Science.gov

Sample records for spray experimental device

  1. Experimental study of elementary collection efficiency of aerosols by spray: Design of the experimental device

    SciTech Connect

    Ducret, D.; Vendel, J.; Garrec. S.L.

    1995-02-01

    The safety of a nuclear power plant containment building, in which pressure and temperature could increase because of a overheating reactor accident, can be achieved by spraying water drops. The spray reduces the pressure and the temperature levels by condensation of steam on cold water drops. The more stringent thermodynamic conditions are a pressure of 5.10{sup 5} Pa (due to steam emission) and a temperature of 413 K. Moreover its energy dissipation function, the spray leads to the washout of fission product particles emitted in the reactor building atmosphere. The present study includes a large program devoted to the evaluation of realistic washout rates. The aim of this work is to develop experiments in order to determine the collection efficiency of aerosols by a single drop. To do this, the experimental device has to be designed with fundamental criteria:-Thermodynamic conditions have to be representative of post-accident atmosphere. Thermodynamic equilibrium has to be attained between the water drops and the gaseous phase. Thermophoretic, diffusiophoretic and mechanical effects have to be studied independently. Operating conditions have to be homogenous and constant during each experiment. This paper presents the design of the experimental device. In practice, the consequences on the design of each of the criteria given previously and the necessity of being representative of the real conditions will be described.

  2. Study on collection efficiency of fission products by spray: Experimental device and modelling

    SciTech Connect

    Ducret, D.; Roblot, D.; Vendel, J.; Billarand, Y.

    1997-08-01

    Consequences of an hypothetical overheating reactor accident in nuclear power plants can be limited by spraying cold water drops into containment building. The spray reduces the pressure and the temperature levels by condensation of steam and leads to the washout of fission products (aerosols and gaseous iodine). The present study includes a large program devoted to the evaluation of realistic washout rates. An experimental device (named CARAIDAS) was designed and built in order to determine the collection efficiency of aerosols and iodine absorption by drops with representative conditions of post-accident atmosphere. This experimental device is presented in the paper and more particularly: (1) the experimental enclosure in which representative thermodynamic conditions can be achieved, (2) the monosized drops generator, the drops diameter measurement and the drops collector, (3) the cesium iodide aerosols generator and the aerosols measurements. Modelling of steam condensation on drops aerosols collection and iodine absorption are described. First experimental and code results on drops and aerosols behaviour are compared. 8 refs., 18 figs.

  3. External characteristics of unsteady spray atomization from a nasal spray device.

    PubMed

    Fung, Man Chiu; Inthavong, Kiao; Yang, William; Lappas, Petros; Tu, Jiyuan

    2013-03-01

    The nasal route presents an enormous opportunity to exploit the highly vascularized respiratory airway for systemic drug delivery to provide more rapid onset of therapy and reduced drug degradation compared with conventional oral routes. The dynamics of atomization at low injection pressure is less known as typical spray atomization studies have focused on industrial applications such as fuel injection that are performed at much higher pressure. An experimental test station was designed in house and an alternative method to characterize the external spray is presented. This involved the use of high-speed camera to capture the temporal development of the spray as it is atomized through actuation of the spray device. An image-processing technique based on edge detection was developed to automate processing through the large number of images captured. The results showed that there are three main phases of spray development (prestable, stable, and poststable) that can be correlated by examining the spray width. A comparison with a human nasal cavity is made to put into perspective the dimensions and geometry that the spray atomization produces. This study aimed to extend the current existing set of data to contribute toward a better understanding in nasal spray drug delivery. Copyright © 2013 Wiley Periodicals, Inc.

  4. Thermoelectric Device Fabrication Using Thermal Spray and Laser Micromachining

    NASA Astrophysics Data System (ADS)

    Tewolde, Mahder; Fu, Gaosheng; Hwang, David J.; Zuo, Lei; Sampath, Sanjay; Longtin, Jon P.

    2016-02-01

    Thermoelectric generators (TEGs) are solid-state devices that convert heat directly into electricity. They are used in many engineering applications such as vehicle and industrial waste-heat recovery systems to provide electrical power, improve operating efficiency and reduce costs. State-of-art TEG manufacturing is based on prefabricated materials and a labor-intensive process involving soldering, epoxy bonding, and mechanical clamping for assembly. This reduces their durability and raises costs. Additive manufacturing technologies, such as thermal spray, present opportunities to overcome these challenges. In this work, TEGs have been fabricated for the first time using thermal spray technology and laser micromachining. The TEGs are fabricated directly onto engineering component surfaces. First, current fabrication techniques of TEGs are presented. Next, the steps required to fabricate a thermal spray-based TEG module, including the formation of the metallic interconnect layers and the thermoelectric legs are presented. A technique for bridging the air gap between two adjacent thermoelectric elements for the top layer using a sacrificial filler material is also demonstrated. A flat 50.8 mm × 50.8 mm TEG module is fabricated using this method and its performance is experimentally characterized and found to be in agreement with expected values of open-circuit voltage based on the materials used.

  5. Inert gas spraying device aids in repair of hazardous systems

    NASA Technical Reports Server (NTRS)

    Teleha, S.

    1965-01-01

    Inert gas spraying device aids in safely making mechanical repairs to a cryogenic fluid system without prior emptying of the system. This method can be applied to any natural or bottled gas system and with modifications to gasoline transports.

  6. Effects of nasal drug delivery device and its orientation on sprayed particle deposition in a realistic human nasal cavity.

    PubMed

    Tong, Xuwen; Dong, Jingliang; Shang, Yidan; Inthavong, Kiao; Tu, Jiyuan

    2016-10-01

    In this study, the effects of nasal drug delivery device and the spray nozzle orientation on sprayed droplets deposition in a realistic human nasal cavity were numerically studied. Prior to performing the numerical investigation, an in-house designed automated actuation system representing mean adults actuation force was developed to produce realistic spray plume. Then, the spray plume development was filmed by high speed photography system, and spray characteristics such as spray cone angle, break-up length, and average droplet velocity were obtained through off-line image analysis. Continuing studies utilizing those experimental data as boundary conditions were applied in the following numerical spray simulations using a commercially available nasal spray device, which was inserted into a realistic adult nasal passage with external facial features. Through varying the particle releasing direction, the deposition fractions of selected particle sizes on the main nasal passage for targeted drug delivery were compared. The results demonstrated that the middle spray direction showed superior spray efficiency compared with upper or lower directions, and the 10µm agents were the most suitable particle size as the majority of sprayed agents can be delivered to the targeted area, the main passage. This study elaborates a comprehensive approach to better understand nasal spray mechanism and evaluate its performance for existing nasal delivery practices. Results of this study can assist the pharmaceutical industry to improve the current design of nasal drug delivery device and ultimately benefit more patients through optimized medications delivery. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. EXPERIMENTAL ANIMAL WATERING DEVICE

    DOEpatents

    Finkel, M.P.

    1964-04-01

    A device for watering experimental animals confined in a battery of individual plastic enclosures is described. It consists of a rectangular plastic enclosure having a plurality of fluid-tight compartments, each with a drinking hole near the bottom and a filling hole on the top. The enclosure is immersed in water until filled, its drinking holes sealed with a strip of tape, and it is then placed in the battery. The tape sealing prevents the flow of water from the device, but permits animals to drink by licking the drinking holes. (AEC)

  8. Plasma-sprayed materials for magnetic fusion energy devices

    SciTech Connect

    Smith, M.F.; Croessmann, C.D.; Hosking, F.M.; Watson, R.D.; Koski, J.A.

    1991-01-01

    Plasma spray technology is being evaluated as a means to address important fabrication and maintenance problems associated with plasma-interactive components in magnetic fusion devices (e.g., limiters, divertors, and some first wall surfaces). Low-oxygen vacuum plasma sprayed copper has been tested as a ductile, high thermal conductivity interlayer to limit thermal stress and prevent cracking when brazing pyrolytic graphite (PG) tiles to high-strength metal cooling tubes. A brazed tile/tube assembly with this sprayed interlayer has survived thermal testing up to a surface heat flux of 2.0 kW cm{sup {minus}2} as computed on the basis of the power removed in the sample cooling water. A vacuum-sprayed, tungsten-wire-reinforced, copper composite has also been studied as a means to produce an interlayer with highly anisotropic thermal expansion similar to that of PG. Beryllium and tungsten are the present alternatives to graphite for plasma-facing surfaces. High heat flux testing of plasma-sprayed beryllium samples indicates that adhesion and thermal conductivity must be improved. Plasma-sprayed tungsten has performed well in thermal tests, but other factors may rule out the use of tungsten in near term fusion devices. 6 refs., 6 figs., 1 tab.

  9. 30 CFR 75.1107-7 - Water spray devices; capacity; water supply; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Water spray devices; capacity; water supply; minimum requirements. (a) Where water spray devices are... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Water spray devices; capacity; water supply; minimum requirements. 75.1107-7 Section 75.1107-7 Mineral Resources MINE SAFETY AND HEALTH...

  10. dc-plasma-sprayed electronic-tube device

    DOEpatents

    Meek, T.T.

    1982-01-29

    An electronic tube and associated circuitry which is produced by dc plasma arc spraying techniques is described. The process is carried out in a single step automated process whereby both active and passive devices are produced at very low cost. The circuitry is extremely reliable and is capable of functioning in both high radiation and high temperature environments. The size of the electronic tubes produced are more than an order of magnitude smaller than conventional electronic tubes.

  11. The development of beryllium plasma spray technology for the International Thermonuclear Experimental Reactor (ITER)

    SciTech Connect

    Castro, R.G.; Elliott, K.E.; Hollis, K.J.; Bartlett, A.H.; Watson, R.D.

    1999-02-01

    Over the past five years, four international parties, which include the European Communities, Japan, the Russian Federation and the United States, have been collaborating on the design and development of the International Thermonuclear Experimental Reactor (ITER), the next generation magnetic fusion energy device. During the ITER Engineering Design Activity (EDA), beryllium plasma spray technology was investigated by Los Alamos National Laboratory as a method for fabricating and repairing and the beryllium first wall surface of the ITER tokamak. Significant progress has been made in developing beryllium plasma spraying technology for this application. Information will be presented on the research performed to improve the thermal properties of plasma sprayed beryllium coatings and a method that was developed for cleaning and preparing the surface of beryllium prior to depositing plasma sprayed beryllium coatings. Results of high heat flux testing of the beryllium coatings using electron beam simulated ITER conditions will also be presented.

  12. Inorganic photovoltaic devices fabricated using nanocrystal spray deposition.

    PubMed

    Foos, Edward E; Yoon, Woojun; Lumb, Matthew P; Tischler, Joseph G; Townsend, Troy K

    2013-09-25

    Soluble inorganic nanocrystals offer a potential route to the fabrication of all-inorganic devices using solution deposition techniques. Spray processing offers several advantages over the more common spin- and dip-coating procedures, including reduced material loss during fabrication, higher sample throughput, and deposition over a larger area. The primary difference observed, however, is an overall increase in the film roughness. In an attempt to quantify the impact of this morphology change on the devices, we compare the overall performance of spray-deposited versus spin-coated CdTe-based Schottky junction solar cells and model their dark current-voltage characteristics. Spray deposition of the active layer results in a power conversion efficiency of 2.3 ± 0.3% with a fill factor of 45.7 ± 3.4%, Voc of 0.39 ± 0.06 V, and Jsc of 13.3 ± 3.0 mA/cm(2) under one sun illumination.

  13. Detailed investigation of a vaporising fuel spray. Part 1: Experimental investigation of time averaged spray

    NASA Technical Reports Server (NTRS)

    Yule, A. J.; Seng, C. A.; Boulderstone, R.; Ungut, A.; Felton, P. G.; Chigier, N. A.

    1980-01-01

    A laser tomographic light scattering technique provides rapid and accurate high resolution measurements of droplet sizes, concentrations, and vaporization. Measurements using a computer interfaced thermocouple are presented and it is found that the potential exists for separating gas and liquid temperature measurements and diagnosing local spray density by in situ analysis of the response characteristics of the thermocouple. The thermocouple technique provides a convenient means for measuring mean gas velocity in both hot and cold two phase flows. The experimental spray is axisymmetric and has carefully controlled initial and boundary conditions. The flow is designed to give relatively insignificant transfer of momentum and mass from spray to air flow. The effects of (1) size-dependent droplet dispersion by the turbulence, (2) the initial spatial segregation of droplet sizes during atomization, and (3) the interaction between droplets and coherent large eddies are diagnosed.

  14. Experimental investigation on the characteristics of supersonic fuel spray and configurations of induced shock waves

    PubMed Central

    Wang, Yong; Yu, Yu-song; Li, Guo-xiu; Jia, Tao-ming

    2017-01-01

    The macro characteristics and configurations of induced shock waves of the supersonic sprays are investigated by experimental methods. Visualization study of spray shape is carried out with the high-speed camera. The macro characteristics including spray tip penetration, velocity of spray tip and spray angle are analyzed. The configurations of shock waves are investigated by Schlieren technique. For supersonic sprays, the concept of spray front angle is presented. Effects of Mach number of spray on the spray front angle are investigated. The results show that the shape of spray tip is similar to blunt body when fuel spray is at transonic region. If spray entered the supersonic region, the oblique shock waves are induced instead of normal shock wave. With the velocity of spray increasing, the spray front angle and shock wave angle are increased. The tip region of the supersonic fuel spray is commonly formed a cone. Mean droplet diameter of fuel spray is measured using Malvern’s Spraytec. Then the mean droplet diameter results are compared with three popular empirical models (Hiroyasu’s, Varde’s and Merrigton’s model). It is found that the Merrigton’s model shows a relative good correlation between models and experimental results. Finally, exponent of injection velocity in the Merrigton’s model is fitted with experimental results. PMID:28054555

  15. Experimental investigation on the characteristics of supersonic fuel spray and configurations of induced shock waves

    NASA Astrophysics Data System (ADS)

    Wang, Yong; Yu, Yu-Song; Li, Guo-Xiu; Jia, Tao-Ming

    2017-01-01

    The macro characteristics and configurations of induced shock waves of the supersonic sprays are investigated by experimental methods. Visualization study of spray shape is carried out with the high-speed camera. The macro characteristics including spray tip penetration, velocity of spray tip and spray angle are analyzed. The configurations of shock waves are investigated by Schlieren technique. For supersonic sprays, the concept of spray front angle is presented. Effects of Mach number of spray on the spray front angle are investigated. The results show that the shape of spray tip is similar to blunt body when fuel spray is at transonic region. If spray entered the supersonic region, the oblique shock waves are induced instead of normal shock wave. With the velocity of spray increasing, the spray front angle and shock wave angle are increased. The tip region of the supersonic fuel spray is commonly formed a cone. Mean droplet diameter of fuel spray is measured using Malvern’s Spraytec. Then the mean droplet diameter results are compared with three popular empirical models (Hiroyasu’s, Varde’s and Merrigton’s model). It is found that the Merrigton’s model shows a relative good correlation between models and experimental results. Finally, exponent of injection velocity in the Merrigton’s model is fitted with experimental results.

  16. Spray cooling characteristics of nanofluids for electronic power devices.

    PubMed

    Hsieh, Shou-Shing; Leu, Hsin-Yuan; Liu, Hao-Hsiang

    2015-01-01

    The performance of a single spray for electronic power devices using deionized (DI) water and pure silver (Ag) particles as well as multi-walled carbon nanotube (MCNT) particles, respectively, is studied herein. The tests are performed with a flat horizontal heated surface using a nozzle diameter of 0.5 mm with a definite nozzle-to-target surface distance of 25 mm. The effects of nanoparticle volume fraction and mass flow rate of the liquid on the surface heat flux, including critical heat flux (CHF), are explored. Both steady state and transient data are collected for the two-phase heat transfer coefficient, boiling curve/ cooling history, and the corresponding CHF. The heat transfer removal rate can reach up to 274 W/cm(2) with the corresponding CHF enhancement ratio of 2.4 for the Ag/water nanofluids present at a volume fraction of 0.0075% with a low mass flux of 11.9 × 10(-4) kg/cm(2)s.

  17. Spray cooling characteristics of nanofluids for electronic power devices

    NASA Astrophysics Data System (ADS)

    Hsieh, Shou-Shing; Leu, Hsin-Yuan; Liu, Hao-Hsiang

    2015-03-01

    The performance of a single spray for electronic power devices using deionized (DI) water and pure silver (Ag) particles as well as multi-walled carbon nanotube (MCNT) particles, respectively, is studied herein. The tests are performed with a flat horizontal heated surface using a nozzle diameter of 0.5 mm with a definite nozzle-to-target surface distance of 25 mm. The effects of nanoparticle volume fraction and mass flow rate of the liquid on the surface heat flux, including critical heat flux (CHF), are explored. Both steady state and transient data are collected for the two-phase heat transfer coefficient, boiling curve/ cooling history, and the corresponding CHF. The heat transfer removal rate can reach up to 274 W/cm2 with the corresponding CHF enhancement ratio of 2.4 for the Ag/water nanofluids present at a volume fraction of 0.0075% with a low mass flux of 11.9 × 10-4 kg/cm2s.

  18. Experimental and theoretical study on hollow-cone spray

    NASA Astrophysics Data System (ADS)

    Chang, Keh-Chin; Wang, Muh-Rong; Wu, Wen-Jing; Hong, Chia-Hong

    1993-02-01

    A theoretical and experimental investigation has been conducted to study the two-phase turbulent structure in an isothermal hollow-cone spray. Mean and fluctuating velocity components, drop number density, as well as drop-size distribution were measured with a nonintrusive diagnostic tool, a two-component phase Doppler particle analyzer. Complete initial conditions required for theoretical calculations were also provided with measurements. Theoretical calculations were made with an Eulerian-Lagrangian formulism. Turbulent dispersion effects were numerically simulated using a Monte Carlo method. Turbulence modulation effects were also taken into account in the modeling. The well-defined experimental data were used to assess the accuracy of the resultant Eulerian-Lagrangian model. Comparisons showed that the theoretical predictions, based upon the Eulerian-Lagrangian model, yielded reasonable agreement with the experimental data. The improvements made by inclusion of the selected turbulence modulation model were insignificant in this work.

  19. An experimental investigation of the spray issued from a pMDI using laser diagnostic techniques.

    PubMed

    Dunbar, C A; Watkins, A P; Miller, J F

    1997-01-01

    This research was concerned with the experimental investigation of the spray issued from a pressurised metered-dose inhaler (pMDI) using laser diagnostic techniques and has been motivated by the urgent need to find suitable replacements to the environmentally destructive CFC propellants currently used in the device. The experimental work was conducted using phase-Doppler particle analysis (PDPA), a single particle light scattering technique that provides the simultaneous measurement of drop size, velocity, and concentration, yielding the most detailed temporal and spatial analysis of the pMDI spray to date. Three formulations were studied to compare the performance of an "ozone-friendly" hydrofluoroalkane propellant against that of a traditional CFC propellant mixture and a commercially available CFC formulation containing drug and surfactant. The PDPA analysis was complemented by a visual investigation of the near-orifice flow field using copper laserstrobe microcinematography to obtain information on the primary atomization process of the pMDI. This work was conducted in parallel with the theoretical investigation of the spray issued from a pMDI.

  20. Theoretical and Experimental Particle Velocity in Cold Spray

    NASA Astrophysics Data System (ADS)

    Champagne, Victor K.; Helfritch, Dennis J.; Dinavahi, Surya P. G.; Leyman, Phillip F.

    2011-03-01

    In an effort to corroborate theoretical and experimental techniques used for cold spray particle velocity analysis, two theoretical and one experimental methods were used to analyze the operation of a nozzle accelerating aluminum particles in nitrogen gas. Two-dimensional (2D) axi-symmetric computations of the flow through the nozzle were performed using the Reynolds averaged Navier-Stokes code in a computational fluid dynamics platform. 1D, isentropic, gas-dynamic equations were solved for the same nozzle geometry and initial conditions. Finally, the velocities of particles exiting a nozzle of the same geometry and operated at the same initial conditions were measured by a dual-slit velocimeter. Exit plume particle velocities as determined by the three methods compared reasonably well, and differences could be attributed to frictional and particle distribution effects.

  1. A device for experimental radiosurgery.

    PubMed

    Bova, F; Spiegelmann, R; Friedman, W A

    1991-01-01

    As radiosurgery evolves into a widely available treatment modality for a variety of intracranial lesions, the need for basic research concerning the radiobiology of high-dose single-fraction ionizing radiation becomes crucial. A device especially designed for experimental radiosurgery in the cat is described. It incorporates basic parts of the Kopf stereotactic frame for accurate target positioning. A motorized pendular movement of the machine is used to describe a radiation arc, while the radiation source (either a linear accelerator or a cobalt machine) remains stationary. The pathway of the different radiation arcs is modified by rotation of the animal platform around the machine isocenter. Mechanical accuracy tests have shown a maximal alignment error of 0.15 mm, comparing favorably with that reported for modern clinical radiosurgical systems.

  2. 30 CFR 75.1107-7 - Water spray devices; capacity; water supply; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Water spray devices; capacity; water supply; minimum requirements. 75.1107-7 Section 75.1107-7 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices...

  3. Experimental Study on Electrostatic Hazards in Sprayed Liquid

    NASA Astrophysics Data System (ADS)

    Choi, Kwang Seok; Yamaguma, Mizuki; Ohsawa, Atsushi

    2007-12-01

    In this study, to evaluate ignition hazards in a paint process, electrostatic sparks in the sprayed area and the amount of charge while spraying were observed. With the objective of preventing accidents involving fires and/or explosions, we deal also with the ignitability due to an electrostatic spark of a sprayed liquid relative to the percentage of nitrogen (N2), including compression in an air cylinder. For this study, an air-spray-type handheld gun with a 1-mm-internal-diameter orifice and a supply of air pressure in the range of 0.1 to 1 MPa were used. With regard to the materials, water, including some sodium chloride, was used to investigate the charge amount of the sprayed liquid, and kerosene was selected for ignition tests while spraying. Several electrostatic sparks in the sprayed region were observed while spraying. Some values of the electrostatic charge observed in the course of this study would be unsafe in the painting industry. Thus, if any of the conductive parts of the equipment are not grounded, incendiary electrostatic sparks can result. The ignitability of sprayed liquid was markedly reduced; the percentage of N2 in the air was substituted for pressurized pure air, and its efficiency increased with air pressure.

  4. Fabricating thin-film photovoltaic devices using ultra-sonic spray-coating (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Lidzey, David G.

    2015-10-01

    The scale-up of thin-film electronic devices requires a manufacture tool set that is capable of fabricating thin films at high speed over large areas. One such technique capable of such a task is ultra-sonic spray coating. Here, a target solution is fed onto a vibrating tip that breaks the solution up into very fine droplets, with such droplets being carried to a surface by a gas stream. Such ultra-sonic coating processes are already widely used in Electronics, Medical and Displays industries to create films having excellent smoothness and homogeneity. In this talk, I describe the use of ultra-sonic spray-coating to deposit a range of materials for thin-film optoelectronics. As our spray-coating system operates in air, it was first necessary to explore the relative sensitivity of various conjugated polymer / fullerene blends to an air-based process route. It is found that carbazole based co-polymers are particularly stable, and can be processed in air (by spin-coating) into organic photovoltaic devices (OPV) without any apparent loss in device efficiency. I then show that spray-coating can be used to deposit a range of semiconductor materials into smooth, thin-films, including PEDOT:PSS, MoOx (from a precursor) and a series of polymer:fullerene blends. Using such a technique, we are able to scale up an array of devices having an area of 7 cm2, and using a PBDTTT-EFT:PC70BM blend, obtain OPVs having a power conversion efficiency (PCE) of 8.7%. I then discuss spray-coating as a method to fabricate photovoltaic devices based on CH3NH3PbI(3-x)Clx perovskite films. Here, by optimization of deposition parameters, devices are created having a PCE of 11.1%.

  5. Experimental and numerical analysis of the cooling performance of water spraying systems during a fire.

    PubMed

    Chen, YaoHan; Su, ChungHwei; Tseng, JoMing; Li, WunJie

    2015-01-01

    The water spray systems are effective protection systems in the confined or unconfined spaces to avoid the damage to building structures since the high temperature when fires occur. NFPA 15 and 502 have suggested respectively that the factories or vehicle tunnels install water spray systems to protect the machinery and structures. This study discussed the cooling effect of water spray systems in experimental and numerical analyses. The actual combustion of woods were compared with the numerical simulations. The results showed that although the flame continued, the cooling effects by water spraying process within 120 seconds were obvious. The results also indicated that the simulation results of the fifth version Fire Dynamics Simulator (FDS) overestimated the space temperature before water spraying in the case of the same water spray system.

  6. Experimental and Numerical Analysis of the Cooling Performance of Water Spraying Systems during a Fire

    PubMed Central

    Chen, YaoHan; Su, ChungHwei; Tseng, JoMing; Li, WunJie

    2015-01-01

    The water spray systems are effective protection systems in the confined or unconfined spaces to avoid the damage to building structures since the high temperature when fires occur. NFPA 15 and 502 have suggested respectively that the factories or vehicle tunnels install water spray systems to protect the machinery and structures. This study discussed the cooling effect of water spray systems in experimental and numerical analyses. The actual combustion of woods were compared with the numerical simulations. The results showed that although the flame continued, the cooling effects by water spraying process within 120 seconds were obvious. The results also indicated that the simulation results of the fifth version Fire Dynamics Simulator (FDS) overestimated the space temperature before water spraying in the case of the same water spray system. PMID:25723519

  7. 30 CFR 75.1107-7 - Water spray devices; capacity; water supply; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... toxic compounds. The quantity of liquid chemicals required shall be proportionately less than water as... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Water spray devices; capacity; water supply..., DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES...

  8. 30 CFR 75.1107-7 - Water spray devices; capacity; water supply; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... toxic compounds. The quantity of liquid chemicals required shall be proportionately less than water as... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Water spray devices; capacity; water supply..., DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES...

  9. Friability of spray-applied fireproofing and thermal insulations: laboratory evaluation of prototype test devices

    SciTech Connect

    Rossiter, W.J.; Roberts, W.E.; Mathey, R.G.

    1988-11-01

    This report describes the results of the second phase of a study to develop a field test method for assessing the friability of spray-applied fireproofing and thermal-insulating materials. Phase 2 is the laboratory evaluation of the prototype devices for conducting surface and bulk compression/shear, indentation, abrasion, and impact tests. The results indicated that the surface and bulk compression/shear, indentation, and impact devices provided some measure of discrimination between samples subjectively judged as having high and moderate friability. In contrast, the abrasion device was non-discriminating in that, for all tests, a residue was produced. It was concluded that all devices be included in the field phase of the study using in-place spray-applied fireproofings having different levels of friability.

  10. Simulating washoff of Cu-based fungicide sprays by using a rotating shear device.

    PubMed

    Paradelo, M; Arias-Estévez, M; Nóvoa-Muñoz, Juan Carlos; Pérez-Rodríguez, Paula; Torrado-Agrasar, Ana; López-Periago, J Eugenio

    2008-07-23

    Foliar washoff causes a loss of copper-based pesticides sprayed on crops, leading to an increase in the number of applications and contamination of the soil with Cu. In field studies, the variables that determine the amount of Cu loss are difficult to control. An experimental setup based on a rotating shear device (RSD) was used to estimate the influence of physical factors in the loss of Cu due to washoff of three copper-based fungicides: copper oxychlorhide (CO), Bordeaux mixture (BM), and a mixture of copper oxychlorhide and propylene glycol (CO-PG). Full factorial designs were used to model the loss of Cu from fungicides sprayed on the polypropylene surface of the RSD. Variables in the experiments were rotation speed, wash water volume, and fungicide dose. Good reproducibility was obtained for Cu loss, with a coefficient of variation less than 8%. Mean Cu losses were 27.0, 33.0, and 13.5% of the copper applied in fungicide for the BM, CO, and CO-PG, respectively. Empirical equations were obtained to calculate Cu losses from the rotation speed, wash water volume, and dose, as well as their interactions. CO losses were consistent with a model of particle detachment in which such losses depended on a threshold boundary shear stress required to initiate particle motion. Also, percent CO losses were found to be significantly correlated with the linear momentum at the surface boundary. The momentum values obtained in the RSD tests were similar to those estimated for a rainfall event of 20 mm h(-1) lasting 10 min. The most important mechanism in the loss of CO was the erosion of Cu-bearing particles.

  11. [Experimental evaluation of the spraying disinfection efficiency on dental models].

    PubMed

    Zhang, Yi; Fu, Yuan-fei; Xu, Kan

    2013-08-01

    To evaluate the disinfect effect after spraying a new kind of disinfectant on the dental plaster models. The germ-free plaster samples, which were smeared with bacteria compound including Staphylococcus aureus, Escherichia coli, Saccharomyces albicans, Streptococcus mutans and Actinomyces viscosus were sprayed with disinfectants (CaviCide) and glutaraldehyde individually. In one group(5 minutes later) and another group(15 minutes later), the colonies were counted for statistical analysis after sampling, inoculating, and culturing which were used for evaluation of disinfecting efficiency. ANOVA was performed using SPSS12.0 software package. All sample bacteria were eradicated after spraying disinfectants(CaviCide) within 5 minutes and effective bacteria control was retained after 15 minutes. There was significant difference between the disinfecting efficiency of CaviCide and glutaraldehyde. The effect of disinfection with spraying disinfectants (CaviCide) on dental models is quick and effective.

  12. Friability of spray-applied fireproofing and thermal insulations: field evaluation of prototype test devices

    SciTech Connect

    Rossiter, W.J.; Roberts, W.E.; Mathey, R.G.

    1989-03-01

    The report describes results of the third and final phase of a study conducted for the General Services Administration (GSA) to develop a field-test method to measure the friability of spray-applied fireproofing and thermal-insulation materials. Field tests were conducted on 17 fibrous and 2 cementitious spray-applied materials to assess surface and bulk compression/shear, indentation, abrasion, and impact properties. The tests were performed using prototype devices developed in an earlier phase of the study. As expected, the field specimens displayed varying response to dislodgment or indentation in the tests. The field tests confirmed that the goal of the study had been achieved.

  13. Direct spraying method for fabrication of paper-based microfluidic devices

    NASA Astrophysics Data System (ADS)

    Liu, Ning; Xu, Jing; An, Hong-Jie; Phan, Dinh-Tuan; Hashimoto, Michinao; Siang Lew, Wen

    2017-10-01

    Direct spraying of hydrophobic materials is an affordable, easy-to-use and equipment-free method for fabrication of flexible microsensors, albeit not yet widely adopted. To explore its application potential, in this paper, we propose and demonstrate two novel hybrid methods to fabricate paper-based components. Firstly, through combing direct spraying with Parafilm embedding, a leak-free paper-based sample preconcentrator for fluorescence sensing was fabricated. The leak-free device worked on the principle of ion concentration polarization (ICP) effect, and achieved enhancement of fluorescent tracer by 220 folds on a paper substrate. Secondly, by using the sprayed hydrophobic patterns, paper-based microsized supercapacitors (mSCs) were fabricated. Vacuum filtration was used to deposit multi-wall carbon nanotubes (MWCNT)-dispersed solution on a porous substrate to form electrodes. A volumetric capacitance of 42.5 mF cm‑3 at a current density of 2 mA cm‑3 was obtained on the paper-based mSC. Our demonstrations have shown the versatility of direct spraying for the fabrication of integrative paper-based microfluidic devices.

  14. A theoretical and experimental study of turbulent nonevaporating sprays

    NASA Technical Reports Server (NTRS)

    Solomon, A. S. P.; Shuen, J. S.; Zhang, Q. F.; Faeth, G. M.

    1984-01-01

    Measurements and analysis limited to the dilute portions of turbulent nonevaporating sprays injected into a still air environment were completed. Mean and fluctuating velocities and Reynolds stress were measured in the continuous phase. Liquid phase measurements included liquid mass fluxes, drop sizes and drop size and velocity correlation. Initial conditions needed for model evaluation were measured at a location as close to the injector exit as possible. The test sprays showed significant effects of slip and turbulent dispersion of the discrete phase. The measurements were used to evaluate three typical models of these processes: (1) a locally homogenous flow (LHF) model, where slip between the phases were neglected; (2) a deterministic separated flow (DSF) model, where slip was considered but effects of drop dispersion by turbulence were ignored; and (3) a stochastic separated flow (SSF) model, where effects of interphase slip and turbulent dispersion were considered using random-walk computations for drop motion. The LHF and DSF models did not provide very satisfactory predictions for the present measurements. In contrast, the SSF model performed reasonably well with no modifications in the prescription of eddy properties from its original calibration. Some effects of drops on turbulence properties were observed near the dense regions of the sprays.

  15. Monolithic Microfluidic Mixing-Spraying Devices for Time-Resolved Cryo-Electron Microscopy

    PubMed Central

    Lu, Zonghuan; Shaikh, Tanvir R.; Barnard, David; Meng, Xing; Mohamed, Hisham; Yassin, Aymen; Mannella, Carmen A.; Agrawal, Rajendra K.; Lu, Toh-Ming

    2009-01-01

    The goal of time-resolved cryo-electron microscopy is to determine structural models for transient functional states of large macromolecular complexes such as ribosomes and viruses. The challenge of time-resolved cryo-electron microscopy is to rapidly mix reactants, and then, following a defined time interval, to rapidly deposit them as a thin film and freeze the sample to the vitreous state. Here we describe a methodology in which reaction components are mixed and allowed to react, and are then sprayed onto an EM grid as it is being plunged into cryogen. All steps are accomplished by a monolithic, microfabricated silicon device that incorporates a mixer, reaction channel, and pneumatic sprayer in a single chip. We have found that microdroplets produced by air atomization spread to sufficiently thin films on a millisecond time scale provided that the carbon supporting film is made suitably hydrophilic. The device incorporates two T-mixers flowing into a single channel of four butterfly-shaped mixing elements that ensure effective mixing, followed by a microfluidic reaction channel whose length can be varied to achieve the desired reaction time. The reaction channel is flanked by two ports connected to compressed humidified nitrogen gas (at 50 psi) to generate the spray. The monolithic mixer-sprayer is incorporated into a computer-controlled plunging apparatus. To test the mixing performance and the suitability of the device for preparation of biological macromolecules for cryo-EM, ribosomes and ferritin were mixed in the device and sprayed onto grids. Three-dimensional reconstructions of the ribosomes demonstrated retention of native structure, and 30S and 50S subunits were shown to be capable of reassociation into ribosomes after passage through the device. PMID:19683579

  16. Ultrasonic spray coating polymer and small molecular organic film for organic light-emitting devices

    PubMed Central

    Liu, Shihao; Zhang, Xiang; Zhang, Letian; Xie, Wenfa

    2016-01-01

    Ultrasonic spray coating process (USCP) with high material -utilization, low manufacture costs and compatibility to streamline production has been attractive in researches on photoelectric devices. However, surface tension exists in the solvent is still a huge obstacle to realize smooth organic film for organic light emitting devices (OLEDs) by USCP. Here, high quality polymer anode buffer layer and small molecular emitting layer are successfully realized through USCP by introducing extra-low surface tension diluent and surface tension control method. The introduction of low surface tension methyl alcohol is beneficial to the formation of poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) films and brings obvious phase separation and improved conductivity to PEDOT:PSS film. Besides, a surface tension control method, in which new stable tension equilibrium is built at the border of wetting layer, is proposed to eliminate the effect of surface tension during the solvent evaporation stage of ultrasonic spray coating the film consists of 9,9-Spirobifluoren-2-yl-diphenyl-phosphine oxide doped with 10 wt% tris [2-(p -tolyl) pyridine] iridium (III). A smooth and homogenous small molecular emitting layer without wrinkles is successfully realized. The effectiveness of the ultrasonic spray coating polymer anode buffer layer and small molecular emitting layer are also proved by introducing them in OLEDs. PMID:27874030

  17. Ultrasonic spray coating polymer and small molecular organic film for organic light-emitting devices.

    PubMed

    Liu, Shihao; Zhang, Xiang; Zhang, Letian; Xie, Wenfa

    2016-11-22

    Ultrasonic spray coating process (USCP) with high material -utilization, low manufacture costs and compatibility to streamline production has been attractive in researches on photoelectric devices. However, surface tension exists in the solvent is still a huge obstacle to realize smooth organic film for organic light emitting devices (OLEDs) by USCP. Here, high quality polymer anode buffer layer and small molecular emitting layer are successfully realized through USCP by introducing extra-low surface tension diluent and surface tension control method. The introduction of low surface tension methyl alcohol is beneficial to the formation of poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) films and brings obvious phase separation and improved conductivity to PEDOT:PSS film. Besides, a surface tension control method, in which new stable tension equilibrium is built at the border of wetting layer, is proposed to eliminate the effect of surface tension during the solvent evaporation stage of ultrasonic spray coating the film consists of 9,9-Spirobifluoren-2-yl-diphenyl-phosphine oxide doped with 10 wt% tris [2-(p -tolyl) pyridine] iridium (III). A smooth and homogenous small molecular emitting layer without wrinkles is successfully realized. The effectiveness of the ultrasonic spray coating polymer anode buffer layer and small molecular emitting layer are also proved by introducing them in OLEDs.

  18. Ultrasonic spray coating polymer and small molecular organic film for organic light-emitting devices

    NASA Astrophysics Data System (ADS)

    Liu, Shihao; Zhang, Xiang; Zhang, Letian; Xie, Wenfa

    2016-11-01

    Ultrasonic spray coating process (USCP) with high material -utilization, low manufacture costs and compatibility to streamline production has been attractive in researches on photoelectric devices. However, surface tension exists in the solvent is still a huge obstacle to realize smooth organic film for organic light emitting devices (OLEDs) by USCP. Here, high quality polymer anode buffer layer and small molecular emitting layer are successfully realized through USCP by introducing extra-low surface tension diluent and surface tension control method. The introduction of low surface tension methyl alcohol is beneficial to the formation of poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) films and brings obvious phase separation and improved conductivity to PEDOT:PSS film. Besides, a surface tension control method, in which new stable tension equilibrium is built at the border of wetting layer, is proposed to eliminate the effect of surface tension during the solvent evaporation stage of ultrasonic spray coating the film consists of 9,9-Spirobifluoren-2-yl-diphenyl-phosphine oxide doped with 10 wt% tris [2-(p -tolyl) pyridine] iridium (III). A smooth and homogenous small molecular emitting layer without wrinkles is successfully realized. The effectiveness of the ultrasonic spray coating polymer anode buffer layer and small molecular emitting layer are also proved by introducing them in OLEDs.

  19. Lidocaine gel vs lidocaine spray in reducing pain during insertion of the intrauterine contraceptive device.

    PubMed

    Torky, Haitham; Moussa, Asem; El-Desouky, El-Sayed; Dief, Osama; Ahmed, Ali

    2017-04-01

    The aim of this study was to compare the pain-relieving effect of intracervical lidocaine gel with that of lidocaine spray or no local anaesthesia in decreasing pain during insertion of the intrauterine contraceptive device (IUCD). In a prospective multicentre non-randomised comparative study design, 420 women were divided into three groups of 140 and fitted with the same type of IUCD. Group 1 received cervical lidocaine gel, group 2 received cervical lidocaine spray and group 3 received no topical anaesthesia. A visual analogue scale was used to measure the degree of pain experienced. There were no significant differences between the three groups with regard to baseline characteristics such as age and number of deliveries. Significantly less pain was felt during cervical traction in women using a local anaesthetic. However, there were no significant differences in pain due to IUCD insertion. Application of a local anaesthetic decreased the pain resulting from cervical traction but not that resulting from IUCD insertion.

  20. Laminar counterflow spray diffusion flames: A comparison between experimental results and complex chemistry calculations

    SciTech Connect

    Darabiha, N.; Lacas, F.; Rolon, J.C.; Candel, S. . Lab. EM2C)

    1993-11-01

    Experimental and numerical studies of laminar flames formed by the counterflow of a monodisperse fuel spray with an air stream are reported in this article. In this simple configuration it is possible to analyze the influence of the phase transfer terms on the flame structure. The experimental setup used to produce such laminar spray diffusion flames is first described. A set of experiments are carried with liquid heptane fuel sprays. The flame is characterized with a laser sheet imaging system and with a particle sizing apparatus based on laser light diffraction. Results of a numerical study are then presented. The two phase-reacting flow equations are solved through Newton iterations and adaptive gridding using detailed transport and complex chemistry. An iterative procedure is devised to solve the gas- and liquid-phase balance equations. Comparison between experimental and numerical values of the diameter are found to be in good agreement.

  1. A theoretical and experimental study of turbulent evaporating sprays

    NASA Technical Reports Server (NTRS)

    Solomon, A. S. P.; Shuen, J. S.; Zhang, Q. F.; Faeth, G. M.

    1984-01-01

    Measurements and analysis limited to the dilute portions of turbulent evaporating sprays, injected into a still air environment were completed. Mean and fluctuating velocities and Reynolds stress were measured in the continuous phase. Liquid phase measurements included liquid mass fluxes, drop sizes and drop size and velocity correlation. Initial conditions needed for model evaluation were measured at a location as close to the injector exit as possible. The test sprays showed significant effects of slip and turbulent dispersion of the discrete phase. The measurements were used to evaluate three typical models of these processes: (1) a locally homogeneous flow (LHF) model, where slip between the phases were neglected; (2) a deterministic separated flow (DSF) model, where slip was considered but effects of drop dispersion by turbulence were ignored; and (3) a stochastic separated flow (SSF) model, where effects of interphase slip and turbulent dispersion were considered using random-walk computations for drop motion. For all three models, a k-epsilon model as used to find the properties of the continuous phase. The LHF and DSF models did not provide very satisfactory predictions for the present measurements. In contrast, the SSF model performed reasonably well--with no modifications in the prescription of eddy properties from its original calibration.

  2. Double-blind, placebo-controlled study of azelastine and fluticasone in a single nasal spray delivery device.

    PubMed

    Hampel, Frank C; Ratner, Paul H; Van Bavel, Julius; Amar, N J; Daftary, Pramila; Wheeler, William; Sacks, Harry

    2010-08-01

    A proof-of-concept study suggested that combination therapy with commercial azelastine hydrochloride nasal spray and fluticasone propionate nasal spray significantly improved nasal symptoms of seasonal allergic rhinitis compared with either agent alone. To compare an azelastine-fluticasone combination nasal spray administered in a single-delivery device with a commercially available azelastine nasal spray and fluticasone nasal spray. This 14-day, multicenter, randomized, double-blind study was conducted during the Texas mountain cedar season. After a 5-day placebo lead-in, 610 patients with moderate-to-severe nasal symptoms were randomized to treatment with (1) azelastine nasal spray, (2) fluticasone nasal spray, (3) combination azelastine and fluticasone nasal spray, or (4) placebo nasal spray. All treatments were given as 1 spray per nostril twice daily. The primary efficacy variable was the change from baseline in the total nasal symptom score (TNSS), consisting of nasal congestion, runny nose, itchy nose, and sneezing. All 3 active groups were statistically superior (P spray provided statistically significant improvement in the TNSS and additive clinical benefit compared with either agent alone in patients with moderate-to-severe seasonal allergic rhinitis. clinicaltrials.gov Identifier: NCT00660517. Copyright 2010 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  3. Numerical Simulation and Experimental Characterization of a Binary Aluminum Alloy Spray - Application to the Spray Rolling Process

    SciTech Connect

    S. B. Johnson; J.-P. Delplanque; Y. Lin; Y. Zhou; E. J. Lavernia; K. M. McHugh

    2005-02-01

    A stochastic, droplet-resolved model has been developed to describe the behavior of a binary aluminum alloy spray during the spray-rolling process. In this process, a molten aluminum alloy is atomized and the resulting spray is depostied on the rolls of a twin-roll caster to produce aluminum strip. The one-way coupled spray model allows the prediction of spray characteristics such as enthalph and solid fraction, and their distribution between the nozzle and the depostion surface. This paper outlines the model development and compares the predicted spray dynamics to PDI measurements performed in a controlled configuration. Predicted and measured droplet velocity and size distributions are presented for two points along the spray centerline along with predicted spray averaged specific enthalph and solid fraction curves.

  4. Mechanised spraying device a novel technology for spraying fire protective coating material in the benches of opencast coal mines for preventing spontaneous combustion

    SciTech Connect

    R.V.K. Singh; V.K. Singh

    2004-10-15

    Spontaneous combustion in coal mines plays a vital role in occurrences of fire. Fire in coal, particularly in opencast mines, not only causes irreparable loss of national wealth but damages the surface structure and pollutes the environment. The problem of spontaneous combustion/fire in opencast coal benches is acute. Presently over 75% of the total production of coal in Indian mines is being carried out by opencast mining. Accordingly a mechanised spraying device has been developed for spraying the fire protective coating material for preventing spontaneous combustion in coal benches of opencast mines jointly by Central Mining Research Institute, Dhanbad and M/s Signum Fire Protection (India) Pvt. Ltd., Nagpur under Science & Technology (S&T) project funded by Ministry of Coal, Govt. of India. The objective of this paper is to describe in detail about the mechanised spraying device and its application for spraying fire protective coating material in the benches of opencast coal mines for preventing spontaneous combustion/fire.

  5. A newly designed ultrasonic spray pyrolysis device to fabricate YBCO tapes

    NASA Astrophysics Data System (ADS)

    Liu, M.; Zhou, M. L.; Zhai, L. H.; Liu, D. M.; Gao, X.; Liu, W.

    2003-04-01

    A newly designed ultrasonic spray pyrolysis device has been manufactured to fabricate YBCO tapes. The apparatus is primarily composed of four zones: the ultrasonic generator, the atomization chamber, the pyrolysis chamber and the rotating equipment. Every part of them is designed and fabricated by us. The whole system costs far less than the ready-made equipment facility in which there is always a vacuum apparatus. This apparatus with processing parameters accurately controlled can fabricate short and long YBCO tapes. In this paper, we mainly focused on how to design and manufacture four parts of the ultrasonic spray pyrolysis. We have deposited c-axis aligned short YBCO tapes on biaxially textured Ag {1 1 0}<1 1 0> substrates with Jc=10 3 A/cm 2 using this method with our device. The method is very promising in terms of its precise control of metal compositions, high deposition rate and low cost non-vacuum approach. Improvements of this technique are being carried out to fabricate long YBCO tapes.

  6. Controllable Electrochromic Polyamide Film and Device Produced by Facile Ultrasonic Spray-coating.

    PubMed

    Liu, Huan-Shen; Chang, Wei-Chieh; Chou, Chin-Yen; Pan, Bo-Cheng; Chou, Yi-Shan; Liou, Guey-Sheng; Liu, Cheng-Liang

    2017-09-20

    Thermally stable TPA-OMe polyamide films with high transmittance modulation in response to applied potential are formed by facile ultrasonic spray-coating. Four processing conditions (Film A, Film B, Film C and Film D) through tuning both solution concentrations and deposition temperatures can be utilized for the formation of wet and dry deposited films with two film thickness intervals. The electrochromic results show that the dry deposited rough films at higher deposition temperature generally reveal a faster electrochromic response, lower charge requirements (Q) and less conspicuous color changes (smaller optical density change (ΔOD) and lightness change (ΔL*)) during the oxidation process as compared to the wet deposited smooth films at lower deposition temperature. Moreover, thicker electrochromic films from increased solution concentration exhibit more obvious changes between coloration and bleaching transition. All these four polyamide films display colorless-to-turquoise electrochromic switching with good redox stability. The large scale patterned electrochromic film and its application for assembled device (10 × 10 cm(2) in size) are also produced and reversibly operated for color changes. These represent a major solution-processing technique produced by ultrasonic spray-coating method towards scalable and cost-effective production, allowing more freedoms to facilitate the designed electrochromic devices as required.

  7. An experimental investigation on spray characteristics emanating from liquid-liquid coaxial swirl atomizer

    NASA Astrophysics Data System (ADS)

    Rashid, Mohd Syazwan Firdaus Mat; Hamid, Ahmad Hussein Abdul; Ghaffar, Zulkifli Abdul; Zaki, Khairil Azizi Mohamad

    2012-06-01

    Liquid fuel/oxidizer atomization is extensively used in rocket engines for exploiting their high mixing efficiency. An experimental investigation is performed to explore the characteristics of sprays produced by a liquid-liquid coaxial swirl atomizer in a non-combusting environment. Investigation data will be used to correlate between liquid properties, atomizer geometric dimension, and atomization spray characterization. The idea is design the atomizer, fabricate, cold flow test and analyze the result. This atomizer is divided into two parts which is the inner atomizer and the outer atomizer. There also has two liquid inlet points where one inlet is meant for inner nozzle while the other inlet is meant for the outer nozzle. Two water supplies of the same kind will be supplied into the atomizer. As compared to basic conventional atomizer design, this atomizer sprays two liquid simultaneously at different angles and different swirl directions, but at the same axis. In this paper, it described the characteristics of spray for outer and inner atomizer. As the result, it was found that the outer atomizer have high value of spray cone angle compared to inner atomizer.

  8. Lidocaine 10% spray to the cervix reduces pain during intrauterine device insertion: a double-blind randomised controlled trial.

    PubMed

    Aksoy, Hüseyin; Aksoy, Ülkü; Ozyurt, Sezin; Açmaz, Gökhan; Babayigit, Mustafa

    2016-04-01

    Fear of pain during intrauterine device (IUD) insertion can be a barrier to widespread use of this safe and highly effective contraceptive method. Our objective was to determine the effectiveness of topical 10% lidocaine spray for pain control during IUD insertion. A total of 200 subjects with the request for IUD insertion were included in the study. The patients were randomly divided into two groups: lidocaine spray (n=100) and placebo (n=100). The pain experienced during the procedure was measured immediately after insertion by a standard Visual Analogue Scale (VAS) administered by a separate researcher with maintenance of allocation concealment. The mean pain score during the procedure was 1.01±1.20 in the lidocaine spray group and 3.23±1.60 in the placebo spray group (p<0.001). Lidocaine spray treatment significantly lowered the overall procedural pain score compared with placebo. Significant pain reduction during IUD insertion can be achieved by using 10% lidocaine spray alone. Lidocaine spray can be accepted as a non-invasive, easy to apply and more comfortable local anaesthetic method for IUD insertion. NCT02020551. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  9. Computational and Experimental Investigation of Interfacial Area in Near-Field Diesel Spray Simulations

    DOE PAGES

    Pandal, Adrian; Pastor, Jose Marie; Kastengren, A.; ...

    2017-03-28

    The dense spray region in the near-field of diesel fuel injection remains an enigma. This region is difficult to interrogate with light in the visible range and difficult to model due to the rapid interaction between liquid and gas. In particular, modeling strategies that rely on Lagrangian particle tracking of droplets have struggled in this area. To better represent the strong interaction between phases, Eulerian modeling has proven particularly useful. Models built on the concept of surface area density are advantageous where primary and secondary atomization have not yet produced droplets, but rather form more complicated liquid structures. Surface areamore » density, a more general concept than Lagrangian droplets, naturally represents liquid structures, no matter how complex. These surface area density models, however, have not been directly experimentally validated in the past due to the inability of optical methods to elucidate such a quantity. Optical diagnostics traditionally measure near-spherical droplet size far downstream, where the spray is optically thin. Using ultra-small-angle x-ray scattering (USAXS) measurements to measure the surface area and x-ray radiography to measure the density, we have been able to test one of the more speculative parts of Eulerian spray modeling. The modeling and experimental results have been combined to provide insight into near-field spray dynamics.« less

  10. Computational and Experimental Investigation of Interfacial Area in Near-Field Diesel Spray Simulation

    DOE PAGES

    Pandal, Adrian; Pastor, Jose M.; Payri, Raul; ...

    2017-03-28

    The dense spray region in the near-field of diesel fuel injection remains an enigma. This region is difficult to interrogate with light in the visible range and difficult to model due to the rapid interaction between liquid and gas. In particular, modeling strategies that rely on Lagrangian particle tracking of droplets have struggled in this area. To better represent the strong interaction between phases, Eulerian modeling has proven particularly useful. Models built on the concept of surface area density are advantageous where primary and secondary atomization have not yet produced droplets, but rather form more complicated liquid structures. Surface areamore » density, a more general concept than Lagrangian droplets, naturally represents liquid structures, no matter how complex. These surface area density models, however, have not been directly experimentally validated in the past due to the inability of optical methods to elucidate such a quantity. Optical diagnostics traditionally measure near-spherical droplet size far downstream, where the spray is optically thin. Using ultra-small-angle x-ray scattering (USAXS) measurements to measure the surface area and x-ray radiography to measure the density, we have been able to test one of the more speculative parts of Eulerian spray modeling. In conclusion, the modeling and experimental results have been combined to provide insight into near-field spray dynamics.« less

  11. Experimental study on spray characteristics of alternate jet fuels using Phase Doppler Anemometry

    NASA Astrophysics Data System (ADS)

    Kannaiyan, Kumaran; Sadr, Reza

    2013-11-01

    Gas-to-Liquid (GTL) fuels have gained global attention due to their cleaner combustion characteristics. The chemical and physical properties of GTL jet fuels are different from conventional jet fuels owing to the difference in their production methodology. It is important to study the spray characteristics of GTL jet fuels as the change of physical properties can affect atomization, mixing, evaporation and combustion process, ultimately affecting emission process. In this work, spray characteristics of two GTL synthetic jet fuels are studied using a pressure-swirl nozzle at different injection pressures and atmospheric ambient condition. Phase Doppler Anemometry (PDA) measurements of droplet size and velocity are compared with those of regular Jet A-1 fuel at several axial and radial locations downstream of the nozzle exit. Experimental results show that although the GTL fuels have different physical properties such as viscosity, density, and surface tension, among each other the resultant change in the spray characteristics is insignificant. Furthermore, the presented results show that GTL fuel spray characteristics exhibit close similarity to those of Jet A-1 fuel. Funded by Qatar Science and Technology Park.

  12. Numerical modeling and experimental measurements of water spray impact and transport over a cylinder.

    SciTech Connect

    Avedisian, C. T.; Presser, Cary; DesJardin, Paul Edward; Hewson, John C.; Yoon, Sam Sukgoo

    2005-03-01

    This study compares experimental measurements and numerical simulations of liquid droplets over heated (to a near surface temperature of 423 K) and unheated cylinders. The numerical model is based on an unsteady Reynolds-averaged Navier-Stokes (RANS) formulation using a stochastic separated flow (SSF) approach for the droplets that includes submodels for droplet dispersion, heat and mass transfer, and impact on a solid surface. The details of the droplet impact model are presented and the model is used to simulate water spray impingement on a cylinder. Computational results are compared with experimental measurements using phase Doppler interferometry (PDI).

  13. Selective Laser Treatment on Cold-Sprayed Titanium Coatings: Numerical Modeling and Experimental Analysis

    NASA Astrophysics Data System (ADS)

    Carlone, Pierpaolo; Astarita, Antonello; Rubino, Felice; Pasquino, Nicola; Aprea, Paolo

    2016-12-01

    In this paper, a selective laser post-deposition on pure grade II titanium coatings, cold-sprayed on AA2024-T3 sheets, was experimentally and numerically investigated. Morphological features, microstructure, and chemical composition of the treated zone were assessed by means of optical microscopy, scanning electron microscopy, and energy dispersive X-ray spectrometry. Microhardness measurements were also carried out to evaluate the mechanical properties of the coating. A numerical model of the laser treatment was implemented and solved to simulate the process and discuss the experimental outcomes. Obtained results highlighted the key role played by heat input and dimensional features on the effectiveness of the treatment.

  14. An Experimental and Finite Element Study of Cold Spray Copper Impact onto Two Aluminum Substrates

    NASA Astrophysics Data System (ADS)

    King, Peter C.; Bae, Gyuyeol; Zahiri, Saden H.; Jahedi, Mahnaz; Lee, Changhee

    2010-03-01

    The effect of cold spray temperature and substrate hardness on particle deformation and adhesion has been studied, with particular emphasis on adiabatic shearing leading to melting. Copper particles were cold sprayed onto commercial purity (CP) aluminum and alloy 7050-T7451, with stagnation temperatures 200, 400, and 600 °C. Deposition efficiency, assisted by particle embedding, increased with temperature and was higher on the softer CP substrate. Crater surfaces, adhered particles, and interfaces were characterized by scanning electron microscopy, focused ion beam, and transmission electron microscopy. For comparison, the impact of 15 μm Cu particles was simulated using finite element modeling. A thin layer of material on the substrate-side of the interface was predicted to reach melting point on both substrates at higher impact velocities. Formation of a molten layer was found experimentally. At 600 °C, the effect of substrate heating by the gas jet could not be ignored.

  15. A constant volume diesel spray combustion facility and the corresponding experimental diagnostics

    NASA Astrophysics Data System (ADS)

    Labs, J. E.; Filley, J.; Jepsen, E.; Parker, T. E.

    2005-03-01

    A facility was built to examine the diesel spray/combustion process. The facility centers around a constant volume vessel, which consists of a visible and infrared optically accessible cold-wall, heated-interior pressure vessel coupled to an injection system. The combustion vessel is capable of operation at 50atm and 1000K (before injection), was used to simulate preinjection diesel in-cylinder conditions, and was coupled to a repeatable (for each fuel type), single shot, high pressure, metering fuel injection system. A number of experimental diagnostics have been applied to the facility and will be briefly discussed and examples of typical results offered. These diagnostics include: extractive post-combustion gas concentration experiments, droplet sizing measurements, and emission/absorption temperature measurements. Results from this facility capture the critical aspects of diesel spray combustion but do not include the change in pressure associated with heat release in a small volume and volume expansion due to piston motion.

  16. Splat formation during thermal spraying of polymer particles: Mathematical modeling and experimental analysis

    NASA Astrophysics Data System (ADS)

    Ivosevic, Milan

    This thesis develops and presents a model for predicting the three-dimensional splat formation process for polymer particles under High Velocity Oxy-Fuel (HVOF) combustion spray process conditions. During HVOF spray deposition, jets of high temperature, high velocity gases are used to heat, melt and accelerate particulate materials injected into the jet and propel them towards a surface to be coated. Upon impact at the surface, multiple hot particles impact and form splats that overlap, cool and consolidate to form a coating. These splats are the building blocks of an HVOF coating and coating characteristics such as porosity, roughness, adhesive and cohesive strengths depend on the morphology of these splats and how they bond to the substrate and to each other. Fully coupled transport models of particle acceleration and heating in an HVOF jet were simultaneously integrated within a FORTRAN code to predict particle velocity and particle temperature profiles at impact. Then, a volume-of-fluid computational fluid mechanics package, Flow-3DRTM, was used to predict particle deformation and splat shapes using results from the acceleration and heating models as the initial conditions. Fluid flow of spreading polymer droplets was modeled as a generalized Newtonian fluid with temperature and shear rate dependent viscosity. While shear thinning primarily affected the droplet spreading ratio, the internal temperature distribution had the largest effect on the final splat shape, particularly when particles were partially melted. The predicted shapes of deformed particles exhibited good qualitative agreement with experimentally observed splats. Most of the larger experimentally observed (> 70 mum) Nylon-11 splats sprayed onto room temperature flat or rough substrates exhibited a characteristic "fried-egg" shape with a large, nearly-hemispherical, core in the center of a thin disk. This shape was formed from polymer particles having a low temperature, high viscosity core and a

  17. Atmospheric Spray Freeze-Drying: Numerical Modeling and Comparison With Experimental Measurements.

    PubMed

    Borges Sebastião, Israel; Robinson, Thomas D; Alexeenko, Alina

    2017-01-01

    Atmospheric spray freeze-drying (ASFD) represents a novel approach to dry thermosensitive solutions via sublimation. Tests conducted with a second-generation ASFD equipment, developed for pharmaceutical applications, have focused initially on producing a light, fine, high-grade powder consistently and reliably. To better understand the heat and mass transfer physics and drying dynamics taking place within the ASFD chamber, 3 analytical models describing the key processes are developed and validated. First, by coupling the dynamics and heat transfer of single droplets sprayed into the chamber, the velocity, temperature, and phase change evolutions of these droplets are estimated for actual operational conditions. This model reveals that, under typical operational conditions, the sprayed droplets require less than 100 ms to freeze. Second, because understanding the heat transfer throughout the entire freeze-drying process is so important, a theoretical model is proposed to predict the time evolution of the chamber gas temperature. Finally, a drying model, calibrated with hygrometer measurements, is used to estimate the total time required to achieve a predefined final moisture content. Results from these models are compared with experimental data.

  18. Microfluidic supercritical antisolvent continuous processing and direct spray-coating of poly(3-hexylthiophene) nanoparticles for OFET devices.

    PubMed

    Couto, Ricardo; Chambon, Sylvain; Aymonier, Cyril; Mignard, Emmanuel; Pavageau, Bertrand; Erriguible, Arnaud; Marre, Samuel

    2015-01-21

    We report for the first time the use of a microfluidic supercritical antisolvent process (μSAS) to synthesize semiconducting polymer nanoparticles (NPs) of poly(3-hexylthiophene) (P3HT). Solvent-free P3HT NPs with average diameters as small as 36 ± 8 nm are obtained. They are continuously spray-coated on substrates to fabricate OFET devices, demonstrating hole mobility through the nanoparticle film equivalent to that of conventional spin-coated P3HT.

  19. Spray-painted binder-free SnSe electrodes for high-performance energy-storage devices.

    PubMed

    Wang, Xianfu; Liu, Bin; Xiang, Qingyi; Wang, Qiufan; Hou, Xiaojuan; Chen, Di; Shen, Guozhen

    2014-01-01

    SnSe nanocrystal electrodes on three-dimensional (3D) carbon fabric and Au-coated polyethylene terephthalate (PET) wafer have been prepared by a simple spray-painting process and were further investigated as binder-free active-electrodes for Lithium-ion batteries (LIBs) and flexible stacked all-solid-state supercapacitors. The as-painted SnSe nanocrystals/carbon fabric electrodes exhibit an outstanding capacity of 676 mAh g(-1) after 80 cycles at a current density of 200 mA g(-1) and a considerable high-rate capability in lithium storage because of the excellent ion transport from the electrolyte to the active materials and the efficient charge transport between current collector and electrode materials. The binder-free electrodes also provide a larger electrochemical active surface compared with electrodes containing binders, which leads to the enhanced capacities of energy-storage devices. A flexible stacked all-solid-state supercapacitor based on the SnSe nanocrystals on Au-coated PET wafers shows high capacitance reversibility with little performance degradation at different current densities after 2200 charge-discharge cycles and even when bent. This allows for many potential applications in facile, cost-effective, spray-paintable, and flexible energy-storage devices. The results indicate that the fabrication of binder-free electrodes by a spray painting process is an interesting direction for the preparation of high-performance energy-storage devices.

  20. Evaluation of droplet velocity and size from nasal spray devices using phase Doppler anemometry (PDA).

    PubMed

    Liu, Xiaofei; Doub, William H; Guo, Changning

    2010-03-30

    To determine aerosol deposition during the inhalation drug delivery, it is important to understand the combination of velocity and droplet size together. In this study, phase Doppler anemometry (PDA) was used to simultaneously characterize the aerosol velocity and droplet size distribution (DSD) of three nasal spray pumps filled with water. Thirteen sampling positions were located in the horizontal cross-sectional area of the nasal spray plumes at a distance of 3cm from the pump orifice. The results showed droplet velocities near the center of the spray plume were higher and more consistent than those near the edge. The pumps examined showed significant differences in their aerosol velocity at the center of the spray plume, which suggest that this metric might be used as a discriminating parameter for in vitro testing of nasal sprays. Droplet size measurements performed using PDA were compared with results from laser light scattering measurements. The ability of PDA to provide simultaneous measurements of aerosol velocity and size makes it a powerful tool for the detailed investigation of nasal spray plume characteristics.

  1. Nanosized aerosols from consumer sprays: experimental analysis and exposure modeling for four commercial products

    NASA Astrophysics Data System (ADS)

    Lorenz, Christiane; Hagendorfer, Harald; von Goetz, Natalie; Kaegi, Ralf; Gehrig, Robert; Ulrich, Andrea; Scheringer, Martin; Hungerbühler, Konrad

    2011-08-01

    Consumer spray products are already on the market in the cosmetics and household sector, which suggest by their label that they contain engineered nanoparticles (ENP). Sprays are considered critical for human health, because the lungs represent a major route for the uptake of ENP into the human body. To contribute to the exposure assessment of ENP in consumer spray products, we analyzed ENP in four commercially available sprays: one antiperspirant, two shoe impregnation sprays, and one plant-strengthening agent. The spray dispersions were analyzed by inductively coupled plasma mass spectrometry (ICPMS) and (scanning-) transmission electron microscopy ((S)TEM). Aerosols were generated by using the original vessels, and analyzed by scanning mobility particle sizer (SMPS) and (S)TEM. On the basis of SMPS results, the nanosized aerosol depositing in the respiratory tract was modeled for female and male consumers. The derived exposure levels reflect a single spray application. We identified ENP in the dispersions of two products (shoe impregnation and plant spray). Nanosized aerosols were observed in three products that contained propellant gas. The aerosol number concentration increased linearly with the sprayed amount, with the highest concentration resulting from the antiperspirant. Modeled aerosol exposure levels were in the range of 1010 nanosized aerosol components per person and application event for the antiperspirant and the impregnation sprays, with the largest fraction of nanosized aerosol depositing in the alveolar region. Negligible exposure from the application of the plant spray (pump spray) was observed.

