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. PMID:23303644

  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. 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)

  7. 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. PMID:27509293

  8. 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.

  9. 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.

  10. 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.

  11. Experimental studies on effervescent atomizers with wide spray angles

    NASA Technical Reports Server (NTRS)

    Whitlow, J. D.; Lefebvre, A. H.; Rollbuhler, R. J.

    1993-01-01

    An experimental investigation was conducted to examine the operating and spray characteristics of two internal-mixing twin-fluid atomizers that were designed to produce effervescent atomization at low air/liquid mass ratios (ALR's). These two experimental atomizers ejected the two phase flow so as to produce a wide spray angle. One atomizer was a plain orifice design that used a four-hole exit orifice which divided and turned the two phase flow just prior to ejection. The other atomizer, called the conical sheet atomizer, ejected the two phase flow through an annular passage in such a way as to form a hollow cone spray. The atomizer operating parameters varied during this investigation were the air/liquid mass ratio, atomizer operating pressure, and, in the case of the conical sheet atomizer, the exit gap width. Studies of spray characteristics included measurements of the spray Sauter mean diameter (SMD), drop size distribution, and, for the conical sheet atomizer, circumferential distribution of the liquid mass within the spray. For both atomizers it was found that SMD decreases with an increase in either ALR or operating pressure. The effect of ALR on SMD diminishes as the value of ALR increases. For the conical sheet atomizer, when operating at low values of pressure and ALR, SMD increases with increase in gap width, but the influence of gap width on SMD diminishes with an increase in either pressure or ALR. At the highest operating pressure of the conical sheet atomizer (552 kPa), SMD is independent of gap width at all ALR's. For both atomizers, changes in operating pressure and ALR have little effect on the distribution of drop sizes in the spray.

  12. Experimental studies on effervescent atomizers with wide spray angles

    NASA Astrophysics Data System (ADS)

    Whitlow, J. D.; Lefebvre, A. H.; Rollbuhler, R. J.

    1993-09-01

    An experimental investigation was conducted to examine the operating and spray characteristics of two internal-mixing twin-fluid atomizers that were designed to produce effervescent atomization at low air/liquid mass ratios (ALR's). These two experimental atomizers ejected the two phase flow so as to produce a wide spray angle. One atomizer was a plain orifice design that used a four-hole exit orifice which divided and turned the two phase flow just prior to ejection. The other atomizer, called the conical sheet atomizer, ejected the two phase flow through an annular passage in such a way as to form a hollow cone spray. The atomizer operating parameters varied during this investigation were the air/liquid mass ratio, atomizer operating pressure, and, in the case of the conical sheet atomizer, the exit gap width. Studies of spray characteristics included measurements of the spray Sauter mean diameter (SMD), drop size distribution, and, for the conical sheet atomizer, circumferential distribution of the liquid mass within the spray. For both atomizers it was found that SMD decreases with an increase in either ALR or operating pressure. The effect of ALR on SMD diminishes as the value of ALR increases. For the conical sheet atomizer, when operating at low values of pressure and ALR, SMD increases with increase in gap width, but the influence of gap width on SMD diminishes with an increase in either pressure or ALR. At the highest operating pressure of the conical sheet atomizer (552 kPa), SMD is independent of gap width at all ALR's. For both atomizers, changes in operating pressure and ALR have little effect on the distribution of drop sizes in the spray.

  13. Bio-sample detection on paper-based devices with inkjet printer-sprayed reagents.

    PubMed

    Liang, Wun-Hong; Chu, Chien-Hung; Yang, Ruey-Jen

    2015-12-01

    The reagent required for bio-sample detection on paper-based analytical devices is generally introduced manually using a pipette. Such an approach is time-consuming; particularly if a large number of devices are required. Automated methods provide a far more convenient solution for large-scale production, but incur a substantial cost. Accordingly, the present study proposes a low-cost method for the paper-based analytical devices in which the biochemical reagents are sprayed onto the device directly using a modified commercial inkjet printer. The feasibility of the proposed method is demonstrated by performing aspartate aminotransferase (AST) and alanine aminotransferase (ALT) tests using simple two-dimensional (2D) paper-based devices. In both cases, the reaction process is analyzed using an image-processing-based colorimetric method. The experimental results show that for AST detection within the 0-105 U/l concentration range, the optimal observation time is around four minutes, while for ALT detection in the 0-125 U/l concentration range, the optimal observation time is approximately one minute. Finally, for both samples, the detection performance of the sprayed-reagent analytical devices is insensitive to the glucose concentration.

  14. 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.

  15. Experimental testing of spray dryer for control of incineration emissions.

    PubMed

    Wey, M Y; Wu, H Y; Tseng, H H; Chen, J C

    2003-05-01

    The research investigated the absorption/adsorption efficiency of sulfur dioxide (SO2), heavy metals, and polycyclic aromatic hydrocarbons (PAHs) with different Ca-based sorbents in a spray dryer during incineration process. For further improving the adsorption capacity of Ca-based sorbents, different spraying pressure and additives were carried out in this study. Experimental results showed that CaO could be used as an alternative sorbent in the spray dryer at an optimal initial particle size distribution of spraying droplet. In the spray dryer, Ca-based sorbents provided a lot of sites for heavy metals and PAHs condensing and calcium and alkalinity to react with metals to form merged species. As a result, heavy metals and PAHs could be removed from the flue gas simultaneously by condensation and adsorption. The additions of additives NaHCO3, SiO2, and KMnO4 were also found to be effective in improving the removal efficiency of these air pollutants.

  16. 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.

  17. 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. PMID:25852429

  18. Fabrication of Thermoelectric Devices Using Thermal Spray: Application to Vehicle Exhaust Systems

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

    Thermoelectric devices produce electricity directly from heat; they are small, have no moving parts, and are quiet. Commercially available thermoelectric devices, however, are expensive and labor intensive to produce, and come in very limited form factors. This article presents initial results for the use of thermal spray to directly fabricate thermoelectric devices. The target application is automotive exhaust systems and other high-volume heat sources. In this work, FeSi2 and Mg2Si metal silicides were sprayed. Characterization of the Mg2Si deposits indicates that both the thermal conductivity and the Seebeck coefficient are roughly one half the values of bulk Mg2Si. The electrical conductivity, however, is several orders of magnitude lower than bulk measurements in the literature, with likely reasons including impurities in the starting powder, oxidation during spraying, and using an undoped material. Fe x Co4- x Sb12 skutterudite material has also been sprayed; however, not enough powder was available to fabricate samples large enough for characterization. The steps required to fabricate a thermoelectric device are presented, including the formation of the bottom and top metallic layers and the thermoelectric legs using thermal spray and laser micromachining. A technique for bridging the air gap between adjacent thermoelectric elements for the top layer based on a sacrificial filler material has also been demonstrated.

  19. 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.

  20. 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%.

  1. 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.

  2. 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. PMID:25723519

  3. 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

  4. An experimental study of air-assist atomizer spray flames

    NASA Technical Reports Server (NTRS)

    Mao, Chien-Pei; Wang, Geng; Chigier, Norman

    1988-01-01

    It is noted that air-assisted atomizer spray flames encountered in furnaces, boilers, and gas turbine combustors possess a more complex structure than homogeneous turbulent diffusion flames, due to the swirling motion introduced into the fuel and air flows for the control of flame stability, length, combustion intensity, and efficiency. Detailed comparisons are presented between burning and nonburning condition measurements of these flames obtained by nonintrusive light scattering phase/Doppler detection. Spray structure is found to be drastically changed within the flame reaction zone, with changes in the magnitude and shape of drop number density, liquid flux, mean drop size diameter, and drop mean axial velocity radial distributions.

  5. Experimental measurement-device-independent entanglement detection.

    PubMed

    Nawareg, Mohamed; Muhammad, Sadiq; Amselem, Elias; Bourennane, Mohamed

    2015-01-01

    Entanglement is one of the most puzzling features of quantum theory and of great importance for the new field of quantum information. The determination whether a given state is entangled or not is one of the most challenging open problems of the field. Here we report on the experimental demonstration of measurement-device-independent (MDI) entanglement detection using witness method for general two qubits photon polarization systems. In the MDI settings, there is no requirement to assume perfect implementations or neither to trust the measurement devices. This experimental demonstration can be generalized for the investigation of properties of quantum systems and for the realization of cryptography and communication protocols. PMID:25649664

  6. BWR refill-reflood program: core spray distribution experimental task plan

    SciTech Connect

    Eckert, T.

    1981-02-01

    An experimental task plan for the BWR/4 core spray task of the Refill-Reflood Test Program is presented. The test program will provide core spray distribution data for a 30 degree sector of the BWR/4 and 5-218 design. This design uses different nozzle types and different sparger elevations than the BWR/6-218 design which was tested previously. Test parameter ranges are specified; individual tests are defined; and measurement and data utilization plans are defined.

  7. 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.

  8. 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

  9. Experimental study of flash boiling spray vaporization through quantitative vapor concentration and liquid temperature measurements

    NASA Astrophysics Data System (ADS)

    Zhang, Gaoming; Hung, David L. S.; Xu, Min

    2014-08-01

    Flash boiling sprays of liquid injection under superheated conditions provide the novel solutions of fast vaporization and better air-fuel mixture formation for internal combustion engines. However, the physical mechanisms of flash boiling spray vaporization are more complicated than the droplet surface vaporization due to the unique bubble generation and boiling process inside a superheated bulk liquid, which are not well understood. In this study, the vaporization of flash boiling sprays was investigated experimentally through the quantitative measurements of vapor concentration and liquid temperature. Specifically, the laser-induced exciplex fluorescence technique was applied to distinguish the liquid and vapor distributions. Quantitative vapor concentration was obtained by correlating the intensity of vapor-phase fluorescence with vapor concentration through systematic corrections and calibrations. The intensities of two wavelengths were captured simultaneously from the liquid-phase fluorescence spectra, and their intensity ratios were correlated with liquid temperature. The results show that both liquid and vapor phase of multi-hole sprays collapse toward the centerline of the spray with different mass distributions under the flash boiling conditions. Large amount of vapor aggregates along the centerline of the spray to form a "gas jet" structure, whereas the liquid distributes more uniformly with large vortexes formed in the vicinity of the spray tip. The vaporization process under the flash boiling condition is greatly enhanced due to the intense bubble generation and burst. The liquid temperature measurements show strong temperature variations inside the flash boiling sprays with hot zones present in the "gas jet" structure and vortex region. In addition, high vapor concentration and closed vortex motion seem to have inhibited the heat and mass transfer in these regions. In summary, the vapor concentration and liquid temperature provide detailed information

  10. 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.

  11. Experimental evolution of sprays in a lung model

    NASA Astrophysics Data System (ADS)

    Burguete, Javier; Aliseda, Alberto

    2015-11-01

    We present the first results of an experiment conceived to observe the evolution of sprays inside the lungs. We have built a model that covers the first 6 generations (from the trachea to segmental bronchi of 5th generation). This setup is placed on a wind tunnel, and the flow inside the model is induced by a vacuum pump that emulates the breathing process using a valve. We inject a previously determined distribution of particles (water droplets), whose average diameter can be modified. Then, we measure the droplet distribution in different branches and compare how the droplet distribution is modified at each generation. The parameters that control the behavior are the average diameter of the original distribution, the airflow rate inside the model and the frequency of the breathing cycle.

  12. 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.

  13. 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.

  14. Evaluation of a Consistent LES/PDF Method Using a Series of Experimental Spray Flames

    NASA Astrophysics Data System (ADS)

    Heye, Colin; Raman, Venkat

    2012-11-01

    A consistent method for the evolution of the joint-scalar probability density function (PDF) transport equation is proposed for application to large eddy simulation (LES) of turbulent reacting flows containing evaporating spray droplets. PDF transport equations provide the benefit of including the chemical source term in closed form, however, additional terms describing LES subfilter mixing must be modeled. The recent availability of detailed experimental measurements provide model validation data for a wide range of evaporation rates and combustion regimes, as is well-known to occur in spray flames. In this work, the experimental data will used to investigate the impact of droplet mass loading and evaporation rates on the subfilter scalar PDF shape in comparison with conventional flamelet models. In addition, existing model term closures in the PDF transport equations are evaluated with a focus on their validity in the presence of regime changes.

  15. 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.

  16. 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).

  17. 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.

  18. Experimental and analytical investigation of the variation of spray characteristics along a radial distance downstream of a pressure-swirl atomizer

    NASA Technical Reports Server (NTRS)

    Chin, J. S.; Li, W. M.; Wang, X. F.

    1986-01-01

    The variation of spray characteristics along a radial distance downstream of a pressure-swirl atomizer was measured by laser light-scattering technology. An analytical model was developed to predict the variation of spray characteristics along the radial distance. A comparison of the predicted and experimental data showed excellent agreement. Therefore, the spray model proposed, although relatively simple, is correct and can be used, with some expansion and modification of the prepared model, to predict more complicated spray systems.

  19. A new stereolithography experimental porous flow device.

    PubMed

    Crandall, Dustin; Ahmadi, Goodarz; Leonard, Douglas; Ferer, Martin; Smith, Duane H

    2008-04-01

    A new method for constructing laboratory-scale porous media with increased pore-level variabilities for two-phase flow experiments is presented here. These devices have been created with stereolithography directly on glass, thus improving the stability of the model created with this precision rapid construction technique. The method of construction and improved parameters are discussed in detail, followed by a brief comparison of two-phase drainage results for air invasion into the water-saturated porous medium. Flow through the model porous medium is shown to substantiate theoretical fractal predictions.

  20. An Experimental Device to Record Infant Head Movements.

    ERIC Educational Resources Information Center

    Jouen, Francois

    1981-01-01

    Analyzes methods used to record infant head position and the limits of these methods. An experimental device is proposed which records infant head turning and head righting when the vestibular system is stimulated. (Author/DB)

  1. The structure and thermal properties of plasma-sprayed beryllium for the International Thermonuclear Experimental Reactor (ITER)

    SciTech Connect

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

    1996-09-01

    Plasma spraying is being studied for in situ repair of damaged Be and W plasma facing surfaces for ITER, the next generation magnetic fusion energy device, and is also being considered for fabricating Be and W plasma-facing components for the first wall of ITER. Investigators at LANL`s Beryllium Atomization and Thermal Spray Facility have concentrated on investigating the structure-property relation between as-deposited microstructures of plasma sprayed Be coatings and resulting thermal properties. In this study, the effect of initial substrate temperature on resulting thermal diffusivity of Be coatings and the thermal diffusivity at the coating/Be substrate interface (interface thermal resistance) was investigated. Results show that initial Be substrate temperatures above 600 C can improve the thermal diffusivity of the Be coatings and minimize any thermal resistance at the interface between the Be coating and Be substrate.

  2. A Taguchi experimental design study of twin-wire electric arc sprayed aluminum coatings

    SciTech Connect

    Steeper, T.J. ); Varacalle, D.J. Jr.; Wilson, G.C.; Johnson, R.W. ); Irons, G.; Kratochvil, W.R. ); Riggs, W.L. II )

    1992-01-01

    An experimental study was conducted on the twin-wire electric arc spraying of aluminum coatings. This aluminum wire system is being used to fabricate heater tubes that emulate nuclear fuel tubes for use in thermal-hydraulic experiments. Experiments were conducted using a Taguchi fractional-factorial design parametric study. Operating parameters were varied around the typical process parameters in a systematic design of experiments in order to display the range of processing conditions and their effect on the resultant coating. The coatings were characterized by hardness tests, optical metallography, and image analysis. The paper discusses coating qualities with respect to hardness, roughness, deposition efficiency, and microstructure. The study attempts to correlate the features of the coatings with the changes in operating parameters. A numerical model of the process is presented including gas, droplet, and coating dynamics.

  3. A Taguchi experimental design study of twin-wire electric arc sprayed aluminum coatings

    SciTech Connect

    Steeper, T.J.; Varacalle, D.J. Jr.; Wilson, G.C.; Johnson, R.W.; Irons, G.; Kratochvil, W.R.; Riggs, W.L. II

    1992-08-01

    An experimental study was conducted on the twin-wire electric arc spraying of aluminum coatings. This aluminum wire system is being used to fabricate heater tubes that emulate nuclear fuel tubes for use in thermal-hydraulic experiments. Experiments were conducted using a Taguchi fractional-factorial design parametric study. Operating parameters were varied around the typical process parameters in a systematic design of experiments in order to display the range of processing conditions and their effect on the resultant coating. The coatings were characterized by hardness tests, optical metallography, and image analysis. The paper discusses coating qualities with respect to hardness, roughness, deposition efficiency, and microstructure. The study attempts to correlate the features of the coatings with the changes in operating parameters. A numerical model of the process is presented including gas, droplet, and coating dynamics.

  4. 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. PMID:22516767

  5. 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.

  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. Parametric appraisal of process parameters for adhesion of plasma sprayed nanostructured YSZ coatings using Taguchi experimental design.

    PubMed

    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.

  8. Al2O3/Al Cermets by Plasma Spraying: Optical Response of Experimental and Numerically Represented Materials

    NASA Astrophysics Data System (ADS)

    Toru, D.; Echegut, R.; Quet, A.; De Sousa Meneses, D.; del Campo, L.; Piombini, H.; Echegut, P.; Bianchi, L.

    2016-01-01

    Optical properties of plasma-sprayed coatings and numerically represented samples were studied at wavelengths ranging from visible to mid-infrared. The paper focuses on Al2O3 and Al2O3/Al cermet coatings with different metal concentrations. Microstructure and composition of the samples were characterized in order to explain their optical response that is highly dependent on volume and/or surface scattering as a function of the wavelength range. 2D scanning electron microscopy and 3D x-ray microtomography images were exploited to get statistical data in order to numerically represent simplified samples from the complex microstructure of plasma-sprayed coatings. A Monte Carlo ray-tracing model, based on geometrical optical laws, was then applied to reproduce experimental trends of the acquired optical spectra. Good agreement with the experimental data was obtained.

  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 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. PMID:11036729

  11. 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%.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

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

    PubMed

    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.

  17. 30 CFR 75.1107-7 - Water spray devices; capacity; water supply; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...; 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 and Fire-Resistant Hydraulic Fluids on Underground Equipment §...

  18. 30 CFR 75.1107-7 - Water spray devices; capacity; water supply; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...; 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 and Fire-Resistant Hydraulic Fluids on Underground Equipment §...

  19. 30 CFR 75.1107-7 - Water spray devices; capacity; water supply; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...; 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 and Fire-Resistant Hydraulic Fluids on Underground Equipment §...

  20. 30 CFR 75.1107-7 - Water spray devices; capacity; water supply; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...; 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 and Fire-Resistant Hydraulic Fluids on Underground Equipment §...

  1. 30 CFR 75.1107-7 - Water spray devices; capacity; water supply; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...; 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 and Fire-Resistant Hydraulic Fluids on Underground Equipment §...

  2. 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.

  3. Ultrasonic spray evaporative air coolers. Final report

    SciTech Connect

    Not Available

    1982-04-01

    Theoretical and experimental studies on the development of an energy-efficient evaporative air cooling device employing ultrasonic spray nozzles is discussed. The following works were performed during the project period: (1) Feasibility study of a breadboard model of the evaporative cooler, (2) design of a prototype cooling unit for laboratory and field studies, and (3) preliminary survey of potential applications.

  4. 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.

  5. 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.

  6. Experimental study of spray cooling performance on micro-porous coated surfaces

    NASA Astrophysics Data System (ADS)

    Kim, Yoon-Ho; Choi, Chihwan; Lee, Kyu-Jung; Han, Donghyouck

    2009-08-01

    Experiments on evaporative spray cooling of flat heaters with plain and micro-porous coated surfaces were performed in this study. Micro-porous coated surfaces were made by using the DOM [Diamond particle, Omegabond 101, Methyl-Ethyl-Keton] coating method. In pure air-jet cooling, micro-porous coating did not show heat transfer improvement over plain surface. In spray cooling, however, three different flow patterns (complete wetting, evaporative wetting and dryout) were observed on both plain and micro-porous coated surfaces. The effects of various operating conditions, such as water flow rate, particle size, and coating thickness on the micro-porous coated surface were investigated. It was found that the level of surface wetting was an important factor in determining the performance of spray cooling. The level of surface wetting depended on the balance between the amount of liquid absorbed by capillary force over porosity and the amount of liquid evaporated. A micro-porous coated surface has a very high cooling capacity, especially in the evaporative wetting zone. The liquid flow rate and coating thickness are significant factors in the evaporative wetting zone, but are not in the complete wetting zone and the dryout zone.

  7. 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.

  8. 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. PMID:19094050

  9. Effects of different spray formulations on the reproductive parameters of engorged Rhipicephalus (Boophilus) microplus females detached from experimentally infested cattle.

    PubMed

    Cruz, Breno Cayeiro; Buzzulini, Carolina; Lopes, Welber Daniel Zanetti; Maciel, Willian Giquelin; Bichuette, Murilo Abud; Felippelli, Gustavo; Teixeira, Weslen Fabricio Pires; Soares, Vando Edésio; Gomes, Lucas Vinicius Costa; Prando, Luciana; Campos, Gabriel Pimentel; da Costa, Alvimar José

    2015-11-01

    This present study aimed to evaluate the deleterious effects of some commercially available spray formulations (15% Cypermethrin+25% Chlorpyriphos+1% Citronellal and 8% Cypermethrin+60% Ethion) on the reproductive parameters of engorged Rhipicephalus (Boophilus) microplus females that detached from experimentally infested cattle. The following reproductive parameters of engorged female ticks were analyzed: female weight, egg mass weight, percentage of hatchability, percentage of reduction in oviposition, percentage of reduction in hatchability, reproductive efficiency and percent control/efficacy of formulations for reproductive parameters. Our findings showed that although the strain R. (B.) microplus used in both experiments was thought to be sensitive to the test compounds because of the acaricidal efficacy observed throughout these trials, it was not possible to observe overall deleterious effects on the reproductive parameters of this tick species with both spray formulations. However, the 8% Cypermethrin+60% Ethion showed short-term significant effects on the weight of female ticks between the 14th and 16th days post-treatment and the weight of female and the egg mass weight between the 20th and 22nd days post-treatment. New studies should be conducted to show if these results regarding the reproductive parameters of fully engorged R. (B.) microplus females, combined with the acaricidal efficacy can be sufficient to reduce the number of chemical treatments administered to cattle. PMID:26427633

  10. Effects of different spray formulations on the reproductive parameters of engorged Rhipicephalus (Boophilus) microplus females detached from experimentally infested cattle.

    PubMed

    Cruz, Breno Cayeiro; Buzzulini, Carolina; Lopes, Welber Daniel Zanetti; Maciel, Willian Giquelin; Bichuette, Murilo Abud; Felippelli, Gustavo; Teixeira, Weslen Fabricio Pires; Soares, Vando Edésio; Gomes, Lucas Vinicius Costa; Prando, Luciana; Campos, Gabriel Pimentel; da Costa, Alvimar José

    2015-11-01

    This present study aimed to evaluate the deleterious effects of some commercially available spray formulations (15% Cypermethrin+25% Chlorpyriphos+1% Citronellal and 8% Cypermethrin+60% Ethion) on the reproductive parameters of engorged Rhipicephalus (Boophilus) microplus females that detached from experimentally infested cattle. The following reproductive parameters of engorged female ticks were analyzed: female weight, egg mass weight, percentage of hatchability, percentage of reduction in oviposition, percentage of reduction in hatchability, reproductive efficiency and percent control/efficacy of formulations for reproductive parameters. Our findings showed that although the strain R. (B.) microplus used in both experiments was thought to be sensitive to the test compounds because of the acaricidal efficacy observed throughout these trials, it was not possible to observe overall deleterious effects on the reproductive parameters of this tick species with both spray formulations. However, the 8% Cypermethrin+60% Ethion showed short-term significant effects on the weight of female ticks between the 14th and 16th days post-treatment and the weight of female and the egg mass weight between the 20th and 22nd days post-treatment. New studies should be conducted to show if these results regarding the reproductive parameters of fully engorged R. (B.) microplus females, combined with the acaricidal efficacy can be sufficient to reduce the number of chemical treatments administered to cattle.

  11. Theoretical analysis on spray performance of centrifugal spray nozzle

    NASA Astrophysics Data System (ADS)

    Zhou, Meng; Zhuang, Fengchen

    1991-08-01

    The relationships between spray characteristics and the configurational parameters of a centrifugal spray nozzle are presently explored via the theory of momentum conservation. Predicted mean spray angles are substantially in accord with the experimental data obtained; the predicted nozzle discharge coefficients are slightly lower than experimental data, due to the ignoring of fluid viscosity effects.

  12. 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.

  13. 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.

  14. 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.

  15. An Experimental Analysis Device for Obtaining Skid Line Limit Diagrams

    NASA Astrophysics Data System (ADS)

    Wanintradul, Chatchai; Gurumurthy, Gopinath T.; Smith, L. M.; Du, Changqing; Geng, Lumin; Zhou, D. J.; Hsiung, Ching-Kuo; Chen, Jizhou; Feng, Chao

    2011-08-01

    A novel design for a machine intended to measure directly various in-plane and contact normal forces acting upon a sheet metal specimen during a stretch-bend-draw process is proposed, in order to gain insight into the formation of skid line defects in sheet metal. The new machine, called a Stretch-Bend-Draw Simulator (SBDS) is designed specifically to be integrated into a typical laboratory tensile testing machine, thereby making it accessible to those researchers lacking the resources to acquire expensive additional tooling. As the strip of sheet metal is pulled over a round tool radius, the SBDS is shown to be capable of collecting pulling force, back force, tool normal force, and the corresponding draw bead clamping force. Analysis of the force data in conjunction with visual observations of the actual pulled specimens allows researchers to ascertain the conditions under which so-called skid lines arise. Experimental results, including a newly unveiled Skid Line Limit Diagram (SLLD), are provided and discussed. The SBDS appears to be a promising new electro-mechanical laboratory device for improving researchers' knowledge of the physical phenomena associated with skid lines in sheet metal products created in stamping dies.

  16. Experimental measurement-device-independent quantum key distribution.

    PubMed

    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

    2013-09-27

    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. PMID:24116758

  17. 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.

  18. 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.

  19. Shock waves in sprays: numerical study of secondary atomization and experimental comparison

    NASA Astrophysics Data System (ADS)

    Chauvin, A.; Daniel, E.; Chinnayya, A.; Massoni, J.; Jourdan, G.

    2016-07-01

    Numerical modeling of the interaction between a cloud of water droplets and a planar shock wave is compared with experimental data. The mathematical model relies on an Eulerian description of the dispersed phase with the assumption of dilute flows. It is shown that the secondary atomization of the droplets strongly influences the structure of both the shock wave and the induced flow. After shock loading, the individual liquid components generate daughter droplets, and the overall interphase surface per unit volume undergoes strong variations which modify the pressure relaxation process towards a dynamic and thermal equilibrium state. The experimental data enable one to determine the best analytical formulation of the droplet number production rate. Models of droplet number production rate are compared in order to highlight this feature. The model based on the assumption of linear variation of droplet diameter with time gives the best agreement between the numerical results and the experimental data.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Modified Spinning Top Homogeneous Spray Apparatus for Use in Experimental Respiratory Disease Studies

    PubMed Central

    Young, Harold W.; Larson, Edgar W.; Dominik, Joseph W.

    1974-01-01

    The May spinning top generator was adapted to a modified Henderson tube for producing large aerosol particles (>4 μm) to obtain almost exclusive upper respiratory tract deposition of infectious aerosols in exposed mice. The system was installed in a biological safety cabinet to permit experimentation with pathogens. A novel mechanism utilizing parts from a machinists micrometer and the mechanical stage from a light microscope was developed for the spinning top generator as a means for precisely positioning the liquid feed needle. Aerosol light-scatter properties were continuously analyzed to provide relative measures of particle size distribution and aerosol concentration. When mice were exposed to influenza virus aerosols in which none of the virus was contained in particles with aerodynamic diameters <4 μm, essentially all of the virus was deposited in the upper respiratory tract tissues. PMID:4451375

  5. Experimental investigation on the effect of injection conditions on spray and atomization of a centrifugal nozzle

    NASA Astrophysics Data System (ADS)

    Fan, Wei; Song, Haoyi; Fan, Zhencen; Zhao, Lin

    2013-05-01

    The effects of injection parameters on atomization of aviation kerosene (RP-3) were studied using a laser diffraction particle size analyzing system. The test results indicated that Sauter mean diameter (SMD) decreased with the increase of injection temperature. There was a critical temperature for flash evaporation, at which SMD had a sharp decrease. The critical temperature fell at first and then rose with the increase of injection pressure; however, the diameter of a centrifugal nozzle had little influence on the critical temperature. Sauter mean diameter didn't follow the conventional law after flash evaporation. A simple and empirical correlation between critical temperature for flash evaporation and injection parameters was developed from the experimental data, which can be used to evaluate critical temperature for flash evaporation.

  6. 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.

  7. Experimental flow studies in glaucoma drainage device development

    PubMed Central

    team, T. A.

    2001-01-01

    AIMS—(I) To examine whether small holes produced by 248 nm excimer laser ablation in a polymer substrate could consistently produce a pressure drop in the desired target range (5-15 mm Hg) at physiological aqueous flow rates for use as an internal flow restrictor in a glaucoma drainage device, and (ii) to investigate whether external leakage could be reduced in comparison with conventional tube and plate glaucoma drainage devices by redesigning the exterior cross sectional shape of the portion contained within the sclerocorneal tunnel.
METHODS—Single holes with target diameters of 10 µm, 15 µm, 20 µm, and 25 µm were drilled using a 248 nm excimer laser in sample discs (n=6 at each diameter) punched from a 75 µm thick polyimide sheet. Sample discs were tested in a flow rig designed to measure the pressure drop across the discs. Using filtered, degassed water at a flow rate of 1.4 µl/min repeated flow measurements were taken (n=6) for each disc. After flow testing, all discs were imaged using a scanning electron microscope and the dimensions of each hole were derived using image analysis software. In the external leakage study, corneoscleral buttons (n=13) were prepared from cadaver pig eyes and mounted on an artificial anterior chamber infused with Tyrode solution. After the pressure had stabilised, standard occluded silicone tube implants were inserted through 23 gauge needle stab incisions at the limbus. These were compared against prototype PMMA implants with a novel shape profile inserted through 1.15 mm width microvitreoretinal (MVR) stab incisions at the limbus. The infusion rate was maintained and a second pressure measurement was taken when the pressure had stabilised. The difference between the first and second pressure measurement was then compared, as an index of external leakage.
RESULTS—Ablated tubes were found to have a near perfect circular outline on both the entry and exit side. The observed pressure drops across the

  8. 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.

  9. Antistatic sprays

    NASA Technical Reports Server (NTRS)

    Ming, James E.

    1989-01-01

    Antistatic sprays from several different manufacturers are examined. The sprays are examined for contamination potential (i.e., outgassing and nonvolatile residue), corrosiveness on an aluminum mirror surface, and electrostatic effectiveness. In addition, the chemical composition of the antistatic sprays is determined by infrared spectrophotometry, mass spectrometry, and ultraviolet spectrophotometry. The results show that 12 of the 17 antistatic sprays examined have a low contamination potential. Of these sprays, 7 are also noncorrosive to an aluminum surface. And of these, only 2 demonstrate good electrostatic properties with respect to reducing voltage accumulation; these sprays did not show a fast voltage dissipation rate however. The results indicate that antistatic sprays can be used on a limited basis where contamination potential, corrosiveness, and electrostatic effectiveness is not critical. Each application is different and proper evaluation of the situation is necessary. Information on some of the properties of some antistatic sprays is presented in this document to aid in the evaluation process.

  10. 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

  11. 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.

  12. 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.

  13. "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.

  14. Experimental investigation of aerodynamic devices for wind turbine rotational speed control: Phase II

    SciTech Connect

    Miller, S L

    1996-02-01

    An experimental investigation was undertaken to further evaluate and enhance the performance of an aerodynamic device for wind turbine overspeed protection and power modulation applications. The trailing-edge device, known as the Spoiler-Flap, was examined in detail during wind tunnel tests. The impact of hp length, vent angle, pivot point and chord variations on aerodynamic and hinge moment characteristics were evaluated and a best overall configuration was identified. Based on this effort, a 40% chord device with a 1% hp length and 40 degree vent angle offers improved performance potential for wind turbine applications. This specific configuration appears to offer good suction coefficient performance for both turbine power modulation and overspeed (i.e., aerodynamic braking) applications. Device hinge moment loads improved (compared to other devices investigated) in magnitude and the impact of surface roughness was found to be minimal.

  15. Experimental/computational analysis of active cooling of stacked device using multidimensional configured thermoelectric modules

    NASA Astrophysics Data System (ADS)

    Patel, Vaidehi Bharat

    Stacked devices are currently used widely because of their smaller footprint and corresponding ability to accommodate heterogeneous devices such as memory and logic and enable a silicon efficiency greater than 100%. This configuration will results in thermal management challenges due to the torturous heat dissipation path. In addition, the non-uniformity in chip power distribution results in an increased spreading resistance as well as temperature gradient at the device level that can degrade performance and reliability. In this study the Thermoelectric Modules were configured in a multidimensional form surrounding a three dimensional cold core. The corresponding Computational Fluid Dynamics model is validated using the experimental data.

  16. 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.

  17. Electrokinetically pumped high pressure sprays

    SciTech Connect

    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.

  18. 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.

  19. 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.

  20. A new device-independent dimension witness and its experimental implementation

    NASA Astrophysics Data System (ADS)

    Cai, Yu; Bancal, Jean-Daniel; Romero, Jacquiline; Scarani, Valerio

    2016-07-01

    A dimension witness is a criterion that sets a lower bound on the dimension needed to reproduce the observed data. Three types of dimension witnesses can be found in the literature: device-dependent ones, in which the bound is obtained assuming some knowledge on the state and the measurements; device-independent prepare-and-measure ones, that can be applied to any system including classical ones; and device-independent Bell-based ones, that certify the minimal dimension of some entangled systems. Here we consider the Collins-Gisin-Linden-Massar-Popescu Bell-type inequality for four outcomes. We show that a sufficiently high violation of this inequality witnesses d≥slant 4 and present a proof-of-principle experimental observation of such a violation. This presents a first experimental violation of the third type of dimension witness beyond qutrits.

  1. [Sutureless hepatic transection using a new radiofrequency assisted device. Theoretical model, experimental study and clinic trial].

    PubMed

    Martínez-Serrano, María Ángeles; Grande, Luis; Burdío, Fernando; Berjano, Enrique; Poves, Ignasi; Quesada, Rita

    2011-03-01

    The ideal instrument for performing hepatic transection should combine safe and rapid haemostasis in a single tool. We present a new multidisciplinary investigation designed to develop a hepatic transection device assisted by radiofrequency (RF); the investigation included: a computerised theoretical model, and experimental study and a clinical trial of this device. The theoretic modelling was performed by computer, based on the Finite Elements Method (FEM), with the objective of studying the distribution of electrical energy and temperature in the tissue, and to assess the effect of the characteristics of the instrument. The experimental study, based on an in vivo porcine model, suggested that the new instrument would allow the transection velocity of the hepatic parenchyma to be increased with lower bleeding per transection area compared with other techniques extensively used in liver surgery. These data should enable the first phase of clinical trial to be conducted, with preliminary results that suggest that the new device is safe and effective.

  2. 42 CFR 405.209 - Payment for a non-experimental/investigational (Category B) device.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 2 2011-10-01 2011-10-01 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...

  3. 42 CFR 405.205 - Coverage of a non-experimental/investigational (Category B) device.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 2 2011-10-01 2011-10-01 false Coverage of a non-experimental/investigational (Category B) device. 405.205 Section 405.205 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...

  4. 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...

  5. 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

  6. 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].

  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. 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.

