Absorption/desorption in sprays

International Nuclear Information System (INIS)

Naimpally, A.

1987-01-01

This survey paper shall seek to present the present state of knowledge concerning absorption and desorption in spray chambers. The first part of the paper presents the theories and formulas for the atomization and break-up of sprays in nozzles. Formulas for the average (sauter-mean) diameters are then presented. For the case of absorption processes, the formulas for the dimensionless mass transfer coefficients is in drops. The total; mass transfer is the total of the transfer in individual drops. For the case of desorption of sparingly soluble gases from liquids in a spray chamber, the mass transfer occurs in the spray just at the point of break-up of the jet. Formulas for the desorption of gases are presented

Reactor container spray device

International Nuclear Information System (INIS)

Yanai, Ryoichi.

1980-01-01

Purpose: To enable decrease in the heat and the concentration of radioactive iodine released from the reactor vessel into the reactor container in the spray device of BWR type reactors. Constitution: A plurality of water receiving trays are disposed below the spray nozzle in the dry well and communicated to a pressure suppression chamber by way of drain pipeways passing through a diaphragm floor. When the recycling system is ruptured and coolants in the reactor vessel and radioactive iodine in the reactor core are released into the dry well, spray water is discharged from the spray nozzle to eliminate the heat and the radioactive iodine in the dry well. In this case, the receiving trays collect the portions of spray water whose absorption power for the heat and radioactive iodine is nearly saturated and falls them into the pool water of the pressure suppression chamber. Consequently, other portions of the spray water that still possess absorption power can be jetted with no hindrance, to increase the efficiency for the removal of the heat and iodine of the spray droplets. (Horiuchi, T.)

Effects of Variations in Salt-Spray Conditions on the Corrosion Mechanisms of an AE44 Magnesium Alloy

Directory of Open Access Journals (Sweden)

Holly J. Martin

2010-01-01

Full Text Available The understanding of how corrosion affects magnesium alloys is of utmost importance as the automotive and aerospace industries have become interested in the use of these lightweight alloys. However, the standardized salt-spray test does not produce adequate corrosion results when compared with field data, due to the lack of multiple exposure environments. This research explored four test combinations through three sets of cycles to determine how the corrosion mechanisms of pitting, intergranular corrosion, and general corrosion were affected by the environment. Of the four test combinations, Humidity-Drying was the least corrosive, while the most corrosive test condition was Salt Spray-Humidity-Drying. The differences in corrosivity of the test conditions are due to the various reactions needed to cause corrosion, including the presence of chloride ions to cause pit nucleation, the presence of humidity to cause galvanic corrosion, and the drying phase which trapped chloride ions beneath the corrosion by-products.

The influence of raw material, added emulsifying salt and spray drying on cheese powder structure and hydration properties

DEFF Research Database (Denmark)

Felix da Silva, Denise; Larsen, Flemming Hofmann; Hougaard, Anni Bygvrå

2017-01-01

The present work has evaluated how raw material, addition of emulsifying salts (ES) and drying technology affect particle characteristics, structure, and hydration of cheese powders. In this context the spray drying technology induced the strongest effect on morphology and swelling of cheese powder...

Structure of Non-evaporating diesel sprays

International Nuclear Information System (INIS)

Mirza, M.R.; Baluch, A.H.; Tahir, Z.R.

2008-01-01

Need is always felt of some rational experimental information on fuel spray jet formation, its development and dispersion in the combustion chamber of an internal combustion engine. The latest study uses computational fluid dynamics for the modeling of engine flows. The original experimental work of the present author on non-evaporating sprays produced by a single-hole orifice type nozzle using a distribution type commercial fuel injection pump forms the basis to derive correlations for penetration rates, break up times and lengths of non-evaporating diesel sprays. The correlations derived can be used to do CFD modeling of sprays under variable conditions of injector nozzle hole diameter, fuel injection pressure and combustion chamber pressure. (author)

Modifications Of A Commercial Spray Gun

Science.gov (United States)

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.

Large Eddy Simulation of the spray formation in confinements

International Nuclear Information System (INIS)

Lampa, A.; Fritsching, U.

2013-01-01

Highlights: • Process stability of confined spray processes is affected by the geometric design of the spray confinement. • LES simulations of confined spray flow have been performed successfully. • Clustering processes of droplets is predicted in simulations and validated with experiments. • Criteria for specific coherent gas flow patterns and droplet clustering behaviour are found. -- Abstract: The particle and powder properties produced within spray drying processes are influenced by various unsteady transport phenomena in the dispersed multiphase spray flow in a confined spray chamber. In this context differently scaled spray structures in a confined spray environment have been analyzed in experiments and numerical simulations. The experimental investigations have been carried out with Particle-Image-Velocimetry to determine the velocity of the gas and the discrete phase. Large-Eddy-Simulations have been set up to predict the transient behaviour of the spray process and have given more insight into the sensitivity of the spray flow structures in dependency from the spray chamber design

Synthesis of complex oxides with garnet structure by spray drying of an aqueous salt solution

Science.gov (United States)

Makeenko, A. V.; Larionova, T. V.; Klimova-Korsmik, O. G.; Starykh, R. V.; Galkin, V. V.; Tolochko, O. V.

2017-04-01

The use of spray drying to obtain powders of complex oxides with a garnet structure has demonstrated. The processes occurring during heating of the synthesized oxide-salt product, leading to the formation of a material with a garnet structure, have been investigated using DTA, TGA, XPS, and XRD. It has been shown that a single-phase garnet structure of system (Y x Gd(3- x))3Al5O12 can be synthesized over the entire range of compositions.

Production of dried shrimp mixed with turmeric and salt by Spouted Bed technique enter the rectangular chamber.

Science.gov (United States)

Thanthong, P.; Mustafa, Y.; Ngamrungroj, D.

2017-09-01

Today, dried shrimp in the market were refused food colour and drying until shrimp are colourful and tasty. Meanwhile, Community groups, women’s health trying to produce food products come from herbs. As an alternative to consumers. The production process is also a traditional way to dry. In order to extend the shelf life longer. Sometimes, potential risks, both in quality and quantity of products. As a result, consumers are enormous. Thus, this research aims to study the possibility to produce shrimp dried mixed with turmeric and salt. Then dried shrimp mixed with turmeric and salt to keep up the quality criteria of the Food and Drug Administration-FDA It can reduce the risk of the consumer and can keep up in a kitchen Thailand. When buying shrimp from the fisherman’s boat Will be made clear, clean impurities and shaking the sand to dry. Prepare a mixture of turmeric and salt. The shrimp were dipped into a beef with stirrer for 3 minutes. And scoop up centrifugal shrimp with dried. Measurement of initial moisture content averaging 78%wb. Then drying technique Spouted enter the rectangular chamber a continuous manner. Until average moisture content to 17%wb. The air temperature in the drying chamber at 180 °C and hot air speed 4.5 m/s, a state heat transfer Mass and moisture within the shrimp. In chamber when drying, the shrimp have moved freely behaviour can spit water out faster does not burn. Shaving legs of shrimp shell fragments lightweight is sorting out the top of drying chamber. Private shrimp were dried out to the front of the quad drying chamber. Power consumption 27.5 MJ/kg, divided into electrical energy 12.3 MJ/kg and thermal energy is 15.2 MJ/kg. The hot air comes from burning LPG gas burner with dual automatic. And can adjustable to room temperature drying characteristics modulation setting.

Checking technical measurements on climatic data during sand blasting and spraying work in the condensation chamber of the boiling water reactor Gundremmingen

International Nuclear Information System (INIS)

Rausch, D.; Unte, U.

1986-01-01

During sand blasting and spraying work in the condensation chambers of boiling water reactors prescribed climatic data must be adhered to. For this purpose temporary air conditioners are used. The technical measurement examination here should provide information as to whether the air conditioners used were to fulfill the parameter curve specifications. (orig.) [de

Corrosion of lanthanum magnesium hexaaluminate as plasma-sprayed coating and as bulk material when exposed to molten V2O5-containing salt

International Nuclear Information System (INIS)

Chen, Xiaolong; Cao, Xueqiang; Zou, Binglin; Gong, Jun; Sun, Chao

2015-01-01

Highlights: • Corrosion behavior of LaMgAl 11 O 19 bulk and plasma sprayed coating has been compared. • Degradation mechanism is investigated based on LaMgAl 11 O 19 ’s crystal chemistry. • LaMgAl 11 O 19 coating displays inferior corrosion resistance to well crystallized bulk. - Abstract: Corrosion of LaMgAl 11 O 19 (LaMA) bulk and plasma sprayed coating was studied in molten V 2 O 5 -containing salt at 710–1050 °C in air. Results indicate that the well crystallized LaMA bulk exhibited prior corrosion resistance to the plasma sprayed LaMA coating with amorphous phase and reduced chemical bond strength in its crystal structure. La–O chemical bonds with the lowest bond energies were the easiest bonds in the LaMA crystal to be broken by molten V 2 O 5 -containing salt attack to form LaVO 4 at each temperature level for both LaMA bulk and coating. Corrosion products of the LaMA coating were much different at temperature below 900 °C

Simulated Field Trials Using an Indoor Aerosol Test Chamber

National Research Council Canada - National Science Library

Semler, D. D; Roth, A. P; Semler, K. A; Nolan, P. M

2004-01-01

.... In this method, the aerosol chamber control software manipulates circulation fan speeds, chamber vacuum and agent spray times to produce a simulated dynamic cloud within the aerosol test chamber...

Simulated Field Trials Using An Indoor Aerosol Test Chamber

National Research Council Canada - National Science Library

Semler, D. D; Roth, A. P; Semler, K. A; Nolan, P. M

2004-01-01

.... In this method, the aerosol chamber control software manipulates circulation fan speeds, chamber vacuum and agent spray times to produce a simulated dynamic cloud within the aerosol test chamber...

A study on the macroscopic spray behavior and atomization characteristics of biodiesel and dimethyl ether sprays under increased ambient pressure

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyung Jun; Park, Su Han [Graduate School of Hanyang University, 17 Haengdang-dong, Seoungdong-gu, Seoul 133-791 (Korea); Lee, Chang Sik [Department of Mechanical Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea)

2010-03-15

The aim of this work is to investigate the spray behaviors of biodiesel and dimethyl ether (DME) fuels using image processing and atomization performance analysis of the two fuel sprays injected through a common-rail injection system under various ambient pressure conditions in a high pressure chamber. In order to observe the biodiesel and DME fuel spray behaviors under various ambient pressures, the spray images were analyzed at various times after the start of energization using a visualization system consisting of a high speed camera and two metal halide light sources. In addition, a high pressure chamber that can withstand a pressure of 4 MPa was used for adjusting the ambient pressure. From the spray images, spray characteristics such as the spray tip penetration, cone angle, area, and contour plot at various light intensity levels were analyzed using image conversion processing. Also, the local Sauter mean diameters (SMD) were measured at various axial/radial distances from the nozzle tip by a droplet measuring system to compare the atomization performances of the biodiesel and DME sprays. The results showed that the ambient pressure had a significant effect on the spray characteristics of the fuels at the various experimental conditions. The spray tip penetration and spray area decreased as the ambient pressure increased. The contour plot of the biodiesel and DME sprays showed a high light intensity level in the center regions of the sprays. In addition, it was revealed that the atomization performance of the biodiesel spray was inferior to that of the DME spray at the same injection and ambient conditions. (author)

Hot corrosion behavior of plasma-sprayed partially stabilized zirconia coatings in a lithium molten salt

International Nuclear Information System (INIS)

Cho, Soo Haeng; Hong, Sun Seok; Kang, Dae Seong; Park, Byung Heong; Hur, Jin Mok; Lee, Han Soo

2008-01-01

The electrolytic reduction of spent oxide fuel involves the liberation of oxygen in a molten LiCl electrolyte, which results in a chemically aggressive environment that is too corrosive for typical structural materials. It is essential to choose the optimum material for the process equipment handling molten salt. IN713LC is one of the candidate materials proposed for application in electrolytic reduction process. In this study, Yttria-Stabilized Zirconia (YSZ) top coat was applied to a surface of IN713LC with an aluminized metallic bond coat by an optimized plasma spray process, and were investigated the corrosion behavior at 675 .deg. C for 216 hours in the molten salt LiCl-Li 2 O under an oxidizing atmosphere. The as-coated and tested specimens were examined by OM, SEM/EDS and XRD, respectively. The bare superalloy reveals obvious weight loss, and the corrosion layer formed on the surface of the bare superalloy was spalled due to the rapid scale growth and thermal stress. The top coatings showed a much better hot-corrosion resistance in the presence of LiCl-Li 2 O molten salt when compared to those of the uncoated superalloy and the aluminized bond coatings. These coatings have been found to be beneficial for increasing to the hot-corrosion resistance of the structural materials for handling high temperature lithium molten salts

Stress Corrosion Cracking Susceptibility of 304L Substrate and 308L Weld Metal Exposed to a Salt Spray

Directory of Open Access Journals (Sweden)

Chia-Hao Hsu

2017-02-01

Full Text Available 304 stainless steels (SS were considered as the materials for a dry storage canister. In this study, ER (Electrode Rod 308L was utilized as the filler metal for the groove and overlay welds of a 304L stainless steel substrate, which was prepared via a gas tungsten arc-welding process in multiple passes. The electron backscatter diffraction (EBSD map was used to identify the inherent microstructures in distinct specimens. U-bend and weight-loss tests were conducted by testing the 304L substrates and welds in a salt spray containing 5 wt % NaCl at 80 °C to evaluate their susceptibility to stress corrosion cracking (SCC. Generally, the weight loss of the ER 308L deposit was higher than that of the 304L substrate in a salt spray in the same sample-prepared condition. The dissolution of the skeletal structure in the fusion zone (FZ was responsible for a greater weight loss of the 308L deposit, especially for the cold-rolled and sensitized specimen. Cold rolling was detrimental and sensitization after cold rolling was very harmful to the SCC resistance of the 304L substrate and 308L deposit. Overall, the SCC susceptibility of each specimen was correlated with its weight loss in each group.

Investigations on backfilling and sealing of chambers and shafts in a final salt repository

International Nuclear Information System (INIS)

Glaess, F.; Kappei, G.; Schmidt, M.W.; Schwieger, K.; Starke, C.; Taubert, E.; Wallmueller, R.; Walter, F.; Tischle, N.R.; Haensel, W.; Meyer, T.

1991-03-01

Soil mechanical laboratory investigations as well as geotechnical in situ measurements were carried out. The laboratory tests provided important information on the material behaviour of selected backfill and sealing materials. Initial conclusions on the long-term behaviour of backfill and seals as well as on their interaction with the rock were gained with the results of in situ measurements in backfilled chambers and seals and in the surrounding rock of the Asse salt mine. (orig./DG) [de

Direct introduction of volatile carbon compounds into the spray chamber of an inductively coupled plasma mass spectrometer: Sensitivity enhancement for selenium

International Nuclear Information System (INIS)

Kovacevic, Miroslav; Goessler, Walter

2005-01-01

The effect of signal enhancement of elements with ionization potentials in the range from 9 to 11 eV by carbon-containing compounds is a well-known phenomenon in inductively coupled plasma mass spectrometry (ICPMS). It has traditionally been exploited through the addition of organic solvents to the sample matrix or to the mobile phase to improve sensitivity. In the present work, aqueous solutions of volatile carbon compounds (acetone, methanol and acetic acid) were directly introduced into the thermostatted spray chamber rather than being added to the sample matrix. It is presumed that no aerosol is produced from these solutions and only vapors of organic compounds are swept into the plasma together with the sample aerosol. When a 0.40 mol l -1 aqueous solution of acetone was introduced directly into the spray chamber, the signals for arsenic and selenium were enhanced by a factor of 4.2. The usefulness of this approach was demonstrated through the achievement of lower instrumental detection limits for selenium at m/z 82 (0.1 ng ml -1 ) compared to the system without direct introduction of volatile carbon compounds (0.5 ng ml -1 ). The method was successfully applied in the determination of traces of selenium in natural water, urine and bovine liver reference material

Sea Spray Aerosols

DEFF Research Database (Denmark)

Butcher, Andrew Charles

emissions produced directly from bubble bursting as the result of air entrainment from breaking waves and particles generated from secondary emissions of volatile organic compounds. In the first paper, we study the chemical properties of particles produced from several sea water proxies with the use...... of a cloud condensation nuclei ounter. Proxy solutions with high inorganic salt concentrations and some organics produce sea spray aerosol particles with little change in cloud condensation activity relative to pure salts. Comparison is made between a frit based method for bubble production and a plunging...... a relationship between plunging jet particle ux, oceanic particle ux, and energy dissipation rate in both systems. Previous sea spray aerosol studies dissipate an order of magnitude more energy for the same particle ux production as the open ocean. A scaling factor related to the energy expended in air...

Slurry spray distribution within a simulated laboratory scale spray dryer

International Nuclear Information System (INIS)

Bertone, P.C.

1979-01-01

It was found that the distribution of liquid striking the sides of a simulated room temperature spray dryer was not significantly altered by the choice of nozles, nor by a variation in nozzle operating conditions. Instead, it was found to be a function of the spray dryer's configuration. A cocurrent flow of air down the drying cylinder, not possible with PNL's closed top, favorably altered the spray distribution by both decreasing the amount of liquid striking the interior of the cylinder from 72 to 26% of the feed supplied, and by shifting the zone of maximum impact from 1.0 to 1.7 feet from the nozzle. These findings led to the redesign of the laboratory scale spray dryer to be tested at the Savannah River Plant. The diameter of the drying chamber was increased from 5 to 8 inches, and a cocurrent flow of air was established with a closed recycle. Finally, this investigation suggested a drying scheme which offers all the advantages of spray drying without many of its limitations

High temperature oxidation and corrosion in marine environments of thermal spray deposited coatings

International Nuclear Information System (INIS)

Chaliampalias, D.; Vourlias, G.; Pavlidou, E.; Stergioudis, G.; Skolianos, S.; Chrissafis, K.

2008-01-01

Flame spraying is a widely used technique for depositing a great variety of materials in order to enforce the mechanical or the anticorrosion characteristics of the substrate. Its high rate application is due to the rapidity of the process, its effectiveness and its low cost. In this work, flame-sprayed Al coatings are deposited on low carbon steels in order to enhance their anticorrosion performance. The main adhesion mechanism of the coating is mechanical anchorage, which can provide the necessary protection to steel used in several industrial and constructive applications. To evaluate the corrosion resistance of the coating, the as-coated samples are subjected in a salt spray chamber and in elevated temperature environments. The examination and characterization of the corroded samples is done by scanning electron microscopy and X-ray diffraction analysis. The as-formed coatings are extremely rough and have a lamellic homogeneous morphology. It is also found that Al coatings provide better protection in marine atmospheres, while at elevated temperatures a thick oxide layer is formed, which can delaminate after long oxidation periods due to its low adherence to the underlying coating, thus eliminating the substrate protection

Influence of fuel temperature on dispersion and decay of BDE sprays; Einfluss der Kraftstofftemperatur auf die Ausbreitung und den Zerfall von BDE-Sprays

Energy Technology Data Exchange (ETDEWEB)

Schmitz, I.; Beyrau, F.; Leipertz, A. [Erlangen-Nuernberg Univ., Erlangen (Germany). Lehrstuhl fuer Technische Thermodynamik

2007-07-01

As an example for a highly - developed technical spray system, the spray vaporization of a multi - hole injector used for the gasoline direct injection (GDI) has been investigated. Experiments were conducted in a heated injection chamber for different chamber pressures, fuels and fuel temperatures. In this investigation pure rotational coherent anti-Stokes Raman spectroscopy (RCARS) has been applied to the study of vaporizing sprays in combination with other laser techniques. Gas phase temperatures inside the sprays have been determined with high spatial and temporal resolution. A temperature drop of about 30 K was measured for all fuel temperatures studied. Droplet sizes and number densities have been measured using phase Doppler anemometry, and the correlation of these results with two - dimensional laser sheet Mie scattering images and laser-induced exciplex fluorescence allows an improved interpretation of the spray vaporization process. Furthermore under the influence of flash boiling a reduction of the mean drop size D10 up to 30% could be observed. (orig.)

SPRAY code user's report

International Nuclear Information System (INIS)

Shire, P.R.

1977-03-01

The SPRAY computer code has been developed to model the effects of postulated sodium spray release from LMFBR piping within containment chambers. The calculation method utilizes gas convection, heat transfer and droplet combustion theory to calculate the pressure and temperature effects within the enclosure. The applicable range is 0-21 mol percent oxygen and .02-.30 inch droplets with or without humidity. Droplet motion and large sodium surface area combine to produce rapid heat release and pressure rise within the enclosed volume

Effect of expansion chamber geometry on atomization and spray dispersion characters of a flashing mixture containing inerts. Part I. Numerical predictions and dual laser measurements.

Science.gov (United States)

Ju, Dehao; Shrimpton, John; Bowdrey, Moira; Hearn, Alex

2012-08-01

A cigarette alternative is designed to deliver a dose of medicinal nicotine within a timeframe comparable to that of a cigarette, and gives much of what smokers expect from a cigarette without the risks of smoking tobacco. The design concept is the same as a pressurized metered dose inhaler (pMDI), but is a breath actuated device (Oxette(®)). This work predicts the residual mass median diameter (MMD) of the spray issuing from early stage Oxette(®) prototypes by using an evaporation model of multi-component liquid droplets with the help of a numerical multi-component two-phase actuation model (developed by the authors) to quantify the sprays. Two different formulations with 95% and 98% mass fraction of HFA 134a, and two prototypes of cigarette alternatives with different expansion chamber volumes have been analyzed by the numerical model and compared with laser based measurements. The later designed device provides a larger expansion chamber volume to enhance the propellant evaporation, recirculation, bubble generation and growth inside the chamber, and it makes a significant improvement to produce finer sprays than the earlier design. The mass fraction of the formulation does not affect significantly on the initial MMD of the droplets near the discharge orifice. However, it influences the residual MMD at x=100mm from the discharge orifice, where the ratio of the predicted residual MMDs of the droplets generated by the formulations with 98% and 95% of HFA 134a is 0.73. Although the formulation with 98% of HFA 134a can generate smaller droplets, the formulation with 95% of HFA 134a produces more steady puffs with relatively low mass flow rate. Copyright © 2012 Elsevier B.V. All rights reserved.

Corrosion behaviors and effects of corrosion products of plasma electrolytic oxidation coated AZ31 magnesium alloy under the salt spray corrosion test

International Nuclear Information System (INIS)

Wang, Yan; Huang, Zhiquan; Yan, Qin; Liu, Chen; Liu, Peng; Zhang, Yi; Guo, Changhong; Jiang, Guirong; Shen, Dejiu

2016-01-01

Highlights: • Corrosion behaviors of a PEO coating was investigated after the salt spray test. • Corrosion products have significant effects on corrosion behaviors of the coating. • An electrochemical corrosion model is proposed. - Abstract: The effects of corrosion products on corrosion behaviors of AZ31 magnesium alloy with a plasma electrolytic oxidation (PEO) coating were investigated under the salt spray corrosion test (SSCT). The surface morphology, cross-sectional microstructure, chemical and phase compositions of the PEO coating were determined using scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction analysis (XRD), respectively. Further, the corrosion process of the samples under the SSCT was examined in a non-aqueous electrolyte (methanol) using electrochemical impedance spectroscopy (EIS) coupled with equivalent circuit. The results show that the inner layer of the coating was destroyed firstly and the corrosion products have significant effects on the corrosion behaviors of the coating. The results above are discussed and an electrochemical corrosion model is proposed in the paper.

Corrosion behaviors and effects of corrosion products of plasma electrolytic oxidation coated AZ31 magnesium alloy under the salt spray corrosion test

Energy Technology Data Exchange (ETDEWEB)

Wang, Yan; Huang, Zhiquan; Yan, Qin; Liu, Chen; Liu, Peng; Zhang, Yi [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Guo, Changhong; Jiang, Guirong [College of Mechanical Engineering, Yanshan University, Qinhuangdao 066004 (China); Shen, Dejiu, E-mail: DejiuShen@163.com [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China)

2016-08-15

Highlights: • Corrosion behaviors of a PEO coating was investigated after the salt spray test. • Corrosion products have significant effects on corrosion behaviors of the coating. • An electrochemical corrosion model is proposed. - Abstract: The effects of corrosion products on corrosion behaviors of AZ31 magnesium alloy with a plasma electrolytic oxidation (PEO) coating were investigated under the salt spray corrosion test (SSCT). The surface morphology, cross-sectional microstructure, chemical and phase compositions of the PEO coating were determined using scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction analysis (XRD), respectively. Further, the corrosion process of the samples under the SSCT was examined in a non-aqueous electrolyte (methanol) using electrochemical impedance spectroscopy (EIS) coupled with equivalent circuit. The results show that the inner layer of the coating was destroyed firstly and the corrosion products have significant effects on the corrosion behaviors of the coating. The results above are discussed and an electrochemical corrosion model is proposed in the paper.

Performance of a Compression-ignition Engine with a Precombustion Chamber Having High-Velocity Air Flow

Science.gov (United States)

Spanogle, J A; Moore, C S

1931-01-01

Presented here are the results of performance tests made with a single-cylinder, four stroke cycle, compression-ignition engine. These tests were made on a precombustion chamber type of cylinder head designed to have air velocity and tangential air flow in both the chamber and cylinder. The performance was investigated for variable load and engine speed, type of fuel spray, valve opening pressure, injection period and, for the spherical chamber, position of the injection spray relative to the air flow. The pressure variations between the pear-shaped precombustion chamber and the cylinder for motoring and full load conditions were determined with a Farnboro electric indicator. The combustion chamber designs tested gave good mixing of a single compact fuel spray with the air, but did not control the ensuing combustion sufficiently. Relative to each other, the velocity of air flow was too high, the spray dispersion by injection too great, and the metering effect of the cylinder head passage insufficient. The correct relation of these factors is of the utmost importance for engine performance.

Dehydration of ethanol with salt extractive distillation-a comparative analysis between processes with salt recovery

Energy Technology Data Exchange (ETDEWEB)

Ligero, E.L.; Ravagnani, T.M.K. [Departamento de Engenharia de Sistemas Qumicos, Faculdade de Engenharia Qumica, Universidade Estadual de Campinas, Campinas, Sao Paulo (Brazil)

2003-07-01

Anhydrous ethanol can be obtained from a dilute aqueous solution of ethanol via extractive distillation with potassium acetate. Two process flowsheets with salt recovery were proposed. In the first, dilute ethanol is directly fed to a salt extractive distillation column and, after that, the salt is recovered in a multiple effect evaporator followed by a spray dryer. In the second, the concentrated ethanol from conventional distillation is fed to a salt extractive distillation column. In this case, salt is recovered in a single spray dryer. In both processes the recovered salt is recycled to be used in the extractive distillation column. Every component of each process was rigorously modeled and its behavior was simulated for a wide range of operating conditions. A global simulation was then carried out. The results show that the second process is more interesting in terms of energy consumption than the first. Furthermore, it would be easier to implement changes on existing benzene extractive anhydrous ethanol plants to convert them to more ecologically attractive concentrated ethanol feed processes. (author)

Influence of road salting on the adjacent Norway spruce (Picea abies) forest

International Nuclear Information System (INIS)

Forczek, S.T.; Benada, O.; Kofronova, O.; Sigler, K.; Matucha, M.

2011-01-01

Winter deicing and traffic spreads salt to road-adjacent Norway spruce trees in the form of spraying and salt slops. Our use of Na36Cl revealed roots as the main pathway of salt uptake. One-shot application of a concentrated Na36Cl solution to spruce saplings by both irrigation and spraying causes macroscopic damage to the needles and affects the needle phyllosphere. Irrigation affects the trees more than spraying because Cl uptake through roots is faster and eventually leads to higher chloride content in the plant. Along with the root-needle route, spray-deposited chloride from the needles is re-transported back into the soil and again taken up by roots to needles

Spray drying for processing of nanomaterials

International Nuclear Information System (INIS)

Lindeloev, Jesper Saederup; Wahlberg, Michael

2009-01-01

Consolidation of nano-particles into micron-sized granules reduces the potential risks associated with handling nano-powders in dry form. Spray drying is a one step granulation technique which can be designed for safe production of free flowing low dusty granules from suspensions of nano-particles. Spray dried granules are well suited for subsequent processing into final products where the superior properties given by the nano-particles are retained. A spray drier with bag filters inside the drying chamber and recycling of drying gas combined with containment valves are proposed as a safe process for granulation of potential hazardous nano-particles.

Study of ethanol and gasoline fuel sprays using mie-scatter and schlieren imaging

Science.gov (United States)

Bouchard, Lauren; Bittle, Joshua; Puzinauskas, Paul

2016-11-01

Many cars today are capable of running on both gasoline and ethanol, however it is not clear how well optimized the engines are for the multiple fuels. This experiment looks specifically at the fuel spray in a direct injection system. The length and angle of direct injection sprays were characterized and a comparison between ethanol and gasoline sprays was made. Fuels were tested using a modified diesel injector in a test chamber at variable ambient pressures and temperatures in order to simulate both high and low load combustion chamber conditions. Rainbow schlieren and mie-scatter imaging were both used to investigate the liquid and vapor portions of the sprays. The sprays behaved as expected with temperature and pressure changes. There was no noticeable fuel effect on the liquid portion of the spray (mie-scatter), though the gasoline vapor spray angles were wider than ethanol spray angles (possible a result of the distillation curves of the two fuels). Funding from NSF REU site Grant EEC 1358991 is greatly appreciated.

Corrosion characterization of in-situ titanium diboride (TiB2) reinforced aluminium-copper (Al-Cu) alloy by two methods: Salts spray fog and linear polarization resistance (LPR)

Science.gov (United States)

Rosmamuhamadani, R.; Talari, M. K.; Yahaya, Sabrina M.; Sulaiman, S.; Ismail, M. I. S.; Hanim, M. A. Azmah

2018-05-01

Aluminium-copper (Al-Cu) alloys is the one of most Metal Matrix Composites (MMCs) have important high-strength Al alloys. The aluminium (Al) casting alloys, based on the Al-Cu system are widely used in light-weight constructions and transport applications requiring a combination of high strength and ductility. In this research, Al-Cu master alloy was reinforced with 3 and 6wt.% titanium diboride (TiB2) that obtained from salts route reactions. The salts used were were potassium hexafluorotitanate (K2TiF6) and potassium tetrafluoroborate (KBF4). The salts route reaction process were done at 800 °C. The Al-Cu alloy then has characterized on the mechanical properties and microstructure characterization. Salts spray fog test and Gamry-electrode potentiometer instruments were used to determine the corrosion rate of this alloys. From results obtained, the increasement of 3wt.%TiB2 contents will decrease the value of the corrosion rate. In corrosion test that conducted both of salt spray fog and Gamry-electrode potentiometer, the addition of 3wt.%TiB2 gave the good properties in corrosion characterization compare to Al-Cu-6wt.%TiB2 and Al-Cu cast alloy itself. As a comparison, Al-Cu with 3wt.%TiB2 gave the lowest value of corrosion rate, which means alloy has good properties in corrosion characterization. The results obtained show that in-situ Al-Cu alloy composites containing the different weight of TiB2 phase were synthesized successfully by the salt-metal reaction method.

Analysis of spatial dispersion characteristics of improved conical sprays; Kairyo kasajo funmu no kukan bunsansei no kento

Energy Technology Data Exchange (ETDEWEB)

Long, W; Murakami, A; Hama, J [Mechanical Engineering Lab., Tokyo (Japan); Obokata, T [Gunma University, Gunma (Japan)

1997-10-01

The macro-characteristics of conical and improved conical sprays were analyzed using laser sheet and high speed camera. The injection pressure was 14.7, 24.5 or 34.3 MPa and the chamber pressure was 0.098, 0.98 or 1.96 MPa, where the amount of injected fuel was 28.5 mg per cycle, and the injection frequency was 8.3 Hz. As a result, at atmospheric pressure, both of the conical spray and improved conical spray have a conical pattern, but at high chamber pressure, the sprays become three dimensional. The penetration of the improved conical spray was about 25% stronger than that of the conical spray. 10 refs., 11 figs.

Fuel spray and combustion characteristics of butanol blends in a constant volume combustion chamber

International Nuclear Information System (INIS)

Liu, Yu; Li, Jun; Jin, Chao

2015-01-01

Highlights: • A sudden drop is observed in spray penetration for B10S10D80 fuel at 800 and 900 K. • With increasing of temperature, auto-ignition timings of fuels become unperceivable. • Low n-butanol addition has little effect on autoignition timings from 800 to 1200 K. • n-Butanol additive can reduce soot emissions at the near-wall regions. • Larger soot reduction is seen at higher ambient temperatures for n-butanol addition. - Abstract: The processes of spray penetrations, flame propagation and soot formation and oxidation fueling n-butanol/biodiesel/diesel blends were experimentally investigated in a constant volume combustion chamber with an optical access. B0S20D80 (0% n-butanol, 20% soybean biodiesel, and 80% diesel in volume) was prepared as the base fuel. n-Butanol was added into the base fuel by volumetric percent of 5% and 10%, denoted as B5S15D80 (5% n-butanol/15% soybean biodiesel/80% diesel) and B10S10D80 (10% n-butanol/10% soybean biodiesel/80% diesel). The ambient temperatures at the time of fuel injection were set to 800 K, 900 K, 1000 K, and 1200 K. Results indicate that the penetration length reduces with the increase of n-butanol volumes in blending fuels and ambient temperatures. The spray penetration presents a sudden drop as fueling B10S10D80 at 800 K and 900 K, which might be caused by micro-explosion. A larger premixed combustion process is observed at low ambient temperatures, while the heat release rate of high ambient temperatures presents mixing controlled diffusion combustion. With a lower ambient temperature, the auto-ignition delay becomes longer with increasing of n-butanol volume in blends. However, with increasing of ambient temperatures, the auto-ignition timing between three fuels becomes unperceivable. Generally, low n-butanol addition has a limited or no effect on the auto-ignition timing in the current conditions. Compared with the base fuel of B0S20D80, n-butanol additive with 5% or 10% in volume can reduce soot

Experiments on aerosol removal by high-pressure water spray

Energy Technology Data Exchange (ETDEWEB)

Corno, Ada del, E-mail: delcorno@rse-web.it [RSE, Power Generation Technologies and Materials Dept, via Rubattino 54, I-20134 Milano (Italy); Morandi, Sonia, E-mail: morandi@rse-web.it [RSE, Power Generation Technologies and Materials Dept, via Rubattino 54, I-20134 Milano (Italy); Parozzi, Flavio, E-mail: parozzi@rse-web.it [RSE, Power Generation Technologies and Materials Dept, via Rubattino 54, I-20134 Milano (Italy); Araneo, Lucio, E-mail: lucio.araneo@polimi.it [Politecnico di Milano, Department of Energy, via Lambruschini 4A, I-20156 Milano (Italy); CNR-IENI, via Cozzi 53, I-20125 Milano (Italy); Casella, Francesco, E-mail: francesco2.casella@mail.polimi.it [Politecnico di Milano, Department of Energy, via Lambruschini 4A, I-20156 Milano (Italy)

2017-01-15

Highlights: • Experimental research to measure the efficiency of high-pressure sprays in capturing aerosols if applied to a filtered containment venting system in case of severe accident. • Cloud of monodispersed SiO{sub 2} particles with sizes 0.5 or 1.0 μm and initial concentration in the range 2–90 mg/m{sup 3}. • Carried out in a chamber 0.5 × 1.0 m and 1.5 m high, with transparent walls equipped with a high pressure water spray with single nozzle. • Respect to low-pressure sprays, removal efficiency turned out significant: the half-life for 1 μm particles with a removal high-pressure spray system is orders of magnitude shorter than that with a low-pressure sprays system. - Abstract: An experimental research was managed in the framework of the PASSAM European Project to measure the efficiency of high-pressure sprays in capturing aerosols when applied to a filtered containment venting system in case of severe accident. The campaign was carried out in a purposely built facility composed by a scrubbing chamber 0.5 × 1.0 m and 1.5 m high, with transparent walls to permit the complete view of the aerosol removal process, where the aerosol was injected to form a cloud of specific particle concentration. The chamber was equipped with a high pressure water spray system with a single nozzle placed on its top. The test matrix consisted in the combination of water pressure injections, in the range 50–130 bar, on a cloud of monodispersed SiO{sub 2} particles with sizes 0.5 or 1.0 μm and initial concentration ranging between 2 and 99 mg/m{sup 3}. The spray was kept running for 2 min and the efficiency of the removal was evaluated, along the test time, using an optical particle sizer. With respect to low-pressure sprays, the removal efficiency turned out much more significant: the half-life for 1 μm particles with a removal high-pressure spray system is orders of magnitude shorter than that with a low-pressure spray system. The highest removal rate was

Experiments on aerosol removal by high-pressure water spray

International Nuclear Information System (INIS)

Corno, Ada del; Morandi, Sonia; Parozzi, Flavio; Araneo, Lucio; Casella, Francesco

2017-01-01

Highlights: • Experimental research to measure the efficiency of high-pressure sprays in capturing aerosols if applied to a filtered containment venting system in case of severe accident. • Cloud of monodispersed SiO_2 particles with sizes 0.5 or 1.0 μm and initial concentration in the range 2–90 mg/m"3. • Carried out in a chamber 0.5 × 1.0 m and 1.5 m high, with transparent walls equipped with a high pressure water spray with single nozzle. • Respect to low-pressure sprays, removal efficiency turned out significant: the half-life for 1 μm particles with a removal high-pressure spray system is orders of magnitude shorter than that with a low-pressure sprays system. - Abstract: An experimental research was managed in the framework of the PASSAM European Project to measure the efficiency of high-pressure sprays in capturing aerosols when applied to a filtered containment venting system in case of severe accident. The campaign was carried out in a purposely built facility composed by a scrubbing chamber 0.5 × 1.0 m and 1.5 m high, with transparent walls to permit the complete view of the aerosol removal process, where the aerosol was injected to form a cloud of specific particle concentration. The chamber was equipped with a high pressure water spray system with a single nozzle placed on its top. The test matrix consisted in the combination of water pressure injections, in the range 50–130 bar, on a cloud of monodispersed SiO_2 particles with sizes 0.5 or 1.0 μm and initial concentration ranging between 2 and 99 mg/m"3. The spray was kept running for 2 min and the efficiency of the removal was evaluated, along the test time, using an optical particle sizer. With respect to low-pressure sprays, the removal efficiency turned out much more significant: the half-life for 1 μm particles with a removal high-pressure spray system is orders of magnitude shorter than that with a low-pressure spray system. The highest removal rate was detected with 1 �

Sample introduction systems for reversed phase LC-ICP-MS of selenium using large amounts of methanol - comparison of systems based on membrane desolvation, a spray chamber and direct injection

DEFF Research Database (Denmark)

Bendahl, L.; Gammelgaard, Bente

2005-01-01

nebuliser (MCN) in combination with a membrane desolvator ( MD), a MCN in combination with a cyclonic spray chamber ( CS) and a direct injection nebuliser ( DIN), respectively. Thirteen selenium standards diluted in 50% methanol were introduced in each system at a flow rate of 50 mu l min(-1). Except...

Process for the recovery of alkali metal salts from aqueous solutions thereof

International Nuclear Information System (INIS)

Vitner, J.

1984-01-01

In an integrated process for the recovery of alkakli metal phenates and carboxylates from aqueous solutions thereof, the aqueous solution is spray dried and the drying gas stream is contacted with an aqueous alkali metal salt solution which dissolves the particles of the alkali metal salt that were entrained in the drying gas stream. The salt-free inert gas stream is then dried, heated, and returned to the spray dryer

In-nozzle flow and spray characteristics for mineral diesel, Karanja, and Jatropha biodiesels

International Nuclear Information System (INIS)

Agarwal, Avinash Kumar; Som, Sibendu; Shukla, Pravesh Chandra; Goyal, Harsh; Longman, Douglas

2015-01-01

Highlights: • In-nozzle flow characterization for biodiesel sprays. • Comparison of experimental spray parameters and nozzle hole simulations. • Effect of Karanja and Jatropha biodiesel on in-nozzle cavitation. • Cavitation formation investigation with diesel and biodiesels. • Nozzle hole outlet fuel velocity profile determination for test fuels. - Abstract: Superior spray behavior of fuels in internal combustion engines lead to improved combustion and emission characteristics therefore it is necessary to investigate fuel spray behavior of new alternative fuels. This study discusses the evolution of the in-nozzle orifice parameters of a numerical simulation and the evolution of spray parameters of fuel spray in a constant-volume spray chamber during an experiment. This study compares mineral diesel, biodiesels (Karanja-and Jatropha-based), and their blends with mineral diesel. The results show that mineral diesel provides superior atomization and evaporation behavior compared to the biodiesel test fuels. Karanja biodiesel provides superior atomization and evaporation characteristics compared to Jatropha biodiesel. The qualitative comparison of simulation and experimental results in tandem shows that nozzle-hole design is a critical parameter for obtaining optimum spray behavior in the engine combustion chamber

HYLIFE-II reactor chamber design refinements

International Nuclear Information System (INIS)

House, P.A.

1994-06-01

Mechanical design features of the reactor chamber for the HYLIFE-II inertial confinement fusion power plant are presented. A combination of oscillating and steady, molten salt streams (Li 2 BeF 4 ) are used for shielding and blast protection of the chamber walls. The system is designed for a 6 Hz repetition rate. Beam path clearing, between shots, is accomplished with the oscillating flow. The mechanism for generating the oscillating streams is described. A design configuration of the vessel wall allows adequate cooling and provides extra shielding to reduce thermal stresses to tolerable levels. The bottom portion of the reactor chamber is designed to minimize splash back of the high velocity (>12 m/s) salt streams and also recover up to half of the dynamic head. Cost estimates for a 1 GWe and 2 GWe reactor chamber are presented

Numerical modelling of fuel sprays

Energy Technology Data Exchange (ETDEWEB)

Bergstroem, C.

1999-06-01

The way the fuel is introduced into the combustion chamber is one of the most important parameters for the power output and the generation of emissions in the combustion of liquid fuels. The interaction between the turbulent gas flow field and the liquid fuel droplets, the vaporisation of them and the mixing of the gaseous fuel with the ambient air that are vital parameters in the combustion process. The use of numerical calculations is an important tool to better understand these complex interacting phenomena. This thesis reports on the numerical modelling of fuel sprays in non-reacting cases using an own developed spray module. The spray module uses the stochastic parcel method to represent the spray. The module was made in such manner that it could by coupled with different gas flow solver. Results obtained from four different gas flow solvers are presented in the thesis, including the use of two different kinds of turbulence models. In the first part the spray module is coupled with a k-{eta} based 2-D cylindrical gas flow solver. A thorough sensitivity analysis was performed on the spray and gas flow solver parameters, such as grid size dependence and sensitivity to initial values of k-{eta}. The results of the spray module were also compared to results from other spray codes, e.g. the well known KIVA code. In the second part of this thesis the spray was injected into a turbulent and fully developed crossflow studied. The spray module was attached to a LES (Large Eddy Simulation) based flow solvers enabling the study of the complex structures and time dependent phenomena involved in spray in crossflows. It was found that the spray performs an oscillatory motion and that the Strouhal number in the wake was about 0.1. Different spray breakup models were evaluated by comparing with experimental results 66 refs, 56 figs

Application of pulse combustion technology in spray drying process

Directory of Open Access Journals (Sweden)

I. Zbicinski

2000-12-01

Full Text Available The paper presents development of valved pulse combustor designed for application in drying process and drying tests performed in a specially built installation. Laser technique was applied to investigate the flow field and structure of dispersed phase during pulse combustion spray drying process. PDA technique was used to determine initial atomization parameters as well as particle size distribution, velocity of the particles, mass concentration of liquid phase in the cross section of spray stream, etc., in the drying chamber during drying tests. Water was used to estimate the level of evaporation and 5 and 10% solutions of sodium chloride to carry out drying tests. The Computational Fluid Dynamics technique was used to perform theoretical predictions of time-dependent velocity, temperature distribution and particle trajectories in the drying chamber. Satisfactory agreement between calculations and experimental results was found in certain regions of the drying chamber.

Particle emission rates during electrostatic spray deposition of TiO2 nanoparticle-based photoactive coating

DEFF Research Database (Denmark)

Koivisto, Antti J.; Jensen, Alexander C. Ø.; Kling, Kirsten I.

2017-01-01

Here, we studied the particle release rate during Electrostatic spray deposition of anatase-(TiO2)-based photoactive coating onto tiles and wallpaper using a commercially available electrostatic spray device. Spraying was performed in a 20.3m3 test chamber while measuring concentrations of 5.6nm ...

Spray drying test of simulated borated waste solutions

International Nuclear Information System (INIS)

An Hongxiang; Zhou Lianquan; Fan Zhiwen; Sun Qi; Lin Xiaolong

2007-01-01

Performance and the effecting factors of spray drying of simulated borated waste solutions is studied for three contaeting methods between the atomized beads and the heated air, in which boron concentration is around 21000 ppm. The contacting modes are centrifugal atomizing co-current flow, pneumatic atomizing co-current flow and mixed flow. The results show that a free-flowing product in all these tests when the temperature of the solutions is between 62 degree C and 64 degree C, the inlet temperature of the spray drying chamber is between 210 degree C and 220 degree C, the temperature of the outlet of the spray drying chamber is between 110 and 120 degree C, the flow rate of the pressure air is 8.0 m 3 /h, the rotational speed of the centrifugal atomizer is 73.0 m/s. The diameters of the powder product which account for 95% of the feed range from 0.356 mm to 0.061 mm. The production capacity and water content in the powder increase in the order of pneumatic atomizing co-current flow, mixed flow and centrifugal atomizing co-current flow. The volume reduction coeffecient of spray drying is in the ranged of 0.22 and 0.27. (authors)

Coupled Lagrangian impingement spray model for doublet impinging injectors under liquid rocket engine operating conditions

Directory of Open Access Journals (Sweden)

Qiang WEI

2017-08-01

Full Text Available To predict the effect of the liquid rocket engine combustion chamber conditions on the impingement spray, the conventional uncoupled spray model for impinging injectors is extended by considering the coupling of the jet impingement process and the ambient gas field. The new coupled model consists of the plain-orifice sub-model, the jet-jet impingement sub-model and the droplet collision sub-model. The parameters of the child droplet are determined with the jet-jet impingement sub-model using correlations about the liquid jet parameters and the chamber conditions. The overall model is benchmarked under various impingement angles, jet momentum and off-center ratios. Agreement with the published experimental data validates the ability of the model to predict the key spray characteristics, such as the mass flux and mixture ratio distributions in quiescent air. Besides, impinging sprays under changing ambient pressure and non-uniform gas flow are investigated to explore the effect of liquid rocket engine chamber conditions. First, a transient impingement spray during engine start-up phase is simulated with prescribed pressure profile. The minimum average droplet diameter is achieved when the orifices work in cavitation state, and is about 30% smaller than the steady single phase state. Second, the effect of non-uniform gas flow produces off-center impingement and the rotated spray fan by 38°. The proposed model suggests more reasonable impingement spray characteristics than the uncoupled one and can be used as the first step in the complex simulation of coupling impingement spray and combustion in liquid rocket engines.

Coupled Lagrangian impingement spray model for doublet impinging injectors under liquid rocket engine operating conditions

Institute of Scientific and Technical Information of China (English)

Qiang WEI; Guozhu LIANG

2017-01-01

To predict the effect of the liquid rocket engine combustion chamber conditions on the impingement spray,the conventional uncoupled spray model for impinging injectors is extended by considering the couplingof the jet impingement process and the ambient gas field.The new coupled model consists of the plain-orifice sub-model,the jet-jet impingement sub-model and the droplet collision sub-model.The parameters of the child droplet are determined with the jet-jet impingement sub-model using correlations about the liquid jet parameters and the chamber conditions.The overall model is benchmarked under various impingement angles,jet momentum and offcenter ratios.Agreement with the published experimental data validates the ability of the model to predict the key spray characteristics,such as the mass flux and mixture ratio distributions in quiescent air.Besides,impinging sprays under changing ambient pressure and non-uniform gas flow are investigated to explore the effect of liquid rocket engine chamber conditions.First,a transient impingement spray during engine start-up phase is simulated with prescribed pressure profile.The minimum average droplet diameter is achieved when the orifices work in cavitation state,and is about 30％ smaller than the steady single phase state.Second,the effect of non-uniform gas flow produces off-center impingement and the rotated spray fan by 38°.The proposed model suggests more reasonable impingement spray characteristics than the uncoupled one and can be used as the first step in the complex simulation of coupling impingement spray and combustion in liquid rocket engines.

Molten salt hazardous waste disposal process utilizing gas/liquid contact for salt recovery

International Nuclear Information System (INIS)

Grantham, L.F.; McKenzie, D.E.

1984-01-01

The products of a molten salt combustion of hazardous wastes are converted into a cooled gas, which can be filtered to remove hazardous particulate material, and a dry flowable mixture of salts, which can be recycled for use in the molten salt combustion, by means of gas/liquid contact between the gaseous products of combustion of the hazardous waste and a solution produced by quenching the spent melt from such molten salt combustion. The process results in maximizing the proportion of useful materials recovered from the molten salt combustion and minimizing the volume of material which must be discarded. In a preferred embodiment a spray dryer treatment is used to achieve the desired gas/liquid contact

Factors affecting the development of sprays produced by multihole injectors for direct-injection engine applications

OpenAIRE

Van Romunde, R. Z.

2011-01-01

The spray form development from a state of the art multi-hole injector for gasoline direct injection internal combustion engines is examined to attempt to determine the thermo-fluid dynamics affecting the spray development. The current state of knowledge regarding spray break-up and the interactivity of the factors on spray form are detailed. The spray under investigation was injected into purposely designed quiescent chambers to decouple the effects of the fluid mechanics on s...

Fluctuations of a spray generated by an airblast atomizer

Energy Technology Data Exchange (ETDEWEB)

Batarseh, Feras Z.; Gnirss, Markus; Roisman, Ilia V.; Tropea, Cameron [Technische Universitaet Darmstadt (Germany). Chair of Fluid Mechanics and Aerodynamics

2009-06-15

This paper is devoted to the study of the aerodynamic instability of the spray generated by an airblast atomizer. As a result of this instability the spray shape and its velocity fluctuate with a certain frequency, which depends on the operational parameters of the atomizer. The effect of three parameters, namely; chamber pressure, liquid phase flow rate and the gas phase flow rate on the spray fluctuating frequency are investigated. The velocity vector of the drops in the spray and the arrival times to the detection volume are measured using the laser Doppler instrument. The slotting technique is applied to the data of axial velocity and arrival times of the drops in order to estimate the dominating spray frequencies. Additionally, the shape of the spray has been observed using the high-speed video system. The frequencies of the shape fluctuations are estimated using proper orthogonal decomposition of the time-resolved images of the spray. We show that the frequencies of the spray velocity and those exhibited by spray shape coincide over a wide range of spray parameters. Finally, a simple scaling for the spray frequency is proposed and validated by the experimental data. (orig.)

Effect of NaCl Solution Spraying on Fatigue Lives of Smooth and Slit Specimens of 0.37% Carbon Steel

Science.gov (United States)

Makabe, Chobin; Ferdous, Md. Shafiul; Shimabukuro, Akimichi; Murdani, Anggit

2017-07-01

The fatigue crack initiation life and growth rate are affected by experimental conditions. A corrosive environment can be created in a laboratory by means of dropping salt water onto the specimen surface, spraying chloride mist into the experimental chamber, etc. In the case of smooth specimens of some metals, fatigue life is shortened and the fatigue limit disappears under such corrosive experimental conditions. In this study, the effects of intermittent spraying of 3% NaCl solution-mist on corrosion fatigue behavior were investigated. The material used was 0.37% carbon steel. This is called JIS S35C in Japan. Spraying of 3% NaCl solution-mist attacked the surface layer of the specimen. It is well known that the pitting, oxidation-reduction reaction, etc. affect the fatigue strength of metals in a corrosive environment. We carried out corrosion fatigue tests with smooth specimens, holed specimens and slit specimens. Then the effects of such specimen geometry on the fatigue strength were investigated when the NaCl solution-mist was sprayed onto the specimen surface. In the case of lower stress amplitude application in slit specimens, the fatigue life in a corrosive atmosphere was longer than that in the open air. It is discussed that the behavior is related to the crack closure which happens when the oxide builds up and clogs the crack or slit.

HYLIFE-II reactor chamber mechanical design: Update

International Nuclear Information System (INIS)

House, P.A.

1992-01-01

Mechanical design features of the reactor chamber for the HYLIFE-II inertial confinement fusion power plant are presented. A combination of oscillating and steady, molten salt streams (Li 2 BeF 4 ) are used for shielding and blast protection of the chamber walls. The system is designed for a 6 Hz repetition rate. Beam path clearing, between shots, is accomplished with the oscillating flow. The mechanism for generating the oscillating streams is described. A design configuration of the vessel wall allows adequate cooling and provides extra shielding to reduce thermal stresses to tolerable levels. The bottom portion of the reactor chamber is designed to minimize splash back of the high velocity (17 m/s) salt streams and also recover up to half of the dynamic head. Cost estimates for a 1 GW e and 2 GW e reactor chamber are presented

A new method for thermal spraying of Zn-Al coatings

International Nuclear Information System (INIS)

Gorlach, I.A.

2009-01-01

This paper presents the development of the thermal spraying system built on the principles of the high velocity air flame (HVAF) process. HVAF sprayed coatings showed considerably higher bond strength than coatings obtained by the conventional methods, indicating the advantage of this method in areas where the adhesion strength is critically important. The highly dense structure of the coating obtained with HVAF eliminates a need for a top paint coat, which is typically applied on metal sprayed coatings to extend service life. The thermal sprayed coatings were characterized by the standard techniques, such as light microscopy, scanning electron microscopy with energy-dispersive spectroscopy, X-ray diffraction, salt spray and bond strength tests. The results show that thermal sprayed coatings have a dense structure, low presence of oxides and high resistance to corrosion. High spray rate and good coating quality make the HVAF thermal spray method a viable alternative to the conventional thermal spraying technologies, such as Wire Flame and Twin-Wire Arc.

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

Science.gov (United States)

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

2017-01-01

Atmospheric spray freeze-drying (ASFD) represents a novel approach to dry thermosensitive solutions via sublimation. Tests conducted with a second-generation ASFD equipment, developed for pharmaceutical applications, have focused initially on producing a light, fine, high-grade powder consistently and reliably. To better understand the heat and mass transfer physics and drying dynamics taking place within the ASFD chamber, 3 analytical models describing the key processes are developed and validated. First, by coupling the dynamics and heat transfer of single droplets sprayed into the chamber, the velocity, temperature, and phase change evolutions of these droplets are estimated for actual operational conditions. This model reveals that, under typical operational conditions, the sprayed droplets require less than 100 ms to freeze. Second, because understanding the heat transfer throughout the entire freeze-drying process is so important, a theoretical model is proposed to predict the time evolution of the chamber gas temperature. Finally, a drying model, calibrated with hygrometer measurements, is used to estimate the total time required to achieve a predefined final moisture content. Results from these models are compared with experimental data. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Numerical modelling of diesel spray using the Eulerian multiphase approach

International Nuclear Information System (INIS)

Vujanović, Milan; Petranović, Zvonimir; Edelbauer, Wilfried; Baleta, Jakov; Duić, Neven

2015-01-01

Highlights: • Numerical model for fuel disintegration was presented. • Fuel liquid and vapour were calculated. • Good agreement with experimental data was shown for various combinations of injection and chamber pressure. - Abstract: This research investigates high pressure diesel fuel injection into the combustion chamber by performing computational simulations using the Euler–Eulerian multiphase approach. Six diesel-like conditions were simulated for which the liquid fuel jet was injected into a pressurised inert environment (100% N 2 ) through a 205 μm nozzle hole. The analysis was focused on the liquid jet and vapour penetration, describing spatial and temporal spray evolution. For this purpose, an Eulerian multiphase model was implemented, variations of the sub-model coefficients were performed, and their impact on the spray formation was investigated. The final set of sub-model coefficients was applied to all operating points. Several simulations of high pressure diesel injections (50, 80, and 120 MPa) combined with different chamber pressures (5.4 and 7.2 MPa) were carried out and results were compared to the experimental data. The predicted results share a similar spray cloud shape for all conditions with the different vapour and liquid penetration length. The liquid penetration is shortened with the increase in chamber pressure, whilst the vapour penetration is more pronounced by elevating the injection pressure. Finally, the results showed good agreement when compared to the measured data, and yielded the correct trends for both the liquid and vapour penetrations under different operating conditions

Spray combustion of Jet-A and diesel fuels in a constant volume combustion chamber

KAUST Repository

Jing, Wei

2015-01-01

This work investigates the spray combustion of Jet-A fuel in an optical constant-volume combustion chamber under different ambient initial conditions. Ambient temperature was varied at 800 K, 1000 K, and 1200 K and five different ambient O2 concentrations were used, spanning 10-21%. These ambient conditions can be used to mimic practical diesel engine working conditions under different fuel injection timings and exhaust gas recirculation (EGR) levels. Both transient and quasi-steady state analyses were conducted. The transient analysis focused on the flame development from the beginning to the end of the combustion process, illustrating how the flame structure evolves with time. The quasi-steady state analysis concentrated on the stable flame structure and compared the flame emissions in terms of spatially integrated intensity, flame effective area, and intensity per pixel. The transient analysis was based on measurements using high-speed imaging of both OH∗ chemiluminescence and broadband natural luminosity (NL). For the quasi-steady state analysis, three flame narrow-band emissions (OH∗ at 310 nm, Band A at 430 nm and Band B at 470 nm) were captured using an ICCD camera. Based on the current Jet-A data and diesel data obtained from previous experiments, a comparison between Jet-A and diesel was made in terms of flame development during the transient state and spatially integrated intensity, flame effective area, and intensity per pixel during the quasi-steady state. For the transient results, Jet-A shares a similar flame development trend to diesel, but featuring a narrower region of NL and a wider region of OH∗ with the increase of ambient temperature and O2 concentration. The soot cloud is oxidized more quickly for Jet-A than diesel at the end of combustion, evident by comparing the area of NL, especially under high O2 concentration. The quasi-steady state results suggest that soot is oxidized effectively under high O2 concentration conditions by the

Salt power - Is Neptune's ole salt a tiger in the tank

Science.gov (United States)

Wick, G. S.