  2. Arc spraying in China

    NASA Astrophysics Data System (ADS)

    Liu, Xianjun

    2001-03-01

    Although are spraying is not a new technique, recent development of arc spraying device systems, spray wires, research on the coating mechanism, and the dynamic behavior of spraying make it a most active thermal spray process. In China, the arc spraying technique is the most efficient way for long life corrosion protection of steel structures. In addition, the arc spraying process is widely used for renovation and surface modification of machine components, mold making for plastic products, high-temperature corrosion resistance for waterwalls of boilers, antisliding coatings, self-lubricating coatings, etc.

  3. High-rate production of functional nanostructured films and devices by coupling flame spray pyrolysis with supersonic expansion.

    PubMed

    Wegner, K; Vinati, S; Piseri, P; Antonini, A; Zelioli, A; Barborini, E; Ducati, C; Milani, P

    2012-05-11

    The fabrication of functional thin films and devices by direct deposition of nanoparticles from the gas phase is a promising approach enabling, for instance, the integration of complex analytical and sensing capabilities on microfabricated platforms. Aerosol-based techniques ensure large-scale nanoparticle production and they are potentially suited for this goal. However, they are not adequate in terms of fine control over the lateral resolution of the coatings, mild processing conditions (avoiding high temperature and aggressive chemicals), low contamination and compatibility with microfabrication processes. Here we report the high-rate and efficient production of functional nanostructured films by nanoparticle assembling obtained by the combination of flame spray pyrolysis and supersonic expansion. Our approach merges the advantages of flame spray pyrolysis for bulk nanopowders such as process stability and wide material library availability with those of supersonic cluster beam deposition in terms of lateral resolution and of direct integration of nanomaterials on devices. We efficiently produced nanostructured films and devices (such as gas sensors) using metal oxide, pure noble metal and oxide-supported noble metal nanoparticles.

  4. Characterization of anti-theft devices directly from the surface of banknotes via easy ambient sonic spray ionization mass spectrometry.

    PubMed

    Schmidt, Eduardo Morgado; Franco, Marcos Fernando; Cuelbas, Claudio José; Zacca, Jorge Jardim; de Carvalho Rocha, Werickson Fortunato; Borges, Rodrigo; de Souza, Wanderley; Sawaya, Alexandra Christine Helena Frankland; Eberlin, Marcos Nogueira; Correa, Deleon Nascimento

    2015-09-01

    Using Brazilian banknotes as a test case, forensic examination and identification of Rhodamine B dye anti-theft device (ATD) staining on banknotes were performed. Easy ambient sonic spray ionization mass spectrometry (EASI-MS) was used since it allows fast and simple analysis with no sample preparation providing molecular screening of the surface with direct desorption and ionization of the security dye. For a more accurate molecular characterization of the ATD dye, Q Exactive Orbitrap™ Fourier transform (tandem) mass spectrometry using eletrospray ionization (ESI-HRMS/MS) was also applied.

  5. Spray atomization and combustion

    NASA Technical Reports Server (NTRS)

    Faeth, G. M.

    1986-01-01

    New theoretical and experimental methods for studying sprays are reviewed. Common methods to analyze dilute sprays are described and used to interpret recent measurements of the structure of dilute sprays and related dispersed turbulent jets. Particle-laden jets, nonevaporating, evaporating, and combusting sprays, and noncondensing and condensing bubbly jets are examined and used to initially evaluate current analytical methods for a wide range of conditions. Dense sprays are briefly discussed.

  6. Experimental device for measuring the momentum of disperse granular materials

    SciTech Connect

    Watling, H.E.; Griffiths, S.K.

    1982-02-10

    An experimental device for measuring the time averaged momentum associated with a steady stream of a disperse granular material has been developed. The mathematical basis for the device is presented including a discussion of using the momentum measurement to compute the local mass or energy fluxes. The analysis considers both nonuniform particle mass and nonuniform velocities for the various constituents of an aggregate material. The results of calibration experiments conducted with a prototype transducer are shown with theoretical predictions of these results.

  7. Elucidation of Formulation and Delivery Device-Related Effects on In Vitro Performance of Nasal Spray with Implication to Rational Product Specification Identification.

    PubMed

    Grmaš, Jernej; Stare, Katarina; Božič, Dane; Injac, Rade; Dreu, Rok

    2017-08-01

    The aim of this work is to use an experimental design approach to identify and study influential formulation and delivery device properties, which can be controlled by final product manufacturer, to establish design space, within which desired in vitro performance can be reached. Combining three factors, viscosity of suspension, nozzle orifice diameter (OD), and shot weight (SW), at three levels resulted in D-optimal experimental design with 20 runs. Responses within this study were droplet size distribution (DSD) and spray pattern (SP) in vitro tests. In addition, the amount of mechanical work needed for actuation was integrated from force profiles and used as a response. Results were fit to quadratic model by regression, which allowed also for determination of second-order and interaction effects between factors. Models were further optimized by keeping significant terms only. Optimized models were used to create response surfaces and design space with confidence levels. Viscosity has a dominant effect on DSD and modest effect on SP, with lower viscosities related to generation of smaller DSD and larger SP. Orifice diameter was found to have the highest impact on SP, with larger diameter resulting in larger SP. This effect was additionally confirmed by results of Plume Geometry in vitro test. Shot weight factor exerts significant influence on all tested metrics. Work, however, did not vary greatly with suspension viscosity or orifice diameter. Shot weight is the most dominant factor for work and important for DSD having a positive effect on both responses. In the case of SP, its relationship with shot weight is described by second-order polynomial fit. Inspection of raw data revealed that density of droplets within SP area is different for different shot weights. Presented study elucidated an inherent relationship between factors and responses and established mathematical models (response surfaces) for predictive purposes to target specific in vitro performance

  8. A simplified analytical model for dc plasma spray torch: influence of gas properties and experimental conditions

    NASA Astrophysics Data System (ADS)

    Rat, V.; Coudert, J. F.

    2006-11-01

    A simplified analytical model is proposed to evaluate some characteristics of the arc jet generated with a dc plasma torch, in the restricted area of atmospheric plasma spraying conditions. The plasma inside the anode nozzle is considered as stationary and is divided into the arc column and a surrounding cold layer which electrically insulates the plasma from the nozzle wall. Radiation and processes related to the arc attachment at the electrodes are not explicitly taken into account. Heat conduction is evaluated by using Kirchoff's potential, which is described, as it is done also for the electrical conductivity, as a function of the gas specific enthalpy instead of temperature. The model is used to calculate the specific enthalpy radial distribution. From that, and by introducing a mean isentropic coefficient, it is possible to calculate the axial velocity of the plasma jet at the nozzle exit and to evaluate the different pressure contributions. The comparison between predicted and previously measured plasma jet velocities shows good agreement for various experimental conditions.

  9. Parametric Appraisal of Process Parameters for Adhesion of Plasma Sprayed Nanostructured YSZ Coatings Using Taguchi Experimental Design

    PubMed Central

    Mantry, Sisir; Mishra, Barada K.; Chakraborty, Madhusudan

    2013-01-01

    This paper presents the application of the Taguchi experimental design in developing nanostructured yittria stabilized zirconia (YSZ) coatings by plasma spraying process. This paper depicts dependence of adhesion strength of as-sprayed nanostructured YSZ coatings on various process parameters, and effect of those process parameters on performance output has been studied using Taguchi's L16 orthogonal array design. Particle velocities prior to impacting the substrate, stand-off-distance, and particle temperature are found to be the most significant parameter affecting the bond strength. To achieve retention of nanostructure, molten state of nanoagglomerates (temperature and velocity) has been monitored using particle diagnostics tool. Maximum adhesion strength of 40.56 MPa has been experimentally found out by selecting optimum levels of selected factors. The enhanced bond strength of nano-YSZ coating may be attributed to higher interfacial toughness due to cracks being interrupted by adherent nanozones. PMID:24288490

  10. Experimental Study on the Electrochemical Anti-Corrosion Properties of Steel Structures Applying the Arc Thermal Metal Spraying Method

    PubMed Central

    Choe, Hong-Bok; Lee, Han-Seung; Shin, Jun-Ho

    2014-01-01

    The arc thermal metal spraying method (ATMSM) provides proven long-term protective coating systems using zinc, aluminum and their alloys for steel work in a marine environment. This paper focuses on studying experimentally the anti-corrosion criteria of ATMSM on steel specimens. The effects of the types of spraying metal and the presence or absence of sealing treatment from the thermal spraying of film on the anti-corrosion performance of TMSM were quantitatively evaluated by electrochemical techniques. The results showed that ATMSM represented a sufficient corrosion resistance with the driving force based on the potential difference of more than approximately 0.60 V between the thermal spraying layer and the base substrate steel. Furthermore, it was found that the sealing treatment of specimens had suppressed the dissolution of metals, increased the corrosion potential, decreased the corrosion current density and increased the polarization resistance. Metal alloy Al–Mg (95%:5%) by mass with epoxy sealing coating led to the most successful anti-corrosion performance in these electrochemical experiments. PMID:28788271

  11. Experimental evaluation of a mathematical model for predicting transfer efficiency of a high volume-low pressure air spray gun.

    PubMed

    Tan, Y M; Flynn, M R

    2000-10-01

    The transfer efficiency of a spray-painting gun is defined as the amount of coating applied to the workpiece divided by the amount sprayed. Characterizing this transfer process allows for accurate estimation of the overspray generation rate, which is important for determining a spray painter's exposure to airborne contaminants. This study presents an experimental evaluation of a mathematical model for predicting the transfer efficiency of a high volume-low pressure spray gun. The effects of gun-to-surface distance and nozzle pressure on the agreement between the transfer efficiency measurement and prediction were examined. Wind tunnel studies and non-volatile vacuum pump oil in place of commercial paint were used to determine transfer efficiency at nine gun-to-surface distances and four nozzle pressure levels. The mathematical model successfully predicts transfer efficiency within the uncertainty limits. The least squares regression between measured and predicted transfer efficiency has a slope of 0.83 and an intercept of 0.12 (R2 = 0.98). Two correction factors were determined to improve the mathematical model. At higher nozzle pressure settings, 6.5 psig and 5.5 psig, the correction factor is a function of both gun-to-surface distance and nozzle pressure level. At lower nozzle pressures, 4 psig and 2.75 psig, gun-to-surface distance slightly influences the correction factor, while nozzle pressure has no discernible effect.

  12. Numerical and Experimental Research of Temperature of Arc Spray Zn-Al Alloy Droplets

    NASA Astrophysics Data System (ADS)

    Yiqing, Wang; Zhongyun, He; Wanhua, Zhao; Jun, Hong; Bingheng, Lu

    2010-03-01

    In this paper, a model for arc spraying Zn-Al droplets during flight course has been established and developed using theoretical principles of fluid mechanics, heat transfer and phase transition. Mathematical models are set up to describe the interaction between air current and droplets in flight. The calculation results showed that Zn-Al droplet's velocity and temperature are the function of flight distance and droplet's diameter. Percentage of solid droplets in metal spray is a function of droplet's size distribution. Within a flight distance of 600 mm, depending on the size and cooling rate, the droplets in metal spray may be in the states of entirely liquid, partially solidified, or entirely solidified and the percentage of partially solidified and entirely solidified droplets in metal spray is less than 2%.

  13. Spray Chemical Vapor Deposition of CulnS2 Thin Films for Application in Solar Cell Devices

    NASA Technical Reports Server (NTRS)

    Hollingsworth, Jennifer A.; Buhro, William E.; Hepp, Aloysius F.; Jenkins. Philip P.; Stan, Mark A.

    1998-01-01

    Chalcopyrite CuInS2 is a direct band gap semiconductor (1.5 eV) that has potential applications in photovoltaic thin film and photoelectrochemical devices. We have successfully employed spray chemical vapor deposition using the previously known, single-source, metalorganic precursor, (Ph3P)2CuIn(SEt)4, to deposit CuInS2 thin films. Stoichiometric, polycrystalline films were deposited onto fused silica over a range of temperatures (300-400 C). Morphology was observed to vary with temperature: spheroidal features were obtained at lower temperatures and angular features at 400 C. At even higher temperatures (500 C), a Cu-deficient phase, CuIn5S8, was obtained as a single phase. The CuInS2 films were determined to have a direct band gap of ca. 1.4 eV.

  14. Experimental Testing and Numerical Modeling of Spray Cooling Under Terrestrial Gravity Conditions

    DTIC Science & Technology

    2005-01-01

    is useful to effectively deal with waste heat generated in space -based platforms, such as the International Space Station or shuttle orbiter, as... McQuillen , J., “Design of a Microgravity Spray Cooling Experiment,” 42nd AIAA Aerospace Sciences Conference and Exhibit, 2004. Carslaw, H., Jaeger J...Transfer Characteristics of Spray Cooling in a Closed Loop,” International Journal of Heat and Mass Transfer 46, pp. 3737-3746, 2003. 106 Lin

  15. Experimental Studies of Spray Deposition on a Flat Surface in a Vacuum Environment

    NASA Technical Reports Server (NTRS)

    Golliher, Eric L.; Yao, S. C.

    2015-01-01

    Cooling of spacecraft components in the space environment is an on-going research effort. The electronics used in modern spacecraft are always changing and the heat flux is increasing. New, one-of-a-kind missions require new approaches to thermal control. In this research, under vacuum conditions, a pulsed water spray impinged on a small disc, while a high speed data acquisition system recorded the temperature histories of this copper disc. The water droplets froze quickly and accumulated on the disc as the spray continued. After the spray stopped, the frozen water that remained on the disc then sublimated into the vacuum environment and cooled the disc. This paper examines two important aspects of this process: 1) the difference in spray start up and shutdown in a vacuum environment versus in a standard atmospheric pressure environment, and 2) the water utilization efficiency in a vacuum environment due to the effects of drop trajectories and drop bouncing on the surface. Both phenomena play a role during spray cooling in a vacuum. This knowledge should help spacecraft designers plan for spray cooling as an option to cool spacecraft electronics, human metabolic generated heat, and heat from other sources.

  16. High-temperature thermo-mechanical behavior of functionally graded materials produced by plasma sprayed coating: Experimental and modeling results

    NASA Astrophysics Data System (ADS)

    Choi, Kang Hyun; Kim, Hyun-Su; Park, Chang Hyun; Kim, Gon-Ho; Baik, Kyoung Ho; Lee, Sung Ho; Kim, Taehyung; Kim, Hyoung Seop

    2016-09-01

    Thermal barrier coatings are widely used in aerospace industries to protect exterior surfaces from harsh environments. In this study, functionally graded materials (FGMs) were investigated with the aim to optimize their high temperature resistance and strength characteristics. NiCrAlY bond coats were deposited on Inconel-617 superalloy substrate specimens by the low vacuum plasma spraying technique. Functionally graded Ni-yttria-stabilized zirconia (YSZ) coatings with gradually varying amounts of YSZ (20%-100%) were fabricated from composite powders by vacuum plasma spraying. Heat shield performance tests were conducted using a high- temperature plasma torch. The temperature distributions were measured using thermocouples at the interfaces of the FGM layers during the tests. A model for predicting the temperature at the bond coating-substrate interface was established. The temperature distributions simulated using the finite element method agreed well with the experimental results.

  17. Experimental device-independent tests of classical and quantum entropy

    NASA Astrophysics Data System (ADS)

    Zhu, Feng; Zhang, Wei; Chen, Sijing; You, Lixing; Wang, Zhen; Huang, Yidong

    2016-12-01

    In quantum information processing, it is important to witness the entropy of the message in the device-independent way which was proposed recently [R. Chaves, J. B. Brask, and N. Brunner, Phys. Rev. Lett. 115, 110501 (2015), 10.1103/PhysRevLett.115.110501]. In this paper, we theoretically obtain the minimal quantum entropy for three widely used linear dimension witnesses, which is considered "a difficult question." Then we experimentally test the classical and quantum entropy in a device-independent manner. The experimental results agree well with the theoretical analysis, demonstrating that entropy is needed in quantum systems that is lower than the entropy needed in classical systems with the given value of the dimension witness.

  18. Quantification of VOC emissions from paint spraying on a construction site using solid phase microextraction devices.

    PubMed

    Cheng, Wen-Hsi; Huang, Hsiao-Lin; Chen, Kang-Shin; Chang, Yu-Jen

    2017-09-18

    The objective of this study was to measure the emission of, and personal exposure to workers, volatile organic compound (VOC) during paint spraying on a construction site. Needle trap samplers (NTSs), which are a green solid phase microextraction sampling technology, were used to obtain air samples at a large music exhibition center. The standard active sampling method using charcoal tubes and a personal air pump, Method 1501, was simultaneously utilized at the sampling sites to assess the workers' VOC exposures. Analysis of the data thus obtained showed that benzene, toluene, ethylenebenzene, and xylenes (BTEXs) were the main emission compounds. Acetone and isobutyl alcohol, which are used as thinning solvents, were detected as minor emission compounds. The emitted concentrations of most compounds were lower than the legal emission limits in Taiwan except that of benzene, for which the 2-ppm time weighted average short-term exposure limit was exceeded. The packed divinylbenzene (DVB) in the NTS was observed under an environmental scanning electron microscope, and many fine aerosols were found to be deposited on the surface of the DVB adsorbents, causing VOC extraction efficiencies after the fifth sampling in the field to decline. Workers on construction sites should be protected from emissions of VOC and fine particulates to preserve their occupational health.

  19. Evaluating the ergonomics of BCI devices for research and experimentation.

    PubMed

    Ekandem, Joshua I; Davis, Timothy A; Alvarez, Ignacio; James, Melva T; Gilbert, Juan E

    2012-01-01

    The use of brain computer interface (BCI) devices in research and applications has exploded in recent years. Applications such as lie detectors that use functional magnetic resonance imaging (fMRI) to video games controlled using electroencephalography (EEG) are currently in use. These developments, coupled with the emergence of inexpensive commercial BCI headsets, such as the Emotiv EPOC ( http://emotiv.com/index.php ) and the Neurosky MindWave, have also highlighted the need of performing basic ergonomics research since such devices have usability issues, such as comfort during prolonged use, and reduced performance for individuals with common physical attributes, such as long or coarse hair. This paper examines the feasibility of using consumer BCIs in scientific research. In particular, we compare user comfort, experiment preparation time, signal reliability and ease of use in light of individual differences among subjects for two commercially available hardware devices, the Emotiv EPOC and the Neurosky MindWave. Based on these results, we suggest some basic considerations for selecting a commercial BCI for research and experimentation. STATEMENT OF RELEVANCE: Despite increased usage, few studies have examined the usability of commercial BCI hardware. This study assesses usability and experimentation factors of two commercial BCI models, for the purpose of creating basic guidelines for increased usability. Finding that more sensors can be less comfortable and accurate than devices with fewer sensors.

  20. Experimental measurement-device-independent quantum random-number generation

    NASA Astrophysics Data System (ADS)

    Nie, You-Qi; Guan, Jian-Yu; Zhou, Hongyi; Zhang, Qiang; Ma, Xiongfeng; Zhang, Jun; Pan, Jian-Wei

    2016-12-01

    The randomness from a quantum random-number generator (QRNG) relies on the accurate characterization of its devices. However, device imperfections and inaccurate characterizations can result in wrong entropy estimation and bias in practice, which highly affects the genuine randomness generation and may even induce the disappearance of quantum randomness in an extreme case. Here we experimentally demonstrate a measurement-device-independent (MDI) QRNG based on time-bin encoding to achieve certified quantum randomness even when the measurement devices are uncharacterized and untrusted. The MDI-QRNG is randomly switched between the regular randomness generation mode and a test mode, in which four quantum states are randomly prepared to perform measurement tomography in real time. With a clock rate of 25 MHz, the MDI-QRNG generates a final random bit rate of 5.7 kbps. Such implementation with an all-fiber setup provides an approach to construct a fully integrated MDI-QRNG with trusted but error-prone devices in practice.

  1. Experimental Study of the Spray Characteristics of a Research Airblast Atomizer.

    DTIC Science & Technology

    1985-01-01

    diffraction principle. This T2 - , 339-353. instrument uses the Rosin - Rammler weight distribution model. The Rosin - Rammler distribution is defined as 7...stored in the computer memory. The measured SMD was plotted against the air Measurements were made at the center line of the spray mass velocity, liquid to

  2. Experimental Study in a Swirl-Stabilized Combustor with and Without Spray Combustion

    NASA Astrophysics Data System (ADS)

    Ghaffarpour, Mohammad-Reza

    1992-01-01

    To investigate the combustion characteristics and structure of hollow-cone spray flames similar to those occurring in the primary zone of gas turbine combustion chambers, a swirl-stabilized combustor and a water-cooled stainless-steel gas sampling probe were designed. A kerosene spray was generated by a simplex atomizer with a nominal angle of 30 degrees. Swirling air with swirl number of 1.5 was produced from an air swirl plate. Video imaging and photography were employed to document the flame stability and its structure with changes in both design and operating conditions. A Phase Doppler Particle Analyzer (PDPA) was used to measure the drop size, mean and rms values of axial drop velocity and other relevant parameters with and without combustion. Air and fuel flow rates and other conditions were kept identical for reacting and non-reacting cases to investigate effects of combustion alone on the spray. A thermocouple was used to measure the average uncorrected temperature in this turbulent spray flame. A gas chromatograph was also employed to measure the gaseous species concentrations such as hydrogen, oxygen, nitrogen, carbon monoxide, methane, and carbon dioxide in this combustor.

  3. Experimental and numerical evaluation of the performance of supersonic two-stage high-velocity oxy-fuel thermal spray (Warm Spray) gun

    NASA Astrophysics Data System (ADS)

    Katanoda, H.; Morita, H.; Komatsu, M.; Kuroda, S.

    2011-03-01

    The water-cooled supersonic two-stage high-velocity oxy-fuel (HVOF) thermal spray gun was developed to make a coating of temperature-sensitive material, such as titanium, on a substrate. The gun has a combustion chamber (CC) followed by a mixing chamber (MC), in which the combustion gas is mixed with the nitrogen gas at room temperature. The mixed gas is accelerated to supersonic speed through a converging-diverging (C-D) nozzle followed by a straight passage called the barrel. This paper proposes an experimental procedure to estimate the cooling rate of CC, MC and barrel separately. Then, the mathematical model is presented to predict the pressure and temperature in the MC for the specific mass flow rates of fuel, oxygen and nitrogen by assuming chemical equilibrium with water-cooling in the CC and MC, and frozen flow with constant specific heat from stagnant condition to the throat in the CC and MC. Finally, the present mathematical model was validated by comparing the calculated and measured stagnant pressures of the CC of the two-stage HVOF gun.

  4. Automated modular high energy evaluation system for experimental thyristor devices

    NASA Astrophysics Data System (ADS)

    Lacouture, Shelby; Lawson, Kevin; Bayne, Stephen; Giesselmann, Michael; Scozzie, Charles J.; O'Brien, Heather; Ogunniyi, Aderinto A.

    2013-10-01

    A high energy, modular, completely automated test bed with integrated data acquisition and characterization systems was successfully designed in order to perform both safe operating area as well as very high volume reliability testing on experimental silicon carbide Super Gate Turn Off (SGTO) thyristors. Although the system follows a modular design philosophy, with each functional block acting as a peripheral to a main control module and can be adapted to arbitrary power and pulse width levels, for the specific SGTO devices initially evaluated it was configured to have the device discharge variable current levels of up to 6 kA into a 0.5 Ω resistive load with a relatively square pulse fixed at 100 μs full width at half maximum delivering energy levels up to 1.8 kJ to the load.

  5. Numerical simulation and experimental study of explosive projectile devices

    NASA Astrophysics Data System (ADS)

    Selivanov, V. V.; Gryaznov, E. F.; Goldenko, N. A.; Sudomoev, A. D.; Feldstein, V. A.

    2017-06-01

    A study of explosive-throwing device (ETD) was undertaken to simulate the hypervelocity impact of space debris fragments (SDF) and meteoroids with spacecrafts. The principle of operation of an ETD is based on the cumulative effect in combination with the cut-off head of the cumulative jet, which enables one to simulate a compact particle, such as a meteoroid or a fragment of space debris. Different design schemes of ETD with different composition explosive charge initiation schemes with notably low speeds of the jet cut-off are explored, and a method to control the particle velocity is proposed. Numerical simulation of device modes and basic technical characteristics of experimental testing are investigated.

  6. Experimental device-independent tests of classical and quantum dimensions

    NASA Astrophysics Data System (ADS)

    Ahrens, Johan; Badziag, Piotr; Cabello, Adán; Bourennane, Mohamed

    2012-08-01

    A fundamental resource in any communication and computation task is the amount of information that can be transmitted and processed. The classical information encoded in a set of states is limited by the number of distinguishable states or classical dimension dc of the set. The sets used in quantum communication and information processing contain states that are neither identical nor distinguishable, and the quantum dimension dq of the set is the dimension of the Hilbert space spanned by these states. An important challenge is to assess the (classical or quantum) dimension of a set of states in a device-independent way, that is, without referring to the internal working of the device generating the states. Here we experimentally test dimension witnesses designed to efficiently determine the minimum dimension of sets of (three or four) photonic states from the correlations originated from measurements on them, and distinguish between classical and quantum sets of states.

  7. Direct Numerical Simulation of Liquid Nozzle Spray with Comparison to Shadowgraphy and X-Ray Computed Tomography Experimental Results

    NASA Astrophysics Data System (ADS)

    van Poppel, Bret; Owkes, Mark; Nelson, Thomas; Lee, Zachary; Sowell, Tyler; Benson, Michael; Vasquez Guzman, Pablo; Fahrig, Rebecca; Eaton, John; Kurman, Matthew; Kweon, Chol-Bum; Bravo, Luis

    2014-11-01

    In this work, we present high-fidelity Computational Fluid Dynamics (CFD) results of liquid fuel injection from a pressure-swirl atomizer and compare the simulations to experimental results obtained using both shadowgraphy and phase-averaged X-ray computed tomography (CT) scans. The CFD and experimental results focus on the dense near-nozzle region to identify the dominant mechanisms of breakup during primary atomization. Simulations are performed using the NGA code of Desjardins et al (JCP 227 (2008)) and employ the volume of fluid (VOF) method proposed by Owkes and Desjardins (JCP 270 (2013)), a second order accurate, un-split, conservative, three-dimensional VOF scheme providing second order density fluxes and capable of robust and accurate high density ratio simulations. Qualitative features and quantitative statistics are assessed and compared for the simulation and experimental results, including the onset of atomization, spray cone angle, and drop size and distribution.

  8. Micro-capillary aerosol focusing device: theoretical modeling, experimental verification, and device fabrication.

    NASA Astrophysics Data System (ADS)

    Hoey, Justin; Akhatov, Iskander; Swenson, Orven; Schulz, Doug

    2007-11-01

    A theoretical model for the focusing of aerosol particles in a linearly-varying micro-capillary with a diameter on the order of 100 microns is presented. This theoretical model is experimentally verified by visualizing an aerosol beam of silver-ink aerosol particles of approximately 1 micron in diameter emitted from a micro-capillary. Additional validation is presented in the deposited lines where linewidth is a function of aerosol beamwidth. From the theoretical model a new design for the focusing of aerosol particles is developed, physically produced, and experimentally validated. The new device will be implemented in the areas of high frequency RFID manufacturing, and the semiconductor industry.

  9. Inertial electrostatic confinement: Theoretical and experimental studies of spherical devices

    NASA Astrophysics Data System (ADS)

    Meyer, Ryan

    Inertial Electrostatic Confinement (IEC) is a means to confine ions for fusion purposes with electrostatic fields in a converging geometry. Its engineering simplicity makes it appealing when compared to magnetic confinement devices. It is hoped that such a device may one day be a net energy producer, but it has near term applications as a neutron generator. We study spherical IECs (SIECs), both theoretically and experimentally. Theoretically, we compute solutions in the free molecular limit and map out regions in control parameter space conducive to the formation of double potential wells. In addition, several other observables are mapped in the control parameter space. Such studies predict the threshold for the phenomena of "core splitting" to occur when the fractional well depth (FWD) is ˜70%-80%. With respect to double potential wells, it is shown that an optimal population of electrons exists for double well formation. In addition, double well depth is relatively insensitive to space charge spreading of ion beams. Glow discharge devices are studied experimentally with double and single Langmuir probes. The postulated micro-channeling phenomenon is verified with density measurements along a micro-channel and along the radius where micro-channels are absent. In addition, the measurements allow an evaluation of the neutrality of micro-channels and the heterogeneous structure of "Star Mode". It is shown that, despite visual evidence, micro-channeling persists well into "Jet" mode. In addition, the threshold for the "Star" mode to "Jet" mode transition is obtained experimentally. The studies have revealed new techniques for estimating tangential electric field components and studying the focusing of ion flow.

  10. Experimental device for measuring the dynamic properties of diaphragm motors

    NASA Astrophysics Data System (ADS)

    Fojtášek, Kamil; Dvořák, Lukáš; Mejzlík, Jan

    The subject of this paper is to design and description of the experimental device for the determination dynamic properties of diaphragm pneumatic motors. These motors are structurally quite different from conventional pneumatic linear cylinders. The working fluid is typically compressed air, the piston of motor is replaced by an elastic part and during the working cycle there is a contact of two elastic environments. In the manufacturers catalogs of these motors are not given any working characteristics. Description of the dynamic behavior of diaphragm motor will be used for verification of mathematical models.

  11. Experimental device for measuring the dynamic properties of diaphragm motors

    NASA Astrophysics Data System (ADS)

    Fojtášek, Kamil; Dvořák, Lukáš; Mejzlík, Jan

    2016-11-01

    The subject of this paper is to design and description of the experimental device for the determination dynamic properties of diaphragm pneumatic motors. These motors are structurally quite different from conventional pneumatic linear cylinders. The working fluid is typically compressed air, the piston of motor is replaced by an elastic part and during the working cycle there is a contact of two elastic environments. In the manufacturers catalogs of these motors are not given any working characteristics. Description of the dynamic behavior of diaphragm motor will be used for verification of mathematical models.

  12. Abatement of particulate matter emission from experimental aviary housings for laying hens by spraying rapeseed oil.

    PubMed

    Winkel, A; van Riel, J W; van Emous, R A; Aarnink, A J A; Groot Koerkamp, P W G; Ogink, N W M

    2016-12-01

    In alternative systems for laying hens, concentrations and emission rates of particulate matter (PM) give reason for concern with regard to working conditions, bird health and productivity, and health of residents living near farms. Previously, we found that spraying a film of rapeseed oil onto the litter of broilers could substantially reduce PM concentrations and emissions. The objective of this study was to establish dose-response effects of oil spraying in aviaries on concentrations and emission rates of PM with aerodynamic diameters less than 10 μm (PM10) and 2.5 μm (PM2.5), on stockmen's exposure to PM10, on egg production, exterior quality and behavior of the hens, and on the litter. An experiment was carried out with 4 treatments: 0 (control), 15, 30, and 45 mL/m(2) per d (oil treatments). Each treatment was applied in 2 rooms with different aviary systems (8 rooms in total). The experiment was repeated during a second period, both lasting 35 days. From d 11 to d 35, oil was applied daily using a spraying gun. Applying 15, 30, or 45 mL/m(2) per d significantly reduced emission rates of PM10 by 27, 62, and 82%, and emission rates of PM2.5 by 71, 83, and 94%, respectively. No significant effects of oil spraying were found on mortality, egg production, dust bathing behavior, scratching behavior, plumage soiling, DM content of the litter, or friability of the litter. A significant worsening of the plumage condition was found only for the body spot back/wings/tail (not for: throat/neck, chest/breast, or legs) in the 45 mL/m(2) per d treatment. Egg quality shifted significantly towards more second-class eggs in the oil treatments (1.9% versus 1.4%; P = 0.004). Remarkably, foot soiling decreased with increasing oil application. In conclusion, PM concentrations and emission rates in aviaries can be effectively reduced by spraying 15 to 30 mL/m(2) per d with minor side effects within a 25 d application period.

  13. Efficacy of Some Wearable Devices Compared with Spray-On Insect Repellents for the Yellow Fever Mosquito, Aedes aegypti (L.) (Diptera: Culicidae)

    PubMed Central

    Chung, Hae-Na; Gonzales, Kristina K.; Vulcan, Julia; Li, Yiyi; Ahumada, Jorge A.; Romero, Hector M.; De La Torre, Mario; Shu, Fangjun; Hansen, Immo A.

    2017-01-01

    The current Zika health crisis in the Americas has created an intense interest in mosquito control methods and products. Mosquito vectors of Zika are of the genus Aedes, mainly the yellow fever mosquito, Aedes aegypti. L. The use of repellents to alter mosquito host seeking behavior is an effective method for the prevention of mosquito-borne diseases. A large number of different spray-on repellents and wearable repellent devices are commercially available. The efficacies of many repellents are unknown. This study focuses on the efficacy of eleven different repellents in reducing the number of Ae. aegypti female mosquitoes attracted to human bait. We performed attraction-inhibition assays using a taxis cage in a wind tunnel setting. One person was placed upwind of the taxis cage and the mosquito movement towards or away from the person was recorded. The person was treated with various spray-on repellents or equipped with different mosquito repellent devices. We found that the spray-on repellents containing N,N-Diethyl-meta-toluamide and p-menthane-3,8-diol had the highest efficacy in repelling mosquitoes compared to repellents with other ingredients. From the five wearable devices that we tested, only the one that releases Metofluthrin significantly reduced the numbers of attracted mosquitoes. The citronella candle had no effect. We conclude that many of the products that we tested that were marketed as repellents do not reduce mosquito attraction to humans. PMID:28423421

  14. Using the Box-Behnken experimental design to optimise operating parameters in pulsed spray fluidised bed granulation.

    PubMed

    Liu, Huolong; Wang, Ke; Schlindwein, Walkiria; Li, Mingzhong

    2013-05-20

    In this work, the influence factors of pulsed frequency, binder spray rate and atomisation pressure of a top-spray fluidised bed granulation process were studied using the Box-Behnken experimental design method. Different mathematical models were developed to predict the mean size of granules, yield, relative width of granule distribution, Hausner ratio and final granule moisture content. The study has supported the theory that the granule size can be controlled through the liquid feed pulsing. However, care has to be taken when the pulsed frequency is chosen for controlling the granule size due to the nonlinear quadratic relation in the regression model. The design space of the ranges of operating parameters has been determined based on constraints of the mean size of granules and granule yield. High degree of prediction obtained from validation experiments has shown the reliability and effectiveness of using the Box-Behnken experimental design method to study a fluidised bed granulation process. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Inverse mirror plasma experimental device (IMPED) - a magnetized linear plasma device for wave studies

    NASA Astrophysics Data System (ADS)

    Bose, Sayak; Chattopadhyay, P. K.; Ghosh, J.; Sengupta, S.; Saxena, Y. C.; Pal, R.

    2015-04-01

    In a quasineutral plasma, electrons undergo collective oscillations, known as plasma oscillations, when perturbed locally. The oscillations propagate due to finite temperature effects. However, the wave can lose the phase coherence between constituting oscillators in an inhomogeneous plasma (phase mixing) because of the dependence of plasma oscillation frequency on plasma density. The longitudinal electric field associated with the wave may be used to accelerate electrons to high energies by exciting large amplitude wave. However when the maximum amplitude of the wave is reached that plasma can sustain, the wave breaks. The phenomena of wave breaking and phase mixing have applications in plasma heating and particle acceleration. For detailed experimental investigation of these phenomena a new device, inverse mirror plasma experimental device (IMPED), has been designed and fabricated. The detailed considerations taken before designing the device, so that different aspects of these phenomena can be studied in a controlled manner, are described. Specifications of different components of the IMPED machine and their flexibility aspects in upgrading, if necessary, are discussed. Initial results meeting the prerequisite condition of the plasma for such study, such as a quiescent, collisionless and uniform plasma, are presented. The machine produces δnnoise/n <= 1%, Luniform ~ 120 cm at argon filling pressure of ~10-4 mbar and axial magnetic field of B = 1090 G.

  16. Quality by design (QbD) approach for design and development of drug-device combination products: A case study on flunisolide nasal spray.

    PubMed

    Chudiwal, Swapnil Sharadkumar; Dehghan, Mohamed Hassan G

    2016-09-10

    The objective of the present study was to design and develop drug-device combination product in particular flunisolide nasal spray using quality by design (QbD) approach. Quality target product profile (QTPP) of flunisolide nasal spray was defined and critical quality attributes (CQAs) i.e. viscosity (cp) (Y1) and D50 DSD (µm) (Y2) were identified. Potential risk factors were identified using a fish bone diagram and failure mode effect analysis (FMEA) tools. Plackett Burman and Box Behnken design were used for screening the significant factors and optimizing the variables range respectively. It was observed that viscosity (cp) (Y1) was significantly impacted by formulation variables X1: Propylene Glycol (PG) (%) and X2: Polyethylene Glycol (PEG) 3350 (%), while D50 droplet size distribution (DSD) (µm) (Y2) was significantly impacted by formulation variables X1: PG (%), X2: PEG 3350 (%) and device variable X8: delivery volume (µl). A design space plot within which the CQAs remained unchanged was established at laboratory scale. In conclusion, this study demonstrated how QbD based development approach can be applied to the development of drug device combination products with enhanced understanding of impact of formulation, process and device variables on CQAs of drug device combination products.

  17. Characterization of sprays

    NASA Technical Reports Server (NTRS)

    Chigier, N.; Mao, C.-P.

    1984-01-01

    It is pointed out that most practical power generation and propulsion systems involve the burning of different types of fuel sprays, taking into account aircraft propulsion, industrial furnaces, boilers, gas turbines, and diesel engines. There has been a lack of data which can serve as a basis for spray model development and validation. A major aim of the present investigation is to fill this gap. Experimental apparatus and techniques for studying the characteristics of fuel sprays are discussed, taking into account two-dimensional still photography, cinematography, holography, a laser diffraction particle sizer, and a laser anemometer. The considered instruments were used in a number of experiments, taking into account three different types of fuel spray. Attention is given to liquid fuel sprays, high pressure pulsed diesel sprays, and coal-water slurry sprays.

  18. Numerical and Experimental Investigation of Cold Spray Gas Dynamic Effects for Polymer Coating

    NASA Astrophysics Data System (ADS)

    Alhulaifi, Abdulaziz S.; Buck, Gregory A.; Arbegast, William J.

    2012-09-01

    Low melting temperature materials such as polymers are known to be difficult to deposit using traditional cold spray techniques. Computational fluid dynamics (CFD) models were created for various nozzle geometries and flow conditions. A schlieren optical system was used to visualize the density gradients and flow characteristics in the free jet impingement region. Based on the CFD models, it was determined that a diffuser placed into the carrier gas flow near the nozzle exit not only leads to lower particle impact velocity required for polymer deposition, but also provides for appropriate application of compression heating of the particles to produce the conditions necessary at impact for successful coating adhesion of these materials. Experiments subsequently confirmed the successful deposition of polyethylene powder onto a 7075-T6 aluminum substrate. Using air as the carrier gas, polyethylene particles of 53-75 μm diameter and 0.94 g/cm3 density, were cold spray deposited onto the aluminum substrate, with a critical impact velocity of 191 m/s. No apparent melting of the polymer particles was observed. Refinements to these concepts are currently under investigation and a patent disclosure for the idea is pending.

  19. Modelling and experimental investigations of thin films of Mg phosphorus-doped tungsten bronzes obtained by ultrasonic spray pyrolysis.

    PubMed

    Jokanović, V; Nedić, Z; Colović, B

    2008-12-01

    In this study, the synthesis of thin films of Mg phosphorus doped tungsten bronzes (MgPTB; MgHPW(12)O(40).29H(2)O) by the self-assembly of nano-structured particles of MgPTB obtained using the ultrasonic spray pyrolysis method was investigated. As the precursor, MgPTB, prepared by the ionic exchange method, was used. Nano-structured particles of MgPTB were obtained using the ultrasonic spray pyrolysis method. The nano-structure of the particles used as the building blocks in the MgPTB thin film were investigated experimentally and theoretically, applying the model given in this article. The obtained data for the mean particle size and their size distribution show a high degree of agreement. These previously tailored particles used for the preparation of thin films during the next synthesis step, by their self-assembly over slow deposition on a silica glass substrate, show how it is possible to create thin MgPTB films under advance projected conditions of the applied physical fields with a fully determined nanostructure of their building block particles, with a relatively small roughness and unique physical properties.

  20. High-Velocity Oxygen Fuel Thermal Spray of Fe-Based Amorphous Alloy: a Numerical and Experimental Study

    NASA Astrophysics Data System (ADS)

    Ajdelsztajn, L.; Dannenberg, J.; Lopez, J.; Yang, N.; Farmer, J.; Lavernia, E. J.

    2009-09-01

    The fabrication of dense coatings with appropriate properties using a high velocity oxygen fuel (HVOF) spray process requires an in-depth understanding of the complete gas flow field and particle behavior during the process. A computational fluid dynamics (CFD) model is implemented to investigate the gas flow behavior that occurs during the HVOF process and a simplified one-dimensional decoupled model of the in-flight thermal behavior of the amorphous Fe-based powder particles was developed and applied for three different spray conditions. The numerical results were used to rationalize the different coating microstructures described in the experimental results. Low porosity and amorphous coatings were produced using two different particle size distributions (16 to 25 μm and 25 to 53 μm). The amorphous characteristics of the powder were retained in the coating due to melting and rapid solidification in the case of very fine powder or ligaments (<16 μm) and to the fact that the crystallization temperature was not reached in the case of the large particles (16 to 53 μm).

  1. Computational study and experimental comparison of the in-flight particle behavior for an external injection plasma spray process

    NASA Astrophysics Data System (ADS)

    Remesh, K.; Yu, S. C. M.; Ng, H. W.; Berndt, C. C.

    2003-12-01

    A three-dimensional computational fluid dynamic (CFD) analysis using Fluent V5.4 was conducted on the in-flight particle behavior during the plasma spraying process with external injection. The spray process was modeled as a steady jet issuing from the torch nozzle via the heating of the are gas by an electric are within the nozzle. The stochastic discrete model was used for the particle distribution. The particle temperature, velocity, and size inside the plasma plume at a specified standoff distance have been investigated. The results show that carrier gas flow rate variation from 2 standard liters per minute (slm) to 4.0 slm can increase the centerline particle mean temperature and mean velocity by 10% and 16%, respectively, at the specified standoff distance. A further increase of the carrier gas flow rate to 6 slm did not change the particle temperature, but the particle velocity was decreased by 20%. It was also found that an increase in the total arc gas flow rate from 52 slm to 61 slm, with all other process parameters unchanged, resulted in a 17% higher particle velocity, but 6% lower particle temperature. Some of these computational findings were experimentally confirmed by Kucuk et al. For a given process parameter setting, the kinetic and thermal energy extracted by the particles reached a maximum for carrier gas flow rate of about 3.5 4.0 slm.

  2. Experimental Flow Characterization of a Flow Diverting Device

    NASA Astrophysics Data System (ADS)

    Sparrow, Eph; Chow, Ricky; Campbell, Gary; Divani, Afshin; Sheng, Jian

    2012-11-01

    Flow diverters, such as the Pipeline Embolization Device, are a new class of endovascular devices for the treatment of intracranial aneurysms. While clinical studies have demonstrated safety and efficacy, their impact on intra-aneurysmal flow is not confirmed experimentally. As such, optimization of the flow diversion behavior is not currently possible. A quasi-3D PIV technique was developed and applied in various glass models at Re = 275 and 550 to determine the changes to flow characteristics due to the deployment of a flow diverter across the aneurysm neck. Outcomes such as mean velocity, wall shear stress, and others metrics will be presented. Glass models with varying radii of curvature and aneurysm locations will be examined. Experiments were performed in a fully index-matched flow facility using ~10 μm diameter polystyrene particles doped with Rhodium 6G dye. The particles were illuminated with a 532nm laser sheet and observed with a CCD camera and a 592nm +/-43 nm bandpass filter. A quasi 3D flow field was reconstructed from multiple orthogonal planes (spaced 0.4mm apart) encompassing the entire glass model. Wall stresses were evaluated from the near-wall flow viscous stresses.

  3. Numerical and experimental investigations of splat geometric characteristics during oblique impact of plasma spraying

    NASA Astrophysics Data System (ADS)

    Kang, Chang-Wei; Tan, Jiak Kwang; Pan, Lunsheng; Low, Cheng Yee; Jaffar, Ahmed

    2011-10-01

    Splats are obtained on the substrates inclined at different angles (0°, 20°, 40° and 60°) by plasma spraying process and characterized by SEM and WYKO ® optical surface profiler. Numerical model is developed using CFD software FLOW-3D ® to simulate the process of droplet impact, spreading and solidification onto the substrates. Splat characteristics such as spread factor, aspect ratio and fractional factor are defined and compared between simulation and experiment. Fair agreements are obtained. In addition, the impacting behavior including spreading and solidification are analyzed in details from the simulation results. The rates of reduction in droplet kinetic energy during impact, spreading and solidification are also compared between different inclination angles.

  4. Experimental investigation on erosive wear behaviour of plasma spray coated stainless steel

    NASA Astrophysics Data System (ADS)

    Girisha, K. G.; Sreenivas Rao, K. V.; Anil, K. C.; Sanman, S.

    2017-04-01

    Slurry erosion is an implicit problem in many engineering industrial components such as ore carrying pipelines, slurry pumps and extruders. Even the water turbine blades are subjected to erosive wear when the water contains considerable amount of silt. In the present study, Al2O3-40%TiO2 powder particles of average particle size of 50 micrometer were deposited on EN56B martenistic stainless steel by atmospheric plasma spray technique. Ni/Cr was pre coated to work as bond coat for good adhesion between coating and the substrate material. A coating thickness of 200 micrometer was achieved. Coated and un-coated substrates were subjected to slurry erosion test as per ASTM G-119 standard. Slurry erosion test rig was used to evaluate the erosion properties at room temperature condition by varying the spindle speed. Scanning electron microphotographs were taken before and after the slurry erosion test. Microstructures reveal uniform distribution of coating materials. Eroded surface shows lip, groove, and crater formation and dense coating resulting in less porosity. Micro hardness test was evaluated and reported. EDX analysis confirms the presence of Al, Ti and O2 particles. It was observed that, Al2O3-40%TiO2 coated substrates exhibit superior erosion resistance as compared to un-coated substrates due to higher hardness and less coating porosity.

  5. Efficacy of Some Wearable Devices Compared with Spray-On Insect Repellents for the Yellow Fever Mosquito, Aedes aegypti (L.) (Diptera: Culicidae).

    PubMed

    Rodriguez, Stacy D; Chung, Hae-Na; Gonzales, Kristina K; Vulcan, Julia; Li, Yiyi; Ahumada, Jorge A; Romero, Hector M; De La Torre, Mario; Shu, Fangjun; Hansen, Immo A

    2017-01-01

    The current Zika health crisis in the Americas has created an intense interest in mosquito control methods and products. Mosquito vectors of Zika are of the genus Aedes, mainly the yellow fever mosquito, Aedes aegypti. L. The use of repellents to alter mosquito host seeking behavior is an effective method for the prevention of mosquito-borne diseases. A large number of different spray-on repellents and wearable repellent devices are commercially available. The efficacies of many repellents are unknown. This study focuses on the efficacy of eleven different repellents in reducing the number of Ae. aegypti female mosquitoes attracted to human bait. We performed attraction-inhibition assays using a taxis cage in a wind tunnel setting. One person was placed upwind of the taxis cage and the mosquito movement towards or away from the person was recorded. The person was treated with various spray-on repellents or equipped with different mosquito repellent devices. We found that the spray-on repellents containing N,N-Diethyl-meta-toluamide and p-menthane-3,8-diol had the highest efficacy in repelling mosquitoes compared to repellents with other ingredients. From the five wearable devices that we tested, only the one that releases Metofluthrin significantly reduced the numbers of attracted mosquitoes. The citronella candle had no effect. We conclude that many of the products that we tested that were marketed as repellents do not reduce mosquito attraction to humans. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  6. Specifics of phytomass combustion in small experimental device

    NASA Astrophysics Data System (ADS)

    Lenhard, Richard; Mičieta, Jozef; Jandačka, Jozef; Gavlas, Stanislav

    2015-05-01

    A wood pellet combustion carries out with high efficiency and comfort in modern pellet boilers. These facts help to increase the amount of installed pellet boilers in households. The combustion process quality depends besides the combustion conditions also on the fuel quality. The wood pellets, which don`t contain the bark and branches represent the highest quality. Because of growing pellet demand, an herbal biomass (phytomass), which is usually an agricultural by-product becomes economically attractive for pellet production. Although the phytomass has the net calorific value relatively slightly lower than the wood biomass, it is often significantly worse in view of the combustion process and an emission production. The combustion of phytomass pellets causes various difficulties in small heat sources, mainly due to a sintering of fuel residues. We want to avoid the ash sintering by a lowering of temperature in the combustion chamber below the ash sintering temperature of phytomass via the modification of a burner design. For research of the phytomass combustion process in the small boilers is constructed the experimental combustion device. There will investigate the impact of cooling intensity of the combustion chamber on the combustion process and emissions. Arising specific requirements from the measurement will be the basis for the design of the pellet burner and for the setting of operating parameters to the trouble-free phytomass combustion was guaranteed.

  7. Experimental Study on Electrical Breakdown for Devices with Micrometer Gaps

    NASA Astrophysics Data System (ADS)

    Meng, Guodong; Cheng, Yonghong; Dong, Chengye; Wu, Kai

    2014-12-01

    The understanding of electrical breakdown in atmospheric air across micrometer gaps is critically important for the insulation design of micro & nano electronic devices. In this paper, planar aluminum electrodes with gaps ranging from 2 μm to 40 μm were fabricated by microelectromechanical system technology. The influence factors including gap width and surface dielectric states were experimentally investigated using the home-built test and measurement system. Results showed that for SiO2 layers the current sustained at 2-3 nA during most of the pre-breakdown period, and then rose rapidly to 10-30 nA just before breakdown due to field electron emission, followed by the breakdown. The breakdown voltage curves demonstrated three stages: (1) a constantly decreasing region (the gap width d < 5 μm), where the field emission effect played an important role just near breakdown, supplying enough initial electrons for the breakdown process; (2) a plateau region with a near constant breakdown potential (5 μm < d < 10 μm) (3) a region for large gaps that adhered to Paschen's curve (d > 10 μm). And the surface dielectric states including the surface resistivity and secondary electron yield were verified to be related to the propagation of discharge due to the interaction between initial electrons and dielectrics.

  8. Recent Experimental Results in the VX-10 Device

    NASA Astrophysics Data System (ADS)

    Squire, J. P.; Díaz, F. R. Chang; Jacobson, V. T.; McCaskill, G. E.; McCoy, J. E.; Petro, A. J.; Baity, F. W.; Bengtson, R. D.; Bering, E. A.; Garret, J. A.; Glover, T. W.

    2000-10-01

    In the VASIMR engine, neutral gas is ionized using a helicon type source and the ions are subsequently accelerated via ICRF power injection. The experimental device in the ASPL is targeting a total RF power level of 10 kW and is called VX-10. RF power is available with 3 kW at 25 MHz for the helicon source and 100 kW at 3 MHz for ICRF. Experiments with light gasses (hydrogen, deuterium, and helium) are performed. The VX-10 3-magnet system is capable of a maximum B field of 2 T and has flexible axial profile shaping capability. Diagnostics in the plasma exhaust include an RF compensated Langmuir probe, a Mach probe, Retarding Potential Analyzer (RPA), newly installed density interferometer and an ion gauge neutral pressure measurement. Parametric (e.g. magnetic field, gas flow, and RF power) studies are presented. Data indicate ion heating to more than 1 eV and acceleration by the magnetic exhaust with the helicon alone. ICRF experiments are beginning and initial data are presented.

  9. Experimental evaluation of cooling efficiency of the high performance cooling device

    NASA Astrophysics Data System (ADS)

    Nemec, Patrik; Malcho, Milan

    2016-06-01

    This work deal with experimental evaluation of cooling efficiency of cooling device capable transfer high heat fluxes from electric elements to the surrounding. The work contain description of cooling device, working principle of cooling device, construction of cooling device. Experimental part describe the measuring method of device cooling efficiency evaluation. The work results are presented in graphic visualization of temperature dependence of the contact area surface between cooling device evaporator and electronic components on the loaded heat of electronic components in range from 250 to 740 W and temperature dependence of the loop thermosiphon condenser surface on the loaded heat of electronic components in range from 250 to 740 W.

  10. Experimental evaluation of cooling efficiency of the high performance cooling device

    SciTech Connect

    Nemec, Patrik Malcho, Milan

    2016-06-30

    This work deal with experimental evaluation of cooling efficiency of cooling device capable transfer high heat fluxes from electric elements to the surrounding. The work contain description of cooling device, working principle of cooling device, construction of cooling device. Experimental part describe the measuring method of device cooling efficiency evaluation. The work results are presented in graphic visualization of temperature dependence of the contact area surface between cooling device evaporator and electronic components on the loaded heat of electronic components in range from 250 to 740 W and temperature dependence of the loop thermosiphon condenser surface on the loaded heat of electronic components in range from 250 to 740 W.

  11. Feeding Experimentation Device (FED): A flexible open-source device for measuring feeding behavior.

    PubMed

    Nguyen, Katrina P; O'Neal, Timothy J; Bolonduro, Olurotimi A; White, Elecia; Kravitz, Alexxai V

    2016-07-15

    Measuring food intake in rodents is a conceptually simple yet labor-intensive and temporally-imprecise task. Most commonly, food is weighed manually, with an interval of hours or days between measurements. Commercial feeding monitors are excellent, but are costly and require specialized caging and equipment. We have developed the Feeding Experimentation Device (FED): a low-cost, open-source, home cage-compatible feeding system. FED utilizes an Arduino microcontroller and open-source software and hardware. FED dispenses a single food pellet into a food well where it is monitored by an infrared beam. When the mouse removes the pellet, FED logs the timestamp to a secure digital (SD) card and dispenses a new pellet into the well. Post-hoc analyses of pellet retrieval timestamps reveal high-resolution details about feeding behavior. FED is capable of accurately measuring food intake, identifying discrete trends during light and dark-cycle feeding. Additionally, we show the utility of FED for measuring increases in feeding resulting from optogenetic stimulation of agouti-related peptide neurons in the arcuate nucleus of the hypothalamus. With a cost of ∼$350 per device, FED is >10× cheaper than commercially available feeding systems. FED is also self-contained, battery powered, and designed to be placed in standard colony rack cages, allowing for monitoring of true home cage feeding behavior. Moreover, FED is highly adaptable and can be synchronized with emerging techniques in neuroscience, such as optogenetics, as we demonstrate here. FED allows for accurate, precise monitoring of feeding behavior in a home cage setting. Published by Elsevier B.V.

  12. Measured effects of retrofits -- a refrigerant oil additive and a condenser spray device -- on the cooling performance of a heat pump

    SciTech Connect

    Levins, W.P.; Sand, J.R.; Baxter, V.D.; Linkous, R.L.

    1996-05-01

    A 15-year old, 3-ton single package air-to-air heat pump was tested in laboratory environmental chambers simulating indoor and outdoor conditions. After documenting initial performance, the unit was retrofitted with a prototype condenser water-spray device and retested. Results at standard ARI cooling rating conditions (95 F outdoor dry bulb and 80/67 F indoor dry bulb/wet bulb temperatures) showed the capacity increased by about 7%, and the electric power demand dropped by about 8%, resulting in a steady-state EER increase of 17%. Suction and discharge pressures were reduced by 7 and 37 psi, respectively. A refrigerant oil additive formulated to enhance refrigerant-side heat transfer was added at a dose of one ounce per ton of rated capacity, and the unit was tested for several days at the same 95 F outdoor conditions and showed essentially no increase in capacity, and a slight 3% increase in steady-state EER. Adding more additive lowered the EER slightly. Suction and discharge pressures were essentially unchanged. The short-term testing showed that the condenser-spray device was effective in increasing the cooling capacity and lowering the electrical demand on an old and relatively inefficient heat pump, but the refrigerant additive had little effect on the cooling performance of the unit. Sprayer issues to be resolved include the effect of a sprayer on a new, high-efficiency air conditioner/heat pump, reliable long-term operation, and economics.

  13. Preparation and characterization of spray deposited n-type WO{sub 3} thin films for electrochromic devices

    SciTech Connect

    Sivakumar, R.; Moses Ezhil Raj, A.; Subramanian, B.; Jayachandran, M.; Trivedi, D.C.; Sanjeeviraja, C

    2004-08-03

    The n-type tungsten oxide (WO{sub 3}) polycrystalline thin films have been prepared at an optimized substrate temperature of 250 deg. C by spray pyrolysis technique. Precursor solution of ammonium tungstate ((NH{sub 4}){sub 2}WO{sub 4}) was sprayed onto the well cleaned, pre-heated fluorine doped tin oxide coated (FTO) and glass substrates with a spray rate of 15 ml/min. The structural, surface morphological and optical properties of the as-deposited WO{sub 3} thin films were studied. Mott-Schottky (M-S) studies of WO{sub 3}/FTO electrodes were conducted in Na{sub 2}SO{sub 4} solution to identify their nature and extract semiconductor parameters. The electrochromic properties of the as-deposited and lithiated WO{sub 3}/FTO thin films were analyzed by employing them as working electrodes in three electrode electrochemical cell using an electrolyte containing LiClO{sub 4} in propylene carbonate (PC) solution.

  14. Experimental and Theoretical Investigation of Innovative Broadband Microwave Devices

    DTIC Science & Technology

    1991-05-01

    over conventional devices such as the helix TWT . The TSA is also a broad band device; however, the bandwidth of the configuration chosen ultimately...by the TSA over the helix TWT in regard to bandwidth as well. Although the high gain in the TSA confers the advantage of being relatively less...prebuncher for the output helix stage. Thus. the device is essentially a helix TWT im (k) =45C with enhanced bunching due to the two-stream interac-Re() 2+C

  15. Application of experimental and numerical simulation techniques to microscale devices

    NASA Astrophysics Data System (ADS)

    Somashekar, Vishwanath

    Two of the areas that have become relevant recently are the areas of mixing in micro-scale devices, and manufacturing of functional nanoparticles. MicroPIV experiments were performed on two different mixers, one a wide microchannel with the surface grooves, in the laminar regime, and the other, a confined impinging jets reactor, in the laminar and turbulent regimes. In the wide microchannel with surface grooves, microPIV data were collected at the interface and the midplane at the Reynolds numbers of 0.08, 0.8, and 8. The experiments were performed on three internal angles of the chevrons, namely 135°, 90°, and 45°. The normalized transverse velocity generated in the midplane due to the presence of the grooves, is the strongest for the internal angle of 135°, and in that, the normalized transverse velocity is maximum at the Reynolds numbers of 0.08 and 0.8. MicroPIV experiments were performed in a confined impinging jets reactors at Reynolds numbers of 200, 1000, and 1500. The data was collected in the midplane, and turbulent statistics were further computed. The high velocity jets impinge along the centerline of the reactor. Upon impinging, part of the fluid turns towards the top wall and the majority of it turn towards the outlet. This high velocity impingement causes and unstable zone called the impingement zone, which moves about the centerline line, causing the jets to flap back and forth. Spatial correlations were computed to get an estimate of the size of the coherent structures. Large eddy simulation was performed on the CIJR for the Reynolds numbers of 1000 and 1500, using OpenFOAM. The Reynolds number is based on the inlet jet hydraulic diameter. Excellent agreement was found with the experimental and simulation data. Turbulent reactive mixing in a rectangular microscale confined impinging-jets reactor (CIJR) was investigated using the pH indicator phenolphthalein in this study for three different jet Reynolds numbers of 25, 1000 and 1500. Laminar

  16. Experimental Measurement-Device-Independent Quantum Key Distribution

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Chen, Teng-Yun; Wang, Liu-Jun; Liang, Hao; Shentu, Guo-Liang; Wang, Jian; Cui, Ke; Yin, Hua-Lei; Liu, Nai-Le; Li, Li; Ma, Xiongfeng; Pelc, Jason S.; Fejer, M. M.; Peng, Cheng-Zhi; Zhang, Qiang; Pan, Jian-Wei

    2013-09-01

    Quantum key distribution is proven to offer unconditional security in communication between two remote users with ideal source and detection. Unfortunately, ideal devices never exist in practice and device imperfections have become the targets of various attacks. By developing up-conversion single-photon detectors with high efficiency and low noise, we faithfully demonstrate the measurement-device-independent quantum-key-distribution protocol, which is immune to all hacking strategies on detection. Meanwhile, we employ the decoy-state method to defend attacks on a nonideal source. By assuming a trusted source scenario, our practical system, which generates more than a 25 kbit secure key over a 50 km fiber link, serves as a stepping stone in the quest for unconditionally secure communications with realistic devices.

  17. Survey and Experimental Testing of Nongravimetric Mass Measurement Devices

    NASA Technical Reports Server (NTRS)

    Oakey, W. E.; Lorenz, R.

    1977-01-01

    Documentation presented describes the design, testing, and evaluation of an accelerated gravimetric balance, a low mass air bearing oscillator of the spring-mass type, and a centrifugal device for liquid mass measurement. A direct mass readout method was developed to replace the oscillation period readout method which required manual calculations to determine mass. A protoype 25 gram capacity micro mass measurement device was developed and tested.

  18. Experimental measurement, calculation and thermal visualization condenser temperature of cooling device with a heat pipe technology

    NASA Astrophysics Data System (ADS)

    Nemec, Patrik; Malcho, Milan; Kaduchová, Katarína

    This work deal with evaluation of condenser temperature by experimental measurement, calculation and thermal visualization of cooling device working with a heat pipe technology. The referred device in the article is cooling device capable transfer high heat fluxes from electric elements to the surrounding. One from many things influenced the heat flux amount transferred from electronic elements through the cooling device to the surrounding is condenser construction, its capacity and option of heat removal. The work contain description, working principle and construction of cooling device. Experimental part describe the measuring method and mathematical calculation to condenser temperature evaluation of cooling device depending on the loaded heat of electronic components in range from 250 to 750 W. The mathematical calculation is based on physical phenomena of boiling, condensation and natural convection heat transfer. The results of experimental measurement and mathematical calculation are verified by thermal imagining of device condenser by IR camera.

  19. Spray drying formulation of albendazole microspheres by experimental design. In vitro-in vivo studies.

    PubMed

    García, Agustina; Leonardi, Darío; Piccirilli, Gisela N; Mamprin, María E; Olivieri, Alejandro C; Lamas, María C

    2015-02-01

    Both an experimental design and optimization techniques were carried out for the development of chitosan-pectin-carboxymethylcellulose microspheres to improve the oral absorption of albendazole as a model drug. The effect of three different factors (chitosan, pectin and carboxy methyl cellulose concentrations) was studied on five responses: yield, morphology, dissolution rate at 30 and 60 min, and encapsulation efficiency of the microspheres. During the screening phase, the factors were evaluated in order to identify those which exert a significant effect. Simultaneous multiple response optimizations were then used to find out experimental conditions where the system shows the most adequate results. The optimal conditions were found to be: chitosan concentration, 1.00% w/v, pectin concentration 0.10% w/v and carboxymethylcellulose concentration 0.20% w/v. The bioavailability of the loaded drug in the optimized microspheres was evaluated in Wistar rats which showed an area under curve (AUC) almost 10 times higher than the pure drug.

  20. Inhalable Spray-Freeze-Dried Powder with L-Leucine that Delivers Particles Independent of Inspiratory Flow Pattern and Inhalation Device.

    PubMed

    Otake, Hiroko; Okuda, Tomoyuki; Hira, Daiki; Kojima, Haruyoshi; Shimada, Yasuhiro; Okamoto, Hirozazu

    2016-04-01

    The purpose of this study was to develop inhalable particles that can reach deep into the lungs efficiently independent of inhalation patterns of patients and inhalation devices. We prepared porous particles including L-leucine (Leu), a dispersive agent, by a spray-freeze-drying (SFD) method and examined the influence of inspiratory flow patterns and inhalation devices with various inhalation resistances. Four types of SFD powder with different Leu contents (0-10%) were prepared. Scanning electron microscopy and laser diffraction were used to measure the morphology and size distribution of the powders. In-vitro inhalation characteristics were determined using a twin-stage liquid impinger equipped with an inspiratory flow pattern simulator. The effects of Leu on the adhesion force and electrostatic property of the particles were evaluated. The inhalation performance of the powders was improved by the addition of Leu. The powders with Leu showed a high inhalation performance regardless of inspiratory flow patterns and devices. The addition of Leu decreased the adhesion force and increased the surface potential of the powders. The SFD particles with Leu showed high inhalation performance regardless of the inhalation patterns and devices, which was attributed to the decreased adhesion force between particles and increased dispersibility.

