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

Science.gov (United States)

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

2018-03-01

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

75 FR 57669 - Mandatory Reporting of Greenhouse Gases

Science.gov (United States)

2010-09-22

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

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

Directory of Open Access Journals (Sweden)

P. G. Simmonds

2018-03-01

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

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...

The phase-in and phase-out of European emissions of HCFC-141b and HCFC-142b under the Montreal Protocol: Evidence from observations at Mace Head, Ireland and Jungfraujoch, Switzerland from 1994 to 2004

Science.gov (United States)

Derwent, R. G.; Simmonds, P. G.; Greally, B. R.; O'doherty, S.; McCulloch, A.; Manning, A.; Reimann, S.; Folini, D.; Vollmer, M. K.

The mixing ratios of HCFC-141b (1,1-dichlorofluoroethane) and HCFC-142b (1-chloro-1,1-difluoroethane) have been rising steadily in baseline air at Mace Head, Ireland over the 10-year period from 1994 to 2004. These HCFCs are widely used replacements for the chlorofluorocarbons phased out under the Montreal Protocol and its subsequent amendments. Analysis of the HCFC content of regionally-polluted air arriving at Mace Head from the European continent shows that European emissions reached a peak during 2000-2001 and have declined subsequently, following the phase-out in their usage. European emissions of HCFC-141b have been further constrained by observations at the High-Alpine Jungfraujoch site. The reductions are consistent with the phase-out of HCFC production and use from the year 2001 onwards mandated by European regulations designed to exceed the requirements of the Montreal Protocol.

Performance of R433A for replacing HCFC22 used in residential air-conditioners and heat pumps

International Nuclear Information System (INIS)

Park, Ki-Jung; Shim, Yun-Bo; Jung, Dongsoo

2008-01-01

In this study, thermodynamic performance of R433A and HCFC22 is measured in a heat pump bench tester under air-conditioning and heat pumping conditions. R433A has no ozone depletion potential and very low greenhouse warming potential of less than 5. R433A also offers a similar vapor pressure to HCFC22 for possible 'drop-in' replacement. Test results showed that the coefficient of performance of R433A is 4.9-7.6% higher than that of HCFC22 while the capacity of R433A is 1.0-5.5% lower than that of HCFC22 for both conditions. The compressor discharge temperature of R433A is 22.6-27.9 deg. C lower than that of HCFC22 while the amount of charge for R433A is 57.0-57.7% lower than that of HCFC22 due to its low density. Overall, R433A is a good long term environmentally friendly alternative to replace HCFC22 in residential air-conditioners and heat pumps due to its excellent thermodynamic and environmental properties with minor adjustments

The disappearance of HCFC 22 and the search for the ideal refrigerant; La disparition du HCFC-22 et le recherche du refrigerant ideal

Energy Technology Data Exchange (ETDEWEB)

Dumas, C. [Ville de Montreal, PQ (Canada). Direction des Immeubles Gestion de l' Energie et du Genie Climatique

2003-03-01

The City of Montreal, Quebec is searching for the optimum refrigerant, and has determined that ammonia, carbon dioxide, hydrocarbons and refrigerant-mixes in the 400 series are to be considered for general refrigeration and in skating rinks in the next years. The refrigerants of the 400 series contribute to the greenhouse effect and it is not possible to utilize them in sunk type systems. The City of Montreal has 12 per cent of ice surfaces in Quebec. The Montreal Protocol, a United Nations document calls for the gradual elimination of the refrigerant monochlorodifluoromethane (HCFC 22) starting in 2004 and that none will be made after 2020 in order to protect the ozone layer. In this document, the author discussed the following topics: (1) supply problems, regulations, international index used to compare refrigeration systems, (2) the origin of refrigerants available on the market and why the chemical industry is incapable of producing the miracle refrigerant, and (3) a proposal for an action plan for the control and the reduction of HCFC 22 leaks, the replacement of entire refrigeration systems and the preparation for the period following the availability of HCFC 22. The author offered twelve conclusions. 10 refs., 9 figs.

Two-phase flow characteristics of HFC and HCFC fluid

International Nuclear Information System (INIS)

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

1998-01-01

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

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

Science.gov (United States)

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

2014-01-01

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

HCFC-142b emissions in China: An inventory for 2000 to 2050 basing on bottom-up and top-down methods

Science.gov (United States)

Han, Jiarui; Li, Li; Su, Shenshen; Hu, Jianxin; Wu, Jing; Wu, Yusheng; Fang, Xuekun

2014-05-01

1-Chloro-1,1-difluoroethane (HCFC-142b) is both ozone depleting substance included in the Montreal Protocol on Substances that Deplete the Ozone Layer (Montreal Protocol) and potent greenhouse gas with high global warming potential. As one of the major HCFC-142b consumption and production countries in the world, China's control action will contribute to both mitigating climate change and protecting ozone layer. Estimating China's HCFC-142b emission is a crucial step for understanding its emission status, drawing up phasing-out plan and evaluating mitigation effect. Both the bottom-up and top-down method were adopted in this research to estimate HCFC-142b emissions from China. Results basing on different methods were compared to test the effectiveness of two methods and validate inventory's reliability. Firstly, a national bottom-up emission inventory of HCFC-142b for China during 2000-2012 was established based on the 2006 IPCC Guidelines for National Greenhouse Gas Inventories and the Montreal Protocol, showing that in contrast to the downward trend revealed by existing results, HCFC-142b emissions kept increasing from 0.1 kt/yr in 2000 to the peak of 14.4 kt/yr in 2012. Meanwhile a top-down emission estimation was also developed using interspecies correlation method. By correlating atmospheric mixing ratio data of HCFC-142b and reference substance HCFC-22 sampled from four representative cities (Beijing, Hangzhou, Lanzhou and Guangzhou, for northern, eastern, western and southern China, respectively), China's HCFC-142b emission in 2012 was calculated. It was 16.24(13.90-18.58) kt, equivalent to 1.06 kt ODP and 37 Tg CO2-eq, taking up 9.78% (ODP) of total HCFCs emission in China or 30.5% of global HCFC-142b emission. This result was 12.7% higher than that in bottom-up inventory. Possible explanations were discussed. The consistency of two results lend credit to methods effectiveness and results reliability. Finally, future HCFC-142b emission was projected to 2050

CFC alternatives for thermal insulation foams

Energy Technology Data Exchange (ETDEWEB)

Shankland, I.R. (Allied-Signal Inc., Buffalo, NY (US))

1990-03-01

Low density polymeric foam materials expanded with chlorofluorocarbon (CFC) blowing agents have found widespread use as highly efficient thermal insulation materials in the construction, refrigeration appliance and transportation industries. The advent of regulations which are reducing the production and consumption of the fully halogenated CFCs for environmental reasons has prompted the development of environmentally acceptable substitutes for the CFC blowing agents. This paper summarizes the physical properties and performance of the leading alternatives for CFC-11, which is used to expand rigid polyurethane and polyisocyanurate foams, and the leading alternatives for CFC-12 which is used to expand extruded polystyrene board foam. Although the alternatives, HCFC-123 and HCFC-14lb for CFC-11 and HCFC142b and HCFC-124 for CFC-12, are not perfect matches from the performance viewpoint, they represent the optimum choice given the constraints on environmental acceptability, toxicity, flammability and performance. (author).

New High-Resolution Absorption Cross-Section Measurements of HCFC-142B in the Mid-Ir

Science.gov (United States)

Le Bris, Karine; Strong, Kimberly; Melo, Stella

2009-06-01

HCFC-142b (1-chloro-1,1-difluoroethane) is a temporary substitute for ozone-depleting chlorofluorocarbons (CFCs). However, due to its high absorption cross-sections in the mid-IR, HCFC-142b is also a highly potent greenhouse gas, now detectable from space by satellite missions. So far, the accuracy of the retrieval has been limited by the lack of reference data in a range of temperatures compatible with atmospheric observations. We present new absorption cross section measurements of HCFC-142b at high-resolution (0.02 cm^{-1}) from 223 K to 283 K in the 600 cm^{-1}- 4000 cm^{-1} spectral window. The composite spectra are calculated for each temperature from a set of acquisitions at different pressures by Fourier transform spectroscopy.

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.

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.

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

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.

Hydrocarbons as Refrigerants―A Review

Directory of Open Access Journals (Sweden)

J. H. KOH

2017-08-01

Full Text Available Refrigerants used in air conditioning and refrigeration (AC&R indusries have come full circle since the beginning of the industrialrevolution. With concern on issues relating to the environment such as the global warming and climate change issues, we should finda better alternative than to continue using these refrigerants that cause global warming and ozone depletion. AC&R industryplayers have blended in by introducing some new equipment and components that are specificallydesigned for hydrocarbon (HC use. Mostnew refrigerators sold in Malaysia are already equipped with isobutane [a hydrocarbon designated as R-600a by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE standards]as refrigerants. Malaysia has ratifiedthe Montreal Protocol and targetted a 10% reduction in hydrochlorofluorocarbon(HCFC consumption, beginning 2016 with the banning of 2.5 horsepower (hp and below in air-conditioning (AC equipment to be used. Instead,hydrofluorocarbon(HFC R-410a was introduced as a replacement for HCFC- 22, whereas in other countries this HFC has been phased down. This article was initiated  because of the difficultin findinga replacement for HCFC. Also, the possibilities of using HC as an alternative to replace HCFC insteadof using HFC as a transitional refrigerant in place of HCFC is reviewed in this article. The performance of HC is very similar to HCFC and flmmability issues could be easily overcome with the use of an effectivedesign. Their use could be facilitated with the adaptation of specific standards and properly enacted legislatio

Global HCFC-22 measurements with MIPAS: retrieval, validation, global distribution and its evolution over 2005–2012

Directory of Open Access Journals (Sweden)

M. Chirkov

2016-03-01

Full Text Available We report on HCFC-22 data acquired by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS in the reduced spectral resolution nominal observation mode. The data cover the period from January 2005 to April 2012 and the 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 modelled spectra to the measured limb spectral radiances. 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 rate of linear growth in the lower latitudes lower stratosphere was about 6 to 7 pptv year−1 in the period 2005–2012. The profiles obtained were compared with ACE-FTS satellite data v3.5, as well as with MkIV balloon profiles and 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. MIPAS HCFC-22 time series below 10 km altitude are shown to agree mostly well to corresponding time series of near-surface abundances from the NOAA/ESRL and AGAGE networks, although a more pronounced seasonal cycle is obvious in the satellite data. This is attributed 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 stratospheric

Photodegradation of HCFC-22 Using Microwave Discharge Electrodeless Mercury Lamp with TiO2 Photocatalyst Balls

Directory of Open Access Journals (Sweden)

Seong-Gyu Seo

2014-01-01

Full Text Available The photodegradation of chlorodifluoromethane (HCFC-22 was investigated using microwave/UV/TiO2 photocatalysts hybrid system. The microwave discharge electrodeless mercury lamp (MDEML used in this study showed mainly atomic Hg emission lines at 253.7 nm. The decomposition efficiency of HCFC-22 increased with decreasing inlet concentration and with increasing reactor residence time. The removal efficiency increased with increasing microwave power on every oxygen concentration. The highest degradation efficiency was obtained when both TiO2 balls and MDEML were used.

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

International Nuclear Information System (INIS)

Zhou, Guobing; Zhang, Yufeng

2010-01-01

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.

Thar she blows! A novel method for DNA collection from cetacean blow.

Directory of Open Access Journals (Sweden)

Céline H Frère

Full Text Available BACKGROUND: Molecular tools are now widely used to address crucial management and conservation questions. To date, dart biopsying has been the most commonly used method for collecting genetic data from cetaceans; however, this method has some drawbacks. Dart biopsying is considered inappropriate for young animals and has recently come under scrutiny from ethical boards, conservationists, and the general public. Thus, identifying alternative genetic collection techniques for cetaceans remains a priority, especially for internationally protected species. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we investigated whether blow-sampling, which involves collecting exhalations from the blowholes of cetaceans, could be developed as a new less invasive method for DNA collection. Our current methodology was developed using six bottlenose dolphins, Tursiops truncatus, housed at the National Aquarium, Baltimore (USA, from which we were able to collect both blow and blood samples. For all six individuals, we found that their mitochondrial and microsatellite DNA profile taken from blow, matched their corresponding mitochondrial and microsatellite DNA profile collected from blood. This indicates that blow-sampling is a viable alternative method for DNA collection. CONCLUSION/SIGNIFICANCE: In this study, we show that blow-sampling provides a viable and less invasive method for collection of genetic data, even for small cetaceans. In contrast to dart biopsying, the advantage of this method is that it capitalizes on the natural breathing behaviour of dolphins and can be applied to even very young dolphins. Both biopsy and blow-sampling require close proximity of the boat, but blow-sampling can be achieved when dolphins voluntarily bow-ride and involves no harmful contact.

A water blown urethane insulation for use in cryogenic environments

Science.gov (United States)

Blevins, Elana; Sharpe, Jon

1995-01-01

Thermal Protection Systems (TPS) of NASA's Space Shuttle External Tank include polyurethane and polyisocyanurate modified polyurethane foam insulations. These insulations, currently foamed with CFC 11 blowing agent, serve to maintain cryogenic propellant quality, maintain the external tank structural temperature limits, and minimize the formation of ice and frost that could potentially damage the ceramic insulation on the space shuttle orbiter. During flight the external tank insulations are exposed to mechanical, thermal and acoustical stresses. TPS must pass cryogenic flexure and substrate adhesion tests at -253 C, aerothermal and radiant heating tests at fluxes up to approximately 14 kilowatts per square meter, and thermal conductivity tests at cryogenic and elevated temperatures. Due to environmental concerns, the polyurethane insulation industry and the External Tank Project are tasked with replacing CFC 11. The flight qualification of foam insulations employing HCFC 141b as a foaming agent is currently in progress; HCFC 141b blown insulations are scheduled for production implementation in 1995. Realizing that the second generation HCFC blowing agents are an interim solution, the evaluation of third generation blowing agents with zero ozone depletion potential is underway. NASA's TPS Materials Research Laboratory is evaluating third generation blowing agents in cryogenic insulations for the External Tank; one option being investigated is the use of water as a foaming agent. A dimensionally stable insulation with low friability, good adhesion to cryogenic substrates, and acceptable thermal conductivity has been developed with low viscosity materials that are easily processed in molding applications. The development criteria, statistical experimental approach, and resulting foam properties will be presented.

Effect of mass concentration of composite phase change material CA-DE on HCFC-141b hydrate induction time and system stability

Science.gov (United States)

Li, Juan; Sun, Zhigao; Liu, Chenggang; Zhu, Minggui

2018-03-01

HCFC-141b hydrate is a new type of environment-friendly cold storage medium which may be adopted to balance energy supply and demand, achieve peak load shifting and energy saving, wherein the hydrate induction time and system stability are key factors to promote and realize its application in industrial practice. Based on step cooling curve measurement, two kinds of aliphatic hydrocarbon organics, n-capric acid (CA) and lauryl alcohol (DE), were selected to form composite phase change material and to promote the generation of HCFC-141b hydrate. Five kinds of CA-DE mass concentration were chosen to compare the induction time and hydration system stability. In order to accelerate temperature reduction rate, the metal Cu with high heat conductivity performance was adopted to conduct out the heat generated during phase change. Instability index was introduced to appraise system stability. Experimental results show that phase change temperature and sub-cooling degree of CA-DE is 11.1°C and 3.0°C respectively, which means it is a preferable medium for HCFC-141b hydrate formation. For the experimental hydration systems, segmented emulsification is achieved by special titration manner to avoid rapid layering under static condition. Induction time can achieve up to 23.3min with the densest HCFC-141b hydrate and the lowest instability index, wherein CA-DE mass concentration is 3%.

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.

Results of the Test Program for Replacement of AK-225G Solvent for Cleaning NASA Propulsion Oxygen Systems

Science.gov (United States)

Lowrey, Nikki M.; Mitchell, Mark A.

2016-01-01

Since the 1990's, when the Class I Ozone Depleting Substance (ODS) chlorofluorocarbon-113 (CFC-113) was banned, NASA's propulsion test facilities at Marshall Space Flight Center (MSFC) and Stennis Space Center (SSC) have relied upon the solvent AsahiKlin AK-225 (hydrochlorofluorocarbon-225ca/cb or HCFC-225ca/cb) and, more recently AK-225G (the single isomer form, HCFC-225cb) to safely clean and verify the cleanliness of large scale propulsion oxygen systems. Effective January 1, 2015, the production, import, export, and new use of Class II Ozone Depleting Substances, including AK-225G, was prohibited in the United States by the Clean Air Act. In 2012 through 2014, NASA test labs at MSFC, SSC, and Johnson Space Center's White Sands Test Facility (WSTF) collaborated to seek out, test, and qualify a solvent replacement for AK-225G that is both an effective cleaner and safe for use with oxygen systems. This paper summarizes the tests performed, results, and lessons learned.

Blowing Flap Experiment: PIV Measurements

Science.gov (United States)

Hutcheson, Florence V.; Stead, Daniel J.; Bremmer, David M.

2004-01-01

PIV measurements of the flow in the region of a flap side edge are presented for several 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 flap vortex system. It is concluded that blowing from the top or bottom surfaces of the flap may lead to a reduction of flap side edge noise.

Simulated and experimental performance of split packaged air conditioner using refrigerant HC-290 as a substitute for HCFC-22

International Nuclear Information System (INIS)

Padalkar, Atul S.; Mali, Kundlik V.; Devotta, Sukumar

2014-01-01

This paper discusses the use of propane (HC-290) as a safe and energy efficient alternative to HCFC-22 in a typical split air conditioner with nominal cooling capacities up to 5.1 kW. Initially split air conditioner performance is simulated for cooling capacity, energy efficiency ratio (EER), and refrigerant charge. Tests were conducted for different test cases in a psychrometric test chamber with HCFC-22 and HC-290. The test conditions considered are as per Indian Standards, IS 1391 (1992) Part I. The various parameters considered were based on simulated performance with the objective to achieve maximum EER for the desired cooling capacity. As the flammability is an issue for HC-290, the reduction of HC-290 charge was another objective. Two different types of condensers, first with smaller size tubing and another parallel flow condenser (PFC) or minichannel condenser were used in order to reduce HC-290 charge. For HC-290, the highest EER achieved was 3.7 for cooling capacity 4.90 kW for a refrigerant charge of 360 g. The important safety aspects of using HC-290 in air conditioner are discussed. The refrigerant charge as per EN 378 for different cooling capacities and room sizes is also considered. -- Highlights: • Simulation for performance of split air conditioner has been done using HC-290 as a replacement to HCFC-22. • The safety aspects of HC-290 are discussed when used in split air conditioner. • HC-290 was tested in psychrometric test chamber as per IS 1391 part 1. • With PFC, HC-290 gave highest EER of 3.7 which was 37% higher than that of HCFC-22. • The lowest HC-290 charge used in test was 340 g which is well below LFL

The thermal conductivity of 1-chloro-1,1-difluoroethane (HCFC-142b)

Science.gov (United States)

Sousa, A. T.; Fialho, P. S.; Nieto de Castro, C. A.; Tufeu, R.; Le Neindre, B.

1992-05-01

The thermal conductivity of 1-chloro-1,1-difluoroethane (HCFC-142b) has been measured in the temperature range 290 to 504 K and pressures up to 20 MPa with a concentric-cylinder apparatus operating in a steady-state mode. These temperature and pressure ranges cover all fluid states. The estimated accuracy of the method is about 2%. The density dependence of the thermal conductivity has been studied in the liquid region.

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.

Mechanistic insights aid the search for CFC substitutes: risk assessment of HCFC-123 as an example.

Science.gov (United States)

Jarabek, A M; Fisher, J W; Rubenstein, R; Lipscomb, J C; Williams, R J; Vinegar, A; McDougal, J N

1994-06-01

An international consensus on the need to reduce the use of chlorofluorocarbons (CFCs) and other ozone-depleting gases such as the halons led to the adoptions of the 1987 Montreal Protocol and Title VI of the 1990 Clean Air Act Amendments, "Protecting Stratospheric Ozone." These agreements included major provisions for reducing and eventually phasing out production and use of CFCs and halons as well as advancing the development of replacement chemicals. Because of the ubiquitous use and benefits of CFCs and halons, an expeditious search for safe replacements to meet the legislative deadlines is of critical importance. Toxicity testing and health risk assessment programs were established to evaluate the health and environmental impact of these replacement chemicals. Development and implementation of these programs as well as the structural-activity relationships significant for the development of the replacement chemicals are described below. A dose-response evaluation for the health risk assessment of the replacement chemical HCFC-123 (2,2-dichloro-1,1,1-trifluoroethane) is also presented to show an innovative use of physiologically based pharmacokinetic (PBPK) modeling. This is based on a parallelogram approach using data on the anesthetic gas halothane, a structural analog to HCFC-123. Halothane and HCFC-123 both form the same metabolite, trifluoroacetic acid (TFA), indicative of the same metabolic oxidative pathway attributed to hepatotoxicity. The parallelogram approach demonstrates the application of template model structures and shows how PBPK modeling, together with judicious experimental design, can be used to improve the accuracy of health risk assessment and to decrease the need for extensive laboratory animal testing.

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

Directory of Open Access Journals (Sweden)

M. Zhou

2016-11-01

Full Text Available 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

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.

A new method used to evaluate organic working fluids

International Nuclear Information System (INIS)

Zhang, Xinxin; He, Maogang; Wang, Jingfu

2014-01-01

In this paper, we propose a method named “Weight Classification-Hasse Dominance” to evaluate organic working fluids. This new method combines the advantages of both the method of weight determination and the Hasse Diagram Technique (HDT). It can be used to evaluate the thermodynamic performance, environmental protection indicator, and safety requirement of organic working fluid simultaneously. This evaluation method can offer good reference for working fluid selection. Using this method, the organic working fluids which have been phased out and will be phased out by the Montreal Protocol including CFCs (chlorofluorocarbons), HCFCs (hydrochlorofluorocarbons), and HFCs (hydrofluorocarbons) were evaluated. Moreover, HCs (hydrocarbons) can be considered as a completely different kind of organic working fluid from CFCs, HCFCs, and HFCs according to the comparison based on this new evaluation method. - Highlights: • We propose a new method used to evaluate organic working fluids. • This evaluation method can offer good reference for working fluid selection. • CFC, HCFC, and HFC working fluids were evaluated using this evaluation method. • HC can be considered as a totally different working fluid from CFC, HCFC, and HFC

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.

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.

Whistle-blowing

International Nuclear Information System (INIS)

Fitzgerald, K.

1990-01-01

In this paper five engineers in nuclear power, aerospace, and air-traffic control recount their experiences in following their consciences. Exposing errors or unethical conduct in any occupation is risky, but when engineering judgement is involved, the risks of blowing the whistle acquire an added dimension. A technical decision cannot always be categorized as strictly right or wrong - unlike situations in which an organization is falsifying documents or overcharging for a product. Consequently, the engineer must be convinced of being right and then wait, sometimes years and even decades after lives are lost or millions of dollars are spent, to be proved right or wrong. Frequently, the whistle-blower's career is destroyed in the meantime. In the following cases, which date from the 1970s and 1980s, the whistle-blowers have by now been vindicated to a degree for their actions, though the verdict may not be unanimous. And the careers of the first group may have even benefitted by blowing the whistle

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.”

Use of cooling tower blow down in ethanol fermentation.

Science.gov (United States)

Rajagopalan, N; Singh, V; Panno, B; Wilcoxon, M

2010-01-01

Reducing water consumption in bioethanol production conserves an increasingly scarce natural resource, lowers production costs, and minimizes effluent management issues. The suitability of cooling tower blow down water for reuse in fermentation was investigated as a means to lower water consumption. Extensive chemical characterization of the blow down water revealed low concentrations of toxic elements and total dissolved solids. Fermentation carried out with cooling tower blow down water resulted in similar levels of ethanol and residual glucose as a control study using deionized water. The study noted good tolerance by yeast to the specific scale and corrosion inhibitors found in the cooling tower blow down water. This research indicates that, under appropriate conditions, reuse of blow down water from cooling towers in fermentation is feasible.

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.

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.

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

KAUST Repository

Klein, Christian; Muite, Benson; Roidot, Kristelle

2013-01-01

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.

Final report on CCQM-P151: Halocarbons in dry whole air

Science.gov (United States)

Rhoderick, George; Guenther, Franklin; Duewer, David; Lee, Jeongsoon; Seog Kim, Jin; Hall, Bradley; Weiss, Ray; Harth, Christina; Reimann, Stefan; Vollmer, Martin

2014-01-01

The growing awareness of climate change/global warming and continuing concerns regarding stratospheric ozone depletion will require future measurements and standards for many compounds, in particular halocarbons that are linked to these issues. In order to track and control the emissions of these species globally in the atmosphere, it is necessary to demonstrate measurement equivalence at the highest levels of accuracy for assigned values of standards. This report describes the results of a pilot study between National Metrology Institutes and atmospheric research laboratories for several of the more important halocarbons at atmospheric concentration levels. The comparison includes the chlorofluorocarbons (CFCs) dichlorodifluoromethane (CFC 12), trichlorofluoromethane (CFC 11), and 1,1,2-trichlorotrifluoroethane (CFC 113); the hydrochlorofluorocarbons (HCFCs) chlorodifluoromethane (HCFC 22) and 1-chloro-1,1-difluoroethane (HCFC 142b); and the hydrofluorocarbon (HFC) 1,1,1,2-tetrafluoroethane (HFC 134a), all in a dried whole air sample. The objective of this key comparison is to compare the measurement capabilities of the participants for these halocarbons at trace atmospheric levels. Main text. To reach the main text of this paper, click on Final Report. The final report has been peer-reviewed and approved for publication by the CCQM.

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.

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

Control rod blow out protection system

International Nuclear Information System (INIS)

Dietrich, J.R.; Flinn, W.S.; Groves, M.D.

1979-01-01

An absorber element blow-out protection system for a nuclear reactor having a pressure vessel through which a coolant is circulated. The blow-out protection system includes devices which hydraulically couple groups of guide tubes in which the absorber elements move, the coupling devices limiting coolant lift flow rate to a level commensurate with the raising of individual absorber elements but insufficient to raise a plurality of absorber elements simultaneously

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.

Comparison on Promotion Effect of Various Types of Surfactants on HCFC-141b Hydrate Induction Time

Science.gov (United States)

Li, Juan; Sun, Zhigao; Liu, Chenggang; Zhu, Minggui

2018-03-01

Cold storage in air conditioning based on refrigerant hydrate is a new-type energy saving technology to reduce initial investment and running cost of air conditioning equipments and improve system stability. Refrigerant hydrate is generated under critical temperature and pressure condition, while surfactant is an effective medium to promote its phase equilibrium. In this paper, in order to research such promotion effect, different type of surfactants with unique mechanism, SDS, Tween80 and Span80, n-BA were selected to compare the respective impact on HCFC141b hydrate induction time based on temperature curve. Experimental results showed that no obvious change had been discovered when no surfactant was added into pure water system, which coincided with phase equilibrium diagram of HCFC141b. All the four kinds of surfactants had realized promotion effect to various degrees. For each hydration system, a large gap existed between the longest and the shortest induction time in 6 groups of parallel experiments, meaning relatively poor system stability. Under the combined effect of Tween80 (2wt%), Span80 (0.1wt%) and n-BA (0.1wt%), average and the shortest induction time was 20.9min and 17.5min respectively, corresponding to the best promotion effect.

Exploring Hydrofluorocarbons as Groundwater Age Tracers (Invited)

Science.gov (United States)

Haase, K. B.; Busenberg, E.; Plummer, L. N.; Casile, G.; Sanford, W. E.

2013-12-01

Groundwater dating tracers are an essential tool for analyzing hydrologic conditions in groundwater systems. Commonly used tracers for dating post-1940's groundwater include sulfur hexafluoride (SF6), chlorofluorocarbons (CFCs), 3H-3He, and other isotopic tracers (85Kr, δ2H and δ18O isotopes, etc.). Each tracer carries a corresponding set of advantages and limitations imposed by field, analytical, and interpretive methods. Increasing the number available tracers is appealing, particularly if they possess inert chemical properties and unique temporal emission histories from other tracers. Atmospherically derived halogenated trace gases continue to hold untapped potential for new tracers, as they are generally inert and their emission histories are well documented. SF5CF3, and CFC-13 were previously shown to have application as dating tracers, though their low mixing ratios and low solubility require large amounts of water to be degassed for their quantification. Two related groups of compounds, hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) are hypothesized to be potential age tracers, having similar mixing ratios to the CFCs and relatively high solubility. However, these compounds yield gas chromatography electron capture detector (GC-ECD) responses that are 10-2 -10-5 less than CFC-12, making purge and trap or field stripping GC-ECD approaches impractical. Therefore, in order to use dissolved HCFCs and HFCs as age tracers, different approaches are needed. To solve this problem, we developed an analytical method that uses an atomic emission detector (GC-AED) in place of an ECD to detect fluorinated compounds. In contrast to the ECD, the AED is a universally sensitive, highly linear, elementally specific detector. The new GC-AED system is being used to measure chlorodifluoromethane (HCFC-22), 1,1,1,2-tetrafluoroethane (HFC-134a), and other fluorinated compounds in one liter water samples to study their potential as age dating tracers. HCFC-22 is a

Blow-Up Time for Nonlinear Heat Equations with Transcendental Nonlinearity

Directory of Open Access Journals (Sweden)

Hee Chul Pak

2012-01-01

Full Text Available A blow-up time for nonlinear heat equations with transcendental nonlinearity is investigated. An upper bound of the first blow-up time is presented. It is pointed out that the upper bound of the first blow-up time depends on the support of the initial datum.

Blow Flies Visiting Decaying Alligators: Is Succession Synchronous or Asynchronous?

Directory of Open Access Journals (Sweden)

Mark P. Nelder

2009-01-01

Full Text Available Succession patterns of adult blow flies (Diptera: Calliphoridae on decaying alligators were investigated in Mobile (Ala, USA during August 2002. The most abundant blow fly species visiting the carcasses were Chrysomya rufifacies (Macquart, Cochliomyia macellaria (Fabricus, Chrysomya megacephala (Fabricus, Phormia regina (Meigen, and Lucilia coeruleiviridis (Macquart. Lucilia coeruleiviridis was collected more often during the early stages of decomposition, followed by Chrysomya spp., Cochliomyia macellaria, and Phormia regina in the later stages. Lucilia coeruleiviridis was the only synchronous blow fly on the three carcasses; other blow fly species exhibited only site-specific synchrony. Using dichotomous correlations and analyses of variance, we demonstrated that blow fly-community succession was asynchronous among three alligators; however, Monte Carlo simulations indicate that there was some degree of synchrony between the carcasses.

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...

Rate constant for the reaction of OH with CH3CCl2F (HCFC-141b) determined by relative rate measurements with CH4 and CH3CCl3

Science.gov (United States)

Huder, Karin; Demore, William B.

1993-01-01

Determination of accurate rate constants for OH abstraction is of great importance for the calculation of lifetimes for HCFCs and their impact on the atmosphere. For HCFC-141b there has been some disagreement in the literature for absolute measurements of this rate constant. In the present work rate constant ratios for HCFC-141b were measured at atmospheric pressure in the temperature range of 298-358 K, with CH4 and CH3CCl3 as reference gases. Ozone was photolyzed at 254 nm in the presence of water vapor to produce OH radicals. Relative depletions of 141b and the reference gases were measured by FTIR. Arrhenius expressions for 141b were derived from each reference gas and found to be in good agreement with each other. The combined expression for HCFC-141b which we recommend is 1.4 x 10 exp -12 exp(-1630/T) with k at 298 K being 5.9 x 10 exp -15 cu cm/molec-s. This value is in excellent agreement with the JPL 92-20 recommendation.

Simulation of the Two Stages Stretch-Blow Molding Process: Infrared Heating and Blowing Modeling

International Nuclear Information System (INIS)

Bordival, M.; Schmidt, F. M.; Le Maoult, Y.; Velay, V.

2007-01-01

In the Stretch-Blow Molding (SBM) process, the temperature distribution of the reheated perform affects drastically the blowing kinematic, the bottle thickness distribution, as well as the orientation induced by stretching. Consequently, mechanical and optical properties of the final bottle are closely related to heating conditions. In order to predict the 3D temperature distribution of a rotating preform, numerical software using control-volume method has been developed. Since PET behaves like a semi-transparent medium, the radiative flux absorption was computed using Beer Lambert law. In a second step, 2D axi-symmetric simulations of the SBM have been developed using the finite element package ABAQUS registered . Temperature profiles through the preform wall thickness and along its length were computed and applied as initial condition. Air pressure inside the preform was not considered as an input variable, but was automatically computed using a thermodynamic model. The heat transfer coefficient applied between the mold and the polymer was also measured. Finally, the G'sell law was used for modeling PET behavior. For both heating and blowing stage simulations, a good agreement has been observed with experimental measurements. This work is part of the European project ''APT P ACK'' (Advanced knowledge of Polymer deformation for Tomorrow's PACKaging)

Simulation of the Two Stages Stretch-Blow Molding Process: Infrared Heating and Blowing Modeling

Science.gov (United States)

Bordival, M.; Schmidt, F. M.; Le Maoult, Y.; Velay, V.

2007-05-01

In the Stretch-Blow Molding (SBM) process, the temperature distribution of the reheated perform affects drastically the blowing kinematic, the bottle thickness distribution, as well as the orientation induced by stretching. Consequently, mechanical and optical properties of the final bottle are closely related to heating conditions. In order to predict the 3D temperature distribution of a rotating preform, numerical software using control-volume method has been developed. Since PET behaves like a semi-transparent medium, the radiative flux absorption was computed using Beer Lambert law. In a second step, 2D axi-symmetric simulations of the SBM have been developed using the finite element package ABAQUS®. Temperature profiles through the preform wall thickness and along its length were computed and applied as initial condition. Air pressure inside the preform was not considered as an input variable, but was automatically computed using a thermodynamic model. The heat transfer coefficient applied between the mold and the polymer was also measured. Finally, the G'sell law was used for modeling PET behavior. For both heating and blowing stage simulations, a good agreement has been observed with experimental measurements. This work is part of the European project "APT_PACK" (Advanced knowledge of Polymer deformation for Tomorrow's PACKaging).

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.

Blowing snow detection from ground-based ceilometers : Application to East Antarctica

NARCIS (Netherlands)

Gossart, Alexandra; Souverijns, Niels; Gorodetskaya, Irina V.; Lhermitte, S.L.M.; Lenaerts, Jan T M; Schween, Jan H.; Mangold, Alexander; Laffineur, Quentin; van Lipzig, Nicole P. M.

2017-01-01

Blowing snow impacts Antarctic ice sheet surface mass balance by snow redistribution and sublimation. However, numerical models poorly represent blowing snow processes, while direct observations are limited in space and time. Satellite retrieval of blowing snow is hindered by clouds and only the

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

Directory of Open Access Journals (Sweden)

Sandra Perks

2008-11-01

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.

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.

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.

Matrix isolation infrared spectroscopic and theoretical study of 1,1,1-trifluoro-2-chloroethane (HCFC-133a)

Science.gov (United States)

Rodrigues, Gessenildo Pereira; Lucena, Juracy Régis; Ventura, Elizete; Andrade do Monte, Silmar; Reva, Igor; Fausto, Rui

2013-11-01

The molecular structure and infrared spectrum of the atmospheric pollutant 1,1,1-trifluoro-2-chloroethane (HCFC-133a; CF3CH2Cl) in the ground electronic state were characterized experimentally and theoretically. Excited state calculations (at the CASSCF, MR-CISD, and MR-CISD+Q levels) have also been performed in the range up to ˜9.8 eV. The theoretical calculations show the existence of one (staggered) conformer, which has been identified spectroscopically for the monomeric compound isolated in cryogenic (˜10 K) argon and xenon matrices. The observed infrared spectra of the matrix-isolated HCFC-133a were interpreted with the aid of MP2/aug-cc-pVTZ calculations and normal coordinate analysis, which allowed a detailed assignment of the observed spectra to be carried out, including identification of bands due to different isotopologues (35Cl and 37Cl containing molecules). The calculated energies of the several excited states along with the values of oscillator strengths and previous results obtained for CFCs and HCFCs suggest that the previously reported photolyses of the title compound at 147 and 123.6 nm [T. Ichimura, A. W. Kirk, and E. Tschuikow-Roux, J. Phys. Chem. 81, 1153 (1977)] are likely to be initiated in the n-4s and n-4p Rydberg states, respectively.

Energy and global warming impacts of CFC alternative technologies

International Nuclear Information System (INIS)

Fischer, S.K.; Fairchild, P.D.; Hughes, P.J.

1992-01-01

Chlorofluorocarbons (CFCs) are used in a number of applications, and volumes of CFCs used grew at a tremendous pace during the 1960s and 1970s. However, in the mid-1980s, it was confirmed that these extremely useful chemicals contribute to the destruction of stratospheric ozone. These chemicals are being phased out of use rapidly to protect the ozone layer and it is very important that the replacements for CFSs do not result in a net increase in global warming by introducing less efficient processes that lead to higher energy use and increased carbon dioxide emissions. A study was conducted to identify those alternative chemicals and technologies that could replace CFCs in energy related applications before the year 2000, and to assess the total potential impact of these alternatives on global warming. The analysis for this project included an estimate of the direct effects from the release of blowing agents, refrigerants, and solvents into the atmosphere and the indirect effects in the form of carbon dioxide emissions resulting from energy use for commercial and residential heating and cooling, household and commercial refrigeration, building and automobile air-conditioning, and general metal and electronics solvent cleaning. The discussion in this paper focuses on those aspects of the study relevant to refrigeration and air-conditioning. In general the use of hydrofluorocarbon (HFC) and hydrochlorofluorocarbon (HCFC) alternatives for CFCs lead to large and sometimes dramatic reduction in total equivalent warming impact (TEWI), lifetime equivalent CO 2 emission. Most of the reductions result from decreased direct effects without significant changes in energy use. 3 refs., 3 figs., 1 tab

TEWI Analysis: Its Utility, Its Shortcomings, and Its Results

International Nuclear Information System (INIS)

Baxter, V.D.; Fischer, S.K.; Sand, J.R.

1999-01-01

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

Development and implementation of Intelligent Soot Blowing Optimization System for TNB Janamanjung

Directory of Open Access Journals (Sweden)

Sundaram Taneshwaren

2017-01-01

Full Text Available With an ever increasing demand for energy, Malaysia has become a nation that thrives on solid power generation sector to meet the energy demand and supply market. In a coal fired power plant, soot blowing operation is commonly used as a cleaning mechanism inside the boiler. There are many types of sequence available for this soot blowing operation. Hence, there is no efficient ways in utilizing the soot blowing operation to enhance the efficiency of boiler. Soot blowing optimization requires specific set of data preparation and simulation in order to achieve the best modal. Computational Fluid Dynamics (CFD is used to model a 700MW super-critical boiler, whereby parameters with effect to soot blowing operation is studied. Two different boiler condition is studied to analyze parameters in a clean and faulty boiler. Artificial Neural Network (ANN is used to train neural network modal with back propagation method to determine the best modal that will be used to predict soot blowing operation. Combination of neural network different number of neurons, hidden layers, training algorithm, and training functions is trained to find the modal with lowest error. By improving soot blowing sequence, efficiency of boiler can be improved by providing best parameter and model. This model is then used as a reference for advisory tool whereby a Neural Network Predictive Tool is suggested to the station to predict the soot blowing operation that occurs.

Helical instability in film blowing process: Analogy to buckling instability

Science.gov (United States)

Lee, Joo Sung; Kwon, Ilyoung; Jung, Hyun Wook; Hyun, Jae Chun

2017-12-01

The film blowing process is one of the most important polymer processing operations, widely used for producing bi-axially oriented film products in a single-step process. Among the instabilities observed in this film blowing process, i.e., draw resonance and helical motion occurring on the inflated film bubble, the helical instability is a unique phenomenon portraying the snake-like undulation motion of the bubble, having the period on the order of few seconds. This helical instability in the film blowing process is commonly found at the process conditions of a high blow-up ratio with too low a freezeline position and/or too high extrusion temperature. In this study, employing an analogy to the buckling instability for falling viscous threads, the compressive force caused by the pressure difference between inside and outside of the film bubble is introduced into the simulation model along with the scaling law derived from the force balance between viscous force and centripetal force of the film bubble. The simulation using this model reveals a close agreement with the experimental results of the film blowing process of polyethylene polymers such as low density polyethylene and linear low density polyethylene.

The effects of local blowing perturbations on thermal turbulent structures

Science.gov (United States)

Liu, Can; Araya, Guillermo; Leonardi, Stefano; Castillo, Luciano

2013-11-01

Blowing is an active flow control technique with several industrial applications, particularly in film cooling of turbine blades. In the past, the effects of localized blowing have been mostly analyzed on the velocity field and its influence of the flow parameters and turbulence structures (Krogstad and Kourakine, 2000). However, little literature can be found on the effects of blowing on the coherent thermal structures. In the present study, an incompressible turbulent channel flow with given steady blowing at the wall is simulated via DNS by means of five spanwise holes. The Reynolds number based on the friction velocity and half channel height is approximately Re = 394 and the molecular Prandtl number is Pr = 0.71. Temperature is considered a passive scalar with isothermal conditions at the wall. Different blowing amplitudes and perturbing angles (with respect to the streamwise direction) are applied to find out their effects on the turbulent thermal structures by means of a two-point correlation analysis. In addition, local reduction and increase of drag are connected to vorticity. The corresponding influence of perturbing amplitudes and angles on the energy budget of thermal fluctuations and turbulent Prandtl numbers are also shown and discussed.

New Perspectives on Blowing Snow Transport, Sublimation, and Layer Thermodynamic Structure over Antarctica

Science.gov (United States)

Palm, Steve; Kayetha, Vinay; Yang, Yuekui; Pauly, Rebecca M.

2017-01-01

Blowing snow over Antarctica is a widespread and frequent event. Satellite remote sensing using lidar has shown that blowing snow occurs over 70% of the time over large areas of Antarctica in winter. The transport and sublimation of blowing snow are important terms in the ice sheet mass balance equation and the latter is also an important part of the hydrological cycle. Until now the only way to estimate the magnitude of these processes was through model parameterization. We present a technique that uses direct satellite observations of blowing snow and model (MERRA-2) temperature and humidity fields to compute both transport and sublimation of blowing snow over Antarctica for the period 2006 to 2016. The results show a larger annual continent-wide integrated sublimation than current published estimates and a significant transport of snow from continent to ocean. The talk will also include the lidar backscatter structure of blowing snow layers that often reach heights of 200 to 300 m as well as the first dropsonde measurements of temperature, moisture and wind through blowing snow layers.

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].

Blow-up for a three dimensional Keller-Segel model with consumption of chemoattractant

Science.gov (United States)

Jiang, Jie; Wu, Hao; Zheng, Songmu

2018-04-01

We investigate blow-up properties for the initial-boundary value problem of a Keller-Segel model with consumption of chemoattractant when the spatial dimension is three. Through a kinetic reformulation of the Keller-Segel system, we first derive some higher-order estimates and obtain certain blow-up criteria for the local classical solutions. These blow-up criteria generalize the results in [4,5] from the whole space R3 to the case of bounded smooth domain Ω ⊂R3. Lower global blow-up estimate on ‖ n ‖ L∞ (Ω) is also obtained based on our higher-order estimates. Moreover, we prove local non-degeneracy for blow-up points.

Blowing snow detection in Antarctica, from space borne and ground-based remote sensing

Science.gov (United States)

Gossart, A.; Souverijns, N.; Lhermitte, S.; Lenaerts, J.; Gorodetskaya, I.; Schween, J. H.; Van Lipzig, N. P. M.

2017-12-01

Surface mass balance (SMB) strongly controls spatial and temporal variations in the Antarctic Ice Sheet (AIS) mass balance and its contribution to sea level rise. Currently, the scarcity of observational data and the challenges of climate modelling over the ice sheet limit our understanding of the processes controlling AIS SMB. Particularly, the impact of blowing snow on local SMB is not yet constrained and is subject to large uncertainties. To assess the impact of blowing snow on local SMB, we investigate the attenuated backscatter profiles from ceilometers at two East Antarctic locations in Dronning Maud Land. Ceilometers are robust ground-based remote sensing instruments that yield information on cloud base height and vertical structure, but also provide information on the particles present in the boundary layer. We developed a new algorithm to detect blowing snow (snow particles lifted by the wind from the surface to substantial height) from the ceilometer attenuated backscatter. The algorithm successfully allows to detect strong blowing snow signal from layers thicker than 15 m at the Princess Elisabeth (PE, (72°S, 23°E)) and Neumayer (70°S, 8° W) stations. Applying the algorithm to PE, we retrieve the frequency and annual cycle of blowing snow as well as discriminate between clear sky and overcast conditions during blowing snow. We further apply the blowing snow algorithm at PE to evaluate the blowing snow events detection by satellite imagery (Palm et al., 2011): the near-surface blowing snow layers are apparent in lidar backscatter profiles and enable snowdrift events detection (spatial and temporal frequency, height and optical depth). These data are processed from CALIPSO, at a high resolution (1x1 km digital elevation model). However, the remote sensing detection of blowing snow events by satellite is limited to layers of a minimal thickness of 20-30 m. In addition, thick clouds, mostly occurring during winter storms, can impede drifting snow

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.

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....