1980-02-01

Methods of exploiting the 24 atm osmotic pressure difference between fresh and salt water to generate energy include reverse electrodialysis, wherein 80 millivolts of electricity cross each ion-selective membrane placed between solutions of fresh and salt water. Pressure-retarded osmosis, using pumps and pressure chambers, relies on semipermeable membranes that allow fresh water to flow into saline, with power generated by the permeated water being released through a turbine. In reverse vapor compression, water vapor rapidly transfers from fresh water to salt water in an evacuated chamber (due to the vapor pressure difference between them), and power can be extracted using 24 m diameter turbine blades. Environmental concerns include protecting estuaries from stress, managing sediments, and protecting marine animals, while filtration would be needed to keep the membranes free from corrosion, biological fouling, or silting.

Temperature changes in the pulp chamber during dentin ablation with Er:YAG laser

Science.gov (United States)

Zhang, Xianzeng; Zhao, Haibin; Zhan, Zhenlin; Guo, Wenqing; Xie, Shusen

2012-12-01

To examine the temperature changes in the pulp chamber during cavity preparation in dentin with the Er:YAG laser (2940 nm), a total 20 intact premolars teeth were divided into 4 groups for dentin ablation with different radiant exposures at 4Hz and 8Hz with and without water spray. A K-type thermocouple was used to monitor the temperature changes in pulp chamber during laser treatment. The total time of irradiation was 70 sec. the water spray rate was 3 mL/min. It showed that maximum temperature rise increases with the increasing of radiant exposure and pulse repetition rate and the additional water cooling during laser ablation can significantly reduce the temperature rise in pulp chamber which will benefit to avoid or reduce thermal damage to tooth structure and dental pulp. The highest rise of temperature in the pulp was achieved with 20 J/cm2 and 8 Hz (19.83°C ). For all sample without water spray, the rise of temperature was exceed 5 °C . In contrast, with water spray, the temperature rise in the pulp can be firmly controlled under 1°C. The results also indicated that ablation rate and efficiency can be enhanced by increasing the incident radiant exposure and pulse repetition rate, which simultaneously producing more heat accumulation in dental tissue and causing thermal damage to dental tissue. By applying an additional water spray, thermal damage can be significantly reduced in clinical application.

Development and Preliminary Evaluation of a Spray Deposition Sensing System for Improving Pesticide Application.

Science.gov (United States)

Kesterson, Melissa A; Luck, Joe D; Sama, Michael P

2015-12-17

An electronic, resistance-based sensor array and data acquisition system was developed to measure spray deposition from hydraulic nozzles. The sensor surface consisted of several parallel tin plated copper traces of varying widths with varying gap widths. The system contained an embedded microprocessor to monitor output voltage corresponding to spray deposition every second. In addition, a wireless module was used to transmit the voltage values to a remote laptop. Tests were conducted in two stages to evaluate the performance of the sensor array in an attempt to quantify the spray deposition. Initial tests utilized manual droplet placement on the sensor surface to determine the effects of temperature and droplet size on voltage output. Secondary testing utilized a spray chamber to pass nozzles at different speeds above the sensor surface to determine if output varied based on different application rates or spray droplet classification. Results from this preliminary analysis indicated that manual droplets of 5 and 10 μL resulted in significantly different values from the sensors while temperature did not consistently affect output. Spray chamber test results indicated that different application rates and droplet sizes could be determined using the sensor array.

Microstructure formation and corrosion behaviour in HVOF-sprayed Inconel 625 coatings

International Nuclear Information System (INIS)

Zhang, D.; Harris, S.J.; McCartney, D.G.

2003-01-01

The nickel-based alloy Inconel 625 was thermally sprayed by two different variants of the high velocity oxy-fuel process. In this study, coatings deposited by a liquid-fuelled gun were compared with those produced by a gas-fuelled system; in general, the former generates higher particle velocities but lower particle temperatures. Investigations into the microstructural evolution of the coatings, using scanning electron microscopy and X-ray diffraction, are presented along with results on their aqueous corrosion behaviour, obtained from salt spray and potentiodynamic tests. It is inferred from coating microstructures that, during spraying, powder particles generally comprised three separate zones as follows: fully melted regions; partially melted zones; and an unmelted core. However, the relative proportions formed in an individual powder particle depended on its size, trajectory through the gun, the gas dynamics (velocity/temperature) of the thermal spray gun and the type of gun employed. Cr 2 O 3 was the principal oxide phase formed during spraying and the quantity appeared to be directly related to the degree to which particles were melted. The salt spray test provides a sensitive means of determining the presence of interconnected porosity in coatings and those produced with the liquid-fuelled gun exhibited reduced interconnected porosity and increased corrosion resistance compared with deposits obtained from the gas-fuelled system. In addition, potentiodynamic tests revealed that passive current densities are 10-20 times lower in liquid-fuel coatings than in those sprayed with the gas-fuelled gun

Size Tunable Synthesis of Highly Crystalline BaTiO3 Nanoparticles using Salt-Assisted Spray Pyrolysis

International Nuclear Information System (INIS)

Itoh, Yoshifumi; Lenggoro, I. Wuled; Okuyama, Kikuo; Maedler, Lutz; Pratsinis, Sotiris E.

2003-01-01

Highly crystalline, dense BaTiO 3 nanoparticles in a size range from 30 to 360nm with a narrow size distribution (σ g = 1.2-1.4) were prepared at various synthesis temperatures using a salt-assisted spray pyrolysis (SASP) method without the need for post-annealing. The effect of synthesis temperature on particle size, crystallinity and surface morphology of the nanoparticles were characterized by X-ray diffraction and scanning/transmission electron microscopy. The nature of the crystalline structure was analyzed by Rietveld refinement and Raman spectroscopy. The particle size decreased with decreasing operation temperature. The crystal phase was transformed from tetragonal to cubic at a particles size of about 50nm at room temperature. SASP can be used to produce high weight fraction of tetragonal BaTiO 3 nanoparticles down to 64nm in a single step

Ground experimental investigations into an ejected spray cooling system for space closed-loop application

Directory of Open Access Journals (Sweden)

Zhang Hongsheng

2016-06-01

Full Text Available Spray cooling has proved its superior heat transfer performance in removing high heat flux for ground applications. However, the dissipation of vapor–liquid mixture from the heat surface and the closed-loop circulation of the coolant are two challenges in reduced or zero gravity space environments. In this paper, an ejected spray cooling system for space closed-loop application was proposed and the negative pressure in the ejected condenser chamber was applied to sucking the two-phase mixture from the spray chamber. Its ground experimental setup was built and experimental investigations on the smooth circle heat surface with a diameter of 5 mm were conducted with distilled water as the coolant spraying from a nozzle of 0.51 mm orifice diameter at the inlet temperatures of 69.2 °C and 78.2 °C under the conditions of heat flux ranging from 69.76 W/cm2 to 311.45 W/cm2, volume flow through the spray nozzle varying from 11.22 L/h to 15.76 L/h. Work performance of the spray nozzle and heat transfer performance of the spray cooling system were analyzed; results show that this ejected spray cooling system has a good heat transfer performance and provides valid foundation for space closed-loop application in the near future.

A study on the particle melting by plasma spraying

International Nuclear Information System (INIS)

Jung, In Ha; Ji, C. G.; Bae, S. O.; Yoon, J. H.; Kwon, H. I.

2001-12-01

As a preliminary study for fabricating a thick and dense free standing type deposit, powder melting studies were carried out. Various morphologies and sizes of powder having the same chemical compositions were applied in particle melting experiments with varying systematic parameters. Through the study of powder melting by inductively coupled plasma, we can conclude as followings: Argon-hydrogen plasma gas with a higher plasma power gave good quality of splats and shown a higher density with a higher build-up rate. Reproducibility of the experiments appeared in the range of 99%. Degree of particle melting and its density just before impinging played a predominant role in the density of a deposit. Chamber pressure has an effect on degree of deformation of the splats, i.e. on the particle momentum. Completely melted particle showed a high deformation appearance. Build-up rate had a relation with a fraction of the fully melted particle, and this also closely associates with productivity and economical efficiency. For increasing the fraction of the fully melted particle, either increasing the power or limiting the particle size was recommended. Mean pore size and its distribution of a deposit seemed to have a relation with a viscosity of the melted powder, i.e. particle temperature, and also with a chamber pressure and spraying distances. Particle temperature may be governed by a plasma power, plasma gas property, probe position, and spraying distance in the present experimental range. Some results might be appeared with mutual interactions of the effects, for example, particle residence time and momentum with chamber pressure, particle temperature with chamber pressure, spraying distance and its size

A study on the particle melting by plasma spraying

Energy Technology Data Exchange (ETDEWEB)

Jung, In Ha; Ji, C. G.; Bae, S. O.; Yoon, J. H.; Kwon, H. I

2001-12-01

As a preliminary study for fabricating a thick and dense free standing type deposit, powder melting studies were carried out. Various morphologies and sizes of powder having the same chemical compositions were applied in particle melting experiments with varying systematic parameters. Through the study of powder melting by inductively coupled plasma, we can conclude as followings: Argon-hydrogen plasma gas with a higher plasma power gave good quality of splats and shown a higher density with a higher build-up rate. Reproducibility of the experiments appeared in the range of 99%. Degree of particle melting and its density just before impinging played a predominant role in the density of a deposit. Chamber pressure has an effect on degree of deformation of the splats, i.e. on the particle momentum. Completely melted particle showed a high deformation appearance. Build-up rate had a relation with a fraction of the fully melted particle, and this also closely associates with productivity and economical efficiency. For increasing the fraction of the fully melted particle, either increasing the power or limiting the particle size was recommended. Mean pore size and its distribution of a deposit seemed to have a relation with a viscosity of the melted powder, i.e. particle temperature, and also with a chamber pressure and spraying distances. Particle temperature may be governed by a plasma power, plasma gas property, probe position, and spraying distance in the present experimental range. Some results might be appeared with mutual interactions of the effects, for example, particle residence time and momentum with chamber pressure, particle temperature with chamber pressure, spraying distance and its size.

CHARACTERIZATION OF DIESEL SPRAY IMAGES USING A SHAPE PROCESSING METHODOLOGY

Directory of Open Access Journals (Sweden)

Cecile Petit

2011-05-01

Full Text Available In Diesel engines, a key element in achieving a clean and efficient combustion process is a proper fuel-air mixing, which is a consequence of the fuel spray development and fuel-air interaction inside the engine combustion chamber. The spray structure and behavior are classically described by the length (penetration and width (angle of the spray plume but these parameters do not give any clue on the geometrical injection center and on the spray symmetry. The purpose of this paper is to find out original tools to characterize the Diesel spray: the virtual spray origin is the geometrical injection center, which may (or may not coincide with the injector axis. Another interesting point is the description of the Diesel spray in terms of symmetry: the spray plume internal and external symmetry characterize the spray and the injector performance. Our approach is first to find out the virtual spray origin: after the image segmentation, the spray is coded with the Freeman code and with an original shape coding from which the moments are derived. The symmetry axes are then computed and the spray plumes are discarded (or not for the virtual spray origin computation, which is derived from a Voronoi diagram. The last step is the internal and external spray plume symmetry characterization thanks to correlation and mathematical distances.

HYLIFE-II reactor chamber mechanical design

International Nuclear Information System (INIS)

House, P.A.

1992-01-01

Mechanical design features of the reactor chamber for the HYLIFE-11 inertial confinement fusion power plant are presented. A combination of oscillating and steady, molten salt streams are used for shielding and blast protection. The system is designed for an 8 Hz repetition rate. Beam path clearing, between shots, is accomplished with the oscillating flow. The mechanism for generating the oscillating streams is described. A design configuration of the vessel wall allows adequate cooling and provides extra shielding to reduce thermal stresses to tolerable levels. The bottom portion of the reactor chamber is designed to minimize splash back of the high velocity (20 m/s) salt streams and also recover up to half of the dynamic head

Spray combustion of Jet-A and diesel fuels in a constant volume combustion chamber

International Nuclear Information System (INIS)

Jing, Wei; Roberts, William L.; Fang, Tiegang

2015-01-01

This work investigates the spray combustion of Jet-A fuel in an optical constant-volume combustion chamber under different ambient initial conditions. Ambient temperature was varied at 800 K, 1000 K, and 1200 K and five different ambient O 2 concentrations were used, spanning 10–21%. These ambient conditions can be used to mimic practical diesel engine working conditions under different fuel injection timings and exhaust gas recirculation (EGR) levels. Both transient and quasi-steady state analyses were conducted. The transient analysis focused on the flame development from the beginning to the end of the combustion process, illustrating how the flame structure evolves with time. The quasi-steady state analysis concentrated on the stable flame structure and compared the flame emissions in terms of spatially integrated intensity, flame effective area, and intensity per pixel. The transient analysis was based on measurements using high-speed imaging of both OH ∗ chemiluminescence and broadband natural luminosity (NL). For the quasi-steady state analysis, three flame narrow-band emissions (OH ∗ at 310 nm, Band A at 430 nm and Band B at 470 nm) were captured using an ICCD camera. Based on the current Jet-A data and diesel data obtained from previous experiments, a comparison between Jet-A and diesel was made in terms of flame development during the transient state and spatially integrated intensity, flame effective area, and intensity per pixel during the quasi-steady state. For the transient results, Jet-A shares a similar flame development trend to diesel, but featuring a narrower region of NL and a wider region of OH ∗ with the increase of ambient temperature and O 2 concentration. The soot cloud is oxidized more quickly for Jet-A than diesel at the end of combustion, evident by comparing the area of NL, especially under high O 2 concentration. The quasi-steady state results suggest that soot is oxidized effectively under high O 2 concentration conditions by

Spray structure of a pressure-swirl atomizer for combustion applications

Directory of Open Access Journals (Sweden)

Jicha Miroslav

2012-04-01

Full Text Available 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.

Spray structure of a pressure-swirl atomizer for combustion applications

Science.gov (United States)

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.

Spray structure of a pressure-swirl atomizer for combustion applications

OpenAIRE

Jicha Miroslav; Jedelsky Jan; Durdina Lukas

2012-01-01

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 Par...

Influence of Solvent Composition on the Performance of Spray-Dried Co-Amorphous Formulations

Directory of Open Access Journals (Sweden)

Jaya Mishra

2018-04-01

Full Text Available Ball-milling is usually used to prepare co-amorphous drug–amino acid (AA mixtures. In this study, co-amorphous drug–AA mixtures were produced using spray-drying, a scalable industrially preferred preparation method. The influence of the solvent type and solvent composition was investigated. Mixtures of indomethacin (IND and each of the three AAs arginine, histidine, and lysine were ball-milled and spray-dried at a 1:1 molar ratio, respectively. Spray-drying was performed at different solvent ratios in (a ethanol and water mixtures and (b acetone and water mixtures. Different ratios of these solvents were chosen to study the effect of solvent mixtures on co-amorphous formulation. Residual crystallinity, thermal properties, salt/partial salt formation, and powder dissolution profiles of the IND–AA mixtures were investigated and compared to pure crystalline and amorphous IND. It was found that using spray-drying as a preparation method, all IND–AA mixtures could be successfully converted into the respective co-amorphous forms, irrespective of the type of solvent used, but depending on the solvent mixture ratios. Both ball-milled and spray-dried co-amorphous samples showed an enhanced dissolution rate and maintained supersaturation compared to the crystalline and amorphous IND itself. The spray-dried samples resulting in co-amorphous samples were stable for at least seven months of storage.

No Heat Spray Drying Technology

Energy Technology Data Exchange (ETDEWEB)

Beetz, Charles [ZoomEssence, Inc., Hebron, KY (United States)

2016-06-15

No Heat Spray Drying Technology. ZoomEssence has developed our Zooming™ spray drying technology that atomizes liquids to powders at ambient temperature. The process of drying a liquid into a powder form has been traditionally achieved by mixing a heated gas with an atomized (sprayed) fluid within a vessel (drying chamber) causing the solvent to evaporate. The predominant spray drying process in use today employs air heated up to 400° Fahrenheit to dry an atomized liquid into a powder. Exposing sensitive, volatile liquid ingredients to high temperature causes molecular degradation that negatively impacts solubility, stability and profile of the powder. In short, heat is detrimental to many liquid ingredients. The completed award focused on several areas in order to advance the prototype dryer to a commercial scale integrated pilot system. Prior to the award, ZoomEssence had developed a prototype ‘no-heat’ dryer that firmly established the feasibility of the Zooming™ process. The award focused on three primary areas to improve the technology: (1) improved ability to formulate emulsions for specific flavor groups and improved understanding of the relationship of emulsion properties to final dry particle properties, (2) a new production atomizer, and (3) a dryer controls system.

MECHANICAL PROPERTIES AND CORROSION PROTECTION OF CARBON STEEL COATED WITH AN EPOXY BASED POWDER COATING CONTAINING MONTMORILONITE FUNCTIONALIZED WITH SILANE

Directory of Open Access Journals (Sweden)

Paula Tibola Bertuoli

2014-06-01

Full Text Available In the present work the MMT-Na+ clay was functionalized with 3-aminopropyltriethoxysilane (γ-APS and incorporated in a commercial formulation epoxy-based powder coating in a proportion of 8 wt% and applied on 1008 carbon steel panels by electrostatic spray. Adhesion, flexibility, impact and corrosion performance in salt spray chamber tests were performed to evaluate the coatings. The presence of clay did not affect the mechanical properties of the film, however greater subcutaneous migration was assessed after the completion of salt spray testing, which can compromise the use of paints obtained as primers.

Comparative Study of the Corrosion Resistance of Air-Plasma-Sprayed Ca2SiO4 and Al2O3 Coatings in Salt Water

Directory of Open Access Journals (Sweden)

Yuan Xiao

2018-03-01

Full Text Available In this study, Ca2SiO4 coating was sprayed on stainless steel substrate and the corrosion resistance of the as-sprayed coating was studied in salt water. At the same time, Al2O3 coatings were produced by air-plasma-sprayed technology as comparison. Immersion test was carried out to evaluate the protection performance of coatings. Potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS plots were also analyzed. The results indicated that Ca2SiO4 coatings showed a better protection performance than Al2O3 coatings. During the immersion, various calcium carbonate crystals appeared on the surface of Ca2SiO4 coatings. Ca(OH2 was released from Ca2SiO4 coatings into NaCl aqueous solution, increasing the alkalinity, which is in favor of the formation of passivation film, and thus improves the corrosion resistance. Ca2SiO4 coatings became denser after immersion due to the fact that the pores and micro cracks were filled with hydration products i.e., hydrated calcium silicate (C–S–H gel. On the contrary, the microstructure of Al2O3 coatings became loose and obvious rusty spots were observed on the surface after the immersion test.

Salt weathering in Egyptian limestone after laboratory simulations with continuous flow of salt solutions at different temperatures

Science.gov (United States)

Aly, Nevin; Gomez-Heras, Miguel; Hamed, Ayman; Alvarez de Buergo, Monica

2013-04-01

weathering in Egyptian limestone after laboratory simulations with continuous flow of salt solutions at different temperatures Nevin Aly Mohamed (1), Miguel Gomez - Heras(2), Ayman Hamed Ahmed (1), and Monica Alvarez de Buergo(2). (1) Faculty of Pet. & Min. Engineering- Suez Canal University, Suez, Egypt, (2) Instituto de Geociencias (CSIC-UCM) Madrid. Spain. Limestone is one of the most frequent building stones in Egypt and is used since the time of ancient Egyptians and salt weathering is one of the main threats to its conservation. Most of the limestone used in historical monuments in Cairo is a biomicrite extracted from the Mid-Eocene Mokattam Group. During this work, cylindrical samples (2.4 cm diameter and approx. 4.8 cm length) were subjected, in a purpose-made simulation chamber, to simulated laboratory weathering tests with fixed salt concentration (10% weight NaCl solution), at different temperatures, which were kept constant throughout each test (10, 20, 30, 40 oC). During each test, salt solutions flowed continuously imbibing samples by capilarity. Humidity within the simulation chamber was reduced using silica gel to keep it low and constant to increase evaporation rate. Temperature, humidity inside the simulation chamber and samples weight were digitally monitored during each test. Results show the advantages of the proposed experimental methodology using a continuous flow of salt solutions and shed light on the effect of temperature on the dynamics of salt crystallization on and within samples. Research funded by mission sector of high education ministry, Egypt and Geomateriales S2009/MAT-1629.

Hollow-Cone Spray Modeling for Outwardly Opening Piezoelectric Injector

KAUST Repository

Sim, Jaeheon

2016-01-04

Linear instability sheet atomization (LISA) breakup model has been widely used for modeling hollow-cone spray. However, the model was originally developed for inwardlyopening pressure-swirl injectors by assuming toroidal ligament breakups. Therefore, LISA model is not suitable for simulating outwardly opening injectors having string-like structures at wide spray angles. Furthermore, the varying area and shape of the annular nozzle exit makes the modeling difficult. In this study, a new spray modeling was proposed for outwardly opening hollow-cone injector. The injection velocities are computed from the given mas flow rate and injection pressure regardless of ambiguous nozzle exit geometries. The modified Kelvin-Helmholtz and Rayleigh-Taylor (KH-RT) breakup model is used with adjusted initial Sauter mean diameter (SMD) for modeling breakup of string-like liquid film spray. Liquid spray injection was modeled using Lagrangian discrete parcel method within the framework of commercial CFD software CONVERGE, and the detailed model was implemented by user defined functions. It was found that the new model predicted the liquid penetration length and local SMD accurately for various fuels and chamber conditions.

Economic Optimization of Spray Dryer Operation using Nonlinear Model Predictive Control

DEFF Research Database (Denmark)

Petersen, Lars Norbert; Poulsen, Niels Kjølstad; Niemann, Hans Henrik

2014-01-01

In this paper we investigate an economically optimizing Nonlinear Model Predictive Control (E-NMPC) for a spray drying process. By simulation we evaluate the economic potential of this E-NMPC compared to a conventional PID based control strategy. Spray drying is the preferred process to reduce...... the water content for many liquid foodstuffs and produces a free flowing powder. The main challenge in controlling the spray drying process is to meet the residual moisture specifications and avoid that the powder sticks to the chamber walls of the spray dryer. We present a model for a spray dryer that has...... been validated on experimental data from a pilot plant. We use this model for simulation as well as for prediction in the E-NMPC. The E-NMPC is designed with hard input constraints and soft output constraints. The open-loop optimal control problem in the E-NMPC is solved using the single...

Effect of Magnesium Salts on Growth and Production of Garlic (Allium sativum L.

Directory of Open Access Journals (Sweden)

Ikbal M. Al-Barzinji

2014-03-01

Full Text Available A Randomized Complete Block Design (R.C.B.D. experiment with three replicates was conducted to investigate the effect of foliar application of magnesium salts on growth, yield components and some inorganic minerals of leaves of garlic (Allium sativum L. local variety. The salts (MgSO4.7H2O, Mg(NO32.6H2O and MgCl2.6H2O addition to untreated plants as control. The concentration of Mg were used was constant (1.97 g Mg. L-1 which comes from 2% MgSO4.7H2O. The results revealed that vegetative growth of garlic was affected significantly by magnesium salts. Highest number of leaves was found in plants treated with MgCl2, the treatment which gave the lowest plant height, each of MgSO4 and Mg(NO32 had the highest shoot dry weight. Foliar spraying with Mg(NO32 produced highest shoot dry matter percent and highest percent of leaves Phosphorus leaves content, significantly compared to other treatments. The results showed that spraying plants with Mg(NO32 and MgSO4 improved yield components where head diameter , head weight, cloves number per head and bulbs yield were increased. Foliar spray with MgSO4 had a significant effects on head scale thickness, whereas there were non- significant effects between different Magnesium salts spraying on each of clove dry matter and percent of TSS content. This study concluded that spraying plants with MgSO4 or Mg(NO32 twice (45 days after planting and a month later increased garlic yield and yield quality.

Geotechnical investigations on backfill materials in the Asse salt mine

International Nuclear Information System (INIS)

Kappei, G.

1986-01-01

The compression behaviour of rock salt grit is being investigated by compression tests at the Asse salt mine. The various test parameters are introduced and their results are discussed. The permeability of rock salt grit with saturated NaCl-brine in dependency upon the grain size and compactness, resp. the porosity, is being determined at the Asse salt mine. The test equipment and the results determined here are shown. In addition to laboratory tests, geotechnical investigations are taking place in a carnallitic chamber of the Asse salt mine which had been backfilled in earlier years. They chiefly concern measurements of the deformation rates in drifts - which were mined between the chambers in remaining pillars - as well as horizontal deformation measurements in the backfilling. (orig./DG)

Radio frequency induction plasma spraying of molybdenum

International Nuclear Information System (INIS)

Jiang Xianliang

2003-01-01

Radio frequency (RF) induction plasma was used to make free-standing deposition of molybdenum (Mo). The phenomena of particle melting, flattening, and stacking were investigated. The effect of process parameters such as plasma power, chamber pressure, and spray distance on the phenomena mentioned above was studied. Scanning electron microscopy (SEM) was used to analyze the plasma-processed powder, splats formed, and deposits obtained. Experimental results show that less Mo particles are spheroidized when compared to the number of spheroidized tungsten (W) particles at the same powder feed rate under the same plasma spray condition. Molten Mo particles can be sufficiently flattened on substrate. The influence of the process parameters on the flattening behavior is not significant. Mo deposit is not as dense as W deposit, due to the splash and low impact of molten Mo particles. Oxidation of the Mo powder with a large particle size is not evident under the low pressure plasma spray

Effect of flame-tube head structure on combustion chamber performance

Science.gov (United States)

Gu, Minqqi

1986-01-01

The experimental combustion performance of a premixed, pilot-type flame tube with various head structures is discussed. The test study covers an extensive area: efficiency of the combustion chamber, quality of the outlet temperature field, limit of the fuel-lean blowout, ignition performance at ground starting, and carbon deposition. As a result of these tests, a nozzle was found which fits the premixed pilot flame tube well. The use of this nozzle optimized the performance of the combustion chamber. The tested models had premixed pilot chambers with two types of air-film-cooling structures, six types of venturi-tube structures, and secondary fuel nozzles with two small spray-cone angles.

Numerical analysis on the effect of swirl ratios on swirl chamber combustion system of DI diesel engines

International Nuclear Information System (INIS)

Wei, Shengli; Wang, Feihu; Leng, Xianyin; Liu, Xin; Ji, Kunpeng

2013-01-01

Highlights: • A new swirl chamber combustion system of DI diesel engines is proposed. • The appropriate vortex motion can reduce the wall concentration of mixture. • It has best emissions at swirl ratio of 0.8. • Before spray, the turbulent kinetic energy is primarily controlled by the squish. • After spray, the combustion swirl and reverse squish have a great impact on TKE. - Abstract: In order to improve the spray spatial distribution and promote the mixture quality, enhancing airflow movement in a combustion chamber, a new swirl chamber combustion system in direct injection (DI) diesel engines is proposed. The mixture formation and combustion progress in the cylinder are simulated and investigated at several different swirl ratios by using the AVL-FIRE code. The results show that in view of the fuel/air equivalence ratio distribution, the uniformity of mixture with swirl ratio of 0.2 is better. Before spray injection, the turbulent kinetic energy distribution is primarily controlled by the squish. After spray, the combustion swirl and reverse squish swirl have an effect on temperature distribution and turbulent kinetic energy (TKE) in the cylinder. The NO mass fraction is the lowest at swirl ratio of 0.8 and the highest at swirl ratio of 2.7, while Soot mass fraction is the lowest at swirl ratio of 0.2 and the highest at swirl ratio of 3.2. The appropriate swirl is benefit to improve combustion. To sum up, the emissions at swirl ratio of 0.8 has a better performance in the new combustion system

Thermal spray coating for corrosion under insulation (CUI) prevention

Science.gov (United States)

Fuad, Mohd Fazril Irfan Ahmad; Razak, Khalil Abdul; Alias, Nur Hashimah; Othman, Nur Hidayati; Lah, Nik Khairul Irfan Nik Ab

2017-12-01

Corrosion under insulation (CUI) is one of the predominant issues affecting process of Oil and Gas and Petrochemical industries. CUI refers to external corrosion, but it is difficult to be detected as the insulation cover masks the corrosion problem. One of the options to prevent CUI is by utilizing the protective coating systems. Thermal spray coating (TSC) is an advanced coating system and it shows promising performance in harsh environment, which could be used to prevent CUI. However, the application of TSC is not attractive due to the high initial cost. This work evaluates the potential of TSC based on corrosion performance using linear polarization resistance (LPR) method and salt spray test (SST). Prior to the evaluation, the mechanical performance of TSC was first investigated using adhesion test and bend test. Microstructure characterization of the coating was investigated using Scanning Electron Microscope (SEM). The LPR test results showed that low corrosion rate of 0.05 mm/years was obtained for TSC in compared to the bare steel especially at high temperature of 80 °C, where usually normal coating would fail. For the salt spray test, there was no sign of corrosion products especially at the center (fully coated region) was observed. From SEM images, no corrosion defects were observed after 336 hours of continuous exposure to salt fog test. This indicates that TSC protected the steel satisfactorily by acting as a barrier from a corrosive environment. In conclusion, TSC can be a possible solution to minimize the CUI in a long term. Further research should be done on corrosion performance and life cycle cost by comparing TSC with other conventional coating technology.

Assessment of differences between products obtained in conventional and vacuum spray dryer

Directory of Open Access Journals (Sweden)

Fernanda de Melo RAMOS

Full Text Available Abstract In this work, an experimental unit of a vacuum spray dryer was built. This prototype attempted to combine the advantages of freeze-drying (drying at low temperatures due to vacuum and spray drying (increase of surface area aiming the improvement of heat transfer efficiency. Maltodextrin solutions were dried in the vacuum operated equipment and in conventional spray dryer. The vacuum spray dryer system allowed obtaining powder at low temperatures due to the lowering of pressure conditions (2-5 kPa inside the drying chamber. The products obtained in the two systems were characterized and compared for particle size distribution, moisture content, water activity, bulk density and solubility in water. The processes yields were also evaluated and compared. The vacuum spray dryer system allowed the production of larger, more soluble and less dense particles than those obtained in the conventional configuration of the equipment, resulting in drier and, therefore, with lower water activity particles. Thus, the use of the vacuum spray dryer as a drying technique may be an alternative for the production of powder rich in thermosensitive compounds.

Conditions for the test emplacement of intermediate-level radioactive wastes in chamber 8a of the 511 m level of the Asse Salt Mine

International Nuclear Information System (INIS)

1984-01-01

The Gesellschaft fuer Strahlen- und Umweltforschung mbH (GSF) emplaces intermediate-level radioactive wastes which accumulate in an activity involving the use of radioactive materials that is licensed or reported in the Federal Republic of Germany or which are stored on an interim basis by the appropriate licensing or inspection agencies in chamber 8a of the 511 m level of the Asse Salt Mine in Remlingen near Wolfenbuettel in conjunction with an engineering test program. The type and form of the intermediate-level wastes must conform to certain conditions so that there are no hazards to personnel and the repository during transfer and subsequent storage. It is therefore necessary for the radioactive wastes to be treated and packaged before delivery in such a way that they satisfy the conditions presented in this document. The GSF shall inform the companies and organizations delivering wastes about its experiences with emplacement operations. The Conditions for the Test Emplacement of Intermediate-Level Radioactive Wastes in Chamber 8a of the 511 m Level of the Asse Salt Mine must be adapted to conform to the latest state of science and the art. The GSF must therefore reserve the right to modify the conditions, allowing for an appropriate transition period

Influence of Reduced Mass Flow Rate and Chamber Backpressure on Swirl Injector Fluid Mechanics

Science.gov (United States)

Kenny, R Jeremy; Hulka, James R.

2008-01-01

Industry interest in variable-thrust liquid rocket engines places a demand on engine injector technology to operate over a wide range of liquid mass flow rates and chamber backpressures. One injection technology of current interest for variable thrust applications is an injector design with swirled fluids. Current swirl injector design methodologies do not take into account how swirl injector design parameters respond to elevated chamber backpressures at less than design mass flow rates. The current work was created to improve state-of-the-art swirl injector design methods in this area. The specific objective was to study the effects of elevated chamber backpressure and off-design mass flow rates on swirl injector fluid mechanics. Using a backpressure chamber with optical access, water was flowed through a swirl injector at various combinations of chamber backpressure and mass flow rates. The film thickness profile down the swirl injector nozzle section was measured through a transparent nozzle section of the injector. High speed video showed measurable increases in the film thickness profile with application of chamber backpressure and mass flow rates less than design. At prescribed combinations of chamber backpressure and injected mass flow rate, a discrete change in the film thickness profile was observed. Measured injector discharge coefficient values showed different trends with increasing chamber backpressure at low mass flow rates as opposed to near-design mass flow rates. Downstream spray angles showed classic changes in morphology as the mass flow rate was decreased below the design value. Increasing chamber backpressure decreased the spray angle at any injection mass flow rate. Experimental measurements and discussion of these results are reported in this paper.

Drop formation of black liquor spraying; Mustalipeaen pisaroituminen

Energy Technology Data Exchange (ETDEWEB)

Fogelholm, C J; Kankkunen, A; Nieminen, K; Laine, J; Miikkulainen, P [Helsinki Univ. of Technology, Otaniemi (Finland): Lab. of Energy Technology and Environmental Protection

1997-10-01

Black liquor is a spent liquor of the pulp and paper industry. It is burned in kraft recovery boilers for chemical and energy recovery. The high dry solids content and viscosity of black liquor require a high spraying temperature. This affects the performance of the boiler. Kraft recovery boiler deposit formation, emissions and chemical recovery are strongly affected by the drop size and the velocity of the black liquor spray formed by a splashplate nozzle. The sheet breakup mechanism is studied with a system based on a video and image-analysis. The drop size of mill-scale nozzles was measured also with an image-analysis-system. Measurements were carried out in a spray test chamber. The sheet breakup mechanism and drop size tests were carried out both below and over the boiling point of black liquor. Special attention was paid to the effect of flashing on drop formation. Temperature increase normally decreases drop size. In the temperature where the wavy-sheet disintegration changes to perforated-sheet disintegration the drop size increases. Spray velocity rises when the temperature is increased above the boiling point. (orig.)

Controlling in situ crystallization of pharmaceutical particles within the spray dryer.

Science.gov (United States)

Woo, Meng Wai; Lee, May Ginn; Shakiba, Soroush; Mansouri, Shahnaz

2017-11-01

Simultaneous solidification and in situ crystallization (or partial crystallization) of droplets within the drying chamber are commonly encountered in the spray drying of pharmaceuticals. The crystallinity developed will determine the functionality of the powder and its stability during storage. This review discusses strategies that can be used to control the in situ crystallization process. Areas covered: The premise of the strategies discussed focuses on the manipulation of the droplet drying rate relative to the timescale of crystallization. This can be undertaken by the control of the spray drying operation, by the use of volatile materials and by the inclusion of additives. Several predictive approaches for in situ crystallization control and new spray dryer configuration strategies are further discussed. Expert opinion: Most reports, hitherto, have focused on the crystallinity of the spray dried material or the development of crystallinity during storage. More mechanistic understanding of the in situ crystallization process during spray drying is required to guide product formulation trials. The key challenge will be in adapting the mechanistic approach to the myriad possible formulations in the pharmaceutical industry.

An experimental study on atomizing formation process of diesel spray

International Nuclear Information System (INIS)

Kim, Ki Bong

2000-02-01

In this study, the experiment has, been conducted to investigate the spray characteristics under the parameter of an ambient pressure with a single hole nozzle having aspect ratio(L/D) of 5 and diameter of 0.45mm. Under the condition of the injection pressure of 14Mpa, the initial disintegrating process of a diesel spray is investigated and analysized according to change of the ambient pressures, 0.1, 1, 2 and 3Mpa. The double flash method has been employed to visualize the process of the diesel sprays. The results obtained in this study are as follows: 1) After spray starts, the spray is shown as non-disturbance liquid column within about 1∼2mm from the nozzle tip, whose diameter is similar to that of a nozzle. For the same injection pressure, the increase of the ambient pressure makes the length of the non-disturbance liquid column become short. 2) Due to the surface wave, ligaments of the shape thread appear at the boundary of liquid column right after spray. The more developed wave together the progress of spray transforms ligaments into droplets that have generally the uniformed size. 3) In case spraying into chambers having different ambient pressures, 1, 2, and 3Mpa, the spray tip velocities reach up to 1.5, 1.2, and 0.6ms, respectively, and decrease with lapse of time. The spray angle keeps increasing for 0.6, 1.2, and 1.4ms after spray under the various ambient pressures, 3, 2, and 1Mpa, respectively, and begins to decrease and maintains the constant value. Therefore, the transition points appear near the point where the velocity decreases and the spray angle increases, simultaneously. The higher ambient pressure leads to fast appearance of transition under the same spray pressure. 4) The disintegrating mechanism of the liquid spray is two combined effects: a) friction forces between the surface waves generated at the surface of the liquid column and the ambient gas, b) the collisions of liquid droplets and ligaments by spray were overtaking

Development of salt-tolerance interface for an high performance liquid chromatography/inductively coupled plasma mass spectrometry system and its application to accurate quantification of DNA samples.

Science.gov (United States)

Takasaki, Yuka; Sakagawa, Shinnosuke; Inagaki, Kazumi; Fujii, Shin-Ichiro; Sabarudin, Akhmad; Umemura, Tomonari; Haraguchi, Hiroki

2012-02-03

Accurate quantification of DNA is highly important in various fields. Determination of phosphorus by ICP-MS is one of the most effective methods for accurate quantification of DNA due to the fixed stoichiometry of phosphate to this molecule. In this paper, a smart and reliable method for accurate quantification of DNA fragments and oligodeoxythymidilic acids by hyphenated HPLC/ICP-MS equipped with a highly efficient interface device is presented. The interface was constructed of a home-made capillary-attached micronebulizer and temperature-controllable cyclonic spray chamber (IsoMist). As a separation column for DNA samples, home-made methacrylate-based weak anion-exchange monolith was employed. Some parameters, which include composition of mobile phase, gradient program, inner and outer diameters of capillary, temperature of spray chamber etc., were optimized to find the best performance for separation and accurate quantification of DNA samples. The proposed system could achieve many advantages, such as total consumption for small amount sample analysis, salt-tolerance for hyphenated analysis, high accuracy and precision for quantitative analysis. Using this proposed system, the samples of 20 bp DNA ladder (20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 300, 400, 500 base pairs) and oligodeoxythymidilic acids (dT(12-18)) were rapidly separated and accurately quantified. Copyright © 2011 Elsevier B.V. All rights reserved.

Solution synthesis of mixed-metal chalcogenide nanoparticles and spray deposition of precursor films

Science.gov (United States)

Schulz, Douglas L.; Curtis, Calvin J.; Ginley, David S.

2000-01-01

A colloidal suspension comprising metal chalcogenide nanoparticles and a volatile capping agent. The colloidal suspension is made by reacting a metal salt with a chalcogenide salt in an organic solvent to precipitate a metal chalcogenide, recovering the metal chalcogenide, and admixing the metal chalcogenide with a volatile capping agent. The colloidal suspension is spray deposited onto a substrate to produce a semiconductor precursor film which is substantially free of impurities.

Influence of the spray characteristics of a piezo-A-nozzle on the inflammation at spray guided combustion processes; Einfluss der Spraycharakteristik einer Piezo-A-Duese auf die Entflammung beim strahlgefuehrten Brennverfahren

Energy Technology Data Exchange (ETDEWEB)

Breuninger, Tobias; Schmidt, Juergen [Magdeburg Univ. (DE). Inst. fuer Stroemungstechnik und Thermodynamik (ISUT); Hese, Martin; Tschoeke, Helmut [Magdeburg Univ. (DE). Inst. fuer Mobile Systeme (IMS); Kufferath, Andreas [Robert Bosch GmbH, Schwieberdingen (Germany); Altenschmidt, Frank [Daimler AG, Stuttgart (Germany)

2011-07-01

The spray-guided combustion process offers a significant potential for improvement on the fuel consumption in partial-load engine operation. Due to the very close positioning of the injector to the spark plug, there is only very little time for the fuel mixture generation which leads to the presence of still liquid fuel particles next to already evaporized one. Furthermore the fuel-mixture generation is primarily driven by the dynamics of the fuel spray. In this article the spray characteristics of a Piezo-A-injector under pressure-chamber conditions as well as the combustion behavior on a one-cylinder test motor are analyzed. The global spray dispersion is analyzed using high-speed visualization while laser-optical measurements are used to observe the ignition-area. The mean diameter as well as the velocity of fuel droplets are determined using the phase-doppler-anemometry (PDA). An extinction-measuring methodology is used to quantify the liquid fuel particles. Analyzing the evaluated misfire-rate as a function of the spray-attributes allows for rating the spray-sections according to their ignition behavior. (orig.)

Eulerian–Lagrangian RANS Model Simulations of the NIST Turbulent Methanol Spray Flame

NARCIS (Netherlands)

Zhu, Shanglong; Roekaerts, Dirk; Pozarlik, Artur Krzysztof; van der Meer, Theodorus H.

2015-01-01

A methanol spray flame in a combustion chamber of the NIST was simulated using an Eulerian–Lagrangian RANS model. Experimental data and previous numerical investigations by other researchers on this flame were analyzed to develop methods for more comprehensive model validation. The inlet boundary

Developing Cloud Chambers with High School Students

Science.gov (United States)

Ishizuka, Ryo; Tan, Nobuaki; Sato, Shoma; Zeze, Syoji

The result and outcome of the cloud chamber project, which aims to develop a cloud chamber useful for science education is reported in detail. A project includes both three high school students and a teacher as a part of Super Science High School (SSH) program in our school. We develop a dry-ice-free cloud chamber using salt and ice (or snow). Technical details of the chamber are described. We also argue how the project have affected student's cognition, motivation, academic skills and behavior. The research project has taken steps of professional researchers, i.e., in planning research, applying fund, writing a paper and giving a talk in conferences. From interviews with students, we have learnt that such style of scientific activity is very effective in promoting student's motivation for learning science.

A multi-objective CFD optimization of liquid fuel spray injection in dry-low-emission gas-turbine combustors

International Nuclear Information System (INIS)

Asgari, Behrad; Amani, Ehsan

2017-01-01

Highlights: •An Eulerian-Lagrangian model for the fuel spray injection is evaluated. •The drop breakup, spray-vortex interaction, and wall-wetting play the key roles. •The injection location and direction are the most important parameters. •The best design candidates are proposed using multi-objective optimizations. •A large central perpendicular injection with high co-rotating swirls is optimal. -- Abstract: The main goal of this research is to investigate the effects of fuel injection strategy on the performance of the premixing chamber of modern Dry-Low-Emission (DLE) Gas-Turbine (GT) combustors. Here, an Eulerian-Lagrangian model for multi-phase multi-component flows is evaluated and used to investigate the effects of different fuel spray design parameters, including the injection location, direction, mass-flow-rate partitioning, and flow Swirl number, on the performance of the premixing chamber. The analysis is enriched by multi-objective optimizations accounting for several goals, including the evaporation efficiency, mixture stratification, entropy generation, and flow recirculation. It is observed that the droplet breakup, spray-vortex interactions, and wall-wetting have significant influences on the performance objectives while the droplet residence time effect is minor. Among the design parameters, the injection location and direction have a profound impact on the droplet breakup which predominately controls the evaporation efficiency. In addition, the interactions between the spray and the two swirling vertices inside the chamber strongly affect the mixture stratification (uniformity), e.g. the location and direction of the injection should not be chosen such that a large proportion of fuel droplets are trapped in the shear layer between the two vortices (otherwise the evaporation efficiency drops significantly) or trapped in the strong outer swirling vortex (if large mixture non-uniformity should be avoided). Finally, the best designs meeting

Evaluation of effervescent atomizer internal design on the spray unsteadiness using a phase/Doppler particle analyzer

Energy Technology Data Exchange (ETDEWEB)

Liu, Meng; Duan, YuFeng; Zhang, TieNan [School of Energy and Environment, Southeast University, Sipailou 2, Nanjing 210096 (China)

2010-09-15

The purpose of this research was to investigate the dependence of effervescent spray unsteadiness on operational conditions and atomizer internal design by the ideal spray theory of Edwards and Marx. The convergent-divergent effervescent atomizer spraying water with air as atomizing medium in the ''outside-in'' gas injection was used in this study. Results demonstrated that droplet formation process at various air to liquid ratio (ALR) led to the spray unsteadiness and all droplet size classes exhibited unsteadiness behavior in spray. The spray unsteadiness reduced quickly at ALR of 3% and decreased moderately at ALR of other values as the axial distance increased. When the axial distance was 200 mm, the spray unsteadiness reduced dramatically with the increase in radial distance, but lower spray unsteadiness at the center of spray and higher spray unsteadiness at the edge of spray were shown as the axial distance increased. The spray unsteadiness at the center region of spray increased with the injection pressure. Low spray unsteadiness and good atomization performance can be obtained when the diameter of incline aeration holes increased at ALR of 10%. Although short mixing chamber with large discharge orifice diameter for convergent-divergent effervescent atomizer produced good atomization, the center region of spay showed high spray unsteadiness and maybe formed the droplet clustering. (author)

Emulsifying salt increase stability of cheese emulsions during holding

DEFF Research Database (Denmark)

Hougaard, Anni Bygvrå; Sijbrandij, Anna G.; Varming, Camilla

2015-01-01

In cheese powder production, cheese is mixed and melted with water and emulsifying salt to form an emulsion (cheese feed) which is required to remain stable at 60°C for 1h and during further processing until spray drying. Addition of emulsifying salts ensures this, but recent demands for reduction...... of sodium and phosphate in foods makes production of cheese powder without or with minimal amounts of emulsifying salts desirable. The present work uses a centrifugation method to characterize stability of model cheese feeds. Stability of cheese feed with emulsifying salt increased with holding time at 60°C......, especially when no stirring was applied. No change in stability during holding was observed in cheese feeds without emulsifying salt. This effect is suggested to be due to continued exerted functionality of the emulsifying salt, possibly through reorganizations of the mineral balance....

Mechanisms of spray formation and combustion from a multi-hole injector with E85 and gasoline

Energy Technology Data Exchange (ETDEWEB)

Aleiferis, P.G.; Serras-Pereira, J.; van Romunde, Z. [Department of Mechanical Engineering, University College London (United Kingdom); Caine, J. [Ford Motor Company, Dunton Engineering Centre (United Kingdom); Wirth, M. [Ford Werke GmbH, Merkenich, Cologne (Germany)

2010-04-15

The spray formation and combustion characteristics of gasoline and E85 (85% ethanol, 15% gasoline) have been investigated using a multi-hole injector with asymmetric nozzle-hole arrangement. Experiments were carried out in a quiescent optical chamber using high-speed shadowgraphy (9 kHz) to characterise the spray sensitivity to both injector temperature and ambient pressure in the range of 20-120 C and 0.5, 1.0 bar. Spray-tip penetrations and 'umbrella' spray cone angles were calculated for all conditions. Phase Doppler Anemometry was also used to measure droplet sizes in the core of one of the spray plumes, 25 mm below the injector tip. To study the effect of fuel properties on vaporisation and mixture preparation under realistic operating conditions, a separate set of experiments was carried out in a direct-injection spark-ignition optical engine. The engine was run at 1500 RPM under cold and fully warmed-up conditions (20 C and 90 C) at part load and full load (0.5 and 1.0 bar intake pressure). Floodlit laser Mie-scattering images of the sprays on two orthogonal planes corresponding to the swirl and tumble planes of in-cylinder flow motion were acquired to study the full injection event and post-injection mixing stage. These were used to make comparisons with the static chamber sprays and to quantify the liquid-to-vapour phase evaporation process for both fuels by calculating the projected 'footprint' of the sprays at different conditions. Analysis of the macroscopic structure and turbulent primary break-up properties of the sprays was undertaken in light of jet exit conditions described in terms of non-dimensional numbers. The effects on stoichiometric combustion were investigated by imaging the natural flame chemiluminescence through the engine's piston crown (swirl plane) and by post-processing to derive flame growth rates and trajectories of flame motion. (author)

Experimental study of spray characteristics of biodiesel derived from waste cooking oil

International Nuclear Information System (INIS)

Mohan, Balaji; Yang, Wenming; Tay, Kun Lin; Yu, Wenbin

2014-01-01

Highlights: • B20 and diesel exhibit similar spray tip penetration and angle. • Change in orientation of spray shapes observed with different fuels. • B100 shows poor air fuel mixing compared to B20 and diesel. • Diesel shows higher equivalence ratio compared to B20 and B100. - Abstract: In this study, the fuel spray characteristics and air-fuel mixing process of waste cooking oil biodiesel (B100) and its blend with diesel (B20) were investigated and compared with diesel fuel. Spray characteristics such as spray tip penetration, spray angle, spray velocity and spray morphology were investigated under high injection and ambient pressure conditions using a constant volume spray chamber. The air-fuel mixing process was analysed using empirical relations like fuel volume, mass of air entrained within the spray and equivalence ratio. The results shows that B100 has higher spray tip penetration and velocity but narrow spray angles due to high viscosity and large momentum possessed by B100 compared to B20 and diesel fuels. The deviation in spray tip penetration reduces under high ambient pressure. The spray angle shows no change under various injection pressures; however it increases significantly under high ambient pressure. The spray shape is affected by the cavitation inside the injector nozzle holes. The fuel volume and amount of air entrainment within the spray showed that B100 exhibits poor air-fuel mixing compared to B20 and diesel fuels. Nevertheless, the equivalence ratio along the axial direction of spray reveals that the B100 has lean equivalence ratio compared to B20 and diesel fuel due to the presence of inherent oxygen content in its structure. A numerical simulation was conducted using new hybrid spray model implemented in KIVA4 and found that the results obtained from the simulation were in good agreement with the empirical results calculated from the experiments

Corrosion behaviors and effects of corrosion products of plasma electrolytic oxidation coated AZ31 magnesium alloy under the salt spray corrosion test

Science.gov (United States)

Wang, Yan; Huang, Zhiquan; Yan, Qin; Liu, Chen; Liu, Peng; Zhang, Yi; Guo, Changhong; Jiang, Guirong; Shen, Dejiu

2016-08-01

The effects of corrosion products on corrosion behaviors of AZ31 magnesium alloy with a plasma electrolytic oxidation (PEO) coating were investigated under the salt spray corrosion test (SSCT). The surface morphology, cross-sectional microstructure, chemical and phase compositions of the PEO coating were determined using scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction analysis (XRD), respectively. Further, the corrosion process of the samples under the SSCT was examined in a non-aqueous electrolyte (methanol) using electrochemical impedance spectroscopy (EIS) coupled with equivalent circuit. The results show that the inner layer of the coating was destroyed firstly and the corrosion products have significant effects on the corrosion behaviors of the coating. The results above are discussed and an electrochemical corrosion model is proposed in the paper.

Synthesis and characterization of binder-free Cr3C2 coatings on nickel-based alloys for molten fluoride salt corrosion resistance

International Nuclear Information System (INIS)

Brupbacher, Michael C.; Zhang, Dajie; Buchta, William M.; Graybeal, Mark L.; Rhim, Yo-Rhin; Nagle, Dennis C.; Spicer, James B.

2015-01-01

Under various conditions, chromium carbides appear to be relatively stable in the presence of molten fluoride salts and this suggests that their use in corrosion resistant coatings for fluoride salt environments could be beneficial. One method for producing these coatings is the carburization of sprayed Cr coatings using methane-containing gaseous precursors. This process has been investigated for the synthesis of binder-free chromium carbide coatings on nickel-based alloy substrates for molten fluoride salt corrosion resistance. The effects of the carburization process on coating microstructure have been characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) in conjunction with energy dispersive spectroscopy (EDS). Both plasma-sprayed and cold-sprayed Cr coatings have been successfully converted to Cr 3 C 2 , with the mechanism of conversion being strongly influenced by the initial porosity in the as-deposited coatings

The influence of substrate temperature and spraying distance on the properties of plasma sprayed tungsten and steel coatings deposited in a shrouding chamber

Czech Academy of Sciences Publication Activity Database

Matějíček, Jiří; Vilémová, Monika; Nevrlá, Barbara; Kocmanová, Lenka; Veverka, Jakub; Halasová, Martina; Hadraba, Hynek

2017-01-01

Roč. 318, May (2017), s. 217-223 ISSN 0257-8972. [International Meeting on Thermal Spraying (RIPT)/7./. Limoges, 09.12.2015-11.12.2015] R&D Projects: GA ČR GB14-36566G EU Projects: European Commission(XE) 633053 - EUROfusion Institutional support: RVO:61389021 ; RVO:68081723 Keywords : Tungsten * Steel * Atmospheric plasma spraying * Shrouding * Substrate temperature * Fusion reactor materials * Plasma facing components Subject RIV: JK - Corrosion ; Surface Treatment of Materials; JK - Corrosion ; Surface Treatment of Materials (UFM-A) OBOR OECD: Coating and films; Coating and films (UFM-A) Impact factor: 2.589, year: 2016 http://www.sciencedirect.com/science/ article /pii/S0257897216310520

Experimental Study on Diesel Spray Characteristics and Autoignition Process

Directory of Open Access Journals (Sweden)

Özgür Oğuz Taşkiran

2011-01-01

Full Text Available The main goal of this study is to get the temporal and spatial spray evolution under diesel-like conditions and to investigate autoignition process of sprays which are injected from different nozzle geometries. A constant volume combustion chamber was manufactured and heated internally up to 825 K at 3.5 MPa for experiments. Macroscopic properties of diesel spray were recorded via a high-speed CCD camera by using shadowgraphy technique, and the images were analyzed by using a digital image processing program. To investigate the influence of nozzle geometry, 4 different types of divergent, straight, straight-rounded, convergent-rounded nozzles, were manufactured and used in both spray evolution and autoignition experiments. The internal geometry of the injector nozzles were obtained by using silicone mold method. The macroscopic properties of the nozzles are presented in the study. Ignition behaviour of different nozzle types was observed in terms of ignition delay time and ignition location. A commercial Diesel fuel, n-heptane, and a mixture of hexadecane-heptamethylnonane (CN65—cetane number 65 were used as fuels at ignition experiments. The similar macroscopic properties of different nozzles were searched for observing ignition time and ignition location differences. Though spray and ignition characteristics revealed very similar results, the dissimilarities are presented in the study.

Plasma Spray-Physical Vapor Deposition (PS-PVD) of Ceramics for Protective Coatings

Science.gov (United States)

Harder, Bryan J.; Zhu, Dongming

2011-01-01

In order to generate advanced multilayer thermal and environmental protection systems, a new deposition process is needed to bridge the gap between conventional plasma spray, which produces relatively thick coatings on the order of 125-250 microns, and conventional vapor phase processes such as electron beam physical vapor deposition (EB-PVD) which are limited by relatively slow deposition rates, high investment costs, and coating material vapor pressure requirements. The use of Plasma Spray - Physical Vapor Deposition (PS-PVD) processing fills this gap and allows thin (deposited and multilayer coatings of less than 100 microns to be generated with the flexibility to tailor microstructures by changing processing conditions. Coatings of yttria-stabilized zirconia (YSZ) were applied to NiCrAlY bond coated superalloy substrates using the PS-PVD coater at NASA Glenn Research Center. A design-of-experiments was used to examine the effects of process variables (Ar/He plasma gas ratio, the total plasma gas flow, and the torch current) on chamber pressure and torch power. Coating thickness, phase and microstructure were evaluated for each set of deposition conditions. Low chamber pressures and high power were shown to increase coating thickness and create columnar-like structures. Likewise, high chamber pressures and low power had lower growth rates, but resulted in flatter, more homogeneous layers

Preparation and characterization of spray-dried co-amorphous drug-amino acid salts

DEFF Research Database (Denmark)

Jensen, Katrine Birgitte Tarp; Blaabjerg, Lasse Ingerslev; Lenz, Elisabeth

2016-01-01

scale. In this study, spray-drying was investigated as a scale up preparation method for co-amorphous indomethacin (IND)-amino acid mixtures. In addition, the physico-chemical properties of the different co-amorphous systems were investigated with respect to the amino acids' ability towards co...... dissolution behaviour, and physical stability at various storage conditions, were examined. KEY FINDINGS: Results showed that IND could be converted into an amorphous form in combination with the amino acids arginine (ARG), histidine (HIS) and lysine (LYS) by spray-drying. Solid state characterization...... mixtures were physically stable (>10 months) at room temperature and 40°C under dry conditions. Intrinsic dissolution of the co-amorphous mixtures showed an improved dissolution behaviour under intestinal pH conditions for IND-ARG compared with the crystalline and amorphous forms of the drug. On the other...

