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Sample records for hydrochlorofluorocarbon hcfc blowing

  1. IDENTIFICATION OF CFC AND HCFC SUBSTITUTES FOR BLOWING POLYURETHANE FOAM INSULATION PRODUCTS

    Science.gov (United States)

    The report gives results of a cooperative effort to identiry chlorofluorocarbons and hydrochlorofluorocarbon substitutes for blowing polyurethane foam insulation products. The substantial ongoing effort is identifying third-generation blowing agets for polyurethane foams to repla...

  2. IDENTIFICATION OF CFC AND HCFC SUBSTITUTES FOR BLOWING POLYURETHANE FOAM INSULATION PRODUCTS

    Science.gov (United States)

    The report gives results of a cooperative effort to identiry chlorofluorocarbons and hydrochlorofluorocarbon substitutes for blowing polyurethane foam insulation products. The substantial ongoing effort is identifying third-generation blowing agets for polyurethane foams to repla...

  3. Replacement of Hydrochlorofluorocarbon (HCFC) -225 Solvent for Cleaning and Verification Sampling of NASA Propulsion Oxygen Systems Hardware, Ground Support Equipment, and Associated Test Systems

    Science.gov (United States)

    Burns, H. D.; Mitchell, M. A.; McMillian, J. H.; Farner, B. R.; Harper, S. A.; Peralta, S. F.; Lowrey, N. M.; Ross, H. R.; Juarez, A.

    2015-01-01

    Since the 1990's, NASA's rocket propulsion test facilities at Marshall Space Flight Center (MSFC) and Stennis Space Center (SSC) have used hydrochlorofluorocarbon-225 (HCFC-225), a Class II ozone-depleting substance, to safety clean and verify the cleanliness of large scale propulsion oxygen systems and associated test facilities. In 2012 through 2014, test laboratories at MSFC, SSC, and Johnson Space Center-White Sands Test Facility collaborated to seek out, test, and qualify an environmentally preferred replacement for HCFC-225. Candidate solvents were selected, a test plan was developed, and the products were tested for materials compatibility, oxygen compatibility, cleaning effectiveness, and suitability for use in cleanliness verification and field cleaning operations. Honewell Soltice (TradeMark) Performance Fluid (trans-1-chloro-3,3, 3-trifluoropropene) was selected to replace HCFC-225 at NASA's MSFC and SSC rocket propulsion test facilities.

  4. NASA Rocket Propulsion Test Replacement Effort for Oxygen System Cleaner - Hydrochlorofluorocarbon (HCFC) 225

    Science.gov (United States)

    DeWitt Burns, H.; Mitchell, Mark A.; Lowrey, Nikki M.; Farner, Bruce R.; Ross, H. Richard

    2014-01-01

    Gaseous and liquid oxygen are extremely reactive materials used in bipropellant propulsion systems. Both flight and ground oxygen systems require a high level of cleanliness to support engine performance, testing, and prevent mishaps. Solvents used to clean and verify the cleanliness of oxygen systems and supporting test hardware must be compatible with the system's materials of construction and effective at removing or reducing expected contaminants to an acceptable level. This paper will define the philosophy and test approach used for evaluating replacement solvents for the current Marshall Space Flight Center/Stennis Space Center baseline HCFC-225 material that will no longer be available for purchase after 2014. MSFC/SSC applications in cleaning / sampling oxygen propulsion components, support equipment, and test system were reviewed then candidate replacement cleaners and test methods selected. All of these factors as well as testing results will be discussed.

  5. Three-dimensional modeling of HCFC-123 in the atmosphere: assessing its potential environmental impacts and rationale for continued use.

    Science.gov (United States)

    Wuebbles, Donald J; Patten, Kenneth O

    2009-05-01

    HCFC-123 (C2HCl2F3) is used in large refrigeration systems and as a fire suppression agent blend. Like other hydrochlorofluorocarbons, production and consumption of HCFC-123 is limited under the Montreal Protocol on Substances that Deplete the Ozone Layer. The purpose of this study is to update the understanding of the current and projected impacts of HCFC-123 on stratospheric ozone and on climate and to discuss the potential environmental effects from continued use of this chemical for specific applications. For the first time, the Ozone Depletion Potential (ODP) of a HCFC is determined using a three-dimensional model (MOZART-3) of atmospheric physics and chemistry. All previous studies have relied on results from two-dimensional models. The derived HCFC-123 ODP of 0.0098 is smaller than previous values. Analysis of the projected uses and emissions of HCFC-123, assuming reasonable levels of projected growth and use in centrifugal chiller and fire suppressant applications, suggests an extremely small impact on the environment due to its short atmospheric lifetime, low ODP, low Global Warming Potential (GWP), and the small production and emission of its limited applications. The current contribution of HCFC-123 to stratospheric reactive chlorine is too small to be measurable.

  6. Ozone Depletion Potentials of HCFC-123 and HCFC-124

    Science.gov (United States)

    Riepe, E. L.; Patten, K. O.; Wuebbles, D. J.

    2005-05-01

    The Montreal Protocol has phased out most chlorinated and brominated compounds because of their great efficiency in depleting ozone in the stratosphere. Compounds such as CHCl2CF3 (HCFC-123) and CHClFCF3 (HCFC-124) are being used in commercial refrigeration units and have much shorter atmospheric lifetimes than the chlorofluorocarbons they replace. Despite their small resulting Ozone Depletion Potentials (ODPs), these compounds are still currently expected to be eliminated under the existing Protocol, but there remain questions about finding suitable replacements that would not have other environmental effects. The HCFC-123 and HCFC-124 model-calculated atmospheric lifetimes of 1.3 years and 5.8 years are much shorter compared to the 45 years of CCl3F (CFC-11). In this study, we have reevaluated these compounds with an updated version of the UIUC two-dimensional chemical transport model and with the MOZART (version 3) three-dimensional chemical-transport model. The new version of the two-dimensional model gives ODPs of 0.012 and 0.0125 for HCFC-123 and HCFC-124, respectively. The ODP for HCFC-123 agrees well with previously reported values while the ODP for HCFC-124 is much smaller than earlier estimates. These analyses along with those from the three-dimensional modeling studies will be discussed in the presentation.

  7. New and improved infrared absorption cross sections for chlorodifluoromethane (HCFC-22)

    Science.gov (United States)

    Harrison, Jeremy J.

    2016-06-01

    The most widely used hydrochlorofluorocarbon (HCFC) commercially since the 1930s has been chloro-difluoromethane, or HCFC-22, which has the undesirable effect of depleting stratospheric ozone. As this molecule is currently being phased out under the Montreal Protocol, monitoring its concentration profiles using infrared sounders crucially requires accurate laboratory spectroscopic data. This work describes new high-resolution infrared absorption cross sections of chlorodifluoromethane over the spectral range 730-1380 cm-1, determined from spectra recorded using a high-resolution Fourier transform spectrometer (Bruker IFS 125HR) and a 26 cm pathlength cell. Spectra of chlorodifluoromethane/dry synthetic air mixtures were recorded at resolutions between 0.01 and 0.03 cm-1 (calculated as 0.9/MOPD; MOPD denotes the maximum optical path difference) over a range of temperatures and pressures (7.5-762 Torr and 191-295 K) appropriate for atmospheric conditions. This new cross-section dataset improves upon the one currently available in the HITRAN (HIgh-resolution TRANsmission) and GEISA (Gestion et Etude des Informations Spectroscopiques Atmosphériques) databases; in particular it provides coverage over a wider range of pressures and temperatures, has more accurate wavenumber scales, more consistent integrated band intensities, improved signal-to-noise, is free of channel fringing, and additionally covers the ν2 and ν7 bands.

  8. 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, L. 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

  9. Analysis list: Hcfc1 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Hcfc1 Blood,Pluripotent stem cell + mm9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Hcfc1....1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Hcfc1.5.tsv http://dbarchive.bi...osciencedbc.jp/kyushu-u/mm9/target/Hcfc1.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Hcfc1.Bl...ood.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Hcfc1.Pluripotent_ste

  10. Validation of ACE-FTS measurements of CFC-11, CFC-12, and HCFC-22 using ground-based FTIR spectrometers

    Science.gov (United States)

    Kolonjari, F.; Walker, K. A.; Mahieu, E.; Batchelor, R. L.; Bernath, P. F.; Boone, C.; Conway, S. A.; Dan, L.; Griffin, D.; Harrett, A.; Kasai, Y.; Kagawa, A.; Lindenmaier, R.; Strong, K.; Whaley, C.

    2013-12-01

    Satellite datasets can be an effective global monitoring tool for long-lived compounds in the atmosphere. The Atmospheric Chemistry Experiment (ACE) is a mission on-board the Canadian satellite SCISAT-1. The primary instrument on SCISAT-1 is a high-resolution infrared Fourier transform spectrometer (ACE-FTS) which is capable of measuring a range of gases including key chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) species. These families of species are of interest because of their significant contribution to anthropogenic ozone depletion and to global warming. To assess the quality of data derived from satellite measurements, validation using other data sources is essential. Ground-based Fourier transform infrared (FTIR) spectrometers are particularly useful for this purpose. In this study, five FTIR spectrometers located at four sites around the world are used to validate the CFC-11 (CCl3F), CFC-12 (CCl2F2), and HCFC-22 (CHClF2) retrieved profiles from ACE-FTS measurements. These species are related because HCFC-22 was the primary replacement for CFC-11 and CFC-12 in refrigerant and propellant applications. The FTIR spectrometers used in this study record solar absorption spectra at Eureka (Canada), Jungfraujoch (Switzerland), Poker Flat (USA), and Toronto (Canada). The retrieval of CFC-11, CFC-12, and HCFC-22 are not standard products for many of these instruments, and as such, a harmonization of retrieval parameters between the sites has been conducted. The retrievals of these species from the FTIR spectra are sensitive from the surface to approximately 20 km, while the ACE-FTS profiles extend from approximately 6 to 30 km. For each site, partial column comparisons between coincident measurements of the three species and a validation of the observed trends will be discussed.

  11. The technical viability of alternative blowing agents in polyisocyanurate roof insulation

    Energy Technology Data Exchange (ETDEWEB)

    Christian, J.E.; Courville, G.E.; Linkous, R.L.; Wendt, R.L.; Graves, R.S. (Oak Ridge National Lab., TN (USA)); Smith, T.L. (National Roofing Contractors Association, Chicago, IL (USA))

    1990-01-01

    This paper presents a progress report on field thermal performance measurements on a set of private industry-produced, experimental polyisocyanurate laminate board stock foams blown with CFC-11, HCFC-123, HCFC-141b, 50/50, and 65/35 blends of HCFC-123/HCFC-141b. These boards have been observed for almost 300 days of roof field exposure in East Tennessee. The field data are used to derive an empirical model which can be used to predict effective diffusion coefficients for the air components into the foam cells. These diffusion coefficients are compared with those developed from steady state laboratory measurements of thin sliced samples from the same batch of experimental boards. The relative performance of test specimens of HCFC-141b under a black and under a white membrane are reported. The aging of the HCFC-141b blown foam under the white membrane occurred more slowly during cold weather, but accelerated after the winter season, resulting in no significant resistivity difference after 280 days of exposure from September 1989 until May 1990. The field data analysis suggests that the percent increase in k over that of the foam blown with CFC-11 is, after one year of aging, 5.5% for HCFC-123 and 11.7% for HCFC-141b. This leads to the same ordering as derived from the laboratory thin-slicing analysis report in Part 3 of this session. Additional plans are described for further thermal and mechanical property measurements to be conducted on two ORNL roof field testers. After the first year of this three-year study, there has been no indication that thermal performance differences are serious enough to suggest that any or all of the HCFC alternate blowing agents would not be technically viable in polyisocyanurate roof insulations. 5 refs., 19 figs.

  12. Consumption of HCFC-22 Increases Steadily

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Chlorodifluoromethane (HCFC-22) is an important fluorine chemical product. It can be directly used as refrigerant in household air-conditioners and refrigerators and also as chemical raw material to produce fluorine-containing polymer monomer tetrafluoroethylene (TFE) to extend the fluorine chemical industrial chain.

  13. Alternatives to HCFC-22 for air conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Devotta, S. [Council of Scientific and Industrial Research, National Chemical Lab., Pune (India); Waghmare, A.V.; Domkundwar, B.M. [College of Engineering, Pune (India); Sawant, N.N. [National Inst. of Standards and Technology, Gaithersburg, MD (United States)

    2001-04-01

    Some selected fluids have been assessed for their suitability as alternatives to HCFC-22 for air conditioners. Only those refrigerants with zero ozone depletion potential are considered. NIST CYCLE{sub D} has been used for the comparative thermodynamic analysis. Among the refrigerants studied (HFC-134a, HC-290, R-407C, R-410A, and three blends of HFC-32, HFC-134a and HFC-125), HFC-134a offers the highest COP, but its capacity is the lowest and requires much larger compressors. The characteristics of HC-290 are very close to those of HCFC-22, and compressors require very little modification. Therefore, HC-290 is a potential candidate provided the risk concerns are mitigated as had been accomplished for refrigerators. For retrofitting, R-407C is probably the best candidate. (Author)

  14. 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.

  15. Analysis list: HCFC1 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available HCFC1 Blood,Uterus + hg19 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/HC...FC1.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/HCFC1.5.tsv http://dbarchive.biosciencedbc....jp/kyushu-u/hg19/target/HCFC1.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/HCFC1.Blood.tsv,http://dbarchive.bioscience...dbc.jp/kyushu-u/hg19/colo/HCFC1.Uterus.tsv http://dbarchive.bioscience...dbc.jp/kyushu-u/hg19/colo/Blood.gml,http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/Uterus.gml ...

  16. Global and regional emission estimates for HCFC-22

    Directory of Open Access Journals (Sweden)

    E. Saikawa

    2012-11-01

    Full Text Available HCFC-22 (CHClF2, chlorodifluoromethane is an ozone-depleting substance (ODS as well as a significant greenhouse gas (GHG. HCFC-22 has been used widely as a refrigerant fluid in cooling and air-conditioning equipment since the 1960s, and it has also served as a traditional substitute for some chlorofluorocarbons (CFCs controlled under the Montreal Protocol. A low frequency record on tropospheric HCFC-22 since the late 1970s is available from measurements of the Southern Hemisphere Cape Grim Air Archive (CGAA and a few Northern Hemisphere air samples (mostly from Trinidad Head using the Advanced Global Atmospheric Gases Experiment (AGAGE instrumentation and calibrations. Since the 1990s high-frequency, high-precision, in situ HCFC-22 measurements have been collected at these AGAGE stations. Since 1992, the Global Monitoring Division of the National Oceanic and Atmospheric Administration/Earth System Research Laboratory (NOAA/ESRL has also collected flasks on a weekly basis from remote sites across the globe and analyzed them for a suite of halocarbons including HCFC-22. Additionally, since 2006 flasks have been collected approximately daily at a number of tower sites across the US and analyzed for halocarbons and other gases at NOAA. All results show an increase in the atmospheric mole fractions of HCFC-22, and recent data show a growth rate of approximately 4% per year, resulting in an increase in the background atmospheric mole fraction by a factor of 1.7 from 1995 to 2009. Using data on HCFC-22 consumption submitted to the United Nations Environment Programme (UNEP, as well as existing bottom-up emission estimates, we first create globally-gridded a priori HCFC-22 emissions over the 15 yr since 1995. We then use the three-dimensional chemical transport model, Model for Ozone and Related Chemical Tracers version 4 (MOZART v4, and a Bayesian inverse method to estimate global as well as regional annual emissions. Our inversion indicates

  17. File list: Oth.ALL.05.Hcfc1.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.ALL.05.Hcfc1.AllCell mm9 TFs and others Hcfc1 All cell types SRX188798,SRX18881...9,SRX188815,SRX185705 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.ALL.05.Hcfc1.AllCell.bed ...

  18. Five Blows to Mankind's Narcissism.

    Science.gov (United States)

    Pedrini, D. T.; Pedrini, Bonnie C.

    1978-01-01

    Freud identified three blows to mankind's narcissism--cosmological, biological, and psychological. Conjectural fourth and fifth blows might be universological (the discovery of other intelligent beings) and earthological (the demise of this planet via waste, pollution, etc.). (Author/JC)

  19. Performance assessment of HCFC-22 window air conditioner retrofitted with R-407C

    Energy Technology Data Exchange (ETDEWEB)

    Devotta, S. [National Environmental Engineering Research Institute, Nehru Marg, Nagpur 440 020 (India); Padalkar, A.S. [Process Development Division, National Chemical Laboratory, Homi Bhabha Road, Pune 411 008 (India); Sane, N.K. [Department of Mechanical Engineering, Walchand College of Engineering, Sangli 416 415 (India)

    2005-12-01

    This paper presents the experimental performance analysis of a 1.5 TR window air-conditioner, retrofitted with R-407C, as a substitute to HCFC-22. Experimental results showed that R-407C, for the operating conditions covered in this study, had lower cooling capacity in the range 2.1-7.9% with respect to HCFC-22. The coefficient of performance for R-407C was lower in the range 7.9-13.5%. The power consumption of the unit with R-407C was higher in the range 6-7% than HCFC-22. The discharge pressures for R-407C were higher in the range 11-13% than HCFC-22. This paper also presents simulation results of heat exchangers of an HCFC-22 window air conditioner retrofitted with R-407C. The simulation has been carried out using EVAP-COND, a heat exchanger model developed by National Institute of Standards and Technology, U.S.A. The simulated evaporator capacities are within +/-3% of the experimentally measured cooling capacities for both refrigerants. Simulation results for R-407C and HCFC-22 are compared. The exit temperatures of R-407C are lower by 1.9{sup o}C to 5.2{sup o}C in the condenser and are higher by 3.2{sup o}C to 3.8{sup o}C in the evaporator than HCFC-22. Evaporating pressures of R-407C are higher by 4.5-5.3% as compared to HCFC-22. The pressure drops of R-407C are lower in both the evaporator and the condenser as compared to HCFC-22. The outlet temperatures of air for HCFC-22 and R-407C in both heat exchangers are nearly the same. (author)

  20. The Next Blows?

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The unfolding global financial crisis is arousing jitters about another round of heavy blows to the world economy, which may be intensified by the possible U.S. government takeover of Citigroup Inc. and Bank of America Corp. lg, Chief Economist of the Asia-Pacific region for Credit Suisse First Boston (Hong Kong ) Ltd., published an article in the Securities Market Weekly, warning about five other major crashes that might dampen global economic recovery. Edited excerpts follow.

  1. VISUAL OBSERBATION OF HCFC141b GAS HYDRATE FORMATION/DECOMPOSITION PROCESS OUTSIDE OF A TUBE

    Institute of Scientific and Technical Information of China (English)

    谢应明; 郭开华; 樊栓狮; 梁德青; 顾建明

    2003-01-01

    In order to design a kind of heat exchanger suitable to the indirect-touched gas hydrate cool storage vessel, a visual observation of HCFC141b gas hydrate formation/decomposition process was presented through a self-designed small-scale visualization apparatus of gas hydrate cool storage. Based on the shooted photos and recorded temperatures, the formation/decomposition process of HCFC141b are described, some characteristics are concluded, and some suggestions of designing heat exchanger are indicated according to the specific characteristics of HCFC141b gas hydrate formation/decomposition process.

  2. EXPERIMENTAL STUDY ON A NEW ALTERNATIVE REFRIGERANT TO HCFC-22%一种HCFC-22新型替代制冷剂的实验研究

    Institute of Scientific and Technical Information of China (English)

    宣永梅; 陈光明; 陈斌; 王勤

    2004-01-01

    本文提出采用三元混合工质HFC-161/HFC-125/HFC-32作为HCFC-22替代制冷剂.在空气-水热泵实验台上对该工质及HCFC-22、R407C进行对比实验,结果表明,在不改动任何系统部件的前提下,该新型制冷剂的COP值大于HGFC-22主要替代制冷剂R.407C,在较高的进风温度或较低的进水温度下,COP值接近甚至大于HCFC-22.此外,该三元混合物还具有GWF值小、排气温度低、温度滑移小的优点,是HCFC-22一种有前途的替代物.

  3. First retrievals of HCFC-142b from ground-based high-resolution FTIR solar observations: application to high-altitude Jungfraujoch spectra

    Science.gov (United States)

    Mahieu, Emmanuel; O'Doherty, Simon; Reimann, Stefan; Vollmer, Martin; Bader, Whitney; Bovy, Benoît; Lejeune, Bernard; Demoulin, Philippe; Roland, Ginette; Servais, Christian; Zander, Rodolphe

    2013-04-01

    Hydrofluorocarbons (HCFCs) are the first substitutes to the long-lived ozone depleting halocarbons, in particular the chlorofluorocarbons (CFCs). Given the complete ban of the CFCs by the Montreal Protocol, its Amendments and Adjustments, HCFCs are on the rise, with current rates of increase substantially larger than at the beginning of the 21st century. HCFC-142b (CH3CClF2) is presently the second most abundant HCFCs, after HCFC-22 (CHClF2). It is used in a wide range of applications, including as a blowing foam agent, in refrigeration and air-conditioning. Its concentration will soon reach 25 ppt in the northern hemisphere, with mixing ratios increasing at about 1.1 ppt/yr [Montzka et al., 2011]. The HCFC-142b lifetime is estimated at 18 years. With a global warming potential of 2310 on a 100-yr horizon, this species is also a potent greenhouse gas [Forster et al., 2007]. First space-based retrievals of HCFC-142b have been reported by Dufour et al. [2005]. 17 occultations recorded in 2004 by the Canadian ACE-FTS instrument (Atmospheric Chemistry Experiment - Fourier Transform Spectrometer, onboard SCISAT-1) were analyzed, using two microwindows (1132.5-1135.5 and 1191.5-1195.5 cm-1). In 2009, Rinsland et al. determined the HCFC-142b trend near the tropopause, from the analysis of ACE-FTS observations recorded over the 2004-2008 time period. The spectral region used in this study extended from 903 to 905.5 cm-1. In this contribution, we will present the first HCFC-142b measurements from ground-based high-resolution Fourier Transform Infrared (FTIR) solar spectra. We use observations recorded at the high altitude station of the Jungfraujoch (46.5°N, 8°E, 3580 m asl), with a Bruker 120HR instrument, in the framework of the Network for the Detection of Atmospheric Composition Change (NDACC, visit http://www.ndacc.org). The retrieval of HCFC-142b is very challenging, with simulations indicating only weak absorptions, lower than 1% for low sun spectra and current

  4. Emission Inventory Prediction of HCFC-141b in China%中国HCFC-141b排放清单预测

    Institute of Scientific and Technical Information of China (English)

    颜锽锽; 张剑波

    2011-01-01

    Emission inventory of HCFC-141b in China was established based on the IPCC Guidelines for National Greenhouse Gas Inventories(2006).Constitution and trend of HCFC-141b emission was analyzed.The product retire emission,which considered to be the largest part of emission,accounts for 48.7% of the total;under Montreal Protocol Phaseout Schedule(MPPS) and Accelerated Phaseout Schedule(APS) scenarios,total ODP emission reduction would be 7.30×104 tons and 7.46×104 tons ODP and GHG emission reduction would be 4.7317×108 tons and 4.8381×108 tons CO2-eq respectively during 2010-2030;compared to the MPPS scenario,the APS scenario result in additional 3.815×107 tons CO2-eq GHG emission reduction during HCFC-141b emission period and most of the reduction comes from refrigerator,water heater insulation and panel sub-sector.China makes great contribution on global GHGs reduction during the implementation of Montreal Protocol.%基于IPCC《国家温室气体清单优良作法指南(2006)》建立中国HCFC-141b排放清单,分析计算中国HCFC-141b的排放构成和排放趋势。退役排放构成中国HCFC-141b排放的主要部分,占总排放量的48.7%;在蒙特利尔议定书控制淘汰(MPPS)情景和加速淘汰(APS)情景下,2010—2030年分别累计减排量为7.30万t和7.46万t ODP,相当于47317万t和48381万t CO2-eq温室气体(GHG);在APS情景下,由于淘汰力度加强,在HCFC-141b排放时段内,相比MPPS情景进一步减排3815万t CO2-eq GHG,其中大部分减排量由冷藏保温、热水器保温和板材子源贡献。中国履行《关于消耗臭氧层物质的蒙特利尔议定书》不仅减少了ODS排放,同时也减少了温室气体排放。

  5. Simulated consumer exposure to propellant HCFC 22 (chlorodifluoromethane) in aerosol personal products.

    Science.gov (United States)

    Hartop, P J; Adams, M G

    1989-02-01

    Summary The potential human exposure to the aerosol propellant HCFC 22 (chlorodifluoromethane) arising from its use in personal products has been assessed. HCFC 22 concentrations were measured in the 'breathing zone' of an experimental manikin and an 'accompanying child' designed to simulate human use of hairsprays, body sprays and antiperspirants in a closed room. Results were expressed as the 10-min time-weighted average concentration in the air (TWA 10) and as the peak concentration in the 'breathing zone' of the 'user'. Following a 10-s use of hairspray containing approximately 20-40% HCFC 22, TWA10 values for an adult user and child were 64-116 ppm and 44-100 ppm, respectively. Use of an aerosol body spray containing 20-65% HCFC 22 for 5-20 s gave rise to TWA10 values of 32-411 ppm for an adult user and 20-395 ppm for a child. A 4-s use of an antiperspirant containing approximately 20-40% HCFC 22 sprayed at a distance of 10-30 cm from the breathing zone of the adult user generated TWA 10 values in the range of 14-34 ppm for both the adult user and child. Opening the door of the room prior to hairspray and antiperspirant spraying slightly reduced these TWA 10 values. The peak values recorded in these studies for the adult user were 208 ppm for hairspray, 1415 ppm for body sprays and 82 ppm for antiperspirants.

  6. A noncoding, regulatory mutation implicates HCFC1 in nonsyndromic intellectual disability.

    Science.gov (United States)

    Huang, Lingli; Jolly, Lachlan A; Willis-Owen, Saffron; Gardner, Alison; Kumar, Raman; Douglas, Evelyn; Shoubridge, Cheryl; Wieczorek, Dagmar; Tzschach, Andreas; Cohen, Monika; Hackett, Anna; Field, Michael; Froyen, Guy; Hu, Hao; Haas, Stefan A; Ropers, Hans-Hilger; Kalscheuer, Vera M; Corbett, Mark A; Gecz, Jozef

    2012-10-01

    The discovery of mutations causing human disease has so far been biased toward protein-coding regions. Having excluded all annotated coding regions, we performed targeted massively parallel resequencing of the nonrepetitive genomic linkage interval at Xq28 of family MRX3. We identified in the binding site of transcription factor YY1 a regulatory mutation that leads to overexpression of the chromatin-associated transcriptional regulator HCFC1. When tested on embryonic murine neural stem cells and embryonic hippocampal neurons, HCFC1 overexpression led to a significant increase of the production of astrocytes and a considerable reduction in neurite growth. Two other nonsynonymous, potentially deleterious changes have been identified by X-exome sequencing in individuals with intellectual disability, implicating HCFC1 in normal brain function.

  7. Holes at High Blowing Ratios

    Directory of Open Access Journals (Sweden)

    Phillip M. Ligrani

    1996-01-01

    Full Text Available Experimental results are presented which describe the development and structure of flow downstream of a single row of holes with compound angle orientations producing film cooling at high blowing ratios. This film cooling configuration is important because similar arrangements are frequently employed on the first stage of rotating blades of operating gas turbine engines. With this configuration, holes are spaced 6d apart in the spanwise direction, with inclination angles of 24 degrees, and angles of orientation of 50.5 degrees. Blowing ratios range from 1.5 to 4.0 and the ratio of injectant to freestream density is near 1.0. Results show that spanwise averaged adiabatic effectiveness, spanwise-averaged iso-energetic Stanton number ratios, surveys of streamwise mean velocity, and surveys of injectant distributions change by important amounts as the blowing ratio increases. This is due to injectant lift-off from the test surface just downstream of the holes.

  8. Performance assessment of HC-290 as a drop-in substitute to HCFC-22 in a window air conditioner

    Energy Technology Data Exchange (ETDEWEB)

    Devotta, S. [National Environmental Engineering Research Institute, Nagpur (India); Padalkar, A.S. [National Chemical Laboratory, Pune (India). Process Development Division; Sane, N.K. [Walchand College of Engineering, Sangli (India). Department of Mechanical Engineering

    2005-06-01

    As per the Montreal Protocol, CFCs and HCFCs are being phased out. HCFC-22 is used in window air conditioners. This paper presents the experimental performance study of a window air conditioner with propane (HC-290), a natural refrigerant, as a drop-in substitute to HCFC-22. Experimental results showed that HC-290 had 6.6% lower cooling capacity for the lower operating conditions and 9.7% lower for the higher operating conditions with respect to HCFC-22. The coefficient of performance for HC-290 was 7.9% higher for the lower operating conditions and 2.8% higher for the higher operating conditions. The energy consumption of the unit with HC-290 was lower in the range 12.4-13.5% than HCFC-22. The discharge pressures for HC-290 were lower in the range 13.7-18.2% than HCFC-22. For HC-290, the pressure drop was lower than HCFC-22 in both heat exchangers. This paper also presents simulation results for the heat exchangers of an HCFC-22 window air conditioner with HC-290 as a drop-in substitute. The simulation has been carried out using EVAP-COND, a heat exchanger model developed by NIST [National Institute of Standards and Technology. EVAP-COND: simulation models for finned-tube heat exchangers, Maryland, USA (2003). http://www2.bfrl.nist.gov/software/evap-cond/ [18

  9. The Early Years: Blowing Bubbles

    Science.gov (United States)

    Ashbrook, Peggy

    2016-01-01

    Blowing bubbles is not only a favorite summer activity for young children. Studying bubbles that are grouped together, or "foam," is fun for children and fascinating to many real-world scientists. Foam is widely used--from the bedroom (mattresses) to outer space (insulating panels on spacecraft). Bubble foam can provide children a…

  10. Leakage Evaluation of Blend Refrigerant HCFC-22/HFC-152a for Auto mobile Air Conditioners%混合工质HCFC-22/HFC-152a汽车空调系统中泄漏性能分析

    Institute of Scientific and Technical Information of China (English)

    张华; 谷松

    2001-01-01

    A analysis of leakage is carried out for automobile air conditioner charged with HCFC-22/HFC-152a. The performance of automobile air conditioners doesn,t obvio usly change when leakage of the blend refrigerant happens. The HCFC-22/HFC-152a( 40/60mass%) can be used as alternative refrigerant in the transition period of e xisting automobile air conditioners.%对采用HCFC-22/HFC-152a混合制冷剂的汽车空调的 泄漏性能进行了分析;说明了HCFC-22/HFC-152a混合制冷剂不会因泄漏引起制冷系统性 能的显著变化,它可作为现有的汽车空调系统的过渡替代工质。

  11. Development of mass production type rigid polyurethane foam for LNG carrier using ozone depletion free blowing agent

    Science.gov (United States)

    Lee, Yeongbeom; Baek, Kye Hyun; Choe, Kunhyung; Han, Chonghun

    2016-12-01

    Nowadays the price of natural gas has become higher and the efficiency of propulsion system of liquefied natural gas (LNG) carriers has improved. Due to these trends, required boil-off rate (BOR) for LNG carrier has been lowered from 0.15%/day to 0.12%/day for conventional LNG carriers with sizes between 125,000 m3 and 170,000 m3. This requirement of BOR can be satisfied by using a rigid polyurethane foam (PUF) blown by 1,1-dichloro-1-fluoroethane (HCFC-141b) as an insulator. However, ozone depletion potential (ODP) of HCFC-141b requires alternative blowing agents with zero ODP such as hydroflurocarbons (HFCs) because of tougher environmental regulations. This paper introduces use of HFCs and additives to enhance properties of rigid PUFs under a mass production environment. Among the additives, perfluoroalkane (PFA) reduces thermal conductivity down to 12% and increases compressive strength up to 15% of a rigid PUF prepared in a laboratory scale. Based on this result, a mass production type rigid PUF is manufactured and is evaluated for BOR, mechanical strengths over operation temperature range, and thermal shock stability for LNG carriers. The BOR of the manufactured rigid PUF is below 0.12%/day, which satisfies the recent BOR specification for LNG carriers. The other required properties are also met the specifications for a conventional LNG carrier. Consequently, it is expected that the results in this paper will bring low BOR (LNG carries with rigid PUFs using ODP free blowing agents and contribute environmental protection through saving energy and preserving the ozone layer in the stratosphere.

  12. Evaluation of HCFC AK 225 Alternatives for Precision Cleaning and Verification

    Science.gov (United States)

    Melton, D. M.

    1998-01-01

    Maintaining qualified cleaning and verification processes are essential in an production environment. Environmental regulations have and are continuing to impact cleaning and verification processing in component and large structures, both at the Michoud Assembly Facility and component suppliers. The goal of the effort was to assure that the cleaning and verification proceeds unimpeded and that qualified, environmentally compliant material and process replacements are implemented and perform to specifications. The approach consisted of (1) selection of a Supersonic Gas-Liquid Cleaning System; (2) selection and evaluation of three cleaning and verification solvents as candidate alternatives to HCFC 225 (Vertrel 423 (HCFC), Vertrel MCA (HFC/1,2-Dichloroethylene), and HFE 7100DE (HFE/1,2 Dichloroethylene)); and evaluation of an analytical instrumental post cleaning verification technique. This document is presented in viewgraph format.

  13. Blowing up generalized Kahler 4-manifolds

    CERN Document Server

    Cavalcanti, Gil R

    2011-01-01

    We show that the blow-up of a generalized Kahler 4-manifold in a nondegenerate complex point admits a generalized Kahler metric. As with the blow-up of complex surfaces, this metric may be chosen to coincide with the original outside a tubular neighbourhood of the exceptional divisor. To accomplish this, we develop a blow-up operation for bi-Hermitian manifolds.

  14. Thermoplastic blow molding of metals

    Directory of Open Access Journals (Sweden)

    Jan Schroers

    2011-01-01

    Full Text Available While plastics have revolutionized industrial design due to their versatile processability, their relatively low strength has hampered their use in structural components. On the other hand, while metals are the basis for strong structural components, the geometries into which they can be processed are rather limited. The “ideal” material would offer a desirable combination of superior structural properties and the ability to be precision (net shaped into complex geometries. Here we show that bulk metallic glasses (BMGs, which have superior mechanical properties, can be blow molded like plastics. The key to the enhanced processability of BMG formers is their amenability to thermoplastic forming. This allows complex BMG structures, some of which cannot be produced using any other metal process, to be net shaped precisely.

  15. Historical and projected emissions of HCFC-22 and HFC-410A from China's room air conditioning sector

    Science.gov (United States)

    Wang, Ziyuan; Fang, Xuekun; Li, Li; Bie, Pengju; Li, Zhifang; Hu, Jianxin; Zhang, Boya; Zhang, Jianbo

    2016-05-01

    Recent decades witnessed the increase in production and uses of HCFC-22 (chlorodifluoromethane, CHClF2) and its alternative, HFC-410A (a blend of difluoromethane and pentafluoroethane), in China in response to the booming of room air conditioners (RACs) for both domestic use and exports. HCFC-22 is an ozone-depleting substance under the Montreal Protocol, while both HCFC-22 and HFC-410A are greenhouse gases (GHGs). This study provides a most comprehensive consumption and emission inventory of refrigerants emissions (HCFC-22 and HFC-410A) from RAC sector during 1995-2014, for the first time. Our estimates show that HCFC-22 emissions increased from 0.7 Gg/yr in 1995 to 48.2 Gg/yr in 2014. The accumulative emissions contributed to global total HCFCs emissions by 4.4% (3.3%-6.1%) CFC-11-equivalent (CFC-11-eq) and 5.4% (4.1%-7.5%) CO2-equivalent (CO2-eq) during 1995-2012. If left uncontrolled, accumulative emissions of HFC-410A will be12.4 (7.1-20.2) CO2-eq Pg during 2015-2050, which can offset the global climate benefits achieved by the Montreal Protocol. The HFC-410A emissions from China's RAC sector are estimated to be of importance to both global HFCs emissions and China's GHG emissions. Further, we probed the emission mitigation performances of the current 2014 North American Proposal scenario and a modified more ambitious scenario. The emissions of two mitigation scenarios are only 28% and 22% of the emissions without mitigation actions, respectively. This study is the first effort to map the transition of eliminated substance HCFC-22 and its alternative HFC-410A in RAC sector. Therefore, alternative chemicals should be scrutinized with cautions before they are promoted and applied.

  16. Influences of different types of magnetic fields on HCFC-141b gas hydrate formation processes

    Institute of Scientific and Technical Information of China (English)

    SHU; Bifen; MA; Xiaolin; GUO; Kaihua; LI; Jianhong

    2004-01-01

    In this study, visualizations and experiments are carried out on the influence of static and rotating magnetic fields on the characteristics of HCFC-141b gas hydrate formation, such as crystallization form, formation temperature and induction time. It has been found that a proper rotating magnetic field can considerably improve the low-pressure gas hydrate formation process,especially in increasing the formation temperature and shortening the induction time. The morphology of the gas hydrate formation appears rather complex and compact. However, a proper static magnetic field can make the gas hydrate crystal more organized, which will be benefit to heat transfer.

  17. Recent Developments in Cooling Using Blowing

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Influence of the blowing through a porous flat plate and a circular cylinder has been studied. Experimental and numerical results agree and show a thickening of the boundary layers, both dynamic and thermal. The thermal protection effectiveness has been quantified for the two geometries, and comparisons between discrete injection and blowing, in the case of the flat plate, were carried out, showing a stronger impact of the latter. Finally, the blowing influence on the primary instability properties results in a decrease of the vortex shedding frequency and a modification of the shear layer.

  18. FEASTING BLACK HOLE BLOWS BUBBLES

    Science.gov (United States)

    2002-01-01

    A monstrous black hole's rude table manners include blowing huge bubbles of hot gas into space. At least, that's the gustatory practice followed by the supermassive black hole residing in the hub of the nearby galaxy NGC 4438. Known as a peculiar galaxy because of its unusual shape, NGC 4438 is in the Virgo Cluster, 50 million light-years from Earth. These NASA Hubble Space Telescope images of the galaxy's central region clearly show one of the bubbles rising from a dark band of dust. The other bubble, emanating from below the dust band, is barely visible, appearing as dim red blobs in the close-up picture of the galaxy's hub (the colorful picture at right). The background image represents a wider view of the galaxy, with the central region defined by the white box. These extremely hot bubbles are caused by the black hole's voracious eating habits. The eating machine is engorging itself with a banquet of material swirling around it in an accretion disk (the white region below the bright bubble). Some of this material is spewed from the disk in opposite directions. Acting like high-powered garden hoses, these twin jets of matter sweep out material in their paths. The jets eventually slam into a wall of dense, slow-moving gas, which is traveling at less than 223,000 mph (360,000 kph). The collision produces the glowing material. The bubbles will continue to expand and will eventually dissipate. Compared with the life of the galaxy, this bubble-blowing phase is a short-lived event. The bubble is much brighter on one side of the galaxy's center because the jet smashed into a denser amount of gas. The brighter bubble is 800 light-years tall and 800 light-years across. The observations are being presented June 5 at the American Astronomical Society meeting in Rochester, N.Y. Both pictures were taken March 24, 1999 with the Wide Field and Planetary Camera 2. False colors were used to enhance the details of the bubbles. The red regions in the picture denote the hot gas

  19. Blowing momentum and duty cycle effect on aerodynamic performance of flap by pulsed blowing

    Science.gov (United States)

    Zhou, Ping; Wang, Yankui; Wang, Jinjun; Sha, Yongxiang

    2017-04-01

    Control surface, which is often located in the trailing edge of wings, is important in the attitude control of an aircraft. However, the efficiency of the control surface declines severely under the high deflect angle of the control surface because of the flow separation. To improve the efficiency of control surface, this study discusses a flow-control technique aimed at suppressing the flow separation by pulsed blowing at the leading edge of the control surface. Results indicated that flow separation over the control surface can be suppressed by pulsed blowing, and the maximum average lift coefficient of the control surface can be 95% times higher than that of without blowing when average blowing momentum coefficient is 0.03 relative to that of without blowing. Finally, this study shows that the average blowing momentum coefficient and non-dimensional frequency of pulsed blowing are two of the key parameters of the pulsed blowing control technique. Otherwise, duty cycle also has influence on the effect of pulsed blowing. Numerical simulation is used in this study.

  20. Exergy analysis of an HCFC-22 and HC-290 operated air conditioning system

    Science.gov (United States)

    Ahamed, Jamal Uddin; Raiyan, Muhammad Ferdous; Salam, Md. Abdus

    2017-06-01

    The present work discusses exergy analysis of a split type air conditioning system. Typical domestic air conditioners use R22 which is a Hydrochloroflurocarbon (HCFC) refrigerant. Due to its destructive impact on ozone layer, search for alternative refrigerants is going on. Propane (R290), a pure Hydrocarbon (HC) is considered here along with R22 to make different blends of refrigerants. Two HCFC-22 and HC-290 mixtures (P1 and P2) were prepared with mass ratios of (R22:R290) 90:10 and 85:15 respectively. Using experimentally obtained data of pressure and temperature, other properties in the vapor compression system were found by REFPROP 7 software. Finally, exergy analysis was done for all the refrigerants (R22, P1 and P2). Exergy destruction in each component was also inspected. Total exergy loss of mixture P2 was found to be greater than the exergy loss of R22 and P1. Variations in exergy losses were observed with respect to evaporator temperature at two different ambient conditions. In all cases, exergy destruction in condenser was found to be the highest among the four main components of the cycle.

  1. Blow-up: A Free Lunch?

    Directory of Open Access Journals (Sweden)

    Jan Koenderink

    2012-02-01

    Full Text Available We consider operations that change the size of images, either shrinks or blow-ups. Image processing offers numerous possibilities, put at everyone's disposal with such computer programs as Adobe Photoshop. We consider a different class of operations, aimed at immediate visual awareness, rather than pixel arrays. We demonstrate cases of blow-ups that do not sacrifice apparent resolution. This apparent information gain is due to “amodal occlusion.”

  2. PIV Measurements on a Blowing Flap

    Science.gov (United States)

    Hutcheson, Florence V.; Stead, Daniel J.

    2004-01-01

    PIV measurements of the flow in the region of a flap side edge are presented for several blowing flap configurations. The test model is a NACA 63(sub 2)-215 Hicks Mod-B main-element airfoil with a half-span Fowler flap. Air is blown from small slots located along the flap side edge on either the top, bottom or side surfaces. The test set up is described and flow measurements for a baseline and three blowing flap configurations are presented. The effects that the flap tip jets have on the structure of the flap side edge flow are discussed for each of the flap configurations tested. The results indicate that blowing air from a slot located along the top surface of the flap greatly weakened the top vortex system and pushed it further off the top surface. Blowing from the bottom flap surface kept the strong side vortex further outboard while blowing from the side surface only strengthened the vortex system or accelerated the merging of the side vortex to the flap top surface. It is concluded that blowing from the top or bottom surfaces of the flap may lead to a reduction of flap side edge noise.

  3. Performance of a split-type air conditioner matched with coiled adiabatic capillary tubes using HCFC22 and HC290

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Guobing [School of Energy and Power Engineering, North China Electric Power University, Beijing 102206 (China); Zhang, Yufeng [School of Environmental Science and Engineering, Tianjin University, Tianjin 300072 (China)

    2010-05-15

    This paper experimentally investigated the system performance of a split-type air conditioner matching with different coiled adiabatic capillary tubes for HCFC22 and HC290. Experiments were carried out in a room-type calorimeter. The results have shown that (1) similar cooling effects can be achieved by matching various capillary tubes of different inner diameters; (2) parallel capillary tubes presented better system performance and flow stability with weaker inlet pressure fluctuations than the single capillary tube; (3) with the coil diameter of the capillary tube increasing from 40 mm to 120 mm, the mass flow rate tended to increase slightly. But the cooling capacity, input power and energy efficiency ratio (EER) did not show evident tendency of change; (4) the refrigerant charge and mass flow rate for HC290 were only 44% and 47% of that for HCFC22, respectively, due to the much lower density. And HC290 had 4.7-6.7% lower cooling capacity and 12.1-12.3% lower input power with respect to HCFC22. However, the EER of HC290 can be 8.5% higher than that of HCFC22, which exhibits the advantage of using HC290. In addition, the experimental uncertainties were analyzed and some application concerns of HC290 were discussed. (author)

  4. 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.

  5. Global HCFC-22 measurements with MIPAS: retrieval, validation, climatologies and trends

    Directory of Open Access Journals (Sweden)

    M. Chirkov

    2015-05-01

    Full Text Available We report on HCFC-22 data acquired by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS in reduced spectral resolution nominal mode in the period from January 2005 to April 2012 from version 5.02 level-1b spectral data and covering an altitude range from the upper troposphere (above cloud top altitude to about 50 km. The profile retrieval was performed by constrained nonlinear least squares fitting of measured limb spectral radiances to modelled spectra. The spectral ν4-band at 816.5 ± 13 cm−1 was used for the retrieval. A Tikhonov-type smoothing constraint was applied to stabilise the retrieval. In the lower stratosphere, we find a global volume mixing ratio of HCFC-22 of about 185 pptv in January 2005. The linear growth rate in the lower latitudes lower stratosphere was about 6 to 7 pptv yr−1 in the period 2005–2012. The obtained profiles were compared with ACE-FTS satellite data v3.5, as well as with MkIV balloon profiles and in situ cryosampler balloon measurements. Between 13 and 22 km, average agreement within −3 to +5 pptv (MIPAS–ACE with ACE-FTS v3.5 profiles is demonstrated. Agreement with MkIV solar occultation balloon-borne measurements is within 10–20 pptv below 30 km and worse above, while in situ cryosampler balloon measurements are systematically lower over their full altitude range by 15–50 pptv below 24 km and less than 10 pptv above 28 km. Obtained MIPAS HCFC-22 time series below 10 km altitude are shown to agree mostly well to corresponding time series of near-surface abundances from NOAA/ESRL and AGAGE networks, although a more pronounced seasonal cycle is obvious in the satellite data, probably due to tropopause altitude fluctuations and subsidence of polar winter stratospheric air into the troposphere. A parametric model consisting of constant, linear, quasi-biennial oscillation (QBO and several sine and cosine terms with different periods has been fitted to the temporal variation of

  6. Effects of magnetic fields on HCFC-141b refrigerant gas hydrate formation

    Institute of Scientific and Technical Information of China (English)

    刘勇; 郭开华; 梁德青; 樊栓狮

    2003-01-01

    Low-pressure refrigerant gas hydrates have brilliant prospects as a cool storage medium for air-conditioning systems. Intensive effects of some specific magnetic fields on the formation process of HCFC-141b refrigerant gas hydrate are depicted experimentally. Under influence of these specific magnetic fields, the orientation and growth region of gas hydrate are altered; induction time of hydrate crystallization can be shortened extremely, and it can be shortened to 40 min from 9 h; hydrate formation mass can be enhanced considerably, and hydration rate can arrive at 100% in some instances. Meanwhile, the relations of induction time and hydration rate changed with magnetic field intensity are depicted, and some elementary regulations are found.

  7. Black Hole Blows Big Bubble

    Science.gov (United States)

    2010-07-01

    Combining observations made with ESO's Very Large Telescope and NASA's Chandra X-ray telescope, astronomers have uncovered the most powerful pair of jets ever seen from a stellar black hole. This object, also known as a microquasar, blows a huge bubble of hot gas, 1000 light-years across, twice as large and tens of times more powerful than other known microquasars. The discovery is reported this week in the journal Nature. "We have been astonished by how much energy is injected into the gas by the black hole," says lead author Manfred Pakull. "This black hole is just a few solar masses, but is a real miniature version of the most powerful quasars and radio galaxies, which contain black holes with masses of a few million times that of the Sun." Black holes are known to release a prodigious amount of energy when they swallow matter. It was thought that most of the energy came out in the form of radiation, predominantly X-rays. However, the new findings show that some black holes can release at least as much energy, and perhaps much more, in the form of collimated jets of fast moving particles. The fast jets slam into the surrounding interstellar gas, heating it and triggering an expansion. The inflating bubble contains a mixture of hot gas and ultra-fast particles at different temperatures. Observations in several energy bands (optical, radio, X-rays) help astronomers calculate the total rate at which the black hole is heating its surroundings. The astronomers could observe the spots where the jets smash into the interstellar gas located around the black hole, and reveal that the bubble of hot gas is inflating at a speed of almost one million kilometres per hour. "The length of the jets in NGC 7793 is amazing, compared to the size of the black hole from which they are launched," says co-author Robert Soria [1]. "If the black hole were shrunk to the size of a soccer ball, each jet would extend from the Earth to beyond the orbit of Pluto." This research will help

  8. Falling liquid films with blowing and suction

    CERN Document Server

    Thompson, Alice B; Papageorgiou, Demetrios T

    2015-01-01

    Flow of a thin viscous film down a flat inclined plane becomes unstable to long wave interfacial fluctuations when the Reynolds number based on the mean film thickness becomes larger than a critical value (this value decreases as the angle of inclination with the horizontal increases, and in particular becomes zero when the plate is vertical). Control of these interfacial instabilities is relevant to a wide range of industrial applications including coating processes and heat or mass transfer systems. This study considers the effect of blowing and suction through the substrate in order to construct from first principles physically realistic models that can be used for detailed passive and active control studies of direct relevance to possible experiments. Two different long-wave, thin-film equations are derived to describe this system; these include the imposed blowing/suction as well as inertia, surface tension, gravity and viscosity. The case of spatially periodic blowing and suction is considered in detail...

  9. Solution blowing of soy protein fibers.

    Science.gov (United States)

    Sinha-Ray, S; Zhang, Y; Yarin, A L; Davis, S C; Pourdeyhimi, B

    2011-06-13

    Solution blowing of soy protein (sp)/polymer blends was used to form monolithic nanofibers. The monolithic fibers were blown from blends of soy protein and nylon-6 in formic acid. The sp/nylon-6 ratio achieved in dry monolithic nanofibers formed using solution blowing of the blend was equal to 40/60. In addition, solution blowing of core-shell nanofibers was realized with soy protein being in the core and the supporting polymer in the shell. The shells were formed from nylon-6. The sp/nylon-6 ratio achieved in dry core-shell fibers was 32/68. The nanofibers developed in the present work contain significant amounts of soy protein and hold great potential in various applications of nonwovens.

  10. Potentiation of 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123)-induced liver toxicity by ethanol in guinea-pigs

    Energy Technology Data Exchange (ETDEWEB)

    Hoet, Perrine; Buchet, Jean-Pierre; Haufroid, Vincent; Lison, Dominique [Universite Catholique de Louvain, Faculty of Medicine, Industrial Toxicology and Occupational Medicine Unit, Clos Chapelle-aux-Champs, 30-54, 1200 Brussels (Belgium); Sempoux, Christine; Rahier, Jacques [Cliniques Universitaires St Luc, Department of Pathology, 1200 Brussels (Belgium)

    2002-12-01

    HCFC-123 (2,2-dichloro-1,1,1-trifluoroethane), a substitute for the banned chlorofluorocarbons (CFCs), is a structural analogue of the well-known hepatotoxicant halothane. The objectives of these experiments were to investigate (1) whether, like halothane, multiple exposure increases the risk of HCFC-123-induced liver toxicity, and (2) whether ethanol, a potent CYP2E1 inducer, potentiates the liver toxicity of HCFC-123. In experiment 1, male Hartley guinea-pigs were exposed twice a week to 5000 ppm HCFC-123 (4 h) during 3 weeks followed by 2 weeks recovery, and then re-exposed or not during 4 h to 5000 ppm HCFC-123. A group with a single exposure to 5000 ppm HCFC-123 and a control group were also included. In experiment 2, guinea-pigs received 5 or 10% ethanol in drinking water during 12 days before a single 4-h exposure to 5000 ppm HCFC-123. A group receiving 10% only, a group exposed once to 5000 ppm HCFC-123 but not pre-treated with ethanol and a control group were also included. In both experiments, the liver toxicity was assessed, 24 h post-exposure, by the serum activities of alanine aminotransferase (ALT) and isocitrate dehydrogenase (ICDH) as well as by histopathology. In experiment 2 the urinary excretion rate of the main metabolites trifluoroacetic acid (TFA) and chlorodifluoroacetic acid (CDFA) was assessed and CYP2E1 activity was measured by the chlorzoxazone metabolic ratio. Multiple exposure to 5000 ppm HCFC-123 did not cause greater liver damage than a single exposure (ALT, ICDH 3-fold control values). At this level of exposure the liver lesions were totally reversible within two weeks. Ethanol consumption produced CYP2E1 induction, increased urinary excretion of both HCFC-123 metabolites (more than 2-fold the rate measured in the non-induced group) and markedly increased the liver toxicity of HCFC-123 as shown by the serum liver enzyme activities (ALT 8.5-fold increase, ICDH 13-fold increase), and the histopathology. The necrosis was predominantly

  11. Compact heterotic orbifolds in blow-up

    CERN Document Server

    Nibbelink, Stefan Groot; Plöger, Felix; Trapletti, Michele; Vaudrevange, Patrick K S

    2008-01-01

    We compare heterotic string models on orbifolds with supergravity models on smooth compact spaces, obtained by resolving the orbifold singularities. Our main focus is on heterotic E8xE8 models on the resolution of the compact T^6/Z_3 orbifold with Wilson lines. We explain how different gauge fluxes at various resolved fixed points can be interpreted in blow down as Wilson lines. Even when such Wilson lines are trivial from the orbifold perspective, they can still lead to additional symmetry breaking in blow-up. Full agreement is achieved between orbifold and resolved models, at the level of gauge interactions, massless spectrum and anomaly cancellation. In this matching the blow-up modes are of crucial importance: they play the role of model-dependent axions involved in the cancellation of multiple anomalous U(1)'s on the resolution. We illustrate various aspects by investigating blow-ups of a Z_3 MSSM model with two Wilson lines: if all its fixed points are resolved simultaneously, the SM gauge group is nece...

  12. Blow-up: A free lunch?

    NARCIS (Netherlands)

    Koenderink, J.J.; Richards, W.; Van Doorn, A.J.

    2012-01-01

    We consider operations that change the size of images, either shrinks or blow-ups. Image processing offers numerous possibilities, put at everyone’s disposal with such computer programs as Adobe Photoshop. We consider a different class of operations, aimed at immediate visual awareness, rather than

  13. Blow-up: A free lunch?

    NARCIS (Netherlands)

    Koenderink, J.J.; Richards, W.; Van Doorn, A.J.

    2012-01-01

    We consider operations that change the size of images, either shrinks or blow-ups. Image processing offers numerous possibilities, put at everyone’s disposal with such computer programs as Adobe Photoshop. We consider a different class of operations, aimed at immediate visual awareness, rather than

  14. Export of ADC Blowing Agents Increases Rapidly

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Gradual capacity expansion and fierce market competition ADC blowing agents (azodicarbonamide) are mainly used in packaging materials, construction materials (mainly heat-insulation materials, high-grade wallpaper and UPVC (unplasticized polyvinyl chloride) pipes), EVA (ethylene-vinyl acetate copolymer) shoe soles and PVC (polyvinyl chloride) artificial leather.

  15. Asian elephants acquire inaccessible food by blowing.

    Science.gov (United States)

    Mizuno, Kaori; Irie, Naoko; Hiraiwa-Hasegawa, Mariko; Kutsukake, Nobuyuki

    2016-01-01

    Many animals acquire otherwise inaccessible food with the aid of sticks and occasionally water. As an exception, some reports suggest that elephants manipulate breathing through their trunks to acquire inaccessible food. Here, we report on two female Asian elephants (Elephas maximus) in Kamine Zoo, Japan, who regularly blew to drive food within their reach. We experimentally investigated this behaviour by placing foods in inaccessible places. The elephants blew the food until it came within accessible range. Once the food was within range, the elephants were increasingly less likely to blow as the distance to the food became shorter. One subject manipulated her blowing duration based on food distance: longer when the food was distant. These results suggest that the elephants used their breath to achieve goals: that is, they used it not only to retrieve the food but also to fine-tune the food position for easy grasping. We also observed individual differences in the elephants' aptitude for this technique, which altered the efficiency of food acquisition. Thus, we added a new example of spontaneous behaviour for achieving a goal in animals. The use of breath to drive food is probably unique to elephants, with their dexterous trunks and familiarity with manipulating the act of blowing, which is commonly employed for self-comfort and acoustic communication.

  16. Assessing the Atmospheric Impact of CF3CClH2 (HCFC-133a): Laboratory Measurements of OH Kinetics and UV and Infrared Absorption Spectra Combined with Model Calculations

    Science.gov (United States)

    McGillen, M.; Bernard, F.; Fleming, E. L.; Jackman, C. H.; Burkholder, J. B.

    2014-12-01

    CF3CClH2 (HCFC-133a) was recently detected in the atmosphere and its atmospheric mixing ratio has quadrupled over the last 10 years. As expected for this class of compound, HCFC-133a is both an ozone-depleting substance and a greenhouse gas. Precise knowledge of its atmospheric degradation and radiative efficiency is critical to understanding its effect upon the atmosphere. The predominant atmospheric loss process for HCFC-133a is via reaction with the OH radical, where the rate coefficient for this reaction is poorly constrained, especially below room temperature. UV photolysis is a minor loss process, although large discrepancies exist among the reported spectrum measurements. The infrared spectrum of HCFC-133a is presently not available in the literature. The primary focus of this work was to reduce the uncertainties in the atmospheric loss processes of HCFC-133a and its radiative efficiency. Rate coefficient measurements for the OH + HCFC-133a reaction over the temperature range 233-397 K will be reported. In addition, UV absorption spectrum measurements over the wavelength (184.95-240 nm) and temperature (213-323 K) ranges and infrared absorption measurements from 500-4000 cm-1 will be reported. These results are used in 2-D atmospheric model calculations to quantify the atmospheric loss processes, atmospheric lifetime, ozone depletion potential, radiative efficiency, and global warming potential of HCFC-133a. These important metrics will enable informed policy decisions regarding HCFC-133a.

  17. Estimated HCFC-22 emissions for 1990-2050 in China and the increasing contribution to global emissions

    Science.gov (United States)

    Li, Zhifang; Bie, Pengju; Wang, Ziyuan; Zhang, Zhaoyang; Jiang, Hanyu; Xu, Weiguang; Zhang, Jianbo; Hu, Jianxin

    2016-05-01

    Chlorodifluoromethane (CHClF2, HCFC-22) is a widely used refrigerant and foaming agent that is not only an ozone-depleting substance (ozone depletion potential (ODP), 0.04) but also a greenhouse gas (global warming potential (GWP), 1780). A comprehensive historical emission inventory for 1990-2014 was produced using a bottom-up method, and a projection through to 2050 was made for China. The results demonstrated that historical emissions increased sharply from 0.2 Gg/yr in 1990 to 127.2 Gg/yr in 2014. Room air-conditioners (RACs), industrial and commercial refrigeration (ICR), and extruded polystyrene (XPS) were three primary emission sources, and accounted for an average of 95.4% of the total emissions over the period studied. The percentage of global HCFC-22 emissions originating from China significantly increased from 0.1% in 1990 to 31.6% in 2012, with an average growth rate of 1.4% per year. Under the Montreal Protocol phasing-out (MPPO) scenario, future emissions were expected to reach a peak of 133.5 Gg/yr in 2016 and then continuously decline to 10.2 Gg/yr in 2050. The accumulative reduction for 2015-2050 would be 5533.8 Gg (equivalent to 221.4 CFC-11-eq Gg and 9850.1 CO2-eq Tg), which is approximately equivalent to the total CO2 emission for China in 2012 (9900 Tg) (Olivier et al., 2013), compared with the no Montreal Protocol scenario (NMP). Under the MPPO scenario, two cases were analyzed to explore the future emission ranges in China. A comparison between the two cases implied that the choice of emission reduction policy will have a considerable impact on HCFC-22 emissions.

  18. Development of an Automatic Blowing Snow station

    Science.gov (United States)

    Nishimura, K.

    2010-12-01

    On the Antarctic ice sheet, strong katabatic winds blow throughout the year and a large but unknown fraction of the snow which falls on it is removed continuously. This constitutes a significant factor in mass and energy balance and is all the more important when predicting the likely effects of global climate change. Further, recent experimental work has indicated that the snowdrift sublimation can lead to significant mass losses during strong winds and can be also an important factor in the surface mass balance of the Antarctic ice sheets. Nishimura and Nemoto (2005) carried out the blowing snow observations at Mizuho station, Antarctica in 2000 with the snow particle counters (SPC) that can sense not only the number of snow particles but also their diameters. SPC worked properly and the data obtained revealed profiles of mass flux and particle size distributions as a function of the friction velocity. However, the SPC requires rather high power supply and the data is stored in PC; it is not always suitable for the unmanned observations under the severe Antarctic conditions. Thus, we have developed a simpler device by measuring the attenuation of the light intensity, which strongly depends on the blowing snow flux. A small wind turbine and a cold-proof buttery were utilized as a power source. Firstly, its performance was tested with comparing the SPC in a cold wind tunnel system and it proved adequately fit for practical use by combining the output of the anemometer. In 2009/2010 winter, three systems have been set at Ishikari, Col du Lac blanc in France, and S17 near Syowa station in Antarctica, and the tests are still continuing.

  19. Gastric blow-out: komplikation efter fedmekirurgi

    DEFF Research Database (Denmark)

    Torrens, Ayoe Sabrina; Born, Pernille Wolder; Naver, Lars

    2009-01-01

    Laparoscopic gastric bypass is the most common type of surgery for morbid obesity in Denmark. The most frequent late complications after gastric bypass are ulcer, internal hernia and stenosis. Two cases of stenosis of the bileopancreatic limb with gastric blow-out are described. Urgent diagnosis...... with computed tomography and acute surgical treatment is vital as the complication can lead to gastric necrosis, pancreatitis, biliary stasis, sepsis and multi-organ failure within a very short time. Prompt contact to specialized surgeons is advocated. Udgivelsesdato: 2009-Nov...

  20. Blow-up in nonlinear Schroedinger equations. II. Similarity structure of the blow-up singularity

    DEFF Research Database (Denmark)

    Rypdal, K.; Juul Rasmussen, Jens

    1986-01-01

    invariance and generalizations of the latter. This generalized "quasi-invariance" reveals the nature of the blow-up singularity and resolves an old controversy. Most of the previous work has been done on the cubic nonlinearity. We generalize the results to an arbitrary power nonlinearity....

  1. Simultaneous and non-simultaneous blow-up and uniform blow-up profiles for reaction-diffusion system

    Directory of Open Access Journals (Sweden)

    Zhengqiu Ling

    2012-11-01

    Full Text Available This article concerns the blow-up solutions of a reaction-diffusion system with nonlocal sources, subject to the homogeneous Dirichlet boundary conditions. The criteria used to identify simultaneous and non-simultaneous blow-up of solutions by using the parameters p and q in the model are proposed. Also, the uniform blow-up profiles in the interior domain are established.

  2. Film condensation of HCFC-123 on in-line bundles of horizontal finned tubes. Effect of fin geometry. Suihei fin tsuki kan no gobanme kangun ni okeru HCFC-123 no gyoshuku. Fin keijo no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Honda, H.; Takamatsu, H.; Takada, N. (Kyushu University, Fukuoka (Japan). Institute of Advanced Material Study); Kim, K. (Kyushu University, Fukuoka (Japan)); Ishikawa, Y. (Otsuka Pharmaceutical Co. Ltd., Tokyo (Japan))

    1994-06-25

    Theoretical analysis and experiments were carried out in regard to the condensation of HCFC-123 vapor on a horizontal finned tube. The previous paper described the theoretical analysis on the film condensation in a tube nest with low-fins. In this study, approximate expressions of heat transfer coefficient for a newly proposed high-performance finned tubes are suggested and compared with the experimental results. In the test, HCFC-123 vapor was flowed from the upper part of the tube nest arranged in squares of 3 rows and 15 layers (tube pitch: 22mm), and was condensed on the tube surface. The liquid film formation was observed, and the heat transfer properties were measured. Two kinds of conventional low-fin tubes and two kinds of finned tubes of which shape is similar to the newly proposed ones were tested. One of the new finned tubes showed the highest heat transfer performance, which was about 85% higher than that of the conventional low-fin (26 fpi) tube. The theoretical model for condensation in the previous paper was correspondent with the experimental data at low vapor speed and low condensate inundation rate. 14 refs., 14 figs., 4 tabs.

