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1.
Applied Intelligence - With the rapid advancement in network technologies, the need for cybersecurity has gained increasing momentum in recent years. As a primary defense mechanism, an intrusion... 相似文献
2.
Farouk M. Slibi Dhia-Aldin Abd El-Fattah Z. M. Atallah M. El-Sherbiny M. A. Hassan Moukhtar A. 《SILICON》2021,13(9):3003-3010
Silicon - Melt-quenching technique was used to prepare borosilicate glasses of composition xSiO2- (75-x) B2O3–24.7Li2O-0.3Cr2O3 (x = 0, 10, 20, 30, 40 and 50 mol%). With... 相似文献
3.
M. F. El-Sherbiny A. A. Zatout M. Hussien G. H. Sedahmed 《Journal of Applied Electrochemistry》1991,21(6):537-542
Mass transfer coefficients for an oxygen evolving vertical PbO2 coated cylinder electrode were measured for the anodic oxidation of acidified ferrous sulphate above the limiting current. Variables studied included the ferrous sulphate concentration, the anode height, the oxygen discharge rate and the anode surface roughness. The mass transfer coefficient was found to increase with increasing O2 discharge rate,V, and electrode height,h, according to the proportionality expressionK V
0.34
h
0.2. Surface roughness with a peak to valley height up to 2.6 mm was found to increase the rate of mass transfer by a modest amount which ranged from 33.3 to 50.8% depending on the degree of roughness and oxygen discharge rate. The present data, as well as previous data at vertical oxygen evolving electrodes where bubble coalescence is negligible, were correlated by the equationJ=7.63 (Re. Fr)–0.12, whereJ is the mass transferJ factor (St. Sc
0.66).Notation
a
1,a
2
constants
-
A
electrode area (cm2)
-
C
concentration of Fe2+ (M)
-
d
bubble diameter (cm)
-
D
diffusivity (cm2 s–1)
-
e
electrochemical equivalent (g C–1)
-
F
Faraday's constant
-
g
acceleration due to gravity (cm s–2)
-
h
electrode height (cm)
-
I
Fe
2+
current consumed in Fe2+ oxidation A
-
I
o
2
current consumed in O2 evolution, A
-
K
mass transfer coefficient (cm s–1)
-
m
amount of Fe2+ oxidized (g)
-
P
gas pressure (atm)
-
p
pitch of the threaded surface (cm)
-
Q
volume of oxygen gas passing any point at the electrode surface (cm3 s–1)
-
R
gas constant (atm cm3 mol–1 K–1)
-
r
peak-to-valley height of the threaded surface (cm)
-
t
time of electrolysis (s)
-
T
temperature (K)
-
solution viscosity (g cm–1 s–1)
-
V
oxygen discharge velocity as defined by Equation 3 (cm s–1)
-
Z
number of electrons involved in the reaction
-
Sh
Sherwood number (Kd/D)
-
Re
Reynolds number (Vd/)
-
Sc
Schmidt number (v/D)
-
J
mass transferJ factor (St. Sc
0.66)
-
St
Stanton number (K/V)
-
Fr
Froude number (V
2/dg)
-
Solution density, g cm–3
-
v
Kinematic viscosity (cm2 s–1)
-
bubble geometrical parameter defined in [31]
-
fractional surface coverage
-
diffusion layer thickness (cm) 相似文献
4.
Ali B. Alamin Dow Adel Gougam Nazir P. Kherani I. W. Rangelow 《Microsystem Technologies》2014,20(4-5):955-961
The current work reports on the realization of movable micromachining devices using self-aligned single-mask fabrication process. Only dry etching process utilizing inductively coupled plasma reactive ion etching was used to release 3D micro structures from single crystal silicon substrate. No wet etching process is required to release the structures as is the case with silicon on insulator (SOI) wafers. Also the developed process does not require an SOI substrate and accordingly dispensing with the application of a wet etching step, thus yielding uniform structures without stiction. The optimized process was applied to realize thermally actuated microgrippers. The article presents the development of the fabrication process and demonstrates the operation of the fabricated device. The optimized process provides an avenue for low cost fabrication of movable micromachining devices without the use of complicated wet etching steps typically associated with SOI substrates. 相似文献
5.
