Search

Copyright of Machinery & Energetics is the property of National University of Life & Environmental Sciences of Ukraine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This review describes beneficial effects and adverse events of various intranasal medications in treating rhinosinusitis. Application of intranasal steroids has been described in treating all subtypes of adult rhinosinusitis, but reports are limited in pediatrics and mostly in acute pediatric subgroups resulted in benefits While saline irrigation is effective for patients with chronic rhinosinusitis without polyps and in pediatric acute rhinosinusitis, there is no evidence yet for saline drips and sprays. Application of intranasal antifungals and nasal irrigation with surfactant brings more harm than benefits. There is no evidence supporting the use of intranasal antibiotics. We also review influence of devices, methods, and patient head position on nasal and paranasal sinus drug delivery. [ABSTRACT FROM AUTHOR]

An experimental study is conducted on the utilization of water atomization to evaluate its impact on the humidification of steadily flowing air travelling throughout a curved portion of a uniform cross sectional duct. One of the more interesting aspects of curved channel flows is the introduction of a secondary flow pattern in the duct cross-section. The naturally generated turbulences in air flow will certainly assist the mixing between the air and the injected water droplets and improve the heat and mass transfer process encountered in evaporative cooling of the incoming air drought. The present study is considered as a simulation of the gas turbine inlet air cooling by the fogging technique. The drier the air, the better the humidification and cooling process. At higher ambient temperature of 43oC, an increase in the relative humidity of 67.8% and a temperature reduction of 39.6% were recorded at higher water atomizer rate of 24.2ml/s. Generally, the lower half of the curved duct is shown to be less sensitive to the atomizer position for a range of inclination angles between 10o to 45o with radial locations between 5 to 20cm from the inner wall. This situation makes this region most suitable for using atomizing array across it in order to give acceptable performance for cooling system. Nevertheless, the upper half of the curved duct introduces a critical atomizer position suitable for single point spray. This position is considered as the optimum atomizer position defined by a radii ratio of (r/rin = 3.2) and an orientation of -10o to the tangential flow.

Teve-se o objetivo de avaliar o espectro e a uniformidade de gotas em função de equipamentos de pulverização, volumes de calda e dosagem de inseticida na mortalidade de Pseudoplusia includens em laboratório. O trabalho foi conduzido na UNESP de Jaboticabal, sendo realizada uma aplicação sobre as lagartas com os tratamentos: dois equipamentos (bico rotativo e bico hidráulico); dois volumes de calda (17 e 50 L ha-1 para o bico rotativo, e 50 e 100 L ha-1 para o bico hidráulico), e duas dosagens do inseticida endosulfan (0,5 e 1,0 L p.c. ha-1), segundo delineamento inteiramente casualizado, no esquema fatorial 2x2x2 + 1 testemunha. Avaliou-se diariamente a mortalidade das lagartas até o sexto dia após a aplicação dos tratamentos. O espectro de gotas foi avaliado em aparelho medidor de tamanho de partículas, em tempo real, que determina o diâmetro das gotas do espectro pulverizado por meio do desvio de trajetória que sofrem os raios de um feixe de laser ao atingi-las. Verifica-se que, na aplicação em laboratório, onde o produto atinge diretamente o alvo, o volume pode ser reduzido para até 17 L ha-1, sem prejudicar o controle de P. includens; a dosagem de 0,5 L ha-1 do produto comercial endosulfan (recomendada para Anticarsia gemmatalis) não controla satisfatoriamente a lagarta P. includens; o bico rotativo produz gotas de maior uniformidade (AR: 0,52) e com menor percentagem suscetível à deriva (3,3%), comparada à ponta de pulverização de energia hidráulica (AR:1,34 e % gotas ≤ 100 µm: 15,2).It was aimed to evaluate the spectrum and uniformity of droplets in function of sprayers, spraying volumes and rates of chemical insecticide on the mortality of Pseudoplusia includens in laboratory. The work was carried out at UNESP, Jaboticabal, SP, Brazil. The following treatments were applied over the caterpillars: two equipments (atomizer and hydraulic nozzle); two spray volumes (17 and 50 L ha-1 for the atomizer and 50 and 100 L ha-1 for the hydraulic nozzle); and two dosages of the insecticide endosulfan (0.5 and 1.0 L pc ha-1), in fully randomized plots, in a factorial scheme 2x2x2 and 1 untreated check. The caterpillars mortality was evaluated until the 6th day after the application of treatments. The spectrum of the droplets was evaluated in a particle size analyzer in real time determining the diameter and spectrum of droplets sprayed through the laser beam of the analyser. It was verified that the spray volume can be reduced by 17 L ha-1 without losses on the P. includens control. The doses of 0.5 L pc ha-1 (recommended for Anticarsia gemmatalis) did not satisfactorily control the caterpillar soybean looper. The atomizer produces droplets of higher uniformity (SPAN: 0.52) and lower percentage of droplets susceptible to drift (3.3%) compared to hydraulic nozzle (SPAN: 1.34 e % droplets ≤ 100µm: 15.2).

