OALib Journal期刊

ISSN: 2333-9721




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匹配条件: “Moieza Ashraf” ,找到相关结果约1319条。
Physico-Chemical Characteristics of the Grassland Soils of Yusmarg Hill Resort (Kashmir, India)
Moieza Ashraf,G. A. Bhat,Idrees Yousuf Dar,Mudasir Ali
Ecologia Balkanica , 2012,
Abstract: Physico-chemical analysis was carried out on the grassland soils of Yusmarg Hill Resort, Kashmir during the months of May, June, November and December 2010, at four micro sites with some minor variations in the abiotic and biotic factors including anthropogenic pressures. The following soil characteristics were examined: temperature, texture, moisture, organic matter, pH, and conductivity, content of calcium, magnesium, sodium, potassium, total phosphorus, and organic carbon. Soil texture analysis revealed the soils at all the study sites with major proportion being comprised by the sand fraction and having a sandy silt character. The moisture content was found to be directly related to the herbaceous vegetation cover with the highest value at Site 3 (fenced meadow area). The moisture content showed low percentage at Site 2, which was more affected by grazing and thus resulted in less cover of grasses and probably more evaporation of soil moisture from the exposed site. The soils at all sites were from acidic to mildly acidic in character. The amount of organic matter was fairly good except at Site 2 (non-fenced grazing area) probably due to overgrazing during which much of herbage vegetation was picked up by the grazing animals like sheep and cattle. The values of important cations, such as Ca2+ and Mg2+, showed a gradual decrease from May to December except at Site 4 (transition between a coniferous forest and a meadow) which may be attributed to a good cover of vegetation and good amount of organic matter.
Prediction of Future Configurations of a Moving Target in a Time-Varying Environment Using an Autoregressive Model  [PDF]
Ashraf Elnagar
Intelligent Control and Automation (ICA) , 2011, DOI: 10.4236/ica.2011.24033
Abstract: In this paper, we describe an algorithm for predicting future positions and orientation of a moving object in a time-varying environment using an autoregressive model (ARM). No constraint is placed on the obstacles motion. The model addresses prediction of translational and rotational motions. Rotational motion is represented using quaternions rather than Euler representation to improve the algorithm performance and accuracy of the prediction results. Compared to other similar systems, the proposed algorithm has an adaptive capability, which enables it to predict over multiple time-steps rather than fixed ones as reported in other works. Such algorithm can be used in a variety of applications. An important one is its application in the framework of designing reliable navigational systems for autonomous mobile robots and more particularly in building effective trajectory planners. Simulation results show how significantly this model could reduce computational cost.
Efficacy and Toxicity of Metronomic Capecitabine in Advanced Hepatocellular Carcinoma  [PDF]
Ashraf Farrag
Journal of Cancer Therapy (JCT) , 2012, DOI: 10.4236/jct.2012.31010
Abstract: Background: Hepatocellular carcinoma (HCC) is a hypervascular tumor. Metronomic chemotherapy; the continuous administration of low-dose chemotherapy; has both cytotoxic and antiangiogenic effects with low toxicity profile. We evaluated the efficacy and toxicity of metronomic capecitabine (MC) in patients with advanced HCC. Patients and Methods: From May 2010, we enrolled pts with either metastatic or locally advanced diseases not candidate for ablative or locoregional treatment and have acceptable liver function. Patients received oral MC in dose of 1000 mg/m2 daily in a 21 days cycle without interruption till disease progression or toxicity. Results: The study cohort consisted of 22 patients with a median age of 63 years. The median number of cycles received was 3 cycles (range 1 - 9). From 19 patients were evaluable for response we had 3 partial responders, 10 stable diseases and disease progression in 6 patients. Median time to progression (TTP) was 2.2 months (95% CI 1.4 - 6.24) and median survival time (OS) was 4.8 months (95% CI 1.8 - 7.9). For 20 patients evaluable for safety: no grade III/IV hematological toxic effects were observed. Non-hematological toxic effects included grade III vomiting and diarrhea in one patient and grade III hand-foot syndrome in one patient. There was no treatment-related mortality. Conclusions: Based on the observed response rate, TTP and OS; MC has a modest antitumor efficacy in pts with advanced HCC. However, due to its low toxicity profile it deserves further attention as a convenient, outpatient-based chemotherapy regimen.
A Robust Incremental Algorithm for Predicting the Motion of Rigid Body in a Time-Varying Environment  [PDF]
Ashraf Elnagar
International Journal of Intelligence Science (IJIS) , 2012, DOI: 10.4236/ijis.2012.23007
Abstract: A configuration point consists of the position and orientation of a rigid body which are fully described by the position of the frame’s origin and the orientation of its axes, relative to the reference frame. We describe an algorithm to robustly predict futuristic configurations of a moving target in a time-varying environment. We use the Kalman filter for tracking and motion prediction purposes because it is a very effective and useful estimator. It implements a predictor-corrector type estimator that is optimal in the sense that it minimizes the estimated error covariance. The target motion is unconstrained. The proposed algorithm may be viewed as a seed for a range of applications, one of which is robot motion planning in a time-changing environment. A significant feature of the proposed algorithm (when compared to similar ones) is its ability to embark the prediction process from the first time step; no need to wait for few time steps as in the autoregressive-based systems. Simulation results supports our claims and demonstrate the superiority of the proposed model.
Magnetized Water and Memory Meter  [PDF]
Ashraf Kotb
Energy and Power Engineering (EPE) , 2013, DOI: 10.4236/epe.2013.56045