  9. Doppler radar device as a useful tool to quantify the liveliness of the experimental animal.

    PubMed

    Kropveld, D; Chamuleau, R A

    1993-07-01

    The Doppler radar device which is described here is shown to be a reliable and accurate device to quantify the liveliness of an experimental rat. During recording the animal did not seem to be disturbed in any way by the device. It could stay in its normal cage, move freely, walk around and eat and drink ad libitum. Measurement did not require extra light, sound or other stimuli. Interpretation of the data was easy. The computer which samples the Doppler radar output signal generates activity curves which were easily interpreted for different ranges of vitality, varying between high liveliness and apnoea or cardiac arrest. The apparatus is low priced, and simple to build and use.

  10. An experimental device for investigating the force and power requirements of a powered gait orthosis.

    PubMed

    Ruthenberg, B J; Wasylewski, N A; Beard, J E

    1997-04-01

    The Powered Gait Orthosis (PGO) is a powered exoskeleton developed as an experimental device to provide bipedal locomotion to individuals with physical impairment. The current prototype consists of a single degree of freedom (DOF) system for each leg, providing power and proper displacement required for bipedal locomotion. It is the goal of this research to obtain the forces that are present in the device while it is in normal operation. In addition, the time ratio of the hip function generator has been varied to determine the effect that different time ratios have on system forces and required user energy. The time ratio is the relationship between the time period that the thigh is in swing phase and when it is in support phase. Knowing the forces in the system and the optimal time ratio will allow for the design and construction of a feasible device for the rehabilitation and assistance of individuals who have lost the ability to walk. PMID:9108347

  11. On the experimental testing of fine Nitinol wires for medical devices.

    PubMed

    Henderson, E; Nash, D H; Dempster, W M

    2011-04-01

    Nitinol, a nickel titanium alloy, is widely used as a biocompatible metal with applications in high strain medical devices. The alloy exhibits both superelasticity and thermal shape memory behaviour. Basic mechanical properties can be established and are provided by suppliers; however the true stress-strain response under repeated load is not fully understood. It is essential to know this behaviour in order to design devices where failure by fatigue may be possible. The present work develops an approach for characterising the time varying mechanical properties of fine Nitinol wire and investigates processing factors, asymmetric stress-strain behaviour, temperature dependency, strain rate dependency and the material response to thermal and repeated mechanical loading. Physically realistic and accurately determined mechanical properties are provided in a format suitable for use in finite element analysis for the design of medical devices. Guidance is also given as to the most appropriate experimental set up procedures for gripping and testing thin Nitinol wire.

  12. An experimental investigation on the spray flow exhausted from a co-swirling air-blast nozzle

    NASA Astrophysics Data System (ADS)

    Dvorak, Daniel Dean

    The velocity field for a spray produced by an air-blast atomizer is measured using Particle Image Velocimetry (PIV). These measurements are conducted at a variety of input liquid and air mass flow rates producing many different air to liquid mass flow ratios (ALR). The experiment is repeated with two different liquids, water and a hydrocarbon based fuel substitute. It is found that the velocity field depends heavily on the type of fluid used as opposed to the ALR. The experiments are repeated using a Stereoscopic Particle Image Velocimetry (SPIV) measurement technique. These results are compared to the 2D PIV results, and the differences are discussed. Finally, the 2D PIV and SPIV results are compared to existing Laser Doppler Velocimetry (LDV) results. It is seen that the results from the two different techniques are not well correlated.

  13. Nitroglycerin Spray

    MedlinePlus

    ... artery disease (narrowing of the blood vessels that supply blood to the heart). The spray may also ... Innopran XL), sotalol (Betapace, Sorine), and timolol; calcium channel blockers such as amlodipine (Norvasc, in Tekamlo), diltiazem ( ...

  14. 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.

  15. 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.

  16. 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.

  17. Theoretical and Experimental Exploration of Breakdown Phenomena in an Argon-Filled GaP Device

    NASA Astrophysics Data System (ADS)

    Kurt, H. Hilal; Tanrıverdi, Evrim; Kurt, Erol

    2016-08-01

    A plasma device with large diameter and short interelectrode distance has been designed and implemented. Theoretical modeling and simulations have been carried out for different interelectrode distances, and experimental results obtained under different pressures p, both with argon atmosphere. The device produces direct-current (dc) discharges in the parallel-plate electrode configuration, with gallium phosphide (GaP) semiconductor at one side and SnO2-coated glass conducting material at the other side, separated by gas medium with width of 50 μm to 500 μm. The device can be operated under different values of interelectrode distance d, applied voltage U, and gas pressure p. Current-voltage characteristics and breakdown voltages have been found experimentally and theoretically. In addition, theoretical breakdown curves have been derived from simulations. The theory can also identify the space-charge density, thermal electron velocity, reduced electric field strength ( E/ N), electron density ne, and secondary-electron emission ( γ). Comparison between experiment and theory shows that the theory can estimate the breakdown very well for low pressure and small interelectrode gap.

  18. Theoretical and experimental study of nanoporous silicon photonic microcavity optical sensor devices

    NASA Astrophysics Data System (ADS)

    Patel, P. N.; Mishra, Vivekanand; Panchal, A. K.

    2012-09-01

    This paper reports the theoretical and experimental study of one-dimensional (1D) multilayer nanoporous silicon (NPS) photonic band gap (PBG) microcavity (MC) structures for optical sensor device applications. A theoretical framework to model the reflectance spectra relying on the Bruggeman's effective medium approximation (BEMA) and the transfer matrix method (TMM) was established for the 1D nanoporous silicon microcavity (1D-NPSMC) optical sensor device structures. Based on the theoretical background, 1D-NPSMC sensor device structures were fabricated using electrochemical dissolution of silicon wafer in hydrofluoric (HF) acid. The refractive index of the 1D-NPSMC structures was tuned by changing current density and the thickness was tuned by changing the etching time. Wavelength shifts (Δλ) in the measured reflectance spectra were analyzed for the detection of the analyte in the porous structure. The sensing device performance was tested by different organic solvents, which showed good linear relation between the refractive index of analyte inside the pores and the wavelength shift. The application of proposed structures can be extended for the optical sensing of chemicals, gas, environmental pollutants, pathogens etc.

  19. An experimental spinal cord injury rat model using customized impact device: A cost-effective approach

    PubMed Central

    Vijayaprakash, K.M.; Sridharan, N.

    2013-01-01

    Till date, NYU MASCIS (New York University, Multicenter Animal Spinal Cord Injury Study) impactor and Ohio State University electromagnetic spinal cord injury device impactor were under use for simulating an experimental spinal cord injury in rodents; functional recovery being assessed through Basso, Beattie and Bresnahan (BBB) scoring method which is an open field behavior based scoring system. Although, the cited impactors are state-of-art devices, affordability to scientists in developing and under developed countries is questionable. Since the acquisition of these impact devices are expensive, we designed a customized impact device based on the requirement, satisfying all the parameters to withstand a standard animal model for contusion type of spinal cord injury at the thoracic level without compromising the lesion reproducibility. Here, a spinal cord contusion is created using a blunt-force impactor in male Wistar rats. Our method gave consistent lesion effects as evaluated by behavior scoring methods. All the animals showed equal degree of performance in tests like narrow beam, inclined plane and horizontal ladder and in BBB scores (open field locomotor test). The aim of presenting our experience is to reinstate the fact that lack of affordability to get sophisticated instrumentation need not be a hurdle in the pursuit of science. PMID:23960429

  20. An experimental spinal cord injury rat model using customized impact device: A cost-effective approach.

    PubMed

    Vijayaprakash, K M; Sridharan, N

    2013-07-01

    Till date, NYU MASCIS (New York University, Multicenter Animal Spinal Cord Injury Study) impactor and Ohio State University electromagnetic spinal cord injury device impactor were under use for simulating an experimental spinal cord injury in rodents; functional recovery being assessed through Basso, Beattie and Bresnahan (BBB) scoring method which is an open field behavior based scoring system. Although, the cited impactors are state-of-art devices, affordability to scientists in developing and under developed countries is questionable. Since the acquisition of these impact devices are expensive, we designed a customized impact device based on the requirement, satisfying all the parameters to withstand a standard animal model for contusion type of spinal cord injury at the thoracic level without compromising the lesion reproducibility. Here, a spinal cord contusion is created using a blunt-force impactor in male Wistar rats. Our method gave consistent lesion effects as evaluated by behavior scoring methods. All the animals showed equal degree of performance in tests like narrow beam, inclined plane and horizontal ladder and in BBB scores (open field locomotor test). The aim of presenting our experience is to reinstate the fact that lack of affordability to get sophisticated instrumentation need not be a hurdle in the pursuit of science. PMID:23960429

  1. 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.

  2. 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.

  3. Experimental control of a fast chaotic time-delay opto-electronic device

    NASA Astrophysics Data System (ADS)

    Blakely, Jonathan Neal

    2003-10-01

    The focus of this thesis is the experimental investigation of the dynamics and control of a new type of fast chaotic opto-electronic device: an active interferometer with electronic bandpass filtered delayed feedback displaying chaotic oscillations with a fundamental frequency as high as 100 MHz. To stabilize the system, I introduce a new form of delayed feedback control suitable for fast time-delay systems. The method provides a new tool for the fundamental study of fast dynamical systems as well as for technological exploitation of chaos. The new opto-electronic device consists of a semiconductor laser, a Mach-Zehnder interferometer, and an electronic feedback loop. The device offers a high degree of design flexibility at a much lower cost than other known sources of fast optical chaos. Both the nonlinearity and the timescale of the oscillations are easily manipulated experimentally. To characterize the dynamics of the system, I observe experimentally its behavior in the time and frequency domains as the feedback-loop gain is varied. The system displays a route to chaos that begins with a Hopf bifurcation from a steady state to a periodic oscillation at the so-called fundamental frequency. Further bifurcations give rise to a chaotic regime with a broad, flattened power spectrum. I develop a mathematical model of the device that shows very good agreement with the observed dynamics. To control chaos in the device, I introduce a new control method suitable for fast time-delay systems, in particular. The method is a modification of a well known control approach called time-delay autosynchronization (TDAS) in which the control perturbation is formed by comparing the current value of a system variable to its value at a time in the past equal to the period of the orbit to be stabilized. The current state of a time-delay dynamical system retains a memory of the state of the system one feedback delay time in the past. As a result, the past state of the system can be used

  4. Experimental Observation of a Periodically Oscillating Plasma Sphere in a Gridded Inertial Electrostatic Confinement Device

    SciTech Connect

    Park, J.; Nebel, R.A.; Stange, S.; Murali, S. Krupakar

    2005-07-01

    The periodically oscillating plasma sphere (POPS) [D. C. Barnes and R. A. Nebel, Phys. Plasmas 5, 2498 (1998).] oscillation has been observed in a gridded inertial electrostatic confinement device. In these experiments, ions in the virtual cathode exhibit resonant behavior when driven at the POPS frequency. Excellent agreement between the observed POPS resonance frequency and theoretical predictions has been observed for a wide range of potential well depths and for three different ion species. The results provide the first experimental validation of the POPS concept proposed by Barnes and Nebel [R. A. Nebel and D. C. Barnes, Fusion Technol. 34, 28 (1998).].

  5. 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.

  6. Experimental analysis of the surface roughness evolution of etched glass for micro/nanofluidic devices

    NASA Astrophysics Data System (ADS)

    Ren, J.; Ganapathysubramanian, B.; Sundararajan, S.

    2011-02-01

    Roughness of channel surfaces, both deterministic and random, is known to affect the fluid flow behavior in micro/nanoscale fluidic devices. This has relevance particularly for applications involving non-Newtonian fluids, such as in biomedical lab-on-chip devices. While several studies have investigated effects of relative large, deterministic surface structures on fluid flow, the effect of random roughness on microfluidic flow remains relatively unexplored. In this study, the effects of processing conditions for wet etching of glass including etching time and etching orientation on centre-line average (Ra) and the autocorrelation length (ACL) were investigated. Statistical distribution of the roughness was also studied. Results indicated that ACL can be tailored in the range of 1-4 µm by changing etching time in horizontal etching while Ra was found to increase weakly with etching time in all three etching orientations. Analysis of the experimental data using the Kolmogorov-Smirnov goodness-of-fit hypothesis test shows that the glass surface roughness does not follow a Gaussian distribution, as is typically assumed in the literature. Instead, the T location-scale distribution fits the roughness data with 1.11% error. These results provide promising insights into tailoring surface roughness for improving microfluidic devices.

  7. 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…

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

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

    The quantum Hall effect provides a universal standard for electrical resistance that is theoretically based on only the Planck constant h and the electron charge e. Currently, this standard is implemented in GaAs/AlGaAs, but graphene's electronic properties have given hope for a more practical device. Here, we demonstrate that the experimental conditions necessary for the operation of devices made of high-quality graphene grown by chemical vapour deposition on silicon carbide can be extended and significantly relaxed compared with those for state-of-the-art GaAs/AlGaAs devices. In particular, the Hall resistance can be accurately quantized to within 1 × 10-9 over a 10 T wide range of magnetic flux density, down to 3.5 T, at a temperature of up to 10 K or with a current of up to 0.5 mA. This experimental simplification highlights the great potential of graphene in the development of user-friendly and versatile quantum standards that are compatible with broader industrial uses beyond those in national metrology institutes. Furthermore, the measured agreement of the quantized Hall resistance in graphene and GaAs/AlGaAs, with an ultimate uncertainty of 8.2 × 10-11, supports the universality of the quantum Hall effect. This also provides evidence of the relation of the quantized Hall resistance with h and e, which is crucial for the new Système International d'unités to be based on fixing such fundamental constants of nature.

  9. Electromagnetic Controlled Cortical Impact Device for Precise, Graded Experimental Traumatic Brain Injury

    PubMed Central

    BRODY, DAVID L.; DONALD, CHRISTINE Mac; KESSENS, CHAD C.; YUEDE, CARLA; PARSADANIAN, MAIA; SPINNER, MIKE; KIM, EDDIE; SCHWETYE, KATHERINE E.; HOLTZMAN, DAVID M.; BAYLY, PHILIP V.

    2008-01-01

    Genetically modified mice represent useful tools for traumatic brain injury (TBI) research and attractive preclinical models for the development of novel therapeutics. Experimental methods that minimize the number of mice needed may increase the pace of discovery. With this in mind, we developed and characterized a prototype electromagnetic (EM) controlled cortical impact device along with refined surgical and behavioral testing techniques. By varying the depth of impact between 1.0 and 3.0 mm, we found that the EM device was capable of producing a broad range of injury severities. Histologically, 2.0-mm impact depth injuries produced by the EM device were similar to 1.0-mm impact depth injuries produced by a commercially available pneumatic device. Behaviorally, 2.0-, 2.5-, and 3.0-mm impacts impaired hidden platform and probe trial water maze performance, whereas 1.5-mm impacts did not. Rotorod and visible platform water maze deficits were also found following 2.5- and 3.0-mm impacts. No impairment of conditioned fear performance was detected. No differences were found between sexes of mice. Inter-operator reliability was very good. Behaviorally, we found that we could statistically distinguish between injury depths differing by 0.5 mm using 12 mice per group and between injury depths differing by 1.0 mm with 7-8 mice per group. Thus, the EM impactor and refined surgical and behavioral testing techniques may offer a reliable and convenient framework for preclinical TBI research involving mice. PMID:17439349

  10. Electromagnetic controlled cortical impact device for precise, graded experimental traumatic brain injury.

    PubMed

    Brody, David L; Mac Donald, Christine; Kessens, Chad C; Yuede, Carla; Parsadanian, Maia; Spinner, Mike; Kim, Eddie; Schwetye, Katherine E; Holtzman, David M; Bayly, Philip V

    2007-04-01

    Genetically modified mice represent useful tools for traumatic brain injury (TBI) research and attractive preclinical models for the development of novel therapeutics. Experimental methods that minimize the number of mice needed may increase the pace of discovery. With this in mind, we developed and characterized a prototype electromagnetic (EM) controlled cortical impact device along with refined surgical and behavioral testing techniques. By varying the depth of impact between 1.0 and 3.0 mm, we found that the EM device was capable of producing a broad range of injury severities. Histologically, 2.0-mm impact depth injuries produced by the EM device were similar to 1.0-mm impact depth injuries produced by a commercially available pneumatic device. Behaviorally, 2.0-, 2.5-, and 3.0-mm impacts impaired hidden platform and probe trial water maze performance, whereas 1.5-mm impacts did not. Rotorod and visible platform water maze deficits were also found following 2.5- and 3.0-mm impacts. No impairment of conditioned fear performance was detected. No differences were found between sexes of mice. Inter-operator reliability was very good. Behaviorally, we found that we could statistically distinguish between injury depths differing by 0.5 mm using 12 mice per group and between injury depths differing by 1.0 mm with 7-8 mice per group. Thus, the EM impactor and refined surgical and behavioral testing techniques may offer a reliable and convenient framework for preclinical TBI research involving mice.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Successful Reconstruction of Nerve Defects Using Distraction Neurogenesis with a New Experimental Device

    PubMed Central

    Yousef, Mohamed Abdelhamid Ali; Dionigi, Paolo; Marconi, Stefania; Calligaro, Alberto; Cornaglia, Antonia Icaro; Alfonsi, Enrico; Auricchio, Ferdinando

    2015-01-01

    Introduction: Repair of peripheral nerve injuries is an intensive area of challenge and research in modern reconstructive microsurgery. Intensive research is being carried out to develop effective alternatives to the standard nerve autografting, avoiding its drawbacks. The aim of the study was to evaluate the effectiveness of a newly designed mechanical device for the reconstruction of the sciatic nerve in rats in comparison to nerve autografting and to assess the pain during the period of distraction neurogenesis. Methods: Fourteen Sprague Dawley rats were used and randomly assigned into 2 groups with 7 rats in each group; group A (Nerve Autografting group) in which a 10-mm segment of the sciatic nerve was resected and rotated 180 degrees, then primary end-to-end neurorrhaphy was performed in the reverse direction; group B (Nerve Lengthening group) in which the mechanical device was inserted after surgical resection of 10 mm of the sciatic nerve, then secondary end-to-end neurorrhaphy was performed after completing the nerve lengthening. Thirteen weeks later, assessment of the functional sciatic nerve recovery using static sciatic index (SSI) was performed. Furthermore, fourteen weeks after the nerve resection, assessment of the nerve regeneration with electrophysiological study and histological analysis were performed. Also, gastrocnemius wet weight was measured. For pain assessment in group B, Rat Grimace Scale (RGS) score was used. Results: Significantly better functional recovery rate (using the SSI) was reported in the nerve lengthening group in comparison to autografting group. Also, a statistically significant higher nerve conduction velocity was detected in the nerve lengthening group. On histological analysis of the distal nerve section at 3 mm distal to the nerve repair site, significant myelin sheath thickness was detected in the nerve lengthening group. Discussion: Distraction neurogenesis with the new experimental device is a reliable therapeutic

  17. 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.

  18. 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. PMID:25200116

  19. A new mechanical device for circular compression anastomosis. Preliminary results of animal and clinical experimentation.

    PubMed Central

    Rosati, R; Rebuffat, C; Pezzuoli, G

    1988-01-01

    The authors report the preliminary results obtained in animal and clinical experimentation of a new mechanical device for circular anastomosis which they have developed. It is a gun that places an apparatus consisting of three polypropylene rings that, through the compression among them of the severed edges of the bowel, realize a sutureless anastomosis and are spontaneously evacuated. Fifty-eight colonic anastomoses were performed in dogs with this device; 23 stapled colonic anastomoses were also executed concurrently. Forty-four animals underwent a relaparotomy to remove the colonic specimen containing the anastomoses. Bursting pressure and the histologic features of the anastomoses were evaluated at different time intervals after operation. A good healing of all compression anastomoses was observed, thereby allowing them to initiate the experience in humans. Thirteen anastomoses (6 colorectal extraperitoneal, 1 colorectal intraperitoneal, 5 colocolonic, 1 ileorectal) were performed at the 1st Surgical Department, Milan University. One subclinical leakage (7.7%) spontaneously healed in a few days. No stenoses were observed. Images Fig. 1. Fig. 2., Fig. 4., Fig. 6. Fig. 3., Fig. 5., Fig. 7. Fig. 8. Fig. 9. PMID:3345111

  20. 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

  1. Experimental measurement-device-independent quantum key distribution with imperfect sources

    NASA Astrophysics Data System (ADS)

    Tang, Zhiyuan; Wei, Kejin; Bedroya, Olinka; Qian, Li; Lo, Hoi-Kwong

    2016-04-01

    Measurement-device-independent quantum key distribution (MDI-QKD), which is immune to all detector side-channel attacks, is the most promising solution to the security issues in practical quantum key distribution systems. Although several experimental demonstrations of MDI-QKD have been reported, they all make one crucial but not yet verified assumption, that is, there are no flaws in state preparation. Such an assumption is unrealistic and security loopholes remain in the source. Here we present a MDI-QKD experiment with the modulation error taken into consideration. By applying the loss-tolerant security proof by Tamaki et al. [Phys. Rev. A 90, 052314 (2014)], 10.1103/PhysRevA.90.052314, we distribute secure keys over fiber links up to 40 km with imperfect sources, which would not have been possible under previous security proofs. By simultaneously closing loopholes at the detectors and a critical loophole—modulation error in the source, our work shows the feasibility of secure QKD with practical imperfect devices.

  2. Thermally sprayed coatings: Aluminum on lead

    SciTech Connect

    Usmani, S.; Czajkowski, C.J.; Zatorski, R.

    1999-09-01

    An experimental program to determine the feasibility of thermally spraying aluminum on a lead substrate was initiated in support of the accelerator production of tritium (APT) Project for the US Department of Energy. The program consisted of two distinct parts: (1) the characterization of the thermally sprayed coatings, including microhardness testing, effects of heating, and microstructure and porosity determinations, and (2) effects of mercury doping and heat treatments on the thermally sprayed composite. The project determined that aluminum could successfully be thermally sprayed onto the lead. The coatings had a dense microstructure, with a Vicker's Pyramid Hardness (VPH) of about 60, and a maximum porosity (found in strips on the samples) of 12%.

  3. 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.

  4. 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.

  5. Stretching DNA by electric field and flow field in microfluidic devices: An experimental validation to the devices designed with computer simulations

    PubMed Central

    Lee, Cheng-Han; Hsieh, Chih-Chen

    2013-01-01

    We examined the performance of three microfluidic devices for stretching DNA. The first device is a microchannel with a contraction, and the remaining two are the modifications to the first. The modified designs were made with the help of computer simulations [C. C. Hsieh and T. H. Lin, Biomicrofluidics 5(4), 044106 (2011) and C. C. Hsieh, T. H. Lin, and C. D. Huang, Biomicrofluidics 6, 044105 (2012)] and they were optimized for operating with electric field. In our experiments, we first used DC electric field to stretch DNA. However, the experimental results were not even in qualitative agreement with our simulations. More detailed investigation revealed that DNA molecules adopt a globular conformation in high DC field and therefore become more difficult to stretch. Owing to the similarity between flow field and electric field, we turned to use flow field to stretch DNA with the same devices. The evolution patterns of DNA conformation in flow field were found qualitatively the same as our prediction based on electric field. We analyzed the maximum values, the evolution and the distributions of DNA extension at different Deborah number in each device. We found that the shear and the hydrodynamic interaction have significant influence on the performance of the devices. PMID:24404001

  6. 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.

  7. Splash and spray from road vehicles and associated topics: A bibliography

    NASA Astrophysics Data System (ADS)

    Cowperthwaite, N. A.

    1984-06-01

    Approximately 113 citations are given on some aerodynamic characteristics of motor vehicles on various road surfaces and under varying conditions. Some topics covered include: wet road friction at high speeds; water spray generated by road vehicles; effects of visibility on driver performance; spray patterns and suppression; highway and vehicular safety; drag and spray produced by pneumatic wheels moving through water layers; spray reducing devices for vehicles; surfaces laid to reduce splash and spray; water surface depth measurement; and pneumatic tire hydroplaning.

  8. Reactive spraying of nickel-aluminide coatings

    NASA Astrophysics Data System (ADS)

    Deevi, S. C.; Sikka, V. K.; Swindeman, C. J.; Seals, R. D.

    1997-09-01

    Reactive spraying of nickel aluminides was accomplished via reaction synthesis techniques in which nickel and aluminum powders were fed through a direct- current plasma torch onto carbon steel substrates. The as- sprayed coatings obtained by reactive spraying were characterized by x- ray diffraction and microscopic techniques. Reactive spraying of nickel and aluminum resulted in coatings consisting of Ni, Al, Ni 3Al, NiAl3, Ni5Al3, NiAl, and Al2O3, depending on the experimental conditions. Nickel aluminide phases observed in plasma spray depositions were compared with the phases obtained by combustion synthesis techniques, and the formation of phases in reactive spraying was attributed to the exothermic reaction between splats of aluminum and nickel. Primary and secondary reactions leading to the formation of nickel aluminides were also examined. The splat thickness and the reaction layer suppressed the formation of desired equilibrium phases such as Ni3Al and NiAl. As- sprayed coatings were annealed to enhance the diffusional reactions between the product phases and aluminum and nickel. Coatings obtained by reactive spraying of elemental powders were compared with as- sprayed and annealed coatings obtained with a bond coat material in which nickel was deposited onto aluminum particles.

  9. 10 CFR 431.262 - Definitions concerning commercial prerinse spray valves.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Prerinse Spray Valves § 431.262 Definitions... spray valve means a handheld device designed and marketed for use with commercial dishwashing and...

  10. 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.

  11. Final Report: Fundamental Studies of Spray Combustion, March 15, 1987 - July 14, 1999

    SciTech Connect

    Li, S.C.; Libby, Paul; Williams, Furman

    1999-07-14

    The authors research on spray combustion, involving both experimental and theoretical components, has addressed droplet and spray characteristics in laminar counterflowing streams, laminar counterflow spray diffusion flames, and impingement of sprays on hot surfaces, both with and without a flame present, and flame structure and flame chemistry.

  12. Measurements in liquid fuel sprays

    NASA Technical Reports Server (NTRS)

    Chigier, N.; Mao, C. P.

    1985-01-01

    A ground test facility is being established at NASA Lewis Research Center to simulate the environmental and flight conditions needed to study adverse weather effects. One of the most important components is the water spray system which consists of many nozzles fitted on spray bars. Water is injected through air-assisted atomizers to generate uniform size drops to simulate icing in clouds. The primary objective is to provide experimental data on drop size distribution over a wide range of operating conditions. Correlation equations for mean drop size and initial injection parameters are being determined to assist in the design and modification of the Altitude Wind Tunnel. Special emphasis is being placed on the study of the aerodynamic structure of the air-assisted atomizer sprays. Detailed measurements of the variation of drop size distribution and velocity as a function of time and space are being made. Accurate initial and boundary conditions are being provided for computer model evaluation.

  13. Deposition Behavior of Semi-Molten Spray Particles During Flame Spraying of Porous Metal Alloy

    NASA Astrophysics Data System (ADS)

    Yao, Jian-Tao; Ren, Jun-Qiang; Huo, Hui-Bin; Yang, Guan-Jun; Li, Cheng-Xin; Li, Chang-Jiu

    2014-08-01

    Porous 316L stainless steel deposits were fabricated by flame spraying semi-molten particles with different melting degrees and spray angles to understand the deposition behavior of semi-molten spray particles. The effects of spray angle relative on the deposition efficiency and deposit porosity were investigated. The morphology of individual splats deposited on flat surface at different angles was examined. The results show that the spray angle had a significant influence on the deposit porosity, pore structure, and deposition efficiency. The slipping of solid core in semi-molten spray particle was clearly observed when semi-molten particles impacted on the polished substrate with an inclined angle. A random model was proposed to simulate the process of particle deposition. It was found that after considering the effects of both solid particle slipping upon impact and particle melting degree, the porosity calculated by simulation with the model agreed well with the experimental observation.

  14. 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.

  15. 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.

  16. 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.

  17. 42 CFR 405.209 - Payment for a non-experimental/investigational (Category B) device.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Medical Services Coverage Decisions That Relate to Health Care Technology § 405.209 Payment for a non... used device serving the same medical purpose that has been approved or cleared for marketing by the FDA....

  18. 42 CFR 405.209 - Payment for a non-experimental/investigational (Category B) device.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Medical Services Coverage Decisions That Relate to Health Care Technology § 405.209 Payment for a non... used device serving the same medical purpose that has been approved or cleared for marketing by the FDA....

  19. 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.

  20. Influence of fish aggregating devices (FADs) on anti-predator behaviour within experimental mesocosms.

    PubMed

    Sinopoli, Mauro; Cattano, Carlo; Andaloro, Franco; Sarà, Gianluca; Butler, Christopher M; Gristina, Michele

    2015-12-01

    Commercial fishers have used fish aggregating devices throughout the Mediterranean Sea for over 40 years. These devices attract numerous predatory and forage species in both coastal and offshore environments. This study examined the influence of fish aggregating devices on schooling and aggregating behaviour by small forage fish in quasi-natural mesocosms. Anti-predator behaviour was evaluated for juvenile Caranx crysos under a variety of treatment conditions. Results suggest that, in the absence of physical structure, C. crysos first respond to a predatory threat by forming a school. When a physical structure is present, however, C. crysos show an occasional tendency to aggregate near the structure. These results suggest that a threatened prey species can change their defensive strategy against predatory behaviour. Further examination is required to explain if fish aggregating devices can increase survival rates of post-larval and juvenile prey species in the southern Mediterranean Sea. Management agencies should consider the relationship between the use of fish aggregating devices by commercial fisheries and the potential influence such devices possess on population dynamics of aggregating fish species. PMID:26525872

  1. Influence of fish aggregating devices (FADs) on anti-predator behaviour within experimental mesocosms.

    PubMed

    Sinopoli, Mauro; Cattano, Carlo; Andaloro, Franco; Sarà, Gianluca; Butler, Christopher M; Gristina, Michele

    2015-12-01

    Commercial fishers have used fish aggregating devices throughout the Mediterranean Sea for over 40 years. These devices attract numerous predatory and forage species in both coastal and offshore environments. This study examined the influence of fish aggregating devices on schooling and aggregating behaviour by small forage fish in quasi-natural mesocosms. Anti-predator behaviour was evaluated for juvenile Caranx crysos under a variety of treatment conditions. Results suggest that, in the absence of physical structure, C. crysos first respond to a predatory threat by forming a school. When a physical structure is present, however, C. crysos show an occasional tendency to aggregate near the structure. These results suggest that a threatened prey species can change their defensive strategy against predatory behaviour. Further examination is required to explain if fish aggregating devices can increase survival rates of post-larval and juvenile prey species in the southern Mediterranean Sea. Management agencies should consider the relationship between the use of fish aggregating devices by commercial fisheries and the potential influence such devices possess on population dynamics of aggregating fish species.

  2. 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

    2006-03-01

    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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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. PMID:21280830

  8. Fentanyl Sublingual Spray

    MedlinePlus

    ... a solution (liquid) to spray sublingually (under the tongue). It is used as needed to treat breakthrough ... the nozzle into your mouth and under your tongue. Squeeze your fingers and thumb together to spray ...

  9. Mometasone Nasal Spray

    MedlinePlus

    ... allergies. It is also used to treat nasal polyps (swelling of the lining of the nose). Mometasone ... are using mometasone nasal spray to treat nasal polyps, it is usually sprayed in each nostril once ...

  10. 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.

  11. Expandable device type III for easy and reliable approximation of dissection layers in sutureless aortic anastomosis. Ex vivo experimental study.

    PubMed

    Nazari, Stefano

    2010-02-01

    In past years, we developed expandable devices (type I and II) for sutureless aortic anastomosis. We have now further modified the device (type III) incorporating a second expandable ring, external to the main one, which can be operated contrariwise in such a way that the aortic wall (i.e. the dissection layers) is compressed between the two expandable rings, providing full control on both the layers compression pressure and the anastomosis final diameter. The device was evaluated in ex vivo experimental models of swine aortic arch fresh samples; air-tight sealing at increasing endovascular pressures was also evaluated and compared with sealing achieved by standard suturing. Ex vivo data suggest that the present version of the device can be used easily and quickly also in elliptical, asymmetric 'oblique' anastomosis as when concavity arch is involved. Perfect air-tight sealing of the anastomosis was verified at endovascular pressures up to 150 mmHg, while standard suture cannot withstand even minimal endovascular air pressure. Compared to the previous versions, the present device is less bulky and softer, can be used also for concavity arch resection and provides full and standardizable control on dissection layers stable and sealed approximation. PMID:19933306

  12. 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%.

  13. 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.

  14. A new device concept for directly modulating spinal cord pathways: initial in vivo experimental results.

    PubMed

    Flouty, Oliver; Oya, Hiroyuki; Kawasaki, Hiroto; Wilson, Saul; Reddy, Chandan G; Jeffery, Nicholas D; Brennan, Timothy J; Gibson-Corley, Katherine N; Utz, Marcel; Gillies, George T; Howard, Matthew A

    2012-12-01

    We describe a novel spinal cord (SC) stimulator that is designed to overcome a major shortcoming of existing stimulator devices: their restricted capacity to selectively activate targeted axons within the dorsal columns. This device overcomes that limitation by delivering electrical stimuli directly to the pial surface of the SC. Our goal in testing this device was to measure its ability to physiologically activate the SC and examine its capacity to modulate somatosensory evoked potentials (SSEPs) triggered by peripheral stimulation. In this acute study on adult sheep (n = 7), local field potentials were recorded from a grid placed in the subdural space of the right hemisphere during electrical stimulation of the left tibial nerve and the spinal cord. Large amplitude SSEPs (>200 µV) in response to SC stimulation were consistently obtained at stimulation strengths well below the thresholds inducing neural injury. Moreover, stimulation of the dorsal columns with signals employed routinely by devices in standard clinical use, e.g., 50 Hz, 0.2 ms pulse width, produced long-lasting changes (>4.5 h) in the SSEP patterns produced by subsequent tibial nerve stimulation. The results of these acute experiments demonstrate that this device can be safely secured to the SC surface and effectively activate somatosensory pathways. PMID:23151433

  15. 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.

  16. 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.

  17. 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.

  18. 42 CFR 405.209 - Payment for a non-experimental/investigational (Category B) device.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Medical Services Coverage Decisions That Relate to Health Care Technology § 405.209 Payment for a non... used device serving the same medical purpose that has been approved or cleared for marketing by the FDA... serving the same medical purpose that has been approved or cleared for marketing by the FDA....

  19. 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.

  20. 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.

  1. Experiments and modeling of discharge characteristics in water-mist sprays generated by pressure-swirl atomizers

    NASA Astrophysics Data System (ADS)

    Santangelo, Paolo E.

    2012-12-01

    Pressure-swirl atomizers are often employed to generate a water-mist spray, typically employed in fire suppression. In the present study, an experimental characterization of dispersion (velocity and cone angle) and atomization (drop-size axial evolution) was carried out following a previously developed methodology, with specific reference to the initial region of the spray. Laser-based techniques were used to quantitatively evaluate the considered phenomena: velocity field was reconstructed through a Particle Image Velocimetry analysis; drop-size distribution was measured by a Malvern Spraytec device, highlighting secondary atomization and subsequent coalescence along the spray axis. Moreover, a comprehensive set of relations was validated as predictive of the involved parameters, following an inviscid-fluid approach. The proposed model pertains to early studies on pressure-swirl atomizers and primarily yields to determine both initial velocity and cone angle. The spray thickness is also predicted and a classic correlation for Sauter Mean Diameter is shown to provide good agreement with experimental results. The analysis was carried out at the operative pressure of 80 bar; two injectors were employed featuring different orifice diameters and flow numbers, as a sort of parametric approach to this spray typology.

  2. 10 CFR 431.262 - Definitions concerning commercial prerinse spray valves.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... the highest flow mode. Commercial prerinse spray valve means a handheld device designed and marketed... 10 Energy 3 2011-01-01 2011-01-01 false Definitions concerning commercial prerinse spray valves... CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Prerinse Spray Valves § 431.262...