The necessity of odor sensing has been increasing from environmental and health standpoints. Here, we propose the novel concept of a small device which can select odor molecules based on electrostatic spraying. For high selectivity of the target gas or odor, we conducted computational fluid dynamics coupled with an electrostatic field, as well as measurements by particle image velocimetry and anemometry. The computational model successfully reproduced characteristic features of ionic wind. Different trajectories of charged particles were computationally obtained owing to their electrical mobility. The results imply that different materials might be separated by the arrangement of the collecting electrode. [ABSTRACT FROM AUTHOR]

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Intranasal dexmedetomidine has been used successfully for sedation in children. A mucosal atomisation device delivers an atomised solution to the nasal mucosa which facilitates rapid and effective delivery of medication to the systemic circulation. We compared intranasal delivery of dexmedetomidine in a dose of 3 μg.kg(-1) by either atomiser or drops from a syringe in children < 3 years old undergoing transthoracic echocardiography. Two hundred and seventy-nine children were randomly assigned to one or other group. One hundred and thirty-seven children received dexmedetomidine by atomiser and 142 by drops. The successful sedation rate was 82.5% (95% CI 75.3-87.9%) and 84.5% (95% CI 77.7-89.5%) for atomiser and drops, respectively (p = 0.569). Sedation tended to be less successful in older children (p = 0.028, OR 0.949, 95% CI 0.916-0.983). There were no significant complications. We conclude that both modes of dexmedetomidine administration are equally effective, although increasing age of the child was associated with a decreased likelihood of successful sedation. [ABSTRACT FROM AUTHOR]

Symmetric surface acoustic wave (SAW) atomizer was used to deposit graphene oxide (GO) nanofilms from microdroplets of the aqueous GO dispersion onto the surface of the SAW humidity sensors. The sensors with the deposited GO films were tested in a wide range of relative humidity and showed the amplitude of the response in the range of 1–40 kHz sufficient for the majority of applications. The kinetics of the adsorption of water molecules was modeled using the assumption that two independent first order adsorption processes take place. Saturation amplitudes and rate coefficients for both processes were experimentally evaluated using LSQ fitting of the sensor response in the time domain for the films obtained by different number of depositions. The mechanism of the adsorption of water molecules to the GO flakes is proposed and discussed. [ABSTRACT FROM AUTHOR]

A new micro/nano bubble-modified flame atomic spectrometry has been introduced for promotion of some figures of some merit during determination of metal elements such as Pb(II) and Sn(II) via controlling the stoichiometry of an acetylene/air flame by bubbles generated through sonoelectrochemistry on the surface of nanocarbons such as carbon dots (CDs). For this purpose, the sonoelectrochemical cell is connected to a pre-mixed burner to generate both oxygen and hydrogen micro/nano bubbles during applying direct-current (DC) potential such as +8.00 V (for oxygen) or −8.00 V(for hydrogen) to a two-electrode system including a graphite rod and stainless steel inside a solution of 0.5 M NaCl as electrolyte. According to the results, introduction of each oxygen or hydrogen micro/nano bubbles to the flame atomizer not only has strong influence on controlling the stoichiometry (oxidizing and reducing behavior) and temperature of the flame, but also prevents from flashback of the flame into the pre-mixed burner. Major improvements is also observed in some figures of merit such as linearity, sensitivity, detection limit, and the selectivity during analyses of elements such as Pb(II) or Sn(II) via modification of atomic absorption/emission spectrometry (AAS, AES) with micro/nano bubbles. Generated bubbles also play significant roles like releasing and chelating agents during analysis of Pb(II). Good agreements have been evaluated between bubble-modified AAS and inductively coupled plasma during analyses of Pb(II) in some types of rice samples. [ABSTRACT FROM AUTHOR]

In this paper, a surface-acoustic-wave (SAW)-driven atomizer with micropumps was developed. The micropumps consisted of an epoxy-based reservoir with an exhaust slot and a pair of interdigital transducers (IDTs). The liquid supply from the reservoir was controlled by SAW bursts from the IDTs. A microsurge tank was fabricated into the exhaust slot to stabilize the atomization. The transferred liquid was atomized by a pair of arc-shaped IDTs (AS-IDTs). The AS-IDT was optimally designed using optical vibration observations to focus the SAW energy into a single point and enabled high directional atomization. In the operational test of the micropump with water, a transfer rate of 0.24 pl per single burst was confirmed, where the burst signal is operated at 24.1 MHz with a 50% duty cycle, 40-ms period, and 70~V\mathrm {p-p} amplitude. In the water atomization test, we succeeded in ejecting a narrow mist spray from the substrate using a burst signal operating at 23.8 MHz with a 20% duty cycle, 1-ms period, and 50~V\mathrm {p-p} amplitude. The width of the ejected mist spray was 0.7 mm in the vicinity of the substrate, and was maintained at <1 mm within the ejection height of 8 mm. [2014-0146] [ABSTRACT FROM AUTHOR]

