)F + M. CF3CFHO radicals were produced by two different reactions: either via the self-reaction of CF3CFHO2 radicals or via the CF3CFHO2 + NO reaction. It was found that decomposition was much...

  14. Curved spaces before Einstein: Karl Schwarzschild's cosmological speculations and the beginnings of relativistic cosmology (German Title: Gekrümmte Universen vor Einstein: Karl Schwarzschilds kosmologische Spekulationen und die Anfänge der relativistischen Kosmologie)

    Science.gov (United States)

    Schemmel, Matthias

    In contrast to most of his collegues in astronomy and physics, the German astronomer Karl Schwarzschild immediately recognized the significance of general relativity for physics and astronomy, and played a pioneering role in its early development. In this contribution, it is argued that the clue for understanding Schwarzschild's exceptional reaction to general relativity lies in the study of his prerelativistic work. Long before the rise of general relativity, Schwarzschild occupied himself with foundational problems on the borderline of physics, astronomy, and mathematics that, from today's perspective, belong to the field of problems of that theory. In this contribution, the example of Schwarzschild's early speculations about the non-Euclidean nature of physical space on cosmological scales is presented and their reflection in his reception of general relativity is discussed.

  15. Diversidade de anfíbios anuros de uma área de Pampa no município de São Gabriel, Rio Grande do Sul, Brasil

    Directory of Open Access Journals (Sweden)

    Ana Maria R. Bolzan

    2014-09-01

    Full Text Available Considerado um bioma ameaçado, o Pampa possui um dos menores percentuais de área legalmente protegida. Além disso, o conhecimento sobre comunidades de anuros neste bioma ainda é escasso. Nesse contexto, o objetivo deste estudo foi determinar a composição de anuros em uma área de Pampa no sul do Brasil. Entre janeiro de 2009 e fevereiro de 2010 foi realizado um inventário na Fundação Estadual de Pesquisa Agropecuária do município de São Gabriel, Rio Grande do Sul. A procura dos exemplares foi realizada em poças permanentes, semi-permanentes e temporárias pelo método de levantamento em sítio de reprodução. Foram registradas 21 espécies pertencentes a cinco famílias, o que corresponde a aproximadamente 20% das espécies do estado e 42% das espécies conhecidas para a ecorregião Savana Uruguaia. Dez espécies foram consideradas frequentes, sete comuns e quatro foram raras. Foram registrados três modos reprodutivos, sendo que 57% das espécies utilizam o modo 1, que parece estar relacionado à homogeneidade da área. A análise de agrupamento comparando a composição de anuros de quatro localidades distintas mostrou maior similaridade com o município de Candiota (região da Campanha. As espécies presentes na área de estudo são associadas a formações campestres do estado e países vizinhos e podem ser consideradas típicas do bioma Pampa.

  16. Distribuição espacial e sazonal de anfíbios em quatro poças na região serrana do Espírito Santo, sudeste do Brasil: influência de corredores florestais

    Directory of Open Access Journals (Sweden)

    Rodrigo Barbosa Ferreira

    2012-06-01

    Full Text Available Este estudo avaliou a composição da anurofauna, bem como a distribuição espacial e temporal das espécies em quatro poças permanentes em uma região montanhosa do Espírito Santo, sudeste do Brasil. Duas dessas poças são conectadas a fragmentos florestais por corredores florestais e as outras duas poças são circundadas por plantação de eucalipto e habitação humana. Foram registradas 22 espécies, incluídas em cinco famílias, entre dezembro de 2003 a novembro de 2004. Hylidae foi a mais rica e abundante, apresentando elevada sobreposição espacial. Nove espécies foram coletadas em vegetação abaixo de 0,60 m, sendo o sítio de vocalização mais utilizado. Riqueza de espécies e abundância foram maiores em meses chuvosos. Poças com corredores abrigaram maior riqueza de espécies. Adicionalmente quatorze espécies foram exclusivamente encontradas nessas poças. A estrutura da comunidade de anuros em poças permanentes nessa paisagem fragmentada é aparentemente determinada pela presença ou ausência de corredores florestais conectando fragmentos em topos de morro às poças d'água ocorrentes ao longo dos vales.

  17. Anfíbios anuros em áreas em processo de restauração florestal após mineração de bauxita, Poços de Caldas-MG

    OpenAIRE

    Vívian Maria de Faria Nasser Vilela

    2012-01-01

    Dentre as atividades envolvidas no processo de mudança do uso da terra, está a mineração de bauxita, cuja atividade leva à constante perda de hábitat. Uma forma de reparar a degradação antrópica à diversidade e ao funcionamento dos ecossistemas naturais é utilizar o processo de restauração ecológica. Este trabalho utilizou armadilhas-de-queda para estudar o efeito da restauração florestal após a mineração de bauxita na abundância de anuros de serapilheira. Os pontos amostrais encontram-se em ...

  18. Inheritance of the characters glossy and mat of the seed coat in beans (Phaseolus Vulgaris L.) in norm and after gamma rays and ethylmethanesulfonate treatment in Fo anf F1

    International Nuclear Information System (INIS)

    Rodriges, F.; Rukmanski, G.

    1990-01-01

    Reciprocal crosses were made between the following cultivars: 1) kidney bean cvs. Dobrudzhanski 7, Tyrnovo 13 and Astor, having glossy seeds, and Sataya 425 with mat seeds; 2) string bean cvs. Oreol and Zarya (glossy) and Starozagorski Cheren (glossy). Seeds of F o and F 1 were treated with 10 krad gamma rays and 0.01% ethylmethanesulfonate using the mutagens singly and in combination. Deviations from the expected segregation of the characters were observed in kidney beans, being most pronounced following the consequtive treatment, which may be explaned by arisal of mutations and increased frequencies of recombinatipon in the genetic material. This assumption was confirmed in string beans where post mutagen treatment mat seeds were found in hybrids from parental cultivars with glossy seeds and the mat seeds were presented in the following generation. These changes could be explained by arisal of recessive mutations. It is concluded that the combined application of hybridization and mutagenesis increases genetic diversity of the hybrid progeny in regard to glossy and mat bean seed coat. 4 tabs., 2 refs

  19. 40 CFR Appendix C to Subpart B of... - SAE J2788 Standard for Recovery/Recycle and Recovery/Recycle/Recharging Equipment for HFC-134a...

    Science.gov (United States)

    2010-07-01

    ... Part 82 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Servicing of Motor Vehicle Air Conditioners Pt. 82, Subpt. B, App. C... reuse in, mobile air-conditioning systems and recovery/recycling and system recharging of recycled...

  20. Experimental Study of p-rho-T Relationship of Compressed Liquid Phase for Octafluoropropane and Two near Azeotropic Ternary HFC/HC Mixtures

    Czech Academy of Sciences Publication Activity Database

    Klomfar, Jaroslav; Součková, Monika; Pátek, Jaroslav

    2012-01-01

    Roč. 57, č. 5 (2012), s. 1627-1634 ISSN 0021-9568 R&D Projects: GA ČR GA101/09/0010 Institutional research plan: CEZ:AV0Z20760514 Keywords : octafluoropropane * R413a * R417a Subject RIV: BJ - Thermodynamics Impact factor: 2.004, year: 2012 http://pubs.acs.org/doi/abs/10.1021/je300148f

  1. Strain Hardening Cement Composites Structural Design and Performance State-of-the-Art Report of the RILEM Technical Committee 208-HFC, SC3

    CERN Document Server

    Kanda, Tetsushi

    2013-01-01

    Strain Hardening Cement Composites, SHCC hereafter, demonstrate excellent mechanical behavior showing tensile strain hardening and multiple fine cracks. This strain hardening behavior improves the durability of concrete structures employing SHCC and the multiple fine cracks enhance structural performance. Reliable tensile performance of SHCC enables us to design structures explicitly accounting for SHCC’s tensile properties. Reinforced SHCC elements (R/SHCC) indicate large energy absorbing performance under large seismic excitation. Against various types of loads, R/SHCC elements can be designed by superimposing re-bar performance and SHCC’s tensile performance.  This report focuses on flexural design, shear design, FE modeling and anti-seismic design of R/SHCC elements as well as application examples.  Establishing design methods for new materials usually leads to exploring application areas and this trend should be demonstrated by collecting actual application examples of SHCC in structures.

  2. The promotion of sustainable development in China through the optimization of a tax/subsidy plan among HFC and power generation CDM projects

    International Nuclear Information System (INIS)

    Resnier, Martin; Wang, Can; Du, Pengfei; Chen, Jining

    2007-01-01

    China is expected to reach record growth by 2020 in the energy sector by at least doubling its electricity generation capacity. In order to protect the environment and foster economic development, China will greatly benefit from transfers of state-of-the-art power generation technologies through international agreements such as the Clean Development Mechanism (CDM). However, a buyer-driven carbon market and a highly competitive environment due to more cost-effective projects attribute to China's need to achieve a balance between sustainability and profitability for CDM projects implemented in China. In the CDM Tax/Subsidy Optimization Model (CDMTSO Model) here developed, a sustainable development assessment method evaluates the CDM projects' economic and environmental benefits and an optimization program returns tax/subsidy rates at which the greatest number of CDM technologies becomes viable and where 'better' CDM projects can be the most profitable, bringing China's development on a more sustainable path. The results show that the CDMTSO Model brings the sustainable CDM projects' Internal Rate of Return closed to 10%. If a discount rate of 9% is considered, it allows three clean energy technologies (natural gas combined cycle, wind energy, and hydropower) to become economically viable and the environmental costs avoided are increased by 37%

  3. 40 CFR Appendix D to Subpart B of... - SAE J2810 Standard for Recovery Only Equipment for HFC-134a Refrigerant

    Science.gov (United States)

    2010-07-01

    ... removed from, motor vehicle air-conditioning systems. 1. Scope The purpose of this SAE Standard is to... 700 Standard or allow for recycling of the recovered refrigerant to SAE J2788 specifications by using... (R-134a) Recovery/Recycling Equipment and Recovery/Recycling/Recharging for Mobile Air-Conditioning...

  4. Post-translational processing and secretion of atrial natriuretic factor

    International Nuclear Information System (INIS)

    Shields, P.P.

    1988-01-01

    The post-translational processing and regulated secretion of atrial natriuretic factor (ANF) were studied in primary cultures of rat cardiac myocytes. Cultures were established from neonatal rat atria or ventricles, and were maintained for 7-14 days in complete serum free medium. The cultures contained high and constant levels of ANF-(1-126), the known storage form of the hormone in vivo. The cultures also secreted ANF-(1-126), instead of the known circulating form of the hormone, ANF-(99-126). However, the inclusion of the glucocorticoids dexamethasone or hydrocortisone in the culture medium increased the levels of ir-ANF contained and secreted by the cultures, and caused both atrial and ventricular cultures to secrete principally ANF-(99-126) instead of ANF-(1-126). The secreted peptide was shown to be authentic ANF-(99-126) by chromatographic, amino acid composition and radiosequence analysis, thus confirming that the cultures were accurately processing ANF to the in vivo circulating form in the presence of glucocorticoids. Glucocorticoids also caused an increase in size and clustering of atrial myocytes as determined by immunocytochemical analysis, but the morphological effects could be dissociated from the stimulation of ANF-(99-126) secretion by manipulating the timing of glucocorticoid exposure. The location of ANF-(99-126) formation was investigated using biosynthetically labeled 35 S-Cys-ANF-(1-126) in conjunction with actively processing cultures

  5. Removal of atrial natriuretic factor by perfused rabbit lungs in situ

    International Nuclear Information System (INIS)

    Turrin, M.; Maack, T.; Gillis, C.N.

    1986-01-01

    Because atrial natriuretic factor (ANF) can be released from the right atrium into pulmonary blood, the authors studied the possibility of uptake of the peptide by rabbit lung, perfused in situ, at 20 ml/min with Krebs-albumin medium. Single pass removal (multiple indicator dilution with 14 C-dextran as reference) of trace amounts (40 pmoles) of 125 I-ANF was 66 +/- 4% (n=12). This was reduced to 8 +/- 4% by co-injection of 10 μM ANF but was unchanged by co-injection of CPAP (340 nM), an inhibitor of angiotensin-converting enzyme (ACE). When 125 I-ANF was re-circulated through lung, uptake reached maximum at 14 min (64 +/- 5%; n=7). Efflux of 125 I-ANF from preloaded lungs was monoexponential with t/sub 1/2/ = 17.7 min. Recovery of 125 I-ANF uptake after block by unlabelled ANF was studied. For this purpose, lungs were loaded with 0.1 μM unlabelled ANF by recirculating for 20 minutes, after which medium was changed to Krebs-albumin and removal of bolus injections of 125 I-ANF was measured every 5 min. Removal of 125 I-ANF, initially 0%, returned to control levels after 20 min. Thus, 125 I-ANF is removed from the pulmonary circulation by a saturable and reversible process which probably does not involve binding to the ACE present on endothelial cells

  6. Binding and functional effects of atrial natriuretic factor in isolated rat kidney

    International Nuclear Information System (INIS)

    Suzuki, M.; Almeida, F.A.; Nussenzveig, D.R.; Sawyer, D.; Maack, T.

    1987-01-01

    A new methodological approach was developed to study the relationship between specific binding and dose-response curves of the renal effects of atrial natriuretic factor (ANF) in isolated perfused rat kidneys (IK). IK were perfused with 125 I-labeled and unlabeled ANF 1-28 to determine the following: (1) distribution, capacity (C max ), and apparent affinity (S 50 ) of specific binding of ANF 1-28 in cortex, outer medulla, and papilla and (2) dose-response curves of the effects of ANF 1-28 on renal hemodynamics and excretion of fluid and electrolytes. The kidney had a very high density of high-affinity binding sites for ANF. Cortex had >90% of total binding sites whereas papilla had <2% of total binding sites with a 10-fold lower apparent affinity than in cortex. ANF-induced increases in glomerular filtration rate and excretion of fluid and electrolytes were detectable at 10-100 pM and maximal effects occurred at 1-10 nM ANF. Below 1 nM there was no dissociation between the renal hemodynamic and natriuretic effects of ANF. There was a close agreement between dose-response and binding curves of ANF to cortex. Results demonstrates that binding site occupancy in kidney cortex and renal effects of ANF occur at near physiological concentrations of the hormone

  7. Microstructural characterization of as-cast hf-b alloys

    Directory of Open Access Journals (Sweden)

    João Carlos Jânio Gigolotti

    2012-04-01

    Full Text Available An accurate knowledge of several metal-boron phase diagrams is important to evaluation of higher order systems such as metal-silicon-boron ternaries. The refinement and reassessment of phase diagram data is a continuous work, thus the reevaluation of metal-boron systems provides the possibility to confirm previous data from an investigation using higher purity materials and better analytical techniques. This work presents results of rigorous microstructural characterization of as-cast hafnium-boron alloys which are significant to assess the liquid composition associated to most of the invariant reactions of this system. Alloys were prepared by arc melting high purity hafnium (minimum 99.8% and boron (minimum 99.5% slices under argon atmosphere in water-cooled copper crucible with non consumable tungsten electrode and titanium getter. The phases were identified by scanning electron microscopy, using back-scattered electron image mode and X-ray diffraction. In general, a good agreement was found between our data and those from the currently accepted Hafnium-Boron phase diagram. The phases identified are αHfSS and B-RhomSS, the intermediate compounds HfB and HfB2 and the liquide L. The reactions are the eutectic L ⇔ αHfSS + HfB and L ⇔ HfB2 + B-Rhom, the peritectic L + HfB2 ⇔ HfB and the congruent formation of HfB2.

  8. Environmental Forensics

    Science.gov (United States)

    2011-03-29

    1,1- Difluoroethane (HFC-152a) Dibromodifluoromethane (Halon 1202) 1,2-Dichloro-1,1,2,2-tetrafluoroethane (CFC-114) Dib th 1 2 Di hl th (F 150)romome... difluoroethane (HCFC-142b) Dichloromethane (DCM) 2-Chloro-1,1,1,2-tetrafluoroethane (HFC-124) Difluoromethane (HFC32) Dibromotetrafluoroethane (Halon

  9. Fast Bitwise Implementation of the Algebraic Normal Form Transform

    OpenAIRE

    Bakoev, Valentin

    2017-01-01

    The representation of Boolean functions by their algebraic normal forms (ANFs) is very important for cryptography, coding theory and other scientific areas. The ANFs are used in computing the algebraic degree of S-boxes, some other cryptographic criteria and parameters of errorcorrecting codes. Their applications require these criteria and parameters to be computed by fast algorithms. Hence the corresponding ANFs should also be obtained by fast algorithms. Here we continue o...

  10. Ozone depleting substances and gases HFCs, PFCs and SF{sub 6}. Consumption and emissions 2003; Ozonlagsnedbrydende stoffer og drivhusgasserne HFC'er PFC'er og SF6. Forbrug og emissioner 2003

    Energy Technology Data Exchange (ETDEWEB)

    Sander Poulsen, T.

    2005-07-01

    The evaluation includes a calculation of actual emissions of HFCs, PFCs and SF{sub 6} in Denmark. In this calculation of actual emissions, the release from stock of greenhouse gases in products has been taken into account, and adjustments have been made for imports and exports of the greenhouse gases in products. The evaluation has partly been prepared to enable Denmark to fulfil its international obligations to provide information within this area, and partly to follow the trend in consumption and emissions of HFCs, PFCs and SF{sub 6}. (BA)

  11. Ozone depleting substances and greenhouse gases HFCs, PFCs and SF{sub 6} consumption and emissions; Ozonlagsnedbrydende stoffer og drivhusgasserne HFC'er, PFC'er og SF{sub 6}. Forbrug og emissioner 2002

    Energy Technology Data Exchange (ETDEWEB)

    Sander Poulsen, T. [Planmiljoe, Veksoe Sjaelland (Denmark)

    2004-07-01

    The aim of the project is to map the 2002 Danish consumption of produced ozone depleting substances and the consumption and actual emission of the greenhouse gases HFCs, PFCs and SF{sub 6}. The inventory is performed, partly according to the guidelines recommended by IPCC (Intergovernmental Panel on Climate Change), and partly according to the method that has been used for previous mappings. The mapping is done partly in order to meet Denmark's international commitments to report and partly in order to monitor how the consumption of ozone depleting substances and the emissions of greenhouse gases develop. The mapping of ozone depleting substances includes the net consumption, meaning the amount of the imported raw materials in bulk or in drums minus any re-export of the substances in the form of raw materials. Mapping of the actual emissions of HFCs, PFCs and SF{sub 6} is done in continuation of previous greenhouse gas inventories. The inventory process is continuously improving due to development of international approved guidelines (IPCC) and the production of increasingly detailed data. (BA)

  12. Random survey of HFC and R22 emission, refrigerants and leakage percentage in the dairy, meat and other food industries; Steekproefonderzoek HFK en R22-emissies, koudemiddelvulling en lekpercentage in de Zuivel, Vlees en Overige voedingsmiddelensectoren

    Energy Technology Data Exchange (ETDEWEB)

    Pennartz, A.M.G.; Van den Bovenkamp, M.V. [KWA Bedrijfsadviseurs, Amersfoort (Netherlands)

    2012-08-15

    The EU member states are obliged to bring the EU F-gas and Ozone policy into operation, by minimalizing the R22 and F-gas emissions in cooperation with market parties. Factors that may guide the refrigerant emission policy are: leakage percentages per year (company level, sector, national level); emission quantities (company level, sector, national level); indirect indicators: knowledge, experience with refrigerating contractors, feed back to end users, proactive prevention by end users. At this moment there is no clear view of the emission percentages in practice with the end users. For this reason the Dutch Ministry of Infrastructure and the Environment, by NL Agency, has initiated a random test survey in the Dairy, Meat and Other Food sectors. The main goal is to obtain data on the size and trends of R22 and HFK emissions in the period 2007-2010 [Dutch] De EU-lidstaten dienen uitvoering te geven aan het EU F-gas en Ozon-beleid, door met de markt te streven naar minimale R22 en F-gas emissies bij de eindgebruikers. Indicatoren (trends) om het koudemiddel emissiebeleid op te kunnen sturen zijn: jaarlijks optredende lekpercentages (per bedrijf, sector, totaal NL); emissiehoeveelheden (per bedrijf, sector, totaal NL); indirecte factoren: kennis/ervaring in lekkagepreventie bij koelinstallateurs, terugkoppeling naar de opdrachtgevers, preventiebeleid/prioriteit vanuit de opdrachtgevers. Tot nu toe ontbreekt een scherp beeld van de optredende lekpercentages (grootte, trends) bij de eindverbruikers. Daarom is door het Ministerie van IenM, via Agentschap NL een steekproefonderzoek uitgezet in de sectoren Zuivel, Vlees en Overige voedingsmiddelen. Doel is een beeld te krijgen van de omvang en trend van de R22 en HFK-emissies over 2007-2010.

  13. Atrial natriuretic factor increases vascular permeability

    International Nuclear Information System (INIS)

    Lockette, W.; Brennaman, B.

    1990-01-01

    An increase in central blood volume in microgravity may result in increased plasma levels of atrial natriuretic factor (ANF). Since elevations in plasma ANF are found in clinical syndromes associated with edema, and since space motion sickness induced by microgravity is associated with an increase in central blood volume and facial edema, we determined whether ANF increases capillary permeability to plasma protein. Conscious, bilaterally nephrectomized male rats were infused with either saline, ANF + saline, or hexamethonium + saline over 2 h following bolus injections of 125I-albumin and 14C-dextran of similar molecular size. Blood pressure was monitored and serial determinations of hematocrits were made. Animals infused with 1.0 micrograms.kg-1.min-1 ANF had significantly higher hematocrits than animals infused with saline vehicle. Infusion of ANF increased the extravasation of 125I-albumin, but not 14C-dextran from the intravascular compartment. ANF also induced a depressor response in rats, but the change in blood pressure did not account for changes in capillary permeability to albumin; similar depressor responses induced by hexamethonium were not accompanied by increased extravasation of albumin from the intravascular compartment. ANF may decrease plasma volume by increasing permeability to albumin, and this effect of ANF may account for some of the signs and symptoms of space motion sickness

  14. Atrial natriuretic factor in maternal and fetal sheep

    International Nuclear Information System (INIS)

    Cheung, C.Y.; Gibbs, D.M.; Brace, R.A.

    1987-01-01

    To determine atrial natriuretic factor (ANF) concentrations in the circulation and body fluids of adult pregnant sheep and their fetuses, pregnant ewes were anesthetized with pentobarbital sodium, and the fetuses were exteriorized for sampling. ANF concentration, as measured by radioimmunoassay, was 47 +/- 6 (SE) pg/ml in maternal plasma, which was significantly higher than the 15 +/- 3 pg/ml in maternal urine. In the fetus, plasma ANF concentration was 265 +/- 49 pg/ml, 5.6 times that in maternal plasma. No umbilical arterial and venous difference in ANF concentration was observed. Fetal urine ANF concentration was significantly lower than that in fetal plasma, and was similar to that measured in amniotic and allantoic fluid. In chronically catheterized maternal and fetal sheep, fetal plasma ANF was again 5.1 times that in maternal plasma, and these levels were not different from those measured in acutely anesthetized animals. These results demonstrate that immunoreactive ANF is present in the fetal circulation at levels higher than those found in the mother. The low concentration of ANF in fetal urine suggests that ANF is probably metabolized and/or reabsorbed by the fetal kidney

  15. Advanced Nuclear Fuels Corporation: one year later

    International Nuclear Information System (INIS)

    Bjoernard, T.A.; Sofer, G.A.

    1988-01-01

    About one year ago, after 18 years of business as a wholly owned affiliate of Exxon Corporation, Exxon Nuclear Company was acquired by Siemens/KWU and its name was changed to Advanced Nuclear Fuels Corporation (ANF). This profile describes the status of ANF one year later, principally from the European perspective but with some mention of ANF's worldwide operations to provide a balanced picture. After one year of operation as an affiliate of Siemens/KWU, ANF's role remains as an independent international supplier of nuclear fuel and services to utilities in Europe, the USA and the Far East, but with substantially augmented capabilities resulting from the new affiliation

  16. Lupus erythematosus cell preparation, antinuclear factor and antideoxyribonucleic acid antibody incongruity in systemic lupus erythematosus.

    Science.gov (United States)

    Chee, Y C

    1983-01-01

    'Total antinuclear antibody' (ANF) is detected by the fluorescent antinuclear antibody technique which is a screening test, positive in 99% of systemic lupus erythematosus (SLE) sera. The LE factor (positive in 75% of SLE sera), like the anti-DNA antibody, is an antinuclear antibody but directed against DNA-histone. ANF-negative SLE is a clinical entity with absence of these antibodies. A false negative ANF, in the presence of high titre anti-DNA antibody and/or LE cells, is illustrated in two cases of SLE. Postulated mechanisms for this phenomenon are interference in ANF detection by rheumatoid factor, and the prozone effect on the immunofluorescent tests.

  17. Atom-vacancy ordering and magnetic susceptibility of nonstoichiometric hafnium carbide

    International Nuclear Information System (INIS)

    Gusev, A.I.; Zyryanova, A.N.

    1999-01-01

    Experimental results on magnetic susceptibility of nonstoichiometric hafnium carbide HfC y (0.6 0.71 , HfC 0.78 and HfC 0.83 in the range of 870-930 K the anomalies are revealed which are associated with superstructure short-range ordering in a non-metallics sublattice. It is shown that a short-range order in HfC 0.71 and HfC 0.78 carbides corresponds to Hf 3 C 2 ordered phase, and in HfC 0.83 carbide - to Hf 6 C 5 ordered phase. HfC 0.78 carbide is found to possesses zero magnetic susceptibility in temperature range 910-980 K [ru

  18. African-American English i direkt anföring : Etta James självbiografi översatt till svenska – att anpassa översättningen efter en varietet som inte har någon motsvarighet på svenska

    OpenAIRE

    Anteryd, Linn

    2015-01-01

    Detta examensarbete är indelat i tre delar. Examensarbetet består av en översättning av tre kapitel ur Etta James självbiografi Rage to survive: the Etta James story skriven av James och spökförfattaren David Ritz, samt ett kapitel om vilka textspecifika översättningsproblem som uppstod vid översättningen. Den tredje delen består av en djupanalys av hur varieteten African-American English (AAE) översatts i två andra verk, nämligen I know why the caged bird sings av Maya Angelou och The bluest...

  19. Removal of atrial natriuretic factor by perfused rabbit lungs in situ

    Energy Technology Data Exchange (ETDEWEB)

    Turrin, M.; Maack, T.; Gillis, C.N.

    1986-03-05

    Because atrial natriuretic factor (ANF) can be released from the right atrium into pulmonary blood, the authors studied the possibility of uptake of the peptide by rabbit lung, perfused in situ, at 20 ml/min with Krebs-albumin medium. Single pass removal (multiple indicator dilution with /sup 14/C-dextran as reference) of trace amounts (40 pmoles) of /sup 125/I-ANF was 66 +/- 4% (n=12). This was reduced to 8 +/- 4% by co-injection of 10 ..mu..M ANF but was unchanged by co-injection of CPAP (340 nM), an inhibitor of angiotensin-converting enzyme (ACE). When /sup 125/I-ANF was re-circulated through lung, uptake reached maximum at 14 min (64 +/- 5%; n=7). Efflux of /sup 125/I-ANF from preloaded lungs was monoexponential with t/sub 1/2/ = 17.7 min. Recovery of /sup 125/I-ANF uptake after block by unlabelled ANF was studied. For this purpose, lungs were loaded with 0.1 ..mu..M unlabelled ANF by recirculating for 20 minutes, after which medium was changed to Krebs-albumin and removal of bolus injections of /sup 125/I-ANF was measured every 5 min. Removal of /sup 125/I-ANF, initially 0%, returned to control levels after 20 min. Thus, /sup 125/I-ANF is removed from the pulmonary circulation by a saturable and reversible process which probably does not involve binding to the ACE present on endothelial cells.

  20. Atriopeptin II stimulates chloride secretion in the isolated operculum epithelium of Fundulus heteroclitus

    International Nuclear Information System (INIS)

    Zadunaisky, J.A.; Scheide, J.I.

    1986-01-01

    Whole killifish efflux of 36 Cl was increased more than 2x with the addition of 1.4 x 10 -7 M atriopeptin (ANF) to the seawater bath. Atriopeptin II (10 -7 M) added serosally to the isolated Fundulus heteroclitus opercular epithelium resulted in a consistent stimulation of the short-circuit current, from 129.5 +/- 12.3 to 153.5 +/- 13.4 μA/cm 2 . Tissue resistance was decreased 10% from 114.9 +/- 14.2 to 103.9 +/- 11.8 Omega x cm 2 indicating a change in chloride conductance. The effect of ANF was maximal at 10 -7 M and mucosal addition of ANF was ineffective in stimulating the opercular current. The ANF current stimulation did not interfere with the isoproterenol (10 -6 M) response but ANF did not stimulate the current if added after isoproterenol. Serosal addition of propranolol (10 -5 M), sufficient to inhibit 10 -6 M isoproterenol, had no effect on the ANF response. The serosal addition of 10 -6 M tetrodotoxin or 10 -4 M diltiazem did not inhibit the ANF response. The stimulatory effect observed by ANF did not involve the isoproterenol receptor or nerve activation; however, it was a distinct stimulatory response on the isolated opercular epithelium

  1. Regularized Adaptive Notch Filters for Acoustic Howling Suppression

    DEFF Research Database (Denmark)

    Gil-Cacho, Pepe; van Waterschoot, Toon; Moonen, Marc

    2009-01-01

    In this paper, a method for the suppression of acoustic howling is developed, based on adaptive notch filters (ANF) with regularization (RANF). The method features three RANFs working in parallel to achieve frequency tracking, howling detection and suppression. The ANF-based approach to howling...

  2. Analysis of forest health monitoring surveys on the Allegheny National Forest (1998-2001)

    Science.gov (United States)

    Randall S. Morin; Andrew M Liebhold; K.W. Gottschalk; Chris W. Woodall; Daniel B. Twardus; Robert L. White; Stephen B. Horsley; Todd E. Ristau

    2006-01-01

    Describes forest vegetation and health conditions on the Allegheny National Forest (ANF). During the past 20 years, the ANF has experienced four severe droughts, several outbreaks of exotic and native insect defoliators, and the effects of other disturbance agents. An increase in tree mortality has raised concerns about forest health. Historical aerial surveys (1984-98...

  3. Forest health conditions on the Allegheny National Forest (1989-1999): Analysis of forest health monitoring surveys

    Science.gov (United States)

    R.S. Morin; A.M. Liebhold; K.W. Gottschalk; D.B. Twardus; R.E. Acciavatti; R.L. White; S.B. Horsley; W.D. Smith; E.R. Luzader

    2001-01-01

    This publication describes the forest vegetation and health conditions of the Allegheny National Forest (ANF). During the past 15 years, the ANF has experienced four severe droughts, several outbreaks of exotic and native insect defoliators, and the effects of other disturbance agents. An increase in tree mortality has raised concerns about forest health. Historical...

  4. Reproductive and developmental toxicity of hydrofluorocarbons used as refrigerants.

    Science.gov (United States)

    Ema, Makoto; Naya, Masato; Yoshida, Kikuo; Nagaosa, Ryuichi

    2010-04-01

    The present paper summarizes data on the reproductive and developmental toxicity of hydrofluorocarbons (HFCs), including pentafluoroethane (HFC-125), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,1-trifluoroethane (HFC-143a), 1,1-difluoroethane (HFC-152a), difluoromethane (HFC-32) and 1,1,1,3,3-pentafluoropropane (HFC-245fa), used as refrigerants, published in openly available scientific literature. No developmental toxicity of HFC-125 was found even at 50,000 ppm in rats or rabbits. Although HFC-134a exhibited no dominant lethal effect or reproductive toxicity in rats, it caused low body weight in pre- and postnatal offspring and slightly retarded skeletal ossification in fetuses at 50,000 ppm in rats. No maternal or developmental toxicity was noted after exposure to HFC-143a even at 40,000 ppm in rats or rabbits or HFC-152a even at 50,000 ppm in rats. HFC-32 is slightly maternally and developmentally toxic at 50,000 ppm in rats, but not in rabbits. HFC-245fa caused decreases in maternal body weight and food consumption at 10,000 and 50,000 ppm and fetal weight at 50 000ppm. No evidence of teratogenicity for these HFCs was noted in rats or rabbits. There is limited information about the reproductive toxicity of these HFCs. Animal studies remain necessary for risk assessments of chemicals because it is difficult to find alternative methods to determine the toxic effects of chemicals. It is required to reduce emissions of organic vapors containing HFCs to reduce the risk of exposure. Copyright 2009 Elsevier Inc. All rights reserved.

  5. Diseño de una red WAN

    OpenAIRE

    Labella Sanz, Gabriel

    2010-01-01

    Disseny d'una xarxa WAN, formada per una xarxa d'Accés HFC, una xarxa de Commutació ATM i una xarxa de Transport SDH. Diseño de una red WAN, formada por una red de Acceso HFC, una red de Conmutación ATM y una red de Transporte SDH. WAN network design consisting of a HFC access network, an ATM switching network and a SDH transport network.

  6. 78 FR 12310 - Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2011

    Science.gov (United States)

    2013-02-22

    ... dioxide (CO 2 ), methane (CH 4 ), nitrous oxide (N 2 O), hydrofluorocarbons (HFC), perfluorocarbons (PFC..., petrochemical production, phosphoric acid, titanium dioxide, lime production, and several fluorinated gas...

  7. Specific binding of atrial natriuretic factor in brain microvessels

    International Nuclear Information System (INIS)

    Chabrier, P.E.; Roubert, P.; Braquet, P.

    1987-01-01

    Cerebral capillaries constitute the blood-brain barrier. Studies of specific receptors (neurotransmitters or hormones) located on this structure can be performed by means of radioligand-binding techniques on isolated brain microvessels. The authors examined on pure bovine cerebral microvessel preparations the binding of atrial natriuretic factor (ANF), using 125 I-labeled ANF. Saturation and competition experiments demonstrated the presence of a single class of ANF-binding sites with high affinity and with a binding capacity of 58 fmol/mg of protein. The binding of 125 I-labeled ANF to brain microvessels is specific, reversible, and time dependent, as is shown by association-dissociation experiments. The demonstration of specific ANF-binding sites on brain microvessels supposes a physiological role of ANF on brain microvasculature. The coexistence of ANF and angiotensin II receptors on this cerebrovascular tissue suggests that the two circulating peptides may act as mutual antagonists in the regulation of brain microcirculation and/or blood-brain barrier function

  8. Atrial natriuretic factor binding sites in experimental congestive heart failure

    International Nuclear Information System (INIS)

    Bianchi, C.; Thibault, G.; Wrobel-Konrad, E.; De Lean, A.; Genest, J.; Cantin, M.

    1989-01-01

    A quantitative in vitro autoradiographic study was performed on the aorta, renal glomeruli, and adrenal cortex of cardiomyopathic hamsters in various stages of heart failure and correlated, in some instances, with in vivo autoradiography. The results indicate virtually no correlation between the degree of congestive heart failure and the density of 125I-labeled atrial natriuretic factor [(Ser99, Tyr126)ANF] binding sites (Bmax) in the tissues examined. Whereas the Bmax was increased in the thoracic aorta in moderate and severe heart failure, there were no significant changes in the zona glomerulosa. The renal glomeruli Bmax was lower in mild and moderate heart failure compared with control and severe heart failure. The proportion of ANF B- and C-receptors was also evaluated in sections of the aorta, adrenal, and kidney of control and cardiomyopathic hamsters with severe heart failure. (Arg102, Cys121)ANF [des-(Gln113, Ser114, Gly115, Leu116, Gly117) NH2] (C-ANF) at 10(-6) M displaced approximately 505 of (Ser99, Tyr126)125I-ANF bound in the aorta and renal glomeruli and approximately 20% in the adrenal zona glomerulosa in both series of animals. These results suggest that ANF may exert a buffering effect on the vasoconstriction of heart failure and to a certain extent may inhibit aldosterone secretion. The impairment of renal sodium excretion does not appear to be related to glomerular ANF binding sites at any stage of the disease

  9. Design and methodology of the NorthStar Study

    DEFF Research Database (Denmark)

    Schou, Morten; Gustafsson, Finn; Videbaek, Lars

    2008-01-01

    Randomized clinical trials have shown that newly discharged and symptomatic patients with chronic heart failure (CHF) benefit from follow-up in a specialized heart failure clinic (HFC). Clinical stable and educated patients are usually discharged from the HFC when on optimal therapy. It is unknown...

  10. Analysis of South Carolina hydrogen and fuel cell workers views and opinion leadership behavior: A waiting opportunity?

    Energy Technology Data Exchange (ETDEWEB)

    Besley, John C. [School of Journalism and Mass Communications, University of South Carolina, Columbia, SC 29205 (United States); Baxter-Clemmons, Shannon [South Carolina Hydrogen Fuel Cell Alliance, P.O. Box 12302, Columbia, SC 29201 (United States)

    2010-08-15

    The current study uses quantitative survey results to explore what a near census of hydrogen and fuel cell (HFC) workers in South Carolina (n = 70) say about their HFC experiences and the degree to which these workers can be expected to act as opinion leaders for the field. In general, these workers say they are positive about the environmental, national security, and economic potential of HFC technologies. They further see HFC technologies as having small and manageable levels of risk. A number of these workers exhibit characteristics associated with both issue-specific and general opinion leadership. Issue-specific leadership and positive views about HFC technology were associated with higher levels of self-reported technology-related interpersonal discussion. The study concludes that the existence of workers with positive HFC experiences and a demonstrated interest in telling others about their experiences may represent an opportunity for those charged with promoting HFC development and adoption. Future efforts should explore how HFC workers could be effectively integrated into such efforts as a means of reaching difficult to reach audiences. (author)

  11. Rate Constants for the Reactions of OH with CH(sub 3)Cl, CH(sub 2) C1(sub 2), CHC1(sub 3)and CH(sub 3)Br

    Science.gov (United States)

    Hsu, H-J.; DeMore, W.

    1994-01-01

    Rate constants for the reactions of OH with CH3C1, CH2Cl2, CHCl3 and CH3Br have been measured by a relative rate technique in which the reaction rate of each compound was compared to that of HFC-152a (CH3CHF2)and for CH2Cl2, HFC-161 (CH3CH2F).

  12. High temperature strengthening mechanism of hafnium carbide in a tungsten-rhenium matrix

    International Nuclear Information System (INIS)

    Luo, A.; Shin, K.S.; Jacobson, D.L.

    1991-01-01

    The interrelationship between the testing temperature and HfC strength increment of an arc-melted W-3.6Re-0.4HfC was determined from 1950 K to 2980 K in a vacuum of better than 1.3x10 -5 Pa (10 -7 torr). The present research was focused on the characteristic temperature at which the rapid coarsening of HfC particles occurred and the effect of the second-phase particle size on the high temperature strength properties of this material. It was found that the HfC particle strengthening was effective in a W-Re matrix up to a characteristic temperature of 2450 K in the short-term tensile test. Carbon was found to be the rate-limiting solute in the HfC particle growth. The strength of HfC strengthened alloy at temperature above 0.5 T m is proportional to the square root of particle volume fraction. The yield strengths of W-3.6Re-0.26HfC calculated based on the particle statistical distribution had good agreement with the experimental values from 1950 K to 2980 K. Besides, an addition of 0.26 percent HfC in tungsten resulted in about 28 percent increase in the activation energy of plastic deformation at high temperatures

  13. 40 CFR Appendix E to Subpart B of... - The Standard for Automotive Refrigerant Recycling Equipment Intended for Use With Both CFC-12 and...

    Science.gov (United States)

    2010-07-01

    ... Refrigerant Recycling Equipment Intended for Use With Both CFC-12 and HFC-134a E Appendix E to Subpart B of... Appendix E to Subpart B of Part 82—The Standard for Automotive Refrigerant Recycling Equipment Intended for... Intended for Use With Both CFC-12 and HFC-134a Foreword The purpose of this standard is to establish...

  14. Cryoinsulation Material Development to Mitigate Obsolescence Risk for Global Warming Potential Foams

    Science.gov (United States)

    Protz, Alison; Bruyns, Roland; Nettles, Mindy

    2015-01-01

    Cryoinsulation foams currently being qualified for the Space Launch System (SLS) core stage are nonozone- depleting substances (ODP) and are compliant with current environmental regulations. However, these materials contain the blowing agent HFC-245fa, a hydrofluorocarbon (HFC), which is a Global Warming Potential (GWP) substance. In August 2014, the Environmental Protection Agency (EPA) proposed a policy change to reduce or eliminate certain HFCs, including HFC-245fa, in end-use categories including foam blowing agents beginning in 2017. The policy proposes a limited exception to allow continued use of HFC and HFC-blend foam blowing agents for military or space- and aeronautics-related applications, including rigid polyurethane spray foams, but only until 2022.

  15. Clinical significance of plasma atrial natriuretic factor and endothelin detection in hyperthyroidism and hypothyroidism

    International Nuclear Information System (INIS)

    Zhu Yalin; Huo Ying; Pan Yunlong

    2005-01-01

    Plasma at rial natriuretic factor (ANF) and endothelin (ET) were detected by RIA in 58 cases of hyperthyroidism and 47 cases of hypothyroidism. Before the ANF and ET concentration of untreatment hyperthyroid patients was much higher than that of treatment hyperthyroid patients, hypothyroid patients before and after treatment and the normal group (P 3 and FT 4 . Compared with the normal group, ANF concentration in treatment hyperthyroid patients, hypothyroid patients before and after treatment was no significantly different (P>0.05), but that in hypothyroid patients before treatment was significantly decreased compared with hypothyroid patients after treatment (P 0.05), but that in hypothyroid patients before treatment was significantly decreased compared with others (P<0.01 and P<0.05). Detection of ANF and ET level may be have a role in supplementary diagnosis and curative effect observation of hyperthyroidism and hypothyroidism. (authors)

  16. Kuninglik eesti kirjandus : hommage a Cornelius Hasselblatt / Jaan Undusk

    Index Scriptorium Estoniae

    Undusk, Jaan, 1958-

    2007-01-01

    Kõne Cornelius Hasselblatti raamatu "Geschichte der estnischen Literatur. Von den Anfängen bis zum Gegenwart" / Berlin ; New-York : Walter de Gruyter, 2006) esitlusel 1. veebruaril 2007 Tallinna Kirjanike Majas

  17. Minu kirjanduslugu / Cornelius Hasselblatt

    Index Scriptorium Estoniae

    Hasselblatt, Cornelius

    2007-01-01

    Kõne Cornelius Hasselblatti raamatu "Geschichte der estnischen Literatur. Von den Anfängen bis zum Gegenwart" / Berlin ; New-York : Walter de Gruyter, 2006) esitlusel 1. veebruaril 2007 Tallinna Kirjanike Majas

  18. Germination as a processing technique for soybeans in small-scale ...

    African Journals Online (AJOL)

    charlesk

    2013-06-15

    Jun 15, 2013 ... the feed and food industry, and contains about 40% crude protein and 20% oil. ... used to reduce or eliminate the ANFs that affect protein utilisation. ..... legume seeds with food grade fungal Rhizopus oligoporus stress.

  19. New 17x17 assembly takes the heat

    International Nuclear Information System (INIS)

    Reparaz, A.; Brown, C.A. Sr.

    1992-01-01

    Advanced Nuclear Fuels' (ANF's) new 17 x 17 fuel assembly described in this article offers advanced features which provide increased thermal margins, higher burnup, responsiveness to electrical grid demands, improved seismic performance and superior corrosion resistance. (Author)

  20. A Model of Electrically Stimulated Auditory Nerve Fiber Responses with Peripheral and Central Sites of Spike Generation

    DEFF Research Database (Denmark)

    Joshi, Suyash Narendra; Dau, Torsten; Epp, Bastian

    2017-01-01

    . A single ANF is modeled as a network of two exponential integrateand-fire point-neuron models, referred to as peripheral and central axons of the ANF. The peripheral axon is excited by the cathodic charge, inhibited by the anodic charge, and exhibits longer spike latencies than the central axon......A computational model of cat auditory nerve fiber (ANF) responses to electrical stimulation is presented. The model assumes that (1) there exist at least two sites of spike generation along the ANF and (2) both an anodic (positive) and a cathodic (negative) charge in isolation can evoke a spike......; the central axon is excited by the anodic charge, inhibited by the cathodic charge, and exhibits shorter spike latencies than the peripheral axon. The model also includes subthreshold and suprathreshold adaptive feedback loops which continuously modify the membrane potential and can account for effects...

  1. Adult and Non-Formal Education: An Imperative for Human Capacity ...

    African Journals Online (AJOL)

    DR Nneka

    capacity development could be defined as the development of a workforce .... and the community and between theory and practice in Adult Education, ... ANFE provides education for women in order to empower them, enable them gain.

  2. Einsatz von unterschiedlich wärmebehandelten Sojakuchen in der ökologischen Hähnchenmast

    OpenAIRE

    Steiner, Dipl.-Ing. Thomas; Bellof, Prof. Dr. Gerhard

    2009-01-01

    In an interdisciplinary research project the following questions are to be examined: 1. How are the treatments common in practice (thermal, hydro-thermal and pressurethermal treatment) to be rated in terms of the removal of anti-nutritive active factors (ANF) in soy bean cake? 2. Which input of soy bean cake (treated) can be recommended for practical feeding in organic broiler production? Results and conclusion: 1. All treatments are sufficient for removal of ANF in soy b...

  3. Case studies in the numerical solution of oscillatory integrals

    International Nuclear Information System (INIS)

    Adam, G.

    1992-06-01

    A numerical solution of a number of 53,249 test integrals belonging to nine parametric classes was attempted by two computer codes: EAQWOM (Adam and Nobile, IMA Journ. Numer. Anal. (1991) 11, 271-296) and DO1ANF (Mark 13, 1988) from the NAG library software. For the considered test integrals, EAQWOM was found to be superior to DO1ANF as it concerns robustness, reliability, and friendly user information in case of failure. (author). 9 refs, 3 tabs

  4. Fabrication and characterization of differentiated aramid nanofibers and transparent films

    Science.gov (United States)

    Luo, Jingjing; Zhang, Meiyun; Yang, Bin; Liu, Guodong; Song, Shunxi

    2018-03-01

    Aramid nanofibers (ANFs) frequently are employed as versatile building blocks for constructing high-performance nanocomposites due to its structural and performance superiority. In this paper, the different ANFs and ANF films derived from the typical aramid yarns, chopped fiber, pulp fiber and fibrid fiber, respectively, were fabricated through deprotonation with potassium hydroxide in dimethyl sulphoxide, protonation with deionized water and vacuum-assisted filtration. The physical tests such as tensile test, ultraviolet transmittance and absorbance, thermogravimetric analysis were executed to evaluate and contrast the thermodynamic and optical performances of these differentiated ANFs and ANF films. The analytical results suggested that ANFs films prepared by the different forms of aramid macrofibers presented with differentiated properties such as mechanical behaviors, transparencies and flexibilities. And also it was found that the oversized nanofiber in length led to the formation of flocculation which was adverse for ANFs films in the formation of high strength. Whereas, small diameter just facilitated for the achievement of high stiffness and transparency. By contrast, the ANFs films made from chopped nanofiber, with aspect ratio of 200-500, exhibited good transparency, thermal stability and mechanical properties with transmittance value of 83%, TG10% around 521 °C, ultimate strength (σ) of 103.41 MPa, stiffness (E) of 4.70 GPa and strain at break of 5.56%. This work offers an alternative nanoscale building block as an effective nanofiller for preparing high-performance nanocomposites with different requirements in the potential fields such as transparent coating and flexible electrode or display materials, battery separator and microporous membrane.