Fission product aerosol removal test by containment spray under accident management conditions (3)

International Nuclear Information System (INIS)

Watanabe, Atsushi; Nagasaka, Hideo; Yokobori, Seiichi; Akinaga, Makoto

2000-01-01

In order to demonstrate the effective FP aerosol removal by containment spray under Japanese AM conditions, two system integral tests and two separate effect tests were carried out using a full-height simulation test facility. In case of PWR LOCA, aerosol concentration in the upper containment vessel decreased even under low spray flow rate. In case of BWR LOCA with water injection into RPV, the aerosol concentration in the entire vessel also decreased rapidly after aerosol supply stopping. In both cases, the removal rate estimated from the NUREG-1465 was coincided with test results. The aerosol washing effect by spray was confirmed to be predominant by conducting suppression chamber isolation test. It turned out that the effect of aerosol solubility and density on aerosol removal by spray was quite small by conducting insoluble aerosol injection test. After the modification of aerosol removal model by the spray and hygroscopic aerosol model in original MELCOR 1.8.4, calculated aerosol concentration transient in the containment vessel agreed well with the test data. (author)

Simultaneous Polymerization and Polypeptide Particle Production via Reactive Spray-Drying.

Science.gov (United States)

Glavas, Lidija; Odelius, Karin; Albertsson, Ann-Christine

2016-09-12

A method for producing polypeptide particles via in situ polymerization of N-carboxyanhydrides during spray-drying has been developed. This method was enabled by the development of a fast and robust synthetic pathway to polypeptides using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as an initiator for the ring-opening polymerization of N-carboxyanhydrides. The polymerizations finished within 5 s and proved to be very tolerant toward impurities such as amino acid salts and water. The formed particles were prepared by mixing the monomer, N-carboxyanhydride of l-glutamic acid benzyl ester (NCAGlu) and the initiator (DBU) during the atomization process in the spray-dryer and were spherical with a size of ∼1 μm. This method combines two steps; making it a straightforward process that facilitates the production of polypeptide particles. Hence, it furthers the use of spray-drying and polypeptide particles in the pharmaceutical industry.

Failure Analysis of a Nickel-Plated Electronic Connector Due to Salt-Induced Corrosion (ENGE 2014).

Science.gov (United States)

Lee, Na-Ri; Choi, Hyoung-Seuk; Choi, Duck-Kyun

2015-10-01

When electronic connectors in mobile devices are miniaturized, the thickness of plating decreases. However, this thin plating is expected to decrease the life of the connector due to problems with corrosion. In this study, salt spray aging tests were performed on miniaturized nickel-plated stainless steel electronic connectors to observe failure mechanisms in realistic environments. The tests were performed three times using a 5% NaCl solution in an atmosphere of 45 °C; each test included several cycles where one cycle was one 24-h period consisting of 8 h of salt spray and 16 h without salt spray. The nickel-plating layers were periodically observed by electron probe X-ray micro-analyzer, wavelength dispersive spectroscopy, and field-emission scanning electron microscopy to analyze and identify the corrosion mechanism. We found that the primary failure mode of the nickel plating is blistering and delamination. The corrosion mechanism is typically a chain reaction of several corrosion mechanisms: pitting corrosion --> stress corrosion cracking --> hydrogen-induced cracking --> blistering and delamination. Finally, we discuss countermeasures to prevent corrosion of the nickel layer based on the corrosion mechanisms identified in this study.

Spray-coated ligand-free Cu2ZnSnS4 nanoparticle thin films

DEFF Research Database (Denmark)

Engberg, Sara Lena Josefin; Murthy, Swathi; Kofod, Guggi

We have fabricated Cu2ZnSnS4 (CZTS) thin films from spray-coating ligand-free nanoparticle inks. The as-synthesized CZTS nanoparticles were inherently ligand-free [1], which allows the use of polar solvents, such as water and ethanol. Another advantage of these particles is that user- and environ......We have fabricated Cu2ZnSnS4 (CZTS) thin films from spray-coating ligand-free nanoparticle inks. The as-synthesized CZTS nanoparticles were inherently ligand-free [1], which allows the use of polar solvents, such as water and ethanol. Another advantage of these particles is that user......- and environmentally-friendly alkali metal chloride salts can be directly dissolved in controllable amounts. The homogeneous distribution of alkali metals in the ink allows uniform grain growth within the deposited absorber layer as a result of liquid phase assisted sintering. We find that particularly beneficial...... as an unquantifiable amount of ZnS. A Sono-tek spray-coating system is used which utilizes ultrasonic atomization. We investigate the effect of different binders, ink concentration, and spray-coating conditions, i.e. spray power, flow rate from syringe pump, distance between spray nozzle and the substrate, and time...

Optimization of combustion chamber geometry for natural gas engines with diesel micro-pilot-induced ignition

International Nuclear Information System (INIS)

Wang, Bin; Li, Tie; Ge, Linlin; Ogawa, Hideyuki

2016-01-01

Highlights: • Combustion chamber geometry is optimized to reduce the HC/CO emissions. • CFD model is calibrated against the spray visualization and engine bench test data. • Design space is explored by the multi-objective NSGA-II with Kriging meta-model. • HC and CO emissions are respectively reduced by 56.47% and 33.55%. - Abstract: Smokeless, low nitrogen oxides (NOx), and high thermal efficiency have been achieved through the lean-burn concept for natural gas engine with diesel micro-pilot-induced ignition (MPII). However, the combustion chamber is usually not specialized for natural gas combustion, and increases in the unburned hydrocarbon (HC) and carbon monoxide (CO) emissions are still a challenge for this type of engines. This paper describes optimization of the combustion chamber geometry to reduce the HC and CO emissions and improve the combustion efficiency in the MPII natural gas engine. The 3-D computational fluid dynamics (CFD) simulation model coupled with a chemical reaction mechanism is described. The temporal development of the short-pulsed diesel spray in a high pressure constant-volume vessel is measured and used to calibrate the spray model in the CFD simulation. The simulation models are validated by the experimental data of the in-cylinder pressure trace, apparent heat release rate (AHRR) and exhaust gas emissions from a single-cylinder MPII natural gas engine. To generate the various combustion chamber geometries, the bowl outline is parameterized by the two cubic Bezier curves while keeping the compression ratio constant. The available design space is explored by the multi-objective non-dominated sorting genetic algorithm II (NSGA-II) with Kriging-based meta-model. With the optimization, the HC and CO emissions are reduced by 56.47% and 33.55%, respectively, while the NOx emissions, the maximum rate of pressure rise and the gross indicated thermal efficiency that are employed as the constraints are slightly improved. Finally, the

Formation of hydrotalcite coating on the aluminum alloy 6060 in spray system

DEFF Research Database (Denmark)

Zhou, Lingli; Friis, Henrik; Roefzaad, Melanie

2016-01-01

Coatings with the composition of Li-Al-NO3 hydrotalcite were formed on the Al alloy 6060 using a spray system. The coatings consist of crystals with a typical hydrotalcite structure. Dense, uniform and blade-like flakes cover completely the surface of the Al substrate. The coatings display a multi......-layer structure with average thickness of ∼1000 nm. The hydrotalcite-coated samples performed better than those without coatings in salt-spray and filiform-corrosion tests, and further treatment involving sealing with a Mg acetate solution and dipping in a H2O2 + Ce-based solution improved the corrosion...

Study of air entrainment in high pressure spray: optics diagnostics and application to the Diesel injection; Etude de l'entrainement d'air dans un spray haute pression: diagnostics optiques et application a l'injection diesel

Energy Technology Data Exchange (ETDEWEB)

Arbeau, A.

2004-12-15

The actual development of the engine must reply to a will of fuel consumption reduction and to norms more and more strict concerning the pollutant emissions. Although the Diesel engines are efficient, the NO{sub x} and particle emissions mainly come from the existence of wealthy fuel zone preventing an optimal combustion. Therefore, the air / fuel mixing preparation, highly controlled by the air entrainment in spray, is essential. In this context, we have developed metrological tools in order to analyse the air entrainment mechanism in a dense spray. The Particle Image Velocimetry (PIV) technique is first applied to a conical spray with an injection pressure less than 100 bars to study the air entrainment in spray. A transfer of the methodologies allows then the characterisation and the understanding of the air entrainment mechanism in high pressure full spray (injection pressure less than 1600 bars) type Diesel one. The influence of injection parameters (injection pressure and back pressure) on the mixing rate is studied. The increase of the injection pressure from 800 to 1600 bars implies an increase of the mixing rate of 60 %. Moreover, the thermodynamic conditions of the ambient air, simulated by the chamber back pressure, widely favours the mixing rate. Actually, this latter increases of 350 % when the chamber back pressure varies from 1 to 7 bars. The experimental results do not follow classical laws of air entrainment in one-phase flow jet with variable density, but are in good agreement with an integral model for air entrainment in an axisymmetric full spray. Finally, the Fluorescence Particle Image Velocimetry (FPIV) is introduced in order to extend the PIV application field in dense two-phase flows. (author)

The influence of spill-line geometry on a spray generated by a pressure-swirl atomizer

Directory of Open Access Journals (Sweden)

Malý Milan

2016-01-01

Full Text Available An experimental investigation of characteristics of spray generated by a pressure-swirl atomizer (spill-return type was performed using shadowgraphy and Phase-Doppler Anemometry (PDA. Several different geometries of the spill-return orifice were tested in terms of a spray stability and quality on a cold test bench. PDA measurement yields a drop-size distribution and velocity data while the shadowgraphy unveils a break-up process in detail. Performed measurements reveal significant differences in spray characteristics as well as differences in spray stability. The results suggest that the air core, formed inside the swirl chamber, passes through the spill orifice, which causes instability of the inner flow. These instabilities lead to a chaotic state of sheet breakup resulting in shortening of breakup distance. Obtained findings are used to propose possible changes in the atomizer design for improvement of its performance.

The influence of spill-line geometry on a spray generated by a pressure-swirl atomizer

Science.gov (United States)

Malý, Milan; Janáčková, Lada; Jedelský, Jan; Jícha, Miroslav

2016-03-01

An experimental investigation of characteristics of spray generated by a pressure-swirl atomizer (spill-return type) was performed using shadowgraphy and Phase-Doppler Anemometry (PDA). Several different geometries of the spill-return orifice were tested in terms of a spray stability and quality on a cold test bench. PDA measurement yields a drop-size distribution and velocity data while the shadowgraphy unveils a break-up process in detail. Performed measurements reveal significant differences in spray characteristics as well as differences in spray stability. The results suggest that the air core, formed inside the swirl chamber, passes through the spill orifice, which causes instability of the inner flow. These instabilities lead to a chaotic state of sheet breakup resulting in shortening of breakup distance. Obtained findings are used to propose possible changes in the atomizer design for improvement of its performance.

Spray combustion of biomass-based renewable diesel fuel using multiple injection strategy in a constant volume combustion chamber

KAUST Repository

Jing, Wei

2016-05-26

Effect of a two-injection strategy associated with a pilot injection on the spray combustion process was investigated under conventional diesel combustion conditions (1000 K and 21% O2 concentration) for a biomass-based renewable diesel fuel, i.e., biomass to liquid (BTL), and a regular No. 2 diesel in a constant volume combustion chamber using multiband flame measurement and two-color pyrometry. The spray combustion flame structure was visualized by using multiband flame measurement to show features of soot formation, high temperature and low temperature reactions, which can be characterized by the narrow-band emissions of radicals or intermediate species such as OH, HCHO, and CH. The objective of this study was to identify the details of multiple injection combustion, including a pilot and a main injection, and to provide further insights on how the two injections interact. For comparison, three injection strategies were considered for both fuels including a two-injection strategy (Case TI), single injection strategy A (Case SA), and single injection strategy B (Case SB). Multiband flame results show a strong interaction, indicated by OH emissions between the pilot injection and the main injection for Case TI while very weak connection is found for the narrow-band emissions acquired through filters with centerlines of 430 nm and 470 nm. A faster flame development is found for the main injection of Case TI compared to Cases SA and SB, which could be due to the high temperature environment and large air entrainment from the pilot injection. A lower soot level is observed for the BTL flame compared to the diesel flame for all three injection types. Case TI has a lower soot level compared to Cases SA and SB for the BTL fuel, while the diesel fuel maintains a similar soot level among all three injection strategies. Soot temperature of Case TI is lower for both fuels, especially for diesel. Based on these results, it is expected that the two-injection strategy could be

MECHANICAL PROPERTIES AND CORROSION PROTECTION OF CARBON STEEL COATED WITH AN EPOXY BASED POWDER COATING CONTAINING MONTMORILONITE FUNCTIONALIZED WITH SILANE

OpenAIRE

Paula Tibola Bertuoli; Veronica Perozzo Frizzo; Diego Piazza; Lisete Cristine Scienza; Ademir José Zattera

2014-01-01

In the present work the MMT-Na+ clay was functionalized with 3-aminopropyltriethoxysilane (γ-APS) and incorporated in a commercial formulation epoxy-based powder coating in a proportion of 8 wt% and applied on 1008 carbon steel panels by electrostatic spray. Adhesion, flexibility, impact and corrosion performance in salt spray chamber tests were performed to evaluate the coatings. The presence of clay did not affect the mechanical properties of the film, however greater subcutaneo...

Alleviation of salt stress in lemongrass by salicylic acid.

Science.gov (United States)

Idrees, Mohd; Naeem, M; Khan, M Nasir; Aftab, Tariq; Khan, M Masroor A; Moinuddin

2012-07-01

Soil salinity is one of the key factors adversely affecting the growth, yield, and quality of crops. A pot study was conducted to find out whether exogenous application of salicylic acid could ameliorate the adverse effect of salinity in lemongrass (Cymbopogon flexuosus Steud. Wats.). Two Cymbopogon varieties, Krishna and Neema, were used in the study. Three salinity levels, viz, 50, 100, and 150 mM of NaCl, were applied to 30-day-old plants. Salicylic acid (SA) was applied as foliar spray at 10(-5) M concentration. Totally, six SA-sprays were carried out at 10-day intervals, following the first spray at 30 days after sowing. The growth parameters were progressively reduced with the increase in salinity level; however, growth inhibition was significantly reduced by the foliar application of SA. With the increase in salt stress, a gradual decrease in the activities of carbonic anhydrase and nitrate reductase was observed in both the varieties. SA-treatment not only ameliorated the adverse effects of NaCl but also showed a significant improvement in the activities of these enzymes compared with the untreated stressed-plants. The plants supplemented with NaCl exhibited a significant increase in electrolyte leakage, proline content, and phosphoenol pyruvate carboxylase activity. Content and yield of essential oil was also significantly decreased in plants that received salinity levels; however, SA overcame the unfavorable effects of salinity stress to a considerable extent. Lemongrass variety Krishna was found to be more adapted to salt stress than Neema, as indicated by the overall performance of the two varieties under salt conditions.

Applicability of fan spray nozzles to stripping insoluble gases from viscous liquids

International Nuclear Information System (INIS)

Tseng, H.H.; Johnson, E.F.

1983-08-01

Fan spray nozzle stripping appears to be a practical technique for separating dilute volatile solutes from nonvolatile solvents. In particular this technique can be used to strip molecular tritium and tritium fluoride at extremely small concentration (in the parts per million range) from molten salts used as blanket materials in a fusion reactor. Under adjusted operating conditions of the fan spray as it leaves the nozzle, a high percentage of the theoretically maximum achievable stripping would take place from the expanding sheet of the fan spray as it leaves the nozzle and before it breaks up. Although the only available experimental data are for aqueous solutions, a new theoretical analysis of the fan spray sheet demonstrates the applicability of this technique to nonaqueous liquids. The equation derived from this analysis relates the theoretically achievable mass transfer efficiency to the properties of the liquid flowing through the fan spray nozzle and to the operating conditions of the nozzle. Any fluid with viscosity higher than or equal to that of water would be expected to follow this equation as long as a fan-shaped sheet is formed under the operating conditions of the nozzle

An indoor air quality evaluation in a residential retrofit project using spray polyurethane foam.

Science.gov (United States)

Tian, Shen; Ecoff, Scott; Sebroski, John; Miller, Jason; Rickenbacker, Harold; Bilec, Melissa

2018-05-01

Understanding of indoor air quality (IAQ) during and after spray polyurethane foam (SPF) application is essential to protect the health of both workers and building occupants. Previous efforts such as field monitoring, micro-chamber/spray booth emission studies, and fate/transport modeling have been conducted to understand the chemical exposure of SPF and guide risk mitigation strategies. However, each type of research has its limitation and can only reveal partial information on the relationship between SPF and IAQ. A comprehensive study is truly needed to integrate the experimental design and analytical testing methods in the field/chamber studies with the mathematical tools employed in the modeling studies. This study aims to bridge this gap and provide a more comprehensive understanding on the impact of SPF to IAQ. The field sampling plan of this research aims to evaluate the airborne concentrations of methylene diphenyl diisocyanate (MDI), formaldehyde, acetaldehyde, propionaldehyde, tris(1-chlor-2-propyl)phosphate (TCPP), trans-1-chloro-3,3,3-trifluoropropene (Solstice TM ), and airborne particles. Modifications to existing MDI sampling and analytical methods were made so that level of quantification was improved. In addition, key fate and transport modeling input parameters such as air changes per hour and airborne particle size distribution were measured. More importantly, TCPP accumulation onto materials was evaluated, which is important to study the fate and transport of semi-volatile organic compounds. The IAQ results showed that after spray application was completed in the entire building, airborne concentrations decreased for all chemicals monitored. However, it is our recommendation that during SPF application, no one should return to the application site without proper personal protection equipment as long as there are active spray activities in the building. The comparison between this field study and a recent chamber study proved surface sorption

Effects of ambient oxygen concentration on soot temperature and concentration for biodiesel and diesel spray combustion

KAUST Repository

Zhang, Ji; Jing, Wei; Roberts, William L.; Fang, Tiegang

2015-01-01

during biodiesel and diesel spray combustion. The experiment was implemented in a constant volume chamber system, where the ambient oxygen concentration varied from 21 to 10% and the ambient temperature was kept to 1,000 K. A high speed two-color

Improvement of wear resistance of machine elements by plasma spraying followed by hardening in the chlorine-barium melt

International Nuclear Information System (INIS)

Fominykh, V.V.; Stepanov, V.V.

1979-01-01

Proposed is the mathematical model, allowing to choose the optimal regime of sprayed coating hardening in the BaCl 2 salt melt. The method of hardening of machine elements by spraying wear resistance coatings of the Ni-Cr-B-Si alloys is described. It is established that diffusion heating followed by coating melting in the BaCl 2 solution increases the adhesion of sprayed layer to substrate metal. The formation of intermediate intermetallic compounds of the Ni 3 Si and Ni 3 Fe types takes place as a result of diffusion of interacting material atoms and valence electron joining

Modification of the solid-state nature of sulfathiazole and sulfathiazole sodium by spray drying.

Science.gov (United States)

Bianco, Stefano; Caron, Vincent; Tajber, Lidia; Corrigan, Owen I; Nolan, Lorraine; Hu, Yun; Healy, Anne Marie

2012-06-01

Solid-state characterisation of a drug following pharmaceutical processing and upon storage is fundamental to successful dosage form development. The aim of the study was to investigate the effects of using different solvents, feed concentrations and spray drier configuration on the solid-state nature of the highly polymorphic model drug, sulfathiazole (ST) and its sodium salt (STNa). The drugs were spray-dried from ethanol, acetone and mixtures of these organic solvents with water. Additionally, STNa was spray-dried from pure water. The physicochemical properties including the physical stability of the spray-dried powders were compared to the unprocessed materials. Spray drying of ST from either acetonic or ethanolic solutions with the spray drier operating in a closed cycle mode yielded crystalline powders. In contrast, the powders obtained from ethanolic solutions with the spray drier operating in an open cycle mode were amorphous. Amorphous ST crystallised to pure form I at ≤35 % relative humidity (RH) or to polymorphic mixtures at higher RH values. The usual crystal habit of form I is needle-like, but spherical particles of this polymorph were generated by spray drying. STNa solutions resulted in an amorphous material upon processing, regardless of the solvent and the spray drier configuration employed. Moisture induced crystallisation of amorphous STNa to a sesquihydrate, whilst crystallisation upon heating gave rise to a new anhydrous polymorph. This study indicated that control of processing and storage parameters can be exploited to produce drugs with a specific/desired solid-state nature.

Water Spray Flow Characteristics Under Synthetic Jet Driven By a Piezoelectric Actuator

Science.gov (United States)

Marchitto, L.; Valentino, G.; Chiatto, M.; de Luca, L.

2017-01-01

Particle Image Velocimetry (PIV) and Phase Doppler Anemometry (PDA) have been applied to investigate the droplets size and velocity distribution of a water spray, under the control of a piezo-element driven synthetic jet (SJ). Tests were carried out under atmospheric conditions within a chamber test rig equipped with optical accesses at two injection pressures, namely 5 and 10 MPa, exploring the variation of the main spray parameters caused by the synthetic jet perturbations. The SJ orifice has been placed at 45° with respect to the water spray axis; the nozzle body has been moved on its own axis and three different nozzle quotes were tested. PIV measurements have been averaged on 300 trials whereas about 105 samples have been acquired for the PDA tests. For each operative condition, the influence region of the SJ device on the spray has been computed through a T-Test algorithm. The synthetic jet locally interacts with the spray, energizing the region downstream the impact. The effect of the actuator decreases at higher injection pressures and moving the impact region upwards. Droplets coalescence can be detected along the synthetic jet axis, while no significant variations are observed along a direction orthogonal to it.

Simultaneous two-phase flow measurement of spray mixing process by means of high-speed two-color PIV

International Nuclear Information System (INIS)

Zhang, Ming; Xu, Min; Hung, David L S

2014-01-01

In this article, a novel high-speed two-color PIV optical diagnostic technique has been developed and applied to simultaneously measure the velocity flow-fields of a multi-hole spark-ignition direct injection (SIDI) fuel injector spray and its ambient gas in a high-pressure constant volume chamber. To allow for the phase discrimination between the fuel droplets and ambient gas, a special tracer-filter system was designed. Fluorescent seeding particles with Sauter mean diameter (SMD) of 4.8 µm were used to trace the gas inside the chamber. With a single high-speed Nd:YLF laser sheet (527 nm) as the incident light source, the Mie-scattering signal marked the phase of the fuel spray, while the fluorescent signal generated from the seeding particles tracked the phase of ambient gas. A high-speed camera, with an image-doubler (mounted in front of the camera lens) that divided the camera pixels into two parts focusing on the same field of view, was used to collect the Mie-scattering signal and LIF (laser induced fluorescence) signal simultaneously with two carefully selected optical filters. To accommodate the large dynamic range of velocities in the two phases (1–2 orders of magnitude difference), two separation times (dt) were introduced. This technique was successfully applied to the liquid spray and ambient gas two-phase flow measurement. The measurement accuracy was compared with those from LDV (laser Doppler velocimetry) measurement and good agreement was obtained. Ambient gas motion surrounding the fuel spray was investigated and characterized into three zones. The momentum transfer process between the fuel spray and ambient gas in each zone was analyzed. The two-phase flow interaction under various superheated conditions was investigated. A strengthened momentum transfer from the liquid spray to the ambient was observed with increased superheat degree. (paper)

Predictive factors for anterior chamber fibrin formation after vitreoretinal surgery

Directory of Open Access Journals (Sweden)

Leonardo Provetti Cunha

2014-04-01

Full Text Available Purpose: The aim of this study was to investigate possible predictive factors related to anterior chamber fibrin formation after vitreoretinal surgery in a large series of patients. Methods: The data of 185 eyes of 185 patients submitted to vitreoretinal surgery was reviewed. The following variables were evaluated: the postoperatively presence of fibrin, age, diabetes mellitus, the vitrectomy system gauge (20, 23 or 25 gauge, the type of vitreous substitute, the influence of prior surgical procedures and the combination with cataract extraction. To evaluate predictive factors for anterior chamber fibrin formation, univariate analysis was performed. A multivariate stepwise logistic regression model was adjusted to investigate factors associated with fibrin formation (p<0.05. Results: Fibrinoid anterior chamber reaction was found in 12 (6.4% patients. For multivariate logistic regression analysis, balanced salt solution (BSS, the chance of fibrin occurrence was 5 times greater (odds ratio 4.83, CI 95% 1.302 - 17.892; p=0.019, while combination with phacoemulsification increased the chance of fibrin formation by 20 times (odds ratio 20, CI 95% 2.480 - 161.347; p=0.005. No significant difference was found regarding other variables. Conclusion: Anterior chamber fibrin formation is an unwanted complication after vitreoretinal surgery. Factors such as combined performance of phacoemulsification and the use of balanced salt solution as a vitreous substitute may predispose the occurrence of this complication.

Spray characterization of a piezo pintle-type injector for gasoline direct injection engines

Science.gov (United States)

Nouri, J. M.; Hamid, M. A.; Yan, Y.; Arcoumanis, C.

2007-10-01

The sprays from a pintle-type nozzle injected into a constant volume chamber have been visualised by a high resolution CCD camera and quantified in terms of droplet velocity and diameter with a 2-D phase Doppler anemometry (PDA) system at an injection pressure of 200 bar and back-pressures varying from atmospheric to 12 bar. Spray visualization illustrated that the spray was string-structured, that the location of the strings remained constant from one injection to the next and that the spray structure was unaffected by back pressure. The overall spray cone angle was also stable and independent of back pressure whose effect was to reduce the spray tip penetration so that the averaged vertical spray tip velocity was reduced by 37% when the back-pressure increased from 1 to 12 bar. Detailed PDA measurements were carried out under atmospheric conditions at 2.5 and 10 mm from the injector exit with the results providing both the temporal and the spatial velocity and size distributions of the spray droplets. The maximum axial mean droplet velocity was 155 m/s at 2.5 mm from the injector which was reduced to 140 m/s at z = 10 mm. The string spacing determined from PDA measurements was around 0.375 mm and 0.6 mm at z=2.5 and 10 mm, respectively. The maximum mean droplet diameter was found to be in the core of the strings with values up to 40 μm at z=2.5 mm reducing to 20 μm at z=10 mm.

Spray characterization of a piezo pintle-type injector for gasoline direct injection engines

International Nuclear Information System (INIS)

Nouri, J M; Hamid, M A; Yan, Y; Arcoumanis, C

2007-01-01

The sprays from a pintle-type nozzle injected into a constant volume chamber have been visualised by a high resolution CCD camera and quantified in terms of droplet velocity and diameter with a 2-D phase Doppler anemometry (PDA) system at an injection pressure of 200 bar and back-pressures varying from atmospheric to 12 bar. Spray visualization illustrated that the spray was string-structured, that the location of the strings remained constant from one injection to the next and that the spray structure was unaffected by back pressure. The overall spray cone angle was also stable and independent of back pressure whose effect was to reduce the spray tip penetration so that the averaged vertical spray tip velocity was reduced by 37% when the back-pressure increased from 1 to 12 bar. Detailed PDA measurements were carried out under atmospheric conditions at 2.5 and 10 mm from the injector exit with the results providing both the temporal and the spatial velocity and size distributions of the spray droplets. The maximum axial mean droplet velocity was 155 m/s at 2.5 mm from the injector which was reduced to 140 m/s at z = 10 mm. The string spacing determined from PDA measurements was around 0.375 mm and 0.6 mm at z=2.5 and 10 mm, respectively. The maximum mean droplet diameter was found to be in the core of the strings with values up to 40 μm at z=2.5 mm reducing to 20 μm at z=10 mm

An experimental setup for the study of the steady air flow in a diesel engine chamber

Directory of Open Access Journals (Sweden)

Montanero José María

2012-04-01

Full Text Available We present an experimental setup for studying the steady air flow in a diesel engine chamber. An engine block containing the inlet manifold was placed on a test bench. A steady air stream crossed the inlet manifold and entered a glass chamber driven by a fan. A PIV system was set up around the bench to measure the in-chamber flow. An air spray gun was used as seed generator to producing sub-millimeter droplets, easily dragged by the air stream. Images of the in-flow chamber were acquired in the course of the experiments, and processed to measure the velocity field. The pressure drop driven the air current and the mass flow rate were also measured.

The effect of processing parameters on plasma sprayed beryllium for fusion applications

International Nuclear Information System (INIS)

Castro, R.G.; Stanek, P.W.; Jacobson, L.A.; Cowgill, D.F.; Snead, L.L.

1993-01-01

Plasma spraying is being investigated as a potential coating technique for applying thin (0.1--5mm) layers of beryllium on plasma facing surfaces of blanket modules in ITER and also as an in-situ repair technique for repairing eroded beryllium surfaces in high heat flux divertor regions. High density spray deposits (>98% of theoretical density) of beryllium will be required in order to maximize the thermal conductivity of the beryllium coatings. A preliminary investigation was done to determine the effect of various processing parameters (particle size, particle morphology, secondary gas additions and reduced chamber pressure) on the as-deposited density of beryllium. The deposits were made using spherical beryllium feedstock powder which was produced by centrifugal atomization at Los Alamos National Laboratory (LANL). Improvements in the as-deposited densities and deposit efficiencies of the beryllium spray deposits will be discussed along with the corresponding thermal conductivity and outgassing behavior of these deposits

The effect of processing parameters on plasma sprayed beryllium for fusion applications

International Nuclear Information System (INIS)

Castro, R.G.; Stanek, P.W.; Jacobson, L.W.; Cowgill, D.F.

1993-01-01

Plasma spraying is being investigated as a potential coating technique for applying thin (0.1-5mm) layers of beryllium on plasma facing surfaces of blanket modules in ITER and also as an in-situ repair technique for repairing eroded beryllium surfaces in high heat flux divertor regions. High density spray deposits (>98% of theoretical density) of beryllium will be required in order to maximize the thermal conductivity of the beryllium coatings. A preliminary investigation was done to determine the effect of various processing parameters (particle size, particle morphology, secondary gas additions and reduced chamber pressure) on the as-deposited density of beryllium. The deposits were made using spherical beryllium feedstock powder which was produced by centrifugal atomization at Los Alamos National Laboratory (LANL). Improvements in the as-deposited densities and deposit efficiencies of the beryllium spray deposits will be discussed along with the corresponding thermal conductivity and outgassing behavior of these deposits. (orig.)

Experimental investigation concerning the influence of fuel type and properties on the injection and atomization of liquid biofuels in an optical combustion chamber

International Nuclear Information System (INIS)

Galle, J.; Defruyt, S.; Van de Maele, C.; Rodriguez, R. Piloto; Denon, Q.; Verliefde, A.; Verhelst, S.

2013-01-01

Due to the scarcity of fossil fuels and the future stringent emission limits, there is an increasing interest for the use of renewable biofuels in compression ignition engines. However, these fuels have different physical, chemical and thermodynamic properties affecting atomization, spray development and combustion processes. The results reported in this paper have been obtained by experimentation with a constant volume combustion chamber. The influences of physical fuel properties on injections under non-evaporating conditions are studied, using a pump-line-nozzle system from a medium speed diesel engine with injection pressures up to 1200 bar, by changing the fuel type and temperature. Experiments were conducted for diesel, biodiesel, straight vegetable oils and animal fats. Injection pressure and needle lift measurements were analyzed. A high speed camera was used to visualize the spray, which enabled us to study the spray penetration and spray angle. Our results show that the fuel temperature is an important parameter to control because it significantly affects the fuel properties. Both the injection timing and injection duration are affected by the fuel properties. The influences of these properties on the spray development were less pronounced. At low temperatures, a strongly deteriorated atomization of oils and fats was observed. -- Highlights: • Spray measurements in an optical combustion chamber. • Influence on the injections system is compared for different bio-fuels. •Temperature effects the fuel properties, with strong influence on the injection system. • Viscosity has significant influence on atomization, especially for viscous fuels. • No difference for spray penetration and angle unlike the mass distribution

Chamber for Aerosol Deposition of Bioparticles

Science.gov (United States)

Kern, Roger; Kirschner, Larry

2008-01-01

accumulation of electric charge on them, they are spray-coated with an anti-static material. During use, the base plate and the sides and top of the chamber are grounded as a further measure to minimize the buildup of electric charge.

The effect of nozzle diameter, injection pressure and ambient temperature on spray characteristics in diesel engine

Science.gov (United States)

Rhaodah Andsaler, Adiba; Khalid, Amir; Sharifhatul Adila Abdullah, Nor; Sapit, Azwan; Jaat, Norrizam

2017-04-01

Mixture formation of the ignition process is a key element in the diesel combustion as it influences the combustion process and exhaust emission. Aim of this study is to elucidate the effects of nozzle diameter, injection pressure and ambient temperature to the formation of spray. This study investigated diesel formation spray using Computational Fluid Dynamics. Multiphase volume of fluid (VOF) behaviour in the chamber are determined by means of transient simulation, Eulerian of two phases is used for implementation of mixing fuel and air. The detail behaviour of spray droplet diameter, spray penetration and spray breakup length was visualised using the ANSYS 16.1. This simulation was done in different nozzle diameter 0.12 mm and 0.2 mm performed at the ambient temperature 500 K and 700 K with different injection pressure 40 MPa, 70 MPa and 140 MPa. Results show that high pressure influence droplet diameter become smaller and the penetration length longer with the high injection pressure apply. Smaller nozzle diameter gives a shorter length of the breakup. It is necessary for nozzle diameter and ambient temperature condition to improve the formation of spray. High injection pressure is most effective in improvement of formation spray under higher ambient temperature and smaller nozzle diameter.

Fabrication of ZnO nanorod using spray-pyrolysis and chemical bath deposition method

Energy Technology Data Exchange (ETDEWEB)

Ramadhani, Muhammad F., E-mail: brian@tf.itb.ac.id; Pasaribu, Maruli A. H., E-mail: brian@tf.itb.ac.id; Yuliarto, Brian, E-mail: brian@tf.itb.ac.id; Nugraha, E-mail: brian@tf.itb.ac.id [Advanced Functional Materials Laboratory, Engineering Physics Department Faculty of Industrial Technology, Institut Teknologi Bandung (Indonesia)

2014-02-24

ZnO thin films with nanorod structure were deposited using Ultrasonic Spray Pyrolysis method for seed growth, and Chemical Bath Deposition (CBD) for nanorod growth. High purity Zn-hydrate and Urea are used to control Ph were dissolved in ethanol and aqua bidest in Ultrasonic Spray Pyrolysis process. Glass substrate was placed above the heater plate of reaction chamber, and subsequently sprayed with the range duration of 5, 10 and 20 minutes at the temperatures of 3500 C. As for the Chemical Bath Deposition, the glass substrate with ZnO seed on the surface was immerse to Zn-hydrate, HMTA (Hexa Methylene Tetra Amine) and deionized water solution for duration of 3, 5 and 7 hour and temperatures of 600 C, washed in distilled water, dried, and annealed at 3500 C for an hour. The characterization of samples was carried out to reveal the surface morphology using Scanning Electron Microscopy (SEM). From the data, the combination of 5 minutes of Ultrasonic Spray Pyrolysis process and 3 hour of CBD has showed the best structure of nanorod. Meanwhile the longer Spraying process and CBD yield the bigger nanorod structure that have been made, and it makes the films more dense which make the nanorod collide each other and as a result produce unsymetric nanorod structure.

SPRAY CASTING

OpenAIRE

SALAMCI, Elmas

2010-01-01

ABSTRACT This paper is designed to provide a basic review of spray casting. A brief overview of the historical development of spray  casting and the description of plant and equipment have been given. Following metallurgical characteristics of spray formed alloys, process parameters and solidification mechanism of spray deposition have been discussed in detail. Finally, microstructure and mechanical properties of the selected spray cast Al-Zn-Mg-Cu alloys have been presented and comp...

Evaluation of the Inhibitory Effects of Different Salts on 2,4-D Efficacy in Control of Kochia (Kochiascoparia L. and Redroot pigweed (Amaranthusretroflexus L.

Directory of Open Access Journals (Sweden)

M. Mirzaei

2017-12-01

Full Text Available Introduction: Quality of water used in spray tanks can affect herbicide efficacy, especially acidic herbicides such as 2,4-D. Water is the primary carrier for herbicide applications and it usually makes up over 99% of the spray solution. Considering that, it should be no surprise that the chemistry of water added to the spray tank greatly impacts herbicide effectiveness. Some ions such as calcium and magnesium cations that dissolve into the water, creating various levels of hardness in the water supply. 2,4-D is weak acid herbicide that can be influenced by hard water cations or foliar fertilizers. It has shown reduced activity when applied in water containing calcium and magnesium cations. Hence considering the quality of the water tank sprayer especially hardness helps optimize the efficacy of herbicides. Thus this research was conducted to determine the effect of different salts to 2,4-D on kochia and redroot pigweed as indicator weed species. Material and Methods: Greenhouse experiments were conducted during 2014 at Ferdowsi University of Mashhad to determine the effect of sodium bicarbonate, calcium carbonate, magnesium chloride and calcium chloride in 500 ppm and deionized water as the control on the efficacy of 2,4-D in three doses including 135, 270 and 540 g. a.i. ha-1 (SL 72% with and without ammonium sulfate (AMS ( 2% w/v. Kochia and Redroot pigweed were planted after breaking dormancy in plastic pots. Herbicide was applied using a backpack sprayer calibrated to deliver 290 L ha−1 at 200 kPa with flat-fan nozzles (Tee Jet 8002 flat-fan spray nozzles. Spray solutions were thoroughly agitated each time a new solution was prepared and immediately prior to application to bring herbicide into solution. Living plants were recorded 3 weeks after herbicide treatment irrespective of the timing of application. In addition to survival, the above-ground dry weight of Kochia and redroot pigweed in each pot was determined 3 weeks after the

Improving Tolerance of Faba Bean during Early Growth Stages to Salinity through Micronutrients Foliar Spray

Directory of Open Access Journals (Sweden)

Mohamed M. EL FOULY

2010-06-01

Full Text Available Salinity, either of soil or of irrigation water, causes disturbances in plant growth and nutrient balance. Previous work indicates that applying nutrients by foliar application increases tolerance to salinity. A pot experiment with three replicates was carried out in the green house of NRC, Cairo, Egypt, to study the effect of micronutrients foliar application on salt tolerance of faba bean. Two concentrations of a micronutrient compound (0.1% and 0.15% were sprayed in two different treatments prior to or after the salinity treatments. Levels of NaCl (0.00-1000-2000-5000 ppm were supplied to irrigation water. Results indicated that 2000 and 5000 ppm NaCl inhibited growth and nutrient uptake. Spraying micronutrients could restore the negative effect of salinity on dry weight and nutrients uptake, when sprayed either before or after the salinity treatments. It is suggested that micronutrient foliar sprays could be used to improve plant tolerance to salinity.

Deuterium retention in molten salt electrodeposition tungsten coatings

International Nuclear Information System (INIS)

Zhou, Hai-Shan; Xu, Yu-Ping; Sun, Ning-Bo; Zhang, Ying-Chun; Oya, Yasuhisa; Zhao, Ming-Zhong; Mao, Hong-Min; Ding, Fang; Liu, Feng; Luo, Guang-Nan

2016-01-01

Highlights: • We investigate D retention in electrodeposition W coatings. • W coatings are exposed to D plasmas in the EAST tokamak. • A cathodic current density dependence on D retention is found. • Electrodeposition W exhibits lower D retention than VPS-W. - Abstract: Molten salt electrodeposition is a promising technology to manufacture the first wall of a fusion reactor. Deuterium (D) retention behavior in molten salt electrodeposition tungsten (W) coatings has been investigated by D-plasma exposure in the EAST tokamak and D-ion implantation in an ion beam facility. Tokamak exposure experiments demonstrate that coatings prepared with lower current density exhibit less D retention and milder surface damage. Deuterium-ion implantation experiments indicate the D retention in the molten salt electrodeposition W is less than that in vacuum plasma spraying W and polycrystalline W.

Deuterium retention in molten salt electrodeposition tungsten coatings

Energy Technology Data Exchange (ETDEWEB)

Zhou, Hai-Shan [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Xu, Yu-Ping [Science Island Branch of Graduate School, University of Science and Technology of China, Hefei (China); Sun, Ning-Bo; Zhang, Ying-Chun [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing (China); Oya, Yasuhisa [Radioscience Research Laboratory, Faculty of Science, Shizuoka University, Shizuoka (Japan); Zhao, Ming-Zhong [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Mao, Hong-Min [Science Island Branch of Graduate School, University of Science and Technology of China, Hefei (China); Ding, Fang; Liu, Feng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Luo, Guang-Nan, E-mail: gnluo@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Science Island Branch of Graduate School, University of Science and Technology of China, Hefei (China); Hefei Center for Physical Science and Technology, Hefei (China); Hefei Science Center of Chinese Academy of Science, Hefei (China)

2016-12-15

Highlights: • We investigate D retention in electrodeposition W coatings. • W coatings are exposed to D plasmas in the EAST tokamak. • A cathodic current density dependence on D retention is found. • Electrodeposition W exhibits lower D retention than VPS-W. - Abstract: Molten salt electrodeposition is a promising technology to manufacture the first wall of a fusion reactor. Deuterium (D) retention behavior in molten salt electrodeposition tungsten (W) coatings has been investigated by D-plasma exposure in the EAST tokamak and D-ion implantation in an ion beam facility. Tokamak exposure experiments demonstrate that coatings prepared with lower current density exhibit less D retention and milder surface damage. Deuterium-ion implantation experiments indicate the D retention in the molten salt electrodeposition W is less than that in vacuum plasma spraying W and polycrystalline W.

Bile salt receptor complex activates a pathogenic type III secretion system

Science.gov (United States)

Li, Peng; Rivera-Cancel, Giomar; Kinch, Lisa N; Salomon, Dor; Tomchick, Diana R; Grishin, Nick V; Orth, Kim

2016-01-01

Bile is an important component of the human gastrointestinal tract with an essential role in food absorption and antimicrobial activities. Enteric bacterial pathogens have developed strategies to sense bile as an environmental cue to regulate virulence genes during infection. We discovered that Vibrio parahaemolyticus VtrC, along with VtrA and VtrB, are required for activating the virulence type III secretion system 2 in response to bile salts. The VtrA/VtrC complex activates VtrB in the presence of bile salts. The crystal structure of the periplasmic domains of the VtrA/VtrC heterodimer reveals a β-barrel with a hydrophobic inner chamber. A co-crystal structure of VtrA/VtrC with bile salt, along with biophysical and mutational analysis, demonstrates that the hydrophobic chamber binds bile salts and activates the virulence network. As part of a family of conserved signaling receptors, VtrA/VtrC provides structural and functional insights into the evolutionarily conserved mechanism used by bacteria to sense their environment. DOI: http://dx.doi.org/10.7554/eLife.15718.001 PMID:27377244

Bile salt receptor complex activates a pathogenic type III secretion system

Energy Technology Data Exchange (ETDEWEB)

Li, Peng; Rivera-Cancel, Giomar; Kinch, Lisa N.; Salomon, Dor; Tomchick, Diana R.; Grishin, Nick V.; Orth, Kim

2016-07-05

Bile is an important component of the human gastrointestinal tract with an essential role in food absorption and antimicrobial activities. Enteric bacterial pathogens have developed strategies to sense bile as an environmental cue to regulate virulence genes during infection. We discovered thatVibrio parahaemolyticusVtrC, along with VtrA and VtrB, are required for activating the virulence type III secretion system 2 in response to bile salts. The VtrA/VtrC complex activates VtrB in the presence of bile salts. The crystal structure of the periplasmic domains of the VtrA/VtrC heterodimer reveals a β-barrel with a hydrophobic inner chamber. A co-crystal structure of VtrA/VtrC with bile salt, along with biophysical and mutational analysis, demonstrates that the hydrophobic chamber binds bile salts and activates the virulence network. As part of a family of conserved signaling receptors, VtrA/VtrC provides structural and functional insights into the evolutionarily conserved mechanism used by bacteria to sense their environment.

Evaluation of tecniques for controlling UF6 release clouds in the GAT environmental chamber

International Nuclear Information System (INIS)

Lux, C.J.

1982-01-01

Studies designed to characterize the reaction between UF 6 and atmospheric moisture, evaluate environmental variables of UF 6 cloud formation and ultimate cloud fate, and UF 6 release cloud control procedure have been conducted in the 1200 cu. ft. GAT environmental chamber. In earlier chamber experiments, 30 separate UF 6 release tests indicated that variations of atmospheric conditions and sample sizes had no significant effect on UO 2 F 2 particle size distribution, release cloud formation, or cloud settling rates. During the past year, numerous procedures have been evaluated for accelerating UF 6 cloud knockdown in a series of 37 environmental chamber releases. Knockdown procedures included: coarse water spray; air jet; steam spray (electrostatically charged and uncharged); carbon dioxide; Freon-12; fine water mist (uncharged); boric acid mist (charged and uncharged); and an ionized dry air stream. UF 6 hydrolysis cloud settling rates monitored by a laser/powermeter densitometer, indicated the relative effectiveness of various cloud knockdown techniques. Electrostatically charged boric acid/water mist, and electrostatically ionized dry air were both found to be very effective, knocking down the UO 2 F 2 release cloud particles in two to five minutes. Work to adapt these knockdown techniques for use under field conditions is continuing, taking into account recovery of the released uranium as well as nuclear criticality constraints

Flow Characteristics of Multi-circular Jet Plate in Premix Chamber of Air-Assist Atomizer for Burner System

Directory of Open Access Journals (Sweden)

Amirnordin Shahrin Hisham

2016-01-01

Full Text Available The flow characteristics of multi-circular jet (MCJ plate in the premix chamber of an atomizer were investigated using Computational Fluid Dynamics. Multiphase volume of fluid behavior inside the chamber was determined via steady simulations. The Eulerian–Eulerian two-fluid approach was used for execution mixing of diesel fuel and air. Spray simulation using the discrete phase with injection was generated from the nozzle hole into the ambient atmosphere. The behavior of three MCJ plates in the premix chamber was studied numerically. Results illustrated that plate open area, Ae, influenced the turbulence inside the chamber. MCJ 3, which had the lowest open area, generated the highest flow velocity and turbulence kinetic energy compared with MCJ 1 and 2. The MCJ plates could increase the turbulence in the premix chamber and contribute to the combustion efficiency.

Visualization research on spray atomization, evaporation and combustion processes of ethanol–diesel blend under LTC conditions

International Nuclear Information System (INIS)

Huang, Sheng; Deng, Peng; Huang, Ronghua; Wang, Zhaowen; Ma, Yinjie; Dai, Hui

2015-01-01

Highlights: • Spray combustion of E20 diesel in LTC condition shows a U-shape flame structure. • The chasing behavior of fuel spray exists near the spray axis. • Fuel ignition doesn’t initiate at the spray tip but in peripheral regions behind it. • An improper chamber structure may lead to a long post-combustion duration. - Abstract: Utilization of ethanol in diesel engines has been widely studied by means of engine experiments and emission detection. However, pertinent studies on the spray combustion process of ethanol–diesel blends are scarce. In order to verify the effect of ethanol in modern diesel engines, an experiment is conducted to visualize the spray combustion process of ethanol–diesel blend under LTC conditions. Stages including atomization, evaporation and combustion, are investigated individually to realize synergistic analysis. Meanwhile, considering the long time scale of combustion after fuel injection finishes, characteristics during and after injection period are both targeted in this paper. Moreover, measurement of macroscopic characteristics, such as spray tip penetration, spray spreading cone angle and flame lift off length, provides a quantitative profile of the spray structure. Results show that, evaporation, different from atomization, has little influence on spray penetration, but promotes the spray spreading angle and spray projected area. So does combustion, which enlarges the spray projected area further. Ignition takes place on the periphery behind the spray tip, then quickly extends to the whole head of the spray and forms a U-shape diffusion structure. After the injection period, the residual spray tail develops into wavelike structures due to absence of subsequent entrainment force. Also, the penetration speed falls greatly to an extent much slower than flame propagation, which frees the flame from the lift-off effect. Subsequently, the flame propagates upstream towards the nozzle orifice. After consumed all fuel in

Spray-coated Cu2ZnSnS4 thin films for large-scale photovoltaic applications

DEFF Research Database (Denmark)

Engberg, Sara Lena Josefin; Murthy, Swathi; Mariño, Simón López

2017-01-01

The kesterite material, Cu2ZnSnS4 (CZTS), has in the preceding ten years been investigated and developed as a new Earth-abundant material for solar cells. The interest in this inorganic semiconductor originates in its optimal energy band gap of approx. 1.5 eV, high absorption coefficient...... that alkali metal chloride salts can also be dissolved in controllable amounts, which we have found enhances grain growth in the films during the subsequent annealing step. A Sono-tek spray-coating system with ultrasonic atomization is used. We investigate the effect of ink concentration, and spray...

Particulate pollutants are capable to 'degrade' epicuticular waxes and to decrease the drought tolerance of Scots pine (Pinus sylvestris L.).

Science.gov (United States)

Burkhardt, Juergen; Pariyar, Shyam

2014-01-01

Air pollution causes the amorphous appearance of epicuticular waxes in conifers, usually called wax 'degradation' or 'erosion', which is often correlated with tree damage symptoms, e.g., winter desiccation. Previous investigations concentrated on wax chemistry, with little success. Here, we address the hypothesis that both 'wax degradation' and decreasing drought tolerance of trees may result from physical factors following the deposition of salt particles onto the needles. Pine seedlings were sprayed with dry aerosols or 50 mM solutions of different salts. The needles underwent humidity changes within an environmental scanning electron microscope, causing salt expansion on the surface and into the epistomatal chambers. The development of amorphous wax appearance by deliquescent salts covering tubular wax fibrils was demonstrated. The minimum epidermal conductance of the sprayed pine seedlings increased. Aerosol deposition potentially 'degrades' waxes and decreases tree drought tolerance. These effects have not been adequately considered thus far in air pollution research. Copyright © 2013 Elsevier Ltd. All rights reserved.

Studies on Microscopic Structure of Diesel Sprays under Atmospheric and High Gas Pressures

Directory of Open Access Journals (Sweden)

D. Deshmukh

2014-06-01

Full Text Available In the present work, the spray structure of diesel from a 200-μm, single-hole solenoid injector is studied using microscopic imaging at injection pressures of 700, 1000 and 1400 bar for various gas pressures. A long-distance microscope with a high resolution camera is used for spray visualization with a direct imaging technique. This study shows that even at very high injection pressures, the spray structure in an ambient environment of atmospheric pressure reveals presence of entangled ligaments and non-spherical droplets during the injection period. With increase in the injection pressure, the ligaments tend to get smaller and spread radially. The spray structure studies are also conducted at high gas pressures in a specially designed high pressure chamber with optical access. The near nozzle spray structure at the end of the injection shows that the liquid jet breakup is improved with increase in gas density. The droplet size measurement is possible only late in the injection duration when the breakup appears to be complete and mostly spherical droplets are observed. Hence, droplet size measurements are performed after 1.3 ms from start of the injection pulse. Spatial and temporal variation in Sauter Mean Diameter (SMD is observed and reported for the case corresponding to an injection pressure of 700 bar. Overall, this study has highlighted the importance of verifying the extentof atomization and droplet shape even in dense sprays before using conventional dropsizing methods such as PDPA.

Therapeutic paint of cidofovir/sucralfate gel combination topically administered by spraying for treatment of orf virus infections.

Science.gov (United States)

Sonvico, Fabio; Colombo, Gaia; Gallina, Laura; Bortolotti, Fabrizio; Rossi, Alessandra; McInnes, Colin J; Massimo, Gina; Colombo, Paolo; Scagliarini, Alessandra

2009-06-01

The aim of the research was to study a new cidofovir/sucralfate drug product to be used as a spray for treating the mucosal and/or skin lesions. The product, i.e., a water suspension of sucralfate (15% w/w) and cidofovir (1% w/w), combines the potent antiviral activity of the acyclic nucleoside phosphonate cidofovir ((S)-1-[3-hydroxy-2-(phosphonomethoxy)propyl]cytosine) and the wound healing properties of sucralfate gel (sucrose octasulphate basic aluminum salt). The product was characterized in vitro with respect to compatibility between drug and carrier, spray particle size, spray deposition, drying kinetics, and drug content and release. An interaction between the two active substances was found. The interaction between sucralfate and cidofovir was counteracted by introducing sodium dihydrogen phosphate (16% w/w) in the preparation. The spray formulation containing cidofovir/sucralfate gel painted the skin and dried quickly to a scab, remaining firmly adhered to the lesions. The therapeutic paint was tested in vivo on lambs infected with orf virus by treating the animals with different cidofovir/sucralfate formulations (0.5% or 1% cidofovir + sucralfate 15% + NaH(2)PO(4) 16% w/w) and with sucralfate gel suspension alone as control. The treatment with formulations containing cidofovir and phosphate salt for four consecutive days resulted in a rapid resolution of the lesions, with scabs containing significantly lower amounts of viable virus when compared with untreated lesions and lesions treated with sucralfate suspension alone.

High temperature corrosion of thermally sprayed NiCr- and amorphous Fe-based coatings covered with a KCl-K{sub 2}SO{sub 4} salt

Energy Technology Data Exchange (ETDEWEB)

Varis, T.; Suhonen, T.; Tuurna, S.; Ruusuvuori, K.; Holmstroem, S.; Salonen, J. [VTT, Espoo (Finland); Bankiewicz, D.; Yrjas, P. [Aabo Akademi Univ., Turku (Finland)

2010-07-01

New process conditions due to the requirement of higher efficiency together with the use of high-chlorine and alkali containing fuels such as biomass and waste fuels for heat and electricity production will challenge the resistance and life of tube materials. In conventional materials the addition of alloying elements to increase the corrosion resistance in aggressive combustion conditions increases costs relatively rapidly. Thermally sprayed coating offer promising, effective, flexible and cost efficient solutions to fulfill the material needs for the future. Some heat exchanger design alteractions before global commercialization have to be overcome, though. High temperature corrosion in combustion plants can occur by a variety of mechanisms including passive scale degradation with subsequent rapid scaling, loss of adhesion and scale detachment, attack by melted or partly melted deposits via fluxing reactions and intergranular-/interlamellar corrosion. A generally accepted model of the ''active oxidation'' attributes the responsibility for inducing corrosion to chlorine. The active oxidation mechanism plays a key role in the thermally sprayed coatings due to their unique lamellar structure. In this study, the corrosion behaviour of NiCr (HVOF and Wire Arc), amorphous Fe-based, and Fe13Cr (Wire Arc) thermally sprayed coatings, were tested in the laboratory under simplified biomass combustion conditions. The tests were carried out by using a KCl-K{sub 2}SO{sub 4} salt mixture as a synthetic biomass ash, which was placed on the materials and then heat treated for one week (168h) at two different temperatures (550{sup 0}C and 600 C) and in two different gas atmospheres (air and air+30%H{sub 2}O). After the exposures, the metallographic cross sections of the coatings were studied with SEM/EDX analyzer. The results showed that the coatings behaved relatively well at the lower test temperature while critical corrosion through the lamella boundaries

Improvement of the inlet system for the spray-jet technique for use in spectroscopic studies and molecular deposition

International Nuclear Information System (INIS)

Yamada, Toshiki; Shinohara, Hidenori; Mashiko, Shinro

2006-01-01

We previously developed a molecular beam apparatus with a spray-jet technique in order to produce a molecular beam of non-volatile molecules in vacuum from the sprayed mist of a sample solution. The apparatus is for use in spectroscopic studies or a means of molecular deposition. The spray-jet inlet system consisted of an ultrasonic nebulizer, an inlet chamber and a pulsed nozzle. In the present paper, further improvements to the spray-jet inlet system are reported. The main improvement is the introduction of a pneumatic nebulizer to replace the previous ultrasonic nebulizer. The efficiency of molecular beam generation was evaluated on the basis of the signal intensity of the resonantly enhanced multiphoton ionization time-of-flight mass (REMPI-TOFMS) spectra for a Rhodamine B/methanol solution and the amount of sample consumed. The introduction of the pneumatic nebulizer increased the efficiency by a factor of 20

The decay of a lambda particle in the 32 cm hydrogen bubble chamber

CERN Multimedia

1960-01-01

This image from 1960 is of real particle tracks formed in CERN's first liquid hydrogen bubble chamber to be used in experiments. It was a tiny detector by today's standards at only 32 cm in diameter. Negatively charged pions with an energy of 16 GeV enter from the left. One of them interacts with a proton in the liquid hydrogen and creates sprays of new particles, including a neutral particle (a lambda) that decays to produce the "V" of two charged particle tracks at the centre. Lower-energy charged particles produced in the interactions spiral in the magnetic field of the chamber. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real particle tracks to be seen and photographed, after releasing the pressure that had kept a liquid above its normal boiling point.