Religiosity, Job Status and Whistle-Blowing: Evidence from Micro-Finance Companies

Directory of Open Access Journals (Sweden)

Emmanuel Selase Asamoah

2016-03-01

Full Text Available We investigate the effect of religiosity and job status on whistle-blowing among employees of micro finance companies in Ga-East district of Ghana. The intellectual dimension of religiosity informs and produces high sense of morality in an individual thus influencing whistle-blowing. Additionally, religion create the platform for building belief in certain rules and regulations as right or as wrong. Using quantitative approach for analyzing the effect between independent variables (job status and religiosity on the dependent variable (whistle-blowing, we show that though religiosity and job status can influence whistle-blowing, however in this study, the magnitude is negligible and perhaps other variables in concert with religiosity and job status may influence whistle-blowing activities in an organization. We conclude that that whistleblowing generally in the Ghanaian setting is yet to receive high prominence due to the general belief of lack of protection for persons who come out to expose wrongdoings and the general fear of harassment, victimization and loss of job by the whistle-blower.

Void fraction and interfacial velocity in gas-liquid upward two-phase flow across tube bundles

International Nuclear Information System (INIS)

Ueno, T.; Tomomatsu, K.; Takamatsu, H.; Nishikawa, H.

1997-01-01

Tube failures due to flow-induced vibration are a major problem in heat exchangers and many studies on the problem of such vibration have been carried out so far. Most studies however, have not focused on two-phase flow behavior in tube bundles, but have concentrated mainly on tube vibration behavior like fluid damping, fluid elastic instability and so on. Such studies are not satisfactory for understanding the design of heat exchangers. Tube vibration behavior is very complicated, especially in the case of gas-liquid two-phase flow, so it is necessary to investigate two-phase flow behavior as well as vibration behavior before designing heat exchangers. This paper outlines the main parameters that characterize two-phase behavior, such as void fraction and interfacial velocity. The two-phase flow analyzed here is gas-liquid upward flow across a horizontal tube bundle. The fluids tested were HCFC-123 and steam-water. HCFC-123 stands for Hydrochlorofluorocarbon. Its chemical formula is CHCl 2 CF 3 , which has liquid and gas densities of 1335 and 23.9 kg/m 3 at a pressure of 0.40 MPa and 1252 and 45.7 kg/m 3 at a pressure of 0.76 MPa. The same model tube bundle was used in the two tests covered in this paper, to examine the similarity law of two-phase flow behavior in tube bundles using HCFC-123 and steam-water two-phase flow. We also show numerical simulation results for the two fluid models in this paper. We do not deal with vibration behavior and the relationship between vibration behavior and two-phase flow behavior. (author)

Numerical analysis of an air condenser working with the refrigerant fluid R407C

International Nuclear Information System (INIS)

Aprea, Ciro; Maiorino, Angelo

2007-01-01

As CFC (clorofluorocarbon) and HCFC (hydrochlorofluorocarbon) refrigerants which have been used as refrigerants in a vapour compression refrigeration system were know to provide a principal cause to ozone depletion and global warming, production and use of these refrigerants have been restricted. Therefore, new alternative refrigerants should be searched for, which fit to the requirements in an air conditioner or a heat pump, and refrigerant mixtures which are composed of HFC (hydrofluorocarbon) refrigerants having zero ODP (ozone depletion potential) are now being suggested as drop-in or mid-term replacement. However also these refrigerants, as the CFC and HCFC refrigerants, present a greenhouse effect. The zeotropic mixture designated as R407C (R32/R125/R134a 23/25/52% in mass) represents a substitute of the HCFC22 for high evaporation temperature applications as the air-conditioning. Aim of the paper is a numerical-experimental analysis for an air condenser working with the non azeotropic mixture R407C in steady-state conditions. A homogeneous model for the condensing refrigerant is considered to forecast the performances of the condenser; this model is capable of predicting the distributions of the refrigerant temperature, the velocity, the void fraction, the tube wall temperature and the air temperature along the test condenser. Obviously in the refrigerant de-superheating phase the numerical analysis becomes very simple. A comparison with the measurements on an air condenser mounted in an air channel linked to a vapour compression plant is discussed. The results show that the simplified model provides a reasonable estimation of the steady-state response and that this model is useful to design purposes

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.

Blow up of solutions to ordinary differential equations arising in nonlinear dispersive problems

Directory of Open Access Journals (Sweden)

Milena Dimova

2018-03-01

Full Text Available We study a new class of ordinary differential equations with blow up solutions. Necessary and sufficient conditions for finite blow up time are proved. Based on the new differential equation, a revised version of the concavity method of Levine is proposed. As an application we investigate the non-existence of global solutions to the Cauchy problem of Klein-Gordon, and to the double dispersive equations. We obtain necessary and sufficient condition for finite time blow up with arbitrary positive energy. A very general sufficient condition for blow up is also given.

'Whistle-blowing' and the quandary of policy implementation in Nigeria

African Journals Online (AJOL)

Nigeria as a country has undergone series of economic policies and Programs to bring her economy back on track. These policies range from National Development Plan to the present day whistle-blowing policy. The whistle blowing policy was introduced by the administration of President Buhari in December, 2016, with a ...

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

Thermal large Eddy simulations and experiments in the framework of non-isothermal blowing

International Nuclear Information System (INIS)

Brillant, G.

2004-06-01

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)

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

Numerical and experimental study of blowing jet on a high lift airfoil

Science.gov (United States)

Bobonea, A.; Pricop, M. V.

2013-10-01

Active manipulation of separated flows over airfoils at moderate and high angles of attack in order to improve efficiency or performance has been the focus of a number of numerical and experimental investigations for many years. One of the main methods used in active flow control is the usage of blowing devices with constant and pulsed blowing. Through CFD simulation over a 2D high-lift airfoil, this study is trying to highlight the impact of pulsed blowing over its aerodynamic characteristics. The available wind tunnel data from INCAS low speed facility are also beneficial for the validation of the numerical analysis. This study intends to analyze the impact of the blowing jet velocity and slot geometry on the efficiency of an active flow control.

Field observations of the electrostatic charges of blowing snow in Hokkaido, Japan

Science.gov (United States)

Omiya, S.; Sato, A.

2011-12-01

An electrostatic charge of blowing snow may be a contributing factor in the formation of a snow drift and a snow cornice, and changing of the trajectory of own motion. However, detailed electrification characteristics of blowing snow are not known as there are few reports of charge measurements. We carried out field observations of the electrostatic charges of blowing snow in Tobetsu, Hokkaido, Japan in the mid winter of 2011. An anemovane and a thermohygrometer were used for the meteorological observation. Charge-to-mass ratios of blowing snow were obtained by a Faraday-cage, an electrometer and an electric balance. In this observation period, the air temperature during the blowing snow event was -6.5 to -0.5 degree Celsius. The measured charges in this observation were consistent with the previous studies in sign, which is negative, but they were smaller than the previous one. In most cases, the measured values increased with the temperature decrease, which corresponds with previous studies. However, some results contradicted the tendency, and the maximum value was obtained on the day of the highest air temperature of -0.5 degree Celsius. This discrepancy may be explained from the difference of the snow surface condition on observation day. The day when the maximum value was obtained, the snow surface was covered with old snow, and hard. On the other hand, in many other cases, the snow surface was covered with the fresh snow, and soft. Blowing snow particles on the hard surface can travel longer distance than on the soft one. Therefore, it can be surmised that the hard surface makes the blowing snow particles accumulate a lot of negative charges due to a large number of collisions to the surface. This can be supported by the results of the wind tunnel experiments by Omiya and Sato (2011). By this field observation, it was newly suggested that the electrostatic charge of blowing snow are influenced greatly by the difference of the snow surface condition. REFERENCE

Dynamic shock wave: hammer blow

International Nuclear Information System (INIS)

Lackme, Claude

1978-01-01

The general properties of shocks, their generation and the conditions of reflexion to an interface are dealt with in turn. By then applying these concepts to a liquid column and its environment (wall, free area, closing devices) the hammer blow is presented as being a relatively weak shock [fr

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.

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.

Sounds of Silence: Organisational trust and decisions to blow the whistle

Directory of Open Access Journals (Sweden)

Elli Binikos

2008-11-01

Full Text Available Whistleblowing is a form of pro-social behaviour that occurs when an employee reports organisational wrongdoing to an authority able to implement corrective action. While a number of social factors may infuence an employee’s decision to blow the whistle, very little cognisance is given to the role of organisational trust. Since whistleblowing situations often pose problems for whistleblowers, organisational trust becomes an important facilitator for the decision to blow the whistle. Drawing on a case study, this paper shows that when trust exists, employees are more likely to blow the whistle and to do so internally rather than externally.

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.

Final report on international comparison CCQM-K83: Halocarbons in dry whole air

Science.gov (United States)

Rhoderick, George; Guenther, Franklin; Duewer, David; Lee, Jeongsoon; Moon, Dongmin; Lee, Jinbok; Lim, Jeongsik; Seog Kim, Jin

2014-01-01

The growing awareness of climate change/global warming and continuing concerns regarding stratospheric ozone depletion will require future measurements and standards for many compounds, in particular halocarbons that are linked to these issues. In order to track and control the emissions of these species globally in the atmosphere, it is necessary to demonstrate measurement equivalence at the highest levels of accuracy for assigned values of standards. This report describes the results of a key comparison for several of the more important halocarbons at atmospheric concentration levels. The comparison includes the chlorofluorocarbons (CFCs) dichlorodifluoromethane (CFC 12), trichlorofluoromethane (CFC 11), and 1,1,2 trichlorotrifluoroethane (CFC 113); the hydrochlorofluorocarbons (HCFCs) chlorodifluoromethane (HCFC 22) and 1-chloro-1,1-difluoroethane (HCFC 142b); and the hydrofluorocarbon (HFC) 1,1,1,2 tetrafluoroethane (HFC 134a), all in a dried whole air sample. The objective of this key comparison is to compare the measurement capabilities of the participants for these halocarbons at trace atmospheric levels. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

A Basic Study on Countermeasure Against Aerodynamic Force Acting on Train Running Inside Tunnel Using Air Blowing

Science.gov (United States)

Suzuki, Masahiro; Nakade, Koji

A basic study of flow controls using air blowing was conducted to reduce unsteady aerodynamic force acting on trains running in tunnels. An air blowing device is installed around a model car in a wind tunnel. Steady and periodic blowings are examined utilizing electromagnetic valves. Pressure fluctuations are measured and the aerodynamic force acting on the car is estimated. The results are as follows: a) The air blowing allows reducing the unsteady aerodynamic force. b) It is effective to blow air horizontally at the lower side of the car facing the tunnel wall. c) The reduction rate of the unsteady aerodynamic force relates to the rate of momentum of the blowing to that of the uniform flow. d) The periodic blowing with the same frequency as the unsteady aerodynamic force reduces the aerodynamic force in a manner similar to the steady blowing.

Release and attenuation of fluorocarbons in landfills

DEFF Research Database (Denmark)

Kjeldsen, Peter; Scheutz, Charlotte

2003-01-01

Several halocarbons with very high global warming and ozone depleting potentials have been used as blowing agent for insulation foam in refrigerators and freezers. Many appliances are shredded after the end of their useful life. Release experiments carried out in the laboratory on insulation foam...... blown with CFC-11, HCFC-141b, HFC- 134a, and HFC-245fa revealed that most of the blowing agent is not released to the atmosphere during a six-week period following the shredding process. The fraction which is released in the six-week period is highly dependent on how fine the foam is shredded....... The residual blowing agent remaining after the six-week period may be very slowly released if the integrity of the foam particles with respect to diffusional properties is kept after disposal of the foam waste in landfills. Laboratory experiments simulating attenuation processes in the landfilled waste...

Mathematical model of whole-process calculation for bottom-blowing copper smelting

Science.gov (United States)

Li, Ming-zhou; Zhou, Jie-min; Tong, Chang-ren; Zhang, Wen-hai; Li, He-song

2017-11-01

The distribution law of materials in smelting products is key to cost accounting and contaminant control. Regardless, the distribution law is difficult to determine quickly and accurately by mere sampling and analysis. Mathematical models for material and heat balance in bottom-blowing smelting, converting, anode furnace refining, and electrolytic refining were established based on the principles of material (element) conservation, energy conservation, and control index constraint in copper bottom-blowing smelting. Simulation of the entire process of bottom-blowing copper smelting was established using a self-developed MetCal software platform. A whole-process simulation for an enterprise in China was then conducted. Results indicated that the quantity and composition information of unknown materials, as well as heat balance information, can be quickly calculated using the model. Comparison of production data revealed that the model can basically reflect the distribution law of the materials in bottom-blowing copper smelting. This finding provides theoretical guidance for mastering the performance of the entire process.

Blow Flies Visiting Decaying Alligators: Is Succession Synchronous or Asynchronous?

OpenAIRE

Nelder, Mark P.; McCreadie, John W.; Major, Clinton S.

2009-01-01

Succession patterns of adult blow flies (Diptera: Calliphoridae) on decaying alligators were investigated in Mobile (Ala, USA) during August 2002. The most abundant blow fly species visiting the carcasses were Chrysomya rufifacies (Macquart), Cochliomyia macellaria (Fabricus), Chrysomya megacephala (Fabricus), Phormia regina (Meigen), and Lucilia coeruleiviridis (Macquart). Lucilia coeruleiviridis was collected more often during the early stages of decomposition, followed by Chrysomya spp., C...

Blowing snow sublimation and transport over Antarctica from 11 years of CALIPSO observations

Directory of Open Access Journals (Sweden)

S. P. Palm

2017-11-01

Full Text Available Blowing snow processes commonly occur over the earth's ice sheets when the 10 m wind speed exceeds a threshold value. These processes play a key role in the sublimation and redistribution of snow thereby influencing the surface mass balance. Prior field studies and modeling results have shown the importance of blowing snow sublimation and transport on the surface mass budget and hydrological cycle of high-latitude regions. For the first time, we present continent-wide estimates of blowing snow sublimation and transport over Antarctica for the period 2006–2016 based on direct observation of blowing snow events. We use an improved version of the blowing snow detection algorithm developed for previous work that uses atmospheric backscatter measurements obtained from the CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization lidar aboard the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation satellite. The blowing snow events identified by CALIPSO and meteorological fields from MERRA-2 are used to compute the blowing snow sublimation and transport rates. Our results show that maximum sublimation occurs along and slightly inland of the coastline. This is contrary to the observed maximum blowing snow frequency which occurs over the interior. The associated temperature and moisture reanalysis fields likely contribute to the spatial distribution of the maximum sublimation values. However, the spatial pattern of the sublimation rate over Antarctica is consistent with modeling studies and precipitation estimates. Overall, our results show that the 2006–2016 Antarctica average integrated blowing snow sublimation is about 393 ± 196 Gt yr−1, which is considerably larger than previous model-derived estimates. We find maximum blowing snow transport amount of 5 Mt km−1 yr−1 over parts of East Antarctica and estimate that the average snow transport from continent to ocean is about 3.7 Gt yr−1. These

SIKAP, NORMA SUBJEKTIF, DAN INTENSI PEGAWAI NEGERI SIPIL UNTUK MENGADUKAN PELANGGARAN (WHISTLE-BLOWING

Directory of Open Access Journals (Sweden)

Erwan Suryono

2016-06-01

Full Text Available This study aims to investigate factors that influence civil servants to whistle-blow fraud. It also investigates the effect of government’s bureaucracy reforming program on the civil servants’ intention to whistle-blow fraud. By employing the theory of reasoned action, this study included variables of subjective norms, attitudes, and whistle-blowing intentions. This study used primary data gathered from questionnaires of 293 respondents. Respondents were civil servants in the ministries/agencies that have and have not implemented bureaucratic reforms. The findings of this study indicated that subjective norms positively affected the attitudes and intentions of civil servants to report the wrongdoings. However, the attitudes had no significant effect on civil servants’ whistle-blowing intentions. In addition, there are no significant differences on subjective norms, attitudes, and whistle-blowing intentions between civil servants in ministries/agencies that have implemented bureaucratic reforms and civil servants in ministries/agencies that have not implement bureaucratic reforms.

Reduction of airfoil trailing edge noise by trailing edge blowing

International Nuclear Information System (INIS)

Gerhard, T; Carolus, T; Erbslöh, S

2014-01-01

The paper deals with airfoil trailing edge noise and its reduction by trailing edge blowing. A Somers S834 airfoil section which originally was designed for small wind turbines is investigated. To mimic realistic Reynolds numbers the boundary layer is tripped on pressure and suction side. The chordwise position of the blowing slot is varied. The acoustic sources, i.e. the unsteady flow quantities in the turbulent boundary layer in the vicinity of the trailing edge, are quantified for the airfoil without and with trailing edge blowing by means of a large eddy simulation and complementary measurements. Eventually the far field airfoil noise is measured by a two-microphone filtering and correlation and a 40 microphone array technique. Both, LES-prediction and measurements showed that a suitable blowing jet on the airfoil suction side is able to reduce significantly the turbulence intensity and the induced surface pressure fluctuations in the trailing edge region. As a consequence, trailing edge noise associated with a spectral hump around 500 Hz could be reduced by 3 dB. For that a jet velocity of 50% of the free field velocity was sufficient. The most favourable slot position was at 90% chord length

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.

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.

Blow-up boundary regimes for general quasilinear parabolic equations in multidimensional domains

International Nuclear Information System (INIS)

Shishkov, A E; Shchelkov, A G

1999-01-01

A new approach (not based on the techniques of barriers) to the study of asymptotic properties of the generalized solutions of parabolic initial boundary-value problems with finite-time blow-up of the boundary values is proposed. Precise conditions on the blow-up pattern are found that guarantee uniform localization of the solution for an arbitrary compactly supported initial function. The main result of the paper consists in obtaining precise sufficient conditions for the singular (or blow-up) set of an arbitrary solution to remain within the boundary of the domain

Prevalence and virulence factors of Candida spp. associated with blow flies

Directory of Open Access Journals (Sweden)

Wimonrat GunTang

2017-05-01

Conclusions: The results indicate that blow flies could play an essential role in the transmission of potentially pathogenic and antifungal resistant C. albicans into the environment. Further investigation on other virulence factors and genetic relatedness among isolates from the blow flies, the environment and clinical specimens is required to confirm this role.

Effects of cathode channel size and operating conditions on the performance of air-blowing PEMFCs

International Nuclear Information System (INIS)

Kim, Bosung; Lee, Yongtaek; Woo, Ahyoung; Kim, Yongchan

2013-01-01

Highlights: • Effect of cathode channel size on the air-blowing PEMFC is analyzed. • Performance and EIS tests of air-blowing PEMFCs are conducted. • Test conditions include the operating temperature, fan voltage, and anode humidity. • Flooding is a limiting factor for decreasing channel size at low temperature. • Water management is investigated by analyzing ohmic resistance. - Abstract: Air-blowing proton exchange membrane fuel cells (PEMFCs) have been developed as a potential new power source for portable electronic devices. However, air-blowing PEMFCs show lower performance than compressed-air PEMFCs because of their adverse operating conditions. In this study, the effects of the cathode channel size and operating conditions on the performance of the air-blowing PEMFC were analyzed. At the normal operating temperature, the performance of the air-blowing PEMFC improved with the decrease in the cathode channel size. However, at a low operating temperature and low fan voltage, massive flooding limits the decrease in the cathode channel size. In addition, water management in the air-blowing PEMFC was investigated by analyzing ohmic resistance. The transition current density between the humidification and the flooding region decreased with decreasing cathode channel size and operating temperature

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)

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.

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.

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.

Shooting method for solution of boundary-layer flows with massive blowing

Science.gov (United States)

Liu, T.-M.; Nachtsheim, P. R.

1973-01-01

A modified, bidirectional shooting method is presented for solving boundary-layer equations under conditions of massive blowing. Unlike the conventional shooting method, which is unstable when the blowing rate increases, the proposed method avoids the unstable direction and is capable of solving complex boundary-layer problems involving mass and energy balance on the surface.

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

KAUST Repository

Wang, Qiang; Hu, Longhua; Chung, Suk-Ho

2016-01-01

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.

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.

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

International Nuclear Information System (INIS)

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

2005-01-01

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

Control of leading edge vortex breakdown by blowing

Science.gov (United States)

Visser, K. D.; Iwanski, K. P.; Nelson, R. C.; Ng, T. T.

1988-01-01

An investigation into the effects of using a jet of air to control the vortex breakdown position on a 70 degree delta wing is presented. The specific objectives focused on optimizing the blowing positions in terms of maximum lift increments obtained for minimum blowing rates. The tests were conducted at chord Reynolds numbers of 150,000, 200,000, and 250,000 at angles of incidence of 30 and 35 degrees. Visualization and force data is presented to show the effect of the jet on the wing aerodynamic characteristics. The results indicate a jet position located at and aligned parallel to the leading edge to be the optimum. Nearness to the apex and tangency to the upper surface were also crucial factors. The influence of the jet on the leading edge vortex structure was examined using laser Doppler anemometry. Velocity surveys through the vortex showed that at high blowing rates the parallel velocity in the outer swirling region of the vortex increased and the normal velocity decreased. This resulted in a decrease in the swirling angle in the outer region. The peak core velocity was reduced and the vortex breakdown was delayed.

Blow-off of hydrogen using an optimized design of discharge jet-mixer arrangement

International Nuclear Information System (INIS)

Ristow, Torsten

2011-01-01

Hydrogen is ignitable in air at volume concentrations between 4 % and 75 %. Therefore, in the case of an emergency evacuation of a hydrogen-cooled generator in nuclear power plants, the gas has to be safely blown-off above the turbine building. Especially, a leakage at the hydrogen containing piping system at the generator has gained more and more importance in the context of safety assessments. The design of a blow-off system respects two safety aspects: Firstly, a short blow-off time is necessary to reduce the hydrogen release inside the turbine building in case of a leakage. Secondly, for the postulated ignition of the released hydrogen on the roof of the building the resulting pressure load must remain below the maximum admissible one of the turbine building roof. In order to fulfill the first condition an appropriate fast evacuation piping system from the generator to the blow-off outlet is designed. Regarding the latter the blow-off system uses special discharge nozzles placed horizontally in a radial-symmetric configuration. In this respect, the influence of strong wind conditions during the evacuation process is also considered. The resulting ignitable volume of the overlapping H2-air clouds does not exceed the maximum allowed ignitable volume. In the following the underlying process of blow-off by a fast hydrogen evacuation system is discussed. First the transient general blow-off behavior in the dedicated piping system is analyzed with the fluid piping tool ROLAST. The results of these calculations are boundary conditions for the subsequent qualification of the blow-off jet-mixer. Here a proof of the general functionality is given (2D CFD). Subsequently the blow-off behavior of the H2-air mixture is discussed in independent 3D CFD calculations with and without wind. From these analyses the possible ignitable gas volumes are determined. Final step is a simplified semi-analytical assessment of the resulting possible deflagration loads on the civil structure

Blowing-up Semilinear Wave Equation with Exponential ...

Indian Academy of Sciences (India)

Blowing-up Semilinear Wave Equation with Exponential Nonlinearity in Two Space ... We investigate the initial value problem for some semi-linear wave equation in two space dimensions with exponential nonlinearity growth. ... Current Issue

Blow molding electric drives of Mechanical Engineering

Science.gov (United States)

Bukhanov, S. S.; Ramazanov, M. A.; Tsirkunenko, A. T.

2018-03-01

The article considers the questions about the analysis of new possibilities, which gives the use of adjustable electric drives for blowing mechanisms of plastic production. Thus, the use of new semiconductor converters makes it possible not only to compensate the instability of the supply network by using special dynamic voltage regulators, but to improve (correct) the power factor. The calculation of economic efficiency in controlled electric drives of blowing mechanisms is given. On the basis of statistical analysis, the calculation of the reliability parameters of the regulated electric drives’ elements under consideration is given. It is shown that an increase in the reliability of adjustable electric drives is possible both due to overestimation of the electric drive’s installed power, and in simpler schemes with pulse-vector control.

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.

Navier-Stokes Computations of a Wing-Flap Model With Blowing Normal to the Flap Surface

Science.gov (United States)

Boyd, D. Douglas, Jr.

2005-01-01

A computational study of a generic wing with a half span flap shows the mean flow effects of several blown flap configurations. The effort compares and contrasts the thin-layer, Reynolds averaged, Navier-Stokes solutions of a baseline wing-flap configuration with configurations that have blowing normal to the flap surface through small slits near the flap side edge. Vorticity contours reveal a dual vortex structure at the flap side edge for all cases. The dual vortex merges into a single vortex at approximately the mid-flap chord location. Upper surface blowing reduces the strength of the merged vortex and moves the vortex away from the upper edge. Lower surface blowing thickens the lower shear layer and weakens the merged vortex, but not as much as upper surface blowing. Side surface blowing forces the lower surface vortex farther outboard of the flap edge by effectively increasing the aerodynamic span of the flap. It is seen that there is no global aerodynamic penalty or benefit from the particular blowing configurations examined.

Asymptotic properties of blow-up solutions in reaction-diffusion equations with nonlocal boundary flux

Science.gov (United States)

Liu, Bingchen; Dong, Mengzhen; Li, Fengjie

2018-04-01

This paper deals with a reaction-diffusion problem with coupled nonlinear inner sources and nonlocal boundary flux. Firstly, we propose the critical exponents on nonsimultaneous blow-up under some conditions on the initial data. Secondly, we combine the scaling technique and the Green's identity method to determine four kinds of simultaneous blow-up rates. Thirdly, the lower and the upper bounds of blow-up time are derived by using Sobolev-type differential inequalities.

Influence of Polylactide Modification with Blowing Agents on Selected Mechanical Properties

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Aneta Tor-Świątek

2017-12-01

Full Text Available Article presents research of modification of PLA with four types of chemical blowing agents with a different decomposition characteristic. The modification was done both cellular extrusion and injection molding processes. Obtained results shows that dosing blowing agents have the influence on mechanical properties and structure morphology of PLA. The differences in obtained results are also visible and significant between cellular processes.

Blow-up, Global Existence and Persistence Properties for the Coupled Camassa–Holm equations

International Nuclear Information System (INIS)

Zhu Mingxuan

2011-01-01

In this paper, we consider the coupled Camassa–Holm equations. First, we present some new criteria on blow-up. Then global existence and blow-up rate of the solution are also established. Finally, we discuss persistence properties of this system.

The index of a vector field under blow ups

International Nuclear Information System (INIS)

Seade, J.

1991-08-01

A useful technique when studying the behaviour of holomorphic vector fields around their isolated singularities is that of blowing up the singular points. On the other hand, the most basic invariant of a vector field with isolated singularities is its local index, as defined by Poincare and Hopf. It is thus natural to ask how does the index of a vector field behaves under blowing ups? The purpose of this work is to study and answer this question, by taking a rather general point of view and bearing in mind that complex manifolds have a powerful birational invariant, the Todd genus. 20 refs

Transition between extinction and blow-up in a generalized Fisher–KPP model

Energy Technology Data Exchange (ETDEWEB)

Hernández-Bermejo, Benito, E-mail: benito.hernandez@urjc.es [Departamento de Física, Universidad Rey Juan Carlos, Calle Tulipán S/N, 28933, Móstoles, Madrid (Spain); Sánchez-Valdés, Ariel [Departamento de Matemática Aplicada, Universidad Rey Juan Carlos, Calle Tulipán S/N, 28933, Móstoles, Madrid (Spain)

2014-05-01

Stationary solutions of the Fisher–KPP equation with general nonlinear diffusion and arbitrary reactional kinetic orders terms are characterized. Such stationary (separatrix-like) solutions disjoint the blow-up solutions from those showing extinction. In addition a criterion for general parameter values is presented, which allows determining the blow-up or vanishing character of the solutions.

Transition between extinction and blow-up in a generalized Fisher–KPP model

International Nuclear Information System (INIS)

Hernández-Bermejo, Benito; Sánchez-Valdés, Ariel

2014-01-01

Stationary solutions of the Fisher–KPP equation with general nonlinear diffusion and arbitrary reactional kinetic orders terms are characterized. Such stationary (separatrix-like) solutions disjoint the blow-up solutions from those showing extinction. In addition a criterion for general parameter values is presented, which allows determining the blow-up or vanishing character of the solutions.

Finite-time blow-up for quasilinear degenerate Keller-Segel systems of parabolic-parabolic type

Science.gov (United States)

Hashira, Takahiro; Ishida, Sachiko; Yokota, Tomomi

2018-05-01

This paper deals with the quasilinear degenerate Keller-Segel systems of parabolic-parabolic type in a ball of RN (N ≥ 2). In the case of non-degenerate diffusion, Cieślak-Stinner [3,4] proved that if q > m + 2/N, where m denotes the intensity of diffusion and q denotes the nonlinearity, then there exist initial data such that the corresponding solution blows up in finite time. As to the case of degenerate diffusion, it is known that a solution blows up if q > m + 2/N (see Ishida-Yokota [13]); however, whether the blow-up time is finite or infinite has been unknown. This paper gives an answer to the unsolved problem. Indeed, the finite-time blow-up of energy solutions is established when q > m + 2/N.

Effects of free-stream turbulence intensity and blowing ratio on film cooling of turbine blade leading edge

International Nuclear Information System (INIS)

Kim, S. M.; Kim, Youn J.; Cho, H. H.

2001-01-01

We used a cylindrical model which simulates turbine blade leading edge to investigate the effects of free-stream turbulence intensity and blowing ratio on film cooling of turbine blade leading edge. Tests are carried out in a low-speed wind tunnel on a cylindrical model with three rows of injection holes. Mainstream Reynolds number based on the cylinder diameter was 7.1x10 4 . Two types of turbulence grid are used to increase a free-stream turbulence intensity. The effect of coolant blowing ratio was studied for various blowing ratios. For each blowing ratios, wall temperatures around the surface of the test model are measured by thermocouples installed inside the model. Results show that blowing ratios have small effect on spanwise-averaged film effectiveness at high free-stream turbulence intensity. However, an increase in free-stream turbulence intensity enhances significantly spanwise-averaged film effectiveness at low blowing ratio

The performance of ethics course for increasing students intention to blow the whistle using information technology

Science.gov (United States)

Munandar, Agus

2017-10-01

The profession of accounting believes that ethics is very important in the workplace. For that, profession recommends that ethics course should be taught for accounting student. Unfornutaly, the impact of ethics courses on accounting students intention to blow the whistle on organizational wrongdoing using information technology have not been determined. For that, this paper attempts to measure the impact of ethics courses on accounting student intention to blow the whistle on organizational wrongdoing. The research using experimental design for investigate the impact of ethic course on students intention to blow the whistle using IT. The respondents for this study are 40 accountig students. The respondent were given the ethical scenarios and were measured their intention to blow the whistle using information technology. This result of study reports that 70% of accounting student who completed ethic course indicated high intention to blow the whistle on organizational wrongdoing using information technology. Hence, ethics course is beneficial for increasing accounting professionalism especially their intentio to blow the whistle wrongdoing using information technology.

A Mathematical Model for Reactions During Top-Blowing in the AOD Process: Validation and Results

Science.gov (United States)

Visuri, Ville-Valtteri; Järvinen, Mika; Kärnä, Aki; Sulasalmi, Petri; Heikkinen, Eetu-Pekka; Kupari, Pentti; Fabritius, Timo

2017-06-01

In earlier work, a fundamental mathematical model was proposed for side-blowing operation in the argon oxygen decarburization (AOD) process. In the preceding part "Derivation of the Model," a new mathematical model was proposed for reactions during top-blowing in the AOD process. In this model it was assumed that reactions occur simultaneously at the surface of the cavity caused by the gas jet and at the surface of the metal droplets ejected from the metal bath. This paper presents validation and preliminary results with twelve industrial heats. In the studied heats, the last combined-blowing stage was altered so that oxygen was introduced from the top lance only. Four heats were conducted using an oxygen-nitrogen mixture (1:1), while eight heats were conducted with pure oxygen. Simultaneously, nitrogen or argon gas was blown via tuyères in order to provide mixing that is comparable to regular practice. The measured carbon content varied from 0.4 to 0.5 wt pct before the studied stage to 0.1 to 0.2 wt pct after the studied stage. The results suggest that the model is capable of predicting changes in metal bath composition and temperature with a reasonably high degree of accuracy. The calculations indicate that the top slag may supply oxygen for decarburization during top-blowing. Furthermore, it is postulated that the metal droplets generated by the shear stress of top-blowing create a large mass exchange area, which plays an important role in enabling the high decarburization rates observed during top-blowing in the AOD process. The overall rate of decarburization attributable to top-blowing in the last combined-blowing stage was found to be limited by the mass transfer of dissolved carbon.

Comparison of halocarbon measurements in an atmospheric dry whole air sample.

Science.gov (United States)

Rhoderick, George C; Hall, Bradley D; Harth, Christina M; Kim, Jin Seog; Lee, Jeongsoon; Montzka, Stephen A; Mühle, Jens; Reimann, Stefan; Vollmer, Martin K; Weiss, Ray F

The growing awareness of climate change/global warming, and continuing concerns regarding stratospheric ozone depletion, will require continued measurements and standards for many compounds, in particular halocarbons that are linked to these issues. In order to track atmospheric mole fractions and assess the impact of policy on emission rates, it is necessary to demonstrate measurement equivalence at the highest levels of accuracy for assigned values of standards. Precise measurements of these species aid in determining small changes in their atmospheric abundance. A common source of standards/scales and/or well-documented agreement of different scales used to calibrate the measurement instrumentation are key to understanding many sets of data reported by researchers. This report describes the results of a comparison study among National Metrology Institutes and atmospheric research laboratories for the chlorofluorocarbons (CFCs) dichlorodifluoromethane (CFC-12), trichlorofluoromethane (CFC-11), and 1,1,2-trichlorotrifluoroethane (CFC-113); the hydrochlorofluorocarbons (HCFCs) chlorodifluoromethane (HCFC-22) and 1-chloro-1,1-difluoroethane (HCFC-142b); and the hydrofluorocarbon (HFC) 1,1,1,2-tetrafluoroethane (HFC-134a), all in a dried whole air sample. The objective of this study is to compare calibration standards/scales and the measurement capabilities of the participants for these halocarbons at trace atmospheric levels. The results of this study show agreement among four independent calibration scales to better than 2.5% in almost all cases, with many of the reported agreements being better than 1.0%.

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%.

Comparison of halocarbon measurements in an atmospheric dry whole air sample

Science.gov (United States)

Hall, Bradley D.; Harth, Christina M.; Kim, Jin Seog; Lee, Jeongsoon; Montzka, Stephen A.; Mühle, Jens; Reimann, Stefan; Vollmer, Martin K.; Weiss, Ray F.

2015-01-01

The growing awareness of climate change/global warming, and continuing concerns regarding stratospheric ozone depletion, will require continued measurements and standards for many compounds, in particular halocarbons that are linked to these issues. In order to track atmospheric mole fractions and assess the impact of policy on emission rates, it is necessary to demonstrate measurement equivalence at the highest levels of accuracy for assigned values of standards. Precise measurements of these species aid in determining small changes in their atmospheric abundance. A common source of standards/scales and/or well-documented agreement of different scales used to calibrate the measurement instrumentation are key to understanding many sets of data reported by researchers. This report describes the results of a comparison study among National Metrology Institutes and atmospheric research laboratories for the chlorofluorocarbons (CFCs) dichlorodifluoromethane (CFC-12), trichlorofluoromethane (CFC-11), and 1,1,2-trichlorotrifluoroethane (CFC-113); the hydrochlorofluorocarbons (HCFCs) chlorodifluoromethane (HCFC-22) and 1-chloro-1,1-difluoroethane (HCFC-142b); and the hydrofluorocarbon (HFC) 1,1,1,2-tetrafluoroethane (HFC-134a), all in a dried whole air sample. The objective of this study is to compare calibration standards/scales and the measurement capabilities of the participants for these halocarbons at trace atmospheric levels. The results of this study show agreement among four independent calibration scales to better than 2.5% in almost all cases, with many of the reported agreements being better than 1.0%. PMID:26753167

Analysis of Tonguing and Blowing Actions During Clarinet Performance.

Science.gov (United States)

Pàmies-Vilà, Montserrat; Hofmann, Alex; Chatziioannou, Vasileios

2018-01-01

Articulation on the clarinet is achieved by a combination of precise actions taking place inside the player's mouth. With the aim to analyse the effects of tonguing and blowing actions during playing, several physical variables are measured and parameters related to articulation are studied. Mouth pressure, mouthpiece pressure and reed displacement are recorded in an experiment with clarinet players to evaluate the influence of the player's actions on the selected parameters and on the sound. The results show that different combinations of tongue and blowing actions are used during performance. Portato and legato playing show constant blowing throughout the musical phrase, which varies according to the dynamic level. In portato, short tongue-reed interaction is used homogeneously among players and playing conditions. In staccato playing, where the tongue-reed contact is longer, the mouth pressure is reduced significantly between notes. Such a mouth-pressure decrease might be used to stop the note in slow staccato playing. It is hereby shown that when the note is stopped by the action of the tongue both the attack and release transients are shorter compared to the case where the vibration of the reed is stopped by a decrease of mouth pressure.

INCOMPRESSIBLE LAMINAR BOUNDARY LAYER CONTROL BY BLOWING AND SUCTION

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AZZEDINE NAHOUI

2013-12-01

Full Text Available A two-dimensional incompressible laminar boundary layer and its control using blowing and suction over a flat plate and around the NACA 0012 and 661012 profiles, is studied numerically. The study is based on the Prandtl boundary layer model using the finite differences method and the Crank-Nicolson scheme. The velocity distribution, the boundary layer thickness and the friction coefficient, are determined and presented with and without control. The application of the control technique, has demonstrated its positive effect on the transition point and the friction coefficient. Both control procedures are compared for different lengths, speeds and angles of blowing and suction.

Sex determination mechanisms in the Calliphoridae (blow flies).

Science.gov (United States)

Scott, M J; Pimsler, M L; Tarone, A M

2014-01-01

The Calliphoridae or blow flies are a family of insects that occupy diverse habitats and perform important ecological roles, particularly the decomposition of animal remains. Some Calliphoridae species are also important in the forensic sciences, in agriculture (e.g. as livestock pests) and in medicine (e.g. maggot therapy). Calliphoridae provide striking examples in support of the hypothesis that sex determination regulatory gene hierarchies evolve in the reverse order, with the gene at the top being the most recently added. Unlike the model fly Drosophila melanogaster, where sex is determined by the number of X chromosomes, in the Australian sheep blow fly (Lucilia cuprina) sex is determined by a Y-linked male-determining gene (M). A different regulatory system appears to operate in the hairy maggot blow fly (Chrysomya rufifacies) where the maternal genotype determines sex. It is hypothesized that females heterozygous for a dominant female-determining factor (F/f) produce only female offspring and homozygous f/f females produce only sons. The bottom of the regulatory hierarchy appears to be the same in D. melanogaster and L. cuprina, with sex-specific splicing of doublesex transcripts being controlled by the female-specific Transformer (TRA) protein. We discuss a model that has been proposed for how tra transcripts are sex-specifically spliced in calliphorids, which is very different from D. melanogaster. © 2013 S. Karger AG, Basel.

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

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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.

Blow fly maggots (Diptera: Calliphoridae)from a human corpse in a vehicle.

Science.gov (United States)

Sribanditmongkol, Pongruk; Monum, Tawachai; Wannasan, Anchalee; Tomberlin, Jeffery K; Sukontason, Kom; Sukontason, Kabkaew L

2014-09-01

Correct species identification and development data of insects associated with a cadaver can help estimate the time of colonization which could be used to infer a minimal post-mortem interval (minPMI) for forensic investigations. Human remains are found in a variety of locations ranging from open fields to inside automobiles. We report the investigation of blow fly larvae collected from a decomposing body located in the trunk of a car. There were two blow fly (Diptera: Calliphoridae) species: Achoetandrus rufifacies (Macquart) and Chrysomya megacephala (Fabricius). Blow flies can enter the vehicle and colonize human remains. Based on age estimations of third stage larvae of A. rufifacies, the minPMI was estimated to be 4-5 days, which was within the range of 3-5 days estimated by other forensically relevant information.

Analysis of Tonguing and Blowing Actions During Clarinet Performance

Directory of Open Access Journals (Sweden)

Montserrat Pàmies-Vilà

2018-04-01

Full Text Available Articulation on the clarinet is achieved by a combination of precise actions taking place inside the player's mouth. With the aim to analyse the effects of tonguing and blowing actions during playing, several physical variables are measured and parameters related to articulation are studied. Mouth pressure, mouthpiece pressure and reed displacement are recorded in an experiment with clarinet players to evaluate the influence of the player's actions on the selected parameters and on the sound. The results show that different combinations of tongue and blowing actions are used during performance. Portato and legato playing show constant blowing throughout the musical phrase, which varies according to the dynamic level. In portato, short tongue-reed interaction is used homogeneously among players and playing conditions. In staccato playing, where the tongue-reed contact is longer, the mouth pressure is reduced significantly between notes. Such a mouth-pressure decrease might be used to stop the note in slow staccato playing. It is hereby shown that when the note is stopped by the action of the tongue both the attack and release transients are shorter compared to the case where the vibration of the reed is stopped by a decrease of mouth pressure.

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

Science.gov (United States)

Naqqash, Muhammad Nadir; 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 flies for pollination, and trees were covered with a net but without insects. Results: The maximum number of flowers was recorded in irregular types of inflorescence, i.e., 434.80 flowers/inflorescence. Fruit setting (bud) was higher in open pollinated mango trees (i.e. 37.00/inflorescence) than enclosed pollination by blow flies (i.e. 22.34/inflorescence). The size of the mango fruit was the highest (5.06 mm) in open pollinated tree than those pollinated by blow flies (3.93 mm) and followed by without any pollinator (3.18 mm) at marble stage. We found that the maximum weight of mango fruit (201.19 g) was in open pollinated trees. Discussion: The results demonstrated that blow flies can be used as effective mango pollinators along with other flies and bees. The blow flies have shown a positive impact on the quality and quantity of mango. This study will be helpful in future and also applicable at farm level to use blow flies as pollinators that are cheap and easy to rear. PMID:27441107

Cycle Time Optimization of Chamomile Package 120 MI Product at Blow Molding Process

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Yuni Hermawan

2012-11-01

Full Text Available Chamomile is a package which is applied for cosmetic. In industry this package is being processed by blow molding. Thereare many parameters that influence cycle time during production; in this project only three of them were varied, i.e. blowingpressure, blowing time and stopping time. Each parameter is determined three chosen level. Middle level is taken fromstandard setting of machining which is being used by industry. Top and bottom level is randomized. Three stopping time are0.1, 0.55, and 1.0 second. Blowing time are 10.5, 11.5 and 12.5 second. Where as, blowing pressures is 4, 5 and 6 bar.Combination of among levels is based on Box Behnken design. Those three parameters are called variable process. In theother hand, variable responses are cycle time and net weight. Each combination is replicated 5 times and then averaged. Thedata then is processed by using Minitab version 14th. Square regression of the model for cycle time is ?CT = 21,1300 - 0,0912X1 + 0,2000 X2 + 0,6313 X3 + 0,6100 X12 + 0,6975 X22 – 0,1000 X1 X2 – 0,1725 X1 X3 + 0,1100 X2 X3 and Net = 19,2933 –0,0088 X1 + 0,0175 X2 + 0,0712 X3 + 0,0133 X 21 + 0.0158 X22- 0.0217 X 23 + 0.0125 X1X2 - 0,0150 X1 X3 for product netweight. Where X1 is blowing pressure, X2 is blowing time and X3 is stopping time.The model developed then tested by lack offit testing, variance by ANOVA and R square. Second stage of model testing is residual test. Three tests are carry out, i.e.identically test and independency test and normality. Optimization of both values, cycle time and net weight, are searched byResponse Surface Method. By the method it is found that the optimum condition of cycle time is 20.5 seconds and net weightis 19.19 grams. The optimum condition is achieved when stopping is 0.1 second, blowing time 11.35 second and blowingpressure 5.1 bars.

Fledging success is a poor indicator of the effects of bird blow flies on ovenbird survival

Science.gov (United States)

Peterson, Sean M.; Streby, Henry M.; Kapfer, Paul M.

2009-01-01

Infestations of bird blow flies (Protocalliphora spp. and Trypocalliphora braueri) have various negative effects on the condition of nestling birds. In the absence of other stressors such as inclement weather, however, infestation alone rarely reduces fledging success. Previous studies have documented effects of blow flies on nestling condition and fledging success. Without information regarding fledgling survival, the full effect of blow-fly infestation remains unclear. To fully investigate the effect of blow-fly infestation on reproductive success of the Ovenbird (Seiurus aurocapilla), we monitored infested and non-infested nests and monitored fledglings from each by using radio telemetry. Blow flies did not affect birds during the nestling period, as brood size, mean nestling mass, fledging success, and time to fledging in infested and non-infested nests were no different. Fledgling survival and minimum distance traveled the first day after fledging, however, were significantly lower for infected fledglings than for those that were not infected. We conclude that the stress of the early fledgling period combined with recent or concurrent blow-fly infection increases mortality in young Oven-birds. Our results demonstrate the importance of including the post-fledging period in investigations of the effects of ectoparasitic infestations on birds.

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.

Local-in-space blow-up criteria for a class of nonlinear dispersive wave equations

Science.gov (United States)

Novruzov, Emil

2017-11-01

This paper is concerned with blow-up phenomena for the nonlinear dispersive wave equation on the real line, ut -uxxt +[ f (u) ] x -[ f (u) ] xxx +[ g (u) + f″/(u) 2 ux2 ] x = 0 that includes the Camassa-Holm equation as well as the hyperelastic-rod wave equation (f (u) = ku2 / 2 and g (u) = (3 - k) u2 / 2) as special cases. We establish some a local-in-space blow-up criterion (i.e., a criterion involving only the properties of the data u0 in a neighborhood of a single point) simplifying and precising earlier blow-up criteria for this equation.