  5. Increased atrial natriuretic factor receptor density in cultured vascular smooth muscle cells of the spontaneously hypertensive rat

    International Nuclear Information System (INIS)

    Khalil, F.; Fine, B.; Kuriyama, S.; Hatori, N.; Nakamura, A.; Nakamura, M.; Aviv, A.

    1987-01-01

    To explore the role of the atrial natriuretic factor (ANF) system in the pathophysiology of hypertension we examined the binding kinetics of synthetic ANF to cultured vascular smooth muscle cells (VSMCs) derived from the spontaneously hypertensive rat (SHR) and two normotensive controls-the Wistar Kyoto (WKY) and American Wistar (W). The number of maximal binding sites (Bmax) per cell (mean +/- SEM; X10(3] were: SHR = 278.0 +/- 33.0, WKY = 28.3 +/- 7.1 and W = 26.6 +/- 4.2. The differences between the SHR and normotensive strains were significant at p less than 0.001. The equilibrium dissociation constant (Kd; X 10(-9)M) was higher in SHR VSMCs (0.94 +/- 0.14) than in WKY (0.22 +/- 0.09; p less than 0.01) and W (0.39 +/- 0.14; p less than 0.02) cells. The plasma levels of the immunoreactive ANF were higher in SHR than the normotensive controls. We suggest that the relatively greater ANF receptor density in cultured VSMCs of the SHR represents a response to the in vitro environment which is relatively more deficient in ANF for VSMCs of the SHR as compared with the normotensive rats. Thus, the capacity of the SHR VSMC to regulate ANF receptor density appears to be independent of the blood pressure level

  6. Modelo en laboratorio de las reacciones de degradación de los CFC'S, HCFC'S y HFC'S en la atmósfera : su relación con la degradación de la capa de ozono y el efecto invernadero

    OpenAIRE

    Vázquez Dols, José Luis

    2011-01-01

    La concentración de ozono en la estratosfera es producto de un balance de fuerzas creadoras y destructivas. El nivel de ozono en la estratosfera debe mantenerse constante, actuando en régimen permanente. En la estratosfera la concentración de ozono varía ligeramente reflejando ligeras variaciones sobre el punto de equilibrio entre la formación y la destrucción. Estas fluctuaciones son debidas a procesos naturales tales como: ciclos estacionales, erupciones volcánicas, cambios en la intensidad...

  7. Performance analysis of the electric vehicle air conditioner by replacing hydrocarbon refrigerant

    Science.gov (United States)

    Santoso, Budi; Tjahjana, D. D. D. P.

    2017-01-01

    The thermal comfort in passenger cabins needs an automotive air-conditioning system. The electric vehicle air conditioner system is driven by an electric compressor which includes a compressor and an electric motor. Almost air-conditioning system uses CFC-12, CFC-22 and HFC-134a as refrigerant. However, CFC-12 and CFC-22 will damage the ozone layer. The extreme huge global warming potentials (GWP) values of CFC-12, CFC-22, and HFC-134a represent the serious greenhouse effect of Earth. This article shows new experimental measurements and analysis by using a mixture of HC-134 to replace HFC-134a. The result is a refrigerating effect, the coefficient of performance and energy factor increase along with cooling capacity, both for HFC-134a and HC-134. The refrigerating effect of HC-134 is almost twice higher than HFC-134a. The coefficient of performance value of HC-134 is also 36.42% greater than HFC-134a. Then, the energy factor value of HC-134 is 3.78% greater than HFC-134a.

  8. Report on a survey in fiscal 1999 for trends in policies on prevention of global warming by use of substitute fluorocarbons; 1999 nendo daitai furon no chikyu ondanka taisaku doko ni kansuru chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This paper summarizes mainly on HFC, PFC and SF{sub 6} the trends in the last one year in technologies and regulations that can make compatible the ozone layer protection and the global warming prevention. Activities of the HFC/PHC task force established jointly by TEAP and IPCC are very important in deciding the future positions of HFC, PFC and SF{sub 6}. This paper reports the status of activities taken during fiscal 1999. IPCC reviewed the method of calculating the quantity of greenhouse effect gas emission. The paper introduces from its draft the gist of calculating the discharge quantity of HFC, PFC and SF{sub 6}. Introduction is given from the HFC/PFC task force report the actual status of using coolants, foaming agents and aerosols using HFC, PFC and SF{sub 6}, and the trends of developing substitution technologies. The paper introduces a fluorocarbon destruction technology as an international trend in discharge suppression measures. The paper reports movements of COP-5 in fiscal 1999 for gases other than the three gases including HFC. Chlorobromo-methane was indicated as a new substance, and n-propyl-bromide was decided to continue with measurement of ozone destruction coefficient. (NEDO)

  9. Sync-measurement experimental study of (fluoroethane + dimethylether tetraethylene glycol), (fluoroethane + dimethylether triethylene glycol) and (fluoroethane + dimethylether diethylene glycol) systems

    International Nuclear Information System (INIS)

    Feng, Lejun; Zheng, Danxing; Huang, Weijia

    2016-01-01

    Highlights: • Three new working pairs are proposed for absorption power cycle. • Sync-measured the solubility and absorption enthalpy data at 303.15 K. • Thermokinetic experiment is consistent with the previous thermodynamics study. - Abstract: In this work, three new working pairs, {fluoroethane (HFC161) + dimethylether tetraethylene glycol (DMETEG)}, {HFC161 + dimethylether triethylene glycol (DMETrEG)} and {HFC161 + dimethylether diethylene glycol (DMEDEG)}, are proposed for absorption power cycle. The working pairs are assessed from both thermodynamics and thermokinetic perspective. By combining the microcalorimetry and isothermal synthesis methods, an experimental apparatus was developed to simultaneously obtain the microcalorimetry and vapour–liquid equilibrium data. Then, the solubility and absorption enthalpy data of the three new working pairs were sync-measured at 303.15 K by this sync-measurement experimental apparatus. The thermodynamics data indicated that the affinities of the three working pairs increased from strong to weak in the following order: HFC161 + DMETEG > HFC161 + DMETrEG > HFC161 + DMEDEG. Then the thermokinetic parameters of the absorption rate constant and activation energy were analysed based on the thermokinetic experiment at (303.15, 313.15, 323.15, and 333.15) K. As a result, the affinities of the three working pairs are consistent with the previous thermodynamics study. In addition, the intermolecular interactions within the three systems were analysed according to the intermolecular hydrogen bonds; overall, the (HFC161 + DMETEG) system is considered to be the potential option for applications.

  10. Role of Microstructure on the Performance of UHTC's

    Science.gov (United States)

    Johnson, Sylvia M.; Gasch, Matthew J.; Stackpoole, Mairead; Gusman, Mike; Thornton, Jeremy

    2009-01-01

    UHTCs, because of their refractory nature and high thermal conductivity, are candidates for use on sharp leading edges of hypersonic vehicles. NASA Ames has been investigating the use of UHTCs in the HfB2/SiC family under NASA's Fundamental Aeronautics Program. The goal of this work has been to tailor the microstructure to improve mechanical properties and the performance in reentry conditions, as determined by arcjet testing. This talk discusses results of mechanical evaluation and arcjet testing of various materials with different microstructures, including the incorporation of high-temperature fibers in these materials to improve fracture toughness. Some preliminary information on UHTC composites will also be discussed.

  11. Fundamental Thermal and Mechanical Properties of Boride Ceramics

    Science.gov (United States)

    2014-02-28

    Zr ,Y)B2 ( Zr ,Hf)B2 ( Zr ,Ti)B2 ZrB2 El ec tri ca l R es is tiv ity (µ Ω -c m ) Temperature (°C) Figure 17. Electrical resistivity as a function...family as Zr , namely Ti and Hf, had minimal effect on thermal conductivity, while others such as Nb , Ta, and W had an increasing impact based on their...diffusivity (α), heat capacity (Cp) from the NIST-JANAF tables, and bulk density (ρ) using Equation 6. (5) (6) Electrical resistivity

  12. Synthesis and characterization of hafnium carbide microcrystal chains with a carbon-rich shell via CVD

    International Nuclear Information System (INIS)

    Tian, Song; Li, Hejun; Zhang, Yulei; Liu, Sen; Fu, Yangxi; Li, Yixian; Qiang, Xinfa

    2013-01-01

    Graphical abstract: Novel HfC microcrystal chains have been synthesized via a catalyst-assisted chemical vapor deposition process. SEM results show the chains have a periodically changing diameter and a nanoscale sharpening tip. Analysis of TEM/SAED/EELS/EDX data shows the single-crystal chains grow along a [0 0 1] direction and consist of a HfC core and a thin carbon-rich shell with embedded HfC nanocrystallites surrounding the core. This work achieves the controllable preparation of nanoscale HfC sharpening tips for application as a point electron emission source and facilitates the application of HfC ultrafast laser-triggered tips in attosecond science. Highlights: •HfC microcrystal chains were synthesized by a catalyst-assisted CVD. •The chains grow along a [0 0 1] direction and have a periodically changing diameter. •Single-crystal HfC core is sheathed by a thin carbon-rich shell. •A growth mechanism model is proposed to explain the growth of microcrystal chians. •This work achieves the controllable preparation of nanoscale HfC sharpening tips. -- Abstract: Novel hafnium carbide (HfC) microcrystal chains, with a periodically changing diameter and a nanoscale sharpening tip at the chain end, have been synthesized via a catalyst-assisted chemical vapor deposition (CVD) process. The as-synthesized chains with many octahedral microcrystals have diameters of between several hundreds of nm and 6 μm and lengths of ∼500 μm. TEM diffraction studies show that the chains are single-crystalline HfC and preferentially grow along a [0 0 1] crystal orientation. TEM/EELS/EDX analysis proves the chains are composed of a HfC core and a thin (several tens of nm to 100 nm) carbon-rich shell with the embedded HfC nanocrystallites (typically below 10 nm) surrounding the core. The growth mechanism model for the chains based on the vapor–liquid–solid process, the vapor–solid process, and the HfC crystal growth characteristics is discussed

  13. Extended heart failure clinic follow-up in low-risk patients

    DEFF Research Database (Denmark)

    Schou, Morten; Gustafsson, Finn; Videbaek, Lars

    2013-01-01

    BackgroundOutpatient follow-up in specialized heart failure clinics (HFCs) is recommended by current guidelines and implemented in most European countries, but the optimal duration of HFC programmes has not been established. Nor is it known whether all or only high-risk patients, e.g. identified...... by NT-proBNP, might benefit from an extended HFC follow-up.Methods and resultsIn a multi-centre setting, we randomly assigned 921 clinically stable systolic heart failure (HF) outpatients on optimal medical therapy to undergo either an extended follow-up in the HFC (n = 461) or referral back...

  14. A phenomenological model of the electrically stimulated auditory nerve fiber: temporal and biphasic response properties

    Directory of Open Access Journals (Sweden)

    Colin eHorne

    2016-02-01

    Full Text Available We present a phenomenological model of electrically stimulated auditory nerve fibers (ANFs. The model reproduces the probabilistic and temporal properties of the ANF response to both monophasic and biphasic stimuli, in isolation. The main contribution of the model lies in its ability to reproduce statistics of the ANF response (mean latency, jitter, and firing probability under both monophasic and cathodic-anodic biphasic stimulation, without changing the model’s parameters. The response statistics of the model depend on stimulus level and duration of the stimulating pulse, reproducing trends observed in the ANF. In the case of biphasic stimulation, the model reproduces the effects of pseudomonophasic pulse shapes and also the dependence on the interphase gap (IPG of the stimulus pulse, an effect that is quantitatively reproduced. The model is fitted to ANF data using a procedure that uniquely determines each model parameter. It is thus possible to rapidly parameterize a large population of neurons to reproduce a given set of response statistic distributions.Our work extends the stochastic leaky integrate and fire (SLIF neuron, a well-studied phenomenological model of the electrically stimulated neuron. We extend the SLIF neuron so as to produce a realistic latency distribution by delaying the moment of spiking. During this delay, spiking may be abolished by anodic current. By this means, the probability of the model neuron responding to a stimulus is reduced when a trailing phase of opposite polarity is introduced. By introducing a minimum wait period that must elapse before a spike may be emitted, the model is able to reproduce the differences in the threshold level observed in the ANF for monophasic and biphasic stimuli. Thus, the ANF response to a large variety of pulse shapes are reproduced correctly by this model.

  15. Co-regulation of the atrial natriuretic factor and cardiac myosin light chain-2 genes during alpha-adrenergic stimulation of neonatal rat ventricular cells. Identification of cis sequences within an embryonic and a constitutive contractile protein gene which mediate inducible expression.

    Science.gov (United States)

    Knowlton, K U; Baracchini, E; Ross, R S; Harris, A N; Henderson, S A; Evans, S M; Glembotski, C C; Chien, K R

    1991-04-25

    To study the mechanisms which mediate the transcriptional activation of cardiac genes during alpha adrenergic stimulation, the present study examined the regulated expression of three cardiac genes, a ventricular embryonic gene (atrial natriuretic factor, ANF), a constitutively expressed contractile protein gene (cardiac MLC-2), and a cardiac sodium channel gene. alpha 1-Adrenergic stimulation activates the expression and release of ANF from neonatal ventricular cells. As assessed by RNase protection analyses, treatment with alpha-adrenergic agonists increases the steady-state levels of ANF mRNA by greater than 15-fold. However, a rat cardiac sodium channel gene mRNA is not induced, indicating that alpha-adrenergic stimulation does not lead to an increase in the expression of all cardiac genes. Studies employing a series of rat ANF luciferase and rat MLC-2 luciferase fusion genes identify 315- and 92-base pair cis regulatory sequences within an embryonic gene (ANF) and a constitutively expressed contractile protein gene (MLC-2), respectively, which mediate alpha-adrenergic-inducible gene expression. Transfection of various ANF luciferase reporters into neonatal rat ventricular cells demonstrated that upstream sequences which mediate tissue-specific expression (-3003 to -638) can be segregated from those responsible for inducibility. The lack of inducibility of a cardiac Na+ channel gene, and the segregation of ANF gene sequences which mediate cardiac specific from those which mediate inducible expression, provides further insight into the relationship between muscle-specific and inducible expression during cardiac myocyte hypertrophy. Based on these results, a testable model is proposed for the induction of embryonic cardiac genes and constitutively expressed contractile protein genes and the noninducibility of a subset of cardiac genes during alpha-adrenergic stimulation of neonatal rat ventricular cells.

  16. Overview of hybrid fiber-coaxial network deployment in the deregulated UK environment

    Science.gov (United States)

    Cox, Alan L.

    1995-11-01

    Cable operators in the U.K. enjoy unprecedented license to construct networks and operate cable TV and telecommunications services within their franchise areas. In general, operators have built hybrid-fiber-coax (HFC) networks for cable TV in parallel with fiber-copper-pair networks for telephony. The commonly used network architectures are reviewed, together with their present and future capacities. Despite this dual-technology approach, there is considerable interest in the integration of telephony services onto the HFC network and the development of new interactive services for which HFC may be more suitable than copper pairs. Certain technological and commercial developments may have considerable significance for HFC networks and their operators. These include the digitalization of TV distribution and the rising demand for high-rate digital access lines. Possible scenarios are discussed.

  17. The Effects of Water Spray Cooling in Conjunction with Halogenated Extinguishants on Hydrogen Fluoride Generation and Decay

    National Research Council Canada - National Science Library

    Burch, Ian

    2007-01-01

    The halogenated extinguishants Halon 1301, HFC-227ea (FM200) and NAF-S-III used within Royal Australian Navy vessels for total flooding fire suppression applications have hydrogen fluoride (HF) toxicity concerns...

  18. Linking Halal Food Certification and Business Performance

    DEFF Research Database (Denmark)

    Ab Talib, Mohamed Syazwan; Chin, Thoo Ai; Fischer, Johan

    2017-01-01

    , operational performance mediates the relationship between HFC and financial performance. Altogether, this signifies that Halal food certificate implementation positively influences business performance. Practical implications By linking HFC and business performance, managers may be aware of the significant......Purpose The purpose of this paper is to explore the relationship between Halal food certification (HFC) and business performance. This study argues that Halal food certificate implementation positively influences business performance. Design/methodology/approach A total of 210 Halal certified food...... role of HFC in influencing operational and financial performance. It would entice more food companies to become Halal certified that opens up an opportunity to a lucrative Halal food industry. It also empirically justifies that a religion-based food certification has the ability to influence business...

  19. Transitioning to Low-GWP Alternatives in Motor Vehicle Air Conditioning Systems

    Science.gov (United States)

    This fact sheet provides information on low-GWP alternatives in newly manufactured motor vehicle air conditioning systems. It discusses HFC alternatives, market trends, challenges to market entry for alternatives, and potential solutions.

  20. 75 FR 57669 - Mandatory Reporting of Greenhouse Gases

    Science.gov (United States)

    2010-09-22

    ... Mandatory Reporting of Greenhouse Gases AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: This action amends the Final Mandatory Reporting of Greenhouse Gases Rule to require reporters... Numbers GHG greenhouse gas GHGRP Greenhouse Gas Reporting Program HCFC hydrochlorofluorocarbon HFC...

  1. 40 CFR Appendix D to Subpart G of... - Substitutes Subject to Use Restrictions and Unacceptable Substitutes

    Science.gov (United States)

    2010-07-01

    ... the following criteria, derived from Society of Automotive Engineers (SAE) standards and recommended... Substitutes] Application Substitute Decision Conditions Comments Electronics Cleaning w/CFC-113 and MCF HFC... Sector [Acceptable Subject to Narrowed Use Limits] Application Substitute Decision Comments Electronics...

  2. Rate Constant and Temperature Dependence for the Reaction of Hydroxyl Radicals with 2-Flouropropane (FC-281ea) and Comparison with an Estimated Rate Constant

    Science.gov (United States)

    DeMore, W.; Wilson, E., Jr.

    1998-01-01

    Relative rate experiments were used to measure the rate constant and temperature dependence of the reaction of OH radicals with 2-fluoropropane (HFC-281ea), using ethane, propane, ethyl chloride as reference standards.

  3. Linking Halal Food Certification and Business Performance

    DEFF Research Database (Denmark)

    Ab Talib, Mohamed Syazwan; Chin, Thoo Ai; Fischer, Johan

    2017-01-01

    role of HFC in influencing operational and financial performance. It would entice more food companies to become Halal certified that opens up an opportunity to a lucrative Halal food industry. It also empirically justifies that a religion-based food certification has the ability to influence business...... manufacturing companies in Malaysia participated in the study. Data were gathered through a structured questionnaire and were analysed using partial least squares structural equation modelling technique. Findings The study proved that HFC has a positive relationship with operational performance. Additionally......, operational performance mediates the relationship between HFC and financial performance. Altogether, this signifies that Halal food certificate implementation positively influences business performance. Practical implications By linking HFC and business performance, managers may be aware of the significant...

  4. Improvement of the Material's Mechanical Characteristics using ...

    African Journals Online (AJOL)

    pc

    2018-03-05

    Mar 5, 2018 ... to Hardening Process Control (HPC) in order to improvement of the material's ... particular circumstances of the models characteristics used and the exact definition ..... In the case of simulation and testing in Matlab of the HFC.

  5. Effects of dietary fermentation concentrate of Hericium caput-medusae (Bull.:Fr.) Pers. on growth performance, digestibility, and intestinal microbiology and morphology in broiler chickens.

    Science.gov (United States)

    Shang, Hong Mei; Song, Hui; Xing, Ya Li; Niu, Shu Li; Ding, Guo Dong; Jiang, Yun Yao; Liang, Feng

    2016-01-15

    The present study was undertaken to investigate the effects of fermentation concentrate of Hericium caput-medusae (Bull.:Fr.) Pers. (HFC) on growth performance, digestibility, intestinal microbiology, and intestinal morphology in broiler chickens. A total of 600 male Arbor Acres broilers were randomly divided into five dietary treatments (20 broilers per pen with six pens per treatment): CON (basal diet), ANT (basal diet supplemented with 5 mg kg(-1) flavomycin) and HFC (basal diet supplemented with 6, 12, and 18 g kg(-1) HFC). The experimental lasted for 42 days. The results revealed that the average daily gain [linear (L), P < 0.01; quadratic (Q), P < 0.01] of broilers increased when the HFC levels increased during the starter (days 1-21), finisher (days 22-42), and the overall experiment period (days 1 to 42). In the small intestinal digesta and the caecum digesta, the Escherichia coli count (L, P < 0.05; Q, P < 0.001) decreased while the Lactobacilli count (L, P < 0.01; Q, P < 0.001) and Bifidobacteria count (L, P < 0.001; Q, P < 0.001) increased when the HFC levels increased. The crude protein digestibility of broilers (L, P < 0.01; Q, P < 0.001) increased when the HFC levels increased. In the duodenum, jejunum, and ileum of broilers, the villus height and villus height to crypt depth ratio (L, P < 0.001; Q, P < 0.001) increased when the HFC levels increased. Dietary supplementation with HFC increased gut Lactobacilli and Bifidobacteria counts and inhibited E. coli growth, improved nutrient utilisation and intestine villus structure, and thus improved the growth of broilers. © 2015 Society of Chemical Industry.

  6. The endocrine system in space flight

    Science.gov (United States)

    Leach, C. S.; Johnson, P. C.; Cintron, N. M.

    1988-01-01

    A trial natriuretic factor (ANF), a hormone recently shown to regulate sodium and water excretion, has been measured in blood specimens obtained during flight. After 30 or 42 h of weightlessness, mean ANF was elevated. After 175 or 180 h, ANF has increased by 59 percent, and it changed little between that time and soon after landing. There is probably an increase in ANF early inflight associated with the fluid shift, followed by a compensatory decrease in blood volume. Increased renal blood flow may cause the later ANF decrease. Erythropoietin (Ep), a hormone involved in the control of red blood cell proudction, was measured in blood samples taken during the first Spacelab mission and was significantly decreased on the second day of flight, suggesting also an increase in renal blood flow. Spacelab-2 investigators report that the active vitamin D metabolite 1 alpha, 25-dihydroxyvitamin D-3 increased early in the flight, indicating that a stimulus for increased bone resorption occurs by 30 h after launch.

  7. Effects on auditory-nerve fibers of opening the otic capsule at the apex of the chinchilla cochlea

    Science.gov (United States)

    Recio-Spinoso, Alberto; Temchin, Andrei N.; Ruggero, Mario A.

    2015-12-01

    Vibration responses to clicks measured at the apex of chinchilla cochleae with open otic capsules have onsets much shorter than those of responses of auditory-nerve fibers (ANFs) corrected for synaptic and neural delays. Apical vibration responses to tones in open cochleae also differ in other respects from the responses to tones of ANFs with low characteristic frequency (CF) in normal chinchilla cochleae. To further specify the origin(s) of these differences, we recorded from chinchilla ANFs after delicately opening a small hole in the otic capsule overlying scala vestibuli in the cochlear apex. In those cochleae, the earliest ANF responses to clicks are often evoked by condensation (rather than rarefaction) clicks and responses to tones often exhibit level-dependent phase changes different from those in normal cochleae. These findings are largely consistent with, and seem to account for, apical vibration responses of cochleae with open otic capsules. An unexpected finding is that the tuning curves of ANFs with moderately high CF and normal CF thresholds often had hypersensitive tails.

  8. The endocrine system in space flight

    Science.gov (United States)

    Leach, C. S.; Johnson, P. C.; Cintron, N. M.

    Hormones are important effectors of the body's response to microgravity in the areas of fluid and electrolyte metabolism, erythropoiesis, and calcium metabolism. For many years antidiuretic hormone, cortisol and aldosterone have been considered the hormones most important for regulation of body fluid volume and blood levels of electrolytes, but they cannot account totally for losses of fluid and electrolytes during space flight. We have now measured atrial natriuretic factor (ANF), a hormone recently shown to regulate sodium and water excretion, in blood specimens obtained during flight. After 30 or 42 h of weightlessness, mean ANF was elevated. After 175 or 180 h, ANF had decreased by 59%, and it changed little between that time and soon after landing. There is probably an increase in ANF early inflight associated with the fluid shift, followed by a compensatory decrease in blood volume. Increased renal blood flow may cause the later ANF decrease. Erythropoietin (Ep), a hormone involved in the control of red blood cell production, was measured in blood samples taken during the first Spacelab mission and was significantly decreased on the second day of flight, suggesting also an increase in renal blood flow. Spacelab-2 investigators report that the active vitamin D metabolite 1α, 25-dihydroxyvitamin D 3 increased early in the flight, indicating that a stimulus for increased bone resorption occurs by 30 h after launch.

  9. Fast negative feedback enables mammalian auditory nerve fibers to encode a wide dynamic range of sound intensities.

    Directory of Open Access Journals (Sweden)

    Mark Ospeck

    Full Text Available Mammalian auditory nerve fibers (ANF are remarkable for being able to encode a 40 dB, or hundred fold, range of sound pressure levels into their firing rate. Most of the fibers are very sensitive and raise their quiescent spike rate by a small amount for a faint sound at auditory threshold. Then as the sound intensity is increased, they slowly increase their spike rate, with some fibers going up as high as ∼300 Hz. In this way mammals are able to combine sensitivity and wide dynamic range. They are also able to discern sounds embedded within background noise. ANF receive efferent feedback, which suggests that the fibers are readjusted according to the background noise in order to maximize the information content of their auditory spike trains. Inner hair cells activate currents in the unmyelinated distal dendrites of ANF where sound intensity is rate-coded into action potentials. We model this spike generator compartment as an attenuator that employs fast negative feedback. Input current induces rapid and proportional leak currents. This way ANF are able to have a linear frequency to input current (f-I curve that has a wide dynamic range. The ANF spike generator remains very sensitive to threshold currents, but efferent feedback is able to lower its gain in response to noise.

  10. The opposing effects of calmodulin, adenosine 5 prime -triphosphate, and pertussis toxin on phorbol ester induced inhibition of atrial natriuretic factor stimulated guanylate cyclase in SK-NEP-1 cells

    Energy Technology Data Exchange (ETDEWEB)

    Sekiya, M.; Frohlich, E.D.; Cole, F.E. (Alton Ochsner Medical Foundation, New Orleans, LA (USA))

    1991-01-01

    In the present study, we investigated the effects of calmodulin, adenosine 5{prime}-triphosphate (ATP) and pertussis toxin (PT) on phorbol ester (PMA) induced inhibition of ANF-stimulated cyclic GMP formation in cells from the human renal cell line, SK-NEP-1. PMA inhibited ANF-stimulated guanylate cyclase activity in particulate membranes by about 65%. Calmodulin reversed this inhibition in a dose dependent manner. ATP potentiated Mg++ but not Mn++ supported guanylate cyclase activity. In PMA treated membranes, ATP potentiating effects were abolished. PMA also inhibited ANF-stimulated cGMP accumulation, but pretreatment with PT prevented this PMA inhibition. PT did not affect basal or ANF-stimulated cGMP accumulation. In conclusion, these results demonstrated that PMA inhibited ANF stimulation of particulate guanylate cyclase in opposition to the activating effects of calmodulin or ATP in SK-NEP-1 cells. The protein kinase C inhibitory effects appeared to be mediated via a PT-sensitive G protein.

  11. Pertussis toxin treatment does not block inhibition by atrial natriuretic factor of aldosterone secretion in cultured bovine zona glomerulosa cells

    International Nuclear Information System (INIS)

    De Lean, A.; Cantin, M.

    1986-01-01

    The authors have previously reported that atrial natriuretic factor (ANF) potently inhibits PGE or forskolin-stimulation aldosterone secretion in bovine zona glomerulosa (ZG) by acting through specific high affinity receptors. In order to evaluate the functional role of the regulatory protein N/sub i/ and the inhibition of adenylate cyclase activity (AC) in ZG, the authors have studied the effect of treatment with PT on inhibition by ANF of aldosterone production. Primary cultures of ZG were treated for 18 hours in serum-free F12 medium with (0-100 ng/ml PT). No effect of PT pretreatment was observed either on basal, PGE-stimulated or ANF-inhibited levels of steroidogenesis. When membranes prepared from control ZG were ADP-ribosylated with [ 32 P] NAD in the presence of PT, two toxin-specific bands with 39 Kd and 41 Kd were documented on SDS gel. Cell pretreatment with as low as 1 ng/ml drastically reduced further labelling of these two bands while higher doses completely abolished them. Since PT treatment covalently modifies completely the toxin substrate without altering ANF inhibition of adrenal steroidogenesis, the authors conclude that N/sub i/ is not involved in the mode of action of ANF on aldosterone production

  12. Influence of boron vacancies on phase stability, bonding and structure of MB2 (M  =  Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W) with AlB2 type structure

    International Nuclear Information System (INIS)

    Dahlqvist, Martin; Rosen, Johanna; Jansson, Ulf

    2015-01-01

    Transition metal diborides in hexagonal AlB 2 type structure typically form stable MB 2 phases for group IV elements (M  =  Ti, Zr, Hf). For group V (M  =  V, Nb, Ta) and group VI (M  =  Cr, Mo, W) the stability is reduced and an alternative hexagonal rhombohedral MB 2 structure becomes more stable. In this work we investigate the effect of vacancies on the B-site in hexagonal MB 2 and its influence on the phase stability and the structure for TiB 2 , ZrB 2 , HfB 2 , VB 2 , NbB 2 , TaB 2 , CrB 2 , MoB 2 , and WB 2 using first-principles calculations. Selected phases are also analyzed with respect to electronic and bonding properties. We identify trends showing that MB 2 with M from group V and IV are stabilized when introducing B-vacancies, consistent with a decrease in the number of states at the Fermi level and by strengthening of the B–M interaction. The stabilization upon vacancy formation also increases when going from M in period 4 to period 6. For TiB 2 , ZrB 2 , and HfB 2 , introduction of B-vacancies have a destabilizing effect due to occupation of B–B antibonding orbitals close to the Fermi level and an increase in states at the Fermi level. (paper)

  13. FY 1998 annual summary report on recent trends of global warming prevention measures with fluorochlorohydrocarbon alternatives; 1998 nendo daitia furon no chikyu ondanka taisaku doko ni kansuru chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    Described herein are the recent trends of the ozone layer protection and global warming prevention measures. Latest international information has been collected by attending the 10th Meeting of the Party of Montreal Protocol, and the 17th and 18th Open Ended Working Group. The important decisions made so far are investigation on the novel ozone layer destruction substances, requirement of studying on decommissioning Halon facilities, collection of information of HFC and PFC, and reporting to IPCC. Information regarding regulation trends of HFC, PFC and SF{sub 6} are collected by attending the COP-4 meeting and the preparatory meetings therefor. The report on these 3 substances will be completed in July or so, 1999. The trends of technical development in HCFC alternatives in refrigeration and blowing sectors were investigated. HFC-245fa and HFC-365mfc are introduced. Also introduced is latest information regarding the emission estimation and control measures of HFC in USA and UK, emission control measures of SF{sub 6} in USA and Japan, and techniques for destruction of CFC and the like, which could be the basic techniques for controlling diffusion of HFC. The CFC phase-out programs of China, the biggest ozone layer destruction substance (e.g., CFC) consuming country, are also outlined. (NEDO)

  14. Cooling performance of R510A in domestic water purifiers

    International Nuclear Information System (INIS)

    Park, Ki Jung; Lee, Yo Han; Jung, Dong Soo

    2010-01-01

    Cooling performance of R510A is examined both numerically and experimentally in an effort to replace HFC134a in the refrigeration system of domestic water purifiers. Although the use of HFC134a is currently dominant, it is being phased out in Europe and most developed countries due to its high potential contribution to global warming. To solve this problem, cycle simulation and experimental measurements are conducted with a new refrigerant mixture of 88%RE170/12%R600a using actual domestic water purifiers. This mixture has been recently numbered and listed as R510A by ASHRAE. Test results show that, due to the small internal volume of the refrigeration system of the domestic water purifiers, system performance with R510A is greatly influenced by the amount of charge. With the optimum charge amount of 20 to 21 g, approximately 50% that of HFC134a, the energy consumption of R510A is 22.3% lower than that of HFC134a. The compressor discharge temperature of R510A is 3.7 .deg. C lower than that of HFC134a at the optimum charge. Overall, R510A, a new, long term, and environmentally safe refrigerant, is a good alternative for HFC134a. Furthermore, it requires only minor changes in the refrigeration system of the domestic water purifiers

  15. Changes in plasma atrial natriuretic factor in patients with idiopathic atrial fibrillation

    International Nuclear Information System (INIS)

    Du Tongxin; Xia Xiaojie; Qu Wei; Wang Shukui; Sun Junjiang

    2002-01-01

    To observe the changes in plasma atrial natriuretic factor (AFN) in patients with idiopathic atrial fibrillation and investigate its mechanism, plasma ANF, platelet count and hematocrit were detected in 21 cases with transient idiopathic atrial fibrillation (group A, A1 representing attack, while A2 termination), 28 with persistent idiopathic atrial fibrillation (group B), 27 suffered from rheumatic heart disease with mitral stenosis and persistent atrial fibrillation (group C), 32 with transient supraventricular tachycardia (group D) and 20 normal controls (group E). It was found that the level of ANF was significantly higher in patients with attacking transient idiopathic atrial fibrillation than that in group A2, D and E (P 0.05), while there was significant difference in hematocrit in group A1 compared with group A2, D, E (P < 0.01). It suggested that ANF and hematocrit play an important role in the attack of idiopathic atrial fibrillation

  16. Analysis and Design of Notch Filter-Based PLLs for Grid-Connected Applications Electric Power Systems Research

    DEFF Research Database (Denmark)

    Khazraj, Hesam; Silva, Filipe Miguel Faria da; Bak, Claus Leth

    2017-01-01

    Using multiple notch filters (NFs) inside the control loop of a standard PLL is a basic strategy to improve its filtering capability. Often, adaptive NFs (ANFs) are employed for this purpose as they can block the disturbance components even under off-nominal grid frequencies. This advantage...... is at the cost of a rather considerable increase in the PLL implementation complexity and computational effort, particularly when ANFs have their own frequency estimation mechanism. The non-adaptive NFs (NNFs), contrary to ANFs, are easy to implement. They, however, have received a little attention in PLL...... applications. Therefore, their performance characteristics are rather unclear. To gain insight about the advantages and disadvantages of NNF-based PLLs (NNF-PLLs), analysis and design of these PLLs is conducted in this paper. This procedure includes: (1) selecting the appropriate number of NNFs inside the PLL...

  17. Abundance and sources of atmospheric halocarbons in the Eastern Mediterranean

    Science.gov (United States)

    Schoenenberger, Fabian; Henne, Stephan; Hill, Matthias; Vollmer, Martin K.; Kouvarakis, Giorgos; Mihalopoulos, Nikolaos; O'Doherty, Simon; Maione, Michela; Emmenegger, Lukas; Peter, Thomas; Reimann, Stefan

    2018-03-01

    A wide range of anthropogenic halocarbons is released to the atmosphere, contributing to stratospheric ozone depletion and global warming. Using measurements of atmospheric abundances for the estimation of halocarbon emissions on the global and regional scale has become an important top-down tool for emission validation in the recent past, but many populated and developing areas of the world are only poorly covered by the existing atmospheric halocarbon measurement network. Here we present 6 months of continuous halocarbon observations from Finokalia on the island of Crete in the Eastern Mediterranean. The gases measured are the hydrofluorocarbons (HFCs), HFC-134a (CH2FCF3), HFC-125 (CHF2CF3), HFC-152a (CH3CHF2) and HFC-143a (CH3CF3) and the hydrochlorofluorocarbons (HCFCs), HCFC-22 (CHClF2) and HCFC-142b (CH3CClF2). The Eastern Mediterranean is home to 250 million inhabitants, consisting of a number of developed and developing countries, for which different emission regulations exist under the Kyoto and Montreal protocols. Regional emissions of halocarbons were estimated with Lagrangian atmospheric transport simulations and a Bayesian inverse modeling system, using measurements at Finokalia in conjunction with those from Advanced Global Atmospheric Gases Experiment (AGAGE) sites at Mace Head (Ireland), Jungfraujoch (Switzerland) and Monte Cimone (Italy). Measured peak mole fractions at Finokalia showed generally smaller amplitudes for HFCs than at the European AGAGE sites except for periodic peaks of HFC-152a, indicating strong upwind sources. Higher peak mole fractions were observed for HCFCs, suggesting continued emissions from nearby developing regions such as Egypt and the Middle East. For 2013, the Eastern Mediterranean inverse emission estimates for the four analyzed HFCs and the two HCFCs were 13.9 (11.3-19.3) and 9.5 (6.8-15.1) Tg CO2eq yr-1, respectively. These emissions contributed 16.8 % (13.6-23.3 %) and 53.2 % (38.1-84.2 %) to the total inversion

  18. Interaction of cadmium with atrial natriuretic factor receptors: Ligand binding and cellular processing

    International Nuclear Information System (INIS)

    Giridhar, J.; Rathinavelu, A.; Isom, G.E.

    1990-01-01

    ANF is a peptide hormone secreted by the heart and produces potent diuresis and vascular smooth muscle relaxation. It is well known that Cd produces cardiovascular toxicity and is implicated in the pathogenesis of hypertension. Hence the effects of Cd on ANF receptor dynamics and ligand binding were studied in PC12 cells. Receptor internalization using 125 I-ANF as the ligand at 37 degree C displayed a decrease in endocytic rate constants (ERC) when either preincubated with Cd (500 μM for 30 min, ERC = 0.183/min) or coincubated with Cd (500 μM, ERC = 0.196) when compared to control value (ERC = 0.259/min). Ligand binding ( 125 I-ANF) was changed by Cd as reflected by a decrease in the number of binding sites/cell in both Cd preincubated (Kd = 3.81 x 10 -10 M, B max = 1 x 10 -10 M, binding sites/cell = 9333) and coincubated cells (Kd = 1.76 x 10 -10 M, B max = 3.92 x 10 -11 M, binding sites/cell = 5960) from control (Kd = 3.87 x 10 -10 M, B max = 9.58 x 10 -11 M, binding sites/cell = 12141). Photoaffinity labelling with 125 I-ANF as the ligand was used to measure receptor subtype binding. Coincubation of cells with Cd (500 μM) and ligand decreased both high and low mol. wt. receptor binding, whereas preincubation with Cd (500μM) for 60 min produced a slight decrease in binding of both receptor subtypes. These results indicate that the cardiovascular toxicity of Cd may be partially mediated by altered ANF receptor function

  19. Effect of Interleukin 1b on rat thymus microenvironment

    Directory of Open Access Journals (Sweden)

    M Artico

    2009-12-01

    Full Text Available The effect of interleukin 1b on the thymus of control and chemically sympathectomized adult and aged rats was studied with the aim of assessing the importance of adrenergic nerve fibres (ANF in the regulation of some immunological functions.The whole thymus was removed from normal, sympathectomized (with the neurotoxin 6-OH-dopamine and treated (interleukin 1b rats. Thymic slices were stained with eosin orange (for the recognition of microanatomical details of the thymic microenvironment and with Bodian’s method for staining of nerve fibres. Histofluorescence microscopy was employed for staining ANF and immunofluorescence was used for detecting NPY-like immunoreactivity. All images were submitted to quantitative morphometrical analysis and statistical analysis of data. Moreover, the amount of proteins and noradrenaline was measured on thymic homogenates. The results indicate that in normal conditions the formation of the thymic nerve plexi in the rat is complex: the majority of ANF are destroyed after chemical sympathectomy with 6-OH-dopamine and do not change after treatment with interleukin 1b; on the contrary, treatment with interleukin 1b induces substantial changes in the fresh weight of the thymus, the thymic microenvironment, thymic nerve fibers, ANF, NPY-like positive nerve fibres, and on the total amount of proteins and noradrenaline in rat thymic tissue homogenates.Immunostimulation with interleukin 1b induces substantial changes in the whole thymus, in its microenvironment and in ANF and NPY-like nerve fibres. After chemical sympathectomy, no significant immune response was evoked by interleukin 1b, since the majority of ANF was destroyed by chemical sympathectomy.

  20. Left ventricular wall stress and sarcoplasmic reticulum Ca(2+)-ATPase gene expression in renal hypertensive rats: dose-dependent effects of ACE inhibition and AT1-receptor blockade.

    Science.gov (United States)

    Zierhut, W; Studer, R; Laurent, D; Kästner, S; Allegrini, P; Whitebread, S; Cumin, F; Baum, H P; de Gasparo, M; Drexler, H

    1996-05-01

    Cardiac hypertrophy is associated with altered Ca2+ handling and may predispose to the development of LV dysfunction and cardiac failure. At the cellular level, the re-expression of ANF represents a well-established marker of myocyte hypertrophy while the decreased expression of the sarcoplasmatic reticulum (SR) Ca(2+)-ATPase is thought o play a crucial role in the alterations of Ca2+ handling and LV function. We assessed the dose-dependent effect of chronic ACE inhibition or AT1 receptor blockade on cardiac function in relation to the cardiac expression of the SR Ca(2+)-ATPase and ANF. Renal hypertensive rats (2K-1C) were treated for 12 weeks with three different doses of the ACE inhibitor benazepril, the AT1-receptor antagonist valsartan (each drug 0.3, 3, and 10 mg/kg per day i.p.) or placebo. LV dimensions, hypertrophy and wall stress were determined in vivo by magnetic resonance imaging and the gene expressions of ANF and SR Ca(2+)-ATPase were quantified by Northern blot. Low doses of both drugs did not affect blood pressure, hypertrophy, systolic wall stress and the ANF and SR Ca(2+)-ATPase gene expression. High doses of each drug reduced systolic blood pressure, wall stress, and LV hypertrophy to a similar extent and to values comparable to normotensive, age-matched rats. In addition, high dose treatment reduced LV end-systolic and end-diastolic volume as compared to untreated 2K-1C animals and normalized the mRNA levels of both ANF and SR Ca(2+)-ATPase (as compared to normotensive animals). We conclude that in this model, high doses of ACE inhibition and AT1-receptor blockade are necessary to normalize systolic blood pressure, LV hypertrophy and systolic LV wall stress which, in turn, is associated with restoration of a normal cardiac phenotype with respect to SR Ca(2+)-ATPase and ANF and normalization of cardiac function.

  1. Las hornblenditas, gabros y dioritas del Macizo del Montnegre (Barcelona, Cordilleras Costero Catalanas)

    OpenAIRE

    Butjosa, Lidia; Enrique Gisbert, Pere; Galán, Gumer

    2013-01-01

    En relación con los granitos tardihercínicos calcoalcalinos del Macizo del Montnegre aparecen rocas ultrabásicas-básicas a intermedias. Las más básicas son hornblenditas olivínicas, con espinela, clinopiroxeno, ortopiroxeno, anfíboles de varios tipos y flogopita. Hay además melagabros-gabros hornbléndicos y leucogabros, estos últimos con anfíbol minoritario. Las rocas más ácidas son cuarzodioritas y cuarzomonzodioritas biotítico-hornbléndicas, con cristales relictos de clino...

  2. Las hornblenditas,gabros y dioritas del Macizo del Montnegre (Barcelona, Cordilleras costero catalanas)

    OpenAIRE

    Butjosa, Lidia; Enrique, P. (Pere); Galán, Gumer

    2013-01-01

    En relación con los granitos tardihercínicos calcoalcalinos del Macizo del Montnegre aparecen rocas ultrabásicas-básicas a intermedias. Las más básicas son hornblenditas olivínicas, con espinela, clinopiroxeno, ortopiroxeno, anfíboles de varios tipos y flogopita. Hay además melagabros-gabros hornbléndicos y leucogabros, estos últimos con anfíbol minoritario. Las rocas más ácidas son cuarzodioritas y cuarzomonzodioritas biotítico-hornbléndicas, con cristales relictos de clinopiroxeno y ortopir...

  3. Nontrivial asymptotically nonfree gauge theories and dynamical unification of couplings

    International Nuclear Information System (INIS)

    Kubo, J.

    1995-01-01

    Evidence for the nontriviality of asymptotically nonfree (ANF) Yang-Mills theories is found on the basis of optimized perturbation theory. It is argued that these theories with matter couplings can be made nontrivial by means of the reduction of couplings, leading to the idea of the dynamical unification of couplings (DUC). The second-order reduction of couplings in the ANF SU(3)-gauged Higgs-Yukawa theory, which is assumed to be nontrivial here, is carried out to motivate independent investigations on its nontriviality and DUC

  4. Revisión de la distribución de Hyalella Smith, 1874 (Crustacea, Amphipoda) en la Patagonia e islas adyacentes Revision of the distribution of Hyalella Smith, 1874 (Crustacea, Amphipoda) in Patagonia and adjacent islands

    OpenAIRE

    Patricio De los Ríos-Escalante; Andrés Mansilla; Christopher B Anderson

    2012-01-01

    Se realiza una revisión de las especies de anfípodos del género Hyalella en aguas continentales de la Patagonia, isla Tierra del Fuego, Reserva de la Biosfera de Cabo de Hornos e islas adyacentes (38-54°S). Esta zona austral presenta numerosos tipos de ambientes acuáticos continentales como lagos, humedales y arroyos, y las principales especies en ambientes bentónicos corresponden a anfípodos del género Hyalella. La bibliografía menciona la presencia de H. costera, H. chiloensis, H. falklande...

  5. Revisión de la distribución de Hyalella Smith, 1874 (Crustacea, Amphipoda) en la Patagonia e islas adyacentes

    OpenAIRE

    De los Ríos-Escalante,Patricio; Mansilla,Andrés; Anderson,Christopher B

    2012-01-01

    Se realiza una revisión de las especies de anfípodos del género Hyalella en aguas continentales de la Patagonia, isla Tierra del Fuego, Reserva de la Biosfera de Cabo de Hornos e islas adyacentes (38-54°S). Esta zona austral presenta numerosos tipos de ambientes acuáticos continentales como lagos, humedales y arroyos, y las principales especies en ambientes bentónicos corresponden a anfípodos del género Hyalella. La bibliografía menciona la presencia de H. costera, H. chiloensis, H. falklande...

  6. Detección, identificación, intervención y gestión del amianto existente en los edificios de la UPCT

    OpenAIRE

    Sánchez Conesa, Tomás

    2012-01-01

    El amianto o asbesto (denominaciones de origen griego, cuyo significado es amianto‐incorruptible y asbestos‐inextinguible) es una sustancia mineral natural (silicato fibroso), con dos grupos mineralógicos: serpentinos y anfíboles, que se extrae de la roca en minas de distintos países, principalmente, Canadá, Rusia, Brasil, Australia y algunas zonas de África. El crisotilo pertenece al grupo de las serpentinas; los otros tipos de amianto son del grupo de los anfíboles. Las rocas...

  7. Health facility committees and facility management - exploring the nature and depth of their roles in Coast Province, Kenya

    Directory of Open Access Journals (Sweden)

    Kabare Margaret

    2011-09-01

    Full Text Available Abstract Background Community participation has been emphasized internationally as a way of enhancing accountability, as well as a means to enhance health goals in terms of coverage, access and effective utilization. In rural health facilities in Kenya, initiatives to increase community accountability have focused on Health Facility Committees (HFCs. In Coast Province the role of HFCs has been expanded with the introduction of direct funding of rural facilities. We explored the nature and depth of managerial engagement of HFCs at the facility level in two rural districts in this Coastal setting, and how this has contributed to community accountability Methods We conducted structured interviews with the health worker in-charge and with patients in 30 health centres and dispensaries. These data were supplemented with in-depth interviews with district managers, and with health workers and HFC members in 12 health centres and dispensaries. In-depth interviews with health workers and HFC members included a participatory exercise to stimulate discussion of the nature and depth of their roles in facility management. Results HFCs were generally functioning well and played an important role in facility operations. The breadth and depth of engagement had reportedly increased after the introduction of direct funding of health facilities which allowed HFCs to manage their own budgets. Although relations with facility staff were generally good, some mistrust was expressed between HFC members and health workers, and between HFC members and the broader community, partially reflecting a lack of clarity in HFC roles. Moreover, over half of exit interviewees were not aware of the HFC's existence. Women and less well-educated respondents were particularly unlikely to know about the HFC. Conclusions There is potential for HFCs to play an active and important role in health facility management, particularly where they have control over some facility level resources

  8. Health facility committees and facility management - exploring the nature and depth of their roles in Coast Province, Kenya.