Spray and Combustion Characteristics of a Novel Multi-circular Jet Plate in Air-assisted Atomizer

Directory of Open Access Journals (Sweden)

Hisham Amirnordin Shahrin

2017-01-01

Full Text Available Atomization of liquid fuel in air-assisted atomizer is highly dependent on air mixing, which can be enhanced using turbulent generators, such as multi-circular jet (MCJ plates and swirler. This study aims to determine the effects of novel MCJ plates on the spray and combustion characteristics of an air-assisted atomizer by evaluating spray and flame parameters, such as penetration length, cone angle, and cone area. MCJ 30 and MCJ 45, with inclined jets at 30° and 45°, respectively, were used in the experiment. A swirler was also used for comparison. The spray and flame images were recorded at different equivalence ratios through direct photography and analyzed using image J software. Flame temperature was determined using a thermal infrared camera, and burning chamber and flue gas temperatures were measured using thermocouples. The spray and flame characteristics of MCJ 30 exhibited performance comparable with those of the MCJ 45 and swirler. The integration of turbulence and swirling motion concept into the novel MCJ plates can enhance the mixing formation and thus improve the performance of burner combustion.

Structure and Corrosion Resistance of Welded Joints of Alloy 1151 in Marine Atmosphere

Science.gov (United States)

Bakulo, A. V.; Yakushin, B. F.; Puchkov, Yu. A.

2017-07-01

The corrosion behavior of joints formed by TIG and IMIG welding from clad sheets of heat-hardenable aluminum alloy 1151 of the Al - Cu - Mg system is studied. The corrosion tests are performed in an aqueous solution of NaCl in a salt-spray chamber. The welded joints are subjected to a metallographic analysis.

Advanced Research in Diesel Fuel Sprays Using X-rays From The Advanced Photon Source

International Nuclear Information System (INIS)

Powell, C.

2003-01-01

The fuel distribution and degree of atomization in the combustion chamber is a primary factor in the formation of emissions in diesel engines. A number of diagnostics to study sprays have been developed over the last twenty years; these are primarily based on visible light measurement techniques. However, visible light scatters strongly from fuel droplets surrounding the spray, which prevents penetration of the light. This has made quantitative measurements of the spray core very difficult, particularly in the relatively dense near- nozzle region [1-3]. For this reason we developed the x-ray technique to study the properties of fuel sprays in a quantitative way [4]. The x-ray technique is not limited by scattering, which allows it to be used to make quantitative measurements of the fuel distribution. These measurements are particularly effective in the region near the nozzle where other techniques fail. This technique has led to a number of new insights into the structure of fuel sprays, including the discovery and quantitative measurement of shock waves generated under some conditions by high-pressure diesel sprays [5]. We also performed the first-ever quantitative measurements of the time-resolved mass distribution in the near-nozzle region, which demonstrated that the spray is atomized only a few nozzle diameters from the orifice [6]. Our recent work has focused on efforts to make measurements under pressurized ambient conditions. We have recently completed a series of measurements at pressures up to 5 bar and are looking at the effect of ambient pressure on the structure of the spray. The enclosed figure shows the mass distributions measured for 1,2, and 5 bar ambient pressures. As expected, the penetration decreases as the pressure increases. This leads to changes in the measured mass distribution, including an increase in the density at the leading edge of the spray. We have also observed a narrowing in the cone angle of the spray core as the pressure

Studies on Nanocrystalline TiN Coatings Prepared by Reactive Plasma Spraying

Directory of Open Access Journals (Sweden)

Dong Yanchun

2008-01-01

Full Text Available Titanium nitride (TiN coatings with nanostructure were prepared on the surface of 45 steel (Fe-0.45%C via reactive plasma spraying (denoted as RPS Ti powders using spraying gun with self-made reactive chamber. The microstructural characterization, phases constitute, grain size, microhardness, and wear resistance of TiN coatings were systematically investigated. The grain size was obtained through calculation using the Scherrer formula and observed by TEM. The results of X-ray diffraction and electron diffraction indicated that the TiN is main phase of the TiN coating. The forming mechanism of the nano-TiN was characterized by analyzing the SEM morphologies of surface of TiN coating and TiN drops sprayed on the surface of glass, and observing the temperature and velocity of plasma jet using Spray Watch. The tribological properties of the coating under nonlubricated condition were tested and compared with those of the AISI M2 high-speed steel and Al2O3 coating. The results have shown that the RPS TiN coating presents better wear resistance than the M2 high-speed steel and Al2O3 coating under nonlubricated condition. The microhardness of the cross-section and longitudinal section of the TiN coating was tested. The highest hardness of the cross-section of TiN coating is 1735.43HV100 g.

Comparison of three control strategies for optimization of spray dryer operation

DEFF Research Database (Denmark)

Petersen, Lars Norbert; Poulsen, Niels Kjølstad; Niemann, Hans Henrik

2017-01-01

controllers for operation of a four-stage spray dryer. The three controllers are a proportional-integral (PI) controller that is used in industrial practice for spray dryer operation, a linear model predictive controller with real-time optimization (MPC with RTO, MPC-RTO), and an economically optimizing...... nonlinear model predictive controller (E-NMPC). The MPC with RTO is based on the same linear state space model in the MPC and the RTO layer. The E-NMPC consists of a single optimization layer that uses a nonlinear system of ordinary differential equations for its predictions. The PI control strategy has...... the production rate, while minimizing the energy consumption, keeping the residual moisture content of the powder below a maximum limit, and avoiding that the powder sticks to the chamber walls. We use an industrially recorded disturbance scenario in order to produce realistic simulations and conclusions...

In situ analysis of corrosion inhibitors using a portable mass spectrometer with paper spray ionization.

Science.gov (United States)

Jjunju, Fred P M; Li, Anyin; Badu-Tawiah, Abraham; Wei, Pu; Li, Linfan; Ouyang, Zheng; Roqan, Iman S; Cooks, R Graham

2013-07-07

Paper spray (PS) ambient ionization is implemented using a portable mass spectrometer and applied to the detection of alkyl quaternary ammonium salts in a complex oil matrix. These salts are commonly used as active components in the formulation of corrosion inhibitors. They were identified in oil and confirmed by their fragmentation patterns recorded using tandem mass spectrometry (MS/MS). The cations of alkyl and benzyl-substituted quaternary ammonium salts showed characteristic neutral losses of CnH2n (n carbon number of the longest chain) and C7H8, respectively. Individual quaternary ammonium compounds were detected at low concentrations (oil samples without prior sample preparation or pre-concentration was also demonstrated using a home-built miniature mass spectrometer at levels below 1 ng μL(-1).

High quality ceramic coatings sprayed by high efficiency hypersonic plasma spraying gun

International Nuclear Information System (INIS)

Zhu Sheng; Xu Binshi; Yao JiuKun

2005-01-01

This paper introduced the structure of the high efficiency hypersonic plasma spraying gun and the effects of hypersonic plasma jet on the sprayed particles. The optimised spraying process parameters for several ceramic powders such as Al 2 O 3 , Cr 2 O 3 , ZrO 2 , Cr 3 C 2 and Co-WC were listed. The properties and microstructure of the sprayed ceramic coatings were investigated. Nano Al 2 O 3 -TiO 2 ceramic coating sprayed by using the high efficiency hypersonic plasma spraying was also studied. Compared with the conventional air plasma spraying, high efficiency hypersonic plasma spraying improves greatly the ceramic coatings quality but at low cost. (orig.)

Yb2Si2O7 Environmental Barrier Coatings Deposited by Various Thermal Spray Techniques: A Preliminary Comparative Study

Science.gov (United States)

Bakan, Emine; Marcano, Diana; Zhou, Dapeng; Sohn, Yoo Jung; Mauer, Georg; Vaßen, Robert

2017-08-01

Dense, crack-free, uniform, and well-adhered environmental barrier coatings (EBCs) are required to enhance the environmental durability of silicon (Si)-based ceramic matrix composites in high pressure, high gas velocity combustion atmospheres. This paper represents an assessment of different thermal spray techniques for the deposition of Yb2Si2O7 EBCs. The Yb2Si2O7 coatings were deposited by means of atmospheric plasma spraying (APS), high-velocity oxygen fuel spraying (HVOF), suspension plasma spraying (SPS), and very low-pressure plasma spraying (VLPPS) techniques. The initial feedstock, as well as the deposited coatings, were characterized and compared in terms of their phase composition. The as-sprayed amorphous content, microstructure, and porosity of the coatings were further analyzed. Based on this preliminary investigation, the HVOF process stood out from the other techniques as it enabled the production of vertical crack-free coatings with higher crystallinity in comparison with the APS and SPS techniques in atmospheric conditions. Nevertheless, VLPPS was found to be the preferred process for the deposition of Yb2Si2O7 coatings with desired characteristics in a controlled-atmosphere chamber.

Soot temperature and KL factor for biodiesel and diesel spray combustion in a constant volume combustion chamber

KAUST Repository

Zhang, Ji

2013-07-01

This paper presents measurements of the soot temperature and KL factor for biodiesel and diesel combustion in a constant volume chamber using a two-color technique. This technique uses a high-speed camera coupled with two narrowband filters (550. nm and 650. nm, 10. nm FWHM). After calibration, statistical analysis shows that the uncertainty of the two-color temperature is less than 5%, while it is about 50% for the KL factor. This technique is then applied to the spray combustion of biodiesel and diesel fuels under an ambient oxygen concentration of 21% and ambient temperatures of 800, 1000 and 1200. K. The heat release result shows higher energy utilization efficiency for biodiesel compared to diesel under all conditions; meanwhile, diesel shows a higher pressure increase due to its higher heating value. Biodiesel yields a lower temperature inside the flame area, a longer soot lift-off length, and a smaller soot area compared to diesel. Both the KL factor and the total soot with biodiesel are lower than with diesel throughout the entire combustion process, and this difference becomes larger as the ambient temperature decreases. Biodiesel shows approximately 50-100. K lower temperatures than diesel at the quasi-steady stage for 1000 and 1200. K ambient temperature, while diesel shows a lower temperature than biodiesel at 800. K ambient. This result may raise the question of how important the flame temperature is in explaining the higher NO. x emissions often observed during biodiesel combustion. Other factors may also play an important role in controlling NO. x emissions. Both biodiesel and diesel temperature measurements show a monotonic dependence on the ambient temperature. However, the ambient temperature appears to have a more significant effect on the soot formation and oxidation in diesel combustion, while biodiesel combustion soot characteristics shows relative insensitivity to the ambient temperature. © 2013 Elsevier Ltd.

Burner rig alkali salt corrosion of several high temperature alloys

Science.gov (United States)

Deadmore, D. L.; Lowell, C. E.

1977-01-01

The hot corrosion of five alloys was studied in cyclic tests in a Mach 0.3 burner rig into whose combustion chamber various aqueous salt solutions were injected. Three nickel-based alloys, a cobalt-base alloy, and an iron-base alloy were studied at temperatures of 700, 800, 900, and 1000 C with various salt concentrations and compositions. The relative resistance of the alloys to hot corrosion attack was found to vary with temperature and both concentration and composition of the injected salt solution. Results indicate that the corrosion of these alloys is a function of both the presence of salt condensed as a liquid on the surface and of the composition of the gas phases present.

Device for automatically operating cooling mode of water in a pressure suppression chamber

International Nuclear Information System (INIS)

Sato, Hideyuki.

1975-01-01

Object: To provide a system for removing residual heat in a reactor safety system, which can automatically cool water in a pressure suppression chamber when a load on a generator is cut off, so as not to scram the reactor. Structure: When a load cut-off signal is generated by means of rapid closure of a turbine regulating valve or due to the load unbalance relay of generator output, or the like, a sea water pump is started to fully open an outlet valve for the sea water pump, a heat exchanging inlet valve and a minimum crow valve and to fully close a heat exchanging bypass valve. In this manner, cooling water for the heat exchanger is secured to start the pump in the system for removing residual heat, and when the pump discharge pressure is in normal condition, the inlet valve in pressure suppression chamber and the spray valve in the pressure suppression chamber are fully opened to automatically cool water in the pressure suppression chamber. (Hanada, M.)

Effect of spray angle and spray volume on deposition of a medium droplet spray with air support in ivy pot plants.

Science.gov (United States)

Foqué, Dieter; Pieters, Jan G; Nuyttens, David

2014-03-01

Spray boom systems, an alternative to the predominantly-used spray guns, have the potential to considerably improve crop protection management in glasshouses. Based on earlier experiments, the further optimization of the deposits of a medium spray quality extended range flat fan nozzle type using easy adjustable spray boom settings was examined. Using mineral chelate tracers and water sensitive papers, the spray results were monitored at three plant levels, on the upper side and the underside of the leaves, and on some off-target collectors. In addition, the deposition datasets of all tree experiments were compared. The data showed that the most efficient spray distribution with the medium spray quality flat fan nozzles was found with a 30° forward angled spray combined with air support and an application rate of 1000 L ha(-1) . This technique resulted in a more uniform deposition in the dense canopy and increased spray deposition on the lower side of the leaves compared with the a standard spray boom application. Applying 1000 L ha(-1) in two subsequent runs instead of one did not seem to show any added value. Spray deposition can be improved hugely simply by changing some spray boom settings like nozzle type, angling the spray, using air support and adjusting the spray volume to the crop. © 2013 Society of Chemical Industry.

Optical fuel spray measurements

Energy Technology Data Exchange (ETDEWEB)

Hillamo, H.

2011-07-01

Diesel fuel sprays, including fuel/air mixing and the physics of two-phase jet formation, are discussed in the thesis. The fuel/air mixing strongly affects emissions formation in spray combustion processes where the local combustion conditions dictate the emission formation. This study comprises optical measurements both in pressurized spray test rigs and in a running engine.The studied fuel injection was arranged with a common rail injection system and the injectors were operated with a solenoid-based injection valve. Both marine and heavy-duty diesel engine injectors were used in the study. Optical fuel spray measurements were carried out with a laser-based double-framing camera system. This kind of equipments is usually used for flow field measurements with Particle Image Velocimetry technique (PIV) as well as for backlight imaging. Fundamental fuel spray properties and spray formation were studied in spray test rigs. These measurements involved studies of mixing, atomization, and the flow field. Test rig measurements were used to study the effect of individual injection parameters and component designs. Measurements of the fuel spray flow field, spray penetration, spray tip velocity, spray angle, spray structure, droplet accumulation, and droplet size estimates are shown. Measurement campaign in a running optically accessible large-bore medium-speed engine was also carried out. The results from engine tests were compared with equivalent test rig measurements, as well as computational results, to evaluate the level of understanding of sprays. It was shown that transient spray has an acceleration and a deceleration phase. Successive flow field measurements (PIV) in optically dense diesel spray resulted in local and average velocity data of diesel sprays. Processing fuel spray generates a flow field to surrounding gas and entrainment of surrounding gas into fuel jet was also seen at the sides of the spray. Laser sheet imaging revealed the inner structure of diesel

Spray characteristics and spray cooling heat transfer in the non-boiling regime

International Nuclear Information System (INIS)

Cheng, Wen-Long; Han, Feng-Yun; Liu, Qi-Nie; Fan, Han-Lin

2011-01-01

Spray cooling is an effective method for dissipating high heat fluxes in the field of electronics thermal control. In this study, experiments were performed with distilled water as a test liquid to study the spray cooling heat transfer in non-boiling regime. A Phase Doppler Anemometry (PDA) was used to study the spray characteristics. The effects of spray flow rate, spray height, and inlet temperature on spray cooling heat transfer were investigated. It was found that the parameters affect heat transfer of spray cooling in non-boiling regime by the spray characteristics and working fluid thermophysical properties. Then the corresponding droplet axial velocity and Sauter mean diameter (SMD) were successfully correlated with mean absolute error of 15%, which were based upon the orifice diameter, the Weber and Reynolds numbers of the orifice flow prior to liquid breakup, dimensionless spray height and spray cross-section radius. The heat transfer in non-boiling regime was correlated with a mean absolute error of 7%, which was mainly associated with the working fluid thermophysical properties, the Weber and Reynolds numbers hitting the heating surface, dimensionless heating surface temperature and diameter. -- Highlights: → The spray flow rate, spray height, and inlet temperature affect heat transfer of spray cooling in non-boiling regime by the spray characteristics and the working fluid thermophysical properties. → Then the corresponding droplet axial velocity and Sauer mean diameter (SMD) were successfully correlated with mean absolute error of 15%. → The heat transfer in non-boiling regime was correlated with a mean absolute error of 7%.

Layered growth with bottom-spray granulation for spray deposition of drug.

Science.gov (United States)

Er, Dawn Z L; Liew, Celine V; Heng, Paul W S

2009-07-30

The gap in scientific knowledge on bottom-spray fluidized bed granulation has emphasized the need for more studies in this area. This paper comparatively studied the applicability of a modified bottom-spray process and the conventional top-spray process for the spray deposition of a micronized drug during granulation. The differences in circulation pattern, mode of growth and resultant granule properties between the two processes were highlighted. The more ordered and consistent circulation pattern of particles in a bottom-spray fluidized bed was observed to give rise to layered granule growth. This resulted in better drug content uniformity among the granule batches and within a granule batch. The processes' sensitivities to wetting and feed material characteristics were also compared and found to differ markedly. Less robustness to differing process conditions was observed for the top-spray process. The resultant bottom-spray granules formed were observed to be less porous, more spherical and had good flow properties. The bottom-spray technique can thus be potentially applied for the spray deposition of drug during granulation and was observed to be a good alternative to the conventional technique for preparing granules.

Effect of nebulizer/spray chamber interfaces on simultaneous, axial view inductively coupled plasma optical emission spectrometry for the direct determination of As and Se species separated by ion exchange high-performance liquid chromatography

International Nuclear Information System (INIS)

Gettar, Raquel T.; Smichowski, Patricia; Garavaglia, Ricardo N.; Farias, Silvia; Batistoni, Daniel A.

2005-01-01

Different nebulizer/expansion chamber combinations were evaluated to assess their performance for sample introduction in the direct coupling with an axial view inductively coupled plasma multielement spectrometer for on-line determination of As and Se species previously separated by ion exchange-high performance liquid chromatography. The column effluents were injected into the plasma without prior derivatization. The instrument operation software was adapted for data acquisition and processing to allow multi-wavelength recording of the transient chromatographic peaks. After optimization of the chromatographic operating conditions, separation of mixtures of inorganic As and Se species, and of inorganic and two organic As species (monomethylarsonic and dimethylarsinic acids), was achieved with excellent resolution. Species discrimination from mixtures of As and Se oxyanions was further improved by the simultaneous element detection at specific analytical wavelengths. Three nebulizers and three spray chambers, employed in seven combinations, were tested as interfaces. Concentric nebulizers associated to a glass cyclonic chamber appear most suitable regarding sensitivity and signal to noise ratio. Measured element detection limits (3 σ) were around 10 ng ml -1 for all the species considered, making the method a viable alternative to similar procedures that employ volatile hydride generation previous to sample injection into the plasma. Analytical recoveries both for inorganic and organic species ranged between 92 and 107%. The method was demonstrated to be apt for the analysis of surface waters potentially subjected to natural contamination with arsenic

Spray deposition and spray drift in orchard spraying by multiple row sprayers

NARCIS (Netherlands)

Wenneker, M.; Zande, van de J.C.; Michielsen, J.G.P.; Stallinga, H.; Velde, van P.

2016-01-01

The evaluation of the latest data on spray drift in orchard spraying in the Netherlands, and measurements of surface water quality parameters show that the current legislation and measures are insufficient to protect the surface water. To meet the national and European objectives regarding surface

Survival of Four Probiotic Strains in Acid, Bile Salt and After Spray Drying

OpenAIRE

Rawichar Chaipojjana; Suttipong Phosuksirikul; Arunsri Leejeerajumnean

2014-01-01

The objective of the study was to select the survival of probiotic strains when exposed to acidic and bile salts condition. Four probiotic strains Lactobacillus casei subsp. rhamnosus TISTR 047, Lactobacillus casei TISTR 1500, Lactobacillus acidophilus TISTR 1338 and Lactobacillus plantarum TISTR 1465 were cultured in MRS broth and incubated at 35ºC for 15 hours before being inoculated into acidic condition 5 M HCl, pH 2 for 2 hours and bile salt 0.3%, pH 5.8 for 8 hour. ...

Method and Apparatus for Thermal Spraying of Metal Coatings Using Pulsejet Resonant Pulsed Combustion

Science.gov (United States)

Paxson, Daniel E. (Inventor)

2014-01-01

An apparatus and method for thermal spraying a metal coating on a substrate is accomplished with a modified pulsejet and optionally an ejector to assist in preventing oxidation. Metal such as Aluminum or Magnesium may be used. A pulsejet is first initiated by applying fuel, air, and a spark. Metal is inserted continuously in a high volume of metal into a combustion chamber of the pulsejet. The combustion is thereafter controlled resonantly at high frequency and the metal is heated to a molten state. The metal is then transported from the combustion chamber into a tailpipe of said pulsejet and is expelled therefrom at high velocity and deposited on a target substrate.

Effect of spray application technique on spray deposition in greenhouse strawberries and tomatoes.

Science.gov (United States)

Braekman, Pascal; Foque, Dieter; Messens, Winy; Van Labeke, Marie-Christine; Pieters, Jan G; Nuyttens, David

2010-02-01

Increasingly, Flemish greenhouse growers are using spray booms instead of spray guns to apply plant protection products. Although the advantages of spray booms are well known, growers still have many questions concerning nozzle choice and settings. Spray deposition using a vertical spray boom in tomatoes and strawberries was compared with reference spray equipment. Five different settings of nozzle type, size and pressure were tested with the spray boom. In general, the standard vertical spray boom performed better than the reference spray equipment in strawberries (spray gun) and in tomatoes (air-assisted sprayer). Nozzle type and settings significantly affected spray deposition and crop penetration. Highest overall deposits in strawberries were achieved using air-inclusion or extended-range nozzles. In tomatoes, the extended-range nozzles and the twin air-inclusion nozzles performed best. Using smaller-size extended-range nozzles above the recommended pressure range resulted in lower deposits, especially inside the crop canopy. The use of a vertical spray boom is a promising technique for applying plant protection products in a safe and efficient way in tomatoes and strawberries, and nozzle choice and setting should be carefully considered.

Influence of fuel properties on fundamental spray characteristics and soot emissions using different tailor-made fuels from biomass

International Nuclear Information System (INIS)

García, Antonio; Monsalve-Serrano, Javier; Heuser, Benedikt; Jakob, Markus; Kremer, Florian; Pischinger, Stefan

2016-01-01

Highlights: • TMFB show clear potential to reduce soot emissions under mixing-controlled combustion. • The larger lift-off-length of 2-MTHF and 1-octanol promotes soot emissions reduction. • Oxidation process governs the improved soot emissions of DNBE. - Abstract: This work evaluates the potential of some new biomass-derived fuels as candidates for compression ignition operation. Thus, fundamental spray characteristics related to fuel vaporization and fuel/air mixing process for 2-Methyltetrahydrofuran, Di-n-butyl ether and 1-octanol has been studied and compared with conventional EN590 Diesel fuel. For this purpose, OH"∗ chemiluminescence and shadowgraphy measurements in a high pressure chamber as well as 1D simulations with a spray model have been carried out at different operating conditions representative of the NEDC driving cycle. Finally, measured soot emissions in the single-cylinder engine were presented and discussed. Results from the high pressure chamber presented very good agreement in terms of liquid length and vapor penetration with simulation results. Thus, some analytical expressions related to macroscopic spray characteristics have been proposed and validated experimentally for all four fuels. Finally, the single-cylinder engine results confirmed the relevant role of soot formation on final emissions for 1-octanol and 2-MTHF. In addition, DNBE showed greater soot oxidation potential than diesel and other TMFB candidates.

Indoor spray measurement of spray drift potential using a spray drift test bench : effect of drift-reducing nozzle types, spray boom height, nozzle spacing and forward speed

NARCIS (Netherlands)

Moreno Ruiz, J.R.

2014-01-01

In a series of indoor experiments spray drift potential was assessed when spraying over a spray drift testbench with two different driving speeds, 2m/s and 4m/s, two different spray boom heights, 30 cm and 50 cm, and two different nozzle spacing, 25 cm and 50 cm, for six different nozzle types. The

Corrosion resistance and characterization of metallic coatings deposited by thermal spray on carbon steel

International Nuclear Information System (INIS)

Sá Brito, V.R.S.; Bastos, I.N.; Costa, H.R.M.

2012-01-01

Highlights: ► Five combinations of metallic coatings and intermediate bonds were deposited on carbon steels. ► High strength was reached in adhesion tests. ► Epoxy sealing of coatings improves corrosion resistance. -- Abstract: Carbon steels are not resistant to corrosion and several methods are used in surface engineering to protect them from aggressive environments such as marine. The main objective of this work is the evaluation of mechanical and metallurgical properties of five metallic coatings produced by thermal spray on carbon steel. Five chemical compositions were tested in order to give a large panel of possibility. Coatings were characterized by several methods to result in a screening of their performance. At first, the assessment of microstructural morphology by optical microscopy (OM) and by scanning electron microscopy (SEM) was made. OM and SEM results showed uniformity of deposited layer, low amount of oxides and porosity. The physical properties of coatings were also evaluated by microhardness measurement, adhesion and porosity quantification. The corrosion resistance was analyzed in salt spray and electrochemical polarization tests. In the polarization test, as well as in the salt spray, all sealed conditions presented low corrosion. A new intermediate 78.3Ni20Cr1.4Si0.3Fe alloy was studied in order to reduce pores and microcracks that are frequently found in ordinary 95Ni5Al alloy. Based on the performed characterizations, the findings suggested that the FeCrCo deposition, with an epoxy sealing, is suitable to be used as an efficient coating of carbon steel in aggressive marine environments.

The Effect of Nozzle Design and Operating Conditions on the Atomization and Distribution of Fuel Sprays

Science.gov (United States)

Lee, Dana W

1933-01-01

The atomization and distribution characteristics of fuel sprays from automatic injection valves for compression-ignition engines were determined by catching the fuel drops on smoked-glass plates, and then measuring and counting the impressions made in the lampblack. The experiments were made in an air-tight chamber in which the air density was raised to values corresponding to engine conditions.

Experimental analysis on the influence of nozzle geometry over the dispersion of liquid n-dodecane sprays

Directory of Open Access Journals (Sweden)

Raul ePayri

2015-10-01

Full Text Available Understanding and controlling mixing and combustion processes is fundamental in order to face the challenges set by the ever more demanding pollutant regulations and fuel consumption standards of direct injection diesel engines. The fundamentals of these processes haven been long studied by the diesel spray community from both experimental and numerical perspectives. However, certain topics such as the influence of nozzle geometry over the spray atomization, mixing and combustion process are still not completely well understood and predicted by numerical models. The present study seeks to contribute to the current understanding of this subject, by performing state-of-the-art optical diagnostics to liquid sprays injected through two singe-hole nozzles of different conicity. The experiments were carried out in a nitrogen-filled constant-pressure-flow facility. Back pressures were set to produce the desired engine-like density conditions in the chamber, at room temperature. The experimental setup consists in a diffused back illumination setup with a fast pulsed LED light source and a high-speed camera. The diagnostics focused on detecting the liquid spray contour and evaluating the influence of nozzle geometry over the time-resolved and quasi-steady response of the spray dispersion, at similar injection conditions. Results show a clear influence of nozzle geometry on spray contour fluctuations, where the cylindrical nozzle seems to produce larger dispersion in both time-resolved fluctuations and quasi-steady values, when compared to the conical nozzle. This evidences that the turbulence and radial velocity profiles originated at the cylindrical nozzle geometry are able to affect not only the microscopic scales inside the nozzle, but also macroscopic scales such as the steady spray. Observations from this study indicate that the effects of the flow characteristics within the nozzle are carried on to the first millimeters of the spray, in which the

Batch top-spray fluid bed coating: Scale-up insight using dynamic heat- and mass-transfer modelling

DEFF Research Database (Denmark)

Hede, Peter Dybdahl; Bach, P.; Jensen, Anker Degn

2009-01-01

A mathematical model was developed for batch top-spray fluid bed coating processes based on Ronsse et al. [2007a.b. Combined population balance and thermodynamic modelling of the batch top-spray fluidised bed coating process. Part I-model development and validation. journal of Food Engineering 78......, 296-307; Combined population balance and thermodynamic modelling of the batch top-spray fluidised bed coating process. Part II-model and process analysis. journal of Food Engineering 78, 308-322]. The model is based on one-dimensional discretisation of the fluid bed into a number of well-mixed control......-up principles by comparing simulation results with experimental temperature and humidity data obtained from inorganic salt coating of placebo cores in three pilot fluid bed scales being a 0.5kg small-scale (GEA Aeromatic-Fielder Strea-1), 4kg medium-scale (GEA Niro MP-1) and 24kg large-scale (GEA MP-2...

Particle emission rates during electrostatic spray deposition of TiO2 nanoparticle-based photoactive coating.

Science.gov (United States)

Koivisto, Antti J; Jensen, Alexander C Ø; Kling, Kirsten I; Kling, Jens; Budtz, Hans Christian; Koponen, Ismo K; Tuinman, Ilse; Hussein, Tareq; Jensen, Keld A; Nørgaard, Asger; Levin, Marcus

2018-01-05

Here, we studied the particle release rate during Electrostatic spray deposition of anatase-(TiO 2 )-based photoactive coating onto tiles and wallpaper using a commercially available electrostatic spray device. Spraying was performed in a 20.3m 3 test chamber while measuring concentrations of 5.6nm to 31μm-size particles and volatile organic compounds (VOC), as well as particle deposition onto room surfaces and on the spray gun user hand. The particle emission and deposition rates were quantified using aerosol mass balance modelling. The geometric mean particle number emission rate was 1.9×10 10 s -1 and the mean mass emission rate was 381μgs -1 . The respirable mass emission-rate was 65% lower than observed for the entire measured size-range. The mass emission rates were linearly scalable (±ca. 20%) to the process duration. The particle deposition rates were up to 15h -1 for deposited particles consisted of mainly TiO 2 , TiO 2 mixed with Cl and/or Ag, TiO 2 particles coated with carbon, and Ag particles with size ranging from 60nm to ca. 5μm. As expected, no significant VOC emissions were observed as a result of spraying. Finally, we provide recommendations for exposure model parameterization. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

An investigation on effect of geometrical parameters on spray cone angle and droplet size distribution of a two-fluid atomizer

Energy Technology Data Exchange (ETDEWEB)

Shafaee, Maziar; Banitabaei, Sayed Abdolhossein; Esfahanian, Vahid; Ashjaee, Mehdi [Tehran University, Tehran (Iran, Islamic Republic of)

2011-12-15

A visual study is conducted to determine the effect of geometrical parameters of a two-fluid atomizer on its spray cone angle. The liquid (water) jets exit from six peripheral inclined orifices and are introduced to a high speed gas (air) stream in the gravitational direction. Using a high speed imaging system, the spray cone angle has been determined in constant operational conditions, i.e., Reynolds and Weber numbers for different nozzle geometries. Also, the droplet sizes (Sauter mean diameter) and their distributions have been determined using Malvern Master Sizer x. The investigated geometrical parameters are the liquid jet diameter, liquid port angle and the length of the gas-liquid mixing chamber. The results show that among these parameters, the liquid jet diameter has a significant effect on spray cone angle. In addition, an empirical correlation has been obtained to predict the spray cone angle of the present two-fluid atomizer in terms of nozzle geometries.

Spray cooling

International Nuclear Information System (INIS)

Rollin, Philippe.

1975-01-01

Spray cooling - using water spraying in air - is surveyed as a possible system for make-up (peak clipping in open circuit) or major cooling (in closed circuit) of the cooling water of the condensers in thermal power plants. Indications are given on the experiments made in France and the systems recently developed in USA, questions relating to performance, cost and environmental effects of spray devices are then dealt with [fr

Spray boom for selectively spraying a herbicidal composition onto dicots

DEFF Research Database (Denmark)

2012-01-01

There is provided a method and spray boom for discriminating cereal crop (monocot) and weeds (dicots). The spray boom includes means for digitally recording an image of a selected area to be treated by a nozzle on the spray boom, whereby a plant material is identified based on a segmentation proc...

Reduction of spray pressure leads to less emission and better deposition of spray liquid at high-volume spraying in greenhouse tomato

NARCIS (Netherlands)

Os, van E.A.; Michielsen, J.M.G.P.; Corver, F.J.M.; Berg, van den J.V.; Bruins, M.A.; Porskamp, H.A.J.; Zande, van de J.C.

2005-01-01

In an experimental greenhouse, growing a tomato crop, it was investigated if a reduction in spray pressure could improve the spray result, while, simultaneously, emission to the ground could be reduced. Spray deposition on the leaves and the emission to the ground was evaluated at different spray

Spray and evaporation characteristics of ethanol and gasoline direct injection in non-evaporating, transition and flash-boiling conditions

International Nuclear Information System (INIS)

Huang, Yuhan; Huang, Sheng; Huang, Ronghua; Hong, Guang

2016-01-01

Highlights: • Sprays can be considered as non-evaporating when vapour pressure is lower than 30 kPa. • Ethanol direct injection should only be applied in high temperature engine environment. • Gasoline spray collapses at lower fuel temperature (350 K) than ethanol spray does (360 K). • Flash-boiling does not occur when fuel temperature reaches boiling point until ΔT is 14 K. • Not only spray evaporation mode but also breakup mechanism change with fuel temperature. - Abstract: Ethanol direct injection plus gasoline port injection (EDI + GPI) represents a more efficient and flexible way to utilize ethanol fuel in spark ignition engines. To exploit the potentials of EDI, the mixture formation characteristics need to be investigated. In this study, the spray and evaporation characteristics of ethanol and gasoline fuels injected from a multi-hole injector were investigated by high speed Shadowgraphy imaging technique in a constant volume chamber. The experiments covered a wide range of fuel temperature from 275 K (non-evaporating) to 400 K (flash-boiling) which corresponded to cold start and running conditions in an engine. The spray transition process from normal-evaporating to flash-boiling was investigated in greater details than the existed studies. Results showed that ethanol and gasoline sprays demonstrated the same patterns in non-evaporating conditions. The sprays could be considered as non-evaporating when vapour pressure was lower than 30 kPa. Ethanol evaporated more slowly than gasoline did in low temperature environment, but they reached the similar evaporation rates when temperature was higher than 375 K. This suggested that EDI should only be applied in high temperature engine environment. For both ethanol and gasoline sprays, when the excess temperature was smaller than 4 K, the sprays behaved the same as the subcooled sprays did. The sprays collapsed when the excess temperature was 9 K. Flash-boiling did not occur until the excess temperature

Optimization of combustion chamber geometry for stoichiometric diesel combustion using a micro genetic algorithm

Energy Technology Data Exchange (ETDEWEB)

Park, Sung Wook

2010-11-15

This paper describes the optimization of combustion chamber geometry and engine operating conditions for stoichiometric diesel combustion, targeting lower gross indicated specific fuel consumption. The KIVA code, coupled with a micro genetic algorithm population of nine for each generation was used. The optimization variables were composed of ten variables related to the combustion chamber geometry and engine operating conditions. In addition, an auto mesh generator was developed for generating various kinds of combustion chambers, such as open-crater, re-entrant, deep, and shallow types. In addition, the computational models were validated against the experimental results for a stoichiometric process in terms of the combustion pressure history and emissions. Through the preset optimization, a 35% improvement in the gross indicated that specific fuel consumption was achieved. In addition, the optimization results showed that the optimum engine operating conditions employed a premixed charge compression ignition combustion regime with early injection and a narrow spray included angle. Furthermore, a higher boost pressure was used to prevent fuel film formation. (author)

Defining the Cubature Changes of Historic St. Kinga Chamber in Bochnia Salt Mine, Using Laser Scanning Technology

Science.gov (United States)

Szafarczyk, Anna; Gawałkiewicz, Rafał

2018-03-01

In Poland, there are many mining enterprises, of historic character registered in the UNESCO World Heritage List. One of the oldest mining enterprises in Poland is the Salt Mine in Bochnia. The processes inside the rock mass require that surveying services carry out regular geometric control of the cavities. A particular attention should be paid (due to its sacral function) on St. Kinga Chamber, located 195 metres below the surface, on the mine level "August". So far measurement technologies have been connected with the studies on changes in the geometry of cavities and based on linear bases used to measure convergence. This only provides discrete information (in a point) and not always presents a real state of deformation. In the scanning method, in practice a three dimension image of changes (structural deformations) is obtained, impossible to determine with the application of measurement methods, applied to measure the value of linear convergence (the method with a limited number of bases). Laser scanning, apart from determining the value of volume convergence, gives also the possibility of the visualization of 3D cavern. Moreover, it provides direct information to update mining numerical maps and make it possible to generate various cross-sections through the cavern. The authors analysed the possibility of the application of laser scanning (scanner Faro Focus 3D), as a modern tool allowing the measuring of the value of volume convergence.

Effects of nozzle type and spray angle on spray deposition in ivy pot plants.

Science.gov (United States)

Foqué, Dieter; Nuyttens, David

2011-02-01

Fewer plant protection products are now authorised for use in ornamental growings. Frequent spraying with the same product or a suboptimal technique can lead to resistance in pests and diseases. Better application techniques could improve the sustainable use of the plant protection products still available. Spray boom systems--instead of the still predominantly used spray guns--might improve crop protection management in greenhouses considerably. The effect of nozzle type, spray pressure and spray angle on spray deposition and coverage in ivy pot plants was studied, with a focus on crop penetration and spraying the bottom side of the leaves in this dense crop. The experiments showed a significant and important effect of collector position on deposition and coverage in the plant. Although spray deposition and coverage on the bottom side of the leaves are generally low, they could be improved 3.0-4.9-fold using the appropriate application technique. When using a spray boom in a dense crop, the nozzle choice, spray pressure and spray angle should be well considered. The hollow-cone, the air-inclusion flat-fan and the standard flat-fan nozzle with an inclined spray angle performed best because of the effect of swirling droplets, droplets with a high momentum and droplet direction respectively. Copyright © 2010 Society of Chemical Industry.

Nanostructured thin film La{sub 0.6}Sr{sub 0.4}CoO{sub 3-δ} synthesized via salt-assisted spray pyrolysis for micro-SOFC application

Energy Technology Data Exchange (ETDEWEB)

Benel, Cahit; Darbandi, Azad J. [Institute for Nanotechnology, Karlsruhe Institute of Technology (Germany); Joint Research Laboratory Nanomaterials/Technische Universitaet Darmstadt and Karlsruhe Institute of Technology (Germany); Center for Functional Nanostructures, Karlsruhe Institute of Technology (Germany); Evans, Anna; Toelke, Rene [Nonmetallic Inorganic Materials, Department of Materials, ETH Zurich (Switzerland); Hahn, Horst [Institute for Nanotechnology, Karlsruhe Institute of Technology (Germany); Joint Research Laboratory Nanomaterials/Technische Universitaet Darmstadt and Karlsruhe Institute of Technology (Germany)

2012-07-01

Micro-solid oxide fuel cells (micro-SOFCs) are anticipated for battery replacement due to their increased energy capacity for applications such as portable electronic devices, mobile phones and laptops. In this work, nanocrystalline La{sub 0.6}Sr{sub 0.4}CoO{sub 3-δ} (LSC) powder with ultrafine microstructure and high specific surface area was synthesized via salt-assisted spray pyrolysis method. XRD results show the formation of a nanocrystalline single phase perovskite structure. Agglomerate-free LSC nanoparticles were stabilized in water-based dispersion without the need of ultrasonic energy application. Nanoparticulate cathode thin films of LSC with thickness between 150 and 500 nm were prepared via single step spin coating on yttria stabilized zirconia (YSZ) substrates. Gadolinium doped ceria (GDC) film was applied to YSZ substrate to avoid the chemical reaction between cathode and electrolyte. The performance of the thin film cathodes was evaluated by high temperature impedance spectroscopy on symmetrical samples.

Fuel temperature influence on diesel sprays in inert and reacting conditions

International Nuclear Information System (INIS)

Payri, Raul; García-Oliver, Jose M.; Bardi, Michele; Manin, Julien

2012-01-01

The detailed knowledge of the evaporation–combustion process of the Diesel spray is a key factor for the development of robust injection strategies able to reduce the pollutant emissions and keep or increase the combustion efficiency. In this work several typical measurement applied to the diesel spray diagnostic (liquid length, lift-off length and ignition delay) have been employed in a novel continuous flow test chamber that allows an accurate control on a wide range of thermodynamic test conditions (up to 1000 K and 15 MPa). A step forward in the control of the test boundary conditions has been done employing a special system to study the fuel temperature effect on the evaporation and combustion of the spray. The temperature of the injector body has been controlled with a thermostatic system and the relationship between injector body and fuel temperature has been observed experimentally. Imaging diagnostics have been employed to visualize the liquid phase penetration in evaporative/inert conditions and, lift-off length and ignition delay in reactive condition. The results underline a clear influence of the injector body temperature on both conditions, evaporative and, in a lesser degree, reactive; finally the physical models found in the literature have been compared with the results obtained experimentally. - Highlights: ► The effect of the fuel temperature is substantial on liquid length (up to 15%). ► Fuel temperature has low effect but still appreciable on LOL and ignition delay. ► Theoretical one dimensional spray models are able to reproduce the experimental results with good accuracy.

Spray combustion of biomass-based renewable diesel fuel using multiple injection strategy in a constant volume combustion chamber

KAUST Repository

Jing, Wei; Wu, Zengyang; Roberts, William L.; Fang, Tiegang

2016-01-01

Effect of a two-injection strategy associated with a pilot injection on the spray combustion process was investigated under conventional diesel combustion conditions (1000 K and 21% O2 concentration) for a biomass-based renewable diesel fuel, i

Chamber technology concepts for inertial fusion energy: Three recent examples

International Nuclear Information System (INIS)

Meier, W.R.; Moir, R.W.; Abdou, M.A.

1997-01-01

The most serious challenges in the design of chambers for inertial fusion energy (IFE) are 1) protecting the first wall from fusion energy pulses on the order of several hundred megajoules released in the form of x rays, target debris, and high energy neutrons, and 2) operating the chamber at a pulse repetition rate of 5-10 Hz (i.e., re-establishing, the wall protection and chamber conditions needed for beam propagation to the target between pulses). In meeting these challenges, designers have capitalized on the ability to separate the fusion burn physics from the geometry and environment of the fusion chamber. Most recent conceptual designs use gases or flowing liquids inside the chamber. Thin liquid layers of molten salt or metal and low pressure, high-Z gases can protect the first wall from x rays and target debris, while thick liquid layers have the added benefit of protecting structures from fusion neutrons thereby significantly reducing the radiation damage and activation. The use of thick liquid walls is predicted to 1) reduce the cost of electricity by avoiding the cost and down time of changing damaged structures, and 2) reduce the cost of development by avoiding the cost of developing a new, low-activation material. Various schemes have been proposed to assure chamber clearing and renewal of the protective features at the required pulse rate. Representative chamber concepts are described, and key technical feasibility issues are identified for each class of chamber. Experimental activities (past, current, and proposed) to address these issues and technology research and development needs are discussed

A Comparison of Effects of Ambient Pressure on the Atomization Performance of Soybean Oil Methyl Ester and Dimethyl Ether Sprays Comparaison des effets de la pression ambiante sur l’atomisation en “spray” de methylester d’huile de soja et de dimethyléther

Directory of Open Access Journals (Sweden)

Kim H.J.

2010-11-01

Full Text Available The purpose of this study is the experimental investigation of Soybean oil Methyl Ester (SME and DiMethyl Ether (DME spray characteristics injected through the common-rail injection system under various ambient pressures. A high pressure chamber that can be pressurized up to 4 MPa was utilized for a change of ambient pressure. In order to compare the spray development and atomization characteristics, the images of SME and DME were obtained by using a high speed camera with two metal halide lamps under various ambient pressures in the spray chamber. From these spray images, the spray characteristics such as the spray penetration from the nozzle tip, maximum radial distance, and spray diameter were measured and analyzed. In addition, the Sauter Mean Diameter (SMD of two fuels under ambient pressure was analyzed using the droplet measuring system. It was revealed that the axial distance of spray from the nozzle tip of the SME spray is longer than that of DME spray under same injection condition. The axial penetration, maximum radial distance, and spray diameter decreased when the ambient pressure in the chamber increased. As the ambient pressure increased, the SMD decreased and the DME spray showed a superior atomization performance compared to the SME spray. Le but de cette étude est l’investigation expérimentale de l’effet de diverses pressions ambiantes sur les caractéristiques des sprays (issus d’un système "common rail" de methylester d’huile de soja (SME et de dimethyléther (DME. La pression ambiante dépend de la chambre et sa valeur la plus haute peut monter jusqu’à 4 MPa. Pour comparer le développement de spray et la caractéristique d’atomisation, des images de spray de SME et DME à différentes pression ambiantes sont obtenues avec une caméra à haute vitesse à deux lampes de métal halide. Les caractéristiques du spray, comme la pénétration, la distance radiale maximale et le diamètre de spray, sont mesur

Limitations on the use of the planar laser induced exciplex fluorescence technique in diesel sprays

Energy Technology Data Exchange (ETDEWEB)

J.M. Desantes; J.V. Pastor; J.M. Pastor; J.E. Julia [Universidad Politecnica de Valencia, Valencia (Spain). CMT Motores Termicos

2005-12-01

The Planar Laser Induced Exciplex Fluorescence (PLIEF) technique is widely used to visualize and measure the fuel concentration fields in both liquid and vapor phases of DI Diesel sprays. However, the real limitations of the PLIEF technique in Diesel sprays and the accuracy of the results obtained are still a source of controversy. In this work, a complete methodology for maximum penetration and fuel concentration measurements in evaporating conditions in Diesel sprays has been developed and the reliability of the results obtained has been investigated. The methodology includes new procedures for measuring both liquid and vapor phases, adapting, when necessary, correlations available in the literature for calibration. An experimental matrix of nine test points with different injection pressures and combustion chamber densities has been performed. A critical analysis of the different error sources for proper quantification is made. Results have shown that macroscopic features can be accurately determined using the PLIEF technique, but for fuel concentration measurements special considerations have to be taken into account, particularly in the regions where liquid and vapor coexist. 37 refs., 15 figs., 2 tabs.

Particulate pollutants are capable to ‘degrade’ epicuticular waxes and to decrease the drought tolerance of Scots pine (Pinus sylvestris L.)

International Nuclear Information System (INIS)

Burkhardt, Juergen; Pariyar, Shyam

2014-01-01

Air pollution causes the amorphous appearance of epicuticular waxes in conifers, usually called wax ‘degradation’ or ‘erosion’, which is often correlated with tree damage symptoms, e.g., winter desiccation. Previous investigations concentrated on wax chemistry, with little success. Here, we address the hypothesis that both ‘wax degradation’ and decreasing drought tolerance of trees may result from physical factors following the deposition of salt particles onto the needles. Pine seedlings were sprayed with dry aerosols or 50 mM solutions of different salts. The needles underwent humidity changes within an environmental scanning electron microscope, causing salt expansion on the surface and into the epistomatal chambers. The development of amorphous wax appearance by deliquescent salts covering tubular wax fibrils was demonstrated. The minimum epidermal conductance of the sprayed pine seedlings increased. Aerosol deposition potentially ‘degrades’ waxes and decreases tree drought tolerance. These effects have not been adequately considered thus far in air pollution research. Highlights: • Demonstrated capability of particles to produce ‘wax degradation’. • Dynamics of particles on pine needles, shown by videos. • Salt particles sprayed on pine needles increased minimum epidermal conductance g min . • Results strongly suggest direct link between air pollution and drought tolerance. • Linkage between different types of forest decline is suggested. -- ‘Wax degradation’ on pine needles and increased minimum epidermal conductance (i.e. uncontrollable water loss) were created by particles, suggesting a link between air pollution and tree drought tolerance

A study of transient jet and spray using a Schlieren method and digital image processing

Energy Technology Data Exchange (ETDEWEB)

Paulsen, H.

1995-12-31

This thesis discusses visualization and image-based data acquisition and analyses on transient gas jet, evaporating spray and burning jet in an attempt to find a method of measuring the transient behaviour of these phenomena, which influence the combustion process in diesel engines. The experimental approach is based on visualization of the injection process inside a constant volume air chamber. The influence of different experimental conditions such as fuel type, injection conditions, temperature and pressure of the chamber is investigated. To control the dynamics of the injection, a constant pressure injection system is used. The dynamics of the fuel injection system itself is not discussed. A full-field classical Schlieren technique is used, and the data recorded by means of a CCD camera and frame-grabber combination. The method has the unusual property of being particularly useful for measurements on a dynamic system, since the gradients in the light refraction index used by the Schlieren method are enhanced by the dynamics. The method was used to measure local gas concentration inside a room temperature methane gas jet, and vapour phase concentration evaporating propane spray. The system was also used to measure the local temperature of burning methane jet based on calculated density distribution. 47 refs., 92 figs., 3 tabs.

Hot melt extrusion versus spray drying: hot melt extrusion degrades albendazole.

Science.gov (United States)

Hengsawas Surasarang, Soraya; Keen, Justin M; Huang, Siyuan; Zhang, Feng; McGinity, James W; Williams, Robert O

2017-05-01

The purpose of this study was to enhance the dissolution properties of albendazole (ABZ) by the use of amorphous solid dispersions. Phase diagrams of ABZ-polymer binary mixtures generated from Flory-Huggins theory were used to assess miscibility and processability. Forced degradation studies showed that ABZ degraded upon exposure to hydrogen peroxide and 1 N NaOH at 80 °C for 5 min, and the degradants were albendazole sulfoxide (ABZSX), and ABZ impurity A, respectively. ABZ was chemically stable following exposure to 1 N HCl at 80 °C for one hour. Thermal degradation profiles show that ABZ, with and without Kollidon ® VA 64, degraded at 180 °C and 140 °C, respectively, which indicated that ABZ could likely be processed by thermal processing. Following hot melt extrusion, ABZ degraded up to 97.4%, while the amorphous ABZ solid dispersion was successfully prepared by spray drying. Spray-dried ABZ formulations using various types of acids (methanesulfonic acid, sulfuric acid and hydrochloric acid) and polymers (Kollidon ® VA 64, Soluplus ® and Eudragit ® E PO) were studied. The spray-dried ABZ with methanesulfonic acid and Kollidon ® VA 64 substantially improved non-sink dissolution in acidic media as compared to bulk ABZ (8-fold), physical mixture of ABZ:Kollidon ® VA 64 (5.6-fold) and ABZ mesylate salt (1.6-fold). No degradation was observed in the spray-dried product for up to six months and less than 5% after one-year storage. In conclusion, amorphous ABZ solid dispersions in combination with an acid and polymer can be prepared by spray drying to enhance dissolution and shelf-stability, whereas those made by melt extrusion are degraded.

Eddy Covariance Measurements of the Sea-Spray Aerosol Flu

Science.gov (United States)

Brooks, I. M.; Norris, S. J.; Yelland, M. J.; Pascal, R. W.; Prytherch, J.

2015-12-01

Historically, almost all estimates of the sea-spray aerosol source flux have been inferred through various indirect methods. Direct estimates via eddy covariance have been attempted by only a handful of studies, most of which measured only the total number flux, or achieved rather coarse size segregation. Applying eddy covariance to the measurement of sea-spray fluxes is challenging: most instrumentation must be located in a laboratory space requiring long sample lines to an inlet collocated with a sonic anemometer; however, larger particles are easily lost to the walls of the sample line. Marine particle concentrations are generally low, requiring a high sample volume to achieve adequate statistics. The highly hygroscopic nature of sea salt means particles change size rapidly with fluctuations in relative humidity; this introduces an apparent bias in flux measurements if particles are sized at ambient humidity. The Compact Lightweight Aerosol Spectrometer Probe (CLASP) was developed specifically to make high rate measurements of aerosol size distributions for use in eddy covariance measurements, and the instrument and data processing and analysis techniques have been refined over the course of several projects. Here we will review some of the issues and limitations related to making eddy covariance measurements of the sea spray source flux over the open ocean, summarise some key results from the last decade, and present new results from a 3-year long ship-based measurement campaign as part of the WAGES project. Finally we will consider requirements for future progress.

Global modelling of direct and indirect effects of sea spray aerosol using a source function encapsulating wave state

Directory of Open Access Journals (Sweden)

A.-I. Partanen

2014-11-01

Full Text Available Recently developed parameterizations for the sea spray aerosol source flux, encapsulating wave state, and its organic fraction were incorporated into the aerosol–climate model ECHAM-HAMMOZ to investigate the direct and indirect radiative effects of sea spray aerosol particles. Our simulated global sea salt emission of 805 Tg yr−1 (uncertainty range 378–1233 Tg yr−1 was much lower than typically found in previous studies. Modelled sea salt and sodium ion concentrations agreed relatively well with measurements in the smaller size ranges at Mace Head (annual normalized mean model bias −13% for particles with vacuum aerodynamic diameter Dva Da Da Da −2, in contrast to previous studies. This positive effect was ascribed to the tendency of sea salt aerosol to suppress both the in-cloud supersaturation and the formation of cloud condensation nuclei from sulfate. These effects can be accounted for only in models with sufficiently detailed aerosol microphysics and physics-based parameterizations of cloud activation. However, due to a strong negative direct effect, the simulated effective radiative forcing (total radiative effect was −0.2 W m−2. The simulated radiative effects of the primary marine organic emissions were small, with a direct effect of 0.03 W m−2 and an indirect effect of −0.07 W m−2.

Macroscopic Properties of Hollow Cone Spray Using an Outwardly Opening Piezoelectric Injector in GCI Engine

KAUST Repository

Cheng, Penghui

2016-07-01

Fuel mixture formation and spray characteristics are crucial for the advancement of Gasoline Compression Ignition (GCI) engine. For investigations of spray characteristics, a high-pressure high-temperature spray chamber with constant volume has been designed, tested and commissioned at CCRC, KAUST. Back light illumination technique has been applied to investigate the macroscopic spray properties of an outwardly opening piezoelec- tric injector. Three parameters including injection pressure, ambient pressure, and ambient temperature have been involved. A total of 18 combinations of experimental conditions were tested under non-reactive conditions. Through qualitative analysis of spray morphology under different operating conditions, an apparent distinction of spray morphology has been noticed. Spray morphology and propagation have shown strong dependencies on ambient pressure and ambient tempera- ture while injection pressure has a negligible effect on spray shape. Increasingly compact and bushier spray patterns were observed in the cases of high ambient pressure due to in- creasing aerodynamic drag force on spray boundary. It should also be noted that ambient temperature plays a fairly important role in fuel evaporation rate. At 200 °C, oscillating and considerably short spray shape was produced. Also, circumferential ring-like vortices and distinctive string-like structures have been identified for the fuel spray exiting this hollow cone injector. It has been observed that high ambient pressure conditions (Pamb = 4 bar and 10.5 bar) are favorable to the vortices generation, which has also been reported in previous literature. The quantitative description of macroscopic spray properties reveals that ambient pres- sure and ambient temperature are found to be the most influential parameters on liquid penetration length. The rise of ambient pressure results in considerably shorter liquid pen- etration length. Ambient temperature also appears to be a very effective

Effect of salicylic acid on the growth photosynthesis and carbohydrate metabolism in salt stressed maize plants

International Nuclear Information System (INIS)

Moussa, H.R.; Khodary, S.E.A.

2003-01-01

Aqueous solutions of salicylic acid as a spray to Na CI-treated corn (Zea mays L,) significantly increased the growth of shoots and roots as measured after seven days of treatment. Spraying of salicylic acid caused significant increases in the activity of both ribulose 1,5 bisphosphate carboxylase (rubisco) enzyme and photosynthetic pigments. Moreover, salicylic acid treatment induced high values of soluble carbohydrate fractions in salt stressed plants as compared with salicylic acid treated samples. These data suggest that salicylic acid might improve the growth pattern of NaCl-treated maize plants via increasing the rate of photosynthesis and carbohydrate metabolism

Measurement of electro-sprayed 238 and 239+240 plutonium isotopes using 4π-alpha spectrometry. Application to environmental samples

International Nuclear Information System (INIS)

Charmoille-Roblot, M.

1999-01-01

A new protocol for plutonium deposition using the electro-spray technique coupled with 4π-α spectrometry is proposed to improve the detection limit, shorten the counting time. In order to increase the detection efficiency, it was proposed to measure 238 and 239+240 plutonium isotopes electro-sprayed deposit simultaneously on both sides of the source support, that must be as transparent as possible to alpha-emissions, in a two-alpha detectors chamber. A radiochemical protocol was adapted to electro-spray constraints and a very thin carbon foil was selected for 4π -alpha spectrometry. The method was applied to a batch of sediment samples and gave the same results as an electrodeposited source measured using conventional alpha spectrometry with a 25 % gain on counting time and 10 % on plutonium 238 detection limit. Validation and application of the technique have been made on reference samples. (author)

Wear and Corrosion Properties of 316L-SiC Composite Coating Deposited by Cold Spray on Magnesium Alloy

Science.gov (United States)

Chen, Jie; Ma, Bing; Liu, Guang; Song, Hui; Wu, Jinming; Cui, Lang; Zheng, Ziyun

2017-08-01

In order to improve the wear and corrosion resistance of commonly used magnesium alloys, 316L stainless steel coating and 316L-SiC composite coating have been deposited directly on commercial AZ80 magnesium alloy using cold spraying technology (CS). The microstructure, hardness and bonding strength of as-sprayed coatings were studied. Their tribological properties sliding against Si3N4 and GCr15 steel under unlubricated conditions were evaluated by a ball-on-disk tribometer. Corrosion behaviors of coated samples were also evaluated and compared to that of uncoated magnesium alloy substrate in 3.5 wt.% NaCl solution by electrochemical measurements. Scanning electron microscopy was used to characterize the corresponding wear tracks and corroded surfaces to determine wear and corrosion mechanisms. The results showed that the as-sprayed coatings possessed higher microhardness and more excellent wear resistance than magnesium alloy substrate. Meanwhile, 316L and 316L-SiC coating also reduced the corrosion current density of magnesium alloy and the galvanic corrosion of the substrates was not observed after 200-h neutral salt spray exposure, which demonstrated that corrosion resistance of a magnesium alloy substrate could be greatly improved by cold-sprayed stainless steel-based coatings.