Modeling of Mixing Behavior in a Combined Blowing Steelmaking Converter with a Filter-Based Euler-Lagrange Model

Science.gov (United States)

Li, Mingming; Li, Lin; Li, Qiang; Zou, Zongshu

2018-05-01

A filter-based Euler-Lagrange multiphase flow model is used to study the mixing behavior in a combined blowing steelmaking converter. The Euler-based volume of fluid approach is employed to simulate the top blowing, while the Lagrange-based discrete phase model that embeds the local volume change of rising bubbles for the bottom blowing. A filter-based turbulence method based on the local meshing resolution is proposed aiming to improve the modeling of turbulent eddy viscosities. The model validity is verified through comparison with physical experiments in terms of mixing curves and mixing times. The effects of the bottom gas flow rate on bath flow and mixing behavior are investigated and the inherent reasons for the mixing result are clarified in terms of the characteristics of bottom-blowing plumes, the interaction between plumes and top-blowing jets, and the change of bath flow structure.

BLOW.MOD2: program for a vessel depressurization calculation with the contribution of structures

International Nuclear Information System (INIS)

Doval, A.

1990-01-01

The BLOW.MOD2 program developed to calculate pressure vessels' depressurization is presented, considering heat contribution of the structures. The results are opposite to those obtained from other more complex numerical models, being the comparison extremely satisfactory. BLOW.MOD2 is a software of the 'Systems Sub-Branch', INVAP S.E. (Author) [es

Blow-up criteria for the 3D cubic nonlinear Schrödinger equation

International Nuclear Information System (INIS)

Holmer, Justin; Platte, Rodrigo; Roudenko, Svetlana

2010-01-01

We consider solutions u to the 3D nonlinear Schrödinger equation i∂ t u + Δu + |u| 2 u = 0. In particular, we are interested in finding criteria on the initial data u 0 that predict the asymptotic behaviour of u(t), e.g., whether u(t) blows up in finite time, exists globally in time but behaves like a linear solution for large times (scatters), or exists globally in time but does not scatter. This question has been resolved (at least for H 1 data) (Duyckaerts–Holmer–Roudenko) if M[u]E[u] ≤ M[Q]E[Q], where M[u] and E[u] denote the mass and energy of u and Q denotes the ground state solution to −Q + ΔQ + |Q| 2 Q = 0. Here we consider the complementary case M[u]E[u] > M[Q]E[Q]. In the first (analytical) part of the paper, we present a result due to Lushnikov, based on the virial identity and the generalized uncertainty principle, giving a sufficient condition for blow-up. By replacing the uncertainty principle in his argument with an interpolation-type inequality, we obtain a new blow-up condition that in some cases improves upon Lushnikov's condition. Our approach also allows for an adaptation to radial infinite-variance initial data that has a conceptual interpretation: for real-valued initial data, if a certain fraction of the mass is contained within the ball of radius M[u], then blow up occurs. We also show analytically (if one takes the numerically computed value of ||Q|| .H 1/2 ) that there exist Gaussian initial data u 0 with negative quadratic phase such that ||u 0 || .H 1/2 .H 1/2 but the solution u(t) blows up. In the second (numerical) part of the paper, we examine several different classes of initial data—Gaussian, super Gaussian, off-centred Gaussian, and oscillatory Gaussian—and for each class give the theoretical predictions for scattering or blow-up provided by the above theorems as well as the results of numerical simulation. We find that depending upon the form of the initial conditions, any of the three analytical criteria for blow

Proteus mirabilis interkingdom swarming signals attract blow flies

Science.gov (United States)

Flies transport specific bacteria with their larvae which provides a wider range of nutrients for those bacteria. Our hypothesis was that this symbiotic interaction may depend on interkingdom signaling. We obtained Proteus mirabilis from the salivary glands of the blow fly Lucilia sericat. This s...

Resection and primary anastomosis with or without modified blow-hole colostomy for sigmoid volvulus

Science.gov (United States)

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

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. PMID:18810779

Humidification of Blow-By Oxygen During Recovery of Postoperative Pediatric Patients: One Unit's Journey.

Science.gov (United States)

Donahue, Suzanne; DiBlasi, Robert M; Thomas, Karen

2018-02-02

To examine the practice of nebulizer cool mist blow-by oxygen administered to spontaneously breathing postanesthesia care unit (PACU) pediatric patients during Phase one recovery. Existing evidence was evaluated. Informal benchmarking documented practices in peer organizations. An in vitro study was then conducted to simulate clinical practice and determine depth and amount of airway humidity delivery with blow-by oxygen. Informal benchmarking information was obtained by telephone interview. Using a three-dimensional printed simulation model of the head connected to a breathing lung simulator, depth and amount of moisture delivery in the respiratory tree were measured. Evidence specific to PACU administration of cool mist blow-by oxygen was limited. Informal benchmarking revealed that routine cool mist oxygenated blow-by administration was not widely practiced. The laboratory experiment revealed minimal moisture reaching the mid-tracheal area of the simulated airway model. Routine use of oxygenated cool mist in spontaneously breathing pediatric PACU patients is not supported. Copyright © 2017 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.

Clinical investigation of CT-guided ozone-blowing and fumigation ...

African Journals Online (AJOL)

Clinical investigation of CT-guided ozone-blowing and fumigation therapy for the chronic ... African Journal of Biotechnology ... In control group, seven patients were completely cured in 45 days after being treated by traditional surgery.

Calculated trends and the atmospheric abundance of 1,1,1,2-tetrafluoroethane, 1,1-dichloro-1-fluoroethane, and 1-chloro-1,1-difluoroethane using automated in-situ gas chromatography-mass spectrometry measurements recorded at Mace Head, Ireland, from October 1994 to March 1997

Science.gov (United States)

Simmonds, P. G.; O'Doherty, S.; Huang, J.; Prinn, R.; Derwent, R. G.; Ryall, D.; Nickless, G.; Cunnold, D.

1998-01-01

The first in-situ measurements by automated gas chromatograph-mass spectrometer are reported for 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1-dichloro-1-fluoroethane, (HCFC-141b), and 1-chloro-1,1-difluoroethane, (HCFC-142b). These compounds are steadily replacing the chlorofluorocarbons (CFCs) as refrigerants, foam-blowing agents, and solvents. The concentrations of all three compounds are shown to be rapidly increasing in the atmosphere, with 134a increasing at a rate of 2.05±0.02 ppt yr-1 over the 30 months of observations. Similarly, 141b and 142b increased at rates of 2.49±0.03 and 1.24±0.02 ppt yr-1, respectively, over the same period. The concentrations recorded at the atmospheric research station at Mace Head, Ireland, on January 1, 1996, the midpoint of the time series, were 3.67 ppt (134a), 7.38 ppt (141b), and 8.78 ppt (142b). From these observations we optimally estimate the HCFC and HFC emissions using a 12-box global model and OH concentrations derived from global 1,1,1-trichloroethane (CCl3CH3) measurements. Comparing two methods of estimating emissions with independent industry estimates shows satisfactory agreement for 134a and 141b, while for 142b, industry estimates are less than half those required to explain our observations.

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

Institute of Scientific and Technical Information of China (English)

无

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.

Extensive Core Microbiome in Drone-Captured Whale Blow Supports a Framework for Health Monitoring.

Science.gov (United States)

Apprill, Amy; Miller, Carolyn A; Moore, Michael J; Durban, John W; Fearnbach, Holly; Barrett-Lennard, Lance G

2017-01-01

The pulmonary system is a common site for bacterial infections in cetaceans, but very little is known about their respiratory microbiome. We used a small, unmanned hexacopter to collect exhaled breath condensate (blow) from two geographically distinct populations of apparently healthy humpback whales ( Megaptera novaeangliae ), sampled in the Massachusetts coastal waters off Cape Cod ( n = 17) and coastal waters around Vancouver Island ( n = 9). Bacterial and archaeal small-subunit rRNA genes were amplified and sequenced from blow samples, including many of sparse volume, as well as seawater and other controls, to characterize the associated microbial community. The blow microbiomes were distinct from the seawater microbiomes and included 25 phylogenetically diverse bacteria common to all sampled whales. This core assemblage comprised on average 36% of the microbiome, making it one of the more consistent animal microbiomes studied to date. The closest phylogenetic relatives of 20 of these core microbes were previously detected in marine mammals, suggesting that this core microbiome assemblage is specialized for marine mammals and may indicate a healthy, noninfected pulmonary system. Pathogen screening was conducted on the microbiomes at the genus level, which showed that all blow and few seawater microbiomes contained relatives of bacterial pathogens; no known cetacean respiratory pathogens were detected in the blow. Overall, the discovery of a shared large core microbiome in humpback whales is an important advancement for health and disease monitoring of this species and of other large whales. IMPORTANCE The conservation and management of large whales rely in part upon health monitoring of individuals and populations, and methods generally necessitate invasive sampling. Here, we used a small, unmanned hexacopter drone to noninvasively fly above humpback whales from two populations, capture their exhaled breath (blow), and examine the associated microbiome. In the

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

OpenAIRE

Cortazar, C.; Elgueta, M.; Rossi, J. D.

2006-01-01

Let $\\Omega$ be a bounded smooth domain in $\\RR^N$. We consider the problem $u_t= \\Delta u + V(x) u^p$ in $\\Omega \\times [0,T)$, with Dirichlet boundary conditions $u=0$ on $\\partial \\Omega \\times [0,T)$ and initial datum $u(x,0)= M \\phi (x)$ where $M \\geq 0$, $\\phi$ 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 ne...

LES-based characterization of a suction and oscillatory blowing fluidic actuator

Science.gov (United States)

Kim, Jeonglae; Moin, Parviz

2015-11-01

Recently, a novel fluidic actuator using steady suction and oscillatory blowing was developed for control of turbulent flows. The suction and oscillatory blowing (SaOB) actuator combines steady suction and pulsed oscillatory blowing into a single device. The actuation is based upon a self-sustained mechanism of confined jets and does not require any moving parts. The control output is determined by a pressure source and the geometric details, and no additional input is needed. While its basic mechanisms have been investigated to some extent, detailed characteristics of internal turbulent flows are not well understood. In this study, internal flows of the SaOB actuator are simulated using large-eddy simulation (LES). Flow characteristics within the actuator are described in detail for a better understanding of the physical mechanisms and improving the actuator design. LES predicts the self-sustained oscillations of the turbulent jet. Switching frequency, maximum velocity at the actuator outlets, and wall pressure distribution are in good agreement with the experimental measurements. The computational results are used to develop simplified boundary conditions for numerical experiments of active flow control. Supported by the Boeing company.

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...... of the blowing agent is not released to the atmosphere during a six-week period following the shredding process. The fraction which is released in the six-week period, is highly dependent on how fine the foam is shredded. The residual blowing agent remaining after the six-week period may be very slowly released...

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.

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.

Droplet-born air blowing: novel dissolving microneedle fabrication.

Science.gov (United States)

Kim, Jung Dong; Kim, Miroo; Yang, Huisuk; Lee, Kwang; Jung, Hyungil

2013-09-28

The microneedle-mediated drug delivery system has been developed to provide painless self-administration of drugs in a patient-friendly manner. Current dissolving microneedle fabrication methods, however, require harsh conditions for biological drugs and also have problems standardizing the drug dose. Here, we suggested the droplet-born air blowing (DAB) method, which provides gentle (4-25 °C) and fast (≤10min) microneedle fabrication conditions without drug loss. The amount of drug in the microneedle can be controlled by the pressure and time of droplet dispenser and the air blowing shapes this droplet to the microneedle, providing a force sufficient to penetrate skin. Also, the introduction of a base structure of two layered DAB-microneedle could provide complete drug delivery without wasting of drug. The DAB-based insulin loaded microneedle shows similar bioavailability (96.6±2.4%) and down regulation of glucose level compared with subcutaneous injection. We anticipate that DAB described herein will be suitable to design dissolving microneedles for use in biological drug delivery to patients. Copyright © 2013 Elsevier B.V. All rights reserved.

The pattern of fraudulent accounting : Ethics, external auditing and internal whistle-blowing process

Directory of Open Access Journals (Sweden)

Loredana Ferri Di Fabrizio

2017-03-01

Full Text Available The ongoing debate in the literature centres on the compromised auditor’s independence in consequence of the relevant provisions perceived for non-audit services provided to the audited clients. The accounting scandals that have occurred over the past two decades show the lack of competence and independence of external auditors, who kept quite in the face of attempted frauds. The case of Tesco represents an undeniable example of the loss of auditor’s independence, who failed to detect accounting manipulation confirming the importance of whistle-blowing procedures in disclosing concerns before they become serious problems. When turnover occurs in CEOs it is more likely that a rotation in external auditors occurs as well. Finally, changes in top management enable whistle-blowing actions to be successful, interrupting the organization’s dependence on serious wrongdoings and preventing a disastrous ending. The success of whistle-blowing in preventing company failure makes it an effective instrument of сorporate пovernance.

Assessing the stretch-blow moulding FE simulation of PET over a large process window

Science.gov (United States)

Nixon, J.; Menary, G. H.; Yan, S.

2017-10-01

Injection stretch blow moulding has been extensively researched for numerous years and is a well-established method of forming thin-walled containers. This paper is concerned with validating the finite element analysis of the stretch-blow-moulding (SBM) process in an effort to progress the development of injection stretch blow moulding of poly(ethylene terephthalate). Extensive data was obtained experimentally over a wide process window accounting for material temperature, air flow rate and stretch-rod speed while capturing cavity pressure, stretch-rod reaction force, in-mould contact timing and material thickness distribution. This data was then used to assess the accuracy of the correlating FE simulation constructed using ABAQUS/Explicit solver and an appropriate user-defined viscoelastic material subroutine. Results reveal that the simulation was able to pick up the general trends of how the pressure, reaction force and in-mould contact timings vary with the variation in preform temperature and air flow rate. Trends in material thickness were also accurately predicted over the length of the bottle relative to the process conditions. The knowledge gained from these analyses provides insight into the mechanisms of bottle formation, subsequently improving the blow moulding simulation and potentially providing a reduction in production costs.

Quantitative orientational characterization if low - density polyethylene blow films by x-ray and birefringence

International Nuclear Information System (INIS)

Taheri Qazvini, N.; Mohammadi, N.; Ghaffarian, R.; Assempour, H.; Haghighatkish, M.

2002-01-01

The effect of two important parameters of film blowing processes, i.e., take-up ration and blow-up ratio, on the overall orientation of low-density blown films have been investigated using birefringence measurements. Furthermore, by combining x-ray diffraction pole figure analysis and birefringence, the White and Spruiell biaxial orientation functions have been determined for aforementioned sample. Within the range of processing condition studied, increasing take-up ratio, increases orientation in both machine and transverse direction. Upon increasing blow-up ratio, orientation in the transverse direction increases and the overall orientation state approaches to equal biaxial one. Characterization of the crystalline regions by pole figure analysis reveals that a and b crystallographic axes preferentially orientate in the film plane and the direction normal to it, respectively. The amorphous regions do not have any preferential orientation

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.

On lower bounds for possible blow-up solutions to the periodic Navier-Stokes equation

International Nuclear Information System (INIS)

Cortissoz, Jean C.; Montero, Julio A.; Pinilla, Carlos E.

2014-01-01

We show a new lower bound on the H .3/2 (T 3 ) norm of a possible blow-up solution to the Navier-Stokes equation, and also comment on the extension of this result to the whole space. This estimate can be seen as a natural limiting result for Leray's blow-up estimates in L p (R 3 ), 3 .5/2 (T 3 ), and give the corresponding extension to the case of the whole space

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

Theoretical studies on the free-blowing process of the vent pipes in the pressure suppression system

International Nuclear Information System (INIS)

Aust, E.

1979-01-01

This report deals with the free-blowing period of the vent pipes in a pressure suppression system, treating especially the analytical simulation of this period. In order to do this the equations presently laid down for use in the computer codes and describing the free-blowing process are presented and their essential model simplifications are worked out. Subsequently, for the simple system of a U-tube filled with water, the fundamental mechanism of the free-blowing process is studied and the results to be transferred from it to the pressure suppression system are discussed. Based on them there are performed calculations with the individual free-blowing models using plant-related parameters as input data, in order to verify in a benchmark comparison the information and the results of calculation of the individual model concepts in relation to one another. Finally the validity of the individual model set-ups and the quality of their predictions are checked by means of experimental results from the pressure suppression experiments on the PSS test stand. (orig.) [de

FE-Analysis of Stretch-Blow Moulded Bottles Using an Integrative Process Simulation

Science.gov (United States)

Hopmann, C.; Michaeli, W.; Rasche, S.

2011-05-01

The two-stage stretch-blow moulding process has been established for the large scale production of high quality PET containers with excellent mechanical and optical properties. The total production costs of a bottle are significantly caused by the material costs. Due to this dominant share of the bottle material, the PET industry is interested in reducing the total production costs by an optimised material efficiency. However, a reduced material inventory means decreasing wall thicknesses and therewith a reduction of the bottle properties (e.g. mechanical properties, barrier properties). Therefore, there is often a trade-off between a minimal bottle weight and adequate properties of the bottle. In order to achieve the objectives Computer Aided Engineering (CAE) techniques can assist the designer of new stretch-blow moulded containers. Hence, tools such as the process simulation and the structural analysis have become important in the blow moulding sector. The Institute of Plastics Processing (IKV) at RWTH Aachen University, Germany, has developed an integrative three-dimensional process simulation which models the complete path of a preform through a stretch-blow moulding machine. At first, the reheating of the preform is calculated by a thermal simulation. Afterwards, the inflation of the preform to a bottle is calculated by finite element analysis (FEA). The results of this step are e.g. the local wall thickness distribution and the local biaxial stretch ratios. Not only the material distribution but also the material properties that result from the deformation history of the polymer have significant influence on the bottle properties. Therefore, a correlation between the material properties and stretch ratios is considered in an integrative simulation approach developed at IKV. The results of the process simulation (wall thickness, stretch ratios) are transferred to a further simulation program and mapped on the bottles FE mesh. This approach allows a local

Ultrastructure of male genitalia of blow flies (Diptera: Calliphoridae) of forensic importance.

Science.gov (United States)

Sontigun, Narin; Sanit, Sangob; Wannasan, Anchalee; Sukontason, Kom; Amendt, Jens; Yasanga, Tippawan; Sukontason, Kabkaew L

2018-03-01

Male genitalia of blow flies (Diptera: Calliphoridae) are distinctive in their morphological features and are often used for species identification. The aim of this work was to investigate the male genitalia of blow flies of medical and forensic importance from Thailand at the ultrastructural level, using scanning electron microscopy (SEM). Flies in two subfamilies were examined: Chrysomyinae [Chrysomya bezziana Villeneuve, Chrysomya chani Kurahashi, Chrysomya nigripes Aubertin, Chrysomya pinguis (Walker), Chrysomya rufifacies (Macquart), Chrysomya thanomthini Kurahashi & Tumrasvin, and Chrysomya villeneuvi Patton] and Luciliinae [Hemipyrellia ligurriens (Wiedemann), Hypopygiopsis infumata (Bigot), Hypopygiopsis tumrasvini Kurahashi, Lucilia cuprina (Wiedemann), Lucilia papuensis Macquart, Lucilia porphyrina (Walker), and Lucilia sinensis Aubertin]. Particular attention was paid to the main distinguishing features such as the shapes of the cercus and the surstylus, and the complex structure of the distiphallus. The differentiation of the male genitalia of these species at the SEM level is discussed and compared to the conditions in closely related species such as Chrysomya megacephala (Fabricius). A key for the identification of 14 blow fly species based on male genitalia is provided. Copyright © 2017 Elsevier B.V. All rights reserved.

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.

Frequency Response of Near-Wall Coherent Structures to Localized Periodic Blowing and Suction in Turbulent Boundary Layer

International Nuclear Information System (INIS)

Jian-Hua, Liu; Nan, Jiang

2008-01-01

We experimentally investigate the frequency response of near-wall coherent structures to localized periodic blowing and suction through a spanwise slot in a turbulent boundary layer by changing the frequency of periodic disturbance at similar velocities of free stream. The effects of blowing and suction disturbance on energy redistribution, turbulent intensity u' rms + , over y + and waveforms of phase-averaged velocity during sweeping process are respectively discussed under three frequencies of periodic blowing and suction in near-wall region of turbulent boundary layer, compared with those in a standard turbulent boundary layer. The most effective disturbance frequency is figured out in this system. (fundamental areas of phenomenology (including applications))

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.

Parameters of the Two-Phase Sand-Air Stream in the Blowing Process

Directory of Open Access Journals (Sweden)

Danko J.

2012-12-01

Full Text Available Theoretical problems concerning the determination of work parameters of the two-phase sand-air stream in the cores making process by blowing methods as well as experimental methods of determination of the main and auxiliary parameters of this process decisive on the cores quality assessed by the value and distribution of their apparent density are presented in the paper. In addition the results of visualisations of the core-box filling with the sand-air stream, from the blowing chamber, obtained by the process filming by means of the quick-action camera are presented in the paper and compared with the results of simulation calculations with the application of the ProCast software.

Thermo-mechanical simulation of liquid-supported stretch blow molding

International Nuclear Information System (INIS)

Zimmer, J.; Stommel, M.

2015-01-01

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

Numerical Analysis of Film Cooling at High Blowing Ratio

Science.gov (United States)

El-Gabry, Lamyaa; Heidmann, James; Ameri, Ali

2009-01-01

Computational Fluid Dynamics is used in the analysis of a film cooling jet in crossflow. Predictions of film effectiveness are compared with experimental results for a circular jet at blowing ratios ranging from 0.5 to 2.0. Film effectiveness is a surface quantity which alone is insufficient in understanding the source and finding a remedy for shortcomings of the numerical model. Therefore, in addition, comparisons are made to flow field measurements of temperature along the jet centerline. These comparisons show that the CFD model is accurately predicting the extent and trajectory of the film cooling jet; however, there is a lack of agreement in the near-wall region downstream of the film hole. The effects of main stream turbulence conditions, boundary layer thickness, turbulence modeling, and numerical artificial dissipation are evaluated and found to have an insufficient impact in the wake region of separated films (i.e. cannot account for the discrepancy between measured and predicted centerline fluid temperatures). Analyses of low and moderate blowing ratio cases are carried out and results are in good agreement with data.

Occurrence of blowing snow events at an alpine site over a 10-year period: Observations and modelling

Science.gov (United States)

Vionnet, V.; Guyomarc'h, G.; Naaim Bouvet, F.; Martin, E.; Durand, Y.; Bellot, H.; Bel, C.; Puglièse, P.

2013-05-01

Blowing snow events control the evolution of the snow pack in mountainous areas and cause inhomogeneous snow distribution. The goal of this study is to identify the main features of blowing snow events at an alpine site and assess the ability of the detailed snowpack model Crocus to reproduce the occurrence of these events in a 1D configuration. We created a database of blowing snow events observed over 10 years at our experimental site. Occurrences of blowing snow events were divided into cases with and without concurrent falling snow. Overall, snow transport is observed during 10.5% of the time in winter and occurs with concurrent falling snow 37.3% of the time. Wind speed and snow age control the frequency of occurrence. Model results illustrate the necessity of taking the wind-dependence of falling snow grain characteristics into account to simulate periods of snow transport and mass fluxes satisfactorily during those periods. The high rate of false alarms produced by the model is investigated in detail for winter 2010/2011 using measurements from snow particle counters.

Severe diffuse axon injury in chronic alcoholic rat medulla oblongata following a concussion blow.

Science.gov (United States)

Luo, Jianming; Chen, Guang; Wei, Lai; Qian, Hong; Lai, Xiaoping; Wang, Dian; Lv, Junyao; Yu, Xiaojun

2014-01-01

We investigated the axonal morphological changes and expression of both tau protein and β-APP following concussion to the medulla oblongata, in a rat model of chronic alcoholism. Fifty-nine male Sprague-Dawley rats were randomly divided into EtOH, EtOH-TBI and control groups (water group, water-TBI group). To establish chronic alcoholic rats, rats were intragastrically given edible spirituous liquor twice daily. Rats also received a blow on the occipital tuberosity with an iron pendulum. Morphological changes and expression of tau and β-APP proteins in the medulla oblongata were examined. (a) Nerve fibre thickening and twisting were observed in alcoholic rats, with nerve fibre changes becoming more significant following a concussion blow, which leads to some nerve fibres fracturing. (b) Transmission electron microscopy revealed that the nerve fibre myelin became loosened and displayed lamellar separation, which became more significant following concussion. (c) The integral optical density (IOD) sum value of β-APP of the EtOH-TBI group was lower than that in the EtOH group (P Chronic alcoholism caused nerve fibre and neuronal morphology damage in the rat medulla oblongata, with structural damage becoming more significant following concussion. (b) Concussion changed the expression of β-APP and tau protein in chronic alcoholic rat medulla oblongata, suggesting that chronic alcoholism can lead to severe axonal injury following a concussion blow. (c) The effect of chronic alcoholism may be synergistic the concussion blow to promote animal injury and death.

Importance of back blow maneuvers in a 6 month old patient with sudden upper airway obstruction

Directory of Open Access Journals (Sweden)

Pinar Gencpinar

2015-12-01

Full Text Available Foreign body aspiration in children under four years old is one of the most frequently observed reasons for accident related deaths. It is more common in this age group due to inadequate swallowing functions and exploration of objects with the mouth. The most frequently encountered foreign bodies are food and toy parts. Life threatening complete laryngeal obstruction is rarely observed. Dyspnea, hypersalivation, cough and cyanosis can be seen. The basic and life-saving treatment approach is complete removal of foreign body maneuvers in the sudden onset of total obstruction. Here we report a six-month old male, who ingested a foreign body and was treated with back blow maneuvers successfully. In this case we emphasized the importance of back blow maneuvers. Keywords: Upper airway obstruction, Child, Back blows maneuvers

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.

Convection heat transfer of closely-spaced spheres with surface blowing

Energy Technology Data Exchange (ETDEWEB)

Kleinstreuer, C. (North Carolina State Univ., Raleigh, NC (United States). Dept. of Mechanical and Aerospace Engineering); Chiang, H. (Thermofluid Technology Div., Industrial Technology Research Inst., Chutung (Taiwan, Province of China))

1993-05-01

A validated computer simulation model has been developed for the analysis of colinear spheres in a heated gas stream. Using the Galerkin finite element method, the steady-state Navier-Stokes and heat transfer equations have been solved describing laminar axisymmetric thermal flow past closely-spaced monodisperse spheres with fluid injection. Of interest are the coupled nonlinear interaction effects on the temperature fields and ultimately on the Nusselt number of each sphere for different free stream Reynolds numbers (20 [<=] Re [<=] 200) and intersphere distances (1.5 [<=] d[sub ij] [<=] 6.0) in the presence of surface blowing (0 [<=] v[sub b] [<=] 0.1). Fluid injection (i.e. blowing) and associated wake effects generate lower average heat transfer coefficients for each interacting sphere when the Reynolds number increases (Re > 100). Heat transfer is also reduced at small spacings especially for the second and third sphere. A Nusselt number correlation for each interacting (porous) sphere has been developed based on computer experiments. (orig.)

Stefan blowing effect on bioconvective flow of nanofluid over a solid rotating stretchable disk

Directory of Open Access Journals (Sweden)

N.A. Latiff

2016-12-01

Full Text Available A mathematical model for the unsteady forced convection over rotating stretchable disk in nanofluid containing micro-organisms and taking into account Stefan blowing effect is presented theoretically and numerically. Appropriate transformations are used to transform the governing boundary layer equations into non-linear ordinary differential equations, before being solved numerically using the Runge-Kutta-Fehlberg method. The effect of the governing parameters on the dimensionless velocities, temperature, nanoparticle volume fraction (concentration, density of motile microorganisms as well as on the local skin friction, local Nusselt, Sherwood number and motile microorganisms numbers are thoroughly examined via graphs. It is observed that the Stefan blowing increases the local skin friction and reduces the heat transfer, mass transfer and microorganism transfer rates. The numerical results are in good agreement with those obtained from previous literature. Physical quantities results from this investigation show that the effects of higher disk stretching strength and suction case provides a good medium to enhance the heat, mass and microorganisms transfer compared to blowing case.

Blow-up of solutions to the rotation b-family system modeling equatorial water waves

Directory of Open Access Journals (Sweden)

Min Zhu

2018-03-01

Full Text Available We consider the blow-up mechanism to the periodic generalized rotation b-family system (R-b-family system. This model can be derived from the f-plane governing equations for the geographical water waves with a constant underlying current in the equatorial water waves with effect of the Coriolis force. When b=2, it is a rotation two-component Camassa-Holm (R2CH system. We consider the periodic R2CH system when linear dispersion is absent (which model is called r2CH system and derive two finite-time blow-up results.

An electrostatic charge measurement of blowing snow particles focusing on collision frequency to the snow surface

Science.gov (United States)

Omiya, S.; Sato, A.

2010-12-01

Blowing snow particles are known to have an electrostatic charge. This charge may be a contributing factor in the formation of snow drifts and snow cornices and changing of the trajectory of blowing snow particles. These formations and phenomena can cause natural disaster such as an avalanche and a visibility deterioration, and obstruct transportation during winter season. 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 primary factor of charge accumulation to the blowing snow particles is thought to be due to “saltation” of them. The “saltation” is one of movement forms of blowing snow: when the snow particles are transported by the wind, they repeat frictional collisions with the snow surface. In previous studies, charge-to-mass ratios measured in the field were approximately -50 to -10 μC/kg, and in the wind tunnel were approximately -0.8 to -0.1 μC/kg. While there were qualitatively consistent in sign, negative, there were huge gaps quantitatively between them. One reason of those gaps is speculated to be due to differences in fetch. In other words, the difference of the collision frequency of snow particles to the snow surface has caused the gaps. But it is merely a suggestion and that has not been confirmed. The purpose of this experiment is to measure the charge of blowing snow particles focusing on the collision frequency and clarify the relationship between them. Experiments were carried out in the cryogenic wind tunnel of Snow and Ice Research Center (NIED, JAPAN). A Faraday cage and an electrometer were used to measure the charge of snow particles. These experiments were conducted over the hard snow surface condition to prevent the erosion of the snow surface and the generation of new snow particles from the surface. The collision frequency of particle was controlled by changing the wind velocity (4.5 to 7 m/s) under

Nose micro-blowing for asymmetric vortices control on blunt-nose slender body at high angle of attack

Directory of Open Access Journals (Sweden)

Lei Wang

2017-11-01

Full Text Available The asymmetric vortices over blunt-nose slender body at high angles of attack result in random side force. In this paper, a nose micro-blowing technology is used to control the asymmetric flow. Pressure measurement and particle image velocimetry (PIV experiments are conducted in a low-speed wind tunnel to research effects of jet flow rate on asymmetric vortices over blunt-nose slender body. The angle of attack of the model is fixed at 50° and the Reynolds number for the experiments is 1.6×10 5 based on diameter of aftbody. A blow hole (5 mm in diameter on the nose is processed at circumferential angle θb= 90° and meridian angle γb= 20° with jet momentum ratio Cμ ranging from 5.30×10-7 to 1.19×10−4. Tests are made under two kinds of perturbations. One is called single perturbation with only blow hole and the other is called combined perturbation consists of blow hole and additional granules set on nose. The results show that whether the model has the single perturbation or the combined one, the sectional side force of x/D = 3 varies in the same direction with the increasement of Cμ and remains stable when Cμ is greater than 3.29×10−6. But the stable force values are different according to various perturbations. The fact proves that the size and direction of the side force of blunt-nose slender body can be controlled by the nose micro-blowing.

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.

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.

Self-contained anti-static adapter for compressed gas dust blowing devices

International Nuclear Information System (INIS)

Schwartz, L.H.; Miller, S.W.; Severud, C.N. Jr.

1984-01-01

An anti-static adapter which enhances the operation of compressed gas dust blowing devices by allowing the safe use of a radioactive source to ionize a gas stream. The adapter may be used and handled safely without special precautions on the part of the operator

Asymptotic analysis of reaction-diffusion-advection problems: Fronts with periodic motion and blow-up

Science.gov (United States)

Nefedov, Nikolay

2017-02-01

This is an extended variant of the paper presented at MURPHYS-HSFS 2016 conference in Barcelona. We discuss further development of the asymptotic method of differential inequalities to investigate existence and stability of sharp internal layers (fronts) for nonlinear singularly perturbed periodic parabolic problems and initial boundary value problems with blow-up of fronts for reaction-diffusion-advection equations. In particular, we consider periodic solutions with internal layer in the case of balanced reaction. For the initial boundary value problems we prove the existence of fronts and give their asymptotic approximation including the new case of blowing-up fronts. This case we illustrate by the generalised Burgers equation.

10 blows that stopped nuclear power

International Nuclear Information System (INIS)

Komanoff, C.

1991-01-01

The author describes these 10 blows in chronological order, 1973 through 1981, namely: (1) Arab Oil Embargo; (2) India Explodes a Bomb; (3) NRC replaces AEC; (4) Fire at Browns Ferry; (5) General Electric and NRC Engineers switch Sides; (6) Amory Lovins Recasts the Energy Debate; (7) The Seabrook Occupation; (8) The Three Mile Island Accident; (9) Federal Reserve Tightens the Money Supply; and (1) Pacific Gas and Electric Co. Gets it Backwards at Diablo Canyon. he stops there, not including the Washington Public Power Supply fiasco and the Chernobyl disaster, feeling nuclear expansion was essentially foreclosed without them. Further, he feels nuclear power seems fated to be forever at the mercy of forces beyond its control

Oscillation of Vortex Breakdown Location and Blowing Control of Time-Averaged Location

National Research Council Canada - National Science Library

Mitchell, Anthony

2000-01-01

The goal of this research is the control of leading-edge vortex breakdown location utilizing along-the-core blowing near the apex on the leeward surface of sharp-edged, slender, delta wings at high angles of attack...

Species composition of carrion blow flies in northern Thailand: altitude appraisal.

Science.gov (United States)

Moophayak, Kittikhun; Klong-Klaew, Tunwadee; Sukontason, Kom; Kurahashi, Hiromu; Tomberlin, Jeffery K; Sukontason, Kabkaew L

2014-01-01

Distribution and occurrence of blow flies of forensic importance was performed during 2007 and 2008 in Chiang Mai and Lampang Provinces, northern Thailand. Surveys were conducted in forested areas for 30 minutes using a sweep net to collected flies attracted to a bait. A total of 2,115 blow flies belonging to six genera and 14 species were collected; Chrysomya megacephala (Fabricius) (44.7%), C. pinguis (Walker) (15.1%), C. chani Kurahashi (9.3%), C. thanomthini Kurahashi & Tumrasvin (0.3%); Achoetandrus rufifacies (Macquart) (10.5%), A. villeneuvi (Patton) (2.2%); Lucilia papuensis Macquart (2.2%), L. porphyrina (Walker) (12.4%), L. sinensis Aubertin (0.7%); Hemipyrellia ligurriens (Wiedemann) (1.3%), H. pulchra (Wiedemann) (0.1%); Hypopygiopsis infumata (Bigot) (0.6%), Hy. tumrasvini Kurahashi (0.2%) and Ceylonomyia nigripes Aubertin (0.4%). Among them, C. megacephala was the predominant species collected, particularly in the summer. The species likely to prevail in highland areas are C. pinguis, C. thanomthini, Hy. tumrasvini, L. papuensis and L. porphyrina.

SPECIES COMPOSITION OF CARRION BLOW FLIES IN NORTHERN THAILAND: ALTITUDE APPRAISAL

Directory of Open Access Journals (Sweden)

Kittikhun Moophayak

2014-04-01

Full Text Available Distribution and occurrence of blow flies of forensic importance was performed during 2007 and 2008 in Chiang Mai and Lampang Provinces, northern Thailand. Surveys were conducted in forested areas for 30 minutes using a sweep net to collected flies attracted to a bait. A total of 2,115 blow flies belonging to six genera and 14 species were collected; Chrysomya megacephala (Fabricius (44.7%, C. pinguis (Walker (15.1%, C. chani Kurahashi (9.3%, C. thanomthini Kurahashi & Tumrasvin (0.3%; Achoetandrus rufifacies (Macquart (10.5%, A. villeneuvi (Patton (2.2%; Lucilia papuensis Macquart (2.2%, L. porphyrina (Walker (12.4%, L. sinensis Aubertin (0.7%; Hemipyrellia ligurriens(Wiedemann (1.3%, H. pulchra(Wiedemann (0.1%; Hypopygiopsis infumata (Bigot (0.6%, Hy. tumrasvini Kurahashi (0.2% and Ceylonomyia nigripes Aubertin (0.4%. Among them, C. megacephala was the predominant species collected, particularly in the summer. The species likely to prevail in highland areas are C. pinguis, C. thanomthini, Hy. tumrasvini, L. papuensis and L. porphyrina.

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.

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

KAUST Repository

Kedia, Kushal S.; Ghoniem, Ahmed F.

2015-01-01

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

Simulation on the Effect of Bottle Wall Thickness Distribution using Blow Moulding Technique

International Nuclear Information System (INIS)

Suraya, S; Azman, M D; Fatchurrohman, N; Jaafar, A A; Yusoff, A R

2016-01-01

The aims of this study are to assess the deformation behavior of a polymeric material during a blow moulding process. Transient computations of two dimensional model of a PP bottle were performed using ANSYS Polyflow computer code to predict the wall thickness distribution at four different parison's diameter; 8mm, 10mm, 18mm, and 20mm. Effects on the final wall thickness diameter and time step are studied. The simulated data shows that the inflation performance degrades with increasing parison diameter. It is concluded that the blow moulding process using 10mm parison successfully meet the product processing requirements. Factors that contribute to the variation in deformation behaviour of the plastic during the manufacturing process are discussed. (paper)

Synthesis of a novel adaptive wavelet optimized neural cascaded steam blow-off control system for a nuclear power plant

International Nuclear Information System (INIS)

Malik, A.H.; Memon, A.A.; Arshad, F.

2013-01-01

Blow-Off System Controller (MIMO AWNN-SBOSC) is designed based on real time dynamic parametric plant data of steam blow-off system with conventional Single-Input Multi-Output Proportional plus Integral plus Derivative Controller (SIMO PIDC). The proposed MIMO AWANN-SBOSC is designed using three Multi-Input Single-Output Adaptive Wavelet Neural Network based Steam Blow-Off System Controllers (MISO AWNN-SBOSC). The hidden layer of each MISO AWNN-SBOSC is formulated using Mother Wavelet Transforms (MWT). Using nonlinear dynamic neural data of designed MIMO AWNN-SBOSC, a Multi-Input Multi-Output Adaptive Wavelet Neural Network based Steam Blow-Off System Model (MIMO AWNN-SBOSM) is developed in cascaded mode. MIMO AWNN-SBOSM is designed using two MISO AWNN-SBOSM. All training, testing and validation of MIMO AWNN-SBOSC and MIMO AWNN-SBOSM are carried out in MA TLAB while all simulation experiments are performed in Visual C. The results of the new design is evaluated against conventional controller based measured data and found robust, fast and much better in performance. (author)

Estimating the Number of Eggs in Blow Fly (Diptera: Calliphoridae) Egg Masses Using Photographic Analysis.

Science.gov (United States)

Rosati, J Y; Pacheco, V A; Vankosky, M A; Vanlaerhoven, S L

2015-07-01

Little work has been done to quantify the number of eggs oviposited by blow flies (Diptera: Calliphoridae) in studies examining colonization behavior. Egg counting methods currently available are time-consuming and destructive. This study used ImageJ software and analysis of covariance to relate the volume of egg masses to the number of eggs laid by three different blow fly species: Lucilia sericata (Meigen), Phormia regina (Meigen), and Chrysomya rufifacies (Macquart). Egg mass volume, species, and the interaction of species and egg mass volume all affected the number of blow fly eggs deposited in egg masses. Both species identity and egg mass volume are important when predicting egg number, as such a single regression equation cannot be used to estimate egg number for these three species. Therefore, simple linear regression equations were determined for each species. The volume of individual eggs was incorporated into the model, yet differences between species were observed, suggesting that the orientation of the eggs oviposited by multiple conspecific females within egg masses influences egg estimates. Based on our results, we expect that imaging software can be used for other blow fly species, as well as other insect species; however, equations specific to each species must be developed. This study describes an important tool for quantifying egg deposition in a nondestructive manner, which is important in studying the colonization behavior and life history of insects of ecological and forensic importance. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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...

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

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

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

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

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 (padhesive systems 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.

Effects of environmental temperature on oviposition behavior in three blow fly species of forensic importance.

Science.gov (United States)

Ody, Helen; Bulling, Mark T; Barnes, Kate M

2017-06-01

A number of factors are known to affect blow fly behavior with respect to oviposition. Current research indicates that temperature is the most significant factor. However temperature thresholds for oviposition in forensically important blow flies have not been well studied. Here, the oviposition behavior of three species of forensically important blow fly species (Calliphora vicina, Calliphora vomitoria and Lucilia sericata,) was studied under controlled laboratory conditions over a range of temperatures (10-40°C). Lower temperature thresholds for oviposition of 16°C and 17.5°C were established for C. vomitoria and L. sericata respectively, whilst C. vicina continued to lay eggs at 10°C. C. vomitoria and L. sericata both continued to lay eggs at 40°C, whilst the highest temperature at which oviposition occurred in C. vicina was 35°C. Within these thresholds there was considerable variation in the number of surviving pupae, with a general pattern of a single peak within the range of temperatures at which eggs were laid, but with the pattern being much less distinct for L. sericata. Copyright © 2017 Elsevier B.V. All rights reserved.

Interferometric measurement of film thickness during bubble blowing

Science.gov (United States)

Wang, Z.; Mandracchia, B.; Ferraro, V.; Tammaro, D.; Di Maio, E.; Maffettone, P. L.; Ferraro, P.

2017-06-01

In this paper, we propose digital holography in transmission configuration as an effective method to measure the time-dependent thickness of polymeric films during bubble blowing. We designed a complete set of experiments to measure bubble thickness, including the evaluation of the refractive index of the polymer solution. We report the measurement of thickness distribution along the film during the bubble formation process until the bubble`s rupture. Based on those data, the variation range and variation trend of bubble film thickness are clearly measured during the process of expansion to fracture is indicated.

INCOMPRESSIBLE LAMINAR BOUNDARY LAYER CONTROL BY BLOWING AND SUCTION

OpenAIRE

AZZEDINE NAHOUI; LAKHDAR BAHI

2013-01-01

A two-dimensional incompressible laminar boundary layer and its control using blowing and suction over a flat plate and around the NACA 0012 and 661012 profiles, is studied numerically. The study is based on the Prandtl boundary layer model using the finite differences method and the Crank-Nicolson scheme. The velocity distribution, the boundary layer thickness and the friction coefficient, are determined and presented with and without control. The application of the control technique, has de...

Blow.MOD2: a program for blowdown transient calculations

International Nuclear Information System (INIS)

Doval, A.

1990-01-01

The BLOW.MOD2 program has been developed to calculate the blowdown phase in a pressurized vessel after a break/valve is opened. It is a one volume model where break height and flow area are specified. Moody critical flow model was adopted under saturation conditions for flow calculation through the break. Heat transfer from structures and internals have been taken into account. Long term depressurization results and a more complex model are compared satisfactorily. (Author)

Blow-up in multidimensional aggregation equations with mildly singular interaction kernels

International Nuclear Information System (INIS)

Bertozzi, Andrea L; Laurent, Thomas; Carrillo, José A

2009-01-01

We consider the multidimensional aggregation equation u t − ∇· (u∇K * u) = 0 in which the radially symmetric attractive interaction kernel has a mild singularity at the origin (Lipschitz or better). In the case of bounded initial data, finite time singularity has been proved for kernels with a Lipschitz point at the origin (Bertozzi and Laurent 2007 Commun. Math. Sci. 274 717–35), whereas for C 2 kernels there is no finite-time blow-up. We prove, under mild monotonicity assumptions on the kernel K, that the Osgood condition for well-posedness of the ODE characteristics determines global in time well-posedness of the PDE with compactly supported bounded nonnegative initial data. When the Osgood condition is violated, we present a new proof of finite time blow-up that extends previous results, requiring radially symmetric data, to general bounded, compactly supported nonnegative initial data without symmetry. We also present a new analysis of radially symmetric solutions under less strict monotonicity conditions. Finally, we conclude with a discussion of similarity solutions for the case K(x) = |x| and some open problems

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.

Low-Speed Wind-Tunnel Investigation of Blowing Boundary-Layer Control on Leading- and Trailing-Edge Flaps of a Large-Scale, Low-Aspect-Ratio, 45 Swept-wing Airplane Configuration

Science.gov (United States)

Maki, Ralph L.

1959-01-01

Blowing boundary-layer control was applied to the leading- and trailing-edge flaps of a 45 deg sweptback-wing complete model in a full-scale low-speed wind-tunnel study. The principal purpose of the study was to determine the effects of leading-edge flap deflection and boundary-layer control on maximum lift and longitudinal stability. Leading-edge flap deflection alone was sufficient to maintain static longitudinal stability without trailing-edge flaps. However, leading-edge flap blowing was required to maintain longitudinal stability by delaying leading-edge flow separation when trailing-edge flaps were deflected either with or without blowing. Partial-span leading-edge flaps deflected 60 deg with moderate blowing gave the major increase in maximum lift, although higher deflection and additional blowing gave some further increase. Inboard of 0.4 semispan leading-edge flap deflection could be reduced to 40 deg and/or blowing could be omitted with only small loss in maximum lift. Trailing-edge flap lift increments were increased by boundary-layer control for deflections greater than 45 deg. Maximum lift was not increased with deflected trailing-edge flaps with blowing.