    Science.gov (United States)

    Goodman, Catherine; Opwora, Antony; Kabare, Margaret; Molyneux, Sassy

    2011-09-22

    Community participation has been emphasized internationally as a way of enhancing accountability, as well as a means to enhance health goals in terms of coverage, access and effective utilization. In rural health facilities in Kenya, initiatives to increase community accountability have focused on Health Facility Committees (HFCs). In Coast Province the role of HFCs has been expanded with the introduction of direct funding of rural facilities. We explored the nature and depth of managerial engagement of HFCs at the facility level in two rural districts in this Coastal setting, and how this has contributed to community accountability We conducted structured interviews with the health worker in-charge and with patients in 30 health centres and dispensaries. These data were supplemented with in-depth interviews with district managers, and with health workers and HFC members in 12 health centres and dispensaries. In-depth interviews with health workers and HFC members included a participatory exercise to stimulate discussion of the nature and depth of their roles in facility management. HFCs were generally functioning well and played an important role in facility operations. The breadth and depth of engagement had reportedly increased after the introduction of direct funding of health facilities which allowed HFCs to manage their own budgets. Although relations with facility staff were generally good, some mistrust was expressed between HFC members and health workers, and between HFC members and the broader community, partially reflecting a lack of clarity in HFC roles. Moreover, over half of exit interviewees were not aware of the HFC's existence. Women and less well-educated respondents were particularly unlikely to know about the HFC. There is potential for HFCs to play an active and important role in health facility management, particularly where they have control over some facility level resources. However, to optimise their contribution, efforts are needed to

  9. Severe symptoms of short tear break-up time dry eye are associated with accommodative microfluctuations

    Directory of Open Access Journals (Sweden)

    Kaido M

    2017-05-01

    Full Text Available Minako Kaido,1,2 Motoko Kawashima,1 Reiko Ishida,1,3 Kazuo Tsubota1 1Department of Ophthalmology, Keio University School of Medicine, Tokyo, 2Wada Eye Clinic, Chiba, 3Ishida Eye Clinic, Shizuoka, Japan Aim: Validating the hypothesis that accommodative microfluctuations (AMFs may be associated with severe symptoms in short tear break-up time (BUT dry eye (DE. Methods: This study included 12 subjects with short BUT DE (age: 49.6±18.3 years. Diagnoses were performed based on the presence of DE symptoms, BUT ≤5 s, Schirmer score >5 mm, and negative keratoconjunctival epithelial damage. Tear evaluation, AMF, and functional visual acuity (VA examinations were conducted before and after DE treatment. The AMF parameters evaluated were: total high-frequency component (HFC, HFC with low accommodation for the task of staring into the distance (HFC1, HFC with high accommodation for deskwork (HFC2. A subjective questionnaire of DE symptoms was also performed. Results: Mean BUT increased from 1.9±2.0 to 6.4±2.5 s after treatment (P<0.05. The mean logarithm of the minimum angle of resolution functional VA significantly improved (from 0.19±0.19 to 0.12±0.17; P<0.05. Mean power spectrum values for total HFC and HFC1 decreased (from 61.3±5.7 to 53.8±6.6 dB and from 62.9±10.5 to 52.4±6.2 dB, respectively; P<0.05, while the mean HFC2 power spectrum values did not differ before and after treatment (P>0.05. Subjective DE symptoms were reduced in nine patients. Conclusion: Along with the improvement of BUT after treatment, DE symptoms diminished and HFC1 and functional VA improved, suggesting that tear film instability is associated with deterioration of functional VA, AMF, and DE symptoms. Keywords: accommodative microfluctuation, ciliary muscle spasm, dry eye, ocular fatigue, tear break-up time, functional visual acuity 

  10. FY 2000 Report on the results of survey on recent situations of global warming mitigation measures related to alternative fluorochlorohydrocarbons; 2000 nendo daitai furon no chikyu ondanka taisaku doko ni kansuru chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    The recent situations of global warming mitigation measures related to flurine-containing greenhouse gases of HFC, PFC and SF{sub 6} are surveyed. In the meeting of the Parties of Montreal Protocol of 2000, no decision has been made on HCFC phaseout schedule amendment in the developed and developing countries, which is one of the major items. COP-6 has failed to reach agreement on handling CO2 absorption sources. For the international trends in estimation of the emissions of HFC and others, the IPCC's emission estimation methodology guidance for HFC, PFC and SF{sub 6} (translated into Japanese) and the methodologies taken by other countries are introduced. The trends of the emission control measures for HFC, PFC and SF{sub 6} include CO2 refrigerant application for mobile air-conditioners, announcement by Coca-Cola of HFC phaseout by 2004, announcement by the Canadian refrigerant air-conditioner industry of introduction of the surcharge system for promoting refrigerant recovery, and SF{sub 6} emission reduction technologies in Mg fabricating industries. Also introduced are cost evaluation of emission reduction technologies, latest scientific knowledge in the global environments, and harmonization of global warming mitigation and ozone layer protection in the developing countries, among others. (NEDO)

  11. Recycling of tailings from Korea Molybdenum Corporation as admixture for high-fluidity concrete.

    Science.gov (United States)

    Jung, Moon Young; Choi, Yun Wang; Jeong, Jae Gwon

    2011-01-01

    The main objective of this study is to develop an eco-friendly and a large recycling technique of flotation Tailings from korea (TK) from metal mines as construction materials such as admixtures for high-fluidity concrete (HFC). TK used in this study was obtained from the Korea Molybdenum Corporation in operation. TK was used as the alternative material to adjust flowability and viscosity of HFC in the form of powder agent which enables adjustment of concrete compressive strength. In this study, we have performed concrete rheological tests and concrete flowability tests to obtain the quality characteristics of TK for using as the admixture in producing HFC. The results indicated that the adequate mix ratio of cement to TK should be 8:2 (vol%). It is more effective to use the TK as admixture to control flowability, viscosity and strength of HFC than the normal concrete. It was found that TK could be recycled construction materials in bulk such as admixture for HFC, in terms of the economic and eco-friendly aspects.

  12. Frequencies of inaudible high-frequency sounds differentially affect brain activity: positive and negative hypersonic effects.

    Directory of Open Access Journals (Sweden)

    Ariko Fukushima

    Full Text Available The hypersonic effect is a phenomenon in which sounds containing significant quantities of non-stationary high-frequency components (HFCs above the human audible range (max. 20 kHz activate the midbrain and diencephalon and evoke various physiological, psychological and behavioral responses. Yet important issues remain unverified, especially the relationship existing between the frequency of HFCs and the emergence of the hypersonic effect. In this study, to investigate the relationship between the hypersonic effect and HFC frequencies, we divided an HFC (above 16 kHz of recorded gamelan music into 12 band components and applied them to subjects along with an audible component (below 16 kHz to observe changes in the alpha2 frequency component (10-13 Hz of spontaneous EEGs measured from centro-parieto-occipital regions (Alpha-2 EEG, which we previously reported as an index of the hypersonic effect. Our results showed reciprocal directional changes in Alpha-2 EEGs depending on the frequency of the HFCs presented with audible low-frequency component (LFC. When an HFC above approximately 32 kHz was applied, Alpha-2 EEG increased significantly compared to when only audible sound was applied (positive hypersonic effect, while, when an HFC below approximately 32 kHz was applied, the Alpha-2 EEG decreased (negative hypersonic effect. These findings suggest that the emergence of the hypersonic effect depends on the frequencies of inaudible HFC.

  13. Frequencies of inaudible high-frequency sounds differentially affect brain activity: positive and negative hypersonic effects.

    Science.gov (United States)

    Fukushima, Ariko; Yagi, Reiko; Kawai, Norie; Honda, Manabu; Nishina, Emi; Oohashi, Tsutomu

    2014-01-01

    The hypersonic effect is a phenomenon in which sounds containing significant quantities of non-stationary high-frequency components (HFCs) above the human audible range (max. 20 kHz) activate the midbrain and diencephalon and evoke various physiological, psychological and behavioral responses. Yet important issues remain unverified, especially the relationship existing between the frequency of HFCs and the emergence of the hypersonic effect. In this study, to investigate the relationship between the hypersonic effect and HFC frequencies, we divided an HFC (above 16 kHz) of recorded gamelan music into 12 band components and applied them to subjects along with an audible component (below 16 kHz) to observe changes in the alpha2 frequency component (10-13 Hz) of spontaneous EEGs measured from centro-parieto-occipital regions (Alpha-2 EEG), which we previously reported as an index of the hypersonic effect. Our results showed reciprocal directional changes in Alpha-2 EEGs depending on the frequency of the HFCs presented with audible low-frequency component (LFC). When an HFC above approximately 32 kHz was applied, Alpha-2 EEG increased significantly compared to when only audible sound was applied (positive hypersonic effect), while, when an HFC below approximately 32 kHz was applied, the Alpha-2 EEG decreased (negative hypersonic effect). These findings suggest that the emergence of the hypersonic effect depends on the frequencies of inaudible HFC.

  14. Cyber Security in Digital I and C Implementation

    Energy Technology Data Exchange (ETDEWEB)

    Chow, Ivan; Hsu, Allen; Kim, Jong Min; Luo, William [Doosan HF Controls, Texas (United States)

    2011-08-15

    During the Nuclear Regulatory Commission (NRC) audit process of Doosan HF Control HFC-6000 safety system 2009, cyber security assessment was a major audit process. The result of the assessment was favorably satisfied. As preventing digital I and C systems from being hijacked by malicious software a major goal for the NRC, audit process of actual digital I and C implementations such as the HFC-6000 safety system which provides already strong cyber security measures is mutually beneficial to both the NRC and the vendor: NRC can enhance their set of cyber security assessments and vendors such as Doosan HFC can also augment their cyber security measures. The NRC Safety Evaluation Report (SER) for the HFC-6000 system was released in April 2011 qualifying the system to be used as safety systems in US nuclear power plants. This paper provides the summary of the cyber security assessment of the complete software life cycle of HFC-6000 Safety System. Lessons learned in each life cycle phase are provided. In addition, alternate measures or recommendations for enhancing the cyber security in each life cycle phase are also described.

  15. Cyber Security in Digital I and C Implementation

    International Nuclear Information System (INIS)

    Chow, Ivan; Hsu, Allen; Kim, Jong Min; Luo, William

    2011-01-01

    During the Nuclear Regulatory Commission (NRC) audit process of Doosan HF Control HFC-6000 safety system 2009, cyber security assessment was a major audit process. The result of the assessment was favorably satisfied. As preventing digital I and C systems from being hijacked by malicious software a major goal for the NRC, audit process of actual digital I and C implementations such as the HFC-6000 safety system which provides already strong cyber security measures is mutually beneficial to both the NRC and the vendor: NRC can enhance their set of cyber security assessments and vendors such as Doosan HFC can also augment their cyber security measures. The NRC Safety Evaluation Report (SER) for the HFC-6000 system was released in April 2011 qualifying the system to be used as safety systems in US nuclear power plants. This paper provides the summary of the cyber security assessment of the complete software life cycle of HFC-6000 Safety System. Lessons learned in each life cycle phase are provided. In addition, alternate measures or recommendations for enhancing the cyber security in each life cycle phase are also described

  16. A study of creep behavior in refractory alloys for thermionic emitter applications

    International Nuclear Information System (INIS)

    Gao Hong; Zee, Ralph

    1997-01-01

    The creep behavior of HfC strengthened tungsten alloys was studied. An ultrahigh vacuum high precision creep test system was constructed for this purpose so that the samples could be heated up to 3000 K for heat treatment and creep strain could be measured from the creep sample inside the vacuum chamber. Creep tests were conducted in tungsten strengthened with 0.37 percent of HfC at temperatures between 2000 K to 2500 K for durations up to 8 weeks. To explain the creep behavior observed in this dispersion strengthened alloy, a creep model was proposed which accounted for the presence of HfC particles in the form of a back stress generated by these particles. This model was verified by the creep test data of a W-0.37HfC alloy tested under both extruded and recrystallized microstructural conditions. According to this model, the steady state creep of this type alloys was expected to increase with time due to the HfC particle coarsening and recrystallization under high temperatures. In contrast, conventional simple power law creep only predicts a constant steady state creep for these materials, which does not represent the microstructural evolution of the materials. In this study, the experimental study was designed to verify the semi-mechanistic phenomenological creep model developed for carbide particle strengthened tungsten alloys

  17. Cochlear Synaptopathy and Noise-Induced Hidden Hearing Loss

    Directory of Open Access Journals (Sweden)

    Lijuan Shi

    2016-01-01

    Full Text Available Recent studies on animal models have shown that noise exposure that does not lead to permanent threshold shift (PTS can cause considerable damage around the synapses between inner hair cells (IHCs and type-I afferent auditory nerve fibers (ANFs. Disruption of these synapses not only disables the innervated ANFs but also results in the slow degeneration of spiral ganglion neurons if the synapses are not reestablished. Such a loss of ANFs should result in signal coding deficits, which are exacerbated by the bias of the damage toward synapses connecting low-spontaneous-rate (SR ANFs, which are known to be vital for signal coding in noisy background. As there is no PTS, these functional deficits cannot be detected using routine audiological evaluations and may be unknown to subjects who have them. Such functional deficits in hearing without changes in sensitivity are generally called “noise-induced hidden hearing loss (NIHHL.” Here, we provide a brief review to address several critical issues related to NIHHL: (1 the mechanism of noise induced synaptic damage, (2 reversibility of the synaptic damage, (3 the functional deficits as the nature of NIHHL in animal studies, (4 evidence of NIHHL in human subjects, and (5 peripheral and central contribution of NIHHL.

  18. Germination as a processing technique for soybeans in small-scale ...

    African Journals Online (AJOL)

    charlesk

    2013-06-15

    Jun 15, 2013 ... Germination and other traditional methods, namely soaking and dehulling, were evaluated as alternative processing methods for soybeans. The effect of the processing treatment on the level of different. ANFs, nutritional composition and in vitro protein digestibility (IVPD) of soybean seeds was determined.

  19. Effects of a concentrate of pea antinutritional factors on pea protein digestibility in piglets

    NARCIS (Netherlands)

    Guen, M.P. Le; Huisman, J.; Guéguen, J.; Beelen, G.; Verstegen, M.W.A.

    1995-01-01

    Four experiments were designed to investigate the apparent ileal digestibility of raw pea (Pisum sativum) and two of its components - an isolate of its proteins and a concentrate of its proteinaceous antinutritional factors (ANFs). Three varieties of peas were used: spring varieties Finale and

  20. Phytochemical Screening and Proximate Analysis of Newbouldia ...

    African Journals Online (AJOL)

    The study was conducted to assess the phytochemical and proximate composition of Newboudia laevis leaves and Allium sativum bulb extracts. The leaves and bulbs extracts were analyzed for their chemical composition and antinutritional factors (ANFs) which include moisture, crude protein, crude fat, crude fiber, total ash ...

  1. Inhibition of phage infection in capsule-producing Streptococcus ...

    African Journals Online (AJOL)

    SERVER

    2007-10-04

    Oct 4, 2007 ... prove the physical properties of low fat yogurt and some reduced fat cheeses .... tion of the procedure described by Terzaghi and Sandine (1975). Sugars were ... polysaccharides share structural saccharide constituents. (glucose ..... 11, the interface between the baseplate anf short tail fibers. J. Mol. Biol.

  2. Symptoms as the main problem

    DEFF Research Database (Denmark)

    Rosendal, Marianne; Carlsen, Anders Helles; Rask, Mette Troellund

    2016-01-01

    Dette studie undersøger tilfredsheden hos patienter, der blev afsluttet i almen praksis uden specifik diagnose, dvs. hvor lægen efter afsluttet konsultation kun kunne anføre "symptom" eller "problem" som slutdiagnose. Det drejer sig om ca. 1/3 af alle helbredsrelaterede konsultationer i almen...

  3. Modelling of heat treatment of soy

    NARCIS (Netherlands)

    Hout, van den R.

    1997-01-01


    Soybeans are used as raw material for human nutrition and animal feed because of their high nutritional value. Consumption of raw beans has negative effects on the growth and health of human beings and animals. These effects are caused by antinutritional. factors (ANFs). Trypsin

  4. Segmentation of culturally diverse visitors' values in forest recreation management

    Science.gov (United States)

    C. Li; H.C. Zinn; G.E. Chick; J.D. Absher; A.R. Graefe; Y. Hsu

    2007-01-01

    The purpose of this study was to examine the potential utility of HOFSTEDE’s measure of cultural values (1980) for group segmentation in an ethnically diverse population in a forest recreation context, and to validate the values segmentation, if any, via socio-demographic and service quality related variables. In 2002, the visitors to the Angeles National Forest (ANF)...

  5. Med Wacquant i det ghettopolitiske felt

    DEFF Research Database (Denmark)

    Schultz Larsen, Troels

    2011-01-01

    og de danske forsømte boligområder indtager samme position i det (bolig)sociale hierarki og dermed kan betegnes som homologe, er de historisk, socialt, politisk og strukturelt betinget af væsentligt forskellige årsager. Som erstatning for ”ghetto”-begrebet anføres i stedet begrebet ”de forsømte...

  6. Coding deficits in noise-induced hidden hearing loss may stem from incomplete repair of ribbon synapses in the cochlea

    Directory of Open Access Journals (Sweden)

    Lijuan eShi

    2016-05-01

    Full Text Available Recent evidence has shown that noise-induced damage to the synapse between inner hair cells (IHCs and type I afferent auditory nerve fibers (ANFs may occur in the absence of permanent threshold shift (PTS, and that synapses connecting IHCs with low spontaneous rate (SR ANFs are disproportionately affected. Due to the functional importance of low-SR ANF units for temporal processing and signal coding in noisy backgrounds, deficits in cochlear coding associated with noise-induced damage may result in significant difficulties with temporal processing and hearing in noise (i.e., hidden hearing loss. However, significant noise-induced coding deficits have not been reported at the single unit level following the loss of low-SR units. We have found evidence to suggest that some aspects of neural coding are not significantly changed with the initial loss of low-SR ANFs, and that further coding deficits arise in association with the subsequent reestablishment of the synapses. This suggests that synaptopathy in hidden hearing loss may be the result of insufficient repair of disrupted synapses, and not simply due to the loss of low-SR units. These coding deficits include decreases in driven spike rate for intensity coding as well as several aspects of temporal coding: spike latency, peak-to-sustained spike ratio and the recovery of spike rate as a function of click-interval.

  7. Leide Heinrich Gösekeni sõnavaramust / Valve-Liivi Kingisepp

    Index Scriptorium Estoniae

    Kingisepp, Valve-Liivi, 1935-

    2009-01-01

    Analüüsitakse Heinrich Gösekeni käsiraamatu "Manuductio ad Linguam Oesthonicam, Anführung zur Öhstnischen Sprache" (1660) saksa-eesti sõnastikku, võrreldes sealseid leide teiste eesti varasemate ja hilisemate sõnastikega

  8. Magnetic resonance imaging of avascular necrosis of the femoral head

    Energy Technology Data Exchange (ETDEWEB)

    Ozono, Kenji; Takaoka, Kunio [Osaka Univ. (Japan). Faculty of Medicine

    1989-07-01

    To evaluate the diagnostic value and limitation of magnetic resonance imaging (MRI) in avascular necrosis of the femoral head (ANF), clinical stages and types were examined on MRI scans of 68 femoral heads of 46 ANF patients. Stage 1 patients fell into two groups: (1) stage 1-A group of real ANF in which abnormal findings were observed on both MRI and bone scanning and (2) stage 1-B group of asymptomatic ANF in which MRI detected abnormality that was missed by bone scanning. In these groups, MRI showed inhomogeneous, band, and spotty patterns. Stage 2 or 3 patients tended to have homogeneous or ring-pattern hypointensities on MRI. Histological examination showed that repair reaction at the marginal site of hypointensity was partly responsible for the occurrence of hypointensities. In Stage 4 patients, not only femoral head but also acetabular site was visible as homogeneous hypointensity, which was similar to that in osteoarthritis. Because repair areas, as well as necrotic areas, were frequently visualized as hypointensities in Stages 2 or more, MRI might overestimate necrotic areas. (N.K.).

  9. The Constraints on Strategy of an Organizational Structure

    DEFF Research Database (Denmark)

    Eriksen, Bo

    2007-01-01

     Artiklen diskuterer relationen mellem organisationens struktur og dens evne til at formulere og realisere sine strategier. Hovedargumentet er skelner mellem exploration og exploitation strategier og det anføres at der er en indbygget konflikt mellem disse. Fleksible (ambidextrous) organisationer...

  10. US (United States) Army Aeromedical Research Laboratory Annual Progress Report, FY 1982.

    Science.gov (United States)

    1982-10-01

    lr- mechan i SMS found i n caIda ver tcS t s Progress Fe work wa s compleoted and a repo rt i ssued. Ito data s:! lowoP! cod simil anf toy bet te en...filter contaminants known to exist in the operational environment. Physiological data, heart rate, oxygen tension and respiratory functions as well as

  11. Self-propagating high temperature synthesis as a method of determination of formation heat of refractory compounds

    International Nuclear Information System (INIS)

    Maslov, V.M.; Neganov, A.S.; Borovinskaya, I.P.; Merzhanov, A.G.

    1978-01-01

    Determination possibility of formation heats of refractory compounds in the process of direct synthesis from elements in a special calorimeter in the combustion regime is studied. Determined are formation heats of carbides - ZrCsub(0.92), Hf Csub(0.93), TaCsub(0.86), borides - ZrB 2 , HfB 2 NbB, NbB 2 , TaB, TaB 2 , MoB and silicides - ZrSi, ZrSi 2 , MoSi 2 . The results of chemical and x-ray phase analyses of the synthesized compounds are also given. Total error of formation heat determination methods does not surpass 2.0%

  12. National technical report (Matsushita Electric Industrial Company), Vol. 41, No. 3, June 1995. Special issue on environmental technologies

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    ;Contents: Preface to Special Issue on Environmental Technologies; Total System for Recycling and Optimal Treatment of Waste Home Electric Appliances; Material Reduction Design Using Computer Aided Engineering; Rewritable Thermal Recording Sheet; Reusable Taping System; Estimating Method for Disassembly of Home Appliances; Thermal Design Technique to Reduce Furnace Running Cost to Half; Study of Air Conditioner Using HFC Refrigerant Blend; High-Efficiency Compact Rotary Compressor Using New Refrigerant HFC 134a for Automotive Air Conditioner; Simulation for Refrigerators Using HFC 134a; Zero-ODP (Ozone Depletion Potential) Rigid Insulation Foams for Refrigerators; Heat Energy of Industrial Waste Combustion Gas Utilization System; Exhaust Gas Denitrification System for Car Road Tunnels and Underground Parking Areas; Apparatus for Regenerating Diesel Particulate Filter Using Microwave; Analysis of Advanced Treatment System of Heavy Metals in Waste Water; Ventilating and Air-Conditioning System for Energy-Saving Houses; Garbage Disposer; and Anti-Microbial Resin and Applications to Products in Harmony with Living Environment.

  13. Comparison of a R744 cascade refrigeration system with R404A and R22 conventional systems for supermarkets

    International Nuclear Information System (INIS)

    Silva, Alessandro da; Pedone Bandarra Filho, Enio; Pontes Antunes, Arthur Heleno

    2012-01-01

    The present article focuses on the energy efficiency and climate performance of three different systems used in supermarket applications. The refrigeration systems consist of a cascade cycle (CO 2 /HFC-404A) – provide nominal refrigerating capacity – with carbon dioxide for subcritical operation and HFC-404A in the high stage temperature stage (pump circuit for normal refrigeration and direct expansion for deep-freezing), and also HFC-404A and HCFC-22 with direct expansion systems. The cascade system presented a lower refrigerant charge, 47 kg of both fluids, which represents less than a half of the refrigerant charge of the other systems. An important factor is the total GWP in case of leakage, where the impact in the atmosphere of the cascade system operating with CO 2 was much less than the two direct expansion systems.

  14. Measurement of some biophysical parameters in skin lesions of leprosy

    Directory of Open Access Journals (Sweden)

    A B Gupta

    1990-01-01

    Full Text Available Transepidermal water loss (TEWL, high frequency electrical conductance (HFC and the hydration state index (HSI were measured in sldn lesions of 30 paucibacillary leprosy patients and compared with the contralateral uninvolved skin. While the TEWL, HFC and HSI all showed lower values in the lesion site, as compared to the contralateral skin sites, the differences between the two sets of values significant in HFC and. HSI only at 2% and 1% level respectively. A significant positive correlation (r = 0.69 was found to eidst between these two parameters. The parameters correlate well with the known reduced sweating in skin lesions of TT and BT leprosy and may therefore be considered as good objective parameters to confirm hypohydrosis in suspected skin lesions ofleprosy.

  15. A density functional study of EPR hyperfine coupling of vanadocene(IV) complexes

    International Nuclear Information System (INIS)

    Honzicek, Jan; Vinklarek, Jaromir; Nachtigall, Petr

    2004-01-01

    Suitability of various exchange-correlation functionals for calculations of HFC tensors was investigated. It was found that A iso calculated with B3PW91 functional correlates fairly well with experimental A iso for broad range of vanadocene compounds. Simple scaling of calculated A iso was proposed. A good correspondence between experimental HFC tensors and those calculated at DFT optimised geometries was found. It is shown that structure of vanadocene complex can be assigned based on the comparison of experimental and theoretical HFC tensors and several examples are presented. The exchange functionals with large mixing of exact exchange (BHPB86) give A iso with an error that depends on the extent of spin-contamination of the wavefunction

  16. Hiperlipidemia familiar combinada: documento de consenso

    Directory of Open Access Journals (Sweden)

    Pedro Mata

    2014-10-01

    Es frecuente la asociación con diabetes mellitus tipo 2, hipertensión arterial y obesidad central. Los pacientes con HFC se consideran de riesgo cardiovascular alto y el objetivo terapéutico es un colesterol-LDL < 100 mg/dl, y < 70 mg/dl en presencia de enfermedad cardiovascular establecida o diabetes mellitus. Los pacientes con HFC requieren tratamiento con estatinas potentes y, a veces, tratamiento combinado. La identificación y el manejo de otros factores de riesgo cardiovascular, como la diabetes y la hipertensión, son fundamentales para reducir la carga de enfermedad cardiovascular. Este documento proporciona recomendaciones para el diagnóstico y el tratamiento integral de los pacientes con HFC especialmente dirigidas a médicos de atención primaria.

  17. Aramid Nanofiber Composites for Energy Storage Applications

    Science.gov (United States)

    Tung, Siu on

    Lithium ion batteries and non-aqueous redox flow batteries represent two of the most important energy storage technologies to efficient electric vehicles and power grid, which are essential to decreasing U.S. dependence on fossil fuels and sustainable economic growth. Many of the developmental roadblocks for these batteries are related to the separator, an electrically insulating layer between the cathode and anode. Lithium dendrite growth has limited the performance and threatened the safety of lithium ion batteries by piercing the separator and causing internal shorts. In non-aqueous redox flow batteries, active material crossover through microporous separators and the general lack of a suitable ion conducting membrane has led to low operating efficiencies and rapid capacity fade. Developing new separators for these batteries involve the combination of different and sometimes seemingly contradictory properties, such as high ionic conductivity, mechanical stability, thermal stability, chemical stability, and selective permeability. In this dissertation, I present work on composites made from Kevlar-drived aramid nanofibers (ANF) through rational design and fabrication techniques. For lithium ion batteries, a dendrite suppressing layer-by-layer composite of ANF and polyethylene oxide is present with goals of high ionic conductivity, improved safety and thermal stability. For non-aqueous redox flow batteries, a nanoporous ANF separator with surface polyelectrolyte modification is used to achieve high coulombic efficiencies and cycle life in practical flow cells. Finally, manufacturability of ANF based separators is addressed through a prototype machine for continuous ANF separator production and a novel separator coated on anode assembly. In combination, these studies serve as a foundation for addressing the challenges in separator engineering for lithium ion batteries and redox flow batteries.

  18. TaxHf1−xB2–SiC multiphase oxidation protective coating for SiC-coated carbon/carbon composites

    International Nuclear Information System (INIS)

    Ren, Xuanru; Li, Hejun; Fu, Qiangang; Li, Kezhi

    2014-01-01

    Highlights: • Ta x Hf 1−x B 2 –SiC coating was prepared on SiC coated C/C by in-situ reaction method. • TaB 2 and HfB 2 were introduced in the form of solid solution Ta x Hf 1−x B 2 . • The coating could protect C/C for 1480 h with only 0.57% mass loss at 1773 K in air. • Oxidation layer consists of out Ta–Si–O compound layer and inner SiO 2 glass layer. • Ta–Si–O compound silicate layer presents a better stability than SiO 2 glass layer. - Abstract: A Ta x Hf 1−x B 2 –SiC coating was prepared by in-situ reaction method on SiC coated C/C composites. Ta x Hf 1−x B 2 phase is the form of solid solution between TaB 2 and HfB 2 . Isothermal oxidation behavior at 1773 K and ablation behavior of the coated C/C were tested. Ta x Hf 1−x B 2 –SiC/SiC coating could protect the C/C from oxidation at 1773 K for 1480 h and ablation above 2200 K for 40 s. During oxidation, oxides of Ta and Hf atoms exist as “pinning phases” in the compound glass layer consisted of outer Ta–Si–O compound silicate layer and inner SiO 2 glass layer, which was responsible for the excellent oxidation resistance

  19. Inflammatory Signals shift from adipose to liver during high fat feeding and influence the development of steatohepatitis in mice

    Directory of Open Access Journals (Sweden)

    Greenfeder Scott

    2011-03-01

    Full Text Available Abstract Background Obesity and inflammation are highly integrated processes in the pathogenesis of insulin resistance, diabetes, dyslipidemia, and non-alcoholic fatty liver disease. Molecular mechanisms underlying inflammatory events during high fat diet-induced obesity are poorly defined in mouse models of obesity. This work investigated gene activation signals integral to the temporal development of obesity. Methods Gene expression analysis in multiple organs from obese mice was done with Taqman Low Density Array (TLDA using a panel of 92 genes representing cell markers, cytokines, chemokines, metabolic, and activation genes. Mice were monitored for systemic changes characteristic of the disease, including hyperinsulinemia, body weight, and liver enzymes. Liver steatosis and fibrosis as well as cellular infiltrates in liver and adipose tissues were analyzed by histology and immunohistochemistry. Results Obese C57BL/6 mice were fed with high fat and cholesterol diet (HFC for 6, 16 and 26 weeks. Here we report that the mRNA levels of macrophage and inflammation associated genes were strongly upregulated at different time points in adipose tissues (6-16 weeks and liver (16-26 weeks, after the start of HFC feeding. CD11b+ and CD11c+ macrophages highly infiltrated HFC liver at 16 and 26 weeks. We found clear evidence that signals for IL-1β, IL1RN, TNF-α and TGFβ-1 are present in both adipose and liver tissues and that these are linked to the development of inflammation and insulin resistance in the HFC-fed mice. Conclusions Macrophage infiltration accompanied by severe inflammation and metabolic changes occurred in both adipose and liver tissues with a temporal shift in these signals depending upon the duration of HFC feeding. The evidences of gene expression profile, elevated serum alanine aminotransferase, and histological data support a progression towards nonalcoholic fatty liver disease and steatohepatitis in these HFC-fed mice within the

  20. Dynamics of soil organic carbon in density fractions during post-agricultural succession over two lithology types, southwest China.

    Science.gov (United States)

    Wen, Li; Li, Dejun; Chen, Hao; Wang, Kelin

    2017-10-01

    Agricultural abandonment has been proposed as an effective way to enhance soil organic carbon (SOC) sequestration. Nevertheless, SOC sequestration in the long term is largely determined by whether the stable SOC fractions will increase. Here the dynamics of SOC fractions during post-agricultural succession were investigated in a karst region, southwest China using a space-for-time substitution approach. Cropland, grassland, shrubland and secondary forest were selected from areas underlain by dolomite and limestone, respectively. Density fractionation was used to separate bulk SOC into free light fraction (FLFC) and heavy fraction (HFC). FLFC contents were similar over dolomite and limestone, but bulk SOC and HFC contents were greater over limestone than over dolomite. FLFC content in the forest was greater than in the other vegetation types, but bulk SOC and HFC contents increased from the cropland through to the forest for areas underlain by dolomite. The contents of bulk SOC and its fractions were similar among the four vegetation types over limestone. The proportion of FLFC in bulk SOC was higher over dolomite than over limestone, but the case was inverse for the proportion of HFC, indicating SOC over limestone was more stable. However, the proportions of both FLFC and HFC were similar among the four vegetation types, implying that SOC stability was not changed by cropland conversion. Exchangeable calcium explained most of the variance of HFC content. Our study suggests that lithology not only affects SOC content and its stability, but modulates the dynamics of SOC fractions during post-agricultural succession. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Non azeotrope mixing refrigerating fluids condensation outside of an horizontal tubes stack; Condensation de melanges non azeotropes de fluides frigorigenes a l'exterieur d'un faisceau de tubes horizontaux

    Energy Technology Data Exchange (ETDEWEB)

    Signe, J.Ch.

    1999-04-16

    The development of non-azeotrope mixing, as regular refrigerating fluids substitute, calls in question the experience for the design of refrigerating and cooling machinery. Studies to better understand these fluids behaviour are necessary. The aim of this thesis is the knowledge enlargement on the pure fluids and non azeotrope mixing condensation, outside of a tubes stack, and to simulate the heat transfers. The tubes stack is a condenser, type TEMA X often used in refrigerating machinery. The binary mixing HFC 134a-HFC23, allows a large sliding scale. (A.L.B.)

  2. New use of ammonia in heat pumps; Nouvelle utilisation de l`ammoniac en pompe a chaleur

    Energy Technology Data Exchange (ETDEWEB)

    Hivet, B.; Ducruet, C. [Electricite de France, 77 - Moret sur Loing (France). Direction des Etudes et Recherches

    1996-12-31

    According to simple thermodynamic criteria and to pollution regulations, ammonia and HFC 134a are the only refrigerating fluids that can be used in heat pumps. Ammonia is particularly performing at high condensation temperatures. However, its use has become possible thanks to the use of industrial refrigerating compressors with a maximum operation pressure of 40 bars. Test results confirm the interesting thermal performances of this fluid. A comparison with the HFC 134a refrigerant indicates that ammonia leads to equal or better coefficients of performance for higher volume powers. Two applications taken in the agriculture and food industries are presented. (J.S.)

  3. Hiperlipidemia familiar combinada: documento de consenso

    OpenAIRE

    Pedro Mata; Rodrigo Alonso; Antonio Ruíz-Garcia; Jose L. Díaz-Díaz; Noemí González; Teresa Gijón-Conde; Ceferino Martínez-Faedo; Ignacio Morón; Ezequiel Arranz; Rocío Aguado; Rosa Argueso; Leopoldo Perez de Isla

    2014-01-01

    La hiperlipidemia familiar combinada (HFC) es un trastorno muy frecuente asociado a enfermedad coronaria prematura. Se transmite de forma autosómica dominante, aunque no existe un gen único asociado al trastorno. El diagnóstico se realiza mediante criterios clínicos, y son importantes la variabilidad del fenotipo lipídico y la historia familiar de hiperlipidemia. Es frecuente la asociación con diabetes mellitus tipo 2, hipertensión arterial y obesidad central. Los pacientes con HFC se cons...

  4. Research and Development Opportunities for Joining Technologies in HVAC&R

    Energy Technology Data Exchange (ETDEWEB)

    Goetzler, William [Navigant Consulting, Burlington, MA (United States); Guernsey, Matt [Navigant Consulting, Burlington, MA (United States); Young, Jim [Navigant Consulting, Burlington, MA (United States)

    2015-10-01

    The Building Technologies Office (BTO) works with researchers and industry partners to develop and deploy technologies that can substantially reduce energy consumption and greenhouse gas (GHG) emissions in residential and commercial buildings. This opportunity assessment aims to advance BTO’s energy savings, GHG reduction, and other program goals by identifying research and development (R&D) initiatives for joining technologies in heating, ventilation, air-conditioning, and refrigeration (HVAC&R) systems. Improving joining technologies for HVAC&R equipment has the potential to increase lifetime equipment operating efficiency, decrease equipment and project cost, and most importantly reduce hydroflourocarbon (HFC) refrigerant leakage to support HFC phasedown and GHG reduction goals.

  5. Hydrochlorofluorocarbon and hydrofluorocarbon emissions in East Asia determined by inverse modeling

    Directory of Open Access Journals (Sweden)

    A. Stohl

    2010-04-01

    Full Text Available The emissions of three hydrochlorofluorocarbons, HCFC-22 (CHClF2, HCFC-141b (CH3CCl2F and HCFC-142b (CH3CClF2 and three hydrofluorocarbons, HFC-23 (CHF3, HFC-134a (CH2FCF3 and HFC-152a (CH3CHF2 from four East Asian countries and the Taiwan region for the year 2008 are determined by inverse modeling. The inverse modeling is based on in-situ measurements of these halocarbons at the Japanese stations Cape Ochi-ishi and Hateruma, the Chinese station Shangdianzi and the South Korean station Gosan. For every station and every 3 h, 20-day backward calculations were made with the Lagrangian particle dispersion model FLEXPART. The model output, the measurement data, bottom-up emission information and corresponding uncertainties were fed into an inversion algorithm to determine the regional emission fluxes. The model captures the observed variation of halocarbon mixing ratios very well for the two Japanese stations but has difficulties explaining the large observed variability at Shangdianzi, which is partly caused by small-scale transport from Beijing that is not adequately captured by the model. Based on HFC-23 measurements, the inversion algorithm could successfully identify the locations of factories known to produce HCFC-22 and emit HFC-23 as an unintentional byproduct. This lends substantial credibility to the inversion method. We report national emissions for China, North Korea, South Korea and Japan, as well as emissions for the Taiwan region. Halocarbon emissions in China are much larger than the emissions in the other countries together and contribute a substantial fraction to the global emissions. Our estimates of Chinese emissions for the year 2008 are 65.3±6.6 kt/yr for HCFC-22 (17% of global emissions extrapolated from Montzka et al., 2009, 12.1±1.6 kt/yr for HCFC-141b (22%, 7.3±0.7 kt/yr for HCFC-142b (17%, 6.2±0.7 kt/yr for HFC

  6. 40 CFR Appendix A to Subpart G of... - Substitutes Subject to Use Restrictions and Unacceptable Substitutes

    Science.gov (United States)

    2010-07-01

    ... safely in this end-use. CFC-12, motor vehicle air conditioners (retrofit) HCFC-22/HFC-142b/CFC-12... to demonstrate it can be used safely in this end-use. CFC-12, motor vehicle air conditioners (new... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE...

  7. Lifetime prediction of EC, DPA, akardite II and MNA stabilized triple base propellants, comparison of heat generation rate and stabilizer consumption

    NARCIS (Netherlands)

    Boers, M.N.; Klerk, W.P.C. de

    2005-01-01

    A lifetime prediction study is carried out on four triple base propellant compositions by artificial ageing. The ageing effects are studied with High Performance Liquid Chromatography (HPLC) and Heat Flow Calorimetry (HFC) in order to find the most effective stabilizer and to evaluate the advantages

  8. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    An integrated assessment of emissions of some important refrigerant ozone depleting substances (ODSs) (CFC-11, CFC-12, HCFC-141b and HFC-134a) and their contributed ozone depletion potentials (ODPs) and global warming potentials (GWPs) have been made in the megacity Lahore (Pakistan) for the periodfrom ...

  9. Evaluation of cermet materials suitable for lithium lubricated thrust bearings for high temperature operation

    Science.gov (United States)

    Sinclair, J. H.; Hendrixson, W. H.

    1974-01-01

    Cerment materials (HfC - 10 wt% W; HfC - 10 wt% TaC - 10 wt%W; HfC - 2 wt% CbC - 8 wt% Mo;Hfn - 10 wt% W; Hfn - 10 wt% TaN - 10 wt% W; and ZrC - 17 wt% W) were evaluated for possible use as lithium-lubricated bearings in the control system of a nuclear reactor. Tests of compatibility with lithium were made in T-111 (Ta-8W-2Hf) capsules at temperatures up to 1090 C. The tendencies of HfC-TaC-W, HfC-CbC-Mo, and HfN-W to bond to themselves and to the refractory alloys T-111 and TZM when enclosed in lithium-filled capsules under a pressure of 2000 psi at 980 and 1200 C for 1933 hours were evaluated. Thermal expansion characteristics were determined for the same three materials from room temperature to 1200 C. On the basis of these tests, HfC-10 TaC-10W and HfN-10W were selected as the best and second best candidates, respectively, of the materials tested for the bearing application.

  10. Effect of aerobic exercise and diet on liver fat in pre-diabetic patients with non-alcoholic-fatty-liver-disease : A randomized controlled trial

    NARCIS (Netherlands)

    Cheng, Sulin; Ge, Jun; Zhao, Can; Le, Shenglong; Yang, Yifan; Ke, Dandan; Wu, Na; Tan, Xiao; Zhang, Xiaobo; Du, Xiaming; Sun, Jianqin; Wang, Renwei; Shi, Yongyong; Borra, Ronald J. H.; Parkkola, Riitta; Wiklund, Petri; Lu, Dajiang

    2017-01-01

    The study aimed to assess whether aerobic exercise (AEx) training and a fibre-enriched diet can reduce hepatic fat content (HFC) and increase glycaemic control in pre-diabetic patients with non-alcoholic fatty liver disease (NAFLD). Six-hundred-and-three patients from seven clinics in Yangpu

  11. Effect of anti-gut inflammatory agent on insulin resistance and lipid ...

    African Journals Online (AJOL)

    Purpose: To further explore the effect of 5-aminosalicylic acid (5-ASA) treatment on lipid levels in mice fed different ... insulin and the curve of glucose tolerance test (GTT) in mice fed LFD, HFD or HFC diet were not affected by ... diabetes, the extent to which gut inflammation .... and homeostasis of glucose in diet-induced.

  12. Hafnium carbide nanocrystal chains for field emitters

    International Nuclear Information System (INIS)

    Tian, Song; Li, Hejun; Zhang, Yulei; Ren, Jincui; Qiang, Xinfa; Zhang, Shouyang

    2014-01-01

    A hafnium carbide (HfC) nanostructure, i.e., HfC nanocrystal chain, was synthesized by a chemical vapor deposition (CVD) method. X-ray diffractometer, field-emission scanning electron microscope, transmission electron microscope, and energy-dispersive X-ray spectrometer were employed to characterize the product. The synthesized one-dimensional (1D) nanostructures with many faceted octahedral nanocrystals possess diameters of tens of nanometers to 500 nm and lengths of a few microns. The chain-like structures possess a single crystalline structure and preferential growth direction along the [1 0 0] crystal orientation. The growth of the chains occurred through the vapor–liquid–solid process along with a negative-feedback mechanism. The field emission (FE) properties of the HfC nanocrystal chains as the cold cathode emitters were examined. The HfC nanocrystal chains display good FE properties with a low turn-on field of about 3.9 V μm −1 and a high field enhancement factor of 2157, implying potential applications in vacuum microelectronics.

  13. Lattice vibrational properties of transition metal carbides (TiC, ZrC

    Indian Academy of Sciences (India)

    Lattice vibrational properties of transition metal carbides (TiC, ZrC and HfC) have been presented by including the effects of free-carrier doping and three-body interactions in the rigid shell model. The short-range overlap repulsion is operative up to the second neighbour ions. An excellent agreement has been obtained ...

  14. 40 CFR Appendix F to Subpart B of... - Standard for Recover-Only Equipment That Extracts a Single, Specific Refrigerant Other Than CFC...

    Science.gov (United States)

    2010-07-01

    ... does not recycle, any single, specific automotive refrigerant other than CFC-12 or HFC-134a, including... or equivalent new product specifications before reuse in a mobile air-conditioning system.” The... capable of ensuring removal of refrigerant from the system being serviced by reducing the system pressure...

  15. Fire and explosion hazards of refractory compound powders

    International Nuclear Information System (INIS)

    Krivtsov, V.A.; Kostina, E.S.

    1978-01-01

    Data on fire and explosion hazards of refractory compound powders (HfC, ZrC,LaB 6 , ZrN, etc.) are presented. It is shown that refractory compounds can be fire- and exposion hazardous in various degrees. Qualitative and quantitative estimations of one of fire-hazard characteristics - smoldering temperature - are presented

  16. Upgrade of hybrid fibre coax networks towards bi-directional access

    NARCIS (Netherlands)

    Khoe, G.D.; Wolters, R.P.C.; Boom, van den H.P.A.; Prati, G.

    1997-01-01

    In this paper we describe an upgrade scenario for Hybrid Fibre Coax (HFC) CATV Networks towards hi-directional access. The communication system described has been newly designed, and is based on the use of Direct Sequence- Code Division Multiple-Access (DS-CDMA). Due to its spread-spectrum

  17. Lifetime prediction of EC, DPA, Akardite II and MNA stabilized triple base propellants, comparison of heat generation rate and stabilizer consumption

    Energy Technology Data Exchange (ETDEWEB)

    Boers, Marco N.; Klerk, Willem (Wim) P.C. de [TNO Defence, Security and Safety, P. O. Box 45, 2280 AA Rijswijk ZH (Netherlands)

    2005-10-01

    A lifetime prediction study is carried out on four triple base propellant compositions by artificial ageing. The ageing effects are studied with High Performance Liquid Chromatography (HPLC) and Heat Flow Calorimetry (HFC) in order to find the most effective stabilizer and to evaluate the advantages and disadvantages of both methods. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  18. CITEPA/ inventory UNFCCC December 2004

    International Nuclear Information System (INIS)

    2004-01-01

    This document provides statistical data on the greenhouse gases emissions PNLCCC in France. A first table presents the CO 2 emissions from 1990 to 2003. Others tables detail all the greenhouse gases (CH 4 , N 2 O, HFC, PFC and SF 6 ) emissions, per sector from 1990 to 2003. (A.L.B.)

  19. 75 FR 45130 - Draft Compliance Policy Guide Sec. 690.800 Salmonella

    Science.gov (United States)

    2010-08-02

    ... humans, such as pet food and pet treats, contaminated with Salmonella and also on regulatory policy... Compliance Policy (HFC-230), Office of Enforcement, Food and Drug Administration, 5600 Fishers Lane, Rockville, MD 20857. Send two self-addressed adhesive labels to assist that office in processing your...

  20. Evaluating the Impact of a Connecticut Program to Reduce Availability of Unhealthy Competitive Food in Schools

    Science.gov (United States)

    Long, Michael W.; Henderson, Kathryn E.; Schwartz, Marlene B.

    2010-01-01

    Background: This article seeks to inform state and local school food policies by evaluating the impact of Connecticut's Healthy Food Certification (HFC), a program which provides monetary incentives to school districts that choose to implement state nutrition standards for all foods sold to students outside reimbursable school meals. Methods: Food…

  1. Effect of anti-gut inflammatory agent on insulin resistance and lipid ...

    African Journals Online (AJOL)

    The level of fasting blood glucose, fasting plasma insulin and the curve of glucose tolerance test (GTT) in mice fed LFD, HFD or HFC diet were not affected by 5-ASA treatment. Although plasma lipid levels were similar between 5-ASA consuming and non-5-ASA groups in mice fed LFD and HFD, improved lipid profile was ...

  2. Rate constants for the reactions of OH with CH3Cl, CH2Cl2, CHCl3, and CH3Br

    Science.gov (United States)

    Hsu, K.-J.; Demore, W. B.