One-step large-scale deposition of salt-free DNA origami nanostructures

Science.gov (United States)

Linko, Veikko; Shen, Boxuan; Tapio, Kosti; Toppari, J. Jussi; Kostiainen, Mauri A.; Tuukkanen, Sampo

2015-01-01

DNA origami nanostructures have tremendous potential to serve as versatile platforms in self-assembly -based nanofabrication and in highly parallel nanoscale patterning. However, uniform deposition and reliable anchoring of DNA nanostructures often requires specific conditions, such as pre-treatment of the chosen substrate or a fine-tuned salt concentration for the deposition buffer. In addition, currently available deposition techniques are suitable merely for small scales. In this article, we exploit a spray-coating technique in order to resolve the aforementioned issues in the deposition of different 2D and 3D DNA origami nanostructures. We show that purified DNA origamis can be controllably deposited on silicon and glass substrates by the proposed method. The results are verified using either atomic force microscopy or fluorescence microscopy depending on the shape of the DNA origami. DNA origamis are successfully deposited onto untreated substrates with surface coverage of about 4 objects/mm2. Further, the DNA nanostructures maintain their shape even if the salt residues are removed from the DNA origami fabrication buffer after the folding procedure. We believe that the presented one-step spray-coating method will find use in various fields of material sciences, especially in the development of DNA biochips and in the fabrication of metamaterials and plasmonic devices through DNA metallisation. PMID:26492833

Influence of solvent on the morphology and microstructure of YSZ films obtained by spray pyrolysis technique

International Nuclear Information System (INIS)

Falcade, T.; Oliveira, G.B.; Mueller, I.L.; Malfatti, C.F.

2010-01-01

This work aims to investigate the influence of solvent used for the deposition of thin films of yttria stabilized zirconia (YSZ) on porous substrate. The films were obtained directly on the porous LSM substrate by spray pyrolysis technique, which consists of spraying a precursor solution containing salts of zirconium (Zr (C 6 H 7 O 2 ) 4) and yttrium (YCl 3 .6H 2 O), dissolved in specific solvents, on the heated substrate. The use of solvents with different boiling points and viscosity aims the optimization of experimental operating parameters to obtain homogeneous and dense films suitable for application as electrolyte in fuel cells, solid oxide (SOFC). The films were characterized by scanning electron microscopy, infrared spectroscopy and X-ray diffraction. (author)

Synchronized droplet size measurements for Coal-Water-Slurry (CWS) diesel sprays of an electronically-controlled fuel injection system

Science.gov (United States)

Kihm, K. D.; Terracina, D. P.; Payne, S. E.; Caton, J. A.

Experiments were completed to study intermittent coal-water slurry (CWS) fuel sprays injected from an electronically-controlled accumulator injector system. A laser diffraction particle analyzing (LDPA) technique was used to measure the spray diameters (Sauter mean diameter, SMD) assuming the Rosin-Rammler two parameter model. In order to ensure an accurate synchronization of the measurement with the intermittent sprays, a new synchronization technique was developed using the light extinction signal as a triggering source for the data taking initiation. This technique allowed measurement of SMD's near the spray tip where the light extinction was low and the data were free from the multiscattering bias. Coal-water slurry fuel with 50% coal loading in mass containing 5 (mu)m mass median diameter coal particulates was considered. Injection pressures ranging from 28 to 110 MPa, two different nozzle orifice diameters, 0.2 ad 0.4 mm, and four axial measurement locations from 60 to 120 mm from the nozzle orifice were studied. Measurements were made for pressurized (2.0 MPa in gauge) and for ambient chamber conditions. The spray SMD showed an increase with the distance of the axial measurement location and with the ambient gas density, and showed a decrease with increasing injection pressure. A correlation of the Sauter mean diameter with the injection conditions was determined. The results were also compared with previous SMD correlations that were available only for diesel fuel sprays.

Foliar spray of sodium antagonistic essential mineral elements- a technique to induce salt tolerance in plants growing under saline environment (abstract)

International Nuclear Information System (INIS)

Ahmad, R.; Jabeen, R.

2005-01-01

Plants growing at saline substrate practice deficiencies in absorption of some essential mineral elements through roots due to presence of excessive sodium in rhizosphere. Sodium being antagonistic to other cations does not let them enter in roots and hence apart from its own toxicity in metabolism, the plants suffer with deficiencies of some mineral elements, which are necessary for growth. Potassium being essential mineral element is much effected due to this antagonistic behavior of sodium ion. Lagenaria siceraria (var. Loki) being a broad leaf vegetable was selected for these experiments. Plant growing at saline substrate was sprayed with specially prepared spray materials containing different dilutions of potassium nitrate. The anatomy of leaf with special reference to that of stomata was also studied to ensure absorption of required minerals. Growth of plants in terms of leaf area is being monitored at present. Some preliminary experiments show betterment in production of fruits in plants undergoing foliar spray. This hypothesis has opened a new chapter demanding series of experiments dealing with recipe of spray materials, mechanism of minerals uptake through stomata, participation of absorbed minerals in metabolic activities around palisade tissue probably by activating potassium dependent enzyme system which otherwise is blocked by replaced sodium, translocation of these minerals from leaves through petiole in rest of plants and overall effect of such spray on vegetative as well as reproductive growth in plants under saline environment. Some of this work is in progress. (author)

Sem-edx and ftir studies of chlorinated rubber coating

International Nuclear Information System (INIS)

Bano, H.; Khan, M.I.

2013-01-01

Summary: Anticorrosive performance of chlorinated rubber coating has been investigated by visual examination, Scanning electron microscopy (SEM)/Energy dispersive X-ray (EDX) analysis and Fourier transform infrared (FTIR) spectroscopy. After surface preparation, commercially available coating system based on chlorinated rubber (primer)/chlorinated rubber (topcoat) formulation was applied on mild steel test panels (10cm x 15cm sizes). Prepared coated panels were exposed at marine, industrial and urban test sites located in Karachi, Pakistan according to ISO 8565 norm. Accelerated testing was performed by using a salt spray chamber (ASTM B117 norm). Accelerated weathering methods are the methods in which the factors responsible for the degradation of coatings are artificially intensified in order to achieve the rapid degradation of coatings. Visual examination of blistering and rusting as well as SEM micrographs indicated a more severe degradation of the coating surface characteristics at natural exposure testing sites (particularly at marine test site) than for accelerated (salt spray) testing. EDX determination of the Oxygen/Carbon (O/C) ratios also indicated increased degradation at natural test sites compared to the accelerated (salt spray) testing. Photooxidation of the binder results in the formation of carbonyl compounds as revealed by FTIR spectroscopy which also indicated dehydrochlorination. (author)

Desorption electro-spray ionization - orbitrap mass spectrometry of synthetic polymers and copolymers

International Nuclear Information System (INIS)

Friia, Manel; Legros, Veronique; Tortajada, Jeanine; Buchmann, William

2012-01-01

Desorption Electro-Spray Ionization (DESI) - Orbitrap Mass Spectrometry (MS) was evaluated as a new tool for the characterization of various industrial synthetic polymers (poly(ethylene glycol), poly(propylene glycol), poly(methylmethacrylate), poly(dimethylsiloxane)) and copolymers, with masses ranging from 500 g.mol -1 up to more than 20000 g.mol -1 . Satisfying results in terms of signal stability and sensitivity were obtained from hydrophobic surfaces (HTC Prosolia) with a mixture water/methanol (10/90) as spray solvent in the presence of sodium salt. Taking into account the formation of multiplied charged species by DESI-MS, a strategy based on the use of a deconvolution software followed by the automatic assignment of the ions was described allowing the rapid determination of Mn, Mw and PDI values. DESI-Orbitrap MS results were compared to those obtained from matrix-assisted laser desorption/ionization- time-of-flight MS and gel permeation chromatography. An application of DESI-Orbitrap MS for the detection and identification of polymers directly from cosmetics was described. (authors)

Defining the Cubature Changes of Historic St. Kinga Chamber in Bochnia Salt Mine, Using Laser Scanning Technology

Directory of Open Access Journals (Sweden)

Szafarczyk Anna

2018-01-01

Full Text Available In Poland, there are many mining enterprises, of historic character registered in the UNESCO World Heritage List. One of the oldest mining enterprises in Poland is the Salt Mine in Bochnia. The processes inside the rock mass require that surveying services carry out regular geometric control of the cavities. A particular attention should be paid (due to its sacral function on St. Kinga Chamber, located 195 metres below the surface, on the mine level “August”. So far measurement technologies have been connected with the studies on changes in the geometry of cavities and based on linear bases used to measure convergence. This only provides discrete information (in a point and not always presents a real state of deformation. In the scanning method, in practice a three dimension image of changes (structural deformations is obtained, impossible to determine with the application of measurement methods, applied to measure the value of linear convergence (the method with a limited number of bases. Laser scanning, apart from determining the value of volume convergence, gives also the possibility of the visualization of 3D cavern. Moreover, it provides direct information to update mining numerical maps and make it possible to generate various cross-sections through the cavern. The authors analysed the possibility of the application of laser scanning (scanner Faro Focus 3D, as a modern tool allowing the measuring of the value of volume convergence.

Plasma Sprayed Hydroxyapatite Coatings: Influence of Spraying Power on Microstructure

International Nuclear Information System (INIS)

Mohd, S. M.; Abd, M. Z.; Abd, A. N.

2010-01-01

The plasma sprayed hydroxyapatite (HA) coatings are used on metallic implants to enhance the bonding between the implant and bone in human body. The coating process was implemented at different spraying power for each spraying condition. The coatings formed from a rapid solidification of molten and partly molten particles that impact on the surface of substrate at high velocity and high temperature. The study was concentrated on different spraying power that is between 23 to 31 kW. The effect of different power on the coatings microstructure was investigated using scanning electron microscope (SEM) and phase composition was evaluated using X-ray diffraction (XRD) analysis. The coatings surface morphology showed distribution of molten, partially melted particles and some micro-cracks. The produced coatings were found to be porous as observed from the cross-sectional morphology. The coatings XRD results indicated the presence of crystalline phase of HA and each of the patterns was similar to the initial powder. Regardless of different spraying power, all the coatings were having similar XRD patterns.

Preliminary Technical and Legal Evaluation of Disposing of Nonhazardous Oil Field Waste into Salt Caverns

National Research Council Canada - National Science Library

Veil, John

1996-01-01

.... These caverns are either created incidentally as a result of salt recovery or intentionally to create an underground chamber that can be used for storing hydrocarbon products or compressed air...

Local deposition of Copper on Aluminum based MWT Back Contact Foil using Cold Spray Technology

Energy Technology Data Exchange (ETDEWEB)

Goris, M.J.A.A.; Bennett, I.J.; Eerenstein, W. [ECN Solar Energy, Petten (Netherlands)

2013-11-15

MWT cell and module technology has been shown to result in modules with up to 5% higher power output than H-pattern modules and to be suitable for use with thin and fragile cells. In this study, the use of a low cost conductive back-sheet with aluminium as the current carrier in combination with locally applied copper (5 to 30 {mu}m) using the cold spray method is benchmarked against a standard PVF-PET-copper foil in 2 x 2 cell modules. Cell to module losses and reliability during climate chamber tests according to IEC61215 ed. 2, are comparable to module made with the standard foil. Optimizing the cold spray process can result in a cost reduction of more than a factor 10 of the current carrying component, when compared to a full copper conductive back-sheet foil.

Design optimization of twin-fluid atomizers with an internal mixing chamber for heavy fuel oils

Energy Technology Data Exchange (ETDEWEB)

Ferreira, German; Garcia, Juan Antonio; Barreras, Felix; Lozano, Antonio [LITEC, CSIC - Univ. Zaragoza, Maria de Luna 10, 50018 - Zaragoza (Spain); Lincheta, Eduardo [CECYEN, Universidad de Matanzas, Highway to Varadero, km 31/2, 44740 - Matanzas (Cuba)

2009-02-15

The present work is devoted to determine the magnitude of the main parameters that yield the optimum results for twin-fluid nozzles with an internal mixing chamber. The focus is placed on the study of the interaction of both air and liquid flows at the internal chamber and its effects on the resulting spray. To this end, some experiments have been performed for different air central channel diameters and liquid ports, as well as for several experimental conditions (air and liquid mass flow rates), in order to understand the influence of the flow conditions at the mixing chamber on the size of the droplets produced. It has been demonstrated that under certain experimental conditions the atomizing fluid discharged to the internal chamber is choked. The sonic condition is achieved for different air and liquid mass flow rates as a function of the air central channel diameter. It has also been obtained that to achieve the best results with moderate atomizing fluid flow rates, it is convenient to operate in choked conditions. This is an important result that will help in the optimum design of this type of nozzles. (author)

CONCHAS-SPRAY, Reactive Flows with Fuel Sprays

International Nuclear Information System (INIS)

Cloutman, L.D.; Dukowicz, J.K.; Ramshaw, J.D.; Amsden, A.A.

2001-01-01

Description of program or function: CONCHAS-SPRAY solves the equations of transient, multicomponent, chemically reactive fluid dynamics, together with those for the dynamics of an evaporating liquid spray. The program was developed with applications to internal combustion engines in mind. The formulation is spatially two-dimensional, and encompasses both planar and axisymmetric geometries. In the latter case, the flow is permitted to swirl about the axis of symmetry. CONCHAS-SPRAY is a time-marching, finite- difference program that uses a partially implicit numerical scheme. Spatial differences are formed with respect to a generalized two- dimensional mesh of arbitrary quadrilaterals whose corner locations are specified functions of time. This feature allows a Lagrangian, Eulerian, or mixed description, and is particularly useful for representing curved or moving boundary surfaces. Arbitrary numbers of species and chemical reactions are allowed. The latter are subdivided into kinetic and equilibrium reactions, which are treated by different algorithms. A turbulent law-of-the-wall boundary layer option is provided. CONCHAS-SPRAY calls a number of LANL system subroutines to display graphic or numerical information on microfiche. These routines are not included, but are described in the reference report. Several routines called from LINPACK and SLATEC1.0 are included

Fabrication and Microstructure of Hydroxyapatite Coatings on Zirconia by Room Temperature Spray Process.

Science.gov (United States)

Seo, Dong Seok; Chae, Hak Cheol; Lee, Jong Kook

2015-08-01

Hydroxyapatite coatings were fabricated on zirconia substrates by a room temperature spray process and were investigated with regards to their microstructure, composition and dissolution in water. An initial hydroxyapatite powder was prepared by heat treatment of bovine-bone derived powder at 1100 °C for 2 h, while dense zirconia substrates were fabricated by pressing 3Y-TZP powder and sintering it at 1350 °C for 2 h. Room temperature spray coating was performed using a slit nozzle in a low pressure-chamber with a controlled coating time. The phase composition of the resultant hydroxyapatite coatings was similar to that of the starting powder, however, the grain size of the hydroxyapatite particles was reduced to about 100 nm due to their formation by particle impaction and fracture. All areas of the coating had a similar morphology, consisting of reticulated structure with a high surface roughness. The hydroxyapatite coating layer exhibited biostability in a stimulated body fluid, with no severe dissolution being observed during in vitro experimentation.

Concepts and Technologies for Radioactive Waste Disposal in Rock Salt

Directory of Open Access Journals (Sweden)

Wernt Brewitz

2007-01-01

Full Text Available In Germany, rock salt was selected to host a repository for radioactive waste because of its excellent mechanical properties. During 12 years of practical disposal operation in the Asse mine and 25 years of disposal in the disused former salt mine Morsleben, it was demonstrated that low-level wastes (LLW and intermediate-level wastes (ILW can be safely handled and economically disposed of in salt repositories without a great technical effort. LLW drums were stacked in old mining chambers by loading vehicles or emplaced by means of the dumping technique. Generally, the remaining voids were backfilled by crushed salt or brown coal filter ash. ILW were lowered into inaccessible chambers through a borehole from a loading station above using a remote control.Additionally, an in-situ solidification of liquid LLW was applied in the Morsleben mine. Concepts and techniques for the disposal of heat generating high-level waste (HLW are advanced as well. The feasibility of both borehole and drift disposal concepts have been proved by about 30 years of testing in the Asse mine. Since 1980s, several full-scale in-situ tests were conducted for simulating the borehole emplacement of vitrified HLW canisters and the drift emplacement of spent fuel in Pollux casks. Since 1979, the Gorleben salt dome has been investigated to prove its suitability to host the national final repository for all types of radioactive waste. The “Concept Repository Gorleben” disposal concepts and techniques for LLW and ILW are widely based on the successful test operations performed at Asse. Full-scale experiments including the development and testing of adequate transport and emplacement systems for HLW, however, are still pending. General discussions on the retrievability and the reversibility are going on.

In situ analysis of corrosion inhibitors using a portable mass spectrometer with paper spray ionization

KAUST Repository

Jjunju, Fred Paul Mark; Li, Anyin; Badu-Tawiah, Abraham K.; Wei, Pu; Li, Linfan; Ouyang, Zheng; Roqan, Iman S.; Cooks, Robert Graham

2013-01-01

Paper spray (PS) ambient ionization is implemented using a portable mass spectrometer and applied to the detection of alkyl quaternary ammonium salts in a complex oil matrix. These salts are commonly used as active components in the formulation of corrosion inhibitors. They were identified in oil and confirmed by their fragmentation patterns recorded using tandem mass spectrometry (MS/MS). The cations of alkyl and benzyl-substituted quaternary ammonium salts showed characteristic neutral losses of CnH2n (n carbon number of the longest chain) and C7H8, respectively. Individual quaternary ammonium compounds were detected at low concentrations (<1 ng μL-1) and over a dynamic range of ∼5 pg μL-1 to 500 pg μL-1 (ppb). Direct detection of these compounds in complex oil samples without prior sample preparation or pre-concentration was also demonstrated using a home-built miniature mass spectrometer at levels below 1 ng μL-1.© 2013 The Royal Society of Chemistry.

A study on post impingement effects of urea-water solution spray on the heated wall of automotive SCR systems

Science.gov (United States)

Shahariar, G. M. H.; Wardana, M. K. A.; Lim, O. T.

2018-04-01

The post impingement effects of urea-water solution spray on the heated wall of automotive SCR systems was numerically investigated in a constant volume chamber using STAR CCM+ CFD code. The turbulence flow was modelled by realizable k-ε two-layer model together with standard wall function and all y+ treatment was applied along with two-layer approach. The Eulerian-Lagrangian approach was used for the modelling of multi phase flow. Urea water solution (UWS) was injected onto the heated wall for the wall temperature of 338, 413, 473, 503 & 573 K. Spray development after impinging on the heated wall was visualized and measured. Droplet size distribution and droplet evaporation rates were also measured, which are vital parameters for the system performance but still not well researched. Specially developed user defined functions (UDF) are implemented to simulate the desired conditions and parameters. The investigation reveals that wall temperature has a great impact on spray development after impingement, droplet size distribution and evaporation. Increasing the wall temperature leads to longer spray front projection length, smaller droplet size and faster droplet evaporation which are preconditions for urea crystallization reduction. The numerical model and parameters are validated comparing with experimental data.

Thermal Arc Spray Overview

Science.gov (United States)

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.

Thermal Arc Spray Overview

International Nuclear Information System (INIS)

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

2013-01-01

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.

Participation of civil engineers in designing facilities in rock salt

International Nuclear Information System (INIS)

Duddeck, H.; Westhaus, T.

1990-01-01

For the design of underground facilities in rock salt layers or domes, as caverns for repositories, the civil engineering approach may be useful. The underground openings are analysed by determining the displacements and the stresses for actual states and hypothetical situations. The paper reports on the state of art in the development of suited time dependent material laws for rock salt, on time integration methods for the analysis, and on a possible procedure for a consistent safety analysis. The examples given include caverns filled by oil, analysis of a mine with vertical excavation chambers, and dams closing mine galleries. (orig.) [de

MIKROENKAPSULASI Lactobacillus plantarum DENGAN BERBAGAI ENKAPSULAN PADA PENGERINGAN SEMPROT JUS JAMBU BIJI [Microencapsulation of Lactobacillus plantarum in Guava Juice by Spray Drying Using Several Types of Encapsulant

Directory of Open Access Journals (Sweden)

Rina Ningtyas

2015-12-01

Full Text Available Two strains of Lactobacillus plantarum (1% in guava juice were microencapculated by spray drying technique using several types of encapsulant, i.e. maltodextrin, maltodextrin in combination with other materials such as gum arabic, inulin, and galaktooligosakarida (GOS, with a ratio of 5:1. The objectives of this study were to compare the effect of encapsulation materials of Lactobacillus plantarum 2C12 and Lactobacillus plantarum BSL on heat resistance (50, 60 and 70°C, for 20 min, survival at low pH (2.0, bile salts (0.5%, and antimicrobial activity against Escherichia coli. Spray drying were performed at 120°C (inlet and 70°C (outlet. The results showed that all types of encapsulated probiotics improved their resistances toward heat, low pH and bile salts as compared to free cells. The highest survival of probiotic cells was achieved by probiotic encapsulated with maltodextrin, and heated at 50°C, with a protection of 2-3 Log CFU g-1 as compared to free cells. Combination of maltodextrin and GOS (5:1 showed the highest protection toward low pH and bile salts, except for L. plantarum BSL, the best encapsulant was maltodextrin. The antimicrobial activity of microencapsulated probiotic the cells did not change after the microencapsulation process. These results indicate that the guava powder probiotic can be developped by microencapsulation technique using maltodextrin or combination of maltodextrin and GOS with spray drying method.

Hair spray poisoning

Science.gov (United States)

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

Aerosol Formation from High-Pressure Sprays for Supporting the Safety Analysis for the Hanford Waste Treatment and Immobilization Plant - 13183

Energy Technology Data Exchange (ETDEWEB)

Gauglitz, P.A.; Mahoney, L.A.; Schonewill, P.P.; Bontha, J.R.; Blanchard, J.; Kurath, D.E.; Daniel, R.C.; Song, C. [Pacific Northwest National Laboratory, PO Box 999, Richland WA 99352 (United States)

2013-07-01

The Waste Treatment and Immobilization Plant (WTP) at Hanford is being designed and built to pretreat and vitrify waste currently stored in underground tanks at Hanford. One of the postulated events in the hazard analysis for the WTP is a breach in process piping that produces a pressurized spray with small droplets that can be transported into ventilation systems. Literature correlations are currently used for estimating the generation rate and size distribution of aerosol droplets in postulated releases. These correlations, however, are based on results obtained from small engineered nozzles using Newtonian liquids that do not contain slurry particles and thus do not represent the fluids and breaches in the WTP. A test program was developed to measure the generation rate, and the release fraction which is the ratio of generation rate to spray flow rate, of droplets suspended in a test chamber and droplet size distribution from prototypic sprays. A novel test method was developed to allow measurement of sprays from small to large breaches and also includes the effect of aerosol generation from splatter when the spray impacts on walls. Results show that the release fraction decreases with increasing orifice area, though with a weaker dependence on orifice area than the currently-used correlation. A comparison of water sprays to slurry sprays with 8 to 20 wt% gibbsite or boehmite particles shows that the presence of slurry particles depresses the release fraction compared to water for droplets above 10 μm and increases the release fraction below this droplet size. (authors)

Spray rolling aluminum alloy strip

Energy Technology Data Exchange (ETDEWEB)

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

2004-10-10

Spray rolling combines spray forming with twin-roll casting to process metal flat products. It consists of atomizing molten metal with a high velocity inert gas, cooling the resultant droplets in flight and directing the spray between mill rolls. In-flight convection heat transfer from atomized droplets teams with conductive cooling at the rolls to rapidly remove the alloy's latent heat. Hot deformation of the semi-solid material in the rolls results in fully consolidated, rapidly solidified product. While similar in some ways to twin-roll casting, spray rolling has the advantage of being able to process alloys with broad freezing ranges at high production rates. This paper describes the process and summarizes microstructure and tensile properties of spray-rolled 2124 and 7050 aluminum alloy strips. A Lagrangian/Eulerian poly-dispersed spray flight and deposition model is described that provides some insight into the development of the spray rolling process. This spray model follows droplets during flight toward the rolls, through impact and spreading, and includes oxide film formation and breakup when relevant.

A universal salt model based on under-ground precipitation of solid salts due to supercritical water `out-salting'

Science.gov (United States)

Rueslåtten, H.; Hovland, M. T.

2010-12-01

shallow magma-chamber causes a sufficiently high heat-flow to drive a convection cell of seawater. The model shows that salt precipitates along the flow lines within the supercritical region (Hovland et al., 2006). During the various stages of planet Mars’ development, it must be inferred that zones with very high heat-flow also existed there. This meant that water (brine) confined in the crust of Mars was mobilized in a convective manner and would pass into the supercritical water zone during the down-going leg (the recharge leg) of the convective cell. The zones with supercritical out-salting would require accommodation space for large masses of solid salt, as modeled in the Red Sea analogy. However, as the accommodation space for the solid salt fills up, it will pile up and force its way upwards to form large, perhaps layered anticlines, as seen in the Hebes Mensa area of Mars and at numerous locations on Earth, including the Red Sea. Thus, we offer a universal ‘hydrothermal salt model’, which would be viable on all planets with free water in their interiors or on their surfaces, including Mars and Earth. Hovland, et al., 2006. Salt formation by supercritical seawater and submerged boiling. Marine and Petrol. Geol. 23, 855-69

Design Optimization of Liquid Fueled High Velocity Oxy- Fuel Thermal Spraying Technique for Durable Coating for Fossil Power Systems

Energy Technology Data Exchange (ETDEWEB)

Choudhuri, Ahsan [Univ. of Texas, El Paso, TX (United States); Love, Norman [Univ. of Texas, El Paso, TX (United States)

2016-11-04

systems, there exists a lack of fundamental understanding of the effect of hardware characteristics and operating parameters on HVOF thermally sprayed coatings. Motivated by these issues, this study is devoted to investigate the effect of hardware characteristics (e.g. spraying distance) and operating parameters (e.g. combustion chamber pressure, equivalence ratio, and total gas flow rate) on HVOF sprayed coatings using Inconel 718 alloy. The current study provides extensive understanding of several key operating and process parameters to optimize the next generation of HVOF thermally sprayed coatings for high temperature and harsh environment applications. A facility was developed to support this endeavor in a safe and efficient way, including a HVOF thermal spray system with a Data Acquisition and Remote Controls system (DARCS). The coatings microstructure and morphology were examined using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Nanoindentation.

Remotely controlled spray gun

Science.gov (United States)

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.

Molecular and physiological responses of sunflower (helianthus annuus l.) to pgpr and sa under salt stress

International Nuclear Information System (INIS)

Naz, R.

2015-01-01

This paper presents the efficacy of PGPR (Azospirillum and Pseudomonas) and its modulation by salicylic acid. Two hybrids of sunflower (Hysun and Parsun) were inoculated with Azospirillum spp. and Pseudomonas spp. prior to sowing. Salt stress (20 dSm-1) was applied 28 d after sowing followed by foliar spray of salicylic acid (100 micro M) after 4 h of salt treatment. Azospirillum and Pseudomonas inoculation alone and in combination with salicylic acid alleviated the effects of salt stress on both the sunflower hybrids. The salt tolerance in these treatments was mediated by an increase in relative water content, carotenoids, proline, ABA, induction of new polypeptide bands and yield of sunflower hybrids. In response to salt stress four new polypeptide bands were synthesized in both Hysun, whereas, a group of six polypeptide bands were observed in Parsun. Application of salicylic acid alone and in combination with Azospirillum found to induce four new polypeptide bands in Hysun and Parsun. It is inferred that synthesis of new proteins in response to the combined application of salicylic acid and Azospirillum under salt stress, may play an important role as stress proteins in tolerance of sunflower hybrids to salt stress. (author)

Narrow band flame emission from dieseline and diesel spray combustion in a constant volume combustion chamber

KAUST Repository

Wu, Zengyang

2016-08-18

In this paper, spray combustion of diesel (No. 2) and diesel-gasoline blend (dieseline: 80% diesel and 20% gasoline by volume) were investigated in an optically accessible constant volume combustion chamber. Effects of ambient conditions on flame emissions were studied. Ambient oxygen concentration was varied from 12% to 21% and three ambient temperatures were selected: 800 K, 1000 K and 1200 K. An intensified CCD camera coupled with bandpass filters was employed to capture the quasi-steady state flame emissions at 430 nm and 470 nm bands. Under non-sooting conditions, the narrow-band flame emissions at 430 nm and 470 nm can be used as indicators of CH∗ (methylidyne) and HCHO∗ (formaldehyde), respectively. The lift-off length was measured by imaging the OH∗ chemiluminescence at 310 nm. Flame emission structure and intensity distribution were compared between dieseline and diesel at wavelength bands. Flame emission images show that both narrow band emissions become shorter, thinner and stronger with higher oxygen concentration and higher ambient temperature for both fuels. Areas of weak intensity are observed at the flame periphery and the upstream for both fuels under all ambient conditions. Average flame emission intensity and area were calculated for 430 nm and 470 nm narrow-band emissions. At a lower ambient temperature the average intensity increases with increasing ambient oxygen concentration. However, at the 1200 K ambient temperature condition, the average intensity is not increasing monotonically for both fuels. For most of the conditions, diesel has a stronger average flame emission intensity than dieseline for the 430 nm band, and similar phenomena can be observed for the 470 nm band with 800 K and 1200 K ambient temperatures. However, for the 1000 K ambient temperature cases, dieseline has stronger average flame emission intensities than diesel for all oxygen concentrations at 470 nm band. Flame emissions for the two bands have a

Investigations on the self-excited oscillations in a kerosene spray flame

Energy Technology Data Exchange (ETDEWEB)

de la Cruz Garcia, M.; Mastorakos, E.; Dowling, A.P. [Engineering Department, Cambridge University, Trumpington Street, CB2 1PZ, Cambridge (United Kingdom)

2009-02-15

A laboratory scale gas turbine type burner at atmospheric pressure and with air preheat was operated with aviation kerosene Jet-A1 injected from a pressure atomiser. Self-excited oscillations were observed and analysed to understand better the relationship between the spray and thermo-acoustic oscillations. The fluctuations of CH{sup *} chemiluminescence measured simultaneously with the pressure were used to determine the flame transfer function. The Mie scattering technique was used to record spray fluctuations in reacting conditions with a high speed camera. Integrating the Mie intensity over the imaged region gave a temporal signal acquired simultaneously with pressure fluctuations and the transfer function between the light scattered from the spray and the velocity fluctuations in the plenum was evaluated. Phase Doppler anemometry was used for axial velocity and drop size measurements at different positions downstream the injection plane and for various operating conditions. Pressure spectra showed peaks at a frequency that changed with air mass flow rate. The peak for low air mass flow rate operation was at 220 Hz and was associated with a resonance of the supply plenum. At the same global equivalence ratio but at high air mass flow rates, the pressure spectrum peak was at 323 Hz, a combustion chamber resonant frequency. At low air flow rates, the spray fluctuation motion was pronounced and followed the frequency of the pressure oscillation. At high air flow rates, more effective evaporation resulted in a complete disappearance of droplets at an axial distance of about 1/3 burner diameters from the injection plane, leading to a different flame transfer function and frequency of the self-excited oscillation. The results highlight the sensitivity of the self-excited oscillation to the degree of mixing achieved before the main recirculation zone. (author)

Comparision on dynamic behavior of diesel spray and rapeseed oil spray in diesel engine

Science.gov (United States)

Sapit, Azwan; Azahari Razali, Mohd; Faisal Hushim, Mohd; Jaat, Norrizam; Nizam Mohammad, Akmal; Khalid, Amir

2017-04-01

Fuel-air mixing is important process in diesel combustion. It significantly affects the combustion and emission of diesel engine. Biomass fuel has high viscosity and high distillation temperature and may negatively affect the fuel-air mixing process. Thus, study on the spray development and atomization of this type of fuel is important. This study investigates the atomization characteristics and droplet dynamic behaviors of diesel engine spray fuelled by rapeseed oil (RO) and comparison to diesel fuel (GO). Optical observation of RO spray was carried out using shadowgraph photography technique. Single nano-spark photography technique was used to study the characteristics of the spray while dual nano-spark shadowgraph technique was used to study the spray droplet behavior. Using in-house image processing algorithm, the images were processed and the boundary condition of each spray was also studied. The results show that RO has very poor atomization due to the high viscosity nature of the fuel when compared to GO. This is in agreement with the results from spray droplet dynamic behavior studies that shows due to the high viscosity, the RO spray droplets are large in size and travel downward, with very little influence of entrainment effect due to its large kinematic energy.

Effect of foliar application of α-tocopherol on vegetative growth and some biochemical constituents of two soybean genotypes under salt stress

Science.gov (United States)

Rahmawati, N.; Damanik, R. I. M.

2018-02-01

Foliar spray of plant growth regulating compounds including antioxidants is an effective strategy to overcome the adverse effects of environmental constraints on different plants. A field experiment was conducted on May - July 2017 at the experimental farm in Paluh Merbau Village Deli Serdang (EC 6 - 7 dS/m). The aim was to study the effects of foliar spray of α-tocopherol (0, 250, 500, 500 ppm) on vegetative growth and some chemical constituents of 2 soybean genotypes (Grobogan x Grobogan and Grobogan x Anjasmoro) under salt stress (EC 6 - 7 dS/m). Most of morphological and biochemical parameters were significantly affected by application of α-tocopherol. The α-tocopherol at 500 ppm recorded the best value of root fresh weight, shoot and root dry weight, number of leaves, chlorophyll b, and soluble protein content. There was significant difference found between plants treated with α-tocopherol in terms of number of branch, shoot fresh weight, and chlorophyll a. Soybean genotypes showed diverse morphology and physiological responses to salt stress. Grobogan x Anjasmoro genotype was salt-sensitive based on all variable, while Grobogan x Grobogan genotype was more tolerant based on morphological and biochemical characters.

Evaluation of Paclobutrazol Spraying on Salinity Hardiness of Peach- Almond Hybrid (GF677 Rootstock

Directory of Open Access Journals (Sweden)

azam amiri

2017-02-01

Full Text Available Introduction: Salinity is a common abiotic stress that seriously affects crop production in some parts of the world, particularly in arid and semi-arid regions. The deleterious effects of salinity on plant growth are associated with low osmotic potential of soil solution (water stress, nutritional imbalance, specific ion effect (salt stress, or a combination of these factors. Paclobutrazol (PBZ, a member of the triazole plant growth inhibitor group, is a broad-spectrum gibberellin biosynthesis inhibitor. Triazoles have both fungal toxicity and plant growth regulatory effects. They also increase tolerance of various plant species to biotic and abiotic stresses, including fungal pathogens, drought, air pollutants, and low- and high-temperature stress. According to our knowledge, there are no reports on the effects of exogenous PBZ enhancing vegetative peach- almond hybrid (GF 677 rootstock tolerance to salt stress. Therefore, the objective of this work was the possibility test of this idea that PBZ application would protect GF 677 rootstock from damaging effects of salinity. Materials and Methods: One-year-old rooted cuttings of GF 677 were grown in in plastic pots in the research greenhouse of Agricultural College, Isfahan University of Technology of Iran. The minimum and maximum temperatures during the experiment period were 19 and 32˚C, respectively. After cutting establishment (3 months, the plants were sprayed twice (with a 7 days interval with 0 (control, 20 and 40 mg l-1 PBZ to the point of run-off. One week after the second foliar application of PBZ, each plants was subjected to one of several salt stress treatments. The salt treatments (0, 25 and 50 mM NaCl were applied to the pots intervals in 0.5 l of irrigation water. To avoid osmotic shock, the NaCl concentration was increased gradually. The layout was a 3×3 factorial experiment in a completely randomized design, with four replications. The experimental measurements were carried out

Thermal spray for commercial shipbuilding

Science.gov (United States)

Rogers, F. S.

1997-09-01

Thermal spraying of steel with aluminum to protect it from corrosion is a technology that has been proven to work in the marine environment. The thermal spray coating system includes a paint sealer that is applied over the thermally sprayed aluminum. This extends the service life of the coating and provides color to the end product. The thermal spray system protects steel both through the principle of isolation (as in painting) and galvanizing. With this dual protection mechanism, steel is protected from corrosion even when the coating is damaged. The thermal- sprayed aluminum coating system has proved the most cost- effective corrosion protection system for the marine environment. Until recently, however, the initial cost of application has limited its use for general application. Arc spray technology has reduced the application cost of thermal spraying of aluminum to below that of painting. Commercial shipbuilders could use this technology to enhance their market position in the marine industry.

Influence of geometric and hydro-dynamic parameters of injector on calculation of spray characteristics of diesel engines

Directory of Open Access Journals (Sweden)

Filipović Ivan

2011-01-01

Full Text Available The main role in air/fuel mixture formation at the IC diesel engines has the energy introduced by fuel into the IC engine that is the characteristics of spraying fuel into the combustion chamber. The characteristic can be defined by the spray length, the spray cone angle, the physical and the chemical structure of fuel spray by different sections. Having in mind very complex experimental setups for researching in this field, the mentioned characteristics are mostly analyzed by calculations. There are two methods in the literature, the first based on use of the semi-empirical expressions (correlations and the second, the calculations of spray characteristics by use of very complex mathematical methods. The second method is dominant in the modern literature. The main disadvantage of the calculation methods is a correct definition of real state at the end of the nozzle orifice (real boundary conditions. The majority of the researchers in this field use most frequently the coefficient of total losses inside the injector. This coefficient depends on injector design, as well as depends on the level of fuel energy and fuel energy transformation along the injector. Having in mind the importance of the real boundary conditions, the complex methods for calculation of the fuel spray characteristics should have the calculation of fuel flows inside the injector and the calculation of spray characteristics together. This approach is a very complex numerical problem and there are no existing computer programs with satisfactory calculation results. Analysis of spray characteristics by use of the semi-empirical expressions (correlations is presented in this paper. The special attention is dedicated to the analysis of the constant in the semi-empirical expressions and influence parameters on this constant. Also, the method for definition of realistic boundary condition at the end of the nozzle orifice is presented in the paper. By use of this method completely

Energy considerations in spraying process of a spill-return pressure-swirl atomizer

International Nuclear Information System (INIS)

Jedelsky, Jan; Jicha, Miroslav

2014-01-01

Graphical abstract: - Highlights: • We analyse energy conversion in simplex and spill-return pressure-swirl atomizer. • Inlet (pressure) energy converts into liquid motion with nozzle efficiency ∼58%. • Kinetic energy of developed spray at closed spill line is ∼33% of the inlet energy. • It consists of energy of droplets (∼2/3) and entrained air (1/3). • Atomization efficiency is <0.3%; it declines with inlet pressure and spill opening. - Abstract: The work focuses on energy conversion during the internal flow, discharge and formation of the spray from a pressure-swirl (PS) atomizer in the simplex as well as spill-return mode. Individual energy forms are described in general and assessed experimentally for a particular PS atomizer and light heating oil as a medium. The PS spray was observed at various loads to investigate the liquid breakup process and the spray characteristics. Spatially resolved diameters and droplet velocities, measured by means of phase-Doppler anemometry, served for estimation of the energy characteristics in the PS spray. The input energy given by the potential energy of the supplied liquid partially converts into the kinetic energy (KE) in the swirling ports with hydraulic loss in per cent scale. Most of the pressure drop is associated with rotational motion in the swirl chamber with total conversion efficiency at the exit orifice ∼58%. The rest of the input energy ends up as friction loss, leaving room for improvement. The overall value (ID 32 ) of the Sauter mean diameter of droplets in the spray, D 32 , varies with pressure drop Δp l powered to −0.1. The radial profiles of D 32 widen with the increase in spill/feed ratio (SFR), but the ID 32 remain almost constant within the studied SFR range. The spray KE at closed spill line covers the droplet KE (21–26%) and that of entrained air (10–13%), both moderately varying with Δp l . The specific KEs of both the liquid and air markedly drop down with the spill line

Electrostatically atomised hydrocarbon sprays

Energy Technology Data Exchange (ETDEWEB)

Yule, A.J.; Shrimpton, J.S.; Watkins, A.P.; Balachandran, W.; Hu, D. [UMIST, Manchester (United Kingdom). Thermofluids Division, Dept. of Mechanical Engineering

1995-07-01

A burner using an electrostatic method to produce and control a fuel spray is investigated for non-burning sprays. The burner has a charge injection nozzle and the liquid flow rate and charge injection rate are varied using hydrocarbon liquids of differing viscosities, surface tensions and electrical conductivities (kerosene, white spirit and diesel oil). Droplet size distributions are measured and it is shown how the dropsize, spray pattern, breakup mechanism and breakup length depend on the above variables, and in particular on the specific charge achieved in the spray. The data are valuable for validating two computer models under development. One predicts the electric field and flow field inside the nozzle as a function of emitter potential, geometry and flow rate. The other predicts the effect of charge on spray dispersion, with a view to optimizing spray combustion. It is shown that electrostatic disruptive forces can be used to atomize oils at flow rates commensurate with practical combustion systems and that the charge injection technique is particularly suitable for highly resistive liquids. Possible limitations requiring further research include the need to control the wide spray angle, which may provide fuel-air mixtures too lean near the nozzle, and the need to design for maximum charge injection rate, which is thought to be limited by corona breakdown in the gas near the nozzle orifice. 30 refs., 15 figs., 1 tab.

Influence of spray parameters on the microstructure and mechanical properties of gas-tunnel plasma sprayed hydroxyapatite coatings

International Nuclear Information System (INIS)

Morks, M.F.; Kobayashi, Akira

2007-01-01

For biomedical applications, hydroxyapatite (HA) coatings were deposited on 304 stainless steel substrate by using a gas tunnel type plasma spraying process. The influences of spraying distances and plasma arc currents on the microstructure, hardness and adhesion properties of HA coatings were investigated. Microstructure observation by SEM showed that HA coatings sprayed at low plasma power have a porous structure and poor hardness. HA coatings sprayed at high plasma power and short spraying distance are characterized by good adhesion and low porosity with dense structure. Hardness increased for HA coatings sprayed at shorter spraying distance and higher plasma power, mainly due to the formation of dense coatings

Particle size distribution of aerosols sprayed from household hand-pump sprays containing fluorine-based and silicone-based compounds.

Science.gov (United States)

Kawakami, Tsuyoshi; Isama, Kazuo; Ikarashi, Yoshiaki

2015-01-01

Japan has published safety guideline on waterproof aerosol sprays. Furthermore, the Aerosol Industry Association of Japan has adopted voluntary regulations on waterproof aerosol sprays. Aerosol particles of diameter less than 10 µm are considered as "fine particles". In order to avoid acute lung injury, this size fraction should account for less than 0.6% of the sprayed aerosol particles. In contrast, the particle size distribution of aerosols released by hand-pump sprays containing fluorine-based or silicone-based compounds have not been investigated in Japan. Thus, the present study investigated the aerosol particle size distribution of 16 household hand-pump sprays. In 4 samples, the ratio of fine particles in aerosols exceeded 0.6%. This study confirmed that several hand-pump sprays available in the Japanese market can spray fine particles. Since the hand-pump sprays use water as a solvent and their ingredients may be more hydrophilic than those of aerosol sprays, the concepts related to the safety of aerosol-sprays do not apply to the hand pump sprays. Therefore, it may be required for the hand-pump spray to develop a suitable method for evaluating the toxicity and to establish the safety guideline.

Parameter Studies on High-Velocity Oxy-Fuel Spraying of CoNiCrAlY Coatings Used in the Aeronautical Industry

Directory of Open Access Journals (Sweden)

J. A. Cabral-Miramontes

2014-01-01

Full Text Available The thermal spraying process is a surface treatment which does not adversely affect the base metal on which it is performed. The coatings obtained by HVOF thermal spray are employed in aeronautics, aerospace, and power generation industries. Alloys and coatings designed to resist oxidizing environments at high temperatures should be able to develop a surface oxide layer, which is thermodynamically stable, slowly growing, and adherent. MCrAlY type (M = Co, Ni or combination of both coatings are used in wear and corrosion applications but also provide protection against high temperature oxidation and corrosion attack in molten salts. In this investigation, CoNiCrAlY coatings were produced employing a HVOF DJH 2700 gun. The work presented here focuses on the influences of process parameters of a gas-drive HVOF system on the microstructure, adherence, wear, and oxygen content of CoNiCrAlY. The results showed that spray distance significantly affects the properties of CoNiCrAlY coatings.

Stimulation of Intestinal Cl- Secretion Through CFTR by Caffeine Intake in Salt-Sensitive Hypertensive Rats

Directory of Open Access Journals (Sweden)

Xiao Wei

2018-03-01

Full Text Available Background/Aims: High salt consumption is a major risk factor for hypertension, and sodium homeostasis is regulated by both intestinal sodium absorption and urinary sodium excretion. Chronic caffeine intake has been reported to attenuate salt-sensitive hypertension by promoting urinary sodium excretion; however, its exact role in intestinal sodium absorption remains unknown. Here, we investigated whether and how chronic caffeine consumption antagonizes salt-sensitive hypertension by inhibiting intestinal sodium absorption. Methods: Dahl salt-sensitive rats were fed 8% NaCl chow and 0.1% caffeine in their drinking water for 15 days. The blood pressure and fecal sodium content were measured. The effect of caffeine on the movement of Cl- in enterocyte cells was determined with the Ussing chamber assay. Results: Rats that were treated with caffeine displayed significantly lower mean blood pressure and higher fecal sodium content than the controls. Consistent with these findings, caffeine intake decreased fluid absorption by the intestine in the fluid perfusion experiment. Further, the results from the Ussing chamber assay indicated that caffeine promoted Cl- secretion through enterocyte apical cystic fibrosis transmembrane conductance regulator (CFTR, and thus inhibited sodium absorption. Moreover, depletion of cAMP or inhibition of CFTR completely abolished the effect of caffeine on Cl- secretion. Conclusion: The results indicate that chronic caffeine consumption reduces sodium absorption by promoting CFTR-mediated Cl- secretion in the intestine, which contributes to the anti-hypertensive effect of caffeine in salt-sensitive rats.

Investigation of spray characteristics from a low-pressure common rail injector for use in a homogeneous charge compression ignition engine

Science.gov (United States)

Lee, Kihyung; Reitz, Rolf D.

2004-03-01

Homogeneous charge compression ignition (HCCI) combustion provides extremely low levels of pollutant emissions, and thus is an attractive alternative for future IC engines. In order to achieve a uniform mixture distribution within the engine cylinder, the characteristics of the fuel spray play an important role in the HCCI engine concept. It is well known that high-pressure common rail injection systems, mainly used in diesel engines, achieve poor mixture formation because of the possibility of direct fuel impingement on the combustion chamber surfaces. This paper describes spray characteristics of a low-pressure common rail injector which is intended for use in an HCCI engine. Optical diagnostics including laser diffraction and phase Doppler methods, and high-speed camera photography, were applied to measure the spray drop diameter and to investigate the spray development process. The drop sizing results of the laser diffraction method were compared with those of a phase Doppler particle analyser (PDPA) to validate the accuracy of the experiments. In addition, the effect of fuel properties on the spray characteristics was investigated using n-heptane, Stoddard solvent (gasoline surrogate) and diesel fuel because HCCI combustion is sensitive to the fuel composition. The results show that the injector forms a hollow-cone sheet spray rather than a liquid jet, and the atomization efficiency is high (small droplets are produced). The droplet SMD ranged from 15 to 30 µm. The spray break-up characteristics were found to depend on the fuel properties. The break-up time for n-heptane is shorter and the drop SMD is smaller than that of Stoddard solvent and diesel fuel.

A study on nozzle flow and spray characteristics of piezo injector for next generation high response injection

International Nuclear Information System (INIS)

Lee, Jin Wook; Min, Kyoung Doug

2006-01-01

Most diesel injector, which is currently used in high-pressure common rail fuel injection system of diesel engine, is driven by the solenoid coil energy for its needle movement. The main disadvantage of this solenoid-driven injector is a high power consumption, high power loss through solenoid coil and relatively fixed needle response's problem. In this study, a prototype piezo-driven injector, as a new injector mechanism driven by piezoelectric energy based on the concept of inverse piezo-electric effect, has been designed and fabricated to know the effect of piezo-driven injection processes on the diesel spray structure and internal nozzle flow. Firstly we investigated the spray characteristics in a constant volume chamber pressurized by nitrogen gas using the back diffusion light illumination method for high-speed temporal photography and also analyzed the inside nozzle flow by a fully transient simulation with cavitation model using VOF(Volume Of Fraction) method. The numerical calculation has been performed to simulate the cavitating flow of 3-dimensional real size single hole nozzle along the injection duration. Results were compared between a conventional solenoid-driven injector and piezo-driven injector, both equipped with the same micro-sac multi-hole injection nozzle. The experimental results show that the piezo-driven injector has short injection delay and a faster spray development and produces higher injection velocity than the solenoid-driven injector. And the predicted simulation results with the degree of cavitation's generation inside nozzle for faster needle response in a piezo-driven injector were reflected to spray development in agreement with the experimental spray images

An experimental methodology to quantify the spray cooling event at intermittent spray impact

International Nuclear Information System (INIS)

Moreira, Antonio L.N.; Carvalho, Joao; Panao, Miguel R.O.

2007-01-01

The present paper describes an experimental methodology devised to study spray cooling with multiple-intermittent sprays as those found in fuel injection systems of spark-ignition and diesel engines, or in dermatologic surgery applications. The spray characteristics and the surface thermal behaviour are measured by combining a two-component phase-Doppler anemometer with fast response surface thermocouples. The hardware allows simultaneous acquisition of Doppler and thermocouple signals which are processed in Matlab to estimate the time-varying heat flux and fluid-dynamic characteristics of the spray during impact. The time resolution of the acquisition system is limited by the data rate of validation of the phase-Doppler anemometer, but it has been shown to be accurate for the characterization of spray-cooling processes with short spurt durations for which the transient period of spray injection plays an important role. The measurements are processed in terms of the instantaneous heat fluxes, from which phase-average values of the boiling curves are obtained. Two of the characteristic parameters used in the thermal analysis of stationary spray cooling events, the critical heat flux (CHF) and Leidenfrost phenomenon, are then inferred in terms of operating conditions of the multiple-intermittent injections, such as the frequency, duration and pressure of injection. An integral method is suggested to describe the overall process of heat transfer, which accounts for the fluid-dynamic heterogeneities induced by multiple and successive droplet interactions within the area of spray impact. The method considers overall boiling curves dependant on the injection conditions and provides an empirical tool to characterize the heat transfer processes on the impact of multiple-intermittent sprays. The methodology is tested in a preliminary study of the effect of injection conditions on the heat removed by a fuel spray striking the back surface of the intake valve as in spark

The osmolyte xylitol reduces the salt concentration of airway surface liquid and may enhance bacterial killing

Science.gov (United States)

Zabner, Joseph; Seiler, Michael P.; Launspach, Janice L.; Karp, Philip H.; Kearney, William R.; Look, Dwight C.; Smith, Jeffrey J.; Welsh, Michael J.

2000-10-01

The thin layer of airway surface liquid (ASL) contains antimicrobial substances that kill the small numbers of bacteria that are constantly being deposited in the lungs. An increase in ASL salt concentration inhibits the activity of airway antimicrobial factors and may partially explain the pathogenesis of cystic fibrosis (CF). We tested the hypothesis that an osmolyte with a low transepithelial permeability may lower the ASL salt concentration, thereby enhancing innate immunity. We found that the five-carbon sugar xylitol has a low transepithelial permeability, is poorly metabolized by several bacteria, and can lower the ASL salt concentration in both CF and non-CF airway epithelia in vitro. Furthermore, in a double-blind, randomized, crossover study, xylitol sprayed for 4 days into each nostril of normal volunteers significantly decreased the number of nasal coagulase-negative Staphylococcus compared with saline control. Xylitol may be of value in decreasing ASL salt concentration and enhancing the innate antimicrobial defense at the airway surface.

Application of wear resistant spraying for diesel engine; Diesel kikan eno taimamo yosha no tekiyo

Energy Technology Data Exchange (ETDEWEB)

Kitajima, Y. [Mitsui Engineering and Shipbuliding Co. Ltd., Tokyo (Japan)

1999-03-31

Diesel engines used widely as propelling engines of ships have increasingly been provided with a high output and a high thermal efficiency; their structural members, particularly, the component parts for combustion chambers are therefore used under severe conditions, giving rise to the need of surface treatment and surface reforming of the members. Parts for marine diesel engines are huge, so that the technology applicable to the surface treatment and reforming are limited in point of facility and cost; therefore, most suitable is thermal spraying. This paper primarily discusses, among marine diesel engines, a 2-cycle low-speed engine with a 260-980mm bore used for the main engine of a merchant ship such as a container ship, bulk carrier or a tanker, and a 4-cycle medium-speed engine with a 300-420mm bore used for the main engine of a naval vessel; the paper explains the application status of a thermal spraying technology which is in progress to cope with the high output and high thermal efficiency of the diesel engines, explaining particularly the story of the development and the technological features of the wear resistant thermal spraying, which has been put to practical use, on the cylinder liner and the piston ring of the 4-cycle medium-speed engine. (NEDO)

Substrate system for spray forming

Energy Technology Data Exchange (ETDEWEB)

Chu, Men G. (Export, PA); Chernicoff, William P. (Harrisburg, PA)

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.

Characterization of Sodium Spray Aerosols

Energy Technology Data Exchange (ETDEWEB)

Nelson, C. T.; Koontz, R. L.; Silberberg, M. [Atomics International, North American Rockwell Corporation, Canoga Park, CA (United States)

1968-12-15

The consequences of pool and spray fires require evaluation in the safety analysis of liquid metal-cooled fast breeder reactors. Sodium spray fires are characterized by high temperature and pressure, produced during the rapid combustion of sodium in air. Following the initial energy release, some fraction of the reaction products are available as aerosols which follow the normal laws of agglomeration, growth, settling, and plating. An experimental study is underway at Atomics International to study the characteristics of high concentration sprays of liquid sodium in reduced oxygen atmospheres and in air. The experiments are conducted in a 31.5 ft{sup 3} (2 ft diam. by 10 ft high) vessel, certified for a pressure of 100 lb/in{sup 2} (gauge). The spray injection apparatus consists of a heated sodium supply pot and a spray nozzle through which liquid sodium is driven by nitrogen pressure. Spray rate and droplet size can be varied by the injection velocity (nozzle size, nitrogen pressure, and sodium temperature). Aerosols produced in 0, 4, and 10 vol. % oxygen environments have been studied. The concentration and particle size distribution of the material remaining in the air after the spray injection and reaction period are measured. Fallout rates are found to be proportional to the concentration of aerosol which remains airborne following the spray period. (author)

A spray flamelet/progress variable approach combined with a transported joint PDF model for turbulent spray flames

Science.gov (United States)

Hu, Yong; Olguin, Hernan; Gutheil, Eva

2017-05-01

A spray flamelet/progress variable approach is developed for use in spray combustion with partly pre-vaporised liquid fuel, where a laminar spray flamelet library accounts for evaporation within the laminar flame structures. For this purpose, the standard spray flamelet formulation for pure evaporating liquid fuel and oxidiser is extended by a chemical reaction progress variable in both the turbulent spray flame model and the laminar spray flame structures, in order to account for the effect of pre-vaporised liquid fuel for instance through use of a pilot flame. This new approach is combined with a transported joint probability density function (PDF) method for the simulation of a turbulent piloted ethanol/air spray flame, and the extension requires the formulation of a joint three-variate PDF depending on the gas phase mixture fraction, the chemical reaction progress variable, and gas enthalpy. The molecular mixing is modelled with the extended interaction-by-exchange-with-the-mean (IEM) model, where source terms account for spray evaporation and heat exchange due to evaporation as well as the chemical reaction rate for the chemical reaction progress variable. This is the first formulation using a spray flamelet model considering both evaporation and partly pre-vaporised liquid fuel within the laminar spray flamelets. Results with this new formulation show good agreement with the experimental data provided by A.R. Masri, Sydney, Australia. The analysis of the Lagrangian statistics of the gas temperature and the OH mass fraction indicates that partially premixed combustion prevails near the nozzle exit of the spray, whereas further downstream, the non-premixed flame is promoted towards the inner rich-side of the spray jet since the pilot flame heats up the premixed inner spray zone. In summary, the simulation with the new formulation considering the reaction progress variable shows good performance, greatly improving the standard formulation, and it provides new

Overlayer structure of subphthalocyanine derivative deposited on Au (111) surface by a spray-jet technique

International Nuclear Information System (INIS)

Suzuki, Hitoshi; Yamada, Toshiki; Miki, Hideki; Mashiko, Shinro

2006-01-01

A new spray-jet technique was used to deposit subphthalocyanine derivative (chloro[tri-tert-butyl subphthalocyaninato]boron (TBSubPc)) on Au (111) surface in an ultra-high vacuum (UHV) chamber. The deposited molecular overlayer was observed with UHV scanning tunneling microscopy (STM) at 77 K. The STM images showed that TBSubPc molecules formed a stripe pattern with regular spacing, indicating that they preferentially adsorbed along the herringbone structure of the Au (111) surface. This behavior was very similar to that of TBSubPc molecules deposited by thermal evaporation

Improving the performance of fluorine-doped tin oxide by adding salt

Energy Technology Data Exchange (ETDEWEB)

Purwanto, Agus, E-mail: Aguspur@uns.ac.id [Department of Chemical Engineering, Faculty of Engineering, Sebelas Maret University, Jl. Ir. Sutami 36 A, Surakarta, Central Java 57126 (Indonesia); Widiyandari, Hendri [Department of Physics, Faculty of Sciences and Mathematics, Diponegoro University, Jl. Prof. Dr. Soedarto, Tembalang, Semarang 50275 (Indonesia); Suryana, Risa [Department of Physics, Faculty of Mathematics and Natural Sciences, Sebelas Maret University, Jl. Ir. Sutami 36 A, Surakarta, Central Java 57126 (Indonesia); Jumari, Arif [Department of Chemical Engineering, Faculty of Engineering, Sebelas Maret University, Jl. Ir. Sutami 36 A, Surakarta, Central Java 57126 (Indonesia)

2015-07-01

High-performance fluorine-doped tin oxide (FTO) films were fabricated via a spray deposition technique with salt added to the precursor. The addition of NaCl in the precursor improved the conductivity of the FTO films. Increasing the NaCl concentration to its optimal concentration reduced the sheet resistance of the FTO film. The optimal values for the addition of a NaCl were 0.5, 0.5, 1.5, and 1.5 at.% for the FTO film prepared using NH{sub 4}F concentration of 4, 10, 16, and 22 at.%, respectively. The lowest sheet resistance of the salt-added FTO film was 4.8 Ω/□. The FTO film averaged a transmittance of more than 80% in the visible range region (λ = 400–800 nm). XRD diffractograms confirmed that the crystal structure of the as-grown FTO film was that of a tetragonal SnO{sub 2} and that the addition of salt improved its crystallinity. This film has the potential for use as an electrode for dye-sensitized solar cells (DSSCs). - Highlights: • A method to improve FTO performance using the addition of salt • The FTO film exhibited high performance of conductivity and light transmittance. • This technique is low-cost, fast and scales-up easily using simple devices.