The aim of this research was to determine the influence of atomization degree change on distribution of atomized liquid fall taking place under conditions of airflow of varied speed, and define liquid fall characteristics for different nozzles in variable parameters and conditions such as airflow speed, liquid pressure, and atomization height. The research was done in laboratory conditions in a wind tunnel. The results showed that within the range of the accepted work conditions of the selected nozzles, the greater degree of atomization does not impair the distribution of liquid fall over the atomized area. [ABSTRACT FROM AUTHOR]

The effects of increasing the jet expansion angle, decreasing droplet sizes, and forming a bimodal spectrum of droplets in atomizing superheated liquid by a spray atomizer are discussed. Condensation is adopted to be the mechanism governing the formation of a smaller-size fraction, and atomization enhanced by superheating is adopted to be the mechanism governing the formation of a larger-size fraction. Formulas for calculating the droplet diameter and the jet expansion angle are obtained. It is demonstrated that the calculated and experimentally determined droplet sizes are in satisfactory agreement with each other. [ABSTRACT FROM AUTHOR]

In this article, the effect of geometrical parameters and flow conditions on the performance of a swirl atomizer is studied. A dimensional analysis and experimental investigations are utilized to define significant terms. The PDA system used for the measurements was able to supply information about the size, concentration and particle velocity at each measurement location. The orifice diameter, the spiral cone angle and also the flow Reynolds number, which is defined based on the injector orifice diameter, play an important role in spray quality, and their significance is summarized in a correlation. In order to achieve the appropriate combination of design variables that satisfy the design constraints, a GA-based program was used in a reverse analysis process. Finally, the advantages of human inspection were employed to provide true best performers from a small group of final answers. [ABSTRACT FROM AUTHOR]

We developed a surface acoustic wave (SAW) atomizer, which can produce a narrow mist spray of submillimeter width. The atomized mist spray converges spontaneously and thus requires no additional spray converging system. Key features in achieving the self-converging atomization are two-port interdigital transducers (IDTs) with a groove in between. The SAW is driven by applying an electric field on IDTs patterned on a piezoelectric substrate. The two-port IDTs drive SAWs in opposite directions toward the groove, which then separates the SAW-driven streaming on each side of the groove. Two types of self-converging atomizer were experimentally demonstrated, a line and a point atomizer. While the former uses parallel IDTs to atomize water from the groove into a thin-planar-shaped spray, the latter uses arc-shaped SAW lenses to focus the SAW into a certain point in the groove to atomize water into a narrow point spray. In addition, by adding a water reservoir, continuous operation of up to 30 s was achieved with the submillimeter narrow point atomizer. [ABSTRACT FROM AUTHOR]

A vortex chamber with disk atomizer for use in cooling the circulating water of industrial enterprises is proposed. Studies to determine the optimal number of atomizer disks in order to create a steady spray of circulating water in the work area of the apparatus and to increase the heat and mass exchange efficiency of the process are carried out. [ABSTRACT FROM AUTHOR]

• Experimental values for CD, spray angle and film thickness of a simplex nozzle is obtained using water at four different flow rates. • 2D axisymmetric and full sector 3D VOF simulations are carried out using IDDES turbulence model. • Full benchmark of 2D and 3D methods are done for the accuracy in validation parameters along with the computational cost. • 3D VOF method can provide highly accurate results while 2D method predictions may be used to obtain a general outlook of the flow field with a low cost. • If the inlet slot flow separation behavior is known, 2D method can yield quite satisfying results for the estimation of CD, spray angle and film thickness. In this study, a simplex nozzle is tested with water for the benchmarking of different flow simulation models. A large scale Plexi-glass transparent nozzle is used to reduce the influence of production tolerances on the performance. Experiments are conducted at different flow rates and CD, spray angle and film thickness parameters are evaluated. 2D and 3D hybrid RANS-LES multiphase flow simulations of simplex nozzle are validated against the experimental data. Multiphase nature of the flow is modelled by volume of fluid method. The main goal is to assess the capabilities and drawbacks of 2D axisymmetric and full sector 3D modeling approaches. It is observed that although full sector 3D simulations require HPC cluster systems, accuracies in validation parameters are quite satisfying. Conversely, 2D axisymmetric simulations which can be run on a single core and give a general outlook of the flow field, they show an overshoot of CD and film thickness over the selected range of flow rate. It is shown that this overshoot is mostly related with the inlet boundary condition, which can not take the flow contraction and/or separation at the inlet slots into account. After correcting the inlet velocity 2D simulations by using the 3D results, it is shown that the predictions can be quite close to the experimental data. [ABSTRACT FROM AUTHOR]