  3. THIRD-GENERATION FOAM BLOWING AGENTS FOR FOAM INSULATION

    Science.gov (United States)

    The report gives results of a study of third-generation blowing agents for foam insulation. (NOTE: the search for third-generation foam blowing agents has led to the realization that, as the number of potential substitutes increases, new concerns, such as their potential to act a...

  4. Blow Up in Finite Time for the Zakharov System

    Institute of Scientific and Technical Information of China (English)

    甘在会; 郭柏灵

    2009-01-01

    @@ In [1],Merle guessed that the solution of Zakharov system always blows up in finite time.In accordance with the guess,in this paper we study the finite time blow-up results for the solution to the Cauchy problem of the generalized Zakharov system with combined power-type nonlinearities in R3:

  5. Investigation of Airfoil Aeroacoustics with Blowing Control Mechanism

    Directory of Open Access Journals (Sweden)

    Baha ZAFER

    2016-11-01

    Full Text Available In this investigation, it is dealt with computational aero-acoustic analysis of an airfoil with jet blowing. The airfoil shape is selected as NACA0015 profile with jet blowing on upper surface. The calculations of analysis are done by using commercial finite volume solver. The k-ε turbulence model is used for the turbulence modeling and the Ffowcs Williams and Hawking acoustic analogy model is run for determination of acoustic data. The numerical results are compared with experimental data for computed Sound Pressure Level without jet blowing and well agreement is observed. In the case of jet blowing, the effects of different jet angle, velocity ratio and angle of attack on airfoil are investigated and noise levels of non jet cases and jet blowing cases are studied.

  6. Advanced Trailing Edge Blowing Concepts for Fan Noise Control

    Directory of Open Access Journals (Sweden)

    Cezar RIZEA

    2012-03-01

    Full Text Available This study documents trailing edge blowing research performed to reduce rotor / stator interaction noise in turbofan engines. The existing technique of filling every velocity deficit requires a large amount of air and is therefore impractical. The purpose of this research is to investigate new blowing configurations in order to achieve noise reduction with lesser amounts of air. Using the new configurations air is not injected into every fan blade, but is instead varied circumferentially. For example, blowing air may be applied to alternating fan blades. This type of blowing configuration both reduces the amount of air used and changes the spectral shape of the tonal interaction noise. The original tones at the blade passing frequency and its harmonics are reduced and new tones are introduced between them. This change in the tonal spectral shape increases the performance of acoustic liners used in conjunction with trailing edge blowing.

  7. New Device for Characterisation of Thermoforming and Blow Moulding Materials by Membrane Inflation

    DEFF Research Database (Denmark)

    Kjær, Erik Michael; Lauridsen, Carsten Linding

    1998-01-01

    New Device for Characterisation of Thermoforming and Blow Moulding Materials by Membrane Inflation......New Device for Characterisation of Thermoforming and Blow Moulding Materials by Membrane Inflation...

  8. New Device for Characterisation of Thermoforming and Blow Moulding Materials by Membrane Inflation

    DEFF Research Database (Denmark)

    Kjær, Erik Michael; Lauridsen, Carsten Linding

    1998-01-01

    New Device for Characterisation of Thermoforming and Blow Moulding Materials by Membrane Inflation......New Device for Characterisation of Thermoforming and Blow Moulding Materials by Membrane Inflation...

  9. Pulsed single-blow regenerator testing

    Science.gov (United States)

    Oldson, J. C.; Knowles, T. R.; Rauch, J.

    1992-01-01

    A pulsed single-blow method has been developed for testing of Stirling regenerator materials performance. The method uses a tubular flow arrangement with a steady gas flow passing through a regenerator matrix sample that packs the flow channel for a short distance. A wire grid heater spanning the gas flow channel is used to heat a plug of gas by approximately 2 K for approximately 350 ms. Foil thermocouples monitor the gas temperature entering and leaving the sample. Data analysis based on a 1D incompressible-flow thermal model allows the extraction of Stanton number. A figure of merit involving heat transfer and pressure drop is used to present results for steel screens and steel felt. The observations show a lower figure of merit for the materials tested than is expected based on correlations obtained by other methods.

  10. Bernoulli Suction Effect on Soap Bubble Blowing?

    Science.gov (United States)

    Davidson, John; Ryu, Sangjin

    2015-11-01

    As a model system for thin-film bubble with two gas-liquid interfaces, we experimentally investigated the pinch-off of soap bubble blowing. Using the lab-built bubble blower and high-speed videography, we have found that the scaling law exponent of soap bubble pinch-off is 2/3, which is similar to that of soap film bridge. Because air flowed through the decreasing neck of soap film tube, we studied possible Bernoulli suction effect on soap bubble pinch-off by evaluating the Reynolds number of airflow. Image processing was utilized to calculate approximate volume of growing soap film tube and the volume flow rate of the airflow, and the Reynolds number was estimated to be 800-3200. This result suggests that soap bubbling may involve the Bernoulli suction effect.

  11. Blow up Analysis for Anomalous Granular Gases

    CERN Document Server

    Rey, Thomas

    2011-01-01

    We investigate in this article the long-time behaviour of the solutions to the energy-dependent, spatially-homogeneous, inelastic Boltzmann equation for hard spheres. This model describes a diluted gas composed of hard spheres under statistical description, that dissipates energy during collisions. We assume that the gas is "anomalous", in the sense that the energy dissipation increases when the temperature decreases. This allows the gas to cool down in finite time. We study the existence, uniqueness and attractiveness of blow up profiles for this model and the cooling law associated, generalizing the classical Haff's Law for granular gases. To this end, we give some new estimates about the third order moment of the inelastic Boltzmann equation with drift term and we introduce new strongly "non-linear" self-similar variables

  12. Film condensation of HCFC-123 on staggered bundles of horizontal finned tubes. Effect of fin geometry; Suihei fintsukikan no chidori kanbun ni okeru HCFC-123 no gyoshuku. Fin keijo no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Honda, H.; Takamatsu, H.; Takada, N. [Kyushu University, Fukuoka (Japan). Institute of Advanced Material Study; Makishi, O. [Kyushu University, Fukuoka (Japan); Sejimo, H. [NKK Corp., Tokyo (Japan)

    1995-03-25

    Experiments were conducted to obtain row-by-row heat transfer data during condensation of downward flowing HCFC-123 vapor in staggered bundles of horizontal two-dimensional fin tubes. Two conventional low fin tubes and two finned tubes with fin shapes close to that of a new high-performance fin proposed by Zhu and Honda were tested. The latter tubes had fin dimensions that were optimized by theoretical analysis. The heat transfer characteristics were compared with previous results for in-line bundles of the same test tubes and with theoretical predictions for stagnant vapor. The decrease in heat transfer due to condensate inundation was less significant for the staggered tube bundle. The highest heat transfer coefficient was provided by the staggered bundle of one of the new finned tubes. The theoretical predictions compared well with experimental data at a low vapor velocity and a low to medium condensate inundation rate. 15 refs., 10 figs., 2 tabs.

  13. 管束效应对HFC245fa与HCFC123膜状凝结换热影响%Effect of Inundation on Film Condensation of HFC245fa and HCFC123 on Horizontal Tubes

    Institute of Scientific and Technical Information of China (English)

    马志先; 张吉礼; 孙德兴

    2012-01-01

    建立试验系统、改进试验方法,试验研究HFC245fa与HCFC123在光管与3种强化换热管(2D-A,3D-A与3D-B)管束外冷凝换热特性.试验管束由4列排深为5排的列管构成,换热管公称外径为19.05 mm、有效换热长度为500 mm.试验中,利用改进的Wilson图解法获得水侧对流传热系数,通过轮转试验方法消除管束试验中各试验管换热本构差异等因素对管束效应测试分析的影响.试验结果表明,Kern模型预测值与HFC245fa与HCFC123光管管束外凝结换热结果偏差随试验热通量升高而增大;管束效应对光管与三维表面强化管(3D-B)凝结换热影响比其对二维表面低肋管(2D-A)影响显著;管束效应对HFC245fa在3D-B管外凝结换热影响在n>3后超过Nusselt管束模型预测值;HFC245fa在3D-B管束外凝结换热性能随管排深度的变化规律与其在光管管束外的变化规律及Nusselt模型显示规律明显不同.%A test facility was constructed to perform shell-side condensation testing, and test results are presented for HFC245fa and HCFC123 using horizontal tube bundles (4 lines×5 rows) consist of smooth tubes and 2D-A, 3D-A and 3D-B enhanced tubes. Effect of inundation on the condensation heat transfer coefficient (CHTC) is considered in the study. The nominal diameter of test tubes is 19.05 mm and the active length of the test section is 500 mm. In the experiment, water-side convection heat transfer coefficient of enhanced tube was gained by modified Wilson plot method and the tube row effect is studied by a designed method with high precision. The results show that the deviation between CHTC of HCFC123 and HFC245fa on smooth tube bundle and that predicted by Kern's model increased with the increase of heat flow rate; Inundation effect significantly affects CHTC of smooth and 3D-B tubes, but lightly affects that of 2D-A tubes; Inundation effect of HFC245fa on 3D-B tubes is more severity than that predicted by Nusselt model for

  14. CT findings of orbital blow-out fracture

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jeong Yeol; Park, Jun Kyun; Lim, Woo Young; Rho, Kwang Suk; Ko, Yong Suk; Kim, Young Chul; Oh, Jae Hee [Chosun Univ., Kwangju (Korea, Republic of). Coll. of Medicine

    1998-02-01

    To evaluate the usefulness and radiologic findings of CT in the diagnosis of orbital blow-out fracture. Forty-four patients with orbital blow-out fractures diagnosed by clinical findings and CT were evaluated retrospectively. On CT images, we evaluated the site and frequency of fracture, herniation of orbital fat, extraocular muscle abnormality, intraorbital hematoma, and intrasinus hemorrhage. CT is a useful diagnostic modality for the evaluation of orbital blow-out fracture and associated soft tissue abnormalities. (author). 16 refs., 1 tab., 2 figs.

  15. TOTAL VERSUS SINGLE POINT BLOW-UP SOLUTIONS FOR A SEMILINEAR PARABOLIC EQUATION

    Institute of Scientific and Technical Information of China (English)

    Yang Ming

    2007-01-01

    In this paper, we investigate the blow-up set of solutions of a parabolic equation with localized and non-localized reactions. We completely classify blow-up solutions into total blow-up cases and single point blow-up cases.

  16. Blow-up solutions for L 2 supercritical gKdV equations with exactly k blow-up points

    Science.gov (United States)

    Lan, Yang

    2017-08-01

    In this paper we consider the slightly L 2-supercritical gKdV equations \\partialt u+(uxx+u\\vert u\\vert p-1)_x=0 , with the nonlinearity 5 and 0L 2-supercritical gKdV equations. Such solutions can be viewed as solutions with a single blow-up point. In this paper we will prove the existence of solutions with multiple blow-up points, and give a description of the formation of the singularity near the blow-up time.

  17. Treatment Costs Can Be Another Blow to Cancer Patients

    Science.gov (United States)

    ... Costs Can Be Another Blow to Cancer Patients Obamacare has improved access to therapies, but finances are ... under the Affordable Care Act, also known as Obamacare, expenses such as deductibles, co-pays and co- ...

  18. Heterotic Mini-landscape in blow-up

    CERN Document Server

    Bizet, Nana Geraldine Cabo

    2013-01-01

    Localization properties of fields in compact extra dimensions are crucial ingredients for string model building, particularly in the framework of orbifold compactifications. Realistic models often require a slight deviation from the orbifold point, that can be analyzed using field theoretic methods considering (singlet) fields with nontrivial vacuum expectation values. Some of these fields correspond to blow-up modes that represent the resolution of orbifold singularities. Improving on previous analyses we give here an explicit example of the blow-up of a model from the heterotic Mini-landscape. An exact identification of the blow-up modes at various fixed points and fixed tori with orbifold twisted fields is given. We match the massless spectra and identify the blow-up modes as non-universal axions of compactified string theory. We stress the important role of the Green-Schwarz anomaly polynomial for the description of the resolution of orbifold singularities.

  19. CFC-11, CFC-12 and HCFC-22 ground-based remote sensing FTIR measurements at Réunion Island and comparisons with MIPAS/ENVISAT data

    Science.gov (United States)

    Zhou, Minqiang; Vigouroux, Corinne; Langerock, Bavo; Wang, Pucai; Dutton, Geoff; Hermans, Christian; Kumps, Nicolas; Metzger, Jean-Marc; Toon, Geoff; De Mazière, Martine

    2016-11-01

    Profiles of CFC-11 (CCl3F), CFC-12 (CCl2F2) and HCFC-22 (CHF2Cl) have been obtained from Fourier transform infrared (FTIR) solar absorption measurements above the Saint-Denis (St Denis) and Maïdo sites at Réunion Island (21° S, 55° E) with low vertical resolution. FTIR profile retrievals are performed by the well-established SFIT4 program and the detail retrieval strategies along with the systematic/random uncertainties of CFC-11, CFC-12 and HCFC-22 are discussed in this study. The FTIR data of all three species are sensitive to the whole troposphere and the lowermost stratosphere, with the peak sensitivity between 5 and 10 km. The ground-based FTIR data have been compared with the collocated Michelson Interferometer for Passive Atmospheric Sounding (MIPAS/ENVISAT) data and found to be in good agreement: the observed mean relative biases and standard deviations of the differences between the smoothed MIPAS and FTIR partial columns (6-30 km) are (-4.3 and 4.4 %), (-2.9 and 4.6 %) and (-0.7 and 4.8 %) for CFC-11, CFC-12 and HCFC-22, respectively, which are within the combined error budgets from both measurements. The season cycles of CFC-11, CFC-12 and HCFC-22 from FTIR measurements and MIPAS data show a similar variation: concentration is highest in February-April and lowest in August-October. The trends derived from the combined St Denis and Maïdo FTIR time series are -0.86 ± 0.12 and 2.84 ± 0.06 % year-1 for CFC-11 and HCFC-22, respectively, for the period 2004 to 2016, and -0.76 ± 0.05 % year-1 for CFC-12 for 2009 to 2016. These measurements are consistent with the trends observed by the National Oceanic and Atmospheric Administration (NOAA) Global Monitoring Division's (GMD) Halocarbons & other Atmospheric Trace Species Group (HATS) measurements at Samoa (14.2° S, 170.5° W) for CFC-11 (-0.87 ± 0.04 % year-1), but slightly weaker for HCFC-22 (3.46 ± 0.05 %) year-1 and stronger for CFC-12 (-0.60 ± 0.02 % year-1).

  20. LS1 Report: Blowing away the cobwebs

    CERN Multimedia

    Anaïs Schaeffer

    2014-01-01

    With the pressure tests now complete (see here), we are coming to the equally important phase of cleaning the machine. With all the work performed over the past year, quite a lot of dust and dirt has accumulated in certain areas of the accelerator.   Result of the flushing performed in 2007 in Sector 5-6... This year, in Sector 6-7, the filters were particularly clean. A simple and efficient solution, known as helium flushing, has been devised by the Cryogenics group (TE-CRG) to clean up these areas. “We circulate helium gas around the machine in both the cryogenic distribution lines and the magnets,” explains Gérard Ferlin, who is responsible for the flushing operations. “This blows all the debris into a filter at the outlet. ” The flow-rate needs to be high enough to ensure that everything is swept away, so the helium is injected at rates of between 15 and 40 metres per second, much higher than in normal operation. “There&rs...

  1. Polypropylenes foam consisting of thermally expandable microcapsule as blowing agent

    Science.gov (United States)

    Jeoung, Sun Kyung; Hwang, Ye Jin; Lee, Hyun Wook; Kwak, Sung Bok; Han, In-Soo; Ha, Jin Uk

    2016-03-01

    The structure of thermally expandable microcapsule (TEMs) is consisted of a thermoplastic shell which is filled with liquid hydrocarbon at core. The shell of TEMs becomes soft when the temperature is higher than boiling temperature of liquid hydrocarbon. The shell of TEMs is expanded under the high temperature because the inner pressure of TEMs is increased by vaporization of hydrocarbon core. Therefore, the TEMs are applicable for blowing agents and light weight fillers. In this research, we fabricated the polypropylene (PP) foam by using the TEMs and chemical blowing agents and compared to their physical properties. The density of the specimen was decreased when the contents of chemical blowing agents and TEMs were increased. In addition, the mechanical properties (i.e. tensile strength and impact strength) of specimens were deteriorated with increasing amount of chemical blowing agents and TEMs. However, PP foam produced with TEMs showed higher impact strength than the one with the chemical blowing agent. In order to clarify the dependence of impact strength of PP foam as the blowing agent, the morphology difference of the PP foams was investigated. Expanding properties of PP foams produced with TEMs was changed with TEMs content of PP foams. Processing conditions also influenced the mechanical properties of PP foam containing TEMs.

  2. Clinical analysis of occupational acute poisoning of HCFC-255%职业性急性二氯五氟丙烷中毒临床分析

    Institute of Scientific and Technical Information of China (English)

    郑倩玲; 陈嘉斌; 梁伟辉; 梁顺华; 余意玉

    2011-01-01

    目的:探讨职业性急性二氯五氟丙烷(HCFC-225 )中毒的临床特点及治疗方法.方法:回顾性分析2010年12月一起职业中毒事故中6例急性HCFC-225中毒患者的临床资料.结果:本组6例患者均有明确的急性泄露事故导致吸入HCFC-225的职业接触史,急性起病,均被诊断为职业性急性HCFC-225中毒.多数患者出现头晕、眼花、头痛、乏力、步态蹒跚、胸闷、恶心等,部分患者出现呕吐、咳嗽、咽痛、鼻塞、流涕等,严重者可出现意识障碍.体征方面,所有患者均出现急性病容和四肢肌力下降,5例出现呼吸音增粗,个别呼吸急促,严重者出现烦躁不安、嗜睡、昏睡、昏迷.中枢神经系统症状改变与HCFC-225接触时间呈剂量一效应关系.患者中毒第2日外周血白细胞计数均升高,1例患者胸部X线片示急性支气管炎改变,1例昏迷患者出现脑电图低电压改变,另1例出现动脉血氧分压偏低.糖皮质激素和脱水治疗有效.结论:职业性急性HCFC-225中毒的临床表现以中枢神经系统和呼吸系统的损害为主,及时的脱水治疗和早期、足量、短程糖皮质激素是治疗的关键.%Objective: To study the clinical features and treatments of occupational acute poisoning of HCFC-225. Methods: Clinical data of 6 patients with acute poisoning of HCFC-225 from an industrial accident in December 2010 were analyzed retrospectively. Results: The 6 patients were diagnosed of occupational acute poisoning of HCFC-225 according to acute onset and occupational exposure of HCFC-255 inhalation in an acute leakage accident Symptoms, such as dizziness, giddiness, headache, fatigue, waddling gait, nausea and chest distress were presented in most patients. Vomiting, cough, sore throat, stuffy and running nose were observed in some patients. Conscious disturbance was also revealed in severe cases. Clinical signs of acute facial features and limb muscle strength decline were observed in all

  3. Condensation of Downward-Flowing Zeotropic Mixture HCFC-123/HFC-134a on a Staggered Bundle of Horizontal Low-Finned Tubes

    Science.gov (United States)

    Honda, Hiroshi; Takamatsu, Hiroshi; Takata, Nobuo

    Expenmentswere conducted to obtain row-by-row heat transfer data during condensation of downward-flowing zeotropic refrigerant mixture HCFC-123/HFC-134 a on a staggered bundle of horizontal low-finned tubes. The vapor temperature and the HFC-134a m ass fraction at the tube bundle inlet were maintained at about 50°C and 14% respectively. The refrigerant mass velocity ranged from 9 to 33 kg/m2s, and the condensation temperature difference from 2 to 12K. Four kinds of low-finned tubes with different fin geometry were tested. The highest heat transfer coefficient was obtained with a tube which showed the highest performance for HCFC-123. However, the effect of fin geometry was much smaller for the mixture than for HCFC-123. The heat transfer coefficient and the vapor-phase mass transfer coefficient decreased significantly with decreasing mass velocity. On the other hand, the mass transfer coefficient increased with condensation temperature difference. This was due to the effect of suction associated with condensation. On the basis of the analogy between heat and mass transfer, a dimensionless correlation of the mass transfer coefficient was developed for each tube.

  4. Infrared Absorption Spectra, Radiative Efficiencies, and Global Warming Potentials of Newly-Detected Halogenated Compounds: CFC-113a, CFC-112 and HCFC-133a

    Directory of Open Access Journals (Sweden)

    Maryam Etminan

    2014-07-01

    Full Text Available CFC-113a (CF3CCl3, CFC-112 (CFCl2CFCl2 and HCFC-133a (CF3CH2Cl are three newly detected molecules in the atmosphere that are almost certainly emitted as a result of human activity. It is important to characterise the possible contribution of these gases to radiative forcing of climate change and also to provide information on the CO2-equivalence of their emissions. We report new laboratory measurements of absorption cross-sections of these three compounds at a resolution of 0.01 cm−1 for two temperatures 250 K and 295 K in the spectral range of 600–1730 cm−1. These spectra are then used to calculate the radiative efficiencies and global warming potentials (GWP. The radiative efficiencies are found to be between 0.15 and 0.3 W∙m−2∙ppbv−1. The GWP for a 100 year time horizon, relative to carbon dioxide, ranges from 340 for the relatively short-lived HCFC-133a to 3840 for the longer-lived CFC-112. At current (2012 concentrations, these gases make a trivial contribution to total radiative forcing; however, the concentrations of CFC-113a and HCFC-133a are continuing to increase. The 2012 CO2-equivalent emissions, using the GWP (100, are estimated to be about 4% of the current global CO2-equivalent emissions of HFC-134a.

  5. Preventing Blow up by Convective Terms in Dissipative PDE's

    Science.gov (United States)

    Bilgin, Bilgesu; Kalantarov, Varga; Zelik, Sergey

    2016-09-01

    We study the impact of the convective terms on the global solvability or finite time blow up of solutions of dissipative PDEs. We consider the model examples of 1D Burger's type equations, convective Cahn-Hilliard equation, generalized Kuramoto-Sivashinsky equation and KdV type equations. The following common scenario is established: adding sufficiently strong (in comparison with the destabilizing nonlinearity) convective terms to equation prevents the solutions from blowing up in a finite time and makes the considered system globally well-posed and dissipative and for weak enough convective terms the finite time blow up may occur similar to the case, when the equation does not involve convective term. This kind of result has been previously known for the case of Burger's type equations and has been strongly based on maximum principle. In contrast to this, our results are based on the weighted energy estimates which do not require the maximum principle for the considered problem.

  6. Medium-temperature supermarket refrigeration conversion from CFC-12 to HCFC-22 (R-12 to R-22)

    Energy Technology Data Exchange (ETDEWEB)

    Walker, D.H.

    1992-12-01

    The Electric Power Research Institute (EPRI) has undertaken a project to investigate the best approach for the conversion of medium-temperature supermarket refrigeration from R-12 (CFC) to R-22 (HCFC) so that the maximum energy-savings benefit can be realized by its member utilities and their customers. Such conversions will be necessary as CFCs are phased out. In this report, two medium temperature display case circuits at the EPRI/Safeway test store were converted. Single, large semihermetic, and open-drive compressors were tested. The large semihermetic and open-drive compressors were also equipped with cylinder unloaders and variable-speed drive so that either method of capacity control could be employed. The results of the testing showed that conversion to R-22 produced energy savings and that large semihermetic compressors with re-expansion unloaders were a viable alternative to single compressors in this application. Computer model results suggested that conversion of all medium-temperature refrigeration from R-12 to R-22 would result in peak demand savings of 5.3 kw (9.3%) and annual energy savings of 37,595 kWh (10.5%). Additional savings are possible by incorporating energy-efficient features such as floating head pressure control, condenser resizing to enable it to operate at a lower temperature, and high-efficiency condenser fan motors. Guidelines and procedures for energy-efficient retrofit are outlined.

  7. Lyman- photodissociation of CH3CFCl2 (HCFC-141b): Quantum yield and translational energy of hydrogen atoms

    Indian Academy of Sciences (India)

    Almuth Laeuter; Hans-Robert Volpp; Jai P Mittal; Rajesh K Vatsa

    2007-07-01

    The collision-free, room temperature gas-phase photodissociation dynamics of CH3CFCl2 (HCFC-141b) was studied using Lyman- laser radiation (121.6 nm) by the laser photolysis/laserinduced fluorescence `pump/probe’ technique. Lyman- radiation was used both to photodissociate the parent molecule and to detect the nascent H atom products via (22P → 12S) laser-induced fluorescence. Absolute H atom quantum yield, H = (0.39 ± 0.09) was determined by calibration method in which CH4 photolysis at 121.6 nm was used as a reference source of well-defined H atom concentrations. The line shapes of the measured H atom Doppler profiles indicate a Gaussian velocity distribution suggesting the presence of indirect H atom formation pathways in the Lyman- photodissociation of CH3CFCl2. The average kinetic energy of H atoms calculated from Doppler profiles was found to be T(lab) = (50 ± 3) kJ/mol. The nearly statistical translational energy together with the observed Maxwell-Boltzmann velocity distribution indicates that for CH3CFCl2 the H atom forming dissociation process comes closer to the statistical limit.

  8. Blow-up of generalized complex 4-manifolds

    CERN Document Server

    Cavalcanti, Gil R

    2009-01-01

    We introduce blow-up and blow-down operations for generalized complex 4-manifolds. Combining these with a surgery analogous to the logarithmic transform, we then construct generalized complex structures on nCP2 # m \\bar{CP2} for n odd, a family of 4-manifolds which admit neither complex nor symplectic structures unless n=1. We also extend the notion of a symplectic elliptic Lefschetz fibration, so that it expresses a generalized complex 4-manifold as a fibration over a two-dimensional manifold with boundary.

  9. Blow-up estimates for semilinear parabolic systems coupled in an equation and a boundary condition

    Institute of Scientific and Technical Information of China (English)

    王明新

    2001-01-01

    This paper deals with the blow-up rate estimates of solutions for semilinear parabolic systems coupled in an equation and a boundary condition. The upper and lower bounds of blow-up rates have been obtained.

  10. 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...

  11. Numerical study of blow-up in the Davey-Stewartson system

    KAUST Repository

    Klein, Christian

    2013-03-01

    Nonlinear dispersive partial differential equations such as the nonlinear Schrödinger equations can have solutions that blow up. We numerically study the long time behavior and potential blow-up of solutions to the focusing Davey-Stewartson II equation by analyzing perturbations of the lump and the Ozawa solutions. It is shown in this way that both are unstable to blow-up and dispersion, and that blow-up in the Ozawa solution is generic.

  12. On the Blow-up Phenomena of Cauchy Problem for the Camassa- Holm Equation

    Institute of Scientific and Technical Information of China (English)

    LIU Yongqin; WANG Weike

    2006-01-01

    We focus on the blow-up phenomena of Cauchy problem for the Camassa-Holm equation. Blow-up can occur only in the form of wave-breaking, i.e. the solution is bounded but its slope becomes unbounded in finite time. We proved that there is such a point that its slope becomes infinite exactly at breaking time. We also gave the precise blow-up rate and the blow-up set.

  13. Whistle Blowing: What Do Contemporary Ethical Theories Say?

    Directory of Open Access Journals (Sweden)

    Bosupeng Mpho

    2017-04-01

    Full Text Available The rising number of scandals leading to the closure of many large companies is worrisome. The traditional belief is that business and ethics are oxymorons and one is not expected to be totally virtuous during business operations. Nonetheless, this does not mean ethical standards should be side-lined. Professional associations such as the Chartered Financial Institute (CFA uphold moral values and urge members to exercise high moral standards and diligence in their duties. Philosophically, major accounting scandals could have been nipped in the bud by whistle blowing before the wrong deeds escalated. However whistle blowing is a major issue and is viewed as disloyalty. In this paper, the dilemmas of whistle blowing are evaluated using contemporary ethical theories which are: egoism, deontology and utilitarianism. The analysis shows that deontology and utilitarianism are based on altruism and may support whistle blowing because they are grounded on consideration of other people. It is worth noting that morally upright adults are often a result of being brought up as ethical children from a psychological standpoint.

  14. Dolphins Who Blow Bubbles: Anthropological Machines and Native Informants

    NARCIS (Netherlands)

    Lord, C.

    2011-01-01

    "Dolphins Who Blow Bubbles: Anthropological Machines and Native Informants" engages a reading between an Oscar winning and now ‘cult’ activist film The Cove (Louise Psihoyos 2009) and classical texts on the human-animal threshold. Giorgio Agamben’s The Open (2002) and Jacques Derrida’s "The Animal t

  15. Dolphins Who Blow Bubbles: Anthropological Machines and Native Informants

    NARCIS (Netherlands)

    Lord, C.

    2011-01-01

    "Dolphins Who Blow Bubbles: Anthropological Machines and Native Informants" engages a reading between an Oscar winning and now ‘cult’ activist film The Cove (Louise Psihoyos 2009) and classical texts on the human-animal threshold. Giorgio Agamben’s The Open (2002) and Jacques Derrida’s "The Animal

  16. Blow-up theories for semilinear parabolic equations

    CERN Document Server

    Hu, Bei

    2011-01-01

    There is an enormous amount of work in the literature about the blow-up behavior of evolution equations. It is our intention to introduce the theory by emphasizing the methods while seeking to avoid massive technical computations. To reach this goal, we use the simplest equation to illustrate the methods; these methods very often apply to more general equations.

  17. Preparation of zein fibers using solution blow spinning method

    Science.gov (United States)

    Zein fibers were successfully fabricated via solution blow spinning (SBS) using acetic acid as solvent. Surface tension, viscosity and modulus of zein solutions were respectively determined by force tensiometer and rheometer. Increases of these properties were observed with an increase of concentrat...

  18. PLA fibers with antimicrobial properties developed by solution blow spinning

    Science.gov (United States)

    The present work reports on the development and characterization of novel Poly(lactic acid) hybrid fibers with antimicrobial properties produced by solution blow spinning. This technique presents additional advantages over conventional electrospinning, such as reduced cost and higher rate of fiber p...

  19. Dolphins Who Blow Bubbles: Anthropological Machines and Native Informants

    NARCIS (Netherlands)

    Lord, C.

    2011-01-01

    "Dolphins Who Blow Bubbles: Anthropological Machines and Native Informants" engages a reading between an Oscar winning and now ‘cult’ activist film The Cove (Louise Psihoyos 2009) and classical texts on the human-animal threshold. Giorgio Agamben’s The Open (2002) and Jacques Derrida’s "The Animal t

  20. Blow-up of solution for a generalized Boussinesq equation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper studies the initial boundary value problem for a generalized Boussinesq equation and proves the existence and uniqueness of the local generalized solution of the problem by using the Galerkin method. Moreover, it gives the sufficient conditions of blow-up of the solution in finite time by using the concavity method.

  1. Employee perceptions regarding whistle-blowing in the workplace: A South African perspective

    Directory of Open Access Journals (Sweden)

    Sandra Perks

    2008-12-01

    Full Text Available The purpose of whistle-blowing is to eradicate unethical behaviour in the work place. This article investigates the perceptions of South African employees (n=387 employed in medium and large organisations regarding whistle-blowing. Respondents regard personal viewpoints and the supportive organisational environment as determining factors for whistle-blowing. South African employees have faced minimal negative consequences and will again engage in whistle-blowing, regardless of union support. Organisations can create a whistle-blowing culture by having a personal code of ethics, using hotlines, having an ethical committee, engaging in periodic ethics training and doing an annual ethical audit.

  2. Role of blowing snow in snow processes in Qilian Mountainous region

    Institute of Scientific and Technical Information of China (English)

    HongYi Li; Jian Wang; XiaoHua Hao

    2014-01-01

    Blowing snow is an important part of snow hydrologic processes in mountainous region, however the related researches were rare for the Qilian mountainous region where blowing snow is frequent. Using the observation dataset in 2008 snow season in Binggou wa-tershed in Qilian mountainous region, we systematically studied the energy and mass processes of blowing snow by field observation and model simulation. The results include the analysis of snow observation, the occurrence probability of blowing snow, blowing snow transport and blowing snow sublimation. It was found that blowing snow was obvious in high altitude region (4,146 m), the snow redistribution phenomena was remarkable. In Yakou station in the study region, blowing snow was easily occurred in midwinter and early spring when no snowmelt, the blowing snow transport was dominated in this period;when snowmelt beginning, the occur-rence probability of blowing snow decreased heavily because of the increasing air temperature, melt, and refrozen phenomena. The blowing snow sublimation accounted for 41.5%of total snow sublimation at Yakou station in 2008 snow season.

  3. The Strong Disjoint Blow-Up/Collapse Property

    Directory of Open Access Journals (Sweden)

    Héctor N. Salas

    2013-01-01

    Full Text Available Let be a topological vector space, and let be the algebra of continuous linear operators on . The operators are disjoint hypercyclic if there is such that the orbit is dense in . Bès and Peris have shown that if satisfy the Disjoint Blow-up/Collapse property, then they are disjoint hypercyclic. In a recent paper Bès, Martin, and Sanders, among other things, have characterized disjoint hypercyclic -tuples of weighted shifts in terms of this property. We introduce the Strong Disjoint Blow-up/Collapse property and prove that if satisfy this new property, then they have a dense linear manifold of disjoint hypercyclic vectors. This allows us to give a partial affirmative answer to one of their questions.

  4. Rotating Stall Suppression Using Oscillatory Blowing Actuation on Blades

    Science.gov (United States)

    2010-06-30

    AIAA Aerospace Sciences Meeting , Number 2009-1242, AIAA. Honors and Awards Received NONE AFRL Point of Contact Dr. Steven Puterbaugh and Dr. Todd...Rediniotis (2009, January). Internal plenum design and testing for an oscillatory blowing stall suppression system. In 47th AIAA Aerospace Sciences ...Meeting, Number 2009-1242. AIAA. Carter, C. J., S. A. Guillot, W. F. Ng, and W. W. Copenhaver (2001, July). Aerodynamic perfor- mace of a high-turning

  5. Lift augmentation via spanwise tip blowing - A numerical study

    Science.gov (United States)

    Childs, R. E.

    1986-01-01

    Numerical simulations of a low aspect ratio wing with and without a spanwise directed jet issuing from the wing tip have been performed. The results show that the tip vortex is displaced outward and upward by the blowing. This gives rise to a local lift augmentation mechanism, vortex lift caused by the vortex core being above the wing, and a global mechanism, the reduction of induced velocities due to greater apparent spin.

  6. Influence of Blowing of Argon on the Cleanness of Steel

    Directory of Open Access Journals (Sweden)

    A. Pribulová

    2012-09-01

    Full Text Available The mechanical properties of steel components are controlled by the chemical composition and mechanical treatment to which thesteel is submitted. Non-metallic inclusions have a very high influence on the steel quality but secondary metallurgy enables to reduce their content in the steel. Possibilities of secondary metallurgy are relatively extensive but financial situation in Slovak foundries does not enable to make investments in secondary metallurgy in the near future. Accessible means for influencing of steel quality is injection of an inert gas .Main goal of experiments described in the article was verify the influence of blowing of argon into the steel in an electric inductionfurnace on its cleanness. Duration and flow-rate of argon blowing have a very clearly influence on the final content of non-metallicinclusions. Minimum time of argon blowing necessary for reducing of content of non-metallic inclusions in one tonne electric inductionfurnace was more then 6 minutes and recommended argon flow rate was 10 litters per minute.

  7. Replacements For Ozone-Depleting Foaming Agents

    Science.gov (United States)

    Blevins, Elana; Sharpe, Jon B.

    1995-01-01

    Fluorinated ethers used in place of chlorofluorocarbons and hydrochlorofluorocarbons. Replacement necessary because CFC's and HCFC's found to contribute to depletion of ozone from upper atmosphere, and manufacture and use of them by law phased out in near future. Two fluorinated ethers do not have ozone-depletion potential and used in existing foam-producing equipment, designed to handle liquid blowing agents soluble in chemical ingredients that mixed to make foam. Any polyurethane-based foams and several cellular plastics blown with these fluorinated ethers used in processes as diverse as small batch pours, large sprays, or double-band lamination to make insulation for private homes, commercial buildings, shipping containers, and storage tanks. Fluorinated ethers proved useful as replacements for CFC refrigerants and solvents.

  8. Uniform Blow-Up Rates and Asymptotic Estimates of Solutions for Diffusion Systems with Nonlocal Sources

    Directory of Open Access Journals (Sweden)

    Zhoujin Cui

    2007-01-01

    Full Text Available This paper investigates the local existence of the nonnegative solution and the finite time blow-up of solutions and boundary layer profiles of diffusion equations with nonlocal reaction sources; we also study the global existence and that the rate of blow-up is uniform in all compact subsets of the domain, the blow-up rate of |u(t|∞ is precisely determined.

  9. A One-Dimensional Global-Scaling Erosive Burning Model Informed by Blowing Wall Turbulence

    Science.gov (United States)

    Kibbey, Timothy P.

    2014-01-01

    A derivation of turbulent flow parameters, combined with data from erosive burning test motors and blowing wall tests results in erosive burning model candidates useful in one-dimensional internal ballistics analysis capable of scaling across wide ranges of motor size. The real-time burn rate data comes from three test campaigns of subscale segmented solid rocket motors tested at two facilities. The flow theory admits the important effect of the blowing wall on the turbulent friction coefficient by using blowing wall data to determine the blowing wall friction coefficient. The erosive burning behavior of full-scale motors is now predicted more closely than with other recent models.

  10. Modeling of Droplet Generation in a Top Blowing Steelmaking Process

    Science.gov (United States)

    Rout, Bapin Kumar; Brooks, Geoff; Subagyo; Rhamdhani, M. Akbar; Li, Zushu

    2016-08-01

    Quantification of metal droplets ejected due to impinging gas jet on the surface of liquid metal is an important parameter for the understanding and for the modeling of the refining kinetics of reactions in slag-metal emulsion zone. In the present work, a numerical study has been carried out to critically examine the applicability of droplet generation rate correlation previously proposed by Subagyo et al. on the basis of dimensionless blowing number (N B). The blowing number was re-evaluated at the impingement point of jet with taking into account the temperature effect of change in density and velocity of the gas jet. The result obtained from the work shows that the modified blowing number N B,T at the furnace temperature of 1873 K (1600 °C) is approximately double in magnitude compared to N B calculated by Subagyo and co-workers. When N B,T has been employed to the Subagyo's empirical correlation for droplet generation, a wide mismatch is observed between the experimental data obtained from cold model and hot model experiments. The reason for this large deviation has been investigated in the current study, and a theoretical approach to estimate the droplet generation rate has been proposed. The suitability of the proposed model has been tested by numerically calculating the amount of metals in slag. The study shows that the weight of metals in emulsion falls in the range of 0 to 21 wt pct of hot metal weight when droplet generation rate has been calculated at ambient furnace temperature of 1873 K (1600 °C).

  11. Multiple—tube Permeable Element for Combined Blowing Converter

    Institute of Scientific and Technical Information of China (English)

    YANGWen-yuan; XUWei-hua; 等

    1994-01-01

    The method consisting of cold test and hot simulating has been proved to be reliable for designing permeable ele-ments.The carbon-magnesia multiple-tube permeable ele-ments which are formed by isostatical pressure have higher density,high heat resistance and good thermoshock resis-tance,The brickwork ,maintenance and erosion meha-nism of permeable elements were studied.The tehnology of combined blowing wa established based on the peculiari-ties of semi-steel refining at Panzhihua Irom& Steel Co.(PZISC).The service life of permeable elements reahed 600 heats,that means the permeable elements can work synchronitially with converter lining.

  12. Retrobulbar Hematoma in Blow-Out Fracture after Open Reduction

    Directory of Open Access Journals (Sweden)

    Ji Seon Cheon

    2013-07-01

    Full Text Available Retrobulbar hemorrhage, especially when associated with visual loss, is a rare but significant complication after facial bone reconstruction. In this article, two cases of retrobulbar hematoma after surgical repair of blow-out fracture are reported. In one patient, permanent loss of vision was involved, but with the other patient, we were able to prevent this by performing immediate decompression after definite diagnosis. We present our clinical experience with regard to the treatment process and method for prevention of retrobulbar hematoma using a scalp vein set tube and a negative pressure drainage system.

  13. 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

  14. 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

    2010-05-01

    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 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 22.8 (±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 using data

  15. Suppression of vortex shedding around a square cylinder using blowing

    Indian Academy of Sciences (India)

    Arun K Saha; Ankit Shrivastava

    2015-05-01

    Direct numerical simulation (DNS) of flow past a square cylinder at a Reynolds number of 100 has been carried out to explore the effect of blowing in the form of jet(s) on vortex shedding. Higher order spatial as well as temporal discretization has been employed for the discretization of governing equations. The varying number of jets, jet velocity profiles and different blowing velocities are studied to investigate the characteristics of vortex shedding. The parabolic velocity profile has been found to be more effective in suppressing the vortex shedding as compared to the uniform velocity. Complete suppression of vortex shedding along with remarkable reduction in drag coefficient has been achieved for both jet velocity profiles but at different velocities. The corresponding values for uniform and parabolic jet profiles are 0.87 and 0.6, respectively at a mass flux of 0.120. The study also reveals that there is considerable effect of the number of jets on the vortex shedding phenomena.

  16. Resistance blow-up effect in micro-circuit engineering

    Science.gov (United States)

    Tan, Michael L. P.; Saxena, Tanuj; Arora, Vijay K.

    2010-12-01

    The nonlinearity in the I- V characteristics of a scaled-down micro/nano-scale resistive channel is shown to elevate the DC and signal resistance as current approaches its saturation value. The deviation from traditional circuit engineering takes place when the applied voltage is increased beyond the critical voltage V c = ( V t/ ℓ) L, where V t is the thermal voltage, ℓ is the ohmic mean free path, and L is the length of the conducting channel. This resistance blow-up is more pronounced for a smaller-length resistor in a micro-circuit of two resistors with same ohmic value. The power consumed P = VI not only is lower but also is a linear function of voltage V as compared to the quadratic rise with V in the ohmic regime. The resistance blow-up effect also gives enhanced RC time constant for transients when a digital signal switches from low to high or vice versa. These results are of immense value to circuit designers and those doing device characterization to extract parasitic and transport parameters.

  17. Finite Element Modeling of Reheat Stretch Blow Molding of PET

    Science.gov (United States)

    Krishnan, Dwarak; Dupaix, Rebecca B.

    2004-06-01

    Poly (ethylene terephthalate) or PET is a polymer used as a packaging material for consumer products such as beverages, food or other liquids, and in other applications including drawn fibers and stretched films. Key features that make it widely used are its transparency, dimensional stability, gas impermeability, impact resistance, and high stiffness and strength in certain preferential directions. These commercially useful properties arise from the fact that PET crystallizes upon deformation above the glass transition temperature. Additionally, this strain-induced crystallization causes the deformation behavior of PET to be highly sensitive to processing conditions. It is thus crucial for engineers to be able to predict its performance at various process temperatures, strain rates and strain states so as to optimize the manufacturing process. In addressing these issues; a finite element analysis of the reheat blow molding process with PET has been carried out using ABAQUS. The simulation employed a constitutive model for PET developed by Dupaix and Boyce et al.. The model includes the combined effects of molecular orientation and strain-induced crystallization on strain hardening when the material is deformed above the glass transition temperature. The simulated bottles were also compared with actual blow molded bottles to evaluate the validity of the simulation.

  18. Effect of blow-holes on reliability of cast component

    Indian Academy of Sciences (India)

    B N Rao; Rajesh Ashokkumar

    2008-12-01

    This paper presents a study on the effect of blow-holes on the reliability of a cast component. The most probable point (MPP) based univariate response surface approximation is used for evaluating reliability. Crack geometry, blow-hole dimensions, external loads and material properties are treated as independent random variables. The methodology involves novel function decomposition at a most probable point that facilitates the MPP-based univariate response surface approximation of the original multivariate implicit limit state/performance function in the rotated Gaussian space. Once the approximate form of the original implicit limit state/performance function is defined, the failure probability can be obtained by Monte Carlo simulation (MCS), importance sampling technique, and first- and second-order reliability methods (FORM/SORM). FORTRAN code is developed to automate calls to ABAQUS for numerically simulating responses at sample points, to construct univariate response surface approximation, and to subsequently evaluate the failure probability by MCS, importance sampling technique, and FORM/SORM.

  19. Identification of an Unknown Assistant Blowing Agent in AC Blowing System%一种助发泡剂的鉴定

    Institute of Scientific and Technical Information of China (English)

    何文绚; Robert Shanks

    2004-01-01

    In this study, TLC was used to separate and purify the unknown assistant blowing agent in AC blowing system. After that, FTIR-Microscope was used to indicate the functional group in the uncommon unknown compound. Through combination of FTIR analysis, elemental analysis and other physical and chemical analysis, the molecular structure of unknown was deduced. Finally by explaining mass spectra of the unknown compounds, the molecular structure of unknown was further confirmed.

  20. Effect of direction of blowing air on morphology of nanofibers by bubbfil spinning

    Directory of Open Access Journals (Sweden)

    Zhang Shengzhong

    2016-01-01

    Full Text Available Blowing air in bubbfil spinning process can be used to not only overcome the surface tension of polymer bubbles, but also pull the debris to form either nanofibers or yarns. This paper studies experimentally the direction of blowing air on the morphology of obtained nanofibers.

  1. Fabrication of nanofiber non-wovens on the melt blowing die with air by-passes

    OpenAIRE

    Chen Ting; Yang Kang; Wu Li-Li

    2016-01-01

    The air flow field of the melt blowing die with air by-passes is simulated. The results show that fibers fabricated on the die with air by-passes are much finer than those without air by-passes, which indicates an energy-saving approach to fabricating nanofibers on the melt blowing equipment.

  2. SEMIDISCRETIZATION IN SPACE OF NONLINEAR DEGENERATE PARABOLIC EQUATIONS WITH BLOW-UP OF THE SOLUTIONS

    Institute of Scientific and Technical Information of China (English)

    Tetsuya Ishiwata; Masayoshi Tsutsumi

    2000-01-01

    Semidiscretization in space of nonlinear degenerate parabolic equations of nondivergent form is presented, under zero Dirichlet boundary condition. It is shown that semidiscrete solutions blow up in finite time. In particular, the asymptotic behavior of blowing-up solutions, is discussed precisely.

  3. Energy Decaying and Blow-Up of Solution for a Kirchhoff Equation with Strong Damping

    Institute of Scientific and Technical Information of China (English)

    YANG Zhifeng; QIU Dehua

    2009-01-01

    The initial boundary value problem for a Kirchhoff equation with Lipschitz type continuous coefficient is studied on bounded domain. Under some conditions, the energy decaying and blow-up of solution are discussed. By refining method, the exponent decay estimates of the energy function and the estimates of the life span of blow-up solutions are given.

  4. Remarks on the Blow-Up Solutions for the Critical Gross-Pitaevskii Equation

    Directory of Open Access Journals (Sweden)

    Xiaoguang Li

    2013-01-01

    Full Text Available This paper is concerned with the blow-up solutions of the critical Gross-Pitaevskii equation, which models the Bose-Einstein condensate. The existence and qualitative properties of the minimal blow-up solutions are obtained.

  5. Blow up of mild solutions of a system of partial differential equations with distinct fractional diffusions

    Directory of Open Access Journals (Sweden)

    Jose Villa-Morales

    2014-02-01

    Full Text Available We give a sufficient condition for blow up of positive mild solutions to an initial value problem for a nonautonomous weakly coupled system with distinct fractional diffusions. The proof is based on the study of blow up of a particular system of ordinary differential equations.

  6. Fabrication of nanofiber non-wovens on the melt blowing die with air by-passes

    Directory of Open Access Journals (Sweden)

    Chen Ting

    2016-01-01

    Full Text Available The air flow field of the melt blowing die with air by-passes is simulated. The results show that fibers fabricated on the die with air by-passes are much finer than those without air by-passes, which indicates an energy-saving approach to fabricating nanofibers on the melt blowing equipment.

  7. Computation and measurement of air temperature distribution of an industrial melt blowing die

    Directory of Open Access Journals (Sweden)

    Wu Li-Li

    2014-01-01

    Full Text Available The air flow field of the dual slot die on an HDF-6D melt blowing non-woven equipment is computed numerically. A temperature measurement system is built to measure air temperatures. The computation results tally with the measured results proving the correctness of the computation. The results have great valuable significance in the actual melt blowing production.

  8. GLOBAL SOLUTIONS AND FINITE TIME BLOW UP FOR DAMPED KLEIN-GORDON EQUATION

    Institute of Scientific and Technical Information of China (English)

    Runzhang XU; Yunhua DING

    2013-01-01

    We study the Cauchy problem of strongly damped Klein-Gordon equation.Global existence and asymptotic behavior of solutions with initial data in the potential well are derived.Moreover,not only does finite time blow up with initial data in the unstable set is proved,but also blow up results with arbitrary positive initial energy are obtained.

  9. Blow-up Mechanism of Classical Solutions to Quasilinear Hyperbolic Systems in the Critical Case

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper deals with the blow-up phenomenon, particularly, the geometric blow-up mechanism, of classical solutions to the Cauchy problem for quasilinear hyperbolic systems in the critical case. We prove that it is still the envelope of the same family of characteristics which yields the blowup of classical solutions to the Cauchy problem in the critical case.

  10. Modelling and Control of Blowing-Venting Operations in Manned Submarines

    CERN Document Server

    Font, Roberto; Murillo, Jose Alberto; Periago, Francisco

    2011-01-01

    Motivated by the study of the potential use of blowing and venting operations of ballast tanks in manned submarines as an alternative control system for manoeuvring, we first propose a mathematical model for these operations. This model extends previous works where only blowing is considered. Then, the model is applied to the control of an emergency manoeuvre by using only blowing and venting. To this end, we formulate a suitable constrained, nonlinear, optimal control problem where controls are linked to the variable aperture of blowing and venting valves of each of the tanks. The state law is composed of a system of nonlinear differential equations where the equations modelling blowing and venting processes are coupled with the Feldman, {\\it variable mass}, coefficient based hydrodynamic model for the equations of motion. In a second part, we carry out a rigorous mathematical analysis of the model: existence of a solution for both the state law and the optimal control problem is proved. Finally, we address ...

  11. VOLUMETRIC MASS TRANSFER COEFFICIENT BETWEEN SLAG AND METAL IN COMBINED BLOWING CONVERTER

    Institute of Scientific and Technical Information of China (English)

    Z.H. Wu; Z.S. Zou; W. Wu

    2005-01-01

    The effects of operation parameters of combined blowing converter on the volumetric mass transfer coefficient between slag and steel are studied with a cold model with water simulating steel, oil simulating slag and benzoic acid as the transferred substance between water and oil. The results show that, with lance level of 2.Im and the top blowing rate of 25000Nm3/h, the volumetric mass transfer coefficient changes most significantly when the bottom blowing rate ranges from 384 to 540Nm3/h. The volumetric mass transfer coefficient reaches its maximum when the lance level is 2. lm, the top blowing rates is 30000Nm3/h, and the bottom blowing rate is 384Nrr3/h with tuyeres located symmetrically at 0.66D of the converter bottom.

  12. Some blow-up problems for a semilinear parabolic equation with a potential

    Science.gov (United States)

    Cheng, Ting; Zheng, Gao-Feng

    The blow-up rate estimate for the solution to a semilinear parabolic equation u=Δu+V(x)|u in Ω×(0,T) with 0-Dirichlet boundary condition is obtained. As an application, it is shown that the asymptotic behavior of blow-up time and blow-up set of the problem with nonnegative initial data u(x,0)=Mφ(x) as M goes to infinity, which have been found in [C. Cortazar, M. Elgueta, J.D. Rossi, The blow-up problem for a semilinear parabolic equation with a potential, preprint, arXiv: math.AP/0607055, July 2006], is improved under some reasonable and weaker conditions compared with [C. Cortazar, M. Elgueta, J.D. Rossi, The blow-up problem for a semilinear parabolic equation with a potential, preprint, arXiv: math.AP/0607055, July 2006].

  13. 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)

  14. The short bunch blow-out regime in RF photoinjectors

    Energy Technology Data Exchange (ETDEWEB)

    Serafini, L. [INFN and Universita di Milano, Via Celoria 16, 20133Milano (Italy)

    1997-06-01

    A new beam dynamics regime of RF Photoinjectors is presented here, dealing with a violent bunch elongation under the action of longitudinal space charge forces. It is shown that such a blow-out expansion of the electron bunch can lead to highly linear behaviors of both the longitudinal and the transverse space charge field, a well known prerequisite to achieve minimum emittance dilution in photoinjectors. If operated in the ultra-short pancake-like bunch regime, such an effect can be very beneficial to the emittance correction mechanism, making it effective also for ultra-short pancake like bunches. The anticipated performances are presented: kA peak current beams can be generated directly out of the photoinjector (10 to 20 MeV exit energy) with rms normalized emittances below 1mm{center_dot}mrad. {copyright} {ital 1997 American Institute of Physics.}

  15. Potential application of aromatic plant extracts to prevent cheese blowing.

    Science.gov (United States)

    Librán, C M; Moro, A; Zalacain, A; Molina, A; Carmona, M; Berruga, M I

    2013-07-01

    This study aimed to inhibit the growth of Escherichia coli and Clostridium tyrobutyricum, common bacteria responsible for early and late cheese blowing defects respectively, by using novel aqueous extracts obtained by dynamic solid-liquid extraction and essential oils obtained by solvent free microwave extraction from 12 aromatic plants. In terms of antibacterial activity, a total of 13 extracts inhibited one of the two bacteria, and only two essential oils, Lavandula angustifolia Mill. and Lavandula hybrida, inhibited both. Four aqueous extracts were capable of inhibiting C. tyrobutyricum, but none were effective against E. coli. After extracts' chemical composition identification, relationship between the identified compounds and their antibacterial activity were performed by partial least square regression models revealing that compounds such as 1,8 cineole, linalool, linalyl acetate, β-phellandrene or verbene (present in essential oils), pinocarvone, pinocamphone or coumaric acid derivate (in aqueous extracts) were compounds highly correlated to the antibacterial activity.

  16. Super-Eddington Atmospheres that Don't Blow Away

    CERN Document Server

    Begelman, M C

    2000-01-01

    We show that magnetized, radiation dominated atmospheres can support steady state patterns of density inhomogeneity that enable them to radiate at far above the Eddington limit, without suffering mass loss. The inhomogeneities consist of periodic shock fronts bounding narrow, high-density regions, interspersed with much broader regions of low density. The radiation flux avoids the regions of high density, which are therefore weighed down by gravity, while gas in the low-density regions is slammed upward into the shock fronts by radiation force. As the wave pattern moves through the atmosphere, each parcel of matter alternately experiences upward and downward forces, which balance on average. Magnetic tension shares the competing forces between regions of different densities, preventing the atmosphere from blowing apart. We calculate the density structure and phase speed of the wave pattern, and relate these to the wavelength, the density contrast, and the factor by which the net radiation flux exceeds the Edd...

  17. Soot blower using fuel gas as blowing medium

    Science.gov (United States)

    Tanca, Michael C.

    1982-01-01

    A soot blower assembly (10) for use in combination with a coal gasifier (14). The soot blower assembly is adapted for use in the hot combustible product gas generated in the gasifier as the blowing medium. The soot blower lance (20) and the drive means (30) by which it is moved into and out of the gasifier is housed in a gas tight enclosure (40) which completely surrounds the combination. The interior of the enclosure (40) is pressurized by an inert gas to a pressure level higher than that present in the gasifier so that any combustible product gas leaking from the soot blower lance (20) is forced into the gasifier rather than accumulating within the enclosure.

  18. Ethmoid sinus osteoma associated with blow-out fracture.

    Science.gov (United States)

    Kim, Young-Jin; Kim, Dong-Yeon; Jun, Young-Joon; Seo, Byung-Chul

    2012-03-01

    Osteoma is a benign tumor that is composed of compact or cancellous bone. It is the most common benign neoplasm of the paranasal sinus, and ethmoid sinuses are the second most common sites of paranasal sinus osteoma. The symptoms of ethmoid sinus osteoma can give rise to various kinds and extent of symptoms. In symptomatic cases, surgical management is necessary, but appropriate surgical approach to the ethmoid sinus is not clearly established. We describe 2 male patients with a diagnosis of blow-out fractures after trauma; ethmoid sinus osteoma on preoperative computed tomography scans was coincidentally found, and the surgical correction was done simultaneously. The purpose of this article was to present the successful surgical removal of ethmoid osteoma through lamina papyracea and transcaruncular approach, resulting in both successful surgical correction and good cosmetic outcome.

  19. Global Dynamics, Blow-Up, and Bianchi Cosmology

    CERN Document Server

    Ben-Gal, Nitsan; Buchner, Johannes; Hell, Juliette; Karnauhova, Anna; Liebscher, Stefan; Rendall, Alan; Smith, Brian; Stuke, Hannes; Väth, Martin; Fiedler, Bernold

    2016-01-01

    Many central problems in geometry, topology, and mathematical physics lead to questions concerning the long-time dynamics of solutions to ordinary and partial differential equations. Examples range from the Einstein field equations of general relativity to quasilinear reaction-advection-diffusion equations of parabolic type. Specific questions concern the convergence to equilibria, the existence of periodic, homoclinic, and heteroclinic solutions, and the existence and geometric structure of global attractors. On the other hand, many solutions develop singularities in finite time. The singularities have to be analyzed in detail before attempting to extend solutions beyond their singularities, or to understand their geometry in conjunction with globally bounded solutions. In this context we have also aimed at global qualitative descriptions of blow-up and grow-up phenomena.

  20. Atmospheric chemistry of hydrofluorocarbons and hydrochlorofluorocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Sehested, J.

    1995-03-01

    Pulse radiolysis coupled with a time resolved UV absorption detection system and a FTIR spectrometer coupled to a 140 l reaction chamber was used to study the degradation of HCFCs and HFCs in the atmosphere. Reaction rates for a series of reactions of HFCs and HCFCs were investigated: F + RH, R + O{sub 2} + RO{sub 2} + NO, and RO{sub 2} + NO{sub 2} + M, together with UV absorption spectra of the halogenated alkyl (R) and halogenated alkyl peroxy radicals (RO{sub 2}). The products following the self reactions for RO{sub 2} radicals for RO{sub 2} = CF{sub 3}CF{sub 2}O{sub 2}, CF{sub 2}HCF{sub 2}O{sub 2}, CF{sub 3}CH{sub 2}O{sub 2}, CFH{sub 2}CFHO{sub 2}, CF{sub 3}O{sub 2}, and CF{sub 3}C(O)O{sub 2} were investigated by the FTIR setup. The results show that the self reaction of halogenated peroxy radicals give the alkoxy radical, RO, as product. The atmospheric fate of these radicals were C-C bond cleavage for CF{sub 3}CF{sub 2}O, CHF{sub 2}CF{sub 2}O, CFH{sub 2}CHFO, and CF{sub 3}C(O)O; while CF{sub 3}CH{sub 2}O radicals rect with O{sub 2} to give CF{sub 3}CHO and HO{sub 2}. the reaction between CFH{sub 2}O{sub 2} and HO{sub 2} was shown to give 29{+-}7 % CH{sub 2}FCOOH and 72{+-}11 % HCOF as the carbon containing products. (Abstract Truncated)

  1. Blow up and quenching for a problem with nonlinear boundary conditions

    Directory of Open Access Journals (Sweden)

    Nuri Ozalp

    2015-07-01

    Full Text Available In this article, we study the blow up behavior of the heat equation $ u_t=u_{xx}$ with $u_x(0,t=u^{p}(0,t$, $u_x(a,t=u^q(a,t$. We also study the quenching behavior of the nonlinear parabolic equation $v_t=v_{xx}+2v_x^{2}/(1-v$ with $v_x(0,t=(1-v(0,t^{-p+2}$, $ v_x(a,t=(1-v(a,t^{-q+2}$. In the blow up problem, if $u_0$ is a lower solution then we get the blow up occurs in a finite time at the boundary $x=a$ and using positive steady state we give criteria for blow up and non-blow up. In the quenching problem, we show that the only quenching point is $x=a$ and $v_t$ blows up at the quenching time, under certain conditions and using positive steady state we give criteria for quenching and non-quenching. These analysis is based on the equivalence between the blow up and the quenching for these two equations.

  2. Influence of particles shape on the vertical profile of blowing snow concentration

    Science.gov (United States)

    Vionnet, Vincent; Trouvilliez, Alexandre; Naaim-Bouvet, Florence; Guyomarc'h, Gilbert

    2013-04-01

    In alpine regions, blowing snow events strongly influence the temporal and spatial evolution of the snow cover throughout the winter season. In Antarctica, blowing snow is an essential surface mass balance process and plays a non-negligible role in the annual accumulation. The vertical profile of blowing snow concentration determines the quantity of snow transported in turbulent suspension. A power law is often used to represent this vertical profile. It serves as an analytical solution representing an equilibrium between vertical turbulent diffusion and gravitational settling. In this work, we study how the exponent of the power law depends on the type of transported particles. Vertical profiles of blowing snow concentration have been collected at the experimental site of Col du Lac Blanc (French Alps) in 2011 and 2012 and near the research station of Cap Prud'homme (Antarctica) in 2010 and 2011. We used mechanical gauges (butterfly nets) and optical devices (Snow Particles Counters). Profiles collected during blowing snow events with precipitation have been corrected to account for the contribution of snowfall. Results show that profiles collected during blowing snow without snowfall differ from the corrected profiles collected during snowfall. At a given wind speed, particles transported during snowfall have a lower settling velocity than particles transported without snowfall. This difference confirms earlier observations (Takahashi, 1985) and can be explained by the change of drag coefficient between dendritic and rounded particles. This difference pertains several hours after the end of the snowfall illustrating the fragmentation of snow grains during blowing snow events.

  3. Numerical study of the trailing vortex of a wing with wing-tip blowing

    Science.gov (United States)

    Lim, Hock-Bin

    1994-01-01

    Trailing vortices generated by lifting surfaces such as helicopter rotor blades, ship propellers, fixed wings, and canard control surfaces are known to be the source of noise, vibration, cavitation, degradation of performance, and other hazardous problems. Controlling these vortices is, therefore, of practical interest. The formation and behavior of the trailing vortices are studied in the present research. In addition, wing-tip blowing concepts employing axial blowing and spanwise blowing are studied to determine their effectiveness in controlling these vortices and their effects on the performance of the wing. The 3D, unsteady, thin-layer compressible Navier-Stokes equations are solved using a time-accurate, implicit, finite difference scheme that employs LU-ADI factorization. The wing-tip blowing is simulated using the actuator plane concept, thereby, not requiring resolution of the jet slot geometry. Furthermore, the solution blanking feature of the chimera scheme is used to simplify the parametric study procedure for the wing-tip blowing. Computed results are shown to compare favorably with experimental measurements. It is found that axial wing-tip blowing, although delaying the rolling-up of the trailing vortices and the near-field behavior of the flowfield, does not dissipate the circulation strength of the trailing vortex farther downstream. Spanwise wing-tip blowing has the effect of displacing the trailing vortices outboard and upward. The increased 'wing-span' due to the spanwise wing-tip blowing has the effect of lift augmentation on the wing and the strengthening of the trailing vortices. Secondary trailing vortices are created at high spanwise wing-tip blowing intensities.

  4. UNIFORM BLOW-UP PROFILES FOR HEAT EQUATIONS WITH COUPLING NONLOCAL SOURCES OF ASYMMETRIC MIXED TYPE NONLINEARITIES

    Institute of Scientific and Technical Information of China (English)

    Kong Linghua; Wang Jinhuan; Zheng Sining

    2012-01-01

    This article deals with a nonlocal heat system subject to null Dirichlet boundary conditions,where the coupling nonlocal sources consist of mixed type asymmetric nonlinearities.We at first give the criterion for simultaneous blow-up of solutions,and then establish the uniform blow-up profiles of solutions near the blow-up time.It is observed that not only the simultaneous blow-up rates of the two components u and v are asymmetric,but also the blow-up rates of the same component u (or v) may be in different levels under different dominations.