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

Indian Academy of Sciences (India)

tion and generation of noise continue to attract the attention of researchers .... the crest width was maintained as one-fifth of the full cycle, thereby making the blowing .... result in any discernible change in the velocity profile far from the base region, x/h = 5, .... Proceedings of the 44th IEEE Conf. on Decision and Control, and.

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.

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…

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)

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.

Extraordinary blowing snow transport events in East Antarctica

Energy Technology Data Exchange (ETDEWEB)

Scarchilli, Claudio; Agnoletto, Lucia [ENEA, Rome (Italy); Universita di Siena, Dipartimento di Scienze della Terra, Siena (Italy); Frezzotti, Massimo; Grigioni, Paolo; Silvestri, Lorenzo de [ENEA, Rome (Italy); Dolci, Stefano [CNR, Rome (Italy); Consorzio P.N.R.A. S.C.r.l., Rome (Italy)

2010-06-15

In the convergence slope/coastal areas of Antarctica, a large fraction of snow is continuously eroded and exported by wind to the atmosphere and into the ocean. Snow transport observations from instruments and satellite images were acquired at the wind convergence zone of Terra Nova Bay (East Antarctica) throughout 2006 and 2007. Snow transport features are well-distinguished in satellite images and can extend vertically up to 200 m as first-order quantitatively estimated by driftometer sensor FlowCapt trademark. Maximum snow transportation occurs in the fall and winter seasons. Snow transportation (drift/blowing) was recorded for {proportional_to}80% of the time, and 20% of time recorded, the flux is >10{sup -2} kg m{sup -2} s{sup -1} with particle density increasing with height. Cumulative snow transportation is {proportional_to}4 orders of magnitude higher than snow precipitation at the site. An increase in wind speed and transportation ({proportional_to}30%) was observed in 2007, which is in agreement with a reduction in observed snow accumulation. Extensive presence of ablation surface (blue ice and wind crust) upwind and downwind of the measurement site suggest that the combine processes of blowing snow sublimation and snow transport remove up to 50% of the precipitation in the coastal and slope convergence area. These phenomena represent a major negative effect on the snow accumulation, and they are not sufficiently taken into account in studies of surface mass balance. The observed wind-driven ablation explains the inconsistency between atmospheric model precipitation and measured snow accumulation value. (orig.)

Determinants and impediments of whistle-blowing in local government councils: A case study of the South-East District Council, Botswana

Directory of Open Access Journals (Sweden)

Abiodun M.T. Omotoye

2017-11-01

Full Text Available This article investigates the perceptions of public service employees regarding the role of whistle-blowing in local government. Whistle-blowing has received increased attention and support as a means of detecting and correcting wrongdoing in organisations. Yet, as this case study discusses, the absence of whistle-blower protection measures and fear of reprisal and job loss deter potential witnesses from reporting wrongdoing in the workplace. A mixed research method approach was employed to undertake the study. A self-administered questionnaire was distributed to public servants employed within the South-East District Council (SEDC and literature related to corruption and whistle-blowing was reviewed. The findings indicate that public service employees strongly support the role whistle-blowing has to play in curbing corruption in the workplace, particularly if the corrupt activity could potentially threaten people’s lives and suppress social justice. However, the absence of whistle-blower protection measures was cited as the most significant impediment to reporting wrongdoing. The article proposes the need for the SEDC to adopt effective policies and procedures that place a strong emphasis on providing protection for employees to disclose misconduct and fraudulent conduct.

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.

Criteria on global boundedness versus finite time blow-up to a two-species chemotaxis system with two chemicals

Science.gov (United States)

Yu, Hao; Wang, Wei; Zheng, Sining

2018-02-01

This paper considers the two-species chemotaxis system with two chemicals in a smooth bounded domain Ω\\subset{R}2 , subject to the non-flux boundary condition, and χ, ξ, α, β, γ, δ>0 . We obtain a blow-up criterion that if m_1m_2-2π(\\frac{m_1}χβ+\\frac{m_2}ξδ)>0 , then there exist finite time blow-up solutions to the system with m_1:=\\int_Ω u_0(x)dx and m_2:=\\int_Ω w_0(x)dx . When χ=ξ= β=δ=1 , the blow-up criterion becomes m_1m_2-2π(m_1+m_2)>0 , and the global boundedness of solutions is furthermore established with α=γ=1 under the condition that \\max\\{m_1, m_2\\}4π and global boundedness with \\max\\{m_1, m_2\\}Funds for the Central Universities (DUT16LK24).

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

OpenAIRE

Peek, L., M; Roxas, G. Peek; Robichaud, B; Covarrubias; J. Barragan

2005-01-01

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 scenar...

Development of blow down and sodium-water reaction jet analysis codes-Validation by sodium-water reaction tests (SWAT-1R)

International Nuclear Information System (INIS)

Hiroshi Seino; Akikazu Kurihara; Isao Ono; Koji Jitsu

2005-01-01

Blow down analysis code (LEAP-BLOW) and sodium-water reaction jet analysis code (LEAP-JET) have been developed in order to improve the evaluation method on sodium-water reaction event in the steam generator (SG) of a sodium cooled fast breeder reactor (FBR). The validation analyses by these two codes were carried out using the data of Sodium-Water Reaction Test (SWAT-1R). The following main results have been obtained through this validation: (1) The calculational results by LEAP-BLOW such as internal pressure and water flow rate show good agreement with the results of the SWAT- 1R test. (2) The LEAP-JET code can qualitatively simulate the behavior of sodium-water reaction. However, it is found that the code has tendency to overestimate the maximum temperature of the reaction jet. (authors)

Pattern injuries from blows with the muzzle end of a handgun.

Science.gov (United States)

Geisenberger, D; Vogt, S; Pircher, R; Kramer, L; Pollak, S; Große Perdekamp, M

2015-12-01

Pistols, revolvers and blank guns are not only used to discharge cartridges, but also for hits to the victim. In such cases, the blows preferably affect the head and/or the interposed hands protecting the body. The impact is mostly exerted either by the grip of a pistol or the butt of a revolver. In vigorous thrusts inflicted with the muzzle end of the weapon, the edge of the barrel may produce circular punch lesions with central skin flaps roughly corresponding to the bore. As in other kinds of pistol-whipping, the scalp wounds may be associated with fractures of the skull and even with brain contusions. Using the example of a homicide committed by pistol-whipping, the morphological features of blunt injuries from a handgun's muzzle are presented. The characteristic wound pattern found on the victim's head could be reproduced experimentally by forceful blows to the forehead of a slaughtered pig. In the case presented, the dominant hand of the perpetrator showed friction blisters due to prolonged striking with an unhandy tool in the form of a pistol. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

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...... was to evaluate the potential for degradation of BAs in landfills, and to develop a landfill model, which could simulate the fate of BAs in landfills. The investigation was performed by use of anaerobic microcosm studies using different types of organic waste and anaerobic digested sludge as inoculum. The BAs...... 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...

Metabolism of 1-fluoro-1,1,2-trichloroethane, 1,2-dichloro-1,1-difluoroethane, and 1,1,1-trifluoro-2-chloroethane.

Science.gov (United States)

Yin, H; Jones, J P; Anders, M W

1995-03-01

1-Fluoro-1,1,2-trichloroethane (HCFC-131a), 1,2-dichloro-1,1-difluoroethane (HCFC-132b), and 1,1,1-trifluoro-2-chloroethane (HCFC-133a) were chosen as models for comparative metabolism studies on 1,1,1,2-tetrahaloethanes, which are under consideration as replacements for ozone-depleting chlorofluorocarbons (CFCs). Male Fischer 344 rats were given 10 mmol/kg ip HCFC-131a or HCFC-132b or exposed by inhalation to 1% HCFC-133a for 2 h. Urine collected in the first 24 h after exposure was analyzed by 19F NMR and GC/MS and with a fluoride-selective ion electrode for the formation of fluorine-containing metabolites. Metabolites of HCFC-131a included 2,2-dichloro-2-fluoroethyl glucuronide, 2,2-dichloro-2-fluoroethyl sulfate, dichlorofluoroacetic acid, and inorganic fluoride. Metabolites of HCFC-132b were characterized as 2-chloro-2,2-difluoroethyl glucuronide, 2-chloro-2,2-difluoroethyl sulfate, chlorodifluoroacetic acid, chlorodifluoroacetaldehyde hydrate, chlorodifluoroacetaldehyde-urea adduct, and inorganic fluoride. HCFC-133a was metabolized to 2,2,2-trifluoroethyl glucuronide, trifluoroacetic acid, trifluoroacetaldehyde hydrate, trifluoroacetaldehyde-urea adduct, inorganic fluoride, and a minor, unidentified metabolite. With HCFC-131a and HCFC-132b, glucuronide conjugates of 2,2,2-trihaloethanols were the major urinary metabolites, whereas with HCFC-133a, a trifluoroacetaldehyde-urea adduct was the major urinary metabolite. Analysis of metabolite distribution in vivo indicated that aldehydic metabolites increased as fluorine substitution increased in the order HCFC-131a < HCFC-132b < HCFC-133a. With NADPH-fortified rat liver microsomes, HCFC-133a and HCFC-132b were biotransformed to trifluoroacetaldehyde and chlorodifluoroacetaldehyde, respectively, whereas HCFC-131a was converted to dichlorofluoroacetic acid. No covalently bound metabolites were detected by 19F NMR spectroscopy.(ABSTRACT TRUNCATED AT 250 WORDS)

Simple gases to replace non-environmentally friendly polymer foaming agents. A thermodynamic investigation

International Nuclear Information System (INIS)

Grolier, Jean-Pierre E.; Randzio, Stanislaw L.

2012-01-01

Highlights: ► The PVT-vibrating wire technique and PVT-scanning transitiometry. ► Polymer swelling with measured gas sorption and gas–polymer interaction energies. ► Experimental measurements up to 373 K and 100 MPa. ► Hydrostatic and plasticization effects under high pressure gas and induced T g -shifts. ► Thermodynamic study of the (gas + polymer) systems polystyrene with CO 2 , N 2 , and freons. - Abstract: Foaming constitutes one of the most important industrial activities in polymer engineering to produce efficient thermal insulating materials. In particular, rigid insulating boards are produced worldwide on a large scale using blowing agents which eventually are released in the environment where they adversely impact the natural friendly stratospheric ozone layer. Concomitantly, the chemicals used as blowing agents contribute to the creation of the unfriendly tropospheric ozone layer generating the disastrous green house effect around our planet. The traditional foaming intermediates currently named freons, like chlorofluorocarbons (CFCs) currently used as blowing agents as well as the hydrochlorofluorocarbons (HCFCs) often considered as alternative blowing agents, must be banned from industrial processes and new (friendly) foaming agents have to be suggested and evaluated in terms of both easy engineering and environmental neutrality. Undoubtedly thermodynamics plays a major role in assessing the effective capability of those chemicals. Some CFCs still accepted and other possible simple gases like carbon dioxide and nitrogen have been considered. The in-depth thermodynamic investigation has been made possible thanks to new experimental developments to determine gas solubility in polymers and associated swelling as well as the thermodynamic properties of (gas + polymer) systems, including the thermophysical properties of polymers under gas sorption. Pertinent data have been generated for such properties over extended T and p ranges.

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

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

International Nuclear Information System (INIS)

Bhattacharyya, Krishnendu; Layek, G. C.

2011-01-01

An analysis is carried out to study a steady magnetohydrodynamic (MHD) boundary layer flow 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 physically. (fundamental areas of phenomenology(including applications))

Numerical modelling of heat transfer in a cavity due to liquid jet impingement for liquid supported stretch blow moulding

Science.gov (United States)

Smyth, Trevor; Menary, Gary; Geron, Marco

2018-05-01

Impingement of a liquid jet in a polymer cavity has been modelled numerically in this study. Liquid supported stretch blow moulding is a nascent polymer forming process using liquid as the forming medium to produce plastic bottles. The process derives from the conventional stretch blow moulding process which uses compressed air to deform the preform. Heat transfer away from the preform greatly increases when a liquid instead of a gas is flowing over a solid; in the blow moulding process the temperature of the preform is tightly controlled to achieve optimum forming conditions. A model was developed with Computational Fluid Dynamics code ANSYS Fluent which allows the extent of heat transfer between the incoming liquid and the solid preform to be determined in the initial transient stage, where a liquid jet enters an air filled preform. With this data, an approximation of the extent of cooling through the preform wall can be determined.

On blow-up of solutions of the Kuramoto-Sivashinsky equation

International Nuclear Information System (INIS)

Pokhozhaev, S I

2008-01-01

The problem of the absence of global solutions of initial-boundary value problems for the Kuramoto-Sivashinsky equation is considered. Sufficient conditions for the absence of global solutions of the problems under consideration are obtained both for bounded and unbounded domains. These conditions imply a priori the blow-up of the solution of the corresponding initial-boundary value problem. The proof uses a generalization of the method of non-linear capacity based on the choice of asymptotically optimal test functions. Bibliography: 20 titles.

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.

Clinical features and MRI findings of blow-out fracture

Energy Technology Data Exchange (ETDEWEB)

Yamanouchi, Yasuo; Yasuda, Takasumi; Kawamoto, Keiji [Kansai Medical Univ., Moriguchi, Osaka (Japan); Inagaki, Takayuki; Someda, Kuniyuki

1996-06-01

Precise anatomical understanding of orbital blow-out fracture lesions is necessary for the treatment of patients. Retrospectively, MRI findings were compared with the clinical features of pure type blow-out fractures and the efficacy of MRI in influencing a decision for surgical intervention was evaluated. Eighteen child (15 boys, 3 girls) cases were evaluated and compared with adult cases. The patients were classified into three categories (Fig.1) and two types (Fig.2) in accordance with the degree of protrusion of fat tissue. The degree of muscle protrusion also was divided into three categories (Fig. 3). Both muscle and fat tissue were protruding from the fracture site in 14 cases. Fat tissue protrusion alone was found in 3 cases. In contrast, no protrusion was seen in one case. The incarcerated type of fat prolapse was found in 40% of cases, while muscle tissue prolapse was found in 75% of patients. Marginal irregularity or swelling of muscle was observed in 11 patients. There was good correlation of ocular motor disturbance and MRI findings. Disturbance of eyeball movement was observed in all patients with either incarcerated fat tissue or marginal irregularity or swelling of muscle. In contrast, restriction of eyeball movement was rare in cases of no incarceration, even if the fracture was wide. Deformity or marginal irregularity of the ocular muscle demonstrated in MRI may suggest damage an adhesion to the muscle wall. When MRI reveals incarceration or severe prolapse of fat tissue, or deformity and marginal irregularity of the ocular muscle, surgical intervention should be considered. (author)

Clinical features and MRI findings of blow-out fracture

International Nuclear Information System (INIS)

Yamanouchi, Yasuo; Yasuda, Takasumi; Kawamoto, Keiji; Inagaki, Takayuki; Someda, Kuniyuki.

1996-01-01

Precise anatomical understanding of orbital blow-out fracture lesions is necessary for the treatment of patients. Retrospectively, MRI findings were compared with the clinical features of pure type blow-out fractures and the efficacy of MRI in influencing a decision for surgical intervention was evaluated. Eighteen child (15 boys, 3 girls) cases were evaluated and compared with adult cases. The patients were classified into three categories (Fig.1) and two types (Fig.2) in accordance with the degree of protrusion of fat tissue. The degree of muscle protrusion also was divided into three categories (Fig. 3). Both muscle and fat tissue were protruding from the fracture site in 14 cases. Fat tissue protrusion alone was found in 3 cases. In contrast, no protrusion was seen in one case. The incarcerated type of fat prolapse was found in 40% of cases, while muscle tissue prolapse was found in 75% of patients. Marginal irregularity or swelling of muscle was observed in 11 patients. There was good correlation of ocular motor disturbance and MRI findings. Disturbance of eyeball movement was observed in all patients with either incarcerated fat tissue or marginal irregularity or swelling of muscle. In contrast, restriction of eyeball movement was rare in cases of no incarceration, even if the fracture was wide. Deformity or marginal irregularity of the ocular muscle demonstrated in MRI may suggest damage an adhesion to the muscle wall. When MRI reveals incarceration or severe prolapse of fat tissue, or deformity and marginal irregularity of the ocular muscle, surgical intervention should be considered. (author)

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.

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

Science.gov (United States)

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

2009-07-07

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

High-global warming potential F-gas emissions in California: comparison of ambient-based versus inventory-based emission estimates, and implications of refined estimates.

Science.gov (United States)

Gallagher, Glenn; Zhan, Tao; Hsu, Ying-Kuang; Gupta, Pamela; Pederson, James; Croes, Bart; Blake, Donald R; Barletta, Barbara; Meinardi, Simone; Ashford, Paul; Vetter, Arnie; Saba, Sabine; Slim, Rayan; Palandre, Lionel; Clodic, Denis; Mathis, Pamela; Wagner, Mark; Forgie, Julia; Dwyer, Harry; Wolf, Katy

2014-01-21

To provide information for greenhouse gas reduction policies, the California Air Resources Board (CARB) inventories annual emissions of high-global-warming potential (GWP) fluorinated gases, the fastest growing sector of greenhouse gas (GHG) emissions globally. Baseline 2008 F-gas emissions estimates for selected chlorofluorocarbons (CFC-12), hydrochlorofluorocarbons (HCFC-22), and hydrofluorocarbons (HFC-134a) made with an inventory-based methodology were compared to emissions estimates made by ambient-based measurements. Significant discrepancies were found, with the inventory-based emissions methodology resulting in a systematic 42% under-estimation of CFC-12 emissions from older refrigeration equipment and older vehicles, and a systematic 114% overestimation of emissions for HFC-134a, a refrigerant substitute for phased-out CFCs. Initial, inventory-based estimates for all F-gas emissions had assumed that equipment is no longer in service once it reaches its average lifetime of use. Revised emission estimates using improved models for equipment age at end-of-life, inventories, and leak rates specific to California resulted in F-gas emissions estimates in closer agreement to ambient-based measurements. The discrepancies between inventory-based estimates and ambient-based measurements were reduced from -42% to -6% for CFC-12, and from +114% to +9% for HFC-134a.

Estimating total 239240Pu in blow-sand mounds of two safety-shot sites

International Nuclear Information System (INIS)

Gilbert, R.O.; Essington, E.H.

1977-01-01

A study for estimating the total amount (inventory) of 239 240 Pu in blow-sand mounds at two safety-shot sites (Area 13-Project 57 on the Nellis Air Force Base and Clean Slate 3 on the Tonopah Test Range in Nevada) is described. The total amount in blow-sand mounds at these two sites is estimated to be 5.8 +- 1.3 (total +- standard error) and 10.6 +- 2.5 curies, respectively. The total 239 240 Pu in mounds plus desert pavement areas, both to a depth of 5 cm below desert pavement level, is estimated to be 39 +- 5.7 curies at the Project 57 site and 36 +- 4.8 curies at Clean Slate 3. These estimates are compared with the somewhat higher estimates of 46 +- 9 and 37 +- 5.4 curies reported that pertain to only the top 5 cm of mounds and desert pavement. The possibility is discussed that these differences are due to sampling variability arising from the skewed nature of plutonium concentrations, particularly near ground zero

Modeling blowing snow accumulation downwind of an obstruction: The Ohara Eulerian particle distribution equation

Science.gov (United States)

Kinar, N. J.

2017-05-01

An equation was proposed to model the height of blowing snow accumulation downwind of an obstacle such as vegetation, a snow fence, a building, or a topographic feature. The equation does not require aerodynamic flow condition parameters such as wind speed, allowing for the spatial distribution of snow to be determined at locations where meteorological data is not available. However, snow particle diffusion, drift, and erosion coefficients must be estimated for application of the equation. These coefficients can be used to provide insight into the relative magnitude of blowing snow processes at a field location. Further research is required to determine efficient methods for coefficient estimation. The equation could be used with other models of wind-transported snow to predict snow accumulation downwind of an obstacle without the need for wind speed adjustments or correction equations. Applications for this equation include the design of snow fences, and the use of this equation with other hydrological models to predict snow distribution, climate change, drought, flooding, and avalanches.

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

Blow/trauma to the chest and sudden cardiac death: Commotio cordis and contusio cordis are leading causes.

Science.gov (United States)

Krexi, Lydia; Sheppard, Mary N

2018-01-01

Background In forensic practice, a blow to the chest can lead to sudden cardiac death (SCD). Commotio cordis and contusio cordis are leading causes. Methods From a database of 4678 patients who suffered from SCD, we found three patients with commotio cordis and two patients with contusio cordis. All the patients were examined macroscopically and microscopically and had negative toxicology screen. Results The three patients who died due to commotio cordis were young males (16, 23 and 38 years old). The circumstances of death were: a blow to the chest by a football, by a friend during a party and during an assault. The hearts were completely normal at autopsy. The two patients who had contusio cordis were older males (42 and 63 years old). Both patients died during traffic accidents. At autopsy, one had significant contusion over the left ventricle, and the second had contusion over the right ventricle. Conclusion This study indicates that a blow to the chest is very important to document in the circumstances of death, and a detailed history is vital. It raises the left ventricular intra-cavitary pressure, leading to commotio cordis with immediate death with a normal heart. Blunt chest trauma can cause direct myocardial lesions, with acute changes leading to contusio cordis.

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. © 2010 American Academy of Forensic Sciences.

Blow-up of the quantum potential for a free particle in one dimension

International Nuclear Information System (INIS)

Devillanova, G.; Maddalena, F.; Florio, G.

2013-01-01

We derive a non-linear differential equation that must be satisfied by the quantum potential, in the context of the Madelung equations, in one dimension for a particular class of wave functions. In this case, we exhibit explicit conditions leading to the blow-up of the quantum potential of a free particle at the boundary of the compact support of the probability density.

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.

Preparation of Fish Skin Gelatin-Based Nanofibers Incorporating Cinnamaldehyde by Solution Blow Spinning

Science.gov (United States)

Liu, Fei; Avena-Bustillos, Roberto J.; Bridges, David F.; Takeoka, Gary R.; Wu, Vivian C. H.; Chiou, Bor-Sen; McHugh, Tara H.; Zhong, Fang

2018-01-01

Cinnamaldehyde, a natural preservative that can non-specifically deactivate foodborne pathogens, was successfully incorporated into fish skin gelatin (FSG) solutions and blow spun into uniform nanofibers. The effects of cinnamaldehyde ratios (5–30%, w/w FSG) on physicochemical properties of fiber-forming emulsions (FFEs) and their nanofibers were investigated. Higher ratios resulted in higher values in particle size and viscosity of FFEs, as well as higher values in diameter of nanofibers. Loss of cinnamaldehyde was observed during solution blow spinning (SBS) process and cinnamaldehyde was mainly located on the surface of resultant nanofibers. Nanofibers all showed antibacterial activity by direct diffusion and vapor release against Escherichia coli O157:H7, Salmonella typhimurium, and Listeria monocytogenes. Inhibition zones increased as cinnamaldehyde ratio increased. Nanofibers showed larger inhibition effects than films prepared by casting method when S. typhimurium was exposed to the released cinnamaldehyde vapor, although films had higher remaining cinnamaldehyde than nanofibers after preparation. Lower temperature was favorable for cinnamaldehyde retention, and nanofibers added with 10% cinnamaldehyde ratio showed the highest retention over eight-weeks of storage. Results suggest that FSG nanofibers can be prepared by SBS as carriers for antimicrobials. PMID:29470390

Preparation of Fish Skin Gelatin-Based Nanofibers Incorporating Cinnamaldehyde by Solution Blow Spinning.

Science.gov (United States)

Liu, Fei; Türker Saricaoglu, Furkan; Avena-Bustillos, Roberto J; Bridges, David F; Takeoka, Gary R; Wu, Vivian C H; Chiou, Bor-Sen; Wood, Delilah F; McHugh, Tara H; Zhong, Fang

2018-02-22

Cinnamaldehyde, a natural preservative that can non-specifically deactivate foodborne pathogens, was successfully incorporated into fish skin gelatin (FSG) solutions and blow spun into uniform nanofibers. The effects of cinnamaldehyde ratios (5-30%, w / w FSG) on physicochemical properties of fiber-forming emulsions (FFEs) and their nanofibers were investigated. Higher ratios resulted in higher values in particle size and viscosity of FFEs, as well as higher values in diameter of nanofibers. Loss of cinnamaldehyde was observed during solution blow spinning (SBS) process and cinnamaldehyde was mainly located on the surface of resultant nanofibers. Nanofibers all showed antibacterial activity by direct diffusion and vapor release against Escherichia coli O157:H7 , Salmonella typhimurium , and Listeria monocytogenes . Inhibition zones increased as cinnamaldehyde ratio increased. Nanofibers showed larger inhibition effects than films prepared by casting method when S . typhimurium was exposed to the released cinnamaldehyde vapor, although films had higher remaining cinnamaldehyde than nanofibers after preparation. Lower temperature was favorable for cinnamaldehyde retention, and nanofibers added with 10% cinnamaldehyde ratio showed the highest retention over eight-weeks of storage. Results suggest that FSG nanofibers can be prepared by SBS as carriers for antimicrobials.

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…

Large Eddy simulation of flat plate film cooling at high blowing ratio using open FOAM

Science.gov (United States)

Baagherzadeh Hushmandi, Narmin

2018-06-01

In this work, numerical analysis was performed to predict the behaviour of high Reynolds number turbulent cross-flows used in film cooling applications. The geometry included one row of three discrete coolant holes inclined at 30 degrees to the main flow. In the computational model, the width of the channel was cut into one sixth and symmetry boundaries were applied in the centreline of the coolant hole and along the line of symmetry between two adjacent holes. One of the main factors that affect the performance of film cooling is the blowing ratio of coolant to the main flow. A blowing ratio equal to two was chosen in this study. Analysis showed that the common practice CFD models that employ RANS equations together with turbulence modelling under predict the film cooling effectiveness up to a factor of four. However, LES method showed better agreement of film cooling effectiveness both in tendency and absolute values compared with experimental results.

Dating Pupae of the Blow Fly Calliphora vicina Robineau–Desvoidy 1830 (Diptera: Calliphoridae for Post Mortem Interval—Estimation: Validation of Molecular Age Markers

Directory of Open Access Journals (Sweden)

Barbara K. Zajac

2018-03-01

Full Text Available Determining the age of juvenile blow flies is one of the key tasks of forensic entomology when providing evidence for the minimum post mortem interval. While the age determination of blow fly larvae is well established using morphological parameters, the current study focuses on molecular methods for estimating the age of blow flies during the metamorphosis in the pupal stage, which lasts about half the total juvenile development. It has already been demonstrated in several studies that the intraspecific variance in expression of so far used genes in blow flies is often too high to assign a certain expression level to a distinct age, leading to an inaccurate prediction. To overcome this problem, we previously identified new markers, which show a very sharp age dependent expression course during pupal development of the forensically-important blow fly Calliphora vicina Robineau–Desvoidy 1830 (Diptera: Calliphoridae by analyzing massive parallel sequencing (MPS generated transcriptome data. We initially designed and validated two quantitative polymerase chain reaction (qPCR assays for each of 15 defined pupal ages representing a daily progress during the total pupal development if grown at 17 °C. We also investigated whether the performance of these assays is affected by the ambient temperature, when rearing pupae of C. vicina at three different constant temperatures—namely 17 °C, 20 °C and 25 °C. A temperature dependency of the performance could not be observed, except for one marker. Hence, for each of the defined development landmarks, we can present gene expression profiles of one to two markers defining the mentioned progress in development.

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.

Transport of nonintrinsic impurities injected by laser blow-off method

International Nuclear Information System (INIS)

Bakos, J.S.

1993-09-01

The transport of nonintrinsic impurities injected by laser blow-off method is theoretically described by solving the two-dimensional (radial and toroidal) time dependent equations of diffusion in the edge plasmas of a tokamak. Explicit expressions and evaluation procedures are given for the calculation of the density profile, temperature profile and the diffusion coefficients for the atoms injected and for the ions formed from the injected atoms from the two-dimensional intensity distribution of line radiation of two sorts of atom and ions formed from the atoms measured by a (matrix) CCD camera time resolved. (orig.)

A note on Burgers' equation with time delay: Instability via finite-time blow-up

International Nuclear Information System (INIS)

Jordan, P.M.

2008-01-01

Burgers' equation with time delay is considered. Using the Cole-Hopf transformation, the exact solution of this nonlinear partial differential equation (PDE) is determined in the context of a (seemingly) well-posed initial-boundary value problem (IBVP) involving homogeneous Dirichlet data. The solution obtained, however, is shown to exhibit a delay-induced instability, suffering blow-up in finite-time

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.)

Using gas blow methods to realize accurate volume measurement of radioactivity liquid

International Nuclear Information System (INIS)

Zhang Caiyun

2010-01-01

For liquid which has radioactivity, Realized the accurate volume measurement uncertainty less than 0.2% (k=2) by means of gas blow methods presented in the 'American National Standard-Nuclear Material Control-Volume Calibration Methods(ANSI N15.19-1989)' and the 'ISO Committee Drafts (ISO/TC/85/SC 5N 282 )' and Explored a set methods of Data Processing. In the article, the major problems is to solve data acquisition and function foundation and measurement uncertainty estimate. (authors)

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...

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.

Global existence and blow-up analysis for some degenerate and quasilinear parabolic systems

Directory of Open Access Journals (Sweden)

Haihua Lu

2009-08-01

Full Text Available This paper deals with positive solutions of some degenerate and quasilinear parabolic systems not in divergence form: $u_{1t}=f_1(u_2(\\Delta u_1+a_1u_1,\\cdots, u_{(n-1t}=f_{n-1}(u_n(\\Delta u_{n-1}+a_{n-1} u_{n-1},\\ u_{nt}=f_n(u_1(\\Delta u_n+a_nu_n$ with homogeneous Dirichlet boundary condition and positive initial condition, where $a_i\\ (i=1,2,\\cdots,n$ are positive constants and $f_i\\ (i=1,2,\\cdots,n$ satisfy some conditions. The local existence and uniqueness of classical solution are proved. Moreover, it will be proved that: (i when $\\min\\{a_1,\\cdots,\\ a_n\\}\\leq\\lambda_1$ then there exists global positive classical solution, and all positive classical solutions can not blow up in finite time in the meaning of maximum norm; (ii when $\\min\\{a_1,\\cdots,\\ a_n\\}>\\lambda_1$, and the initial datum $(u_{10},\\cdots,\\ u_{n0}$ satisfies some assumptions, then the positive classical solution is unique and blows up in finite time, where $\\lambda_1$ is the first eigenvalue of $-\\Delta$ in $\\Omega$ with homogeneous Dirichlet boundary condition.

Some problems on non-linear semigroups and the blow-up of integral solutions

International Nuclear Information System (INIS)

Pavel, N.H.

1983-07-01

After some introductory remarks, this highly mathematical document considers a unifying approach in the theory of non-linear semigroups. Then a brief survey is given on blow-up of mild solutions from the semilinear case. Finally, the global behavior of solutions to non-linear evolution equations is addressed; it is found that classical results on the behavior of the maximal solution u as t up-arrow tsub(max) hold also for integral solutions

A binary mixture operated heat pump

International Nuclear Information System (INIS)

Hihara, E.; Saito, T.

1991-01-01

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

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

KAUST Repository

Wang, Qiang; Hu, Longhua; Yoon, Sung Hwan; Lu, Shouxiang; Delichatsios, Michael; Chung, Suk-Ho

2015-01-01

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

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

Development and validation of a new technique for estimating a minimum postmortem interval using adult blow fly (Diptera: Calliphoridae) carcass attendance.

Science.gov (United States)

Mohr, Rachel M; Tomberlin, Jeffery K

2015-07-01

Understanding the onset and duration of adult blow fly activity is critical to accurately estimating the period of insect activity or minimum postmortem interval (minPMI). Few, if any, reliable techniques have been developed and consequently validated for using adult fly activity to determine a minPMI. In this study, adult blow flies (Diptera: Calliphoridae) of Cochliomyia macellaria and Chrysomya rufifacies were collected from swine carcasses in rural central Texas, USA, during summer 2008 and Phormia regina and Calliphora vicina in the winter during 2009 and 2010. Carcass attendance patterns of blow flies were related to species, sex, and oocyte development. Summer-active flies were found to arrive 4-12 h after initial carcass exposure, with both C. macellaria and C. rufifacies arriving within 2 h of one another. Winter-active flies arrived within 48 h of one another. There was significant difference in degree of oocyte development on each of the first 3 days postmortem. These frequency differences allowed a minPMI to be calculated using a binomial analysis. When validated with seven tests using domestic and feral swine and human remains, the technique correctly estimated time of placement in six trials.

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.

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...

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.

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

KAUST Repository

Gerbi, Sté phane; Said-Houari, Belkacem

2011-01-01

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.

A Numerical Study of Anti-Vortex Film Cooling Designs at High Blowing Ratio

Science.gov (United States)

Heidmann, James D.

2008-01-01

A concept for mitigating the adverse effects of jet vorticity and liftoff at high blowing ratios for turbine film cooling flows has been developed and studied at NASA Glenn Research Center. This "anti-vortex" film cooling concept proposes the addition of two branched holes from each primary hole in order to produce a vorticity counter to the detrimental kidney vortices from the main jet. These vortices typically entrain hot freestream gas and are associated with jet separation from the turbine blade surface. The anti-vortex design is unique in that it requires only easily machinable round holes, unlike shaped film cooling holes and other advanced concepts. The anti-vortex film cooling hole concept has been modeled computationally for a single row of 30deg angled holes on a flat surface using the 3D Navier-Stokes solver Glenn-HT. A modification of the anti-vortex concept whereby the branched holes exit adjacent to the main hole has been studied computationally for blowing ratios of 1.0 and 2.0 and at density ratios of 1.0 and 2.0. This modified concept was selected because it has shown the most promise in recent experimental studies. The computational results show that the modified design improves the film cooling effectiveness relative to the round hole baseline and previous anti-vortex cases, in confirmation of the experimental studies.

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.

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

Science.gov (United States)

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

2013-02-01

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

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

Effect of Organic Co-blowing Agents on the Morphology of CO2 Blown Microcellular Polystyrene Foams.

Czech Academy of Sciences Publication Activity Database

Nistor, A.; Topiař, Martin; Sovová, Helena; Kosek, J.

2017-01-01

Roč. 130, DEC 2017 (2017), s. 30-39 ISSN 0896-8446 R&D Projects: GA ČR(CZ) GA14-18938S Institutional support: RVO:67985858 Keywords : polystyrene * closed-cell microcellular foam * co-blowing agent Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 2.991, year: 2016

Longitudinal phase space characterization of the blow-out regime of rf photoinjector operation

OpenAIRE

J. T. Moody; P. Musumeci; M. S. Gutierrez; J. B. Rosenzweig; C. M. Scoby

2009-01-01

Using an experimental scheme based on a vertically deflecting rf deflector and a horizontally dispersing dipole, we characterize the longitudinal phase space of the beam in the blow-out regime at the UCLA Pegasus rf photoinjector. Because of the achievement of unprecedented resolution both in time (50 fs) and energy (1.0 keV), we are able to demonstrate some important properties of the beams created in this regime such as extremely low longitudinal emittance, large temporal energy chirp, and ...

The effect of warm air-blowing on the microtensile bond strength of one-step self-etch adhesives to root canal dentin.

Science.gov (United States)

Taguchi, Keita; Hosaka, Keiichi; Ikeda, Masaomi; Kishikawa, Ryuzo; Foxton, Richard; Nakajima, Masatoshi; Tagami, Junji

2018-02-01

The use of warm air-blowing to evaporate solvents of one-step self-etch adhesive systems (1-SEAs) has been reported to be a useful method. The purpose of this study was to evaluate the effect of warm air-blowing on root canal dentin. Four 1-SEAs (Clearfil Bond SE ONE, Unifil Core EM self-etch bond, Estelink, BeautiDualbond EX) were used. Each 1-SEA was applied to root canal dentin according to the manufacturers' instructions. After the adhesives were applied, solvent was evaporated using either normal air (23±1°C) or warm air (80±1°C) for 20s, and resin composite was placed in the post spaces. The air from the dryer, which could be used in normal- or hot-air-mode, was applied at a distance of 5cm above the root canal cavity in the direction of tooth axis. The temperature of the stream of air from the dryer in the hot-air-mode was 80±1°C, and in the normal mode, 23±1°C. After water storage of the specimens for 24h, the μTBS were evaluated at the coronal and apical regions. The μTBSs were statistically analyzed using three-way ANOVA and Student's t-test with Bonferroni correction (α=0.05). The warm air-blowing significantly increased the μTBS of all 1-SEAs at the apical regions, and also significantly increased the μTBS of two adhesives (Estelink and BeautiDualBond EX) at coronal regions. The μTBS of 1-SEAs to root canal dentin was improved by using warm air-blowing. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

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.

Acute effect of blows to the head due one bout of amateur boxing match on electroencephalography (EEG

Directory of Open Access Journals (Sweden)

keyvan Shabanimoghadam

2011-06-01

Conclusion: It is seems that in boxing sport the nature of blow to the head can lead to brain tissue electrical flow disturbance. This tension that is accompanied with acute mild brain injury and is observed in boxers, electroencephalography, is serious and can lead to next complications and injuries.

40 CFR 372.65 - Chemicals and chemical categories to which this part applies.

Science.gov (United States)

2010-07-01

.../1/87 1-Chloro-1,1-difluoroethane (HCFC-142b) 75-68-3 1/1/94 Chlorodifluoromethane (HCFC-22) 75-45-6...-1,4-Dichloro-2-butene 110-57-6 1/1/95 1,2-Dichloro-1,1-difluoroethane (HCFC-132b) 1649-08-7 1/1/95... tert-Butyl alcohol 1/1/87 75-68-3 1-Chloro-1,1-difluoroethane (HCFC-142b) 1/1/94 75-69-4...

The existence of global solution and ''blow up'' phenomenon for the system of multi-dimensional symmetric regularized wave equations

International Nuclear Information System (INIS)

Guo Boling.

1988-08-01

The existence and uniqueness of the global smooth solution for the initial-boundary value problem of the system of multi-dimensions SRWE are proved. The sufficient conditions of ''blowing up'' of the solution are given. (author). 6 refs

Investigation on thermomechanical properties of poly (l-lactic acid) for the stretch blow moulding process of bioresorbable vascular scaffold

Science.gov (United States)

Wei, Huidong; Menary, Gary

2017-10-01

Stretch blow moulding process has been used for the manufacture of bioresorbable vascular scaffold (BVS) made by poly (l-lactic acid) (PLLA) to improve its mechanical performance. In order to better understand the process, thermomechanical properties of PLLA were investigated by experimental method. Extruded PLLA sheets were biaxial stretched under strain rate of 1s-1, 4s-1 and 16s-1 to simulate the deformation process applicable in the blow moulding process. Both the equal-biaxial stretch and constant-width stretch were conducted by an in-house developed equipment. By differential scanning calorimeter (DSC), thermal analysis for materials before and after stretch were compared to evaluate the microstructural change of PLLA materials in the deformation process. A constitutive model based on glass rubber model was presented to simulate the mechanical behaviour of PLLA above glass transition under biaxial deformation.

"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.

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

Improved Longitudinal Blow-up and Shaving in the Booster

CERN Document Server

Hancock, S

2013-01-01

The low-intensity proton beam for p-Pb collisions in the LHC did not come back in the Booster at the beginning of 2013 anything like it had been set up at the end of 2012. In particular there were unexplained intensity fluctuations of ±100%. Although the root cause of the drift in performance was never established, its investigation revealed long-standing issues in the longitudinal plane which, when corrected, allowed single-bunch beams to be delivered with unprecedented reproducibility and control of both intensity and longitudinal emittance. The new approach was adopted for the ion run and subsequently for MDs at higher intensities, where it made possible a robust control of intensity at constant 6D phase space volume. Post-LS1, it may even provide a platform upon which to build a more exotic controlled longitudinal blow-up to generate higher intensity bunches with a flattened line density.

Blowing up solutions for a biharmonic equation with critical nonlinearity

International Nuclear Information System (INIS)

El Mehdi, K.; Hammami, M.

2004-05-01

In this paper we consider the following biharmonic equation with critical exponent (P ε ):Δ 2 u=Ku (n+4)/(n-4)-ε , u>0 in Ω and u=Δu=0 on ∂Ω, where Ω is a smooth bounded domain in R n , n≥5, ε is a small positive parameter, and K is a smooth positive function in Ω-bar. We construct solutions of (P ε ) which blow up and concentrate at strict local maximum of K either at the boundary or in the interior of Ω. We also construct solutions of (P ε ) concentrating at an interior strict local minimum point of K. Finally, we prove a nonexistence result for the supercritical problem which is in sharp contrast to what happened for (P ε ). (author)

Oviposition preferences of two forensically important blow fly species, Chrysomya megacephala and C. rufifacies (Diptera: Calliphoridae), and implications for postmortem interval estimation.

Science.gov (United States)

Yang, Shih-Tsai; Shiao, Shiuh-Feng

2012-03-01

Necrophagous blow fly species (Diptera: Calliphoridae) are the most important agents for estimating the postmortem interval (PMI) in forensic entomology. Nevertheless, the oviposition preferences of blow flies may cause a bias of PMI estimations because of a delay or acceleration of egg laying. Chrysomya megacephala (F.) and C. rufifacies (Macquart) are two predominant necrophagous blow fly species in Taiwan. Their larvae undergo rather intense competition, and the latter one can prey on the former under natural conditions. To understand the oviposition preferences of these two species, a dual-choice device was used to test the choice of oviposition sites by females. Results showed when pork liver with and without larvae of C. rufifacies was provided, C. megacephala preferred to lay eggs on the liver without larvae. However, C. megacephala showed no preference when pork liver with and without conspecific larvae or larvae of Hemipyrellia ligurriens (Wiedemann) was provided. These results indicate that females of C. megacephala try to avoid laying eggs around larvae of facultatively predaceous species of C. rufifacies. However, C. rufifacies showed significant oviposition preference for pork liver with larvae of C. megacephala or conspecific ones when compared with pork liver with no larvae. These results probably imply that conspecific larvae or larvae of C. megacephala may potentially be alternative food resources for C. rufifacies, so that its females prefer to lay eggs in their presence. When considering the size of the oviposition media, pork livers of a relatively small size were obviously unfavorable to both species. This may be because females need to find sufficient resources to meet the food demands of their larvae. In another experiment, neither blow fly species showed an oviposition preference for pork livers of different stages of decay. In addition, the oviposition preferences of both species to those media with larvae were greatly disturbed in a dark

40 CFR 82.19 - Apportionment of baseline consumption allowances for class II controlled substances.

Science.gov (United States)

2010-07-01

... allowances for class II controlled substances. 82.19 Section 82.19 Protection of Environment ENVIRONMENTAL... Consumption Controls § 82.19 Apportionment of baseline consumption allowances for class II controlled... Ineos Fluor Americas HCFC-22 2,546,305 Kivlan & Company HCFC-22 2,081,018 MDA Manufacturing HCFC-22 2...

Simulative design and process optimization of the two-stage stretch-blow molding process

Energy Technology Data Exchange (ETDEWEB)

Hopmann, Ch.; Rasche, S.; Windeck, C. [Institute of Plastics Processing at RWTH Aachen University (IKV) Pontstraße 49, 52062 Aachen (Germany)

2015-05-22

The total production costs of PET bottles are significantly affected by the costs of raw material. Approximately 70 % of the total costs are spent for the raw material. Therefore, stretch-blow molding industry intends to reduce the total production costs by an optimized material efficiency. However, there is often a trade-off between an optimized material efficiency and required product properties. Due to a multitude of complex boundary conditions, the design process of new stretch-blow molded products is still a challenging task and is often based on empirical knowledge. Application of current CAE-tools supports the design process by reducing development time and costs. This paper describes an approach to determine optimized preform geometry and corresponding process parameters iteratively. The wall thickness distribution and the local stretch ratios of the blown bottle are calculated in a three-dimensional process simulation. Thereby, the wall thickness distribution is correlated with an objective function and preform geometry as well as process parameters are varied by an optimization algorithm. Taking into account the correlation between material usage, process history and resulting product properties, integrative coupled simulation steps, e.g. structural analyses or barrier simulations, are performed. The approach is applied on a 0.5 liter PET bottle of Krones AG, Neutraubling, Germany. The investigations point out that the design process can be supported by applying this simulative optimization approach. In an optimization study the total bottle weight is reduced from 18.5 g to 15.5 g. The validation of the computed results is in progress.

Simulative design and process optimization of the two-stage stretch-blow molding process

International Nuclear Information System (INIS)

Hopmann, Ch.; Rasche, S.; Windeck, C.