Grain size composition, particle surface structure, and gas content in solder powders of the VPr series, prepared by gas jet spraying, grinding of amorphous tape, and melt atomization, are studied. The effect of processing parameters for melting solder billets on gas content in the powder obtained is studied. It is shown that melt atomizing provides preparation of the highest quality powder with a low oxygen content, even for particles with a size of 10-40 μm. It is established that the double vacuum remelting technology developed for an initial solder charge billet makes it possible to reduce oxygen content in the powder obtained by a factor of 2-2.5. It is shown that hot gas atomizing does not lead to a marked increase in oxygen content of the powder obtained, and the nitrogen and sulfur content does not depend on atomizing parameters and is determined by purity of the initial charge billet. [ABSTRACT FROM AUTHOR]

Features of a truck-mounted fogger powered with a steady combustor are high efficiency, low usage, and low cost in control of forestry pest insects and diseases. The structure parameters of its exhausted tube are the key factors to affect oil solvent insecticide to atomize thermodynamically. We studied 3 types of atomizers: ring atomizer, coniform atomizer and column atomizer; 6 location points for the ring atomizer placed inner of the exhausted tube from 250 to 500 mm away from the exit of the exhausted tube; 3 structure parameters of a ring atomizer as jet flow direction of the orifices, orifice number and diameter; 3 jet flow directions as parallel to airflow, to center of pesticide ring and at 45° to airflow direction; 3 different diameters of exhausted-tubes as Φ70, Φ90, and Φ110 mm, which the experiment for atomizing effect was done respectively. The results showed that the ring atomizer was most effective in thermal atomizing; there were the defect phenomena with a coniform atomizer or a column atomizer, such as dropping liquid at the exit of the exhaust tube and combusting flame in the fog. However, the atomizing effect with the coniform atomizer was better than that of the column atomizer. The thermal fogging concentrate can atomize completely to uniform, fine droplets whose size distribution was in a narrow range of 4-6 μm, when the ring atomizer was positioned inner a Φ70 mm exhaust tube and in the range of 250-350 mm away from the exit of the exhaust tube. With the Φ90 mm or Φ110 mm exhausted tube, there were two droplet distribution regions: 4-7 μm for the fine droplet group whose volume ratio to total droplet volume was less than 16%, and 7-226 μm for the coarse droplet group,. The vast majority of coarse droplets could not be completely atomized thermodynamically. The relative span of droplet was only 0.18μm for the Φ70 mm exhaust tube, but were much higher (2.48 and 2.65μm) for the Φ90 and Φ110 mm exhaust tubes respectively. The parameters for a ring atomizer, such as the diameter, number and jet flow direction of the orifices basically did not affect the thermal atomizing performance. Thus, in the process of thermal atomizing for hot fogging concentrate, atomizer type, the exhaust tube diameter, and the position of the atomizer were the main factors influencing the performance of a thermal atomizer. [ABSTRACT FROM AUTHOR]

The aim of this work is to study the parameters affecting on the particle size distribution and shape of Polyethylene wax (PE wax) powders in atomization process. Effect of liquid flow rate, melting temperature and air pressure are studied parameters. External mixing two fluid nozzles is used and temperature is controlled at 200°C to avoid freeze-up within the liquid cap. PE wax is melted at various temperatures from 120°C to 180°C and is atomized with air pressures from 1 to 7 bar. Particle size and size distribution are determined by Particle Sizing Unified System (Mastersizer, 2000). Using 1 bar of air pressure, 140°C of melting temperature and 3.0:1.5 of ALR gives the PE wax powders size that smaller than 200 micron and high bulk density. Moreover, smoothly and silky surface of PE wax powders are obtained. [ABSTRACT FROM AUTHOR]

A series of 50 experiments was performed to investigate particle size and yield from three laboratory spray dryers with two-fluid nozzles, using an aqueous solution of egg albumin as the feed. First principles theory suggests that the main parameters affecting final particle size should be atomization gas flowrate and velocity, feed solution flowrate, solution concentration, and inlet and outlet gas temperature. The experiments demonstrated that atomization gas velocity at the nozzle correlated better than volumetric gas flowrate to the final particle size obtained. Increasing atomization gas flow gave a decrease in particle size, levelling off at high nozzle gas velocities approaching sonic values. Liquid flowrate had little effect, and hybrid ratios such as the ALM (atomization gas to liquid flow ratio) did not correlate well to measured final particle size for this system. This seems likely to apply to aqueous systems with temperature limitations, where liquid flowrates will be relatively low compared to gas flowrates (both atomization and main gas flow). Particle size generally increased with solution concentration, and in some cases scaled exactly, assuming a constant initial droplet size and final particle density. All experiments were performed below the boiling point and therefore temperature had little effect. Particles of 2–3 microns were obtained at high atomization gas flows, indicating initial droplet sizes of 4–7 microns at most, while lower flowrates gave substantially larger particles and a wider size distribution. [ABSTRACT FROM PUBLISHER]

