WorldWideScience

Sample records for residual air pressure

  1. Electrodialytic remediation of air pollution control residues

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland

    Air pollution control (APC) residue from municipal solid waste incineration (MSWI) consists of the fly ash, and, in dry and semi-dry systems, also the reaction products from the flue gas cleaning process. APC residue is considered a hazardous waste due to its high alkalinity, high content of salts...

  2. Evaluation of minimum residual pressure as design criterion for ...

    African Journals Online (AJOL)

    ... as the design criterion for minimum residual pressure in water distribution systems. However, the theoretical peak demand in many systems has increased beyond the point where minimum residual pressure exceeds 24 m – at least according to hydraulic models. Additions of customers to existing supply systems have led ...

  3. Electroremediation of air pollution control residues in a continuous reactor

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland; Ferreira, Célia M. D.; Hansen, Henrik K.

    2010-01-01

    Air pollution control (APC) residue from municipal solid waste incineration is considered hazardous waste due to its alkalinity and high content of salts and mobile heavy metals. Various solutions for the handling of APC-residue exist, however most commercial solutions involve landfilling. A demand...... for environmental sustainable alternatives exists and electrodialysis could be such an alternative. The potential of electrodialysis for treating APC-residue is explored in this work by designing and testing a continuous-flow bench-scale reactor that can work with a high solids content feed solution. Experiments...... were made with raw residue, water-washed residue, acid washed residue and acid-treated residue with emphasis on reduction of heavy metal mobility. Main results indicate that the reactor successfully removes toxic elements lead, copper, cadmium and zinc from the feed stream, suggesting...

  4. Electrodialytic remediation of air pollution control residues in bench scale

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland; Ferreira, Celia; Hansen, Henrik K.

    2008-01-01

    Air pollution control (APC) residue from municipal solid waste incineration (MSWI) is considered a hazardous waste due to its alkalinity and high content of salts and mobile heavy metals. Various solutions for the handling of APC-residue exist in different regions; however, most commercial...... solutions are concerned with deposition. A demand for more environmentally friendly alternatives exists. Electrodialysis could be such an alternative, and the potential is being explored. This work presents a bench scale study of the feasibility of treating APC-residue from a dry system by electrodialysis....... A system resembling conventional electrodialysis was designed and adjusted to fit the high solids content feed solution (10% APC residue, 90% water). Experiments were made in bench scale with raw residue (natural pH > 12), water pre-residue (natural pH > 12), acid pre-washed residue (pH 10), and acid...

  5. Soil and air temperature and biomass after residue treatment.

    Science.gov (United States)

    W.B. Fowler; J.D. Helvey

    1981-01-01

    Air temperature at 0.5 m and soil temperature at 0.01 m were measured during May and early June after forest harvest on four residue treatment sites and a control. Broadcast burning or burning in piles increased daily accumulation of heat in air while scattered chips and scarified and cleared treatments were equal to the control (broadcast, untreated slash). During mid...

  6. Monitoring Air Circulation Under Reduced Pressures

    Science.gov (United States)

    Rygalov, Vadim

    Adequate air circulation is required for controlled environments to maintain uniform temperature and humidity control, and hence the ability to measure air flow accurately is important. Human and associated life support habitats (e.g.,. plant production systems) for future space missions will likely be operated at pressures less than 100 kPa to minimize gas leakage and structural mass. Under such reduced pressures, the outputs from conventional anemometers for monitoring air flow can change and require re-calibration. These effects of atmospheric pressure on different types of air flow measurements are not completely understood; hence we compared the performance of several air flow sensors across a range of hypobaric pressures. Sensors included a propeller type anemometer, a hot-wire anemometer, and a Pitot-tube based device. Theoretical schematics (including mathematical models) underlying these measurements were developed. Results demonstrated that changes in sensor outputs were predictable based on their operating principles, and that corrections could be developed for sensors calibrated under normal Earth atmosphere pressure ( 100 kPa) and then used at different pressures. The potential effects of hypobaric atmospheres and their altered air flows on plant physiology are also discussed.

  7. Pesticide residues in air and water

    Energy Technology Data Exchange (ETDEWEB)

    Breidenbach, A.W.

    1965-06-01

    Current work in pesticide surveillance in surface waters is described. The methods used for sampling are briefly described. The sensitivity and specificity of the analytical techniques employed are discussed. The sampling difficulties and protocols for evaluating levels of pesticides in air pollution are briefly discussed. 17 references.

  8. A new magnetic coupling pump of residual pressure energy

    Science.gov (United States)

    Tong, Junjie; Ma, Xiaoqian; Fang, Yunhui

    2017-10-01

    A new method of magnetic coupling pump based on residual pressure is designed and the theoretical analysis and design calculation are carried out. The magnetic coupling pump device based on residual pressure is developed to achieve zero leakage during the energy conversion of two kinds of fluids. The results show that under the same displacement condition, the pressure head of the feed water is reduced with the increase of the feed water flow rate, the rotation speed of the axial impeller decreases gradually with the increase of the diameter of the drain pipe. In the case of the same water supply flow, the impeller speed increases with the increase of the displacement. When the available drainage increases, the pressure of the feed water supply increases.

  9. EFFECT OF LASER LIGHT ON LASER PLASMAS: Laser plasma at low air pressure

    Science.gov (United States)

    Vas'kovskiĭ, Yu M.; Moiseev, V. N.; Rovinskiĭ, R. E.; Tsenina, I. S.

    1993-01-01

    The dynamic and optical characteristics of the laser plasma produced during the application of a CO2 laser pulse to a target have been studied as a function of the ambient air pressure. The changes in the surface roughness of the sample after bombardment were studied as a function of the air pressure. It is concluded from the results that a transition from an air plasma to an erosion plasma occurs at a residual air pressure on the order of 1 torr. The experiment data support the existing picture of the process by which a plasma is produced near the surface of a target in air by laser pulses.

  10. Minimizing Residual Pressure within a Windowless Gas Target System - JENSA

    Science.gov (United States)

    Gomez, Orlando; Browne, Justin; Kontos, Antonios; Montes, Fernando; Jensa Collaboration

    2015-04-01

    Nuclear reactions between light gases and radioactive isotope beams are essential to address open questions in nuclear structure and astrophysics. Pure light gas targets are critical for the measurements of proton- and alpha-induced reactions. J _ et E _ xperiments in N _ uclear S _ tructure and A _ strophysics (JENSA) is the world's most dense (~ 1019 atoms/cm2) windowless gas target system. Most of the gas flow is localized; however, escaping gas creates a pressure gradient which degrades experimental measurements and contaminates the beam line. JENSA contains a differential pumping system to maintain a vacuum. The previous design configuration was not optimized for experiments (pressure measurements 70 cm downstream from the jet were ~ 10-3 torr; optimal is less than 10-4 torr). We have altered the current differential pumping system to minimize the residual pressure profile. Several configurations of two gas-receiving catchers were tested, and the most efficient ones identified using Enhanced Pirani and Cold Cathode gauges. We have determined the 30 mm outer and 20 mm inner gas-receiving cones minimize JENSA central chamber pressure to 200 millitorr at 16,000 torr of discharge pressure. Altering the tubing configuration has additionally lowered the pressure 70 cm downstream to 10-5 torr. The new residual pressure allows operation of JENSA with planned expansion of a recoil mass separator SECAR.

  11. Measurement of residual stresses in alloy 600 pressurizer penetrations

    International Nuclear Information System (INIS)

    Hall, J.F.; Molkenthin, J.P.; Prevey, P.S.; Pathania, R.S.

    1994-01-01

    Alloy 600 penetrations in several pressurized water reactors have experienced primary water stress corrosion cracking near the partial penetration J-welds between the Alloy 600 and the cladding on the inside diameter of the components. The microstructure and tensile properties indicated that the Alloy 600 was susceptible to primary water stress corrosion cracking (PWSCC) providing that a high tensile stress (applied + residual) was present. The residual stress distributions at the inside diameter surface and at different depths below the surface were measured in Alloy 600 nozzle and heater sleeve mockups. Surface residual stresses on the nozzle mockup ranged from -350 to +830 MPa. For the heater sleeve mockup, the surface residual stresses ranged from -330 to +525 MPa. In the areas of high tensile residual stress, for the most part, the residual stresses decreased with increasing depth below the surface. For the nozzle and heater sleeve mockups, the percent cold-world and yield strength as a function of depth were determined. (authors). 12 figs., 4 refs

  12. Diagnostics of atmospheric pressure air plasmas

    International Nuclear Information System (INIS)

    Laux, C.O.; Kruger, C.H.; Zare, R.N.

    2001-01-01

    Atmospheric pressure air plasmas are often thought to be in Local Thermodynamics Equilibrium (LTE) owing to fast interspecies collisional exchanges at high pressure. As will be seen here, this assumption cannot be relied upon, particularly with respect to optical diagnostics. Large velocity gradients in flowing plasmas and/or elevated electron temperatures created by electrical discharges can result in large departures from chemical and thermal equilibrium. Diagnostic techniques based on optical emission spectroscopy (OES) and Cavity Ring-Down Spectroscopy (CRDS) have been developed and applied at Stanford University to the investigation of atmospheric pressure plasmas under conditions ranging from thermal and chemical equilibrium to thermochemical nonequilibrium. This article presents a review of selected temperature and species concentration measurement techniques useful for the study of air and nitrogen plasmas

  13. IceBridge Paroscientific L0 Pressure Altimeter Raw Air Pressure, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA IceBridge Paroscientific L0 Pressure Altimeter Raw Air Pressure (IAPRS0) data set contains air pressure readings taken over Antarctica using the...

  14. IceBridge Paroscientific L0 Pressure Altimeter Raw Air Pressure

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA IceBridge Paroscientific L0 Pressure Altimeter Raw Air Pressure (IAPRS0) data set contains air pressure readings taken over Antarctica using the...

  15. Prosthetics socket that incorporates an air splint system focusing on dynamic interface pressure.

    Science.gov (United States)

    Razak, Nasrul Anuar Abd; Osman, Noor Azuan Abu; Gholizadeh, Hossein; Ali, Sadeeq

    2014-08-01

    The interface pressure between the residual limb and prosthetic socket has a significant effect on an amputee's satisfaction and comfort. This paper presents the design and performance of a new prosthetic socket that uses an air splint system. The air splint prosthetic socket system was implemented by combining the air splint with a pressure sensor that the transhumeral user controls through the use of a microcontroller. The modular construction of the system developed allows the FSR pressure sensors that are placed inside the air splint socket to determine the required size and fitting for the socket used. Fifteen transhumeral amputees participated in the study. The subject's dynamic pressure on the socket that's applied while wearing the air splint systems was recorded using F-socket transducers and microcontroller analysis. The values collected by the F-socket sensor for the air splint prosthetic socket system were determined accordingly by comparing the dynamic pressure applied using statically socket. The pressure volume of the air splint fluctuated and was recorded at an average of 38 kPa (2.5) to 41 kPa (1.3) over three hours. The air splint socket might reduce the pressure within the interface of residual limb. This is particularly important during the daily life activities and may reduce the pain and discomfort at the residual limb in comparison to the static socket. The potential development of an auto-adjusted socket that uses an air splint system as the prosthetic socket will be of interest to researchers involved in rehabilitation engineering, prosthetics and orthotics.

  16. Residual stresses in a weldment of pressure vessel steel

    International Nuclear Information System (INIS)

    Gott, K.E.

    1978-01-01

    A study was made of the distribution of residual stresses around a typical weld from a light water reactor pressure vessel by an X-ray double-exposure camera technique. So that the magnitude, sign, and distribution of the residual stresses were as similar as possible to those found in practice, a wide, full-thickness specimen of A533B Cl 1 steel containing a submerged-arc weld was stress-relief annealed. To obtain a three-dimensional distribution of the stresses the specimen was examined at different levels through the thickness. Following the removal of material by milling, the specimen surface was electropolished to free it from cold work. Corrections have been made to take into account specimen relaxation. To completely define the original stress system it is desirable also to measure the change in curvature on removing a layer of material. Unless this is done assumptions must be made which complicate the calculations unnecessarily. This became apparent after the experimental work was completed. In the centre of the plate the methods of correction which can be used are sensitive to errors in the measurements. The corrected results show that the dominant residual stress is perpendicular to the weld. It is positive at the surfaces and negative in the centre of the plate. The maximum value can reach the yield stress. The residual stresses in the weld metal can locally vary considerably: from 100 to 350N/mm 2 over a distance of 5mm. Such large variations have been found to coincide with the heat-affected zones of the individual weld runs. (author)

  17. Ambient-air ozonolysis of triglycerides in aged fingerprint residues.

    Science.gov (United States)

    Pleik, Stefanie; Spengler, Bernhard; Ram Bhandari, Dhaka; Luhn, Steven; Schäfer, Thomas; Urbach, Dieter; Kirsch, Dieter

    2018-02-26

    In forensic science, reconstructing the timing of events occurring during a criminal offense is of great importance. In some cases, the time when particular evidence was left on a crime scene is a critical matter. The ability to estimate the fingerprint age would raise the evidentiary value of fingerprints tremendously. For this purpose the most promising approach is the analysis of changes in the chemical compositions of fingerprint residues in the course of aging. The focus of our study is the identification of human specific compounds in fingerprint residues, characterized by a significant aging behavior that could analytically be used for the age determination of fingerprints in future. The first challenge is the sensitive detection of trace amounts of relevant human specific fingerprint compounds. Highly sensitive LC-MS methods were developed for the reliable structure identification of unsaturated triglycerides and their natural degradation products in order to proof the aging mechanism that takes place in fingerprint residues. Thus our results build the fundamental basis for further forensic method development and potential application in forensic investigation. Ozonolysis was found to be one of the major lipid degradation pathways in fingerprint residues in ambient air. High-resolution tandem mass spectrometry (HRMS 2 ) was carried out to identify the ozonolysis products (TG48:0-monoozonide) formed under exposure to the highly reactive ozone in atmospheric air. The obtained products were confirmed by matrix assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI). Despite several challenges and limitations in the age estimation of fingerprints, the identification of individual degradation products of specific unsaturated lipids in aged fingerprint samples represents a significant analytical progress, resulting in a strong increase in the validity of chemical analysis of fingerprints.

  18. Non-destructive residual pressure self-measurement method for the sensing chip of optical Fabry-Perot pressure sensor.

    Science.gov (United States)

    Wang, Xue; Wang, Shuang; Jiang, Junfeng; Liu, Kun; Zhang, Xuezhi; Xiao, Mengnan; Xiao, Hai; Liu, Tiegen

    2017-12-11

    We introduce a simple residual pressure self-measurement method for the Fabry-Perot (F-P) cavity of optical MEMS pressure sensor. No extra installation is required and the structure of the sensor is unchanged. In the method, the relationship between residual pressure and external pressure under the same diaphragm deflection condition at different temperatures is analyzed by using the deflection formula of the circular plate with clamped edges and the ideal gas law. Based on this, the residual pressure under the flat condition can be obtained by pressure scanning process and calculation process. We carried out the experiment to compare the residual pressures of two batches MEMS sensors fabricated by two kinds of bonding process. The measurement result indicates that our approach is reliable enough for the measurement.

  19. Prenatal air pollution exposure and newborn blood pressure

    NARCIS (Netherlands)

    van Rossem, Lenie; Rifas-Shiman, Sheryl L.; Melly, Steven J.; Kloog, Itai; Luttmann-Gibson, Heike; Zanobetti, Antonella; Coull, Brent A.; Schwartz, Joel D.; Mittleman, Murray A.; Oken, Emily; Gillman, Matthew W.; Koutrakis, Petros; Gold, Diane R.

    2015-01-01

    Background: Air pollution exposure has been associated with increased blood pressure in adults. oBjective: We examined associations of antenatal exposure to ambient air pollution with newborn systolic blood pressure (SBP). Methods: We studied 1,131 mother–infant pairs in a Boston, Massachusetts,

  20. Pressurized air ionization chamber with aluminium walls for radiometric dosimetry

    International Nuclear Information System (INIS)

    Rodrigues, R.G.S.; Pela, C.A.; Netto, T.G.

    1996-01-01

    A pressurized air ionization chamber with 23 cm 3 and aluminium walls is evaluated concerning its sensitiveness in low exposure rate. Considering conventional ionization chambers, this chamber shows a better performance since the air pressure of 2500 kPa minimizes the energy dependence to less than 5% between 40 and 1.250 keV

  1. Pressurized solid oxide fuel cell integral air accumular containment

    Science.gov (United States)

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

    2004-02-10

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

  2. On-site treatment and landfilling of MSWI air pollution control residues

    DEFF Research Database (Denmark)

    Lundtorp, Kasper; Jensen, Dorthe Lærke; Sørensen, Mette Abildgaard

    2003-01-01

    Air pollution control (APC) residues from municipal solid waste incineration (MSWI) are difficult to landfill due to substantial leaching of trace metals. An on-site pretreatment prior to landfilling of APC-residues was investigated in terms of bench-scale experiments with a semidry APC-residue a......Air pollution control (APC) residues from municipal solid waste incineration (MSWI) are difficult to landfill due to substantial leaching of trace metals. An on-site pretreatment prior to landfilling of APC-residues was investigated in terms of bench-scale experiments with a semidry APC...

  3. Drop impact on a solid surface at reduced air pressure

    Science.gov (United States)

    Langley, Kenneth; Li, E. Q.; Tian, Y. S.; Hicks, P. D.; Thoroddsen, S. T.

    2017-11-01

    When a drop approaches a solid surface at atmospheric pressure, the lubrication pressure within the air forms a dimple in the bottom of the drop resulting in the entrainment of an air disc upon impact. Reducing the ambient air pressure below atmospheric has been shown to suppress splashing and the compression of the intervening air could be significant on the air disc formation; however, to date there have been no experimental studies showing how the entrainment of the air disc is affected by reducing the ambient pressure. Using ultra-high-speed interferometry, at up to 5 Mfps, we investigate droplet impacts onto dry solid surfaces in reduced ambient air pressures with particular interest in what happens as rarified gas effects become important, i.e. when the thickness of the air layer is of the same magnitude as the mean free path of the air molecules. Experimental data will be presented showing novel phenomena and comparisons will be drawn with theoretical models from the literature.

  4. The Influence of Shaping Air Pressure of Pneumatic Spray Gun

    Science.gov (United States)

    Chen, Wenzhuo; Chen, Yan; Pan, Haiwei; Zhang, Weiming; Li, Bo

    2018-02-01

    The shaping air pressure is a very important parameter in the application of pneumatic spray gun, and studying its influence on spray flow field and film thickness distribution has practical values. In this paper, Euler-Lagrangian method is adopted to describe the two-phase spray flow of pneumatic painting process, and the air flow fields, spray patterns and dynamic film thickness distributions were obtained with the help of the computational fluid dynamics code—ANSYS Fluent. Results show that with the increase of the shaping air pressure, the air phase flow field spreads in the plane perpendicular to the shaping air hole plane, the spray pattern becomes narrower and flatter, and the width of the dynamic film increases with the reduced maximum value of the film thickness. But the film thickness distribution seems to change little with the shaping air pressure decreasing from 0.6bar to 0.9bar.

  5. Pressurized thermal and hydrothermal decomposition of algae, wood chip residue, and grape marc: A comparative study

    International Nuclear Information System (INIS)

    Subagyono, Dirgarini J.N.; Marshall, Marc; Jackson, W. Roy; Chaffee, Alan L.

    2015-01-01

    Pressurized thermal decomposition of two marine algae, Pinus radiata chip residue and grape marc using high temperature, high pressure reactions has been studied. The yields and composition of the products obtained from liquefactions under CO of a mixture of biomass and H 2 O (with or without catalyst) were compared with products from liquefaction of dry biomass under N 2 , at different temperatures, gas pressures and for CO runs, water to biomass ratios. Thermochemical reactions of algae produced significantly higher dichloromethane solubles and generally higher product yields to oil and asphaltene than Pinus radiata and grape marc under the reaction conditions used. Furthermore, the biofuels derived from algae contained significant concentrations of aliphatic hydrocarbons as opposed to those from radiata pine and grape marc which were richer in aromatic compounds. The possibility of air transport fuel production from algae thus appears to have considerable advantages over that from radiata pine and grape marc. - Highlights: • Liquefaction of algae gave more oil than that of Pinus radiata and grape marc. • Reactions under CO/H 2 O produced higher yields of oil than N 2 . • Water to biomass ratio had little effect on the yields. • Bio-oil from algae contained substantial amounts of aliphatic hydrocarbons. • Pinus radiata oil was low in N but high in O

  6. Accelerated crack growth, residual stress, and a cracked zinc coated pressure shell

    Science.gov (United States)

    Dittman, Daniel L.; Hampton, Roy W.; Nelson, Howard G.

    1987-01-01

    During a partial inspection of a 42 year old, operating, pressurized wind tunnel at NASA-Ames Research Center, a surface connected defect 114 in. long having an indicated depth of a 0.7 in. was detected. The pressure shell, constructed of a medium carbon steel, contains approximately 10 miles of welds and is cooled by flowing water over its zinc coated external surface. Metallurgical and fractographic analysis showed that the actual detect was 1.7 in. deep, and originated from an area of lack of weld penetration. Crack growth studies were performed on the shell material in the laboratory under various loading rates, hold times, and R-ratios with a simulated shell environment. The combination of zinc, water with electrolyte, and steel formed an electrolytic cell which resulted in an increase in cyclic crack growth rate by as much as 500 times over that observed in air. It was concluded that slow crack growth occurred in the pressure shell by a combination of stress corrosion cracking due to the welding residual stress and corrosion fatigue due to the cyclic operating stress.

  7. Evaluation of minimum residual pressure as design criterion for ...

    African Journals Online (AJOL)

    elled values for H relate to the MPH-design cri- teria. The focus of this study is on the pressure regions near or below 24 m. Customer behaviour indicative of low pressure. A 'too low' pressure head would result in numerous customer complaints. This study identifies numerous such areas. Despite this finding few customer ...

  8. Welding residual stress distributions for dissimilar metal nozzle butt welds in pressurized water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Soo; Kim, Ju Hee; Bae, Hong Yeol; OH, Chang Young; Kim, Yun Jae [Korea Univ., Seoul (Korea, Republic of); Lee, Kyungsoo [Korea Electric Power Research Institute, Daejeon (Korea, Republic of); Song, Tae Kwang [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2012-02-15

    In pressurized water nuclear reactors, dissimilar metal welds are susceptible to primary water stress corrosion cracking. To access this problem, accurate estimation of welding residual stresses is important. This paper provides general welding residual stress profiles in dissimilar metal nozzle butt welds using finite element analysis. By introducing a simplified shape for dissimilar metal nozzle butt welds, changes in the welding residual stress distribution can be seen using a geometry variable. Based on the results, a welding residual stress profile for dissimilar metal nozzle butt welds is proposed that modifies the existing welding residual stress profile for austenitic pipe butt welds.

  9. Residual Stress Estimation and Fatigue Life Prediction of an Autofrettaged Pressure Vessel

    Energy Technology Data Exchange (ETDEWEB)

    Song, Kyung Jin; Kim, Eun Kyum; Koh, Seung Kee [Kunsan Nat’l Univ., Kunsan (Korea, Republic of)

    2017-09-15

    Fatigue failure of an autofrettaged pressure vessel with a groove at the outside surface occurs owing to the fatigue crack initiation and propagation at the groove root. In order to predict the fatigue life of the autofrettaged pressure vessel, residual stresses in the autofrettaged pressure vessel were evaluated using the finite element method, and the fatigue properties of the pressure vessel steel were obtained from the fatigue tests. Fatigue life of a pressure vessel obtained through summation of the crack initiation and propagation lives was calculated to be 2,598 cycles for an 80% autofrettaged pressure vessel subjected to a pulsating internal pressure of 424 MPa.

  10. Security of bottle to fill in a high pressure air

    Science.gov (United States)

    Todic, M.; Latinovic, T.; Golubovic-Bugarski, V.; Majstorovic, A.

    2018-01-01

    Charging the bottle of high pressure air isolation devices is performed by a high-pressure compressor. The charging time is in function of the compressor capacity and the intensity of the nominal pressure of the air in the bottle. However, in accident situations this time is long and therefore high-pressure accumulators are used where the filling time of the bottle of isolation apparatus has been drastically reduced. Due to the short filling time of the bottle through the air flow, there is a thermodynamic load of bottle material that could endanger the safety of users and other participants in the area. It is therefore necessary to determine the critical parameters of the rapid charge and their intensity.

  11. The inclusion of weld residual stress in fracture margin assessments of embrittled nuclear reactor pressure vessels

    International Nuclear Information System (INIS)

    Dickson, T.L.; Bass, B.R.; McAfee, W.J.

    1998-01-01

    Analyses were performed to determine the impact of weld residual stresses in a reactor pressure vessel (RPV) on (1) the generation of pressure temperature (P-T) curves required for maintaining specified fracture prevention margins during nuclear plant startup and shutdown, and (2) the conditional probability of vessel failure due to pressurized thermal shock (PTS) loading. The through wall residual stress distribution in an axially oriented weld was derived using measurements taken from a shell segment of a canceled RPV and finite element thermal stress analyses. The P-T curve derived from the best estimate load analysis and a t / 8 deep flaw, based on K Ic , was less limiting than the one derived from the current methodology prescribed in the ASME Boiler and Pressure Vessel Code. The inclusion of the weld residual stresses increased the conditional probability of cleavage fracture due to PTS loading by a factor ranging from 2 to 4

  12. Calculation method for residual stress analysis of filament-wound spherical pressure vessels

    International Nuclear Information System (INIS)

    Knight, C.E. Jr.

    1976-01-01

    Filament wound spherical pressure vessels may be produced with very high performance factors. These performance factors are a calculation of contained pressure times enclosed volume divided by structure weight. A number of parameters are important in determining the level of performance achieved. One of these is the residual stress state in the fabricated unit. A significant level of an unfavorable residual stress state could seriously impair the performance of the vessel. Residual stresses are of more concern for vessels with relatively thick walls and/or vessels constructed with the highly anisotropic graphite or aramid fibers. A method is established for measuring these stresses. A theoretical model of the composite structure is required. Data collection procedures and techniques are developed. The data are reduced by means of the model and result in the residual stress analysis. The analysis method can be used in process parameter studies to establish the best fabrication procedures

  13. Partial alignment and measurement of residual dipolar couplings of proteins under high hydrostatic pressure

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Yinan; Wand, A. Joshua, E-mail: wand@mail.med.upenn.edu [University of Pennsylvania, Department of Biochemistry and Biophysics, Johnson Research Foundation (United States)

    2013-08-15

    High-pressure NMR spectroscopy has emerged as a complementary approach for investigating various structural and thermodynamic properties of macromolecules. Noticeably absent from the array of experimental restraints that have been employed to characterize protein structures at high hydrostatic pressure is the residual dipolar coupling, which requires the partial alignment of the macromolecule of interest. Here we examine five alignment media that are commonly used at ambient pressure for this purpose. We find that the spontaneous alignment of Pf1 phage, d(GpG) and a C12E5/n-hexnanol mixture in a magnetic field is preserved under high hydrostatic pressure. However, DMPC/DHPC bicelles and collagen gel are found to be unsuitable. Evidence is presented to demonstrate that pressure-induced structural changes can be identified using the residual dipolar coupling.

  14. Numerical simulation of probability of air migration from a pressurizer during reflux cooling

    International Nuclear Information System (INIS)

    Utanohara, Yoichi; Murase, Michio

    2009-01-01

    An accurate evaluation of the behaviors of non-condensable gases accumulated in the steam generator (SG) U-tubes is important to predict the performance of the reflux cooling, since the migration behaviors of such gases existing in the pressurizer to the SG U-tubes is not clarified yet. In this research, the steam and the air behaviors in the pressurizer was therefore analyzed numerically during reflux cooling using FLUENT 6.3.26 in order to investigate the possibility of air migration to the hot leg. In the present analysis, the pressurizer of ROSA-IV/LSTF experiment was employed as a calculation domain, since the experimental data of the loss of residual heat removal event during the mid-loop operation are available. Two stages were assumed; (1) Phase 1: latent heat accumulates in the wall of the pressurizer and is eventually released to the outside, (2) Phase 2: the wall heats up to the saturation temperature of the steam, and only heat loss to the outside occurs. The prediction indicates that in Phase 1 the air does not migrate into the surge line in neither laminar nor turbulent flow conditions, while in Phase 2 the air migrates into the hot leg only in the laminar flow condition. Judging from the previous experiment of axisymmetric free jet, the flow pattern in the pressurizer seems to be turbulent. In addition, a comparison of the analytical results of the fluid temperatures near the wall of pressurizer with ROSA-IV/LSTF experiment results suggests that the turbulent flow calculation results are more realistic. It has been therefore concluded that the turbulent calculation is more reasonable and the possibility of air migration into the hot leg is low. (author)

  15. Compressed air injection technique to standardize block injection pressures.

    Science.gov (United States)

    Tsui, Ban C H; Li, Lisa X Y; Pillay, Jennifer J

    2006-11-01

    Presently, no standardized technique exists to monitor injection pressures during peripheral nerve blocks. Our objective was to determine if a compressed air injection technique, using an in vitro model based on Boyle's law and typical regional anesthesia equipment, could consistently maintain injection pressures below a 1293 mmHg level associated with clinically significant nerve injury. Injection pressures for 20 and 30 mL syringes with various needle sizes (18G, 20G, 21G, 22G, and 24G) were measured in a closed system. A set volume of air was aspirated into a saline-filled syringe and then compressed and maintained at various percentages while pressure was measured. The needle was inserted into the injection port of a pressure sensor, which had attached extension tubing with an injection plug clamped "off". Using linear regression with all data points, the pressure value and 99% confidence interval (CI) at 50% air compression was estimated. The linearity of Boyle's law was demonstrated with a high correlation, r = 0.99, and a slope of 0.984 (99% CI: 0.967-1.001). The net pressure generated at 50% compression was estimated as 744.8 mmHg, with the 99% CI between 729.6 and 760.0 mmHg. The various syringe/needle combinations had similar results. By creating and maintaining syringe air compression at 50% or less, injection pressures will be substantially below the 1293 mmHg threshold considered to be an associated risk factor for clinically significant nerve injury. This technique may allow simple, real-time and objective monitoring during local anesthetic injections while inherently reducing injection speed.

  16. Predicted thermal superluminescence in low-pressure air

    OpenAIRE

    Aramyan, A. R.; Haroyan, K. P.; Galechyan, G. A.; Mangasaryan, N. R.; Nersisyan, H. B.

    2009-01-01

    It is shown that due to the dissociation of the molecular oxygen it is possible to obtain inverted population in low pressure air by heating. As a result of the quenching of the corresponding levels of the atomic oxygen the thermal superluminescent radiation is generated. It has been found that the threshold of the overpopulation is exceeded at the air temperature 2300-3000 K. Using this effect a possible mechanism for the generation of the flashes of the radiation in air observed on the airf...

  17. Exploration to generate atmospheric pressure glow discharge plasma in air

    Science.gov (United States)

    Wenzheng, LIU; Chuanlong, MA; Shuai, ZHAO; Xiaozhong, CHEN; Tahan, WANG; Luxiang, ZHAO; Zhiyi, LI; Jiangqi, NIU; Liying, ZHU; Maolin, CHAI

    2018-03-01

    Atmospheric pressure glow discharge (APGD) plasma in air has high application value. In this paper, the methods of generating APGD plasma in air are discussed, and the characteristics of dielectric barrier discharge (DBD) in non-uniform electric field are studied. It makes sure that APGD in air is formed by DBD in alternating current electric field with using the absorbing electron capacity of electret materials to provide initial electrons and to end the discharge progress. Through designing electric field to form two-dimensional space varying electric field and three-dimensional space varying electric field, the development of electron avalanches in air-gap is suppressed effectively and a large space of APGD plasma in air is generated. Further, through combining electrode structures, a large area of APGD plasma in air is generated. On the other hand, by using the method of increasing the density of initial electrons, millimeter-gap glow discharge in atmospheric pressure air is formed, and a maximum gap distance between electrodes is 8 mm. By using the APGD plasma surface treatment device composed of contact electrodes, the surface modification of high polymer materials such as aramid fiber and polyester are studied and good effect of modifications is obtained. The present paper provides references for the researchers of industrial applications of plasma.

  18. Pneumomediastinum following high pressure air injection to the hand.

    LENUS (Irish Health Repository)

    Kennedy, J

    2010-04-01

    We present the case of a patient who developed pneumomediastinum after high pressure air injection to the hand. To our knowledge this is the first reported case of pneumomediastinum where the gas injection site was the thenar eminence. Fortunately the patient recovered with conservative management.

  19. Pneumomediastinum following high pressure air injection to the hand.

    LENUS (Irish Health Repository)

    Kennedy, J

    2012-02-01

    We present the case of a patient who developed pneumomediastinum after high pressure air injection to the hand. To our knowledge this is the first reported case of pneumomediastinum where the gas injection site was the thenar eminence. Fortunately the patient recovered with conservative management.

  20. Improved fireman's compressed air breathing system pressure vessel development program

    Science.gov (United States)

    King, H. A.; Morris, E. E.

    1973-01-01

    Prototype high pressure glass filament-wound, aluminum-lined pressurant vessels suitable for use in a fireman's compressed air breathing system were designed, fabricated, and acceptance tested in order to demonstrate the feasibility of producing such high performance, lightweight units. The 4000 psi tanks have a 60 standard cubic foot (SCF) air capacity, and have a 6.5 inch diamter, 19 inch length, 415 inch volume, weigh 13 pounds when empty, and contain 33 percent more air than the current 45 SCF (2250 psi) steel units. The current steel 60 SCF (3000 psi) tanks weigh approximately twice as much as the prototype when empty, and are 2 inches, or 10 percent shorter. The prototype units also have non-rusting aluminum interiors, which removes the hazard of corrosion, the need for internal coatings, and the possibility of rust particles clogging the breathing system.

  1. Air and gas pockets in sewerage pressure mains.

    Science.gov (United States)

    Lubbers, C L; Clemens, F

    2005-01-01

    In The Netherlands, wastewater is collected in municipal areas and transported to large centralised WWTPs by means of an extensive system of pressure mains. Over the past decades these pressure mains did not receive much attention in terms of monitoring of performance or maintenance. For that reason, in practice their state of functioning is often not known. Failure of operation is only noticed when the capacity of the system proves to be insufficient to fulfil the minimum design capacity demand. A recent inventory showed that half of the pressure mains show an increased pressure loss for no directly obvious reason. Many causes may account for the reduction of the system's nominal capacity like an increased wall roughness, scaling or occurrence of free gas in the pipeline. The occurrence of free gas may be caused by degassing of dissolved (bio) gas or by air entrained at the pumps' inlet or at air valves. A research study is started that will focus on three main issues: The description of the gas-water phenomena in wastewater pressure mains with respect to transportation and dynamic hydraulic behaviour, A method to diagnose gas problems, and To overcome future problems by either applying remedial measures or improving the design of wastewater pressure systems. For this study, two experimental facilities are constructed, a small circuit for the study of multi-phase flow and a second, larger one for the research into diagnostic methods. This paper describes the preliminary results of the experiments in the multi-phase circuit.

  2. Residue Age and Attack Pressure Influence Efficacy of Insecticide Treatments Against Ambrosia Beetles (Coleoptera: Curculionidae).

    Science.gov (United States)

    Reding, Michael E; Ranger, Christopher M

    2018-02-09

    Management of ambrosia beetles in ornamental nurseries relies, in part, on insecticide treatments to prevent beetles from boring into trees. However, data on residual efficacy of commonly used pyrethroid insecticides is needed to gauge the duration that trees are protected during spring when peak beetle pressure occurs. Residual efficacy of bifenthrin and permethrin trunk sprays was examined in field trials which used trees injected with 10% ethanol to ensure host attack pressure. Permethrin consistently reduced attacks by Xylosandrus germanus (Blandford; Coleoptera: Curculionidae) and other ambrosia beetles for at least 4 wk, while efficacy of bifenthrin was inconsistent and lasted only about 10 d. Since previous studies demonstrated attacks are positively correlated with host ethanol emissions, we injected trees with 2.5, 5, and 10% ethanol to determine if residual efficacy was affected by attack pressure. Preventive treatments with bifenthrin reduced ambrosia beetle attacks at all concentrations of injected ethanol compared to non-sprayed controls. There was no interaction between attack pressure and insecticide treatment with respect to total attacks or attacks by X. germanus. However, increasing attack pressure did increase the probability of attacks on insecticide treated trees by X. germanus and other Scolytinae. Results from our current study will improve the ability of growers to make decisions on frequency of protective sprays, but residual efficacy of insecticide treatments may decline as attack pressure increases. Cultural practices should therefore maximize host vigor and minimize attack pressure associated with stress-induced ethanol emissions. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  3. Thermal and catalytic ASVAHL processes under hydrogen pressure for converting heavy crudes and conventional residues

    Energy Technology Data Exchange (ETDEWEB)

    Peries, J.P.; Quignard, A.; Farjon, C.; Laborde, M.

    This article describes the comparative performances of thermal ASVAHL processes (TERVAHL T, TERVAHL H, TERVAHL HC) and catalytic ASVAHL processes (HYVAHL F, HYVAHL C) for two types of processing: (1) degasolined Boscan crude (basis of studies for transportation feasibility), and (2) Safaniya vacuum residue (basis of studies for residue refining). The results reveal the importance of the amount of fixed hydrogen, which affects the conversion obtained and the quality of the residues. The introduction of a TERVAHL HC soluble catalyst or one in catalytic suspension (catalytic hydrovisbreaking) or the use of a supported catalyst (HYVAHL hydrotreatment) enhances the activation of hydrogen. The combination of cracking, polycondensation and hydrogen reactions together with the operating conditions (temperatures, residence time and pressure) are what will define the conversion limits for a given stability of residues.

  4. Generation of subnanosecond electron beams in air at atmospheric pressure

    Science.gov (United States)

    Kostyrya, I. D.; Tarasenko, V. F.; Baksht, E. Kh.; Burachenko, A. G.; Lomaev, M. I.; Rybka, D. V.

    2009-11-01

    Optimum conditions for the generation of runaway electron beams with maximum current amplitudes and densities in nanosecond pulsed discharges in air at atmospheric pressure are determined. A supershort avalanche electron beam (SAEB) with a current amplitude of ˜30 A, a current density of ˜20 A/cm2, and a pulse full width at half maximum (FWHM) of ˜100 ps has been observed behind the output foil of an air-filled diode. It is shown that the position of the SAEB current maximum relative to the voltage pulse front exhibits a time shift that varies when the small-size collector is moved over the foil surface.

  5. Long-term leaching from MSWI air-pollution-control residues: Leaching characterization and modeling

    DEFF Research Database (Denmark)

    Hyks, Jiri; Astrup, Thomas; Christensen, Thomas Højlund

    2009-01-01

    Long-term leaching of Ca, Fe, Mg, K, Na, S, Al, As, Ba, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Zn, Mo, Sb, Si, Sri, Sr, Ti, V, P, Cl, and dissolved organic carbon from two different municipal solid waste incineration (MSWI) air-pollution-control residues was monitored during 24 months of column...

  6. Geochemical modeling of leaching from MSWI air-pollution control residues

    NARCIS (Netherlands)

    Astrup, T.; Dijkstra, J.J.; Comans, R.N.J.; Sloot, van der H.A.; Christensen, T.H.

    2006-01-01

    This paper provides an improved understanding of the leaching behavior of waste incineration air-pollution-control (APC) residues in a long-term perspective. Leaching was investigated by a series of batch experiments reflecting leaching conditions after initial washout of highly soluble salts from

  7. Residual stress measurements in the dissimilar metal weld in pressurizer safety nozzle of nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Wagner R.C.; Rabello, Emerson G.; Mansur, Tanius R.; Scaldaferri, Denis H.B.; Paula, Raphael G., E-mail: wrcc@cdtn.br, E-mail: egr@cdtn.br, E-mail: tanius@cdtn.br, E-mail: dhbs@cdtn.br, E-mail: tanius@cdtn.br, E-mail: raphaelmecanica@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Souto, Joao P.R.S.; Carvalho Junior, Ideir T., E-mail: joprocha@yahoo.com.br, E-mail: ideir_engenharia@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Metalurgica

    2013-07-01

    Weld residual stresses have a large influence on the behavior of cracking that could possibly occur under normal operation of components. In case of an unfavorable environment, both stainless steel and nickel-based weld materials can be susceptible to stress-corrosion cracking (SCC). Stress corrosion cracks were found in dissimilar metal welds of some pressurized water reactor (PWR) nuclear plants. In the nuclear reactor primary circuit the presence of tensile residual stress and corrosive environment leads to so-called Primary Water Stress Corrosion Cracking (PWSCC). The PWSCC is a major safety concern in the nuclear power industry worldwide. PWSCC usually occurs on the inner surface of weld regions which come into contact with pressurized high temperature water coolant. However, it is very difficult to measure the residual stress on the inner surfaces of pipes or nozzles because of inaccessibility. A mock-up of weld parts of a pressurizer safety nozzle was fabricated. The mock-up was composed of three parts: an ASTM A508 C13 nozzle, an ASTM A276 F316L stainless steel safe-end, an AISI 316L stainless steel pipe and different filler metals of nickel alloy 82/182 and AISI 316L. This work presents the results of measurements of residual strain from the outer surface of the mock-up welded in base metals and filler metals by hole-drilling strain-gage method of stress relaxation. (author)

  8. Residual stress measurements in the dissimilar metal weld in pressurizer safety nozzle of nuclear power plant

    International Nuclear Information System (INIS)

    Campos, Wagner R.C.; Rabello, Emerson G.; Mansur, Tanius R.; Scaldaferri, Denis H.B.; Paula, Raphael G.; Souto, Joao P.R.S.; Carvalho Junior, Ideir T.

    2013-01-01

    Weld residual stresses have a large influence on the behavior of cracking that could possibly occur under normal operation of components. In case of an unfavorable environment, both stainless steel and nickel-based weld materials can be susceptible to stress-corrosion cracking (SCC). Stress corrosion cracks were found in dissimilar metal welds of some pressurized water reactor (PWR) nuclear plants. In the nuclear reactor primary circuit the presence of tensile residual stress and corrosive environment leads to so-called Primary Water Stress Corrosion Cracking (PWSCC). The PWSCC is a major safety concern in the nuclear power industry worldwide. PWSCC usually occurs on the inner surface of weld regions which come into contact with pressurized high temperature water coolant. However, it is very difficult to measure the residual stress on the inner surfaces of pipes or nozzles because of inaccessibility. A mock-up of weld parts of a pressurizer safety nozzle was fabricated. The mock-up was composed of three parts: an ASTM A508 C13 nozzle, an ASTM A276 F316L stainless steel safe-end, an AISI 316L stainless steel pipe and different filler metals of nickel alloy 82/182 and AISI 316L. This work presents the results of measurements of residual strain from the outer surface of the mock-up welded in base metals and filler metals by hole-drilling strain-gage method of stress relaxation. (author)

  9. Microcontrolled air-mattress for ulcer by pressure prevention

    International Nuclear Information System (INIS)

    Pasluosta, Cristian F; Fontana, Juan M; Beltramone, Diego A; Taborda, Ricardo A M

    2007-01-01

    An ulcer by pressure is produced when a constant pressure is exerted over the skin. This generates the collapse of the blood vessels and, therefore, a lack in the contribution of the necessary nutrients for the affected zone. As a consequence, the skin deteriorates, eventually causing an ulcer. In order to prevent it, a protocol must be applied to the patient, which is reflected on time and cost of treatment. There are some air mattresses available for this purpose, but whose performance does not fulfill all requirements. The prototype designed in our laboratory is based on the principle of the air mattress. Its objective is to improve on existing technologies and, due to an increased automation, reduce time dedication for personnel in charge of the patient. A clinical experience was made in the local Emergencies Hospital and also in an institution dedicated to aged patients care. In both cases, the results obtained and the comments from the personnel involved were favorable

  10. Investigation of the spatial variability and possible origins of wind-induced air pressure fluctuations responsible for pressure pumping

    Science.gov (United States)

    Mohr, Manuel; Laemmel, Thomas; Maier, Martin; Zeeman, Matthias; Longdoz, Bernard; Schindler, Dirk

    2017-04-01

    The exchange of greenhouse gases between the soil and the atmosphere is highly relevant for the climate of the Earth. Recent research suggests that wind-induced air pressure fluctuations can alter the soil gas transport and therefore soil gas efflux significantly. Using a newly developed method, we measured soil gas transport in situ in a well aerated forest soil. Results from these measurements showed that the commonly used soil gas diffusion coefficient is enhanced up to 30% during periods of strong wind-induced air pressure fluctuations. The air pressure fluctuations above the forest floor are only induced at high above-canopy wind speeds (> 5 m s-1) and lie in the frequency range 0.01-0.1 Hz. Moreover, the amplitudes of air pressure fluctuations in this frequency range show a clear quadratic dependence on mean above-canopy wind speed. However, the origin of these wind-induced pressure fluctuations is still unclear. Airflow measurements and high-precision air pressure measurements were conducted at three different vegetation-covered sites (conifer forest, deciduous forest, grassland) to investigate the spatial variability of dominant air pressure fluctuations, their origin and vegetation-dependent characteristics. At the conifer forest site, a vertical profile of air pressure fluctuations was measured and an array consisting of five pressure sensors were installed at the forest floor. At the grassland site, the air pressure measurements were compared with wind observations made by ground-based LIDAR and spatial temperature observations from a fibre-optic sensing network (ScaleX Campaign 2016). Preliminary results show that at all sites the amplitudes of relevant air pressure fluctuations increase with increasing wind speed. Data from the array measurements reveal that there are no time lags between the air pressure signals of different heights, but a time lag existed between the air pressure signals of the sensors distributed laterally on the forest floor

  11. AIR SEPARATION BY PRESSURE SWING ADSORPTION USING SUPERIOR ADSORBENTS

    Energy Technology Data Exchange (ETDEWEB)

    Ralph T. Yang

    2001-08-31

    Li-X zeolite (Si/Al = 1.0) is currently the best sorbent for use in the separation of air by adsorption processes. In particular, pressure swing adsorption (PSA) using zeolite sorbents is being increasingly used for air separation. Silver is also known to strongly affect the adsorptive properties of zeolites; and it is known that thermal vacuum dehydration of silver zeolites leads to the formation of silver clusters within the zeolite. In this work we have synthesized type X zeolites containing Ag and also varying mixtures of Li and Ag. In this project, we developed the Ag-containing zeolite as the best sorbent for air separation. We have also studied Co-ligand compounds as oxygen-selective sorbents. Syntheses, structural characterization and adsorption properties have been performed on all sorbents. The results are described in detail in 5 chapters.

  12. Active Sensing Air Pressure Using Differential Absorption Barometric Radar

    Science.gov (United States)

    Lin, B.

    2016-12-01

    Tropical storms and other severe weathers cause huge life losses and property damages and have major impacts on public safety and national security. Their observations and predictions need to be significantly improved. This effort tries to develop a feasible active microwave approach that measures surface air pressure, especially over open seas, from space using a Differential-absorption BArometric Radar (DiBAR) operating at 50-55 GHz O2 absorption band in order to constrain assimilated dynamic fields of numerical weather Prediction (NWP) models close to actual conditions. Air pressure is the most important variable that drives atmospheric dynamics, and currently can only be measured by limited in-situ observations over oceans. Even over land there is no uniform coverage of surface air pressure measurements. Analyses show that with the proposed space radar the errors in instantaneous (averaged) pressure estimates can be as low as 4mb ( 1mb) under all weather conditions. NASA Langley research team has made substantial progresses in advancing the DiBAR concept. The feasibility assessment clearly shows the potential of surface barometry using existing radar technologies. The team has also developed a DiBAR system design, fabricated a Prototype-DiBAR (P-DiBAR) for proof-of-concept, conducted laboratory, ground and airborne P-DiBAR tests. The flight test results are consistent with the instrumentation goals. The precision and accuracy of radar surface pressure measurements are within the range of the theoretical analysis of the DiBAR concept. Observational system simulation experiments for space DiBAR performance based on the existing DiBAR technology and capability show substantial improvements in tropical storm predictions, not only for the hurricane track and position but also for the hurricane intensity. DiBAR measurements will provide us an unprecedented level of the prediction and knowledge on global extreme weather and climate conditions.

  13. A coupled surface/subsurface flow model accounting for air entrapment and air pressure counterflow

    DEFF Research Database (Denmark)

    Delfs, Jens Olaf; Wang, Wenqing; Kalbacher, Thomas

    2013-01-01

    the mass exchange between compartments. A benchmark test, which is based on a classic experimental data set on infiltration excess (Horton) overland flow, identified a feedback mechanism between surface runoff and soil air pressures. Our study suggests that air compression in soils amplifies surface runoff......This work introduces the soil air system into integrated hydrology by simulating the flow processes and interactions of surface runoff, soil moisture and air in the shallow subsurface. The numerical model is formulated as a coupled system of partial differential equations for hydrostatic (diffusive...... wave) shallow flow and two-phase flow in a porous medium. The simultaneous mass transfer between the soil, overland, and atmosphere compartments is achieved by upgrading a fully established leakance concept for overland-soil liquid exchange to an air exchange flux between soil and atmosphere. In a new...

  14. Treatment of waste incinerator air-pollution-control residues with FeSO4: Concept and product characterization

    DEFF Research Database (Denmark)

    Lundtorp, Kasper; Jensen, Dorthe Lærke; Sørensen, Mette Abildgaard

    2002-01-01

    This paper describes a new concept for treatment of air- pollution-control (APC) residues from waste incineration and characterises the wastewater and stabilised residues generated by the process. The process involves mixing of APC-residues with a ferrous sulphate solution and subsequent oxidation...

  15. Residual stress measurements in laser clad repaired low pressure turbine blades for the power industry

    Energy Technology Data Exchange (ETDEWEB)

    Bendeich, P. [Australian Nuclear Science and Technology Organisation, Lucas Heights, Menai, NSW 2234 (Australia)]. E-mail: pbx@ansto.gov.au; Alam, N. [CSIRO Manufacturing Science and Technology, 32 Audley St., Woodville, SA 5011 (Australia); Brandt, M. [IRIS Swinburne University of Technology, 533-545 Burwood Rd., Hawthorne, Vic. 3122 (Australia); Carr, D. [Australian Nuclear Science and Technology Organisation, Lucas Heights, Menai, NSW 2234 (Australia); Short, K. [Australian Nuclear Science and Technology Organisation, Lucas Heights, Menai, NSW 2234 (Australia); Blevins, R. [Australian Nuclear Science and Technology Organisation, Lucas Heights, Menai, NSW 2234 (Australia); Curfs, C. [Australian Nuclear Science and Technology Organisation, Lucas Heights, Menai, NSW 2234 (Australia); Kirstein, O. [Australian Nuclear Science and Technology Organisation, Lucas Heights, Menai, NSW 2234 (Australia); Atkinson, G. [Australian Nuclear Science and Technology Organisation, Lucas Heights, Menai, NSW 2234 (Australia); Holden, T. [Northern Stress Technologies, 20, Pine Point Rd., Deep River, Ont., K0J 1P0 (Canada); Rogge, R. [National Research Council, Neutron Program for Materials Research, Chalk River Laboratories, Chalk River, Ont., KOJ 1JO (Canada)

    2006-11-10

    Low pressure turbine blades in power stations suffer from leading edge erosion damage due to water impingement. In an effort to extend the life of these blades, repair of the eroded regions has been proposed using laser cladding with Stellite material. However, the addition of Stellite results in residual stresses being generated in the parent metal due to contraction during cooling and differences in thermal expansion between the two materials. In this work test coupons and laser clad blades were examined for residual stresses using both the L3 diffractometer at the NRU reactor, Chalk River, Canada and the TASS strain scanner at ANSTO's HIFAR reactor, Lucas Heights, Australia. In addition XRD results were used to measure residual stresses on the surface of the blade to complement the neutron measurements. An FEA model of a simplified weld was used to explain some of the results.

  16. Management of residual pleural space and air leaks after major pulmonary resection.

    Science.gov (United States)

    Korasidis, Stylianos; Andreetti, Claudio; D'Andrilli, Antonio; Ibrahim, Mohsen; Ciccone, Annamaria; Poggi, Camilla; Siciliani, Alessandra; Rendina, Erino A

    2010-06-01

    Postoperative air leaks associated with residual pleural space is a well known complication contributing to prolong hospitalization. Many techniques have been proposed for the treatment of this complication. Between 1999 and 2009, 39 patients with air leaks associated with residual pleural space (>3 cm at chest X-ray) persisting over three days after major lung resection were enrolled in this study. All patients were treated with combined pneumoperitoneum and autologus blood patch. Pneumoperitoneum is obtained by the injection of 30 ml/kg of air under the diaphragm, using a Verres needle through the periumbilical area. The blood patch is obtained by instillating 100 ml of autologus blood through the chest tubes. No patients experienced complications related to the procedure. Obliteration of pleural space was obtained in all the patients at a maximum of 96 h postoperatively. Air leaks stopped in all the cases at a maximum of 144 h from surgery. Chest tube was removed 24 h after the air leakage disappearance. Our 10-year experience supports the early, combined use of pneumoperitoneum and blood patch whenever pleural space and air leaks present after major pulmonary resection. This approach may be recommended because of its easiness, safety, effectiveness, and the low costs.

  17. Pressure loss of the annular air-liquid flow in vertical tufes

    International Nuclear Information System (INIS)

    Schmal, M.; Cantalino, A.

    1976-01-01

    In this work the pressure loss of the annular air-liquid flow in vertical tubes has been determined. Correlations are presented for the frictional pressure drop. The dimensional analysis and the following fluid systems were used for this determination: air-water, air-alcohol solutions and air-water and surfactants [pt

  18. 30 CFR 56.13015 - Inspection of compressed-air receivers and other unfired pressure vessels.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Inspection of compressed-air receivers and... METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13015 Inspection of compressed-air receivers and other unfired pressure vessels. (a) Compressed-air receivers and other unfired pressure vessels...

  19. 30 CFR 57.13015 - Inspection of compressed-air receivers and other unfired pressure vessels.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Inspection of compressed-air receivers and...-UNDERGROUND METAL AND NONMETAL MINES Compressed Air and Boilers § 57.13015 Inspection of compressed-air receivers and other unfired pressure vessels. (a) Compressed-air receivers and other unfired pressure...

  20. Breakdown of air pockets in downwardly inclined sewerage pressure mains.

    Science.gov (United States)

    Lubbers, C L; Clemens, F H L R

    2006-01-01

    In the Netherlands, wastewater is collected in municipal areas and transported to centralised WWTPs by an extensive system of pressure mains. Over the last decades these pressure mains did not receive much attention in terms of monitoring of performance or maintenance. A recent inventory showed that half of the pressure mains show an increased pressure loss for no directly obvious reason. One of the many causes that account for the reduction of the flow capacity is the occurrence of free gas in the pipeline. During dry weather periods with low flow velocities, gas may accumulate at high points in the system. Once the velocity increases during storm weather flow, the air pockets may be broken down and transported to the end of the system. A research study is started focussing on the description of the gas-water phenomena in wastewater pressure mains with respect to transportation of gas. An experimental facility is constructed for the study of multi-phase flow. This paper describes the preliminary results of experiments on breakdown rates of gas pockets as a function of inclination angle and water flow rate. The results show an increasing breakdown rate with increasing inclination angle.

  1. Thermal Hydraulic Analysis of a Passive Residual Heat Removal System for an Integral Pressurized Water Reactor

    Directory of Open Access Journals (Sweden)

    Junli Gou

    2009-01-01

    Full Text Available A theoretical investigation on the thermal hydraulic characteristics of a new type of passive residual heat removal system (PRHRS, which is connected to the reactor coolant system via the secondary side of the steam generator, for an integral pressurized water reactor is presented in this paper. Three-interknited natural circulation loops are adopted by this PRHRS to remove the residual heat of the reactor core after a reactor trip. Based on the one-dimensional model and a simulation code (SCPRHRS, the transient behaviors of the PRHRS as well as the effects of the height difference between the steam generator and the heat exchanger and the heat transfer area of the heat exchanger are studied in detail. Through the calculation analysis, it is found that the calculated parameter variation trends are reasonable. The higher height difference between the steam generator and the residual heat exchanger and the larger heat transfer area of the residual heat exchanger are favorable to the passive residual heat removal system.

  2. 29 CFR 1915.172 - Portable air receivers and other unfired pressure vessels.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Portable air receivers and other unfired pressure vessels... SHIPYARD EMPLOYMENT Portable, Unfired Pressure Vessels, Drums and Containers, Other Than Ship's Equipment § 1915.172 Portable air receivers and other unfired pressure vessels. (a) Portable, unfired pressure...

  3. Microwave generation of stable atmospheric-pressure fireballs in air

    Science.gov (United States)

    Stephan, Karl D.

    2006-11-01

    The generation of stable buoyant fireballs in a microwave cavity in air at atmospheric pressure without the use of vaporized solids is described. These fireballs have some of the characteristics of ball lightning and resemble those reported by Dikhtyar and Jerby [Phys. Rev. Lett. 96, 045002 (2006)], although of a different color, and do not require the presence of molten or vaporized material. Mechanisms of microwave plasma formation and fluid dynamics can account for the observed behavior of the fireballs, which do not appear to meet the accepted definition of dusty plasmas in this case. Relevance to models of ball lightning and industrial applications are discussed.

  4. 49 CFR 393.51 - Warning signals, air pressure and vacuum gauges.

    Science.gov (United States)

    2010-10-01

    ... compressed air (air brakes) or a commercial motor vehicle towing a vehicle with service brakes activated by compressed air (air brakes) must be equipped with a pressure gauge and a warning signal. Trucks, truck... vehicles which were not subject to FMVSS No. 105 on the date of manufacture.) (c) Air brakes. A commercial...

  5. Assessment of long-term leaching from waste incineration air-pollution-control residues

    DEFF Research Database (Denmark)

    Astrup, Thomas; Mosbæk, Hans; Christensen, Thomas Højlund

    2006-01-01

    Assessment of long-term leaching from MSWI air-pollution-control (APC) residues is discussed with respect to use in environmental impact assessment, such as life-cycle assessment (LCA). A method was proposed for estimating leaching as a function of the liquid-to-solid (L/S) ratio in a long...... with the initial leaching. Only Al and Zn were found to show higher leachate concentrations at L/S ratios above 3000–5000l/kg. Carbonation generally prolonged the time needed for depletion from the solid residues; however, Ca and S were depleted faster than in the case of non-carbonated residues. This study shows...... leached with respect to L/S. The estimated long-term leaching from a semi-dry residue and a fly ash was compared with short-term leaching determined by batch tests at L/S 10l/kg, both carbonated and non-carbonated versions of the residues were investigated. Generally, very high L/S ratios above 2000l...

  6. Production of geopolymers using glass produced from DC plasma treatment of air pollution control (APC) residues.

    Science.gov (United States)

    Kourti, Ioanna; Rani, D Amutha; Deegan, D; Boccaccini, A R; Cheeseman, C R

    2010-04-15

    Air pollution control (APC) residues are the hazardous waste produced from cleaning gaseous emissions at energy-from-waste (EfW) facilities processing municipal solid waste (MSW). APC residues have been blended with glass-forming additives and treated using DC plasma technology to produce a high calcium alumino-silicate glass. This research has investigated the optimisation and properties of geopolymers prepared from this glass. Work has shown that high strength geopolymers can be formed and that the NaOH concentration of the activating solution significantly affects the properties. The broad particle size distribution of the APC residue glass used in these experiments results in a microstructure that contains unreacted glass particles included within a geopolymer binder phase. The high calcium content of APC residues may cause the formation of some amorphous calcium silicate hydrate (C-S-H) gel. A mix prepared with S/L=3.4, Si/Al=2.6 and [NaOH]=6M in the activating solution, produced high strength geopolymers with compressive strengths of approximately 130 MPa. This material had high density (2070 kg/m(3)) and low porosity. The research demonstrates for the first time that glass derived from DC plasma treatment of APC residues can be used to form high strength geopolymer-glass composites that have potential for use in a range of applications. 2009 Elsevier B.V. All rights reserved.

  7. Leaching Behavior of Circulating Fluidised Bed MSWI Air Pollution Control Residue in Washing Process

    Directory of Open Access Journals (Sweden)

    Zhiliang Chen

    2016-09-01

    Full Text Available In this study, air pollution control (APC residue is conducted with water washing process to reduce its chloride content. A novel electrical conductivily (EC measurement method is proposed to monitor the dynamic change of chloride concentrations in leachate as well as the chloride content of the residue. The method equally applies to various washing processes with different washing time, liquid/solid ratio and washing frequency. The results show that washing effectively extracts chloride salts from APC residues, including those from circulating fluidized bed (CFB municipal solid waste incineration (MSWI. The most appropriate liquid/solid ratio and washing time in the first washing are found to be around 4 L water per kg of APC residue and 30 min, respectively, and washing twice is required to obtain maximum dissolution. The pH value is the major controlling factor of the heavy metals speciation in leachate, while chloride concentration also affects the speciation of Cd. Water washing causes no perceptible transfer of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs from the APC residue to leachate. The chloride concentration is strongly related with electrical conductivity (EC, as well as with the concentrations of calcium, sodium and potassium of washing water. Their regression analyses specify that soluble chloride salts and EC could act as an indirect indicator to monitor the change of chloride concentration and remaining chloride content, thus, contributing to the selection of the optimal washing conditions.

  8. Recycling of air pollution control residues from municipal solid waste incineration into lightweight aggregates.

    Science.gov (United States)

    Quina, Margarida J; Bordado, João M; Quinta-Ferreira, Rosa M

    2014-02-01

    This work focuses on the assessment of technological properties and on the leaching behavior of lightweight aggregates (LWA) produced by incorporating different quantities of air pollution control (APC) residues from municipal solid waste (MSW) incineration. Currently this hazardous waste has been mostly landfilled after stabilization/solidification. The LWA were produced by pelletizing natural clay, APC residues as-received from incineration plant, or after a washing treatment, a small amount of oil and water. The pellets were fired in a laboratory chamber furnace over calcium carbonate. The main technological properties of the LWA were evaluated, mainly concerning morphology, bulk and particle densities, compressive strength, bloating index, water adsorption and porosity. Given that APC residues do not own expansive (bloating) properties, the incorporation into LWA is only possible in moderate quantities, such as 3% as received or 5% after pre-washing treatment. The leaching behavior of heavy metals from sintered LWA using water or acid solutions was investigated, and despite the low acid neutralization capacity of the synthetic aggregates, the released quantities were low over a wide pH range. In conclusion, after a washing pre-treatment and if the percentage of incorporation is low, these residues may be incorporated into LWA. However, the recycling of APC residues from MSW incineration into LWA does not revealed any technical advantage. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Air pressure waves from Mount St. Helens eruptions

    Energy Technology Data Exchange (ETDEWEB)

    Reed, J.W.

    1987-10-20

    Weather station barograph records as well as infrasonic recordings of the pressure wave from the Mount St. Helens eruption of May 18, 1980, have been used to estimate an equivalent explosion airblast yield for this event. Pressure amplitude versus distance patterns in various directions compared with patterns from other large explosions, such as atmospheric nuclear tests, the Krakatoa eruption, and the Tunguska comet impact, indicate that the wave came from an explosion equivalent of a few megatons of TNT. The extent of tree blowdown is considerably greater than could be expected from such an explosion, and the observed forest damage is attributed to outflow of volcanic material. The pressure-time signature obtained at Toledo, Washington, showed a long, 13-min duration negative phase as well as a second, hour-long compression phase, both probably caused by ejacta dynamics rather than standard explosion wave phenomenology. The peculiar audibility pattern, with the blast being heard only at ranges beyond about 100 km, is explicable by finite amplitude propagation effects. Near the source, compression was slow, taking more than a second but probably less than 5 s, so that it went unnoticed by human ears and susceptible buildings were not damaged. There was no damage as Toledo (54 km), where the recorded amplitude would have broken windows with a fast compression. An explanation is that wave emissions at high elevation angles traveled to the upper stratosphere, where low ambient air pressures caused this energetic pressure oscillation to form a shock wave with rapid, nearly instantaneous compression. Atmospheric refraction then returned part of this wave to ground level at long ranges, where the fast compressions were clearly audible. copyright American Geophysical Union 1987

  10. Repair weld induced residual stresses in thick-walled steel pressure vessels

    Energy Technology Data Exchange (ETDEWEB)

    Smith, G.C.; Holz, P.P.

    1978-06-01

    If a flaw requiring corrective action were to be found in an operating nuclear pressure vessel, there would be considerable safety and economic implications. Should such a flaw be found, one possible corrective action would be an in situ repair weld. A repair of this type would presumably involve grinding away material in a region encompassing the flaw and then filling the resulting cavity with weld metal. Thermal stress relieving under those conditions could lead to serious difficulties associated with thermal expansion and warpage and would therefore most likely be avoided. Such a departure from normal procedure raises questions relating to residual stresses and material toughness levels which would have to be assessed before a repair could be recommended or approved. The residual stress measurements reported are intended to provide baseline information to aid in an assessment should such a repair ever have to be seriously considered.

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

    KAUST Repository

    He, Weihua

    2016-09-30

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

  12. The prediction of reliability and residual life of reactor pressure components

    International Nuclear Information System (INIS)

    Nemec, J.; Antalovsky, S.

    1978-01-01

    The paper deals with the problem of PWR pressure components reliability and residual life evaluation and prediction. A physical model of damage cumulation which serves as a theoretical basis for all considerations presents two major aspects. The first one describes the dependence of the degree of damage in the crack leading-edge in pressure components on the reactor system load-time history, i.e. on the number of transient loads. Both stages, fatigue crack initiation and growth through the wall until the critical length is reached, are investigated. The crack is supposed to initiate at the flaws in a strength weld joint or in the bimetallic weld of the base ferritic steel and the austenitic stainless overlay cladding. The growth rates of developed cracks are analysed in respect to different load-time histories. Important cyclic properties of some steels are derived from the low-cycle fatigue theory. The second aspect is the load-time history-dependent process of precipitation, deformation and radiation aging, characterized entirely by the critical crack-length value mentioned above. The fracture point, defined by the equation ''crack-length=critical value'' and hence the residual life, can be evaluated using this model and verified by in-service inspection. The physical model described is randomized by considering all the parameters of the model as random. Monte Carlo methods are applied and fatigue crack initiation and growth is simulated. This permits evaluation of the reliability and residual life of the component. The distributions of material and load-time history parameters are needed for such simulation. Both the deterministic and computer-simulated probabilistic predictions of reliability and residual life are verified by prior-to-failure sequential testing of data coming from in-service NDT periodical inspections. (author)

  13. Effects of pressure on syngas/air turbulent nonpremixed flames

    Science.gov (United States)

    Lee, Bok Jik; Im, Hong G.; Ciottoli, Pietro Paolo; Valorani, Mauro

    2016-11-01

    Large eddy simulations (LES) of turbulent non-premixed jet flames were conducted to investigate the effects of pressure on the syngas/air flame behavior. The software to solve the reactive Navier-Stokes equations was developed based on the OpenFOAM framework, using the YSLFM library for the flamelet-based chemical closure. The flamelet tabulation is obtained by means of an in-house code designed to solve unsteady flamelets of both ideal and real fluid mixtures. The validation of the numerical setup is attained by comparison of the numerical results with the Sandia/ETH-Zurich experimental database of the CO/H2/N2 non-premixed, unconfined, turbulent jet flame, referred to as "Flame A". Two additional simulations, at pressure conditions of 2 and 5 atm, are compared and analyzed to unravel computational and scientific challenges in characterizing turbulent flames at high pressures. A set of flamelet solutions, representative of the jet flames under review, are analyzed following a CSP approach. In particular, the Tangential Stretching Rate (TSR), representing the reciprocal of the most energetic time scale associated with the chemical source term, and its extension to reaction-diffusion systems (extended TSR), are adopted.

  14. Slow and pressurized co-pyrolysis of coal and agricultural residues

    International Nuclear Information System (INIS)

    Aboyade, Akinwale O.; Carrier, Marion; Meyer, Edson L.; Knoetze, Hansie; Görgens, Johann F.

    2013-01-01

    Highlights: ► Evaluation of co-pyrolysis of coal and biomass in pressurized packed bed reactor. ► Relative influence of coal–biomass mix ratio, temperature and pressure also investigated. ► Results show significant synergy or chemical interactions in the vapor phase. ► Synergistic interactions did not influence distribution of lumped solid liquid and gas products. - Abstract: The distribution of products from the slow heating rate pyrolysis of coal, corn residues (cobs and stover), sugarcane bagasse and their blends were investigated by slow pressurized pyrolysis in a packed bed reactor. A factorial experimental design was implemented to establish the relative significance of coal–biomass mix ratio, temperature and pressure on product distribution. Results showed that the yield and composition of tar and other volatile products were mostly influenced by mix ratio, while temperature and pressure had a low to negligible significance under the range of conditions investigated. Analysis of the composition of condensates and gas products obtained showed that there was significant synergy or chemical interactions in the vapor phase during co-pyrolysis of coal and biomass. However, the interactions did not significantly affect the relative distribution of the lumped solid, liquid and gas products obtained from the blends, beyond what would be expected assuming additive behavior from the contributing fuels.

  15. Environmental pressure group strength and air pollution. An empirical analysis

    International Nuclear Information System (INIS)

    Binder, Seth; Neumayer, Eric

    2005-01-01

    There is an established theoretical and empirical case-study literature arguing that environmental pressure groups have a real impact on pollution levels. Our original contribution to this literature is to provide the first systematic quantitative test of the strength of environmental non-governmental organizations (ENGOs) on air pollution levels. We find that ENGO strength exerts a statistically significant impact on sulfur dioxide, smoke and heavy particulates concentration levels in a cross-country time-series regression analysis. This result holds true both for ordinary least squares and random-effects estimation. It is robust to controlling for the potential endogeneity of ENGO strength with the help of instrumental variables. The effect is also substantively important. Strengthening ENGOs represents an important strategy by which aid donors, foundations, international organizations and other stakeholders can try to achieve lower pollution levels around the world

  16. Assessment of the advantages of a residual heat removal system inside the reactor pressure vessel

    Energy Technology Data Exchange (ETDEWEB)

    Gautier, G.M. [Commissariat a l`Energie Atomique, Saint-Paul-Lez-Durance (France)

    1995-09-01

    In the framework of research on diversified means for removing residual heat from pressurized water reactors, the CEA is studying a passive system called RRP (Refroidissement du Reacteur au Primaire, or primary circuit cooling system). This system consists of integrated heat-exchangers and a layout of the internal structures so as to obtain convection from the primary circuit inside the vessel, whatever the state of the loops. This system is operational for all primary circuit temperatures and pressures, as well as for a wide range of conditions: such as independent from the state of the loops, low volume of water in the primary circuit, compatibility with either a passive or an active operation mode, and compatibility with any other decay heat removal systems. This paper presents an evaluation of the performance of the RRP system in the event of a small primary circuit break in a totally passive operation mode without the intervention of any another system. The results of this evaluation show the potential interest of such a system: a clear increase of the time-delay for the implementation of a low pressure safety injection system and no need for the use of a high pressure safety injection system.

  17. BOREAS AFM-05 Level-2 Upper Air Network Standard Pressure Level Data

    Data.gov (United States)

    National Aeronautics and Space Administration — Basic upper-air parameters interpolated at 0.5 kiloPascal increments of atmospheric pressure from the network of upper-air stations during the 1993, 1994, and 1996...

  18. BOREAS AFM-05 Level-2 Upper Air Network Standard Pressure Level Data

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: Basic upper-air parameters interpolated at 0.5 kiloPascal increments of atmospheric pressure from the network of upper-air stations during the 1993, 1994,...