2015-01-01

The total production costs of PET bottles are significantly affected by the costs of raw material. Approximately 70 % of the total costs are spent for the raw material. Therefore, stretch-blow molding industry intends to reduce the total production costs by an optimized material efficiency. However, there is often a trade-off between an optimized material efficiency and required product properties. Due to a multitude of complex boundary conditions, the design process of new stretch-blow molded products is still a challenging task and is often based on empirical knowledge. Application of current CAE-tools supports the design process by reducing development time and costs. This paper describes an approach to determine optimized preform geometry and corresponding process parameters iteratively. The wall thickness distribution and the local stretch ratios of the blown bottle are calculated in a three-dimensional process simulation. Thereby, the wall thickness distribution is correlated with an objective function and preform geometry as well as process parameters are varied by an optimization algorithm. Taking into account the correlation between material usage, process history and resulting product properties, integrative coupled simulation steps, e.g. structural analyses or barrier simulations, are performed. The approach is applied on a 0.5 liter PET bottle of Krones AG, Neutraubling, Germany. The investigations point out that the design process can be supported by applying this simulative optimization approach. In an optimization study the total bottle weight is reduced from 18.5 g to 15.5 g. The validation of the computed results is in progress

An Innovative Oil Pollution Containment Method for Ship Wrecks Proposed for Offshore Well Blow-outs

OpenAIRE

ANDRITSOS Fivos; COJINS Hans

2011-01-01

In the aftermath of the PRESTIGE disaster, an innovative system for the prompt intervention on oil pollution sources (primarily ship wrecks) at great depths was conceived at the Joint Research Center of the European Commission. This system, with some re-engineering, could also serve for collecting oil and gas leaking after an offshore well blow-out and could constitute a reference method for prompt intervention on deep water oil pollution sources like ship wrecks and blown-out offshore wells....

Treatment of reactive process wastewater with high-level ammonia by blow-off method

International Nuclear Information System (INIS)

Chen Xiaotong; Quan Ying; Wang Yang; Fu Genna; Liu Bing; Tang Yaping

2012-01-01

The ceramic UO 2 kernels for nuclear fuel elements of high temperature gas cooled reactors were prepared through sol-gel process with uranyl nitrate, which produces process wastewater containing high-level ammonia and uranium. The blow-off method on a bench scale was investigated to remove ammonia from reactive wastewater. Under the optimized operating conditions, the ammonia can be removed by more than 95%, with little reactive uranium distilled. The effects of pH, heating temperature and stripping time were studied. Static tests with ion-exchange resin indicate that ammonia removal treatment increases uranium accumulation in anion exchange resin. (authors)

Enhancement of efficacy of process water monitors in detecting heavy water leak in steam generator blow down lines

International Nuclear Information System (INIS)

Mitra, S.R.; Kohale, S.D.; Parida, B.K.; Gathe, G.D.; Pati, C.K.; Mudgal, B.K.; Niraj; Pawar, S.K.

2006-01-01

The Steam Generator (SG) serves as an interface between primary and secondary cycle in Pressurized Heavy Water Reactor (PHWR). Failure of steam generator tubes result in leaking of active heavy water in the secondary closed loop. In Tarapur Atomic Power Station-3 and 4 (TAPS- 3 and 4), Scintillator detectors are provided to detect on line heavy water leakages in SG and moderator heat exchangers by monitoring Nitrogen-16 ( 16 N) and Oxygen-19 ( 19 O) activities. Efficacy of detection of these activities at designed detector position on SG blow down line in presence of background radiation field is analysed theoretically. The count rate of 19 O and 16 N estimated at the detector position inside Reactor Building (RB) shows that detectors only respond to very high leak rates due to presence of high ambient radiation level even though sensitivity is appreciably good. For detector position in RB in the accessible areas and out side the RE containment, the travel time for the blow down feed water becomes moderately and very long respectively resulting in poor sensitivity. However the results show that wherever background levels is low, the efficacy of leak detection becomes considerably better than the results obtained when detector is placed inside RB. The study was validated during the reactor operation by recording the detector count rates due to prevalent ambient radiation level near to the detectors. Subsequently the detectors were relocated in an area inside RB where relocation was feasible, travel time of the blow down feed water was moderate and the area had an relatively low ambient radiation level. This paper discusses the methodology adopted during the study and results obtained during theoretical estimation and practical validation. (author)

Methane oxidation and degradation of organic compounds in landfill soil covers

DEFF Research Database (Denmark)

Scheutz, Charlotte; Kjeldsen, Peter

2002-01-01

High rates of methane oxidation and degradation of the lowed halogenated methanes (TCM and DCM) and HCFCs (HCFC-21 and HCFC-22) were found in an investigation of the oxidation of methane and halogenated organic compunds (HOCs) in landfill gas affected soil. The degradation followed zero-order kin......High rates of methane oxidation and degradation of the lowed halogenated methanes (TCM and DCM) and HCFCs (HCFC-21 and HCFC-22) were found in an investigation of the oxidation of methane and halogenated organic compunds (HOCs) in landfill gas affected soil. The degradation followed zero...

Quantifying pteridines in the heads of blow flies (Diptera: Calliphoridae): Application for forensic entomology.

Science.gov (United States)

Cammack, J A; Reiskind, M H; Guisewite, L M; Denning, S S; Watson, D W

2017-11-01

In forensic cases involving entomological evidence, establishing the postcolonization interval (post-CI) is a critical component of the investigation. Traditional methods of estimating the post-CI rely on estimating the age of immature blow flies (Diptera: Calliphoridae) collected from remains. However, in cases of delayed discovery (e.g., when remains are located indoors), these insects may have completed their development and be present in the environment as adults. Adult fly collections are often ignored in cases of advanced decomposition because of a presumed little relevance to the investigation; herein we present information on how these insects can be of value. In this study we applied an age-grading technique to estimate the age of adults of Chrysomya megacephala (Fabricius), Cochliomyia macellaria (Fabricius), and Phormia regina (Meigen), based on the temperature-dependent accumulation of pteridines in the compound eyes, when reared at temperatures ranging from 5 to 35°C. Age could be estimated for all species*sex*rearing temperature combinations (mean r 2 ±SE: 0.90±0.01) for all but P. regina reared at 5.4°C. These models can be used to increase the precision of post-CI estimates for remains found indoors, and the high r 2 values of 22 of the 24 regression equations indicates that this is a valid method for estimating the age of adult blow flies at temperatures ≥15°C. Copyright © 2017 Elsevier B.V. All rights reserved.

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.

A paradigm for operant conditioning in blow flies (Phormia terrae novae Robineau-Desvoidy, 1830).

Science.gov (United States)

Sokolowski, Michel B C; Disma, Gérald; 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 decreases. Control procedures revealed that rate of responding is not a simple overall result of feeding or of aging. The flies entered into the hole only if the response was required to obtain the food.

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. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

International Nuclear Information System (INIS)

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

2006-01-01

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

Parameters of the Two-Phase Sand-Air Stream in the Blowing Process

Directory of Open Access Journals (Sweden)

J. Danko

2012-12-01

Full Text Available Theoretical problems concerning the determination of work parameters of the two-phase sand-air stream in the cores making process byblowing methods as well as experimental methods of determination of the main and auxiliary parameters of this process decisive on thecores quality assessed by the value and distribution of their apparent density are presented in the paper. In addition the results of visualisations of the core-box filling with the sand-air stream, from the blowing chamber, obtained by the process filming by means of the quick-action camera are presented in the paper and compared with the results of simulation calculations with the application of the ProCast software.

Experimental performance of R432A to replace R22 in residential air-conditioners and heat pumps

International Nuclear Information System (INIS)

Park, Ki-Jung; Shim, Yun-Bo; Jung, Dongsoo

2009-01-01

In this study, thermodynamic performance of R432A and HCFC22 is measured in a heat pump bench tester under both air-conditioning and heat pumping conditions. R432A has no ozone depletion potential and very low greenhouse warming potential of less than 5. R432A also offers a similar vapor pressure to HCFC22 for 'drop-in' replacement. Test results showed that the coefficient of performance and capacity of R432A are 8.5-8.7% and 1.9-6.4% higher than those of HCFC22 for both conditions. The compressor discharge temperature of R432A is 14.1-17.3 deg. C lower than that of HCFC22 while the amount of charge for R432A is 50% lower than that of HCFC22 due to its low density. Overall, R432A is a good long term 'drop-in' environmentally friendly alternative to replace HCFC22 in residential air-conditioners and heat pumps due to its excellent thermodynamic and environmental properties

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.

Nanofiber production of poly (vinylidene fluoride) / hexaferrite, obtained by Blow Spinning Technique; Producao de nanofibras de poli (fluoreto de vinilideno)/hexaferrita, obtidos pela tecnica Blow Spinning

Energy Technology Data Exchange (ETDEWEB)

Dias, G.C.; Zadorosny, L.; Malmonge, J.A.; Malmonge, L.F., E-mail: gabriel.fct@gmail.com [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Ilha Solteira, SP (Brazil)

2014-07-01

In this study, fibrous films of poly (vinylidene fluoride) - PVDF with barium hexaferrite particles were obtained by Solution Blow Spinning technique. In such technique, the polymer solution is injected through an inner nozzle which experiences the action of an accelerated flux of gas that drags and stretches the jet solution forming the nanofibers. The films were obtained from solutions of PVDF/DMF (30% w/v), which was incorporated into barium hexaferrite particles in proportions of 1, 3 and 5% (w / w). The results of the micrographs revealed the formation of a fibrous film with good dispersion of the particles. Xray analyzes showed the predominance of the β crystalline phase of PVDF. The increase of the amount of particles induces the appearance of a characteristic peak of PVDF. EDX measurements confirmed the presence of particles in the films. (author)

The Toshiba Blow-Down MHD Test Facility, and Experiments on Non-Equilibrium Ionization

International Nuclear Information System (INIS)

Yamamoto, Y.; Ogiwara, H.; Shioda, S.; Miyata, M.; Goto, M.; Kasahara, E.

1968-01-01

The Toshiba blow-down MHD test facility, which was constructed in 1966 and has operated successfully in many experiments, is described. Operating conditions achieved are: the working gas is helium seeded with potassium, the maximum mass flow being 80 g/sec, the maximum seed fraction 0.1%; the gas static lies between temperature 1200 and 1700°K, the static pressure between 2.0 ∼ 1.2 atm, the velocity of gas in the generator channel between 1000 and 200 m/sec; the duration is up to 30 sec; the magnetic field is 2.7 T; the impurity of working gas is below 150 ppm. (author)

OCONUS Compliance Assessment Protocols Air Force Supplement

Science.gov (United States)

2009-09-01

32-4 Chlormephos 24934-91-6 Chlormequat chloride 999-81-5 1-Chloro-1,1- difluoroethane (HCFC 142(b)) 75-68-3 1-Chloro-2,3- epoxypropane 106-89-8... difluoroethane (HCFC-132b) 1649-08-7 2,2-Dichloro-1,1,1-tri-fluoroethane (HCFC 123) 306-83-2 Dichloran 99-30-9 p-Dichlorobenzene 106-46-7 1,4

Thermodynamic comparision of R744/R600a and R744/R600 used in mid-high temperature heat pump system

Directory of Open Access Journals (Sweden)

Fan Xiao-Wei

2014-01-01

Full Text Available The mid-high temperature heat pump provides hot water at a relatively high temperature using some industrial waste heat as its source. Now, the main refrigerants in this application are CFC114, HCFC123, and HCFC142b, etc., which are scheduled to be phased out due to their high ozone depletion potential and global warmth potential. Some studies have been conducted to find an eco-friendly alternative. In this paper, the natural non-azeotropic mixtures R744/R600a and R744/R600 are analyzed as alternatives. The performance of the heat pump system using new mixture is discussed and compared with those with CFC114, HCFC123, and HCFC142b. Under the given operating conditions, the maximum heating COP should occur at the mass fractions of 18/82 for R744/R600a and 10/90 for R744/R600. Both of their COP are higher than those with the refrigerants of CFC114, HCFC123, and HCFC142b. The COP and volumetric heating capacity of the system with R744/R600a are superior to those with R744/R600.

Simulation on Effect of Preform Diameter in Injection Stretch Blow Molding

Science.gov (United States)

Tan, Z. Q.; Rosli, Nurrina; Oktaviandri, Muchamad

2018-03-01

Polyethylene terephthalate (PET) is the most common material of resin for manufacturing plastic bottle by injection stretch blow molding due to its excellent properties. As various issues of health and environmental hazards due to the PET use have risen, PET bottle manufacture may be improved by minimizing the wall thickness to reduce the PET use. One of the critical qualifications of the manufacturing process which lead to the wall thickness distribution is the initial preform diameter. In this project, we used the ANSYS Polyflow with aim to evaluate the wall thickness distribution of PET bottle for different diameter of initial preform. As a result, only 4 mm preform diameter presented wall thickness below than 1 mm. On the other hand, at least 6 mm preform diameter can permit the wall thickness 1.3 mm i.e. at the shoulder area.

A revised geological range (Late Pliocene) for foraminifer taxon Bolliella adamsi Banner et Blow, 1959

Science.gov (United States)

Reddy, A. Nallapa; Nagendra, R.

2017-12-01

The foraminifer taxon Bolliella adamsi Banner et Blow, 1959 is found to co-occur with index planktic foraminifer taxa of the Late Pliocene (Zone N21) in a core of 2.60 m at 1300 m water depth off Tuticorin, Bay of Bengal. This taxon has been previously known as a Holocene taxon of the Indo-Pacific province. This study significantly revises the known stratigraphic range of B. adamsi from the Late Pliocene (uppermost part of Zone N21) to the Holocene in the Bay of Bengal area.

Longitudinal phase space characterization of the blow-out regime of rf photoinjector operation

Directory of Open Access Journals (Sweden)

J. T. Moody

2009-07-01

Full Text Available Using an experimental scheme based on a vertically deflecting rf deflector and a horizontally dispersing dipole, we characterize the longitudinal phase space of the beam in the blow-out regime at the UCLA Pegasus rf photoinjector. Because of the achievement of unprecedented resolution both in time (50 fs and energy (1.0 keV, we are able to demonstrate some important properties of the beams created in this regime such as extremely low longitudinal emittance, large temporal energy chirp, and the degrading effects of the cathode image charge in the longitudinal phase space which eventually leads to poorer beam quality. All of these results have been found in good agreement with simulations.

Improvement of blow down model for LEAP code

International Nuclear Information System (INIS)

Itooka, Satoshi; Fujimata, Kazuhiro

2003-03-01

In Japan Nuclear Cycle Development Institute, the improvement of analysis method for overheating tube rapture was studied for the accident of sodium-water reactions in the steam generator of a fast breeder reactor and the evaluation of heat transfer condition in the tube were carried out based on study of critical heat flux (CHF) and post-CHF heat transfer equation in Light Water Reactors. In this study, the improvement of blow down model for the LEAP code was carried out taking into consideration the above-mentioned evaluation of heat transfer condition. Improvements of the LEAP code were following items. Calculations and verification were performed with the improved LEAP code in order to confirm the code functions. The addition of critical heat flux (CHF) by the formula of Katto and the formula of Tong. The addition of post-CHF heat transfer equation by the formula of Condie-BengstonIV and the formula of Groeneveld 5.9. The physical properties of the water and steam are expanded to the critical conditions of the water. The expansion of the total number of section and the improvement of the input form. The addition of the function to control the valve setting by the PID control model. (author)

Global existence and blow-up phenomena for two-component Degasperis-Procesi system and two-component b-family system

OpenAIRE

Liu, Jingjing; Yin, Zhaoyang

2014-01-01

This paper is concerned with global existence and blow-up phenomena for two-component Degasperis-Procesi system and two-component b-family system. The strategy relies on our observation on new conservative quantities of these systems. Several new global existence results and a new blowup result of strong solutions to the two-component Degasperis- Procesi system and the two-component b-family system are presented by using these new conservative quantities.

Mutations in THAP11 cause an inborn error of cobalamin metabolism and developmental abnormalities.

Science.gov (United States)

Quintana, Anita M; Yu, Hung-Chun; Brebner, Alison; Pupavac, Mihaela; Geiger, Elizabeth A; Watson, Abigail; Castro, Victoria L; Cheung, Warren; Chen, Shu-Huang; Watkins, David; Pastinen, Tomi; Skovby, Flemming; Appel, Bruce; Rosenblatt, David S; Shaikh, Tamim H

2017-08-01

CblX (MIM309541) is an X-linked recessive disorder characterized by defects in cobalamin (vitamin B12) metabolism and other developmental defects. Mutations in HCFC1, a transcriptional co-regulator which interacts with multiple transcription factors, have been associated with cblX. HCFC1 regulates cobalamin metabolism via the regulation of MMACHC expression through its interaction with THAP11, a THAP domain-containing transcription factor. The HCFC1/THAP11 complex potentially regulates genes involved in diverse cellular functions including cell cycle, proliferation, and transcription. Thus, it is likely that mutation of THAP11 also results in biochemical and other phenotypes similar to those observed in patients with cblX. We report a patient who presented with clinical and biochemical phenotypic features that overlap cblX, but who does not have any mutations in either MMACHC or HCFC1. We sequenced THAP11 by Sanger sequencing and discovered a potentially pathogenic, homozygous variant, c.240C > G (p.Phe80Leu). Functional analysis in the developing zebrafish embryo demonstrated that both THAP11 and HCFC1 regulate the proliferation and differentiation of neural precursors, suggesting important roles in normal brain development. The loss of THAP11 in zebrafish embryos results in craniofacial abnormalities including the complete loss of Meckel's cartilage, the ceratohyal, and all of the ceratobranchial cartilages. These data are consistent with our previous work that demonstrated a role for HCFC1 in vertebrate craniofacial development. High throughput RNA-sequencing analysis reveals several overlapping gene targets of HCFC1 and THAP11. Thus, both HCFC1 and THAP11 play important roles in the regulation of cobalamin metabolism as well as other pathways involved in early vertebrate development. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Steam condensation behavior of high pressure water's blow down directly into water in containment under LOCA

International Nuclear Information System (INIS)

Kusunoki, Tsuyoshi; Ishida, Toshihisa; Yoritsune, Tsutomu; Kasahara, Y.

1995-01-01

JAERI has been conducting a design study of an advanced type Marine Reactor X (MRX) for merchant ships. By employing 'Integral type PWR', In-vessel type control rod drive systems', 'Water filled containment system' and 'Decay heat removal system by natural convection', MRX achieved a compact, light weight and highly safe plant. Experiments on steam condensation behavior of high pressure water's blow down into water have been conducted in order to investigate a major safety issue related to the design decision of 'Water filled containment system'. (author)

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....... 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...... in the experimental cheeses. Anticlostridial nonstarter Lactobacillus strains have potential as protective adjunct cultures against blowing defects in cheese....

Numerical modeling of plasma plume evolution against ambient background gas in laser blow off experiments

International Nuclear Information System (INIS)

Patel, Bhavesh G.; Das, Amita; Kaw, Predhiman; Singh, Rajesh; Kumar, Ajai

2012-01-01

Two dimensional numerical modelling based on simplified hydrodynamic evolution for an expanding plasma plume (created by laser blow off) against an ambient background gas has been carried out. A comparison with experimental observations shows that these simulations capture most features of the plasma plume expansion. The plume location and other gross features are reproduced as per the experimental observation in quantitative detail. The plume shape evolution and its dependence on the ambient background gas are in good qualitative agreement with the experiment. This suggests that a simplified hydrodynamic expansion model is adequate for the description of plasma plume expansion.

Morphological comparison between Chrysomya rufifacies (Macquart) and Chrysomya villeneuvi Patton (Diptera: Calliphoridae) puparia, forensically important blow flies.

Science.gov (United States)

Sukontason, Kabkaew L; Narongchai, Paitoon; Kanchai, Chaturong; Vichairat, Karnda; Piangjai, Somsak; Boonsriwong, Worachote; Bunchu, Nophawan; Sripakdee, Duanghatai; Chaiwong, Tarinee; Kuntalue, Budsabong; Siriwattanarungsee, Sirisuda; Sukontason, Kom

2006-12-20

In Thailand, the hairy maggots of the blow flies, Chrysomya rufifacies (Macquart) and Chrysomya villeneuvi Patton, are of forensic importance. Both flies are closely related species, not only in the morphological appearance of their larvae and puparia, but also on the aggressive feeding habit of the former. In our continuing studies of forensically important flies, identification of immature ones needs particular attention. In this study, we reported the morphological comparison between the puparia of these two blow fly species using scanning electron microscopy (SEM). Observation revealed that the cuticular sculpture of tubercles along the dorsal and lateral segments had markedly different features: with C. rufifacies having many sharp spines assembling only at the tip, while of C. villeneuvi bore stout spines throughout the tubercle. A larger number of globules at the bubble membrane on the dorsolateral border of the fifth segment was found in C. villeneuvi (average 225) than in C. rufifacies (average 35), and more papillae was observed on the anterior spiracle in C. villeneuvi (13-15) than in C. rufifacies (9-12). However, the morphology of distinct net-like patches of the integument and structure of the posterior spiracle of both species were almost identical. Morphological comparison in this study permitted identification of the puparia of both fly species, particularly in areas where they co-exist.

Expanding the Adoption on Private Lands : Blowing-and-Drifting Snow Control Treatments and the Cost Effectiveness of Permanent versus Non-Permanent Treatment Options

Science.gov (United States)

2017-11-01

Previous research that estimated the costs and benefits of snow-fences for MnDOT in terms of a reduction in the costs of mitigating blowing-and-drifting snow problem areas (MN/RC 2012-03) demonstrated the ability of snow-fences to significantly lower...

Melting of corrosion–resisting steels using air in bath agitation at the end of oxygen blowing

International Nuclear Information System (INIS)

Gizatulin, R A; Valuev, D V; Valueva, A V; Yedesheva, Ch V

2014-01-01

A number of metallurgical plants employ ladle stirring with argon at the end of oxygen blowing during the melting process of corrosion–resisting steels [1, 2]. At the same time, the scarcity and relatively high cost of argon, its low pressure in a shop air pipeline restrain most plants from using argon for corrosion–resisting steel production. Compressed air was used instead of argon to intensify the process of decarbonizing when chromium–nickel stainless steels were made with a 40–ton electric arc furnace at the Kuznetsk Metallurgical Plant

A critical blow-up exponent in a chemotaxis system with nonlinear signal production

Science.gov (United States)

Winkler, Michael

2018-05-01

This paper is concerned with radially symmetric solutions of the Keller–Segel system with nonlinear signal production, as given by in the ball for and R  >  0, where f is a suitably regular function generalizing the prototype determined by the choice , , with . The main results assert that if in this setting the number κ satisfies then for any prescribed mass level m  >  0, there exist initial data u 0 with , for which the solution of the corresponding Neumann initial-boundary value problem blows up in finite time. The condition in () is essentially optimal and is indicated by a complementary result according to which in the case , for widely arbitrary initial data, a global bounded classical solution can always be found.

Electron density profile determination by means of laser blow-off injected neutral beam

International Nuclear Information System (INIS)

Kocsis, G.; Bakos, J.S.; Ignacz, P.N.; Kardon, B.; Koltai, L.; Veres, G.

1992-01-01

This paper is devoted to the experimental and theoretical studies of the determination of the electron density profiles by means of laser blow-off neutrals. For the determination of the density profile the time and spatial distributions of the spectral line radiation intensity of the injected neutrals are used. The method is compared to other previously proposed methods and the advantages and disadvantages of the different methods are discussed. The result of the comparison is that our method gives the most reliable result with the highest temporal resolution for the density profile of the edge plasma. The only disadvantage is the need of careful calibration of the sensitivity of the spatial channels. The advantage is the ability of the method as a standard diagnostic. (orig.)

Use of the theory of recognition of patterns in developing methane metering equipment for blow-out-dangerous mines. [Instrument recognizes rate of change of methane concentration and, if dangerous, shuts off electrical equipment

Energy Technology Data Exchange (ETDEWEB)

Medvedev, V N

1978-01-01

In the most general form, the existing methane-metering equipment which issues command signals when the maximum permissible value of methane concentration has been reached can be viewed as a recognition system. The algorithm for operation on the principle of evaluating the degree of blow-out danger of the ore atmosphere stipulates the recognition of two situations: 1) ''not dangerous ''(methane concentration below maximum permissible value); 2) ''dangerous'' (disorders in technological process; methane concentration above maximum permissible value). This approach for constructing means for gas protection is optimal only for mines working beds which are not dangerous for sudden blow-outs. However, if we ''train'' the apparatus to recognize what was the reason for increase in methane concentration, ways are afforded for solving the problem of creating an effective methane-metering equipment for mines with sudden blow-outs. Gas-dynamic processes with sudden blow-outs can be distinguished from standard technological, in particular, according to the rate in increase in methane concentration. On this basis, functional plan is proposed for constructing the automatic gas protection for explosiondangerous mines which includes a primary measurement of methane concentration, block of concentration control, block of process recognition, block of command signals, block of information delay, block of measuring the rate of methane concentration, threshold device for the rate of increase in concentration.

Nanofiber production of poly (vinylidene fluoride) / hexaferrite, obtained by Blow Spinning Technique

International Nuclear Information System (INIS)

Dias, G.C.; Zadorosny, L.; Malmonge, J.A.; Malmonge, L.F.

2014-01-01

In this study, fibrous films of poly (vinylidene fluoride) - PVDF with barium hexaferrite particles were obtained by Solution Blow Spinning technique. In such technique, the polymer solution is injected through an inner nozzle which experiences the action of an accelerated flux of gas that drags and stretches the jet solution forming the nanofibers. The films were obtained from solutions of PVDF/DMF (30% w/v), which was incorporated into barium hexaferrite particles in proportions of 1, 3 and 5% (w / w). The results of the micrographs revealed the formation of a fibrous film with good dispersion of the particles. Xray analyzes showed the predominance of the β crystalline phase of PVDF. The increase of the amount of particles induces the appearance of a characteristic peak of PVDF. EDX measurements confirmed the presence of particles in the films. (author)

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...

French studies on blow-down accident in light water reactors

International Nuclear Information System (INIS)

Pelce, J.

1977-01-01

The effects on fuel elements and containment buildings resulting from a rapid blow-down accident and the effectiveness of proposed emergency systems are currently being evaluated in France, using the so-called first generation computer codes. Some of these were developed by the constructing organization Framatome for the design of actual power plants; others were developed by the Nuclear Safety Division to back-up related safety studies. These codes are considered to be inadequate and for several years a large effort has been made jointly by EDF and safety authorities, and with the technical assistance of CEA, to make a significant improvement in the methods of assessment. Framatome also participates in this work to some extent. A more physical method is proposed. In particular, selected models are supported by a quite comprehensive experimental programme which is mainly analytical in nature, as follows: (1) Basic analysis, using experiments which are planned or in progress, such as CANON, MOBY-DICK, SUPER MOBY-DICK, REBECA (critical flow at the break and between sub-compartments of the containment building), ECOTRA (condensation on inner walls), TAPIOCA (phase separation at small cracks), EPIS (water and steam mixing during emergency injection), EDGAR (fuel cladding behavior). (2) More intricate or semi-integral analysis such as OMEGA and ERSEC (tests on in-core heat transfer during blow-down and rewetting), both of which are in progress, in-pile PHEBUS loop due to start operating in 1977 (fuel behavior during the accident), pump tests (EVA, POMPE). Future methods of assessing the reactor itself will include the physical models thus perfected: A first code, (CLYSTERE) has been written and can be used. Although it has not been validated experimentally, it can already evaluate the effect of some physical phenomena on the development of the accident. Work is being done on reconstructing the general flow chart of this code in order to improve the conditions of use, in

Diagnosis of blow-out fracture of the orbital floor using a computed tomography

International Nuclear Information System (INIS)

Ishikawa, Yoshimi; Aoki, Shinjiroh; Ono, Shigeru; Fujita, Kiyohide

1986-01-01

Diagnosis of a blow-out fracture of the orbital floor is relatively easy from clinical and roentogen findings but information from these findings are not adequate for the decision for surgical indication. Until recently, computed tomography for the orbital region was generally performed only in axial plane. But the axial plane is parallel to the orbital structure, therefore it is difficult to visualize the orbital floor and inferior rectus muscle. On the other hand, coronal plane is cross-section to the orbital structure, and we can visualize the all orbital soft tissues including extraocular muscles. We examined 3 cases diagnosed as a blow-out fracture of the orbital floor by conventional roentogen films and clinical findings. After axial CT was performed firstly, the coronal CT was scanned with 60 degrees to 70 degrees from OM line, setting the patient in the hanging head position. Case 1 used coronal reformation of the axial CT data. Case 2 and case 3 used direct coronal scanning. By bi-plane CT we could diagnose whether inferior rectus muscle was entrapped or not, and confirm surgical indication. Using of a cadaver, we studied the mechanism for limitation of eye movement. These studies revealed that it is rare that the inferior rectus muscle is entrapped directly by fractured segments at the orbital anterior floor. Because there is a lot of orbital fat-pad between the inferior rectus muscle and the orbital floor, and it may play an important role. The limited mobility of the inferior rectus muscle may occur as a result of increased tension of the fibrous bands that attach to the muscle sheath from the prolapsed fat-pad, and contructure by scar formed secondarily. Diagnosis of the location of a fracture in the orbital floor and cause of the limitation of eye movement must be done as early as possible and from this information we can confirm surgical indication. (J.P.N.)

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.

ANALISIS KELAYAKAN FINANSIAL PROYEK NARROWNECK PRESS AND BLOW UNTUK PROSES PRODUKSIBOTOL MINUMAN BERENERGI DI PT. ABC

Directory of Open Access Journals (Sweden)

Toni MT Munthe

2015-08-01

Full Text Available PT. ABC merupakan salah satu pabrik yang memproduksi botol kemasan kaca. Penelitian ini bertujuan untuk mengetahui layak atau tidaknya rencana investasi pada proyek Narrow Neck Press and Blow secara finansial di PT. ABC pada periode bulan April 2014 hingga bulan Juni 2014. Analisis kelayakan finansial proyek Narrow Neck Press and Blow, menggunakan metode analisis Net Present Value, Internal Rate of Return, Payback Period dan Sensitivity Analysis. Perbedaan antara nilai sekarang dari semua kas masuk dengan nilai sekarang dari semua kas keluar dari suatu proyek atau suatu investasi diperoleh dengan metode NPV, sedangkan untuk mencari tingkat bunga yang menyamakan nilai sekarang dari aliran kas bersih dan investasi diperoleh dengan metode IRR. Metode analisis yang dapat digunakan untuk mengetahui berapa lamakah waktu yang diperlukan untuk menutup dana yang dikeluarkan untuk suatu proyek dapat diperoleh dengan metode Payback Period. Setelah itu, dilakukan pengujian menggunakan sensitivitas analisis untuk mengetahui tingkat sensitivitas untuk tiap-tiap parameter terhadap persentase kenaikan dan penurunan. Dari hasil analisis data diperoleh nilai NPV sebesar Rp. 1.179.728.649.900,06, nilai IRR sebesar 56,36% dan periode pengembalian terletak pada 2 tahun 2 bulan 9 hari. Dengan menggunakan analisis sensitivitas dapat diketahui bahwa proyek ini sangat sensitif terhadap penurunan volume produksi. Berdasarkan hasil perhitungan, titik impas akan dicapai apabila volume produksi 213.403.267 unit per tahun atau 88,92% dari volume produksi awal. Nilai ini menunjukkan bahwa apabila volume produksi pada suatu periode mengalami penurunan lebih dari 11,08% dari volume produksi awal, maka investasi tersebut akan merugikan.

Variability of Blowing Dust Weather Frequency over Semi-Arid Areas of China (Baicheng, Jilin Province and Relationships with Climatic Factors During 1951 - 2006

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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.

Compressed Air System Modifications Improve Efficiency at a Plastics Blow Molding Plant (Southeastern Container Plant): Office of Industrial Technologies (OIT) BestPractices Technical Case Study

Energy Technology Data Exchange (ETDEWEB)

Wogsland, J.

2001-06-18

This case study is one in a series on industrial firms who are implementing energy efficient technologies and system improvements into their manufacturing processes. This case study documents the activities, savings, and lessons learned on the plastics blow molding plant project.

OPTIMASI PROSES MESIN STRETCH BLOW MOULDING PADA BOTOL 600 ML DENGAN METODE RSM (RESPONSE SURFACE METHODOLOGY STUDI KASUS DI PT. UNIPLASTINDO INTERBUANA

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Mochamad Mas'ud

2017-04-01

Full Text Available Pada proses produksi Aqua botol plastik 600 ml menggunakan mesin stretch blow moulding dengan sistem pneumatik, Pembuatan produk dengan menggunakan mesin ini memiliki faktor-faktor yang dapat mempengaruhi kualitas botol yang dihasilkan . Penyimpangan ukuran (pemerataan tebal botol dan kemiringan botol tidak sesuai dengan spesifikasi mengakibatkan botol dibagian pundak putih dan bergelang (shrinkage. Tujuan dari penelitian ini yaitu mengoptimalkan setting parameter mesin stretch blow moulding agar menghasilkan kualitas baik pada produk botol plastik 600 ml. Adapun variable(prediktor yang di pilih yaitu preblow (bar, preform temperature (, dan P1 point (mm, sedangkan respon yang dicari yaitu kemiringan minimal dan tebal maksimal. Metode yang di gunakan dalam penelitian ini yaitu menggunakan Response Surface Metodhology (RSM yang mana dalam perhitungannya menggunakan software minitab 16. Dengan menggunakan Box Behnken Design dan 3 level factorial di hasilkan run 15 percobaan. Berdasarkan hasil kondisi yang optimal parameter yaitu preblow sebesar 6,5 bar, preform temperature sebesar 114 , dan P1 Point sebesar 25 mm. Dengan setting sebesar tersebut akan menghasilkan respon tebal botol sebesar 0,1446 dan kemiringan botol sebesar 0,1875.

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

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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.

Methodology for characterization of corrosive agents of thermal insulating foams; Desenvolvimento de metodologia para caracterizacao de agentes corrosivos de espumas de isolamento termico

Energy Technology Data Exchange (ETDEWEB)

Sousa, Flavio V. Vasques de [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Fundacao Coordenacao de Projetos, Pesquisas e Estudos Tecnologicos - COPPETEC; Mattos, Oscar R.; Mota, Rafael O. da [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Metalurgica e de Materiais; Margarit-Mattos, Isabel C.P. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Escola de Quimica. Dept. de Processos Organicos; Quintela, Joaquim P. [PETROBRAS, Rio de Janeiro, RJ (Brazil); Vieira, Magda M. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

2005-07-01

Warming up oil and derivatives is a required procedure to make their transportation more efficient due to the increase in fluidity. Therefore, the use of thermally insulated pipeline becomes essential. The commonly practice has been the use of pipelines covered with an optional anticorrosive coating, followed by a polyurethane foam layer, as thermal insulator, and a polyethylene top coating for mechanical protection. During the life time of the pipeline, local ruptures of the polyethylene coating frequently occur, allowing the water permeation throughout the thermal insulator. This water may cause foam leaching that would release corrosive agents on the external wall pipe. The objective of the present work was to investigate the effects of the blowing agents, the addition of flame retardant to the foam as well as operating temperatures on the generation of corrosive solutions on the external wall of thermally insulated pipes. In this sense, polyurethane foams expanded with HCFC-141b, CFC-11 and CO{sub 2}, with and without flame retardant, were evaluated at the temperatures of 80 and 120 deg C. (author)

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

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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.

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)

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Yang, Shih-Tsai; Kurahashi, Hiromu; Shiao, Shiuh-Feng

2014-01-01

Abstract 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. PMID:25152681

Local correlations for flap gap oscillatory blowing active flow control technology

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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.

How are soap bubbles blown? Fluid dynamics of soap bubble blowing

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Davidson, John; Lambert, Lori; Sherman, Erica; Wei, Timothy; Ryu, Sangjin

2013-11-01

Soap bubbles are a common interfacial fluid dynamics phenomenon having a long history of delighting not only children and artists but also scientists. In contrast to the dynamics of liquid droplets in gas and gas bubbles in liquid, the dynamics of soap bubbles has not been well documented. This is possibly because studying soap bubbles is more challenging due to there existing two gas-liquid interfaces. Having the thin-film interface seems to alter the characteristics of the bubble/drop creation process since the interface has limiting factors such as thickness. Thus, the main objective of this study is to determine how the thin-film interface differentiates soap bubbles from gas bubbles and liquid drops. To investigate the creation process of soap bubbles, we constructed an experimental model consisting of air jet flow and a soap film, which consistently replicates the conditions that a human produces when blowing soap bubbles, and examined the interaction between the jet and the soap film using the high-speed videography and the particle image velocimetry.

Evaluation of bait traps as a means to predict initial blow fly (Diptera: Calliphoridae) communities associated with decomposing swine remains in New Jersey, USA.

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Weidner, Lauren M; Gemmellaro, M Denise; Tomberlin, Jeffery K; Hamilton, George C

2017-09-01

Information about blow fly (Diptera: Calliphoridae) species distributions can be valuable for criminal investigations, with regards to determining movement of remains from one location to another and time of colonization estimates, making these data extremely useful. Past work has been conducted on initial species community structure across New Jersey, USA using traps baited with beef liver; however, if these same species frequent vertebrate carrion remains unclear. In order to evaluate these data, piglet carcasses were placed out once every two weeks for a year in New Brunswick, New Jersey, USA. The same methods were implemented as those used for traps baited with beef liver, with length of collections being based on ADD values. Seven calliphorid species, Calliphora vicina (Robineau-Desvoidy), Lucilia sericata (Meigen), Lucilia coeruleiviridis (Macquart), Phormia regina (Meigen), Pollenia pediculata Macquart, Pollenia rudis (F.) and Protophormia terraenovae (Robineau-Desvoidy) were collected from the carcasses. During this experiment L. sericata, L. coeruleiviridis and P. regina were the dominant adult blow flies captured, totaling 38.2%, 29.2% and 29.2% respectively of all adults caught. All three species colonized the carcasses as well, although not all were dominant colonizers. C. vicina was recorded ovipositing in December, while the piglet was submerged in approximately 5cm of snow. All species that totaled at least 1% of the total collection (adults captured and larvae reared) were the same across baited traps and carcasses. This study supports the use of beef liver baits for surveying forensically important blow flies and the application of such information to forensic investigations. Copyright © 2017 Elsevier B.V. All rights reserved.

Novel Method of Weighting Cumulative Helmet Impacts Improves Correlation with Brain White Matter Changes After One Football Season of Sub-concussive Head Blows.

Science.gov (United States)

Merchant-Borna, Kian; Asselin, Patrick; Narayan, Darren; Abar, Beau; Jones, Courtney M C; Bazarian, Jeffrey J

2016-12-01

One football season of sub-concussive head blows has been shown to be associated with subclinical white matter (WM) changes on diffusion tensor imaging (DTI). Prior research analyses of helmet-based impact metrics using mean and peak linear and rotational acceleration showed relatively weak correlations to these WM changes; however, these analyses failed to account for the emerging concept that neuronal vulnerability to successive hits is inversely related to the time between hits (TBH). To develop a novel method for quantifying the cumulative effects of sub-concussive head blows during a single season of collegiate football by weighting helmet-based impact measures for time between helmet impacts. We further aim to compare correlations to changes in DTI after one season of collegiate football using weighted cumulative helmet-based impact measures to correlations using non-weighted cumulative helmet-based impact measures and non-cumulative measures. We performed a secondary analysis of DTI and helmet impact data collected on ten Division III collegiate football players during the 2011 season. All subjects underwent diffusion MR imaging before the start of the football season and within 1 week of the end of the football season. Helmet impacts were recorded at each practice and game using helmet-mounted accelerometers, which computed five helmet-based impact measures for each hit: linear acceleration (LA), rotational acceleration (RA), Gadd Severity Index (GSI), Head Injury Criterion (HIC 15 ), and Head Impact Technology severity profile (HITsp). All helmet-based impact measures were analyzed using five methods of summary: peak and mean (non-cumulative measures), season sum-totals (cumulative unweighted measures), and season sum-totals weighted for time between hits (TBH), the interval of time from hit to post-season DTI assessment (TUA), and both TBH and TUA combined. Summarized helmet-based impact measures were correlated to statistically significant changes in

Starch/poly (butylene adipate-co-terephthalate/montmorillonite films produced by blow extrusion

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Rodrigo A. L. Santos

2014-07-01

Full Text Available This study aims to prepare biodegradable films from cassava starch, poly (butylene adipate-co-terephthalate (PBAT, and montmorillonite (MMT using blow-extrusion process and analyze the effects of different types and concentrations of MMT on the microstructure, physicochemical, and mechanical properties of the resulting films. The films were produced by blending 30% of PBAT with glycerol (17.5%, starch (49.0-52.5%, and four different types of montmorillonite (Cloisite® Na+, 10A, 15A, and 30B at two different concentrations (1.75% and 3.5%. All the films prepared in this study showed an increase in the basal spacing of MMT layers. In particular, the films with 10A and 30B showed the highest increase in intercalation basal spacing, suggesting the formation of intercalated composites. The addition of nanoclays decreased the elongation of films. The addition of Cloisite® 10A resulted in films with the lowest WVP values and the highest stability to water adsorption under different RH conditions.

The effect of starvation on the larval behavior of two forensically important species of blow flies (Diptera: Calliphoridae).

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Singh, Devinder; Bala, Madhu

2009-12-15

The postfeeding larval stage in blow flies is generally an irreversible condition when the fully grown third instar larvae stop feeding and give no response towards food. The larvae of most species then disperse away from their feeding medium and pupariate. There are several cases reported about the use of postfeeding larvae as forensic evidence. It is a matter of common observation that the postfeeding stage can be reached earlier than the expected time if food becomes unavailable. However, no information is available on whether postfeeding stage induced by scarcity of food is also irreversible. Similarly, the minimum period of development required by the larvae of different blow flies species to enable their survival as postfeeding larvae and pupariation in the absence of food is unknown. It was observed during the present studies that the larvae of two Chrysomya species must feed for at least 35 h at 28 degrees C in order to be capable of reaching the postfeeding stage and subsequent pupariation. Duration of the starvation period required to induce postfeeding behavior decreases with increasing age of larvae. In the case of Chrysomya megacephala, 35, 45, 55 and 65 h old larvae attained irreversible postfeeding stage after 30, 20, 12 and 2 h of starvation, respectively. Similarly, larvae of Chrysomya rufifacies that were 35, 45, 55 and 60 h old attained irreversible postfeeding stage after 25, 16, 6 and 2 h of starvation, respectively.

Dependence of energy characteristics of ascending swirling air flow on velocity of vertical blowing

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Volkov, R. E.; Obukhov, A. G.; Kutrunov, V. N.

2018-05-01

In the model of a compressible continuous medium, for the complete Navier-Stokes system of equations, an initial boundary problem is proposed that corresponds to the conducted and planned experiments and describes complex three-dimensional flows of a viscous compressible heat-conducting gas in ascending swirling flows that are initiated by a vertical cold blowing. Using parallelization methods, three-dimensional nonstationary flows of a polytropic viscous compressible heat-conducting gas are constructed numerically in different scaled ascending swirling flows under the condition when gravity and Coriolis forces act. With the help of explicit difference schemes and the proposed initial boundary conditions, approximate solutions of the complete system of Navier-Stokes equations are constructed as well as the velocity and energy characteristics of three-dimensional nonstationary gas flows in ascending swirling flows are determined.

Energy and global warming impacts of CFC alternative technologies for foam building insulations

International Nuclear Information System (INIS)

Fischer, S.K.; Fairchild, P.D.; Hughes, P.J.

1992-01-01

Chlorofluorocarbons (CFCS) have been used as blowing agents in foam insulation, as the working fluids in cooling and refrigeration equipment, and as solvents in general and precision cleaning applications since their introduction in the 1930s. The number of applications and volumes of CFCs used grew at a tremendous pace during the 1960s and 1970s, but in the mid-1980s it was confirmed that these extremely useful chemicals contribute to the destruction of stratospheric zone and that they are the primary cause of the CFCs have also been found to be second only to carbon dioxide as a factor causing increased greenhouse warming. These chemicals are being phased out of use rapidly to protect the ozone layer and it is very important that the replacements for CFCs do not result in a net increase in global warming by introducing less efficient processes that lead to higher energy use and increased carbon dioxide emissions. A study was conducted to identify those alternative chemicals and technologies that could replace CFCs in energy related applications before the year 2000, and to assess the total potential impact of those alternatives on global warming. The analysis for this project included an estimate of the direct effects from the release of blowing agents, refrigerants, and solvents into the atmosphere and the indirect effects of carbon dioxide emissions resulting from energy use for commercial and residential building insulation, household and commercial refrigeration, building and automobile air conditioning, and general metal and electronics solvent cleaning. This paper focuses on those aspects of the study relevant to building insulation. In general the hydrofluorocarbon (HFC) and hydrochlorofluorocarbon alternatives for CFCs lead to large and sometimes dramatic reductions in total equivalent warming impact, lifetime equivalent C0 2 emissions (TEWI). Most of the reductions result from decreased direct effects without significant changes in energy use

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

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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.

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

Cool-weather activity of the forensically important hairy maggot blow fly Chrysomya rufifacies (Macquart) (Diptera: Calliphoridae) on carrion in Upstate South Carolina, United States.

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Cammack, Jonathan A; Nelder, Mark P

2010-02-25

The hairy maggot blow fly Chrysomya rufifacies (Macquart) (Diptera: Calliphoridae) has expanded its range in the United States since its introduction into Texas (ca. 1980) and has been collected in 15 states. We investigated the bionomics of immature and adult C. rufifacies collected from carcasses of a raccoon Procyon lotor (Linnaeus) and white-tailed deer Odocoileus virginianus Zimmerman in Upstate South Carolina during November 2007, and used these insects to estimate the minimum period of insect activity. Puparia of C. rufifacies were collected from deer carrion; 28% were parasitized by Nasonia vitripennis (Walker) (Hymenoptera: Pteromalidae). The mean daily ambient temperature during this study was 11.4+/-1.02 degrees C, representing the lowest recorded mean temperature for adult activity of C. rufifacies; adults of C. rufifacies were observed flying among the carcasses at 9.0 degrees C. Although C. rufifacies is considered a warm-weather blow fly, researchers should be aware of its activity at suboptimal conditions, behavior that might aid its expansion into more northern areas. 2009 Elsevier Ireland Ltd. All rights reserved.