The biggest problems (losses) in sprinkling orchards appear because of drift, especially with young plantations. Presence of drift decreases efficiency of protection measures, indirectly increases using expensive pesticides and causes illegal environmental pollution. The study presents the results of exploitation research of calibrated and precisely adjusted atomiser on application of pesticides of young apple plantation. The application analysed shows data of land and air drift and cover of face and backside of leaf in certain zones of crowns. The researches aim to determine possibilities to save pesticides on the one side and to protect the environment from the aspect of decreasing land that is air drift on the other side. The aim of those researches was to develop appropriate methods for adjusting atomisers with classical axial ventilator in order to make their application good to follow the orchard's needs. The researches have to indicate on possibility of application of small norms in our conditions, what is not the case in accordance to the available data. In addition, the task of the research is to make the application of pesticides in the area of The Srpska Republic closer to completing conditions given by European standards and regulations. By appropriate equipment in accordance with the abovementioned standards, we approached examining the following: pumps, sprinkler, and manometer, the speed of cardan shaft, ventilator capacity and visual control. The results obtained show that only well adjusted; calibrated device can fulfil the conditions of controlled application, application of small norms and so satisfies valid norms and standards. That is also confirmed by the research results which record in many cases irregularity of sets (manometer, sprinklers, pumps, misalignment of ventilator) and from which in great part depend the efficiency of treatment. [ABSTRACT FROM AUTHOR]

Removal of sludges from Wastewater Treatment Plants (WWTP) represents a serious worldwide environmental problem for which alternatives other than their simple incineration are investigated. In this work the treatment of raw sludge from urban WWTP by means of a minimization process through spray-drying is analyzed as well as some proposals for revaluating the resulting dry product. Analysis is supported by some experimental results obtained with a laboratory spray dryer. The experimental procedure at laboratory scale is extrapolated to an industrial plant scale. An economic analysis of the proposal in relation to other possible sludge treatments is presented, taking into account in this case the comparison between the costs of the processes of sludge thickening, stabilization and dehydratation and the costs of spray-drying (especially power consumption), minimization of the final waste and reuse options. Finally, an environmental balance of the process is presented. In contrast with the classical treatment line, this alternative allows transforming sludges, i.e., a waste, into a valuable product with several applications. [Copyright &y& Elsevier]

Abstract: The gas flow fields of four atomizers were analyzed by both k–ɛ turbulence model and Reynolds stress turbulence model (RSM). The scattering angle of the main part of gas spray increased from 15.0° to 17.4° given by k–ɛ model and 17.2° to 19.0° given by RSM model, as the nozzle intersection angle increased from 5° to 65° at the operating gas pressure of 1.0MPa, which also moved the merging position of the annular peak. There is a high pressure area downstream of the delivery tube which contributes to the sheet breakup. Comparing the simulation results with the experimental data, it is found that RSM model is more accurate than k–ɛ model and proved that computational fluid dynamics is an effective method to simulate the gas flow of the close coupled atomizer. [Copyright &y& Elsevier]

Dielectric barrier discharge is a nonequilibrium plasma, and its industrial application has been on a large scale. Similarly, its prominent features of high dissociation ability at low working temperature and low power consumption, simple and adjustable configuration, ambient working conditions, and long lifetime are favorable for developing a wide array of analytical devices as well. This review addresses the basics of dielectric barrier discharge and emphasizes their analytical applications in analytical atomic spectrometry, chemiluminescence, gas chromatographic detectors, ion source for mass spectrometry, and ion mobility spectrometry with 103 references. [ABSTRACT FROM AUTHOR]

The design of the fuel supply system to be used for biofuel is one of the systems that are complicated to design. As this system involves a lot of components, all the components in this design play an important role to ensure that the objective of the system achieved. The purpose of the fuel supply system for gas turbine combustor is to apply the fuel to the combustion chamber through an atomizer to burn and produce 100kW of power. The hollow cone fine spray nozzle, 1.1 mm in diameter was chosen as the atomizer. To evaluate the atomization behavior of palm biofuel blends as an alternative fuels, the physical properties of biofuel blends were determined. These parameters were used to compare the Sauter Mean Diameter (SMD) and the spray cone angle of the various fuel blends. The spray angle of this fuel is around 70 to 84 degrees at pressure around 7 to 9 bars. The main components such as fuel tank, pumps, filters, valves, fuel piping and flow meter had been chosen systematically. This method is used to analyze the components by simulating the real flow process in the fuel system works. Besides that, to test the fuel supply system performance, tests had been conducted using the PDA and the spray characteristics of biofuel was observed. Therefore the characteristics of biofuel such as fuel droplet velocity and size had been obtained from this experimental. [ABSTRACT FROM AUTHOR]

Using the results of numerical modeling of nonstationary gas hydrodynamic working processes in the gas conduit variable section channel when removing and cooling hot gases of different purpose technical plants, an engineering technique has been developed to provide the gas conduit operation under limitations on the flow temperature in the outlet plant section. A multiparametric area of permissible gas conduit operation connecting the characteristics of technical plants, gas conduit and water feeding system is presented. [ABSTRACT FROM AUTHOR]