  19. Residual stress measurement inside a dissimilar metal weld mock-up of the pressurizer safety and relief nozzle

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Wagner R.C.; Rabello, Emerson G.; Silva, Luiz L.; Mansur, Tanius R., E-mail: wrcc@cdtn.br, E-mail: egr@cdtn.br, E-mail: silvall@cdtn.br, E-mail: tanius@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte (Brazil). Servico de Integridade Estrutural; Martins, Ketsia S., E-mail: ketshinoda@hotmail.com [Universidade Federal de Minas Gerais (UFMG), Nelo Horizonte (Brazil). Departamento de Engenharia Metalurgica

    2015-07-01

    Residual stresses are present in materials or structural component in the absence of external loads or changes in temperatures. The most common causes of residual stresses being present are the manufacturing or assembling processes. All manufacturing processes, such as casting, welding, machining, molding, heat treatment, among others, introduces residual stresses into the manufactured object. The residual stresses effects could be beneficial or detrimental, depending on its distribution related to the component or structure, its load service and if it is compressive or tensile. In this work, the residual strains and stresses inside a mock-up that simulates the safety and relief nozzle of Angra 1 Nuclear Power Plant pressurizer were studied. The current paper presents a blind hole-drilling method residual stress measurements both at the inner surface of dissimilar metal welds of dissimilar metal weld nozzle mock-up. (author)

  20. Impact of forest biomass residues to the energy supply chain on regional air quality.

    Science.gov (United States)

    Rafael, S; Tarelho, L; Monteiro, A; Sá, E; Miranda, A I; Borrego, C; Lopes, M

    2015-02-01

    The increase of the share of renewable energy in Portugal can be met from different sources, of which forest biomass residues (FBR) can play a main role. Taking into account the demand for information about the strategy of FBR to energy, and its implications on the Portuguese climate policy, the impact of energy conversion of FBR on air quality is evaluated. Three emission scenarios were defined and a numerical air quality model was selected to perform this evaluation. The results reveal that the biomass thermal plants contribute to an increment of the pollutant concentrations in the atmosphere, however restricted to the surrounding areas of the thermal plants, and most significant for NO₂ and O₃. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. [Aerodynamics study on pressure changes inside pressure-type whole-body plethysmograph produced by flowing air].

    Science.gov (United States)

    Xu, Wei-Hua; Shen, Hua-Hao

    2010-02-25

    When using pressure-type plethysmography to test lung function of rodents, calculation of lung volume is always based on Boyle's law. The precondition of Boyle's law is that perfect air is static. However, air in the chamber is flowing continuously when a rodent breathes inside the chamber. Therefore, Boyle's law, a principle of air statics, may not be appropriate for measuring pressure changes of flowing air. In this study, we deduced equations for pressure changes inside pressure-type plethysmograph and then designed three experiments to testify the theoretic deduction. The results of theoretic deduction indicated that increased pressure was generated from two sources: one was based on Boyle's law, and the other was based on the law of conservation of momentum. In the first experiment, after injecting 0.1 mL, 0.2 mL, 0.4 mL of air into the plethysmograph, the pressure inside the chamber increased sharply to a peak value, then promptly decreased to horizontal pressure. Peak values were significantly higher than the horizontal values (P<0.001). This observation revealed that flowing air made an extra effect on air pressure in the plethysmograph. In the second experiment, the same volume of air was injected into the plethysmograph at different frequencies (0, 0.5, 1, 2, 3 Hz) and pressure changes inside were measured. The results showed that, with increasing frequencies, the pressure changes in the chamber became significantly higher (P<0.001). In the third experiment, small animal ventilator and pipette were used to make two types of airflow with different functions of time. The pressure changes produced by the ventilator were significantly greater than those produced by the pipette (P<0.001). Based on the data obtained, we draw the conclusion that, the flow of air plays a role in pressure changes inside the plethysmograph, and the faster the airflow is, the higher the pressure changes reach. Furthermore, the type of airflow also influences the pressure changes.

  2. Residual heat removal pump and low pressure safety injection pump retrofit program

    International Nuclear Information System (INIS)

    Dudiak, J.G.; McKenna, J.M.

    1992-01-01

    Residual Heat Removal (RHR) and low pressure safety injection (LPSI) pumps installed in pressurized water-to-reactor power plants are used to provide low-head safety injection in the event of loss of coolant in the reactor coolant system. Because these pumps are subjected to rather severe temperature and pressure transients, the majority of pumps installed in the RHR service are vertical pumps with a single stage impeller. Typically the pump impeller is mounted on an extended motor shaft (close-coupled configuration) and a mechanical seal is employed at the pump end of the shaft. Traditionally RHR and LPSI pumps have been a significant maintenance item for many utilities. Periodic mechanical seal of motor bearing replacement often is considered routine maintenance. The closed-coupled pump design requires disassembly of the casing cover from the lower pump casing while performing these routine maintenance tasks. This paper introduces a design modification developed to convert the close-coupled RHR and LPSI pumps to a coupled configuration

  3. Pressure ulcer incidence and progression in critically ill subjects: influence of low air loss mattress versus a powered air pressure redistribution mattress.

    Science.gov (United States)

    Black, Joyce; Berke, Christine; Urzendowski, Gail

    2012-01-01

    The primary objective of this study was to compare facility-acquired pressure ulcer incidence and progression of pressure ulcers present on admission in critically ill patients, using 2 different support surfaces. We completed a comparison cohort study in a surgical intensive care unit (ICU). The study setting was a 12-bed cardiovascular ICU in a university-based hospital in the Midwestern United States. The sample comprised 52 critically ill patients; 31 were placed on low air loss weight-based pressure redistribution-microclimate management system beds and 21 were placed on integrated powered air pressure redistribution beds. Prior to the start of the study, 5 low airloss beds were placed in open rooms in the cardiovascular surgical ICU. Inclusion criteria were anticipated ICU stay of 3 days, and patients did not receive a speciality bed for pulmonary or wound issues. Initial assessment of the patients included risk assessment and prior events that would increase risk for pressure ulcer development such as extended time in operating room, along with skin assessment for existing pressure ulcers. Subjects in both groups had ongoing skin assessment every 3 to 4 days and a subjective evaluation of heel elevation and turning or repositioning by the researcher. Data were collected until the subjects were dismissed from the ICU. Patients admitted to the unit were assigned to open rooms following the usual protocols. The mean length of stay was 7.0 days, with an 8.1-day length of stay for subjects on "low air loss with microclimate management" beds (LAL-MCM) and 6.6 days on the integrated power pressure air redistribution (IP-AR) beds (P = NS). The incidence of pressure ulcers on the buttocks, sacrum, or coccyx was 0% (0/31) on the low air loss bed and 18% (4/21) on the IP-AR bed (P = .046). Five subjects had 6 pressure ulcers on admission. Two pressure ulcers on 2 patients worsened on the integrated power air redistribution beds, which required specialty bed rental

  4. Properties of sintered glass-ceramics prepared from plasma vitrified air pollution control residues.

    Science.gov (United States)

    Roether, J A; Daniel, D J; Rani, D Amutha; Deegan, D E; Cheeseman, C R; Boccaccini, A R

    2010-01-15

    Air pollution control (APC) residues, obtained from a major UK energy from waste (EfW) plant, processing municipal solid waste, have been blended with silica and alumina and melted using DC plasma arc technology. The glass produced was crushed, milled, uni-axially pressed and sintered at temperatures between 750 and 1150 degrees C, and the glass-ceramics formed were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Mechanical properties assessed included Vickers's hardness, flexural strength, Young's modulus and thermal shock resistance. The optimum sintering temperature was found to be 950 degrees C. This produced a glass-ceramic with high density (approximately 2.58 g/cm(3)), minimum water absorption (approximately 2%) and relatively high mechanical strength (approximately 81+/-4 MPa). Thermal shock testing showed that 950 degrees C sintered samples could withstand a 700 degrees C quench in water without micro-cracking. The research demonstrates that glass-ceramics can be readily formed from DC plasma treated APC residues and that these have comparable properties to marble and porcelain. This novel approach represents a technically and commercially viable treatment option for APC residues that allow the beneficial reuse of this problematic waste.

  5. DDT in fuel air mixtures at elevated temperatures and pressures

    Science.gov (United States)

    Card, J.; Rival, D.; Ciccarelli, G.

    2005-11-01

    An experimental study was carried out to investigate flame acceleration and deflagration-to-detonation transition (DDT) in fuel air mixtures at initial temperatures up to 573 K and pressures up to 2 atm. The fuels investigated include hydrogen, ethylene, acetylene and JP-10 aviation fuel. The experiments were performed in a 3.1-m long, 10-cm inner-diameter heated detonation tube equipped with equally spaced orifice plates. Ionization probes were used to measure the flame time-of-arrival from which the average flame velocity versus propagation distance could be obtained. The DDT composition limits and the distance required for the flame to transition to detonation were obtained from this flame velocity data. The correlation developed by Veser et al. (run-up distance to supersonic flames in obstacle-laden tubes. In the proceedings of the 4th International Symposium on Hazards, Prevention and Mitigation of Industrial Explosions, France (2002)) for the flame choking distance proved to work very well for correlating the detonation run-up distance measured in the present study. The only exception was for the hydrogen air data at elevated initial temperatures which tended to fall outside the scatter of the hydrocarbon mixture data. The DDT limits obtained at room temperature were found to follow the classical d/λ = 1 correlation, where d is the orifice plate diameter and λ is the detonation cell size. Deviations found for the high-temperature data could be attributed to the one-dimensional ZND detonation structure model used to predict the detonation cell size for the DDT limit mixtures. This simple model was used in place of actual experimental data not currently available.

  6. Study of short atmospheric pressure dc glow microdischarge in air

    Science.gov (United States)

    Kudryavtsev, Anatoly; Bogdanov, Eugene; Chirtsov, Alexander; Emelin, Sergey

    2011-10-01

    The results of experiments and simulations of short (without positive column) atmospheric pressure dc glow discharge in air are presented. We used metal steel electrodes with a gap of 5-100 microns. The experimental voltage-current characteristic's (VAC) have a constant or slightly increasing form at low gap. The most stable microdischarges were burning with a flat cathode and rounded anode, when the length of the discharge is automatically established near the minimum of the Paschen curve by changing their binding on the anode. In this case microdischarge was stable and it had growing VAC. For simulations we used 2D fluid model with kinetic description of electrons. We solved the balance equations for the vibrationally- and the electronically-excited states of a nitrogen and oxygen molecules; nitrogen and oxygen atoms; ozone molecule; and different nitrogen and oxygen ions with different plasmochemical reactions between them. Simulations predicted the main regions of the dc glow discharges including cathode and anode sheath and plasma of negative glow, Faraday dark space and transition region. Gas heating plays an important role in shaping the discharge profiles. The results of experiments and simulations of short (without positive column) atmospheric pressure dc glow discharge in air are presented. We used metal steel electrodes with a gap of 5-100 microns. The experimental voltage-current characteristic's (VAC) have a constant or slightly increasing form at low gap. The most stable microdischarges were burning with a flat cathode and rounded anode, when the length of the discharge is automatically established near the minimum of the Paschen curve by changing their binding on the anode. In this case microdischarge was stable and it had growing VAC. For simulations we used 2D fluid model with kinetic description of electrons. We solved the balance equations for the vibrationally- and the electronically-excited states of a nitrogen and oxygen molecules; nitrogen

  7. Double Contact During Drop Impact on a Solid Under Reduced Air Pressure

    KAUST Repository

    Li, Erqiang

    2017-11-20

    Drops impacting on solid surfaces entrap small bubbles under their centers, owing to the lubrication pressure which builds up in the thin intervening air layer. We use ultrahigh-speed interference imaging, at 5 Mfps, to investigate how this air layer changes when the ambient air pressure is reduced below atmospheric. Both the radius and the thickness of the air disc become smaller with reduced air pressure. Furthermore, we find the radial extent of the air disc bifurcates, when the compressibility parameter exceeds similar to 25. This bifurcation is also imprinted onto some of the impacts, as a double contact. In addition to the central air disc inside the first ring contact, this is immediately followed by a second ring contact, which entraps an outer toroidal strip of air, which contracts into a ring of bubbles. We find this occurs in a regime where Navier slip, due to rarefied gas effects, enhances the rate gas can escape from the path of the droplet.

  8. Double Contact During Drop Impact on a Solid Under Reduced Air Pressure

    Science.gov (United States)

    Li, Er Qiang; Langley, Kenneth R.; Tian, Yuan Si; Hicks, Peter D.; Thoroddsen, Sigurdur T.

    2017-11-01

    Drops impacting on solid surfaces entrap small bubbles under their centers, owing to the lubrication pressure which builds up in the thin intervening air layer. We use ultrahigh-speed interference imaging, at 5 Mfps, to investigate how this air layer changes when the ambient air pressure is reduced below atmospheric. Both the radius and the thickness of the air disc become smaller with reduced air pressure. Furthermore, we find the radial extent of the air disc bifurcates, when the compressibility parameter exceeds ˜25 . This bifurcation is also imprinted onto some of the impacts, as a double contact. In addition to the central air disc inside the first ring contact, this is immediately followed by a second ring contact, which entraps an outer toroidal strip of air, which contracts into a ring of bubbles. We find this occurs in a regime where Navier slip, due to rarefied gas effects, enhances the rate gas can escape from the path of the droplet.

  9. The potential dermal irritating effect of residual (meth)acrylic monomers in pressure sensitive adhesive tapes.

    Science.gov (United States)

    Tokumura, Fumio; Matsui, Tetsuya; Suzuki, Yasuko; Sado, Masashi; Taniguchi, Masaharu; Kobayashi, Ichiro; Kamiyama, Masashi; Suda, Shin; Nakamura, Atsushi; Yamazaki, Yuhiro; Yamori, Akira; Igarashi, Ryosuke; Kawai, Jun; Oka, Keiji

    2010-01-01

    It is generally thought that residual unpolymerized (meth)acrylic monomers commonly found in pressure sensitive adhesive tapes for medical use may cause dermal irritation, but a systematic study has never been carried out. Therefore, we assessed the potential dermal irritating effect of residual (meth)acrylic monomers. We studied seven acrylic monomers, acrylic acid (AA), methyl acrylate (MA), ethyl acrylate (EA), n-butyl acrylate (n-BA), n-hexyl acrylate (n-HA), 2-ethylhexyl acrylate (2-EHA) and 2-hydroxyethyl acrylate (HEA), as well as three methacrylic monomers, methacrylic acid (MAA), methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (2-HEMA). We first examined their cytotoxic effect on a cultured dermis model using the MTT method to determine their EC(50) and then performed a primary irritation test in rabbits using the monomers at three different concentrations (i.e., EC(50) , one-tenth EC(50) and 10 times EC(50)). Marked variations were found in cytotoxic and dermal irritating activities among the (meth)acrylic monomers tested. HEA exhibited the most potent dermal irritation having the lowest erythema dose (the concentration which gives a primary dermal irritation index of 1.00) of 460 ppm. But the other monomers exhibited less potent dermal irritation (lowest erythema doses > or =1000 ppm). For the monomers, significant correlation was found between cytotoxic activity and in vivo dermal irritating activity. Our results show that residual unpolymerized (meth)acrylic monomers in adhesive tapes are unlikely to induce skin irritation except for HEA. This study also suggests that cultured skin models are extremely useful as a screening method for chemical substances that could potentially cause dermal irritating activity.

  10. Air Toxics Emissions from Open Burning of Crop Residues in Southeast Asia

    Science.gov (United States)

    KIM Oanh, N. T.; Permadi, D. A.; Hopke, P. K.; Smith, K. R.; Nguyet, D. A.

    2016-12-01

    Agricultural crops production in Southeast Asia (SEA) increases annually to meet domestic consumption of growing population and also for export. Crop residue open burning (CROB) is commonly practiced by farmers to quickly dispose of huge amounts of the agricultural waste, such as rice straw, generated after each crop cycle. This CROB activity emits various toxic air pollutants as well as short-lived climate pollutants such as black carbon particles. Our study focused on quantifying the 2015 annual emissions of semi-volatile organic compounds including polycyclic aromatic hydrocarbons (PAHs), dioxins/furans (PCDD/PCDF), organochlorine pesticides (OCP), along with other conventional trace gases, particulate matter, and greenhouse gases from CROB in 10 major agricultural crop producing SEA countries. Crop production statistics and current field OB practices were gathered from our primary surveys and relevant secondary data sources. Emission factors for rice straw and maize residue burning were taken mainly from our measurements in Thailand while for other crops relevant published data were used. The best emission estimates of air toxics from CROB in SEA were 112 g-TEQ/yr of PCDD/PCDF, 33 t/yr of OCP, and 25 Gg/yr of total PAH of which the well-known carcinogenic benzo[a]pyrene was 0.3 Gg/yr. The CROB of rice production had the highest shares of emissions (33-95%) among considered 8 crop types. Indonesia was the top contributor to the total SEA emissions (30-45%) followed by Vietnam (16-26%), Thailand (6-22%) and Myanmar (5-18%). The spatial distributions of emissions, 0.1º x 0.1º, for each specie were prepared using MODIS land cover data. Temporally, higher emissions were observed in the harvesting months of the main rice crops. This emissions database can be used in regional air quality modeling studies to assess the impacts of CROB activity and to promote non-open burning alternatives.

  11. [Studies on the operative factors affecting the reduction of chronic subdural hematoma, with special reference to the residual air in the hematoma cavity].

    Science.gov (United States)

    Nagata, K; Asano, T; Basugi, N; Tango, T; Takakura, K

    1989-01-01

    The authors previously reported the effect of preoperative factors affecting the reduction of chronic subdural hematoma. In this report, we evaluated some operative factors, including operative methods, duration of drainage, and residual air volume, with newly developed CT volumetry technique. As described before, the hematoma volume reduces exponentially. An exponential curve was fitted to the reduction curve using the least square method, and its half reduction days (HRD) was calculated. This HRD represents a mathematical indicator of the reduction rate of CSDH. Using this technique, the relationship between this HRD and operative method, the duration of drainage and the volume of the postoperative residual air were examined in 61 patients. Operative method (burr hole or small craniotomy) has no correlation with HRD. The duration of drainage also has no correlation. However, the volume of the residual air was highly correlated with the reduction rate of hematoma (r = 0.430; p less than 0.01). These results suggest that the residual air in the hematoma cavity may delay the reduction rate of the hematoma. Based on these results, the authors pay attention to the following points; 1) Less invasive burr hole method should be selected. 2) Patient's head position should be controlled to make the burr hole at the highest level in the operative field. 3) Hematoma cavity should be filled with saline as much as possible. 4) The inner membrane should never be injured, as it may cause tension pneumocephalus. Moreover, the drainage of cerebrospinal fluid may reduce the counter pressure and it leads to the delay of the hematoma reduction.

  12. Elimination of diazinon insecticide from cucumber surface by atmospheric pressure air-dielectric barrier discharge plasma.

    Science.gov (United States)

    Dorraki, Naghme; Mahdavi, Vahideh; Ghomi, Hamid; Ghasempour, Alireza

    2016-12-06

    The food industry is in a constant search for new technologies to improve the commercial sterilization process of agricultural commodities. Plasma treatment may offer a novel and efficient method for pesticide removal from agricultural product surfaces. To study the proposed technique of plasma food treatment, the degradation behavior of diazinon insecticide by air-dielectric barrier discharge (DBD) plasma was investigated. The authors studied the effect of different plasma powers and treatment times on pesticide concentration in liquid form and coated on the surface of cucumbers, where the diazinon residue was analyzed with mass spectroscopy gas chromatography. Our results suggest that atmospheric pressure air-DBD plasma is potentially effective for the degradation of diazinon insecticide, and mainly depends on related operating parameters, including plasma treatment time, discharge power, and pesticide concentrations. Based on the interaction between reactive oxygen species and electrons in the plasma with the diazinon molecule, two degradation pathway of diazinon during plasma treatment are proposed. It was also found that produced organophosphate pesticides are harmless and less hazardous compounds than diazinon.

  13. Simulation and Experiment Research on Fatigue Life of High Pressure Air Pipeline Joint

    Science.gov (United States)

    Shang, Jin; Xie, Jianghui; Yu, Jian; Zhang, Deman

    2017-12-01

    High pressure air pipeline joint is important part of high pressure air system, whose reliability is related to the safety and stability of the system. This thesis developed a new type-high pressure air pipeline joint, carried out dynamics research on CB316-1995 and new type-high pressure air pipeline joint with finite element method, deeply analysed the join forms of different design schemes and effect of materials on stress, tightening torque and fatigue life of joint. Research team set up vibration/pulse test bench, carried out joint fatigue life contrast test. The result shows: the maximum stress of the joint is inverted in the inner side of the outer sleeve nut, which is consistent with the failure mode of the crack on the outer sleeve nut in practice. Simulation and experiment of fatigue life and tightening torque of new type-high pressure air pipeline joint are better than CB316-1995 joint.

  14. The effect of form pressure on the air void structure of SCC

    DEFF Research Database (Denmark)

    Jensen, Mikkel Vibæk; Hasholt, Marianne Tange; Geiker, Mette Rica

    2005-01-01

    The high workability of self-compacting concrete (SCC) invites to high casting rates. However, casting walls at high rate may result in large pressure at the bottom of the form and subsequently compression of the air voids. This paper deals with the influence of hydrostatic pressure during setting...... on the air void structure of hardened, air entrained SCC. The subject was examined through laboratory investigations of SCC with two different amounts of air entrainment. The condition in the form was simulated by using containers making it possible to cure concrete under various pressures corresponding...... to the bottom of castings of 0, 2, 4, and 6 meters height. The laboratory investigations were supplemented with data from two full-scale wall castings. The air void structure of the hardened concretes was determined on plane sections. The results indicate that the pressure related changes of the air void...

  15. Molecular Dynamics Simulation of Water Nanodroplets on Silica Surfaces at High Air Pressures

    DEFF Research Database (Denmark)

    Zambrano, Harvey A; Jaffe, Richard Lawrence; Walther, Jens Honore

    2010-01-01

    e.g., nanobubbles. In the present work we study the role of air on the wetting of hydrophilic systems. We conduct molecular dynamics simulations of a water nanodroplet on an amorphous silica surface at different air pressures. The interaction potentials describing the silica, water, and air...... are obtained from the literature. The silica surface is modeled by a large 32 ⨯ 32 ⨯ 2 nm amorphous SiO2 structure consisting of 180000 atoms. The water consists of 18000 water molecules surrounded by N2 and O2 air molecules corresponding to air pressures of 0 bar (vacuum), 50 bar, 100 bar and 200 bar. We...... the effect of air and find a consistent increase in the water contact angle reaching 53º at 200 bar air pressure. These results are important for the creation and stability of nanobubbles at hydrophilic interfaces....

  16. Low air pressure effects on burning characteristics of typical oil with forced irradiance

    Science.gov (United States)

    Pan, Li; Yuen, Richard; Jian, Wang

    2017-10-01

    In this paper, a report is given on an experimental study of the combustion characteristics of typical oil with forced irradiance under two fixed ambient pressures, which may occurred in real fires. Mass loss and flame axial heat flux distribution were measured to evaluate the hazards. The burning intensity at reduced pressure is relatively lower under the circumstance without incident irradiance because the thin air for reduced pressure may attenuate the combustion. However, the burning intensity at lower pressure is higher due to the lower boiling temperature when the irradiance reaches to 10 kW/m2.The flame could engulf sufficient air to complete the combustion process for atmospheric pressure condition compared with that under low pressure, and thus resulting in relatively higher flame temperature for a fixed flame height. While in the unified plume region, the weaker air entrainment under lower pressure leads to a poorer cooling effect, i.e. higher plume temperature.

  17. Antimony and arsenic leaching from secondary lead smelter air-pollution-control residues.

    Science.gov (United States)

    Ettler, Vojtech; Mihaljevic, Martin; Sebek, Ondrej

    2010-07-01

    Environments in the vicinity of the lead (Pb) smelters are contaminated by emissions containing high concentrations of antimony (Sb) and arsenic (As). Air-pollution-control (APC) residues from bag-type filters from a secondary Pb smelter were subjected to leaching experiments to elucidate the controlling mechanisms of Sb and As release. Kinetic batch leaching tests at a liquid-to-solid (L/S) ratio of 10 L kg(- 1) within the time frame of 720 hours and batch leaching at various L/S ratios (ranging from 1 to 1000 L kg(-1)) were performed. In contrast to other inorganic contaminants (Pb, Cd, Zn), less than 1% of the total Sb and As content was leached from the residues. At a L/S ratio of 10, the As and Sb concentrations in the leachates exceeded the EU limit values for non-hazardous waste (0.2 and 0.07 mg L(-1) ). According to PHREEQC-2 calculations, the concentrations of As and Sb are controlled by the precipitation of complex arsenates and antimonates mainly at low L/S ratios. The washing and related chemical/mineralogical transformation of APC residues was suggested as a technological pre-treatment process before their re-smelting in a blast furnace. The Ferrox-like processing of the resulting contaminated process water/leachate was simulated using the PHREEQC-2 code. Significant reduction was obtained in the concentration of some key contaminants (As, Cu, Pb, Zn) related to sorption on newly formed hydrous ferric oxides, whereas Sb and Cd exhibited only limited attenuation.

  18. Air Circulation and Heat Exchange Under Reduced Pressures

    Science.gov (United States)

    Rygalov, V.; Wheeler, R.; Dixon, M.; Fowler, P.; Hillhouse, L.

    2010-01-01

    Heat exchange rates decrease non-linearly with reductions in atmospheric pressure. This decrease creates risk of thermal stress (elevated leaf temperatures) for plants under reduced pressures. Forced convection (fans) significantly increases heat exchange rate under almost all pressures except below 10 kPa. Plant cultivation techniques under reduced pressures will require forced convection. The cooling curve technique is a reliable means of assessing the influence of environmental variables like pressure and gravity on gas exchange of plant. These results represent the extremes of gas exchange conditions for simple systems under variable pressures. In reality, dense plant canopies will exhibit responses in between these extremes. More research is needed to understand the dependence of forced convection on atmospheric pressure. The overall thermal balance model should include latent and radiative exchange components.

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

    KAUST Repository

    Ahn, Yongtae

    2014-02-01

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

  20. Pulsed high-voltage discharge in air with a pressure gradient

    Science.gov (United States)

    Strikovskiy, A. V.; Evtushenko, A. A.; Gushchin, M. E.; Korobkov, S. V.; Kostrov, A. V.

    2017-10-01

    Results of experiments on high-voltage discharges in air with a pressure gradient are presented. The experiments were carried out at the setup developed at the Institute of Applied Physics, Russian Academy of Sciences. The goal of the experiments was laboratory modeling of high-altitude atmospheric discharges―sprites and jets. The setup and diagnostic techniques are described. The experimental results include the distribution of the gas pressure in the vacuum chamber formed by means of pulsed air puffing, photographs of discharges in air with a pressure gradient, and the dependences of the discharge current and optical emission intensity on the initial conditions.

  1. Improved reliability of residual heat removal capability in pressurized water reactors

    International Nuclear Information System (INIS)

    Chu, Tsong-Lun; Fitzpatrick, R.; Yoon, Won Hyo.

    1987-01-01

    The work presented in this paper was performed by Brookhaven National Laboratory (BNL) in supporting Nuclear Regulatory Commission's (NRC) effort towards the resolution of Generic Issue 99 ''Reactor Coolant System (RCS)/Residual Heat Removal (RHR) Suction Line Interlocks on Pressurized Water Reactors (PWRs).'' Operational experience of US PWRs indicates that numerous loss of RHR events have occurred during plant shutdown. Of particular significance is the loss of RHR suction due to the inadvertent closure of the RHR suction/isolation valves or an excess lowering of the water level in the reactor vessel. In the absence of prompt mitigative action by the operator, the core may become uncovered. Various design/operational changes have been proposed. The objective of this paper is to estimate the improvement in the RHR reliability and the risk reduction potential provided by those proposed RHR design/operational changes. The benefits of those changes are expressed in terms of the reduction in the frequency of loss-of-cooling events and the frequency of core damage

  2. Salinity of injection water and its impact on oil recovery absolute permeability, residual oil saturation, interfacial tension and capillary pressure

    Directory of Open Access Journals (Sweden)

    Mehdi Mohammad Salehi

    2017-06-01

    This paper presents laboratory investigation of the effect of salinity injection water on oil recovery, pressure drop, permeability, IFT and relative permeability in water flooding process. The experiments were conducted at the 80 °C and a net overburden pressure of 1700 psi using core sample. The results of this study have been shown oil recovery increases as the injected water salinity up to 200,000 ppm and appointment optimum salinity. This increase has been found to be supported by a decrease in the IFT. This effect caused a reduction in capillary pressure increasing the tendency to reduce the residual oil saturation.

  3. Control of an Isolated Table's Fluctuation Caused by Supplied Air Pressure Using a Voice Coil Motor

    Science.gov (United States)

    Shirani, Habiburahman; Wakui, Shinji

    Pneumatic type anti-vibration apparatuses are used in the field of semiconductor manufacturing and precision measurement. The variation of the supplied air pressure from the air compressor causes the position fluctuation of the isolated table. A control method using a voice coil motor (VCM) as the actuator is proposed in this study to control the position fluctuation of the isolated table caused by the supplied air pressure. The feedforward compensator control scheme is used to provide a proper controlled signal to the VCM. According to the controlled signal, VCM exerts driving force in the opposite direction of the air spring expansion or compression to suppress the vibration of the isolated table.

  4. The effectiveness of three types of alternating pressure air mattresses in the prevention of pressure ulcers in Belgian hospitals.

    Science.gov (United States)

    Demarré, Liesbet; Verhaeghe, Sofie; Van Hecke, Ann; Grypdonck, Maria; Clays, Els; Vanderwee, Katrien; Beeckman, Dimitri

    2013-10-01

    To compare the effectiveness of multi-stage and one-stage alternating low-pressure air mattresses (ALPAM) and alternating pressure air mattress (APAM) overlays in preventing pressure ulcers among hospitalized patients, data were pooled (N = 617) from a study of patients allocated to multi-stage ALPAM (n = 252) or one-stage ALPAM (n = 264), and another study of patients allocated to APAM overlay (n = 101). Cumulative pressure ulcer incidence was 4.9% (n = 30) over 14 days. Fewer ulcers developed on multi-stage ALPAM compared with APAM overlay (OR = 0.33; 95% CI [0.11, 0.97]), but no difference was found between one-stage ALPAM and APAM overlay (OR = 0.40; 95% CI [0.14, 1.10]). Time to develop ulcers did not differ by mattress type. © 2013 Wiley Periodicals, Inc.

  5. Influence of air pressure on the performance of plasma synthetic jet actuator

    International Nuclear Information System (INIS)

    Li Yang; Jia Min; Li Ying-hong; Song Hui-min; Liang Hua; Wu Yun; Zong Hao-hua

    2016-01-01

    Plasma synthetic jet actuator (PSJA) has a wide application prospect in the high-speed flow control field for its high jet velocity. In this paper, the influence of the air pressure on the performance of a two-electrode PSJA is investigated by the schlieren method in a large range from 7 kPa to 100 kPa. The energy consumed by the PSJA is roughly the same for all the pressure levels. Traces of the precursor shock wave velocity and the jet front velocity vary a lot for different pressures. The precursor shock wave velocity first decreases gradually and then remains at 345 m/s as the air pressure increases. The peak jet front velocity always appears at the first appearance of a jet, and it decreases gradually with the increase of the air pressure. A maximum precursor shock wave velocity of 520 m/s and a maximum jet front velocity of 440 m/s are observed at the pressure of 7 kPa. The averaged jet velocity in one period ranges from 44 m/s to 54 m/s for all air pressures, and it drops with the rising of the air pressure. High velocities of the precursor shock wave and the jet front indicate that this type of PSJA can still be used to influence the high-speed flow field at 7 kPa. (paper)

  6. Residual Strength Pressure Tests and Nonlinear Analyses of Stringer- and Frame-Stiffened Aluminum Fuselage Panels with Longitudinal Cracks

    Science.gov (United States)

    Young, Richard D.; Rouse, Marshall; Ambur, Damodar R.; Starnes, James H., Jr.

    1999-01-01

    The results of residual strength pressure tests and nonlinear analyses of stringer- and frame-stiffened aluminum fuselage panels with longitudinal cracks are presented. Two types of damage are considered: a longitudinal crack located midway between stringers, and a longitudinal crack adjacent to a stringer and along a row of fasteners in a lap joint that has multiple-site damage (MSD). In both cases, the longitudinal crack is centered on a severed frame. The panels are subjected to internal pressure plus axial tension loads. The axial tension loads are equivalent to a bulkhead pressure load. Nonlinear elastic-plastic residual strength analyses of the fuselage panels are conducted using a finite element program and the crack-tip-opening-angle (CTOA) fracture criterion. Predicted crack growth and residual strength results from nonlinear analyses of the stiffened fuselage panels are compared with experimental measurements and observations. Both the test and analysis results indicate that the presence of MSD affects crack growth stability and reduces the residual strength of stiffened fuselage shells with long cracks.

  7. Firefighter's compressed air breathing system pressure vessel development program

    Science.gov (United States)

    Beck, E. J.

    1974-01-01

    The research to design, fabricate, test, and deliver a pressure vessel for the main component in an improved high-performance firefighter's breathing system is reported. The principal physical and performance characteristics of the vessel which were required are: (1) maximum weight of 9.0 lb; (2) maximum operating pressure of 4500 psig (charge pressure of 4000 psig); (3) minimum contained volume of 280 in. 3; (4) proof pressure of 6750 psig; (5) minimum burst pressure of 9000 psig following operational and service life; and (6) a minimum service life of 15 years. The vessel developed to fulfill the requirements described was completely sucessful, i.e., every category of performence was satisfied. The average weight of the vessel was found to be about 8.3 lb, well below the 9.0 lb specification requirement.

  8. Surface Decontamination of Chemical Agent Surrogates Using an Atmospheric Pressure Air Flow Plasma Jet

    Science.gov (United States)

    Li, Zhanguo; Li, Ying; Cao, Peng; Zhao, Hongjie

    2013-07-01

    An atmospheric pressure dielectric barrier discharge (DBD) plasma jet generator using air flow as the feedstock gas was applied to decontaminate the chemical agent surrogates on the surface of aluminum, stainless steel or iron plate painted with alkyd or PVC. The experimental results of material decontamination show that the residual chemical agent on the material is lower than the permissible value of the National Military Standard of China. In order to test the corrosion effect of the plasma jet on different material surfaces in the decontamination process, corrosion tests for the materials of polymethyl methacrylate, neoprene, polyvinyl chloride (PVC), polyethylene (PE), phenolic resin, iron plate painted with alkyd, stainless steel, aluminum, etc. were carried out, and relevant parameters were examined, including etiolation index, chromatism, loss of gloss, corrosion form, etc. The results show that the plasma jet is slightly corrosive for part of the materials, but their performances are not affected. A portable calculator, computer display, mainboard, circuit board of radiogram, and a hygrometer could work normally after being treated by the plasma jet.

  9. Surface Decontamination of Chemical Agent Surrogates Using an Atmospheric Pressure Air Flow Plasma Jet

    International Nuclear Information System (INIS)

    Li Zhanguo; Li Ying; Cao Peng; Zhao Hongjie

    2013-01-01

    An atmospheric pressure dielectric barrier discharge (DBD) plasma jet generator using air flow as the feedstock gas was applied to decontaminate the chemical agent surrogates on the surface of aluminum, stainless steel or iron plate painted with alkyd or PVC. The experimental results of material decontamination show that the residual chemical agent on the material is lower than the permissible value of the National Military Standard of China. In order to test the corrosion effect of the plasma jet on different material surfaces in the decontamination process, corrosion tests for the materials of polymethyl methacrylate, neoprene, polyvinyl chloride (PVC), polyethylene (PE), phenolic resin, iron plate painted with alkyd, stainless steel, aluminum, etc. were carried out, and relevant parameters were examined, including etiolation index, chromatism, loss of gloss, corrosion form, etc. The results show that the plasma jet is slightly corrosive for part of the materials, but their performances are not affected. A portable calculator, computer display, mainboard, circuit board of radiogram, and a hygrometer could work normally after being treated by the plasma jet

  10. High pressure air jet in the endoscopic preparation room: risk of noise exposure on occupational health.

    Science.gov (United States)

    Chiu, King-Wah; Lu, Lung-Sheng; Wu, Cheng-Kun

    2015-01-01

    After high-level disinfection of gastrointestinal endoscopes, they are hung to dry in order to prevent residual water droplets impact on patient health. To allow for quick drying and clinical reuse, some endoscopic units use a high pressure air jet (HPAJ) to remove the water droplets on the endoscopes. The purpose of this study was to evaluate the excessive noise exposure with the use of HPAJ in endoscopic preparation room and to investigate the risk to occupational health. Noise assessment was taken during 7 automatic endoscopic reprocessors (AERs) and combined with/without HPAJ use over an 8-hour time-weighted average (TWA). Analytical procedures of the NIOSH and the ISO for noise-induced hearing loss were estimated to develop analytic models. The peak of the noise spectrum of combined HPAJ and 7 AERs was significantly higher than that of the 7 AERs alone (108.3 ± 1.36 versus 69.3 ± 3.93 dBA, P  2.5 dB) was 2.15% at 90 dBA, 11.6% at 95 dBA, and 51.3% at 100 dBA. The odds ratio was 49.1 (95% CI: 11.9 to 203.6). The noise generated by the HPAJ to work over TWA seriously affected the occupational health and safety of those working in an endoscopic preparation room.

  11. A randomised controlled trial on the effect of mask choice on residual respiratory events with continuous positive airway pressure treatment.

    Science.gov (United States)

    Ebben, Matthew R; Narizhnaya, Mariya; Segal, Alan Z; Barone, Daniel; Krieger, Ana C

    2014-06-01

    It has been found that mask style can affect the amount of continuous positive airway pressure (CPAP) required to reduce an apnoea/hyponoea index (AHI) to mask style to another post titration could affect the residual AHI with CPAP. The purpose of this study was to investigate the differences in residual AHI with CPAP treatment between oronasal and nasal masks. Twenty-one subjects (age mean (M)=62.9, body mass index (BMI) M=29.6 kg/m2) were randomised (14 subjects completed the protocol) to undergo an in-laboratory CPAP titration with either a nasal mask or an oronasal mask. Subjects were then assigned this mask for 3weeks of at-home CPAP use with the optimal treatment pressure determined on the laboratory study (CPAP M=8.4 cm of H2O). At the end of this 3-week period, data were collected from the CPAP machine and the subject was given the other mask to use with the same CPAP settings for the next 3weeks at home (if the nasal mask was given initially, the oronasal one was given later and vice versa). On completion of the second 3-week period, data on residual AHI were again collected and compared with the first 3-week period on CPAP. A Wilcoxon Signed-Rank Test (two-tailed) revealed that residual AHI with CPAP treatment was significantly higher with the oronasal compared with the nasal mask (z = -3.296, pmask, and 50% of the subjects had a residual AHI >10/h in the oronasal mask condition, even though all of these subjects were titrated to an AHI of mask compared with a nasal mask. Switching to an oronasal mask post titration results in an increase in residual AHI with CPAP treatment, and pressure adjustment may be warranted. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Post-Tensioning Duct Air Pressure Testing Effects on Web Cracking

    Science.gov (United States)

    2015-01-01

    Nevada Department of Transportation (NDOT) post-tensioned concrete bridges have experienced web cracking near the post-tensioning ducts during the construction process. The ducts were air pressure tested to ensure the duct can successfully be grouted...

  13. TAO/TRITON, RAMA, and PIRATA Buoys, Daily, 1998-present, Barometric (Air) Pressure

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has daily Barometric (Air) Pressure data from the TAO/TRITON (Pacific Ocean, https://www.pmel.noaa.gov/gtmba/ ), RAMA (Indian Ocean,...

  14. TAO/TRITON, RAMA, and PIRATA Buoys, Monthly, 1998-present, Barometric (Air) Pressure

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has monthly Barometric (Air) Pressure data from the TAO/TRITON (Pacific Ocean, https://www.pmel.noaa.gov/gtmba/ ), RAMA (Indian Ocean,...

  15. The influence of electrodialytic remediation on dioxin (PCDD/PCDF) levels in fly ash and air pollution control residues

    DEFF Research Database (Denmark)

    Dias-Ferreira, Celia; Kirkelund, Gunvor Marie; Jensen, Pernille Erland

    2016-01-01

    materials dissolve, leaving behind the non-water soluble compounds, such as PCDD/PCDF. According to the Basel Convention, PCDD/PCDF levels in these materials is low (residue could eventually be valorized, for instance as construction material, provided end......Fly ash and Air Pollution Control (APC) residues collected from three municipal solid waste incinerators in Denmark and Greenland were treated by electrodialytic remediation at pilot scale for 8-10 h. This work presents for the first time the effect of electrodialytic treatment on polychlorinated...... dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF), and how these levels impact on the valorization options for fly ash and APC residue.PCDD/PCDF levels in the original residues ranged between 4.85 and 197 ng g-1, being higher for the electrostatic precipitator fly ash. The toxic equivalent...

  16. Air Quality and Health Impacts of an Aviation Biofuel Supply Chain Using Forest Residue in the Northwestern United States.

    Science.gov (United States)

    Ravi, Vikram; Gao, Allan H; Martinkus, Natalie B; Wolcott, Michael P; Lamb, Brian K

    2018-04-03

    Forest residue is a major potential feedstock for second-generation biofuel; however, little knowledge exists about the environmental impacts of the development and production of biofuel from such a feedstock. Using a high-resolution regional air quality model, we estimate the air quality impacts of a forest residue based aviation biofuel supply chain scenario in the Pacific Northwestern United States. Using two potential supply chain regions, we find that biomass and biofuel hauling activities will add simulation. Using BenMAP, a health impact assessment tool, we show that avoiding slash pile burning results in a decrease in premature mortality as well as several other nonfatal and minor health effects. In general, we show that most air quality and health benefits result primarily from avoided slash pile burning emissions.

  17. Effects of oxygen partial pressure on Li-air battery performance

    Science.gov (United States)

    Kwon, Hyuk Jae; Lee, Heung Chan; Ko, Jeongsik; Jung, In Sun; Lee, Hyun Chul; Lee, Hyunpyo; Kim, Mokwon; Lee, Dong Joon; Kim, Hyunjin; Kim, Tae Young; Im, Dongmin

    2017-10-01

    For application in electric vehicles (EVs), the Li-air battery system needs an air intake system to supply dry oxygen at controlled concentration and feeding rate as the cathode active material. To facilitate the design of such air intake systems, we have investigated the effects of oxygen partial pressure (≤1 atm) on the performance of the Li-air cell, which has not been systematically examined. The amounts of consumed O2 and evolved CO2 from the Li-air cell are measured with a custom in situ differential electrochemical gas chromatography-mass spectrometry (DEGC-MS). The amounts of consumed O2 suggest that the oxygen partial pressure does not affect the reaction mechanism during discharge, and the two-electron reaction occurs under all test conditions. On the other hand, the charging behavior varies by the oxygen partial pressure. The highest O2 evolution ratio is attained under 70% O2, along with the lowest CO2 evolution. The cell cycle life also peaks at 70% O2 condition. Overall, an oxygen partial pressure of about 0.5-0.7 atm maximizes the Li-air cell capacity and stability at 1 atm condition. The findings here indicate that the appropriate oxygen partial pressure can be a key factor when developing practical Li-air battery systems.

  18. The upper explosion limit of lower alkanes and alkenes in air at elevated pressures and temperatures.

    Science.gov (United States)

    Van den Schoor, F; Verplaetsen, F

    2006-01-16

    The upper explosion limit (UEL) of ethane-air, propane-air, n-butane-air, ethylene-air and propylene-air mixtures is determined experimentally at initial pressures up to 30 bar and temperatures up to 250 degrees C. The experiments are performed in a closed spherical vessel with an internal diameter of 200 mm. The mixtures are ignited by fusing a coiled tungsten wire, placed at the centre of the vessel, by electric current. Flame propagation is said to have taken place if there is a pressure rise of at least 1% of the initial pressure after ignition of the mixture. In the pressure-temperature range investigated, a linear dependence of UEL on temperature and a bilinear dependence on pressure are found except in the vicinity of the auto-ignition range. A comparison of the UEL data of the lower alkanes shows that the UEL expressed as equivalence ratio (the actual fuel/air ratio divided by the stoichiometric fuel/air ratio) increases with increasing carbon number in the homologous series of alkanes.

  19. Geochemical modeling of leaching from MSVI air-pollution-control residues

    DEFF Research Database (Denmark)

    Astrup, Thomas; Dijkstra, J.J.; Comans, R.N.J.

    2006-01-01

    This paper provides an improved understanding of the leaching behavior of waste incineration air-pollution-control (APC) residues in a long-term perspective. Leaching was investigated by a series of batch experiments reflecting leaching conditions after initial washout of highly soluble salts from...... of Al, Ba, Ca, Cr, Pb, S, Si, V, and Zn was found influenced by solubility control from Al2O3, Al(OH)3, Ba(S,Cr)O4 solid solutions, BaSO4, Ca6Al2(SO4)3(OH)12â26H2O, CaAl2Si4O12â2H2O, Ca-(OH)2, CaSiO3, CaSO4â2H2O, CaZn2(OH)6â2H2O, KAlSi2O6, PbCO3, PbCrO4, Pb2O3, Pb2V2O7, Pb3(VO4)2, ZnO, Zn2SiO4, and Zn...

  20. Utilization of air pollution control residues for the stabilization/solidification of trace element contaminated soil.

    Science.gov (United States)

    Travar, I; Kihl, A; Kumpiene, J

    2015-12-01

    The aim of this study was to evaluate the stabilization/solidification (S/S) of trace element-contaminated soil using air pollution control residues (APCRs) prior to disposal in landfill sites. Two soil samples (with low and moderate concentrations of organic matter) were stabilized using three APCRs that originated from the incineration of municipal solid waste, bio-fuels and a mixture of coal and crushed olive kernels. Two APCR/soil mixtures were tested: 30% APCR/70% soil and 50% APCR/50% soil. A batch leaching test was used to study immobilization of As and co-occurring metals Cr, Cu, Pb and Zn. Solidification was evaluated by measuring the unconfined compression strength (UCS). Leaching of As was reduced by 39-93% in APCR/soil mixtures and decreased with increased amounts of added APCR. Immobilization of As positively correlated with the amount of Ca in the APCR and negatively with the amount of soil organic matter. According to geochemical modelling, the precipitation of calcium arsenate (Ca3(AsO4)2/4H2O) and incorporation of As in ettringite (Ca6Al2(SO4)3(OH)12 · 26H2O) in soil/APCR mixtures might explain the reduced leaching of As. A negative effect of the treatment was an increased leaching of Cu, Cr and dissolved organic carbon. Solidification of APCR/soil was considerably weakened by soil organic matter.

  1. Recycling potential of air pollution control residue from sewage sludge thermal treatment as artificial lightweight aggregates.

    Science.gov (United States)

    Bialowiec, Andrzej; Janczukowicz, Wojciech; Gusiatin, Zygmunt M; Thornton, Arthur; Rodziewicz, Joanna; Zielinska, Magdalena

    2014-03-01

    Thermal treatment of sewage sludge produces fly ash, also known as the air pollution control residue (APCR), which may be recycled as a component of artificial lightweight aggregates (ALWA). Properties of APCR are typical: high content of Ca, Mg, P2O5, as well as potential to induce alkaline reactions. These properties indicate that ALWA prepared with a high content of APCR may remove heavy metals, phosphorus, and ammonium nitrogen from wastewater with high efficiency. The aim of this preliminary study was to determine the optimal composition of ALWA for potential use as a filter media in wastewater treatment systems. Five kinds of ALWA were produced, with different proportions of ash (shown as percentages in subscripts) in mixture with bentonite: ALWA0 (reference), ALWA12.5, ALWA25, ALWA50, and ALWA100. The following parameters of ALWA were determined: density, bulk density, compressive strength, hydraulic conductivity, and removal efficiency of ions Zn(2+), NH4 (+), and PO4 (3-). Tests showed that ALWA had good mechanical and hydraulic properties, and might be used in wastewater filtering systems. Phosphates and zinc ions were removed with high efficiency (80-96%) by ALWA25-100 in static (batch) conditions. The efficiency of ammonium nitrogen removal was low, <18%. Artificial wastewater treatment performance in dynamic conditions (through-flow), showed increasing removal efficiency of Zn(2+), PO4 (3-) with a decrease in flow rate.

  2. Air pollution, blood pressure, and the risk of hypertensive complications during pregnancy: The generation r study

    NARCIS (Netherlands)

    Hooven, E.H. van den; Kluizenaar, Y. de; Pierik, F.H.; Hofman, A.; Ratingen, S.W. van; Zandveld, P.Y.J.; MacKenbach, J.P.; Steegers, E.A.P.; Miedema, H.M.E.; Jaddoe, V.W.V.

    2011-01-01

    Exposure to air pollution is associated with elevated blood pressure and cardiovascular disease. We assessed the associations of exposure to particulate matter (PM10) and nitrogen dioxide (NO2) levels with blood pressure measured in each trimester of pregnancy and the risks of pregnancy-induced

  3. The Effects of Air Pressure on Spontaneous Otoacoustic Emissions of Lizards

    NARCIS (Netherlands)

    van Dijk, Pim; Manley, Geoffrey A.

    Small changes of air pressure outside the eardrum of five lizard species led to changes in frequency, level, and peak width of spontaneous otoacoustic emissions (SOAE). In contrast to humans, these changes generally occurred at very small pressures (<20 mbar). As in humans, SOAE amplitudes were

  4. The conceptual design of high temporal resolution HCN interferometry for atmospheric pressure air plasmas

    Science.gov (United States)

    Zhang, J. B.; Liu, H. Q.; Jie, Y. X.; Wei, X. C.; Hu, L. Q.

    2018-01-01

    A heterodyne interferometer operating at the frequency f = 890 GHz has been designed for measuring the electron density of atmospheric pressure air plasmas, it's density range is from 1015 to 3×1019 m-3 and the pressure range is from 1 Pa to 20 kPa. The system is configured as a Mach\

  5. Effect of preemptive weld overlay on residual stress mitigation for dissimilar metal weld of nuclear power plant pressurizer

    Energy Technology Data Exchange (ETDEWEB)

    Song, Tae Kwang; Bae, Hong Yeol; Chun, Yun Bae; Oh, Chang Young; Kim, Yun Jae [Korea University, Seoul (Korea, Republic of); Lee, Kyoung Soo; Park, Chi Yong [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

    2008-10-15

    Weld overlay is one of the residual stress mitigation methods which arrest crack initiation and crack growth. Therefore weld overlay can be applied to the region where cracking is likely to be. An overlay weld used in this manner is termed a Preemptive Weld OverLay(PWOL). In Pressurized Water Reactor(PWR) dissimilar metal weld is susceptible region for Primary Water Stress Corrosion Cracking(PWSCC). In order to examine the effect of PWOL on residual stress mitigation, PWOL was applied to a specific dissimilar metal weld of Kori nuclear power plant by finite element analysis method. As a result, strong compressive residual stress was made in PWSCC susceptible region and PWOL was proved effective preemptive repair method for weldment.

  6. Effect of air content and mass inflow on the pressure rise in a containment during blowdown

    International Nuclear Information System (INIS)

    Marshall, J.; Holland, P.G.

    1977-01-01

    Experiments were made to investigate conditions arising during blowdown of a vessel filled with saturated steam/water at 7 MPa pressure into a containment vessel. The initial air pressure in the containment vessel was varied from one atmosphere to near vacuum. The initial water content of the high pressure vessel was varied. Pressure and temperature distributions were measured during the blowdown transient and compared with calculations based on a simple lumped-parameter model. The effect of condensation heat transfer on the containment pressure is discussed and attention drawn to the inadequacy of most available data. (Author)

  7. Continuous Positive Airway Pressure Thresholds for Nasolacrimal Air Regurgitation in a Cadaveric Model.

    Science.gov (United States)

    Blandford, Alexander D; Cherfan, Daniel G; Drake, Richard L; McBride, Jennifer M; Hwang, Catherine J; Perry, Julian D; Cheng, Olivia T

    2018-01-10

    To elucidate the mechanisms underlying nasolacrimal air regurgitation (AR) in the setting of continuous positive airway pressure therapy. Twelve nasolacrimal systems of 6 fresh female human cadavers were evaluated individually for AR using continuous positive airway pressure therapy before any nasolacrimal procedure. Cadavers were then randomly assigned to undergo nasolacrimal duct probing or endoscopic dacryocystorhinostomy and then each hemisystem was again evaluated for AR. The pressure where AR was first observed (discovery pressure) or maximum possible pressure in systems without AR was recorded. In systems that demonstrated AR, the pressure was then gradually decreased to the lowest pressure where regurgitation persisted. This pressure was recorded as the secondary threshold pressure. None of the 12 unoperated nasolacrimal systems or the 6 systems that underwent nasolacrimal duct probing demonstrated AR through the maximum continuous positive airway pressure therapy (30 cm H2O). After endoscopic dacryocystorhinostomy, all 6 nasolacrimal systems demonstrated AR. The mean discovery pressure was 16.0 cm H2O (range, 14.0-18.0 cm H2O) and mean secondary threshold pressure was 7.25 cm H2O (range, 6.5-8.0 cm H2O). Air regurgitation during continuous positive airway pressure therapy in the setting of prior endoscopic dacryocystorhinostomy can be replicated in a cadaver model. The secondary threshold pressures required for AR in this model were similar to AR pressures reported clinically. Prior to dacryocystorhinostomy, patients using continuous positive airway pressure therapy should be counseled on AR, and physicians should consider this phenomenon when evaluating ophthalmic complaints in postoperative patients on positive airway pressure therapy.

  8. Air pressure waves from Mount St. Helens eruptions

    Science.gov (United States)

    Reed, Jack W.

    1987-10-01

    Infrasonic recordings of the pressure wave from the Mount St. Helens (MSH) eruption on May 18, 1980, together with the weather station barograph records were used to estimate an equivalent explosion airblast yield for this eruption. Pressure wave amplitudes versus distance patterns were found to be comparable with patterns found for a small-scale nuclear explosion, the Krakatoa eruption, and the Tunguska comet impact, indicating that the MSH wave came from an explosion equivalent of about 5 megatons of TNT. The peculiar audibility pattern reported, with the blast being heard only at ranges beyond about 100 km, is explained by consideration of finite-amplitude shock propagation developments.

  9. Air mass flow estimation in turbocharged diesel engines from in-cylinder pressure measurement

    Energy Technology Data Exchange (ETDEWEB)

    Desantes, J.M.; Galindo, J.; Guardiola, C.; Dolz, V. [CMT - Motores Termicos, Universidad Politecnica de Valencia (Spain)

    2010-01-15

    Air mass flow determination is needed for the control of current internal combustion engines. Current methods are based on specific sensors (as hot wire anemometers) or indirect estimation through manifold pressure. With the availability of cylinder pressure sensors for engine control, methods based on them can be used for replacing or complementing standard methods. Present paper uses in cylinder pressure increase during the intake stroke for inferring the trapped air mass. The method is validated on two different turbocharged diesel engines and compared with the standard methods. (author)

  10. Molecular dynamics simulations of water on a hydrophilic silica surface at high air pressures

    DEFF Research Database (Denmark)

    Zambrano, H.A.; Walther, Jens Honore; Jaffe, R.L.

    2014-01-01

    of air in water at different pressures. Using the calibrated force field, we conduct MD simulations to study the interface between a hydrophilic silica substrate and water surrounded by air at different pressures. We find that the static water contact angle is independent of the air pressure imposed......Wepresent a force field forMolecular Dynamics (MD) simulations ofwater and air in contactwith an amorphous silica surface. We calibrate the interactions of each species present in the systemusing dedicated criteria such as the contact angle of a water droplet on a silica surface, and the solubility...... on the system. Our simulations reveal the presence of a nanometer thick layer of gas at the water–silica interface. We believe that this gas layer could promote nucleation and stabilization of surface nanobubbles at amorphous silica surfaces. © 2014 Elsevier B.V. All rights reserved....

  11. Evaluation of J-groove weld residual stress and crack growth rate of PWSCC in reactor pressure vessel closure head

    International Nuclear Information System (INIS)

    Oh, Seung Hyuk; Ryu, Tae Young; Park, Seung Hyun; Won, Min Gu; Kang, Seok Jun; Kim, Moon Ki; Choi, Jae Boong; Lee, Kyoung Soo; Lee, Sung Ho

    2015-01-01

    Over the last decade, primary water stress corrosion cracking (PWSCC) has been frequently found in pressurized water reactor (PWR) applications. Especially, PWSCC has occurred in long-term operated PWRs. As this phenomenon leads to serious accidents, we must be beforehand with the anticipated problems. A typical PWR consists of J-groove welded components such as reactor pressure vessel closure head and nozzles. Reactor pressure vessel closure head is made of SA508 and it is covered by cladding. Alloy 600 is used for nozzles. And J-groove weld is conducted with alloy 82/182. Different material properties of these metals lead to residual stress and PWSCC consequentially. In this study, J-groove weld residual stress was investigated by a three-dimensional finite element analysis with an actual asymmetric J-groove weld model and process of construction. Also crack growth rate of PWSCC was evaluated from cracks applied on the penetration nozzles. Based on these two values, one cannot only improve the structural integrity of PWR, but also explain PWSCC behavior such that high residual stress at the J-groove weld area causes crack initiation and propagation through the surface of nozzles. In addition, crack behavior was predicted at the various points around the nozzle.

  12. Correlation Between Endotracheal Tube Cuff Pressure and Tracheal Wall Pressure Using Air and Saline Filled Cuffs

    Science.gov (United States)

    2017-01-31

    sell any patented invention that may relate to them. Qualified requestors may obtain copies of this report from the Defense Technical Information...been the assumption that the pressure measured at the pilot balloon is equal to the pressure exerted on the TW. We evaluated ETTs at sea level and...Pressure Profile Systems, Los Angeles, CA) and the ETT pilot balloon via a data logger (Sparx Engineering, Manvel, TX). Figure 1

  13. Pressure Measurement and Flowfield Characterization of a Two-Dimensional Ideally Expanded, Constant Area, Air/air Ejector.

    Science.gov (United States)

    Benjamin, Michael Anthony

    A detailed experimental investigation of a two -dimensional, Mach 1.8 air-primary, Mach 0.3 air-secondary ejector at high Reynolds number has been performed, from which a nonintrusive method for whole-field visualization using turbulent wall-pressure has been developed. The experiments were conducted using mean and time-accurate wall pressure measurements, impact-pressure measurements using a traversing probe, and Schlieren and shadowgraph visualization techniques. The time-accurate pressure measurements were recorded using a sealed Kulite miniature pressure transducer with a 0.7 mm diameter sensing diaphragm. For all except the optical methods, measurements were taken from the initial flow interface to about 13 hydraulic tube-diameters downstream in the constant-area mixing section. From the mean measurements, values of stagnation pressure, density, velocity, static pressure, Mach number, and dynamic pressure were developed and are presented. Using the time-accurate pressure measurements, a color contour plot of the rms pressure was developed that definitively shows the regions of the flow in agreement with the other measurements. Additionally, probability density functions, skewness, and kurtosis were calculated. Peak values of skewness (S) and kurtosis (K) on the centerline at about 2.5 hydraulic diameters are S = 1.85 and K = 11.5. The inlet rms pressure values, normalized by freestream dynamic pressure for the primary (~0.001), were found to be in fair agreement with previous experimental values; however, those in the secondary were much higher (~0.2), apparently due to the acoustic radiation from the primary. Fourier analysis of the time-accurate pressure measurements show that the autospectra contain k ^{-1}, k^{-7/3}, and k^{-11/3} pressure spectrum functions as predicted by prevailing theory for the overlap layer, turbulence-turbulence interaction, and turbulence-mean-shear interaction, respectively. It is believed that this is the first experiment in

  14. Influence of ambient air pressure on impact pressure caused by breaking waves

    NARCIS (Netherlands)

    Moutzouris, C.

    1979-01-01

    Engineers are interested in the dynamics of the interface waterstructure. In case of breaking of water waves on a structure high positive and sometimes negative pressures of very short duration occur. Not only the maxima and minima of the pressures on the structure are important to a designing

  15. Air temperature determination inside residual heat removal pump room of Angra-1 nuclear power plant after a design basic accident

    International Nuclear Information System (INIS)

    Siniscalchi, Marcio Rezende

    2005-01-01

    This work develops heat transfer theoretical models for determination of air temperature inside the Residual Heat Removal Pump Room of Angra 1 Nuclear Power Plant after a Design Basis Accident without forced ventilation. Two models had been developed. The differential equations are solved by analytical methods. A software in FORTRAN language are developed for simulations of temperature inside rooms for different geometries and materials. (author)

  16. Risk for intracranial pressure increase related to enclosed air in post-craniotomy patients during air ambulance transport: a retrospective cohort study with simulation.

    Science.gov (United States)

    Brändström, Helge; Sundelin, Anna; Hoseason, Daniela; Sundström, Nina; Birgander, Richard; Johansson, Göran; Winsö, Ola; Koskinen, Lars-Owe; Haney, Michael

    2017-05-12

    Post-craniotomy intracranial air can be present in patients scheduled for air ambulance transport to their home hospital. We aimed to assess risk for in-flight intracranial pressure (ICP) increases related to observed intracranial air volumes, hypothetical sea level pre-transport ICP, and different potential flight levels and cabin pressures. A cohort of consecutive subdural hematoma evacuation patients from one University Medical Centre was assessed with post-operative intracranial air volume measurements by computed tomography. Intracranial pressure changes related to estimated intracranial air volume effects of changing atmospheric pressure (simulating flight and cabin pressure changes up to 8000 ft) were simulated using an established model for intracranial pressure and volume relations. Approximately one third of the cohort had post-operative intracranial air. Of these, approximately one third had intracranial air volumes less than 11 ml. The simulation estimated that the expected changes in intracranial pressure during 'flight' would not result in intracranial hypertension. For intracranial air volumes above 11 ml, the simulation suggested that it was possible that intracranial hypertension could develop 'inflight' related to cabin pressure drop. Depending on the pre-flight intracranial pressure and air volume, this could occur quite early during the assent phase in the flight profile. DISCUSSION: These findings support the idea that there should be radiographic verification of the presence or absence of intracranial air after craniotomy for patients planned for long distance air transport. Very small amounts of air are clinically inconsequential. Otherwise, air transport with maintained ground-level cabin pressure should be a priority for these patients.

  17. Integration optimisation of elevated pressure air separation unit with gas turbine in an IGCC power plant

    International Nuclear Information System (INIS)

    Han, Long; Deng, Guangyi; Li, Zheng; Wang, Qinhui; Ileleji, Klein E.

    2017-01-01

    Highlights: • IGCC thermodynamic model was setup carefully. • Simulations focus on integration between an elevated pressure ASU with gas turbine. • Different recommended solutions from those of low pressure ASUs are figured out. • Full N 2 injection and 80% air extraction was suggested as the optimum integration. - Abstract: The integration optimisation between an elevated pressure air separation unit (EP-ASU) and gas turbine is beneficial to promote net efficiency of an integrated gasification combined cycle (IGCC) power plant. This study sets up the thermodynamic model for a 400 MW plant specially coupled with an EP-ASU, aiming to examine system performances under different integrations and acquire the optimum solution. Influences of air extraction rate at conditions of without, partial and full N 2 injection, as well as the effects of N 2 injection rate when adopting separate ASU, partial and full integrated ASU were both analysed. Special attention has been paid to performance differences between utilising an EP-ASU and a low pressure unit. Results indicated that integration solution with a separate EP-ASU or without N 2 injection would not be reasonable. Among various recommended solutions for different integration conditions, N 2 injection rate increased with the growth of air extraction rate. The integration with an air extraction rate of 80% and full N 2 injection was suggested as the optimum solution. It is concluded that the optimum integration solution when adopting an EP-ASU is different from that using a low pressure one.

  18. The pressure drop characteristics of air-water bubbling flow for evaporative heat transfer

    Science.gov (United States)

    Chen, Qinghua; Amano, R. S.; Cui, Wenzhi; Li, Longjian

    2008-05-01

    This paper presents a study on a novel water bubbling layer pressure drop and heat transfer experiment that was conducted to investigate the characteristics of pressure drop of air flow across the water bubbling layer. The attempt was to reduce the pressure drop while maintaining a higher value of the heat transfer coefficient. This type of heat transfer between water and merged tubes has potential application in evaporative cooling. To achieve the goal the pressure drop should be reduced by decreasing the bubble layer thickness through the water pump circulation. Pressure drops of air passing through the perforated plate and the water bubbling layer were measured for different heights of water bubbling layer, hole-plate area ratio of the perforated plate and the air velocity through the holes. Experimental data show that the increase of water bubbling layer height and air velocity both increase the pressure drop while the effect of the hole-plate area ratio of the perforated plate on the heat transfer coefficient is relatively complex. The measurements showed that even at a considerably lower height of water bubbling layer the heat transfer coefficient can exceed 5,000 W/m2-K. The heat transfer coefficients of 30 mm high water bubbling layer are higher than that of other higher water bubbling layers tested in the experiments

  19. The influence of electrodialytic remediation on dioxin (PCDD/PCDF) levels in fly ash and air pollution control residues.

    Science.gov (United States)

    Dias-Ferreira, Celia; Kirkelund, Gunvor M; Jensen, Pernille E

    2016-04-01

    Fly ash and Air Pollution Control (APC) residues collected from three municipal solid waste incinerators in Denmark and Greenland were treated by electrodialytic remediation at pilot scale for 8-10 h. This work presents for the first time the effect of electrodialytic treatment on polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF), and how these levels impact on the valorization options for fly ash and APC residue. PCDD/PCDF levels in the original residues ranged between 4.85 and 197 ng g(-1), being higher for the electrostatic precipitator fly ash. The toxic equivalent (TEQ) varied ten fold, ranging 0.18-2.0 ng g(-1) I-TEQ, with penta and hexa-homologs being most significant for toxicity. After the electrodialytic treatment PCDD/PCDF levels increased in the residues (between 1.4 and 2.0 times). This does not mean PCDD/PCDF were synthesized, but else that soluble materials dissolve, leaving behind the non-water soluble compounds, such as PCDD/PCDF. According to the Basel Convention, PCDD/PCDF levels in these materials is low (residue could eventually be valorized, for instance as construction material, provided end-of-waste criteria are set and that a risk assessment of individual options is carried out, including the end-of-life stage when the materials become waste again. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Measured pressure distributions of large-angle cones in hypersonic flows of tetrafluoromethane, air, and helium

    Science.gov (United States)

    Jones, R. A.; Hunt, J. L.

    1973-01-01

    An experimental study of surface pressure distributions on a family of blunt and sharp large angle cones was made in hypersonic flows of helium, air, and tetrafluoromethane. The effective isentropic exponents of these flows were 1.67, 1.40, and 1.12. Thus, the effect of large shock density ratios such as might be encountered during planetary entry because of real-gas effects could be studied by comparing results in tetrafluoromethane with those in air and helium. It was found that shock density ratio had a large effect on both shock shape and pressure distribution. The differences in pressure distribution indicate that for atmospheric flight at high speed where real-gas effects produce large shock density ratios, large-angle cone vehicles can be expected to experience different trim angles of attack, drag coefficient, and lift-drag ratios than those for ground tests in air wind tunnels.

  1. Influence of air pressure on soliton formation in hollow-core photonic bandgap fibers

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Roberts, Peter John

    2009-01-01

    Abstract Soliton formation during dispersive compression of chirped few-picosecond pulses at the microjoule level in a hollow-core photonic bandgap (HC-PBG) fiber is studied by numerical simulations. Long-pass filtering of the emerging frequency-shifted solitons is investigated with the objective...... of obtaining pedestal-free output pulses. Particular emphasis is placed on the influence of the air pressure in the HC-PBG fiber. It is found that a reduction in air pressure enables an increase in the fraction of power going into the most redshifted soliton and also improves the quality of the filtered pulse...

  2. An Ultra-low Frequency Modal Testing Suspension System for High Precision Air Pressure Control

    Directory of Open Access Journals (Sweden)

    Qiaoling YUAN

    2014-05-01

    Full Text Available As a resolution for air pressure control challenges in ultra-low frequency modal testing suspension systems, an incremental PID control algorithm with dead band is applied to achieve high-precision pressure control. We also develop a set of independent hardware and software systems for high-precision pressure control solutions. Taking control system versatility, scalability, reliability, and other aspects into considerations, a two-level communication employing Ethernet and CAN bus, is adopted to complete such tasks as data exchange between the IPC, the main board and the control board ,and the pressure control. Furthermore, we build a single set of ultra-low frequency modal testing suspension system and complete pressure control experiments, which achieve the desired results and thus confirm that the high-precision pressure control subsystem is reasonable and reliable.

  3. Numerical simulation of premixed Hydrogen/air combustion pressure in a spherical vessel

    OpenAIRE

    Guo Han-yu; Tao Gang; Zhang Li-jing

    2016-01-01

    In order to study the development process of hydrogen combustion in a closed vessel, an on-line chemical equilibrium calculator and a numerical simulation method would be used to analysis the combustion pressure and flame front of mixed gas, which based on 20L H2/air explosion experiments in spherical vessel (Crowl and Jo,2009). The results showed that, the turbulent model could reflect the process of combustion, and the error of combustion pressure by simulation is smaller than the Chemical ...

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

    Science.gov (United States)

    2015-06-01

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

  5. Prevention of pressure ulcers with a static air support surface: A systematic review.

    Science.gov (United States)

    Serraes, Brecht; van Leen, Martin; Schols, Jos; Van Hecke, Ann; Verhaeghe, Sofie; Beeckman, Dimitri

    2018-03-05

    The aims of this study were to identify, assess, and summarise available evidence about the effectiveness of static air mattress overlays to prevent pressure ulcers. The primary outcome was the incidence of pressure ulcers. Secondary outcomes included costs and patient comfort. This study was a systematic review. Six electronic databases were consulted: Cochrane Library, EMBASE, PubMed (Medline), CINAHL (EBSCOhost interface), Science direct, and Web of Science. In addition, a hand search through reviews, conference proceedings, and the reference lists of the included studies was performed to identify additional studies. Potential studies were reviewed and assessed by 2 independent authors based on the title and abstract. Decisions regarding inclusion or exclusion of the studies were based on a consensus between the authors. Studies were included if the following criteria were met: reporting an original study; the outcome was the incidence of pressure ulcer categories I to IV when using a static air mattress overlay and/or in comparison with other pressure-redistribution device(s); and studies published in English, French, and Dutch. No limitation was set on study setting, design, and date of publication. The methodological quality assessment was evaluated using the Critical Appraisal Skills Program Tool. Results were reported in a descriptive way to reflect the exploratory nature of the review. The searches included 13 studies: randomised controlled trials (n = 11) and cohort studies (n = 2). The mean pressure ulcer incidence figures found in the different settings were, respectively, 7.8% pressure ulcers of categories II to IV in nursing homes, 9.06% pressure ulcers of categories I to IV in intensive care settings, and 12% pressure ulcers of categories I to IV in orthopaedic wards. Seven comparative studies reported a lower incidence in the groups of patients on a static air mattress overlay. Three studies reported a statistical (P < .1) lower

  6. [Residual levels in air, soil and soil-air exchange of organochlorine pesticides in Hami region of Xinjiang and its potential ecological risk].