  1. Insights into spray development from metered-dose inhalers through quantitative X-ray radiography

    SciTech Connect

    Mason-Smith, Nicholas; Duke, Daniel J.; Kastengren, Alan L.; Stewart, Peter J; Traini, Daniela; Young, Paul M; Chen, Yang; Lewis, David; Soria, Julio; Edgington-Mitchell, Daniel M; Honnery, Damon R

    2016-05-01

    Typical methods to study pMDI sprays employ particle sizing or visible light diagnostics, which suffer in regions of high spray density. X-ray techniques can be applied to pharmaceutical sprays to obtain information unattainable by conventional particle sizing and light-based techniques. We present a technique for obtaining quantitative measurements of spray density in pMDI sprays. A monochromatic focused X-ray beam was used to perform quantitative radiography measurements in the near-nozzle region and plume of HFA-propelled sprays. Measurements were obtained with a temporal resolution of 0.184 ms and spatial resolution of 5 mu m. Steady flow conditions were reached after around 30 ms for the formulations examined with the spray device used. Spray evolution was affected by the inclusion of ethanol in the formulation and unaffected by the inclusion of 0.1% drug by weight. Estimation of the nozzle exit density showed that vapour is likely to dominate the flow leaving the inhaler nozzle during steady flow. Quantitative measurements in pMDI sprays allow the determination of nozzle exit conditions that are difficult to obtain experimentally by other means. Measurements of these nozzle exit conditions can improve understanding of the atomization mechanisms responsible for pMDI spray droplet and particle formation.

  2. Experimental and simulated control of lift using trailing edge devices

    NASA Astrophysics Data System (ADS)

    Cooperman, A.; Blaylock, M.; van Dam, C. P.

    2014-12-01

    Two active aerodynamic load control (AALC) devices coupled with a control algorithm are shown to decrease the change in lift force experienced by an airfoil during a change in freestream velocity. Microtabs are small (1% chord) surfaces deployed perpendicular to an airfoil, while microjets are pneumatic jets with flow perpendicular to the surface of the airfoil near the trailing edge. Both devices are capable of producing a rapid change in an airfoil's lift coefficient. A control algorithm for microtabs has been tested in a wind tunnel using a modified S819 airfoil, and a microjet control algorithm has been simulated for a NACA 0012 airfoil using OVERFLOW. In both cases, the AALC devices have shown the ability to mitigate the changes in lift during a gust.

  3. Macroscopic and microscopic characteristics of a fuel spray impinged on the wall

    NASA Astrophysics Data System (ADS)

    Park, Sung Wook; Lee, Chang Sik

    2004-11-01

    An experimental study was performed to investigate the macroscopic behavior and atomization characteristics of a high-speed diesel spray impinged on the wall at various injection and impinging conditions. The development processes of sprays impinged on the wall were visualized using the spray visualization system composed of a Nd:YAG laser and an intensified charge-coupled device (ICCD) camera. The atomization characteristics of the impinged spray on the wall were also explored in terms of mean droplet diameter and velocity distributions by using a phase Doppler particle analyzer (PDPA) system. The results provide the effects of injection parameters, wall conditions, and the other various experimental conditions on the macroscopic behavior and atomization characteristics of the impinged sprays on the wall.

  4. Rectification magnetoresistance device: Experimental realization and theoretical simulation

    NASA Astrophysics Data System (ADS)

    Zhang, Kun; Huang, Qikun; Yan, Yi; Wang, Xiaolin; Wang, Jing; Kang, Shishou; Tian, Yufeng

    2016-11-01

    A unique technique has been proposed to realize rectification magnetoresistance (RMR) by combining a commercial diode and a magnetoresistance component in parallel. The observed RMR could be greatly tuned in a wide range by applying direct current and alternating current simultaneously to the device. Moreover, a quantitative theoretical model has been established, which well explained both the observed RMR and the electrical manipulation behavior. The highly tunable RMR and the correlated magnetoelectric functionalities provide an alternative route for developing multi-functional spintronics devices.

  5. Spray irrigation effects on surface-layer stability in an experimental citrus orchard during winter freezes

    SciTech Connect

    Cooper, H.J.; Smith, E.A.; Martsolf, J.D.

    1997-02-01

    Observations taken by two surface radiation and energy budget stations deployed in the University of Florida/Institute for Food and Agricultural Service experimental citrus orchard in Ginesville, Florida, have been analyzed to identify the effects of sprayer irrigation on thermal stability and circulation processes within the orchard during three 1992 winter freeze episodes. Lapse rates of temperature observed from a micrometeorological tower near the center of the orchard were also recorded during periods of irrigation for incorporation into the analysis. Comparisons of the near-surface temperature lapse rates observed with the two energy budget stations show consistency between the two sites and with the tower-based lapse rates taken over a vertical layer from 1.5 to 15 m above ground level. A theoretical framework was developed that demonstrates that turbulent-scale processes originating within the canopy, driven by latent heat release associated with condensation and freezing processes from water vapor and liquid water released from sprayer nozzles, can destabilize lapse rates and promote warm air mixing above the orchard canopy. The orchard data were then analyzed in the context of the theory for evidence of local overturning and displacement of surface layer air, with warmer air from aloft driven by locally buoyant plumes generated by water vapor injected into the orchard during the irrigation periods. 14 refs., 6 figs.

  6. Method and device for dynamic modelling of rubbery materials applied to human soft tissues. Part II: device and experimental results

    NASA Astrophysics Data System (ADS)

    Alaci, S.; Ciornei, M. C.; Ciornei, F. C.; Filote, C.; Romanu, I. C.

    2016-11-01

    The paper presents the experimental results obtained on an experimental device where a horizontal rubber wire is stretched by a transversal oscillating force - that is a body with an acceleration sensor attached, placed at the middle of it that oscillates freely. A nonlinear model was proposed for the experimental test rig, the differential equation of motion was offered and a series of curves were traced and compared to the experimental ones. One can conclude that the theoretical model certifies very well the behaviour of the real model. An open problem remains the manner of adopting the parameters characteristic to the dissipative element of the system.

  7. Proof-of-Concept Static Thermomagnetic Generator Experimental Device

    NASA Astrophysics Data System (ADS)

    Christiaanse, Theo; Brück, Ekkes

    2014-03-01

    A thermomagnetic power conversion device is constructed using water flows with very low caloric energy. The device has two active regenerators built from (Mn,Fe)2(P,As) materials suspended in a magnetic circuit as proposed by Brillouin and Iskenderian. The final magnetic circuit design was further optimized with finite-element simulations. The permanent magnet acting as field source was 1.4 kg of NdFeB alloy. The active part of the generator consists of 48 disks of (Mn,Fe)2(P,As) material with four different Curie temperatures of 300 K, 304 K, 307 K, and 310 K (27 °C, 31 °C, 34 °C, and 37 °C) measured in 1 T. Into each plate, microchannels are laser cut. By stacking these plates in series, two regenerators with a gradient temperature span are built. Both generators have an exact weight of 26.9 g. The material was cycled at different speeds to find the maximum power output at the optimum frequency. Critical to a better design is a more tapered design and different materials. The tapered design ensures a greater external field and a larger external field change across the material. The materials for devices that use water as heat-transfer fluid in combination with this type of regenerator design should have a lower latent heat while maintaining their magnetic properties. This will increase the cycling speed and improve the power output of this type of device.

  8. Thermal Arc Spray Overview

    NASA Astrophysics Data System (ADS)

    Hafiz Abd Malek, Muhamad; Hayati Saad, Nor; Kiyai Abas, Sunhaji; Mohd Shah, Noriyati

    2013-06-01

    Usage of protective coating for corrosion protection was on highly demand during the past decade; and thermal spray coating played a major part during that time. In recent years, the thermal arc spray coating becomes a popular coating. Many big players in oil and gas such as PETRONAS, EXXON MOBIL and SHELL in Malaysia tend to use the coating on steel structure as a corrosion protection. Further developments in coating processes, the devices, and raw materials have led to expansion of functional coatings and applications scope from conventional coating to specialized industries. It is widely used because of its ability to withstand high process temperature, offer advantages in efficiency, lower cost and acts as a corrosion protection. Previous research also indicated that the thermal arc spray offers better coating properties compared to other methods of spray. This paper reviews some critical area of thermal spray coating by discussing the process/parameter of thermal arc spray technology and quality control of coating. Coating performance against corrosion, wear and special characteristic of coating are also described. The field application of arc spray technology are demonstrated and reviewed.

  9. Experimental study of blast mitigating devices based on combined construction

    NASA Astrophysics Data System (ADS)

    Takayama, K.; Silnikov, M. V.; Chernyshov, M. V.

    2016-09-01

    A robust blast inhibiting bin is the most often used device for damage blast effects suppression. In particular, a top open cylindrical bin significantly reduces a fragmentation effect resulted from a detonation of an explosive device placed inside the bin. However, reduction of blast wave overpressure and impulse by such cylindrical bins is not sufficient [1]. A reasonable alternative to endless increase of height and thickness of robust blast inhibiting bins is a development of destructible inhibitors having no solid elements in their structure and, therefore, excluding secondary fragmentation. So, the family of "Fountain" inhibitors [2,3] localizes and suppresses damaging blast effects due to multiphase working system. The present study is analyzing data obtained in testing of prototypes of new combined inhibitors. Their structure combines robust elements (bottoms, side surfaces) with elements responsible for blast loads reduction due to multi-phase working system (top and low transverse embeddings) and fairings impeding wave propagation in undesirable directions.

  10. A portable device for experimental treatment of neurogenic detrusor overactivity.

    PubMed

    Fjorback, M V; Hansen, J; Dalmose, A L; Rijkhoff, N J M; Sinkjaer, T

    2003-07-01

    The objective of this study was to evaluate the effect of automatic event-driven electrical stimulation on the dorsal penile/clitoral nerve for management of neurogenic detrusor overactivity in spinal cord injured subjects. In order to reach the objectives it was necessary to design and realize a portable device for ambulatory urodynamic studies which was able to activate an electrical stimulator when the detrusor pressure exceeded a certain threshold. The developed device was repeatedly tested in a healthy subject and subsequently tested in a spinal cord injured subject. In testing the automatic event-driven system in the spinal cord injured subject, detrusor contractions were successfully inhibited until a certain bladder volume was reached and no incontinence episodes were observed prior to disabling the system. The preliminary results indicate that automatic event-driven electrical stimulation on the dorsal penile/clitoral nerve can inhibit involuntary detrusor contractions in spinal cord injured subjects and hereby restore continence and increase bladder capacity.

  11. Experimental valitation of energy harvesting device for civil engineering applications

    NASA Astrophysics Data System (ADS)

    Jung, Hyung-Jo; Kim, In-Ho; Park, Jeongsu

    2012-04-01

    In the field of structural health monitoring using wireless sensors, considerable research attention has been recently given to vibration-based energy harvesting devices for exploring their feasibility as a power source of a wireless sensor node. Most of the previous studies have focused on lab-scale tests for performance validation. For real application, however, field tests on developed energy harvesting devices should be conducted, because their performance may be considerably affected by change in the testing environment. In this study, a new electromagnetic energy harvester is proposed, which is more suitable for civil engineering application, and the preliminary field test on a real cable-stayed bridge are conducted to validate its effectiveness.

  12. Tactile device utilizing a single magnetorheological sponge: experimental investigation

    NASA Astrophysics Data System (ADS)

    Kim, Soomin; Kim, Pyunghwa; Choi, Seung-Hyun; Oh, Jong-Seok; Choi, Seung-Bok

    2015-04-01

    In the field of medicine, several new areas have been currently introduced such as robot-assisted surgery. However, the major drawback of these systems is that there is no tactile communication between doctors and surgical sites. When the tactile system is brought up, telemedicine including telerobotic surgery can be enhanced much more than now. In this study, a new tactile device is designed using a single magnetorhological (MR) sponge cell to realize the sensation of human organs. MR fluids and an open celled polyurethane foam are used to propose the MR sponge cell. The viscous and elastic sensational behaviors of human organs are realized by the MR sponge cell. Before developing the tactile device, tactile sensation according to touch of human fingers are quantified in advance. The finger is then treated as a reduced beam bundle model (BBM) in which the fingertip is comprised of an elastic beam virtually. Under the reduced BBM, when people want to sense an object, the fingertip is investigated by pushing and sliding. Accordingly, while several magnitudes of magnetic fields are applied to the tactile device, normal and tangential reaction forces and bending moment are measured by 6-axis force/torque sensor instead of the fingertip. These measured data are used to compare with soft tissues. It is demonstrated that the proposed MR sponge cell can realize any part of the organ based on the obtained data.

  13. Comparing Spray Characteristics from Reynolds Averaged Navier-Stokes (RANS) National Combustion Code (NCC) Calculations Against Experimental Data for a Turbulent Reacting Flow

    NASA Technical Reports Server (NTRS)

    Iannetti, Anthony C.; Moder, Jeffery P.

    2010-01-01

    Developing physics-based tools to aid in reducing harmful combustion emissions, like Nitrogen Oxides (NOx), Carbon Monoxide (CO), Unburnt Hydrocarbons (UHC s), and Sulfur Dioxides (SOx), is an important goal of aeronautics research at NASA. As part of that effort, NASA Glenn Research Center is performing a detailed assessment and validation of an in-house combustion CFD code known as the National Combustion Code (NCC) for turbulent reacting flows. To assess the current capabilities of NCC for simulating turbulent reacting flows with liquid jet fuel injection, a set of Single Swirler Lean Direct Injection (LDI) experiments performed at the University of Cincinnati was chosen as an initial validation data set. This Jet-A/air combustion experiment operates at a lean equivalence ratio of 0.75 at atmospheric pressure and has a 4 percent static pressure drop across the swirler. Detailed comparisons of NCC predictions for gas temperature and gaseous emissions (CO and NOx) against this experiment are considered in a previous work. The current paper is focused on detailed comparisons of the spray characteristics (radial profiles of drop size distribution and at several radial rakes) from NCC simulations against the experimental data. Comparisons against experimental data show that the use of the correlation for primary spray break-up implemented by Raju in the NCC produces most realistic results, but this result needs to be improved. Given the single or ten step chemical kinetics models, use of a spray size correlation gives similar, acceptable results

  14. Design and construction of experimental device to study cryogen droplet deposition and heat transfer

    NASA Astrophysics Data System (ADS)

    Keller, Matthew; Aguilar, Guillermo; Nelson, J. Stuart

    2003-06-01

    Cryogen spray cooling (CSC) is used to pre-cool the epidermis during laser dermatological procedures such as treatment of port wine stain (PWS) birthmarks. It is known that PWS patients with medium to high epidermal melanin concentrations are at a high risk of epidermal thermal damage after laser irradiation. To avoid this complication, it is necessary to maximize CSC efficiency and, thus, essential to understand the mechanical and thermal interactions of cryogen droplets with the sprayed surface. It has been observed that cryogen sprays exhibit droplet rebound as droplets impinge on the skin surface. Studies of water droplet impact on hard surfaces have shown that droplet rebound may be suppressed by dissolving small amounts (a few percent) of diverse polymer or surfactant solutions prior to atomization. To investigate the possibility of suppressing the rebound of cryogen droplets in a similar way, we have constructed a device that allows observation of the impact, spreading, and rebound of individual water and cryogen droplets with and without these solutions, and their influence on cryogen/surface dynamics and heat transfer. Our preliminary studies show that dissolving a 4% non-ionic surfactant in water reduces droplet rebound and thickness of the residual liquid layer. The maximum spread of water droplets after impact can be described within 20% accuracy by a previously developed theoretical model. The same model provides an even more accurate prediction of the maximum spread of cryogen droplets. This study will aid the analysis of future results and design conditions of new studies, which will recreate conditions to determine if added surfactant solutions suppress droplet rebound and lead to improved CSC efficiency.

  15. "Teaching" an Industrial Robot To Spray

    NASA Technical Reports Server (NTRS)

    Evans, A. R.; Sweet, G. K.

    1982-01-01

    Teaching device, consisting of spacer rod or tube with three-pointed tip and line level, is used during pattern "teach-in" to make sure that robot manipulator holds spray gun perpendicular to surface to be sprayed and at right distance from it. For slanted surfaces angle adapter is added between spacer rod and line-level indicator. Angle is determined by slope of surface to be sprayed, thus allowing a perpendicular spray pattern against even slanted surfaces.

  16. Application of atmospheric solution precursor plasma spray to photocatalytic devices for small and medium industries in developing countries

    NASA Astrophysics Data System (ADS)

    Kindole, Dickson; Ando, Yasutaka

    2017-01-01

    For development of a functional film deposition process with high deposition rate, as a basic study, TiO2 films were deposited by atmospheric solution precursor plasma spray (ASPPS) process. Ethanol-diluted titanium tetraisobutoxide [TTIB: Ti(OC4H9)4] was used as a feedstock. To achieve a high plasma thermal energy at a low discharge power, N2-dominant Ar/N2 as the plasma working gas was used, for film deposition at various deposition distances. Consequently, photocatalytic TiO2 with a rutile/anatase mixture film structure was deposited evenly in this case. By conducting methylene blue decomposition and wettability tests, photocatalytic properties of the film were confirmed. When a TiO2 film was applied to photocatalytic dye-sensitized solar cells (DSSCs), the cells generated an electromotive force of 0.143V oc, which is close to those of commercial DSSCs. From these results, the ASPPS process was found to have high potential for high rate functional film deposition and was cost effective, making it suitable for developing countries.

  17. Experimental Confirmation of Water Column Natural Resonance Migration in a BBDB Device

    SciTech Connect

    Bull, Diana L.; Gunawan, Budi; Holmes, Brian

    2014-09-01

    Experiments were conducted with a Backward Bent Duct Buoy (BBDB) oscillating water column wave energy conversion device with a scaling factor of 50 at HMRC at University College Cork, Ireland. Results were compared to numerical performance models. This work experimentally verified the migration of the natural resonance location of the water column due to hydrodynamic coupling for a floating non- axisymmetric device without a power conversion chain PCC present. In addition, the experimental results verified the performance model with a PCC of the same non- axisymmetric device when both floating and grounded.

  18. Electrokinetically pumped high pressure sprays

    DOEpatents

    Schoeniger, Joseph S.; Paul, Phillip H.; Schoeniger, Luke

    2002-01-01

    An electrokinetic pump capable of producing high pressure is combined with a nozzle having a submicron orifice to provide a high pressure spray device. Because of its small size, the device can be contained within medical devices such as an endoscope for delivering biological materials such as DNA, chemo therapeutic agents, or vaccines to tissues and cells.

  19. Electrokinetically pumped high pressure sprays

    DOEpatents

    Schoeniger, Joseph S.; Paul, Phillip H.; Schoeniger, Luke

    2005-11-01

    An electrokinetic pump capable of producing high pressure is combined with a nozzle having a submicron orifice to provide a high pressure spray device. Because of its small size, the device can be contained within medical devices such as an endoscope for delivering biological materials such as DNA, chemo therapeutic agents, or vaccines to tissues and cells.

  20. An experimental nonlinear low dynamic stiffness device for shock isolation

    NASA Astrophysics Data System (ADS)

    Francisco Ledezma-Ramirez, Diego; Ferguson, Neil S.; Brennan, Michael J.; Tang, Bin

    2015-07-01

    The problem of shock generated vibration is very common in practice and difficult to isolate due to the high levels of excitation involved and its transient nature. If not properly isolated it could lead to large transmitted forces and displacements. Typically, classical shock isolation relies on the use of passive stiffness elements to absorb energy by deformation and some damping mechanism to dissipate residual vibration. The approach of using nonlinear stiffness elements is explored in this paper, focusing in providing an isolation system with low dynamic stiffness. The possibilities of using such a configuration for a shock mount are studied experimentally following previous theoretical models. The model studied considers electromagnets and permanent magnets in order to obtain nonlinear stiffness forces using different voltage configurations. It is found that the stiffness nonlinearities could be advantageous in improving shock isolation in terms of absolute displacement and acceleration response when compared with linear elastic elements.

  1. Design of a Cascade Controller for a Flexible Spray Boom

    NASA Astrophysics Data System (ADS)

    Ramon, H.; De Baerdemaeker, J.; van Brussel, H.

    1996-03-01

    Longitudinal accelerations and yawning angular accelerations of a tractor induce horizontal flexible spray boom deformations which cannot be reduced sufficiently by simple structural adaptations. An electro-hydraulic control system has therefore been developed in order to attenuate the negative effect of longitudinal tractor accelerations on a spray boom. The linear quadratic Gaussian theory with loop transfer recovery has been used to design the compensator. Four different variants of the compensator are implemented in an experimental set-up to test the performance and the robustness of the feedback system and to investigate the applicability of the electro-hydraulic devices in active vibration control.

  2. RSFQ logic devices; non-linear properties and experimental investigations

    NASA Astrophysics Data System (ADS)

    Mygind, Jesper

    1998-05-01

    Rapid Single Flux Quantum (RSFQ) logic has a great potential as fast digital and high frequency analog electronics. Several Logic/Memory base elements and integrated sub-systems in the RSFQ family have been devised and tested since the pioneering work in the mid 1980s by K. K. Likharev's group at Moscow State University [1,2]. It is argumented why the RSFQ digital circuits are superior to the voltage state family circuits, which were utilised in the first development of Josephson logic. Also the parameter space for operation of the 1-D RSFQ transmission line is discussed. Presently most RSFQ circuits are made with low-Tc superconductors using the now mature whole-wafer NbAlOxNb technology, which allows for large and densely packed integrated circuits. Recently, a few operational high-Tc RSFQ circuits have been reported. An important development within the last two years is the advent of general-purpose on-chip bit-by-bit verification test systems. Timing of RSFQ circuits and a few recent RSFQ "highlights" are briefly mentioned. Basically the RSFQ technology appears "ready" for widespread industrial use. One of the key components is the RSFQ transmission line, which can both generate and transmit SFQ pulses. In order to demonstrate the importance of the fluxon dynamics we discuss a new phenomenon observed in a parallel array of identical junctions. Steps with extremely low differential resistance in the I-V characteristic are found to be due to the self-induced magnetic field produced by the edge current fed to the array. The underlying mechanism is that the nonuniform field divides the moving fluxon into "domains" covering several (unit) cells. The experimental/numerical results illustrate practical and may be more fundamental limits to RSFQ electronics.

  3. Power Packaging of Spray-Cooled SiC Devices for High Temperature and High Voltage Operation: Final Report

    DTIC Science & Technology

    2008-07-01

    removes the native oxide present on Al and coats base metal with a thin layer of zinc . Later when the zincated diode is immersed in the EN plating...solution, the zinc is etched away and around 4 pin of Ni is plated on to Al. The thickness of Ni layer depends on the time that the device is left in the...compared with the traditional ferrite and Litz wire structures to provide an order of magnitude increase in power density. System Description Fig. 3.12

  4. Experimental and Theoretical Measurements of Concentration Distributions in Acoustic Focusing Devices

    SciTech Connect

    Rose, K A; Fisher, K; Jung, B; Ness, K; Mariella Jr., R P

    2008-06-16

    We describe a modeling approach to capture the particle motion within an acoustic focusing microfluidic device. Our approach combines finite element models for the acoustic forces with analytical models for the fluid motion and uses these force fields to calculate the particle motion in a Brownian dynamics simulation. We compare results for the model with experimental measurements of the focusing efficiency within a microfabricated device. The results show good qualitative agreement over a range of acoustic driving voltages and particle sizes.

  5. Compaction of spray-dried ceramic powders: An experimental study of the factors that control green density

    SciTech Connect

    Readey, M.J.; Mahoney, F.M.

    1995-11-01

    The pressure-compaction response of a spray-dried, 94% alumina powder containing several percent of a polymeric binder was investigated as a function of die diameter and compact aspect ratio. The results show that the die fill density decreases markedly with decreasing die diameter and aspect ratio, while the final green density (at 120 MPa) decreases only slightly under the same conditions. These results suggest that the ratio of the initial compact dimensions to the size of the granules may be much more important than previously considered.

  6. Influence of oxygen on heat transfer by convection in the experimental device

    NASA Astrophysics Data System (ADS)

    DzurÅák, Róbert; Kizek, Ján; Jablonský, Gustáv

    2017-09-01

    The aim of this paper is to analyze the influence of flue gas flow on the heat exchange in experimental devices. The authors focused on the analysis of combustion gases produced by combustion of natural gas at various enrichment of the oxidizing agent by means of oxygen. By analyzing the flue gas flow, it is possible to detect changes in velocity fields at a given concentration of oxygen in the oxidizing agent. In the flow analysis, a mathematical model of an experimental device was developed in the ANSYS program, which served to visualize the change of velocity fields for the whirling burner mouth.

  7. Estimation of equivalence ratio distribution in diesel spray using a computational fluid dynamics

    NASA Astrophysics Data System (ADS)

    Suzuki, Yasumasa; Tsujimura, Taku; Kusaka, Jin

    2014-08-01

    It is important to understand the mechanism of mixing and atomization of the diesel spray. In addition, the computational prediction of mixing behavior and internal structure of a diesel spray is expected to promote the further understanding about a diesel spray and development of the diesel engine including devices for fuel injection. In this study, we predicted the formation of diesel fuel spray with 3D-CFD code and validated the application by comparing experimental results of the fuel spray behavior and the equivalence ratio visualized by Layleigh-scatter imaging under some ambient, injection and fuel conditions. Using the applicable constants of KH-RT model, we can predict the liquid length spray on a quantitative level. under various fuel injection, ambient and fuel conditions. On the other hand, the change of the vapor penetration and the fuel mass fraction and equivalence ratio distribution with change of fuel injection and ambient conditions quantitatively. The 3D-CFD code used in this study predicts the spray cone angle and entrainment of ambient gas are predicted excessively, therefore there is the possibility of the improvement in the prediction accuracy by the refinement of fuel droplets breakup and evaporation model and the quantitative prediction of spray cone angle.

  8. Experimental investigation of effect of surface gravity waves and spray on heat and momentum flux at strong wind conditions

    NASA Astrophysics Data System (ADS)

    Troitskaya, Yuliya; Sergeev, Daniil; Vdovin, Maxim; Kandaurov, Alexander; Ermakova, Olga; Kazakov, Vassily

    2015-04-01

    The most important characteristics that determine the interaction between atmosphere and ocean are fluxes of momentum, heat and moisture. For their parameterization the dimensionless exchange coefficients (the surface drag coefficient CD and the heat transfer coefficient or the Stanton number CT) are used. Numerous field and laboratory experiments show that CD increases with increasing wind speed at moderate and strong wind, and as it was shows recently CD decreases at hurricane wind speed. Waves are known to increase the sea surface resistance due to enhanced form drag, the sea spray is considered as a possible mechanism of the 'drag reduction' at hurricane conditions. The dependence of heat transfer coefficient CD on the wind speed is not so certain and the role of the mechanism associated with the wave disturbances in the mass transfer is not completely understood. Observations and laboratory data show that this dependence is weaker than for the CD, and there are differences in the character of the dependence in different data sets. The purpose of this paper is investigation of the effect of surface waves on the turbulent exchange of momentum and heat within the laboratory experiment, when wind and wave parameters are maintained and controlled. The effect of spray on turbulent exchange at strong winds is also estimated. A series of experiments to study the processes of turbulent exchange of momentum and heat in a stably stratified temperature turbulent boundary layer air flow over waved water surface were carried out at the Wind - wave stratified flume of IAP RAS, the peculiarity of this experiment was the option to change the surface wave parameters regardless of the speed of the wind flow in the channel. For this purpose a polyethylene net with the variable depth (0.25 mm thick and a cell of 1.6 mm × 1.6mm) has been stretched along the channel. The waves were absent when the net was located at the level of the undisturbed water surface, and had maximum

  9. Experimental and numerical studies of a microfluidic device with compliant chambers for flow stabilization

    NASA Astrophysics Data System (ADS)

    Iyer, V.; Raj, A.; Annabattula, R. K.; Sen, A. K.

    2015-07-01

    This paper reports experimental and numerical studies of a passive microfluidic device that stabilizes a pulsating incoming flow and delivers a steady flow at the outlet. The device employs a series of chambers along the flow direction with a thin polymeric membrane (of thickness 75-250 µm) serving as the compliant boundary. The deformation of the membrane allows accumulation of fluid during an overflow and discharge of fluid during an underflow for flow stabilization. Coupled fluid-structure simulations are performed using Mooney-Rivlin formulations to account for a thin hyperelastic membrane material undergoing large deformations to accurately predict the device performance. The device was fabricated with PDMS as the substrate material and thin PDMS membrane as the compliant boundary. The performance of the device is defined in terms of a parameter called ‘Attenuation Factor (AF)’. The effect of various design parameters including membrane thickness, elastic modulus, chamber size and number of chambers in series as well as operating conditions including the outlet pressure, mean input flow rate, fluctuation amplitude and frequency on the device performance were studied using experiments and simulations. The simulation results successfully confront the experimental data (within 10%) which validates the numerical simulations. The device was used at the exit of a PZT actuated valveless micropump to take pulsating flow at the upstream and deliver steady flow downstream. The amplitude of the pulsating flow delivered by the micropump was significantly reduced (AF = 0.05 for a device with three 4 mm chambers) but at the expense of a reduction in the pressure capability (<20%). The proposed device could potentially be used for reducing flow pulsations in practical microfluidic circuits.

  10. Plasma spraying with wire feedstock

    SciTech Connect

    Scholl, M.

    1994-12-31

    Plasma spraying has been limited to using powder feedstocks for a number of reasons. One limitation has been the low energy output of conventional plasma guns. The advent of high energy plasma spraying (HEPS) devices and the associated technology has effectively removed this functional limitation. With HEPS, the combination of high gas velocities and high thermal plasma temperatures coupled with a large exit gas volume enables wire and rod feedstocks to be effectively utilized. Rather than a bulk melting mechanism, a model based on ablation phenomena is considered. The paper examines an analysis of melting phenomena and presents a simple model for molten droplet formation for plasma spraying using wire feedstocks.

  11. Measuring water ingestion from spray exposures.

    PubMed

    Sinclair, Martha; Roddick, Felicity; Nguyen, Thang; O'Toole, Joanne; Leder, Karin

    2016-08-01

    Characterisation of exposure levels is an essential requirement of health risk assessment; however for water exposures other than drinking, few quantitative exposure data exist. Thus, regulatory agencies must use estimates to formulate policy on treatment requirements for non-potable recycled water. We adapted the use of the swimming pool chemical cyanuric acid as a tracer of recreational water ingestion to permit detection of small water volumes inadvertently ingested from spray exposures. By using solutions of 700-1000 mg/L cyanuric acid in an experimental spray exposure scenario, we were able to quantify inadvertent water ingestion in almost 70% of participants undertaking a 10 min car wash activity using a high pressure spray device. Skin absorption was demonstrated to be negligible under the experimental conditions, and the measured ingestion volumes ranged from 0.06 to 3.79 mL. This method could be applied to a range of non-potable water use activities to generate exposure data for risk assessment processes. The availability of such empirical measurements will provide greater assurance to regulatory agencies and industry that potential health risks from exposure to non-potable water supplies are well understood and adequately managed to protect public health.

  12. 42 CFR 405.209 - Payment for a non-experimental/investigational (Category B) device.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Payment for a non-experimental/investigational (Category B) device. 405.209 Section 405.209 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICARE PROGRAM FEDERAL HEALTH INSURANCE FOR THE AGED AND DISABLED Medical Services Coverage Decisions...

  13. Development of Improved Microwave Dielectric Materials and Devices using Advanced Experimental and Theoretical Methods

    DTIC Science & Technology

    2008-04-17

    REPORT Development of improved microwave dielectric materials and devices using advanced experimental and theoretical methods 14. ABSTRACT 16. SECURITY... methods Report Title ABSTRACT Our work has made important progress towards developing a fundamental understanding of the microscopic mechanism that causes...electromagnetic Band Gap Filters using advanced ceramic injection molding methods ”, Semiconductor Research Corporation Packaging and Interconnect Summer

  14. Security analysis on some experimental quantum key distribution systems with imperfect optical and electrical devices

    NASA Astrophysics Data System (ADS)

    Liang, Lin-Mei; Sun, Shi-Hai; Jiang, Mu-Sheng; Li, Chun-Yan

    2014-10-01

    In general, quantum key distribution (QKD) has been proved unconditionally secure for perfect devices due to quantum uncertainty principle, quantum noncloning theorem and quantum nondividing principle which means that a quantum cannot be divided further. However, the practical optical and electrical devices used in the system are imperfect, which can be exploited by the eavesdropper to partially or totally spy the secret key between the legitimate parties. In this article, we first briefly review the recent work on quantum hacking on some experimental QKD systems with respect to imperfect devices carried out internationally, then we will present our recent hacking works in details, including passive faraday mirror attack, partially random phase attack, wavelength-selected photon-number-splitting attack, frequency shift attack, and single-photon-detector attack. Those quantum attack reminds people to improve the security existed in practical QKD systems due to imperfect devices by simply adding countermeasure or adopting a totally different protocol such as measurement-device independent protocol to avoid quantum hacking on the imperfection of measurement devices [Lo, et al., Phys. Rev. Lett., 2012, 108: 130503].

  15. Liquid spray cooling of a heated surface

    NASA Technical Reports Server (NTRS)

    Grissom, W. M.; Wierum, F. A.

    1981-01-01

    The lowest surface temperature possible for the existance of spray evaporative cooling is determined experimentally to be a linear function of the impinging spray mass flux. A conduction-controlled analytical model of droplet evaporation gives fairly good agreement with experimental measurements at atmospheric pressure. At reduced pressures droplet evaporation rates are decreased significantly such that an optimum operating pressure exists for each desired surface heat flux. The initiation of the 'Leidenfrost state' provides the upper surface temperature bound for spray evaporative cooling.

  16. Liquid spray cooling of a heated surface

    NASA Technical Reports Server (NTRS)

    Grissom, W. M.; Wierum, F. A.

    1981-01-01

    The lowest surface temperature possible for the existance of spray evaporative cooling is determined experimentally to be a linear function of the impinging spray mass flux. A conduction-controlled analytical model of droplet evaporation gives fairly good agreement with experimental measurements at atmospheric pressure. At reduced pressures droplet evaporation rates are decreased significantly such that an optimum operating pressure exists for each desired surface heat flux. The initiation of the 'Leidenfrost state' provides the upper surface temperature bound for spray evaporative cooling.

  17. Influence of Cold-Sprayed, Warm-Sprayed, and Plasma-Sprayed Layers Deposition on Fatigue Properties of Steel Specimens

    NASA Astrophysics Data System (ADS)

    Cizek, J.; Matejkova, M.; Dlouhy, I.; Siska, F.; Kay, C. M.; Karthikeyan, J.; Kuroda, S.; Kovarik, O.; Siegl, J.; Loke, K.; Khor, Khiam Aik

    2015-06-01

    Titanium powder was deposited onto steel specimens using four thermal spray technologies: plasma spray, low-pressure cold spray, portable cold spray, and warm spray. The specimens were then subjected to strain-controlled cyclic bending test in a dedicated in-house built device. The crack propagation was monitored by observing the changes in the resonance frequency of the samples. For each series, the number of cycles corresponding to a pre-defined specimen cross-section damage was used as a performance indicator. It was found that the grit-blasting procedure did not alter the fatigue properties of the steel specimens (1% increase as compared to as-received set), while the deposition of coatings via all four thermal spray technologies significantly increased the measured fatigue lives. The three high-velocity technologies led to an increase of relative lives to 234% (low-pressure cold spray), 210% (portable cold spray), and 355% (warm spray) and the deposition using plasma spray led to an increase of relative lives to 303%. The observed increase of high-velocity technologies (cold and warm spray) could be attributed to a combination of homogeneous fatigue-resistant coatings and induction of peening stresses into the substrates via the impingement of the high-kinetic energy particles. Given the intrinsic character of the plasma jet (low-velocity impact of semi/molten particles) and the mostly ceramic character of the coating (oxides, nitrides), a hypothesis based on non-linear coatings behavior is provided in the paper.

  18. Experimental and Numerical Analysis of the Effects of Curing Time on Tensile Mechanical Properties of Thin Spray-on Liners

    NASA Astrophysics Data System (ADS)

    Guner, D.; Ozturk, H.

    2016-08-01

    The effects of curing time on tensile elastic material properties of thin spray-on liners (TSLs) were investigated in this study. Two different TSL products supplied by two manufacturers were tested comparatively. The "dogbone" tensile test samples that were prepared in laboratory conditions with different curing times (1, 7, 14, 21, and 28 days) were tested based on ASTM standards. It was concluded that longer curing times improves the tensile strength and the Young's Modulus of the TSLs but decreases their elongation at break. Moreover, as an additional conclusion of the testing procedure, it was observed that during the tensile tests, the common malpractice of measuring sample displacement from the grips of the loading machine with a linear variable displacement transducer versus the sample's gauge length had a major impact on modulus and deformation determination of TSLs. To our knowledge, true stress-strain curves were generated for the first time in TSL literature within this study. Numerical analyses of the laboratory tests were also conducted using Particle Flow Code in 2 Dimensions (PFC2D) in an attempt to guide TSL researchers throughout the rigorous PFC simulation process to model support behaviour of TSLs. A scaling coefficient between macro- and micro-properties of PFC was calculated which will help future TSL PFC modellers mimic their TSL behaviours for various tensile loading support scenarios.

  19. An Experimental Device for Generating High Frequency Perturbations in Supersonic Wind Tunnels

    NASA Technical Reports Server (NTRS)

    Melcher, Kevin J.; Ibrahim, Mounir B.

    1996-01-01

    This paper describes the analytical study of a device that has been proposed as a mechanism for generating gust-like perturbations in supersonic wind tunnels. The device is envisioned as a means to experimentally validate dynamic models and control systems designed for high-speed inlets. The proposed gust generator is composed of two flat trapezoidal plates that modify the properties of the flow ingested by the inlet. One plate may be oscillated to generate small perturbations in the flow. The other plate is held stationary to maintain a constant angle-of-attack. Using an idealized approach, design equations and performance maps for the new device were developed from the compressible flow relations. A two-dimensional CFD code was used to confirm the correctness of these results. The idealized approach was then used to design and evaluate a new gust generator for a 3.05-meter by 3.05-meter (10-foot by 10-foot) supersonic wind tunnel.

  20. Feeding Experimentation Device (FED): Construction and Validation of an Open-source Device for Measuring Food Intake in Rodents.

    PubMed

    Nguyen, Katrina P; Ali, Mohamed A; O'Neal, Timothy J; Szczot, Ilona; Licholai, Julia A; Kravitz, Alexxai V

    2017-02-21

    Food intake measurements are essential for many research studies. Here, we provide a detailed description of a novel solution for measuring food intake in mice: the Feeding Experimentation Device (FED). FED is an open-source system that was designed to facilitate flexibility in food intake studies. Due to its compact and battery powered design, FED can be placed within standard home cages or other experimental equipment. Food intake measurements can also be synchronized with other equipment in real-time via FED's transistor-transistor logic (TTL) digital output, or in post-acquisition processing as FED timestamps every event with a real-time clock. When in use, a food pellet sits within FED's food well where it is monitored via an infrared beam. When the pellet is removed by the mouse, FED logs the timestamp onto its internal secure digital (SD) card and dispenses another pellet. FED can run for up to 5 days before it is necessary to charge the battery and refill the pellet hopper, minimizing human interference in data collection. Assembly of FED requires minimal engineering background, and off-the-shelf materials and electronics were prioritized in its construction. We also provide scripts for analysis of food intake and meal patterns. Finally, FED is open-source and all design and construction files are online, to facilitate modifications and improvements by other researchers.

  1. Combustion of LOX with H2(sub g) under subcritical, critical, and supercritical conditions and experimental observation of dense spray and mixing of impinging jets

    NASA Technical Reports Server (NTRS)

    Kuo, Kenneth K.; Hsieh, W. H.; Yang, A. S.; Brown, J. J.; Cheung, F. B.; Woodward, R. D.; Kline, M. C.

    1992-01-01

    Progress made during the period of February 1 to October 15, 1992 is reported. The overall objective of Task 1 of the investigation is to achieve a better understanding of the combustion processes of liquid oxygen and gaseous hydrogen under subcritical, critical, and supercritical conditions. Specific objectives of the research program are: (1) to determine the evaporation- and burning-rate characteristics of LOX in hydrogen/helium environments under broad ranges of operating conditions; (2) to measure species concentration profile and surface temperature of LOX employing the gas chromatography and fine-wire thermocouples under non-reacting flow situations; (3) to perform a fugacity-based multicomponent thermodynamic phase equilibrium analysis for examining the high-pressure vapor-liquid equilibrium behavior at the liquid surface of LOX; (4) to formulate and solve a theoretical model for simulating the evaporation and combustion processes in a LOX/H2/He system; and (5) to validate the theoretical model with the measured experimental data. Task 2 of the investigation is described. Observation of a like-on-like injector element in the near-injector region performed in the previous phase of this project has identified the existence of a high Reynolds number regime in which the pre-impingement jets are fully turbulent and undergoing surface breakup. The new spray regime, which has not been observed by previous investigators, is characterized by the presence of many fine droplets and the disappearance of the well-defined liquid breakup wave pattern in the post-impingement region. It is speculated that a cavitating region may be present within the orifice so that it could induce strong turbulence, leading to an onset of atomization of the jets prior to impingement. To further investigate the dense spray behavior of the impinging jets in the high Reynolds number region, experiments were conducted using Plexiglas injector components for direct internal flow observation

  2. Experimental generation of Laguerre-Gaussian beam using digital micromirror device.

    PubMed

    Ren, Yu-Xuan; Li, Ming; Huang, Kun; Wu, Jian-Guang; Gao, Hong-Fang; Wang, Zi-Qiang; Li, Yin-Mei

    2010-04-01

    A digital micromirror device (DMD) modulates laser intensity through computer control of the device. We experimentally investigate the performance of the modulation property of a DMD and optimize the modulation procedure through image correction. Furthermore, Laguerre-Gaussian (LG) beams with different topological charges are generated by projecting a series of forklike gratings onto the DMD. We measure the field distribution with and without correction, the energy of LG beams with different topological charges, and the polarization property in sequence. Experimental results demonstrate that it is possible to generate LG beams with a DMD that allows the use of a high-intensity laser with proper correction to the input images, and that the polarization state of the LG beam differs from that of the input beam.

  3. Experimental characterisation of PD SOI MOSFET devices fabricated with diamond-shaped body contact

    NASA Astrophysics Data System (ADS)

    Daghighi, Arash; Osman, Mohamed A.

    2011-06-01

    The design of diamond-shaped body-contacted (DSBC) devices using standard layers in a 0.35 µm silicon-on-insulator (SOI) complementary metal-oxide-semiconductor process is described in this article. The technology is based on a manufacturable partially depleted SOI process targeted for radio frequency applications. The experimental measurements of drain induced barrier lowering for the fabricated DSBC structure showed suppression of floating body effects (FBE) at the promising rate of 24 mV/V. The measurement results confirmed current drive (I DS) improvement by 25% at V DS = 1.5 V and V GS = 1.5 V compared to conventional body-tied-source (BTS) device. A constant and steady output conductance (g DS) in the saturation region was observed for the DSBC structure. The gate trans-conductance (g m) is improved by 34% at V DS = 1.5 V and V GS = 1.5 V compared to conventional BTS device. Three-dimensional device simulation provides insight on FBE suppression and channel current improvement. Experimental results confirmed the area efficiency of the DSBC structure and its excellent current drive performance.

  4. Experimentally validated quantitative linear model for the device physics of elastomeric microfluidic valves

    NASA Astrophysics Data System (ADS)

    Kartalov, Emil P.; Scherer, Axel; Quake, Stephen R.; Taylor, Clive R.; Anderson, W. French

    2007-03-01

    A systematic experimental study and theoretical modeling of the device physics of polydimethylsiloxane "pushdown" microfluidic valves are presented. The phase space is charted by 1587 dimension combinations and encompasses 45-295μm lateral dimensions, 16-39μm membrane thickness, and 1-28psi closing pressure. Three linear models are developed and tested against the empirical data, and then combined into a fourth-power-polynomial superposition. The experimentally validated final model offers a useful quantitative prediction for a valve's properties as a function of its dimensions. Typical valves (80-150μm width) are shown to behave like thin springs.

  5. Junction and Back Contact Properties of Spray-Deposited M/SnS/In2S3/SnO2:F/Glass (M = Cu, Graphite) Devices: Considerations to Improve Photovoltaic Performance

    NASA Astrophysics Data System (ADS)

    Patel, Malkeshkumar; Ray, Abhijit

    2015-01-01

    SnS/In2S3 heterojunction devices were fabricated entirely by chemical spray pyrolysis in a superstrate configuration on SnO2:F/glass. The SnS/In2S3 junction was found to exhibit strong rectification behavior, and the Mott-Schottky characteristics showed it was abrupt. The photovoltaic behavior of the junction was investigated under air mass 1.5G illumination, showing a short-circuit current of 4.8 mA/cm2 and an open-circuit voltage of 0.29 V, reportedly the highest to date among similar devices with a Cd-free buffer layer and processed by a nonvacuum technique. However, the device suffers from low fill factor due to high series resistance originating from interface inhomogeneities. A Cu back contact was associated with a low level of inhomogeneities at the interface, as demonstrated by impedance analysis.

  6. Design, characterization, and experimental use of the second generation MEMS acoustic emission device

    NASA Astrophysics Data System (ADS)

    Ozevin, Didem; Greve, David W.; Oppenheim, Irving J.; Pessiki, Stephen

    2005-05-01

    We describe the design, fabrication, testing and application (in structural experiments) of our 2004 (second generation) MEMS device, designed for acoustic emission sensing based upon experiments with our 2002 (first generation) device. Both devices feature a suite of resonant-type transducers in the frequency range between 100 kHz and 1 MHz. The 2002 device was designed to operate in an evacuated housing because of high squeeze film damping, as confirmed in our earlier experiments. In additional studies involving the 2002 device, experimental simulation of acoustic emissions in a steel plate, using pencil lead break or ball impact loading, showed that the transducers in the frequency range of 100 kHz-500 kHz presented clearer output signals than the transducers with frequencies higher than 500 kHz. Using the knowledge gained from the 2002 device, we designed and fabricated our second generation device in 2004 using the multi-user polysilicon surface micromachining (MUMPs) process. The 2004 device has 7 independent capacitive type transducers, compared to 18 independent transducers in the 2002 device, including 6 piston type transducers in the frequency range of 100 kHz to 500 kHz and 1 piston type transducer at 1 MHz to capture high frequency information. Piston type transducers developed in our research have two uncoupled modes so that twofold information can be acquired from a single transducer. In addition, the piston shape helps to reduce residual stress effect of surface micromachining process. The center to center distance between etch holes in the vibrating plate was reduced from 30 μm to 13 μm, in order to reduce squeeze film damping. As a result, the Q factor under atmospheric pressure for the 100 kHz transducer was increased to 2.37 from 0.18, and therefore the vacuum housing has been eliminated from the 2004 device. Sensitivities of transducers were also increased, by enlarging transducer area, in order to capture significant small amplitude acoustic

  7. Dusty Plasma Experimental (DPEx) device for complex plasma experiments with flow

    NASA Astrophysics Data System (ADS)

    Jaiswal, S.; Bandyopadhyay, P.; Sen, A.

    2015-11-01

    A versatile table-top dusty plasma experimental device to study flow induced excitations of linear and nonlinear waves/structures in a complex plasma is presented. In this Π-shaped apparatus, a DC glow discharge plasma is produced between a disc shaped anode and a grounded long cathode tray by applying a high voltage DC in the background of a neutral gas (argon) and subsequently a dusty plasma is created by introducing micron sized dust particles that get charged and levitated in the sheath region. A flow of the dust particles is induced in a controlled manner by adjusting the pumping speed and the gas flow rate into the device. A full characterisation of the plasma, using Langmuir and emissive probe data, and that of the dusty plasma using particle tracking data with the help of an idl based (super) Particle Identification and Tracking (sPIT) code is reported. Experimental results on the variation of the dust flow velocity as a function of the neutral pressure and the gas flow rate are given. The neutral drag force acting on the particles and the Epstein coefficient are estimated from the initial acceleration of the particles. The potential experimental capabilities of the device for conducting fundamental studies of flow induced instabilities are discussed.

  8. Development of a radial ventricular assist device using numerical predictions and experimental haemolysis.

    PubMed

    Carswell, Dave; Hilton, Andy; Chan, Chris; McBride, Diane; Croft, Nick; Slone, Avril; Cross, Mark; Foster, Graham

    2013-08-01

    The objective of this study was to demonstrate the potential of Computational Fluid Dynamics (CFD) simulations in predicting the levels of haemolysis in ventricular assist devices (VADs). Three different prototypes of a radial flow VAD have been examined experimentally and computationally using CFD modelling to assess device haemolysis. Numerical computations of the flow field were computed using a CFD model developed with the use of the commercial software Ansys CFX 13 and a set of custom haemolysis analysis tools. Experimental values for the Normalised Index of Haemolysis (NIH) have been calculated as 0.020 g/100 L, 0.014 g/100 L and 0.0042 g/100 L for the three designs. Numerical analysis predicts an NIH of 0.021 g/100 L, 0.017 g/100 L and 0.0057 g/100 L, respectively. The actual differences between experimental and numerical results vary between 0.0012 and 0.003 g/100 L, with a variation of 5% for Pump 1 and slightly larger percentage differences for the other pumps. The work detailed herein demonstrates how CFD simulation and, more importantly, the numerical prediction of haemolysis may be used as an effective tool in order to help the designers of VADs manage the flow paths within pumps resulting in a less haemolytic device.

  9. Highly precise experimental device for determining the heat capacity of liquids under pressure

    SciTech Connect

    Gonzalez-Salgado, D.; Valencia, J. L.; Troncoso, J.; Carballo, E.; Peleteiro, J.; Romani, L.; Bessieres, D.

    2007-05-15

    An experimental device for making isobaric heat capacity measurements of liquids under pressure is presented. The device is an adaptation of the Setaram micro-DSC II atmospheric-pressure microcalorimeter, including modifications of vessels and a pressure line allowing the pressure in the measurement system to be set, controlled, and stabilized. The high sensitivity of the apparatus combined with a suitable calibration procedure allows very accurate heat capacity measurements under pressure to be made. The relative uncertainty in the isobaric molar heat capacity measurements provided by the new device is estimated to be 0.08% at atmospheric pressure and 0.2% at higher levels. The device was validated from isobaric molar heat capacity measurements for hexane, nonane, decane, undecane, dodecane, and tridecane, all of which were highly consistent with reported data. It also possesses a high sensitivity as reflected in its response to changes in excess isobaric molar heat capacity with pressure, which were examined in this work for the first time by making heat capacity measurements throughout the composition range of the 1-hexanol+n-hexane system. Finally, preliminary measurements at several pressures near the critical conditions for the nitromethane+2-butanol binary system were made that testify to the usefulness of the proposed device for studying critical phenomena in liquids under pressure.

  10. Comparison and experimental validation of fluid dynamic numerical models for a clinical ventricular assist device.

    PubMed

    Zhang, Jiafeng; Zhang, Pei; Fraser, Katharine H; Griffith, Bartley P; Wu, Zhongjun J

    2013-04-01

    With the recent advances in computer technology, computational fluid dynamics (CFDs) has become an important tool to design and improve blood-contacting artificial organs, and to study the device-induced blood damage. Commercial CFD software packages are readily available, and multiple CFD models are provided by CFD software developers. However, the best approach of using CFD effectively to characterize fluid flow and to predict blood damage in these medical devices remains debatable. This study aimed to compare these CFD models and provide useful information on the accuracy of each model in modeling blood flow in circulatory assist devices. The laminar and five turbulence models (Spalart-Allmaras, k-ε (k-epsilon), k-ω (k-omega), SST [Menter's Shear Stress Transport], and Reynolds Stress) were implemented to predict blood flow in a clinically used circulatory assist device, the CentriMag centrifugal blood pump. In parallel, a transparent replica of the CentriMag pump was constructed and selected views of the flow fields were measured with digital particle image velocimetry (DPIV). CFD results were compared with the DPIV experimental results. Compared with the experiment, all the selected CFD models predicted the flow pattern fairly well except the area of the outlet. However, quantitatively, the laminar model results were the most deviated from the experimental data. On the other hand, k-ε renormalization group theory models and Reynolds Stress model are the most accurate. In conclusion, for the circulatory assist devices, turbulence models provide more accurate results than the laminar model. Among the selected turbulence models, k-ε and Reynolds Stress Method models are recommended.

  11. Comparison of fluid dynamic numerical models for a clinical ventricular assist device and experimental validation

    PubMed Central

    Zhang, Jiafeng; Zhang, Pei; Fraser, Katharine H.; Griffith, Bartley P.; Wu, Zhongjun J.

    2012-01-01

    With the recent advances in computer technology, computational fluid dynamics (CFD) has become an important tool to design and improve blood contacting artificial organs, and to study the device-induced blood damage. Commercial CFD software packages are readily available, and multiple CFD models are provided by CFD software developers. However, the best approach of using CFD effectively to characterize fluid flow and to predict blood damage in these medical devices remains debatable. This study aimed to compare these CFD models and provide useful information on the accuracy of each model in modeling blood flow in circulatory assist devices. The laminar and five turbulence models (Spalart-Allmaras, k-ε (k-epsilon), k-ω (k-omega), SST (Menter’s Shear Stress Transport), and Reynolds Stress) were implemented to predict blood flow in a clinically used circulatory assist device, CentriMag® centrifugal blood pump (Thoratec, MA). In parallel, a transparent replica of the CentriMag® pump was constructed and selected views of the flow fields were measured with digital particle image velocimetry (DPIV). CFD results were compared with the DPIV experimental results. Compared with the experiment, all the selected CFD models predicted the flow pattern fairly well except the area of the outlet. However, quantitatively, the laminar model results were the most deviated from the experimental data. On the other hand, k-ε RNG models and Reynolds Stress model are the most accurate. In conclusion, for the circulatory assist devices, turbulence models provide more accurate results than laminar model. Among the selected turbulence models, k-ε and Reynolds Stress Method models are recommended. PMID:23441681

  12. An experimental and theoretical evaluation of increased thermal diffusivity phase change devices

    NASA Technical Reports Server (NTRS)

    White, S. P.; Golden, J. O.; Stermole, F. J.

    1972-01-01

    This study was to experimentally evaluate and mathematically model the performance of phase change thermal control devices containing high thermal conductivity metal matrices. Three aluminum honeycomb filters were evaluated at five different heat flux levels using n-oct-adecane as the test material. The system was mathematically modeled by approximating the partial differential equations with a three-dimensional implicit alternating direction technique. The mathematical model predicts the system quite well. All of the phase change times are predicted. The heating of solid phase is predicted exactly while there is some variation between theoretical and experimental results in the liquid phase. This variation in the liquid phase could be accounted for by the fact that there are some heat losses in the cell and there could be some convection in the experimental system.

  13. Experimental demonstration of subwavelength domino plasmon devices for compact high-frequency circuit.

    PubMed

    Ma, Y G; Lan, L; Zhong, S M; Ong, C K

    2011-10-24

    In optical frequency, surface plasmons of metal provide us a prominent way to build compact photonic devices or circuits with non-diffraction limit. It is attributed by their extraordinary electromagnetic confining effect. But in the counterpart of lower frequencies, plasmonics behavior of metal is screened by eddy current induced in a certain skin depth. To amend this, spoof plasmons engineered by artificial structures have been introduced to mimic surface plasmons in these frequencies. But it is less useful for practical application due to their weak field confinement as manifested by large field decaying length in the upper dielectric space. Recently, a new type of engineered plasmons, domino plasmon was theoretically proposed to produce unusual field confinement and waveguiding capabilities that make them very attractive for ultra-compact device applications [Opt. Exp. 18, 754-764 (2010)]. In this work, we implemented these ideas and built three waveguiding devices based on domino plasmons. Their strong capabilities to produce versatile and ultra-compact devices with multiple electromagnetic functions have been experimentally verified in microwaves. And that can be extended to THz regime to pave the way for a new class of integrated wave circuits. © 2011 Optical Society of America

  14. Agricultural Spraying

    NASA Technical Reports Server (NTRS)

    1986-01-01

    AGDISP, a computer code written for Langley by Continuum Dynamics, Inc., aids crop dusting airplanes in targeting pesticides. The code is commercially available and can be run on a personal computer by an inexperienced operator. Called SWA+H, it is used by the Forest Service, FAA, DuPont, etc. DuPont uses the code to "test" equipment on the computer using a laser system to measure particle characteristics of various spray compounds.

  15. Experimental asymmetric plug-and-play measurement-device-independent quantum key distribution

    NASA Astrophysics Data System (ADS)

    Tang, Guang-Zhao; Sun, Shi-Hai; Xu, Feihu; Chen, Huan; Li, Chun-Yan; Liang, Lin-Mei

    2016-09-01

    Measurement-device-independent quantum key distribution (MDI-QKD) is immune to all security loopholes on detection. Previous experiments on MDI-QKD required spatially separated signal lasers and complicated stabilization systems. In this paper, we perform a proof-of-principle experimental demonstration of plug-and-play MDI-QKD over an asymmetric channel setting with a single signal laser in which the whole system is automatically stabilized in spectrum, polarization, arrival time, and phase reference. Both the signal laser and the single-photon detectors are in the possession of a common server. A passive timing-calibration technique is applied to ensure the precise and stable overlap of signal pulses. The results pave the way for the realization of a quantum network in which the users only need the encoding devices.

  16. Principle and experimental investigation of current-driven negative-inductance superconducting quantum interference device

    NASA Astrophysics Data System (ADS)

    Li, Hao; Liu, Jianshe; Zhang, Yingshan; Cai, Han; Li, Gang; Liu, Qichun; Han, Siyuan; Chen, Wei

    2017-03-01

    A negative-inductance superconducting quantum interference device (nSQUID) is an adiabatic superconducting logic device with high energy efficiency, and therefore a promising building block for large-scale low-power superconducting computing. However, the principle of the nSQUID is not that straightforward and an nSQUID driven by voltage is vulnerable to common mode noise. We investigate a single nSQUID driven by current instead of voltage, and clarify the principle of the adiabatic transition of the current-driven nSQUID between different states. The basic logic operations of the current-driven nSQUID with proper parameters are simulated by WRspice. The corresponding circuit is fabricated with a 100 A cm‑2 Nb-based lift-off process, and the experimental results at low temperature confirm the basic logic operations as a gated buffer.

  17. Experimental Challenges and Successes in Measuring Aerosol Concentrations at Prototypic Spray Conditions Encountered at the Hanford Waste Treatment and Immobilization Plant - 13327

    SciTech Connect

    Bontha, J.R.; Gauglitz, P.A.; Kurath, D.E.; Adkins, H.E.; Enderlin, C.W.; Blanchard, J.; Daniel, R.C.; Song, C.; Schonewill, P.P.; Mahoney, L.A.; Buchmiller, W.C.; Boeringa, G.; Jenks, J.

    2013-07-01

    To date, majority of the work done on measuring aerosol releases from failure of process piping was done using simple Newtonian fluids and small engineered-nozzles that do not accurately represent the fluids and breaches postulated during accident analysis at the Hanford Waste Treatment and Immobilization Plant (WTP). In addition, the majority of the work conducted in this area relies on in-spray measurements that neglect the effect of splatter and do not yield any information regarding aerosol generation rates from this additional mechanism. In order to estimate aerosol generation rates as well as reduce the uncertainties in estimating the aerosol release fractions over a broad range of breaches, fluid properties and operating conditions encountered at the WTP, the Pacific Northwest National Laboratory (PNNL) has designed, commissioned, and tested two experimental test stands. The first test stand, referred to as the large-scale test stand, was designed specifically to measure aerosol concentrations and release fractions under prototypic conditions of flow and pressure for a range of breaches postulated in the hazard analysis for 0.076 m (3-inch) process pipes. However, the size of the large-scale test stand, anticipated fluid loss during a breach, experimental risks, and costs associated with hazardous chemical simulant testing limited the large-scale test stand utility to water and a few non-hazardous physical simulants that did not fully span the particle size and rheological properties of the fluids encountered at the WTP. Overcoming these limitations and extending the range of simulants used, required designing and building a smaller test stand, which was installed and operated in a fume hood. This paper presents some of the features of both test stands, the experimental challenges encountered, and successes in measuring aerosol concentration in both test stands over a range of test conditions. (authors)

  18. Aqueous-Spray Cleaning System

    NASA Technical Reports Server (NTRS)

    Morgan, Gene E.; Hoult, William S.; Simpson, Gareth L.

    1996-01-01

    Simple aqueous-spray cleaning system with overall dimensions comparable to large kitchen refrigerator constructed for use in cleaning hardware in shop. Made of commercially available parts and materials. Incorporates economical cleaner-and-rinse-recycling subsystem, as well as programmable logic-controller device for either manual or automatic operation.

  19. Aqueous-Spray Cleaning System

    NASA Technical Reports Server (NTRS)

    Morgan, Gene E.; Hoult, William S.; Simpson, Gareth L.

    1996-01-01

    Simple aqueous-spray cleaning system with overall dimensions comparable to large kitchen refrigerator constructed for use in cleaning hardware in shop. Made of commercially available parts and materials. Incorporates economical cleaner-and-rinse-recycling subsystem, as well as programmable logic-controller device for either manual or automatic operation.

  20. Variable Gravity Effects on the Cooling Performance of a Single Phase Confined Spray

    NASA Technical Reports Server (NTRS)

    Michalak, Travis; Yerkes, Kirk; Baysinger, Karri; McQuillen, John

    2005-01-01

    The objective of this paper is to discuss the testing of a spray cooling experiment designed to be flown on NASA's KC-135 Reduced Gravity Testing Platform. Spray cooling is an example of a thermal management technique that may be utilized in high flux heat acquisition and high thermal energy transport concepts. Many researchers have investigated the utility of spray cooling for the thermal management of devices generating high heat fluxes. However, there has been little research addressing the physics and ultimate performance of spray cooling in a variable gravity environment. An experimental package, consisting of a spray chamber coupled to a fluid delivery loop system, was fabricated for variable gravity flight tests. The spray chamber contains two opposing nozzles spraying on target Indium Tin Oxide (ITO) heaters. These heaters are mounted on glass pedestals, which are part of a sump system to remove unconstrained liquid from the test chamber. Liquid is collected in the sumps and returned to the fluid delivery loop. Thermocouples mounted in and around the pedestals are used to determine both the heat loss through the underside of the IT0 heater and the heat extracted by the spray. A series of flight tests were carried out aboard the KC-135, utilizing the ability of the aircraft to produce various gravity conditions. During the flight tests, for a fixed flow rate, heat input was varied at 20, 30, 50, and 80W with variable gravities of 0.01, 0.16, 0.36, and 1.8g. Flight test data was compared to terrestrial baseline data in addition to analytical and numerical solutions to evaluate the heat transfer in the heater and support structure . There were significant differences observed in the spray cooling performance as a result of variable gravity conditions and heat inputs. In general, the Nussult number at the heater surface was found to increase with decreasing gravity conditions for heat loads greater than 30W.

  1. Experimental spray atomization studies of uni-element shear coaxial injector plate geometry for LOX/CH4 combustion and propulsion research

    NASA Astrophysics Data System (ADS)

    Dorado, Vanessa

    The Center for Space Exploration Technology Research (cSETR) has developed a set of shear coaxial injectors as part of a system-level approach to study LOX/CH4 combustion. This thesis describes the experimental studies involved in the characterization of the effects produced by two design injection face plate variables: post thickness and recession length. A testing program was developed to study the injectors' atomization process using LN2 as a substitute for LOX in cold flow and the flame anchoring mechanisms in hot firings. The cold flow testing stage was conducted to obtain liquid core measurements and compare its behavior between the different geometric configurations. Shadowgraph technique was used during this testing stage to obtain these measurements and compare them to previously published data and core length mathematical models. The inlet conditions were selected to obtain mixture ratios in the 2-4 range and a wide range of high momentum flux ratios (30-150). Particle Image Velocimetry (PIV) was also used in the testing of the three injectors to assess their atomization performance and their fragmentation behaviors. Results show that changes in central post thickness and co-annular orifice recession length with respect to the injection plate have quantifiable effects in the generated spray flow field, despite not being accounted for in traditional break up calculations. The observations and results of this investigation lead to a proof of concept demonstration in a combustion setting to support the study of flame anchoring mechanisms, also discussed in this work.

  2. Experimental and numerical investigation of a packed-bed thermal energy storage device

    NASA Astrophysics Data System (ADS)

    Yang, Bei; Wang, Yan; Bai, Fengwu; Wang, Zhifeng

    2017-06-01

    This paper presents a pilot-scale setup built to study a packed bed thermal energy storage device based on ceramic balls randomly poured into a cylindrical tank while using air as heat transfer fluid. Temperature distribution of ceramic balls throughout the packed bed is investigated both experimentally and numerically. Method of characteristic is adopted to improve the numerical computing efficiency, and mesh independence is verified to guarantee the accuracy of numerical solutions and the economy of computing time cost at the same time. Temperature in tests is as high as over 600 °C, and modeling prediction shows good agreements with experimental results under various testing conditions when heat loss is included and thermal properties of air are considered as temperature dependent.

  3. Comparison between the ASSET EZ4 NCO and Impinger Sampling Devices for Aerosol Sampling of 4,4'-Methylene Diphenyl Diisocyanate in Spray Foam Application.

