排序方式: 共有36条查询结果,搜索用时 203 毫秒
21.
Miloud Kachi Mohamed Nemamcha Herous Lazhar Lucien Dascalescu 《Journal of Electrostatics》2011,69(4):296-301
The control of the residual electric charge carried by granular materials processed in various electrostatic installations is a prerequisite for the safe and efficient operation of the respective industrial equipment. The aim of the present work was to evaluate the neutralization efficiency of polyethylene granules exposed to an AC corona discharge from a wire-type electrode. The control variables and their domains of variations were the following: the amplitude and the frequency of the applied high voltage (16–18 kV, 20–400 Hz), the position of the corona electrode (3–7 cm above the ground plate that carries the sample) and the duration of the exposure to the corona discharge (4–10 s). The surface potential decay method was used for monitoring the charge carried by granular samples of PE before and after neutralization. Design of experiment methodology was employed to evaluate the influence of each of the above mentioned control variables and determine the optimum operation conditions. The efficiency of the neutralization was characterized by the ratio between the values of the surface potential before and after AC corona discharge exposure. The obtained results show that neutralization efficiency may be improved by increasing the frequency of the high voltage as well as by adequately correlating its amplitude with the inter-electrode spacing. 相似文献
22.
Hajji L Saraiba-Bello C Romerosa A Segovia-Torrente G Serrano-Ruiz M Bergamini P Canella A 《Inorganic chemistry》2011,50(3):873-882
The new water-soluble ruthenium(II) mononuclear complexes [RuCp(X)(PTA)(L)] (X = 8-thio-theophyllinate (TTH(-)), L = PTA (1), L = PPh(3) (7)); (X = 8-methylthio-theophyllinate (8-MTT(-)), L = PTA (2), L = PPh(3) (8)), (X = 8-benzylthio-theophyllinate (8-BzTT(-)), L = PTA (3), L = PPh(3) (9)) and binuclear complexes [{RuCp(PTA)(L)}(2)-μ-(Y-κN7,N'7)] (Y = bis(S-8-thiotheophyllinate)methane (MBTT(2-)), L = PTA (4), L = PPh(3) (10)), (Y = 1,2-bis(S-8-thiotheophyllinate)ethane (EBTT(2-)), L = PTA (5), L = PPh(3) (11)), (Y = 1,3-bis(S-8-thiotheophyllinate)propane (PBTT(2-)); L = PTA (6), L = PPh(3) (12)) have been synthesized and characterized by NMR, IR spectroscopy and elemental analysis. The single crystal X-ray structure of [RuCp(8-MTT-κS)(PTA)(2)] (2) was also obtained. The antiproliferative activity of the complexes on cisplatin-sensitive T2 and cisplatin-resistant SKOV3 cell lines has been evaluated. 相似文献
23.
This paper studies a boundary value problem with nonlocal conditions for a coupled system of linear thermoelasticity in one-dimensional case. Using an a priori estimate, we prove the uniqueness of the solution. Also, some explicit solutions are obtained by using the separation method. 相似文献
24.
Lazhar Herous Mohamed Nemamcha Mokdad Remadnia Lucian Dascalescu 《Journal of Electrostatics》2009,67(2-3):198-202
The initial potential at the surface of the sample, as well as the temperature and the relative humidity of the ambient air are known to influence the surface-potential decay characteristics of corona-charged thin insulating films. The aim of the present work is to demonstrate the effectiveness of the Experimental Design methodology for evaluating the effects of these factors. Thus, a full factorial experimental design was carried out on a thin film of polyethylene terephthalate (thickness: 0.5 mm; surface: 50 mm × 50 mm). A negative corona discharge produced in a needle–grid–plate electrode system was employed to charge the surface of the film samples. The variation domains for the three factors were respectively: ?1000 V to ?1800 V; 25 to 55 °C; 50% to 80%. The surface-potential decay process was characterized by two output variables: the time needed for the potential to reduce to respectively 50% and 10% of the initial value. It was found that the former is more affected by the temperature, while the latter is more sensitive to the variation of the relative humidity. 相似文献
25.
The evolution of a spherical gaseous interface accelerated by a plane weak shock wave has been investigated in a square cross section shock tube via a multiple exposure shadowgraph diagnostic. Different gaseous bubbles, i.e., helium, nitrogen, and krypton, were introduced in air at atmospheric pressure in order to study the Richtmyer-Meshkov instability in the spherical geometry for negative, close to zero, and positive initial density jumps across the interface. We show that the bubble distortion is strongly different for the three cases and we present the experimental velocity and volume of the developed vortical structures. We prove that at late times the bubble velocities reach constant values which are in good agreement with previous calculations. Finally, we point out that, in our flow conditions, the gaseous bubble motion and shape are mainly influenced by vorticity and aerodynamic forces. 相似文献
26.
We investigated the deformation of a strong shear thinning droplet undergoing simple shear flow in a Newtonian liquid. The
droplet was an aqueous solution of poly(ethylene oxide) end capped with an alkyl group that forms spherical micelles in aqueous
solution. At high concentrations and below a critical temperature, the jammed micelles showed strong shear thinning behaviour,
and neither a yield stress nor a Newtonian viscosity was observed. At small shear rates, the droplet rotated and aligned in
the flow, but did not deform or only very weakly. At high shear rates, the droplet deformation increased with increasing shear
rate. The deformed droplet did not relax after the shear was stopped except for a modest rounding of the edges. For each shear
rate, an apparent viscosity, η
ad, of the equivalent Newtonian droplet was calculated assuming affine deformation. η
ad showed a power law dependence on the capillary number Ca with an exponent of − 1.8 and was larger than the shear viscosity
of the micelle suspension at the same shear rates. The results were explained by the existence of a strong gradient of the
viscosity inside the droplet leading to a very low viscosity fluid layer near the droplet/matrix interface. 相似文献
27.
Lazhar Bougoffa 《Applied mathematics and computation》2010,216(2):689-8913
The Abel equation of the second kind
[g0(x)+g1(x)u]u′=f0(x)+f1(x)u+f2(x)u2 相似文献
28.
We present a direct method for finding particular solutions of equations of sine-Gordon type, including single sinh-Gordon equation, single sine-Gordon equation, double sinh-Gordon and double sine-Gordon equations. 相似文献
29.
After the analysis of the q-even translation and the q-cosine Fourier transform by A. Fitouhi and F. Bouzeffour in [q-cosine Fourier transform and q-heat equation, Ramanujan J., in press], it is natural to look for the q-analogue of some well-known classical theorems. In this paper, we purpose to give a q-version of the Paley-Wiener theorem related to this Fourier transform using standard methods of the q-calculus. 相似文献
30.
Facile one-pot synthesis of new [1,2,4]triazolo[1,5-a]pyridine derivatives by ultrasonic irradiation
Herein, we report an ultrasonic promoted facile and convenient “one-pot” procedure for the synthesis of new [1,2,4]triazolo[1,5-a]pyridine derivatives 3, 4 and 5, using Amberlite IRA-400, in short reaction times and high yields and its comparison with classical reaction conditions. The structures of new compounds were assigned with the help of analytical 1H, 13C NMR, and mass spectral studies. 相似文献