Spray pyrolysis is a promising aerosol process to produce 'designer particles' of precisely controlled morphology with decorations on surfaces or inside particles. Need of precise control of properties has sparked researches on aerosol process that may replace conventional processes such as solid state reaction process or liquid precipitation method. However, productivity is the biggest obstacle in the development of a commercial scale process because the aerosol process is essentially operated at low particle concentration compared to liquid phase processes. In this review, by reviewing publications for the last 10 years we discuss how researchers on spray pyrolysis circumvent this inherent limitation of the aerosol process. First, the process of particle design by spray pyrolysis is introduced. Some key criteria are explained for selecting each component of spray pyrolysis: precursor, additive, carrier gas, heat source, and reactor type. Second, key contributions of major groups in Korea, Japan, Europe, and America are described. Third, some of named processes to overcome productivity of spray aerosol process are introduced. Fourth, applications of spray pyrolysis to materials related to alternative energy, environmental cleaning, information processing and display, and biomaterials are considered. Finally, future prospects of spray pyrolysis are discussed along with current standing issues for further progress of spray pyrolysis. [ABSTRACT FROM AUTHOR]

The first aim of the work was to evaluate the effect of atomizer design on the properties of solid lipid microparticles produced by spray congealing. Two different air atomizers have been employed: a conventional air pressure nozzle (APN) and a recently developed atomizer (wide pneumatic nozzle, WPN). Milled theophylline and Compritol® 888ATO were used to produce microparticles at drug-to-carrier ratios of 10:90, 20:80, and 30:70 using the two atomizers. The results showed that the application of different nozzles had significant impacts on the morphology, encapsulation efficiency, and drug release behavior of the microparticles. In contrast, the characteristics of the atomizer did not influence the physicochemical properties of the microparticles as differential scanning calorimetry, Hot Stage microscopy, X-ray powder diffraction, and Fourier transform infrared spectroscopy analysis demonstrated. The drug and the lipid carrier presented in their original crystalline forms in both WPN and APN systems. A second objective of this study was to develop a novel mathematical model for describing the dynamic process of drug release from the solid lipid microparticles. For WPN microparticles the model predicted the changes of the drug release behavior with particle size and drug loading, while for APN microparticles the model fitting was not as good as for the WPN systems, confirming the influence of the atomizer on the drug release behavior. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:916–931, 2010 [ABSTRACT FROM AUTHOR]

Abstract: An atmospheric pressure dielectric barrier discharge (DBD) atomizer was investigated for bismuth (Bi) determination with hydride generation (HG) atomic fluorescence spectrometry (AFS). The characteristics of the atomizer and the effects of experimental parameters, including observation height, discharge power, flow rate of discharge gas and AFS carrier gas were optimized. The linear range of present method for Bi determination is 0.5–300.0μgL−1 with a detection limit of 0.07μgL−1 (3σ). The method was validated by the analysis of reference materials (GBW08517 and GSB-14) and the results agreed well with the reference values. The established method was applied to the determination of Bi in ore, soil and ash samples. [Copyright &y& Elsevier]

Before performing transnasal fiberscopy to observe the nasal cavity, pharynx and larynx in outpatient clinics, nasal anesthetics and vasoconstrictive agents are routinely sprayed into the nares in order to improve patients' comfort. Bacterial contamination of the nozzles of Venturi principle atomizer barrels and their solutions after being used for multiple patients over a long-term period without cleaning is controversial. We evaluated the potential risk of atomizer-associated cross-infection by using atomizers commonly available in Japan that use compressed air to atomize medication. Eighteen of the 23 samples (78.3%) from the external nozzle tips of the atomizers resulted in positive bacterial cultures. These detected bacteria are suggested to be colonized in the nares and to cause bacterial contamination of the atomizer. Of the 25 samples obtained from the spray of the drug solutions, 11 samples showed positive bacterial culture, whereas 16 control samples produced no growth of bacteria. The present study demonstrated that the atomizer widely used in the outpatient ENT clinics in Japan has a potential risk of causing cross-infection of patients. [ABSTRACT FROM AUTHOR]