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.

A study of alternative refrigerants for the refrigeration and air conditioning sector in Mauritius

Science.gov (United States)

Dreepaul, R. K.

2017-11-01

The most frequently used refrigerants in the refrigeration and air conditioning (RAC) sector in Mauritius are currently hydrochlorofluorocarbons (HCFC) and hydrofluorocarbons (HFC). However, because of their strong influence on global warming and the impact of HCFCs on the ozone layer, refrigerants such as ammonia (NH3), carbon dioxide (CO2) and Hydrocarbons (HC), having minimal impact on the environment, are being considered. So far, HCs have only been safely used in domestic refrigeration. Ammonia has been used mainly for industrial refrigeration whereas CO2 is still under study. In this paper, a comparative study of the various feasible alternatives is presented in a survey that was undertaken with major stake holders in the field. The retrofitting possibility of existing equipment was assessed and safety issues associated with each refrigerant were analysed. The major setback of hydrocarbons as a widely accepted refrigerant is its flammability which was considered as a major safety hazard by the majority of respondents in the survey and the main advantages are the improved equipment coefficient of performance (COP) and better TEWI factor. This resulted in a 12 % drop in energy consumption. Despite the excellent thermodynamic properties of ammonia, its use has mainly been confined to industrial refrigeration due to its toxicity. In Mauritius, the performance of ammonia in air conditioning is being evaluated on a pilot basis. The major setback of carbon dioxide as a refrigerant is the high operating pressure which is considered a safety hazard. The high initial investment cost and the lack of qualified maintenance technician is also an issue. The use of CO2 is mainly being considered in the commercial refrigeration sector.

An analytical method for trifluoroacetic Acid in water and air samples using headspace gas chromatographic determination of the methyl ester.

Science.gov (United States)

Zehavi, D; Seiber, J N

1996-10-01

An analytical method has been developed for the determination of trace levels of trifluoroacetic acid (TFA), an atmospheric breakdown product of several of the hydrofluorocarbon (HFC) and hydrochlorofluorocarbon (HCFC) replacements for the chlorofluorocarbon (CFC) refrigerants, in water and air. TFA is derivatized to the volatile methyl trifluoroacetate (MTFA) and determined by automated headspace gas chromatography (HSGC) with electron-capture detection or manual HSGC using GC/MS in the selected ion monitoring (SIM) mode. The method is based on the reaction of an aqueous sample containing TFA with dimethyl sulfate (DMS) in concentrated sulfuric acid in a sealed headspace vial under conditions favoring distribution of MTFA to the vapor phase. Water samples are prepared by evaporative concentration, during which TFA is retained as the anion, followed by extraction with diethyl ether of the acidified sample and then back-extraction of TFA (as the anion) in aqueous bicarbonate solution. The extraction step is required for samples with a relatively high background of other salts and organic materials. Air samples are collected in sodium bicarbonate-glycerin-coated glass denuder tubes and prepared by rinsing the denuder contents with water to form an aqueous sample for derivatization and analysis. Recoveries of TFA from spiked water, with and without evaporative concentration, and from spiked air were quantitative, with estimated detection limits of 10 ng/mL (unconcentrated) and 25 pg/mL (concentrated 250 mL:1 mL) for water and 1 ng/m(3) (72 h at 5 L/min) for air. Several environmental air, fogwater, rainwater, and surface water samples were successfully analyzed; many showed the presence of TFA.

Effects of eucalyptol on house fly (Diptera: Muscidae and blow fly (Diptera: Calliphoridae

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Sukontason Kabkaew L.

2004-01-01

Full Text Available The effects of eucalyptol were evaluated against the house fly, Musca domestica L., and blow fly, Chrysomya megacephala (F.. The bioassay of adults, using topical application, indicated that M. domestica males were more susceptible than females, with the LD50 being 118 and 177 mg/fly, respectively. A higher LD50 of C. megacephala was obtained; 197 mg/fly for males and 221 mg/fly for females. Living flies of both species yielded a shorter life span after being treated with eucalyptol. The bioassay of larvae, using the dipping method on the third instar, showed that M. domestica was more susceptible than C. megacephala, with their LC50 being 101 and 642 mg/ml, respectively. The emergence of adults, which had been treated with eucalyptol in larvae, decreased only in M. domestica. Having the volatile property, fumigation or impregnated paper test of eucalyptol or the efficacy of repellence or attractiveness merits further investigations to enhance bio-insecticidal efficacy.

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.

Analysis on blow-down transient in water ingress accident of high temperature gas-cooled reactor

International Nuclear Information System (INIS)

Wang, Yan; Zheng, Yanhua; Li, Fu; Shi, Lei

2014-01-01

Water ingress into the primary circuit is generally recognized as one of the severe accidents with potential hazard to the modular high temperature gas-cooled reactor, which will cause a positive reactivity introduction with the increase of steam density in reactor core to enhance neutron slowing-down, also the chemical corrosion of graphite fuel elements and the damage of reflector structure material. The increase of the primary pressure may result in the opening of the safety valves, consequently leading the release of radioactive isotopes and flammable water gas. The research on water ingress transient is significant for the verification of inherent safety characteristics of high temperature gas-cooled reactor. The 200 MWe high temperature gas-cooled reactor (HTR-PM), designed by the Institute of Nuclear and New Energy Technology of Tsinghua University, is exampled to be analyzed in this paper. The design basis accident (DBA) scenarios of double-ended guillotine break of single heat-exchange tube (steam generator heat-exchange tube rupture) are simulated by the thermal-hydraulic analysis code, and some key concerns which are relative to the amount of water into the reactor core during the blow-down transient are analyzed in detail. The results show that both of water mass and steam ratio of the fluid spouting from the broken heat-exchange tube are affected by break location, which will increase obviously with the broken location closing to the outlet of the heat-exchange tube. The double-ended guillotine rupture at the outlet of the heat-exchange will result more steam penetrates into the reactor core in the design basis accident of water ingress. The mass of water ingress will also be affected by the draining system. It is concluded that, with reasonable optimization on design to balance safety and economy, the total mass of water ingress into the primary circuit of reactor could be limited effectively to meet the safety requirements, and the pollution of

40 CFR 82.17 - Apportionment of baseline production allowances for class II controlled substances.

Science.gov (United States)

2010-07-01

... allowances for class II controlled substances. 82.17 Section 82.17 Protection of Environment ENVIRONMENTAL... Consumption Controls § 82.17 Apportionment of baseline production allowances for class II controlled... 1,759,681 MDA Manufacturing HCFC-22 2,383,835 Solvay Solexis HCFC-142b 6,541,764 [ 74 FR 66446, Dec...

USB environment measurements based on full-scale static engine ground tests. [Upper Surface Blowing for YC-14

Science.gov (United States)

Sussman, M. B.; Harkonen, D. L.; Reed, J. B.

1976-01-01

Flow turning parameters, static pressures, surface temperatures, surface fluctuating pressures and acceleration levels were measured in the environment of a full-scale upper surface blowing (USB) propulsive-lift test configuration. The test components included a flightworthy CF6-50D engine, nacelle and USB flap assembly utilized in conjunction with ground verification testing of the USAF YC-14 Advanced Medium STOL Transport propulsion system. Results, based on a preliminary analysis of the data, generally show reasonable agreement with predicted levels based on model data. However, additional detailed analysis is required to confirm the preliminary evaluation, to help delineate certain discrepancies with model data and to establish a basis for future flight test comparisons.

Abundance and sources of atmospheric halocarbons in the Eastern Mediterranean

Science.gov (United States)

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

2018-03-01

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

75 FR 34017 - Protection of Stratospheric Ozone: Notice 25 for Significant New Alternatives Policy Program

Science.gov (United States)

2010-06-16

... open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number... substitute listed as unacceptable, except for certain exceptions (e.g., test marketing, research and..., 2010, virgin HCFC-22 and HCFC-142b, and blends containing one or both of these compounds, may only be...

Performance of alternative refrigerants for residential air-conditioning applications

International Nuclear Information System (INIS)

Park, Ki-Jung; Seo, Taebeom; Jung, Dongsoo

2007-01-01

In this study, performances of two pure hydrocarbons and seven mixtures composed of propylene, propane, HFC152a, and dimethylether were measured to substitute for HCFC22 in residential air-conditioners and heat pumps. Thermodynamic cycle analysis was carried out to determine the optimum compositions before testing and actual tests were performed in a breadboard-type laboratory heat pump/air-conditioner at the evaporation and condensation temperatures of 7 and 45 deg. C, respectively. Test results show that the coefficient of performance of these mixtures is up to 5.7% higher than that of HCFC22. While propane showed a 11.5% reduction in capacity, most of the fluids had a similar capacity to that of HCFC22. For these fluids, compressor-discharge temperatures were reduced by 11-17 deg. C. For all fluids tested, the amount of charge was reduced by up to 55% as compared to HCFC22. Overall, these fluids provide good performances with reasonable energy-savings without any environmental problem and thus can be used as long-term alternatives for residential air-conditioning and heat-pumping applications

Reduced fractal model for quantitative analysis of averaged micromotions in mesoscale: Characterization of blow-like signals

International Nuclear Information System (INIS)

Nigmatullin, Raoul R.; Toboev, Vyacheslav A.; Lino, Paolo; Maione, Guido

2015-01-01

Highlights: •A new approach describes fractal-branched systems with long-range fluctuations. •A reduced fractal model is proposed. •The approach is used to characterize blow-like signals. •The approach is tested on data from different fields. -- Abstract: It has been shown that many micromotions in the mesoscale region are averaged in accordance with their self-similar (geometrical/dynamical) structure. This distinctive feature helps to reduce a wide set of different micromotions describing relaxation/exchange processes to an averaged collective motion, expressed mathematically in a rather general form. This reduction opens new perspectives in description of different blow-like signals (BLS) in many complex systems. The main characteristic of these signals is a finite duration also when the generalized reduced function is used for their quantitative fitting. As an example, we describe quantitatively available signals that are generated by bronchial asthmatic people, songs by queen bees, and car engine valves operating in the idling regime. We develop a special treatment procedure based on the eigen-coordinates (ECs) method that allows to justify the generalized reduced fractal model (RFM) for description of BLS that can propagate in different complex systems. The obtained describing function is based on the self-similar properties of the different considered micromotions. This kind of cooperative model is proposed here for the first time. In spite of the fact that the nature of the dynamic processes that take place in fractal structure on a mesoscale level is not well understood, the parameters of the RFM fitting function can be used for construction of calibration curves, affected by various external/random factors. Then, the calculated set of the fitting parameters of these calibration curves can characterize BLS of different complex systems affected by those factors. Though the method to construct and analyze the calibration curves goes beyond the scope

Integral blow moulding for cycle time reduction of CFR-TP aluminium contour joint processing

Science.gov (United States)

Barfuss, Daniel; Würfel, Veit; Grützner, Raik; Gude, Maik; Müller, Roland

2018-05-01

Integral blow moulding (IBM) as a joining technology of carbon fibre reinforced thermoplastic (CFR-TP) hollow profiles with metallic load introduction elements enables significant cycle time reduction by shortening of the process chain. As the composite part is joined to the metallic part during its consolidation process subsequent joining steps are omitted. In combination with a multi-scale structured load introduction element its form closure function enables to pass very high loads and is capable to achieve high degrees of material utilization. This paper first shows the process set-up utilizing thermoplastic tape braided preforms and two-staged press and internal hydro formed load introduction elements. Second focuses on heating technologies and process optimization. Aiming at cycle time reduction convection and induction heating in regard to the resulting product quality is inspected by photo micrographs and computer tomographic scans. Concluding remarks give final recommendations for the process design in regard to the structural design.

Environmental Compliance Assessment Management Program (ECAMP) - U.S. Fish and Wildlife Service (FWS)

Science.gov (United States)

1994-06-01

for wetlands protection. Whistle Blower Hotline, USEPA 800-424-4000 Allows for reporting of fraud,. waste, and abuse in USEPA programs. iv Table 1...x U172 924-16-3 nitroso- 1 -Chloro-1,1 - difluoroethane x 75-68-3 (HCFC-142(b) 1 -Chloro-1,1,2,2-tetrafluoroet- x 354-25-6 hane (HCFC-124a) 1

Theoretical study of heat pump system using CO2/dimethylether as refrigerant

Directory of Open Access Journals (Sweden)

Fan Xiao-Wei

2013-01-01

Full Text Available Nowadays, HCFC22 is widely used in heat pump systems in China, which should be phased out in the future. Thus, eco-friendly mixture CO2/dimethylether is proposed to replace HCFC22. Compared with pure CO2 and pure dimethylether, the mixture can reduce the heat rejection pressure, and suppress the flammability and explosivity of pure dimethylether. According to the Chinese National Standards on heat pump water heater and space heating system, performances of the subcritical heat pump system are discussed and compared with those of the HCFC22 system. It can be concluded that CO2 /dimethylether mixture works efficiently as a refrigerant for heat pumps with a large heat-sink temperature rise. When mass fraction of dimethylether is increased, the heat rejection pressure is reduced. Under the nominal working condition, there is an optimal mixture mass fraction of 28/72 of CO2/dimethylether for water heater application under conventional condensation pressure, 3/97 for space heating application. For water heater application, both the heating coefficient of performance and volumetric heating capacity increase by 17.90% and 2.74%, respectively, compared with those of HCFC22 systems. For space heating application, the heating coefficient of performance increases by 8.44% while volumetric heating capacity decreases by 34.76%, compared with those of HCFC22 systems. As the superheat degree increases, both the heating coefficient of performance and volumetric heating capacity tend to decrease.

Debris transport evaluation during the blow-down phase of a LOCA using computational fluid dynamics

International Nuclear Information System (INIS)

Park, Jong Pil; Jeong, Ji Hwan; Kim, Won Tae; Kim, Man Woong; Park, Ju Yeop

2011-01-01

Highlights: → We conducted CFD simulation on the spreading of the coolant in the containment after a break of the hot leg. It is used to estimate the dispersion of the debris within the containment. → It was assumed that the small and fine debris is transported by the discharge flow so that a fraction of the small and fine debris transport can be estimated based on the amount of water. → The break flow was assumed to be a homogeneous two-phase mixture without phase separation. Isenthalpic expansion of the break flow was used to specify the inlet boundary condition of the break flow. → The fraction of the small and fine debris transported to the upper part is 73%; this value is close to the value calculated using 1D lumped-parameter codes by the USNRC and the KINS, respectively, while 48% more than the value shown in the NEI 04-07. - Abstract: The performance of the emergency recirculation water sump under the influence of debris accumulation following a loss-of-coolant accident (LOCA) has long been of safety concern. Debris generation and transport during a LOCA are significantly influenced by the characteristics of the ejected coolant flow. One-dimensional analyses previously have been attempted to evaluate the debris transport during the blow-down phase but the transport evaluation still has large uncertainties. In this work, a computational fluid dynamics (CFD) analysis was utilized to evaluate small and fine debris transport during the blow-down phase of a pressurized water reactor, OPR1000. The coolant ejected from the ruptured hot-leg was assumed to expand in an isenthalpic process. The transport of small and fine debris was assumed to be dominated by water-borne transport, and the transport fractions for the upper and lower parts of the containment were quantified based on the CFD analysis. It was estimated that 73% of small and fine debris is transported to the upper part of the containment. This value is close to the values estimated by nuclear

Blowing dust and highway safety in the southwestern United States: Characteristics of dust emission "hotspots" and management implications.

Science.gov (United States)

Li, Junran; Kandakji, Tarek; Lee, Jeffrey A; Tatarko, John; Blackwell, John; Gill, Thomas E; Collins, Joe D

2018-04-15

Despite the widespread media attention of chain-reaction traffic incidents and property damage caused by windblown dust in the U.S. and elsewhere in the world, very few studies have provided in-depth analysis on this issue. Remote sensing and field observations reveal that wind erosion in the southwestern U.S. typically occurs in localized source areas, characterized as "hotspots", while most of the landscape is not eroding. In this study, we identified the spatial and temporal distribution patterns of hotspots that may contribute dust blowing onto highways in the southwestern U.S. We further classified the hotspots for the potential of blowing dust production based upon field observations and wind erosion modeling. Results of land use and land cover show that shrubland, grassland, and cropland accounted for 42%, 31%, and 21% of the overall study area, respectively. However, of the 620 total hotspots identified, 164 (26%), 141 (22%), and 234 (38%) are located on shrubland, grassland, and cropland, respectively. Barren land represented 0.9% of the land area but 8% of the dust hotspots. While a majority of these hotspots are located close to highways, we focused on 55 of them, which are located hotspot sites are dominated by sand and silt particles with threshold shear velocities ranging from 0.17-0.78m s -1 , largely depending on the land use of the hotspot sites. Dust emission modeling showed that 13 hotspot sites could produce annual emissions >3.79kg m -2 , yielding highly hazardous dust emissions to ground transportation with visibility hotspots are critical information for highway authorities to make informed and timely management decisions when wind events strike. Copyright © 2017 Elsevier B.V. All rights reserved.

Morphology of immature stages of blow fly, Lucilia sinensis Aubertin (Diptera: Calliphoridae), a potential species of forensic importance.

Science.gov (United States)

Sanit, Sangob; Sukontason, Kom; Kurahashi, Hiromu; Tomberlin, Jeffery K; Wannasan, Anchalee; Kraisittipanit, Rungroj; Sukontason, Kabkaew L

2017-12-01

Lucilia sinensis Aubertin (Diptera: Calliphoridae) is a blow fly species of potential forensic importance since adults are attracted to, and colonize, decomposing vertebrate remains. Blow fly larvae associated with human corpses can be useful evidence in forensic investigations; however, their use is dependent in most cases on proper species identification and availability of developmental data. For identification, morphological information on each life stage is traditionally used. We used scanning electron microscopy (SEM) to examine the ultrastructure of eggs, all instars, and puparia, of L. sinensis. The important characteristics used to differentiate L. sinensis from other species are provided. Distinctive features of the eggs are the slight widening median area extending almost the entire length. The last abdominal segment of the first instar bears elongated outer ventral tubercles along the rim of the last abdominal segment. These tubercles, as well as the well developed median and outer dorsal tubercles, are more prominent in the second and third instars. The surface integument of the tubercles is equipped with circular rows of microtrichia. Pairs of inner dorsal tubercle are absent. Each anterior spiracle is comprised of 9-12 papillae arrange in a single row in the second and third instars. As for the third instar, the dorsal spines between the first and second thoracic segments are delicate, narrow, small, and close together (as row or set). The peristigmatic tufts adjacent to the posterior spiracle of the third instar are moderately branches of short, fine hairs, but minute in puparia. In conclusion, the prominent outer ventral tubercle in all instars and puparia is a new diagnostic feature of L. sinensis and helpful in differentiating it from other Lucilia species that are forensically important. The description of immature L. sinensis in this study will be useful for forensic entomologists in countries where this species exists. Copyright © 2017

BLOW-3A. A theoretical model to describe transient two-phase flow conditions in LMFBR coolant channels

International Nuclear Information System (INIS)

Bottoni, M.; Struwe, D.

1982-12-01

The computer programme BLOW-3A describes sodium boiling phenomena in subassemblies of fast breeder reactors as well as in in-pile or out-of-pile experiments simulating different failure conditions. This report presents a complete documentation of the code from three main viewpoints: the theoretical foundations of the programme are first described with particular reference to the most recent developments; the structure of the programme is then explained in all details necessary for the user to get a rapid acquaintance with it; eventually several examples of the programme validation are discussed thus enabling the reader to acquire a full picture of the possible applications of the code and at the same time to know its validity range. (orig.) [de

Poly(L-lactic acid) and polyurethane nanofibers fabricated by solution blow spinning as potential substrates for cardiac cell culture

Energy Technology Data Exchange (ETDEWEB)

Tomecka, Ewelina, E-mail: etomecka@ch.pw.edu.pl [Department of Microbioanalytics, Institute of Biotechnology, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland); Wojasinski, Michal [Department of Biotechnology and Bioprocess Engineering, Faculty of Chemical and Process Engineering, Warsaw University of Technology, Waryńskiego 1, 00-645 Warsaw (Poland); Jastrzebska, Elzbieta; Chudy, Michal [Department of Microbioanalytics, Institute of Biotechnology, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland); Ciach, Tomasz [Department of Biotechnology and Bioprocess Engineering, Faculty of Chemical and Process Engineering, Warsaw University of Technology, Waryńskiego 1, 00-645 Warsaw (Poland); Brzozka, Zbigniew [Department of Microbioanalytics, Institute of Biotechnology, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland)

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. - Highlights: • Solution blow spinning was used for PLLA and PU nanofibers fabrication. • Three cardiac cell lines differing in age and origin were used for experiments. • The protein modifications of investigated surfaces influenced on cell proliferation. • Nanofibers are better substrates for cardiac cell culture than PS surface. • Nanofibers enable cultivating cardiac cells under conditions similar to in vivo.

Poly(L-lactic acid) and polyurethane nanofibers fabricated by solution blow spinning as potential substrates for cardiac cell culture

International Nuclear Information System (INIS)

Tomecka, Ewelina; Wojasinski, Michal; Jastrzebska, Elzbieta; Chudy, Michal; Ciach, Tomasz; Brzozka, Zbigniew

2017-01-01

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. - Highlights: • Solution blow spinning was used for PLLA and PU nanofibers fabrication. • Three cardiac cell lines differing in age and origin were used for experiments. • The protein modifications of investigated surfaces influenced on cell proliferation. • Nanofibers are better substrates for cardiac cell culture than PS surface. • Nanofibers enable cultivating cardiac cells under conditions similar to in vivo.

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.

Application of advanced coatings to narrow neck press and blow plungers in the glass container industry

Energy Technology Data Exchange (ETDEWEB)

Penlington, R. [Northumbria Univ., Newcastle upon Tyne (United Kingdom). Dept. of Mech. Eng. and Manufacturing Syst.; Sarwar, M. [Northumbria Univ., Newcastle upon Tyne (United Kingdom). Dept. of Mech. Eng. and Manufacturing Syst.; Lewis, D.B. [Sheffield Hallam Univ. (United Kingdom)

1995-11-01

Wear and failure modes exhibited by narrow neck press and blow (NNPB) plungers in the glass container industry have been related to inappropriate material selection. Problems exist with substrate and coating materials which lead to machine down time, process instability and poor product quality. Previous attempts to improve the service life of NNPB plungers have not examined the process operating characteristics and demanding nature of the application. New substrate and coating materials have been utilized and an assessment of their suitability for this application examined. Initial results from plant trials with modified plungers suggest that improvements in operational performance are achievable. This application, and other components of the mould tooling set, may benefit from improvements which may increase tool life and reduce the problems which result from the application of lubricant dopes to glass contact surfaces. (orig.)

The CO{sub 2} hydrate slurry; Le coulis de glace

Energy Technology Data Exchange (ETDEWEB)

Sari, O.; Hu, J.; Eicher, S.; Brun, F. [Institute of Thermal Engineering, University of Applied Sciences of Western Switzerland, Yverdon-les-Bains (Switzerland); Sari, O.; Hu, J. [Clean Cooling Solutions, spin off of University of Applied Sciences of Western Switzerland, Yverdon-les-Bains (Switzerland); Homsy, P. [Nestec Ltd, Vevey (Switzerland); Logel, J.-C. [Axima Refrigeration, Bischheim (France)

2007-12-15

A new, very promising refrigerant was developed, which could be used in industrial processes as well as air conditioners: the CO{sub 2} hydrate slurry. Replacing hydrochlorofluorocarbon HCFC refrigerants has a high priority, due to the strong negative environmental impact of these fluids. New refrigerants have to be environment friendly, non-inflammable, cheap and made of natural materials. CO{sub 2} hydrate slurries and/or a mixture of ice slurry and CO{sub 2} hydrate slurry meet these requirements. The University of Applied Sciences of Western Switzerland in Yverdon, together with industrial partners, investigated the properties of such slurries. The slurries were created using the Coldeco process: the refrigerating fluid is directly injected into the liquid brine. The evaporation of the refrigerating fluid cools the liquid down to its freezing point and homogeneously distributed small crystals appear in the liquid. A test rig was built to measure the physical and chemical properties of the slurries obtained in this way. CO{sub 2} hydrate slurries have a higher energy storage capacitance (500 kJ/kg) than ice slurries (333 kJ/kg). The production of CO{sub 2} hydrate slurries in large quantities in a continuous process was demonstrated. The solid particle concentration was 10%, the pressure amounted to 30 bar and the temperature 2 to 4 {sup o}C. Such slurries can be pumped and circulated in pipe networks. Stainless steel is the appropriate material for such networks. However, the main advantage of the new refrigerant will be, according to the authors, a reduced energy consumption compared to traditional refrigerating cycles: the difference between the temperature required by the user and the refrigerant temperature is reduced, thanks to the use of the latent heat in the new process.

Plutonium, americium, and uranium in blow-sand mounds of safety-shot sites at the Nevada Test Site and the Tonopah Test Range

International Nuclear Information System (INIS)

Essington, E.H.; Gilbert, R.O.; Wireman, D.L.; Brady, D.N.; Fowler, E.B.

1977-01-01

Blow-sand mounds or miniature sand dunes and mounds created by burrowing activities of animals were investigated by the Nevada Applied Ecology Group (NAEG) to determine the influence of mounds on plutonium, americium, and uranium distributions and inventories in areas of the Nevada Test Site and Tonopah Test Range. Those radioactive elements were added to the environment as a result of safety experiments of nuclear devices. Two studies were conducted. The first was to estimate the vertical distribution of americium in the blow-sand mounds and in the desert pavement surrounding the mounds. The second was to estimate the amount or concentration of the radioactive materials accumulated in the mound relative to the desert pavement. Five mound types were identified in which plutonium, americium, and uranium concentrations were measured: grass, shrub, complex, animal, and diffuse. The mount top (that portion above the surrounding land surface datum), the mound bottom (that portion below the mound to a depth of 5 cm below the surrounding land surface datum), and soil from the immediate area surrounding the mound were compared separately to determine if the radioactive elements had concentrated in the mounds. Results of the studies indicate that the mounds exhibit higher concentrations of plutonium, americium, and uranium than the immediate surrounding soil. The type of mound does not appear to have influenced the amount of the radioactive material found in the mound except for the animal mounds where the burrowing activities appear to have obliterated distribution patterns

Comparison of Absorbable Mesh Plate versus Titanium-Dynamic Mesh Plate in Reconstruction of Blow-Out Fracture: An Analysis of Long-Term Outcomes

Directory of Open Access Journals (Sweden)

Woon Il Baek

2014-07-01

Full Text Available Background A blow-out fracture is one of the most common facial injuries in midface trauma. Orbital wall reconstruction is extremely important because it can cause various functional and aesthetic sequelae. Although many materials are available, there are no uniformly accepted guidelines regarding material selection for orbital wall reconstruction. Methods From January 2007 to August 2012, a total of 78 patients with blow-out fractures were analyzed. 36 patients received absorbable mesh plates, and 42 patients received titanium-dynamic mesh plates. Both groups were retrospectively evaluated for therapeutic efficacy and safety according to the incidence of three different complications: enophthalmos, extraocular movement impairment, and diplopia. Results For all groups (inferior wall fracture group, medial wall fractrue group, and combined inferomedial wall fracture group, there were improvements in the incidence of each complication regardless of implant types. Moreover, a significant improvement of enophthalmos occurred for both types of implants in group 1 (inferior wall fracture group. However, we found no statistically significant differences of efficacy or complication rate in every groups between both implant types. Conclusions Both types of implants showed good results without significant differences in long-term follow up, even though we expected the higher recurrent enophthalmos rate in patients with absorbable plate. In conclusion, both types seem to be equally effective and safe for orbital wall reconstruction. In particular, both implant types significantly improve the incidence of enophthalmos in cases of inferior orbital wall fractures.

Study of process parameters on two phase flow agitated by top blowing lance injection into a bath

Energy Technology Data Exchange (ETDEWEB)

Xia Jiliang; Ahokainen, T.; Holappa, L.

1998-12-31

Numerical investigation has been carried out for two phase flow in a bath agitated by top blowing lance injection. Eulerian two phase flow model is used. Lance immersion depth, injection gas flow rate, nozzle diameter, and bubble size have been systematically changed to examine their influence on the flow characteristics in the bath. It is found that there appear three typical flow patterns: one-vortex, two-vortex, and three-vortex type, with changing the injection gas flow rate or/and the nozzle diameter at moderate lance immersion depth. Predicted velocities are in a good agreement with Iguchi et al.`s experimental data and the main findings are also consistent with the measurements and observations of Chatterjee and Hsiao and Lehner. (orig.) 24 refs. Computational Fluid Dynamics Technology Programme

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.

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.

Study polymeric membranes PVDF/TiO2 photocatalytic applications with synthesized by solution blow spinning

International Nuclear Information System (INIS)

Gimenes, T.C.; Pereira, E.A.; Montanhera, M.A.; Paula, F.R. de; Spada, E.R.

2016-01-01

In this study we obtained nanofibers titanium dioxide (TiO2) incorporated into the poly (vinylidene fluoride) - PVDF in different concentrations, using a new technique denominated Solution Blow Spinning. This technique has the merits of simplicity, low cost and high efficiency in the production of nanofibers, compared with the technique of Electrospinning, using pressurized gas instead of high voltage, is not limited to the dielectric constant of the material and provides a processing period of at least 100 times faster. The obtained nanofibers exhibit little account and a very smooth morphology, with diameters ranging from 400 to 700 nm and with presence of crystalline anatase phase. The tests showed photocatalytic degradation of Rhodamine B dye, being more degradation shown by the PVDF nanofibers containing 0,7 g of TiO 2 , approximately 75 % of degraded dye. However nanofibers obtained the PVDF/TiO2 applications of this material are numerous, as filters, conductive nanofibers, photocatalysis and sensors. (author)

Three-dimensional strutted graphene grown by substrate-free sugar blowing for high-power-density supercapacitors

Science.gov (United States)

Wang, Xuebin; Zhang, Yuanjian; Zhi, Chunyi; Wang, Xi; Tang, Daiming; Xu, Yibin; Weng, Qunhong; Jiang, Xiangfen; Mitome, Masanori; Golberg, Dmitri; Bando, Yoshio

2013-12-01

Three-dimensional graphene architectures in the macroworld can in principle maintain all the extraordinary nanoscale properties of individual graphene flakes. However, current 3D graphene products suffer from poor electrical conductivity, low surface area and insufficient mechanical strength/elasticity; the interconnected self-supported reproducible 3D graphenes remain unavailable. Here we report a sugar-blowing approach based on a polymeric predecessor to synthesize a 3D graphene bubble network. The bubble network consists of mono- or few-layered graphitic membranes that are tightly glued, rigidly fixed and spatially scaffolded by micrometre-scale graphitic struts. Such a topological configuration provides intimate structural interconnectivities, freeway for electron/phonon transports, huge accessible surface area, as well as robust mechanical properties. The graphene network thus overcomes the drawbacks of presently available 3D graphene products and opens up a wide horizon for diverse practical usages, for example, high-power high-energy electrochemical capacitors, as highlighted in this work.

Three-dimensional strutted graphene grown by substrate-free sugar blowing for high-power-density supercapacitors

Science.gov (United States)

Wang, Xuebin; Zhang, Yuanjian; Zhi, Chunyi; Wang, Xi; Tang, Daiming; Xu, Yibin; Weng, Qunhong; Jiang, Xiangfen; Mitome, Masanori; Golberg, Dmitri; Bando, Yoshio

2013-01-01

Three-dimensional graphene architectures in the macroworld can in principle maintain all the extraordinary nanoscale properties of individual graphene flakes. However, current 3D graphene products suffer from poor electrical conductivity, low surface area and insufficient mechanical strength/elasticity; the interconnected self-supported reproducible 3D graphenes remain unavailable. Here we report a sugar-blowing approach based on a polymeric predecessor to synthesize a 3D graphene bubble network. The bubble network consists of mono- or few-layered graphitic membranes that are tightly glued, rigidly fixed and spatially scaffolded by micrometre-scale graphitic struts. Such a topological configuration provides intimate structural interconnectivities, freeway for electron/phonon transports, huge accessible surface area, as well as robust mechanical properties. The graphene network thus overcomes the drawbacks of presently available 3D graphene products and opens up a wide horizon for diverse practical usages, for example, high-power high-energy electrochemical capacitors, as highlighted in this work. PMID:24336225

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)

Atmospheric chemistry of hydrofluorocarbons and hydrochlorofluorocarbons

International Nuclear Information System (INIS)

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 2 + RO 2 + NO, and RO 2 + NO 2 + M, together with UV absorption spectra of the halogenated alkyl (R) and halogenated alkyl peroxy radicals (RO 2 ). The products following the self reactions for RO 2 radicals for RO 2 = CF 3 CF 2 O 2 , CF 2 HCF 2 O 2 , CF 3 CH 2 O 2 , CFH 2 CFHO 2 , CF 3 O 2 , and CF 3 C(O)O 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 3 CF 2 O, CHF 2 CF 2 O, CFH 2 CHFO, and CF 3 C(O)O; while CF 3 CH 2 O radicals rect with O 2 to give CF 3 CHO and HO 2 . The reaction between CFH 2 O 2 and HO 2 was shown to give 29±7 % CH 2 FCOOH and 72±11 % HCOF as the carbon containing products. The following CF 3 O reactions were studied: CF 3 O+NO, (5.2±2.7)x10 -11 cm 3 molecule -1 s -1 ; CF 3 O+ 10 13 molecule -1 s -1 ; CF 3 O+H 2 O, 0.2-40x10 -17 cm 3 molecule. Reactions of FCO x , x=1,2,3 and FO x , x=0,1,2, were also studied: k(FC(O)+NO)=(1.0±0.2)x10 -11 cm 3 molecule -1 s -1 , k(FC(O)O 2 +NO)=(2.5±0.8)x10 -11 cm 3 molecule -1 s -1 , k(FC(O)O+NO=(1.3±0.7)x10 -10 cm 3 molecule -1 s -1 , k(FC(O)O+O 3 ) -14 cm 3 molecule - 1 s -1 , k(FO 2 +NO)=(1.45±0 cm 3 molecule -1 s -1 , k(FO 2 +NO 2 )=(1.05±0.15)x10 -13 cm 3 mole k(FO 2 +CO) -16 cm 3 molecule -1 s -1 , k(FO 2 +CH 4 ) - molecule -1 s -1 , k(FO 2 +O 3 )z3.4x10 -16 cm 3 molecule -1 s -1 k(FO+O 3 ) -12 cm 3 molecule -1 s -1 . The results from this together with data available in the literature indicate that HFCs do not destroy stratospheric ozone. (author). 11 tabs.; 23 ills.; 106 refs

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.

Preparation and characterization of coating sodium trisilicate (Na2O.nSiO2) at calcium carbonate (CaCO3) for blowing agent in Mg alloy foam

Science.gov (United States)

Erryani, Aprilia; Lestari, Franciska Pramuji; Annur, Dhyah; Kartika, Ika

2018-05-01

The role of blowing agent in the manufacture of porous metal alloys is very important to produce the desired pore. The thermal stability and speed of foam formation have an effect on the resulting pore structure. In porous metal alloys, uniformity of size and pore deployment are the main determinants of the resulting alloys. The coating process of calcium carbonate (CaCO3) has been done using Sodium trisilicate solution by sol-gel method. Foaming agent was pretreated by coating SiO2 passive layer on the surface of CaCO3. This coating aims to produce a more stable blowing agent so that the foaming process can produce a more uniform pore size. The microstructure of the SiO2 passive was observed using Scanning Electron Microscope (SEM) equipped by Energy Dispersive X-Ray Spectrometer (EDS) mapping. The results showed coating CaCO3 using sodium trisilicate was successfully done creating a passive layer of SiO2 on the surface of CaCO3. By the coating process, the thermal stability of coated CaCO3 increased compared to uncoated CaCO3.

Effect of breathing technique of blowing on the extent of damage to the perineum at the moment of delivery: A randomized clinical trial

Directory of Open Access Journals (Sweden)

Zohre Ahmadi

2017-01-01

Full Text Available Introduction: One of the important tasks in managing labor is the protection of perineum. An important variable affecting this outcome is maternal pushing during the second stage of labor. This study was done to investigate the effect of breathing technique on perineal damage extention in laboring Iranian women. Materials and Methods: This randomized clinical trial was performed on 166 nulliparous pregnant women who had reached full-term pregnancy, had low risk pregnancy, and were candidates for vaginal delivery in two following groups: using breathing techniques (case group and valsalva maneuver (control group. In the control group, pushing was done with holding the breath. In the case group, the women were asked to take 2 deep abdominal breaths at the onset of pain, then take another deep breath, and push 4–5 seconds with the open mouth while controlling exhalation. From the crowning stage onward, the women were directed to control their pushing, and do the blowing technique. Results: According to the results, intact perineum was more observed in the case group (P = 0.002. Posterior tears (Grade 1, 2, and 3 was considerably higher in the control group (P = 0.003. Anterior tears (labias and episiotomy were not significantly different in the two groups. Conclusions: It was concluded that breathing technique of blowing can be a good alternative to Valsalva maneuver in order to reduce perineal damage in laboring women.

Blow-off device for limiting excess pressure in nuclear power plants, especially in boiling water nuclear power plants

International Nuclear Information System (INIS)

Simon, U.; Werner, K.D.; Hoffmann, D.; Pontani, B.

1979-01-01

In a blow-off device for limiting excess pressure in nuclear power plants, at least one condensation tube disposed so that a lower outflow and thereof is immersed in a volume of water, and an upper inflow end of the condensation tube extends out of the volume of water and is connectible to a source of steam that is to be condensed or a steam-air mixture, the outflow end of the condensation tube, for stabilizing the condensation being provided with an assembly of wall parts forming passageways extending in axial direction for subdividing the steam flow and bubbles produced in the volume of water, the passageways of the assembly of wall parts being stepped in axial direction at both axial ends of the assembly of wall parts

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.

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

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

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

Dead-blow hammer design applied to a calibration target mechanism to dampen excessive rebound

Science.gov (United States)

Lim, Brian Y.

1991-01-01

An existing rotary electromagnetic driver was specified to be used to deploy and restow a blackbody calibration target inside of a spacecraft infrared science instrument. However, this target was much more massive than any other previously inherited design applications. The target experienced unacceptable bounce when reaching its stops. Without any design modification, the momentum generated by the driver caused the target to bounce back to its starting position. Initially, elastomeric dampers were used between the driver and the target. However, this design could not prevent the bounce, and it compromised the positional accuracy of the calibration target. A design that successfully met all the requirements incorporated a sealed pocket 85 percent full of 0.75 mm diameter stainless steel balls in the back of the target to provide the effect of a dead-blow hammer. The energy dissipation resulting from the collision of balls in the pocket successfully dampened the excess momentum generated during the target deployment. The disastrous effects of new requirements on a design with a successful flight history, the modifications that were necessary to make the device work, and the tests performed to verify its functionality are described.

Element Distribution in the Oxygen-Rich Side-Blow Bath Smelting of a Low-Grade Bismuth-Lead Concentrate

Science.gov (United States)

Yang, Tianzu; Xiao, Hui; Chen, Lin; Chen, Wei; Liu, Weifeng; Zhang, Duchao

2018-03-01

Oxygen-rich side-blow bath smelting (OSBS) technology offers an efficient method for processing complex bismuth-lead concentrates; however, the element distributions in the process remain unclear. This work determined the distributions of elements, i.e., bismuth, lead, silver, copper, arsenic and antimony, in an industrial-scale OSBS process. The feed, oxidized slag and final products were collected from the respective sampling points and analyzed. For the oxidative smelting process, 65% of bismuth and 76% of silver in the concentrate report to the metal alloy, whereas less lead reports to the metal ( 31%) than the oxidized slag ( 44%). Approximately 50% of copper enters the matte, while more than 63% of arsenic and antimony report to the slag. For the reductive smelting process, less than 4.5% of bismuth, lead, silver and copper in the oxidized slag enter the reduced slag, indicating high recoveries of these metal values.

Abundance and sources of atmospheric halocarbons in the Eastern Mediterranean

Directory of Open Access Journals (Sweden)

F. Schoenenberger

2018-03-01

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

SYMBIOTIC STAR BLOWS BUBBLES INTO SPACE

Science.gov (United States)

2002-01-01

A tempestuous relationship between an unlikely pair of stars may have created an oddly shaped, gaseous nebula that resembles an hourglass nestled within an hourglass. Images taken with Earth-based telescopes have shown the larger, hourglass-shaped nebula. But this picture, taken with NASA's Hubble Space Telescope, reveals a small, bright nebula embedded in the center of the larger one (close-up of nebula in inset). Astronomers have dubbed the entire nebula the 'Southern Crab Nebula' (He2-104), because, from ground-based telescopes, it looks like the body and legs of a crab. The nebula is several light-years long. The possible creators of these shapes cannot be seen at all in this Wide Field and Planetary Camera 2 image. It's a pair of aging stars buried in the glow of the tiny, central nebula. One of them is a red giant, a bloated star that is exhausting its nuclear fuel and is shedding its outer layers in a powerful stellar wind. Its companion is a hot, white dwarf, a stellar zombie of a burned-out star. This odd duo of a red giant and a white dwarf is called a symbiotic system. The red giant is also a Mira Variable, a pulsating red giant, that is far away from its partner. It could take as much as 100 years for the two to orbit around each other. Astronomers speculate that the interaction between these two stars may have sparked episodic outbursts of material, creating the gaseous bubbles that form the nebula. They interact by playing a celestial game of 'catch': as the red giant throws off its bulk in a powerful stellar wind, the white dwarf catches some of it. As a result, an accretion disk of material forms around the white dwarf and spirals onto its hot surface. Gas continues to build up on the surface until it sparks an eruption, blowing material into space. This explosive event may have happened twice in the 'Southern Crab.' Astronomers speculate that the hourglass-shaped nebulae represent two separate outbursts that occurred several thousand years apart

Computational modeling and analysis of heavy water losses in boiler blow down with different positions of BBW-V100 at KANUPP

International Nuclear Information System (INIS)

Maqbool, M. U.

2012-01-01

The term blowdown is referred to the boilers and steam generators. Blowing down water from the steam generators maintains the chemistry of the feedwater and helps prevent scaling or sludge formation. In a nuclear power plant, the primary loop contains some activity in the form of tritium content. In boilers, primary and secondary systems interface and due to the pressure difference there is always a chance of mixing of primary and secondary fluids in event of tube leak. This primary fluid i.e., heavy water in our case can be lost through the blowdown lines after mixing with the feedwater. This thesis is a computational work for the determination of heavy water losses through the blowdown lines. (author)

Fast imaging of the laser-blow-off plume driven shock wave: Dependence on the mass and density of the ambient gas

Energy Technology Data Exchange (ETDEWEB)

George, Sony [ISP, Cochin University of Science and Tech., Cochin 682 022 (India); Singh, R.K., E-mail: rajesh@ipr.res.in [Institute for Plasma Research, Gandhinagar 382 428 (India); Nampoori, V.P.N. [ISP, Cochin University of Science and Tech., Cochin 682 022 (India); Kumar, Ajai [Institute for Plasma Research, Gandhinagar 382 428 (India)

2013-01-17

A systemic investigation of expansion dynamics of plasma plume, produced by laser-blow-off of LiF–C thin film has been done with emphasis on the formation of shock wave and their dependence on the pressure and nature of the ambient gas. The present results demonstrate that highly directional plume produces a strong shock wave in comparison to shock produced by the diverging plume. Shock-velocity, strength and its structure are strongly dependent on ambient environment; maximum shock velocity is observed in helium whereas shock strength is highest in argon environment. The role of chemically reactive processes was not observed in the present case as the plume structure is almost similar in argon and oxygen.

Phase Behavior of Three PBX Elastomers in High-Pressure Chlorodifluoromethane

Science.gov (United States)

Lee, Byung-Chul

2017-10-01

The phase equilibrium behavior data are presented for three kinds of commercial polymer-bonded explosive (PBX) elastomers in chlorodifluoromethane (HCFC22). Levapren^{{registered }} ethylene- co-vinyl acetate (LP-EVA), HyTemp^{{registered }} alkyl acrylate copolymer (HT-ACM), and Viton^{{registered }} fluoroelastomer (VT-FE) were used as the PBX elastomers. For each elastomer + HCFC22 system, the cloud point (CP) and/or bubble point (BP) pressures were measured while varying the temperature and elastomer composition using a phase equilibrium apparatus fitted with a variable-volume view cell. The elastomers examined in this study indicated a lower critical solution temperature phase behavior in the HCFC22 solvent. LP-EVA showed the CPs at temperatures of 323 K to 343 K and at pressures of 3 MPa to 10 MPa, whereas HT-ACM showed the CPs at conditions between 338 K and 363 K and between 4 MPa and 12 MPa. For the LP-EVA and HT-ACM elastomers, the BP behavior was observed at temperatures below about 323 K. For the VT-FE + HCFC22 system, only the CP behavior was observed at temperatures between 323 K and 353 K and at pressures between 6 MPa and 21 MPa. As the elastomer composition increased, the CP pressure increased, reached a maximum value at a specific elastomer composition, and then remained almost constant.