    1994-01-01

    Rate constants for the reactions of OH with CH3Cl, CH2Cl2, CHCl3, and CH3Br have been measured by a relative rate technique in which the reaction rate of each compound was compared to that of HFC-152a (CH3CHF2) and (for CH2Cl2) HFC-161 (CH3CH2F). Using absolute rate constants for HFC-152a and HFC-161, which we have determined relative to those for CH4, CH3CCl3, and C2H6, temperature dependent rate constants of both compounds were derived. The derived rate constant for CH3Br is in good agreement with recent absolute measurements. However, for the chloromethanes all the rate constants are lower at atmospheric temperatures than previously reported, especially for CH2Cl2 where the present rate constant is about a factor of 1.6 below the JPL 92-20 value. The new rate constant appears to resolve a discrepancy between the observed atmospheric concentrations and those calculated from the previous rate constant and estimated release rates.

  3. Photoacoustic-Based-Close-Loop Temperature Control for Nanoparticle Hyperthermia.

    Science.gov (United States)

    Xiaohua, Feng; Fei, Gao; Yuanjin, Zheng

    2015-07-01

    Hyperthermia therapy requires tight temperature control to achieve selective killing of cancerous tissue with minimal damage on surrounding healthy tissues. To this end, accurate temperature monitoring and subsequent heating control are critical. However, an economic, portable, and real-time temperature control solution is currently lacking. To bridge this gap, we present a novel portable close-loop system for hyperthermia temperature control, in which photoacoustic technique is proposed for noninvasive real-time temperature measurement. Exploiting the high sensitivity of photoacoustics, the temperature is monitored with an accuracy of around 0.18 °C and then fed back to a controller implemented on field programmable gate array (FPGA) for temperature control. Dubbed as portable hyperthermia feedback controller (pHFC), it stabilizes the temperature at preset values by regulating the hyperthermia power with a proportional-integral-derivative (PID) algorithm; and to facilitate digital implementation, the pHFC further converts the PID output into switching values (0 and 1) with the pulse width modulation (PWM) algorithm. Proof-of-concept hyperthermia experiments demonstrate that the pHFC system is able to bring the temperature from baseline to predetermined value with an accuracy of 0.3° and a negligible temperature overshoot. The pHFC can potentially be translated to clinical applications with customized hyperthermia system design. This paper can facilitate future efforts in seamless integration of close-loop temperature control solution and various clinical hyperthermia systems.

  4. Flammable refrigerants

    NARCIS (Netherlands)

    Gerwen, R.J.M. van; Verwoerd, M.; Oostendorp, P.A.

    1999-01-01

    Hydrocarbons are promising alternatives for CFC, HCFC and HFC refrigerants. Due to their flammable nature, safety aspects have to be considered carefully. The world-wide situation concerning acceptability and practical application of flammable refrigerants is becoming more and more complex and

  5. Performance and energy saving analysis of a refrigerator using hydrocarbon mixture (HC-R134a) as working fluid

    Science.gov (United States)

    Mohtar, M. N.; Nasution, H.; Aziz, A. A.

    2015-12-01

    The use of hydrocarbon mixture as a working fluid in a refrigerator system is rarely explored. Almost all domestic refrigerators use hydroflourocarbon R134a (HFC-R134a) as refrigerants. In this study, hydrocarbon gas (HC-R134a) is used as the alternative refrigerant to replace HFC-R134a. It has a composition of R290 (56%), R600a (54.39%) and additive (0.1%wt) blended for the trials. The experiments were conducted with 105 g and 52.5 g refrigerant mass charge, subjected to internal heat load of 0, 1, 2, 3 and 4 kg respectively. The study investigates the coefficient of performance of the refrigerator (COPR) and energy consumption. The results show that the use of HC-R134a as the replaceable refrigerant can save energy ranging from 2.04% to 7.09%, as compared to the conventional HFC-R134a refrigerant. Naturally, the COPR improvement and temperature distribution using HC-R134a are much better than HFC-R134a

  6. Proceedings of the 1993 non-fluorocarbon insulation, refrigeration and air conditioning technology workshop

    Energy Technology Data Exchange (ETDEWEB)

    1994-09-01

    Sessions included: HFC blown polyurethanes, carbon dioxide blown foam and extruded polystyrenes, plastic foam insulations, evacuated panel insulation, refrigeration and air conditioning, absorption and adsorption and stirling cycle refrigeration, innovative cooling technologies, and natural refrigerants. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

  7. An overview on non-CO2 greenhouse gases

    NARCIS (Netherlands)

    Pulles, T.; Amstel, van A.R.

    2010-01-01

    Non-CO2 greenhouse gases, included in the Kyoto Protocol, are methane (CH4), nitrous oxide (N2O), hexafluorocarbons (HFC), perfluorinated compounds (PFC) and sulphur hexafluoride (SF6). Together they account for about 25% of the present global greenhouse gas emissions. Reductions in emissions of

  8. 76 FR 71042 - Scott S. Reuben: Debarment Order

    Science.gov (United States)

    2011-11-16

    ... CONTACT: Kenny Shade, Division of Compliance Policy (HFC-230), Office of Enforcement, Office of Regulatory...: Dr. Reuben was a physician licensed by the State of Massachusetts working as an anesthesiologist... Western Massachusetts and maintained an office at the hospital for the purpose of conducting research. Dr...

  9. Emission estimates of HCFCs and HFCs in California from the 2010 CalNex study

    Science.gov (United States)

    Barletta, Barbara; Carreras-Sospedra, Marc; Cohan, Alex; Nissenson, Paul; Dabdub, Donald; Meinardi, Simone; Atlas, Elliot; Lueb, Rich; Holloway, John S.; Ryerson, Thomas B.; Pederson, James; VanCuren, Richard A.; Blake, Donald R.

    2013-02-01

    The CalNex 2010 (California Research at the Nexus of Air Quality and Climate Change) study was designed to evaluate the chemical composition of air masses over key source regions in California. During May to June 2010, air samples were collected on board a National Oceanic and Atmospheric Administration (NOAA) WP-3D aircraft over the South Coast Air Basin of California (SoCAB) and the Central Valley (CV). This paper analyzes six effective greenhouse gases—chlorodifluoromethane (HCFC-22), 1,1-dichloro-1-fluoroethane (HCFC-141b), 1-chloro-1,1-difluoroethane (HCFC-142b), 2-chloro-1,1,1,2-tetrafluoroethane (HCFC-124), 1,1,1,2-tetrafluoroethane (HFC-134a), and 1,1-difluoroethane (HFC-152a)—providing the most comprehensive characterization of chlorofluorocarbon (CFC) replacement compound emissions in California. Concentrations of measured HCFCs and HFCs are enhanced greatly throughout the SoCAB and CV, with highest levels observed in the SoCAB: 310 ± 92 pptv for HCFC-22, 30.7 ± 18.6 pptv for HCFC-141b, 22.9 ± 2.0 pptv for HCFC-142b, 4.86 ± 2.56 pptv for HCFC-124, 109 ± 46.4 pptv for HFC-134a, and 91.2 ± 63.9 pptv for HFC-152a. Annual emission rates are estimated for all six compounds in the SoCAB using the measured halocarbon to carbon monoxide (CO) mixing ratios and CO emissions inventories. Emission rates of 3.05 ± 0.70 Gg for HCFC-22, 0.27 ± 0.07 Gg for HCFC-141b, 0.06 ± 0.01 Gg for HCFC-142b, 0.11 ± 0.03 Gg for HCFC-124, 1.89 ± 0.43 Gg for HFC-134a, and 1.94 ± 0.45 Gg for HFC-152b for the year 2010 are calculated for the SoCAB. These emissions are extrapolated from the SoCAB region to the state of California using population data. Results from this study provide a baseline emission rate that will help future studies determine if HCFC and HFC mitigation strategies are successful.

  10. Chocolate flavanols and skin photoprotection: a parallel, double-blind, randomized clinical trial.

    Science.gov (United States)

    Mogollon, Jaime Andres; Boivin, Catherine; Lemieux, Simone; Blanchet, Claudine; Claveau, Joël; Dodin, Sylvie

    2014-06-27

    Solar ultraviolet (UV) radiation has deleterious effects on the skin, including sunburn, photoaging and cancer. Chocolate flavanols are naturally-occurring antioxidant and anti-inflammatory molecules that could play a role in preventing cutaneous UV damage. We investigated the influence of 12-week high-flavanol chocolate (HFC) consumption on skin sensitivity to UV radiation, measured by minimal erythema dose (MED). We also evaluated skin elasticity and hydration. In this 2-group, parallel, double-blind, randomized controlled trial, 74 women aged 20-65 years and Fitzpatrick skin phototypes I or II were recruited from the general community in Quebec City, for randomization to either HFC (n = 33) or low-flavanol chocolate (LFC) (n = 41). A blocked randomisation (4), considering date of entry, skin type and age as factors, generated a sequentially-numbered allocation list. Study participants and research assistants were blinded. Totally, 30 g of chocolate were consumed daily for 12 weeks, followed by a 3-week washout period. MED was assessed at baseline and at 6, 9, 12 and 15 weeks. Main outcome was changes in MED at week 12. 33 participants in the HFC group and 41 in the LFC group were analyzed with 15 weeks of follow-up. Both groups showed similarly-increased MED at 12 weeks (HFC: 0.0252 ± 0.1099 J/cm2 [mean ± standard deviation (SD)]; LFC: 0.0151 ± 0.1118; mean difference (MD): 0.0100 J/cm2; 95% confidence interval (CI): -0.0417 to 0.0618). However, after 3-week washout, the HFC group presented decreased MED (-0.0248 ± 0.1145) whereas no effect was seen in the LFC group (0.0168 ± 0.1698) (MD: -0.0417; 95% CI: -0.1106 to 0.0272). Net temple elasticity increased slightly but significantly by 0.09 ± 0.12 mm in the HFC group at 12 weeks compared to 0.02 ± 0.12 mm in the LFC group (MD: 0.06; 95% CI: 0.01 to 0.12 ). No significant adverse events were reported. Our study failed to demonstrate a statistically

  11. Chocolate flavanols and skin photoprotection: a parallel, double-blind, randomized clinical trial

    Science.gov (United States)

    2014-01-01

    Background Solar ultraviolet (UV) radiation has deleterious effects on the skin, including sunburn, photoaging and cancer. Chocolate flavanols are naturally-occurring antioxidant and anti-inflammatory molecules that could play a role in preventing cutaneous UV damage. We investigated the influence of 12-week high-flavanol chocolate (HFC) consumption on skin sensitivity to UV radiation, measured by minimal erythema dose (MED). We also evaluated skin elasticity and hydration. Methods In this 2-group, parallel, double-blind, randomized controlled trial, 74 women aged 20–65 years and Fitzpatrick skin phototypes I or II were recruited from the general community in Quebec City, for randomization to either HFC (n = 33) or low-flavanol chocolate (LFC) (n = 41). A blocked randomisation (4), considering date of entry, skin type and age as factors, generated a sequentially-numbered allocation list. Study participants and research assistants were blinded. Totally, 30 g of chocolate were consumed daily for 12 weeks, followed by a 3-week washout period. MED was assessed at baseline and at 6, 9, 12 and 15 weeks. Main outcome was changes in MED at week 12. Results 33 participants in the HFC group and 41 in the LFC group were analyzed with 15 weeks of follow-up. Both groups showed similarly-increased MED at 12 weeks (HFC: 0.0252 ± 0.1099 J/cm2 [mean ± standard deviation (SD)]; LFC: 0.0151 ± 0.1118; mean difference (MD): 0.0100 J/cm2; 95% confidence interval (CI): -0.0417 to 0.0618). However, after 3-week washout, the HFC group presented decreased MED (-0.0248 ± 0.1145) whereas no effect was seen in the LFC group (0.0168 ± 0.1698) (MD: -0.0417; 95% CI: -0.1106 to 0.0272). Net temple elasticity increased slightly but significantly by 0.09 ± 0.12 mm in the HFC group at 12 weeks compared to 0.02 ± 0.12 mm in the LFC group (MD: 0.06; 95% CI: 0.01 to 0.12 ). No significant adverse events were reported. Conclusion Our study failed to

  12. Abundance and sources of atmospheric halocarbons in the Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    F. Schoenenberger

    2018-03-01

    Full Text Available A wide range of anthropogenic halocarbons is released to the atmosphere, contributing to stratospheric ozone depletion and global warming. Using measurements of atmospheric abundances for the estimation of halocarbon emissions on the global and regional scale has become an important top-down tool for emission validation in the recent past, but many populated and developing areas of the world are only poorly covered by the existing atmospheric halocarbon measurement network. Here we present 6 months of continuous halocarbon observations from Finokalia on the island of Crete in the Eastern Mediterranean. The gases measured are the hydrofluorocarbons (HFCs, HFC-134a (CH2FCF3, HFC-125 (CHF2CF3, HFC-152a (CH3CHF2 and HFC-143a (CH3CF3 and the hydrochlorofluorocarbons (HCFCs, HCFC-22 (CHClF2 and HCFC-142b (CH3CClF2. The Eastern Mediterranean is home to 250 million inhabitants, consisting of a number of developed and developing countries, for which different emission regulations exist under the Kyoto and Montreal protocols. Regional emissions of halocarbons were estimated with Lagrangian atmospheric transport simulations and a Bayesian inverse modeling system, using measurements at Finokalia in conjunction with those from Advanced Global Atmospheric Gases Experiment (AGAGE sites at Mace Head (Ireland, Jungfraujoch (Switzerland and Monte Cimone (Italy. Measured peak mole fractions at Finokalia showed generally smaller amplitudes for HFCs than at the European AGAGE sites except for periodic peaks of HFC-152a, indicating strong upwind sources. Higher peak mole fractions were observed for HCFCs, suggesting continued emissions from nearby developing regions such as Egypt and the Middle East. For 2013, the Eastern Mediterranean inverse emission estimates for the four analyzed HFCs and the two HCFCs were 13.9 (11.3–19.3 and 9.5 (6.8–15.1 Tg CO2eq yr−1, respectively. These emissions contributed 16.8 % (13.6–23.3 % and 53.2 % (38.1–84.2

  13. Hollow Fluffy Co3O4 Cages as Efficient Electroactive Materials for Supercapacitors and Oxygen Evolution Reaction.

    Science.gov (United States)

    Zhou, Xuemei; Shen, Xuetao; Xia, Zhaoming; Zhang, Zhiyun; Li, Jing; Ma, Yuanyuan; Qu, Yongquan

    2015-09-16

    Nano-/micrometer multiscale hierarchical structures not only provide large surface areas for surface redox reactions but also ensure efficient charge conductivity, which is of benefit for utilization in areas of electrochemical energy conversion and storage. Herein, hollow fluffy cages (HFC) of Co3O4, constructed of ultrathin nanosheets, were synthesized by the formation of Co(OH)2 hollow cages and subsequent calcination at 250 °C. The large surface area (245.5 m2 g(-1)) of HFC Co3O4 annealed at 250 °C ensures the efficient interaction between electrolytes and electroactive components and provides more active sites for the surface redox reactions. The hierarchical structures minimize amount of the grain boundaries and facilitate the charge transfer process. Thin thickness of nanosheets (2-3 nm) ensures the highly active sites for the surface redox reactions. As a consequence, HFC Co3O4 as the supercapacitor electrode exhibits a superior rate capability, shows an excellent cycliability of 10,000 cycles at 10 A g(-1), and delivers large specific capacitances of 948.9 and 536.8 F g(-1) at 1 and 40 A g(-1), respectively. Catalytic studies of HFC Co3O4 for oxygen evolution reaction display a much higher turnover frequency of 1.67×10(-2) s(-1) in pH 14.0 KOH electrolyte at 400 mV overpotential and a lower Tafel slope of 70 mV dec(-1). HFC Co3O4 with the efficient electrochemical activity and good stability can remain a promising candidate for the electrochemical energy conversion and storage.

  14. Historia y filosofía de las ciencias en la educación polimodal: propuesta para su incorporación al aula History and philosophy of science in science curricula: a proposal for its incorporation in science classes

    Directory of Open Access Journals (Sweden)

    Verónica Guridi

    2004-12-01

    Full Text Available Durante los últimos años se viene enfatizando la necesidad de la incorporación de la Historia y Filosofía de las Ciencias (HFC, en adelante a los currículos de Ciencias. Mucho se ha avanzado respecto de la definición de los marcos teóricos que debieran orientar la incorporación de la HFC en la Enseñanza de las Ciencias, pero sin embargo son pocos los trabajos que muestran propuestas concretas de incorporación de la HFC en las clases de Ciencias. Este trabajo intenta realizar un aporte en el sentido antes mencionado, presentando una propuesta para el tratamiento de un núcleo temático específico correspondiente al primer año Polimodal (orientación Humanidades y Ciencias Sociales en el espacio curricular Físico - Química. El núcleo temático seleccionado corresponde al estudio de la evolución de los modelos atómicos (hasta el modelo atómico de Bohr.In the last few years the necessity of including History and Philosophy of Science (HFC, hereafter in Science Curricula has been emphasised. There have been important advances in theoretical frameworks, which should orient the incorporation of HFC into Science classes. However, there are only a few works that include proposals that show some ways of making this concrete. This work attempts to make a contribution in that direction, presenting a proposal for the treatment of a specific thematic nucleus of the curricular area "Physics-Chemistry". The proposal is designed for the first year of High School Education (with orientation in Humanities and Social Sciences. The selected content corresponds to the study of the evolution of atomic models (up to the model of Bohr.

  15. Electronegative LDL is linked to high-fat, high-cholesterol diet-induced nonalcoholic steatohepatitis in hamsters.

    Science.gov (United States)

    Lai, Yu-Sheng; Yang, Tzu-Ching; Chang, Po-Yuan; Chang, Shwu-Fen; Ho, Shu-Li; Chen, Hui-Ling; Lu, Shao-Chun

    2016-04-01

    The pathogenesis of nonalcoholic steatohepatitis (NASH), like that of atherosclerosis, involves lipid accumulation, inflammation and fibrosis. Recent studies suggest that oxidized LDL (oxLDL) may be a risk factor for NASH, but oxLDL levels were not directly measured in these studies. The aim of this study was to examine whether there was an association between electronegative LDL [LDL(-)], a mildly oxLDL found in the blood, and the development of NASH using two animal models. Golden Syrian hamsters and C57BL/6 mice were fed a high-fat, high-cholesterol (HFC) diet for 6 or 12weeks, then liver lipid and histopathology, plasma lipoprotein profile and LDL(-) levels were examined. The HFC-diet-fed hamsters and mice had similar levels of hepatic lipid but different histopathological changes, with microvesicular steatosis, hepatocellular hypertrophy, inflammation and bridging fibrosis in the hamsters, but only in mild steatohepatitis with low inflammatory cell infiltration in the mice. It also resulted in a significant increase in plasma levels of LDL cholesterol and LDL(-) in hamsters, but only a slight increase in mice. Moreover, enlarged Kupffer cells, LDL(-) and accumulation of unesterified cholesterol were detected in the portal area of HFC-diet-fed hamsters, but not HFC-diet-fed mice. An in vitro study showed that LDL(-) from HFC-diet-fed hamsters induced TNF-α secretion in rat Kupffer cell through a LOX-1-dependent pathway. Our results strongly suggest that LDL(-) is one of the underlying causes of hepatic inflammation and plays a critical role in the development of NASH. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. New Substrate-Guided Method of Predicting Slow Conducting Isthmuses of Ventricular Tachycardia: Preliminary Analysis to the Combined Use of Voltage Limit Adjustment and Fast-Fourier Transform Analysis.

    Science.gov (United States)

    Kuroki, Kenji; Nogami, Akihiko; Igarashi, Miyako; Masuda, Keita; Kowase, Shinya; Kurosaki, Kenji; Komatsu, Yuki; Naruse, Yoshihisa; Machino, Takeshi; Yamasaki, Hiro; Xu, Dongzhu; Murakoshi, Nobuyuki; Sekiguchi, Yukio; Aonuma, Kazutaka

    2018-04-01

    Several conducting channels of ventricular tachycardia (VT) can be identified using voltage limit adjustment (VLA) of substrate mapping. However, the sensitivity or specificity to predict a VT isthmus is not high by using VLA alone. This study aimed to evaluate the efficacy of the combined use of VLA and fast-Fourier transform analysis to predict VT isthmuses. VLA and fast-Fourier transform analyses of local ventricular bipolar electrograms during sinus rhythm were performed in 9 postinfarction patients who underwent catheter ablation for a total of 13 monomorphic VTs. Relatively higher voltage areas on an electroanatomical map were defined as high voltage channels (HVCs), and relatively higher fast-Fourier transform areas were defined as high-frequency channels (HFCs). HVCs were classified into full or partial HVCs (the entire or >30% of HVC can be detectable, respectively). Twelve full HVCs were identified in 7 of 9 patients. HFCs were located on 7 of 12 full HVCs. Five VT isthmuses (71%) were included in the 7 full HVC+/HFC+ sites, whereas no VT isthmus was found in the 5 full HVC+/HFC- sites. HFCs were identical to 9 of 16 partial HVCs. Eight VT isthmuses (89%) were included in the 9 partial HVC+/HFC+ sites, whereas no VT isthmus was found in the 7 partial HVC+/HFC- sites. All HVC+/HFC+ sites predicted VT isthmus with a sensitivity of 100% and a specificity of 80%. Combined use of VLA and fast-Fourier transform analysis may be a useful method to detect VT isthmuses. © 2018 American Heart Association, Inc.

  17. Automation in Siemens fuel manufacturing - the basis for quality improvement by statistical process control (SPC)

    International Nuclear Information System (INIS)

    Drecker, St.; Hoff, A.; Dietrich, M.; Guldner, R.

    1999-01-01

    Statistical Process Control (SPC) is one of the systematic tools to perform a valuable contribution to the control and planning activities for manufacturing processes and product quality. Advanced Nuclear Fuels GmbH (ANF) started a program to introduce SPC in all sections of the manufacturing process of fuel assemblies. The concept phase is based on a realization of SPC in 3 pilot projects. The existing manufacturing devices are reviewed for the utilization of SPC. Subsequent modifications were made to provide the necessary interfaces. The processes 'powder/pellet manufacturing'. 'cladding tube manufacturing' and 'laser-welding of spacers' are located at the different locations of ANF. Due to the completion of the first steps and the experience obtained by the pilot projects, the introduction program for SPC has already been extended to other manufacturing processes. (authors)

  18. Spontaneous brain activity as a biomarker for schizophrenia

    DEFF Research Database (Denmark)

    Anhøj, Simon Jesper; Glenthøj, Birte Yding; Rostrup, Egill

    2014-01-01

    Background and aim: One of the most direct ways to get insight into the functional organization of the human brain is to measure the BOLD-signal with fMRI during rest. This signal is not a random signal but is highly organized in several functional networks (RSN's) believed to be a fundamental...... function of the brain. Very few studies have investigated RSN's in Antipsychotic Naïve First Episode patients (ANFE). In this study we wanted to investigate the potential of using the RSN’s as a biomarker for schizophrenia and for effect of treatment in ANFE patients. Especially, we wanted to test...... subjects were scanned and re-scanned with 10 min resting state fMRI. The analysis contains 50 patients and 50 controls at baseline and 35 patients and 35 controls at follow up. The methods used to measure the functional connectivity are Amplitude of Low Frequency Fluctuations (ALFF), a seed-based approach...

  19. Estrutura das taxocenoses de lagartos nos biomas caatinga, cerrado e Amazônia.

    OpenAIRE

    Costa, Taís Borges

    2015-01-01

    A tese está dividida em três capítulos. No primeiro capítulo apresentamos a lista de espécies de répteis e anfíbios da Estação Ecológica de Aiuaba, Ceará, Brasil. Registramos 36 espécies distribuídas em 19 famílias para a unidade de conservação (15 lagartos, uma anfisbena, 10 serpentes, um quelônio e 9 anfíbios). No segundo capítulo investigamos a existência de padrões de estruturação, averiguando a influência dos fatores ecológicos e históricos, na dieta e no uso de microhábit...

  20. Notat vedr. By- og Landskabsstyrelsens anmodning om en foreløbig vurdering af mulige konsekvenser på udpegningsgrundlaget for Natura 2000 område nr. 162 ved etablering af sommerhuse på Agersø og Orø (Notat til Skov- og Naturstyrelsen)

    DEFF Research Database (Denmark)

    Wind, Peter

    2008-01-01

      By- og Landskabsstyrelsen har med brev af den 30. maj 2008 anmodet Danmarks Miljøundersøgelser om at foretage en screening af mulige konsekvenser på udpegningsgrundlaget som anført ovenfor på baggrund af eksisterende data og viden.   I notatet gør DMU rede for mulige konsekvenser for udpegnings......  By- og Landskabsstyrelsen har med brev af den 30. maj 2008 anmodet Danmarks Miljøundersøgelser om at foretage en screening af mulige konsekvenser på udpegningsgrundlaget som anført ovenfor på baggrund af eksisterende data og viden.   I notatet gør DMU rede for mulige konsekvenser...

  1. EFFECT OF HEAT TREATMENT ON SOYBEAN PROTEIN SOLUBILITY

    Directory of Open Access Journals (Sweden)

    RODICA CĂPRIŢĂ

    2007-05-01

    Full Text Available The use of soybean products in animal feeds is limited due to the presence of antinutritional factors (ANF. Proper heat processing is required to destroy ANF naturally present in raw soybeans and to remove solvent remaining from the oil extraction process. Over and under toasting of soybean causes lower nutritional value. Excessive heat treatment causes Maillard reaction which affects the availability of lysine in particular and produces changes to the chemical structure of proteins resulting in a decrease of the nutritive value. The objective of this study was to evaluate the effect of heating time on the protein solubility. The investigation of the heating time on protein solubility in soybean meal (SBM revealed a negative correlation (r = -0.9596. Since the urease index is suitable only for detecting under processed SBM, the protein solubility is an important index for monitoring SBM quality.

  2. Thermal ageing of duplex stainless steels

    International Nuclear Information System (INIS)

    Massoud, J.P.; Van Duysen, J.C.; Zacharie, G.; Auger, P.; Danoix, F.

    1992-03-01

    The evolution of the mechanical properties of Mobearing anf Mo-free cast duplex stainless steels, induced by long term ageing in the range 300-400 deg C, has been studied in relation with the evolution of their microstructure. The unmixing of the ferritic Fe-Cr-Ni, solid solution by three-dimensional (sponge-like) spinodal decomposition and the precipitation of intermetallic G-phase particles are the main characteristics of this microstructural evolution

  3. Annual Progress Report of the Department of Clinical Investigation, Reports Control Symbol MED-300(R-1), Fiscal Year 1992

    Science.gov (United States)

    1992-10-01

    II. Acid Dissociation HPLC Analysis Of Dissociated iANF. Am J Physiol 261(4):E525-E528, 1991. *Published Abstracts* Agnew J, Freund BJ, Dubose D...1991. (C) Letterie GS, Sakas L: Histology Of Proximal Tubal Obstruction In Cases Of Unsuccessful Tubal Canalization. Fertil Steril 56(5):831-835, 1991...C) (SP) Orthopedic Service Green MR, Christensen KP, Embry R: Use of Magnetic Imaging of the Glenoid Labrum in Anterior Shoulder Instability. Am J

  4. Journal of Genetics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Laboratório de História Natural de Anfíbios Brasileiros, Instituto de Biologia, Universidade Estadual de Campinas, 13083-862, Campinas, SP, Brazil; Departamento de Biologia, Universidade Estadual do Paraná, Campus União da Vitória, 84600-000, União da Vitória, PR, Brazil; Departamento de Zoologia, Universidade ...

  5. 11. Textbeispiele

    OpenAIRE

    Kunze, Rolf-Ulrich

    2017-01-01

    11.1 Seminararbeit zum Thema eines Seminarvortrags: Otto von Bismarck als preußischer Gesandter am Deutschen Bund in Frankfurt am Main, 1851-1859 Warum Bismarck? Man muß gar nicht auf den aus der Zeitgeschichte kommenden sozialgeschichtlichen Siegeszug des biographischen Genre seit einigen Jahren verweisen, um die seit ihren Anfängen offen zu Tage liegenden biographisch-strukturgeschichtlichen Defizite der makrotheoretisch-reduktionistischen politischen Sozialgeschichte Hans-Ulrich Wehlers un...

  6. Hüftendoprothetik - Update

    Directory of Open Access Journals (Sweden)

    Knahr K

    2008-01-01

    Full Text Available Die Implantation eines künstlichen Hüftgelenks zählt zu den erfolgreichsten operativen Eingriffen in den letzten Jahrzehnten. Wo anfänglich die Schwerpunkte der wissenschaftlichen Diskussionen im Prothesendesign, Material und der Verankerung der Implantate im Knochen lagen, gelten diese Probleme heutzutage als weitgehend gelöst. In den letzten Jahren sind vor allem neue Gleitpaarungen mit verbesserten Abriebeigenschaften und die minimal- invasive Gelenkschirurgie die Themen in der modernen Hüftendoprothetik.

  7. to view fulltext PDF

    Indian Academy of Sciences (India)

    led to the hypothesis that any integrable function f in the interval [0, 27r] can be· expanded as a Fourier series: f(x) = I:ane inx. ,. (1) n where an = an(f) is the nth Fourier co- efficient defined by. Reprinted from Current Science. While investigating the proper- ties of heat flow in 1807 the. French scientist Jea n Ba ptiste.

  8. Det ustadige i arkitekturen

    DEFF Research Database (Denmark)

    Ryborg Jørgensen, Thomas

    dermed også en højere grad af selvbesindelse og refleksiv frihed, som måske kan føre os videre og åbne for alternativer. Det er en af min afhandlings væsentlige pointer og anfægtelser, at dette ikke kan ske på baggrund af neutrale, ikke-kvalificerede rum, eller rum determineret af/i en simplificeret...

  9. Vergleichende Untersuchungen zur Widerstandsfähigkeit von \\(\\textit {Apis mellifera}\\) gegenüber \\(\\textit {Varroa destructor}\\) in Deutschland und Südafrika

    OpenAIRE

    Bosch, Christoph (M. Sc.)

    2016-01-01

    Die Milbe \\(\\textit {Varroa destructor}\\) ist einer der bedeutendsten Parasiten der Westlichen Honigbiene \\(\\textit {Apis mellifera}\\). Mit der Ausbreitung entwickelten sich \\(\\it Varroa\\)-resistenzen bei Unterarten von \\(\\textit {A. mellifera}\\). In der vorliegenden Arbeit wurden ausgewählte Faktoren, die zur Widerstandsfähigkeit beitragen können, bei der anfälligen \\(\\textit {A. m. carnica}\\) in Deutschland und der resistenten \\(\\textit {A. m. scutellata}\\) in Südafrika untersucht. Dabei wu...

  10. Effect of nitrendipine on renal function and on hormonal parameters after intravascular iopromide

    DEFF Research Database (Denmark)

    Madsen, J K; Jensen, J W; Sandermann, J

    1998-01-01

    PURPOSE: To evaluate the effect of the low-molecular nonionic radiographic contrast agent iopromide (Ultravist) on renal function, vasoactive peptides (angiotensin II, aldosterone, arginine vasopressin, and atrial natriuretic factor (ANF)), and blood pressure, and to evaluate the influence....... Renal tubular function was estimated from the clearance of lithium. Hormones were measured by radioimmunoassays. RESULTS: Arteriography with iopromide did not change renal function. No differences between the nitrendipine and placebo groups were found in renal hemodynamics, tubular sodium handling...

  11. Effect of Dietary Exogenous Enzyme Supplementation on Enteric Mucosal Morphological Development and Adherent Mucin Thickness in Turkeys

    Directory of Open Access Journals (Sweden)

    Ayuub A. Ayoola

    2015-10-01

    Full Text Available Anti-nutritional factors in feed ingredients (ANF can challenge gut health and reduce nutrient utilization. Birds typically activate their innate immune system as a protective response against the adverse effects of ANF, which often involves the secretion of mucin. Although dietary supplementation of exogenous enzymes are commonly used to alleviate the adverse effects of ANF on apparent nutrient digestibility, little is known about how they affect gut health, particularly in relation to the morphological development and mucin secretion of enteric mucosa. We carried out two trials to examine the effect of dietary supplementation of different types of exogenous enzymes on gut health of by accessing the effect of jejunum morphological development and ileal enteric adherent mucin thickness layer in turkeys. Dietary β-mannanase supplementation reduced ileal adherent mucin thickness layer (804 µg/g vs 823 µg/g; p<0.05, while a commercial blend of Xylanase, Amylase and Protease (XAP reduced ileal adherent mucin layer thickness (589 µg/g vs 740 µg/g; p<0.05; thus reducing the apparent endogenous loss of nutrients. Both enzyme supplements also affected gut morphological characteristics. In comparison to the control treatment, dietary β-mannanase supplementation improved the jejunum tip width (219 vs 161; p<0.05, base width (367 vs 300; p<0.05, surface area (509,870 vs 380, 157; p<0.05 and villi height/crypt depth ratio (7.49 vs 5.70; p<0.05, and XAP improved the crypt depth (p<0.05. In conclusion dietary supplementation of exogenous enzymes may help alleviate the adverse effects of ANF on nutrient utilization by directly or indirectly removing the mucosal irritation that stimulates enteric mucin secretion.

  12. [Effects of Tangshenling Mixture and benazepril on rats with diabetic nephropathy and its mechanism].

    Science.gov (United States)

    He, Xue-Lin; Li, Jian-Ping; Chen, Yi-Ping; Zhang, Zhi-Gang; Lin, Wei-Qin; Chen, Jiang-Hua

    2006-01-01

    To investigate the effects of Tangshenling Mixture (TSLM) and benazepril on rats with diabetic nephropathy (DN) and its mechanism. Diabetic nephropathy was induced in rats by intraperitoneal injection of streptozotocin. Fifty-eight rats with DN were randomly divided into four groups: untreated group, TSLM-treated group, TSLM plus benazepril-treated group and benazepril-treated group. Another seven normal rats were included in normal control group. Then, rats in each group were accordingly given normal saline, TSLM, TSLM plus benazepril and benazepril orally for six weeks respectively. Blood and urine biochemical indexes, plasma atrial natriuretic factor (ANF), pathomorphology of renal tissue, transforming growth factor beta1 (TGF-beta1) and glucose transporter 1 (GLUT1) mRNAs in renal tissue were observed. Both TSLM and benazepril could decrease urinary albumin excretion rates, creatinine clearance and ratio of kidney weight to body weight of the rats with DN as well as reduce the pathological damages of the renal tissues. TSLM could reduce the level of plasma ANF and the expression of GLUT1 mRNA, but had no significant effect on the expression of TGF-beta1 mRNA. Benazepril could reduce the expression of TGF-beta1 mRNA, but had no significant effect on plasma ANF and the expression of GLUT1 mRNA. TSLM can reduce the pathological damages of renal tissues in rats with early-stage DN, and its mechanism may relate to decreasing the level of plasma ANF and the expression of GLUT1 mRNA which is different from that of benazepril. It seems that TSLM has synergetic effect with benazepril.

  13. Estimation of stimulus attenuation in cochlear implants

    CSIR Research Space (South Africa)

    Smit, Jacoba E

    2009-03-01

    Full Text Available -Eikhof nerve fibre model for rat (Schwarz and Eikhof, 1987), but adapted with guinea-pig morphometry. Recently this Generalised Schwarz-Eikhof-Frijns (GSEF) model was adapted for human ANF 8 simulations by employing human morphometric data only (Briaire... and Frijns, 2005; Briaire and Frijns, 2006). This model, however, cannot fully account for the ECAP morphology observed in humans. To facilitate comparison of the differences between an animal and human nerve fibre models, the former guinea-pig version...

  14. Late pancreatic metastasis of renal cell carcinoma with absence of FDG-uptake in PET-CT

    Directory of Open Access Journals (Sweden)

    Elif Karadeli

    2016-03-01

    Full Text Available The primary tumors, which raise isolated pancreas metastases are frequently of renal origin, where colorectal cancer, melanoma, breast and lung cancers and sarcoma are the following causes of metastatic pancreas cancer . In this article, we present a case of pancreas-metastatic renal cell carcinoma with its radiological features, which did not exert anF-18 FDG-uptake in the whole-body positron emission tomography (PET. [Cukurova Med J 2016; 41(0.100: 92-94

  15. El corazón endocrino y el proceso inflamatorio

    Directory of Open Access Journals (Sweden)

    Tsuneo Ogawa

    2013-12-01

    Full Text Available El corazón endocrino, a través de sus hormonas polipéptidas atrial natriuretic factor (ANF o ANP y brain natriuretic peptide (BNP, contribuye a regular la precarga y la poscarga cardiacas. Otras importantes funciones se han descubierto recientemente incluyendo interacciones con el sistema inmunológico. Los niveles plasmáticos de BNP, no así los de ANF, aumentan durante un episodio de rechazo agudo del corazón alotransplantado pero retornan a niveles anteriores al episodio de rechazo después de un tratamiento exitoso del tal rechazo. Este fue el primer indicio que involucró el BNP y el sistema inmunológico. Otras patologías que tienen componentes inflamatorios también se ven acompañadas con cambios en la producción del BNP. El aumento del BNP tiene como base el aumento de la actividad transcripcional del gen inducida por citoquinas y substancias relacionadas. In vitro se puede demostrar que este aumento tiende a modular la actividad inmunológica. Inflamación y cambios hemodinámicos co-existen en la mayoría de las enfermedades cardiovasculares y por ende, es posible que sea beneficioso medir las dos hormonas como biomarcadores de cambios de volumen intravascular (ANF y de estos cambios más inflamación (BNP. Cambios en plasma de ANF relativamente más grandes que aquellos de BNP podrían indicar un deterioro hemodinámico, mientras que cambios importantes en BNP podrían ser indicativos de recrudecimiento del proceso inflamatorio.

  16. Impacts of Sedimentation from Oil and Gas Development on Stream Macroinvertebrates in Two Adjacent Watersheds of the Allegheny National Forest of Northwestern Pennsylvania

    Energy Technology Data Exchange (ETDEWEB)

    Fritz, K.; Harris, S.; Edenborn, H.M.; Sams, J.

    2011-01-01

    Fritz, Kelley'*, Steven Harris', Harry Edenborn2, and James Sams2. 'Clarion University of Pennsylvania, Clarion, PA 16214, 2National Energy Technology Laboratory, U.S. Dept. Energy, Pittsburgh, PA 15236. Impacts a/Sedimentation/rom Oil and Gas Development on Stream Macroinvertebrates in Two Adjacent Watersheds a/the Allegheny National Forest a/Northwestern Pennsylvania - The Allegheny National Forest (ANF), located in northwestern Pennsy Ivania, is a multiuse forest combining commercial development with recreational and conservation activities. As such, portions of the ANF have been heavily logged and are now the subject of widespread oil and gas development. This rapid increase in oil and gas development has led to concerns about sediment runoff from the dirt and gravel roads associated with development and the potential impact on the aquatic biota of the receiving streams. We examined and compared the benthic macroinvertebrate communities in two adjacent watersheds of similar size and topography in the ANF; the Hedgehog Run watershed has no oil and gas development, while the adjacent Grunder Run watershed has extensive oil and gas development. In Hedgehog and Grunder Run, we collected monthly kicknet samples from riffles and glides at two sites from April to October 2010. At the same intervals, we measured standard water quality parameters, including conductivity and turbidity. Preliminary results have indicated much higher turbidity in Grunder Run, but little difference in the diversity and abundance of benthic macro invertebrates inhabiting the two streams.

  17. Analyse in the patients with refractory heart purification treated by continuous blood purification

    International Nuclear Information System (INIS)

    Cai Xun; Huang Chengwen; Huang Zhongliang

    2006-01-01

    Objective: To investigate the application of continuous blood purification (CBP) and the effect of the angiotensin II (Ang II), aldosterone (ALD), atrial natriuretic peptide (ANP) in plasma with refractory heart failure (RHF) treated by CBP. Methods: 35 cases with RHF were treated by CBP. Blood pressure, heart rate, respiration, blood oxygen saturation, blood markers of biochemistry, blood gas analysis, left ventricle ejection fraction (LVEF), cardiac function and Ang II, ALD, ANF in plasma were checked before and after treatment. Results: the systolic pressure, diastolic pressure, heart rate, respiration, serum creatinine, blood urea nitroge, Ang II, ALD, ANF in plasma after treatment were significantly lower than those before treatment of CBP (P 3 - , PaO 2 , LVEF after treatment were significantly higher than those before treatment of CBP (P + , Na + , Cl - of blood serum were recovered normal after treatment, and cardiac function was recovered (P<0.05, P<0.01). Conclusion: In the patients with RHF, CBP can efficiently treat the water-electrolyte disturbance, keep the acid-base balance, decrease the levels of AngII, ALD, ANF in plasma, clear the inflammatory mediator and improve cardiac function. (authors)

  18. Improvements by employee motivation in the manufacture of nuclear fuel assemblies for LWRs

    International Nuclear Information System (INIS)

    Osseforth, E.; Engel, H.

    2000-01-01

    Nuclear fuel assemblies are manufactured on a very high technical level and automation. However there is still a need for more improvement. One of the most important ways is employees motivation, because improvements lives of the ideas, impulses, initiatives and commitments of its employees. It can be realized by the employee himself or a group. Three ways of improvement by employees are mainly implemented at ANF: (i) ANF's 3i - program, based on the standard implementation within Siemens, is the first and an important strategy to improve processes, products and costs. It is to involve all employees and make use of the full potential for improvement The individual employee or a group make a suggestion and receive a commendation depending on the benefits. (ii) Work groups with a high level of responsibility are the second part. The groups mainly organize their work, working time and improvements by themselves. They help each other in job training, are very flexible and able to do also most of the maintenance work. (iii) CIP - groups (Continuous Improvement Process), based on the philosophy of KAMEN is the third strategy. These groups come together to improve all processes in the manufacturing area, also the administration or logistical processes at ANF. CIP - groups are implemented as so called long-term groups, the members are from different levels and departments. By comparing the different ways in order to achieve manufacturing improvements, employees motivation is one of the most important and cheapest part and will increase in significance in future. (author)

  19. Protective Effect of Chitin Urocanate Nanofibers against Ultraviolet Radiation

    Directory of Open Access Journals (Sweden)

    Ikuko Ito

    2015-12-01

    Full Text Available Urocanic acid is a major ultraviolet (UV-absorbing chromophore. Chitins are highly crystalline structures that are found predominantly in crustacean shells. Alpha-chitin consists of microfibers that contain nanofibrils embedded in a protein matrix. Acid hydrolysis is a common method used to prepare chitin nanofibrils (NFs. We typically obtain NFs by hydrolyzing chitin with acetic acid. However, in the present study, we used urocanic acid to prepare urocanic acid chitin NFs (UNFs and examined its protective effect against UVB radiation. Hos: HR-1 mice coated with UNFs were UVB irradiated (302 nm, 150 mJ/cm2, and these mice showed markedly lower UVB radiation-induced cutaneous erythema than the control. Additionally, sunburn cells were rarely detected in the epidermis of UNFs-coated mice after UVB irradiation. Although the difference was not as significant as UNFs, the number of sunburn cells in mice treated with acetic acid chitin nanofibrils (ANFs tended to be lower than in control mice. These results demonstrate that ANFs have a protective effect against UVB and suggest that the anti-inflammatory and antioxidant effects of NFs influence the protective effect of ANFs against UVB radiation. The combination of NFs with other substances that possess UV-protective effects, such as urocanic acid, may provide an enhanced protective effect against UVB radiation.

  20. Transcriptional Profiling of Nitrogen Fixation in Azotobacter vinelandii▿†

    Science.gov (United States)

    Hamilton, Trinity L.; Ludwig, Marcus; Dixon, Ray; Boyd, Eric S.; Dos Santos, Patricia C.; Setubal, João C.; Bryant, Donald A.; Dean, Dennis R.; Peters, John W.

    2011-01-01

    Most biological nitrogen (N2) fixation results from the activity of a molybdenum-dependent nitrogenase, a complex iron-sulfur enzyme found associated with a diversity of bacteria and some methanogenic archaea. Azotobacter vinelandii, an obligate aerobe, fixes nitrogen via the oxygen-sensitive Mo nitrogenase but is also able to fix nitrogen through the activities of genetically distinct alternative forms of nitrogenase designated the Vnf and Anf systems when Mo is limiting. The Vnf system appears to replace Mo with V, and the Anf system is thought to contain Fe as the only transition metal within the respective active site metallocofactors. Prior genetic analyses suggest that a number of nif-encoded components are involved in the Vnf and Anf systems. Genome-wide transcription profiling of A. vinelandiicultured under nitrogen-fixing conditions under various metal amendments (e.g., Mo or V) revealed the discrete complement of genes associated with each nitrogenase system and the extent of cross talk between the systems. In addition, changes in transcript levels of genes not directly involved in N2fixation provided insight into the integration of central metabolic processes and the oxygen-sensitive process of N2fixation in this obligate aerobe. The results underscored significant differences between Mo-dependent and Mo-independent diazotrophic growth that highlight the significant advantages of diazotrophic growth in the presence of Mo. PMID:21724999

  1. Metabolism of 125I-atrial natriuretic factor by vascular smooth muscle cells. Evidence for a peptidase that specifically removes the COOH-terminal tripeptide

    International Nuclear Information System (INIS)

    Johnson, G.R.; Arik, L.; Foster, C.J.

    1989-01-01

    The addition of 200 pM monoiodinated human atrial natriuretic factor-(99-126) (125I-hANF) to cultured bovine aortic smooth muscle cells at 37 degree C resulted in a rapid clearance from the medium (t1/2 approximately 7.5 min). Within 5 min, [125I]iodotyrosine126 (125I-Y), Arg125-[125I]iodotyrosine126 (125I-RY) and Phe124-Arg-[125]iodotyrosine126 (125I-FRY) appeared in the medium. The identities of these degradation products were confirmed by (1) retention time on high performance liquid chromatography (HPLC) relative to standards, (2) products generated by digestion with aminopeptidase M, and (3) the absence of the Met110. Preincubation of the cells with ammonium chloride or chloroquine resulted in a significant increase in the intracellular accumulation of radiolabel, indicative of endocytosis and rapid delivery of 125I-hANF to an acidic intracellular compartment (endosome and/or lysosome). Neither ammonium chloride, chloroquine, nor excess unlabeled hANF blocked the rapid appearance in the medium of 125I-RY or 125I-FRY. Bestatin inhibited the generation of 125I-RY, with a concomitant increase in 125I-FRY, suggesting that the 125I-RY is produced by aminopeptidase action on 125I-FRY. The endopeptidase 24.11 (enkephalinase) inhibitor, SCH 39370, did not inhibit the formation of 125I-FRY. These results provide evidence of a peptidase capable of specifically removing the COOH-terminal tripeptide from 125I-hANF. The COOH-terminal tripeptide, Phe124-Arg-Tyr126, was also isolated from cell digests of hANF by HPLC and its identity confirmed by amino acid analysis. Since it is generally believed that the COOH-terminal tripeptide is critical to many of atrial natriuretic factor-(99-126)'s bioactivities, this enzyme may be involved in the inactivation of atrial natriuretic factor-(99-126) in target tissues

  2. Venezuelan contribution to the ozone layer preservation

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, M.H.; Coltters, R.; Damian, A. [Universidad La Urbina, Caracas (Venezuela). Escuela de Ingenieria Mecanica

    1995-12-31

    There are two ways to solve the problem of the ozone layer destruction in the upper atmosphere by the harmful chlorine which comes from CFC refrigerants and from aerosols. The first one is to replace the old equipment by new ones which work with non-contaminant refrigerants and the second solution is to establish a conversion program according to the Montreal Protocol and the Vienna Convention. According to this, some Venezuelan Companies are beginning to replace the car`s air conditioning equipment, and others like CVG-SIDOR are making an accelerated program for its central air conditioning system. Another company, C.A. Metro de Caracas, has made a progressive program for the replacement of Freon R-11 and R-12 for HFC 123 and HFC-134a respectively. The results indicate that the most economical solution is to replace these refrigerants instead of replacing the equipment completely.