Abstract: This paper presents an experimental study to investigate the effect of using the magnetic water conditioner on the properties of water. The water flows through a closed loop, while the pH, TDS, and hardness represent its properties. For magnetic water conditioner with flux density of 170 mT, results showed that pH increased by 15.65% for 820 minutes of non-stop circulation. The increase in pH is divided to 93.5% for the first 360 minutes, and 6.5% for the last 460 minutes. TDS and Hardness of water are not affected by the magnetic water conditioner. Water remembers and keeps the impact of passing through the magnetic field for several hours, and pH decreased by 0.642 in24 hours. While the results lead to introduce and create the magnetized water saturation curve and water memory meter.
Rotating Variable-Thickness Inhomogeneous Cylinders: Part I—Analytical Elastic Solutions  [PDF]
Ashraf M. Zenkour
Applied Mathematics (AM) , 2010, DOI: 10.4236/am.2010.16063
Abstract: In this paper, an analytical solution for the rotation problem of an inhomogeneous hollow cylinder with variable thickness under plane strain assumption is developed. The present cylinder is made of a fiber-reinforced viscoelastic inhomogeneous orthotropic material. The thickness of the cylinder is taken as parabolic function in the radial direction. The elastic properties varies in the same manner as the thickness of the cylinder while the density varies according to an exponential law form. The inner and outer surfaces of the cylinder are considered to have combinations of free and clamped boundary conditions. Analytical solutions are given according to different types of the hollow cylinders. An extension of the present solutions to the viscoelastic ones and some applications are investigated in Part II.
Rotating Variable-Thickness Inhomogeneous Cylinders: Part II—Viscoelastic Solutions and Applications  [PDF]
Ashraf M. Zenkour
Applied Mathematics (AM) , 2010, DOI: 10.4236/am.2010.16064
Abstract: Analytical solutions for the rotating variable-thickness inhomogeneous, orthotropic, hollow cylinders under plane strain assumption are developed in Part I of this paper. The extensions of these solutions to the viscoelastic case are discussed here. The method of effective moduli and Illyushin's approximation method are used for this purpose. The rotating fiber-reinforced viscoelastic homogeneous isotropic hollow cylinders with uniform thickness are obtained as special cases of the studied problem. Numerical application examples are given for the dimensionless displacement of and stresses in the different cylinders. The influences of time, constitutive parameter and elastic properties on the stresses and displacement are investigated.
High Accuracy Time of Flight Measurement Using Digital Signal Processing Techniques for Subsea Applications  [PDF]
Muhammad Ashraf, Hamza Qayyum
Journal of Signal and Information Processing (JSIP) , 2011, DOI: 10.4236/jsip.2011.24047
Abstract: The techniques widely used in ultrasonic measurements are based on the determination of the time of flight (T.o.F). A short train of waves is transmitted and same transducer is used for reception of the reflected signal for the pulse-echo measurement applications. The amplitude of the received waveform is an envelope which starts from zero reaches to a peak and then dies out. The echoes are mostly detected by simple threshold crossing technique, which is also cause of error. In this paper digital signal processing is used to calculate the time delay in reception i.e. T.o.F, for which a maximum similarity between the reference and the delayed echo signals is obtained. To observe the effect of phase uncertainties and frequency shifts (Doppler), this processing is carried out, both directly on the actual wave shape and after extracting the envelopes of the reference and delayed echo signals. Several digital signal processing algorithms are considered and the effects of different factors such as sampling rate, resolution of digitization and S/N ratio are analyzed. Result show accuracy, computing time and cost for different techniques.
A Multi-Agent Approach to Arabic Handwritten Text Segmentation  [PDF]
Ashraf Elnagar, Rahima Bentrcia
Journal of Intelligent Learning Systems and Applications (JILSA) , 2012, DOI: 10.4236/jilsa.2012.43021
Abstract: The segmentation of individual words into characters is a vital process in handwritten character recognition systems. In this paper, a novel approach is proposed to segment handwritten Arabic text (words). We consider the “Naskh” font style. The segmentation algorithm employs seven agents in order to detect regions where segmentation is illegal. Feature points (end points) are extracted from the remaining regions of the word-image. Initially, the middle of every two successive end points is considered as a candidate segmentation point based on a set of rules. The experimental results are very promising as we achieved a success rate of 86%.
Decrease of TSP, PM10, and Lead Concentration in a Lead Company in Alexandria City, Egypt  [PDF]
Ashraf A. Zahran
Journal of Environmental Protection (JEP) , 2013, DOI: 10.4236/jep.2013.41017

The study was carried out in a lead company inside Alexandria which exists in a residential area. Different sites have been selected inside the Department of Lead Improvement to measure TSP, PM10, and heavy lead during the melting process which takes place inside big alloying kettles and from the stack emissions. After that, the company made evaluation of the old factory and decision makers decided to make development for this factory through buying a complete unit for treatment with a special filter to make abatement for the level of emission especially for lead. The aim of this work is: 1) Put a plan for monitoring the level of different pollution after modification and to calculate the percentage of decrease (efficiency) of the new control unit through concentration of TSP, PM10, and lead through different processes; 2) Install a new filter to abate the different air pollutants such as TSP, PM10, and lead. Total Suspended Particulate (TSP) and Respiratory dust (PM10) measured by using Volume sampler and Air mitrix. Lead was measured by the digestion of the samples with a mixture of hydrochloric and nitric acids and using Atomic Absorption Spectropho- tometer. Results of measuring TSP, PM10, Lead in working environment, and lead inside stack before and after installation of the new filter showed percentage of decrease from 22% to 120%, 33% to 160%, 26% to 102%, and 51% to 56.5% respectively.


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