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. © 2015 American Academy of Forensic Sciences.

Prediction of turbulent heat transfer with surface blowing using a non-linear algebraic heat flux model

International Nuclear Information System (INIS)

Bataille, F.; Younis, B.A.; Bellettre, J.; Lallemand, A.

2003-01-01

The paper reports on the prediction of the effects of blowing on the evolution of the thermal and velocity fields in a flat-plate turbulent boundary layer developing over a porous surface. Closure of the time-averaged equations governing the transport of momentum and thermal energy is achieved using a complete Reynolds-stress transport model for the turbulent stresses and a non-linear, algebraic and explicit model for the turbulent heat fluxes. The latter model accounts explicitly for the dependence of the turbulent heat fluxes on the gradients of mean velocity. Results are reported for the case of a heated boundary layer which is first developed into equilibrium over a smooth impervious wall before encountering a porous section through which cooler fluid is continuously injected. Comparisons are made with LDA measurements for an injection rate of 1%. The reduction of the wall shear stress with increase in injection rate is obtained in the calculations, and the computed rates of heat transfer between the hot flow and the wall are found to agree well with the published data

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 (<4%) in BFS packs over a period of 3 months. BA and CBL, however, gave marked losses in LDPE (ca. 70-90%) and PP (ca. 7-25%) packs. Humidity did not have any effect on the sorption loss of any 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.

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.

Elaboration of the Thermodynamic Model of Refining the Converter Bath when Blowing through Three-Tier Oxygen Lance

Directory of Open Access Journals (Sweden)

Anatoliy G. Chernyatevich

2017-10-01

Full Text Available Background. In modern conditions, the BOP-process is the main method of mass use steel product production. At the same time, due to the shortage of high-quality charge materials, resource and energy-saving technologies are particularly relevant. To optimize the BOP-process under modern conditions, it is promising to use improved oxygen lances for top blowing in comparison with known designs. Objective. An important stage in the development of advanced steel production technologies is obtaining information on the thermodynamic model of blowing a converter bath through a three-tier lance with the elaboration of the regularities of oxidation processes within the reaction zone of a 160-ton industrial converter. Methods. The analysis that was carried out has a theoretical nature and is based on the definition of the influence of temperature and pressure on the regularities of oxidation processes within the reaction zones formed when oxygen jets are introduced into the volume of a metal bath, foamed slag-metallic emulsion and waste gases in the working space of the converter. As a thermodynamic parameter, the Gibbs energy was used to estimate the probability of chemical reactions. The pressure effect on the oxidation processes in the converter bath was evaluated in accordance with the Van’t Hoff formula. Results. The thermodynamic features of oxidation processes in the 160-ton BOF bath using a three-tier lance are presented. Primary reaction zone is characterized by the occurrence of oxidation of manganese, silicon, carbon, and iron by gaseous oxygen. In the secondary reaction zone there are chemical reactions of the oxidation of silicon and carbon dissolved in the metal by oxygen, as well as the reduction of iron oxide by carbon. The presence or absence of a slag phase on the melt surface practically does not affect the occurrence probability of chemical transformations within the boundary of primary and secondary reaction zones. The additional

Estimating the age of the adult stages of the blow flies Lucilia sericata and Calliphora vicina (Diptera: Calliphoridae) by means of the cuticular hydrocarbon n-pentacosane.

Science.gov (United States)

Bernhardt, Victoria; Pogoda, Werner; Verhoff, Marcel A; Toennes, Stefan W; Amendt, Jens

2017-09-01

Age estimation of insects like blow flies plays an important role in forensic entomology and can answer questions in regard to time of death. So far the focus is on the immature stages of these insects, but recently the adult fly became a target of interest. It has been established that the profile of specific cuticular hydrocarbons (CHCs) changes in a consistent pattern as adult insects age; thus, their analysis could be a promising tool for the age estimation of adult insects. We investigated the CHC n-pentacosane (nC25) on the legs of the adult blow flies Lucilia sericata and Calliphora vicina with gas chromatography-mass spectrometry. The flies were kept at room temperature (17°C±2°C) and 12:12 L:D from Day 1 to Day 20 post-emergence. For each of five flies per species, the amount of nC25 on all legs was determined daily. The amounts of nC25 on C. vicina increased linearly (R 2 =0.949). No significant difference between sexes could be detected. While L. sericata showed the same linear increase in general, we found significant (page is constructed from these data. Although the influence of various environmental factors, e.g., fluctuating temperatures, still needs to be tested, nC25 seems to be a promising tool for the age estimation of adult flies. Copyright © 2017 The Chartered Society of Forensic Sciences. Published by Elsevier B.V. All rights reserved.

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.

Tracking movement and temperature selection of larvae of two forensically important blow fly species within a "maggot mass".

Science.gov (United States)

Johnson, Aidan P; Wighton, Samuel J; Wallman, James F

2014-11-01

The current study responds to the lack of understanding about the temperatures experienced by individual blow fly larvae within "maggot masses." The temperature selection of both aggregating (in a mass) and nonaggregating larvae was compared and their pattern of movement assessed. Infrared imaging determined the temperatures within a mass and in the vicinity of the constituent individual larvae, whose movements were tracked by dyeing their tissues red. Individual Chrysomya rufifacies larvae selected temperatures above 27°C, significantly higher than the temperature selected by Calliphora vicina larvae (24.5°C). However, this same difference was not seen within a mass, with both species selecting temperatures around 28°C. Larval movement in a mass was nonrandom, indicating that larvae actively select their position in a mass. Furthermore, larvae have a strong tendency to select the hottest part of a mass; therefore, maximum mass temperatures might provide a reliable proxy for the actual temperatures experienced by larvae. © 2014 American Academy of Forensic Sciences.

Optimization of total vaporization solid-phase microextraction (TV-SPME) for the determination of lipid profiles of Phormia regina, a forensically important blow fly species.

Science.gov (United States)

Kranz, William; Carroll, Clinton; Dixon, Darren; Picard, Christine; Goodpaster, John

2017-11-01

A new method has been developed for the determination of fatty acids, sterols, and other lipids which naturally occur within pupae of the blow fly Phormia regina. The method relies upon liquid extraction in non-polar solvent, followed by derivatization using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) w/ 1% trimethylchlorsilane (TMCS) carried out inside the sample vial. The analysis is facilitated by total vaporization solid-phase microextraction (TV-SPME), with gas chromatography-mass spectrometry (GC-MS) serving as the instrumentation for analysis. The TV-SPME delivery technique is approximately a factor of five more sensitive than traditional liquid injection, which may alleviate the need for rotary evaporation, reconstitution, collection of high performance liquid chromatography fractions, and many of the other pre-concentration steps that are commonplace in the current literature. Furthermore, the ability to derivatize the liquid extract in a single easy step while increasing sensitivity represents an improvement over current derivatization methods. The most common lipids identified in fly pupae were various saturated and unsaturated fatty acids ranging from lauric acid (12:0) to arachinoic acid (20:4), as well as cholesterol. The concentrations of myristic acid (14:0), palmitelaidic acid (16:2), and palmitoleic acid (16:1) were the most reliable indicators of the age of the pupae. Graphical abstract Blow fly pupae were extracted prior to emerging as adults. The extracts were analyzed via total vaporization solid-phase microextraction (TV-SPME), revealing a complex mixture of lipids that could be associated with the age of the insect. This information may assist in determining a post-mortum interval (PMI) in a death investigation.

Experimental Study of Flow Boiling Heat Transfer in a Horizontal Microfin Tube

OpenAIRE

Yu, Jian; Koyama, Shigeru; Momoki, Satoru

1995-01-01

An experimental study on flow boiling heat transfer in a horizontal microfin tube is conducted with pure refrigerants HFC134a, HCFC123 and HCFC22 using a water-heated double-tube type test section. The test microfin tube is a copper tube having the following dimensions: 8.37mm mean inside diameter, 0.168mm fin height, 60fin number and 18 degree of helix angle. The local heat transfer coefficients for both counter and parallel flows are measured in a range of heat flux of 1 to 93W/m^2, mass ve...

Ozone-Depleting Substances on the Black Market

Science.gov (United States)

If you are a wholesaler, distributor, or retailer of chlorofluorocarbons (CFCs) or hydrochlorofluorocarbons (HCFCs), you are responsible for ensuring the CFCs/HCFCs you buy are legal. Learn about the penalties of knowingly buying or possessing illegal CFCs

Sustainable management of C&D waste - reducing the source to ozone depletion and global warming

DEFF Research Database (Denmark)

Kjeldsen, Peter

2016-01-01

Large quantities of construction and demolition waste (C&D waste) are produced. Buildings in many countries are thermally insulated by insulation foam containing large amounts of fluorocarbons (chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) or hydrofluoro-carbons (HCFCs), which are ...

How clarinettists articulate: The effect of blowing pressure and tonguing on initial and final transients.

Science.gov (United States)

Li, Weicong; Almeida, André; Smith, John; Wolfe, Joe

2016-02-01

Articulation, including initial and final note transients, is important to tasteful music performance. Clarinettists' tongue-reed contact, the time variation of the blowing pressure P¯mouth, the mouthpiece pressure, the pressure in the instrument bore, and the radiated sound were measured for normal articulation, accents, sforzando, staccato, and for minimal attack, i.e., notes started very softly. All attacks include a phase when the amplitude of the fundamental increases exponentially, with rates r ∼1000 dB s(-1) controlled by varying both the rate of increase in P¯mouth and the timing of tongue release during this increase. Accented and sforzando notes have shorter attacks (r∼1300 dB s(-1)) than normal notes. P¯mouth reaches a higher peak value for accented and sforzando notes, followed by a steady decrease for accented notes or a rapid fall to a lower, nearly steady value for sforzando notes. Staccato notes are usually terminated by tongue contact, producing an exponential decrease in sound pressure with rates similar to those calculated from the bandwidths of the bore resonances: ∼400 dB s(-1). In all other cases, notes are stopped by decreasing P¯mouth. Notes played with different dynamics are qualitatively similar, but louder notes have larger P¯mouth and larger r.

The main elements to consider when designing an arena; Les principaux elements a determiner lors de la conception d'un arena

Energy Technology Data Exchange (ETDEWEB)

Gosselin, M. [Fixair Inc., Quebec, PQ (Canada)

2010-01-01

The refrigeration systems in Quebec's arenas are aging, with most installations dating from the 1970s or 1980s. Most arenas use HCFC R-22 as the coolant, which is a regulated substance in Montreal and should be eliminated by 2020. The price of HCFC R-22 has also increased recently and a shortage is expected. This paper presented the choice of coolants that can be used as a replacement for HCFC R-22. The 3 main options include ammonia R-717; HFC R-404A or R-507A; and carbon dioxide (CO{sub 2}) R-744. This article listed the advantages and disadvantages of each option. It also described the secondary coolant that goes under the ice. The 4 types of secondary coolant include calcium chloride, ethylene glycol, methanol and CO{sub 2}. There are also 2 choices for compressors, notably reciprocal and screw type compressors. The use of heat exchangers in arenas will be instrumental in using waste heat for water heating and space heating purposes. 3 tabs., 3 figs.

21 CFR 701.30 - Ingredient names established for cosmetic ingredient labeling.

Science.gov (United States)

2010-04-01

...-dichloro-1, 1, 2, 2-tetrafluoroethane CClF2CClF2 Chlorofluorocarbon 114. 1-Chloro-1, 1-difluoroethane CH3CClF2 Hydrochlorofluorocarbon 142 B. 1, 1-difluoroethane CH3CHF2 Hydrofluorocarbon 152 A. Ethyl ester...

Further Understanding of Theories and Practice for Low-Cost and High-Efficient Clean Steel Production by Combined Blowing Converter%对复吹转炉低成本、高效化生产洁净钢水理论与实践的再认识

Institute of Scientific and Technical Information of China (English)

曾加庆; 潘贻芳; 王立平; 梁玫; 李树庆

2014-01-01

Based on review of development about the processes of clean steel production at home and abroad, the techni-cal principles and their necessities of low-cost and high-efficient clean steel production by combined blowing converter were analyzed, including low-temperature dephosphorization by combined blowing converter, the coordination of top and bottom blowing, the continuous implementation of the new process, the high-efficient oxygen blowing in decarburization period, and the reutilization method of slag been rich in P2O5, and so on. In order to obtain good implementation effect of the new process, the comprehensive and objective technical key points of the new process must be known well, and also the solid foundation of technical and management would be needed. According to related problems occurred in practice, the improved proposals were put forward.%在回顾总结国内外开展洁净钢水生产技术发展过程的基础上，对复吹转炉低成本、高效化生产洁净钢水工艺的技术原理及相关必要性进行了分析，包括复吹转炉低温脱磷、顶吹与底吹的协同作用、新工艺的连续化实施、脱碳期高效供氧、脱磷炉渣资源化技术途径等。认为要获得好的工艺实施效果，不仅要全面客观地掌握新工艺实施的技术要点，更要具备一定的技术与精细化管理基础。结合新工艺在生产实践中出现的具体问题，提出了改进建议。

Sadhana | Indian Academy of Sciences

Indian Academy of Sciences (India)

Use of organic refrigerants such as Hydrochlorofluorocarbons and Chlorofluorocarbons have been criticized for their adverse impact on the Earth's protective ozone layer and for their significant global warming potential (GWP). CO2 has been receiving great concern as an alternative refrigerant. Cascade refrigeration ...

Considerations for the Estimation of the Risk of Environmental Contamination Due to Blow Out in Offshore Exploratory Drilling Projects

International Nuclear Information System (INIS)

Hurtado, A.; Eguilior, S.; Recreo, F.

2015-01-01

From the consideration of a contemporary society based on the need of a high-level complex technology with a high intrinsic level of uncertainty and its relationship with risk assessment, this analysis, conducted in late 2014, was developed from that that led the Secretary of State for the Environment to the Resolution of 29 May 2014, by which the Environmental Impact Statement of the Exploratory Drilling Project in the hydrocarbons research permits called ''Canarias 1-9// was set out and published in the Spanish Official State Gazette number 196 on 13rd August 2014. The aim of the present study is to analyze the suitability with which the worst case associated probability is identified and defined and its relation to the total risk estimate from a blow out. Its interest stems from the fact that all risk management methodologically rests on two pillars, i.e., on a sound risk analysis and evaluation. This determines the selection of management tools in relation to its level of complexity, the project phase and its potential impacts on the health, safety and environmental contamination dimensions.

Blowing the whistle to protect a patient: a comparison between physiotherapy students and physiotherapists.

Science.gov (United States)

Mansbach, Abraham; Melzer, Itzik; Bachner, Yaacov G

2012-12-01

To answer three questions: Are physiotherapists and physiotherapy students willing to take action to prevent misconduct in order to protect a patient's interests? Are they willing to report the misconduct to authorities within an organisation and/or outside of it? Are they willing to report a colleague's wrongdoing as well as that of a manager? Observational questionnaire study. Two hundred and twenty-seven participants divided into two groups: 126 undergraduate students at the Department of Physical Therapy at Ben Gurion University, and 101 certified physiotherapists working in hospitals and rehabilitation centres in south and central regions of Israel. Participants were presented with two vignettes - one describing a colleague's misconduct and the other describing a manager's misconduct - and asked to make a decision about whistleblowing. Both groups rated their own willingness to take action to change the harmful situations very highly. The physiotherapists perceived a colleague's misconduct as being more serious than the students, and were more willing to intervene internally. The students were more prepared than the physiotherapists to take such action externally. The students perceived the manager's misconduct as being more serious than the physiotherapists, and also reported a greater readiness to intervene externally. Physiotherapists consider acts that are detrimental to a patient to be very serious, and are more willing to take action when the offending individual is a colleague. Students are more willing to blow the whistle externally. This article suggests tools for handling similar situations. Copyright © 2011 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

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.

Considerations for the Estimation of the Risk of Environmental Contamination Due to Blow Out in Offshore Exploratory Drilling Projects; Consideraciones a la Estimación del Riesgo de Contaminación Ambiental por Blow Out en Proyectos de Perforación de Sondeos Exploratorios Offshore

Energy Technology Data Exchange (ETDEWEB)

Hurtado, A.; Eguilior, S.; Recreo, F.

2015-07-01

From the consideration of a contemporary society based on the need of a high-level complex technology with a high intrinsic level of uncertainty and its relationship with risk assessment, this analysis, conducted in late 2014, was developed from that that led the Secretary of State for the Environment to the Resolution of 29 May 2014, by which the Environmental Impact Statement of the Exploratory Drilling Project in the hydrocarbons research permits called ''Canarias 1-9// was set out and published in the Spanish Official State Gazette number 196 on 13rd August 2014. The aim of the present study is to analyze the suitability with which the worst case associated probability is identified and defined and its relation to the total risk estimate from a blow out. Its interest stems from the fact that all risk management methodologically rests on two pillars, i.e., on a sound risk analysis and evaluation. This determines the selection of management tools in relation to its level of complexity, the project phase and its potential impacts on the health, safety and environmental contamination dimensions.

Dynamic study of ocular movement with MR imaging in orbital blow-out fracture

International Nuclear Information System (INIS)

Aibara, Ryuichi; Kawakita, Seiji; Matsumoto, Yasushi; Sadamoto, Masanori; Yumoto, Eiji.

1996-01-01

Operative indications for orbital blow-out fracture (OBF) remain controversial. One of the major sources of this controversy is that an accurate diagnosis of ocular movement disturbances can not be made by conventional procedures such as the Hess screen test, traction test, or CT scan. Disturbances in ocular movement resulting from OBF can occur not only with entrapment of the extraocular muscle but also with intraorbital bleeding, edema, and/or a variety of other unclear factors. To obtain a more accurate diagnosis and to assist in the choice of treatment, ocular movement was examined using orbital 'cine mode' MR imaging. MR images were obtained in multiple phases of vertical and horizontal ocular movements by using the 'fast SE' capabilities of the SIERRA, GE-YMS MR scanner (1.5 Tesla, superconductive). The fixed eye method was applied to two normal volunteers and to patients with 'pure' OBF. Five marks for binocular fixation were affixed to the inner wall of the gantry: one at the primary position and four at secondary positions. While keeping the subject's eye focused on each of these marks for about 30 sec, MR images (head coil) of the axial view and bilateral oblique sagittal view along the optic nerve were carried out. In the normal volunteers, a good demonstration of smooth movement of the eye ball, extraocular muscles, and the optic nerve could be obtained. In the OBF patients, it was clearly observed that the disturbance in ocular movement was caused by poor extension of the external ocular muscles, specifically the inferior rectus muscle in the orbital floor fracture, and the internal rectus muscle in the medial wall fracture. These observations suggested that dynamic orbital imaging with MR would be extremely valuable in the assessment of disturbances of ocular movement in OBF. (author)

Producing, Importing, and Exporting Ozone-Depleting Substances

Science.gov (United States)

Overview page provides links to information on producing, importing, and exporting ozone-depleting substances, including information about the HCFC allowance system, importing, labeling, recordkeeping and reporting.

The CNEN Helium-Caesium Blow-Down MPD Facility and Experiments with a Prototype Duct

Energy Technology Data Exchange (ETDEWEB)

Bertolini, E.; Toschi, R. [CNEN, Frascati (Italy); Lindley, B. C. [C.A. Parsons and Co. Ltd (United Kingdom); Brown, R.; McNab, I. R. [International Research and Development Co. Ltd., Newcastle Upon Tyne (United Kingdom)

1966-11-15

The CNEN blow-down loop has been designed to study a helium-caesium MPD generator with particular regard to non-equilibrium ionization effects. An operating condition of the loop is: gas mass flow 0.2 kg/sec, seed fraction 1 at, wt.%, useful pulse duration 20 sec, stagnation temperature 2000 Degree-Sign K, stagnation pressure 5 atm abs, thermal power 1.6 MW, Mach number 0.6, magnetic field 4 Wb/m2, total impurity level less than 100 ppm. A sufficiently wide range of the stagnation conditions can be obtained with the present arrangement of the loop (temperature up to 2000*K, pressure from slightly sub-atmospheric to 6atmabs, gas mass flow from 50 g/sec to 400 g/sec, seed fraction from 0.1 to 2 at. wt.%. The storage heater is an alumina pebble bed electrically heated with tungsten elements and thermally insulated with zirconia fibre; the thermal capacity at 2000 Degree-Sign K is about 1000 MJ. Pure helium is obtained by evaporation of liquid helium at between 4.5 and 5 Degree-Sign K; liquid caesium is injected into a limited section of the pebble bed to provide a mixture of the two gases uniform in density and temperature. The duct is made of boron nitride (5 cm x 3 cm x 22 cm) with 25 pairs of tantalum electrodes whose geometry (electrode width 3 mm, segmentation pitch 9 mm) should prevent current leakage between adjacent electrodes; the duct walls and transfer can be pre-heated up to 1700 Degree-Sign K. A magnetic field of 4 Wb/m{sup 2} is obtained with a pulsed cryogenic magnet with pulse duration of 6 sec. Two series of experiments have been completed to assess the feasibility of the helium-caesium heating system and the generator duct. Heating system experiments, (a) Compatibility of alumina with tungsten, tantalum and caesium, with thermal cycling at 2000 Degree-Sign K; (b) Purification of zirconia fibre and its behaviour at high temperature, with thermal cycling at 2000 Degree-Sign K; (c) Capability of an alumina pebble bed of evaporating, heating and mixing

Using Acid Number as a Leading Indicator of Refrigeration and Air Conditioning System Performance

Energy Technology Data Exchange (ETDEWEB)

Dennis Cartlidge; Hans Schellhase

2003-07-31

This report summarizes a literature review to assess the acidity characteristics of the older mineral oil and newer polyolester (POE) refrigeration systems as well as to evaluate acid measuring techniques used in other non-aqueous systems which may be applicable for refrigeration systems. Failure in the older chlorofluorocarbon/hydrochlorofluorocarbon (CFC/HCFC) / mineral oil systems was primarily due to thermal degradation of the refrigerant which resulted in the formation of hydrochloric and hydrofluoric acids. These are strong mineral acids, which can, over time, severely corrode the system metals and lead to the formation of copper plating on iron surfaces. The oil lubricants used in the older systems were relatively stable and were not prone to hydrolytic degradation due to the low solubility of water in oil. The refrigerants in the newer hydrofluorocarbon (HFC)/POE systems are much more thermally stable than the older CFC/HCFC refrigerants and mineral acid formation is negligible. However, acidity is produced in the new systems by hydrolytic decomposition of the POE lubricants with water to produce the parent organic acids and alcohols used to prepare the POE. The individual acids can therefore vary but they are generally C5 to C9 carboxylic acids. Organic acids are much weaker and far less corrosive to metals than the mineral acids from the older systems but they can, over long time periods, react with metals to form carboxylic metal salts. The salts tend to accumulate in narrow areas such as capillary tubes, particularly if residual hydrocarbon processing chemicals are present in the system, which can lead to plugging. The rate of acid production from POEs varies on a number of factors including chemical structure, moisture levels, temperature, acid concentration and metals. The hydrolysis rate of reaction can be reduced by using driers to reduce the free water concentration and by using scavenging chemicals which react with the system acids. Total acid

40 CFR 82.62 - Definitions.

Science.gov (United States)

2010-07-01

... Containing or Manufactured With Class II Substances § 82.62 Definitions. For purposes of this subpart... to subpart A. Class II Substance means any substance designated as class II in 40 CFR part 82.... Hydrochlorofluorocarbon means any substance listed as class II in 40 CFR part 82, appendix B to subpart A. Initial...

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

Ommatidia of blow fly, house fly, and flesh fly: implication of their vision efficiency.

Science.gov (United States)

Sukontason, Kabkaew L; Chaiwong, Tarinee; Piangjai, Somsak; Upakut, Sorawit; Moophayak, Kittikhun; Sukontason, Kom

2008-06-01

This work aims to elucidate the number of ommatidia or facets (the outwardly visible units of each ommatidium) for compound eyes in blow flies [Chrysomya megacephala (F.), Chrysomya rufifacies (Macquart), Chrysomya nigripes (Aubertin), Lucilia cuprina (Wiedemann)], house flies (Musca domestica L.), and flesh flies (Liosarcophaga dux Thomson) by manual counts of the corneal spreads. The head of the fly in each species was soaked in 20% potassium hydroxide solution at room temperature for 7 days, and the clear compound eye was dissected into six small parts, each of which was placed onto a slide and flattened using a coverslip. Images of each part were obtained using a microscope connected to a computer. The printed images of each part were magnified, and the total number of ommatidia per eye was manually counted. For males, the mean number of ommatidia was statistically different among all flies examined: L. dux (6,032) > C. rufifacies (5,356) > C. nigripes (4,798) > C. megacephala (4,376) > L. cuprina (3,665) > M. domestica (3,484). Likewise, the mean number of facets in females was statistically different: L. dux (6,086) > C. megacephala (5,641) > C. rufifacies (5,208) > C. nigripes (4,774) > L. cuprina (3,608) > M. domestica (3433). Scanning electron microscopy analysis of adult flies revealed the sexual dimorphism in the compound eye. Male C. megacephala had large ommatidia in the upper two thirds part and small ommatidia in the lower one third part, whereas only small ommatidia were detected in females. Dense postulate appearance was detected in the external surface of the corneal lens of the ommatidia of C. megacephala, C. rufifacies, and C. nigripes, while a mix of dense postulate appearance and variable groove array length was detected in L. cuprina and M. domestica. The probable functions of ommatidia are discussed with reference to other literature.

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.

Creating 3D Hierarchical Carbon Architectures with Micro-, Meso-, and Macropores via a Simple Self-Blowing Strategy for a Flow-through Deionization Capacitor.

Science.gov (United States)

Zhao, Shanshan; Yan, Tingting; Wang, Hui; Zhang, Jianping; Shi, Liyi; Zhang, Dengsong

2016-07-20

In this work, 3D hierarchical carbon architectures (3DHCAs) with micro-, meso-, and macropores were prepared via a simple self-blowing strategy as highly efficient electrodes for a flow-through deionization capacitor (FTDC). The obtained 3DHCAs have a hierarchically porous structure, large accessible specific surface area (2061 m(2) g(-1)), and good wettability. The electrochemical tests show that the 3DHCA electrode has a high specific capacitance and good electric conductivity. The deionization experiments demonstrate that the 3DHCA electrodes possess a high deionization capacity of 17.83 mg g(-1) in a 500 mg L(-1) NaCl solution at 1.2 V. Moreover, the 3DHCA electrodes present a fast deionization rate in 100-500 mg L(-1) NaCl solutions at 0.8-1.4 V. The 3DHCA electrodes also present a good regeneration behavior in the reiterative regeneration test. These above factors render the 3DHCAs a promising FTDC electrode material.

Species composition of forensically important blow flies (Diptera: Calliphoridae) and flesh flies (Diptera: Sarcophagidae) through space and time.

Science.gov (United States)

Fremdt, Heike; Amendt, Jens

2014-03-01

Weekly monitoring of forensically important flight-active blow flies (Diptera: Calliphoridae) and flesh flies (Diptera: Sarcophagidae) was performed using small baited traps. Sampling took place in two rural, one suburban and two urban habitats in and around Frankfurt (Main), Germany, lasting two years and eight months. Highest values for species richness and Chao-Shen entropy estimator for Shannon's index in both families were found at the urban sites, peaking during summer. Space-time interaction was tested and found to be significant, demonstrating the value of a statistical approach recently developed for community surveys in ecology. K-means partitioning and analysis of indicator species gave significant temporal and habitat associations of particular taxa. Calliphora vicina was an indicator species for lower temperatures without being associated with a particular habitat. Lucilia sericata was an indicator for urban sites, whereas Lucilia ampullacea and Lucilia caesar were indicators for rural sites, supplemented by the less frequent species Calliphora vomitoria. Sarcophagidae were observed during a clearly shorter period of year. Sarcophaga subvicina+Sarcophaga variegata was found to be an indicator for urban habitats during summer as well as Sarcophaga albiceps for rural habitats. A significant association of Sarcophaga caerulescens to rural habitats as well as one of Sarcophaga similis to urban habitats was observed. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

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.

Heat and mass transfer prediction of binary refrigerant mixtures condensing in a horizontal microfin tube

Energy Technology Data Exchange (ETDEWEB)

Koyama, Shigeru; Yu, Jian; Ishibashi, Akira

1999-07-01

In the face of the phase-out of HCFC22 for its effect on globe environment, the alternative refrigerant has been paid attention in the refrigeration and heat pump industry. In the present stage, it is found that any pure refrigerant is not a good substitute of HCFC22 for the system in use. The authors have to use binary or ternary refrigerant mixtures as the substitute to meet industrial requirement. But until now, although the heat transfer characteristics of the refrigerant mixtures can be measured in experiments and predicted in some degree, the mass transfer characteristics in condensation process, which is a main part in most systems, can not be clarified by both experimental and theoretical methods. In the present study a non-equilibrium model for condensation of binary refrigerant mixtures inside a horizontal microfin tube is proposed. In this model it is assumed that the phase equilibrium is only established at the vapor-liquid interface, while the bulk vapor and the bulk liquid are in non-equilibrium in the same cross section. The mass transfer characteristic in vapor core is obtained from the analogy between mass and momentum transfer. In the liquid layer, the mass fraction distribution is neglected, but the mass transfer coefficient is treated as infinite that can keep a finite value for the mass transfer rate in liquid phase. From the calculation results compared with the experimental ones for the condensation of HFC134a/HCFC123 and HCFC22/CFC114 mixtures, it is found that the calculated heat flux distribution along the tube axis is in good agreement with that of experiment, and the calculated values of condensing length agree well with the experimental ones. Using the present model, the local mass faction distribution, the diffusion mass transfer rate and the mass transfer characteristics in both vapor and liquid phase are demonstrated. From these results, the effect of mass transfer resistance on condensation heat transfer characteristics for binary

Sequence variation in the cytochrome oxidase subunit I and II genes of two commonly found blow fly species, Chrysomya megacephala (Fabricius) and Chrysomya rufifacies (Macquart) (Diptera: Calliphoridae) in Malaysia.

Science.gov (United States)

Tan, Siew Hwa; Aris, Edah Mohd; Surin, Johari; Omar, Baharudin; Kurahashi, Hiromu; Mohamed, Zulqarnain

2009-08-01

The mitochondiral DNA region encompassing the cytochrome oxidase subunit I (COI) and cytochrome oxidase subunit II (COII) genes of two Malaysian blow fly species, Chrysomya megacephala (Fabricius) and Chrysomya rufifacies (Macquart) were studied. This region, which spans 2303bp and includes the COI, tRNA leucine and partial COII was sequenced from adult fly and larval specimens, and compared. Intraspecific variations were observed at 0.26% for Ch. megacephala and 0.17% for Ch. rufifacies, while sequence divergence between the two species was recorded at a minimum of 141 out of 2303 sites (6.12%). Results obtained in this study are comparable to published data, and thus support the use of DNA sequence to facilitate and complement morphology-based species identification.

A Cross-Wavelet Transform Aided Rule Based Approach for Early Prediction of Lean Blow-out in Swirl-Stabilized Dump Combustor

Directory of Open Access Journals (Sweden)

Debangshu Dey

2015-03-01

Full Text Available Lean or ultralean combustion is one of the popular strategies to achieve very low emission levels. However, it is extremely susceptible to lean blow-out (LBO. The present work explores a Cross-wavelet transform (XWT aided rule based scheme for early prediction of lean blowout. XWT can be considered as an advancement of wavelet analysis which gives correlation between two waveforms in time-frequency space. In the present scheme a swirl-stabilized dump combustor is used as a laboratory-scale model of a generic gas turbine combustor with LPG as fuel. Various time series data of CH chemiluminescence signal are recorded for different flame conditions by varying equivalence ratio, flow rate and level of air-fuel premixing. Some features are extracted from the cross-wavelet spectrum of the recorded waveforms and a reference wave. The extracted features are observed to classify the flame condition into three major classes: near LBO, moderate and healthy. Moreover, a Rough Set based technique is also applied on the extracted features to generate a rule base so that it can be fed to a real time controller or expert system to take necessary control action to prevent LBO. Results show that the proposed methodology performs with an acceptable degree of accuracy.

Consumerism triggers AC explosion

Energy Technology Data Exchange (ETDEWEB)

Lafferty, Richard

1997-05-01

The growth in air conditioning in the United Kingdom in recent years is examined in this article, and split systems, the phasing out of CFC and HCFC refrigerants, global warming, and comfort levels are considered. (UK)

Behaviour of intrinsic carbon and laser blow-off injected nickel in Tore Supra during ergodic divertor activation

International Nuclear Information System (INIS)

Mattioli, M.; De Michelis, C.; Monier-Garbet, P.

1995-01-01

The behaviour of intrinsic carbon (the dominating impurity) and laser blow-off injected nickel has been studied in Tore Supra during ergodic divertor (ED) activation. The carbon content is reduced in the plasma core as a result of the screening effect of the ergodic layer, which is due to increased transport in the layer, to increased recycling flux and to a modified impurity source term. Simulations of the C VI and C V intensity ratios require in the ergodic edge both an increased diffusion and a large (in the 10 16 -10 17 m -3 range) neutral hydrogen isotope density. The nickel burst is not 'screened' and penetrates into the core plasma. The confinement time τ P of the injected elements is always increased when the ED is activated, but there is no modification of the core plasma transport (diffusion coefficients, convection velocities, central reduced transport region extension). To simulate the increased central τ p values, a peripheral transport barrier has to be introduced. Satisfactory nickel brightness simulations can be obtained by modifying the inward convection velocity and/or the diffusion coefficient. If the barrier is taken to be purely diffusive, satisfactory carbon line ratios can be recovered, but the simulated injected impurity confinement time τ p is too short. For a satisfactory nickel brightness simulation it is necessary to add to the barrier some inward convection, pushing also the intrinsic carbon ions inwards, but this hinders correct line ratio evaluations. (author). 31 refs, 14 figs, 1 tab

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.

Flammable refrigerants

NARCIS (Netherlands)

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

1999-01-01

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

Magneto-hydrodynamics of coupled fluid–sheet interface with mass suction and blowing

International Nuclear Information System (INIS)

Ahmad, R.

2016-01-01

There are large number of studies which prescribe the kinematics of the sheet and ignore the sheet's mechanics. However, the current boundary layer analysis investigates the mechanics of both the electrically conducting fluid and a permeable sheet, which makes it distinct from the other studies in the literature. One of the objectives of the current study is to (i) examine the behaviour of magnetic field effect for both the surface and the electrically conducting fluid (ii) investigate the heat and mass transfer between a permeable sheet and the surrounding electrically conducting fluid across the hydro, thermal and mass boundary layers. Self-similar solutions are obtained by considering the RK45 technique. Analytical solution is also found for the stretching sheet case. The skin friction dual solutions are presented for various types of sheet. The influence of pertinent parameters on the dimensionless velocity, shear stress, temperature, mass concentration, heat and mass transfer rates on the fluid–sheet interface is presented graphically as well as numerically. The obtained results are of potential benefit for studying the electrically conducting flow over various soft surfaces such as synthetic plastics, soft silicone sheet and soft synthetic rubber sheet. These surfaces are easily deformed by thermal fluctuations or thermal stresses. - Highlights: • The momentum equation is modelled for both the surrounding MHD fluid and the sheet with the effects of mass suction and blowing. • The current study further investigates the heat and mass transfer characteristics between a permeable sheet and the surrounding electrically conducting fluid across the thermal and mass boundary layers. • Both the approximated and analytical techniques have been included for the purpose of comparison, and the perfect numerical agreements have been established with the previous studies. • Dual solutions for the skin friction coefficients are found for various categories of

Blow-off device for limiting excess pressure in nuclear power plants, especially in boiling-water nuclear power plants

International Nuclear Information System (INIS)

Kuehnel, R.

1979-01-01

In a blow-off device for limiting excess pressure in nuclear power plants, at least one condensation tube disposed so that a lower outlet end thereof is immersed in a volume of water in a condensation chamber having a gas cushion located in a space above the volume of water, and the upper inlet end of the condensation tube extending out of the volume of water and being connectible to a source of steam that is to be condensed or a steam-air mixture, the outlet end of the condensation tube, for smoothing the condensation, being provided with wall parts forming passages extending in axial direction, delimited from one another and terminating in the water volume, the wall parts serving to subdivide steam flow from the source thereof and bubbles produced thereby in the water volume, the wall parts being constructed as a tube attachment and being formed with an opening corresponding to the outlet end of the condensation tube and by means of which the tube attachment is mounted on the outlet end of the condensation tube, a first group of the wall parts in the tube attachment being disposed in alignment with the outlet end of the condensation tube, and a second group of the wall parts surrounding the first group thereof, the passages formed by the second group of the wall parts communicating laterally with the passages formed by the first group of the wall parts, the passages formed by the second group of the wall parts, at least at the upper ends thereof, communicating with the water volume

Lead sulfate nano- and microparticles in the acid plant blow-down generated at the sulfuric acid plant of the El Teniente mine, Chile.

Science.gov (United States)

Barassi, Giancarlo M; Klimsa, Martin; Borrmann, Thomas; Cairns, Mathew J; Kinkel, Joachim; Valenzuela, Fernando

2014-12-01

The acid plant 'blow-down' (also called weak acid) produced at El Teniente mine in Chile was characterized. This liquid waste (tailing) is generated during the cooling and cleaning of the smelter gas prior to the production of sulfuric acid. The weak acid was composed of a liquid and a solid phase (suspended solids). The liquid phase of the sample analyzed in this study mainly contained Cu (562 mg L(-1)), SO4(2-) (32 800 mg L(-1)), Ca (1449 mg L(-1)), Fe (185 mg L(-1)), As (6 mg L(-1)), K (467 mg L(-1)) and Al (113 mg L(-1)). Additionally, the sample had a pH-value and total acidity of 0.45 and 2970 mg L(-1) as CaCO3, respectively. Hence, this waste was classified as extremely acidic and with a high metal content following the Ficklin diagram classification. Elemental analysis using atomic absorption, inductively coupled plasma, X-ray diffraction and electron microscopy showed that the suspended solids were anglesite (PbSO4) nano- and microparticles ranging from 50 nm to 500 nm in diameter.

On the wave amplitude blow-up in the Berk-Breizman model for nonlinear evolution of a plasma wave driven resonantly by fast ions

International Nuclear Information System (INIS)

Zaleśny, Jarosław; Galant, Grzegorz; Berczyński, Paweł; Berczyński, Stefan; Lisak, Mietek

2011-01-01

In this paper the Berk-Breizman (BB) model of plasma wave instability arising on the stability threshold is considered. An interesting although physically unacceptable feature of the model is the explosive behaviour occurring in the regime of small values of the collision frequency parameter. We present an analytical description of the explosive solution, based on a fitting to the numerical solution of the BB equation with the collision parameter equal to zero. We find that the chaotic behaviour taking place for small but non-zero values of the collision parameter is absent in this case; therefore, chaotic behaviour seems to be an independent phenomenon not directly related to the blow-up regime. The time and the velocity dependence of the distribution function are found numerically and plotted to better understand what actually happens in the model. It allows us to obtain a good qualitative understanding of the time evolution of the mode amplitude including the linear growth of the amplitude, reaching its maximum and then decreasing towards the zero value. Nevertheless, we have no satisfactory physical explanation of the amplitude evolution when the amplitude vanishes at some time and then revives but with an opposite phase.

Stratospheric measurements of ozone-depleting substances and greenhouse gases using AirCores

Science.gov (United States)

Laube, Johannes; Leedham Elvidge, Emma; Kaiser, Jan; Sturges, Bill; Heikkinen, Pauli; Laurila, Tuomas; Hatakka, Juha; Kivi, Rigel; Chen, Huilin; Fraser, Paul; van der Veen, Carina; Röckmann, Thomas

2017-04-01

Retrieving air samples from the stratosphere has previously required aircraft or large balloons, both of which are expensive to operate. The novel "AirCore" technique (Karion et al., 2010) enables stratospheric sampling using weather balloons, which is much more cost effective. AirCores are long (up to 200 m) stainless steel tubes which are placed as a payload on a small balloon, can ascend to over 30 km and fill upon descent, collecting a vertical profile of the atmosphere. Retrieved volumes are much smaller though, which presents a challenge for trace gas analysis. To date, only the more abundant trace gases such as carnon dioxide (CO2) and methane (CH4) have been quantified in AirCores. Halogenated trace gases are also important greenhouse gases and many also deplete stratospheric ozone. Their concentrations are however much lower i.e. typically in the part per trillion (ppt) molar range. We here present the first stratospheric measurements of halocarbons in AirCores obtained using UEA's highly sensitive (detection limits of 0.01-0.1 ppt in 10 ml of air) gas chromatography mass spectrometry system. The analysed air originates from a Stratospheric Air Sub-sampler (Mrozek et al., 2016) which collects AirCore segments after the non-destructive CO2 and CH4 analysis. Successfully measured species include CFC-11, CFC-12, CFC-113, CFC-115, H-1211, H-1301, HCFC-22, HCFC-141b, HCFC-142b, HCFC-133a, and sulphur hexafluoride (SF6). We compare the observed mixing ratios and precisions with data obtained from samples collected during various high-altitude aircraft campaigns between 2009 and 2016 as well as with southern hemisphere tropospheric long-term trends. As part of the ERC-funded EXC3ITE (EXploring stratospheric Composition, Chemistry and Circulation with Innovative Techniques) project more than 40 AirCore flights are planned in the next 3 years with an expanded range of up to 30 gases in order to explore seasonal and interannual variability in the stratosphere

Gas Release Behavior of Cu-TiH2 Composite Powder and Its Application as a Blowing Agent to Fabricate Aluminum Foams with Low Porosity and Small Pore Size

Science.gov (United States)

Cheng, Ying; Li, Yanxiang; Chen, Xiang; Liu, Zhiyong; Zhou, Xu; Wang, Ningzhen

2018-03-01

Compared to traditional pore structure with high porosity (≥ 80 pct) and large pore size (≥ 3 mm), aluminum foams with low porosity (60 to 70 pct) and small pore size (≤ 2 mm) possess higher compressive property and formability. In order to achieve the goal of reducing pore size, Cu-TiH2 composite powder prepared by ball milling preoxidized TiH2 with Cu powder was used as a blowing agent. Its gas release behavior was characterized by thermogravimetric analysis and differential scanning calorimetry. The results show that the ball milling treatment can advance the gas release process and slow the gas release rate at the same time. All these changes are favorable to the reduction of porosity and pore size. Such Cu-TiH2 composite powder provides an alternative way to fabricate aluminum foams with low porosity and small pore size.

Gas Release Behavior of Cu-TiH2 Composite Powder and Its Application as a Blowing Agent to Fabricate Aluminum Foams with Low Porosity and Small Pore Size

Science.gov (United States)

Cheng, Ying; Li, Yanxiang; Chen, Xiang; Liu, Zhiyong; Zhou, Xu; Wang, Ningzhen

2018-06-01

Compared to traditional pore structure with high porosity (≥ 80 pct) and large pore size (≥ 3 mm), aluminum foams with low porosity (60 to 70 pct) and small pore size (≤ 2 mm) possess higher compressive property and formability. In order to achieve the goal of reducing pore size, Cu-TiH2 composite powder prepared by ball milling preoxidized TiH2 with Cu powder was used as a blowing agent. Its gas release behavior was characterized by thermogravimetric analysis and differential scanning calorimetry. The results show that the ball milling treatment can advance the gas release process and slow the gas release rate at the same time. All these changes are favorable to the reduction of porosity and pore size. Such Cu-TiH2 composite powder provides an alternative way to fabricate aluminum foams with low porosity and small pore size.

Evaporation of new refrigerants on tube with improved surfaces. Final report. Appendices: A, B, C, D, E and F; Evaporation de nouveaux refrigerants sur des tubes a surface amelioree. Rapport final. Annexes: A, B, C, D, E et F

Energy Technology Data Exchange (ETDEWEB)

Kattan, N.; Favrat, D.; Thome, J. R.; Nidegger, E.; Zuercher, O. [Ecole Polytechnique Federale, Lab. d` Energetique Industrielle (LENI), Lausanne (Switzerland)

1995-07-15

The substitution of old refrigerants in refrigeration systems, heat pumps and organic Rankine cycles for heat recovery, request a good knowledge of heat transfer properties of substitute fluids. The test measurements in LENI test facility (concentric tubes with water flowing in a counter-current flow) with new refrigerants like HFC134a, HCFC123, R-402A, have established a new data bank with new refrigerants, a comparison with old refrigerants like CFC11, CFC12 CFC/HCFC502 and with existent correlations. Correlations were programmed to calculate and compare heat transfer coefficient during the tests. To develop a new correlation based on flow regimes, a high speed Sony video tape camera is used to observe and identify flow patterns. Important images are captured, digitalized, stored for later analysis and sent to a color plotter. Several flow pattern maps were programmed and compared to flow regimes observed on the test rig. Local flow boiling heat transfer coefficients were measured for HFC134a and HCFC123 evaporating inside a microfin tube. In addition, microheat transfer augmentation relative to plain tube test data was investigated. The presence of oil in the evaporator has an effect on heat transfer coefficient. Local flow boiling heat transfer coefficients were measured for refrigerant HFC134a-oil ester (Mobil EAL Arctic 68). A new thermodynamic approach for modeling mixtures of refrigerants and lubricating oils is developed. A very high accuracy, straight vibrating tube type of density flowmeter is used to measure oil concentrations of flowing HFC134a-oil mixtures. (author) figs., tabs., refs.