    PubMed

    Puscasu, Silvia; Aubin, Simon; Cloutier, Yves; Sarazin, Philippe; Van Tra, Huu; Gagné, Sébastien

    2015-08-01

    4,4'-methylene diphenyl diisocyanate (MDI) aerosol exposure evaluation in spray foam insulation application is known to be a challenge. Current available techniques are either not user-friendly or are inaccurate or are not validated for this application. A new sampler has recently been developed to address the user-friendliness issues with other samplers: the ASSET EZ4-NCO, but the use of this sampler in spray foam insulation applications has not been demonstrated or validated. Because of this, the current work was undertaken to provide a comparison of the ASSET sampler with an impinger method, considered to be the best available method in the context of spray foam insulation, and hence the pertinence of comparing this sampler to an impinger method, considered to be the best available method for measuring MDI monomer and oligomers for this particular application. Liquid chromatography coupled with tandem mass spectrometry method for MDI monomer and oligomer analysis was implemented based on the Supelco literature. It allows the analysis of MDI-dibutylamine (DBA) and MDI 3-ring-DBA with a minimum reported value of 5ng ml(-1), a dynamic range of 5-140ng ml(-1), precision <15% and accuracy >80%. This method was used to quantify MDI aerosols collected with the ASSET sampler in an MDI spray foam environment in parallel with the toluene/MOPIP impinger reference method. The ASSET sampler significantly underestimated the levels of MDI monomer and oligomers when compared to the reference method. The estimated bias was 72% (95% confidence interval [CI] 54-89%) for the monomer and 96% (95% CI 76-115%) for the oligomers. These results demonstrate the importance of evaluating each new sampler for each isocyanate application prior to a formal worker exposure evaluation. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  4. The Captive Helicopter as a Training Device: Experimental Evaluation of a Concept. Technical Report 68-9.

    ERIC Educational Resources Information Center

    Caro, Paul W., Jr.; And Others

    As part of the Army's effort to use synthetic devices to improve training, researchers evaluated a captive helicopter attached to a ground effects machine. Experimental groups received varying amounts of pre-flight practice tasks designed to develop flight skills, while control groups received no device training. Student flight performance during…

  5. Experimental validation of a novel smart electromechanical tuned mass damper beam device

    NASA Astrophysics Data System (ADS)

    Rafique, S.; Bonello, P.; Shuttleworth, R.

    2013-09-01

    This paper validates the novel concept of utilising piezoelectric vibration energy harvesting (PVEH) beams as a tuned mass damper (TMD)—which suppresses a particular vibration mode of a generic host structure over a broad band of excitation frequencies. The proposed device comprises a pair of bimorphs shunted by a resistor, capacitor and inductor connected in various alternative circuit configurations. A benchmark for the performance is established through Den Hartog's theory for the optimal damping of a classical TMD. Experimental results demonstrate that such optimal damping is equivalently generated by the PVEH effect for appropriately tuned circuitry. These results correlate reasonably well with the results of a theoretical analysis introduced in a previous paper. The proposed TMD beam device combines the relative advantages of the classical ('mechanical') TMD and the shunted piezoelectric patch ('electrical' vibration absorber), presenting the prospect of a functionally more readily-adaptable class of 'electromechanical' tuned vibration absorbers. Moreover, with further development, this dual PVEH/TMD beam device holds the potential of simultaneous energy storage.

  6. Experimental studies on the human gait using a tethered pelvic assist device (T-PAD).

    PubMed

    Vashista, Vineet; Mustafa, S K; Agrawal, Sunil K

    2011-01-01

    This paper presents the prototype of a novel tethered pelvic assist device (T-PAD). This is a purely passive device, consisting of a set of elastic tethers with one end attached to a hip brace worn by a subject walking on a treadmill, and the other end attached to a fixed frame surrounding the subject. T-PAD offers the flexibility of varying the assistance required on the pelvis by changing the configuration of the tether attachment locations, number of tethers and tether elasticity. Experimental studies were conducted using a full and a partial pelvic constraint configuration of T-PAD, with varying tether elasticity. The studies were aimed at observing the effect of T-PAD on the human gait. Results show that T-PAD reduced the range-of-motion for the pelvic angles with increase of tether elasticity. However, it had mixed effects on the range-of-motion of the hip angles, but negligible effect on the knee and ankle joint angles. Overall, T-PAD shows potential as a low-cost pelvic support device with pelvic motion control capabilities, and can work in tandem with existing gait trainers.

  7. Design and Experimental Verification of Vibration Suppression Device on the Lift of Wheelchair-accessible Vehicles

    NASA Astrophysics Data System (ADS)

    Hatano, Yasuyoshi; Takahashi, Masaki

    2016-09-01

    In recent years, the number of wheelchair-accessible vehicles has increased with the aging of the population. Such vehicles are effective in reducing the burden on caregivers because the wheelchair user does not have to move from his/her wheelchair to a seat of the vehicle. Wheelchair-accessible vehicles are expected to be widely used in the future. However, wheelchair users have reported poor ride comfort. It is thus necessary to suppress the vibration of the vehicle considering the wheelchair user. We designed a passive damping device on the lift of wheelchair-accessible vehicles to improve the ride comfort for wheelchair users. The vibration due to road disturbances reaches the wheelchair user's body through the vehicle and wheelchair. Our control device decreases the acceleration of the torso and improves the ride comfort by ensuring that the frequency of the vibration reaching the wheelchair user differs from the resonance frequency band of the acceleration of the torso, which is the body part that feels the most discomfort. The effectiveness of the control device is verified experimentally.

  8. Experimental evaluation of dual multiple aperture devices for fluence field modulated x-ray computed tomography

    NASA Astrophysics Data System (ADS)

    Mathews, A. J.; Gang, G.; Levinson, R.; Zbijewski, W.; Kawamoto, S.; Siewerdsen, J. H.; Stayman, J. W.

    2017-03-01

    Acquisition of CT images with comparable diagnostic power can potentially be achieved with lower radiation exposure than the current standard of care through the adoption of hardware-based fluence-field modulation (e.g. dynamic bowtie filters). While modern CT scanners employ elements such as static bowtie filters and tube-current modulation, such solutions are limited in the fluence patterns that they can achieve, and thus are limited in their ability to adapt to broad classes of patient morphology. Fluence-field modulation also enables new applications such as region-of-interest imaging, task specific imaging, reducing measurement noise or improving image quality. The work presented in this paper leverages a novel fluence modulation strategy that uses "Multiple Aperture Devices" (MADs) which are, in essence, binary filters, blocking or passing x-rays on a fine scale. Utilizing two MAD devices in series provides the capability of generating a large number of fluence patterns via small relative motions between the MAD filters. We present the first experimental evaluation of fluence-field modulation using a dual-MAD system, and demonstrate the efficacy of this technique with a characterization of achievable fluence patterns and an investigation of experimental projection data.

  9. Pulsed spray structure and atomisation techniques

    NASA Astrophysics Data System (ADS)

    Yule, A. J.

    1987-08-01

    The process of atomisation from diesel injectors is found to persist for a significant proportion of the spray length before impaction on the cylinder wall. Both aerodynamic shear and cavitation appear to be of importance for the liquid jet breakdown. In addition cyclic variations are found in the atomisation and penetration of sprays. The transient nature of the spray initial conditions can cause pile up and coagulation of droplets at the leading edge of the spray pulse for certain cases. Improved modeling of diesel injection requires recognition of these phenomena and this is supported by both modeling and experimental data which have been obtained under realistic engine conditions in a specially developed rig.

  10. An Improvised "Blow Glove" Device Produces Similar PEP Values to a Commercial PEP Device: An Experimental Study.

    PubMed

    Dagan, Yaakov; Wiser, Itay; Weissman, Oren; Farber, Nimrod; Hundeshagen, Gabriel; Winkler, Eyal; Kazula-Halabi, Tamar; Haik, Josef

    2014-01-01

    Postoperative positive expiratory pressure (PEP) therapy promotes increased lung volume, secretion clearance, and improved oxygenation. Several commercial devices exist that produce recommended PEP values (10-20 cmH2O) when the patient breathes through a fixed orifice resistor. It was hypothesized that an inexpensive, improvised "blow glove" device would produce similar PEP values over a wider range of expiration volumes and flow rates. PEP for different expiration volumes (400-2000 mL) and expiratory flow rates (10-80 L/min) was compared between a commercial PEP device (Resistex, Mercury Medical, Clearwater, FL) and an improvised "blow glove" device, recorded by a Vela ventilator (CareFusion, San Diego, CA). Dynamics in positive end expiratory pressure (PEEP) values were evaluated following five consecutive expirations. The "blow glove" device was evaluated using various glove compositions and sizes. The improvised "blow glove" device produced a significantly higher rate of PEP values in the recommended range than the Resistex device (88.9% vs. 20%, p<0.0001). No significant difference was observed between small and large glove sizes (88.9% vs. 82.9%, p>0.05), but the powdered latex glove showed a significantly higher rate of PEP values in the recommended range than the powder-free latex glove (88.9% vs. 44.4%, p<0.001). A "blow glove" PEP device using a powdered latex glove produces PEP values in the recommended range over a wider spectrum of expiratory flow rates and expiration volumes than a commercial PEP device.

  11. A laser tomographic investigation of liquid fuel sprays

    NASA Technical Reports Server (NTRS)

    Yule, A. J.; Ahseng, C.; Felton, P.; Ungut, A.; Chigier, N. A.

    1980-01-01

    A light scattering technique is combined with a tomographic transformation to convert line of sight integrated data, measured in sprays, to measurements of droplet size and concentration in volume elements within the spray. The technique is developed and assessed by systematic experiments in axisymmetric sprays generated by twin-fluid atomisers. The good agreement found shows that, provided certain conditions are satisfied by the local spray structure, the technique provides information on spray structure, similar in detail and extent to that derived by photography, but with reduced experimental time. The technique is applied to an investigation of a kerosene spray vaporizing in a hot gas stream.

  12. Measurements of droplet size distribution and analysis of nasal spray atomization from different actuation pressure.

    PubMed

    Inthavong, Kiao; Fung, Man Chiu; Yang, William; Tu, Jiyuan

    2015-02-01

    To evaluate the deposition efficiency of spray droplets in a nasal cavity produced from a spray device, it is important to determine droplet size distribution, velocity, and its dispersion during atomization. Due to the limiting geometric dimensions of the nasal cavity airway, the spray plume cannot develop to its full size inside the nasal vestibule to penetrate the nasal valve region for effective drug deposition. Particle/droplet image analysis was used to determine local mean droplet sizes at eight regions within the spray plume under different actuation pressures that represent typical hand operation from pediatric to adult patients. The results showed that higher actuation pressure produces smaller droplets in the atomization. Stronger actuation pressure typical of adult users produces a longer period of the fully atomized spray stage, despite a shorter overall spray duration. This produces finer droplets when compared with the data obtained by weaker actuation pressure, typical of pediatric users. The experimental technique presented is able to capture a more complete representation of the droplet size distribution and the atomization process during an actuation. The measured droplet size distribution produced can be related to the empirically defined deposition efficiency curve of the nasal cavity, allowing a prediction of the likely deposition.

  13. Development of a new experimental device for long-duration magnetic reconnection in weakly ionized plasma

    NASA Astrophysics Data System (ADS)

    Yanai, Ryoma; Kaminou, Yasuhiro; Nishida, Kento; Inomoto, Michiaki

    2016-10-01

    Magnetic reconnection is a universal phenomenon which determines global structure and energy conversion in magnetized plasmas. Many experimental studies have been carried out to explore the physics of magnetic reconnection in fully ionized condition. However, it is predicted that the behavior of magnetic reconnection in weakly ionized plasmas such as solar chromosphere plasma will show different behavior such as ambipolar diffusion caused by interaction with neutral particles. In this research, we are developing a new experimental device to uncover the importance of ambipolar diffusion during magnetic reconnection in weakly ionized plasmas. We employ an inverter-driven rotating magnetic fields technique, which is used for generating steady azimuthal plasma current, to establish long-duration ( 1 ms) anti-parallel reconnection with magnetic field of 5 mT in weakly ionized plasma. We will present development status and initial results from the new experimental setup. This work was supported by JSPS A3 Foresight Program ``Innovative Tokamak Plasma Startup and Current Drive in Spherical Torus'', Giant-in Aid for Scientific Research (KAKENHI) 15H05750, 15K14279, 26287143 and the NIFS Collaboration Research program (NIFS14KNWP004).

  14. A randomized clinical trial in subjects with dry mouth evaluating subjective perceptions of an experimental oral gel, an oral rinse and a mouth spray compared to water.

    PubMed

    Jose, Anto; Siddiqi, Muhammad; Cronin, Matthew; DiLauro, Thomas S; Bosma, Mary Lynn

    2016-02-01

    This multicenter, randomized, parallel group study analyzed the effectiveness of an experimental oral gel, a commercially available oral rinse and a commercially available mouth spray versus water alone at relieving self-reported symptoms of dry mouth over a 28-day home use treatment period. The effects of the study treatments on dry mouth-related quality of life (QoL) were also investigated. Eligible subjects were stratified by dry mouth severity (mild, moderate or severe) and randomized to receive one of the study treatments. Prior to first use they completed a questionnaire designed to assess their baseline dry mouth-related QoL. Following first use and on Day 8 (2 hours post-treatment only) and Day 29, subjects completed the modified Product Performance and Attributes Questionnaire (PPAQ) I at 0.5, 1, 2 and 4 hours post-treatment. Subjects further assessed treatment performance using the PPAQ II questionnaire on Days 8 and 29 and the dry mouth-related QoL questionnaire on Day 29. In 396 randomized subjects almost all comparisons of responses to PPAQ I, including those for the primary endpoint (response to PPAQ I Question 1 'Relieving the discomfort of dry mouth' after 2 hours on Day 29), were statistically significant in favor of active treatment groups versus water (P < 0.05). All comparisons of responses to PPAQ II on Days 8 and 29 were statistically significant in favor of active treatments versus water (P < 0.05). Moreover, nearly all comparisons for dry mouth-related QoL scores on Day 29 were statistically significant in favor of the active treatments versus water. All the dry mouth management strategies in this trial were well tolerated.

  15. Engineering at SLAC: Designing and constructing experimental devices for the Stanford Synchrotron Radiation Lightsource - Final Paper

    SciTech Connect

    Djang, Austin

    2015-08-22

    Thanks to the versatility of the beam lines at SSRL, research there is varied and benefits multiple fields. Each experiment requires a particular set of experiment equipment, which in turns requires its own particular assembly. As such, new engineering challenges arise from each new experiment. My role as an engineering intern has been to help solve these challenges, by designing and assembling experimental devices. My first project was to design a heated sample holder, which will be used to investigate the effect of temperature on a sample's x-ray diffraction pattern. My second project was to help set up an imaging test, which involved designing a cooled grating holder and assembling multiple positioning stages. My third project was designing a 3D-printed pencil holder for the SSRL workstations.

  16. An implantable sensor device measuring suture tension dynamics: results of developmental and experimental work.

    PubMed

    Schachtrupp, A; Wetter, O; Höer, J

    2016-08-01

    Knowledge about suture tension dynamics after laparotomy closure is limited due to the lack of adequate measurement tools. As a consequence, a miniaturized implantable sensor and data logger were developed and applied experimentally in a porcine model to measure suture tension dynamics after laparotomy closure. We developed an implantable device (6 × 3 × 1 mm) fitted with silicon strain gauges and an implantable data logger allowing long-term registration. In nine domestic pigs, sensors and loggers were implanted along the suture closing a median laparotomy registering suture tension over a period of 23 h. Fascial closure was achieved by a mean suture tension of 1.07 N. After 30 minutes, suture tension was reduced to 0.81N (-24.3 %, p = 0.0003). After 12 h, tension showed a further decrease to 0.69 N (-35.5 %, n.s.), after 23 h mean suture tension reached 0.56 N, (-47.7 %, p = 0.014). The aim to develop an implantable miniaturized sensor device registering long-term suture tension dynamics was achieved. The use in the animal experiment was feasible and safe. We observed a loss of almost 50 % of suture tension 23 h after fascial closure. This could mean that up to 50 % of initial suture tension may be an unnecessary surplus not contributing to tissue stability but to the risk of suture failure.

  17. Quantum Hall resistance standard in graphene devices under relaxed experimental conditions

    NASA Astrophysics Data System (ADS)

    Schopfer, F.; Ribeiro-Palau, R.; Lafont, F.; Brun-Picard, J.; Kazazis, D.; Michon, A.; Cheynis, F.; Couturaud, O.; Consejo, C.; Jouault, B.; Poirier, W.

    Large-area and high-quality graphene devices synthesized by CVD on SiC are used to develop reliable electrical resistance standards, based on the quantum Hall effect (QHE), with state-of-the-art accuracy of 1x10-9 and under an extended range of experimental conditions of magnetic field (down to 3.5 T), temperature (up to 10 K) or current (up to 0.5 mA). These conditions are much relaxed as compared to what is required by GaAs/AlGaAs standards and will enable to broaden the use of the primary quantum electrical standards to the benefit of Science and Industry for electrical measurements. Furthermore, by comparison of these graphene devices with GaAs/AlGaAs standards, we demonstrate the universality of the QHE within an ultimate uncertainty of 8.2x10-11. This suggests the exact relation of the quantized Hall resistance with the Planck constant and the electron charge, which is crucial for the new SI to be based on fixing such fundamental constants. These results show that graphene realizes its promises and demonstrates its superiority over other materials for a demanding application. Nature Nanotech. 10, 965-971, 2015, Nature Commun. 6, 6806, 2015

  18. Simulation and experimentation of a microfluidic device based on electrowetting on dielectric.

    PubMed

    Jang, Ling-Sheng; Lin, Guo-Hua; Lin, Yi-Liang; Hsu, Chih-Yuan; Kan, Wai-Hong; Chen, Chiun-Hsun

    2007-12-01

    Electrowetting on dielectric (EWOD) moving fluid by surface tension effects offers some advantages, including simplicity of fabrication, control of minute volumes, rapid mixing, low cost and others. This work presents a numerical model using a commercial software, CFD-ACE+, and an EWOD system including a microfluidic device, a microprocessor, electric circuits, a LCD module, a keypad, a power supply and a power amplifier. The EWOD model based on a reduced form of the mass conservation and momentum equations is adopted to simulate the fluid dynamics of the droplets. The EWOD device consists of the 2 x 2 mm bottom electrodes (Au/Cr), a dielectric layer of 3,000 A nitride, 500 A Teflon and a piece of indium tin oxide (ITO)-coated glass as the top electrode. The complete EWOD phenomenon is elucidated by comparing simulation with the experimental data on droplet transportation, cutting and creation. In transportation testing, the speed of the droplet is 6 mm/s at 40 V(dc). In addition, the droplet division process takes 0.12 s at 60 V(dc) in the current case. Finally, a 347 nl droplet is successfully created from an on-chip reservoir at 60 V(dc).

  19. Modelling and experimental validation of Textile Pockets based active inflatable device.

    PubMed

    Mehmood, A; Basset, M; Orjuela, R; Dupuis, R; Drean, J Y

    2014-11-01

    This paper aims with the mathematical modelling of an active inflatable device. This device is composed of a compressor, an Electro-pneumatic Pressure Converter (EPC) and an Inflatable Textile fabric Pocket (ITP). The later has interesting mechanical properties and is fabricated using Jacquard knitting technique which allows automatic production of unlimited varieties of pattern weaving without any mould. Thanks to these features, these ITPs have provided a better alternative to the classical airbags made by stretchable polymer material. The proposed mathematical model is obtained by combining sub-models of two main parts of the whole system. In this way, a generalised and flexible model is obtained which can easily take into consideration the ITPs of different shapes. The pressure dynamics inside the ITP are considered by taking into account the air flow rate, variation of the volume of ITP and the length of pneumatic lines joining ITP with compressed air source. The parameters of the whole mathematical model are obtained via identification techniques. The effectiveness of the model is assessed through several experimental tests with the help of a servo hydraulic fatigue testing machine.

  20. Electrochemical detection of high-sensitivity CRP inside a microfluidic device by numerical and experimental studies.

    PubMed

    Lee, Gyudo; Park, Insu; Kwon, Kiwoon; Kwon, Taeyun; Seo, Jongbum; Chang, Woo-Jin; Nam, Hakhyun; Cha, Geun Sig; Choi, Moon Hee; Yoon, Dae Sung; Lee, Sang Woo

    2012-04-01

    The concentration of C-reactive protein (CRP), a classic acute phase plasma protein, increases rapidly in response to tissue infection or inflammation, especially in cases of cardiovascular disease and stroke. Thus, highly sensitive monitoring of the CRP concentration plays a pivotal role in detecting these diseases. Many researchers have studied methods for the detection of CRP concentrations such as optical, mechanical, and electrochemical techniques inside microfluidic devices. While significant progress has been made towards improving the resolution and sensitivity of detection, only a few studies have systematically analyzed the CRP concentration using both numerical and experimental approaches. Specifically, systematic analyses of the electrochemical detection of high-sensitivity CRP (hsCRP) using an enzyme-linked immunosorbant assay (ELISA) inside a microfluidic device have never been conducted. In this paper, we systematically analyzed the electrochemical detection of CRP modified through the attachment of an alkaline phosphatase (ALP-labeled CRP) using ELISA inside a chip. For this analysis, we developed a model based on antigen-antibody binding kinetics theory for the numerical quantification of the CRP concentration. We also experimentally measured the current value corresponding to the ALP-labeled CRP concentration inside the microfluidic chip. The measured value closely matched the calculated value obtained by numerical simulation using the developed model. Through this comparison, we validated the numerical simulation methods, and the calculated and measured values. Lastly, we examined the effects of various microfluidic parameters on electrochemical detection of the ALP-labeled CRP concentration using numerical simulations. The results of these simulations provide insight into the microfluidic electrochemical reactions used for protein detection. Furthermore, the results described in this study should be useful for the design and optimization of

  1. A fast and low-cost spray method for prototyping and depositing surface-enhanced Raman scattering arrays on microfluidic paper based device.

    PubMed

    Li, Bowei; Zhang, Wei; Chen, Lingxin; Lin, Bingcheng

    2013-08-01

    In this study, a fast, low-cost, and facile spray method was proposed. This method deposits highly sensitive surface-enhanced Raman scattering (SERS) silver nanoparticles (AgNPs) on the paper-microfluidic scheme. The procedures for substrate preparation were studied including different strategies to synthesize AgNPs and the optimization of spray cycles. In addition, the morphologies of the different kinds of paper substrates were characterized by SEM and investigated by their SERS signals. The established method was found to be favorable for obtaining good sensitivity and reproducible results. The RSDs of Raman intensity of randomly analyzing 20 spots on the same paper or different filter papers depositing AgNPs are both below 15%. The SERS enhancement factor is approximately 2 × 10(7) . The whole fabrication is very rapid, robust, and does not require specific instruments. Furthermore, the total cost for 1000 pieces of chip is less than $20. These advantages demonstrated the potential for growing SERS applications in the area of environmental monitoring, food safety, and bioanalysis in the future. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Foliar spray banding characteristics

    Treesearch

    A.R. Womac; C.W. Smith; Joseph E. Mulrooney

    2004-01-01

    Foliar spray banding was explored as a means of reducing peticide use compared to broadcast applications. Barious geometric spray patterns and delivery angles of foliar spray bands were investigated to increase spray deposits in a crop row at a constant spray rate of 94 L/ha. Wind-free laboratory results indicated that a banded application using three 65° hollow-cone...

  3. Microgravity experiments and numerical studies on ethanol/air spray flames

    NASA Astrophysics Data System (ADS)

    Thimothée, Romain; Chauveau, Christian; Halter, Fabien; Nicoli, Colette; Haldenwang, Pierre; Denet, Bruno

    2017-01-01

    Spray flames are known to exhibit amazing features in comparison with single-phase flames. The weightless situation offers the conditions in which the spray characteristics can be well controlled before and during combustion. The article reports on a joint experimental/numerical work that concerns ethanol/air spray flames observed in a spherical chamber using the condensation technique of expansion cooling (based on the Wilson cloud chamber principle), under microgravity. We describe the experimental set-up and give details on the creation of a homogeneous and nearly monosized aerosol. Different optical diagnostics are employed successfully to measure the relevant parameters of two-phase combustion. A classical shadowgraphy system is used to track the flame speed propagation and allow us to observe the flame front instability. The complete characterization of the aerosol is performed with a laser diffraction particle size analyser by measuring the droplet diameter and the droplet density number, just before ignition. A laser tomography device allows us to measure the temporal evolution of the droplet displacement during flame propagation, as well as to identify the presence of droplets in the burnt gases. The numerical modelling is briefly recalled. In particular, spray-flame propagation is schematized by the combustion spread in a 2-D lattice of fuel droplets surrounded by an initial gaseous mixture of fuel vapour and air. In its spherical expansion, the spray flame presents a corrugated front pattern, while the equivalent single-phase flame does not. From a numerical point of view, the same phenomena of wrinkles are also observed in the simulations. The front pattern pointed out by the numerical approach is identified as of Darrieus-Landau (DL) type. The droplets are found to trigger the instability. Then, we quantitatively compare experimental data with numerical predictions on spray-flame speed. The experimental results show that the spray-flame speed is of the

  4. Laser Doppler velocimeter aerial spray measurements

    NASA Technical Reports Server (NTRS)

    Zalay, A. D.; Eberle, W. R.; Howle, R. E.; Shrider, K. R.

    1978-01-01

    An experimental research program for measuring the location, spatial extent, and relative concentration of airborne spray clouds generated by agricultural aircraft is described. The measurements were conducted with a ground-based laser Doppler velocimeter. The remote sensing instrumentation, experimental tests, and the results of the flight tests are discussed. The cross section of the aerial spray cloud and the observed location, extent, and relative concentration of the airborne particulates are presented. It is feasible to use a mobile laser Doppler velocimeter to track and monitor the transport and dispersion of aerial spray generated by an agricultural aircraft.

  5. Experimental investigation of vapor shielding effects induced by ELM-like pulsed plasma loads using the double plasma gun device

    NASA Astrophysics Data System (ADS)

    Sakuma, I.; Kikuchi, Y.; Kitagawa, Y.; Asai, Y.; Onishi, K.; Fukumoto, N.; Nagata, M.

    2015-08-01

    We have developed a unique experimental device of so-called double plasma gun, which consists of two magnetized coaxial plasma gun (MCPG) devices, in order to clarify effects of vapor shielding on material erosion due to transient events in magnetically confined fusion devices. Two ELM-like pulsed plasmas produced by the two MCPG devices were injected into a target chamber with a variable time difference. For generating ablated plasmas in front of a target material, an aluminum foil sample in the target chamber was exposed to a pulsed plasma produced by the 1st MCPG device. The 2nd pulsed plasma was produced with a time delay of 70 μs. It was found that a surface absorbed energy measured by a calorimeter was reduced to ∼66% of that without the Al foil sample. Thus, the reduction of the incoming plasma energy by the vapor shielding effect was successfully demonstrated in the present experiment.

  6. Experimental study of proton rate density in a spherical inertial electrostatic confinement fusion device

    NASA Astrophysics Data System (ADS)

    Gu, Yibin

    The concept of spherical inertial-electrostatic confinement (SIEC) is to focus and accelerate ions and electrons radially inward into the center of a negatively biased, highly transparent spherical grid to create a space-charge double-potential well (a negative-potential well nested inside a positive-potential well) which confines the high-energy ions in the dense central core region such that appreciable nuclear fusion reactions are obtained. This experimental work has focused on creating the double-potential well at high perveance (I/V3/2) where there is a significant charge build-up in the center, and on proving the existence of the well from its characteristic radial proton rate density profile. Based on the spatial measurement of the D-D fusion protons by using a capillary proton collimator and the unfolding of this data, this work has been directed to evaluate the radial proton rate density profiles to explore the evolution of potential-well structure in the current and voltage (perveance) range where the double well is expected. Under the optimized operating conditions admitted by using the Star mode to improve focusing to 1.6× ballistic limit and double-grid setup to reduce the ion radial energy spread to <10%, the experiment has successfully created and, through identification of a distinct two-peak proton rate density profile, demonstrated the existence of the double- potential well. Experimental measurements of the two-peak proton rate density profiles have uniquely shown the emergence of the double potential well for perveances >0.34 mA/kV3/2. As the perveance increases, the feature of the double well becomes prominent. At 1.38 mA/kV3/2 (80 mA and 15 kV), the maximum negative potential well depth obtained from the measured proton rate density was calculated, using a beam-background fusion and charge-exchange model, to be ~22-27% of the applied voltage. Also, during the progress of this dissertation, two valuable SIEC derivatives-an SIEC wavelength

  7. Combining indoor residual spraying with chlorfenapyr and long-lasting insecticidal bed nets for improved control of pyrethroid-resistant Anopheles gambiae: an experimental hut trial in Benin

    PubMed Central

    2011-01-01

    Background Neither indoor residual spraying (IRS) nor long-lasting insecticidal nets (LLINs) are able to fully interrupt transmission in holoendemic Africa as single interventions. The combining of IRS and LLINs presents an opportunity for improved control and management of pyrethroid resistance through the simultaneous presentation of unrelated insecticides. Method Chlorfenapyr IRS and a pyrethroid-impregnated polyester LLIN (WHO approved) were tested separately and together in experimental huts in southern Benin against pyrethroid resistant Anopheles gambiae and Culex quinquefasciatus. The bed nets were deliberately holed with either six or 80 holes to examine the effect of increasing wear and tear on protectiveness. Anopheles gambiae were genotyped for the kdr gene to assess the combination's potential to prevent the selection of pyrethroid resistance. Results The frequency of kdr was 84%. The overall mortality rates of An. gambiae were 37% and 49% with the six-hole and 80-hole LLINs, respectively, and reached 57% with chlorfenapyr IRS. Overall mortality rates were significantly higher with the combination treatments (82-83%) than with the LLIN or IRS individual treatments. Blood feeding (mosquito biting) rates were lowest with the 6-hole LLIN (12%), intermediate with the 80-hole LLIN (32%) and highest with untreated nets (56% with the 6-hole and 54% with the 80-hole nets). Blood feeding (biting) rates and repellency of mosquitoes with the combination of LLIN and chlorfenapyr IRS showed significant improvement compared to the IRS treatment but did not differ from the LLIN treatments indicating that the LLINs were the primary agents of personal protection. The combination killed significantly higher proportions of Cx. quinquefasciatus (51%, 41%) than the LLIN (15%, 13%) or IRS (32%) treatments. Conclusion The chlorfenapyr IRS component was largely responsible for controlling pyrethroid-resistant mosquitoes and the LLIN component was largely responsible for blood

  8. Combining indoor residual spraying with chlorfenapyr and long-lasting insecticidal bed nets for improved control of pyrethroid-resistant Anopheles gambiae: an experimental hut trial in Benin.

    PubMed

    Ngufor, Corine; N'Guessan, Raphael; Boko, Pelagie; Odjo, Abibatou; Vigninou, Estelle; Asidi, Alex; Akogbeto, Martin; Rowland, Mark

    2011-11-16

    Neither indoor residual spraying (IRS) nor long-lasting insecticidal nets (LLINs) are able to fully interrupt transmission in holoendemic Africa as single interventions. The combining of IRS and LLINs presents an opportunity for improved control and management of pyrethroid resistance through the simultaneous presentation of unrelated insecticides. Chlorfenapyr IRS and a pyrethroid-impregnated polyester LLIN (WHO approved) were tested separately and together in experimental huts in southern Benin against pyrethroid resistant Anopheles gambiae and Culex quinquefasciatus. The bed nets were deliberately holed with either six or 80 holes to examine the effect of increasing wear and tear on protectiveness. Anopheles gambiae were genotyped for the kdr gene to assess the combination's potential to prevent the selection of pyrethroid resistance. The frequency of kdr was 84%. The overall mortality rates of An. gambiae were 37% and 49% with the six-hole and 80-hole LLINs, respectively, and reached 57% with chlorfenapyr IRS. Overall mortality rates were significantly higher with the combination treatments (82-83%) than with the LLIN or IRS individual treatments. Blood feeding (mosquito biting) rates were lowest with the 6-hole LLIN (12%), intermediate with the 80-hole LLIN (32%) and highest with untreated nets (56% with the 6-hole and 54% with the 80-hole nets). Blood feeding (biting) rates and repellency of mosquitoes with the combination of LLIN and chlorfenapyr IRS showed significant improvement compared to the IRS treatment but did not differ from the LLIN treatments indicating that the LLINs were the primary agents of personal protection. The combination killed significantly higher proportions of Cx. quinquefasciatus (51%, 41%) than the LLIN (15%, 13%) or IRS (32%) treatments. The chlorfenapyr IRS component was largely responsible for controlling pyrethroid-resistant mosquitoes and the LLIN component was largely responsible for blood feeding inhibition and personal

  9. Development and experimental study of oil-free capacitor module for plasma focus device

    NASA Astrophysics Data System (ADS)

    Sharma, Ravindra Kumar; Sharma, Archana

    2017-03-01

    This development is concerned with the compact capacitor module for a plasma focus device. Oil-free, non-standard geometry capacitors are designed and developed for high current delivery in sub-microseconds time. Metalized dielectric film based pulse capacitor becomes progressively less viable at currents above 10 kA. It is due to reliability and energy scaling difficulties, based on effects such as vaporization, high resistivity, and end connection. Bipolar electrolytic capacitors are also not preferred due to their limited life and comparatively low peak current delivery. Bi-axially oriented polypropylene (BOPP) film with extended aluminum foil is a combination to deliver moderately high power. But, electrically weak points, relative permittivity, and the edge gap margins have made its adoption difficult. A concept has been developed in lab for implementing the above combination in a less complex and costly manner. This paper concerns the development and testing process techniques for quite different hollow cylindrical, oil-free capacitors (4 μ F , 10 kV, 20 nH). Shot life of 1000 has been experimentally performed on the test bed at its rated energy density level. The technological methods and engineering techniques are now available and utilized for manufacturing and testing of BOPP film based oil-free capacitors.

  10. Experimental approaches to assessing the impact of a cesium chloride radiological dispersal device

    USGS Publications Warehouse

    Lee, S.; Gibb, Snyder E.; Barzyk, J.; McGee, J.; Koenig, A.

    2008-01-01

    The US EPA, as a part of the Chemical, Biological, Radiological-Nuclear, and Explosives (CBRNE) Research and Technology Initiative (CRTI) project team, is currently working to assess the impacts of an urban radiological dispersion device (RDD) and to develop containment and decontamination strategies. Three efforts in this area are currently underway: development of a laboratory-scale cesium chloride deposition method to mimic a RDD; assessment of cesium (Cs) penetration depth and pathways in urban materials using two dimensional (2-D) mapping laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS); and experimental determination of distribution coefficients (kd) for Cs in water-building material systems. It is critical that, when performing laboratory-scale experiments to assess the fate of Cs from an RDD, the Cs particle deposition method mimics the RDD deposition. Once Cs particles are deposited onto urban surfaces, 2-D mapping of Cs concentrations using LA-ICP-MS is a critical tool for determining Cs transport pathways through these materials. Lastly, distribution coefficients are critical for understanding the transport of Cs in urban settings when direct measurements of its penetration depth are unavailable. An assessment of the newly developed deposition method along with preliminary results from the penetration experiments are presented in this paper.

  11. Formation of annular plasma downstream by magnetic aperture in the helicon experimental device

    NASA Astrophysics Data System (ADS)

    Ghosh, Soumen; Yadav, S.; Barada, K. K.; Chattopadhyay, P. K.; Ghosh, J.; Pal, R.; Bora, D.

    2017-02-01

    In the Helicon eXperimental (HeX) device, the geometric aperture is fixed, but the position of the magnetic aperture can be varied. Working with Argon gas in the pressure range of 1 - 10 × 10 - 4 mbar, an annular plasma (density ˜ 10 16 m - 3 ) is formed downstream, always in front of the magnetic aperture. This occurs irrespective of the relative position of the geometric aperture or the presence of a radial electric field. This is in contrary to the earlier proposition made by others that a radial electric field is necessary to produce a hollow plasma profile. Instead, the ionization of neutrals in the radially outer region by the tail electrons, rotating fast due to gradient-B drift in the azimuthal direction, seems to account for the observed off-axis density peaking in the present experiment. This also explains the variation of the plasma annulus diameter seen here by changing the input radio frequency power ( 100 - 800 W ) .

  12. Non-Markov effects in intersecting sprays

    NASA Astrophysics Data System (ADS)

    Panchagnula, Mahesh; Kumaran, Dhivyaraja; Deevi, Sri Vallabha; Tangirala, Arun

    2016-11-01

    Sprays have been assumed to follow a Markov process. In this study, we revisit that assumption relying on experimental data from intersecting and non-intersecting sprays. A phase Doppler Particle Analyzer (PDPA) is used to measure particle diameter and velocity at various axial locations in the intersection region of two sprays. Measurements of single sprays, with one nozzle turned off alternatively are also obtained at the same locations. This data, treated as an unstructured time series is classified into three bins each for diameter (small, medium, large) and velocity (slow, medium, fast). Conditional probability analysis on this binned data showed a higher static correlation between droplet velocities, while diameter correlation is significantly alleviated (reduced) in intersecting sprays, compared to single sprays. Further analysis using serial correlation measures: auto-correlation function (ACF) and partial auto-correlation function (PACF) shows that the lagged correlations in droplet velocity are enhanced while those in the droplet diameter are significantly debilitated in intersecting sprays. We show that sprays are not necessarily Markov processes and that memory persists, even though curtailed to fewer lags in case of size, and enhanced in case of droplet velocity.

  13. Influence of deposition and spray pattern of nasal powders on insulin bioavailability.

    PubMed

    Pringels, E; Callens, C; Vervaet, C; Dumont, F; Slegers, G; Foreman, P; Remon, J P

    2006-03-09

    The influence of the deposition pattern and spray characteristics of nasal powder formulations on the insulin bioavailability was investigated in rabbits. The formulations were prepared by freeze drying a dispersion containing a physical mixture of drum dried waxy maize starch (DDWM)/Carbopol 974P (90/10, w/w) or a spray-dried mixture of Amioca starch/Carbopol 974P (25/75, w/w). The deposition in the nasal cavity of rabbits and in a silicone human nose model after actuation of three nasal delivery devices (Monopowder, Pfeiffer and experimental system) was compared and related to the insulin bioavailability. Posterior deposition of the powder formulation in the nasal cavity lowered the insulin bioavailability. To study the spray pattern, the shape and cross-section of the emitted powder cloud were analysed. It was concluded that the powder bulk density of the formulation influenced the spray pattern. Consequently, powders of different bulk density were prepared by changing the solid fraction of the freeze dried dispersion and by changing the freezing rate during freeze drying. After nasal delivery of these powder formulations no influence of the powder bulk density and of the spray pattern on the insulin bioavailability was observed.

  14. High mass throughput particle generation using multiple nozzle spraying

    DOEpatents

    Pui, David Y. H.; Chen, Da-Ren

    2015-06-09

    Spraying apparatus and methods that employ multiple nozzle structures for producing multiple sprays of particles, e.g., nanoparticles, for various applications, e.g., pharmaceuticals, are provided. For example, an electrospray dispensing device may include a plurality of nozzle structures, wherein each nozzle structure is separated from adjacent nozzle structures by an internozzle distance. Sprays of particles are established from the nozzle structures by creating a nonuniform electrical field between the nozzle structures and an electrode electrically isolated therefrom.

  15. High mass throughput particle generation using multiple nozzle spraying

    DOEpatents

    Pui, David Y.H.; Chen, Da-Ren

    2004-07-20

    Spraying apparatus and methods that employ multiple nozzle structures for producing multiple sprays of particles, e.g., nanoparticles, for various applications, e.g., pharmaceuticals, are provided. For example, an electrospray dispensing device may include a plurality of nozzle structures, wherein each nozzle structure is separated from adjacent nozzle structures by an internozzle distance. Sprays of particles are established from the nozzle structures by creating a nonuniform electrical field between the nozzle structures and an electrode electrically isolated therefrom.

  16. High mass throughput particle generation using multiple nozzle spraying

    DOEpatents

    Pui, David Y. H.; Chen, Da-Ren

    2009-03-03

    Spraying apparatus and methods that employ multiple nozzle structures for producing multiple sprays of particles, e.g., nanoparticles, for various applications, e.g., pharmaceuticals, are provided. For example, an electrospray dispensing device may include a plurality of nozzle structures, wherein each nozzle structure is separated from adjacent nozzle structures by an internozzle distance. Sprays of particles are established from the nozzle structures by creating a nonuniform electrical field between the nozzle structures and an electrode electrically isolated therefrom.

  17. Hair spray poisoning

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/002705.htm Hair spray poisoning To use the sharing features on this page, please enable JavaScript. Hair spray poisoning occurs when someone breathes in (inhales) ...

  18. Triamcinolone Nasal Spray

    MedlinePlus

    ... itchy nose and itchy, watery eyes caused by hay fever or other allergies. Triamcinolone nasal spray should not ... germs.Triamcinolone nasal spray controls the symptoms of hay fever and allergies but does not cure these conditions. ...

  19. Mechanisms of Smoke Reduction in the High-Pressure Combustion of Emulsified Fuels. Volume 3. Experimental Measurements and Computer Modeling of Evaporating Emulsified and Neat Fuel Sprays.

    DTIC Science & Technology

    1984-05-01

    20 9. COMPARISON OF SMD ON CENTERLINE AND EDGE OF SPRAY ....... 24 . 10. COMPARISON OF ROSIN - RAMMLER N PARAMETER...of two parameters defining a Rosin - Rammler , log-normal, or normal distribution, or as a histogram of 15 size . classes of drops without any assumption...about the shape of the distribution. Although .- all of the distributions have been tried, the Rosin - Rammler has generally provided the best fit and

  20. Azelastine Nasal Spray

    MedlinePlus

    ... and replace with the pump unit. Prime the delivery system (pump unit) with four sprays or until a fine mist appears. If 3 days or more have elapsed since your last use of the nasal spray, reprime the pump with two sprays or until a fine mist appears.

  1. Remotely controlled spray gun

    NASA Technical Reports Server (NTRS)

    Cunningham, William C. (Inventor)

    1987-01-01

    A remotely controlled spray gun is described in which a nozzle and orifice plate are held in precise axial alignment by an alignment member, which in turn is held in alignment with the general outlet of the spray gun by insert. By this arrangement, the precise repeatability of spray patterns is insured.

  2. Fluid force predictions and experimental measurements for a magnetically levitated pediatric ventricular assist device.

    PubMed

    Throckmorton, Amy L; Untaroiu, Alexandrina; Lim, D Scott; Wood, Houston G; Allaire, Paul E

    2007-05-01

    The latest generation of artificial blood pumps incorporates the use of magnetic bearings to levitate the rotating component of the pump, the impeller. A magnetic suspension prevents the rotating impeller from contacting the internal surfaces of the pump and reduces regions of stagnant and high shear flow that surround fluid or mechanical bearings. Applying this third-generation technology, the Virginia Artificial Heart Institute has developed a ventricular assist device (VAD) to support infants and children. In consideration of the suspension design, the axial and radial fluid forces exerted on the rotor of the pediatric VAD were estimated using computational fluid dynamics (CFD) such that fluid perturbations would be counterbalanced. In addition, a prototype was built for experimental measurements of the axial fluid forces and estimations of the radial fluid forces during operation using a blood analog mixture. The axial fluid forces for a centered impeller position were found to range from 0.5 +/- 0.01 to 1 +/- 0.02 N in magnitude for 0.5 +/- 0.095 to 3.5 +/- 0.164 Lpm over rotational speeds of 6110 +/- 0.39 to 8030 +/- 0.57% rpm. The CFD predictions for the axial forces deviated from the experimental data by approximately 8.5% with a maximum difference of 18% at higher flow rates. Similarly for the off-centered impeller conditions, the maximum radial fluid force along the y-axis was found to be -0.57 +/- 0.17 N. The maximum cross-coupling force in the x direction was found to be larger with a maximum value of 0.74 +/- 0.22 N. This resulted in a 25-35% overestimate of the radial fluid force as compared to the CFD predictions; this overestimation will lead to a far more robust magnetic suspension design. The axial and radial forces estimated from the computational results are well within a range over which a compact magnetic suspension can compensate for flow perturbations. This study also serves as an effective and novel design methodology for blood pump

  3. Experimental verification and optimization of a linear electromagnetic energy harvesting device

    NASA Astrophysics Data System (ADS)

    Mullen, Christopher; Lee, Soobum

    2017-04-01

    Implementation of energy harvesting technology can provide a sustainable, remote power source for soldiers by reducing the battery weight and allowing them to stay in the field for longer periods of time. Among multiple energy conversion principles, electromagnetic induction can scavenge energy from wasted kinematic and vibration energy found from human motion. Hip displacement during human gait acts as a base excitation for an energy harvesting backpack system. The placement of a permanent magnet in this vibration environment results in relative motion of the magnet to the coil of copper wire, which induces an electric current. This current can be saved to a battery or capacitor bank installed on the backpack to be used to power electronic devices. The purpose of this research is to construct a reliable simulation model for an electromagnetic vibration energy harvester and use it for a multi-variable optimization algorithm to identify an optimal coil and magnet layout for highest power output. Key components of the coupled equations of motion such as the magnetic flux density and coil inductance are obtained using ANSYS multi-physics software or by measuring them. These components are fed into a harvester simulation model (e.g. coupled field equations of motion for the backpack harvester) that generates the electrical power output. The developed simulation model is verified with a case study including an experimental test. Then the optimal design parameters in the simulation model (e.g., magnet layout, coil width, outer coil diameter, external load resistance) are identified for maximum power. Results from this study will pave the way for a more efficient energy harvesting backpack while providing better insight into the efficiency of magnet and coil layout for electromagnetic applications.

  4. Integrated computational study of ultra-high heat flux cooling using cryogenic micro-solid nitrogen spray

    NASA Astrophysics Data System (ADS)

    Ishimoto, Jun; Oh, U.; Tan, Daisuke

    2012-10-01

    A new type of ultra-high heat flux cooling system using the atomized spray of cryogenic micro-solid nitrogen (SN2) particles produced by a superadiabatic two-fluid nozzle was developed and numerically investigated for application to next generation super computer processor thermal management. The fundamental characteristics of heat transfer and cooling performance of micro-solid nitrogen particulate spray impinging on a heated substrate were numerically investigated and experimentally measured by a new type of integrated computational-experimental technique. The employed Computational Fluid Dynamics (CFD) analysis based on the Euler-Lagrange model is focused on the cryogenic spray behavior of atomized particulate micro-solid nitrogen and also on its ultra-high heat flux cooling characteristics. Based on the numerically predicted performance, a new type of cryogenic spray cooling technique for application to a ultra-high heat power density device was developed. In the present integrated computation, it is clarified that the cryogenic micro-solid spray cooling characteristics are affected by several factors of the heat transfer process of micro-solid spray which impinges on heated surface as well as by atomization behavior of micro-solid particles. When micro-SN2 spraying cooling was used, an ultra-high cooling heat flux level was achieved during operation, a better cooling performance than that with liquid nitrogen (LN2) spray cooling. As micro-SN2 cooling has the advantage of direct latent heat transport which avoids the film boiling state, the ultra-short time scale heat transfer in a thin boundary layer is more possible than in LN2 spray. The present numerical prediction of the micro-SN2 spray cooling heat flux profile can reasonably reproduce the measurement results of cooling wall heat flux profiles. The application of micro-solid spray as a refrigerant for next generation computer processors is anticipated, and its ultra-high heat flux technology is expected

  5. Method of producing thermally sprayed metallic coating

    DOEpatents

    Byrnes, Larry Edward; Kramer, Martin Stephen; Neiser, Richard A.

    2003-08-26

    The cylinder walls of light metal engine blocks are thermally spray coated with a ferrous-based coating using an HVOF device. A ferrous-based wire is fed to the HVOF device to locate a tip end of the wire in a high temperature zone of the device. Jet flows of oxygen and gaseous fuel are fed to the high temperature zone and are combusted to generate heat to melt the tip end. The oxygen is oversupplied in relation to the gaseous fuel. The excess oxygen reacts with and burns a fraction of the ferrous-based feed wire in an exothermic reaction to generate substantial supplemental heat to the HVOF device. The molten/combusted metal is sprayed by the device onto the walls of the cylinder by the jet flow of gases.

  6. Laser modification of thermally sprayed coatings

    NASA Astrophysics Data System (ADS)

    Uglov, A. A.; Fomin, A. D.; Naumkin, A. O.; Pekshev, P. Iu.; Smurov, I. Iu.

    1987-08-01

    Experimental results are reported on the modification of thermally sprayed coatings on steels and aluminum alloys using pulsed YAG and CW CO2 lasers. In particular, results obtained for self-fluxing Ni9CrBSi powders, ZRO2 ceramic, and titanium are examined. It is shown that the laser treatment of thermally sprayed coatings significantly improves their physicomechanical properties; it also makes it possible to obtain refractory coatings on low-melting substrates with good coating-substrate adhesion.

  7. Experimental investigation of a new device to control the asymmetric flowfield on forebodies at large angles of attack

    NASA Technical Reports Server (NTRS)

    Moskovitz, Cary A.; Hall, Robert M.; Dejarnette, F. R.

    1990-01-01

    An exploratory experimental investigation of a new device to control the asymmetric flowfield on forebodies at large angles of attack has been conducted. The device is a rotatable forebody tip, which varies in cross section from circular at its base to elliptic at its tip. The device itself extends over a small portion of the aircraft or missile forebody. The device provides two important improvements. First, it replaced the normally random behavior of the nose side force as a function of nose tip orientation with a predictable and generally sinusoidal distribution and, second, the device showed promise for use as part of a vehicle control system, to be deflected in a prescribed manner to provide additional directional control for the vehicle. The device was tested on a cone/cylinder model having a 10 deg semiapex angle and on a 3.0 caliber tangent ogive model, each with a base diameter of 3.5 in, for angles of attack from 30 to 60 deg. Data were taken from 3 circumferential rows of pressure taps on each model at a Reynolds number of 84,000 based on cylinder diameter and by a helium-bubble flow visualization technique at a Reynolds number of 24,000.

  8. Investigation on the Clogging Behavior and Additional Wall Cooling for the Axial-Injection Cold Spray Nozzle

    NASA Astrophysics Data System (ADS)

    Wang, Xudong; Zhang, Bo; Lv, Jinsheng; Yin, Shuo

    2015-04-01

    During the cold spray process, nozzle clogging always happens when spraying low-melting point materials, e.g., aluminum, significantly decreasing the working efficiency. In this paper, a comprehensive investigation was carried out to clarify the reason for inducing nozzle clogging and then to evaluate a home-made nozzle cooling device for preventing nozzle clogging. Computational fluid dynamics technique was employed as the main method with some necessary experiment validation. It is found that the particle dispersion and the high-temperature nozzle wall at the near-throat region are two dominant factors that cause nozzle clogging. The numerical results also reveal that the home-made cooling device can significantly reduce the nozzle wall temperature, which was validated by the experimental measurement. Besides, the aluminum coating build-up experiment further indicates that the additional cooling device can truly prevent the nozzle clogging.

  9. Experimental test of MR fluid based tactile device for minimally invasive surgery

    NASA Astrophysics Data System (ADS)

    Oh, Jong-Seok; Kim, Jin-Kyu; Choi, Seung-Bok

    2013-04-01

    Recently, it is very popular in modern medical industry to adopt robotic technology such as robotic minimally invasive surgery (RMIS). Compared with open surgery, the RMIS needs the robot to perform surgery through the usage of long surgical instruments that are inserted through incision points. This causes the surgeon not to feel viscosity and stiffness of the tissue or organ. So, for the tactile recognition of human organ in RMIS, this work proposes a novel tactile device that incorporates with magnetorheological (MR) fluid. The MR fluid is fully contained by diaphragm and several pins. By applying different magnetic field, the operator can feel different force from the proposed tactile device. In order to generate required force from the device, the repulsive force of human body is firstly measured as reference data and an appropriate size of tactile device is designed. Pins attached with the diaphragm are controlled by shape-memory-alloy (SMA). Thus, the proposed tactile device can realize repulsive force and shape of organ. It has been demonstrated via experiment whether the measured force can be achieved by applying proper control input current. In addition, psychophysical experiments are conducted to evaluate performance on the tactile rendering of the proposed tactile device. From these results, the practical feasibility of the tactile device is verified.

  10. Experimental study of delta wing leading-edge devices for drag reduction at high lift

    NASA Technical Reports Server (NTRS)

    Johnson, T. D., Jr.; Rao, D. M.

    1982-01-01

    The drag reduction devices selected for evaluation were the fence, slot, pylon-type vortex generator, and sharp leading-edge extension. These devices were tested on a 60 degree flatplate delta (with blunt leading edges) in the Langley Research Center 7- by 10-foot high-speed tunnel at low speed and to angles of attack of 28 degrees. Balance and static pressure measurements were taken. The results indicate that all the devices had significant drag reduction capability and improved longitudinal stability while a slight loss of lift and increased cruise drag occurred.

  11. Analysis and experimental study on the effect of a resonant tube on the performance of acoustic levitation devices

    NASA Astrophysics Data System (ADS)

    Jiang, Hai; Liu, Jianfang; Lv, Qingqing; Gu, Shoudong; Jiao, Xiaoyang; Li, Minjiao; Zhang, Shasha

    2016-09-01

    The influence of a resonant tube on the performance of acoustic standing wave-based levitation device (acoustic levitation device hereinafter) is studied by analyzing the acoustic pressure and levitation force of four types of acoustic levitation devices without a resonance tube and with resonance tubes of different radii R using ANSYS and MATLAB. Introducing a resonance tube either enhances or weakens the levitation strength of acoustic levitation device, depending on the resonance tube radii. Specifically, the levitation force is improved to a maximum degree when the resonance tube radius is slightly larger than the size of the reflector end face. Furthermore, the stability of acoustic levitation device is improved to a maximum degree by introducing a resonance tube of R=1.023λ. The experimental platform and levitation force measurement system of the acoustic levitation device with concave-end-face-type emitter and reflector are developed, and the test of suspended matters and liquid drops is conducted. Results show that the Φ6.5-mm steel ball is suspended easily when the resonance tube radius is 1.023λ, and the Φ5.5-mm steel ball cannot be suspended when the resonance tube radius is 1.251λ. The levitation capability of the original acoustic levitation device without a resonance tube is weakened when a resonance tube of R=1.251λ is applied. These results are consistent with the ANSYS simulation results. The levitation time of the liquid droplet with a resonance tube of R=1.023λ is longer than without a resonance tube. This result is also supported by the MATLAB simulation results. Therefore, the performance of acoustic levitation device can be improved by introducing a resonant tube with an appropriate radius.

  12. Multiple applicator hepatic ablation with interstitial ultrasound devices: Theoretical and experimental investigation

    PubMed Central

    Prakash, Punit; Salgaonkar, Vasant A.; Clif Burdette, E.; Diederich, Chris J.

    2012-01-01

    Purpose: To evaluate multiple applicator implant configurations of interstitial ultrasound devices for large volume ablation of liver tumors. Methods: A 3D bioacoustic-thermal model using the finite element method was implemented to assess multiple applicator implant configurations for thermal ablation with interstitial ultrasound energy. Interstitial applicators consist of linear arrays of up to four 10 mm-long tubular ultrasound transducers, each under separate and dynamic power control, enclosed within a water-cooled delivery catheter (2.4 mm OD). The authors considered parallel implants with two and three applicators (clustered configuration), spaced 2–3 cm apart, to simulate open surgical placement. In addition, the authors considered two applicator implants with applicators converging and diverging at angles of ∼20°, 30°, and 45° to simulate percutaneous placement. Heating experiments (10–15 min) were performed and compared against simulations employing the same experimental parameters. To estimate the performance of parallel, multiple applicator configurations in an in vivo setting, simulations were performed taking into account a range of blood perfusion levels (0, 5, 12, and 15 kg m−3 s−1) that may occur in tumors of varying vascularity. The impact of tailoring the power supplied to individual transducer elements along the length of applicators is explored for applicators inserted in non-parallel (converging and diverging) configurations. Thermal dose (t43 > 240 min) and temperature thresholds (T > 52 °C) were used to define the ablation zones, with dynamic changes to tissue acoustic and thermal properties incorporated within the model. Results: Experiments in ex vivo bovine liver yielded ablation zones ranging between 4.0–5.6 cm × 3.2–4.9 cm, in cross section. Ablation zone dimensions predicted by simulations with similar parameters to the experiments were in close agreement (within 5 mm). Simulations of in vivo heating showed that 15

  13. Hemolysis in a laminar flow-through Couette shearing device: an experimental study.

    PubMed

    Boehning, Fiete; Mejia, Tzahiry; Schmitz-Rode, Thomas; Steinseifer, Ulrich

    2014-09-01

    Reducing hemolysis has been one of the major goals of rotary blood pump development and in the investigational phase, the capability of hemolysis estimation for areas of elevated shear stresses is valuable. The degree of hemolysis is determined by the amplitude of shear stress and the exposure time, but to date, the exact hemolytic behavior at elevated shear stresses and potential thresholds for subcritical shear exposure remain vague. This study provides experimental hemolysis data for a set of shear stresses and exposure times to allow better estimations of hemolysis for blood exposed to elevated shearing. Heparinized porcine blood with a hematocrit of 40% was mechanically damaged in a flow-through laminar Couette shear flow at a temperature of 23°C. Four levels of shear stress, 24, 592, 702, and 842 Pa, were replicated at two exposure times, 54 and 873 ms. For the calculation of the shear stresses, an apparent viscosity of 5 mPas was used, which was verified in an additional measurement of the blood viscosity. The hemolysis measurements were repeated four times, whereby all conditions were measured once within the same day and with blood from the same source. Samples were taken at the inlet and outlet of the shear region and an increase in plasma-free hemoglobin was measured. An index of hemolysis (IH) was thereby calculated giving the ratio of free to total hemoglobin. The results are compared with data from previously published studies using a similar shearing device. Hemolysis was found to increase exponentially with shear stress, but high standard deviations existed at measurements with elevated IH. At short exposure times, the IH remained low at under 0.5% for all shear stress levels. For high exposure times, the IH increased from 0.84% at 592 Pa up to 3.57% at the highest shear stress level. Hemolysis was significant for shear stresses above ∼600 Pa at the high exposure time of 873 ms. Copyright © 2014 International Center for Artificial

  14. Effects of injection pressure difference on droplet size distribution and spray cone angle in spray cooling of liquid nitrogen

    NASA Astrophysics Data System (ADS)

    Liu, Xiufang; Xue, Rong; Ruan, Yixiao; Chen, Liang; Zhang, Xingqun; Hou, Yu

    2017-04-01

    Spray cooling with liquid nitrogen as the working fluid has been widely employed in a plenty of fields requiring cooling at cryogenic temperature, such as the cryogenic wind tunnels and cooling super-conducting magnets. In this study, we built a liquid nitrogen spray system and experimentally investigated the influence of injection pressure difference on the droplet size distribution and the spray cone angle. The measurements using particle size analyser show increasing the injection pressure difference improves the atomization, as indicated by the homogenization and reduction of the droplet size. The initial spray cone angle is insensitive to the injection pressure difference. However, the far-field spray cone angle decreases dramatically with increasing the injection pressure difference. The results could enrich our knowledge of spray cooling of cryogenic fluids and benefit the design of cryogenic spray cooling systems.

  15. 40 CFR Appendix A to Subpart IIIi... - Determination of Capture Efficiency of Automobile and Light-Duty Truck Spray Booth Emissions From...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... through the waterwash and are exhausted from the controlled spray booth zone to the control device. 1.2... pass through the waterwash and be exhausted from the controlled spray booth zone to the control device... the waterwash and is exhausted from the controlled spray booth zone to the control device is equal...

  16. 42 CFR 405.205 - Coverage of a non-experimental/investigational (Category B) device.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICARE PROGRAM FEDERAL HEALTH INSURANCE FOR THE AGED AND DISABLED...). (2) CMS uses the categorization of the device as a factor in making Medicare coverage decisions....

  17. Dicopper(II) metallacyclophanes as multifunctional magnetic devices: a joint experimental and computational study.

    PubMed

    Castellano, María; Ruiz-García, Rafael; Cano, Joan; Ferrando-Soria, Jesús; Pardo, Emilio; Fortea-Pérez, Francisco R; Stiriba, Salah-Eddine; Julve, Miguel; Lloret, Francesc

    2015-03-17

    nature of these metallosupramolecular complexes. This new class of oxamato-based dicopper(II) metallacyclophanes affords an excellent synthetic and theoretical set of models for both chemical and physical fundamental studies on redox- and photo-triggered, long-distance electron exchange phenomena, which are two major topics in molecular magnetism and molecular electronics. Apart from their use as ground tests for the fundamental research on the relative importance of the spin delocalization and spin polarization mechanisms of the electron exchange interaction through extended π-conjugated aromatic ligands in polymetallic complexes, oxamato-based dicopper(II) metallacyclophanes possessing spin-containing electro- and chromophores at the metal and/or the ligand counterparts emerge as potentially active (magnetic and electronic) molecular components to build a metal-based spintronic circuit. They are thus unique examples of multifunctional magnetic complexes to get single-molecule spintronic devices by controlling and allowing the spin communication, when serving as molecular magnetic couplers and wires, or by exhibiting bistable spin behavior, when acting as molecular magnetic rectifiers and switches. Oxamato-based dicopper(II) metallacyclophanes also emerge as potential candidates for the study of coherent electron transport through single molecules, both experimentally and theoretically. The results presented herein, which are a first step in the metallosupramolecular approach to molecular spintronics, intend to attract the attention of physicists and materials scientists with a large expertice in the manipulation and measurement of single-molecule electron transport properties, as well as in the processing and addressing of molecules on different supports.

  18. Development of a New Intravascular Low-Profile Device for Exclusion of Aortic Aneurysm: An Experimental Pilot Study

    SciTech Connect

    Strecker, Ernst-Peter; Haberstroh, Joerg; Boos, Irene; Metz, Stephan; Langer, Mathias; Moliner, Manuel Maynar

    2004-09-15

    Purpose: To present a new intravascular device for the treatment of aorto-iliac aneurysms. Methods: This new device was tested in five dogs with abdominal aortic aneurysm created experimentally by overdilation of a balloon-expandable stent with a 16 or 18 mm wide PTA balloon catheter. The design of the device is based on a self-expanding aortic stent which consists of two stretchable circular frames filled with a textile Dacron mesh membrane that is suspended horizontally into the infrarenal abdominal aorta proximally to the aneurysm. The frames are part of a preshaped double helical structure that is introduced longitudinally through a catheter in a parallel fashion and forming the desired shape at the vessel site to be occluded. Two iliac stent-grafts are introduced in a low-profile status through the membrane sealing the aneurysm sac and holding the stent-grafts in place. After stent-graft expansion, a new bifurcation located more proximally than the natural one is created. The follow-up of the dogs was performed clinically and angiographically, and specimens were evaluated histomorphologically. Results: The membrane device can be introduced through a 9 Fr vascular sheath. Technical success was achieved in four of five dogs. Nine of ten stent-grafts could be fixed securely within the membrane, thus preventing dislocation. Aneurysms were excluded immediately, and blood flow to the external iliac arteries was restored by the stent-grafts. At 6-9 months follow-up of technically successful implanted devices, there were no endoleaks, no migration, no stenoses at contact sites between the implant material and vascular wall, and no stenosis or occlusion of the stent-grafts. At microscopic evaluation, the interspace between the membranes was filled with thrombotic material, thus ensuring exclusion of the aneurysm. Conclusion: This new device was found to be flexible, low profile and useful in excluding abdominal aortic aneurysm in the experimental setting.

  19. A numerical and experimental study of acoustic micromixing in 3D microchannels for lab-on-a-chip devices.

    PubMed

    Catarino, Susana O; Pinto, Vania C; Sousa, Paulo J; Lima, Rui; Miranda, Joao M; Minas, Graca

    2016-08-01

    This paper reports a numerical and experimental study of acoustic streaming and micromixing in polydimethylsiloxane microchannels. The mixing between two fluids flowing in microchannels was evaluated through the following conditions: (1) using a 28 μm thick β-poly(vinylidene fluoride) (β-PVDF) as a piezoelectric transducer actuated with a 24 Vpp and 40 MHz sinusoidal voltage; (2) using different flow rates. The results suggest that the mixing length increases as the flow rate increases and that the acoustic streaming phenomenon leads to a reduction on the mixing length. The good qualitative agreement between numerical and experimental results is a valuable indicator to predict the mixing performance of microfluidic devices, for improving biological fluid analysis in diagnosis lab-on-a-chip devices.

  20. Magnetic shield for turbomolecular pump of the Magnetized Plasma Linear Experimental device at Saha Institute of Nuclear Physics.

    PubMed

    Biswas, Subir; Chattopadhyay, Monobir; Pal, Rabindranath

    2011-01-01

    The turbo molecular pump of the Magnetized Plasma Linear Experimental device is protected from damage by a magnetic shield. As the pump runs continuously in a magnetic field environment during a plasma physics experiment, it may get damaged owing to eddy current effect. For design and testing of the shield, first we simulate in details various aspects of magnetic shield layouts using a readily available field design code. The performance of the shield made from two half cylinders of soft iron material, is experimentally observed to agree very well with the simulation results.

  1. Note: Experimental study on feasibility of a flexural traveling wave piezoelectric device for biomedical micro-electromechanical system.

    PubMed

    Marinozzi, F; Bini, F

    2014-06-01

    The aim of this paper is to experimentally show that polyvinylidene fluoride biaxially oriented in bimorph configuration is a suitable flexural traveling wave device. Piezoelectric ceramic is promising, however the lack biocompatibility is the main drawback for biomedical micro-electromechanical system. A prototype of 20 mm diameter was designed, constructed, and tested via an optical method. A first investigation was performed on two standing waves which were excited to generate the traveling wave. The findings of amplitude and phase have revealed a B31 vibration mode at 7.2 kHz and a maximum amplitude of roughly 40 nm. The flexural traveling wave was confirmed experimentally.