Effect of the parameters of a straight-through pulverized coal spray on formation of nitrogen oxides

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R.

1987-04-01

Experiments were conducted on varying the parameters affecting intensity of the mixing process at the starting point of a pulverized coal spray. Investigations were carried out using Donetsk black coal in a BKZ-210-140FZhSh steam generator equipped with a tangential combustion chamber. The plant featured liquid slag removal and direct blow-in as well as a medium-speed model VSM-140 mill. Four experiments were conducted in which gas samples were taken from the combustion chamber and analyzed for RO/sub 2/ and O/sub 2/ as well as CO and H/sub 2/. A relationship between reducing gases at the starting point of the torch and the initial air feed factor was demonstrated. Experiments were conducted to determine a relationship between NO/sub x/ concentrations in exhaust gases and the initial air feed factor. 5 refs.

Dynamics of flare sprays

International Nuclear Information System (INIS)

Tandberg-Hanssen, E.; Hansen, R.T.

1980-01-01

During solar cycle No. 20 new insight into the flare-spray phenomenon has been attained due to several innovations in solar optical-observing techniques (higher spatial resolution cinema-photography, tunable pass-band filters, multi-slit spectroscopy and extended angular field coronographs). From combined analysis of 13 well-observed sprays which occured between 1969-1974 we conclude that (i) the spray material originates from a preexisting active region filament which undergoes increased absorption some tens of minutes prior to the abrupt chromospheric brightening at the 'flare-start', and (ii) the spray material is confined within a steadily expanding, loop-shaped (presumably magnetically controlled) envelope with part of the material draining back down along one or both legs of the loop. (orig.)

Scalable organic solvent free supercritical fluid spray drying process for producing dry protein formulations.

Science.gov (United States)

Nuchuchua, O; Every, H A; Hofland, G W; Jiskoot, W

2014-11-01

In this study, we evaluated the influence of supercritical carbon dioxide (scCO2) spray drying conditions, in the absence of organic solvent, on the ability to produce dry protein/trehalose formulations at 1:10 and 1:4 (w/w) ratios. When using a 4L drying vessel, we found that decreasing the solution flow rate and solution volume, or increasing the scCO2 flow rate resulted in a significant reduction in the residual water content in dried products (Karl Fischer titration). The best conditions were then used to evaluate the ability to scale the scCO2 spray drying process from 4L to 10L chamber. The ratio of scCO2 and solution flow rate was kept constant. The products on both scales exhibited similar residual moisture contents, particle morphologies (SEM), and glass transition temperatures (DSC). After reconstitution, the lysozyme activity (enzymatic assay) and structure (circular dichroism, HP-SEC) were fully preserved, but the sub-visible particle content was slightly increased (flow imaging microscopy, nanoparticle tracking analysis). Furthermore, the drying condition was applicable to other proteins resulting in products of similar quality as the lysozyme formulations. In conclusion, we established scCO2 spray drying processing conditions for protein formulations without an organic solvent that holds promise for the industrial production of dry protein formulations. Copyright © 2014 Elsevier B.V. All rights reserved.

UV and VUV characteristics of (YGd)2O3:Eu phosphor particles prepared by spray pyrolysis from polymeric precursors

International Nuclear Information System (INIS)

Kim, E.J.; Kang, Y.C.; Park, H.D.; Ryu, S.K.

2003-01-01

Red-emitting (YGd) 2 O 3 :Eu phosphor particles, with high luminescence efficiency under vacuum ultraviolet (VUV) and ultraviolet (UV) excitation, were prepared by a large-scale spray pyrolysis process. To control the morphology of phosphor particles under severe preparation conditions, spray solution with polymeric precursors were introduced in spray pyrolysis. The prepared (YGd) 2 O 3 :Eu phosphor particles had spherical shape and filled morphology even after post-treatment irrespective of Gd/Y ratio. In the case of solution with polymeric precursors, long polymeric chains formed by esterification reaction in a hot tubular reactor; the droplets turned into viscous gel, which retarded the precipitation of nitrate salts and promoted the volume precipitation of droplets. The brightness of (YGd) 2 O 3 :Eu phosphor particles increased with increasing gadolinium content, and the Gd 2 O 3 :Eu phosphor had the highest luminescence intensity under UV and VUV excitation. The maximum peak intensity of Gd 2 O 3 :Eu phosphor particles under UV and VUV were 118 and 110% of the commercial Y 2 O 3 :Eu phosphor particles, respectively

One-step spray-coating process for the fabrication of colorful superhydrophobic coatings with excellent corrosion resistance.

Science.gov (United States)

Li, Jian; Wu, Runni; Jing, Zhijiao; Yan, Long; Zha, Fei; Lei, Ziqiang

2015-10-06

A simple method was used to generate colorful hydrophobic stearate particles via chemical reactions between inorganic salts and sodium stearate. Colored self-cleaning superhydrophobic coatings were prepared through a facile one-step spray-coating process by spraying the stearate particle suspensions onto stainless steel substrates. Furthermore, the colorful superhydrophobic coating maintains excellent chemical stability under both harsh acidic and alkaline circumstances. After being immersed in a 3.5 wt % NaCl aqueous solution for 1 month, the as-prepared coatings remained superhydrophobic; however, they lost their self-cleaning property with a sliding angle of about 46 ± 3°. The corrosion behavior of the superhydrophobic coatings on the Al substrate was characterized by the polarization curve and electrochemical impedance spectroscopy (EIS). The electrochemical corrosion test results indicated that the superhydrophobic coatings possessed excellent corrosion resistance, which could supply efficient and long-term preservation for the bare Al substrate.

Corrosion prevention of the rail by thermal spray coating of Zn-Al alloy; Zn-Al gokin yosha hifuku ni yoru reru no boshoku

Energy Technology Data Exchange (ETDEWEB)

Mizoguchi, S. [Nippon Steel Corp., Kitakyushu (Japan)] Urashima, C. [Kyushu Techno Research Corp., Fukuoka (Japan); Itai, K. [Nippon Steel Corp., Kitakyushu, Fukuoka (Japan). Technical Research Inst. of Yawata Works; Ichiriki, T.; Nishiki, M. [Kyushu Rail way comdany, Fukuoka (Japan)

1997-03-30

Replacement of the rail in under-sea tunnel such as the Kammon Tunnel is carried out very five years because of the severe corrosion caused by the humid state due to the leakage of sea water or the mist of sea water swept up by the passing trains. In this study, salt water spraying or sea water spraying test is carried out using Zn-Al alloy with the corrosion resistance and thermal spray efficiency even higher than those of Zn or Al. A rail coated by thermal spray of Zn-15mass%Al alloy has been laid by trial in the practical rail road of Kammon Tunnel for 5 years and 3 months, the deterioration degree of the coating, pitting depth, actual fatigue strength, etc. are evaluated. Further, these factors of a rail re-coated by Zincrich Primer+Tar Epoxy and a bare rail laid at the same time are evaluated for comparison. It is presumed by the results of the examination about the service life of a rail coated by the thermal spray of Zn-Al alloy based on the pitting depth in the rail base that the service life of such coated rail is more than twice as that of the bare rails used currently. 5 refs., 14 figs., 3 tabs.

Polyurethane spray coating of aluminum wire bonds to prevent corrosion and suppress resonant oscillations

CERN Document Server

Izen, Joseph; The ATLAS collaboration; Kurth, Matthew Glenn

2015-01-01

Unencapsulated aluminum wedge wire bonds are common in particle-physics pixel and strip detectors. Industry-favored bulk encapsulation is eschewed due to the range of operating temperatures and radiation. Wire bond failures are a persistent, source of tracking detector failure Unencapsulated bonds are vulnerable to condensation-induced corrosion, particularly when halides are present. Oscillations from periodic Lorenz forces are documented as another source of wire bond failure. Spray application of polyurethane coatings, performance of polyurethane-coated wire bonds after climate chamber exposure, and resonant properties of PU-coated wire bonds and their resistance to periodic Lorenz forces will be described.

Development of spraying methods for high density bentonite barriers. Part 3. Field investigation of spraying methods

International Nuclear Information System (INIS)

Tanaka, Toshiyuki; Nakajima, Makoto; Kobayashi, Ichizo; Toida, Masaru; Fukuda, Katsumi; Sato, Tatsuro; Nonaka, Katsumi; Gozu, Keisuke

2007-01-01

The authors have developed a new method of constructing high density bentonite barriers by means of a wet spraying method. Using this method, backfill material can be placed in narrow upper and side parts in a low-level radioactive waste disposal facility. Using a new supplying machine for bentonite, spraying tests were conducted to investigate the conditions during construction. On the basis of the test results, the various parameters for the spraying method were investigated. The test results are summarized as follows: 1. The new machine supplied about twice the weight of material supplied by a screw conveyor. A dry density of spraying bentonite 0.05 Mg/m 3 higher than that of a screw conveyor with the same water content could be achieved. 2. The dry density of sprayed bentonite at a boundary with concrete was the same as that at the center of the cross section. 3. The variation in densities of bentonite sprayed in the vertical downward and horizontal directions was small. Also, density reduction due to rebound during spraying was not seen. 4. Bentonite controlled by water content could be sprayed smoothly in the horizontal direction by a small machine. Also rebound could be collected by a machine conveying air. (author)

1994 Thermal spray industrial applications: Proceedings

International Nuclear Information System (INIS)

Berndt, C.C.; Sampath, S.

1994-01-01

The 7th National Thermal Spray Conference met on June 20--24, 1994, in Boston, Massachusetts. The conference was sponsored by the Thermal Spray Division of ASM International and co-sponsored by the American Welding Society, Deutscher Verband fur Schweisstechnik e.V., High Temperature Society of Japan, International Thermal Spray Association, and Japanese Thermal Spraying Society. The conference covered applications for automobiles, aerospace, petrochemicals, power generation, and biomedical needs. Materials included metals, ceramics, and composites with a broad range of process developments and diagnostics. Other sections included modeling and systems control; spray forming and reactive spraying; post treatment; process, structure and property relationships; mechanical properties; and testing, characterization and wear. One hundred and seventeen papers have been processed separately for inclusion on the data base

Plasma sprayed samarium--cobalt permanent magnets

International Nuclear Information System (INIS)

Willson, M.C.; Janowiecki, R.J.

1975-01-01

Samarium--cobalt permanent magnets were fabricated by arc plasma spraying. This process involves the injection of relatively coarse powder particles into a high-temperature gas for melting and spraying onto a substrate. The technique is being investigated as an economical method for fabricating cobalt--rare earth magnets for advanced traveling wave tubes and cross-field amplifiers. Plasma spraying permits deposition of material at high rates over large areas with optional direct bonding to the substrate, and offers the ability to fabricate magnets in a variety of shapes and sizes. Isotropic magnets were produced with high coercivity and good reproducibility in magnetic properties. Post-spray thermal treatments were used to enhance the magnetic properties of sprayed deposits. Samarium--cobalt magnets, sprayed from samarium-rich powder and subjected to post-spray heat treatment, displayed energy products in excess of 9 million gauss-oersteds and coercive forces of approximately 6000 oersteds. Bar magnet arrays were constructed by depositing magnets on ceramic substrates. (auth)

Plasma sprayed samarium--cobalt permanent magnets

International Nuclear Information System (INIS)

Willson, M.C.; Janowiecki, R.J.

1975-01-01

Samarium--Co permanent magnets were fabricated by arc plasma spraying. This process involves the injection of relatively coarse powder particles into a high temperature gas for melting and spraying onto a substrate. The technique is being investigated as an economical method for fabricating Co--rare earth magnets for advanced traveling wave tubes and cross-field amplifiers. Plasma spraying permits deposition of material at high rates over large areas with optional direct bonding to the substrate, and offers the ability to fabricate magnets in a variety of shapes and sizes. Isotropic magnets were produced with high coercivity and good reproducibility in magnetic properties. Post-spray thermal treatments were used to enhance the magnetic properties of sprayed deposits. Samarium--Co magnets, sprayed from Sm-rich powder and subjected to post-spray heat treatment, displayed energy products in excess of 9 million G-Oe and coercive forces of approximately 6000 Oe. Bar magnet arrays were constructed by depositing magnets on ceramic substrates

168 Hours Salt Fog Test

International Nuclear Information System (INIS)

Nur Ubaidah Saidin; Muhamad Daud; Siti Radiah Mohd Kamarudin

2011-01-01

This report explained the test conducted in salt fog chamber to evaluate the effectiveness of mild steel, coated with rust converter, for 168 hours in artificial seawater exposure. The samples were compared with mild steel coated with commercial primer. The tests were conducted followed ASTM B117. Individual pictures were taken of each sample before the tests began, at 24, 48, 72, 96, 120, 144 and 168 hours to see the progression of the corrosion. Results showed that the samples coated with rust converter provide a good significant protection against corrosion phenomenon than the samples coated with commercial primer that available in the market. (author)

Spray Drift Reduction Evaluations of Spray Nozzles Using a Standardized Testing Protocol

Science.gov (United States)

2010-07-01

Drop Size Characteristics in a Spray Using Optical Nonimaging Light-Scattering Instruments,” Annual Book of ASTM Standards, Vol. 14-02, ASTM...Test Method for Determining Liquid Drop Size Characteristics in a Spray Using Optical Non- imaging Light-Scattering Instruments 22. AGDISP Model

Drafting of the closure of the Asse salt mine. Final report

International Nuclear Information System (INIS)

Schneefuss, J.U.

2001-01-01

The report of the R and D-project 'Drafting of the closure of the Asse salt mine' contains the results of the first phases 'Basic findings' and 'Predrafting'. These phases were started after the backfilling of the south flank of the Asse salt mine was permitted in accordance to 2.2 of the operating program 'Future work at the Asse salt mine'. The knowledge status of May 2000 is reported. The result obtained in this program provides the basis for future drafting the closure of the Asse salt mine. The final results will include the long-term safety assessment to obtain the permission of the mining authorities for the closure of the Asse salt mine. The evaluation of the basic data has shown that further investigations are necessary. During the predrafting period the method for backfilling of the cavities, transport of the backfill and backfill and closure of the shafts were developed. Other parts of the concept for the closure are not finalized (control of the brine inflow when starting backfilling above the 658-m-level, minimizing of the possible effects of dissolution of carnallitite, avoiding of squeezing brines from deeper cavities through the disposal chambers etc.). (orig.) [de

A study on nozzle flow and spray characteristics of piezo injector for next generation high response injection

Energy Technology Data Exchange (ETDEWEB)

Lee, Jin Wook [Korea Institue of Machinery and Materials, Daejeon (Korea, Republic of); Min, Kyoung Doug [Seoul National University, Seoul (Korea, Republic of)

2006-06-15

Most diesel injector, which is currently used in high-pressure common rail fuel injection system of diesel engine, is driven by the solenoid coil energy for its needle movement. The main disadvantage of this solenoid-driven injector is a high power consumption, high power loss through solenoid coil and relatively fixed needle response's problem. In this study, a prototype piezo-driven injector, as a new injector mechanism driven by piezoelectric energy based on the concept of inverse piezo-electric effect, has been designed and fabricated to know the effect of piezo-driven injection processes on the diesel spray structure and internal nozzle flow. Firstly we investigated the spray characteristics in a constant volume chamber pressurized by nitrogen gas using the back diffusion light illumination method for high-speed temporal photography and also analyzed the inside nozzle flow by a fully transient simulation with cavitation model using VOF(Volume Of Fraction) method. The numerical calculation has been performed to simulate the cavitating flow of 3-dimensional real size single hole nozzle along the injection duration. Results were compared between a conventional solenoid-driven injector and piezo-driven injector, both equipped with the same micro-sac multi-hole injection nozzle. The experimental results show that the piezo-driven injector has short injection delay and a faster spray development and produces higher injection velocity than the solenoid-driven injector. And the predicted simulation results with the degree of cavitation's generation inside nozzle for faster needle response in a piezo-driven injector were reflected to spray development in agreement with the experimental spray images.

Effects of spray axis incident angle on heat transfer performance of rhombus-pitch shell-and-tube interior spray evaporator

International Nuclear Information System (INIS)

Lin, Ru-Li; Chang, Tong-Bou; Liang, Chih-Chang

2012-01-01

An interior spray method is proposed for enhancing the heat transfer performance of a compact rhombus-pitch shell-and-tube spray evaporator. The experimental results show that the shell-side heat transfer coefficient obtained using the proposed spray method is significantly higher than that achieved in a conventional flooded-type evaporator. Four different spray axis incident angles (0 .deg., 45 .deg., 60 .deg. and 75 .deg.) are tested in order to investigate the effect of the spray inclination angle on the heat transfer performance of the spray evaporator system. It is shown that the optimal heat transfer performance is obtained using a spray axis incident angle of 60 .deg.

Fixed automated spray technology.

Science.gov (United States)

2011-04-19

This research project evaluated the construction and performance of Boschungs Fixed Automated : Spray Technology (FAST) system. The FAST system automatically sprays de-icing material on : the bridge when icing conditions are about to occur. The FA...

Chromium-free conversion coatings based on inorganic salts (Zr/Ti/Mn/Mo) for aluminum alloys used in aircraft applications

Energy Technology Data Exchange (ETDEWEB)

Santa Coloma, P., E-mail: patricia.santacoloma@tecnalia.com [TECNALIA Research & Innovation, Parque Tecnológico de San Sebastián, Mikeletegi Pasealekua 2, E-20009 Donostia-San Sebastián, Gipuzkoa (Spain); Izagirre, U.; Belaustegi, Y.; Jorcin, J.B.; Cano, F.J. [TECNALIA Research & Innovation, Parque Tecnológico de San Sebastián, Mikeletegi Pasealekua 2, E-20009 Donostia-San Sebastián, Gipuzkoa (Spain); Lapeña, N. [Boeing Research & Technology Europe, S.L.U., Avenida Sur del Aeropuerto de Barajas 38, Building 4 – 3rd Floor, E-28042 Madrid (Spain)

2015-08-01

Highlights: • Chromium-free conversion coatings for corrosion protection of aluminum alloys. • Salt spray and potentiodynamic sweep tests to study the corrosion behavior. • Local deposits on Cu-rich intermetallic particles enhanced corrosion resistance. • Surface characterization to relate bath's composition and corrosion resistance. • Best corrosion protection with conversion baths without titanium salts. - Abstract: Novel chromium-free conversion coatings based on Zr/Ti/Mn/Mo compounds were developed at a pilot scale to improve the corrosion resistance of the AA2024-T3 and AA7075-T6 aluminum alloys for aircraft applications. The influence of the presence of Zr and Ti in the Zr/Ti/Mn/Mo conversion bath's formulation on the corrosion resistance of the coated alloys was investigated. The corrosion resistance provided by the conversion coatings was evaluated by salt spray exposure and potentiodynamic sweeps. Optical and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS) and atomic force microscopy (AFM) operating in the Kelvin Probe mode (SKPFM) were used to provide microstructural information of the coated samples that achieved the best results in the corrosion tests. The salt spray test evidenced the higher corrosion resistance of the coated samples compared to the bare surfaces for both alloys. The potentiodynamic tests showed that the corrosion current density decreased for coated AA7075-T6 and AA2024-T3 alloys, which indicated an obvious improvement of the corrosion resistance with all the processes for both alloys. Although the corrosion resistance of the coated samples appeared to be higher for the alloy AA7075-T6 than for the alloy AA2024-T3, both alloys achieved the best corrosion protection with the coatings deposited from conversion bath formulations containing no titanium salts. The microscopy analysis on the coated AA7075-T6 samples revealed that a local deposition of Zr compounds and, possibly, an

Chromium-free conversion coatings based on inorganic salts (Zr/Ti/Mn/Mo) for aluminum alloys used in aircraft applications

International Nuclear Information System (INIS)

Santa Coloma, P.; Izagirre, U.; Belaustegi, Y.; Jorcin, J.B.; Cano, F.J.; Lapeña, N.

2015-01-01

Highlights: • Chromium-free conversion coatings for corrosion protection of aluminum alloys. • Salt spray and potentiodynamic sweep tests to study the corrosion behavior. • Local deposits on Cu-rich intermetallic particles enhanced corrosion resistance. • Surface characterization to relate bath's composition and corrosion resistance. • Best corrosion protection with conversion baths without titanium salts. - Abstract: Novel chromium-free conversion coatings based on Zr/Ti/Mn/Mo compounds were developed at a pilot scale to improve the corrosion resistance of the AA2024-T3 and AA7075-T6 aluminum alloys for aircraft applications. The influence of the presence of Zr and Ti in the Zr/Ti/Mn/Mo conversion bath's formulation on the corrosion resistance of the coated alloys was investigated. The corrosion resistance provided by the conversion coatings was evaluated by salt spray exposure and potentiodynamic sweeps. Optical and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS) and atomic force microscopy (AFM) operating in the Kelvin Probe mode (SKPFM) were used to provide microstructural information of the coated samples that achieved the best results in the corrosion tests. The salt spray test evidenced the higher corrosion resistance of the coated samples compared to the bare surfaces for both alloys. The potentiodynamic tests showed that the corrosion current density decreased for coated AA7075-T6 and AA2024-T3 alloys, which indicated an obvious improvement of the corrosion resistance with all the processes for both alloys. Although the corrosion resistance of the coated samples appeared to be higher for the alloy AA7075-T6 than for the alloy AA2024-T3, both alloys achieved the best corrosion protection with the coatings deposited from conversion bath formulations containing no titanium salts. The microscopy analysis on the coated AA7075-T6 samples revealed that a local deposition of Zr compounds and, possibly, an

Determination of soil mechanics of salt rock as a potential backfilling material in an underground repository

International Nuclear Information System (INIS)

Kappei, G.

1987-09-01

Within the framework of the research and development project 'Backfilling and sealing of boreholes, chambers and roadways in a final dump', the Institute for Underground Dumping chose - from the broad range of possible stowing materials - the material 'salt spoil' and investigated its soil-mechanical properties in detail. Besides the implementation of soil-mechanical standard analyses (determination of the grain size distribution, bulk density, limits of storage density, proctor density, permeabilities, and shear strength) of two selected salt spoils (heap salt and rock salt spoil), the studies concentrated on the determination of the compression behaviour of salt spoil. In order to obtain data on the compaction behaviour of this material in the case of increasing stress, compression tests with obstructed lateral expansion were carried out on a series of spoil samples differing mainly in the composition of grain sizes. In addition to this, for a small number of samples of rock salt spoil, the creep behaviour at constant stress was determined after the compaction phase. (orig./RB) [de

Soot temperature and KL factor for biodiesel and diesel spray combustion in a constant volume combustion chamber

KAUST Repository

Zhang, Ji; Jing, Wei; Roberts, William L.; Fang, Tiegang

2013-01-01

This paper presents measurements of the soot temperature and KL factor for biodiesel and diesel combustion in a constant volume chamber using a two-color technique. This technique uses a high-speed camera coupled with two narrowband filters (550. nm

LSPRAY-IV: A Lagrangian Spray Module

Science.gov (United States)

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.

Droplets and sprays

CERN Document Server

Sazhin, Sergei

2014-01-01

Providing a clear and systematic description of droplets and spray dynamic models, this book maximises reader insight into the underlying physics of the processes involved, outlines the development of new physical and mathematical models, and broadens understanding of interactions between the complex physical processes which take place in sprays. Complementing approaches based on the direct application of computational fluid dynamics (CFD), Droplets and Sprays treats both theoretical and practical aspects of internal combustion engine process such as the direct injection of liquid fuel, subcritical heating and evaporation. Includes case studies that illustrate the approaches relevance to automotive applications,  it is also anticipated that the described models can find use in other areas such as in medicine and environmental science.

Effects of isothermal treatment on microstructure and scratch test behavior of plasma sprayed zirconia coatings

Directory of Open Access Journals (Sweden)

Veloso Guilherme

2004-01-01

Full Text Available The increase of the petroleum cost in the last decades revitalized the interest for lighter and more economic vehicles. Simultaneously, the demand for safe and unpolluted transports grows. The application of thermal barriers coatings (TBC on combustion chamber and on flat surface of pistons reduces the thermal losses of the engines, resulting in higher temperatures in the combustion chamber. This fact contributes to the improvement of the thermal efficiency (performance and for the reduction of incomplete combustion. Supported on these initial ideas, thermal barriers coatings constituted by CaO partially stabilized zirconia were produced and their microstructure examined. This coating still presents some drawbacks associated with thermal stresses and permeability to oxidizing gases, which will, eventually, lead to failure of the TBC by spallation. The failure may, in general, be associated to one of three factors: oxide growth at the ceramic-metal interface, formed during thermal cycling; stress build-up due to thermal cycling; and metal-oxide interface segregation, mainly of S. However, it is also relevant to understand the behavior of TBC's under isothermal oxidation. Therefore, this paper investigates the effect of oxidation on the adherence of thermal sprayed coatings. The adherence was measured by linear scratching tests, widely used for thin coatings. Plasma sprayed calcia partially stabilized zirconia was used as TBC and Ni-5%Al as bond coat, with Al substrates. Coated samples were submitted to heat treatments at 500 °C, for 50 h. The microstructures were examined by optical light microscopy, X-ray diffraction, profilometry and SEM.

Alleviation of salt-induced oxidative damage by 5-aminolevulinic acid in wheat seedlings

Science.gov (United States)

Genişel, Mucip; Erdal, Serkan

2016-04-01

The aim of this study was to elucidate how 5-aminolevulinic acid (ALA), the precursor of chlorophyll compounds, affects the defence mechanisms of wheat seedlings induced by salt stress. To determine the possible stimulative effects of ALA against salinity, 11-day old wheat seedlings were sprayed with ALA at two different concentrations (10 and 20 mg.l-1) and then stressed by exposure to salt (150 mM NaCl). The salt stress led to significant changes in the antioxidant activity. While guaiacol peroxidase activity decreased, the activities of superoxide dismutase, catalase, and ascorbate peroxidase markedly increased under salt stress. Compared to the salt stress alone, the application of ALA beforehand further increased the activity of these enzymes. This study is the first time the effects of ALA have been monitored with regard to protein content and the isoenzyme profiles of the antioxidant enzymes. Although the salt stress reduced both the soluble protein content and protein band intensities, pre-treating with ALA significantly mitigated these stress-induced reductions. The data for the isoenzyme profiles of the antioxidant enzymes paralleled that of the ALA-induced increases in antioxidant activity. As a consequence of the high antioxidant activity in the seedlings pre-treated with ALA, the stress-induced elevations in the reactive oxygen species, superoxide anion, and hydrogen peroxide contents and lipid peroxidation levels were markedly diminished. Taken together, this data demonstrated that pre-treating with ALA confers resistance to salt stress by modulating the protein synthesis and antioxidant activity in wheat seedlings.

The feasibility study of hot cell decontamination by the PFC spray method

International Nuclear Information System (INIS)

Hui-Jun Won; Chong-Hun Jung; Jei-Kwon Moon

2008-01-01

module. A performance test on each module was executed and the results have been reported. A combined test of the four modules, however, has not been performed as yet. The main objective of the present study is to demonstrate the feasibility of the full PFC spray decontamination process. Decontamination of the inside of the IMEF hot cell by the PFC spray method was also performed. PFC spray decontamination process was demonstrated by using a surrogate wall contaminated with Eu 2 O 3 powder. The spray pressure was 41 kgf/cm 2 , the orifice diameter was 0.2 mm and the spray velocity was 0.2 L/min. And, the decontaminated area was 100 cm 2 . From previous test results, we found that the decontamination factor of the PFC spray method was in the range from 9.6 to 62.4. When the decontamination efficiency of Co-60 was high, then the decontamination efficiency of Cs-137 was also high. As the surface roughness of the specimen increased, the PFC spray decontamination efficiency decreased. Inferring from the previous results, the surface of the surrogate wall was cleaned by the PFC spray method. The vacuum cup of the collection module operated well and gathered more than 99 % of the PFC solution. Also, filtration and distillation modules operated well. All the filtered PFC solution flowed to the storage chamber where some of the PFC solution was distilled. The coolant of the distillation module was a dry ice. And, the recycled solution was transferred to the spray module by a high pressure pump. To evaluate the PFC spray decontamination efficiency, a smear device was fabricated and operated by a manipulator. Before and after decontamination, a smear test was performed. The tested area was 100 cm 2 and the radioactivity was estimated indirectly by measuring the radioactivity of the filter paper. The average decontamination factor was in the range between 10 and 15. One application time was 2 minutes. The sprayed PFC solution was collected by the vacuum cup and it was stored in the

Rapid in situ synthesis of spherical microflower Pt/C catalyst via spray-drying for high performance fuel cell application

Energy Technology Data Exchange (ETDEWEB)

Balgis, R.; Ogi, T.; Okuyama, K. [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, Higashi Hiroshima, Hiroshima (Japan); Anilkumar, G.M.; Sago, S. [Research and Development Centre, Noritake Co., Ltd., Higashiyama, Miyoshi, Aichi (Japan)

2012-08-15

A facile route for the rapid in situ synthesis of platinum nanoparticles on spherical microflower carbon has been developed. An aqueous precursor slurry containing carbon black, polystyrene latex (PSL), polyvinyl alcohol, and platinum salt was spray-dried, followed by calcination to simultaneously reduce platinum salt and to decompose PSL particles. Prepared Pt/C catalyst showed high-performance electrocatalytic activity with excellent durability. The mass activity and specific activity values were 132.26 mA mg{sup -1} Pt and 207.62 {mu}A cm{sup -2} Pt, respectively. This work presents a future direction for the production of high-performance Pt/C catalyst in an industrial scale. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

COUPLED ATOMIZATION AND SPRAY MODELLING IN THE SPRAY FORMING PROCESS USING OPENFOAM

DEFF Research Database (Denmark)

Gjesing, Rasmus; Hattel, Jesper Henri; Fritsching, Udo

2009-01-01

The paper presents a numerical model capable of simulating the atomization, break-up and in-flight spray phenomena in the spray forming process. The model is developed and implemented in the freeware code openFOAM. The focus is on studying the coupling effect of the melt break-up phenomena...

Increases in wintertime PM2.5 sodium and chloride linked to snowfall and road salt application

Science.gov (United States)

Kolesar, Katheryn R.; Mattson, Claire N.; Peterson, Peter K.; May, Nathaniel W.; Prendergast, Rashad K.; Pratt, Kerri A.

2018-03-01

The application of salts and salty brines to roads is common practice during the winter in many urban environments. Road salts can become aerosolized, thereby injecting sodium and chloride particulate matter (PM) into the atmosphere. Here, data from the United States Environmental Protection Agency Chemical Speciation Monitoring Network were used to assess temporal trends of sodium and chloride PM2.5 (PM road salt aerosols. Sodium and chloride PM2.5 concentrations were an average of three times higher in the winter, as compared to the summer, for locations with greater than 25 cm of average annual snowfall. Winter urban chloride PM2.5 concentrations attributed to road salt can even sometimes rival those of coastal sea spray aerosol-influenced sites. In most snow-influenced cities, chloride and sodium PM2.5 concentrations were positively correlated with snowfall; however, this relationship is complicated by differences in state and local winter maintenance practices. This study highlights the ubiquity of road salt aerosols in the United States and their potential impact on wintertime urban air quality, particularly due to the potential for multiphase reactions to liberate chlorine from the particle-phase. Since road salt application is a common practice in wintertime urban environments across the world, it is imperative that road salt application emissions, currently not included in inventories, and its impacts be investigated through measurements and modeling.

Effect of Combustion-chamber Shape on the Performance of a Prechamber Compression-ignition Engine

Science.gov (United States)

Moore, C S; Collins, J H , Jr

1934-01-01

The effect on engine performance of variations in the shape of the prechamber, the shape and direction of the connecting passage, the chamber volume using a tangential passage, the injection system, and the direction od the fuel spray in the chamber was investigated using a 5 by 7 inch single-cylinder compression-ignition engine. The results show that the performance of this engine can be considerably improved by selecting the best combination of variables and incorporating them in a single design. The best combination as determined from these tests consisted of a disk-shaped chamber connected to the cylinder by means of a flared tangential passage. The fuel was injected through a single-orifice nozzle directed normal to the air swirl and in the same plane. At an engine speed of 1,500 r.p.m. and with the theoretical fuel quantity for no excess air, the engine developed a brake mean effective pressure of 115 pounds per square inch with a fuel consumption of 0.49 pound per brake horsepower-hour and an explosion pressure of 820 pounds per square inch. A brake mean effective pressure of 100 pounds per square inch with a brake-fuel consumption of 0.44 pound per horsepower-hour at 1,500 r.p.m. was obtained.

Ionization chamber

International Nuclear Information System (INIS)

Jilbert, P.H.

1975-01-01

The invention concerns ionization chambers with particular reference to air-equivalent ionization chambers. In order to ensure that similar chambers have similar sensitivities and responses the surface of the chamber bounding the active volume carries a conducting material, which may be a colloidal graphite, arranged in the form of lines so that the area of the conducting material occupies only a small proportion of the area of said surface. (U.S.)

OPTICAL PROPERTIES OF Al:ZnO THIN FILM DEPOSITED BY DIFFERENT SOL-GEL TECHNIQUES: ULTRASONIC SPRAY PYROLYSIS AND DIP-COATING

Directory of Open Access Journals (Sweden)

Ebru Gungor

2016-08-01

Full Text Available Undoped and Al-doped ZnO polycrystalline thin films have been fabricated on glass substrates by using a computer-controlled dip coating (DC and ultrasonic spray pyrolysis (USP systems. The film deposition parameters of DC process were optimized for the samples. In this technique, the substrate was exposed to temperature gradient using a tube furnace. In the study, the other solvent-based technique was conventional USP. The zinc salt and Al salt concentrations in the solution were kept constant as 0.1 M and 2% of Zn salt’s molarity, respectively. The optical properties were compared for the films deposited two different techniques. The optical transmission of Al:ZnO/Glass/Al:ZnO sample dip coated and  the optical transmission of Al:ZnO/Glass sample ultrasonically sprayed were determined higher than 80% in the visible and near infrared region. Experimental optical transmittance spectra of the films in the forms of FilmA/Glass/FilmA and FilmA/glass were used to determine the optical constants. It was observed that the optical band gaps of Al doped ZnO films onto glass substrate were increases with increase of Al content and the absorption edge shifted to the shorter wavelength (blue shift compared with the undoped ZnO thin film.

Experimental Study on the Hygrothermal Behavior of a Coated Sprayed Hemp Concrete Wall

Directory of Open Access Journals (Sweden)

Anthony Magueresse

2013-01-01

Full Text Available Hemp concrete is a sustainable lightweight concrete that became popular in the field of building construction because of its thermal and environmental properties. However; available experimental data on its hygrothermal behavior are rather scarce in the literature. This paper describes the design of a large-scale experiment developed to investigate the hygrothermal behavior of hemp concrete cast around a timber frame through a spraying process; and then coated with lime-based plaster. The equipment is composed of two climatic chambers surrounding the tested wall. The experiment consists of maintaining the indoor climate at constant values and applying incremental steps of temperature; relative humidity or vapor pressure in the outdoor chamber. Temperature and relative humidity of the room air and on various depths inside the wall are continuously registered during the experiments and evaporation phenomena are observed. The influence of the plaster on the hygrothermal behavior of hemp concrete is investigated. Moreover; a comparison of experimental temperatures with numerical results obtained from a purely conductive thermal model is proposed. Comparing the model with the measured data gave satisfactory agreement.

Diesel spray characterization; Dieselmoottorin polttoainesuihkujen ominaisuudet

Energy Technology Data Exchange (ETDEWEB)

Pitkaenen, J.; Turunen, R.; Paloposki, T.; Rantanen, P.; Virolainen, T. [Helsinki Univ. of Technology, Otaniemi (Finland). Internal Combustion Engine Lab.

1997-10-01

Fuel injection of diesel engines will be studied using large-scale models of fuel injectors. The advantage of large-scale models is that the measurement of large-scale diesel sprays will be easier than the measurement of actual sprays. The objective is to study the break-up mechanism of diesel sprays and to measure drop size distributions in the inner part of the spray. The results will be used in the development of diesel engines and diesel fuels. (orig.)

Head spray nozzle in reactor pressure vessel

International Nuclear Information System (INIS)

Hatano, Shun-ichi.

1990-01-01

In a reactor pressure vessel of a BWR type reactor, a head spray nozzle is used for cooling the head of the pressure vessel and, in view of the thermal stresses, it is desirable that cooling is applied as uniformly as possible. A conventional head spray is constituted by combining full cone type nozzles. Since the sprayed water is flown down upon water spraying and the sprayed water in the vertical direction is overlapped, the flow rate distribution has a high sharpness to form a shape as having a maximum value near the center and it is difficult to obtain a uniform flow rate distribution in the circumferential direction. Then, in the present invention, flat nozzles each having a spray water cross section of laterally long shape, having less sharpness in the circumferential distribution upon spraying water to the inner wall of the pressure vessel and having a wide angle of water spray are combined, to make the flow rate distribution of spray water uniform in the inner wall of the pressure vessel. Accordingly, the pressure vessel can be cooled uniformly and thermal stresses upon cooling can be decreased. (N.H.)

Multiple-Nozzle Spray Head Applies Foam Insulation

Science.gov (United States)

Walls, Joe T.

1993-01-01

Spray head equipped with four-nozzle turret mixes two reactive components of polyurethane and polyisocyanurate foam insulating material and sprays reacting mixture onto surface to be insulated. If nozzle in use becomes clogged, fresh one automatically rotated into position, with minimal interruption of spraying process. Incorporates features recirculating and controlling pressures of reactive components to maintain quality of foam by ensuring proper blend at outset. Also used to spray protective coats on or in ships, aircraft, and pipelines. Sprays such reactive adhesives as epoxy/polyurethane mixtures. Components of spray contain solid-particle fillers for strength, fire retardance, toughness, resistance to abrasion, or radar absorption.

Water spray interaction with air-steam mixtures under containment spray conditions: experimental study in the TOSQAN facility

Energy Technology Data Exchange (ETDEWEB)

Porcheron, E.; Lemaitre, P.; Malet, J.; Nuboer, A.; Brun, P.; Bouilloux, L.; Vendel, J. [Institut de Radioprotection et de Surete Nucleaire (IRSN), Direction de la Surete des Usines, des laboratoires, des transports et des dechets, Saclay, BP 68 - 91192 Gif-sur-Yvette cedex (France)

2005-07-01

Full text of publication follows: During the course of an hypothetical severe accident in a Pressurized Water Reactor (PWR), hydrogen can be produced by the reactor core oxidation and distributed into the reactor containment according to convection flows and steam wall condensation. In order to assess the risk of detonation generated by a high local hydrogen concentration, hydrogen distribution in the containment has to be known. The TOSQAN experimental program has been created to simulate typical accidental thermal hydraulic flow conditions in the reactor containment. The present work is devoted to study the interaction of a water spray injection used as a mitigation mean in order to reduce containment pressure and to produce a mixing of air, steam and hydrogen induced by spray entrainment and condensation on droplet. In order to have a better understanding of physical phenomena, we need to make a detailed characterization of the spray and the gas. The TOSQAN facility that is highly instrumented with non-intrusive diagnostics consists in a closed cylindrical vessel (7 m{sup 3} volume, 4 m high, 1.5 m i.d.) into which steam is injected. Water droplets size is measured in the vessel by the Interferometric Laser Imaging for Droplet Sizing technique. Droplet velocity is obtained by Particle Image Velocimetry and Laser Doppler Velocimetry, and droplet temperature is measured by global rainbow refractometry. Gas concentration measurements are performed by Spontaneous Raman Scattering. The walls of the vessel are thermostatically controlled by heated oil circulation. Inner spray system that is located on the top of the enclosure on the vertical axis, is composed of a single nozzle producing a full cone water spray. Spray test scenario consists of water spray injection in TOSQAN that is first pressurized with a steam injection (steam injection is stopped before spray injection). Water spray falling into the sump is removed to avoid accumulation and evaporation

Gas entrainment by one single French PWR spray, SARNET-2 spray benchmark

Energy Technology Data Exchange (ETDEWEB)

Malet, J., E-mail: jeanne.malet@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire, Saclay (France); Mimouni, S., E-mail: stephane.mimouni@edf.fr [Electricité de France, EDF MF2E, Chatou (France); Manzini, G., E-mail: giovanni.manzini@rse-web.it [RSE, Milano (Italy); Xiao, J., E-mail: jianjun.xiao@kit.edu [IKET, KIT, Karlsruhe (Germany); Vyskocil, L., E-mail: vyl@ujv.cz [UJV Rez (Czech Republic); Siccama, N.B., E-mail: siccama@nrg.eu [NRG, Safety and Power (Netherlands); Huhtanen, R., E-mail: risto.huhtanen@vtt.fi [VTT, PO Box 1000, FI-02044 VTT (Finland)

2015-02-15

Highlights: • This paper presents a benchmark performed in the frame of the SARNET-2 EU project. • It concerns momentum transfer between a PWR spray and the surrounding gas. • The entrained gas velocities can vary up to 100% from one code to another. • Simplified boundary conditions for sprays are generally used by the code users. • It is shown how these simplified conditions impact the gas entrainment. - Abstract: This paper presents a benchmark performed in the frame of the SARNET-2 EU project, dealing with momentum transfer between a real-scale PWR spray and the surrounding gas. It presents a description of the IRSN tests on the CALIST facility, the participating codes (8 contributions), code-experiment and code-to-code comparisons. It is found that droplet velocities are almost well calculated one meter below the spray nozzle, even if the spread of the spray is not recovered and the values of the entrained gas velocity vary up to 100% from one code to another. Concerning sensitivity analysis, several ‘simplifications’ have been made by the contributors, especially based on the boundary conditions applied at the location where droplets are injected. It is shown here that such simplifications influence droplet and entrained gas characteristics. The next step will be to translate these conclusions in terms of variables representative of interesting parameters for nuclear safety.

Gas entrainment by one single French PWR spray, SARNET-2 spray benchmark

International Nuclear Information System (INIS)

Malet, J.; Mimouni, S.; Manzini, G.; Xiao, J.; Vyskocil, L.; Siccama, N.B.; Huhtanen, R.

2015-01-01

Highlights: • This paper presents a benchmark performed in the frame of the SARNET-2 EU project. • It concerns momentum transfer between a PWR spray and the surrounding gas. • The entrained gas velocities can vary up to 100% from one code to another. • Simplified boundary conditions for sprays are generally used by the code users. • It is shown how these simplified conditions impact the gas entrainment. - Abstract: This paper presents a benchmark performed in the frame of the SARNET-2 EU project, dealing with momentum transfer between a real-scale PWR spray and the surrounding gas. It presents a description of the IRSN tests on the CALIST facility, the participating codes (8 contributions), code-experiment and code-to-code comparisons. It is found that droplet velocities are almost well calculated one meter below the spray nozzle, even if the spread of the spray is not recovered and the values of the entrained gas velocity vary up to 100% from one code to another. Concerning sensitivity analysis, several ‘simplifications’ have been made by the contributors, especially based on the boundary conditions applied at the location where droplets are injected. It is shown here that such simplifications influence droplet and entrained gas characteristics. The next step will be to translate these conclusions in terms of variables representative of interesting parameters for nuclear safety

14 CFR 23.239 - Spray characteristics.

Science.gov (United States)

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 of...

14 CFR 29.239 - Spray characteristics.

Science.gov (United States)

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 characteristics...

14 CFR 27.239 - Spray characteristics.

Science.gov (United States)

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 characteristics...

A comparison of biological effect and spray liquid distribution and deposition for different spray application techniques in different crops

OpenAIRE

Larsolle, Anders; Wretblad, Per; Westberg, Carl

2002-01-01

The objective of this study was to compare a selection of spray application techniques with different application volumes, with respect to the spray liquid distribution on flat surfaces, the deposition in fully developed crops and the biological effect. The spray application techniques in this study were conventional spray technique with three different nozzles: Teelet XR, Lechler ID and Lurmark DriftBeta, and also AirTec, Danfoil, Hardi Twin, Kyndestoit and Släpduk. The dynamic spray liquid ...

Transient analysis of intermittent multijet sprays

Energy Technology Data Exchange (ETDEWEB)

Panao, Miguel R.O.; Moreira, Antonio Luis N. [Universidade Tecnica de Lisboa, IN, Center for Innovation, Technology and Policy Research, Instituto Superior Tecnico, Lisboa (Portugal); Durao, Diamantino G. [Universidade Lusiada, Lisboa (Portugal)

2012-07-15

This paper analyzes the transient characteristics of intermittent sprays produced by the single-point impact of multiple cylindrical jets. The aim is to perform a transient analysis of the intermittent atomization process to study the effect of varying the number of impinging jets in the hydrodynamic mechanisms of droplet formation. The results evidence that hydrodynamic mechanisms underlying the physics of ligament fragmentation in 2-impinging jets sprays also apply to sprays produced with more than 2 jets during the main period of injection. Ligaments detaching from the liquid sheet, as well as from its bounding rim, have been identified and associated with distinct droplet clusters, which become more evident as the number of impinging jets increases. Droplets produced by detached ligaments constitute the main spray, and their axial velocity becomes more uniformly distributed with 4-impinging jets because of a delayed ligament fragmentation. Multijet spray dispersion patterns are geometric depending on the number of impinging jets. Finally, an analysis on the Weber number of droplets suggests that multijet sprays are more likely to deposit on interposed surfaces, thus becoming a promising and competitive atomization solution for improving spray cooling. (orig.)

Glove box chamber

International Nuclear Information System (INIS)

Cox, M.E.; Cox, M.E.

1975-01-01

An environmental chamber is described which enables an operator's hands to have direct access within the chamber without compromising a special atmosphere within such chamber. A pair of sleeves of a flexible material are sealed to the chamber around associated access apertures and project outwardly from such chamber. Each aperture is closed by a door which is openable from within the sleeve associated therewith so that upon an operator inserting his hand and arm through the sleeve, the operator can open the door to have access to the interior of the chamber. A container which is selectively separable from the remainder of the chamber is also provided to allow objects to be transferred from the chamber without such objects having to pass through the ambient atmosphere. An antechamber permitting objects to be passed directly into the chamber from the ambient atmosphere is included. (auth)

Droplet spectrum of a spray nozzle under different weather conditions

Directory of Open Access Journals (Sweden)

Christiam Felipe Silva Maciel

Full Text Available ABSTRACT The application of pesticides is always susceptible to losses through evaporation and drift of the spray droplets. With these losses, a smaller amount of pesticide reaches the target, possibly impairing the efficiency of phytosanitary control. Due to these concerns, the aim of this study was to evaluate the interference of weather conditions in the droplet spectrum produced by hydraulic spraying. To carry out the work, it was necessary to build an experimental system. This consisted of a laser particle-size analyser, hydraulic nozzle (Jacto JSF 11002, stationary sprayer, gas heater, wind tunnel, climate chamber (with the aim of maintaining the internal psychrometry similar to that of the air exiting the wind tunnel, collector, and temperature and RH sensors. The weather conditions for the study included vapour pressure deficits (VPD of 5, 9.4, 20, 30.6 and 35 hPa, and air velocities of 2, 3.6, 7.4, 11.2 and 12.8 km h-1. A Rotatable Central Composite Design was used, and the data related using Response Surface Methodology. The wind caused such a sharp drift in the fine droplets, that it greatly affected the behaviour of the entire droplet spectrum, as well as hiding the effect of the VPD. However, the conclusion is that drift and evaporation both act on the coarser droplets.

Effectiveness of containment sprays in containment management

International Nuclear Information System (INIS)

Nourbakhsh, H.P.; Perez, S.E.; Lehner, J.R.

1993-05-01

A limited study has been performed assessing the effectiveness of containment sprays-to mitigate particular challenges which may occur during a severe accident. Certain aspects of three specific topics related to using sprays under severe accident conditions were investigated. The first was the effectiveness of sprays connected to an alternate water supple and pumping source because the actual containment spray pumps are inoperable. This situation could occur during a station blackout. The second topic concerned the adverse as well as beneficial effects of using containment sprays during severe accident scenario where the containment atmosphere contains substantial quantities of hydrogen along with steam. The third topic was the feasibility of using containment sprays to moderate the consequences of DCH

wire chamber

CERN Multimedia

Proportional multi-wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle. Proportional wire chambers allow a much quicker reading than the optical or magnetoscriptive readout wire chambers.

Self-healing atmospheric plasma sprayed Mn1.0Co1.9Fe0.1O4 protective interconnector coatings for solid oxide fuel cells

Science.gov (United States)

Grünwald, Nikolas; Sebold, Doris; Sohn, Yoo Jung; Menzler, Norbert Heribert; Vaßen, Robert

2017-09-01

Dense coatings on metallic interconnectors are necessary to suppress chromium poisoning of SOFC cathodes. Atmospherically plasma sprayed (APS) Mn1.0Co1.9Fe0.1O4 (MCF) protective layers demonstrated reduced chromium related degradation in laboratory and stack tests. Previous analyses revealed strong microstructural changes comparing the coating's as-sprayed and operated condition. This work concentrates on the layer-densification and crack-healing observed by annealing APS-MCF in air, which simulates the cathode operation conditions. The effect is described by a volume expansion induced by a phase transformation. Reducing conditions during the spray process lead to a deposition of the MCF in a metastable rock salt configuration. Annealing in air activates diffusion processes for a phase transformation to the low temperature stable spinel phase (T coating. The process decelerates when the cracks are closed, as the gas route is blocked and further oxidation continues over solid state diffusion. The self-healing abilities of metastable APS coatings could be interesting for other applications.

Preparation of cellulose based microspheres by combining spray coagulating with spray drying.

Science.gov (United States)

Wang, Qiao; Fu, Aiping; Li, Hongliang; Liu, Jingquan; Guo, Peizhi; Zhao, Xiu Song; Xia, Lin Hua

2014-10-13

Porous microspheres of regenerated cellulose with size in range of 1-2 μm and composite microspheres of chitosan coated cellulose with size of 1-3 μm were obtained through a two-step spray-assisted approach. The spray coagulating process must combine with a spray drying step to guarantee the formation of stable microspheres of cellulose. This approach exhibits the following two main virtues. First, the preparation was performed using aqueous solution of cellulose as precursor in the absence of organic solvent and surfactant; Second, neither crosslinking agent nor separated crosslinking process was required for formation of stable microspheres. Moreover, the spray drying step also provided us with the chance to encapsulate guests into the resultant cellulose microspheres. The potential application of the cellulose microspheres acting as drug delivery vector has been studied in two PBS (phosphate-buffered saline) solution with pH values at 4.0 and 7.4 to mimic the environments of stomach and intestine, respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

Activities concerning plugging and sealing in the Asse salt mine

International Nuclear Information System (INIS)

Kappei, G.

1986-01-01

A large amount of experience regarding chamber sealing has been acquired in the Asse salt mine over the years. Various techniques were tested such as, for example, the pneumatic or pumping technique as well as the possible use of different constructional materials. The schematic construction of several existing bulkheads and the geotechnical instrumentation required for monitoring are described. Results of stress measurements from within a four year's old bulkhead are given. (orig./DG)

The atomization and burning of biofuels in the combustion chambers of gas turbine engines

Science.gov (United States)

Maiorova, A. I.; Vasil'ev, A. Yu; Sviridenkov, A. A.; Chelebyan, O. G.

2017-11-01

The present work analyzes the effect of physical properties of liquid fuels with high viscosity (including biofuels) on the spray and burning characteristics. The study showed that the spray characteristics behind devices well atomized fuel oil, may significantly deteriorate when using biofuels, until the collapse of the fuel bubble. To avoid this phenomenon it is necessary to carry out the calculation of the fuel film form when designing the nozzles. As a result of this calculation boundary curves in the coordinates of the Reynolds number on fuel - the Laplace number are built, characterizing the transition from sheet breakup to spraying. It is shown that these curves are described by a power function with the same exponent for nozzles of various designs. The swirl of air surrounding the nozzle in the same direction, as the swirl of fuel film, can significantly improve the performance of atomization of highly viscous fuel. Moreover the value of the tangential air velocity has the determining influence on the film shape. For carrying out of hot tests in aviation combustor some embodiments of liquid fuels were proved and the most preferred one was chosen. Fire tests of combustion chamber compartment at conventional fuel has shown comprehensible characteristics, in particular wide side-altars of the stable combustion. The blended biofuel application makes worse combustion stability in comparison with kerosene. A number of measures was recommended to modernize the conventional combustors when using biofuels in gas turbine engines.

Test chamber

NARCIS (Netherlands)

Leferink, Frank Bernardus Johannes

2009-01-01

A test chamber for measuring electromagnetic radiation emitted by an apparatus to be tested or for exposing an apparatus to be tested to an electromagnetic radiation field. The test chamber includes a reverberation chamber made of a conductive tent fabric. To create a statistically uniform field in

Resistance of Coatings for Boiler Components of Waste-to-Energy Plants to Salt Melts Containing Copper Compounds

Science.gov (United States)

Galetz, Mathias Christian; Bauer, Johannes Thomas; Schütze, Michael; Noguchi, Manabu; Cho, Hiromitsu

2013-06-01

The accelerating effect of heavy metal compounds on the corrosive attack of boiler components like superheaters poses a severe problem in modern waste-to-energy plants (WTPs). Coatings are a possible solution to protect cheap, low alloyed steel substrates from heavy metal chloride and sulfate salts, which have a relatively low melting point. These salts dissolve many alloys, and therefore often are the limiting factor as far as the lifetime of superheater tubes is concerned. In this work the corrosion performance under artificial salt deposits of different coatings, manufactured by overlay welding, thermal spraying of self-fluxing as well as conventional systems was investigated. The results of our studies clearly demonstrate the importance of alloying elements such as molybdenum or silicon. Additionally, the coatings have to be dense and of a certain thickness in order to resist the corrosive attack under these severe conditions.

An evaluation of the electric arc spray and (HPPS) processes for the manufacturing of high power plasma spraying MCrAIY coatings

Science.gov (United States)

Sacriste, D.; Goubot, N.; Dhers, J.; Ducos, M.; Vardelle, A.

2001-06-01

The high power plasma torch (PlazJet) can be used to spray refractory ceramics with high spray rates and deposition efficiency. It can provide dense and hard coating with high bond strengths. When manufacturing thermal barrier coatings, the PlazJet gun is well adapted to spraying the ceramic top coat but not the MCrAIY materials that are used as bond coat. Arc spraying can compete with plasma spraying for metallic coatings since cored wires can be used to spray alloys and composites. In addition, the high production rate of arc spraying enables a significant decrease in coating cost. This paper discusses the performances of the PlazJet gun, and a twin-wire are spray system, and compares the properties and cost of MCrAIY coatings made with these two processes. For arc spraying, the use of air or nitrogen as atomizing gas is also investigated.