  3. Mining and global environmental challenges

    Energy Technology Data Exchange (ETDEWEB)

    Greeff, J C; Bailey-McEwan, M [Chamber of Mines of South Africa, Johannesburg (South Africa)

    1992-04-01

    At least half of South Africa's gold production is presently dependent on CFC11 an CFC12 as refrigerants in water chilling machines used in cooling the underground workings. The South African Government will ratify the revised Montreal Protocol on substances that deplete the ozone layer which will mean CFCs will have to be phased out probably by 1997. HFC134 or HFC22 are possible replacements for CFC but present costs of converting machines are high. The article goes on to discuss the contribution of CFCs and CO{sub 2} to global warming and model simulations and predictions of climate change. Likely effects of growing concern about global warming on the coal mining industry are the possible limitations on the use of coal and the increased need for clean coal technology. 12 refs., 5 figs., 3 tabs.

  4. A binary mixture operated heat pump

    International Nuclear Information System (INIS)

    Hihara, E.; Saito, T.

    1991-01-01

    This paper evaluates the performance of possible binary mixtures as working fluids in high- temperature heat pump applications. The binary mixtures, which are potential alternatives of fully halogenated hydrocarbons, include HCFC142b/HCFC22, HFC152a/HCFC22, HFC134a/HCFC22. The performance of the mixtures is estimated by a thermodynamic model and a practical model in which the heat transfer is considered in heat exchangers. One of the advantages of binary mixtures is a higher coefficient of performance, which is caused by the small temperature difference between the heat-sink/-source fluid and the refrigerant. The mixture HCFC142b/HCFC22 is promising from the stand point of thermodynamic performance

  5. Low-temperature anomalies of photoinduced second harmonic generation in skutterudites

    International Nuclear Information System (INIS)

    Viennois, R; Kityk, I V; Terki, F; Charar, S; Muntzer, A; Kasperczyk, J; Ravot, D; Tedenac, J C

    2003-01-01

    Photoinduced second harmonic generation (PISHG) was found in skutterudite compounds of CeFe 4 Sb 12 and Ce 0.7 Fe 3.5 Ni 0.5 Sb 12 . Measurements versus temperature, pump-probe delaying time and external magnetic field were performed. The studied compounds belong to moderate heavy fermion compounds (HFC) in the ground state. The PISHG signals appear at 6.8 and 4.9 K for CeFe 4 Sb 12 and Ce 0.7 Fe 3.5 Ni 0.5 Sb 12 , respectively. We suspect that these signals are due to anharmonic electron-phonon interactions creating a charge density non-centrosymmetry. The observed effects are caused either by a possible phase transition or by drastic changes in the electron structure of the HFC with decreasing temperature

  6. The sectoral trends of multigas emissions inventory of India

    DEFF Research Database (Denmark)

    Garg, A.; Shukla, P.R.; Kapshe, M.

    2006-01-01

    This paper provides the trends of greenhouse gas (GHG) and local air pollutant emissions of India for 1985-2005. The GHGs covered are six Kyoto gases, namely carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), perfluorocarbons (PFCs), hydrofluorocarbons (HFCs) and sulfur hexafluoride (SF6...... in the same sector is the major source of N2O emissions. PFC emissions are dominated by C2F6 and CF4 emissions from aluminum production. The majority of HFC emissions are contributed by HFC-23, a by-product during the production of HCFC-22 that is widely used in refrigeration industry. CO emissions have...... dominance from biomass burning. Particulate emissions are dominated by biomass burning (residential sector), road transport and coal combustion in large plants. These varied emission patterns provide interesting policy links and disjoints, such as-which and where mitigation flexibility for the Kyoto gases...

  7. Release and attenuation of fluorocarbons in landfills

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Scheutz, Charlotte

    2003-01-01

    Several halocarbons with very high global warming and ozone depleting potentials have been used as blowing agent for insulation foam in refrigerators and freezers. Many appliances are shredded after the end of their useful life. Release experiments carried out in the laboratory on insulation foam...... blown with CFC-11, HCFC-141b, HFC- 134a, and HFC-245fa revealed that most of the blowing agent is not released to the atmosphere during a six-week period following the shredding process. The fraction which is released in the six-week period is highly dependent on how fine the foam is shredded....... The residual blowing agent remaining after the six-week period may be very slowly released if the integrity of the foam particles with respect to diffusional properties is kept after disposal of the foam waste in landfills. Laboratory experiments simulating attenuation processes in the landfilled waste...

  8. Modified Peng-Robinson Equation of State for Pure and Mixture Refrigerants with R-32,R-125 and R-134a

    Science.gov (United States)

    Ll, Jin; Sato, Haruki; Watanabe, Koichi

    On the basis of critically-evaluated thermodynamic property data among those recently published, a new Peng-Robinson equation of state for the HFC refrigerants,R-32,R-125 and R-134a,has be end eveloped so as to represent the VLE properties in the vapor-liquid coexisting phase at temperatures 223K-323K. In accord with a challenge to correlate the binary and/or ternary interatction parameters as functions of temperature, we have also applied the present modified Peng-Robinson equation of state to the promising alternative HFC refrigerant mixtures, i.e., R-32/125,R-32/134a and R-32/125/134a systems. The developed equation of state improves significantly its effectiveness for practical engineering property calculations at refrigerantion and air-conditioning industries in comparison with conventional Peng-Robinson equation.

  9. Analysis of Human Errors in Japanese Nuclear Power Plants using JHPES/JAESS

    International Nuclear Information System (INIS)

    Kojima, Mitsuhiro; Mimura, Masahiro; Yamaguchi, Osamu

    1998-01-01

    CRIEPI (Central Research Institute for Electric Power Industries) / HFC (Human Factors research Center) developed J-HPES (Japanese version of Human Performance Enhancement System) based on the HPES which was originally developed by INPO to analyze events resulted from human errors. J-HPES was systematized into a computer program named JAESS (J-HPES Analysis and Evaluation Support System) and both systems were distributed to all Japanese electric power companies to analyze events by themselves. CRIEPI / HFC also analyzed the incidents in Japanese nuclear power plants (NPPs) which were officially reported and identified as human error related with J-HPES / JAESS. These incidents have numbered up to 188 cases over the last 30 years. An outline of this analysis is given, and some preliminary findings are shown. (authors)

  10. Field and sample history dependence of the compensation temperature in Sm0.97Gd0.03Al2

    International Nuclear Information System (INIS)

    Vaidya, U.V.; Rakhecha, V.C.; Sumithra, S.; Ramakrishnan, S.; Grover, A.K.

    2007-01-01

    We present magnetization data on three polycrystalline specimens of Sm 0.97 Gd 0.03 Al 2 : (1) as-cast (grainy texture), (2) powder, and (3) re-melted fast-quenched (plate). The data are presented for nominally zero- (ZFC) and high-field-cooling (HFC) histories. A zero cross-over in magnetization curve at some temperature T=T 0 was seen in ZFC data on grainy and powder samples, but not in the plate sample. At fields surpassing magnetocrystalline anisotropy, a 4f magnetic moment flip was still evidenced by HFC data in all samples at a compensation temperature T comp , which must necessarily be treated as distinct from T 0 (T 0 may not even exist). Proper understanding of T comp should take account of thermomagnetic history effects

  11. Insertion of historical and philosophical components in disciplines of the natural sciences in the medium teaching: reflections from the historiographies controversies among Kuhn and Lakatos

    Directory of Open Access Journals (Sweden)

    Osmar Henrique Moura da Silv

    2010-12-01

    Full Text Available The incorporation of historical and philosophical elements in disciplines of natural sciences of the high school has been reaching defended in the specific literature and critics improved visions concerning the use of the History and Philosophy of the Science (HFC for didactic ends. In that sense, the discussions are important since ponder influences in the orientation of curricula of significant portion of the undergraduate teaching. Worrying about such discussions, this study put reflections about de historiographies controversies among Kuhn and Lakatos whose educational implications allow support to a tendency of the use of HFC as resources not to obtain completely authentic historical reconstructions, but to favor intentions of to develop and to project didactic solutions in that the pedagogy doesn't need to submit itself to the History.

  12. Denmark's national inventory report 2008 - Submitted under the United Nations framework convention on climate change, 1990-2006. Emission inventories

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Ole-Kenneth; Lyck, E; Hjorth Mikkelsen, M [and others

    2008-05-15

    This report is Denmark's National Inventory Report reported to the Conference of the Parties under the United Nations Framework Convention on Climate Change (UNFCCC) due by 15 April 2008. The report contains information on Denmark's inventories for all years' from 1990 to 2006 for CO{sub 2}, CH{sub 4}, N{sub 2}O, HFC{sub s}, PFC{sub s} and SF{sub 6}, CO, NMVOC, SO{sub 2}. (au)

  13. A Novel Evolutionary Engineering Design Approach for Mixed-Domain Systems

    DEFF Research Database (Denmark)

    Fan, Zhun; Hu, J.; Seo, K.

    2004-01-01

    This paper presents an approach to engineering design of mixed-domain dynamic systems. The approach aims at system-level design and has two key features: first, it generates engineering designs that satisfy predefined specifications in an automatic manner; second, it can design systems belonging ...... often encountered in evolutionary computation, a HFC (Hierarchical Fair Competition) model is adopted in this work. Examples of an analog filter design and a MEM filter design illustrate the application of the approach....

  14. Evaporation of new refrigerants on tube with improved surfaces. Final report. Appendices: A, B, C, D, E and F; Evaporation de nouveaux refrigerants sur des tubes a surface amelioree. Rapport final. Annexes: A, B, C, D, E et F

    Energy Technology Data Exchange (ETDEWEB)

    Kattan, N.; Favrat, D.; Thome, J. R.; Nidegger, E.; Zuercher, O. [Ecole Polytechnique Federale, Lab. d` Energetique Industrielle (LENI), Lausanne (Switzerland)

    1995-07-15

    The substitution of old refrigerants in refrigeration systems, heat pumps and organic Rankine cycles for heat recovery, request a good knowledge of heat transfer properties of substitute fluids. The test measurements in LENI test facility (concentric tubes with water flowing in a counter-current flow) with new refrigerants like HFC134a, HCFC123, R-402A, have established a new data bank with new refrigerants, a comparison with old refrigerants like CFC11, CFC12 CFC/HCFC502 and with existent correlations. Correlations were programmed to calculate and compare heat transfer coefficient during the tests. To develop a new correlation based on flow regimes, a high speed Sony video tape camera is used to observe and identify flow patterns. Important images are captured, digitalized, stored for later analysis and sent to a color plotter. Several flow pattern maps were programmed and compared to flow regimes observed on the test rig. Local flow boiling heat transfer coefficients were measured for HFC134a and HCFC123 evaporating inside a microfin tube. In addition, microheat transfer augmentation relative to plain tube test data was investigated. The presence of oil in the evaporator has an effect on heat transfer coefficient. Local flow boiling heat transfer coefficients were measured for refrigerant HFC134a-oil ester (Mobil EAL Arctic 68). A new thermodynamic approach for modeling mixtures of refrigerants and lubricating oils is developed. A very high accuracy, straight vibrating tube type of density flowmeter is used to measure oil concentrations of flowing HFC134a-oil mixtures. (author) figs., tabs., refs.

  15. Evaporation of new refrigerants on tubes with improved surfaces; Evaporation de nouveaux refrigerants sur des tubes a surface amelioree

    Energy Technology Data Exchange (ETDEWEB)

    Kattan, N.; Favrat, D.; Thome, J. R.; Nidegger, E.; Zuercher, O. [Ecole Polytechnique Federale, Lab. d` Energetique Industrielle (LENI), Lausanne (Switzerland)

    1995-07-15

    The substitution of old refrigerants in refrigeration systems, heat pumps and organic Rankine cycles for heat recovery, request a good knowledge of heat transfer properties of substitute fluids. The test measurements in LENI test facility (concentric tubes with water flowing in a counter-current flow) with new refrigerants like HFC134a, HCFC123, R-404A, R-402A, have established a new data bank with new refrigerants, a comparison with old refrigerants like CFC11, CFC12 CFC/HCFC502 and with existent correlations. Correlations were programmed to calculate and compare heat transfer coefficient during the tests. To develop a new correlation based on flow regimes, a high speed Sony video tape camera is used to observe and identify flow patterns. Important images are captured, digitalized, stored for later analysis and sent to a color plotter. Several flow pattern maps were programmed and compared to flow regimes observed on the test rig. Local flow boiling heat transfer coefficients were measured for HFC134a and HCFC123 evaporating inside a microfin tube. In addition, microfin heat transfer augmentation relative to plain tube test data was investigated. The presence of oil in the evaporator has an effect on heat transfer coefficient. Local flow boiling heat transfer coefficients were measured for refrigerant HFC134a-oil ester (Mobil EAL Arctic 68). A new thermodynamic approach for modeling mixtures of refrigerants and lubricating oils is developed. A very high accuracy, straight vibrating tube type of density flowmeter is used to measure oil concentrations of flowing HFC134a-oil mixtures. (author) 28 figs., 25 refs.

  16. Influence of GSTM1 and GSTT1 genotypes and confounding factors on the frequency of sister chromatid exchange and micronucleus among road construction workers.

    Science.gov (United States)

    Kumar, Anil; Yadav, Anita; Giri, Shiv Kumar; Dev, Kapil; Gautam, Sanjeev Kumar; Gupta, Ranjan; Aggarwal, Neeraj

    2011-07-01

    In the present study, we have investigated the influence of polymorphism of GSTM1 and GSTT1 genes and confounding factors such as age, sex, exposure duration and consumption habits on cytogenetic biomarkers. Frequency of sister chromatid exchanges (SCEs), high frequency cell (HFC) and cytokinesis blocked micronuclei (CBMN) were evaluated in peripheral blood lymphocytes of 115 occupationally exposed road construction workers and 105 unexposed individuals. The distribution of null and positive genotypes of glutathione-S transferase gene was evaluated by multiplex PCR among control and exposed subjects. An increased frequency of CBMN (7.03±2.08); SCE (6.95±1.76) and HFC (6.28±1.69) were found in exposed subjects when compared to referent (CBMN - 3.35±1.10; SCE - 4.13±1.30 and HFC - 3.98±1.56). These results were found statistically significant at p<0.05. When the effect of confounding factors on the frequency of studied biomarkers was evaluated, a strong positive interaction was found. The individuals having GSTM1 and GSTT1 null genotypes had higher frequency of CBMN, SCE and HFC. The association between GSTM1 and GSTT1 genotypes and studied biomarkers was found statistically significant at p<0.05. Our findings suggest that individuals having null type of GST are more susceptible to cytogenetic damage by occupational exposure regardless of confounding factors. There is a significant effect of polymorphism of these genes on cytogenetic biomarkers which are considered as early effects of genotoxic carcinogens. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. International research into chlorofluorocarbon (CFC) alternatives

    Energy Technology Data Exchange (ETDEWEB)

    Marseille, T.J.; Shankle, D.L.; Thurman, A.G.

    1992-05-01

    Selected researchers from 21 countries were queried through questionnaires about their current and planned research activities. The results of the survey show that the majority of research being conducted by the respondents is devoted to investigating the hydrogenated fluorocarbon HFC-134a as a replacement for CFC-12 in refrigeration applications. The main issue with this alternative is identifying compatible lubricants that do not reduce its effectiveness.

  18. New botanical drug, HL tablet, reduces hepatic fat as measured by magnetic resonance spectroscopy in patients with nonalcoholic fatty liver disease: A placebo-controlled, randomized, phase II trial.

    Science.gov (United States)

    Jeong, Jae Yoon; Sohn, Joo Hyun; Baek, Yang Hyun; Cho, Yong Kyun; Kim, Yongsoo; Kim, Hyeonjin

    2017-08-28

    To evaluate the efficacy and safety of HL tablet extracted from magnolia officinalis for treating patients with nonalcoholic fatty liver disease (NAFLD). Seventy-four patients with NAFLD diagnosed by ultrasonography were randomly assigned to 3 groups given high dose (400 mg) HL tablet, low dose (133.4 mg) HL tablet and placebo, respectively, daily for 12 wk. The primary endpoint was post-treatment change of hepatic fat content (HFC) measured by magnetic resonance spectroscopy. Secondary endpoints included changes of serum aspartate aminotransferase, alanine aminotransferase (ALT), cholesterol, triglyceride, free fatty acid, homeostasis model assessment-estimated insulin resistance, and body mass index (BMI). The mean HFC of the high dose HL group, but not of the low dose group, declined significantly after 12 wk of treatment (high dose vs placebo, P = 0.033; low dose vs placebo, P = 0.386). The mean changes of HFC from baseline at week 12 were -1.7% ± 3.1% in the high dose group ( P = 0.018), -1.21% ± 4.97% in the low dose group ( P = 0.254) and 0.61% ± 3.87% in the placebo group (relative changes compared to baseline, high dose were: -12.1% ± 23.5%, low dose: -3.2% ± 32.0%, and placebo: 7.6% ± 44.0%). Serum ALT levels also tended to decrease in the groups receiving HL tablet while other factors were unaffected. There were no moderate or severe treatment-related safety issues during the study. HL tablet is effective in reducing HFC without any negative lipid profiles, BMI changes and adverse effects.

  19. Social accountability in primary health care in West and Central Africa: exploring the role of health facility committees.

    Science.gov (United States)

    Lodenstein, Elsbet; Mafuta, Eric; Kpatchavi, Adolphe C; Servais, Jean; Dieleman, Marjolein; Broerse, Jacqueline E W; Barry, Alpha Amadou Bano; Mambu, Thérèse M N; Toonen, Jurrien

    2017-06-13

    Social accountability has been emphasised as an important strategy to increase the quality, equity, and responsiveness of health services. In many countries, health facility committees (HFCs) provide the accountability interface between health providers and citizens or users of health services. This article explores the social accountability practices facilitated by HFCs in Benin, Guinea and the Democratic Republic of Congo. The paper is based on a cross-case comparison of 11 HFCs across the three countries. The HFCs were purposefully selected based on the (past) presence of community participation support programs. The cases were derived from qualitative research involving document analysis as well as interviews and focus group discussions with health workers, citizens, committee members, and local authorities. Most HFCs facilitate social accountability by engaging with health providers in person or through meetings to discuss service failures, leading to changes in the quality of services, such as improved health worker presence, the availability of night shifts, the display of drug prices and replacement of poorly functioning health workers. Social accountability practices are however often individualised and not systematic, and their success depends on HFC leadership and synergy with other community structures. The absence of remuneration for HFC members does not seem to affect HFC engagement in social accountability. Most HFCs in this study offer a social accountability forum, but the informal and non-systematic character and limited community consultation leave opportunities for the exclusion of voices of marginalised groups. More inclusive, coherent and authoritative social accountability practices can be developed by making explicit the mandate of HFC in the planning, monitoring, and supervision of health services; providing instruments for organising local accountability processes; strengthening opportunities for community input and feedback; and

  20. Rate constants for the gas-phase reactions of OH radicals with CH3CHF2 and CHCl2CF3 over the temperature range 295-388 K

    DEFF Research Database (Denmark)

    Nielsen, O.J.

    1991-01-01

    be fit to the Arrhenius expressions: k(OH + HFC-152a) = 3.9 X 10(-12) exp[(-1370 +/- 260)/T] cm3 molecule-1 s-1 and k(OH + HCFC-123) = 1.1 X 10(-12) X exp[(-940 +/- 200)/T] cm3 molecule-1 s-1. The results are compared to the available literature data and discussed in terms of reactivity trends...

  1. Public Role and Engagement in Counterterrorism Efforts: Implications of Israeli Practices for the U.S.

    Science.gov (United States)

    2009-04-02

    radiation exposure to the thyroid gland helping prevent thyroid cancer during a radiological event. The NRC has provided potassium iodide tablets to...Israeli public to tune into Galatz for information during an emergency. After the Second Lebanon War of 2006, HFC established a “ silent ” radio...station. Three FM stations broadcast continuously throughout the day but remain silent , with nothing being broadcast over the airwaves. In the event of an

  2. Experimental Performance Investigation of New Low-GWP Refrigerants for Use in Two-Phase Evaporative Cooling of Electronics

    OpenAIRE

    Nicolette-Baker, Alexis; Garr, Elizabeth; Sathe, Abhijit; O'Shaughnessey, Steve

    2014-01-01

    With growing global warning concerns on the current breed of HFC refrigerants, a search for more environmentally-friendly fluids has already begun. Potential alternatives to replace R134a should have significantly lower global warming potential (GWP), operate at similar system pressures, and maintain all other advantages of R134a (non-flammability, dielectric properties, etc.). This study investigates four possible alternatives that have been identified by AHRI in its Low-GWP Alternative Refr...

  3. Application of the Backward-Smoothing Extended Kalman Filter to Attitude Estimation and Prediction using Radar Observations

    Science.gov (United States)

    2009-06-01

    Pressure (R) Figure 2.9 Aerodynamic drag acting at the centroid of each surface element This approach avoids time- consuming repetitive evaluation of...5. Update the state estimate with the latest measurement yfe (37 p. 210) xfe(tfc) = **_!&) + Kfc (yfe - hfc) (3.72) In some cases it is necessary to...in XELIAS can be a rather challenging and time consuming task, depending on the complexity of the target being analyzed. 4. According to the XELIAS

  4. Alternative Refrigerant Evaluation for High-Ambient Temperature Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, Omar [ORNL; Munk, Jeffrey D [ORNL; Shrestha, Som S [ORNL; Linkous, Randall Lee [ORNL; Goetzler, William [Navigant Consulting Inc.; Guernsey, Matt [Navigant Consulting Inc.; Kassuga, Theo [Navigant Consulting Inc.

    2015-08-01

    The Oak Ridge National Laboratory (ORNL) High-Ambient Temperature Testing Program for Low-GWP Refrigerants aims to develop an understanding of the performance of low-Global Warming Potential (low-GWP) alternatives to Hydrochlorofluorocarbon (HCFC) and Hydrofluorocarbon (HFC) refrigerants in mini-split air conditioners under high ambient temperature conditions. This interim working paper describes the parties involved, the alternative refrigerants selection process, the test procedures, and the preliminary results.

  5. Experimental Results For Hydrocarbon Refrigerant Vaporization In Brazed Plate Heat Exchangers at High Pressure

    OpenAIRE

    Desideri, Adriano; Schmidt Ommen, Torben; Wronski, Jorrit; Quoilin, Sylvain; Lemort, Vincent; Haglind, Fredrik

    2016-01-01

    In this contribution, the experimental heat transfer coefficient  and the pressure drop measured during HFC refrigerants vaporization inside small brazed plate heat exchanger (PHE) at typical evaporation temperature for organic Rankine cycle systems for low thermal energy quality applications are presented. Scientific work focusing on the heat transfer in PHEs has been carried out since the late 19th century. More recent publications have been focusing on vaporization and condensation of ref...

  6. Carbon Dioxide as Secondary Refrigerant in Supermarkets

    DEFF Research Database (Denmark)

    Knudsen, Hans Jørgen Høgaard

    Resume I forbindelse med udfasning af HCFC- og HFC-kølemidlerne er opstået stor interesse for anvendelse af naturlige kølemidler samt indirekte køling i forbindelse med køling i supermarkeder. Som sekundært kølemiddel med faseskift kan kuldioxid anvendes. I supermarkeder med køleanlægget placeret...

  7. Development of a Refractory High Entropy Superalloy (Postprint)

    Science.gov (United States)

    2016-03-17

    hardened with HfC precipitates [2], Co-Re- or Co-Al-W-based alloys [3] or two-phase ( FCC + L12) refractory superalloys based on platinum group metals...Ni-based superalloys consisting of cuboids with the ordered L12 structure embedded in an FCC solid-solution matrix. Based on this microstructural...and 5). A comparison of the average atomic radii with the measured lattice parameters allows us to conclude that the disordered BCC phase forming

  8. Alternative Refrigerant Evaluation for High-Ambient-Temperature Environments: R-22 and R-410A Alternatives for Rooftop Air Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shen, Bo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Linkous, Randall Lee [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Goetzler, William [Navigant Consulting Inc., Burlington, MA (United States); Guernsey, Matt [Navigant Consulting Inc., Burlington, MA (United States); Bargach, Youssef [Navigant Consulting Inc., Burlington, MA (United States)

    2016-09-01

    The Oak Ridge National Laboratory (ORNL) High-Ambient-Temperature Evaluation Program for Low-Global Warming Potential (Low-GWP) Refrigerants aims to develop an understanding of the performance of low-GWP alternative refrigerants relative to hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) refrigerants in packaged or Rooftop Unit (RTU) air conditioners under high-ambient-temperature conditions. This final report describes the parties involved, the alternative refrigerants selection process, the test procedures, and the final results.

  9. Alternative Refrigerant Evaluation for High-Ambient-Temperature Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Munk, Jeffrey D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Linkous, Randall Lee [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Goetzler, William [Navigant Consulting Inc., Burlington, MA (United States); Guernsey, Matt [Navigant Consulting Inc., Burlington, MA (United States); Kassuga, Theo [Navigant Consulting Inc., Burlington, MA (United States)

    2015-10-01

    The Oak Ridge National Laboratory (ORNL) High-Ambient-Temperature Evaluation Program for low– global warming potential (Low-GWP) Refrigerants aims to develop an understanding of the performance of low-GWP alternative refrigerants to hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) refrigerants in mini-split air conditioners under high-ambient-temperature conditions. This final report describes the parties involved, the alternative refrigerant selection process, the test procedures, and the final results.

  10. Greenhouse effect: an issue for the refrigeration and air conditioning sector; Effet de serre: quelle problematique pour le froid et le conditionnement de l`air?

    Energy Technology Data Exchange (ETDEWEB)

    Billiard, F. [Institut International du Froid, 75 - Paris (France)

    1997-12-31

    The principles of greenhouse effect and the greenhouse gas main direct and indirect emission sources due to refrigeration and air conditioning systems are first reviewed. Evolution scenarios from 1992 to 2020 and 2100 for the emissions of CFC, HCFC and HFC are presented and related to the Kyoto protocol project limitations; technical improvements in refrigerating and air conditioning systems (lower refrigerant utilization, fluid confinement, alternative technologies, natural refrigerant utilization, etc.) could lead to substantial diminutions of these greenhouse gases

  11. PRELIMINARY DATA ON FUMONISINS PRESENCE IN PIG LIVER

    Directory of Open Access Journals (Sweden)

    G. Pagliuca

    2009-12-01

    Full Text Available Mycotoxins are heterogeneous chemical compounds characterized by a low molecular weight and synthesized by the secondary metabolism of different molds. Fumonisins are water-soluble mycotoxins produced by Fusarium species spoiling corn and derived products. These mycotoxins can enter the food chain also through the consumption of meat of exposed animals. Fumonisins and their metabolites have been associated with several animal and human diseases. They are suspected risk factors for esophageal and liver cancers, neural tube defects and cardiovascular problems. Improved methods are needed to accurately assess fumonisin concentrations in food from vegetable and animal origin to prevent acute and chronic human exposure. The aim of the present work was to develop a sensitive and selective method for quantification and unambiguous identification of fumonisin B1 (FB1, fumonisin B2 (FB2 and their complete hydrolyzed products (HFB1 and HFB2, in order to determine their presence in pig liver. Furthermore, the developed method was applied, in order to test its efficacy, on liver samples of weaned piglets fed a diet in compliance with the FB1 and FB2 contamination limits set by EU. All the samples showed the presence of at least one of the analytes. In particular FB1 was found in 5 out of 7 samples and the average level of contamination found was 28 ppb.

  12. Multiphase Nano-Composite Coatings for Achieving Energy Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Nainaparampil, Jose

    2012-03-26

    UES Inc. and ANL teamed in this work to develop novel coating systems for the protection of surfaces from thermal degradation mainly in two applications; Machining and Die casting. These coatings were specifically designed for the purpose by incorporating required material phases and the overall architecture, which led to reduce the energy usage and increase efficiency of the operations. Following the UES/ANL's feasibility work, the coatings were developed utilizing High power impulse magnetron sputtering (HiPMS) and Large area filtered arc deposition (LAFAD) techniques. Toughness, hardness and oxidation resistance: contrasting qualities have been mixed in the right proportion to attain the suitable material characteristic for the cause. Hafnium diboride (HfB2) based materials provided such a system and its properties were tamed to attain the right combination of toughness and hardness by working on the microstructure and architecture of coatings. An effective interfacing material (graded concentrations of topcoat) was also achieved in this work to provide the required adhesion between the substrate and the coating. Combination of an appropriate bond coat and a functional top coat provided the present thermal degradation resistant coating for cutting tools and die-casting applications. Laboratory level performance tests and industrial level application tests by partner companies (Beta Site Testing) were used for the development of these coatings.

  13. Multiscale Modeling of UHTC: Thermal Conductivity

    Science.gov (United States)

    Lawson, John W.; Murry, Daw; Squire, Thomas; Bauschlicher, Charles W.

    2012-01-01

    We are developing a multiscale framework in computational modeling for the ultra high temperature ceramics (UHTC) ZrB2 and HfB2. These materials are characterized by high melting point, good strength, and reasonable oxidation resistance. They are candidate materials for a number of applications in extreme environments including sharp leading edges of hypersonic aircraft. In particular, we used a combination of ab initio methods, atomistic simulations and continuum computations to obtain insights into fundamental properties of these materials. Ab initio methods were used to compute basic structural, mechanical and thermal properties. From these results, a database was constructed to fit a Tersoff style interatomic potential suitable for atomistic simulations. These potentials were used to evaluate the lattice thermal conductivity of single crystals and the thermal resistance of simple grain boundaries. Finite element method (FEM) computations using atomistic results as inputs were performed with meshes constructed on SEM images thereby modeling the realistic microstructure. These continuum computations showed the reduction in thermal conductivity due to the grain boundary network.

  14. Substitutes for potent green house gases. HFCs, PFCs and SF{sub 6}. Status report

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, P.H. [Dansk Teknologisk Institut (Denmark)

    1997-12-31

    CFCs (halogenated chlorofluorocarbons), HCFCs (hydrochlorofluorocarbons), HFCs (hydrofluorocarbons), PFCs (fluorocarbons) and SF{sub 6} (sulphur hexafluoride) are all artificial substances which were not to be found in nature until recently. In 1995 the Danish consumption of HFC substances was approximately 740 tonnes, where the corresponding amount of SF{sub 6} was about 17 tonnes. If the entire amount of these substances was released to to the atmosphere, the resulting impact would correspond to an increased emission of greenhouse gases, corresponding to approximately 1.5 million tonnes of CO{sub 2}. HFC substances would account for 73%, SF{sub 6} with 25% and PFC for 1%. This corresponds to approximately 2.6% of the Danish CO{sub 2} emission (nearly 60 million tonnes per year). This corresponds to about half of the aimed 6% reduction of CO{sub 2} emission attained by introduction of mandatory green taxes on CO{sub 2}. According to experience from the CFC programme it is possible to recover some CFC and send it to controlled destruction. From 1993 to 1996 the refrigeration industry, for instance, has returned a total amount of 163 tonnes of CFC refrigerant through the KMO organization (Koelebranchens Miljoe Ordning). Most of this has been destroyed and a small amount has been purified and recycled afterwards. Similarly, it is likely to believe that some HFC refrigerant will be returned through the KMO organization. (au) 11 refs., also published in Danish

  15. Hydrocarbons as Refrigerants―A Review

    Directory of Open Access Journals (Sweden)

    J. H. KOH

    2017-08-01

    Full Text Available Refrigerants used in air conditioning and refrigeration (AC&R indusries have come full circle since the beginning of the industrialrevolution. With concern on issues relating to the environment such as the global warming and climate change issues, we should finda better alternative than to continue using these refrigerants that cause global warming and ozone depletion. AC&R industryplayers have blended in by introducing some new equipment and components that are specificallydesigned for hydrocarbon (HC use. Mostnew refrigerators sold in Malaysia are already equipped with isobutane [a hydrocarbon designated as R-600a by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE standards]as refrigerants. Malaysia has ratifiedthe Montreal Protocol and targetted a 10% reduction in hydrochlorofluorocarbon(HCFC consumption, beginning 2016 with the banning of 2.5 horsepower (hp and below in air-conditioning (AC equipment to be used. Instead,hydrofluorocarbon(HFC R-410a was introduced as a replacement for HCFC- 22, whereas in other countries this HFC has been phased down. This article was initiated  because of the difficultin findinga replacement for HCFC. Also, the possibilities of using HC as an alternative to replace HCFC insteadof using HFC as a transitional refrigerant in place of HCFC is reviewed in this article. The performance of HC is very similar to HCFC and flmmability issues could be easily overcome with the use of an effectivedesign. Their use could be facilitated with the adaptation of specific standards and properly enacted legislatio

  16. Haptic-Multimodal Flight Control System Update

    Science.gov (United States)

    Goodrich, Kenneth H.; Schutte, Paul C.; Williams, Ralph A.

    2011-01-01

    The rapidly advancing capabilities of autonomous aircraft suggest a future where many of the responsibilities of today s pilot transition to the vehicle, transforming the pilot s job into something akin to driving a car or simply being a passenger. Notionally, this transition will reduce the specialized skills, training, and attention required of the human user while improving safety and performance. However, our experience with highly automated aircraft highlights many challenges to this transition including: lack of automation resilience; adverse human-automation interaction under stress; and the difficulty of developing certification standards and methods of compliance for complex systems performing critical functions traditionally performed by the pilot (e.g., sense and avoid vs. see and avoid). Recognizing these opportunities and realities, researchers at NASA Langley are developing a haptic-multimodal flight control (HFC) system concept that can serve as a bridge between today s state of the art aircraft that are highly automated but have little autonomy and can only be operated safely by highly trained experts (i.e., pilots) to a future in which non-experts (e.g., drivers) can safely and reliably use autonomous aircraft to perform a variety of missions. This paper reviews the motivation and theoretical basis of the HFC system, describes its current state of development, and presents results from two pilot-in-the-loop simulation studies. These preliminary studies suggest the HFC reshapes human-automation interaction in a way well-suited to revolutionary ease-of-use.

  17. High-global warming potential F-gas emissions in California: comparison of ambient-based versus inventory-based emission estimates, and implications of refined estimates.

    Science.gov (United States)

    Gallagher, Glenn; Zhan, Tao; Hsu, Ying-Kuang; Gupta, Pamela; Pederson, James; Croes, Bart; Blake, Donald R; Barletta, Barbara; Meinardi, Simone; Ashford, Paul; Vetter, Arnie; Saba, Sabine; Slim, Rayan; Palandre, Lionel; Clodic, Denis; Mathis, Pamela; Wagner, Mark; Forgie, Julia; Dwyer, Harry; Wolf, Katy

    2014-01-21

    To provide information for greenhouse gas reduction policies, the California Air Resources Board (CARB) inventories annual emissions of high-global-warming potential (GWP) fluorinated gases, the fastest growing sector of greenhouse gas (GHG) emissions globally. Baseline 2008 F-gas emissions estimates for selected chlorofluorocarbons (CFC-12), hydrochlorofluorocarbons (HCFC-22), and hydrofluorocarbons (HFC-134a) made with an inventory-based methodology were compared to emissions estimates made by ambient-based measurements. Significant discrepancies were found, with the inventory-based emissions methodology resulting in a systematic 42% under-estimation of CFC-12 emissions from older refrigeration equipment and older vehicles, and a systematic 114% overestimation of emissions for HFC-134a, a refrigerant substitute for phased-out CFCs. Initial, inventory-based estimates for all F-gas emissions had assumed that equipment is no longer in service once it reaches its average lifetime of use. Revised emission estimates using improved models for equipment age at end-of-life, inventories, and leak rates specific to California resulted in F-gas emissions estimates in closer agreement to ambient-based measurements. The discrepancies between inventory-based estimates and ambient-based measurements were reduced from -42% to -6% for CFC-12, and from +114% to +9% for HFC-134a.

  18. Emissions of halocarbons from mobile vehicle air conditioning system in Hong Kong.

    Science.gov (United States)

    Yan, H H; Guo, H; Ou, J M

    2014-08-15

    During the implementation of Montreal Protocol, emission inventories of halocarbons in different sectors at regional scale are fundamental to the formulation of relevant management strategy and inspection of the implementation efficiency. This study investigated the emission profile of halocarbons used in the mobile vehicle air conditioning system, the leading sector of refrigeration industry in terms of the refrigerant bank, market and emission, in the Hong Kong Special Administrative Region, using a bottom-up approach developed by 2006 IPCC Good Practice Guidance. The results showed that emissions of CFC-12 peaked at 53 tons ODP (Ozone Depletion Potential) in 1992 and then gradually diminished, whereas HFC-134a presented an increasing emission trend since 1990s and the emissions of HFC-134a reached 65,000 tons CO2-equivelant (CO2-eq) by the end of 2011. Uncertainty analysis revealed relatively high levels of uncertainties for special-purpose vehicles and government vehicles. Moreover, greenhouse gas (GHG) abatements under different scenarios indicated that potential emission reduction of HFC-134a ranged from 4.1 to 8.4 × 10(5)tons CO2-eq. The findings in this study advance our knowledge of halocarbon emissions from mobile vehicle air conditioning system in Hong Kong. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Techno-economic feasibility analysis of hydrogen fuel cell and solar photovoltaic hybrid renewable energy system for academic research building

    International Nuclear Information System (INIS)

    Singh, Anand; Baredar, Prashant; Gupta, Bhupendra

    2017-01-01

    Highlights: • A HFC and SPV HRES for stand-alone applications is proposed. • The FC program computes the optimum cost of HRES components. • HOMER pro software to calculate the optimum performance of HRES. - Abstract: A hydrogen fuel cell (HFC) and solar photovoltaic (SPV) hybrid renewable energy system (HRES) for stand-alone applications is proposed. This system arrangement of a hydrogen tank, battery, and an electrolyzer are used as like the energy storage. The economic viability of using HRES power to supply the electrical load demand of academic research building located at 23°12′N latitude and 77°24′E longitudes, India is examined. The fuzzy logic program computes the optimum value of capital and replacement cost of the components, which is then utilized in HOMER pro software to calculate the optimum performance of HRES. The results shows the HFC and battery bank are the most significant modules of the HRES to meet load demand at late night and early morning hours. The AC primary load consuming 20712.63 kWh/year out of total power generation of HRES which is 24570.72 kWh/year. The excess of electricity produced by HRES is 791.7709 kWh/year with the optimized cost of energy, unmet electrical load and capacity shortage of 0%.

  20. Biological monitoring the exposure to polycyclic aromatic hydrocarbons of coke oven workers in relation to smoking and genetic polymorphisms for GSTM1 and GSTT1

    Energy Technology Data Exchange (ETDEWEB)

    Joost H.M. van Delft; Marie-Jose S.T. Steenwinkel; Jeff G. van Asten; Nico de Vogel; Truus C.D.M. Bruijntjes-Rozier; Ton Schouten; Patricia Cramers; Lou Maas; Marcel H. van Herwijnen; Frederik-Jan van Schooten; Piet M.J. Hopmans [TNO Nutrition and Food Research Institute (Netherlands). Toxicology Division

    2001-07-01

    Occupational exposure to polycyclic aromatic hydrocarbons (PAH) increases the risk of developing lung cancer. Human exposure is often demonstrated by increased internal levels of PAH metabolites and of markers for early biological effects, like DNA adducts and cytogenetic aberrations. This study aimed to assess whether the current exposure to PAH of coke oven workers in a Dutch plant induced biological effects, and to determine if these effects are influenced by tobacco smoking and by genetic polymorphisms for the glutathione S-transferase genes GSTM1 and GSTT1. Urinary 1-hydroxypyrene (1-OHpyr) levels were used to monitor the internal dose, while the internal effective dose was assessed by monitoring PAH-DNA adducts, DNA strand breaks (Comet assay), sister-chromatid exchanges (SCE) and cells with a high frequency of SCE (HFC) in lymphocytes together with micronuclei (MN) in exfoliated urothelial cells. Occupational exposure to PAH resulted in statistically significant increased 1-OHpyr levels, but it did not cause a significant induction of SCE, HFC, MN, DNA strand breaks or DNA adducts. Smoking caused a significant increase of 1-OHpyr, SCE, HFC and DNA adducts, but not of MN or DNA strand breaks. Following correction for the smoking-related effects, no occupational induction of the effect biomarkers could be discerned. Multi-variate analysis did not show a significant influence of GSTM1 and GSTT1 polymorphisms on any biomarker. Also no significant interactions were observed between the various biomarkers.

  1. Complexon Solutions in Freon for Decontamination of Solids and SNF Treatment

    International Nuclear Information System (INIS)

    Kamachev, V.; Shadrin, A.; Murzin, A.

    2008-01-01

    Full text of publication follows: The possibility of using complexon solutions in supercritical and compressed carbon dioxide for decontamination of solid surfaces and for spent nuclear fuel (SNF) treatment was demonstrated in the works of Japanese, Russian and American researchers. The obtained data showed that the use of complexon solutions in carbon dioxide sharply decreases the volume of secondary radioactive wastes because it can be easily evaporated, purified and recycled. Moreover, high penetrability of carbon dioxide allows decontamination of surfaces with complex shape. However, one of the disadvantages of carbon dioxide is its high working pressure (10-20 MPa for supercritical CO 2 and 7 MPa for compressed CO 2 ). Moreover, in case of SNF treatment, carbon dioxide solvent will be contaminated with 14 C, which in the course of SNF dissolution in CO 2 containing TBP*HNO 3 adduct stage will be oxidized into CO 2 . These main disadvantages can be eliminated by using complexon solutions in ozone-friendly Freon HFC-134a for decontamination and SNF treatment. Our experimental data for real contaminated materials showed that the decontamination factor for complexon solutions in liquid Freon HFC-134a at 1,2 MPa and 25 deg. C is close to that attained in carbon dioxide. Moreover, the possibility of SNF treatment in Freon HFC-134a was demonstrated in trials using real SNF and its imitators. (authors)

  2. Characterization of RPC operation with new environmental friendly mixtures for LHC application and beyond

    International Nuclear Information System (INIS)

    Guida, R.; Capeans, M.; Mandelli, B.

    2016-01-01

    The large muon trigger systems based on Resistive Plate Chambers (RPC) at the LHC experiments are currently operated with R134a based mixture. Unfortunately R134a is considered a greenhouse gas with high impact on the enviroment and therefore will be subject to regulations aiming in strongly reducing the available quantity on the market. The immediat effects might be instability on the price and incertitude in the product availability. Alternative gases (HFO-1234yf and HFO-1234ze) have been already identified by industry for specific applications as replacement of R134a. Moreover, HFCs similar to the R134a but with lower global warming potential (GWP) are already available (HFC-245fa, HFC-32, HFC-152a). The present contribution describes the results obtained with RPCs operated with new enviromemtal friendly gases. A particular attention has been addressed to the possibility of maintening the current operation conditions (i.e. currently used applied voltage and front-end electronics) in order to be able to use a new mixture for RPC systems even where the common infrastructure (i.e. high voltage and detector components) cannot be replaced for operation at higher applied voltages.

  3. Medium-chain triglyceride ameliorates insulin resistance and inflammation in high fat diet-induced obese mice.

    Science.gov (United States)

    Geng, Shanshan; Zhu, Weiwei; Xie, Chunfeng; Li, Xiaoting; Wu, Jieshu; Liang, Zhaofeng; Xie, Wei; Zhu, Jianyun; Huang, Cong; Zhu, Mingming; Wu, Rui; Zhong, Caiyun

    2016-04-01

    The aim of the present study was to investigate the in vivo effects of dietary medium-chain triglyceride (MCT) on inflammation and insulin resistance as well as the underlying potential molecular mechanisms in high fat diet-induced obese mice. Male C57BL/6J mice (n = 24) were fed one of the following three diets for a period of 12 weeks: (1) a modified AIN-76 diet with 5 % corn oil (normal diet); (2) a high-fat control diet (17 % w/w lard and 3 % w/w corn oil, HFC); (3) an isocaloric high-fat diet supplemented with MCT (17 % w/w MCT and 3 % w/w corn oil, HF-MCT). Glucose metabolism was evaluated by fasting blood glucose levels and intraperitoneal glucose tolerance test. Insulin sensitivity was evaluated by fasting serum insulin levels and the index of homeostasis model assessment-insulin resistance. The levels of serum interleukin-6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-α were measured by ELISA, and hepatic activation of nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPK) pathways was determined using western blot analysis. Compared to HFC diet, consumption of HF-MCT did not induce body weight gain and white adipose tissue accumulation in mice. HFC-induced increases in serum fasting glucose and insulin levels as well as glucose intolerance were prevented by HF-MCT diet. Meanwhile, HF-MCT resulted in significantly lower serum IL-6 level and higher IL-10 level, and lower expression levels of inducible nitric oxide synthase and cyclooxygenase-2 protein in liver tissues when compared to HFC. In addition, HF-MCT attenuated HFC-triggered hepatic activation of NF-κB and p38 MAPK. Our study demonstrated that MCT was efficacious in suppressing body fat accumulation, insulin resistance, inflammatory response, and NF-κB and p38 MAPK activation in high fat diet-fed mice. These data suggest that MCT may exert beneficial effects against high fat diet-induced insulin resistance and inflammation.

  4. Modulation of lung inflammation by vessel dilator in a mouse model of allergic asthma

    Directory of Open Access Journals (Sweden)

    Cormier Stephania A

    2009-07-01

    Full Text Available Abstract Background Atrial natriuretic peptide (ANP and its receptor, NPRA, have been extensively studied in terms of cardiovascular effects. We have found that the ANP-NPRA signaling pathway is also involved in airway allergic inflammation and asthma. ANP, a C-terminal peptide (amino acid 99–126 of pro-atrial natriuretic factor (proANF and a recombinant peptide, NP73-102 (amino acid 73–102 of proANF have been reported to induce bronchoprotective effects in a mouse model of allergic asthma. In this report, we evaluated the effects of vessel dilator (VD, another N-terminal natriuretic peptide covering amino acids 31–67 of proANF, on acute lung inflammation in a mouse model of allergic asthma. Methods A549 cells were transfected with pVD or the pVAX1 control plasmid and cells were collected 24 hrs after transfection to analyze the effect of VD on inactivation of the extracellular-signal regulated receptor kinase (ERK1/2 through western blot. Luciferase assay, western blot and RT-PCR were also performed to analyze the effect of VD on NPRA expression. For determination of VD's attenuation of lung inflammation, BALB/c mice were sensitized and challenged with ovalbumin and then treated intranasally with chitosan nanoparticles containing pVD. Parameters of airway inflammation, such as airway hyperreactivity, proinflammatory cytokine levels, eosinophil recruitment and lung histopathology were compared with control mice receiving nanoparticles containing pVAX1 control plasmid. Results pVD nanoparticles inactivated ERK1/2 and downregulated NPRA expression in vitro, and intranasal treatment with pVD nanoparticles protected mice from airway inflammation. Conclusion VD's modulation of airway inflammation may result from its inactivation of ERK1/2 and downregulation of NPRA expression. Chitosan nanoparticles containing pVD may be therapeutically effective in preventing allergic airway inflammation.

  5. Multiple amino acid sequence alignment nitrogenase component 1: insights into phylogenetics and structure-function relationships.