  2. Development and experimental verification of a finite element method for accurate analysis of a surface acoustic wave device

    NASA Astrophysics Data System (ADS)

    Mohibul Kabir, K. M.; Matthews, Glenn I.; Sabri, Ylias M.; Russo, Salvy P.; Ippolito, Samuel J.; Bhargava, Suresh K.

    2016-03-01

    Accurate analysis of surface acoustic wave (SAW) devices is highly important due to their use in ever-growing applications in electronics, telecommunication and chemical sensing. In this study, a novel approach for analyzing the SAW devices was developed based on a series of two-dimensional finite element method (FEM) simulations, which has been experimentally verified. It was found that the frequency response of the two SAW device structures, each having slightly different bandwidth and center lobe characteristics, can be successfully obtained utilizing the current density of the electrodes via FEM simulations. The two SAW structures were based on XY Lithium Niobate (LiNbO3) substrates and had two and four electrode finger pairs in both of their interdigital transducers, respectively. Later, SAW devices were fabricated in accordance with the simulated models and their measured frequency responses were found to correlate well with the obtained simulations results. The results indicated that better match between calculated and measured frequency response can be obtained when one of the input electrode finger pairs was set at zero volts and all the current density components were taken into account when calculating the frequency response of the simulated SAW device structures.

  3. Supersonic Particle Deposition (Cold Spray)

    DTIC Science & Technology

    2006-01-26

    SUPPLEMENTARY NOTES 26th Replacement of Hard Chrome and Cadmium Plating Program Review Meeting, January 24-26, 2006, San Diego, CA. Sponsored by SERDP...Spray Cu-W ( clad powder) 197 89-90 HRB Cold Spray Ta 256 21 HRC Cold Spray Ni 403 40-41 HRC Hardness of Various Cold Spray Coatings -Cold Spray

  4. An Experimental Study of Drag Reduction Devices for a Trailer Underbody and Base

    SciTech Connect

    Ortega, J M; Salari, K

    2004-05-07

    Low speed wind tunnel measurements are made on a 1/16th scale generic tractor-trailer model at a width-based Reynolds number of 325,000. The model is fixed to a turntable, allowing the yaw angle to be varied between {+-}14 degrees in 2 degree increments. Various add-on drag reduction devices are mounted to the model underbody and base. The wind-averaged drag coefficient at 65 mph is computed for each configuration, allowing the effectiveness of the add-on devices to be assessed. The most effective add-on drag reduction device for the trailer underbody is a wedge-shaped skirt, which reduces the wind-averaged drag coefficient by 2.0%. For the trailer base, the most effective add-on drag reduction device is a set of curved base flaps having a radius of curvature of 0.91 times the trailer width. These curved base flaps reduce the wind-averaged drag coefficient by 18.8%, providing the greatest drag reduction of any of the devices tested. When the wedge-shaped skirt and curved base flaps are used in conjunction with one another, the wind-averaged drag coefficient is reduced by 20%.

  5. Mechanical and in vitro evaluation of an experimental canine patent ductus arteriosus occlusion device.

    PubMed

    Wierzbicki, Mark A; Bryant, Jesse; Miller, Matthew W; Keller, Brandis; Maitland, Duncan J

    2016-06-01

    Patent ductus arteriosus (PDA) is a congenital cardiovascular malformation in which a fetal connection between the aorta and pulmonary artery remains patent after birth. This defect commonly results in clinical complications, even death, necessitating closure. Surgical ligation is the most common treatment but requires a thoracotomy and is therefore invasive. A minimally invasive option is preferable. A prototype device for PDA occlusion which utilizes shape memory polymer foams has been developed and evaluated using mechanical and in vitro experiments. Removal force and radial pressure measurements show that the prototype device exhibited a lower removal force and radial pressure than a commercially available device. The in vitro experiments conducted within simplified and physiological PDA models showed that the prototype does not migrate out of position into the pulmonary artery at either physiological or elevated pressures in multiple model configurations. While the radial pressure and removal force were lower than commercial devices, the device performed acceptably in the in vitro benchtop experiments warranting further prototype development. Copyright © 2016. Published by Elsevier Ltd.

  6. Monte-Carlo Spray Cooling Model

    NASA Astrophysics Data System (ADS)

    Kreitzer, Paul J.; Kuhlman, John M.

    2010-01-01

    Spray cooling is a tremendously complex phenomenon that has yet to be completely and successfully modeled. This is due to the complexity of the detailed droplet impingement processes and the subsequent heat transfer process. Numerous assumptions must be made in order to accurately model spray behavior. Current computational limitations restrict CFD simulations to single droplet simulations. Additional complexity due to droplet interactions negates the possibility of combining multiple single droplet studies to represent the complete spray process. Therefore, a need has been established for the development of a comprehensive spray impingement simulation with adequate physical complexity to yield accurate results within a relatively short run time. The present work attempts to develop such a model using modeling assumptions from the best available literature, and to combine them into a single spray impingement simulation. Initial flow parameters that have been chosen include flow rate of 10 GPH with a velocity of 12 m/s and average droplet diameter of 48 μm. These values produce the following non-dimensional number ranges: We 100-1800, Re 200-4500, Oh 0.01-0.05. Numerical and experimental correlations have been identified that represent crater formation, splashing, film thickness, and droplet size and spatial flux distributions. A combination of these methods has resulted in an initial spray impingement simulation that is capable of simulating 100,000 drops or an actual simulation time of 0.0167 seconds. Comparisons of results from this code with experimental results show a similar trend in surface behavior.

  7. Experimental Demonstration of Polarization Encoding Measurement-Device-Independent Quantum Key Distribution

    NASA Astrophysics Data System (ADS)

    Tang, Zhiyuan; Liao, Zhongfa; Xu, Feihu; Qi, Bing; Qian, Li; Lo, Hoi-Kwong

    2014-05-01

    We demonstrate the first implementation of polarization encoding measurement-device-independent quantum key distribution (MDI-QKD), which is immune to all detector side-channel attacks. Active phase randomization of each individual pulse is implemented to protect against attacks on imperfect sources. By optimizing the parameters in the decoy state protocol, we show that it is feasible to implement polarization encoding MDI-QKD with commercial off-the-shelf devices. A rigorous finite key analysis is applied to estimate the secure key rate. Our work paves the way for the realization of a MDI-QKD network, in which the users only need compact and low-cost state-preparation devices and can share complicated and expensive detectors provided by an untrusted network server.

  8. Initial experimental results from a laboratory size beam plasma discharge device

    NASA Technical Reports Server (NTRS)

    Konradi, A.; Bernstein, W.; Bulgher, D. L.; Garrity, J. O.; Winkler, J. L.

    1983-01-01

    A laboratory beam plasma discharge (BPD) device produced BPD in N2, A, and He. All features of the BPD observed in the device agree with those observed in a large vacuum chamber. The empirical ignition criteria determined in the large chamber apply in the small device but do not fit when used for extrapolation between the large and the small geometry. At some energies and magnetic fields beam currents exist for which the total light output in the BPD state varies by a factor of 2 with a factor of 6 pressure variation. Above 0.0001 torr the BPD width is pressure independent but for lower pressures it expands by as much as a factor of 4 at 0.00002 torr.

  9. Initial experimental results from a laboratory size beam plasma discharge device

    NASA Technical Reports Server (NTRS)

    Konradi, A.; Bernstein, W.; Bulgher, D. L.; Garrity, J. O.; Winkler, J. L.

    1983-01-01

    A laboratory beam plasma discharge (BPD) device produced BPD in N2, A, and He. All features of the BPD observed in the device agree with those observed in a large vacuum chamber. The empirical ignition criteria determined in the large chamber apply in the small device but do not fit when used for extrapolation between the large and the small geometry. At some energies and magnetic fields beam currents exist for which the total light output in the BPD state varies by a factor of 2 with a factor of 6 pressure variation. Above 0.0001 torr the BPD width is pressure independent but for lower pressures it expands by as much as a factor of 4 at 0.00002 torr.

  10. Experimental measurement-device-independent quantum key distribution with uncharacterized encoding.

    PubMed

    Wang, Chao; Wang, Shuang; Yin, Zhen-Qiang; Chen, Wei; Li, Hong-Wei; Zhang, Chun-Mei; Ding, Yu-Yang; Guo, Guang-Can; Han, Zheng-Fu

    2016-12-01

    Measurement-device-independent quantum key distribution (MDI QKD) is an efficient way to share secrets using untrusted measurement devices. However, the assumption on the characterizations of encoding states is still necessary in this promising protocol, which may lead to unnecessary complexity and potential loopholes in realistic implementations. Here, by using the mismatched-basis statistics, we present the first proof-of-principle experiment of MDI QKD with uncharacterized encoding sources. In this demonstration, the encoded states are only required to be constrained in a two-dimensional Hilbert space, and two distant parties (Alice and Bob) are resistant to state preparation flaws even if they have no idea about the detailed information of their encoding states. The positive final secure key rates of our system exhibit the feasibility of this novel protocol, and demonstrate its value for the application of secure communication with uncharacterized devices.

  11. Experimental determination of micromachined discrete and continuous device spring constants using nanoindentation method

    NASA Astrophysics Data System (ADS)

    Chan, M. L.; Tay, Francis E.; Logeeswaran, V. J.; Zeng, Kaiyang; Shen, Lu; Chau, Fook S.

    2002-04-01

    A rapid and accurate static and quasi-static method for determining the out-of-plane spring constraints of cantilevers and a micromachined vibratory sensor is presented. In the past, much of the effort in nanoindentation application was to investigate the thin-film mechanical properties. In this paper, we have utilized the nanoindentation method to measure directly some micromachined device (e.g. microgyroscope) spring constants. The cantilevers and devices tested were fabricated using the MUMPS process and an SOI process (patent pending). Spring constants are determined using a commercial nanoindentation apparatus UMIS-2000 configured with both Berkovich and spherical indenter tip that can be placed onto the device with high accuracy. Typical load resolution is 20micrometers N to 0.5N and a displacement resolution of 0.05nm. Information was deduced from the penetration depth versus load curves during both loading and unloading.

  12. A modified device for long term sampling of parotid saliva in various experimental conditions.

    PubMed

    Takayanagi, A; Nomura, T; Yamanaka, S; Takaesu, Y

    1995-05-01

    A parotid cup has been widely used as an intraoral device for the collection of parotid saliva. However, in long duration sampling, the cup tends to disconnect under circumstances such as mastication, sleep or physical exercise. We have designed a modified device of parotid cup for saliva collection to overcome these unfavorable conditions. The parotid cup was modified by fixing it to the bite-plate appliance which was adjusted individually to the occlusal plane in order to avoid disconnection of the cup under varying conditions. Using this device, we could measure salivary flow rate during mastication, sleep or physical exercise. Additional advantages of this device are that it is easy to make with acrylic resin and is inexpensive. The preliminary study using this device showed that flow rates of unstimulated parotid saliva varied from 0.06 +/- 0.04 ml/min. to 0.16 +/- 0.10 ml/min. (mean +/- s.d) from 7 a.m. to 12 p.m. in 7 subjects. In five subjects, the flow rate of parotid saliva during meal (lunch) was much higher than that of resting on a chair, playing table tennis, or sleeping at night for 6-8 hours. This might be considered due to the stimuli of the meal content. Flow rates of saliva were also examined with various stimuli. The results showed that salty pickled plum > sour lemon juice > 10% ascorbic acid > sweet milky candy > 1% ascorbic acid. These data suggest that our modified device is useful for various experiments in salivary research.

  13. Optimization of the bake-on siliconization of cartridges. Part I: Optimization of the spray-on parameters.

    PubMed

    Funke, Stefanie; Matilainen, Julia; Nalenz, Heiko; Bechtold-Peters, Karoline; Mahler, Hanns-Christian; Friess, Wolfgang

    2016-07-01

    Biopharmaceutical products are increasingly commercialized as drug/device combinations to enable self-administration. Siliconization of the inner syringe/cartridge glass barrel for adequate functionality is either performed at the supplier or drug product manufacturing site. Yet, siliconization processes are often insufficiently investigated. In this study, an optimized bake-on siliconization process for cartridges using a pilot-scale siliconization unit was developed. The following process parameters were investigated: spray quantity, nozzle position, spray pressure, time for pump dosing and the silicone emulsion concentration. A spray quantity of 4mg emulsion showed best, immediate atomization into a fine spray. 16 and 29mg of emulsion, hence 4-7-times the spray volume, first generated an emulsion jet before atomization was achieved. Poor atomization of higher quantities correlated with an increased spray loss and inhomogeneous silicone distribution, e.g., due to runlets forming build-ups at the cartridge lower edge and depositing on the star wheel. A prolonged time for pump dosing of 175ms led to a more intensive, long-lasting spray compared to 60ms as anticipated from a higher air-to-liquid ratio. A higher spray pressure of 2.5bar did not improve atomization but led to an increased spray loss. At a 20mm nozzle-to-flange distance the spray cone exactly reached the cartridge flange, which was optimal for thicker silicone layers at the flange to ease piston break-loose. Initially, 10μg silicone was sufficient for adequate extrusion in filled cartridges. However, both maximum break-loose and gliding forces in filled cartridges gradually increased from 5-8N to 21-22N upon 80weeks storage at room temperature. The increase for a 30μg silicone level from 3-6N to 10-12N was moderate. Overall, the study provides a comprehensive insight into critical process parameters during the initial spray-on process and the impact of these parameters on the characteristics of the

  14. Bear Spray Safety Program

    USGS Publications Warehouse

    Blome, C.D.; Kuzniar, R.L.

    2009-01-01

    A bear spray safety program for the U.S. Geological Survey (USGS) was officially initiated by the Firearms Safety Committee to address accident prevention and to promote personnel training in bear spray and its transportation, storage, and use for defense against wild animals. Used as part of a system including firearms, or used alone for those who choose not to carry a firearm, bear spray is recognized as an effective tool that can prevent injury in a wild animal attack.

  15. Spray drying technique. I: Hardware and process parameters.

    PubMed

    Cal, Krzysztof; Sollohub, Krzysztof

    2010-02-01

    Spray drying is a transformation of feed from a fluid state into a dried particulate form by spraying the feed into a hot drying medium. The main aim of drying by this method in pharmaceutical technology is to obtain dry particles with desired properties. This review presents the hardware and process parameters that affect the properties of the dried product. The atomization devices, drying chambers, air-droplet contact systems, the collection of dried product, auxiliary devices, the conduct of the spray drying process, and the significance of the individual parameters in the drying process, as well as the obtained product, are described and discussed.

  16. Preparation of Partial-Thickness Burn Wounds in Rodents Using a New Experimental Burning Device.

    PubMed

    Sakamoto, Michiharu; Morimoto, Naoki; Ogino, Shuichi; Jinno, Chizuru; Kawaguchi, Atsushi; Kawai, Katsuya; Suzuki, Shigehiko

    2016-06-01

    The manual application of hot water or hot metal to an animal's skin surface is often used to prepare burn wound models. However, manual burn creation is subject to human variability. We developed a new device that can control the temperature, time, and pressure of contact to produce precise and reproducible animal burn wounds and investigated the conditions required to prepare various burn wounds using our new device. We prepared burn wounds on F344 rats using 3 contact times 2, 4, and 10 seconds using a stamp heated to 80°C. We observed the wound-healing process macroscopically and histologically and evaluated the burn depth using a laser speckle contrast-imaging device, which evaluated the blood flow of the wound. The changes in the burned area over time, tissue perfusion of the burn wounds, histological evaluation of the burn depth by hematoxylin-eosin and azocarmine and aniline blue staining, and the epithelialization rate (the ratio of the epithelialized area to the wound length) were evaluated on histological sections. Results indicated that the burn wounds prepared with contact times of 2, 4, and 10 seconds corresponded to superficial dermal burns, deep dermal burns, and full-thickness burns, respectively. We demonstrated that partial- and full-thickness burn wounds can be precisely and reproducibly created with our new automated burning device.

  17. Experimental and Theoretical Assessment of a Device Used for Evaluation of Blast and Fragmentation Effects

    NASA Astrophysics Data System (ADS)

    Resnyansky, Anatoly; Weckert, Samuel

    2007-06-01

    An alternative to traditional momentum pendulum and pressure gages is sought to resolve an improved temporal response to blast and fragmentation and protect the evaluation device from damage when positioned closely to the source of blast. Evaluation concepts based on the use of strain gages have been used for some time in the scientific community. However, those devices either produce extensive parasitic oscillations or are restricted for use in close proximity to the source of the blast and during a short time only. An alternative design is suggested and analysed that can extend the analysis time to several milliseconds and can be used both in close proximity and at relatively large stand-off distances from the source of the blast. The device employs conventional strain gauges that are heavily protected from the blast and fragmentation. Numerical analysis demonstrates ways to minimise the system oscillations and these ways were partly implemented in the present system. A gas gun fitted with a diverging nozzle has been used to validate a version of the system, which was tested in the range of pressures representative of those occurring several meters from a moderate size explosive charge. The test results and simulation demonstrate the potential for using this type of devices in the field trial settings that involve the blast and fragmentation effects.

  18. Non-superconducting magnet structures for near-term, large fusion experimental devices

    SciTech Connect

    File, J.; Knutson, D.S.; Marino, R.E.; Rappe, G.H.

    1980-10-01

    This paper describes the magnet and structural design in the following American tokamak devices: the Princeton Large Torus (PLT), the Princeton Divertor Experiment (PDX), and the Tokamak Fusion Test Reactor (TFTR). The Joint European Torus (JET), also presented herein, has a magnet structure evolved from several European programs and, like TFTR, represents state of the art magnet and structure design.

  19. Vacuum Plasma Sprayed Metallic Coatings

    NASA Astrophysics Data System (ADS)

    Shankar, S.; Koenig, D. E.; Dardi, L. E.

    1981-10-01

    Recognizing the fundamental cost advantage, technical capabilities, and compositional flexibility of reduced pressure (vacuum) plasma spraying compared to other overlay coating methods, an advanced, second generation, closed chamber deposition process called VPX (a Howmet trademark) was developed. An automated experimental facility for coating gas turbine engine components was also constructed. This paper describes several important features of the process and equipment. It shows that the use of optimized spray parameters combined with an appropriate schedule of relative orientations between the gun and work-piece can be used to produce dense and highly reproducible coatings of either uniform or controlled thickness distributions. The chemical composition, microstructure, and interfacial characteristics of typical MCrAlY coatings are reported. Some effects of operating procedures and MCrAlY chemical composition on coating density are noted. The results of mechanical property and burner rig tests of coated material are also described.

  20. An oxygen pressure sensor using surface acoustic wave devices

    NASA Technical Reports Server (NTRS)

    Leighty, Bradley D.; Upchurch, Billy T.; Oglesby, Donald M.

    1993-01-01

    Surface acoustic wave (SAW) piezoelectric devices are finding widespread applications in many arenas, particularly in the area of chemical sensing. We have developed an oxygen pressure sensor based on coating a SAW device with an oxygen binding agent which can be tailored to provide variable sensitivity. The coating is prepared by dissolving an oxygen binding agent in a toluene solution of a copolymer which is then sprayed onto the surface of the SAW device. Experimental data shows the feasibility of tailoring sensors to measure the partial pressure of oxygen from 2.6 to 67 KPa (20 to 500 torr). Potential applications of this technology are discussed.

  1. Surface acoustic wave vapor sensors based on resonator devices

    NASA Astrophysics Data System (ADS)

    Grate, Jay W.; Klusty, Mark

    1991-05-01

    Surface acoustic wave (SAW) devices fabricated in the resonator configuration have been used as organic vapor sensors and compared with delay line devices more commonly used. The experimentally determined mass sensitivities of 200, 300, and 400 MHz resonators and 158 MHz delay lines coated with Langmuir-Blodgett films of poly(vinyl tetradecanal) are in excellent agreement with theoretical predictions. The response of LB- and spray-coated sensors to various organic vapors were determined, and scaling laws for mass sensitivities, vapor sensitivities, and detection limits are discussed. The 200 MHz resonators provide the lowest noise levels and detection limits of all the devices examined.

  2. Power transient analyses of experimental in-reflector devices during safety shutdown in Jules Horowitz Reactor (JHR)

    SciTech Connect

    Camprini, P. C.; Sumini, M.; Artioli, C.; Gonnier, C.; Pouchin, B.; Bourdon, S.

    2012-07-01

    The Jules Horowitz Reactor (JHR) is designed to be a 100 MW material testing reactor (MTR) and it is expected to become the reference facility in the framework of European nuclear research activity. As the core neutron spectrum is quite fast, several experimental devices concerning fuel studies have been conceived to be placed in the reflector in order to exploit a proper thermal neutron flux irradiation. Since the core power is relatively high, the neutronic coupling between the reactor core and the reflector devices has to be taken into account for different rod insertions. In fact the thermal power produced within the fuel samples is considerable. Heat removal during shutdown is a main topic in nuclear safety and it is worth to analyse thermal power transients in fuel samples as well. Here a thermal hydraulic model for JHR core is proposed aiming at a simple and representative description as far as reactivity feedbacks are concerned. Then it is coupled with a neutronic pointwise kinetics analysis by means of the DULCINEE code to compute core power transient calculations. Moreover, some reflector-core coupling evaluations are performed through Monte Carlo method using the TRIPOLI 4.7 code. The JHR equilibrium cycle is considered with respect to four fuel compositions namely Beginning of Cycle (BOC), Xenon Saturation Point (XSP), Middle of Cycle (MOC) and End of Cycle (EOC). Then thermal power transients in the experimental reflector devices are evaluated during safety shutdowns and they are verified for all these cycle steps. (authors)

  3. Experimental Electron Temperature Gradient Dependence of Heavy Impurity Transport in Fusion Devices

    SciTech Connect

    Villegas, D.; Guirlet, R.; Bourdelle, C.; Hoang, G. T.; Garbet, X.; Sabot, R.

    2010-07-16

    The turbulent impurity (nickel) transport dependence on the normalized electron temperature gradient has been analyzed in sawtooth-free electron cyclotron wave heated Tore Supra plasmas. In the core, our experimental analysis shows that the lower R/L{sub T{sub e}}, the lower the nickel diffusion coefficient. The latter decreases until the instability threshold is reached. The experimental threshold is in agreement with the one computed by a gyrokinetic model. Further out, R/L{sub T{sub e}} plays no role in the impurity diffusion. This set of experimental results is consistent with a quasilinear gyrokinetic analysis.

  4. Experimental measurement-device-independent quantum digital signatures over a metropolitan network

    NASA Astrophysics Data System (ADS)

    Yin, Hua-Lei; Wang, Wei-Long; Tang, Yan-Lin; Zhao, Qi; Liu, Hui; Sun, Xiang-Xiang; Zhang, Wei-Jun; Li, Hao; Puthoor, Ittoop Vergheese; You, Li-Xing; Andersson, Erika; Wang, Zhen; Liu, Yang; Jiang, Xiao; Ma, Xiongfeng; Zhang, Qiang; Curty, Marcos; Chen, Teng-Yun; Pan, Jian-Wei

    2017-04-01

    Quantum digital signatures (QDSs) provide a means for signing electronic communications with information-theoretic security. However, all previous demonstrations of quantum digital signatures assume trusted measurement devices. This renders them vulnerable against detector side-channel attacks, just like quantum key distribution. Here we exploit a measurement-device-independent (MDI) quantum network, over a metropolitan area, to perform a field test of a three-party MDI QDS scheme that is secure against any detector side-channel attack. In so doing, we are able to successfully sign a binary message with a security level of about 10-7. Remarkably, our work demonstrates the feasibility of MDI QDSs for practical applications.

  5. Simulative and experimental research on wireless power transmission technique in implantable medical device.

    PubMed

    Yu, Yue; Hao, Hongwei; Wang, Weiming; Li, Luming

    2009-01-01

    As the development of implantable biomedical devices, the rechargeable battery is applied to improve the life of implantable devices. Inductive transcutaneous power transfer, as a suitable way of charging the implantable rechargeable batteries, is widely used. During charging period, there are several stages based on the charging rule and the load resistance is varying simultaneously. In this paper, a model of inductive transcutaneous power transfer is set up with a compensative capacitor for primary coil in series and another compensative capacitor for secondary coil in parallel to descript the relationship in coupling coefficient, load resistance and conversion efficiency. Simulations were done and experiments were carried out to verify the model, and some suggestions on wireless power transfer design are given.

  6. Structure design and experimental research on the electric-pneumatic transfer device with piezoelectric actuator

    NASA Astrophysics Data System (ADS)

    Li, Dong-Ming; Sun, Bao-yuan; Wang, Wei; Jia, Ying

    2008-10-01

    Electric-pneumatic transducer and electric-pneumatic positional valve has advantages of fire protection, explosion protection and lifetime dilatation etc, and are widely used in industrial automatic production. In this paper, two new electric-pneumatic transfer device with piezoelectric actuator whose structure and operating principle are proposed. One is based on the principle of nozzle-flapper, the other is based on opening-closing. Experiment research was carried on and the results show that the new transfer devices can meet requirement of air pressure output between 0.02MPa and 0.1MPa in industrial field with low voltage, which provides good basis of development of electric-pneumatic transducer valve with new piezoelectric structure.

  7. Experimental results in evolutionary fault-recovery for field programmable analog devices

    NASA Technical Reports Server (NTRS)

    Zebulum, Ricardo S.; Keymeulen, Didier; Duong, Vu; Guo, Xin; Ferguson, M. I.; Stoica, Adrian

    2003-01-01

    This paper presents experimental results of fast intrinsic evolutionary design and evolutionary fault recovery of a 4-bit Digital to Analog Converter (DAC) using the JPL stand-alone board-level evolvable system (SABLES).

  8. Coanda-Assisted Spray Manipulation Collar for a Commercial Plasma Spray Gun

    NASA Astrophysics Data System (ADS)

    Mabey, K.; Smith, B. L.; Whichard, G.; McKechnie, T.

    2011-06-01

    A Coanda-assisted Spray Manipulation (CSM) collar was retrofitted to a Praxair SG-100 plasma spray gun. The CSM device makes it possible to change the direction of (vector) the plasma jet and powder without moving the gun. The two-piece retrofit device replaces the standard faceplate. Two separate collars were tested: one designed for small vector angles and one for larger vector angles. It was demonstrated that the small-angle device could modify the trajectory of zirconia powder up to several degrees. Doing so could realign the plasma with the powder resulting in increased powder temperature and velocity. The large-angle device was capable of vectoring the plasma jet up to 45°. However, the powder did not vector as much. Under large-angle vectoring, the powder velocity and temperature decreased steadily with vector angle. Both devices were tested using a supersonic configuration to demonstrate that CSM is capable of vectoring supersonic plasmas.

  9. Different experimental protocols for decontamination affect the cleaning of medical devices. A preliminary electron microscopy analysis.

    PubMed

    Tessarolo, F; Caola, I; Fedel, M; Stacchiotti, A; Caciagli, P; Guarrera, G M; Motta, A; Nollo, G

    2007-04-01

    The aim of the present study was to examine the efficiency of different decontamination-cleaning protocols on blood-soiled catheters used for interventional cardiology. Electrophysiology and cardiac ablation disposable devices were contaminated with bacteria-spiked human blood and underwent four different pre-sterilization protocols, including a chlorine-releasing agent, a polyphenolic emulsion, and an enzymatic detergent. Treated samples were examined by optical microscopy, scanning electron microscopy and transmission electron microscopy to identify and characterize biological and inorganic residuals. The use of chlorine as a first treatment caused denaturation of serum proteins and adherence of blood components to the surface of the device, thus hindering the cleaning efficiency of subsequent treatments with enzymatic detergents. An enzymatic/chlorine protocol was more efficient, but was considered to be a greater risk to healthcare staff. Polyphenolic-based treatments had the highest level of efficiency in bioburden removal, but interaction and adsorption of this class of chemicals onto biopolymers might lead to serious concerns about toxicity on subsequent reuse. Adequate pre-sterilization cleaning is fundamental for sterilization success and high-resolution electron microscopy can provide significant and detailed information about the efficiency of chemicals used for cleaning a blood-soiled device.

  10. Experimentally realizable devices for controlling the motion of magnetic flux quanta in anisotropic superconductors.

    PubMed

    Savel'ev, Sergey; Nori, Franco

    2002-11-01

    A new generation of microscopic ratchet systems is currently being developed for controlling the motion of electrons and fluxons, as well as for particle separation and electrophoresis. Virtually all of these use static spatially asymmetric potential energies to control transport properties. Here we propose completely new types of ratchet-like systems that do not require fixed spatially asymmetric potentials in the samples. As specific examples of this novel general class of ratchets, we propose devices that control the motion of flux quanta in superconductors and could address a central problem in many superconducting devices; namely, the removal of trapped magnetic flux that produces noise. In layered superconductors there are two interpenetrating perpendicular vortex lattices consisting of Josephson vortices (JVs) and pancake vortices (PVs). We show that, owing to the JV-PV mutual interaction and asymmetric driving, the a.c. motion of JVs and/or PVs can provide a net d.c. vortex current. This controllable vortex motion can be used for making pumps, diodes and lenses of quantized magnetic flux. These proposed devices sculpt the microscopic magnetic flux profile by simply modifying the time dependence of the a.c. drive, without the need for samples with static pinning--for example, without lithography or irradiation.

  11. Physiological responses of adult rainbow trout experimentally released through a unique fish conveyance device

    USGS Publications Warehouse

    Mesa, Matthew G.; Gee, Lisa P.; Weiland, Lisa K.; Christiansen, Helena E.

    2013-01-01

    We assessed the physiological stress responses (i.e., plasma levels of cortisol, glucose, and lactate) of adult Rainbow Trout Oncorhynchus mykiss at selected time intervals after they had passed a distance of 15 m through a unique fish conveyance device (treatment fish) or not (controls). This device differs from traditional fish pumps in two important ways: (1) it transports objects in air, rather than pumping them from and with water; and (2) it uses a unique tube for transport that has a series of soft, deformable baffles spaced evenly apart and situated perpendicular within a rigid, but flexible outer shell. Mean concentrations of the plasma constituents never differed (P > 0.05) between control and treatment fish at 0, 1, 4, 8, or 24 h after passage, and only minor differences were apparent between the different time intervals within a group. We observed no obvious injuries on any of our fish. Our results indicate that passage through this device did not severely stress or injure fish and it may allow for the rapid and safe movement of fish at hatcheries, sorting or handling facilities, or passage obstacles.

  12. Measuring Spray Droplet Size from Agricultural Nozzles Using Laser Diffraction

    PubMed Central

    Fritz, Bradley K.; Hoffmann, W. Clint

    2016-01-01

    When making an application of any crop protection material such as an herbicide or pesticide, the applicator uses a variety of skills and information to make an application so that the material reaches the target site (i.e., plant). Information critical in this process is the droplet size that a particular spray nozzle, spray pressure, and spray solution combination generates, as droplet size greatly influences product efficacy and how the spray moves through the environment. Researchers and product manufacturers commonly use laser diffraction equipment to measure the spray droplet size in laboratory wind tunnels. The work presented here describes methods used in making spray droplet size measurements with laser diffraction equipment for both ground and aerial application scenarios that can be used to ensure inter- and intra-laboratory precision while minimizing sampling bias associated with laser diffraction systems. Maintaining critical measurement distances and concurrent airflow throughout the testing process is key to this precision. Real time data quality analysis is also critical to preventing excess variation in the data or extraneous inclusion of erroneous data. Some limitations of this method include atypical spray nozzles, spray solutions or application conditions that result in spray streams that do not fully atomize within the measurement distances discussed. Successful adaption of this method can provide a highly efficient method for evaluation of the performance of agrochemical spray application nozzles under a variety of operational settings. Also discussed are potential experimental design considerations that can be included to enhance functionality of the data collected. PMID:27684589

  13. Measuring Spray Droplet Size from Agricultural Nozzles Using Laser Diffraction.

    PubMed

    Fritz, Bradley K; Hoffmann, W Clint

    2016-09-16

    When making an application of any crop protection material such as an herbicide or pesticide, the applicator uses a variety of skills and information to make an application so that the material reaches the target site (i.e., plant). Information critical in this process is the droplet size that a particular spray nozzle, spray pressure, and spray solution combination generates, as droplet size greatly influences product efficacy and how the spray moves through the environment. Researchers and product manufacturers commonly use laser diffraction equipment to measure the spray droplet size in laboratory wind tunnels. The work presented here describes methods used in making spray droplet size measurements with laser diffraction equipment for both ground and aerial application scenarios that can be used to ensure inter- and intra-laboratory precision while minimizing sampling bias associated with laser diffraction systems. Maintaining critical measurement distances and concurrent airflow throughout the testing process is key to this precision. Real time data quality analysis is also critical to preventing excess variation in the data or extraneous inclusion of erroneous data. Some limitations of this method include atypical spray nozzles, spray solutions or application conditions that result in spray streams that do not fully atomize within the measurement distances discussed. Successful adaption of this method can provide a highly efficient method for evaluation of the performance of agrochemical spray application nozzles under a variety of operational settings. Also discussed are potential experimental design considerations that can be included to enhance functionality of the data collected.

  14. The role of drop velocity in statistical spray description

    NASA Technical Reports Server (NTRS)

    Groeneweg, J. F.; El-Wakil, M. M.; Myers, P. S.; Uyehara, O. A.

    1978-01-01

    The justification for describing a spray by treating drop velocity as a random variable on an equal statistical basis with drop size was studied experimentally. A double exposure technique using fluorescent drop photography was used to make size and velocity measurements at selected locations in a steady ethanol spray formed by a swirl atomizer. The size velocity data were categorized to construct bivariate spray density functions to describe the spray immediately after formation and during downstream propagation. Bimodal density functions were formed by environmental interaction during downstream propagation. Large differences were also found between spatial mass density and mass flux size distribution at the same location.

  15. Experimental methods in aquatic respirometry: the importance of mixing devices and accounting for background respiration.

    PubMed

    Rodgers, G G; Tenzing, P; Clark, T D

    2016-01-01

    In light of an increasing trend in fish biology towards using static respirometry techniques without the inclusion of a mixing mechanism and without accurately accounting for the influence of microbial (background) respiration, this paper quantifies the effect of these approaches on the oxygen consumption rates (ṀO2 ) measured from juvenile barramundi Lates calcarifer (mean ± s.e. mass = 20·31 ± 0·81 g) and adult spiny chromis damselfish Acanthochromis polyacanthus (22·03 ± 2·53 g). Background respiration changed consistently and in a sigmoidal manner over time in the treatment with a mixing device (inline recirculation pump), whereas attempts to measure background respiration in the non-mixed treatment yielded highly variable estimates of ṀO2 that were probably artefacts due to the lack of water movement over the oxygen sensor during measurement periods. This had clear consequences when accounting for background respiration in the calculations of fish ṀO2 . Exclusion of a mixing device caused a significantly lower estimate of ṀO2 in both species and reduced the capacity to detect differences between individuals as well as differences within an individual over time. There was evidence to suggest that the magnitude of these effects was dependent on the spontaneous activity levels of the fish, as the difference between mixed and non-mixed treatments was more pronounced for L. calcarifer (sedentary) than for A. polyacanthus (more spontaneously active). It is clear that respirometry set-ups for sedentary species must contain a mixing device to prevent oxygen stratification inside the respirometer. While more active species may provide a higher level of water mixing during respirometry measurements and theoretically reduce the need for a mixing device, the level of mixing cannot be quantified and may change with diurnal cycles in activity. To ensure consistency across studies without relying on fish activity levels, and to enable accurate assessments of

  16. Cold spray nozzle design

    DOEpatents

    Haynes, Jeffrey D.; Sanders, Stuart A.

    2009-06-09

    A nozzle for use in a cold spray technique is described. The nozzle has a passageway for spraying a powder material, the passageway having a converging section and a diverging section, and at least the diverging section being formed from polybenzimidazole. In one embodiment of the nozzle, the converging section is also formed from polybenzimidazole.

  17. Statistical modeling of ammonia absorption in an acid spray scrubber

    USDA-ARS?s Scientific Manuscript database

    The use of acid spray wet scrubbers for recovering ammonia (NH3) emissions is promising due to its high NH3 removal efficiency, simplicity in design, and minimal pressure drop contribution on fans. An experimental study was conducted to evaluate the performance of a lab-optimised acid spray scrubber...

  18. Structure of high-speed sprays

    NASA Astrophysics Data System (ADS)

    Bracco, Frediano V.

    1995-01-01

    This work covered both measurements and computations and its results are documented in eight appendices. Measurements were made of drop velocity in vaporizing, steady, full-cone sprays and of drop velocity and drop size in non-vaporizing steady full-cone sprays. In similar conditions, measurements had previously been made of the intact core and of the size of the drops in the immediate vicinity of the injector, thus generating an extensive set of data which were particularly useful for the assessment and the development of multidimensional models of engine sprays. On the computational side, a line source technique was introduced to simulate the intact-core in engine sprays and two extensive numerical studies were carried out to explain the strong anisotropy of the drop velocity fluctuations that had been found in the measurements. In another interesting and timely study, the accuracy of the stochastic method of computing drop collisions and coalescence (which is the one universally used) was assessed by corresponding deterministic computations (more accurate but much more time consuming). It was concluded that the accuracy of the stochastic method in practical computations can be wanting. Finally, a numerical study of the structure of hollow-cone sprays was initiated that has since been followed by significant experimental and computational work on liquid-only and air-assisted hollow-cone injectors and sprays.

  19. Environmentally compatible spray cement

    SciTech Connect

    Loeschnig, P.

    1995-12-31

    Within the framework of a European research project, Heidelberger Zement developed a quickly setting and hardening binder for shotcrete, called Chronolith S, which avoids the application of setting accelerators. Density and strength of the shotcrete produced with this spray cement correspond to those of an unaccelerated shotcrete. An increased hazard for the heading team and for the environment, which may occur when applying setting accelerators, can be excluded here. Owing to the special setting properties of a spray cement, the process engineering for its manufacturing is of great importance. The treatment of a spray cement as a dry concrete with kiln-dried aggregates is possible without any problems. The use of a naturally damp pre-batched mixture is possible with Chronolith S but requires special process engineering; spray cement and damp aggregate are mixed with one another immediately before entering the spraying machinery.

  20. Spark Ignition of Monodisperse Fuel Sprays. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Danis, Allen M.; Cernansky, Nicholas P.; Namer, Izak

    1987-01-01

    A study of spark ignition energy requirements was conducted with a monodisperse spray system allowing independent control of droplet size, equivalent ratio, and fuel type. Minimum ignition energies were measured for n-heptane and methanol sprays characterized at the spark gap in terms of droplet diameter, equivalence ratio (number density) and extent of prevaporization. In addition to sprays, minimum ignition energies were measured for completely prevaporized mixtures of the same fuels over a range of equivalence ratios to provide data at the lower limit of droplet size. Results showed that spray ignition was enhanced with decreasing droplet size and increasing equivalence ratio over the ranges of the parameters studied. By comparing spray and prevaporized ignition results, the existence of an optimum droplet size for ignition was indicated for both fuels. Fuel volatility was seen to be a critical factor in spray ignition. The spray ignition results were analyzed using two different empirical ignition models for quiescent mixtures. Both models accurately predicted the experimental ignition energies for the majority of the spray conditions. Spray ignition was observed to be probabilistic in nature, and ignition was quantified in terms of an ignition frequency for a given spark energy. A model was developed to predict ignition frequencies based on the variation in spark energy and equivalence ratio in the spark gap. The resulting ignition frequency simulations were nearly identical to the experimentally observed values.

  1. An experimental study addressing the use of geoforensic analysis for the exploitation of improvised explosive devices (IEDs).

    PubMed

    Wilks, Beth; Morgan, Ruth M; Rose, Neil L

    2017-09-01

    The use of geoforensic analysis in criminal investigations is continuing to develop, with the diversification of analytical techniques, many of which are semi-automated, facilitating prompt analysis of large sample sets at a relatively low cost. Whilst micro-scale geoforensic analysis has been shown to assist criminal investigations including homicide (Concheri et al., 2011 [1]), wildlife crime (Morgan et al., 2006 [2]), illicit drug distribution (Stanley, 1992 [3]), and burglary (Mildenhall, 2006 [4]), its application to the pressing international security threat posed by Improvised Explosive Devices (IEDs) is yet to be considered. This experimental study simulated an IED supply chain from the sourcing of raw materials through to device emplacement. Mineralogy, quartz grain surface texture analysis (QGSTA) and particle size analysis (PSA) were used to assess whether environmental materials were transferred and subsequently persisted on the different components of three pressure plate IEDs. The research also addressed whether these samples were comprised of material from single or multiple geographical provenances that represented supply chain activity nodes. The simulation demonstrated that material derived from multiple activity nodes, was transferred and persisted on device components. The results from the mineralogy and QGSTA illustrated the value these techniques offer for the analysis of mixed provenance samples. The results from the PSA, which produces a bulk signature of the sample, failed to distinguish multiple provenances. The study also considered how the environmental material recovered could be used to generate information regarding the geographical locations the device had been in contact with, in an intelligence style investigation, and demonstrated that geoforensic analysis has the potential to be of value to international counter-IED efforts. It is a tool that may be used to prevent the distribution of large quantities of devices, by aiding the

  2. Spray measurement technology: a review

    NASA Astrophysics Data System (ADS)

    Fansler, Todd D.; Parrish, Scott E.

    2015-01-01

    Sprays are among the most intellectually challenging and practically important topics in fluid mechanics. This paper reviews needs, milestones, challenges, and a broad array of techniques for spray measurement. In addition, tabular summaries provide cross-referenced entry points to the vast literature by organizing over 300 citations according to key spray phenomena, physical parameters and measurement techniques for each of the principal spray regions (nozzle internal flow, near-field spray-formation region, far-field developed spray, and spray-wall interaction). The article closes with perspectives on some current issues in spray research, including the cost and complexity of apparatus for spray physics and spray engineering, the need for simultaneous diagnostic measurements under application-relevant conditions, and the effective comparison of spray measurements and numerical simulations.

  3. Spray Rolling Aluminum Strip

    SciTech Connect

    Lavernia, E.J.; Delplanque, J-P; McHugh, K.M.

    2006-05-10

    Spray forming is a competitive low-cost alternative to ingot metallurgy for manufacturing ferrous and non-ferrous alloy shapes. It produces materials with a reduced number of processing steps, while maintaining materials properties, with the possibility of near-net-shape manufacturing. However, there are several hurdles to large-scale commercial adoption of spray forming: 1) ensuring strip is consistently flat, 2) eliminating porosity, particularly at the deposit/substrate interface, and 3) improving material yield. Through this program, a new strip/sheet casting process, termed spray rolling, has been developed, which is an innovative manufacturing technique to produce aluminum net-shape products. Spray rolling combines the benefits of twin-roll casting and conventional spray forming, showing a promising potential to overcome the above hurdles associated with spray forming. Spray rolling requires less energy and generates less scrap than conventional processes and, consequently, enables the development of materials with lower environmental impacts in both processing and final products. Spray Rolling was developed as a collaborative project between the University of California-Davis, the Colorado School of Mines, the Idaho National Engineering and Environmental Laboratory, and an industry team. The following objectives of this project were achieved: (1) Demonstration of the feasibility of the spray rolling process at the bench-scale level and evaluation of the materials properties of spray rolled aluminum strip alloys; and (2) Demonstration of 2X scalability of the process and documentation of technical hurdles to further scale up and initiate technology transfer to industry for eventual commercialization of the process.

  4. Malfunction of cardiac devices after radiotherapy without direct exposure to ionizing radiation: mechanisms and experimental data.

    PubMed

    Zecchin, Massimo; Morea, Gaetano; Severgnini, Mara; Sergi, Elisabetta; Baratto Roldan, Anna; Bianco, Elisabetta; Magnani, Silvia; De Luca, Antonio; Zorzin Fantasia, Anna; Salvatore, Luca; Milan, Vittorino; Giannini, Gianrossano; Sinagra, Gianfranco

    2016-02-01

    Malfunctions of cardiac implantable electronical devices (CIED) have been described after high-energy radiation therapy even in the absence of direct exposure to ionizing radiation, due to diffusion of neutrons (n) causing soft errors in inner circuits. The purpose of the study was to analyse the effect of scattered radiation on different types and models of CIED and the possible sources of malfunctions. Fifty-nine explanted CIED were placed on an anthropomorphous phantom of tissue-equivalent material, and a high-energy photon (15 MV) radiotherapy course (total dose = 70 Gy) for prostate treatment was performed. All devices were interrogated before and after radiation. Radiation dose, the electromagnetic field, and neutron fluence at the CIED site were measured. Thirty-four pacemakers (PM) and 25 implantable cardioverter-defibrillators (ICD) were analysed. No malfunctions were detected before radiation. After radiation a software malfunction was evident in 13 (52%) ICD and 6 (18%) PM; no significant electromagnetic field or photon radiations were detected in the thoracic region. Neutron capture was demonstrated by the presence of the (198)Au((197)Au + n) or (192)Ir((191)Ir + n) isotope activation; it was significantly greater in ICD than in PM and non-significantly greater in damaged devices. A greater effect in St Jude PM (2/2 damaged), Boston (9/11), and St Jude ICD (3/6) and in older ICD models was observed; the year of production was not relevant in PM. High-energy radiation can cause different malfunctions on CIED, particularly ICD, even without direct exposure to ionizing radiation due to scattered radiation of neutrons produced by the linear accelerator. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  5. Simulation of preburner sprays, volumes 1 and 2

    NASA Technical Reports Server (NTRS)

    Hardalupas, Y.; Whitelaw, J. H.

    1993-01-01

    The present study considered characteristics of sprays under a variety of conditions. Control of these sprays is important as the spray details can control both rocket combustion stability and efficiency. Under the present study Imperial College considered the following: (1) Measurement of the size and rate of spread of the sprays produced by single coaxial airblast nozzles with axial gaseous stream. The local size, velocity, and flux characteristics for a wide range of gas and liquid flowrates were measured, and the results were correlated with the conditions of the spray at the nozzle exit. (2) Examination of the effect of the geometry of single coaxial airblast atomizers on spray characteristics. The gas and liquid tube diameters were varied over a range of values, the liquid tube recess was varied, and the shape of the exit of the gaseous jet was varied from straight to converging. (3) Quantification of the effect of swirl in the gaseous stream on the spray characteristics produced by single coaxial airblast nozzles. (4) Quantification of the effect of reatomization by impingement of the spray on a flat disc positioned around 200 mm from the nozzle exit. This models spray impingement on the turbopump dome during the startup process of the preburner of the SSME. (5) Study of the interaction between multiple sprays without and with swirl in their gaseous stream. The spray characteristics of single nozzles were compared with that of three identical nozzles with their axis at a small distance from each other. This study simulates the sprays in the preburner of the SSME, where there are around 260 elements on the faceplate of the combustion chamber. (6) Design an experimental facility to study the characteristics of sprays at high pressure conditions and at supercritical pressure and temperature for the gas but supercritical pressure and subcritical temperature for the liquid.

  6. Modeling, and Experimental Measurements, of the SER Critical Charge (Qcrit) in Scaled, SOI, CMOS Devices

    DTIC Science & Technology

    2014-04-01

    Murray, Michael Gordon, John G. Massey, Kevin Stawiasz and Henry Tang IBM T.J. Watson Research Center P.O. Box 218 Route 134 Yorktown Heights, NY...34 IEEE Transactions on Device and Material Reliablity, vol. 11, no. 4, pp. 551-554, 2011 NSREC 2013 Short Course (Rodbell) IBM TJ Watson Research...upset. P. Oldiges, IBM Figure 1. SOI FinFET inverter modeling (latches) showing good SER immunity. SOI FinFETs should be acceptable for all terrestrial applications. 76

  7. Experimental and Numerical Study of the Influence of Substrate Surface Preparation on Adhesion Mechanisms of Aluminum Cold Spray Coatings on 300M Steel Substrates

    NASA Astrophysics Data System (ADS)

    Nastic, A.; Vijay, M.; Tieu, A.; Rahmati, S.; Jodoin, B.

    2017-07-01

    The effect of substrate surface topography on the creation of metallurgical bonds and mechanical anchoring points has been studied for the cold spray deposition of pure aluminum on 300M steel substrate material. The coatings adhesion strength showed a significant decrease from 31.0 ± 5.7 MPa on polished substrates to 6.9 ± 2.0 MPa for substrates with roughness of 2.2 ± 0.5 μm. Strengths in the vicinity of 45 MPa were reached for coatings deposited onto forced pulsed waterjet treated surfaces with roughnesses larger than 33.8 μm. Finite element analysis has confirmed the sole presence of mechanical anchoring in coating adhesion strength for all surface treatment except polished surfaces. Grit embedment has been shown to be non-detrimental to coating adhesion for the current deposited material combination. The particle deformation process during impacts has been studied through finite element analysis using the Preston-Tonks-Wallace (PTW) constitutive model. The obtained equivalent plastic strain (PEEQ), temperature, contact pressure and velocity vector were correlated to the particle ability to form metallurgical bonds. Favorable conditions for metallurgical bonding were found to be highest for particles deposited on polished substrates, as confirmed by fracture surface analysis.

  8. Experimental and Numerical Study of the Influence of Substrate Surface Preparation on Adhesion Mechanisms of Aluminum Cold Spray Coatings on 300M Steel Substrates

    NASA Astrophysics Data System (ADS)

    Nastic, A.; Vijay, M.; Tieu, A.; Rahmati, S.; Jodoin, B.

    2017-10-01

    The effect of substrate surface topography on the creation of metallurgical bonds and mechanical anchoring points has been studied for the cold spray deposition of pure aluminum on 300M steel substrate material. The coatings adhesion strength showed a significant decrease from 31.0 ± 5.7 MPa on polished substrates to 6.9 ± 2.0 MPa for substrates with roughness of 2.2 ± 0.5 μm. Strengths in the vicinity of 45 MPa were reached for coatings deposited onto forced pulsed waterjet treated surfaces with roughnesses larger than 33.8 μm. Finite element analysis has confirmed the sole presence of mechanical anchoring in coating adhesion strength for all surface treatment except polished surfaces. Grit embedment has been shown to be non-detrimental to coating adhesion for the current deposited material combination. The particle deformation process during impacts has been studied through finite element analysis using the Preston-Tonks-Wallace (PTW) constitutive model. The obtained equivalent plastic strain (PEEQ), temperature, contact pressure and velocity vector were correlated to the particle ability to form metallurgical bonds. Favorable conditions for metallurgical bonding were found to be highest for particles deposited on polished substrates, as confirmed by fracture surface analysis.

  9. An overview of spray drift reduction testing of spray nozzles

    USDA-ARS?s Scientific Manuscript database

    The importance of the development and testing of drift reduction technologies (DRTs) is increasing. Common spray drift reduction technologies include spray nozzles and spray adjuvants. Following draft procedures developed for a DRT program, three spray nozzles were tested under high air speed cond...

  10. A new HVOF thermal spray concept

    SciTech Connect

    Browning, J.A.; Matus, R.J.; Richter, H.J.

    1995-12-31

    HVOF plays an important role in the commercial production of thermal spray coatings from powder. Initially, both the chamber and duct modes were used. Today, the best coatings are produced by high-pressure chamber guns with some manufacturers having switched their designs from the duct to the chamber mode. There has been little or no spraying of wire with HVOF equipment. A new HVOF process -- the shock-stabilized mode -- compliments chamber powder spraying by offering the user a very simple device for wire use. Calculations show that the much higher jet velocities of the chamber mode make that design the better suited for use with powder. Conversely, the greatly increased jet temperatures offered by shock-stabilized combustion give extremely high wire melt-off rates.

  11. Experimental study of gradual/abrupt dynamics of HfO2-based memristive devices

    NASA Astrophysics Data System (ADS)

    Brivio, S.; Covi, E.; Serb, A.; Prodromakis, T.; Fanciulli, M.; Spiga, S.

    2016-09-01

    The resistance switching dynamics of TiN/HfO2/Pt devices is analyzed in this paper. When biased with a voltage ramp of appropriate polarity, the devices experience SET transitions from high to low resistance states in an abrupt manner, which allows identifying a threshold voltage. However, we find that the stimulation with trains of identical pulses at voltages near the threshold results in a gradual SET transition, whereby the resistive state visits a continuum of intermediate levels as it approaches some low resistance state limit. On the contrary, RESET transitions from low to high resistance states proceed in a gradual way under voltage ramp stimulation, while gradual resistance changes driven by trains of identical spikes cover only a limited resistance window. The results are discussed in terms of the relations among the thermo-electrochemical effects of Joule heating, ion mobility, and resistance change, which provide positive and negative closed loop processes in SET and RESET, respectively. Furthermore, the effect of the competition between opposite tendencies of filament dissolution and formation at opposite metal/HfO2 interfaces is discussed as an additional ingredient affecting the switching dynamics.

  12. Experimental Investigation of Turbulent-driven Sheared Parallel Flows in the CSDX Plasma Device

    NASA Astrophysics Data System (ADS)

    Tynan, George; Hong, Rongjie; Li, Jiacong; Thakur, Saikat; Diamond, Patrick

    2016-10-01

    Parallel velocity and its radial shear is a key element for both accessing improved confinement regimes and controlling the impurity transport in tokamak devices. In this study, the development of radially sheared parallel plasma flows in plasmas without magnetic shear is investigated using laser induced fluorescence, multi-tip Langmuir and Mach probes in the CSDX helicon linear plasma device. Results show that a mean parallel velocity shear grows as the radial gradient of plasma density increased. The sheared flow onset corresponds to the onset of a finite parallel Reynolds stress that acts to reinforce the flow. As a result, the mean parallel flow gains energy from the turbulence that, in turn, is driven by the density gradient. This results in a flow away from the plasma source in the central region of the plasma and a reverse flow in far-peripheral region of the plasma column. The results motivate a model of negative viscosity induced by the turbulent stress which may help explain the origin of intrinsic parallel flow in systems without magnetic shear.

  13. Experimental Assessment of Plasma Transport in a 16-cm Multicusp Device

    NASA Astrophysics Data System (ADS)

    Hubble, Aimee; Foster, John

    2012-10-01

    The physics of plasma transport from the bulk plasma through the magnetic cusp to the anode remains poorly understood. A proper accounting of plasma losses to the anode is critical to accurate modeling of multicusp device performance. In this work, plasma transport in a 16-cm multicusp discharge chamber was studied. Each ring was covered with an electrically isolated electrode, which enables the direct measurement of current to each individual ring as well as the discharge chamber wall. A translatable Langmuir probe was used to obtain maps of spatially resolved plasma parameters in bulk plasma region. These maps of spatially resolved plasma density, electron temperature, and plasma potential were compared to current collection at the cusps as well as the magnetic circuit and device performance. Ring electrode measurements coupled with spatially resolved plasma parameter measurements throughout the discharge chamber allow for an assessment of plasma losses to each ring in terms of an ``effective loss area'' which, multiplied by electron current density incident on the bulk/cusp boundary, gives the correct collected current to each ring. A relationship between effective loss area and the physical loss area was determined that can be applied to a 0-D particle and energy balance model.

  14. Field emission device driven by self-powered contact-electrification: Simulation and experimental analysis

    SciTech Connect

    Chen, Xiangyu E-mail: ouyangwei@phy.ecnu.edu.cn; Jiang, Tao; Sun, Zhuo; Ou-Yang, Wei E-mail: ouyangwei@phy.ecnu.edu.cn

    2015-09-14

    A self-powered field emission device (FED) driven by a single-electrode tribo-electric nanogenerator (TENG) is demonstrated. The mechanical motion works as both a power supply to drive the FED and a control unit to regulate the amount of emitted electrons. By using the Fowler-Nordheim equation and Kirchhoff laws, a theoretical model of this self-powered FED is proposed, and accordingly the real-time output characteristics of the device are systematically investigated. It is found that the motion distance of the TENG controls switch-on of the FED and determines the charge amount for emission, while the motion velocity regulates the amplitude of emission current. The minimum contact area for the TENG to generate field emission is about 9 cm{sup 2}, which can be improved by optimizing FED structure and the tribo-materials of TENG. The demonstrated concept of this self-powered FED as well as the proposed physical analysis can serve as guidance for further applications of FED in such fields of self-powered electronics and soft electronics.

  15. An Experimental Study of Radiation-Induced Demagnetization of Insertion Device Permanent Magnets

    SciTech Connect

    Simos,N.; Job, P.K.; Mokhov, N.

    2008-06-23

    High brilliance in the 3GeV new light source NSLS II is obtained from the high magnetic fields in insertion devices (ID). The beam lifetime is limited to 3h by single Coulomb scattering in the Bunch (Touschek effect). This effect occurs everywhere around the circumference and there is unavoidable beam loss in the adjacent low aperture insertion devices. This raises the issue of degradation and damage of the permanent magnetic material by irradiation with high energy electrons and corresponding shower particles. It is expected that IDs, especially those in-vacuum, would experience changes resulting from exposure to gamma rays, x-rays, electrons and neutrons. By expanding an on-going material radiation damage study at BNL the demagnetization effect of irradiation consisting primarily of neutrons, gamma rays and electrons on a set of NdFeB magnets is studied. Integrated doses ranging from several Mrad to a few Grad were achieved at the BNL Isotope Facility with a 112 MeV, 90 {micro}A proton beam. Detailed information on dose distributions as well as on particle energy spectra on the NdFeB magnets was obtained in realistic simulations with the MARS15 Monte-Carlo code. This paper summarizes the results of this study.

  16. Field emission device driven by self-powered contact-electrification: Simulation and experimental analysis

    NASA Astrophysics Data System (ADS)

    Chen, Xiangyu; Jiang, Tao; Sun, Zhuo; Ou-Yang, Wei

    2015-09-01

    A self-powered field emission device (FED) driven by a single-electrode tribo-electric nanogenerator (TENG) is demonstrated. The mechanical motion works as both a power supply to drive the FED and a control unit to regulate the amount of emitted electrons. By using the Fowler-Nordheim equation and Kirchhoff laws, a theoretical model of this self-powered FED is proposed, and accordingly the real-time output characteristics of the device are systematically investigated. It is found that the motion distance of the TENG controls switch-on of the FED and determines the charge amount for emission, while the motion velocity regulates the amplitude of emission current. The minimum contact area for the TENG to generate field emission is about 9 cm2, which can be improved by optimizing FED structure and the tribo-materials of TENG. The demonstrated concept of this self-powered FED as well as the proposed physical analysis can serve as guidance for further applications of FED in such fields of self-powered electronics and soft electronics.

  17. Design of a Microgravity Spray Cooling Experiment

    NASA Technical Reports Server (NTRS)

    Baysinger, Kerri M.; Yerkes, Kirk L.; Michalak, Travis E.; Harris, Richard J.; McQuillen, John

    2004-01-01

    An analytical and experimental study was conducted for the application of spray cooling in a microgravity and high-g environment. Experiments were carried out aboard the NASA KC-135 reduced gravity aircraft, which provided the microgravity and high-g environments. In reduced gravity, surface tension flow was observed around the spray nozzle, due to unconstrained liquid in the test chamber and flow reversal at the heat source. A transient analytical model was developed to predict the temperature and the spray heat transfer coefficient within the heated region. Comparison of the experimental transient temperature variation with analytical results showed good agreement for low heat input values. The transient analysis also verified that thermal equilibrium within the heated region could be reached during the 20-25s reduced gravity portion of the flight profile.

  18. Glass integrated optical wavelength division multiplexing (WDM) devices: a comparison between experimental results and modeling by CAOS software

    NASA Astrophysics Data System (ADS)

    Perrone, Guido; Gulisano, A.; Petazzi, Diego; Macchia, L.; Montrosset, Ivo; Morasca, Salvatore; Pozzi, Fabio; De Bernardi, Carlo S.; Zaffiro, Gianluca

    1994-08-01

    A systematic study on integrated wavelength multi/demultiplexers is presented, in which the experimental features of the devices, the theoretical predictions of a simple model, and the results of extensive modelling by a BPM analysis are compared. The components are based on the two-mode interference principle, and are fabricated on soda-lime glass by Ag-Na ion exchange. The modelling is performed by CAOS, a user-friendly general purpose simulator, based on a FD scheme with transparent boundary conditions. The agreement between experimental and simulated spectral characteristics is very good; moreover the proposed analysis procedure allows the determination of the maximum index variation (Delta) n and the diffusion depth D which describe the optical and geometrical characteristics of the waveguides.

  19. Inhalational and dermal exposures during spray application of biocides.

    PubMed

    Berger-Preiss, Edith; Boehncke, Andrea; Könnecker, Gustav; Mangelsdorf, Inge; Holthenrich, Dagmar; Koch, Wolfgang

    2005-01-01

    Data on inhalational and potential dermal exposures during spray application of liquid biocidal products were generated. On the one hand, model experiments with different spraying devices using fluorescent tracers were carried out to investigate the influence of parameters relevant to the exposure (e.g. spraying equipment, nozzle size, direction of application). On the other hand, measurements were performed at selected workplaces (during disinfection operations in food and feed areas; pest control operations for private, public and veterinary hygiene; wood protection and antifouling applications) after application of biocidal products such as Empire 20, Responsar SC, Omexan-forte, Actellic, Perma-forte; Fendona SC, Pyrethrum mist; CBM 8, Aldekol Des 03, TAD CID, Basileum, Basilit. The measurements taken in the model rooms demonstrated dependence of the inhalation exposure on the type of spraying device used, in the following order: "spraying with low pressure" < "airless spraying" < "fogging" indicating that the particle diameter of the released spray droplets is the most important parameter. In addition inhalation exposure was lowest when the spraying direction was downward. Also for the potential dermal exposure, the spraying direction was of particular importance: overhead spraying caused the highest contamination of body surfaces. The data of inhalational and potential dermal exposures gained through workplace measurements showed considerable variation. During spraying procedures with low-pressure equipments, dose rates of active substances inhaled by the operators ranged from 7 to 230 microg active substance (a.s.)/h. An increase in inhaled dose rates (6-33 mg a.s./h) was observed after use of high application volumes/time unit during wood protection applications indoors. Spraying in the veterinary sector using medium-pressure sprayers led to inhaled dose rates between 2 and 24mga.s./h. The highest inhaled dose rates were measured during fogging (114 mg a

  20. Superficial Automated Keratopigmentation for Iris and Pupil Simulation Using Micronized Mineral Pigments and a New Puncturing Device: Experimental Study.

    PubMed

    Rodriguez, Alejandra E; Amesty, Maria A; El Bahrawy, Mohammed; Rey, Severino; Alio Del Barrio, Jorge; Alio, Jorge L

    2017-09-01

    To study the outcomes and tolerance of micronized mineral pigments for corneal tattooing, using a superficial automated keratopigmentation (SAK) technique in an experimental animal model and a new puncture device to inject the pigments into the corneal stroma. Forty eyes of 40 New Zealand rabbits were included in this study. The animals were divided into groups A and B. Both groups underwent SAK using a new automated keratopigmentation device. Micronized mineral pigments were injected through the epithelium into the corneal stroma to replicate the iris color in 25 eyes (group A), and black color was used to replicate the pupil in 15 eyes (group B). Slit-lamp examination was performed to evaluate the outcome. Histopathological examination was also performed to ascertain the presence of pigment dispersion, inflammation, and/or neovascularization. All 40 eyes showed good cosmetic appearance after keratopigmentation. No intraoperative complications were detected. At the first week, mild or moderated conjunctival injection was observed in 13 eyes and transitory corneal epithelial defects were also detected in 27 eyes. Examination was unremarkable 2, 4, and 6 months after surgery. No neovascularization was detected in any case in the histopathology study. SAK using a new automated puncture device and micronized mineral pigments achieved good cosmetic outcomes for iris and pupil simulation. This method could be a valid alternative to treat serious cosmetic eye problems that affect the superficial cornea or functional problems, such as photophobia or diplopia secondary to iris defects or trauma.

  1. Experimental evaluation of a sEMG-based control for elbow wearable assistive devices during load lifting tasks.

    PubMed

    Meattini, Roberto; Palli, Gianluca; Melchiorri, Claudio

    2017-07-01

    In this work, a surface skin electromyography(sEMG)-based control solution for elbow wearable assistive devices during load lifting tasks is presented. The goal of the controller consists in limiting the user's muscle activity during the task execution, in such a way that the assistive device can partially compensate the load-related biceps muscle effort. Since sEMG-driven control strategies based on the estimation of the joint torques generally requires complex task- and subject-dependent training sessions for tuning the control algorithms, here a more direct control approach is proposed, based on a muscle activity error related proportional-integral action together with an double-threshold activation logic. The controller's parameters are easily set by means of a fast, online and automatic subject calibration procedure, ensuring a simple adjustability to different users. An experimental phase has been conducted in order to evaluate the sEMG-based control performance involving four healthy subjects, using as wearable assistive device a twisted string action module, which is particularly suitable for assistive applications because of its lightness and compactness. Results show that the control strategy is able to successfully limit the EMG activity of the subjects during the lifting tasks, providing preliminary outcomes and promising possibilities for the use of twisted string-based technologies to assist human joints and muscles.

  2. 40 CFR Appendix A to Subpart IIIi... - Determination of Capture Efficiency of Automobile and Light-Duty Truck Spray Booth Emissions From...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... control device. 1.2.2The VOC associated with the overspray coating solids in a controlled spray booth zone... zone, passes through the waterwash and is exhausted from the controlled spray booth zone to the control... through the waterwash, and is exhausted from the controlled spray booth zone to the control device....