  5. Uniform blow-up profiles and boundary layer for a parabolic system with localized nonlinear reaction terms

    Institute of Scientific and Technical Information of China (English)

    LI Huiling; WANG Mingxin

    2005-01-01

    This paper deals with the blow-up properties of the solution to a semilinear parabolic system with localized nonlinear reaction terms, subject to the null Dirichlet boundary condition. We first give sufficient conditions for that the classical solution blows up in the finite time, secondly give necessary conditions and a sufficient condition for that two components blow up simultaneously, and then obtain the uniform blow-up profiles in the interior. Finally we describe the asymptotic behavior of the blow-up solution in the boundary layer.

  6. Stable Self-Similar Blow-Up Dynamics for Slightly {L^2}-Supercritical Generalized KDV Equations

    Science.gov (United States)

    Lan, Yang

    2016-07-01

    In this paper we consider the slightly {L^2}-supercritical gKdV equations {partial_t u+(u_{xx}+u|u|^{p-1})_x=0}, with the nonlinearity {5 < p < 5+\\varepsilon} and {0 < \\varepsilon≪ 1}. We will prove the existence and stability of a blow-up dynamics with self-similar blow-up rate in the energy space {H^1} and give a specific description of the formation of the singularity near the blow-up time.

  7. Self-sustained Oscillation Pulsed Air Blowing System for Energy Saving

    Institute of Scientific and Technical Information of China (English)

    CAI Maolin; XU Weiqing

    2010-01-01

    Currently, many studies have been made for years on dimensions of pneumatic nozzle, which influence the flow characteristic of blowing system. For the purpose of outputting the same blowing force, the supply pressure could be reduced by decreasing the ratio of length to diameter of nozzle. The friction between high speed air and pipe wall would be reduced if the nozzle is designed to be converging shape comparing with straight shape. But the volume flow and pressure, discussed in these studies, do not describe energy loss of the blowing system directly. Pneumatic power is an innovative principle to estimate pneumatic system's energy consumption directly. Based on the above principle, a pulse blowing method is put forward for saving energy. A flow experiment is carried out, in which the high speed air flows from the pulse blowing system and continuous blowing system respectively to a plate with grease on top. Supply pressure and the volume of air used for removing the grease are measured to calculate energy consumption. From the experiment result, the pulse blowing system performs to conserve energy comparing with the continuous blowing system. The frequency and duty ratio of pulse flow influence the blowing characteristic. The pulse blowing system performs to be the most efficient at the specified frequency and duty ratio. Then a pneumatic self-oscillated method based on air operated valve is put forward to generate pulse flow. A simulation is made about dynamic modeling the air operated valve and calculating the motion of the valve core and output pressure. The simulation result verifies the system to be able to generate pulse flow, and predicts the key parameters of the frequency and duty ratio measured by experiment well. Finally, on the basis of simplifying and solution of the pulse blowing system's mathematic model, the relationship between system's frequency duty ratio and the dimensions of components is simply described with four algebraic equations. The

  8. Oxygen and carbon discovered in exoplanet atmosphere `blow-off'

    Science.gov (United States)

    2004-02-01

    Oxygen and carbon discovered in exoplanet atmosphere ‘blow-off’ hi-res Size hi-res: 1096 kb Credits: ESA/Alfred Vidal-Madjar (Institut d’Astrophysique de Paris, CNRS, France) Oxygen and carbon discovered in exoplanet atmosphere ‘blow-off’ This artist’s impression shows an extended ellipsoidal envelope - the shape of a rugby-ball - of oxygen and carbon discovered around the well-known extrasolar planet HD 209458b. An international team of astronomers led by Alfred Vidal-Madjar (Institut d’Astrophysique de Paris, CNRS, France) observed the first signs of oxygen and carbon in the atmosphere of a planet beyond our Solar System for the first time using the NASA/ESA Hubble Space Telescope. The atoms of carbon and oxygen are swept up from the lower atmosphere with the flow of escaping atmospheric atomic hydrogen - like dust in a supersonic whirlwind - in a process called atmospheric ‘blow off’. Oxygen and carbon have been detected in the atmosphere of a planet beyond our Solar System for the first time. Scientists using the NASA/ESA Hubble Space Telescope have observed the famous extrasolar planet HD 209458b passing in front of its parent star, and found oxygen and carbon surrounding the planet in an extended ellipsoidal envelope - the shape of a rugby-ball. These atoms are swept up from the lower atmosphere with the flow of the escaping atmospheric atomic hydrogen, like dust in a supersonic whirlwind. The team led by Alfred Vidal-Madjar (Institut d’Astrophysique de Paris, CNRS, France) reports this discovery in a forthcoming issue of Astrophysical Journal Letters. The planet, called HD 209458b, may sound familiar. It is already an extrasolar planet with an astounding list of firsts: the first extrasolar planet discovered transiting its sun, the first with an atmosphere, the first observed to have an evaporating hydrogen atmosphere (in 2003 by the same team of scientists) and now the first to have an atmosphere containing oxygen and carbon. Furthermore

  9. Similarity transformation for equilibrium flows, including effects of blowing and suction

    CERN Document Server

    Chen, Xi

    2016-01-01

    A similarity transformation for the mean velocity profiles is obtained in sink flow turbulent boundary layers (TBL), including effects of blowing and suction. It is based on symmetry analysis which transforms the governing partial differential equations (for mean mass and momentum) into an ordinary differential equation and yields a new result including an exact, linear relation between the mean normal ($V$) and streamwise ($U$) velocities. A characteristic length is further introduced which, under a first order expansion in wall blowing/suction velocity, leads to the similarity transformation for $U$. This transformation is shown to be a group invariant under a generalized symmetry analysis and maps different $U$ profiles under different blowing/suction conditions into a (universal) profile under no blowing/suction. Its inverse transformation enables predictions of all mean quantities in the mean mass and momentum equations - $U$, $V$ and the Reynolds shear stress - in good agreement with direct numerical si...

  10. BLOW-UP CRITERION OF SMOOTH SOLUTIONS TO THE MHD EQUATIONS IN BESOV SPACES

    Institute of Scientific and Technical Information of China (English)

    YUAN Baoquan

    2005-01-01

    In this paper we discuss the logarithmic Sobolev inequalities in Besov spaces,and show their applications to the blow-up criterion of smooth solutions to the incompressible magneto-hydrodynamics equations.

  11. Origins of transverse emittance blow-up during the LHC energy tramp

    CERN Document Server

    Kuhn, M; Arduini, G; Kain, V; Schaumann, M; Tomas, R

    2014-01-01

    During LHC Run 1 about 30 % of the potential peak performance was lost due to transverse emittance blow-up through the LHC cycle. Measurements indicated that the majority of the blow-up occurred during the energy ramp. Until the end of LHC Run 1 this emittance blow-up could not be eliminated. In this paper the measurements and observations of emittance growth through the ramp are summarized. Simulation results for growth due to Intra Beam Scattering will be shown and compared to measurements. A summary of investigations of other possible sources will be given and backed up with simulations where possible. Requirements for commissioning the LHC with beam in 2015 after Long Shutdown 1 to understand and control emittance blow-up will be listed.

  12. Blow-up of solutions to parabolic inequalities in the Heisenberg group

    Directory of Open Access Journals (Sweden)

    Ibtehal Azman

    2015-06-01

    Full Text Available We establish a Fujita-type theorem for the blow-up of nonnegative solutions to a certain class of parabolic inequalities in the Heisenberg group. Our proof is based on a duality argument.

  13. Employees’ intention to blow the whistle: The role of fairness and moral identity

    Directory of Open Access Journals (Sweden)

    Karin Proost, Adríana Pavlinská, Elfi Baillien, Lieven Brebels, Anja Van den Broeck

    2013-10-01

    Full Text Available In this study we focused on key concepts – moral identity and fairness – in order to explain whistleblowingintention. We examined the relationship between intention to blow the whistle and moral identity, and exploredthe moderating effect of perceived supervisor procedural fairness in this relationship. Our results showed thatemployees (N = 278 with a strong moral identity were more likely to blow the whistle on wrongdoing of whichthey had become aware of, and employees who were low in moral identity were less likely to blow the whistle.Furthermore, we found that the impact of moral identity on the intention to blow the whistle is increased by highprocedural fairness, and that low procedural fairness leaves this relationship insignificant. These findingsrepresent new insights into the study of whistleblowing.

  14. Blow-up in p-Laplacian heat equations with nonlinear boundary conditions

    Science.gov (United States)

    Ding, Juntang; Shen, Xuhui

    2016-10-01

    In this paper, we investigate the blow-up of solutions to the following p-Laplacian heat equations with nonlinear boundary conditions: {l@{quad}l}(h(u))_t =nabla\\cdot(|nabla u|pnabla u)+k(t)f(u) &{in } Ω×(0,t^{*}), |nabla u|ppartial u/partial n=g(u) &on partialΩ×(0,t^{*}), u(x,0)=u0(x) ≥ 0 & {in } overline{Ω},. where {p ≥ 0} and {Ω} is a bounded convex domain in {RN}, {N ≥ 2} with smooth boundary {partialΩ}. By constructing suitable auxiliary functions and using a first-order differential inequality technique, we establish the conditions on the nonlinearities and data to ensure that the solution u( x, t) blows up at some finite time. Moreover, the upper and lower bounds for the blow-up time, when blow-up does occur, are obtained.

  15. Towards improving efficiency of control for blowing into a boundary layer through a permeable wall

    Science.gov (United States)

    Fomin, V. M.; Kornilov, V. I.; Boiko, A. V.

    2016-08-01

    The results of experimental and numerical investigations of the efficiency of control by an incompressible turbulent boundary layer with the help air blowing through a permeable wall fabricated with maintenance of most of the necessary requirements for the quality and configuration of microapertures and having a low effective roughness are analyzed. Various cases of modeling the process of air blowing into the boundary layer through a specified hi-tech finely perforated surface are considered, and the data for average parameters and characteristics of turbulence of the flow types under investigation are presented. A substantial decrease in the skin-friction coefficient along the model length, which can achieve 90% with increasing the blowing coefficient, is shown. The estimate of the energy consumption for the process of blowing under terrestrial conditions testifies to the high potential of this method of control capable to provide 4-5% gain in the total aerodynamic drag of a simple modeling configuration.

  16. THE EFFECT OF BLOWING AGENTS ON THE EFFECTIVENESS OF POLY(VINYL CHLORIDE) EXTRUSION

    National Research Council Canada - National Science Library

    Garbacz, Tomasz; Jachowicz, Tomasz; Tor-Świątek, Aneta

    2016-01-01

    .... The paper deals with cellular extrusion of PVC. The investigation of the process was conducted using state-of-the-art endothermic and exothermic blowing agents that were dosed in up to 1.5% by weight...

  17. Condensation of downward-flowing zeotropic mixture HCFC-123/HFC-134a on a staggered bundle of horizontal low-finned tubes

    Energy Technology Data Exchange (ETDEWEB)

    Honda, H.; Takamatsu, H.; Takata, N. [Kyushu Univ., Kasuga, Fukuoka (Japan). Inst. of Advanced Material Study

    1999-05-01

    Experiments were conducted to obtain row-by-row heat transfer data during condensation of downward-flowing zeotropic refrigerant mixture HCFC-123/HFC-134a on a 3 x 15 (columns x rows) staggered bundle of horizontal low-finned tubes. The vapor temperature and the HFC-134a mass fraction at the tube bundle inlet were maintained at about 50 C and 9%, respectively. The refrigerant mass velocity ranged from 9 to 34 kg/m{sup 2} s, and the condensation temperature difference from 3 to 12 K. The measured distribution of the vapor mass fraction in the tube bundle agreed fairly well with that of the equilibrium vapor mass fraction. The vapor phase mass transfer coefficient was obtained from the heat transfer data by subtracting the thermal resistance of the condensate film. The heat transfer coefficient and the mass transfer coefficient decreased significantly with decreasing mass velocity. These values first increased with the row number up to the third (or second) row, then decreased monotonically with further increasing row number, and then increased again at the last row. The mass transfer coefficient increased with condensation temperature difference, which was due to the effect of suction associated with condensation. On the basis of the analogy between heat and mass transfer, a dimensionless correlation of the mass transfer coefficient for the 4th to 14th rows was developed.

  18. On the blow-up of four dimensional Ricci flow singularities

    CERN Document Server

    Máximo, Davi

    2012-01-01

    In this paper we prove a conjecture by Feldman-Ilmanen-Knopf in \\cite{FIK} that the gradient shrinking soliton metric they constructed on the tautological line bundle over $\\CP^1$ is the uniform limit of blow-ups of a type I Ricci flow singularity on a closed manifold. We use this result to show that limits of blow-ups of Ricci flow singularities on closed four dimensional manifolds do not necessarily have non-negative Ricci curvature.

  19. Extremal K\\"ahler metrics on blow-ups of parabolic ruled surfaces

    OpenAIRE

    Tipler, Carl

    2011-01-01

    New examples of extremal K\\"ahler metrics on blow-ups of parabolic ruled surfaces are constructed. The method is based on the gluing construction of Arezzo, Pacard and Singer. This enables to endow ruled surfaces of the form $\\mathbb{P}(\\mathcal{O}\\oplus L)$ with special parabolic structures such that the associated iterated blow-up admits an extremal metric of non-constant scalar curvature.

  20. The Physical Modification of a Natural Rubber-Polypropylene Thermoplastic Elastomer Blend by Azobisformamide Blowing Agent

    OpenAIRE

    Safia Merabet; Farid Riahi; Abdelmalek Douibi

    2012-01-01

    The decomposition of azobisformamide (ABFA) blowing agent and its expansion in a soft grade of thermoplastic natural rubber composed of a 70/30 natural rubber (NR)/polypropylene (PP) was monitored using a Haake plasticorder. The aim of the study was to evaluate the effect of different concentrations of the blowing agent and to investigate its eventual interactions with a sulfur-based curing system that was used for the dynamic vulcanization. The plastograms allowed to detect variations in the...

  1. Fukushima plutonium effect and blow-up regimes in neutron-multiplying media

    CERN Document Server

    Rusov, V D; Vaschenko, V M; Linnik, E P; Zelentsova, T N; Beglaryan, M E; Chernegenko, S A; Kosenko, S I; Molchinikolov, P A; Smolyar, V P; Grechan, E V

    2012-01-01

    It is shown that the capture and fission cross-sections of 238U and 239Pu increase with temperature within 1000-3000K range, in contrast to those of 235U, that under certain conditions may lead to the so-called blow-up modes, stimulating the anomalous neutron flux and nuclear fuel temperature growth. Some features of the blow-up regimes in neutron-multiplying media are discussed.

  2. Periodic blow-up solutions and their limit forms for the generalized Camassa-Holm equation

    Institute of Scientific and Technical Information of China (English)

    Zhengrong Liu; Boling Guo

    2008-01-01

    In this paper, we consider the generalized Camassa-Holm equation ut + 2kux -uxxt + au2ux = 2uxuxx-uuxxxUnder substitution ζ = x - ct, some new explicit periodic wave solutions and their limit forms are presented through some special phase orbits. These periodic wave solutions tend to infinity on ζ - u plane periodically. Thus we call them periodic blow-up solutions. To our knowledge, such periodic blow-up solutions have not been found in any other equations.

  3. Free-stretch-blow Investigation of Poly(ethylene terephthalate) over a Large Process Window

    OpenAIRE

    Nixon, James; Menary, Gary; Yan, Shiyong

    2016-01-01

    This paper highlights for the first time a full comprehension of the deformation procedure during the injection stretch blow moulding (ISBM) process of poly(ethylene terephthalate) (PET) containers, namely thin-walled rigid bottles. The processes required to form PET bottles are complicated and extensive; any development in understanding the nature of material deformation can potentially improve the bottle optimisation process. Removing the bottle mould and performing free-stretch-blow (FSB) ...

  4. Description of regional blow-up in a porous-medium equation

    Directory of Open Access Journals (Sweden)

    Carmen Cortazar

    2002-10-01

    Full Text Available We describe the (finite-time blow-up phenomenon for a non-negative solution of a porous medium equation of the form $$ u_t = Delta u^m + u^m $$ in the entire space. Here $m>1$ and the initial condition is assumed compactly supported. Blow-up takes place exactly inside a finite number of balls with same radii and exhibiting the same self-similar profile.

  5. How does nose blowing effect the computed tomography of paranasal sinuses in chronic sinusitis?

    Energy Technology Data Exchange (ETDEWEB)

    Savranlar, Ahmet; Uzun, Lokman; Ugur, Mehmet Birol; Mahmutyazicioglu, Kamran; Ozer, Tulay; Gundogdu, Sadi

    2005-02-01

    Objective: Our aim was to determine whether inward or outward movement of the secretions in the paranasal sinuses due to nose blowing after nasal decongestion has any effect on the paranasal sinus computed tomography (CT) images in patients with sinusitis and to asses whether nose blowing may result in misdiagnosis or overdiagnosis in radiological evaluation of sinusitis. Materials and methods: Twenty-four patients with chronic sinusitis were evaluated in an academic tertiary care hospital and data were collected prospectively. After coronal sinus computed tomography scans were performed at 100 mA setting which was half the value of the standard radiation dose suggested by the manufacturer, topical decongestion was applied to each nostril followed by nose blowing 10 min later. Sinus CT scans were then repeated at the same setting. We evaluated the mucosal thickness of medial, lateral, superior and inferior maxillary and frontal sinus walls and the maximal thickness in anterior ethmoidal cells. The measurements prior to and following nose blowing were compared with Wilcoxon signed ranks test. The obtained images were also staged using Lund-McKay staging system separately and the scores were compared with Student's t-test. Results: We observed a tendency towards reduction in mucosal thickness after nose blowing. There were statistically significant differences between maxillary sinus inferior wall and frontal sinus inferior wall mucosal thickness values prior to and after nose blowing. The difference however was very small, about 0.5 mm in magnitude and Lund-McKay score did not change in any of the patients after nose blowing. Conclusion: Nose blowing and topical nasal decongestion does not have any effect on the diagnostic accuracy of sinus CT in chronic sinusitis patients.

  6. Generating Soap Bubbles by Blowing on Soap Films.

    Science.gov (United States)

    Salkin, Louis; Schmit, Alexandre; Panizza, Pascal; Courbin, Laurent

    2016-02-19

    Making soap bubbles by blowing air on a soap film is an enjoyable activity, yet a poorly understood phenomenon. Working either with circular bubble wands or long-lived vertical soap films having an adjustable steady state thickness, we investigate the formation of such bubbles when a gas is blown through a nozzle onto a film. We vary film size, nozzle radius, space between the film and nozzle, and gas density, and we measure the gas velocity threshold above which bubbles are formed. The response is sensitive to containment, i.e., the ratio between film and jet sizes, and dissipation in the turbulent gas jet, which is a function of the distance from the film to the nozzle. We rationalize the observed four different regimes by comparing the dynamic pressure exerted by the jet on the film and the Laplace pressure needed to create the curved surface of a bubble. This simple model allows us to account for the interplay between hydrodynamic, physicochemical, and geometrical factors.

  7. Solution Blow Spinning of Food-Grade Gelatin Nanofibers.

    Science.gov (United States)

    Liu, Fei; Avena-Bustillos, Roberto J; Bilbao-Sainz, Cristina; Woods, Rachelle; Chiou, Bor-Sen; Wood, Delilah; Williams, Tina; Yokoyama, Wallace; Glenn, Gregory M; McHugh, Tara H; Zhong, Fang

    2017-06-01

    The primary advantage of nanofibers over larger diameter fibers is the larger surface area to volume ratio. This study evaluated solution blow spinning (SBS) processing conditions for obtaining food-grade gelatin nanofibers from mammalian and fishery byproducts, such as pork skin gelatins (PGs) and high molecular weight fish skin gelatin (HMWFG). HMWFG had a highest intact collagen structure compared to PGs. PGs with different Bloom values, solution viscosities, and surface tensions were compared with HMWFG for their ability to produce nanofibers through SBS. Only HMWFG fibers were obtained irrespective of processing conditions, which looked like fluffy cotton candy. HMWFG nanofibers had round morphologies with a narrower diameter distribution and lower average fiber diameter (AFD) under medium gelatin concentrations, medium air pressures, and medium feed rates. The highest glass transition temperature (Tg ) values were obtained at medium concentrations, medium air pressure, and either high or low feed rate. The thinnest HMWFG nanofibers with an AFD of 80.1 nm and the highest Tg value of 59.0 °C could be formed by combining a concentration of 17.6% (w/v), an air pressure of 0.379 MPa, and a feed rate of 0.06 mL/min from the response surface analysis. HMWFG Brunauer, Emmett, and Teller surface area increased from 221 to 237 m(2) /g, indicating their potential applicability for active compound carrier. © 2017 Institute of Food Technologists®.

  8. Action of Ants on Vertebrate Carcasses and Blow Flies (Calliphoridae).

    Science.gov (United States)

    Paula, Michele C; Morishita, Gustavo M; Cavarson, Carolina H; Gonçalves, Cristiano R; Tavares, Paulo R A; Mendonça, Angélica; Súarez, Yzel R; Antonialli-Junior, William F

    2016-11-01

    Forensic entomology is a science that uses insect fauna as a tool to assist in criminal investigations and civil proceedings. Although the most researched insects are the Diptera and Coleoptera, ants may be present in all stages of decomposition. The aim of this study was to evaluate the role of ants and their action on blow flies during the decomposition process. Experiments were performed in which four pig carcasses were exposed in the cold and dry season (November/2012 and March/2013) and four in the hot and wet season (May/2013 and August/2013). Flies were the first insects to detect and interact with the carcasses, and six species of the Calliphoridae family were identified. Ants (Hymenoptera: Formicidae) were the second group, with six subfamilies identified. Myrmycinae represented 42% of the species, followed by Formicinae (28%), Ectatominae and Ponerinae (both 10%), and Ecitoninae and Dolichoderinae (both 5%). The ants acted on the carcasses as predators of visiting species, omnivores, and necrophagous, in all cases significantly affecting the decomposition time, slowing it down when the ants preyed on adult and immature insects consuming the carcass, or accelerating it by consuming the carcass and creating holes that could serve as gateways for the action of other organisms. The ants also generated artifacts that could lead to forensic misinterpretation.

  9. Generating Soap Bubbles by Blowing on Soap Films

    Science.gov (United States)

    Salkin, Louis; Schmit, Alexandre; Panizza, Pascal; Courbin, Laurent

    2016-02-01

    Making soap bubbles by blowing air on a soap film is an enjoyable activity, yet a poorly understood phenomenon. Working either with circular bubble wands or long-lived vertical soap films having an adjustable steady state thickness, we investigate the formation of such bubbles when a gas is blown through a nozzle onto a film. We vary film size, nozzle radius, space between the film and nozzle, and gas density, and we measure the gas velocity threshold above which bubbles are formed. The response is sensitive to containment, i.e., the ratio between film and jet sizes, and dissipation in the turbulent gas jet, which is a function of the distance from the film to the nozzle. We rationalize the observed four different regimes by comparing the dynamic pressure exerted by the jet on the film and the Laplace pressure needed to create the curved surface of a bubble. This simple model allows us to account for the interplay between hydrodynamic, physicochemical, and geometrical factors.

  10. Exploring confidentiality in the context of nurse whistle blowing: issues for nurse managers.

    Science.gov (United States)

    Jackson, Debra; Peters, Kath; Hutchinson, Marie; Edenborough, Michel; Luck, Lauretta; Wilkes, Lesley

    2011-07-01

    The aim of this paper is to reveal the experiences and meaning of confidentiality for Australian nurses in the context of whistle blowing. Despite the ethical, legal and moral importance of confidentiality within the health-care context, little work has addressed the implications of confidentially related to whistle-blowing events. The study used qualitative narrative inquiry. Eighteen Australian nurses, with first-hand experience of whistle blowing, consented to face-to-face semi-structured interviews. Four emergent themes relating to confidentiality were identified: (1) confidentiality as enforced silence; (2) confidentiality as isolating and marginalizing; (3) confidentiality as creating a rumour mill; and (4) confidentiality in the context of the public's 'right to know'. The interpretation and application of confidentiality influences the outcomes of whistle blowing within the context of health-care services. Conversely, confidentially can be a protective mechanism for health-care institutions. It is beholden upon nurse manager to carefully risk manage whistle-blowing events. It is important that nurse managers are aware of the consequences of their interpretation and application of confidentiality to whistle-blowing events, and the potentially competing outcomes for individuals and the institution. © 2011 The Authors. Journal compilation © 2011 Blackwell Publishing Ltd.

  11. Occurrence of blow fly species (Diptera: calliphoridae) in Phitsanulok Province, Northern Thailand.

    Science.gov (United States)

    Bunchu, Nophawan; Sukontason, Kom; Sanit, Sangob; Chidburee, Polprecha; Kurahashi, Hiromu; Sukontason, Kabkaew L

    2012-12-01

    Based on the current forensic importance of blow flies (Diptera: Calliphoridae), their biological aspects have been studied increasingly worldwide. The blow fly fauna in Phitsanulok Province, Northern Thailand was studied from May 2009 to April 2010 in the residential, agricultural, mountainous and forested areas of Muang, Wat Bot, Nakhon Thai and Wang Thong districts, respectively, in order to know the occurrence of blow flies in this province. Collections were carried out monthly using commercial funnel fly traps and sweeping methods, with 1-day tainted pork viscera as bait. Identification of adult blow flies exhibited 14 634 specimens, comprising of 5 subfamilies, 14 genera and 36 species. Chrysomya megacephala (Fabricius, 1794) and Achoetandrus rufifacies (Macquart, 1843) were the most and second most abundant species trapped, respectively. These two species of carrion flies prevailed in all the types of land investigated. We calculated and compared the diversity indices, species evenness and richness, and similarity coefficients of the blow fly species in various areas. The data from this study may be used to identify the potential of forensicallyimportant fly species within Phitsanulok Province and fulfill the information on blow fly fauna in Thailand.

  12. First Satellite-detected Perturbations of Outgoing Longwave Radiation Associated with Blowing Snow Events over Antarctica

    Science.gov (United States)

    Yang, Yuekui; Palm, Stephen P.; Marshak, Alexander; Wu, Dong L.; Yu, Hongbin; Fu, Qiang

    2014-01-01

    We present the first satellite-detected perturbations of the outgoing longwave radiation (OLR) associated with blowing snow events over the Antarctic ice sheet using data from Cloud-Aerosol Lidar with Orthogonal Polarization and Clouds and the Earth's Radiant Energy System. Significant cloud-free OLR differences are observed between the clear and blowing snow sky, with the sign andmagnitude depending on season and time of the day. During nighttime, OLRs are usually larger when blowing snow is present; the average difference in OLRs between without and with blowing snow over the East Antarctic Ice Sheet is about 5.2 W/m2 for the winter months of 2009. During daytime, in contrast, the OLR perturbation is usually smaller or even has the opposite sign. The observed seasonal variations and day-night differences in the OLR perturbation are consistent with theoretical calculations of the influence of blowing snow on OLR. Detailed atmospheric profiles are needed to quantify the radiative effect of blowing snow from the satellite observations.

  13. Understanding the bacterial communities of hard cheese with blowing defect.

    Science.gov (United States)

    Bassi, Daniela; Puglisi, Edoardo; Cocconcelli, Pier Sandro

    2015-12-01

    The environment of hard cheese encourages bacterial synergies and competitions along the ripening process, which might lead in defects such as clostridial blowing. In this study, Denaturing Gradient Gel Electrophoresis (DGGE), a quantitative Clostridium tyrobutyricum PCR and next-generation Illumina-based sequencing of 16S rRNA gene were applied to study 83 Grana Padano spoiled samples. The aim was to investigate the community of clostridia involved in spoilage, the ecological relationships with the other members of the cheese microbiota, and the effect of lysozyme. Three main genera were dominant in the analysed cheeses, Lactobacillus, Streptococcus and Clostridium, and the assignment at the species level was of 94.3% of 4,477,326 high quality sequences. C. tyrobutyricum and C. butyricum were the most prevalent clostridia. Hierarchical clustering based on the abundance of bacterial genera, revealed three main clusters: one characterized by the highest proportion of Clostridium, a second where Lactobacillus was predominant and the last, dominated by Streptococcus thermophilus. Ecological relationships among species were found: cheeses characterized by an high abundance of S. thermophilus and L. rhamnosus were spoiled by C. tyrobutyricum while, when L. delbrueckii was the most abundant Lactobacillus, C. butyricum was the dominant spoiling species. Lysozyme also shaped the bacterial community, reducing C. tyrobutyricum in favour of C. butyricum. Moreover, this preservative increased the proportion of L. delbrueckii and obligate heterofermentative lactobacilli and lowered L. helveticus and non-starter species, such as L. rhamnosus and L. casei.

  14. Blow collection as a non-invasive method for measuring cortisol in the beluga (Delphinapterus leucas.

    Directory of Open Access Journals (Sweden)

    Laura A Thompson

    Full Text Available Non-invasive sampling techniques are increasingly being used to monitor glucocorticoids, such as cortisol, as indicators of stressor load and fitness in zoo and wildlife conservation, research and medicine. For cetaceans, exhaled breath condensate (blow provides a unique sampling matrix for such purposes. The purpose of this work was to develop an appropriate collection methodology and validate the use of a commercially available EIA for measuring cortisol in blow samples collected from belugas (Delphinapterus leucas. Nitex membrane stretched over a petri dish provided the optimal method for collecting blow. A commercially available cortisol EIA for measuring human cortisol (detection limit 35 pg ml-1 was adapted and validated for beluga cortisol using tests of parallelism, accuracy and recovery. Blow samples were collected from aquarium belugas during monthly health checks and during out of water examination, as well as from wild belugas. Two aquarium belugas showed increased blow cortisol between baseline samples and 30 minutes out of water (Baseline, 0.21 and 0.04 µg dl-1; 30 minutes, 0.95 and 0.14 µg dl-1. Six wild belugas also showed increases in blow cortisol between pre and post 1.5 hour examination (Pre 0.03, 0.23, 0.13, 0.19, 0.13, 0.04 µg dl-1, Post 0.60, 0.31, 0.36, 0.24, 0.14, 0.16 µg dl-1. Though this methodology needs further investigation, this study suggests that blow sampling is a good candidate for non-invasive monitoring of cortisol in belugas. It can be collected from both wild and aquarium animals efficiently for the purposes of health monitoring and research, and may ultimately be useful in obtaining data on wild populations, including endangered species, which are difficult to handle directly.

  15. The blow-off mechanism of a bluff-body stabilized laminar premixed flame

    KAUST Repository

    Kedia, Kushal S.

    2015-04-01

    © 2014 The Combustion Institute. The objective of this work is to investigate the dynamics leading to blow-off of a laminar premixed flame stabilized on a confined bluff-body using high fidelity numerical simulations. We used unsteady, fully resolved, two-dimensional simulations with detailed chemical kinetics and species transport for methane-air combustion. The flame-wall interaction between the hot reactants and the heat conducting bluff-body was accurately captured by incorporating the conjugate heat exchange between them. Simulations showed a shear-layer stabilized flame just downstream of the bluff-body, with a recirculation zone formed by the products of combustion. The flame was negatively stretched along its entire length, primarily dominated by the normal component of the strain. Blow-off was approached by decreasing the mixture equivalence ratio, at a fixed Reynolds number, of the incoming flow. A flame is stable (does not undergo blow-off) when (1) flame displacement speed is equal to the flow speed and (2) the gradient of the flame displacement speed normal to its surface is higher than the gradient of the flow speed along the same direction. As the equivalence ratio is reduced, the difference between the former and the latter shrinks until the dynamic stability condition (2) is violated, leading to blow-off. Blow-off initiates at a location where this is first violated along the flame. Our results showed that this location was far downstream from the flame anchoring zone, near the end of the recirculation zone. Blow-off started by flame pinching separating the flame into an upstream moving (carried within the recirculation zone) and a downstream convecting (detached from the recirculation zone) flame piece. Within the range of operating conditions investigated, the conjugate heat exchange with the bluff-body had no impact on the flame blow-off.

  16. Global existence and blow-up of solutions to a parabolic system with nonlocal sources and boundaries

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper deals with a semi-linear parabolic system with nonlinear nonlocal sources and nonlocal boundaries.By using super-and sub-solution techniques,we first give the sufficient conditions that the classical solution exists globally and blows up in a finite time respectively,and then give the necessary and sufficient conditions that two components u and v blow up simultaneously.Finally,the uniform blow-up profiles in the interior are presented.

  17. Global existence and blow-up of solutions to a parabolic system with nonlocal sources and boundaries

    Institute of Scientific and Technical Information of China (English)

    Ling-hua KONG; Ming-xin WANG

    2007-01-01

    This paper deals with a semi-linear parabolic system with nonlinear nonlocal sources and nonlocal boundaries. By using super- and sub-solution techniques, we first give the sufficient conditions that the classical solution exists globally and blows up in a finite time respectively, and then give the necessary and sufficient conditions that two components u and v blow up simultaneously. Finally, the uniform blow-up profiles in the interior are presented.

  18. The effect of blow flies (Diptera: Calliphoridae) on the size and weight of mangos (Mangifera indica L.)

    OpenAIRE

    Saeed, Shafqat; NAQQASH, Muhammad Nadir; Jaleel, Waqar; Saeed, Qamar; Ghouri, Fozia

    2016-01-01

    Background: Pollination has a great effect on the yield of fruit trees. Blow flies are considered as an effective pollinator compared to hand pollination in fruit orchards. Therefore, this study was designed to evaluate the effect of different pollination methods in mango orchards. Methodology: The impact of pollination on quantity and quality of mango yield by blow flies was estimated by using three treatments, i.e., open pollinated trees, trees were covered by a net in the presence of blow ...

  19. Retrieval of HCFC-142b (CH3CClF2) from ground-based high-resolution infrared solar spectra: Atmospheric increase since 1989 and comparison with surface and satellite measurements

    Science.gov (United States)

    Mahieu, Emmanuel; Lejeune, Bernard; Bovy, Benoît; Servais, Christian; Toon, Geoffrey C.; Bernath, Peter F.; Boone, Christopher D.; Walker, Kaley A.; Reimann, Stefan; Vollmer, Martin K.; O'Doherty, Simon

    2017-01-01

    We have developed an approach for retrieving HCFC-142b (CH3CClF2) from ground-based high-resolution infrared solar spectra, using its ν7 band Q branch in the 900-906 cm-1 interval. Interferences by HNO3, CO2 and H2O have to be accounted for. Application of this approach to observations recorded within the framework of long-term monitoring activities carried out at the northern mid-latitude, high-altitude Jungfraujoch station in Switzerland (46.5°N, 8.0°E, 3580 m above sea level) has provided a total column times series spanning the 1989 to mid-2015 time period. A fit to the HCFC-142b daily mean total column time series shows a statistically-significant long-term trend of (1.23±0.08×1013 molec cm-2) per year from 2000 to 2010, at the 2-σ confidence level. This corresponds to a significant atmospheric accumulation of (0.94±0.06) ppt (1 ppt=1/1012) per year for the mean tropospheric mixing ratio, at the 2-σ confidence level. Over the subsequent time period (2010-2014), we note a significant slowing down in the HCFC-142b buildup. Our ground-based FTIR (Fourier Transform Infrared) results are compared with relevant data sets derived from surface in situ measurements at the Mace Head and Jungfraujoch sites of the AGAGE (Advanced Global Atmospheric Gases Experiment) network and from occultation measurements by the ACE-FTS (Atmospheric Chemistry Experiment-Fourier Transform Spectrometer) instrument on-board the SCISAT satellite.

  20. A consideration on the electric field formed by blowing snow particles

    Science.gov (United States)

    Omiya, Satoshi; Sato, Atsushi

    2013-04-01

    Fluctuations of the atmospheric electric field strength have been reported during blowing snow events. A primary factor of this phenomenon is the electrification of the blowing snow particles. Electric force applied to the blowing snow particles may be a contributing factor in the formation of snow drifts and snow cornices and changing particles' trajectory motion. These can cause natural disaster such as an avalanche and visibility deterioration. Therefore, charging phenomenon of the blowing snow particles is an important issue in terms of not only precise understanding of the particle motion but disaster prevention. The purpose of this study was to clarify the fluctuation characteristics of the electric field. In previous studies, some numerical models have been proposed; however, these models did not consider the dependency of the particle charges on the particle diameter or the height dependency of the horizontal mass flux. Taking into account those dependencies, we estimated the vertical electric field distribution. In this study, an experimental equation (Omiya et al., 2011), which can estimate the individual particle charge from the particle diameter and the air temperature, was used. In addition, the approximation equations of the vertical distribution of wind speed, the horizontal mass flux, and the average particle diameter were also used. A hot-wire anemometer was used to measure the wind speed. A snow particle counter (SPC) was used to measure the horizontal mass flux and the particle diameter distribution. This experiment was conducted in a cold wind tunnel (Ice and Snow Research Center, NIED, JAPAN) at an air temperature of -10 degree Celsius. In this calculation, for simplicity, some assumptions were considered; 1) The particle diameter and the particle number density are horizontally constant and uniform. (The electric field formed by the blowing snow particles is uniform horizontally.) 2) All the blowing snow particles are electrified negatively

  1. Computational Film Cooling Effectiveness of Dual Trench Configuration on Flat Plate at Moderate Blowing Ratios

    Institute of Scientific and Technical Information of China (English)

    Antar M.M.Abdala; Qun Zheng; Fifi N.M.Elwekeel; Ping Dong

    2013-01-01

    In the present work,computational simulations was made using ANSYS CFX to predict the improvements in film cooling performance with dual trench.Dual-trench configuration consists of two trenches together,one wider trench and the other is narrow trench that extruded from the wider one.Several blowing ratios in the range (0.5∶5) were investigated.The pitch-to-diameter ratio of 2.775 is used.By using the dual trench configuration,the coolant jet impacted the trench wall two times allowing increasing the spreading of coolant laterally in the trench,reducing jet velocity and jet completely covered on the surface.The results indicate that this configuration increased adiabatic effectiveness as blowing ratio increased.The spatially averaged adiabatic effectiveness reached 57.6% for at M=2.No observed film blow-offat all blowing ratios.The adiabatic film effectiveness of dual trench case outperformed the narrow trench case,laidback fan-shaped hole,fan-shaped hole and cylinder hole at different blowing ratios.

  2. Transonic Drag Reduction Through Trailing-Edge Blowing on the FAST-MAC Circulation Control Model

    Science.gov (United States)

    Chan, David T.; Jones, Gregory S.; Milholen, William E., II; Goodliff, Scott L.

    2017-01-01

    A third wind tunnel test of the FAST-MAC circulation control semi-span model was completed in the National Transonic Facility at the NASA Langley Research Center where the model was configured for transonic testing of the cruise configuration with 0deg flap detection to determine the potential for transonic drag reduction with the circulation control blowing. The model allowed independent control of four circulation control plenums producing a high momentum jet from a blowing slot near the wing trailing edge that was directed over a 15% chord simple-hinged ap. Recent upgrades to transonic semi-span flow control testing at the NTF have demonstrated an improvement to overall data repeatability, particularly for the drag measurement, that allows for increased confidence in the data results. The static thrust generated by the blowing slot was removed from the wind-on data using force and moment balance data from wind-o thrust tares. This paper discusses the impact of the trailing-edge blowing to the transonic aerodynamics of the FAST-MAC model in the cruise configuration, where at flight Reynolds numbers, the thrust-removed corrected data showed that an overall drag reduction and increased aerodynamic efficiency was realized as a consequence of the blowing.

  3. On the effect of leading edge blowing on circulation control airfoil aerodynamics

    Science.gov (United States)

    Mclachlan, B. G.

    1987-01-01

    In the present context the term circulation control is used to denote a method of lift generation that utilizes tangential jet blowing over the upper surface of a rounded trailing edge airfoil to determine the location of the boundary layer separation points, thus setting an effective Kutta condition. At present little information exists on the flow structure generated by circulation control airfoils under leading edge blowing. Consequently, no theoretical methods exist to predict airfoil performance under such conditions. An experimental study of the flow field generated by a two dimensional circulation control airfoil under steady leading and trailing edge blowing was undertaken. The objective was to fundamentally understand the overall flow structure generated and its relation to airfoil performance. Flow visualization was performed to define the overall flow field structure. Measurements of the airfoil forces were also made to provide a correlation of the observed flow field structure to airfoil performance. Preliminary results are presented, specifically on the effect on the flow field structure of leading edge blowing, alone and in conjunction with trailing edge blowing.

  4. RESEARCH ON THE INFLUENCE OF BLOWING AGENT ON SELECTED PROPERTIES OF EXTRUDED CELLULAR PRODUCTS

    Directory of Open Access Journals (Sweden)

    Tomasz Garbacz

    2015-11-01

    Full Text Available As a part of a more comprehensive research project, the present study was undertaken to investigate the effect of the type and content of blowing agents in the polymeric materials being processed on the structure and selected physical and mechanical properties of the obtained extrusion parts. In the experiment, the content of the blowing agent (0–2.0% by mass, fed into the processed polymer were adopted as a variable factor. In the studies presented in the article, the blowing agents of endothermic decomposition characteristics (Hydrocerol BIH 70, Hydrocerol BM 70 and the exothermic decomposition characteristics (PLC 751 occurring in the granulated form with a diameter of 1.2 to 1.8 mm were used. Based on the results of investigating porosity, porous structure image analysis as well as microscopic examination of the structure, it has been found that the favorable content of the blowing agent in the polymeric material should be of up to 0.8% by mass. With such a content of the blowing agent in the polymeric material, favorable strength properties are retained in porous parts, the pore distribution is uniform and the pores have similar sizes.

  5. Molecular identification of blow flies recovered from human cadavers during crime scene investigations in Malaysia.

    Science.gov (United States)

    Kavitha, Rajagopal; Nazni, Wasi Ahmad; Tan, Tian Chye; Lee, Han Lim; Isa, Mohd Noor Mat; Azirun, Mohd Sofian

    2012-12-01

    Forensic entomology applies knowledge about insects associated with decedent in crime scene investigation. It is possible to calculate a minimum postmortem interval (PMI) by determining the age and species of the oldest blow fly larvae feeding on decedent. This study was conducted in Malaysia to identify maggot specimens collected during crime scene investigations. The usefulness of the molecular and morphological approach in species identifications was evaluated in 10 morphologically identified blow fly larvae sampled from 10 different crime scenes in Malaysia. The molecular identification method involved the sequencing of a total length of 2.2 kilo base pairs encompassing the 'barcode' fragments of the mitochondrial cytochrome oxidase I (COI), cytochrome oxidase II (COII) and t-RNA leucine genes. Phylogenetic analyses confirmed the presence of Chrysomya megacephala, Chrysomya rufifacies and Chrysomya nigripes. In addition, one unidentified blow fly species was found based on phylogenetic tree analysis.

  6. LIMITING BEHAVIOR OF BLOW-UP SOLUTIONS OF THE NLSE WITH A STARK POTENTIAL

    Institute of Scientific and Technical Information of China (English)

    Zhu Shihui; Zhang Jian

    2012-01-01

    This article is concerned with blow-up solutions of the Cauchy problem of critical nonlinear Schr(o)dinger equation with a Stark potential.By using the variational characterization of corresponding ground state,the limiting behavior of blow-up solutions with critical and small super-critical mass are obtained in the natural energy space ∑ ={u ∈ H1; ∫RN [x|2|u|2dx < +o}.Moreover,an interesting concentration property of the blow-up solutions with critical mass is gotten,which reads that |u(t,x)|2→‖Q‖2L2δx =x1 as t→ T.

  7. Investigating the potential of fluorescent fingerprint powders as a marker for blow fly larvae (Diptera: calliphoridae).

    Science.gov (United States)

    Rosati, Jennifer Y; Robinson, Scott D; Devine, Richard

    2015-05-01

    Four fluorescent fingerprint powders (RedWop(™) , GreenWop(™) , Basic Yellow(™) , and Yellow Powder(™) ) were evaluated as a marker for blow fly larvae. Administration methods included ingestion (high vs. low concentration) or topical. Ingestion of high concentrations of Basic Yellow(™) and RedWop(™) caused higher larval mortality. Basic Yellow(™) delayed development and adult emergence while RedWop(™) and Yellow Powder(™) had a significant effect on particular stages of development, however, emergence time was not altered. Optimal administration is through ingestion at low concentration levels (powders was 450 nm. This research can aid in investigative training to increase visibility of larval and pupal blow flies. It can also be used in entomological studies to differentiate between larval blow flies (or other dipteran) species or individuals to further understand complex interactions and behavior during larval development.

  8. On wake response to asymmetric blowing in spurts from a blunt trailing edge

    Indian Academy of Sciences (India)

    S D Sharma; R R Pant

    2007-02-01

    In the present investigation, a technique has experimentally been evolved with the aim to control the unsteady wake dominated by periodic vortexshedding. The technique uses pulsating surface blowing that is applied asymmetrically just before separation from the blunt trailing edge of a thick aerofoil model. Thus, momentum is injected in spurts in only one of the two separated shear layers. The control parameters are the mass flow rate and the forcing frequency of the pulsating blowing. The technique is particularly effective in suppressing the vortex-shedding when the blowing is moderate and the forcing frequency is twice the natural vortex-shedding frequency. As a consequence of injecting momentum in spurts, there is a significant saving in mass flow required to achieve a condition of the momentumless wake. In spite of the initial conditions being strongly asymmetric, the flow pattern in the wake was observed to quickly assume a remarkable symmetry.

  9. Controlled Transverse Blow-up of Highenergy Proton Beams for Aperture Measurements and Loss Maps

    CERN Document Server

    Hӧfle, W; Redaelli, S; Schmidt, R; Valuch, D; Wollmann, D; Zerlauth, M

    2012-01-01

    A technique was developed to blow-up transversely in a controlled way high energy proton beams in the LHC. The technique is based on band limited white noise excitation that is injected into the transverse damper feedback loop. The injected signal can be gated to selectively blow-up individual trains of bunches. The speed of transverse blow-up can be precisely controlled. This opens the possibility to perform safely and efficiently aperture measurements and loss maps with high intensity bunch trains well above stored beam energies that are considered to be safe. In particular, lengthy procedures for measurements at top energy, otherwise requiring multiple fills of individual bunches, can be avoided. In this paper, the method is presented and results from beam measurements are discussed and compared with alternative blowup methods.

  10. 一类具阻尼的非线性双曲方程解的blow-up%The blow-up of solutions of a class of nonlinear damped hyperbolic equation

    Institute of Scientific and Technical Information of China (English)

    呼青英; 陆军

    2003-01-01

    The blow-up property of a nonlinear damped hyperbolic equation,which describes the motion of the neo-Hookean elastomer rod,is proven.%本文讨论了一类描述新胡克弹性杆运动的具阻尼的非线性双曲方程解的blow up性质.

  11. Developing and teaching the virtue-ethics foundations of healthcare whistle blowing.

    Science.gov (United States)

    Faunce, Thomas

    2004-10-01

    Healthcare whistle blowing, despite the benefits it has brought to healthcare systems in many developed countries, remains generally regarded as a pariah activity by many of the most influential healthcare professionals and regulatory institutions. Few if any medical schools or law department health law and bioethics classes, teach whistle blowing in a formal sense. Yet without exception, public inquiries initiated by healthcare whistle blowers have validated their central allegations and demonstrated that the whistle blowers themselves were sincere in their desire to implement the fundamental virtues and principles of medical ethics, bioethics and public health law. In many jurisdictions, the law, this time remarkably in advance of professional opinion, has offered legislative protection for reasonable allegations of whistleblowers made in good faith and in the public interest concerning a substantial and imminent threat to public safety. One reason for this paradoxical position, explored here, is that healthcare whistle blowing lacks a firm virtue-based theoretical bioethical and jurisprudential foundation. The hypothesis discussed is that the lack of this bioethical and jurisprudential substrate has contributed to a situation where healthcare whistle blowing suffers in terms of institutional support due to its lack of academic legitimacy. This article commences the process of redressing this imbalance by attempting to lay the theoretical foundations for healthcare whistle blowing. As a case study, this article concludes by discussing the Personal and Professional Development course at the ANU Medical School where healthcare whistle blowing is a formal part of a virtue-based curriculum that emphasises the foundational importance of conscience. Illustrative elements of that program are discussed.

  12. Microbial effects on the development of forensically important blow fly species.

    Science.gov (United States)

    Crooks, Esther R; Bulling, Mark T; Barnes, Kate M

    2016-09-01

    Colonisation times and development rates of specific blow fly species are used to estimate the minimum Post Mortem Interval (mPMI). The presence or absence of bacteria on a corpse can potentially affect the development and survival of blow fly larvae. Therefore an understanding of microbial-insect interactions is important for improving the interpretation of mPMI estimations. In this study, the effect of two bacteria (Escherichia coli and Staphylococcus aureus) on the growth rate and survival of three forensically important blow fly species (Lucilia sericata, Calliphora vicina and Calliphora vomitoria) was investigated. Sterile larvae were raised in a controlled environment (16:8h day: night light cycle, 23:21°C day: night temperature cycle and a constant 35% relative humidity) on four artificial diets prepared with 100μl of 10(5) CFU bacterial solutions as follows: (1) E. coli, (2) S. aureus, (3) a 50:50 E. coli:S. aureus mix and (4) a sterile bacteria-free control diet. Daily measurements (length, width and weight) were taken from first instar larvae through to the emergence of adult flies. Survival rates were also determined at pupation and adult emergence. Results indicate that bacteria were not essential for the development of any of the blow fly species. However, larval growth rates were affected by bacterial diet, with effects differing between blow fly species. Peak larval weights also varied according to species-diet combination; C. vomitoria had the largest weight on E. coli and mixed diets, C. vicina had the largest weight on S. aureus diets, and treatment had no significant effect on the peak larval weight of L. sericata. These results indicate the potential for the bacteria that larvae are exposed to during development on a corpse to alter both developmental rates and larval weight in some blow fly species.

  13. Investigations of transonic buffet control on civil aircraft wing with the use of tangential jet blowing

    Science.gov (United States)

    Abramova, K. A.; Petrov, A. V.; Potapchick, A. V.; Soudakov, V. G.

    2016-10-01

    Numerical and experimental investigations of transonic buffet control by tangential jet blowing are presented. To suppress the shock-induced boundary layer separation and the buffet at transonic speeds, compressed air jet is blown through a small slot nozzle tangentially to the upper surface of the supercritical airfoil. Numerical simulations were carried out on the basis of the unsteady Reynolds averaged Navier-Stokes (URANS) equations. Experimental studies of the tangential jet blowing were performed in the transonic wind tunnel T-112 of TsAGI. Results show that the jet moves the shock downstream, increases lift, suppresses flow separation under shock foot and delays buffet onset.

  14. Blow-Up Analysis for a Quasilinear Degenerate Parabolic Equation with Strongly Nonlinear Source

    Directory of Open Access Journals (Sweden)

    Pan Zheng

    2012-01-01

    Full Text Available We investigate the blow-up properties of the positive solution of the Cauchy problem for a quasilinear degenerate parabolic equation with strongly nonlinear source ut=div(|∇um|p−2∇ul+uq,  (x,t∈RN×(0,T, where N≥1, p>2 , and m, l,  q>1, and give a secondary critical exponent on the decay asymptotic behavior of an initial value at infinity for the existence and nonexistence of global solutions of the Cauchy problem. Moreover, under some suitable conditions we prove single-point blow-up for a large class of radial decreasing solutions.

  15. THE SIMULTANEOUS AND NON-SIMULTANEOUS BLOW-UP CRITERIA FOR A DIFFUSION SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Zhengqiu LING; Zejia WANG; Guoqiang ZHANG

    2013-01-01

    This paper investigates the finite time blow-up of nonnegative solutions for a nonlinear diffusion system with a more complicated source term,which is a product of localized source,local source,and weight function,and complemented by homogeneous Dirichlet boundary conditions.The criteria are proposed to identify simultaneous and nonsimultaneous blow-up solutions.Moreover,the related classification for the four parameters in the model is optimal and complete.The results extend those in Zhang and Yang [12].

  16. Blow-up phenomena and persistence property for the modified b-family of equations

    Science.gov (United States)

    Wang, Ying; Zhu, Min

    2017-02-01

    In this paper, we study the blow-up mechanism and persistence property of solutions to the modified b-family of equations. The dynamics of the blow-up quantity along the characteristics is established by the Riccati-type differential inequality with various parameters. The key feature of the method is to refine the analysis on the growth rate of the relative ratio between solution and its gradient by performing a vertical shift. Furthermore, the persistence results for the solution are established in weighted spaces.

  17. Design on curves of wall-thickness for Blow Molding Machine based on HMI

    Directory of Open Access Journals (Sweden)

    Cheng Yayun

    2015-01-01

    Full Text Available Properly control of blow molding machine’s wall-thickness relates to the quality of plastic products,design on curves is the key technology of blow molding machine’s wall-thickness control.Adopted cubic spline curve as a fitting prototype,used advanced HMI as a design platform,by cooperation with HMI configuration function and macro code,an interface of curves was designed,a good performance of human-computer interaction and core data’s transmission in the whole machine were realized.By using this method,the integration of the system was increased and costs was reduced dramatically.

  18. Numerical Simulation of the Air Jet Flow Field in the Melt Blowing Process

    Institute of Scientific and Technical Information of China (English)

    CHEN Ting; HUANG Xiu-bao

    2002-01-01

    The theoretical model of the flow field of the dual slot die in melt blowing process is founded. The model is solved numerically with finite difference method. The distributions of the air velocity component in x direction along x-axis and y-axis and the air temperature distributions along x-axis and y-axis are obtained via numerical computation. The computation results coincide with the experimental data given by Harpham and Shambaugh. The distributions of the air velocity and air temperature are introduced into the air drag model of melt blowing. The model prediction of the fiber diameter agrees with the experimental data well.

  19. Blow-up conditions for two dimensional modified Euler-Poisson equations

    Science.gov (United States)

    Lee, Yongki

    2016-09-01

    The multi-dimensional Euler-Poisson system describes the dynamic behavior of many important physical flows, yet as a hyperbolic system its solution can blow-up for some initial configurations. This article strives to advance our understanding on the critical threshold phenomena through the study of a two-dimensional modified Euler-Poisson system with a modified Riesz transform where the singularity at the origin is removed. We identify upper-thresholds for finite time blow-up of solutions for the modified Euler-Poisson equations with attractive/repulsive forcing.

  20. Investigations on the processing of solid silicon rubber in blow moulding

    Science.gov (United States)

    Hopmann, Ch.; Funk, A.; Windeck, C.

    2015-05-01

    Complex hollow parts made of thermoplastics are often produced in the extrusion blow moulding process. This cost-efficient production technique with a high reproducibility, a high degree of automation and short cycle times has not been adapted for rubber processing until now. Current research activities at IKV focus on the processing of silicone rubber in extrusion blow moulding with an adapted processing and rapid cross-linking systems. The blow moulding process allows an automated and effective production of complex hollow parts made of solid silicone rubber in one step. The use of expensive core techniques, which lead to comparatively high reject rates in injection moulding, is not necessary. Expensive and time-consuming assembly steps can be reduced. This substantially increases the efficiency of the process. A systematic material selection of different solid silicone rubber compounds and cross-linking systems for the extrusion blow moulding process is a major focus of investigation. In this context, the term blow mouldability of polymers is defined and the suitability of solid silicone rubbers in combination with cross-linking systems for the blow moulding process is analysed. Characteristic mechanical and physical properties allow the identification of suitable material systems and give advice for the implementation of the new process. Extrusion blow moulding of solid silicone rubber is a new and innovative manufacturing concept to produce elastomeric hollow parts. Influences on the forming process are not known for silicone rubber yet. Therefore, to obtain a detailed process description is another focus of the research project. This includes the forming process, the processing and the influences of the material and the curing reaction on the processing. In the first instance, the investigation and description of the forming process as well as the detailed analysis of the processing parameters, such as curing time, mould temperature, wall thickness of the

  1. Blow-up of Solution for the Nonlinear Sobolev-Galpern Equation%非线性Sobolev-Galpern型方程解的Blow-up性质

    Institute of Scientific and Technical Information of China (English)

    张恩彪; 江成顺

    2009-01-01

    In this paper,the initial boundary value problems of the nonlinear Sobolev Galpern equation are studied.The existence,uniqueness of local solution for the problem are obtained by means of a special Green's function and the contraction mapping principle.Finally,the blow-up of solution in finite time under some assumed conditions is proved with the aid of Jensen's inequality.

  2. Near-surface snow particle dynamics from particle tracking velocimetry and turbulence measurements during alpine blowing snow storms

    Science.gov (United States)

    Aksamit, Nikolas O.; Pomeroy, John W.

    2016-12-01

    Many blowing snow conceptual and predictive models have been based on simplified two-phase flow dynamics derived from time-averaged observations of bulk flow conditions in blowing snow storms. Measurements from the first outdoor application of particle tracking velocimetry (PTV) of near-surface blowing snow yield new information on mechanisms for blowing snow initiation, entrainment, and rebound, whilst also confirming some findings from wind tunnel observations. Blowing snow particle movement is influenced by complex surface flow dynamics, including saltation development from creep that has not previously been measured for snow. Comparisons with 3-D atmospheric turbulence measurements show that blowing snow particle motion immediately above the snow surface responds strongly to high-frequency turbulent motions. Momentum exchange from wind to the dense near-surface particle-laden flow appears significant and makes an important contribution to blowing snow mass flux and saltation initiation dynamics. The more complete and accurate description of near-surface snow particle motions observable using PTV may prove useful for improving blowing snow model realism and accuracy.

  3. Research and Analysis on the Physical and Chemical Properties of Molten Bath with Bottom-Blowing in EAF Steelmaking Process

    Science.gov (United States)

    Wei, Guangsheng; Zhu, Rong; Dong, Kai; Ma, Guohong; Cheng, Ting

    2016-10-01

    Bottom-blowing technology is widely adopted in electric arc furnace (EAF) steelmaking to promote the molten bath fluid flow, accelerate the metallurgical reaction, and improve the quality of molten steel. In this study, a water model experiment and a computational fluid dynamics model were established to investigate the effects of bottom-blowing gas flow rate on the fluid flow characteristics in the EAF molten bath. The results show that the interaction among the bottom-blowing gas streams influences the molten bath flow field, and increasing the bottom-blowing gas flow rate can accelerate the fluid flow and decrease the volume of the dead zone. Based on industrial application research, the physical and chemical properties of the molten bath with bottom-blowing were analyzed. Compared with traditional melting conditions without bottom-blowing, bottom-blowing technology demonstrates obvious advantages in promoting the heat transfer and metallurgical reactions in the molten bath. With the bottom-blowing arrangement, the dephosphorization and decarburization rates are accelerated, the contents of FeO and T. Fe in endpoint slag are decreased, and the endpoint carbon-oxygen equilibrium of molten steel is improved.

  4. Draft Genome Sequence of Clostridium tyrobutyricum Strain UC7086, Isolated from Grana Padano Cheese with Late-Blowing Defect.

    Science.gov (United States)

    Bassi, Daniela; Fontana, Cecilia; Gazzola, Simona; Pietta, Ester; Puglisi, Edoardo; Cappa, Fabrizio; Cocconcelli, Pier Sandro

    2013-08-15

    Clostridium tyrobutyricum is considered the main agent of late-blowing defect in the production of hard cheese. Here, we described the draft genome sequences and annotation of C. tyrobutyricum strain UC7086, which was isolated from Grana Padano cheese with blowing defect, and C. tyrobutyricum DSM 2637 type strain in a comparative study.

  5. Draft Genome Sequence of Clostridium tyrobutyricum Strain UC7086, Isolated from Grana Padano Cheese with Late-Blowing Defect

    OpenAIRE

    Bassi, Daniela; Fontana, Cecilia; Gazzola, Simona; Pietta, Ester; Puglisi, Edoardo; Cappa, Fabrizio; Cocconcelli, Pier Sandro

    2013-01-01

    Clostridium tyrobutyricum is considered the main agent of late-blowing defect in the production of hard cheese. Here, we described the draft genome sequences and annotation of C. tyrobutyricum strain UC7086, which was isolated from Grana Padano cheese with blowing defect, and C. tyrobutyricum DSM 2637 type strain in a comparative study.

  6. A BLOW-UP CRITERION FOR 3-D NON-RESISTIVE COMPRESSIBLE HEAT-CONDUCTIVE MAGNETOHYDRODYNAMIC EQUATIONS WITH INITIAL VACUUM

    Institute of Scientific and Technical Information of China (English)

    Xu Xinying

    2012-01-01

    In this paper; we prove a blow-up criterion of strong solutions to the 3-D viscous and non-resistive magnetohydrodynamic equations for compressible heat-conducting flows with initial vacuum.This blow-up criterion depends only on the gradient of velocity and the temperature,which is similar to the one for compressible Navier-Stokes equations.

  7. Investigating influence of the magnetic arc blow in multi-break vacuum circuit breakers

    Science.gov (United States)

    Liao, Minfu; Ge, Guowei; Duan, Xiongying; Huang, Zhihui; Zou, Jiyan

    2016-12-01

    This paper investigates the influence of the interactive magnetic field in multi-break vacuum circuit breakers (VCBs) on the arc plasma and the post-arc characteristics. The magnetic field of multi-break VCBs is asymmetric and off-center because of the interactive magnetic field, which is also called bias magnetic field (BMF). The BMF distribution of double-break VCBs is gained by electromagnetic analysis. The test circuit of the magnetic arc blow in multi-break VCBs is established by simplifying as the interaction between the vacuum arc and the BMF. The influence of the magnetic arc blow on the arc plasma is studied by the high-speed CMOS camera and the post-arc current measure. While the vacuum arc is in the direction of the Ampere force with the BMF at 200 mT, it is in the retrograde direction when the BMF is below 100 mT, which results in the post-arc charge obviously varying from 9 μC to 50 μC. The relationship between the BMF and the post arc charge is gained. The mechanism of the magnetic arc blow in multi-break VCBs is discussed. Therefore, this paper can provide the base of construct and configuration to avoid the influence of the magnetic arc blow.

  8. Resection and primary anastomosis with or without modified blow-hole colostomy for sigmoid vovulus

    Institute of Scientific and Technical Information of China (English)

    Sacid Coban; Mehmet Yilmaz; Alpaslan Terzi; Fahrettin Yildiz; Dincer Ozgor; Cengiz Ara; Saim Yologlu; Vedat Kirimlioglu

    2008-01-01

    AIM: To evaluate the efficacy of resection and primary anastomosis (RPA) and RPA with modified blow-hole colostomy for sigmoid volvulus.METHODS: From March 2000 to September 2007,77 patients with acute sigmoid volvulus were treated.A total of 47 patients underwent RPA or RPA with modified blow-hole colostomy.Twenty-five patients received RPA (Group A),and the remaining 22 patients had RPA with modified blow-hole colostomy (Group B).The clinical course and postoperative complications of the two groups were compared.RESULTS: The mean hospital stay,wound infection and mortality did not differ significantly between the groups.Superficial wound infection rate was higher in group A (32% vs 9.1%).Anastomotic leakage was observed only in group A,with a rate of 6.3%.The difference was numerically impressive but was statistically not significant.CONCLUSION: RPA with modified blow-hole colostomy provides satisfactory results.It is easy to perform and may become a method of choice in patients with sigmoid volvulus.Further studies are required to further establish its role in the treatment of sigmoid volvulus.

  9. Blow-up estimates for semilinear parabolic systems coupled in an equation and a boundary condition

    Institute of Scientific and Technical Information of China (English)

    WANG; Mingxin(

    2001-01-01

    [1]Wang, S., Wang, M. X., Xie, C. H., Reaction-diffusion systems with nonlinear boundary conditions, Z. angew. Math.Phys., 1997, 48(6): 994-1001.[2]Fila, M., Quittner, P., The blow-up rate for a semilinear parabolic system, J. Math. Anal. Appl., 1999, 238: 468-476.[3]Hu, B., Remarks on the blow-up estimate for solutions of the heat equation with a nonlinear boundary condition, Differential Integral Equations, 1996, 9(5): 891-901.[4]Hu, B. , Yin, H. M., The profile near blow-up time for solution of the heat equation with a nonlinear boundary condition,Trans. of Amer. Math. Soc., 1994, 346: 117-135.[5]Amann, H., Parabolic equations and nonlinear boundary conditions, J. of Diff. Eqns., 1988, 72: 201-269.[6]Deng, K., Blow-up rates for parabolic systems, Z. angew. Math. Phys. ,1996, 47: 132-143.[7]Fila, M., Levine, H. A., On critical exponents for a semilinear parabolic system coupled in an equation and a boundary condition, J. Math. Anal. Appl., 1996, 204: 494-521.