    Directory of Open Access Journals (Sweden)

    James B Howard

    Full Text Available Amino acid residues critical for a protein's structure-function are retained by natural selection and these residues are identified by the level of variance in co-aligned homologous protein sequences. The relevant residues in the nitrogen fixation Component 1 α- and β-subunits were identified by the alignment of 95 protein sequences. Proteins were included from species encompassing multiple microbial phyla and diverse ecological niches as well as the nitrogen fixation genotypes, anf, nif, and vnf, which encode proteins associated with cofactors differing at one metal site. After adjusting for differences in sequence length, insertions, and deletions, the remaining >85% of the sequence co-aligned the subunits from the three genotypes. Six Groups, designated Anf, Vnf , and Nif I-IV, were assigned based upon genetic origin, sequence adjustments, and conserved residues. Both subunits subdivided into the same groups. Invariant and single variant residues were identified and were defined as "core" for nitrogenase function. Three species in Group Nif-III, Candidatus Desulforudis audaxviator, Desulfotomaculum kuznetsovii, and Thermodesulfatator indicus, were found to have a seleno-cysteine that replaces one cysteinyl ligand of the 8Fe:7S, P-cluster. Subsets of invariant residues, limited to individual groups, were identified; these unique residues help identify the gene of origin (anf, nif, or vnf yet should not be considered diagnostic of the metal content of associated cofactors. Fourteen of the 19 residues that compose the cofactor pocket are invariant or single variant; the other five residues are highly variable but do not correlate with the putative metal content of the cofactor. The variable residues are clustered on one side of the cofactor, away from other functional centers in the three dimensional structure. Many of the invariant and single variant residues were not previously recognized as potentially critical and their identification

  6. Analyzing components of Community Reinforcement and Family Training (CRAFT): Is treatment entry training sufficient?

    Science.gov (United States)

    Kirby, Kimberly C; Benishek, Lois A; Kerwin, MaryLouise E; Dugosh, Karen L; Carpenedo, Carolyn M; Bresani, Elena; Haugh, James A; Washio, Yukiko; Meyers, Robert J

    2017-11-01

    Community Reinforcement and Family Training (CRAFT) assists family members with a treatment-resistant loved one. The most consistent outcome of CRAFT is increased treatment entry of the identified treatment-resistant person (IP). This led us to question whether all 6 components of CRAFT are necessary. In a randomized clinical trial, 115 concerned significant others (CSOs) of an IP received 12-14 sessions of the full CRAFT intervention, 4-6 sessions focused on Treatment Entry Training (TEnT), or 12-14 sessions of Al-Anon/Nar-Anon Facilitation (ANF). We monitored treatment entry, attendance, and substance use of the IP and the CSO's mood and functioning. Data were collected at baseline and 4, 6, and 9 months after the baseline. We found significant reductions in time to treatment entry (χ(2)2 = 8.89, p = .01) and greater treatment entry rates for CRAFT (62%; odds ratio [OR] = 2.7, 95% confidence interval [CI] = 1.1-6.9) and TEnT (63%; OR = 2.9, 95% CI = 1.2-7.5) compared with ANF (37%), but CRAFT and TEnT did not differ significantly from each other (OR = 1.1, 95% CI = 0.4-2.7). No between-group differences in IP drug use were reported by CSOs, but days of drug use decreased over time for all groups (F(3, 277) = 13.47, p CRAFT produces greater treatment entry rates than ANF and found similar treatment entry rates for CRAFT and TEnT. This suggests that treatment entry training is sufficient for producing the best established outcome of CRAFT. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  7. Relationship between natriuretic peptides and inflammation: proteomic evidence obtained during acute cellular cardiac allograft rejection in humans.

    Science.gov (United States)

    Meirovich, Yael F; Veinot, John P; de Bold, Mercedes L Kuroski; Haddad, Haissam; Davies, Ross A; Masters, Roy G; Hendry, Paul J; de Bold, Adolfo J

    2008-01-01

    Cardiac natriuretic peptides (NPs) atrial natriuretic factor (ANF) and brain natriuretic peptide (BNP) are polypeptide hormones secreted by the heart. Previously, we found that BNP, but not ANF, plasma levels may increase during an acute cellular cardiac allograft rejection episode. In vitro, the pro-inflammatory cytokines interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) produced a selective increase of BNP gene expression and secretion. Other pro-inflammatory cytokines had no such effects. We identified cytokines associated with the selective upregulation of BNP during cardiac allograft rejection using a proteomics approach to measure 120 cytokines and related substances in the plasma of 16 transplant patients before, during and after an acute rejection episode. The values obtained were correlated with BNP plasma levels. Cytokines identified as being significantly related to BNP plasma levels were tested in neonatal rat ventricular cardiocytes in culture for their ability to selectively promote BNP secretion. The signaling pathway related to this phenomenon was pharmacologically characterized. Regulated-on-activation, normal T-expressed and secreted (RANTES), neutrophil-activating protein-2 (NAP-2) and insulin growth factor binding protein-1 (IGFBP-1) had significant correlations with BNP plasma levels during Grade 3A (Grade 2 revised [2R]) or above rejection as diagnosed by endomyocardial biopsy score according to the International Society for Heart and Lung Transplantation (ISHLT) grading system. In rat neonatal ventricular cardiocyte cultures, IGFBP-1 and RANTES were capable of promoting BNP, but not ANF secretion, as observed in rejecting patients. The BNP-promoting secretion activity of the identified cytokines was abolished by SB203580, a specific p38 MAP kinase inhibitor. This work shows that cytokines other than pro-inflammatory cytokines correlate with BNP plasma levels observed during acute cardiac allograft rejection, and that

  8. Neuronal specializations for the processing of interaural difference cues in the chick

    Directory of Open Access Journals (Sweden)

    Harunori eOhmori

    2014-05-01

    Full Text Available Sound information is encoded as a series of spikes of the auditory nerve fibers (ANFs, and then transmitted to the brainstem auditory nuclei. Features such as timing and level are extracted from ANFs activity and further processed as the interaural time difference (ITD and the interaural level difference (ILD, respectively. These two interaural difference cues are used for sound source localization by behaving animals. Both cues depend on the head size of animals and are extremely small, requiring specialized neural properties in order to process these cues with precision. Moreover, the sound level and timing cues are not processed independently from one another. Neurons in the nucleus angularis (NA are specialized for coding sound level information in birds and the ILD is processed in the posterior part of the dorsal lateral lemniscus nucleus (LLDp. Processing of ILD is affected by the phase difference of binaural sound. Temporal features of sound are encoded in the pathway starting in nucleus magnocellularis (NM, and ITD is processed in the nucleus laminaris (NL. In this pathway a variety of specializations are found in synapse morphology, neuronal excitability, distribution of ion channels and receptors along the tonotopic axis, which reduces spike timing fluctuation in the ANFs-NM synapse, and imparts precise and stable ITD processing to the NL. Moreover, the contrast of ITD processing in NL is enhanced over a wide range of sound level through the activity of GABAergic inhibitory systems from both the superior olivary nucleus (SON and local inhibitory neurons that follow monosynaptic to NM activity.

  9. Web-based Data Mining to Systematically Determine Data Quality From the EarthScope USArray Seismic Observatory Project

    Science.gov (United States)

    Newman, R. L.; Lindquist, K. G.; Hansen, T. S.; Vernon, F. L.; Eakins, J.; Foley, S.

    2004-12-01

    When fully operational, the Transportable Array (TA) and Flexible Array (FA) components of the continent-scale EarthScope USArray seismic observatory project will provide telemetered real-time data from up to 600 stations. By the fifth year of the deployment the predicted total amount of data production for the TA and FA will be approximately 1500 Gb/yr and approximately 1000 Gb/yr respectively. In addition to delivering the data to the IRIS Data Management Center (DMC) for permanent archiving, the Array Network Facility (ANF) is charged with real-time data quality control, calibration, metadata storage and retrieval, network monitoring and local archiving. The Antelope real-time processing software provides the back-bone to this effort, supported by the Storage Resource Broker data replication/archiving system and the Nagios network monitoring tool. Real-time, web-based data mining, with support for multiple database schemas, is provided by an Antelope interface to both Perl and PHP scripting languages. This allows embedding of database functions in HTML. A suite of online tools allows query and graphical display of dynamic real-time sensor network parameters such as data latency, network topologies, and data return rates. Data and metadata are also web-accessible, for example XML trees of seismic data and graphical display of instrument response functions. The purpose of these tools is to provide the ANF, IRIS and end-users of USArray data with a real-time systematic method of determining data quality for the spatio-temporal area of interest. The tools are accessible at http://anf.ucsd.edu

  10. Characterization and distribution of receptors for the atrial natriuretic peptides in mammalian brain

    International Nuclear Information System (INIS)

    Quirion, R.; Dalpe, M.; Dam, T.V.

    1986-01-01

    Both rat 125 I-labeled atrial natriuretic polypeptide [ 125 I-ANP or atrial natriuretic factor fragment ANF-(99-126)] and human 125 I-α-ANP or human ANF-(99-126)] bind with high specificity and affinity to an apparent single class of sites in guinea pig brain. Similar results have been reported in peripheral tissues, which indicate that central and peripheral ANP binding sites have fairly similar structural requirements. In vitro receptor autoradiography shows that in the guinea pig brain, 125 I-ANP binding sites are highly concentrated in the external plexiform layer of the olfactory bulb, subfornical organ, various thalamic nuclei, medial geniculate nucleus, and cerebellum. Lower densities are found in the central nucleus of the amygdala, dentate gyrus, hippocampus, and area postrema. Most remaining regions contain much lower densities of sites. In rat brain 125 I-ANP binding sites are differentially distributed, with high densities in the subfornical organ, area postrema, and linings of ventricles but low densities in the thalamus and cerebellum. In monkey brain, 125 I-ANP binding sites are concentrated in the cerebellum. The presence of high densities of 125 I-ANP binding sites in various brain regions strongly suggests the existence of a family of brain-heart peptides, in analogy to the well-known brain-gut peptides. Moreover, the extensive distribution of 125 I-ANP binding sites in mammalian brain suggests that the possible roles of ANP/ANF-like peptides in brain are not restricted to the central regulation of cardiovascular parameters

  11. Non-Monotonic Relation Between Noise Exposure Severity and Neuronal Hyperactivity in the Auditory Midbrain

    Directory of Open Access Journals (Sweden)

    Lara Li Hesse

    2016-08-01

    Full Text Available The occurrence of tinnitus can be linked to hearing loss in the majority of cases, but there is nevertheless a large degree of unexplained heterogeneity in the relation between hearing loss and tinnitus. Part of the problem might be that hearing loss is usually quantified in terms of increased hearing thresholds, which only provides limited information about the underlying cochlear damage. Moreover, noise exposure that does not cause hearing threshold loss can still lead to hidden hearing loss (HHL, i.e. functional deafferentation of auditory nerve fibres (ANFs through loss of synaptic ribbons in inner hair cells. Whilst it is known that increased hearing thresholds can trigger increases in spontaneous neural activity in the central auditory system, i.e. a putative neural correlate of tinnitus, the central effects of HHL have not yet been investigated. Here, we exposed mice to octave-band noise at 100 and 105 dB SPL, to generate HHL and permanent increases of hearing thresholds, respectively. Deafferentation of ANFs was confirmed through measurement of auditory brainstem responses and cochlear immunohistochemistry. Acute extracellular recordings from the auditory midbrain (inferior colliculus demonstrated increases in spontaneous neuronal activity (a putative neural correlate of tinnitus in both groups. Surprisingly the increase in spontaneous activity was most pronounced in the mice with HHL, suggesting that the relation between hearing loss and neuronal hyperactivity might be more complex than currently understood. Our computational model indicated that these differences in neuronal hyperactivity could arise from different degrees of deafferentation of low-threshold ANFs in the two exposure groups.Our results demonstrate that HHL is sufficient to induce changes in central auditory processing, and they also indicate a non-monotonic relationship between cochlear damage and neuronal hyperactivity, suggesting an explanation for why tinnitus might

  12. A combination of preliminary results on gauge boson couplings measured by the LEP Experiments

    CERN Document Server

    CERN. Geneva

    2004-01-01

    This note presents a combination of published and preliminary measurements of triple gauge boson couplings (TGCs) and quartic gauge boson couplings (QGCs) from the four LEP experiments. We give an updated combination of the charged TGCs, g1z, kg and lg in single and multi-parameter fits. Updated results from the QGCs from the ZZgg vertex, ac/Lambda^2 and a0/Lambda^2, are given as well. The combinations of neutral TGCs hiv anf fiv are also presented, including an updated fiv combination.

  13. Was sind eigentlich Daten?

    Directory of Open Access Journals (Sweden)

    Jakob Voß

    2013-10-01

    Full Text Available Daten und ihre Nutzung als Linked Data, Big Data, Forschungsdaten, etc. erfahren aktuell verstärkte Aufmerksamkeit. Bei genauerer Betrachtung lässt sich dieses Interesse bis zu den Anfängen der Computernutzung zurückverfolgen, jedoch ohne dass ein eigenständiges, theoretisches Konzept von ‘Daten’ erkennbar wäre. Der folgende Beitrag gibt eine kurze Einführung in verschiedene Datenbegriffe aus philosophischer Sicht und verbindet diese mit dem Konzept des Dokuments in der Bibliotheks- und Informationswissenschaft.

  14. Die Grundlagen der Fernsehtechnik: Systemtheorie und Technik der Bildübertragung

    Science.gov (United States)

    Mahler, Gerhard

    Umfassende Einführung in die Grundlagen der Bewegtbild-Übertragung von den Anfängen bis zum heutigen Stand des digitalen Fernsehens mit einer aus der Praxis entstandenen systemtheoretischen Analyse. Die kompakte und anschaulich bebilderte Darstellung mit elementaren mathematischen Beschreibungen macht es dem Leser leicht, sich in die Bildübertragungstechnik einzuarbeiten. Thematische Einheiten erweitern den Wissensstoff - u.a. zu den Themen visuelle Wahrnehmung, mehrdimensionale Signaldarstellung, Farbmetrik, Digitalisierung, Elektronenoptik - und zeigen deren Anwendung auf die elektronische Bildübertragung.

  15. Perbaikan Teknologi Beternak Kambing di Desa Dhampulo Kabupaten Aceh Besar

    Directory of Open Access Journals (Sweden)

    Mawardi Mohd. Ali

    2001-10-01

    Full Text Available ABSTRACT A study on the correction of breeding goat technology in Dhampulo village was conducted from July 1996 to Desember 1997. Twenty Kacang goats divided into to groups. Each groub cossed with one FE male anf another groub crossed with Kacang Male. Reproduction and production performance of kid at both group was compared. The resilt of this study showed that group of PE male was better. Kid crop was 160 vs 120%, birth type was 60 vs 30%, birth weigt was 1.61 vs 1.33 kg and weight at one month age was 3.44 vs 2.72 kg.

  16. Tunneling spectroscopy on grain boundary junctions in electron-doped high-temperature superconductors

    International Nuclear Information System (INIS)

    Welter, B.

    2007-01-01

    Some methods are developed anf presented, by means of which from experimental tunnel spectra, especially on symmetric SIS contacts, informations about the properties of electrodes and tunnel barriers can be obtained. Especially a procedure for the numerical unfolding of symmetric SIS spectra is proposed. Furthermore a series of models is summarized, which can explain the linear background conductivity observed in many spectra on high-temperature superconductors. The results of resistance measurements on film bridges are presented. Especially different methods for the determination of H c2 (T) respectively H c2 (0) are presented and applied to the experimental data. Finally the results of the tunnel-spectroscopy measurements are shown

  17. Herpetofauna em um fragmento de Floresta Atlântica no Estado da Paraíba, Região Nordeste do Brasil

    OpenAIRE

    Gindomar Gomes Santana; Washington L. S. Vieira; Gentil A. Pereira-Filho; Fagner R. Delfim; Yuri C. Lima; Kleber S. Vieira

    2008-01-01

    http://dx.doi.org/10.5007/2175-7925.2008v21n1p75A herpetofauna de um fragmento urbano de Floresta Atlântica foi estudada quanto à riqueza de espéciese à utilização do habitat. A coleta de espécimes  foi realizada através de procura visual limitada por tempo e armadilhas de interceptação e queda. Foram registradas quatorze espécies de anfíbios anuros pertencentes às famílias Bufonidae, Brachycephalidae, Hylidae, Leptodactylidae, Leiuperidae, Microhylidae e Ranidae. Os répteis foram representad...

  18. A cryptic Early Palaeozoic event in the Nacea Antiform? 40Ar/39Ar amphibole data in the Puente de Selce granitoid

    OpenAIRE

    Gutiérrez Alonso, Gabriel; Fernández Suárez, Javier; Ortega Rivera, M. A.; Lee, J. k. W.; Murphy, J. B.

    2005-01-01

    Las edades 40Ar/39Ar obtenidas a partir de anfíboles del granitoide Neoproterozoico de Puente de Selce, localizado en el Antiforme del Narcea junto con la existencia de fábricas de deformación relictas generadas en condiciones de media-alta temperatura en las mismas rocas puede ser interpretada como debida a un evento críptico de edad Paleozoico Inferior fuertemente retrabajado durante la deformación varisca. La naturaleza y la cinemática de este posible evento no pueden precisarse pero si se...

  19. A cryptic Early Palaeozoic event in the Narcea Antiform? 40Ar/39Ar amphibole data in the Puente de Selce granitoid

    OpenAIRE

    Gutiérrez Alonso, Gabriel; Fernández Suárez, J.; Keppie, J. D.; Ortega Rivera, M. A.; Lee, J. K. W.; Murphy, J. B.

    2005-01-01

    Las edades 40Ar/39Ar obtenidas a partir de anfíboles del granitoide Neoproterozoico de Puente de Selce, localizado en el Antiforme del Narcea junto con la existencia de fábricas de deformación relictas generadas en condiciones de media-alta temperatura en las mismas rocas puede ser interpretada como debida a un evento críptico de edad Paleozoico Inferior fuertemente retrabajado durante la deformación varisca. La naturaleza y la cinemática de este posible evento no pueden precisars...

  20. Hábitos alimentarios e interacciones tróficas de Anisotremus interruptus (Pisces: Haemulidae) y Lutjanus argentiventris (Pisces: Lutjanidae) en el Pacífico Central Mexicano

    OpenAIRE

    Flores-Ortega,Juan R; Avila-Castro,Elizabeth; Haro-Preciado,Hugo J; Godínez-Domínguez,Enrique

    2014-01-01

    Se obtuvieron estómagos de ejemplares adultos de Anisotremus interruptus y Lutjanus argentiventris para conocer los componentes alimentarios de cada especie y sus interacciones tróficas durante un periodo de surgencia en el Pacífico Central Mexicano. Se identificaron 79 tipos de presas agrupadas en 15 categorías alimentarias. La dieta de A. interruptus está constituida principalmente de microinvertebrados (anfípodos y larvas de crustáceos), holotúridos y ofiuros. L. argentiventris se alimenta...

  1. La fábrica del olivino y las condiciones de la deformación de las rocas ultramáficas del Macizo de Herbeira (Cabo Ortegal, NO del Macizo Iberico)

    OpenAIRE

    García Izquierdo, Beatriz; Capote, Ramón; Lunar, Rosario

    2011-01-01

    [ES] En el Macizo de Herbeira, situado en el Complejo varisco de Cabo Ortegal (NO del Macizo Ibérico), forma parte de una lámina de cabalgamiento constituida por rocas ultramáficas que han sufrido una compleja historia de deformación. La falla de Trans Herbeira (FTH), divide el macizo en dos sectores diferentes. El sector oriental está formado mayoritariamente por harzburgitas ricas en anfíbol, mientras que el sector occidental es litológicamente más variado, con una sucesión de h...

  2. La fábrica del olivino y las condiciones de la deformación de las rocas ultramáficas del Macizo de Herbeira (Cabo Ortegal, NO del Macizo Ibérico)

    OpenAIRE

    García Izquierdo,, Beatriz; Capote del Villar, Ramón; Lunar Hernández, Rosario

    2011-01-01

    En el Macizo de Herbeira, situado en el Complejo varisco de Cabo Ortegal (NO del Macizo Ibérico), forma parte de una lámina de cabalgamiento constituida por rocas ultramáficas que han sufrido una compleja historia de deformación. La falla de Trans Herbeira (FTH), divide el macizo en dos sectores diferentes. El sector oriental está formado mayoritariamente por harzburgitas ricas en anfíbol, mientras que el sector occidental es litológicamente más variado, con una sucesión de harzburgita basa...

  3. Atrium and HTP fuel elements for the U.S. market

    International Nuclear Information System (INIS)

    Morgan, J.N.; Krebs, W.D.

    1994-01-01

    The international acitivities of Siemens in the nuclear fuel sector are the responsibility of the Nuclear Fuel Cycle Unit of the Power Generation Division (KWU) in Germany, the Nuclear Dividion of Siemens Power Corporation (SPC) in the Unites States, and the German Siemens subsidiaries, ANF GmbH (fuel element fabrication) in Lingen and NRG - Nuklearrohr Gesellschaft mbH (cladding tube production) in Duisburg. The requirements of the U.S. market for light water reactor fuel elements are met by products from the European market. (orig.) [de

  4. Kaleidoscope modes in large aperture Porro prism resonators

    CSIR Research Space (South Africa)

    Burger, L

    2008-08-01

    Full Text Available G == (3) and L aNF λ 2 = . (4) 0 20 40 60 80 100 120 140 160 180 200 0 10 20 30 40 50 60 70 80 90 Porro Angle cancer (degrees) N u m be r o f p et a ls N... ultimately results in the convergence of all starting fields to the petal–like patterns, as shown in Fig. 6 (see also Fig. 3 ‘large aperture mode’ movie). In the presence of gain and hence a limited build–up time, such a convergence would not necessarily...

  5. Chronotoxicity of contaminants (etanol and hezvy metales) in a freshwater teleost Dario rerio (Hamilton, 1882) and marine amphipods Gammarus aequicauda (Martynov, 1931) and Gammarus chevreuxi (Sexton, 1913) = Cronotixicidad de contaminantes (etanol y metales pesados) en el teleósteo de agua dulce Dario rerio (Hamilton, 1822) y los antípodos marinos, Gammarus aequicauda (Martynov, 1931) y Gammarus chevreuxi (Sexton, 1913)

    OpenAIRE

    Bello Marín, Carolina

    2015-01-01

    Esta tesis tiene como objetivo investigar los efectos del etanol y metales pesados (cadmio y mercurio) en los patrones diarios de dos especies acuáticas clave: pez cebra (Darío rerio) y anfípodo gammarus (G. aequicauda y G. chevreuxi). La investigación se realizó en dos niveles organizativos: comportamental y molecular. Con este fin, hemos establecido cuatro objetivos específicos: 1. Investigar los efectos al etanol en el pez cebra en función en su ritmo circadiano. 2. Determinar la exi...

  6. Laboratory experiments examining inducible defense show variable responses of temperate brown and red macroalgae Experimentos de laboratorio para examinar las defensas inducibles muestran respuestas variables en macroalgas pardas y rojas de ambientes templados

    Directory of Open Access Journals (Sweden)

    EVA ROTHÄUSLER

    2005-12-01

    Full Text Available Macroalgae can defend themselves against generalist and specialist herbivores via morphological and/or chemical traits. Herein we examined the defensive responses (via relative palatability of two brown (Lessonia nigrescens, Glossophora kunthii and two red algae (Grateloupia doryphora, Chondracanthus chamissoi from the northern-central coast of Chile against selected generalist meso-herbivores. Two laboratory experiments were conducted to investigate whether (i algae can respond generally to grazing pressure of meso-herbivores (amphipods, isopods and juvenile sea urchins and whether (ii these algal responses were inducible. In order to examine palatability and thus effectiveness of responses, feeding assays were run after each experiment using fresh algal pieces and artificial agar-based food. Lessonia nigrescens responded to amphipods but not to sea urchins, and G. kunthii showed inducible response against one species of amphipods. Grateloupia doryphora did not respond against any of the tested grazers, whereas C. chamissoi responded against one species of amphipods and the tested isopod. Our results indicate variable responses of macroalgae against selected generalist meso-herbivores and evidence of an inducible defense in the brown alga G. kunthii.Muchas macroalgas poseen la capacidad de defenderse contra herbívoros generalistas y especialistas utilizando defensas químicas y/o morfológicas. En este trabajo se examinó la respuesta de la palatabilidad ante meso-herbívoros generalistas de dos algas pardas (Lessonia nigrescens, Glossophora kunthii y dos algas rojas (Grateloupia doryphora, Chondracanthus chamissoi de la costa Norte de Chile. Se realizaron dos experimentos de laboratorio para investigar si: (i las algas pueden responder al pastoreo realizado por meso-herbivoros generalistas (anfípodos, isópodos y erizos juveniles y (ii si la respuesta de estas algas es inducible. Para examinar la palatabilidad y de esta forma la efectividad

  7. Atrial natriuretic peptide and feeding activity patterns in rats

    Directory of Open Access Journals (Sweden)

    Oliveira M.H.A.

    1997-01-01

    Full Text Available This review presents historical data about atrial natriuretic peptide (ANP from its discovery as an atrial natriuretic factor (ANF to its role as an atrial natriuretic hormone (ANH. As a hormone, ANP can interact with the hypothalamic-pituitary-adrenal axis (HPA-A and is related to feeding activity patterns in the rat. Food restriction proved to be an interesting model to investigate this relationship. The role of ANP must be understood within a context of peripheral and central interactions involving different peptides and pathways

  8. Knock-limited performance of several internal coolants

    Science.gov (United States)

    Bellman, Donald R; Evvard, John C

    1945-01-01

    The effect of internal cooling on the knock-limited performance of an-f-28 fuel was investigated in a CFR engine, and the following internal coolants were used: (1) water, (2), methyl alcohol-water mixture, (3) ammonia-methyl alcohol-water mixture, (4) monomethylamine-water mixture, (5) dimethylamine-water mixture, and (6) trimethylamine-water mixture. Tests were run at inlet-air temperatures of 150 degrees and 250 degrees F. to indicate the temperature sensitivity of the internal-coolant solutions.

  9. From physics to metaphysics. Physical unification and string approach; Von der Physik zur Metaphysik. Physikalische Vereinheitlichung und Stringansatz

    Energy Technology Data Exchange (ETDEWEB)

    Hedrich, R.

    2007-07-01

    In spite the string approach as attempt of a nomologically unified comprehension of all interactions inclusively the gravitation exists already over three decades the physical principles on which it is based are yet completely unclear; and not the most unimportant empirically provable quantitative prediction exists. Without empirical data, which would be incompatible with the stablished theories - quantum-field theoretical standard model anf general relativity - only the conceptual incompatibility of both together with the unification idea yields a motivation for the string approach. By this however physics threatens to exceed under consequent continuation of their hitherto successful strategies the methodological framework of empirical sciences.

  10. SIMPUL-SIMPUL PENDIDIKAN DALAM SURAH AL ANFÂL DAN AL TAUBAH

    Directory of Open Access Journals (Sweden)

    Noorazmah Hidayati

    2013-10-01

    Full Text Available Today, concept of jihad disposed wrong to be understood. Jihad mean as a war, even must destroyed some people and creatures with in the name of Islam. As a consequence Islam refer to a terorist religion. This opinion must be corrected, because Islam is “rahmatan lil ‘alamiin”. In fact, in independent time jihad should be manifested to protect equitable and moral of humanbeing. This article describes some essences of education of jihad in surah al Anfâl and al Taubah with the result that every action will valued as jihad and humanbeing values will protected.

  11. Inactivation Methods of Trypsin Inhibitor in Legumes: A Review.

    Science.gov (United States)

    Avilés-Gaxiola, Sara; Chuck-Hernández, Cristina; Serna Saldívar, Sergio O

    2018-01-01

    Seed legumes have played a major role as a crop worldwide, being cultivated on about 12% to 15% of Earth's arable land; nevertheless, their use is limited by, among other things, the presence of several antinutritional factors (ANFs - naturally occurring metabolites that the plant produces to protect itself from pest attacks.) Trypsin inhibitors (TIs) are one of the most relevant ANFs because they reduce digestion and absorption of dietary proteins. Several methods have been developed in order to inactivate TIs, and of these, thermal treatments are the most commonly used. They cause loss of nutrients, affect functional properties, and require high amounts of energy. Given the above, new processes have emerged to improve the nutritional quality of legumes while trying to solve the problems caused by the use of thermal treatments. This review examines and discusses the methods developed by researchers to inactivate TI present in legumes and their effects over nutritional and functional properties. © 2017 Institute of Food Technologists®.

  12. Inclined-wall regular micro-pillar-arrayed surfaces covered entirely with an alumina nanowire forest and their improved superhydrophobicity

    International Nuclear Information System (INIS)

    Kim, Dae-Ho; Lee, Dongyun; Cho, Chae-Ryong; Kim, Soo-Hyung; Lee, Deug-Woo; Kim, Jong-Man; Kim, Yongsung; Kang, Jae-Wook; Hong, Suck Won

    2011-01-01

    This paper reports a multiple-scale hierarchically structured superhydrophobic surface that is composed of inclined-wall regular micro-pillar arrays covered entirely with an alumina nanowire forest (ANF) to improve the surface wettability. The multiple-scaled structures were fabricated stably using a simple batch process based on an anisotropic chemical silicon etching process and a subsequent time-controlled anodic aluminum oxide technique. The surface wetting properties of the mono-roughened surfaces with inclined-wall micro-pillar arrays, which are normally in the Wenzel wetting regime, could be transitioned perfectly to the slippery Cassie mode and enhanced greatly in the Wenzel regime in cases of a high- and low-density of the micro-pillars, respectively, by easily amplifying the intrinsic contact angle through the entire coverage of the ANF on the micro-roughened surfaces. The wettability of the proposed multiple-scaled surfaces could also be predicted using analytic surface models and the experimental results agreed greatly with the wetting trends estimated theoretically due to the geometrical regularity of the base micro-structures

  13. Characterisation of ictal and interictal states of epilepsy: A system dynamic approach of principal dynamic modes analysis.

    Directory of Open Access Journals (Sweden)

    Zabit Hameed

    Full Text Available Epilepsy is a brain disorder characterised by the recurrent and unpredictable interruptions of normal brain function, called epileptic seizures. The present study attempts to derive new diagnostic indices which may delineate between ictal and interictal states of epilepsy. To achieve this, the nonlinear modeling approach of global principal dynamic modes (PDMs is adopted to examine the functional connectivity of the temporal and frontal lobes with the occipital brain segment using an ensemble of paediatric EEGs having the presence of epileptic seizure. The distinct spectral characteristics of global PDMs are found to be in line with the neural rhythms of brain dynamics. Moreover, we find that the linear trends of associated nonlinear functions (ANFs associated with the 2nd and 4th global PDMs (representing delta, theta and alpha bands of Fp1-F3 may differentiate between ictal and interictal states of epilepsy. These findings suggest that global PDMs and their associated ANFs may offer potential utility as diagnostic neural measures for ictal and interictal states of epilepsy.

  14. Effects of Weightlessness on Human Fluid and Electrolyte Physiology

    Science.gov (United States)

    Leach, Carolyn S.; Johnson, Philip C., Jr.

    1991-01-01

    The changes that occur in human fluid and electrolyte physiology during the acute and adaptive phases of adaptation to spaceflight are summarized. A number of questions remain to be answered. At a time when plasma volume and extracellular fluid volume are contracted and salt and water intake is unrestricted. ADH does not correct the volume deficit and serum sodium decreases. Change in secretion or activity of a natriuretic factor during spaceflight is one possible explanation. Recent identification of a polypeptide hormone produced in cardiac muscle cells which is natiuretic, is hypotensive, and has an inhibitory effect on renin and aldosterone secretion has renewed interest in the role of a natriuretic factor. The role of this atrial natriuretic factor (ANF) in both long- and short-term variation in extracellular volumes and in the inability of the kidney to bring about an escape from the sodium-retaining state accompanying chronic cardiac dysfunction makes it reasonable to look for a role of ANF in the regulation of sodium during exposure to microgravity. Prostaglandin-E is another hormone that may antagonize the action of ADH. Assays of these hormones will be performed on samples from crew members in the future.

  15. Specialized protein products in broiler chicken nutrition: A review

    Directory of Open Access Journals (Sweden)

    Sleman S.M. Beski

    2015-06-01

    Full Text Available In poultry nutrition, most attention is given to protein products, due to the importance of protein as a major constituent of the biologically active compounds in the body. It also assists in the synthesis of body tissue, for that renovation and growth of the body. Furthermore, protein exists in form of enzymes and hormones which play important roles in the physiology of any living organism. Broilers have high dietary protein requirements, so identification of the optimum protein concentration in broiler diets, for either maximizing broiler performance or profit, requires more knowledge about birds' requirements for protein and amino acids and their effects on the birds' growth performance and development. It also requires knowledge about the protein sources available that can be used in poultry diets. The broad aim of this review is to highlight the importance of some of the available high-quality specialized protein products of both animal and plant origins which can be explored for feeding broiler chickens. Minimization of the concentration of anti-nutritional factors (ANFs and supplementation with immunologically active compounds are the main focus of gut health-promoting broiler diets. These diet characteristics are influenced by feed ingredient composition and feed processing. The general hypothesis is that these protein products are highly digestible and devoid of or contain less ANFs. Feeding these products to broiler chicks, especially at an earlier age, can assist early gut development and digestive physiology, and improve broiler growth performance and immunity.

  16. Effectiveness of the magnetic resonance imaging for the therapy of avascular necrosis of the femoral head

    International Nuclear Information System (INIS)

    Oda, Yoshinao; Katsuki, Ichirou; Ushijima, Masahiro; Tsutsui, Hideki; Sugioka, Youichi

    1990-01-01

    Recently, some reports demonstrate the usefulness of the magnetic resonance imaging (MRI) for early diagnosis of the avascular necrosis of the femoral head (ANF). In this report we analyzed 64 hips in 40 cases using preoperative plain radiographs, tomography and MRI affected by ANF. And we gained following three conclusions. When rotational osteotomy of the femoral head is to be carried out, two plain views of MRI, parallel and contrary to the axis of the femoral neck, were useful for evaluation of postoperative weight bearing area. In 58 hips with strinct the former two plain views of MRI, atrophy of posterior area of the femoral head was recognized in 54 hips by tomography, and of them abnormal signal in posterior was revealed in 32 hips by MRI. In 28 hips performed anterior rotational osteotomy, atrophy of posterior area of the femoral head was recognized in 26 hips by tomography, and of them abnormal signal in posterior was revealed in 6 hips by MRI. In such cases careful follow-up should be required. (author)

  17. Effectiveness of the magnetic resonance imaging for the therapy of avascular necrosis of the femoral head

    Energy Technology Data Exchange (ETDEWEB)

    Oda, Yoshinao; Katsuki, Ichirou; Ushijima, Masahiro; Tsutsui, Hideki; Sugioka, Youichi [Kyushu Univ., Fukuoka (Japan). Faculty of Medicine

    1990-03-01

    Recently, some reports demonstrate the usefulness of the magnetic resonance imaging (MRI) for early diagnosis of the avascular necrosis of the femoral head (ANF). In this report we analyzed 64 hips in 40 cases using preoperative plain radiographs, tomography and MRI affected by ANF. And we gained following three conclusions. When rotational osteotomy of the femoral head is to be carried out, two plain views of MRI, parallel and contrary to the axis of the femoral neck, were useful for evaluation of postoperative weight bearing area. In 58 hips with strinct the former two plain views of MRI, atrophy of posterior area of the femoral head was recognized in 54 hips by tomography, and of them abnormal signal in posterior was revealed in 32 hips by MRI. In 28 hips performed anterior rotational osteotomy, atrophy of posterior area of the femoral head was recognized in 26 hips by tomography, and of them abnormal signal in posterior was revealed in 6 hips by MRI. In such cases careful follow-up should be required. (author).

  18. Functional analysis of the novel TBX5 c.1333delC mutation resulting in an extended TBX5 protein

    Directory of Open Access Journals (Sweden)

    Ekman-Joelsson Britt-Marie

    2008-10-01

    Full Text Available Abstract Background Autosomal dominant Holt-Oram syndrome (HOS is caused by mutations in the TBX5 gene and is characterized by congenital heart and preaxial radial ray upper limb defects. Most of the TBX5 mutations found in patients with HOS cause premature truncation of the primary TBX5 transcript. TBX5 missense mutations alter the three-dimensional structure of the protein and result in failed nuclear localization or reduced binding to target DNA. In this study we present our functional analyses of the novel and unusual c.1333delC mutation found in a patient with classical HOS. Methods The functional impact of this novel mutation was assessed by investigating the intracellular localization of the resulting TBX5 protein and its ability to activate the expression of its downstream target ANF. Results The deletion of the cytosine is the first TBX5 frameshift mutation predicted to result in an elongated TBX5 protein with 74 miscoding amino acids and 62 supernumerary C-terminal amino acids. The c.1333delC mutation affects neither the nuclear localization, nor its colocalization with SALL4, but severely affects the activation of the ANF promoter. Conclusion The mutation c.1333delC does not locate within functional domains, but impairs the activation of the downstream target. This suggests that misfolding of the protein prevents its biological function.

  19. 3-Methylcholanthrene inhibits lymphocyte proliferation and increases intracellular calcium levels in common carp (Cyprinus carpio L)

    International Nuclear Information System (INIS)

    Reynaud, S.; Duchiron, C.; Deschaux, P.

    2003-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are an important class of environmental pollutants that are known to be carcinogenic and immunotoxic. Many authors have focused on macrophage activities in fish exposed to PAHs. However, fewer studies have reported decrease in specific immunity in such fish. We investigated the intracellular mechanisms by which the 3-methylcholanthrene (3-MC) decreased lymphocyte proliferation in carp. T- and B-lymphocyte proliferation induced by Concanavalin A (Con A) and lipopolysaccharide (LPS) were inhibited by 3-MC (0.5-50 μM). 3-MC also produced a rapid and a sustained increase in intracellular calcium concentration ([Ca 2+ ] i ) (2 h minimum). However, the cytochrome P450 1A and Ah receptor inhibitor, α-naphtoflavone (a-NF), also inhibited lymphocyte proliferation and did not reverse the effects of 3-MC. Moreover, since a-NF and 3-MC increased [Ca 2+ ] i and inhibited lymphocyte proliferation it was possible that calcium release played a role in 3-MC-inhibited lymphocyte proliferation. The rise in [Ca 2+ ] i induced by 3-MC was potentiated by the inhibitor of the endoplasmic reticulum calcium ATPases, thapsigargin. Treating cells with 3-MC decreased calcium mobilization caused by thapsigargin. These results suggest that 3-MC acts on the endoplasmic reticulum, perhaps directly on calcium ATPases, to increase intracellular calcium levels in carp leucocytes

  20. Human neural tuning estimated from compound action potentials in normal hearing human volunteers

    Science.gov (United States)

    Verschooten, Eric; Desloovere, Christian; Joris, Philip X.

    2015-12-01

    The sharpness of cochlear frequency tuning in humans is debated. Evoked otoacoustic emissions and psychophysical measurements suggest sharper tuning in humans than in laboratory animals [15], but this is disputed based on comparisons of behavioral and electrophysiological measurements across species [14]. Here we used evoked mass potentials to electrophysiologically quantify tuning (Q10) in humans. We combined a notched noise forward masking paradigm [9] with the recording of trans tympanic compound action potentials (CAP) from masked probe tones in awake human and anesthetized monkey (Macaca mulatta). We compare our results to data obtained with the same paradigm in cat and chinchilla [16], and find that CAP-Q10values in human are ˜1.6x higher than in cat and chinchilla and ˜1.3x higher than in monkey. To estimate frequency tuning of single auditory nerve fibers (ANFs) in humans, we derive conversion functions from ANFs in cat, chinchilla, and monkey and apply these to the human CAP measurements. The data suggest that sharp cochlear tuning is a feature of old-world primates.

  1. Process development for the manufacturing of state-of-the-art spacer grids

    Energy Technology Data Exchange (ETDEWEB)

    Schebitz, Florian; Dietrich, Matthias [Advanced Nuclear Fuels GmbH, Karlstein (Germany)

    2013-07-01

    At the beginning it was questioned if 'time to market' is really important for the nuclear industry. The clear answer is YES. Even if the development times might be longer compared to projects in other industries it is still beneficial to use concurrent engineering. In the world wide network of manufacturing sites, Advanced Nuclear Fuels GmbH in Karlstein is quite often involved when the development of new processes is necessary. As ANF Karlstein is delivering products around the world the experience with different customer requirements supports an optimized solution in order to fulfill these principle requirements and to deliver state-of-the-art products like spacer grids. Continues feedback from process development already improves the first prototypes. In the meantime ANF Karlstein manufactured the components for both new fuel assembly designs which are introduced as a first set of Lead Fuel Assemblies. For the manufacturing of the next sets of spacer grids (for tests and next series of Lead Fuel Assemblies) the described processes will be used and further improved, so that an industrialized solution is available. (orig.)

  2. Protein Solubility as Quality Index for Processed Soybean

    Directory of Open Access Journals (Sweden)

    Rodica Căpriţă

    2010-05-01

    Full Text Available Protein quality of soybean meal (SBM is linked to both the reduction of antinutritional factors (ANFs, and the optimization of protein digestibility. Both insufficient- and over-heating result in poor quality SBM. Inadequate heating fails to completely destroy the ANFs, which may have a detrimental impact on animal performance, while excessive heating reduces the availability of lysine via the Maillard reaction and possibly, to a lesser extent, of other amino acids. The objective of our study was to compare some biochemical laboratory procedures for assessing quality of SBM: urease index (UI, protein dispersibility index (PDI, KOH protein solubility (PS, and nitrogen solubility index (NSI. The experimental data reveal that UI is not useful to determine excessive heat treatment since additional heating has no effect on the urease index. KOH protein solubility remains high, during initial heat treatment. In marked contrast, the PDI and NSI decreased incrementally from 78% to 20% and from 97% to 60%, respectively, when heating 0 to 30 minutes. Combing the PDI test with the urease test could be useful to monitor soybean quality. SBM containing low UI (0.3 or below and high PDI (40 to 45% may indicate that the sample is definitely high quality because it has been adequately heat processed, but not overprocessed.

  3. Air pollution is associated with the development of atherosclerosis via the cooperation of CD36 and NLRP3 inflammasome in ApoE-/- mice.

    Science.gov (United States)

    Du, Xihao; Jiang, Shuo; Zeng, Xuejiao; Zhang, Jia; Pan, Kun; Zhou, Ji; Xie, Yuquan; Kan, Haidong; Song, Weimin; Sun, Qinghua; Zhao, Jinzhuo

    2018-06-15

    Previous studies have indicated that the main air pollutant fine particulate matter (≤2.5 μm; PM 2.5 ) exposure is associated with the development of atherosclerosis. Although the mechanism is not fully illustrated, the inflammatory responses play an important role. The present study aimed to explore whether PM 2.5 -exacerbated atherosclerosis was mediated by the cooperation of cluster of differentiation 36 (CD36) and nucleotide-binding oligomerization domain-like receptor protein (NLRP3) inflammasome in apolipoprotein E -/- (ApoE -/- ) mice. Thirty-two ApoE -/- mice were randomly divided into two groups. One group was fed with high fat chow (HFC) for 10 weeks to establish atherosclerotic model, and the other was fed with normal chow (NC). From week 11, the mice were exposed to concentrated PM 2.5 (PM) or filtered air (FA) using Shanghai Meteorological and Environmental Animal Exposure System for 16 weeks. In both NC and HFC groups, PM 2.5 exposure induced the formation of atherosclerosis plaque. Similarly, PM mice appeared higher lipid content in the aortic root than that in the FA mice. Compared with the FA mice, PM mice appeared a decrease in high density lipoprotein-cholesterol (HDL-C) and apolipoprotein A1 along with an increase in apolipoprotein B, low density lipoprotein-cholesterol (LDL-C) and oxidized low-density lipoprotein (ox-LDL). Moreover, PM 2.5 exposure induced increase of CD36 in serum and aorta. In both NC and HFC groups, NLRP3 inflammasome activation-related indicators were activated or increased in the aorta of the PM mice when compared with the FA mice. The cooperation of CD36 and NLRP3 inflammasome activation may be the potential mechanisms linkixposed to concentrated PM 2.5 (PM) or filtered air (FA) using Shanghai Meteorological and Environmental Animal Exposure System for 16 weeks. In both NC and HFC groups, PM 2.5 exposure induced the formation of atherosclerosis plaque. Similarly, PM mice appeared higher lipid content in the aortic

  4. The energy landscape of glassy dynamics on the amorphous hafnium diboride surface

    International Nuclear Information System (INIS)

    Nguyen, Duc; Girolami, Gregory S.; Mallek, Justin; Cloud, Andrew N.; Abelson, John R.; Lyding, Joseph; Gruebele, Martin

    2014-01-01

    Direct visualization of the dynamics of structural glasses and amorphous solids on the sub-nanometer scale provides rich information unavailable from bulk or conventional single molecule techniques. We study the surface of hafnium diboride, a conductive ultrahigh temperature ceramic material that can be grown in amorphous films. Our scanning tunneling movies have a second-to-hour dynamic range and single-point current measurements extend that to the millisecond-to-minute time scale. On the a-HfB 2 glass surface, two-state hopping of 1–2 nm diameter cooperatively rearranging regions or “clusters” occurs from sub-milliseconds to hours. We characterize individual clusters in detail through high-resolution (<0.5 nm) imaging, scanning tunneling spectroscopy and voltage modulation, ruling out individual atoms, diffusing adsorbates, or pinned charges as the origin of the observed two-state hopping. Smaller clusters are more likely to hop, larger ones are more likely to be immobile. HfB 2 has a very high bulk glass transition temperature T g , and we observe no three-state hopping or sequential two-state hopping previously seen on lower T g glass surfaces. The electronic density of states of clusters does not change when they hop up or down, allowing us to calibrate an accurate relative z-axis scale. By directly measuring and histogramming single cluster vertical displacements, we can reconstruct the local free energy landscape of individual clusters, complete with activation barrier height, a reaction coordinate in nanometers, and the shape of the free energy landscape basins between which hopping occurs. The experimental images are consistent with the compact shape of α-relaxors predicted by random first order transition theory, whereas the rapid hopping rate, even taking less confined motion at the surface into account, is consistent with β-relaxations. We make a proposal of how “mixed” features can show up in surface dynamics of glasses

  5. HFB7 - A novel orphan hydrophobin of the Harzianum and Virens clades of Trichoderma, is involved in response to biotic and abiotic stresses.