Refrigeration plants using carbon dioxide as refrigerant: measuring and modelling the solubility and diffusion of carbon dioxide in polymers used as sealing materials

DEFF Research Database (Denmark)

von Solms, Nicolas; Kristensen, Jakob

2010-01-01

Because of increased environmental pressure, there is currently a movement away from more traditional refrigerants such as HCFC's toward refrigerants with lower global warming potential such as carbon dioxide (CO2). However, the use of CO2 as a refrigerant requires a refrigeration cycle...

78 FR 21871 - Protection of Stratospheric Ozone: Revision of the Venting Prohibition for Specific Refrigerant...

Science.gov (United States)

2013-04-12

... in retail food refrigerators and freezers (standalone units only). Table of Contents I. General... and sorting recyclable materials from non- hazardous waste streams (e.g., scrap yards) and merchant... Register GWP--Global warming potential HCFC-22--the chemical chlorodifluoromethane, CAS Reg No. 75-45-6...

Condensation of refrigerants in horizontal, spirally grooved microfin tubes: Numerical analysis of heat transfer in the annular flow regime

Energy Technology Data Exchange (ETDEWEB)

Nozu, S; Honda, H

2000-02-01

A method is presented for estimating the condensation heat transfer coefficient in a horizontal, spirally grooved microfin tube. Based on the flow observation study performed by the authors, a laminar film condensation model in the annular flow regime is proposed. The model assumes that all the condensate flow occurs through the grooves. The condensate film is segmented into thin and thick film regions. In the thin film region formed on the fin surface, the condensate is assumed to be drained by the combined surface tension and vapor shear forces. In the thick film region formed in the groove, on the other hand, the condensate is assumed to be driven by the vapor shear force. The present and previous local heat transfer data including four fluids (CFC11, HCFC22, HCFC123, and HFCl34a) and three microfin tubes are found to agree with the present predictions to a mean absolute deviation of 15.1%.

Study of the parameters solution blow spinning technique in the obtaining of mullite nanofibers; Estudo de parametros da tecnica de fiacao por sopro em solucao na obtencao de nanofibras de mulita

Energy Technology Data Exchange (ETDEWEB)

Severo, L.L.; Farias, R.M.C.; Menezes, R.R.; Santos, M.A., E-mail: lucasleite_14.1@hotmail.com [Universidade Federal de Campina Grande (UFCG), PB (Brazil)

2016-07-01

The Solution Blow Spinning (SBS) technique which use aerodynamic forces and has a high production rate, was created for production of nanofiber with versatile way, such as electrospinning. Therefore, the objective is to analyze the process parameters in order to optimize the production of mullite nanofiber using the SBS technique to determine the influence of air pressure, the concentration of the polymer and ejection rate in the diameter of the fibers. For this, it was used PVC as polymer in spinning, tetrahydrofuran as the solvent, HCl as acidifying, aluminum nitrate nonahydrate and tetraethylorthosilicate as precursors of mullite. The nanofibers obtained were heat treated at 1100°C. From of XRD and SEM results, it was proved the achievement of mullite nanofiber, and STATISTICA 7 software revealed that only ejection rate and the concentration influence in the average diameters of the fibers. (author)

Potential Alternative Lower Global Warming Refrigerants for Air Conditioning in Hot Climates

Energy Technology Data Exchange (ETDEWEB)

Abdelaziz, Omar [ORNL; Shrestha, Som S [ORNL; Shen, Bo [ORNL

2017-01-01

The earth continues to see record increase in temperatures and extreme weather conditions that is largely driven by anthropogenic emissions of warming gases such as carbon dioxide and other more potent greenhouse gases such as refrigerants. The cooperation of 188 countries in the Conference of the Parties in Paris 2015 (COP21) resulted in an agreement aimed to achieve a legally binding and universal agreement on climate, with the aim of keeping global warming below 2 C. A global phasedown of hydrofluorocarbons (HFCs) can prevent 0.5 C of warming by 2100. However, most of the countries in hot climates are considered as developing countries and as such are still using R-22 (a Hydrochlorofluorocarbon (HCFC)) as the baseline refrigerant and are currently undergoing a phase-out of R-22 which is controlled by current Montreal Protocol to R-410A and other HFC based refrigerants. These HFCs have significantly high Global Warming Potential (GWP) and might not perform as well as R-22 at high ambient temperature conditions. In this paper we present recent results on evaluating the performance of alternative lower GWP refrigerants for R-22 and R-410A for small residential mini-split air conditioners and large commercial packaged units. Results showed that several of the alternatives would provide adequate replacement for R-22 with minor system modification. For the R-410A system, results showed that some of the alternatives were almost drop-in ready with benefit in efficiency and/or capacity. One of the most promising alternatives for R-22 mini-split unit is propane (R-290) as it offers higher efficiency; however it requires compressor and some other minor system modification to maintain capacity and minimize flammability risk. Between the R-410A alternatives, R-32 appears to have a competitive advantage; however at the cost of higher compressor discharge temperature. With respect to the hydrofluoroolefin (HFO) blends, there existed a tradeoff in performance and system design

Environmental Forensics

Science.gov (United States)

2011-03-29

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

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

Science.gov (United States)

2010-07-01

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

Journal of Earth System Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

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

Evaporation of new refrigerants on tubes with improved surfaces; Evaporation de nouveaux refrigerants sur des tubes a surface amelioree

Energy Technology Data Exchange (ETDEWEB)

Kattan, N.; Favrat, D.; Thome, J. R.; Nidegger, E.; Zuercher, O. [Ecole Polytechnique Federale, Lab. d` Energetique Industrielle (LENI), Lausanne (Switzerland)

1995-07-15

The substitution of old refrigerants in refrigeration systems, heat pumps and organic Rankine cycles for heat recovery, request a good knowledge of heat transfer properties of substitute fluids. The test measurements in LENI test facility (concentric tubes with water flowing in a counter-current flow) with new refrigerants like HFC134a, HCFC123, R-404A, R-402A, have established a new data bank with new refrigerants, a comparison with old refrigerants like CFC11, CFC12 CFC/HCFC502 and with existent correlations. Correlations were programmed to calculate and compare heat transfer coefficient during the tests. To develop a new correlation based on flow regimes, a high speed Sony video tape camera is used to observe and identify flow patterns. Important images are captured, digitalized, stored for later analysis and sent to a color plotter. Several flow pattern maps were programmed and compared to flow regimes observed on the test rig. Local flow boiling heat transfer coefficients were measured for HFC134a and HCFC123 evaporating inside a microfin tube. In addition, microfin heat transfer augmentation relative to plain tube test data was investigated. The presence of oil in the evaporator has an effect on heat transfer coefficient. Local flow boiling heat transfer coefficients were measured for refrigerant HFC134a-oil ester (Mobil EAL Arctic 68). A new thermodynamic approach for modeling mixtures of refrigerants and lubricating oils is developed. A very high accuracy, straight vibrating tube type of density flowmeter is used to measure oil concentrations of flowing HFC134a-oil mixtures. (author) 28 figs., 25 refs.

Loading and stress analysis of gas pipeline structures; Analise de esforcos e tensoes em estruturas de gasodutos durante despressurizacoes

Energy Technology Data Exchange (ETDEWEB)

Frisoli, Caetano [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil); Frota, Cristiane Souto [TBG - Transportadora Brasileira Gasoduto Bolivia Brasil S.A., Rio de Janeiro, RJ (Brazil); Silva, Luis Fernando Figueira da; Carvalho, Marcio da Silveira [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil). Dept. de Engenharia Mecanica; Savi, Marcelo Amorim [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Dept. de Engenharia Mecanica; Pacheco, Pedro Manuel Calas Lopes [Centro Federal de Educacao Tecnologica do Rio de Janeiro (CEFET-RJ), Rio de Janeiro, RJ (Brazil)

2003-07-01

Repairing and maintenance activities on Bolivia-Brazil gas pipeline often need blow down lines. During the blow down process, the high speed of discharging gases imposes great efforts to the structures. A detailed analysis of this situation is essential for a safe operation. This paper describes two phases of a project, developed under TBG coordination. It consists in analyzing the stress and forces involved in this operation, in order to design facilities to blow down pipes and develop a safe blow down procedure for the gas pipeline. The first phase consists of a supersonic flowing simulation in the blow down gas pipeline device. The pressure behavior, mass flow and the speed at the device's ending point are calculated for different operational conditions. In the second phase, the equivalent loading caused by blow down operations is used as input in a stress analysis program to determine stress, critical sessions evaluation and material recommendations for blow down devices. (author)

Sugar Blowing-Induced Porous Cobalt Phosphide/Nitrogen-Doped Carbon Nanostructures with Enhanced Electrochemical Oxidation Performance toward Water and Other Small Molecules

Energy Technology Data Exchange (ETDEWEB)

Zhu, Chengzhou [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Fu, Shaofang [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Xu, Bo Z. [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Song, Junhua [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Shi, Qiurong [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Engelhard, Mark H. [Environmental Molecular Science Laboratory, Pacific Northwest National Laboratory, Richland WA 99352 USA; Li, Xiaolin [Energy and Environmental Directory, Pacific Northwest National Laboratory, Richland WA 99352 USA; Beckman, Scott P. [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Sun, Junming [The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman WA 99164 USA; Du, Dan [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA; Lin, Yuehe [School of Mechanical and Materials Engineering, Washington State University, Pullman WA 99164 USA

2017-06-28

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.

Blowing loop in the EL-4 reactor: CO{sub 2} flow control analogue study; Boucle de soufflage de la centrale EL-4 - regulation du debit CO{sub 2} - etude analogique

Energy Technology Data Exchange (ETDEWEB)

Chazal, G; Merle, J P; Guillemard, B [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Leroy, C; Robin, L; Jacquin, J C; Cornudet, A [Societe INDATOM, France (France)

1966-07-01

This report describes one study which contributed to the construction of the Monts d'Arree nuclear power station: EL-4. The reactor is cooled by a CO{sub 2} current provided by 3 turbo-blower groups. The priming vapour for the turbines is taken at the exit of the main CO{sub 2} - H{sub 2}O exchangers. The operation of EL 4 is based on a high degree of centralization of the controls which attributes an important role to the general regulation circuits. This general regulation includes in particular an internal blowing loop which controls the CO{sub 2} flow. The study of the control of this CO{sub 2} flow is made up of 3 parts: - analogue representation of the reactors cooling circuit and of the turbo blower unit. - first test campaign using the analogue computer describing the natural behaviour of the system in the absence of control. theoretical determination of the regulation factors; definition of the regulation using an analogue computer and second test campaign for recording the performances of the blowing loop. The 4. part of the report deals with the analogue study: analogue equations - development. (authors) [French] Ce rapport prend place parmi les etudes de realisation de la Centrale des Monts d'Arree EL-4. Le reacteur est refroidi par une circulation de CO{sub 2} assuree par 3 groupes turbosoufflantes. La vapeur d'entrainement des turbines est prelevee a la sortie des echangeurs principaux CO{sub 2} - H{sub 2}O. L'exploitation de EL-4 repose sur une centralisation poussee des moyens de controle-commande qui attribue un role essentiel aux circuits de regulation generale. Cette regulation generale comporte en particulier une boucle interne de soufflage qui realise un asservissement du debit de CO{sub 2}. L'etude de cette regulation du debit CO{sub 2} comprend 3 parties: - representation analogique du circuit de refroidissement du reacteur et de l'ensemble turbine-soufflante. - premiere campagne d'essais sur calculateur analogique decrivant le comportement

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-11-15

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

Matters which shorten the ozone layer; Substances qui appauvrissent la couche d'ozone

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-12-01

This document, proposed by the ministry of the national development and the environment, gives the list of the main texts relative to the matters which shorten the ozone layer and the evolution of the community regulations in this domain. The concerned matters are the Cfc and the HCFC production and use. (A.L.B.)

Genome-wide RNAi screening identifies genes inhibiting the migration of glioblastoma cells.

Directory of Open Access Journals (Sweden)

Jian Yang

Full Text Available Glioblastoma Multiforme (GBM cells are highly invasive, infiltrating into the surrounding normal brain tissue, making it impossible to completely eradicate GBM tumors by surgery or radiation. Increasing evidence also shows that these migratory cells are highly resistant to cytotoxic reagents, but decreasing their migratory capability can re-sensitize them to chemotherapy. These evidences suggest that the migratory cell population may serve as a better therapeutic target for more effective treatment of GBM. In order to understand the regulatory mechanism underlying the motile phenotype, we carried out a genome-wide RNAi screen for genes inhibiting the migration of GBM cells. The screening identified a total of twenty-five primary hits; seven of them were confirmed by secondary screening. Further study showed that three of the genes, FLNA, KHSRP and HCFC1, also functioned in vivo, and knocking them down caused multifocal tumor in a mouse model. Interestingly, two genes, KHSRP and HCFC1, were also found to be correlated with the clinical outcome of GBM patients. These two genes have not been previously associated with cell migration.

Condensation heat transfer coefficients of flammable refrigerants on various enhanced tubes

International Nuclear Information System (INIS)

Park, Ki Jung; Jung, Dong Soo

2005-01-01

In this study, external condensation Heat Transfer Coefficients (HTCs) of six flammable refrigerants of propylene (R1270), propane (R290), isobutane (R600a), butane (R600), dimethylether (RE170), and HFC32 were measured at the vapor temperature of 39 .deg. C on a 1023 fpm low fin and turbo-C tubes. All data were taken under the heat flux of 32∼116 and 42∼142 kW/m 2 for the low fin and turbo-C tubes respectively. Flammable refrigerants' data obtained on enhanced tubes showed a typical trend that external condensation HTCs decrease with increasing wall subcooling. HFC32 and DME showed up to 30% higher HTCs than those of HCFC22 due to their excellent thermophysical properties. Propylene, propane, isobutane, and butane showed similar or lower HTCs than those of HCFC22. Beatty and Katz' correlation predicted the HTCs of the flammable refrigerants obtained on a low fin tube within a mean deviation of 7.3%. Turbo-C tube showed the best performance due to its 3 dimensional surface geometry for fast removal of condensate

Determination of trifluoroacetic acid in 1996--1997 precipitation and surface waters in California and Nevada

Energy Technology Data Exchange (ETDEWEB)

Wujcik, C.E.; Cahill, T.M.; Seiber, J.N. [Univ. of Nevada, Reno, NV (United States)

1999-05-15

The atmospheric degradation of three chlorofluorocarbon (CFC) replacement compounds, namely HFC-134a, HCFC-123, and HCFC-124, results in the formation of trifluoroacetic acid (TFA). Concentrations of TFA were determined in precipitation and surface water samples collected in California and Nevada during 1996--1997. Terminal lake systems were found to have concentrations 4--13 times higher than their calculated yearly inputs, providing evidence for accumulation. The results support dry deposition as the primary contributor of TFA to surface waters in arid and semiarid environments. Precipitation samples obtained from three different locations contained 20.7--1530 ng/L with significantly higher concentrations in fogwater over rainwater. Elevated levels of TFA were observed for rainwater collected in Nevada over those collected in California, indicating continual uptake and concentration as clouds move from a semiarid to arid climate. Thus several mechanisms exist, including evaporative concentration, vapor-liquid phase partitioning, lowered washout volumes of atmospheric deposition water, and dry deposition, which may lead to elevated concentrations of TFA in atmospheric and surface waters above levels expected from usual rainfall washout.

Process of cleaning oil spills and the like

International Nuclear Information System (INIS)

Breisford, J.A.

1993-01-01

A process of cleaning spills of toxic or hazardous materials such as oil, antifreeze, gasoline, and the like from bodies of water, garage floors, roadways and the like, comprising spraying unbonded shredded fiberglass blowing wool composition particles onto the spill, absorbing the spill into the shredded fiberglass blowing wool composition particles, and removing the soaked shredded fiberglass blowing wool composition particles and the spill absorbed therein. An absorbent composition for absorbing spills of toxic or hazardous materials such as oil, antifreeze, gasoline, and like, comprising shredded fiberglass blowing wool particles, and means for absorbing the spill and for stiffening the co-position so that the composition fights against being compressed so that less of the absorbed spill escapes from the composition when it is being removed from the spill, said means including cork particles dispersed in with the fiberglass blowing wool particles. An absorbent sock for absorbing or containing a spill of toxic or hazardous materials such as oil, antifreeze, gasoline, and the like, comprising a hollow tube, said tube being permeable to the toxic or hazardous materials and being made of nylon or polypropylene, and unbonded, shredded fiberglass blowing wool composition particles enclosed in the tube. Apparatus for controlling an oil slick on the surface of water, comprising a craft for traversing the slick, a supply of fiberglass blowing wool composition particles stored on the craft in position for being dispersed, shredding means on the craft for shredding the fiberglass blowing wool particles to form unbonded, shredded fiberglass blowing wool particles, and dispensing means on the craft for dispensing the unbonded, shredded fiberglass blowing wool particles onto the slick

Carbon Dioxide as Secondary Refrigerant in Supermarkets

DEFF Research Database (Denmark)

Knudsen, Hans Jørgen Høgaard

Resume I forbindelse med udfasning af HCFC- og HFC-kølemidlerne er opstået stor interesse for anvendelse af naturlige kølemidler samt indirekte køling i forbindelse med køling i supermarkeder. Som sekundært kølemiddel med faseskift kan kuldioxid anvendes. I supermarkeder med køleanlægget placeret...

New beam-based and direct magnetic waveform measurements of the BTx.KFA10(20) vertical recombination kickers and induced emittance blow-up simulations at 1.4 and 2 GeV

CERN Document Server

Forte, Vincenzo; Borburgh, Jan; Sermeus, Luc; CERN. Geneva. ATS Department

2018-01-01

In the framework of the LHC Injectors Upgrade (LIU) project [1], this document summarises a new reconstruction methodology for the measurement of the magnetic waveforms of the vertical re-combination kickers BT1.KFA10, BT4.KFA10 and BT2.KFA20, from data collected during several Machine Development (MD) sessions. The reconstruction has been performed in order to verify the LIU specification of the recombination kickers, which is required for a clean transfer of the longer bunches coming from the PSB after the upgrade. A beam-based methodology was developed to measure the transient magnetics dynamics of the kicker where the bunch length is comparable to the rise and/or fall times. These measurements represent a valuable way to reconstruct the mag-netic waveform of the kickers where removing them to make direct probe measurements is time consuming. A benchmarking of the beam-based measurements with field probe measurements is presented, together with realistic simulations of the vertical emittance blow-up at 1...

Tensile Properties and Fracture Behavior of Aluminum Alloy Foam Fabricated from Die Castings without Using Blowing Agent by Friction Stir Processing Route.

Science.gov (United States)

Hangai, Yoshihiko; Kamada, Hiroto; Utsunomiya, Takao; Kitahara, Soichiro; Kuwazuru, Osamu; Yoshikawa, Nobuhiro

2014-03-21

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.

Cryptogenic transient ischemic attack after nose blowing: association of huge atrial septal aneurysm with patent foramen ovale as potential cause

Directory of Open Access Journals (Sweden)

Lotze U

2013-07-01

aneurysm, nose blowing, paradoxical embolism, patent foramen ovale, transient ischemic attack

Quantitative pteridine fluorescence analysis: A possible age-grading technique for the adult stages of the blow fly Calliphora vicina (Diptera: Calliphoridae).

Science.gov (United States)

Bernhardt, Victoria; Hannig, Laura; Kinast, Ronja; Verhoff, Marcel A; Rothweiler, Florian; Zehner, Richard; Amendt, Jens

2017-04-01

Age estimation of adult flies could extend the possible window of time for calculating the minimal postmortem interval (PMI min ) by means of entomological methods. Currently, this is done by estimating the time required by necrophagous Diptera to reach certain juvenile developmental landmarks, and the method only works until the end of metamorphosis and emergence of the adult fly. Particularly at indoor crime scenes, being able to estimate the age of trapped adult flies would be an important tool with which to extend the calculable PMI beyond the developmental period. Recently, several promising age-dependent morphological and physiological characteristics of adult insects have been investigated in medical and forensic entomology, but the results are still preliminary and restricted to a few species. We examined adults of the forensically relevant blow fly species Calliphora vicina and investigated the fluorescence levels of pteridine, a group of metabolites that accumulates in the eyes during aging. From Day 1 to Day 25 post-emergence, flies were kept at three different temperature regimes (20°C, 25°C, and fluctuating temperatures in the context of a field study) and 12:12 L:D. From Day 1 until Day 7, the fluorescence of pteridine was determined on a daily basis, and thereafter, every three days. The achieved fly age was multiplied with the relevant temperature and converted into accumulated degree-days (ADD). The fluorescence level of pteridine increased linear with increasing ADD (females: R 2 =0.777; males: R 2 =0.802). The difference between sexes was significant (pstage (female abdomen). Copyright © 2017 Elsevier Ltd. All rights reserved.

Glass solidification material confinement test device

International Nuclear Information System (INIS)

Namiki, Shigekazu.

1997-01-01

In a device for confining glass solidification materials, a pipeline connecting a detection vessel and a detector is formed to have a double walled structure, and air blowing holes are formed on the wall of the inner pipe, and an air supply mechanism is connected to inner and outer pipes for supplying blowing air thereby preventing deposition on the inner pipe wall. The air blowing holes are formed by constituting the pipe by using a porous sintered material and porous portions thereof are defined as the air blowing holes, or holes are formed on the pipe wall made of a metal by machining. A blowing boundary layer is formed by blowing the supplied air along the pipe wall of the inner pipe, by which deposition of the sucked materials to the inner wall of the inner pipe is prevented, and all of the materials sucked from the detection vessel are collected to the detector. In addition, an air exit pipe is formed into a double walled structure so as to be supplied blowing air from the air supply mechanism thereby enabling to prevent deposition of sucked materials more reliably. (N.H.)

Prospective Teachers' Value Orientations as Determinants of Preference for External and Anonymous Whistleblowing

Science.gov (United States)

Gokce, Asiye Toker

2013-01-01

Whistle-blowing indicates disclosing organizational wrongdoings resulting in harm to third parties. An individual's decision to blow the whistle might be based upon organizational, situational or personal factors. This study inquires the relationship between value orientations of prospective teachers and choices for whistle-blowing with particular…

Rate constants for the gas-phase reactions of OH radicals with CH₃CHF₂ and CHCl₂CF₃ over the temperature range 295-388 K

DEFF Research Database (Denmark)

Nielsen, O.J.

1991-01-01

be fit to the Arrhenius expressions: k(OH + HFC-152a) = 3.9 X 10(-12) exp[(-1370 +/- 260)/T] cm3 molecule-1 s-1 and k(OH + HCFC-123) = 1.1 X 10(-12) X exp[(-940 +/- 200)/T] cm3 molecule-1 s-1. The results are compared to the available literature data and discussed in terms of reactivity trends...

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

The collision of masses and the way prices react to expectations

Science.gov (United States)

Chavez-Guzman, Luis

2004-12-01

When a body is impacted by other bodies its position is determined by the force of the impacts, likewise the price of a share is determined by expectations. This study intents to establish taxonomy of expectations based on the different types of impacts a body can receive, these can be: a blow without penetration, a blow that penetrates and stays in the body, a blow that goes through the body without affecting the body mass, and lastly, a blow that reduces but does not penetrate the body mass.

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.

Relationships of site of impact to CT findings and outcome in diffuse brain injury

International Nuclear Information System (INIS)

Saito, Akihito; Kuwana, Nobumasa; Mochimatsu, Yasuhiko; Tanaka, Naoki; Fujino, Hideyo

1985-01-01

The relationships of the site of impact to the CT findings and to the severity and outcome of an injury were analysed based on 50 cases of diffuse brain injury (DBI). The CT findings of DBI were classified into 5 types: diffuse cerebral swelling (DCS); isodensity hemispheric swelling (IHS); deep-seated brain injury (DSI); subarachnoid hemorrhage (SAH), and normal finding (N). The sites of the impact were frontal in 19 cases, temporal in 8 cases, parietal in 4 cases, occipital in 12 cases, and multiple or undetermined in 7 cases. Frontal blows resulted in the lowest mortality rate (5.3%); on the other hand, occipital blows resulted in the highest (58%). Additionally, occipital blows caused the highest primary brain-stem injury, i.e., 41.7%. The frontal region was the most common impact area, revealing DCS and N. Temporal blows commonly resulted in DSI. Parietal blows were characteristic causes of IHS cases. However, occipital blows generally demonstrated no specific tendencies with regard to the type of CT finding. Based on this study, it is evident that CT findings and outcomes are influenced by the location of the impact. It is the authors' impression that, in severe head-injury cases, occipital blows, which are usually associated with primary brain-stem injuries, are the most serious. (author)

Relationships of site of impact to CT findings and outcome in diffuse brain injury

Energy Technology Data Exchange (ETDEWEB)

Saito, Akihito; Kuwana, Nobumasa; Mochimatsu, Yasuhiko; Tanaka, Naoki; Fujino, Hideyo

1985-02-01

The relationships of the site of impact to the CT findings and to the severity and outcome of an injury were analysed based on 50 cases of diffuse brain injury (DBI). The CT findings of DBI were classified into 5 types: diffuse cerebral swelling (DCS); isodensity hemispheric swelling (IHS); deep-seated brain injury (DSI); subarachnoid hemorrhage (SAH), and normal finding (N). The sites of the impact were frontal in 19 cases, temporal in 8 cases, parietal in 4 cases, occipital in 12 cases, and multiple or undetermined in 7 cases. Frontal blows resulted in the lowest mortality rate (5.3%); on the other hand, occipital blows resulted in the highest (58%). Additionally, occipital blows caused the highest primary brain-stem injury, i.e., 41.7%. The frontal region was the most common impact area, revealing DCS and N. Temporal blows commonly resulted in DSI. Parietal blows were characteristic causes of IHS cases. However, occipital blows generally demonstrated no specific tendencies with regard to the type of CT finding. Based on this study, it is evident that CT findings and outcomes are influenced by the location of the impact. It is the authors' impression that, in severe head-injury cases, occipital blows, which are usually associated with primary brain-stem injuries, are the most serious. (author).

A Correlation for Forced Convective Boiling Heat Transfer of Refrigerants in a Microfin Tube

Science.gov (United States)

Momoki, Satoru; Yu, Jian; Koyama, Shigeru; Fujii, Tetsu; Honda, Hiroshi

The experimental study is reported on the forced convective boiling of pure refrigerants HCFC22, HFC134a and HCFC123 flowing in a horizontal microfin tube. The local heat transfer coefficient defined based on the actual inside surface area is measured in the ranges of mass velocity of 200 to 400 kg/m2s, heat flux of 5 to 64 kW/m2 and reduced pressure of 0.07 to 0.24. Using the Chen-type model, a new correlation for microfin tubes is proposed considering the enhancement effect of microfins on both the convective heat transfer and the nucleate boiling components. In the convective heat transfer component, the correlation to predict the heat transfer coefficient of liquid-only flow is determined from preliminary experiments on single-phase flow in microfin tubes, and the two-phase flow enhancement factor is determined from the present experimental data. For the nucleate boiling component, the correlation of Takamatsu et al. for smooth tube is modified. The prediction of the present correlation agrees well with present experimental data, and is available for several microfin tubes which were tested by other researchers.

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-03-01

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

Experimental investigation of different fluid flow profiles in a rotary multi-bed active magnetic regenerator device

DEFF Research Database (Denmark)

Fortkamp, F. P.; Eriksen, D.; Engelbrecht, K.

2018-01-01

A rotary multi-bed active magnetic regenerator (AMR) device was modified to allow testing different fluid flow waveforms, with different blow fractions (i.e. the fraction of the AMR cycle when there is fluid flow in the regenerators). The different values of blow fraction were generated using dif.......1% was obtained for the largest blow fraction tested (80%). Designs for magnetic refrigerators where the fluid flow waveform can change during operation are also discussed in this paper.......A rotary multi-bed active magnetic regenerator (AMR) device was modified to allow testing different fluid flow waveforms, with different blow fractions (i.e. the fraction of the AMR cycle when there is fluid flow in the regenerators). The different values of blow fraction were generated using...... different cam rings that actuate the poppet valves at the inlet and outlet of the regenerators, controlling how long the valves stay open and the number of valves open at the same time. Results showed that smaller blow fractions yield higher values of temperature span for fixed flow rate and cooling...

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.

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

Flight Investigation of the Low-Speed Characteristics of a 45 deg Swept-Wing Fighter-Type Airplane with Blowing Boundary-Layer Control Applied to the Leading- and Trailing-Edge Flaps

Science.gov (United States)

Quigley, Hervey C.; Anderson, Seth B.; Innis, Robert C.

1960-01-01

A flight investigation has been conducted to study how pilots use the high lift available with blowing-type boundary-layer control applied to the leading- and trailing-edge flaps of a 45 deg. swept-wing airplane. The study includes documentation of the low-speed handling qualities as well as the pilots' evaluations of the landing-approach characteristics. All the pilots who flew the airplane considered it more comfortable to fly at low speeds than any other F-100 configuration they had flown. The major improvements noted were the reduced stall speed, the improved longitudinal stability at high lift, and the reduction in low-speed buffet. The study has shown the minimum comfortable landing-approach speeds are between 120.5 and 126.5 knots compared to 134 for the airplane with a slatted leading edge and the same trailing-edge flap. The limiting factors in the pilots' choices of landing-approach speeds were the limits of ability to control flight-path angle, lack of visibility, trim change with thrust, low static directional stability, and sluggish longitudinal control. Several of these factors were found to be associated with the high angles of attack, between 13 deg. and 15 deg., required for the low approach speeds. The angle of attack for maximum lift coefficient was 28 deg.

Visualization of airflow growing soap bubbles

Science.gov (United States)

Al Rahbi, Hamood; Bock, Matthew; Ryu, Sangjin

2016-11-01

Visualizing airflow inside growing soap bubbles can answer questions regarding the fluid dynamics of soap bubble blowing, which is a model system for flows with a gas-liquid-gas interface. Also, understanding the soap bubble blowing process is practical because it can contribute to controlling industrial processes similar to soap bubble blowing. In this study, we visualized airflow which grows soap bubbles using the smoke wire technique to understand how airflow blows soap bubbles. The soap bubble blower setup was built to mimic the human blowing process of soap bubbles, which consists of a blower, a nozzle and a bubble ring. The smoke wire was placed between the nozzle and the bubble ring, and smoke-visualized airflow was captured using a high speed camera. Our visualization shows how air jet flows into the growing soap bubble on the ring and how the airflow interacts with the soap film of growing bubble.

Active Control of Flow Separation Over an Airfoil

Science.gov (United States)

Ravindran, S. S.

1999-01-01

Designing an aircraft without conventional control surfaces is of interest to aerospace community. In this direction, smart actuator devices such as synthetic jets have been proposed to provide aircraft maneuverability instead of control surfaces. In this article, a numerical study is performed to investigate the effects of unsteady suction and blowing on airfoils. The unsteady suction and blowing is introduced at the leading edge of the airfoil in the form of tangential jet. Numerical solutions are obtained using Reynolds-Averaged viscous compressible Navier-Stokes equations. Unsteady suction and blowing is investigated as a means of separation control to obtain lift on airfoils. The effect of blowing coefficients on lift and drag is investigated. The numerical simulations are compared with experiments from the Tel-Aviv University (TAU). These results indicate that unsteady suction and blowing can be used as a means of separation control to generate lift on airfoils.

Imulation of polymer forming processes - addressing industrial needs

International Nuclear Information System (INIS)

Thibault, F.; DiRaddo, R.

2011-01-01

The objective of this paper is to present the development of simulation and design optimization capabilities, for polymer forming processes, in the context of addressing industrial needs. Accomplishments generated from close to twenty years of research in this field, at the National Research Council (NRC), are presented. Polymer forming processes such as extrusion blow moulding, stretch blow moulding and thermoforming have been the focus of the work, yet the research is extendable to similar polymer forming operations such as micro-blow moulding, sheet blow moulding and composites stamping. The research considers material models, process sequence integration and design optimization, derivative processes and 3D finite elements with multi-body contact.

Replacement of CFCs in thermodynamical systems; Remplacement des C.F.C. dans les systemes thermodynamiques

Energy Technology Data Exchange (ETDEWEB)

Fleurance, M.

1996-12-31

Following the Montreal protocol and the withdrawal of the CFC-type refrigerating fluids, York France company has developed and adapted its equipments to new refrigerants. Each user will have to know how to define the best option for his installation: opting for or ignoring the withdrawal of CFCs, confining the installations, changing for new intermediate substitutes (HCFC-type), or changing or replacing with new long term substitutes (HFCs). (J.S.)

Study on the flow of molten polymers in a mold an investigation on mold printability; Kobunshi yoyutai no kanagatanai bisho ryudo. Kanagata tenshasei no kenkyu

Energy Technology Data Exchange (ETDEWEB)

Kano, Y.; Nishimura, T.; Ito, S. [Ube Industries Ltd. Yamaguchi (Japan)] Usui, H. [Kobe Univ. (Japan)] Saeki, T. [Yamaguchi Univ. (Japan)

1998-09-15

A visualization experiment was carried out using a small metal mold with rectangular grooves as a mold printable model to observe the micro-flow of molten polymer in a metal mold. The glitter, which is an index of printability, was correlated with blow velocity and space area. Since it is highly correlated with space area, it can be thought that filling up well the fine grooves of mold heighten the glitter and printability as well. The effect of such factors as mold temperature, polymer melt temperature, air blow pressure and air blow velocity on the mold printability was investigated. For high density polyethylene and polypropylene, the glitter depended the most on the mold temperature. The higher the temperature, the higher the glitter. It was also found that the increase in blow pressure was effective. For high density polyethylene, the effect of blow velocity and polymer melt temperature was also recognized. 3 refs., 6 figs., 3 tabs.

On the Active and Passive Flow Separation Control Techniques over Airfoils

Science.gov (United States)

Moghaddam, Tohid; Banazadeh Neishabouri, Nafiseh

2017-10-01

In the present work, recent advances in the field of the active and passive flow separation control, particularly blowing and suction flow control techniques, applied on the common airfoils are briefly reviewed. This broad research area has remained the point of interest for many years as it is applicable to various applications. The suction and blowing flow control methods, among other methods, are more technically feasible and market ready techniques. It is well established that the uniform and/or oscillatory blowing and suction flow control mechanisms significantly improve the lift-to-drag ratio, and further, postpone the boundary layer separation as well as the stall. The oscillatory blowing and suction flow control, however, is more efficient compared to the uniform one. A wide range of parameters is involved in controlling the behavior of a blowing and/or suction flow control, including the location, length, and angle of the jet slots. The oscillation range of the jet slot is another substantial parameter.

Processo de congelamento em túnel portátil com convecção forçada por exaustão e insuflação para paletes Freezing process evaluation using a portable forced air system with air evacuation and air blowing in pallets

Directory of Open Access Journals (Sweden)

Douglas Fernandes Barbin

2009-09-01

Full Text Available Este trabalho propôs a montagem experimental de um túnel portátil de congelamento por ar forçado composto por um ventilador que produz uma região de alta ou baixa pressão em um palete com produto, onde se pode avaliar o processo com a utilização de insuflação, exaustão de ar e uma combinação mista destes dois processos. O equipamento foi alocado no interior de uma câmara de estocagem de produtos congelados, buscando-se melhorar a distribuição do ar, potencializando-se a troca térmica entre o ar e o produto. Durante o congelamento, foram comparados os processos e analisada a transferência de calor entre o ar de resfriamento e o produto em diferentes posições e camadas do palete, bem como a distribuição do ar de resfriamento em circulação ao redor do produto. O processo de exaustão apresentou uma redução de 14% do tempo para o congelamento em relação à insuflação e 10% em relação ao misto.The objective of this work is to build an experimental portable forced-air freezing tunnel which creates a low or high pressure region surrounding the product. Comparative studies with air exhausting and blowing were conducted. The tunnel was built and placed inside a freezing product storage chamber, and the objective was to improve the air circulation and the thermal distribution between the product and cold air for a sample batch left inside the chamber. A heat transfer analysis comparing the process and the air distribution around the product was performed. The air evacuation process reduced up to 14% of the freezing time in relation to the blowing system and 10% in relation to the mixed system.

Pelletierung von Metallpulvern

OpenAIRE

Hannemann, Christian; Scholz, Steffen

2017-01-01

The method is solving the problem of inhomogeneous blowing agent distribution in precursor fabrication for the metal foam production. The conventional process contains a mixing procedure of metal and blowing agent powders followed by extrusion-compaction resulting in uneven pore sizes and density differences in the finally generated metal foam. Instead the new method coats metal particles with the blowing agent by spray coating, rolling processes or is using pelletizing as in-between step bef...

Study of improvement in 1st ring`s gas-seal; Top ring no gas seal seino kojo no kento

Energy Technology Data Exchange (ETDEWEB)

Ando, H; Tateishi, Y; Fujimura, K; Hitosugi, H [Nippon Piston Ring Co. Ltd., Tokyo (Japan)

1997-10-01

The authors studied the effect of an angle of 1st ring twist on the amount of blow-by concerning higher speed/higher output engines for motorcycles. As a result, the authors found the twist made the ring restrained in a ring groove of piston , and confirmed its suitable range for blow-by. By means of the developed optimization method, the authors have achieved significant reduction in blow-by at high engine speed. 1 ref., 9 figs., 2 tabs.

An Experimental Investigation of the Acoustic and Fluid Dynamic Characteristics of a Circulation-Controlled Airfoil

Science.gov (United States)

2011-05-13

insight regarding these trailing edge sources, beam maps from opposite side blowing measurements ( OSB ) are compared with SSB measurements in Figures 64 to...maps (B, D, F) corresponds to OSB . To reiterate, the array is located on the same side as the blowing slot for the SSB cases. The same and opposite...slot blowing beam maps at 992 Hz, shown in Figure 64, are nearly undistinguishable, but it is interesting that the levels are slightly higher for OSB

Electricity Storage and the Hydrogen-Chlorine Fuel Cell

Science.gov (United States)

Rugolo, Jason Steven

Electricity storage is an essential component of the transforming energy marketplace. Its absence at any significant scale requires that electricity producers sit ready to respond to every flick of a switch, constantly adjusting power production to meet demand. The dispatchable electricity production technologies that currently enable this type of market are growing unpopular because of their carbon emissions. Popular methods to move away from fossil fuels are wind and solar power. These sources also happen to be the least dispatchable. Electricity storage can solve that problem. By overproducing during sunlight to store energy for evening use, or storing during windy periods for delivery in future calm ones, electricity storage has the potential to allow intermittent renewable sources to constitute a large portion of our electricity mix. I investigate the variability of wind in Chapter 2, and show that the variability is not significantly reduced by geographically distributing power production over the entire country of the Netherlands. In Chapter 3, I calculate the required characteristics of a linear-response, constant activity storage technology to map wind and solar production scenarios onto several different supply scenarios for a range of specified system efficiencies. I show that solid electrode batteries have two orders of magnitude too little energy per unit power to be well suited for renewable balancing and emphasize the value of the modular separation between the power and energy components of regenerative fuel cell technologies. In Chapter 4 I introduce the regenerative hydrogen-chlorine fuel cell (rHCFC), which is a specific technology that shows promise for the above applications. In collaboration with Sustainable Innovations, we have made and tested 6 different rHCFCs. In order to understand the relative importance of the different inefficiencies in the rHCFC, Chapter 5 introduces a complex temperature and concentration dependent model of the rHCFC

Stall margin improvements of conventional axial flow fans with the reformed casingtreatments; Casingtreatment ni yoru han`yo jikuryu sofuki no shissoku kaizen

Energy Technology Data Exchange (ETDEWEB)

Nishioka, K.; Kuroda, H.; Obata, S.; Chimura, O. [National Defense Academy, Kanagawa (Japan); Takeishi, M.

1998-09-25

At the first part of this paper, the experiments and results to the blowing and suction on a fan are presented, and it is found that blowing toward the down stream direction are more effective and blowing location is suitable on the leading edge side of blades. On basis of these results, the reformed casingtreatments which the blowing air from the slots makes the large relative momentum for blade chord are build, and the experiments using the two conventional fans equipped with the reformed casingtreatment and conventional one are performed. So, the very large stall margin improvements (about 1.7 times) and about 0.5% efficiency penalty of 10% stall margin improvement at design flow rate are obtained for the reformed casingtreatment. 10 refs., 15 figs., 1 tab.

Predictors of responses to organizational wrongdoing: a study of intentions of management accountants.

Science.gov (United States)

Casal, Jose C; Bogui, Frederic B

2008-08-01

It has been proposed that employees aware of organizational wrongdoing face two decisions: whether or not to blow the whistle and whether or not to leave their organizations. Of these only the decision to blow the whistle has received attention, leaving a gap in knowledge; thus, a survey of 330 management accountants was analyzed to examine potential predictors of intended responses to organizational wrongdoing. Analysis of ratings indicated that intent to leave increased with seriousness of wrongdoing and expected retaliation for whistleblowing and decreased with expected effectiveness of whistleblowing. Intent to stay and blow the whistle increased with expected effectiveness of whistleblowing and role responsibility for reporting and decreased with expected retaliation for whistleblowing; intent to leave and blow the whistle increased with expected effectiveness of whistleblowing and role responsibility for reporting.

Greenhouse effect: an issue for the refrigeration and air conditioning sector; Effet de serre: quelle problematique pour le froid et le conditionnement de l`air?

Energy Technology Data Exchange (ETDEWEB)

Billiard, F. [Institut International du Froid, 75 - Paris (France)

1997-12-31

The principles of greenhouse effect and the greenhouse gas main direct and indirect emission sources due to refrigeration and air conditioning systems are first reviewed. Evolution scenarios from 1992 to 2020 and 2100 for the emissions of CFC, HCFC and HFC are presented and related to the Kyoto protocol project limitations; technical improvements in refrigerating and air conditioning systems (lower refrigerant utilization, fluid confinement, alternative technologies, natural refrigerant utilization, etc.) could lead to substantial diminutions of these greenhouse gases

Cooling performance of a notebook PC mounted with heat spreader

Energy Technology Data Exchange (ETDEWEB)

Noh, H.K. [Electronics and Telecommunications Research Institute, Taejeon (Korea); Lim, K.B. [Hanbat National University, Taejeon (Korea); Park, M.H. [Korea Power Engineering Company (Korea)

2001-06-01

Parametric study to investigate the cooling performance of a notebook PC mounted with heat spreader has been numerically performed. Two case of air-blowing and air-exhaust at inlet were tested. The cooling effect on parameters such as, inlet velocities in the cases of air-blowing and air-exhaust, materials of heat spreader, and CPU powers were simulated for two cases. Cooling performance in the case of air-blowing was better than the case of air-exhaust. (author). 9 refs., 7 figs., 5 tabs.

A Novel Method to Predict Circulation Control Noise

Science.gov (United States)

2016-03-17

and incompressibility of the flow are automatically satisfied (Sirovich, 1987). The difference be- tween these two methods stems from the...From top left to bottom right 1 kHz, 2 kHz, 4 kHz, 8 kHz, 12 kHz , and 16 kHz. blowing and lowest blowing (CJ.l = 0 and Cll = 0.004 , respectively...also shown that at low frequencies for the lower blowing conditions (Gil = 0, Gil = 0.004, and Cll = 0.017) the levels are quite similar. By using

Correlation of the manual compaction hammer with mechanical hammers for the Marshall method of design for asphaltic concrete.

Science.gov (United States)

1964-09-01

The purpose of this investigation was to establish, through a series of correlations, the compactive effort (number of blows) needed using the mechanical hammers to yield similar physical properties obtained with 75 blows of the manual hammer.

The effect of cleaning on materials wastage in biomass and waste fired power plants; Sotningens inverkan paa materialfoerluster foer bio- och avfallseldade pannor

Energy Technology Data Exchange (ETDEWEB)

Hjoernhede, Anders; Henderson, Pamela

2006-03-15

The reason for this study is the relatively large material loss caused by soot blowing of heat exchange surface in waste- and biomass fired boilers. The material losses depend on the method of cleaning: Normally soot blowing with a relatively high pressure is used in order to remove deposits on super heater tubes. However, this also damages the tube material. Earlier theories state that the material losses are caused by erosion or rather erosion-corrosion of the tube surface. There is a clear evidence for the existence for this type of damage, but it is often caused by badly adjusted soot blowing equipment. However, even well adjusted equipment causes accelerated metal loss, albeit lower than with badly adjusted soot blowers. This type of material loss is caused by the removal of the outer molten deposit layer. This outer layer of deposit actually acts as a barrier to corrosive species diffusing inwards towards the oxide and uncorroded metal. There is a lamellar oxide under this deposit, which is especially protective if it contains Cr{sub 2}O{sub 3}, MoO{sub 3} or Nb{sub 2}O{sub 5}. The lamellar oxide is damaged by the defects produced by the soot blowing and the diffusion of corrosive species into the metal tube. Since molybdenum probably through molybdenum oxide seems to reduce metal losses due to soot blowing, alloys containing molybdenum should be used. The addition of sulphur, or sulphur compounds like ammonium sulphate reduces the deposit growth rate by about 50%. This means that the soot blowing frequency and therefore metal losses are reduced. There is also an indication that certain metals or alloys reduce the tendency for deposits to stick to tubes. Coating with pure nickel is one example of this, but as nickel is sensitive to soot blowing it is not possible to use nickel in areas affected by soot blowing. A common way of reducing metal losses is to mount tube shields on the most affected tubes. These shields are changed regularly. Normally expensive