    Science.gov (United States)

    Ma, Zi-Long; Mao, Xiao-Xuan; Ding, Zhong-Yuan; Gao, Hong; Huang, Tao; Tian, Hui; Guo, Qiang

    2013-03-01

    The concentrations of HCHs and DDTs in soil and air of urban/rural/forestry centre locations in the Hami region of Xinjiang were monitored for a year by passive atmospheric sampling in order to study the residual levels and air-soil exchange and evaluate ecological risk. The study results showed that the annual average concentrations of HCHs and DDTs in the air of Hami were 107.1 pg x m(-3) and 43.9 pg x m(-3), respectively, and the concentrations of HCHs and DDTs in summer and autumn were generally higher than those in winter and spring. It was deduced that the HCHs and DDTs tended to evaporate into the air because of the higher temperatures in summer and autumn. For OCPs in the air of study area, HCHs were dominanted the main pollution compared with DDTs. Meanwhile, alpha-HCH contributed the largest portion among all HCHs isomers, and p,p'-DDE dominated the residual levels of DDTs. Moreover, the values of alpha-HCH/gamma-HCH were in the range of 3 to 7, which indicated that the use of technical HCHs or the long distance atmosphere transport of HCHs may play a significant role for HCHs in the air of Hami region. Furthermore, ratios of (DDD + DDE)/DDTs were in the range of 0.4-0.9, 71.4% of which were higher than 0.5, indicating that DDTs in the air were mainly from historical usage and no new DDTs sources emerged in Hami recently. The concentrations of HCHs and DDTs in soil were between 0.344-6.954 ng x g(-1) and 0.104-26.397 ng x g(-1), respectively, which did not exceed the National Soil Quality Standard Level I. In addition, DDTs predominated in soil OCPs, in which beta-HCH accounting for a huge percentage in HCHs isomers, while o,p'-DDT predominated in pollution caused by DDTs isomers. From study results, it was also suggested that the important cause of DDTs residues in soil of Hami area could be the recent inputs of new sources since the value of (DDD + DDE)/DDTs were lower than 0.5. The sources of HCHs and DDTs in soil and atmosphere were not consistent

  7. Treatment of air pollution control residues with iron rich waste sulfuric acid: does it work for antimony (Sb)?

    Science.gov (United States)

    Okkenhaug, Gudny; Breedveld, Gijs D; Kirkeng, Terje; Lægreid, Marit; Mæhlum, Trond; Mulder, Jan

    2013-03-15

    Antimony (Sb) in air pollution control (APC) residues from municipal solid waste incineration has gained increased focus due to strict Sb leaching limits set by the EU landfill directive. Here we study the chemical speciation and solubility of Sb at the APC treatment facility NOAH Langøya (Norway), where iron (Fe)-rich sulfuric acid (∼3.6M, 2.3% Fe(II)), a waste product from the industrial extraction of ilmenite, is used for neutralization. Antimony in water extracts of untreated APC residues occurred exclusively as pentavalent antimonate, even at low pH and Eh values. The Sb solubility increased substantially at pH<10, possibly due to the dissolution of ettringite (at alkaline pH) or calcium (Ca)-antimonate. Treated APC residues, stored anoxically in the laboratory, simulating the conditions at the NOAH Langøya landfill, gave rise to decreasing concentrations of Sb in porewater, occurring exclusively as Sb(V). Concentrations of Sb decreased from 87-918μgL(-1) (day 3) to 18-69μgL(-1) (day 600). We hypothesize that an initial sorption of Sb to Fe(II)-Fe(III) hydroxides (green rust) and eventually precipitation of Ca- and Fe-antimonates (tripuhyite; FeSbO4) occurred. We conclude that Fe-rich, sulfuric acid waste is efficient to immobilize Sb in APC residues from waste incineration. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Spatiotemporally resolved characteristics of a gliding arc discharge in a turbulent air flow at atmospheric pressure

    DEFF Research Database (Denmark)

    Zhu, Jiajian; Gao, Jinlong; Ehn, Andreas

    2017-01-01

    A gliding arc discharge was generated in a turbulent air flow at atmospheric pressure driven by a 35 kHz alternating current (AC) electric power. The spatiotemporally resolved characteristics of the gliding arc discharge, including glow-type discharges, spark-type discharges, short-cutting events...

  9. Sustained diffusive alternating current gliding arc discharge in atmospheric pressure air

    DEFF Research Database (Denmark)

    Zhu, Jiajian; Gao, Jinlong; Li, Zhongshan

    2014-01-01

    Rapid transition from glow discharge to thermal arc has been a common problem in generating stable high-power non-thermal plasmas especially at ambient conditions. A sustained diffusive gliding arc discharge was generated in a large volume in atmospheric pressure air, driven by an alternating...

  10. Air Compressor Pressure Control System Based On Gearshift Integral PID Controller

    Directory of Open Access Journals (Sweden)

    PAN Chunyue

    2017-01-01

    Full Text Available The application of gearshift integral PID controller to air compressor pressure control system is introduced, Its kernel is single chip microcomputer PIC16F877.The design of hardware and solfware are introduced too. Practical application shows that this system has many advantages.

  11. SOIL-AIR PERMEABILITY MEASUREMENT WITH A TRANSIENT PRESSURE BUILDUP METHOD

    Science.gov (United States)

    An analytical solution for transient pressure change in a single venting well was derived from mass conservation of air, Darcy's law of flow in porous media, and the ideal gas law equation of state. Slopes of plots of Pw2 against ln (t+Δt)/Δt similar to Homer's plot were used to ...

  12. Characteristics of atmospheric pressure air discharges with a liquid cathode and a metal anode

    Czech Academy of Sciences Publication Activity Database

    Bruggeman, P.; Ribežl, E.; Degroote, J.; Malesevic, A.; Rego, R.; Vierendeels, J.; Leys, C.; Mašláni, Alan

    2008-01-01

    Roč. 17, č. 2 (2008), s. 1-11 ISSN 0963-0252 Institutional research plan: CEZ:AV0Z20430508 Keywords : atmospheric pressure air discharge * liquid cathode * voltage drop * optical emission spectroscopy Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.685, year: 2008

  13. Enhancements to the hybrid pressurized air receiver (HPAR) concept in the SUNDISC cycle

    Science.gov (United States)

    Heller, Lukas; Hoffmann, Jaap

    2017-06-01

    A dual-pressure air receiver has previously been proposed as part of a hybrid receiver system preheating pressurized air in a solarized gas turbine and providing hot non-pressurized air to power the bottoming cycle of a combined cycle CSP plant. The receiver, based on a bundle of metallic tubular absorbers, was found to not be able to provide the non-pressurized air at the required temperature. Three enhancements to the basic design are presented and thermally modeled: (a) Finned absorber tubes to increase the convective heat transfer, (b) quartz glass elements to alleviate convective losses and improve the flow inside the tube bundle as well as (c) additional absorber elements behind the tube bundle. It could be shown that finned absorber tubes as well as the additional absorber elements have potential to improve the thermal performance of the receiver while a quartz glass window and flow-enhancing quartz elements could be indispensable additions to either of the other enhancements.

  14. Rayleigh-Brillouin scattering profiles of air at different temperatures and pressures

    NARCIS (Netherlands)

    Gu, Z.; Witschas, B.; van der Water, W.; Ubachs, W.M.G.

    2013-01-01

    Rayleigh-Brillouin (RB) scattering profiles for air have been recorded for the temperature range from 255 to 340 K and the pressure range from 640 to 3300 mbar, covering the conditions relevant for the Earth's atmosphere and for planned atmospheric light detection and ranging (LIDAR) missions. The

  15. Compressed-air work is entering the field of high pressures.

    Science.gov (United States)

    Le Péchon, J Cl; Gourdon, G

    2010-01-01

    Since 1850, compressed-air work has been used to prevent shafts or tunnels under construction from flooding. Until the 1980s, workers were digging in compressed-air environments. Since the introduction of tunnel boring machines (TBMs), very little digging under pressure is needed. However, the wearing out of cutter-head tools requires inspection and repair. Compressed-air workers enter the pressurized working chamber only occasionally to perform such repairs. Pressures between 3.5 and 4.5 bar, that stand outside a reasonable range for air breathing, were reached by 2002. Offshore deep diving technology had to be adapted to TBM work. Several sites have used mixed gases: in Japan for deep shaft sinking (4.8 bar), in The Netherlands at Western Scheldt Tunnels (6.9 bar), in Russia for St. Petersburg Metro (5.8 bar) and in the United States at Seattle (5.8 bar). Several tunnel projects are in progress that may involve higher pressures: Hallandsås (Sweden) interventions in heliox saturation up to 13 bar, and Lake Mead (U.S.) interventions to about 12 bar (2010). Research on TBMs and grouting technologies tries to reduce the requirements for hyperbaric works. Adapted international rules, expertise and services for saturation work, shuttles and trained personnel matching industrial requirements are the challenges.

  16. Optimal heat rejection pressure in transcritical carbon dioxide air conditioning and heat pump systems

    DEFF Research Database (Denmark)

    Liao, Shengming; Jakobsen, Arne

    1998-01-01

    Due to the urgent need for environmentally benign refrigerants, the use of the natural substance carbon dioxide in refrigeration systems has gained more and more attention. In systems such as automobile air-conditioners and heat pumps, owing to the relatively high heat rejection temperatures, the...... dioxide air conditioning or heat pump systems and for intelligent controlling such systems.......Due to the urgent need for environmentally benign refrigerants, the use of the natural substance carbon dioxide in refrigeration systems has gained more and more attention. In systems such as automobile air-conditioners and heat pumps, owing to the relatively high heat rejection temperatures......, the cycles using carbon dioxide as refrigerant will have to operate in the transcritical area. In a transcritical carbon dioxide system, there is an optimal heat rejection pressure that gives a maximum COP. In this paper, it is shown that the value of this optimal heat rejection pressure mainly depends...

  17. Effect analysis of air introduced by pressurization on fuel rod performances

    International Nuclear Information System (INIS)

    Ren Qisen; Liu Tong; Sheng Guofu

    2012-01-01

    In the process of pressurization and seal welding, it is common practice to vacuumize before gas filling for the sake of preventing introducing air and other impurities, which would affect the gas composition inside of the fuel rod. However, vacuumization during pressurization is likely not being required sometimes in order to simplify the fabrication procedure. In the present work, based on the AFA3G fuel rod design with 2 MPa of filling gas, analyses on fuel rod performances were carried out under the condition of pressurization with and without vacuumization, respectively. Furthermore, the effect on hydrogen content in fuel rod was preliminarily discussed. Results indicate that the impacts of air composition introduced by pressurization on fuel rod thermal-mechanical performances, such as internal pressure and fuel center temperature, were extremely slight. The gap conductance varies to some extent as a result of the change of gas composition due to air introduced in fuel rod. The impact of humidity on water content in fuel rod is negligible at a low temperature of around 25℃. However, at higher temperature, it is essential to pay attention on the control of fabrication process, and prevent much moisture entering into the fuel rod and increasing the probability of hydriding failure. (authors)

  18. Systematic errors in global air-sea CO2 flux caused by temporal averaging of sea-level pressure

    Directory of Open Access Journals (Sweden)

    H. Kettle

    2005-01-01

    Full Text Available Long-term temporal averaging of meteorological data, such as wind speed and air pressure, can cause large errors in air-sea carbon flux estimates. Other researchers have already shown that time averaging of wind speed data creates large errors in flux due to the non-linear dependence of the gas transfer velocity on wind speed (Bates and Merlivat, 2001. However, in general, wind speed is negatively correlated with air pressure, and a given fractional change in the pressure of dry air produces an equivalent fractional change in the atmospheric partial pressure of carbon dioxide (pCO2air. Thus low pressure systems cause a drop in pCO2air, which together with the associated high winds, promotes outgassing/reduces uptake of CO2 from the ocean. Here we quantify the errors in global carbon flux estimates caused by using monthly or climatological pressure data to calculate pCO2air (and thus ignoring the covariance of wind and pressure over the period 1990-1999, using two common parameterisations for gas transfer velocity. Results show that on average, compared with estimates made using 6 hourly pressure data, the global oceanic sink is systematically overestimated by 7% (W92 and 10% (WM99 when monthly mean pressure is used, and 9% (W92 and 12% (WM99 when climatological pressure is used.

  19. Evaluation of alternating pressure air mattresses: one laboratory-based strategy.

    Science.gov (United States)

    Rithalia, Shyam V

    2004-04-01

    Although many different type of alternating pressure air mattresses (APAMs) are used for the prevention and treatment of pressure ulcers, few high quality randomised controlled trials are available on which to base purchasing decisions. Faced with this situation, physiological measurements are increasingly being used as a surrogate. Laboratory evaluation techniques have centred largely on interface pressure (IP) measurement, typically analysing discrete maximum and minimum levels, or average pressure. However, since pressure relief is time varying, a time-based analysis technique may be more suitable for performance assessment. Measurements of IP, mattress air cell pressure (AP), skin tissue perfusion using laser Doppler fluxmetry (LDF), transcutaneous oxygen (tcPO2) and carbon dioxide (tcPCO2) were taken simultaneously on the sacrum, heels, trochanters and buttock over at least two alternating cycles. Duration of IP below three thresholds (30, 20, and 10 mmHg) as well as the area under the tcPO2, tcPCO2 and LDF curves were calculated automatically. Ten healthy volunteers were recruited to evaluate the pressure-relieving characteristics of two different designs of APAMs. Results indicated significant differences between the products. During the deflation phase of the cycle contact pressures on the heel were significantly lower (p pressure was significantly higher, although there was no significant difference in deflation pressure. Therefore, it is important to note that low APs do not necessarily produce lower IPs under the heel, contrary to the intuitive classical notion. These techniques could assist in the selection of alternating or dynamic surfaces of any description confirmed by further clinical validation.

  20. Reduced injection pressures using a compressed air injection technique (CAIT): an in vitro study.

    Science.gov (United States)

    Tsui, Ban C H; Knezevich, Mark P; Pillay, Jennifer J

    2008-01-01

    High injection pressures have been associated with intraneural injection and persistent neurological injury in animals. Our objective was to test whether a reported simple compressed air injection technique (CAIT) would limit the generation of injection pressures to below a suggested 1,034 mm Hg limit in an in vitro model. After ethics board approval, 30 consenting anesthesiologists injected saline into a semiclosed system. Injection pressures using 30 mL syringes connected to a 22 gauge needle and containing 20 mL of saline were measured for 60 seconds using: (1) a typical "syringe feel" method, and (2) CAIT, thereby drawing 10 mL of air above the saline and compressing this to 5 mL prior to and during injections. All anesthesiologists performed the syringe feel method before introduction and demonstration of CAIT. Using CAIT, no anesthesiologist generated pressures above 1,034 mm Hg, while 29 of 30 produced pressures above this limit at some time using the syringe feel method. The mean pressure using CAIT was lower (636 +/- 71 vs. 1378 +/- 194 mm Hg, P = .025), and the syringe feel method resulted in higher peak pressures (1,875 +/- 206 vs. 715 +/- 104 mm Hg, P = .000). This study demonstrated that CAIT can effectively keep injection pressures under 1,034 mm Hg in this in vitro model. Animal and clinical studies will be needed to determine whether CAIT will allow objective, real-time pressure monitoring. If high pressure injections are proven to contribute to nerve injury in humans, this technique may have the potential to improve the safety of peripheral nerve blocks.

  1. Time-resolved diagnostic of an impulse discharge in variable pressure air

    Science.gov (United States)

    Robledo-Martinez, A.; Sobral, H.; Ruiz-Meza, A.

    2008-09-01

    The effect of gas pressure on the characteristics of a short-gap lightning discharge in air was investigated. For the tests, 70 ns front lightning pulses were applied to a short (11 cm) point-plane gap under variable pressure. The diagnostics employed included electric current and field measurements, spectroscopy in the visible and fast-frame photography. We found that the pressure has a clear effect on the electric field at the plane. For low pressures, the high fields measured (~7 kV cm-1) are comparable to the Laplacian field, indicating that very little ionization takes place in the gap at this pressure; at higher pressures the space charge contributes substantially to the field magnitude. The effect of pressure on the current pulse was, in contrast, minimal; its peak amplitude and shape remained largely unaffected by pressure. Time-resolved spectroscopy allowed the determination of the instantaneous electron density and temperature to be made; the latter, for example, was found to reach 33 000 K at t ~ 1 µs for most of the pressures employed. Using the measured temperature and radius we made estimations of the arc's resistance. We found that the Spitzer resistivity model gives values of resistance that are compatible with the experimental data obtained.

  2. Pressure produced on the residual maxillary alveolar ridge by different impression materials and tray design: an in vivo study.

    Science.gov (United States)

    Reddy, Subash M; Mohan, Chenthil Arun; Vijitha, D; Balasubramanian, R; Satish, A; Kumar, Mahendira

    2013-12-01

    Increased ridge resorption may occur due to inappropriate pressure applied during final impression making phase of complete denture fabrication. This study was done to evaluate the pressure applied on the residual ridge while making impressions with two tray designs (with and without spacer) using, zinc oxide eugenol and light body polyvinyl siloxane impression material. Five edentulous subjects were randomly selected. For each of the five subjects four maxillary final impressions were made and were labelled as, Group A-Impression made with tray without spacer using zinc oxide eugenol impression, Group B-Impression made with tray with spacer using zinc oxide eugenol impression material, Group C-Impression made with tray without spacer using light body polyvinyl siloxane impression material, Group D-Impression made with tray with spacer using light body polyvinyl siloxane impression material. During the impression procedure a closed hydraulic system was used to remotely measure the pressures produced in three areas. The pressure produced were calibrated according to the micro strain record. Statistical comparisons of readings were done using t test and ANOVA. The acquired data revealed that ZOE produced an average pressures value of 26.534 and 72.05 microstrain, while light body PVS produced 11.430 and 37.584 microstrain value with and without spacer respectively. Significantly high values were recorded on the vault of the palate when using trays without spacer. The use of light body polyvinyl siloxane and zinc oxide eugenol impression material showed insignificant difference. Within the limitations of this study, tray design has a significantly effected on the pressures produced, while the impression materials does not have any significant difference.

  3. Treatment and use of air pollution control residues from MSW incineration: an overview.

    Science.gov (United States)

    Quina, Margarida J; Bordado, João C; Quinta-Ferreira, Rosa M

    2008-11-01

    This work reviews strategies for the management of municipal solid waste incineration (MSWI) residues, particularly solid particles collected from flue gases. These tiny particles may be retained by different equipment, with or without additives (lime, activated carbon, etc.), and depending on the different possible combinations, their properties may vary. In industrial plants, the most commonly used equipment for heat recovery and the cleaning of gas emissions are: heat recovery devices (boiler, superheater and economiser); dry, semidry or wet scrubbers; electrostatic precipitators; bag filters; fabric filters, and cyclones. In accordance with the stringent regulations in force in developed countries, these residues are considered hazardous, and therefore must be treated before being disposed of in landfills. Nowadays, research is being conducted into specific applications for these residues in order to prevent landfill practices. There are basically two possible ways of handling these residues: landfill after adequate treatment or recycling as a secondary material. The different types of treatment may be grouped into three categories: separation processes, solidification/stabilization, and thermal methods. These residues generally have limited applications, mainly due to the fact that they tend to contain large quantities of soluble salts (NaCl, KCl, calcium compounds), significant amounts of toxic heavy metals (Pb, Zn, Cr, Cu, Ni, Cd) in forms that may easily leach out, and trace quantities of very toxic organic compounds (dioxin, furans). The most promising materials for recycling this residue are ceramics and glass-ceramic materials. The main purpose of the present paper is to review the published literature in this field. A range of studies have been summarized in a series of tables focusing upon management strategies used in various countries, waste composition, treatment processes and possible applications.

  4. Effects of thermal treatment on mineralogy and heavy metal behavior in iron oxide stabilized air pollution control residues

    DEFF Research Database (Denmark)

    Sørensen, Mette Abildgaard; Bender-Koch, C.; Starckpoole, M. M.

    2000-01-01

    Stabilization of air pollution control residues by coprecipitation with ferrous iron and subsequent thermal treatment (at 600 and 900 °C) has been examined as a means to reduce heavy metal leaching and to improve product stability. Changes in mineralogy and metal binding were analyzed using various...... volatilized or destabilized with respect to leaching. Pb, in particular, exhibited increased reactivity following the formation of an ordered iron oxide structure at 900 °C. The thermal treatment had a positive effect on Cr release, which was reduced significantly at 900 °C in the presence of organic matter...

  5. Investigation of hydrophobic substrates for solution residue analysis utilizing an ambient desorption liquid sampling-atmospheric pressure glow discharge microplasma.

    Science.gov (United States)

    Paing, Htoo W; Marcus, R Kenneth

    2018-03-12

    A practical method for preparation of solution residue samples for analysis utilizing the ambient desorption liquid sampling-atmospheric pressure glow discharge optical emission spectroscopy (AD-LS-APGD-OES) microplasma is described. Initial efforts involving placement of solution aliquots in wells drilled into copper substrates, proved unsuccessful. A design-of-experiment (DOE) approach was carried out to determine influential factors during sample deposition including solution volume, solute concentration, number of droplets deposited, and the solution matrix. These various aspects are manifested in the mass of analyte deposited as well as the size/shape of the product residue. Statistical analysis demonstrated that only those initial attributes were significant factors towards the emission response of the analyte. Various approaches were investigated to better control the location/uniformity of the deposited sample. Three alternative substrates, a glass slide, a poly(tetrafluoro)ethylene (PTFE) sheet, and a polydimethylsiloxane (PDMS)-coated glass slide, were evaluated towards the microplasma analytical performance. Co-deposition with simple organic dyes provided an accurate means of determining the location of the analyte with only minor influence on emission responses. The PDMS-coated glass provided the best performance by virtue of its providing a uniform spatial distribution of the residue material. This uniformity yielded an improved limits of detection by approximately 22× for 20 μL and 4 x for 2 μL over the other two substrates. While they operate by fundamentally different processes, this choice of substrate is not restricted to the LS-APGD, but may also be applicable to other AD methods such as DESI, DART, or LIBS. Further developments will be directed towards a field-deployable ambient desorption OES source for quantitative analysis of microvolume solution residues of nuclear forensics importance.

  6. An investigation on the effects of air on electron energy in atmospheric pressure helium plasma jets

    Science.gov (United States)

    Liu, Yadi; Tan, Zhenyu; Chen, Xinxian; Li, Xiaotong; Zhang, Huimin; Pan, Jie; Wang, Xiaolong

    2018-03-01

    In this work, the effects of air on electron energy in the atmospheric pressure helium plasma jet produced by a needle-plane discharge system have been investigated by means of the numerical simulation based on a two-dimensional fluid model, and the air concentration dependences of the reactive species densities have also been calculated. In addition, the synergistic effects of the applied voltage and air concentration on electron energy have been explored. The present work gives the following significant results. For a fixed applied voltage, the averaged electron energy is basically a constant at air concentrations below about 0.5%, but it evidently decreases above the concentration of 0.5%. Furthermore, the averaged densities of four main reactive species O, O(1D), O2(1Δg), and N2(A3Σu+) increase with the increasing air concentration, but the increase becomes slow at air concentrations above 0.5%. The air concentration dependences of the averaged electron energy under different voltage amplitudes are similar, and for a given air concentration, the averaged electron energy increases with the increase in the voltage amplitude. For the four reactive species, the effects of the air concentration on their averaged densities are similar for a given voltage amplitude. In addition, the averaged densities of the four reactive species increase with increasing voltage amplitude for a fixed air concentration. The present work suggests that a combination of high voltage amplitude and the characteristic air concentration, 0.5% in the present discharge system, allows an expected electron energy and also generates abundant reactive species.

  7. Experimental investigation of wettability alteration on residual oil saturation using nonionic surfactants: Capillary pressure measurement

    Directory of Open Access Journals (Sweden)

    Masoud Amirpour

    2015-12-01

    Full Text Available Introducing the novel technique for enhancing oil recovery from available petroleum reservoirs is one of the important issues in future energy demands. Among of all operative factors, wettability may be the foremost parameter affecting residual oil saturation in all stage of oil recovery. Although wettability alteration is one of the methods which enhance oil recovery from the petroleum reservoir. Recently, the studies which focused on this subject were more than the past and many contributions have been made on this area. The main objective of the current study is experimentally investigation of the two nonionic surfactants effects on altering wettability of reservoir rocks. Purpose of this work is to change the wettability to preferentially the water-wet condition. Also reducing the residual oil saturation (Sor is the other purpose of this work. The wettability alteration of reservoir rock is measured by two main quantitative methods namely contact angle and the USBM methods. Results of this study showed that surfactant flooding is more effective in oil-wet rocks to change their wettability and consequently reducing Sor to a low value. Cedar (Zizyphus Spina Christi is low priced, absolutely natural, and abundantly accessible in the Middle East and Central Asia. Based on the results, this material can be used as a chemical surfactant in field for enhancing oil recovery.

  8. Gas bubble dimensions in Archean lava flows indicate low air pressure at 2.7 Ga

    Science.gov (United States)

    Som, S. M.; Buick, R.; Hagadorn, J.; Blake, T.; Perreault, J.; Harnmeijer, J.; Catling, D. C.

    2014-12-01

    Air pressure constrains atmospheric composition, which, in turn, is linked to the Earth system through biogeochemical cycles and fluxes of volatiles from and to the Earth's interior. Previous studies have only placed maximum levels on surface air pressure for the early Earth [1]. Here, we calculate an absolute value for Archean barometric pressure using gas bubble size (vesicle) distributions in uninflated basaltic lava flows that solidified at sea level 2.7 billion years ago in the Pilbara Craton, Western Australia. These vesicles have been filled in by secondary minerals deposited during metasomatism and so are now amydules, but thin sections show that infilling did not change vesicle dimensions. Amygdule dimensions are measured using high-resolution X-ray tomography from core samples obtained from the top and bottom of the lava flows. The modal size expressed at the top and at the bottom of an uninflated flow can be linked to atmospheric pressure using the ideal gas law. Such a technique has been verified as a paleoaltimeter using Hawaiian Quaternary lava flows [2]. We use statistical methods to estimate the mean and standard deviation of the volumetric size of the amygdules by applying 'bootstrap'resampling and the Central Limit Theorem. Our data indicate a surprisingly low atmospheric pressure. Greater nitrogen burial under anaerobic conditions likely explains lower pressure. Refs: [1] Som et al. (2012) Nature 484, 359-262. D. L. Sahagian et al. (2002) J. Geol., 110, 671-685.

  9. Calibrating airborne measurements of airspeed, pressure and temperature using a Doppler laser air-motion sensor

    Directory of Open Access Journals (Sweden)

    W. A. Cooper

    2014-09-01

    Full Text Available A new laser air-motion sensor measures the true airspeed with a standard uncertainty of less than 0.1 m s−1 and so reduces uncertainty in the measured component of the relative wind along the longitudinal axis of the aircraft to about the same level. The calculated pressure expected from that airspeed at the inlet of a pitot tube then provides a basis for calibrating the measurements of dynamic and static pressure, reducing standard uncertainty in those measurements to less than 0.3 hPa and the precision applicable to steady flight conditions to about 0.1 hPa. These improved measurements of pressure, combined with high-resolution measurements of geometric altitude from the global positioning system, then indicate (via integrations of the hydrostatic equation during climbs and descents that the offset and uncertainty in temperature measurement for one research aircraft are +0.3 ± 0.3 °C. For airspeed, pressure and temperature, these are significant reductions in uncertainty vs. those obtained from calibrations using standard techniques. Finally, it is shown that although the initial calibration of the measured static and dynamic pressures requires a measured temperature, once calibrated these measured pressures and the measurement of airspeed from the new laser air-motion sensor provide a measurement of temperature that does not depend on any other temperature sensor.

  10. 42 CFR 84.157 - Airflow resistance test; Type C supplied-air respirator, pressure-demand class; minimum...

    Science.gov (United States)

    2010-10-01

    ... test; Type C supplied-air respirator, pressure-demand class; minimum requirements. (a) The static... 42 Public Health 1 2010-10-01 2010-10-01 false Airflow resistance test; Type C supplied-air respirator, pressure-demand class; minimum requirements. 84.157 Section 84.157 Public Health PUBLIC HEALTH...

  11. Traffic-related air pollution and noise and children's blood pressure : Results from the PIAMA birth cohort study

    NARCIS (Netherlands)

    Bilenko, Natalya; van Rossem, Lenie; Brunekreef, Bert; Beelen, Rob; Eeftens, Marloes; Hoek, Gerard; Houthuijs, Danny; de Jongste, Johan C.; van Kempen, Elise; Koppelman, Gerard H.; Meliefste, Kees; Oldenwening, Marieke; Smit, Henriette A.; Wijga, Alet H.; Gehring, Ulrike

    Aims Elevation of a child's blood pressure may cause possible health risks in later life. There is evidence for adverse effects of exposure to air pollution and noise on blood pressure in adults. Little is known about these associations in children. We investigated the associations of air pollution

  12. Traffic-related air pollution and noise and children's blood pressure : Results from the PIAMA birth cohort study

    NARCIS (Netherlands)

    Bilenko, Natalya; Van Rossem, Lenie|info:eu-repo/dai/nl/330805436; Brunekreef, Bert|info:eu-repo/dai/nl/067548180; Beelen, Rob; Eeftens, Marloes; Hoek, Gerard; Houthuijs, Danny; De Jongste, Johan C.; Van Kempen, Elise; Koppelman, Gerard H.; Meliefste, Kees; Oldenwening, Marieke; Smit, Henriette A.|info:eu-repo/dai/nl/067730043; Wijga, Alet H.; Gehring, Ulrike

    2015-01-01

    Aims: Elevation of a child's blood pressure may cause possible health risks in later life. There is evidence for adverse effects of exposure to air pollution and noise on blood pressure in adults. Little is known about these associations in children. We investigated the associations of air pollution

  13. A Comparative Study of Sound Speed in Air at Room Temperature between a Pressure Sensor and a Sound Sensor

    Science.gov (United States)

    Amrani, D.

    2013-01-01

    This paper deals with the comparison of sound speed measurements in air using two types of sensor that are widely employed in physics and engineering education, namely a pressure sensor and a sound sensor. A computer-based laboratory with pressure and sound sensors was used to carry out measurements of air through a 60 ml syringe. The fast Fourier…

  14. Characteristics of atmospheric pressure plasma jets emerging into ambient air and helium

    International Nuclear Information System (INIS)

    Zhu Wenchao; Li Qing; Zhu Ximing; Pu Yikang

    2009-01-01

    An investigation of atmospheric pressure helium plasma jets emerging into ambient air and helium was carried out with the aim of shedding light on the mechanism for the formation of extended plasma plumes. By electron multiplying charge coupled device imaging, it is shown that the geometrical shape of the jet in ambient helium is not an arrow-like shape as that in ambient air, but a diffusive one. In ambient helium, the jet length increased continuously with the applied voltage. For ambient air, the jet length was determined by both the helium flow rate and the applied voltage. In addition, the N 2 (C-B) band and the N 2 + lines dominate the emission spectra of the jet in ambient air. The Penning ionization between metastable He atoms and N 2 molecular may be the main source of N 2 + . (fast track communication)

  15. Incinerator performance: effects of changes in waste input and furnace operation on air emissions and residues

    DEFF Research Database (Denmark)

    Astrup, Thomas; Riber, Christian; Pedersen, Anne Juul

    2011-01-01

    and residue composition at a full-scale incinerator were affected by known additions of specific waste materials to the normal municipal solid waste (MSW) input. Six individual experiments were carried out (% ww of total waste input): NaCl (0.5%), shoes (1.6%), automobile shredder waste (14%), batteries (0...

  16. Calculating osmotic pressure of xylitol solutions from molality according to UNIFAC model and measuring it with air humidity osmometry.

    Science.gov (United States)

    Yu, Lan; Zhan, Tingting; Zhan, Xiancheng; Wei, Guocui; Tan, Xiaoying; Wang, Xiaolan; Li, Chengrong

    2014-11-01

    The osmotic pressure of xylitol solution at a wide concentration range was calculated according to the UNIFAC model and experimentally determined by our newly reported air humidity osmometry. The measurements from air humidity osmometry were compared with UNIFAC model calculations from dilute to saturated solution. Results indicate that air humidity osmometry measurements are comparable to UNIFAC model calculations at a wide concentration range by two one-sided test and multiple testing corrections. The air humidity osmometry is applicable to measure the osmotic pressure and the osmotic pressure can be calculated from the concentration.

  17. 42 CFR 84.163 - Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand...

    Science.gov (United States)

    2010-10-01

    ... for gases and vapors; Type C supplied-air respirators, demand and pressure-demand classes; test... ......do ......do The air-supply hose, detachable coupling, and demand valve of the demand class or pressure-demand valve of the pressure-demand class for Type C supplied-air respirators, demand and pressure...

  18. Can we trust intraocular pressure measurements in eyes with intracameral air?

    Science.gov (United States)

    Jóhannesson, Gauti; Lindén, Christina; Eklund, Anders; Behndig, Anders; Hallberg, Per

    2014-10-01

    To evaluate the effect of intracameral air on intraocular pressure (IOP) measurements using Goldmann applanation tonometry (GAT) and applanation resonance tonometry (ART) in an in-vitro porcine eye model. IOP was measured on thirteen freshly enucleated eyes at three reference pressures: 20, 30, and 40 mmHg. Six measurements/method were performed in a standardized order with GAT and ART respectively. Air was injected intracamerally in the same manner as during Descemet's stripping endothelial keratoplasty (DSEK) and Descemet's membrane endothelial keratoplasty (DMEK), and the measurements were repeated. Measured IOP increased significantly for both tonometry methods after air injection: 0.7 ± 2.1 mmHg for GAT and 10.6 ± 4.9 mmHg for ART. This difference was significant at each reference pressure for ART but not for GAT. Although slightly affected, this study suggests that we can trust GAT IOP-measurements in eyes with intracameral air, such as after DSEK/DMEK operations. Ultrasound-based methods such as ART should not be used.

  19. Elevated Plasma Endothelin-1 and Pulmonary Arterial Pressure in Children Exposed to Air Pollution

    Science.gov (United States)

    Calderón-Garcidueñas, Lilian; Vincent, Renaud; Mora-Tiscareño, Antonieta; Franco-Lira, Maricela; Henríquez-Roldán, Carlos; Barragán-Mejía, Gerardo; Garrido-García, Luis; Camacho-Reyes, Laura; Valencia-Salazar, Gildardo; Paredes, Rogelio; Romero, Lina; Osnaya, Hector; Villarreal-Calderón, Rafael; Torres-Jardón, Ricardo; Hazucha, Milan J.; Reed, William

    2007-01-01

    Background Controlled exposures of animals and humans to particulate matter (PM) or ozone air pollution cause an increase in plasma levels of endothelin-1, a potent vasoconstrictor that regulates pulmonary arterial pressure. Objectives The primary objective of this field study was to determine whether Mexico City children, who are chronically exposed to levels of PM and O3 that exceed the United States air quality standards, have elevated plasma endothelin-1 levels and pulmonary arterial pressures. Methods We conducted a study of 81 children, 7.9 ± 1.3 years of age, lifelong residents of either northeast (n = 19) or southwest (n = 40) Mexico City or Polotitlán (n = 22), a control city with PM and O3 levels below the U.S. air quality standards. Clinical histories, physical examinations, and complete blood counts were done. Plasma endothelin-1 concentrations were determined by immunoassay, and pulmonary arterial pressures were measured by Doppler echocardiography. Results Mexico City children had higher plasma endothelin-1 concentrations compared with controls (p < 0.001). Mean pulmonary arterial pressure was elevated in children from both northeast (p < 0.001) and southwest (p < 0.05) Mexico City compared with controls. Endothelin-1 levels in Mexico City children were positively correlated with daily outdoor hours (p = 0.012), and 7-day cumulative levels of PM air pollution < 2.5 μm in aerodynamic diameter (PM2.5) before endothelin-1 measurement (p = 0.03). Conclusions Chronic exposure of children to PM2.5 is associated with increased levels of circulating endothelin-1 and elevated mean pulmonary arterial pressure. PMID:17687455

  20. Influence of arc current and pressure on non-chemical equilibrium air arc behavior

    Science.gov (United States)

    Yi, WU; Yufei, CUI; Jiawei, DUAN; Hao, SUN; Chunlin, WANG; Chunping, NIU

    2018-01-01

    The influence of arc current and pressure on the non-chemical equilibrium (non-CE) air arc behavior of a nozzle structure was investigated based on the self-consistent non-chemical equilibrium model. The arc behavior during both the arc burning and arc decay phases were discussed at different currents and different pressures. We also devised the concept of a non-equilibrium parameter for a better understanding of non-CE effects. During the arc burning phase, the increasing current leads to a decrease of the non-equilibrium parameter of the particles in the arc core, while the increasing pressure leads to an increase of the non-equilibrium parameter of the particles in the arc core. During the arc decay phase, the non-CE effect will decrease by increasing the arc burning current and the nozzle pressure. Three factors together—convection, diffusion and chemical reactions—influence non-CE behavior.

  1. 42 CFR 84.149 - Type C supplied-air respirator, demand and pressure demand class; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Type C supplied-air respirator, demand and pressure demand class; minimum requirements. 84.149 Section 84.149 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT... OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.149 Type C supplied-air respirator...

  2. Treatment and use of air pollution control residues from MSW incineration: An overview

    OpenAIRE

    Quina, Margarida J.; Bordado, João C.; Quinta-Ferreira, Rosa M.

    2008-01-01

    This work reviews strategies for the management of municipal solid waste incineration (MSWI) residues, particularly solid particles collected from flue gases. These tiny particles may be retained by different equipment, with or without additives (lime, activated carbon, etc.), and depending on the different possible combinations, their properties may vary. In industrial plants, the most commonly used equipment for heat recovery and the cleaning of gas emissions are: heat recovery devices (boi...

  3. Extraction and detection of pesticide residues from air filter inserts using supercritical carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Zemanian, T.S.; Robins, W.H.; Lee, R.N.; Wright, B.W.

    1994-10-01

    Trace quantities of airborne herbicide residues were collected on adsorbent bed cartridges and were subsequently extracted from the adsorbent using supercritical carbon dioxide. An apparatus was constructed to facilitate the extraction and recovery of the desired analytes. The resulting extracts were analyzed using gas chromatography/mass spectrometry (GC/MS) or high performance liquid chromatography (HPLC) techniques. Results are presented for a series of analytes representative of common commercial pesticides or herbicides.

  4. Characterization of Rio Blanco retort 1 water following treatment by lime-soda softening and reverse osmosis; Residual brine treated by wet-air oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Kocornik, D.; Renk, R.

    1986-09-01

    Laboratory research has been conducted to evaluate the chemical, physical, and toxicological characteristics of treated and untreated water pumped from the flooded modified in situ retort at lease tract C-a. This wastewater had a total dissolved solids (TDS) content of about 5450 mg/L and a total organic carbon content of about 16 mg/L. Wet chemical analyses, metals analyses, particle-size analyses, and MICROTOX assays were performed on the wastewater before and after treatment by lime-soda softening and reverse osmosis. The reverse osmosis membrane used in this research was a Filmtec model SW30-2521 spiral-wound polyamide unit. In a short duration test at a TDS of 21,800 mg/L, the reverse osmosis system successfully removed dissolved solids and organics from the wastewater. The water was also much less toxic to the MICROTOX organism after treatment by reverse osmosis. Membrane fouling was observed when water with a TDS of 54,500 mg/L was treated. Treatment of the reverse osmosis residual brine was attempted by subcritical wet-air oxidation. The brine remaining after the 170-hour test on the water with a TDS of 5450 mg/L was subjected to temperatures ranging from 204/sup 0/C (400/sup 0/F) to 315/sup 0/C (600/sup 0/F) and pressures from 500 to 1600 psig for approximately 30 minutes. The waste treated by the higher temperatures and pressures showed good removals of organics, nitrogen compounds, and some metals. The sample treated at 302/sup 0/C (575/sup 0/F) and 1300 psi was assayed for MICROTOX response and no toxicity was measured. The reverse osmosis brine was significantly toxic to the MICROTOX organism before treatment by subcritical wet-air oxidation. 14 refs., 8 figs., 14 tabs.

  5. Evaluation of pressure response in the Los Alamos controlled air incinerator during three incident scenarios

    International Nuclear Information System (INIS)

    Vavruska, J.S.; Elsberry, K.; Thompson, T.K.; Pendergrass, J.A.

    1996-01-01

    The Los Alamos Controlled Air Incinerator (CAI) is a system designed to accept radioactive mixed waste containing alpha-emitting radionuclides. A mathematical model was developed to predict the pressure response throughout the offgas treatment system of the CAI during three hypothetical incident scenarios. The scenarios examined included: (1) loss of burner flame and failure of the flame safeguard system with subsequent reignition of fuel gas in the primary chamber, (2) pyrolytic gas buildup from a waste package due to loss of induced draft and subsequent restoration of induced draft, and (3) accidental charging of propellant spray cans in a solid waste package to the primary chamber during a normal feed cycle. For each of the three scenarios, the finite element computer model was able to determine the transient pressure surge and decay response throughout the system. Of particular interest were the maximum absolute pressures attainable at critical points in the system as well as maximum differential pressures across the high efficiency particulate air (HEPA) filters. Modeling results indicated that all three of the scenarios resulted in maximum HEPA filter differential pressures well below the maximum allowable levels

  6. Translational, rotational and vibrational temperatures of a gliding arc discharge at atmospheric pressure air

    DEFF Research Database (Denmark)

    Zhu, Jiajian; Gao, Jinlong; Ehn, Andreas

    2014-01-01

    Gliding arc discharges have generally been used to generate non-equilibrium plasma at atmospheric pressure. Temperature distributions of a gliding arc are of great interest both for fundamental plasma research and for practical applications. In the presented studies, translational, rotational...... and vibrational temperatures of a gliding arc generated at atmospheric pressure air are investigated. Translational temperatures (about 1100 K) were measured by laser-induced Rayleigh scattering, and two-dimensional temperature imaging was performed. Rotational and vibrational temperatures (about 3600 K and 6700...

  7. Determination of air and hydrofoil pressure coefficient by laser doppler anemometry

    Directory of Open Access Journals (Sweden)

    Ristić Slavica S.

    2010-01-01

    Full Text Available Some results of experiments performed in water cavitation tunnel are presented. Pressure coefficient (Cp was experimentally determined by Laser Doppler Anemometry (LDA measurements. Two models were tested: model of airplane G4 (Super Galeb and hydrofoil of high speed axial pump. These models are not prepared for conventional pressure measurements, so that LDA is applied for Cp determination. Numerical results were obtained using a code for average Navier-Stokes equations solutions. Comparisons between computational and experimental results prove the effectiveness of the LDA. The advantages and disadvantages of LDA application are discussed. Flow visualization was made by air bubbles.

  8. Element composition and mineralogical characterisation of air pollution control residue from UK energy-from-waste facilities.

    Science.gov (United States)

    Bogush, Anna; Stegemann, Julia A; Wood, Ian; Roy, Amitava

    2015-02-01

    Air pollution control (APC) residues from energy-from-waste (EfW) are alkaline (corrosive) and contain high concentrations of metals, such as zinc and lead, and soluble salts, such as chlorides and sulphates. The EPA 3050B-extractable concentrations of 66 elements, including critical elements of strategic importance for advanced electronics and energy technologies, were determined in eight APC residues from six UK EfW facilities. The concentrations of Ag (6-15 mg/kg) and In (1-13 mg/kg), as well as potential pollutants, especially Zn (0.26-0.73 wt.%), Pb (0.05-0.2 wt.%), As, Cd, Cu, Mo, Sb, Sn and Se were found to be enriched in all APC residues compared to average crustal abundances. Results from a combination of scanning electron microscopy with energy dispersive X-ray spectroscopy and also powder X-ray diffraction, thermal analysis and Fourier transform infrared spectroscopy give an exceptionally full understanding of the mineralogy of these residues, which is discussed in the context of other results in the literature. The present work has shown that the bulk of the crystalline phases present in the investigated APC residues include Ca-based phases, such as CaCl(x)OH(2-x), CaCO3, Ca(OH)2, CaSO4, and CaO, as well as soluble salts, such as NaCl and KCl. Poorly-crystalline aragonite was identified by FTIR. Sulphur appears to have complex redox speciation, presenting as both anhydrite and hannebachite in some UK EfW APC residues. Hazardous elements (Zn and Pb) were widely associated with soluble Ca- and Cl-bearing phases (e.g. CaCl(x)OH(2-x) and sylvite), as well as unburnt organic matter and aluminosilicates. Specific metal-bearing minerals were also detected in some samples: e.g., Pb present as cerussite; Zn in gahnite, zincowoodwardite and copper nickel zinc oxide; Cu in tenorite, copper nickel zinc oxide and fedotovite. Aluminium foil pieces were present and abundantly covered by fine phases, particularly in any cracks, probably in the form of Friedel's salt

  9. Determination of chlorantraniliprole residues in crops by liquid chromatography coupled with atmospheric pressure chemical ionization mass spectrometry/mass spectrometry.

    Science.gov (United States)

    Grant, Joann; Rodgers, Carol A; Chickering, Clark D; Hill, Sidney J; Stry, James J

    2010-01-01

    An analytical method is presented for the determination of chlorantraniliprole residues in crops. Chlorantraniliprole residues were extracted from crop matrixes with acetonitrile after a water soak. The extracts were passed through a strong anion-exchange (SAX) SPE cartridge stacked on top of a reversed-phase (RP) polymer cartridge. After both cartridges were rinsed and vacuum-dried, the SAX cartridge was removed, and chlorantraniliprole was eluted from the RP polymer cartridge with acetonitrile. The acetonitrile eluate was evaporated to dryness, reconstituted, and analyzed using an LC/MS/MS instrument equipped with an atmospheric pressure chemical ionization source. The method was successfully validated at 0.010, 0.10, and 10 mg/kg for the following crop matrixes: potatoes, sugar beets (tops), lettuce, broccoli, soybeans, soybean forage, tomatoes, cucumbers, oranges, apples, pears, peaches, almonds (nutmeat), rice grain, wheat grain, wheat hay, corn stover, alfalfa forage, cottonseed, grapes, and corn grain. The average recoveries from all crop samples fortified at the method LOQ ranged from 91 to 108%, with an overall average recovery of 97%. The average recoveries from all crop samples fortified at 10 times the method LOQ ranged from 89 to 115%, with an overall average recovery of 101%. For all of the fortified control samples analyzed in this study, the overall average recovery was 99%.

  10. Parameters of a supershort avalanche electron beam generated in atmospheric-pressure air

    Science.gov (United States)

    Tarasenko, V. F.

    2011-05-01

    Conditions under which the number of runaway electrons in atmospheric-pressure air reaches ˜5 × 1010 are determined. Recommendations for creating runaway electron accelerators are given. Methods for measuring the parameters of a supershort avalanche electron beam and X-ray pulses from gas-filled diodes, as well as the discharge current and gap voltage, are described. A technique for determining the instant of runaway electron generation with respect to the voltage pulse is proposed. It is shown that the reduction in the gap voltage and the decrease in the beam current coincide in time. The mechanism of intense electron beam generation in gas-filled diodes is analyzed. It is confirmed experimentally that, in optimal regimes, the number of electrons generated in atmospheric-pressure air with energies T > eU m , where U m is the maximum gap voltage, is relatively small.

  11. Influence of venting areas on the air blast pressure inside tubular structures like railway carriages.

    Science.gov (United States)

    Larcher, Martin; Casadei, Folco; Solomos, George

    2010-11-15

    In case of a terrorist bomb attack the influence and efficiency of venting areas in tubular structures like train carriages is of interest. The pressure-time function of an air blast wave resulting from a solid charge is first compared to that of a gas or dust explosion and the capability of a venting structure to fly away is assessed. Several calculations using fluid-structure interaction are performed, which show that after a certain distance from the explosion, the air blast wave inside a tubular structure becomes one-dimensional, and that the influence of venting areas parallel to the wave propagation direction is small. The pressure peak and the impulse at certain points in a tubular structure are compared for several opening sizes. The overall influence of realistic size venting devices remains moderate and their usefulness in mitigating internal explosion effects in trains is discussed. Copyright © 2010 Elsevier B.V. All rights reserved.

  12. An analysis of the loss of residual heat removal system event for pressurized what reactor at reduced inventory operation

    International Nuclear Information System (INIS)

    Han, Kee Soo; Song, Jin Ho

    1995-01-01

    The loss of Residual Heat Removal System(RHRS) event during reduced inventory operation for the Korean Standard Nuclear Power Plants(KSNPPs) is simulated by RELAP5/MOD3 and RELAP5/MOD3.1. Two cases are considered; Base case for an intact Reactor Coolant System(RCS)with no vent and a vent case for an open system. Comparative simulations of base case are performed by RELAP5/MOD3 and RELAP5/MOD3.1 computer codes. The results of two simulations are generally in good qualitative and quantitative agreement. However since the results of RELAP5/MOD3 simulation reveals the deficiency of RELAP5/MOD3 wall heat model, the RELAP5/MOD3.1 computer code is used for the simulation of the vent case. The analysis results of base case show that two steam generators are insufficient to remove decay heat at one day after shutdown, where the RCS is closed. The RCS pressure increased continuously and reached the RCS temporary boundaries design pressure of 0.24 MP a around 4,000 seconds. In the vent case with a flow capacity equivalent to three times the capacity of Pressurizer safety Valve(PSV), it is shown that the RCS pressure does not reach 0.24 Mpa and core uncovery does not occur until 10,000 seconds. The detailed discussions on the results of this study suggest the feasibility of RELAP5/MOD3.1 as an analysis tool for the simulation of the loss of RHRS event at reduced inventory operation. The results of this study also provided insight for the determination of proper vent capacity. 17 figs., 6 tabs., 7 refs. (Author)

  13. A multi-residue method for characterization of endocrine disruptors in gaseous and particulate phases of ambient air

    Science.gov (United States)

    Alliot, Fabrice; Moreau-Guigon, Elodie; Bourges, Catherine; Desportes, Annie; Teil, Marie-Jeanne; Blanchard, Martine; Chevreuil, Marc

    2014-08-01

    A number of semi-volatile compounds occur in indoor air most of them being considered as potent endocrine disruptors and thus, exerting a possible impact upon health. To assess their concentration levels in indoor air, we developed and validated a method for sampling and multi-residue analysis of 58 compounds including phthalates, polycyclic aromatic hydrocarbons (PAHs), polybromodiphenylethers (PBDEs), polychlorobiphenyls (PCBs), parabens, bisphenol A (BPA) and tetrabromobisphenol A (TBBPA) in gaseous and particulate phases of air. We validated each step of procedures from extraction until analysis. Matrice spiking were performed at extraction, fractionation and purification stages. The more volatile compounds were analyzed with a gas chromatography system coupled with a mass spectrometer (GC/MS) or with a tandem mass spectrometer (GC/MS/MS). The less volatile compounds were analyzed with a liquid chromatography system coupled with a tandem mass spectrometer (LC/MS/MS). Labeled internal standard method was used ensuring high quantification accuracy. The instrumental detection limits were under 1 pg for all compounds and therefore, a limit of quantification averaging 1 pg m-3 for the gaseous and the particulate phases and a volume of 150 m3, except for phthalates, phenol compounds and BDE-209. Satisfactory recoveries were found except for phenol compounds. That method was successfully applied to several indoor air samples (office, apartment and day nursery) and most of the targeted compounds were quantified, mainly occurring in the gaseous phase. The most abundant were phthalates (up to 918 ng m-3 in total air), followed by PCBs > parabens > BPA > PAHs > PBDEs.

  14. Calculation of the net emission coefficient of an air thermal plasma at very high pressure

    International Nuclear Information System (INIS)

    Billoux, T; Cressault, Y; Teulet, Ph; Gleizes, A

    2012-01-01

    The aim of this paper is to present an accurate evaluation of the phenomena appearing for high pressure air plasmas supposed to be in local thermodynamic equilibrium (LTE). In the past, we already calculated the net emission coefficient for air mixtures at atmospheric pressure and for temperatures up to 30kK (molecular contribution being restricted to 10kK). Unfortunately, the existence of high pressures does not allow us to use this database due to the non-ideality of the plasma (Viriel and Debye corrections, energy cut-off ...), and due to the significant shifts of molecular reactions towards upper temperatures. Consequently, this paper proposes an improvement of our previous works with a consideration of high pressure corrections in the composition algorithm in order to take into account the pressure effects, and with a new calculation of all the contributions of the plasma radiation (atomic lines and continuum, molecular continuum, and molecular bands) using an updated database. A particular attention is paid to calculate the contribution of all the major molecular band systems to the radiation: O 2 (Schumann–Runge), N 2 (VUV, 1st and 2nd positive), NO (IR, β, γ, δ, element of ) and N 2 + (1st negative and Meinel). The discrete atomic lines and molecular bands radiation including the overlapping are calculated by a line-by-line method up to 30kK and 100 bar. This updated database is validated in the case of optically thin plasmas and pressure of 1bar by the comparison of our integrated emission strength with the published results. Finally, this work shows the necessity to extend the molecular radiation database up to 15kK at high pressure (bands and continuum) since their corresponding contributions could not be neglected at high temperature.

  15. Characterization of an atmospheric pressure air plasma source for polymer surface modification

    Science.gov (United States)

    Yang, Shujun; Tang, Jiansheng

    2013-10-01

    An atmospheric pressure air plasma source was generated through dielectric barrier discharge (DBD). It was used to modify polyethyleneterephthalate (PET) surfaces with very high throughput. An equivalent circuit model was used to calculate the peak average electron density. The emission spectrum from the plasma was taken and the main peaks in the spectrum were identified. The ozone density in the down plasma region was estimated by Absorption Spectroscopy. NSF and ARC-ODU

  16. Blood pressure and particulate air pollution in schoolchildren of Lahore, Pakistan.

    Science.gov (United States)

    Sughis, Muhammad; Nawrot, Tim S; Ihsan-ul-Haque, Syed; Amjad, Asad; Nemery, Benoit

    2012-05-25

    Air pollution is a growing health problem for urban populations in emerging economies. The present study examines the (cross-sectional) relation between blood pressure and particulate air pollution in schoolchildren of Lahore (Pakistan). We recruited a sample of 8-12 year-old children (mean age 9.9 years; 45% girls) from two schools in Lahore situated in areas with low (n = 79) and high (n = 100) air pollution, respectively. During the study period (January-April 2009) particulate pollution [PM(10) and PM(2.5) i.e. particles with aerodynamic diameters below 10 μm or 2.5 μm, respectively] was measured at the school sites with a laser operated device (Metone Aerocet 531). Blood pressure was measured, after 5 minutes of sitting rest, using an automated device (average of 5 consecutive measurements). Spot urine samples were also collected and concentrations of Na and K were measured. Mean daily values of PM2.5 were 28.5 μg/m(3) (SD: 10.3) and 183 μg/m(3) (SD: 30.2), in the low and high pollution areas, respectively. Systolic and diastolic blood pressure were significantly higher in children living in the high pollution area (115.9/70.9 mm Hg) than in the low pollution area (108.3/66.4 mm Hg), independently of age, gender, height, weight, socio-economic status, passive smoking and the urinary concentrations of Na, K, and creatinine. In 8-12 year-old children, exposure to (traffic-related) air pollution was associated with higher systolic and diastolic blood pressure. These findings, if they persist, might have clinical relevance at older age.

  17. Parameters of an avalanche of runaway electrons in air under atmospheric pressure

    Science.gov (United States)

    Oreshkin, E. V.

    2018-01-01

    The features of runaway-electron avalanches developing in air under atmospheric pressures are investigated in the framework of a three-dimensional numerical simulation. The simulation results indicate that an avalanche of this type can be characterized, besides the time and length of its exponential growth, by the propagation velocity and by the average kinetic energy of the runaway electrons. It is shown that these parameters obey the similarity laws applied to gas discharges.

  18. Influences of ammonia contamination on leaching from air-pollution-control residues

    DEFF Research Database (Denmark)

    Guan, Zhenzhen; Chen, Dezhen; Astrup, Thomas Fruergaard

    2014-01-01

    Application of selective non-catalytic reduction systems at municipal solid waste incinerators (MSWIs) often involves over-stoichiometric injection of ammonia into flue gases. Un-reacted ammonia may be deposited on fly ash particles and can ultimately influence the leaching behaviour of air...

  19. 78 FR 66107 - National Emissions Standards for Hazardous Air Pollutants Residual Risk and Technology Review for...

    Science.gov (United States)

    2013-11-04

    ...) part 2. Send or deliver information identified as CBI only to the following address: Roberto Morales... facility-specific maximum risk values based on MACT-allowable emissions. The docket for this rulemaking... and health benchmarks are the latest values recommended by the EPA for HAP and other toxic air...

  20. Element composition and mineralogical characterisation of air pollution control residue from UK energy-from-waste facilities

    Energy Technology Data Exchange (ETDEWEB)

    Bogush, Anna [Centre for Resource Efficiency & the Environment (CREE), Department of Civil, Environmental & Geomatic Engineering (CEGE), University College London UCL, Chadwick Building, Gower Street, London WC1E 6BT (United Kingdom); Stegemann, Julia A., E-mail: j.stegemann@ucl.ac.uk [Centre for Resource Efficiency & the Environment (CREE), Department of Civil, Environmental & Geomatic Engineering (CEGE), University College London UCL, Chadwick Building, Gower Street, London WC1E 6BT (United Kingdom); Wood, Ian [Department of Earth Sciences, University College London UCL, Gower Street, London WC1E 6BT (United Kingdom); Roy, Amitava [J. Bennett Johnston, Sr., Center for Advanced Microstructures & Devices, Louisiana State University, 6980 Jefferson Hwy, Baton Rouge, LA 70806 (United States)

    2015-02-15

    Highlights: • 66 elements, including “critical strategic elements” were determined in UK EfW APC residues. • Metal pollutants (Zn, Pb, As, Cd, Cu, Mo, Sb, Sn, Se, Ag and In) are enriched in APC residues. • Metal pollutants were widely associated with fine deposits of highly soluble CaCl{sub x}OH{sub 2−x}. • Specific metal (Zn, Pb, Cu)-bearing minerals were also detected in APC residues. - Abstract: Air pollution control (APC) residues from energy-from-waste (EfW) are alkaline (corrosive) and contain high concentrations of metals, such as zinc and lead, and soluble salts, such as chlorides and sulphates. The EPA 3050B-extractable concentrations of 66 elements, including critical elements of strategic importance for advanced electronics and energy technologies, were determined in eight APC residues from six UK EfW facilities. The concentrations of Ag (6–15 mg/kg) and In (1–13 mg/kg), as well as potential pollutants, especially Zn (0.26–0.73 wt.%), Pb (0.05–0.2 wt.%), As, Cd, Cu, Mo, Sb, Sn and Se were found to be enriched in all APC residues compared to average crustal abundances. Results from a combination of scanning electron microscopy with energy dispersive X-ray spectroscopy and also powder X-ray diffraction, thermal analysis and Fourier transform infrared spectroscopy give an exceptionally full understanding of the mineralogy of these residues, which is discussed in the context of other results in the literature. The present work has shown that the bulk of the crystalline phases present in the investigated APC residues include Ca-based phases, such as CaCl{sub x}OH{sub 2−x}, CaCO{sub 3}, Ca(OH){sub 2}, CaSO{sub 4}, and CaO, as well as soluble salts, such as NaCl and KCl. Poorly-crystalline aragonite was identified by FTIR. Sulphur appears to have complex redox speciation, presenting as both anhydrite and hannebachite in some UK EfW APC residues. Hazardous elements (Zn and Pb) were widely associated with soluble Ca- and Cl-bearing phases

  1. Micro-controller based air pressure monitoring instrumentation system using optical fibers as sensor

    Science.gov (United States)

    Hazarika, D.; Pegu, D. S.

    2013-03-01

    This paper describes a micro-controller based instrumentation system to monitor air pressure using optical fiber sensors. The principle of macrobending is used to develop the sensor system. The instrumentation system consists of a laser source, a beam splitter, two multi mode optical fibers, two Light Dependent Resistance (LDR) based timer circuits and a AT89S8252 micro-controller. The beam splitter is used to divide the laser beam into two parts and then these two beams are launched into two multi mode fibers. One of the multi mode fibers is used as the sensor fiber and the other one is used as the reference fiber. The use of the reference fiber is to eliminate the environmental effects while measuring the air pressure magnitude. The laser beams from the sensor and reference fibers are applied to two identical LDR based timer circuits. The LDR based timer circuits are interfaced to a micro-controller through its counter pins. The micro-controller samples the frequencies of the timer circuits using its counter-0 and counter-1 and the counter values are then processed to provide the measure of air pressure magnitude.

  2. Sterilization effect of atmospheric pressure non-thermal air plasma on dental instruments.

    Science.gov (United States)

    Sung, Su-Jin; Huh, Jung-Bo; Yun, Mi-Jung; Chang, Brian Myung W; Jeong, Chang-Mo; Jeon, Young-Chan

    2013-02-01

    Autoclaves and UV sterilizers have been commonly used to prevent cross-infections between dental patients and dental instruments or materials contaminated by saliva and blood. To develop a dental sterilizer which can sterilize most materials, such as metals, rubbers, and plastics, the sterilization effect of an atmospheric pressure non-thermal air plasma device was evaluated. After inoculating E. coli and B. subtilis the diamond burs and polyvinyl siloxane materials were sterilized by exposing them to the plasma for different lengths of time (30, 60, 90, 120, 180 and, 240 seconds). The diamond burs and polyvinyl siloxane materials were immersed in PBS solutions, cultured on agar plates and quantified by counting the colony forming units. The data were analyzed using one-way ANOVA and significance was assessed by the LSD post hoc test (α=0.05). The device was effective in killing E. coli contained in the plasma device compared with the UV sterilizer. The atmospheric pressure non-thermal air plasma device contributed greatly to the sterilization of diamond burs and polyvinyl siloxane materials inoculated with E. coli and B. subtilis. Diamond burs and polyvinyl siloxane materials inoculated with E. coli was effective after 60 and 90 seconds. The diamond burs and polyvinyl siloxane materials inoculated with B. subtilis was effective after 120 and 180 seconds. The atmospheric pressure non-thermal air plasma device was effective in killing both E. coli and B. subtilis, and was more effective in killing E. coli than the UV sterilizer.

  3. Radial Distribution of the Nanosecond Dielectric Barrier Discharge Current in Atmospheric-Pressure Air

    Science.gov (United States)

    Malashin, M. V.; Moshkunov, S. I.; Khomich, V. Yu.; Shershunova, E. A.

    2018-01-01

    Experimental results on the radial distribution of the nanosecond dielectric barrier discharge (DBD) current in flat millimeter air gaps under atmospheric pressure and natural humidity of 40-60% at a voltage rise rate at the electrodes of 250 V/ns are presented. The time delay of the appearance of discharge currents was observed to increase from the center to the periphery of the air gap at discharge gap heights above 3 mm, which correlated with the appearance of constricted channels against the background of the volume DBD plasma. Based on the criterion of the avalanche-streamer transition, it is found out that the development of a nanosecond DBD in air gaps of 1-3 mm occurs by the streamer mechanism.

  4. Rebubbling in Descemet Membrane Endothelial Keratoplasty: Influence of Pressure and Duration of the Intracameral Air Tamponade.

    Science.gov (United States)

    Pilger, Daniel; Wilkemeyer, Ina; Schroeter, Jan; Maier, Anna-Karina B; Torun, Necip

    2017-06-01

    To explore the impact of intracameral air tamponade pressure and duration on graft attachment and rebubbling rates. A prospective, interventional, nonrandomized study. setting: Department of Ophthalmology, Charité - Universitätsmedizin Berlin. One hundred seventeen patients who underwent Descemet membrane endothelial keratoplasty (DMEK). Intraocular pressure (IOP) at the end of the surgery, immediately after filling the anterior chamber with air, categorized into low (20 mm Hg), and the time until partial removal of the air. Rebubbling rates and endothelial cell density over a 3-month follow-up period analyzed by a multivariable Cox regression model and an analysis of covariance model. Thirty-two patients required a rebubbling (27% [95% CI 19%-35%]). Nine patients required more than 1 rebubbling (7% [95% CI 3%-12%]). Compared with normal IOP, lower (HR 8.98 [95% CI 1.07-75.41]) and higher IOP (HR 10.63 [95% CI 1.44-78.27]) increased the risk of requiring a rebubbling (P = .006). Independent of the IOP, an air tamponade duration beyond 2 hours reduced the risk of rebubbling (HR 0.36 [95% CI 0.18-0.71, P = .003]). One month after surgery, the mean endothelial cell loss was 13% (95% CI 2%-25%) and 23% (95% CI 17%-29%) in the group with air tamponade duration of below and above 2 hours, respectively (P = .126). At 3 months after surgery, it was 31% (95% CI 17%-42%) and 42% (95% CI 32%-52%) in the respective groups (P = .229). A postsurgical air tamponade of at least 2 hours with an IOP within the physiological range could help to reduce rebubbling rates. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Advancing a smart air cushion system for preventing pressure ulcers using projection Moiré for large deformation measurements

    Science.gov (United States)

    Cheng, Sheng-Lin; Tsai, Tsung-Heng; Lee, Carina Jean-Tien; Hsu, Yu-Hsiang; Lee, Chih-Kung

    2016-03-01

    A pressure ulcer is one of the most important concerns for wheelchair bound patients with spinal cord injuries. A pressure ulcer is a localized injury near the buttocks that bear ischial tuberosity oppression over a long period of time. Due to elevated compression to blood vessels, the surrounding tissues suffer from a lack of oxygen and nutrition. The ulcers eventually lead to skin damage followed by tissue necrosis. The current medical strategy is to minimize the occurrence of pressure ulcers by regularly helping patients change their posture. However, these methods do not always work effectively or well. As a solution to fundamentally prevent pressure ulcers, a smart air cushion system was developed to detect and control pressure actively. The air cushion works by automatically adjusting a patient's sitting posture to effectively relieve the buttock pressure. To analyze the correlation between the dynamic pressure profiles of an air cell with a patient's weight, a projection Moiré system was adopted to measure the deformation of an air cell and its associated stress distribution. Combining a full-field deformation imaging with air pressure measured within an air cell, the patient's weight and the stress distribution can be simultaneously obtained. By integrating a full-field optical metrology with a time varying pressure sensor output coupled with different active air control algorithms for various designs, we can tailor the ratio of the air cells. Our preliminary data suggests that this newly developed smart air cushion has the potential to selectively reduce localized compression on the tissues at the buttocks. Furthermore, it can take a patient's weight which is an additional benefit so that medical personnel can reference it to prescribe the correct drug dosages.

  6. 2.45 GHz microwave-excited atmospheric pressure air microplasmas based on microstrip technology

    International Nuclear Information System (INIS)

    Kim, Jaeho; Terashima, Kazuo

    2005-01-01

    A plasma system based on microstrip technology was developed for the generation of atmospheric pressure microplasmas. A discharge gap was placed between the striplines and the ground plane on the transverse cross section in the direction of microwave propagation. This microstrip structure permits the concentration of electric fields at the discharge gap, which is confirmed by a computer simulation using the three-dimensional simulation code based on the finite-difference time-domain method, and can produce atmospheric pressure plasmas even in air. The microplasmas were sustained in the discharge gap (width: 0.2 mm, length: 6 mm) at a microwave power of 1 W. The experimentally measured rotational temperature of nitrogen molecules was 800 K, indicating these plasmas to be nonthermal plasmas. This plasma system will provide a portable microplasma system utilizing a small semiconductor microwave source and a large-scale atmospheric pressure nonthermal plasma using the array configuration

  7. Pressurized Intravenous Fluid Administration in the Professional Football Player: A Unique Setting for Venous Air Embolism.

    Science.gov (United States)

    Fibel, Kenton H; Barnes, Ronnie P; Kinderknecht, James J

    2015-07-01

    Venous air embolism (VAE) is a potentially life-threatening event that is most commonly associated with certain surgical procedures, although this theoretical complication of pressurized rapid infusion of intravenous (IV) fluids has been described. This series of cases describes 4 athletes who presented with continuous coughing and other chest complaints after peripheral IV infusion of normal saline through manual pressurized infusion. Symptoms resolved within 20 minutes, and these incidences did not interfere with resuming athletic competition with no recurrence of symptoms or complications. These cases are most consistent with varying degrees of VAE and reveal the risk of VAE associated with pressurized peripheral IV fluid administration along with the unique clinical presentation of more modest forms of VAE in an awake patient. Becoming more knowledgeable about IV infusion technique and understanding potential pitfalls can be helpful in reducing future incidences of VAE.

  8. Operational design and pressure response of large-scale compressed air energy storage in porous formations

    Science.gov (United States)

    Wang, Bo; Bauer, Sebastian

    2017-04-01

    With the rapid growth of energy production from intermittent renewable sources like wind and solar power plants, large-scale energy storage options are required to compensate for fluctuating power generation on different time scales. Compressed air energy storage (CAES) in porous formations is seen as a promising option for balancing short-term diurnal fluctuations. CAES is a power-to-power energy storage, which converts electricity to mechanical energy, i.e. highly pressurized air, and stores it in the subsurface. This study aims at designing the storage setup and quantifying the pressure response of a large-scale CAES operation in a porous sandstone formation, thus assessing the feasibility of this storage option. For this, numerical modelling of a synthetic site and a synthetic operational cycle is applied. A hypothetic CAES scenario using a typical anticline structure in northern Germany was investigated. The top of the storage formation is at 700 m depth and the thickness is 20 m. The porosity and permeability were assumed to have a homogenous distribution with a value of 0.35 and 500 mD, respectively. According to the specifications of the Huntorf CAES power plant, a gas turbine producing 321 MW power with a minimum inlet pressure of 43 bars at an air mass flowrate of 417 kg/s was assumed. Pressure loss in the gas wells was accounted for using an analytical solution, which defines a minimum bottom hole pressure of 47 bars. Two daily extraction cycles of 6 hours each were set to the early morning and the late afternoon in order to bypass the massive solar energy production around noon. A two-year initial filling of the reservoir with air and ten years of daily cyclic operation were numerically simulated using the Eclipse E300 reservoir simulator. The simulation results show that using 12 wells the storage formation with a permeability of 500 mD can support the required 6-hour continuous power output of 321MW, which corresponds an energy output of 3852 MWh per

  9. Traffic-related air pollution and noise and children's blood pressure: results from the PIAMA birth cohort study.

    Science.gov (United States)

    Bilenko, Natalya; van Rossem, Lenie; Brunekreef, Bert; Beelen, Rob; Eeftens, Marloes; Hoek, Gerard; Houthuijs, Danny; de Jongste, Johan C; van Kempen, Elise; Koppelman, Gerard H; Meliefste, Kees; Oldenwening, Marieke; Smit, Henriette A; Wijga, Alet H; Gehring, Ulrike

    2015-01-01

    Elevation of a child's blood pressure may cause possible health risks in later life. There is evidence for adverse effects of exposure to air pollution and noise on blood pressure in adults. Little is known about these associations in children. We investigated the associations of air pollution and noise exposure with blood pressure in 12-year-olds. Blood pressure was measured at age 12 years in 1432 participants of the PIAMA birth cohort study. Annual average exposure to traffic-related air pollution [NO2, mass concentrations of particulate matter with diameters of less than 2.5 µm (PM2.5) and less than 10 µm (PM10), and PM2.5 absorbance] at the participants' home and school addresses at the time of blood pressure measurements was estimated by land-use regression models. Air pollution exposure on the days preceding blood pressure measurements was estimated from routine air monitoring data. Long-term noise exposure was assessed by linking addresses to modelled equivalent road traffic noise levels. Associations of exposures with blood pressure were analysed by linear regression. Effects are presented for an interquartile range increase in exposure. Long-term exposure to NO2 and PM2.5 absorbance were associated with increased diastolic blood pressure, in children who lived at the same address since birth [adjusted mean difference (95% confidence interval) [mmHg] 0.83 (0.06 to 1.61) and 0.75 (-0.08 to 1.58), respectively], but not with systolic blood pressure. We found no association of blood pressure with short-term air pollution or noise exposure. Long-term exposure to traffic-related air pollution may increase diastolic blood pressure in children. © The European Society of Cardiology 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  10. Analysis of an Aircraft Honeycomb Sandwich Panel with Circular Face Sheet/Core Disbond Subjected to Ground-Air Pressurization

    Science.gov (United States)

    Rinker, Martin; Krueger, Ronald; Ratcliffe, James

    2013-01-01

    The ground-air pressurization of lightweight honeycomb sandwich structures caused by alternating pressure differences between the enclosed air within the honeycomb core and the ambient environment is a well-known and controllable loading condition of aerospace structures. However, initial face sheet/core disbonds intensify the face sheet peeling effect of the internal pressure load significantly and can decrease the reliability of the sandwich structure drastically. Within this paper, a numerical parameter study was carried out to investigate the criticality of initial disbonds in honeycomb sandwich structures under ground-air pressurization. A fracture mechanics approach was used to evaluate the loading at the disbond front. In this case, the strain energy release rate was computed via the Virtual Crack Closure Technique. Special attention was paid to the pressure-deformation coupling which can decrease the pressure load within the disbonded sandwich section significantly when the structure is highly deformed.