  10. Blow-Up for a Semi-linear Advection-Diffusion System with Energy Conservation

    Institute of Scientific and Technical Information of China (English)

    Dapeng DU; Jing L(U)

    2009-01-01

    The authors study radial solutions to a model equation for the Navier-Stokes equations.It is shown that the model equation has self-similar singular solution if 5 ≤ n ≤9.It is also shown that the solution will blow up if the initial data is radial,large enough and n ≥ 5.

  11. What Actions Can Be Taken to Increase Whistle-Blowing in the Classroom?

    Science.gov (United States)

    Bernardi, Richard A.; Landry, Alexandra C.; Landry, Erynne E.; Buonafede, Mitchell R.; Berardi, Marissa E.

    2016-01-01

    This study surveyed undergraduate business students on various issues concerning the potential of students whistle-blowing when they observe other students cheating. Developing the courage of one's conviction in our accounting students is important to accounting educators as we are also emphasizing traits such as integrity, skepticism, and…

  12. Blow-up in nonlinear Schroedinger equations. I. A general review

    DEFF Research Database (Denmark)

    Juul Rasmussen, Jens; Rypdal, K.

    1986-01-01

    The general properties of a class of nonlinear Schroedinger equations: iut + p:∇∇u + f(|u|2)u = 0 are reviewed. Conditions for existence, uniqueness, and stability of solitary wave solutions are presented, along with conditions for blow-up and global existence for the Cauchy problem....

  13. Academic Misconduct: A Goals-Plans-Action Approach to Peer Confrontation and Whistle-Blowing

    Science.gov (United States)

    Henningsen, Mary Lynn Miller; Valde, Kathleen S.; Denbow, Jessica

    2013-01-01

    Academic misconduct is a serious, pervasive, communication phenomenon on college campuses. In this study, the goals-plans-action model (Dillard, 1990) was used as a theoretical framework to investigate peer confrontation of cheating and whistle-blowing to a course instructor. In an experiment, participants were asked to respond to measures of…

  14. Generalized Nehari functionals and finite time blow up of the solutions to Boussinesq equation

    Science.gov (United States)

    Kolkovska, N.; Dimova, M.; Kutev, N.

    2015-10-01

    We study the Cauchy problem to generalized Boussinesq equation with linear restoring force and combined power type nonlinearities. Generalized Nehari functionals are introduced and their monotonicity and sign preserving properties are established. By means of an extension of the concavity method of Levine and generalized Nehari functionals finite time blow up of the solutions with arbitrary high positive initial energy is proved.

  15. Blow-up criterion for the zero-diffusive Boussinesq equations via the velocity components

    Directory of Open Access Journals (Sweden)

    Weihua Wang

    2015-03-01

    Full Text Available This article concerns the blow up for the smooth solutions of the three-dimensional Boussinesq equations with zero diffusivity. It is shown that if any two components of the velocity field $u$ satisfy $$ \\int_0^T \\frac{ \\||u_1|+|u_2|\\|^q_{L^{p,\\infty}} } {1+\\ln ( e+\\|\

  16. Magnetic virial identities and applications to blow-up for Schroedinger and wave equations

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Andoni, E-mail: andoni.garcia@ehu.es [Departamento de Matematicas, Universidad del Pais Vasco, Apartado 644, 48080 Bilbao (Spain)

    2012-01-13

    We prove blow-up results for the solution of the initial-value problem with negative energy of the focusing mass-critical and supercritical nonlinear Schroedinger and the focusing energy-subcritical nonlinear wave equations with electromagnetic potential. (paper)

  17. A Paradigm for Operant Conditioning in Blow Flies ("Phormia Terrae Novae" Robineau-Desvoidy, 1830)

    Science.gov (United States)

    Sokolowski, Michel B. C.; Disma, Gerald; Abramson, Charles I.

    2010-01-01

    An operant conditioning situation for the blow fly ("Protophormia terrae novae") is described. Individual flies are trained to enter and reenter a hole as the operant response. Only a few sessions of contingent reinforcement are required to increase response rates. When the response is no longer followed by food, the rate of entering the hole…

  18. Straightforward factors for predicting the prognosis of blow-out fractures.

    Science.gov (United States)

    Higashino, Takuya; Hirabayashi, Shinichi; Eguchi, Tomoaki; Kato, Yuki

    2011-07-01

    In blow-out fractures, some nonoperative cases have a poor outcome, and a method for accurate prognosis is required. To address this need, we retrospectively reviewed blow-out fractures presenting at Teikyo University Hospital between July 2004 and May 2007 and conducted a survey regarding diplopia and enophthalmos for nonoperative cases. Computed tomographic scan findings were divided according to fracture width and the degree of protrusion of the inferior rectus muscle into the maxillary sinus. We had 106 patients presenting with blow-out fractures, and 89 patients had been treated nonoperatively. In medial orbital wall fractures, no patient had diplopia, and 1 patient had enophthalmos after nonoperative treatment. In punched-out orbital floor fractures, all cases had diplopia when the fracture width was less than half the diameter of the globe, and the protrusion of the inferior rectus muscle into the maxillary sinus was half or more of its section. Even if the fracture width was less than half the diameter of the globe, 2 of 3 patients had enophthalmos when the protrusion of the inferior rectus muscle into the maxillary sinus was half or more of its section. Among the linear orbital floor fractures, 1 case required an emergency operation. We suggest a new algorithm for treatment of blow-out fractures based on computed tomographic scan findings that can also contribute to making a prognosis.

  19. Solution blow spun Poly(lactic acid)/Hydroxypropyl methylcellulose nanofibers with antimicrobial properties

    Science.gov (United States)

    Poly(lactic acid) (PLA) nanofibers containing hydroxypropyl methylcellulose (HPMC) and tetracycline hydrochloride (THC) were solution blow spun from two different solvents, chloroform/acetone (CA, 80:20 v/v) and 2,2,2-triflouroethanol (TFE). The diameter distribution, chemical, thermal, thermal stab...

  20. A review of bacterial interactions with blow flies (Diptera: Calliphoridae) of medical, veterinary, and forensic importance

    Science.gov (United States)

    Blow flies are commonly associated with decomposing material. In most cases, the larvae are found feeding on decomposing vertebrate remains. However, some species have specialized to feed on living tissue or can survive on other alternate resources like feces. Because of their affiliation with su...

  1. Blow-out of nonpremixed turbulent jet flames at sub-atmospheric pressures

    KAUST Repository

    Wang, Qiang

    2016-12-09

    Blow-out limits of nonpremixed turbulent jet flames in quiescent air at sub-atmospheric pressures (50–100 kPa) were studied experimentally using propane fuel with nozzle diameters ranging 0.8–4 mm. Results showed that the fuel jet velocity at blow-out limit increased with increasing ambient pressure and nozzle diameter. A Damköhler (Da) number based model was adopted, defined as the ratio of characteristic mixing time and characteristic reaction time, to include the effect of pressure considering the variations in laminar burning velocity and thermal diffusivity with pressure. The critical lift-off height at blow-out, representing a characteristic length scale for mixing, had a linear relationship with the theoretically predicted stoichiometric location along the jet axis, which had a weak dependence on ambient pressure. The characteristic mixing time (critical lift-off height divided by jet velocity) adjusted to the characteristic reaction time such that the critical Damköhler at blow-out conditions maintained a constant value when varying the ambient pressure.

  2. Magang‘s 20 t Top Blowing BOF Used for Extracting Vanadium

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Because that vanadium sells well recently in market and the Maagng's iron ore ontains higher vanadium,Magang decied to use its 20 t top blowing BOF to extract vanadium in steel-makin.Production result showed that the extracted vanadium slag reached the expected target of V2O3 compsoition.The recovery rate of vanadium is up to 80%

  3. Effects of Blowing Ratio Measured by Liquid Crystal on Heat Transfer Characteristics of Trailing Edge Cutback

    Institute of Scientific and Technical Information of China (English)

    Yuan Hepeng; Zhu Huiren; Kong Manzhao

    2008-01-01

    This article deals with the effects of a blowing ratio measured with narrowbend liquid crystal in transonic experiments on the heat transfer characteristics of trailing edge cutback. The experimental results are compared end contrasted in terms of available data for tra-ditional experiments with thermocouples. It is concluded that the blowing ratio exerts rather significant effects on film cooling effec-tiveness distribution of the rib center line. As the blowing ratio decreases, similar to the cooling effectiveness distribution curve of the slot center line, that of the rib center line makes a clockwise rotation about the end. When the blowing ratio increases, the regular film cooling effectiveness curve of the surface becomes rather smooth. On the whole measuring surface, the most intensive heat transfer oc-curs at the extended borderline of the slot end the rib, neither at the rib center line nor at the slot center line. The experimental results of cooling effectiveness measured with thermocouples are lower than those with liquid crystal. In addition, the transient experiments using narrowband liquid crystal can eliminate the higher errors of Nusselt numbers in measurements with thermocouples at the slot outlet.

  4. Film Cooling from Two Staggered Rows of Compound Angle Holes at High Blowing Ratios

    Directory of Open Access Journals (Sweden)

    Phillip M. Ligrani

    1996-01-01

    Full Text Available Experimental results are presented which describe the development and structure of flow downstream of two staggered rows of film-cooling holes with compound angle orientations at high blowing ratios. These film cooling configurations are important because they are frequently employed on the first stage of rotating blades of operating gas turbine engines. With this configuration, holes are spaced 3d apart in the spanwise direction, with inclination angles of 24 degrees, and angles of orientation of 50.5 degrees. Blowing ratios range from 0.5 to 4.0 and the ratio of injectant to freestream density is near 1.0. Results show that spanwise averaged adiabatic effectiveness, spanwise-averaged iso-energetic Stanton number ratios, surveys of streamwise mean velocity, and surveys of injectant distributions change by important amounts as the blowing ratio increases. This is due to injectant lift-off from the test surface just downstream of the holes which becomes more pronounced as blowing ratio increases.

  5. A test of Automatic Blowing snow Station (ABS) in the French Alps

    Science.gov (United States)

    Ito, Yoichi; Naaim-Bouvet, Florence; Nishimura, Kouichi; Bellot, Hervé; Fontaine, Firmin

    2015-04-01

    Blowing snow is a significant factor to estimate snow distribution in alpine, Arctic and Antarctic regions. The Snow Particle Counter (SPC) is well used for mass flux measurement of the blowing snow, however, the SPC deployment is not always possible for automatic observation under harsh conditions. Recently Automatic Blowing snow Station (ABS), which is a simpler device than the SPC, have been developed in Japan. We installed the ABS system with the SPCs at the Lac Blanc Pass in the French Alps (2700 m a.s.l.) to examine the relationship between the ABS output and snow particle mass flux. The ABS worked well, without problems, for the entire 4-month period in the winter 2014. The ABS output was converted to mass flux using wind-dependent power function which obtained from calibration procedure in a cold wind-tunnel. The mass flux obtained from the ABS showed a good agreement with the SPC, particularly around the peak of blowing snow event. Based on tests under controlled (cold wind-tunnel) and field conditions, we conclude that the ABS is suitable for practical use.

  6. Finite time blow-up for a wave equation with a nonlocal nonlinearity

    CERN Document Server

    Fino, Ahmad; Georgiev, Vladimir

    2010-01-01

    In this article, we study the local existence of solutions for a wave equation with a nonlocal in time nonlinearity. Moreover, a blow-up results are proved under some conditions on the dimensional space, the initial data and the nonlinear forcing term.

  7. Synergistic Separation Behavior of Boron in Metallurgical Grade Silicon Using a Combined Slagging and Gas Blowing Refining Technique

    Science.gov (United States)

    Wu, Jijun; Zhou, Yeqiang; Ma, Wenhui; Xu, Min; Yang, Bin

    2017-02-01

    A combined slagging and gas blowing refining technique for boron removal from metallurgical grade silicon using the CaO-SiO2-CaCl2 slag and the mixed Ar-O2-H2O gas is investigated. The oxygen gas blowing in combination with water vapor shows a wonderful removal efficiency of boron compared with the single oxygen or the single water vapor blowing. It is analyzed from the thermodynamics that a synergistic separation behavior of boron is resulted from CaCl2 and O2. Boron is removed and reduced from 22 to 0.75 ppmw with a removal efficiency of 96.6 pct.

  8. Synergistic Separation Behavior of Boron in Metallurgical Grade Silicon Using a Combined Slagging and Gas Blowing Refining Technique

    Science.gov (United States)

    Wu, Jijun; Zhou, Yeqiang; Ma, Wenhui; Xu, Min; Yang, Bin

    2016-11-01

    A combined slagging and gas blowing refining technique for boron removal from metallurgical grade silicon using the CaO-SiO2-CaCl2 slag and the mixed Ar-O2-H2O gas is investigated. The oxygen gas blowing in combination with water vapor shows a wonderful removal efficiency of boron compared with the single oxygen or the single water vapor blowing. It is analyzed from the thermodynamics that a synergistic separation behavior of boron is resulted from CaCl2 and O2. Boron is removed and reduced from 22 to 0.75 ppmw with a removal efficiency of 96.6 pct.

  9. A Wind Tunnel Investigation of the Shear Stress with A Blowing Sand Cloud

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In a blowing sand system,the wind provides the driving forces for the particle movement while the moving particles exert the opposite forces to the wind by extracting its momentum.The wind-sand interaction that can be characterized by shear stress and force exerted on the wind by moving particles results in the modification of wind profiles.Detailed wind pro-files re-adapted to blown sand movement are measured in a wind tunnel for different grain size populations and at differ-ent free-stream wind velocities.The shear stress with a blowing sand cloud and force exerted on the wind by moving par-ticles are calculated from the measured wind velocity profiles.The results suggest that the wind profiles with presence of blowing sand cloud assume convex-upward curves on the u(z)-ln(z) plot compared with the straight lines characterizing the velocity profiles of clean wind,and they can be better fitted by power function than log-linear function.The exponent of the power function ranging from 0.1 to 0.17 tends to increase with an increase in wind velocity but decrease with an increase in particle size.The force per unit volume exerted on the wind by blown sand drift that is calculated based on the empirical power functions for the wind velocity profiles is found to decrease with height.The particle-induced force makes the total shear stress with blowing sand cloud partitioned into air-borne stress that results from the wind velocity gradient and grain-borne stress that results from the upward or downward movement of particles.The air-borne stress in-creases with an increase in height,while the grain-borne stress decreases with an increase in height.The air-borne shear stress at the top of sand cloud layer increases with both wind velocity and grain size,implying that it increases with sand transport rate for a given grain size.The shear stress with a blowing sand cloud is also closely related to the sand transport rate.Both the total shear stress and grain-borne stress on

  10. LHC MD 1087: Controlled Longitudinal Emittance Blow-up with Short Bunches

    CERN Document Server

    Timko, Helga; Esteban Muller, Juan; Jaussi, Michael; Lasheen, Alexandre; Shaposhnikova, Elena; CERN. Geneva. ATS Department

    2017-01-01

    The aim of the MD was to study the controlled longitudinal emittance blow-up applied during the ramp with bunches that are slightly shorter than operational. Earlier MDs in 2015 have shown that with a short target bunch length, the blow-up is less controlled and a bifurcation of bunch lengths occurs. The presented measurements show that the bifurcation is independent of the presence of the bunch length feedback, pointing towards an intensity-dependent phenomenon, originating from a synchrotron frequency shift with intensity. Accurate measurements of synchrotron frequency shift with intensity are presented as well. The measurements took place between 22nd August 2016, 19:00 and 23rd August 2016, 04:00.

  11. PSB beam longitudinal blow-up by phase modulation with the digital LLRF prototype system

    CERN Document Server

    Angoletta, M E; Butterworth, A; Findlay, A; Jaussi, M; Leinonen, P; Molendijk, J; Sanchez-Quesada, J

    2014-01-01

    The PSB will be upgraded to a new, Digital Low-Level RF (DLLRF) system in 2014 at the injectors’ restart after LS1. This DLLRF is an evolution of that successfully deployed in LEIR and comprises new hardware, software and implementation strategies. Machine development studies have been carried out in the PSB over recent years with the existing LEIR-style hardware installed in PSB ring four. These studies have allowed testing approaches and validating implementation strategies. This note focuses on a series of MDs carried out during the 2011 run where a new implementation of the longitudinal beam blow-up obtained by phase modulation was tested. Test results and effects on the beam are show for a CNGS-type beam. Finally, an overview is given of the final longitudinal blow-up implementation planned with the new hardware, which will be operationally deployed in 2014.

  12. Profile of Blow-up Solution to Hyperbolic System with Nonlocal Term

    Institute of Scientific and Technical Information of China (English)

    Zhi Wen DUAN; Kwang Ik KIM

    2007-01-01

    This paper is concerned with a nonlocal hyperbolic system as follows:utt=△u+(∫Ωvdx)p for x∈RN,t>0, utt=△v+(∫Ωvdx)q for x∈RN,t>0,u(x,0)=u0(x),ut(x,0)=u01(x) for x∈RN,v(x,0)=u0(x),vt(x,0)=v01(x) for x∈RN,where 1 ≤ N ≤ 3, p ≥ 1, q ≥ 1 and pq > 1. Here the initial values are compactly supported andΩ(∈) RN is a bounded open region. The blow-up curve, blow-up rate and profile of the solution arediscussed.

  13. Flap Gap Oscillatory Blowing on 2D and 2.5D Wing

    Directory of Open Access Journals (Sweden)

    Cătălin NAE

    2009-12-01

    Full Text Available Here we present preliminary results obtained in developing an active flow control system for highlift systems at advanced TRL level. The work is based on theoretical and experimental workperformed in AVERT EU FP6 project where the oscillatory flap gap blowing system was designedand tested on a INCAS F15 2D wing model. Pressure data and global loads have been recorded fora complex evaluation of the basic flow control mechanism. In 2.5D test cases this work has beenextended so that the proposed system may be selected as a mature technology in the JTI Clean Sky,Smart Fixed Wing Aircraft ITD. For this goal, new experimental setup was used and also updatedelectronics for the blowing system have been introduces. This was complemented by a newextension for the data acquisition system and visualization tools. Finally global correlations forbasic lift increments have been compared with the reference 2D case and analysed with respect tothe system efficiency.

  14. Method to reduce arc blow during DC arc welding of pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Espina-Hernandez, J. H.; Rueda-Morales, G.L.; Caleyo, F.; Hallen, J. M. [Instituto Politecnico Nacional, Mexico, (Mexico); Lopez-Montenegro, A.; Perz-Baruch, E. [Pemex Exploracion y Produccion, Tabasco, (Mexico)

    2010-07-01

    Steel pipelines are huge ferromagnetic structures and can be easily subjected to arc blow during the DC arc welding process. The development of methods to avoid arc blow during pipeline DC arc welding is a major objective in the pipeline industry. This study developed a simple procedure to compensate the residual magnetic field in the groove during DC arc welding. A Gaussmeter was used to perform magnetic flux density measurements in pipelines in southern Mexico. These data were used to perform magnetic finite element simulations using FEMM. Different variables were studied such as the residual magnetic field in the groove or the position of the coil with respect to the groove. An empirical predictive equation was developed from these trials to compensate for the residual magnetic field. A new method of compensating for the residual magnetic field in the groove by selecting the number of coil turns and the position of the coil with respect to the groove was established.

  15. Blow-up for an evolution p-laplace system with nonlocal sources and inner absorptions

    Directory of Open Access Journals (Sweden)

    Liu Dengming

    2011-01-01

    Full Text Available Abstract This paper investigates the blow-up properties of positive solutions to the following system of evolution p-Laplace equations with nonlocal sources and inner absorptions { u t − div ( | ∇ u | p − 2 ∇ u = ∫ Ω v m d x − α u r , x ∈ Ω ,   t > 0, v t − div ( | ∇ v | q − 2 ∇ v = ∫ Ω u n d x − β v s , x ∈ Ω ,   t > 0 with homogeneous Dirichlet boundary conditions in a smooth bounded domain Ω ∈ RN (N ≥ 1, where p, q > 2, m, n, r, s ≥ 1, α, β > 0. Under appropriate hypotheses, the authors discuss the global existence and blow-up of positive weak solutions by using a comparison principle. 2010 Mathematics Subject Classification: 35B35; 35K60; 35K65; 35K57.

  16. Gene expression during blow fly development: improving the precision of age estimates in forensic entomology.

    Science.gov (United States)

    Tarone, Aaron M; Foran, David R

    2011-01-01

    Forensic entomologists use size and developmental stage to estimate blow fly age, and from those, a postmortem interval. Since such estimates are generally accurate but often lack precision, particularly in the older developmental stages, alternative aging methods would be advantageous. Presented here is a means of incorporating developmentally regulated gene expression levels into traditional stage and size data, with a goal of more precisely estimating developmental age of immature Lucilia sericata. Generalized additive models of development showed improved statistical support compared to models that did not include gene expression data, resulting in an increase in estimate precision, especially for postfeeding third instars and pupae. The models were then used to make blind estimates of development for 86 immature L. sericata raised on rat carcasses. Overall, inclusion of gene expression data resulted in increased precision in aging blow flies.

  17. The blow-up problem for a semilinear parabolic equation with a potential

    Science.gov (United States)

    Cortazar, Carmen; Elgueta, Manuel; Rossi, Julio D.

    2007-11-01

    Let [Omega] be a bounded smooth domain in . We consider the problem ut=[Delta]u+V(x)up in [Omega]×[0,T), with Dirichlet boundary conditions u=0 on [not partial differential][Omega]×[0,T) and initial datum u(x,0)=M[phi](x) where M[greater-or-equal, slanted]0, [phi] is positive and compatible with the boundary condition. We give estimates for the blow-up time of solutions for large values of M. As a consequence of these estimates we find that, for M large, the blow-up set concentrates near the points where [phi]p-1V attains its maximum.

  18. Effect of blow parameters in the jet penetration by physical model of BOF converter

    Directory of Open Access Journals (Sweden)

    Breno Totti Maia

    2014-07-01

    Full Text Available It is important to know about the bath behavior to reduce the blow time and splashing in top of the converter. The target of this work is to compare works on the effect of twisted nozzle, flow and lance height in the jet penetration by visual inspection and by energy balance that consider number of nozzles, vertical and twist angles. In the present work, lances with twisted nozzle angles, normal lances and special nozzle shape were used to describe the effects of jet on bath. Jet penetration and level of splashing were also available. For the four nozzles, the best result to reduce spitting was obtained at the twist angle, hard blow and high flow. High flow, reduction in bath lance distance and lower nozzle angle promoted a higher penetration, but with bad results for the process. The energy balance showed to be a proper tool to promote adjustments in process.

  19. Effect of jenny milk addition on the inhibition of late blowing in semihard cheese.

    Science.gov (United States)

    Cosentino, C; Paolino, R; Valentini, V; Musto, M; Ricciardi, A; Adduci, F; D'Adamo, C; Pecora, G; Freschi, P

    2015-08-01

    The occurrence of late blowing defects in cheese produces negative effects on the quality and commercial value of the product. In this work, we verified whether the addition of raw jenny milk to bulk cow milk reduced the late blowing defects in semihard cheeses. During cheesemaking, different aliquots of jenny milk were poured into 2 groups of 4 vats, each containing a fixed amount of cow milk. A group of cheeses was created by deliberately contaminating the 4 vats with approximately 3 log10 cfu/mL milk of Clostridium tyrobutyricum CLST01. The other 4 vats, which were not contaminated, were used for a second group of cheeses. After 120 d of ripening, some physical, chemical, and microbiological parameters were evaluated on the obtained semihard cheeses. Differences in sensory properties among cheeses belonging to the uncontaminated group were evaluated by 80 regular consumers of cheese. Our results showed that the increasing addition of jenny milk to cow milk led to a reduction of pH and total bacterial count in both cheese groups, as well as C. tyrobutyricum spores that either grew naturally or artificially inoculated. We observed a progressive reduction of the occurrence of late blowing defects in cheese as consequence of the increasing addition of jenny milk during cheese making. Moreover, the addition of jenny milk did not affect the acceptability of the product, as consumers found no difference among cheeses concerning sensorial aspects. In conclusion, the important antimicrobial activity of lysozyme contained in jenny milk has been confirmed in the current research. It is recommend for use as a possible and viable alternative to egg lysozyme for controlling late blowing defects in cheese.

  20. Asymptotic stability and blow up for a semilinear damped wave equation with dynamic boundary conditions

    KAUST Repository

    Gerbi, Stéphane

    2011-12-01

    In this paper we consider a multi-dimensional wave equation with dynamic boundary conditions, related to the KelvinVoigt damping. Global existence and asymptotic stability of solutions starting in a stable set are proved. Blow up for solutions of the problem with linear dynamic boundary conditions with initial data in the unstable set is also obtained. © 2011 Elsevier Ltd. All rights reserved.

  1. Checklist and distribution maps of the blow flies of Venezuela (Diptera, Calliphoridae, Mesembrinellidae).

    Science.gov (United States)

    Velásquez, Yelitza; Martínez-Sánchez, Ana Isabel; Thomas, Arianna; Rojo, Santos

    2017-01-01

    A checklist of the 39 species of blow flies (Calliphoridae and Mesembrinellidae) so far known to occur in Venezuela is provided, based on a thorough literature review and the examination of ca. 500 specimens deposited in the main entomological collections of the country. Data from the literature and museum collections were used to generate distribution maps for 37 species. Three species are recorded from Venezuela for the first time: Chrysomya putoria (Wiedemann, 1830), Mesembrinella spicata Aldrich, 1925 and Mesembrinella umbrosa Aldrich, 1922.

  2. Analysis of single blow effectiveness in non-uniform parallel plate regenerators

    DEFF Research Database (Denmark)

    Jensen, Jesper Buch; Bahl, Christian Robert Haffenden; Engelbrecht, Kurt;

    2011-01-01

    Non-uniform distributions of plate spacings in parallel plate regenerators have been found to induce loss of performance. In this paper, it has been investigated how variations of three geometric parameters (the aspect ratio, the porosity, and the standard deviation of the plate spacing) affects...... this loss in a single blow model of a parallel-plate regenerator. Simple analytical functions for the magnitude and the time scale of the reduction of performance are presented and compared to numerical results....

  3. Blow up for a 2x2 strictly hyperbolic system arising from chemical engineering

    CERN Document Server

    Bourdarias, Christian; Junca, Stéphane

    2009-01-01

    We consider a 2x2 hyperbolic system of conservation laws modeling heat less adsorption of a gaseous mixture with two species and infinite exchange kinetics, close to the system of Chromatography. In this model the velocity is not constant because the sorption effect is taken in account. Our aim is to construct a solution with a velocity which blows up at the characteristic boundary. This phenomenon only occurs in particular but physically relevant cases.

  4. The Blow-Up Rate for Strongly Perturbed Semilinear Wave Equations in the Conformal Case

    Energy Technology Data Exchange (ETDEWEB)

    Hamza, M. A., E-mail: ma.hamza@fst.rnu.tn; Saidi, O., E-mail: saidi.omar@hotmail.fr [Université de Tunis El Manar, Faculté des Sciences de Tunis, LR03ES04 Èquations aux dérivées partielles et applications (Tunisia)

    2015-12-15

    We consider in this work some class of strongly perturbed for the semilinear wave equation with conformal power nonlinearity. We obtain an optimal estimate for a radial blow-up solution and we have also obtained two less stronger estimates. These results are achieved in three-steps argument by the construction of a Lyapunov functional in similarity variables and the Pohozaev identity derived by multiplying (1.14) by y∂{sub y}w.

  5. BLOW-UP ESTIMATES FOR A NON-NEWTONIAN FILTRATION SYSTEM

    Institute of Scientific and Technical Information of China (English)

    杨作东; 陆启韶

    2001-01-01

    The prior estimate and decay property of positive solutions are derived for a system of quasi-linear elliptic differential equations first. Hence, the result of non-existence for differential equation system of radially nonincreasing positive solutions is implied. By using this non-existence result, blow-up estimates for a class quasi-linear reaction-diffusion systems (non-Newtonian filtration systems ) are established, which extends the result of semi- linear reaction- diffusion ( Fujita type ) systems .

  6. 赋值环的爆发%Blowing-ups of valuation rings

    Institute of Scientific and Technical Information of China (English)

    许宁

    2008-01-01

    From the infinite sequences of blowing-ups we get two valuation rings in cases of both discrete and nondiscrete in exercise 4.12 of Hartshorne's Algebraic Geometry.%针对Hartshorne的Algebraic Geometry一书第4章习题12,通过爆发的无穷序列得到了离散和非离散2个赋值环,并具体给出了爆发的过程.

  7. Hypersonic Boundary Layer Measurements with Variable Blowing Rates Using Molecular Tagging Velocimetry

    Science.gov (United States)

    Bathel, Brett F.; Danehy, Paul M.; Johansen, Craig T.; Jones, Stephen B.; Goyne, Christopher P.

    2012-01-01

    Measurements of mean and instantaneous streamwise velocity profiles in a hypersonic boundary layer with variable rates of mass injection (blowing) of nitrogen dioxide (NO2) were obtained over a 10-degree half-angle wedge model. The NO2 was seeded into the flow from a slot located 29.4 mm downstream of the sharp leading edge. The top surface of the wedge was oriented at a 20 degree angle in the Mach 10 flow, yielding an edge Mach number of approximately 4.2. The streamwise velocity profiles and streamwise fluctuating velocity component profiles were obtained using a three-laser NO2->NO photolysis molecular tagging velocimetry method. Observed trends in the mean streamwise velocity profiles and profiles of the fluctuating component of streamwise velocity as functions of the blowing rate are described. An effort is made to distinguish between the effect of blowing rate and wall temperature on the measured profiles. An analysis of the mean velocity profiles for a constant blowing rate is presented to determine the uncertainty in the measurement for different probe laser delay settings. Measurements of streamwise velocity were made to within approximately 120 gm of the model surface. The streamwise spatial resolution in this experiment ranged from 0.6 mm to 2.6 mm. An improvement in the spatial precision of the measurement technique has been made, with spatial uncertainties reduced by about a factor of 2 compared to previous measurements. For the quiescent flow calibration measurements presented, uncertainties as low as 2 m/s are obtained at 95% confidence for long delay times (25 gs). For the velocity measurements obtained with the wind tunnel operating, average single-shot uncertainties of less than 44 m/s are obtained at 95% confidence with a probe laser delay setting of 1 gs. The measurements were performed in the 31-inch Mach 10 Air Tunnel at the NASA Langley Research Center.

  8. Behavior of slag foaming caused by blowing gas in molten slags

    Energy Technology Data Exchange (ETDEWEB)

    Wu, K.

    2000-10-01

    The relationship between the height of foaming slag and blowing gas flow rate has been investigated at different temperature and with additives such as coal, coke, graphite and CaO, in order to understand the foaming phenomenon in most metallurgical processes comprehensively. On the basis of experimental results, the regressed foam behavior equations ({delta}=b(center dot)V{sup m}) were obtained. Those correlation coefficients were in range from 0.995 to 0.999. It means that the foam behavior equation can be used to describe foaming ability of the slag foaming caused by blowing gas quantitatively. The foaming index {sigma} is only a limited case for of the foam behavior equation and can be used only at high temperature and without additives for the foaming phenomenon caused by blowing gas. It was found also that the large carbonaceous particles could decrease the height of foaming slag, however the fine carbonaceous and CaO powder could increase it. The basicity of the slag affects the height of foaming slag. (author)

  9. Equilibrium turbulent boundary layers with wall suction/blowing and pressure gradients

    Science.gov (United States)

    Patwardhan, Saurabh; Ramesh, O. N.

    2012-11-01

    Conditions for the equilibrium conditions in turbulent boundary layers with suction or blowing across a no slip wall and pressure gradients are derived from the governing equations. It is also shown that under these conditions the governing equations show self similarity in the conventional inner co-ordinates as well as ``laminar-like'' co-ordinates. The only turbulent boundary layer in ``perfect equilibrium'' known as sink flow turbulent boundary layer forms a subset of this more general equilibrium concept. Direct numerical simulations were carried out to investigate this hypothesis for the case of favourable pressure gradient with small blowing at the wall. Reynolds number invariance and complete self similarity of mean velocity profile and second order turbulence statistics is observed along the flow direction similar to the sink flow boundary layer. A comparison between the case with wall blowing and imposed favourable pressure gradient and the sink flow case for same value of pressure gradient parameter reveals a shift in log law in mean velocity profile and increase in peak turbulence intensities.

  10. Blowing snow at D17, Adélie Land, Antarctica: atmospheric moisture issues

    Directory of Open Access Journals (Sweden)

    H. Barral

    2014-06-01

    Full Text Available Three years of blowing snow and meteorological observations have been collected along a 7 m mast at site D17 in coastal Adélie Land, Antarctica. This is a region particularly exposed to katabatic winds. The atmospheric surface layer is often close to saturation because of the sublimation of the airborne snow particles. A systematic dry bias results in atmospheric models that ignore blowing snow and its moistening effects, and in meteorological analyses that use such model. The Crocus snow-pack model, including a parameterization for the erosion of surface snow by wind, reproduces the observed march of snow accumulation and ablation if the observed meteorology is used as input. Because of subsaturation, a 2.5 fold increase in surface sublimation is obtained if analyzed surface air meteorology is used. The sublimation obtained in the Crocus model poorly agrees with the moisture fluxes evaluated using the profile method along the mast. Moisture gradients are very weak, particularly when blowing snow saturates the air, to a point where measurement accuracy is an issue. Using the profile method, the measurement uncertainties are strongly amplified in case of strong wind. In such conditions, a single level bulk parameterization with surface energy balance closure as in the Crocus model is preferred. At D17, more than half of the total snow fall is removed by erosion and sublimation, both at the surface and, mainly, of airborne snow particles.

  11. Controlled longitudinal emittance blow-up using band-limited phase noise in CERN PSB

    Science.gov (United States)

    Quartullo, D.; Shaposhnikova, E.; Timko, H.

    2017-07-01

    Controlled longitudinal emittance blow-up (from 1 eVs to 1.4 eVs) for LHC beams in the CERN PS Booster is currently achievied using sinusoidal phase modulation of a dedicated high-harmonic RF system. In 2021, after the LHC injectors upgrade, 3 eVs should be extracted to the PS. Even if the current method may satisfy the new requirements, it relies on low-power level RF improvements. In this paper another method of blow-up was considered, that is the injection of band-limited phase noise in the main RF system (h=1), never tried in PSB but already used in CERN SPS and LHC, under different conditions (longer cycles). This technique, which lowers the peak line density and therefore the impact of intensity effects in the PSB and the PS, can also be complementary to the present method. The longitudinal space charge, dominant in the PSB, causes significant synchrotron frequency shifts with intensity, and its effect should be taken into account. Another complication arises from the interaction of the phase loop with the injected noise, since both act on the RF phase. All these elements were studied in simulations of the PSB cycle with the BLonD code, and the required blow-up was achieved.

  12. MHD Boundary Layer Flow of Dilatant Fluid in a Divergent Channel with Suction or Blowing

    Institute of Scientific and Technical Information of China (English)

    Krishnendu Bhattacharyya; G.C.Layek

    2011-01-01

    @@ An analysis is carried out to study a steady magnetohydrodynamic(MHD) boundary layer How of an electrically conducting incompressible power-law non-Newtonian fluid through a divergent channel.The channel walls are porous and subjected to either suction or blowing of equal magnitude of the same kind of fluid on both walls.The fluid is permeated by a magnetic field produced by electric current along the line of intersection of the channel walls.The governing partial differential equation is transformed into a self-similar nonlinear ordinary differential equation using similarity transformations.The possibility of boundary layer flow in a divergent channel is analyzed with the power-law fluid model.The analysis reveals that the boundary layer flow (without separation) is possible for the case of the dilatant fluid model subjected to suitable suction velocity applied through its porous walls,even in the absence of a magnetic field.Further, it is found that the boundary layer flow is possible even in the presence of blowing for a suitable value of the magnetic parameter.It is found that the velocity increases with increasing values of the power-law index for the case of dilatant fluid.The effects of suction/blowing and magnetic field on the velocity are shown graphically and discussed physical尔

  13. BLOW-UP SOLUTIONS FOR A CLASS OF NONLINEAR PARABOLIC EQUATIONS WITH MIXED BOUNDARY CONDITIONS

    Institute of Scientific and Technical Information of China (English)

    DING Juntang; LI Shengjia

    2005-01-01

    The type of problem under consideration is{ut = (△)(a(u)b(x)(△)u) + g(x,q,t)f(u)in D(0,T),u=0onГ1×(0,T), (e)u/(e)u+ +σ(x,t)u = 0 on Г2×(0,T),Г1∪Г2=(e)D, u(x,0) = uo(x) ≥ 0,(≠) 0 in( ̄D),where D is a smooth bounded domain of RN,q=|(△)u|2.By constructing an auxiliary function and using Hopf's maximum principles on it,existence theorems of blow-up solutions,upper bound of “blow-up time” and upper estimates of “blow-up rate” axe given under suitable assumptions on a,b,f,g,σ and initial date uo(x).The obtained results are applied to some examples in which a,b,f,g and σ are power functions or exponential functions.

  14. Lightweight Medium-Sized Parts Made of Foamed HDPE Processed via Extrusion Blow Moulding: Analysis of Parison Formation

    Directory of Open Access Journals (Sweden)

    Victor Peinado

    2015-02-01

    Full Text Available The manufacturing of medium-sized hollow parts using a foamed high density polyethylene was studied using a conventional accumulator blow extrusion machine and a systematic capture of pictures during the parison formation. To fully monitor the parison formation, several experiments were carried out varying the chemical foaming agent content from 0 wt.% to 2 wt.% and increasing the push extrusion speed. Results pointed out greater wall thickness, diameter, and length of parisons with higher weight percentage of blowing agent and extrusion speed. A full experimental characterisation of parison dimensions was essential to assure a proper prediction of the blowing step. Information was used as input for modelling and simulations of the blowing phase of an industrial container. To validate the proposed methodology, a blow moulding process of a generic container was simulated using Ansys Polyflow v13 software and its finite element analysis which provided an accurate approximation of the wall thickness expected. Further real tests on the simulated container also demonstrated that, in those parisons with a 1 wt.% CFA concentration and higher blowing pressure, there was remarkable improvement on their packaging properties such as decreasing of the total weight of the container and an enhancement of its surface quality.

  15. Students' attitudes and potential behaviour with regard to whistle blowing as they pass through a modern medical curriculum.

    Science.gov (United States)

    Goldie, John; Schwartz, Lisa; McConnachie, Alex; Morrison, Jillian

    2003-04-01

    To examine students' attitudes and potential behaviour with regard to whistle blowing as they progress through a modern undergraduate medical curriculum. Cohort design. University of Glasgow Medical School. A cohort of students entering Glasgow University's new learner-centred, integrated medical curriculum in October 1996. Students' pre- and post-Year 1, post-Year 3 and post-Year 5 responses to the whistle blowing vignette of the Ethics in Health Care Instrument (EHCI) were examined quantitatively and qualitatively. Analysis of students' multichoice answers enabled measurement of movement towards professional consensus opinion. Analysis of written justifications helped determine whether their reasoning was consistent with professional consensus and enabled measurement of change in knowledge content and recognition of the values inherent in the vignette. Themes in students' reasoning behind their decisions of whether or not to whistle blow were also identified. There was little improvement in students' performance as they progressed through the curriculum in terms of their proposed behaviour on meeting the whistle blowing scenario. There was also no improvement in the quality of justifications provided. Students' reasoning on whether or not to whistle blow was found to change as the curriculum progressed. The EHCI has the potential to elicit students' attitudes towards ethical issues at entry to medical school and to measure change as they progress through the curriculum. Students should be encouraged to contemplate dilemmas from all ethical standpoints and consider relevant legal implications. Whistle blowing should be addressed as part of the wider domain of professionalism.

  16. A Proof of Concept Experiment for Reducing Skin Friction by Using a Micro-Blowing Technique

    Science.gov (United States)

    Hwang, Danny P.

    1996-01-01

    A proof of concept experiment for reducing skin friction has been conducted in the Advanced Nozzle and Engine Components Test Facility at the NASA Lewis Research Center. In this unique concept, called the micro-blowing technique (MBT), an extremely small amount of air was blown vertically through very small holes to reduce the surface roughness and to control the gradient of the flow velocity profile on the surface thereby reducing skin friction. Research revealed that the skin was the most important factor to make this concept achievable. The proposed skin consisted of two layers. The inner layer was a low permeable porous skin for distributing the blowing air evenly while the outer layer with small holes controlled the vertical or nearly vertical blowing air. Preliminary experimental results showed that the MBT has the potential of a very large reduction in skin friction below the skin friction of a nonporous plain flat plate. Of the skins tested, three have been identified as the MBT skins. They provided very low unblown skin friction such that a large skin friction reduction, below a flat plate value, was achieved with very small amounts of blowing air. The reduction in skin friction of 55 percent was achieved at the Mach number of 0.3 for the exhaust pressure of 0.85 atm, and 60 percent reduction was obtained for the exhaust pressure of 0.24 atm (corresponding to 10 700-m altitude) at the same Mach number. A significant reduction in skin friction of over 25 percent was achieved for the exhaust pressure of 0.24 atm at the Mach number of 0.7. This implied that the MBT could be applied to a wide range of flight conditions. It is also believed that additional 10 percent reduction could be obtained by eliminating the gap between the inner layer and the outer layer. The aspect ratio of the vertical small holes for the outer layer of the MBT skin should be larger than 4 based on the preliminary conclusion from this test. Many experiments are needed to find out the

  17. TESTING OF REFRIGERANT MIXTURES IN RESIDENTIAL HEAT PUMPS

    Science.gov (United States)

    The report gives results of an investigation of four possibilities for replacing Hydrochlorofluorocarbon-22 (HCFC-22) with the non-ozone-depleting new refrigerants R-407D and R-407C in residential heat pumps. The first and simplest scenario was a retrofit with no hardware modific...

  18. 75 FR 74773 - Mandatory Reporting of Greenhouse Gases: Additional Sources of Fluorinated GHGs

    Science.gov (United States)

    2010-12-01

    ... greenhouse gas GWP global warming potential HAP hazardous air pollutant(s) HCFC hydrochlorofluorocarbon HFC... dioxide equivalent MRR mandatory greenhouse gas reporting rule MS mass spectrometry MVAC motor vehicle air... Protection Agency 40 CFR Part 98 Mandatory Reporting of Greenhouse Gases: Additional Sources of...

  19. On blow-up "twistors" for the Navier--Stokes equations in $R^3$: a view from reaction-diffusion theory

    OpenAIRE

    Galaktionov, V. A.

    2009-01-01

    Various formal blow-up scenarious for the Navier--Stokes equaitons in 3D are discussed. A particular interest is payed to "twistor mechanisms" based on angular logarithmic blow-up travelling waves, and to a formation of "blow-up tornado" about the singular stationary Slezkin--Landau solutions (1934--44) of a submerged jet. A survey on various related aspects of singularity analysis for nonlinear parabolic PDEs is enclosed.

  20. Thermo-mechanical simulation of liquid-supported stretch blow molding

    Energy Technology Data Exchange (ETDEWEB)

    Zimmer, J.; Stommel, M. [Chair of Polymer Materials, Saarland University, Saarbruecken, Germany, – j.zimmer@mx.uni-saarland.de (Germany)

    2015-05-22

    Stretch blow molding is the well-established plastics forming method to produce Polyehtylene therephtalate (PET) bottles. An injection molded preform is heated up above the PET glass transition temperature (Tg∼85°C) and subsequently inflated by pressurized air into a closed cavity. In the follow-up filling process, the resulting bottle is filled with the final product. A recently developed modification of the process combines the blowing and filling stages by directly using the final liquid product to inflate the preform. In a previously published paper, a mechanical simulation and successful evaluation of this liquid-driven stretch blow molding process was presented. In this way, a realistic process parameter dependent simulation of the preform deformation throughout the forming process was enabled, whereas the preform temperature evolution during forming was neglected. However, the formability of the preform is highly reduced when the temperature sinks below Tg during forming. Experimental investigations show temperature-induced failure cases due to the fast heat transfer between hot preform and cold liquid. Therefore, in this paper, a process dependent simulation of the temperature evolution during processing to avoid preform failure is presented. For this purpose, the previously developed mechanical model is used to extract the time dependent thickness evolution. This information serves as input for the heat transfer simulation. The required material parameters are calibrated from preform cooling experiments recorded with an infrared-camera. Furthermore, the high deformation ratios during processing lead to strain induced crystallization. This exothermal reaction is included into the simulation by extracting data from preform measurements at different stages of deformation via Differential Scanning Calorimetry (DSC). Finally, the thermal simulation model is evaluated by free forming experiments, recorded by a high-speed infrared camera.

  1. Thermo-mechanical simulation of liquid-supported stretch blow molding

    Science.gov (United States)

    Zimmer, J.; Stommel, M.

    2015-05-01

    Stretch blow molding is the well-established plastics forming method to produce Polyehtylene therephtalate (PET) bottles. An injection molded preform is heated up above the PET glass transition temperature (Tg˜85°C) and subsequently inflated by pressurized air into a closed cavity. In the follow-up filling process, the resulting bottle is filled with the final product. A recently developed modification of the process combines the blowing and filling stages by directly using the final liquid product to inflate the preform. In a previously published paper, a mechanical simulation and successful evaluation of this liquid-driven stretch blow molding process was presented. In this way, a realistic process parameter dependent simulation of the preform deformation throughout the forming process was enabled, whereas the preform temperature evolution during forming was neglected. However, the formability of the preform is highly reduced when the temperature sinks below Tg during forming. Experimental investigations show temperature-induced failure cases due to the fast heat transfer between hot preform and cold liquid. Therefore, in this paper, a process dependent simulation of the temperature evolution during processing to avoid preform failure is presented. For this purpose, the previously developed mechanical model is used to extract the time dependent thickness evolution. This information serves as input for the heat transfer simulation. The required material parameters are calibrated from preform cooling experiments recorded with an infrared-camera. Furthermore, the high deformation ratios during processing lead to strain induced crystallization. This exothermal reaction is included into the simulation by extracting data from preform measurements at different stages of deformation via Differential Scanning Calorimetry (DSC). Finally, the thermal simulation model is evaluated by free forming experiments, recorded by a high-speed infrared camera.

  2. Numerical study of bituminous coal combustion in a boiler furnace with bottom blowing

    Science.gov (United States)

    Zroychikov, N. A.; Kaverin, A. A.

    2016-11-01

    Results obtained by the numerical study of a solid fuel combustion scheme with bottom blowing using Ekibastuz and Kuznetsk bituminous coals of different fractional makeup are presented. Furnace chambers with bottom blowing provide high-efficiency combustion of coarse-grain coals with low emissions of nitrogen oxides. Studying such a combustion scheme, identification of its technological capabilities, and its further improvement are topical issues. As the initial object of study, we selected P-57-R boiler plant designed for burning of Ekibastuz bituminous coal in a prismatic furnace with dry-ash (solid slag) removal. The proposed modernization of the furnace involves a staged air inflow under the staggered arrangement of directflow burners (angled down) and bottom blowing. The calculation results revealed the specific aerodynamics of the flue gases, the trajectories of solid particles in the furnace chamber, and the peculiarities of the fuel combustion depending on the grinding fineness. It is shown that, for coal grinding on the mill, the overall residue on the screen plate of 90 µm ( R 90 ≤ 27% for Ekibastuz coal and R 90 ≤ 15% for Kuznetsk coal) represents admissible values for fuel grind coarsening in terms of economic efficiency and functional reliability of a boiler. The increase in these values leads to the excess of regulatory heat losses and unburned combustible losses. It has been established that the change in the grade of the burned coal does not significantly affect the flow pattern of the flue gases, and the particles trajectory is essentially determined by the elemental composition of the fuel.

  3. Drag Force of Non-newtonian Fluid on a Continuous Moving Surface with Strong Suction/Blowing

    Institute of Scientific and Technical Information of China (English)

    郑连存; 张欣欣; 赫冀成

    2003-01-01

    A theoretical analysis for the laminar boundary layer flow of a non-Newtonian fluid on a continuous moving flat plate with surface strong suction/blowing is made. The types of potential flows necessary for similar solutions to the boundary layer are determined and both analytical and numerical solutions are presented. It is shown that the solution of the boundary layer problem depends not only on the ratio of the velocity of the plate to the velocity of the free stream, but also on the suction/blowing parameter. The skin friction decreases with increasing the parameters of power law and blowing. In the case of existing suction, the shear force decreases with the increases of tangential velocity, the largest shear force occurs at wall and the smallest shear force occurs at the edge of the boundary layer. However, in the case of existing surface blowing, the shear force initially increases with tangentialvelocity and the biggest shear force occurs at the interior of the boundary layer, the skin friction approaches to zero as the blowing rate approaches the critical value.

  4. Structural and Morphological Characterization of Micro and Nanofibers Produced by Electrospinning and Solution Blow Spinning: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Juliano E. Oliveira

    2013-01-01

    Full Text Available Nonwoven mats of poly(lactic acid (PLA, poly(ethylene oxide (PEO, and poly(ε-caprolactone (PCL were prepared at a nano- and submicron scale by solution blow spinning (SBS and electrospinning in order to compare crystalline structure and morphology developed by both processes during fiber formation. Polymer solutions were characterized by rheometry and tensiometry. Spun fibers were characterized by several analytical steps. SEM analyses showed that both solution blow spun and electrospun fibers had similar morphology. Absence of residual solvents and characteristic infrared bands in the solution blow spun fibers for PLA, PCL, and PEO was confirmed by FTIR studies. XRD diffraction patterns for solution blow spun and electrospun mats revealed some differences related to distinct mechanisms of fiber formation developed by each process. Significant differences in thermal behavior by DSC were observed between cast films of PLA, PCL, and PEO and their corresponding spun nanofibers. Furthermore, the average contact angles for spun PLA and PCL were higher than for electrospun mats, whereas it was slightly lower for PEO. When comparing electrospun and solution blow spun fibers, it was possible to verify that fiber morphology and physical properties depended both on the spinning technique and type of polymer.

  5. Critical Blow-Up and Global Existence for Discrete Nonlinear p-Laplacian Parabolic Equations

    Directory of Open Access Journals (Sweden)

    Soon-Yeong Chung

    2014-01-01

    Full Text Available The goal of this paper is to investigate the blow-up and the global existence of the solutions to the discrete p-Laplacian parabolic equation utx,t=Δp,wux,t+λux,tp-2ux,t, x,t∈S×0,∞, ux,t=0, x,t∈∂S×0,∞, ux,0=u0, depending on the parameters p>1 and λ>0. Besides, we provide several types of the comparison principles to this equation, which play a key role in the proof of the main theorems. In addition, we finally give some numerical examples which exploit the main results.

  6. Blow-Up Criterion of Weak Solutions for the 3D Boussinesq Equations

    Directory of Open Access Journals (Sweden)

    Zhaohui Dai

    2015-01-01

    Full Text Available The Boussinesq equations describe the three-dimensional incompressible fluid moving under the gravity and the earth rotation which come from atmospheric or oceanographic turbulence where rotation and stratification play an important role. In this paper, we investigate the Cauchy problem of the three-dimensional incompressible Boussinesq equations. By commutator estimate, some interpolation inequality, and embedding theorem, we establish a blow-up criterion of weak solutions in terms of the pressure p in the homogeneous Besov space Ḃ∞,∞0.

  7. Potential of anticlostridial Lactobacillus isolated from cheese to prevent blowing defects in semihard cheese

    DEFF Research Database (Denmark)

    Christiansen, Pia; Vogensen,, F. K.; Nielsen, E. W;

    2010-01-01

    Five anticlostridial Lactobacillus strains isolated from cheese were selected for a mixed adjunct culture. Cheese with the mixed adjunct culture (experimental) and without (control) was made in triplicate and ripened as vacuum-packed and surface-ripened cheese. Cheese gross composition was similar...... in the experimental cheeses. Anticlostridial nonstarter Lactobacillus strains have potential as protective adjunct cultures against blowing defects in cheese........ Excessive gas formation occurred only in control cheeses. In contrast to control cheeses, the experimental cheeses were dominated by the added adjunct Lactobacillus strains (repetitive-PCR). Casein breakdown was not influenced, however, the total amount of amino acids and pH was slightly lower...

  8. Checklist and distribution maps of the blow flies of Venezuela (Diptera, Calliphoridae, Mesembrinellidae)

    Science.gov (United States)

    Velásquez, Yelitza; Martínez-Sánchez, Ana Isabel; Thomas, Arianna; Rojo, Santos

    2017-01-01

    Abstract A checklist of the 39 species of blow flies (Calliphoridae and Mesembrinellidae) so far known to occur in Venezuela is provided, based on a thorough literature review and the examination of ca. 500 specimens deposited in the main entomological collections of the country. Data from the literature and museum collections were used to generate distribution maps for 37 species. Three species are recorded from Venezuela for the first time: Chrysomya putoria (Wiedemann, 1830), Mesembrinella spicata Aldrich, 1925 and Mesembrinella umbrosa Aldrich, 1922. PMID:28228670

  9. On the Blow-up Criterion of Smooth Solutions to the MHD System in BMO Space

    Institute of Scientific and Technical Information of China (English)

    Bao-quan Yuan

    2006-01-01

    In this paper we study the blow-up criterion of smooth solutions to the incompressible magnetohydrodynamics system in BMO space. Let (u(x,t),b(x,t)) be smooth solutions in (0, T). It is shown that the solution (u(x, t), b(x, t)) can be extended beyond t = T if (u(x, t), b(x, t)) ∈ L1(0, T; BMO) or the vorticity(rot u(x, t), rot b(x, t)) ∈ L1 (0, T; BMO) or the deformation (Def u(x, t), Def b(x, t)) ∈ L1 (0, T; BMO).

  10. Regular solutions for multiplicative stochastic Landau-Lifshitz-Gilbert equation and blow-up phenomena

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The two-dimensional Landau-Lifshitz-Gilbert equation of motion for a classical magnetic moment perturbed by a multiplicative noise is considered. This equation is highly nonlinear in nature and, for this reason, many mathematical results in stochastic partial differential equations (SPDEs) cannot be applied. The aim of this work is to introduce the difference method to handle SPDEs and prove the existence of regular martingale solutions in dimension two. Some blow-up phenomena are presented, which are drastically different from the deterministic case. Finally, to yield correct thermal-equilibrium properties, Stratonovitch integral is used instead of It?o integral.

  11. THE EFFECT OF BLOWING AGENTS ON THE EFFECTIVENESS OF POLY(VINYL CHLORIDE EXTRUSION

    Directory of Open Access Journals (Sweden)

    Tomasz Garbacz

    2016-12-01

    Full Text Available The cellular extrusion is a method for manufacturing profiles, bars, low density cellu-lar coatings and other cellular products that have no hollow cavities on the surface and show minimal processing shrinkage, while their properties are similar to those of products produced by conventional extrusion. The paper deals with cellular extrusion of PVC. The investigation of the process was conducted using state-of-the-art endothermic and exothermic blowing agents that were dosed in up to 1.5% by weight. The experiments involved measuring output, energy consumption and energy efficiency of the process.

  12. The transpired turbulent boundary layer in various pressure gradients and the blow-off condition

    Science.gov (United States)

    Georgiou, D. P.; Louis, J. F.

    1984-12-01

    Experimental data are reported from studies of the cooling effectiveness and conditions leading to blow-off in transpiration cooling (TC). The TC configuration used featured a sintered bronze plate in a hot blowdown wind tunnel. Cooled air was pumped through the plate and data were gathered with calorimeters downstream of a piece of sandpaper which tripped the boundary layer. Pressure taps were also used. Local pressure gradient effects were small, but local accelerations reduced the cooling effectiveness. The downstream Stanton numbers were sensitive to the upstream coolant-injection ratio. Increasing the injection rate had, at best, only a small effect on the local heat flux.

  13. A rare case of 'blow-up' fracture of the orbit in a child

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Preena N.; Kenney, Ian J. [Royal Alexandra Hospital for Sick Children, Radiology Department, Brighton (United Kingdom)

    2009-08-15

    We present a case of blow-out fracture of the superomedial orbital wall in a 6-year-old boy. The initial plain radiograph showed an intact orbital margin and opacification of the ethmoid sinus. A fine-cut CT scan of the facial bones revealed a complex fracture of the medial orbital wall extending into the orbital roof, with migration of fracture fragments into the anterior cranial fossa. Suspicion for unusual orbital fractures is crucial when assessing a child for orbital trauma, especially when plain radiographs do not display the typical signs. (orig.)

  14. Blowing bubbles

    Energy Technology Data Exchange (ETDEWEB)

    Casteel, K.

    1999-04-01

    The article, based on a series of interviews with column flotation equipment suppliers, reviews and comments on the progress of bubble generator design. Developments mentioned include the Air/Water sparger from Cominco, the SparJet and SlamJet from CPT, the CISA sparger from Sevala CISA, Microcel flotation columns from Birtley Engineering, Flotaire column flotation cells from LMC International, and the Variable Gap Sparger from MinnovEX. 1 fig., 2 photo.

  15. Aerodynamic drag reduction of a simplified squareback vehicle using steady blowing

    Science.gov (United States)

    Littlewood, R. P.; Passmore, M. A.

    2012-08-01

    A large contribution to the aerodynamic drag of a vehicle arises from the failure to fully recover pressure in the wake region, especially on squareback configurations. A degree of base pressure recovery can be achieved through careful shape optimisation, but the freedom of an automotive aerodynamicist to implement significant shape changes is limited by a variety of additional factors such styling, ergonomics and loading capacity. Active flow control technologies present the potential to create flow field modifications without the need for external shape changes and have received much attention in previous years within the aeronautical industry and, more recently, within the automotive industry. In this work the influence of steady blowing applied at a variety of angles on the roof trailing edge of a simplified ¼ scale squareback style vehicle has been investigated. Hot-wire anemometry, force balance measurements, surface pressure measurements and PIV have been used to investigate the effects of the steady blowing on the vehicle wake structures and the resulting body forces. The energy consumption of the steady jet is calculated and is used to deduce an aerodynamic drag power change. Results show that overall gains can be achieved; however, the large mass flow rate required restricts the applicability of the technique to road vehicles. Means by which the mass flow rate requirements of the jet may be reduced are discussed and suggestions for further work put forward.

  16. New Design of Crypto-Based Pseudo random number generator (CBPRNG using BLOW FISH cipher

    Directory of Open Access Journals (Sweden)

    T.Chalama Reddy

    2013-06-01

    Full Text Available Random Number Generators (RNGs are an important building block for algorithms and protocols in cryptography. Random number generation is used in a wide variety of cryptographic operations, such as key generation and challenge/response protocols. A random number generator outputs a sequence of 0s and 1s such that at any position, the next bit cannot be expected on the previous bits. However, true random number produces non- deterministic output since if the same random generator is run twice, identical results are not received. Thus we go for pseudo random number generator that is deterministic device because if this random number generator is run twice or more, it gives same results. Our paper presents new crypto based pseudorandom number generator. It uses BLOW FISH ciphers and the Cipher-Block chaining (CBC mode that uses three stages of the block chaining. The plain text for each stage comes from the output of the first BLOW FISH, which uses the 64-Bit date and time as the plain text. CBPRNG creates three 64-bit random numbers, the first and the second are concatenated to create a 128-random number and the third is used as next initial vector (IV for CBPRNG. Our Crypto-Based Pseudo-random Number Generator produces a sequence of bits that has arandom looking distribution. This new generator helps to develop huge range cryptographic applications to increase the system security. A number of applications such as financial security applications and Pretty Good Privacy (PGP use this technique.

  17. Blow-up criterion for 2-D Boussinesq equations in bounded domain

    Institute of Scientific and Technical Information of China (English)

    HU Langhua; JIAN Huaiyu

    2007-01-01

    We extend the results for 2-D Boussinesq equations from R2 to a bounded domain Ω.First, as for the existence of weak solutions, we trans form Boussinesq equations to a nonlinear evolution equation Ut + A(t, U) = O.In stead of using the methods of fundamental solutions in the case of entire R2, we study the qualities of F(u,v) = (u.▽)v to get some useful estimates for A(t, U), which helps us to conclude the local-in-time existence and uniqueness of solutions.Second, as for blow-up criterions, we use energy methods, Sobolev inequalities and Gronwall inequality to con trol‖θ‖Hs(Ω) and ‖u‖H8(Ω) by ‖▽θ‖L∞(Ω) and‖▽u‖L∞(Ω).Furthermore,‖▽θ‖L∞(Ω) can control ‖▽u‖L∞(Ω) by using vorticity transportation equations.At last, ‖▽θ‖Mφ(Ω) can control ‖▽θ‖L∞(Ω).Thus, we can find a blow up criterion in the form of limt→T* ∫to‖▽θ(.,τ)‖Mφ(Ω)dτ= ∞.

  18. Probing the Blow-Off Criteria of Hydrogen-Rich "Super-Earths"

    CERN Document Server

    Lammer, H; Odert, P; Kislyakova, K G; Leitzinger, M; Khodachenko, M L

    2012-01-01

    The discovery of transiting "super-Earths" with inflated radii and known masses such as Kepler-11b-f, GJ 1214b and 55 Cnc e, indicates that these exoplanets did not lose their nebula-captured, degassed or impact-delivered hydrogen-rich protoatmospheres by atmospheric escape processes. Because hydrodynamic blow-off of atmospheric hydrogen atoms is the most efficient atmospheric escape process we apply a time-dependent numerical algorithm which is able to solve the system of 1-D fluid equations for mass, momentum, and energy conservation to investigate the criteria under which hydrogen-rich "super-Earths" can experience hydrodynamic expansion by heating of the stellar XUV (soft X-rays and extreme ultraviolet) radiation and thermal escape via blow-off. Depending on orbit location, XUV flux, heating efficiency and the planet's mean density our results indicate that the upper atmospheres of all "super-Earths" can expand to large distances, so that besides of Kepler-11c all of them experience atmospheric mass-loss ...

  19. Sea salt aerosol from blowing snow on sea ice - modeling vs observation

    Science.gov (United States)

    Yang, Xin; Frey, Markus; Norris, Sarah; Brooks, Ian; Anderson, Philip; Jones, Anna; wolff, Eric; Legrand, Michel

    2016-04-01

    Blowing snow over sea ice, through a subsequent sublimation process of salt-containing blown snow particles, has been hypothesized as a significant sea salt aerosol (SSA) source in high latitudes. This mechanism has been strongly supported by a winter cruise in the Weddell Sea (during June-August 2013). The newly collected data, including both physical and chemical components, provide a unique way to test and validate the parameterisation used for describing the SSA production from blowing snow events. With updates to some key parameters such as snow salinity in a global Chemistry-transport model pTOMCAT, simulated SSA concentrations can be well compared with measured SSA data. In this presentation, I will report modeled SSA number density against collected data on board of Polarstern ship during the Weddell Sea cruise, as well as modeled SSA massive concentrations against those measured at both coastal sites such as Alert in the North and Dumont d'Urville (DDU) in the South and central Antarctic sites such as Concordia and Kohnen stations. Model experiments indicated that open ocean-sourced SSA could not explain the observed winter SSA peaks seen in most polar sites, while with sea ice-sourced SSA in the model, the winter peaks can be well improved indicating the importance of sea ice-sourced SSA as a significant contributor to the salts (Na+, Cl-) recorded in the ice core.