    Science.gov (United States)

    Przylucka, Agnes; Akcapinar, Gunseli Bayram; Chenthamara, Komal; Cai, Feng; Grujic, Marica; Karpenko, Juriy; Livoi, Miriam; Shen, Qirong; Kubicek, Christian P; Druzhinina, Irina S

    2017-05-01

    Hydrophobins are small secreted cysteine-rich proteins exclusively found in fungi. They are able to self-assemble in single molecular layers at hydrophobic-hydrophilic interfaces and can therefore be directly involved in establishment of fungi in their habitat. The genomes of filamentous mycotrophic fungi Trichoderma encode a rich diversity of hydrophobins, which are divided in several groups based on their structure and evolution. Here we describe a new member of class II hydrophobins, HFB7, that has a taxonomically restricted occurrence in Harzianum and Virens clades of Trichoderma. Evolutionary analysis reveals that HFB7 proteins form a separate clade distinct from other Trichoderma class II hydrophobins and that genes encoding them evolve under positive selection pressure. Homology modelling of HFB7 structure in comparison to T. reesei HFB2 reveals that the two large hydrophobic patches on the surface of the protein are remarkably conserved between the two hydrophobins despite significant difference in their primary structures. Expression of hfb7 gene in T. virens increases at interactions with other fungi and a plant and in response to a diversity of abiotic stress conditions, and is also upregulated during formation of aerial mycelium in a standing liquid culture. This upregulation significantly exceeds that of expression of hfb7 under a strong constitutive promoter, and T. virens strains overexpressing hfb7 thus display only changes in traits characterized by low hfb7 expression, i.e. faster growth in submerged liquid culture. The hfb7 gene is not expressed in conidia. Our data allow to conclude that this protein is involved in defence of Trichoderma against a diversity of stress factors related to the oxidative stress. Moreover, HFB7 likely helps in the establishment of the fungus in wetlands or other conditions related to high humidity. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Microhardness evaluation alloys Hf-Si-B; Avaliacao de microdureza de ligas Hf-Si-B

    Energy Technology Data Exchange (ETDEWEB)

    Gigolotti, Joao Carlos Janio; Costa, Eliane Fernandes Brasil [Centro Universitario de Volta Redonda (UNIFOA), Volta Redonda, RJ (Brazil); Nunes, Carlos Angelo; Rocha, Elisa Gombio; Coelho, Gilberto Carvalho, E-mail: carlosjanio@uol.com.br, E-mail: eliane-costabrasi@hotmail.com, E-mail: cnunes@demar.eel.usp.br, E-mail: elisarocha@alunos.eel.usp.br, E-mail: coelho@demar.eel.usp.br [Universidade de Sao Paulo (USP), Lorena, SP (Brazil)

    2014-08-15

    The technological advance has generated increasing demand for materials that can be used under high temperature, what includes intermetallic MR-Si-B (MR = refractory metal) alloys with multiphase structures, that can also be applied in oxide environments. Thus, this work had for objective the micro hardness study of the Hf-Si-B system alloys, heat treated at 1600 deg C, in the Hf rich region. Hf-Si-B alloys had been produced with blades of Hf (min. 99.8%), Si (min. 99.998%) and B (min. 99.5%), in the voltaic arc furnace and heat treated at 1600 deg C under argon atmosphere. The relationship of the phases had been previously identified by X-ray diffraction and contrast in backscattered electron imaging mode. The alloys had their hardness analyzed by method Vickers (micro hardness) with load of 0.05 kgf and 0.2 kgf and application time of 20 s. The results, obtained from the arithmetic mean of measurements for each alloy on the heterogeneous region, showed a mean hardness of 11.08 GPA, with small coefficient of variation of 3.8%. The borides HfB2 (19.34 GPa) e HfB - 11.76 GPa, showed the hardness higher than the silicides Hf2Si (8.57 GPa), Hf5Si3 (9.63 GPa), Hf3Si2 (11.66 GPa), Hf5Si4 (10.00 GPa), HfSi (10.02 GPa) e HfSi2 (8.61 GPa). (author)

  7. Direct facility funding as a response to user fee reduction: implementation and perceived impact among Kenyan health centres and dispensaries.

    Science.gov (United States)

    Opwora, Antony; Kabare, Margaret; Molyneux, Sassy; Goodman, Catherine

    2010-09-01

    There is increasing pressure for reduction of user fees, but this can have adverse effects by decreasing facility-level funds. To address this, direct facility funding (DFF) was piloted in Coast Province, Kenya, with health facility committees (HFCs) responsible for managing the funds. We evaluated the implementation and perceived impact 2.5 years after DFF introduction. Quantitative data collection at 30 public health centres and dispensaries included a structured interview with the in-charge, record reviews and exit interviews. In addition, in-depth interviews were conducted with the in-charge and HFC members at 12 facilities, and with district staff and other stakeholders. DFF procedures were well established: HFCs met regularly and accounting procedures were broadly followed. DFF made an important contribution to facility cash income, accounting for 47% in health centres and 62% in dispensaries. The main items of expenditure were wages for support staff (32%), travel (21%), and construction and maintenance (18%). DFF was perceived to have a highly positive impact through funding support staff such as cleaners and patient attendants, outreach activities, renovations, patient referrals and increasing HFC activity. This was perceived to have improved health worker motivation, utilization and quality of care. A number of problems were identified. HFC training was reportedly inadequate, and no DFF documentation was available at facility level, leading to confusion. Charging user fees above those specified in the national policy remained common, and understanding of DFF among the broader community was very limited. Finally, relationships between HFCs and health workers were sometimes characterized by mistrust and resentment. Relatively small increases in funding may significantly affect facility performance when the funds are managed at the periphery. Kenya plans to scale up DFF nationwide. Our findings indicate this is warranted, but should include improved training

  8. Emissions of halocarbons from mobile vehicle air conditioning system in Hong Kong

    International Nuclear Information System (INIS)

    Yan, H.H.; Guo, H.; Ou, J.M.

    2014-01-01

    Highlights: • Halocarbon emissions from MVACS were characterized using bottom up approach. • Quantification of emission inventory was revealed using AUV Tools. • Potential emission reduction was estimated under 3 possible mitigation scenarios. • The results are useful for the policy makers to formulate and implement future phase-out schedule. - Abstract: During the implementation of Montreal Protocol, emission inventories of halocarbons in different sectors at regional scale are fundamental to the formulation of relevant management strategy and inspection of the implementation efficiency. This study investigated the emission profile of halocarbons used in the mobile vehicle air conditioning system, the leading sector of refrigeration industry in terms of the refrigerant bank, market and emission, in the Hong Kong Special Administrative Region, using a bottom-up approach developed by 2006 IPCC Good Practice Guidance. The results showed that emissions of CFC-12 peaked at 53 tons ODP (Ozone Depletion Potential) in 1992 and then gradually diminished, whereas HFC-134a presented an increasing emission trend since 1990s and the emissions of HFC-134a reached 65,000 tons CO 2 -equivelant (CO 2 -eq) by the end of 2011. Uncertainty analysis revealed relatively high levels of uncertainties for special-purpose vehicles and government vehicles. Moreover, greenhouse gas (GHG) abatements under different scenarios indicated that potential emission reduction of HFC-134a ranged from 4.1 to 8.4 × 10 5 tons CO 2 -eq. The findings in this study advance our knowledge of halocarbon emissions from mobile vehicle air conditioning system in Hong Kong

  9. High temperature diffusion of hafnium in tungsten and a tungsten-hafnium carbide alloy

    International Nuclear Information System (INIS)

    Ozaki, Y.; Zee, R.H.

    1994-01-01

    Refractory metals and ceramics are used extensively in energy systems due to their high temperature properties. This is particularly important in direct conversion systems where thermal to electric conversion efficiency is a direct function of temperature. Tungsten, which has the highest melting temperature among elemental metals, does not possess sufficient creep resistance at temperature above 1,600 K. Different dispersion strengthened tungsten alloys have been developed to extend the usefulness of tungsten to higher temperatures. One of these alloys, tungsten with 0.4 mole percent of finely dispersed HfC particles (W-HfC), has the optimum properties for high temperature applications. Hafnium carbide is used as the strengthening agent due to its high chemical stability and its compatibility with tungsten. The presence of HfC particles retards the rate of grain growth as well as restricting dislocation motion. Both of which are beneficial for creep resistance. The long term behavior of this alloy depends largely on the evolution of its microstructure which is governed by the diffusion of its constituents. Data on the diffusion of carbon in tungsten and tungsten self-diffusion are available, but no direct measurements have been made on the diffusion of hafnium in tungsten. The only diffusion data available are estimated from a coarsening study and these data are highly unreliable. In this study, the diffusion behavior of hafnium in pure tungsten and in a W-HfC alloy was directly measured by means of Secondary Ion Mass Spectroscopy (SIMS). The selection of the W-HfC alloy is due to its importance in high temperature engineering applications, and its higher recrystallization temperature. The presence of HfC particles in tungsten restricts grain growth resulting in better high temperature creep resistance. The higher recrystallization temperature allows measurements to be made over a wider range of temperatures at a relatively constant grain size

  10. Emissions of halocarbons from mobile vehicle air conditioning system in Hong Kong

    Energy Technology Data Exchange (ETDEWEB)

    Yan, H.H.; Guo, H., E-mail: ceguohai@polyu.edu.hk; Ou, J.M.

    2014-08-15

    Highlights: • Halocarbon emissions from MVACS were characterized using bottom up approach. • Quantification of emission inventory was revealed using AUV Tools. • Potential emission reduction was estimated under 3 possible mitigation scenarios. • The results are useful for the policy makers to formulate and implement future phase-out schedule. - Abstract: During the implementation of Montreal Protocol, emission inventories of halocarbons in different sectors at regional scale are fundamental to the formulation of relevant management strategy and inspection of the implementation efficiency. This study investigated the emission profile of halocarbons used in the mobile vehicle air conditioning system, the leading sector of refrigeration industry in terms of the refrigerant bank, market and emission, in the Hong Kong Special Administrative Region, using a bottom-up approach developed by 2006 IPCC Good Practice Guidance. The results showed that emissions of CFC-12 peaked at 53 tons ODP (Ozone Depletion Potential) in 1992 and then gradually diminished, whereas HFC-134a presented an increasing emission trend since 1990s and the emissions of HFC-134a reached 65,000 tons CO{sub 2}-equivelant (CO{sub 2}-eq) by the end of 2011. Uncertainty analysis revealed relatively high levels of uncertainties for special-purpose vehicles and government vehicles. Moreover, greenhouse gas (GHG) abatements under different scenarios indicated that potential emission reduction of HFC-134a ranged from 4.1 to 8.4 × 10{sup 5} tons CO{sub 2}-eq. The findings in this study advance our knowledge of halocarbon emissions from mobile vehicle air conditioning system in Hong Kong.

  11. Looking for New Polycrystalline MC-Reinforced Cobalt-Based Superalloys Candidate to Applications at 1200°C

    Directory of Open Access Journals (Sweden)

    Patrice Berthod

    2017-01-01

    Full Text Available For applications for which temperatures higher than 1150°C can be encountered the currently best superalloys, the γ/γ′ single crystals, cannot be used under stress because of the disappearance of their reinforcing γ′ precipitates at such temperatures which are higher than their solvus. Cobalt-based alloys strengthened by refractory and highly stable carbides may represent an alternative solution. In this work the interest was focused on MC carbides of several types. Alloys were elaborated with atomically equivalent quantities in M element (among Ti, Ta, Nb, Hf, or Zr and in C. Script-like eutectic TiC, TaC, NbC, HfC, and ZrC carbides were successfully obtained in the interdendritic spaces. Unfortunately, only one type, HfC, demonstrated high morphological stability during about 50 hours at 1200°C. The concerned alloy, of the Co-25Cr-0.5C-7.4Hf type (in wt.%, was further characterized in flexural creep resistance and air-oxidation resistance at the same temperature. The creep behaviour was very good, notably by comparison with a more classical Co-25Cr-0.5C-7.5Ta alloy, proving that the interest of HfC is higher than the TaC one. In contrast the oxidation by air was faster and its behaviour not really chromia-forming. Significant improvements of this chemical resistance are expected before taking benefit from the mechanical superiority of this alloy.

  12. Synergistic effect of carbon nanotube as sintering aid and toughening agent in spark plasma sintered molybdenum disilicide-hafnium carbide composite

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Biswajyoti; Asiq Rahman, O.S.; Sribalaji, M [Materials Science and Engineering, Indian Institute of Technology Patna, Bihta Kanpa Road, Bihta, Patna, Bihar 801103 (India); Bakshi, Srinivasa Rao [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Keshri, Anup Kumar, E-mail: anup@iitp.ac.in [Materials Science and Engineering, Indian Institute of Technology Patna, Bihta Kanpa Road, Bihta, Patna, Bihar 801103 (India)

    2016-12-15

    Hafnium carbide (HfC) along with sintering aids was consolidated at a relatively lower temperature i.e. 1600 °C (i.e. T=~0.41 T{sub m}) under a uniaxial load of 50 MPa by spark plasma sintering. Two different sintering aids such as molybdenum disilicide (MoSi{sub 2}) and carbon nanotube (CNT) were added to enhance the densification and lower the extent of grain growth in the sintered pellets. Density of the sintered pellet increased from 96.0±0.8% in HfC +5 wt% MoSi{sub 2} (HM) to 99.0±0.5% with the addition of 2 wt% CNT in HfC+5 wt% MoSi{sub 2} (HMC) at sintering temperature of 1600 °C. Further, the extent of grain growth drastically reduced from 204% in HM to 50% in HMC. Analysis of linear shrinkage during densification revealed that CNT addition increased densification rate and decreased the time required to reach the density of 99.0±0.5% at 1600 °C. Increased densification and lower degree of grain growth could be due to the synergistic effect offered by the CNT, which are as follows: (i) Lubrication effect of CNT, (ii) Lower activation energy for grain boundary diffusion (iii) Reduction in liquid phase sintering temperature and (iv) Grain boundary pinning. Fracture toughness of the sintered HM and HMC composite was obtained using indentation technique. By the addition of 2 wt% CNT in HM, drastic increase of 91% in fracture toughness was seen. This significant improvement in fracture toughness was due to the enhanced densification and relatively lower grain size of HMC. Also crack bridging, crack deflection, crack arrest, CNT and graphene sheet pull-out and swording played major role in toughening of HMC pellet.

  13. Novel mechanisms for the vitamin D receptor (VDR) in the skin and in skin cancer.

    Science.gov (United States)

    Bikle, Daniel D; Oda, Yuko; Tu, Chia-Ling; Jiang, Yan

    2015-04-01

    The VDR acting with or without its principal ligand 1,25(OH)2D regulates two central processes in the skin, interfollicular epidermal (IFE) differentiation and hair follicle cycling (HFC). Calcium is an important co-regulator with 1,25(OH)2D at least of epidermal differentiation. Knockout of the calcium sensing receptor (CaSR) in addition to VDR accelerates the development of skin cancer in mice on a low calcium diet. Coactivators such as mediator 1 (aka DRIP205) and steroid receptor coactivator 3 (SRC3) regulate VDR function at different stages of the differentiation process, with Med 1 essential for hair follicle differentiation and early stages of epidermal differentiation and proliferation and SRC3 essential for the latter stages of differentiation including formation of the permeability barrier and innate immunity. The corepressor of VDR, hairless (HR), is essential for hair follicle cycling, although its effect on epidermal differentiation in vivo is minimal. In its regulation of HFC and IFE VDR controls two pathways-wnt/β-catenin and sonic hedgehog (SHH). In the absence of VDR these pathways are overexpressed leading to tumor formation. Whereas, VDR binding to β-catenin may block its activation of TCF/LEF1 sites, β-catenin binding to VDR may enhance its activation of VDREs. 1,25(OH)2D promotes but may not be required for these interactions. Suppression of SHH expression by VDR, on the other hand, requires 1,25(OH)2D. The major point of emphasis is that the role of VDR in the skin involves a number of novel mechanisms, both 1,25(OH)2D dependent and independent, that when disrupted interfere with IFE differentiation and HFC, predisposing to cancer formation. This article is part of a Special Issue entitled '17th Vitamin D Workshop'. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. HFCs contribution to the greenhouse effect. Present and projected estimations

    Energy Technology Data Exchange (ETDEWEB)

    Libre, J.M.; Elf-Atochem, S.A. [Central Research & Development, Paris (France)

    1997-12-31

    This paper reviews data that can be used to calculate hydrofluorocarbon (HFC) contribution to the greenhouse effect and compare it to other trace gas contributions. Projections are made for 2010 and 2100 on the basis of available emission scenarios. Industrial judgement on the likelihood of those scenarios is also developed. Calculations can be made in two different ways: from Global Warming Potential weighted emissions of species or by direct calculation of radiative forcing based on measured and projected atmospheric concentrations of compounds. Results show that HFCs corresponding to commercial uses have a negligible contribution to the greenhouse effect in comparison with other trace gases. The projected contributions are also very small even if very high emission scenarios are maintained for decades. In 2010 this contribution remains below 1%. Longer term emissions projections are difficult. However, based on the IPCC scenario IS92a, in spite of huge emissions projected for the year 2100, the HFC contribution remains below 3%. Actually many factors indicate that the real UFC contribution to the greenhouse effect will be even smaller than presented here. Low emissive systems and small charges will likely improve sharply in the future and have drastically improved in the recent past. HFC technology implementation is likely to grow in the future, reach a maximum before the middle of the next century; the market will stabilise driven by recycling, closing of systems and competitive technologies. This hypothesis is supported by previous analysis of the demand for HTCs type applications which can be represented by {open_quotes}S{close_quotes} type curves and by recent analysis indicating that the level of substitution of old products by HFCs is growing slowly. On the basis of those data and best industrial judgement, the contribution of HFCs to the greenhouse effect is highly likely to remain below 1% during the next century. 11 refs., 2 figs., 5 tabs.

  15. Effects of superfine refractory carbide additives on microstructure and mechanical properties of TiB2–TiC+Al2O3 composite ceramic cutting tool materials

    International Nuclear Information System (INIS)

    Zou, Bin; Ji, Wenbin; Huang, Chuanzhen; Wang, Jun; Li, Shasha; Xu, Kaitao

    2014-01-01

    Highlights: • The superfine carbides determined the mechanical properties of composites. • Superfine HfC or TaC caused some oxide impurities in composites. • Superfine VC or NbC refined and homogenized the microstructure. • Failure of composites containing HfC or TaC was produced by larger grains. • Composite containing VC exhibited more bridging and transcrystalline failure. -- Abstract: A study to increase the mechanical properties of TiB 2 –TiC+Al 2 O 3 composite ceramic cutting tool material by using superfine refractory carbide additives is presented. Four superfine refractory carbides are considered to investigate their effects on the phase composition, element distribution, grain size, fracture surface, crack propagation of the metal ceramic. The physicochemical properties of superfine carbides, such as chemical activities and atom radius, were found to have the significant effects on the microstructure and mechanical properties of the metal ceramic. Hafnium carbide (HfC) and Tantalum carbide (TaC) reduced the mechanical properties of the metal ceramic because of their poor solubility with the Ni binder phase and the formation of oxides. The mechanical properties of the metal ceramic were increased by the addition of superfine niobium carbide (NbC) and vanadium carbide (VC), and their optimum values were a flexural strength of 1100 ± 62 MPa, fracture toughness of 8.5 ± 0.8 MPa.m1/2 and hardness of 21.53 ± 0.36 GPa, respectively, when 3.2 wt% superfine VC was used

  16. Experimental Study of Flow Boiling Heat Transfer in a Horizontal Microfin Tube

    OpenAIRE

    Yu, Jian; Koyama, Shigeru; Momoki, Satoru

    1995-01-01

    An experimental study on flow boiling heat transfer in a horizontal microfin tube is conducted with pure refrigerants HFC134a, HCFC123 and HCFC22 using a water-heated double-tube type test section. The test microfin tube is a copper tube having the following dimensions: 8.37mm mean inside diameter, 0.168mm fin height, 60fin number and 18 degree of helix angle. The local heat transfer coefficients for both counter and parallel flows are measured in a range of heat flux of 1 to 93W/m^2, mass ve...

  17. Experimental study on void fraction of two-phase flow inside a micro-fin tube

    OpenAIRE

    Koyama, Shigeru; Chen, Yongchang; Kitano, Ryuji; Kuwahara, Ken

    2001-01-01

    In this paper the void fraction and flow pattern of the two-phase flow in a micro-fin tube were investigated experimentally for a pure refrigerant HFC134a. The experiment was carried out at a pressure range of 0.6 and 1.2MPa with mass velocities of 90 and 180kg/m^2 s, in which the vapor quality varied from 0 to 1. The void fraction was measured by means of simultaneously closing valves of both sides of the test tube at adiabatic condition. Experimental results for the micro-fin tube were comp...

  18. 01 - The sustainable management of radioactive materials with fourth-generation reactors

    International Nuclear Information System (INIS)

    2012-12-01

    This publication first explains the reasons for the development of fourth-generation nuclear systems: the issue of resources, the issue of used fuels, technologies for fast breeder fourth-generation reactors, the alternative of HFC-cooled light water reactors, the potential market for fast-breeder reactors, strategies in different countries. Then, the authors address the strategy development for these fourth-generation reactors: requirements, safety, economic competitiveness, resistance to proliferation, flexible management of nuclear resources, development scheme (sodium or gas-based heat transfer), and fuel cycle. They finally discuss the possible transition scenarios towards this new generation

  19. Halogenated greenhouse gases at the Swiss High Alpine Site of Jungfraujoch (3580 m asl): Continuous measurements and their use for regional European source allocation

    Science.gov (United States)

    Reimann, Stefan; Schaub, Daniel; Stemmler, Konrad; Folini, Doris; Hill, Matthias; Hofer, Peter; Buchmann, Brigitte; Simmonds, Peter G.; Greally, Brian R.; O'Doherty, Simon

    2004-03-01

    At the high Alpine site of Jungfraujoch (3580 m asl), 23 halogenated greenhouse gases are measured quasi-continuously by gas chromatography-mass spectrometry (GCMS). Measurement data from the years 2000-2002 are analyzed for trends and pollution events. Concentrations of the halogenated trace gases, which are already controlled in industrialized countries by the Montreal Protocol (e.g., CFCs) were at least stable or declining. Positive trends in the background concentrations were observed for substances which are used as CFC-substitutes (hydrofluorocarbons, hydrochlorofluorocarbons). Background concentrations of the hydrofluorocarbons at the Jungfraujoch increased from January 2000 until December 2002 as follows: HFC 134a (CF3CH2F) from 15 to 27 ppt, HFC 125 (CF3CHF2) from 1.4 to 2.8 ppt, and HFC 152a (CHF2CH3) from 2.3 to 3.2 ppt. For HFC 152a, a distinct increase of its concentration magnitude during pollution events was observed from 2000 to 2002, indicating rising European emissions for this compound. Background concentrations of all measured compounds were in good agreement with similar measurements at Mace Head, Ireland. On the other hand, peak concentrations were significantly higher at the Jungfraujoch. This finding is due to the proximity to potent European sources, foremost in southern Europe. The average ratio of halocarbons versus carbon monoxide (CO) concentrations above their baseline values was used to estimate source strengths for the part of Europe which most influences the Jungfraujoch during pollution events. HFCs emission estimates from Jungfraujoch tend to be higher than figures at Mace Head (Ireland) from the end of the 1990s, which either reflects the increased use of these compounds or the closer location of Jungfraujoch to major southern European sources. Transport of polluted European boundary layer air masses to the high Alpine site was observed especially during frontal passages, foehn events, and thermal lifting of air masses in summer

  20. High-dose supplementation with natural α-tocopherol does neither alter the pharmacodynamics of atorvastatin nor its phase I metabolism in guinea pigs

    International Nuclear Information System (INIS)

    Podszun, Maren C.; Grebenstein, Nadine; Hofmann, Ute; Frank, Jan

    2013-01-01

    It has been hypothesized in the literature that intake of high-dosage vitamin E supplements might alter the expression of cytochrome P 450 enzymes (CYP), particularly CYP3A4, which may lead to adverse nutrient–drug interactions. Because previously published studies reported conflicting findings, we investigated the pharmacodynamics of the lipid-lowering drug atorvastatin (ATV), a CYP3A4 substrate, in response to high-dose α-tocopherol (αT) feeding and determined protein expression and activities of relevant CYP. Groups of ten female Dunkin–Hartley guinea pigs were fed a control (5% fat) or a high-fat control diet (HFC; 21% fat, 0.15% cholesterol) or the HFC diet fortified with αT (250 mg/kg diet), ATV (300 mg/kg diet) or both ATV + αT for 6 weeks. Relative to control, HFC animals had increased serum cholesterol concentrations, which were significantly reduced by ATV. High-dose αT feeding in combination with ATV (ATV + αT), albeit not αT feeding alone (αT), significantly lowered serum cholesterol relative to HFC, but did not alter the cholesterol-lowering activity of the drug compared to the ATV treated guinea pigs. Protein expression of CYP3A4, CYP4F2, CYP20A1 and OATP C was similar in all groups. Accordingly, no differences in plasma concentrations of phase I metabolites of ATV were observed between the ATV and ATV + αT groups. In conclusion, feeding guinea pigs high-doses of αT for 6 weeks did neither alter the hepatic expression of CYP, nor the pharmacodynamics and metabolism of ATV. High-dose αT intake is thus unlikely to change the efficacy of drugs metabolized by CYP enzymes, particularly by CYP3A4. -- Highlights: ► Vitamin E-atorvastatin interactions were studied in hypercholesterolemic guinea pigs. ► High-dose α-tocopherol did not alter the lipid-lowering efficacy of atorvastatin. ► α-Tocopherol did not change the expression of CYP3A4, CYP4F2, CYP20A or OATP C. ► α-Tocopherol did not affect phase I metabolism of atorvastatin.

  1. High-dose supplementation with natural α-tocopherol does neither alter the pharmacodynamics of atorvastatin nor its phase I metabolism in guinea pigs

    Energy Technology Data Exchange (ETDEWEB)

    Podszun, Maren C.; Grebenstein, Nadine [Institute of Biological Chemistry and Nutrition, University of Hohenheim, D-70599 Stuttgart (Germany); Hofmann, Ute [Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, D-70376 Stuttgart (Germany); Frank, Jan [Institute of Biological Chemistry and Nutrition, University of Hohenheim, D-70599 Stuttgart (Germany); Department of Nutrition and Food Science, University of Bonn, D-53115 Bonn (Germany)

    2013-02-01

    It has been hypothesized in the literature that intake of high-dosage vitamin E supplements might alter the expression of cytochrome P{sub 450} enzymes (CYP), particularly CYP3A4, which may lead to adverse nutrient–drug interactions. Because previously published studies reported conflicting findings, we investigated the pharmacodynamics of the lipid-lowering drug atorvastatin (ATV), a CYP3A4 substrate, in response to high-dose α-tocopherol (αT) feeding and determined protein expression and activities of relevant CYP. Groups of ten female Dunkin–Hartley guinea pigs were fed a control (5% fat) or a high-fat control diet (HFC; 21% fat, 0.15% cholesterol) or the HFC diet fortified with αT (250 mg/kg diet), ATV (300 mg/kg diet) or both ATV + αT for 6 weeks. Relative to control, HFC animals had increased serum cholesterol concentrations, which were significantly reduced by ATV. High-dose αT feeding in combination with ATV (ATV + αT), albeit not αT feeding alone (αT), significantly lowered serum cholesterol relative to HFC, but did not alter the cholesterol-lowering activity of the drug compared to the ATV treated guinea pigs. Protein expression of CYP3A4, CYP4F2, CYP20A1 and OATP C was similar in all groups. Accordingly, no differences in plasma concentrations of phase I metabolites of ATV were observed between the ATV and ATV + αT groups. In conclusion, feeding guinea pigs high-doses of αT for 6 weeks did neither alter the hepatic expression of CYP, nor the pharmacodynamics and metabolism of ATV. High-dose αT intake is thus unlikely to change the efficacy of drugs metabolized by CYP enzymes, particularly by CYP3A4. -- Highlights: ► Vitamin E-atorvastatin interactions were studied in hypercholesterolemic guinea pigs. ► High-dose α-tocopherol did not alter the lipid-lowering efficacy of atorvastatin. ► α-Tocopherol did not change the expression of CYP3A4, CYP4F2, CYP20A or OATP C. ► α-Tocopherol did not affect phase I metabolism of atorvastatin

  2. United States: refrigeration industry blows hot

    International Nuclear Information System (INIS)

    Crawford, J.

    1997-01-01

    In the framework of the Kyoto convention on global warming, the american refrigeration industries have undertaken several organizations and contacts with governments and agencies in order to explain the real issues concerning the effects of refrigerant utilization in refrigerating machines on the greenhouse effect, taking into consideration the commercial impact that a ban on certain refrigerants could have on the industry's business. They argue that HFC utilization in this industry is fundamentally non-emissive and that important improvements have been realized concerning tightness and energy consumption

  3. Structure and property evaluation of a vacuum plasma sprayed nanostructured tungsten-hafnium carbide bulk composite

    International Nuclear Information System (INIS)

    Rea, K.E.; Viswanathan, V.; Kruize, A.; Hosson, J.Th.M. de; O'Dell, S.; McKechnie, T.; Rajagopalan, S.; Vaidyanathan, R.; Seal, S.

    2008-01-01

    Vacuum plasma spray (VPS) forming of tungsten-based metal matrix nanocomposites (MMCs) has shown to be a cost effective and time saving method for the formation of bulk monolithic nanostructured thermo-mechanical components. Spray drying of powder feedstock appears to have a significant effect on the improved mechanical properties of the bulk nanocomposite. The reported elastic modulus of the nanocomposite nearly doubles due to the presence of HfC nano particulates in the W matrix. High resolution transmission electron microscopy (HRTEM) revealed the retention of nanostructures at the select process conditions and is correlated with the enhanced mechanical properties of the nanocomposite

  4. A study of the radiative forcing and global warming potentials of hydrofluorocarbons

    International Nuclear Information System (INIS)

    Zhang Hua; Wu Jinxiu; Lu Peng

    2011-01-01

    We developed a new radiation parameterization of hydrofluorocarbons (HFCs), using the correlated k-distribution method and the high-resolution transmission molecular absorption (HITRAN) 2004 database. We examined the instantaneous and stratospheric adjusted radiative efficiencies of HFCs for clear-sky and all-sky conditions. We also calculated the radiative forcing of HFCs from preindustrial times to the present and for future scenarios given by the Intergovernmental Panel on Climate Change Special Report on Emission Scenarios (SRES, in short). Global warming potential and global temperature potential were then examined and compared on the basis of the calculated radiative efficiencies. Finally, we discuss surface temperature changes due to various HFC emissions.

  5. MO-HF-C alloy composition

    International Nuclear Information System (INIS)

    Whelan, E.P.; Kalns, E.

    1987-01-01

    This patent describes, as an article of manufacture, a cast ingot of a molybdenum-hafnium-carbon alloy consisting essentially by weight of about 0.6% to about 1% Hf, about 0.045% to about 0.08% C, and the balance essentially molybdenum. The amount of Hf and C present are substantially stoichiometric with respect to HfC and within about +-15% of stoichiometry. The ingot is characterized in that it has a substantially less tendency to crack compared to alloys containing Hf in excess of about 1% by weight and carbon in excess of 0.08% by weight, without substantial diminution in strength properties of the alloy

  6. Experimental results for hydrocarbon refrigerant vaporization inside brazed plate heat exchangers at high pressure

    DEFF Research Database (Denmark)

    Desideri, Adriano; Ommen, Torben Schmidt; Wronski, Jorrit

    2016-01-01

    fluids at typical working conditions of ORC systems for low temperature waste heat recovery (WHR) applications. Based on these premises, a novel testrig has been recently designed and built at the Technical University of Denmark to simulate the evaporating condition occurring in a small capacity ORC...... power unit. In this contribution the preliminary experimental results obtained from the first experimental campaign carried out on the rig are reported. HFC-134a was selected as working fluid. The experiments were carried out at saturation temperature of 60, 70 and 80 °C and inlet and outlet qualities...

  7. An experimental analysis of flow boiling and pressure drop in a brazed plate heat exchanger for organic Rankine cycle power systems

    DEFF Research Database (Denmark)

    Desideri, Adriano; Zhang, Ji; Kærn, Martin Ryhl

    2017-01-01

    Organic Rankine cycle power systems for low quality waste heat recovery applications can play a major role in achieving targets of increasing industrial processes efficiency and thus reducing the emissions of greenhouse gases. Low capacity organic Rankine cycle systems are equipped with brazed...... and pressure drop during vaporization at typical temperatures for low quality waste heat recovery organic Rankine cycle systems are presented for the working fluids HFC-245fa and HFO-1233zd. The experiments were carried out at saturation temperatures of 100°C, 115°C and 130°C and inlet and outlet qualities...

  8. World cheating on the carbon market

    International Nuclear Information System (INIS)

    James, O.

    2010-01-01

    According to several non-governmental organizations, some industrial producers take advantage of a flaw in one of the carbon market mechanisms set up by the Kyoto protocol. These industrialists, mainly from China and India, are involved in the production of HCFC22 refrigerants, and make a substantial profit by artificially generating more greenhouse gases (HFC23) than necessary, then destroying them in order to collect carbon credits which they sell on the carbon market. Explanations about the cheat, details about companies and banks involved in the system, review of past trickeries in carbon quotas, and ways to improve the carbon market are presented

  9. Air emissions in France overseas substances involved in the acidification, eutrophication, photochemical and greenhouse effect processes; Emissions dans l'air en France Outre-mer substances impliquees dans les phenomenes d'acidification, de photochimie et d'effet de serre

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-06-01

    The concerned substances are SO{sub 2} and NO{sub x} for the DOM (overseas departments); the six direct greenhouse gases (CO{sub 2}, CH{sub 4}, N{sub 2}O, HFC, PFC and SF{sub 6}) and non direct gases (VOC, CO, NO{sub x}, and SO{sub 2}) for the overseas departments and territories; the NH{sub 3} emissions for the eutrophication. Emissions are presented by the mean of charts. (A.L.B.)

  10. Denmark's national inventory report 2008 - Submitted under the United Nations framework convention on climate change, 1990-2006. Emission inventories

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Ole-Kenneth; Lyck, E.; Hjorth Mikkelsen, M. (and others)

    2008-05-15

    This report is Denmark's National Inventory Report reported to the Conference of the Parties under the United Nations Framework Convention on Climate Change (UNFCCC) due by 15 April 2008. The report contains information on Denmark's inventories for all years' from 1990 to 2006 for CO{sub 2}, CH{sub 4}, N{sub 2}O, HFC{sub s}, PFC{sub s} and SF{sub 6}, CO, NMVOC, SO{sub 2}. (au)

  11. An inexpensive and fast method for infiltration coating of complex geometry matrices for ISOL production target applications

    International Nuclear Information System (INIS)

    Kawai, Y.; Alton, G.D.; Bilheux, J.-C.

    2005-01-01

    An inexpensive, fast, and close to universal infiltration coating technique has been developed for fabricating fast diffusion-release ISOL targets. Targets are fabricated by deposition of finely divided (∼1μm) compound materials in a paint-slurry onto highly permeable, complex structure reticulated-vitreous-carbon-foam (RVCF) matrices, followed by thermal heat treatment. In this article, we describe the coating method and present information on the physical integrity, uniformity of deposition, and matrix adherence of SiC, HfC and UC 2 targets, destined for on-line use as targets at the Holifield Radioactive Ion Beam Facility (HRIBF)

  12. A review of chromium, molybdenum, and tungsten alloys

    International Nuclear Information System (INIS)

    Klopp, W.D.

    1975-01-01

    The mechanical properties of chromium, molybdenum, and tungsten alloys are reviewed, with particular emphasis on high-temperature strength and low-temperature ductility. Precipitate strengthening is highly effective at 0.4-0.8 Tsub(m) in these metals, with HfC being most effective in tungsten and molybdenum, and Ta(B,C) most effective in chromium. Low-temperature ductility can be improved by alloying to promote rhenium ductilizing or solution softening. The low-temperature mechanical properties of these alloys appear related to electronic interactions rather than to the usual metallurgical considerations. (Auth.)

  13. Estimation of Freezing Point of Hydrocarbon and Hydrofluorocarbon Mixtures for Mixed Refrigerant jt Cryocooler

    Science.gov (United States)

    Hwang, G.; Lee, J.; Jeong, S.

    2010-04-01

    Estimating the freezing point of refrigerant is an essential part in designing an MR JT (Mixed refrigerant Joule-Thomson) cryocooler to prevent itself from clogging and to operate with stability. There were researches on estimating freezing point, but some of them resulted in the wrong prediction of clogging. In this paper, the freezing point of the MR is precisely estimated with caution of clogging. The solubility of HC (hydrocarbon) and HFC (hydrofluorocarbon) mixture components are obtained with their activity coefficients, which represent the molecular interaction among the components. The freezing points of the MR JT cryocooler are systematically investigated in the operating temperature range from 70 K to 90 K.

  14. Properties of carbides and hard metals. Pt. 1

    International Nuclear Information System (INIS)

    Nazare, S.; Ondracek, G.

    1977-01-01

    Measurements of the electrical resistivity and of the Young modulus are reported for the carbides TiC, HfC, NbC, and TaC. The investigations included the solid solutions TiC-HfC, HfC-NbC, TaC-NbC, and TiC-NbC. For the solid solutions, measurements of the thermal expansion in the range 293-1173 K are also reported. All the samples were prepared by hot pressing of the commercial powders in graphite dies. The chemical composites are also presented. The measurement results are shown in figures. (GSC) [de

  15. Department of the Navy Justification of Estimates for Fiscal Year 1988/1989 Submitted to Congress. Procurement. Other Procurement, Navy.

    Science.gov (United States)

    1987-01-01

    7 7ZD- AISI 9721 PffARTMENT OF THE NAVY JUffjA~j HFC S A FO L/L U I (NAUil) WASHINC ON C JAN&LNCLASS IFI ED F/G 5/1 NL I M2 I12 5 coo~ LIFJ -I LII...0 4 4)-s.. -4 4J C: 00 + ,. LI0a 4)00&.4. 00a 4)CA.V f0 4- > 1 - 1 404- 4JLA. 0- =. i.- >, 0h0 a0 cn 4 (40 s.4 > 4 24*~ (-A *.eZ---. 0. .. ., tv 4140

  16. Sister chromatid exchanges and micronuclei analysis in lymphocytes of men exposed to simazine through drinking water.

    Science.gov (United States)

    Suárez, Susanna; Rubio, Arantxa; Sueiro, Rosa Ana; Garrido, Joaquín

    2003-06-06

    In some cities of the autonomous community of Extremadura (south-west of Spain), levels of simazine from 10 to 30 ppm were detected in tap water. To analyse the possible effect of this herbicide, two biomarkers, sister chromatid exchanges (SCE) and micronuclei (MN), were used in peripheral blood lymphocytes from males exposed to simazine through drinking water. SCE and MN analysis failed to detect any statistically significant increase in the people exposed to simazine when compared with the controls. With respect to high frequency cells (HFC), a statistically significant difference was detected between exposed and control groups.

  17. Recoilless fractions calculated with the nearest-neighbour interaction model by Kagan and Maslow

    Science.gov (United States)

    Kemerink, G. J.; Pleiter, F.

    1986-08-01

    The recoilless fraction is calculated for a number of Mössbauer atoms that are natural constituents of HfC, TaC, NdSb, FeO, NiO, EuO, EuS, EuSe, EuTe, SnTe, PbTe and CsF. The calculations are based on a model developed by Kagan and Maslow for binary compounds with rocksalt structure. With the exception of SnTe and, to a lesser extent, PbTe, the results are in reasonable agreement with the available experimental data and values derived from other models.

  18. JPRS Report Science & Technology Japan Future Prospects of FA-From FA to IMS

    Science.gov (United States)

    1989-12-04

    of FA Investment (Large Companies) a) m d) m 5000fI~ljl|S 1 m± ¥-1$ 500~1000t| 300~500(f 1000~3000ft i) £ÜÜ 0i!§£3^ SWOT # H^fc3S j) k) 1...is a method conceived by Toyota Motors, now widely understood throughout the world. Such information as the production volume, time, method and...T. Suzuki Toyota Motor Corp. Y. Tatsue AIST, Mechanical Engineering Laboratory K. Togino Komatsu Ltd. H. Torii Nihon Keizai Shimbun Editorial

  19. Dissociative properties of 1,1,1,2-tetrafluoroethane obtained by computational chemistry

    Science.gov (United States)

    Hayashi, Toshio; Ishikawa, Kenji; Sekine, Makoto; Hori, Masaru

    2018-06-01

    The electronic properties and dissociative channels of the alternative to the CCl2F2 (CFC-12) refrigerant, 1,1,1,2-tetrafluoroethane (HFC-134a) with a low global warming potential (GWP, 1430), were revealed by computational chemistry. The results show that CF3 + and CHF2 + ions are mainly produced by ionization. The CF3CH2 + ion is produced by ion pair formation and by direct ionization in the energy region higher than approximately 15 eV, but also in small amounts by the ionization of the dissociated CF3CH2 radical. This information is useful for etching process engineers in leading-edge semiconductor manufacturing.

  20. Broadband network selection issues

    Science.gov (United States)

    Leimer, Michael E.

    1996-01-01

    Selecting the best network for a given cable or telephone company provider is not as obvious as it appears. The cost and performance trades between Hybrid Fiber Coax (HFC), Fiber to the Curb (FTTC) and Asymmetric Digital Subscriber Line networks lead to very different choices based on the existing plant and the expected interactive subscriber usage model. This paper presents some of the issues and trades that drive network selection. The majority of the Interactive Television trials currently underway or planned are based on HFC networks. As a throw away market trial or a short term strategic incursion into a cable market, HFC may make sense. In the long run, if interactive services see high demand, HFC costs per node and an ever shrinking neighborhood node size to service large numbers of subscribers make FTTC appear attractive. For example, thirty-three 64-QAM modulators are required to fill the 550 MHz to 750 MHz spectrum with compressed video streams in 6 MHz channels. This large amount of hardware at each node drives not only initial build-out costs, but operations and maintenance costs as well. FTTC, with its potential for digitally switching large amounts of bandwidth to an given home, offers the potential to grow with the interactive subscriber base with less downstream cost. Integrated telephony on these networks is an issue that appears to be an afterthought for most of the networks being selected at the present time. The major players seem to be videocentric and include telephony as a simple add-on later. This may be a reasonable view point for the telephone companies that plan to leave their existing phone networks untouched. However, a phone company planning a network upgrade or a cable company jumping into the telephony business needs to carefully weigh the cost and performance issues of the various network choices. Each network type provides varying capability in both upstream and downstream bandwidth for voice channels. The noise characteristics

  1. Efficient sub-Doppler transverse laser cooling of an indium atomic beam

    International Nuclear Information System (INIS)

    Kim, Jae-Ihn

    2009-01-01

    Laser cooled atomic gases and atomic beams are widely studied samples in experimental research in atomic and optical physics. For the application of ultra cold gases as model systems for e.g. quantum many particle systems, the atomic species is not very important. Thus this field is dominated by alkaline, earthalkaline elements which are easily accessible with conventional laser sources and have convenient closed cooling transition. On the other hand, laser cooled atoms may also be interesting for technological applications, for instance for the creation of novel materials by atomic nanofabrication (ANF). There it will be important to use technologically relevant materials. As an example, using group III atoms of the periodical table in ANF may open a route to generate fully 3D structured composite materials. The minimal requirement in such an ANF experiment is the collimation of an atomic beam which is accessible by one dimensional laser cooling. In this dissertation, I describe transverse laser cooling of an Indium atomic beam. For efficient laser cooling on a cycling transition, I have built a tunable, continuous-wave coherent ultraviolet source at 326 nm based on frequency tripling. For this purpose, two independent high power Yb-doped fiber amplifiers for the generation of the fundamental radiation at λ ω = 977 nm have been constructed. I have observed sub-Doppler transverse laser cooling of an Indium atomic beam on a cycling transition of In by introducing a polarization gradient in the linear-perpendicular-linear configuration. The transverse velocity spread of a laser-cooled In atomic beam at full width at half maximum was achieved to be 13.5±3.8 cm/s yielding a full divergence of only 0.48 ± 0.13 mrad. In addition, nonlinear spectroscopy of a 3-level, Λ-type level system driven by a pump and a probe beam has been investigated in order to understand the absorption line shapes used as a frequency reference in a previous two-color spectroscopy experiment

  2. Measurement of atmospheric pollutants associated with oil and natural gas exploration and production activity in Pennsylvania's Allegheny National Forest.

    Science.gov (United States)

    Pekney, Natalie J; Veloski, Garret; Reeder, Matthew; Tamilia, Joseph; Rupp, Erik; Wetzel, Alan

    2014-09-01

    Oil and natural gas exploration and production (E&P) activities generate emissions from diesel engines, compressor stations, condensate tanks, leaks and venting of natural gas, construction of well pads, and well access roads that can negatively impact air quality on both local and regional scales. A mobile, autonomous air quality monitoring laboratory was constructed to collect measurements of ambient concentrations of pollutants associated with oil and natural gas E&P activities. This air-monitoring laboratory was deployed to the Allegheny National Forest (ANF) in northwestern Pennsylvania for a campaign that resulted in the collection of approximately 7 months of data split between three monitoring locations between July 2010 and June 2011. The three monitoring locations were the Kane Experimental Forest (KEF) area in Elk County, which is downwind of the Sackett oilfield; the Bradford Ranger Station (BRS) in McKean County, which is downwind of a large area of historic oil and gas productivity; and the U.S. Forest Service Hearts Content campground (HC) in Warren County, which is in an area relatively unimpacted by oil and gas development and which therefore yielded background pollutant concentrations in the ANF. Concentrations of criteria pollutants ozone and NO2 did not vary significantly from site to site; averages were below National Ambient Air Quality Standards. Concentrations of volatile organic compounds (VOCs) associated with oil and natural gas (ethane, propane, butane, pentane) were highly correlated. Applying the conditional probability function (CPF) to the ethane data yielded most probable directions of the sources that were coincident with known location of existing wells and activity. Differences between the two impacted and one background site were difficult to discern, suggesting the that the monitoring laboratory was a great enough distance downwind of active areas to allow for sufficient dispersion with background air such that the localized

  3. The Central and Eastern U.S. Seismic Network: Legacy of USArray

    Science.gov (United States)

    Eakins, J. A.; Astiz, L.; Benz, H.; Busby, R. W.; Hafner, K.; Reyes, J. C.; Sharer, G.; Vernon, F.; Woodward, R.

    2014-12-01

    As the USArray Transportable Array entered the central and eastern United States, several Federal agencies (National Science Foundation, U.S. Geological Survey, U.S. Nuclear Regulatory Commission, and Department of Energy) recognized the unique opportunity to retain TA stations beyond the original timeline. The mission of the CEUSN is to produce data that enables researchers and Federal agencies alike to better understand the basic geologic questions, background earthquake rates and distribution, seismic hazard potential, and associated societal risks of this region. The selected long-term sub-array from Transportable Array (TA) stations includes nearly 200 sites, complemented by 100 broadband stations from the existing regional seismic networks to form the Central and Eastern United States Network (CEUSN). Multiple criteria for site selection were weighed by an inter-agency TA Station Selection (TASS) Working Group: seismic noise characteristics, data availability in real time, proximity to nuclear power plants, and homogeneous distribution throughout the region. The Array Network Facility (ANF) started collecting data for CEUSN network stations since late 2013, with all stations collected since May 2014. Regional seismic data streams are collected in real-time from the IRIS Data Management Center (DMC). TA stations selected to be part of CEUSN, retain the broadband sensor to which a 100 sps channel is added, the infrasound and environmental channels, and, at some stations, accelerometers are deployed. The upgraded sites become part of the N4 network for which ANF provides metadata and can issue remote commands to the station equipment. Stations still operated by TA, but planned for CEUSN, are included in the virtual network so all stations are currently available now. By the end of 2015, the remaining TA stations will be upgraded. Data quality control procedures developed for TA stations at ANF and at the DMC are currently performed on N4 data. However

  4. Efficient sub-Doppler transverse laser cooling of an indium atomic beam

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae-Ihn

    2009-07-23

    Laser cooled atomic gases and atomic beams are widely studied samples in experimental research in atomic and optical physics. For the application of ultra cold gases as model systems for e.g. quantum many particle systems, the atomic species is not very important. Thus this field is dominated by alkaline, earthalkaline elements which are easily accessible with conventional laser sources and have convenient closed cooling transition. On the other hand, laser cooled atoms may also be interesting for technological applications, for instance for the creation of novel materials by atomic nanofabrication (ANF). There it will be important to use technologically relevant materials. As an example, using group III atoms of the periodical table in ANF may open a route to generate fully 3D structured composite materials. The minimal requirement in such an ANF experiment is the collimation of an atomic beam which is accessible by one dimensional laser cooling. In this dissertation, I describe transverse laser cooling of an Indium atomic beam. For efficient laser cooling on a cycling transition, I have built a tunable, continuous-wave coherent ultraviolet source at 326 nm based on frequency tripling. For this purpose, two independent high power Yb-doped fiber amplifiers for the generation of the fundamental radiation at {lambda}{sub {omega}} = 977 nm have been constructed. I have observed sub-Doppler transverse laser cooling of an Indium atomic beam on a cycling transition of In by introducing a polarization gradient in the linear-perpendicular-linear configuration. The transverse velocity spread of a laser-cooled In atomic beam at full width at half maximum was achieved to be 13.5{+-}3.8 cm/s yielding a full divergence of only 0.48 {+-} 0.13 mrad. In addition, nonlinear spectroscopy of a 3-level, {lambda}-type level system driven by a pump and a probe beam has been investigated in order to understand the absorption line shapes used as a frequency reference in a previous two

  5. Passive Two-Phase Cooling of Automotive Power Electronics: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, G.; Jeffers, J. R.; Narumanchi, S.; Bennion, K.