  11. Decay of femtosecond laser-induced plasma filaments in air, nitrogen, and argon for atmospheric and subatmospheric pressures.

    Science.gov (United States)

    Aleksandrov, N L; Bodrov, S B; Tsarev, M V; Murzanev, A A; Sergeev, Yu A; Malkov, Yu A; Stepanov, A N

    2016-07-01

    The temporal evolution of a plasma channel at the trail of a self-guided femtosecond laser pulse was studied experimentally and theoretically in air, nitrogen (with an admixture of ∼3% O_{2}), and argon in a wide range of gas pressures (from 2 to 760 Torr). Measurements by means of transverse optical interferometry and pulsed terahertz scattering techniques showed that plasma density in air and nitrogen at atmospheric pressure reduces by an order of magnitude within 3-4 ns and that the decay rate decreases with decreasing pressure. The argon plasma did not decay within several nanoseconds for pressures of 50-760 Torr. We extended our theoretical model previously applied for atmospheric pressure air plasma to explain the plasma decay in the gases under study and to show that allowance for plasma channel expansion affects plasma decay at low pressures.

  12. Improved rice residue burning emissions estimates: Accounting for practice-specific emission factors in air pollution assessments of Vietnam.

    Science.gov (United States)

    Lasko, Kristofer; Vadrevu, Krishna

    2018-05-01

    In Southeast Asia and Vietnam, rice residues are routinely burned after the harvest to prepare fields for the next season. Specific to Vietnam, the two prevalent burning practices include: a). piling the residues after hand harvesting; b). burning the residues without piling, after machine harvesting. In this study, we synthesized field and laboratory studies from the literature on rice residue burning emission factors for PM 2.5 . We found significant differences in the resulting burning-practice specific emission factors, with 16.9 g kg -2 (±6.9) for pile burning and 8.8 g kg -2 (±3.5) for non-pile burning. We calculated burning-practice specific emissions based on rice area data, region-specific fuel-loading factors, combined emission factors, and estimates of burning from the literature. Our results for year 2015 estimate 180 Gg of PM 2.5 result from the pile burning method and 130 Gg result from non-pile burning method, with the most-likely current emission scenario of 150 Gg PM 2.5 emissions for Vietnam. For comparison purposes, we calculated emissions using generalized agricultural emission factors employed in global biomass burning studies. These results estimate 80 Gg PM 2.5 , which is only 44% of the pile burning-based estimates, suggesting underestimation in previous studies. We compare our emissions to an existing all-combustion sources inventory, results show emissions account for 14-18% of Vietnam's total PM 2.5 depending on burning practice. Within the highly-urbanized and cloud-covered Hanoi Capital region (HCR), we use rice area from Sentinel-1A to derive spatially-explicit emissions and indirectly estimate residue burning dates. Results from HYSPLIT back-trajectory analysis stratified by season show autumn has most emission trajectories originating in the North, while spring has most originating in the South, suggesting the latter may have bigger impact on air quality. From these results, we highlight locations where emission

  13. Static Air Support Surfaces to Prevent Pressure Injuries: A Multicenter Cohort Study in Belgian Nursing Homes.

    Science.gov (United States)

    Serraes, Brecht; Beeckman, Dimitri

    2016-01-01

    The aim of this study was to investigate the incidence and risk factors for developing pressure injuries (PIs) in patients placed on a static air support surfaces: mattress overlay, heel wedge, and seat cushion. Multicenter cohort study. The sample comprised 176 residents; their mean age was 87 (SD = 6.76) years; their mean Braden Scale score was 14 (SD = 2.54). The study was performed on a convenience sample of 6 nursing homes in Belgium. Data were collected on 23 care units. The primary outcome measure, cumulative PI incidence (category [stage] II-IV) over a 30-day observation period, was calculated. Pressure injury occurrence was defined according to the 2014 European and US National Pressure Injury Advisory panels, Pan Pacific Pressure Injury Alliance classification system. The PI incidence for category (stage) II-IV was 5.1%. Six residents (3.4%) developed a category II PI, and 3 (1.7%) developed a category III PI; no category IV ulcers occurred. No significant risk factors for category II-IV PIs were identified using multivariate logistic regression. Time of sitting in a chair was found to be a risk factor for development of nonblanchable erythema (category I PI) (odds ratio = 21.608; 95% confidence interval [CI], 20.510-22.812; P = .013). The median time to develop a category II-IV PI was 16 days (interquartile range = 2-26). The interrater reliability between the observations of the researcher and nurses on-site was almost perfect (0.86; 95% CI, 0.81-0.91). We found a low incidence of PIs when using a static air overlay mattress for patients at risk in a nursing home population. Static air support surfaces, alongside patient-tailored patient repositioning protocols, should be considered to prevent PIs in this patient population.

  14. Performance of a biogas upgrading process based on alkali absorption with regeneration using air pollution control residues.

    Science.gov (United States)

    Baciocchi, Renato; Carnevale, Ennio; Costa, Giulia; Gavasci, Renato; Lombardi, Lidia; Olivieri, Tommaso; Zanchi, Laura; Zingaretti, Daniela

    2013-12-01

    This work analyzes the performance of an innovative biogas upgrading method, Alkali absorption with Regeneration (AwR) that employs industrial residues and allows to permanently store the separated CO2. This process consists in a first stage in which CO2 is removed from the biogas by means of chemical absorption with KOH or NaOH solutions followed by a second stage in which the spent absorption solution is contacted with waste incineration Air Pollution Control (APC) residues. The latter reaction leads to the regeneration of the alkali reagent in the solution and to the precipitation of calcium carbonate and hence allows to reuse the regenerated solution in the absorption process and to permanently store the separated CO2 in solid form. In addition, the final solid product is characterized by an improved environmental behavior compared to the untreated residues. In this paper the results obtained by AwR tests carried out in purposely designed demonstrative units installed in a landfill site are presented and discussed with the aim of verifying the feasibility of this process at pilot-scale and of identifying the conditions that allow to achieve all of the goals targeted by the proposed treatment. Specifically, the CO2 removal efficiency achieved in the absorption stage, the yield of alkali regeneration and CO2 uptake resulting for the regeneration stage, as well as the leaching behavior of the solid product are analyzed as a function of the type and concentration of the alkali reagent employed for the absorption reaction. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Impact of changes of positive end-expiratory pressure on functional residual capacity at low tidal volume ventilation during general anesthesia

    OpenAIRE

    Satoh, Daizoh; Kurosawa, Shin; Kirino, Wakaba; Wagatsuma, Toshihiro; Ejima, Yutaka; Yoshida, Akiko; Toyama, Hiroaki; Nagaya, Kei

    2012-01-01

    Purpose Several reports in the literature have described the effects of positive end-expiratory pressure (PEEP) level upon functional residual capacity (FRC) in ventilated patients during general anesthesia. This study compares FRC in mechanically low tidal volume ventilation with different PEEP levels during upper abdominal surgery. Methods Before induction of anesthesia (awake) for nine patients with upper abdominal surgery, a tight-seal facemask was applied with 2 cmH2O pressure support ve...

  16. Design of a MEMS piezoresistive differential pressure sensor with small thermal hysteresis for air data modules.

    Science.gov (United States)

    Song, Jin Woo; Lee, Jang-Sub; An, Jun-Eon; Park, Chan Gook

    2015-06-01

    The design, fabrication, and evaluation results of a MEMS piezoresistive differential pressure sensor fabricated by the dry etching process are described in this paper. The proposed sensor is designed to have optimal performances in mid-pressure range from 0 psi to 20 psi suitable for a precision air data module. The piezoresistors with a Wheatstone bridge structure are implanted where the thermal effects are minimized subject to sustainment of the sensitivity. The rectangular-shaped silicon diaphragm is adopted and its dimension is analyzed for improving pressure sensitivity and linearity. The bridge resistors are driven by constant current to compensate temperature effects on sensitivity. The designed differential pressure sensor is fabricated by using MEMS dry etching techniques, and the fabricated sensing element is attached and packaged in a Kovar package in consideration of leakage and temperature hysteresis. The implemented sensors are tested and evaluated as well. The evaluation results show the static RSS (root sum square) accuracy including nonlinearity, non-repeatability, and pressure hysteresis before temperature compensation is about 0.09%, and the total error band which includes the RSS accuracy, the thermal hysteresis, and other thermal effects is about 0.11%, which confirm the validity of the proposed design process.

  17. Design of air blast pressure sensors based on miniature silicon membrane and piezoresistive gauges

    Science.gov (United States)

    Riondet, J.; Coustou, A.; Aubert, H.; Pons, P.; Lavayssière, M.; Luc, J.; Lefrançois, A.

    2017-11-01

    Available commercial piezoelectric pressure sensors are not able to accurately reproduce the ultra-fast transient pressure occurring during an air blast experiment. In this communication a new pressure sensor prototype based on a miniature silicon membrane and piezoresistive gauges is reported for significantly improving the performances in terms of time response. Simulation results demonstrate the feasibility of a pressure transducer having a fundamental resonant frequency almost ten times greater than the commercial piezoelectric sensors one. The sensor uses a 5μm-thick SOI membrane and four P-type silicon gauges (doping level ≅ 1019 at/cm3) in Wheatstone bridge configuration. To obtain a good trade-off between the fundamental mechanical resonant frequency and pressure sensitivity values, the typical dimension of the rectangular membrane is fixed to 30μm x 90μm with gauge dimension of 1μm x 5μm. The achieved simulated mechanical resonant frequency of these configuration is greater than 40MHz with a sensitivity of 0.04% per bar.

  18. Surface modification of polytetrafluoroethylene film using the atmospheric pressure glow discharge in air

    International Nuclear Information System (INIS)

    Fang, Z; Qiu, Y; Luo, Y

    2003-01-01

    The atmospheric pressure glow discharge (APGD) is more promising in industrial applications compared with glow discharges in a gas other than air or in low-pressure air, which needs an expensive vacuum system. In this paper, the APGD and dielectric barrier discharge (DBD) are generated in atmospheric air using a power-frequency voltage source, and the transition from DBD to APGD is achieved by varying the electrode arrangement. The differences between their discharge characteristics are shown by measurement of their electrical discharge parameters and observation of light-emission phenomena. The effects of APGD and DBD on polytetrafluoroethylene (PTFE) surface modification are studied. The surface properties are characterized by contact angle measurement, x-ray photoelectron spectroscopy and scanning electron microscopy. It is found that the APGD and DBD treatments modify the PTFE surface in both morphology and composition. APGD is more effective in PTFE surface modification than DBD as it can modify the surface more uniformly, implant more oxygen atoms into the surface and make the contact angle decline to a lower level. The experimental results are discussed

  19. PA171 Containers on a Wood Pallet with Metal Top Adapter, Air Pressure Tests During MIL-STD-1660 Tests

    National Research Council Canada - National Science Library

    2004-01-01

    ... (PM-MAS) to conduct Air Pressure Tests during MIL-STD-1660, "Design Criteria for Ammunition Unit Loads" testing on the PA171 containers on a wood pallet with metal top adapter as manufactured by Alliant Tech...

  20. Effects of hyperbaric treatment in cerebral air embolism on intracranial pressure, brain oxygenation, and brain glucose metabolism in the pig

    NARCIS (Netherlands)

    van Hulst, Robert A.; Drenthen, Judith; Haitsma, Jack J.; Lameris, Thomas W.; Visser, Gerhard H.; Klein, Jan; Lachmann, Burkhard

    2005-01-01

    OBJECTIVE: To evaluate the effects of hyperbaric oxygen treatment after cerebral air embolism on intracranial pressure, brain oxygenation, brain glucose/lactate metabolism, and electroencephalograph. DESIGN: Prospective animal study. SETTING: Hyperbaric chamber. SUBJECTS: Eleven Landrace/Yorkshire

  1. The impact of mass flow and masking on the pressure drop of air filter in heavy-duty diesel engine

    Directory of Open Access Journals (Sweden)

    Gorji-Bandpy Mofid

    2012-04-01

    Full Text Available This paper presents a computational fluid dynamics (CFD calculation approach to predict and evaluate the impact of the mass-flow inlet on the pressure drop of turbocharger`s air filtfer in heavy-duty diesel engine. The numerical computations were carried out using a commercial CFD program whereas the inlet area of the air filter consisted of several holes connected to a channel. After entering through the channel, the air passes among the holes and enters the air filter. The effect of masking holes and hydraulic diameter is studied and investigated on pressure drop. The results indicate that pressure drop increase with decreasing of hydraulic diameter and masking of the holes has considerable affect on the pressure drop.

  2. Filterability of freshly-collected sickle erythrocytes under venous oxygen pressure without exposure to air.

    Science.gov (United States)

    Shah, Siddharth; Acholonu, Rhonda Graves; Ohene-Frempong, Kwaku; Asakura, Toshio

    2015-12-01

    We previously found that blood samples collected from steady-state patients with sickle cell disease (SCD) without exposure to air contain a new type of reversibly sickled cells (RSCs) with blunt edges at a level of as high as 78%. Since partial oxygenation of once-deoxygenated sickled cells with pointy edges to near venous oxygen pressure generates similar sickled cells with blunt edges in vitro, we named them as partially oxygenated sickled cells (POSCs). On the other hand, partial deoxygenation of once-oxygenated SS cells to venous oxygen pressure generates partially deoxygenated sickled cells (PDSCs) with pointy edges. In this study, we obtained blood samples from 6 steady-state patients with SCD under venous oxygen pressure without exposure to air, subjected them to various oxygenation/deoxygenation/reoxygenation cycles, and studied their filterability through a membrane filter with pore diameter of 3μm, the theoretical minimum diameter of a capillary. Our results indicated that discocytes, POSCs with blunt edges, and irreversibly sickled cells could deform and pass through the filter, while PDSCs with pointy edges were rigid and could not. The filterability of SS cells seems to be related to the length and amount of deoxy-hemoglobin S fibers in the cells. Copyright © 2015. Published by Elsevier Inc.

  3. On spatial stabilization of dielectric barrier discharge microfilaments by residual heat build-up in air

    Science.gov (United States)

    Ráhel, Jozef; Szalay, Zsolt; Čech, Jan; Morávek, Tomás

    2016-04-01

    Microfilaments of dielectric barrier discharge are known for their multiple re-appearance at the same spot on dielectrics. This effect of localized re-appearance is driven by residual excited species and ions, surface charge deposited on the dielectric and the local temperature build-up resulting in the local increase of reduced electric field E/ΔN. To assess the magnitude of the latter, the breakdown voltage vs. temperature up to 180 °C was carefully measured at coplanar DBD and used as an input into the numerical simulation of heat build-up by the train of discharge pulses. An average reduction of breakdown voltage was found to be 20 V/K. The model predicted a quasi-stable microfilament temperature into which the thermal build-up rapidly converges. Its magnitude agreed well with the reported rotational temperature of similar electrode configuration. The impact of quasi-stable temperature on microfilament formation dynamics is further discussed. Contribution to the Topical Issue "Recent Breakthroughs in Microplasma Science and Technology", edited by Kurt Becker, Jose Lopez, David Staack, Klaus-Dieter Weltmann and Wei Dong Zhu.

  4. Pressure Relief, Visco-Elastic Foam with Inflated Air? A Pilot Study in a Dutch Nursing Home

    OpenAIRE

    Van Leen, Martin; Schols, Jos

    2015-01-01

    Objective: There is still little evidence regarding the type of mattress that is the best for preventing pressure ulcers (PUs). In a Dutch nursing home, a new type of overlay mattress (air inflated visco-elastic foam) was tested to analyze the opportunity for replacement of the normally used static air overlay mattress in its three-step PU prevention protocol In this small pilot the outcome measures were: healing of a category one pressure ulcer, new development or deterioration of a category...

  5. Global association between ambient air pollution and blood pressure: A systematic review and meta-analysis.

    Science.gov (United States)

    Yang, Bo-Yi; Qian, Zhengmin; Howard, Steven W; Vaughn, Michael G; Fan, Shu-Jun; Liu, Kang-Kang; Dong, Guang-Hui

    2018-04-01

    Although numerous studies have investigated the association of ambient air pollution with hypertension and blood pressure (BP), the results were inconsistent. We performed a comprehensive systematic review and meta-analysis of these studies. Seven international and Chinese databases were searched for studies examining the associations of particulate (diameter10 μm (PM 10 )) and gaseous (sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), nitrogen oxides (NO x ), ozone (O 3 ), carbon monoxide (CO)) air pollutants with hypertension or BP. Odds ratios (OR), regression coefficients (β) and their 95% confidence intervals were calculated to evaluate the strength of the associations. Subgroup analysis, sensitivity analysis, and meta-regression analysis were also conducted. The overall meta-analysis showed significant associations of long-term exposures to PM 2.5 with hypertension (OR = 1.05), and of PM 10 , PM 2.5 , and NO 2 with DBP (β values: 0.47-0.86 mmHg). In addition, short-term exposures to four (PM 10 , PM 2.5 , SO 2 , NO 2 ), two (PM 2.5 and SO 2 ), and four air pollutants (PM 10 , PM 2.5 , SO 2 , and NO 2 ), were significantly associated with hypertension (ORs: 1.05-1.10), SBP (β values: 0.53-0.75 mmHg) and DBP (β values: 0.15-0.64 mmHg), respectively. Stratified analyses showed a generally stronger relationship among studies of men, Asians, North Americans, and areas with higher air pollutant levels. In conclusion, our study indicates a positive association between ambient air pollution and increased BP and hypertension. Geographical and socio-demographic factors may modify the pro-hypertensive effects of air pollutants. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Heat exchange effectiveness and pressure drop for air flow through perforated plates with and without crosswind

    Science.gov (United States)

    Kutscher, C. F.

    1994-05-01

    Low-porosity perforated plates are being used as absorbers for heating ambient air in a new type of unglazed solar collector. This paper investigates the convective heat transfer effectiveness for low-speed air flow through thin, isothermal perforated plates with and without a crosswind on the upstream face. The objective of this work is to provide information that will allow designers to optimize hole size and spacing. In order to obtain performance data, a wind tunnel and small lamp array were designed and built. Experimental data were taken for a range of plate porosities from 0.1 to 5 percent, hole Reynolds numbers from 100 to 2000, and wind speeds from 0 to 4 m/s. Correlations were developed for heat exchange effectiveness and also for pressure drop. Infrared thermography was used to visualize the heat transfer taking place at the surface.

  7. Long-term performance of air-side heat transfer and pressure drop for finned tube evaporators of air conditioners under intermittent operation conditions

    Energy Technology Data Exchange (ETDEWEB)

    Pu, Hui; Ding, Guo-liang; Ma, Xiao-kui; Hu, Hai-tao [Institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, Shanghai 200240 (China); Gao, Yi-feng [International Copper Association Shanghai Office, 381 Huaihaizhong Road, Shanghai 200020 (China)

    2010-01-15

    In this study, the effects of long-term intermittent operations on the air-side heat transfer and pressure drop performance of finned tube evaporators of air conditioners were investigated by experiments on an aluminum-fin evaporator and a copper-fin evaporator. In order to simulate intermittent operations of on-off controlled air conditioners, the temperatures of the two evaporators changed to 5 {+-} 0.5 C at first and then to 27 {+-} 0.5 C repeatedly. The repetition number was up to 4800, and the air-side heat transfer and pressure drop of the two evaporators were tested after every 300 repetitions. The test results indicate that after long-term intermittent operations, the air-side heat transfer coefficient decreases and the pressure drop increases. The variations of the heat transfer coefficient and the pressure drop are more obvious at lower inlet air velocity, and the influence of long-term intermittent operations on the aluminum-fin evaporator is greater than that on the copper-fin evaporator. (author)

  8. Energy distribution of runaway electrons generated by a nanosecond discharge in atmospheric-pressure air

    Science.gov (United States)

    Tarasenko, V. F.; Baksht, E. Kh.; Burachenko, A. G.; Kostyrya, I. D.; Lomaev, M. I.; Petin, V. K.; Rybka, D. V.; Shlyakhtun, S. V.

    2008-12-01

    The spectra of an ultrashort avalanche electron beam generated by a nanosecond discharge in atmospheric-pressure air were investigated. The temporal characteristics of the beam current pulses, gap voltage, and discharge current in a gas diode were measured with a time resolution of ˜0.1 ns. A simple technique was developed for recovering electron spectra from the curves of beam attenuation by aluminum foils. The effect of the cathode design, electrode gap length, and generator parameters on the electron spectra were studied using seven setups. It is shown that generation of electrons with anomalously high energies requires the use of cathodes with increased curvature radius.

  9. Integrated LTCC pressure/flow/temperature multisensor for compressed air diagnostics.

    Science.gov (United States)

    Fournier, Yannick; Maeder, Thomas; Boutinard-Rouelle, Grégoire; Barras, Aurélie; Craquelin, Nicolas; Ryser, Peter

    2010-01-01

    We present a multisensor designed for industrial compressed air diagnostics and combining the measurement of pressure, flow, and temperature, integrated with the corresponding signal conditioning electronics in a single low-temperature co-fired ceramic (LTCC) package. The developed sensor may be soldered onto an integrated electro-fluidic platform by using standard surface mount device (SMD) technology, e.g., as a standard electronic component would be on a printed circuit board, obviating the need for both wires and tubes and thus paving the road towards low-cost integrated electro-fluidic systems. Several performance aspects of this device are presented and discussed, together with electronics design issues.

  10. Integrated LTCC Pressure/Flow/Temperature Multisensor for Compressed Air Diagnostics†

    Science.gov (United States)

    Fournier, Yannick; Maeder, Thomas; Boutinard-Rouelle, Grégoire; Barras, Aurélie; Craquelin, Nicolas; Ryser, Peter

    2010-01-01

    We present a multisensor designed for industrial compressed air diagnostics and combining the measurement of pressure, flow, and temperature, integrated with the corresponding signal conditioning electronics in a single low-temperature co-fired ceramic (LTCC) package. The developed sensor may be soldered onto an integrated electro-fluidic platform by using standard surface mount device (SMD) technology, e.g., as a standard electronic component would be on a printed circuit board, obviating the need for both wires and tubes and thus paving the road towards low-cost integrated electro-fluidic systems. Several performance aspects of this device are presented and discussed, together with electronics design issues. PMID:22163518

  11. Research Update: Direct conversion of amorphous carbon into diamond at ambient pressures and temperatures in air

    International Nuclear Information System (INIS)

    Narayan, Jagdish; Bhaumik, Anagh

    2015-01-01

    We report on fundamental discovery of conversion of amorphous carbon into diamond by irradiating amorphous carbon films with nanosecond lasers at room-temperature in air at atmospheric pressure. We can create diamond in the form of nanodiamond (size range <100 nm) and microdiamond (>100 nm). Nanosecond laser pulses are used to melt amorphous diamondlike carbon and create a highly undercooled state, from which various forms of diamond can be formed upon cooling. The quenching from the super undercooled state results in nucleation of nanodiamond. It is found that microdiamonds grow out of highly undercooled state of carbon, with nanodiamond acting as seed crystals

  12. Bifurcation and Nonlinear Dynamic Analysis of Externally Pressurized Double Air Films Bearing System

    Directory of Open Access Journals (Sweden)

    Cheng-Chi Wang

    2014-01-01

    Full Text Available This paper studies the chaotic and nonlinear dynamic behaviors of a rigid rotor supported by externally pressurized double air films (EPDAF bearing system. A hybrid numerical method combining the differential transformation method and the finite difference method is used to calculate pressure distribution of EPDAF bearing system and bifurcation phenomenon of rotor center orbits. The results obtained for the orbits of the rotor center are in good agreement with those obtained using the traditional finite difference approach. The results presented summarize the changes which take place in the dynamic behavior of the EPDAF bearing system as the rotor mass and bearing number are increased and therefore provide a useful guideline for the bearing system.

  13. Two-dimensional modeling of stepped planing hulls with open and pressurized air cavities

    Directory of Open Access Journals (Sweden)

    Konstantin I. Matveev

    2012-06-01

    Full Text Available A method of hydrodynamic discrete sources is applied for two-dimensional modeling of stepped planing surfaces. The water surface deformations, wetted hull lengths, and pressure distribution are calculated at given hull attitude and Froude number. Pressurized air cavities that improve hydrodynamic performance can also be modeled with the current method. Presented results include validation examples, parametric calculations of a single-step hull, effect of trim tabs, and performance of an infinite series of periodic stepped surfaces. It is shown that transverse steps can lead to higher lift-drag ratio, although at reduced lift capability, in comparison with a stepless hull. Performance of a multi-step configuration is sensitive to the wave pattern between hulls, which depends on Froude number and relative hull spacing.

  14. An Explosive Range Model Based on the Gas Composition, Temperature, and Pressure during Air Drilling

    Directory of Open Access Journals (Sweden)

    Xiangyu Fan

    2016-01-01

    Full Text Available Air drilling is low cost and effectively improves the penetration rate and causes minimal damage to liquid-sensitive pay zones. However, there is a potential downhole explosion when combustible gas mixed with drilling fluid reaches the combustible condition. In this paper, based on the underground combustion mechanism, an explosive range calculation model is established. This model couples the state equation and the empirical formula method, which considers the inert gas content, pressure, mixed gas component, and temperature. The result shows that increase of the inert gas content narrows the explosive range, while increase of the gas temperature and pressure improves the explosive range. A case in Chongqing, China, is used to validate the explosive range calculation model.

  15. Water pressure head and temperature impact on isoxaflutole degradation in crop residues and loamy surface soil under conventional and conservation tillage management.

    Science.gov (United States)

    Alletto, Lionel; Coquet, Yves; Bergheaud, Valérie; Benoit, Pierre

    2012-08-01

    Laboratory incubations were performed in order to evaluate the dissipation of the proherbicide isoxaflutole in seedbed layer soil samples from conventional and conservation tillage systems and in maize and oat residues left at the soil surface under conservation tillage. The effects of temperature and water pressure head on radiolabelled isoxaflutole degradation were studied for each sample for 21d. Mineralisation of isoxaflutole was low for all samples and ranged from 0.0% to 0.9% of applied (14)C in soil samples and from 0.0% to 2.4% of applied (14)C in residue samples. In soil samples, degradation half-life of isoxaflutole ranged from 9 to 26h, with significantly higher values under conservation tillage. In residue samples, degradation half-life ranged from 3 to 31h, with significantly higher values in maize residues, despite a higher mineralisation and bound residue formation than in oat residues. Whatever the sample, most of the applied (14)C remained extractable during the experiment and, after 21d, less than 15% of applied (14)C were unextractable. This extractable fraction was composed of diketonitrile, benzoic acid derivative and several unidentified metabolites, with one of them accounting for more than 17% of applied (14)C. This study showed that tillage system design, including crop residues management, could help reducing the environmental impacts of isoxaflutole. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Remote Sensing Global Surface Air Pressure Using Differential Absorption BArometric Radar (DiBAR)

    Science.gov (United States)

    Lin, Bing; Harrah, Steven; Lawrence, Wes; Hu, Yongxiang; Min, Qilong

    2016-01-01

    Tropical storms and severe weathers are listed as one of core events that need improved observations and predictions in World Meteorological Organization and NASA Decadal Survey (DS) documents and have major impacts on public safety and national security. This effort tries to observe surface air pressure, especially over open seas, from space using a Differential-absorption BArometric Radar (DiBAR) operating at the 50-55 gigahertz O2 absorption band. Air pressure is among the most important variables that affect atmospheric dynamics, and currently can only be measured by limited in-situ observations over oceans. Analyses show that with the proposed space radar the errors in instantaneous (averaged) pressure estimates can be as low as approximately 4 millibars (approximately 1 millibar under all weather conditions). With these sea level pressure measurements, the forecasts of severe weathers such as hurricanes will be significantly improved. Since the development of the DiBAR concept about a decade ago, NASA Langley DiBAR research team has made substantial progress in advancing the concept. The feasibility assessment clearly shows the potential of sea surface barometry using existing radar technologies. The team has developed a DiBAR system design, fabricated a Prototype-DiBAR (P-DiBAR) for proof-of-concept, conducted lab, ground and airborne P-DiBAR tests. The flight test results are consistent with the instrumentation goals. Observational system simulation experiments for space DiBAR performance based on the existing DiBAR technology and capability show substantial improvements in tropical storm predictions, not only for the hurricane track and position but also for the hurricane intensity. DiBAR measurements will lead us to an unprecedented level of the prediction and knowledge on global extreme weather and climate conditions.

  17. Influence of reduced air pressure methods on dye penetration in standardized voids.

    Science.gov (United States)

    Plotino, Gianluca; Grande, Nicola M; Manzulli, Nicola; Chiaradia, Giacomina; La Torre, Giuseppe; Somma, Francesco

    2007-02-01

    The objective of this study was to evaluate the influence of the moment when reduced pressure is applied on dye penetration patterns. Nine hundred and sixty glass capillary tubes of different inner diameter (0.3 mm and 0.8 mm), divided into 48 groups, were submerged into dye in 3 different positions (horizontally, opening upwards, and opening downwards) under different vacuum conditions (passive, 5 kPa, 35 kPa, 70 kPa reduced pressure). When reduced pressure was applied half of the groups were submerged into dye before and half of the groups after the application of reduced pressure. Linear dye penetration was measured. Univariate analysis was performed with Mann-Whitney U test and Kruskal-Wallis test to select variables to be included in the regression model. A multiple logistic regression analysis with backward elimination was performed to assess the influence of different covariates on linear dye penetration. The multivariate linear regression showed that the moment of vacuuming had the greatest positive effect on linear dye penetration value (beta = 10.6, P < .0001). Also the level of pressure reduction had a positive effect on the outcome variable (beta = 0.2, P < .0001) while the vertical positioning of the tubes has negatively affected the outcome variable both for the open end upside (beta = -1.01, P = .024) and the open end downside (beta = -1.05, P = .019). Diameter of the tubes (P = .442) and immersion time (P = .727) had no effect on the outcome of linear dye penetration. Even minimum air pressure reduction applied before immersion of the specimens allowed the dye to extensively penetrate the voids.

  18. Aerosols generated by releases of pressurized powders and solutions in static air

    Energy Technology Data Exchange (ETDEWEB)

    Sutter, S.L.

    1983-08-01

    Safety assessments and environmental impact statements for nuclear fuel cycle facilities require an estimate of potential airborne releases caused by accidents. Aerosols generated by accidents are being investigated by Pacific Northwest Laboratory to develop the source terms for these releases. An upper boundary accidental release event would be a pressurized release of powder or liquid in static air. Experiments were run using various source sizes and pressures and measuring the mass airborne and the particle size distribution of aerosols produced by these pressurized releases. Two powder and two liquid sources were used: TiO/sub 2/ and depleted uranium dioxide (DUO); and aqueous uranine (sodium fluorescein) and uranyl nitrate solutions. Results of the experiments showed that pressurization level and source size were significant variables for the airborne powder releases. For this experimental configuration, the liquid releases were a function of pressure, but volume did not appear to be a significant variable. During the experiments 100 g and 350 g of DUO (1 ..mu..m dia) and TiO/sub 2/ (1.7 ..mu..m dia) powders and 100 cm/sup 3/ and 350 cm/sup 3/ of uranine and uranyl nitrate solutions were released at pressures ranging from 50 to 500 psig. The average of the largest fractions of powder airborne was about 24%. The maximum amount of liquid source airborne was significantly less, about 0.15%. The median aerodynamic equivalent diameters (AED) for collected airborne powders ranged from 5 to 19 ..mu..m; liquids ranged from 2 to 29 ..mu..m. All of the releases produced a significant fraction of respirable particles of 10 ..mu..m and less. 12 references, 10 figures, 23 tables.

  19. Laser-based measurements of OH in high pressure CH4/air flames

    Science.gov (United States)

    Battles, B. E.; Hanson, R. K.

    1991-01-01

    Narrow-linewidth laser absorption measurements are reported from which mole fraction and temperature of OH are determined in high-pressure (1-10 atm), lean CH4/air flames. These measurements were made in a new high pressure combustion facility which incorporates a traversable flat flame burner, providing spatially and temporally uniform combustion gases at pressures up to 10 am. A commercially avialable CW ring dye laser was used with an intracavity doubling crystal to provide near-UV single mode output at approximately 306 nm. The UV beam was rapidly scanned over 120 GHz (0.1 sec scan duration) to resolve the absorption lineshape of the A-X (0,0) R1(7)/R1(11) doublet of the OH radical. From the doublet's absorption lineshape, the temperature was determined; and from peak absorption, Beer's Law was employed to find the mole fraction of OH. These data were obtained as a function of height above the flame at various pressures.

  20. Preliminary investigation of the effect of air-pollution-control residue from waste incineration on the properties of cement paste and mortar

    DEFF Research Database (Denmark)

    Geiker, Mette Rica; Kjeldsen, Ane Mette; Galluci, Emmanuel

    2006-01-01

    For preliminary assessment of the engineering properties of concrete with air-pollution-control residue from waste incineration (APC) the possible reactivity of APC and the effect of APC on cement hydration were investigated by isothermal calorimetry, chemical shrinkage (pychnometry), thermal...

  1. A Semi-Analytical Model for Calculating Touch-Point Pressure and Pull-in Voltage for Clamped Diaphragms with Residual Stress

    Directory of Open Access Journals (Sweden)

    Anurekha SHARMA

    2007-10-01

    Full Text Available A closed form model for evaluating touch point pressure and pull-in voltage of clamped square diaphragm with residual stress is proposed. Square diaphragms are used in numerous applications. The design parameters for all these structures are pull-in voltage and/or touchpoint pressure. The materials employed for fabricating diaphragms for these structures are p+ doped silicon, polysilicon, silicon nitride, polyimide etc. All these materials have residual stress, which influences the behavior of the transducer. In addition to this, a capacitive transducer may or may not employ an intervening layer of dielectric on the fixed electrode. Closed form expressions for evaluating touch-point pressure and pull-in voltage have been derived for such a structure by means of semi-analytical model. The method proposed is less complex and less time consuming in comparison with FEM tools.

  2. A study on the effects of system pressure on heat and mass transfer rates of an air cooler

    International Nuclear Information System (INIS)

    Jung, Hyung Ho

    2002-01-01

    In the present paper, the effects of inlet pressure on the heat and mass transfer rates of an air cooler are numerically predicted by a local analysis method. The pressures of the moist air vary from 2 to 4 bars. The psychometric properties such as dew point temperature, relative humidity and humidity ratio are employed to treat the condensing water vapor in the moist air when the surface temperatures are dropped below the dew point. The effects of the inlet pressures on the heat transfer rate, the dew point temperature, the rate of condensed water, the outlet temperature of air and cooling water are calculated. The condensation process of water vapor is discussed in detail. The results of present calculations are compared with the test data and shows good agreements

  3. Diffuse plasma treatment of polyamide 66 fabric in atmospheric pressure air

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lee, E-mail: leeli@mail.hust.edu.cn; Peng, Ming-yang; Teng, Yun; Gao, Guozhen

    2016-01-30

    Graphical abstract: - Highlights: • A cylindrical-electrode nanosecond-pulse diffuse-discharge reactor is presented. • Large-scale non-thermal plasmas were generated steadily in atmospheric air. • Treated PA66 fabric is etched with oxygen-containing group increases. • The hydrophily of treated PA66 fabric improves effectively. • Extending the treatment time is a method to reduce the treatment frequency. - Abstract: The polyamide 66 (PA66) fabrics are hard to be colored or glued in industrial production due to the poor hydrophily. Diffuse plasma is a kind of non-thermal plasma generated at atmospheric pressure in air. This paper proposes that large-scale diffuse plasma generated between wire electrodes can be employed for improving the hydrophily of PA66 fabrics. A repetitive nanosecond-pulse diffuse-discharge reactor using a cylindrical wire electrode configuration is presented, which can generate large-scale non-thermal plasmas steadily at atmospheric pressure without any barrier dielectric. Then the reactor is used to treat PA66 fabrics in different discharge conditions. The hydrophilicity property of modified PA66 is measured by wicking test method. The modified PA66 is also analyzed by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) to prove the surface changes in physical microstructure and chemical functional groups, respectively. What's more, the effects of treatment time and treatment frequency on surface modification are investigated and discussed.

  4. Diffuse plasma treatment of polyamide 66 fabric in atmospheric pressure air

    International Nuclear Information System (INIS)

    Li, Lee; Peng, Ming-yang; Teng, Yun; Gao, Guozhen

    2016-01-01

    Graphical abstract: - Highlights: • A cylindrical-electrode nanosecond-pulse diffuse-discharge reactor is presented. • Large-scale non-thermal plasmas were generated steadily in atmospheric air. • Treated PA66 fabric is etched with oxygen-containing group increases. • The hydrophily of treated PA66 fabric improves effectively. • Extending the treatment time is a method to reduce the treatment frequency. - Abstract: The polyamide 66 (PA66) fabrics are hard to be colored or glued in industrial production due to the poor hydrophily. Diffuse plasma is a kind of non-thermal plasma generated at atmospheric pressure in air. This paper proposes that large-scale diffuse plasma generated between wire electrodes can be employed for improving the hydrophily of PA66 fabrics. A repetitive nanosecond-pulse diffuse-discharge reactor using a cylindrical wire electrode configuration is presented, which can generate large-scale non-thermal plasmas steadily at atmospheric pressure without any barrier dielectric. Then the reactor is used to treat PA66 fabrics in different discharge conditions. The hydrophilicity property of modified PA66 is measured by wicking test method. The modified PA66 is also analyzed by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) to prove the surface changes in physical microstructure and chemical functional groups, respectively. What's more, the effects of treatment time and treatment frequency on surface modification are investigated and discussed.

  5. Pressure relief, cold foam or static air? A single center, prospective, controlled randomized clinical trial in a Dutch nursing home.

    Science.gov (United States)

    van Leen, Martin; Hovius, Steven; Neyens, Jacques; Halfens, Ruud; Schols, Jos

    2011-02-01

    At present, the evidence regarding the type of mattress that is the best for preventing pressure ulcers is not convincing. In a single center, prospective, controlled trial we compared a static air overlay mattress (no electric pump needed) on top of a cold foam mattress with a cold foam mattress alone on pressure ulcer incidence in nursing home residents. 83 Patients were included in the study with a score lower than 12 points on the Norton scale and no pressure ulcer at the start of the study. 42 Patients received a cold foam mattress and 41 patients received a static air overlay on top of that cold foam mattress. Out of bed we standardized the pressure reduction in sitting position by using a static air cushion in both groups. Patients were checked weekly in both groups for pressure ulcers. Only when there were signs of developing a pressure ulcer grade 2 or higher, repositioning by our nursing home pressure ulcer protocol (PU protocol) was put into practice. Seven patients (17.1%) on a cold foam mattress and two (4.8%) on a static air mattress developed a pressure ulcer grade 2 or more. There was no difference regarding pressure ulcer incidence between patients with a high risk (Norton 5-8) and patients with a medium risk (Norton 9-12). In 5 out of 7 patients who developed a pressure ulcer on a foam mattress the ulcers showed no healing using our PU protocol. In the static air group all pressure ulcers healed by regular treatment according to our PU protocol. In this study, static air overlay mattresses provided a better prevention than cold foam mattresses alone (4.8% versus 17.1%). The Norton scores of the patients in both groups did not change during the 6 month trial period. Our decision to use repositioning only when there were signs of a pressure ulcer seems to be acceptable when a static air overlay is in position. However, the score of 17.1% development (incidence) of pressure ulcers in the foam group may stress the need of repositioning when using only

  6. A Modified Triples Algorithm for Flush Air Data Systems that Allows a Variety of Pressure Port Configurations

    Science.gov (United States)

    Millman, Daniel R.

    2017-01-01

    Air Data Systems (FADS) are becoming more prevalent on re-entry vehicles, as evi- denced by the Mars Science Laboratory and the Orion Multipurpose Crew Vehicle. A FADS consists of flush-mounted pressure transducers located at various locations on the fore-body of a flight vehicle or the heat shield of a re-entry capsule. A pressure model converts the pressure readings into useful air data quantities. Two algorithms for converting pressure readings to air data have become predominant- the iterative Least Squares State Estimator (LSSE) and the Triples Algorithm. What follows herein is a new algorithm that takes advantage of the best features of both the Triples Algorithm and the LSSE. This approach employs the potential flow model and strategic differencing of the Triples Algorithm to obtain the defective flight angles; however, the requirements on port placement are far less restrictive, allowing for configurations that are considered optimal for a FADS.

  7. Air pollution from industrial swine operations and blood pressure of neighboring residents.

    Science.gov (United States)

    Wing, Steve; Horton, Rachel Avery; Rose, Kathryn M

    2013-01-01

    Industrial swine operations emit odorant chemicals including ammonia, hydrogen sulfide (H2S), and volatile organic compounds. Malodor and pollutant concentrations have been associated with self-reported stress and altered mood in prior studies. We conducted a repeated-measures study of air pollution, stress, and blood pressure in neighbors of swine operations. For approximately 2 weeks, 101 nonsmoking adult volunteers living near industrial swine operations in 16 neighborhoods in eastern North Carolina sat outdoors for 10 min twice daily at preselected times. Afterward, they reported levels of hog odor on a 9-point scale and measured their blood pressure twice using an automated oscillometric device. During the same 2- to 3-week period, we measured ambient levels of H2S and PM10 at a central location in each neighborhood. Associations between systolic and diastolic blood pressure (SBP and DBP, respectively) and pollutant measures were estimated using fixed-effects (conditional) linear regression with adjustment for time of day. PM10 showed little association with blood pressure. DBP [β (SE)] increased 0.23 (0.08) mmHg per unit of reported hog odor during the 10 min outdoors and 0.12 (0.08) mmHg per 1-ppb increase of H2S concentration in the same hour. SBP increased 0.10 (0.12) mmHg per odor unit and 0.29 (0.12) mmHg per 1-ppb increase of H2S in the same hour. Reported stress was strongly associated with BP; adjustment for stress reduced the odor-DBP association, but the H2S-SBP association changed little. Like noise and other repetitive environmental stressors, malodors may be associated with acute blood pressure increases that could contribute to development of chronic hypertension.

  8. Effect of non-thermal air atmospheric pressure plasma jet treatment on gingival wound healing

    Science.gov (United States)

    Lee, Jung-Hwan; Choi, Eun-Ha; Kim, Kwang-Mahn; Kim, Kyoung-Nam

    2016-02-01

    Non-thermal atmospheric pressure plasmas have been applied in the biomedical field for the improvement of various cellular activities. In dentistry, the healing of gingival soft tissue plays an important role in health and aesthetic outcomes. While the biomedical application of plasma has been thoroughly studied in dentistry, a detailed investigation of plasma-mediated human gingival fibroblast (HGF) migration for wound healing and its underlying biological mechanism is still pending. Therefore, the aim of this study is to apply a non-thermal air atmospheric pressure plasma jet (NTAAPPJ) to HGF to measure the migration and to reveal the underlying biological mechanisms involved in the migration. After the characterization of NTAAPPJ by optical emission spectroscopy, the adherent HGF was treated with NTAAPPJ or air with a different flow rate. Cell viability, lipid peroxidation, migration, intracellular reactive oxygen species (ROS), and the expression of migration-related genes (EGFR, PAK1, and MAPK3) were investigated. The level of statistical significance was set at 0.05. NTAAPPJ and air treatment with a flow rate of 250-1000 standard cubic centimetres per minute (sccm) for up to 30 s did not induce significant decreases in cell viability or membrane damage. A significant increase in the migration of mitomycin C-treated HGF was observed after 30 s of NTAAPPJ treatment compared to 30 s air-only treatment, which was induced by high levels of intracellular reactive oxygen species (ROS). An increase in migration-related gene expression and EGFR activation was observed following NTAAPPJ treatment in an air flow rate-dependent manner. This is the first report that NTAAPPJ treatment induces an increase in HGF migration without changing cell viability or causing membrane damage. HGF migration was related to an increase in intracellular ROS, changes in the expression of three of the migration-related genes (EGFR, PAK1, and MAPK1), and EGFR activation. Therefore

  9. Effect of non-thermal air atmospheric pressure plasma jet treatment on gingival wound healing

    International Nuclear Information System (INIS)

    Lee, Jung-Hwan; Choi, Eun-Ha; Kim, Kwang-Mahn; Kim, Kyoung-Nam

    2016-01-01

    Non-thermal atmospheric pressure plasmas have been applied in the biomedical field for the improvement of various cellular activities. In dentistry, the healing of gingival soft tissue plays an important role in health and aesthetic outcomes. While the biomedical application of plasma has been thoroughly studied in dentistry, a detailed investigation of plasma-mediated human gingival fibroblast (HGF) migration for wound healing and its underlying biological mechanism is still pending. Therefore, the aim of this study is to apply a non-thermal air atmospheric pressure plasma jet (NTAAPPJ) to HGF to measure the migration and to reveal the underlying biological mechanisms involved in the migration. After the characterization of NTAAPPJ by optical emission spectroscopy, the adherent HGF was treated with NTAAPPJ or air with a different flow rate. Cell viability, lipid peroxidation, migration, intracellular reactive oxygen species (ROS), and the expression of migration-related genes (EGFR, PAK1, and MAPK3) were investigated. The level of statistical significance was set at 0.05. NTAAPPJ and air treatment with a flow rate of 250–1000 standard cubic centimetres per minute (sccm) for up to 30 s did not induce significant decreases in cell viability or membrane damage. A significant increase in the migration of mitomycin C-treated HGF was observed after 30 s of NTAAPPJ treatment compared to 30 s air-only treatment, which was induced by high levels of intracellular reactive oxygen species (ROS). An increase in migration-related gene expression and EGFR activation was observed following NTAAPPJ treatment in an air flow rate-dependent manner. This is the first report that NTAAPPJ treatment induces an increase in HGF migration without changing cell viability or causing membrane damage. HGF migration was related to an increase in intracellular ROS, changes in the expression of three of the migration-related genes (EGFR, PAK1, and MAPK1), and EGFR activation. Therefore

  10. Pressure drop in packed beds of spherical particles at ambient and elevated air temperatures

    Directory of Open Access Journals (Sweden)

    Pešić Radojica

    2015-01-01

    Full Text Available The aim of this work was the experimental investigation of the particle friction factor for air flow through packed bed of particles at ambient and elevated temperatures. The experiments were performed by measuring the pressure drop across the packed bed, heated to the desired temperature by hot air. Glass spherical particles of seven different diameters were used. The temperature range of the air flowing through the packed bed was from 20ºC to 350ºC and the bed voidages were from 0.3574 to 0.4303. The obtained results were correlated using a number of available literature correlations. The overall best fit of all of the experimental data was obtained using Ergun [1] equation, with mean absolute deviation of 10.90%. Ergun`s equation gave somewhat better results in correlating the data at ambient temperature with mean absolute deviation of 9.77%, while correlation of the data at elevated temperatures gave mean absolute deviation of 12.38%. The vast majority of the correlations used gave better results when applied to ambient temperature data than to the data at elevated temperatures. Based on the results obtained, Ergun [1] equation is proposed for friction factor calculation both at ambient and at elevated temperatures. [Projekat Ministarstva nauke Republike Srbije, br. ON172022

  11. Air

    Science.gov (United States)

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

  12. Does high pressure have any effect on the structure of alpha amylase and its ability to binding to the oligosaccharides having 3-7 residues? Molecular dynamics study.

    Science.gov (United States)

    Vahidi, S Hooman; Bozorgmehr, Mohammad Reza; Morsali, Ali; Beyramabadi, S Ali

    2018-03-01

    Studies have shown that deletion of amino acids from the C-terminus of amylase do not alter its amylolytic activity. Although high pressure is used to modify the structure and function of this enzyme, the effects of high pressures on the structures of the wild-type and truncated amylases have not yet been understood at the molecular level. Using molecular dynamic simulations and docking, we studied the structures of wild-type and truncated Taka-amylases at high pressures (1000-4000 bar). To construct the truncated Taka-amylase, 50 and 100 C-terminal residues were removed in two separate steps. Results of simulation showed that, although the overall shape partly agglomerates with rise in pressure, high pressure fails to modify the structure of the barrel-like region of the β-sheet in the wild-type and truncated enzymes. A comparison of contact graphs revealed that the changes at the N-terminus were less extensive than those at the C-terminus. Further analysis showed that 10 regions of the secondary structures changed due to pressure change in wild-type amylase, of which 6 regions were associated with the loops and 4 with helix, while the structure of β-sheets remained unchanged. The docking of maltotriose, maltotetraose, maltopentaose, maltohexaose, and maltoheptaose with the averaged structures obtained from different simulations was conducted to characterize the influence of pressure on the activities of the wild-type and truncated enzymes. The results showed that maltoheptaose made hydrophobic contacts with residues Tyr238-Asp117-Tyr82-Leu166-Leu232-Tyr155 and hydrogen contacts with residues Asp233-Gly234-Asp206-Arg204-His296-Glu230. Similar results were obtained for other malto-oligosaccharides. Copyright © 2018 Elsevier Inc. All rights reserved.

  13. Effect of preemptive weld overlay sequence on residual stress distribution for dissimilar metal weld of Kori nuclear power plant pressurizer

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Hong Yeol; Song, Tae Kwang; Chun, Yun Bae; Oh, Chang Young; Kim, Yun Jae [Korea Univ., Seoul (Korea, Republic of); Lee, Kyoung Soo; Park, Chi Yong [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

    2008-07-01

    Weld overlay is one of the residual stress mitigation method which arrest crack. An overlay weld sued in this manner is termed a Preemptive Weld OverLay(PWOL). PWOL was good for distribution of residual stress of Dissimilar Metal Weld(DMW) by previous research. Because range of overlay welding is wide relatively, residual stress distribution on PWR is affected by welding sequence. In order to examine the effect of welding sequence, PWOL was applied to a specific DMW of KORI nuclear power plant by finite element analysis method. As a result, the welding direction that from nozzle to pipe is better good for residual stress distribution on PWR.

  14. Aircraft vibration and other factors related to high systolic blood pressure in Indonesian Air Force pilots

    Directory of Open Access Journals (Sweden)

    Minarma Siagian

    2013-05-01

    Indonesian Air Force pilots doing annual medical check-ups at the Saryanto Institute for Medical and Health Aviation and Aerospace (LAKESPRA from 2003 – 2008. The data extracted from medical records were age, total flight hours, type of aircraft, fasting blood glucose and cholesterol levels, waist circumference, height and weight (Body Mass Index, and blood pressure.Results: Of 336 pilots, there were 16 with systolic pressure  140 mmHg. The pilot who had high vibration than low vibration had 2.8-fold to be high systolic blood pressure [adjusted odds ratio (ORa = 2.83; 95%confidence interval (CI =1.16-22.04. In term of average flight hours, those who had average flight hours of 300-622 hours per year compared to 29-299 hours per year had 5-fold increased risk to be high systolic blood pressure (ORa = 5.05; 95% CI =1.16-22.04]. Furthermore, those who had high than normal resting pulse rate had 2.4 times to be high systolic blood pressure (ORa = 2.37; 95 CI =0.81-6.97; P = 0.115.Conclusion:High aircraft vibration, high average flight hours per year, and high resting pulse rate increase risk high systolic blood pressure in air force pilots.Keywords: systolic blood pressure, aircraft vibration, resting pulse rate, pilots

  15. A retrospective study to determine the incidence of pressure ulcers in burn patients using a low air loss pressure relieving mattress.

    Science.gov (United States)

    Still, Joseph M; Wilson, Joan; Rinker, Connie; Law, Edward; Craft-Coffman, Beretta

    2003-06-01

    In immobilized patients, unrelieved pressure can create decubitus ulcers over bony prominences. Those burn patients who require prolonged bed rest, are prone to the development of such problems. Various methods of reducing pressure on these areas, including frequent turning and the use of air fluidized and low air loss beds, have been adopted to attempt to prevent the development of this complication. The Pegasus Renaissance alternating pressure mattress is such a device, intended to reduce the incidence of decubitus ulcers. It was introduced at our burn unit and evaluated over a 29-month period. During the study period, 186 (13.4%) of 1390 acutely burned patients, believed to be at high risk for the development of decubiti, were placed on this mattress. Other patients were treated in the standard hospital bed. Care was otherwise the same. No decubitus ulcers developed in any of the patients treated on the Pegasus Renaissance mattress.

  16. Prospective evaluation of the self-pressurized air-Q intubating laryngeal airway in children.

    Science.gov (United States)

    Jagannathan, Narasimhan; Sohn, Lisa E; Mankoo, Ravinder; Langen, Kenneth E; Roth, Andrew G; Hall, Steven C

    2011-06-01

    To assess the clinical efficacy of the self-pressurized air-Q ILA™ (ILA-SP).   The purpose of this prospective audit was to evaluate the feasibility of the ILA-SP in clinical practice and generate data for future comparison trials. The ILA-SP is a new first-generation supraglottic airway for children with a self-adjusting cuff and lack of a pilot balloon. Over a 4-month period, 352 children with an ASA physical status of I-III, newborn to 18 years of age, undergoing various procedures were studied. Data points assessed included insertion success rates, airway leak pressures, quality of ventilation, and perioperative complications associated with the use of this device. In 349 of the 352 patients in this study, the ILA-SP was used successfully as a primary supraglottic airway device in a variety of patients. Three patients required conversion to a standard laryngeal mask airway or a tracheal tube. The mean initial airway leak pressure for all patients was 17.8 ± 5.4 cm H(2)O, and 20.4 ± 5.5 cm H(2)O when re-checked at 10 min, which was statistically significant (P bronchospasm) (n = 10), sore throat (n = 3), and blood staining on removal of the device (n = 1). There were no episodes of regurgitation, aspiration, or hoarseness. Acceptable clinical performance was demonstrated with the ILA-SP for a variety of procedures in infants and children with spontaneous and positive pressure ventilation. Future studies comparing this device to other supraglottic airways may provide useful information regarding the safety of the ILA-SP in pediatric clinical practice. © 2011 Blackwell Publishing Ltd.

  17. Theoretical Study on Synchronous Characterization of Surface and Interfacial Mechanical Properties of Thin-Film/Substrate Systems with Residual Stress Based on Pressure Blister Test Technique

    Directory of Open Access Journals (Sweden)

    Zhi-xin Yang

    2018-01-01

    Full Text Available In this study, based on the pressure blister test technique, a theoretical study on the synchronous characterization of surface and interfacial mechanical properties of thin-film/substrate systems with residual stress was presented, where the problem of axisymmetric deformation of a blistering film with initial stress was analytically solved and its closed-form solution was presented. The expressions to determine Poisson’s ratios, Young’s modulus, and residual stress of surface thin films were derived; the work done by the applied external load and the elastic energy stored in the blistering thin film were analyzed in detail and their expressions were derived; and the interfacial adhesion energy released per unit delamination area of thin-film/substrate (i.e., energy release rate was finally presented. The synchronous characterization technique presented here has theoretically made a big step forward, due to the consideration for the residual stress in surface thin films.

  18. Treatment of waste incinerator air-pollution-control residues with FeSO4: Laboratory investigation of design parameters

    DEFF Research Database (Denmark)

    Jensen, Dorthe Lærke; Christensen, Thomas Højlund; Lundtorp, Kasper

    2002-01-01

    The key design parameters of a new process for treatment of air-pollution-control (APC) residues (the Ferroxprocess) were investigated in the laboratory. The optimisation involved two different APC-residues from actual incinerator plants. The design parameters considered were: amount of iron oxide...... that an optimum process configuration could be obtained yielding a stabilised solid product with low leaching of heavy metals and a dischargable wastewater with high contents of salts (in order to remove salts from the solid product) and low concentrations of heavy metals. The amount of iron added to the APC...

  19. X-ray diffraction residual stress measurement in the rolled-joint zone of Zr - 2.5 % Nb pressure tube

    International Nuclear Information System (INIS)

    Dinu, A.; Nedelcu, L.

    1995-01-01

    The in-service experience of Zr - 2.5 % Nb pressure tubes in CANDU-type nuclear reactors has demonstrated very good performance over a long period of time. However, analyses done by AECL specialists on most failure cases, showed that a big percentage of defects are manufacturing defects, which appear mostly at the beginning of the rolled-joint zone. It has been observed that a correct rolling ensures an acceptable distribution of residual stress, but an incorrect one leads to an accumulation of big values of residual stress. This determines a preferential radial orientation of hydrides, which during operation in the reactor can produce DHC. To ensure a suitable performance of the Zr - 2.5 % Nb pressure tubes in the CANDU reactor, it is very important to have a correct rolling as mentioned in the procedure. This work presents a methodology for the measurement of the stressing state in the surfaces layers of the rolled-joint zone. The X-ray diffraction method can also be used for establishing the residual stress distribution across the tub wall, in order to ensure a good performance at Cernavoda nuclear plant. The results obtained for the investigated tube have led to the conclusion that the rolling process was correctly applied in this case, the values obtained for the residual stress being in good agreement with those accepted in literature. (Author) 2 Figs., 2 Tabs

  20. Electrodialytic removal of heavy metals and chloride from municipal solid waste incineration fly ash and air pollution control residue in suspension - test of a new two compartment experimental cell

    DEFF Research Database (Denmark)

    Kirkelund, Gunvor Marie; Magro, Cátia; Guedes, Paula

    2015-01-01

    Municipal solid waste incineration (MSWI) residues such as fly ash and air pollution control (APC) residues are classified as hazardous waste and disposed of, although they contain potential resources. The most problematic elements in MSWI residues are leachable heavy metals and salts. For reuse...... of MSWI residues in for instance concrete, the aim of remediation should be reduction of the heavy metal leaching, while at the same time keeping the alkaline pH, so the residue can replace cement. In this study a MSWI residues were subjected to electrodialytic remediation under various experimental...

  1. Tandem differential mobility spectrometry with ion dissociation in air at ambient pressure and temperature.

    Science.gov (United States)

    Menlyadiev, M R; Tarassov, A; Kielnecker, A M; Eiceman, G A

    2015-05-07

    Proton-bound dimers were dissociated to protonated monomers in air at ambient pressure and temperature using electric fields of ultrahigh Field Asymmetric Ion Mobility Spectrometry (ultraFAIMS) with the onset of dissociation for ethyl acetate as 96 Td and for dimethyl methyl phosphonate as 170 Td. Ions then were measured by differential mobility spectrometry (DMS). Fragment ions were formed with propyl acetate at electric fields of 90 Td or greater. The dissociation in ultraFAIMS of ions, with compensation fields near zero, to form smaller ions with new compensation fields, provided a method to improve peak capacity in DMS without gas modifiers. These findings also lay the foundation for a triple stage DMS with a centre stage for ion dissociation or fragmentation.

  2. Instabilities and soot formation in spherically expanding, high pressure, rich, iso-octane-air flames

    Energy Technology Data Exchange (ETDEWEB)

    Lockett, R D [School of Engineering and Mathematical Sciences, City University, Northampton Square, London EC1V OHB (United Kingdom)

    2006-07-15

    Flame instabilities, cellular structures and soot formed in high pressure, rich, spherically expanding iso-octane-air flames have been studied experimentally using high speed Schlieren cinematography, OH fluorescence, Mie scattering and laser induced incandescence. Cellular structures with two wavelength ranges developed on the flame surface. The larger wavelength cellular structure was produced by the Landau-Darrieus hydrodynamic instability, while the short wavelength cellular structure was produced by the thermal-diffusive instability. Large negative curvature in the short wavelength cusps caused local flame quenching and fracture of the flame surface. In rich flames with equivalence ratio {phi} > 1.8, soot was formed in a honeycomb-like structure behind flame cracks associated with the large wavelength cellular structure induced by the hydrodynamic instability. The formation of soot precursors through low temperature pyrolysis was suggested as a suitable mechanism for the initiation of soot formation behind the large wavelength flame cracks.

  3. Synthesis of ammonia directly from air and water at ambient temperature and pressure

    Science.gov (United States)

    Lan, Rong; Irvine, John T. S.; Tao, Shanwen

    2013-01-01

    The N≡N bond (225 kcal mol−1) in dinitrogen is one of the strongest bonds in chemistry therefore artificial synthesis of ammonia under mild conditions is a significant challenge. Based on current knowledge, only bacteria and some plants can synthesise ammonia from air and water at ambient temperature and pressure. Here, for the first time, we report artificial ammonia synthesis bypassing N2 separation and H2 production stages. A maximum ammonia production rate of 1.14 × 10−5 mol m−2 s−1 has been achieved when a voltage of 1.6 V was applied. Potentially this can provide an alternative route for the mass production of the basic chemical ammonia under mild conditions. Considering climate change and the depletion of fossil fuels used for synthesis of ammonia by conventional methods, this is a renewable and sustainable chemical synthesis process for future. PMID:23362454

  4. Integrated LTCC Pressure/Flow/Temperature Multisensor for Compressed Air Diagnostics†

    Directory of Open Access Journals (Sweden)

    Nicolas Craquelin

    2010-12-01

    Full Text Available We present a multisensor designed for industrial compressed air diagnostics and combining the measurement of pressure, flow, and temperature, integrated with the corresponding signal conditioning electronics in a single low-temperature co-fired ceramic (LTCC package. The developed sensor may be soldered onto an integrated electro-fluidic platform by using standard surface mount device (SMD technology, e.g., as a standard electronic component would be on a printed circuit board, obviating the need for both wires and tubes and thus paving the road towards low-cost integrated electro-fluidic systems. Several performance aspects of this device are presented and discussed, together with electronics design issues.

  5. Impact of ventilation/pressurization on indoor air contaminants in schools

    International Nuclear Information System (INIS)

    Shaughnessy, R.J.; Levetin, E.; Fisher, E.J.; Ligman, B.K.

    1993-01-01

    As part of a continuing technology development effort to control radon in schools, The U.S. Environmental Protection Agency's (EPA) School Evaluation Program (SEP) team in cooperation with U.S. EPA's Region 6 office has performed radon mitigation in two Southwestern United States schools utilizing the method of ventilation/pressurization control technology. Schools were inspected and IAQ measurements made with respect to carbon dioxide, bioaerosols, volatile organic compounds, and respirable particles. Premitigation results indicated poor ventilation conditions existed throughout the school buildings. Elevated levels of respirable particles were measured, yet no conclusions with respect to health could be implied. Post-mitigation results support, but do not prove the hypothesis that improved ventilation to control radon will also reduce other indicator indoor air contaminants. (orig.). (9 refs., 4 tabs.)

  6. Synthesis of ammonia directly from air and water at ambient temperature and pressure.

    Science.gov (United States)

    Lan, Rong; Irvine, John T S; Tao, Shanwen

    2013-01-01

    The N≡N bond (225 kcal mol⁻¹) in dinitrogen is one of the strongest bonds in chemistry therefore artificial synthesis of ammonia under mild conditions is a significant challenge. Based on current knowledge, only bacteria and some plants can synthesise ammonia from air and water at ambient temperature and pressure. Here, for the first time, we report artificial ammonia synthesis bypassing N₂ separation and H₂ production stages. A maximum ammonia production rate of 1.14 × 10⁻⁵ mol m⁻² s⁻¹ has been achieved when a voltage of 1.6 V was applied. Potentially this can provide an alternative route for the mass production of the basic chemical ammonia under mild conditions. Considering climate change and the depletion of fossil fuels used for synthesis of ammonia by conventional methods, this is a renewable and sustainable chemical synthesis process for future.

  7. Implementation of pressurized air injection system in a Kaplan prototype for the reduction of vibration caused by tip vortex cavitation

    Science.gov (United States)

    Rivetti, A.; Angulo, M.; Lucino, C.; Hene, M.; Capezio, O.; Liscia, S.

    2016-11-01

    Blade tip cavitation is a well-known phenomenon that affects the performance of large-diameter Kaplan turbines and induces structural vibration. Injection of pressurized air has been found to yield promising results in reducing those damaging effects. In this work, the results of an experimental test of air injection on a 9.5-m-diameter Kaplan turbine are reported. Experiments were performed for several load conditions and for two different net heads. Accelerations, pressure pulsation and noise emission were monitored for every tested condition. Results show that, at the expense of a maximum efficiency drop of 0.2%, air injection induces a decrease on the level of vibration from 57% up to 84%, depending on the load condition. Such decrease is seen to be proportional to the air flow rate, in the range from 0.06 to 0.8‰ (respect to the discharge at the best efficiency point).

  8. Application of microwave air plasma in the destruction of trichloroethylene and carbon tetrachloride at atmospheric pressure.

    Science.gov (United States)

    Rubio, S J; Quintero, M C; Rodero, A

    2011-02-15

    In this study, the destruction rate of a volatile waste destruction system based on a microwave plasma torch operating at atmospheric pressure was investigated. Atmospheric air was used to maintain the plasma and was introduced by a compressor, which resulted in lower operating costs compared to other gases such as argon and helium. To isolate the output gases and control the plasma discharge atmosphere, the plasma was coupled to a reactor. The effect of the gas flow rate, microwave power and initial concentration of compound on the destruction efficiency of the system was evaluated. In this study, trichloroethylene and carbon tetrachloride were used as representative volatile organic compounds to determine the destruction rate of the system. Based on the experimental results, at an applied microwave power less than 1000 W, the proposed system can reduce input concentrations in the ppmv range to output concentrations at the ppbv level. High air flow rates and initial concentrations produced energy efficiency values greater than 1000 g/kW h. The output gases and species present in the plasma were analysed by gas chromatography and optical emission spectroscopy, respectively, and negligible amounts of halogenated compounds resulting from the cleavage of C(2)HCl(3) and CCl(4) were observed. The gaseous byproducts of decomposition consisted mainly of CO(2), NO and N(2)O, as well as trace amounts of Cl(2) and solid CuCl. Copyright © 2010 Elsevier B.V. All rights reserved.

  9. Surface treatment of aramid fiber by air dielectric barrier discharge plasma at atmospheric pressure

    International Nuclear Information System (INIS)

    Jia Caixia; Chen Ping; Liu Wei; Li Bin; Wang Qian

    2011-01-01

    Aramid fiber samples are treated by air dielectric barrier discharge (DBD) plasma at atmospheric pressure; the plasma treatment time is investigated as the major parameter. The effects of this treatment on the fiber surface physical and chemical properties are studied by using surface characterization techniques. Scanning electron microscopy (SEM) is performed to determine the surface morphology changes, X-ray photoelectron spectroscopy (XPS) is analyzed to reveal the surface chemical composition variations and dynamic contact angle analysis (DCAA) is used to examine the changes of the fiber surface wettability. In addition, the wetting behavior of a kind of thermoplastic resin, poly(phthalazinone ether sulfone ketone) (PPESK), on aramid fiber surface is also observed by SEM photos. The study shows that there seems to be an optimum treatment condition for surface modification of aramid fiber by the air DBD plasma. In this paper, after the 12 s, 27.6 W/cm 3 plasma treatment the aramid fiber surface roughness is significantly improved, some new oxygen-containing groups such as C-O, C=O and O=C-O are generated on the fiber surface and the fiber surface wettability is greatly enhanced, which results in the better wetting behavior of PPESK resin on the plasma-treated aramid fiber.

  10. Influence of the Steam Addition on Premixed Methane Air Combustion at Atmospheric Pressure

    Directory of Open Access Journals (Sweden)

    Mao Li

    2017-07-01

    Full Text Available Steam-diluted combustion in gas turbine systems is an effective approach to control pollutant emissions and improve the gas turbine efficiency. The primary purpose of the present research is to analyze the influence of steam dilution on the combustion stability, flame structures, and CO emissions of a swirl-stabilized gas turbine model combustor under atmospheric pressure conditions. The premixed methane/air/steam flame was investigated with three preheating temperatures (384 K/434 K/484 K and the equivalence ratio was varied from stoichiometric conditions to the flammability limits where the flame was physically blown out from the combustor. In order to represent the steam dilution intensity, the steam fraction Ω defined as the steam to air mass flow rate ratio was used in this work. Exhaust gases were sampled with a water-cooled emission probe which was mounted at the combustor exit. A 120 mm length quartz liner was used which enabled the flame visualization and optical measurement. Time-averaged CH chemiluminescence imaging was conducted to characterize the flame location and it was further analyzed with the inverse Abel transform method. Chemical kinetics calculation was conducted to support and analyze the experimental results. It was found that the LBO (lean blowout limits were increased with steam fraction. CH chemiluminescence imaging showed that with a high steam fraction, the flame length was elongated, but the flame structure was not altered. CO emissions were mapped as a function of the steam fraction, inlet air temperature, and equivalence ratios. Stable combustion with low CO emission can be achieved with an appropriate steam fraction operation range.

  11. Effect of airstream velocity on mean drop diameters of water sprays produced by pressure and air atomizing nozzles

    Science.gov (United States)

    Ingebo, R. D.

    1977-01-01

    A scanning radiometer was used to determine the effect of airstream velocity on the mean drop diameter of water sprays produced by pressure atomizing and air atomizing fuel nozzles used in previous combustion studies. Increasing airstream velocity from 23 to 53.4 meters per second reduced the Sauter mean diameter by approximately 50 percent with both types of fuel nozzles. The use of a sonic cup attached to the tip of an air assist nozzle reduced the Sauter mean diameter by approximately 40 percent. Test conditions included airstream velocities of 23 to 53.4 meters per second at 293 K and atmospheric pressure.

  12. Surface treatment of polyethylene terephthalate film using atmospheric pressure glow discharge in air

    International Nuclear Information System (INIS)

    Fang Zhi; Qiu Yuchang; Wang Hui

    2004-01-01

    Non-thermal plasmas under atmospheric pressure are of great interest in polymer surface processing because of their convenience, effectiveness and low cost. In this paper, the treatment of Polyethylene terephthalate (PET) film surface for improving hydrophilicity using the non-thermal plasma generated by atmospheric pressure glow discharge (APGD) in air is conducted. The discharge characteristics of APGD are shown by measurement of their electrical discharge parameters and observation of light-emission phenomena, and the surface properties of PET before and after the APGD treatment are studied using contact angle measurement, x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It is found that the APGD is homogeneous and stable in the whole gas gap, which differs from the commonly filamentary dielectric barrier discharge (DBD). A short time (several seconds) APGD treatment can modify the surface characteristics of PET film markedly and uniformly. After 10 s APGD treatment, the surface oxygen content of PET surface increases to 39%, and the water contact angle decreases to 19 degree, respectively. (authors)

  13. Interaction of Atmospheric-Pressure Air Microplasmas with Amino Acids as Fundamental Processes in Aqueous Solution.

    Directory of Open Access Journals (Sweden)

    Renwu Zhou

    Full Text Available Plasma medicine is a relatively new field that investigates potential applications of cold atmospheric-pressure plasmas in bioengineering, such as for bacterial inactivation and degradation of organic molecules in water. In order to enunciate mechanisms of bacterial inactivation at molecular or atomic levels, we investigated the interaction of atmospheric-pressure air microplasmas with amino acids in aqueous solution by using high-resolution mass spectrometry (HRMS. Results show that the oxidation effect of plasma-induced species on the side chains of the amino acids can be categorized into four types, namely hydroxylation, nitration, dehydrogenation and dimerization. In addition, relative activities of amino acids resulting from plasma treatment come in descending order as follows: sulfur-containing carbon-chain amino acids > aromatic amino acids > five-membered ring amino acids > basic carbon-chain amino acids. Since amino acids are building blocks of proteins vital to the growth and reproduction of bacteria, these results provide an insight into the mechanism of bacterial inactivation by plasma.