  3. 40 CFR Appendix A to Subpart IIIi... - Determination of Capture Efficiency of Automobile and Light-Duty Truck Spray Booth Emissions From...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... control device. 1.2.2The VOC associated with the overspray coating solids in a controlled spray booth zone... zone, passes through the waterwash and is exhausted from the controlled spray booth zone to the control... through the waterwash, and is exhausted from the controlled spray booth zone to the control device....

  4. 40 CFR Appendix A to Subpart IIIi... - Determination of Capture Efficiency of Automobile and Light-Duty Truck Spray Booth Emissions From...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... control device. 1.2.2The VOC associated with the overspray coating solids in a controlled spray booth zone... zone, passes through the waterwash and is exhausted from the controlled spray booth zone to the control... through the waterwash, and is exhausted from the controlled spray booth zone to the control device....

  5. Design and Experimental Verification of Chang'E-3 Moon-night Survival Device for APXS

    NASA Astrophysics Data System (ADS)

    Deng-yi, Chen; Jian, Wu; Yi-ming, Hu; Jin, Chang; Yi-zhong, Gong; Ming-sheng, Cai; Huan-yu, Wang; Jia-yu, Zhang; Xing-zhu, Cui; Jin-zhou, Wang

    2016-07-01

    The Active Particle X-ray Spectrometer (APXS) is one of the 4 scientific payloads of Chang'E-3 (CE-3) Lunar Rover, of which the scientific object is to identify the elements of lunar soil and rock samples by a carried radioactive source to trigger and detect the characteristic X-ray from them. According to the extreme temperature environment of the APXS and under the restriction of limited resources, this paper presents the design and analysis of the moon-night survival device RHU (radioisotope heating unit) for the APXS, and describes the corresponding environmental tests on its structure dynamics and moon-night survival. Finally, its reinstallation on the launch tower and the preliminary result of its on-orbit operation are introduced.

  6. Experimental study on hydrodynamic characteristics of vertical-axis floating tidal current energy power generation device

    NASA Astrophysics Data System (ADS)

    Ma, Yong; Li, Teng-fei; Zhang, Liang; Sheng, Qi-hu; Zhang, Xue-wei; Jiang, Jin

    2016-10-01

    To study the characteristics of attenuation, hydrostatic towage and wave response of the vertical-axis floating tidal current energy power generation device (VAFTCEPGD), a prototype is designed and experiment is carried out in the towing tank. Free decay is conducted to obtain attenuation characteristics of the VAFTCEPGD, and characteristics of mooring forces and motion response, floating condition, especially the lateral displacement of the VAFTCEPGD are obtained from the towing in still water. Tension response of the #1 mooring line and vibration characteristics of the VAFTCEPGD in regular waves as well as in level 4 irregular wave sea state with the current velocity of 0.6 m/s. The results can be reference for theoretical study and engineering applications related to VAFTCEPGD.

  7. Experimental investigation of aerodynamic devices for wind turbine rotational speed control. Phase 1

    SciTech Connect

    Miller, L.S.

    1995-02-01

    An investigation was undertaken to identify the aerodynamic performance of five separate trailing-edge control devices, and to evaluate their potential for wind turbine overspeed and power modulation applications. A modular two-dimensional wind tunnel model was constructed and evaluated during extensive wind tunnel testing. Aerodynamic lift, drag, suction, and pressure coefficient data were acquired and analyzed for various control configurations and angles of attack. To further interpret their potential performance, the controls were evaluated numerically using a generic wind turbine geometry and a performance analysis computer program. Results indicated that the Spoiler-Flap control configuration was best softed for turbine braking applications. It exhibited a large negative suction coefficient over a broad angle-of-attack range, and good turbine braking capabilities, especially at low tip-speed ratio.

  8. Experimental validation of superconducting quantum interference device sensors for electromagnetic scattering in geologic structures

    SciTech Connect

    Krauss, R.H. Jr.; Flynn, E.; Ruminer, P.

    1997-10-01

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). This project has supported the collaborative development with Sandia National Laboratories (SNL) and the University of New Mexico (UNM) of two critical components for a hand-held low-field magnetic sensor based on superconducting quantum interference device (SQUID) sensor technology. The two components are a digital signal processing (DSP) algorithm for background noise rejection and a small hand-held dewar cooled by a cryocooler. A hand-held sensor has been designed and fabricated for detection of extremely weak magnetic fields in unshielded environments. The sensor is capable of measuring weak magnetic fields in unshielded environments and has multiple applications. We have chosen to pursue battlefield medicine as the highest probability near-term application because of stated needs of several agencies.

  9. The Effect of Variable Gravity on the Cooling Performance of a 16-Nozzle Spray Array

    DTIC Science & Technology

    2008-09-01

    exceptional versatility in which many parameters can be adjusted to fit the needs of the application. Spray cooling is con- sidered one of the most effective...are two types of spray cooling: Pressure atomized and vapor atomized. In a pressure atomized spray cooling system, liquid is pumped through a spray...recirculating flow loop that pumped fluid using a pressurized syringe of liquid. Experimental difficulties arose during flight testing that restricted the amount

  10. Experimental study on the optimization of general conditions for a free-flow electrophoresis device with a thermoelectric cooler.

    PubMed

    Yan, Jian; Yang, Cheng-Zhang; Zhang, Qiang; Liu, Xiao-Ping; Kong, Fan-Zhi; Cao, Cheng-Xi; Jin, Xin-Qiao

    2014-12-01

    With a given free-flow electrophoresis device, reasonable conditions (electric field strength, carrier buffer conductivity, and flow rate) are crucial for an optimized separation. However, there has been no experimental study on how to choose reasonable general conditions for a free-flow electrophoresis device with a thermoelectric cooler in view of Joule heat generation. Herein, comparative experiments were carried out to propose the selection procedure of general conditions in this study. The experimental results demonstrated that appropriate conditions were (i) <67 V/cm electric field strength; (ii) lower than 1.3 mS/cm carrier buffer conductivity (Tris-HCl: 20 mM Tris was titrated by HCl to pH 8.0); and (iii) higher than 3.6 mL/min carrier buffer flow rate. Furthermore, under inappropriate conditions (e.g. 400 V voltage and 40 mM Tris-HCl carrier buffer), the free-flow electrophoresis separation would be destroyed by bubbles caused by more Joule heating. Additionally, a series of applications under the appropriate conditions were performed with samples of model dyes, proteins (bovine serum albumin, myoglobin, and cytochrome c), and cells (Escherichia coli, Streptococcus thermophilus, and Saccharomyces cerevisiae). The separation results showed that under the appropriate conditions, separation efficiency was obviously better than that in the previous experiments with randomly or empirically selected conditions.

  11. Quality risk management of top spray fluidized bed process for antihypertensive drug formulation with control strategy engendered by Box-behnken experimental design space

    PubMed Central

    Mukharya, Amit; Patel, Paresh U; Shenoy, Dinesh; Chaudhary, Shivang

    2013-01-01

    Introduction: Lacidipine (LCDP) is a very low soluble and highly biovariable calcium channel blocker used in the treatment of hypertension. To increase its apparent solubility and to reduce its biovariability, solid dispersion fluid bed processing technology was explored, as it produces highly dispersible granules with a characteristic porous structure that enhances dispersibility, wettability, blend uniformity (by dissolving and spraying a solution of actives), flow ability and compressibility of granules for tableting and reducing variability by uniform drug-binder solution distribution on carrier molecules. Materials and Methods: Main object of this quality risk management (QRM) study is to provide a sophisticated “robust and rugged” Fluidized Bed Process (FBP) for the preparation of LCDP tablets with desired quality (stability) and performance (dissolution) by quality by design (QbD) concept. Results and Conclusion: This study is principally focusing on thorough mechanistic understanding of the FBP by which it is developed and scaled up with a knowledge of the critical risks involved in manufacturing process analyzed by risk assessment tools like: Qualitative Initial Risk-based Matrix Analysis (IRMA) and Quantitative Failure Mode Effective Analysis (FMEA) to identify and rank parameters with potential to have an impact on In Process/Finished Product Critical Quality Attributes (IP/FP CQAs). These Critical Process Parameters (CPPs) were further refined by DoE and MVDA to develop design space with Real Time Release Testing (RTRT) that leads to implementation of a control strategy to achieve consistent finished product quality at lab scale itself to prevent possible product failure at larger manufacturing scale. PMID:23799202

  12. An experimentally verified model for thermal microactuators including nonlinear material properties, vacuum, and intra-device heat conduction

    NASA Astrophysics Data System (ADS)

    Colbert, Keegan; Naraghi, Mohammad; Boyd, James G.

    2017-02-01

    This paper presents a model and computational method to predict the steady-state performance of thermal flexure microactuators at high input powers and various levels of partial vacuum. The model accounts for nonlinear temperature dependence of material properties, heat loss due to radiation, and intra-device heat transfer by conduction across an air gap. The model is validated by comparing the model predictions with the experimentally measured voltage, current, and displacement at standard conditions, prior to adjusting for partial vacuum. In order to understand the effect of nonlinearities on model reliability, the predictions of six additional hypothetical models are considered where (1) intra-device heat transfer is neglected, (2) radiation is neglected, (3) the thermal conductivity of silicon is assumed to be temperature-independent, (4) the thermal conductivity of air is assumed to be temperature-independent, (5) the electrical resistivity of silicon is assumed to be linear in temperature, and (6) the thermal expansion coefficient of silicon is assumed to be temperature-independent. All factors except radiation were shown to have a significant influence on the device performance especially at high input powers. The experimentally validated full model is then employed to predict the effect of reduced air pressure on the displacement and heat transfer properties of the actuator. This aspect of the study targets applications of thermal actuators in controlled environments such as space applications, actuators used for in situ micropositioning and tensile testing inside electron microscopy chambers, or actuators incorporated into the design of MEMS resonators. It was demonstrated that the maximum actuator displacement is not a linear function of reduced pressure and that it reaches a maximum at a certain partial vacuum level.

  13. Variable friction device for structural control based on duo-servo vehicle brake: Modeling and experimental validation

    NASA Astrophysics Data System (ADS)

    Cao, Liang; Downey, Austin; Laflamme, Simon; Taylor, Douglas; Ricles, James

    2015-07-01

    Supplemental damping can be used as a cost-effective method to reduce structural vibrations. In particular, passive systems are now widely accepted and have numerous applications in the field. However, they are typically tuned to specific excitations and their performances are bandwidth-limited. A solution is to use semi-active devices, which have shown to be capable of substantially enhanced mitigation performance. The authors have recently proposed a new type of semi-active device, which consists of a variable friction mechanism based on a vehicle duo-servo drum brake, a mechanically robust and reliable technology. The theoretical performance of the proposed device has been previously demonstrated via numerical simulations. In this paper, we further the understanding of the device, termed Modified Friction Device (MFD) by fabricating a small scale prototype and characterizing its dynamic behavior. While the dynamics of friction is well understood for automotive braking technology, we investigate for the first time the dynamic behavior of this friction mechanism at low displacements and velocities, in both forward and backward directions, under various hydraulic pressures. A modified 3-stage dynamic model is introduced. A LuGre friction model is used to characterize the friction zone (Stage 1), and two pure stiffness regions to characterize the dynamics of the MFD once the rotation is reversed and the braking shoes are sticking to the drum (Stage 2) and the rapid build up of forces once the shoes are held by the anchor pin (Stage 3). The proposed model is identified experimentally by subjecting the prototype to harmonic excitations. It is found that the proposed model can be used to characterize the dynamics of the MFD, and that the largest fitting error arises at low velocity under low pressure input. The model is then verified by subjecting the MFD to two different earthquake excitations under different pressure inputs. The model is capable of tracking the

  14. Chlorfenapyr (A Pyrrole Insecticide) Applied Alone or as a Mixture with Alpha-Cypermethrin for Indoor Residual Spraying against Pyrethroid Resistant Anopheles gambiae sl: An Experimental Hut Study in Cove, Benin

    PubMed Central

    Ngufor, Corine; Critchley, Jessica; Fagbohoun, Josias; N’Guessan, Raphael; Todjinou, Damien; Rowland, Mark

    2016-01-01

    Background Indoor spraying of walls and ceilings with residual insecticide remains a primary method of malaria control. Insecticide resistance in malaria vectors is a growing problem. Novel insecticides for indoor residual spraying (IRS) which can improve the control of pyrethroid resistant malaria vectors are urgently needed. Insecticide mixtures have the potential to improve efficacy or even to manage resistance in some situations but this possibility remains underexplored experimentally. Chlorfenapyr is a novel pyrrole insecticide which has shown potential to improve the control of mosquitoes which are resistant to current WHO-approved insecticides. Method The efficacy of IRS with chlorfenapyr applied alone or as a mixture with alpha-cypermeththrin (a pyrethroid) was evaluated in experimental huts in Cove, Southern Benin against wild free flying pyrethroid resistant Anopheles gambiae sl. Comparison was made with IRS with alpha-cypermethrin alone. Fortnightly 30-minute in situ cone bioassays were performed to assess the residual efficacy of the insecticides on the treated hut walls. Results Survival rates of wild An gambiae from the Cove hut site in WHO resistance bioassays performed during the trial were >90% with permethrin and deltamethrin treated papers. Mortality of free-flying mosquitoes entering the experimental huts was 4% in the control hut. Mortality with alpha-cypermethrin IRS did not differ from the control (5%, P>0.656). The highest mortality was achieved with chlorfenapyr alone (63%). The alpha-cypermethrin + chlorfenapyr mixture killed fewer mosquitoes than chlorfenapyr alone (43% vs. 63%, P<0.001). While the cone bioassays showed a more rapid decline in residual mortality with chlorfenapyr IRS to <30% after only 2 weeks, fortnightly mortality rates of wild free-flying An gambiae entering the chlorfenapyr IRS huts were consistently high (50–70%) and prolonged, lasting over 4 months. Conclusion IRS with chlorfenapyr shows potential to

  15. Evaluation of the efficacy of DDT indoor residual spraying and long-lasting insecticidal nets against insecticide resistant populations of Anopheles arabiensis Patton (Diptera: Culicidae) from Ethiopia using experimental huts

    PubMed Central

    2014-01-01

    Background Indoor Residual Spraying (IRS) and Long-Lasting Insecticidal nets (LLINs) are major malaria vector control tools in Ethiopia. However, recent reports from different parts of the country showed that populations of Anopheles arabiensis, the principal malaria vector, have developed resistance to most families of insecticides recommended for public health use which may compromise the efficacy of both of these key vector control interventions. Thus, this study evaluated the efficacy of DDT IRS and LLINs against resistant populations of An. arabiensis using experimental huts in Asendabo area, southwestern Ethiopia. Methods The susceptibility status of populations of An. arabiensis was assessed using WHO test kits to DDT, deltamethrin, malathion, lambda-cyhalothrin, fenitrothion and bendiocarb. The efficacy of LLIN (PermaNet® 2.0), was evaluated using the WHO cone bioassay. Moreover, the effect of the observed resistance against malaria vector control interventions (DDT IRS and LLINs) were assessed using experimental huts. Results The findings of this study revealed that populations of An. arabiensis were resistant to DDT, deltamethrin, lambda-cyhalothrin and malathion with mortality rates of 1.3%, 18.8%, 36.3% and 72.5%, respectively but susceptible to fenitrothion and bendiocarb with mortality rates of 98.81% and 97.5%, respectively. The bio-efficacy test of LLIN (PermaNet® 2.0) against An. arabiensis revealed that the mosquito population showed moderate knockdown (64%) and mortality (78%). Moreover, mosquito mortalities in DDT sprayed huts and in huts with LLINs were not significantly different (p > 0.05) from their respective controls. Conclusion The evaluation of the efficacy of DDT IRS and LLINs using experimental huts showed that both vector control tools had only low to moderate efficacy against An. arabiensis populations from Ethiopia. Despite DDT being replaced by carbamates for IRS, the low efficacy of LLINs against the resistant population of An

  16. Chlorfenapyr (A Pyrrole Insecticide) Applied Alone or as a Mixture with Alpha-Cypermethrin for Indoor Residual Spraying against Pyrethroid Resistant Anopheles gambiae sl: An Experimental Hut Study in Cove, Benin.

    PubMed

    Ngufor, Corine; Critchley, Jessica; Fagbohoun, Josias; N'Guessan, Raphael; Todjinou, Damien; Rowland, Mark

    2016-01-01

    Indoor spraying of walls and ceilings with residual insecticide remains a primary method of malaria control. Insecticide resistance in malaria vectors is a growing problem. Novel insecticides for indoor residual spraying (IRS) which can improve the control of pyrethroid resistant malaria vectors are urgently needed. Insecticide mixtures have the potential to improve efficacy or even to manage resistance in some situations but this possibility remains underexplored experimentally. Chlorfenapyr is a novel pyrrole insecticide which has shown potential to improve the control of mosquitoes which are resistant to current WHO-approved insecticides. The efficacy of IRS with chlorfenapyr applied alone or as a mixture with alpha-cypermeththrin (a pyrethroid) was evaluated in experimental huts in Cove, Southern Benin against wild free flying pyrethroid resistant Anopheles gambiae sl. Comparison was made with IRS with alpha-cypermethrin alone. Fortnightly 30-minute in situ cone bioassays were performed to assess the residual efficacy of the insecticides on the treated hut walls. Survival rates of wild An gambiae from the Cove hut site in WHO resistance bioassays performed during the trial were >90% with permethrin and deltamethrin treated papers. Mortality of free-flying mosquitoes entering the experimental huts was 4% in the control hut. Mortality with alpha-cypermethrin IRS did not differ from the control (5%, P>0.656). The highest mortality was achieved with chlorfenapyr alone (63%). The alpha-cypermethrin + chlorfenapyr mixture killed fewer mosquitoes than chlorfenapyr alone (43% vs. 63%, P<0.001). While the cone bioassays showed a more rapid decline in residual mortality with chlorfenapyr IRS to <30% after only 2 weeks, fortnightly mortality rates of wild free-flying An gambiae entering the chlorfenapyr IRS huts were consistently high (50-70%) and prolonged, lasting over 4 months. IRS with chlorfenapyr shows potential to significantly improve the control of malaria

  17. Experimental testing of a new left ventricular assist device--the microdiagonal blood pump.

    PubMed

    Christiansen, Stefan; Demircan, Lütfü; Kwant, Paul B; Akdis, Mustafa; Rex, Steffen; Buhre, Wolfgang; Langebartels, Georg; Kuruc, Norbert; Nikolin, Stefan; Reul, Helmut; Autschbach, Rüdiger

    2004-01-01

    All existing ventricular assist devices are associated with a considerable number of serious complications. This article reports on the first animal tests with a newly developed microdiagonal blood pump (MDP). Six adult female sheep weighing 80 to 90 kg underwent implantation of the microdiagonal blood pump. The inflow and outflow conduits were anastomosed to the left atrium and the descending aorta. Pump flow was adjusted to 2-3 L/minute. Hemodynamic and echocardiographic data, as well as blood samples, were measured over the entire test period of 7 days. All internal organs and the pump were explanted for thorough examination at the end of the trial. Mean arterial (range 88.5 +/- 13.1-103.7 +/- 10.7 mm Hg) and mean pulmonary arterial (18.3 +/- 2.7-21.6 +/- 20.5 mm Hg) pressures, as well as the pulmonary capillary wedge pressure (14.2 +/- 3.0 - 16.6 +/- 4.0 mm Hg), remained stable during the whole test period. Cardiac output (4.9 +/- 0.7 --> 3.2 +/- 0.5 L/minute) decreased postoperatively caused by partial unloading of the heart. Left ventricular end diastolic (4.1 +/- 0.5 --> 3.6 +/- 0.3 cm) and end systolic (3.2 +/- 0.4 --> 2.8 +/- 0.5 cm) diameters, as well as the ejection fraction (57 +/- 9 --> 42 +/- 5%), decreased after MDP implantation and did not change during the test period. Mean number of platelets (428 +/- 54 --> 286 +/- 66 x 10(3)/microL) and hemoglobin (9.8 +/- 1.3 --> 6.3 +/- 0.8 g/dL) decreased perioperatively because of surgical reasons and increased continuously in the postoperative course (platelet count and hemoglobin on day 7:441 +/- 74 x 10(3)/microL and 7.2 +/- 1.1 g/dL, respectively). Free hemoglobin was not enhanced in the postoperative course (mean value during the test period: 18.8 mmoL/L). Histologic examination of the organs did not demonstrate any infarctions of internal organs other than typical operative sequelae such as chronic pericarditis and some degree of atelectasis of the left lungs. These results demonstrate that the

  18. Computational, Experimental and Engineering Foundations of Ionic Channels as Miniaturized Sensors, Devices and Systems

    DTIC Science & Technology

    2003-10-01

    strated experimentally that the channel is functionally closed at pH 7 and is fully open at pH 4 ( Cuello et al., 1998; Heginbotham et al., 1999). The...reasonable agreement with exper- imentally determined maximal conductances of 90 pS (Schrempf et al., 1995) and 135 pS at 200 mM K ( Cuello et al...porins. Nature. 358:727–733. Cuello , L. G., J. G. Romero, D. M. Cortes, and E. Perozo. 1998. pH- dependent gating in the Streptomyces lividans K

  19. Analytical and experimental evaluation of techniques for the fabrication of thermoplastic hologram storage devices

    NASA Technical Reports Server (NTRS)

    Rogers, J. W.

    1975-01-01

    The results of an experimental investigation on recording information on thermoplastic are given. A description was given of a typical fabrication configuration, the recording sequence, and the samples which were examined. There are basically three configurations which can be used for the recording of information on thermoplastic. The most popular technique uses corona which furnishes free charge. The necessary energy for deformation is derived from a charge layer atop the thermoplastic. The other two techniques simply use a dc potential in place of the corona for deformation energy.

  20. Influence of spraying distance and postcooling on cryogen spray cooling for dermatologic laser surgery

    NASA Astrophysics Data System (ADS)

    Aguilar, Guillermo; Majaron, Boris; Viator, John A.; Basinger, Brooke; Karapetian, Emil; Svaasand, Lars O.; Lavernia, Enrique J.; Nelson, J. Stuart

    2001-05-01

    Cryogen spray cooling (CSC) is used to minimize the risk of epidermal damage in various laser dermatological procedures such as treatment of port wine stain birthmarks and hair removal. However, the spray characteristics and combination of CSC and heating (laser) to obtain optimal treatments have not yet been determined. The distance between the nozzle tip and the skin surface for commercial devices was apparently chosen based on the position at which the cryogen spray reached a minimum temperature, presumably with the expectation that such a minimum would correspond to maximal heat flux. We have systematically measured spray characteristics of various nozzles, such as mean droplet diameter, velocity, temperature, and heat transfer coefficient, as a function of distance from the nozzle tip. Among other interesting correlations between these spray characteristics, it is shown that, for nozzle-to-skin distances between 20 to 80 mm, variations in the heat transfer coefficient are larger than those in the spray temperature and, therefore, maximization of the heat flux should be better dictated by the distance at which the heat transfer coefficient is maximized rather than that at which the spray temperature is minimized. Also, the influence of droplet diameter appears to be more influential on the heat transfer coefficient value than that of droplet velocity. Based on spray characteristic correlations, different ranges for positioning the nozzles are recommended, depending on the clinical application. Also, a 2D finite-difference method has been developed to study the spatial and temporal thermal variations within the skin. Our results show that it is possible to decrease significantly the epidermal damage after laser irradiation provided the heat transfer coefficient is significantly increased. The influence of post-cooling has minimal effects for the cases studied.

  1. Design and Experimental Investigation of a Compact Circularly Polarized Integrated Filtering Antenna for Wearable Biotelemetric Devices.

    PubMed

    Jiang, Zhi Hao; Gregory, Micah D; Werner, Douglas H

    2016-04-01

    A compact circularly polarized (CP) integrated filtering antenna is reported for wearable biotelemetric devices in the 2.4 GHz ISM band. The design is based on a mutual synthesis of a CP patch antenna connected to a bandpass filter composed of coupled stripline open-loop resonators, which provides an integrated low-profile radiating and filtering module with a compact form factor of 0.44λ(0)×0.44λ(0)×0.04λ(0). The optimized filtering antenna is fabricated and measured, achieving an S11 < -14 dB, an axial ratio of less than 3 dB and gain higher than 3.5 dBi in the targeted ISM band. With the integrated filtering functionality, the antenna exhibits good out-of-band rejection over an ultra-wide frequency range of 1-6 GHz. Further full-wave simulations and experiments were carried out, verifying that the proposed filtering antenna maintains these desirable properties even when mounted in close proximity to the human body at different positions. The stable impedance performance and the simultaneous wide axial ratio and radiated power beam widths make it an ideal candidate as a wearable antenna for off-body communications. The additional integrated filtering functionality further improves utility by greatly reducing interference and crosstalk with other existing wireless systems.

  2. Theoretical and experimental study of flow-control devices for inlets of indraft wind tunnels

    NASA Technical Reports Server (NTRS)

    Ross, James C.

    1989-01-01

    The design of closed circuit wind tunnels has historically been performed using rule of thumb which have evolved over the years into a body of useful guidelines. The development of indraft wind tunnels, however, has not been as well documented. The design of indraft wind tunnels is therefore generally performed using a more intuitive approach, often resulting in a facility with disappointing flow quality. The primary problem is a lack of understanding of the flow in the inlet as it passes through the required antiturbulence treatment. For wind tunnels which employ large contraction ratio inlets, this lack of understanding is not serious since the relatively low velocity of the flow through the inlet treatment reduces the sensitivity to improper inlet design. When designing a small contraction ratio inlet, much more careful design is needed in order to reduce the flow distortions generated by the inlet treatment. As part of the National Full Scale Aerodynamics Complex Modification Project, 2-D computational methods were developed which account for the effect of both inlet screens and guide vanes on the test section velocity distribution. Comparisons with experimental data are presented which indicate that the methods accurately compute the flow distortions generated by a screen in a nonuniform velocity field. The use of inlet guide vanes to eliminate the screen induced distortion is also demonstrated both computationally and experimentally. Extensions of the results to 3-D is demonstrated and a successful wind tunnel design is presented.

  3. Nonlinear dynamics in experimental devices with compressed/expanded surfactant monolayers

    NASA Astrophysics Data System (ADS)

    Higuera, M.; Perales, J. M.; Vega, J. M.

    2014-08-01

    A theory is provided for a common experimental set up that is used to measure surface properties in surfactant monolayers. The set up consists of a surfactant monolayer (over a shallow liquid layer) that is compressed/expanded in a periodic fashion by moving in counter-phase two parallel, slightly immersed solid barriers, which vary the free surface area and thus the surfactant concentration. The simplest theory ignores the fluid dynamics in the bulk fluid, assuming spatially uniform surfactant concentration, which requires quite small forcing frequencies and provides reversible dynamics in the compression/expansion cycles. In this paper, we present a long-wave theory for not so slow oscillations that assumes local equilibrium but takes the fluid dynamics into account. This simple theory uncovers the physical mechanisms involved in the surfactant behavior and allows for extracting more information from each experimental run. The conclusion is that the fluid dynamics cannot be ignored, and that some irreversible dynamics could well have a fluid dynamic origin.

  4. Nasal corticosteroid sprays

    MedlinePlus

    ... best for decreasing symptoms during that season. Several brands of nasal corticosteroid sprays are available. They all ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

  5. Budesonide Nasal Spray

    MedlinePlus

    ... by an allergy to pollen, mold, dust, or pets). Budesonide nasal spray should not be used to ... disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, ...

  6. Fluticasone Nasal Spray

    MedlinePlus

    ... the pump until you see a fine spray. Blow your nose until your nostrils are clear. Hold ... chills, cough, and other signs of infection whistling sound from the nose hives rash itching swelling of ...

  7. Supersonic-Spray Cleaner

    NASA Technical Reports Server (NTRS)

    Caimi, Raoul E. B.; Lin, Feng-Nan; Thaxton, Eric A.

    1995-01-01

    Spraying system for cleaning mechanical components uses less liquid and operates at pressures significantly lower. Liquid currently used is water. Designed to replace chlorofluorocarbon (CFC) solvent-based cleaning and cleanliness verification methods. Consists of spray head containing supersonic converging/diverging nozzles, source of gas at regulated pressure, pressurized liquid tank, and various hoses, fittings, valves, and gauges. Parameters of nozzles set so any of large variety of liquids and gases combined in desired ratio and rate of flow. Size and number of nozzles varied so system built in configurations ranging from small hand-held spray heads to large multinozzle cleaners. Also used to verify part adequately cleaned. Runoff liquid from spray directed at part collected. Liquid analyzed for presence of contaminants, and part recleaned if necessary.

  8. Beclomethasone Nasal Spray

    MedlinePlus

    ... the lining of the nose) after nasal polyp removal surgery. Beclomethasone nasal spray should not be used ... room temperature and away from excess heat and moisture (not in the bathroom).Unneeded medications should be ...

  9. Ciclesonide Nasal Spray

    MedlinePlus

    ... runny or itchy nose. Ciclesonide is in a class of medications called corticosteroids. It works by preventing ... hold the bottle firmly with your forefinger and middle finger on either side of the spray tip ...

  10. Flunisolide Nasal Spray

    MedlinePlus

    ... by the common cold. It is in a class of medications called corticosteroids. It works by blocking ... spray with the applicator between your forefinger and middle finger and the bottom of the bottle resting ...

  11. Nicotine Nasal Spray

    MedlinePlus

    ... the bottle in front of a tissue or paper towel. Pump the spray bottle six to eight times ... up the spill immediately with a cloth or paper towel. Avoid touching the liquid. Throw away the used ...

  12. The use of polyethylene intramammary device in protection of the lactating bovine udder against experimental infection with Staphylococcus aureus or Streptococcus agalactiae.

    PubMed Central

    Brooks, B W; Barnum, D A

    1982-01-01

    The susceptibility of lactating bovine udder quarters fitted with a polyethylene intramammary device to infection was investigated. Following experimental challenge with Streptococcus agalactiae or Staphylococcus aureus, the incidence of infection was significantly (p less than 0.05) lower in intramammary device-fitted quarters compared to control quarters. In general, total foremilk and strippings milk somatic cell counts for intramammary device-fitted and control quarters were not significantly (p less than 0.05) different. Differential foremilk and strippings milk somatic cell counts were significantly (p less than 0.05) higher in samples from intramammary device-fitted quarters compared to control quarters. PMID:7127192

  13. Sensors in Spray Processes

    NASA Astrophysics Data System (ADS)

    Fauchais, P.; Vardelle, M.

    2010-06-01

    This paper presents what is our actual knowledge about sensors, used in the harsh environment of spray booths, to improve the reproducibility and reliability of coatings sprayed with hot or cold gases. First are described, with their limitations and precisions, the different sensors following the in-flight hot particle parameters (trajectories, temperatures, velocities, sizes, and shapes). A few comments are also made about techniques, still under developments in laboratories, to improve our understanding of coating formation such as plasma jet temperature measurements in non-symmetrical conditions, hot gases heat flux, particles flattening and splats formation, particles evaporation. Then are described the illumination techniques by laser flash of either cold particles (those injected in hot gases, or in cold spray gun) or liquid injected into hot gases (suspensions or solutions). The possibilities they open to determine the flux and velocities of cold particles or visualize liquid penetration in the core of hot gases are discussed. Afterwards are presented sensors to follow, when spraying hot particles, substrate and coating temperature evolution, and the stress development within coatings during the spray process as well as the coating thickness. The different uses of these sensors are then described with successively: (i) Measurements limited to particle trajectories, velocities, temperatures, and sizes in different spray conditions: plasma (including transient conditions due to arc root fluctuations in d.c. plasma jets), HVOF, wire arc, cold spray. Afterwards are discussed how such sensor data can be used to achieve a better understanding of the different spray processes, compare experiments to calculations and improve the reproducibility and reliability of the spray conditions. (ii) Coatings monitoring through in-flight measurements coupled with those devoted to coatings formation. This is achieved by either maintaining at their set point both in-flight and

  14. Measurement Of Water Sprays Generated By Airplane Tires

    NASA Technical Reports Server (NTRS)

    Daugherty, Robert H.; Stubbs, Sandy M.

    1990-01-01

    Experimental investigation conducted at NASA Langley Research Center to measure rate of flow and trajectory of water spray generated by tire operating on flooded runway. Potential application to both aircraft and automotive industries, with particular application to manufacturers of tires.

  15. Spray applicator for spraying coatings and other fluids in space

    NASA Technical Reports Server (NTRS)

    Kuminecz, J. F.; Lausten, M. F. (Inventor)

    1985-01-01

    A self contained spray application is developed for one handed operation in a zero gravity vacuum environment by a free flying astronaut not attached to any spacecraft. This spray applicator eliminates contamination of the operator by back spray. This applicator includes a rigid accumulator containment of a fluid within a flexible bladder the fluid being urged out of the accumulator under pressure through a spray gun. The spray gun includes a spring loaded lockable trigger which controls a valve. When in an open position, the fluid passes through the valve into the ambient environment in the form of a spray. A spray shield is provided which directs the flow of the spray from the applicator by trapping errant particles of spray yet allowing the passage of escaping gases through its material.

  16. Directed spray mast

    DOEpatents

    Nance, Thomas A.; Siddall, Alvin A.; Cheng, William Y.; Counts, Kevin T.

    2005-05-10

    Disclosed is an elongated, tubular, compact high pressure sprayer apparatus for insertion into an access port of vessels having contaminated interior areas that require cleaning by high pressure water spray. The invention includes a spray nozzle and a camera adjacent thereto with means for rotating and raising and lowering the nozzle so that areas identified through the camera may be cleaned with a minimum production of waste water to be removed.

  17. Metal atomization spray nozzle

    DOEpatents

    Huxford, Theodore J.

    1993-01-01

    A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal.

  18. Portable Spray Booth

    NASA Technical Reports Server (NTRS)

    Hansen, Timothy D.; Bardwell, Micheal J.

    1996-01-01

    Portable spray booth provides for controlled application of coating materials with high solvent contents. Includes contoured shroud and carbon filter bed limiting concentration of fumes in vicinity. Designed to substitute spraying for brush application of solvent-based adhesive prior to installing rubber waterproof seals over joints between segments of solid-fuel rocket motor. With minor adjustments and modifications, used to apply other solvent-based adhesives, paints, and like.

  19. Portable Spray Booth

    NASA Technical Reports Server (NTRS)

    Hansen, Timothy D.; Bardwell, Micheal J.

    1996-01-01

    Portable spray booth provides for controlled application of coating materials with high solvent contents. Includes contoured shroud and carbon filter bed limiting concentration of fumes in vicinity. Designed to substitute spraying for brush application of solvent-based adhesive prior to installing rubber waterproof seals over joints between segments of solid-fuel rocket motor. With minor adjustments and modifications, used to apply other solvent-based adhesives, paints, and like.

  20. Metal atomization spray nozzle

    DOEpatents

    Huxford, T.J.

    1993-11-16

    A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal. 6 figures.

  1. Experimental Characterization of the Electric Field Distribution Induced by TMS Devices.

    PubMed

    Nieminen, Jaakko O; Koponen, Lari M; Ilmoniemi, Risto J

    2015-01-01

    In transcranial magnetic stimulation (TMS) a strong, brief current pulse driven through a coil is used for non-invasively stimulating the cortex. Properties of the electric field (E-field) induced by the pulse together with physiological parameters determine the outcome of the stimulation. In research and clinical use, TMS is delivered using a wide range of different coils and stimulator units, all having their own characteristics; however, the parameters of the induced E-field are often inadequately known by the user. To better understand how the use of a specific TMS device may affect the resulting cortical stimulation, our objective was to develop an instrument for automated measurement of the E-fields induced by TMS coils in spherically symmetric conductors approximating the head. We built a saline-free, robotized measurement tool based on the triangle construction. The 5-mm-wide measurement probe allows complete sampling of the induced E-field at the studied depth. We used the instrument to characterize TMS coils and stimulators made by two companies. The measurements revealed that all tested stimulators performed as expected, but we also found significant differences between the different stimulators. Measurements of different coil specimens of the same stimulator models agreed with each other. The presented TMS calibrator allows a straightforward characterization of the E-fields induced by TMS coils. By performing measurements using this kind of a tool helps in ensuring that an investigator knows the properties of the E-field. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Advanced spray generator of singlet oxygen

    NASA Astrophysics Data System (ADS)

    Spalek, Otomar; Hrubý, Jan; Jirásek, Vít; Čenský, Miroslav; Kodymová, Jarmila; Picková, Irena

    2007-05-01

    A spray type singlet oxygen generator (SOG) for chemical oxygen-iodine laser (COIL) was studied. Mathematical modeling has shown that a high O II(1Δ) yield can be attained with BHP (basic hydrogen peroxide) spray in the Cl II-He atmosphere. It was found experimentally that O II(1Δ) was produced with a >=50% yield at a total pressure up to 50 kPa (375 Torr). A rotating separator was developed that can segregate even very small droplets (>=0.5 μm) from O II(1Δ) flow.

  3. Spray Rolling Aluminum Strip for Transportation Applications

    SciTech Connect

    Kevin M. McHugh; Y. Lin; Y. Zhou; E. J. Lavernia; J.-P. Delplanque; S. B. Johnson

    2005-02-01

    Spray rolling is a novel strip casting technology in which molten aluminum alloy is atomized and deposited into the roll gap of mill rolls to produce aluminum strip. A combined experimental/modeling approach has been followed in developing this technology with active participation from industry. The feasibility of this technology has been demonstrated at the laboratory scale and it is currently being scaled-up. This paper provides an overview of the process and compares the microstructure and properties of spray-rolled 2124 aluminum alloy with commercial ingot-processed material

  4. Spraying Respiratory Epithelial Cells to Coat Tissue-Engineered Constructs

    PubMed Central

    Thiebes, Anja Lena; Albers, Stefanie; Klopsch, Christian; Jockenhoevel, Stefan; Cornelissen, Christian G.

    2015-01-01

    Abstract Applying cells in a spray can overcome current hurdles in coating tissue engineered constructs with a thin layer of endo- or epithelial cells. We report here a structured study on the influences of spray application with a medical spray device on vascular smooth muscle cells (vSMCs) and respiratory epithelial cells (RECs) with and without fibrin gel. Next to viability and cytotoxicity assays, the in vitro differentiation capacity after spray processing was analyzed. For vSMC, no influence of air pressures till 0.8 bar could be shown, whereas the viability decreased for higher pressures. The viability of RECs was reduced to 88.5% with 0.4 bar air pressure. Lactate dehydrogenase-levels in the culture medium increased the first day after spraying but normalized afterward. In the short term, no differences by means of morphology and expression-specific markers for vSMCs and RECs were seen between the control and study group. In addition, in a long-term study for 28 days with the air–liquid interface, RECs differentiated and built up an organized epithelial layer with ciliary development that was comparable to the control for cells sprayed without fibrin gel. When spraying within fibrin gel, ciliary development was lower at 28 days. Thus, spraying of vSMCs and RECs was proved to be a suitable method for tissue engineering. Especially for RECs, this application is of special significance when coating luminal structures or other unfavorable topographies. PMID:26309803

  5. Plasma-sprayed coatings

    SciTech Connect

    Herman, H.

    1988-09-01

    Plasma spraying is one way to apply protective coatings. The hot, high-speed flame of a plasma gun can melt a powder of almost any ceramic or metal and spray it to form a coating for protection against corrosion, wear or high temperature. The technique carries much less risk of degrading the coating and substrate than many other high-temperature processes do, because the gas in the plasma flame is chemically inert and the target can be kept fairly cool. And yet a plasma gun can be only a little more cumbersome than a paint sprayer. Investigators are applying this technique to new materials. The General Electric Company is using vacuum plasma spraying to make freestanding components: intricate aircraft engine parts formed by plasma-spraying a superalloy on a removable substrate. Other workers spray ceramic particles or fibers and metal powder simulatious wrong, stiff composite materials: the ceramic particles dispersed in a matrix of metal. The author and colleagues at the U.S. Naval Research Laboratory have fabricated a thick film of high-temperature superconductor by plasma-spraying the compound in the form of a powder. 7 figs.

  6. The regulation of flow through residual spray nozzles

    PubMed Central

    Lonergan, Richard P.; Hall, Lawrence B.

    1959-01-01

    Used residual spray nozzles, which have been discarded because of the increase in discharge rates, may be used again if their discharge rates are reduced by a metering orifice placed in the nozzle tip. A suitable orifice in a polyethylene disc is described. On the basis of laboratory test results, such a disc appears to be an inexpensive and satisfactory metering device for use in combination with worn spray nozzles. PMID:14418102

  7. Fabrication and Testing of Tapered Electro-spray Nozzles

    DTIC Science & Technology

    2012-09-01

    oxidized nozzle with broken top cap. 15 The ultrasonic breaking of the etch mask was found to be a low-yield methodology, with some caps breaking...Fabrication and Testing of Tapered Electro-spray Nozzles by Brendan M. Hanrahan and C. Mike Waits ARL-TR-6226 September 2012...September 2012 Fabrication and Testing of Tapered Electro-spray Nozzles Brendan M. Hanrahan and C. Mike Waits Sensors and Electron Devices

  8. Structure of Evaporating and Combusting Sprays: Measurements and Predictions

    NASA Technical Reports Server (NTRS)

    Shuen, J. S.; Solomon, A. S. P.; Faeth, G. M.

    1983-01-01

    Complete measurements of the structure of nonevaporating, evaporating and combusting sprays for sufficiently well defined boundary conditions to allow evaluation of models of these processes were obtained. The development of rational design methods for aircraft combustion chambers and other devices involving spray combustion were investigated. Three methods for treating the discrete phase are being considered: a locally homogeneous flow (LHF) model, a deterministic separated flow (DSF) model, and a stochastic separated flow (SSF) model. The main properties of these models are summarized.

  9. Experimental and computational analysis of soft tissue stiffness in forearm using a manual indentation device.

    PubMed

    Iivarinen, Jarkko T; Korhonen, Rami K; Julkunen, Petro; Jurvelin, Jukka S

    2011-12-01

    A hand held stiffness meter can be used to measure indentation stiffness of human soft tissues, sensitively altered, e.g., by pathological tissue swelling. Under indentation load, the relative contribution of each soft tissue component (i.e., skin, adipose tissue and muscle) to the biomechanical response is not known. In the present study, we evaluated the biomechanical role of different soft tissues in relaxed, physically stressed and oedemic human forearm. Soft tissue stiffness of the forearms of nine healthy human subjects was measured under four different test protocols: (1) forearm at rest, (2) forearm under isometric flexor loading, (3) forearm under isometric extensor loading, and (4) forearm under venous occlusion. In (2) and (3) the loading forces were monitored using a dynamometer, and in (4) the soft tissue swelling was induced by venous occlusion using a pressure cuff. At the site of indentation, thickness of different tissue layers (skin, adipose tissue and muscle) was measured using B-mode ultrasound imaging. Layered, hyperelastic finite element (FE) model of the indentation measurement was created and the model response was matched with that of the stiffness meter to determine the elastic modulus for each tissue in the model. Optimized values of the elastic modulus for skin and adipose tissue at rest were 210 kPa and 1.9 kPa, respectively. Further, significance of the variations in stiffness of different tissues on the indentation response was tested. Experimentally, indentation stiffness of the forearm increased during isometric extensor and flexor loads as well as under venous occlusion by 53, 91 and 15%, respectively. The FE model could reproduce the experimental responses primarily by the increased modulus of skin; 112% (446 kPa), 210% (651 kPa) and 21% (254 kPa) under flexor and extensor loading as well as during venous occlusion, respectively. The indentation response was 9-16 times more sensitive to changes in the mechanical properties of skin

  10. An experimental device for accurate ultrasounds measurements in liquid foods at high pressure

    NASA Astrophysics Data System (ADS)

    Hidalgo-Baltasar, E.; Taravillo, M.; Baonza, V. G.; Sanz, P. D.; Guignon, B.

    2012-12-01

    The use of high hydrostatic pressure to ensure safe and high-quality product has markedly increased in the food industry during the last decade. Ultrasonic sensors can be employed to control such processes in an equivalent way as they are currently used in processes carried out at room pressure. However, their installation, calibration and use are particularly challenging in the context of a high pressure environment. Besides, data about acoustic properties of food under pressure and even for water are quite scarce in the pressure range of interest for food treatment (namely, above 200 MPa). The objective of this work was to establish a methodology to determine the speed of sound in foods under pressure. An ultrasonic sensor using the multiple reflections method was adapted to a lab-scale HHP equipment to determine the speed of sound in water between 253.15 and 348.15 K, and at pressures up to 700 MPa. The experimental speed-of-sound data were compared to the data calculated from the equation of state of water (IAPWS-95 formulation). From this analysis, the way to calibrate cell path was validated. After this calibration procedure, the speed of sound could be determined in liquid foods by using this sensor with a relative uncertainty between (0.22 and 0.32) % at a confidence level of 95 % over the whole pressure domain.

  11. 1800 MHz in vitro exposure device for experimental studies on the effects of mobile communication systems.

    PubMed

    Ardoino, L; Lopresto, V; Mancini, S; Pinto, R; Lovisolo, G A

    2004-01-01

    A wire patch cell (WPC) operating at the uplink frequency band of GSM 1800 MHz has been designed for in vitro experiments with the aim of investigating the possible biological effects of electromagnetic radiation associated with cellular phones. The 1800 MHz WPC design is a direct descendant of the original 900 MHz WPC introduced by Laval et al. This system provides a homogeneous specific absorption rate distribution, using four 3.5 cm petri dishes simultaneously. Numerical dosimetry has been performed using a commercial code (CST Microwave Studio), in order to evaluate accurately the efficiency of the structure (in terms of W kg(-1) per 1 W input power) and the distribution in the chosen biological target. The numerical results have been confirmed by experimental measurements performed by measuring thermal increase due to a high power impulse. The efficiency of the structure is 1.25 +/- 25% W kg(-1) per 1 W input power higher than the efficiency of the 900 MHz WPC. A few adjustments have been made in order to use the WPC in a standard incubator and to avoid thermal increases related to the radio frequency exposure. This exposure system has been adopted for the experiments scheduled in the RAMP and GUARD projects (VFPE).

  12. A new experimental device to evaluate eye ulcers using a multispectral electrical impedance technique

    NASA Astrophysics Data System (ADS)

    Bellotti, Mariela I.; Bast, Walter; Berra, Alejandro; Bonetto, Fabián J.

    2011-07-01

    We present a novel experimental technique to determine eye ulcers in animals using a spectral electrical impedance technique. We expect that this technique will be useful in dry eye syndrome. We used a sensor that is basically a platinum (Pt) microelectrode electrically insulated by glass from a cylindrical stainless steel counter-electrode. This sensor was applied to the naked eye of New Zealand rabbits (2.0-3.5 kg in weight). Whereas half of the eyes were normal (control), we applied to the remainder a few drops of 20% (v/v) alcohol to produce an ulcer in the eye. Using a multispectral electrical impedance system we measured ulcerated and control eyes and observed significant difference between normal and pathological samples. We also investigated the effects of different applied pressures and natural degradation of initially normal eyes as a function of time. We believe that this technique could be sufficiently sensitive and repetitive to help diagnose ocular surface diseases such as dry eye syndrome.

  13. Feedback-controlled heat transport in quantum devices: theory and solid-state experimental proposal

    NASA Astrophysics Data System (ADS)

    Campisi, Michele; Pekola, Jukka; Fazio, Rosario

    2017-05-01

    A theory of feedback-controlled heat transport in quantum systems is presented. It is based on modelling heat engines as driven multipartite systems subject to projective quantum measurements and measurement-conditioned unitary evolutions. The theory unifies various results presented previously in the literature. Feedback control breaks time reversal invariance. This in turn results in the fluctuation relation not being obeyed. Its restoration occurs through appropriate accounting of the gain and use of information via measurements and feedback. We further illustrate an experimental proposal for the realisation of a Maxwell demon using superconducting circuits and single-photon on-chip calorimetry. A two-level qubit acts as a trap-door, which, conditioned on its state, is coupled to either a hot resistor or a cold one. The feedback mechanism alters the temperatures felt by the qubit and can result in an effective inversion of temperature gradient, where heat flows from cold to hot thanks to the gain and use of information.

  14. Some Effects of Air and Fuel Oil Temperatures on Spray Penetration and Dispersion

    NASA Technical Reports Server (NTRS)

    Gelalles, A G

    1930-01-01

    Presented here are experimental results obtained from a brief investigation of the appearance, penetration, and dispersion of oil sprays injected into a chamber of highly heated air at atmospheric pressure. The development of single sprays injected into a chamber containing air at room temperature and at high temperature was recorded by spray photography equipment. A comparison of spray records showed that with the air at the higher temperature, the spray assumed the appearance of thin, transparent cloud, the greatest part of which rapidly disappeared from view. With the chamber air at room temperature, a compact spray with an opaque core was obtained. Measurements of the records showed a decrease in penetration and an increase in the dispersion of the spray injected into the heated air. No ignition of the fuel injected was observed or recorded until the spray particles came in contact with the much hotter walls of the chamber about 0.3 second after the start of injection.

  15. Tomographical transformation of Malvern spray measurements

    NASA Technical Reports Server (NTRS)

    Zhu, H. M.; Sun, T. Y.; Chigier, N.

    1987-01-01

    A new method is described which directly transforms Malvern line-integral data into point measurements of the radial drop mean size distribution and liquid volume concentration distribution. The transformed results have been compared with experimental point measurements by photography and the phase/Doppler spray analyzer. The comparison reveals the relation between point measurements and line-of-sight measurements. Three kinds of nozzles were investigated. After tomographical transformation of the Malvern results the different structures of the spray are revealed. A newly derived formula simplifies the transformation procedure. This method provides a direct means to extend the applicability of the Malvern particle sizer and has the potential to be developed for use in unsymmetric sprays.

  16. Analysis of polydisperse fuel spray flame

    NASA Astrophysics Data System (ADS)

    Nave, Ophir; Lehavi, Yaron; Ajadi, Suraju; Gol'dshtein, Vladimir

    2017-02-01

    In this paper we analyzed the model of polydisperse fuel spray flame by using the sectional approach to describe the droplet-droplet interaction within the spray. The radii of the droplets are described by a probability density function. Our numerical simulations include a comparative analysis between three empirical droplet size distributions: the Rosin-Rammler distribution, the log-normal distribution and the Nakiyama-Tanasawa distribution. The log-normal distribution was found to produce a reasonable approximation to both the number and volume size distribution function. In addition our comparative analysis includes the application of the homotopy analysis method which yields convergent solutions for all values of the relevant parameters. We compared the above results to experimental fuel spray data such as {it{Tetralin}}, n-{it{Decane}}, and n-{it{Heptane}}.

  17. Spray Behavior and Atomization Characteristics of Biodiesel

    NASA Astrophysics Data System (ADS)

    Choi, Seung-Hun; Oh, Young-Taig

    Biodiesel has large amount of oxygen in itself, which make it very efficient in reducing exhaust emission by improving combustion inside an engine. But biodiesel has a low temperature flow problem because it has a high viscosity. In this study, the spray behavior and atomization characteristics were investigated to confirm of some effect for the combination of non-esterification biodiesel and fuel additive WDP and IPA. The process of spray was visualized through the visualization system composed of a halogen lamp and high speed camera, and atomization characteristics were investigated through LDPA. When blending WDP and IPA with biodiesel, atomization and spray characteristics were improved. Through this experimental result, SMD of blended fuel, WDP 25% and biodiesel 75%, was 33.9% reduced at distance 6cm from a nozzle tip under injection pressure 30MPa.

  18. Transport study in unsaturated porous media by tracer experiment in a dichromatic X-ray experimental device

    NASA Astrophysics Data System (ADS)

    Latrille, C.; Néel, M. C.

    2013-05-01

    Estimating contaminant migration in the context of waste disposal and/or environmental remediation of polluted soils requires a complete understanding of the underlying transport processes. In unsaturated porous media, water content is one of the most determining parameters to describe solute migration because it impacts directly on solute pore velocity. However, numerous studies are satisfied with only a global or a partial spatial distribution of water content within the studied porous media. Therefore, distribution of water content in porous media must be precisely achieved to optimize transport processes modeling. Tracer experiments with downward flow were performed on the BEETI experimental device equipped with a sand column. Water content and concentration profiles of tracer (KI) were measured along the column during experiment. The relative dispersion of water content, calculated along the column, gives an idea of influence of this parameter on transport properties. A relationship between pore velocity, Darcy flow velocity and water content is proposed.

  19. Analytical procedure for experimental quantification of carrier concentration in semiconductor devices by using electric scanning probe microscopy

    NASA Astrophysics Data System (ADS)

    Fujita, Takaya; Matsumura, Koji; Itoh, Hiroshi; Fujita, Daisuke

    2014-04-01

    Scanning capacitance microscopy (SCM) is based on a contact-mode variant of atomic force microscopy, which is used for imaging two-dimensional carrier (electrons and holes) distributions in semiconductor devices. We introduced a method of quantification of the carrier concentration by experimentally deduced calibration curves, which were prepared for semiconductor materials such as silicon and silicon carbide. The analytical procedure was circulated to research organizations in a round-robin test. The effectiveness of the method was confirmed for practical analysis and for what is expected for industrial pre-standardization from the viewpoint of comparability among users. It was also applied to other electric scanning probe microscopy techniques such as scanning spreading resistance microscopy and scanning nonlinear dielectric microscopy. Their depth profiles of carrier concentration were found to be in good agreement with those characterized by SCM. These results suggest that our proposed method will be compatible with future next-generation microscopy.

  20. Containment atmosphere response to external sprays

    SciTech Connect

    Green, J.; Almenas, K.

    1995-09-01

    The application of external sprays to a containment steel shell can be an effective energy removal method and has been proposed in the passive AP-600 design. Reduction of the steel shell temperature in contact with the containment atmosphere enhances both heat and mass transfer driving forces. Large scale experimental data in this area is scarce, therefore the measurements obtained from the E series tests conducted at the German HDR facility deserve special attention. These long term tests simulated various severe accident conditions, including external spraying of the hemispherical steel shell. This investigation focuses upon the integral response of the HDR containment atmosphere during spray periods and upon methods by which lumped parameter system codes, like CONTAIN, model the underlying condensation phenomena. Increases in spray water flowrates above a minimum value were ineffective at improving containment pressure reduction since the limiting resistance for energy transfer lies in the noncondensable-vapor boundary layer at the inner condensing surface. The spray created an unstable condition by cooling the upper layers of a heated atmosphere and thus inducing global natural circulation flows in the facility and subsequently, abrupt changes in lighter-than-air noncondensable (J{sub 2}/He) concentrations. Modeling results using the CONTAIN code are outlined and code limitations are delineated.

  1. Microalgal cell disruption via ultrasonic nozzle spraying.

    PubMed

    Wang, M; Yuan, W

    2015-01-01

    The objective of this study was to understand the effect of operating parameters, including ultrasound amplitude, spraying pressure, nozzle orifice diameter, and initial cell concentration on microalgal cell disruption and lipid extraction in an ultrasonic nozzle spraying system (UNSS). Two algal species including Scenedesmus dimorphus and Nannochloropsis oculata were evaluated. Experimental results demonstrated that the UNSS was effective in the disruption of microalgal cells indicated by significant changes in cell concentration and Nile red-stained lipid fluorescence density between all treatments and the control. It was found that increasing ultrasound amplitude generally enhanced cell disruption and lipid recovery although excessive input energy was not necessary for best results. The effect of spraying pressure and nozzle orifice diameter on cell disruption and lipid recovery was believed to be dependent on the competition between ultrasound-induced cavitation and spraying-generated shear forces. Optimal cell disruption was not always achieved at the highest spraying pressure or biggest nozzle orifice diameter; instead, they appeared at moderate levels depending on the algal strain and specific settings. Increasing initial algal cell concentration significantly reduced cell disruption efficiency. In all UNSS treatments, the effectiveness of cell disruption and lipid recovery was found to be dependent on the algal species treated.

  2. Experimental evaluation of the optical quality of DMD SLM for its application as Fourier holograms displaying device

    NASA Astrophysics Data System (ADS)

    Molodtsov, D. Y.; Cheremkhin, P. A.; Krasnov, V. V.; Rodin, V. G.

    2016-04-01

    In this paper, the optical quality of micromirror DMD spatial light modulator (SLM) is evaluated and its applicability as an output device for holographic filters in dispersive correlators is analyzed. The possibility of using of DMD SLM extracted from consumer DLP-projector was experimentally evaluated by displaying of Fourier holograms. Software for displaying of holograms was developed. Experiments on holograms reconstruction was conducted with a different number of holograms pixels (and different placement on SLM). Reduction of number of pixels of output hologram (i.e. size of minimum resolvable element) led to improvement of reconstructed image quality. The evaluation shows that not every DMD-chip has acceptable optical quality for its application as display device for Fourier holograms. It was determined that major factor of reconstructed image quality degradation is a curvature of surface of SLM or its safety glass. Ranging hologram size allowed to estimate approximate size of sufficiently flat area of SLM matrix. For tested SLM it was about 1.5 mm. Further hologram size increase led to significant reconstructed image quality degradation. Developed and applied a technique allows to quickly estimate maximum size of holograms that can be displayed with specific SLM without significant degradation of reconstructed image. Additionally it allows to identify areas on the SLM with increased curvature of the surface.

  3. Experimental study on using electromagnetic devices on bridge stay cables for simultaneous energy harvesting and vibration damping

    NASA Astrophysics Data System (ADS)

    Shen, Wenai; Zhu, Songye; Zhu, Hongping

    2016-06-01

    Flexible bridge stay cables are often vulnerable to problematic vibrations under dynamic excitations. However, from an energy perspective, such excessive vibrations denote a green and sustainable energy source to some electronic devices (such as semi-active dampers or wireless sensors) installed on the same cables. This paper presents an experimental study on a novel dual-function system called electromagnetic damper cum energy harvester (EMDEH). The proposed EMDEH, consisting of an electromagnetic device connected to an energy-harvesting circuit (EHC), simultaneously harvests cable vibration energy and provides sufficient damping to the cables. A fixed-duty-cycle buck-boost converter is employed as the EHC, which emulates a resistive load and provides approximately optimal damping and optimal energy harvesting efficiency when operating in discontinuous conduction mode. A 5.85 m long scaled stay cable installed with a prototype EMDEH is tested in the laboratory under a series of harmonic and random excitations. The EMDEH can achieve a control performance comparable to passive viscous dampers. An average electrical power of 31.6 and 21.51 mW is harvested under harmonic and random vibrations, respectively, corresponding to the efficiency of 16.9% and 13.8%, respectively. Moreover, this experimental study proves that optimal damping and energy harvesting can be achieved simultaneously, which answers a pending question regarding such a dual-objective optimization problem. Self-powered semi-active control systems or wireless sensor networks may be developed for bridge stay cables in the future based on the proposed concept in this study.

  4. An experimental and computational investigation of the post-yield behaviour of trabecular bone during vertebral device subsidence.

    PubMed

    Kelly, Nicola; Harrison, Noel M; McDonnell, Pat; McGarry, J Patrick

    2013-08-01

    Interbody fusion device subsidence has been reported clinically. An enhanced understanding of the mechanical behaviour of the surrounding bone would allow for accurate predictions of vertebral subsidence. The multiaxial inelastic behaviour of trabecular bone is investigated at a microscale and macroscale level. The post-yield behaviour of trabecular bone under hydrostatic and confined compression is investigated using microcomputed tomography-derived microstructural models, elucidating a mechanism of pressure-dependent yielding at the macroscopic level. Specifically, microstructural trabecular simulations predict a distinctive yield point in the apparent stress-strain curve under uniaxial, confined and hydrostatic compression. Such distinctive apparent stress-strain behaviour results from localised stress concentrations and material yielding in the trabecular microstructure. This phenomenon is shown to be independent of the plasticity formulation employed at a trabecular level. The distinctive response can be accurately captured by a continuum model using a crushable foam plasticity formulation in which pressure-dependent yielding occurs. Vertebral device subsidence experiments are also performed, providing measurements of the trabecular plastic zone. It is demonstrated that a pressure-dependent plasticity formulation must be used for continuum level macroscale models of trabecular bone in order to replicate the experimental observations, further supporting the microscale investigations. Using a crushable foam plasticity formulation in the simulation of vertebral subsidence, it is shown that the predicted subsidence force and plastic zone size correspond closely with the experimental measurements. In contrast, the use of von Mises, Drucker-Prager and Hill plasticity formulations for continuum trabecular bone models lead to over prediction of the subsidence force and plastic zone.

  5. Experimental demonstration and devices optimization of NRZ-DPSK amplitude regeneration scheme based on SOAs.

    PubMed

    Cao, Tong; Chen, Liao; Yu, Yu; Zhang, Xinliang

    2014-12-29

    We propose and experimentally demonstrate a novel scheme which can simultaneously realize wavelength-preserving and phase-preserving amplitude noise compression of a 40 Gb/s distorted non-return-to-zero differential-phase-shift keying (NRZ-DPSK) signal. In the scheme, two semiconductor optical amplifiers (SOAs) are exploited. The first one (SOA1) is used to generate the inverted signal based on SOA's transient cross-phase modulation (T-XPM) effect and the second one (SOA2) to regenerate the distorted NRZ-DPSK signal using SOA's cross-gain compression (XGC) effect. In the experiment, the bit error ratio (BER) measurements show that power penalties of constructive and destructive demodulation at BER of 10-9 are -1.75 and -1.01 dB, respectively. As the nonlinear effects and the requirements of the two SOAs are completely different, quantum-well (QW) structures has been separately optimized. A complicated theoretical model by combining QW band structure calculation with SOA's dynamic model is exploited to optimize the SOAs, in which both interband effect (carrier density variation) and intraband effect (carrier temperature variation) are taken into account. Regarding SOA1, we choose the tensile strained QW structure and large optical confinement factor to enhance the T-XPM effect. Regarding SOA2, the compressively strained QW structure is selected to reduce the impact of excess phase noise induced by amplitude fluctuations. Exploiting the optimized QW SOAs, better amplitude regeneration performance is demonstrated successfully through numerical simulation. The proposed scheme is intrinsically stable comparing with the interferometer structure and can be integrated on a chip, making it a practical candidate for all-optical amplitude regeneration of high-speed NRZ-DPSK signal.

  6. Measurements in liquid fuel sprays

    NASA Technical Reports Server (NTRS)

    Chigier, N.

    1984-01-01

    Techniques for studying the events directly preceding combustion in the liquid fuel sprays are being used to provide information as a function of space and time on droplet size, shape, number density, position, angle of flight and velocity. Spray chambers were designed and constructed for: (1) air-assist liquid fuel research sprays; (2) high pressure and temperature chamber for pulsed diesel fuel sprays; and (3) coal-water slurry sprays. Recent results utilizing photography, cinematography, and calibration of the Malvern particle sizer are reported. Systems for simultaneous measurement of velocity and particle size distributions using laser Doppler anemometry interferometry and the application of holography in liquid fuel sprays are being calibrated.

  7. Optimal feature extraction for segmentation of Diesel spray images.

    PubMed

    Payri, Francisco; Pastor, José V; Palomares, Alberto; Juliá, J Enrique

    2004-04-01

    A one-dimensional simplification, based on optimal feature extraction, of the algorithm based on the likelihood-ratio test method (LRT) for segmentation in colored Diesel spray images is presented. If the pixel values of the Diesel spray and the combustion images are represented in RGB space, in most cases they are distributed in an area with a given so-called privileged direction. It is demonstrated that this direction permits optimal feature extraction for one-dimensional segmentation in the Diesel spray images, and some of its advantages compared with more-conventional one-dimensional simplification methods, including considerably reduced computational cost while accuracy is maintained within more than reasonable limits, are presented. The method has been successfully applied to images of Diesel sprays injected at room temperature as well as to images of sprays with evaporation and combustion. It has proved to be valid for several cameras and experimental arrangements.

  8. The role of drop velocity in statistical spray description

    NASA Technical Reports Server (NTRS)

    Groeneweg, J. F.; El-Wakil, M. M.; Myers, P. S.; Uyehara, O. A.

    1978-01-01

    The justification for describing a spray by treating drop velocity as a random variable on an equal statistical basis with drop size was studied experimentally. A double-exposure technique using fluorescent drop photography was used to make size and velocity measurements at selected locations in a steady ethanol spray formed by a swirl atomizer. The size-velocity data were categorized to construct bivariate spray density functions to describe the spray immediately after formation and during downstream propagation. It was found that a statistical treatment of drop velocity was supported by the data. Spray density function shapes and modal characteristics depended strongly on position and the amount of droplet-gas interaction that had occurred. Bimodal density functions were formed by environmental interaction during downstream propagation. Large differences were also found between spatial mass density and mass flux size distributions at the same location.

  9. Experimental study on the effect of nozzle hole-to-hole angle on the near-field spray of diesel injector using fast X-ray phase-contrast imaging

    SciTech Connect

    Zhang, Xusheng; Moon, Seoksu; Gao, Jian; Dufresne, Eric M.; Fezzaa, Kamel; Wang, Jin

    2016-12-01

    Fuel atomization and vaporization process play a critical role in determining the engine combustion and emission. The primary near-nozzle breakup is the vital link between the fuel emerging from the nozzle and the fully atomized spray. In this study, the near-nozzle spray characteristics of diesel injector with different umbrella angle (UA) were investigated using high-speed X-ray phase-contrast imaging and quantitative image processing. A classic ‘dumbbell’ profile of spray width (SW) composed of three stages: opening stage, semisteady stage and closing stage. The SW peak of two-hole injectors was more than twice of that of single-hole injector at the opening and closing stages, corresponding to the hollow-cone spray. This indicated the vortex flow was formed with the increase of the UA. The higher injection pressure had little influence on the SW while led to earlier breakup closer to the nozzle. Significant fuel effect on the SW at higher needle lift was found. However, this effect could be neglect at lower needle lift due to the leading role of internal flow and cavitation on the near-field spray characteristics. In addition, the morphology-based breakup process was observed, which highlighted the important effect of internal flow on the spray development. The possibility of using hollow-cone spray in diesel injector was also discussed.