  3. 10 CFR 431.262 - Definitions concerning commercial prerinse spray valves.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... the highest flow mode. Commercial prerinse spray valve means a handheld device designed and marketed... 10 Energy 3 2010-01-01 2010-01-01 false Definitions concerning commercial prerinse spray valves... CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Prerinse Spray Valves § 431.262...

  4. 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.

  5. 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

  6. 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

  7. [Evaluation of the dustiness of a bakery: an integrated system with an experimental electronic device].

    PubMed

    Dario, R; Uva, J; Trani, G; Falco, S; Ancona, V; Petrera, L

    2012-01-01

    In this paper we describe a novel approach to environmental control in a bakery, based on an integration system of qualitative and quantitative information. The aim is to identify prevention policy for allergic disease. Specifically, the dust concentration evaluated continuously by deposimeters and the realization of chemical-analytical investigations on flours samples, used in the production cycle, have given qualitative evaluation on powders dispersion; the integration of an electronic device, characterized by measurement reliability and low cost implementation, supported the development and evaluation of an environmental monitoring system in a bakery. The environmental control system could be used in other work environments where occupational asthma occurred. PMID:23405767

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. Development of an Experimental Drug Eluting Suprachoroidal Microstent as Glaucoma Drainage Device

    PubMed Central

    Hovakimyan, Marina; Siewert, Stefan; Schmidt, Wolfram; Sternberg, Katrin; Reske, Thomas; Stachs, Oliver; Guthoff, Rudolf; Wree, Andreas; Witt, Martin; Schmitz, Klaus-Peter; Allemann, Reto

    2015-01-01

    Purpose: A novel glaucoma drainage device (GDD) with local drug delivery (LDD) system was created and characterized for safety and effectiveness after implantation into the suprachoroidal space (SCS) of rabbit eyes. Methods: Thin films of two different polymers, Poly(3-hydroxybutyrate) (P(3HB)) and Poly(4-hydroxybutyrate) (P(4HB)), containing the drugs mitomycin C (MitC) or paclitaxel (PTX) were attached to silicone-tubes to create LDD devices. The release kinetics of these drugs were explored in vitro using high performance liquid chromatography (HPLC).  Twenty-four New Zealand white rabbits, randomly divided into eight groups, were implanted with different kinds of microstents into SCS. The intraocular pressure (IOP) was monitored noninvasively. After 6 weeks, rabbits were sacrificed and enucleated eyes were used for anterior segment optical coherence tomography (OCT), micro magnetic resonance imaging (MRI), and histology. Results: In vitro, faster drug release from both polymers was observed for MitC compared to PTX. Comparing polymers, the release from P(3HB) matrix was slower for both drugs. MRI and OCT showed all implants maintained a proper location. An effective IOP reduction was observed for up to 6 weeks in eyes with microstents combined with a drug-releasing LDD system. Overall, the surrounding tissue revealed mild-to-moderate inflammation. No pronounced fibrosis was observed in any of the groups. However, both drugs caused damage to the neighboring retina. Conclusions: The suprachoroidal microstent reduced IOP with mild inflammation in rabbit eyes. To avoid negative effects on the retina, it is necessary to identify novel drugs with less cytotoxicity. Future studies are needed to explore the fibrotic process over the long-term. Translational Relevance: The presented data serve as a proof of principle study for the concept of a suprachoroidal drug eluting microstent. Future device improvements will be focused on the design of LDD systems and the use of

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Experimental investigation of aerodynamic devices for wind turbine rotational speed control, phase 1

    NASA Astrophysics Data System (ADS)

    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 suited 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.

  18. Micro device design and fabrication for the experimental investigation of jet impingement on an array of micro pin fins

    NASA Astrophysics Data System (ADS)

    Ndao, Sidy; Peles, Yoav; Jensen, Michael K.

    2014-10-01

    This work presents the design, fabrication, and demonstration of micro devices for the experimental investigation of heat transfer characteristics of jets impinging on an array of micro pin fins for high heat flux microelectronics and photonics cooling applications. The micro devices, fabricated using MEMS fabrication techniques, consist of an array of radially spaced micro pin fins with diameters ranging from 50 µm-125 µm, height of 230 µm, pitch of 250 µm, and a base area of 2  ×  2 mm2. The micro pin fins are of different geometries, namely circular, elliptical, hydrofoil, square, and rectangular. Single-phase and boiling heat transfer experiments were carried out using refrigerant R134a. Enhancement of both the single-phase and the two-phase heat transfer coefficients were observed. Due to the presence of the micro pin fins, the boiling heat transfer was characterized by the suppression of boiling hysteresis. With a better heater design, the proposed micro device is an excellent platform for studying jet impingement heat transfer on micro pin fins.

  19. Clinical and experimental studies of intraoperative autotransfusion using a new filtration device.

    PubMed

    Varga, Z A; Thompson, J F; Locke-Edmunds, J C; Baird, R N; Farndon, J R

    1995-06-01

    The Haemocell S-350 device has recently been introduced for intraoperative autotransfusion. The system uses a novel membrane filter to process shed blood. In the first part of this study a 0.2-micron pore size filter was used in a randomized trial comparing the use of autotransfusion (n = 8) with bank blood controls (n = 9) during aortic reconstruction. This part of the trial was abandoned because of unexpected non-surgical bleeding. Bank blood requirements fell from a median of 3.0 (range 0.0-9.0) units to 1.5 (range 0.0-7.0) units when autotransfusion was used, but these patients had a greater perioperative blood loss (1791 (range 932-3104) versus 1140 (range 440-3840) ml). There was evidence of postoperative heparin excess with an activated partial thromboplastin time ratio of 1.3 (range 0.9-3.0) versus 1.0 (range 1.0-1.2) in controls and an activated clotting time of 206 (range 143-280) versus 137 (range 107-142) s. This was confirmed by raised plasma heparin levels and a prolonged thrombin time normalized by protamine. To improve performance a 0.6-micron pore size filter was studied in ten patients. Filtration efficiency doubled from 19 to 38 per cent. Electron micrographs demonstrated better filter clearance, but 44 per cent of the original concentration of heparin remained in the reinfusate. The S-350 device may be an attractive alternative to centrifugation for intraoperative autotransfusion but, until efficiency is improved, it should only be used for cardiovascular surgery when excess heparin can be reversed with protamine. PMID:7627507

  20. 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.

  1. Testing devices or experimental systems? Cancer clinical trials take the genomic turn.

    PubMed

    Nelson, Nicole C; Keating, Peter; Cambrosio, Alberto; Aguilar-Mahecha, Adriana; Basik, Mark

    2014-06-01

    Clinical trials are often described as machine-like systems for generating specific information concerning drug safety and efficacy, and are understood as a component of the industrial drug development processes. This paper argues that contemporary clinical trials in oncology are not reducible to mere drug testing. Drawing on ethnographic fieldwork and interviews with researchers in the field of oncology from 2010 to 2013, we introduce a conceptual contrast between trials as testing machines and trials as clinical experimental systems to draw attention to the ways trials are increasingly being used to ask open-ended scientific questions. When viewed as testing machines, clinical trials are seen as a means to produce answers to straightforward questions and deviations from the protocol are seen as bugs in the system; but practitioners can also treat trials as clinical experimental systems to investigate as yet undefined problems and where heterogeneity becomes a means to produce novel biological or clinical insights. The rise of "biomarker-driven" clinical trials in oncology, which link measurable biological characteristics such as genetic mutations to clinical features such as a patient's response to a particular drug, exemplifies a trend towards more experimental styles of clinical work. These transformations are congruent with changes in the institutional structure of clinical research in oncology, including a movement towards more flexible, networked research arrangements, and towards using individual patients as model systems for asking biological questions. PMID:24768778

  2. Reproduction of continuous flow left ventricular assist device experimental data by means of a hybrid cardiovascular model with baroreflex control.

    PubMed

    Fresiello, Libera; Zieliński, Krzysztof; Jacobs, Steven; Di Molfetta, Arianna; Pałko, Krzysztof Jakub; Bernini, Fabio; Martin, Michael; Claus, Piet; Ferrari, Gianfranco; Trivella, Maria Giovanna; Górczyńska, Krystyna; Darowski, Marek; Meyns, Bart; Kozarski, Maciej

    2014-06-01

    Long-term mechanical circulatory assistance opened new problems in ventricular assist device-patient interaction, especially in relation to autonomic controls. Modeling studies, based on adequate models, could be a feasible approach of investigation. The aim of this work is the exploitation of a hybrid (hydronumerical) cardiovascular simulator to reproduce and analyze in vivo experimental data acquired during a continuous flow left ventricular assistance. The hybrid cardiovascular simulator embeds three submodels: a computational cardiovascular submodel, a computational baroreflex submodel, and a hydronumerical interface submodel. The last one comprises two impedance transformers playing the role of physical interfaces able to provide a hydraulic connection with specific cardiovascular sites (in this article, the left atrium and the ascending/descending aorta). The impedance transformers are used to connect a continuous flow pump for partial left ventricular support (Synergy Micropump, CircuLite, Inc., Saddlebrooke, NJ, USA) to the hybrid cardiovascular simulator. Data collected from five animals in physiological, pathological, and assisted conditions were reproduced using the hybrid cardiovascular simulator. All parameters useful to characterize and tune the hybrid cardiovascular simulator to a specific hemodynamic condition were extracted from experimental data. Results show that the simulator is able to reproduce animal-specific hemodynamic status both in physiological and pathological conditions, to reproduce cardiovascular left ventricular assist device (LVAD) interaction and the progressive unloading of the left ventricle for different pump speeds, and to investigate the effects of the LVAD on baroreflex activity. Results in chronic heart failure conditions show that an increment of LVAD speed from 20 000 to 22 000 rpm provokes a decrement of left ventricular flow of 35% (from 2 to 1.3 L/min). Thanks to its flexibility and modular structure, the

  3. Development of a biaxial compression device for biological samples: preliminary experimental results for a closed cell foam.

    PubMed

    Little, J P; Tevelen, G; Adam, C J; Evans, J H; Pearcy, M J

    2009-07-01

    Biological tissues are subjected to complex loading states in vivo and in order to define constitutive equations that effectively simulate their mechanical behaviour under these loads, it is necessary to obtain data on the tissue's response to multiaxial loading. Single axis and shear testing of biological tissues is often carried out, but biaxial testing is less common. We sought to design and commission a biaxial compression testing device, capable of obtaining repeatable data for biological samples. The apparatus comprised a sealed stainless steel pressure vessel specifically designed such that a state of hydrostatic compression could be created on the test specimen while simultaneously unloading the sample along one axis with an equilibrating tensile pressure. Thus a state of equibiaxial compression was created perpendicular to the long axis of a rectangular sample. For the purpose of calibration and commissioning of the vessel, rectangular samples of closed cell ethylene vinyl acetate (EVA) foam were tested. Each sample was subjected to repeated loading, and nine separate biaxial experiments were carried out to a maximum pressure of 204 kPa (30 psi), with a relaxation time of two hours between them. Calibration testing demonstrated the force applied to the samples had a maximum error of 0.026 N (0.423% of maximum applied force). Under repeated loading, the foam sample demonstrated lower stiffness during the first load cycle. Following this cycle, an increased stiffness, repeatable response was observed with successive loading. While the experimental protocol was developed for EVA foam, preliminary results on this material suggest that this device may be capable of providing test data for biological tissue samples. The load response of the foam was characteristic of closed cell foams, with consolidation during the early loading cycles, then a repeatable load-displacement response upon repeated loading. The repeatability of the test results demonstrated the

  4. 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

  5. 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.

  6. Experimental Studies on Amount of Snowfall by Crystal Growth in an Artificial Snowfall Device

    NASA Astrophysics Data System (ADS)

    Seki, Mitsuo; Umezawa, Kouichi; Abe, Osamu

    A series of experiments was conducted to estimate the amount of snowfall of dendrite-type crystals produced by an artificial snowfall device that uses the rotary ventilation mesh filter method. An expression is proposed in this paper for the amount of the snowfall. The amount of snowfall (Gs) can be expressed as Gs = ηs Vai ΔW , where ΔW is effective water content in the crystal growth, Vai is air mass flow and ηs is snowfall efficiency. The effective water content in the crystal growth (ΔW) is defined as the difference between the specific cloud water content and ice saturation vapor density. The rotary ventilation mesh filter method used in this work had a snowfall efficiency of about 90%. Even for a large amount of cloud water content, we observed only a very few super-cooled cloud droplets on snow crystals. Therefore, we can deduce that the cloud water content should contribute to crystal growth directly. We report here measurements of snowfall as a function of several input parameters and verify the validity of the proposed relationship.

  7. 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.

  8. Numerical and experimental evaluation of a compact sensor antenna for healthcare devices.

    PubMed

    Alomainy, A; Yang Hao; Pasveer, F

    2007-12-01

    The paper presents a compact planar antenna designed for wireless sensors intended for healthcare applications. Antenna performance is investigated with regards to various parameters governing the overall sensor operation. The study illustrates the importance of including full sensor details in determining and analysing the antenna performance. A globally optimized sensor antenna shows an increase in antenna gain by 2.8 dB and 29% higher radiation efficiency in comparison to a conventional printed strip antenna. The wearable sensor performance is demonstrated and effects on antenna radiated power, efficiency and front to back ratio of radiated energy are investigated both numerically and experimentally. Propagation characteristics of the body-worn sensor to on-body and off-body base units are also studied. It is demonstrated that the improved sensor antenna has an increase in transmitted and received power, consequently sensor coverage range is extended by approximately 25%.

  9. Experimental study of plasmon in a grating coupled graphene device with a resonant cavity

    NASA Astrophysics Data System (ADS)

    Yan, Bo; Fang, Jingyue; Qin, Shiqiao; Liu, Yongtao; Zhou, Yingqiu; Li, Renbing; Zhang, Xue-Ao

    2015-11-01

    Plasmon was probed from graphene which was grown by chemical vapor deposition using terahertz time-domain spectroscopy at room temperature. Graphene was laid on a resonant cavity, and metal grating was then deposited on top of them. For the THz light polarized along the grid fingers, the optical conductivity of graphene changed from Drude response into strongly Lorentz behavior with a peak formed in the THz-region. These experimental results are highly consistent with the theoretical prediction of a single layer graphene. It confirms that the graphene plasmon frequency can be tuned by the length of grating. Moreover, the extinction in the transmission of single-layer graphene can also be increased beyond 60%.

  10. Numerical and experimental evaluation of a compact sensor antenna for healthcare devices.

    PubMed

    Alomainy, A; Yang Hao; Pasveer, F

    2007-12-01

    The paper presents a compact planar antenna designed for wireless sensors intended for healthcare applications. Antenna performance is investigated with regards to various parameters governing the overall sensor operation. The study illustrates the importance of including full sensor details in determining and analysing the antenna performance. A globally optimized sensor antenna shows an increase in antenna gain by 2.8 dB and 29% higher radiation efficiency in comparison to a conventional printed strip antenna. The wearable sensor performance is demonstrated and effects on antenna radiated power, efficiency and front to back ratio of radiated energy are investigated both numerically and experimentally. Propagation characteristics of the body-worn sensor to on-body and off-body base units are also studied. It is demonstrated that the improved sensor antenna has an increase in transmitted and received power, consequently sensor coverage range is extended by approximately 25%. PMID:23852005

  11. Experimental demonstration of novel end-pumping method for double-clad fiber devices.

    PubMed

    Peterka, Pavel; Kasík, Ivan; Mat Jec, Vlastimil; Kube Ek, Václav; Dvo A Ek, Pavel

    2006-11-15

    We present experimental demonstration of an end-pumping scheme based on splicing the multimode pump and single-mode signal fibers directly to a double-clad fiber with a tailored cross section. The method is used to pump a double-clad, erbium- and ytterbium-doped, fiber ring laser. The efficiency of the end-pumping method is tested by determining the slope efficiencies of the fiber ring laser and the fiber laser in a Fabry-Perot configuration. Comparable slope efficiencies are found when both laser configurations have similar output coupler ratios. The developed pumping scheme and double-clad fiber can find applications in cost-effective power fiber amplifiers and lasers. PMID:17072383

  12. An efficient device to experimentally model compression injury of mammalian spinal cord.

    PubMed

    Ropper, Alexander E; Zeng, Xiang; Anderson, Jamie E; Yu, Dou; Han, InBo; Haragopal, Hariprakash; Teng, Yang D

    2015-09-01

    We report an efficient and effective device to reproducibly model clinically relevant spinal cord injury (SCI) via controlled mechanical compression. In the present study, following skin incision, dorsal laminectomy was performed to expose T10 spinal cord of adult female Sprague-Dawley rats (230-250 g). The vertebral column was suspended and stabilized by Allis clamps at T8 and 12 spinous processes. A metal impounder was then gently loaded onto T10 dura (20, 35 or 50 g × 5 min; n=7/group), resulting in acute mild, moderate, or severe standing weight compression, respectively. Neurobehavioral outcomes were evaluated using the BBB locomotor scale and inclined plane test for coordinated hindlimb function, and a battery of spinal reflex tests for sensorimotor functions, at 1 day following SCI and weekly thereafter for 7 weeks. Quantitative histopathology was used to assess injury-triggered loss of white matter, gray matter and ventral horn motor neurons. Immunocytochemical levels of glial fibrillary acidic protein (GFAP) and β-amyloid precursor protein (APP) at the cervical and lumbar regions were measured to determine the distal segment impact of T10 compression. The data demonstrates that the standardized protocol generates weight-dependent hindlimb motosensory deficits and neurodegeneration primarily at and near the lesion epicenter. Importantly, there are significantly increased GFAP and APP expressions in spinal cord segments involved in eliciting post-SCI allodynia. Therefore, the described system reliably produces compression trauma in manners partially emulating clinical quasi-static insults to the spinal cord, providing a pragmatic model to investigate pathophysiological events and potential therapeutics for compression SCI. PMID:26210871

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

    PubMed

    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

  14. 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.

  15. Influence of drop size distribution and fuel vapor fraction on premixed spray combustion

    NASA Astrophysics Data System (ADS)

    Machiroutu, Sridhar Venkatabojji

    Premixed spray combustion is affected by fuel and oxidizer properties, mixture equivalence ratio and spray quality. The spray quality is characterized by a mean droplet diameter (SMD) and a droplet size distribution (DSD). Prior experimental studies have considered only the influence of SMD, in part due to the difficulty in controlling the DSD independently. The present work provides experimental evidence demonstrating the effect of the fuel droplet size distribution and fuel vapor fraction on premixed spray combustion. Combustion experiments were performed in a pilot-ignited, continuous flow, tubular, vertical test rig wherein fuel sprays were injected into an air stream. A novel twin-atomizer technique that allowed control over overall equivalence ratio, SMD, DSD, and fuel vapor fraction of the premixed spray was used to generate test sprays. A line-of-sight, infrared (IR) extinction technique was developed to quantify the fuel vapor fraction in premixed sprays. Radial distributions of fuel vapor were evaluated using an 'onion peeling' deconvolution technique. Combustion of test sprays indicated flame propagation among regions of high fuel vapor fraction to generate a high rate of combustion. In lean premixed sprays, the presence of a low fuel vapor concentration does not impact the combustion process. Experimental evidence demonstrating the enhancement of flame propagation velocity for optimal SMDs of ethanol sprays has been found. It was observed that test sprays with narrower DSDs have faster burning rates and more complete combustion. The DSD of the sprays were characterized with a droplet surface-area-based standard deviation of the DSD.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  17. 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.

  18. 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.

  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. 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.

  1. 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).

  2. 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.

  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. 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

  5. Experimental Evaluation of a Device Prototype Based on Shape Memory Alloys for the Retrofit of Historical Buildings

    NASA Astrophysics Data System (ADS)

    Cardone, Donatello; Sofia, Salvatore

    2012-12-01

    Metallic tie-rods are currently used in many historical buildings for absorbing the out-of-plane horizontal forces of arches, vaults and roof trusses, despite they exhibit several limitations under service and seismic conditions. In this paper, a post-tensioned system based on the superelastic properties of Ni-Ti shape memory alloys is proposed for improving the structural performances of traditional metallic tie-rods. First, the thermal behavior under service conditions is investigated based on the results of numerical and experimental studies. Subsequently, the seismic performances under strong earthquakes are verified trough a number of shaking table tests on a 1:4-scale timber roof truss model. The outcomes of these studies fully confirm the achievement of the design objectives of the proposed prototype device.

  6. Fabrication of single-electron devices using dispersed nanoparticles and fitting experimental results to values calculated based on percolation model

    NASA Astrophysics Data System (ADS)

    Moriya, Masataka; Huong, Tran Thi Thu; Matsumoto, Kazuhiko; Shimada, Hiroshi; Kimura, Yasuo; Hirano-Iwata, Ayumi; Mizugaki, Yoshinao

    2016-08-01

    We calculated the connection probability, P C, between electrodes on the basis of the triangular lattice percolation model for investigating the effect of distance variation between electrodes and the electrode width on fabricated capacitively coupled single-electron transistors. Single-electron devices were fabricated via the dispersion of gold nanoparticles (NPs). The NPs were dispersed via the repeated dropping of an NP solution onto a chip. The experimental results were fitted to the calculated values, and the fitting parameters were compared with the occupation probability, P O, which was estimated for one drop of the NP solution. On the basis of curves of the drain current versus the drain-source voltage ( I D- V DS) measured at 77 K, the current was suppressed at approximately 0 V.

  7. Bilayer lipid membranes: An experimental system for biomolecular electronic devices development

    NASA Astrophysics Data System (ADS)

    Ottova-Leitmannova, A.; Ti Tien, H.

    1992-12-01

    The lipid bilayer postulated as the basic structural matrix of biological membranes is widely accepted. At present, the planar bilayer lipid membrane (BLM) together with spherical lipid bilayers (liposomes), upon suitable modification, serves as a most appropriate model for biological membranes. In recent years, advances in microelectronics and interest in ultrathin organic films, including BLMs and Langmuir-Blodgett (L-B) films, have resulted in a unique fusion of ideas toward the development of biosensors and transducers. Furthermore, recent trends in interdisciplinary studies in chemistry, electronics, and biology have led to a new field of research: biomolecular electronics. This exciting new field of scientific-technological endeavor is part of a more general approach toward the development of a new, post-semiconductor electronic technology, namely, molecular electronics with a long-term goal of molecular computers. Recently, it has been demonstrated that BLMs, after suitable modification, can function as electrodes and exhibit nonlinear electronic properties. These and other experimental findings relevant to sensor development and to “biomolecular electronic devices” (BED) will be described in more details in the present review article. Also the potential use of the BLM system together with its modifications in the development of a new class of organic diodes, switches, biosensors, electrochemical photocells, and biofuel cells will be discussed. Additionally, this paper reports also a novel technique for obtaining BLMs (or lipid bilayers) on solid supports. The presence of solid support on one side of the BLM greatly enhances its mechanical stability, while retaining the dynamic properties of the lipid bilayer. Advantages of the new techniques for self-assembling amphiphilic molecules on rigid substrates are discussed in terms of their possible uses. It is evident that the new BLM system (s-BLMs) is potentially useful for technological applications in the

  8. 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. PMID:25607178

  9. A new device for the measurement of the arterial compliance using implantable sensors. Description and first experimental application.

    PubMed

    Welz, A; Murrmann, G; Hammer, C; Stegner, U

    1993-01-01

    To determine the compliance of experimental arterial grafts and its chronic adaptation after implantation, a new device for measurements was developed which is combined with implantable sensors. The system is based on the physical induction phenomenon. Each sensor comprises two small coils of copper wire which are sutured opposite to each other to the arterial vessel. Up to 3 sensors are adapted to one electrical connector which can be covered subcutaneously. The device is able to read pulsatile diameter excursions of arterial vessels down to 0.02 mm. It was applied first to evaluate the elastic properties of a 4-mm dialdehyde-starch-preserved bovine internal mammary artery implanted in the canine femoral artery position. For comparison an ePTFE graft was used. At implantation the compliance of the biograft was calculated to be 0.028 +/- 0.009% mm Hg-1, which was half of the compliance of the native femoral artery (0.06 +/- 0.0025% mm Hg-1), but superior if compared to the PTFE (0.008 +/- 0.005% mm Hg-1). Within 6 months the compliance of the femoral artery decreased to 0.039 +/- 0.013% mm Hg-1, which was well matched now to the compliance of the biograft (0.027 +/- 0.005% mm Hg-1). PMID:8330642

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  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. 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

  16. The study on the interdependence of spray characteristics and evaporation history of fuel spray in high temperature air crossflow

    NASA Astrophysics Data System (ADS)

    Zhu, J. Y.; Chin, J. S.

    1986-06-01

    A numerical calculation method is used to predict the variation of the characteristics of fuel spray moving in a high temperature air crossflow, mainly, Sauter mean diameter SMD, droplet size distribution index N of Rosin-Rammler distribution and evaporation percentage changing with downstream distance X from the nozzle. The effect of droplet heat-up period evaporation process and forced convection are taken into full account; thus, the calculation model is a very good approximation to the process of spray evaporation in a practical combustor, such as ramjet, aero-gas turbine, liquid propellant rocket, diesel and other liquid fuel-powered combustion devices. The changes of spray characteristics N, SMD and spray evaporation percentage with air velocity, pressure, temperature, fuel injection velocity, and the initial spray parameters are presented.

  17. 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.

  18. Measurement of spray combustion processes

    NASA Technical Reports Server (NTRS)

    Peters, C. E.; Arman, E. F.; Hornkohl, J. O.; Farmer, W. M.

    1984-01-01

    A free jet configuration was chosen for measuring noncombusting spray fields and hydrocarbon-air spray flames in an effort to develop computational models of the dynamic interaction between droplets and the gas phase and to verify and refine numerical models of the entire spray combustion process. The development of a spray combustion facility is described including techniques for laser measurements in spray combustion environments and methods for data acquisition, processing, displaying, and interpretation.

  19. Nicotine Nasal Spray

    MedlinePlus

    ... program, which may include support groups, counseling, or specific behavior change techniques. Nicotine nasal spray is in ... bottles at room temperature and away from excess heat and moisture (not in the bathroom). Discard used ...

  20. Triamcinolone Nasal Spray

    MedlinePlus

    Nasacort® Allergy 24HR ... watery eyes caused by hay fever or other allergies. Triamcinolone nasal spray should not be used to ... the release of certain natural substances that cause allergy symptoms.

  1. Naloxone Nasal Spray

    MedlinePlus

    ... is used along with emergency medical treatment to reverse the life-threatening effects of a known or ... this date passes.Naloxone nasal spray may not reverse the effects of certain opiates such as buprenorphine ( ...

  2. 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 ...

  3. Fentanyl Nasal Spray

    MedlinePlus

    ... older who are taking regularly scheduled doses of another narcotic (opiate) pain medication, and who are tolerant ( ... spray, your doctor may tell you to use another pain medication to relieve that pain, and may ...

  4. 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.

  5. Nasal corticosteroid sprays

    MedlinePlus

    ... Allergic rhinitis symptoms , such as congestion, runny nose, sneezing, itching, or swelling of the nasal passageway Nasal ... Repeat these steps for the other nostril. Avoid sneezing or blowing your nose right after spraying.

  6. Fluticasone Nasal Spray

    MedlinePlus

    ... ingredients in fluticasone nasal spray. Check the package label for a list of the ingredients.tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking, or ...

  7. Oxymetazoline Nasal Spray

    MedlinePlus

    ... hour period. Follow the directions on the package label or on your prescription label carefully, and ask your doctor or pharmacist to ... prescribed by your doctor or directed on the label.If you use oxymetazoline nasal spray for more ...

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. Thermally sprayed coatings

    SciTech Connect

    Diaz, D.J.; Blann, G.A. )

    1991-05-01

    Standardization of specimen preparation for microstructural evaluation of thermally sprayed coatings is considered. Metallographic specimen preparation procedures including sectioning, encapsulation, planar grinding, and power lapping of thermally sprayed coatings are described. A Co-Ni-Cr-W coating on an AISI 410 stainless steel substrate is used as a control sample. Specimen-preparation techniques have been evaluated through scanning electron microscopy for determining the percentage of apparent porosity and energy dispersive spectroscopy for determining elemental composition.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. Analysis of polydisperse fuel spray flame

    NASA Astrophysics Data System (ADS)

    Nave, Ophir; Lehavi, Yaron; Ajadi, Suraju; Gol'dshtein, Vladimir

    2016-06-01

    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 {{Tetralin}} , n-{{Decane}} , and n-{{Heptane}} .

  18. 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.

  19. Spray pattern and droplet size analyses for high-shear viscosity determination of aqueous suspension corticosteroid nasal sprays.

    PubMed

    Pennington, Justin; Pandey, Preetanshu; Tat, Henry; Willson, Jennifer; Donovan, Brent

    2008-09-01

    Aqueous suspension corticosteroid nasal sprays exhibit the rheological property of shear thinning, meaning they exhibit a decrease in viscosity upon application of shear. Most rheological methods are limited in the amount of shear that can be applied to samples (approximately 1,000 s(-1)) and thus can only approximate the viscosities at the high-shear conditions of nasal spray devices (approximately 10(5)-10(6) s(-1)). In the current work, spray area and droplet size were shown to demonstrate viscosity dependence. Three Newtonian fluids were used to determine equations to approximate viscosity at the spray nozzle from correlations to spray area and droplet size using a standard 100 microL Pfeiffer nasal spray pump. Several shear-thinning solutions, including four commercial aqueous suspension corticosteroid nasal sprays and three aqueous Avicel (1, 2, and 3%, wt/wt) samples, were analyzed to demonstrate the ability of spray area and droplet size analysis to estimate high-shear viscosities. The calculated viscosity values trend in accordance with the rheometer data along with the ability to distinguish differences between all samples analyzed.

  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. 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.

  2. 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. PMID:25278646

  3. Engineering a new class of thermal spray nano-based microstructures from agglomerated nanostructured particles, suspensions and solutions: an invited review

    NASA Astrophysics Data System (ADS)

    Fauchais, P.; Montavon, G.; Lima, R. S.; Marple, B. R.

    2011-03-01

    diagnostic tools and strategies, and experimental advances that have enabled the development of a wide range of coating structures exhibiting in numerous cases unique properties. Several examples are detailed. In this paper the following aspects are presented successively (i) the two spray techniques used for manufacturing such coatings: thermal plasma and HVOF, (ii) sensors developed for in-flight diagnostics of micrometre-sized particles and the interaction of a liquid and hot gas flow, (iii) three spray processes: conventional spraying using micrometre-sized agglomerates of nanometre-sized particles, suspension spraying and solution spraying and (iv) the emerging issues resulting from the specific structures of these materials, particularly the characterization of these coatings and (v) the potential industrial applications. Further advances require the scientific and industrial communities to undertake new research and development activities to address, understand and control the complex mechanisms occurring, in particular, thermal flow—liquid drops or stream interactions when considering suspension and liquid precursor thermal spray techniques. Work is still needed to develop new measurement devices to diagnose in-flight droplets or particles below 2 µm average diameter and to validate that the assumptions made for liquid-hot gas interactions. Efforts are also required to further develop some of the characterization protocols suitable to address the specificities of such nanostructured coatings, as some existing 'conventional' protocols usually implemented on thermal spray coatings are not suitable anymore, in particular to address the void network architectures from which numerous coatings properties are derived.

  4. 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.

  5. Numerical studies of dilute and dense spray characteristics

    NASA Technical Reports Server (NTRS)

    Kim, Y. M.; Shang, H. M.; Chen, C. P.; Ziebarth, J. P.; Wang, T. S.

    1992-01-01

    Several issues involving the improvement of physical submodels and the computational efficiency in modeling dilute and dense spray combustion are discussed. First, the implementations of a dispersion width approach accounting for turbulent dispersion within each computational parcel is discussed. This is essentially a statistical transport model and the testings of this model confirm the capability of accurately representing dispersion in nearly-homogeneous and inhomogeneous turbulent flows with improved efficiency over the delta function stochastic separated flow model. To account for the dense spray effects, an existing drop collision and coalescence model and a Taylor analogy breakup (TAB) model were employed. These models were incorporated into a state-of-the-art multiphase all-speed transient flow solution procedure. Several examples including nonevaporating, evaporating, and burning dense spray cases were studied. The numerical results show reasonably good comparisons with available experimental data in terms of spray penetration, drop sizes, and overall configuration of a spray flame.

  6. 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.

  7. 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.

  8. 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.

  9. Effect of orifice diameter on characteristics of hollow cone swirl spray emanating from simplex nozzles

    NASA Astrophysics Data System (ADS)

    Hussein, A.; Hafiz, M.; Helmi, R.; Wisnoe, W.; Jasmi, M.

    2012-06-01

    The paper reports on experimental work to investigate the swirl spray characteristics that emanates from simplex atomizers. Main objective of the research is to investigate the effect of orifice diameter on the spray cone angle, spray breakup length and discharge coefficient at different injection pressure. Discharge coefficient is almost uninfluenced by the operating Reynolds number. This test also reveals that both breakup length and spray cone angle increases as orifice diameter is increased. Higher injection pressure leads to shorter breakup length and wider spray cone angle.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. Quo vadis thermal spraying?

    NASA Astrophysics Data System (ADS)

    Fauchais, P.; Vardelle, A.; Dussoubs, B.

    2001-03-01

    This paper is devoted to thermal spraying and presents the state of our current knowledge, as well as the following research or development needs: spraying heat sources, i.e., flame, high-velocity oxifuel flame (HVOF), detonation gun (D-Gun), and plasma torches; particle heat and momentum transfer (measurements and modeling), process on-line control, powder morphologies, and injection within the hot jet and reactions with environment; coating formation, i.e., particle flattening and solidification, splat layering, residual stresses, coating microstructure, and properties; and reliability and reproducibility of coatings.

  15. 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.

  16. 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.

  17. 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

  18. 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. PMID:25570404

  19. 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…

  20. Zolmitriptan Nasal Spray

    MedlinePlus

    ... diarrhea and stomach pain caused by decreased blood flow to the intestines). Your doctor may tell you not to use zolmitriptan nasal spray.tell your doctor if you smoke or are overweight; if you have or have ever had high blood pressure, high cholesterol, diabetes, or liver or ...

  1. Sumatriptan Nasal Spray

    MedlinePlus

    ... diarrhea and stomach pain caused by decreased blood flow to the intestines). Your doctor may tell you not to use sumatriptan nasal spray.tell your doctor if you smoke or are overweight; if you have or have ever had high blood pressure, high cholesterol, diabetes, seizures, or liver ...

  2. 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.

  3. 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.

  4. Simulation of a turbulent spray flame using coupled PDF gas phase and spray flamelet modeling

    SciTech Connect

    Ge, Hai-Wen; Gutheil, Eva

    2008-04-15

    A joint mixture fraction-enthalpy probability density function (PDF) is proposed for the simulation of turbulent spray flames. The PDF transport equation is deduced and modeled. The interaction-by-exchange-with-the-mean (IEM) model that has been developed for gas-phase flows is extended to describe molecular mixing in nonreactive and reactive spray flows. The joint PDF transport equation is solved by a hybrid finite-volume and Lagrangian Monte Carlo method. Standard spray and turbulence models are used to describe the gas phase and the liquid phase. A turbulent methanol/air spray flame is simulated using the present method. Detailed chemistry is implemented through the spray flamelet model. The precalculated spray flamelet library for methanol/air combustion comprises 23 species and 168 elementary reactions. Thus, the model is capable of predicting the formation of radicals and of pollutants. Different values for the model constant C{sub {phi}} in the IEM model are tested. The numerical results for the gas velocity, the gas temperature, and the mass fraction of methanol vapor are compared with experimental data in the literature. Good agreement with experiment is obtained when C{sub {phi}}=2.0. Marginal PDFs of mixture fraction, enthalpy, and gas temperature are presented. The computed PDFs of mixture fraction are compared with the presumed standard {beta} function and modified {beta} function. The results show that the standard {beta} function fails to reproduce bimodal shapes observed in transported PDF computation, while the modified {beta} function, fits the computed PDFs very well. Moreover, joint PDFs of mixture fraction and enthalpy are presented and analyzed. The enthalpy and mixture fraction are strongly correlated. The samples that deviate from the linear correlation are due to the energy consumption of local spray evaporation. (author)

  5. Evaporation and combustion of sprays

    NASA Technical Reports Server (NTRS)

    Faeth, G. M.