  14. Interaction of Atmospheric-Pressure Air Microplasmas with Amino Acids as Fundamental Processes in Aqueous Solution.

    Science.gov (United States)

    Zhou, Renwu; Zhou, Rusen; Zhuang, Jinxing; Zong, Zichao; Zhang, Xianhui; Liu, Dongping; Bazaka, Kateryna; Ostrikov, Kostya

    2016-01-01

    Plasma medicine is a relatively new field that investigates potential applications of cold atmospheric-pressure plasmas in bioengineering, such as for bacterial inactivation and degradation of organic molecules in water. In order to enunciate mechanisms of bacterial inactivation at molecular or atomic levels, we investigated the interaction of atmospheric-pressure air microplasmas with amino acids in aqueous solution by using high-resolution mass spectrometry (HRMS). Results show that the oxidation effect of plasma-induced species on the side chains of the amino acids can be categorized into four types, namely hydroxylation, nitration, dehydrogenation and dimerization. In addition, relative activities of amino acids resulting from plasma treatment come in descending order as follows: sulfur-containing carbon-chain amino acids > aromatic amino acids > five-membered ring amino acids > basic carbon-chain amino acids. Since amino acids are building blocks of proteins vital to the growth and reproduction of bacteria, these results provide an insight into the mechanism of bacterial inactivation by plasma.

  15. Cycling of weathered chlordane residues in the environment: compositional and chiral profiles in contiguous soil, vegetation, and air compartments.

    Science.gov (United States)

    Mattina, MaryJane Incorvia; White, Jason; Eitzer, Brian; Iannucci-Berger, William

    2002-02-01

    Technical chlordane, a synthetic organic pesticide composed of 147 separate components, some of which exhibit optical activity, was used as an insecticide, herbicide, and termiticide prior to all uses being banned in the United States in 1988. It has been shown that food crops grown in soil treated decades earlier with technical chlordane translocate the weathered chlordane residues from the soil into root and aerial plant tissues. A rigorous analytical method is presented for the simultaneous, quantitative determination of both achiral and chiral components of technical chlordane in soil, plant, and air compartments using chiral gas chromatography interfaced to ion trap mass spectrometry and internal standard calibration. Using this method, we have observed differences in both the absolute and the relative amounts of trans- and cis-chlordane enantiomers and achiral trans-nonachlor between the soil compartment and various plant tissue compartments for several field-grown food crops. Changes in the relative amounts of the (+) and (-) enantiomers of trans- and cis-chlordane indicate enantioselective processes are in effect in the contiguous compartments of soil, plant roots, and aerial plant tissues. The data for zucchini (Cucurbita pepo L.), in particular, show an approximate fivefold enhancement in absolute concentration for total trans-chlordane, an eightfold concentration enhancement for total cis-chlordane, and a 2.5-fold enhancement for trans-nonachlor in the root relative to the soil matrix, the largest enhancements of any crop studied. This is the first comprehensive report of enantioselective processes into and through plant tissues for a variety of field-grown food crops. The selectivity will be related to observed insect toxicities of the enantiomers.

  16. Dual-pump CARS of Air in a Heated Pressure Vessel up to 55 Bar and 1300 K

    Science.gov (United States)

    Cantu, Luca; Gallo, Emanuela; Cutler, Andrew D.; Danehy, Paul M.

    2014-01-01

    Dual-pump Coherent anti-Stokes Raman scattering (CARS) measurements have been performed in a heated pressure vessel at NASA Langley Research Center. Each measurement, consisting of 500 single shot spectra, was recorded at a fixed location in dry air at various pressures and temperatures, in a range of 0.03-55×10(exp 5) Pa and 300-1373 K, where the temperature was varied using an electric heater. The maximum output power of the electric heater limited the combinations of pressures and temperatures that could be obtained. Charts of CARS signal versus temperature (at constant pressure) and signal versus pressure (at constant temperature) are presented and fit with an empirical model to validate the range of capability of the dual-pump CARS technique; averaged spectra at different conditions of pressure and temperature are also shown.

  17. Do sudden air temperature and pressure changes affect cardiovascular morbidity and mortality?

    Science.gov (United States)

    Plavcová, E.; Davídkovová, H.; Kyselý, J.

    2012-04-01

    Previous studies have shown that sudden changes in weather (usually represented by air temperature and/or pressure) are associated with increases in daily mortality. Little is understood about physiological mechanisms responsible for the impacts of weather changes on mortality, and whether similar patterns appear for morbidity as well. Relatively little is known also about differences in the magnitude of the mortality response in provincial regions and in cities, where the impacts may be exacerbated by air pollution effects and/or heat island. The present study examines the effects of sudden air temperature and pressure changes on morbidity (represented by hospital admissions) and mortality due to cardiovascular diseases in the population of the Czech Republic (approx. 10 million inhabitants) and separately in the city of Prague (1.2 million inhabitants). The events are selected from data covering 1994-2009 using the methodology introduced by Plavcová and Kyselý (2010), and they are compared with the datasets on hospital admissions and daily mortality (both standardized to account for long-term changes and the seasonal and weekly cycles). Relative deviations of morbidity/mortality from the baseline were averaged over the selected events for days D-2 (2 days before a change) up to D+7 (7 days after), and their statistical significance was tested by means of the Monte Carlo method. The study aims at (i) identifying those weather changes associated with increased cardiovascular morbidity/mortality, separately in summer and winter, (ii) comparing the effects of weather changes on morbidity and mortality, (iii) identifying whether urban population of Prague is more/less vulnerable in comparison to the population of the whole Czech Republic, (iv) comparing the effects for different cardiovascular diseases (ischaemic heart diseases, ICD-10 codes I20-I25; cerebrovascular diseases, I60-I69; hypertension, I10; atherosclerosis, I70) and individual population groups (by age

  18. 78 FR 1735 - Airworthiness Directives; Honeywell International Inc. Air Data Pressure Transducers

    Science.gov (United States)

    2013-01-09

    ...), air data computers, air data attitude heading reference systems, and digital air data computers... (ADAHRS), and digital air data computers (DADC) having the part numbers and serial numbers identified in...) Viking Air Limited (Type Certificate previously held by Bombardier Inc.; de Havilland, Inc.) Model (Twin...

  19. Multi-stage versus single-stage inflation and deflation cycle for alternating low pressure air mattresses to prevent pressure ulcers in hospitalised patients: a randomised-controlled clinical trial.

    Science.gov (United States)

    Demarré, L; Beeckman, D; Vanderwee, K; Defloor, T; Grypdonck, M; Verhaeghe, S

    2012-04-01

    The duration and the amount of pressure and shear must be reduced in order to minimize the risk of pressure ulcer development. Alternating low pressure air mattresses with multi-stage inflation and deflation cycle of the air cells have been developed to relieve pressure by sequentially inflating and deflating the air cells. Evidence about the effectiveness of this type of mattress in clinical practice is lacking. This study aimed to compare the effectiveness of an alternating low pressure air mattress that has a standard single-stage inflation and deflation cycle of the air cells with an alternating low pressure air mattress with multi-stage inflation and deflation cycle of the air cells. A randomised controlled trial was performed in a convenience sample of 25 wards in five hospitals in Belgium. In total, 610 patients were included and randomly assigned to the experimental group (n=298) or the control group (n=312). In the experimental group, patients were allocated to an alternating low pressure air mattress with multi-stage inflation and deflation cycle of the air cells. In the control group, patients were allocated to an alternating low pressure air mattress with a standard single-stage inflation and deflation cycle of the air cells. The outcome was defined as cumulative pressure ulcer incidence (Grade II-IV). An intention-to-treat analysis was performed. There was no significant difference in cumulative pressure ulcer incidence (Grade II-IV) between both groups (Exp.=5.7%, Contr.=5.8%, p=0.97). When patients developed a pressure ulcer, the median time was 5.0 days in the experimental group (IQR=3.0-8.5) and 8.0 days in the control group (IQR=3.0-8.5) (Mann-Whitney U-test=113, p=0.182). The probability to remain pressure ulcer free during the observation period in this trial did not differ significantly between the experimental group and the control group (log-rank χ(2)=0.013, df=1, p=0.911). An alternating low pressure air mattress with multi-stage inflation

  20. The effect of ammonium partial pressure on residual stresses in surface layer of SW7M HSS steel after vacuum nitriding 'NITROVAC'79'

    International Nuclear Information System (INIS)

    Gawronski, Z.

    1997-01-01

    The effect of the nitriding atmosphere on the residual stresses in the surface layer of the SW7M HSS steel has been investigated in the work. It has been proved that the pressure influences the distribution of those stresses to a great extent. At lower pressures (20 hPa and 40 hPa) at which only one zone is being created - the one of internal nitriding, without that of ε type nitrides on the surface - the highest residual stresses are operating on the HSS steel surface itself or eventually in the subsurface region very close to the surface. In the difference, in case of higher pressure (120 hPa and 240 hPa), the highest stresses are operating at great depth 8-12 μm from the steel surface - depending on the thickness of the ε type nitride layer created on the steel surface at those pressure. All the relevant stresses are compressive one. (author). 6 refs, 4 figs, 1 tab

  1. Mass-loss rates from decomposition of plant residues in spruce forests near the northern tree line subject to strong air pollution.

    Science.gov (United States)

    Lukina, Natalia V; Orlova, Maria A; Steinnes, Eiliv; Artemkina, Natalia A; Gorbacheva, Tamara T; Smirnov, Vadim E; Belova, Elena A

    2017-08-01

    Mass-loss rates during the early phase of decomposition of plant residues were studied for a period of 3 years in Norway spruce forests subjected to air pollution by Cu-Ni smelters on the Kola Peninsula, northwest Russia. Litterbags were deployed in two main patches of forests at the northern tree line, between and below the crowns of spruce trees older than 100 years. The study results demonstrated the dependence of the decomposition rates on the initial concentrations of nutrients and the C/N and lignin/N ratios in plant residues. Lower rates of mass loss in forests subject to air pollution may be related to low quality of plant residues, i.e. high concentrations of heavy metals, low concentrations of nutrients, and high lignin/N and C/N ratios. The increased losses of Ca, Mg, K, and Mn from plant residues in these forests compared to the reference were, probably, related to leaching of their compounds from the residues. The relatively high rates of heavy metal accumulation in the residues were most likely related to uptake of pollutants from the atmosphere, as well as to the lower mass-loss rates. The present study results demonstrate that the forest patchiness should be taken into account in assessment and predictions of decomposition rates in Norway spruce forests. Mass-loss rates of plant residues below the crowns of old spruce trees were significantly lower than those in the patches between the crowns. This was explained by the high C/N and lignin/N ratios in the residues of evergreens which contribute significantly to litterfall below the crowns and by lower soil temperature during winter and spring below the crowns. In addition, a lower amount of precipitation reaching the forest floor below the dense, long crowns of old Norway spruce trees may result in considerably lower washing out of the organic compounds from the residues. Lower mass-loss rates below the crowns of old spruce trees may be part of the evidence that the old-growth spruce forests can

  2. Room-Temperature Pressure-Induced Optically-Actuated Fabry-Perot Nanomechanical Resonator with Multilayer Graphene Diaphragm in Air.

    Science.gov (United States)

    Li, Cheng; Lan, Tian; Yu, Xiyu; Bo, Nan; Dong, Jingyu; Fan, Shangchun

    2017-11-04

    We demonstrated a miniature and in situ ~13-layer graphene nanomechanical resonator by utilizing a simple optical fiber Fabry-Perot (F-P) interferometric excitation and detection scheme. The graphene film was transferred onto the endface of a ferrule with a 125-μm inner diameter. In contrast to the pre-tension induced in membrane that increased quality ( Q ) factor to ~18.5 from ~3.23 at room temperature and normal pressure, the limited effects of air damping on resonance behaviors at 10 -2 and 10⁵ Pa were demonstrated by characterizing graphene F-P resonators with open and micro-air-gap cavities. Then in terms of optomechanical behaviors of the resonator with an air micro-cavity configuration using a polished ferrule substrate, measured resonance frequencies were increased to the range of 509-542 kHz from several kHz with a maximum Q factor of 16.6 despite the lower Knudsen number ranging from 0.0002 to 0.0006 in damping air over a relative pressure range of 0-199 kPa. However, there was the little dependence of Q on resonance frequency. Note that compared with the inferior F-P cavity length response to applied pressures due to interfacial air leakage, the developed F-P resonator exhibited a consistent fitted pressure sensitivity of 1.18 × 10⁵ kHz³/kPa with a good linearity error of 5.16% in the tested range. These measurements shed light on the pre-stress-dominated pressure-sensitive mechanisms behind air damping in in situ F-P resonant sensors using graphene or other 2D nanomaterials.

  3. Room-Temperature Pressure-Induced Optically-Actuated Fabry-Perot Nanomechanical Resonator with Multilayer Graphene Diaphragm in Air

    Directory of Open Access Journals (Sweden)

    Cheng Li

    2017-11-01

    Full Text Available We demonstrated a miniature and in situ ~13-layer graphene nanomechanical resonator by utilizing a simple optical fiber Fabry-Perot (F-P interferometric excitation and detection scheme. The graphene film was transferred onto the endface of a ferrule with a 125-μm inner diameter. In contrast to the pre-tension induced in membrane that increased quality (Q factor to ~18.5 from ~3.23 at room temperature and normal pressure, the limited effects of air damping on resonance behaviors at 10−2 and 105 Pa were demonstrated by characterizing graphene F-P resonators with open and micro-air-gap cavities. Then in terms of optomechanical behaviors of the resonator with an air micro-cavity configuration using a polished ferrule substrate, measured resonance frequencies were increased to the range of 509–542 kHz from several kHz with a maximum Q factor of 16.6 despite the lower Knudsen number ranging from 0.0002 to 0.0006 in damping air over a relative pressure range of 0–199 kPa. However, there was the little dependence of Q on resonance frequency. Note that compared with the inferior F-P cavity length response to applied pressures due to interfacial air leakage, the developed F-P resonator exhibited a consistent fitted pressure sensitivity of 1.18 × 105 kHz3/kPa with a good linearity error of 5.16% in the tested range. These measurements shed light on the pre-stress-dominated pressure-sensitive mechanisms behind air damping in in situ F-P resonant sensors using graphene or other 2D nanomaterials.

  4. Computational simulation of reactive species production by methane-air DBD at high pressure and high temperature

    Science.gov (United States)

    Takana, H.; Tanaka, Y.; Nishiyama, H.

    2012-01-01

    Computational simulations of a single streamer in DBD in lean methane-air mixture at pressure of 1 and 3 atm and temperature of 300 and 500 K were conducted for plasma-enhanced chemical reactions in a closed system. The effects of surrounding pressure and temperature are characterized for reactive species production by a DBD discharge. The results show that the production characteristics of reactive species are strongly influenced by the total gas number density and the higher concentration of reactive species are produced at higher pressure and lower gas temperature for a given initial reduced electric field.

  5. Thermal treatment of stabilized air pollution control residues in a waste incinerator pilot plant. Part 1: Fate of elements and dioxins.

    Science.gov (United States)

    Bergfeldt, Brita; Jay, Klaus; Seifert, Helmuth; Vehlow, Jürgen; Christensen, Thomas H; Baun, Dorthe L; Mogensen, Erhardt P B

    2004-02-01

    Air pollution control (APC) residues from municipal solid waste incinerator plants that are treated by means of the Ferrox process can be more safely disposed of due to reduction of soluble salts and stabilization of heavy metals in an iron oxide matrix. Further stabilization can be obtained by thermal treatment inside a combustion chamber of a municipal solid waste incinerator. The influence of the Ferrox products on the combustion process, the quality of the residues, and the partitioning of heavy metals between the various solids and the gas have been investigated in the Karlsruhe TAM-ARA pilot plant for waste incineration. During the experiments only few parameters were influenced. An increase in the SO2 concentration in the raw gas and slightly lower temperatures in the fuel bed could be observed compared with reference tests. Higher contents of Fe and volatile heavy metals such as Zn, Cd, Pb and partly Hg in the Ferrox products lead to increased concentration of these elements in the solid residues of the co-feeding tests. Neither the burnout nor the PCDD/F formation was altered by the addition of the Ferrox products. Co-feeding of treated APC residues seems to be a feasible approach for obtaining a single solid residue from waste incineration.

  6. Soot Oxidation in Laminar Hydrocarbon/Air Diffusion Flames at Atmospheric Pressure. Appendix D

    Science.gov (United States)

    Xu, F.; El-Leathy, A. M.; Faeth, G. M.

    2000-01-01

    Soot oxidation was studied experimentally in laminar hydrocarbon/air diffusion flames at atmospheric pressure. Measurements were carried out along the axes of round jets burning in coflowing air considering acetylene, ethylene, proplyene and propane as fuels. Measurements were limited to the initial stages of soot oxidation (carbon consumption less than 70%) where soot oxidation mainly occurs at the surface of primary soot particles. The following properties were measured as a function of distance above the burner exit: soot concentrations by deconvoluted laser extinction, soot temperatures by deconvoluted multiline emission, soot structure by thermophoretic sampling and analysis using Transmission Electron Microscopy (TEM), concentrations of stable major gas species (N2, H2O, H2, 02, CO, CO2, CH4, C2H2, C2H4, C2H6, C3H6, and C3H8) by sampling and gas chromatography, concentrations of some radical species (H, OH, O) by the deconvoluted Li/LiOH atomic absorption technique and flow velocities by laser velocimetry. It was found that soot surface oxidation rates are not particularly affected by fuel type for laminar diffusion flames and are described reasonably well by the OH surface oxidation mechanism with a collision efficiency of 0.10, (standard deviation of 0.07) with no significant effect of fuel type in this behavior; these findings are in good agreement with the classical laminar premixed flame measurements of Neoh et al. Finally, direct rates of surface oxidation by O2 were small compared to OH oxidation for present conditions, based on estimated O2 oxidation rates due to Nagle and Strickland-Constable, because soot oxidation was completed near the flame sheet where O2 concentrations were less than 1.2% by volume.

  7. Soot Oxidation in Hydrocarbon/Air Diffusion Flames at Atmospheric Pressure. Appendix K

    Science.gov (United States)

    Xu, F.; El-Leathy, A. M.; Faeth, G. M.; Urban, D. L. (Technical Monitor); Yuan, Z.-G. (Technical Monitor)

    2001-01-01

    Soot oxidation was studied experimentally in laminar hydrocarbon/air diffusion flames at atmospheric pressure. Measurements were carried out along the axes of round jets burning in coflowing air considering acetylene, ethylene, propylene and propane as fuels. Measurements were limited to the initial stages of soot oxidation (carbon consumption less than 70%) where soot oxidation mainly occurs at the surface of primary soot particles. The following properties were measured as a function of distance above the burner exit: soot concentrations by deconvoluted laser extinction, soot temperatures by deconvoluted multiline emission, soot structure by thermophoretic sampling and analysis using Transmission Electron Microscopy (TEM), concentrations of stable major gas species (N2, H2O, H2, O2, CO, CO2, CH4, C2H2,C2H4, C2H6, C3H6, and C3H8) by sampling and gas chromatography, concentrations of some radical species (H, OH, O) by the deconvoluted Li/LiOH atomic absorption technique and flow velocities by laser velocimetry. It was found that soot surface oxidation rates are not particularly affected by fuel type for laminar diffusion flames and are described reasonably well by the OH surface oxidation mechanism with a collision efficiency of 0.10, (standard deviation of 0.07) with no significant effect of fuel type in this behavior; these findings are in good agreement with the classical laminar premixed flame measurements of Neoh et al. Finally, direct rates of surface oxidation by O2 were small compared to OH oxidation for present conditions, based on estimated O2 oxidation rates due to Nagle and Strickland-Constable (1962), because soot oxidation was completed near the flame sheet where O2 concentrations were less than 1.2% by volume.

  8. Gas heating dynamics during leader inception in long air gaps at atmospheric pressure

    Science.gov (United States)

    Liu, Lipeng; Becerra, Marley

    2017-08-01

    The inception of leader discharges in long air gaps at atmospheric pressure is simulated with a thermo-hydrodynamic model and a detailed kinetic scheme for N2/O2/H2O mixtures. In order to investigate the effect of humidity, the kinetic scheme includes the most important reactions with the H2O molecule and its derivatives, resulting in a scheme with 45 species and 192 chemical reactions. The heating of a thin plasma channel in front of an anode electrode during the streamer to leader transition is evaluated with a detailed 1D radial model. The analysis includes the simulation of the corresponding streamer bursts, dark periods and aborted leaders that may occur prior to the inception of a propagating leader discharge. The simulations are performed using the time-varying discharge current in two laboratory discharge events of positive polarity reported in the literature as input. Excellent agreement between the simulated and the experimental time variation of the thermal radius for a 1 m rod-plate air gap discharge event reported in the literature has been found. The role of different energy transfer and loss mechanisms prior to the inception of a stable leader is also discussed. It is found that although a small percentage of water molecules can accelerate the vibrational-translational relaxation to some extent, this effect leads to a negligible temperature increase during the streamer-to-leader transition. It is also found that the gas temperature should significantly exceed 2000 K for the transition to lead to the inception of a propagating leader. Otherwise, the strong convection loss produced by the gas expansion during the transition causes a drop in the translational temperature below 2000 K, aborting the incepted leader. Furthermore, it is shown that the assumptions used by the widely-used model of Gallimberti do not hold when evaluating the streamer-to-leader transition.

  9. Electric field determination in streamer discharges in air at atmospheric pressure

    International Nuclear Information System (INIS)

    Bonaventura, Z; Bourdon, A; Celestin, S; Pasko, V P

    2011-01-01

    The electric field in streamer discharges in air can be easily determined by the ratio of luminous intensities emitted by N 2 (C 3 Π u ) and N 2 + (B 2 Σ u + ) if the steady-state assumption of the emitting states is fully justified. At ground pressure, the steady-state condition is not fulfilled and it is demonstrated that its direct use to determine the local and instantaneous peak electric field in the streamer head may overestimate this field by a factor of 2. However, when spatial and time-integrated optical emissions (OEs) are considered, the reported results show that it is possible to formulate a correction factor in the framework of the steady-state approximation and to accurately determine the peak electric field in an air discharge at atmospheric pressure. A correction factor is defined as Γ = E s /E e , where E e is the estimated electric field and E s is the true peak electric field in the streamer head. It is shown that this correction stems from (i) the shift between the location of the peak electric field and the maximum excitation rate for N 2 (C 3 Π u ) and N 2 + (B 2 Σ u + ) as proposed by Naidis (2009 Phys. Rev. E 79 057401) and (ii) from the cylindrical geometry of the streamers as stated by Celestin and Pasko (2010 Geophys. Res. Lett. 37 L07804). For instantaneous OEs integrated over the whole radiating plasma volume, a correction factor of Γ ∼ 1.4 has to be used. For time-integrated OEs, the reported results show that the ratio of intensities can be used to derive the electric field in discharges if the time of integration is sufficiently long (i.e. at least longer than the longest characteristic lifetime of excited species) to have the time to collect all the light from the emitting zones of the streamer. For OEs recorded using slits (i.e. a window with a small width but a sufficiently large radial extension to contain the total radial extension of the discharge) the calculated correction factor is Γ ∼ 1.4. As for OEs observed

  10. Study of heat transfer and pressure drop characteristics of air heat exchanger using PCM for free cooling applications

    Directory of Open Access Journals (Sweden)

    Kalaiselvam Sivakumar

    2016-01-01

    Full Text Available Free cooling is the process of storing the cool energy available in the night ambient air and using it during the day. The heat exchanger used in this work is a modular type which is similar to the shell and tube heat exchanger. The shell side is filled with Phase Change Materials (PCM and air flow is through the tubes in the module. The modules of the heat exchanger are arranged one over other with air spacers in between each module. The air space provided in between the module in-creases the retention time of the air for better heat transfer. Transient Computational Fluid Dynamics modeling is carried out for single air passage in a modular heat exchanger. It shows that the PCM phase transition time in the module in which different shape of fins is adopted. The module with rectangular fins has 17.2 % reduction in solidification compared with the plain module. Then steady state numerical analysis is accomplished to the whole module having the fin of high heat transfer, so that pressure drop, flow and thermal characteristics across the module and the air spacers are deter-mined for various air inlet velocities of 0.4 to 1.6 m/s. To validate the computational results, experiments are carried out and the agreement was found to be good.

  11. Pressure Relief, Visco-Elastic Foam with Inflated Air? A Pilot Study in a Dutch Nursing Home.

    Science.gov (United States)

    Van Leen, Martin; Schols, Jos

    2015-02-12

    There is still little evidence regarding the type of mattress that is the best for preventing pressure ulcers (PUs). In a Dutch nursing home, a new type of overlay mattress (air inflated visco-elastic foam) was tested to analyze the opportunity for replacement of the normally used static air overlay mattress in its three-step PU prevention protocol In this small pilot the outcome measures were: healing of a category one pressure ulcer, new development or deterioration of a category one PU and need for repositioning. We included 20 nursing home residents with a new category one pressure ulcer, existing for no longer than 48 h following a consecutive sampling technic. All residents were staying for more than 30 days in the nursing home and were lying on a visco-elastic foam mattress without repositioning (step one of the 3-step protocol) at the start of the pilot study. They had not suffered from a PU in the month before. The intervention involved use of an air inflated foam overlay instead of a static air overlay (normally step 2 of the 3-step protocol). At the start; the following data were registered: age; gender; main diagnosis and presence of incontinence. Thereafter; all participating residents were checked weekly for PU healing tendency; deterioration of PUs; new PUs and need of repositioning. Only when residents showed still a category one PU after 48 h or deterioration of an existing pressure ulcer or if there was development of a new pressure ulcer, repositioning was put into practice (step 3 of the PU protocol). All residents participated during 8 weeks. Seven residents developed a new pressure ulcer category one and still had a category one pressure ulcer at the end of the study period. One resident developed a pressure ulcer category 2. Fifteen residents needed repositioning from one week after start of the study until the end of the study. Overall 40% of the residents developed a pressure ulcer. Seventy five percent of the residents started with

  12. Pressure Relief, Visco-Elastic Foam with Inflated Air? A Pilot Study in a Dutch Nursing Home

    Directory of Open Access Journals (Sweden)

    Martin Van Leen

    2015-02-01

    Full Text Available Objective: There is still little evidence regarding the type of mattress that is the best for preventing pressure ulcers (PUs. In a Dutch nursing home, a new type of overlay mattress (air inflated visco-elastic foam was tested to analyze the opportunity for replacement of the normally used static air overlay mattress in its three-step PU prevention protocol In this small pilot the outcome measures were: healing of a category one pressure ulcer, new development or deterioration of a category one PU and need for repositioning. Methods: We included 20 nursing home residents with a new category one pressure ulcer, existing for no longer than 48 h following a consecutive sampling technic. All residents were staying for more than 30 days in the nursing home and were lying on a visco-elastic foam mattress without repositioning (step one of the 3-step protocol at the start of the pilot study. They had not suffered from a PU in the month before. The intervention involved use of an air inflated foam overlay instead of a static air overlay (normally step 2 of the 3-step protocol. At the start; the following data were registered: age; gender; main diagnosis and presence of incontinence. Thereafter; all participating residents were checked weekly for PU healing tendency; deterioration of PUs; new PUs and need of repositioning. Only when residents showed still a category one PU after 48 h or deterioration of an existing pressure ulcer or if there was development of a new pressure ulcer, repositioning was put into practice (step 3 of the PU protocol. All residents participated during 8 weeks. Results: Seven residents developed a new pressure ulcer category one and still had a category one pressure ulcer at the end of the study period. One resident developed a pressure ulcer category 2. Fifteen residents needed repositioning from one week after start of the study until the end of the study. Conclusions: Overall 40% of the residents developed a pressure ulcer

  13. Nanosecond Repetitively Pulsed Discharges in Air at Atmospheric Pressure -- Experiment and Theory of Regime Transitions

    Science.gov (United States)

    Pai, David; Lacoste, Deanna; Laux, Christophe

    2009-10-01

    In atmospheric pressure air preheated from 300 to 1000 K, the Nanosecond Repetitively Pulsed (NRP) method has been used to generate corona, glow, and spark discharges. Experiments have been performed to determine the parameter space (applied voltage, pulse repetition frequency, ambient gas temperature, and inter-electrode gap distance) of each discharge regime. Notably, there is a minimum gap distance for the existence of the glow regime that increases with decreasing gas temperature. A theory is developed to describe the Corona-to-Glow (C-G) and Glow-to-Spark (G-S) transitions for NRP discharges. The C-G transition is shown to depend on the Avalanche-to-Streamer Transition (AST) as well as the electric field strength in the positive column. The G-S transition is due to the thermal ionization instability. The minimum gap distance for the existence of the glow regime can be understood by considering that the applied voltage of the AST must be lower than that of the thermal ionization instability. This is a previously unknown criterion for generating glow discharges, as it does not correspond to the Paschen minimum or to the Meek-Raether criterion.

  14. Atmospheric pressure He-air plasma jet: Breakdown process and propagation phenomenon

    International Nuclear Information System (INIS)

    Begum, Asma; Laroussi, Mounir; Pervez, Mohammad Rasel

    2013-01-01

    In this paper He-discharge (plasma jet/bullet) in atmospheric pressure air and its progression phenomenon has been studied experimentally using ICCD camera, optical emission spectroscopy (OES) and calibrated dielectric probe measurements. The repetitive nanosecond pulse has applied to a plasma pencil to generate discharge in the helium gas channel. The discharge propagation speed was measured from the ICCD images. The axial electric field distribution in the plasma jet is inferred from the optical emission spectroscopic data and from the probe measurement. The correlation between the jet velocities, jet length with the pulse duration is established. It shows that the plasma jet is not isolated from the input voltage along its propagation path. The discharge propagation speed, the electron density and the local and average electric field distribution along the plasma jet axis predicted from the experimental results are in good agreement with the data predicted by numerical simulation of the streamer propagation presented in different literatures. The ionization phenomenon of the discharge predicts the key ionization parameters, such as speed, peak electric field in the front, and electron density. The maximum local electric field measured by OES is 95 kV/cm at 1.3 cm of the jet axis, and average EF measured by probe is 24 kV/cm at the same place of the jet. The average and local electron density estimated are in the order of 10 11 cm -3 and it reaches to the maximum of 10 12 cm -3 .

  15. Modification of polypropylene in the afterglow of the atmospheric pressure discharges in air and argon

    Science.gov (United States)

    Vasilkin, D. P.; Shikova, T. G.; Titov, V. A.; Smirnov, S. A.; Khomyakova, N. S.

    2017-11-01

    Polypropylene films were modified in the flowing afterglow of the atmospheric pressure DC discharge in argon and in air. The modification was carried out at a discharge current of 15 mA, a gas flow rate of 24 and 105 m/s and a treatment time of 3 - 30 s. Polymer samples were placed on the distance of 5 - 15 mm downstream the plasma Contact angles for water and ATR-FTIR spectra were used for the film surface characterization. Concentrations of oxygen containing groups in modified polymer layer were estimated on the base of ATR-FTIR data. Modification in the both plasma forming gases results in the decrease of the contact angles and in the formation of oxygen containing groups in the polymer surface layer. Dependencies of contact angles on treatment time, gas flow rate and plasma - polymer distance were obtained. Increasing the treatment time and the gas flow rate results in a higher oxidation degree of the PP. Treatment in the afterglow of the argon plasma has been shown to give the less water contact angles and more densities of oxygen containing groups in polypropilene at the gas flow rate of 105 m/s and the treatment time of 30 s.

  16. Auto-ignition of lubricating oil working at high pressures in a compressor for an air conditioner.

    Science.gov (United States)

    Kim, Chul Jin; Choi, Hyo Hyun; Sohn, Chae Hoon

    2011-01-15

    Auto-ignition of lubricating oil working in a compressor for an air conditioner is studied experimentally. The adopted lubricating oil is an unknown mixture with multi-components and known to have flash point temperature of 170 °C. First, its auto-ignition temperature is measured 365 °C at atmospheric pressure. The lubricating oil works under high-pressure condition up to 30 atm and it is heated and cooled down repeatedly. Accordingly, auto-ignition temperatures or flammable limits of lubricating oil are required at high pressures with respect to fire safety. Because there is not a standard test method for the purpose, a new ignition-test method is proposed in this study and thereby, auto-ignition temperatures are measured over the pressure range below 30 atm. The measured temperatures range from 215 °C to 255 °C and they strongly depend on pressure of gas mixture consisting of oil vapor, nitrogen, and oxygen. They are close to flash point temperature and the lubricating oil can be hazardous when it works for high-pressure operating condition and abundant air flows into a compressor. Copyright © 2010 Elsevier B.V. All rights reserved.

  17. Auto-ignition of lubricating oil working at high pressures in a compressor for an air conditioner

    International Nuclear Information System (INIS)

    Kim, Chul Jin; Choi, Hyo Hyun; Sohn, Chae Hoon

    2011-01-01

    Auto-ignition of lubricating oil working in a compressor for an air conditioner is studied experimentally. The adopted lubricating oil is an unknown mixture with multi-components and known to have flash point temperature of 170 deg. C. First, its auto-ignition temperature is measured 365 deg. C at atmospheric pressure. The lubricating oil works under high-pressure condition up to 30 atm and it is heated and cooled down repeatedly. Accordingly, auto-ignition temperatures or flammable limits of lubricating oil are required at high pressures with respect to fire safety. Because there is not a standard test method for the purpose, a new ignition-test method is proposed in this study and thereby, auto-ignition temperatures are measured over the pressure range below 30 atm. The measured temperatures range from 215 deg. C to 255 deg. C and they strongly depend on pressure of gas mixture consisting of oil vapor, nitrogen, and oxygen. They are close to flash point temperature and the lubricating oil can be hazardous when it works for high-pressure operating condition and abundant air flows into a compressor.

  18. RESIDUAL RISK ASSESSMENTS - RESIDUAL RISK ...

    Science.gov (United States)

    This source category previously subjected to a technology-based standard will be examined to determine if health or ecological risks are significant enough to warrant further regulation for Coke Ovens. These assesments utilize existing models and data bases to examine the multi-media and multi-pollutant impacts of air toxics emissions on human health and the environment. Details on the assessment process and methodologies can be found in EPA's Residual Risk Report to Congress issued in March of 1999 (see web site). To assess the health risks imposed by air toxics emissions from Coke Ovens to determine if control technology standards previously established are adequately protecting public health.

  19. Gasificación con aire en lecho fluidizado de los residuos sólidos del proceso industrial de la naranja//Air gasification in fluidized bed of solid residue the orange industrial process

    Directory of Open Access Journals (Sweden)

    Leonardo Aguiar-Trujillo

    2012-12-01

    Full Text Available La industria procesadora de la naranja genera elevados volúmenes de residuos sólidos. Este residuo se ha utilizado en la alimentación animal y en procesos bioquímicos; pero no se ha aprovechado a través de la gasificación. El objetivo del trabajo fue determinar el aporte energético por medio del proceso de gasificación, realizándose estudios de los residuos sólidos de naranja, utilizando aire en reactor de lecho fluidizado burbujeante (variando la temperatura de gasificación, relación estequiométrica y altura del lecho. En el proceso se utilizó un diseño de experimento factorial completo de 2k, valorando la influencia de las variables independientes y sus interacciones en las respuestas, con un grado de significación del 95 %. Se obtuvieron los parámetros para efectuar el proceso de gasificación de los residuos sólidos de naranja, obteniendo un gas de bajo poder calórico, próximo a 5046 kJ/m3N, demostrando sus cualidades para su aprovechamiento energético.Palabras claves: gasificación con aire, lecho fluidizado, residuo de naranja._______________________________________________________________________________AbstractThe orange industrial process generates high volumes of solid residue. This residue has been used as complement in the animal feeding and biochemical processes; but it has not taken advantage through of the gasification process. The objective of the work was to determine the energy contribution by means ofthe gasification process, were carried out studies of the orange solid residue, using air in reactor of bubbling fluidized bed (varying the gasification temperature, air ratio and bed height. In the process a design of complete factorial experiment of 2k, was used, valuing the influence of the independent variables and its interactions in the answers, using a confidence level of 95 %. Were obtained the parameters to make the process of gasification of the orange solid residue, obtaining a gas of lower heating

  20. Correlation of surface pressure and hue of planarizable push–pull chromophores at the air/water interface

    Directory of Open Access Journals (Sweden)

    Frederik Neuhaus

    2017-06-01

    Full Text Available It is currently not possible to directly measure the lateral pressure of a biomembrane. Mechanoresponsive fluorescent probes are an elegant solution to this problem but it requires first the establishment of a direct correlation between the membrane surface pressure and the induced color change of the probe. Here, we analyze planarizable dithienothiophene push–pull probes in a monolayer at the air/water interface using fluorescence microscopy, grazing-incidence angle X-ray diffraction, and infrared reflection–absorption spectroscopy. An increase of the lateral membrane pressure leads to a well-packed layer of the ‘flipper’ mechanophores and a clear change in hue above 18 mN/m. The fluorescent probes had no influence on the measured isotherm of the natural phospholipid DPPC suggesting that the flippers probe the lateral membrane pressure without physically changing it. This makes the flipper probes a truly useful addition to the membrane probe toolbox.

  1. Measurement of Atmospheric Pressure Air Plasma via Pulsed Electron Beam and Sustaining Electric Field

    National Research Council Canada - National Science Library

    Vidmar, Robert J; Stalder, Kenneth R

    2007-01-01

    .... A particle in cell plasma code (MAGIC) and an air-chemistry code are used to quantify beam propagation through an electron-beam transmission window into air and the volumetric ionization rate within the test cell...

  2. Effect of Soret diffusion on lean hydrogen/air flames at normal and elevated pressure and temperature

    KAUST Repository

    Zhou, Zhen

    2017-04-12

    The influence of Soret diffusion on lean premixed flames propagating in hydrogen/air mixtures is numerically investigated with a detailed chemical and transport models at normal and elevated pressure and temperature. The Soret diffusion influence on the one-dimensional (1D) flame mass burning rate and two-dimensional (2D) flame propagating characteristics is analysed, revealing a strong dependency on flame stretch rate, pressure and temperature. For 1D flames, at normal pressure and temperature, with an increase of Karlovitz number from 0 to 0.4, the mass burning rate is first reduced and then enhanced by Soret diffusion of H2 while it is reduced by Soret diffusion of H. The influence of Soret diffusion of H2 is enhanced by pressure and reduced by temperature. On the contrary, the influence of Soret diffusion of H is reduced by pressure and enhanced by temperature. For 2D flames, at normal pressure and temperature, during the early phase of flame evolution, flames with Soret diffusion display more curved flame cells. Pressure enhances this effect, while temperature reduces it. The influence of Soret diffusion of H2 on the global consumption speed is enhanced at elevated pressure. The influence of Soret diffusion of H on the global consumption speed is enhanced at elevated temperature. The flame evolution is more affected by Soret diffusion in the early phase of propagation than in the long run due to the local enrichment of H2 caused by flame curvature effects. The present study provides new insights into the Soret diffusion effect on the characteristics of lean hydrogen/air flames at conditions that are relevant to practical applications, e.g. gas engines and turbines.

  3. Residual stress and its effect on the mechanical properties of Y-doped Mg alloy fabricated via back-pressure assisted equal channel angular pressing (ECAP-BP)

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Jianghua, E-mail: j_shen@live.cn [Department of Mechanical Engineering, University of North Carolina at Charlotte, Charlotte, NC 28223-0001 (United States); School of Aeronautics, Northwestern Polytechnical University, Xi’an 710072 (China); Gärtnerová, Viera [Laboratory of Nanostructures and Nanomaterials, Institute of Physics of the ASCR, Na Slovance 2, CZ – 182 21, Prague 8 (Czech Republic); Kecskes, Laszlo J. [US Army Research Laboratory, Aberdeen Proving Ground, MD 21005-5069 (United States); Kondoh, Katsuyoshi [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaragi, Osaka 567-0047 (Japan); Jäger, Aleš, E-mail: jager@fzu.cz [Laboratory of Nanostructures and Nanomaterials, Institute of Physics of the ASCR, Na Slovance 2, CZ – 182 21, Prague 8 (Czech Republic); Wei, Qiuming [Department of Mechanical Engineering, University of North Carolina at Charlotte, Charlotte, NC 28223-0001 (United States)

    2016-07-04

    In this study, pure magnesium (Mg) and Mg-0.6 wt% yttrium (Y) binary alloy were fabricated via casting followed by room temperature equal channel angular pressing (ECAP) using an applied back pressure (BP). Microstructural examination after ECAP-BP revealed a fine-grained Mg-Y alloy with a high residual stress level, whereas, the pure Mg exhibited a well-recrystallized microstructure with uniform and equiaxed grains, but retaining very little residual stress. The Y atoms were present in the Mg matrix as solid solutes and acted as dislocation and grain boundary blockers, thus suppressing dynamic recovery and/or recrystallization during the ECAP process. The Mg-Y alloy had an average grain size of ~400 nm, approximately one order smaller than that of pure Mg. The combination of high residual stress and ultrafine grains of the Mg-Y alloy gave rise to a significant difference in its mechanical behavior from that of the pure Mg, under both quasi-static and dynamic compressive loading.

  4. Nanosecond repetitively pulsed discharges in air at atmospheric pressure-the spark regime

    International Nuclear Information System (INIS)

    Pai, David Z; Lacoste, Deanna A; Laux, Christophe O

    2010-01-01

    Nanosecond repetitively pulsed (NRP) spark discharges have been studied in atmospheric pressure air preheated to 1000 K. Measurements of spark initiation and stability, plasma dynamics, gas temperature and current-voltage characteristics of the spark regime are presented. Using 10 ns pulses applied repetitively at 30 kHz, we find that 2-400 pulses are required to initiate the spark, depending on the applied voltage. Furthermore, about 30-50 pulses are required for the spark discharge to reach steady state, following initiation. Based on space- and time-resolved optical emission spectroscopy, the spark discharge in steady state is found to ignite homogeneously in the discharge gap, without evidence of an initial streamer. Using measured emission from the N 2 (C-B) 0-0 band, it is found that the gas temperature rises by several thousand Kelvin in the span of about 30 ns following the application of the high-voltage pulse. Current-voltage measurements show that up to 20-40 A of conduction current is generated, which corresponds to an electron number density of up to 10 15 cm -3 towards the end of the high-voltage pulse. The discharge dynamics, gas temperature and electron number density are consistent with a streamer-less spark that develops homogeneously through avalanche ionization in volume. This occurs because the pre-ionization electron number density of about 10 11 cm -3 produced by the high frequency train of pulses is above the critical density for streamer-less discharge development, which is shown to be about 10 8 cm -3 .

  5. Inhibitory effect of silver nanoparticles mediated by atmospheric pressure air cold plasma jet against dermatophyte fungi.

    Science.gov (United States)

    Ouf, Salama A; El-Adly, Amira A; Mohamed, Abdel-Aleam H

    2015-10-01

    In an in vitro study with five clinical isolates of dermatophytes, the MIC(50) and MIC(100) values of silver nanoparticles (AgNPs) ranged from 5 to 16 and from 15 to 32 μg ml(- 1), respectively. The combined treatment of AgNPs with atmospheric pressure-air cold plasma (APACP) induced a drop in the MIC(50) and MIC100 values of AgNPs reaching 3-11 and 12-23 μg ml(- 1), respectively, according to the examined species. Epidermophyton floccosum was the most sensitive fungus to AgNPs, while Trichophyton rubrum was the most tolerant. AgNPs induced significant reduction in keratinase activity and an increase in the mycelium permeability that was greater when applied combined with plasma treatment. Scanning electron microscopy showed electroporation of the cell walls and the accumulation of AgNPs on the cell wall and inside the cells, particularly when AgNPs were combined with APACP treatment. An in vivo experiment with dermatophyte-inoculated guinea pigs indicated that the application of AgNPs combined with APACP was more efficacious in healing and suppressing disease symptoms of skin as compared with the application of AgNPs alone. The recovery from the infection reached 91.7 % in the case of Microsporum canis-inoculated guinea pigs treated with 13 μg ml(- 1) AgNPs combined with APACP treatment delivered for 2  min. The emission spectra indicated that the efficacy of APACP was mainly due to generation of NO radicals and excited nitrogen molecules. These reactive species interact and block the activity of the fungal spores in vitro and in the skin lesions of the guinea pigs. The results achieved are promising compared with fluconazole as reference antifungal drug.

  6. Atmospheric pressure He-air plasma jet: Breakdown process and propagation phenomenon

    Energy Technology Data Exchange (ETDEWEB)

    Begum, Asma [Independent University, Bangladesh, School of Engineering and Computer Science, Bashundhara, Dhaka (Bangladesh); Laroussi, Mounir [Old Dominion University, Department of Electrical and Computer Engineering, Norfolk, Virginia (United States); Pervez, Mohammad Rasel [Master Mind College, Department of Physics, Dhanmondi, Dhaka (Bangladesh)

    2013-06-15

    In this paper He-discharge (plasma jet/bullet) in atmospheric pressure air and its progression phenomenon has been studied experimentally using ICCD camera, optical emission spectroscopy (OES) and calibrated dielectric probe measurements. The repetitive nanosecond pulse has applied to a plasma pencil to generate discharge in the helium gas channel. The discharge propagation speed was measured from the ICCD images. The axial electric field distribution in the plasma jet is inferred from the optical emission spectroscopic data and from the probe measurement. The correlation between the jet velocities, jet length with the pulse duration is established. It shows that the plasma jet is not isolated from the input voltage along its propagation path. The discharge propagation speed, the electron density and the local and average electric field distribution along the plasma jet axis predicted from the experimental results are in good agreement with the data predicted by numerical simulation of the streamer propagation presented in different literatures. The ionization phenomenon of the discharge predicts the key ionization parameters, such as speed, peak electric field in the front, and electron density. The maximum local electric field measured by OES is 95 kV/cm at 1.3 cm of the jet axis, and average EF measured by probe is 24 kV/cm at the same place of the jet. The average and local electron density estimated are in the order of 10{sup 11} cm{sup -3} and it reaches to the maximum of 10{sup 12} cm{sup -3}.

  7. Spatiotemporally resolved characteristics of a gliding arc discharge in a turbulent air flow at atmospheric pressure

    Science.gov (United States)

    Zhu, Jiajian; Gao, Jinlong; Ehn, Andreas; Aldén, Marcus; Larsson, Anders; Kusano, Yukihiro; Li, Zhongshan

    2017-01-01

    A gliding arc discharge was generated in a turbulent air flow at atmospheric pressure driven by a 35 kHz alternating current (AC) electric power. The spatiotemporally resolved characteristics of the gliding arc discharge, including glow-type discharges, spark-type discharges, short-cutting events and transitions among the different types of discharges, were investigated using simultaneously optical and electrical diagnostics. The glow-type discharge shows sinusoidal-like voltage and current waveforms with a peak current of hundreds of milliamperes. The frequency of the emission intensity variation of the glow-type discharge is the same as that of the electronic power dissipated in the plasma column. The glow-type discharge can transfer into a spark discharge characterized by a sharp peak current of several amperes and a sudden increase of the brightness in the plasma column. Transitions can also be found to take place from spark-type discharges to glow-type discharges. Short-cutting events were often observed as the intermediate states formed during the spark-glow transition. Three different types of short-cutting events have been observed to generate new current paths between two plasma channel segments, and between two electrodes, as well as between the channel segment and the electrodes, respectively. The short-cut upper part of the plasma column that was found to have no current passing through can be detected several hundreds of microseconds after the short-cutting event. The voltage recovery rate, the period of AC voltage-driving signal, the flow rates and the rated input powers were found to play an important role in affecting the transitions among the different types of discharges.

  8. Long-term urban particulate air pollution, traffic noise, and arterial blood pressure.

    Science.gov (United States)

    Fuks, Kateryna; Moebus, Susanne; Hertel, Sabine; Viehmann, Anja; Nonnemacher, Michael; Dragano, Nico; Möhlenkamp, Stefan; Jakobs, Hermann; Kessler, Christoph; Erbel, Raimund; Hoffmann, Barbara

    2011-12-01

    Recent studies have shown an association of short-term exposure to fine particulate matter (PM) with transient increases in blood pressure (BP), but it is unclear whether long-term exposure has an effect on arterial BP and hypertension. We investigated the cross-sectional association of residential long-term PM exposure with arterial BP and hypertension, taking short-term variations of PM and long-term road traffic noise exposure into account. We used baseline data (2000-2003) on 4,291 participants, 45-75 years of age, from the Heinz Nixdorf Recall Study, a population-based prospective cohort in Germany. Urban background exposure to PM with aerodynamic diameter ≤ 2.5 μm (PM(2.5)) and ≤ 10 μm (PM(10)) was assessed with a dispersion and chemistry transport model. We used generalized additive models, adjusting for short-term PM, meteorology, traffic proximity, and individual risk factors. An interquartile increase in PM2.5 (2.4 μg/m(3)) was associated with estimated increases in mean systolic and diastolic BP of 1.4 mmHg [95% confidence interval (CI): 0.5, 2.3] and 0.9 mmHg (95% CI: 0.4, 1.4), respectively. The observed relationship was independent of long-term exposure to road traffic noise and robust to the inclusion of many potential confounders. Residential proximity to high traffic and traffic noise exposure showed a tendency toward higher BP and an elevated prevalence of hypertension. We found an association of long-term exposure to PM with increased arterial BP in a population-based sample. This finding supports our hypothesis that long-term PM exposure may promote atherosclerosis, with air-pollution-induced increases in BP being one possible biological pathway.

  9. Liquid Steel at Low Pressure: Experimental Investigation of a Downward Water Air Flow

    Science.gov (United States)

    Thumfart, Maria

    2016-07-01

    In the continuous casting of steel controlling the steel flow rate to the mould is critical because a well-defined flow field at the mould level is essential for a good quality of the cast product. The stopper rod is a commonly used device to control this flow rate. Agglomeration of solid material near the stopper rod can lead to a reduced cross section and thus to a decreased casting speed or even total blockage (“clogging”). The mechanisms causing clogging are still not fully understood. Single phase considerations of the flow in the region of the stopper rod result in a low or even negative pressure at the smallest cross section. This can cause degassing of dissolved gases from the melt, evaporation of alloys and entrainment of air through the porous refractory material. It can be shown that the degassing process in liquid steel is taking place mainly at the stopper rod tip and its surrounding. The steel flow around the stopper rod tip is highly turbulent. In addition refractory material has a low wettability to liquid steel. So the first step to understand the flow situation and transport phenomena which occur near the stopper is to understand the behaviour of this two phase (steel, gas) flow. To simulate the flow situation near the stopper rod tip, water experiments are conducted using a convergent divergent nozzle with three different wall materials and three different contact angles respectively. These experiments show the high impact of the wettability of the wall material on the actual flow structure at a constant gas flow rate.

  10. Effect of pressure on the lean limit flames of H2-CH4-air mixture in tubes

    KAUST Repository

    Zhou, Zhen

    2017-05-25

    The lean limit flames of H2-CH4-air mixtures stabilized inside tubes in a downward flow are experimentally and numerically investigated at elevated pressures ranging from 2 to 5 bar. For the shapes of lean limit flames, a change from ball-like flame to cap-like flame is experimentally observed with the increase of pressure. This experimentally observed phenomenon is qualitatively predicted by numerical simulations. The structure of ball-like and cap-like lean limit flames at all tested pressures is analysed in detail based on the numerical predictions. The results show that the lean limit flames are located inside a recirculation zone at all tested pressures. For the leading edges of the lean limit flames at all tested pressures, the fuel transport is controlled by both convection and diffusion. For the trailing edge of the ball-like lean limit flame at 2 bar, the fuel transport is dominated by diffusion. However, with increasing pressure, the transport contribution caused by convection in the trailing edges of the lean limit flames increases. Finally, the influence of transport and chemistry on the predicted ultra lean flames and lean flammability limit is analysed at elevated pressures.

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

    Science.gov (United States)

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

    2015-08-01

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

  12. The effect of low-NOx combustion on residual carbon in fly ash and its adsorption capacity for air entrainment admixtures in concrete

    DEFF Research Database (Denmark)

    Pedersen, Kim Hougaard; Jensen, Anker Degn; Dam-Johansen, Kim

    2010-01-01

    Fly ash from pulverized coal combustion contains residual carbon that can adsorb the air-entraining admixtures (AEAs) added to control the air entrainment in concrete. This is a problem that has increased by the implementation of low-NOx combustion technologies. In this work, pulverized fuel has...... by up to a factor of 25. This was due to a lower carbon content in the ash and a lower specific AEA adsorptivity of the carbon. The latter was suggested to be caused by changes in the adsorption properties of the unburned char and a decreased formation of soot, which was found to have a large AEA...... adsorption capacity based on measurements on a carbon black. The NOx formation increased by up to three times with more oxidizing conditions and thus, there was a trade-off between the AEA requirements of the ash and NOx formation. The type of fuel had high impact on the AEA adsorption behavior of the ash...

  13. Long-term ambient air pollution exposure and risk of high blood pressure among citizens in Nis, Serbia.

    Science.gov (United States)

    Stanković, Aleksandra; Nikolić, Maja

    2016-01-01

    Epidemiological studies suggest that long-term exposure to air pollution increases the risk for high blood pressure (BP). The aim of our study is to evaluate any effects in BP in citizens exposed to long-term ambient air pollution. The subjects are 1136 citizens, aged 18-70 years, living for more than 5 years in the same home in the areas with a different level of air pollution. The air concentrations of black smoke and sulfur dioxide were determined in the period from 2001 to 2011. We measured systolic and diastolic BP and heart rate. Multivariate methods were used in the analysis. Alcohol consumption had the greatest influence on the incidence of hypertension as a risk factor (RR: 3.461; 95% CI: 1.72-6.93) and age had the least (RR: 1.23; 95% CI: 1.183-1.92). Exposure to air pollution increases risk for developing hypertension 2.5 times (95% CI: 1.46-4.49). Physical activity has proved to be statistically significant protective factor for the development of hypertension. Long-term exposure to low levels of main air pollutants is significantly associated with elevated risk of hypertension.

  14. Transitions between corona, glow, and spark regimes of nanosecond repetitively pulsed discharges in air at atmospheric pressure

    OpenAIRE

    Pai , David ,; Lacoste , Deanna ,; Laux , C.

    2010-01-01

    International audience; In atmospheric pressure air preheated from 300 to 1000 K, the nanosecond repetitively pulsed (NRP) method has been used to generate corona, glow, and spark discharges. Experiments have been performed to determine the parameter space (applied voltage, pulse repetition frequency, ambient gas temperature, and interelectrode gap distance) of each discharge regime. In particular, the experimental conditions necessary for the glow regime of NRP discharges have been determine...

  15. Minesweeping for Pressure Actuated Mines by Air Injection into a Water Column

    Science.gov (United States)

    2011-09-01

    13 Figure 6. Manometer (left) and pressure sensor (right) ..................................... 14 Figure 7. Bubble...original equipment is shown in Figure 6. Figure 6. Manometer (left) and pressure sensor (right) Initial data was taken using a digital... manometer in a tank at the Templeman Automation home office. Results from this testing showed a definitive 0.1 inch pressure drop for a 6-inch bubble

  16. The role of residual blood pressure in antihypertensive effects of captopril treatment in young and adult spontaneously hypertensive rats

    Czech Academy of Sciences Publication Activity Database

    Kuneš, Jaroslav; Dobešová, Zdenka; Zicha, Josef

    2006-01-01

    Roč. 24, č. S4 (2006), S343-S344 ISSN 0263-6352. [European Meeting on Hypertension /16./. 12.06.2006-15.06.2006, Madrid] R&D Projects: GA MZd(CZ) NR7786 Keywords : blood pressure * captopril * hypertension Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

  17. Quantification of pressure sensitive adhesive, residual ink, and other colored process contaminants using dye and color image analysis

    Science.gov (United States)

    Roy R. Rosenberger; Carl J. Houtman

    2000-01-01

    The USPS Image Analysis (IA) protocol recommends the use of hydrophobic dyes to develop contrast between pressure sensitive adhesive (PSA) particles and cellulosic fibers before using a dirt counter to detect all contaminants that have contrast with the handsheet background. Unless the sample contains no contaminants other than those of interest, two measurement steps...

  18. Human activity under high pressure: A case study on fluctuation scaling of air traffic controller's communication behaviors

    Science.gov (United States)

    Wang, Yanjun; Zhang, Qiqian; Zhu, Chenping; Hu, Minghua; Duong, Vu

    2016-01-01

    Recent human dynamics research has unmasked astonishing statistical characteristics such as scaling behaviors in human daily activities. However, less is known about the general mechanism that governs the task-specific activities. In particular, whether scaling law exists in human activities under high pressure remains an open question. In air traffic management system, safety is the most important factor to be concerned by air traffic controllers who always work under high pressure, which provides a unique platform to study human activity. Here we extend fluctuation scaling method to study air traffic controller's communication activity by investigating two empirical communication datasets. Taken the number of controlled flights as the size-like parameter, we show that the relationships between the average communication activity and its standard deviation in both datasets can be well described by Taylor's power law, with scaling exponent α ≈ 0.77 ± 0.01 for the real operational data and α ≈ 0.54 ± 0.01 for the real-time training data. The difference between the exponents suggests that human dynamics under pressure is more likely dominated by the exogenous force. Our findings may lead to further understanding of human behavior.

  19. Earth's air pressure 2.7 billion years ago constrained to less than half of modern levels

    Science.gov (United States)

    Som, Sanjoy M.; Buick, Roger; Hagadorn, James W.; Blake, Tim S.; Perreault, John M.; Harnmeijer, Jelte P.; Catling, David C.

    2016-06-01

    How the Earth stayed warm several billion years ago when the Sun was considerably fainter is the long-standing problem of the `faint young Sun paradox'. Because of negligible O2 and only moderate CO2 levels in the Archaean atmosphere, methane has been invoked as an auxiliary greenhouse gas. Alternatively, pressure broadening in a thicker atmosphere with a N2 partial pressure around 1.6-2.4 bar could have enhanced the greenhouse effect. But fossilized raindrop imprints indicate that air pressure 2.7 billion years ago (Gyr) was below twice modern levels and probably below 1.1 bar, precluding such pressure enhancement. This result is supported by nitrogen and argon isotope studies of fluid inclusions in 3.0-3.5 Gyr rocks. Here, we calculate absolute Archaean barometric pressure using the size distribution of gas bubbles in basaltic lava flows that solidified at sea level ~2.7 Gyr in the Pilbara Craton, Australia. Our data indicate a surprisingly low surface atmospheric pressure of Patm = 0.23 +/- 0.23 (2σ) bar, and combined with previous studies suggests ~0.5 bar as an upper limit to late Archaean Patm. The result implies that the thin atmosphere was rich in auxiliary greenhouse gases and that Patm fluctuated over geologic time to a previously unrecognized extent.

  20. An Analytical Explanation for the X-43A Flush Air Data Sensing System Pressure Mismatch Between Flight and Theory

    Science.gov (United States)

    Ellsworth, Joel C.

    2010-01-01

    Following the successful Mach 7 flight test of the X-43A, unexpectedly low pressures were measured by the aft set of the onboard Flush Air Data Sensing System s pressure ports. These in-flight aft port readings were significantly lower below Mach 3.5 than was predicted by theory. The same lower readings were also seen in the Mach 10 flight of the X-43A and in wind-tunnel data. The pre-flight predictions were developed based on 2-dimensional wedge flow, which fails to predict some of the significant 3-dimensional flow features in this geometry at lower Mach numbers. Using Volterra s solution to the wave equation as a starting point, a three-dimensional finite wedge approximation to flow over the X-43A forebody is presented. The surface pressures from this approximation compare favorably with the measured wind tunnel and flight data at speeds of Mach 2.5 and 3.

  1. Determination of octanol-air partition coefficients and supercooled liquid vapor pressures of organochlorine pesticides.

    Science.gov (United States)

    Zhang, Na; Yang, Yu; Liu, Yu; Tao, Shu

    2009-09-01

    Octanol-air partition coefficients (K(OA)) and supercooled liquid vapor pressures (P(L)) of nine organochlorine pesticides (OCPs) including p,p'-DDE, p,p'-DDD, o,p'-DDT, o,p'-DDE, o,p'-DDD, alpha-HCH, beta-HCH, gamma-HCH, delta-HCH were determined as functions of temperature using a gas chromatographic retention time method. Among them, the K(OA) of o,p'-DDE and o,p'-DDD and the P(L) of o,p'-DDE, o,p'-DDD, beta-HCH and delta-HCH were determined for the first time. The determined K(OA) and P(L) values of investigated compounds at 25 degrees C ranged from 3.14 x 10(7) (alpha-HCH) to 3.76 x 10(9) (p,p'-DDD), and 8.95 x 10(-4) Pa (p,p'-DDD) to 1.08 x 10(-1) Pa (alpha-HCH), respectively. The K(OA) and P(L) data were compared with published data. The K(OA) values of o,p'-DDT at 25 degrees C were 3.23 x 10(9), higher than o,p'-DDE (1.02 x 10(9)) and o,p'-DDD (2.01 x 10(9)), indicating o,p'-DDT were more preferred to partition in soil compared with the metabolites. The K(OA) values were lower and P(L) values were higher for o,p'-DDE and o,p'-DDD, compared with their p,p'-isomeric counterparts, leading to a potential difference in behavior and fate of these isomers. The discrepancies among chemicals are obvious, which reflected in the increasing K(OA) and decreasing P(L) values in order of alpha-HCH, gamma-HCH, beta-HCH, delta-HCH, o,p'-DDE, p,p'-DDE, o,p'-DDD, o,p'-DDT, p,p'-DDD. For each compound, the LogK(OA) decreased linearly with reciprocal absolute temperature, while LogP(L) had a significant positive correlation with the inverse absolute temperature. The present study suggested that the method of gas chromatographic retention time was appropriate to measure the K(OA) and P(L) of a number of OCPs.

  2. Ionic wind generation by a wire-cylinder-plate corona discharge in air at atmospheric pressure

    Science.gov (United States)

    Colas, Dorian F.; Ferret, Antoine; Pai, David Z.; Lacoste, Deanna A.; Laux, Christophe O.

    2010-11-01

    A wire-cylinder-plate electrode configuration is presented to generate ionic wind with a dc corona discharge in air at atmospheric pressure. The objective of the work is to maximize the power supplied to the flow in order to increase acceleration while avoiding breakdown. Thus, the proposed experimental setup addresses the problem of decoupling the mechanism of ion generation from that of ion acceleration. Using a wire-plate configuration as a reference, we have focused on improving the topography of the electric field to (1) separate the ionization and acceleration zones in space, and (2) guide the trajectory of charged particles as parallel to the median axis as possible. In the proposed wire-cylinder-plate setup, a dc corona discharge is generated in the space between a wire and two cylinders. The ions produced by the corona then drift past the cylinders and into a channel between two plates, where they undergo acceleration. To maximize the ionic wind it is found that the geometric configuration must be as compact as possible and that the voltage applied must be right below breakdown. Experimentally, the optimized wire-plate reference setup provides a maximum flow velocity of 8 m s-1, a flow rate per unit electrode length of 0.034 m2 s-1, and a thrust per unit electrode length of 0.24 N m-1. The wire-cylinder-plate configuration provides a maximum flow velocity of 10 m s-1, a flow rate per unit electrode length of 0.041 m2 s-1, and a thrust per unit electrode length of 0.35 N m-1. This 46% increase in thrust is obtained by increasing the electric power per unit electrode length by only 16% (from 175 to 210 W m-1), which confirms the gain in efficiency obtained with the decoupled system. In comparison with a simple wire-wire corona configuration, the wire-cylinder-plate configuration increases the ionic wind velocity by up to a factor of 3, and the thrust by an order of magnitude.

  3. On the Ground or in the Air? A Methodological Experiment on Crop Residue Cover Measurement in Ethiopia

    Science.gov (United States)

    Kosmowski, Frédéric; Stevenson, James; Campbell, Jeff; Ambel, Alemayehu; Haile Tsegay, Asmelash

    2017-10-01

    Maintaining permanent coverage of the soil using crop residues is an important and commonly recommended practice in conservation agriculture. Measuring this practice is an essential step in improving knowledge about the adoption and impact of conservation agriculture. Different data collection methods can be implemented to capture the field level crop residue coverage for a given plot, each with its own implication on survey budget, implementation speed and respondent and interviewer burden. In this paper, six alternative methods of crop residue coverage measurement are tested among the same sample of rural households in Ethiopia. The relative accuracy of these methods are compared against a benchmark, the line-transect method. The alternative methods compared against the benchmark include: (i) interviewee (respondent) estimation; (ii) enumerator estimation visiting the field; (iii) interviewee with visual-aid without visiting the field; (iv) enumerator with visual-aid visiting the field; (v) field picture collected with a drone and analyzed with image-processing methods and (vi) satellite picture of the field analyzed with remote sensing methods. Results of the methodological experiment show that survey-based methods tend to underestimate field residue cover. When quantitative data on cover are needed, the best estimates are provided by visual-aid protocols. For categorical analysis (i.e., >30% cover or not), visual-aid protocols and remote sensing methods perform equally well. Among survey-based methods, the strongest correlates of measurement errors are total farm size, field size, distance, and slope. Results deliver a ranking of measurement options that can inform survey practitioners and researchers.

  4. Comparison of two repositioning schedules for the prevention of pressure ulcers in patients on mechanical ventilation with alternating pressure air mattresses.

    Science.gov (United States)

    Manzano, Francisco; Colmenero, Manuel; Pérez-Pérez, Ana María; Roldán, Delphine; Jiménez-Quintana, María del Mar; Mañas, María Reyes; Sánchez-Moya, María Angustias; Guerrero, Carmen; Moral-Marfil, María Ángeles; Sánchez-Cantalejo, Emilio; Fernández-Mondéjar, Enrique

    2014-11-01

    The objective was to compare the effectiveness of repositioning every 2 or 4 h for preventing pressure ulcer development in patients in intensive care unit under mechanical ventilation (MV). This was a pragmatic, open-label randomized clinical trial in consecutive patients on an alternating pressure air mattress (APAM) requiring invasive MV for at least 24 h in a university hospital in Spain. Eligible participants were randomly assigned to groups for repositioning every 2 (n = 165) or 4 (n = 164) h. The primary outcome was the incidence of a pressure ulcer of at least grade II during ICU stay. A pressure ulcer of at least grade II developed in 10.3% (17/165) of patients turned every 2 h versus 13.4% (22/164) of those turned every 4 h (hazard ratio [HR] 0.89, 95% confidence interval [CI] 0.46-1.71, P = 0.73). The composite end point of device-related adverse events was recorded in 47.9 versus 36.6% (HR 1.50, CI 95% 1.06-2.11, P = 0.02), unplanned extubation in 11.5 versus 6.7% (HR 1.77, 95% CI 0.84-3.75, P = 0. 13), and endotracheal tube obstruction in 36.4 versus 30.5%, respectively (HR 1.44, 95% CI 0.98-2.12, P = 0.065). The median (interquartile range) daily nursing workload for manual repositioning was 21 (14-27) versus 11 min/patient (8-15) (P repositioning frequency (2 versus 4 h) in patients under MV and on an APAM did not reduce the incidence of pressure ulcers. However, it did increase device-related adverse events and daily nursing workload.

  5. Contrasting characteristics of sub-microsecond pulsed atmospheric air and atmospheric pressure helium-oxygen glow discharges

    International Nuclear Information System (INIS)

    Walsh, J L; Liu, D X; Iza, F; Kong, M G; Rong, M Z

    2010-01-01

    Glow discharges in air are often considered to be the ultimate low-temperature atmospheric pressure plasmas for numerous chamber-free applications. This is due to the ubiquitous presence of air and the perceived abundance of reactive oxygen and nitrogen species in air plasmas. In this paper, sub-microsecond pulsed atmospheric air plasmas are shown to produce a low concentration of excited oxygen atoms but an abundance of excited nitrogen species, UV photons and ozone molecules. This contrasts sharply with the efficient production of excited oxygen atoms in comparable helium-oxygen discharges. Relevant reaction chemistry analysed with a global model suggests that collisional excitation of O 2 by helium metastables is significantly more efficient than electron dissociative excitation of O 2 , electron excitation of O and ion-ion recombination. These results suggest different practical uses of the two oxygen-containing atmospheric discharges, with air plasmas being well suited for nitrogen and UV based chemistry and He-O 2 plasmas for excited atomic oxygen based chemistry. (fast track communication)

  6. FAST TRACK COMMUNICATION: Contrasting characteristics of sub-microsecond pulsed atmospheric air and atmospheric pressure helium-oxygen glow discharges

    Science.gov (United States)

    Walsh, J. L.; Liu, D. X.; Iza, F.; Rong, M. Z.; Kong, M. G.

    2010-01-01

    Glow discharges in air are often considered to be the ultimate low-temperature atmospheric pressure plasmas for numerous chamber-free applications. This is due to the ubiquitous presence of air and the perceived abundance of reactive oxygen and nitrogen species in air plasmas. In this paper, sub-microsecond pulsed atmospheric air plasmas are shown to produce a low concentration of excited oxygen atoms but an abundance of excited nitrogen species, UV photons and ozone molecules. This contrasts sharply with the efficient production of excited oxygen atoms in comparable helium-oxygen discharges. Relevant reaction chemistry analysed with a global model suggests that collisional excitation of O2 by helium metastables is significantly more efficient than electron dissociative excitation of O2, electron excitation of O and ion-ion recombination. These results suggest different practical uses of the two oxygen-containing atmospheric discharges, with air plasmas being well suited for nitrogen and UV based chemistry and He-O2 plasmas for excited atomic oxygen based chemistry.

  7. NRC Information Notice No. 92-67: Deficiency in design modifications to address failures of Hiller actuators upon a gradual loss of air pressure

    International Nuclear Information System (INIS)

    Rossi, C.E.

    1993-01-01

    On January 7, 1992, Carolina Power and Light Company (Shearon Harris Plant) components associated with the air supply to the actuators of the three main feedwater preheater bypass isolation valves were not qualified for a Q class application. Specifically, the failure of the air pump in the non-Q Class, non-seismic instrument air supply to the valve actuator accumulator could prevent pressure switches upstream of the air pump from detecting slow leakage in the Q Class, seismic portion of the actuator air lines. The pressure switches were installed to ensure valve closure by sending an automatic close signal if the instrument air system pressure (upstream of the actuator air pump) dropped to 66 psig as discussed in IN 82-25. The main feedwater preheater bypass isolation valves function as containment isolation valves upon receipt of a feedwater isolation signal. The function of the air pump is to raise the normal instrument air supply pressure from 70 to 100 psig to approximately 150 psig. If accumulator pressure drops from 150 psig to 122 psig, the main feedwater preheater bypass isolation valve may not close within 10 seconds. If pressure drops to a value as low as 20 psig, it may not be sufficient to close the main feedwater preheater bypass isolation valve and keep it closed against the maximum differential pressure across the valve seat. Upon discovery of this condition, Shearon Harris established a surveillance interval for verifying that the actuators' components were functioning properly and that the accumulators were fully pressurized. On January 12, 1992, non-Q components were replaced with suitable components and testing was completed satisfactorily

  8. Influence of surface emission processes on a fast-pulsed dielectric barrier discharge in air at atmospheric pressure

    Science.gov (United States)

    Pechereau, François; Bonaventura, Zdeněk; Bourdon, Anne

    2016-08-01

    This paper presents simulations of an atmospheric pressure air discharge in a point-to-plane geometry with a dielectric layer parallel to the cathode plane. Experimentally, a discharge reignition in the air gap below the dielectrics has been observed. With a 2D fluid model, it is shown that due to the fast rise of the high voltage applied and the sharp point used, a first positive spherical discharge forms around the point. Then this discharge propagates axially and impacts the dielectrics. As the first discharge starts spreading on the upper dielectric surface, in the second air gap with a low preionization density of {{10}4}~\\text{c}{{\\text{m}}-3} , the 2D fluid model predicts a rapid reignition of a positive discharge. As in experiments, the discharge reignition is much slower, a discussion on physical processes to be considered in the model to increase the reignition delay is presented. The limit case with no initial seed charges in the second air gap has been studied. First, we have calculated the time to release an electron from the cathode surface by thermionic and field emission processes for a work function φ \\in ≤ft[3,4\\right] eV and an amplification factor β \\in ≤ft[100,220\\right] . Then a 3D Monte Carlo model has been used to follow the dynamics of formation of an avalanche starting from a single electron emitted at the cathode. Due to the high electric field in the second air gap, we have shown that in a few nanoseconds, a Gaussian cloud of seed charges is formed at a small distance from the cathode plane. This Gaussian cloud has been used as the initial condition of the 2D fluid model in the second air gap. In this case, the propagation of a double headed discharge in the second air gap has been observed and the reignition delay is in rather good agreement with experiments.