  10. A computational and experimental comparison of two outlet stators for the Nimbus LVAD. Left ventricular assist device.

    PubMed

    Burgreen, G W; Antaki, J F; Wu, J; le Blanc, P; Butler, K C

    1999-01-01

    Two designs of an outlet stator for the Nimbus axial flow left ventricular assist device (LVAD) are analyzed at nominal operating conditions. The original stator assembly (Design 1) has significant flow separation and reversal. A second stator assembly (Design 2) replaces the original tubular outer housing with a converging-diverging throat section with the intention of locally improving the fluid dynamics. Both stator designs are analyzed using computational fluid dynamics (CFD) analysis and experimental particle imaging flow visualization (PIFV). The computational and experimental methods indicate: 1) persistent regions of flow separation in Design 1 and improved fluid dynamics in Design 2; 2) blade-toblade velocity fields that are well organized at the blade tip yet chaotic at the blade hub for both designs; and 3) a moderate decrease in pressure recovery for Design 2 as compared with Design 1. The CFD analysis provides the necessary insight to identify a subtle, localized flow acceleration responsible for the decreased hydraulic efficiency of Design 2. In addition, the curiously low thrombogenicity of Design 1 is explained by the existence of a three-dimensional unsteady vortical flow structure that enhances boundary advection.

  11. Thermal spray processing

    NASA Technical Reports Server (NTRS)

    Herman, H.; Berndt, C. C.

    1995-01-01

    Thermal spray processing has been used for a number of years to cost-effecticely apply TBC's for a wide range of heat engine applications. In particular, bond coats are applied by plasma spray and HVOF techniques and partially-stabilized zirconia top coats are applied by plasma spray methods. Thermal spray involves melting and rapid transport of the molten particles to the substrate, where high-rate solidification and coating build-up occur. It is the very nature of this melt processing that leads to the unique layered microstructure, as well as the apparent imperfections, so readily identified with thermal spray. Modeling the process, process-induced residual stresses, and thermal conductivity will be discussed in light of a new understanding of porosity and its anisotropy. Microcracking can be understood using new approaches, allowing a fuller view of the processing-performance connection. Detailed electron microscopic, novel neutron diffraction and fracture analysis of the deposits can lead to a better understanding of how overall microstructure can be controlled to influence critical properties of the deposited TBC system.

  12. Evaluation of mechanical properties of Aluminum-Copper cold sprayed and alloy 625 wire arc sprayed coatings

    NASA Astrophysics Data System (ADS)

    Bashirzadeh, Milad

    This study examines microstructural-based mechanical properties of Al-Cu composite deposited by cold spraying and wire arc sprayed nickel-based alloy 625 coating using numerical modeling and experimental techniques. The microhardness and elastic modulus of samples were determined using the Knoop hardness technique. Hardness in both transverse and longitudinal directions on the sample cross-sections has been measured. An image-based finite element simulation algorithm was employed to determine the mechanical properties through an inverse analysis. In addition mechanical tests including, tensile, bending, and nano-indentation tests were performed on alloy 625 wire arc sprayed samples. Overall, results from the experimental tests are in relatively good agreement for deposited Al-Cu composites and alloy 625 coating. However, results obtained from numerical simulation are significantly higher in value than experimentally obtained results. Examination and comparison of the results are strong indications of the influence of microstructure characteristics on the mechanical properties of thermally spray deposited coatings.

  13. LES/FMDF of High Speed Spray Combustion

    NASA Astrophysics Data System (ADS)

    Irannejad, Abolfazl; Jaberi, Farhad

    2013-11-01

    High speed evaporating and combusting sprays are computed with the hybrid two-phase large eddy simulation (LES)/filtered mass density function (FMDF) methodology. In this methodology, the resolved fluid velocity is obtained by solving the filtered form of the compressible Navier-Stokes equations with high-order finite difference schemes. The scalar (temperature and species mass fractions) field is obtained by solving the FMDF transport equation with a Lagrangian stochastic method. The spray is simulated with the Lagrangian droplets together with stochastic breakup and finite rate heat and mass transfer models. The liquid volume fraction is included in the LES/FMDF for denser spray regions. Simulations of high speed evaporating sprays with and without combustion for a range of gas and spray conditions indicate that the two-phase LES/FMDF results are consistent and compare well with the experimental results for global spray variables such as the spray penetration and flame lift-off lengths. The gas velocity and turbulence generated by the spray are found to be very significant in all simulated cases. A broad spectrum of droplet sizes is also found to be generated by the complex and coupled effects of the gas flow turbulence, droplet breakup, evaporation and combustion.

  14. Development of process data capturing, analysis and controlling for thermal spray techniques - SprayTracker

    NASA Astrophysics Data System (ADS)

    Kelber, C.; Marke, S.; Trommler, U.; Rupprecht, C.; Weis, S.

    2017-03-01

    Thermal spraying processes are becoming increasingly important in high-technology areas, such as automotive engineering and medical technology. The method offers the advantage of a local layer application with different materials and high deposition rates. Challenges in the application of thermal spraying result from the complex interaction of different influencing variables, which can be attributed to the properties of different materials, operating equipment supply, electrical parameters, flow mechanics, plasma physics and automation. In addition, spraying systems are subject to constant wear. Due to the process specification and the high demands on the produced coatings, innovative quality assurance tools are necessary. A central aspect, which has not yet been considered, is the data management in relation to the present measured variables, in particular the spraying system, the handling system, working safety devices and additional measuring sensors. Both the recording of all process-characterizing variables, their linking and evaluation as well as the use of the data for the active process control presuppose a novel, innovative control system (hardware and software) that was to be developed within the scope of the research project. In addition, new measurement methods and sensors are to be developed and qualified in order to improve the process reliability of thermal spraying.

  15. Miniature spray-painting booth

    NASA Technical Reports Server (NTRS)

    Fee, K. W.

    1970-01-01

    Transparent spray booth provides method for quality painting and repair of surfaces in clean room or other specialized environments. Overspray and virtually all contaminating vapor and odor can be eliminated. Touch-up painting is achieved with spray gun.

  16. Nasal spray flu vaccine (image)

    MedlinePlus

    The flu vaccine can also be administered as a nasal spray instead of the usual injection method. It can be ... the recombinant influenza vaccine (RIV). The nasal spray flu vaccine (live attenuated influenza vaccine or LAIV) should not ...

  17. SPRAY CALCINATION REACTOR

    DOEpatents

    Johnson, B.M.

    1963-08-20

    A spray calcination reactor for calcining reprocessin- g waste solutions is described. Coaxial within the outer shell of the reactor is a shorter inner shell having heated walls and with open regions above and below. When the solution is sprayed into the irner shell droplets are entrained by a current of gas that moves downwardly within the inner shell and upwardly between it and the outer shell, and while thus being circulated the droplets are calcined to solids, whlch drop to the bottom without being deposited on the walls. (AEC) H03 H0233412 The average molecular weights of four diallyl phthalate polymer samples extruded from the experimental rheometer were redetermined using the vapor phase osmometer. An amine curing agent is required for obtaining suitable silver- filled epoxy-bonded conductive adhesives. When the curing agent was modified with a 47% polyurethane resin, its effectiveness was hampered. Neither silver nor nickel filler impart a high electrical conductivity to Adiprenebased adhesives. Silver filler was found to perform well in Dow-Corning A-4000 adhesive. Two cascaded hot-wire columns are being used to remove heavy gaseous impurities from methane. This purified gas is being enriched in the concentric tube unit to approximately 20% carbon-13. Studies to count low-level krypton-85 in xenon are continuing. The parameters of the counting technique are being determined. The bismuth isotopes produced in bismuth irradiated for polonium production are being determined. Preliminary data indicate the presence of bismuth207 and bismuth-210m. The light bismuth isotopes are probably produced by (n,xn) reactions bismuth-209. The separation of uranium-234 from plutonium-238 solutions was demonstrated. The bulk of the plutonium is removed by anion exchange, and the remainder is extracted from the uranium by solvent extraction techniques. About 99% of the plutonium can be removed in each thenoyltrifluoroacetone extraction. The viscosity, liquid density, and

  18. Acoustic effects of sprays

    NASA Technical Reports Server (NTRS)

    Pindera, Maciej Z.; Przekwas, Andrzej J.

    1994-01-01

    Since the early 1960's, it has been known that realistic combustion models for liquid fuel rocket engines should contain at least a rudimentary treatment of atomization and spray physics. This is of particular importance in transient operations. It has long been recognized that spray characteristics and droplet vaporization physics play a fundamental role in determining the stability behavior of liquid fuel rocket motors. This paper gives an overview of work in progress on design of a numerical algorithm for practical studies of combustion instabilities in liquid rocket motors. For flexibility, the algorithm is composed of semi-independent solution modules, accounting for different physical processes. Current findings are report and future work is indicated. The main emphasis of this research is the development of an efficient treatment to interactions between acoustic fields and liquid fuel/oxidizer sprays.

  19. Control of High-Speed Spray Flows Using a Steady, Parallel Control Flow Under the Influence of the Coanda Effect

    NASA Astrophysics Data System (ADS)

    Allen, Dustin; Smith, Barton

    2007-11-01

    An experimental demonstration of a jet vectoring technique used in our novel spray device called a Coanda-assisted Spray Manipulation (CSM) nozzle is presented. The CSM makes use of a Coanda-like effect on axisymmetric geometries through the interaction of a high volume-flow primary jet flowing through the center of a collar and a secondary high-momentum jet parallel to the first and adjacent to a convex collar. The control jet attaches to the convex wall and vectors due to the Coanda effect, entraining and vectoring the primary jet, resulting in controllable r-theta directional spraying. Various annular secondary exit holes and curved wall radii were tested over a range of momentum flux ratios to study the effects of these variables on the vectored jet angle. Particle Image Velocimetry (PIV) was used to determine the vectoring angle and the profile of the primary jet in each experiment. The experiments show that the secondary exit hole size and curve wall radius, along with the momentum ratios of the two jets predominantly affect the vectoring angle of the primary jet. Also, the jet profile is largely unchanged with vectoring for high velocity flows, which is important for the thermal spray applications for which CSM will be used.

  20. Hydrolysis of CuCl{sub 2} in the Cu-Cl thermochemical cycle for hydrogen production : experimental studies using a spray reactor with an ultrasonic atomizer.

    SciTech Connect

    Ferrandon, M. S.; Lewis, M. A.; Alvarez, F.; Shafirovich, E.; Chemical Sciences and Engineering Division; Univ. of Texas at El Paso

    2010-03-01

    The Cu-Cl thermochemical cycle is being developed as a hydrogen production method. Prior proof-of-concept experimental work has shown that the chemistry is viable while preliminary modeling has shown that the efficiency and cost of hydrogen production have the potential to meet DOE's targets. However, the mechanisms of CuCl{sub 2} hydrolysis, an important step in the Cu-Cl cycle, are not fully understood. Although the stoichiometry of the hydrolysis reaction, 2CuCl{sub 2} + H{sub 2}O {leftrightarrow} Cu{sub 2}OCl{sub 2} + 2HCl, indicates a necessary steam-to-CuCl{sub 2} molar ratio of 0.5, a ratio as high as 23 has been typically required to obtain near 100% conversion of the CuCl{sub 2} to the desired products at atmospheric pressure. It is highly desirable to conduct this reaction with less excess steam to improve the process efficiency. Per Le Chatelier's Principle and according to the available equilibrium-based model, the needed amount of steam can be decreased by conducting the hydrolysis reaction at a reduced pressure. In the present work, the experimental setup was modified to allow CuCl{sub 2} hydrolysis in the pressure range of 0.4-1 atm. Chemical and XRD analyses of the product compositions revealed the optimal steam-to-CuCl{sub 2} molar ratio to be 20-23 at 1 atm pressure. The experiments at 0.4 atm and 0.7 atm showed that it is possible to lower the steam-to-CuCl{sub 2} molar ratio to 15, while still obtaining good yields of the desired products. An important effect of running the reaction at reduced pressure is the significant decrease of CuCl concentration in the solid products, which was not predicted by prior modeling. Possible explanations based on kinetics and residence times are suggested.

  1. Controlled overspray spray nozzle

    NASA Technical Reports Server (NTRS)

    Prasthofer, W. P. (Inventor)

    1981-01-01

    A spray system for a multi-ingredient ablative material wherein a nozzle A is utilized for suppressing overspray is described. The nozzle includes a cyclindrical inlet which converges to a restricted throat. A curved juncture between the cylindrical inlet and the convergent portion affords unrestricted and uninterrupted flow of the ablative material. A divergent bell-shaped chamber and adjustable nozzle exit B is utilized which provides a highly effective spray pattern in suppressing overspray to an acceptable level and producing a homogeneous jet of material that adheres well to the substrate.

  2. Sprayed Coating Renews Butyl Rubber

    NASA Technical Reports Server (NTRS)

    Martin, R. B.

    1982-01-01

    Damaged butyl rubber products are renewed by spray technique originally developed for protective suits worn by NASA workers. A commercial two-part adhesive is mixed with Freon-113 (or equivalent) trichlorotrifluoroethane to obtain optimum viscosity for spraying. Mix is applied with an external-air-mix spray gun.

  3. A user-friendly model for spray drying to aid pharmaceutical product development.

    PubMed

    Grasmeijer, Niels; de Waard, Hans; Hinrichs, Wouter L J; Frijlink, Henderik W

    2013-01-01

    The aim of this study was to develop a user-friendly model for spray drying that can aid in the development of a pharmaceutical product, by shifting from a trial-and-error towards a quality-by-design approach. To achieve this, a spray dryer model was developed in commercial and open source spreadsheet software. The output of the model was first fitted to the experimental output of a Büchi B-290 spray dryer and subsequently validated. The predicted outlet temperatures of the spray dryer model matched the experimental values very well over the entire range of spray dryer settings that were tested. Finally, the model was applied to produce glassy sugars by spray drying, an often used excipient in formulations of biopharmaceuticals. For the production of glassy sugars, the model was extended to predict the relative humidity at the outlet, which is not measured in the spray dryer by default. This extended model was then successfully used to predict whether specific settings were suitable for producing glassy trehalose and inulin by spray drying. In conclusion, a spray dryer model was developed that is able to predict the output parameters of the spray drying process. The model can aid the development of spray dried pharmaceutical products by shifting from a trial-and-error towards a quality-by-design approach.

  4. A User-Friendly Model for Spray Drying to Aid Pharmaceutical Product Development

    PubMed Central

    Grasmeijer, Niels; de Waard, Hans; Hinrichs, Wouter L. J.; Frijlink, Henderik W.

    2013-01-01

    The aim of this study was to develop a user-friendly model for spray drying that can aid in the development of a pharmaceutical product, by shifting from a trial-and-error towards a quality-by-design approach. To achieve this, a spray dryer model was developed in commercial and open source spreadsheet software. The output of the model was first fitted to the experimental output of a Büchi B-290 spray dryer and subsequently validated. The predicted outlet temperatures of the spray dryer model matched the experimental values very well over the entire range of spray dryer settings that were tested. Finally, the model was applied to produce glassy sugars by spray drying, an often used excipient in formulations of biopharmaceuticals. For the production of glassy sugars, the model was extended to predict the relative humidity at the outlet, which is not measured in the spray dryer by default. This extended model was then successfully used to predict whether specific settings were suitable for producing glassy trehalose and inulin by spray drying. In conclusion, a spray dryer model was developed that is able to predict the output parameters of the spray drying process. The model can aid the development of spray dried pharmaceutical products by shifting from a trial-and-error towards a quality-by-design approach. PMID:24040240

  5. A simulation technique for predicting thickness of thermal sprayed coatings

    NASA Technical Reports Server (NTRS)

    Goedjen, John G.; Miller, Robert A.; Brindley, William J.; Leissler, George W.

    1995-01-01

    The complexity of many of the components being coated today using the thermal spray process makes the trial and error approach traditionally followed in depositing a uniform coating inadequate, thereby necessitating a more analytical approach to developing robotic trajectories. A two dimensional finite difference simulation model has been developed to predict the thickness of coatings deposited using the thermal spray process. The model couples robotic and component trajectories and thermal spraying parameters to predict coating thickness. Simulations and experimental verification were performed on a rotating disk to evaluate the predictive capabilities of the approach.

  6. Bond-coating in plasma-sprayed calcium-phosphate coatings.

    PubMed

    Oktar, F N; Yetmez, M; Agathopoulos, S; Lopez Goerne, T M; Goller, G; Peker, I; Ipeker, I; Ferreira, J M F

    2006-11-01

    The influence of bond-coating on the mechanical properties of plasma-spray coatings of hydroxyatite on Ti was investigated. Plasma-spray powder was produced from human teeth enamel and dentine. Before processing the main apatite coating, a very thin layer of Al2O3/TiO2 was applied on super clean and roughened, by Al2O3 blasting, Ti surface as bond-coating. The experimental results showed that bond-coating caused significant increase of the mechanical properties of the coating layer: In the case of the enamel powder from 6.66 MPa of the simple coating to 9.71 MPa for the bond-coating and in the case of the dentine powder from 6.27 MPa to 7.84 MPa, respectively. Both tooth derived powders feature high thermal stability likely due to their relatively high content of fluorine. Therefore, F-rich apatites, such those investigated in this study, emerge themselves as superior candidate materials for calcium phosphate coatings of producing medical devices. The methods of apatite powder production and shaping optimization of powder particles are both key factors of a successful coating. The methods used in this study can be adopted as handy, inexpensive and reliable ways to produce high quality of powders for plasma spray purposes.

  7. Application of linear response theory to experimental data of simultaneous radiation and annealing response of a CMOS device

    NASA Technical Reports Server (NTRS)

    Litovchenko, V.

    1988-01-01

    Results from the application of linear response theory are compared to experimental data from simultaneous radiation and annealing response of a CMOS device. In particular, a method is applied which was developed earlier to determine the characteristic time, t(0), as well as the parameters A and C in the 1n(t) dependence of the linear response function R(t) = -C + A1n(1-t/t(0)). The method is based on a study of the linear response for t being much less than t(0), when R(t) can be expanded in a power series of t: R(t) = R(0) + R'(0)t + 1/2R''(0)t-squared + 1/3R'''(0)t-cubed + ..., where R'(0) and R''(0) are, respectively, the first and second derivatives of R with respect to t. To find the linear response, R(t-t') is substituted in the form of this power series equation into a general equation for the shift of the threshold potential. To test the method, irradiation experiments were conducted on RCA 10(6) rad-hard CMOS IC's. A dose rate of approximately 130 rads/min was used. An IC was irradiated with Co-60 gamma rays for several hours, taking measurements of the threshold potential for one n-channel and one p-channel transistor every ten minutes. For the p-channel transistor, t(0) was found to be approximately 110 min and for the n-channel, t(0) was approximately 70 min. For the p-channel, the theoretical curve deviates from the experimental points only after 70 min; for the n-channel, the deviation takes place after 45 min. Additional findings are discussed and the application of the method to pure annealing is described.

  8. Use and characterization of linear nozzles for spray forming

    SciTech Connect

    Leon, D.D.; Kozarek, R.L.

    1995-11-01

    Commercial production of aluminum sheet and plate by spray atomization and deposition is a potentially attractive manufacturing alternative to conventional ingot metallurgy/hot-milling, and to continuous casting processes because of reduced energy requirements and reduced cost. To realize the full potential of this technology the Aluminum Company of America (Alcoa), under a cooperative agreement with the U.S. Department of Energy, has investigated currently available state-of-the-art atomization devices to develop nozzle design concepts whose spray characteristics are tailored for continuous sheet production. This paper will discuss Alcoa`s research and development work on three linear nozzle designs. The effect of geometry and process parameters on spray pattern and particle size distribution will be presented. The discussion will focus on the final spray formed deposit produced by these deposition systems.

  9. Numerical and experimental study on the flow distribution in a water manifold

    NASA Astrophysics Data System (ADS)

    Min, Gwansik; Jong Lee, Pil; Kang, Jong Hoon

    2016-03-01

    This study presents water distribution analysis of the device for spraying cooling water through specific nozzles numerically and experimentally. Numerical analysis was performed using the 3-D incompressible, multi-phase flow model, for different Reynolds numbers of 4 × 105, 8 × 105. Experimental analysis was performed at real-size, under the same conditions. The calculated results and the measured results for the distribution of flow were matched relatively well. The distribution of the nozzle flow depends on the Reynolds number.

  10. Picosecond imaging of sprays

    NASA Technical Reports Server (NTRS)

    Breisacher, Kevin; Liou, Larry; Wang, L.; Liang, X.; Galland, P.; Ho, P. P.; Alfano, R. R.

    1994-01-01

    Preliminary results from applying a Kerr-Fourier imaging system to a water/air spray produced by a shear coaxial element are presented. The physics behind ultrafast time-gated optical techniques is discussed briefly. A typical setup of a Kerr-Fourier time gating system is presented.

  11. Oxymetazoline Nasal Spray

    MedlinePlus

    ... Rinse the tip of the dispenser with hot water or wipe it clean after you use it.Follow the directions for using the nasal spray that appear on the package label. If you are using a product that comes in a pump dispenser, press down on the rim several times ...

  12. Ocean Spray Lubricates Winds

    ERIC Educational Resources Information Center

    Journal of College Science Teaching, 2005

    2005-01-01

    According to a new study by two University of California, Berkeley, mathematicians and their Russian colleague, the water droplets kicked up by rough seas serve to lubricate the swirling winds of hurricanes and cyclones, letting them build to speeds approaching 200 miles per hour. Without the lubricating effect of the spray, the mathematicians…

  13. Ocean Spray Lubricates Winds

    ERIC Educational Resources Information Center

    Journal of College Science Teaching, 2005

    2005-01-01

    According to a new study by two University of California, Berkeley, mathematicians and their Russian colleague, the water droplets kicked up by rough seas serve to lubricate the swirling winds of hurricanes and cyclones, letting them build to speeds approaching 200 miles per hour. Without the lubricating effect of the spray, the mathematicians…

  14. Mometasone Nasal Spray

    MedlinePlus

    ... in cold water and rinse them in cold water, let them dry at room temperature, and then put them back on the bottle.If the spray tip is clogged, wash it in cold water and then rinse it in cold water and ...

  15. Spray combustion stability project

    NASA Technical Reports Server (NTRS)

    Jeng, San-Mou; Litchford, Ron J.

    1992-01-01

    This report summarizes research activity on the Spray Combustion Stability Project, characterizes accomplishments and current status, and discusses projected future work. The purpose is to provide a concise conceptual overview of the research effort to date so the reader can quickly assimilate the gist of the research results and place them within the context of their potential impact on liquid rocket engine design technology.

  16. Experimental evidence of negative quantum capacitance in topological insulator for sub-60-mV/decade steep switching device

    NASA Astrophysics Data System (ADS)

    Choi, H.; Lee, H.; Park, J.; Yu, H.-Y.; Kim, T. G.; Shin, C.

    2016-11-01

    As a three-dimensional topological insulator (TI), bismuth telluride (Bi2Te3) has two-dimensional electron gas on its surface where negative quantum capacitance (NQC) can exist at a specific biasing condition. In order to experimentally confirm NQC in a TI, a metal-insulator-semiconductor (MIS) capacitor (i.e., metal-Bi2Te3-SiO2-silicon) is fabricated. The capacitance-voltage measurement of the MIS capacitor at 300 K shows that as the depletion capacitance in silicon decreases, the total capacitance of the MIS capacitor, which consists of two capacitors connected in series (i.e., insulator capacitor and depletion capacitor), increases in the depletion region at a frequency of 50 kHz. The amplified capacitance indicates the existence of NQC on the surface of the TI, and it originates from the strongly correlated electron system. The NQC of the TI opens avenues for sub-60-mV/decade steep switching silicon devices.

  17. Experimental and Numerical Investigations of Effects of Flow Control Devices Upon Flat-Plate Film Cooling Performance.

    PubMed

    Kawabata, Hirokazu; Funazaki, Ken-Ichi; Nakata, Ryota; Takahashi, Daichi

    2014-06-01

    This study deals with the experimental and numerical studies of the effect of flow control devices (FCDs) on the film cooling performance of a circular cooling hole on a flat plate. Two types of FCDs with different heights are examined in this study, where each of them is mounted to the flat plate upstream of the cooling hole by changing its lateral position with respect to the hole centerline. In order to measure the film effectiveness as well as heat transfer downstream of the cooling hole with upstream FCD, a transient method using a high-resolution infrared camera is adopted. The velocity field downstream of the cooling hole is captured by 3D laser Doppler velocimeter (LDV). Furthermore, the aerodynamic loss associated with the cooling hole with/without FCD is measured by a total pressure probe rake. The experiments are carried out at blowing ratios ranging from 0.5 to 1.0. In addition, numerical simulations are also made to have a better understanding of the flow field. LES approach is employed to solve the flow field and visualize the vortex structure around the cooling hole with FCD. When a taller FCD is mounted to the plate, the film effectiveness tends to increase due to the vortex structure generated by the FCD. As FCD is laterally shifted from the centerline, the film effectiveness increases, while the lift-off of cooling air is also promoted when FCD is put on the center line.

  18. Local infiltration devices at parking sites--experimental assessment of temporal changes in hydraulic and contaminant removal capacity.

    PubMed

    Achleitner, S; Engelhard, C; Stegner, U; Rauch, W

    2007-01-01

    On site infiltration of stormwater is a common practice in order to avoid hydraulic overload of the urban drainage system. If hydrological conditions allow on-site infiltration--this is even mandatory from a legal point of view. Focus in this work is on surface infiltration of stormwater from parking lots. Proper operation of those devices is assumed to be appr. 15 years, as permits granted are limited to this time. Questions are raised whether this considered life expectancy is feasible. One apprehension is a possible clogging effect reducing the hydraulic capacity of the swale. The second aim was to identify magnitudes of accumulated pollutant loads with respect to limitations onto lifetime. The experimental investigation covered infiltration swales of different ages from eleven supermarket parking lots in Tyrol. Hydraulic permeabilities were assessed as well as chemical conditions of the soil material regarding hydrocarbon index (HI) and heavy metals (Cu, Zn, Pb and Cd). Further mass balance of contaminants has been performed in order to assess the operational life time based on pollutant load consideration. Calculations were based on load estimations using literature based minima and maxima concentrations from surface flows. Testing the correlation of hydraulic and pollutant measurements against site specific parameters (age, traffic load) revealed no distinct relation. In general all measured pollutants were found under limit concentrations. Mass balance calculations showed that limit concentrations are not exceeded either for worst case loading and considering 15 years of operation.

  19. NATURAL GAS VARIABILITY IN CALIFORNIA: ENVIRONMENTAL IMPACTS AND DEVICE PERFORMANCE EXPERIMENTAL EVALUATION OF POLLUTANT EMISSIONS FROM RESIDENTIAL APPLIANCES

    SciTech Connect

    Singer, Brett C.; Apte, Michael G.; Black, Douglas R.; Hotchi, Toshifumi; Lucas, Donald; Lunden, Melissa M.; Mirer, Anna G.; Spears, Michael; Sullivan, Douglas P.

    2009-12-01

    The effect of liquefied natural gas on pollutant emissions was evaluated experimentally with used and new appliances in the laboratory and with appliances installed in residences, targeting information gaps from previous studies. Burner selection targeted available technologies that are projected to comprise the majority of installed appliances over the next decade. Experiments were conducted on 13 cooktop sets, 12 ovens, 5 broiler burners, 5 storage water heaters, 4 forced air furnaces, 1 wall furnace, and 6 tankless water heaters. Air-free concentrations and fuel-based emission factors were determined for carbon monoxide, nitrogen oxides, nitrogen dioxide, and the number of (predominantly ultrafine) particles over complete burns?including transient effects (device warm-up and intermittent firing of burners) following ignition--and during more stable end-of-burn conditions. Formaldehyde was measured over multi-burn cycles. The baseline fuel was Northern California line gas with Wobbe number (a measure of fuel energy delivery rate) of 1320-1340; test fuels had Wobbe numbers of roughly 1390 and 1420, and in some cases 1360. No ignition or operational problems were observed during test fuel use. Baseline emissions varied widely across and within burner groups and with burner operational mode. Statistically significant emissions changes were observed for some pollutants on some burners.

  20. Spray Drift Reduction Evaluations of Spray Nozzles Using a Standardized Testing Protocol

    DTIC Science & Technology

    2010-07-01

    1998, pp. 194–199. 7 Bilanin, A. J., Teske , M. E., Barry, J. W., and Eckblad, R. B., “AGDISP: The Aircraft Spray Dispersion Model, Code Development and...Experimental Validation,” Trans. ASAE, Vol. 32, 1989, pp. 327–334. 8 Teske , M. E., Thistle, H. W., and Ice, G. G., “Technical Advances in Modeling...Aerially Applied Sprays,” Trans. ASAE, Vol. 46, 2003, pp. 985–996. 9 Teske , M. E. and Thistle, H. W., “A Simulation of Release Height and Wind Speed

  1. Current implications of past DDT indoor spraying in Oman.

    PubMed

    Booij, Petra; Holoubek, Ivan; Klánová, Jana; Kohoutek, Jiří; Dvorská, Alice; Magulová, Katarína; Al-Zadjali, Said; Čupr, Pavel

    2016-04-15

    In Oman, DDT was sprayed indoors during an intensive malaria eradication program between 1976 and 1992. DDT can remain for years after spraying and is associated with potential health risk. This raises the concern for human exposure in areas where DDT was used for indoor spraying. Twelve houses in three regions with a different history of DDT indoor spraying were chosen for a sampling campaign in 2005 to determine p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT), p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and p,p'-dichlorodiphenyldichloroethane (p,p'-DDD) levels in indoor air, dust, and outdoor soil. Although DDT was only sprayed indoor, p,p'-DDT, p,p'-DDE and p,p'-DDD were also found in outdoor soil. The results indicate that release and exposure continue for years after cessation of spraying. The predicted cancer risk based on concentrations determined in 2005, indicate that there was still a significant cancer risk up to 13 to 16years after indoor DDT spraying. A novel approach, based on region-specific half-lives, was used to predict concentrations in 2015 and showed that more than 21years after spraying, cancer risk for exposure to indoor air, dust, and outdoor soil are acceptable in Oman for adults and young children. The model can be used for other locations and countries to predict prospective exposure of contaminants based on indoor experimental measurements and knowledge about the spraying time-schedule to extrapolate region-specific half-lives and predict effects on the human population years after spraying.

  2. A Method to Predict the Thickness of Poorly-Bonded Material Along Spray and Spray-Layer Boundaries in Cold Spray Deposition

    NASA Astrophysics Data System (ADS)

    Li, Yangfan; Hamada, Yukitaka; Otobe, Katsunori; Ando, Teiichi

    2017-02-01

    Multi-traverse CS provides a unique means for the production of thick coatings and bulk materials from powders. However, the material along spray and spray-layer boundaries is often poorly bonded as it is laid by the leading and trailing peripheries of the spray that carry powder particles with insufficient kinetic energy. For the same reason, the splats in the very first layer deposited on the substrate may not be bonded well either. A mathematical spray model was developed based on an axisymmetric Gaussian mass flow rate distribution and a stepped deposition yield to predict the thickness of such poorly-bonded layers in multi-traverse CS deposition. The predicted thickness of poorly-bonded layers in a multi-traverse Cu coating falls in the range of experimental values. The model also predicts that the material that contains poorly bonded splats could exceed 20% of the total volume of the coating.

  3. A Method to Predict the Thickness of Poorly-Bonded Material Along Spray and Spray-Layer Boundaries in Cold Spray Deposition

    NASA Astrophysics Data System (ADS)

    Li, Yangfan; Hamada, Yukitaka; Otobe, Katsunori; Ando, Teiichi

    2016-12-01

    Multi-traverse CS provides a unique means for the production of thick coatings and bulk materials from powders. However, the material along spray and spray-layer boundaries is often poorly bonded as it is laid by the leading and trailing peripheries of the spray that carry powder particles with insufficient kinetic energy. For the same reason, the splats in the very first layer deposited on the substrate may not be bonded well either. A mathematical spray model was developed based on an axisymmetric Gaussian mass flow rate distribution and a stepped deposition yield to predict the thickness of such poorly-bonded layers in multi-traverse CS deposition. The predicted thickness of poorly-bonded layers in a multi-traverse Cu coating falls in the range of experimental values. The model also predicts that the material that contains poorly bonded splats could exceed 20% of the total volume of the coating.

  4. Thermal spray for commercial shipbuilding

    NASA Astrophysics Data System (ADS)

    Rogers, F. S.

    1997-09-01

    Thermal spraying of steel with aluminum to protect it from corrosion is a technology that has been proven to work in the marine environment. The thermal spray coating system includes a paint sealer that is applied over the thermally sprayed aluminum. This extends the service life of the coating and provides color to the end product. The thermal spray system protects steel both through the principle of isolation (as in painting) and galvanizing. With this dual protection mechanism, steel is protected from corrosion even when the coating is damaged. The thermal- sprayed aluminum coating system has proved the most cost- effective corrosion protection system for the marine environment. Until recently, however, the initial cost of application has limited its use for general application. Arc spray technology has reduced the application cost of thermal spraying of aluminum to below that of painting. Commercial shipbuilders could use this technology to enhance their market position in the marine industry.

  5. Thermal Spray Formation of Polymer Coatings

    NASA Technical Reports Server (NTRS)

    Coquill, Scott; Galbraith, Stephen L.; Tuss. Darren L.; Ivosevic, Milan

    2008-01-01

    This innovation forms a sprayable polymer film using powdered precursor materials and an in-process heating method. This device directly applies a powdered polymer onto a substrate to form an adherent, mechanically-sound, and thickness-regulated film. The process can be used to lay down both fully dense and porous, e.g., foam, coatings. This system is field-deployable and includes power distribution, heater controls, polymer constituent material bins, flow controls, material transportation functions, and a thermal spray apparatus. The only thing required for operation in the field is a power source. Because this method does not require solvents, it does not release the toxic, volatile organic compounds of previous methods. Also, the sprayed polymer material is not degraded because this method does not use hot combustion gas or hot plasma gas. This keeps the polymer from becoming rough, porous, or poorly bonded.

  6. Plasma-sprayed beryllium for ITER

    SciTech Connect

    Castro, R.G.; Stanek, P.W.; Elliott, K.E.; Youchison, D.L.; Watson, R.D.; Walsh, D.S.

    1995-12-31

    Plasma-spray technology is under investigation as a method for producing high thermal conductivity beryllium coatings for use in magnetic fusion applications. Recent investigations have focused on optimizing the plasma-spray process for depositing beryllium coatings on damaged beryllium surfaces. Of particular interest has been optimizing the processing parameters to maximize the through-thickness thermal conductivity of the beryllium coatings. Experimental results will be reported on the use of secondary H{sub 2} gas additions to improve the melting of the beryllium powder and negative transferred-arc cleaning to prepare beryllium surfaces prior to depositing beryllium. Information will also b presented on thermal fatigue tests which were performed on beryllium coated ISX-B beryllium limiter tiles using 10 sec cycle times with 60 sec cooldowns and an International Thermonuclear Experimental Reactor (ITER) relevant divertor heat flux slightly in excess of 5 MW/m{sup 2}.

  7. Impact of Hight Velocity Cold Spray Particles

    SciTech Connect

    Dykhuizen, R.C.; Gilmore, D.L.; Jiang, X.; Neiser, R.A.; Sampath, S.; Smith, M.F.

    1998-12-01

    This paper presents experimental data and an computational model of the cold spray solid particle impact process. Copper particles impacting onto a polished stainless steel substrate are examined. The high velocity impact causes significant plastic deformation of both the particle and the sub- strate, but no melting is observed. The plastic deformation exposes clean surfaces that, under the high impact pressures, result in significant bond strengths between the particle and substrate. Experimental measurements of the splat and crater sizes compare well with the numerical calculations. It is shown that the crater depth is significant and increases with impact velocity. However, the splat diameter is much less sensitive to the impact velocity. It is also shown that the geometric lengths of the splat and crater scale linearly with the diameter of the impacting particle. It is hoped that the results presented will allow better understanding of the bonding process during cold spray.

  8. Spray combustion experiments and numerical predictions

    SciTech Connect

    Mularz, E.J.; Bulzan, D.L.; Chen, K.

    1993-01-01

    The next generation of commercial aircraft will include turbofan engines with performance significantly better than those in the current fleet. Control of particulate and gaseous emissions will also be an integral part of the engine design criteria. These performance and emission requirements present a technical challenge for the combustor: control of the fuel and air mixing and control of the local stoichiometry will have to be maintained much more rigorously than with combustors in current production. A better understanding of the flow physics of liquid fuel spray combustion is necessary. This paper describes recent experiments on spray combustion where detailed measurements of the spray characteristics were made, including local drop-size distributions and velocities. Also, an advanced combustor CFD code has been under development and predictions from this code are compared with experimental results. Studies such as these will provide information to the advanced combustor designer on fuel spray quality and mixing effectiveness. Validation of new fast, robust, and efficient CFD codes will also enable the combustor designer to use them as additional design tools for optimization of combustor concepts for the next generation of aircraft engines.

  9. Spray combustion experiments and numerical predictions

    NASA Technical Reports Server (NTRS)

    Mularz, Edward J.; Bulzan, Daniel L.; Chen, Kuo-Huey

    1993-01-01

    The next generation of commercial aircraft will include turbofan engines with performance significantly better than those in the current fleet. Control of particulate and gaseous emissions will also be an integral part of the engine design criteria. These performance and emission requirements present a technical challenge for the combustor: control of the fuel and air mixing and control of the local stoichiometry will have to be maintained much more rigorously than with combustors in current production. A better understanding of the flow physics of liquid fuel spray combustion is necessary. This paper describes recent experiments on spray combustion where detailed measurements of the spray characteristics were made, including local drop-size distributions and velocities. Also, an advanced combustor CFD code has been under development and predictions from this code are compared with experimental results. Studies such as these will provide information to the advanced combustor designer on fuel spray quality and mixing effectiveness. Validation of new fast, robust, and efficient CFD codes will also enable the combustor designer to use them as additional design tools for optimization of combustor concepts for the next generation of aircraft engines.

  10. Improved Orifice Plate for Spray Gun

    NASA Technical Reports Server (NTRS)

    Cunningham, W.

    1986-01-01

    Erratic spray pattern of commercial spray gun changed to repeatable one by simple redesign of two parts. In modified spray gun orifice plate and polytetrafluoroethylene bushing redesigned to assure centering and alignment with nozzle. Such improvement useful in many industrial applications requiring repeatable spray patterns. Might include spraying of foam insulation, paint, other protective coatings, detergents, abrasives, adhesives, process chemicals, or fuels. Unmodified spray gun produces erratic spray because lateral misalignment between orifice plate and nozzle.

  11. Improved Orifice Plate for Spray Gun

    NASA Technical Reports Server (NTRS)

    Cunningham, W.

    1986-01-01

    Erratic spray pattern of commercial spray gun changed to repeatable one by simple redesign of two parts. In modified spray gun orifice plate and polytetrafluoroethylene bushing redesigned to assure centering and alignment with nozzle. Such improvement useful in many industrial applications requiring repeatable spray patterns. Might include spraying of foam insulation, paint, other protective coatings, detergents, abrasives, adhesives, process chemicals, or fuels. Unmodified spray gun produces erratic spray because lateral misalignment between orifice plate and nozzle.

  12. Optimisation of a vertical spray boom for greenhouse spraying applications.

    PubMed

    Nuyttens, D; Windey, S; Braekman, P; De Moor, A; Sonck, B

    2003-01-01

    The European Crop Protection Association (ECPA) and CLO-DVL joined forces in a project to stimulate a safe use of pesticides in Southern European countries. CLO-DVL optimised a method with mineral chelates to evaluate deposition tests. This quantitative method to evaluate spray deposits and to check spray distributions is used to assess two novel spraying techniques. Deposition tests with water-sensitive paper and mainly with the manganese and molybdenum chelates as tracer elements were performed with a manually pulled trolley and a motorised vehicle both equipped with vertical spray booms. Filter papers were attached to the tomato and pepper plants at several heights to obtain an indication of the spray distribution in the crop. Particular attention was paid to the effect on the spray distribution of the vertical nozzle distance (35 cm vs. 50 cm) and the spray distance to the crop. The tests proved that a nozzle spacing of 35 cm delivers a much better spray distribution than one of 50 cm. The optimal spray distance for flat fan nozzles with a spray angle of 80 degrees and a nozzle spacing of 35 cm is about 30 cm.

  13. Sealing of thermal spray coatings by impregnation

    NASA Astrophysics Data System (ADS)

    Knuuttila, J.; Sorsa, P.; Mäntylä, T.; Knuuttila, J.; Sorsa, P.

    1999-06-01

    Results from the sealing of porosity by impregnation show that below a certain wetting angle of the sealant, high penetration depths are achieved. However, only sealants with very low curing shrinkages can prevent the transport of electrolyte through the coating. Various sealant types and impregnation methods are discussed, and factors influencing impregnation and sealing ability of sealants are reviewed. Experimental results from the sealing of plasma-sprayed aluminum-oxide coatings are presented.

  14. [Ethyl chloride aerosol spray for local anesthesia before arterial puncture: randomized placebo-controlled trial].

    PubMed

    Ballesteros-Peña, Sendoa; Fernández-Aedo, Irrintzi; Vallejo-De la Hoz, Gorka

    2017-06-01

    To compare the efficacy of an ethyl chloride aerosol spray to a placebo spray applied in the emergency department to the skin to reduce pain from arterial puncture for blood gas analysis. Single-blind, randomized placebo-controlled trial in an emergency department of Hospital de Basurto in Bilbao, Spain. We included 126 patients for whom arterial blood gas analysis had been ordered. They were randomly assigned to receive application of the experimental ethyl chloride spray (n=66) or a placebo aerosol spray of a solution of alcohol in water (n=60). The assigned spray was applied just before arterial puncture. The main outcome variable was pain intensity reported on an 11-point numeric rating scale. The median (interquartile range) pain level was 2 (1-5) in the experimental arm and 2 (1-4.5) in the placebo arm (P=.72). Topical application of an ethyl chloride spray did not reduce pain caused by arterial puncture.

  15. Flame spraying of polymers

    SciTech Connect

    Varacalle, D.J. Jr.; Zeek, D.P.; Couch, K.W.; Benson, D.M.; Kirk, S.M.

    1997-08-01

    Statistical design-of-experiment studies of the thermal spraying of polymer powders are presented. Studies of the subsonic combustion (i.e., Flame) process were conducted in order to determine the quality and economics of polyester and urethane coatings. Thermally sprayed polymer coatings are of interest to several industries for anticorrosion applications, including the chemical, automotive, and aircraft industries. In this study, the coating design has been optimized for a site-specific application using Taguchi-type fractional-factorial experiments. Optimized coating designs are presented for the two powder systems. A substantial range of thermal processing conditions and their effect on the resultant polymer coatings is presented. The coatings were characterized by optical metallography, hardness testing, tensile testing, and compositional analysis. Characterization of the coatings yielded the thickness, bond strength, Knoop microhardness, roughness, deposition efficiency, and porosity. Confirmation testing was accomplished to verify the coating designs.

  16. Spray Nozzle Calibrations

    DTIC Science & Technology

    1986-01-01

    1984. The manuscript was submitted for publication on October 2, 1985. AEOC-TR-85-eO CONTENTS Page J.O INTRODUCTION 1.1 General 5 1.2...1.1 GENERAL The formation of ice on aircraft surfaces occurs during flight through clouds of supercooled water droplets. Ice accretion on these... wind tunnel. Both the LWC and mean effective droplet size are set and maintained through variations in the water and air supply pressures of the spray

  17. Spray combustion stability project

    NASA Technical Reports Server (NTRS)

    Jeng, San-Mou; Litchford, Ron J.

    1990-01-01

    This report summarizes research activity on the Spray Combustion Stability Project, characterizes accomplishments and current status, and discusses projected future work. The purpose is to provide a concise conceptual overview of the research effort so the reader can quickly assimilate the gist of the research results and place them within the context of their potential impact on liquid rocket engine design technology. Therefore, this report does not elaborate on many of the detailed technical aspects of the research program.

  18. Vacuum plasma spray coating

    NASA Technical Reports Server (NTRS)

    Holmes, Richard R.; Mckechnie, Timothy N.

    1989-01-01

    Currently, protective plasma spray coatings are applied to space shuttle main engine turbine blades of high-performance nickel alloys by an air plasma spray process. Originally, a ceramic coating of yttria-stabilized zirconia (ZrO2.12Y2O3) was applied for thermal protection, but was removed because of severe spalling. In vacuum plasma spray coating, plasma coatings of nickel-chromium-aluminum-yttrium (NiCrAlY) are applied in a reduced atmosphere of argon/helium. These enhanced coatings showed no spalling after 40 MSFC burner rig thermal shock cycles between 927 C (1700 F) and -253 C (-423 F), while current coatings spalled during 5 to 25 test cycles. Subsequently, a process was developed for applying a durable thermal barrier coating of ZrO2.8Y2O3 to the turbine blades of first-stage high-pressure fuel turbopumps utilizing the enhanced NiCrAlY bond-coating process. NiCrAlY bond coating is applied first, with ZrO2.8Y2O3 added sequentially in increasing amounts until a thermal barrier coating is obtained. The enchanced thermal barrier coating has successfully passed 40 burner rig thermal shock cycles.

  19. Experimental investigation on electrical characteristics and dose measurement of dielectric barrier discharge plasma device used for therapeutic application

    NASA Astrophysics Data System (ADS)

    Shahbazi Rad, Zahra; Abbasi Davani, Fereydoun

    2017-04-01

    In this research, a Dielectric Barrier Discharge (DBD) plasma device operating in air has been made. The electrical characteristics of this device like instantaneous power, dissipated power, and discharge capacitance have been measured. Also, the effects of applied voltage on the dissipated power and discharge capacitance of the device have been investigated. The determination of electrical parameters is important in DBD plasma device used in living tissue treatment for choosing the proper treatment doses and preventing the destructive effects. The non-thermal atmospheric pressure DBD plasma source was applied for studying the acceleration of blood coagulation time, in vitro and wound healing time, in vivo. The citrated blood drops coagulated within 5 s treatment time by DBD plasma. The effects of plasma temperature and electric field on blood coagulation have been studied as an affirmation of the applicability of the constructed device. Also, the effect of constructed DBD plasma on wound healing acceleration has been investigated.

  20. Airborne manufactured nano-objects released from commercially available spray products: temporal and spatial influences.

    PubMed

    Bekker, Cindy; Brouwer, Derk H; van Duuren-Stuurman, Birgit; Tuinman, Ilse L; Tromp, Peter; Fransman, Wouter

    2014-01-01

    This paper reports a study of the dispersion of manufactured nano-objects (MNOs) through the air, both in time and space, during the use of two commercially available nano-spray products and comparable products without MNOs. The main objective was to identify whether personal exposure can occur at a greater distance than the immediate proximity of the source (>1 m from the source), that is, in the "far field" (bystanders), or at a period after the emission occurred (re-entry). The spray experiments were conducted in an experimental room with well-controlled environmental and ventilation conditions (19.5 m(3)). The concentration of MNOs was investigated by measuring real-time size distribution, number, and active surface area concentration. For off-line analysis of the particles in the air, samples for scanning/transmission electron microscopy and elemental analysis were collected. The release of MNOs was measured at ∼30 and 290 cm from the source ("near field" and "far field", respectively). For all four spray products, the maximum number and surface area concentrations in the "near field" exceeded the maximum concentrations reached in the "far field". At 2 min after the emission occurred, the concentration in both the "near field" and "far field" reached a comparable steady-state level above background level. These steady-state concentrations remained elevated above background concentration throughout the entire measurement period (12 min). The results of the real-time measurement devices mainly reflect the liquid aerosols emitted by the spray process itself rather than only the MNO, which hampers the interpretation of the results. However, the combination of the off-line analysis and the results of the real-time devices indicates that after the use of nano-spray products, personal exposure to MNOs can occur not only in the near field, but also at a greater distance than the immediate proximity of the source and at a period after emission occurred.

  1. ENTRAINMENT BY LIGAMENT-CONTROLLED EFFERVESCENT ATOMIZER-PRODUCED SPRAYS

    EPA Science Inventory

    Entrainment of ambient air into sprays produced by a new type of effervescent atomizer is reported. Entrainment data were obtained using a device similar to that described by Ricou & Spalding (1961). Entrainment data were analyzed using the model of Bush & Sojka (1994), in concer...

  2. ENTRAINMENT BY LIGAMENT-CONTROLLED EFFERVESCENT ATOMIZER-PRODUCED SPRAYS

    EPA Science Inventory

    Entrainment of ambient air into sprays produced by a new type of effervescent atomizer is reported. Entrainment data were obtained using a device similar to that described by Ricou & Spalding (1961). Entrainment data were analyzed using the model of Bush & Sojka (1994), in concer...

  3. Fundamental studies of spray combustion

    SciTech Connect

    Li, S.C.; Libby, P.A.; Williams, F.A.

    1997-12-31

    Our research on spray combustion involves both experiment and theory and addresses the characteristics of individual droplets and of sprays in a variety of flows: laminar and turbulent, opposed and impinging. Currently our focus concerns water and fuel sprays in two stage laminar flames, i.e., flames arising, for example from a stream of fuel and oxidizer flowing opposite to an air stream carrying a water spray. Our interest in these flames is motivated by the goals of reducing pollutant emissions and extending the range of stable spray combustion. There remains considerable research to be carried out in order to achieve these goals. Thus far our research on the characteristics of sprays in turbulent flows has been limited to nonreacting jets impinging on a plate but this work will be extended to opposed flows with and without a flame. In the following we discuss details of these studies and our plans for future work.

  4. Quantitative optical techniques for dense sprays investigation: A survey

    NASA Astrophysics Data System (ADS)

    Coghe, A.; Cossali, G. E.

    2012-01-01

    The experimental study of dense sprays by optical techniques poses many challenges and no methods have proven to be completely reliable when accurate quantitative data are required, for example to validate breakup models and CFD simulations. The present survey is aimed to a critical analysis of optical techniques capable to provide quantitative and reliable data in dense sprays and to point out the conditions necessary to safely obtain such measurements. A single parameter, the optical depth, is proposed to quantify the concept of dense spray and to indicate when multiple scattering becomes predominant and could make the experimental results questionable. Many available optical techniques are divided into two categories: the "classical" ones, like PDA, LDV, PIV, etc., that work well in dilute sprays but show many limitations in dense sprays, and the "emerging" ones more suitable for dense sprays. Among the last ones, those considered more promising are discussed in detail. A number of significant applications are also presented and discussed to better clarify the nature of such complex problem and the feasibility of the new proposed approaches.

  5. Spray Characterization of Gas-to-Liquid Synthetic Jet Fuels

    NASA Astrophysics Data System (ADS)

    Kannaiyan, Kumaran; Sadr, Reza; GTL jet fuel Consortium Team

    2012-11-01

    Gas-to-Liquid (GTL) Synthetic Paraffinic Kerosene (SPK) fuel obtained from Fischer-Tropsch synthesis has grabbed the global attention due to its cleaner combustion characteristics. GTL fuels are expected to meet the vital qualities such as atomization, combustion and emission characteristics of conventional jet fuels. It is imperative to understand fuel atomization in order to gain insights on the combustion and emission aspects of an alternative fuel. In this work spray characteristics of GTL-SPK, which could be used as a drop-in fuel in aircraft gas turbine engines, is studied. This work outlines the spray experimental facility, the methodology used and the results obtained using two SPK's with different chemical compositions. The spray characteristics, such as droplet size and distribution, are presented at three differential pressures across a simplex nozzle and compared with that of the conventional Jet A-1 fuel. Experimental results clearly show that although the chemical composition is significantly different between SPK's, the spray characteristics are not very different. This could be attributed to the minimal difference in fluid properties between the SPK's. Also, the spray characteristics of SPK's show close resemblance to the spray characteristics of Jet A-1 fuel.

  6. A spray-suppression model for turbulent combustion

    SciTech Connect

    DESJARDIN,PAUL E.; TIESZEN,SHELDON R.; GRITZO,LOUIS A.

    2000-02-14

    A spray-suppression model that captures the effects of liquid suppressant on a turbulent combusting flow is developed and applied to a turbulent diffusion flame with water spray suppression. The spray submodel is based on a stochastic separated flow approach that accounts for the transport and evaporation of liquid droplets. Flame extinguishment is accounted for by using a perfectly stirred reactor (PSR) submodel of turbulent combustion. PSR pre-calculations of flame extinction times are determined using CHEMKIN and are compared to local turbulent time scales of the flow to determine if local flame extinguishment has occurred. The PSR flame extinguishment and spray submodels are incorporated into Sandia's flow fire simulation code, VULCAN, and cases are run for the water spray suppression studies of McCaffrey for turbulent hydrogen-air jet diffusion flames. Predictions of flame temperature decrease and suppression efficiency are compared to experimental data as a function of water mass loading using three assumed values of drop sizes. The results show that the suppression efficiency is highly dependent on the initial droplet size for a given mass loading. A predicted optimal suppression efficiency was observed for the smallest class of droplets while the larger drops show increasing suppression efficiency with increasing mass loading for the range of mass loadings considered. Qualitative agreement to the experiment of suppression efficiency is encouraging, however quantitative agreement is limited due to the uncertainties in the boundary conditions of the experimental data for the water spray.

  7. Closed loop spray cooling apparatus

    NASA Technical Reports Server (NTRS)

    Alger, D. L.; Schwab, W. B.; Furman, E. R. (Inventor)

    1979-01-01

    A closed loop apparatus for jet spraying coolant against the back of a radiation target is described. The coolant is circulated through a closed loop with a bubble of inert gas being maintained around the spray. Mesh material is disposed between the bubble and the surface of the liquid coolant which is below the bubble at a predetermined level. In a second arrangement no inert gas is used, the bubble consists of vapor produced when the coolant is sprayed against the target.

  8. Design, development and experimental validation of a non-invasive device for recording respiratory events during bottle feeding.

    PubMed

    Cavaiola, C; Tamilia, E; Massaroni, C; Morbidoni, G; Schena, E; Formica, D; Taffoni, F

    2014-01-01

    In newborns, a poor coordination between sucking, swallowing and breathing may undermine the effectiveness of oral feeding and signal immaturity of Central Nervous System. The aim of this work is to develop and validate a non-invasive device for recording respiratory events of newborns during bottle feeding. The proposed device working principle is based on the convective heat exchanged between two hot bodies and the infants' breathing. The sensing elements are inserted into a duct and the gas exchanged by infants is conveyed into this duct thanks to an ad hoc designed system to be mounted on a commercial feeding bottle. Two sets of experiments have been carried out in order to investigate the discrimination threshold of the device and characterize the sensor response at oscillating flows. The effect of distance and tilt between nostrils and device, and the breathing frequency, have been investigated simulating nostrils and neonatal respiratory pattern. The device has a discrimination threshold lower than 0.5 L/min at both 10° and 20° of tilt. Distance for these two settings does not affect the threshold in the investigated range (10-20 mm). Moreover, the device is able to detect breathing events, and to discriminate the onset of expiratory phase, during a neonatal respiratory task delivered by a lung simulator. The results foster the successful application of this device to the assessment of the temporal breathing pattern of newborns during bottle feeding with a non-invasive approach.

  9. Detachment of sprayed colloidal copper oxychloride-metalaxyl fungicides by a shallow water flow.

    PubMed

    Pose-Juan, Eva; Paradelo-Pérez, Marcos; Rial-Otero, Raquel; Simal-Gándara, Jesus; López-Periago, José E

    2009-06-01

    Flow shear stress induced by rainfall promotes the loss of the pesticides sprayed on crops. Some of the factors influencing the losses of colloidal-size particulate fungicides are quantified by using a rotating shear system model. With this device it was possible to analyse the flow shear influencing washoff of a commercial fungicide formulation based on a copper oxychloride-metalaxyl mixture that was sprayed on a polypropylene surface. A factor plan with four variables, i.e. water speed and volume (both variables determining flow boundary stress in the shear device), formulation dosage and drying temperature, was set up to monitor colloid detachment. This experimental design, together with sorption experiments of metalaxyl on copper oxychloride, and the study of the dynamics of metalaxyl and copper oxychloride washoff, made it possible to prove that metalaxyl washoff from a polypropylene surface is controlled by transport in solution, whereas that of copper oxychloride occurs by particle detachment and transport of particles. Average losses for metalaxyl and copper oxychloride were, respectively, 29 and 50% of the quantity applied at the usual recommended dosage for crops. The key factors affecting losses were flow shear and the applied dosage. Empirical models using these factors provided good estimates of the percentage of fungicide loss. From the factor analysis, the main mechanism for metalaxyl loss induced by a shallow water flow is solubilisation, whereas copper loss is controlled by erosion of copper oxychloride particles.

  10. Spray printing of organic semiconducting single crystals

    PubMed Central

    Rigas, Grigorios-Panagiotis; Payne, Marcia M.; Anthony, John E.; Horton, Peter N.; Castro, Fernando A.; Shkunov, Maxim

    2016-01-01

    Single-crystal semiconductors have been at the forefront of scientific interest for more than 70 years, serving as the backbone of electronic devices. Inorganic single crystals are typically grown from a melt using time-consuming and energy-intensive processes. Organic semiconductor single crystals, however, can be grown using solution-based methods at room temperature in air, opening up the possibility of large-scale production of inexpensive electronics targeting applications ranging from field-effect transistors and light-emitting diodes to medical X-ray detectors. Here we demonstrate a low-cost, scalable spray-printing process to fabricate high-quality organic single crystals, based on various semiconducting small molecules on virtually any substrate by combining the advantages of antisolvent crystallization and solution shearing. The crystals' size, shape and orientation are controlled by the sheer force generated by the spray droplets' impact onto the antisolvent's surface. This method demonstrates the feasibility of a spray-on single-crystal organic electronics. PMID:27874001

  11. Spray printing of organic semiconducting single crystals.

    PubMed

    Rigas, Grigorios-Panagiotis; Payne, Marcia M; Anthony, John E; Horton, Peter N; Castro, Fernando A; Shkunov, Maxim

    2016-11-22

    Single-crystal semiconductors have been at the forefront of scientific interest for more than 70 years, serving as the backbone of electronic devices. Inorganic single crystals are typically grown from a melt using time-consuming and energy-intensive processes. Organic semiconductor single crystals, however, can be grown using solution-based methods at room temperature in air, opening up the possibility of large-scale production of inexpensive electronics targeting applications ranging from field-effect transistors and light-emitting diodes to medical X-ray detectors. Here we demonstrate a low-cost, scalable spray-printing process to fabricate high-quality organic single crystals, based on various semiconducting small molecules on virtually any substrate by combining the advantages of antisolvent crystallization and solution shearing. The crystals' size, shape and orientation are controlled by the sheer force generated by the spray droplets' impact onto the antisolvent's surface. This method demonstrates the feasibility of a spray-on single-crystal organic electronics.

  12. Spray printing of organic semiconducting single crystals

    NASA Astrophysics Data System (ADS)

    Rigas, Grigorios-Panagiotis; Payne, Marcia M.; Anthony, John E.; Horton, Peter N.; Castro, Fernando A.; Shkunov, Maxim

    2016-11-01

    Single-crystal semiconductors have been at the forefront of scientific interest for more than 70 years, serving as the backbone of electronic devices. Inorganic single crystals are typically grown from a melt using time-consuming and energy-intensive processes. Organic semiconductor single crystals, however, can be grown using solution-based methods at room temperature in air, opening up the possibility of large-scale production of inexpensive electronics targeting applications ranging from field-effect transistors and light-emitting diodes to medical X-ray detectors. Here we demonstrate a low-cost, scalable spray-printing process to fabricate high-quality organic single crystals, based on various semiconducting small molecules on virtually any substrate by combining the advantages of antisolvent crystallization and solution shearing. The crystals' size, shape and orientation are controlled by the sheer force generated by the spray droplets' impact onto the antisolvent's surface. This method demonstrates the feasibility of a spray-on single-crystal organic electronics.

  13. Photomicrographic Studies of Fuel Sprays

    NASA Technical Reports Server (NTRS)

    Lee, Dana W; Spencer, Robert C

    1934-01-01

    A large number of photomicrographs of fuel sprays were taken for the purpose of studying the spray structure and the process of spray formation. They were taken at magnifying powers of 2.5, 3.25, and 10, using a spark discharge of very short duration for illumination. Several types and sizes of nozzles were investigated, different liquids were used, and a wide range of injection pressures was employed. The sprays were photographed as they were injected into a glass-walled chamber in which the air density was varied from 14 atmospheres to 0.0013 atmosphere.

  14. Vacuum Plasma Spraying Replaces Electrodeposition

    NASA Technical Reports Server (NTRS)

    Holmes, Richard R.; Power, Chris; Burns, David H.; Daniel, Ron; Mckechnie, Timothy N.

    1992-01-01

    Vacuum plasma spraying used to fabricate large parts with complicated contours and inner structures, without uninspectable welds. Reduces time, and expense of fabrication. Wall of combustion chamber built up inside of outer nickel-alloy jacket by plasma spraying. Particles of metal sprayed partially melted in plasma gun and thrown at supersonic speed toward deposition surface. Vacuum plasma-spray produces stronger bond between the grooves and covering layer completing channels and wall of combustion chamber. In tests, bond withstood pressure of 20 kpsi, three times allowable limit by old method.

  15. Pharmaceutical Particle Engineering via Spray Drying

    PubMed Central

    2007-01-01

    This review covers recent developments in the area of particle engineering via spray drying. The last decade has seen a shift from empirical formulation efforts to an engineering approach based on a better understanding of particle formation in the spray drying process. Microparticles with nanoscale substructures can now be designed and their functionality has contributed significantly to stability and efficacy of the particulate dosage form. The review provides concepts and a theoretical framework for particle design calculations. It reviews experimental research into parameters that influence particle formation. A classification based on dimensionless numbers is presented that can be used to estimate how excipient properties in combination with process parameters influence the morphology of the engineered particles. A wide range of pharmaceutical application examples—low density particles, composite particles, microencapsulation, and glass stabilization—is discussed, with specific emphasis on the underlying particle formation mechanisms and design concepts. PMID:18040761

  16. Experimental study of the performance of a very small repetitive plasma focus device in different working conditions

    NASA Astrophysics Data System (ADS)

    Goudarzi, S.; Babaee, H.; Esmaeli, A.; Nasiri, A.

    2017-01-01

    SORENA-1 is a very small repetitive Mather-type plasma focus device (20 J) that can operate at frequencies up to 1 Hz. This device has been designed and constructed in the Plasma and Nuclear Fusion Research School of the Nuclear Science and Technology Research Institute of Iran. In this article, the structure of SORENA-1 is described and results of experiments with Ar, Ne, and D2 working gases at several discharge voltages and initial pressures are presented and analyzed.

  17. An experimental canine patent ductus arteriosus occlusion device based on shape memory polymer foam in a nitinol cage.

    PubMed

    Wierzbicki, Mark A; Raines, Sarah B; Gordon, Sonya G; Criscione, John C; Saunders, Ashley B; Birch, Scott; Due, Bradley; Keller, Brandis; Nash, Landon D; Miller, Matthew W; Maitland, Duncan J

    2017-07-25

    Patent ductus arteriosus (PDA) is a congenital cardiovascular defect in which a fetal connection between the aorta and pulmonary artery does not spontaneously close shortly after birth. If left uncorrected serious complications and even death can occur. Surgical ligation is the traditional treatment method; however, it is an invasive procedure, that motivates development of a minimally invasive option. Shape memory polymer (SMP) foams are unique materials that hold promise in the field of minimally invasive occlusion devices. In this work, a prototype nitinol foam cage (NFC) incorporating SMP foams has been designed and evaluated in multiple mechanical and in vitro verification tests. The NFC demonstrated acceptable fatigue resistance in a preliminary strut integrity test, withstanding one million cycles without complete strut fracture. Radial force analysis of both thick- and thin-walled prototype variations generated less vessel distension and wall tension in a vessel mimic compared to a commercial device. The NFCs exhibited negligible in vitro migration, comparable to that of a commercial device, using simplified, ideal models of PDA. Deployment characteristics of the prototypes were evaluated and compared to that of a commercial device when delivered into physiological models of PDA. During mock deployments, a veterinary cardiologist noted that, while deliverable, the thin-walled NFC prototype exhibited poor deployment characteristics, however the thick-walled NFC had deployment characteristics comparable to that of a commercial device. The promising results of this study warrant further investigation of the NFC device for canine PDA closure. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Shape optimization for the subsidence resistance of an interbody device using simulation-based genetic algorithms and experimental validation.