    1983-01-01

    A description is provided of recent spray evaporation and combustion models, taking into account turbulent two- and three-dimensional spray processes found in furnaces, gas turbine combustors, and internal combustion engines. Within the class of spray models of interest, two major categories are distinguished, including locally homogeneous flow (LHF) models and separated flow (SF) models. SF models are of the greatest practical importance, but LHF models have distinct advantages in some cases. Attention is also given to recent progress on modeling interactions between drops and the flow in both dilute and dense sprays, involving sprays having low and high liquid volume fractions, respectively.

  6. Evaluation of spray application of postmilking teat sanitizer.

    PubMed

    Pankey, J W; Watts, J L

    1983-02-01

    Application of postmilking teat sanitizer by spraying was evaluated in two experimental challenge trials with Streptococcus agalactiae (ATCC 27956) (McDonald 44). A .5% quaternary ammonium teat sanitizer was used in both studies. By direct comparison, teat spraying and dipping did not differ in effectiveness. Efficacy for the .5% quaternary ammonium compound was 58.6%, similar to results on the product applied as a dip (13). PMID:6339578

  7. 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.

  8. Heat transfer in plasma spraying

    NASA Astrophysics Data System (ADS)

    Hijikata, Kunio; Mitui, Kenzi

    A Bi2Te3 film was directly coated by a plasma spraying and its heat transfer process was experimentally investigated. A new thermal probe for measuring the temperature field was developed and its accuracy was checked from a structure of coated film. The Seebeck coefficients of Bi2Te3 films made under different ambient conditions were compared, and it was determined that the cooling condition during film deposition had a great effect on the thermoelectric performance of the film, especially of Bi2Te3 films. It was also shown that a thick thermoelectric film is able to be directly coated on the heat transfer pipe, which may bring about a large improvement in the conversion efficiency caused by the contact resistance between the thermoelectric elements and a heat source.

  9. 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.

  10. 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.

  11. Modeling of spray droplets deformation and breakup

    NASA Technical Reports Server (NTRS)

    Ibrahim, E. A.; Yang, H. Q.; Przekwas, A. J.

    1993-01-01

    A droplet deformation and breakup (DDB) model is proposed to study shear-type mechanism of spray droplets in pure extentional flows. A numerical solution of the DDB model equation is obtained using a fourth-order Runge-Kutta initial-value solver. The predictions of the DDB model as well as semianalytical and the Taylor analogy models are compared with the experimental data (Krzeczkowski, 1980) for shear breakup, which depict the dimensionless deformation of the drop vs dimensionless time.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Pharmaceutical spray freeze drying.

    PubMed

    Wanning, Stefan; Süverkrüp, Richard; Lamprecht, Alf

    2015-07-01

    Pharmaceutical spray-freeze drying (SFD) includes a heterogeneous set of technologies with primary applications in apparent solubility enhancement, pulmonary drug delivery, intradermal ballistic administration and delivery of vaccines to the nasal mucosa. The methods comprise of three steps: droplet generation, freezing and sublimation drying, which can be matched to the requirements given by the dosage form and route of administration. The objectives, various methods and physicochemical and pharmacological outcomes have been reviewed with a scope including related fields of science and technology.

  17. [Experimental microbiological research on instrument and denture disinfection with a disinfectant spray for dental practice and the use of patients. 1. The formulation of the problem and bacteriological studies].

    PubMed

    Oehring, H; Welker, D; Musil, R; Gruhn, I; Otto, U; Sprenger, R

    1990-01-01

    Three disinfectant sprays (Arugeen, Desident and Fesia-sept) proved to be very efficient against pure cultures of aero bacteria species, Cand. albicans, saliva flora and entero- and influenza viruses. The methods included carrier experiments using denture basis resins, fragments of orthodontic appliances and screws (instead of instruments).

  18. 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...

  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. Experimental ATR device for real-time FTIR imaging of living cells using brilliant synchrotron radiation sources.

    PubMed

    Mariangela, Cestelli-Guidi; Seydou, Yao; Diego, Sali; Sabine, Castano; Augusto, Marcelli; Petibois, Cyril

    2013-01-01

    In this contribution we present the design of an original Attenuated Total Reflection (ATR)-based device designed for an IR microscope coupled to a FPA detector and optimized for in-vivo cell imaging. The optical element has been designed to perform real time experiments of cell biochemical processes. The device includes a manually removable Ge-crystal that guarantees an ease manipulation during the cell culture and a large flat surface to support the cell growth and the required change of the culture wells. This layout will allow performing sequential ATR IR imaging with the crystal immersed in the culture wells, minimizing contributions due to water vapors in the optical system. Using existing brilliant synchrotron radiation sources this ATR device may collect images at the surface of the Ge crystal at a sub-cellular spatial resolution with a penetration depth of the evanescent wave inside the sample of ~500 nm within few seconds. A brief summary of the cellular components that should be detected with such optical device is also presented.

  1. 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.

  2. 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.

  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. Carbon dioxide jet spray cleaning: mechanisms and risks

    NASA Astrophysics Data System (ADS)

    Hills, Malina M.

    1994-10-01

    Carbon dioxide (CO2) gas/solid jet sprays have been proposed for replacing ozone depleting cleaning solvents and for on-orbit cleaning of satellite-borne sensors. We have performed experiments to ascertain the mechanisms of molecular contaminant film removal with commercial CO2 gas/solid jet spray devices. Infrared measurements of germanium plates coated with various contaminant films were made before, during, and after cleaning with a CO2 jet spray. The inferred cleaning times and overall cleaning efficiencies combined with the known solubilities of the contaminants in liquid CO2 suggest that multiple cleaning mechanisms occur: physical removal of the film and solvation of the contaminant into the CO2 particle. These mechanisms explain the selectivity in cleaning efficiencies of the CO2 jet spray for different contaminants. We have also measured the electrostatic charging induced by the jet spray on ungrounded substrates, which in some cases, charge up to several kilowatts. The charging results from the difference in work functions of the CO2 and substrate. The work function is an intrinsic material property, therefore, the extent of charging can be reduced, but not eliminated. Environmental factors that affect the charging and the resultant limitations placed on the use of this device are discussed.

  5. 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.

  6. 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.

  7. Impact of nanocrystal spray deposition on inorganic solar cells.

    PubMed

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

    2014-05-28

    Solution-synthesized inorganic cadmium telluride nanocrystals (∼4 nm; 1.45 eV band gap) are attractive elements for the fabrication of thin-film-based low-cost photovoltaic (PV) devices. Their encapsulating organic ligand shell enables them to be easily dissolved in organic solvents, and the resulting solutions can be spray-cast onto indium-tin oxide (ITO)-coated glass under ambient conditions to produce photoactive thin films of CdTe. Following annealing at 380 °C in the presence of CdCl2(s) and evaporation of metal electrode contacts (glass/ITO/CdTe/Ca/Al), Schottky-junction PV devices were tested under simulated 1 sun conditions. An improved PV performance was found to be directly tied to control over the film morphology obtained by the adjustment of spray parameters such as the solution concentration, delivery pressure, substrate distance, and surface temperature. Higher spray pressures produced thinner layers (<60 nm) with lower surface roughness (<200 nm), leading to devices with improved open-circuit voltages (Voc) due to decreased surface roughness and higher short-circuit current (Jsc) as a result of enhanced annealing conditions. After process optimization, spray-cast Schottky devices rivaled those prepared by conventional spin-coating, showing Jsc = 14.6 ± 2.7 mA cm(-2), Voc = 428 ± 11 mV, FF = 42.8 ± 1.4%, and Eff. = 2.7 ± 0.5% under 1 sun illumination. This optimized condition of CdTe spray deposition was then applied to heterojunction devices (ITO/CdTe/ZnO/Al) to reach 3.0% efficiency after light soaking under forward bias. The film thickness, surface morphology, and light absorption were examined with scanning electron microscopy, optical profilometry, and UV/vis spectroscopy. PMID:24755091

  8. 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

  9. 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. PMID:22907957

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Influence of Spraying Parameters on the Microstructure and Properties of Plasma-sprayed Al2O3/40%TiO2 Coating

    NASA Astrophysics Data System (ADS)

    Kang, J. J.; Xu, B. S.; Wang, H. D.; Wang, C. B.

    In this paper, the influences of parameters such as spraying voltage, spraying current, primary gas feed rate and spraying distance on the properties of plasma-sprayed Al2O3-40 wt.%TiO2 composite ceramic coating were studied by using orthogonal experimental design. The influence sequences of the parameters on the properties of plasma-sprayed Al2O3-40 wt.%TiO2 coating are: spraying distance, spraying voltage, spraying current, argon gas flow rate. The optimum parameters were determined: spraying distance 100 mm, spraying current 440 A, spraying voltage 120 V, and argon gas flow rate 3.0 m3/h. Scanning electronic microscope was used to observe the surface and cross-section morphologies of the Al2O3-40 wt.%TiO2 coating prepared by using the optimum parameters. The phase structure was analyzed by X ray diffraction. The through-thickness microhardness was measured by microhardness instrument. The bonding strength between the coating and substrate was determined by dual tensile test method. The porosity was measured by image analysis method. The results showed that the plasma-sprayed Al2O3-40 wt.%TiO2 composite ceramic coating has a dense structure with the porosity of 1.5%. In addition, the coating has typical layered structure. Al2O3-rich area and TiO2-rich area exhibiting different colors have homogeneous distribution and good combination. Due to the function of NiAl/AlSi bond coating, the bonding strength between the Al2O3- 40 wt.% TiO2 coating and substrate reaches 45 MPa. The coating is mainly composed of γ-Al2O3 metastable phase, α-Al2O3 stable phase, Ti8O15 and Al2TiO5.

  15. Sequential cryogen spraying for heat flux control at the skin surface

    NASA Astrophysics Data System (ADS)

    Majaron, Boris; Aguilar, Guillermo; Basinger, Brooke; Randeberg, Lise L.; Svaasand, Lars O.; Lavernia, Enrique J.; Nelson, J. Stuart

    2001-05-01

    Heat transfer rate at the skin-air interface is of critical importance for the benefits of cryogen spray cooling in combination with laser therapy of shallow subsurface skin lesions, such as port-wine stain birthmarks. With some cryogen spray devices, a layer of liquid cryogen builds up on the skin surface during the spurt, which may impair heat transfer across the skin surface due to relatively low thermal conductivity and potentially higher temperature of the liquid cryogen layer as compared to the spray droplets. While the mass flux of cryogen delivery can be adjusted by varying the atomizing nozzle geometry, this may strongly affect other spray properties, such as lateral spread (cone), droplet size, velocity, and temperature distribution. We present here first experiments with sequential cryogen spraying, which may enable accurate mass flux control through variation of spray duty cycle, while minimally affecting other spray characteristics. The observed increase of cooling rate and efficiency at moderate duty cycle levels supports the above described hypothesis of isolating liquid layer, and demonstrates a novel approach to optimization of cryogen spray devices for individual laser dermatological applications.

  16. 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.

  17. 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.

  18. Studies on fuel spray characteristics in high-pressure environment

    NASA Technical Reports Server (NTRS)

    Shang, H. M.; Kim, Y. M.; Chen, C. P.; Wang, T. S.

    1992-01-01

    The present study deals with several issues involving the improvement of physical submodels and the computational efficiency in modeling dense fuel sprays. To improve the computational efficiency, a parcel PDF approach is implemented which can account for turbulent dispersion within each computational parcel. The advantage of a parcel PDF tracking method is to reduce the number of computational parcels representing the spray dynamics as well as to obtain grid-independent solutions for two-phase flows. To account for the dense spray effects, an existing drop collision and coalescence model, two breakup models, and a Reitz's wave instability model were used. These models were incorporated into a state-of-the-art multiphase all-speed transient flow solution procedure. Comparative performance for two breakup models as well as the turbulence modulation effects are also studied. Validation cases include the nonevaporating and evaporating solid-cone dense sprays. The predictions show a reasonably good agreement with available experimental results in terms of spray penetration, drop sizes, gas and drop mean velocities, and gas and drop rms velocities. The numerical results indicate that the present parcel PDF model has the capability of accurately representing drop dispersion in dense sprays with manageable number of computational parcels.

  19. Studies on fuel spray characteristics in high-pressure environment

    NASA Astrophysics Data System (ADS)

    Shang, H. M.; Kim, Y. M.; Chen, C. P.; Wang, T. S.

    1992-07-01

    The present study deals with several issues involving the improvement of physical submodels and the computational efficiency in modeling dense fuel sprays. To improve the computational efficiency, a parcel PDF approach is implemented which can account for turbulent dispersion within each computational parcel. The advantage of a parcel PDF tracking method is to reduce the number of computational parcels representing the spray dynamics as well as to obtain grid-independent solutions for two-phase flows. To account for the dense spray effects, an existing drop collision and coalescence model, two breakup models, and a Reitz's wave instability model were used. These models were incorporated into a state-of-the-art multiphase all-speed transient flow solution procedure. Comparative performance for two breakup models as well as the turbulence modulation effects are also studied. Validation cases include the nonevaporating and evaporating solid-cone dense sprays. The predictions show a reasonably good agreement with available experimental results in terms of spray penetration, drop sizes, gas and drop mean velocities, and gas and drop rms velocities. The numerical results indicate that the present parcel PDF model has the capability of accurately representing drop dispersion in dense sprays with manageable number of computational parcels.

  20. 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…

  1. 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.

  2. 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.

  3. 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.

  4. An overview of Experimental Condensed Matter Physics in Argentina by 2014, and Oxides for Non Volatile Memory Devices: The MeMOSat Project

    NASA Astrophysics Data System (ADS)

    Levy, Pablo

    2015-03-01

    In the first part of my talk, I will describe the status of the experimental research in Condensed Matter Physics in Argentina, biased towards developments related to micro and nanotechnology. In the second part, I will describe the MeMOSat Project, a consortium aimed at producing non-volatile memory devices to work in aggressive environments, like those found in the aerospace and nuclear industries. Our devices rely on the Resistive Switching mechanism, which produces a permanent but reversible change in the electrical resistance across a metal-insulator-metal structure by means of a pulsed protocol of electrical stimuli. Our project is devoted to the study of Memory Mechanisms in Oxides (MeMO) in order to establish a technological platform that tests the Resistive RAM (ReRAM) technology for aerospace applications. A review of MeMOSat's activities is presented, covering the initial Proof of Concept in ceramic millimeter sized samples; the study of different oxide-metal couples including (LaPr)2/3Ca1/3MnO, La2/3Ca1/3MnO3, YBa2Cu3O7, TiO2, HfO2, MgO and CuO; and recent miniaturized arrays of micrometer sized devices controlled by in-house designed electronics, which were launched with the BugSat01 satellite in June2014 by the argentinian company Satellogic.

  5. 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.

  6. Nicotine nasal spray and vapor inhaler: abuse liability assessment.

    PubMed

    Schuh, K J; Schuh, L M; Henningfield, J E; Stitzer, M L

    1997-04-01

    Acute subjective and physiological effects were examined to provide information relevant to abuse liability of new nicotine delivery systems. Subjects (n = 12) were overnight-deprived smokers who received 0, 4, 8 and 16 active puffs from nicotine-containing cigarettes (0.1 mg per puff), 0, 1, 2 or 4 nasal sprays (0.5 mg nicotine per spray) and 0, 30, 60 and 120 vapor inhalations (estimated 0.013 mg nicotine per inhalation) in a within-subject single blinded design. While smokers clearly liked cigarette puffs, there was much less evidence of liking produced by either nasal spray or vapor inhaler; only modest elevations on a measure of good drug effects were observed. The novel delivery products engendered unpleasant effects of burning throat and nose, watery eyes, runny nose, coughing and sneezing that might be expected to limit abuse liability. Nicotine plasma level and heart rate increase was dose-related for cigarettes and nasal spray but not for vapor inhaler, indicating limited nicotine delivery with the latter device. Overall, results are consistent with the conclusion that the nicotine nasal spray and vapor inhaler are of substantially lower abuse liability than cigarettes in experienced cigarette smokers receiving initial exposure to these products. PMID:9160851

  7. Experimental results on the irradiation of nuclear fusion relevant materials at the dense plasma focus ‘Bora’ device

    NASA Astrophysics Data System (ADS)

    Cicuttin, A.; Crespo, M. L.; Gribkov, V. A.; Niemela, J.; Tuniz, C.; Zanolli, C.; Chernyshova, M.; Demina, E. V.; Latyshev, S. V.; Pimenov, V. N.; Talab, A. A.

    2015-06-01

    Samples of materials counted as perspective ones for use in the first-wall and construction elements in nuclear fusion reactors (FRs) with magnetic and inertial plasma confinement (W, Ti, Al, low-activated ferritic steel ‘Eurofer’ and some alloys) were irradiated in the dense plasma focus (DPF) device ‘Bora’ having a bank energy of ⩽5 kJ. The device generates hot dense (T ˜ 1 keV, n ˜ 1019 cm-3) deuterium plasma, powerful plasma streams (v ˜ 3 × 107 cm s-1) and fast (E ˜ 0.1 … 1.0 MeV) deuterons of power flux densities q up to 1010 and 1012 W cm-2 correspondingly. ‘Damage factor’ F = q × τ0.5 ensures an opportunity to simulate radiation loads (predictable for both reactors types) by the plasma/ion streams, which have the same nature and namely those parameters as expected in the FR modules. Before and after irradiation we provided investigations of our samples by means of a number of analytical techniques. Among them we used optical and scanning electron microscopy to understand character and parameters of damageability of the surface layers of the samples. Atomic force microscopy was applied to measure roughness of the surface after irradiation. These characteristics are quite important for understanding mechanisms and values of dust production in FR that may relate to tritium retention and emergency situations in FR facilities. We also applied two new techniques. For the surface we elaborated the portable x-ray diffractometer that combines x-ray single photon detection with high spectroscopic and angular resolutions. For bulk damageability investigations we applied an x-ray microCT system where x-rays were produced by a Hamamatsu microfocus source (150 kV, 500 µA, 5 µm minimum focal spot size). The detector was a Hamamatsu CMOS flat panel coupled to a fibre optic plate under the GOS scintillator. The reconstruction of three-dimensional data was run with Cobra 7.4 and DIGIX CT software while VG Studio Max 2.1, and Amira 5.3 were used for

  8. Development of TRIGA-based experimental device for fiber optics in-core instrumentation testing for VHTRs

    SciTech Connect

    Johns, J. M.; Tsvetkov, P. V.

    2012-07-01

    Given the harsh environments of high temperature reactors, new in-core instrumentation has to be developed, since existing approaches may fail prematurely in VHTRs. The paper discusses ongoing efforts to support progress of suitable advanced in-core instrumentation technologies and develop an experimental approach for evaluation of their performance within VHTRs via emulation of VHTR in-core conditions in TRIGA reactors. Successful completion of the presented computational analysis concludes the first phase of the project. As demonstrated, it is proposed to use a high temperature furnace with fluence equivalency in operating TRIGA reactors. (authors)

  9. AMPS data management requirements study, appendix 1. [user manuals (computer programs)/display devices - computerized simulation/experimentation/ionosphere

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Flow charts and display formats for the simulation of five experiments are given. The experiments are: (1) electromagnetic wave transmission; (2) passive observations of ambient plasma; (3) ionospheric measurements with subsatellite; (4) electron accelerator beam measurements; and (5) measurement of acoustical gravity waves in the sodium layer using lasers. A detailed explanation of the simulation procedure, definition of variables, and an explanation of how the experimenter makes display choices is also presented. A functional description is included on each flow chart and the assumptions and definitions of terms and scope of the flow charts and displays are presented.

  10. 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.

  11. 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.

  12. INEL spray-forming research

    SciTech Connect

    McHugh, K.M.; Key, J.F.

    1992-12-31

    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.

  13. Development of Ag/WO3/ITO thin film memristor using spray pyrolysis method

    NASA Astrophysics Data System (ADS)

    Dongale, T. D.; Mohite, S. V.; Bagade, A. A.; Gaikwad, P. K.; Patil, P. S.; Kamat, R. K.; Rajpure, K. Y.

    2015-11-01

    The unique nonlinear relationship between charge and magnetic flux along with the pinched hysteresis loop in I- V plane provide memory with resistance combinations of attribute to Memristor which lead to their novel applications in non volatile memory, nonlinear dynamics, analog computations and neuromorphic biological systems etc. The present paper reports development of Ag/WO3/ITO thin film memristor device using spray pyrolysis method. The structural, morphological and electrical properties of the thin film memristor device are further characterized using x-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and semiconductor device analyzer. The memristor is simulated using linear dopent drift model to ascertain the theoretical and experimental conformations. For the simulation purpose, the width of doped region (w) limited to the interval [0, D] is considered as a state variable along with the window function characterized by the equation f ( x) = w (1 - w). The reported memristor device exhibits the symmetric pinched hysteresis loop in I- V plane within the low operating voltage (±1 V). [Figure not available: see fulltext.

  14. Electrooptical devices

    NASA Astrophysics Data System (ADS)

    Hurwitz, C. E.

    1980-03-01

    This report covers work carried out with support of the Department of the Air Force during the period 1 October 1979 through 31 March 1980. A part of this support was provided by the Rome Air Development Center. CW operation at temperatures up to 55 C has been achieved for GaInAsP/InP double-heterostructure (DH) lasers emitting at 1.5 micrometers, which were grown without a GaInAsP buffer layer. These devices are of interest for use as sources in fiber-optics communications systems, since the lowest transmission loss reported for fused-silica optical fibers occurs at 1.55 micrometers. Surface passivation techniques developed for InP and GaInAsP avalanche photodiodes have resulted in reductions of dark current as large as four orders of magnitude, to values as low as .0000016 A/sq cm at 0.9 V(b) where V(b) is the breakdown voltage. Devices consisting entirely of InP have been passivated with plasma-deposited Si3N4, and those with a GaInAsP layer but with the p-n junction in InP have been passivated with polyimide. Neither of these techniques successfully reduces dark currents in devices with the p-n junction in the GaInAsP, but a film of photoresist sprayed with SF6 as the propellant has given excellent results. The electrical characteristics in InP ion implanted with Sn, Ge, Si, and C have been investigated. All of these column IV elements yielded n-type conductivity and Sn, Ge, and Si showed high electrical activation; however, implanted C was found to have a net electrical activation of only about 5 percent.

  15. Experimental setup for the coating of chlorosilane based self assembling monolayers to reduce stiction in MEMS devices

    NASA Astrophysics Data System (ADS)

    Steiner, H.; Sachse, M.; Schalko, J.; Hortschitz, W.; Kohl, F.; Jachimowicz, A.

    2011-06-01

    An often reported problem during production and operation of silicon MEMS is stiction. It describes the sticking of movable MEMS parts to surrounding structures. The probability of the occurrence of stiction is linked to the surface energy of the MEMS. Self assembling monolayers can be used to reduce the surface energy and therefore the probability of stiction. These monolayers have to resist high temperatures up to 400°C to be compatible with various micro-production processes, e.g., eutectic bonding. Several groups tried to coat such monolayers with different success and results. One problem is the instability of the coating method due to water contaminations of the coating solution. To circumvent this error source, an experimental setup was designed and built up to minimize the water content of the monolayer solvent and ensures reproducible conditions during the coating process. The required set of liquids is piped through a system of valves and tubes to rinse a trench with a silicon die. To avoid contamination of the liquids with water, the setup is partly placed in a box flushed with nitrogen. With this experimental setup, the surface energy γs of the MEMS structures had been reduced from 18.1 mJ/m2 to 33.1 μJ/m2 and 36.6 μJ/m2 for FDTS and DDMS, respectively.

  16. 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.

  17. Experimental and numerical investigation of the influence of argon used as protection gas in a reentry simulation device

    NASA Astrophysics Data System (ADS)

    Schoenemann, A. T.; Auweter-Kurtz, M.; Habiger, H. A.; Sleziona, P. C.; Stoeckle, T.

    1993-07-01

    Plasma wind tunnels at the Institute for Space Research are used for the development and qualification of heat protection material. The plasma is produced by a magneto-plasmadynamic (MPD) accelerator designed for gas mixtures. The influence of adding Ar to a nitrogen plasma was investigated by means of electrostatic (Langmuir) probes, mass spectrometry, Pitot probes, and heat flux probes. Numerical investigations were carried out with a program developed for the simulation of the high enthalpy flow field of MHD generators. The existing numerical code for solving the chemical reactions within an air plasma was extended by argon/air reactions. A comparison was made for a N2 and a N2/Ar plasma using an experimental data set as a starting value for the numerical simulation of the development of the plasma freestream downstream to a second cross section. The results of the numerical simulation are compared with the data set gained at the downstream cross section.

  18. 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.

  19. 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.

  20. 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%.

  1. 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.

  2. Correlation Between Material Properties of Ferroelectric Thin Films and Design Parameters for Microwave Device Applications: Modeling Examples and Experimental Verification

    NASA Technical Reports Server (NTRS)

    Miranda, Felix A.; VanKeuls, Fred W.; Subramanyam, Guru; Mueller, Carl H.; Romanofsky, Robert R.; Rosado, Gerardo

    2000-01-01

    The application of thin ferroelectric films for frequency and phase agile components is the topic of interest of many research groups worldwide. Consequently, proof-of-concepts (POC) of different tunable microwave components using either (HTS, metal)/ferroelectric thin film/dielectric heterostructures or (thick, thin) film "flip-chip" technology have been reported. Either as ferroelectric thin film characterization tools or from the point of view of circuit implementation approach, both configurations have their respective advantages and limitations. However, we believe that because of the progress made so far using the heterostructure (i.e., multilayer) approach, and due to its intrinsic features such as planar configuration and monolithic integration, a study on the correlation of circuit geometry aspects and ferroelectric material properties could accelerate the insertion of this technology into working systems. In this paper, we will discuss our study performed on circuits based on microstrip lines at frequencies above 10 GHz, where the multilayer configuration offers greater ease of insertion due to circuit's size reduction. Modeled results of relevant circuit parameters such as the characteristic impedance, effective dielectric constant, and attenuation as a function of ferroelectric film's dielectric constant, tans, and thickness, will be presented for SrTiO3 and Ba(x)Sr(1-x)TiO3 ferroelectric films. A comparison between the modeled and experimental data for some of these parameters will be presented.

  3. Experimental Validation of a Novel MRI-Compatible HIFU Device for the Treatment of Superficial Venous Insufficiency

    NASA Astrophysics Data System (ADS)

    Salomir, Rares; Pichardo, Samuel; Petrusca, Lorena; Angel, Yves; Lacoste, François; Chapelon, Jean-Yves

    2007-05-01

    A novel High Intensity Focused Ultrasound (HIFU) probe has been designed for minimally-invasive treatment of valvular dysfunction in the saphenous vein, which is known to be the cause of superficial venous insufficiency (SVI) and varicose veins. Treating SVI with HIFU is possible, since venous tissue undergoes localized partial shrinkage when subjected to high temperature elevation. In a previous study in vitro we demonstrated that diameter shrinkage should be sufficient to restore valvular function, as this is done in the more aggressive approach known as external valvuloplasty. Numerical optimization using fast simulations of pressure field have led to a non-spherically shaped probe design with two HIFU elements that focus ultrasound uniformly over a line of length 7 mm, at a depth of 15 mm from the skin. A MR-compatible prototype of the probe has been constructed and this was characterized 1). by electroacustical mapping of the pressure field in water, and 2). by fast, high resolution MR thermal mapping ex vivo on fresh meat samples. Results were in good agreement with those predicted by an analytical approach and numerical simulations. Available experimental data suggest that a short sonication (less than 10 sec duration) should permit sufficient temperature elevation to obtain vein shrinkage. Further studies will be performed on surgically excised samples of human veins under MR thermal mapping in order to determine the optimal sonication parameters (duration and power level).

  4. 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.

  5. Characteristics of vaporizing cryogenic sprays for rocket combustion modeling

    NASA Astrophysics Data System (ADS)

    Ingebo, Robert D.

    1994-05-01

    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.

  6. Functionally Graded Materials using Plasma Spray with Nano Structured Ceramic

    NASA Astrophysics Data System (ADS)

    Sioh, E. L.; Tok, A. I. Y.

    2013-03-01

    In this paper, nano structured FGM was fabricated using DC plasma spray technique. Nano structured and micro structured powder were used as the feeding powder with steel substrate. The spray parameters was optimized and characterisation of nano-ceramic FGM and micro-ceramic FGM were done using bending test and micro-hardness test. Experimental results have shown that the nano-structured FGM exhibit 20% improvement flexure strength and 10% in hardness. A comparison was made between sintered micro ceramic tile and nano ceramic FGM using simple drop test method.

  7. Nanolayer Batteries and Spray-Assembled Membranes

    NASA Astrophysics Data System (ADS)

    Hammond, Paula

    2010-03-01

    The electrostatic assembly method enables the construction of devices with a high degree of control of ion and electron transport, and the incorporation of inorganic and organic nanomaterials. This capability allows the generation of a broad range of reactive membranes and electrochemical devices through the use of simple aqueous processing conditions, such as salt content and solution pH, that act as tools for the manipulation of ion and electron transport characteristics in the film, as well as the morphology of these unique nano-assemblies. Ultimately, the use of layer-by-layer systems has led to a range of organic and inorganic materials systems that have incorporated metal oxide nanoparticles, carbon nanotubes, and organic and inorganic polymers to yield systems of interest for solar cells, fuel cells, capacitor/battery and electrochemical energy electrode applications. We have recently introduced an automated misting approach to multilayer assembly, spray-LbL, that enables the coating of complex surfaces and porous substrates, and greatly reduces time to assembly for multilayer devices. This approach has enabled the generation of asymmetric reactive membranes, high surface area devices, and rapidly assembled electrodes.

  8. 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.

  9. 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.

  10. Performance reduction in finger amputees when reaching and operating common control devices: a pilot experimental investigation using a simulated finger disability.

    PubMed

    Pennathur, A; Mital, A; Contreras, L R

    2001-12-01

    This paper reports results of an experimental laboratory investigation to determine if finger amputations (most pervasive upper extremity injury in the United States) result in significant work performance deterioration in tasks requiring operation of common control devices found in industrial settings. Ten male student volunteers from the University of Cincinnati participated in this study. The finger disability simulated was of an extreme nature, and was defined as the loss of four fingers in the preferred hand and the thumb in the nonpreferred hand. While being seated, participants activated 5 types of industrial control devices (a rotary dial, a push button, a toggle switch, a castor wheel, and a rocker switch). The controls were assembled on a device attached to a cylindrical pole, such that the control assembly could move up and down the cylindrical pole. The vertical height of control location (15, 20, and 30 in. from the seat reference point) and angle of control location in vertical plane (0 degree, 45 degrees, 90 degrees, and 135 degrees) were varied in the experiment. Participants also had their torso restrained or unrestrained while reaching and activating controls, in addition to the presence or absence of the simulated disability in each participant. Functional reaches and arm reaches from the wall were measured for participants in the sample to determine the distances at which to place the control pole assembly. If a participant was able to reach the control, the time taken to activate and operate the control was recorded. Overall results indicate that participants took significantly longer (p < 0.05) to activate controls in the presence of the simulated disability. Physical restraint did not significantly alter performance provided the participant was able to reach the control. The type of control and the height of location of the control also significantly affected work performance.

  11. A review of prospective Clinical Trials for neurogenic bladder: The place of surgery, experimental techniques and devices

    PubMed Central

    Braschi, Emmanuel; Lavelle, John

    2014-01-01

    Introduction The neurogenic urinary bladder has been known for at least 30 years now and the concepts behind it are continuously evolving, but there is actually not much work that has been done to accumulate solid clinical evidence in this field. We review the surgical and experimental techniques used in the management of this condition. Material and methods To achieve our goal, we performed Internet searches using the same search string: Urinary bladder, neurogenic. In each case, the search was limited to clinical trial, subjects were human and the language was English. After duplicate removal, we obtained a final number of 580 papers. Data was extracted from each paper into a database file and was analyzed separately for adult and pediatric populations. Results A total of 70 full text papers were reviewed and analyzed according to the previously mentioned algorithm. The first prospective, randomized surgical trials were published less than 20 years ago, starting with 1994, and the number of papers published each year since then has remained in the range of 1–3. The oldest prospective clinical trial for this indication dates back to 1975. The total number of patients included in surgical trials is 3453, out of which 59% are males. The papers include a total of 369 children (21.2%), essentially looking at all the techniques that are also used in adults. Conclusions There is still a lot of work to be done in order to obtain a significant level of evidence in the field of surgical procedures used in neurogenic bladder patients. PMID:25247086

  12. 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

  13. The structure of evaporating and combusting sprays: Measurements and predictions

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

    An apparatus was constructed to provide measurements in open sprays with no zones of recirculation, in order to provide well-defined conditions for use in evaluating spray models. Measurements were completed in a gas jet, in order to test experimental methods, and are currently in progress for nonevaporating sprays. A locally homogeneous flow (LHF) model where interphase transport rates are assumed to be infinitely fast; a separated flow (SF) model which allows for finite interphase transport rates but neglects effects of turbulent fluctuations on drop motion; and a stochastic SF model which considers effects of turbulent fluctuations on drop motion were evaluated using existing data on particle-laden jets. The LHF model generally overestimates rates of particle dispersion while the SF model underestimates dispersion rates. The stochastic SF flow yield satisfactory predictions except at high particle mass loadings where effects of turbulence modulation may have caused the model to overestimate turbulence levels.

  14. High-pressure combustion of binary fuel sprays

    NASA Technical Reports Server (NTRS)

    Mikami, Masato; Kono, Michikata; Sato, Jun'ichi; Dietrich, Daniel L.; Williams, Forman A.

    1995-01-01

    The ultimate objective of this study is to obtain fundamental information relevant to combustion processes that occur in fuel sprays of practical interest at high pressures in internal combustion engines. Since practical fuels are multicomponent and derived from petroleum, the present work involves the model alkane mixture of n-heptane and n-hexadecane. Since burning droplets in sprays can interact with each other, the present work involves investigation of the effects of this interaction on flame shapes and droplet burning times. The small droplets in practical combustion chambers are not significantly influenced by buoyancy. Since such small droplets are difficult to study experimentally, the present work takes advantage of microgravity to lessen buoyancy and enable information about droplet interactions to be obtained by studying larger droplets. The results are intended to provide fundamental understanding that can be used in improving descriptions of practical spray combustion.

  15. Influence of cavitation on near nozzle exit spray

    NASA Astrophysics Data System (ADS)

    Mirshahi, M.; Yan, Y.; Nouri, J. M.

    2015-12-01

    The importance of cavitation inside multi-hole injectors for direct injection internal combustion (IC) engineshas been addressed in many previous investigations. Still, the effect of cavitation on jet spray, its stability and liquid breakup and atomisation is not yet fully understood. The current experimental work aims to address some of these issues. It focuses on the initiation and development of cavitation inside a 7× enlarged transparent model of a symmetric 6-hole spark ignition direct injection (SIDI) injector and quantifies the effect of cavitation on near-nozzle spray cone angle and stability utilising high speed Mie scattering visualisation. The regions studied include the full length of the nozzle and its exitjet spray wherethe primary breakup takes place.

  16. Evaluation of a locally homogeneous flow model of spray combustion

    NASA Technical Reports Server (NTRS)

    Mao, C. P.; Szekely, G. A., Jr.; Faeth, G. M.