  9. The optimum intermediate pressure of two-stages vapor compression refrigeration cycle for Air-Conditioning unit

    Science.gov (United States)

    Ambarita, H.; Sihombing, H. V.

    2018-03-01

    Vapor compression cycle is mainly employed as a refrigeration cycle in the Air-Conditioning (AC) unit. In order to save energy, the Coefficient of Performance (COP) of the need to be improved. One of the potential solutions is to modify the system into multi-stages vapor compression cycle. The suitable intermediate pressure between the high and low pressures is one of the design issues. The present work deals with the investigation of an optimum intermediate pressure of two-stages vapor compression refrigeration cycle. Typical vapor compression cycle that is used in AC unit is taken into consideration. The used refrigerants are R134a. The governing equations have been developed for the systems. An inhouse program has been developed to solve the problem. COP, mass flow rate of the refrigerant and compressor power as a function of intermediate pressure are plotted. It was shown that there exists an optimum intermediate pressure for maximum COP. For refrigerant R134a, the proposed correlations need to be revised.

  10. Application of ultra-high pressure liquid chromatography linear ion-trap orbitrap to qualitative and quantitative assessment of pesticide residues.

    Science.gov (United States)

    Farré, M; Picó, Y; Barceló, D

    2014-02-07

    The analysis of pesticides residues using a last generation high resolution and high mass accuracy hybrid linear ion trap-Orbitrap mass spectrometer (LTQ-Orbitrap-MS) was explored. Pesticides were extracted from fruits, fish, bees and sediments by QuEChERS and from water by solid-phase with Oasis HLB cartridges. Ultra-high pressure liquid chromatography (UHPLC)-LTQ-Orbitrap mass spectrometer acquired full scan MS data for quantification, and data dependent (dd) MS(2) and MS(3) product ion spectra for identification and/or confirmation. The regression coefficients (r(2)) for the calibration curves (two order of magnitude up to the lowest calibration level) in the study were ≥0.99. The LODs for 54 validated compounds were ≤2ngmL(-1) (analytical standards). The relative standard deviation (RSD), which was used to estimate precision, was always lower than 22%. The recovery of extraction and matrix effects ranged from 58 to 120% and from -92 to 52%, respectively. Mass accuracy was always ≤4ppm, corresponding to a maximum mass error of 1.6millimass units (mmu). This procedure was then successfully applied to pesticide residues in a set of the above-mentioned food and environmental samples. In addition to target analytes, this method enables the simultaneous detection/identification of non-target pesticides, pharmaceuticals, drugs of abuse, mycotoxins, and their metabolites. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Metals accumulations during thermal processing of sewage sludge - characterization of bottom ash and air pollution control (APC) residues

    Science.gov (United States)

    Kasina, Monika; Kowalski, Piotr R.; Michalik, Marek

    2016-04-01

    Due to increasing mass of sewage sludge, problems in its management have appeared. Over years sewage sludge was landfilled, however due to EU directives concerning environmental issues this option is no longer possible. This type of material is considered hazardous due to highly concentrated metals and harmful elements, toxic organic substances and biological components (e.g. parasites, microbes). Currently in Europe, incineration is considered to be the most reasonable method for sewage sludge treatment. As a result of sludge incineration significant amount of energy is recovered due to high calorific value of sewage sludge but bottom ash and APC residues are being produced. In this study we show the preliminary results of chemical and mineral analyses of both bottom ash and APC residues produced in fluidized bed boiler in sewage sludge incineration plant in Poland, with a special emphasis on metals which, as a part of incombustible fraction can accumulate in the residual materials after thermal processing. The bottom ash was a SiO2-P2O5-Fe2O3-CaO-Al2O3 dominated material. Main mineral phases identified in X-ray diffraction patterns were: quartz, feldspar, hematite, and phosphates (apatite and scholzite). The bottom ash was characterized by high content of Zn - 4472 mg kg-1, Cu - 665.5 mg kg-1, Pb - 138 mg kg-1, Ni - 119.5 mg kg-1, and interestingly high content of Au - 0.858 mg kg-1 The APC residues composition was dominated by soluble phases which represent more than 90% of the material. The XRD patterns indicated thenardite, halite, anhydrite, calcite and apatite as main mineral phases. The removal of soluble phases by dissolution in deionised water caused a significant mass reduction (ca. 3% of material remained on the filters). Calcite, apatite and quartz were main identified phases. The content of metals in insoluble material is relatively high: Zn - 6326 mg kg-1, Pb - 514.3 mg kg-1, Cu - 476.6 mg kg-1, Ni - 43.3 mg kg-1. The content of Cd, As, Se and Hg was

  12. Comparison of air-fluidized therapy with other support surfaces used to treat pressure ulcers in nursing home residents.

    Science.gov (United States)

    Ochs, Rachel F; Horn, Susan D; van Rijswijk, Lia; Pietsch, Catherine; Smout, Randall J

    2005-02-01

    To provide empirical evidence comparing pressure ulcer healing rates between different support surfaces, data were analyzed from eligible residents with pressure ulcers (N = 664) enrolled in the National Pressure Ulcer Long-Term Care Study, a retrospective pressure ulcer prevention and treatment study. Support surfaces were categorized as: Group 1 (static overlays and replacement mattresses), Group 2 (low-air-loss beds, alternating pressure, and powered/non-powered overlays/mattresses), and Group 3 (air-fluidized beds). Calculation of healing rates, using the largest ulcer from each resident, found mean healing rates greatest for air-fluidized therapy (Group 3) (mean = 5.2 cm(2)/week) versus Group 1 (mean =1.5 cm(2)/week) and Group 2 (mean = 1.8 cm(2)/week) surfaces (P = 0.007). Healing rates also were assessed using 7- to 10-day "episodes"; each ulcer generated separate episode(s) that included all ulcers when residents had multiple ulcers. Mean healing rates were significantly greater for Stage III/IV ulcers on Group 3 surfaces (mean = 3.1 cm(2)/week) versus Group 1 (mean = 0.6 cm(2)/week) and Group 2 (mean = 0.7 cm(2)/week) surfaces (Group 2 versus Group 3: P = 0.0211). This finding persisted for ulcers with comparable initial baseline areas (20 cm(2) to 75 cm(2)) on Group 2 and Group 3 surfaces; healing improved on Group 3 surfaces (+2.3 cm(2)/week) versus Group 2 surfaces (-2.1 cm(2)/week, P = 0.0399). Residents on Group 3 (6 out of 82; 7.3%) and Group 1 (47 out of 461; 10.2%) surfaces had fewer hospitalizations and emergency room visits than those on Group 2 surfaces (23 out of 121; 19.0%, P = 0.01) despite significantly greater illness in residents on Group 2 and 3 versus Group 1 surfaces (P is less than 0.0001). Despite limitations inherent in retrospective studies, ulcers on Group 3 surfaces versus Groups 1 and Group 2 surfaces had statistically significant faster healing rates (particularly for Stage III/IV ulcers) with significantly fewer

  13. Research on the water hammer protection of the long distance water supply project with the combined action of the air vessel and over-pressure relief valve

    International Nuclear Information System (INIS)

    Li, D D; Jiang, J; Zhao, Z; Yi, W S; Lan, G

    2013-01-01

    We take a concrete pumping station as an example in this paper. Through the calculation of water hammer protection with a specific pumping station water supply project, and the analysis of the principle, mathematical models and boundary conditions of air vessel and over-pressure relief valve we show that the air vessel can protect the water conveyance system and reduce the transient pressure damage due to various causes. Over-pressure relief valve can effectively reduce the water hammer because the water column re-bridge suddenly stops the pump and prevents pipeline burst. The paper indicates that the combination set of air vessel and over-pressure relief valve can greatly reduce the quantity of the air valve and can eliminate the water hammer phenomenon in the pipeline system due to the vaporization and water column separation and re-bridge. The conclusion could provide a reference for the water hammer protection of long-distance water supply system

  14. Simultaneous stripping recovery of ammonia-nitrogen and precipitation of manganese from electrolytic manganese residue by air under calcium oxide assist.

    Science.gov (United States)

    Chen, Hongliang; Liu, Renlong; Shu, Jiancheng; Li, Wensheng

    2015-01-01

    Leaching tests of electrolytic manganese residue (EMR) indicated that high contents of soluble manganese and ammonia-nitrogen posed a high environmental risk. This work reports the results of simultaneous stripping recovery of ammonia-nitrogen and precipitation of manganese by air under calcium oxide assist. The ammonia-nitrogen stripping rate increased with the dosage of CaO, the air flow rate and the temperature of EMR slurry. Stripped ammonia-nitrogen was absorbed by a solution of sulfuric acid and formed soluble (NH4)2SO4 and (NH4)3H(SO4)3. The major parameters that effected soluble manganese precipitation were the dosage of added CaO and the slurry temperature. Considering these two aspects, the efficient operation conditions should be conducted with 8 wt.% added CaO, 60°C, 800 mL min(-1) air flow rate and 60-min reaction time. Under these conditions 99.99% of the soluble manganese was precipitated as Mn3O4, which was confirmed by XRD and SEM-EDS analyses. In addition, the stripping rate of ammonia-nitrogen was 99.73%. Leaching tests showed the leached toxic substances concentrations of the treated EMR met the integrated wastewater discharge standard of China (GB8978-1996).

  15. Negative pressure of the environmental air in the cleaning area of the materials and sterilization center: a systematic review

    Directory of Open Access Journals (Sweden)

    Caroline Lopes Ciofi-Silva

    Full Text Available ABSTRACT Objective: to analyze the scientific evidence on aerosols generated during cleaning activities of health products in the Central Service Department (CSD and the impact of the negative pressure of the ambient air in the cleaning area to control the dispersion of aerosols to adjacent areas. Method: for this literature systematic review the following searches were done: search guidelines, manuals or national and international technical standards given by experts; search in the portal and databases PubMed, Scopus, CINAHL and Web of Science; and a manual search of scientific articles. Results: the five technical documents reviewed recommend that the CSD cleaning area should have a negative differential ambient air pressure, but scientific articles on the impact of this intervention were not found. The four articles included talked about aerosols formed after the use of a ultrasonic cleaner (an increased in the contamination especially during use and pressurized water jet (formation of smaller aerosols 5μm. In a study, the aerosols formed from contaminated the hot tap water with Legionella pneumophila were evaluated. Conclusions: there is evidence of aerosol formation during cleanup activities in CSD. Studies on occupational diseases of respiratory origin of workers who work in CSD should be performed.

  16. Define and Quantify the Physics of Air Flow, Pressure Drop and Aerosol Collection in Nuclear Grade HEPA Filters

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Murray E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-23

    Objective: Develop a set of peer-review and verified analytical methods to adjust HEPA filter performance to different flow rates, temperatures and altitudes. Experimental testing will measure HEPA filter flow rate, pressure drop and efficiency to verify the analytical approach. Nuclear facilities utilize HEPA (High Efficiency Particulate Air) filters to purify air flow for workspace ventilation. However, the ASME AG-1 technical standard (Code on Nuclear Air and Gas Treatment) does not adequately describe air flow measurement units for HEPA filter systems. Specifically, the AG-1 standard does not differentiate between volumetric air flow in ACFM (actual cubic feet per minute)compared to mass flow measured in SCFM (standard cubic feet per minute). More importantly, the AG-1 standard has an overall deficiency for using HEPA filter devices at different air flow rates, temperatures, and altitudes. Technical Approach: The collection efficiency and pressure drops of 18 different HEPA filters will be measured over a range of flow rates, temperatures and altitudes. The experimental results will be compared to analytical scoping calculations. Three manufacturers have allocated six HEPA filters each for this effort. The 18 filters will be tested at two different flow rates, two different temperatures and two different altitudes. The 36 total tests will be conducted at two different facilities: the ATI Test facilities (Baltimore MD) and the Los Alamos National Laboratory (Los Alamos NM). The Radiation Protection RP-SVS group at Los Alamos has an aerosol wind tunnel that was originally designed to evaluate small air samplers. In 2010, modifications were started to convert the wind tunnel for HEPA filter testing. (Extensive changes were necessary for the required aerosol generators, HEPA test fixtures, temperature control devices and measurement capabilities.) To this date, none of these modification activities have been funded through a specific DOE or NNSA program. This is

  17. Surface modification of polyester fabrics by atmospheric-pressure air/He plasma for color strength and adhesion enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chunming, E-mail: zcm1229@126.com [College of Textiles and Clothing, Qingdao University, Qingdao 266071 (China); Sunvim Grp Co Ltd, Gaomi 261500 (China); Zhao, Meihua; Wang, Libing; Qu, Lijun [College of Textiles and Clothing, Qingdao University, Qingdao 266071 (China); Men, Yajing [Sunvim Grp Co Ltd, Gaomi 261500 (China)

    2017-04-01

    Highlights: • Air/He plasma gave hydrophilicity on polyester surface and decreased contact angle to 18°. • The roughness of polyester increased and pit-like structures appeared on the surface after plasma treatment. • XPS confirmed the generation of new functional groups on polyester fabric. • The improved pigment color yield and anti-bleeding performance were contributed by the alteration of pigment adhesion. • The air/He plasma was more effective than air plasma at the same treatment time. - Abstract: Surface properties of water-based pigmented inks for ink-jet printed polyester fabrics were modified with atmospheric-pressure air/He plasma to improve the color strength and pigment adhesion of the treated surfaces. The influence of various parameters, including the surface morphology, chemical compositions, surface energy and dynamic contact angles of the control and plasma treated samples was studied. Color strength and edge definition were used to evaluate the ink-jet printing performance of fabrics. The change in pigment adhesion to polyester fibers was analyzed by SEM (scanning electron microscopy). AFM (Atomic force microscope) and XPS (X-ray photoelectron spectroscopy) analyses indicated the increase in surface roughness and the oxygen-containing polar groups(C=O, C−OH and COOH) reinforced the fixation of pigments on the fiber surface. The result from this study suggested that the improved pigment color yield was clearly affected by alteration of pigment adhesion enhanced by plasma surface modification. Polyester fabrics exhibited better surface property and ink-jet printing performance after the air/He mixture plasma treatment comparing with those after air plasma treatment.

  18. Surface modification of polyester fabrics by atmospheric-pressure air/He plasma for color strength and adhesion enhancement

    International Nuclear Information System (INIS)

    Zhang, Chunming; Zhao, Meihua; Wang, Libing; Qu, Lijun; Men, Yajing

    2017-01-01

    Highlights: • Air/He plasma gave hydrophilicity on polyester surface and decreased contact angle to 18°. • The roughness of polyester increased and pit-like structures appeared on the surface after plasma treatment. • XPS confirmed the generation of new functional groups on polyester fabric. • The improved pigment color yield and anti-bleeding performance were contributed by the alteration of pigment adhesion. • The air/He plasma was more effective than air plasma at the same treatment time. - Abstract: Surface properties of water-based pigmented inks for ink-jet printed polyester fabrics were modified with atmospheric-pressure air/He plasma to improve the color strength and pigment adhesion of the treated surfaces. The influence of various parameters, including the surface morphology, chemical compositions, surface energy and dynamic contact angles of the control and plasma treated samples was studied. Color strength and edge definition were used to evaluate the ink-jet printing performance of fabrics. The change in pigment adhesion to polyester fibers was analyzed by SEM (scanning electron microscopy). AFM (Atomic force microscope) and XPS (X-ray photoelectron spectroscopy) analyses indicated the increase in surface roughness and the oxygen-containing polar groups(C=O, C−OH and COOH) reinforced the fixation of pigments on the fiber surface. The result from this study suggested that the improved pigment color yield was clearly affected by alteration of pigment adhesion enhanced by plasma surface modification. Polyester fabrics exhibited better surface property and ink-jet printing performance after the air/He mixture plasma treatment comparing with those after air plasma treatment.

  19. Influence of harvest residues and vegetation on microsite soil and air temperatures in a young conifer plantation.

    Science.gov (United States)

    W.D. Devine; C.A. Harrington

    2007-01-01

    This study examines the effects of bole-only harvesting with and without vegetation control (BO+VC; BO-VC) and total-tree harvesting plus removal of legacy woody debris with vegetation control (TTP+VC) on microsite soil and air temperatures in a young Douglas-fir plantation. Mean soil temperature and the diurnal range in soil temperature during the growing season...

  20. Collimator system for the stabilization of the dynamical residual-gas pressure in the heavy-ion synchrotron SIS18; Kollimatorsystem zur Stabilisierung des dynamischen Restgasdruckes im Schwerionensynchrotron SIS18

    Energy Technology Data Exchange (ETDEWEB)

    Omet, Carsten

    2009-01-15

    In order to achieve higher beam intensities of heavy ion beams in ring accelerators, low charge state ions can be used. By lowering the charge state, the space charge limit is shifted to higher particle numbers and stripping losses can be avoided. During test operation of the SIS18 at GSI with high intensity low charge state heavy ion beams, strong intensity dependent beam losses have been observed. It was found that these beam losses are originated to a large extent by the change of charge state of the circulating ions during collisions with residual gas atoms. The resulting deviation of m/q relative to the reference ion leads, in combination with dispersive elements in the ion optic lattice, to a modified trajectory, followed by the loss of the ion on the beam pipe. At the impact position, loosely bound residual gas molecules are released by ion stimulated desorption which increases the residual gas pressure locally. This pressure rise itself enhances the charge exchange rate, which can develop into a self amplifying process of pressure rise and subsequent beam loss. A method for the stabilization of the dynamic residual gas pressure is the use of special catcher systems, which minimize the production of desorption gases and remove them by strong pumping. Therefore, the pressure on the beam axis should remain as stable as possible. Other processes, e.g. Coulomb scattering of the beam ions by residual gas particles and unavoidable systematic beam losses can increase the gas pressure additionally. The pressure in the accelerator is further subjected to ionization of the residual gas atoms themselves, thermal out gassing of the beam pipes, insertions and pumps. In this work, a detailed numerical model of the interplay between the residual gas pressure dynamics in the accelerator, possible stabilization measures, e.g. by catchers and the resulting beam life time has been developed. The forecasted beam life times and pressures are verified by machine experiments, as

  1. Study of intraocular pressure after 23-gauge and 25-gauge pars plana vitrectomy randomized to fluid versus air fill.

    Science.gov (United States)

    Ho, Lawrence Y; Garretson, Bruce R; Ranchod, Tushar M; Balasubramaniam, Mamtha; Ruby, Alan J; Capone, Antonio; Drenser, Kimberly A; Williams, George A; Hassan, Tarek S

    2011-06-01

    To determine if a difference in intraocular pressure (IOP) exists after small-gauge pars plana vitrectomy randomized to fluid versus 80% sterile air fill. Ninety-two eyes undergoing 23-gauge and 25-gauge transconjunctival pars plana vitrectomy were randomized to fluid versus air fill, and IOP was measured at 5 different time points. There is no difference in the mean IOP for eyes undergoing small-gauge pars plana vitrectomy randomized to fluid versus air fill after vitrectomy. Using 23-gauge instrumentation, the mean immediate and 2-hour postoperative IOPs were statistically lower than the mean preoperative IOP. The mean Postoperative Day 1 and Week 1 IOPs were statistically higher than the mean immediate postoperative IOP. Using 25-gauge instrumentation, the mean IOP was not statistically different at any time points in the 2 groups. When comparing 23-gauge with 25-gauge instrumentation, the immediate postoperative IOP was statistically lower and the rate of suture closure for sclerotomies was higher for 23-gauge vitrectomy. When performing 23-gauge or 25-gauge pars plana vitrectomy, there was no difference in mean IOP for fluid- versus air-filled eyes. However, the mean IOP in the immediate postoperative period was statistically lower, and there was a higher rate of suture closure for 23-gauge compared with 25-gauge instrumentation.

  2. Simulation of convection-stabilized low-current glow and arc discharges in atmospheric-pressure air

    International Nuclear Information System (INIS)

    Naidis, G V

    2007-01-01

    A two-dimensional model of stationary convection-stabilized low-current glow and arc discharge columns in atmospheric-pressure air is developed which accounts for deviation of the plasma state from the local thermodynamic equilibrium (LTE). In addition to equations of energy, continuity and momentum (analogous to those used in LTE arc models), the non-LTE model includes balance equations for plasma species and for the vibrational energy of nitrogen molecules. The kinetic scheme is used which was developed recently for the simulation of low-current wall-stabilized discharges in air. Results of calculation of discharge parameters over a wide current range are presented. It is shown that the non-equilibrium effects are substantial at currents lower than ∼ 100 mA. The calculated plasma parameters agree with available experimental data

  3. Measurement of OH density and air-helium mixture ratio in an atmospheric-pressure helium plasma jet

    International Nuclear Information System (INIS)

    Yonemori, Seiya; Ono, Ryo; Nakagawa, Yusuke; Oda, Tetsuji

    2012-01-01

    The absolute density of OH radicals in an atmospheric-pressure helium plasma jet is measured using laser-induced fluorescence (LIF). The plasma jet is generated in room air by applying a pulsed high voltage onto a quartz tube with helium gas flow. The time-averaged OH density is 0.10 ppm near the quartz tube nozzle, decreasing away from the nozzle. OH radicals are produced from water vapour in the helium flow, which is humidified by water adsorbed on the inner surface of the helium line and the quartz tube. When helium is artificially humidified using a water bubbler, the OH density increases with humidity and reaches 2.5 ppm when the water vapour content is 200 ppm. Two-dimensional distribution of air-helium mixture ratio in the plasma jet is also measured using the decay rate of the LIF signal waveform which is determined by the quenching rate of laser-excited OH radicals. (paper)

  4. Vibration-to-translation energy transfer in atmospheric-pressure streamer discharge in dry and humid air

    Science.gov (United States)

    Komuro, Atsushi; Takahashi, Kazunori; Ando, Akira

    2015-10-01

    Vibration-to-translation (V-T) energy transfer in atmospheric-pressure streamer discharge is numerically simulated using a two-dimensional electro-hydrodynamic model. The model includes state-to-state vibrational kinetics in humid air and is coupled with the compressible flow equation of the gas fluid. The vibrational distribution of {{\\text{O}}2}(v) reaches equilibrium more quickly than that of {{\\text{N}}2}(v) , whereas the energy released from {{\\text{O}}2}(v) does not increase the gas temperature. In humid air, the decay rate of the vibrational energy of {{\\text{N}}2}(v) is accelerated by the V-T energy transfer through water molecules and the energy heats the gas. However, the increase in gas temperature due to V-T energy transfer is not always seen because it competes with thermal diffusion.

  5. The reconstruction of air pressure in Gdańsk in the period of instrumental observations, 1739-2012

    Science.gov (United States)

    Filipiak, Janusz

    2015-04-01

    The purpose of the paper is to characterise the details of reconstruction of air pressure in Gdańsk in the whole period of regular instrumental records spanning the period 1739-2012. Gdańsk pressure series has been reconstructed by joining air pressure observations of 15 local shorter series. The entire instrumental series can be divided into three sub-periods: the Early Observers period, lasting to 1806, the First Meteorological Networks, covering the years from 1807 to 1875 and Modern Measurements begun in 1876. During the first period, observations were made from two to four times per day, sometimes even at midnight. In the 19th century and up to 1945 thrice-daily barometer readings were a standard, in the last few decades the density of data is much denser. A serious gap in the original daily data exists for the period 1849-1875, where it appears that no original source of data have survived. Selected data are presented in the form of five-day or monthly averages. Numerous errors made probably during the re-writing of original observers' data by their assistants were discovered during digitalization. Despite this the quality of observations can be regarded as good. Data have been corrected to provide a monthly-mean measure of atmospheric pressure in the unit of hPa at standard conditions, i.e. standard gravity, 0 °C and at sea level. Some inconsistencies may still arise as the procedure of the homogenization of air temperature is not completed and in case of a few oldest series air temperature was estimated. Numerous breakpoints were identified in the homogenisation of the series and they cannot be always linked to known causes. A reasonably detailed station history has been compiled by incorporating metadata contained in various written sources. These metadata have facilitated the homogenisation of the data series. Mean annual atmospheric pressure in Gdańsk in period 1739-2012 calculated on the basis of homogenized series was 1014.9 hPa. Mean seasonal

  6. The Heterogeneity of Mutational Tolerance in a Protein is Dependent on the Strength of Selective Pressure Correlating with Sectors of Co-evolving Residues

    Science.gov (United States)

    Stiffler, Michael; Ranganathan, Rama

    2011-03-01

    Proteins are capable of tolerating mutations at many positions while still maintaining fold and function. Previous studies have failed to consider how tolerance to random mutagenesis might depend on the strength of selective pressure. To examine this, we measured the fitness of every single point mutation of TEM-1 beta-lactamase across a range of ampicillin concentrations utilizing a novel application of deep-sequencing. We found that the relative mutational robustness between positions varied considerably with respect to ampicillin concentration: at a low ampicillin concentration only a few positions are intolerant of mutations, while at a higher ampicillin concentration many additional positions are as equally intolerant of mutations. Using an analytic method termed statistical coupling analysis (SCA) to measure the co-variation between all positions in a sequence alignment of beta-lactamases revealed sectors of co-evolving positions associated with groups of residues having increased sensitivity to mutagenesis at either low or high ampicillin concentrations. Our findings suggest that nature has ``designed'' proteins to be robust to random mutagenesis by loading the constraints for fitness on discrete networks of co-evolving positions depending on the strength of selective pressure.

  7. Supra-thermal charged particle energies in a low pressure radio-frequency electrical discharge in air

    International Nuclear Information System (INIS)

    Littlefield, R.G.

    1976-01-01

    Velocity spectra of supra-thermal electrons escaping from a low-pressure radio-frequency discharge in air have been measured by a time-of-flight method of original design. In addition, the energy spectra of the supra-thermal electrons and positive ions escaping from the rf discharge have been measured by a retarding potential method. Various parameters affecting the energy of the supra-thermal charged particles are experimentally investigated. A model accounting for the supra-thermal charged particle energies is developed and is shown to be consistent with experimental observations

  8. Impact of Spatial Resolution on Wind Field Derived Estimates of Air Pressure Depression in the Hurricane Eye

    Directory of Open Access Journals (Sweden)

    Linwood Jones

    2010-03-01

    Full Text Available Measurements of the near surface horizontal wind field in a hurricane with spatial resolution of order 1–10 km are possible using airborne microwave radiometer imagers. An assessment is made of the information content of the measured winds as a function of the spatial resolution of the imager. An existing algorithm is used which estimates the maximum surface air pressure depression in the hurricane eye from the maximum wind speed. High resolution numerical model wind fields from Hurricane Frances 2004 are convolved with various HIRAD antenna spatial filters to observe the impact of the antenna design on the central pressure depression in the eye that can be deduced from it.

  9. Numerical Modelling of Soot Formation in Laminar Axisymmetric Ethylene-Air Coflow Flames at Atmospheric and Elevated Pressures

    KAUST Repository

    Abdelgadir, Ahmed

    2015-03-30

    A set of coflow diffusion flames are simulated to study the formation, growth, and oxidation of soot in flames of diluted hydrocarbon fuels, with focus on the effects of pressure. Firstly, we assess the ability of a high performance CFD solver, coupled with detailed transport and kinetic models, to reproduce experimental measurements of a series of ethylene-air coflow flames. Detailed finite rate chemistry describing the formation of Polycyclic Aromatic Hydro-carbons is used. Soot is modeled with a moment method and the resulting moment transport equations are solved with a Lagrangian numerical scheme. Numerical and experimental results are compared for various pressures. Finally, a sensitivity study is performed assessing the effect of the boundary conditions and kinetic mechanisms on the flame structure and stabilization properties.

  10. Seasonal and spatial variations of glyphosate residues in surface waters of El Crespo stream, Buenos Aires province, Argentina.

    Science.gov (United States)

    Perez, Debora; Okada, Elena; Aparicio, Virginia; Menone, Mirta; Costa, Jose Luis

    2017-04-01

    El Crespo stream is located inside a small watershed (52,000 Ha) which is only influenced by farming activities without urban or industrial impact. The watershed can be divided in two areas, the southern area (upstream), mainly composed of intensive crops and the northern area (downstream) used only for extensive livestock. In this sense, "El Crespo" stream in an optimal site for monitoring screening of pesticide residues. The objective of this work was to determine the seasonal and spatial variations of glyphosate (GLY), in surface waters of "El Crespo" stream. We hypothesized that in surface waters of "El Crespo" stream the levels of GLY vary depending of the season and rainfall events. The water sampling was carried out from October to June (2014-2015) in two sites: upstream (US) and downstream (DS), before and after rain events. The water samples were collected by triplicate in 1 L polypropylene bottles and stored at -20°C until analysis. GLY was extracted from unfiltered water samples with a buffer solution (100 mM Na2B4O7•10H2O/100 mM K3PO4, pH=9) and derivatized with 9-fluorenylmethylchloroformate (1 mg/mL in acetonitrile). Afterwards samples were analyzed using liquid chromatography coupled to a tandem mass spectrometer (UPLC-MS/MS). The detection limit (LD) was 0.1 μg/L and the quantification limit (QL) was 0.5 μg/L. The rainfall regime was obtained from the database of INTA Balcarce. GLY was detected in 92.3% of the analyzed samples. In the US site, were GLY is regularly applied, the highest GLY concentration was registered in October (2.15 ± 0.16 μg/L); from November to June, the GLY levels decreased from 1.97 ± 0.17 μg/L to residues found in October and November in both sites could be explained by the use of GLY in

  11. Residual deposits (residual soil)

    International Nuclear Information System (INIS)

    Khasanov, A.Kh.

    1988-01-01

    Residual soil deposits is accumulation of new formate ore minerals on the earth surface, arise as a result of chemical decomposition of rocks. As is well known, at the hyper genes zone under the influence of different factors (water, carbonic acid, organic acids, oxygen, microorganism activity) passes chemical weathering of rocks. Residual soil deposits forming depends from complex of geologic and climatic factors and also from composition and physical and chemical properties of initial rocks

  12. Dynamic Oil-Water and Air-Water Capillary Pressure-Saturation Curves: Experiments and Lattice-Boltzmann Simulations

    Science.gov (United States)

    Porter, M. L.; Schaap, M. G.; Wildenschild, D.

    2006-12-01

    Capillary pressure plays a significant role in multiphase flow and transport in porous media. Although capillary forces occur at the pore-scale, many mathematical models require a macro-scale relationship between capillary pressure and other properties of the system. The capillary pressure-saturation curve is the most widely used relationship to characterize hydraulic properties of multiphase flow in porous media. These curves are most commonly obtained from quasi-static drainage and imbibition experiments. It is then often assumed that the quasi-static curves can be applied to modeling transient flow conditions. In these models, the time it takes to reach a quasi-static state is completely ignored, which can be on the order of hours to months. Experimental evidence suggests that capillary pressure-saturation curves are not unique and that they exhibit dynamic effects depending on the flow conditions in the the system prior to and during the time of measurement. The extent to which dynamic flow conditions effect the measured capillary pressure is currently debated and the exact cause of the observed dynamic effects is not fully understood. In this study various drainage and imbibition experiments were conducted to further investigate the role dynamic effects play in the capillary pressure-saturation curve. Oil-water and air-water experiments were conducted on the same porous medium to compare the dynamic effects resulting from density and viscosity differences. Lattice-Boltzmann simulations of the dynamic effects were carried out to provide a comparison to the experimental results. The simulation results were then analyzed in an effort to identify the pore-scale mechanisms responsible for the dynamic effects observed in the macro-scale experiments.

  13. The Oxidation of Fe(II) in Acidic Sulfate Solutions with Air at Elevated Pressures : Part 2. Influence of H2SO4 and Fe(III)

    NARCIS (Netherlands)

    Wermink, Wouter N.; Versteeg, Geert F.

    2017-01-01

    The oxidation of ferrous ions in acidic sulfate solutions at elevated air pressures was investigated. The effect of the Fe2+ concentration, Fe3+ concentration H2SO4 concentration, and partial oxygen pressure on the reaction rate were determined at three different temperatures, that is, T = 90, 70,

  14. The Oxidation of Fe(II) in Acidic Sulfate Solutions with Air at Elevated Pressures : Part 1. Kinetics above 1 M H2SO4

    NARCIS (Netherlands)

    Wermink, Wouter N.; Versteeg, Geert F.

    2017-01-01

    The oxidation of ferrous ions in acidic sulfate solutions at elevated air pressures was investigated. The effect of the Fe2+ concentration, initial H2SO4 concentration and partial oxygen pressure on the reaction rate were determined at three different temperatures, that is, T = 90, 70, and 50

  15. Impact of changes of positive end-expiratory pressure on functional residual capacity at low tidal volume ventilation during general anesthesia.

    Science.gov (United States)

    Satoh, Daizoh; Kurosawa, Shin; Kirino, Wakaba; Wagatsuma, Toshihiro; Ejima, Yutaka; Yoshida, Akiko; Toyama, Hiroaki; Nagaya, Kei

    2012-10-01

    Several reports in the literature have described the effects of positive end-expiratory pressure (PEEP) level upon functional residual capacity (FRC) in ventilated patients during general anesthesia. This study compares FRC in mechanically low tidal volume ventilation with different PEEP levels during upper abdominal surgery. Before induction of anesthesia (awake) for nine patients with upper abdominal surgery, a tight-seal facemask was applied with 2 cmH(2)O pressure support ventilation and 100 % O(2) during FRC measurements conducted on patients in a supine position. After tracheal intubation, lungs were ventilated with bilevel airway pressure with a volume guarantee (7 ml/kg predicted body weight) and with an inspired oxygen fraction (FIO(2)) of 0.4. PEEP levels of 0, 5, and 10 cmH(2)O were used. Each level of 5 and 10 cmH(2)O PEEP was maintained for 2 h. FRC was measured at each PEEP level. FRC awake was significantly higher than that at PEEP 0 cmH(2)O (P cmH(2)O was significantly lower than that at 10 cmH(2)O (P cmH(2)O (P cmH(2)O was significantly lower than that for PEEP 5 cmH(2)O or PEEP 10 cmH(2)O (P cmH(2)O, PEEP 5 cmH(2)O after 2 h, and PEEP 10 cmH(2)O after 2 h were correlated with FRC (R = 0.671, P cmH(2)O is necessary to maintain lung function if low tidal volume ventilation is used during upper abdominal surgery.

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

    Science.gov (United States)

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

    2014-01-01

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

  17. Residual gas analysis

    International Nuclear Information System (INIS)

    Berecz, I.

    1982-01-01

    Determination of the residual gas composition in vacuum systems by a special mass spectrometric method was presented. The quadrupole mass spectrometer (QMS) and its application in thin film technology was discussed. Results, partial pressure versus time curves as well as the line spectra of the residual gases in case of the vaporization of a Ti-Pd-Au alloy were demonstrated together with the possible construction schemes of QMS residual gas analysers. (Sz.J.)

  18. OH and O radicals production in atmospheric pressure air/Ar/H2O gliding arc discharge plasma jet

    Science.gov (United States)

    N, C. ROY; M, R. TALUKDER; A, N. CHOWDHURY

    2017-12-01

    Atmospheric pressure air/Ar/H2O gliding arc discharge plasma is produced by a pulsed dc power supply. An optical emission spectroscopic (OES) diagnostic technique is used for the characterization of plasmas and for identifications of {{OH}} and {{O}} radicals along with other species in the plasmas. The OES diagnostic technique reveals the excitation T x ≈ 5550–9000 K, rotational T r ≈ 1350–2700 K and gas T g ≈ 850–1600 K temperatures, and electron density {n}{{e}}≈ ({1.1-1.9})× {10}14 {{{cm}}}-3 under different experimental conditions. The production and destruction of {{OH}} and {{O}} radicals are investigated as functions of applied voltage and air flow rate. Relative intensities of {{OH}} and {{O}} radicals indicate that their production rates are increased with increasing {{Ar}} content in the gas mixture and applied voltage. {n}{{e}} reveals that the higher densities of {{OH}} and {{O}} radicals are produced in the discharge due to more effective electron impact dissociation of {{{H}}}2{{O}} and {{{O}}}2 molecules caused by higher kinetic energies as gained by electrons from the enhanced electric field as well as by enhanced {n}{{e}}. The productions of {{OH}} and {{O}} are decreasing with increasing air flow rate due to removal of Joule heat from the discharge region but enhanced air flow rate significantly modifies discharge maintenance properties. Besides, {T}{{g}} significantly reduces with the enhanced air flow rate. This investigation reveals that {{Ar}} plays a significant role in the production of {{OH}} and {{O}} radicals.

  19. Pressure Measurement in Supersonic Air Flow by Differential Absorptive Laser-Induced Thermal Acoustics

    Science.gov (United States)

    Hart, Roger C.; Herring, Gregory C.; Balla, Robert J.

    2007-01-01

    Nonintrusive, off-body flow barometry in Mach-2 airflow has been demonstrated in a large-scale supersonic wind tunnel using seedless laser-induced thermal acoustics (LITA). The static pressure of the gas flow is determined with a novel differential absorption measurement of the ultrasonic sound produced by the LITA pump process. Simultaneously, stream-wise velocity and static gas temperature of the same spatially-resolved sample volume were measured with this nonresonant time-averaged LITA technique. Mach number, temperature and pressure have 0.2%, 0.4%, and 4% rms agreement, respectively, in comparison with known free-stream conditions.

  20. Effect of electrode configuration on the uniformity of atmospheric pressure surface dielectric barrier air micro-discharge

    Science.gov (United States)

    Xia, Yang; Bi, Zhenhua; Qi, Zhihua; Ji, Longfei; Zhao, Yao; Chang, Xuewei; Wang, Wenchun; Liu, Dongping

    2018-02-01

    The electrode configuration of atmospheric pressure air discharge is one of the key elements that have significant effects on the discharge properties. In this study, double-sided printed circuit boards with square-shaped lattice structure are used to generate surface dielectric barrier air micro-discharge (SDBAMD) at atmospheric pressure. The effects of the lattice width on the discharge properties are reported. The uniformity of the SDBAMD is evaluated by adopting the digital image processing method. Our measurements show that the power and ignition voltage of the SDBAMD significantly depended on the configuration of the grounded electrode. The digital image processing results show that the uniformity of the SDBAMD is severely affected by the lattice width, and the most uniform discharge is achieved at the lattice width of 2.0 mm. The numerical model based on COMSOL demonstrated that increasing the lattice width can lead to an increase in the electric field in the vicinity of the grounded electrode and a decrease in the lattice center. Furthermore, our analysis suggests that the different electrode configurations can change the interaction between the space charges during the discharge, which ultimately affects the uniformity of the SDBAMD.

  1. Characterization of atmospheric pressure plasma treated pure cashmere and wool/cashmere textiles: Treatment in air/water vapor mixture

    Energy Technology Data Exchange (ETDEWEB)

    Zanini, Stefano, E-mail: stefano.zanini@mib.infn.it [Università degli Studi di Milano-Bicocca, Dipartimento di Fisica “G. Occhialini”, p.za della Scienza, 3, I-20126 Milano (Italy); Grimoldi, Elisa [Università degli Studi di Milano-Bicocca, Dipartimento di Fisica “G. Occhialini”, p.za della Scienza, 3, I-20126 Milano (Italy); Citterio, Attilio [Politecnico di Milano, Dipartimento di Chimica, Materiali ed Ingegneria Chimica “G. Natta”, Via Mancinelli 7, I-20131 Milano (Italy); Riccardi, Claudia, E-mail: riccardi@mib.infn.it [Università degli Studi di Milano-Bicocca, Dipartimento di Fisica “G. Occhialini”, p.za della Scienza, 3, I-20126 Milano (Italy)

    2015-09-15

    Highlights: • We treated cashmere and wool/cashmere textiles with atmospheric pressure plasma. • Wettability of the fabrics was increased. • The increment in wettability derived from a surface oxidation of the fibers. • Only minor etching effects were observed with scanning electron microscopy. - Abstract: We performed atmospheric pressure plasma treatments of pure cashmere and wool/cashmere textiles with a dielectric barrier discharge (DBD) in humid air (air/water vapor mixtures). Treatment parameters have been optimized in order to enhance the wettability of the fabrics without changing their bulk properties as well as their touch. A deep characterization has been performed to study the wettability, the surface morphologies, the chemical composition and the mechanical properties of the plasma treated textiles. The chemical properties of the plasma treated samples were investigated with attenuated total reflectance Fourier transform infrared (FTIR/ATR) spectroscopy and X-ray photoelectron microscopy (XPS). The analyses reveal a surface oxidation of the treated fabrics, which enhances their surface wettability. Morphological characterization of the treated fibers with scanning electron microscopy (SEM) reveals minor etching effects, an essential feature for the maintenance of the textile softness.

  2. Estimation of Flow Channel Parameters for Flowing Gas Mixed with Air in Atmospheric-pressure Plasma Jets

    Science.gov (United States)

    Yambe, Kiyoyuki; Saito, Hidetoshi

    2017-12-01

    When the working gas of an atmospheric-pressure non-equilibrium (cold) plasma flows into free space, the diameter of the resulting flow channel changes continuously. The shape of the channel is observed through the light emitted by the working gas of the atmospheric-pressure plasma. When the plasma jet forms a conical shape, the diameter of the cylindrical shape, which approximates the conical shape, defines the diameter of the flow channel. When the working gas flows into the atmosphere from the inside of a quartz tube, the gas mixes with air. The molar ratio of the working gas and air is estimated from the corresponding volume ratio through the relationship between the diameter of the cylindrical plasma channel and the inner diameter of the quartz tube. The Reynolds number is calculated from the kinematic viscosity of the mixed gas and the molar ratio. The gas flow rates for the upper limit of laminar flow and the lower limit of turbulent flow are determined by the corresponding Reynolds numbers estimated from the molar ratio. It is confirmed that the plasma jet length and the internal plasma length associated with strong light emission increase with the increasing gas flow rate until the rate for the upper limit of laminar flow and the lower limit of turbulent flow, respectively. Thus, we are able to explain the increasing trend in the plasma lengths with the diameter of the flow channel and the molar ratio by using the cylindrical approximation.

  3. On the measurement of residual stress by x-ray diffraction in a weldment of pressure vessel steel A533-B

    International Nuclear Information System (INIS)

    Larsson, L.E.

    1981-11-01

    The aim with this work was to compare strain data obtained using the film-or cameramethod and the diffractometermethod for residual stress measurement by X-ray diffraction. The measurements were carried out on a weldment of pressure vessel steel A533-B. The strain can be measured by non-destructive methods, i.e. magnetic, ultrasonic or X-ray methods. The X-ray diffraction method has been used for several decades and the accuracy is high. The incident X-ray is reflected as a Debye-Scherrer cone. As the film-method is based on the reflex from a very small surface, contrary to what is used by the diffractometermethod, the reference γ=0, i.e. the normal to the original surface, is very sensitive for small defects in the reflecting point, which leads to deviation from the true values. The strain has been obtained by the filmmethod and the diffractometer on the same specimen. In the first case the Debye-ring was obtained at γ=0 and γ=45 degrees and the difference D was calculated. In the second case the interplanar spacing d(γ) was obtained at five angles between 0 and 60 degrees and Δd=d 45 -d was calculated from the linear d-sin 2 γ plot. Roughly, the values agree, but insecurity is rather high in the ΔD-values. In the present work the residual stresses and the linebroadening of the X-ray profile have been calculated from the diffractometer-data. At a distance of 75-100 mm from the weldment the material is stressfree. The linebroadening depends on the microstructure and the microstrain. (Author)

  4. Design of a compressed air modulator to be used in comprehensive multidimensional gas chromatography and its application in the determination of pesticide residues in grapes.

    Science.gov (United States)

    Pizzutti, Ionara R; Vreuls, René J J; de Kok, André; Roehrs, Rafael; Martel, Samile; Friggi, Caroline A; Zanella, Renato

    2009-04-10

    In this study, a new modulator that is simple, robust and presents low operation costs, was developed. This modulator uses compressed air to cool two small portions in the first centimeters of the second chromatographic column of a comprehensive multidimensional gas chromatography (GCxGC) system. The results show a variation in the peak area less than 3 and 5% to alkanes and pesticides, respectively. The standard deviations for the retention times in the first and second dimension are around 0.05 min and 0.05s for all the compounds. The system was optimized with n-alkanes. The GCxGC system proposed was applied in the determination of pyrethroid pesticides (bifenthrin, cypermethrin, deltamethrin, fenvalerate, esfenvalerate, cis- and trans-permethrin) in grape samples. Samples were extracted by the mini-Luke modified method and pesticides were quantified by comprehensive multidimensional gas chromatography with micro electron-capture detection (microECD). The values of method limit of quantification (LOQ) were 0.01-0.02 mg kg(-1) for all studied pyrethroid and the values of recovery were between 94.3 and 115.2%, with good precision (RSDcompressed air has the potential for application in the analysis of a wider range of pesticide residues in other commodities since it provides low values of LOQ with acceptable accuracy and precision.

  5. Safety concerns in ultrahigh pressure capillary liquid chromatography using air-driven pumps.

    Science.gov (United States)

    Xiang, Yanqiao; Maynes, Daniel R; Lee, Milton L

    2003-04-04

    Ultrahigh pressure liquid chromatography (UHPLC) is an emerging technique which utilizes pressures higher than 10,000 p.s.i. to overcome the flow resistance imposed when using very small particles as packing materials in fused-silica capillary columns (1 p.s.i.=6894.76 Pa). This technique has demonstrated exceptionally high separation speeds and chromatographic efficiencies. However, safety is a concern when extremely high pressures are used. In this study, the safety aspects of capillary column rupture during operation were identified and carefully evaluated. First, liquid jets may be formed as a result of blow-out of the on-column frits or from rupture of the capillary at or near the column inlet. Second, incorrect installation of the capillary at the injector, failure of the ferrule used in the capillary connection, or rupture of the capillary can produce high speed projectiles of silica particles or column fragments. Experiments were carried out in the laboratory to produce liquid (water) jets and capillary projectiles using a UHPLC system, and the power density, an important parameter describing water jets in industrial practice, was calculated. Experimental results were in accordance with theoretical calculations. Both indicated that water jets and capillary projectiles under ultrahigh pressures might lead to skin penetration under limited conditions. The use of a plexiglass shroud to cover an initial length of the installed capillary column can eliminate any safety-related concerns about liquid jets or capillary projectiles.

  6. A randomized comparison of the i-gel with the self-pressurized air-Q intubating laryngeal airway in children.

    Science.gov (United States)

    Kim, Min-Soo; Lee, Jae Hoon; Han, Sang Won; Im, Young Jae; Kang, Hyo Jong; Lee, Jeong-Rim

    2015-04-01

    Supraglottic airway devices with noninflatable cuff have advantages in omitting the cuff pressure monitoring and reducing potential pharyngolaryngeal complications. Typical devices without cuff inflation available in children are the i-gel and the self-pressurized air-Q intubating laryngeal airway (air-Q SP). To date, there is no comparative study between these devices in pediatric patients. The purpose of this randomized study was to compare the i-gel(™) and the self-pressurized air-Q(™) intubating laryngeal airway (air-Q SP) in children undergoing general anesthesia. Eighty children, 1-108 months of age, 7-30 kg of weight, and scheduled for elective surgery in which supraglottic airway devices would be suitable for airway management, were randomly assigned to either the i-gel or the air-Q SP. Oropharyngeal leak pressure and fiberoptic view were assessed three times as follows: after insertion and fixation of the device, 10 min after initial assessment, and after completion of surgery. We also assessed insertion parameters and complications. Insertion of the i-gel was regarded as significantly easier compared to the air-Q SP (P = 0.04). Compared to the air-Q SP group, the i-gel group had significantly higher oropharyngeal leak pressures at all measurement points and significantly lower frequencies of gastric insufflation at 10 min after initial assessment and completion of surgery. The air-Q SP group had better fiberoptic views than the i-gel group at all measurement points. Our results showed that the i-gel had easier insertion and better sealing function, and the air-Q SP provided improved fiberoptic views in children requiring general anesthesia. © 2015 John Wiley & Sons Ltd.

  7. Intraoperative measurement of intraocular pressure in vitrectomized aphakic air-filled eyes using the Tono-Pen XL.

    Science.gov (United States)

    Badrinath, S S; Vasudevan, R; Murugesan, R; Basti, S; Nicholson, A D; Singh, P; Gopal, L; Sharma, T; Rao, S B; Abraham, C

    1993-01-01

    The Tono-Pen XL (Bio-Rad, Santa Ana, CA) was compared with manometer readings for intraoperative measurement of intraocular pressure (IOP) in 40 eyes of 40 consecutive patients after vitrectomy, lensectomy, and fluid-air exchange. Tono-Pen readings corresponding to manometer readings of 10, 20, 30, 40, and 50 mmHg were obtained in a masked fashion with a randomized sequence of manometer readings. A correlation was obtained between the manometer and Tono-Pen readings (r = 0.96 in emmetropic eyes and r = 0.93 in myopic eyes). The regression curve that represents the calibration curve of Tono-Pen in terms of the manometer readings for air-filled vitrectomized eyes was obtained. Any Tono-Pen reading can be easily translated into the corresponding manometer reading by referring to the curve. The Tono-Pen can therefore be effectively used to accurately determine intraoperative IOP in eyes undergoing vitrectomy, lensectomy, and fluid-air exchange.

  8. Surface modification of polyester fabrics by atmospheric-pressure air/He plasma for color strength and adhesion enhancement

    Science.gov (United States)

    Zhang, Chunming; Zhao, Meihua; Wang, Libing; Qu, Lijun; Men, Yajing

    2017-04-01

    Surface properties of water-based pigmented inks for ink-jet printed polyester fabrics were modified with atmospheric-pressure air/He plasma to improve the color strength and pigment adhesion of the treated surfaces. The influence of various parameters, including the surface morphology, chemical compositions, surface energy and dynamic contact angles of the control and plasma treated samples was studied. Color strength and edge definition were used to evaluate the ink-jet printing performance of fabrics. The change in pigment adhesion to polyester fibers was analyzed by SEM (scanning electron microscopy). AFM (Atomic force microscope) and XPS (X-ray photoelectron spectroscopy) analyses indicated the increase in surface roughness and the oxygen-containing polar groups(Cdbnd O, Csbnd OH and COOH) reinforced the fixation of pigments on the fiber surface. The result from this study suggested that the improved pigment color yield was clearly affected by alteration of pigment adhesion enhanced by plasma surface modification. Polyester fabrics exhibited better surface property and ink-jet printing performance after the air/He mixture plasma treatment comparing with those after air plasma treatment.

  9. Measurement of the pressure dependence of air fluorescence emision induced by electronos

    Czech Academy of Sciences Publication Activity Database

    Ave, M.; Boháčová, Martina; Hrabovský, Miroslav; Nožka, Libor; Palatka, Miroslav; Řídký, Jan; Schovánek, Petr

    2007-01-01

    Roč. 28, č. 1 (2007), s. 41-57 ISSN 0927-6505 R&D Projects: GA MŠk LA 134; GA MŠk LC527 Institutional research plan: CEZ:AV0Z10100502 Keywords : air fluorescence detection * ultra high energy cosmic rays * nitrogen collisional quenching Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 3.483, year: 2007

  10. Spectrally resolved pressure dependence measurements of air fluorescence emission with AIRFLY

    Czech Academy of Sciences Publication Activity Database

    Ave, M.; Boháčová, Martina; Buonomo, B.; Hrabovský, Miroslav; Nožka, Libor; Palatka, Miroslav; Řídký, Jan; Schovánek, Petr

    2008-01-01

    Roč. 597, č. 1 (2008), s. 41-45 ISSN 0168-9002 R&D Projects: GA MŠk LC527; GA MŠk(CZ) LA08016; GA MŠk(CZ) 1M06002 Institutional research plan: CEZ:AV0Z10100502; CEZ:AV0Z10100522 Keywords : air fluorescence * cosmic rays Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.019, year: 2008

  11. Residues of organophosphate pesticides used in vegetable cultivation in ambient air, surface water and soil in Bueng Niam Subdistrict, Khon Kaen, Thailand.

    Science.gov (United States)

    Harnpicharnchai, Kallaya; Chaiear, Naesinee; Charerntanyarak, Lertchai

    2013-11-01

    Agricultural pesticide utilization is one of the important problems in rural and urban crop-cultivated areas, with the majority of pollutants dispersing via ambient air, water and other natural pathways. This study was therefore conducted in a specially selected village which is known to be a leading vegetable growing area in Khon Kaen Province. The aim of the study was to assess pesticide residues, and measure the seasonal fluctuations in organophosphate concentrations during 2010 in the environment of a risk area. Samples from selected sites were collected in two phases: Phase I was in summer (during March to May) and Phase II was in winter (during October to December). A total of 150 samples were analyzed using gas chromatography with flame photometric detection. The results showed that dicrotophos, chlorpyrifos, profenofos and ethion were found at the highest concentrations in soil and at the lowest concentrations in ambient air (ppesticide in ambient air samples was 0.2580 +/- 0.2686 mg/m(3) for chlorpyrifos in summer and 0.1003 +/- 0.0449 mg/m(3) for chlorpyrifos in winter. In surface water samples, the highest mean concentration of a pesticide was 1.3757 +/- 0.5014 mg/l for dicrotophos in summer and 0.3629 +/- 0.4338 mg/l for ethion in winter. The highest mean concentration of a pesticide in soil samples was 42.2893 +/- 39.0711 mg/kg ethion in summer and 90.0000 +/- 24.1644 mg/kg of ethion in winter.

  12. Air

    CERN Document Server

    Rivera, Andrea

    2017-01-01

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

  13. Electric field measurements in near-atmospheric pressure nitrogen and air based on a four-wave mixing scheme

    International Nuclear Information System (INIS)

    Mueller, Sarah; Luggenhoelscher, Dirk; Czarnetzki, Uwe; Ito, Tsuyohito; Kobayashi, Kazunobu; Hamaguchi, Satoshi

    2010-01-01

    Electric fields are measured for the first time in molecular nitrogen at atmospheric pressures. Measurements are performed in either pure nitrogen or air. The laser spectroscopic technique applied here is based on a CARS-like four-wave mixing scheme originally developed for measurements in molecular hydrogen by Ochkin and Tskhai in 1995. The technique is ideal for investigation of microdischarges at atmospheric pressures. The frequencies of two focussed laser beams in the visible are tuned to match the energy difference between the two lowest vibrational levels in nitrogen. The presence of a static electric field then leads to the emission of coherent IR radiation at this difference frequency. The signal intensity scales with the square of the static electric field strength. Parallel to this process also anti-Stokes radiation by the standard CARS process is generated. Normalization of the IR signal by the CARS signal provides a population independent measurement quantity. Experimental results at various pressures and electric field strengths are presented.

  14. Interactive response of photosynthetic characteristics in Haloxylon ammodendron and Hedysarum scoparium exposed to soil water and air vapor pressure deficits.

    Science.gov (United States)

    Gong, Chunmei; Wang, Jiajia; Hu, Congxia; Wang, Junhui; Ning, Pengbo; Bai, Juan

    2015-08-01

    C4 plants possess better drought tolerance than C3 plants. However, Hedysarum scoparium, a C3 species, is dominant and widely distributed in the desert areas of northwestern China due to its strong drought tolerance. This study compared it with Haloxylon ammodendron, a C4 species, regarding the interactive effects of drought stress and different leaf-air vapor pressure deficits. Variables of interest included gas exchange, the activity levels of key C4 photosynthetic enzymes, and cellular anatomy. In both species, gas exchange parameters were more sensitive to high vapor pressure deficit than to strong water stress, and the net CO2 assimilation rate (An) was enhanced as vapor pressure deficits increased. A close relationship between An and stomatal conductance (gs) suggested that the species shared a similar response mechanism. In H. ammodendron, the activity levels of key C4 enzymes were higher, including those of phosphoenolpyruvate carboxylase (PEPC) and nicotinamide adenine dinucleotide phosphate-malate enzyme (NADP-ME), whereas in H. scoparium, the activity level of nicotinamide adenine dinucleotide-malate enzyme (NAD-ME) was higher. Meanwhile, H. scoparium utilized adaptive structural features, including a larger relative vessel area and a shorter distance from vein to stomata, which facilitated the movement of water. These findings implied that some C4 biochemical pathways were present in H. scoparium to respond to environmental challenges. Copyright © 2015. Published by Elsevier B.V.

  15. DC Flashover Performance of Various Types of Ice-Covered Insulator Strings under Low Air Pressure

    Directory of Open Access Journals (Sweden)

    Lichun Shu

    2012-05-01

    Full Text Available In this study, icing flashover performance tests of typical DC porcelain, glass, and composite insulators are systematically carried out in a multifunction artificial climate chamber. The DC icing flashover voltages of seven typical insulators under various conditions of icing thickness, pollution severity before icing, string length, and atmospheric pressure are obtained. The relationships between icing thickness, salt deposit density as well as atmospheric pressure and the 50% icing flashover voltage are analyzed, and the formulas are obtained by regression method. In addition, the DC icing flashover voltage correction method of typical porcelain, glass, and composite insulator in the coexisting condition of high altitude, contamination, and icing is proposed.

  16. Investigation of Ozone Yield of Air Fed Ozonizer by High Pressure Homogeneous Dielectric Barrier Discharge

    Science.gov (United States)

    2013-07-01

    around 2 ms and 12 ms in this figure, and during the discharge period, the current was continuous without any pulse . Once a discharge generated in...electron avalanches [10]. Fig. 1. High pressure ozone generator. (a) Top view (b) Side view Fig. 2. Barrier discharge device. Table 1... discharge N. Osawa P1 P, UY. Yoshioka UP2 P, R. Hanaoka P1 P 1 Center for Electric, Optic and Energy applications, Department of Electric and

  17. Prediction of electromagnetic pulse generation by picosecond avalanches in high-pressure air

    International Nuclear Information System (INIS)

    Mayhall, D.J.; Yee, J.H.

    1993-01-01

    The gas avalanche switch is a laser-activated, high-voltage switch, consisting of a set of pulse-charged electrodes in a high-pressure gas. Induced electrons from a picosecond-scale laser pulse initiate an avalanche discharge between high-voltage and grounded electrodes. If the voltage, pressure, and dimensions are correct, the rapid avalanche, fueled by the immense number of electrons available in the gas, collapses the applied voltage in picoseconds and generates electromagnetic pulses with widths as short as 1-10 ps and 3 dB bandwidths of 20-120 GHz. With proper voltage or pressure detuning, wider pulses and lower bandwidths occur. In addition to picosecond electromagnetic pulse generation, application of this switch should result in ultra-fast Marx bank pulsers. A number of versions of the switch are possible. The simplest is a parallel plate capacitor, consisting of a gas between two parallel plate conductors. High voltage is applied across the two plates. A parallel plate, Blumlein geometry features a center electrode between two grounded parallel plates. This geometry emits a single pulse in each direction along the parallel plates. A frozen wave geometry with multiple, oppositely charged center electrodes will emit AC pulses. Series switches consisting of gas gaps between two electrodes are also possible

  18. Equilibrium based analytical model for estimation of pressure magnification during deflagration of hydrogen air mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Karanam, Aditya; Sharma, Pavan K.; Ganju, Sunil; Singh, Ram Kumar [Bhabha Atomic Research Centre (BARC), Mumbai (India). Reactor Safety Div.

    2016-12-15

    During postulated accident sequences in nuclear reactors, hydrogen may get released from the core and form a flammable mixture in the surrounding containment structure. Ignition of such mixtures and the subsequent pressure rise are an imminent threat for safe and sustainable operation of nuclear reactors. Methods for evaluating post ignition characteristics are important for determining the design safety margins in such scenarios. This study presents two thermo-chemical models for determining the post ignition state. The first model is based on internal energy balance while the second model uses the concept of element potentials to minimize the free energy of the system with internal energy imposed as a constraint. Predictions from both the models have been compared against published data over a wide range of mixture compositions. Important differences in the regions close to flammability limits and for stoichiometric mixtures have been identified and explained. The equilibrium model has been validated for varied temperatures and pressures representative of initial conditions that may be present in the containment during accidents. Special emphasis has been given to the understanding of the role of dissociation and its effect on equilibrium pressure, temperature and species concentrations.

  19. Analysis of Pressure Losses in Conditioned Air Distribution: Case Study of an Industrial Cafeteria

    OpenAIRE

    John I. Sodiki

    2015-01-01

    Fractions of the total head loss which constitute the loss through duct fittings are calculated for various duct runs in a conditioned air distribution system of a cafeteria building project. An ‘Excel’ plot shows a second order increase of the fraction from 0.70 to 0.76 for an increase in duct length from 6.2m to 22.1m. Also, an average fraction of 0.73 was obtained for an average duct length of 15.8m from the computed values. The study shows that the loss through duct fittings constitutes a...

  20. Recovery of anthocyanins from residues of Rubus fruticosus, Vaccinium myrtillus and Eugenia brasiliensis by ultrasound assisted extraction, pressurized liquid extraction and their combination.

    Science.gov (United States)

    Machado, Ana Paula Da Fonseca; Pereira, Ana Luiza Duarte; Barbero, Gerardo Fernández; Martínez, Julian

    2017-09-15

    This work investigated the extraction efficiency of polyphenols (anthocyanins) from blackberry, blueberry and grumixama residues using combined ultrasonic assisted extraction (UAE) and pressurized liquid extraction (PLE) (UAE+PLE). The performance of UAE+PLE was compared to those achieved by the isolated PLE and UAE methods and conventional Soxhlet extraction. The effects of the extraction methods and solvents (acidified water pH 2.0, ethanol+water 50% v/v and ethanol+water 70% ethanol v/v) on total phenolics content, anthocyanin composition and antioxidant capacity of extracts were investigated by a full factorial design. The extraction efficiency for total phenolics and antioxidant capacity in decreasing order was: UAE+PLE>PLE≈Soxhlet>UAE, and for anthocyanins it was: Soxhlet≈UAE>UAE+PLE>PLE, using hydroethanolic mixtures as solvents. Extractions with acidified water and ultrasound were not effective to recover phenolics. Two, four and fourteen anthocyanins were identified in the extracts from grumixama, blackberry and blueberry, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Korea next generation reactor development; analysis method development of steam condensation and pressure oscillation induced by air and steam condensation in IRWST

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Moo Whan; Lee, Young Yeon; Youn, Deok Hyun; Jo, Dong Woo; Kang, Seok Jae [Pohang University of Science and Technology, Pohang (Korea)

    2002-03-01

    The object of this research is to optimize the design of IRWST installed inside of KNGR through experiment about DCC phenomena. thus, we investigated and analyzed the direct contact condensation of steam and the oscillation of air bubble. And we characterized the pressure oscillation resulting from those. Additionally, the change of pressure at the pool wall during condensation, the variation of temperature of near steam cavity, and the change of steam cavity interface ,using CCD camera, are analyzed. The main experimental parameters were the steam mass flux in the range of 10 400kg/m{sup 2}sec and the subcooled water temperature in the range of 30 90 .deg. C. In the case of air bubble, we measured the frequency of pressure oscillation. Primary pressure of injected air and injection period were in the range of 1 7bar and 0.05 0.3sec, respectively. The experiment result showed results as follows. In chugging region, the pressure pulse generation rate was in the region of low frequency. This can affect adverse effect to IRWST. In the region of condensation oscillation and stable condensation, the variation of frequency of dynamic pressure was decreased with increasing of the water temperature. And decreased as increasing nozzle diameter. The amplitude of pressure oscillation was maximum at the boundary between these two region, and remarkably decreased in the stable condensation region. In the case of air bubble, showed that the frequency of air bubble oscillation decreased with increasing the quantity of injected air. 36 refs., 46 figs., 5 tabs. (Author)

  2. Numerical Modelling of Soot Formation in Laminar Axisymmetric Ethylene-Air Coflow Flames at Atmospheric and Elevated Pressures

    KAUST Repository

    Rakha, Ihsan Allah

    2015-05-01

    The steady coflow diffusion flame is a widely used configuration for studying combustion kinetics, flame dynamics, and pollutant formation. In the current work, a set of diluted ethylene-air coflow flames are simulated to study the formation, growth, and oxidation of soot, with a focus on the effects of pressure on soot yield. Firstly, we assess the ability of a high performance CFD solver, coupled with detailed transport and kinetic models, to reproduce experimental measurements, like the temperature field, the species’ concentrations and the soot volume fraction. Fully coupled conservation equations for mass, momentum, energy, and species mass fractions are solved using a low Mach number formulation. Detailed finite rate chemistry describing the formation of Polycyclic Aromatic Hydrocarbons up to cyclopenta[cd]pyrene is used. Soot is modeled using a moment method and the resulting moment transport equations are solved with a Lagrangian numerical scheme. Numerical and experimental results are compared for various pressures. Reasonable agreement is observed for the flame height, temperature, and the concentrations of various species. In each case, the peak soot volume fraction is predicted along the centerline as observed in the experiments. The predicted integrated soot mass at pressures ranging from 4-8 atm, scales as P2.1, in satisfactory agreement with the measured integrated soot pressure scaling (P2.27). Significant differences in the mole fractions of benzene and PAHs, and the predicted soot volume fractions are found, using two well-validated chemical kinetic mechanisms. At 4 atm, one mechanism over-predicts the peak soot volume fraction by a factor of 5, while the other under-predicts it by a factor of 5. A detailed analysis shows that the fuel tube wall temperature has an effect on flame stabilization.

  3. Real-time monitoring of BTEX in air via ambient-pressure MPI

    Science.gov (United States)

    Swenson, Orven F.; Carriere, Josef P.; Isensee, Harlan; Gillispie, Gregory D.; Cooper, William F.; Dvorak, Michael A.

    1998-05-01

    We have developed and begun to field test a very sensitive method for real-time measurements of single-ring aromatic hydrocarbons in ambient air. In this study, we focus on the efficient 1 + 1 resonance enhanced multiphoton ionization (REMPI) of the BTEX species in the narrow region between 266 and 267 nm. We particularly emphasize 266.7 nm, a wavelength at which both benzene and toluene exhibit a sharp absorbance feature and benzene and its alkylated derivatives all absorb. An optical parametric oscillator system generating 266.7 nm, a REMPI cell, and digital oscilloscope detector are mounted on a breadboard attached to a small cart. In the first field test, the cart was wheeled through the various rooms of a chemistry research complex. Leakage of fuel through the gas caps of cars and light trucks in a parking lot was the subject of the second field test. The same apparatus was also used for a study in which the performance of the REMPI detector and a conventional photoionization detector were compared as a BTEX mixture was eluted by gas chromatography. Among the potential applications of the methodology are on-site analysis of combustion and manufacturing processes, soil gas and water headspace monitoring, space cabin and building air quality, and fuel leak detection.

  4. Air

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  5. Air-assisted liquid–liquid microextraction by solidifying the floating organic droplets for the rapid determination of seven fungicide residues in juice samples

    Energy Technology Data Exchange (ETDEWEB)

    You, Xiangwei [Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101 (China); College of Science, China Agricultural University, Beijing 100193 (China); Xing, Zhuokan [College of Science, China Agricultural University, Beijing 100193 (China); Liu, Fengmao, E-mail: liufengmao@cau.edu.cn [College of Science, China Agricultural University, Beijing 100193 (China); Zhang, Xu [College of Science, China Agricultural University, Beijing 100193 (China)

    2015-05-22

    Highlights: • A novel AALLME-SFO method was firstly reported for pesticide residue analysis. • Solvent with low density and proper melting point was used as extraction solvent. • The formation of “cloudy solvent” with a syringe only. • The new method avoided the use of organic dispersive solvent. - Abstract: A novel air assisted liquid–liquid microextraction using the solidification of a floating organic droplet method (AALLME-SFO) was developed for the rapid and simple determination of seven fungicide residues in juice samples, using the gas chromatography with electron capture detector (GC-ECD). This method combines the advantages of AALLME and dispersive liquid–liquid microextraction based on the solidification of floating organic droplets (DLLME-SFO) for the first time. In this method, a low-density solvent with a melting point near room temperature was used as the extraction solvent, and the emulsion was rapidly formed by pulling in and pushing out the mixture of aqueous sample solution and extraction solvent for ten times repeatedly using a 10-mL glass syringe. After centrifugation, the extractant droplet could be easily collected from the top of the aqueous samples by solidifying it at a temperature lower than the melting point. Under the optimized conditions, good linearities with the correlation coefficients (γ) higher than 0.9959 were obtained and the limits of detection (LOD) varied between 0.02 and 0.25 μg L{sup −1}. The proposed method was applied to determine the target fungicides in juice samples and acceptable recoveries ranged from 72.6% to 114.0% with the relative standard deviations (RSDs) of 2.3–13.0% were achieved. Compared with the conventional DLLME method, the newly proposed method will neither require a highly toxic chlorinated solvent for extraction nor an organic dispersive solvent in the application process; hence, it is more environmentally friendly.

  6. Air-assisted liquid–liquid microextraction by solidifying the floating organic droplets for the rapid determination of seven fungicide residues in juice samples

    International Nuclear Information System (INIS)

    You, Xiangwei; Xing, Zhuokan; Liu, Fengmao; Zhang, Xu

    2015-01-01

    Highlights: • A novel AALLME-SFO method was firstly reported for pesticide residue analysis. • Solvent with low density and proper melting point was used as extraction solvent. • The formation of “cloudy solvent” with a syringe only. • The new method avoided the use of organic dispersive solvent. - Abstract: A novel air assisted liquid–liquid microextraction using the solidification of a floating organic droplet method (AALLME-SFO) was developed for the rapid and simple determination of seven fungicide residues in juice samples, using the gas chromatography with electron capture detector (GC-ECD). This method combines the advantages of AALLME and dispersive liquid–liquid microextraction based on the solidification of floating organic droplets (DLLME-SFO) for the first time. In this method, a low-density solvent with a melting point near room temperature was used as the extraction solvent, and the emulsion was rapidly formed by pulling in and pushing out the mixture of aqueous sample solution and extraction solvent for ten times repeatedly using a 10-mL glass syringe. After centrifugation, the extractant droplet could be easily collected from the top of the aqueous samples by solidifying it at a temperature lower than the melting point. Under the optimized conditions, good linearities with the correlation coefficients (γ) higher than 0.9959 were obtained and the limits of detection (LOD) varied between 0.02 and 0.25 μg L −1 . The proposed method was applied to determine the target fungicides in juice samples and acceptable recoveries ranged from 72.6% to 114.0% with the relative standard deviations (RSDs) of 2.3–13.0% were achieved. Compared with the conventional DLLME method, the newly proposed method will neither require a highly toxic chlorinated solvent for extraction nor an organic dispersive solvent in the application process; hence, it is more environmentally friendly

  7. Pressure relief with visco-elastic foam or with combined static air overlay? A prospective, crossover randomized clinical trial in a dutch nursing home.