  20. Aerodynamic drag reduction of a simplified squareback vehicle using steady blowing

    Energy Technology Data Exchange (ETDEWEB)

    Littlewood, R.P. [LaVisionUK Ltd, Grove, Oxon (United Kingdom); Passmore, M.A. [Loughborough University, Department of Aeronautical and Automotive Engineering, Loughborough (United Kingdom)

    2012-08-15

    A large contribution to the aerodynamic drag of a vehicle arises from the failure to fully recover pressure in the wake region, especially on squareback configurations. A degree of base pressure recovery can be achieved through careful shape optimisation, but the freedom of an automotive aerodynamicist to implement significant shape changes is limited by a variety of additional factors such styling, ergonomics and loading capacity. Active flow control technologies present the potential to create flow field modifications without the need for external shape changes and have received much attention in previous years within the aeronautical industry and, more recently, within the automotive industry. In this work the influence of steady blowing applied at a variety of angles on the roof trailing edge of a simplified 1/4 scale squareback style vehicle has been investigated. Hot-wire anemometry, force balance measurements, surface pressure measurements and PIV have been used to investigate the effects of the steady blowing on the vehicle wake structures and the resulting body forces. The energy consumption of the steady jet is calculated and is used to deduce an aerodynamic drag power change. Results show that overall gains can be achieved; however, the large mass flow rate required restricts the applicability of the technique to road vehicles. Means by which the mass flow rate requirements of the jet may be reduced are discussed and suggestions for further work put forward. (orig.)

  1. Chemotaxonomic Profile and Intraspecific Variation in the Blow Fly of Forensic Interest Chrysomya megacephala (Diptera: Calliphoridae).

    Science.gov (United States)

    Paula, Michele C; Antonialli-Junior, William F; Mendonça, Angélica; Michelutti, Kamylla B; Eulalio, Aylson D M M; Cardoso, Claudia A L; de Lima, Thiago; Von Zuben, Cláudio J

    2017-01-01

    Necrophagous insects such as blow flies (Diptera: Calliphoridae) are considered crucial in forensic entomology. Identification at species level and determination of larval stage are the basis for estimation of postmortem interval (PMI). Insect evidence can also be used in the determination of crime scenes, since body displacement is common. The aim of this study was to determine the chemotaxonomic profile and intraspecific variability of the forensically important blow fly Chrysomya megacephala (F. 1794). Adults were collected in the municipalities of Dourados-MS (Brazil) and Rio Claro-SP (Brazil), and then transferred to the laboratory for oviposition and development of the immature stages. Chemical analysis of cuticular compounds was performed by gas chromatography. Cuticular chemical profiles varied significantly between the two populations, as well as between developmental stages, supporting the use of these compounds as a complementary tool to help identify the species and its stages, along with geographical variability. This could greatly accelerate forensic investigations, eliminating the need to allow the fly larvae to develop until adult stage in order to confirm the species identity and sample origin.

  2. Study of Mass Transfer in Gas Blowing Processes for Silicon Purification

    Science.gov (United States)

    Altenberend, Jochen; Chichignoud, Guy; Delannoy, Yves

    2017-03-01

    Boron removal processes are crucial to make the metallurgical route for silicon refining for solar cells competitive and thus reduce the cost of solar energy. The rate-limiting step was investigated in silicon purification processes for boron removal based on gas blowing, to gain better understanding that should help to improve the design of such processes. We calculate the boron concentration in the off-gas that corresponds to chemical equilibrium between the gas and silicon. The real concentration in the off-gas ranges between 9 and 30 pct of this theoretical value calculated using Gibbs free energies reported in literature. Purification experiments with varying temperature and hydrogen concentration were done to evaluate whether limited chemical reaction rates induce deviation from chemical equilibrium. The experiments and data from literature show that the chemical reactions at the surface of the melt are close to chemical equilibrium, thus the purification rate is limited by mass transfer in the gas phase near the interface. Based on this, recommendations for the design of a gas blowing purification process are given.

  3. Aluminum integral foams with tailored density profile by adapted blowing agents

    Science.gov (United States)

    Hartmann, Johannes; Fiegl, Tobias; Körner, Carolin

    2014-05-01

    The goal of the present work is the variation of the structure of aluminum integral foams regarding the thickness of the integral solid skin as well as the density profile. A modified die casting process, namely integral foam molding, is used in which an aluminum melt and blowing agent particles (magnesium hydride MgH2) are injected in a permanent steel mold. The high solidification rates at the cooled walls of the mold lead to the formation of a solid skin. In the inner region, hydrogen is released by thermal decomposition of MgH2 particles. Thus, the pore formation takes place parallel to the continuing solidification of the melt. The thickness of the solid skin and the density profile of the core strongly depend on the interplay between solidification velocity and kinetics of hydrogen release. By varying the melt and blowing agent properties, the structure of integral foams can be systematically changed to meet the requirements of the desired field of application of the produced component.

  4. Blowing jets as a circulation flow control to enhancement the lift of wing or generated power of wind turbine

    Directory of Open Access Journals (Sweden)

    Alexandru DUMITRACHE

    2014-06-01

    Full Text Available The goal of this paper is to provide a numerical flow analysis based on RANS equations in two directions: the study of augmented high-lift system for a cross-section airfoil of a wing up to transonic regime and the circulation control implemented by tangentially blowing jet over a highly curved surface due to Coanda effect on a rotor blade for a wind turbine. This study were analyzed the performance, sensitivities and limitations of the circulation control method based on blowing jet for a fixed wing as well as for a rotating wing. Directions of future research are identified and discussed.

  5. Analytical models for flow control in subsonic and supersonic diffusing flow paths using steady blowing and suction

    Science.gov (United States)

    Sarimurat, Mehmet Nasir

    Flow blowing/suction has multiple beneficial effects on the performance of axial flow compressors. In both low speed and high speed compressors a small amount of flow blowing and/or suction can be applied in the region of adverse pressure gradient to control the boundary layer separation and obtain high pressure ratio across the compressor. On the other hand in high speed compressors where a passage shock is present inside the passage, flow blowing/suction can also be used to manage the shock location inside the passage and increase the operating range of the compressor. In the first part of this study, an analytical model based on the integral method for boundary layer with flow blowing in incompressible flows is developed that shows the effect of mass, momentum, velocity magnitude and injection angle of the blowing flow on the behavior of the boundary layer. According to the model the change in the boundary layer momentum thickness across the blowing location is linear function of the momentum of the blowing flow and exponential function of the velocity of the blowing flow. Also if the size of the blowing slot and the velocity of the blown flow are kept constant, when the amount of the blown flow is increased by increasing the blowing angle, there is an "optimum" angle that maximizes the decrease in the momentum thickness across the blowing station. This angle is a function of the velocity ratio and it reaches an asymptotic value of around 40°. The model also shows that the change in the trailing-edge momentum thickness is an exponential function of the change in the momentum thickness across the blowing location. The developed modeled is confirmed for the NACA-65-410 low speed cascade using Computational Fluid Dynamics and a good agreement between the theory and CFD is obtained. In the second part of the thesis a quasi-1D inviscid and compressible flow theory in a converging/diverging flow passage is presented that can predict the amount of flow blowing or

  6. 一般非线性渗流方程广义解的存在唯一性与Blow-up%Existence,Uniqueness and Blow-up of Generalized Solutions to General Nonlinear Filtration Equations

    Institute of Scientific and Technical Information of China (English)

    霍振宏; 李海峰

    2008-01-01

    In this paper,we consider nonnegative solutions to Cauchy problem for the general nonlinear filtration equations ut-Dj(aij(x,t,u)Diφ(u))+bi(t,u)Diu+C(x,t,u)=0,and obtain the existence,uniqueness and blow-up in finite time of these solutions under some structure conditions.

  7. Genomic approach to studying nutritional requirements of Clostridium tyrobutyricum and other Clostridia causing late blowing defects.

    Science.gov (United States)

    Storari, Michelangelo; Kulli, Sandra; Wüthrich, Daniel; Bruggmann, Rémy; Berthoud, Hélène; Arias-Roth, Emmanuelle

    2016-10-01

    Clostridium tyrobutyricum is the main microorganism responsible for the late blowing defect in hard and semi-hard cheeses, causing considerable economic losses to the cheese industry. Deeper knowledge of the metabolic requirements of this microorganism can lead to the development of more effective control approaches. In this work, the amino acids and B vitamins essential for sustaining the growth of C. tyrobutyricum were investigated using a genomic approach. As the first step, the genomes of four C. tyrobutyricum strains were analyzed for the presence of genes putatively involved in the biosynthesis of amino acids and B vitamins. Metabolic pathways could be reconstructed for all amino acids and B vitamins with the exception of biotin (vitamin B7) and folate (vitamin B9). The biotin pathway was missing the enzyme amino-7-oxononanoate synthase that catalyzes the condensation of pimeloyl-ACP and l-alanine to 8-amino-7-oxononanoate. In the folate pathway, the missing genes were those coding for para-aminobenzoate synthase and aminodeoxychorismate lyase enzymes. These enzymes are responsible for the conversion of chorismate into para-aminobenzoate (PABA). Two C. tyrobutyircum strains whose genome was analyzed in silico as well as other 10 strains isolated from cheese were tested in liquid media to confirm these observations. 11 strains showed growth in a defined liquid medium containing biotin and PABA after 6-8 days of incubation. No strain showed growth when only one or none of these compounds were added, confirming the observations obtained in silico. Furthermore, the genome analysis was extended to genomes of single strains of other Clostridium species potentially causing late blowing, namely Clostridium beijerinckii, Clostridium sporogenes and Clostridium butyricum. Only the biotin biosynthesis pathway was incomplete for C. butyricum and C. beijerincki. In contrast, C. sporogenes showed missing enzymes in biosynthesis pathways of several amino acids as well

  8. Microchip-based 3D-Cell Culture Using Polymer Nanofibers Generated by Solution Blow Spinning.

    Science.gov (United States)

    Chen, Chengpeng; Townsend, Alexandra D; Sell, Scott A; Martin, R Scott

    2017-06-14

    Polymer nano/micro fibers have found many applications including 3D cell culture and the creation of wound dressings. The fibers can be produced by a variety of techniques that include electrospinning, the primary disadvantage of which include the requirement for a high voltage supply (which may cause issues such as polymer denaturation) and lack of portability. More recently, solution blow spinning, where a high velocity sheath gas is used instead of high voltage, has been used to generate polymer fibers. In this work, we used blow spinning to create nano/microfibers for microchip-based 3D cell culture. First, we thoroughly investigated fiber generation from a 3D printed gas sheath device using two polymers that are amenable to cell culture (polycaprolactone, PCL and polystyrene, PS) as well as the parameters that can affect PCL and PS fiber quality. Using the 3D printed sheath device, it was found that the pressure of the sheath N2 and the concentration of polymer solutions determine if fibers can be produced as well as the resulting fiber morphology. In addition, we showed how these fibers can be used for 3D cell culture by directly depositing PCL fibers in petri dishes and well plates. It is shown the fibers have good compatibility with RAW 264.7 macrophages and the PCL fiber scaffold can be as thick as 178 ± 14 μm. PCL fibers created from solution blow spinning (with the 3D printed sheath device) were then integrated with a microfluidic device for the first time to fabricate a 3D cell culture scaffold with a flow component. After culturing and stimulating macrophages on the fluidic device, it was found that the integrated 3D fibrous scaffold is a better mimic of the extracellular matrix (as opposed to a flat, 2D substrate), with enhanced nitrite accumulation (product of nitric oxide release) from macrophages stimulated with lipopolysaccharide. PS fibers were also made and integrated in a microfluidic device for 3D culture of endothelial cells, which stayed

  9. NAFTA Students'Whistle-blowing Perceptions: A Case of Sexual Harassme

    Directory of Open Access Journals (Sweden)

    Peek, L., M

    2005-07-01

    Full Text Available Whistle-blowing mechanisms in the U.S. have gained more prominence as an element of legal compliance and antifraud programs. Sexual harassment is a significant business risk in terms of financial costs and the loss of reputation. lt is important for corporations to develop sexual harassment policies and to provide mechanisms for employees toreport sexual harassment behaviors to upper level management. This paper reports on business students' responses to a possible Sexual Harassment scenario from Arthur Andersen's Business Ethics Program and the actions that the characters in the video should take in terms of whistle-blowing. l fall 2004,78 students from two U.S. universities and one Mexican and one Canadian university participated in the prolect as part of the NAFIA Challenges of Accounting and Buslness Sysfems Granf funded by the United States Department of Education Fund for the lmprovement of PostSecondary Education (FIPSE, Human Resources Develópment Canada (HRDC, and Mexico's Secretaría de Educación Pública (SEP. Students from the three NAFTA countries were shown the vignette and asked to respond to a pre-questionnaire concerning the characters' behaviors and possible actions. The students were then asked to discuss the situation and write a reoort from the points of view of the three characters in the vigneite and also to find a copy of an organizations' sexual harassment policy from the Internet. At the end of the project the students responded to a post questionnaire. The students were asked to consider whether the characters should report the possible harasser totheir supervisor, and thus engage in whistle-blowing behavior. Hypotheses are formulated for the three NAFTA'countries based on Hofstede's cultural dimensions and comparisons are made based on overall responses to the pre-and posfquestionnaire. There were significant differences, but in some cases not in the direction expected. Gender differences are also explored, but

  10. "Blow-torch phenomenon" during laser assisted excision of a thyroglossal cyst at the base of the tongue

    Directory of Open Access Journals (Sweden)

    Anitha G Bhat

    2012-01-01

    Full Text Available We report a case of blow-torch phenomenon encountered during diode laser assisted excision of a thyroglossal cyst in a child. This is first such case report from India and highlights an unusual complication which anesthesiologists need to be aware of due to the increasing use of operative laser.

  11. Whistle-blowing and workplace culture in older peoples' care: qualitative insights from the healthcare and social care workforce.

    Science.gov (United States)

    Jones, Aled; Kelly, Daniel

    2014-09-01

    Inquiries in the UK into mistreatment of older people by healthcare employees over the last 30 years have focused on introducing or supporting employee whistle-blowing. Although whistle-blowers have made an important contribution to patient safety it remains a controversial activity. The fate of whistle-blowers is bleak, often resulting in personal and professional sacrifices. Here we draw on the views of healthcare and social care employees working with older people to explore perceptions of whistle-blowing as well as alternative strategies that may be used to raise concerns about the mistreatment of patients by co-workers. Whistle-blowing was perceived as a negative term. Managers said they promoted open cultures underpinned by regular team meetings and an open-door ethos. Others described workplace norms that were somewhat at odds with these open culture ideals. Whistle-blowing was considered risky, and this led to staff creating informal channels through which to raise concerns. Those who witnessed wrongdoing were aware that support was available from external agencies but preferred local solutions and drew upon personal ethics rather than regulatory edicts to shape their responses. We argue that the importance of workplace relationships and informal channels for raising concerns should be better understood to help prevent the mistreatment of vulnerable groups. © 2014 The Authors. Sociology of Health & Illness © 2014 Foundation for the Sociology of Health & Illness/John Wiley & Sons Ltd.

  12. Identification of Clostridium tyrobutyricum as the causative agent of late blowing in cheese by species-specific PCR amplification.

    Science.gov (United States)

    Klijn, N; Nieuwenhof, F F; Hoolwerf, J D; van der Waals, C B; Weerkamp, A H

    1995-08-01

    Butyric acid fermentation, the late-blowing defect in cheese, caused by the outgrowth of clostridial spores present in raw milk, can create considerable loss of product, especially in the production of semihard cheeses like Gouda cheese, but also in grana and Gruyère cheeses. To demonstrate the causative relationship between Clostridium tyrobutyricum and late blowing in cheese, many cheesemaking experiments were performed to provoke this defect by using spores from several strains of the major dairy-related clostridia. A method of PCR amplification of a part of the 16S rRNA gene in combination with hybridization with species-specific DNA probes was developed to allow the specific detection of clostridial sequences in DNAs extracted from cheeses. The sensitivity was increased by using nested PCR. Late blowing was provoked in experimental cheeses with 28 of the 32 C. tyrobutyricum strains tested, whereas experimental cheeses made with spores from C. beijerinckii, C. butyricum, and C. sporogenes showed no signs of butyric acid fermentation. In all experimental and commercial cheeses with obvious signs of late blowing, DNA from C. tyrobutyricum was detected; in some cheeses, signals for C. beijerinckii were also found. It was concluded that only C. tyrobutyricum strains are able to cause butyric acid fermentation in cheese.

  13. Determination of the fraction of blowing agent released from refrigerator/freezer foam after decommissioning the product

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Scheutz, Charlotte

    2002-01-01

    Several halocarbons having very high global warming potential 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 revealed that most...

  14. GLOBAL EXISTENCE AND BLOW-UP OF SOLUTIONS TO A NONLOCAL EVOLUTION p-LAPLACE SYSTEM WITH NONLINEAR BOUNDARY CONDITIONS

    Institute of Scientific and Technical Information of China (English)

    Wu Xuesong; Gao Wenjie; Cao Jianwen

    2011-01-01

    In this paper, the authors discuss the global existence and blow-up of the solution to an evolution ρ-Laplace system with nonlinear sources and nonlinear boundary condition. The authors first establish the local existence of solutions, then give a necessary and sufficient condition on the global existence of the positive solution.

  15. Development of the Variable Atmosphere Testing Facility for Blow-Down Analysis of the Mars Hopper Prototype

    Energy Technology Data Exchange (ETDEWEB)

    Nathan D. Jerred; Robert C. O' Brien; Steven D. Howe; James E. O' Brien

    2013-02-01

    Recent developments at the Center for Space Nuclear Research (CSNR) on a Martian exploration probe have lead to the assembly of a multi-functional variable atmosphere testing facility (VATF). The VATF has been assembled to perform transient blow-down analysis of a radioisotope thermal rocket (RTR) concept that has been proposed for the Mars Hopper; a long-lived, long-ranged mobile platform for the Martian surface. This study discusses the current state of the VATF as well as recent blow-down testing performed on a laboratory-scale prototype of the Mars Hopper. The VATF allows for the simulation of Mars ambient conditions within the pressure vessel as well as to safely perform blow-down tests through the prototype using CO2 gas; the proposed propellant for the Mars Hopper. Empirical data gathered will lead to a better understanding of CO2 behavior and will provide validation of simulation models. Additionally, the potential of the VATF to test varying propulsion system designs has been recognized. In addition to being able to simulate varying atmospheres and blow-down gases for the RTR, it can be fitted to perform high temperature hydrogen testing of fuel elements for nuclear thermal propulsion.

  16. In vitro antimicrobial activity of solution blow spun poly(lactic acid)/ polyvinylpyrrolidone nanofibers loaded with Copaiba (Copaifera sp.) oil

    Science.gov (United States)

    In this study poly(lactic acid)(PLA) and polyvinylpyrrolidone (PVP) micro and nanofibers mats loaded with copaiba (Copaifera sp.) oil were produced by solution blow spinning (SBS). The copaiba (Copaifera sp.) oil was characterized by gas chromatography (GC). Neat PLA and four PLA/ PVP blends contain...

  17. Effect of solvent on the physical and morphological properties of poly(lactic acid) nanofibers obtained by solution blow spinning

    Science.gov (United States)

    Solution blow spinning (SBS) is a simple, safe, and inexpensive alternative to electrospinning for making nanofibers from polymer solutions. However, since SBS is a relatively new technique, there is a general lack of information on polymer solutions and properties that affect fiber morphology and i...

  18. Blow-up of solutions for the sixth-order thin film equation with positive initial energy

    Indian Academy of Sciences (India)

    Wenjun Liu; Kewang Chen

    2015-10-01

    In this paper, a sixth-order parabolic thin film equation with the initial boundary condition is considered. By using the improved energy estimate method and by constructing second-order elliptic problem, a blow-up result for certain solution with positive initial energy is established, which is an improve over the previous result of Li and Liu.

  19. The Blow-up Rate for Positive Solutions of Indefinite Parabolic Problems and Related Liouville Type Theorems

    Institute of Scientific and Technical Information of China (English)

    Ruixiang XING

    2009-01-01

    In this paper,we derive an upper bound estimate of the blow-up rate for positive solutions of indefinite parabolic equations from Liouville type theorems. We also use moving plane method to prove the related Liouville type theorems for semilinear parabolic problems.

  20. Wintertime enhancements of sea salt aerosol in polar regions consistent with a sea ice source from blowing snow

    Science.gov (United States)

    Huang, Jiayue; Jaeglé, Lyatt

    2017-03-01

    Sea salt aerosols (SSA) are generated via air bubbles bursting at the ocean surface as well as by wind mobilization of saline snow and frost flowers over sea-ice-covered areas. The relative magnitude of these sources remains poorly constrained over polar regions, affecting our ability to predict their impact on halogen chemistry, cloud formation, and climate. We implement a blowing snow and a frost flower emission scheme in the GEOS-Chem global chemical transport model, which we validate against multiyear (2001-2008) in situ observations of SSA mass concentrations at three sites in the Arctic, two sites in coastal Antarctica, and from the 2008 ICEALOT cruise in the Arctic. A simulation including only open ocean emissions underestimates SSA mass concentrations by factors of 2-10 during winter-spring for all ground-based and ship-based observations. When blowing snow emissions are added, the model is able to reproduce observed wintertime SSA concentrations, with the model bias decreasing from a range of -80 to -34 % for the open ocean simulation to -2 to +9 % for the simulation with blowing snow emissions. We find that the frost flower parameterization cannot fully explain the high wintertime concentrations and displays a seasonal cycle decreasing too rapidly in early spring. Furthermore, the high day-to-day variability of observed SSA is better reproduced by the blowing snow parameterization. Over the Arctic (> 60° N) (Antarctic, > 60° S), we calculate that submicron SSA emissions from blowing snow account for 1.0 Tg yr-1 (2.5 Tg yr-1), while frost flower emissions lead to 0.21 Tg yr-1 (0.25 Tg yr-1) compared to 0.78 Tg yr-1 (1.0 Tg yr-1) from the open ocean. Blowing snow emissions are largest in regions where persistent strong winds occur over sea ice (east of Greenland, over the central Arctic, Beaufort Sea, and the Ross and Weddell seas). In contrast, frost flower emissions are largest where cold air temperatures and open leads are co-located (over the Canadian

  1. Fluid Flow and Interfacial Phenomenon of Slag and Metal in Continuous Casting Tundish With Argon Blowing

    Institute of Scientific and Technical Information of China (English)

    WANG Jun; ZHU Miao-yong; ZHOU Hai-bing; WANG Ying

    2008-01-01

    The fluid flow and the interracial phenomenon of slag and metal in tundish with gas blowing were studied with mathematical and physical modeling,and the effects of gas flowrate,the placement of porous beam for the generation of bubbles,and the combination of flow control devices on the flow and slag-metal interface were investigated.The results show that the position of gas bubbling has a significant effect on the flow in tundish,and the placement of porous beam and gas flowrate are the two main factors affecting the entrapment of slag in tundish.The closer the porous beam to the weir,the more reasonable is the flow,which is in favor of the control of slag entrapment in tundish.

  2. Development of CFD Software To Support the Engineering of Lost Foam Pattern Blowing and Steaming

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Kenneth A. Williams; Dr. Dale M. Snider

    2003-02-04

    This CFD Project has led to a new commercial software package (Arena-flow-eps) for advanced engineering of lost foam pattern formation. Specifically, the new software models all fluid/particle/thermal phenomena during both the bead-blowing and the pattern-fusing cycles--within a single, integrated computational tool. Engineering analysis with Arena-flow-eps will enable foundries to now obtain desirable foam pattern characteristics in a reliable (consistent) manner, aided by an understanding of the fundamental fluid/thermal physics of the process. This will lead to significant reductions in casting scrap and energy usage, as well as enable future castings to satisfy stringent requirements on high-power-density and low-emissions in tomorrow's automotive and watercraft engines.

  3. Evolution PDEs with nonstandard growth conditions existence, uniqueness, localization, blow-up

    CERN Document Server

    Antontsev, Stanislav

    2015-01-01

    This monograph offers the reader a treatment of the theory of evolution PDEs with nonstandard growth conditions. This class includes parabolic and hyperbolic equations with variable or anisotropic nonlinear structure. We develop methods for the study of such equations and present a detailed account of recent results. An overview of other approaches to the study of PDEs of this kind is provided. The presentation is focused on the issues of existence and uniqueness of solutions in appropriate function spaces, and on the study of the specific qualitative properties of solutions, such as localization in space and time, extinction in a finite time and blow-up, or nonexistence of global in time solutions. Special attention is paid to the study of the properties intrinsic to solutions of equations with nonstandard growth.

  4. Morphology and Developmental Rate of the Blow Fly, Hemipyrellia ligurriens (Diptera: Calliphoridae: Forensic Entomology Applications

    Directory of Open Access Journals (Sweden)

    Nophawan Bunchu

    2012-01-01

    Full Text Available Hemipyrellia ligurriens (Diptera: Calliphoridae is a forensically important blow fly species presented in many countries. In this study, we determined the morphology of all stages and the developmental rate of H. ligurriens reared under natural ambient conditions in Phitsanulok province, northern Thailand. Morphological features of all stages based on observing under a light microscope were described and demonstrated in order to use for identification purpose. Moreover, development time in each stage was given. The developmental time of H. ligurriens to complete metamorphosis; from egg, larva, pupa to adult, took 270.71 h for 1 cycle of development. The results from this study may be useful not only for application in forensic investigation, but also for study in its biology in the future.

  5. Citric acid as multifunctional agent in blowing films of starch/PBAT

    Directory of Open Access Journals (Sweden)

    Patrícia Salomão Garcia

    2011-09-01

    Full Text Available Citric acid was used as a compatibilizer in the production of starch and PBAT films plasticized with glycerol and processed by blow extrusion. Films produced were characterized by WVP, mechanical properties, FT-IR-ATR and SEM. WPV ranged from 3.71 to 12.73×10-11 g m-1 s-1 Pa-1, while tensile strength and elongation at break ranged from 1.81 to 7.15 MPa and from 8.61 to 23.63%, respectively. Increasing the citric acid concentration improved WVP and slightly decreased film resistance and elongation. The films micrographs revealed a more homogeneous material with the addition of citric acid. However, the infrared spectra revealed little about cross-linking esterification reaction

  6. Self Induced Buoyant Blow Off in Upward Flame Spread on Thin Solid Fuels

    Science.gov (United States)

    Johnston, Michael C.; T'ien, James S.; Muff, Derek E.; Olson, Sandra L.; Ferkul, Paul V.

    2013-01-01

    Upward flame spread experiments were conducted on a thin fabric cloth consisting of 75% cotton and 25% fiberglass. The sample is sandwiched symmetrically with stainless steel plates with the exposed width varying between 2 to 8.8 cm from test to test and >1.5m tall. The bottom edge was ignited resulting in a symmetric two sided flame. For the narrower samples (. 5cm), two sided flame growth would proceed until reaching some limiting value (15-30 cm depending on sample width). Fluctuation or instability of the flame base on one side would initially become visible and then the flame base would retreat downstream and cause extinguishment on one side. Detailed examination of the still images shows that the fuel continues to vaporize from the extinguished side due to the thermally thin nature of the fuel. But, due to the remaining inert fiberglass mesh, which acts as a flashback arrestor, the extinguished side was not able to be reignited by the remaining flame. The remaining flame would then shrink in length due to the reduced heat transfer to the solid to a shorter length. The one-sided flame will spread stably with a constant speed and a constant flame length to the end of the sample. A constant length flame implies that the pyrolysis front and the burnt out fronts move at the same speed. For the wider samples (. 7cm), no one-sided extinction is observed. Two-sided flames spread all the way to the top of the sample. For these wider widths, the flames are still growing and have not reached their limiting length if it exists. Care was taken to minimize the amount of non-symmetries in the experimental configuration. Repeated tests show that blow-off can occur on either side of the sample. The flame growth is observed to be very symmetric during the growth phase and grew to significant length (>10cm) before extinction of the flame on one side. Our proposed explanation of this unusual phenomenon (i.e. stronger two ]sided flame cannot exist but weaker one-sided flame can

  7. Monitoring coal-tar pitch composition changes during air-blowing by gas chromatography.

    Science.gov (United States)

    Domínguez, A; Blanco, C; Santamaría, R; Granda, M; Blanco, C G; Menéndez, R

    2004-02-13

    A series of air-blown coal-tar pitches was studied by GC and GC-MS in order to achieve a deeper understanding of the behaviour of the different pitch components during air-blowing. Compounds present in the parent pitch were identified and quantified and then compared to those present in the air-blown pitches. The compounds observed were identical before and after the treatments, but the concentration of each compound changed with the treatment to a different extent depending on its molecular structure and consequently its reactivity to oxygen. The most reactive compounds were those with a mehylene-bridge in a five member ring, followed by those with a methyl group in their structure.

  8. Ongoing Technology and Developing Trend of Ar-blowing Purging Plug

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    An introduction of the ongoing technology of ar-gon-blowing purging plugs in China was presented in this work.Gel powders were used as starting materials to enhance the high temperature mechanical properties of the purging plugs.Composite purging plug adopting ex-trusion formed gas-purging bar and slit had its surface structural design improved,which enhanced the resist-ances to thermal shock and molten steel penetration,prolonging the service life.In addition,the safety Was greatly improved by upgrading the framework and pro-duction process,enhancing the resistance to breakout.It is indicated that the developing trend is to produce pur-ging plugs of longer service life and better gas purging rate with different starting materials and structure de-signs to meet the requirements of various metallurgical processes.

  9. Response of an artificially blown clarinet to different blowing pressure profiles

    CERN Document Server

    Bergeot, Baptiste; Vergez, Christophe; Gazengel, Bruno; Didier, Ferrand

    2013-01-01

    Using an artificial mouth with an accurate pressure control, the onset of the pressure oscillations inside the mouthpiece of a simplified clarinet is studied experimentally. Two time profiles are used for the blowing pressure: in a first set of experiments the pressure is increased at constant rates, then decreased at the same rate. In a second set of experiments the pressure rises at a constant rate and is then kept constant for an arbitrary period of time. In both cases the experiments are repeated for different increase rates. Numerical simulations using a simplified clarinet model blown with a constantly increasing mouth pressure are compared to the oscillating pressure obtained inside the mouthpiece. Both show that the beginning of the oscillations appears at a higher pressure values than the theoretical static threshold pressure, a manifestation of bifurcation delay. Experiments performed using an interrupted increase in mouth pressure show that the beginning of the oscillation occurs close to the stop ...

  10. Prediction of the dynamic oscillation threshold in a clarinet model with a linearly increasing blowing pressure

    CERN Document Server

    Bergeot, Baptiste; Vergez, Christophe; Gazengel, Bruno

    2012-01-01

    Reed instruments are modeled as self-sustained oscillators driven by the pressure inside the mouth of the musician. A set of nonlinear equations connects the control parameters (mouth pressure, lip force) to the system output, hereby considered as the mouthpiece pressure. Clarinets can then be studied as dynamical systems, their steady behavior being dictated uniquely by the values of the control parameters. Considering the resonator as a lossless straight cylinder is a dramatic yet common simplification that allows for simulations using nonlinear iterative maps. In this paper, we investigate analytically the effect of a time-varying blowing pressure on the behavior of this simplified clarinet model. When the control parameter varies, results from the so-called dynamic bifurcation theory are required to properly analyze the system. This study highlights the phenomenon of bifurcation delay and defines a new quantity, the dynamic oscillation threshold. A theoretical estimation of the dynamic oscillation thresho...

  11. Blowing Up of Sign-Changing Solutions to an Elliptic Subcritical Equation

    Institute of Scientific and Technical Information of China (English)

    GHOUDI Rabeh

    2012-01-01

    This paper is concerned with the following non linear elliptic problem involving nearly critical exponent (Pkε):(-△)ku =K(x)|u|(4k/(n-2k))-εu ir Ω,△k-1u =…=△u =u =0 on (6)Ω,where Ω is a bounded smooth domain in Rn,IRn,n ≥ 2k + 2,k ≥ 1,ε is a small positive parameter and K is a smooth positive function in (-Ω).We construct signchanging solutions of (Pεk) having two bubbles and blowing up either at two different critical points of K with the same speed or at the same critical point.

  12. Effect of polymer/clay composition on processability of polylactide nanocomposites by film blowing

    Science.gov (United States)

    Garofalo, E.; Galdi, M. R.; D'Arienzo, L.; Di Maio, L.; Incarnato, L.

    2015-12-01

    The blown extrusion of poly(lactic acid) presents several challenges mainly due to its poor elongation properties. This work deals on the possibility to enhance the processabiliy of PLA by film blowing by functionalizing the polymer with nanosilicates. In particular, two types of polylactic acid (PLA 4032D and PLA 4042D) and different types of filler, selected from montmorillonites (Cloisite 30B) and bentonites (Nanofil SE3010) families, were used to prepare the hybrid systems by using a twin-screw extruder. The interaction between the polymer and the clay was evaluated by FTIR analysis and correlated to the structure of the obtained nanocomposites in terms of clay dispersion. All the samples were then submitted to rheological measurements both in shear and elongational mode.

  13. Investigations of the LHC Emittance Blow-Up During the 2012 Proton Run

    CERN Document Server

    Kuhn, M; Baudrenghien, P; Emery, J; Guerrero, A; Hofle, W; Kain, V; Lamont, M; Mastoridis, T; Roncarolo, F; Sapinski, M; Schaumann, M; Steinhagen, R; Trad, G; Valuch, D

    2013-01-01

    About 30 % of the potential luminosity performance is lost through the different phases of the LHC cycle, mainly due to transverse emittance blow-up. Measuring the emittance growth is a difficult task with high intensity beams and changing energies. Improvements of the LHC transverse profile instrumentation helped to study various effects. A breakdown of the growth through the different phases of the LHC cycle is given as well as a comparison with the data from the LHC experiments for transverse beam size. In 2012 a number of possible sources and remedies have been studied. Among these are intra beam scattering, 50 Hz noise and the effect of the transverse damper gain. The results of the investigations are summarized in this paper. Requirements for transverse profile instrumentation for post LHC long shutdown operation to finally tackle the emittance growth are given as well.

  14. Novel Anionic Clay Adsorbents for Boiler-Blow Down Waters Reclaim and Reuse

    Energy Technology Data Exchange (ETDEWEB)

    Muhammad Sahimi; Theodore T. Tsotsis

    2005-12-01

    Our goal in this study is to utilize novel anionic clay sorbents for treating and reclaiming/reusing power-plant effluents, in particular, boiler blow-down waters containing heavy metals, such as As and Se. Developing and using novel materials for such application is dictated by the challenge posed by reclaiming and recycling these too-clean-to-clean effluent streams, generated during electricity production, whose contaminant levels are in the ppm/ppb (or even less) trace levels. During the study model blow-down streams have been treated in batch experiments. Adsorption isotherms as a function of pH/temperature have been established for both As and Se. Adsorption rates have also measured as a function of concentration, temperature, pH, and space time. For both the equilibrium and rate measurements, we have studied the As/Se interaction, and competition from background anions. A homogeneous surface diffusion model is used to describe the experimental kinetic data. The estimated diffusivity values are shown to depend on the particle size. On the other hand, a model taking into account the polycrystalline nature of these adsorbent particles, and the presence of an intercrystallite porous region predicts correctly that the surface diffusivity is particle size independent. A mathematical model to describe flow experiments in packed-beds has also been developed during phase I of this project. The goal is to validate this model with flow experiments in packed-beds during the phase II of this project, to determine the adsorption capacity under flow conditions, and to compare it with the capacity estimated from the adsorption isotherms determined from the batch studies.

  15. Solution blow spinning fibres: New immunologically inert substrates for the analysis of cell adhesion and motility.

    Science.gov (United States)

    Paschoalin, Rafaella T; Traldi, Bruna; Aydin, Gülcan; Oliveira, Juliano E; Rütten, Stephan; Mattoso, Luiz H C; Zenke, Martin; Sechi, Antonio

    2017-03-15

    The control of cell behaviour through material geometry is appealing as it avoids the requirement for complex chemical surface modifications. Significant advances in new technologies have been made to the development of polymeric biomaterials with controlled geometry and physico-chemical properties. Solution blow spinning technique has the advantage of ease of use allowing the production of nano or microfibres and the direct fibre deposition on any surface in situ. Yet, in spite of these advantages, very little is known about the influence of such fibres on biological functions such as immune response and cell migration. In this work, we engineered polymeric fibres composed of either pure poly(lactic acid) (PLA) or blends of PLA and polyethylene glycol (PEG) by solution blow spinning and determined their impact on dendritic cells, highly specialised cells essential for immunity and tolerance. We also determined the influence of fibres on cell adhesion and motility. Cells readily interacted with fibres resulting in an intimate contact characterised by accumulation of actin filaments and focal adhesion components at sites of cell-fibre interactions. Moreover, cells were guided along the fibres and actin and focal adhesion components showed a highly dynamic behaviour at cell-fibre interface. Remarkably, fibres did not elicit any substantial increase of activation markers and inflammatory cytokines in dendritic cells, which remained in their immature (inactive) state. Taken together, these findings will be useful for developing new biomaterials for applications in tissue engineering and regenerative medicine. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  16. Blow-out limits of nonpremixed turbulent jet flames in a cross flow at atmospheric and sub-atmospheric pressures

    KAUST Repository

    Wang, Qiang

    2015-07-22

    The blow-out limits of nonpremixed turbulent jet flames in cross flows were studied, especially concerning the effect of ambient pressure, by conducting experiments at atmospheric and sub-atmospheric pressures. The combined effects of air flow and pressure were investigated by a series of experiments conducted in an especially built wind tunnel in Lhasa, a city on the Tibetan plateau where the altitude is 3650 m and the atmospheric pressure condition is naturally low (64 kPa). These results were compared with results obtained from a wind tunnel at standard atmospheric pressure (100 kPa) in Hefei city (altitude 50 m). The size of the fuel nozzles used in the experiments ranged from 3 to 8 mm in diameter and propane was used as the fuel. It was found that the blow-out limit of the air speed of the cross flow first increased (“cross flow dominant” regime) and then decreased (“fuel jet dominant” regime) as the fuel jet velocity increased in both pressures; however, the blow-out limit of the air speed of the cross flow was much lower at sub-atmospheric pressure than that at standard atmospheric pressure whereas the domain of the blow-out limit curve (in a plot of the air speed of the cross flow versus the fuel jet velocity) shrank as the pressure decreased. A theoretical model was developed to characterize the blow-out limit of nonpremixed jet flames in a cross flow based on a Damköhler number, defined as the ratio between the mixing time and the characteristic reaction time. A satisfactory correlation was obtained at relative strong cross flow conditions (“cross flow dominant” regime) that included the effects of the air speed of the cross flow, fuel jet velocity, nozzle diameter and pressure.

  17. Bilateral Blow-in Fractures of the Orbital Roofs caused by the Ballistic Effect of a High-velocity Stone: An Unusual Presentation of Orbital Trauma

    Directory of Open Access Journals (Sweden)

    Mahmut Sinan Abit

    2016-06-01

    Full Text Available We describe a unique case of bilateral blow-in fractures of the orbital roofs. A previously healthy 6-year-old boy was brought to the emergency department after a stone thrown by a car wheel hit his face while sitting on the sidewalk. Maxillofacial and orbital computed tomography revealed nasoethmoid and anterior skull base fractures involving the superior orbital roofs, which were displaced towards the orbit, diagnosed as bilateral orbital roof blow-in and bilateral medial wall blow-out fractures. The patient had rhinorrhea and massive nasal bleeding. An open reduction was performed by a neurosurgeon. This unusual case had an atypical etiology.

  18. 弱耗散μ-Hunter-Saxton 方程的爆破%Blow-up of a weakly dissipative μ-Hunter-Saxton equation

    Institute of Scientific and Technical Information of China (English)

    吕红杰; 刘静静; 齐静; 刘硕

    2015-01-01

    研究了弱耗散μ-Hunter-Saxton 方程 Caucly 问题的爆破现象。给出了一个新的爆破结果,推导出爆破强解精确的爆破率。%We study the Cauchy problem of the weakly dissipative μ-Hunter-Saxton equation.The present work is main-ly concerned with blow-up phenomena of the equation.We first present a new blow-up result for strong solutions to the equation.Then,we drive the precise blow-up rate for strong solutions to the equation.

  19. Speed, amplitude, and asymmetry of lip movement in voluntary puckering and blowing expressions: implications for facial assessment.

    Science.gov (United States)

    Schmidt, Karen L; VanSwearingen, Jessie M; Levenstein, Rachel M

    2005-07-01

    The context of voluntary movement during facial assessment has significant effects on the activity of facial muscles. Using automated facial analysis, we found that healthy subjects instructed to blow produced lip movements that were longer in duration and larger in amplitude than when subjects were instructed to pucker. We also determined that lip movement for puckering expressions was more asymmetric than lip movement in blowing. Differences in characteristics of lip movement were noted using facial movement analysis and were associated with the context of the movement. The impact of the instructions given for voluntary movement on the characteristics of facial movement might have important implications for assessing the capabilities and deficits of movement control in individuals with facial movement disorders. If results generalize to the clinical context, assessment of generally focused voluntary facial expressions might inadequately demonstrate the full range of facial movement capability of an individual patient.

  20. A novel integrated approach for path following and directional stability control of road vehicles after a tire blow-out

    Science.gov (United States)

    Wang, Fei; Chen, Hong; Guo, Konghui; Cao, Dongpu

    2017-09-01

    The path following and directional stability are two crucial problems when a road vehicle experiences a tire blow-out or sudden tire failure. Considering the requirement of rapid road vehicle motion control during a tire blow-out, this article proposes a novel linearized decoupling control procedure with three design steps for a class of second order multi-input-multi-output non-affine system. The evaluating indicators for controller performance are presented and a performance related control parameter distribution map is obtained based on the stochastic algorithm which is an innovation for non-blind parameter adjustment in engineering implementation. The analysis on the robustness of the proposed integrated controller is also performed. The simulation studies for a range of driving conditions are conducted, to demonstrate the effectiveness of the proposed controller.

  1. Blowing Dust on Highway Safety: Characterizing and Modeling of Dust Emission Hot Spots in the Southern Plains

    Science.gov (United States)

    Blackwell, J., III; Li, J. J.; Kandakji, T.; Collins, J. D., Jr.; Lee, J.; Gill, T. E.

    2016-12-01

    Blowing dust and highway safety have become increasingly prevalent problems concerning human safety and welfare. Two factors precipitate wind-blown dust accidents: sudden loss of visibility, and loss of traction due to soil particles on the road surface. The project, using remote sensing and in situ measurements of surface and subsurface characteristics, will identify the location of dust emission "hotspots" and associated geomorphic features within the southwest region and panhandle (New Mexico, Texas, and Oklahoma), measure the threshold shear velocity and vegetative cover and model the results. The results of this study will provide critical information for land managers, policy makers, and highway authorities when making timely and informed potentially life-saving decisions and modifications here, in the southwest region and panhandle, as well as, anywhere else in the world where blowing dust is a hazard to highway safety.

  2. On Asymptotic Behavior and Blow-Up of Solutions for a Nonlinear Viscoelastic Petrovsky Equation with Positive Initial Energy

    Directory of Open Access Journals (Sweden)

    Gang Li

    2013-01-01

    Full Text Available This paper deals with the initial boundary value problem for the nonlinear viscoelastic Petrovsky equation utt+Δ2u−∫0tgt−τΔ2ux,τdτ−Δut−Δutt+utm−1ut=up−1u. Under certain conditions on g and the assumption that mblow-up results for solutions with positive initial energy.

  3. Extrusion foaming of thermoplastic cellulose acetate from renewable resources using a two-component physical blowing agent system

    Science.gov (United States)

    Hopmann, Ch.; Windeck, C.; Hendriks, S.; Zepnik, S.; Wodke, T.

    2014-05-01

    Thermoplastic cellulose acetate (CA) is a bio-based polymer with optical, mechanical and thermal properties comparable to those of polystyrene (PS). The substitution of the predominant petrol-based PS in applications like foamed food trays can lead to a more sustainable economic practice. However, CA is also suitable for more durable applications as the biodegradability rate can be controlled by adjusting the degree of substitutions. The extrusion foaming of CA still has to overcome certain challenges. CA is highly hydrophilic and can suffer from hydrolytic degradation if not dried properly. Therefore, the influence of residual moisture on the melt viscosity is rather high. Beyond, the surface quality of foam CA sheets is below those of PS due to the particular foaming behaviour. This paper presents results of a recent study on extrusion foamed CA, using a two-component physical blowing agent system compromising HFO 1234ze as blowing agent and organic solvents as co-propellant. Samples with different co-propellants are processed on a laboratory single screw extruder at IKV. Morphology and surface topography are investigated with respect to the blowing agent composition and the die pressure. In addition, relationships between foam density, foam morphology and the propellants are analysed. The choice of the co-propellant has a significant influence on melt-strength, foaming behaviour and the possible blow-up ratio of the sheet. Furthermore, a positive influence of the co-propellant on the surface quality can be observed. In addition, the focus is laid on the effect of external contact cooling of the foamed sheets after the die exit.

  4. GLOBAL EXISTENCE AND BLOW-UP PHENOMENA OF CLASSICAL SOLUTIONS FOR THE SYSTEM OF COMPRESSIBLE ADIABATIC FLOW THROUGH POROUS MEDIA

    Institute of Scientific and Technical Information of China (English)

    刘法贵; 孔德兴

    2004-01-01

    By means of maximum principle for nonlinear hyperbolic systems,the results given by HSIAO Ling and D.Serre was improved for Cauchy problem of compressible adiabatic flow through porous media,and a complete result on the global existence and the blow-up phenomena of classical solutions of these systems.These results show that the dissipation is strong enough to preserve the smoothness of 'small ' solution.

  5. CAUSE ANALYSIS OF EXPLOSION AND LEAKAGE OF PET BLOWING BOTTLE%PET吹塑瓶爆裂、渗漏原因分析

    Institute of Scientific and Technical Information of China (English)

    王备战

    2001-01-01

    The causes and countermeasures of explosion and leakage of PET blowing bottles for drink are analyzed. The method is also suitable for other PET blowing products.%分析了碳酸性饮料用PET吹塑瓶爆裂、渗漏的原因及其对策,该分析方法也适用于其它PET吹塑制品。

  6. Fabrication of three-dimensional micro-nanofiber structures by a novel solution blow spinning device

    Directory of Open Access Journals (Sweden)

    Feng Liang

    2017-02-01

    Full Text Available The fabrication of three-dimensional scaffolds has attracted more attention in tissue engineering. The purpose of this study is to explore a new method for the fabrication of three-dimensional micro-nanofiber structures by combining solution blow spinning and rotating collector. In this study, we successfully fabricated fibers with a minimum diameter of 200 nm and a three-dimensional structure with a maximum porosity of 89.9%. At the same time, the influence of various parameters such as the solvent volatility, the shape of the collector, the feed rate of the solution and the applied gas pressure were studied. It is found that solvent volatility has large effect on the formation of the three-dimensional shape of the structure. The shape of the collector affects the porosity and fiber distribution of the three-dimensional structure. The fiber diameter and fiber uniformity can be controlled by adjusting the solution feed rate and the applied gas pressure. It is feasible to fabricate high-quality three-dimensional micro-nanofiber structure by this new method, which has great potential in tissue engineering.

  7. Local correlations for flap gap oscillatory blowing active flow control technology

    Directory of Open Access Journals (Sweden)

    Cătălin NAE

    2010-09-01

    Full Text Available Active technology for oscillatory blowing in the flap gap has been tested at INCAS subsonic wind tunnel in order to evaluate this technology for usage in high lift systems with active flow control. The main goal for this investigation was to validate TRL level 4 for this technology and to extend towards flight testing. CFD analysis was performed in order to identify local correlations with experimental data and to better formulate a design criteria so that a maximum increase in lift is possible under given geometrical constraints. Reference to a proposed metric for noise evaluation is also given. This includes basic 2D flow cases and also 2.5D configurations. In 2.5D test cases this work has been extended so that the proposed system may be selected as a mature technology in the JTI Clean Sky, Smart Fixed Wing Aircraft ITD. Complex post-processing of the experimental and CFD data was mainly oriented towards system efficiency and TRL evaluation for this active technology.

  8. A Digital System for Longitudinal Emittance Blow-Up in the LHC

    CERN Document Server

    JaussI, M; Baudrenghien, P; Butterworth, A; Sanchez-Quesada, J; Shaposhnikova, E; Tuckmantel, J

    2011-01-01

    In order to preserve beam stability with nominal bunch intensity in the LHC, longitudinal emittance blow-up is performed during the energy ramp by injecting phase noise in the main accelerating cavities. The noise spectrum spans a small frequency band around the synchrotron frequency. It is generated continuously in software and streamed digitally into the Digital Signal Processor (DSP) of the Beam Control system where it is added to the pick-up signal of the beam phase loop, resulting in a phase modulation of the accelerating RF. In order to achieve reproducible results, a feedback system, using as input the measured bunch lengths averaged over each ring, controls the strength of the excitation, allowing the operator to simply set a target bunch length. The spectrum of the noise is adjusted to excite the core of the bunch only, extending to the desired bunch length. As it must follow the evolution of the synchrotron frequency through the ramp, it is automatically calculated by the LHC settings management sof...

  9. Large surface radiative forcing from topographic blowing snow residuals measured in the High Arctic at Eureka

    Directory of Open Access Journals (Sweden)

    G. Lesins

    2009-03-01

    Full Text Available Ice crystals, also known as diamond dust, are suspended in the boundary layer air under clear sky conditions during most of the Arctic winter in Northern Canada. Occasionally ice crystal events can produce significantly thick layers with optical depths in excess of 2.0 even in the absence of liquid water clouds. Four case studies of high optical depth ice crystal events at Eureka in the Nunavut Territory of Canada during the winter of 2006/07 are presented. They show that the measured ice crystal surface infrared downward radiative forcing ranged from 8 to 36 W m−2 in the wavelength band from 5.6 to 20 μm for 532 nm optical depths ranging from 0.2 to 1.7. MODIS infrared and visible images and the operational radiosonde wind profile were used to show that these high optical depth events were caused by surface snow being blown off 600 to 800 m high mountain ridges about 20 to 30 km North-West of Eureka and advected by the winds towards Eureka as they settled towards the ground within the highly stable boundary layer. This work presents the first study that demonstrates the important role that surrounding topography plays in determining the occurrence of high optical depth ice crystal events from residual blowing snow that becomes a source of boundary layer ice crystals distinct from the classical diamond dust phenomenon.

  10. Development of analysis technique to predict the material behavior of blowing agent

    Science.gov (United States)

    Hwang, Ji Hoon; Lee, Seonggi; Hwang, So Young; Kim, Naksoo

    2014-11-01

    In order to numerically simulate the foaming behavior of mastic sealer containing the blowing agent, a foaming and driving force model are needed which incorporate the foaming characteristics. Also, the elastic stress model is required to represent the material behavior of co-existing phase of liquid state and the cured polymer. It is important to determine the thermal properties such as thermal conductivity and specific heat because foaming behavior is heavily influenced by temperature change. In this study, three models are proposed to explain the foaming process and material behavior during and after the process. To obtain the material parameters in each model, following experiments and the numerical simulations are performed: thermal test, simple shear test and foaming test. The error functions are defined as differences between the experimental measurements and the numerical simulation results, and then the parameters are determined by minimizing the error functions. To ensure the validity of the obtained parameters, the confirmation simulation for each model is conducted by applying the determined parameters. The cross-verification is performed by measuring the foaming/shrinkage force. The results of cross-verification tended to follow the experimental results. Interestingly, it was possible to estimate the micro-deformation occurring in automobile roof surface by applying the proposed model to oven process analysis. The application of developed analysis technique will contribute to the design with minimized micro-deformation.

  11. Prevention of late blowing defect by reuterin produced in cheese by a Lactobacillus reuteri adjunct.

    Science.gov (United States)

    Gómez-Torres, Natalia; Ávila, Marta; Gaya, Pilar; Garde, Sonia

    2014-09-01

    In this study, reuterin-producing Lactobacillus reuteri INIA P572 was added to cheese as an adjunct culture together with 50 or 100 mM glycerol (required for reuterin production), with the aim of controlling Clostridium tyrobutyricum CECT 4011 growth and preventing the late blowing defect (LBD) of cheese caused by this strain. L. reuteri survived cheese manufacture and produced reuterin in situ, detected at 6 and 24 h. However, the produced reuterin was enough to inhibit the growth of Clostridium, showing undetectable spore counts from day 30 onward and, therefore, to prevent cheese LBD during ripening (60 d, 14 °C). The acidification of these cheeses was not affected, although from day 14 they showed significantly lower lactococci counts than cheese made only with the starter (control cheese). Cheeses with LBD showed lower levels of lactic acid than control cheese and the formation of propionic and butyric acids, but cheeses with reuterin showed the same organic acids profile than control cheese. The cheese made with L. reuteri and 100 mM glycerol showed a light pink colour, not observed in the cheese made with L. reuteri and 50 mM glycerol. These results demonstrated a potent anti-clostridial activity of reuterin produced in an actual food product like cheese, and proved to be a novel approach to prevent LBD of cheese.

  12. Structures and physical properties of rigid polyurethane foams with water as the sole blowing agent

    Institute of Scientific and Technical Information of China (English)

    LI; Xiaobin; CAO; Hongbin

    2006-01-01

    Rigid polyurethane foams blown by varying water level were prepared in this study. The structures and physical properties of rigid polyurethane foams blown by water were measured with FT-IR, universal testing machine (Instron3365), scanning electron microscope (SEM) and differential scanning calorimeter (DSC). The results show that polyurea and polybiuret were the typical characteristics, and the cream time and gel time were shorter for the fully water blown rigid foams than that for the fully cyclopentane blown foams. The density of foam samples decreased from 45.0 kg/m3 to 27.4 kg/m3 with the increase of water level from 3 pph to 7 pph. Compressive strength exhibited the similar behavior with density. The average cell size of foam samples ranged from 241цm to 356цm with the increase of water level from 3 pph to 7 pph, respectively. At the same time, poorer dimensional stability was encountered with the increase of average cell size due to fast diffusion rate of CO2 out of the foam. The results of thermal analysis show that the glass transition temperature (Tg) shifted to a higher temperature with the increase of isocyanate level when more water was used as chemical blowing agent.

  13. [Superparamagnetic Cobalt Ferrite Nanoparticles "Blow up" Spatial Ordering of Double-stranded DNA Molecules].

    Science.gov (United States)

    Yevdokimov, Yu M; Pershina, A G; Salyanov, V I; Magaeva, A A; Popenko, V I; Shtykova, E V; Dadinova, L A; Skuridin, S G

    2015-01-01

    The formation of cholesteric liquid-crystalline dispersions formed by double-stranded DNA molecules, handled by positively charged superparamagnetic cobalt ferrite nanoparticles, as well as action of these nanoparticles on DNA dispersion, are considered. The binding of magnetic nanoparticles to the linear double-stranded DNA in solution of high ionic strength (0.3 M NaCl) and subsequent phase exclusion of these complexes from polyethylene glycol-containing solutions lead to their inability to form dispersions, whose particles do possess the spatially twisted arrangement of neighboring double-stranded DNA molecules. The action of magnetic nanoparticles on DNA dispersion (one magnetic nanoparticle per one double-stranded DNA molecule) results in such "perturbation" of DNA structure at sites of magnetic nanoparticles binding that the regular spatial structure of DNA dispersion particles "blows up"; this process is accompanied by disappearance of both abnormal optical activity and characteristic Bragg maximum on the small-angle X-ray scattering curve. Allowing with the fact that the physicochemical properties of the DNA liquid-crystalline dispersion particles reflect features of spatial organization of these molecules in chromosomes of primitive organisms, it is possible, that the found effect can have the relevant biological consequences.

  14. Big Bang, Blow Up, and Modular Curves: Algebraic Geometry in Cosmology

    CERN Document Server

    Manin, Yuri I

    2014-01-01

    We introduce some algebraic geometric models in cosmology related to the "boundaries" of space--time: Big Bang, Mixmaster Universe, Penrose's crossovers between aeons. We suggest to model the kinematics of Big Bang using the algebraic geometric (or analytic) blow up of a point $x$. This creates a boundary which consists of the projective space of tangent directions to $x$ and possibly of the light cone of $x$. We argue that time on the boundary undergoes the Wick rotation and becomes purely imaginary. The Mixmaster (Bianchi IX) model of the early history of the universe is neatly explained in this picture by postulating that the reverse Wick rotation follows a hyperbolic geodesic connecting imaginary time axis to the real one. Penrose's idea to see the Big Bang as a sign of crossover from "the end of previous aeon" of the expanding and cooling Universe to the "beginning of the next aeon" is interpreted as an identification of a natural boundary of Minkowski space at infinity with the Bing Bang boundary.

  15. A Review of the Fundamental Principles and Applications of Solution Blow Spinning.

    Science.gov (United States)

    Daristotle, John L; Behrens, Adam M; Sandler, Anthony D; Kofinas, Peter

    2016-12-28

    Solution blow spinning (SBS) is a technique that can be used to deposit fibers in situ at low cost for a variety of applications, which include biomedical materials and flexible electronics. This review is intended to provide an overview of the basic principles and applications of SBS. We first describe a method for creating a spinnable polymer solution and stable polymer solution jet by manipulating parameters such as polymer concentration and gas pressure. This method is based on fundamental insights, theoretical models, and empirical studies. We then discuss the unique bundled morphology and mechanical properties of fiber mats produced by SBS, and how they compare with electrospun fiber mats. Applications of SBS in biomedical engineering are highlighted, showing enhanced cell infiltration and proliferation versus electrospun fiber scaffolds and in situ deposition of biodegradable polymers. We also discuss the impact of SBS in applications involving textiles and electronics, including ceramic fibers and conductive composite materials. Strategies for future research are presented that take advantage of direct and rapid polymer deposition via cost-effective methods.

  16. Assessment of the Possibility of Using Reclaimed Materials for Making Cores by the Blowing Method

    Directory of Open Access Journals (Sweden)

    Dańko R.

    2017-03-01

    Full Text Available The cumulative results of investigations of the possibility of using the reclaimed materials after the mechanical, thermal or mechanical-thermal reclamation for making cores by means of the blowing method in the alkaline CO2 technology, are presented in the paper. Three kinds of spent sands: with furfuryl resin, bentonite and alkaline phenolic resin, obtained from the foundry, were subjected to three kinds of reclamation: mechanical, thermal and combined mechanical-thermal, applying for this aim adequate experimental devices. The obtained reclaims were assessed with regard to the degree of the matrix liberation from the determined binding material. Reclaims of moulding sands with binders of the form of resin were assessed with regard to ignition loss values and pH reaction, while reclaims of moulding sands with bentonite with regard to the residual clay content and pH value. In all cases the results of the performed sieve analyses were estimated and the average characteristic diameter dl was determined. The reclaimed matrix was applied as a full substitute of the fresh high-silica sand in typical procedures of preparing core sands used for making shaped samples for bending strength investigations, Rgu.

  17. CROSS DIFFUSION AND NONLINEAR DIFFUSION PREVENTING BLOW UP IN THE KELLER–SEGEL MODEL

    KAUST Repository

    CARRILLO, JOSÉ ANTONIO

    2012-12-01

    A parabolic-parabolic (Patlak-)Keller-Segel model in up to three space dimensions with nonlinear cell diffusion and an additional nonlinear cross-diffusion term is analyzed. The main feature of this model is that there exists a new entropy functional, yielding gradient estimates for the cell density and chemical concentration. For arbitrarily small cross-diffusion coefficients and for suitable exponents of the nonlinear diffusion terms, the global-in-time existence of weak solutions is proved, thus preventing finite-time blow up of the cell density. The global existence result also holds for linear and fast diffusion of the cell density in a certain parameter range in three dimensions. Furthermore, we show L∞ bounds for the solutions to the parabolic-elliptic system. Sufficient conditions leading to the asymptotic stability of the constant steady state are given for a particular choice of the nonlinear diffusion exponents. Numerical experiments in two and three space dimensions illustrate the theoretical results. © 2012 World Scientific Publishing Company.

  18. Instantaneous blow-up of semilinear non-autonomous equations with fractional diffusion

    Directory of Open Access Journals (Sweden)

    Jose Villa-Morales

    2017-05-01

    Full Text Available We consider the Cauchy initial value problem $$\\displaylines{ \\frac{\\partial }{\\partial t}u(t,x =k(t\\Delta _{\\alpha}u(t,x+h(tf(u(t,x, \\cr u(0,x = u_0(x, }$$ where $\\Delta _{\\alpha }$ is the fractional Laplacian for $0<\\alpha \\leq 2$. We prove that if the initial condition $u_0$ is non-negative, bounded and measurable then the problem has a global integral solution when the source term f is non-negative, locally Lipschitz and satisfies the generalized Osgood's condition $$ \\int_{\\|u_0\\|_{\\infty }}^{\\infty }\\frac{ds}{f(s}\\geq \\int_0^{\\infty}h(sds. $$ Also, we prove that if the initial data is unbounded then the generalized Osgood's condition does not guarantee the existence of a global solution. It is important to point out that the proof of the existence hinges on the role of the function h. Analogously, the function k plays a central role in the proof of the instantaneous blow-up.

  19. MIXING LOSSES INVESTIGATION DOWNSTREAM OF TURBINE BLADE CASCADE WITH COOLANT FLOW BLOWING

    Directory of Open Access Journals (Sweden)

    ASSIM HAMEED YOUSIF

    2011-04-01

    Full Text Available A major cause of noise and vibration characteristics of turbomachinery has caused by wakes. The characteristics of the wake, the wake decay, the path that it follows, and the mechanisms of mixing losses generated due to the mixing of blade trailing edge cold jet issued into the hot cross flow are important to find adequate solution to the problem. At the present work the wake characteristic was observed by introducing experimental work inside a cascade test rig to investigate the wake domain downstream of blade cascade with the aid of five-hole probe. The case studies were done with cold jets blowing ratios 1.58, 1.667 and 1.935 with jet stream wise angle and jet lateral injection angle 37.5° and 35 º respectively. The measurement showed that there is a certain harmonization in the region of high reverse pressure loss coefficient which reflects the concentration of wake region. Also it was observed three distinct wake regions located in the centre of the passage vortex region. The wake characteristics measurements of the movement path, the growth of wake width, and the physical awareness of the wake propagating may help to explain the mechanisms of mixing losses.

  20. Vertical blow ups of capillary surfaces in $R^3$, Part 2: Nonconvex corners

    Directory of Open Access Journals (Sweden)

    Kirk Lancaster

    2008-12-01

    Full Text Available The goal of this note is to continue the investigation started in Part One of the structure of "blown up" sets of the form $mathcal{P}imes mathbb{R}$ and $mathcal{N}imes mathbb{R}$ when $mathcal{P}, mathcal{N} subset mathbb{R}^{2}$ and $mathcal{P}$ (or $mathcal{N}$ minimizes an appropriate functional and the domain has a nonconvex corner. Sets like $mathcal{P}imes mathbb{R}$ can be the limits of the blow ups of subgraphs of solutions of capillary surface or other prescribed mean curvature problems, for example. Danzhu Shi recently proved that in a wedge domain $Omega$ whose boundary has a nonconvex corner at a point $O$ and assuming the correctness of the Concus-Finn Conjecture for contact angles $0$ and $pi$, a capillary surface in positive gravity in $Omegaimesmathbb{R}$ must be discontinuous under certain conditions. As an application, we extend the conclusion of Shi's Theorem to the case where the prescribed mean curvature is zero without any assumption about the Concus-Finn Conjecture.

  1. Blow-off characteristics of turbulent premixed flames in curved-wall Jet Burner

    KAUST Repository

    Mansour, Morkous S.

    2015-08-02

    This study concerns the flame dynamics of a curved-wall jet (CWJ) stabilized turbulent premixed flame as it approaches blow-off conditions. Time resolved OH planar laser-induced fluorescence (PLIF) delineated reaction zone contours and simultaneously stereoscopic particle image velocimetry (SPIV) quantified the turbulent flow field features. Ethylene/air flames were stabilized in CWJ burner to determine the sequence of events leading to blowoff. For stably burning flames far from blowoff, flames are characterized with a recirculation zone (RZ) upstream for flame stabilization followed by an intense turbulent interaction jet (IJ) and merged-jet regions downstream; the flame front counterparts the shear layer vortices. Near blowoff, as the velocity of reactants increases, high local stretch rates exceed the extinction stretch rates instantaneously resulting in localized flame extinction along the IJ region. As Reynolds number (Re) increases, flames become shorter and are entrained by larger amounts of cold reactants. The increased strain rates together with heat loss effects result in further fragmentation of the flame, eventually leading to the complete quenching of the flame. This is explained in terms of local turbulent Karlovitz stretch factor (K) and principal flow strain rates associated with C contours. Hydrogen addition and increasing the RZ size lessen the tendency of flames to be locally extinguished.