The origin of sea salt in snow on Arctic sea ice and in coastal regions

Directory of Open Access Journals (Sweden)

F. Domine

2004-01-01

Full Text Available Snow, through its trace constituents, can have a major impact on lower tropospheric chemistry, as evidenced by ozone depletion events (ODEs in oceanic polar areas. These ODEs are caused by the chemistry of bromine compounds that originate from sea salt bromide. Bromide may be supplied to the snow surface by upward migration from sea ice, by frost flowers being wind-blown to the snow surface, or by wind-transported aerosol generated by sea spray. We investigate here the relative importance of these processes by analyzing ions in snow near Alert and Ny-Ålesund (Canadian and European high Arctic in winter and spring. Vertical ionic profiles in the snowpack on sea ice are measured to test upward migration of sea salt ions and to seek evidence for ion fractionation processes. Time series of the ionic composition of surface snow layers are investigated to quantify wind-transported ions. Upward migration of unfractionated sea salt to heights of at least 17cm was observed in winter snow, leading to Cl- concentration of several hundred µM. Upward migration thus has the potential to supply ions to surface snow layers. Time series show that wind can deposit aerosols to the top few cm of the snow, leading also to Cl- concentrations of several hundred µM, so that both diffusion from sea ice and wind transport can significantly contribute ions to snow. At Ny-Ålesund, sea salt transported by wind was unfractionated, implying that it comes from sea spray rather than frost flowers. Estimations based on our results suggest that the marine snowpack contains about 10 times more Na+ than the frost flowers, so that both the marine snowpack and frost flowers need to be considered as sea salt sources. Our data suggest that ozone depletion chemistry can significantly enhance the Br- content of snow. We speculate that this can also take place in coastal regions and contribute to propagate ODEs inland. Finally, we stress the need to measure snow physical parameters

Research on backfilling and sealing of Rooms and Galleries in a repository in salt

International Nuclear Information System (INIS)

Glaess, F.; Kappei, G.; Schmidt, M.W.; Schwieger, K; Starke, C.; Taubert, E.; Wallmueller, R.; Walter, F.

1992-01-01

The multibarrier concept for the final disposal of radioactive wastes comprises backfilling and sealing of the mine in order to guarantee a safe enclosure of the waste. To provide for these properties, soil mechanical laboratory as well as geotechnical in situ measurements were carried out at the Asse mine. The soil mechanical investigations were performed on salt grit and precompacted backfilling material of different grain-size distribution and clay admixtures. They showed a significant dependence upon permeability and compression velocity of the type and quantity of clay used. A favourable grain-size distribution of the salt results in an acceleration of its compaction ability. Besides the investigation on a laboratory scale, first conclusions were obtained on the long-term in situ behaviour of backfilled chambers and seals and their corresponding geomechanical interaction with the surrounding rock. The geotechnical in situ stress and deformation measurements in an approximately 27.000 m 3 large chamber have so far shown no supporting effect against the surrounding rock four years after backfilling. A compaction of up to 3% of the backfill was registered. In situ measurements as well as laboratory tests on drilling cores from 60 years old backfill showed porosities of approximately 7% and a compaction effect of the backfill from the wall, decreasing towards the centre of the chamber due to the converging rock. 108 figs., 8 refs., 24 tabs

Multi-zone modeling of Diesel engine fuel spray development with vegetable oil, bio-diesel or Diesel fuels

International Nuclear Information System (INIS)

Rakopoulos, C.D.; Antonopoulos, K.A.; Rakopoulos, D.C.

2006-01-01

This work presents a model of fuel sprays development in the cylinders of Diesel engines that is two-dimensional, multi-zone, with the issuing jet (from the nozzle) divided into several discrete volumes, called 'zones', formed along the direction of the fuel injection as well as across it. The model follows each zone, with its own time history, as the spray penetrates into the swirling air environment of the combustion chamber before and after wall impingement. After the jet break up time, a group of droplets is generated in each zone, with the model following their motion during heating, evaporation and mixing with the in-cylinder air. The model is applied for the interesting case of using vegetable oils or their derived bio-diesels as fuels, which recently are considered as promising alternatives to petroleum distillates since they are derived from biological sources. Although there are numerous experimental studies that show curtailment of the emitted smoke with possible increase of the emitted NO x against the use of Diesel fuel, there is an apparent scarcity of theoretical models scrutinizing the formation mechanisms of combustion generated emissions when using these biologically derived fuels. Thus, in the present work, a theoretical detailed model of spray formation is developed that is limited to the related investigation of the physical processes by decoupling it from the chemical effects after combustion initiation. The analysis results show how the widely differing physical properties of these fuels, against the normal Diesel fuel, affect greatly the spray formation and consequently the combustion mechanism and the related emissions

ROTARY SPRAY DUSTER

Directory of Open Access Journals (Sweden)

E. S. Nechaeva

2013-01-01

Full Text Available Results of researches of hydraulic resistance, ablation of splashes and efficiency of dedusting in the rotor spray dust collector are given. Influence of frequency of rotation of the spray, the specified speed of gas and diameter of spattering holes on hydraulic resistance, size ablation of splashes and efficiency of a dedusting the device by diameter 0,25 m is investigated. As model liquid water is used. Results of mathematical processing are presented.

Hot Corrosion of Yttrium Stabilized Zirconia Coatings Deposited by Air Plasma Spray on a Nickel-Based Superalloy

Science.gov (United States)

Vallejo, N. Diaz; Sanchez, O.; Caicedo, J. C.; Aperador, W.; Zambrano, G.

In this research, the electrochemical impedance spectroscopy (EIS) and Tafel analysis were utilized to study the hot corrosion performance at 700∘C of air plasma-sprayed (APS) yttria-stabilized zirconia (YSZ) coatings with a NiCrAlY bond coat grown by high velocity oxygen fuel spraying (HVOF), deposited on an INCONEL 625 substrate, in contact with corrosive solids salts as vanadium pentoxide V2O5 and sodium sulfate Na2SO4. The EIS data were interpreted based on proposed equivalent electrical circuits using a suitable fitting procedure performed with Echem AnalystTM Software. Phase transformations and microstructural development were examined using X-ray diffraction (XRD), with Rietveld refinement for quantitative phase analysis, scanning electron microscopy (SEM) was used to determinate the coating morphology and corrosion products. The XRD analysis indicated that the reaction between sodium vanadate (NaVO3) and yttrium oxide (Y2O3) produces yttrium vanadate (YVO4) and leads to the transformation from tetragonal to monoclinic zirconia phase.

On the modeling of fuel sprays

Energy Technology Data Exchange (ETDEWEB)

Bergstroem, Christer

1997-12-01

This report concerns on the modelling of fuel sprays in a non-combustible case using an own developed fuel spray code module. The spray code is made as an independent module to simplify the use of different gas flow solvers together with the spray module. This enables the possibility to use different turbulence models. In the report two turbulence models has been used, the standard k-{epsilon} and the LES (Large Eddy Simulation) model. The report presents results obtained from a sensitivity study of both numerical and physical parameters on an evaporating spray under diesel like conditions (light duty diesel engine) with the spray code module attached to a cylindrical gas phase flow solver. The results from the sensitivity analysis showed that these effects were not so pronounced as has been reported. It was suggested that this was due to the `easy` nature of the investigated case, where the flow field could be sufficiently resolved without violating the droplet void fraction criteria and break-up, collision and combustion that may increase the grid spacing sensitivity were not modelled. An investigation was performed to valuate the feasibility of using LES as turbulence model. Calculations of the initial phase of a developing jet were made and it was found that in the initial phase of the spray and the flow structure were similar to that of a spatially developing jet flow, which is in agreement with experimental observations. Results from LES calculations on a developing spray jet was also compared with k-{epsilon} based ones. This result showed that the spray-LES approach captured the transition from a laminar to a turbulent flow field with an increase in turbulent kinetic energy k along the injection direction 45 refs, 37 figs, 2 tabs

Radio-frequency plasma spraying of ceramics

International Nuclear Information System (INIS)

Okada, T.; Hamatani, H.; Yoshida, T.

1989-01-01

This study was aimed at developing a novel spraying process using a radio-frequency (rf) plasma. Experiments of Al 2 O 3 and ZrO 2 - 8 wt% Y 2 O 3 spraying showed that the initial powder size was the most important parameter for depositing dense coatings. The optimum powder sizes of Al 2 O 3 and ZrO 2 - 8 wt% Y 2 O 3 were considered to be around 100 and 80 μm, respectively. The use of such large-size powders compared with those used by conventional dc plasma spraying made it possible to deposit adherent ceramics coatings of 150 to 300 μm on as-rolled SS304 substrates. It was also shown that low particle velocity of about 10 m/s, which is peculiar to rf plasma spraying, was sufficient for particle deformation, though it imposed a severe limitation on the substrate position. These experimental results prove that rf plasma spraying is an effective process and a strong candidate to open new fields of spraying applications

Direct morphological comparison of vacuum plasma sprayed and detonation gun sprayed hydroxyapatite coatings for orthopaedic applications.

Science.gov (United States)

Gledhill, H C; Turner, I G; Doyle, C

1999-02-01

Hydroxyapatite coatings on titanium substrates were produced using two thermal spray techniques vacuum plasma spraying and detonation gun spraying. X-ray diffraction was used to compare crystallinity and residual stresses in the coatings. Porosity was measured using optical microscopy in conjunction with an image analysis system. Scanning electron microscopy and surface roughness measurements were used to characterise the surface morphologies of the coatings. The vacuum plasma sprayed coatings were found to have a lower residual stress, a higher crystallinity and a higher level of porosity than the detonation gun coatings. It is concluded that consideration needs to be given to the significance of such variations within the clinical context.

Investigation and Taguchi Optimization of Microbial Fuel Cell Salt Bridge Dimensional Parameters

Science.gov (United States)

Sarma, Dhrupad; Barua, Parimal Bakul; Dey, Nabendu; Nath, Sumitro; Thakuria, Mrinmay; Mallick, Synthia

2018-01-01

One major problem of two chamber salt bridge microbial fuel cells (MFCs) is the high resistance offered by the salt bridge to anion flow. Many researchers who have studied and optimized various parameters related to salt bridge MFC, have not shed much light on the effect of salt bridge dimensional parameters on the MFC performance. Therefore, the main objective of this research is to investigate the effect of length and cross sectional area of salt bridge and the effect of solar radiation and atmospheric temperature on MFC current output. An experiment has been designed using Taguchi L9 orthogonal array, taking length and cross sectional area of salt bridge as factors having three levels. Nine MFCs were fabricated as per the nine trial conditions. Trials were conducted for 3 days and output current of each of the MFCs along with solar insolation and atmospheric temperature were recorded. Analysis of variance shows that salt bridge length has significant effect both on mean (with 53.90% contribution at 95% CL) and variance (with 56.46% contribution at 87% CL), whereas the effect of cross sectional area of the salt bridge and the interaction of these two factors is significant on mean only (with 95% CL). Optimum combination was found at 260 mm salt bridge length and 506.7 mm2 cross sectional area with 4.75 mA of mean output current. The temperature and solar insolation data when correlated with each of the MFCs average output current, revealed that both external factors have significant impact on MFC current output but the correlation coefficient varies from MFC to MFC depending on salt bridge dimensional parameters.

Spray drying of poorly soluble drugs from aqueous arginine solution.

Science.gov (United States)

Ojarinta, Rami; Lerminiaux, Louise; Laitinen, Riikka

2017-10-30

Co-amorphous drug-amino acid mixtures have shown potential for improving the solid-state stability and dissolution behavior of amorphous drugs. In previous studies, however these mixtures have been produced mainly with small-scale preparation methods, or with methods that have required the use of organic solvents or other dissolution enhancers. In the present study, co-amorphous ibuprofen-arginine and indomethacin-arginine mixtures were spray dried from water. The mixtures were prepared at two drug-arginine molar ratios (1:1 and 1:2). The properties of the prepared mixtures were investigated with differential scanning calorimetry, X-ray powder diffractometry, Fourier-transform infrared spectroscopy and a 24h, non-sink, dissolution study. All mixtures exhibited a single glass transition temperature (T g ), evidence of the formation of homogenous single-phase systems. Fourier transform infrared spectroscopy revealed strong interactions (mainly salt formation) that account for the positive deviation between measured and estimated T g values. No crystallization was observed during a 1-year stability study in either 1:1 or 1:2 mixtures, but in the presence of moisture, handling difficulties were encountered. The formation of co-amorphous salts led to improved dissolution characteristics when compared to the corresponding physical mixtures or to pure crystalline drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

Experimental characterization of gasoline sprays under highly evaporating conditions

Science.gov (United States)

Khan, Muhammad Mahabat; Sheikh, Nadeem Ahmed; Khalid, Azfar; Lughmani, Waqas Akbar

2018-05-01

An experimental investigation of multistream gasoline sprays under highly evaporating conditions is carried out in this paper. Temperature increase of fuel and low engine pressure could lead to flash boiling. The spray shape is normally modified significantly under flash boiling conditions. The spray plumes expansion along with reduction in the axial momentum causes the jets to merge and creates a low-pressure area below the injector's nozzle. These effects initiate the collapse of spray cone and lead to the formation of a single jet plume or a big cluster like structure. The collapsing sprays reduces exposed surface and therefore they last longer and subsequently penetrate more. Spray plume momentum increase, jet plume reduction and spray target widening could delay or prevent the closure condition and limit the penetration (delayed formation of the cluster promotes evaporation). These spray characteristics are investigated experimentally using shadowgraphy, for five and six hole injectors, under various boundary conditions. Six hole injectors produce more collapsing sprays in comparison to five hole injector due to enhanced jet to jet interactions. The spray collapse tendency reduces with increase in injection pressure due high axial momentum of spray plumes. The spray evaporation rates of five hole injector are observed to be higher than six hole injectors. Larger spray cone angles of the six hole injectors promote less penetrating and less collapsing sprays.

Hot corrosion behavior of nanostructured Gd2O3 doped YSZ thermal barrier coating in presence of Na2SO4 + V2O5 molten salts

Directory of Open Access Journals (Sweden)

Yixiong Wang

2017-08-01

Full Text Available Nickel-based superalloy DZ125 was first sprayed with a NiCrAlY bond coat and followed with a nanostructured 2 mol% Gd2O3−4.5 mol% Y2O3-ZrO2 (2GdYSZ topcoat using air plasma spraying (APS. Hot corrosion behavior of the as-sprayed thermal barrier coatings (TBCs were investigated in the presence of 50 wt% Na2SO4 + 50 wt% V2O5 as the corrosive molten salt at 900 °C for 100 h. The analysis results indicate that Gd doped YVO4 and m-ZrO2 crystals were formed as corrosion products due to the reaction of the corrosive salts with stabilizers (Y2O3, Gd2O3 of zirconia. Cross-section morphology shows that a thin layer called TGO was formed at the bond coat/topcoat interface. After hot corrosion test, the proportion of m-ZrO2 phase in nanostructured 2GdYSZ coating is lower than that of nano-YSZ coating. The result reveals that nanostructured 2GdYSZ coating exhibits a better hot corrosion resistance than nano-YSZ coating.

Cold spray nozzle design

Science.gov (United States)

Haynes, Jeffrey D [Stuart, FL; Sanders, Stuart A [Palm Beach Gardens, FL

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.

Study of Multi-Function Micro-Plasma Spraying Technology

International Nuclear Information System (INIS)

Wang Liuying; Wang Hangong; Hua Shaochun; Cao Xiaoping

2007-01-01

A multi-functional micro-arc plasma spraying system was developed according to aerodynamics and plasma spray theory. The soft switch IGBT (Insulated Gate Bipolar Transistor) invert technique, micro-computer control technique, convergent-divergent nozzle structure and axial powder feeding techniques have been adopted in the design of the micro-arc plasma spraying system. It is not only characterized by a small volume, a light weight, highly accurate control, high deposition efficiency and high reliability, but also has multi-functions in plasma spraying, welding and quenching. The experimental results showed that the system can produce a supersonic flame at a low power, spray Al 2 O 3 particles at an average speed up to 430 m/s, and make nanostructured AT13 coatings with an average bonding strength of 42.7 MPa. Compared to conventional 9M plasma spraying with a higher power, the coatings with almost the same properties as those by conventional plasma spray can be deposited by multi-functional micro-arc plasma spraying with a lower power plasma arc due to an improved power supply design, spray gun structure and powder feeding method. Moreover, this system is suitable for working with thin parts and undertaking on site repairs, and as a result, the application of plasma spraying will be greatly extended

Study on Spray Characteristics and Spray Droplets Dynamic Behavior of Diesel Engine Fueled by Rapeseed Oil

Directory of Open Access Journals (Sweden)

Sapit Azwan

2014-07-01

Full Text Available Fuel-air mixing is important process in diesel combustion. It directly affects the combustion and emission of diesel engine. Biomass fuel needs great help to atomize because the fuel has high viscosity and high distillation temperature. This study investigates the atomization characteristics and droplet dynamic behaviors of diesel engine spray fueled by rapeseed oil (RO. Optical observation of RO spray was carried out using shadowgraph photography technique. Single nano-spark photography technique was used to study the characteristics of the rapeseed oil spray while dual nano-spark shadowgraph technique was used to study the spray droplet behavior. The results show that RO has very poor atomization due to the high viscosity nature of the fuel. This is in agreement with the results from spray droplet dynamic behavior studies that shows due to the high viscosity, the droplets are large in size and travel downward, with very little influence of entrainment effect due to its large kinematic energy.

Characteristics of combustion flame sprayed nickel aluminum using a Coanda Assisted Spray Manipulation collar for off-normal deposits

Science.gov (United States)

Archibald, Reid S.

A novel flame spray collar called the Coanda Assisted Spray Manipulation collar (CSM) has been tested for use on the Sulzer Metco 5P II combustion flame spray gun. A comparison study of the stock nozzle and the CSM has been performed by evaluating the porosity, surface roughness, microhardness, tensile strength and microscopy of normal and off-normal sprayed NiAl deposits. The use of the CSM collar resulted in the need to position the sprayed coupons closer to the gun, which in turn affected the particle impact energy and particle temperatures of the NiAl powder. For the CSM, porosities had a larger scatterband, surface roughness was comparably the same, microhardness was lower, and tensile strength was higher. The microscopy analysis revealed a greater presence of unmelted particles and steeper intersplat boundaries for the CSM. For both processes, the porosity and surface roughness increased and the microhardness decreased as the spray angle decreased.

The impact of high-salt exposure on cardiovascular development in the early chick embryo.

Science.gov (United States)

Wang, Guang; Zhang, Nuan; Wei, Yi-Fan; Jin, Yi-Mei; Zhang, Shi-Yao; Cheng, Xin; Ma, Zheng-Lai; Zhao, Shu-Zhu; Chen, You-Peng; Chuai, Manli; Hocher, Berthold; Yang, Xuesong

2015-11-01

In this study, we show that high-salt exposure dramatically increases chick mortality during embryo development. As embryonic mortality at early stages mainly results from defects in cardiovascular development, we focused on heart formation and angiogenesis. We found that high-salt exposure enhanced the risk of abnormal heart tube looping and blood congestion in the heart chamber. In the presence of high salt, both ventricular cell proliferation and apoptosis increased. The high osmolarity induced by high salt in the ventricular cardiomyocytes resulted in incomplete differentiation, which might be due to reduced expression of Nkx2.5 and GATA4. Blood vessel density and diameter were suppressed by exposure to high salt in both the yolk sac membrane (YSM) and chorioallantoic membrane models. In addition, high-salt-induced suppression of angiogenesis occurred even at the vasculogenesis stage, as blood island formation was also inhibited by high-salt exposure. At the same time, cell proliferation was repressed and cell apoptosis was enhanced by high-salt exposure in YSM tissue. Moreover, the reduction in expression of HIF2 and FGF2 genes might cause high-salt-suppressed angiogenesis. Interestingly, we show that high-salt exposure causes excess generation of reactive oxygen species (ROS) in the heart and YSM tissues, which could be partially rescued through the addition of antioxidants. In total, our study suggests that excess generation of ROS might play an important role in high-salt-induced defects in heart and angiogenesis. © 2015. Published by The Company of Biologists Ltd.

Development of process data capturing, analysis and controlling for thermal spray techniques - SprayTracker

Science.gov (United States)

Kelber, C.; Marke, S.; Trommler, U.; Rupprecht, C.; Weis, S.

2017-03-01

Thermal spraying processes are becoming increasingly important in high-technology areas, such as automotive engineering and medical technology. The method offers the advantage of a local layer application with different materials and high deposition rates. Challenges in the application of thermal spraying result from the complex interaction of different influencing variables, which can be attributed to the properties of different materials, operating equipment supply, electrical parameters, flow mechanics, plasma physics and automation. In addition, spraying systems are subject to constant wear. Due to the process specification and the high demands on the produced coatings, innovative quality assurance tools are necessary. A central aspect, which has not yet been considered, is the data management in relation to the present measured variables, in particular the spraying system, the handling system, working safety devices and additional measuring sensors. Both the recording of all process-characterizing variables, their linking and evaluation as well as the use of the data for the active process control presuppose a novel, innovative control system (hardware and software) that was to be developed within the scope of the research project. In addition, new measurement methods and sensors are to be developed and qualified in order to improve the process reliability of thermal spraying.

Spray cone angle and air core diameter of hollow cone swirl rocket injector

Directory of Open Access Journals (Sweden)

Ahmad Hussein Abdul Hamid

2011-12-01

Full Text Available ABSTRACT : Fuel injector for liquid rocket is a very critical component since that small difference in its design can dramatically affect the combustion efficiency. The primary function of the injector is to break the fuel up into very small droplets. The smaller droplets are necessary for fast quiet ignition and to establish a flame front close to the injector head, thus shorter combustion chamber is possible to be utilized. This paper presents an experimetal investigation of a mono-propellant hollow cone swirl injector. Several injectors with different configuration were investigated under cold flow test, where water is used as simulation fluid. This investigation reveals that higher injection pressure leads to higher spray cone angle. The effect of injection pressure on spray cone angle is more prominent for injector with least number of tangential ports. Furthermore, it was found that injector with the most number of tangential ports and with the smallest tangential port diameter produces the widest resulting spray. Experimental data also tells that the diameter of an air core that forms inside the swirl chamber is largest for the injector with smallest tangential port diameter and least number of tangential ports.ABSTRAK : Injektor bahan api bagi roket cecair merupakan satu komponen yang amat kritikal memandangkan perbezaan kecil dalam reka bentuknya akan secara langsung mempengaruhi kecekapan pembakaran. Fungsi utama injektor adalah untuk memecahkan bahan api kepada titisan yang amat kecil. Titisan kecil penting untuk pembakaran pantas secara senyap dan untuk mewujudkan satu nyalaan di hadapan, berhampiran dengan kepala injektor, maka kebuk pembakaran yang lebih pendek berkemungkinan dapat digunakan. Kertas kerja ini mebentangkan satu penyelidikan eksperimental sebuah injektor ekabahan dorong geronggang kon pusar. Beberapa injektor dengan konfigurasi berbeza telah dikaji di bawah ujian aliran sejuk, di mana air digunakan sebagai bendalir

The Mobile Chamber

Science.gov (United States)

Scharfstein, Gregory; Cox, Russell

2012-01-01

A document discusses a simulation chamber that represents a shift from the thermal-vacuum chamber stereotype. This innovation, currently in development, combines the capabilities of space simulation chambers, the user-friendliness of modern-day electronics, and the modularity of plug-and-play computing. The Mobile Chamber is a customized test chamber that can be deployed with great ease, and is capable of bringing payloads at temperatures down to 20 K, in high vacuum, and with the desired metrology instruments integrated to the systems control. Flexure plans to lease Mobile Chambers, making them affordable for smaller budgets and available to a larger customer base. A key feature of this design will be an Apple iPad-like user interface that allows someone with minimal training to control the environment inside the chamber, and to simulate the required extreme environments. The feedback of thermal, pressure, and other measurements is delivered in a 3D CAD model of the chamber's payload and support hardware. This GUI will provide the user with a better understanding of the payload than any existing thermal-vacuum system.

Fundamental Study on the Effect of Spray Parameters on Characteristics of P3HT:PCBM Active Layers Made by Spray Coating

Directory of Open Access Journals (Sweden)

Yu Xie

2015-08-01

Full Text Available This paper is an attempt to elucidate the effects of the important spray characteristics on the surface morphology and light absorbance of spray-on P3HT:PCBM thin-films, used as an active layer in polymer solar cells (PSCs. Spray coating or deposition is a viable scalable technique for the large-scale, fast, and low-cost fabrication of solution-processed solar cells, and has been widely used for device fabrication, although the fundamental understanding of the underlying and controlling parameters, such as spray characteristics, droplet dynamics, and surface wettability, is still limited, making the results on device fabrication not reproducible and unreliable. In this paper, following the conventional PSC architecture, a PEDOT:PSS layer is first spin-coated on glass substrates, followed by the deposition of P3HT:PCBM using an automatic ultrasonic spray coating system, with a movable nozzle tip, to mimic an industrial manufacturing process. To gain insight, the effects of the spray carrier air pressure, the number of spray passes, the precursor flow rate, and precursor concentration are studied on the surface topography and light absorbance spectra of the spray-on films. Among the results, it is found that despite the high roughness of spray-on films, the light absorbance of the film is satisfactory. It is also found that the absorbance of spray-on films is a linear function of the number of spray passes or deposition layers, based on which an effective film thickness is defined for rough spray-on films. The effective thickness of a rough spray-on P3HT:PCBM film was found to be one-quarter of that of a flat film predicted by a simple mass balance.

Fine Sprays for Disinfection within Healthcare

Directory of Open Access Journals (Sweden)

G Nasr

2016-09-01

Full Text Available Problems exist worldwide with Hospital Acquired Infections (HAI's. The Spray Research Group (SRG have been working with relevant industries in developing a product which can provide a delivery system for treatment chemicals for surfaces, including the design and testing of a novel Spill-Return Atomiser (SRA for this purpose. A comprehensive description of this atomiser has already been given. This paper reports on a new application of this atomiser and discusses the problem of spray coating for disinfection that has been considered very little in previous work. The related spray coating performance tests in developing the product are thus provided. The experimental work includes determining the required spray duration and the coverage area produced by different sprays, including the analysis of the effects of atomiser positions, configurations, and the required number of atomisers. Comparison is made with the efficacy of an ultrasonic gas atomiser that is currently used for this purpose. The investigation has found that the utilisation of fine sprays (10μm>D32>25μm at high liquid pressure (<12MPa and low flow rates (<0.3 l/min is suitable for surface disinfection in healthcare applications (i.e. MRSA, VRSA etc.

Salt stress induces differential regulation of the phenylpropanoid pathway in Olea europaea cultivars Frantoio (salt-tolerant) and Leccino (salt-sensitive).

Science.gov (United States)

Rossi, Lorenzo; Borghi, Monica; Francini, Alessandra; Lin, Xiuli; Xie, De-Yu; Sebastiani, Luca

2016-10-01

Olive tree (Olea europaea L.) is an important crop in the Mediterranean Basin where drought and salinity are two of the main factors affecting plant productivity. Despite several studies have reported different responses of various olive tree cultivars to salt stress, the mechanisms that convey tolerance and sensitivity remain largely unknown. To investigate this issue, potted olive plants of Leccino (salt-sensitive) and Frantoio (salt-tolerant) cultivars were grown in a phytotron chamber and treated with 0, 60 and 120mM NaCl. After forty days of treatment, growth analysis was performed and the concentration of sodium in root, stem and leaves was measured by atomic absorption spectroscopy. Phenolic compounds were extracted using methanol, hydrolyzed with butanol-HCl, and quercetin and kaempferol quantified via high performance liquid-chromatography-electrospray-mass spectrometry (HPLC-ESI-MS) and HPLC-q-Time of Flight-MS analyses. In addition, the transcripts levels of five key genes of the phenylpropanoid pathway were measured by quantitative Real-Time PCR. The results of this study corroborate the previous observations, which showed that Frantoio and Leccino differ in allocating sodium in root and leaves. This study also revealed that phenolic compounds remain stable or are strongly depleted under long-time treatment with sodium in Leccino, despite a strong up-regulation of key genes of the phenylpropanoid pathway was observed. Frantoio instead, showed a less intense up-regulation of the phenylpropanoid genes but overall higher content of phenolic compounds. These data suggest that Frantoio copes with the toxicity imposed by elevated sodium not only with mechanisms of Na + exclusion, but also promptly allocating effective and adequate antioxidant compounds to more sensitive organs. Copyright © 2016 Elsevier GmbH. All rights reserved.

Investigation of cerium salt/sulfuric acid anodizing technology for 1420 aluminum alloy

Energy Technology Data Exchange (ETDEWEB)

Di Li; Yue Peng Deng; Bao Lan Guo; Guo Qiang Li [Beijing Univ. of Aeronautics and Astronautics (China). Dept. of Mater. Sci. and Eng.

2000-07-01

In this paper, the effect of cerium addition agent on the property of anodized coating of 1420 Al alloy has been studied by corrosion experiment (immersion test and neutral salt spray test), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and measurement of polarization curves. The result show that only pitting could be observed in all corrosion tests while intergranular corrosion and exfoliation corrosion did not appear on 1420 Al-Li alloys. When organic carboxylic acid S or the cerium (IV) salt was added into sulfuric acid anodizing electrolyte separately, there was no significant improvement in corrosion resistance of anodized film. However, in the case of adding them into sulfuric acid anodizing electrolyte together, the corrosion resistance of anodized film increased greatly owing to synergistic effect. The synergistic effect may relate to the formation of cerium-organic carboxylic acid S complex compound and its effects on film growth and film structure. (orig.)

Multiphysics modelling of the spray forming process

International Nuclear Information System (INIS)

Mi, J.; Grant, P.S.; Fritsching, U.; Belkessam, O.; Garmendia, I.; Landaberea, A.

2008-01-01

An integrated, multiphysics numerical model has been developed through the joint efforts of the University of Oxford (UK), University of Bremen (Germany) and Inasmet (Spain) to simulate the spray forming process. The integrated model consisted of four sub-models: (1) an atomization model simulating the fragmentation of a continuous liquid metal stream into droplet spray during gas atomization; (2) a droplet spray model simulating the droplet spray mass and enthalpy evolution in the gas flow field prior to deposition; (3) a droplet deposition model simulating droplet deposition, splashing and re-deposition behavior and the resulting preform shape and heat flow; and (4) a porosity model simulating the porosity distribution inside a spray formed ring preform. The model has been validated against experiments of the spray forming of large diameter IN718 Ni superalloy rings. The modelled preform shape, surface temperature and final porosity distribution showed good agreement with experimental measurements

Water spray interaction with air-steam mixtures under containment spray conditions: comparison of heat and mass transfer modelling with the TOSQAN spray tests

International Nuclear Information System (INIS)

Malet, J.; Lemaitre, P.; Porcheron, E.; Vendel, J.

2005-01-01

Full text of publication follows: During the course of a hypothetical severe accident in a Pressurized Water Reactor (PWR), hydrogen can be produced by the reactor core oxidation and distributed into the reactor containment according to convection flows and water steam wall condensation. In order to mitigate the risk of detonation generated by a high local hydrogen concentration, spray systems are used in the containment. The TOSQAN programme has been created to simulate separate-effect tests representative of typical accidental thermal-hydraulic flow conditions in the reactor containment. The present work concerns the interaction of a water spray, used at the top of the containment in order to reduce the steam partial pressure, with air-steam mixtures. The main phenomena occurring when water spray is used are the mixing induced by spray entrainment and the condensation on droplets. In order to improve the latter phenomena, different levels of modelling can be used. The objective of this paper is to analyze experimental results obtained for water spray interaction with air-steam mixtures using different heat and mass transfer modelling. For this purpose, two modelling issues have been used: the first one is devoted for the determination of the gas thermodynamical properties, and the second one concerns the droplets characterization. In the first one, the gas thermodynamical analysis is performed using depressurization, gas temperature variation and humidity decrease during the spray injection. In this modelling, heat and mass transfer between the spray and the surrounding gas is treated in a global way by energy balance between the total amount of water and the gas. In the second one, droplets characterization is obtained by means of droplet size, temperature and velocities evolutions. In this modelling, the spray is considered as a single droplet falling with an initial velocity. Droplet interactions are neglected. Assessment of these two modelling is performed

Drift chamber

International Nuclear Information System (INIS)

Inagaki, Yosuke

1977-01-01

Drift chamber is becoming an important detector in high energy physics as a precision and fast position detector because of its high spatial resolution and count-rate. The basic principle is that it utilizes the drift at constant speed of electrons ionized along the tracks of charged particles towards the anode wire in the nearly uniform electric field. The method of measuring drift time includes the analog and digital ones. This report describes about the construction of and the application of electric field to the drift chamber, mathematical analysis on the electric field and equipotential curve, derivation of spatial resolution and the factor for its determination, and selection of gas to be used. The performance test of the chamber was carried out using a small test chamber, the collimated β source of Sr-90, and 500 MeV/C electron beam from the 1.3 GeV electron synchrotron in the Institute of Nuclear Study, University of Tokyo. Most chambers to date adopted one dimensional read-out, but it is very advantageous if the two dimensional read-out is feasible with one chamber when the resolution in that direction is low. The typical methods of delay line and charge division for two dimensional read-out are described. The development of digital read-out system is underway, which can process the signal of a large scale drift chamber at high speed. (Wakatsuki, Y.)

Multiple chamber ionization detector

International Nuclear Information System (INIS)

Solomon, E.E.

1980-01-01

A multi-chambered ionisation detector enables the amount of radiation entering each chamber from a single radioactive, eg β, source to be varied by altering the proportion of the source protruding into each chamber. Electrodes define chambers and an extended radioactive source is movable to alter the source length in each chamber. Alternatively, the source is fixed relative to outer electrodes but the central electrode may be adjusted by an attached support altering the chamber dimensions and hence the length of source in each. Also disclosed are a centrally mounted source tiltable towards one or other chamber and a central electrode tiltable to alter chamber dimensions. (U.K.)

Production of amorphous nanoparticles by supersonic spray-drying with a microfluidic nebulator

Science.gov (United States)

Amstad, Esther; Gopinadhan, Manesh; Holtze, Christian; Osuji, Chinedum O.; Brenner, Michael P.; Spaepen, Frans; Weitz, David A.

2015-08-01

Amorphous nanoparticles (a-NPs) have physicochemical properties distinctly different from those of the corresponding bulk crystals; for example, their solubility is much higher. However, many materials have a high propensity to crystallize and are difficult to formulate in an amorphous structure without stabilizers. We fabricated a microfluidic nebulator that can produce amorphous NPs from a wide range of materials, even including pure table salt (NaCl). By using supersonic air flow, the nebulator produces drops that are so small that they dry before crystal nuclei can form. The small size of the resulting spray-dried a-NPs limits the probability of crystal nucleation in any given particle during storage. The kinetic stability of the a-NPs—on the order of months—is advantageous for hydrophobic drug molecules.

Polyurethane spray coating of aluminum wire bonds to prevent corrosion and suppress resonant oscillations

CERN Document Server

INSPIRE-00092738; Kurth, Matthew; Boyd, Rusty

2016-01-01

Unencapsulated aluminum wedge wire bonds are common in particle physics pixel and strip detectors. Industry-favored bulk encapsulation is eschewed due to the range of operating temperatures and radiation. Wire bond failures are a persistent source of tracking-detector failure. Unencapsulated bonds are vulnerable to condensation-induced corrosion, particularly when halides are present. Oscillations from periodic Lorentz forces are documented as another source of wire bond failure. Spray application of polyurethane coatings, performance of polyurethane-coated wire bonds after climate chamber exposure, and resonant properties of polyurethane-coated wire bonds and their resistance to periodic Lorentz forces are under study for use in a future High Luminosity Large Hadron Collider detector such as the ATLAS Inner Tracker upgrade.

Clay mineral association in the salt formation of the Transylvanian Basin and its paleoenvironmental significance

Directory of Open Access Journals (Sweden)

Nicoleta Bican-Bris̡an

2006-04-01

Full Text Available The investigated clay fraction was separated from salt samples recovered from three boreholes located in the Praid salt deposit area. For comparison, samples collected from Turda deposit (Franz Josef adit, the Rudolf and Ghizele chambers and from the salt massif from Sărăţel were also analyzed. The qualitative investigations evidenced a clay minerals association dominated by illite and chlorite accompanied by subordinate amounts of kaolinite, smectite, fibrous clays (sepiolite, palygorskite, and in minor amounts, by 14/14 chlorite/vermiculite and chlorite/smectite interstratifications. A quantitative evaluation (% including a standard graphical representation was performed only for the borehole samples (Praid, according to the vertical distribution. The genetical interpretation of the identified clay minerals association took into account the influence of the sedimentation mechanisms and the climate control on the mineral phases. The environment of formation for the salt in the Transylvanian Basin was defined by the presence of specific climatic factors, also suggested by the palynological investigations.

Structure and Corrosion Behavior of Arc-Sprayed Zn-Al Coatings on Ductile Iron Substrate

Science.gov (United States)

Bonabi, Salar Fatoureh; Ashrafizadeh, Fakhreddin; Sanati, Alireza; Nahvi, Saied Mehran

2018-02-01

In this research, four coatings including pure zinc, pure aluminum, a double-layered coating of zinc and aluminum, and a coating produced by simultaneous deposition of zinc and aluminum were deposited on a cast iron substrate using electric arc-spraying technique. The coatings were characterized by XRD, SEM and EDS map and spot analyses. Adhesion strength of the coatings was evaluated by three-point bending tests, where double-layered coating indicated the lowest bending angle among the specimens, with detection of cracks at the coating-substrate interface. Coatings produced by simultaneous deposition of zinc and aluminum possessed a relatively uniform distribution of both metals. In order to evaluate the corrosion behavior of the coatings, cyclic polarization and salt spray tests were conducted. Accordingly, pure aluminum coating showed susceptibility to pitting corrosion and other coatings underwent uniform corrosion. For double-layered coating, SEM micrographs revealed zinc corrosion products as flaky particles in the pores formed by pitting on the surface, an indication of penetration of corrosion products from the lower layer (zinc) to the top layer (aluminum). All coatings experienced higher negative corrosion potentials than the iron substrate, indicative of their sacrificial behavior.

Doriot Climatic Chambers

Data.gov (United States)

Federal Laboratory Consortium — The Doriot Climatic Chambers are two, 60-feet long, 11-feet high, 15-feet wide chambers that are owned and operated by NSRDEC. The Doriot Climatic Chambers are among...

Spray casting project final report

International Nuclear Information System (INIS)

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

Thermally sprayed coatings: Aluminum on lead

International Nuclear Information System (INIS)

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

1999-01-01

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%

Ionization chamber

International Nuclear Information System (INIS)

1977-01-01

An improved ionization chamber type X-ray detector comprises a heavy gas at high pressure disposed between an anode and a cathode. An open grid structure is placed next to the anode and is maintained at a voltage intermediate between the cathode and anode potentials. The electric field which is produced by positive ions drifting towards the cathode is thus shielded from the anode. Current measuring circuits connected to the anode are, therefore, responsive only to electron current flow within the chamber and the recovery time of the chamber is shortened. The grid structure also serves to shield the anode from electrical currents which might otherwise be induced by mechanical vibrations in the ionization chamber structure

Water spray ventilator system for continuous mining machines

Science.gov (United States)

Page, Steven J.; Mal, Thomas

1995-01-01

The invention relates to a water spray ventilator system mounted on a continuous mining machine to streamline airflow and provide effective face ventilation of both respirable dust and methane in underground coal mines. This system has two side spray nozzles mounted one on each side of the mining machine and six spray nozzles disposed on a manifold mounted to the underside of the machine boom. The six spray nozzles are angularly and laterally oriented on the manifold so as to provide non-overlapping spray patterns along the length of the cutter drum.

A new method for spray deposit assessment

Science.gov (United States)

Chester M. Himel; Leland Vaughn; Raymond P. Miskus; Arthur D. Moore

1965-01-01

Solid fluorescent particles suspended in a spray liquid are distributed in direct proportion to the size of the spray droplets. Use of solid fluorescent particles is the basis of a new method for visual recognition of the size and number of droplets impinging on target and nontarget portions of sprayed areas.

A simplified model of aerosol removal by containment sprays

Energy Technology Data Exchange (ETDEWEB)

Powers, D.A. (Sandia National Labs., Albuquerque, NM (United States)); Burson, S.B. (Nuclear Regulatory Commission, Washington, DC (United States). Div. of Safety Issue Resolution)

1993-06-01

Spray systems in nuclear reactor containments are described. The scrubbing of aerosols from containment atmospheres by spray droplets is discussed. Uncertainties are identified in the prediction of spray performance when the sprays are used as a means for decontaminating containment atmospheres. A mechanistic model based on current knowledge of the physical phenomena involved in spray performance is developed. With this model, a quantitative uncertainty analysis of spray performance is conducted using a Monte Carlo method to sample 20 uncertain quantities related to phenomena of spray droplet behavior as well as the initial and boundary conditions expected to be associated with severe reactor accidents. Results of the uncertainty analysis are used to construct simplified expressions for spray decontamination coefficients. Two variables that affect aerosol capture by water droplets are not treated as uncertain; they are (1) [open quote]Q[close quote], spray water flux into the containment, and (2) [open quote]H[close quote], the total fall distance of spray droplets. The choice of values of these variables is left to the user since they are plant and accident specific. Also, they can usually be ascertained with some degree of certainty. The spray decontamination coefficients are found to be sufficiently dependent on the extent of decontamination that the fraction of the initial aerosol remaining in the atmosphere, m[sub f], is explicitly treated in the simplified expressions. The simplified expressions for the spray decontamination coefficient are given. Parametric values for these expressions are found for median, 10 percentile, and 90 percentile values in the uncertainty distribution for the spray decontamination coefficient. Examples are given to illustrate the utility of the simplified expressions to predict spray decontamination of an aerosol-laden atmosphere.

Foliar spray with vermiwash modifies the Arbuscular mycorrhizal dependency and nutrient stoichiometry of Bhut Jolokia (Capsicum assamicum.

Directory of Open Access Journals (Sweden)

Mohammad Haneef Khan

Full Text Available Vermiwash (VW, a liquid extract obtained from vermicomposting beds, is used as an organic fertilizer for crop plants. The current study investigated the effect of a vermiwash foliar spray on the response of bhut jolokia (Capsicum assamicum exposed to two different arbuscular mycorrhizal fungi (AMF: Rhizophagus irregularis, RI and G. mosseae, GM in acidic soil under naturally ventilated greenhouse conditions. The VW spray significantly influenced the growth of plants receiving the dual treatment of AMF+VW. Plant growth was more prominent in the GM+VW treatment group than that in the RI+VW treatment group. The plant-AMF interactions in relation to growth and nutrient requirements were also significantly influenced by the application of VW. Interestingly, the VW treatment appeared to contribute more N to plants when compared to that under the AMF treatment, which led to changes in the C:N:P stoichiometry in plant shoots. Furthermore, the increased potassium dependency, as observed in the case of the dual treatments, suggests the significance of such treatments for improving crop conditions under salt stress. Overall, our study shows that the VW foliar spray modifies the response of a crop to inoculations of different AMF with regard to growth and nutrient utilization, which has implications for the selection of an efficient combination of nutrient source for improving crop growth.

Foliar Spray with Vermiwash Modifies the Arbuscular Mycorrhizal Dependency and Nutrient Stoichiometry of Bhut Jolokia (Capsicum assamicum)

Science.gov (United States)

Gupta, Rajeev; Veer, Vijay; Singh, Lokendra; Kalita, Mohan C.

2014-01-01

Vermiwash (VW), a liquid extract obtained from vermicomposting beds, is used as an organic fertilizer for crop plants. The current study investigated the effect of a vermiwash foliar spray on the response of bhut jolokia (Capsicum assamicum) exposed to two different arbuscular mycorrhizal fungi (AMF: Rhizophagus irregularis, RI and G. mosseae, GM) in acidic soil under naturally ventilated greenhouse conditions. The VW spray significantly influenced the growth of plants receiving the dual treatment of AMF+VW. Plant growth was more prominent in the GM+VW treatment group than that in the RI+VW treatment group. The plant-AMF interactions in relation to growth and nutrient requirements were also significantly influenced by the application of VW. Interestingly, the VW treatment appeared to contribute more N to plants when compared to that under the AMF treatment, which led to changes in the C:N:P stoichiometry in plant shoots. Furthermore, the increased potassium dependency, as observed in the case of the dual treatments, suggests the significance of such treatments for improving crop conditions under salt stress. Overall, our study shows that the VW foliar spray modifies the response of a crop to inoculations of different AMF with regard to growth and nutrient utilization, which has implications for the selection of an efficient combination of nutrient source for improving crop growth. PMID:24651577

Effect of spray volume on the deposition, viability and infectivity of entomopathogenic nematodes in a foliar spray on vegetables.

Science.gov (United States)

Brusselman, Eva; Beck, Bert; Pollet, Sabien; Temmerman, Femke; Spanoghe, Pieter; Moens, Maurice; Nuyttens, David

2012-10-01

Spray volume can influence the amount of free water on the leaf surface and subsequently the ability of entomopathogenic nematodes (EPNs) to move. In this study, an investigation was made of the effect of spray volume (548, 730 and 1095 L ha(-1) ) on the deposition, viability and infectivity of EPNs against Galleria mellonella on savoy cabbage, cauliflower and leek. Increasing spray volume decreased nematode deposition on 7.1 cm2 leek leaf discs at a 15° angle with the spray nozzle. Although the number of living nematodes observed on leek after 240 min of exposure was not significantly different between the low-volume application (548 L ha(-1) ) and the high-volume application (1095 L ha(-1) ), a greater infectivity was obtained in the latter application. The higher number of droplets deposited on the leek discs in the high-volume application may have stimulated nematode movement. No significant effect of spray volume was observed on the relative deposition of Steinernema carpocapsae on the bottom side of cauliflower and savoy cabbage leaf discs. In spite of the low S. carpocapsae deposition on the bottom side of the savoy cabbage discs, high infectivity was obtained against G. mellonella. Using the lowest spray volume on savoy cabbage, infectivity decreased with increasing exposure time, while infectivity was not affected by exposure time when a spray volume of 730 L ha(-1) or more was used. Spray volume is an important application parameter, as it affects nematode infectivity. Future research should investigate the effect of spray volume in the field and its influence on the effect of adjuvants. Copyright © 2012 Society of Chemical Industry.

Albendazole Microparticles Prepared by Spray Drying Technique ...

African Journals Online (AJOL)

Purpose: To enhance the dissolution of albendazole (ABZ) using spray-drying technique. Method: ABZ binary mixtures with Kollicoat IR® (KL) and polyvinyl pyrrolidone (PVP) in various drug to polymer ratios (1: 1, 1: 2 and 1; 4) were prepared by spray-drying. The spray-dried particles were characterized for particle shape, ...

Quality characteristic of spray-drying egg white powders.

Science.gov (United States)

Ma, Shuang; Zhao, Songning; Zhang, Yan; Yu, Yiding; Liu, Jingbo; Xu, Menglei

2013-10-01

Spray drying is a useful method for developing egg process and utilization. The objective of this study was to evaluate effects on spray drying condition of egg white. The optimized conditions were spraying flow 22 mL/min, feeding temperature 39.8 °C and inlet-air temperature 178.2 °C. Results of sulfydryl (SH) groups measurement indicated conformation structure have changed resulting in protein molecule occur S-S crosslinking phenomenon when heating. It led to free SH content decreased during spray drying process. There was almost no change of differential scanning calorimetry between fresh egg white and spray-drying egg white powder (EWP). For a given protein, the apparent SH reactivity is in turn influenced by the physico-chemical characteristics of the reactant. The phenomenon illustrated the thermal denaturation of these proteins was unrelated to their free SH contents. Color measurement was used to study browning level. EWP in optimized conditions revealed insignificant brown stain. Swelling capacity and scanning electron micrograph both proved well quality characteristic of spray-drying EWP. Results suggested spray drying under the optimized conditions present suitable and alternative method for egg processing industrial implementation. Egg food industrialization needs new drying method to extend shelf-life. The purpose of the study was to provide optimal process of healthy and nutritional instant spray-drying EWP and study quality characteristic of spray-drying EWP.

Spray coating of microcontainers with eudragit using ferromagnetic shadow masks for controlled oral release of poorly water soluble drugs

DEFF Research Database (Denmark)

Nielsen, Line Hagner; Keller, Stephan Sylvest; Boisen, Anja

2013-01-01

(weak acid). The cavity of the drug-filled microcontainers were spray coated with a 2 wt% solution of either Eudragit S-100 (soluble below pH 5) or Eudragit L-100 (soluble above pH 6) in isopropanol. The spray coating process was performed using ferromagnetic shadow masks (380 μm) allowing for magnetic...... clamping to the substrate and therefore precise deposition of the polymer on the microcontainers to form a lid. The release of cinnarizine and amorphous furosemide salt from the coated microcontainers was performed in fasted biorelevant gastric (pH 1.6) and intestinal media (pH 6.5), respectively. RESULTS......: By use of the ferromagnetic shadow masks it was possible to deposit the Eudragit precisely and therefore possible to form a lid of the cavity of the microcontainers. The thickness of the Eudragit layer on the cavity of the microcontainers was approximately 8-10 μm for both types of Eudragit...

Spray drying of beryllium oxide powder

International Nuclear Information System (INIS)

Sepulveda, J.L.; Kahler, D.A.

1991-01-01

Forming of beryllia ceramics through dry pressing requires the agglomeration of the powder through spray drying. To produce high quality fired ceramics it is necessary to disperse/grind the primary powder prior to binder addition. Size reduction of the powder is accomplished using an aqueous system in Vibro-Energy mills (VEM) charged with beryllia media to minimize contamination. Two VEM mills of different size were used to characterize the grinding operation. Details of the grinding kinetics are described within the context of the Macroscopic Population Balance Model approach. Spray drying of the ceramic slurry was accomplished with both a centrifugal atomizer and a two fluid nozzle atomizer. Two different spray dryers were used. Important operating parameters affecting the size distribution of the spray dried powder are discussed

LSPRAY-V: A Lagrangian Spray Module

Science.gov (United States)

Raju, M. S.

2015-01-01

LSPRAY-V is a Lagrangian spray solver developed for application with unstructured grids and massively parallel computers. It is mainly designed to predict the flow, thermal and transport properties of a rapidly vaporizing spray encountered over a wide range of operating conditions in modern aircraft engine development. It could easily be coupled with any existing gas-phase flow and/or Monte Carlo Probability Density Function (PDF) solvers. 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. With the development of LSPRAY-V, we have advanced the state-of-the-art in spray computations in several important ways.

High-Performance Molybdenum Coating by Wire–HVOF Thermal Spray Process

Science.gov (United States)

Tailor, Satish; Modi, Ankur; Modi, S. C.

2018-04-01

Coating deposition on many industrial components with good microstructural, mechanical properties, and better wear resistance is always a challenge for the thermal spray community. A number of thermal spray methods are used to develop such promising coatings for many industrial applications, viz. arc spray, flame spray, plasma, and HVOF. All these processes have their own limitations to achieve porous free, very dense, high-performance wear-resistant coatings. In this work, an attempt has been made to overcome this limitation. Molybdenum coatings were deposited on low-carbon steel substrates using wire-high-velocity oxy-fuel (W-HVOF; WH) thermal spray system (trade name HIJET 9610®). For a comparison, Mo coatings were also fabricated by arc spray, flame spray, plasma spray, and powder-HVOF processes. As-sprayed coatings were analyzed using x-ray diffraction, scanning electron microscopy for phase, and microstructural analysis, respectively. Coating microhardness, surface roughness, and porosity were also measured. Adhesion strength and wear tests were conducted to determine the mechanical and wear properties of the as-sprayed coatings. Results show that the coatings deposited by W-HVOF have better performance in terms of microstructural, mechanical, and wear resistance properties, in comparison with available thermal spray process (flame spray and plasma spray).

A Piston Geometry and Nozzle Spray Angle Investigation in a DI Diesel Engine by Quantifying the Air-Fuel Mixture

Directory of Open Access Journals (Sweden)

Pavlos Dimitriou

2015-03-01

Full Text Available Low temperature diesel combustion has been widely investigated over the last few years for reducing in-cylinder emissions of Direct Injection (DI diesel engines without sacrificing efficiency and fuel consumption. The spatial distribution of the fuel within the combustion chamber and the air-fuel mixing quality are the key factors affecting temperature generation within the cylinder. Avoiding fuel rich areas within the cylinder can significantly reduce the local high temperatures resulting in low NOx formation. This paper investigates the effects of the combustion chamber geometry and spray angle on the air-fuel mixing and emissions formation of a DI diesel engine. A new quantitative factor measuring the air-fuel mixing quality has been adopted in order to analyze and compare air-fuel mixing quality for different piston geometries. The results have shown that pistons with a narrow entrance and a deep combustion re-entrant chamber benefit from increased air-fuel mixtures due to the significantly higher swirl generated within the cylinder. However, the improved air-fuel mixing does not consequently lead to a reduced NOx generation, which is highly affected by the combustion efficiency of the engine.

Characterization of the full cone pressure swirl spray nozzles for the nuclear reactor containment spray system

Energy Technology Data Exchange (ETDEWEB)

Jain, Manish [Department of Mechanical Engineering, I.I.T., Bombay, Powai, Mumbai (India); John, Benny [Nuclear Power Corporation of India Limited, Mumbai (India); Iyer, K.N. [Department of Mechanical Engineering, I.I.T., Bombay, Powai, Mumbai (India); Prabhu, S.V., E-mail: svprabhu@iitb.ac.in [Department of Mechanical Engineering, I.I.T., Bombay, Powai, Mumbai (India)

2014-07-01

Highlights: • Full cone spray pressure swirl nozzle with X-Vane is studied. • Laser illuminated imaging technique is used. • Correlations for coefficient of discharge, spray cone angle and SMD are suggested. • Droplet size and mass fraction distribution is measured. • Inviscid theory predicts the coefficient of discharge. - Abstract: The objective of the present study is to characterize a full cone pressure swirl nozzle for the Containment Spray System (CSS) of Indian Pressurized heavy Water reactors (IPHWR). The influence of Reynolds number and geometric parameters on the coefficient of discharge, spray cone angle, mass flux density distribution, droplet size distribution, Sauter mean diameter (SMD is studied for full cone pressure swirl full cone nozzles. The nozzles of orifice diameter range from 1.3 to 7.2 mm are studied. Experiments are conducted with water at room temperature as the working medium. The nozzles are operated with the pressure ranging from 1 to 8 bar. The measurements of the drop size distributions are performed with laser illuminated imaging technique. The spray cone-angle of the full cone nozzles is measured by the evaluation of images recorded with a camera using IMAGE J software. Correlations for coefficient of discharge, spray cone angle and Sauter mean diameter are suggested on the basis of the experimental results. Rosin–Rammler model and Nukiyama–Tanasawa distributions predict the mass fraction distribution reasonably well. However, the droplet size distribution is predicted by Nukiyama-Tanasawa model only.

Open fibre reinforced plastic (FRP) flat plate collector (FPC) and spray network systems for augmenting the evaporation rate of tannery effluent (soak liquor)

International Nuclear Information System (INIS)

Srithar, K.; Mani, A.

2007-01-01

Presently, tanneries in Tamilnadu, India are required to segregate the effluent of soaking and pickling sections from other wastewater streams and send it to shallow solar pans for evaporation to avoid land pollution. A large area of solar pans is required for evaporating the water in the effluent at salt concentration in the range of 4-5%. An experimental study has been made by using fibre reinforced plastic flat plate collector (FRP-FPC) and spray system in a pilot plant with a capacity to handle 5000 l per day, which increases the evaporation rate. After increasing the salt concentration level to near saturation limit, the concentrated liquid was sent to conventional solar pans for its continued evaporation and recovery of salt. In this improved system, the rate of evaporation was found to be 30-40% more than that in the conventional solar pans. The performance is compared with the theoretically simulated performance. (author)

Plasma spraying process of disperse carbides for spraying and facing

International Nuclear Information System (INIS)

Blinkov, I.V.; Vishnevetskaya, I.A.; Kostyukovich, T.G.; Ostapovich, A.O.

1989-01-01

A possibility to metallize carbides in plasma of impulsing capacitor discharge is considered. Powders granulation occurs during plasma spraying process, ceramic core being completely capped. X-ray phase and chemical analyses of coatings did not show considerable changes of carbon content in carbides before and after plasma processing. This distinguishes the process of carbides metallization in impulsing plasma from the similar processing in arc and high-frequency plasma generator. Use of powder composites produced in the impulsing capacitor discharge, for plasma spraying and laser facing permits 2-3 times increasing wear resistance of the surface layer as against the coatings produced from mechanical powders mixtures

Alignment Fixtures For Vacuum-Plasma-Spray Gun

Science.gov (United States)

Woodford, William H.; Mckechnie, Timothy N.; Power, Christopher A.; Daniel, Ronald L., Jr.

1993-01-01

Fixtures for alignment of vacuum-plasma-spray guns built. Each fixture designed to fit specific gun and holds small, battery-powered laser on centerline of gun. Laser beam projects small red dot where centerline intersects surface of workpiece to be sprayed. After laser beam positioned on surface of workpiece, fixture removed from gun and spraying proceeds.

Road salt emissions: A comparison of measurements and modelling using the NORTRIP road dust emission model

Science.gov (United States)

Denby, B. R.; Ketzel, M.; Ellermann, T.; Stojiljkovic, A.; Kupiainen, K.; Niemi, J. V.; Norman, M.; Johansson, C.; Gustafsson, M.; Blomqvist, G.; Janhäll, S.; Sundvor, I.