    1980-01-01

    A model of spray combustion which employs a second-order turbulence model was developed. The assumption of locally homogeneous flow is made, implying infinitely fast transport rates between the phase. Measurements to test the model were completed for a gaseous n-propane flame and an air atomized n-pentane spray flame, burning in stagnant air at atmospheric pressure. Profiles of mean velocity and temperature, as well as velocity fluctuations and Reynolds stress, were measured in the flames. The predictions for the gas flame were in excellent agreement with the measurements. The predictions for the spray were qualitatively correct, but effects of finite rate interphase transport were evident, resulting in a overstimation of the rate development of the flow. Predictions of spray penetration length at high pressures, including supercritical combustion conditions, were also completed for comparison with earlier measurements. Test conditions involved a pressure atomized n-pentane spray, burning in stagnant air at pressures of 3, 5, and 9 MPa. The comparison between predictions and measurements was fair. This is not a very sensitive test of the model, however, and further high pressure experimental and theoretical results are needed before a satisfactory assessment of the locally homogeneous flow approximation can be made.

  17. Crystallization Evolution of Cold-Sprayed Pure Ni Coatings

    NASA Astrophysics Data System (ADS)

    Cavaliere, P.; Perrone, A.; Silvello, A.

    2016-08-01

    Cold spraying is a coating technology on the basis of aerodynamics and high-speed impact dynamics. Spray particles (usually 1-50 μm in diameter) are accelerated to high velocity (typically 300-1200 m/s) by a high-speed gas (preheated air, nitrogen, or helium) flow that is generated through a convergent-divergent de Laval type nozzle. The coating forms through the intensive plastic deformation of particles impacting on the substrate at temperatures well below the melting point of the spray material. In the present paper, the main processing parameters affecting the crystallization behavior of pure Ni cold spray deposits on IN718 alloy are described. Various experimental conditions have been analyzed: gas temperature and pressure, nozzle to substrate distance. In particular, the study deals with those conditions leading to a strong grain refinement, with an acceptable level of the deposits mechanical properties. In precise spray conditions, a shift toward amorphous phases has been observed and studied. A systematic analysis of microstructural evolution, performed through TEM observations, as a function of processing parameters is presented.

  18. Measurement of Spray Drift with a Specifically Designed Lidar System.

    PubMed

    Gregorio, Eduard; Torrent, Xavier; Planas de Martí, Santiago; Solanelles, Francesc; Sanz, Ricardo; Rocadenbosch, Francesc; Masip, Joan; Ribes-Dasi, Manel; Rosell-Polo, Joan R

    2016-01-01

    Field measurements of spray drift are usually carried out by passive collectors and tracers. However, these methods are labour- and time-intensive and only provide point- and time-integrated measurements. Unlike these methods, the light detection and ranging (lidar) technique allows real-time measurements, obtaining information with temporal and spatial resolution. Recently, the authors have developed the first eye-safe lidar system specifically designed for spray drift monitoring. This prototype is based on a 1534 nm erbium-doped glass laser and an 80 mm diameter telescope, has scanning capability, and is easily transportable. This paper presents the results of the first experimental campaign carried out with this instrument. High coefficients of determination (R² > 0.85) were observed by comparing lidar measurements of the spray drift with those obtained by horizontal collectors. Furthermore, the lidar system allowed an assessment of the drift reduction potential (DRP) when comparing low-drift nozzles with standard ones, resulting in a DRP of 57% (preliminary result) for the tested nozzles. The lidar system was also used for monitoring the evolution of the spray flux over the canopy and to generate 2-D images of these plumes. The developed instrument is an advantageous alternative to passive collectors and opens the possibility of new methods for field measurement of spray drift. PMID:27070613

  19. Spray Characterization of Gas-to-Liquid Synthetic Jet Fuels

    NASA Astrophysics Data System (ADS)

    Kannaiyan, Kumaran; Sadr, Reza

    2011-11-01

    In the recent years, development of alternative jet fuels is gaining importance owing to the demand for cleaner combustion. In addition to having energy density that matches those of conventional fuels, alternate jet fuels need to possess vital qualities such as rapid atomization and vaporization, quick re-ignition at high altitude, less emission, and poses ease of handling. The fuel preparatory steps (atomization and vaporization) and mixing in a combustion chamber play a crucial role on the subsequent combustion and emission characteristics. Gas-to-Liquid (GTL) synthetic jet fuel obtained from Fischer-Tropsch synthesis has grabbed the global attention due to its cleaner combustion characteristics as a result of the absence of aromatics and sulphur. As a part of an on-going joint effort between Texas A&M at Qatar (TAMUQ), Rolls-Royce (UK), and German Aerospace Laboratory (DLR), a spray characterization experimental facility is set up at TAMUQ to study the spray characteristics of GTL fuel and highlights the influence of change in fuel composition on the spray characteristics. In this work, spray characteristics such as droplet size, velocity, and distribution of different GTL fuel blends is investigated and compared with the spray characteristics of conventional JetA1 fuel. Supported by Qatar Science and Technology Park, QSTP.

  20. Measurement of Spray Drift with a Specifically Designed Lidar System

    PubMed Central

    Gregorio, Eduard; Torrent, Xavier; Planas de Martí, Santiago; Solanelles, Francesc; Sanz, Ricardo; Rocadenbosch, Francesc; Masip, Joan; Ribes-Dasi, Manel; Rosell-Polo, Joan R.

    2016-01-01

    Field measurements of spray drift are usually carried out by passive collectors and tracers. However, these methods are labour- and time-intensive and only provide point- and time-integrated measurements. Unlike these methods, the light detection and ranging (lidar) technique allows real-time measurements, obtaining information with temporal and spatial resolution. Recently, the authors have developed the first eye-safe lidar system specifically designed for spray drift monitoring. This prototype is based on a 1534 nm erbium-doped glass laser and an 80 mm diameter telescope, has scanning capability, and is easily transportable. This paper presents the results of the first experimental campaign carried out with this instrument. High coefficients of determination (R2 > 0.85) were observed by comparing lidar measurements of the spray drift with those obtained by horizontal collectors. Furthermore, the lidar system allowed an assessment of the drift reduction potential (DRP) when comparing low-drift nozzles with standard ones, resulting in a DRP of 57% (preliminary result) for the tested nozzles. The lidar system was also used for monitoring the evolution of the spray flux over the canopy and to generate 2-D images of these plumes. The developed instrument is an advantageous alternative to passive collectors and opens the possibility of new methods for field measurement of spray drift. PMID:27070613

  1. Structure of confined laminar spray diffusion flames: Numerical investigation

    NASA Technical Reports Server (NTRS)

    Mawid, M. A.; Bulzan, D. L.; Aggarwal, S. K.

    1993-01-01

    The structure of confined laminar spray diffusion flames is investigated numerically by solving the gas-phase conservation equations for mass species, continuity, momentum, and energy and the liquid-phase equations for droplet position, velocity, size, and temperature. A one-step global reaction scheme along with six equilibrium reactions are employed to model the flame chemistry. Monodisperse as well as polydisperse sprays are considered. The numerical results demonstrate that liquid spray flames substantially differ from gaseous flames in their structure, i.e., temperature, concentration, and velocity fields, shape, and dimensions under the same conditions. Spray flames are predicted to be taller and narrower than their counterpart gaseous ones and their shapes are almost cylindrical. This is in agreement with experimental observations. The numerical computations also show that the use of the equilibrium reactions with the one-step reaction scheme decreases the flame temperature compared to the one-step reaction scheme without the equilibrium reactions and more importantly increases the surface area of the flame zone due to a phenomenon termed 'equilibrium broadening.' The spray flames also possess a finite thickness with minimal overlap of the fuel and oxygen species. A case for which a fuel-mixture consisting of 20 to 80 percent gas-liquid by mass is introduced into the combustor is also investigated and compared with predictions using only gaseous or liquid fuel.

  2. Measurement of Spray Drift with a Specifically Designed Lidar System.

    PubMed

    Gregorio, Eduard; Torrent, Xavier; Planas de Martí, Santiago; Solanelles, Francesc; Sanz, Ricardo; Rocadenbosch, Francesc; Masip, Joan; Ribes-Dasi, Manel; Rosell-Polo, Joan R

    2016-04-08

    Field measurements of spray drift are usually carried out by passive collectors and tracers. However, these methods are labour- and time-intensive and only provide point- and time-integrated measurements. Unlike these methods, the light detection and ranging (lidar) technique allows real-time measurements, obtaining information with temporal and spatial resolution. Recently, the authors have developed the first eye-safe lidar system specifically designed for spray drift monitoring. This prototype is based on a 1534 nm erbium-doped glass laser and an 80 mm diameter telescope, has scanning capability, and is easily transportable. This paper presents the results of the first experimental campaign carried out with this instrument. High coefficients of determination (R² > 0.85) were observed by comparing lidar measurements of the spray drift with those obtained by horizontal collectors. Furthermore, the lidar system allowed an assessment of the drift reduction potential (DRP) when comparing low-drift nozzles with standard ones, resulting in a DRP of 57% (preliminary result) for the tested nozzles. The lidar system was also used for monitoring the evolution of the spray flux over the canopy and to generate 2-D images of these plumes. The developed instrument is an advantageous alternative to passive collectors and opens the possibility of new methods for field measurement of spray drift.

  3. Modelling the Plasma Jet in Multi-Arc Plasma Spraying

    NASA Astrophysics Data System (ADS)

    Bobzin, K.; Öte, M.; Schein, J.; Zimmermann, S.; Möhwald, K.; Lummer, C.

    2016-08-01

    Particle in-flight characteristics in atmospheric plasma spraying process are determined by impulse and heat energy transferred between the plasma jet and injected powder particles. One of the important factors for the quality of the plasma-sprayed coatings is thus the distribution of plasma gas temperatures and velocities in plasma jet. Plasma jets generated by conventional single-arc plasma spraying systems and their interaction with powder particles were subject matter of intensive research. However, this does not apply to plasma jets generated by means of multi-arc plasma spraying systems yet. In this study, a numerical model has been developed which is designated to dealing with the flow characteristics of the plasma jet generated by means of a three-cathode spraying system. The upstream flow conditions, which were calculated using a priori conducted plasma generator simulations, have been coupled to the plasma jet simulations. The significances of the relevant numerical assumptions and aspects of the models are analyzed. The focus is placed on to the turbulence and diffusion/demixing modelling. A critical evaluation of the prediction power of the models is conducted by comparing the numerical results to the experimental results determined by means of emission spectroscopic computed tomography. It is evident that the numerical models exhibit a good accuracy for their intended use.

  4. Simulation and Experimental Study on Anti-reflection Characteristics of Nano-patterned Si Structures for Si Quantum Dot-Based Light-Emitting Devices.

    PubMed

    Shao, Wenyi; Lu, Peng; Li, Wei; Xu, Jun; Xu, Ling; Chen, Kunji

    2016-12-01

    Surface-textured structure is currently an interesting topic since it can efficiently reduce the optical losses in advanced optoelectronic devices via light management. In this work, we built a model in finite-difference time-domain (FDTD) solutions by setting the simulation parameters based on the morphology of the Si nanostructures and compared with the experimental results in order to study the anti-reflection behaviors of the present nano-patterned structures. It is found that the reflectance is gradually reduced by increasing the depth of Si nanostructures which is in well agreement with the experimental observations. The reflectance can be lower than 10 % in the light range from 400 to 850 nm for Si nano-patterned structures with a depth of 150 nm despite the quite low aspect ratio, which can be understood as the formation of gradually changed index layer and the scattering effect of Si nano-patterned structures. By depositing the Si quantum dots/SiO2 multilayers on nano-patterned Si substrate, the reflectance can be further suppressed and the luminescence intensity centered at 820 nm from Si quantum dots is enhanced by 6.6-fold compared with that of flat one, which can be attributed to the improved light extraction efficiency. However, the further etch time causes the reduction of luminescence intensity from Si quantum dots which may ascribe to the serious surface recombination of carriers. PMID:27356564

  5. Simulation and Experimental Study on Anti-reflection Characteristics of Nano-patterned Si Structures for Si Quantum Dot-Based Light-Emitting Devices.

    PubMed

    Shao, Wenyi; Lu, Peng; Li, Wei; Xu, Jun; Xu, Ling; Chen, Kunji

    2016-12-01

    Surface-textured structure is currently an interesting topic since it can efficiently reduce the optical losses in advanced optoelectronic devices via light management. In this work, we built a model in finite-difference time-domain (FDTD) solutions by setting the simulation parameters based on the morphology of the Si nanostructures and compared with the experimental results in order to study the anti-reflection behaviors of the present nano-patterned structures. It is found that the reflectance is gradually reduced by increasing the depth of Si nanostructures which is in well agreement with the experimental observations. The reflectance can be lower than 10 % in the light range from 400 to 850 nm for Si nano-patterned structures with a depth of 150 nm despite the quite low aspect ratio, which can be understood as the formation of gradually changed index layer and the scattering effect of Si nano-patterned structures. By depositing the Si quantum dots/SiO2 multilayers on nano-patterned Si substrate, the reflectance can be further suppressed and the luminescence intensity centered at 820 nm from Si quantum dots is enhanced by 6.6-fold compared with that of flat one, which can be attributed to the improved light extraction efficiency. However, the further etch time causes the reduction of luminescence intensity from Si quantum dots which may ascribe to the serious surface recombination of carriers.

  6. Simulation and Experimental Study on Anti-reflection Characteristics of Nano-patterned Si Structures for Si Quantum Dot-Based Light-Emitting Devices

    NASA Astrophysics Data System (ADS)

    Shao, Wenyi; Lu, Peng; Li, Wei; Xu, Jun; Xu, Ling; Chen, Kunji

    2016-06-01

    Surface-textured structure is currently an interesting topic since it can efficiently reduce the optical losses in advanced optoelectronic devices via light management. In this work, we built a model in finite-difference time-domain (FDTD) solutions by setting the simulation parameters based on the morphology of the Si nanostructures and compared with the experimental results in order to study the anti-reflection behaviors of the present nano-patterned structures. It is found that the reflectance is gradually reduced by increasing the depth of Si nanostructures which is in well agreement with the experimental observations. The reflectance can be lower than 10 % in the light range from 400 to 850 nm for Si nano-patterned structures with a depth of 150 nm despite the quite low aspect ratio, which can be understood as the formation of gradually changed index layer and the scattering effect of Si nano-patterned structures. By depositing the Si quantum dots/SiO2 multilayers on nano-patterned Si substrate, the reflectance can be further suppressed and the luminescence intensity centered at 820 nm from Si quantum dots is enhanced by 6.6-fold compared with that of flat one, which can be attributed to the improved light extraction efficiency. However, the further etch time causes the reduction of luminescence intensity from Si quantum dots which may ascribe to the serious surface recombination of carriers.

  7. Characterization of coal-water slurry fuel sprays from diesel engine injectors

    SciTech Connect

    Caton, J.A.; Kihm, K.D.

    1993-06-01

    Experiments were conducted to characterize coal-water slurry fuel sprays from diesel engine injectors. Since the combustion event is a strong function of the fuel spray, full characterization of the spray is a necessity for successful engine design and for modeling of the combustion process. Two experimental facilities were used at TAMU to study the injection of coal slurry fuels. The first experimental facility incorporates General Electric locomotive engine components (injection pump, fuel line, and nozzle) and a specially designed diaphragm to separate the abrasive coal slurry fuel from the moving parts of the pump. The second experimental facility is based on an accumulator injector from General Electric. Instrumentation includes instantaneous needle lift and fuel line pressure. A pressurized visualization chamber was used to provide a spray environment which simulated the engine gas density and permitted the use of spray diagnostic techniques. The study was divided into two phases: (1) overall characterization of the spray, and (2) detailed droplet size and size distribution characterization. In addition to this overall characterization of the spray, the second phase of this study characterized the details of the atomization quality.

  8. A 1D model for the description of mixing-controlled reacting diesel sprays

    SciTech Connect

    Desantesa, J.M.; Pastor, J.V.; Garcia-Oliver, J.M.; Pastor, J.M.

    2009-01-15

    The paper reports an investigation on the transient evolution of diesel flames in terms of fuel-air mixing, spray penetration and combustion rate. A one-dimensional (1D) spray model, which was previously validated for inert diesel sprays, is extended to reacting conditions. The main assumptions of the model are the mixing-controlled hypothesis and the validity of self-similarity for conservative properties. Validation is achieved by comparing model predictions with both CFD gas jet simulations and experimental diesel spray measurements. The 1D model provides valuable insight into the evolution of the flow within the spray (momentum and mass fluxes, tip penetration, etc.) when shifting from inert to reacting conditions. Results show that the transient diesel flame evolution is mainly governed by two combustion-induced effects, namely the reduction in local density and the increase in flame radial width. (author)

  9. Removal of adhesive dusts from flue gas using corona discharges with spraying water.

    PubMed

    Xu, De-xuan; Zhao, Jian-wei; Ding, Yun-zheng; Ge, Wei-li

    2003-07-01

    Effective removal of adhesive and fine dusts from flue gas is very difficult. A new method of electrostatic precipitation of the corona discharges with spraying water (CDSW) was introduced. A new electrode configuration and the circulation spraying of water were employed in the method. The efficient electrostatic precipitation for adhesive and fine dusts can be accomplished without any drain water during a long operating period. The fundamental structure, discharge characteristics, mechanism of spraying and precipitation principle of the electrostatic precipitation using CDSW were described and analyzed. The V-I characteristics, spraying state, supplying water quantity, influence of temperature and clean of the electrodes were researched in series experiments. The treating effects of circulating spraying using the corona plasma at the same time of electrostatic precipitation were investigated. The fundamental theories and experimental data were proposed, in order to effectively remove the adhesive dusts from flue gas using CDSW in practice.

  10. Microstructure and Mechanical Properties of Spray-Formed H13 Steel Tooling

    SciTech Connect

    Yaojun Lin; Kevin M. McHugh; Young-Soo Park; Yizhang Zhou; Enrique J. Lavernia

    2005-02-01

    This paper presents results on the microstructure and hardness of spray-formed H13 (Fe-0.40C-5.00Cr-1.10V-1.30Mo (wt%)) tooling. There is very low porosity in both as-spray formed samples and aged samples. The microstructure in the as-spray-formed sample is characterized by primary carbides, acicular lower bainite, and a small amount of martensite and of retained austenite. Spray formed and aged tooling H13 has higher hardness values than those of H13 in conventional tooling. The experimental results of microstructures and hardness are rationalized on the basis of numerical analysis of cooling during processing of spray-formed tooling.

  11. Flow rate and trajectory of water spray produced by an aircraft tire

    NASA Technical Reports Server (NTRS)

    Daugherty, Robert H.; Stubbs, Sandy M.

    1986-01-01

    One of the risks associated with wet runway aircraft operation is the ingestion of water spray produced by an aircraft's tires into its engines. This problem can be especially dangerous at or near rotation speed on the takeoff roll. An experimental investigation was conducted in the NASA Langley Research Center Hydrodynamics Research Facility to measure the flow rate and trajectory of water spray produced by an aircraft nose tire operating on a flooded runway. The effects of various parameters on the spray patterns including distance aft of nosewheel, speed, load, and water depth were evaluated. Variations in the spray pattern caused by the airflow about primary structure such as the fuselage and wing are discussed. A discussion of events in and near the tire footprint concerning spray generation is included.

  12. Comparison of the performance between a spray gun and a spray boom in ornamentals.

    PubMed

    Foqué, D; Nuyttens, D

    2011-01-01

    Flemish greenhouse growers predominantly use handheld spray guns and spray lances for their crop protection purposes although these techniques are known for their heavy workload and their high operator exposure risks. Moreover, when these techniques are compared with spray boom equipment, they are often found to be less effective. On the other hand, handheld spraying techniques are less expensive and more flexible to use. Additionally, many Flemish growers are convinced that a high spray volume and spray pressure is needed to assure a good plant protection. The aim of this work was to evaluate and compare the spray deposition, penetration and uniformity between a manually pulled horizontal spray boom and a spray gun under controlled laboratory conditions. In total, six different spray application techniques were evaluated. In general, the total deposition results were comparable between the spray boom and the spray gun applications but the boom applications resulted in a more uniform spray distribution over the crop. On a plant level, the spray distribution was not uniform for the different techniques with highest deposits on the upper side of the top leaves. Using spray guns at a higher spray pressure did not improve spray penetration and deposition on the bottom side of the leaves. From the different nozzle types, the XR 80 03 gave the best results. Plant density clearly affected crop penetration and deposition on the bottom side of the leaves.

  13. Miniature paint-spray gun for recessed areas

    NASA Technical Reports Server (NTRS)

    Vanasse, M. A.

    1968-01-01

    Miniature spray gun regulates paints and other liquids to spray at close range, facilitating spraying of remote or recessed areas. Individual valves for regulating air pressure and paint maximizes atomization for low pressure spraying.

  14. Computations of turbulent evaporating sprays

    NASA Technical Reports Server (NTRS)

    Aggarwal, S. K.; Chitre, S.

    1989-01-01

    A computational study of turbulent evaporating sprays is reported. The major focus is to examine the sensitivity of the vaporization behavior of turbulent sprays to the transient liquid-phase processes. Three models considered to represent these processes are the thin skin, infinite diffusion, and diffusion limit models. Favre-averaged equations with k-epsilon-g turbulence model are employed for the gas phase. The Lagrangian approach with a stochastic separated flow method is used for the liquid phase where the effects of gas turbulence on droplet trajectories and interphase transport rates are considered using random-walk computations. Also the variable-property effects are considered in detail. Results indicate that, depending upon the boiling temperature and heat of vaporization of the fuel considered, the vaporization behavior of turbulent sprays may be quite sensitive to the modeling of transient liquid-phase processes. Thus, it is important that for most hydrocarbon fuels these processes be adequately represented in any comprehensive spray computations. The present results also provide further support to the conclusions of earlier studies which have been based on simplified spray configurations.

  15. Electrostatic spray deposition based lithium ion capacitor

    NASA Astrophysics Data System (ADS)

    Agrawal, Richa; Chen, Chunhui; Wang, Chunlei

    2016-05-01

    Conventional Electrochemical double-layer capacitors (EDLCs) are well suited as power devices that can provide large bursts of energy in short time periods. However, their relatively inferior energy densities as compared to their secondary battery counterparts limit their application in devices that require simultaneous supply of both high energy and high power. In the wake of addressing this shortcoming of EDLCs, the concept of hybridization of lithium-ion batteries (LIBs) and EDLCs has attracted significant scientific interest in recent years. Such a device, generally referred to as the "lithium-ion capacitor" typically utilizes a lithium intercalating electrode along with a fast charging capacitor electrode. Herein we have constructed a lithium hybrid electrochemical capacitor comprising a Li4Ti5O12-TiO2 (LTO-TiO2) anode and a reduced graphene oxide and carbon nanotube (rGO-CNT) composite cathode using electrostatic spray deposition (ESD). The electrodes were characterized using scanning electron microscopy and X-ray diffraction studies. Cyclic voltammetry and galvanostatic charge-discharge measurements were carried out to evaluate the electrochemical performance of the individual electrodes and the full hybrid cells.

  16. Method and apparatus for atomization and spraying of molten metals

    DOEpatents

    Hobson, D.O.; Alexeff, I.; Sikka, V.K.

    1988-07-19

    A method and device for dispersing molten metal into fine particulate spray, the method comprises applying an electric current through the molten metal and simultaneously applying a magnetic field to the molten metal in a plane perpendicular to the electric current, whereby the molten metal is caused to form into droplets at an angle perpendicular to both the electric current and the magnetic field. The device comprises a structure for providing a molten metal, appropriately arranged electrodes for applying an electric current through the molten metal, and a magnet for providing a magnetic field in a plane perpendicular to the electric current. 11 figs.

  17. Method and apparatus for atomization and spraying of molten metals

    DOEpatents

    Hobson, David O.; Alexeff, Igor; Sikka, Vinod K.

    1990-01-01

    A method and device for dispersing molten metal into fine particulate spray, the method comprises applying an electric current through the molten metal and simultaneously applying a magnetic field to the molten metal in a plane perpendicular to the electric current, whereby the molten metal is caused to form into droplets at an angle perpendicular to both the electric current and the magnetic field. The device comprises a structure for providing a molten metal, appropriately arranged electrodes for applying an electric current through the molten metal, and a magnet for providing a magnetic field in a plane perpendicular to the electric current.

  18. Combustion characteristics in the transition region of liquid fuel sprays

    NASA Technical Reports Server (NTRS)

    Cernansky, N. P.; Namer, I.; Tidona, R. J.

    1984-01-01

    A number of important effects were observed in the droplet size transition region in spray combustion systems. In this region, where the mechanism of flame propagation is transformed from diffusive to premixed dominated combustion, the following effects have been observed: (1) maxima in burning velocity; (2) extension of flammability limits; (3) minima in ignition energy; and (4) minima in NO(x) formation. Unfortunately, because of differences in experimental facilities and limitations in the ranges of experimental data, a unified description of these transition region effects is not available at this time. Consequently, a fundamental experimental investigation was initiated to study the effect of droplet size, size distribution, and operating parameters on these transition region phenomena in a single well controlled spray combustion facility.

  19. QUANTIFICATION OF HEAT FLUX FROM A REACTING THERMITE SPRAY

    SciTech Connect

    Eric Nixon; Michelle Pantoya

    2009-07-01

    Characterizing the combustion behaviors of energetic materials requires diagnostic tools that are often not readily or commercially available. For example, a jet of thermite spray provides a high temperature and pressure reaction that can also be highly corrosive and promote undesirable conditions for the survivability of any sensor. Developing a diagnostic to quantify heat flux from a thermite spray is the objective of this study. Quick response sensors such as thin film heat flux sensors can not survive the harsh conditions of the spray, but more rugged sensors lack the response time for the resolution desired. A sensor that will allow for adequate response time while surviving the entire test duration was constructed. The sensor outputs interior temperatures of the probes at known locations and utilizes an inverse heat conduction code to calculate heat flux values. The details of this device are discussed and illustrated. Temperature and heat flux measurements of various thermite spray conditions are reported. Results indicate that this newly developed energetic material heat flux sensor provides quantitative data with good repeatability.

  20. Simulation of spray dispersion in a simplified heavy vehicle wake

    SciTech Connect

    Paschkewitz, J S

    2006-01-13

    Simulations of spray dispersion in a simplified tractor-trailer wake have been completed with the goal of obtaining a better understanding of how to mitigate this safety hazard. The Generic Conventional Model (GCM) for the tractor-trailer was used. The impact of aerodynamic drag reduction devices, specifically trailer-mounted base flaps, on the transport of spray in the vehicle wake was considered using the GCM. This analysis demonstrated that base flaps including a bottom plate may actually worsen motorist visibility because of the interaction of fine spray with large vortex flows in the wake. This work suggests that to use computational fluid dynamics (CFD) to design and evaluate spray mitigation strategies the jet or sheet breakup processes can be modeled using an array of injectors of small (< 0.1 mm) water droplets; however the choice of size distribution, injection locations, directions and velocities is largely unknown and requires further study. Possible containment strategies would include using flow structures to 'focus' particles into regions away from passing cars or surface treatments to capture small drops.

  1. Heat removal characteristics of a primary containment vessel external spray

    SciTech Connect

    Kataoka, Yoshiyuki; Fujii, Tadashi; Murase, Michio

    1996-10-01

    To evaluate the heat release characteristics of a primary containment vessel (PCV) external spray (one of the PCV cooling systems utilizing the steel PCV wall as the heat transfer medium), the thermal-hydraulic characteristics of the falling liquid film on the PCV surface have been investigated experimentally. Then, the performance of the PCV external spray cooling system was evaluated using the experimental findings. The following results were obtained: (1) Heat transfer coefficients of the falling liquid film under steady-state conditions were increased as the film flow rate per unit length of the liquid film width increased, and they agreed with Wilke`s correlation within about {+-}15%. (2) The PCV surface temperature, when preheated up to 150 C, which is the supposed PCV temperature under a severe accident, decreased below 100 C within a few seconds when the PCV external spray was initiated, and boiling on the PCV surface could not be maintained. (3) Heat transfer coefficients of the falling liquid film under transient conditions were higher initially due to the boiling effect; however, they decreased rapidly and approached those under steady-state conditions. (4) The PCV external spray for the conceptually designed PCV could suppress the PCV pressure below the design goal under a severe accident.

  2. MR guided thermal therapy of pancreatic tumors with endoluminal, intraluminal and interstitial catheter-based ultrasound devices: preliminary theoretical and experimental investigations

    NASA Astrophysics Data System (ADS)

    Prakash, Punit; Salgaonkar, Vasant A.; Scott, Serena J.; Jones, Peter; Hensley, Daniel; Holbrook, Andrew; Plata, Juan; Sommer, Graham; Diederich, Chris J.

    2013-02-01

    Image-guided thermal interventions have been proposed for potential palliative and curative treatments of pancreatic tumors. Catheter-based ultrasound devices offer the potential for temporal and 3D spatial control of the energy deposition profile. The objective of this study was to apply theoretical and experimental techniques to investigate the feasibility of endogastric, intraluminal and transgastric catheter-based ultrasound for MR guided thermal therapy of pancreatic tumors. The transgastric approach involves insertion of a catheter-based ultrasound applicator (array of 1.5 mm OD x 10 mm transducers, 360° or sectored 180°, ~7 MHz frequency, 13-14G cooling catheter) directly into the pancreas, either endoscopically or via image-guided percutaneous placement. An intraluminal applicator, of a more flexible but similar construct, was considered for endoscopic insertion directly into the pancreatic or biliary duct. An endoluminal approach was devised based on an ultrasound transducer assembly (tubular, planar, curvilinear) enclosed in a cooling balloon which is endoscopically positioned within the stomach or duodenum, adjacent to pancreatic targets from within the GI tract. A 3D acoustic bio-thermal model was implemented to calculate acoustic energy distributions and used a FEM solver to determine the transient temperature and thermal dose profiles in tissue during heating. These models were used to determine transducer parameters and delivery strategies and to study the feasibility of ablating 1-3 cm diameter tumors located 2-10 mm deep in the pancreas, while thermally sparing the stomach wall. Heterogeneous acoustic and thermal properties were incorporated, including approximations for tumor desmoplasia and dynamic changes during heating. A series of anatomic models based on imaging scans of representative patients were used to investigate the three approaches. Proof of concept (POC) endogastric and transgastric applicators were fabricated and experimentally

  3. Numerical and experimental analysis of an axial flow left ventricular assist device: the influence of the diffuser on overall pump performance.

    PubMed

    Untaroiu, Alexandrina; Throckmorton, Amy L; Patel, Sonna M; Wood, Houston G; Allaire, Paul E; Olsen, Don B

    2005-07-01

    Thousands of adult cardiac failure patients may benefit from the availability of an effective, long-term ventricular assist device (VAD). We have developed a fully implantable, axial flow VAD (LEV-VAD) with a magnetically levitated impeller as a viable option for these patients. This pump's streamlined and unobstructed blood flow path provides its unique design and facilitates continuous washing of all surfaces contacting blood. One internal fluid contacting region, the diffuser, is extremely important to the pump's ability to produce adequate pressure but is challenging to manufacture, depending on the complex blade geometries. This study examines the influence of the diffuser on the overall LEV-VAD performance. A combination of theoretical analyses, computational fluid (CFD) simulations, and experimental testing was performed for three different diffuser models: six-bladed, three-bladed, and no-blade configuration. The diffuser configurations were computationally and experimentally investigated for flow rates of 2-10 L/min at rotational speeds of 5000-8000 rpm. For these operating conditions, CFD simulations predicted the LEV-VAD to deliver physiologic pressures with hydraulic efficiencies of 15-32%. These numerical performance results generally agreed within 10% of the experimental measurements over the entire range of rotational speeds tested. Maximum scalar stress levels were estimated to be 450 Pa for 6 L/min at 8000 rpm along the blade tip surface of the impeller. Streakline analysis demonstrated maximum fluid residence times of 200 ms with a majority of particles exiting the pump in 80 ms. Axial fluid forces remained well within counter force generation capabilities of the magnetic suspension design. The no-bladed configuration generated an unacceptable hydraulic performance. The six-diffuser-blade model produced a flow rate of 6 L/min against 100 mm Hg for 6000 rpm rotational speed, while the three-diffuser-blade model produced the same flow rate and

  4. Spray casting project final report

    SciTech Connect

    Churnetski, S.R.; Thompson, J.E.

    1996-08-01

    Lockheed Martin Energy Systems, Inc. (Energy Systems), along with other participating organizations, has been exploring the feasibility of spray casting depleted uranium (DU) to near-net shape as a waste minimization effort. Although this technology would be useful in a variety of applications where DU was the material of choice, this effort was aimed primarily at gamma-shielding components for use in storage and transportation canisters for high-level radioactive waste, particularly in the Multipurpose Canister (MPC) application. In addition to the waste-minimization benefits, spray casting would simplify the manufacturing process by allowing the shielding components for MPC to be produced as a single component, as opposed to multiple components with many fabrication and assembly steps. In earlier experiments, surrogate materials were used to simulate the properties (specifically reactivity and density) of DU. Based on the positive results from those studies, the project participants decided that further evaluation of the issues and concerns that would accompany spraying DU was warranted. That evaluation occupied substantially all of Fiscal Year 1995, yielding conceptual designs for both an intermediate facility and a production facility and their associated engineering estimates. An intermediate facility was included in this study to allow further technology development in spraying DU. Although spraying DU to near-net shape seems to be feasible, a number of technical, engineering, and safety issues would need to be evaluated before proceeding with a production facility. This report is intended to document the results from the spray-casting project and to provide information needed by anyone interested in proceeding to the next step.

  5. Thermal Spray Coatings for Coastal Infrastructure

    SciTech Connect

    Holcomb, G.R.; Covino, BernardS. Jr.; Cramer, S.D.; Bullard, S.J.

    1997-11-01

    Several protection strategies for coastal infrastructure using thermal-spray technology are presented from research at the Albany Research Center. Thermal-sprayed zinc coatings for anodes in impressed current cathodic protection systems are used to extend the service lives of reinforced concrete bridges along the Oregon coast. Thermal-sprayed Ti is examined as an alternative to the consumable zinc anode. Sealed thermal-sprayed Al is examined as an alternative coating to zinc dust filled polyurethane paint for steel structures.

  6. Spray patternation at high pressure

    NASA Astrophysics Data System (ADS)

    Cohen, J. M.; Rosfjord, T. J.

    1989-07-01

    The spatial distribution of the fuel spray created by a gas turbine fuel injector has been measured at high pressure and temperature. A patternation system for measuring fuel spray mass flux distributions at high power conditions has been designed and operated. The facility has been designed to simulate the environment inside a gas turbine combustor as closely as possible. Results for a full scale gas turbine fuel injector have been obtained at high levels of pressure, temperature and liquid flowrate and compared with visual observations.

  7. Feedback enhanced plasma spray tool

    DOEpatents

    Gevelber, Michael Alan; Wroblewski, Donald Edward; Fincke, James Russell; Swank, William David; Haggard, Delon C.; Bewley, Randy Lee

    2005-11-22

    An improved automatic feedback control scheme enhances plasma spraying of powdered material through reduction of process variability and providing better ability to engineer coating structure. The present inventors discovered that controlling centroid position of the spatial distribution along with other output parameters, such as particle temperature, particle velocity, and molten mass flux rate, vastly increases control over the sprayed coating structure, including vertical and horizontal cracks, voids, and porosity. It also allows improved control over graded layers or compositionally varying layers of material, reduces variations, including variation in coating thickness, and allows increasing deposition rate. Various measurement and system control schemes are provided.

  8. Nanoparticles by spray drying using innovative new technology: the Büchi nano spray dryer B-90.

    PubMed

    Li, Xiang; Anton, Nicolas; Arpagaus, Cordin; Belleteix, Fabrice; Vandamme, Thierry F

    2010-10-15

    Spray drying technology is widely known and used to transform liquids (solutions, emulsions, suspension, slurries, pastes or even melts) into solid powders. Its main applications are found in the food, chemical and materials industries to enhance ingredient conservation, particle properties, powder handling and storage etc. However, spray drying can also be used for specific applications in the formulation of pharmaceuticals for drug delivery (e.g. particles for pulmonary delivery). Büchi is a reference in the development of spray drying technology, notably for laboratory scale devices. This study presents the Nano Spray Dryer B-90, a revolutionary new sprayer developed by Büchi, use of which can lower the size of the produced dried particles by an order of magnitude attaining submicron sizes. In this paper, results are presented with a panel of five representative polymeric wall materials (arabic gum, whey protein, polyvinyl alcohol, modified starch, and maltodextrin) and the potentials to encapsulate nano-emulsions, or to formulate nano-crystals (e.g. from furosemide) are also shown.