  2. Controlling of blow-up responses by nonlinear PT -symmetric coupling

    Science.gov (United States)

    Karthiga, S.; Chandrasekar, V. K.; Senthilvelan, M.; Lakshmanan, M.

    2017-03-01

    We investigate the dynamics of a coupled waveguide system with competing linear and nonlinear loss-gain profiles which can facilitate power saturation. We show the usefulness of the model in achieving unidirectional beam propagation. In this regard, the considered type of coupled waveguide system has two drawbacks: (i) difficulty in achieving perfect isolation of light in a waveguide and (ii) existence of blow-up-type behavior for certain input power situations. We here show a nonlinear PT -symmetric coupling that helps to overcome these two drawbacks. Such a nonlinear coupling has close connection with the phenomenon of stimulated Raman scattering. In particular, we have elucidated the role of this nonlinear coupling using an integrable PT -symmetric situation. In particular, using the integrals of motion, we have reduced this coupled waveguide problem to the problem of dynamics of a particle in a potential. With the latter picture, we have clearly illustrated the role of the considered nonlinear coupling. The above PT -symmetric case corresponds to a limiting form of a general equation describing the phenomenon of stimulated Raman scattering. We also point out the ability to transport light unidirectionally even in this general case.

  3. Biopolymer Blends Based on Poly (lactic acid: Shear and Elongation Rheology/Structure/Blowing Process Relationships

    Directory of Open Access Journals (Sweden)

    Racha Al-Itry

    2015-05-01

    Full Text Available This study was dedicated to the blown film extrusion of poly(lactic acid, which mainly presents poor shear and elongation viscosities, and its blends. In order to enhance its melt strength, two main routes were selected (i a structural modification through chain extension and branching mechanisms by adding a reactive multifunctional epoxide (named Joncryl and (ii blending with poly(butylene adipate-co-terephtalate, named PBAT in presence (or not of Joncryl. The effects of the reactive agent on the shear and elongation rheology, morphological, and interfacial properties of the blends were systematically investigated. A decrease of the interfacial tension has been also demonstrated according to the deformed drop retraction method (DDRM. Hence, the role of Joncryl as a compatibilizer was highlighted. Consequently, finer morphology of the dispersed phase was obtained. Furthermore, the impact of the two modification routes on the blown film extrusion ability of PLA has been studied. Based on the improved shear and elongational rheological properties, a great enlargement of the blowing processing window of PLA modified with Joncryl was demonstrated. Indeed, with the addition of Joncryl into PLA–PBAT blends, a reduction of the instability defects has been detected. Finally, the induced crystalline structure and the thermo-mechanical properties of blown films were shown to be improved.

  4. Interaction of antimicrobial preservatives with blow-fill-seal packs: correlating sorption with solubility parameters.

    Science.gov (United States)

    Amin, Aeshna; Dare, Manish; Sangamwar, Abhay; Bansal, Arvind Kumar

    2012-01-01

    The aim of this work was to study the interaction of four commonly used ophthalmic antimicrobial preservatives [benzyl alcohol (BA), chlorbutol (CBL), benzalkonium chloride (BKC), and chlorhexidine gluconate (CG)] with Blow-Fill-Seal (BFS) packs. Effect of packaging material [low-density polyethylene (LDPE), polypropylene (PP)], humidity (25% RH, 75% RH) and concentration (0.5, 1.0, 2.0 mM BA/CBL in LDPE) was studied. BKC and CG gave negligible loss (preservative. Loss of BA switched from Case II to anomalous behavior with increasing initial concentration. A two-stage sorption behavior was inherent at all concentrations. Loss of CBL followed anomalous behavior with biphasic kinetics of loss. It was concluded that all the four preservatives were appropriate for use in PP BFS packs. However, only BKC and CG were amenable to be used in LDPE BFS packs. Lastly, an empirical expression consisting of the "solubility parameter distance" and "molar volume" of preservatives was developed to correlate the preservative loss in LDPE with the physicochemical properties of the preservatives.

  5. Viscous Flows Driven by Uniform Shear over a Porous Stretching Sheet in the Presence of Suction/Blowing

    Directory of Open Access Journals (Sweden)

    Samir Kumar Nandy

    2014-01-01

    Full Text Available An analysis is carried out to study the steady two-dimensional flow of an incompressible viscous fluid past a porous deformable sheet, which is stretched in its own plane with a velocity proportional to the distance from the fixed point subject to uniform suction or blowing. A uniform shear flow of strain rate β is considered over the stretching sheet. The analysis of the result obtained shows that the magnitude of the wall shear stress increases with the increase of suction velocity and decreases with the increase of blowing velocity and this effect is more pronounced for suction than blowing. It is seen that the horizontal velocity component (at a fixed streamwise position along the plate increases with the increase in the ratio of shear rate β and stretching rate (c (i.e., β/c and there is an indication of flow reversal. It is also observed that this flow reversal region increases with the increase in β/c.

  6. Control of Flow Structure on Non-Slender Delta Wing: Bio-inspired Edge Modifications, Passive Bleeding, and Pulsed Blowing

    Science.gov (United States)

    Yavuz, Mehmet Metin; Celik, Alper; Cetin, Cenk

    2016-11-01

    In the present study, different flow control approaches including bio-inspired edge modifications, passive bleeding, and pulsed blowing are introduced and applied for the flow over non-slender delta wing. Experiments are conducted in a low speed wind tunnel for a 45 degree swept delta wing using qualitative and quantitative measurement techniques including laser illuminated smoke visualization, particle image velocimety (PIV), and surface pressure measurements. For the bio-inspired edge modifications, the edges of the wing are modified to dolphin fluke geometry. In addition, the concept of flexion ratio, a ratio depending on the flexible length of animal propulsors such as wings, is introduced. For passive bleeding, directing the free stream air from the pressure side of the planform to the suction side of the wing is applied. For pulsed blowing, periodic air injection through the leading edge of the wing is performed in a square waveform with 25% duty cycle at different excitation frequencies and compared with the steady and no blowing cases. The results indicate that each control approach is quite effective in terms of altering the overall flow structure on the planform. However, the success level, considering the elimination of stall or delaying the vortex breakdown, depends on the parameters in each method.

  7. Towards improving the efficiency of blowing through a permeable wall and prospects of its use for a flow control

    Science.gov (United States)

    Kornilov, V. I.; Boiko, A. V.

    2016-10-01

    Modern achievements, status, and prospects of studies on reducing the turbulent friction and aerodynamic drag with the help of the blowing through a permeable wall are discussed. The main focus is placed upon a physical modeling of the process of boundary layer blowing in the framework of the dimensional theory, a critical analysis of experimental and numerical results for different conditions of air blowing through a high-tech finely perforated wall including the case of external-pressure-flow air supply in wind tunnel, and elicitation of the physical mechanisms responsible for the reduction of turbulent friction at flow-exposed surfaces. It is shown that the use of air supply through the micro-perforated wall with low effective roughness, which is manufactured in compliance with the highest necessary requirements to quality and geometry of orifices, is quite a justified means for easy, affordable, and reliable control of near-wall turbulent flows in laboratory experiment and numerical simulation. This approach can provide a sustained reduction of local skin friction coefficient along flat plate, which in some cases reaches 90%. At the request of all authors of the paper and with the agreement of the Proceedings Editor, an updated version of this article was published on 26 October 2016. The original version supplied to AIP Publishing contained a misrepresentation in Figure 1. This has been corrected in the updated and republished article.

  8. Impact of Cloud and Blowing Snow on Ice Sheet Altimetry: a Comparison between ICESat and ICESat-2

    Science.gov (United States)

    Yang, Y.; Marshak, A.; Palm, S. P.; Varnai, T.

    2015-12-01

    Clouds and blowing snow have long been a concern for lidar altimetry. Scattering inside the layer increases the photon path and makes the surface appear further away from the satellite. This effect is referred to as "atmospheric path delay". The ICESat and ICESat-2 missions' high accuracy requirement on the ice/snow surface elevation measurements makes understanding and quantifying this effect essential. We have developed a comprehensive framework that can simulate the analog waveform behavior of the Geoscience Laser Altimeter System (GLAS) onboard ICESat and the photon counting signal of the Advanced Topographic Laser Altimeter System (ATLAS) onboard ICESat-2. In this presentation, we will (1) review the cloud and blowing snow distributions over the polar ice sheets; (2) discuss how different factors affect the value of the atmospheric path delay, such as scattering layer height, optical thickness, and lidar field of view (FOV); (3) demonstrate that the delay is much less for ICESat-2 (centimeter level) compared to ICESat (decimeter level) due to the much smaller lidar FOV; (4) show the cloud detectability difference between ICESat and ICESat-2 and its implication to path delay corrections. The effect of cloud and blowing snow on first photon bias will also be discussed.

  9. Presidential Green Chemistry Challenge: 1996 Greener Reaction Conditions Award

    Science.gov (United States)

    Presidential Green Chemistry Challenge 1996 award winner, Dow Chemical Company, developed a process to manufacture polystyrene foam sheet packaging that uses carbon dioxide (CO2) as a blowing agent, eliminating CFC-12 and HCFC-22.

  10. Effect of air-blowing duration on the bond strength of current one-step adhesives to dentin.

    Science.gov (United States)

    Fu, Jiale; Saikaew, Pipop; Kawano, Shimpei; Carvalho, Ricardo M; Hannig, Matthias; Sano, Hidehiko; Selimovic, Denis

    2017-08-01

    To evaluate the influence of different air-blowing durations on the micro-tensile bond strength (μTBS) of five current one-step adhesive systems to dentin. One hundred and five caries-free human molars and five current one-step adhesive systems were used: ABU (All Bond Universal, Bisco, Inc.), CUB (CLEARFIL™ Universal Bond, Kuraray), GPB (G-Premio BOND, GC), OBA (OptiBond All-in-one, Kerr) and SBU (Scotchbond Universal, 3M ESPE). The adhesives were applied to 600 SiC paper-flat dentin surfaces according to each manufacturer's instructions and were air-dried with standard, oil-free air pressure of 0.25MPa for either 0s, 5s, 15s or 30s before light-curing. Bond strength to dentin was determined by using μTBS test after 24h of water storage. The fracture pattern on the dentin surface was analyzed by SEM. The resin-dentin interface of untested specimens was visualized by panoramic SEM image. Data from μTBS were analyzed using two-way ANOVA (adhesive vs. air-blowing time), and Games-Howell (a=0.05). Two-way ANOVA revealed a significant effect of materials (p=0.000) and air-blowing time (p=0.000) on bond strength to dentin. The interaction between factors was also significantly different (p=0.000). Maximum bond strength for each system were recorded, OBA/15s (76.34±19.15MPa), SBU/15s (75.18±12.83MPa), CUB/15s (68.23±16.36MPa), GPB/30s (55.82±12.99MPa) and ABU/15s (44.75±8.95MPa). The maximum bond strength of OBA and SUB were significantly higher than that of GPB and ABU (psystems is material-dependent (p=0.000), and was influenced by air-blowing duration (p=0.000). For the current one-step adhesive systems, higher bond strengths could be achieved with prolonged air-blowing duration between 15-30s. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  11. Study on switch mode about bottom blowing and nitrogen pickup for 260 t top-bottom combined blowing converter%260t复吹转炉底吹模式及钢水增氮的研究

    Institute of Scientific and Technical Information of China (English)

    苏小利; 刘文飞

    2011-01-01

    分析了不同底吹流量和氮氩切换时间对钢中氮含量的影响,得出采用吹氧量在70%进行氮氩切换的底吹模式或者通过小流量底吹氮(不大于0.077m3/(min·t))在吹氧85%切换的底吹模式,钢水叫(N)可以控制在30×10^-6以下;同时通过对冶炼过程和出钢过程的分析,认为转炉最好采用沸腾方式出钢,如果在出钢过程中需要加脱氧合金,可采用分批加入的方式以及控制补吹时间和出钢时间等措施抑制钢水增氮。%Effects of different flow rate of the bottom blow and switch over time of nitro- gen and argon on the nitrogen content in steel are analyzed. It's concluded that w(N) in the hot metal can be controlled in the limit of less than 30 ×10^-6 by adopting the switch over mode of nitrogen and argon with 70 ~ oxygen supply or by taking the bottom blow mode of 85 % oxygen supply switch over with a small quantity of nitrogen bottom blow (not larger than 0. 077 m3/(min·t)). In the meanwhile by analysis on the processes of smelting and tapping of steel it is affirmed that the best tapping mode for converter is rimming pattern. If addition of deoxidation alloy elements is required in tapping such a few measures as feeding in batch pattern and controlling the oxygen blow time and tapping time have to be taken to prevent against nitrogen pickup in the hot metal.

  12. The development of three-dimensional adjoint method for flow control with blowing in convergent-divergent nozzle flows

    Science.gov (United States)

    Sikarwar, Nidhi

    multiple experiments or numerical simulations. Alternatively an inverse design method can be used. An adjoint optimization method can be used to achieve the optimum blowing rate. It is shown that the method works for both geometry optimization and active control of the flow in order to deflect the flow in desirable ways. An adjoint optimization method is described. It is used to determine the blowing distribution in the diverging section of a convergent-divergent nozzle that gives a desired pressure distribution in the nozzle. Both the direct and adjoint problems and their associated boundary conditions are developed. The adjoint method is used to determine the blowing distribution required to minimize the shock strength in the nozzle to achieve a known target pressure and to achieve close to an ideally expanded flow pressure. A multi-block structured solver is developed to calculate the flow solution and associated adjoint variables. Two and three-dimensional calculations are performed for internal and external of the nozzle domains. A two step MacCormack scheme based on predictor- corrector technique is was used for some calculations. The four and five stage Runge-Kutta schemes are also used to artificially march in time. A modified Runge-Kutta scheme is used to accelerate the convergence to a steady state. Second order artificial dissipation has been added to stabilize the calculations. The steepest decent method has been used for the optimization of the blowing velocity after the gradients of the cost function with respect to the blowing velocity are calculated using adjoint method. Several examples are given of the optimization of blowing using the adjoint method.

  13. Age estimation during the blow fly intra-puparial period: a qualitative and quantitative approach using micro-computed tomography.

    Science.gov (United States)

    Martín-Vega, Daniel; Simonsen, Thomas J; Wicklein, Martina; Hall, Martin J R

    2017-05-04

    Minimum post-mortem interval (minPMI) estimates often rely on the use of developmental data from blow flies (Diptera: Calliphoridae), which are generally the first colonisers of cadavers and, therefore, exemplar forensic indicators. Developmental data of the intra-puparial period are of particular importance, as it can account for more than half of the developmental duration of the blow fly life cycle. During this period, the insect undergoes metamorphosis inside the opaque, barrel-shaped puparium, formed by the hardening and darkening of the third instar larval cuticle, which shows virtually no external changes until adult emergence. Regrettably, estimates based on the intra-puparial period are severely limited due to the lack of reliable, non-destructive ageing methods and are frequently based solely on qualitative developmental markers. In this study, we use non-destructive micro-computed tomography (micro-CT) for (i) performing qualitative and quantitative analyses of the morphological changes taking place during the intra-puparial period of two forensically relevant blow fly species, Calliphora vicina and Lucilia sericata, and (ii) developing a novel and reliable method for estimating insect age in forensic practice. We show that micro-CT provides age-diagnostic qualitative characters for most 10% time intervals of the total intra-puparial period, which can be used over a range of temperatures and with a resolution comparable to more invasive and time-consuming traditional imaging techniques. Moreover, micro-CT can be used to yield a quantitative measure of the development of selected organ systems to be used in combination with qualitative markers. Our results confirm micro-CT as an emerging, powerful tool in medico-legal investigations.

  14. Arctic Sea Salt Aerosol from Blowing Snow and Sea Ice Surfaces - a Missing Natural Source in Winter

    Science.gov (United States)

    Frey, M. M.; Norris, S. J.; Brooks, I. M.; Nishimura, K.; Jones, A. E.

    2015-12-01

    Atmospheric particles in the polar regions consist mostly of sea salt aerosol (SSA). SSA plays an important role in regional climate change through influencing the surface energy balance either directly or indirectly via cloud formation. SSA irradiated by sunlight also releases very reactive halogen radicals, which control concentrations of ozone, a pollutant and greenhouse gas. However, models under-predict SSA concentrations in the Arctic during winter pointing to a missing source. It has been recently suggested that salty blowing snow above sea ice, which is evaporating, to be that source as it may produce more SSA than equivalent areas of open ocean. Participation in the 'Norwegian Young Sea Ice Cruise (N-ICE 2015)' on board the research vessel `Lance' allowed to test this hypothesis in the Arctic sea ice zone during winter. Measurements were carried out from the ship frozen into the pack ice North of 80º N during February to March 2015. Observations at ground level (0.1-2 m) and from the ship's crows nest (30 m) included number concentrations and size spectra of SSA (diameter range 0.3-10 μm) as well as snow particles (diameter range 50-500 μm). During and after blowing snow events significant SSA production was observed. In the aerosol and snow phase sulfate is fractionated with respect to sea water, which confirms sea ice surfaces and salty snow, and not the open ocean, to be the dominant source of airborne SSA. Aerosol shows depletion in bromide with respect to sea water, especially after sunrise, indicating photochemically driven release of bromine. We discuss the SSA source strength from blowing snow in light of environmental conditions (wind speed, atmospheric turbulence, temperature and snow salinity) and recommend improved model parameterisations to estimate regional aerosol production. N-ICE 2015 results are then compared to a similar study carried out previously in the Weddell Sea during the Antarctic winter.

  15. The forensically important blow fly, Chrysomya megacephala (Diptera: Calliphoridae), is more likely to walk than fly to carrion at low light levels.

    Science.gov (United States)

    Smith, Joshua L; Palermo, Nicholas A; Theobald, Jamie C; Wells, Jeffrey D

    2016-09-01

    One factor that influences estimates of time since death using entomological evidence is whether or not blow flies nocturnally oviposit. Field studies focusing on egg laying have found it occurs on an inconsistent basis. A key but poorly understood factor in nocturnal oviposition is a blow fly's ability to locate carrion under low light levels. It has been speculated that blow flies are more likely to walk than fly to carrion during the night, but this has not been empirically tested. We directly compared guided walking versus flying using infrared sensors under low light levels in laboratory conditions for Chrysomya megacephala (F.) (Diptera: Calliphoridae), a blow fly previously described to be nocturnal. We found C. megacephala is more likely to walk than fly toward carrion under low light levels (p=0.016). We did not, however, find differences between males and females for walking (p=0.48) or flying (p=0.42) despite male C. megacephala possessing eyes better suited for increased light capture. These results demonstrate the need to better understand where blow flies go at night, as bodies found within a fly's walking distance are more likely to be colonized.

  16. A Computational Investigation of the Finite-Time Blow-Up of the 3D Incompressible Euler Equations Based on the Voigt Regularization

    CERN Document Server

    Larios, Adam; Titi, Edriss S; Wingate, Beth

    2015-01-01

    We report the results of a computational investigation of two recently proved blow-up criteria for the 3D incompressible Euler equations. These criteria are based on an inviscid regularization of the Euler equations known as the 3D Euler-Voigt equations. The latter are known to be globally well-posed. Moreover, simulations of the 3D Euler-Voigt equations also require less resolution than simulations of the 3D Euler equations for fixed values of the regularization parameter $\\alpha>0$. Therefore, the new blow-up criteria allow one to gain information about possible singularity formation in the 3D Euler equations indirectly; namely, by simulating the better-behaved 3D Euler-Voigt equations. The new criteria are only known to be sufficient criteria for blow-up. Therefore, to test the robustness of the inviscid-regularization approach, we also investigate analogous criteria for blow-up of the 1D Burgers equation, where blow-up is well-known to occur.

  17. Nonlinear parabolic equations with blowing-up coefficients with respect to the unknown and with soft measure data

    Directory of Open Access Journals (Sweden)

    Khaled Zaki

    2016-12-01

    Full Text Available We establish the existence of solutions for the nonlinear parabolic problem with Dirichlet homogeneous boundary conditions, $$ \\frac{\\partial u}{\\partial t} - \\sum_{i=1}^N\\frac{\\partial}{\\partial x_i} \\Big( d_i(u\\frac{\\partial u}{\\partial x_i} \\Big =\\mu,\\quad u(t=0=u_0, $$ in a bounded domain. The coefficients $d_i(s$ are continuous on an interval $]-\\infty,m[$, there exists an index p such that $d_p(u$ blows up at a finite value m of the unknown u, and $\\mu$ is a diffuse measure.

  18. Global Existence and Blow-up of Solutions for Parabolic Systems Involving Cross-Diffusions and Nonlinear Boundary Conditions

    Institute of Scientific and Technical Information of China (English)

    Xiu Hui YANG; Fu Cai LI; Chun Hong XIE

    2005-01-01

    In this paper, we investigate the positive solutions of strongly coupled nonlinear parabolic systems with nonlinear boundary conditions:({ut-α(u,v)△u=g(u,v),vt-b(u,v)△v=h(u,v),(e)u/(e)(g)=d(u,v),(e)u/(e)(g)=f(u,v),)Under appropriate hypotheses on the functions a, b, g, h, d and f, we obtain that the solutions may exist globally or blow up in finite time by utilizing upper and lower solution techniques.

  19. Dispersive Blow-Up Ⅱ.Schr(o)dinger-Type Equations,Optical and Oceanic Rogue Waves

    Institute of Scientific and Technical Information of China (English)

    Jerry L.BONA; Jean-Claude SAUT

    2010-01-01

    Addressed here is the occurrence of point singularities which owe to the fo-cusing of short or long waves,a phenomenon labeled dispersive blow-up.The context of this investigation is linear and nonlinear,strongly dispersive equations or systems of equa-tions.The present essay deals with linear and nonlinear Schr(o)dinger equations,a class of fractional order SchrSdinger equations and the linearized water wave equations,with and without surface tension. Commentary about how the results may bear upon the formation of rogue waves in fluid and optical environments is also included.

  20. On Blowing Up the Pokies: The Pokie Lounge as a Cultural Site of Neoliberal Governmentality in Australia

    OpenAIRE

    Fiona Nicoll

    2011-01-01

    In 1999 The Whitlams, a popular ‘indie’ band named after a former Australian prime minister whose government was controversially sacked in 1975 by the Governor-General, released a single titled ‘Blow up the Pokies’. Written about a former band member’s fatal attraction to electronic gaming machines (henceforth referred to as ‘pokies’), the song was mixed by a top LA producer, a decision that its writer and The Whitlam’s front-man, Tim Freedman, ...

  1. The first debate: no knockout blows means that both campaigns\\ud still have their work cut out

    OpenAIRE

    Trubowitz, Peter

    2016-01-01

    Last night’s first presidential debate between Hillary Clinton and Donald Trump was widely\\ud anticipated as one of the most important set pieces of the campaign so far. US Centre Director,\\ud Peter Trubowitz gives his takeaways from the debate, writing that while neither candidate landed\\ud any heavy blows, Clinton won on points by controlling the tone of the debate and by putting Trump\\ud on the defensive. Both candidates’ performances will likely reinforce support from their bases, but\\ud ...

  2. SELF-SIMILAR SOLUTIONS AND BLOW-UP PHENOMENA FOR A TWO-COMPONENT SHALLOW WATER SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Shouming ZHOU; Chunlai MU; Liangchen WANG

    2013-01-01

    In this article,we consider a two-component nonlinear shallow water system,which includes the famous 2-component Camassa-Holm and Degasperis-Procesi equations as special cases.The local well-posedess for this equations is established.Some sufficient conditions for blow-up of the solutions in finite time are given.Moreover,by separation method,the self-similar solutions for the nonlinear shallow water equations are obtained,and which local or global behavior can be determined by the corresponding Emden equation.

  3. Growth rates of stratospheric HCFC-22

    Directory of Open Access Journals (Sweden)

    D. P. Moore

    2007-07-01

    Full Text Available The Michelson Interferometer for Passive Atmospheric Sounding onboard ENVISAT (MIPAS-E offers the opportunity to detect and spectrally resolve many atmospheric minor constituents affecting atmospheric chemistry. In this paper, we describe an algorithm produced to retrieve HCFC–22 profiles from MIPAS-E measurements made in 2003 and present results from this scheme between 300 and 50 mb. By comparison with ATMOS (AT–3 version 3 data, we find a mean Northern Hemisphere mid-latitude (20–50° N HCFC–22 growth rate between 1994 and 2003 of 5.4±0.7 pptv/yr in the lower stratosphere (LS and a mean LS Southern Hemisphere growth rate (60–80°S of 6.0±0.7 pptv/yr in the same period. We test the feasibility of using a global data set to estimate the chemical lifetime of HCFC–22 in the LS and we derive this for two regions; 20–50° N (259±38 years and 60–80° S (288±34 years. From these data we note a global LS lifetime of 274±25 years, significantly longer than previous estimates.

  4. 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.

  5. 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.

  6. 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.

  7. Heat pumps: which refrigerant will win?; Welche Kaeltemittel werden sich durchsetzen?

    Energy Technology Data Exchange (ETDEWEB)

    Genath, B.

    2004-07-01

    This article discusses the alternatives available to the refrigeration industry when new regulations concerning the use of hydrochlorofluorocarbons (HCFC) come into force. The alternatives include water, carbon dioxide, iso-butane and propene. Work being done in Europe and America is discussed and examples of installations using these alternative refrigerants are described. Global Warming and the persistence of the refrigerants in the atmosphere are discussed, as is their flammability. Further environmentally-relative characteristics of the various refrigerants are listed.

  8. Fabrication of a micro through-hole array by gas-blowing a PDMS-treated polyamide screen for a flexible drag-reducing skin-like device

    Science.gov (United States)

    Li, Yong; Zhou, Kai; Zhao, Xiang; Kong, Quancun

    2017-01-01

    We propose a method for fabricating a flexible skin-like device for generating and trapping micro bubbles with the aim of reducing underwater drag. This low-cost, efficient, high-pressure gas-blow method is used to fabricate a micro through-hole array in a flexible polydimethylsiloxane (PDMS) gel-based skin. The key parameters in the gas-blowing method are investigated, such as the viscosity of PDMS and the blowing pressure in order to optimize the quality of through-hole layer. Deviation of the linear dimensions of the obtained micro holes was less than 4.5%. In addition, multiphase computational fluid dynamics models were built to analyze the drag-reduction performance of bell-shaped holes made by this method. Compared with cylindrical through holes produced by molding, the drag-reduction effect of bell-shaped holes increased as much as 34%.

  9. A blow to the fly - Lucilia cuprina draft genome and transcriptome to support advances in biology and biotechnology.

    Science.gov (United States)

    Anstead, Clare A; Batterham, Philip; Korhonen, Pasi K; Young, Neil D; Hall, Ross S; Bowles, Vernon M; Richards, Stephen; Scott, Maxwell J; Gasser, Robin B

    2016-01-01

    The blow fly, Lucilia cuprina (Wiedemann, 1830) is a parasitic insect of major global economic importance. Maggots of this fly parasitize the skin of animal hosts, feed on excretions and tissues, and cause severe disease (flystrike or myiasis). Although there has been considerable research on L. cuprina over the years, little is understood about the molecular biology, biochemistry and genetics of this parasitic fly, as well as its relationship with its hosts and the disease that it causes. This situation might change with the recent report of the draft genome and transcriptome of this blow fly, which has given new and global insights into its biology, interactions with the host animal and aspects of insecticide resistance at the molecular level. This genomic resource will likely enable many fundamental and applied research areas in the future. The present article gives a background on L. cuprina and myiasis, a brief account of past and current treatment, prevention and control approaches, and provides a perspective on the impact that the L. cuprina genome should have on future research of this and related parasitic flies, and the design of new and improved interventions for myiasis.

  10. Unsteady MHD Slip Flow of a Non-Newtonian Casson Fluid due to Stretching Sheet with Suction or Blowing Effect

    Directory of Open Access Journals (Sweden)

    A Mahdy

    2016-01-01

    Full Text Available In this contribution a numerical study is carried out to analyze the effect of slip at the boundary of unsteady two-dimensional MHD flow of a non-Newtonian fluid over a stretching surface having a prescribed surface temperature in the presence of suction or blowing at the surface. Casson fluid model is used to characterize the non-Newtonian fluid behavior. With the help of similarity transformations, the governing partial differential equations corresponding to the momentum and heat transfer are reduced to a set of non-linear ordinary differential equations, which are then solved for local similar solutions using the very robust computer algebra software MATLAB. The flow features and heat transfer characteristics for different values of the governing parameters are graphically presented and discussed in detail. Comparison with available results for certain cases is excellent. The effect of increasing values of the Casson parameter is seen to suppress the velocity field. But the temperature is enhanced with increasing Casson parameter. For increasing slip parameter, velocity increases and thermal boundary layer becomes thinner in the case of suction or blowing.

  11. On Blowing Up the Pokies: The Pokie Lounge as a Cultural Site of Neoliberal Governmentality in Australia

    Directory of Open Access Journals (Sweden)

    Fiona Nicoll

    2011-03-01

    Full Text Available In 1999 The Whitlams, a popular ‘indie’ band named after a former Australian prime minister whose government was controversially sacked in 1975 by the Governor-General, released a single titled ‘Blow up the Pokies’. Written about a former band member’s fatal attraction to electronic gaming machines (henceforth referred to as ‘pokies’, the song was mixed by a top LA producer, a decision that its writer and The Whitlam’s front-man, Tim Freedman, describes as calculated to ‘get it on big, bombastic commercial radio’. The investment paid off and the song not only became a big hit for the band, it developed a legacy beyond the popular music scene, with Freedman invited to write the foreword of a ‘self-help manual for giving up gambling’ as well as appearing on public affairs television shows to discuss the issue of problem gambling. The lyrics of ‘Blow up the Pokies’ frame the central themes of this article: spaces, technologies and governmentality of gambling. It then explores what cultural articulations of resistance to the pokie lounge tell us about broader social and cultural dynamics of neoliberal governmentality in Australia.

  12. Soot blowing methods and soot steam consumption in Swedish recovery boilers; Sotningsmetoder och sotaangfoerbrukning i svenska sodapannor

    Energy Technology Data Exchange (ETDEWEB)

    Svedin, Kristoffer; Wallin, Erik; Ahlroth, Mikael

    2008-09-15

    The aim with the report was to put together a description of the current state of the sootblowing systems at Swedish recovery boilers, and to explain differences in cleanability and sootblowing efficiency. In chapter 4 a summary of new techniques and alternative soot blowing methods is found. The report is intended for persons working in the pulp industry. To facilitate the benchmarking the recovery boilers have been divided into two groups. Group A comprises recovery boilers which only have one stop per year and the remaining recovery boilers with more than one stop are classified into group B. The following conclusions, based on the recovery boiler design specifications, are of importance to achieve high boiler availability: Low furnace load; High recovery boiler, wide furnace bottom area; Modern air ports; Small or no correlation between cross pitch division in heat surfaces and cleanability could be seen. The expectation was to identify such a relation. However there are doubts on the correctness in reported data. The amount of chlorine and potassium is assumed to affect the cleanability for a few recovery boilers, but for the majority the amounts are low and most likely do not impact the operation. Because of the large impact of the recovery boilers design data (furnace area, load etc.) on the sootblowing, it has been hard to identify the relation cleanability contra sootblowing system. The relations that could be seen are: No distinction between normally designed nozzles and 'high efficiency' nozzles could be identified. The operational conditions for the different models differ a lot and the effect of nozzle type could not be distinguished. Only a minority of the soot blowing sequences are known from the study. In the recovery boilers with problematic areas improvements can be made in the soot blowing sequence. Four recovery boilers are using intelligent soot blowing of some kind. Two of these boilers have low availability and the other two have

  13. Blow-up Solutions to a Viscoelastic Fluid System and a Coupled Navier-Stokes/Phase-Field System in R2

    Institute of Scientific and Technical Information of China (English)

    ZHAO Li-Yun; GUO Bo-Ling; HUANG Hai-Yang

    2011-01-01

    @@ The explicit solutions to both the Oldroyd-B model with an infinite Weissenberg number and the coupled Navier- Stokes/phase-field system are constructed by the method of separation of variables.It is found that the solutions blow up in finite time.%The explicit solutions to both the Oldroyd-B model with an infinite Weissenberg number and the coupled Navier- Stokes/phase-Beld system are constructed by the method of separation of variables. It is found that the solutions blow up in finite time.

  14. 智能化吹气装置及其应用注意事项%Intelligent Air Blowing Device and Its Application Notes

    Institute of Scientific and Technical Information of China (English)

    齐丽华; 刘琢

    2014-01-01

    After analyzing the basic principle of air blowing device used to measure liquid level,the design structure and test results of a new intelligent air blowing device are present, it is able to adjust automatically air pressure and flow. Some notes for engineering application about it are given.%阐述吹气装置检测液位的基本原理,提出恒压恒流智能型吹气装置的设计方案和试验结果,总结吹气装置在实际工程应用中的注意事项。

  15. Solution blow spinning: parameters optimization and effects on the properties of nanofibers from poly(lactic) acid/dimethyl carbonate solutions

    Science.gov (United States)

    Solution blow spinning (SBS) is a process to produce non-woven fiber sheets with high porosity and an extremely large amount of surface area. In this study, a Box-Behnken experimental design (BBD) was used to optimize the processing parameters for the production of nanofibers from polymer solutions ...

  16. Miscibility of poly(lactic acid) and poly(ethylene oxide) solvent polymer blends and nanofibers made by solution blow spinning

    Science.gov (United States)

    The miscibility of blends of poly(lactic acid) (PLA) and poly(ethylene oxide) (PEO) was studied in polymer solutions by dilute solution viscometry and in solution blow spun nanofibers by microscopy (SEM, TEM) and by thermal and spectral analysis. Three blends of PLA and PEO were solution blended in...

  17. Blow Up of a Cycle in Lotka-Volterra Type Equations with Competition-Cooperation Terms and Quasi-Linear Systems

    CERN Document Server

    Bouse, E

    2010-01-01

    We consider systems where a cycle born via the Hopf bifurcation blows up to infinity as a parameter ranges over a finite interval. Two examples demonstrating this effect are presented: planar Lotka-Volterra type systems with a competition-cooperation term and quasi-linear higher order equations.

  18. Combining Analysis of Coupled Electrical-Thermal and BLOW-OFF Impulse Effects on Composite laminate Induced by Lightning Strike

    Science.gov (United States)

    Liu, Z. Q.; Yue, Z. F.; Wang, F. S.; Ji, Y. Y.

    2015-04-01

    A comprehensive simulation procedure combining electrical-thermal analysis and BLOW-OFF impulse (BOI) analysis was conducted to investigate lightning direct effects on damage behavior of composite. The nonlinear material model was elaborated combining the damage mechanism of composite laminate subjected to lightning strike. Results of electrical-thermal analysis indicated that temperature distribution of composite laminate is mainly affected by the electrical anisotropy because of Joule heating. By comparing results of BOI analysis with lightning test, it can be found that strain fields of analysis meet well with the damage pattern of lightning specimen. It could be concluded that the analysis procedure is suitable for modeling damage of composite due to lighting strike, and results of logarithmic strain field can be used to help estimate the zone which need to be repaired for composite.

  19. Exponential energy decay and blow-up of solutions for a system of nonlinear viscoelastic wave equations with strong damping

    Directory of Open Access Journals (Sweden)

    Liang Fei

    2011-01-01

    Full Text Available Abstract In this paper, we consider the system of nonlinear viscoelastic equations u t t - Δ u + ∫ 0 t g 1 ( t - τ Δ u ( τ d τ - Δ u t = f 1 ( u , v , ( x , t ∈ Ω × ( 0 , T , v t t - Δ v + ∫ 0 t g 2 ( t - τ Δ v ( τ d τ - Δ v t = f 2 ( u , v , ( x , t ∈ Ω × ( 0 , T with initial and Dirichlet boundary conditions. We prove that, under suitable assumptions on the functions gi , fi (i = 1, 2 and certain initial data in the stable set, the decay rate of the solution energy is exponential. Conversely, for certain initial data in the unstable set, there are solutions with positive initial energy that blow up in finite time. 2000 Mathematics Subject Classifications: 35L05; 35L55; 35L70.

  20. Engineering Education for All University First Year Students Using Playing in the Sand and Blowing Soap Bubbles

    Science.gov (United States)

    Tsunekawa, Masami; Hiroyoshi, Naoki; Ito, Mayumi; Hirajima, Tsuyoshi

    Hokkaido University holds first year student seminars for promoting student ability in communication, presentation, design, and creativity. The authors have held this seminar to students of all faculties, where the research topics were determined by the students themselves from the phenomena or questions relating to children‧s games such as playing in the sand and blowing soap bubbles. Then, they planned experimental procedures, discussed, summarized, and presented the results with minimal advice from teachers. After the student presentations the teachers introduced the techniques and equipments related to the topics, which are used in industrial plants. The final questionnaire showed that this type of lecture is very effective to promote student motivation and ability.

  1. Excitation of Large Transverse Beam Oscillations without Emittance Blow-up using the AC-Dipole Principle

    CERN Document Server

    Berrig, O E; Jones, R; Koopman, J; Koutchouk, Jean-Pierre; Schmickler, Hermann; Schmidt, F

    2001-01-01

    The so-called "AC-Dipole" principle allows the excitation of transverse oscillations to large (several sigma) excursions without emittance blow-up. The idea was originally proposed and tested at BNL for resonance crossing with polarized beams, using an orbit corrector dipole with an excitation frequency close to the betatron tune, hence "AC-Dipole". This method of beam excitation has several potential applications in teh LHC, such as phase advance and beta-measurements, dynamic aperture studies and the investigation of resonance strengths. The technique was recently tested in the CERN SPS using the transverse damper as an "AC-Dipole" providing the fixed frequency excitation. Results from this experiment are presented, along with an explanation of the underlying principle.

  2. An Accurate Simulation Of Thermoforming And Blow-Molding Processes Using The Space Fiber Rotation (SFR) Concept

    Science.gov (United States)

    Ghomari, T.; Ayad, R.; Talbi, N.

    2007-05-01

    This work deals with a non-linear formulation of an axisymmetric hyperelastic solid model for thermoforming and blow-molding processes. It's based on a new kinematic concept labeled SFR (Space Fiber Rotation). The SFR-Axi element model uses a kinematic motion of a space linear fiber in order to obtain more accurate displacement field, without increasing the number of nodes. It improves in a significant way the precision of the linear element Q4 indeed. The corresponding numerical results are comparable and even better, in term of time CPU, with those of the 8-nodes higher order element Q8. A hyperelastic behavior law based on Mooney-Rivlin model has been implemented to allow the model better simulations of forming processes hollow plastic bodies. The numerical results, very promising, are given with considering or not the contact between the polymer.

  3. Blow Flies from Forest Fragments Embedded in Different Land Uses: Implications for Selecting Indicators in Forensic Entomology.

    Science.gov (United States)

    de Souza, Mirian S; Pepinelli, Mateus; de Almeida, Eduardo C; Ochoa-Quintero, Jose M; Roque, Fabio O

    2016-01-01

    Given the general expectation that forest loss can alter biodiversity patterns, we hypothesize that blow fly species abundances differ in a gradient of native vegetation cover. This study was conducted in 17 fragments across different landscapes in central Brazil. Different land cover type proportions were used to represent landscape structure. In total, 2334 specimens of nine species of Calliphoridae were collected. We used principal component analysis (PCA) to reduce dimensionality and multicollinearity of the landscape data. The first component explained 70%, and it represented a gradient of forest-pasture land uses. Alien species showed a wide distribution in different fragments with no clear relationship between the abundance values and the scores of PCA axes, whereas native species occurred only in areas with a predominance of forest cover. Our study revealed that certain native species may be sensitive to forest loss at the landscape scale, and they represent a bioindicator in forensic entomology.

  4. Active control of vortex-induced vibrations of a circular cylinder using windward-suction- leeward-blowing actuation

    Science.gov (United States)

    Wang, Chenglei; Tang, Hui; Yu, Simon C. M.; Duan, Fei

    2016-05-01

    This paper studies the control of two-dimensional vortex-induced vibrations (VIVs) of a single circular cylinder at a Reynolds number of 100 using a novel windward-suction-leeward-blowing (WSLB) concept. A lattice Boltzmann method based numerical framework is adopted for this study. Both open-loop and closed-loop controls are implemented. In the open-loop control, three types of actuation arrangements, including the pure suction on the windward side of the cylinder, the pure blowing on the leeward side, and the general WSLB on both sides, are implemented and compared. It is found that the general WSLB is the most effective, whereas the pure suction is the least effective. In the closed-loop control, the proportional (P), integral (I), and proportional-integral (PI) control schemes are applied to adjust the WSLB velocities according to the flow information obtained from a sensor. The effects of four key control parameters including the proportional gain constant, the integral gain constant, the length of data history used for the feedback, and the location of the sensor are investigated. It is found that the use of only P control fails to completely suppress the VIV, the use of only I control can achieve the complete suppression, and the PI control performs the best in terms of both the control effectiveness and efficiency. In the PI control, there exists an optimal length of data history for the feedback, at which the VIV control is the most efficient. There also exist the minimum required WSLB velocities for the VIV suppression, independent of the control schemes. Moreover, it is found that the VIV control is independent of the sensor location.

  5. Dissolved methane plume mapping using Membrane Inlet Mass-Spectrometry (MIMS) at a blow out site in the North Sea

    Science.gov (United States)

    Sommer, S.; Schmidt, M.; Linke, P.

    2012-04-01

    A blow out site in the North Sea (well 22/4-b, UK EEZ) in a water depth of 83 m, served as a test area to demonstrate MIMS as a powerful tool for the continuous measurement of dissolved methane simultaneously to the partial pressure of carbon dioxide, nitrogen and oxygen as well as other gases. A pump-CTD arrangement was used to generate a continuous water stream through a 2.5 cm thick tube to the ship laboratory and was analyzed using a membrane inlet quadrupole mass spectrometer (GAM 200, InProcessInstruments). The pump-CTD was further equipped with calibrated HydroC CH4/CO2 sensors. The MIMS measurements were conducted under fully controlled temperature conditions and were calibrated for CH4, N2, O2, and pCO2. The pump-CTD arrangement was towed along transects across the blow out and dissolved gas concentrations as well as physical water column data were synchronized and geo-referenced. The transects were repeated in three different depth layers, including a bottom layer of ~ 2 m above the sea floor, 60 m above the sea floor just below the thermocline and a third plane in 10 m water depth. During the tows water samples were taken for later onboard methane analysis and cross-calibration with the MIMS and HydroC data. After data selection under consideration of the tidal regime lateral and vertical plume dimensions of dissolved methane were constructed. Dissolved methane concentrations ranged between background and up to about 18µM. Below the thermocline, which represents an effective barrier for the vertical distribution of dissolved methane, methane distinctively spreads laterally. Only at locations were the gas bubble stream and concurrently advected water from below the thermocline reaches the sea surface enhanced methane emission into the atmosphere took place.

  6. Development of fine-celled bio-fiber composite foams using physical blowing agents and nano-particles

    Science.gov (United States)

    Guo, Gangjian

    As one of eco-friendly bio-fibers, wood-fiber has been incorporated in plastics to make wood-fiber/plastic composites (WPC) with an increased stiffness, durability and lowered cost. However, these improvements are usually accompanied by loss in the ductility and impact strength of the composites. These shortcomings can be significantly improved by incorporating a fine-cell foam structure in the composites. This thesis presents the development of the foaming technology for the manufacture of fine-cell WPC foams with environmentally benign physical blowing agents (PBAs), and focuses on the elucidation of the fundamental foaming mechanisms and the related issues involved. One critical issue comes from the volatiles evolved from the wood-fiber during high temperature processing. The volatiles, as a blowing agent, can contribute to the foaming process. However, they lead to gross deterioration of the cell structure of WPC foams. The presence of volatiles makes foaming of WPC "a poorly understood black art". With the use of PBAs, a strategy of lowering processing temperature becomes feasible, to suppress the generation of volatiles. A series of PBA-based experiments were designed using a statistical design of experiments (DOE) technique, and were performed to establish the relationship of processing and material variables with the structure of WPC foams. Fundamental foaming behaviors for two different PBAs and two different polymer systems were identified. WPC foams with a fine-cell morphology and a desired density were successfully obtained at the optimized conditions. Another limitation for the wider application of WPC is their flammability. Innovative use of a small amount of nano-clay in WPC significantly improved the flame-retarding property of WPC, and the key issue was to achieve a high degree of exfoliation of nano-particles in the polymer matrix, to achieve a desired flammability reduction. The synergistic effects of nano-particles in foaming of WPC were

  7. Technology for Smelting V-N Micro-alloyed Steel by Blowing Nitrogen%气体增氮法冶炼钒氮微合金钢

    Institute of Scientific and Technical Information of China (English)

    康伟; 康磊; 赵坦; 廖相巍

    2014-01-01

    从理论上分析了钢液增氮的热力学、动力学影响因素,进行了BOF+RH双联吹氮冶炼钒氮钢试验。结果表明,转炉底吹、RH喷吹均能有效增加钢液氮含量。 RH真空度两段式控制既能满足控氢要求又能实现钢液搬出时较高的氮含量。 BOF+RH双联吹氮气工艺可以不加含氮合金冶炼钒氮微合金钢。%The thermodynamic and dynamic influence factors for increasing the content of ni-trogen in molten steel are theoretically analyzed and the experiment for the smelting V-N contain-ing steel by blowing nitrogen into both BOF and RH is carried out. The results show that the con-tent of nitrogen in molten steel can be effectively increased by converter bottom blowing and RH blowing. With its characteristics of the RH blowing the two-stage control technology for RH vacu-um degree can meet the requirement for controlling the content of hydrogen and also the molten steel with relative high content of nitrogen can be available when tapping. V-N micro-alloyed steel can be smelted without adding the nitrogen-containing alloy by using BOF and RH duplex nitro-gen-blowing process.

  8. TEWI Analysis: Its Utility, Its Shortcomings, and Its Results

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, V.D.; Fischer, S.K.; Sand, J.R.

    1999-09-13

    The past decade has been a challenging time for the refrigeration and air conditioning industry worldwide. Provisions of the Montreal Protocol and its amendments require the phaseout of chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) compounds that have been used extensively as insulating foam blowing agents and refrigerants in refrigeration systems, heat pumps, and air conditioners. In response, hydrofluorocarbon (HFC) compounds were proposed, developed, and are starting to be used as the primary alternatives to CFCs and HCFCs. However, in 1997 under the Kyoto Protocol, industrialized nations have agreed to roll back emissions of HCFCs, carbon dioxide (CO*), and four other greenhouse gases which threaten to cause excessive global warming. The US. Department of Energy and the Alternative Fluorocarbon Environmental Acceptability Study (AFEAS) jointly sponsored research projects to identify the major applications of CFCs, HCFCs, and HFCs and to examine the impacts of these compounds and the energy use of applications employing these compounds on global warming. The five major uses of fluorocarbons based on sales were automobile air conditioning, supermarket refrigeration, unitary heat pumps and air conditioning, chillers for cooling large office buildings, and household refrigeration. Almost all of the refrigerants used in these applications are global warming gases, and if the refrigerant leaks out of the system during operation, is lost during maintenance or is not recovered when the system is scraped, it contributes to global warming. But, it is also true that the energy consumed by refrigeration and air conditioning systems, in the form of electricity or the direct combustion of fossil fuel, results in the release of CO*, the primary cause of atmospheric global warming.

  9. Driver model used in vehicle tire blow-out simulation%用于爆胎车辆仿真的驾驶员模型

    Institute of Scientific and Technical Information of China (English)

    刘涛; 郭孔辉

    2012-01-01

    分析了驾驶员模型在汽车爆胎仿真应用中存在的问题及爆胎后车辆响应特性的变化,指出爆胎后车辆响应特性发生改变是导致驾驶员模型不能控制爆胎后汽车回到原路径的根本原因。建立了考虑爆胎后车辆左、右转向特性不对称的驾驶员模型,并进行了仿真。最后在原驾驶员模型中加入状态参考器,并对不同车速下的状态参考器参数进行辨识。解决了驾驶员模型在汽车爆胎仿真中的应用问题,为进一步研究汽车爆胎后驾驶员的操作规律及爆胎后汽车的稳定性控制提供了参考。%The problem of application of the driver model in the vehicle tire blow-out simulation and the changes of the vehicle response behavior after the tire blow-out were analyzed,and it was found that vehicle response changes after the tire blow-out are the main cause leading to the problem that the driver model can not drive the vehicle back to the original trajectory.A new driver model considering the fact that the vehicle is characterized by unsymmetric leftward and rightward turning after the tire blow-out was built and its simulation was performed.A vehicle state reference module was embedded in the original driver model and its parameters were identified under different driving speeds.Thus the problem of application of the driver model in the vehicle tire blow-out was solved,providing a reference for the study of driver operation behavior and stability control of the vehicle after tire blow-out.

  10. Stefan blowing effects on MHD bioconvection flow of a nanofluid in the presence of gyrotactic microorganisms with active and passive nanoparticles flux

    Science.gov (United States)

    Giri, Shib Sankar; Das, Kalidas; Kundu, Prabir Kumar

    2017-02-01

    The present paper investigates the effect of Stefan blowing on the hydro-magnetic bioconvection of a water-based nanofluid flow containing gyrotactic microorganisms through a permeable surface. Also we studied both actively and passively the controlled flux of nanoparticles and the effect of a surface slip at the wall. We adopt a similarity approach to reduce the leading partial differential equations into ordinary differential equations along with two separate boundary conditions (active and passive) and solve the resulting equations numerically by employing the RK-4 method through the shooting technique to perform the flow analysis. Discussions on the effect of emerging flow parameter on the flow characteristic are made properly through graphs and charts. We observed that the effects of the traditional Lewis number and suction/blowing parameter on temperature distribution and microorganism concentration are converse to each other. A fair result comparison of the present paper with formerly obtained results is given.

  11. 三维等熵欧拉方程组解的爆破%Blow Up of Isentropic Euler Equations in Three Dimensions

    Institute of Scientific and Technical Information of China (English)

    朱旭生; 艾利娜; 汤传扬

    2015-01-01

    The blow up of the initial value problems of classical solutions of the isentropic Euler equations with damping term in three dimensions was investigated .Under the condition of M(0) <0 , if the initial momentum of cer-tain functions is large enough , then it follows that the classical solution must blow up in a limited time .%研究了带阻尼项的三维等熵欧拉方程组初值问题经典解的爆破。在M(0)<0条件下,若初始动量的某些泛函足够大时,得到了其经典解在有限时间内必定发生爆破的结论。

  12. Keys to the blow flies of Taiwan, with a checklist of recorded species and the description of a new species of Paradichosia Senior-White (Diptera, Calliphoridae

    Directory of Open Access Journals (Sweden)

    Shih-Tsai Yang

    2014-08-01

    Full Text Available Blow flies (Diptera: Calliphoridae show a great diversity in behavior and ecology, play important roles in ecosystems, and have medical and forensic importance to humans. Despite this, the taxonomy and classification of Taiwan's Calliphoridae have rarely been studied. In this study, specimens of Taiwanese calliphorids were collected and carefully studied, and all 76 species recorded in Taiwan are listed following the identification keys. Dichotomous keys to all subfamilies, tribes, genera, and species of blow flies recorded in Taiwan are provided, including 16 species that are newly recorded from Taiwan. In addition, one new species of the genus Paradichosia Senior-White is described and illustrated. We also discuss the morphological differences between the specimens of Silbomyia hoeneana Enderlein collected from China and Taiwan, a species that has only been found previously in Southern China.

  13. On the blow-up criterion of strong solutions for the MHD equations with the Hall and ion-slip effects in R3}

    Science.gov (United States)

    Gala, Sadek; Ragusa, Maria Alessandra

    2016-04-01

    In this paper, we establish a blow-up criterion of strong solutions to the 3D incompressible magnetohydrodynamics equations including two nonlinear extra terms: the Hall term (quadratic with respect to the magnetic field) and the ion-slip term (cubic with respect to the magnetic field). This is an improvement of the recent results given by Fan et al. (Z Angew Math Phys, 2015).

  14. The BLOW-3A: A theoretical model to describe transient two phase flow conditions in Liquid Metal Fast Breeder Reactor (LMFBR) coolant channels

    Science.gov (United States)

    Bottoni, M.; Struwe, D.

    The theoretical background of the BLOW-3A program is reported, including the basic equations used to determine temperature fields in the fuel, clad, coolant and structure material as well as the coolant dynamics in single and two-phase flow conditions. The two-phase flow model assumes an annular flow regime. Special aspects to calculate two-phase pressure drops for these conditions are discussed. Examples of the experimental validation of the program are given.

  15. Injection of new psychoactive substance snow blow associated with recently acquired HIV infections among homeless people who inject drugs in Dublin, Ireland, 2015.

    LENUS (Irish Health Repository)

    Giese, Coralie

    2015-10-08

    In February 2015, an outbreak of recently acquired HIV infections among people who inject drugs (PWID) was identified in Dublin, following similar outbreaks in Greece and Romania in 2011. We compared drug and risk behaviours among 15 HIV cases and 39 controls. Injecting a synthetic cathinone, snow blow, was associated with recent HIV infection (AOR: 49; p = 0.003). Prevention and control efforts are underway among PWID in Dublin, but may also be needed elsewhere in Europe.

  16. Get the most out of blow hormones: validation of sampling materials, field storage and extraction techniques for whale respiratory vapour samples.

    Science.gov (United States)

    Burgess, Elizabeth A; Hunt, Kathleen E; Kraus, Scott D; Rolland, Rosalind M

    2016-01-01

    Studies are progressively showing that vital physiological data may be contained in the respiratory vapour (blow) of cetaceans. Nonetheless, fundamental methodological issues need to be addressed before hormone analysis of blow can become a reliable technique. In this study, we performed controlled experiments in a laboratory setting, using known doses of pure parent hormones, to validate several technical factors that may play a crucial role in hormone analyses. We evaluated the following factors: (i) practical field storage of samples on small boats during daylong trips; (ii) efficiency of hormone extraction methods; and (iii) assay interference of different sampler types (i.e. veil nylon, nitex nylon mesh and polystyrene dish). Sampling materials were dosed with mock blow samples of known mixed hormone concentrations (progesterone, 17β-estradiol, testosterone, cortisol, aldosterone and triiodothyronine), designed to mimic endocrine profiles characteristic of pregnant females, adult males, an adrenal glucocorticoid response or a zero-hormone control (distilled H2O). Results showed that storage of samples in a cooler on ice preserved hormone integrity for at least 6 h (P = 0.18). All sampling materials and extraction methods yielded the correct relative patterns for all six hormones. However, veil and nitex mesh produced detectable assay interference (mean 0.22 ± 0.04 and 0.18 ± 0.03 ng/ml, respectively), possibly caused by some nylon-based component affecting antibody binding. Polystyrene dishes were the most efficacious sampler for accuracy and precision (P samples obtained from field collections of whale blow.

  17. 清梳联设备状态维修管理体会%Experience of Blowing-carding Unit State Maintenance and Management

    Institute of Scientific and Technical Information of China (English)

    潘荣昌; 李海霞; 徐林岚

    2011-01-01

    探讨清梳联设备进行状态维修的管理要点.针对当前清梳联设备的性能特点,在设备管理方面采取状态维修与周期保养揩检相结合,以状态维修为主的包机制管理模式,通过加强员工队伍建设、建立健全设备维护保养制度、细化清梳联设备的维修保养周期和范围、充分发挥试验仪器和测试仪表的作用等手段,充分调动了人员积极性,降低了机物料消耗,提高了设备的运行质量,使清梳联设备的性能得到了充分发挥.%Key points of blowing-carding unit state maintenance and management were discussed. According to blowing-carding unit characteristics, periodic maintenance and state maintenance were combined. Contract management mode was adopted. Staff structure was enhanced, equipment maintenance system was established, maintenance periodic and range of blowing-carding unit were subdivided, function of test instruments were used fully, staff positive attitude were mobilized fully, machine material consumption were reduced, machine operational quality were improved, finally performance of blowing-carding unit were used fully.

  18. On Blow-up of Globle Solutions for Interaction Waves%相互作用波动方程组整体解的爆破性

    Institute of Scientific and Technical Information of China (English)

    侯慎勇

    2003-01-01

    利用能量守恒定律和积分不等式技巧,讨论了相互作用波动方程组utt-Δ(u+v)=f(u,v), vtt-Δ(u+v)=g(u,v), t>0, x∈Ω整体解的爆破性,得到了关于系统爆破性的一些性质,并给出了blow-up时间的一个界.

  19. FMRFamide-Like Immunoreactivity in the Central Nervous System and Alimentary Tract of the Non-Hematophagous Blow Fly, Phormia regina, and the Hematophagous Horse Fly, Tabanus nigrovittatus

    OpenAIRE

    Haselton, Aaron T.; Yin, Chih-Ming; Stoffolano, John G.

    2008-01-01

    FMRFamide-related peptides (FaRPs) are a diverse and physiologically important class of neuropepeptides in the metazoa. In insects, FaRPs function as brain-gut neuropeptides and have been immunolocalized throughout the nervous system and alimentary tract where they have been shown to affect feeding behavior. The occurrence of FMRFamide-like immunoreactivity (FLI) was examined in the central nervous system and alimentary tract of non-hematophagous blow fly, Phormia regina Meigen (Diptera: Call...

  20. Identification of forensically important blow fly species (Diptera: Calliphoridae) in China by mitochondrial cytochrome oxidase I gene differentiation

    Institute of Scientific and Technical Information of China (English)

    Qin-Lai Liu; Li Yang; Kun-Lu Wu; Ling-mei Lan; Jiang-Feng Wang; Yao-Qing Chen; Ji-Feng Cai; Yun-Feng Chang; Yan Gu; Ya-Dong Guo; Xing-Hua Wang; Ji-FangWeng; Ming Zhong; Xiang Wang

    2011-01-01

    Unambiguous and rapid sarcosaphagous insect species identification is an essential requirement for forensic investigations. Although some insect species are difficult to classify morphologically, they can be effectively identified using molecular methods based on similarity with abundant authenticated reference DNA sequences in local databases.However, local databases are still relatively incomplete in China because of the large land area with distinct regional conditions. In this study, 75 forensically important blow flies were collected from 23 locations in 16 Chinese provinces, and a 278-bp segment of the cytochrome oxidase subunit Ⅰ gene of all specimens was successfully sequenced. Phylogenetic analysis of the sequenced segments showed that all Calliphorid specimens were properly assigned into nine species with relatively strong supporting values, thus indicating that the 278-bp cytochrome oxidase subunit one region is suitable for identification of Calliphorid species. The clear difference between intraspecific threshold and interspecific divergence confirmed the potential of this region for Calliphorid species identification,especially for distinguishing between morphologically similar species. Intraspecific geographic variations were observed in Lucilia sericata (Meigen, 1826) and Lucilia caesar (Linnaeus, 1758).

  1. Impurities removal by laser blow-off from in-vacuum optical surfaces on RFX-mod experiment.

    Science.gov (United States)

    Alfier, A; Barison, S; Fassina, A; Fiameni, S; Giudicotti, L; Pasqualotto, R; Cervaro, V; Lotto, L

    2010-12-01

    An in situ window cleaning system by laser blow-off through optical fiber has been developed on the basis of a feasibility study previously presented. The beam generated by a Q-switched Nd:YAG laser is launched in a vacuum box into a high damage threshold optical fiber through a lens. The fiber output is focused on the impurities-coated surface of a vacuum window exposed to the plasma of the RFX-mod experiment, and it is remotely controlled with an xy motion system to scan the entire surface. We first investigate the energy density threshold necessary to ablate the deposited impurity substrate on removed dirty windows: above threshold, a single laser pulse recovers ∼95% of the window transmission before its exposure to the plasma, while below it the efficiency of the cleaning process is too poor. The system so conceived was then used to clean the three collection windows of the Main Thomson scattering diagnostic on RFX-mod. We also present results obtained applying the same technique to the SiO-protected Al mirror used for the Z(eff) diagnostic: an energy threshold for efficient impurity removal without mirror damage is first identified, then ablation tests are executed and analyzed in terms of recovered reflectivity. The SIMS technique is used both with windows and mirror to study the composition of surfaces before and after the ablation.

  2. Application of high pressure processing for controlling Clostridium tyrobutyricum and late blowing defect on semi-hard cheese.

    Science.gov (United States)

    Ávila, Marta; Gómez-Torres, Natalia; Delgado, David; Gaya, Pilar; Garde, Sonia

    2016-12-01

    In this study we evaluated the application of different high pressure (HP) treatments (200-500 MPa at 14 °C for 10 min) to industrial sized semi-hard cheeses on day 7, with the aim of controlling two Clostridium tyrobutyricum strains causing butyric acid fermentation and cheese late blowing defect (LBD). Clostridium metabolism and LBD appearance in cheeses were monitored by sensory (cheese swelling, cracks/splits, off-odours) and instrumental analyses (organic acids by HPLC and volatile compounds by SPME/GC-MS) after 60 days. Cheeses with clostridial spores HP-untreated and HP-treated at 200 MPa showed visible LBD symptoms, lower concentrations of lactic, citric and acetic acids, and higher levels of pyruvic, propionic and butyric acids and of 1-butanol, ethyl and methyl butanoate, and ethyl pentanoate than cheeses without spores. However, cheeses with clostridial spores and HP-treated at ≥ 300 MPa did not show LBD symptoms and their organic acids and volatile compounds profiles were comparable to those of their respective HP-treated control cheeses, despite HP treatments caused a low spore reduction. A decrease in C. tyrobutyricum spore counts was observed after curd pressing, which seems to indicate an early spore germination, suggesting that HP treatments ≥300 MPa were able to inactivate the emerged C. tyrobutyricum vegetative cells and, thereby, prevent LBD.

  3. Global Existence and Finite Time Blow-Up for Critical Patlak-Keller-Segel Models with Inhomogeneous Diffusion

    CERN Document Server

    Bedrossian, Jacob

    2011-01-01

    The $L^1$-critical parabolic-elliptic Patlak-Keller-Segel system is a classical model of chemotactic aggregation in micro-organisms well-known to have critical mass phenomena. In this paper we study this critical mass phenomenon in the context of Patlak-Keller-Segel models with spatially varying diffusivity and decay rate of the chemo-attractant. The primary tool for the proof of global existence below the critical mass is the use of pseudo-differential operators to precisely evaluate the leading order quadratic portion of the potential energy (interaction energy). Under the assumption of radial symmetry, blow-up is proved above critical mass using a maximum-principle type argument based on comparing the mass distribution of solutions to a barrier consisting of the unique stationary solutions of the scale-invariant PKS. Although effective where standard Virial methods do not apply, this method seems to be dependent on the assumption of radial symmetry. For technical reasons we work in dimensions three and hig...

  4. A melamine-assisted chemical blowing synthesis of N-doped activated carbon sheets for supercapacitor application

    Science.gov (United States)

    Wang, Yiliang; Xuan, Huaqing; Lin, Gaoxin; Wang, Fan; Chen, Zhi; Dong, Xiaoping

    2016-07-01

    N-doped activated carbon sheets (NACS) have been successfully synthesized using glucose as carbon source via melamine-assisted chemical blowing and sequent KOH-activation method. The obtained carbon material possesses a sheet-like morphology with ultrathin thickness, hierarchical micro/mesoporous structure, high specific surface area (up to 1997.5 m2 g-1) and high pore volume (0.94 cm3 g-1). Besides, NACS material with a nitrogen content of 3.06 wt% presents a maximum specific capacitance of 312 F g-1 at a current density of 0.5 A g-1 in 6 M KOH aqueous electrolyte due to the cocontribution of double layer capacitance and pseudocapacitance. It also displays good rate performance (246 F g-1 at 30 A g-1) and cycle stability (∼91.3% retention after 4000 galvanostatic charge-discharge cycles). The assembled NACS-based symmetric capacitor exhibits a maximum energy density of 20.2 Wh kg-1 at a power density of 448 W kg-1 within a voltage range of 0-1.8 V in 0.5 M Na2SO4 aqueous electrolyte. Thus, the unique porous sheet structure and nitrogen-doping characteristic endue the electrode material a potential application for high-performance supercapacitors.