2016-09-01

De-icing of road surfaces is necessary in many countries during winter to improve vehicle traction. Large amounts of salt, most often sodium chloride, are applied every year. Most of this salt is removed through drainage or traffic spray processes but a certain amount may be suspended, after drying of the road surface, into the air and will contribute to the concentration of particulate matter. Though some measurements of salt concentrations are available near roads, the link between road maintenance salting activities and observed concentrations of salt in ambient air is yet to be quantified. In this study the NORTRIP road dust emission model, which estimates the emissions of both dust and salt from the road surface, is applied at five sites in four Nordic countries for ten separate winter periods where daily mean ambient air measurements of salt concentrations are available. The model is capable of reproducing many of the salt emission episodes, both in time and intensity, but also fails on other occasions. The observed mean concentration of salt in PM10, over all ten datasets, is 4.2 μg/m3 and the modelled mean is 2.8 μg/m3, giving a fractional bias of -0.38. The RMSE of the mean concentrations, over all 10 datasets, is 2.9 μg/m3 with an average R2 of 0.28. The mean concentration of salt is similar to the mean exhaust contribution during the winter periods of 2.6 μg/m3. The contribution of salt to the kerbside winter mean PM10 concentration is estimated to increase by 4.1 ± 3.4 μg/m3 for every kg/m2 of salt applied on the road surface during the winter season. Additional sensitivity studies showed that the accurate logging of salt applications is a prerequisite for predicting salt emissions, as well as good quality data on precipitation. It also highlights the need for more simultaneous measurements of salt loading together with ambient air concentrations to help improve model parameterisations of salt and moisture removal processes.

Tungsten/copper composite deposits produced by a cold spray

International Nuclear Information System (INIS)

Kang, Hyun-Ki; Kang, Suk Bong

2003-01-01

An agglomerated tungsten/copper composite powder was both cold sprayed and plasma sprayed onto a mild steel substrate for electronic package applications. Most pores resulting from the spraying were found in the vicinity of the tungsten-rich regions of the final product. The levels of porosity varied with the amount of tungsten present. No copper oxidation was found at the cold-sprayed deposit, but relatively high copper oxidation was observed at the plasma-sprayed deposit

A novel method of non-violent dissolution of sodium metal in a concentrated aqueous solution of Epsom salt

International Nuclear Information System (INIS)

Lakshmanan, A.R.; Prasad, M.V.R.; Ponraju, D.; Krishnan, H.

2004-01-01

A new technique of non-violent and fast dissolution of sodium metal in a concentrated aqueous solution of Epsom salt (MgSO 4 .7H 2 O) at room temperature (RT) has been developed. The dissolution process is mildly exothermic but could be carried out even in a glass beaker in air under swift stirring condition. The reaction products consist of mixed salts of MgSO 4 and Na 2 SO 4 as well as Mg(OH) 2 which are only mildly alkaline and hence are non-corrosive and non-hazardous unlike NaOH. A 50 mL solution having Epsom salt concentration of 2 M was found to give the optimal composition for disposal of 1 g of sodium. Supersaturated (>2.7 M), as well as dilute (<1.1 M) solutions, however, cause violent reactions and hence should be avoided. Repeated sodium dissolution in Epsom solution produced a solid waste of 4.7 g per g of sodium dissolved which is comparable with the waste (4 g) produced in 8 M NaOH solution. A 1.4 M Epsom solution sprayed with a high-pressure jet cleaner at RT in air easily removed the sodium blocked inside a metal pipe made of mild steel. The above jet also dissolved peacefully residual sodium collected on the metal tray after a sodium fire experiment. No sodium fire or explosion was observed during this campaign. The Epsom solution spray effectively neutralized the minor quantity of sodium aerosol produced during this campaign. This novel technique would hence be quite useful for draining sodium from fast breeder reactor components and bulk processing of sodium as well as for sodium fire fighting

Research Into Ni-Cr-Si-B Coating Sprayed Onto Aluminium Substrate Using the Method of Plasma Spray

Directory of Open Access Journals (Sweden)

Raimonda Lukauskaitė

2013-02-01

Full Text Available The article deals with Ni base coatings deposited on aluminium substrate applying the method of plasma spray. The purpose of the conducted research is to improve the physical and mechanical properties of coatings on the surface of aluminium alloy work pieces. Spraying on aluminium alloys encounters serious problems, and therefore this work analyses the ways to make the situation more favourable. Before spraying, the surfaces of substrates were modified employing chemical and mechanical pre-treatment methods. The aim of pre-treating aluminium alloys was to remove oxide layers from the aluminium surface. Coating microstructures and porosity were characterised applying optical microscopy. Differences in the roughness of pre-treated surfaces have been determined referring to profilometry. The paper investigates the influence of the adhesion of plasma spray coatings on aluminium surface pretreatment. Microhardness technique was applied for measuring the hardness of coatings. The study also describes and compares the mechanical properties of Ni base coatings deposited on different pre-treated aluminium substrates using plasma spray.Article in Lithuanian

Research Into Ni-Cr-Si-B Coating Sprayed Onto Aluminium Substrate Using the Method of Plasma Spray

Directory of Open Access Journals (Sweden)

Raimonda Lukauskaitė

2012-12-01

Full Text Available The article deals with Ni base coatings deposited on aluminium substrate applying the method of plasma spray. The purpose of the conducted research is to improve the physical and mechanical properties of coatings on the surface of aluminium alloy work pieces. Spraying on aluminium alloys encounters serious problems, and therefore this work analyses the ways to make the situation more favourable. Before spraying, the surfaces of substrates were modified employing chemical and mechanical pre-treatment methods. The aim of pre-treating aluminium alloys was to remove oxide layers from the aluminium surface. Coating microstructures and porosity were characterised applying optical microscopy. Differences in the roughness of pre-treated surfaces have been determined referring to profilometry. The paper investigates the influence of the adhesion of plasma spray coatings on aluminium surface pretreatment. Microhardness technique was applied for measuring the hardness of coatings. The study also describes and compares the mechanical properties of Ni base coatings deposited on different pre-treated aluminium substrates using plasma spray.Article in Lithuanian

Sprayed concrete linings

Energy Technology Data Exchange (ETDEWEB)

Hindle, D.

1999-12-01

Sprayed concrete, or shotcrete, was invented in the 1920s for preserving dinosaur skeletons and was used underground initially in coalmines for the preservation and fine proofing of timber supports. Its use as a support lining in rock tunnelling was developed in the 1950s and 60s. The article surveys equipment available from major manufacturers and suppliers of concrete spraying equipment (Aliva, Cifa, GIA, Industri, Ingersoll Rand, etc.), specialist cement and additive manufacturers (Castle, Cement, Moria Carbotech). manufacturers of lattice girders and fibre reinforcement, and manufacturers of instrumentation for tunnel linings. 5 tabs., 9 photos.

Peltier-based cloud chamber

Science.gov (United States)

Nar, Sevda Yeliz; Cakir, Altan

2018-02-01

Particles produced by nuclear decay, cosmic radiation and reactions can be identified through various methods. One of these methods that has been effective in the last century is the cloud chamber. The chamber makes visible cosmic particles that we are exposed to radiation per second. Diffusion cloud chamber is a kind of cloud chamber that is cooled by dry ice. This traditional model has some application difficulties. In this work, Peltier-based cloud chamber cooled by thermoelectric modules is studied. The new model provided uniformly cooled base of the chamber, moreover, it has longer lifetime than the traditional chamber in terms of observation time. This gain has reduced the costs which spent each time for cosmic particle observation. The chamber is an easy-to-use system according to traditional diffusion cloud chamber. The new model is portable, easier to make, and can be used in the nuclear physics experiments. In addition, it would be very useful to observe Muons which are the direct evidence for Lorentz contraction and time expansion predicted by Einsteins special relativity principle.

Computational Analysis of Spray Jet Flames

Science.gov (United States)

Jain, Utsav

There is a boost in the utilization of renewable sources of energy but because of high energy density applications, combustion will never be obsolete. Spray combustion is a type of multiphase combustion which has tremendous engineering applications in different fields, varying from energy conversion devices to rocket propulsion system. Developing accurate computational models for turbulent spray combustion is vital for improving the design of combustors and making them energy efficient. Flamelet models have been extensively used for gas phase combustion because of their relatively low computational cost to model the turbulence-chemistry interaction using a low dimensional manifold approach. This framework is designed for gas phase non-premixed combustion and its implementation is not very straight forward for multiphase and multi-regime combustion such as spray combustion. This is because of the use of a conserved scalar and various flamelet related assumptions. Mixture fraction has been popularly employed as a conserved scalar and hence used to parameterize the characteristics of gaseous flamelets. However, for spray combustion, the mixture fraction is not monotonic and does not give a unique mapping in order to parameterize the structure of spray flames. In order to develop a flamelet type model for spray flames, a new variable called the mixing variable is introduced which acts as an ideal conserved scalar and takes into account the convection and evaporation of fuel droplets. In addition to the conserved scalar, it has been observed that though gaseous flamelets can be characterized by the conserved scalar and its dissipation, this might not be true for spray flamelets. Droplet dynamics has a significant influence on the spray flamelet and because of effects such as flame penetration of droplets and oscillation of droplets across the stagnation plane, it becomes important to accommodate their influence in the flamelet formulation. In order to recognize the

High Temperature Fission Chamber for He- and FLiBe-cooled Reactors

Energy Technology Data Exchange (ETDEWEB)

Bell, Zane W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Giuliano, Dominic R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Holcomb, David Eugene [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lance, Michael J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Miller, Roger G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Warmack, Robert J. Bruce [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wilson, Dane F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Harrison, Mark J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-01-01

We have evaluated candidate technologies for in-core fission chambers for high-temperature reactors to monitor power level via measurements of neutron flux from start-up through full power at up to 800°C. This research is important because there are no commercially available instruments capable of operating above 550 °C. Component materials and processes were investigated for fission chambers suitable for operation at 800 °C in reactors cooled by molten fluoride salt (FLiBe) or flowing He, with an emphasis placed on sensitivity (≥ 1 cps/nv), service lifetime (2 years at full power), and resistance to direct immersion in FLiBe. The latter gives the instrument the ability to survive accidents involving breach of a thimble. The device is envisioned to be a two-gap, three-electrode instrument constructed from concentric nickel-plated alumina cylinders and using a noble gas–nitrogen fill-gas. We report the results of measurements and calculations of the response of fill gasses, impurity migration in nickel alloy, brazing of the alumina insulator, and thermodynamic calculations.

The HAW Project. Test disposal of highly radioactive radiation sources in the Asse salt mine

International Nuclear Information System (INIS)

Rothfuchs, T.; Mueller-Lyda, I.; Raynal, M.; Major, J.C.

1993-01-01

In order to prove the safe disposal of high-level radioactive waste (HAW) in salt a five years test disposal of thirty highly radioactive canisters is planned in the Asse salt mine in the Federal Republic of Germany. The thirty canisters containing the radionuclides Caesium 137 and Strontium 90 in quantities sufficient to cover the bandwith of heat generation and gamma radiation of real HAW will be emplaced in six boreholes located in two galleries at the 800-m-level. Two electrical heater tests were already started in November 1988 and are continuously surveyed in respect of the thermomechanical and geochemical response of the rock mass. Also the handling system necessary for the emplacement of the radioactive canisters was developed and successfully tested. A laboratory investigation programme on radiation effects in salt is being performed in advance to the radioactive canister emplacement. This programme includes the investigation of thermally and radiolytically induced water and gas release from the rock salt and the radiolytical decomposition of salt minerals. For gamma dose and dose rate measurements in the test field measuring systems consisting of ionization chambers as well as solid state dosemeters were developed and tested. 70 refs

Plasma sprayed coatings on crankshaft used steels

Science.gov (United States)

Mahu, G.; Munteanu, C.; Istrate, B.; Benchea, M.

2017-08-01

Plasma spray coatings may be an alternative to conventional heat treatment of main journals and crankpins of the crankshaft. The applications of plasma coatings are various and present multiple advantages compared to electric arc wire spraying or flame spraying. The study examines the layers sprayed with the following powders: Cr3C2- 25(Ni 20Cr), Al2O3- 13TiO2, Cr2O3-SiO2- TiO2 on the surface of steels used in the construction of a crankshaft (C45). The plasma spray coatings were made with the Spray wizard 9MCE facility at atmospheric pressure. The samples were analyzed in terms of micro and morphological using optical microscopy, scanning electron microscopy and X-ray diffraction. Wear tests on samples that have undergone simulates extreme working conditions of the crankshafts. In order to emphasize adherence to the base material sprayed layer, were carried out tests of microscratches and micro-indentation. Results have showed a relatively compact morphological aspect given by the successive coatings with splat-like specific structures. Following the microscratch analysis it can be concluded that Al2O3-13TiO2 coating has a higher purpose in terms of hardness compared to Cr3C2-(Ni 20Cr) and Cr2O3-SiO2- TiO2 powders. Thermal coatings of the deposited powders have increased the mechanical properties of the material. The results stand to confirm that plasma sprayed Al2O3-13TiO2 powder is in fact a efficient solution for preventing mechanical wear, even with a faulty lubrication system.

To spray or not to spray? Understanding participation in an indoor residual spray campaign in Arequipa, Peru.

Science.gov (United States)

Paz-Soldán, Valerie A; Bauer, Karin M; Hunter, Gabrielle C; Castillo-Neyra, Ricardo; Arriola, Vanessa D; Rivera-Lanas, Daniel; Rodriguez, Geoffrey H; Toledo Vizcarra, Amparo M; Mollesaca Riveros, Lina M; Levy, Michael Z; Buttenheim, Alison M

2018-01-01

Current low participation rates in vector control programmes in Arequipa, Peru complicate the control of Chagas disease. Using focus groups (n = 17 participants) and semi-structured interviews (n = 71) conducted in March and May 2013, respectively, we examined barriers to and motivators of household participation in an indoor residual spray (IRS) campaign that had taken place one year prior in Arequipa. The most common reported barriers to participation were inconvenient spray times due to work obligations, not considering the campaign to be necessary, concerns about secondary health impacts (e.g. allergic reactions to insecticides), and difficulties preparing the home for spraying (e.g. moving heavy furniture). There was also a low perception of risk for contracting Chagas disease that might affect participation. The main motivator to participate was to ensure personal health and well-being. Future IRS campaigns should incorporate more flexible hours, including weekends; provide appropriate educational messages to counter concerns about secondary health effects; incorporate peer educators to increase perceived risk to Chagas in community; obtain support from community members and leaders to build community trust and support for the campaign; and assist individuals in preparing their homes. Enhancing community trust in both the need for the campaign and its operations is key.

Injector spray characterization of methanol in reciprocating engines

Science.gov (United States)

Dodge, L.; Naegeli, D.

1994-06-01

This report covers a study that addressed cold-starting problems in alcohol-fueled, spark-ignition engines by using fine-spray port-fuel injectors to inject fuel directly into the cylinder. This task included development and characterization of some very fine-spray, port-fuel injectors for a methanol-fueled spark-ignition engine. After determining the spray characteristics, a computational study was performed to estimate the evaporation rate of the methanol fuel spray under cold-starting and steady-state conditions.

Sensors Based Measurement Techniques of Fuel Injection and Ignition Characteristics of Diesel Sprays in DI Combustion System

Directory of Open Access Journals (Sweden)

S. Rehman

2016-09-01

Full Text Available Innovative sensor based measurement techniques like needle lift sensor, photo (optical sensor and piezoresistive pressure transmitter are introduced and used to measure the injection and combustion characteristics in direct injection combustion system. Present experimental study is carried out in the constant volume combustion chamber to study the ignition, combustion and injection characteristics of the solid cone diesel fuel sprays impinging on the hot surface. Hot surface ignition approach has been used to create variety of advanced combustion systems. In the present study, the hot surface temperatures were varied from 623 K to 723 K. The cylinder air pressures were 20, 30 and 40 bar and fuel injection pressures were 100, 200 and 300 bar. It is found that ignition delay of fuel sprays get reduced with the rise in injection pressure. The ignition characteristics of sprays much less affected at high fuel injection pressures and high surface temperatures. The fuel injection duration reduces with the increase in fuel injection pressures. The rate of heat release becomes high at high injection pressures and it decreases with the increase in injection duration. It is found that duration of burn/combustion decrease with the increase in injection pressure. The use of various sensors is quite effective, reliable and accurate in measuring the various fuel injection and combustion characteristics. The study simulates the effect of fuel injection system parameters on combustion performance in large heavy duty engines.

Development of cold sprayed Cu coating for canister

International Nuclear Information System (INIS)

Kim, Hyung Jun; Kang, Yoon Ha

2010-01-01

Cold sprayed Cu deposition was studied for the application of outer part of canister for high level nuclear waste. Five commercially available pure Cu powders were analyzed and sprayed by high pressure cold spray system. Electrochemical corrosion test using potentiostat in 3.5% NaCl solution was conducted as well as microstructural analysis including hardness and oxygen content measurements. Overall evaluation of corrosion performance of cold sprayed Cu deposition is inferior to forged and extruded Cu plates, but some of Cu depositions are comparable to Cu plates. The simulated corrosion test in 200m underground cave is still in progress. The effect of cold spray process parameters was also studied and the results show that the type of nozzle is the most important other than powder feed rate, spray distance, and scan speed. 1/10 scale miniature of canister was manufactured confirming that the production of full scale canister is possible

Dual ionization chamber

International Nuclear Information System (INIS)

Mallory, J.; Turlej, Z.

1981-01-01

Dual ionization chambers are provided for use with an electronic smoke detector. The chambers are separated by electrically-conductive partition. A single radiation source extends through the partition into both chambers, ionizing the air in each. The mid-point current of the device may be balanced by adjusting the position of the source

Understanding the Impact of Model Surfactants on Cloud Condensation Nuclei Activity of Sea Spray Aerosols

Science.gov (United States)

Forestieri, S.; Cappa, C. D.; Ruehl, C. R.; Bertram, T. H.; Staudt, S.; Kuborn, T.

2017-12-01

Aerosol impacts on cloud properties, also known as indirect effects, remain a major source of uncertainty in modeling global radiative forcing. Reducing this uncertainty necessitates better understanding of how aerosol chemical composition impacts the cloud-forming ability of aerosols. The presence of surfactants in aerosols can decrease the surface tension of activating droplets relative to water and lead to more efficient activation. The importance of this effect has been debated, but recent surface tension measurements of microscopic droplets indicate that surface tension is substantially depressed relative to water for lab-generated particles consisting of salt and a single organic species and for complex mixtures of organic matter. However, little work has been done on understanding how chemical complexity (i.e. interaction between different surfactant species) impacts surface tension for particles containing mixtures of surfactants. In this work, we quantified the surface tension of lab-generated aerosols containing surfactants that are commonly found in nascent sea spray aerosol (SSA) at humidities close to activation using a continuous flow stream-wise thermal gradient chamber (CFSTGC). Surface tension was quantified for particles containing single surfactant species and mixtures of these surfactants to investigate the role of chemical complexity on surface tension and molecular packing at the air-water interface. For all surfactants tested in this study, substantial surface tension depression (20-40 mN/m) relative to water was observed for particles containing large fractions of organic matter at humidities just below activation. However, the presence of these surfactants only weakly depressed surface tension at activation. Kinetic limitations were observed for particles coated with just palmitic acid, since palmitic acid molecules inhibit water uptake through their ability to pack tightly at the surface. However, these kinetic limitations disappeared when

Spray Modeling for Outwardly-Opening Hollow-Cone Injector

KAUST Repository

Sim, Jaeheon

2016-04-05

The outwardly-opening piezoelectric injector is gaining popularity as a high efficient spray injector due to its precise control of the spray. However, few modeling studies have been reported on these promising injectors. Furthermore, traditional linear instability sheet atomization (LISA) model was originally developed for pressure swirl hollow-cone injectors with moderate spray angle and toroidal ligament breakups. Therefore, it is not appropriate for the outwardly-opening injectors having wide spray angles and string-like film structures. In this study, a new spray injection modeling was proposed for outwardly-opening hollow-cone injector. The injection velocities are computed from the given mass flow rate and injection pressure instead of ambiguous annular nozzle geometry. The modified Kelvin-Helmholtz and Rayleigh-Taylor (KH-RT) breakup model is used with adjusted initial Sauter mean diameter (SMD) for modeling breakup of string-like structure. Spray injection was modeled using a Lagrangian discrete parcel method within the framework of commercial CFD software CONVERGE, and the new model was implemented through the user-defined functions. A Siemens outwardly-opening hollow-cone spray injector was characterized and validated with existing experimental data at the injection pressure of 100 bar. It was found that the collision modeling becomes important in the current injector because of dense spray near nozzle. The injection distribution model showed insignificant effects on spray due to small initial droplets. It was demonstrated that the new model can predict the liquid penetration length and local SMD with improved accuracy for the injector under study.

Research of Plasma Spraying Process on Aluminum-Magnesium Alloy

Directory of Open Access Journals (Sweden)

Patricija Kavaliauskaitė

2016-04-01

Full Text Available The article examines plasma sprayed 95Ni-5Al coatings on alu-minum-magnesium (Mg ≈ 2,6‒3,6 % alloy substrate. Alumi-num-magnesium samples prior spraying were prepared with mechanical treatment (blasting with Al2O3. 95Ni-5Al coatings on aluminum-magnesium alloys were sprayed with different parameters of process and coating‘s thickness, porosity, micro-hardness and microstructure were evaluated. Also numerical simulations in electric and magnetic phenomena of plasma spray-ing were carried out.

Ternary ceramic thermal spraying powder and method of manufacturing thermal sprayed coating using said powder

Energy Technology Data Exchange (ETDEWEB)

Vogli, Evelina; Sherman, Andrew J.; Glasgow, Curtis P.

2018-02-06

The invention describes a method for producing ternary and binary ceramic powders and their thermal spraying capable of manufacturing thermal sprayed coatings with superior properties. Powder contain at least 30% by weight ternary ceramic, at least 20% by weight binary molybdenum borides, at least one of the binary borides of Cr, Fe, Ni, W and Co and a maximum of 10% by weight of nano and submicro-sized boron nitride. The primary crystal phase of the manufactured thermal sprayed coatings from these powders is a ternary ceramic, while the secondary phases are binary ceramics. The coatings have extremely high resistance against corrosion of molten metal, extremely thermal shock resistance and superior tribological properties at low and at high temperatures.

Spray-loading: A cryogenic deposition method for diamond anvil cell

Science.gov (United States)

Scelta, Demetrio; Ceppatelli, Matteo; Ballerini, Riccardo; Hajeb, Ahmed; Peruzzini, Maurizio; Bini, Roberto

2018-05-01

An efficient loading technique has been developed for flammable, toxic, or explosive gases which can be condensed at liquid nitrogen temperature and ambient pressure in membrane diamond anvil cells (DACs). This cryogenic technique consists in a deposition of small quantities of the desired gas directly into the sample chamber. The deposition is performed using a capillary that reaches the space between the diamond anvils. The DAC is kept under inert gas overpressure during the whole process, in order to avoid contamination from atmospheric O2, CO2, and H2O. This technique provides significant advantages over standard cryo-loading and gas-loading when the condensation of dangerous samples at liquid nitrogen temperature raises safety concerns because it allows dealing with minimum quantities of condensed gases. The whole procedure is particularly fast and efficient. The "spray-loading" has been successfully used in our laboratory to load several samples including acetylene, ammonia, ethylene, and carbon dioxide/water or red phosphorus/NH3 mixtures.

Evaluation of mechanical properties of Aluminum-Copper cold sprayed and alloy 625 wire arc sprayed coatings

Science.gov (United States)

Bashirzadeh, Milad

This study examines microstructural-based mechanical properties of Al-Cu composite deposited by cold spraying and wire arc sprayed nickel-based alloy 625 coating using numerical modeling and experimental techniques. The microhardness and elastic modulus of samples were determined using the Knoop hardness technique. Hardness in both transverse and longitudinal directions on the sample cross-sections has been measured. An image-based finite element simulation algorithm was employed to determine the mechanical properties through an inverse analysis. In addition mechanical tests including, tensile, bending, and nano-indentation tests were performed on alloy 625 wire arc sprayed samples. Overall, results from the experimental tests are in relatively good agreement for deposited Al-Cu composites and alloy 625 coating. However, results obtained from numerical simulation are significantly higher in value than experimentally obtained results. Examination and comparison of the results are strong indications of the influence of microstructure characteristics on the mechanical properties of thermally spray deposited coatings.

Carbon Dioxide and Methane Emissions from Diverse Zones of a California Salt Marsh

Science.gov (United States)

Wang, F.; King, J. Y.

2016-12-01

With high primary productivity and low organic matter decomposition rates, salt marshes sequester carbon from the atmosphere and contribute to mitigation of climate change. However, the role of wetlands in carbon sequestration is offset by CO2 and CH4 emissions whose magnitudes remain coarsely constrained. To better understand the spatiotemporal dynamics of gaseous carbon fluxes from marsh soils in a Mediterranean climate, we collected air and soil samples over the course of 10 months at Carpinteria Salt Marsh Reserve (CSMR) located in the County of Santa Barbara, California. The CSMR consists of four distinct zones characterized by differences in elevation, tidal regime, and vegetation. Twelve static chambers were deployed among two lower marsh zones, a salt flat, and a marsh-upland transition zone for fortnightly flux measurements from September, 2015 to May, 2016. In August, 2015 and June, 2016, soil cores up to 50 cm deep were extracted near the chambers, segmented by depth, and analyzed for soil moisture, bulk density, EC, pH, organic/inorganic carbon, and total nitrogen content. The gaseous carbon fluxes showed significant spatiotemporal variability, and soil properties differed noticeably by zone and by depth. Integrated over the study period, the marsh-upland transition zone had the highest CO2 fluxes at 292 g C/m2, followed closely by the lower marsh zones (271 g C/m2 and 189 g C/m2), which were one order of magnitude higher than the CO2 fluxes from the salt flat (23 g C/m2). Seasonally, CO2 fluxes were 2.5 to 3.5 times higher during the warmer months (Sept - Oct, Mar - May) than the colder months (Nov - Feb) across all zones. The CH4 fluxes were more temporally heterogeneous, but overall the CH4 emissions from the lower marsh zones (1.37 g C/m2 and 0.41 g C/m2) surpassed those from the salt flat (0.054 g C/m2) by an order of magnitude, and the marsh-upland transition zone was a net methane sink (-0.029 g C/m2). Our results show that soil gaseous carbon

Wire Chamber

CERN Multimedia

Magnetoscriptive readout wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

Wire chamber

CERN Multimedia

1967-01-01

Magnetoscriptive readout wire chamber.Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

Influence of powder and spray parameters on erosion and corrosion properties of HVOF sprayed WC-Co-Cr coatings

Energy Technology Data Exchange (ETDEWEB)

Berget, John

1998-07-01

Thermal spraying is a generic term including various processes used to deposit coatings on surfaces. The coating material is in the form of powder or a wire and is melted or softened by means of a heat source. A gas stream accelerates the material towards a prepared surface and deposits it there to form the coating. Examples of components being maintained by application of thermal spray coatings are gate valves and ball valves for the offshore industry and turbine blades in power generations installations. Recent investigation has shown that the commonly used coating material WC-Co is not corrosion resistant. But it can be improved by the addition of Cr. The main objective of this thesis is to study the influence of spray process control variables and powder characteristics on the erosion and erosion-corrosion properties of the coatings. Spray process variables investigated include energy input, powder feed rate and spray distance. Powder characteristics studied are average size of the WC particles, relative proportions of Co and Cr in the metal phase and powder grain size distribution.

Cryogen spray cooling: Effects of droplet size and spray density on heat removal.

Science.gov (United States)

Pikkula, B M; Torres, J H; Tunnell, J W; Anvari, B

2001-01-01

Cryogen spray cooling (CSC) is an effective method to reduce or eliminate non-specific injury to the epidermis during laser treatment of various dermatological disorders. In previous CSC investigations, fuel injectors have been used to deliver the cryogen onto the skin surface. The objective of this study was to examine cryogen atomization and heat removal characteristics of various cryogen delivery devices. Various cryogen delivery device types including fuel injectors, atomizers, and a device currently used in clinical settings were investigated. Cryogen mass was measured at the delivery device output orifice. Cryogen droplet size profiling for various cryogen delivery devices was estimated by optically imaging the droplets in flight. Heat removal for various cryogen delivery devices was estimated over a range of spraying distances by temperature measurements in an skin phantom used in conjunction with an inverse heat conduction model. A substantial range of mass outputs were measured for the cryogen delivery devices while heat removal varied by less than a factor of two. Droplet profiling demonstrated differences in droplet size and spray density. Results of this study show that variation in heat removal by different cryogen delivery devices is modest despite the relatively large difference in cryogen mass output and droplet size. A non-linear relationship between heat removal by various devices and droplet size and spray density was observed. Copyright 2001 Wiley-Liss, Inc.

Aluminium-12wt% silicon coating prepared by thermal spraying technique: Part 1 optimization of spray condition based on a design of experiment

Directory of Open Access Journals (Sweden)

Jiansirisomboon, S.

2006-03-01

Full Text Available At present, thermal spray technology is used for maintenance parts of various machines in many industries. This technology can be used to improve the surface wear resistance. Therefore, this technology can significantly reduce cost of manufacturing. Al-12wt%Si alloy is an interesting and popular material used in the automotive industry. This research studies the suitable condition for spraying of Al-12wt%Si powder. This powder was sprayed by a flame spray technique onto low carbon steel substrates. The suitable conditions for spraying can be achieved by a design of experiment (DOE principle, which provided statistical data defined at 90% confidence. This research used control factors, which were oxygen flow rate, acetylene flow rate and spray distance. The satisfaction levels of these factors were set at 3 levels, i.e. low, medium and high, in order to determine suitable responses, which were hardness, thickness, wear rate and percentage volume fraction of porosity. It was found that the optimized condition for spraying Al-12wt%Si powder consisted of 38 ft3/hr (1.026 m3/hr of oxygen flow rate, 27 ft3/hr (0.729 m3/hr of acetylene flow rate and 58 mm of spray distance.

Plasma sprayed Nd-Fe-B permanent magnets

International Nuclear Information System (INIS)

Willson, M.; Bauser, S.; Liu, S.; Huang, M.

2003-01-01

This study demonstrated that the plasma spray deposition method is an alternative process for producing Nd-Fe-B magnets in addition to the two existing principal processes: the powder metallurgy process for producing sintered Nd-Fe-B magnets and the melt spinning process for bonded Nd-Fe-B magnets. Plasma spray is a potentially better process for producing magnetic parts with complicated shape, large area, thin thickness, small dimension, or unusual geometry. High intrinsic coercivity greater than 15 kOe was readily obtained for Nd 16 Dy 1 Fe 76 B 7 even in the as-deposited condition when the substrate was preheated. The plasma spray process contains only three steps: melting, crushing, and plasma spray, which is much simpler than the powder metallurgy and melt spinning processes. Without preheating the substrate, the coercivity was usually very low (∼0.1 kOe) in the as-deposited condition and it increased to 10 to >15 kOe after anneal. Evidence of magnetocrystalline anisotropy was observed in plasma sprayed Nd 15 Dy 1 Fe 77 B 7 magnets when the substrate was not preheated. It is believed that a crystal texture was developed during the plasma spray as a result of the existence of a temperature gradient in the solidifying melt

Nano spray drying for encapsulation of pharmaceuticals.

Science.gov (United States)

Arpagaus, Cordin; Collenberg, Andreas; Rütti, David; Assadpour, Elham; Jafari, Seid Mahdi

2018-05-17

Many pharmaceuticals such as pills, capsules, or tablets are prepared in a dried and powdered form. In this field, spray drying plays a critical role to convert liquid pharmaceutical formulations into powders. In addition, in many cases it is necessary to encapsulate bioactive drugs into wall materials to protect them against harsh process and environmental conditions, as well as to deliver the drug to the right place and at the correct time within the body. Thus, spray drying is a common process used for encapsulation of pharmaceuticals. In view of the rapid progress of nanoencapsulation techniques in pharmaceutics, nano spray drying is used to improve drug formulation and delivery. The nano spray dryer developed in the recent years provides ultrafine powders at nanoscale and high product yields. In this paper, after explaining the concept of nano spray drying and understanding the key elements of the equipment, the influence of the process parameters on the final powders properties, like particle size, morphology, encapsulation efficiency, drug loading and release, will be discussed. Then, numerous application examples are reviewed for nano spray drying and encapsulation of various drugs in the early stages of product development along with a brief overview of the obtained results and characterization techniques. Copyright © 2018 Elsevier B.V. All rights reserved.

Light extinction method on high-pressure diesel injection

Science.gov (United States)

Su, Tzay-Fa; El-Beshbeeshy, Mahmound S.; Corradini, Michael L.; Farrell, Patrick V.

1995-09-01

A two dimensional optical diagnostic technique based on light extinction was improved and demonstrated in an investigation of diesel spray characteristics at high injection pressures. Traditional light extinction methods require the spray image to be perpendicular to the light path. In the improved light extinction scheme, a tilted spray image which has an angle with the light path is still capable of being processed. This technique utilizes high speed photography and digital image analysis to obtain qualitative and quantitative information of the spray characteristics. The injection system used was an electronically controlled common rail unit injector system with injection pressures up to 100 MPa. The nozzle of the injector was a mini-sac type with six holes on the nozzle tip. Two different injection angle nozzles, 125 degree(s) and 140 degree(s), producing an in-plane tilted spray and an out of plane tilted spray were investigated. The experiments were conducted on a constant volume spray chamber with the injector mounted tilted at an angle of 62.5 degree(s)$. Only one spray plume was viewed, and other sprays were free to inject to the chamber. The spray chamber was pressurized with argon and air under room temperature to match the combustion chamber density at the start of the injection. The experimental results show that the difference in the spray tip penetration length, spray angle, and overall average Sauter mean diameter is small between the in- plane tilted spray and the out of plane tilted spray. The results also show that in-plane tilted spray has a slightly larger axial cross- section Sauter mean diameter than the out of plane tilted spray.

9 CFR 590.542 - Spray process drying operations.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Spray process drying operations. 590..., Processing, and Facility Requirements § 590.542 Spray process drying operations. (a) The drying room shall be... interrupted. (1) Spray nozzles, orifices, cores, or whizzers shall be cleaned immediately after cessation of...

Ionization chambers

International Nuclear Information System (INIS)

Boag, J.W.

1987-01-01

Although a variety of solid-state and chemical methods for measuring radiation dose have been developed in recent decades and calorimetry can now provide an absolute standard of reference, ionization dosimetry retains its position as the most widely used, most convenient, and, in most situations, most accurate method of measuring either exposure or absorbed dose. The ionization chamber itself is the central element in this system of dosimetry. In this chapter the principles governing the construction and operation of ionization chambers of various types are examined. Since the ionization chambers now in general use are nearly all of commercial manufacture, the emphasis is on operating characteristics and interpretation of measurements rather than on details of construction, although some knowledge of the latter is often required when applying necessary corrections to the measured quantities. Examples are given of the construction of typical chambers designed for particular purposes, and the methods of calibrating them are discussed

Vertically aligned ZnO nanorods via self-assembled spray pyrolyzed nanoparticles for dye-sensitized solar cells

International Nuclear Information System (INIS)

Dwivedi, Charu; Dutta, V

2012-01-01

Well-aligned zinc oxide (ZnO) nanorods are fabricated on indium-tin-oxide (ITO) coated glass substrates via self-assembly of ZnO nanoparticles created using continuous spray pyrolysis (CoSP) technique. The method involves pre-treatment by dip-coating the substrate with a solution comprising of zinc salt for creating a seed layer, and then spray-pyrolyzed ZnO nanoparticles self-assemble on the pre-treated substrate. The effect of the substrate pre-treatment and the deposition time (t dep ) of nanoparticles is investigated. The results show that the substrate pre-treatment influences the growth of ZnO nanorods which are absent without the pre-treatment. Nanoparticle collection and nanorod growth on different substrates are done simultaneously. The thin films of as-grown nanorods are used as photoelectrode materials to fabricate dye-sensitized solar cells (DSSCs) and the effect of nanorods grown for different times has been studied. The best performance with this cell structure is found for the layer with t dep =15 min, which showed a conversion efficiency of 1.77% for the cell area of 0.25 cm 2

High-power electronics thermal management with intermittent multijet sprays

International Nuclear Information System (INIS)

Panão, Miguel R.O.; Correia, André M.; Moreira, António L.N.

2012-01-01

Thermal management plays a crucial role in the development of high-power electronics devices, e.g. in electric vehicles. The greatest energy demands occur during power peaks, implying dynamic thermal losses within the vehicle’s driving cycle. Therefore, the need for devising intelligent thermal management systems able to efficiently respond to these power peaks has become a technological challenge. Experiments have been performed with methanol in order to quantify the maximum heat flux removed by a multijet spray to keep the 4 cm 2 surface temperature stabilized and below the threshold of 125 °C. A multijet atomization strategy consists in producing a spray through the multiple and simultaneous impact of N j cylindrical jets. Moreover, the spray intermittency is expressed through the duty cycle (DC), which depends on the frequency and duration of injection. Results evidence that: i) a shorter time between consecutive injection cycles enables a better distribution of the mass flow rate, resulting in larger heat transfer coefficient values, as well as higher cooling efficiencies; ii) compared with continuous sprays, the analysis evidences that an intermittent spray allows benefiting more from phase-change convection. Moreover, the mass flux is mainly affecting heat transfer rather than differences induced in the spray structure by using different multijet configurations. - Highlights: ► Intermittent spray cooling (ISC) is advantageous for intelligent thermal management. ► Distributing the mass flow rate through ISC improves heat transfer. ► Multijet sprays with increasing number of jets have higher heat transfer rates. ► ISC with multijet sprays benefit more from phase-change than continuous sprays.

Current implications of past DDT indoor spraying in Oman.

Science.gov (United States)

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. Copyright © 2015 Elsevier B.V. All rights reserved.

Polydisperse effects in jet spray flames

Science.gov (United States)

Weinberg, Noam; Greenberg, J. Barry

2018-01-01

A laminar jet polydisperse spray diffusion flame is analysed mathematically for the first time using an extension of classical similarity solutions for gaseous jet flames. The analysis enables a comparison to be drawn between conditions for flame stability or flame blow-out for purely gaseous flames and for spray flames. It is found that, in contrast to the Schmidt number criteria relevant to gas flames, droplet size and initial spray polydispersity play a critical role in determining potential flame scenarios. Some qualitative agreement for lift-off height is found when comparing predictions of the theory and sparse independent experimental evidence from the literature.

Spray deposition using impulse atomization technique

International Nuclear Information System (INIS)

Ellendt, N.; Schmidt, R.; Knabe, J.; Henein, H.; Uhlenwinkel, V.

2004-01-01

A novel technique, impulse atomization, has been used for spray deposition. This single fluid atomization technique leads to different spray characteristics and impact conditions of the droplets compared to gas atomization technique which is the common technique used for spray deposition. Deposition experiments with a Cu-6Sn alloy were conducted to evaluate the appropriateness of impulse atomization to produce dense material. Based on these experiments, a model has been developed to simulate the thermal history and the local solidification rates of the deposited material. A numerical study shows how different cooling conditions affect the solidification rate of the material

Containment atmosphere response to external sprays

International Nuclear Information System (INIS)

Green, J.; Almenas, K.

1995-01-01

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 2 /He) concentrations. Modeling results using the CONTAIN code are outlined and code limitations are delineated

Containment atmosphere response to external sprays

Energy Technology Data Exchange (ETDEWEB)

Green, J.; Almenas, K. [Univ. of Maryland, College Park, MD (United States)

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.

Gas microstrip chambers

International Nuclear Information System (INIS)

McIntyre, P.M.; Barasch, E.F.; Bowcock, T.J.V.; Demroff, H.P.; Elliott, S.M.; Howe, M.R.; Lee, B.; Mazumdar, T.K.; Pang, Y.; Smith, D.D.; Wahl, J.; Wu, Y.; Yue, W.K.; Gaedke, R.M.; Vanstraelen, G.

1992-01-01

The gas microstrip chamber has been developed from concept to experimental system during the past three years. A pattern of anode and grid lines are microfabricated onto a dielectric substrate and configured as a high-resolution MWPC. Four recent developments are described: Suitable plastic substrates and lithography techniques for large-area chambers; non-planar silicon-based chambers for 20 μm resolution; integrated on-board synchronous front-end electronics and data buffering; and a porous silicon active cathode for enhanced efficiency and time response. The microstrip chamber appears to be a promising technology for applications in microvertex, tracking spectrometer, muon spectrometer, and transition radiation detection. (orig.)

A Grey-Box Model for Spray Drying Plants

DEFF Research Database (Denmark)

Petersen, Lars Norbert; Poulsen, Niels Kjølstad; Niemann, Hans Henrik

2013-01-01

Multi-stage spray drying is an important and widely used unit operation in the production of food powders. In this paper we develop and present a dynamic model of the complete drying process in a multi-stage spray dryer. The dryer is divided into three stages: The spray stage and two fluid bed...

Numerical Modeling of Diesel Spray Formation and Combustion

NARCIS (Netherlands)

Bekdemir, C.; Somers, L.M.T.; Goey, de L.P.H.

2009-01-01

A study is presented on the modeling of fuel sprays in diesel engines. The objective of this study is in the first place to accurately and efficiently model non-reacting diesel spray formation, and secondly to include ignition and combustion. For that an efficient 1D Euler-Euler spray model [21] is

Inhalational and dermal exposures during spray application of biocides.

Science.gov (United States)

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

Automated Plasma Spray (APS) process feasibility study: Plasma spray process development and evaluation

Science.gov (United States)

Fetheroff, C. W.; Derkacs, T.; Matay, I. M.

1979-01-01

An automated plasma spray (APS) process was developed to apply two layer (NiCrAlY and ZrO2-12Y2O3) thermal-barrier coatings to aircraft gas turbine engine blade airfoils. The APS process hardware consists of four subsystems: a mechanical blade positioner incorporating two interlaced six-degree-of-freedom assemblies; a noncoherent optical metrology subsystem; a microprocessor-based adaptive system controller; and commercial plasma spray equipment. Over fifty JT9D first stage turbine blades specimens were coated with the APS process in preliminary checkout and evaluation studies. The best of the preliminary specimens achieved an overall coating thickness uniformity of + or - 53 micrometers, much better than is achievable manually. Factors limiting this performance were identified and process modifications were initiated accordingly. Comparative evaluations of coating thickness uniformity for manually sprayed and APS coated specimens were initiated. One of the preliminary evaluation specimens was subjected to a torch test and metallographic evaluation.

Plasma spraying of beryllium and beryllium-aluminum-silver alloys

International Nuclear Information System (INIS)

Castro, R.G.; Stanek, P.W.; Elliott, K.E.; Jacobson, L.A.

1994-01-01

A preliminary investigation on plasma-spraying of beryllium and a beryllium-aluminum-4% silver alloy was done at the Los Alamos National Laboratory's Beryllium Atomization and Thermal Spray Facility (BATSF). Spherical Be and Be-Al-4%Ag powders, which were produced by centrifugal atomization, were used as feedstock material for plasma-spraying. The spherical morphology of the powders allowed for better feeding of fine (<38 μm) powders into the plasma-spray torch. The difference in the as-deposited densities and deposit efficiencies of the two plasma-sprayed powders will be discussed along with the effect of processing parameters on the as-deposited microstructure of the Be-Al-4%Ag. This investigation represents ongoing research to develop and characterize plasma-spraying of beryllium and beryllium-aluminum alloys for magnetic fusion and aerospace applications

Plasma spraying of beryllium and beryllium-aluminum-silver alloys

International Nuclear Information System (INIS)

Castro, R.G.; Stanek, P.W.; Elliott, K.E.; Jacobson, L.A.

1993-01-01

A preliminary investigation on plasma-spraying of beryllium and a beryllium-aluminum 4% silver alloy was done at the Los Alamos National Laboratory's Beryllium Atomization and Thermal Spray Facility (BATSF). Spherical Be and Be-Al-4%Ag powders, which were produced by centrifugal atomization, were used as feedstock material for plasma-spraying. The spherical morphology of the powders allowed for better feeding of fine (<38 μm) powders into the plasma-spray torch. The difference in the as-deposited densities and deposit efficiencies of the two plasma-sprayed powders will be discussed along with the effect of processing parameters on the as-deposited microstructure of the Be-Al-4%Ag. This investigation represents ongoing research to develop and characterize plasma-spraying of beryllium and beryllium-aluminum alloys for magnetic fusion and aerospace applications

Unit thermal performance of atmospheric spray cooling systems

International Nuclear Information System (INIS)

Porter, R.W.; Jain, M.; Chaturvedi, S.K.

1980-01-01

Thermal performance of an open atmospheric spray pond or canal depends on the direct-contact evaporative cooling of an individual spray unit (spray nozzle or module) and the interference caused by local heating and humidification. Droplet parameters may be combined into a dimensionless group, number of transfer units (NTU) or equivalent, whereas large-scale air-vapor dynamics determine interference through the local wet-bulb temperature. Quantity NTU were implied from field experiments for a floating module used in steam-condenser spray canals. Previous data were available for a fixed-pipe nozzle assembly used in spray ponds. Quantity NTU were also predicted using the Ranz-Marshall correlations with the Sauter-mean diameter used as the characteristic length. Good agreement with experiments was shown for diameters of 1--1.1 cm (module) and 1.9 mm

Liking, salt taste perception and use of table salt when consuming reduced-salt chicken stews in light of South Africa's new salt regulations.

Science.gov (United States)

De Kock, H L; Zandstra, E H; Sayed, N; Wentzel-Viljoen, E

2016-01-01

This study investigated the impact of salt reduction on liking, salt taste perception, and use of table salt when consuming chicken stew in light of South Africa's new salt recommendations. In total, 432 South-African consumers (aged 35.2 ± 12.3 years) consumed a full portion of a chicken stew meal once at a central location. Four stock cube powders varying in salt content were used to prepare chicken stews: 1) no reduction - 2013 Na level; regular salt level as currently available on the South African market (24473 mg Na/100 g), 2) salt reduction smaller than 2016 level, i.e. 10%-reduced (22025 mg Na/100 g), 3) 2016 salt level, as per regulatory prescriptions (18000 mg Na/100 g), 4) 2019 salt level, as per regulatory prescriptions (13000 mg Na/100 g). Consumers were randomly allocated to consume one of the four meals. Liking, salt taste perception, and use of table salt and pepper were measured. Chicken stews prepared with reduced-salt stock powders were equally well-liked as chicken stews with the current salt level. Moreover, a gradual reduction of the salt in the chicken stews resulted in a reduced salt intake, up to an average of 19% for the total group compared to the benchmark 2013 Na level stew. However, 19% of consumers compensated by adding salt back to full compensation in some cases. More salt was added with increased reductions of salt in the meals, even to the point of full compensation. Further investigation into the impacts of nutrition communication and education about salt reduction on salt taste perception and use is needed. This research provides new consumer insights on salt use and emphasises the need for consumer-focused behaviour change approaches, in addition to reformulation of products. Copyright © 2015 Elsevier Ltd. All rights reserved.

Development of High Throughput Salt Separation System with Integrated Liquid Salt Separation - Salt Distillation Assembly

Energy Technology Data Exchange (ETDEWEB)

Kwon, Sangwoon; Park, K. M.; Kim, J. G.; Jeong, J. H.; Lee, S. J.; Park, S. B.; Kim, S. S.

2013-01-15

The capacity of a salt distiller should be sufficiently large to reach the throughput of uranium electro-refining process. In this study, an assembly composing a liquid separation sieve and a distillation crucible was developed for the sequential operation of a liquid salt separation and a vacuum distillation in the same tower. The feasibility of the sequential salt separation was examined by the rotation test of the sieve-crucible assembly and sequential operation of a liquid salt separation and a vacuum distillation. The adhered salt in the uranium deposits was removed successfully. The salt content in the deposits was below 0.1 wt% after the sequential operation of the liquid salt separation - salt distillation. From the results of this study, it could be concluded that efficient salt separation can be realized by the sequential operation of liquid salt separation and vacuum distillation in one distillation tower since the operation procedures are simplified and no extra operation of cooling and reheating is necessary.

Sea Salt vs. Table Salt: What's the Difference?

Science.gov (United States)

... and healthy eating What's the difference between sea salt and table salt? Answers from Katherine Zeratsky, R.D., L.D. The main differences between sea salt and table salt are in their taste, texture ...

Double chamber ion source

International Nuclear Information System (INIS)

Uman, M.F.; Winnard, J.R.; Winters, H.F.

1978-01-01

The ion source is comprised of two discharge chambers one of which is provided with a filament and an aperture leading into the other chamber which in turn has an extraction orifice. A low voltage arc discharge is operated in an inert gas atmosphere in the filament chamber while an arc of higher voltage is operated in the second ionization chamber which contains a vapor which will give the desired dopant ion species. The entire source is immersed in an axial magnetic field parallel to a line connecting the filament, the aperture between the two chambers and the extraction orifice. (author)

Plasma spray technology process parameters and applications

International Nuclear Information System (INIS)

Sreekumar, K.P.; Karthikeyan, J.; Ananthapadmanabhan, P.V.; Venkatramani, N.; Chatterjee, U.K.

1991-01-01

The current trend in the structural design philosophy is based on the use of substrate with the necessary mechanical properties and a thin coating to exhibit surface properties. Plasma spray process is a versatile surface coating technique which finds extensive application in meeting advance technologies. This report describes the plasma spray technique and its use in developing coatings for various applications. The spray system is desribed in detail including the different variables such as power input to the torch, gas flow rate, powder properties, powder injection, etc. and their interrelation in deciding the quality of the coating. A brief write-up on the various plasma spray coatings developed for different applications is also included. (author). 15 refs., 15 figs., 2 tabs

Ussing Chamber

NARCIS (Netherlands)

Westerhout, J.; Wortelboer, H.; Verhoeckx, K.

2015-01-01

The Ussing chamber system is named after the Danish zoologist Hans Ussing, who invented the device in the 1950s to measure the short-circuit current as an indicator of net ion transport taking place across frog skin (Ussing and Zerahn, Acta Physiol Scand 23:110-127, 1951). Ussing chambers are

A semi-Lagrangian transport method for kinetic problems with application to dense-to-dilute polydisperse reacting spray flows

Energy Technology Data Exchange (ETDEWEB)

Doisneau, François, E-mail: fdoisne@sandia.gov; Arienti, Marco, E-mail: marient@sandia.gov; Oefelein, Joseph C., E-mail: oefelei@sandia.gov

2017-01-15

For sprays, as described by a kinetic disperse phase model strongly coupled to the Navier–Stokes equations, the resolution strategy is constrained by accuracy objectives, robustness needs, and the computing architecture. In order to leverage the good properties of the Eulerian formalism, we introduce a deterministic particle-based numerical method to solve transport in physical space, which is simple to adapt to the many types of closures and moment systems. The method is inspired by the semi-Lagrangian schemes, developed for Gas Dynamics. We show how semi-Lagrangian formulations are relevant for a disperse phase far from equilibrium and where the particle–particle coupling barely influences the transport; i.e., when particle pressure is negligible. The particle behavior is indeed close to free streaming. The new method uses the assumption of parcel transport and avoids to compute fluxes and their limiters, which makes it robust. It is a deterministic resolution method so that it does not require efforts on statistical convergence, noise control, or post-processing. All couplings are done among data under the form of Eulerian fields, which allows one to use efficient algorithms and to anticipate the computational load. This makes the method both accurate and efficient in the context of parallel computing. After a complete verification of the new transport method on various academic test cases, we demonstrate the overall strategy's ability to solve a strongly-coupled liquid jet with fine spatial resolution and we apply it to the case of high-fidelity Large Eddy Simulation of a dense spray flow. A fuel spray is simulated after atomization at Diesel engine combustion chamber conditions. The large, parallel, strongly coupled computation proves the efficiency of the method for dense, polydisperse, reacting spray flows.

Uniform-droplet spray forming

Energy Technology Data Exchange (ETDEWEB)

Blue, C.A.; Sikka, V.K. [Oak Ridge National Lab., TN (United States); Chun, Jung-Hoon [Massachusetts Institute of Technology, Cambridge, MA (United States); Ando, T. [Tufts Univ., Medford, MA (United States)

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.

Emulsions from Aerosol Sprays

Science.gov (United States)

Hengelmolen; Vincent; Hassall

1997-12-01

An electrostatic emulsification apparatus has been designed for the purpose of studying diffusion from oil droplets which have a mean size in the range of approximately 1.5-3.5 &mgr;m, with standard deviations of 40-50%. The emulsification technique involves the collection of a spray of electrically charged oil droplets onto a rotating water film which is sustained from a reservoir. In this way, emulsions with volume fractions of approximately 10(-3) are produced within several minutes at oil flow rates of around 10(-2) ml min-1. Phase-Doppler anemometry (PDA) was used to assess droplet size distributions for the sprays and emulsions. Results show that the mean emulsion droplet size was smaller than the mean spray droplet size by several orders of magnitude. At flow rates around 10(-2) ml min-1, the spray droplet size distribution was little affected by the applied potential between about -4.20 and -4.65 kV (mean droplet size between approximately 7.6 and 7.8 &mgr;m, with standard deviations of approximately 20%), whereas the mean droplet size of the corresponding emulsion decreased more rapidly with applied potential. Above an applied potential of approximately -4.30 kV, which corresponded to an emulsion droplet size below approximately 2 &mgr;m, the measured volume fraction of the emulsion decreased with respect to the volume fraction as calculated on the basis of total amount of injected oil. Copyright 1997 Academic Press. Copyright 1997Academic Press

Salicylic acid confers salt tolerance in potato plants by improving water relations, gaseous exchange, antioxidant activities and osmoregulation.

Science.gov (United States)

Faried, Hafiz Nazar; Ayyub, Chaudhary Muhammad; Amjad, Muhammad; Ahmed, Rashid; Wattoo, Fahad Masoud; Butt, Madiha; Bashir, Mohsin; Shaheen, Muhammad Rashid; Waqas, Muhammad Ahmed

2017-04-01

Potato is an important vegetable; however, salt stress drastically affects its growth and yield. A pot experiment was therefore conducted to assess salicylic acid efficacy in improving performance of potato cultivars, grown under salt stress (50 mmol L -1 ). Salicylic acid at 0.5 mmol L -1 was sprayed on to potato plants after 1 week of salinity application. Salt stress effects were ameliorated by salicylic acid effectively in both the studied cultivars. N-Y LARA proved more responsive to salicylic acid application than 720-110 NARC, which confirmed genetic variation between cultivars. Salicylic acid scavenged reactive oxygen species by improving antioxidant enzyme activities (superoxide dismutase, catalase, peroxidases) and regulating osmotic adjustment (proline, phenolic contents), which led to enhanced water relation and gaseous exchange attributes, and thereby increased potassium availability and reduced sodium content in potato leaves. Moreover, potato tuber yield showed a positive correlation with potassium content, photosynthesis and antioxidant enzyme activities. Salt tolerance efficacy of salicylic acid is authenticated in improving potato crop performance under salt stress. Salicylic acid effect was more pronounced in N-Y LARA, reflecting greater tolerance than 720-110 NARC, which was confirmed as a susceptible cultivar. Hence salicylic acid at 0.5 mmol L -1 and cultivation of N-Y LARA may be recommended in saline soil. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

DELPHI Barrel Muon Chamber Module

CERN Multimedia

1989-01-01

The module was used as part of the muon identification system on the barrel of the DELPHI detector at LEP, and was in active use from 1989 to 2000. The module consists of 7 individual muons chambers arranged in 2 layers. Chambers in the upper layer are staggered by half a chamber width with respect to the lower layer. Each individual chamber is a drift chamber consisting of an anode wire, 47 microns in diameter, and a wrapped copper delay line. Each chamber provided 3 signal for each muon passing through the chamber, from which a 3D space-point could be reconstructed.

Influência de diferentes condições higrotérmicas na resistência à tração de compósitos de fibra de carbono/epóxi modificada Influence of different hygrothermal conditions on the tensile strength of carbon/epoxy 8552 composites

Directory of Open Access Journals (Sweden)

José Antônio P. Cunha

2006-01-01

composites ([0/0]s were investigated. The longitudinal tensile strength results at room temperature was not significantly affected by exposing the samples to either the humidity-controlled chamber or the salt spray chamber. However, the specimens submitted to the humidity-controlled chamber and tested at elevated temperature (80 °C and 90% RH presented a decrease in the longitudinal tensile strength. A small decrease in the transversal tensile strength results was observed during room temperature tests in the samples submitted to salt spray chamber. A higher decrease in the transversal tensile strength was verified in the samples submitted to the humidity-chamber. Samples submitted to the salt spray chamber tested at elevated temperature showed a small decrease in the transversal tensile strength (11%. A drastic reduction in the strength (51% was observed in the samples submitted to the humidity-chamber and tested at high temperature. A fractograph study by scanning electronic microscopy (SEM was performed in every single sample involved in the tests. These results highlight that the elevated temperatures affect the polymeric matrix.

Center for Cold Spray Research and Development

Data.gov (United States)

Federal Laboratory Consortium — This is the only DoD facility capable of cold spray research and development, production, and field-repair. It features three stationary cold spray systems used for...

User friendliness, efficiency & spray quality of stirrup pumps versus hand compression pumps for indoor residual spraying.

Science.gov (United States)

Kumar, Vijay; Kesari, Shreekant; Chowdhury, Rajib; Kumar, Sanjiv; Sinha, Gunjan; Hussain, Saddam; Huda, M Mamun; Kroeger, Axel; Das, Pradeep