  9. Numerical Modeling of Suspension HVOF Spray

    NASA Astrophysics Data System (ADS)

    Jadidi, M.; Moghtadernejad, S.; Dolatabadi, A.

    2016-02-01

    A three-dimensional two-way coupled Eulerian-Lagrangian scheme is used to simulate suspension high-velocity oxy-fuel spraying process. The mass, momentum, energy, and species equations are solved together with the realizable k-ɛ turbulence model to simulate the gas phase. Suspension is assumed to be a mixture of solid particles [mullite powder (3Al2O3·2SiO2)], ethanol, and ethylene glycol. The process involves premixed combustion of oxygen-propylene, and non-premixed combustion of oxygen-ethanol and oxygen-ethylene glycol. One-step global reaction is used for each mentioned reaction together with eddy dissipation model to compute the reaction rate. To simulate the droplet breakup, Taylor Analogy Breakup model is applied. After the completion of droplet breakup, and solvent evaporation/combustion, the solid suspended particles are tracked through the domain to determine the characteristics of the coating particles. Numerical simulations are validated against the experimental results in the literature for the same operating conditions. Seven or possibly eight shock diamonds are captured outside the nozzle. In addition, a good agreement between the predicted particle temperature, velocity, and diameter, and the experiment is obtained. It is shown that as the standoff distance increases, the particle temperature and velocity reduce. Furthermore, a correlation is proposed to determine the spray cross-sectional diameter and estimate the particle trajectories as a function of standoff distance.

  10. Flow characteristic of in-flight particles in supersonic plasma spraying process

    NASA Astrophysics Data System (ADS)

    Wei, Pei; Wei, Zhengying; Zhao, Guangxi; Du, Jun; Bai, Y.

    2016-09-01

    In this paper, a computational model based on supersonic plasma spraying (SAPS) is developed to describe the plasma jet coupled with the injection of carrier gas and particles for SAPS. Based on a high-efficiency supersonic spraying gun, the 3D computational model of spraying gun was built to study the features of plasma jet and its interactions with the sprayed particles. Further the velocity and temperature of in-flight particles were measured by Spray Watch 2i, the shape of in-flight particles was observed by scanning electron microscope. Numerical results were compared with the experimental measurements and a good agreement has been achieved. The flight process of particles in plasma jet consists of three stages: accelerated stage, constant speed stage and decelerated stage. Numerical and experimental indicates that the H2 volume fraction in mixture gas of Ar + H2 should keep in the range of 23-26 %, and the distance of 100 mm is the optimal spraying distance in Supersonic atmosphere plasma spraying. Particles were melted and broken into small child particles by plasma jet and the diameters of most child particles were less than 30 μm. In general, increasing the particles impacting velocity and surface temperature can decrease the coating porosity.

  11. Characterization of Liquid Fuel Evaporation of a Lifted Methanol Spray Flame in a Vitiated Coflow Burner

    NASA Technical Reports Server (NTRS)

    Cabra, Ricardo; Dibble, Robert W.; Chen, Jyh-Yuan

    2002-01-01

    An experimental investigation of lifted spray flames in a coflow of hot, vitiated gases is presented. The vitiated coflow burner is a spray flame that issues into a coaxial flow of hot combustion products from a lean, premixed H2/Air flame. The spray flame in a vitiated coflow emulates the combustion that occurs in many advanced combustors without the detailed fluid mechanics. Two commercially available laser diagnostic systems are used to characterize the spray flame and to demonstrate the vitiated coflow burner's amenability to optical investigation. The Ensemble Particle Concentration and Size (EPCS) system is used to measure the path-average droplet size distribution and liquid volume fraction at several axial locations while an extractive probe instrument named the Real-time Fuel-air Analyzer (RFA) is used to measure the air to fuel ratio downstream of the spray nozzle with high temporal and spatial resolution. The effect of coflow conditions (stoichiometry) and dilution of the fuel with water was studied with the EPCS optical system. As expected, results show that water retards the evaporation and combustion of fuels. Measurements obtained by the RFA extractive probe show that while the Delavan manufactured nozzle does distribute the fuel over the manufacturer specified spray angle, it unfortunately does not distribute the fuel uniformly, providing conditions that may result in the production of unwanted NOx. Despite some limitations due to the inherent nature of the experimental techniques, the two diagnostics can be readily applied to spray flames in the vitiated coflow environment.

  12. The development and application of an automatic boundary segmentation methodology to evaluate the vaporizing characteristics of diesel spray under engine-like conditions

    NASA Astrophysics Data System (ADS)

    Ma, Y. J.; Huang, R. H.; Deng, P.; Huang, S.

    2015-04-01

    Studying the vaporizing characteristics of diesel spray could greatly help to reduce engine emission and improve performance. The high-speed schlieren imaging method is an important optical technique for investigating the macroscopic vaporizing morphological evolution of liquid fuel, and pre-combustion constant volume combustion bombs are often used to simulate the high pressure and high temperature conditions occurring in diesel engines. Complicated background schlieren noises make it difficult to segment the spray region in schlieren spray images. To tackle this problem, this paper develops a vaporizing spray boundary segmentation methodology based on an automatic threshold determination algorithm. The methodology was also used to quantify the macroscopic characteristics of vaporizing sprays including tip penetration, near-field and far-field angles, and projected spray area and spray volume. The spray boundary segmentation methodology was realized in a MATLAB-based program. Comparisons were made between the spray characteristics obtained using the program method and those acquired using a manual method and the Hiroyasu prediction model. It is demonstrated that the methodology can segment and measure vaporizing sprays precisely and efficiently. Furthermore, the experimental results show that the spray angles were slightly affected by the injection pressure at high temperature and high pressure and under inert conditions. A higher injection pressure leads to longer spray tip penetration and a larger projected area and volume, while elevating the temperature of the environment can significantly promote the evaporation of cold fuel.

  13. Tailoring the Spray Conditions for Suspension Plasma Spraying

    NASA Astrophysics Data System (ADS)

    Joulia, A.; Duarte, W.; Goutier, S.; Vardelle, M.; Vardelle, A.; Rossignol, S.

    2015-01-01

    The plasma spray process using suspensions as liquid feedstock allows the deposition of finely structured coatings with improved properties compared to that of coatings deposited by the conventional plasma spray techniques. The evaporation of the solvent, acceleration, heating, and melting of the fine solid particles within the plasma jet take place in a shorter time, as the substrate is located closer to the plasma torch when a mono-cathode mono-anode plasma torch is used, while the liquid material processing globally consumes more energy than a powder material. Therefore, achieving a coating with the expected properties requires a broad understanding of the process. In this study, a large range of plasma spray conditions have been used to achieve yttria-stabilized zirconia coatings by suspension plasma spraying. The properties of the plasma jet (velocity, enthalpy, and stability) as well as those of droplets (trajectories, number, and size) and particles (velocity) were measured and correlated to the coating microstructure. The operating conditions necessary for obtaining disk-shape splats and achieving homogeneous coatings are described including the plasma jet properties and substrate parameters.

  14. Fabrication of flexible ultraviolet photodetectors using an all-spray-coating process

    NASA Astrophysics Data System (ADS)

    Han, Junebeom; Lee, Jonghun; Ju, Sanghyun

    2016-04-01

    We report on a flexible ultraviolet (UV) photodetector fabricated using an all-spray-coating process. Two spray coating units were utilized to deposit semiconducting tin oxide nanowires as an active channel layer and metallic silver nanowires as an electrode layer. The device was mounted on the back of a human hand, and the UV intensities in sunlight were monitored over time. The fabricated flexible UV photodetector showed highly sensitive, stable, and reproducible detection properties. The main advantage of the proposed fabrication method is the extension of the integration environment by allowing direct application on various substrates, such as clothes and human skin, with varying device size and shape.

  15. 14 CFR 27.239 - Spray characteristics.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Spray characteristics. 27.239 Section 27... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Ground and Water Handling Characteristics § 27.239 Spray characteristics. If certification for water operation is requested, no spray...

  16. 14 CFR 29.239 - Spray characteristics.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Spray characteristics. 29.239 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Ground and Water Handling Characteristics § 29.239 Spray characteristics. If certification for water operation is requested, no spray...

  17. 14 CFR 23.239 - Spray characteristics.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Spray characteristics. 23.239 Section 23.239 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Handling Characteristics § 23.239 Spray characteristics. Spray may not dangerously obscure the vision...

  18. 14 CFR 27.239 - Spray characteristics.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Spray characteristics. 27.239 Section 27.239 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Spray characteristics. If certification for water operation is requested, no spray...

  19. 14 CFR 27.239 - Spray characteristics.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Spray characteristics. 27.239 Section 27.239 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Spray characteristics. If certification for water operation is requested, no spray...

  20. 14 CFR 29.239 - Spray characteristics.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Spray characteristics. 29.239 Section 29.239 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Spray characteristics. If certification for water operation is requested, no spray...

  1. 14 CFR 27.239 - Spray characteristics.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Spray characteristics. 27.239 Section 27.239 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Spray characteristics. If certification for water operation is requested, no spray...

  2. 21 CFR 524.2482 - Triamcinolone spray.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Triamcinolone spray. 524.2482 Section 524.2482... Triamcinolone spray. (a) Specifications. Each milliliter of solution contains 0.15 milligrams triamcinolone...) Amount. Apply sufficient pump sprays to uniformly and thoroughly wet the affected areas while...

  3. 21 CFR 524.2482 - Triamcinolone spray.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Triamcinolone spray. 524.2482 Section 524.2482... Triamcinolone spray. (a) Specifications. Each milliliter of solution contains 0.15 milligrams triamcinolone...) Amount. Apply sufficient pump sprays to uniformly and thoroughly wet the affected areas while...

  4. 14 CFR 23.239 - Spray characteristics.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Spray characteristics. 23.239 Section 23.239 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Handling Characteristics § 23.239 Spray characteristics. Spray may not dangerously obscure the vision...

  5. 21 CFR 524.2482 - Triamcinolone spray.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Triamcinolone spray. 524.2482 Section 524.2482... Triamcinolone spray. (a) Specifications. Each milliliter of solution contains 0.15 milligrams triamcinolone...) Amount. Apply sufficient pump sprays to uniformly and thoroughly wet the affected areas while...

  6. 14 CFR 29.239 - Spray characteristics.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Spray characteristics. 29.239 Section 29.239 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Spray characteristics. If certification for water operation is requested, no spray...

  7. 21 CFR 524.2482 - Triamcinolone spray.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Triamcinolone spray. 524.2482 Section 524.2482... Triamcinolone spray. (a) Specifications. Each milliliter of solution contains 0.15 milligrams triamcinolone...) Amount. Apply sufficient pump sprays to uniformly and thoroughly wet the affected areas while...

  8. 14 CFR 23.239 - Spray characteristics.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Spray characteristics. 23.239 Section 23.239 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Handling Characteristics § 23.239 Spray characteristics. Spray may not dangerously obscure the vision...

  9. 14 CFR 29.239 - Spray characteristics.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Spray characteristics. 29.239 Section 29.239 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Spray characteristics. If certification for water operation is requested, no spray...

  10. 14 CFR 27.239 - Spray characteristics.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Spray characteristics. 27.239 Section 27.239 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Spray characteristics. If certification for water operation is requested, no spray...

  11. 14 CFR 29.239 - Spray characteristics.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Spray characteristics. 29.239 Section 29.239 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Spray characteristics. If certification for water operation is requested, no spray...

  12. 21 CFR 524.2482 - Triamcinolone spray.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Triamcinolone spray. 524.2482 Section 524.2482... Triamcinolone spray. (a) Specifications. Each milliliter of solution contains 0.15 milligrams triamcinolone...) Amount. Apply sufficient pump sprays to uniformly and thoroughly wet the affected areas while...

  13. 14 CFR 23.239 - Spray characteristics.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Spray characteristics. 23.239 Section 23.239 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Handling Characteristics § 23.239 Spray characteristics. Spray may not dangerously obscure the vision...

  14. How to Use Nasal Pump Sprays

    MedlinePlus

    Using Nasal Pump SpraysBlow your nose gently before using the spray. Prime the pump bottle by spraying it into the air a ... Breathe in quickly while squeezing down on the pump bottle one time. Repeat in other nostril. Do ...

  15. Japan's research on particle clouds and sprays

    NASA Technical Reports Server (NTRS)

    Sato, Jun'ichi

    1995-01-01

    Most of energy used by us is generated by combustion of liquid and solid fuels. These fuels are burned in combustors mainly as liquid sprays and pulverized solids, respectively. A knowledge of the combustion processes in combustors is needed to achieve proper designs that have stable operation, high efficiency, and low emission levels. However, current understanding of liquid and solid particle cloud combustion is far from complete. If combustion experiments for these fuels are performed under a normal gravity field, some experimental difficulties are encountered. These difficulties encountered include, that since the particles fall by the force of gravity it is impossible to stop the particles in the air, the falling speeds of particles are different from each other, and are depend on the particle size, the flame is lifted up and deformed by the buoyancy force, and natural convection makes the flow field more complex. Since these experimental difficulties are attributable to the gravity force, a microgravity field can eliminate the above problems. This means that the flame propagation experiments in static homogeneous liquid and solid particle clouds can be carried out under a microgravity field. This will provide much information for the basic questions related to combustion processes of particle clouds and sprays. In Japan, flame propagation processes in the combustible liquid and solid particle clouds have been studied experimentally by using a microgravity field generated by a 4.5 s dropshaft, a 10 s dropshaft, and by parabolic flight. Described in this presentation are the recent results of flame propagations studies in a homogeneous liquid particle cloud, in a mixture of liquid particles/gas fuel/air, in a PMMA particle cloud, and in a pulverized coal particle cloud.

  16. The Effect of Spray Initial Conditions on Heat Release and Emissions in LDI CFD Calculations

    NASA Technical Reports Server (NTRS)

    Iannetti, Anthony C.; Liu, Nan-Suey; Davoudzadeh, Farhad

    2008-01-01

    The mass and velocity distribution of liquid spray has a primary effect on the combustion heat release process. This heat release process then affects emissions like nitrogen oxides (NOx) and carbon monoxide (CO). Computational Fluid Dynamics gives the engineer insight into these processes, but various setup options exist (number of droplet groups, and initial droplet temperature) for spray initial conditions. This paper studies these spray initial condition options using the National Combustion Code (NCC) on a single swirler lean direct injection (LDI) flame tube. Using laminar finite rate chemistry, comparisons are made against experimental data for velocity measurements, temperature, and emissions (NOx, CO).

  17. An experimental investigation of using carbon foam-PCM-MWCNTs composite materials for thermal management of electronic devices under pulsed power modes

    NASA Astrophysics Data System (ADS)

    Alshaer, W. G.; Rady, M. A.; Nada, S. A.; Palomo Del Barrio, Elena; Sommier, Alain

    2016-05-01

    The present article reports on a detailed experimental investigation of using carbon foam-PCM-MWCNTs composite materials for thermal management (TM) of electronic devices subjected to pulsed power. The TM module was fabricated by infiltrating paraffin wax (RT65) as a phase change material (PCM) and multi walled carbon nanotubes (MWCNTs) as a thermal conductivity enhancer in a carbon foam as a base structure. Two carbon foam materials of low and high values of thermal conductivities, CF20 and KL1-250 (3.1 and 40 W/m K), were tested as a base structure for the TM modules. Tests were conducted at different power intensities and power cycling/loading modes. Results showed that for all power varying modes and all carbon foams, the infiltration of RT65 into carbon foam reduces the temperature of TM module and results in damping the temperature spikes height. Infiltration of MWCNTS into RT65 further improves the effectiveness of TM module. Temperature damping was more pronounced in stand-alone pulsed power cycles as compared to pulsed power spikes modes. The effectiveness of inclusion of RT65 and RT65/MWCNTs in damping the temperature spikes height is remarkable in TM modules based on KL1-250 as compared to CF-20.

  18. Investigations of some aspects of the spray process in a single wire arc plasma spray system using high speed camera.

    PubMed

    Tiwari, N; Sahasrabudhe, S N; Tak, A K; Barve, D N; Das, A K

    2012-02-01

    A high speed camera has been used to record and analyze the evolution as well as particle behavior in a single wire arc plasma spray torch. Commercially available systems (spray watch, DPV 2000, etc.) focus onto a small area in the spray jet. They are not designed for tracking a single particle from the torch to the substrate. Using high speed camera, individual particles were tracked and their velocities were measured at various distances from the spray torch. Particle velocity information at different distances from the nozzle of the torch is very important to decide correct substrate position for the good quality of coating. The analysis of the images has revealed the details of the process of arc attachment to wire, melting of the wire, and detachment of the molten mass from the tip. Images of the wire and the arc have been recorded for different wire feed rates, gas flow rates, and torch powers, to determine compatible wire feed rates. High speed imaging of particle trajectories has been used for particle velocity determination using time of flight method. It was observed that the ripple in the power supply of the torch leads to large variation of instantaneous power fed to the torch. This affects the velocity of the spray particles generated at different times within one cycle of the ripple. It is shown that the velocity of a spray particle depends on the instantaneous torch power at the time of its generation. This correlation was established by experimental evidence in this paper. Once the particles leave the plasma jet, their forward speeds were found to be more or less invariant beyond 40 mm up to 500 mm from the nozzle exit.

  19. Development of Universal Portable Spray Stand for Touch-Up Process in The Automotive Paintshop

    NASA Astrophysics Data System (ADS)

    Fatah Muhamed Mukhtar, Muhamed Abdul; Mohideen Shahul Hameed, Rasool

    2016-02-01

    A spray stand is a custom-made tool used to hold the automotive body parts as well as the devices used to facilitate the operator during the Touch Up process in Paint shop production. This paper discusses about the development of Universal Portable Spray Stand (UPSS) as a tool to hold various types of automotive body parts and model of car during the painting process. The main objective of this study is to determine the effective application of UPSS at the International College of Automotive (ICAM) and also in the automotive industry. This will be helpful to add features to the current spray stand in ICAM and to add value to the spray stand based on selected criteria which are universal, portable and cost saving. In addition, study in the UPSS is also expected to bring reduction in cycle time during the touch up process, in the paint defects and in the ergonomics issues among the operators.

  20. Chlorhexidine spray as an adjunct in the control of dental biofilm in children with special needs.

    PubMed

    Viana, Gilberg Resende; Teiltelbaum, Ana Paula; dos Santos, Fábio André; Sabbagh-Haddad, Aida; Guaré, Renata Oliveira

    2014-01-01

    The aim of this study was to evaluate the clinical effectiveness of .12% chlorhexidine applied via spray and the acceptance. A total of 26 individuals with mental health issues, aged 7-14, were included into two groups: placebo (control, n = 13) and chlorhexidine (experimental, n = 13). Both groups received two daily applications of spray during 2 months. The periodontal conditions were evaluated by the simplified oral hygiene index (OHI-S) and gingival index (GI). The evaluation of acceptance of the application method (spray) was assessed by questionnaire. Data were analyzed with nonparametric tests, with a significance level of 5%. Regarding the OHI-S index, only the experimental group showed significant change during the evaluations (p < 0.001). Regarding the GI, both groups showed significant changes during the evaluations. The method of application was well accepted by patients and caregivers, and .12% chlorhexidine solution applied via spray significantly reduced the rates of dental and gingival biofilm.

  1. Arc-Plasma Wire Spraying: An Optical Study of Process Phenomenology

    NASA Astrophysics Data System (ADS)

    Gulyaev, I. P.; Dolmatov, A. V.; Kharlamov, M. Yu.; Gulyaev, P. Yu.; Jordan, V. I.; Krivtsun, I. V.; Korzhyk, V. M.; Demyanov, O. I.

    2015-12-01

    In the present paper, we report on the results of an experimental study of heat- and mass-transfer processes in a Plazer 30-PL-W plasma-jet facility used for arc-plasma wire spraying. Using an original optical diagnostic system, we have studied melting behavior of the metal wire, break up and atomization of liquid metal. For the first time, experimental data on the in-flight velocity and temperature of spray particles in arc-plasma wire spraying were obtained. In spite of moderate particle velocities (about 50 m/s), the obtained steel coatings proved to have a low porosity of 1.5%. While studying the spraying process of tungsten wire, we observed the occurrence of anomalous high-velocity (over 4000 m/s) outbursts ejected from the surface of liquid metal droplets. The nature of such outbursts calls for further study.

  2. Sprayer technology: reduce spray drift

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enhancing environmental quality and sustaining the economic viability of food production are keys to sustainable agriculture. Modern vegetable production uses a variety of materials to manage pest problems. Selecting the proper spray nozzle for the application of liquid products is critical to red...

  3. Spray nozzles reduce furnace emissions

    SciTech Connect

    Not Available

    1993-10-01

    When the US Environmental Protection Agency (EPA) told an Illinois wood pallet manufacturer to reduce emissions of heavy smoke from its twice-weekly incineration of old pallets, the company didn't find many options. The company applied spray nozzles to enhance the efficiency of the furnaces, and scrub the smoke and gas, removing toxins and particulates before they could reach the furnace chimney and be emitted into the atmosphere. Three types of spray nozzles were installed in the incinerator. Six UniJet air blow-off nozzles, fed by a compressed air line, were installed in the fire box. These nozzles target a flat spray of pressured air to intensify the heat of the fire. As a result, the pallets burn more efficiently and completely. Eight standard FullJet nozzles also were installed in the fire box. Since the smoke concentration is heaviest in this area, the nozzles provide the large drops and the heavy spray distribution needed to clean carbon particulates from the smoke.

  4. Spray pyrolysis of CZTS nanoplatelets.

    PubMed

    Exarhos, S; Bozhilov, K N; Mangolini, L

    2014-10-01

    We demonstrate that copper-zinc-tin-sulphide nanoplatelets can be directly grown onto a molybdenum-coated substrate using spray pyrolysis starting from a mixture of metal thiocarbamates precursors. The structure and phase purity of the nanoplatelets is discussed in detail. PMID:25119262

  5. Nasal spray flu vaccine (image)

    MedlinePlus

    The flu vaccine can also be administered as a nasal spray instead of the usual injection method. It is an ... 49 who want to be protected from the flu virus. Unlike the regular vaccine, it is a live virus. Therefore, it is ...

  6. On the structure of an electrostatic spray of monodisperse droplets

    NASA Astrophysics Data System (ADS)

    Tang, Keqi; Gomez, Alessandro

    1994-07-01

    An experimental study has been performed on the structure of an electrostatic spray of monodisperse droplets. Such a spray is established when a liquid with sufficient electric conductivity and moderate surface tension, in the present case heptane doped with an antistatic additive, is fed through a small metal tube maintained at several kilovolts relative to a ground electrode a few centimeters away. The liquid meniscus at the outlet of the capillary takes a conical shape under the action of the electric field, with a thin jet emerging from the cone tip. This jet breaks up into charged droplets that disperse into a fine spray. Flash shadowgraph of the breakup region showed that the jet initially breaks into droplets of bimodal size distribution by varicose wave instabilities. The spray monodispersity is established farther downstream by a segregation process of electrostatic and inertial nature that confines the bulk of the mass flow rate (97%) and 85% of the total current in a core of nearly monodisperse primary droplets, with the remainder in a shroud of satellites. Droplet size, axial velocity, and concentration were measured throughout the spray by phase Doppler anemometry (PDA). The complementary use of these measurements permitted the determination of the electric field via the spray momentum equation. It was found that droplets are ejected from the jet at a relatively high velocity in a region characterized by a very intense electric field. They maintain this velocity farther downstream because of inertia, even though the field is precipitously decreasing, and ultimately decelerate under the action of the drag force and a progressively weaker electrostatic force. Velocity and concentration fields were shown to be self-similar. Comparison between the external field, due to the potential difference applied between the electrodes, and the space charge field shows that the droplet axial motion is driven primarily by the external field, whereas the droplet radial

  7. SURFACTANT SPRAY: A NOVEL TECHNOLOGY TO IMPROVE FLOTATION DEINKING PERFORMANCE

    SciTech Connect

    Yulin Deng; Junyong Zhu

    2004-01-31

    Based on the fundamental understanding of ink removal and fiber loss mechanism in flotation deinking process, we developed this innovative technology using surfactant spray to improve the ink removal efficiency, reduce the water and fiber loss, reduce the chemical consumption and carry over in the flotation deinking. The innovative flotation deinking process uses a spray to deliver the frothing agent during flotation deinking to control several key process variables. The spray can control the foam stability and structure and modify the fluid dynamics to reduce the fibers entrapped in the froth layer. The froth formed at the top part of the flotation column will act as a physical filter to prevent the penetration of frothing agent into the pulp suspension to eliminate fiber contamination and unfavorable deinking surface chemistry modification due to surfactant adsorption on the fiber surface. Because of the filter effect, frothing agents will be better utilized. Under the sponsorships of the US Dept. of Energy (DOE) and the member companies of the Institute of Paper Science and Technology, we studied the chem-mechanical mechanism of surfactant spray for flotation deinking using different furnishes, chemicals, and flotation devices in the past four years. In the final year of the project, we successfully conducted mill trials at Abitibi-Consolidated, Inc., Snowflake paper recycling operation of 100% mixture of ONP/OMG. Results from laboratory, pilot-plant and mill trials indicated that surfactant spray technology can significantly reduce fiber loss in flotation deinking. It can be concluded that paper industry can profit greatly when this technology is commercialized in flotation deinking mills.

  8. Effect of spray particle trajectory on the measurement signal of particle parameters based on thermal radiation

    NASA Astrophysics Data System (ADS)

    Li, Chang-Jiu; Wu, Tao; Li, Cheng-Xin; Sun, Bo

    2003-03-01

    The influences of the dimensions of optical components and the trajectories of spray particles on the variations of the waveforms of the radiation signals from the spray particles were studied both theoretically and experimentally for correct simultaneous measurement of the particle parameters including particle velocity, surface temperature, size, and spatial distribution. Two types of filtering masks, including single-windowed and dual-windowed, were used as models in the current study. The evolution of the radiation pulse from a moving thermal spray particle was simulated through the change of the projected area of the particle image spot on the filtering mask window. The experimental detection of the thermal radiation pulses was performed for the high velocity oxygen fuel (HVOF) process using an optoelectronic measurement system. The theoretical simulation clearly showed that the characteristic waveforms of the thermal radiation signals from the spray particles are varied with the distance and orientation of the trajectories of thermal spray particles with respect to the ideal image plane of the filtering window plane. The typical variations of the characteristic waveforms obtained theoretically have been observed experimentally with HVOF spraying. The waveforms expected theoretically were correlated well with those observed experimentally. The characteristic waveforms of the radiation signals from the spray particles in a trapezoid shape with a saturated top platform contain the information for spray particle parameters including velocity, surface temperature, size, and spatial distribution. With the dual-windowed filtering mask, the particle velocity can be correctly measured with the bi-peak radiation signal in triangle-like shape, and the surface temperature may be estimated reasonably. However, the particle size cannot be estimated correctly. It was revealed that the characteristics of the waveforms were remarkably influenced by the image spot size

  9. Atmospheric pressure plasma jet for liquid spray treatment

    NASA Astrophysics Data System (ADS)

    Mitić, S.; Philipps, J.; Hofmann, D.

    2016-05-01

    Atmospheric pressure plasma jets have been intensively studied in recent years due to growing interest in their use for biomedical applications and surface treatments. Either surfaces can be treated by a plasma jet afterglow for cleaning or activation or a material can be deposited by a reactive gas component activated by plasma. Effects of plasma on liquid have been reported several times where the electron spin trapping method was used for radical detection. Here we propose another method of liquid treatment using the atmospheric pressure plasma jet. In the device presented here, liquid was sprayed in droplets from an inner electrode directly into a plasma jet where it was treated and sprayed out by gas flow. Optical end electrical measurements were done for diagnostics of the plasma while electron paramagnetic resonance measurements were used for detection of radicals (\\text{OH},\\text{OOH},\\text{CH} ) produced by plasma treatment of liquids.

  10. Hierarchical Formation of Intrasplat Cracks in Thermal Spray Ceramic Coatings

    NASA Astrophysics Data System (ADS)

    Chen, Lin; Yang, Guan-Jun; Li, Cheng-Xin; Li, Chang-Jiu

    2016-06-01

    Intrasplat cracks, an essential feature of thermally sprayed ceramic coatings, play important roles in determining coating properties. However, final intrasplat crack patterns are always considered to be disordered and irregular, resulting from random cracking during splat cooling, since the detailed formation process of intrasplat cracks has scarcely been considered. In the present study, the primary formation mechanism for intrasplat cracking was explored based on both experimental observations and mechanical analysis. The results show that the intrasplat crack pattern in thermally sprayed ceramic splats presents a hierarchical structure with four sides and six neighbors, indicating that intrasplat crack patterns arise from successive domain divisions due to sequential cracking during splat cooling. The driving forces for intrasplat cracking are discussed, and the experimental data quantitatively agree well with theoretical results. This will provide insight for further coating structure designs and tailoring by tuning of intrasplat cracks.

  11. A Validation Summary of the NCC Turbulent Reacting/non-reacting Spray Computations

    NASA Technical Reports Server (NTRS)

    Raju, M. S.; Liu, N.-S. (Technical Monitor)

    2000-01-01

    This pper provides a validation summary of the spray computations performed as a part of the NCC (National Combustion Code) development activity. NCC is being developed with the aim of advancing the current prediction tools used in the design of advanced technology combustors based on the multidimensional computational methods. The solution procedure combines the novelty of the application of the scalar Monte Carlo PDF (Probability Density Function) method to the modeling of turbulent spray flames with the ability to perform the computations on unstructured grids with parallel computing. The calculation procedure was applied to predict the flow properties of three different spray cases. One is a nonswirling unconfined reacting spray, the second is a nonswirling unconfined nonreacting spray, and the third is a confined swirl-stabilized spray flame. The comparisons involving both gas-phase and droplet velocities, droplet size distributions, and gas-phase temperatures show reasonable agreement with the available experimental data. The comparisons involve both the results obtained from the use of the Monte Carlo PDF method as well as those obtained from the conventional computational fluid dynamics (CFD) solution. Detailed comparisons in the case of a reacting nonswirling spray clearly highlight the importance of chemistry/turbulence interactions in the modeling of reacting sprays. The results from the PDF and non-PDF methods were found to be markedly different and the PDF solution is closer to the reported experimental data. The PDF computations predict that most of the combustion occurs in a predominantly diffusion-flame environment. However, the non-PDF solution predicts incorrectly that the combustion occurs in a predominantly vaporization-controlled regime. The Monte Carlo temperature distribution shows that the functional form of the PDF for the temperature fluctuations varies substantially from point to point. The results also bring to the fore some of the

  12. Performance Analysis and Modeling of Thermally Sprayed Resistive Heaters

    NASA Astrophysics Data System (ADS)

    Lamarre, Jean-Michel; Marcoux, Pierre; Perrault, Michel; Abbott, Richard C.; Legoux, Jean-Gabriel

    2013-08-01

    Many processes and systems require hot surfaces. These are usually heated using electrical elements located in their vicinity. However, this solution is subject to intrinsic limitations associated with heating element geometry and physical location. Thermally spraying electrical elements directly on surfaces can overcome these limitations by tailoring the geometry of the heating element to the application. Moreover, the element heat transfer is maximized by minimizing the distance between the heater and the surface to be heated. This article is aimed at modeling and characterizing resistive heaters sprayed on metallic substrates. Heaters were fabricated by using a plasma-sprayed alumina dielectric insulator and a wire flame-sprayed iron-based alloy resistive element. Samples were energized and kept at a constant temperature of 425 °C for up to 4 months. SEM cross-sectional observations revealed the formation of cracks at very specific locations in the alumina layer after thermal use. Finite-element modeling shows that these cracks originate from high local thermal stresses and can be predicted according to the considered geometry. The simulation model was refined using experimental parameters obtained by several techniques such as emissivity and time-dependent temperature profile (infra-red camera), resistivity (four-probe technique), thermal diffusivity (laser flash method), and mechanical properties (micro and nanoindentation). The influence of the alumina thickness and the substrate material on crack formation was evaluated.

  13. Measurement of fuel spray vaporisation by laser techniques

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

    Comparison of fuel spray structures in heated and in cold environments is made by using a new laser tomographic technique and laser anemometry. The tomography technique is shown to give accurate and rapid 'point' measurements of droplet sizes and concentrations. Experimental results show acceleration of droplets to the local gas velocity, preferential vaporisation of the smallest droplets and the dispersion of droplets by the turbulence.

  14. Study of fracture and erosive wear of plasma sprayed coatings

    SciTech Connect

    Guo, D.Z.; Wang, L.J. )

    1993-09-01

    It is experimentally established that both the double-cantilever and short-bar methods are able to ascertain the G(Ic) of plasma-sprayed coatings. WC-Co- and ZrO2-base coatings are examined by these means; the G(Ic) of the former is found to be higher than that of the latter, and WC-Co coatings are also found to be the more erosion-resistant of the two. 15 refs.

  15. Combustion of LOX with H2(sub g) under subcritical, critical, and supercritical conditions (Task 1) and experimental observation of dense spray and mixing of impinging jets (Task 2)

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

    The objective was to achieve a better understanding of the combustion processes of liquid oxygen and gaseous hydrogen under broad range of pressure covering subcritical, critical, and supercritical conditions. The scope of the experimental work falls into the following areas: (1) design of the overall experimental setup; (2) modification of an existing windowed high pressure chamber; (3) design of the LOX feeding system; (4) provision of the safety features in the test rig design; (5) LOX cleanliness requirements; (6) cold shock testing; (7) implementation of data acquisition systems; (8) preliminary tests for system checkout; (9) modification of LOX feeding system; and (10) evaporation tests. Progress in each area is discussed.

  16. Cold Spray Forming of Inconel 718

    NASA Astrophysics Data System (ADS)

    Wong, W.; Irissou, E.; Vo, P.; Sone, M.; Bernier, F.; Legoux, J.-G.; Fukanuma, H.; Yue, S.

    2013-03-01

    Inconel 718 was cold spray formed to a 6-mm thickness on an 8-cm diameter aluminum alloy tube using Sulzer Amdry 1718 powder and the Plasma Giken PCS-1000 cold spray system. The effects of spray particle velocity and post-spray heat treatment were studied. Post-spray annealing was performed from 950 to 1250 °C for 1-2 h. The resulting microstructures as well as the corresponding mechanical properties were characterized. As-sprayed coatings exhibited very low ductility. The tensile strength and ductility of the heat-treated coatings were improved to varying levels depending on the heat-treatment and spray conditions. For coatings sprayed at higher particle velocity and heat treated at 1250 °C for 1 h, an elongation of 24% was obtained. SEM micrographs showed a higher fraction of interparticle metallurgical bonds due to some sintering effect. Corresponding fracture surfaces also revealed a higher fraction of dimple features, typically associated with ductile fracture, in the annealed coatings. The results demonstrate that cold spray forming of Inconel 718 is feasible, and with appropriate heat treatment, metallurgical bonding can be increased. The ductility of the spray-formed samples was comparable to that of the bulk material.