    Science.gov (United States)

    van Leen, Martin; Hovius, Steven; Halfens, Ruud; Neyens, Jacques; Schols, Jos

    2013-10-01

    Evidence of the best mattress for preventing pressure ulcers is not conclusive. In a single center, prospective, crossover trial on pressure ulcer incidence in nursing home residents, a static air overlay mattress, without a pump, on top of a visco-elastic foam mattress was compared with a visco-elastic foam mattress alone. The study was performed using a randomized crossover design. Forty-one patients with a score of 19 or lower on the Braden scale, but with no pressure ulcer at the start, were divided into 2 groups; 21 patients received a visco-elastic foam mattress (control group) and 20 patients a static air overlay on top of a visco-elastic foam mattress (intervention group) for a period of 6 months. In the second (crossover) period of 6 months, 19 patients participated in each group. Patients were checked weekly and, only when signs of development of a pressure ulcer were present was treatment altered to reposition patients according to the nursing home pressure ulcer protocol. No statistically significant differences were noted between the 2 groups with regard to age, gender, or Braden scale score. Of 41 patients, 3 died and were unable to participate in the crossover period, 8 patients (22.2%) developed a category 2 or higher pressure ulcer on a visco-elastic foam mattress (control group) and 2 (5.2%) on a static air mattress (intervention group)(P = 0.087). There was a difference regarding pressure ulcer incidence between patients with a very low Braden score between 6 and 12, and patients with a mean score between 13-19. Out of 8 patients, in the 2(25%) who developed a pressure ulcer on a foam mattress, the ulcers showed no signs of healing. In the static air group all pressure ulcers healed by normal treatment according to a standardized pressure ulcer treatment protocol. In this small study, static air overlay mattresses provided a better prevention than visco-elastic foam mattresses alone (5.2% vs 22.2%). The Braden scores of the patients in both

  8. Reliability and Maintainability Analysis of a High Air Pressure Compressor Facility

    Science.gov (United States)

    Safie, Fayssal M.; Ring, Robert W.; Cole, Stuart K.

    2013-01-01

    This paper discusses a Reliability, Availability, and Maintainability (RAM) independent assessment conducted to support the refurbishment of the Compressor Station at the NASA Langley Research Center (LaRC). The paper discusses the methodologies used by the assessment team to derive the repair by replacement (RR) strategies to improve the reliability and availability of the Compressor Station (Ref.1). This includes a RAPTOR simulation model that was used to generate the statistical data analysis needed to derive a 15-year investment plan to support the refurbishment of the facility. To summarize, study results clearly indicate that the air compressors are well past their design life. The major failures of Compressors indicate that significant latent failure causes are present. Given the occurrence of these high-cost failures following compressor overhauls, future major failures should be anticipated if compressors are not replaced. Given the results from the RR analysis, the study team recommended a compressor replacement strategy. Based on the data analysis, the RR strategy will lead to sustainable operations through significant improvements in reliability, availability, and the probability of meeting the air demand with acceptable investment cost that should translate, in the long run, into major cost savings. For example, the probability of meeting air demand improved from 79.7 percent for the Base Case to 97.3 percent. Expressed in terms of a reduction in the probability of failing to meet demand (1 in 5 days to 1 in 37 days), the improvement is about 700 percent. Similarly, compressor replacement improved the operational availability of the facility from 97.5 percent to 99.8 percent. Expressed in terms of a reduction in system unavailability (1 in 40 to 1 in 500), the improvement is better than 1000 percent (an order of magnitude improvement). It is worthy to note that the methodologies, tools, and techniques used in the LaRC study can be used to evaluate

  9. A novel cold atmospheric pressure air plasma jet for peri-implantitis treatment: An in vitro study.

    Science.gov (United States)

    Yang, Yu; Guo, Jinsong; Zhou, Xuan; Liu, Zhiqiang; Wang, Chenbao; Wang, Kaile; Zhang, Jue; Wang, Zuomin

    2018-01-30

    Peri-implantitis is difficult to treat in clinical settings; this is not only because it is a site-specific infectious disease but also because it impedes osseointegration. In this study, a novel cold atmospheric pressure air plasma jet (CAPAJ) was applied to study the treatment of peri-implantitis in vitro. CAPAJ treated the samples for 2, 4 and 6 min, respectively. To evaluate the titanium surface characteristics, the surface elemental composition (X-ray photoelectron spectroscopy [XPS]), roughness and hydrophilicity were evaluated in each group. Concurrently, the sterilization and osseointegration effect of CAPAJ were also examined. Results revealed that after CAPAJ modification, roughness and hydrophilicity of titanium surfaces were significantly increased. Moreover, XPS results demonstrated that the C1s peak was reduced and N1s and O1s peaks were obviously improved. More importantly, CAPAJ showed favorable sterilization and bone formation effects. CAPAJ seemed a simpler and more efficient strategy for the peri-implantitis treatment.

  10. Ultrasound enhanced plasma treatment of glass-fibre-reinforced polyester in atmospheric pressure air for adhesion improvement

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Singh, Shailendra Vikram; Norrman, Kion

    2011-01-01

    damage of the GFRP plates. The polar component of the surface energy of the polyester plate was 21 mJ/m2 before the treatment, increased markedly to 52 mJ/m2 after 2-s plasma treatment without ultrasonic irradiation, and further increased slightly after longer treatments. In addition, the polar component...... that nitrogen-containing functional groups were uniformly attached after the treatments. The roughness of the GFRP surfaces increased after the plasma treatment, but the ultrasonic irradiation did not enhance surface roughening.......A glass-fibre-reinforced polyester (GFRP) plate was treated with dielectric barrier discharge (DBD) at atmospheric pressure in air for adhesion improvement. The effects of ultrasonic irradiation using a high-power gas-jet generator during the treatment were investigated. The optical emission...

  11. The Hydraulic Mechanism in the Orbital Blowout Fracture Because of a High-Pressure Air Gun Injury.

    Science.gov (United States)

    Kang, Seok Joo; Chung, Eui Han

    2015-10-01

    There are 2 predominant mechanisms that are used to explain the pathogenesis of orbital blowout fracture; these include hydraulic and buckling mechanisms. Still, however, its pathophysiology remains uncertain. To date, studies in this series have been conducted using dry skulls, cadavers, or animals. But few clinical studies have been conducted to examine whether the hydraulic mechanism is involved in the occurrence of pure orbital blowout fracture. The authors experienced a case of a 52-year-old man who had a pure medial blowout fracture after sustaining an eye injury because of a high-pressure air gun. Our case suggests that surgeons should be aware of the possibility that the hydraulic mechanism might be involved in the blowout fracture in patients presenting with complications, such as limitation of eye movement, diplopia, and enophthalmos.

  12. The influence of a low air pressure environment on human metabolic rate during short-term (< 2 h) exposures.

    Science.gov (United States)

    Cui, W; Wang, H; Wu, T; Ouyang, Q; Hu, S; Zhu, Y

    2017-03-01

    Passengers in aircraft cabins are exposed to low-pressure environments. One of the missing links in the research on thermal comfort under cabin conditions is the influence of low air pressure on the metabolic rate. In this research, we simulated the cabin pressure regime in a chamber in which the pressure level could be controlled. Three pressure levels (101/85/70 kPa) were tested to investigate how metabolic rate changed at different pressure levels. The results show that as pressure decreased, the respiratory flow rate (RFR) at standard condition (STPD: 0°C, 101 kPa) significantly decreased. Yet the oxygen (O 2 ) consumption and carbon dioxide (CO 2 ) production significantly increased, as reflected in the larger concentration difference between inhaled and exhaled air. A significant increase in the respiratory quotient (RQ) was also observed. For metabolic rate, no significant increase (P > 0.05) was detected when pressure decreased from 101 kPa to 85 kPa; however, the increase associated with a pressure decrease from 85 kPa to 70kPa was significant (P < 0.05). Empirical equations describing the above parameters are provided, which can be helpful for thermal comfort assessment in short-haul flights. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Thin Air Resulting in High Pressure: Mountain Sickness and Hypoxia-Induced Pulmonary Hypertension

    Science.gov (United States)

    Richter, Manuel; Tello, Khodr; Sommer, Natascha; Gall, Henning; Ghofrani, Hossein Ardeschir

    2017-01-01

    With rising altitude the partial pressure of oxygen falls. This phenomenon leads to hypobaric hypoxia at high altitude. Since more than 140 million people permanently live at heights above 2500 m and more than 35 million travel to these heights each year, understanding the mechanisms resulting in acute or chronic maladaptation of the human body to these circumstances is crucial. This review summarizes current knowledge of the body's acute response to these circumstances, possible complications and their treatment, and health care issues resulting from long-term exposure to high altitude. It furthermore describes the characteristic mechanisms of adaptation to life in hypobaric hypoxia expressed by the three major ethnic groups permanently dwelling at high altitude. We additionally summarize current knowledge regarding possible treatment options for hypoxia-induced pulmonary hypertension by reviewing in vitro, rodent, and human studies in this area of research. PMID:28522921

  14. A switchable positive and negative air pressure device for efficient and gentle handling of nanofiber scaffolds

    Science.gov (United States)

    Hotaling, Nathan A.; Khristov, Vladimir; Maminishkis, Arvydas; Bharti, Kapil; Simon, Carl G.

    2017-10-01

    A scaffold handling device (SHD) has been designed that can switch from gentle suction to positive pressure to lift and place nanofiber scaffolds. In tissue engineering laboratories, delicate fibrous scaffolds, such as electrospun nanofiber scaffolds, are often used as substrates for cell culture. Typical scaffold handling procedures include lifting the scaffolds, moving them from one container to another, sterilization, and loading scaffolds into cell culture plates. Using tweezers to handle the scaffolds can be slow, can damage the scaffolds, and can cause them to wrinkle or fold. Scaffolds may also acquire a static charge which makes them difficult to put down as they cling to tweezers. An SHD has been designed that enables more efficient, gentle lifting, and placement of delicate scaffolds. Most of the parts to make the SHD can be purchased, except for the tip which can be 3D-printed. The SHD enables more reliable handling of nanofiber scaffolds that may improve the consistency of biomanufacturing processes.

  15. Atmospheric Pressure Corrections in Geodesy and Oceanography: a Strategy for Handling Air Tides

    Science.gov (United States)

    Ponte, Rui M.; Ray, Richard D.

    2003-01-01

    Global pressure data are often needed for processing or interpreting modern geodetic and oceanographic measurements. The most common source of these data is the analysis or reanalysis products of various meteorological centers. Tidal signals in these products can be problematic for several reasons, including potentially aliased sampling of the semidiurnal solar tide as well as the presence of various modeling or timing errors. Building on the work of Van den Dool and colleagues, we lay out a strategy for handling atmospheric tides in (re)analysis data. The procedure also offers a method to account for ocean loading corrections in satellite altimeter data that are consistent with standard ocean-tide corrections. The proposed strategy has immediate application to the on-going Jason-1 and GRACE satellite missions.

  16. Magnetic Ignition of Pulsed Gas Discharges in Air of Low Pressure in a Coaxial Plasma Gun

    Science.gov (United States)

    Thom, Karlheinz; Norwood, Joseph, Jr.

    1961-01-01

    The effect of an axial magnetic field on the breakdown voltage of a coaxial system of electrodes has been investigated by earlier workers. For low values of gas pressure times electrode spacing, the breakdown voltage is decreased by the application of the magnetic field. The electron cyclotron radius now assumes the role held by the mean free path in nonmagnetic discharges and the breakdown voltage becomes a function of the magnetic flux density. In this paper the dependence of the formative time lag as a function of the magnetic flux density is established and the feasibility of using a magnetic field for igniting high-voltage, high-current discharges is shown through theory and experiment. With a 36 microfarad capacitor bank charged to 48,000 volts, a peak current of 1.3 x 10( exp 6) amperes in a coaxial type of plasma gun was achieved with a current rise time of only 2 microseconds.

  17. Novel atmospheric pressure plasma device releasing atomic hydrogen: reduction of microbial-contaminants and OH radicals in the air

    International Nuclear Information System (INIS)

    Nojima, Hideo; Park, Rae-Eun; Kwon, Jun-Hyoun; Suh, Inseon; Jeon, Junsang; Ha, Eunju; On, Hyeon-Ki; Kim, Hye-Ryung; Choi, KyoungHui; Lee, Kwang-Hee; Seong, Baik-Lin; Jung, Hoon; Kang, Shin Jung; Namba, Shinichi; Takiyama, Ken

    2007-01-01

    A novel atmospheric pressure plasma device releasing atomic hydrogen has been developed. This device has specific properties such as (1) deactivation of airborne microbial-contaminants, (2) neutralization of indoor OH radicals and (3) being harmless to the human body. It consists of a ceramic plate as a positive ion generation electrode and a needle-shaped electrode as an electron emission electrode. Release of atomic hydrogen from the device has been investigated by the spectroscopic method. Optical emission of atomic hydrogen probably due to recombination of positive ions, H + (H 2 O)n, generated from the ceramic plate electrode and electrons emitted from the needle-shaped electrode have been clearly observed in the He gas (including water vapour) environment. The efficacy of the device to reduce airborne concentrations of influenza virus, bacteria, mould fungi and allergens has been evaluated. 99.6% of airborne influenza virus has been deactivated with the operation of the device compared with the control test in a 1 m 3 chamber after 60 min. The neutralization of the OH radical has been investigated by spectroscopic and biological methods. A remarkable reduction of the OH radical in the air by operation of the device has been observed by laser-induced fluorescence spectroscopy. The cell protection effects of the device against OH radicals in the air have been observed. Furthermore, the side effects have been checked by animal experiments. The harmlessness of the device has been confirmed

  18. Cellular attachment and differentiation on titania nanotubes exposed to air- or nitrogen-based non-thermal atmospheric pressure plasma.

    Science.gov (United States)

    Seo, Hye Yeon; Kwon, Jae-Sung; Choi, Yu-Ri; Kim, Kwang-Mahn; Choi, Eun Ha; Kim, Kyoung-Nam

    2014-01-01

    The surface topography and chemistry of titanium implants are important factors for successful osseointegration. However, chemical modification of an implant surface using currently available methods often results in the disruption of topographical features and the loss of beneficial effects during the shelf life of the implant. Therefore, the aim of this study was to apply the recently highlighted portable non-thermal atmospheric pressure plasma jet (NTAPPJ), elicited from one of two different gas sources (nitrogen and air), to TiO2 nanotube surfaces to further improve their osteogenic properties while preserving the topographical morphology. The surface treatment was performed before implantation to avoid age-related decay. The surface chemistry and morphology of the TiO2 nanotube surfaces before and after the NTAPPJ treatment were determined using a field-emission scanning electron microscope, a surface profiler, a contact angle goniometer, and an X-ray photoelectron spectroscope. The MC3T3-E1 cell viability, attachment and morphology were confirmed using calcein AM and ethidium homodimer-1 staining, and analysis of gene expression using rat mesenchymal stem cells was performed using a real-time reverse-transcription polymerase chain reaction. The results indicated that both portable nitrogen- and air-based NTAPPJ could be used on TiO2 nanotube surfaces easily and without topographical disruption. NTAPPJ resulted in a significant increase in the hydrophilicity of the surfaces as well as changes in the surface chemistry, which consequently increased the cell viability, attachment and differentiation compared with the control samples. The nitrogen-based NTAPPJ treatment group exhibited a higher osteogenic gene expression level than the air-based NTAPPJ treatment group due to the lower atomic percentage of carbon on the surface that resulted from treatment. It was concluded that NTAPPJ treatment of TiO2 nanotube surfaces results in an increase in cellular activity

  19. Cellular attachment and differentiation on titania nanotubes exposed to air- or nitrogen-based non-thermal atmospheric pressure plasma.

    Directory of Open Access Journals (Sweden)

    Hye Yeon Seo

    Full Text Available The surface topography and chemistry of titanium implants are important factors for successful osseointegration. However, chemical modification of an implant surface using currently available methods often results in the disruption of topographical features and the loss of beneficial effects during the shelf life of the implant. Therefore, the aim of this study was to apply the recently highlighted portable non-thermal atmospheric pressure plasma jet (NTAPPJ, elicited from one of two different gas sources (nitrogen and air, to TiO2 nanotube surfaces to further improve their osteogenic properties while preserving the topographical morphology. The surface treatment was performed before implantation to avoid age-related decay. The surface chemistry and morphology of the TiO2 nanotube surfaces before and after the NTAPPJ treatment were determined using a field-emission scanning electron microscope, a surface profiler, a contact angle goniometer, and an X-ray photoelectron spectroscope. The MC3T3-E1 cell viability, attachment and morphology were confirmed using calcein AM and ethidium homodimer-1 staining, and analysis of gene expression using rat mesenchymal stem cells was performed using a real-time reverse-transcription polymerase chain reaction. The results indicated that both portable nitrogen- and air-based NTAPPJ could be used on TiO2 nanotube surfaces easily and without topographical disruption. NTAPPJ resulted in a significant increase in the hydrophilicity of the surfaces as well as changes in the surface chemistry, which consequently increased the cell viability, attachment and differentiation compared with the control samples. The nitrogen-based NTAPPJ treatment group exhibited a higher osteogenic gene expression level than the air-based NTAPPJ treatment group due to the lower atomic percentage of carbon on the surface that resulted from treatment. It was concluded that NTAPPJ treatment of TiO2 nanotube surfaces results in an increase in

  20. Measured air overpressures, soil-particle pressures, and slumps during the pre-ASIAGO U2Ar stemming experiment

    Energy Technology Data Exchange (ETDEWEB)

    Freynik, H.S. Jr.; Roach, D.R.; Dittbenner, G.R.

    1978-01-04

    On November 15, 1976, Lawrence Livermore Laboratory completed its first comprehensive stemming experiment for measuring downhole parameters while varying fill material and rate. Stemming can be defined as backfilling a hole in which a device has been placed to prevent leakage of radioactive materials or gases to the surface. A computer code is being developed for stemming operations, and this experiment was designed to measure parameters under different stemming conditions so the code could be verified and modified. The experiment was conducted in the lower half of a steel-cased, 4-ft-diam, 2000-ft-deep hole at Nevada Test Site. The two stemming materials used in the experiment, Overton sand and LLL II mix, were tested at three fill rates. Significant results of this experiment included successful measurement of downhole air overpressures, vertical and horizontal soil-particle pressures, and temperature. Vertical soil-particle pressures were higher than expected. All surface measurements were valid. The slump-displacement measurements system provided a timing mark to indicate the occurrence of a slump. A major slump occurred on the third day of stemming; a minor slump occurred on the fourth day.

  1. Characteristics and metal leachability of incinerated sewage sludge ash and air pollution control residues from Hong Kong evaluated by different methods.

    Science.gov (United States)

    Li, Jiang-Shan; Xue, Qiang; Fang, Le; Poon, Chi Sun

    2017-06-01

    The improper disposal of incinerated sewage sludge ash (ISSA) and air pollution control residues (APCR) from sewage sludge incinerators has become an environmental concern. The physicochemical, morphological and mineralogical characteristics of ISSA and APCR from Hong Kong, and the leachability and risk of heavy metals, are presented in this paper. The results showed that a low hydraulic and pozzolanic potential was associated with the ISSA and APCR due to the presence of low contents of SiO 2 , Al 2 O 3 and CaO and high contents of P, S and Cl (especially for APCR). Although high concentrations of Zn and Cu (especially for ISSA) followed by Ni, Pb and As, Se were detected, a low leaching rate of these metals (especially at neutral and alkaline pH) rendered them classifiable as non-hazardous according to the U.S. EPA and Chinese national regulatory limits. The leached metals concentrations from ISSA and APCR were mainly pH dependent, and metals solubilization occurred mainly at low pH. Different leaching tests should be adopted based on the simulated different environmental conditions and exposure scenarios for assessing the leachability as contrasting results could be obtained due to the differences in complexing abilities and final pH of the leaching solutions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Studies of air, water, and ethanol vapor atmospheric pressure plasmas for antimicrobial applications.

    Science.gov (United States)

    Ferrell, James R; Bogovich, Erinn R; Lee, Nicholas R; Gray, Robert L; Pappas, Daphne D

    2015-06-25

    The generation of air-based plasmas under atmospheric plasma conditions was studied to assess their antimicrobial efficacy against commonly found pathogenic bacteria. The mixture of initial gases supplied to the plasma was found to be critical for the formation of bactericidal actives. The optimal gas ratio for bactericidal effect was determined to be 99% nitrogen and 1% oxygen, which led to a 99.999% reduction of a pathogenic strain of Escherichia coli on stainless steel surfaces. The experimental substrate, soil load on the substrate, flow rate of the gases, and addition of ethanol vapor all were found to affect antimicrobial efficacy of studied plasmas. Optical emission spectroscopy was used to identify the species that were present in the plasma bulk phase for multiple concentrations of nitrogen and oxygen ratios. The collected spectra indicate a unique series of bands present in the ultraviolet region of the electromagnetic spectrum that can be attributed to nitric oxide species known to be highly antimicrobial. This intense spectral profile dramatically changes as the concentration of nitrogen decreases.

  3. Effect of aviation fuel type and fuel injection conditions on the spray characteristics of pressure swirl and hybrid air blast fuel injectors

    Science.gov (United States)

    Feddema, Rick

    Feddema, Rick T. M.S.M.E., Purdue University, December 2013. Effect of Aviation Fuel Type and Fuel Injection Conditions on the Spray Characteristics of Pressure Swirl and Hybrid Air Blast Fuel Injectors. Major Professor: Dr. Paul E. Sojka, School of Mechanical Engineering Spray performance of pressure swirl and hybrid air blast fuel injectors are central to combustion stability, combustor heat management, and pollutant formation in aviation gas turbine engines. Next generation aviation gas turbine engines will optimize spray atomization characteristics of the fuel injector in order to achieve engine efficiency and emissions requirements. Fuel injector spray atomization performance is affected by the type of fuel injector, fuel liquid properties, fuel injection pressure, fuel injection temperature, and ambient pressure. Performance of pressure swirl atomizer and hybrid air blast nozzle type fuel injectors are compared in this study. Aviation jet fuels, JP-8, Jet A, JP-5, and JP-10 and their effect on fuel injector performance is investigated. Fuel injector set conditions involving fuel injector pressure, fuel temperature and ambient pressure are varied in order to compare each fuel type. One objective of this thesis is to contribute spray patternation measurements to the body of existing drop size data in the literature. Fuel droplet size tends to increase with decreasing fuel injection pressure, decreasing fuel injection temperature and increasing ambient injection pressure. The differences between fuel types at particular set conditions occur due to differences in liquid properties between fuels. Liquid viscosity and surface tension are identified to be fuel-specific properties that affect the drop size of the fuel. An open aspect of current research that this paper addresses is how much the type of aviation jet fuel affects spray atomization characteristics. Conventional aviation fuel specifications are becoming more important with new interest in alternative

  4. Suture Technique to Prevent Air Leakage during Negative-Pressure Wound Therapy in Fournier Gangrene.

    Science.gov (United States)

    Chang, Feng-Shu; Chou, Chieh; Hu, Chuan-Yu; Huang, Shu-Hung

    2018-01-01

    The use of negative-pressure wound therapy (NPWT) for Fournier gangrene management is well documented; however, it is difficult to fixate GranuFoam dressings and maintain an airtight seal over the perineum area. We developed a simple method to facilitate GranuFoam fixation and improve airtight sealing. The Fournier's gangrene severity index (FGSI) score less than 9 was collected in from January 2015 to October 2016. All 13 patients underwent fasciotomy, and NPWT was applied directly on fasciotomy wounds after the debridement of infected tissue. Partial wound closure was performed, and a portion of GranuFoam was inserted to facilitate fixation. The seal check was converted to a 0-10 scale score that was recorded every 4 hours during NPWT. Patient profiles including medical history, FGSI, method of wound closure, and length of stay were collected in this study. The median age of the patients was 62 (38-76) years. The mean FGSI score was 4.3 ± 3.1. The average duration of NPWT was 17.5 ± 11.5 days, and the average seal check score was 0.8 ± 0.5. No seal check alarms were noted during the study. Successful wound closure was achieved in all patients without using additional reconstruction methods such as skin grafting or muscle flap coverage. The present results suggest that partial wound-edge closure and in situ GranuFoam fixation improve the NPWT leaks in Fournier gangrene wounds. Furthermore, this method is simple to learn and can be useful in applying NPWT to anatomically difficult areas.

  5. A comparative pressure analysis of air flow between horizontal and V-Tail of UAV MALE of NACA0012H with speed variation

    Directory of Open Access Journals (Sweden)

    Riza Rahmat

    2018-01-01

    Full Text Available NACA0012H is an airfoil type that could be used for Unmanned Aerial Vehicle Medium Altitude Long Endurance. This experiment was used to analyze stress in the surface of Tail of UAV MALE that was caused by air flow. The experiment was conducted using Computational Fluid Dynamics Software. Two designs of tail, horizontal and V-tail, were considered to simulate pressure occurred on the surface of leading edge, chamber and trailing edge. The simulation was developed varying the speed of the UAV MALE. The results showed that pressure occurred on the surface of horizontal tail higher than pressure on the V-tail.

  6. Associations between Long-Term Air Pollutant Exposures and Blood Pressure in Elderly Residents of Taipei City: A Cross-Sectional Study

    NARCIS (Netherlands)

    Chen, Szu-Ying; Wu, Chang-Fu; Lee, Jui-Huan; Hoffmann, Barbara; Peters, Annette; Brunekreef, Bert; Chu, Da-Chen; Chan, Chang-Chuan

    BACKGROUND: Limited information is available regarding long-term effects of air pollution on blood pressure (BP) and hypertension. OBJECTIVE: We studied whether 1-year exposures to particulate matter (PM) and nitrogen oxides (NOx) were correlated with BP and hypertension in the elderly. METHODS: We

  7. High intensity interior aircraft noise increases the risk of high diastolic blood pressure in Indonesian Air Force pilots

    Directory of Open Access Journals (Sweden)

    Minarma Siagian

    2009-12-01

    Full Text Available Aim: To analyze the effects of aircraft noise, resting pulse rate, and other factors on the risk of high diastolic blood pressure (DBP in Indonesian Air Force pilots.Methods: A nested case-control study was conducted using data extracted from annual medical check-ups indoctrination aerophysiologic training records at the Saryanto Aviation and Aerospace Health Institute (LAKESPRA in Jakarta from January 2003 – September 2008. For analysis of DBP: the case group with DBP ≥ 90 mmHg were compared with contral group with DBP < 79 mmHG. One case matched to 12 controls.Results: Out of 567 pilots, 544 (95.9% had complete medical records. For this analysis there were 40 cases of high DBP and 480 controls for DBP. Pilots exposed to aircraft noise 90-95 dB rather than 70-80 dB had a 2.7-fold increase for high DBP [adjusted odds ratio (ORa = 2.70; 95% confi dence interval (CI = 1.05-6.97]. Pilots with resting pulse rates of ≥ 81/minute rather than ≤ 80/minute had a 2.7-fold increase for high DBP (ORa = 2.66; 95% CI = 1.26-5.61. In terms of total fl ight hours, pilots who had 1401-11125 hours rather than 147-1400 hours had a 3.2-fold increase for high DBP (ORa = 3.18; 95% CI = 1.01-10.03.Conclusion: High interior aircraft noise, high total flight hours,  and high resting pulse rate, increased risk for high DBP. Self assessment of resting pulse rate can be used to control the risk of high DBP. (Med J Indones 2009; 276: 276-82Keywords: diastolic blood pressure, aircraft noise, resting pulse rate, military pilots

  8. On the physical processes ruling an atmospheric pressure air glow discharge operating in an intermediate current regime

    Energy Technology Data Exchange (ETDEWEB)

    Prevosto, L., E-mail: prevosto@waycom.com.ar; Mancinelli, B.; Chamorro, J. C.; Cejas, E. [Grupo de Descargas Eléctricas, Departamento Ing. Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto (2600), Santa Fe (Argentina); Kelly, H. [Grupo de Descargas Eléctricas, Departamento Ing. Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651, Venado Tuerto (2600), Santa Fe (Argentina); Instituto de Física del Plasma (CONICET), Facultad de Ciencias Exactas y Naturales (UBA) Ciudad Universitaria Pab. I, 1428, Buenos Aires (Argentina)

    2015-02-15

    Low-frequency (100 Hz), intermediate-current (50 to 200 mA) glow discharges were experimentally investigated in atmospheric pressure air between blunt copper electrodes. Voltage–current characteristics and images of the discharge for different inter-electrode distances are reported. A cathode-fall voltage close to 360 V and a current density at the cathode surface of about 11 A/cm{sup 2}, both independent of the discharge current, were found. The visible emissive structure of the discharge resembles to that of a typical low-pressure glow, thus suggesting a glow-like electric field distribution in the discharge. A kinetic model for the discharge ionization processes is also presented with the aim of identifying the main physical processes ruling the discharge behavior. The numerical results indicate the presence of a non-equilibrium plasma with rather high gas temperature (above 4000 K) leading to the production of components such as NO, O, and N which are usually absent in low-current glows. Hence, the ionization by electron-impact is replaced by associative ionization, which is independent of the reduced electric field. This leads to a negative current-voltage characteristic curve, in spite of the glow-like features of the discharge. On the other hand, several estimations show that the discharge seems to be stabilized by heat conduction; being thermally stable due to its reduced size. All the quoted results indicate that although this discharge regime might be considered to be close to an arc, it is still a glow discharge as demonstrated by its overall properties, supported also by the presence of thermal non-equilibrium.

  9. Study of nanosecond discharges in H2-air mixtures at atmospheric pressure for plasma assisted combustion applications

    Science.gov (United States)

    Kobayashi, Sumire; Bonaventura, Zdeněk; Tholin, Fabien; Popov, Nikolay A.; Bourdon, Anne

    2017-07-01

    This paper presents 2D simulations of nanosecond discharges between two point electrodes for four different H2-air mixtures defined by their equivalence ratios ϕ (i.e. φ =0, air, φ =0.3, lean mixture, φ =1, stoichiometric mixture and φ =1.5, rich mixture) at atmospheric pressure and at an initial temperature of 1000 K. In a first step, we have shown that the mixture composition has only a very small influence on the discharge dynamics and structure during the streamer phase and up to the formation of the plasma channel between the two point electrodes in H2-air mixtures with φ \\in [0,1.5]. However, as the plasma channel is formed slightly earlier as the equivalence ratio increases, for a given voltage pulse, the duration of the nanosecond spark phase increases as the equivalence ratio increases. As expected, we have shown that excited states of N2 (and in particular N2(A)) and radicals (and in particular O(D), O(P), H and OH) are very efficiently produced during the voltage pulse after the start of the spark phase. After the voltage pulse, and up to 100 ns, the densities of excited states of N2 and of O(D) decrease. Conversely, most of the O(P), H and OH radicals are produced after the voltage pulse due to the dissociative quenching of electronically excited N2. As for radicals, the gas temperature starts increasing after the start of the spark phase. For all studied mixtures, the density of O(P) atoms and the gas temperature reach their maxima after the end of the voltage pulse and the densities of O(P), H and OH radicals and the maximal gas temperature increase as the equivalence ratio increases. We have shown that the production of radicals is the highest on the discharge axis and the distribution of species after the voltage pulse and up to 100 ns has a larger diameter between the electrodes than close to both electrode tips. As for species, the temperature distribution presents two hot spots close to the point electrode tips. The non

  10. IMPACT OF COMPRESSED AIR PRESSURE ON GEOMETRIC STRUCTURE OF AISI 1045 STEEL SURFACE AFTER TURNING WITH THE USE OF MQCL METHOD

    Directory of Open Access Journals (Sweden)

    Radoslaw Wojciech Maruda

    2016-06-01

    Full Text Available MQL (Minimum Quantity Lubrication and MQCL (Minimum Quantity Cooling Lubrication methods become alternative solutions for dry machining and deluge cooling conditions. Due to a growing interest in MQCL method, this article discusses the impact of compressed air pressure, which is one of the basic parameters of generating emulsion mist used in MQCL method, on the geometric structure of the surface after turning AISI 1045 carbon steel. This paper presents the results of measurements of machined surface roughness parameters Ra, Rz, RSm as well as roughness profiles and Abbot-Firestone curves. It was found that the increase in the compressed air pressure from 1 to 7 MPa causes an increase in the roughness of the machined surface (the lowest values were obtained at a pressure of 1 MPa. An increase of emulsion mass flow rate also causes an increase in the value of selected parameters of roughness of the machined surface.

  11. Numerical Analysis on the Influence of Thermal Effects on Oil Flow Characteristic in High-Pressure Air Injection (HPAI Process

    Directory of Open Access Journals (Sweden)

    Hu Jia

    2012-01-01

    Full Text Available In previous laboratory study, we have shown the thermal behavior of Keke Ya light crude oil (Tarim oilfield, branch of CNPC for high-pressure air injection (HPAI application potential study. To clarify the influences of thermal effects on oil production, in this paper, we derived a mathematical model for calculating oil flow rate, which is based on the heat conduction property in porous media from the combustion tube experiment. Based on remarkably limited knowledge consisting of very global balance arguments and disregarding all the details of the mechanisms in the reaction zone, the local governing equations are formulated in a dimensionless form. We use finite difference method to solve this model and address the study by way of qualitative analysis. The time-space dimensionless oil flow rate (qD profiles are established for comprehensive studies on the oil flow rate characteristic affected by thermal effects. It also discusses how these findings will impact HPAI project performances, and several guidelines are suggested.

  12. A comparison of ground and satellite observations of cloud cover to saturation pressure differences during a cold air outbreak

    Energy Technology Data Exchange (ETDEWEB)

    Alliss, R.J.; Raman, S. [North Carolina State Univ., Raleigh, NC (United States)

    1996-04-01

    The role of clouds in the atmospheric general circulation and the global climate is twofold. First, clouds owe their origin to large-scale dynamical forcing, radiative cooling in the atmosphere, and turbulent transfer at the surface. In addition, they provide one of the most important mechanisms for the vertical redistribution of momentum and sensible and latent heat for the large scale, and they influence the coupling between the atmosphere and the surface as well as the radiative and dynamical-hydrological balance. In existing diagnostic cloudiness parameterization schemes, relative humidity is the most frequently used variable for estimating total cloud amount or stratiform cloud amount. However, the prediction of relative humidity in general circulation models (GCMs) is usually poor. Even for the most comprehensive GCMs, the predicted relative humidity may deviate greatly from that observed, as far as the frequency distribution of relative humidity is concerned. Recently, there has been an increased effort to improve the representation of clouds and cloud-radiation feedback in GCMs, but the verification of cloudiness parameterization schemes remains a severe problem because of the lack of observational data sets. In this study, saturation pressure differences (as opposed to relative humidity) and satellite-derived cloud heights and amounts are compared with ground determinations of cloud cover over the Gulf Stream Locale (GSL) during a cold air outbreak.

  13. Transitions between corona, glow, and spark regimes of nanosecond repetitively pulsed discharges in air at atmospheric pressure

    Science.gov (United States)

    Pai, David Z.; Lacoste, Deanna A.; Laux, Christophe O.

    2010-05-01

    In atmospheric pressure air preheated from 300 to 1000 K, the nanosecond repetitively pulsed (NRP) method has been used to generate corona, glow, and spark discharges. Experiments have been performed to determine the parameter space (applied voltage, pulse repetition frequency, ambient gas temperature, and interelectrode gap distance) of each discharge regime. In particular, the experimental conditions necessary for the glow regime of NRP discharges have been determined, with the notable result that there exists a minimum and maximum gap distance for its existence at a given ambient gas temperature. The minimum gap distance increases with decreasing gas temperature, whereas the maximum does not vary appreciably. To explain the experimental results, an analytical model is developed to explain the corona-to-glow (C-G) and glow-to-spark (G-S) transitions. The C-G transition is analyzed in terms of the avalanche-to-streamer transition and the breakdown field during the conduction phase following the establishment of a conducting channel across the discharge gap. The G-S transition is determined by the thermal ionization instability, and we show analytically that this transition occurs at a certain reduced electric field for the NRP discharges studied here. This model shows that the electrode geometry plays an important role in the existence of the NRP glow regime at a given gas temperature. We derive a criterion for the existence of the NRP glow regime as a function of the ambient gas temperature, pulse repetition frequency, electrode radius of curvature, and interelectrode gap distance.

  14. Surface kinetics for catalytic combustion of hydrogen-air mixtures on platinum at atmospheric pressure in stagnation flows

    Science.gov (United States)

    Ikeda, H.; Sato, J.; Williams, F. A.

    1995-03-01

    Experimental studies of the combustion of premixed hydrogen-air mixtures impinging on the surface of a heated platinum plate at normal atmospheric pressure were performed and employed to draw inferences concerning surface reaction mechanisms and rate parameters applicable under practical conditions of catalytic combustion. Plate and gas temperatures were measured by thermocouples, and concentration profiles of major stable species in the gas were measured by gas-chromatographic analyses of samples withdrawn by quartz probes. In addition, ignition and extinction phenomena were recorded and interpreted with the aid of a heat balance at the surface and a previous flow-field analysis of the stagnation-point boundary layer. From the experimental and theoretical results, conclusions were drawn concerning the surface chemical-kinetic mechanisms and values of the elementary rate parameters that are consistent with the observations. In particular, the activation energy for the surface oxidation step H + OH → H 2O is found to be appreciably less at these high surface coverages than in the low-coverage limit.

  15. Influence of pulsed nanosecond volume discharge in atmospheric-pressure air on the electrical characteristics of MCT epitaxial films

    Science.gov (United States)

    Grigoryev, Denis V.; Voitsekhovskii, Alexandr V.; Lozovoy, Kirill A.; Nesmelov, Sergey N.; Dzyadukh, Stanislav M.; Tarasenko, Viktor F.; Shulepov, Michail A.; Dvoretskii, Sergei A.

    2015-12-01

    The purpose of this paper was investigating the effect of volume nanosecond discharge in air at atmospheric pressure on the electro-physical properties of the HgCdTe (MCT) epitaxial films grown by molecular beam epitaxy. Hall measurements of electro-physical parameters of MCT samples after irradiation have shown that there is a layer of epitaxial films exhibiting n-type conductivity that is formed in the near-surface area. After more than 600 pulses of influence parameters and thickness of the resulting n-layer is such that the measured field dependence of Hall coefficient corresponds to the material of n-type conductivity. Also it is shown that the impact of the discharge leads to significant changes in electro-physical characteristics of MIS structures. This fact is demonstrated by increase in density of positive fixed charge, change in the hysteresis type of the capacitance-voltage characteristic, an increase in density of surface states. The preliminary results show that it is possible to use such actions in the development of technologies of the controlled change in the properties of MCT.

  16. OH density measured by PLIF in a nanosecond atmospheric pressure diffuse discharge in humid air under steep high voltage pulses

    Science.gov (United States)

    Ouaras, K.; Magne, L.; Pasquiers, S.; Tardiveau, P.; Jeanney, P.; Bournonville, B.

    2018-04-01

    The spatiotemporal distributions of the OH radical density are measured using planar laser induced fluorescence in the afterglow of a nanosecond diffuse discharge at atmospheric pressure in humid air. The diffuse discharge is generated between a pin and a grounded plate electrodes within a gap of 18 mm. The high voltage pulse applied to the pin ranges from 65 to 85 kV with a rise time of 2 ns. The specific electrical energy transferred to the gas ranges from 5 to 40 J l‑1. The influence of H2O concentration is studied from 0.5% to 1.5%. An absolute calibration of OH density is performed using a six-level transient rate equation model to simulate the dynamics of OH excitation by the laser, taking into account collisional processes during the optical pumping and the fluorescence. Rayleigh scattering measurements are used to achieve the geometrical part of the calibration. A local maximum of OH density is found in the pin area whatever the operating conditions. For 85 kV and 1% of H2O, this peak reaches a value of 2.0 × 1016 cm‑3 corresponding to 8% of H2O dissociation. The temporal decay of the spatially averaged OH density is found to be similar as in the afterglow of a homogeneous photo-triggered discharge for which a self-consistent modeling is done. These tools are then used to bring discussion elements on OH kinetics.

  17. Simulation Analysis of Sludge Disposal and Volatile Fatty Acids Production from Gravity Pressure Reactor via Wet Air Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Gwon Woo [Biomass and Waste Energy Laboratory, KIER, Daejeon (Korea, Republic of); Seo, Tae Wan; Lee, Hong-Cheol; Hwang, In-Ju [Environmental and Plant Engineering Research Institute, KICT, Goyang (Korea, Republic of)

    2016-04-15

    Efficacious wastewater treatment is essential for increasing sewage sludge volume and implementing strict environmental regulations. The operation cost of sludge treatment amounts up to 50% of the total costs for wastewater treatment plants, therefore, an economical sludge destruction method is crucially needed. Amid several destruction methods, wet air oxidation (WAO) can efficiently treat wastewater containing organic pollutants. It can be used not only for sludge destruction but also for useful by-product production. Volatile fatty acids (VFAs), one of many byproducts, is considered to be an important precursor of biofuel and chemical materials. Its high reaction condition has instituted the study of gravity pressure reactor (GPR) for an economical process of WAO to reduce operation cost. Simulation of subcritical condition was conducted using Aspen Plus with predictive Soave-Redlich-Kwong (PSRK) equation of state. Conjointly, simulation analysis for GPR depth, oxidizer type, sludge flow rate and oxidizer injection position was carried out. At GPR depth of 1000m and flow rate of 2 ton/h, the conversion and yield of VFAs were 92.02% and 0.17g/g, respectively.

  18. Simulation Analysis of Sludge Disposal and Volatile Fatty Acids Production from Gravity Pressure Reactor via Wet Air Oxidation

    International Nuclear Information System (INIS)

    Park, Gwon Woo; Seo, Tae Wan; Lee, Hong-Cheol; Hwang, In-Ju

    2016-01-01

    Efficacious wastewater treatment is essential for increasing sewage sludge volume and implementing strict environmental regulations. The operation cost of sludge treatment amounts up to 50% of the total costs for wastewater treatment plants, therefore, an economical sludge destruction method is crucially needed. Amid several destruction methods, wet air oxidation (WAO) can efficiently treat wastewater containing organic pollutants. It can be used not only for sludge destruction but also for useful by-product production. Volatile fatty acids (VFAs), one of many byproducts, is considered to be an important precursor of biofuel and chemical materials. Its high reaction condition has instituted the study of gravity pressure reactor (GPR) for an economical process of WAO to reduce operation cost. Simulation of subcritical condition was conducted using Aspen Plus with predictive Soave-Redlich-Kwong (PSRK) equation of state. Conjointly, simulation analysis for GPR depth, oxidizer type, sludge flow rate and oxidizer injection position was carried out. At GPR depth of 1000m and flow rate of 2 ton/h, the conversion and yield of VFAs were 92.02% and 0.17g/g, respectively

  19. Formation of hydrophobic coating on glass surface using atmospheric pressure non-thermal plasma in ambient air

    International Nuclear Information System (INIS)

    Fang, Z; Qiu, Y; Kuffel, E

    2004-01-01

    Non-thermal plasmas under atmospheric pressure are of great interest in material surface processing because of their convenience, effectiveness and low cost. In this paper, the treatment of a glass surface for improving hydrophobicity using a non-thermal plasma generated by a dielectric barrier corona discharge (DBCD) with a needle array-to-plane electrode arrangement in atmospheric air is conducted, and the surface properties of the glass before and after the DBCD treatment are studied using contact angle measurement, surface resistance measurement and the wet flashover voltage test. The effects of the plasma dose (the product of average discharge power and treatment time) of DBCD on the surface modification are studied, and the mechanism of interaction between the plasma and glass surface is discussed. It is found that a layer of hydrophobic coating is formed on the glass surface through DBCD treatment, and the improvement of hydrophobicity depends on the plasma dose of the DBCD. It seems that there is an optimum plasma dose for the surface treatment. The test results of thermal ageing and chemical ageing show that the hydrophobic layer has quite stable characteristics

  20. Low Pressure DC Glow Discharge Air Plasma Surface Treatment of Polyethylene (PE) Film for Improvement of Adhesive Properties

    International Nuclear Information System (INIS)

    Pandiyaraj, Krishnasamy Navaneetha; Yoganand, Paramasivam; Selvarajan, Vengatasamy; Deshmukh, Rajendrasing R.; Balasubramanian, Suresh; Maruthamuthu, Sundaram

    2013-01-01

    The present work deals with the change in surface properties of polyethylene (PE) film using DC low pressure glow discharge air plasma and makes it useful for technical applications. The change in hydrophilicity of the modified PE film surface was investigated by measuring contact angle and surface energy as a function of exposure time. Changes in the morphological and chemical composition of PE films were analyzed by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The improvement in adhesion was studied by measuring T-peel and lap-shear strength. The results show that the wettability and surface energy of the PE film has been improved due to the introduction of oxygen-containing polar groups and an increase in surface roughness. The XPS result clearly shows the increase in concentration of oxygen content and the formation of polar groups on the polymer surface. The AFM observation on PE film shows that the roughness of the surface increased due to plasma treatment. The above morphological and chemical changes enhanced the adhesive properties of the PE film surfaces, which was confirmed by T-peel and lap-shear tests.

  1. Analysis on the Spatial Difference of Bacterial Community Structure in Micro-pressure Air-lift Loop Reactor

    Science.gov (United States)

    Wan, L. G.; Lin, Q.; Bian, D. J.; Ren, Q. K.; Xiao, Y. B.; Lu, W. X.

    2018-02-01

    In order to reveal the spatial difference of the bacterial community structure in the Micro-pressure Air-lift Loop Reactor, the activated sludge bacterial at five different representative sites in the reactor were studied by denaturing gradient gel electrophoresis (DGGE). The results of DGGE showed that the difference of environmental conditions (such as substrate concentration, dissolved oxygen and PH, etc.) resulted in different diversity and similarity of microbial flora in different spatial locations. The Shannon-Wiener diversity index of the total bacterial samples from five sludge samples varied from 0.92 to 1.28, the biodiversity index was the smallest at point 5, and the biodiversity index was the highest at point 2. The similarity of the flora between the point 2, 3 and 4 was 80% or more, respectively. The similarity of the flora between the point 5 and the other samples was below 70%, and the similarity of point 2 was only 59.2%. Due to the different contribution of different strains to the removal of pollutants, it can give full play to the synergistic effect of bacterial degradation of pollutants, and further improve the efficiency of sewage treatment.

  2. Design and development of a low cost, high current density power supply for streamer free atmospheric pressure DBD plasma generation in air

    Science.gov (United States)

    Jain, Vishal; Visani, Anand; Srinivasan, R.; Agarwal, Vivek

    2018-03-01

    This paper presents a new power supply architecture for generating a uniform dielectric barrier discharge (DBD) plasma in air medium at atmospheric pressure. It is quite a challenge to generate atmospheric pressure uniform glow discharge plasma, especially in air. This is because air plasma needs very high voltage for initiation of discharge. If the high voltage is used along with high current density, it leads to the formation of streamers, which is undesirable for most applications like textile treatment, etc. Researchers have tried to generate high-density plasma using a RF source, nanosecond pulsed DC source, and medium frequency AC source. However, these solutions suffer from low current discharge and low efficiency due to the addition of an external resistor to control the discharge current. Moreover, they are relatively costly and bulky. This paper presents a new power supply configuration which is very compact and generates high average density (˜0.28 W/cm2) uniform glow DBD plasma in air at atmospheric pressure. The efficiency is also higher as no external resistor is required to control the discharge current. An inherent feature of this topology is that it can drive higher current oscillations (˜50 A peak and 2-3 MHz frequency) into the plasma that damp out due to the plasma dissipation only. A newly proposed model has been used with experimental validation in this paper. Simulations and experimental validation of the proposed topology are included. Also, the application of the generated plasma for polymer film treatment is demonstrated.

  3. Limitations of the effective field approximation for fluid modeling of high frequency discharges in atmospheric pressure air: Application in resonant structures

    Science.gov (United States)

    Kourtzanidis, Konstantinos; Raja, Laxminarayan

    2017-11-01

    We study analytically and demonstrate numerically that the local effective field approximation (LEFA) for plasma fluid modeling of high-frequency (GHz-THz) discharges in atmospheric pressure air is not valid in regions where the time scale for electron energy transfer to heavy particles is less than the time-period of the electromagnetic (EM) wave. Greater than 50% modulation of the electron temperature around its mean value is found for frequencies around and under 10 GHz for atmospheric pressure air discharges. This modulation decreases significantly as the EM wave frequency increases. Fully coupled numerical simulation of a resonant metallic cut-array illuminated by high frequency EM waves demonstrates that the LEFA can lead to significant errors on both temporal and spatial evolution of the plasma, in cases where this modulation is significant. The LEFA for high pressure air discharges is found to be valid when the EM wave frequency is around or higher than 100 GHz. For lower frequencies or when the reduced electric fields are high enough, the Local Energy Approximation should be used for an accurate description of the plasma development. For low gas pressures, the modulation is very low rendering the LEFA valid over a large EM wave frequency range.

  4. Negative pressure of the environmental air in the cleaning area of the materials and sterilization center: a systematic review.

    Science.gov (United States)

    Ciofi-Silva, Caroline Lopes; Hansen, Lisbeth Lima; Almeida, Alda Graciele Claudio Dos Santos; Kawagoe, Julia Yaeko; Padoveze, Maria Clara; Graziano, Kazuko Uchikawa

    2016-09-01

    to analyze the scientific evidence on aerosols generated during cleaning activities of health products in the Central Service Department (CSD) and the impact of the negative pressure of the ambient air in the cleaning area to control the dispersion of aerosols to adjacent areas. for this literature systematic review the following searches were done: search guidelines, manuals or national and international technical standards given by experts; search in the portal and databases PubMed, Scopus, CINAHL and Web of Science; and a manual search of scientific articles. the five technical documents reviewed recommend that the CSD cleaning area should have a negative differential ambient air pressure, but scientific articles on the impact of this intervention were not found. The four articles included talked about aerosols formed after the use of a ultrasonic cleaner (an increased in the contamination especially during use) and pressurized water jet (formation of smaller aerosols 5μm). In a study, the aerosols formed from contaminated the hot tap water with Legionella pneumophila were evaluated. there is evidence of aerosol formation during cleanup activities in CSD. Studies on occupational diseases of respiratory origin of workers who work in CSD should be performed. analisar as evidências científicas sobre aerossóis gerados durante atividades de limpeza dos produtos para saúde no Centro de Material e Esterilização (CME) e o impacto da pressão negativa do ar ambiente na área de limpeza para controle da dispersão de aerossóis para áreas adjacentes. para essa revisão sistemática de literatura foram realizadas: busca de diretrizes, manuais ou normas técnicas nacionais e internacionais indicadas por especialistas; busca no portal e bases de dados PUBMED, SCOPUS, Cinahl e Web of Science; e busca manual de artigos científicos. Os cinco documentos técnicos analisados preconizam que na área de limpeza do CME haja diferencial negativo de pressão do ar ambiente

  5. Air- and N2-Broadening Coefficients and Pressure-Shift Coefficients in the C-12(O2-16) Laser Bands

    Science.gov (United States)

    Devi, V. Malathy; Benner, D. Chris; Smith, Mary Ann H.; Rinsland, Curtis P.

    1998-01-01

    In this paper we report the pressure broadening and the pressure-induced line shift coefficients for 46 individual rovibrational lines in both the (12)C(16)O2, 00(sup 0)1-(10(sup 0)0-02(sup 0)0)I, and 00(sup 0)1-(10(sup 0)0-02(sup 0)0)II, laser bands (laser band I centered at 960.959/cm and laser band II centered at 1063.735/cm) determined from spectra recorded with the McMath-Pierce Fourier transform spectrometer. The results were obtained from analysis of 10 long-path laboratory absorption spectra recorded at room temperature using a multispectrum nonlinear least-squares technique. Pressure effects caused by both air and nitrogen have been investigated. The air-broadening coefficients determined in this study agree well with the values in the 1996 HITRAN database; ratios and standard deviations of the ratios of the present air-broadening measurements to the 1996 HITRAN values for the two laser bands are: 1.005(15) for laser band I and 1.005(14) for laser band II. Broadening by nitrogen is 3 to 4% larger than that of air. The pressure-induced line shift coefficients are found to be transition dependent and different for the P- and R-branch lines with same J" value. No noticeable differences in the shift coefficients caused by air and nitrogen were found. The results obtained are compared with available values previously reported in the literature.

  6. Comparison of the atmospheric- and reduced-pressure HS-SPME strategies for analysis of residual solvents in commercial antibiotics using a steel fiber coated with a multiwalled carbon nanotube/polyaniline nanocomposite.

    Science.gov (United States)

    Ghiasvand, Ali Reza; Nouriasl, Kolsoum; Yazdankhah, Fatemeh

    2018-01-01

    A low-cost, sensitive and reliable reduced-pressure headspace solid-phase microextraction (HS-SPME) setup was developed and evaluated for direct extraction of residual solvents in commercial antibiotics, followed by determination by gas chromatography with flame ionization detection (GC-FID). A stainless steel narrow wire was made porous and adhesive by platinization by a modified electrophoretic deposition method and coated with a polyaniline/multiwalled carbon nanotube nanocomposite. All experimental variables affecting the extraction efficiency were investigated for both atmospheric-pressure and reduced-pressure conditions. Comparison of the optimal experimental conditions and the results demonstrated that the reduced-pressure strategy leads to a remarkable increase in the extraction efficiency and reduction of the extraction time and temperature (10 min, 25 °Ϲ vs 20 min, 40 °Ϲ). Additionally, the reduced-pressure strategy showed better analytical performances compared with those obtained by the conventional HS-SPME-GC-FID method. Limit of detections, linear dynamic ranges, and relative standard deviations of the reduced-pressure HS-SPME procedure for benzene, toluene, ethylbenzene, and xylene (BTEX) in injectable solid drugs were obtained over the ranges of 20-100 pg g -1 , 0.02-40 μg g -1 , and 2.8-10.2%, respectively. The procedure developed was successful for the analysis of BTEX in commercial containers of penicillin, ampicillin, ceftriaxone, and cefazolin. Graphical abstract Schematic representation of the developed RP-HS-SPME setup.

  7. Landfilling of waste incineration residues

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Astrup, Thomas; Cai, Zuansi

    2002-01-01

    Residues from waste incineration are bottom ashes and air-pollution-control (APC) residues including fly ashes. The leaching of heavy metals and salts from the ashes is substantial and a wide spectrum of leaching tests and corresponding criteria have been introduced to regulate the landfilling...

  8. Atmospheric Pressure Indicator.

    Science.gov (United States)

    Salzsieder, John C.

    1995-01-01

    Discusses observable phenomena related to air pressure. Describes a simple, unobtrusive, semiquantitative device to monitor the changes in air pressure that are associated with altitude, using a soft-drink bottle and a balloon. (JRH)

  9. Optimization of Sensing and Feedback Control for Vibration/Flutter of Rotating Disk by PZT Actuators via Air Coupled Pressure

    Directory of Open Access Journals (Sweden)

    Bingfeng Ju

    2011-03-01

    Full Text Available In this paper, a feedback control mechanism and its optimization for rotating disk vibration/flutter via changes of air-coupled pressure generated using piezoelectric patch actuators are studied. A thin disk rotates in an enclosure, which is equipped with a feedback control loop consisting of a micro-sensor, a signal processor, a power amplifier, and several piezoelectric (PZT actuator patches distributed on the cover of the enclosure. The actuator patches are mounted on the inner or the outer surfaces of the enclosure to produce necessary control force required through the airflow around the disk. The control mechanism for rotating disk flutter using enclosure surfaces bonded with sensors and piezoelectric actuators is thoroughly studied through analytical simulations. The sensor output is used to determine the amount of input to the actuator for controlling the response of the disk in a closed loop configuration. The dynamic stability of the disk-enclosure system, together with the feedback control loop, is analyzed as a complex eigenvalue problem, which is solved using Galerkin’s discretization procedure. The results show that the disk flutter can be reduced effectively with proper configurations of the control gain and the phase shift through the actuations of PZT patches. The effectiveness of different feedback control methods in altering system characteristics and system response has been investigated. The control capability, in terms of control gain, phase shift, and especially the physical configuration of actuator patches, are also evaluated by calculating the complex eigenvalues and the maximum displacement produced by the actuators. To achieve a optimal control performance, sizes, positions and shapes of PZT patches used need to be optimized and such optimization has been achieved through numerical simulations.

  10. Effect of dielectric material on bipolar nanosecond pulse diffuse dielectric barrier discharge in air at atmospheric pressure.

    Science.gov (United States)

    Tang, Kai; Wang, Wenchun; Yang, Dezheng; Zhang, Shuai; Yang, Yang; Liu, Zhijie

    2013-08-01

    In this paper, dielectric plates made by ceramic, quartz and polytetrafluoroethylene (PTFE) respectively are employed to generate low gas temperature, diffuse dielectric barrier discharge plasma by using a needle-plate electrode configuration in air at atmospheric pressure. Both discharge images and the optical emission spectra are obtained while ceramic, quartz and PTFE are used as dielectric material. Plasma gas temperature is also calculated by comparing the experimental emission spectra with the best fitted spectra of N2 (C(3)Πu→B(3)Πg 1-3) and N2 (C(3)Πu→B(3)Πg 0-2). The effects of different pulse peak voltages and gas gap distances on the emission intensity of N2 (C(3)Πu→B(3)Πg, 0-0, 337.1 nm) and the plasma area on dielectric surface are investigated while ceramic, quartz and PTFE are used as dielectric material. It is found that the permittivity of dielectric material plays an important role in the discharge homogeneity, plasma gas temperature, emission spectra intensity of the discharge, etc. Dielectric with higher permittivity i.e., ceramic means brighter discharge luminosity and stronger emission spectra intensity of N2 (C(3)Πu→B(3)Πg, 0-0, 337.1 nm) among the three dielectric materials. However, more homogeneous, larger plasma area on dielectric surface and lower plasma gas temperature can be obtained under dielectric with lower permittivity i.e., PTFE. The emission spectra intensity and plasma gas temperature of the discharge while the dielectric plate is made by quartz are smaller than that while ceramic is used as dielectric material and bigger than that when PTFE is used as dielectric material. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Changes in the electro-physical properties of MCT epitaxial films affected by a plasma volume discharge induced by an avalanche beam in atmospheric-pressure air

    Science.gov (United States)

    Grigoryev, D. V.; Voitsekhovskii, A. V.; Lozovoy, K. A.; Tarasenko, V. F.; Shulepov, M. A.

    2015-11-01

    In this paper the influence of the plasma volume discharge of nanosecond duration formed in a non-uniform electric field at atmospheric pressure on samples of epitaxial films HgCdTe (MCT) films are discussed. The experimental data show that the action of pulses of nanosecond volume discharge in air at atmospheric pressure leads to changes in the electrophysical properties of MCT epitaxial films due to formation of a near-surface high- conductivity layer of the n-type conduction. The preliminary results show that it is possible to use such actions in the development of technologies for the controlled change of the properties of MCT.

  12. Comparison of pressurized fluid extraction, Soxhlet extraction and sonication for the determination of polycyclic aromatic hydrocarbons in urban air and diesel exhaust particulate matter.

    Science.gov (United States)

    Rynö, M; Rantanen, L; Papaioannou, E; Konstandopoulos, A G; Koskentalo, T; Savela, K

    2006-04-01

    In order to characterize and compare the chemical composition of diesel particulate matter and ambient air samples collected on filters, different extraction procedures were tested and their extraction efficiencies and recoveries determined. This study is an evaluation of extraction methods using the standard 16 EPA PAHs with HPLC fluorescence analysis. Including LC analysis also GC and MS methods for the determination of PAHs can be used. Soxhlet extraction was compared with ultrasonic agitation and pressurized fluid extraction (PFE) using three solvents to extract PAHs from diesel exhaust and urban air particulates. The selected PAH compounds of soluble organic fractions were analyzed by HPLC with a multiple wavelength shift fluorescence detector. The EPA standard mixture of 16 PAH compounds was used as a standard to identify and quantify diesel exhaust-derived PAHs. The most effective extraction method of those tested was pressurized fluid extraction using dichloromethane as a solvent.

  13. Identifying determinants, pressures and trade-offs of crop residue use in mixed smallholder farms in Sub-Saharan Africa and South Asia

    NARCIS (Netherlands)

    Valbuena Vargas, Diego; Tui, Sabine Homann Kee; Erenstein, Olaf; Teufel, Nils; Duncan, Alan; Abdoulaye, Tahirou; Swain, Braja; Mekonnen, Kindu; Germaine, Ibro; Gérard, Bruno

    2015-01-01

    Crop residues (CR) have become a limited resource in mixed crop-livestock farms. As a result of the increasing demand and low availability of alternative resources, CR became an essential resource for household activities, especially for livestock keeping; a major livelihood element of

  14. Residuation theory

    CERN Document Server

    Blyth, T S; Sneddon, I N; Stark, M

    1972-01-01

    Residuation Theory aims to contribute to literature in the field of ordered algebraic structures, especially on the subject of residual mappings. The book is divided into three chapters. Chapter 1 focuses on ordered sets; directed sets; semilattices; lattices; and complete lattices. Chapter 2 tackles Baer rings; Baer semigroups; Foulis semigroups; residual mappings; the notion of involution; and Boolean algebras. Chapter 3 covers residuated groupoids and semigroups; group homomorphic and isotone homomorphic Boolean images of ordered semigroups; Dubreil-Jacotin and Brouwer semigroups; and loli

  15. In utero exposure to diesel exhaust air pollution promotes adverse intrauterine conditions, resulting in weight gain, altered blood pressure, and increased susceptibility to heart failure in adult mice.

    Directory of Open Access Journals (Sweden)

    Chad S Weldy

    Full Text Available Exposure to fine particulate air pollution (PM₂.₅ is strongly associated with cardiovascular morbidity and mortality. Exposure to PM₂.₅ during pregnancy promotes reduced birthweight, and the associated adverse intrauterine conditions may also promote adult risk of cardiovascular disease. Here, we investigated the potential for in utero exposure to diesel exhaust (DE air pollution, a major source of urban PM₂.₅, to promote adverse intrauterine conditions and influence adult susceptibility to disease. We exposed pregnant female C57Bl/6J mice to DE (≈300 µg/m³ PM₂.₅, 6 hrs/day, 5 days/week from embryonic day (E 0.5 to 17.5. At E17.5 embryos were collected for gravimetric analysis and assessed for evidence of resorption. Placental tissues underwent pathological examination to assess the extent of injury, inflammatory cell infiltration, and oxidative stress. In addition, some dams that were exposed to DE were allowed to give birth to pups and raise offspring in filtered air (FA conditions. At 10-weeks of age, body weight and blood pressure were measured. At 12-weeks of age, cardiac function was assessed by echocardiography. Susceptibility to pressure overload-induced heart failure was then determined after transverse aortic constriction surgery. We found that in utero exposure to DE increases embryo resorption, and promotes placental hemorrhage, focal necrosis, compaction of labyrinth vascular spaces, inflammatory cell infiltration and oxidative stress. In addition, we observed that in utero DE exposure increased body weight, but counterintuitively reduced blood pressure without any changes in baseline cardiac function in adult male mice. Importantly, we observed these mice to have increased susceptibility to pressure-overload induced heart failure, suggesting this in utero exposure to DE 'reprograms' the heart to a heightened susceptibility to failure. These observations provide important data to suggest that developmental

  16. Effect of Initial Moisture Content on the in-Vessel Composting Under Air Pressure of Organic Fraction of MunicipalSolid Waste in Morocco

    Directory of Open Access Journals (Sweden)

    Abdelhadi Makan

    2013-01-01

    Full Text Available This study aimed to evaluate the effect of initial moisture content on the in-vessel composting under air pressure of organic fraction of municipal solid waste in Morocco in terms of internal temperature, produced gases quantity, organic matter conversion rate, and the quality of the final composts.For this purpose, in-vessel bioreactor was designed and used to evaluate both appropriate initial air pressure and appropriate initial moisture content for the composting process. Moreover, 5 experiments were carried out within initial moisture content of 55%, 65%, 70%, 75% and 85%. The initial air pressure and the initial moisture content of the mixture showed a significant effect on the aerobic composting. The experimental results demonstrated that for composting organic waste, relatively high moisture contents are better at achieving higher temperatures and retaining them for longer times.This study suggested that an initial moisture content of around 75%, under 0.6 bar, can be considered as being suitable for efficient composting of organic fraction of municipal solid waste. These last conditions, allowed maximum value of temperature and final composting product with good physicochemical properties as well as higher organic matter degradation and higher gas production. Moreover, final compost obtained showed good maturity levels and can be used for agricultural applications.

  17. Effects of air-abrasion pressure on the resin bond strength to zirconia: a combined cyclic loading and thermocycling aging study

    Directory of Open Access Journals (Sweden)

    Eman Z. Al-Shehri,

    2017-06-01

    Full Text Available Objectives To determine the combined effect of fatigue cyclic loading and thermocycling (CLTC on the shear bond strength (SBS of a resin cement to zirconia surfaces that were previously air-abraded with aluminum oxide (Al2O3 particles at different pressures. Materials and Methods Seventy-two cuboid zirconia specimens were prepared and randomly assigned to 3 groups according to the air-abrasion pressures (1, 2, and 2.8 bar, and each group was further divided into 2 groups depending on aging parameters (n = 12. Panavia F 2.0 was placed on pre-conditioned zirconia surfaces, and SBS testing was performed either after 24 hours or 10,000 fatigue cycles (cyclic loading and 5,000 thermocycles. Non-contact profilometry was used to measure surface roughness. Failure modes were evaluated under optical and scanning electron microscopy. The data were analyzed using 2-way analysis of variance and χ2 tests (α = 0.05. Results The 2.8 bar group showed significantly higher surface roughness compared to the 1 bar group (p < 0.05. The interaction between pressure and time/cycling was not significant on SBS, and pressure did not have a significant effect either. SBS was significantly higher (p = 0.006 for 24 hours storage compared to CLTC. The 2 bar-CLTC group presented significantly higher percentage of pre-test failure during fatigue compared to the other groups. Mixed-failure mode was more frequent than adhesive failure. Conclusions CLTC significantly decreased the SBS values regardless of the air-abrasion pressure used.

  18. Effects of Atmospheric-Pressure N2, He, Air, and O2 Microplasmas on Mung Bean Seed Germination and Seedling Growth

    Science.gov (United States)

    Zhou, Renwu; Zhou, Rusen; Zhang, Xianhui; Zhuang, Jinxing; Yang, Size; Bazaka, Kateryna; (Ken) Ostrikov, Kostya

    2016-09-01

    Atmospheric-pressure N2, He, air, and O2 microplasma arrays have been used to investigate the effects of plasma treatment on seed germination and seedling growth of mung bean in aqueous solution. Seed germination and growth of mung bean were found to strongly depend on the feed gases used to generate plasma and plasma treatment time. Compared to the treatment with atmospheric-pressure O2, N2 and He microplasma arrays, treatment with air microplasma arrays was shown to be more efficient in improving both the seed germination rate and seedling growth, the effect attributed to solution acidification and interactions with plasma-generated reactive oxygen and nitrogen species. Acidic environment caused by air discharge in water may promote leathering of seed chaps, thus enhancing the germination rate of mung bean, and stimulating the growth of hypocotyl and radicle. The interactions between plasma-generated reactive species, such as hydrogen peroxide (H2O2) and nitrogen compounds, and seeds led to a significant acceleration of seed germination and an increase in seedling length of mung bean. Electrolyte leakage rate of mung bean seeds soaked in solution activated using air microplasma was the lowest, while the catalase activity of thus-treated mung bean seeds was the highest compared to other types of microplasma.

  19. Effects of Atmospheric-Pressure N2, He, Air, and O2 Microplasmas on Mung Bean Seed Germination and Seedling Growth.

    Science.gov (United States)

    Zhou, Renwu; Zhou, Rusen; Zhang, Xianhui; Zhuang, Jinxing; Yang, Size; Bazaka, Kateryna; Ken Ostrikov, Kostya

    2016-09-01

    Atmospheric-pressure N2, He, air, and O2 microplasma arrays have been used to investigate the effects of plasma treatment on seed germination and seedling growth of mung bean in aqueous solution. Seed germination and growth of mung bean were found to strongly depend on the feed gases used to generate plasma and plasma treatment time. Compared to the treatment with atmospheric-pressure O2, N2 and He microplasma arrays, treatment with air microplasma arrays was shown to be more efficient in improving both the seed germination rate and seedling growth, the effect attributed to solution acidification and interactions with plasma-generated reactive oxygen and nitrogen species. Acidic environment caused by air discharge in water may promote leathering of seed chaps, thus enhancing the germination rate of mung bean, and stimulating the growth of hypocotyl and radicle. The interactions between plasma-generated reactive species, such as hydrogen peroxide (H2O2) and nitrogen compounds, and seeds led to a significant acceleration of seed germination and an increase in seedling length of mung bean. Electrolyte leakage rate of mung bean seeds soaked in solution activated using air microplasma was the lowest, while the catalase activity of thus-treated mung bean seeds was the highest compared to other types of microplasma.

  20. Air/Liquid-pressure and heartbeat-driven flexible fiber nanogenerators as a micro/nano-power source or diagnostic sensor.

    Science.gov (United States)

    Li, Zetang; Wang, Zhong Lin

    2011-01-04

    We present a new approach for fabricating flexible fiber nanogenerators (FNGs) that can be used for smart shirts, flexible electronics, and medical applications. These FNGs are based on carbon fibers that are covered cylindrically by textured zinc oxide (ZnO) thin films. Once subjected to uni-compression by applying a pressure, the cylindrical ZnO thin film is under a compressive strain, resulting in a macroscopic piezopotential across its inner and exterior surfaces owing to the textured structure of the film, which is the driving force for generating an electric current in the external load. Using such a structure, an output peak voltage of 3.2 V and average current density of 0.15 μA cm(-2) are demonstrated. The FNGs rely on air pressure, so that it can work in a non-contact mode in cases of rotating tires, flowing air/liquid, and even in blood vessels. Pressure-driven FNGs added to a syringe show potential to harvest energy in blood vessels, gas pipes, and oil pipes, as long as there is a fluctuation in pressure (or turbulence). Heart-pulse driven FNGs can serve as ultrasensitive sensors for monitoring the behavior of the human heart, which may possibly be applied to medical diagnostics as sensors and measurement tools.