  5. Direct Blow-Spinning of Nanofibers on a Window Screen for Highly Efficient PM2.5 Removal.

    Science.gov (United States)

    Khalid, Bilal; Bai, Xiaopeng; Wei, Hehe; Huang, Ya; Wu, Hui; Cui, Yi

    2017-02-08

    Particulate matter (PM) pollution has caused many serious public health issues. Whereas indoor air protection usually relies on expensive and energy-consuming filtering devices, direct PM filtration by window screens has attracted increasing attention. Recently, electrospun polymer nanofiber networks have been developed as transparent filters for highly efficient PM2.5 removal; however, it remains challenging to uniformly coat the nanofibers on window screens on a large scale and with low cost. Here, we report a blow-spinning technique that is fast, efficient, and free of high voltages for the large-scale direct coating of nanofibers onto window screens for indoor PM pollution protection. We have achieved a transparent air filter of 80% optical transparency with >99% standard removal efficiency level for PM2.5. A test on a real window (1 m × 2 m) in Beijing has proven that the nanofiber transparent air filter acquires excellent PM2.5 removal efficiency of 90.6% over 12 h under extremely hazy air conditions (PM2.5 mass concentration > 708 μg/m(3)). Moreover, we show that the nanofibers can be readily coated on the window screen for pollution protection and can be easily removed by wiping the screen after hazardous days.

  6. Poly(l-lactic acid) and polyurethane nanofibers fabricated by solution blow spinning as potential substrates for cardiac cell culture.

    Science.gov (United States)

    Tomecka, Ewelina; Wojasinski, Michal; Jastrzebska, Elzbieta; Chudy, Michal; Ciach, Tomasz; Brzozka, Zbigniew

    2017-06-01

    This paper presents a comparison and evaluation of cardiac cell proliferation on poly(l-lactic acid) (PLLA) and polyurethane (PU) nanofibrous mats fabricated by solution blow spinning (SBS). Three different cardiac cell lines: rat cardiomyoblasts (H9C2 line), human (HCM) and rat cardiomyocytes (RCM) were used for experiments. Cell morphology, orientation and proliferation were investigated on non-modified and protein-modified (fibronectin, collagen, gelatin, laminin, poly-l-lysine) surfaces of both types of nanofibers. Obtained results of cell culture on nanofibers surfaces were compared to the results of cell culture on polystyrene (PS) surfaces modified in the same way. The results indicated that in most cases polymeric nanofibers (PLLA and PU) are better substrates for cardiac cell culture than PS surfaces. All types of investigated cells, cultured on nanofibers (PLLA and PU), had more elongated shape than cells cultured on PS surfaces. Moreover, cells were arranged in parallel to each other, according to fibers orientation. Additionally, it was shown that the protein modifications of investigated surfaces influenced on cell proliferation. Therefore, we suggest that the cardiac cell culture on nanofibrous mats fabricated by SBS could be more advanced experimental in vitro model for studies on the effect of various cardiac drugs than traditional culture on PS surface. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Alimentary Canal of the Adult Blow Fly, Chrysomya megacephala (F. (Diptera: Calliphoridae—Part I: Ultrastructure of Salivary Glands

    Directory of Open Access Journals (Sweden)

    Worachote Boonsriwong

    2012-01-01

    Full Text Available The salivary gland ultrastructure of the adult male blow fly, Chrysomya megacephala (F. (Diptera: Calliphoridae, was investigated at the ultrastructural level using light microscopy (LM, scanning electron microscopy (SEM, and transmission electron microscopy (TEM. The salivary glands are paired structures composed of a single median deferent duct bifurcated into two long, narrow efferent ducts connected to the coiled tubular glands. The SEM image of the gland surface revealed that the basal lamina is relatively smooth in general, but the whole surface appeared as a trace of rough swollen insertion by intense tracheal ramification. Ultrastructurally, the salivary gland is enclosed within the basal lamina, and interdigitation cytoplasmic extensions were apparent between the adjacent gland cells. The basement membrane appeared infoldings that is similar to the complex of the labyrinth channel. The cytoplasm characteristic of the gland revealed high activity, based on the abundance of noticeable secretory granules, either singly or in an aggregated reservoir. In addition, mitochondria were found to intersperse among rich parallel of arrays rough endoplasmic reticulum. Thick cuticle, which was well-delineated and electron dense, apically lined the gland compartments, with discontinuity of the double-layer cuticle revealing a trace of secretion discharged into the lumen. Gross anatomy of the adult salivary gland was markedly different from that of the third instar of the same species, and structural dissimilarity is discussed briefly.

  8. Effects of 5,7-dihydroxytriptamine (5,7-DHT on circadian locomotor activity of the blow fly, Calliphora vicina

    Directory of Open Access Journals (Sweden)

    Bronislaw Cymborowski

    2003-05-01

    Full Text Available The biogenic amine serotonin (5-HT is a neuromodulator in both vertebrates and invertebrates. It has been shown that serotonin, apart from its distinct effects on behavior, also plays a morphoregulatory role during the ontogeny of the insect's nervous system. The role of serotonin in modulating circadian locomotor activity of the blow fly, Calliphora vicina was explored. Injection of a specific neurotoxin, 5,7-dihydroxytryptamine (5,7-DHT, into the hemolymph appeared to significantly reduced the level of locomotor activity and lengthened the period (tau of circadian rhythmicity. After drug injection in constant darkness flies continued with their free-running rhythm of a locomotor activity, depending on the time of 5,7-DHT injection. This compound causes phase delay when administered in the early subjective day, and phase advance in the late subjective day. This effect is the opposite of the phase response curve obtained for 5-HT injections. This suggests that 5-HT might act as an entraining agent via the output pathway by feedback to clock neurons in the brain. Some of the injected insects regained their normal level of activity after a few days. These findings suggest a potential role for serotonin as modulator of circadian rhythms in insect including regulation of the level of locomotor activity.

  9. L-Type Calcium Channels Do Not Play a Critical Role in Chest Blow Induced Ventricular Fibrillation: Commotio Cordis

    Directory of Open Access Journals (Sweden)

    Christopher Madias

    2016-01-01

    Full Text Available Background. In a commotio cordis swine model, ventricular fibrillation (VF can be induced by a ball blow to the chest believed secondary to activation of mechanosensitive ion channels. The purpose of the current study is to evaluate whether stretch induced activation of the L-type calcium channel may cause intracellular calcium overload and underlie the VF in commotio cordis. Method and Results. Anesthetized juvenile swine received 6 chest wall strikes with a 17.9 m/s lacrosse ball timed to the vulnerable period for VF induction. Animals were randomized to IV verapamil (n=6 or placebo (n=6. There was no difference in the observed frequency of VF between verapamil (19/26: 73% and placebo (20/36: 56% treated animals (p=0.16. There was also no significant difference in the combined endpoint of VF or nonsustained VF (21/26: 81% in verapamil versus 24/36: 67% in controls, p=0.22. Conclusions. In this experimental model of commotio cordis, verapamil did not prevent VF induction. Thus, in commotio cordis it is unlikely that stretch activation of the L-type calcium channel with resultant intracellular calcium overload plays a prominent role.

  10. Sodium hydrogen carbonate as an alternative blowing agent in the preparation of palm-based polyurethane foam

    Science.gov (United States)

    Shakir, Amira Shakim Abdul; Badri, Khairiah Haji; Hua, Chia Chin

    2016-11-01

    An environmental-friendly blowing agent has been used to fabricate flexible polyurethane (PU) foam. Polyurethane foam was prepared from palm kernel oil-based monoester polyol (PKO-p) via prepolymerization method. Acetone has been used as solvent in this study. The developed polyurethane foam was characterized using tensile, differential scanning calorimetry analysis (DSC), thermogravimetric analysis (TGA), optical microscope and drop shape analyzer. The mechanical properties of the PU-reference (PU-R) and PU-NaHCO3 foam was analyzed by tensile using ASTM D 3574-01. From the results, the elongation of PU- NaHCO3 shows reduction to 26.3 % compared to PU-R. The DSC showed two glass transition temperatures in all samples that belonged to the PU-R and PU-NaHCO3. TGA revealed that the incorporation of sodium hydrogen carbonate into the PU system did not show significant difference as compared to the control PU. The morphology of both PU was investigated using optical microscope. Contact angle has been measured to determine the hydrophobicity of the PU. The PU- NaHCO3 exhibited an increase in contact angle (93.1°).

  11. Investigation of Soil Liquefaction Potential around Efteni Lake in Duzce Turkey: Using Empirical Relationships between Shear Wave Velocity and SPT Blow Count (N

    Directory of Open Access Journals (Sweden)

    Ali Ateş

    2014-01-01

    Full Text Available Evaluation of the liquefaction potential of a liquefaction-prone area is important for geotechnical earthquake engineering, both for assessment for site selection and for planning and new constructions. The liquefaction potential index for the city of Duzce in northwestern Turkey using the empirical relationships between the Standard Penetration Test (SPT and the Shear Wave Velocity Test (VS was investigated in this study. After, VS values based on SPT blow counts (N were obtained from the alluvial soils in the city of Duzce. The liquefaction potential indexes of the soils were determined using the empirical relationships between the Standard Penetration Test (SPT and the Shear Wave Velocity Test (VS calculating for a probable earthquake of MW=7.2. In the result of the study, the liquefaction potential index (LPI values were interpreted and compared evaluating the SPT N blow count values obtained from the study area. Based on the empirical relationships assumed for the soils, it was observed that there was not a perfect agreement between the results of the two methods. The liquefaction potential index values using the SPT N blow counts were found to be lower than those of the VS method.

  12. Thermal large Eddy simulations and experiments in the framework of non-isothermal blowing; Simulations des grandes echelles thermiques et experiences dans le cadre d'effusion anisotherme

    Energy Technology Data Exchange (ETDEWEB)

    Brillant, G

    2004-06-15

    The aim of this work is to study thermal large-eddy simulations and to determine the nonisothermal blowing impact on a turbulent boundary layer. An experimental study is also carried out in order to complete and validate simulation results. In a first time, we developed a turbulent inlet condition for the velocity and the temperature, which is necessary for the blowing simulations.We studied the asymptotic behavior of the velocity, the temperature and the thermal turbulent fluxes in a large-eddy simulation point of view. We then considered dynamics models for the eddy-diffusivity and we simulated a turbulent channel flow with imposed temperature, imposed flux and adiabatic walls. The numerical and experimental study of blowing permitted to obtain to the modifications of a thermal turbulent boundary layer with the blowing rate. We observed the consequences of the blowing on mean and rms profiles of velocity and temperature but also on velocity-velocity and velocity-temperature correlations. Moreover, we noticed an increase of the turbulent structures in the boundary layer with blowing. (author)

  13. The Application of Bottom Blowing Stirring to Consteel Furnace%底吹搅拌在Consteel电炉中的应用

    Institute of Scientific and Technical Information of China (English)

    董凯; 李金伟; 朱长富

    2011-01-01

    By study of principles of bottom blowing stirring in EAF, the paper analysed the influence from EAF steelmaking bottom blowing stirring process to metallurgical process and formulated the feasible. In the first steel making factory in TONGHUA steel company, EAF bottom blowing stirring system was installed in the 70 tons' s Consteei Furnace. The result showed: EAF blowing stirring technology could effectively strengthen the stirring intensity of molten pool, and then improve the molten pool decarbonization speed, dephosphorizationrates, reduce the content of FeO in end slag, oxygen consumption, shorten the tap to tap time, and provide efficient help for EAF melting.Smelting cost analysis indicated that EAF bottom blowing stirring process could effectively reduce the smelting cost, provide cheap and effective solutions for the EAF high-effectiveness steel making.%通过对电弧炉底吹搅拌工艺技术原理的研究,分析了电弧炉底吹搅拌工艺对炼钢冶金过程的影响,进而制定了合理可行的底吹工艺参数.在通钢第一炼钢厂在70 t Consteel电弧炉上安装了电弧炉底吹搅拌系统,冶炼结果表明:电弧炉底吹工艺能有效加强熔池搅拌强度,从而提高电弧炉熔池脱碳速度、脱磷率,降低终渣FeO含量,降低氧气消耗,缩短熔炼周期,为电弧炉高效冶炼提供帮助;冶炼成本分析表明,电弧炉底吹搅拌能有效降低冶炼成本,为电弧炉高效化炼钢提供了廉价而有效的途径.

  14. Intelligent soot blowing for boilers co-firing waste and biofuel; Behovsstyrd sotblaasning foer bio- och avfallseldade pannor - inventering och teknikval

    Energy Technology Data Exchange (ETDEWEB)

    Kjoerk, Anders [S.E.P. Scandinavian Energy Project AB, Goeteborg (Sweden)

    2003-11-01

    To achieve optimum boiler operation and performance it is necessary to control the cleanliness and limit the fouling of the heat transfer surfaces. Historically, the heating surfaces in boilers firing biomass and waste are cleaned by steamblowing soot blowers on scheduled time-based and/or parameter-based intervals or by mechanical methods. With the advent of fuel switching strategies and use of mixed-in industrial waste, the control of heating surface cleanliness has become even more crucial for these boilers. Scheduled and/or parameter based approaches do not easily address operational changes. As plant operators push to achieve greater efficiency and performance from their boilers, the ability to more effectively optimize cleaning cycles has become increasingly important. If soot blowing is done only when and where it is required rather than at set intervals, unit performance can be maintained with reduced blowing, which saves steam. Two philosophical approaches toward intelligent soot blowing are currently being applied in the industry. One incorporates heat flux monitors to gather real-time heat transfer data to determine which areas of the furnace need cleaning. The other uses indirect temperature and pressure data to infer locations where soot blowing is needed, and is mainly applied for controlling soot blowers in the superheater and economiser area. The heat flux monitors are so fare used for control of the furnace wall blowers. A system using temperature, pressure and flow data does not require much additional instrumentation as compared with what is available on a standard boiler. However the blower control system must be capable of operating blowers on an individual basis. For advanced options it should also be possible to adjust the speed of the soot blower and the steam pressure. The control program could be more or less advanced but the ability to model heating surfaces and determine real-time cleanliness is crucial for an intelligent soot blowing

  15. A global approach to turbomachinery flow control: Loss reduction using endwall suction and midspan vortex generator jet blowing

    Science.gov (United States)

    Bloxham, Matthew Jon

    A flow control scheme using endwall suction and vortex generator jet (VGJ) blowing was employed in an effort to reduce the turbine passage losses associated with the endwall flow field and midspan separation. Unsteady midspan control at low Re had a significant impact on the wake area-average total pressure losses, decreasing the losses by 54%. Initially, the focus of the endwall control was the horseshoe vortex system. The addition of leading edge endwall suction resulted in an area-average total pressure loss reduction of 57%. The minimal additional gains achieved with leading edge endwall suction showed that the horseshoe vortex was a secondary contributor to endwall loss production (primary contributor-passage vortex). A similar flow control strategy was then employed with an emphasis on passage vortex (PV) control. During the design, a theoretical model was used that effectively predicted the trajectory of the passage vortex. The model required inviscid results obtained from two-dimensional CFD. It was used in the design of two flow control approaches, the removal and redirection approaches. The emphasis of the removal approach was the direct application of flow control on the endwall below the passage vortex trajectory. The redirection approach attempted to alter the trajectory of the PV by removing boundary layer fluid through judiciously placed suction holes. Suction hole positions were chosen using a potential flow model that emphasized the alignment of the endwall flow field with inviscid streamlines. Model results were validated using flow visualization and particle image velocimetry (PIV) in a linear turbine cascade comprised of the highly-loaded L1A blade profile. Detailed wake total pressure losses were measured while matching the suction and VGJ massflow rates, for the removal and redirection approaches at ReCx=25000 and blowing ratio, B, of 2. When compared with the no control results, the addition of steady VGJs and endwall suction reduced the wake

  16. Detection of Clostridium tyrobutyricum in milk to prevent late blowing in cheese by automated ribosomal intergenic spacer analysis.

    Science.gov (United States)

    Panelli, Simona; Brambati, Eva; Bonacina, Cesare; Feligini, Maria

    2013-10-01

    Clostridium tyrobutyricum has been identified as the main causal agent of the late blowing defect in cheese, with major effects on quality and commercial value. In this work, for the first time, we applied automated ribosomal intergenic spacer analysis (ARISA) approach to diagnose the presence of C. tyrobutyricum in raw milk before cheesemaking. A species-specific primer set was designed and used for this original application of the ARISA. Sensitivity of detection, reproducibility of the fluorescent PCR assay, and repeatability of the capillary electrophoretic analysis of amplicons were evaluated using DNA extracted from milk added with known amounts of C. tyrobutyricum genome copies, ranging from 3 × 10(6) to 3. Results indicated that the sensitivity of the technique permits to detect the bacterium in all the samples. The reproducibility, evaluated by analyzing 3 sets of serial dilutions, resulted satisfactory, with little deviation within PCR reactions amplifying the same starting amount of template (standard deviations ≤ 0.1, coefficients of variation ≤ 3%). The peaks' fluorescence displayed an evident correspondence with the number of genome copies contained in each dilution. The capillary electrophoretic analysis, tested by running a single PCR product per dilution point in 10 repeats, resulted efficient and highly repeatable, with excellent coefficients of variation ≤ 2% and standard deviations ≤ 0.1 in all the sample sets. This application of ARISA gives good estimates of the total C. tyrobutyricum DNA content allowing a specific, fine-scale resolution of this pollutant species in a complex system as milk. A further advantage linked to the automatization of the process.

  17. AMELIA CESTOL Test: Acoustic Characteristics of Circulation Control Wing with Leading- and Trailing-Edge Slot Blowing

    Science.gov (United States)

    Horne, William C.; Burnside, Nathan J.

    2013-01-01

    The AMELIA Cruise-Efficient Short Take-off and Landing (CESTOL) configuration concept was developed to meet future requirements of reduced field length, noise, and fuel burn by researchers at Cal Poly, San Luis Obispo and Georgia Tech Research Institute under sponsorship by the NASA Fundamental Aeronautics Program (FAP), Subsonic Fixed Wing Project. The novel configuration includes leading- and trailing-edge circulation control wing (CCW), over-wing podded turbine propulsion simulation (TPS). Extensive aerodynamic measurements of forces, surfaces pressures, and wing surface skin friction measurements were recently measured over a wide range of test conditions in the Arnold Engineering Development Center(AEDC) National Full-Scale Aerodynamics Complex (NFAC) 40- by 80-Ft Wind Tunnel. Acoustic measurements of the model were also acquired for each configuration with 7 fixed microphones on a line under the left wing, and with a 48-element, 40-inch diameter phased microphone array under the right wing. This presentation will discuss acoustic characteristics of the CCW system for a variety of tunnel speeds (0 to 120 kts), model configurations (leading edge(LE) and/or trailing-edge(TE) slot blowing, and orientations (incidence and yaw) based on acoustic measurements acquired concurrently with the aerodynamic measurements. The flow coefficient, Cmu= mVSLOT/qSW varied from 0 to 0.88 at 40 kts, and from 0 to 0.15 at 120 kts. Here m is the slot mass flow rate, VSLOT is the slot exit velocity, q is dynamic pressure, and SW is wing surface area. Directivities at selected 1/3 octave bands will be compared with comparable measurements of a 2-D wing at GTRI, as will as microphone array near-field measurements of the right wing at maximum flow rate. The presentation will include discussion of acoustic sensor calibrations as well as characterization of the wind tunnel background noise environment.

  18. Flow Field and Circulation Flow Rate in RH with Side-Bottom Blowing%侧底复吹RH精炼装置内的钢液流场及循环流量

    Institute of Scientific and Technical Information of China (English)

    耿佃桥; 雷洪; 赫冀成

    2011-01-01

    采用数值模拟方法考察了钢包底吹位置对侧底复吹RH装置内流体流动及循环流量的影响.计算结果表明:在钢包底吹条件下,当底吹位置和钢包中心连线与浸渍管中心连线夹角一定时,随着底吹位置至钢包中心距离的增大,循环流量先增大后减小;当底吹位置至钢包中心距离一定时,循环流量随夹角的增大而减小;与现有RH吹氩方式相比,当采用侧底复吹且钢包底吹气量保持在200 L/min时,循环流量可提高25%以上;当关闭上升管侧吹且仅采取钢包底吹时,与现有RH吹氩方式相比,循环流量可提高60%~100%.%The numerical simulation method was employed to investigate the fluid flow and the effect of bottom-blowing location on the circulation flow rate in RH with side-bottom blowing.The numerical results indicated that for RH with bottom blowing,when the included angle is constant between the two lines connecting the bottom-blowing location with ladle center and connecting two snorkels,the circulation flow rate increases firstly and then decreases with the increasing distance between the bottom-blowing location and ladle center.When the distance between the bottom-blowing location and ladle center is constant,the circulation flow rate decreases with the increasing included angle.When the bottom-blowing gas flow rate is equal to 200 L/min,the circulation flow rate in RH with side-bottom blowing is up more than 25 percent.When the side-blowing gas flow rate is equal to zero,the circulation flow rate is 60%~100% greater than that in traditional RH.

  19. Variability of Blowing Dust Weather Frequency over Semi-Arid Areas of China (Baicheng, Jilin Province and Relationships with Climatic Factors During 1951 - 2006

    Directory of Open Access Journals (Sweden)

    Yun-Fei Wu

    2011-01-01

    Full Text Available We analyzed the variability of blowing dust weather frequency (BDWF and patterns in climatic factors over Baicheng for the period 1951 - 2006 in this study. The data showed that blowing dust over Baicheng occurs intensively during the spring and shows significant inter-decadal variability. One of the main findings is that the occurrence of blowing dust has significantly decreased after the mid-1980s. The mean wind speed (WS, diurnal temperature range (DTR, relative humidity (RH and precipitation at Baicheng during the spring show decreasing trends. The decreasing trends of the mean WS and DTR are significant at 99% confidence levels according to the t-test; the dataset also indicated a sharp decrease in WS occurred after the mid-1980s. The mean surface air temperature (SAT escalated in a fluctuating manner during 1951 - 2006. BDWF at Baicheng was significantly related to local WS, SAT and DTR during the spring [correlation coefficients (CCs are 0.41, -0.47 and 0.36, respectively]. The correlation between BDWF at Baicheng and selected climatic factors over the sand-dust source regions and transmission paths were also calculated. We found that BDWF is well correlated to the mean WS and SAT during the spring, with CCs of 0.45 and -0.48, respectively. The most likely causes for the dramatic decrease observed in BDWF after the mid-1980s were related to the adjustment of large-scale circulation patterns in response to a decrease of meridional temperature differences, the weakening of steering westerlies and the strengthening of downward motions that has occurred at the middle latitudes of eastern Eurasia in recent decades.

  20. Deterioration and its improvement of magnetic blow out type surge arresters with series gaps; Jiki fukikeshigata gap tsuki hiraiki no keinen rekka to sono taio

    Energy Technology Data Exchange (ETDEWEB)

    Shirakawa, S.; Ito, M.; Terakado, S.; Iimura, N.; Mizukoshi, A. [Hitachi, Ltd., Tokyo (Japan)

    1995-12-20

    This paper describes deterioration characteristics of 266kV magnetic blow out type surge arrester with series gaps having actual about 30 years operation, and metal oxide surge arrester as its improvement. Main deteriorated components of surge arresters are extinguished chambers closed in series gaps, grading resistors for series gaps and covers for sealing. In case of deterioration of covers, water contents immerse into porcelain containers. Power frequency spark over voltage decreases gradually. Finally, surge arresters are possible to fail down at normal operating voltage. It is important to seal covers with gaskets between porcelain fittings and ceramics porcelains. 14 refs., 16 figs., 3 tabs.

  1. Funny Face y Blow Up: dos paradigmas del diálogo entre fotografía de moda y cine

    OpenAIRE

    2013-01-01

    El mundo de la fotografía de moda ha sido abordado por el cine desde las perspectivas más glamurosas hasta las más sombrías, de lo que dan cuenta producciones como Prêt-a-Porter (Robert Altman, 1994) o Los ojos de Laura (Irvin Kershner, 1978), entre otras. No centraremos aquí en Funny Face (Stanley Donen, 1957) y en Blow-Up (Michelangelo Antonioni, 1966) donde la fotografía se convierte en un elemento clave de la narración. Además, en ambas se establece un diálogo entre estas dos discip...

  2. Meat Feeding Restricts Rapid Cold Hardening Response and Increases Thermal Activity Thresholds of Adult Blow Flies, Calliphora vicina (Diptera: Calliphoridae).

    Science.gov (United States)

    Coleman, Paul C; Bale, Jeffrey S; Hayward, Scott A L

    2015-01-01

    Virtually all temperate insects survive the winter by entering a physiological state of reduced metabolic activity termed diapause. However, there is increasing evidence that climate change is disrupting the diapause response resulting in non-diapause life stages encountering periods of winter cold. This is a significant problem for adult life stages in particular, as they must remain mobile, periodically feed, and potentially initiate reproductive development at a time when resources should be diverted to enhance stress tolerance. Here we present the first evidence of protein/meat feeding restricting rapid cold hardening (RCH) ability and increasing low temperature activity thresholds. No RCH response was noted in adult female blow flies (Calliphora vicina Robineau-Desvoidy) fed a sugar, water and liver (SWL) diet, while a strong RCH response was seen in females fed a diet of sugar and water (SW) only. The RCH response in SW flies was induced at temperatures as high as 10°C, but was strongest following 3h at 0°C. The CTmin (loss of coordinated movement) and chill coma (final appendage twitch) temperature of SWL females (-0.3 ± 0.5°C and -4.9 ± 0.5°C, respectively) was significantly higher than for SW females (-3.2 ± 0.8°C and -8.5 ± 0.6°C). We confirmed this was not directly the result of altered extracellular K+, as activity thresholds of alanine-fed adults were not significantly different from SW flies. Instead we suggest the loss of cold tolerance is more likely the result of diverting resource allocation to egg development. Between 2009 and 2013 winter air temperatures in Birmingham, UK, fell below the CTmin of SW and SWL flies on 63 and 195 days, respectively, suggesting differential exposure to chill injury depending on whether adults had access to meat or not. We conclude that disruption of diapause could significantly impact on winter survival through loss of synchrony in the timing of active feeding and reproductive development with favourable

  3. Meat Feeding Restricts Rapid Cold Hardening Response and Increases Thermal Activity Thresholds of Adult Blow Flies, Calliphora vicina (Diptera: Calliphoridae.

    Directory of Open Access Journals (Sweden)

    Paul C Coleman

    Full Text Available Virtually all temperate insects survive the winter by entering a physiological state of reduced metabolic activity termed diapause. However, there is increasing evidence that climate change is disrupting the diapause response resulting in non-diapause life stages encountering periods of winter cold. This is a significant problem for adult life stages in particular, as they must remain mobile, periodically feed, and potentially initiate reproductive development at a time when resources should be diverted to enhance stress tolerance. Here we present the first evidence of protein/meat feeding restricting rapid cold hardening (RCH ability and increasing low temperature activity thresholds. No RCH response was noted in adult female blow flies (Calliphora vicina Robineau-Desvoidy fed a sugar, water and liver (SWL diet, while a strong RCH response was seen in females fed a diet of sugar and water (SW only. The RCH response in SW flies was induced at temperatures as high as 10°C, but was strongest following 3h at 0°C. The CTmin (loss of coordinated movement and chill coma (final appendage twitch temperature of SWL females (-0.3 ± 0.5°C and -4.9 ± 0.5°C, respectively was significantly higher than for SW females (-3.2 ± 0.8°C and -8.5 ± 0.6°C. We confirmed this was not directly the result of altered extracellular K+, as activity thresholds of alanine-fed adults were not significantly different from SW flies. Instead we suggest the loss of cold tolerance is more likely the result of diverting resource allocation to egg development. Between 2009 and 2013 winter air temperatures in Birmingham, UK, fell below the CTmin of SW and SWL flies on 63 and 195 days, respectively, suggesting differential exposure to chill injury depending on whether adults had access to meat or not. We conclude that disruption of diapause could significantly impact on winter survival through loss of synchrony in the timing of active feeding and reproductive development with

  4. Do climatic and physical factors affect populations of the blow fly Chrysomya megacephala and house fly Musca domestica?

    Science.gov (United States)

    Ngoen-klan, Ratchadawan; Moophayak, Kittikhun; Klong-klaew, Tunwadee; Irvine, Kim N; Sukontason, Kabkaew L; Prangkio, Chira; Somboon, Pradya; Sukontason, Kom

    2011-11-01

    The blow fly, Chrysomya megacephala (Fabricius), and house fly, Musca domestica L., are medically and forensically important flies. The population dynamic of these flies is essential for both control and forensical aspects. The aim of this study was to investigate the climatic and physical factors affecting the population trend of both species in Chiang Mai province, northern Thailand, using the Geographic Information System (GIS). Based on systematic random sampling, 18 study sites were selected in three districts (Mueang Chiang Mai, Mae Rim, and Hang Dong). Six land use types were involved in the study sites, i.e., disturbed mixed deciduous, mixed deciduous forest, mixed orchard, lowland village, city, and paddy field. Adult flies were sampled every 2 weeks using an in-house prototype reconstructable funnel trap. Two types of bait were used--one with fresh beef viscera for luring M. domestica and the other with 1-day tainted beef viscera for luring C. megacephala. Collections were conducted from May 2009 to May 2010, and analysis of climatic factors (temperature, relative humidity, and light intensity) was carried out. Correlation bivariate analysis was performed initially to determine the relationship between climatic factors and the number of flies. Consequently, an ordinary co-kriging approach, in ArcGIS 9.2, was performed to predict the spatial distribution of flies with land use and climatic factors as co-variables. A total of 63,158 flies were captured, with C. megacephala being the most common species collected (68.37%), while only 1.3% were M. domestica, thus proving that C. megacephala was the most abundant species in several land use types. A significantly higher number of females than males was found in both species. Fly populations can be collected throughout most of the year with a peak in late summer, which shows a positive relation to temperature but negative correlation with relative humidity. C. megacephala was predicted to be abundant in every

  5. Blowing Hot and Cold

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The seesawing of economic and political relations between China and Japan seems likely for the long haul International relations experts have made no secret of the fact that frosty political relations between China and Japan have begun to have an effect on their economic ties. Many even declare that economic cooperation has already started to atrophy

  6. CRISIS FOCUS Blowing Bubbles

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The Chinese stock and property markets have been outperforming expectations, fueled by an unprecedented surge in bank lending. Xie Guozhong, an economist and board member of Rosetta Stone Advisors, argues the robust Chinese economic figures are only propped up by bubbles, whose bursting will lead to a hard landing for the economy. Xie published his opinion in a related article in Caijing Magazine. Edited excerpts follow:

  7. Forensically Important Blow Flies Chrysomya pinguis, C. villeneuvi, and Lucilia porphyrina (Diptera: Calliphoridae) in a Case of Human Remains in Thailand.

    Science.gov (United States)

    Monum, Tawatchai; Sukontason, Kabkaew L; Sribanditmongkol, Pongruk; Sukontason, Kom; Samerjai, Chutharat; Limsopatham, Kwankamol; Suwannayod, Suttida; Klong-Klaew, Tunwadee; Wannasan, Anchalee

    2017-02-01

    This is the first study to report Chrysomya pinguis (Walker) and Lucilia porphyrina (Walker) (Diptera: Calliphoridae) as forensically important blow fly species from human cadavers in Thailand, in addition to Chrysomya villeneuvi (Patton) already known in Thailand. In 2016, a fully decomposed body of an unknown adult male was discovered in a high mountainous forest during winter in Chiang Mai province. The remains were infested heavily with thousands of blow fly larvae feeding simultaneously on them. Morphological identification of adults reared from the larvae, and molecular analysis based on sequencing of 1,247 bp partial mitochondrial cytochrome c oxidase subunit 1 gene (CO1) of the larvae and puparia, confirmed the above mentioned 3 species. The approving forensic fly evidence by molecular approach was described for the first time in Thailand. Moreover, neighbor-joining phylogenetic analysis of the CO1 was performed to compare the relatedness of the species, thereby affirming the accuracy of identification. As species of entomofauna varies among cases in different geographic and climatic circumstances, C. pinguis and L. porphyrina were added to the list of Thai forensic entomology caseworks, including colonizers of human remains in open, high mountainous areas during winter. Further research should focus on these 3 species, for which no developmental data are currently available.

  8. Changes in Blow-Off Velocity Observed in Two Explosives at the Threshold for Sustained Ignition Using the Modified Gap Test

    Science.gov (United States)

    Lee, R. J.; Forbes, J. W.; Tasker, D. G.; Orme, R. S.

    2009-12-01

    The Modified Gap Test was used to quantify different levels of partial reaction for various input stresses. This test configuration has been historically useful in highlighting thresholds for first reaction, sustained ignition, and detonation. Two different HMX based compositions were studied; a cast-cured composition with 87% HMX and a pressed composition with 92% HMX. Each explosive was prepared from large industrially produced batches consisting of different unreactive polymeric binder systems. Short samples (50.8 mm in diameter and 12.7 mm thick) were shock loaded using the standard large-scale gap test donor system. Product-cloud blow-off velocities at the opposite end of the sample were measured using a high-speed digital-camera. Velocity versus input pres sure plots provided changes in reactivity that had developed by the 12.7 mm run distance. Results appear consistent for the lower input stresses. In contrast, the results varied widely in a range of input stresses around the transition to detonation in both explosives. These results indicate that both explosives are subject to large variation in blow-off velocity in a range of input stresses near the threshold for prompt detonation. This is explained by localized variations of HMX particle size and density in industrially prepared samples. Approved for public release, Distribution unlimited, IHDIV Log No. 09-108.

  9. In vitro antimicrobial activity of solution blow spun poly(lactic acid)/polyvinylpyrrolidone nanofibers loaded with Copaiba (Copaifera sp.) oil

    Energy Technology Data Exchange (ETDEWEB)

    Bonan, Roberta F. [Departamento de Engenharia de Materiais (DEMAT), Universidade Federal da Paraíba (UFPB), Cidade Universitária, 58.051-900 João Pessoa, PB (Brazil); Centro de Ciências da Saúde (CCS), Universidade Federal da Paraíba (UFPB), Cidade Universitária, 58.051-900 João Pessoa, PB (Brazil); Bonan, Paulo R.F.; Batista, André U.D.; Sampaio, Fábio C.; Albuquerque, Allan J.R. [Centro de Ciências da Saúde (CCS), Universidade Federal da Paraíba (UFPB), Cidade Universitária, 58.051-900 João Pessoa, PB (Brazil); Moraes, Maria C.B. [Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Ecológica, W/5 Norte (Final) Cenargen (Laboratório de Semioquímicos) ASA NORTE, 70770900 Brasília, DF (Brazil); Mattoso, Luiz H.C. [Laboratório Nacional de Nanotecnologia para o Agronegócio (LNNA), Embrapa Instrumentação Agropecuária (CNPDIA), Rua XV de Novembro, 1452, Centro, 13.560, 970 São Carlos, SP (Brazil); Glenn, Gregory M. [United States Department of Agriculture (USDA), Western Regional Research Center (WRRC), Bioproduct Chemistry and Engineering - BCE, Albany, CA 94710 (United States); and others

    2015-03-01

    In this study poly(lactic acid) (PLA) and polyvinylpyrrolidone (PVP) micro- and nanofiber mats loaded with Copaiba (Copaifera sp.) oil were produced by solution blow spinning (SBS). The Copaiba (Copaifera sp.) oil was characterized by gas chromatography (GC). Neat PLA and four PLA/PVP blends containing 20% (wt.%) oil were spun and characterized by scanning electron microscopy (SEM) and by studying the surface contact angle, in vitro release rate, and antimicrobial activity. All compositions evaluated were able to produce continuous and smooth fibers by SBS. The addition of PVP increased fiber diameter, and decreased the surface contact angle. GC analysis demonstrated that the main component of the Copaiba oil was β-caryophyllene, a known antimicrobial agent. In vitro release tests of Copaiba oil volatiles demonstrated a higher release rate in fibers containing PVP. Fiber mats made from blends containing higher amounts of PVP had greater antimicrobial action against Staphylococcus aureus. The results confirm the potential of the fiber mats for use in controlled drug release and could lead to promising applications in the biomedical field. - Highlights: • An efficient method for production of antimicrobial nanofiber mats using solution blow spinning was reported. • Nanofiber mats containing Copaiba oil were efficient against Staphylococcus aureus. • Nanofiber composition changed morphological properties and antimicrobial action.

  10. 洗发水瓶挤出吹塑模具设计*%Design of Extrusion Blow Mould for Shampoo Bottle

    Institute of Scientific and Technical Information of China (English)

    何亮; 曾雪东

    2013-01-01

    对高密度聚乙烯洗发水瓶的结构进行了分析。根据中空挤出吹塑模具结构的设计特点,基于Pro/E进行了洗发水瓶挤出吹塑模具设计。重点对分型面的选择、切坯口与余料槽、排气系统、冷却系统等关键部位进行了讨论。经生产实践验证,该模具结构设计合理、可靠,成型的塑件质量良好,具有良好的经济效益。%The structure of high density polyethylene shampoo bottle was analysed. According to the design characteristics of hollow extrusion blow mould structure,the shampoo bottle extrusion blow mould was designed based on the Pro/E software. The key points including parting surface selection,cutting mouth and remainder slot,exhaust system and cooling system were discussed in design. The production practice prove that the design of the mould structure is reasonable and reliable,plastic parts formed by the mould have good quality,and the mould has good economic benefits.

  11. Forensically Important Blow Flies Chrysomya pinguis, C. villeneuvi, and Lucilia porphyrina (Diptera: Calliphoridae) in a Case of Human Remains in Thailand

    Science.gov (United States)

    Monum, Tawatchai; Sukontason, Kabkaew L.; Sribanditmongkol, Pongruk; Sukontason, Kom; Samerjai, Chutharat; Limsopatham, Kwankamol; Suwannayod, Suttida; Klong-klaew, Tunwadee; Wannasan, Anchalee

    2017-01-01

    This is the first study to report Chrysomya pinguis (Walker) and Lucilia porphyrina (Walker) (Diptera: Calliphoridae) as forensically important blow fly species from human cadavers in Thailand, in addition to Chrysomya villeneuvi (Patton) already known in Thailand. In 2016, a fully decomposed body of an unknown adult male was discovered in a high mountainous forest during winter in Chiang Mai province. The remains were infested heavily with thousands of blow fly larvae feeding simultaneously on them. Morphological identification of adults reared from the larvae, and molecular analysis based on sequencing of 1,247 bp partial mitochondrial cytochrome c oxidase subunit 1 gene (CO1) of the larvae and puparia, confirmed the above mentioned 3 species. The approving forensic fly evidence by molecular approach was described for the first time in Thailand. Moreover, neighbor-joining phylogenetic analysis of the CO1 was performed to compare the relatedness of the species, thereby affirming the accuracy of identification. As species of entomofauna varies among cases in different geographic and climatic circumstances, C. pinguis and L. porphyrina were added to the list of Thai forensic entomology caseworks, including colonizers of human remains in open, high mountainous areas during winter. Further research should focus on these 3 species, for which no developmental data are currently available. PMID:28285509

  12. 板坯结晶器内吹氩工艺研究%Study on the Water Simulation of Blowing Argon in Slab Mould

    Institute of Scientific and Technical Information of China (English)

    侯泽旺; 王永胜; 王新华

    2011-01-01

    The method of water simulation of blowing argon in slab mould was set forth in the paper, and then the influence of blowing argon in slab mould on the flow field of steel/slag interface of the mould was mainly studied, and the effects of process parameters on the distribution of argon bubble were studied too, such as the mould width, casting speed, submergence depth of SEN, etc, which are all carried out with a full-size water model and the concave shape SEN with the angle of 15°.%阐述了使用水模研究结晶器吹氩的方法,并在全比例水模型上采用15°凹底水口进行模拟,着重研究结晶器吹氩对板坯结晶器内钢/渣界面流态的影响,以及结晶器宽度、拉坯速度、水口浸入深度等工艺参数对结晶器内气泡分布的影响.

  13. 可压缩反应气体模型的一致爆破率%Uniform Blow-Up Rate for a Compressible Reactive Gas Model

    Institute of Scientific and Technical Information of China (English)

    徐润章; 姜晓丽; 刘杰

    2012-01-01

    研究一类带有非线性非局部源项的可压缩反应气体模型方程的Dirichlet初始边界值问题.在一些假设条件下,证明了爆破率在有界域的所有紧子集中是一致的,并且证明了爆破率只与非线性非局部源的指数有关,而与扩散项的指数无关.%The Dirichlet initial-boundary value problem of a compressible reactive gas model equation with nonlocal nonlinear source term was studied. For certain conditions, it is proved that the blow-up rate is uniform in all compact subsets of the domain and the blow-up rate is irrelative to the exponent of the diffusion term, but relative to the exponent of the nonlocal nonlinear source.

  14. Potential flow evaluation of the interference effect of strut-through-appendage-tip model mounting technique and reduction of the effect using blowing and suction

    Science.gov (United States)

    Mellish, Robert W.; Coder, David W.

    1988-11-01

    A parametric study based on incompressible, irrotational flow theory was conducted to evaluate the effect of strut support interference on the flow field about a model. The use of suction and blowing to correct the support interference is also investigated. Two struts were considered for numerical analysis, a small chord strut of constant cross section and a large chord strut of varying cross section, both attached to the tip of a model submarine sail. For the present study the SS N21 class and SSN 688 class sail geometries are utilized. To assess the level of strut interference, the presence fields on the surface of the sail and a flat representation of the hull were evaluated as follows. The flow field was computed for the model geometry without a strut attached (baseline configuration) and the results are compared with identical calculations for the model-strut combination. The calculated results are presented graphically as contour plots of the pressure coefficient (Cp). Contour plots of delta p (the difference between baseline ad sail-strut results) are utilized to identify regions of principal strut interference. Finally, suction and blowing was applied to minimize strut interference in areas considered important to hull boundary layer and sail flow that would affect wake measurements.

  15. Continuous bromine extraction with membrane air-blowing/absorption%膜鼓气/吸收法连续脱溴过程

    Institute of Scientific and Technical Information of China (English)

    高启君; 吴丹; 武春瑞; 陈华艳; 贾悦; 王暄; 吕晓龙

    2011-01-01

    For developing a new energy-efficient technology for bromine extraction, a continuous bromine extraction with membrane air-blowing/absorption (MA-B/A) was designed, in which hydrophobic polyvinylidene fluoride (PVDF) hollow fiber membranes were used as aeration configurations. The compressed air was blown out of the aeration configurations (U-type PVDF membrane modules) in the form of small air bubbles, and entered the membrane modules connected in series separately. Convective mass transfer occurred between small air bubbles and the liquid (simulated sea water), and continuous bromine extraction for the liquid was carried out. The effects of operation conditions, such as the stage number, packing density, flow rate of liquid, air-blowing intensity and the length of air-blowing membrane module, on bromine removal rate were investigated. The optimal parameters of continuous bromine extraction with MA-B/A for 3-stage air-blowing membrane modules were obtained. The experimental results show that the bromine removal rate reaches 82% when the packing density is 13. 4%, the length is 1 m, the flow rate of feed is 0. 5 L ? H-1, and the air-blowing intensity is 7200 mol ? M-2 ? H-1. Scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) analysis show that strong oxidizing bromine has little effect on the performance of PVDF hydrophobic hollow fiber membranes.%以开发节能高效的新型提溴工艺为目的,设计了以中空纤维疏水膜作为布气装置的膜鼓气/吸收( MA-B/A)法连续脱溴过程.压缩空气经过布气装置(U型PVDF中空纤维疏水膜组件)以微小气泡的形式分别进入串联的各级鼓气膜组件,与料液(模拟海水)形成对流传质,实现溴素的连续脱除.考察了鼓气膜组件级数、组件装填密度、料液流量、鼓气强度、组件长度等参数对溴脱除率的影响.实验得到了MA-B/A法3级连续脱溴过程的最佳参数条件.在装填密度为13.4%,料液流量为0.5L

  16. 美国威勒公司吹-灌-封设备的最新动态观察与探讨%Observation and Discussion of the Latest Blow/Fill/Seal Machines of Weiler Engineering

    Institute of Scientific and Technical Information of China (English)

    郦旻; 梁毅

    2012-01-01

    Take ASEP-TECH Blow/Fill/Seal machines of Weiler Engineering,Inc.as an example to introduce the concept and technology of Blow/Fill/Seal machines,for domestic related production companies for reference.%以美国威勒公司的ASEP—TECH吹灌封设备为例,介绍国外吹灌封设备的理念和技术,以备国内相关生产单位借鉴。

  17. 从醋酸厂富碘废水中吹出萃取分离碘%Blowing and Extracting Iodine from Acetic Acid Waste Water

    Institute of Scientific and Technical Information of China (English)

    先桁; 冯鹤; 孙克萍; 陈肖虎

    2012-01-01

    Iodine was recycled from acetic acid wastewater. During extracting process, effecting factors on the result of iodine blowing were discussed based on determinate amount of oxidant. The optimum parameters were obtained, the effects of process parameter on iodine extraction were discussed theoretically.%从醋酸废液中回收碘,在确定氧化剂用量的基础上对碘萃取过程中影响吹出效果的各因素进行试验,获得各项指标的最佳值,并从理论上分析了各因素对萃取碘的影响.为下步碘的还原吸收过程及获取碘产品奠定基础.

  18. Effect of mass and density of ambient gas on the interaction of laser-blow-off plasma plumes propagating in close proximity

    Science.gov (United States)

    Kumar, Bhupesh; Singh, R. K.; Kumar, Ajai

    2016-04-01

    The effects of mass and pressure of ambient gas on the propagation dynamics of two laser-blow-off plasma plumes created in close proximity are investigated. A time gated fast imaging technique is used for recording the images of the laterally colliding plumes under different experimental conditions. Pressure is varied from 0.1 to 3 mbar in three ambient, i.e., helium, neon, and argon. Emphasis is given on the nature of shock-shock interaction under different ambient conditions. It has been observed that the shock-velocity, shape, strength, and their interactions are strongly dependent on the mass and density of the ambient gases. The role of the interacting shocks and their subsequent reflections on the formation and geometrical shape of the interaction region in different ambient conditions is briefly described.

  19. 混合澄清槽吹气测量方法研究%Study on blowing air measurement method of the Mixer-Settler

    Institute of Scientific and Technical Information of China (English)

    董春华

    2013-01-01

    This article presents the Mixer-Settler and measuring method briefly, mainly introduces the solutions of key problems in the period of research on the Mixer-Settler, the solutions of these problems are proved feasible and accurate. So it is showed that using blowing air measures paraments of the Mixer-Settler is achieved.%  本文简要介绍了混合澄清槽及其测量方法,主要介绍了混合澄清槽测量研究过程中一些关键问题的解决,这些问题的解决,经验证是可行的、准确的,表明采用吹气测量混合澄清槽参数是可实现的。

  20. Manufacturing a Porous Structure According to the Process Parameters of Functional 3D Porous Polymer Printing Technology Based on a Chemical Blowing Agent

    Science.gov (United States)

    Yoo, C. J.; Shin, B. S.; Kang, B. S.; Yun, D. H.; You, D. B.; Hong, S. M.

    2017-09-01

    In this paper, we propose a new porous polymer printing technology based on CBA(chemical blowing agent), and describe the optimization process according to the process parameters. By mixing polypropylene (PP) and CBA, a hybrid CBA filament was manufactured; the diameter of the filament ranged between 1.60 mm and 1.75 mm. A porous polymer structure was manufactured based on the traditional fused deposition modelling (FDM) method. The process parameters of the three-dimensional (3D) porous polymer printing (PPP) process included nozzle temperature, printing speed, and CBA density. Porosity increase with an increase in nozzle temperature and CBA density. On the contrary, porosity increase with a decrease in the printing speed. For porous structures, it has excellent mechanical properties. We manufactured a simple shape in 3D using 3D PPP technology. In the future, we will study the excellent mechanical properties of 3D PPP technology and apply them to various safety fields.

  1. CONTRIBUTION A L’AMELIORATION DU SYSTEME DE CLIMATISATION DES VOITURES DE VOYAGEURS DE LA SNTF

    OpenAIRE

    YOUCEF, Ahmed

    2011-01-01

    L’accroissement de l’effet de serre et la diminution de la couche d’ozone ont marqué ces dix dernières années, les gaz frigorigènes classiques tels que les CFC (chlorofluorocarbones),HCFC (hydrochlorofluorocarbones) participent respectivement à la destruction de la couche d’ozone et à l’effet de serre. Les secteurs du froid et de la climatisation sont des domaines en pleine expansion non seulement dans les pays industrialisés mais aussi dans les pays en voie de développement. La communa...

  2. Air; Air

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2000-09-01

    The regulation (CE/2037/2000) of the Parliament and Council of Europe of the 29. of June 2000 amends and replaces the regulation (CE/3093/94) relative to substances impoverishing the ozone layer. It applies to the production, the import, the export, the marketing, the use, the recovery, the recycling, the regeneration and the destruction of chlorofluorocarbons (CFC), other CFC (entirely halogenated), halons, carbon tetrachloride, 1,1,1-tri-chloro-ethane, methyl bromide, hydro-bromo-fluorocarbons and hydro-chlorofluorocarbons (HCFC) and of all products which contain these substances. It applies too to data to be reported on these substances. (O.M.)

  3. Failure of Sterne- and Pasteur-like strains of Bacillus anthracis to replicate and survive in the urban bluebottle blow fly Calliphora vicina under laboratory conditions.

    Directory of Open Access Journals (Sweden)

    Britta von Terzi

    Full Text Available This study aimed to elucidate the bacteriological events occurring within the gut of Calliphora vicina, selected as the European representative of blow flies held responsible for the spread of anthrax during epidemics in certain parts of the world. Green-fluorescent-protein-carrying derivatives of Bacillus anthracis were used. These lacked either one of the virulence plasmids pXO1 and pXO2 and were infected, or not infected, with a worm intestine phage (Wip4 known to influence the phenotype and survival of the pathogen. Blood meals were prepared for the flies by inoculation of sheep blood with germinated and, in case of pXO2+ strains, encapsulated cells of the four B. anthracis strains. After being fed for 4 h an initial 10 flies were externally disinfected with peracetic acid to ensure subsequent quantitation representing ingested B. anthracis only. Following neutralization, they were crushed in sterile saline. Over each of the ensuing 7 to 10 days, 10 flies were removed and processed the same way. In the absence of Wip4, strains showed steady declines to undetectable in the total B. anthracis counts, within 7-9 days. With the phage infected strains, the falls in viable counts were significantly more rapid than in their uninfected counterparts. Spores were detectable in flies for longer periods than vegetative bacteria. In line with the findings in both biting and non-biting flies of early workers our results indicate that B. anthracis does not multiply in the guts of blow flies and survival is limited to a matter of days.

  4. Improved soot blowing, based on needs, through measurement of the natural frequency of the heat transferring tubes; Foerbaettrad behovsstyrd sotning genom maetning av oeverfoerande tubernas egenfrekvens

    Energy Technology Data Exchange (ETDEWEB)

    Blom, Elisabet; Ivarsson, Christofer

    2007-11-15

    The aim of the project is to develop a method for detecting soot on the transferring tubes by measuring the Eigen frequency of the tubes as a function of the soot deposit growth. The project is a pilot study independent of boiler type and it is applicable to all boilers where soot deposit on transferring tubes is a repeating issue. The report is supposed to answer two major questions. Is it possible to make use of Eigen frequencies in order to trace soot deposit on transferring tubes? What governing parameters are related to the Eigen frequency of transferring tubes? By today, soot blowing is executed after recommendations from the manufacturer in terms of number of soot blowing per time unit. The fuel type as well as boiler type has great influence on the soot deposit growth. The objective of the project is to investigate whether the mechanical properties of the transferring tube can be used to detect soot deposit. The project is divided into a theoretical and a practical part. The theoretical part covers the design of the probe and the change of its mechanical properties when soot deposit is present. Practical experiments were then carried out in a laboratory were the probes mechanical properties with and without soot deposit were investigated. It was shown that the Eigen frequency of the probe decreased with an increased mass due to soot deposit. A test was also made in a boiler at SAKAB but difficulties in attaching the probe to the inspection hatch. The results varied and the interpretation of the results become difficult. However, it was obvious that the mechanical properties of the probe changed with the amount of soot deposit. It was concluded that detection of soot deposit by studying the mechanical properties of the transferring tubes is possible. Yet, using a probe is no optimal solution, instead measurements should be done directly on the heat transferring tubes. In addition, a strategy for controlling the soot deposit has to be developed

  5. Evaluation of the Biodegradable Plates (PG910/PDO) for Reconstruction of Various Sizes of Orbital Floor Defects in the Blow-Out Fractures.

    Science.gov (United States)

    Tabrizi, Reza; Langner, Nicole J; Pouzesh, Ayatollah; Arabion, Hamidreza

    2013-09-01

    The aim of our study was to evaluate the biodegradable plates (PG910/PDO) for reconstruction of various sizes of the orbital floor defects in the blow-out fractures. We included patients who had an impure blow-out fracture. All patients had a recent trauma and also the surgical intervention was done between 1 and 10 days after trauma. The amount of the orbital floor defect was measured in each case through computed tomography scan. In the surgical intervention, a biodegradable plate was used for the reconstruction of the orbital floor defect along with titanium miniplates used for bone fixation in orbital rim. Due to aesthetic reasons, all patients underwent secondary surgery including removal of titanium miniplates after 18 months. The orbital floor was reevaluated during the removal of the miniplates. The clinical evaluation of remnant defects and biodegradable plates (presence of complete or partial resorption) were documented for each patient. In our study a total of 15 patients (10 males and 5 females) underwent the orbital floor reconstruction using biodegradable miniplates. The size of the orbital floor defects was meanly 3.51 ± 1.29 cm(2). Results demonstrated that 4 out of 15 patients had a remnant defect after resorption of the biodegradable plate. In 10 out of 15 patients, the biodegradable plates completely replaced with fibrous tissues after 18 months. Remaining five patients had partial resorption of plates. There was not any relationship between the defect size and the remnant defects (p > 0.05). A significant relationship was seen between the defect size and the plates' resorption rate (p biodegradable plates is an appropriate option for reconstruction of the orbital floor defects. The defect size does not have any effect on the stability of the plate. However, incomplete plate resorption increases the risk of remnant defects in the orbital floor. The larger defects lead to slow degradation of biodegradable plates.

  6. Scanning electron microscopic studies on antenna of Hemipyrellia ligurriens (Wiedemann, 1830) (Diptera: Calliphoridae)-A blow fly species of forensic importance.

    Science.gov (United States)

    Hore, Garima; Maity, Aniruddha; Naskar, Atanu; Ansar, Waliza; Ghosh, Shyamasree; Saha, Goutam Kumar; Banerjee, Dhriti

    2017-08-01

    Blow flies (Diptera: Calliphoridae) are one of the foremost organisms amongst forensic insects to colonize corpses shortly after death, thus are of immense importance in the domain of forensic entomology. The blow fly Hemipyrellia ligurriens (Wiedemann, 1830) (Diptera: Calliphoridae) is considered as a forensically important fly species globally and is also known for its medical and veterinary importance. In the present study, we report for the first time scanning electron microscopic studies on the morphology of sensilla of antenna of adult male and female of H. ligurriens is with profound importance in better understanding of the insect morphology from forensic entomological perspective, and also could aid in proper identification of the species from other calliphorid flies. The structural peculiarities observed in the (i) antenna of H. ligurriens with three segments- scape, pedicel and flagellum with dorso-laterally placed arista (ii) densely covered microtrichia and most abundant trichoid sensilla identified on the antenna (iii) observation of only one type of sensilla, chaetic sensilla (ChI) on the scape (iv) two types of chaetic sensilla (ChI and ChII) and styloconic sensilla on the pedicel (v) the flagellum with three types of sensilla- trichoid, basiconic and coeloconic sensilla (vi) Basiconic sensilla with multiporous surfaces with characteristic olfactory function. Moderate sexual dimorphism in the width of the flagellum, the females with wider flagella than the males, bear significance to the fact that they bear more multi-porous sensilla than the males, thus suffice their need to detect oviposition sites. Significant difference was observed in the length and width of coeloconic sensilla between the two sexes, the females showed bigger coeloconic sensilla, suggesting their function in oviposition site detection and successful colonization in corpses. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. 基于CFD的潜艇高压气吹除主压载水舱系统模拟%The simulation research of high Pressure air blowing the main ballast tank based on CFD

    Institute of Scientific and Technical Information of China (English)

    李其修; 刘辉; 吴向君

    2012-01-01

    高压气吹除主压载水舱是潜艇舱室进水情况下最有效的应急挽回手段之一.由于高压气吹除时压载水舱中剧烈的气液混合流动,导致建立的理论模型有一定局限性.本文通过CFD中两相流VOF模型对高压气吹除压载水舱的动态过程进行仿真,分析吹除过程中压载水舱中气-液混合现象、压力变化情况及压载水舱排水速率等特点,以验证高压气吹除压载水舱的理论模型.%The high pressure air blowing ballast tanks are the most effective means of emergency to restore under flooded submarine. As the process of blowing, there will bring the flow of exquisite gas-liquid mixture in the ballast compartment. This led to the theoretical models that have certain limitations. The paper simulates the dynamic process of high-pressure air blowing ballast tanks by VOF two-phase flow model to analyze gas-liquid mixture phenomena, pressure changes, the ballast tank drainage rate during the process of blowing ballast tank, which provides the basis to theoretical models for the establishment of the high pressure air blowing ballast tanks.

  8. Influence of discharge parameters on blow-by in a coaxial plasma gun%放电参数对同轴枪中等离子体团的分离的影响

    Institute of Scientific and Technical Information of China (English)

    张俊龙; 杨亮; 闫慧杰; 滑跃; 任春生

    2015-01-01

    同轴枪中的等离子体团的分离现象主要是由同轴枪内磁场的梯度造成的电流层倾斜而引起的一个增强反馈过程导致的,这种分离现象越来越成为限制同轴枪有效使用的一个不利因素。在实验上研究放电参数对等离子体团的分离的影响,对理论研究和实际应用都具有重要意义。在实验中发现,利用光电倍增管可以直接观察到等离子体团的分离程度,由此可以研究放电参数对等离子体团的分离的影响。本实验主要研究电容充电电压、电容、放电气压这三个参数对分离现象的影响。实验发现,分离程度随着电容以及其充电电压的增大而增强,随着气压的增大而减弱。实验结果基于雪犁模型进行分析,电容以及电容充电电压的增大使放电电流增强使磁场梯度增大而导致电流层的倾斜程度增加,而使等离子体团的分离程度变严重,相反,气压的增加使需要加速更多粒子而导致电流层的倾斜程度减弱,而使等离子体团分离程度减弱。分析认为,通过控制在加速过程中影响电流层倾斜程度的因素可控制共轴枪中等离子体团的分离程度。%The blow-by which occurs in a coaxial plasma gun is the result of reinforcing feedback caused by the gradient of magnetic field and the component of axial current due to the canting of current sheath. The blow-by has become a serious negative effect which limits the effective use of the coaxial plasma gun, so it is necessary to study by experiment the parameters that influence the degree of blow-by. This will not only contribute to the study of the theory and mode about blow-by but also give advices to the weakening or eliminating blow-by by choosing suitable parameters in engineering field. The degree of blow-by can be observed directly by photomultiplier, and the influence of voltage of capacitance, capacitance, and the pressure of gas on blow-by have

  9. Numerical study on b oundary-layer receptivity with lo calized wall blowing/suction%壁面局部吹吸边界层感受性的数值研究∗

    Institute of Scientific and Technical Information of China (English)

    陆昌根; 沈露予

    2015-01-01

    Most of previous studies focused on the boundary-layer receptivity to the convected disturbances in the free stream interacting with localized wall roughness. Whereas the research on the boundary-layer receptivity induced by localized blowing or localized suction is relatively few. In this paper, we investigate two-dimensional boundary-layer receptivity induced by localized blowing/suction within free-stream turbulence through using direct numerical simulation and fast Fourier transformation. High-order compact finite difference schemes in the y-direction, fast Fourier transformation in the x-direction, and a Runge-Kutta scheme in time domain are used to solve the Navier-Stokes equations. The numerical results show that Tollmien-Schlichting (T-S) wave packets are excited by the free-stream turbulence interacting with localized blowing in the two-dimensional boundary layer, which are superposed by a group of stable, neutral and unstable T-S waves. The dispersion relations, growth rates, amplitude distributions and phase distributions of the excited waves accord well with theoretical solutions of the linear stability theory, thus confirming the existence of the boundary-layer receptivity. And the frequencies of the instability waves are between the upper and lower branches of the neutral stability curves. According to the evolutions of the wave packets, the positions of peaks and valleys are tracked over time to calculate the propagation speed by taking the average. The propagation speeds of the wave packets are approximately one-third of the free-stream velocity, which are in accordance with Dietz’s measurements. The propagation speeds of wave packets are also close to the phase speeds of the most unstable waves for the numerical results. The relations of the receptivity response to the forcing amplitude, the blowing intensity, and the blowing width are found to be linear, when the forcing amplitude and the blowing intensity are less than 1% free-steam velocity

  10. A novel route to large-scale and robust free-standing TiO{sub 2} nanotube membranes based on N{sub 2} gas blowing combined with methanol wetting

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Ghafar; Yoo, Seung Hwa; Kum, Jong Min; Kim, Yong Nam; Cho, Sung Oh [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology (KAIST), 373-1 Guseong, Yuseong, Daejeon 305-701 (Korea, Republic of)

    2011-06-17

    We present a novel and straightforward approach to fabricate large-scale and robust free-standing TiO{sub 2} nanotube (TNT) membranes. Simply by blowing N{sub 2} gas onto as-anodized TNTs that are wetted with methanol, free-standing TNT membranes are produced. The approach also provides homogeneous and honeycomb-like Ti substrates after the detachment of TNT membranes. Through the second anodization of the honeycomb-like Ti substrates following the N{sub 2} blowing, TNT membranes comprising hexagonally close-packed and regularly ordered TNTs with clear open ends can be achieved. Characterization of the free-standing TNT membranes using Raman spectroscopy and a high-resolution transmission electron microscope reveals that anatase TiO{sub 2} and crystalline graphitic carbon are embedded in the bottom surface of the free-standing TNT membranes.

  11. Analysis of Green Technology for Automatic PET Bottle Stretch Blow Molding Equipment%全自动PET瓶拉吹成型设备绿色化技术浅析

    Institute of Scientific and Technical Information of China (English)

    陈思红; 张友根

    2012-01-01

    The green technology of automatic PET bottle stretch blow molding equipment mainly reflects in improving energy efficiency, reducing molding processing costs, reducing environmental pollution, improving the cleanliness, and multi-functional, specialization and intelligent control et al. The high-speed is a sign of green technical level of automatic PET bottle stretch blow molding equipment.%全自动PET瓶拉吹成型设备绿色化技术主要体现在提高能源利用效率、降低成型加工成本、减少对环境的污染、提高清洁度、多功能化、专用化、控制智能 化等方面.高速化是全自动PET瓶拉吹成型设备绿色化技术水平的标志.

  12. An analytical inversion method for determining regional and global emissions of greenhouse gases: Sensitivity studies and application to halocarbons

    Directory of Open Access Journals (Sweden)

    A. Stohl

    2009-03-01

    Full Text Available A new analytical inversion method has been developed to determine the regional and global emissions of long-lived atmospheric trace gases. It exploits in situ measurement data from three global networks and builds on backward simulations with a Lagrangian particle dispersion model. The emission information is extracted from the observed concentration increases over a baseline that is itself objectively determined by the inversion algorithm. The method was applied to two hydrofluorocarbons (HFC-134a, HFC-152a and a hydrochlorofluorocarbon (HCFC-22 for the period January 2005 until March 2007. Detailed sensitivity studies with synthetic as well as with real measurement data were done to quantify the influence on the results of the a priori emissions and their uncertainties as well as of the observation and model errors. It was found that the global a posteriori emissions of HFC-134a, HFC-152a and HCFC-22 all increased from 2005 to 2006. Large increases (21%, 16%, 18%, respectively from 2005 to 2006 were found for China, whereas the emission changes in North America (−9%, 23%, 17%, respectively and Europe (11%, 11%, −4%, respectively were mostly smaller and less systematic. For Europe, the a posteriori emissions of HFC-134a and HFC-152a were slightly higher than the a priori emissions reported to the United Nations Framework Convention on Climate Change (UNFCCC. For HCFC-22, the a posteriori emissions for Europe were substantially (by almost a factor 2 higher than the a priori emissions used, which were based on HCFC consumption data reported to the United Nations Environment Programme (UNEP. Combined with the reported strongly decreasing HCFC consumption in Europe, this suggests a substantial time lag between the reported time of the HCFC-22 consumption and the actual time of the HCFC-22 emission. Conversely, in China where HCFC consumption is increasing rapidly according to the UNEP data, the a posteriori emissions are only about 40% of the a

  13. Successful rescue from cardiac arrest in a patient with postinfarction left ventricular blow-out rupture: "extra-pericardial aortic cannulation" for establishment total cardiopulmonary bypass.