  17. Spray combustion at normal and reduced gravity in counterflow and co-flow configurations

    NASA Technical Reports Server (NTRS)

    Gomez, Alessandro; Chen, Gung

    1995-01-01

    Liquid fuel dispersion in practical systems is typically achieved by spraying the fuel into a polydisperse distribution of droplets evaporating and burning in a turbulent gaseous environment In view of the nearly insurmountable difficulties of this two-phase flow, a systematic study of spray evaporation and burning in configurations of gradually increasing levels of complexity, starting from laminar sprays to fully turbulent ones, would be useful. A few years ago we proposed to use an electrostatic spray of charged droplets for this type of combustion experiments under well-defined conditions. In the simplest configuration, a liquid is fed into a small metal tube maintained at several kilovolts relative to a ground electrode few centimeters away. Under the action of the electric field, the liquid meniscus at the outlet of the capillary takes a conical shape, with a thin jet emerging from the cone tip (cone-jet mode). This jet breaks up farther downstream into a spray of charged droplets - the so-called ElectroSpray (ES). Several advantages distinguish the electrospray from alternative atomization techniques: (1) it can produce quasi-monodisperse droplets over a phenomenal size range; (2) the atomization, that is strictly electrostatic, is decoupled from gas flow processes, which provides some flexibility in the selection and control of the experimental conditions; (3) the Coulombic repulsion of homopolarly charged droplets induces spray self-dispersion and prevents droplet coalescence; (4) the ES provides the opportunity of studying regimes of slip between droplets and host gas without compromising the control of the spray properties; and (5) the compactness and potential controllability of this spray generation system makes it appealing for studies in reduced-gravity environments aimed at isolating the spray behavior from natural convection complications. With these premises, in March 1991 we initiated a series of experiments under NASA sponsorship (NAG3-1259 and

  18. The magnetic properties of plasma-sprayed thick-film manganese zinc ferrite (MZF) and nickel iron alloy (Permalloy) composites

    SciTech Connect

    Liang, S.; Gambino, R. J.; Sampath, S.; Raja, M. M.

    2006-04-15

    MnZn ferrite/Permalloy composites have potential in high frequency magnetic applications and can be made into thick-film devices by air plasma spray. The as-sprayed composites have lower saturation magnetization than the starting powder. After annealing below 600 deg. C, the magnetic properties and electrical resistivity improve significantly. The changes in magnetic and electrical properties were correlated to structural changes and studied by x-ray-diffraction analysis, vibrating-sample magnetometer measurements, and microstructural analysis.

  19. Uniform-droplet spray forming

    SciTech Connect

    Blue, C.A.; Sikka, V.K.; Chun, Jung-Hoon; Ando, T.

    1997-04-01

    The uniform-droplet process is a new method of liquid-metal atomization that results in single droplets that can be used to produce mono-size powders or sprayed-on to substrates to produce near-net shapes with tailored microstructure. The mono-sized powder-production capability of the uniform-droplet process also has the potential of permitting engineered powder blends to produce components of controlled porosity. Metal and alloy powders are commercially produced by at least three different methods: gas atomization, water atomization, and rotating disk. All three methods produce powders of a broad range in size with a very small yield of fine powders with single-sized droplets that can be used to produce mono-size powders or sprayed-on substrates to produce near-net shapes with tailored microstructures. The economical analysis has shown the process to have the potential of reducing capital cost by 50% and operating cost by 37.5% when applied to powder making. For the spray-forming process, a 25% savings is expected in both the capital and operating costs. The project is jointly carried out at Massachusetts Institute of Technology (MIT), Tuffs University, and Oak Ridge National Laboratory (ORNL). Preliminary interactions with both finished parts and powder producers have shown a strong interest in the uniform-droplet process. Systematic studies are being conducted to optimize the process parameters, understand the solidification of droplets and spray deposits, and develop a uniform-droplet-system (UDS) apparatus appropriate for processing engineering alloys.

  20. Effect of vaporization on cryogenic spray dropsize measurement

    NASA Technical Reports Server (NTRS)

    Ingebo, Robert D.

    1993-01-01

    The fluid mechanics of multi-phase flow breakup of liquid nitrogen, LN2, jets injected into sonic velocity nitrogen gasflow, was experimentally investigated. A scattered-light scanning instrument was used to measure the characteristic dropsize, D(sub v.5), of LN2 sprays and to determine the effect of droplet vaporization on experimental dropsize measurements. Under sonic gas-velocity conditions, liquid-jet breakup occurred in the regime of aerodynamic stripping. As a result, the following correlation of volume-median drop diameter, D(sub v.5), with atomizing gas flowrate, W(sub g), was derived for two-fluid atomizers: (D(sub v.5)) (exp -1) = k(sub c) (W(sub g)) (sup n), where proportionally constant k(sub c) and exponent n are functions of droplet vaporization rate. Partially vaporized sprays were investigated and it was found that n = 1.11, which is considerably less than the value of 1.33 that is predicted by atomization theory. This was attributed to the evaporative loss of very small droplets. As a result, the following expression was obtained experimentally: (D(sub v.5e)) (exp -1) = 301 (W(sub g)) (sub 1.11). Values of D(sub v.5), that existed prior to partial vaporization of the LN2 sprays, were calculated and the following expression was derived for originally unvaporized LN2 sprays: (D(sub v.5)) (exp -1) = 285 (W(sub g)) (sub 1.33). This expression agrees well with atomization theory that predicts n = 1.33, for liquid jet breakup in high-velocity gasflow.

  1. Effect of vaporization on cryogenic spray dropsize measurement

    NASA Technical Reports Server (NTRS)

    Ingebo, Robert D.

    1992-01-01

    The fluid mechanics of multi-phase flow breakup of liquid nitrogen, LN2, jets injected into sonic velocity nitrogen gasflow, was experimentally investigated. A scattered-light scanning instrument was used to measure the characteristic dropsize, D(sub v.5), of LN2 sprays and to determine the effect of droplet vaporization on experimental dropsize measurements. Under sonic gas-velocity conditions, liquid-jet breakup occurred in the regime of aerodynamic stripping. As a result, the following correlation of volume-median drop diameter, D(sub v.5), with atomizing gas flowrate, W(sub g), was derived for two-fluid atomizers; with atomizing gas flowrate, W(sub g), was derived for two-fluid atomizers; (D(sub v.5))(exp -1) = k(sub c)(W(sub g))(sup n), where proportionally constant k(sub c) and exponent n are functions of droplet vaporization rate. Partially vaporized sprays were investigated and it was found that n = 1.11, which is considerably less than the value of 1.33 that is predicted by atomization theory. This was attributed to the evaporative loss of very small droplets. As a result, the following expression was obtained experimentally: (D(sub v.5e))(exp -1) = 301(W(sub g))(sup 1.11). Values of D(sub v.5), that existed prior to partial vaporization of the LN2 sprays, were calculated and the following expression was derived for originally unvaporized LN2 sprays: (D(sub v.5))(exp -1) = 285(W(sub g))(sup 1.33). This expression agrees well with atomization theory that predicts n = 1.33, for liquid jet breakup in high-velocity gasflow.

  2. Coanda-assisted Spray Manipulation

    NASA Astrophysics Data System (ADS)

    Mabey, Katie; Smith, Barton; Archibald, Reid; West, Brian

    2009-11-01

    An overview of research on a flow control technique called Coanda-assisted Spray Manipulation (CSM) is presented. CSM uses a high-momentum control jet under the influence of the Coanda effect to vector a high volume-flow jet or spray. Actuators provide the capability of moving the location of applied control flow making rotary or arbitrary motion of the vectored flow possible. The presented work includes a fundamental isothermal study on the effects of rotation speed and Reynolds number on a vectored jet using a belt-driven CSM actuator. Three-component velocity data were acquired for three Reynolds numbers and three rotation speeds using timed resolved high-speed stereo Particle Image Velocimetry. A second CSM system with 16 pneumatically-driven control ports has been retrofitted to a flame spray gun. This combination provides the capability to rapidly alter the direction of applied metal powders. High speed video of this process will also be presented. Finally, a fundamental study on the pneumatic system's response to minor losses and connection lines of varying lengths is presented.

  3. Spray Characteristics of a Hybrid Twin-Fluid Pressure-Swirl Atomizer

    NASA Technical Reports Server (NTRS)

    Durham, M. J.; Sojka, P. E.; Ashmore, C. B.

    2004-01-01

    The spray performance of a fuel injection system applicable for use in main combustion chamber of an oxidizer-rich staged combustion (ORSC) cycles is presented. The experimental data reported here include mean drop size and drop size distribution, spray cone half-angle, and momentum rate (directly related to spray penetration). The maximum entropy formalism, MEF, method to predict drop size distribution is applied and compared to the experimental data. Geometric variables considered include the radius of the injector inlet orifice plate through which oxidizer flows (&) and the exposed length from the fuel inlet to the injector exit plane (L2). Operating conditions that were varied include the liquid mass flow rate and air mass flow rate. For orifices B and C there is a significant dependence of D3Z on both the air and liquid mass flow rates, as well as on L2. For the A orifice, the momentum rate of the air flow appears to exceed a threshold value above which a constant D32 is obtained. Using the MEF method, a semi-analytical process was developed to model the spray distribution using two input parameters (q = 0.4 and Dso). The momentum rate of the spray is directly related to the air and liquid mass flow rates. The cone half angle of the spray ranges from 25 to 17 degrees. The data resulting from this project will eventually be used to develop advanced rocket systems.

  4. Gas Flow, Particle Acceleration, and Heat Transfer in Cold Spray: A review

    NASA Astrophysics Data System (ADS)

    Yin, Shuo; Meyer, Morten; Li, Wenya; Liao, Hanlin; Lupoi, Rocco

    2016-06-01

    Cold spraying is increasingly attracting attentions from both scientific and industrial communities due to its unique `low-temperature' coating build-up process and its potential applications in the additive manufacturing across a variety of industries. The existing studies mainly focused on the following subjects: particle acceleration and heating, coating build-up, coating formation mechanism, coating properties, and coating applications, among which particle acceleration and heating can be regarded as the premise of the other subjects because it directly determines whether particles have sufficient energy to deposit and form the coating. Investigations on particle acceleration and heating behavior in cold spraying have been widely conducted both numerically and experimentally over decades, where many valuable conclusions were drawn. However, existing literature on this topic is vast; a systematical summery and review work is still lack so far. Besides, some curtail issues involved in modeling and experiments are still not quite clear, which needs to be further clarified. Hence, a comprehensive summary and review of the literature are very necessary. In this paper, the gas flow, particle acceleration, and heat transfer behavior in the cold spray process are systematically reviewed. Firstly, a brief introduction is given to introduce the early analytical models for predicting the gas flow and particle velocity in cold spraying. Subsequently, special attention is directed towards the application of computational fluid dynamics technique for cold spray modeling. Finally, the experimental observations and measurements in cold spraying are summarized.

  5. Macroinvertebrate responses to insecticide application between sprayed and adjacent nonsprayed ditch sections of different sizes.

    PubMed

    Brock, Theo C M; Belgers, J Dick M; Roessink, Ivo; Cuppen, Jan G M; Maund, Steve J

    2010-09-01

    Under typical agricultural use of an insecticide, it is likely that only part of an edge-of-field drainage ditch will be directly contaminated by spray drift. The response, including recovery, of aquatic macroinvertebrates in sprayed ditch sections may be affected by immigration of organisms from adjacent nonsprayed ditch sections, but also the population dynamics in nonsprayed sections (refuges) may be affected by nearby contaminated patches (known as action at a distance). Experimental ditches were used to study the influence of the presence of nearby refuges on the responses of macroinvertebrates in ditch sections directly sprayed with the insecticide lufenuron, and vice versa. The treatment regimes differed in the proportion of the ditch (0, 33, 67, and 100% of surface area) that was sprayed to reach a lufenuron concentration of 3 microg/L in the water column of the sprayed ditch section. In sprayed ditch sections, clear treatment-related effects were observed for adult midges in the emergence traps and for aquatic arthropods (mainly juveniles) in the artificial substrate/sweep net samples. The extent in magnitude and duration of effects in sprayed ditch sections was overall larger when a larger proportion of the ditch was sprayed and/or the distance to the refuge was larger. In nonsprayed ditch sections of partially treated ditches, treatment-related effects were absent or minor for macroinvertebrates that predominantly dwell on or in the sediment compartment, particularly at a larger distance from the sprayed ditch sections. More mobile arthropods that predominantly dwell in the water column showed clear treatment-related effects in the nonsprayed ditch sections as well, but action at a distance was smaller if a smaller proportion of ditch was treated. PMID:20821657

  6. Development of a plasma sprayed ceramic gas path seal for high pressure turbine applications

    NASA Technical Reports Server (NTRS)

    Shiembob, L. T.; Hyland, J. F.

    1979-01-01

    Development of the plasma sprayed graded, layered ZrO2/CoCrAlY seal system for gas turbine engine blade tip seal application up to 1589 K (2400 F) surface temperature was continued. Methods of improvement of the cyclic thermal shock resistance of the sprayed zirconia seal system were investigated. The most promising method, reduction of the ceramic thickness and metallic substrate stiffness were selected based upon potential and feasibility. Specimens were fabricated and experimentally evaluated to: (1) substantiate the capacity of the geometry changes to reduce operating stresses in the sprayed structure; and (2) define the abradability, erosion, thermal shock and physical property characteristic for the sprayed ceramic seal system. Thermal stress analysis was performed and correlated with thermal shock test results.

  7. Thermal Spraying Coatings Assisted by Laser Treatment

    SciTech Connect

    Fenineche, N. E.; Cherigui, M.

    2008-09-23

    Coatings produced by air plasma spraying (APS) are widely used to protect components against abrasive wear and corrosion. However, APS coatings contain porosities and the properties of these coatings may thereby be reduced. To improve these properties, various methods could be proposed, including post-laser irradiation [1-4]. Firstly, PROTAL process (thermal spraying assisted by laser) has been developed as a palliative technique to degreasing and grit-blasting prior to thermal spraying. Secondly, thermal spray coatings are densified and remelted using Laser treatment. In this study, a review of microstructure coatings prepared by laser-assisted air plasma spraying will be presented. Mechanical and magnetic properties will be evaluated in relation to changes in the coating microstructure and the properties of such coatings will be compared with those of as-sprayed APS coatings.

  8. Thermal Spray Applications in Electronics and Sensors: Past, Present, and Future

    NASA Astrophysics Data System (ADS)

    Sampath, Sanjay

    2010-09-01

    Thermal spray has enjoyed unprecedented growth and has emerged as an innovative and multifaceted deposition technology. Thermal spray coatings are crucial to the enhanced utilization of various engineering systems. Industries, in recognition of thermal spray's versatility and economics, have introduced it into manufacturing environments. The majority of modern thermal spray applications are "passive" protective coatings, and they rarely perform an electronic function. The ability to consolidate dissimilar material multilayers without substrate thermal loading has long been considered a virtue for thick-film electronics. However, the complexity of understanding/controlling materials functions especially those resulting from rapid solidification and layered assemblage has stymied expansion into electronics. That situation is changing: enhancements in process/material science are allowing reconsideration for novel electronic/sensor devices. This review critically examines past efforts in terms of materials functionality from a device perspective, along with ongoing/future concepts addressing the aforementioned deficiencies. The analysis points to intriguing future possibilities for thermal spray technology in the world of thick-film sensors.

  9. Experimental study of the effects of lithium coated plasma facing components on energy confinement time in the CDX-U device

    NASA Astrophysics Data System (ADS)

    Spaleta, Jeffrey Dario

    Experimentally constrained equilibrium reconstructions are an important analysis tool used to understand the physics of magnetically confined plasmas. This thesis describes the first ever calculations of equilibrium reconstructions for spherical tokamak plasmas in the presence of lithium coated plasma facing components (PFC's) in the Current Drive eXperiment - Upgrade (CDX-U) device. Equilibria were calculated using a modified version of the Equilibrium and Stability Code (ESC), and were constrained by measurements made from a collection of magnetic field diagnostics. The ESC was modified to incorporate the first ever implementation of a novel response function technique for magnetic field diagnostic calibration. The technique is well suited for situations where the assumption of toroidal symmetry of the magnetic field is invalid, or when wall eddy currents are too large to neglect. Also included is a detailed discussion of the calculation of energy confinement time from power balance arguments, using parameters obtained from equilibrium reconstructions. The energy confinement time, as derived from plasma equilibria, was as large as 6 milliseconds for plasmas in the presence of both solid and liquid lithium PFC's. This represents a significant improvement over baseline plasmas, which typically had energy confinement times of 1 millisecond or less. The energy confinement for plasmas with lithium PFC's also showed an improvement over that expected from the ITER98y1 confinement scaling, which is derived from a database of earlier tokamak results. The improvement in confinement over this scaling correlates with the observed increase in density "pump-out", which is indicative of low wall-recycling. Traditionally, plasma fueling has been dominated by wall-recycling, with 90% or more of the fuel coming from recycling sources instead of externally controlled means, such as gas puffing or pellet injection. Previous lithium wall coating experiments on the Tokamak Fusion Test

  10. Spray combustion model improvement study, 1

    NASA Technical Reports Server (NTRS)

    Chen, C. P.; Kim, Y. M.; Shang, H. M.

    1993-01-01

    This study involves the development of numerical and physical modeling in spray combustion. These modeling efforts are mainly motivated to improve the physical submodels of turbulence, combustion, atomization, dense spray effects, and group vaporization. The present mathematical formulation can be easily implemented in any time-marching multiple pressure correction methodologies such as MAST code. A sequence of validation cases includes the nonevaporating, evaporating and_burnin dense_sprays.

  11. Plasma sprayed ceria-containing interlayer

    DOEpatents

    Schmidt, Douglas S.; Folser, George R.

    2006-01-10

    A plasma sprayed ceria-containing interlayer is provided. The interlayer has particular application in connection with a solid oxide fuel cell used within a power generation system. The fuel cell advantageously comprises an air electrode, a plasma sprayed interlayer disposed on at least a portion of the air electrode, a plasma sprayed electrolyte disposed on at least a portion of the interlayer, and a fuel electrode applied on at least a portion of the electrolyte.

  12. Development of spray coated cathodes for RITS-6.

    SciTech Connect

    Simpson, Sean; Leckbee, Joshua J.; Miller, Stephen Samuel

    2013-09-01

    This report documents work conducted in FY13 to conduct a feasibility study on thermal spray coated cathodes to be used in the RITS-6 accelerator in an attempt to improve surface uniformity and repeatability. Currently, the cathodes are coated with colloidal silver by means of painting by hand. It is believed that improving the cathode coating process could simplify experimental setup and improve flash x-ray radiographic performance. This report documents the experimental setup and summarizes the results of our feasibility study. Lastly, it describes the path forward and potential challenges that must be overcome in order to improve the process for creating uniform and repeatable silver coatings for cathodes.

  13. Modeling Multi-Arc Spraying Systems

    NASA Astrophysics Data System (ADS)

    Bobzin, K.; Öte, M.

    2016-06-01

    The use of plasma as energy source in thermal spraying enables among others the processing of feed stock materials with very high melting temperatures as coating materials. New generation multi-arc plasma spraying systems are widely spread and promise several advantages in comparison to the conventional single-arc systems. Numerical modeling of multi-arc plasma spraying offers the possibility to increase the understanding about this process. This study focuses on the numerical modeling of three-cathode spraying systems, introducing the recent activities in this field and discussing the numerical aspects which influence the prediction power of the models.

  14. Dynamic characteristics of pulsed supersonic fuel sprays

    NASA Astrophysics Data System (ADS)

    Pianthong, K.; Matthujak, A.; Takayama, K.; Milton, B. E.; Behnia, M.

    2008-06-01

    This paper describes the dynamic characteristics of pulsed, supersonic liquid fuel sprays or jets injected into ambient air. Simple, single hole nozzles were employed with the nozzle sac geometries being varied. Different fuel types, diesel fuel, bio-diesel, kerosene, and gasoline were used to determine the effects of fuel properties on the spray characteristics. A vertical two-stage light gas gun was employed as a projectile launcher to provide a high velocity impact to produce the liquid jet. The injection pressure was around 0.88-1.24 GPa in all cases. The pulsed, supersonic fuel sprays were visualized by using a high-speed video camera and shadowgraph method. The spray tip penetration and velocity attenuation and other characteristics were examined and are described here. An instantaneous spray tip velocity of 1,542 m/s (Mach number 4.52) was obtained. However, this spray tip velocity can be sustained for only a very short period (a few microseconds). It then attenuates very quickly. The phenomenon of multiple high frequency spray pulses generated by a single shot impact and the changed in the angle of the shock structure during the spray flight, which had already been observed in previous studies, is again noted. Multiple shock waves from the conical nozzle spray were also clearly captured.

  15. Spray drift reduction evaluations of spray nozzles using a standardized testing protocol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The development and testing of drift reduction technologies has come to the forefront of application research in the past few years in the United States. Drift reduction technologies (DRTs) can be spray nozzles, sprayer modifications, spray delivery assistance, spray property modifiers (adjuvants),...

  16. Experimental research in the use of electrets in measuring effluents from rocket exhaust and a review of standard air quality measuring devices

    NASA Technical Reports Server (NTRS)

    Susko, M.

    1976-01-01

    Seven standard types of measuring devices used to obtain the chemical composition of rocket exhaust effluents were discussed. The electrets, a new measuring device, are investigated and compared with established measuring techniques. The preliminary results obtained show that electrets have multipollutant measuring capabilities, simplicity of deployment, speed of assessment or analysis, and may be an important and valuable tool in measuring pollutants from space vehicle rocket exhaust.

  17. Characteristics of vaporizing cryogenic sprays for rocket combustion modeling

    SciTech Connect

    Ingebo, R.D.

    1994-12-31

    Experimental measurements of the volume-median drop diameter, D{sub v.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, LN{sub 2}, jets in high-velocity gasflows of helium argon and gaseous nitrogen, GN{sub 2}. Also, in order to determine the effect of atomizing-gas temperature on specific surface areas of LN{sub 2} sprays, drop size measurements were made at gas temperatures of 111 and 293 K.

  18. Shock Interaction with Substrate in a Shock Induced Spray Process

    NASA Astrophysics Data System (ADS)

    Mrozinski, Kevin

    To further the knowledge of the Shock Induced Spray Process (SISP), an experimental apparatus which simulates Centerline's Waverider thermal spray gun was created which uses an unsteady flow to propel solid particles onto a substrate by the use of a shock wave to produce a coating. Experiments were conducted at a variety of operating supply pressures, firing frequencies, and stand off distances. A qualitative analysis was done using a custom Schlieren system along with a high speed camera. Insight into the flow behaviour in the SISP was established with the definition of six distinct phases. The formation of a bow shock, which is known to be detrimental to the SISP operation, is shown to be more prominent in the cases with higher supply pressure and close proximity of the apparatus exit to the substrate than with changes in firing frequency.

  19. A methodology for experimentally based determination of gap shrinkage and effective lifetimes in the emitter and base of p-n junction solar cells and other p-n junction devices

    NASA Technical Reports Server (NTRS)

    Lindholm, F. A.; Neugroschel, A.; Sah, C.-T.; Godlewski, M. P.; Brandhorst, H. W., Jr.

    1977-01-01

    An experimentally based methodology that determines the effective gap shrinkage and lifetime in the emitter of a p-n junction solar cell is described which provides an experimental means for assessing the importance of gap shrinkage relative to that of large recombination rates in the highly doped emitter. The base lifetime is also determined. The methodology pertains to a solar cell after the junction is formed, so that each material parameter determined includes the effects of the processing used in junction fabrication. The methodology consists of strategy and procedures for designing experiments and interpreting data consistently with the physical mechanisms governing device behavior. This careful linking to the device physics uncover the material parameters concealed in the data. To illustrate the procedures, they are applied to an n(+)-p solar cell having substrate resistivity of about 0.1 ohm-cm.

  20. Time variation in the reaction-zone structure of two-phase spray detonations.

    NASA Technical Reports Server (NTRS)

    Pierce, T. H.; Nicholls, J. A.

    1973-01-01

    A detailed theoretical analysis of the time-varying detonation structure in a monodisperse spray is presented. The theory identifies experimentally observed reaction-zone overpressures as deriving from blast waves formed therein by the explosive ignition of the spray droplets, and follows in time the motion, change in strength, and interactions of these blast waves with one another, and with the leading shock. The results are compared with experimental data by modeling the motion of a finite-size circular pressure transducer through the theoretical data field in an x-t space.

  1. Ultrasonically Sprayed and Inkjet Printed Thin Film Electrodes for Organic Solar Cells

    SciTech Connect

    Steirer, K. X.; Berry, J. J.; Reese, M. O.; van Hest, M. F. A. M.; Miedaner, A.; Liberatore, M. W.; Collins, R. T.; Ginley, D. S.

    2009-01-01

    Thin film pi-conjugated poly(3,4ethylenedioxythiophene): poly(styrenesulphonate) (PEDOT:PSS) as a hole transport layer on indium tin oxide is a key element in some of the most efficient organic photovoltaic and light emitting devices to date. Films are typically deposited by spincoating, which is not readily scalable. In this paper we investigate the critical parameters for both inkjet and ultrasonic spray deposition of PEDOT:PSS thin films on commercial indium tin oxide as a potentially scalable approach to contact formation. Inkjet parameters investigated include drop spacing and substrate temperature. Ultrasonic spray coating parameters investigated include substrate temperature and solution flow rate. We also show that the ink viscosity has a Newtonian character, making it well suited for inkjet printing. Films were characterized via optical profilometry, sheet resistance and atomic force microscopy. Optimized inkjet printed and ultrasonic sprayed PEDOT:PSS films were then compared to spincast layers in a prototypical bulk heterojunction photovoltaic device employing a poly(3-hexylthiophene) and [6,6]-PCBM (6,6-phenylC61-butyric acid-methyl ester) blend as the absorber. Practically all three approaches produced devices of comparable efficiency. Efficiencies were 3.6%, 3.5% and 3.3% for spin, spray and inkjet depositions respectively.

  2. Spray cooling simulation implementing time scale analysis and the Monte Carlo method

    NASA Astrophysics Data System (ADS)

    Kreitzer, Paul Joseph

    Spray cooling research is advancing the field of heat transfer and heat rejection in high power electronics. Smaller and more capable electronics packages are producing higher amounts of waste heat, along with smaller external surface areas, and the use of active cooling is becoming a necessity. Spray cooling has shown extremely high levels of heat rejection, of up to 1000 W/cm 2 using water. Simulations of spray cooling are becoming more realistic, but this comes at a price. A previous researcher has used CFD to successfully model a single 3D droplet impact into a liquid film using the level set method. However, the complicated multiphysics occurring during spray impingement and surface interactions increases computation time to more than 30 days. Parallel processing on a 32 processor system has reduced this time tremendously, but still requires more than a day. The present work uses experimental and computational results in addition to numerical correlations representing the physics occurring on a heated impingement surface. The current model represents the spray behavior of a Spraying Systems FullJet 1/8-g spray nozzle. Typical spray characteristics are indicated as follows: flow rate of 1.05x10-5 m3/s, normal droplet velocity of 12 m/s, droplet Sauter mean diameter of 48 microm, and heat flux values ranging from approximately 50--100 W/cm2 . This produces non-dimensional numbers of: We 300--1350, Re 750--3500, Oh 0.01--0.025. Numerical and experimental correlations have been identified representing crater formation, splashing, film thickness, droplet size, and spatial flux distributions. A combination of these methods has resulted in a Monte Carlo spray impingement simulation model capable of simulating hundreds of thousands of droplet impingements or approximately one millisecond. A random sequence of droplet impingement locations and diameters is generated, with the proper radial spatial distribution and diameter distribution. Hence the impingement, lifetime

  3. Preparation and characterization of microparticles of piroxicam by spray drying and spray chilling methods

    PubMed Central

    Dixit, M.; Kini, A.G.; Kulkarni, P.K.

    2010-01-01

    Piroxicam, an anti-inflammatory drug, exhibits poor water solubility and flow properties, poor dissolution and poor wetting. Consequently, the aim of this study was to improve the dissolution of piroxicam. Microparticles containing piroxicam were produced by spray drying, using isopropyl alcohol and water in the ratio of 40:60 v/v as solvent system, and spray chilling technology by melting the drug and chilling it with a pneumatic nozzle to enhance dissolution rate. The prepared formulations were evaluated for in vitro dissolution and solubility. The prepared drug particles were characterized by scanning electron microscopy (SEM), differential scanning calorimeter, X-ray diffraction and Fourier transform infrared spectroscopy. Dissolution profile of the spray dried microparticles was compared with spray-chilled microparticles, pure and recrystallized samples. Spray dried microparticles and spray chilled microparticles exhibited decreased crystallinity and improved micromeritic properties. The dissolution of the spray dried microparticle and spray chilled particles were improved compared with recrystallized and pure sample of piroxicam. Consequently, it was believed that spray drying of piroxicam is a useful tool to improve dissolution but not in case of spray chilling. This may be due to the degradation of drug or variations in the resonance structure or could be due to minor distortion of bond angles. Hence, this spray drying technique can be used for formulation of tablets of piroxicam by direct compression with directly compressible tablet excipients. PMID:21589797

  4. Experimental study of impurity screening in the edge ergodic layer of the Large Helical Device using carbon emissions of CIII to CVI

    NASA Astrophysics Data System (ADS)

    Chowdhuri, Malay Bikas; Morita, Shigeru; Kobayashi, Masahiro; Goto, Motoshi; Zhou, Hangyu; Masuzaki, Suguru; Morisaki, Tomohiro; Narihara, Kazumichi; Yamada, Ichihiro; Feng, Yuehe

    2009-06-01

    Four resonance transitions of CIII (977.03 Å:2 s2 S10-2s2pP11), CIV (1550 Å:2s S2-2p P2), CV (40.27 Å:1s2 S10-1s2pP11), and CVI (33.73 Å:1s S2-2p P2) have been observed in vacuum ultraviolet and extreme ultraviolet regions to study the edge carbon impurity transport in the Large Helical Device ergodic layer. Here, CIII and CIV indicate the carbon influx at the outside boundary of the ergodic layer and CV and CVI indicate the ions in higher ionization stages, which have already experienced the transport in the ergodic layer. The intensity ratio of CV+CVI to CIII+CIV, therefore, represents the degree of impurity screening, which has been analyzed with different edge plasma parameters and ergodic magnetic field structures. The ratio decreases by two orders of magnitude with an increase in electron density ne in the range of 1-8×1019 m-3. The CV and CVI emissions tend to decrease with ne, whereas the CIII and CIV emissions monotonically increase with ne. The result suggests an enhancement of the impurity screening in the higher ne range due to the increasing ion-impurity collision frequency (νΖi≡1/τs=3.4×104 s-1 at ne=2×1019 m-3 and 1.0×105 s-1 at 6×1019 m-3 for CV). The friction force parallel to the magnetic fields plays an important role in the edge impurity transport within the ergodic layer. When the ergodic layer structure is thicker, the ratio systematically decreases mainly due to a reduction in CV+CVI emissions. The ratio is also studied by changing the radial position of an externally supplied m /n=1/1 island. When the island is positioned in the ergodic layer, the ratio indicates a remarkable change, i.e., reduction in CV+CVI and increase in CIII+CIV. These experiments demonstrate that the modification of the ergodic magnetic field structure makes a clear change to the edge impurity transport. When the background ion species is changed from hydrogen to helium, the ratio is clearly reduced, at least at ne≤4×1019 m-3, suggesting the

  5. Experiment and numerical simulation of heat and mass transfer during a spray freeze-drying process of ovalbumin in a tray

    NASA Astrophysics Data System (ADS)

    Song, Chi-Sung; Yeom, Geum-Su

    2009-11-01

    Spray freeze-drying is a promising technology for producing high-quality porous particles primarily for pharmaceutical uses. The advantages of freeze-drying in the production of pharmaceuticals and biomedical products, such as minimization of thermal and chemical degradation, retention of volatile components, preservation of high porosity, and a very low content of residual water after drying, are mostly retained in spray freeze-drying. In this study, we performed spray freeze-drying of a 3% (w/w) chicken egg ovalbumin solution in a tray with a batch-type spray freeze-dryer that we developed. The physical characteristics of the spray freeze-dried particles were qualitatively evaluated by means of scanning electron microscopy. The freeze-drying behavior of spray-frozen particles was experimentally investigated by measuring the histories of product temperatures and numerically studied by developing an analysis model based on the finite volume method in a fixed grid system.

  6. Spray Deflector For Water-Jet Machining

    NASA Technical Reports Server (NTRS)

    Cawthon, Michael A.

    1989-01-01

    Disk on water-jet-machining nozzle protects nozzle and parts behind it from erosion by deflected spray. Consists of stainless-steel backing with neoprene facing deflecting spray so it does not reach nut or other vital parts of water-jet apparatus.

  7. Spray Gun With Constant Mixing Ratio

    NASA Technical Reports Server (NTRS)

    Simpson, William G.

    1987-01-01

    Conceptual mechanism mounted in handle of spray gun maintains constant ratio between volumetric flow rates in two channels leading to spray head. With mechanism, possible to keep flow ratio near 1:1 (or another desired ratio) over range of temperatures, orifice or channel sizes, or clogging conditions.

  8. Spray structure of a pressure-swirl atomizer for combustion applications

    NASA Astrophysics Data System (ADS)

    Durdina, Lukas; Jedelsky, Jan; Jicha, Miroslav

    2012-04-01

    In the present work, global as well as spatially resolved parameters of a spray produced by a pressure-swirl atomizer are obtained. Small pressure-swirl atomizer for aircraft combustion chambers was run on a newly designed test bench with Jet A-1 kerosene type aviation fuel. The atomizer was tested in four regimes based on typical operation conditions of the engine. Spray characteristics were studied using two optical measurement systems, Particle Image velocimetry (PIV) and Phase-Doppler Particle Analyzer (P/DPA). The results obtained with P/DPA include information about Sauter Mean Diameter of droplets and spray velocity profiles in one plane perpendicular to the spray axis. Velocity magnitudes of droplets in an axial section of the spray were obtained using PIV. The experimental outputs also show a good confirmation of velocity profiles obtained with both instruments in the test plane. These data together will elucidate impact of the spray quality on the whole combustion process, its efficiency and exhaust gas emissions.

  9. Comparison of Global Sizing Velocimetry and Phase Doppler Anemometry measurements of alternative jet fuel sprays

    NASA Astrophysics Data System (ADS)

    Sadr, Reza; Kannaiyan, Kumaran

    2013-11-01

    Atomization plays a crucial precursor role in liquid fuel combustion that directly affects the evaporation, mixing, and emission levels. Laser diagnostic techniques are often used to study the spray characteristics of liquid fuels. The objective of this work is to compare the spray measurements of Gas-to Liquid (GTL) jet fuels obtained using Global Sizing Velocimetry (GSV) and Phase Doppler Anemometry (PDA) techniques at global and local levels, respectively. The chemical and physical properties of GTL fuels are different from conventional jet fuels, owing to the difference in their production methodology. In this work, the experimental facility, the measurement techniques, and spray characteristics of two different GTL fuels are discussed and compared with those of Jet A-1 fuel. Results clearly demonstrate that although the global measurement gives an overall picture of the spray, fine details are obtained only through local measurements and complement in gaining more inferences into the spray characteristics. The results also show a close similarity in spray characteristics between GTL and Jet A-1 fuels. Funded by Qatar Science and Technology Park.

  10. Ionization Suppression and Recovery in Direct Biofluid Analysis Using Paper Spray Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Vega, Carolina; Spence, Corina; Zhang, Chengsen; Bills, Brandon J.; Manicke, Nicholas E.

    2016-04-01

    Paper spray mass spectrometry is a method for the direct analysis of biofluid samples in which extraction of analytes from dried biofluid spots and electrospray ionization occur from the paper on which the dried sample is stored. We examined matrix effects in the analysis of small molecule drugs from urine, plasma, and whole blood. The general method was to spike stable isotope labeled analogs of each analyte into the spray solvent, while the analyte itself was in the dried biofluid. Intensity of the labeled analog is proportional to ionization efficiency, whereas the ratio of the analyte intensity to the labeled analog in the spray solvent is proportional to recovery. Ion suppression and recovery were found to be compound- and matrix-dependent. Highest levels of ion suppression were obtained for poor ionizers (e.g., analytes lacking basic aliphatic amine groups) in urine and approached -90%. Ion suppression was much lower or even absent for good ionizers (analytes with aliphatic amines) in dried blood spots. Recovery was generally highest in urine and lowest in blood. We also examined the effect of two experimental parameters on ion suppression and recovery: the spray solvent and the sample position (how far away from the paper tip the dried sample was spotted). Finally, the change in ion suppression and analyte elution as a function of time was examined by carrying out a paper spray analysis of dried plasma spots for 5 min by continually replenishing the spray solvent.