The focus of the present paper is to understand the large scale unsteadiness in the atomization of swirl coaxial jets and correlate it with the downstream spray statistics. A gas-centered swirl coaxial atomizer, in which a gaseous jet fragments an annular swirling liquid sheet, displays pulsating flow at certain momentum flux ratios (MFRs). These conditions were chosen to study the unsteady dynamics in the spray formation. Various zones of the spray such as near orifice region, primary atomization zone and far field spray were diagnosed using high-speed shadowgraphy technique. Proper orthogonal decomposition was employed on the time-resolved spray images to understand various unsteady modes. Three modes observed prominently were identified as large scale unsteady structures viz. axisymmetric pulsating mode, explosive mode and swirling mode. The pulsating mode was found to be more dominant in the pulsation regime, whereas the other modes gained significance at higher MFRs when the pulsation regime ceases to exist. Fourier analysis of temporal coefficients pertaining to pulsating mode showed a definitive frequency. The analysis of liquid shedding rate was found to be in synchronization with the pulsating mode which shows the upstream influence on periodic atomization. Spatio-temporal measurements of droplet sizes were carried out far from the atomizer. The temporal variation in the droplet number density and Sauter Mean Diameter depicted unsteady behavior; however, there is no preferred frequency in the power spectrum. This clearly indicates that the far field spray loses its memory of upstream periodic atomization in the pulsation regime of swirl coaxial atomizer. • The primary unsteady modes in a GCSC injector: pulsating, explosive & swirling mode. • Pulsating mode governs the pulsation regime, while other modes dominate at high MFRs. • Liquid shedding synchronizes with the pulsating mode with low-frequency influence. • Far field spray statistics loses the memory of the upstream periodic pulsation. [ABSTRACT FROM AUTHOR]

Abstract: Flame-in-gas shield miniature hydride atomizers (FIGS) have been investigated and evaluated in view of their alternative use to miniature diffusion flame hydride atomizer (MDF) to determination of hydride forming elements by atomic fluorescence spectrometry (AFS). Chemical vapour generation (CVG) by aqueous phase derivatization by NaBH4 in a continuous flow generator (CF) was employed for the generation of volatile hydrides of As, Sb, Bi, Se, Te and Sn. A dispersive AFS apparatus using electrodeless discharge lamps (EDL) as the excitation sources has been employed for both spectra acquisition and analytical determinations. The characteristics of FIGS in terms of background emission spectra, most intense AF spectral lines and limits of detection were compared with those of most popular MDF. FIGS presents a lower background emission with respect to MDF, allowing also the control of the molecular fluorescence of OH radicals in the determination of bismuth. Limits of detection for FIGS compare very well with to those obtained by MDF giving improvement factor of 5.5, 4.4, 3.6, 3.6, 0.7 an 0.5 for Bi, As, Se, Son, Te and Sb. Accuracy of FIGS has proven by determination of arsenic and antimony in seawater (NASS-5) and river water (SRLS-4) certified reference materials and bismuth in unalloyed copper (CuV 398, CuVI 399) standard reference materials by dispersive CVG-AFS. [Copyright &y& Elsevier]

The movement mode of the atomizer is a very important parameter during spray deposition process, which has direct influence on the size and surface texture of the billets. To resolve the problem of manufacturing large size billets, a method of spray deposition by the atomizer with off-center swing was put forward. The atomizer was driven by the alternating current servomotor to swing within 7° at varying speed. The influence of the atomizer parameters, such as translation of the atomizer, swing angle of the atomizer, substrate falling speed and spraying pressure, on the spray deposition was studied. The optimized parameters of the spray deposition process were obtained. The results show that the large size billets with uniform surface quality can be made through adjusting swing frequency and angle of the atomizer, offset distance of the atomizer and inclined angle of the substrate; the valid spray area will decrease and the dimension of top surface will reduce when pressure is less than 0.4 MPa within certain spray distance; meantime, the moving time and cooling time of the droplets are extended, which will lead to loose structure and bad densification. When the pressure, the swing angle and the eccentric offset of the atomization equal 0.5 MPa, 7° and 60 mm, respectively, large size billets with fine texture and diameter of 500 mm can be produced. [ABSTRACT FROM AUTHOR]

Abstract: In this study, we have developed an odor sensing system using an array of ball SAW devices and pattern recognition technique. High sensitivity can be expected since SAW propagation length utilized for sensing is long due to multiple round trips in spite of its small size. An atomizer was used to realize uniform coating over a ball SAW device. The experiment on discrimination among apple, pineapple and orange flavors was successfully performed using four ball SAW devices coated with different films even if the sensor array was exposed to odors with different concentrations. Moreover, the change of the attenuation loss due to odor adsorption was measured together with its phase change. The change of the attenuation loss enhanced the pattern separation in some cases. [Copyright &y& Elsevier]

Abstract: A flameless atomizer for atomic fluorescence spectrometry (AFS), based on an atmospheric pressure dielectric barrier discharge, has been developed for the atomization of hydride-forming elements, such as Se, Sb and Pb. The atomizer (8 mm o.d, 35 mm length) was operated at a power less than 50 W. The discharge was sustained with argon at the flow rate of 0.85 L min−1 after optimization. The characteristics of the atomizer and the effects of different parameters (power, gas flow rate, and KBH4 concentration) are investigated. The most attractive feature of this atomizer is its low operation temperature (~52 °C, detected at the outlet of the atomizer by a thermocouple), allowing both the radiation source and the detector to be placed in close proximity with the atomizer. The analytical performance of the atomizer has been evaluated, and detection limits for Se, Sb and Pb obtained with the present technique were 0.08, 0.11 and 0.27 μg L−1, respectively. The accuracy of the system was verified by the determination of Se, Sb and Pb in reference material of spinage GBW 10015. The concentrations of Se, Sb, and Pb determined by the present technique agreed well with the reference values (Se: 92±24 mg kg−1, Sb: 43±14 mg kg−1, Pb: 11.1±0.9 mg kg−1). This detector is very promising for field elements detection with portable AFS. [Copyright &y& Elsevier]