  1. Experimental and numerical study on laminar burning velocities and flame instabilities of hydrogen-air mixtures at elevated pressures and temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Erjiang; Huang, Zuohua; He, Jiajia; Miao, Haiyan [State Key Laboratory of Multiphase Flow in Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

    2009-10-15

    Experimental and numerical study on hydrogen-air flames at elevated pressures and temperatures was conducted. Meanwhile, the calculation is extended to initial pressure and temperature up to 8.0 MPa and 950 K, respectively. Laminar burning velocities and Markstein lengths were obtained at the elevated pressures and temperatures. Sensitivity analysis and flame structure were also analyzed. The results show good agreement between the computed results and experimental data. The study shows that laminar burning velocities are increased with the increase of initial temperature, and they decrease with the increase of initial pressure. With the increase of initial pressure, advancement of the onset of cellular instability is presented and Markstein length is decreased, indicating an increase of flame instability with the increase of initial pressure. The study shows insensitivity of flame instability to initial temperature. Laminar burning velocity is depended on the competition between the main chain branching reactions and chain termination reaction. The chain branching reactions are the temperature-sensitive reaction, while the termination reaction is the temperature-insensitive reaction. Through the extraction of the overall reaction orders, it is demonstrated that with increasing pressure, the overall reaction orders give a decreasing trend and then increasing trend. This behavior suggests an analogy to three explosion limits of hydrogen/oxygen mixtures. Numerical study also shows that the suppression (or enhancement) of overall chemical reaction with the increase of initial pressure (or temperature) is closely linking to the decrease (or increase) of H, O and OH mole fractions in the flames. Strong correlation is existed between burning velocity and maximum radical concentrations of H and OH radicals in the reaction zone of premixed flames. On the basis of the numerical data, an empirical formula for laminar burning velocity is correlated for the hydrogen-air

  2. Process analysis of pressurized oxy-coal power cycle for carbon capture application integrated with liquid air power generation and binary cycle engines

    International Nuclear Information System (INIS)

    Aneke, Mathew; Wang, Meihong

    2015-01-01

    Highlights: • We model a 573 MW pressurized oxy-coal combustion with supercritical steam cycle. • A 126 MW liquid air power plant was integrated to utilize the nitrogen stream. • We used organic Rankine cycle to recover heat from compressors. • The model was analysed for with and without carbon capture consideration. • Efficiency increase of 12–15% was achieved due to integration and heat recovery. - Abstract: In this paper, the thermodynamic advantage of integrating liquid air power generation (LAPG) process and binary cycle waste heat recovery technology to a standalone pressurized oxy-coal combustion supercritical steam power generation cycle is investigated through modeling and simulation using Aspen Plus® simulation software version 8.4. The study shows that the integration of LAPG process and the use of binary cycle heat engine which convert waste heat from compressor exhaust to electricity, in a standalone pressurized oxy-coal combustion supercritical steam power generation cycle improves the thermodynamic efficiency of the pressurized oxy-coal process. The analysis indicates that such integration can give about 12–15% increase in thermodynamic efficiency when compared with a standalone pressurized oxy-coal process with or without CO 2 capture. It was also found that in a pressurized oxy-coal process, it is better to pump the liquid oxygen from the cryogenic ASU to a very high pressure prior to vapourization in the cryogenic ASU main heat exchanger and subsequently expand the gaseous oxygen to the required combustor pressure than either compressing the atmospheric gaseous oxygen produced from the cryogenic ASU directly to the combustor pressure or pumping the liquid oxygen to the combustor pressure prior to vapourization in the cryogenic ASU main heat exchanger. The power generated from the compressor heat in the flue gas purification, carbon capture and compression unit using binary cycle heat engine was also found to offset about 65% of the

  3. High blood pressure and long-term exposure to indoor noise and air pollution from road traffic.

    Science.gov (United States)

    Foraster, Maria; Künzli, Nino; Aguilera, Inmaculada; Rivera, Marcela; Agis, David; Vila, Joan; Bouso, Laura; Deltell, Alexandre; Marrugat, Jaume; Ramos, Rafel; Sunyer, Jordi; Elosua, Roberto; Basagaña, Xavier

    2014-11-01

    Traffic noise has been associated with prevalence of hypertension, but reports are inconsistent for blood pressure (BP). To ascertain noise effects and to disentangle them from those suspected to be from traffic-related air pollution, it may be essential to estimate people's noise exposure indoors in bedrooms. We analyzed associations between long-term exposure to indoor traffic noise in bedrooms and prevalent hypertension and systolic (SBP) and diastolic (DBP) BP, considering long-term exposure to outdoor nitrogen dioxide (NO2). We evaluated 1,926 cohort participants at baseline (years 2003-2006; Girona, Spain). Outdoor annual average levels of nighttime traffic noise (Lnight) and NO2 were estimated at postal addresses with a detailed traffic noise model and a land-use regression model, respectively. Individual indoor traffic Lnight levels were derived from outdoor Lnight with application of insulations provided by reported noise-reducing factors. We assessed associations for hypertension and BP with multi-exposure logistic and linear regression models, respectively. Median levels were 27.1 dB(A) (indoor Lnight), 56.7 dB(A) (outdoor Lnight), and 26.8 μg/m3 (NO2). Spearman correlations between outdoor and indoor Lnight with NO2 were 0.75 and 0.23, respectively. Indoor Lnight was associated both with hypertension (OR = 1.06; 95% CI: 0.99, 1.13) and SBP (β = 0.72; 95% CI: 0.29, 1.15) per 5 dB(A); and NO2 was associated with hypertension (OR = 1.16; 95% CI: 0.99, 1.36), SBP (β = 1.23; 95% CI: 0.21, 2.25), and DBP (β⊇= 0.56; 95% CI: -0.03, 1.14) per 10 μg/m3. In the outdoor noise model, Lnight was associated only with hypertension and NO2 with BP only. The indoor noise-SBP association was stronger and statistically significant with a threshold at 30 dB(A). Long-term exposure to indoor traffic noise was associated with prevalent hypertension and SBP, independently of NO2. Associations were less consistent for outdoor traffic Lnight and likely affected by

  4. Reviving Abandoned Reservoirs with High-Pressure Air Injection: Application in a Fractured and Karsted Dolomite Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Robert Loucks; Stephen C. Ruppel; Dembla Dhiraj; Julia Gale; Jon Holder; Jeff Kane; Jon Olson; John A. Jackson; Katherine G. Jackson

    2006-09-30

    Despite declining production rates, existing reservoirs in the United States contain vast volumes of remaining oil that is not being effectively recovered. This oil resource constitutes a huge target for the development and application of modern, cost-effective technologies for producing oil. Chief among the barriers to the recovery of this oil are the high costs of designing and implementing conventional advanced recovery technologies in these mature, in many cases pressure-depleted, reservoirs. An additional, increasingly significant barrier is the lack of vital technical expertise necessary for the application of these technologies. This lack of expertise is especially notable among the small operators and independents that operate many of these mature, yet oil-rich, reservoirs. We addressed these barriers to more effective oil recovery by developing, testing, applying, and documenting an innovative technology that can be used by even the smallest operator to significantly increase the flow of oil from mature U.S. reservoirs. The Bureau of Economic Geology and Goldrus Producing Company assembled a multidisciplinary team of geoscientists and engineers to evaluate the applicability of high-pressure air injection (HPAI) in revitalizing a nearly abandoned carbonate reservoir in the Permian Basin of West Texas. The Permian Basin, the largest oil-bearing basin in North America, contains more than 70 billion barrels of remaining oil in place and is an ideal venue to validate this technology. We have demonstrated the potential of HPAI for oil-recovery improvement in preliminary laboratory tests and a reservoir pilot project. To more completely test the technology, this project emphasized detailed characterization of reservoir properties, which were integrated to access the effectiveness and economics of HPAI. The characterization phase of the project utilized geoscientists and petroleum engineers from the Bureau of Economic Geology and the Department of Petroleum

  5. At the Fulcrum of Air Force Identity: Balancing the Internal and External Pressures of Image and Culture

    Science.gov (United States)

    2014-01-01

    one aspect of organizational life; however, it should not take disasters like the Enron collapse, Hurricane Katrina, the Japa- nese surprise attack...Strategy or Our Culture?,” 1145–77. 19. Ehrhard, Air Force Strategy, 48. 20. Ibid., 28. 21. Leslie Wayne, “Is Boeing the Enron of the U.S. Air Force

  6. Evidence for age-dependent air-space enlargement contributing to loss of lung tissue elastic recoil pressure and increased shear modulus in older age.

    Science.gov (United States)

    Subramaniam, K; Kumar, H; Tawhai, M H

    2017-07-01

    As a normal part of mature aging, lung tissue undergoes microstructural changes such as alveolar air-space enlargement and redistribution of collagen and elastin away from the alveolar duct. The older lung also experiences an associated decrease in elastic recoil pressure and an increase in specific tissue elastic moduli, but how this relates mechanistically to microstructural remodeling is not well-understood. In this study, we use a structure-based mechanics analysis to elucidate the contributions of age-related air-space enlargement and redistribution of elastin and collagen to loss of lung elastic recoil pressure and increase in tissue elastic moduli. Our results show that age-related geometric changes can result in reduction of elastic recoil pressure and increase in shear and bulk moduli, which is consistent with published experimental data. All elastic moduli were sensitive to the distribution of stiffness (representing elastic fiber density) in the alveolar wall, with homogenous stiffness near the duct and through the septae resulting in a more compliant tissue. The preferential distribution of elastic proteins around the alveolar duct in the healthy young adult lung therefore provides for a more elastic tissue. NEW & NOTEWORTHY We use a structure-based mechanics analysis to correlate air-space enlargement and redistribution of elastin and collagen to age-related changes in the mechanical behavior of lung parenchyma. Our study highlights that both the cause (redistribution of elastin and collagen) and the structural effect (alveolar air-space enlargement) contribute to decline in lung tissue elastic recoil with age; these results are consistent with published data and provide a new avenue for understanding the mechanics of the older lung. Copyright © 2017 the American Physiological Society.

  7. Estimation of the in-cylinder air/fuel ratio of an internal combustion engine by the use of pressure sensors

    Energy Technology Data Exchange (ETDEWEB)

    Tunestaal, Per

    2000-03-01

    This thesis investigates the use of cylinder pressure measurements for estimation of the in-cylinder air/fuel ratio in a spark ignited internal combustion engine. An estimation model which uses the net heat release profile for estimating the cylinder air/fuel ratio of a spark ignition engine is developed. The net heat release profile is computed from the cylinder pressure trace and quantifies the conversion of chemical energy of the reactants in the charge into thermal energy. The net heat release profile does not take heat- or mass transfer into account. Cycle-averaged air/fuel ratio estimates over a range of engine speeds and loads show an RMS error of 4.1% compared to measurements in the exhaust. A thermochemical model of the combustion process in an internal combustion engine is developed. It uses a simple chemical combustion reaction, polynominal fits of internal energy as function of temperature, and the first law of thermodynamics to derive a relationship between measured cylinder pressure and the progress of the combustion process. Simplifying assumptions are made to arrive at an equation which relates the net heat release to the cylinder pressure. Two methods for estimating the sensor offset of a cylinder pressure transducer are developed. Both methods fit the pressure data during the pre-combustion phase of the compression stroke to a polytropic curve. The first method assumes a known polytropic exponent, and the other estimates the polytropic exponent. The first method results in a linear least-squares problem, and the second method results in a nonlinear least-squares problem. The nonlinear least-squares problem is solved by separating out the nonlinear dependence and solving the single-variable minimization problem. For this, a finite difference Newton method is derived. Using this method, the cost of solving the nonlinear least-squares problem is only slightly higher than solving the linear least-squares problem. Both methods show good statistical

  8. Efficacy and safety of adjunctive modafinil treatment on residual excessive daytime sleepiness among nasal continuous positive airway pressure-treated japanese patients with obstructive sleep apnea syndrome: a double-blind placebo-controlled study.

    Science.gov (United States)

    Inoue, Yuichi; Takasaki, Yuji; Yamashiro, Yoshihiro

    2013-08-15

    This double-blind study evaluated the efficacy and safety of modafinil for treating excessive daytime sleepiness in Japanese patients with obstructive sleep apnea syndrome (OSAS). Patients with residual excessive sleepiness (Epworth Sleepiness Scale [ESS] ≥ 11) on optimal nasal continuous positive airway pressure (nCPAP) therapy (apnea-hypopnea index ≤ 10) were randomized to either 200 mg modafinil (n = 52) or placebo (n = 62) once daily for 4 weeks. Outcomes included baseline-week 4 changes in ESS total score, sleep latency on maintenance of wakefulness test (SL-MWT), nocturnal polysomnography, Pittsburgh Sleep Quality Index (PSQI), and safety. All 114 randomized patients completed the study. Mean change in ESS total score (-6.6 vs -2.4, p modafinil than with placebo. ESS total score decreased from > 11 to modafinil-treated patients and 30.6% of placebo-treated patients (p modafinil and placebo groups, respectively (p = 0.146). Once-daily modafinil was effective and well tolerated for managing residual daytime sleepiness in Japanese OSAS patients with residual excessive daytime sleepiness on optimal nCPAP therapy.

  9. Positive association between short-term ambient air pollution exposure and children blood pressure in China-Result from the Seven Northeast Cities (SNEC) study.

    Science.gov (United States)

    Zeng, Xiao-Wen; Qian, Zhengmin Min; Vaughn, Michael G; Nelson, Erik J; Dharmage, Shyamali C; Bowatte, Gayan; Perret, Jennifer; Chen, Duo-Hong; Ma, Huimin; Lin, Shao; de Foy, Benjamin; Hu, Li-Wen; Yang, Bo-Yi; Xu, Shu-Li; Zhang, Chuan; Tian, Yan-Peng; Nian, Min; Wang, Jia; Xiao, Xiang; Bao, Wen-Wen; Zhang, Ya-Zhi; Dong, Guang-Hui

    2017-05-01

    The impact of ambient air pollution on health causes concerns in China. However, little is known about the association of short-term air pollution exposure with blood pressure (BP) in children. The goal of present study was to assess the association between short-term air pollution and BP in children from a highly polluted area in China. This study enrolled 9354 children in 24 elementary and middle schools (aged 5-17 years) from the Seven Northeast Cities (SNEC) study, respectively, during the period of 2012-2013. Ambient air pollutants, including particulate matter with an aerodynamic diameter of ≤10 μm (PM 10 ), sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ) and ozone (O 3 ) on the days (1-5 days) preceding BP examination were collected from local air monitoring stations. Generalized additive models and two-level regression analyses were used to evaluate the relationship between air pollution and BP after adjusting for other covariates. Results showed that with an interquartile range (IQR) increase in PM 10 (50.0 μg/m 3 ) and O 3 (53.0 μg/m 3 ) level during the 5-day mean exposure, positive associations with elevated BP were observed, with an odds ratio of 2.17 (95% CI, 1.61-2.93) for PM 10 and 2.77 (95% CI, 1.94-3.95) for O 3 . Both systolic BP and diastolic BP levels were positively associated with an IQR increase of four air pollutants at different lag times. Specifically, an IQR increase in the 5-day mean of PM 10 and O 3 was associated with elevation of 2.07 mmHg (95% CI, 1.71-2.44) and 3.29 mmHg (95% CI, 2.86-3.72) in systolic BP, respectively. When stratified by sex, positive relationships were observed for elevated BP with NO 2 exposure only in males. This is the first report on the relationship between ambient short-term air pollution exposure and children BP in China. Findings indicate a need to control air pollutants and protect children from heavy air pollution exposure in China. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Changes in foot pressure elicited by 3D air balance exercise and pelvic stability exercise for functional leg-length discrepancy in adult women.

    Science.gov (United States)

    Lee, Byung-Hoon; Kim, Jeong-Ja; Kim, Chan-Kyu

    2015-03-01

    [Purpose] This study was conducted to examine the effect of pelvic stabilization exercise and 3D equipment exercise on adult women with Functional Leg-Length Discrepancy (FLLD). [Subjects and Methods] Twenty female students in their 20's having FLLD without Structural Leg Length Discrepancy were selected. Exercise was performed for 50 min per session, three times a week, for six weeks. The Pelvic stabilization exercise (PSE) group performed pelvic stabilization exercises for 50 minutes, and the 3D exercise (3DE) group performed 3D Air Balance exercise for 10 minutes after performing the pelvic stabilization exercise program for 40 minutes. [Results] The PSE group showed statistically significant differences in tape measure method (TMM) and maximum pressure between pre-test and post-test, and 3DE showed statistically significant differences in TMM, the difference in maximum pressure, the difference in average pressure, and the difference in support area. At the end of the 6-week intervention, TMM, difference in maximum pressure, difference in average pressure, and difference in support area showed significantly greater reduction in the 3DE group. [Conclusion] The results show that 3D stabilization exercise was more effective at improving the stabilization of the deep muscles surrounding the pelvis and left-right muscular balance. We consider that 3D exercise should be included in exercise programs for improving pelvic cavity and spinal stability in the future.

  11. The high pressure liquid chromatography and its application to the separation of polynuclear aromatic hydrocarbons in atmospheric dust and burning residues

    International Nuclear Information System (INIS)

    Lopez, M.-C.

    1975-09-01

    A new technique of analysis is described: the high speed liquid chromatography or more exactly the high performance liquid chromatography because of the progress achieved on the new packings of the columns. The main types of chromatography, according to the phenomena involved are described: adsorption, partition, ion-exchange and exclusion chromatography. A brief outline is given of the theory for determination of stationary and mobile phases in order to obtain the optimum conditions of separation. Some exemples of possible applications are given, particularly the use of this technique for the separation of polycyclic aromatic hydrocarbons in atmospheric pollution and burning residues [fr

  12. Process combination of thermo pressure hydrolysis and fermentation for innovative processing of residual biogenous mass; Verfahrenskombination aus Thermodruckhydrolyse und Vergaerung zur innovativen Verwertung biogener Restmassen

    Energy Technology Data Exchange (ETDEWEB)

    Prechtl, S.; Merkl, M.; Schieder, D.; Schneider, R.; Bischof, F. [Applikations- und Technikzentrum fuer Energieverfahrens-, Umwelt- und Stroemungstechnik (ATZ-EVUS), Sulzbach-Rosenberg (Germany)

    1999-07-01

    The described processing technique consisting of topped thermal hydrolysis and downstream fermentation is particularly suitable for wet, low-structure organic waste. High turnover rates at short treatment times permit to minimize residues effectively, yield a fair amount of biogas and allow compact design because of low fermenter volumes, which has a positive impact on investment cost. (orig.) [German] Das vorgestellt Verwertungsverfahren bestehend aus vorgeschalteter thermischer Hydrolyse und nachgeschalteter Vergaerung eignet sich besonders fuer nasse, strukturarme organische Abfaelle. Hohe Umsatzraten bei kurzen Behandlungszeiten ermoeglichen eine gute Reststoffminimierung und Biogasausbeute sowie eine kompakte Bauweise durch kleine Fermentervolumina, was sich positiv auf die Investitionskosten auswirkt. (orig.)

  13. Air pressure and other data from fixed platforms as part of the International Decade of Ocean Exploration / Coastal Upwelling Ecosystems Analysis (IDOE/CUEA) from 01 July 1972 to 01 February 1973 (NODC Accession 7400589)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Air pressure and other data were collected from fixed platforms from 01 July 1972 to 01 February 1973. Data were collected by the University of Washington (UW) as...

  14. Air/delta/sea surface temperature, pressure, and other data from MISS GAIL in a world-wide distribution from 21 October 1957 to 18 April 1961 (NODC Accession 0000366)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Air/delta/sea surface temperature, pressure, and other data were collected from the MISS GAIL in a world-wide distribution from October 21, 1957 to April 18, 1961....

  15. STUDI KOMPARATIF EFEK RESIDUAL Bacillus thuringiensis H-14 DAN Bacillus sphaericus H-5a5b TERHADAP LARVA Aedes aegypti PADA BEBERAPA TIPE TEMPAT PENAMPUNG AIR

    Directory of Open Access Journals (Sweden)

    Salamun Salamun

    2012-09-01

    Full Text Available Bacillus thuringiensis H-14 and Bacillus sphaericus H-5a5b are microbial agents showing high potency for vector control. They are highly specific to target insect, and do not produce any adverse environmental impact. Such agents would be very promising agents for vector control, especially vector of dengue haemorrhagic fever in Indonesia.   The present studies aimed at observing the residual effects of B. thuringiensis H-14 (VCRC B17 and B. sphaericus H-5a5b (VCRC B42 on the larvae of Aedes aegypti in some types of water container.   Two steps of the studies were carried out under laboratory conditions. First steps were bioassays to determine of VCRC B17 and VCRC B42 potencies. Second steps were residual effect testings to determine of the residual activities of both VCRC Bl 7 and VCRC B42 in the cemented, clay, and plastic containers.   Bioassays of VCRC B17 and VCRC B42 on Ae. aegypti larvae showed that the Lethal Concentrations 50% were 117.9 ug/l and 790.6 ug/l respectively. Residual effect of VCRC B17 on Ae. aegypti larvae at the concentrations ranging from 1 to 125 mg per litres, in the cemented container was 34 to 91 days, in the clay container was 28 to 49 days, and in the plastic container was 21 to 66 days. Similar studies of VCRC B42 on the same species of mosquito larvae and the same concentration range, the residual effects were 3 to 26 days, 3 to 14 days, and 2 to 16 days respectively in the cemented, clay, and plastic containers.

  16. Residue processing

    Energy Technology Data Exchange (ETDEWEB)

    Gieg, W.; Rank, V.

    1942-10-15

    In the first stage of coal hydrogenation, the liquid phase, light and heavy oils were produced; the latter containing the nonliquefied parts of the coal, the coal ash, and the catalyst substances. It was the problem of residue processing to extract from these so-called let-down oils that which could be used as pasting oils for the coal. The object was to obtain a maximum oil extraction and a complete removal of the solids, because of the latter were returned to the process they would needlessly burden the reaction space. Separation of solids in residue processing could be accomplished by filtration, centrifugation, extraction, distillation, or low-temperature carbonization (L.T.C.). Filtration or centrifugation was most suitable since a maximum oil yield could be expected from it, since only a small portion of the let-down oil contained in the filtration or centrifugation residue had to be thermally treated. The most satisfactory centrifuge at this time was the Laval, which delivered liquid centrifuge residue and centrifuge oil continuously. By comparison, the semi-continuous centrifuges delivered plastic residues which were difficult to handle. Various apparatus such as the spiral screw kiln and the ball kiln were used for low-temperature carbonization of centrifuge residues. Both were based on the idea of carbonization in thin layers. Efforts were also being made to produce electrode carbon and briquette binder as by-products of the liquid coal phase.

  17. Numerical study on pressure drop and heat transfer for designing sodium-to-air heat exchanger tube banks on advanced sodium-cooled fast reactor

    International Nuclear Information System (INIS)

    Kang, Hie-Chan; Eoh, Jae-Hyuk; Cha, Jae-Eun; Kim, Seong-O.

    2013-01-01

    Highlights: ► Numerical simulation for the heat flow characteristic of the sodium-to-air heat exchanger (AHX) and tube banks. ► Parallelogram tube banks showed almost similar thermal and hydraulic characteristics to the rectangular tube banks. ► Pressure drop and heat transfer of the staggered and rectangular tube banks compared with Zhukauskas’ correlation. ► AHX was modeled as porous media and suggested design guide to enhance the performance. - Abstract: A numerical study is performed to investigate the thermal and hydraulic characteristics and build up design model of the AHX (sodium-to-air heat exchanger) unit of a sodium-cooled fast reactor. Helical-coiled tube banks in the AHX are modeled as porous media and simulated heat and momentum transfer by a commercial program. Two-dimensional flow characteristic appears differently at the inlet region of the AHX annulus, and the required length of the inlet region is shorter for an inlet having a 45 degree chamber or a round shape than for one with a perpendicular corner. Pressure drop and heat transfer coefficient for rectangular, parallelogram and staggered tube banks as the main components of the AHX are evaluated and discussed. Pressure drop and heat transfer shows similar trends and underestimated values, respectively, when compared with Zhukauskas empirical correlations. The parallelogram tube bank shows similar results to the rectangular arrangement.

  18. Indoor air pollution and its association with poor lung function, microalbuminuria and variations in blood pressure among kitchen workers in India: a cross-sectional study.

    Science.gov (United States)

    Singh, Amarnath; Kesavachandran, Chandrasekharan Nair; Kamal, Ritul; Bihari, Vipin; Ansari, Afzal; Azeez, Parappurath Abdul; Saxena, Prem Narain; Ks, Anil Kumar; Khan, Altaf Hussain

    2017-04-04

    The present study is an attempt to explore the association between kitchen indoor air pollutants and physiological profiles in kitchen workers with microalbuminuria (MAU) in north India (Lucknow) and south India (Coimbatore). The subjects comprised 145 control subjects, 233 kitchen workers from north India and 186 kitchen workers from south India. Information related to the personal and occupational history and health of the subjects at both locations were collected using a custom-made questionnaire. Worker lung function was measured using a spirometer. Blood pressure was monitored using a sphygmomanometer. Urinary MAU was measured using a urine analyzer. Indoor air monitoring in kitchens for particulate matter (PM), total volatile organic compounds (TVOC), carbon dioxide (CO 2 ) and carbon monoxide (CO) was conducted using indoor air quality monitors. The size and shape of PM in indoor air was assessed using a scanning electron microscope (SEM). Fourier transform infrared (FTIR) spectroscopy was used to detect organic or inorganic compounds in the air samples. Particulate matter concentrations (PM 2.5 and PM 1 ) were significantly higher in both north and south Indian kitchens than in non-kitchen areas. The concentrations of TVOC, CO and CO 2 were higher in the kitchens of north and south India than in the control locations (non-kitchen areas). Coarse, fine and ultrafine particles and several elements were also detected in kitchens in both locations by SEM and elemental analysis. The FTIR spectra of kitchen indoor air at both locations show the presence of organic chemicals. Significant declines in systolic blood pressure and lung function were observed in the kitchen workers with MAU at both locations compared to those of the control subjects. A higher prevalence of obstruction cases with MAU was observed among the workers in the southern region than in the controls (p India have lower lung capacities and a greater risk of obstructive and restrictive

  19. Modeling Residual NAPL in Water-Wet Porous Media

    Directory of Open Access Journals (Sweden)

    R.J. Lenhard

    2002-06-01

    Full Text Available A model is outlined that predicts NAPL which is held in pore wedges and as films or lenses on solid and water surfaces and contributes negligibly to NAPL advection. This is conceptually referred to as residual NAPL. Since residual NAPL is immobile, it remains in the vadose zone after all free NAPL has drained. Residual NAPL is very important because it is a long-term source for groundwater contamination. Recent laboratory experiments have demonstrated that current models for predicting subsurface NAPL behavior are inadequate because they do not correctly predict residual NAPL. The main reason for the failure is a deficiency in the current constitutive theories for multiphase flow that are used in numerical simulators. Multiphase constitutive theory governs the relations among relative permeability, saturation, and pressure for fluid systems (i.e., air, NAPL, water. In this paper, we outline a model describing relations between fluid saturations and pressures that can be combined with existing multiphase constitutive theory to predict residual NAPL. We test the revised constitutive theory by applying it to a scenario involving NAPL imbibition and drainage, as well as water imbibition and drainage. The results suggest that the revised constitutive theory is able to predict the distribution of residual NAPL in the vadose zone as a function of saturation-path history. The revised model describing relations between fluid saturation and pressures will help toward developing or improving numerical multiphase flow simulators.

  20. A study of the air-side heat transfer and pressure drop characteristics of tube-fin 'no-frost' evaporators

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Jader R. Jr.; Melo, Claudio; Hermes, Christian J.L.; Waltrich, Paulo J. [POLO - National Institute of Science and Technology of Refrigeration and Thermophysics, Federal University of Santa Catarina, 88040-900, Florianopolis, SC (Brazil)

    2009-09-15

    A study is presented on the influence of the air flow rate and surface geometry on the thermal-hydraulic performance of commercial tube-fin 'no-frost' evaporators. A specially constructed wind-tunnel calorimeter was used in the experiments from which data on the overall thermal conductance, pressure drop, Colburn j-factor and Darcy friction factor, f, were extracted. Eight different evaporator samples with distinct geometric characteristics, such as number of tube rows, number of fins and fin pitch were tested. Semi-empirical correlations for j and f are proposed in terms of the air-side Reynolds number and the finning factor. A discussion is presented on the performance of the evaporators with respect to specific criteria such as the pumping power as a function of heat transfer capacity and the volume of material in each evaporator. (author)

  1. A comparative pressure analysis of air flow between horizontal and V-Tail of UAV MALE of NACA0012H with speed variation

    OpenAIRE

    Riza Rahmat; Kurniawan Dicky; Wicaksono Arif Budi

    2018-01-01

    NACA0012H is an airfoil type that could be used for Unmanned Aerial Vehicle Medium Altitude Long Endurance. This experiment was used to analyze stress in the surface of Tail of UAV MALE that was caused by air flow. The experiment was conducted using Computational Fluid Dynamics Software. Two designs of tail, horizontal and V-tail, were considered to simulate pressure occurred on the surface of leading edge, chamber and trailing edge. The simulation was developed varying the speed of the UAV M...

  2. Analysis of air-, moisture- and solvent-sensitive chemical compounds by mass spectrometry using an inert atmospheric pressure solids analysis probe.

    Science.gov (United States)

    Mosely, Jackie A; Stokes, Peter; Parker, David; Dyer, Philip W; Messinis, Antonis M

    2018-02-01

    A novel method has been developed that enables chemical compounds to be transferred from an inert atmosphere glove box and into the atmospheric pressure ion source of a mass spectrometer whilst retaining a controlled chemical environment. This innovative method is simple and cheap to implement on some commercially available mass spectrometers. We have termed this approach inert atmospheric pressure solids analysis probe ( iASAP) and demonstrate the benefit of this methodology for two air-/moisture-sensitive chemical compounds whose characterisation by mass spectrometry is now possible and easily achieved. The simplicity of the design means that moving between iASAP and standard ASAP is straightforward and quick, providing a highly flexible platform with rapid sample turnaround.

  3. Boost Pressure Control Strategy to Account for Transient Behavior and Pumping Losses in a Two-Stage Turbocharged Air Path Concept

    Directory of Open Access Journals (Sweden)

    Thivaharan Albin

    2016-07-01

    Full Text Available Increasingly complex air path concepts are investigated to achieve a substantial reduction in fuel consumption while improving the vehicle dynamics. One promising technology is the two-stage turbocharging for gasoline engines, where a high pressure and a low pressure turbocharger are placed in series. For exploiting the high potential, a control concept has to be developed that allows for coordinated management of the two turbocharger stages. In this paper, the control strategy is investigated. Therefore, the effect of the actuated values on transient response and pumping losses is analyzed. Based on these findings, an optimization-based control algorithm is developed that allows taking both requirements into account. The developed new controller allows achieving a fast transient response, while at the same time reducing pumping losses in stationary operation.

  4. Do psychosocial stress and social disadvantage modify the association between air pollution and blood pressure?: the multi-ethnic study of atherosclerosis.

    Science.gov (United States)

    Hicken, Margaret T; Adar, Sara D; Diez Roux, Ana V; O'Neill, Marie S; Magzamen, Sheryl; Auchincloss, Amy H; Kaufman, Joel D

    2013-11-15

    Researchers have theorized that social and psychosocial factors increase vulnerability to the deleterious health effects of environmental hazards. We used baseline examination data (2000-2002) from the Multi-Ethnic Study of Atherosclerosis. Participants were 45-84 years of age and free of clinical cardiovascular disease at enrollment (n = 6814). The modifying role of social and psychosocial factors on the association between exposure to air pollution comprising particulate matter less than 2.5 µm in aerodynamic diameter (PM2.5) and blood pressure measures were examined using linear regression models. There was no evidence of synergistic effects of higher PM2.5 and adverse social/psychosocial factors on blood pressure. In contrast, there was weak evidence of stronger associations of PM2.5 with blood pressure in higher socioeconomic status groups. For example, those in the 10th percentile of the income distribution (i.e., low income) showed no association between PM2.5 and diastolic blood pressure (b = -0.41 mmHg; 95% confidence interval: -1.40, 0.61), whereas those in the 90th percentile of the income distribution (i.e., high income) showed a 1.52-mmHg increase in diastolic blood pressure for each 10-µg/m(3) increase in PM2.5 (95% confidence interval: 0.22, 2.83). Our results are not consistent with the hypothesis that there are stronger associations between PM2.5 exposures and blood pressure in persons of lower socioeconomic status or those with greater psychosocial adversity.

  5. Cost effectiveness of an air-inflated static overlay for pressure ulcer prevention: a randomized, controlled trial.

    Science.gov (United States)

    Vermette, Sophie; Reeves, Isabelle; Lemaire, Jacques

    2012-08-01

     Numerous pressure-relieving surfaces of varying costs are available for the prevention of pressure ulcers. There is insufficient evidence to draw conclusions regarding the efficacy or merits of using more expensive technologies. The purpose of this unblinded, randomized, prospective study was to compare the clinical and the cost effectiveness of an inflated overlay with rented, pressure-relieving surfaces for the prevention of pressure ulcers. Patients in a 257-bed acute care facility were included if they had a Braden score of ≤ 14, had no skin lesion(s), were ≥ 18 years, weighed pressure ulcers and comfort; Fisher's exact and chi- squared tests were used to assess categorical data, and unpaired t-test and Mann-Whitney statistic tests were used to compare continuous variables. Comparative cost of support surface use was determined at the end of the study. In the control group, 50 patients used an MSO and 5 patients used an LALDM; in the experimental group, 55 patients used an ISO. No significant difference in pressure ulcer incidence was found between the control (n = 6) and experimental groups (n = 2) (11% versus 4%, respectively; P = 0.2706), and there was no significant difference in comfort (90% versus 85%; P = 0.7129). However, a significant difference was noted in total cost ($13,606 CAD versus $3,364 CAD, P ≤ 0.001); the ISO was less expensive. The use of an ISO offers a cost-effective option for the prevention of pressure ulcers in a moderate to very high-risk population. .

  6. Compressed air injection technique to standardize block injection pressures : [La technique d'injection d'air comprimé pour normaliser les pressions d'injection d'un blocage nerveux].

    Science.gov (United States)

    Tsui, Ban C H; Li, Lisa X Y; Pillay, Jennifer J

    2006-11-01

    Presently, no standardized technique exists to monitor injection pressures during peripheral nerve blocks. Our objective was to determine if a compressed air injection technique, using an in vitro model based on Boyle's law and typical regional anesthesia equipment, could consistently maintain injection pressures below a 1293 mmHg level associated with clinically significant nerve injury. Injection pressures for 20 and 30 mL syringes with various needle sizes ( 18G, 20G, 21 G, 22G, and 24G) were measured in a closed system. A set volume of air was aspirated into a saline-filled syringe and then compressed and maintained at various percentages while pressure was measured. The needle was inserted into the injection port of a pressure sensor, which had attached extension tubing with an injection plug clamped "off". Using linear regression with all data points, the pressure value and 99% confidence interval (CI) at 50% air compression was estimated. The linearity of Boyle's law was demonstrated with a high correlation, r = 0.99, and a slope of 0.984 (99% CI: 0.967-1.001). The net pressure generated at 50% compression was estimated as 744.8 mmHg, with the 99% CI between 729.6 and 760.0 mmHg. The various syringe/needle combinations had similar results. By creating and maintaining syringe air compression at 50% or less, injection pressures will be substantially below the 1293 mmHg threshold considered to be an associated risk factor for clinically significant nerve injury. This technique may allow simple, real-time and objective monitoring during local anesthetic injections while inherently reducing injection speed. Présentement, aucune technique normalisée ne permet de vérifier les pressions d'injection pendant les blocages nerveux périphériques. Nous voulions vérifier si une technique d'injection d'air comprimé, utilisant un modèle in vitro fondé sur la loi de Boyle et du matériel propre à l'anesthésie régionale, pouvait maintenir avec régularité les

  7. Design of a compressed air modulator to be used in comprehensive multidimensional gas chromatography and its application in the determination of pesticide residues in grapes

    NARCIS (Netherlands)

    Pizzutti, I.R.; Vreuls, J.J.; Kok, A; Roehrs, R.; Martel, S.; Friggi, C.A.; Zanella, R.

    2009-01-01

    In this study, a new modulator that is simple, robust and presents low operation costs, was developed. This modulator uses compressed air to cool two small portions in the first centimeters of the second chromatographic column of a comprehensive multidimensional gas chromatography (GC × GC) system.

  8. Photochemical removal of NO(2) by using 172-nm Xe(2) excimer lamp in N(2) or air at atmospheric pressure.

    Science.gov (United States)

    Tsuji, Masaharu; Kawahara, Masashi; Noda, Kenji; Senda, Makoto; Sako, Hiroshi; Kamo, Naohiro; Kawahara, Takashi; Kamarudin, Khairul Sozana Nor

    2009-03-15

    Photochemical removal of NO(2) in N(2) or air (5-20% O(2)) mixtures was studied by using 172-nm Xe(2) excimer lamps to develop a new simple photochemical aftertreatment technique of NO(2) in air at atmospheric pressure without using any catalysts. When a high power lamp (300 mW/cm(2)) was used, the conversion of NO(2) (200-1000 ppm) to N(2) and O(2) in N(2) was >93% after 1 min irradiation, whereas that to N(2)O(5), HNO(3), N(2), and O(2) in air (10% O(2)) was 100% after 5s irradiation in a batch system. In a flow system, about 92% of NO(2) (200 ppm) in N(2) was converted to N(2) and O(2), whereas NO(2) (200-400 ppm) in air (20% O(2)) could be completely converted to N(2)O(5), HNO(3), N(2), and O(2) at a flow rate of 1l/min. It was found that NO could also be decomposed to N(2) and O(2) under 172-nm irradiation, though the removal rate is slower than that of NO(2) by a factor of 3.8. A simple model analysis assuming a consecutive reaction NO(2)-->NO-->N+O indicated that 86% of NO(2) is decomposed directly into N+O(2) and the rest is dissociated into NO+O under 172-nm irradiation. These results led us to conclude that the present technique is a new promising catalyst-free photochemical aftertreatment method of NO(2) in N(2) and air in a flow system.

  9. Residual risk

    African Journals Online (AJOL)

    ing the residual risk of transmission of HIV by blood transfusion. An epidemiological approach assumed that all HIV infections detected serologically in first-time donors were pre-existing or prevalent infections, and that all infections detected in repeat blood donors were new or incident infections. During 1986 - 1987,0,012%.

  10. Findings of the Maintenance of Wakefulness Test and its relationship with response to modafinil therapy for residual excessive daytime sleepiness in obstructive sleep apnea patients adequately treated with nasal continuous positive airway pressure.

    Science.gov (United States)

    Inoue, Yuichi; Miki, Masuo; Tabata, Toshiyuki

    We aimed to examine the relationship between subjective and objective sleepiness in obstructive sleep apnea syndrome (OSAS) patients with residual sleepiness, and to determine whether baseline objective sleepiness severity predicts the response to modafinil therapy. Data were obtained from a randomized, placebo-controlled modafinil (200 mg/day) study in Japanese OSAS patients with residual sleepiness receiving nasal continuous positive pressure (n-CPAP) treatment. We analyzed 50 participants whose subjective (Epworth Sleepiness Scale [ESS] total score) and objective (Maintenance of Wakefulness Test [MWT] sleep latency) sleepiness were evaluated before and after treatment. Subjects were dichotomized into two subgroups according to the mean baseline MWT sleep latency. ESS total score and MWT sleep latency changes after treatment were compared between the placebo and modafinil groups in both subgroups. The mean baseline ESS total score and MWT sleep latency were 14.1 ± 2.8 and 14.2 ± 4.9 min, respectively; there was no significant correlation between these two variables. Patient characteristics were similar between the two subgroups (MWT sleep latency: modafinil group than in the placebo group (p = 0.005). In the ≥14-min subgroup, changes in these parameters did not differ between the treatment groups. In OSAS patients with residual sleepiness, the objective sleepiness level was not as high as expected, despite increased subjective sleepiness. Improvements in subjective and objective sleepiness seemed difficult to achieve with modafinil treatment among subjects with less objective sleepiness. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Direct detection of benzene, toluene, and ethylbenzene at trace levels in ambient air by atmospheric pressure chemical ionization using a handheld mass spectrometer.

    Science.gov (United States)

    Huang, Guangming; Gao, Liang; Duncan, Jason; Harper, Jason D; Sanders, Nathaniel L; Ouyang, Zheng; Cooks, R Graham

    2010-01-01

    The capabilities of a portable mass spectrometer for real-time monitoring of trace levels of benzene, toluene, and ethylbenzene in air are illustrated. An atmospheric pressure interface was built to implement atmospheric pressure chemical ionization for direct analysis of gas-phase samples on a previously described miniature mass spectrometer (Gao et al. Anal. Chem.2006, 78, 5994-6002). Linear dynamic ranges, limits of detection and other analytical figures of merit were evaluated: for benzene, a limit of detection of 0.2 parts-per-billion was achieved for air samples without any sample preconcentration. The corresponding limits of detection for toluene and ethylbenzene were 0.5 parts-per-billion and 0.7 parts-per-billion, respectively. These detection limits are well below the compounds' permissible exposure levels, even in the presence of added complex mixtures of organics at levels exceeding the parts-per-million level. The linear dynamic ranges of benzene, toluene, and ethylbenzene are limited to approximately two orders of magnitude by saturation of the detection electronics. 2010 American Society for Mass Spectrometry. Published by Elsevier Inc. All rights reserved.

  12. Water absorption lines, 931-961 nm - Selected intensities, N2-collision-broadening coefficients, self-broadening coefficients, and pressure shifts in air

    Science.gov (United States)

    Giver, L. P.; Gentry, B.; Schwemmer, G.; Wilkerson, T. D.

    1982-01-01

    Intensities were measured for 97 lines of H2O vapor between 932 and 961 nm. The lines were selected for their potential usefulness for remote laser measurements of H2O vapor in the earth's atmosphere. The spectra were obtained with several different H2O vapor abundances and N2 broadening gas pressures; the spectral resolution was 0.046/cm FWHM. Measured H2O line intensities range from 7 x 10 to the -25th to 7 x 10 to the -22nd/cm per (molecules/sq cm). H2O self-broadening coefficients were measured for 13 of these strongest lines; the mean value was 0.5/cm per atm. N2-collision-broadening coefficients were measured for 73 lines, and the average was 0.11 cm per atm HWHM. Pressure shifts in air were determined for a sample of six lines between 948 and 950 nm; these lines shift to lower frequency by an amount comparable to 0.1 of the collision-broadened widths measured in air or N2. The measured intensities of many lines of 300-000 band are much larger than expected from prior computations, in some cases by over an order of magnitude. Coriolis interactions with the stronger 201-000 band appear to be the primary cause of the enhancement of these line intensities.

  13. Multi-layer transfer and lamination (MTL) process assisted by a high-pressure air jet for highly efficient solution-processed polymer light emitting diodes.

    Science.gov (United States)

    Hasan, Syed Azkar Ul; Youn, Hongseok

    2017-07-13

    This research reports fabrication of highly efficient polymer light-emitting diodes (PLEDs) by a thermally activated multi-layer transfer and lamination (MTL) process. As the first stage of the fabrication process, multiple layers consisting of a light-emitting polymer, electron transport/electron injection layer and metal cathode were sequentially deposited onto a hydrophobic low-surface energy self-assembled monolayer (SAM)-coated glass substrate. Subsequently, a very rapid delamination of PLEDs multi-layers from the SAM-coated glass was achieved by applying a high-pressure air jet. The custom air jet system ensures the excellent multi-film quality and also prevents the occurrence of common buckling and cracks. In addition, the adhesiveness of polyamide (PA) onto polyethylene terephthalate (PET), which serves as a protective barrier from atmospheric water and oxygen, is thermally activated by heating PA above its glass transition temperature. Finally, once delaminated from the PA/PET, the multi-layer structure (light-emitting polymer/electron transport layer/electron injection layer/metal cathode) was successfully laminated onto the target glass (hole transport layer/transparent anode) with a soft roller under mild pressure for the realization of the PLED device. The maximum brightness of the device fabricated by a thermally activated lamination process was around 13 120 cd m -2 at 8.4 V, whereas the maximum current efficiency and the power efficiency were 5.2 cd A -1 and 4.0 lm W -1 , respectively.

  14. Development of multi-residue method for the determination of pesticides in cereal matrices by isotopic dilution associated to liquid chromatography coupled to tandem mass spectrometry after pressurized liquid extraction

    International Nuclear Information System (INIS)

    El Mrabet, Khadija

    2008-01-01

    Pesticides are nowadays considered as toxic for human health. The maximal residues levels authorized in water and foodstuff are more and more strict. Therefore, selective analytical techniques are necessary for their identification and their quantification. The aim of this thesis was to develop a multi-residue method for the determination of pesticides by isotopic dilution associated to liquid chromatography (LC) coupled with tandem mass spectrometry (MS 2 ) after pressurized liquid extraction. In a first step, an analysis method of phenyl-ureas and triazines in groundwater by isotopic dilution associated to LC/MS 2 after solid phase extraction has been developed. The method has been validated and evaluated by participating to an inter-laboratory study. Concerning cereals, an extraction method of pesticides associated to an analysis by LC/MS 2 has been developed for thirty-eight pesticides representative of twenty-six chemicals families and fourteen labeled compounds in wheat. The analysis has been carried out in reversed phase chromatography. Separation and detection conditions have been optimized. A global analytical protocol consisting of a pressurized liquid extraction step using acetonitrile at 100 deg. C and at 100 bars and followed by purification step of the resulting extract on a polymeric sorbent was developed. The developed method enables to extract thirty-eight pesticides and fourteen labeled compounds from wheat with recovery yield about 85% (RSD =4%, n=3). Moreover, the results show that the application of isotopic dilution can be complex. Although some improvements need to be added regarding experimentation of aged matrices or contaminated samples, the potential of the method has been demonstrated. (author) [fr

  15. Air-pressure, vocal fold vibration and acoustic characteristics of phonation during vocal exercising. - Part 1: Measurement in vivo

    Czech Academy of Sciences Publication Activity Database

    Radolf, Vojtěch; Laukkanen, A. M.; Horáček, Jaromír; Liu, D.

    2014-01-01

    Roč. 21, č. 1 (2014), s. 53-59 ISSN 1802-1484 R&D Projects: GA ČR GPP101/12/P579 Institutional support: RVO:61388998 Keywords : biomechanics of voice * subglottal * oral and transglottal pressure * electroglottography * phonation into tubes Subject RIV: BI - Acoustics

  16. RESIDUAL RISK ASSESSMENT: ETHYLENE OXIDE ...

    Science.gov (United States)

    This document describes the residual risk assessment for the Ethylene Oxide Commercial Sterilization source category. For stationary sources, section 112 (f) of the Clean Air Act requires EPA to assess risks to human health and the environment following implementation of technology-based control standards. If these technology-based control standards do not provide an ample margin of safety, then EPA is required to promulgate addtional standards. This document describes the methodology and results of the residual risk assessment performed for the Ethylene Oxide Commercial Sterilization source category. The results of this analyiss will assist EPA in determining whether a residual risk rule for this source category is appropriate.

  17. Pressure ulcers.

    Science.gov (United States)

    Reddy, Madhuri

    2011-04-28

    Unrelieved pressure or friction of the skin, particularly over bony prominences, can lead to pressure ulcers in up to one third of people in hospitals or community care, and one fifth of nursing home residents. Pressure ulcers are more likely in people with reduced mobility and poor skin condition, such as older people or those with vascular disease. We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of preventive interventions in people at risk of developing pressure ulcers? What are the effects of treatments in people with pressure ulcers? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). We found 64 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. In this systematic review we present information relating to the effectiveness and safety of the following interventions: air-filled vinyl boots, air-fluidised supports, alternating-pressure surfaces (including mattresses), alternative foam mattresses, constant low-pressure supports, debridement, electric profiling beds, electrotherapy, hydrocellular heel supports, low-air-loss beds (including hydrotherapy beds), low-level laser therapy, low-tech constant-low-pressure supports, medical sheepskin overlays, nutritional supplements, orthopaedic wool padding, pressure-relieving overlays on operating tables, pressure-relieving surfaces, repositioning (regular "turning"), seat cushions, standard beds, standard care, standard foam mattresses, standard tables, surgery, therapeutic ultrasound, topical lotions and

  18. At the Fulcrum of Air Force Identity: Balancing the Internal and External Pressures of Image and Culture

    Science.gov (United States)

    2010-06-01

    of organizational dysfunctions. The return to the Organizational Identity Dynamics Model provides a suitable segue to integrate Kevin Corley‘s...of the industry .‖71 As shown in Figure 3, the managerial perspective on identity is essentially a more detailed expression of what Hatch and...most destructive weapon. Nuclear weapons—not an ideological fascination with the Air Corps Tactical School doctrine of long-range industrial bombing

  19. Optimization Parameters of Air-conditioning and Heat Insulation Systems of a Pressurized Cabins of Long-distance Airplanes

    Science.gov (United States)

    Gusev, Sergey A.; Nikolaev, Vladimir N.

    2018-01-01

    The method for determination of an aircraft compartment thermal condition, based on a mathematical model of a compartment thermal condition was developed. Development of solution techniques for solving heat exchange direct and inverse problems and for determining confidence intervals of parametric identification estimations was carried out. The required performance of air-conditioning, ventilation systems and heat insulation depth of crew and passenger cabins were received.

  20. Effects of Atmospheric Pressure Air Plasma Pretreatment on the Seed Germination and Early Growth of Andrographis paniculata

    International Nuclear Information System (INIS)

    Tong Jiayun; He Rui; Zhang Xiaoli; Zhan Ruoting; Chen Weiwen; Yang Size

    2014-01-01

    The objective of this paper is to demonstrate whether air plasma can change the seed germination characteristics, seedling emergence, as well as biochemical reactivity, in Andrographis paniculata (A. paniculata) seedlings by modifying the seed coat and finding a beneficial treatment dose. Eight treatment doses and one control were used to conduct electrical conductivity determination, a germination test, a seedling emergence test and a biochemical assay. The results showed that after being treated with air plasma excited at 5950 V for 10 s, the permeability of the seeds was improved significantly, resulting in the acceleration of seed germination and seedling emergence. In the meantime, the catalase activity and catalase isoenzyme expression were also improved, while the malondialdehyde content in the seedlings was decreased (which means greater counteraction with environmental stress). After being treated with 4250 V for 10 s and 5950 V for 20 s, the seed germination was enhanced, but without an obvious change in seedling emergence. However, after treatment with 3400 V for 20 s and 5100 V for 10 s, the permeability of the seeds was decreased, resulting in a delay in seedling emergence. These results indicate that air plasma can change the physiological and biochemical characteristics of Andrographis paniculata seeds by modifying the seed coat, combined with the effects of the active plasma species, and that different treating doses have different effects

  1. Effects of Atmospheric Pressure Air Plasma Pretreatment on the Seed Germination and Early Growth of Andrographis paniculata

    Science.gov (United States)

    Tong, Jiayun; He, Rui; Zhang, Xiaoli; Zhan, Ruoting; Chen, Weiwen; Yang, Size

    2014-03-01

    The objective of this paper is to demonstrate whether air plasma can change the seed germination characteristics, seedling emergence, as well as biochemical reactivity, in Andrographis paniculata (A. paniculata) seedlings by modifying the seed coat and finding a beneficial treatment dose. Eight treatment doses and one control were used to conduct electrical conductivity determination, a germination test, a seedling emergence test and a biochemical assay. The results showed that after being treated with air plasma excited at 5950 V for 10 s, the permeability of the seeds was improved significantly, resulting in the acceleration of seed germination and seedling emergence. In the meantime, the catalase activity and catalase isoenzyme expression were also improved, while the malondialdehyde content in the seedlings was decreased (which means greater counteraction with environmental stress). After being treated with 4250 V for 10 s and 5950 V for 20 s, the seed germination was enhanced, but without an obvious change in seedling emergence. However, after treatment with 3400 V for 20 s and 5100 V for 10 s, the permeability of the seeds was decreased, resulting in a delay in seedling emergence. These results indicate that air plasma can change the physiological and biochemical characteristics of Andrographis paniculata seeds by modifying the seed coat, combined with the effects of the active plasma species, and that different treating doses have different effects.

  2. Study of air entrainment in high pressure spray: optics diagnostics and application to the Diesel injection; Etude de l'entrainement d'air dans un spray haute pression: diagnostics optiques et application a l'injection diesel

    Energy Technology Data Exchange (ETDEWEB)

    Arbeau, A.

    2004-12-15

    The actual development of the engine must reply to a will of fuel consumption reduction and to norms more and more strict concerning the pollutant emissions. Although the Diesel engines are efficient, the NO{sub x} and particle emissions mainly come from the existence of wealthy fuel zone preventing an optimal combustion. Therefore, the air / fuel mixing preparation, highly controlled by the air entrainment in spray, is essential. In this context, we have developed metrological tools in order to analyse the air entrainment mechanism in a dense spray. The Particle Image Velocimetry (PIV) technique is first applied to a conical spray with an injection pressure less than 100 bars to study the air entrainment in spray. A transfer of the methodologies allows then the characterisation and the understanding of the air entrainment mechanism in high pressure full spray (injection pressure less than 1600 bars) type Diesel one. The influence of injection parameters (injection pressure and back pressure) on the mixing rate is studied. The increase of the injection pressure from 800 to 1600 bars implies an increase of the mixing rate of 60 %. Moreover, the thermodynamic conditions of the ambient air, simulated by the chamber back pressure, widely favours the mixing rate. Actually, this latter increases of 350 % when the chamber back pressure varies from 1 to 7 bars. The experimental results do not follow classical laws of air entrainment in one-phase flow jet with variable density, but are in good agreement with an integral model for air entrainment in an axisymmetric full spray. Finally, the Fluorescence Particle Image Velocimetry (FPIV) is introduced in order to extend the PIV application field in dense two-phase flows. (author)

  3. Effects of sudden air pressure changes on hospital admissions for cardiovascular diseases in Prague, 1994–2009

    Czech Academy of Sciences Publication Activity Database

    Plavcová, Eva; Kyselý, Jan

    2014-01-01

    Roč. 58, č. 6 (2014), s. 1327-1337 ISSN 0020-7128 R&D Projects: GA ČR(CZ) GAP209/11/1985 Institutional support: RVO:68378289 Keywords : weather * pressure change * cardiovascular disease * morbidity * mortality * Central Europe Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 3.246, year: 2014 http://link.springer.com/article/10.1007/s00484-013-0735-y

  4. Residual basins

    International Nuclear Information System (INIS)

    D'Elboux, C.V.; Paiva, I.B.

    1980-01-01

    Exploration for uranium carried out over a major portion of the Rio Grande do Sul Shield has revealed a number of small residual basins developed along glacially eroded channels of pre-Permian age. Mineralization of uranium occurs in two distinct sedimentary units. The lower unit consists of rhythmites overlain by a sequence of black shales, siltstones and coal seams, while the upper one is dominated by sandstones of probable fluvial origin. (Author) [pt

  5. Measuring combined exposure to environmental pressures in urban areas: an air quality and noise pollution assessment approach.

    Science.gov (United States)

    Vlachokostas, Ch; Achillas, Ch; Michailidou, A V; Moussiopoulos, Nu

    2012-02-01

    This study presents a methodological scheme developed to provide a combined air and noise pollution exposure assessment based on measurements from personal portable monitors. Provided that air and noise pollution are considered in a co-exposure approach, they represent a significant environmental hazard to public health. The methodology is demonstrated for the city of Thessaloniki, Greece. The results of an extensive field campaign are presented and the variations in personal exposure between modes of transport, routes, streets and transport microenvironments are evaluated. Air pollution and noise measurements were performed simultaneously along several commuting routes, during the morning and evening rush hours. Combined exposure to environmental pollutants is highlighted based on the Combined Exposure Factor (CEF) and Combined Dose and Exposure Factor (CDEF). The CDEF takes into account the potential relative uptake of each pollutant by considering the physical activities of each citizen. Rather than viewing environmental pollutants separately for planning and environmental sustainability considerations, the possibility of an easy-to-comprehend co-exposure approach based on these two indices is demonstrated. Furthermore, they provide for the first time a combined exposure assessment to these environmental pollutants for Thessaloniki and in this sense they could be of importance for local public authorities and decision makers. A considerable environmental burden for the citizens of Thessaloniki, especially for VOCs and noise pollution levels is observed. The material herein points out the importance of measuring public health stressors and the necessity of considering urban environmental pollution in a holistic way. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Space and time analysis of the nanosecond scale discharges in atmospheric pressure air: I. Gas temperature and vibrational distribution function of N2 and O2

    International Nuclear Information System (INIS)

    Lo, A; Cessou, A; Boubert, P; Vervisch, P

    2014-01-01

    Reliable experimental data on nanosecond discharge plasmas in air become more and more crucial considering their interest in a wide field of applications. However, the investigations on such nonequilibrium plasmas are made difficult by the spatial non-homogeneities, in particular under atmospheric pressure, the wide range of time scales, and the complexity of multi-physics processes involved therein. In this study, we report spatiotemporal experimental analysis on the gas temperature and the vibrational excitation of N 2 and O 2 in their ground electronic state during the post-discharge of an overvoltage nanosecond-pulsed discharge generated in a pin-to-plane gap of air at atmospheric pressure. The gas temperature during the pulsed discharge is measured by optical emission spectroscopy related to the rotational bands of the 0–0 vibrational transition N 2 (C  3  Π u , v = 0) → N 2 (B 3  Π g , v = 0) of nitrogen. The results show a rapid gas heating up to 700 K in tens of nanoseconds after the current rise. This fast gas heating leads to a high gas temperature up to 1000 K measured at 150 ns in the first stages of the post-discharge using spontaneous Raman scattering (SRS). The spatiotemporal measurements of the gas temperature and the vibrational distribution function of N 2 and O 2 , also obtained by SRS, over the post-discharge show the spatial expansion of the high vibrational excitation of N 2 , and the gas heating during the post-discharge. The present measurements, focused on thermal and energetic aspect of the discharge, provide a base for spatiotemporal analysis of gas number densities of N 2 , O 2 and O atoms and hydrodynamic effects achieved during the post-discharge in part II of this investigation. All these results provide space and time database for the validation of plasma chemical models for nanosecond-pulsed discharges at atmospheric pressure air. (paper)

  7. Effect of substrate roughness and working pressure on photocatalyst of N-doped TiO{sub x} films prepared by reactive sputtering with air

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seon-Hong, E-mail: pookter@naver.com [Corporate R and D Center, Samsung SDI Co. Ltd., Yongin 446-577, Gyunggido (Korea, Republic of); Yamasue, Eiji; Okumura, Hideyuki; Ishihara, Keiichi N. [Graduate School of Energy Science, Kyoto University, Yoshida Honmachi, Sakyo, Kyoto 606-8501 (Japan)

    2015-01-01

    Highlights: • Effect of substrate roughness and working pressure on the physical properties and the photocatalytic properties of the N-doped TiO{sub x} films are investigated. • Surface roughness of glass substrate has little influence on the film properties, but significant influence on the photocatalytic ability. • Working pressure has little influence on the produced phases and the atomic bonding configurations, but significant influence on the atomic concentration of the N-doped TiO{sub x} film. • High photocatalysis of N-doped TiO{sub x} film requires the permissible range of the N doping concentration which shows the interstitial complex N doping states in TiO{sub 2}. - Abstract: N-doped TiO{sub x} films on the glass substrate were prepared by radio-frequency (RF) magnetron reactive sputtering of Ti target in a mixed gas of argon and dry air. The effect of substrate roughness and working pressure on the physical properties and the photocatalytic properties of the N-doped TiO{sub x} films was investigated. The surface roughness of glass substrate has little influence on the film properties such as produced phases, lattice parameters, introduced nitrogen contents, and atomic bonding configurations, but significant influence on the surface roughness of film resulting in the variation of the photocatalytic ability. The working pressure has little influence on the produced phases and the atomic bonding configurations, but significant influence on the atomic concentration of the N-doped TiO{sub x} film, resulting in the large variation of optical, structural, and photocatalytic properties. It is suggested that the high photocatalysis of N-doped TiO{sub x} film requires a certain range of the N doping concentration which shows the interstitial complex N doping states in TiO{sub 2}.

  8. Pressure drop and heat transfer of a mercury single-phase flow and an air-mercury two-phase flow in a helical tube under a strong magnetic field

    International Nuclear Information System (INIS)

    Takahashi, Minoru; Momozaki, Yoichi

    2000-01-01

    For the reduction of a large magneto-hydrodynamic (MHD) pressure drop of a liquid metal single-phase flow, a liquid metal two-phase flow cooling system has been proposed. As a fundamental study, MHD pressure drops and heat transfer characteristics of a mercury single-phase flow and an air-mercury two-phase flow were experimentally investigated. A strong transverse magnetic field relevant to the fusion reactor conditions was applied to the mercury single-phase flow and the air-mercury two-phase flow in a helically coiled tube that was inserted in the vertical bore of a solenoidal superconducting magnet. It was found that MHD pressure drops of a mercury single-phase flow in the helically coiled tube were nearly equal to those in a straight tube. The Nusselt number at an outside wall was higher than that at an inside wall both in the mercury single-phase flow in the absence and presence of a magnetic field. The Nusselt number of the mercury single-phase flow decreased, increased and again decreased with an increase in the magnetic flux density. MHD pressure drops did not decrease appreciably by injecting air into a mercury flow and changing the mercury flow into the air-mercury two-phase flow. Remarkable heat transfer enhancement did not appear by the air injection. The injection of air into the mercury flow enhanced heat transfer in the ranges of high mercury flow rate and low magnetic flux density, possibly due to the agitation effect of air bubbles. The air injection deteriorated heat transfer in the range of low mercury flow rates possibly because of the occupation of air near heating wall

  9. Air ejector augmented compressed air energy storage system

    Science.gov (United States)

    Ahrens, F.W.; Kartsounes, G.T.

    Energy is stored in slack demand periods by charging a plurality of underground reservoirs with air to the same peak storage pressure, during peak demand periods throttling the air from one storage reservoir into a gas turbine system at a constant inlet pressure until the air presure in the reservoir falls to said constant inlet pressure, thereupon permitting air in a second reservoir to flow into said gas turbine system while drawing air from the first reservoir through a variable geometry air ejector and adjusting said variable geometry air ejector, said air flow being essentially at the constant inlet pressure of the gas turbine system.

  10. On-line solid phase extraction-liquid chromatography-tandem mass spectrometry for insect repellent residue analysis in surface waters using atmospheric pressure photoionization.

    Science.gov (United States)

    Molins-Delgado, Daniel; García-Sillero, Daniel; Díaz-Cruz, M Silvia; Barceló, Damià

    2018-04-06

    Insect repellents (IRs) are a group of organic chemicals whose function is to prevent the ability of insects of landing in a surface. These compounds have been found in the environment and may pose a risk to non-target organisms. In this study, an on-line solid phase extraction - high performance liquid chromatography-tandem mass spectrometry multiresidue method was developed using an atmospheric photoionization source (SPE-HPLC-(APPI)-MS/MS). The use of the APPI as an alternative ionization technique to electrospray (ESI) and atmospheric pressure chemical ionization (APCI) allowed expanding the range of analytical techniques suitable for the analysis of IRs, so far relied in gas chromatography. High sensitivity and precision was reached with method limits of quantification between 0.2 and 4.6 ng l -1 and interday and intraday precision equal or below 15%. The validated method was applied to the study of surface water samples from three European river basins with different flow regime (Adige River in Italy, Sava River in the Balkans, and Evrotas River in Greece). The results showed that two IRs (DEET and Bayrepel) were ubiquitous in the Sava and Evrotas basins, reaching concentrations as high as 105 μg l -1 of Bayrepel in the Sava River, and 5 μg l -1 of DEET in the Evrotas River. Densely populated areas and effluent waste waters are pointed out as the responsible for this pollution. In the alpine river Adige, only three samples showed low levels of IRs (6.01-37.8 ng l -1 ). The concentrations measured were used to perform an environmental risk assessment based on the hazard quotients (HQs) estimation approach by using the chronic and acute eco-toxicity data available. The results revealed that despite the high frequency and eventually high concentrations of these IRs determined in the three basins, only few sites were at risk, with 1 < HQs < 3.3. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

  11. Probe measurements of electron energy spectrum and plasma-wall interaction in Helium/air micro-plasma at atmospheric pressure

    Science.gov (United States)

    Adams, S. F.; Demidov, V. I.; Hensley, A. L.; Koepke, M. E.; Kurlyandskaya, I. P.; Miles, J. A.; Tolson, B. A.

    2018-02-01

    It is experimentally demonstrated that a wall probe may be a useful instrument for measurement of electron energy spectrum (EES) and the plasma-boundary interaction in a micro-plasma with a nonlocal electron distribution function at atmospheric pressure. The measurements of the EES have been conducted in the plasma of several micro-hollow cathode discharges of differing sizes. The discharges with a flow of Helium gas were exposed to air. Typical results of measurements demonstrate signature of energetic electrons arising due to plasma-chemical reactions. It is experimentally shown that wall probe potential is associated with energetic electrons rather than the ambient electron kinetic energy. The devices may be applicable for developing analytical sensors for extreme environments, including high radiation and high temperatures.

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

    Science.gov (United States)

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

    2017-02-01

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

  13. Smooth- and enhanced-tube heat transfer and pressure drop : Part I. Effect of Prandtl number with air, water, and glycol/water mixtures.

    Energy Technology Data Exchange (ETDEWEB)

    Obot, N. T.; Das, L.; Rabas, T. J.

    2000-11-14

    An extensive experimental investigation was carried out to determine the pressure drop and heat transfer characteristics in laminar, transitional, and turbulent flow through one smooth tube and twenty-three enhanced tubes. The working fluids for the experiments were air, water, ethylene glycol, and ethylene glycol/water mixtures; Prandtl numbers (Pr) ranged from 0.7 to 125.3. The smooth-tube experiments were carried out with Pr values of 0.7, 6.8, 24.8, 39.1, and 125.3; Pr values of 0.7, 6.8, and 24.8 were tested with enhanced tubes. Reynolds number (Re) range (based on the maximum internal diameter of a tube) was 200 to 55,000, depending on Prandtl number and tube geometry. The results are presented and discussed in this paper.

  14. Turbulent and Stable/Unstable Laminar Burning Velocity Measurements from Outwardly Propagating Spherical Hydrogen-Air Flames at Elevated Pressures

    Science.gov (United States)

    Smallbone, Andrew; Tsuneyoshi, Kousaku; Kitagawa, Toshiaki

    The laminar burning velocity of pre-mixed hydrogen-air mixtures was measured in a fan stirred combustion bomb. Unstretched laminar burning velocities and Markstein lengths were obtained at 0.10MPa for equivalence ratios of 0.4, 0.6, 0.8 and 1.0 using high speed flame imaging. The difficulties which arose whilst obtaining similar measurements at 0.25MPa and 0.50MPa are outlined. The turbulent burning velocity was measured at equivalence ratios of 0.4 and 0.8 from explosions carried out at 0.10MPa with turbulence intensities of 0.8 and 1.6m/s. Higher turbulent burning velocity ratios were observed for mixtures which yielded lower Markstein lengths in the laminar combustion experiments.

  15. Associations between Long-Term Air Pollutant Exposures and Blood Pressure in Elderly Residents of Taipei City: A Cross-Sectional Study.

    Science.gov (United States)

    Chen, Szu-Ying; Wu, Chang-Fu; Lee, Jui-Huan; Hoffmann, Barbara; Peters, Annette; Brunekreef, Bert; Chu, Da-Chen; Chan, Chang-Chuan

    2015-08-01

    Limited information is available regarding long-term effects of air pollution on blood pressure (BP) and hypertension. We studied whether 1-year exposures to particulate matter (PM) and nitrogen oxides (NOx) were correlated with BP and hypertension in the elderly. We analyzed cross-sectional data from 27,752 Taipei City residents > 65 years of age who participated in a health examination program in 2009. Land-use regression models were used to estimate participants' 1-year exposures to particulate matter with aerodynamic diameter ≤ 10 μm (PM10), coarse particles (PM2.5-10), fine particles (≤ 2.5 μm; PM2.5), PM2.5 absorbance, NOx, and nitrogen dioxide (NO2). Generalized linear regressions and logistic regressions were used to examine the association between air pollution and BP and hypertension, respectively. Diastolic BP was associated with 1-year exposures to air pollution, with estimates of 0.73 [95% confidence interval (CI): 0.44, 1.03], 0.46 (95% CI: 0.30, 0.63), 0.62 (95% CI: 0.24, 0.99), 0.34 (95% CI: 0.19, 0.50), and 0.65 (95% CI: 0.44, 0.85) mmHg for PM10 (10 μg/m3), PM2.5-10 (5 μg/m3), PM2.5 absorbance (10-5/m), NOx (20 μg/m3), and NO2 (10 μg/m3), respectively. PM2.5 was not associated with diastolic BP, and none of the air pollutants was associated with systolic BP. Associations of diastolic BP with PM10 and PM2.5 absorbance were stronger among participants with hypertension, diabetes, or a body mass index ≥ 25 kg/m2 than among participants without these conditions. One-year air pollution exposures were not associated with hypertension. One-year exposures to PM10, PM2.5-10, PM2.5 absorbance, and NOx were associated with higher diastolic BP in elderly residents of Taipei.

  16. Production of atmospheric pressure diffuse nanosecond pulsed dielectric barrier discharge using the array needles-plate electrode in air

    International Nuclear Information System (INIS)

    Yang Dezheng; Wang Wenchun; Jia Li; Nie Dongxia; Shi Hengchao

    2011-01-01

    In this paper, a bidirectional high pulse voltage with 20 ns rising time is employed to generate an atmospheric pressure diffuse dielectric barrier discharge using the array needles-plate electrode configuration. Both double needle and multiple needle electrode configurations nanosecond pulsed dielectric barrier discharges are investigated. It is found that a diffuse discharge plasma with low gas temperature can be obtained, and the plasma volume increases with the increase of the pulse peak voltage, but remains almost constant with the increase of the pulse repetition rate. In addition to showing the potential application on a topographically nonuniform surface treatment of the discharge, the multiple needle-plate electrode configuration with different needle-plate electrode gaps are also employed to generate diffuse discharge plasma.

  17. Characterizing the effects of elevated temperature on the air void pore structure of advanced gas-cooled reactor pressure vessel concrete using x-ray computed tomography

    Directory of Open Access Journals (Sweden)

    Withers P.J.

    2013-07-01

    Full Text Available X-ray computed tomography (X-ray CT has been applied to nondestructively characterise changes in the microstructure of a concrete used in the pressure vessel structure of Advanced Gas-cooled Reactors (AGR in the UK. Concrete specimens were conditioned at temperatures of 105 °C and 250 °C, to simulate the maximum thermal load expected to occur during a loss of coolant accident (LOCA. Following thermal treatment, these specimens along with an unconditioned control sample were characterised using micro-focus X-ray CT with a spatial resolution of 14.6 microns. The results indicate that the air void pore structure of the specimens experienced significant volume changes as a result of the increasing temperature. The increase in the porous volume was more prevalent at 250 °C. Alterations in air void size distributions were characterized with respect to the unconditioned control specimen. These findings appear to correlate with changes in the uni-axial compressive strength of the conditioned concrete.

  18. Air atmospheric-pressure plasma-jet treatment enhances the attachment of human gingival fibroblasts for early peri-implant soft tissue seals on titanium dental implant abutments.

    Science.gov (United States)

    Lee, Jung-Hwan; Kim, Yong-Hee; Choi, Eun-Ha; Kim, Kwang-Mahn; Kim, Kyoung-Nam

    2015-01-01

    Although dental implants are commonly used for tooth restoration, there is a lack of studies of treatment regimens for preventing extra-oral infection and decreasing osseointegration failures by establishing early peri-implant soft tissue seals on titanium dental implant abutments. In this study, air atmospheric-pressure plasma-jet (AAPPJ) treatment was applied to titanium disks to assay the potential for early peri-implant soft tissue seals on titanium dental implant abutment. After titanium disks were treated with AAPPJ for 10 s at 250, 500, 1000 and 1500 sccm, surface analysis was performed; the control group received air only or no treatment. Human gingival fibroblasts (HGF) were seeded onto the specimens for evaluating cell attachment and proliferation and adherent-cell morphology was visualized via confocal microscopy. In AAPPJ-treated specimens, the water contact angle decreased according to increased flow rate. Oxygen composition increased in XPS, but no topographical changes were detected. The effect of AAPPJ treatment at 1000 sccm was apparent 2 mm from the treated spot, with a 20% increase in early cell attachment and proliferation. Adherent HGF on AAPPJ-treated specimens displayed a stretched phenotype with more vinculin formation than the control group. Within the limitations of this study, the results indicate that AAPPJ treatment may enhance the early attachment and proliferation of HGF for establishing early peri-implant soft tissue seals on titanium dental implant abutments with possible favorable effects of osseointegration of dental implant.

  19. Chaboche-based cyclic material hardening models for 316 SS–316 SS weld under in-air and pressurized water reactor water conditions

    International Nuclear Information System (INIS)

    Mohanty, Subhasish; Soppet, William K.; Majumdar, Saurindranath; Natesan, Krishnamurti

    2016-01-01

    Highlights: • 316 SS–316 SS weld cyclically harden/soften while undergoing fatigue loading. • Cyclic hardening/softening creates cycle dependent stress-strain curves. • This necessitate to estimate the cycle dependence of material properties. • Cyclic evolution of Chaboche parameters are estimated under different conditions. - Abstract: This paper discusses a material hardening models for welds made from 316 stainless steel (SS) to 316 SS. The model parameters were estimated from the strain-versus-stress curves obtained from tensile and fatigue tests conducted under different conditions (air at room temperature, air at 300 °C, and primary loop water conditions for a pressurized water reactor). These data were used to check the fatigue cycle dependency of the material hardening parameters (yield stress, parameters related to Chaboche-based linear and nonlinear kinematic hardening models, etc.). The details of the experimental results, material hardening models, and associated calculated results are published in an Argonne report (ANL/LWRS-15/2). This paper summariz