  11. Development of a plasma sprayed ceramic gas path seal for high pressure turbine application

    NASA Technical Reports Server (NTRS)

    Shiembob, L. T.

    1978-01-01

    Development of the plasma sprayed graded, layered ZRO2/CoCrAlY seal system for gas turbine engine blade tip seal applications up to 1589 K (2400 F) surface temperature was continued. The effect of changing ZRO2/CoCrAlY ratios in the intermediate layers on thermal stresses was evaluated analytically with the goal of identifying the materials combinations which would minimize thermal stresses in the seal system. Three methods of inducing compressive residual stresses in the sprayed seal materials to offset tensile thermal stresses were analyzed. The most promising method, thermal prestraining, was selected based upon potential, feasibility and complexity considerations. The plasma spray equipment was modified to heat, control and monitor the substrate temperature during spraying. Specimens were fabricated and experimentally evaluated to: (1) substantiate the capability of the thermal prestrain method to develop compressive residual stresses in the sprayed structure and (2) define the effect of spraying on a heated substate on abradability, erosion and thermal shock characteristics of the seal system. Thermal stress analysis, including residual stresses and material properties variations, was performed and correlated with thermal shock test results. Seal system performance was assessed and recommendations for further development were made.

  12. Measurements of Flow Rate and Trajectory of Aircraft Tire-Generated Water Spray

    NASA Technical Reports Server (NTRS)

    Daugherty, Robert H.; Stubbs, Sandy M.

    1987-01-01

    An experimental investigation was conducted at the NASA Langley Research Center to measure the flow rate and trajectory of water spray generated by an aircraft tire operating on a flooded runway. Tests were conducted in the Hydrodynamics Research Facility and made use of a partial airframe and a nose tire from a general aviation aircraft. Nose tires from a commercial transport aircraft were also used. The effects of forward speed, tire load, and water depth on water spray patterns were evaluated by measuring the amount and location of water captured by an array of tubes mounted behind the test tire. Water ejected from the side of the tire footprint had the most significant potential for ingestion into engine inlets. A lateral wake created on the water surface by the rolling tire can dominate the shape of the spray pattern as the distance aft of the tire is increased. Forward speed increased flow rates and moved the spray pattern inboard. Increased tire load caused the spray to become less dense. Near the tire, increased water depths caused flow rates to increase. Tests using a fuselage and partial wing along with the nose gear showed that for certain configurations, wing aerodynamics can cause a concentration of spray above the wing.

  13. Breakup and coalescence characteristics of a hollow cone swirling spray

    NASA Astrophysics Data System (ADS)

    Saha, Abhishek; Lee, Joshua D.; Basu, Saptarshi; Kumar, Ranganathan

    2012-12-01

    This paper deals with an experimental study of the breakup characteristics of water emanating from hollow cone hydraulic injector nozzles induced by pressure-swirling. The experiments were conducted using two nozzles with different orifice diameters 0.3 mm and 0.5 mm and injection pressures (0.3-4 MPa) which correspond to Rep = 7000-26 000. Two types of laser diagnostic techniques were utilized: shadowgraph and phase Doppler particle anemometry for a complete study of the atomization process. Measurements that were made in the spray in both axial and radial directions indicate that both velocity and average droplet diameter profiles are highly dependent on the nozzle characteristics, Weber number and Reynolds number. The spatial variation of diameter and velocity arises principally due to primary breakup of liquid films and subsequent secondary breakup of large droplets due to aerodynamic shear. Downstream of the nozzle, coalescence of droplets due to collision was also found to be significant. Different types of liquid film breakup were considered and found to match well with the theory. Secondary breakup due to shear was also studied theoretically and compared to the experimental data. Coalescence probability at different axial and radial locations was computed to explain the experimental results. The spray is subdivided into three zones: near the nozzle, a zone consisting of film and ligament regime, where primary breakup and some secondary breakup take place; a second zone where the secondary breakup process continues, but weakens, and the centrifugal dispersion becomes dominant; and a third zone away from the spray where coalescence is dominant. Each regime has been analyzed in detail, characterized by timescale and Weber number and validated using experimental data.

  14. Combustion of liquid sprays at high pressures

    NASA Technical Reports Server (NTRS)

    Shearer, A. J.; Faeth, G. M.

    1977-01-01

    The combustion of pressure atomized fuel sprays in high pressure stagnant air was studied. Measurements were made of flame and spray boundaries at pressures in the range 0.1-9 MPa for methanol and n-pentane. At the higher test pressure levels, critical phenomena are important. The experiments are compared with theoretical predictions based on a locally homogeneous two-phase flow model. The theory correctly predicted the trends of the data, but underestimates flame and spray boundaries by 30-50 percent, indicating that slip is still important for the present experiments (Sauter mean diameters of 30 microns at atmospheric pressure under cold flow conditions). Since the sprays are shorter at high pressures, slip effects are still important even though the density ratio of the phases approach one another as the droplets heat up. The model indicates the presence of a region where condensed water is present within the spray and provides a convenient means of treating supercritical phenomena.

  15. Tapered plug foam spray apparatus

    NASA Technical Reports Server (NTRS)

    Allen, Peter B. (Inventor)

    1996-01-01

    A two-component foam spray gun is readily disassembled for cleaning. It includes a body (1) with reactant (12, 14) and purge gas (16) inlet ports. A moldable valve packing (32) inside the body has a tapered conical interior surface (142), and apertures which match the reactant ports. A valve/tip (40) has a conical outer surface (48) which mates with the valve packing (32). The valve/tip (40) is held in place by a moldable packing washer (34), held at non-constant pressure by a screw (36, 38). The interior of the valve/tip (40) houses a removable mixing chamber (50). The mixing chamber (50) has direct flow orifices (60) and an auxiliary flow path (58, 60) which ameliorate pressure surges. The spray gun can be disassembled for cleaning without disturbing the seal, by removing the valve/tip (40) to the rear, thereby breaking it free of the conical packing. Rotation of the valve/tip (40) relative to the body (1) shuts off the reactant flow, and starts the purge gas flow.

  16. Nanoparticle colloids as spray deposition precursors to CIGS photovoltaic materials

    NASA Astrophysics Data System (ADS)

    Schulz, Douglas L.; Curtis, Calvin J.; Flitton, Rebecca A.; Wiesner, Holm; Keane, James; Matson, Richard J.; Parilla, Philip A.; Noufi, Rommel; Ginley, David S.

    1997-02-01

    Cu-In-Ga-Se nanoparticle colloids have been used as precursors in the spray deposition of photovoltaic films. Precursor colloid was prepared by reaction of the metal iodides in pyridine with sodium selenide in methanol at reduced temperature according to one of two routes: synthesis of each of the component binary selenides (Type I) followed by physical mixing of the isolated particles; or a one-pot synthesis with all the metal iodides reacting together in one flask to form a mixed-metal Cu-In-Ga-Se colloid (Type II). The constituent nanoparticles in these colloids were analyzed by TEM and XRD and were determined to be amorphous as-synthesized. Crystalline phase formation of these nanoparticles was observed by XRD after a thermal treatment. These precursor colloids were sprayed onto Mo-coated glass substrates at elevated temperatures. The nanoparticle-derived Cu-In-Ga-Se films were characterized by SEM and XRD prior to being finished into CIGS solar cell devices according to standard NREL protocol. I-V characterization of these CIGS solar cells showed these devices are limited by a large series resistance.

  17. Numerical study of spray injection effects on the heat transfer and product yields of FCC riser reactors.

    SciTech Connect

    Chang, S. L.; Lottes, S. A.; Zhou, C. Q.; Bowman, B. J.; Petrick, M.; Energy Systems; Purdue Univ. at Calumet

    2001-06-01

    A three-phase reacting flow computational fluid dynamics (CFD) computer code was used to study the major effects of spray injection parameters on mixing, heat transfer, vaporization, and reaction product yields in fluidized catalytic cracking (FCC) riser reactors. The CFD code was validated using experimental or field data. A number of computations were performed with varied injection parameters, including injection velocity, injection angle, and droplet size. Local optimum operating windows for spray injection parameters were identified, and the sensitivity of local optima to variation in spray parameters was also investigated.

  18. Enhanced ingrowth of porous-coated CoCr implants plasma-sprayed with tricalcium phosphate.

    PubMed

    Chae, J C; Collier, J P; Mayor, M B; Surprenant, V A; Dauphinais, L A

    1992-01-01

    Tricalcium phosphate (TCP) is an osteo-conductive bioceramic which, when applied to a porous-coated prosthesis, may enhance osseous ingrowth and mechanical stability. TCP plasma-sprayed and unsprayed porous-coated tibial intramedullary rods were bilaterally implanted in seven adult rabbits. All rabbits were killed at 12 weeks. Pull-out tests were performed on 4 rabbits while all were evaluated histologically for osseous response and adverse tissue reaction. TCP-sprayed implants showed significantly greater osseous ingrowth in comparison to unsprayed implants. Neither implant type exhibited adverse tissue reactions. Average pull-out strengths were 69 lb for treated rods and 72 lb for controls (p greater than 0.05); quality of fit for all pull-out specimens except one was deemed poor. We conclude that plasma-sprayed TCP enhances osseous ingrowth into porous-coated devices. However, our data further suggest that enhanced ingrowth may not always lead to enhanced fixation.

  19. Spray forming -- Aluminum: Third annual report (Phase 2). Technical progress -- Summary

    SciTech Connect

    Kozarek, R.L.

    1998-04-20

    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 the technology, the Aluminum Company of America (Alcoa), under contract by the US Department of Energy, is investigating currently available state-of-the-art atomization devices to develop nozzle design concepts whose spray characteristics are tailored for continuous sheet production. This third technical progress report will summarize research and development work conducted during the period 1997 October through 1998 March. Included are the latest optimization work on the Alcoa III nozzle, results of spray forming runs with 6111 aluminum alloy and preliminary rolling trials of 6111 deposits.

  20. Early development drug formulation on a chip: fabrication of nanoparticles using a microfluidic spray dryer.

    PubMed

    Thiele, Julian; Windbergs, Maike; Abate, Adam R; Trebbin, Martin; Shum, Ho Cheung; Förster, Stephan; Weitz, David A

    2011-07-21

    Early development drug formulation is exacerbated by increasingly poor bioavailability of potential candidates. Prevention of attrition due to formulation problems necessitates physicochemical analysis and formulation studies at a very early stage during development, where the availability of a new substance is limited to small quantities, thus impeding extensive experiments. Miniaturization of common formulation processes is a strategy to overcome those limitations. We present a versatile technique for fabricating drug nanoformulations using a microfluidic spray dryer. Nanoparticles are formed by evaporative precipitation of the drug-loaded spray in air at room temperature. Using danazol as a model drug, amorphous nanoparticles of 20-60 nm in diameter are prepared with a narrow size distribution. We design the device with a geometry that allows the injection of two separate solvent streams, thus enabling co-spray drying of two substances for the production of drug co-precipitates with tailor-made composition for optimization of therapeutic efficiency. PMID:21617823

  1. The effects of diesel injector needle motion on spray structure.

    SciTech Connect

    Powell, C. F.; Kastengren, A. L.; Liu, Z.; Fezzaa, K.

    2011-01-01

    The internal structure of diesel fuel injectors is known to have a significant impact on the steady-state fuel distribution within the spray. However, little experimental or computational work has been performed on the dynamics of fuel injectors. Recent studies have shown that it is possible to measure the three-dimensional geometry of the injector nozzle, and to track changes in that geometry as the needle opens and closes in real time. This has enabled the dynamics of the injector to be compared with the dynamics of the spray, and allows computational fluid dynamics (CFD) simulations to use realistic time-dependent flow passage geometries. In this study, X-ray phase-enhanced imaging has been used to perform time-resolved imaging of the needle seat area in several common-rail diesel injection nozzles. The fuel distributions of the sprays emitted by these injectors were also studied with fast X-ray radiography. Correlations between eccentric motions of the injector needle valve and oscillations in the fuel density as it emerges from the nozzle are examined. CFD modeling is used to interpret the effect of needle motion on fuel flow.

  2. Radiation-Spray Coupling for Realistic Flow Configurations

    NASA Technical Reports Server (NTRS)

    El-Asrag, Hossam; Iannetti, Anthony C.

    2011-01-01

    Three Large Eddy Simulations (LES) for a lean-direct injection (LDI) combustor are performed and compared. In addition to the cold flow simulation, the effect of radiation coupling with the multi-physics reactive flow is analyzed. The flame let progress variable approach is used as a subgrid combustion model combined with a stochastic subgrid model for spray atomization and an optically thin radiation model. For accurate chemistry modeling, a detailed Jet-A surrogate mechanism is utilized. To achieve realistic inflow, a simple recycling technique is performed at the inflow section upstream of the swirler. Good comparison is shown with the experimental data mean and root mean square profiles. The effect of combustion is found to change the shape and size of the central recirculation zone. Radiation is found to change the spray dynamics and atomization by changing the heat release distribution and the local temperature values impacting the evaporation process. The simulation with radiation modeling shows wider range of droplet size distribution by altering the evaporation rate. The current study proves the importance of radiation modeling for accurate prediction in realistic spray combustion configurations, even for low pressure systems.

  3. Steam chemical reactivity of plasma-sprayed beryllium

    SciTech Connect

    Anderl, R.A.; Pawelko, R.J.; Smolik, G.R.; Castro, R.G.

    1998-07-01

    Plasma-spraying with the potential for in-situ repair makes beryllium a primary candidate for plasma facing and structural components in experimental magnetic fusion machines. Deposits with good thermal conductivity and resistance to thermal cycling have been produced with low pressure plasma-spraying (LPPS). A concern during a potential accident with steam ingress is the amount of hydrogen produced by the reactions of steam with hot components. In this study the authors measure the reaction rates of various deposits produced by LPPS with steam from 350 C to above 1,000 C. They correlate these reaction rates with measurements of density, open porosity and BET surface areas. They find the reactivity to be largely dependent upon effective surface area. Promising results were obtained below 600 C from a 94% theoretical dense (TD) deposit with a BET specific surface area of 0.085 m{sup 2}/g. Although reaction rates were higher than those for dense consolidated beryllium they were substantially lower, i.e., about two orders of magnitude, than those obtained from previously tested lower density plasma-sprayed deposits.

  4. Zero Volt Paper Spray Ionization and Its Mechanism.

    PubMed

    Wleklinski, Michael; Li, Yafeng; Bag, Soumabha; Sarkar, Depanjan; Narayanan, Rahul; Pradeep, T; Cooks, R Graham

    2015-07-01

    The analytical performance and a suggested mechanism for zero volt paper spray using chromatography paper are presented. A spray is generated by the action of the pneumatic force of the mass spectrometer (MS) vacuum at the inlet. Positive and negative ion signals are observed, and comparisons are made with standard kV paper spray (PS) ionization and nanoelectrospray ionization (nESI). While the range of analytes to which zero volt PS is applicable is very similar to kV PS and nESI, differences in the mass spectra of mixtures are interpreted in terms of the more significant effects of analyte surface activity in the gentler zero volt experiment than in the other methods due to the significantly lower charge. The signal intensity of zero volt PS is also lower than in the other methods. A Monte Carlo simulation based on statistical fluctuation of positive and negative ions in solution has been implemented to explain the production of ions from initially uncharged droplets. Uncharged droplets first break up due to aerodynamics forces until they are in the 2-4 μm size range and then undergo Coulombic fission. A model involving statistical charge fluctuations in both phases predicts detection limits similar to those observed experimentally and explains the effects of binary mixture components on relative ionization efficiencies. The proposed mechanism may also play a role in ionization by other voltage-free methods. PMID:26024306

  5. Thermal spray and cold spray analysis of density, porosity, and tensile Specimens for use with LIGA applications

    SciTech Connect

    DECKER,MERLIN K.; SMITH,MARK F.

    2000-02-01

    This analysis provides a preliminary investigation into using Twin-Wire Arc Thermal Spray and Cold Spray as material deposition processes for LIGA applications. These spray material processes were studied to make an initial determination of their potential as alternatives to producing mechanical parts via the electroplating process. Three materials, UltraMachinable{reg_sign} Stainless Steel, BondArc{reg_sign}, and aluminum, were sprayed using Thermal Spray. Only aluminum was sprayed using the Cold Spray process. Following the spray procedure, the test specimens were released from a copper mold and then tested. Three tests, density, tensile strength, and porosity, were performed on the specimens to determine the spray effect on material properties. Twin-Wire Arc Thermal Spray did not demonstrate adequate deposition properties and does not appear to be a good process candidate for LIGA. However, Cold Spray yielded better density results and warrants further investigation to analyze the minimum feature size produced by the process.

  6. Passive Wireless Hermetic Environment Monitoring System for Spray Painting Workshop.

    PubMed

    Wang, Lifeng; Ma, Jingjing; Huang, Yan; Tang, Dan; Huang, Qing-An

    2016-08-01

    Passive wireless sensors have the advantages of operating without a power supply and remote sensing capability. Hence, they are very suitable for some harsh environments, such as hermetic environments, rotating parts, or very high temperature environments. The spray painting workshop is such a harsh environment, containing a large amount of flammable paint mist and organic gas. Aiming at this special environment of spray painting workshop, a passive wireless hermetic environment monitoring system was designed, fabricated, and demonstrated. The proposed system is composed of a transponder and a reader, and the circuit design of each part is given in detail in this paper. The power and the data transmission between the transponder and the reader are realized by the inductive coupling mechanism. Utilizing the back scatter modulation and channel multiplexing, the frequency signals generated by three different environmental sensors-together with their interfaces in the transponder-are wirelessly read out by the reader. Because of the harsh environment of the spray painting room, the package of the monitoring system is quite important. Three different kinds of filter films for the system package were compared. The experimental results show that the composite filter film aluminum anodic oxide/polytetrafluoroethylene (AAO/PTFE) has the best performance. After fabrication, the measured temperature, humidity, and pressure sensitivities were measured and found to be 180 Hz/°C in the range of 0~60 °C, 100 Hz/%RH in the range of 15~95 %RH, and 42 Hz/hPa in the range of 600~1100 hPa, respectively. Additionally, the remote sensing distance of the monitoring system reaches 4 cm. Finally, the passive wireless hermetic environment monitoring system was installed on the glass wall of the spray painting workshop and was successfully demonstrated.

  7. Passive Wireless Hermetic Environment Monitoring System for Spray Painting Workshop

    PubMed Central

    Wang, Lifeng; Ma, Jingjing; Huang, Yan; Tang, Dan; Huang, Qing-An

    2016-01-01

    Passive wireless sensors have the advantages of operating without a power supply and remote sensing capability. Hence, they are very suitable for some harsh environments, such as hermetic environments, rotating parts, or very high temperature environments. The spray painting workshop is such a harsh environment, containing a large amount of flammable paint mist and organic gas. Aiming at this special environment of spray painting workshop, a passive wireless hermetic environment monitoring system was designed, fabricated, and demonstrated. The proposed system is composed of a transponder and a reader, and the circuit design of each part is given in detail in this paper. The power and the data transmission between the transponder and the reader are realized by the inductive coupling mechanism. Utilizing the back scatter modulation and channel multiplexing, the frequency signals generated by three different environmental sensors—together with their interfaces in the transponder—are wirelessly read out by the reader. Because of the harsh environment of the spray painting room, the package of the monitoring system is quite important. Three different kinds of filter films for the system package were compared. The experimental results show that the composite filter film aluminum anodic oxide/polytetrafluoroethylene (AAO/PTFE) has the best performance. After fabrication, the measured temperature, humidity, and pressure sensitivities were measured and found to be 180 Hz/°C in the range of 0~60 °C, 100 Hz/%RH in the range of 15~95 %RH, and 42 Hz/hPa in the range of 600~1100 hPa, respectively. Additionally, the remote sensing distance of the monitoring system reaches 4 cm. Finally, the passive wireless hermetic environment monitoring system was installed on the glass wall of the spray painting workshop and was successfully demonstrated. PMID:27490546

  8. Passive Wireless Hermetic Environment Monitoring System for Spray Painting Workshop.

    PubMed

    Wang, Lifeng; Ma, Jingjing; Huang, Yan; Tang, Dan; Huang, Qing-An

    2016-01-01

    Passive wireless sensors have the advantages of operating without a power supply and remote sensing capability. Hence, they are very suitable for some harsh environments, such as hermetic environments, rotating parts, or very high temperature environments. The spray painting workshop is such a harsh environment, containing a large amount of flammable paint mist and organic gas. Aiming at this special environment of spray painting workshop, a passive wireless hermetic environment monitoring system was designed, fabricated, and demonstrated. The proposed system is composed of a transponder and a reader, and the circuit design of each part is given in detail in this paper. The power and the data transmission between the transponder and the reader are realized by the inductive coupling mechanism. Utilizing the back scatter modulation and channel multiplexing, the frequency signals generated by three different environmental sensors-together with their interfaces in the transponder-are wirelessly read out by the reader. Because of the harsh environment of the spray painting room, the package of the monitoring system is quite important. Three different kinds of filter films for the system package were compared. The experimental results show that the composite filter film aluminum anodic oxide/polytetrafluoroethylene (AAO/PTFE) has the best performance. After fabrication, the measured temperature, humidity, and pressure sensitivities were measured and found to be 180 Hz/°C in the range of 0~60 °C, 100 Hz/%RH in the range of 15~95 %RH, and 42 Hz/hPa in the range of 600~1100 hPa, respectively. Additionally, the remote sensing distance of the monitoring system reaches 4 cm. Finally, the passive wireless hermetic environment monitoring system was installed on the glass wall of the spray painting workshop and was successfully demonstrated. PMID:27490546

  9. The “Skull Flap” a new conceived device for decompressive craniectomy experimental study on dogs to evaluate the safety and efficacy in reducing intracranial pressure and subsequent impact on brain perfusion

    PubMed Central

    Salvatore, Chibbaro; Fabrice, Vallee; Marco, Marsella; Leonardo, Tigan; Thomas, Lilin; Benoit, Lecuelle; Bernard, George; Pierre, Kehrli; Eric, Vicaut; Paolo, Diemidio

    2013-01-01

    Background: Decompressive craniectomy (DC) is a procedure performed increasingly often in current neurosurgical practice. Significant perioperative morbidity may be associated to this procedure because of the large skull defect; also, later closure of the skull defect (cranioplasty) may be associated to post-operative morbidity as much as any other reconstructive operation. The authors present a newly conceived/developed device: The “Skull Flap” (SF). This system, placed at the time of the craniectomy, offers the possibility to provide cranial reconstruction sparing patients a second operation. In other words, DC and cranioplasty essentially take place at the same time and in addition, patients retain their own bone flap. The current study conducted on animal models, represents the logical continuation of a prior recent study, realized on cadaver specimens, to assess the efficacy and safety of this recently developed device. Materials and Methods: This is an experimental pilot study on dogs to assess both safety and efficacy of the SF device. Two groups of experimental raised intracranial pressure animal models underwent DC; in the first group of dogs, the bone flap was left in raised position above the skull defect using the SF device; on the second group the flap was discarded. All dogs underwent transcranial Doppler (TCD) to assess brain perfusion. Head computed tomography (CT) scan to determine flap position was also obtained in the group in which the SF device was placed. Results: SF has proved to be a strong fixation device that allows satisfactory brain decompression by keeping the bone flap elevated from the swollen brain; later on, the SF allows cranial reconstruction in a simple way without requiring a second staged operation. In addition, it is relevant to note that brain perfusion was measured and found to be better in the group receiving the SF (while the flap being in a raised as well as in its natural position) comparing to the other group

  10. Numerical simulation of emulsified fuel spray combustion with puffing and micro-explosion

    SciTech Connect

    Watanabe, Hirotatsu; Matsushita, Yohsuke; Aoki, Hideyuki; Miura, Takatoshi

    2010-05-15

    The purpose of this study was to develop numerical simulation of spray combustion of emulsified fuel with considering puffing and micro-explosion. First, a mathematical model for puffing was proposed. In the proposed puffing model, the rate of mass change of a droplet during puffing was expressed by the evaporation rate of dispersed water and the mass change rate due to fine droplets spouted from the droplet surface. The mass change rate due to fine droplets was related to the evaporation rate of the dispersed water and each liquid content. This model had only one experimental parameter. The essential feature of this model was that it was simple to apply to numerical simulation of spray combustion. First, the validity of the proposed puffing model was investigated with the experimental results for a single droplet. The calculated results for a single droplet with the experimental parameter varying from 5.0 to 10 were in good agreement with the experimental results. Moreover, numerical simulation of spray combustion of emulsified fuel was carried out. The occurrence of puffing and micro-explosion was determined by the inner droplet temperature. When micro-explosion occurred, a droplet changed to vapor rapidly. When the proposed puffing model was used in numerical simulation of spray combustion, the experimental parameter in the puffing model was determined for each droplet by random numbers within the range 5.0-10. The calculated results of spray combustion of emulsified fuel without considering puffing or micro-explosions were different from the experimental results even where combustion reactions were almost terminated. Meanwhile, the calculated results when considering puffing and micro-explosions were in good agreement with experimental results at the same location. (author)

  11. High Anatase Rate Titanium Dioxide Coating Deposition by Low Power Microwave Plasma Spray

    NASA Astrophysics Data System (ADS)

    Redza, Ahmad; Kondo, Toshiki; Yasui, Toshiaki; Fukumoto, Masahiro

    2016-02-01

    Titanium dioxide is a promising photocatalyst material because of the magnificent properties of this material where it is able to remove the air pollution substance and the deodorizing function. Generally, the deposition method of a titanium dioxide coating is carried out by an organic system binder but the powerful photocatalytic reaction will degrades the binder. Therefore, thermal spray is considered to be the alternative method but this method will induce crystallization transformation of titanium dioxide from anatase phase with high photocatalytic activity to rutile phase with low photocatalyst which caused by high heat input. Since our microwave plasma spraying device is operable at low power comparing with conventional high power plasma spray, the reduce effect of the heat input onto the particles at the time of spraying can be achieved and coating deposition with high rate of anatase phase is expected. Therefore, in this research, the coating deposition by controlling the heat input into the spray particle which can be resulted in high rate of anatase phase with high photocatalytic activity was conducted. By controlled condition, coating with optimum anatase rate of 83% is able to be fabricated by this method.

  12. Testing of a Spray-bar Thermodynamic Vent System in Liquid Nitrogen

    NASA Technical Reports Server (NTRS)

    Flachbart, R. H.; Hastings, L. J.; Hedayat, A.; Nelson, S. L.; Tucker, S. P.

    2005-01-01

    To support development of a microgravity pressure control capability for liquid oxygen, thermodynamic vent system (TVS) testing was conducted at Marshall Space Flight Center (MSFC) using liquid nitrogen (LN2) as a LOX simulant. The spray bar TVS hardware used was originally designed by the Boeing Company for testing in liquid hydrogen (LH2). With this concept, a small portion of the tank fluid is passed through a Joule-Thomson (J-T) device, and then through a longitudinal spray bar mixed-heat exchanger in order to cool the bulk fluid. To accommodate the larger mass flow rates associated with LN2, the TVS hardware was modified by replacing the recirculation pump with an LN2 compatible pump and replacing the J-T valve. The primary advantage of the spray-bar configuration is that tank pressure control can be achieved independent of liquid and vapor location, enhancing the applicability of ground test data to microgravity conditions. Performance testing revealed that the spray-bar TVS was effective in controlling tank pressure within a 6.89 kPa band for fill levels of 90%, 50%, and 25%. Tests were also conducted with gaseous helium (GHe) in the ullage. The TVS operated nominally with GHe in the ullage, with performance similar to the tests with gaseous nitrogen (GN2). Testing demonstrated that the spray-bar TVS design was flexible enough for use in two different propellants with minimal hardware modifications.

  13. Computational fluid dynamics analysis of a wire-feed, high-velocity oxygen-fuel (HVOF) thermal spray torch

    SciTech Connect

    Lopez, A.R.; Hassan, B.; Oberkampf, W.L.; Neiser, R.A.; Roemer, T.J.

    1996-09-01

    The fluid and particle dynamics of a High-Velocity Oxygen-Fuel Thermal Spray torch are analyzed using computational and experimental techniques. Three-dimensional Computational Fluid Dynamics (CFD) results are presented for a curved aircap used for coating interior surfaces such as engine cylinder bores. The device analyzed is similar to the Metco Diamond Jet Rotating Wire (DJRW) torch. The feed gases are injected through an axisymmetric nozzle into the curved aircap. Premixed propylene and oxygen are introduced from an annulus in the nozzle, while cooling air is injected between the nozzle and the interior wall of the aircap. The combustion process is modeled using a single-step finite-rate chemistry model with a total of 9 gas species which includes dissociation of combustion products. A continually-fed steel wire passes through the center of the nozzle and melting occurs at a conical tip near the exit of the aircap. Wire melting is simulated computationally by injecting liquid steel particles into the flow field near the tip of the wire. Experimental particle velocity measurements during wire feed were also taken using a Laser Two-Focus (L2F) velocimeter system. Flow fields inside and outside the aircap are presented and particle velocity predictions are compared with experimental measurements outside of the aircap.

  14. The structure of dilute combusting sprays

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    An experimental and theoretical study of drop processes in a turbulent flame is described. The experiments involved a monodisperse (105 and 180 micro m initial diameter) stream of methanol drops injected at the base of a turbulent methane-fueled diffusion flame burning in still air. The following measurements were made: mean and fluctuating phase velocities, mean drop number flux, drop-size distributions and mean gas-phase temperatures. Measurements were compared with predictions of two separated flow models: (1) deterministic separated flow, where drop-turbulence interactions are ignored; and (2) stochastic separated flow, where drop-turbulence interactions are considered using random-walk computations. The stochastic separated flow analysis yielded best agreement with measurements, since it provides for turbulent dispersion of drops which was important for present test conditions (and probably for most combusting sprays as well). Distinguishing the presence or absence of envelope flames around the drops, however, was relatively unimportant for present test conditions, since the drops spent most of their lifetime in fuel-rich regions of the flow where this distinction is irrelevant.

  15. LSPRAY-IV: A Lagrangian Spray Module

    NASA Technical Reports Server (NTRS)

    Raju, M. S.

    2012-01-01

    LSPRAY-IV is a Lagrangian spray solver developed for application with parallel computing and unstructured grids. It is designed to be massively parallel and could easily be coupled with any existing gas-phase flow and/or Monte Carlo Probability Density Function (PDF) solvers. The solver accommodates the use of an unstructured mesh with mixed elements of either triangular, quadrilateral, and/or tetrahedral type for the gas flow grid representation. It is mainly designed to predict the flow, thermal and transport properties of a rapidly vaporizing spray. Some important research areas covered as a part of the code development are: (1) the extension of combined CFD/scalar-Monte- Carlo-PDF method to spray modeling, (2) the multi-component liquid spray modeling, and (3) the assessment of various atomization models used in spray calculations. The current version contains the extension to the modeling of superheated sprays. The manual provides the user with an understanding of various models involved in the spray formulation, its code structure and solution algorithm, and various other issues related to parallelization and its coupling with other solvers.

  16. Influence of alkali metals (Na, Li, Rb) on the performance of electrostatic spray-assisted vapor deposited Cu2ZnSn(S,Se)4 solar cells

    NASA Astrophysics Data System (ADS)

    Altamura, Giovanni; Wang, Mingqing; Choy, Kwang-Leong

    2016-02-01

    Electrostatic Spray-Assisted Vapor Deposition (ESAVD) is a non-vacuum and cost-effective method to deposit metal oxide, various sulphide and chalcogenide at large scale. In this work, ESAVD was used to deposit Cu2ZnSn(S1-xSex)4 (CZTSSe) absorber. Different alkali metals like Na, Li and Rb were incorporated in CZTSSe compounds to further improve the photovoltaic performances of related devices. In addition, to the best of our knowledge, no experimental study has been carried out to test the effect of Li and Rb incorporation in CZTSSe solar cells. X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and glow discharge spectroscopy have been used to characterize the phase purity, morphology and composition of as-deposited CZTSSe thin films. Photovoltaic properties of the resulting devices were determined by completing the solar cells as follows: Mo/CZTSSe/CdS/i-ZnO/Al:ZnO/Ni/Al. The results showed that Li, Na and Rb incorporation can increase power conversion efficiency of CZTS devices up to 5.5%. The introduction of a thiourea treatment, has improved the quality of the absorber|buffer interface, pushed the device efficiency up to 6.3% which is at the moment the best reported result for ESAVD deposited CZTSSe solar cells.

  17. Influence of alkali metals (Na, Li, Rb) on the performance of electrostatic spray-assisted vapor deposited Cu2ZnSn(S,Se)4 solar cells.

    PubMed

    Altamura, Giovanni; Wang, Mingqing; Choy, Kwang-Leong

    2016-01-01

    Electrostatic Spray-Assisted Vapor Deposition (ESAVD) is a non-vacuum and cost-effective method to deposit metal oxide, various sulphide and chalcogenide at large scale. In this work, ESAVD was used to deposit Cu2ZnSn(S1-xSex)4 (CZTSSe) absorber. Different alkali metals like Na, Li and Rb were incorporated in CZTSSe compounds to further improve the photovoltaic performances of related devices. In addition, to the best of our knowledge, no experimental study has been carried out to test the effect of Li and Rb incorporation in CZTSSe solar cells. X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and glow discharge spectroscopy have been used to characterize the phase purity, morphology and composition of as-deposited CZTSSe thin films. Photovoltaic properties of the resulting devices were determined by completing the solar cells as follows: Mo/CZTSSe/CdS/i-ZnO/Al:ZnO/Ni/Al. The results showed that Li, Na and Rb incorporation can increase power conversion efficiency of CZTS devices up to 5.5%. The introduction of a thiourea treatment, has improved the quality of the absorber(|)buffer interface, pushed the device efficiency up to 6.3% which is at the moment the best reported result for ESAVD deposited CZTSSe solar cells. PMID:26916212

  18. Influence of alkali metals (Na, Li, Rb) on the performance of electrostatic spray-assisted vapor deposited Cu2ZnSn(S,Se)4 solar cells

    PubMed Central

    Altamura, Giovanni; Wang, Mingqing; Choy, Kwang-Leong

    2016-01-01

    Electrostatic Spray-Assisted Vapor Deposition (ESAVD) is a non-vacuum and cost-effective method to deposit metal oxide, various sulphide and chalcogenide at large scale. In this work, ESAVD was used to deposit Cu2ZnSn(S1−xSex)4 (CZTSSe) absorber. Different alkali metals like Na, Li and Rb were incorporated in CZTSSe compounds to further improve the photovoltaic performances of related devices. In addition, to the best of our knowledge, no experimental study has been carried out to test the effect of Li and Rb incorporation in CZTSSe solar cells. X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and glow discharge spectroscopy have been used to characterize the phase purity, morphology and composition of as-deposited CZTSSe thin films. Photovoltaic properties of the resulting devices were determined by completing the solar cells as follows: Mo/CZTSSe/CdS/i-ZnO/Al:ZnO/Ni/Al. The results showed that Li, Na and Rb incorporation can increase power conversion efficiency of CZTS devices up to 5.5%. The introduction of a thiourea treatment, has improved the quality of the absorber|buffer interface, pushed the device efficiency up to 6.3% which is at the moment the best reported result for ESAVD deposited CZTSSe solar cells. PMID:26916212

  19. 21 CFR 524.1044f - Gentamicin and betamethasone spray.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Gentamicin and betamethasone spray. 524.1044f... § 524.1044f Gentamicin and betamethasone spray. (a) Specifications. Each milliliter of spray contains... from the lesion and depress the sprayer head twice. Administer two spray actuations two to four...

  20. 21 CFR 524.1044f - Gentamicin and betamethasone spray.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Gentamicin and betamethasone spray. 524.1044f... § 524.1044f Gentamicin and betamethasone spray. (a) Specifications. Each milliliter of spray contains... from the lesion and depress the sprayer head twice. Administer two spray actuations two to four...