Abstract: A new atomizer based on atmospheric pressure dielectric barrier discharge (DBD) plasma was specially designed for atomic fluorescence spectrometry (AFS) in order to be applied to the measurement of arsenic. The characteristics of the DBD atomizer and the effects of different parameters (power, discharge gas, gas flow rate, and KBH4 concentration) were discussed in the paper. The DBD atomizer shows the following features: (1) low operation temperature (between 44 and 70°C, depending on the operation conditions); (2) low power consumption; (3) operation at atmospheric pressure. The detection limit of As(III) using hydride generation (HG) with the proposed DBD-AFS was 0.04μgL−1. The analytical results obtained by the present method for total arsenic in reference materials, orchard leaves (SRM 1571) and water samples GBW(E) 080390, agree well with the certified values. The present HG-DBD-AFS is more sensitive and reliable for the determination of arsenic. It is a very promising technique allowing for field arsenic analysis based on atomic spectrometry. [Copyright &y& Elsevier]

Spray drying is a widely used unit operation for manufacturing powders of different characteristics. Many technological improvements have been made in the last few decades, and a great amount of research work is still being conducted. Recently, the hybrid spray-drying technique was reported, which combines the ink-jet technology with spray drying in order to produce particles of uniform characteristics.[1-41, 2, 3, 4] The monodisperse droplet generators (MDGs) have certain features that make them attractive for use as atomizers in spray-drying operations. In this article, a comprehensive introduction to a variety of monodisperse droplet generators is provided. The advantages and limitations of these generators are discussed. The fundamental equations for predictions of the average droplet size are summarized. The discussion given in this study is aimed at the development of a hybrid technology that marries a suitable MDG with the existing spray-dryer technique (yet with some modifications) to manufacture the product with uniform characteristics containing micro- to nanosized particles. [ABSTRACT FROM AUTHOR]

Abstract: A scaled gas humidification system using injectors for PEM fuel cell vehicles was developed and the humidification performance was evaluated under various operating conditions. The humidification system consists of an injector, a duplex enthalpy mixer and a water management apparatus. A dew point meter of the chilled mirror type was used to measure the humidity of the air and the hydrogen. Humidification performance was evaluated by measuring the dew point temperature of the humidified gases. Humidification performance was observed to be critically affected by the temperature of injected water and the gas flow rate in this study. The dew point of the humidified gas rose when the temperature of injected water increased, however, it dropped when the gas flow rate was increased. Experimental results show that the outlet temperature was 58.4°C, dew point temperature of the humidified air reached 54.0°C when the injection water temperature was 69.5°C with the room temperature air flow rate of 200Lmin−1. Inlet gas temperature also affected the humidification performance and response time. In addition, a 50cm2 PEM fuel cell was tested to verify the effectiveness of the devised humidifier. When operated at 65°C, the fuel cell showed an operating voltage of 0.5V at a current density of 600mAcm−2. [Copyright &y& Elsevier]

Abstract: This paper presents the design, fabrication and testing of a PZT bimorph actuated atomizer. The atomizer with the size of 43mm×37mm×7mm is composed of a PZT bimorph actuator, which is sandwiched by top and bottom flow channel plates and cover shields. The micronozzle plate is attached onto the top cover shield. UV laser machining and micro electrical discharge machining (μEDM) are applied to fabricate the micronozzles with different geometry. The experimental results indicate that we can justify the frequency response of flow rate by acoustic pressure analysis. The peak flow rates occur at higher order resonances, and the operating pressure is less than 0.1MPa, which is much lower than that of existing atomizers. Also, the influence of flow rate by changing the distance between the PZT bimorph and the nozzle plate, as well as the flat plate on the bottom cover shield are discussed. The maximum flow rate of 8ml/min is obtained by using the μEDM-made micronozzle plate, when the atomizer is driven with square pulses at 7kHz with 50% duty cycle and 27V peak-to-peak. [Copyright &y& Elsevier]

The flammability characteristics of jet fuel aerosols are critical to the development of fire-safe fuels. In efforts to design and characterize fire-safe fuels, an automated rotary atomizer has been constructed to produce fuel aerosols and measure their mist flammability properties. A particle analyzer has been coupled directly to the atomizer to provide drop size distribution information on the aerosols. The size distribution measurements provide crucial evidence regarding the droplet formation mechanism of the constructed atomizer. This paper focuses on the evaluation of water aerosols as a function of disk speed, flow rate to the atomizer, and liquid surface tension utilizing this instrumental design. [ABSTRACT FROM AUTHOR]