Adel Al Rai Elena Stojanovska Yasin Akgul Mohammad Mansoob Khan Ali Kilic Safak Yilmaz 《应用聚合物科学杂志》2021,138(7):49835
Highly porous free-standing co-poly(vinylidene fluoride)/modacrylic/SiO2 nanofibrous membrane was developed using electrically-assisted solution blow spinning method. The performance and the potential of the membrane as a lithium-ion battery separator were investigated. The addition of modacrylic enhanced the solution spinnability that resulted in defect-free membranes. Moreover, the presence of modacrylic enhanced the dimensional and thermal stabilities, while the addition of hydrophilic SiO2 nanoparticle enhanced both mechanical property and ionic conductivity. Combustion test results illustrated that the presence of modacrylic provide flame retarding property over a set of different polymeric-based membranes. Electrochemical performance results showed that the developed membrane can increase the battery capacity compared with the commercial separator. 相似文献
6.
Bounouni Mahdi Bouallouche-Medjkoune Louiza Beraza Abderrahmane Daoud Adel 《Wireless Personal Communications》2022,123(4):3291-3308
Wireless Personal Communications - In this paper, we propose a new reputation approach, called I-WD (improved WatchDog). We attempt to eliminate selective dropping attack that ensue when malicious... 相似文献
7.
We present two new classifiers for two-class classification problems using a new Beta-SVM kernel transformation and an iterative
algorithm to concurrently select the support vectors for a support vector machine (SVM) and the hidden units for a single
hidden layer neural network to achieve a better generalization performance. To construct the classifiers, the contributing
data points are chosen on the basis of a thresholding scheme of the outputs of a single perceptron trained using all training
data samples. The chosen support vectors are used to construct a new SVM classifier that we call Beta-SVN. The number of chosen
support vectors is used to determine the structure of the hidden layer in a single hidden layer neural network that we call
Beta-NN. The Beta-SVN and Beta-NN structures produced by our method outperformed other commonly used classifiers when tested
on a 2-dimensional non-linearly separable data set. 相似文献
8.
Amir H. Shokouhi Adel Hatami-Marbini Madjid Tavana Saber Saati 《Computers & Industrial Engineering》2010
Crisp input and output data are fundamentally indispensable in traditional data envelopment analysis (DEA). However, the input and output data in real-world problems are often imprecise or ambiguous. Some researchers have proposed interval DEA (IDEA) and fuzzy DEA (FDEA) to deal with imprecise and ambiguous data in DEA. Nevertheless, many real-life problems use linguistic data that cannot be used as interval data and a large number of input variables in fuzzy logic could result in a significant number of rules that are needed to specify a dynamic model. In this paper, we propose an adaptation of the standard DEA under conditions of uncertainty. The proposed approach is based on a robust optimization model in which the input and output parameters are constrained to be within an uncertainty set with additional constraints based on the worst case solution with respect to the uncertainty set. Our robust DEA (RDEA) model seeks to maximize efficiency (similar to standard DEA) but under the assumption of a worst case efficiency defied by the uncertainty set and it’s supporting constraint. A Monte-Carlo simulation is used to compute the conformity of the rankings in the RDEA model. The contribution of this paper is fourfold: (1) we consider ambiguous, uncertain and imprecise input and output data in DEA; (2) we address the gap in the imprecise DEA literature for problems not suitable or difficult to model with interval or fuzzy representations; (3) we propose a robust optimization model in which the input and output parameters are constrained to be within an uncertainty set with additional constraints based on the worst case solution with respect to the uncertainty set; and (4) we use Monte-Carlo simulation to specify a range of Gamma in which the rankings of the DMUs occur with high probability. 相似文献
9.
10.
In this paper, we present a unified general inventory model for integrated production of new items and remanufacturing of returned items for an infinite planning horizon. Our model considers a production environment that consists of three shops. The first shop is for remanufacturing returned items, the second shop is for manufacturing new items, while the third shop is for collecting returned items to be remanufactured in the first shop. The system is subject to joint production and remanufacturing options, the first one is to produce new items while the second one is to reproduce/recycle the returned items “as-good-as new”. Items deteriorate while they are in storage, and production, remanufacturing, demand, return, and deterioration rates are arbitrary functions of time. A closed form for the total relevant costs as well as a rigorous mathematical proof, which shows the global optimality of the solution to the underlying inventory system are introduced. Illustrative examples, which explain the application of the theoretical results as well as their numerical verifications, are also given. 相似文献