    PubMed

    Hsu, Ching-Chi

    2013-07-01

    Subsidence of interbody devices into the vertebral body might result in serious clinical problems, especially when the devices are not well designed and analyzed. Recently, some novel designs were proposed to reduce the risk of subsidence, but those designs are based on the researcher's experience. The purpose of this study was to discover the interbody device design with excellent subsidence resistance by changing the device's shape. The three-dimensional nonlinear finite element models, which consisted of the interbody device and vertebral body, were created first. Then, the simulation-based genetic algorithm, which combined the finite element model and the searching algorithm, was developed by using ANSYS® Parametric Design Language. Finally, the numerical results were carefully validated with the use of biomechanical tests. The optimum shape design obtained in this study looks like a flower with many petals and it has excellent subsidence resistance when compared with the other designs provided by the past studies. The results of the present study could help surgeons to understand the subsidence resistance of interbody devices in terms of their shapes and has directly provided the design rationales to engineers.

  19. [Target infrared detection in target spray].

    PubMed

    Deng, Wei; He, Xiong-kui; Zhang, Lu-da; Zeng, Ai-jun; Song, Jian-li; Zou, Jian-jun

    2008-10-01

    Crops in agriculture and forestry are normally planted discretely. The chemical sprayed between crops would cause great waste and serious environment pollution. Therefore realization of the precision spray has great significance. This research discussed the method to realize automatic target detection using infrared detect technology. The infrared can avoid the interference of the visible light effectively and the response speed is very fast. Therefore it can be used to implement non-tough detection. Photoelectric detection systems based on infrared detect technology are normally stable, reliable, low cost, simple structure, and easy to be practically utilized. Therefore it is widely used in the on-line real time detection field. Its key point is to determinate the characteristic wavelength or wave band. The infrared lights emitted from the infrared light emitting diode were irradiated to the detected objects. The reflected infrared lights could be received by the photoelectric device. Then control signal was triggered and automatic target spray was realized. Code-division infrared detection circuit was used in the system. Modulated pulse infrared signals using different coding were used in different photodetector units in the built system so as to eliminate the light path interference between different detector units and other light signal interferences. Therefore the interference capacity of the system is high. The test results showed that the automatic target spray equipment set up in the study could detect crop targets automatically. The light wavelength used in the test is 850 nm. The detection range was tunable within 0.1-0.5 m. The least targets detectable distance was less than 0.3 m.

  20. Lessons learned from a double-blind randomised placebo-controlled study with a iota-carrageenan nasal spray as medical device in children with acute symptoms of common cold.

    PubMed

    Fazekas, Tamas; Eickhoff, Philipp; Pruckner, Nathalie; Vollnhofer, Georg; Fischmeister, Gustav; Diakos, Christopher; Rauch, Margit; Verdianz, Maria; Zoubek, Andreas; Gadner, Helmut; Lion, Thomas

    2012-09-05

    Common cold is caused by a variety of respiratory viruses. The prevalence in children is high, and it potentially contributes to significant morbidity. Iota-carragenan, a polymer derived from red seaweed, has reduced viral load in nasal secretions and alleviated symptoms in adults with common cold. We have assessed the antiviral and therapeutic activity of a nasal spray containing iota-carrageenan in children with acute symptoms of common cold. A cohort of 153 children between 1-18 years (mean age 5 years), displaying acute symptoms of common cold were randomly assigned to treatment with a nasal spray containing iota-carrageenan (0.12%) as verum or 0.9% sodium chloride solution as placebo for seven days. Symptoms of common cold were recorded and the viral load of respiratory viruses in nasal secretions was determined at two consecutive visits. The results of the present study showed no significant difference between the iota carrageenan and the placebo group on the mean of TSS between study days 2-7. Secondary endpoints, such as reduced time to clearance of disease (7.6 vs 9.4 days; p = 0.038), reduction of viral load (p = 0.026), and lower incidence of secondary infections with other respiratory viruses (p = 0.046) indicated beneficial effects of iota-carrageenan in this population. The treatment was safe and well tolerated, with less side effects observed in the verum group compared to placebo. In this study iota-carrageenan did not alleviate symptoms in children with acute symptoms of common cold, but significantly reduced viral load in nasal secretions that may have important implications for future studies. ISRCTN52519535, http://www.controlled-trials.com/ISRCTN52519535/

  1. Lessons learned from a double-blind randomised placebo-controlled study with a iota-carrageenan nasal spray as medical device in children with acute symptoms of common cold

    PubMed Central

    2012-01-01

    Background Common cold is caused by a variety of respiratory viruses. The prevalence in children is high, and it potentially contributes to significant morbidity. Iota-carragenan, a polymer derived from red seaweed, has reduced viral load in nasal secretions and alleviated symptoms in adults with common cold. Methods We have assessed the antiviral and therapeutic activity of a nasal spray containing iota-carrageenan in children with acute symptoms of common cold. A cohort of 153 children between 1–18 years (mean age 5 years), displaying acute symptoms of common cold were randomly assigned to treatment with a nasal spray containing iota-carrageenan (0.12%) as verum or 0.9% sodium chloride solution as placebo for seven days. Symptoms of common cold were recorded and the viral load of respiratory viruses in nasal secretions was determined at two consecutive visits. Results The results of the present study showed no significant difference between the iota carrageenan and the placebo group on the mean of TSS between study days 2–7. Secondary endpoints, such as reduced time to clearance of disease (7.6 vs 9.4 days; p = 0.038), reduction of viral load (p = 0.026), and lower incidence of secondary infections with other respiratory viruses (p = 0.046) indicated beneficial effects of iota-carrageenan in this population. The treatment was safe and well tolerated, with less side effects observed in the verum group compared to placebo. Conclusion In this study iota-carrageenan did not alleviate symptoms in children with acute symptoms of common cold, but significantly reduced viral load in nasal secretions that may have important implications for future studies. Trial registration ISRCTN52519535, http://www.controlled-trials.com/ISRCTN52519535/ PMID:22950667

  2. Effects of spray drying on antioxidant capacity and anthocyanidin content of blueberry by-products.

    PubMed

    Lim, Kar; Ma, Mitzi; Dolan, Kirk D

    2011-09-01

    The effect of spray drying on degradation of nutraceutical components in cull blueberry extract was investigated. Samples collected before and after spray drying were tested for antioxidant capacity using oxygen radical absorbance capacity (ORAC(FL) ) and total phenolics; and for individual anthocyanidins. In Study 1, four different levels of maltodextrin (blueberry solids to maltodextrin ratios of 5: 95, 10: 90, 30: 70, and 50: 50) were spray dried a pilot-scale spray dryer. There was significantly higher retention of nutraceutical components with increased levels of maltodextrin indicating a protective effect of maltodextrin on the nutraceutical components during spray drying. In Study 2, the air inlet temperature of the spray dryer was kept constant for all runs at 150 °C, with 2 different outlet temperatures of 80 and 90 °C. The degradation of nutraceutical components was not significantly different at the 2 selected outlet temperatures. ORAC(FL) reduction for blueberry samples after spray drying was 66.3% to 69.6%. After spray drying, total phenolics reduction for blueberry was 8.2% to 17.5%. Individual anthocyanidin reduction for blueberry was 50% to 70%. The experimental spray dried powders compared favorably to commercial blueberry powders. Results of the study show that use of blueberry by-products is feasible to make a value-added powder. Results can be used by producers to estimate final nutraceutical content of spray-dried blueberry by-products. © 2011 Institute of Food Technologists®

  3. Evaporative cooling by a pulsed jet spray of binary ethanol-water mixture

    NASA Astrophysics Data System (ADS)

    Karpov, P. N.; Nazarov, A. D.; Serov, A. F.; Terekhov, V. I.

    2015-07-01

    We have experimentally studied the heat transfer under conditions of pulsed multinozzle jet spray impact onto a vertical surface. The working coolant fluid was aqueous ethanol solution in a range of concentrations K 1 = 0-96%. The duration of spray pulses was τ = 2, 4, and 10 ms at a repetition frequency of 10 Hz. The maximum heat transfer coefficient was achieved at an ethanol solution concentration within 50-60%. The thermal efficiency of pulsed spray cooling grows with increasing ethanol concentration and decreasing jet spray pulse duration.

  4. Flow field of a hollow-cone spray in a coflowing airstream

    NASA Astrophysics Data System (ADS)

    Coghe, A.; Cossali, G.; Gamma, F.

    An experimental investigation has been carried out on the flowfield of an isothermal hollow-cone spray generated by a swirl chamber pressure atomizer spraying water into a coflowing confined airstream. The study was limited to the near-field zone from 15 to 75 nozzle diameters, to verify the feasibility of providing the initial conditions required by numerical spray models. Laser Doppler velocimetry and visualization methods have been used to measure the mean and rms drop velocity components and the initial spray angle.

  5. Computational fluid dynamic analysis of a High-Velocity Oxygen-Fuel (HVOF) thermal spray torch

    SciTech Connect

    Hassan, B.; Oberkampf, W.L.; Neiser, R.A.; Roemer, T.J.

    1995-09-01

    The gas dynamics of a High-Velocity Oxygen-Fuel (HVOF) torch are analyzed using computational fluid dynamics (CFD) techniques. The thermal spray device analyzed is similar to a Metco Diamond Jet torch with powder feed. The injection nozzle is assumed to be axisymmetric with premixed fuel and oxygen fed from an annulus, and air cooling injected along the interior surface of the aircap. The aircap, a cronically converging nozzle, achieves choked flow conditions at the exit and a supersonic, under-expanded jet develops externally. Finite difference equations for mass, momentum, and energy conservation are solved for the gas dynamics. The combustion process is modeled using a single-step and a 12-step quasi-global finite-rate chemistry model with dissociation of the gas and a total of nine species. Turbulent flow inside the aircap and in the free-jet decay is modeled using a two-equation k-{epsilon} model. An iterative, implicit, finite volume numerical method is used to solve the gas dynamic equations inside and outside the torch . The CFD results are compared with recent experimental measurements of pressure inside the HVOF aircap. Comparisons are made for two flow rates of premixed fuel and oxygen and air cooling. This paper presents the first published comparisons of CFD predictions and experimental measurements for HVOF tbermal spraying.

  6. Tokamak plasma response to droplet spraying from melted plasma-facing components

    NASA Astrophysics Data System (ADS)

    Tokar, M. Z.; Coenen, J. W.; Philipps, V.; Ueda, Y.; TEXTOR Team

    2012-01-01

    High-Z materials such as tungsten are currently the potentially best candidates for plasma-facing components (PFCs) in future fusion devices. However, the threat of melting under uncontrolled conditions and the associated material redistribution and loss can place strict limits on the lifetime of PFCs and plasma operation conditions. In particular, material losses in the form of fine sprayed droplets can provide a very intensive source of impurities in the plasma core. In this paper, the plasma response to radiation losses from impurity particles produced by droplet evaporation is modelled for the conditions found in the tokamak TEXTOR. The interplay between tungsten spraying and plasma behaviour, resulting in the reduction of power transferred to the limiter and diminution of droplet production, is taken into account. Calculations predict, in agreement with experimental observations, that this evolution results in a new steady state with significantly reduced central temperature and peaked impurity radiation profile. The efficiency of melt conversion into droplets, estimated by comparing experimental and computed plasma temperatures, is in reasonable agreement with the predictions from models for droplet generation.

  7. Innovative bi-fluid atomizer inner flow characterization and outer spray diffusion analysis

    NASA Astrophysics Data System (ADS)

    Elzo, D.; Mazin, C.

    2012-11-01

    We developed an atomizer nozzle equipping a medical device used for airborne disinfection of medical rooms. The diffusion technology of the equipment is based on the spraying of fine liquid droplets of disinfectant into the volume to be treated. The liquid phase is expulsed thanks to an air assist atomizer we designed, which originality comes from the geometry we give to the throat of the micro-venturi, inner part of the atomizer nozzle. The micro-venturi throat is deviated of angle of 4° and will permit a homogeneous diffusion. We computed three dimensional numerical calculations of the inner compressible turbulent air flow through the atomizer we designed and compared the results obtained with the ones computed for a symmetrical atomizer. The modeling was done with the CFD codes STARCCM+ and Fluent, choosing the k-omega turbulent model. The modeling has been validated especially by one dimensional analytical calculations and experimental measurements of the mean axial velocity and mass flow rate circulating through the atomizer. Three dimensional numerical calculations show the vertical deviation of the flow at throat level and swirl effect generated by the deviated inner throat of the micro-venturi. These calculations allowed understanding the nature of the spray observed in experimental conditions, and the advantages to use a deviated micro-venturi throat. Indeed, micro bacteriological tests showed that the quality and the effectiveness of the diffusion are enhanced in comparison to equipments with a symmetrical micro-venturi.

  8. Experimental study on infusion devices containing polyvinyl chloride: to what extent are they di(2-ethylhexyl)phthalate-free?

    PubMed

    Genay, Stéphanie; Luciani, Chiara; Décaudin, Bertrand; Kambia, Nicolas; Dine, Thierry; Azaroual, Nathalie; Di Martino, Piera; Barthélémy, Christine; Odou, Pascal

    2011-06-30

    The use of medical devices containing highly criticized phthalates including di(2-ethylhexyl) phthalate (DEHP) has been challenged by European directive 2007/47/CE, put into effect in March 2010. New plasticizers are now being used to soften PVC in medical devices: trioctyltrimellitate (TOTM), di-isononyl-cyclohexan-1,2-dicarboxilate (DINCH) and di(2-ethylhexyl) terephthalate (DEHT). To quantify DEHP in nine DEHP-free medical devices made of PVC softened by alternative plasticizers, high performance liquid chromatography analysis with ultraviolet detection at 220 nm wavelength was achieved. An NMR spectroscopy was performed to confirm DEHP presence. Only two medical devices out of the nine tested were truly without DEHP. One of them showed traces of DEHP exceeding the threshold contamination of 0.1% in plastic mass set by REACH regulations. TOTM plasticizer is still incriminated when polyvinyl-chloride (PVC) is contaminated with DEHP. Manufacturers must verify the purity of their raw material, not only on PVC, but also on other soft plastics entering into the composition of medical infusion devices. The clinical consequences of exposure to certain levels of DEHP have not been evaluated. A solution could be to use alternative PVC-free materials.

  9. Spray algorithm without interface construction

    NASA Astrophysics Data System (ADS)

    Al-Kadhem Majhool, Ahmed Abed; Watkins, A. P.

    2012-05-01

    This research is aimed to create a new and robust family of convective schemes to capture the interface between the dispersed and the carrier phases in a spray without the need to build up the interface boundary. The selection of the Weighted Average Flux (WAF) scheme is due to this scheme being designed to deal with random flux scheme which is second-order accurate in space and time. The convective flux in each cell face utilizes the WAF scheme blended with Switching Technique for Advection and Capturing of Surfaces (STACS) scheme for high resolution flux limiters. In the next step, the high resolution scheme is blended with the WAF scheme to provide the sharpness and boundedness of the interface by using switching strategy. In this work, the Eulerian-Eulerian framework of non-reactive turbulent spray is set in terms of theoretical proposed methodology namely spray moments of drop size distribution, presented by Beck and Watkins [1]. The computational spray model avoids the need to segregate the local droplet number distribution into parcels of identical droplets. The proposed scheme is tested on capturing the spray edges in modelling hollow cone sprays without need to reconstruct two-phase interface. A test is made on simple comparison between TVD scheme and WAF scheme using the same flux limiter on convective flow hollow cone spray. Results show the WAF scheme gives a better prediction than TVD scheme. The only way to check the accuracy of the presented models is by evaluating the spray sheet thickness.

  10. A New Way to Spray

    NASA Technical Reports Server (NTRS)

    2000-01-01

    A NASA SBIR contract provided the funding for a new nozzle shape to be used in plasma spray techniques. The new design, a bell shape, reduces overspray. The result is a significant decrease in the cost of plasma spraying and a higher quality, more pure coating.

  11. Coaxial injector spray characterization using water/air as simulants

    NASA Technical Reports Server (NTRS)

    Zaller, Michelle M.; Klem, Mark D.

    1991-01-01

    Quantitative information about the atomization of injector sprays is required to improve the accuracy of computational models that predict the performance and stability of liquid propellant rocket engines. An experimental program is being conducted at NASA-Lewis to measure the drop size and velocity distributions in shear coaxial injector sprays. A phase/Doppler interferometer is used to obtain drop size data in water air shear coaxial injector sprays. Droplet sizes and axial component of droplet velocities are measured at different radii for various combinations of water flow rate, air flow rate, injector liquid jet diameter, injector annular gap, and liquid post recess. Sauter mean diameters measured in the spray center 51 mm downstream of the liquid post tip range from 28 to 68 microns, and mean axial drop velocities at the same location range from 37 to 120 m/s. The shear coaxial injector sprays show a high degree of symmetry; the mean drop size and velocity profiles vary with liquid flow rate, post recess, and distance from the injector face. The drop size data can be used to estimate liquid oxygen/hydrogen spray drop sizes by correcting property differences between water-air and liquid oxygen/hydrogen.

  12. Substrate system for spray forming

    DOEpatents

    Chu, Men G.; Chernicoff, William P.

    2002-01-01

    A substrate system for receiving a deposit of sprayed metal droplets including a movable outer substrate on which the sprayed metal droplets are deposited. The substrate system also includes an inner substrate disposed adjacent the outer substrate where the sprayed metal droplets are deposited on the outer substrate. The inner substrate includes zones of differing thermal conductivity to resist substrate layer porosity and to resist formation of large grains and coarse constituent particles in a bulk layer of the metal droplets which have accumulated on the outer substrate. A spray forming apparatus and associated method of spray forming a molten metal to form a metal product using the substrate system of the invention is also provided.

  13. Substrate system for spray forming

    DOEpatents

    Chu, Men G.; Chernicoff, William P.

    2000-01-01

    A substrate system for receiving a deposit of sprayed metal droplets including a movable outer substrate on which the sprayed metal droplets are deposited. The substrate system also includes an inner substrate disposed adjacent the outer substrate where the sprayed metal droplets are deposited on the outer substrate. The inner substrate includes zones of differing thermal conductivity to resist substrate layer porosity and to resist formation of large grains and coarse constituent particles in a bulk layer of the metal droplets which have accumulated on the outer substrate. A spray forming apparatus and associated method of spray forming a molten metal to form a metal product using the substrate system of the invention is also provided.

  14. ICLASS-85; Proceedings of the Third International Conference on Liquid Atomisation and Spray Systems, Imperial College of Science and Technology, London, England, July 8-10, 1985. Volumes 1 & 2

    NASA Astrophysics Data System (ADS)

    Eisenklam, P.; Yule, A.

    The theory, experimental investigation, and applications of liquid atomization and spraying are discussed in reviews and reports. Topics examined include atomizer design and performance, diesel and transient sprays, medical and pressure-pack aerosols, agricultural sprays, and the atomization of specialized fluids. Consideration is given to measurement and data-analysis techniques; spray structure, transfer processes, and combustion; the fundamentals of atomization and drop dynamics; and monosize sprays.

  15. Nozzleless Spray Cooling Using Surface Acoustic Waves

    NASA Astrophysics Data System (ADS)

    Ang, Kar Man; Yeo, Leslie; Friend, James; Hung, Yew Mun; Tan, Ming Kwang

    2015-11-01

    Due to its reliability and portability, surface acoustic wave (SAW) atomization is an attractive approach for the generation of monodispersed microdroplets in microfluidics devices. Here, we present a nozzleless spray cooling technique via SAW atomization with key advantage of downward scalability by simply increasing the excitation frequency. With generation of micron size droplets through surface destabilization using SAW, the clogging issues commonly encountered by spraying nozzle can be neutralized. Using deionised water, cooling is improved when the atomization rate is increased and the position of the device is optimized such that the atomized droplets can be easily seeded into the upstream of the flow circulation. Cooling is further improved with the use of nanofluids; a suspension of nanoparticles in water. By increasing nanoparticle mass concentration from 1% to 3%, cooling is enhanced due to the deposition and formation of nanoparticle clusters on heated surface and eventually increase the surface area. However, further increase the concentration to 10% reduces the cooling efficiency due to drastic increase in viscosity μ that leads to lower atomization rate which scales as ṁ ~μ - 1 / 2 .

  16. Oxidation in HVOF-sprayed steel

    SciTech Connect

    Smith, M.F.; Neiser, R.A.; Dykhuizen, R.C.

    1997-08-01

    It is widely held that most of the oxidation in thermally sprayed coatings occurs on the surface of the droplet after it has flattened. The evidence in this paper suggests that, for the conditions studied here, oxidation of the top surface of flattened droplets is not the dominant oxidation mechanism. In this study, a mild steel wire (AISI 1025) was sprayed using a high-velocity oxy-fuel (HVOF) torch onto copper and aluminum substrates. Ion milling and Auger spectroscopy were used to examine the distribution of oxides within individual splats. Conventional metallographic analysis was also used to study oxide distributions within coatings that were sprayed under the same conditions. An analytical model for oxidation of the exposed surface of a splat is presented. Based on literature data, the model assumes that diffusion of iron through a solid FeO layer is the rate limiting factor in forming the oxide on the top surface of a splat. An FeO layer only a few thousandths of a micron thick is predicted to form on the splat surface as it cools. However, the experimental evidence shows that the oxide layers are typically 100x thicker than the predicted value. These thick, oxide layers are not always observed on the top surface of a splat. Indeed, in some instances the oxide layer is on the bottom, and the metal is on the top. The observed oxide distributions are more consistently explained if most of the oxide formed before the droplets impact the substrate.

  17. Interaction of a polydisperse spray with vortices

    NASA Astrophysics Data System (ADS)

    Lacour, C.; Durox, D.; Ducruix, S.; Massot, M.

    2011-08-01

    The objective of the present work is to provide, through the association of optical diagnostics on a well-chosen experimental configuration, new insights into the coupling of a vortical gaseous flow with a polydisperse evaporating spray representative of practical injections. A cloud of droplets is injected in an inert laminar round jet, axisymmetric and pulsated, enabling the study of the interaction of strong-vorticity structures with a polydisperse spray. The experiment is a laboratory-scale representation of realistic injection configurations such as in engine combustion chambers or industrial burners. The chosen set-up leads to a well-controlled configuration and allows the coupling of two optical diagnostics, particle imaging velocimetry (PIV) and interferometric particle imaging (IPI), which leads to the study of both the flow dynamic and the droplet size distribution. The behaviour of droplets is analysed regarding their relaxing and evaporating properties. Size-conditioned preferential concentration of both weakly evaporating and strongly evaporating sprays is investigated. Droplet trajectories are also analysed by means of high-rate tomographic visualizations. The time history between their ejection from the nozzle and their interaction with the vortex is strongly related to the droplet preferential concentration and the observed heterogeneous repartition in the gas flow.

  18. "Clickers" and Metacognition: A Quasi-Experimental Comparative Study about Metacognitive Self-Regulation and Use of Electronic Feedback Devices

    ERIC Educational Resources Information Center

    Brady, Melanie; Seli, Helena; Rosenthal, Jane

    2013-01-01

    The purpose of this study was to establish whether electronic response systems (clickers) influence student metacognition in large lecture settings more than low-technology polling devices. In this first part of a two part mixed methods study inquiry was made into whether student metacognition was influenced and how metacognition was influenced.…

  19. "Clickers" and Metacognition: A Quasi-Experimental Comparative Study about Metacognitive Self-Regulation and Use of Electronic Feedback Devices

    ERIC Educational Resources Information Center

    Brady, Melanie; Seli, Helena; Rosenthal, Jane

    2013-01-01

    The purpose of this study was to establish whether electronic response systems (clickers) influence student metacognition in large lecture settings more than low-technology polling devices. In this first part of a two part mixed methods study inquiry was made into whether student metacognition was influenced and how metacognition was influenced.…

  20. An experimental study of an airfoil with a bio-inspired leading edge device at high angles of attack

    NASA Astrophysics Data System (ADS)

    Mandadzhiev, Boris A.; Lynch, Michael K.; Chamorro, Leonardo P.; Wissa, Aimy A.

    2017-09-01

    Robust and predictable aerodynamic performance of unmanned aerial vehicles at the limits of their design envelope is critical for safety and mission adaptability. Deployable aerodynamic surfaces from the wing leading or trailing edges are often used to extend the aerodynamic envelope (e.g. slats and flaps). Birds have also evolved feathers at the leading edge (LE) of their wings, known as the alula, which enables them to perform high angles of attack maneuvers. In this study, a series of wind tunnel experiments are performed to quantify the effect of various deployment parameters of an alula-like LE device on the aerodynamic performance of a cambered airfoil (S1223) at stall and post stall conditions. The alula relative angle of attack, measured from the mean chord of the airfoil, is varied to modulate tip-vortex strength, while the alula deflection angle is varied to modulate the distance between the tip vortex and the wing surface. Integrated lift force measurements were collected at various alula-inspired device configurations. The effect of the alula-inspired device on the boundary layer velocity profile and turbulence intensity were investigated through hot-wire anemometer measurements. Results show that as alula deflection angle increases, the lift coefficient also increase especially at lower alula relative angles of attack. Moreover, at post stall wing angles of attack, the wake velocity deficit is reduced in the presence of alula device, confirming the mitigation of the wing adverse pressure gradient. The results are in strong agreement with measurements taken on bird wings showing delayed flow reversal and extended range of operational angles of attack. An engineered alula-inspired device has the potential to improve mission adaptability in small unmanned air vehicles during low Reynolds number flight.

  1. Mesh shrinkage depends on mesh properties and anchoring device: an experimental long-term study in sheep.

    PubMed

    Harsløf, S; Zinther, N; Harsløf, T; Danielsen, C; Wara, P; Friis-Andersen, H

    2017-02-01

    The choice of mesh and anchoring device in laparoscopic ventral hernia repair is controversial. Clinically important long-term properties of mesh and anchoring device such as mesh shrinkage have been sparsely investigated. Furthermore, the effect of various anchoring devices on mesh properties has never been examined. In 20 sheep, using laparoscopy, we inserted three PhysiomeshTM (large pore, lightweight) and three VentralightTMST (small pore, mediumweight), anchored with ProTackTM, SecurestrapTM or GlubranTM, respectively. After 6 and 12 months, 10 sheep at each time-point, we euthanized the animals, harvested the meshes with fascia, and measured the exact size and area of the mesh, expressing mesh shrinkage as a percentage of the initial area. The shrinkage of PhysiomeshTM was 35.7 %, 23.8 % and 17.7 % when anchored with ProtackTM, GlubranTM or SecurestrapTM, respectively. Shrinkage with ProtackTM was significantly higher than with either GlubranTM or SecurestrapTM, respectively (p<0.01 and p<0.01). The shrinkage of VentralightTMST was 19.3 %, 22.2 % and 19.6 % when anchored with ProtackTM, GlubranTM and SecurestrapTM, respectively (p>0.05 for all pairwise comparisons). Overall shrinkage of PhysiomeshTM anchored with ProtackTM was significantly higher for all comparisons (p<0.01). Our results suggest that mesh shrinkage in sheep takes place within 6 months after implantation. A significant interaction between mesh and type of anchoring indicates that shrinkage may depend on both mesh properties and anchoring device. The results of the current study imply that the combined effect of mesh and anchoring device should be evaluated in future studies.

  2. Advanced Diagnostics for High Pressure Spray Combustion.

    SciTech Connect

    Skeen, Scott A.; Manin, Julien Luc; Pickett, Lyle M.

    2014-06-01

    The development of accurate predictive engine simulations requires experimental data to both inform and validate the models, but very limited information is presently available about the chemical structure of high pressure spray flames under engine- relevant conditions. Probing such flames for chemical information using non- intrusive optical methods or intrusive sampling techniques, however, is challenging because of the physical and optical harshness of the environment. This work details two new diagnostics that have been developed and deployed to obtain quantitative species concentrations and soot volume fractions from a high-pressure combusting spray. A high-speed, high-pressure sampling system was developed to extract gaseous species (including soot precursor species) from within the flame for offline analysis by time-of-flight mass spectrometry. A high-speed multi-wavelength optical extinction diagnostic was also developed to quantify transient and quasi-steady soot processes. High-pressure sampling and offline characterization of gas-phase species formed following the pre-burn event was accomplished as well as characterization of gas-phase species present in the lift-off region of a high-pressure n-dodecane spray flame. For the initial samples discussed in this work several species were identified, including polycyclic aromatic hydrocarbons (PAH); however, quantitative mole fractions were not determined. Nevertheless, the diagnostic developed here does have this capability. Quantitative, time-resolved measurements of soot extinction were also accomplished and the novel use of multiple incident wavelengths proved valuable toward characterizing changes in soot optical properties within different regions of the spray flame.

  3. INEL Spray-forming Research

    NASA Technical Reports Server (NTRS)

    Mchugh, Kevin M.; Key, James F.

    1993-01-01

    Spray forming is a near-net-shape fabrication technology in which a spray of finely atomized liquid droplets is deposited onto a suitably shaped substrate or mold to produce a coherent solid. The technology offers unique opportunities for simplifying materials processing without sacrificing, and oftentimes substantially improving, product quality. Spray forming can be performed with a wide range of metals and nonmetals, and offers property improvements resulting from rapid solidification (e.g., refined microstructures, extended solid solubilities and reduced segregation). Economic benefits result from process simplification and the elimination of unit operations. Researchers at the Idaho National Engineering Laboratory (INEL) are developing spray-forming technology for producing near-net-shape solids and coatings of a variety of metals, polymers, and composite materials. Results from several spray forming programs are presented to illustrate the range of capabilities of the technique as well as the accompanying technical and economic benefits. Low-carbon steel strip greater than 0.75 mm thick and polymer membranes for gas/gas and liquid/liquid separations that were spray formed are discussed; recent advances in spray forming molds, dies, and other tooling using low-melting-point metals are described.

  4. INEL spray-forming research

    SciTech Connect

    McHugh, K.M.; Key, J.F.

    1992-01-01

    Spray forming is a near-net-shape fabrication technology in which a spray of finely atomized liquid droplets is deposited onto a suitably shaped substrate or mold to produce a coherent solid. The technology offers unique opportunities for simplifying materials processing without sacrificing, and oftentimes substantially improving, product quality. Spray forming can be performed with a wide range of metals and nonmetals, and offers property improvements resulting from rapid solidification (e.g. refined microstructures, extended solid solubilities and reduced segregation). Economic benefits result from process simplification and the elimination of unit operations. Researchers at the Idaho National Engineering Laboratory (INEL) are developing spray-forming technology for producing near-net-shape solids and coatings of a variety of metals, polymers, and composite materials. Results from several spray-forming programs are presented to illustrate the range of capabilities of the technique as well as the accompanying technical and economic benefits. Low-carbon steel strip >0.75 mm thick and polymer membranes for gas/gas and liquid/liquid separations that were spray formed are discussed; recent advances in spray forming molds, dies, and other tooling using low-melting-point metals are described.

  5. Modeling sulfur dioxide absorption by fine water spray

    SciTech Connect

    Cheng-Hsiung Huang

    2005-07-01

    A novel theoretical model was developed to determine the removal efficiency of sulfur dioxide using fine water spray. The droplet pH, diameter, S(IV) concentration, sulfur dioxide concentration, and liquid-to-gas ratio are found to influence the absorption of sulfur dioxide by the fine water spray. The results demonstrate that the absorption of sulfur dioxide by the fine water spray increases as the droplet diameter falls. The concentration gradient between the interface of the gaseous and liquid phases causes the absorption of sulfur dioxide by the droplets to increase as the initial S(IV) concentration decreases or the sulfur dioxide concentration increases. The results indicate that the performance of the fine water spray in removing sulfur dioxide is generally improved by reducing the droplet diameter or the initial S(IV) concentration, or by increasing the sulfur dioxide concentration, the droplet pH or the liquid-to-gas ratio. The proposed model reveals the parameters that should be controlled in using a fine water spray device and a method for improving its performance in removing sulfur dioxide.

  6. A New Experimental Device for Transapical Access of the Aortic and Mitral Valves as well as the Aorta in its Various Segments.

    PubMed

    Paim, Leonardo; Fonseca, José Honório Palma da; Arruda, Francismar Vidal de; Gutierrez, Paulo Sampaio; Moreira, Luiz Felipe Pinho; Jatene, Fabio Biscegli

    2017-01-01

    To present the results of a new experimental device developed to facilitate the transapical access in endovascular treatment of structural heart diseases. It aims to reduce the risk of bleeding and complications in this type of access and demonstrate the device as a safe, fast and effective alternative. CorPoint is composed of three parts: introducer, base with coiled spring, and closing capsule. By rotating movements, the spring is introduced into the myocardium and progressively approaches the base to the surface of the heart. Guidewires and catheters are inserted through the hollow central part and, at the end of the procedure, the capsule is screwed over the base, therefore stopping any bleeding. The device was implanted in 15 pigs, weighing 60 kg each, through an anterolateral thoracotomy, while catheters were introduced and guided by fluoroscopy. All animals had minimal bleeding; introducers with diameter up to 22 Fr were used and various catheters and guidewires were easily handled. After finishing the procedure, the closing capsule was attached and no bleeding was observed at the site. This new device has proved effective, fast and secure for the transapical access. This shows great potential for use, especially by ensuring an easier and direct access to the mitral and aortic valves; the shortest distance to be traveled by catheters; access to the ascending and descending aorta; decreased bleeding complications; decreased surgical time; and the possibility of allowing the technique to evolve and become totally percutaneous.

  7. A fluorescent tracer method for evaluating spray transport and fate of field and laboratory spray applications

    USDA-ARS?s Scientific Manuscript database

    Field and laboratory testing spray nozzles and application systems use spray collectors to assess where the spray deposits once it leaves the spray system. Tracer materials, such as oil and water soluble fluorescent dyes, can be mixed into spray solutions in small amounts with minimal impact on the...

  8. Investigation of particulate formation during diesel spray combustion: CARS for diesel spray combustion. Final technical report

    SciTech Connect

    Boedeker, L.R.

    1991-09-01

    An experimental and analytical research program has been carried out whose objectives were to investigate strategies for using coherent anti-Stokes Raman spectroscopy (CARS) laser diagnostic techniques for detecting the vapor phase of liquid fuel sprays, determining fuel-air ratio and the degree of fuel pyrolysis. The extent to which CARS can provide valid vapor phase fuel measurements in the presence of droplets within the CARS resolution volume will determine its ultimate utility for engine measurements. Hence, the priority in this program was maintained toward investigating possible adverse droplet effects on CARS measurements. Droplets in a relevant size range (25-- 50 microns) were generated for convenience with a spray nozzle. Tests were conducted in a spray chamber at 1 atm pressure under near- saturated fuel vapor pressure conditions, with and without a toluene fuel spray turned on. For reasons of safety an inert gas, CO{sub 2}, was used to simulate O{sub 2}. It was necessary to provide reliable vapor phase CARS reference spectra for these spray studies in order to insure that spurious liquid effects were not present and known vapor phase spectra were attained. To provide these reference spectra the capability was developed of isolating, in a CARS test cell, the vapor phase of fuels that are normally liquids at room temperature and pressure. The cell could be evacuated with a vacuum pump and heated uniformly up to about 100 C. Hence, a capability was established to measure nonresonant and resonant vapor phase CARS features of normally liquid fuels over wide pressure and temperature range, needed for evaluating CARS fuel-air analysis strategies.

  9. Spray characterization and turbulence properties in an isothermal spray with swirl

    SciTech Connect

    de la Rosa, A.B.; Bachalo, W.D.; Rudoff, R.C. )

    1990-01-01

    The present work reports an experimental study of the effect of swirl on the dynamic behavior of drops and on the velocity and turbulence fields of an isothermal spray using a two-component phase Doppler particle analyzer (PDPA). It represents the first phase of an effort to investigate the effect of swirl on the structure of liquid spray flames, the stability of the flame, and its effect on the emission of pollutants. A vane-type swirler was placed on the liquid supply tube of a pressure atomizer and tested in the wind tunnel under specified conditions. Mean velocity and turbulence properties were obtained for the gas phase. In addition, drop velocity and drop size distributions, particle number densities, and volume flux were measured at different locations within the swirling flow. Large differences in the spatial distribution of the drops over its size, velocity, and number density are observed when the spray in coflowing air with the same axial velocity is compared with the atomizer spraying into the swirling flow field. Large drops seem to be recirculated into the core of the swirling flow, while rather small drops surround this central region. The radial distribution of particle number density and the liquid volume flux are also different when the atomizer spraying into the coflowing air and into the swirling field are compared. Particle number densities for the latter exhibit higher peak values close to the nozzle; but show almost the same peak values as in the coflowing case but at a different radial location further downstream. The velocity of specific drop sizes was also obtained.

  10. Cold Spray Technology for DOD Applications

    DTIC Science & Technology

    2012-08-01

    Distribution Unlimited Mechanical Mixing at Interface • .. Sm-in ,, aluminum Approved for Public Release; Distribution Unlimited Cold Spray vs...of Corrosion Damage on Fielded Parts and Subsequent to Cold Spray Repair Before After 15 Cold Spray HP- Aluminum Fill...Unlimited Development and Implementation of Commercially Pure (CP) Aluminum and 6061 Aluminum Alloy Cold Spray Coatings for the Repair of Magnesium

  11. Experimental evaluation of personal protection devices against graphite nanoaerosols: fibrous filter media, masks, protective clothing, and gloves.

    PubMed

    Golanski, L; Guiot, A; Rouillon, F; Pocachard, J; Tardif, F

    2009-06-01

    In this study, different conventional personal protection devices (fibrous filters, cartridges for respirators, protective clothing, and gloves) well qualified for micron particles were tested with graphite nanoparticles ranging from 10 to 100 nm (electrical mobility diameter). For this purpose, two specific test benches were designed: one for filter-based devices which are tested under a controlled air flow and other for gloves and protective clothing based on the "through diffusion method." The penetration versus particle size shows for most tested filter media the behavior predicted by the theoretical Brownian capture: penetration decreases when particle diameter decreases. No thermal rebound was detected until 10 nm for graphite nanoparticles. Protective clothes were tested by two methods and same trends were obtained. Nonwoven fabrics (air-tight materials) are much more efficient against nanoparticles than cotton and paper. Gloves tested by "through diffusion technique," in static condition seem to efficiently protect against graphite nanoparticles in spite of their important porosity.

  12. Developing a reproducible non-line-of-sight experimental setup for testing wireless medical device coexistence utilizing ZigBee.

    PubMed

    LaSorte, Nickolas J; Rajab, Samer A; Refai, Hazem H

    2012-11-01

    The integration of heterogeneous wireless technologies is believed to aid revolutionary healthcare delivery in hospitals and residential care. Wireless medical device coexistence is a growing concern given the ubiquity of wireless technology. In spite of this, a consensus standard that addresses risks associated with wireless heterogeneous networks has not been adopted. This paper serves as a starting point by recommending a practice for assessing the coexistence of a wireless medical device in a non-line-of-sight environment utilizing 802.15.4 in a practical, versatile, and reproducible test setup. This paper provides an extensive survey of other coexistence studies concerning 802.15.4 and 802.11 and reports on the authors' coexistence testing inside and outside an anechoic chamber. Results are compared against a non-line-of-sight test setup. Findings relative to co-channel and adjacent channel interference were consistent with results reported in the literature.

  13. A statistical approach to optimize the spray drying of starch particles: application to dry powder coating.

    PubMed

    Bilancetti, Luca; Poncelet, Denis; Loisel, Catherine; Mazzitelli, Stefania; Nastruzzi, Claudio

    2010-09-01

    This article describes the preparation of starch particles, by spray drying, for possible application to a dry powder coating process. Dry powder coating consists of spraying a fine powder and a plasticizer on particles. The efficiency of the coating is linked to the powder morphological and dimensional characteristics. Different experimental parameters of the spray-drying process were analyzed, including type of solvent, starch concentration, rate of polymer feeding, pressure of the atomizing air, drying air flow, and temperature of drying air. An optimization and screening of the experimental parameters by a design of the experiment (DOE) approach have been done. Finally, the produced spray-dried starch particles were conveniently tested in a dry coating process, in comparison to the commercial initial starch. The obtained results, in terms of coating efficiency, demonstrated that the spray-dried particles led to a sharp increase of coating efficiency value.

  14. Experimental method of in-vivo dosimetry without build-up device on the skin for external beam radiotherapy

    NASA Astrophysics Data System (ADS)

    Jeon, Hosang; Nam, Jiho; Lee, Jayoung; Park, Dahl; Baek, Cheol-Ha; Kim, Wontaek; Ki, Yongkan; Kim, Dongwon

    2015-06-01

    Accurate dose delivery is crucial to the success of modern radiotherapy. To evaluate the dose actually delivered to patients, in-vivo dosimetry (IVD) is generally performed during radiotherapy to measure the entrance doses. In IVD, a build-up device should be placed on top of an in-vivo dosimeter to satisfy the electron equilibrium condition. However, a build-up device made of tissue-equivalent material or metal may perturb dose delivery to a patient, and requires an additional laborious and time-consuming process. We developed a novel IVD method using a look-up table of conversion ratios instead of a build-up device. We validated this method through a monte-carlo simulation and 31 clinical trials. The mean error of clinical IVD is 3.17% (standard deviation: 2.58%), which is comparable to that of conventional IVD methods. Moreover, the required time was greatly reduced so that the efficiency of IVD could be improved for both patients and therapists.

  15. Gas Dynamic Spray Technology Demonstration

    NASA Technical Reports Server (NTRS)

    Burford, Pattie Lewis

    2011-01-01

    Zinc primer systems are currently used across NASA and AFSPC for corrosion protection of steel. AFSPC and NASA have approved the use of Thermal Spray Coatings (TSCs) as an environmentally preferable alternative. TSCs are approved in NASA-STD-5008 and AFSPC and KSC is currently looking for additional applications in which TSC can be used. Gas Dynamic Spray (GDS, also known as Cold Spray) is being evaluated as a means of repairing TSCs and for areas such as corners and edges where TSCs do not work as well. Other applications could include spot repair/maintenance of steel on structures, facilities, and ground support equipment.

  16. DETECTORS AND EXPERIMENTAL METHODS: A comparison of ionizing radiation damage in CMOS devices from 60Co gamma rays, electrons and protons

    NASA Astrophysics Data System (ADS)

    He, Bao-Ping; Yao, Zhi-Bin; Zhang, Feng-Qi

    2009-06-01

    Radiation hardened CC4007RH and non-radiation hardened CC4011 devices were irradiated using 60Co gamma rays, 1 MeV electrons and 1-9 MeV protons to compare the ionizing radiation damage of the gamma rays with the charged particles. For all devices examined, with experimental uncertainty, the radiation induced threshold voltage shifts (ΔVth) generated by 60Co gamma rays are equal to that of 1 MeV electron and 1-7 MeV proton radiation under 0 gate bias condition. Under 5 V gate bias condition, the distinction of threshold voltage shifts (ΔVth) generated by 60Co gamma rays and 1 MeV electrons irradiation are not large, and the radiation damage for protons below 9 MeV is always less than that of 60Co gamma rays. The lower energy the proton has, the less serious the radiation damage becomes.

  17. An experimental wind-tunnel investigation of a ram-air-spoiler roll-control device on a forward-control missile at supersonic speeds

    NASA Technical Reports Server (NTRS)

    Blair, A. B., Jr.

    1978-01-01

    A parametric experimental wind-tunnel investigation was made at supersonic Mach numbers to provide design data on a ram-air-spoiler roll-control device that is to be used on forward-control cruciform missile configurations. The results indicate that the ram-air-spoiler tail fin is an effective roll-control device and that roll control is generally constant with vehicle attitude and Mach number unless direct canard and/or forebody shock impingement occurs. The addition of the ram-air-spoiler tail fins resulted in only small changes in aerodynamic-center location. For the ram-air-spoiler configuration tested, there are large axial force coefficient effects associated with the increased fin thickness and ram-air momentum loss.

  18. Structure of High-Speed Sprays.

    DTIC Science & Technology

    1985-02-01

    Nozzle Spray Holes." Proc. Instn. Mech. Engrs., Vol. 173, 1959, p. 655. 38. Castleman , R.A. "Mechanism of Atomization Accompanying Solid Injection...34 N.A.C.A. Report, 440, 1932. 39. Castleman , R.A. "Mechanism of Atomization of Liquids." U.S. Natl. Bureau Std. J. Res., Vol. 6, 1931, p. 281. 40. Rupe...experimental information. Castleman (21) was among the early supporters of this view. Ranz (22) produced a theoretical ,A framework for it, extending

  19. Exposure of spray-men to dieldrin in residual spraying.

    PubMed

    FLETCHER, T E; PRESS, J M; WILSON, D B

    1959-01-01

    A study of the exposure of spray-men to dieldrin was made in a pilot scheme of residual spraying in the Taveta-Pare area of East Africa. A detailed work study was completed on the operators, and sources of contamination were enumerated. Filter paper pads were placed on the skin and outside clothing and the pick-up was estimated chemically. A spray-man, while using the daily average of 2.12 kg (4.7 pounds) of dieldrin and observing the protective measures laid down, received a dermal exposure of 1.8 mg of dieldrin per kg of body-weight per day. This was possibly reduced somewhat by washing with soap and water upon completion of each day's work. The sixteen spray-men and assistants were exposed for 180 days per year and there was an interim period of 2 months between spray cycles. No clinical symptoms of poisoning were observed.Comparison is made with certain programmes where dieldrin poisoning has occurred. Attention is drawn to the reduced time of exposure in the Taveta-Pare scheme, personal washing, the great value of protective clothing and of its daily washing in soap and water and the need to use a dilute suspension of wettable powder for spraying.

  20. Modifications Of A Commercial Spray Gun

    NASA Technical Reports Server (NTRS)

    Allen, Peter B.

    1993-01-01

    Commercial spray gun modified to increase spray rate and make sprayed coats more nearly uniform. Consists of gun head and pneumatic actuator. Actuator opens valves for two chemical components, called "A" and "B," that react to produce foam. Components flow through orifices, into mixing chamber in head. Mixture then flows through control orifice to spray tip. New spray tip tapered to reduce area available for accumulation of foam and makes tip easier to clean.

  1. Modifications Of A Commercial Spray Gun

    NASA Technical Reports Server (NTRS)

    Allen, Peter B.

    1993-01-01

    Commercial spray gun modified to increase spray rate and make sprayed coats more nearly uniform. Consists of gun head and pneumatic actuator. Actuator opens valves for two chemical components, called "A" and "B," that react to produce foam. Components flow through orifices, into mixing chamber in head. Mixture then flows through control orifice to spray tip. New spray tip tapered to reduce area available for accumulation of foam and makes tip easier to clean.

  2. Tensile adhesion test measurements on plasma-sprayed coatings

    NASA Technical Reports Server (NTRS)

    Berndt, C. C.

    1986-01-01

    Adhesion measurements on plasma-sprayed coatings are briefly studied, including a critical analysis of the experimental scatter for duplicate tests. The application of a simple method which presents adhesion strength data in a fracture mechanics perspective is demonstrated. Available data are analyzed in a way which suggests an approach to finding the overall defect contribution to reducing the apparent strength of coatings.

  3. Simulation of surface roughness during the formation of thermal spray coatings

    SciTech Connect

    Kanouff, M.P.

    1996-07-01

    The formation of a thermal spray coating was analyzed to identify methods to reduce the surface roughness of the coating. A new methodology was developed which uses a string of equally spaced node points to define the shape of the coating surface and to track the shape change as the thermal spray mass is deposited. This allows the calculation of arbitrary shapes for the coating surface which may be very complex. The model simulates the stochastic deposition of a large number of thermal spray droplets, where experimental data is used for the mass flux distribution on the target surface. This data shows that when the thermal spray mass impinges on the target surface, a large fraction of it (over-spray) splashes off the target and is re-deposited with a small spray angle, resulting in a large coating roughness. This analysis was used in a parameter study to identify methods for reducing the coating roughness. Effect of the shape of the profile for the pre-roughened substrate was found to be small. Decreasing the droplet size by a factor of 2 decreased the roughness by 13%. Increasing the spray angle for the over-spray by a factor of 2 decreased the roughness by 50%, and decreasing the amount of over- spray by a factor of 2 decreased the roughness by 51%.

  4. Modeling spray/puddle dissolution processes for deep-ultraviolet acid-hardened resists

    NASA Astrophysics Data System (ADS)

    Hutchinson, John M.; Das, Siddhartha; Qian, Qi-De; Gaw, Henry T.

    1993-10-01

    A study of the dissolution behavior of acid-hardened resists (AHR) was undertaken for spray and spray/puddle development processes. The Site Services DSM-100 end-point detection system is used to measure both spray and puddle dissolution data for a commercially available deep-ultraviolet AHR resist, Shipley SNR-248. The DSM allows in situ measurement of dissolution rate on the wafer chuck and hence allows parameter extraction for modeling spray and puddle processes. The dissolution data for spray and puddle processes was collected across a range of exposure dose and postexposure bake temperature. The development recipe was varied to decouple the contribution of the spray and puddle modes to the overall dissolution characteristics. The mechanisms involved in spray versus puddle dissolution and the impact of spray versus puddle dissolution on process performance metrics has been investigated. We used the effective-dose-modeling approach and the measurement capability of the DSM-100 and developed a lumped parameter model for acid-hardened resists that incorporates the effects of exposure, postexposure bake temperature and time, and development condition. The PARMEX photoresist-modeling program is used to determine parameters for the spray and for the puddle process. The lumped parameter AHR model developed showed good agreement with experimental data.

  5. Field experiment on spray drift: deposition and airborne drift during application to a winter wheat crop.

    PubMed

    Wolters, André; Linnemann, Volker; van de Zande, Jan C; Vereecken, Harry

    2008-11-01

    A field experiment was performed to evaluate various techniques for measuring spray deposition and airborne drift during spray application to a winter wheat crop. The application of a spraying agent containing the fluorescent dye Brilliant Sulfo Flavine by a conventional boom sprayer was done according to good agricultural practice. Deposition was measured by horizontal collectors in various arrangements in and outside the treated area. Airborne spray drift was measured both with a passive and an active air collecting system. Spray deposits on top of the treated canopy ranged between 68 and 71% of the applied dose and showed only small differences for various arrangements of the collectors. Furthermore, only small variations were measured within the various groups of collectors used for these arrangements. Generally, the highest spray deposition outside the treated area was measured close to the sprayed plot and was accompanied by a high variability of values, while a rapid decline of deposits was detected in more remote areas. Estimations of spray deposits with the IMAG Drift Calculator were in accordance with experimental findings only for areas located at a distance of 0.5-4.5 m from the last nozzle, while there was an overestimation of a factor of 4 at a distance of 2.0-3.0 m, thus revealing a high level of uncertainty of the estimation of deposition for short distances. Airborne spray drift measured by passive and active air collecting systems was approximately at the same level, when taking into consideration the collector efficiency of the woven nylon wire used as sampling material for the passive collecting system. The maximum value of total airborne spray drift for both spray applications (0.79% of the applied dose) was determined by the active collecting system. However, the comparatively high variability of measurements at various heights above the soil by active and passive collecting systems revealed need for further studies to elucidate the spatial

  6. Process Sprays Uniforms Plasma Coatings

    NASA Technical Reports Server (NTRS)

    Sliney, H. E.; Jacobson, T. P.; Walther, G. C.; Nakamura, H. H.

    1983-01-01

    Composite-powder processing procedure developed along with plasma-spray parameters to achieve homogeneous, well-bonded, low-porosity, self-lubricating coatings. Multicomponent plasma coatings are applied without segretation of components.

  7. Spray nozzle for fire control

    NASA Astrophysics Data System (ADS)

    Papavergos, Panayiotis G.

    1990-09-01

    The design of a spray nozzle for fire control is described. It produces a spray of gas and liquid having an oval transverse cross section and it comprises a mixing chamber with an oval transverse cross section adapted to induce a toroidal mixing pattern in pressurized gas and liquid introduced to the mixing chamber through a plurality of inlets. In a preferred embodiment the mixing chamber is toroidal. The spray nozzle produces an oval spray pattern for more efficient wetting of narrow passages and is suitable for fire control systems in vehicles or other confined spaces. Vehicles to which this invention may be applied include trains, armoured vehicles, ships, hovercraft, submarines, oil rigs, and most preferably, aircraft.

  8. Estimation of the diameter-charge distribution in polydisperse electrically charged sprays of electrically insulating liquids

    NASA Astrophysics Data System (ADS)

    Rigit, A. R. H.; Shrimpton, John S.

    2009-06-01

    The majority of scientific and industrial electrical spray applications make use of sprays that contain a range of drop diameters. Indirect evidence suggests the mean drop diameter and the mean drop charge level are usually correlated. In addition, within each drop diameter class there is every reason to suspect a distribution of charge levels exist for a particular drop diameter class. This paper presents an experimental method that uses the joint PDF of drop velocity and diameter, obtained from phase Doppler anemometry measurements, and directly obtained spatially resolved distributions of the mass and charge flux to obtain a drop diameter and charge frequency distribution. The method is demonstrated using several data-sets obtained from experimental measurements of steady poly-disperse sprays of an electrically insulating liquid produced with the charge injection technique. The space charge repulsion in the spray plume produces a hollow cone spray structure. In addition an approximate self-similarity is observed, with the maximum radial mass and charge flow occurring at r/ d ~ 200. The charge flux profile is slightly offset from the mass flux profile, and this gives direct evidence that the spray specific charge increases from approximately 20% of the bulk mean spray specific charge on the spray axis to approximately 200% of the bulk mean specific charge in the periphery of the spray. The results from the drop charge estimation model suggest a complex picture of the correlation between drop charge and drop diameter, with spray specific charge, injection velocity and orifice diameter all contributing to the shape of the drop diameter-charge distribution. Mean drop charge as a function of the Rayleigh limit is approximately 0.2, and is invariant with drop diameter and also across the spray cases tested.

  9. A novel gas-droplet numerical method for spray combustion

    NASA Technical Reports Server (NTRS)

    Chen, C. P.; Shang, H. M.; Jiang, Y.

    1991-01-01

    This paper presents a non-iterative numerical technique for computing time-dependent gas-droplet flows. The method is a fully-interacting combination of Eulerian fluid and Lagrangian particle calculation. The interaction calculations between the two phases are formulated on a pressure-velocity coupling procedure based on the operator-splitting technique. This procedure eliminates the global iterations required in the conventional particle-source-in-cell (PSIC) procedure. Turbulent dispersion calculations are treated by a stochastic procedure. Numerical calculations and comparisons with available experimental data, as well as efficiency assessments are given for some sprays typical of spray combustion applications.

  10. Characteristics of Vaporizing Cryogenic Sprays for Rocket Combustion Modeling

    NASA Technical Reports Server (NTRS)

    Ingebo, Robert D.

    1994-01-01

    Experimental measurements of the volume-median drop diameter, Dv.5e, of vaporizing cryogenic sprays were obtained with a drop size measuring instrument developed at NASA Lewis Research Center. To demonstrate the effect of atomizing-gas properties on characteristic drop size, a two-fluid fuel nozzle was used to break up liquid-nitrogen, LN2, jets in high-velocity gasflows of helium argon and gaseous nitrogen, GN2. Also, in order to determine the effect of atomizing-gas temperature on specific surface-areas of LN2 sprays, drop size measurements were made at gas temperatures of 111 and 293 K.

  11. Research on electrostatic electrification during jet kerosene spraying

    NASA Astrophysics Data System (ADS)

    Liu, Quanzhen; Zhang, Wentian; Li, Yipeng; Sun, Keping

    2013-03-01

    Multiple electrostatic electrifications during aircraft fuelling process may cause a fire disaster or explosion, so study on the protection measure for electrostatic electrification is very important for the security of aircraft fuelling. This paper investigated the electrostatic voltage and charge of the fuel nozzle and metal parts during the fuel spraying by self-designed jet kerosene spraying electrostatic electrification test system. The experimental results indicate that the voltage on the fuel nozzle and metal parts is very dangerous for electrostatic safety if they are not reliably grounded.

  12. Experimental Evaluation and Comparison of Thermal Conductivity of High-Voltage Insulation Materials for Vacuum Electronic Devices

    NASA Astrophysics Data System (ADS)

    Suresh, C.; Srikrishna, P.

    2017-03-01

    Vacuum electronic devices operate with very high voltage differences between their sub-assemblies which are separated by very small distances. These devices also emit large amounts of heat that needs to be dissipated. Hence, there exists a requirement for high-voltage insulators with good thermal conductivity for voltage isolation and efficient heat dissipation. However, these voltage insulators are generally poor conductors of heat. In the present work, an effort has been made to obtain good high-voltage insulation materials with substantial improvement in their thermal conductivity. New mixtures of composites were formed by blending varying percentages (by volumes) of aluminum nitride powders with that of neat room-temperature vulcanizing (RTV) silicone elastomer compound. In this work, a thermal conductivity test setup has been devised for the quantification of the thermal conductivity of the insulators. The thermal conductivities and high-voltage isolation capabilities of various blended composites were quantified and were compared with that of neat RTV to evaluate the relative improvement.

  13. Experimental Evaluation and Comparison of Thermal Conductivity of High-Voltage Insulation Materials for Vacuum Electronic Devices

    NASA Astrophysics Data System (ADS)

    Suresh, C.; Srikrishna, P.

    2017-07-01

    Vacuum electronic devices operate with very high voltage differences between their sub-assemblies which are separated by very small distances. These devices also emit large amounts of heat that needs to be dissipated. Hence, there exists a requirement for high-voltage insulators with good thermal conductivity for voltage isolation and efficient heat dissipation. However, these voltage insulators are generally poor conductors of heat. In the present work, an effort has been made to obtain good high-voltage insulation materials with substantial improvement in their thermal conductivity. New mixtures of composites were formed by blending varying percentages (by volumes) of aluminum nitride powders with that of neat room-temperature vulcanizing (RTV) silicone elastomer compound. In this work, a thermal conductivity test setup has been devised for the quantification of the thermal conductivity of the insulators. The thermal conductivities and high-voltage isolation capabilities of various blended composites were quantified and were compared with that of neat RTV to evaluate the relative improvement.

  14. Experiments on spray from a rolling tire

    NASA Astrophysics Data System (ADS)

    Radovich, Charles Anthony

    A novel laboratory apparatus has been built to understand the key mechanisms behind spray emerging from a rolling tire. Several researchers have assessed the performance of spray suppression devices; however, there are no known efforts that address the question "what needs to be suppressed?" This investigation into how water in a tire groove evolves into a droplet field will ultimately contribute to driver safety. Using high-speed imaging, water passing through a single circumferential groove was observed to leave the tire patch in the form of a thin liquid sheet, connecting the roadway and the tire. The sheet disintegrates into a droplet field and the breakup modes associated with this decay were identified with respect to Weber number. Weber numbers based on the properties of water, tire speed and tire groove width were tested at 2700, 10900 and 24400. Measurements for the breakup length of the liquid sheet showed a dependence on Weber number proportional to We-1/6. The lateral displacement of the water exiting the tire patch was also measured. These tests showed the overall size of the spray field grows with We; however, the maximum water volume for all We's was delivered to the same distance from the road. Downstream from the tire patch, a determination of the droplet field was performed. From this study, the distribution of droplet sizes was determined as a function of Weber number. At We = 2,700, droplet sizes between 80 and 9000 microm were detected, with a mean diameter near 800 microm. Both the range of droplet sizes and the mean diameter were found to decrease with Weber number by approximately We-1/2. Based on these size distributions, Correlation Image Velocimetry (CIV) was used to estimate the distribution of droplet velocities as function of their size. These results reveal a strong correlation between droplet diameter and velocity which is comparable to that predicted for a simple sphere.

  15. Smartphones as Experimental Tools: Different Methods to Determine the Gravitational Acceleration in Classroom Physics by Using Everyday Devices

    ERIC Educational Resources Information Center

    Kuhn, Jochen; Vogt, Patrik

    2013-01-01

    New media technology becomes more and more important for our daily life as well as for teaching physics. Within the scope of our N.E.T. research project we develop experiments using New Media Experimental Tools (N.E.T.) in physics education and study their influence on students learning abilities. We want to present the possibilities e.g. of…

  16. Comparison of different hard, metal-like coatings sprayed by plasma and detonation gun processes

    SciTech Connect

    Vuoristo, P.; Niemi, K.; Maentylae, T.; Berger, L.M.; Nebelung, M.

    1995-12-31

    Structure and wear properties of atmospheric plasma sprayed and detonation gun sprayed coatings prepared from an experimental (Ti,Mo)C-28.4%NiCo powder were compared to coatings sprayed from commercially available WC-12%Co and Cr{sub 3}C{sub 2}-25%NiCr powders. All powders had an agglomerated (spray dried) and sintered structure and nearly the same content of the metallic binder of approximately 20 vol.-%. The powders were characterized by SEM (morphology and cross-sections) and X-ray diffraction (phase composition). The coatings were studied by optical microscope, microhardness measurements, X-ray diffraction analysis and by abrasion and erosion wear tests. The X-ray diffraction patterns of the coatings show that the (Ti,Mo)C-28.4%NiCo powder is characterized by high phase stability in both spray processes, whereas the WC-12%Co powder is prone to significant phase transformations during spraying. The results clearly show the high potential of the experimental (Ti,Mo)C-28.4%NiCo coatings in substituting the conventional systems in wear applications. For instance, it was found that plasma spraying of the (Ti,Mo)C-28.4%NiCo powder with an Ar-H{sub 2} plasma gas resulted in coatings with wear resistance comparable to WC-12%Co coatings. However, detonation gun sprayed WC-12%Co coatings showed somewhat better abrasion wear resistance.

  17. CFD Modeling of Superheated Fuel Sprays

    NASA Technical Reports Server (NTRS)

    Raju, M. S.

    2008-01-01

    An understanding of fuel atomization and vaporization behavior at superheat conditions is identified to be a topic of importance in the design of modern supersonic engines. As a part of the NASA aeronautics initiative, we have undertaken an assessment study to establish baseline accuracy of existing CFD models used in the evaluation of a ashing jet. In a first attempt towards attaining this goal, we have incorporated an existing superheat vaporization model into our spray solution procedure but made some improvements to combine the existing models valid at superheated conditions with the models valid at stable (non-superheat) evaporating conditions. Also, the paper reports some validation results based on the experimental data obtained from the literature for a superheated spray generated by the sudden release of pressurized R134A from a cylindrical nozzle. The predicted profiles for both gas and droplet velocities show a reasonable agreement with the measured data and exhibit a self-similar pattern similar to the correlation reported in the literature. Because of the uncertainty involved in the specification of the initial conditions, we have investigated the effect of initial droplet size distribution on the validation results. The predicted results were found to be sensitive to the initial conditions used for the droplet size specification. However, it was shown that decent droplet size comparisons could be achieved with properly selected initial conditions, For the case considered, it is reasonable to assume that the present vaporization models are capable of providing a reasonable qualitative description for the two-phase jet characteristics generated by a ashing jet. However, there remains some uncertainty with regard to the specification of certain initial spray conditions and there is a need for experimental data on separate gas and liquid temperatures in order to validate the vaporization models based on the Adachi correlation for a liquid involving R134A.

  18. Sea Spray and Icing in the Emerging Open Water of the Arctic Ocean

    DTIC Science & Technology

    2012-09-30

    spray instrument will be a cloud imaging probe, which we are borrowing from Chris Fairall at NOAA/ESRL. This device consists of an optical array; it...each 25 µm wide. The integral of the third moment of the drop concentration from the cloud imaging probe is the spray liquid water content. Hence...Gloersen P, Zwally HJ. 1996. updated yearly. Sea Ice Concentrations from Nimbus -7 SMMR and DMSP SSM/I-SSMIS Passive Microwave Data, October 1979. Boulder

  19. The Effect of Fuel Injector Nozzle Configuration on JP-8 Sprays at Diesel Engine Conditions

    DTIC Science & Technology

    2014-10-01

    CFD study was conducted to compare modeling to experimental results. Fuel spray studies investigating liquid and vapor penetrations lengths can be...injectors tested. In addition, a 3D CFD study was conducted to compare modeling to experimental results. Fuel spray studies investigating liquid and...with six fuels including conventional (No. 2 Diesel, JP-8, Jet -A), alternative fuels, and a surrogate with the objective of assessing the performance

  20. Coupled Monte Carlo Probability Density Function/ SPRAY/CFD Code Developed for Modeling Gas-Turbine Combustor Flows

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The success of any solution methodology for studying gas-turbine combustor flows depends a great deal on how well it can model various complex, rate-controlling processes associated with turbulent transport, mixing, chemical kinetics, evaporation and spreading rates of the spray, convective and radiative heat transfer, and other phenomena. These phenomena often strongly interact with each other at disparate time and length scales. In particular, turbulence plays an important role in determining the rates of mass and heat transfer, chemical reactions, and evaporation in many practical combustion devices. Turbulence manifests its influence in a diffusion flame in several forms depending on how turbulence interacts with various flame scales. These forms range from the so-called wrinkled, or stretched, flamelets regime, to the distributed combustion regime. Conventional turbulence closure models have difficulty in treating highly nonlinear reaction rates. A solution procedure based on the joint composition probability density function (PDF) approach holds the promise of modeling various important combustion phenomena relevant to practical combustion devices such as extinction, blowoff limits, and emissions predictions because it can handle the nonlinear chemical reaction rates without any approximation. In this approach, mean and turbulence gas-phase velocity fields are determined from a standard turbulence model; the joint composition field of species and enthalpy are determined from the solution of a modeled PDF transport equation; and a Lagrangian-based dilute spray model is used for the liquid-phase representation with appropriate consideration of the exchanges of mass, momentum, and energy between the two phases. The PDF transport equation is solved by a Monte Carlo method, and existing state-of-the-art numerical representations are used to solve the mean gasphase velocity and turbulence fields together with the liquid-phase equations. The joint composition PDF