    2014-08-01

    Experiments were conducted to evaluate the use of a passive two-phase cooling strategy as a means of cooling automotive power electronics. The proposed cooling approach utilizes an indirect cooling configuration to alleviate some reliability concerns and to allow the use of conventional power modules. An inverter-scale proof-of-concept cooling system was fabricated, and tests were conducted using the refrigerants hydrofluoroolefin HFO-1234yf and hydrofluorocarbon HFC-245fa. Results demonstrated that the system can dissipate at least 3.5 kW of heat with 250 cm3 of HFC-245fa. An advanced evaporator design that incorporates features to improve performance and reduce size was conceived. Simulation results indicate its thermal resistance can be 37% to 48% lower than automotive dual side cooled power modules. Tests were also conducted to measure the thermal performance of two air-cooled condensers--plain and rifled finned tube designs. The results combined with some analysis were then used to estimate the required condenser size per operating conditions and maximum allowable system (i.e., vapor and liquid) temperatures.

  6. Masking of Time-Frequency Patterns in Applications of Passive Underwater Target Detection

    Directory of Open Access Journals (Sweden)

    Jüri Sildam

    2010-01-01

    Full Text Available Spectrogram analysis of acoustical sounds for underwater target classification is utilized when loud nonstationary interference sources overlap with a signal of interest in time but can be separated in time-frequency (TF domain. We propose a signal masking method which in a TF plane combines local statistical and morphological features of the signal of interest. A dissimilarity measure D of adjacent TF cells is used for local estimation of entropy H, followed by estimation of ΔH=Htc−Hfc entropy difference, where Hfc is calculated along the time axis at a mean frequency fc and Htc is calculated along the frequency axis at a mean time tc of the TF window, respectively. Due to a limited number of points used in ΔH estimation, the number of possible ΔH values, which define a primary mask, is also limited. A secondary mask is defined using morphological operators applied to, for example, H and ΔH. We demonstrate how primary and secondary masks can be used for signal detection and discrimination, respectively. We also show that the proposed approach can be generalized within the framework of Genetic Programming.

  7. 'TEWI' concept for estimation of the global warming from the refrigerating and air conditioning systems

    International Nuclear Information System (INIS)

    Ciconkov, Risto

    2002-01-01

    The most applied CFC refrigerants and their HFC alternatives. values of ODP (Ozone Depletion Potential) and GWP (Global Warming Potential) of the most used refrigerants. natural working fluids and their properties. Montreal Protocol and Kyoto Protocol, illogical relations between them concerning to the HFC fluids. Confusion and polemics on the international level about the appliance of HFCs which, by the Kyoto Protocol, are liable to reduction. Introduction of the TEWI concept as a method for estimating the overall influence of refrigerating and air conditioning systems on the greenhouse effect: the direct emission (refrigerant leakage in the atmosphere) and indirect emission as a result of the electrical energy consumption. A demonstration of the TEWI concept on the concrete example in several variants. A discussion about the appliance of the TEWI concept. Meaning of the energy efficiency of the refrigerating systems (indirect CO 2 emission). One of the main measures: prevention of refrigerant leakage (direct CO 2 emission). A need of permanent education and training courses of the people who work on refrigerating and air conditioning systems. A necessity for constitution of an expert body in the country, preparation of a strategy to lay obligations on the new changes of the Kyoto Protocol and news on the world market. Introduction of country regulations, certification of the companies and people involved in refrigeration and air conditioning. (Author)

  8. Investigational report on the trend of measures for global warming; Chikyu ondanka taisaku doko chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    To know the trend of measures taken for global warming, conducted were overseas surveys, participation in academic society meetings, and literature surveys. The phaseout time of all ozone depleting substances responsible for the ozonospherial destruction was determined for both developed and developing countries in the 7th Meeting of countries which concluded the Montreal Protocol. As information on measures for protecting the ozonosphere, introduced was activities under United Nations Environment Programme (UNEP). New fluorine containing ethers were introduced as cleaning solvent which causes no ozonospherial destruction and is low in global warming index. Toxicity data were obtained on HFC-236ea and HFC-236fa which are promising substitutes in HCFC foaming and refrigerant fields. The paper introduced an outline of the 1st Meeting of countries which concluded the Framework Convention on Climate Change held in 1995. According to the report on the National Institute of Public Health and Environmental Protection of the Netherlands, the amount of emission of fluorine containing greenhouse effect gas (in CO2 conversion) reached 8-14% of all the amount of greenhouse effect gas emitted in 1990 unless the control is reinforced. An outline of the TEWI-3 project was introduced which is useful for comparing effects of substitution technologies on global warming. 14 refs., 11 figs., 29 tabs.

  9. Glucuronidation of trans-resveratrol by human liver and intestinal microsomes and UGT isoforms.

    Science.gov (United States)

    Brill, Shirley S; Furimsky, Anna M; Ho, Mark N; Furniss, Michael J; Li, Yi; Green, Adam G; Bradford, Wallace W; Green, Carol E; Kapetanovic, Izet M; Iyer, Lalitha V

    2006-04-01

    Resveratrol (trans-resveratrol, trans-3,5,4'-trihydroxystilbene) is a naturally occurring stilbene analogue found in high concentrations in red wine. There is considerable research interest to determine the therapeutic potential of resveratrol, as it has been shown to have tumour inhibitory and antioxidant properties. This study was performed to investigate the glucuronidation of resveratrol and possible drug interactions via glucuronidation. Two glucuronide conjugates, resveratrol 3-O-glucuronide and resveratrol 4'-O-glucuronide, were formed by human liver and intestinal microsomes. UGT1A1 and UGT1A9 were predominantly responsible for the formation of the 3-O-glucuronide (Km = 149 microM) and 4'-O-glucuronide (Km = 365 microM), respectively. The glucuronide conjugates were formed at higher levels (up to 10-fold) by intestinal rather than liver microsomes. Resveratrol was co-incubated with substrates of UGT1A1 (bilirubin and 7-ethyl-10-hydroxycamptothecin (SN-38)) and UGT1A9 (7-hydroxytrifluoromethyl coumarin (7-HFC)). No major changes were noted in bilirubin glucuronidation in the presence of resveratrol. Resveratrol significantly inhibited the glucuronidation of SN-38 (Ki = 6.2 +/- 2.1 microM) and 7-HFC (Ki = 0.6 +/- 0.2 microM). Hence, resveratrol has the potential to inhibit the glucuronidation of concomitantly administered therapeutic drugs or dietary components that are substrates of UGT1A1 and UGT1A9.

  10. European Union-Emission Trading Scheme: outlook for the chemical industry

    International Nuclear Information System (INIS)

    Coussy, P.; Alberola, E.

    2013-01-01

    From 2013, under the European Union Emissions Trading Scheme (EU-ETS), Europe will cap its emissions of nitrous oxide (N 2 O) and per-fluorocarbons (PFC) from the chemical industry. Besides, 336 chemical industry facilities will be forced to limit their emissions at 45.8 million tons of CO 2 per year from 2013 to 2020. At date August 1, 2012, almost 70% of the carbon credits issued by the clean development mechanism (CDM) were carried out mainly through the destruction of hydro-fluorocarbons (HFC-23) (42%) and N 2 O (22%). The contribution of emission reductions through chemical processes in the Joint Implementation (JI) projects is smaller but still amounted to 32% of all projects. From 1 May 2013 the European Union will refuse CDM and JI credits from emission reductions of HFC-23 and N 2 O. The issues of the introduction of the chemical industry in the EU-ETS in the context of low CO 2 prices and limited validity of CDM and JI chemical projects are high. Therefore, domestic CO 2 emissions reductions from energy consumption of the chemistry sector will take a larger share. (authors)

  11. Final report on CCQM-P151: Halocarbons in dry whole air

    Science.gov (United States)

    Rhoderick, George; Guenther, Franklin; Duewer, David; Lee, Jeongsoon; Seog Kim, Jin; Hall, Bradley; Weiss, Ray; Harth, Christina; Reimann, Stefan; Vollmer, Martin

    2014-01-01

    The growing awareness of climate change/global warming and continuing concerns regarding stratospheric ozone depletion will require future measurements and standards for many compounds, in particular halocarbons that are linked to these issues. In order to track and control the emissions of these species globally in the atmosphere, it is necessary to demonstrate measurement equivalence at the highest levels of accuracy for assigned values of standards. This report describes the results of a pilot study between National Metrology Institutes and atmospheric research laboratories for several of the more important halocarbons at atmospheric concentration levels. The comparison includes the chlorofluorocarbons (CFCs) dichlorodifluoromethane (CFC 12), trichlorofluoromethane (CFC 11), and 1,1,2-trichlorotrifluoroethane (CFC 113); the hydrochlorofluorocarbons (HCFCs) chlorodifluoromethane (HCFC 22) and 1-chloro-1,1-difluoroethane (HCFC 142b); and the hydrofluorocarbon (HFC) 1,1,1,2-tetrafluoroethane (HFC 134a), all in a dried whole air sample. The objective of this key comparison is to compare the measurement capabilities of the participants for these halocarbons at trace atmospheric levels. Main text. To reach the main text of this paper, click on Final Report. The final report has been peer-reviewed and approved for publication by the CCQM.

  12. Comparison of halocarbon measurements in an atmospheric dry whole air sample.

    Science.gov (United States)

    Rhoderick, George C; Hall, Bradley D; Harth, Christina M; Kim, Jin Seog; Lee, Jeongsoon; Montzka, Stephen A; Mühle, Jens; Reimann, Stefan; Vollmer, Martin K; Weiss, Ray F

    The growing awareness of climate change/global warming, and continuing concerns regarding stratospheric ozone depletion, will require continued measurements and standards for many compounds, in particular halocarbons that are linked to these issues. In order to track atmospheric mole fractions and assess the impact of policy on emission rates, it is necessary to demonstrate measurement equivalence at the highest levels of accuracy for assigned values of standards. Precise measurements of these species aid in determining small changes in their atmospheric abundance. A common source of standards/scales and/or well-documented agreement of different scales used to calibrate the measurement instrumentation are key to understanding many sets of data reported by researchers. This report describes the results of a comparison study among National Metrology Institutes and atmospheric research laboratories for the chlorofluorocarbons (CFCs) dichlorodifluoromethane (CFC-12), trichlorofluoromethane (CFC-11), and 1,1,2-trichlorotrifluoroethane (CFC-113); the hydrochlorofluorocarbons (HCFCs) chlorodifluoromethane (HCFC-22) and 1-chloro-1,1-difluoroethane (HCFC-142b); and the hydrofluorocarbon (HFC) 1,1,1,2-tetrafluoroethane (HFC-134a), all in a dried whole air sample. The objective of this study is to compare calibration standards/scales and the measurement capabilities of the participants for these halocarbons at trace atmospheric levels. The results of this study show agreement among four independent calibration scales to better than 2.5% in almost all cases, with many of the reported agreements being better than 1.0%.

  13. Final report on international comparison CCQM-K83: Halocarbons in dry whole air

    Science.gov (United States)

    Rhoderick, George; Guenther, Franklin; Duewer, David; Lee, Jeongsoon; Moon, Dongmin; Lee, Jinbok; Lim, Jeongsik; Seog Kim, Jin

    2014-01-01

    The growing awareness of climate change/global warming and continuing concerns regarding stratospheric ozone depletion will require future measurements and standards for many compounds, in particular halocarbons that are linked to these issues. In order to track and control the emissions of these species globally in the atmosphere, it is necessary to demonstrate measurement equivalence at the highest levels of accuracy for assigned values of standards. This report describes the results of a key comparison for several of the more important halocarbons at atmospheric concentration levels. The comparison includes the chlorofluorocarbons (CFCs) dichlorodifluoromethane (CFC 12), trichlorofluoromethane (CFC 11), and 1,1,2 trichlorotrifluoroethane (CFC 113); the hydrochlorofluorocarbons (HCFCs) chlorodifluoromethane (HCFC 22) and 1-chloro-1,1-difluoroethane (HCFC 142b); and the hydrofluorocarbon (HFC) 1,1,1,2 tetrafluoroethane (HFC 134a), all in a dried whole air sample. The objective of this key comparison is to compare the measurement capabilities of the participants for these halocarbons at trace atmospheric levels. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  14. Calculated trends and the atmospheric abundance of 1,1,1,2-tetrafluoroethane, 1,1-dichloro-1-fluoroethane, and 1-chloro-1,1-difluoroethane using automated in-situ gas chromatography-mass spectrometry measurements recorded at Mace Head, Ireland, from October 1994 to March 1997

    Science.gov (United States)

    Simmonds, P. G.; O'Doherty, S.; Huang, J.; Prinn, R.; Derwent, R. G.; Ryall, D.; Nickless, G.; Cunnold, D.

    1998-01-01

    The first in-situ measurements by automated gas chromatograph-mass spectrometer are reported for 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1-dichloro-1-fluoroethane, (HCFC-141b), and 1-chloro-1,1-difluoroethane, (HCFC-142b). These compounds are steadily replacing the chlorofluorocarbons (CFCs) as refrigerants, foam-blowing agents, and solvents. The concentrations of all three compounds are shown to be rapidly increasing in the atmosphere, with 134a increasing at a rate of 2.05±0.02 ppt yr-1 over the 30 months of observations. Similarly, 141b and 142b increased at rates of 2.49±0.03 and 1.24±0.02 ppt yr-1, respectively, over the same period. The concentrations recorded at the atmospheric research station at Mace Head, Ireland, on January 1, 1996, the midpoint of the time series, were 3.67 ppt (134a), 7.38 ppt (141b), and 8.78 ppt (142b). From these observations we optimally estimate the HCFC and HFC emissions using a 12-box global model and OH concentrations derived from global 1,1,1-trichloroethane (CCl3CH3) measurements. Comparing two methods of estimating emissions with independent industry estimates shows satisfactory agreement for 134a and 141b, while for 142b, industry estimates are less than half those required to explain our observations.

  15. Burning velocity measurements of nitrogen-containing compounds.

    Science.gov (United States)

    Takizawa, Kenji; Takahashi, Akifumi; Tokuhashi, Kazuaki; Kondo, Shigeo; Sekiya, Akira

    2008-06-30

    Burning velocity measurements of nitrogen-containing compounds, i.e., ammonia (NH3), methylamine (CH3NH2), ethylamine (C2H5NH2), and propylamine (C3H7NH2), were carried out to assess the flammability of potential natural refrigerants. The spherical-vessel (SV) method was used to measure the burning velocity over a wide range of sample and air concentrations. In addition, flame propagation was directly observed by the schlieren photography method, which showed that the spherical flame model was applicable to flames with a burning velocity higher than approximately 5 cm s(-1). For CH3NH2, the nozzle burner method was also used to confirm the validity of the results obtained by closed vessel methods. We obtained maximum burning velocities (Su0,max) of 7.2, 24.7, 26.9, and 28.3 cm s(-1) for NH3, CH3NH2, C2H5NH2, and C3H7NH2, respectively. It was noted that the burning velocities of NH3 and CH3NH2 were as high as those of the typical hydrofluorocarbon refrigerants difluoromethane (HFC-32, Su0,max=6.7 cm s(-1)) and 1,1-difluoroethane (HFC-152a, Su0,max=23.6 cm s(-1)), respectively. The burning velocities were compared with those of the parent alkanes, and it was found that introducing an NH2 group into hydrocarbon molecules decreases their burning velocity.

  16. Comparison of halocarbon measurements in an atmospheric dry whole air sample

    Directory of Open Access Journals (Sweden)

    George C. Rhoderick

    2015-11-01

    Full Text Available Abstract The growing awareness of climate change/global warming, and continuing concerns regarding stratospheric ozone depletion, will require continued measurements and standards for many compounds, in particular halocarbons that are linked to these issues. In order to track atmospheric mole fractions and assess the impact of policy on emission rates, it is necessary to demonstrate measurement equivalence at the highest levels of accuracy for assigned values of standards. Precise measurements of these species aid in determining small changes in their atmospheric abundance. A common source of standards/scales and/or well-documented agreement of different scales used to calibrate the measurement instrumentation are key to understanding many sets of data reported by researchers. This report describes the results of a comparison study among National Metrology Institutes and atmospheric research laboratories for the chlorofluorocarbons (CFCs dichlorodifluoromethane (CFC-12, trichlorofluoromethane (CFC-11, and 1,1,2-trichlorotrifluoroethane (CFC-113; the hydrochlorofluorocarbons (HCFCs chlorodifluoromethane (HCFC-22 and 1-chloro-1,1-difluoroethane (HCFC-142b; and the hydrofluorocarbon (HFC 1,1,1,2-tetrafluoroethane (HFC-134a, all in a dried whole air sample. The objective of this study is to compare calibration standards/scales and the measurement capabilities of the participants for these halocarbons at trace atmospheric levels. The results of this study show agreement among four independent calibration scales to better than 2.5% in almost all cases, with many of the reported agreements being better than 1.0%.

  17. Inlet Flow Control and Prediction Technologies for Embedded Propulsion Systems

    Science.gov (United States)

    McMillan, Michelle L.; Mackie, Scott A.; Gissen, Abe; Vukasinovic, Bojan; Lakebrink, Matthew T.; Glezer, Ari; Mani, Mori; Mace, James L.

    2011-01-01

    Fail-safe, hybrid, flow control (HFC) is a promising technology for meeting high-speed cruise efficiency, low-noise signature, and reduced fuel-burn goals for future, Hybrid-Wing-Body (HWB) aircraft with embedded engines. This report details the development of HFC technology that enables improved inlet performance in HWB vehicles with highly integrated inlets and embedded engines without adversely affecting vehicle performance. In addition, new test techniques for evaluating Boundary-Layer-Ingesting (BLI)-inlet flow-control technologies developed and demonstrated through this program are documented, including the ability to generate a BLI-like inlet-entrance flow in a direct-connect, wind-tunnel facility, as well as, the use of D-optimal, statistically designed experiments to optimize test efficiency and enable interpretation of results. Validated improvements in numerical analysis tools and methods accomplished through this program are also documented, including Reynolds-Averaged Navier-Stokes CFD simulations of steady-state flow physics for baseline, BLI-inlet diffuser flow, as well as, that created by flow-control devices. Finally, numerical methods were employed in a ground-breaking attempt to directly simulate dynamic distortion. The advances in inlet technologies and prediction tools will help to meet and exceed "N+2" project goals for future HWB aircraft.

  18. Measuring the effects of visual demand on lateral deviation: a comparison among driver's performance indicators.

    Science.gov (United States)

    Minin, Luca; Benedetto, Simone; Pedrotti, Marco; Re, Alessandra; Tesauri, Francesco

    2012-05-01

    In this study we compare the efficacy of three driver's performance indicators based on lateral deviation in detecting significant on-road performance degradations while interacting with a secondary task: the High Frequency Component of steering wheel (HFC), and two indicators described in ISO/DIS 26022 (2007): the Normative and the Adapted Lane Change Test (LCT). Sixteen participants were asked to perform a simulated lane-change task while interacting, when required, with a visual search task with two levels of difficulty. According to predictions, results showed that the Adapted LCT indicator, taking into consideration individual practices in performing the LCT, succeeded in discriminating between single and dual task conditions. Furthermore, this indicator was also able to detect whether the driver was interacting with an easy or a difficult secondary task. Despite predictions, results did not confirm Normative LCT and HFC to be reliable indicators of performance degradation within the simulated LCT. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  19. The remarkable environmental rebound effect of electric cars: a microeconomic approach.

    Science.gov (United States)

    Font Vivanco, David; Freire-González, Jaume; Kemp, René; van der Voet, Ester

    2014-10-21

    This article presents a stepwise, refined, and practical analytical framework to model the microeconomic environmental rebound effect (ERE) stemming from cost differences of electric cars in terms of changes in multiple life cycle environmental indicators. The analytical framework is based on marginal consumption analysis and hybrid life cycle assessment (LCA). The article makes a novel contribution through a reinterpretation of the traditional rebound effect and methodological refinements. It also provides novel empirical results about the ERE for plug-in hybrid electric (PHE), full-battery electric (FBE), and hydrogen fuel cell (HFC) cars for Europe. The ERE is found to have a remarkable impact on product-level environmental scores. For the PHE car, the ERE causes a marginal increase in demand and environmental pressures due to a small decrease in the cost of using this technology. For FBE and HFC cars, the high capital costs cause a noteworthy decrease in environmental pressures for some indicators (negative rebound effect). The results corroborate the concern over the high influence of cost differences for environmental assessment, and they prompt sustainable consumption policies to consider markets and prices as tools rather than as an immutable background.

  20. Formation of Al2O3-HfO2 Eutectic EBC Film on Silicon Carbide Substrate

    Directory of Open Access Journals (Sweden)

    Kyosuke Seya

    2015-01-01

    Full Text Available The formation mechanism of Al2O3-HfO2 eutectic structure, the preparation method, and the formation mechanism of the eutectic EBC layer on the silicon carbide substrate are summarized. Al2O3-HfO2 eutectic EBC film is prepared by optical zone melting method on the silicon carbide substrate. At high temperature, a small amount of silicon carbide decomposed into silicon and carbon. The components of Al2O3 and HfO2 in molten phase also react with the free carbon. The Al2O3 phase reacts with free carbon and vapor species of AlO phase is formed. The composition of the molten phase becomes HfO2 rich from the eutectic composition. HfO2 phase also reacts with the free carbon and HfC phase is formed on the silicon carbide substrate; then a high density intermediate layer is formed. The adhesion between the intermediate layer and the substrate is excellent by an anchor effect. When the solidification process finished before all of HfO2 phase is reduced to HfC phase, HfC-HfO2 functionally graded layer is formed on the silicon carbide substrate and the Al2O3-HfO2 eutectic structure grows from the top of the intermediate layer.

  1. A new method used to evaluate organic working fluids

    International Nuclear Information System (INIS)

    Zhang, Xinxin; He, Maogang; Wang, Jingfu

    2014-01-01

    In this paper, we propose a method named “Weight Classification-Hasse Dominance” to evaluate organic working fluids. This new method combines the advantages of both the method of weight determination and the Hasse Diagram Technique (HDT). It can be used to evaluate the thermodynamic performance, environmental protection indicator, and safety requirement of organic working fluid simultaneously. This evaluation method can offer good reference for working fluid selection. Using this method, the organic working fluids which have been phased out and will be phased out by the Montreal Protocol including CFCs (chlorofluorocarbons), HCFCs (hydrochlorofluorocarbons), and HFCs (hydrofluorocarbons) were evaluated. Moreover, HCs (hydrocarbons) can be considered as a completely different kind of organic working fluid from CFCs, HCFCs, and HFCs according to the comparison based on this new evaluation method. - Highlights: • We propose a new method used to evaluate organic working fluids. • This evaluation method can offer good reference for working fluid selection. • CFC, HCFC, and HFC working fluids were evaluated using this evaluation method. • HC can be considered as a totally different working fluid from CFC, HCFC, and HFC

  2. The LiveWire Project final report

    Energy Technology Data Exchange (ETDEWEB)

    Brown, C.D.; Nelson, T.T. [Enova Technology, San Diego, CA (United States); Kelly, J.C.; Dominguez, H.A. [Paragon Consulting Services, La Verne, CA (United States)

    1997-10-01

    Utilities across the US have begun pilot testing a variety of hardware and software products to develop a two-way communications system between themselves and their customers. Their purpose is to reduce utility operating costs and to provide new and improved services for customers in light of pending changes in the electric industry being brought about by deregulation. A consortium including utilities, national labs, consultants, and contractors, with the support of the Department of Energy (DOE) and the Electric Power Research Institute (EPRI), initiated a project that utilized a hybrid fiber-coax (HFC) wide-area network integrated with a CEBus based local area network within the customers home. The system combined energy consumption data taken within the home, and home automation features to provide a suite of energy management services for residential customers. The information was transferred via the Internet through the HFC network, and presented to the customer on their personal computer. This final project report discusses the design, prototype testing, and system deployment planning of the energy management system.

  3. Human factors research in Central Research Institute of Electric Power Industry creation of safety culture

    International Nuclear Information System (INIS)

    Horie, Yasuo

    2002-01-01

    To prevent accident of nuclear power plant, Human Factors Center was built in the Central Research Institute of Electric Power Industry in July 1987. It developed an evaluation method of human error cases and an application method of human factors information. Now it continues analysis and application of human factors information, development of training/work support tools and research/experiment of human behavior. Japan-Human Performance Evaluation System (J-HPES) was developed as an analytical system for analysis and evaluation of human factors related to the trouble and for using the result as the common property by storage the analytical results. J-HPES has a standard procedure consisted of collecting and analyzing data and proposing the countermeasures. The analytical results are arranged by 4 kinds of charts by putting into the form of a diagram. Moreover, it tries to find the causes with indirect and potential causes. Two kinds of materials, Caution Report and Human Factors Precept by means of Illustrations, are published. People can gain access to HFC database by URL http://criepi.denken.or.jp/CRIEPI/HFC/DB. To prevent these accidents, creation of human factors culture has been required. Five kinds of teaching materials and the training method are developed. (S.Y.)

  4. Shear viscosity of binary mixtures: The Gay–Berne potential

    International Nuclear Information System (INIS)

    Khordad, R.

    2012-01-01

    Highlights: ► Most useful potential model to study the real systems is the Gay–Berne (GB) potential. ► We use GB model to examine thermodynamical properties of some anisotropic binary mixtures in two different phases. ► The integral equation methods are applied to solve numerically the Percus–Yevick (PY) equation. ► We obtain expansion coefficients of correlation functions needed to calculate the properties of studied mixtures. ► The results are compared with the available experimental data [e.g., HFC-125 + propane, R-125/143a, methanol + toluene, etc.] - Abstract: The Gay–Berne (GB) potential model is an interesting and useful model to study the real systems. Using the potential model, we intend to examine the thermodynamical properties of some anisotropic binary mixtures in two different phases, liquid and gas. For this purpose, we apply the integral equation method and solve numerically the Percus–Yevick (PY) integral equation. Then, we obtain the expansion coefficients of correlation functions to calculate the thermodynamical properties. Finally, we compare our results with the available experimental data [e.g., HFC-125 + propane, R-125/143a, methanol + toluene, benzene + methanol, cyclohexane + ethanol, benzene + ethanol, carbon tetrachloride + ethyl acetate, and methanol + ethanol]. The results show that the GB potential model is capable for predicting the thermodynamical properties of binary mixtures with acceptable accuracy.

  5. Fluoride production in RPCs operated with F-compound gases

    International Nuclear Information System (INIS)

    Aielli, G.; Camarri, P.; Cardarelli, R.; Di Ciaccio, A.; Di Simone, A.; Liberti, B.; Palummo, L.; Santonico, R.

    2006-01-01

    The Resistive Plate Chambers (RPC) are gaseous detectors widely used in LCH experiments for muon trigger systems and time of flight measurement due to their very good time resolution. Gas mixtures with a prevalence of HFC components are generally adjoint used to achieve a lower charge per count an consequently an higher rate capability. The decomposition of HFC under electrical discharge produces a significant concentration of fluorine ions F - that can be detected in the RPC exhausted gas. Due to the high chemical reactivity, this pollutant represents a possible cause of the inner surface damaging if it not quickly removed by the gas flow. In this paper various aspects of this phenomenology are investigated. We measured the F - production rate as a function of the detector counting rate and the working point (both in streamer and avalanche mode). The effect of the addition of 0.5% of SF 6 to the test mixture is also shown. We also extensively investigated the ratio between the F - production associated to a the time integral of the working current

  6. Preparation, structure and properties of hafnium compounds in the system Hf-C-N-O

    International Nuclear Information System (INIS)

    Brundiers, G.D.

    1975-08-01

    Highly dense, homogenous and single phase hafnium carbonitride samples (with low oxygen content) were prepared in the whole concentration range of the ternary cubic carbonitrides. Stoichiometric hafnium oxicarbides were also prepared within the range of solubility. The procedure involved the hot pressing of powders of HfC, HfN, Hf, Hf-Oxide and carbon at temperatures of 3,000 0 C and pressures up to 550 kpf/cm 2 using a novel technique. Small single crystals of slightly substoichiometric HfN were also repared. The densification of the powders was studied as a function of the non-metal concentration. Carbonitrides with N/Hf ratio of 0.37 were prepared in a high temperature autoclave operating at medium pressures by the reaction of HfC with nitrogen. All the samples were characterized by density measurements, chemical, X-ray and metallographic analysis and in some cases with the aid of quantitative metallography and microprobe analysis. Typical properties investigated were lattice parameter, thermal expansion, microhardness and electrical resistivity as function of the non-metal content. For specific concentrations extreme values in the properties are attained. With the aid of the valence electron concentration (VEC) parameter, the properties can be correlated with the density of states of electrons at the Fermi level. (orig./HK) [de

  7. Energy consumption estimation for greenhouse gas separation processes by clathrate hydrate formation

    International Nuclear Information System (INIS)

    Tajima, Hideo; Yamasaki, Akihiro; Kiyono, Fumio

    2004-01-01

    The process energy consumption was estimated for gas separation processes by the formation of clathrate hydrates. The separation process is based on the equilibrium partition of the components between the gaseous phase and the hydrate phase. The separation and capturing processes of greenhouse gases were examined in this study. The target components were hydrofluorocarbon (HFC-134a) from air, sulfur hexafluoride (SF 6 ) from nitrogen, and CO 2 from flue gas. Since these greenhouse gases would form hydrates under much lower pressure and higher temperature conditions than the accompanying components, the effective capturing of the greenhouse gases could be achieved by using hydrate formation. A model separation process for each gaseous mixture was designed from the basis of thermodynamics, and the process energy consumption was estimated. The obtained results were then compared with those for conventional separation processes such as liquefaction separation processes. For the recovery of SF 6 , the hydrate process is preferable to liquefaction process in terms of energy consumption. On the other hand, the liquefaction process consumes less energy than the hydrate process for the recovery of HFC-134a. The capturing of CO 2 by the hydrate process from a flue gas will consume a considerable amount of energy; mainly due to the extremely high pressure conditions required for hydrate formation. The influences of the operation conditions on the heat of hydrate formation were elucidated by sensitivity analysis. The hydrate processes for separating these greenhouse gases were evaluated in terms of reduction of global warming potential (GWP)

  8. Polyalkylene glycols, base fluids for special lubricants and hydraulic fluids; Polyalkylenglykole, Basisoele fuer Spezialschmierstoffe und Hydraulikfluessigkeiten

    Energy Technology Data Exchange (ETDEWEB)

    Poellmann, K. [Clariant GmbH (Germany)

    2004-08-01

    For many years polyalkylene glycols have been used as base fluids for special lubricants. In this matter they compete with polyol esters and polyalphaolefines. Synthesis of polyalkylen glycols is founded upon the anionic polymerisation of ethyleneoxid, propyleneoxid and if necessary of other oxigen-containing monomeres. The flexibility of this synthesis is the reason that polyalkylene glycole is a collective term, including a broad group of base fluids with partly extreme different properties. Typical for polyalkylene glycols is a high viscosity-index, watersolubility and adsorbing power for water, low friction numbers, but also the incompatibility with current mineral-oil-soluble additive systems. Because of this quality profile there has been developped specific niche-applications in the lubricant-area for polyalkylene glycols in the last 30 years, where each of the specific benefits has been used. Among them are watercontaining HFC hydraulicfluids, refrigerator oils, and oils for ethylene-compressors. HFC fluids are formulated with high-viscous, water-soluble polyalkylene glycols. For refrigerator oils in motor-car conditioning the R 134A compatibility of water-insoluble polyalkylene glycols is essential. For the use in ethylene-compressors the crucial point is the insolubility of polyalkylene glycol in ethylene. (orig.)

  9. Condensation heat transfer coefficients of flammable refrigerants on various enhanced tubes

    International Nuclear Information System (INIS)

    Park, Ki Jung; Jung, Dong Soo

    2005-01-01

    In this study, external condensation Heat Transfer Coefficients (HTCs) of six flammable refrigerants of propylene (R1270), propane (R290), isobutane (R600a), butane (R600), dimethylether (RE170), and HFC32 were measured at the vapor temperature of 39 .deg. C on a 1023 fpm low fin and turbo-C tubes. All data were taken under the heat flux of 32∼116 and 42∼142 kW/m 2 for the low fin and turbo-C tubes respectively. Flammable refrigerants' data obtained on enhanced tubes showed a typical trend that external condensation HTCs decrease with increasing wall subcooling. HFC32 and DME showed up to 30% higher HTCs than those of HCFC22 due to their excellent thermophysical properties. Propylene, propane, isobutane, and butane showed similar or lower HTCs than those of HCFC22. Beatty and Katz' correlation predicted the HTCs of the flammable refrigerants obtained on a low fin tube within a mean deviation of 7.3%. Turbo-C tube showed the best performance due to its 3 dimensional surface geometry for fast removal of condensate

  10. Comparison of halocarbon measurements in an atmospheric dry whole air sample

    Science.gov (United States)

    Hall, Bradley D.; Harth, Christina M.; Kim, Jin Seog; Lee, Jeongsoon; Montzka, Stephen A.; Mühle, Jens; Reimann, Stefan; Vollmer, Martin K.; Weiss, Ray F.

    2015-01-01

    The growing awareness of climate change/global warming, and continuing concerns regarding stratospheric ozone depletion, will require continued measurements and standards for many compounds, in particular halocarbons that are linked to these issues. In order to track atmospheric mole fractions and assess the impact of policy on emission rates, it is necessary to demonstrate measurement equivalence at the highest levels of accuracy for assigned values of standards. Precise measurements of these species aid in determining small changes in their atmospheric abundance. A common source of standards/scales and/or well-documented agreement of different scales used to calibrate the measurement instrumentation are key to understanding many sets of data reported by researchers. This report describes the results of a comparison study among National Metrology Institutes and atmospheric research laboratories for the chlorofluorocarbons (CFCs) dichlorodifluoromethane (CFC-12), trichlorofluoromethane (CFC-11), and 1,1,2-trichlorotrifluoroethane (CFC-113); the hydrochlorofluorocarbons (HCFCs) chlorodifluoromethane (HCFC-22) and 1-chloro-1,1-difluoroethane (HCFC-142b); and the hydrofluorocarbon (HFC) 1,1,1,2-tetrafluoroethane (HFC-134a), all in a dried whole air sample. The objective of this study is to compare calibration standards/scales and the measurement capabilities of the participants for these halocarbons at trace atmospheric levels. The results of this study show agreement among four independent calibration scales to better than 2.5% in almost all cases, with many of the reported agreements being better than 1.0%. PMID:26753167

  11. Persistence of sister chromatid exchanges and in vitro morphological transformation of Syrian hamster fetal cells by chemical and physical carcinogens

    International Nuclear Information System (INIS)

    Popescu, N.C.; Amsbaugh, S.C.; DiPaolo, J.A.

    1985-01-01

    The induction of neoplastic cell transformation is closely associated with DNA alterations which occur shortly after carcinogen exposure. Sister chromatid exchange (SCE) formation is a sensitive indicator of carcinogen-DNA interaction and correlates with the induction of morphological cell transformation. The persistence of lesions generating SCE produced by chemical and physical carcinogens and its relevance to the induction of morphologic transformation was evaluated in coordinated experiments with cultured Syrian hamster fetal cells (HFC). Exponentially growing HFC were exposed for 1 h to benzo[a]pyrene (BP), methyl-methanesulfonate (MMS), cis-platinum (II) diaminedichloride (cis Pt II), N-methyl-N'-nitrosourea (MNU), mitomycin C (MMC), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), N-acetoxy-2-fluorenyl-acetamide (AcAAF) or u.v. light irradiated. SCE analysis demonstrates that for a period of 48 h after carcinogen exposure, during which time the cells undergo at least four replicative cycles, DNA damage generating SCE induced by all chemical carcinogens either persisted or was partially removed, whereas u.v.-induced lesions were completely removed. An elevated SCE frequency persisted after two additional cell cycles after treatment with BP, AcAAF or MMC without increased cell lethality as compared to other carcinogens whose lesions were completely eliminated during the same period

  12. Dark chocolate consumption improves leukocyte adhesion factors and vascular function in overweight men.

    Science.gov (United States)

    Esser, Diederik; Mars, Monica; Oosterink, Els; Stalmach, Angelique; Müller, Michael; Afman, Lydia A

    2014-03-01

    Flavanol-enriched chocolate consumption increases endothelium-dependent vasodilation. Most research so far has focused on flow-mediated dilation (FMD) only; the effects on other factors relevant to endothelial health, such as inflammation and leukocyte adhesion, have hardly been addressed. We investigated whether consumption of regular dark chocolate also affects other markers of endothelial health, and whether chocolate enrichment with flavanols has additional benefits. In a randomized double-blind crossover study, the effects of acute and of 4 wk daily consumption of high flavanol chocolate (HFC) and normal flavanol chocolate (NFC) on FMD, augmentation index (AIX), leukocyte count, plasma cytokines, and leukocyte cell surface molecules in overweight men (age 45-70 yr) were investigated. Sensory profiles and motivation scores to eat chocolate were also collected. Findings showed that a 4 wk chocolate intake increased FMD by 1%, which was paralleled by a decreased AIX of 1%, decreased leukocyte cell count, decreased plasma sICAM1 and sICAM3, and decreased leukocyte adhesion marker expression (Peffect), with no difference between HFC and NFC consumption. Flavanol enrichment did affect taste and negatively affected motivation to consume chocolate. This study provides new insights on how chocolate affects endothelial health by demonstrating that chocolate consumption, besides improving vascular function, also lowers the adherence capacity of leukocytes in the circulation.

  13. Moving from the CDM to 'various approaches'

    International Nuclear Information System (INIS)

    Shishlov, Igor; Bellassen, Valentin

    2014-03-01

    The Clean Development Mechanism (CDM) facilitated the emergence and deployment of low-cost greenhouse gas (GHG) abatement technologies such as destruction of industrial gases and capturing methane from landfills and coal mines. Some of these technologies are now ripe to 'graduate' from the CDM into other, more mainstream, economic tools. The first such step was taken in September 2013 when the G20 leaders agreed to phase out HFCs - highly potent greenhouse gases - including HFC-23 that was the focus of 19 CDM projects. A potential HFC-23 abatement fund under the Montreal Protocol could reduce up to 1.8 Gt CO 2 e by 2020 at a cost of under US$0.2 per ton of CO 2 e, i.e. much cheaper than the price paid to CDM projects through carbon crediting. The next potential candidate technology to 'graduate' from the CDM is the abatement of nitrous oxide (N 2 O) emissions in the chemical industry, which have already been placed on the agenda of the Montreal Protocol. (authors)

  14. Process and quality control in manufacturing of nuclear fuel assemblies of LWRs

    International Nuclear Information System (INIS)

    Dietrich, M.; Hoff, A.; Reimann, P.

    2000-01-01

    Manufacturing of nuclear fuel assemblies requires a multitude of different process and quality methods to assure and maintain a high quality level. In recent years methods have been applied which prevent deviations rather than detect deviant products. This paper gives an example on how to control a complex manufacturing process by using a small number of key parameters and second, it demonstrates the importance of graphical data evaluation and presentation methods. In the past many product and product characteristics were inspected m comparison with specification limits only. However, todays methods allow the early identification of trends, increase of variation, shifts disturbances etc. before the product characteristics exceed the specification limits. These methods are process control charts, x-y-plots, boxplots, failure mode and effect analysis (FMEA), process capability numbers and others. This paper demonstrates the beneficial use of some of the methods by presenting selected examples applied at Advanced Nuclear Fuels GmbH (ANF). (author)

  15. Fahrstuhlfahrten und Einstiegsschwierigkeiten. Erschließungstechniken in Georges Perecs »La Vie mode d’emploi«

    Directory of Open Access Journals (Sweden)

    Johanne Mohs

    2014-05-01

    Full Text Available Der Artikel ist eine produktionsästhetische Untersuchung zu Einstiegsschwierigkeiten in literarische Schreibprozesse und ihre Auflösung mithilfe räumlicher und sprachspielerischer Erschließungstechniken. Als Beispiel dient mir die Poetik des OuLiPo (»Ouvroir de littérature potentielle« und hier insbesondere (die Genese von Georges Perecs Roman »La vie mode d’emploi«. Genauer wird daran gezeigt, wie Perec eine blockierte Fahrstuhlfahrt als metaphorische Referenz auf seine anfängliche Schreibhemmung in den Roman einfügt und wie diese Referenz als Kommentar zur Erzählbarkeit komplexer Raum-Zeit-Gefüge im Gesellschaftsroman des 20. Jahrhunderts, insbesondere zu Marcel Prousts »Recherche«, verstanden werden kann.

  16. Lankesterella alencari n. sp., a toxoplasma-like organism in the central nervous system of Amphibia (Protozoa, Sporozoa Lankesterella alencari n. sp., um toxoplasma-like no sistema nervoso central de Amphibia (Protozoa, Sporozoa

    Directory of Open Access Journals (Sweden)

    Sylvio Celso Gonçalves da Costa

    1971-01-01

    Full Text Available Lankesterella alencari n. sp. a Sporozoa that occur in the blood and CNS of the South American frog Leptodactylus acellatus is described. Since the tissue forms of this parasite have been previously reported as belonging to the genus Toxoplasma, we attempted in fection of 2 species of amphibia (Bufo marinus an dLeptodactylus ocellatus with a Toxoplasma strain of human origen; inoculation was by intraperitoneal injection of parasite-containing ascitic fluid from infected mice. Attempt of experimental inoculation of the parasite found in the CNS of L. ocellatus in a highly susceptible host (mice was unsuccessful. These results suggest that Toxoplasma does not occur naturally in the amphibia; be related to Toxoplasma is excluded. The following genera of haematozoa found in brazilian amphibia have been considered briedfly: Haemobartonella, Cytamoeba, Dactylosoma, Hepatozoon and Trypanosoma.Os autores descrevem uma espécie do gênero Lankesterella considerada nova para a ciência, que ocorre com certa freqüência parasitando a rã Leptodactylus ocellatus no Brasil. Como os cistos dêste parasito, encontrados no SNC, foram anteriormente relacionados ao gênero Toxoplasma por outro autor, realizamos uma série de inoculações experimentais para eliminar a hipótese. Tanto as inoculações com amostra de Toxoplasma gondii de origem humana em anfíbios, como as de mascerados de SNC de rã contendo cistos em camundongos, foram negativas. As inoculações de T. gondii em anfíbios foram realizadas em temperatura ambiente que no Rio de Janeiro, na época era 30º-39ºC. Não encontramos, por outro lado, cistos no SNC de anfíbios do gênero Bufo, fato assinalado por outros autores. Realizamos algumas técnicas citoquímicas para melhor caracterização do parasito. Tendo em vista o grande número de hemoparasitos encontrados nas rãs brasileiras e as infecções múltiplas ocorrerem com freqüência, apresentamos também a incidência dêstes parasitos

  17. Abundance, distribution and feeding patterns of a temperate reef fish in subtidal environments of the Chilean coast: the importance of understory algal turf Abundancia, distribución y patrones alimentarios de un pez de arrecifes templados en ambientes submareales de la costa de Chile: la importancia de la capa de algas del subdosel

    Directory of Open Access Journals (Sweden)

    ÁLVARO T. PALMA

    2002-03-01

    crustáceos anfípodos. En nuestro estudio, se consideró dos poblaciones ampliamente separadas de C. variegatus (centro y norte de Chile. Los individuos que integran estas poblaciones exhiben claras diferencias en su distribución, abundancia y comportamiento trófico. En la zona norte, la especie es abundante y tanto juveniles como adultos se distribuyen a lo largo de todo el gradiente batimétrico. Esto contrasta con las poblaciones de la zona central de Chile, las que están más dispersas y desprovistas de juveniles. El patrón de distribución y abundancia parece estar principalmente influenciado por la gran abundancia de diversas especies de macroalgas que conforman el subdosel en el submareal del norte, el que es habitado por un gran número de invertebrados, especialmente anfípodos. En contraste, la abundancia de algas del subdosel de la zona central es mucho menor y no muestra una relación directa con la menor abundancia de anfípodos observada. La tasa de consumo que C. variegatus ejerce sobre anfípodos es en general alta durante toda su ontogenia, incorporando a otros ítems presa en estadíos ontogenéticos posteriores. Es posible que los diferentes ensambles de diversas algas de subdosel, junto con su fauna asociada, sean el principal factor que afecta los patrones de abundancia y distribución observado entre estas dos poblaciones de peces geograficamente distintas

  18. Logfile-Analysen zur Evaluation der didaktischen Einbettung von CSCL-Systemen - am Beispiel der CommSy-Nutzung in offenen Seminaren

    Directory of Open Access Journals (Sweden)

    Martin Klein

    2005-02-01

    Full Text Available In unserem Beitrag evaluieren wir die didaktische Einbettung einer CSCL-Anwendung anhand von Logfile-Analysen. Dazu betrachten wir exemplarisch die Nutzung des webbasierten Systems CommSy in einer projektorientierten Lehrveranstaltung, die wir als offenes Seminar charakterisieren. Wir erzielen zwei Ergebnisse: (1 Wir geben Hinweise zur Gestaltung des Nutzungskontexts eines CSCL-Systems sowie zur Unterstützung seiner anfänglichen und kontinuierlichen Nutzung. (2 Wir beschreiben die Analyse von Nutzungsanlässen und -mustern sowie von NutzerInnentypen anhand von Logfiles. Dabei können Logfile-Analysen zur Validierung weiterer Evaluationsergebnisse dienen, sind selbst jedoch nur in Kombination mit zusätzlichen Informationen zum Nutzungskontext interpretierbar.

  19. A new species of Hyalella from the Andes in Perú (Crustacea: Amphipoda: Hyalellidae

    Directory of Open Access Journals (Sweden)

    Exequiel R González

    2002-06-01

    Full Text Available Hyalella pauperocavae n. sp. from Huancayo, Perú, is described. Five other epigean freshwater amphipods have been described from Peru (excluding Lake Titicaca, but the lack of type material and poor descriptions do not allow the assignment of the species described here to any of the names known for the areaSe describe la especie Hyalella pauperocavae n. sp. recolectada en la localidad de Huancayo, Perú. Otras cinco especies de anfípodos epígeos se conocen para el Perú (excluyendo aquellas presentes en el Lago Titicaca. La ausencia de material tipo y descripciones poco claras impidieron la asignación de la especie descrita aquí a alguno de los nombres conocidos para el área

  20. The Implications of Encoder/Modulator/ Phased Array Designs for Future Broadband LEO Communications

    Science.gov (United States)

    Vanderaar, Mark; Jensen, Chris A.; Terry, John D.

    1997-01-01

    In this paper we summarize the effects of modulation and channel coding on the design of wide angle scan, broadband, phased army antennas. In the paper we perform several trade studies. First, we investigate the amplifier back-off requirement as a function of variability of modulation envelope. Specifically, we contrast constant and non-constant envelope modulations, as well as single and multiple carrier schemes. Additionally, we address the issues an(f concerns of using pulse shaping filters with the above modulation types. Second, we quantify the effects of beam steering on the quality of data, recovery using selected modulation techniques. In particular, we show that the frequency response of the array introduces intersymbol interference for broadband signals and that the mode of operation for the beam steering controller may introduce additional burst or random errors. Finally, we show that the encoder/modulator design must be performed in conjunction with the phased array antenna design.