    Science.gov (United States)

    Ohira, Suguru; Yaku, Hitoshi; Nakajima, Shunsuke; Takahashi, Akihiko

    2014-08-01

    We report a quick and simple technique to establish cardiopulmonary bypass (CPB) in a left ventricular (LV) blow-out rupture. A 74-year-old woman with a diagnosis of acute myocardial infarction suddenly collapsed and lost consciousness. A venous-arterial extracorporeal membrane oxygenation (ECMO) device was inserted by femoral cannulation. Emergent median sternotomy was performed. The pericardium was not opened first, and the thymus was divided to expose the ascending aorta just above the pericardial reflection. After placing two purse-string sutures on the distal ascending aorta, a 7-mm aortic cannula (Terumo, Tokyo, Japan) was inserted. The pericardium was then incised. A large volume of blood was expelled from the pericardial space, and CPB was initiated with suction drainage. A two-stage venous drainage cannula was then inserted from the right atrial appendage without hemodynamic collapse. After cardiac arrest, closure of ruptured LV wall and concomitant coronary artery bypass grafting were performed. The patient was weaned from CPB with an intra-aortic balloon pump (IABP) and the previously inserted venous-arterial ECMO. Extra-pericardial aortic cannulation is an effective and reproducible method to prepare for CPB in emergent cases of LV rupture.

  14. Enfisema orbitário compressivo após asseio nasal: relato de caso Sight-threatening orbital emphysema after nose blowing: case report

    Directory of Open Access Journals (Sweden)

    Bruno de Albuquerque Furlani

    2009-04-01

    Full Text Available O enfisema orbitário é caracterizado pela presença anormal de ar na órbita. Sua ocorrência espontânea não é frequente e a maioria dos casos está associada à fratura de órbita. Relatamos o caso de uma paciente do sexo feminino de 40 anos com quadro de enfisema orbitário unilateral, secundário a asseio vigoroso do nariz. A paciente evoluiu com redução aguda da acuidade visual em decorrência de elevação da pressão intraocular, sendo indicado tratamento de urgência. Foi realizada punção orbitária com agulha 24-gauge próximo à região da incisura supraorbital, com melhora imediata do quadro clínico e recuperação da acuidade visual.Orbital emphysema is the abnormal presence of air in the orbit. Occurrence in the absence of orbital fracture is rare. We report a case of a 40-year-old female presenting unilateral orbital emphysema after vigorous nose blowing. She developed sudden visual loss as a result of elevated intraocular pressure and urgent treatment was required. She underwent an orbital decompression, performed using a 24-gauge needle puncture adjacent to the supraorbital notch. After treatment, she reported considerable decrease of symptoms.

  15. Release of the Diclofenac Sodium by Nanofibers of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate Obtained from Electrospinning and Solution Blow Spinning

    Directory of Open Access Journals (Sweden)

    Michelle Andrade Souza

    2014-01-01

    Full Text Available Electrospun fibers are explored as a new system for controlled drug delivery. Novel techniques capable of obtaining polymer nanofibers have been reported in the literature. They include solution blow spinning (SBS, which is a technique to produce polymer nanofibers in the same range as electrospinning, using pressurized gas instead of high voltage. The present study investigates release characteristics of diclofenac sodium encapsulated at three concentrations (5, 10, and 20% w/v in poly(3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV nanofibers made by electrospinning and SBS and determines the drug’s effect on fiber morphology and structural properties. PHBV nanofibers were characterized using scanning electronic microscopy, differential scanning calorimetry, and X-ray diffraction, and the release profile was examined via UV-Vis spectrophotometry. Both electrospinning and SBS encapsulated diclofenac sodium in PHBV membranes efficiently and effectively. The profile of the in vitro release of diclofenac sodium was dependent on drug concentration and temperature. The drug reduced crystallinity and increased flexibility.

  16. Decision-making Task Hierarchical Decomposition of Blowing Time Sensitive Target%打击时敏目标的决策任务层次分解磁

    Institute of Scientific and Technical Information of China (English)

    黄培荣; 宋剑; 李楠

    2014-01-01

    针对打击时敏目标的决策任务层次分解,以任务求解为驱动,综合考虑任务的结构特征,提出决策任务层次分解的基本思想,进而重点研究了基于人件服务的复杂决策任务层次分解算法,为打击时敏目标决策任务流程规划与设计提供理论支撑。%Aiming at hierarchical decomposition for decision-making tasks of combat time sensitive target ,the goal is to solve the task .Considering the structural characteristics of the task ,the basic idea of decision-making tasks hierarchical de-composition is proposed .And then the hierarchical decomposition algorithm of the complex decision-making task based on personnel services is focused on to provide theoretical support for the process planning and design of decision-making tasks of blowing time sensitive target .

  17. Euthanasia, assisted suicide, and cessation of life support: Japan's policy, law, and an analysis of whistle blowing in two recent mercy killing cases.

    Science.gov (United States)

    Akabayashi, Akira

    2002-08-01

    Issues pertaining to euthanasia, assisted suicide, and cessation of life support continue to be a subject of worldwide interest. Euthanasia- particularly "active" euthanasia- is not considered legally or socially acceptable in most countries. In Japan, the first judgment of a case involving euthanasia took place in 1949. Since then there have been another five cases that reached the point of sentencing in 1990. All six cases were examples of so called "active euthanasia", in which the termination of life was performed by family members. However, the focus of discussion has been changed dramatically in recent years, owing to two prominent cases of mercy killing in 1995 (Yokohama) and 1996 (Kyoto), respectively. Medical doctors were involved in both of these cases, and euthanasia moved from being a theoretical problem to a practical dilemma. These cases also drew attention to the fact that assisted suicide could be distinguished from euthanasia. The first part of this paper will summarize the current status of euthanasia and the cessation of life support in Japan, focusing on its historical background and policy. The second part will briefly sketch the characteristics of Japanese law and then will examine the two recent cases of mercy killing mentioned above to try and determine the roles of whistle blowing in the medical practice arena, with particular reference to Japanese culture. This analysis is a challenge to elucidate how ethics and the law interact, and influence medical practice in a specific cultural context.

  18. FMRFamide-like immunoreactivity in the central nervous system and alimentary tract of the non-hematophagous blow fly, Phormia regina, and the hematophagous horse fly, Tabanus nigrovittatus.

    Science.gov (United States)

    Haselton, Aaron T; Yin, Chih-Ming; Stoffolano, John G

    2008-01-01

    FMRFamide-related peptides (FaRPs) are a diverse and physiologically important class of neuropepeptides in the metazoa. In insects, FaRPs function as brain-gut neuropeptides and have been immunolocalized throughout the nervous system and alimentary tract where they have been shown to affect feeding behavior. The occurrence of FMRFamide-like immunoreactivity (FLI) was examined in the central nervous system and alimentary tract of non-hematophagous blow fly, Phormia regina Meigen (Diptera: Calliphoridae), and the hematophagous horse fly, Tabanus nigrovittatus Macquart (Diptera:Tabanidae). Although the central nervous system and alimentary anatomy differ between these two dipteran species, many aspects of FLI remain similar. FLI was observed throughout the central and stomatogastric nervous systems, foregut, and midgut in both flies. In the central nervous system, cells and processes with FLI occurred in the brain, subesophageal ganglion, and ventral nerve cord. FLI was associated with neurohemal areas of the brain and ventral nerve cord. A neurohemal plexus of fibers with FLI was present on the dorsal region of the thoracic central nervous system in both species. In the gut, processes with FLI innervated the crop duct, crop and anterior midgut. Endocrine cells with FLI were present in the posterior midgut. The distribution of FLI in these two flies, in spite of their different feeding habits, further supports the role of FaRPs as important components of the braingut neurochemical axis in these insects and implicates FaRPs as regulators of insect feeding physiology among divergent insect taxa.

  19. Comparative Studies of Electrospinning and Solution Blow Spinning Processes for the Production of Nanofibrous Poly(L-Lactic Acid Materials for Biomedical Engineering

    Directory of Open Access Journals (Sweden)

    Wojasiński Michal

    2014-06-01

    Full Text Available Comparative statistical analysis of the infiuence of processing parameters, for electrospinning (ES and solution blow spinning (SBS processes, on nanofibrous poly(L-lactic acid (PLLA material morphology and average fiber diameter was conducted in order to identify the key processing parameter for tailoring the product properties. Further, a comparative preliminary biocompatibility evaluation was performed. Based on Design of Experiment (DOE principles, analysis of standard effects of voltage, air pressure, solution feed rate and concentration, on nanofibers average diameter was performed with the Pareto’s charts and the best fitted surface charts. Nanofibers were analyzed by scanning electron microscopy (SEM. The preliminary biocompatibility comparative tests were performed based on SEM microphotographs of CP5 cells cultured on materials derived from ES and SBS. Polymer solution concentration was identified as the key parameter infiuencing morphology and dimensions of nanofibrous mat produced from both techniques. In both cases, when polymer concentration increases the average fiber diameter increase. The preliminary biocompatibility test suggests that nanofibers produced by ES as well as SBS are suitable as the biomedical engineering scaffold material.

  20. Blue foot: a second case of "tattoo blow-out" pigment spread successfully treated with the QS-Nd:YAG laser.

    Science.gov (United States)

    Khetarpal, Shilpi; Molenda, Matthew; Seiger, Eric; Pui, John; Obagi, Suzan

    2010-11-01

    The "tattoo blow-out" phenomenon occurs when tattoo pigments spread outside the border of a tattoo. It is thought to occur when ink is injected too deeply. A healthy 36-year-old female presented to a dermatologist with diffuse spread of tattoo pigment outside the original tattoo that occurred within one day of the placement of a professional tattoo on the dorsum of her foot. The patient was seeking treatment six weeks after the tattoo was placed because she thought the discoloration would improve or resolve on its own, but it worsened. Two punch biopsies were obtained for histology. The biopsy results confirmed granular black pigment consistent with a tattoo in the dermis and subcutaneous fat. The location of pigment was deeper than expected. Due to the success of the QS-Nd:YAG laser in a prior patient, the same treatment was recommended for this patient. The patient received nine laser sessions using the Q-switched laser at 1064 nm, 4 mm, 10 Hz, with gradually increasing energy from 4.5 to 6.0 J/cm2. The pigment outside of the original tattoo borders faded and is barely perceptible. It is important that physicians be made aware of tattoo complications so they can advise patients in regards to the associated risks.

  1. 连续管管-管对接自动焊电弧偏吹现象的探讨%Discussion on Partial Arc Blow Phenomenon During Continuous Pipe-pipe Butt Welding

    Institute of Scientific and Technical Information of China (English)

    王维亮; 石凯; 刘彦明; 张伟妮

    2011-01-01

    In all-position automatic TIG butt welding for coiled tubing, arc blowing phenomenon often occurs. The analysis show that the main reasons for partial arc blow are small line energy, wire unstable, ground connection uncorrection, poor weld shape, edge preparationing unstandard, convection and other inappropriate welding parameters.The measures for avoiding or reducing the arc blowing partial are put forward.%在连续管全位置自动TIG对接焊中,经常会出现电弧偏吹现象.分析表明,引起电弧偏吹的主要原因有小线能量、送丝不稳定、地线连接不正确、焊道成型差、坡口加工不规范、热对流、焊接工艺参数不合适等.根据分析,提出了避免或减小电弧偏吹的措施.

  2. Plant Practice of Copper Oxygen Enrichment Side-Blowing Bath Smelting Process%铜富氧侧吹熔池熔炼的生产实践

    Institute of Scientific and Technical Information of China (English)

    葛晓鸣; 王举良

    2011-01-01

    The chemical composition of slag from oxygen enrichment side-blowing bath smelting process ( OES-BBSP) was confirmed according to the slag composition of Ausmelt furnace, Isaac furnace and Mitsubishi furnace. The problems which occurred during OESBBSP practice included high monomer sulfur content in waste gas, large vibration in furnace body and waste heat boiler, serious accretion in ascent stage and radiation area of waste heat boiler, condensation acid emerged in waste gas, lessening copper recovery due to a larger amount of smoke dust. With the effort of two years' improvement, the daily processing amount of copper concentrate, blister copper output , power and coal consumption, comprehensive energy consumption and production cost all met the design requirements.%根据奥斯麦特炉、艾萨炉、三菱炉的熔炼炉渣的化学成分,确定了富氧侧吹熔池熔炼炉渣的化学成分.富氧侧吹熔池熔炼炉投产过程中出现的问题主要有:烟气中单体硫含量高、炉体和余热锅炉振动较大、余热锅炉上升段和辐射区炉结较重、烟气产生冷凝酸、烟尘量较大降低了铜直收率和铜回收率.经过两年的改进,日处理铜精矿量、粗铜日产量、电单耗、煤单耗、综合能耗和生产成本均达到设计要求.

  3. PET/PEN瓶注拉吹成型工艺研究%Study on Injection-Stretch-Blow Forming Process for PET/PEN Bottle

    Institute of Scientific and Technical Information of China (English)

    董海东

    2011-01-01

    The Moldflow software was used to analyze the injection molding process of a 2-cavity hot runner injection mould for PET/PEN bottle-blank. The mold filling, flowing and cooling processes were visually simulated and the parameters under the conditions of the molding process were obtained. It predicted the potential defects of plastic parts during forming process. The aim was to optimize the cooling channels' diameter,layout and gating system size to propose a better injection scheme;then high-quality bottle-blank was to be injected and finally PET/PEN bottle was made though stretch-blow molding process. Thus it could ensure the even-distributed thickness of the bottle and make it a qualified bottle.%利用Moldflow软件模拟分析了一模两腔PET/PEN瓶坯的注射成型过程,预测塑件成型过程中可能出现的缺陷,优化冷却水道直径、布局和浇注系统尺寸,提出优化的注射成型方案,然后利用注塑机和PET/PEN瓶坯模具注射成型高质量的瓶坯,再利用吹瓶机等设备拉伸-吹塑成型PET/PEN瓶,这样可确保成型瓶子的厚度均匀分布,以生产合格的PET/PEN瓶.

  4. Tensile Properties and Fracture Behavior of Aluminum Alloy Foam Fabricated from Die Castings without Using Blowing Agent by Friction Stir Processing Route

    Directory of Open Access Journals (Sweden)

    Yoshihiko Hangai

    2014-03-01

    Full Text Available Al foam has been used in a wide range of applications owing to its light weight, high energy absorption and high sound insulation. One of the promising processes for fabricating Al foam involves the use of a foamable precursor. In this study, ADC12 Al foams with porosities of 67%–78% were fabricated from Al alloy die castings without using a blowing agent by the friction stir processing route. The pore structure and tensile properties of the ADC12 foams were investigated and compared with those of commercially available ALPORAS. From X-ray computed tomography (X-ray CT observations of the pore structure of ADC12 foams, it was found that they have smaller pores with a narrower distribution than those in ALPORAS. Tensile tests on the ADC12 foams indicated that as their porosity increased, the tensile strength and tensile strain decreased, with strong relation between the porosity, tensile strength, and tensile strain. ADC12 foams exhibited brittle fracture, whereas ALPORAS exhibited ductile fracture, which is due to the nature of the Al alloy used as the base material of the foams. By image-based finite element (FE analysis using X-ray CT images corresponding to the tensile tests on ADC12 foams, it was shown that the fracture path of ADC12 foams observed in tensile tests and the regions of high stress obtained from FE analysis correspond to each other. Therefore, it is considered that the fracture behavior of ADC12 foams in relation to their pore structure distribution can be investigated by image-based FE analysis.

  5. Answer (in part) blowing in the wind. Comment on "Liberating Lévy walk research from the shackles of optimal foraging" by A. Reynolds

    Science.gov (United States)

    Cheng, Ken

    2015-09-01

    In a perspective in this issue based on thorough review, Andy Reynolds [1] tackles the issue of how the by now ubiquitously found Lévy walks can be generated, by animals, by organisms other than animals, and other forms of life below the level of organisms, such as cells. The answer comes not in a single whole cloth, but rather in a patchwork of generating factors. Lévy-like movements arise in objects blowing in the wind, or from travelers encountering turbulence in the seas or being repelled by boundaries. A variety of desiderata in movements, not related to achieving optimal foraging, may also engender Lévy-like movements. These include avoiding other organisms or not crossing one's traveled path. Adding to that plethora are ways in which variations on the theme of garden-variety random walks can at least approach a Lévy walk, if not capturing the mathematical form perfectly. Such variations include executing random walks on multiple scales, a strategy exhibited by desert ants [2,3], mussels [4], and quite likely extant hunter-gatherer humans as well [5]. It is possible that fossil tracks over 50 million years old also show this strategy, as the curve fitting with multiple random walks, characterized by multiple exponential distributions, is as good or better than curve fits having the power-law distribution characteristic of Lévy walks [6]. Another variation is to have a random walk search whose scale is expanding over time. In great detail and based on extensive literature - the review has over 200 references - a range of other ways in which Lévy-like movements might come about are also discussed.

  6. Sugar Blowing-induced Porous Cobalt Phosphide/nitrogen-doped Carbon Nanostructures With Enhanced Electrochemical Oxidation Performance Towards Water And Other Small Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Chengzhou; Fu, Shaofang; Xu, Bo; Song, Junhua; Shi, Qiurong; Engelhard, Mark H.; Li, Xiaolin; Beckman, Scott P.; Sun, Junming; Du, Dan; Lin, Yuehe

    2017-09-06

    Finely controlled synthesis of high active and robust nonprecious metal catalysts with excellent catalytic efficiency in oxygen evolution reaction (OER) is extremely vital for making the water splitting process more energy-efficient and economical. Among these noble metal-free catalysts, transition-metal-based nanomaterials are considered as one of the most promising OER catalysts due to their relatively low-cost intrinsic activities, high abundance and diversity in terms of structure and morphology. In this work, we reported a facile sugar-blowing technique and low-temperature phosphorization to generate 3D self-supported metal involved carbon nanostructures, which termed as Co2P@Co/nitrogen-doped carbon (Co2P@Co/N-C). By capitalizing on the 3D porous nanostructures with high surface area, generously dispersed active sites, the intimate interaction between active sites and 3D N-doped carbon, the resultant Co2P@Co/N-C exhibited satisfying OER performance superior to CoO@Co/N-C, delivering 10 mA cm-2 at overpotential of 0.32 V. It is noting that in contrast to the substantial current density loss of RuO2, Co2P@Co/N-C showed much enhanced catalytic activity during the stability test and the 1.8-fold increase in current density was observed after stability test. Furthermore, the obtained Co2P@Co/N-C can also be served as an excellent nonprecious metal catalyst for methanol and glucose electrooxidation in alkaline media, further extending their potential applications.

  7. Neuroanatomy of pars intercerebralis neurons with special reference to their connections with neurons immunoreactive for pigment-dispersing factor in the blow fly Protophormia terraenovae.

    Science.gov (United States)

    Yasuyama, Kouji; Hase, Hiroaki; Shiga, Sakiko

    2015-10-01

    Input regions of pars intercerebralis (PI) neurons are examined by confocal and electron microscopies with special reference to their connections with neurons immunoreactive for pigment-dispersing factor (PDF) in the blow fly, Protophormia terraenovae. PI neurons are a prerequisite for ovarian development under long-day conditions. Backfills from the cardiac recurrent nerve after severance of the posterior lateral tracts labeled thin fibers derived from the PI neurons in the superior medial protocerebrum. These PI fibers were mainly synapsin-negative and postsynaptic to unknown varicose profiles containing dense-core vesicles. Backfilled fibers in the periesophageal neuropils, derived from the PI neurons or neurons with somata in the subesophageal zone, were varicose and some were synapsin-positive. Electron microscopy revealed the presence of both presynaptic and postsynaptic sites in backfilled fibers in the periesophageal neuropils. Many PDF-immunoreactive varicosities were found in the superior medial and lateral protocerebrum and double-labeling showed that 60-88 % of PDF-immunoreactive varicosities were also synapsin-immunoreactive. Double-labeling with the backfills and PDF immunocytochemistry showed that the PI fibers and PDF-immunoreactive varicosities were located close to each other in the superior medial protocerebrum. Results of triple-labeling of PI neurons, PDF-immunoreactive neurons and synapsin-immunoreactive terminals demonstrated that the synapsin-positive PDF-immunoreactive varicosities contacted the PI fibers. These data suggest that PI neurons receive synaptic contacts from PDF-immunoreactive fibers, which are derived from circadian clock neurons, of small ventral lateral neurons (previously called OL2) or posterior dorsal (PD) neurons with somata in the pars lateralis.

  8. Study on Flow Field of Air Jet from Dual Slot Die in Melt Blowing Process%熔喷双槽形喷嘴气体射流流场初探

    Institute of Scientific and Technical Information of China (English)

    陈廷

    2000-01-01

    In the melt blowing nonwoven process, the air jet draws the polymer melts into microfibers. Study on the flow field of the air jet is very important to the study on the air drag mathematical model of melt blowing. The flow field of the air jet from dual slot die in melt blowing process can be considered as the synthesis of two plane jets. The properties of vortex pair and the possibility of substituting jet with vortex pair are studied according to the nature of single vortex. The results show that the velocity distributions of these two flows have the same tendency and these two flows have similar velocity distributions near the axis of spinneret. So it is feasible to substitute jet with vortex pair. Then the two jets are substituted with two vortex pairs separately. As a result, the synthesis of two jets can be realized. The formula of the air velocity distribution after the synthesis of two jets is developed. The computing results of this formula tally with the experiment data well. The formula is introduced into the air drag mathematical model of melt blowing. By using this formula the model prediction of fiber diameter coincides with that using the empirical formula put forward by Harpham and Shambaugh. The results show the formula of air velocity distribution developed by substituting jet with vortex pair can describe the flow field of the air jet from dual slot die in melt blowing process and can be used to consummate the air drag mathematical model of melt blowing.%在熔喷非织造布加工中,气体射流作为工作介质使聚合物熔体实现拉伸,气体射流流场的研究对熔喷气流拉抻数学模型研究非常重要。熔喷双槽形喷嘴形成的流场可以看作两股平面射流的合成。从单个点涡的性质出发,研究了涡偶的性质和涡偶代替射流的可行性。研究表明,在喷丝孔轴线附近,涡偶和射流的速度分布趋势相同,且有比较相近的速度分布,

  9. Spatial and Temporal Patterns of Blowing Snow Flux and Related Near-Surface Atmospheric Processes over Antarctica (2001-2011) from the Modèle Atmosphérique Régionale (MAR), Assessed With In Situ and Satellite Data

    Science.gov (United States)

    Datta, Rajashree; Tedesco, Marco; Fettweis, Xavier; Gallee, Hubert; Booth, James

    2015-04-01

    The effects of blowing snow (both erosion and sublimation) have a substantial impact on thermodynamic processes on the Antarctic Ice sheet and are a significant source of uncertainty in surface mass balance estimates. In order to capture effects specific to blowing snow at the continental scale, two versions of the model Modèle Atmosphérique Régionale (MAR) RCM have been run at a 50 km resolution over Antarctica for the period 2000-2011. The two MAR configurations are identical except for the implementation of blowing snow dynamics. The model is forced at the boundaries with 6-hourly reanalysis data provided by the European Centre for Medium-Range Weather Forecasts (ECMWF). The differences in surface and atmospheric outputs between the models can highlight the cumulative effects of blowing snow. Due to the difficulty of obtaining reliable large-scale measurements of blowing snow phenomena directly, comparisons of near-surface atmospheric variables between model outputs and satellite as well as in-situ data are necessary to assess the success of the blowing snow physics implemented in the model. For the purposes of assessment, we will use available surface temperature and pressure data from Automatic Weather Stations as well as radiosonde data at the ice sheet margins (made available by the University of Wisconsin-Madison). Additionally, satellite data at multiple atmospheric levels will be provided from the Atmospheric Infrared Sounder (available from NASA Goddard and the Jet Propulsion Labs). Finally, Empirical Orthogonal Function (EOF) analysis will be employed to find the most prominent spatio-temporal patterns of blowing snow flux with the seasonal and decadal trend removed. Model output composites of anomalies for the time series produced can suggest the large-scale climate dynamics which contribute to prominent patterns of blowing snow flux. Spatial trends of correlations between model output and satellite/in situ during these time-series should help to

  10. 双底吹对CAS钢包弱搅拌区混匀效果的改善%Improvement on the Mixing Effect in Low-intensity Stirring Area for CAS Ladle by Double-nozzles Bottom Blowing Technology

    Institute of Scientific and Technical Information of China (English)

    周萌; 何平

    2011-01-01

    Based on a water model with the size of one fifth of the real CAS ladle, the improvement of the mixing effect in CAS-OB process using double-nozzles bottom blowing technology was researched by analyzing the flow field and determining the mixing time. Results show that double-nozzles bottom blowing technology could greatly reduce the mixing time, also could change the flow field in the low-intensity stirring area of ladle and improve the mixing effect in the middle and lower part of ladle. The experimental formula for expressing the effect of bottom blowing flow rate Q and depth of inserting snorkel H on mixing time( T-T0——T0=0. 59Q-0.74 ( H—HL) 0.52) is obtained by free factors analysis.%按照1:5相似比建立CAS钢包模型,通过片光源拍照观察流场和电导率仪测定混匀时间,研究双底吹技术对CAS钢包内弱搅拌区混匀特性的改善情况.结果表明双底吹技术能较大程度降低钢包混匀时间,改善弱搅拌区的流场特点,提高钢包中下部的混匀效果.通过无因次分析,得出辅吹气流量Q和浸罩插入深度H对混匀时间影响程度的经验公式:T-T0/T0=0.59Q-0.74(H/HL)0.52.

  11. Using isotopes of dissolved inorganic carbon species and water to separate sources of recharge in a cave spring, northwestern Arkansas, USA Blowing Spring Cave

    Science.gov (United States)

    Knierim, Katherine Joy; Pollock, Erik; Hays, Phillip D.

    2013-01-01

    Blowing Spring Cave in northwestern Arkansas is representative of cave systems in the karst of the Ozark Plateaus, and stable isotopes of water (δ18O and δ2H) and inorganic carbon (δ13C) were used to quantify soil-water, bedrock-matrix water, and precipitation contributions to cave-spring flow during storm events to understand controls on cave water quality. Water samples from recharge-zone soils and the cave were collected from March to May 2012 to implement a multicomponent hydrograph separation approach using δ18O and δ2H of water and dissolved inorganic carbon (δ13C–DIC). During baseflow, median δ2H and δ18O compositions were –41.6‰ and –6.2‰ for soil water and were –37.2‰ and –5.9‰ for cave water, respectively. Median DIC concentrations for soil and cave waters were 1.8 mg/L and 25.0 mg/L, respectively, and median δ13C–DIC compositions were –19.9‰ and –14.3‰, respectively. During a March storm event, 12.2 cm of precipitation fell over 82 h and discharge increased from 0.01 to 0.59 m3/s. The isotopic composition of precipitation varied throughout the storm event because of rainout, a change of 50‰ and 10‰ for δ2H and δ18O was observed, respectively. Although, at the spring, δ2H and δ18O only changed by approximately 3‰ and 1‰, respectively. The isotopic compositions of precipitation and pre-event (i.e., soil and bedrock matrix) water were isotopically similar and the two-component hydrograph separation was inaccurate, either overestimating (>100%) or underestimating (<0%) the precipitation contribution to the spring. During the storm event, spring DIC and δ13C–DIC decreased to a minimum of 8.6 mg/L and –16.2‰, respectively. If the contribution from precipitation was assumed to be zero, soil water was found to contribute between 23 to 72% of the total volume of discharge. Although the assumption of negligible contributions from precipitation is unrealistic, especially in karst systems where rapid flow

  12. Culture Shock!! "Lesson" the Blow.

    Science.gov (United States)

    Duffin, Ken

    1996-01-01

    Designing, developing, and implementing an electronic document management system involves preparation. Areas to consider when facilitating technological change include staff input and business and customer needs and wants. Further discussion addresses value assessment of document type, providing a pilot system for staff experiment and practice,…

  13. Culture Shock!! "Lesson" the Blow.

    Science.gov (United States)

    Duffin, Ken

    1996-01-01

    Designing, developing, and implementing an electronic document management system involves preparation. Areas to consider when facilitating technological change include staff input and business and customer needs and wants. Further discussion addresses value assessment of document type, providing a pilot system for staff experiment and practice,…

  14. Blowing-machine representation of various meteorological situations for the study of rejection into the atmosphere; Essais de representation en soufflerie des diverses situations meteorologiques pour l'etude des rejets dans l'atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Chassany, J.Ph. [CEA Marcoule, Centre de Production de Plutonium, 30 (France)

    1964-07-01

    A stratified blowing-machine has been built making it possible to introduce into the tests a vertical temperature gradient. The similitude conditions have been examined. The development tests have made it possible to observe and to film the shape of the smoke pall emitted by a chimney in different cases. Stationary waves have been obtained in steady state conditions and the cross-section of the pall has also been studied. It appears that certain diffusion studies justify the use of a stratified blowing-machine. (author) [French] Une soufflerie stratifiee permettant d'introduire dans les experimentations le gradient vertical de la temperature a ete realisee. Les conditions de similitude ont ete examinees. Des essais de mise au point ont permis d'observer et de filmer l'allure du panache de fumee emis par une cheminee dans differents cas. La formation d'ondes stationnaires en regime stable a ete obtenue et la section droite du panache a ete egalement etudiee. Il apparait que certaines etudes de diffusion doivent justifier l'emploi d'une soufflerie stratifiee. (auteur)

  15. 降压吹扫技术在某核电站二回路冲管中的应用%Application of Burst-blowing Technique in Pipe Flushing of Steam System Secondary Loop of Nuclear Power Units

    Institute of Scientific and Technical Information of China (English)

    俞长宏

    2016-01-01

    The paper describes the application procedures of burst-blowing technique in pipe flushing of secondary loopsteam system of nuclear power units. The steam pipe purging was analyzed in consideration of purging parameter selection, purging method determination, and preparation and precautions before purging. An idea was presented that the purging parameters could be selected through theoretical calculation, therefore to reduce steam consumption enhance purging efficiency. Check, for the future of such steam pipe blowing significance.%本文简述了降压吹扫技术在某核电机组二回路蒸汽系统冲管中的应用。从吹扫参数的计算、吹扫方法的选择、吹扫准备和吹扫时的有关注意事项等方面对蒸汽管道的吹扫进行了分析,提出通过理论计算作为确定吹扫参数的依据,以降低吹扫的蒸汽消耗量、提高吹扫效率,该蒸汽系统管道吹扫试验的成功对后续同类型核电站的蒸汽管道的吹扫具有借鉴意义。

  16. Experimental study of effects of multi-winglets and tip blowing upon wingtip vortex%组合小翼和翼梢喷流对翼尖涡的影响实验研究

    Institute of Scientific and Technical Information of China (English)

    杨可; 黄浩; 徐胜金

    2014-01-01

    The effects of multi-winglets and wingtip blowing on the wing tip vortex are exper-imentally studied.On the basis of those results,a wing tip vortex control strategy which com-bines multi-winglets and tip blowing is proposed and justified.The experiments have been con-ducted at a low speed wind tunnel.The basic wing model is a rectangular NACA 0015 airfoil. Reynolds number (Re)defined by the chord length of wing and the free flow speed is 5.3×104 . The blowing coefficient (Cμ)defined by the momentum ratio of blowing to free flow is 0.017. The results show that the multi-winglets divide the wing tip vortex into several co-rotating vorti-ces which decreases the effect of the downwash flow generated by wingtip vortex,and thus im-prove the quality of the local flow.The lift coefficient increases forα>4°.The maximum lift co-efficient increases up to 1 2 .3%.Blowing strengthens the “wandering”of vortex core to change the position of the tip vortex.Blowing suppresses the formation of the wingtip vortex to some ex-tent.The joint control strategies have achieved a well control effect,meanwhile,the blowing en-hances the interaction of the co-rotating vortices.The peak of mean instantaneous vorticity is de-creased by 37% compared with the individual “+0-”multi-winglets configuration,and by 79%compared with the basic wing.The control effect of the joint strategy is subjected to whether the blowing could enhance the interaction of the co-rotating vortices or not.The moving direction of wingtip vortex also has a substantial influence on the control effects.%对翼梢组合小翼构型和翼梢喷流控制翼尖涡进行了实验研究,在此基础上,提出组合小翼与翼梢喷流联合控制翼尖涡的方法,并对翼尖涡的控制效果进行了实验研究。实验在一低速直流式风洞中进行,基本模型为NACA0015二元截尖翼型,基于弦长和自由来流速度定义的雷诺数Re=5.3×104,喷流系数(喷流与自

  17. Global Existence and Blow-up for a System of Nonlocal Wave Equations%一个局部波动方程组的解的全局存在性与爆破

    Institute of Scientific and Technical Information of China (English)

    邓铿

    2005-01-01

    我们研究初始值问题(e)u1/(e)t2=(e)2u1/(e)x2+‖u2(·,t)‖p, (e)2u2/(e)t2=(e)2u2/(e)x2+‖u1(·,t)‖q,-∞0,u1(x,0)=f1(x), (e)u1/(e)t(x,0)=g1(x),u2(x,0)=f2(x), (e)u2/(e)t(x,0)=g2(x),- ∞0,u1(x,0)=f1(x), (e)u1/(e)t(x,0)=g1(x),u2(x,0)=f2(x), (e)u2/(e)t(x,0)=g2(x),- ∞blow-up of solutions,and we present the growth rates at blow-up.

  18. An assessment of potential degradation products in the gas-phase reactions of alternative fluorocarbons in the troposphere

    Science.gov (United States)

    Niki, Hiromi

    1990-01-01

    Tropospheric chemical transformations of alternative hydrofluorocarbons (HCF's) and hydrochlorofluorocarbons (HCFC's) are governed by hydroxyl radical initiated oxidation processes, which are likely to be analogous to those known for alkanes and chloroalkanes. A schematic diagram is used to illustrate plausible reaction mechanisms for their atmospheric degradation, where R, R', and R'' denote the F- and/or Cl-substituted alkyl groups derived from HCF's and HCFC's subsequent th the initial H atom abstraction by HO radicals. At present, virtually no kinetic data exist for the majority of these reactions, particularly for those involving RO. Potential degradation intermediates and final products include a large variety of fluorine- and/or chlorine-containing carbonyls, acids, peroxy acids, alcohols, hydrogen peroxides, nitrates and peroxy nitrates, as summarized in the attached table. Probably atmospheric lifetimes of these compounds were also estimated. For some carbonyl and nitrate products shown in this table, there seem to be no significant gas-phase removal mechanisms. Further chemical kinetics and photochemical data are needed to quantitatively assess the atmospheric fate of HCF's and HCFC's, and of the degradation products postulated in this report.

  19. 膜鼓气/吸收法提溴连续吸收过程%Continues bromine absorption with membrane air-blowing/absorption process

    Institute of Scientific and Technical Information of China (English)

    高启君; 吴丹; 武春瑞; 陈华艳; 贾悦; 王暄; 吕晓龙

    2012-01-01

    以开发节能高效的新型提溴工艺为目的,设计了以中空纤维疏水膜作为布气装置的膜鼓气/吸收(MA-B/A)法连续吸收过程.压缩空气经过布气装置以微小气泡的形式分别进入串联的各级鼓气膜组件,与料液形成对流传质.空气流夹带料液中Br2所形成的空气/溴气混合气透过PVDF疏水膜组件的膜孔与吸收液反应,生成溴的化合物,实现对溴的连续吸收.考察了吸收池液位高度、吸收液流量、浓度、pH、温度、吸收段膜壁厚与组件结构等参数对膜吸收过程性能的影响.实验得到了MA-B/A法连续吸收过程的最佳参数条件.当膜丝厚度为0.15 mm,组件为海藻型,吸收池液位高度为1.5m,流量为0.5L·h-1,浓度为0.10 mol·L-1,pH为6~7,温度为70℃时,溴的脱除率为82.0%,回收率为76.3%,吸收率高达93.1%.%Aimed at developing new energy-efficient technology for bromine extraction, continuous bromine absorption in membrane air-blowing/absorption (MA-B/A) process was designed, where hydrophobic polyvinylidene fluoride (PVDF) hollow fiber membranes were used as aeration configurations. The compressed air was blown out of the aeration configurations (U-type PVDF membrane modules) in the form of small air bubbles, flowed into each membrane module in series connection, and contacted with the liquid (simulated sea water). The air flow made of air and bromine passed the hollow fiber hydrophobic membranes and reacted with absorption liquid to produce bromine compound. It is a continuous bromine extraction process from the liquid. The effects of operation conditions, such as the liquid height in absorption cell, flow rate, concentration, pH value, temperature of absorption solution, the thickness of membranes and the structure of modules, on the absorption process were investigated. The optimal parameters for the continuous bromine absorption with MA-B/A process were obtained. The experimental results show that bromine

  20. Effects of Preform Size on the Thickness Distribution of Stretch-Blow PET Molded Bottle%瓶坯尺寸对拉伸吹塑成型PET瓶壁厚分布的影响

    Institute of Scientific and Technical Information of China (English)

    周烨; 辛勇

    2014-01-01

    通过对多个瓶坯的拉吹成型过程进行模拟分析,预测出不同尺寸的瓶坯所成型的PET瓶壁厚分布,并分析比较瓶坯尺寸对制品壁厚分布的影响。结果表明,瓶坯尺寸对于拉吹成型PET瓶的壁厚均匀性有较大影响,其中瓶坯局部厚度及瓶坯高度是主要影响因素。瓶坯整体壁厚对PET瓶轴向壁厚分布影响较小。PET瓶(不考虑体积时)最优瓶坯高度受瓶坯壁厚影响不大,采用有限元建模(FEM)仿真试验进行模拟分析可得到瓶坯最优高度取值范围。通过模拟计算和对瓶坯进行优化设计,可显著提高吹塑成型PET瓶的壁厚均匀性,且有助于PET瓶轻量化设计。%The size distribution of the wall thickness of PET bottle molded by its preform with different sizes was predicted through the simulation analysis of stretch-blow molding process of multiple performing. The effect of preform sizes on the thickness distribution was analyzed as well. The results show that the size of stretch-blow molding preform of PET bottles have a greater impact on the wall thickness uniformity of products, the preform thickness and partial height are the main factor. The impact of the overall thickness of preform on the uniformity of axial wall thickness distribution of PET bottles is relatively small. The optimal height of PET bottle preform, regardless of volume is little affected by the perform wall thickness. The optimal height value range of bottle preform is available by the FEM simulation experiment for simulation analysis. The simulation and optimization design for preform can significantly improve the thickness uniformity of blow molding PET bottle, and contributes to the lightweight design of PET bottles as well.

  1. 40 CFR 82.19 - Apportionment of baseline consumption allowances for class II controlled substances.

    Science.gov (United States)

    2010-07-01

    ... HCFC-22 45,979 R-Lines HCFC-22 63,172 Saez Distributors HCFC-22 37,936 Solvay Fluorides HCFC-22 413,509 HCFC-141b 3,940,115 Solvay Solexis HCFC-142b 3,047,386 Tulstar Products HCFC-141b 89,913 HCFC-123 34...

  2. 具非局部源项的抛物系统解的整体存在与爆破%Global Existence and Blow Up for a Nonlocal Parabolic System

    Institute of Scientific and Technical Information of China (English)

    凌征球; 冯和英; 庞国萍

    2012-01-01

    考虑一个具有非局部源项的抛物系统非负解的整体存在与爆破问题,通过使用上下解技术,建立了系统的临界指数,而且,相关的分类是最优与最完全的.%This paper investigates the blow-up and global existence of nonnegative solutions to the parabolic system with nonlocal sourcesu(1)=△u+ || uυ ||p(α),υ(1)=△υ+|| uυ ||qβ,(x,t)∈ Ω×(0,T),subject to null Dirichlet boundary conditions.By using the super- and sub-solution techniques,the critical exponent of the system is determined.Furthermore,the related classifications for the parameters in the model are optimal and complete.

  3. 具任意正初始能量的记忆Mindlin-Timoshenko梁方程解的爆破%Blow up for Mindlin-Timoshenko Beam Equation with Memory and Arbitrary Positive Initial Energy

    Institute of Scientific and Technical Information of China (English)

    闫德明; 张桂霞

    2016-01-01

    Concerning one-dimensional Mindlin-Timoshenko model for beam with linear damping and memory terms. By the modified convexity method, a blow-up result for the solution to the Mindlin-Timoshenko system is ob-tained under arbitrary positive initial energy and appropriate initial datum.%研究了具记忆项的Mindlin-Timoshenko梁方程初边值问题解的爆破性。利用改进的凸性方法给出了具任意正初始能量和适当的初始条件下,Mindlin-Timoshenko梁方程初边值问题解的爆破性条件。

  4. Physical Simulation for the Mixing Properties in Side-bottom Blowing RH Vacuum Refining Process%侧底复吹RH真空精炼中均混特性的物理模型研究

    Institute of Scientific and Technical Information of China (English)

    刘政稳; 李晨光; 韩继标; 雷洪

    2014-01-01

    基于相似原理,建立了几何相似比为1:5的水模型,对RH精炼过程钢液循环流动行为进行研究。考察了提升气体流量、真空度、不同吹气方式以及不同形状的浸渍管对混匀时间的影响规律。结果表明:均混时间随吹气量增大先减小后增大,随真空度增大而减小。在相同吹气流量下,单独采用侧底复吹方式或单独采用椭圆形浸渍管,均混时间减小。%Based on the similarity principle, a water modeling with the scale of 1:5 was developed to study the mixing property during RH vacuum refining. The effects of lifting gas flow rate, vacuum degree, blowing mode and snorkel form on mixing time in RH degasser have been studied. The results show that the mixing time first decreases then increases with the increasing lifting gas flow rate and decreases with the increasing vacuum degree. On the condition of same lifting gas flow rate, the mixing time in traditional RH degasser is larger than in RH degasser with side-bottom blowing or ellipse snorkels.

  5. CFD simulation and optimization of airflow field in industrial tunnel dryer with different blowing designs%不同进风方案下隧道烘干窑热风流场CFD模拟和优化

    Institute of Scientific and Technical Information of China (English)

    师建芳; 吴中华; 刘清; 娄正; 赵玉强; 朱明

    2014-01-01

    隧道烘干窑内同一横截面的热风均匀性影响着物料干燥均匀性和产品质量,而烘干窑入口风速分布直接影响着窑内热风流场的均匀分布。为了解决单一风机直进风隧道烘干窑存在的风速不均匀问题,提出了多种进风结构设想,并利用计算流体力学方法对实际生产的隧道窑进风流场进行数值模拟,研究3种不同的进风方案(4风机、6风机和9风机)对隧道窑内热风流场均匀性的影响。模拟结果表明:6风机方案下隧道窑入口处进风均匀,热风扩散距离短,窑内热风流场整体均匀性较佳,综合性价比最高。研究结果为隧道窑入口进风的设计提供参考。%The tunnel dryers with direct blowing are widely applied to dry agricultural products in Chinese rural area. While in practice, the existing single fan blowing designs were found to cause a non-uniform gas velocity distribution inside the tunnel, which results in a non-homogeneous drying quality of the dried product. To address this problem, a multiple fans blowing design concept was proposed in this paper and its feasibility was evaluated by using the computational fluid dynamics (CFD) modeling method. In this paper, the CFD model was developed to simulate the cold flow field inside the tunnel dryer and thus the drying process was ignored at the present stage. The self-developed CFD model consisted of governing equations and suitable boundary conditions. The governing equations comprised of the mass, momentum conservation ones, the K-epison turbulent ones. The boundary conditions were set according to the actual operation conditions of the tunnel dryer and included the velocity inlet, pressure outlet, and non-slip boundary ones. The mathematical model was solved using a commercial CFD software-Fluent 6.3. The flow field inside an industrial tunnel dryer with a single fan blowing used for the drying of cowpeas was measured experimentally and simulated

  6. Effect of blowing agents and process technology on morphology and dimensional stability of BR/SBR/NR foams%不同发泡剂及工艺条件对BR/SBR/NR发泡材料相结构及尺寸稳定性的影响

    Institute of Scientific and Technical Information of China (English)

    王旭; 常素芹; 冯钠; 戚晓霞

    2013-01-01

    分别采用一段和两段模压法制备了以顺丁橡胶(BR)/丁苯橡胶(SBR)/天然橡胶(NR)为基体的橡胶发泡材料,研究了三种化学发泡剂N,N’-二甲基戊次甲基四胺(H)、4,4'-氧代双(苯磺酰肼)(OBSH)以及H/OBSH(质量比1:1)复配对发泡及硫化特性的影响,以及3种发泡剂和2种成型工艺对收缩率及相结构的影响.结果表明,发泡剂H对硫化性能影响最大,含发泡剂H的混炼胶在分解过程中释放的热量最多;加入3种发泡剂都具有一种较大的泡孔镶嵌在较小的泡孔丛中的泡孔形态;密度和线收缩率均随着时间的增加而增加,经H/OBSH复配的发泡剂更适合该体系成型,材料线收缩率均比单独使用H和OBSH小,两段模压法可以有效地提高发泡材料的尺寸稳定性,收缩率降低至3.88%,同时发泡剂使用率最多可提高31.67%.%The blends of 1,4-cis polybutadiene rubbers(BR), styrene-butadiene rubber(SBR) ,and natural rubber (NR) foams were prepared by one-stage and/or two-stage compression molding techniques. The effects of blowing agent H,OBSH and H/OBSH(mass ratio 1:1) Don the vulcanization and foaming characteristics of the rubber foams were investigated. In addition, the effects of the three blowing agents and the two compression molding techniques on the shrinkage and morphology were also studied. The results showed that the rubber had a great influence on the vulcanization and foaming characteristic with blowing agent H, and the gross rubber including of blowing agent H released the maxium heat quantity. The foam articles have the large cells inlay among the small cells with the three blowing agents. The density and shrinkage of BR/SBR/NR foams were increasing with time delaying. The blowing agent H/OBSH was suitable for the system to shape, and shrinkage of BR/SBR/NR foams was lower with blowing agent H/OBSH than those of only filling to blowing agent H and OB-SH. The two-stage compression molding could improve on

  7. CALCULATION AND EXPERIMENTAL ESTIMATION OF RESULTS OF ELECTRO-THERMAL ACTION OF RATIONED BY THE INTERNATIONAL STANDARD IEC 62305-1-2010 IMPULSE CURRENT OF SHORT BLOW OF ARTIFICIAL LIGHTNING ON THE THIN-WALLED COVERAGE FROM STAINLESS STEEL

    Directory of Open Access Journals (Sweden)

    M. I. Baranov

    2017-03-01

    Full Text Available Purpose. Calculation and experimental researches of electro-thermal resistibility of the pre-production thin-walled sheet models of outward roof of height technical buildings from stainless steel are easily soiled 12Х18Н10Т to direct action on them rationed by the International Standard IEC 62305-1-2010 aperiodic impulse of current of short bow of artificial lightning of temporal form 10/350 μs with the proper admittances on his peak-temporal parameters (PTP. Methodology. Electrophysics bases of technique of high voltage and large impulsive currents (LIC, and also scientific and technical bases of planning of high-voltage impulsive devices and measuring methods in them LIC with followings below extreme PTP: amplitude of impulse of current of ImL=200 кА (with admittance ±10 %; integral of action of impulse of current of JL=10·106 A2·s (with admittance ±35 %; %; duration of wavefront current of T1=10 μs (with admittance ±20 %; time, proper amplitude of impulse of current of ImL, tmL≤24 μs (with admittance ±20 %; duration of flowing of impulse of current of T2=350 μs (with admittance ±10 %. Results. The results of evaluation calculation and experimental researches of electro-thermal resistibility of the indicated pre-production sheet models are resulted measuring in the plan of 0,5 x 0,5 m from stainless steel are easily soiled the 12Х18Н10Т thickness of 1 mm to action on them of aperiodic impulse of current of short blow of artificial lightning with rationed PTP on the requirements of the International Standard IEC 62305-1-2010. In high current experiments amplitude of ImL of the aperiodic rationed impulse of current of artificial lightning of temporal form of T1/T2=15 μs/315 μs changed in the range of (100-184 кА. The integral of action of JL of impulse of current for I-IV of levels of protection of lightning of technical objects (TO numeral made from 2,32·106 А2·s to 7,88·106 А2·s, and the flowing through the

  8. 潜艇高压气吹除主压载水舱过程的数值模拟%Numerical simulation on compressed gas blowing ballast tank of submarine

    Institute of Scientific and Technical Information of China (English)

    张建华; 胡坤; 刘常波

    2015-01-01

    采用结构化六面体网格对主压载水舱内部流场进行离散化,基于FLUENT流体计算软件,应用VOF两相流模型,对10 m及20 m水深时高压气吹除主压载水舱过程进行了数值模拟,研究了气液两相界面的形成及生长过程,深入分析了水舱排水速率的变化规律,并针对压载水的残留现象提出了实际操艇过程中需要注意的问题。仿真结果与现有文献中实体模型的实验结果吻合较好,均揭示了吹除过程中水舱内部压力及排水速率的波动现象,验证了数值模拟方法的准确性和有效性。为与实际情况相符,还提出了针对入口及出口边界条件的改进方案。%The inner fluid domain of the ballast tank for computing was dispersed and meshed by applying the structured hexahedral grid, and by using the VOF two-phase flow model, the process of high compressed gas blowing ballast tank while at 10 m and 20 m depth under water was numerically simulated based on computational fluid dynamics package FLUENT. The research studied the forming and developing process of the gas-water two-phase interface was studied, the draining rule of the ballast tank was analysed, and the attention issues in the process of practically steering submarine aiming at the remanet ballast water were indicated. The simulation results match the model experiment results of the existing literatures very well, and for both the results indicating the undulation phenomenon of the interior pressure of the tank and the draining velocity in the process of blowing, the veracity and validity of the numerical simulation is validat-ed. For matching the actual situation, the amelioration schemes of the inlet and outlet boundary conditions were given.

  9. PET吹灌旋一体机及其在环保型轻量瓶装水生产线中的应用%The Application of the Blow-Fill-Cap BFC-Block in Bottled Water Production Line of Environmentally Friendly and Light-weight-situation

    Institute of Scientific and Technical Information of China (English)

    朱建锋; 张洁生

    2013-01-01

    The article describes the structure and composition of the Blow-Fill-Cap BFC-Block and process,explaining the necessity and significance of the environment-friendly light flask,to further illustrate the application of the Blow-Fill-Cap BFC-Block in bottled water production line of environmentally friendly lightweight-situation .%介绍了吹灌旋一体机的主要结构及其组成和工艺流程,同时说明环保型轻量瓶技术产生的必要性和意义,进一步说明吹灌旋一体机在环保型轻量瓶装水生产线上应用情况.

  10. Comment on "Chebyshev finite difference method for the effects of variable viscosity and variable thermal conductivity on heat transfer to a micro-polar fluid from a non-isothemal stretching sheet with suction and blowing," by S.N. Odda and A.M. Farhan

    CERN Document Server

    Pantokratoras, A

    2007-01-01

    In the paper [Chaos, Solitons & Fractals, 2006, vol. 30, pp. 851-858]the authors treat the boundary layer flow of a micropolar fluid along a horizontal flat plate with blowing or suction. The fluid viscosity and thermal conductivity are assumed functions of temperature. The boundary layer equations are transformed into ordinary ones and subsequently are solved using the Chebyshev finite difference method. However, there are some deficiencies and errors in this paper.

  11. Blow-up Mechanism of Classical Solutions to Goursat Problem for Quasilinear Hyperbolic Systems%一阶拟线性双曲型方程组Goursat问题经典解的破裂机制

    Institute of Scientific and Technical Information of China (English)

    刘存明

    2012-01-01

    Under the assumptions that the quasilinear hyperbolic system is not weakly linearly degenerate and the boundary functions given on the characteristic boundaries possess small C1 norms and certain decaying properties,by using the characteristic method and the decomposition for waves,we obtain the blow-up mechanism and the asymptotic behavior of the life-span of the C1 solution to the Goursat problem.%对一阶拟线性双曲型方程组的Goursat问题,利用特征线方法及波分解公式,在方程组不是弱线性退化的假设下,当特征边界上给出的边界函数C1范数充分小、且满足一定衰减性时,得到其C1解的破裂机制及关于生命跨度的渐近估计.

  12. 高铜铅精矿富氧底吹工业实践%Industrial Practice of Rich Oxygen Bottom Blowing Process of Smelting High Copper Content of Lead Concentrate

    Institute of Scientific and Technical Information of China (English)

    陈学兴; 欧阳坤

    2014-01-01

    A lead factory had smelted a batch of high copper content of lead concentrate , through two months of industrial practice , high copper content of lead concentrate had certain influence to the produc-tion of bottom blowing furnace and fuming furnace . The industrial test results showed that copper can be enriched in the crude lead and matte , the copper content of crude lead can reach more than 10 percent , the copper content of matte can reach more than 40 percent , the copper content of slag can be controlled under 0 .65 percent , and the recovery rate of copper can reach more than 90 percent .%某铅厂处理了一批高铜铅精矿,通过2个月的工业生产,入炉原料含铜高对底吹炉、烟化炉生产有一定影响,整个工业试验结果表明,铜可以在粗铅及锍中富集,粗铅含铜可达10%以上,锍含铜可达40%以上,弃渣含铜可控制在0.65%以下,铜的回收率可达90%。

  13. 凯瑟琳·曼斯菲尔德《大风吹》中的叙事聚焦研究%Focalization in Katherine Mansfield's "The Wind Blows"

    Institute of Scientific and Technical Information of China (English)

    银洁

    2012-01-01

    Katherine Mansfield is a famous British short story writer in the twentieth century and her contribution mainly lies in the dedicate use of modern narrative techniques, such as focalization. Based on Genette's narratology theory, this paper analyzes the focalization in "The Wind Blows" of Katherine Mansfield and reveals the inner relation between focalization and character and theme.%凯瑟琳·曼斯菲尔德是英国二十世纪著名的短篇小说家,她对短篇小说发展的突出贡献主要体现在现代主义叙事技巧的巧妙运用,比如聚焦。本文以热奈特的叙事理论为基础,对凯瑟琳·曼斯菲尔德的短篇小说《大风吹》的叙事聚焦进行探究,旨在揭示聚焦与人物及主题的内在关系。

  14. Analysis and Research of Scientific and Technological Innovation on the Green Technology and Its Application Technology of the Multi-Layer Co-Extrusion Blow Plastic Molding Machine%多层共挤中空塑料成型机绿色技术的科技创新及其应用技术的分析研究

    Institute of Scientific and Technical Information of China (English)

    张友根; 冯刚; 张朝阁; 齐继宝

    2013-01-01

    Put out the science technology system and green design principles of the multi-layer coextruded blow plastic molding machine green technology.Research the scientific and technological innovation and its development main points on the green technology that the mold,plastics extrusion,clamping mechanism,power driven,heat system,blow,control components and systems of the co-extrusion of multilayer co-extruded blow plastic molding machine in to improve energy efficiency,reduce resource consumption,energy saving and processing,cleaner production,energy and material back regeneration applications.Analysis of the points of the research and development of green technology and scientific development of intelligent multi-layer co-extruded blow molding machine.Brief introduction of the green molding technology progress on Achieve extrusion blow molded containers "reality needs" and "potential demand" resourcesaving and improved barrier properties and environmental of the multi-layer co-extruded blow plastic molding machine.Studied the multi-layer co-extrusion plastic blow molding machines of green technology science and technology innovation promote the greening of hollow container processing technology progress.%提出了多层共挤中空塑料成型机绿色技术的科学技术体系和绿色设计原则,研究了多层共挤中空塑料成型机的共挤机头、塑化挤出、合模机构、动力驱动、加热、吹塑、控制等部件及系统在提高能源利用率、减少资源消耗、节能加工、清洁生产、能量和回料再生应用等方面的绿色技术的科技创新及研发要点,论述了智能化实现多层共挤中空成型机的绿色技术科学化发展的研发要点,浅述了多层共挤中空塑料成型机实现挤出中空成型容器“现实需求”和“潜在需求”实现资源节约型、提高阻隔性和环保性等绿色成型加工技术化的进展,研究了多层共挤塑料中空成型机绿色技术的科技创新推

  15. Analysis of Chinese emissions trends of major halocarbons in monitoring the impacts of the Montreal Protocol

    Science.gov (United States)

    Li, S.; Park, S.; Park, M.; Kim, J.; Muhle, J.; Fang, X.; Stohl, A.; Weiss, R. F.; Kim, K.

    2013-12-01

    In this study we estimate the emission rates of anthropogenic halocarbons, which include CFC-11, CFC-12, HCFC-22, HCFC-141b, HCFC-142b, HFC-23, HFC-134a, HFC-32, HFC-125 and HFC-152a for China during the period of 2008 and 2012 using an interspecies correlation method (Kim et al., 2010; Li et al., 2011), which is a unique 'top-down' approach using in situ high-precision measurements at Gosan, a remote station on Jeju Island, Korea. Mixing ratios of ambient halocarbons have been measured every two hours using a cryogenic pre-concentration system coupled with gas chromatograph and mass selective detector (GC-MSD) as part of the Advanced Global Atmospheric Gases Experiment network. We first separated air-mass segments originating from China using a back-trajectory analysis to identify Chinese emission from the observations, and found that the mixing ratios of most of compounds presented significant correlations against those of HCFC-22. Based on the correlations, we analyzed emission strengths of individual compounds, which correspond to their slopes against HCFC-22 since the slope can be a useful proxy to demonstrate their emission trends with an assumption of relatively constant emission of HCFC-22 during the analysis period. The analysis showed about 14% increase in the emissions strengths of CFCs (mainly due to CFC-12) between 2008 and 2012 in China. Interestingly, HCFC-141b and HCFC-142b that are commonly known to be used for foam blowing agents revealed opposite trends in their emission strengths: ca. 48% increase of HCFC-141b versus ca. 22% decrease of HCFC-142b, suggesting the possibility of other major sources in case of China. The emission strengths of HFCs have been increasing due to significant emissions of HFC-32, HFC-125 and HFC-134a during the analysis period. However, HFC-23 which is a well-known byproduct of HCFC-22 production processes, showed decrease by about 22% in the emission strength. Reduction in HFC-23 emissions is most likely due to the

  16. Haies et boisements pare-congères : de la théorie à la pratique Hedges and afforestration to prevent damage from blowing snow: from theory to practice

    Directory of Open Access Journals (Sweden)

    Florence Naaim-Bouvet, Sylvie Monier et Sylvie Ougier

    2010-09-01

    Full Text Available Lorsque la neige et le vent s'associent, ils créent des congères qui vont gêner la circulation sur les routes et les chemins de montagne. Pour lutter contre ce problème, l'implantation de haies et de boisements apparait comme une solution écologique et durable. Quels sont les principes de fonctionnement ? Où et comment implanter ces haies pour constituer un barrage efficace à la neige ? Quelles essences choisir et quel entretien cela suppose-t-il ? Cet article fait le point sur les connaissances disponibles afin de répondre aux préoccupations des gestionnaires.Blowing and drifting snow can generate snowdrifts on roads and railways. This is an important issue for instance in the Massif Central (France where limited snowfalls on vast areas can locally lead to huge snow accumulations. This problem is not new and prevention measures were designed and tested as early as the end of the 19th century. However, the development of efficient snow clearing vehicles in the second half of the 20th century led to some decrease of research efforts (mostly a trial and error approach on traditional prevention measures such as afforestration and hedges. Nevertheless, the renewed interest in ecological engineering, dating from the early 90s has yielded to new research efforts on that topic, even though such measures are not effective on short term. Currently, bioengineering tallies meet the requirements of sustainable development and of long term management, accordingly. In this context, this paper aims at giving a new vision of hedges and afforestration, taken as protection measures against snowdrifting, through the eyes of a fluid mechanics researcher, a forest engineer and a territories manager. The principles of action, setting and species choice are presented through case studies with emphasis on difficulties related to land property and long and short-term maintenance.

  17. Attenuation of fluorocarbons released from foam insulation in landfills

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Dote, Yukata; Fredenslund, Anders Michael

    2007-01-01

    Chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and hydrofluorocarbons (HFCs) have been used as blowing agents (BAs) for foam insulation in home appliances and building materials, which after the end of their useful life are disposed of in landfills. The objective of this project...... in any of the experiments within a run time of up to 200 days. The obtained degradation rate coefficients were used as input for an extended version of an existing landfill fate model incorporating a time dependent BA release from co-disposed foam insulation waste. Predictions with the model indicate...

  18. 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%.

  19. Replacement Technologies for Precision Cleaning of Aerospace Hardware for Propellant Service

    Science.gov (United States)

    Beeson, Harold; Kirsch, Mike; Hornung, Steven; Biesinger, Paul

    1997-01-01

    The NASA White Sands Test Facility (WSTF) is developing cleaning and verification processes to replace currently used chlorofluorocarbon-l13- (CFC-113-) based processes. The processes being evaluated include both aqueous- and solvent-based techniques. Replacement technologies are being investigated for aerospace hardware and for gauges and instrumentation. This paper includes the findings of investigations of aqueous cleaning and verification of aerospace hardware using known contaminants, such as hydraulic fluid and commonly used oils. The results correlate nonvolatile residue with CFC 113. The studies also include enhancements to aqueous sampling for organic and particulate contamination. Although aqueous alternatives have been identified for several processes, a need still exists for nonaqueous solvent cleaning, such as the cleaning and cleanliness verification of gauges used for oxygen service. The cleaning effectiveness of tetrachloroethylene (PCE), trichloroethylene (TCE), ethanol, hydrochlorofluorocarbon 225 (HCFC 225), HCFC 141b, HFE 7100(R), and Vertrel MCA(R) was evaluated using aerospace gauges and precision instruments and then compared to the cleaning effectiveness of CFC 113. Solvents considered for use in oxygen systems were also tested for oxygen compatibility using high-pressure oxygen autogenous ignition and liquid oxygen mechanical impact testing.

  20. Study on Flow Ratio of Blowing to Drawing of Rotational Jet Shield Ventilation at Tunneling Working Face%机掘工作面旋转射流屏蔽通风吹吸流量比研究

    Institute of Scientific and Technical Information of China (English)

    刘荣华; 王鹏飞; 张登春; 陈世强

    2012-01-01

    为改善机掘工作面作业环境,提高通风控尘效果,采用旋转射流屏蔽通风技术实现对机掘工作面粉尘的有效控制.利用Fluent计算流体力学(CFD)软件,对该通风方式下不同吹吸流量比情况开展数值模拟,并进行相关试验验证.研究结果表明:就所研究的机掘工作面旋转射流屏蔽通风系统而言,合适的吹吸流量比范围是0.8~1.4,当吹吸流量比为1.0时控尘效果最佳.在工作面实际应用中,通常将吹吸流量比设定在1.2 ~1.4范围,既能保证掘进巷道有足够的新风量,防止瓦斯超限,又能获得较好的控尘效果.%For the sake of improving the working environment at tunneling working face and enhancing the ventilation effect, the rotational jet shield ventilation was introduced. Using CFD software Fluent, the rotational jet shield ventilation under different flow ratios of blowing to drawing was investigated by numerical simulation, and related experiment was carried out to verify the simulation. The results show that the relatively suitable range of the flow ratio is from 0. 8 to 1. 4 for the system of rotational jet shield vetilation of this study, and the best dust control effect can be obtained with the flow ratio of 1.0. In the actual application, the flow ratio is usually in the range of 1.2 to 1.4, which not only ensures sufficient fresh air to prevent gas overrunning but also can obtain a good dust control effect.