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Books by hafiz hamza

Papers by hafiz hamza

World Journal of Integrated Traditional and Western Medicine, 2014

Radix bupleuri( chaihu) is a common herb for relieving liver qi stagnation and has drawn the atte... more Radix bupleuri( chaihu) is a common herb for relieving liver qi stagnation and has drawn the attention for anti- depression in the field of TCM. By retrieving the relevant literatures at home and abroad in recent years,the research status of clinical efficacy and modern pharmacology were analyzed and summed up in terms of radix bupleuris compounds. It was found that the classic formulas such as xiaoyao san,chaihu shugan san,xiaochanhu tang and chaihu longgu muli tang had clinical significant efficacy on depression,in which,radix bupleuri is acting as the conducting herb to liver meridian. The pharmacological experimental research suggested that classic radix bupleuri formulas and some self- prepared formulas have become the main formulas for the treatment of depression,in which the single radix bupleuri plays its remarkable action on anti- depression,as one of the major herbs for anti- depression. The active composition of radix bupleuri,saikosaponin is the main component for anti- ...

The exposure to magnetic fields and their effects plays a major issue in the human biological stu... more The exposure to magnetic fields and their effects plays a major issue in the human biological study, so the need for the magnetic fields evaluation inside the electrical power system installations becomes necessary. The electrical power substations are considered the main element in any electrical power system all over world. So, there is a necessity for the evaluation of the magnetic fields and their effects on the engineering workers exist inside these power substations. In this paper, two actual and different voltage level conventional electrical power substations (500/220 kV and 220/66 kV), in Egypt, are modeled and considered.

Introduction Emulsions are of considerable practical significance both in processing industry and... more Introduction Emulsions are of considerable practical significance both in processing industry and in the consumer sector. In the petroleum industry emulsions phenomena are particularly aware because it can lead to upstream and downstream production upset. A recent report stated that about 80% of exploited crude oil exists in an emulsion state, all over the world (Xia et al., 2004). Emulsions are distribution or dispersion of one liquid, in the form of droplets, in another substantially immiscible liquid (Schramm, 1992). The liquid which exists as discrete particles is known as the internal or dispersed phase, the other liquid is known as the dispersing medium or external or continuous phase. Emulsification process allows these two immiscible components to be compounded into a single macrophase mixture together with an emulsifying agent. There are two basic types of emulsion in the petroleum industry, the oil-in water (o/w) type and the water-in-oil (w/o) type. The most common type o...

Critical Reviews in Solid State and Materials Sciences, 2021

Abstract Additive manufacturing (AM) of metallic alloys offers a new avenue to print objects havi... more Abstract Additive manufacturing (AM) of metallic alloys offers a new avenue to print objects having complex geometries. This exclusive benefit of AM has made it an alternative route to conventional manufacturing. Importantly, additively manufactured (AMed) alloys often exhibit improved microstructures, which may provide better properties. The microstructure of an alloy can be tuned by controlling the processing parameters. This study includes an overview of the processing parameters that can influence the microstructural, mechanical, and corrosion properties of AMed alloys. Moreover, the effects of heat treatment on AMed alloys are also discussed. Among various processing parameters, it is observed that the laser power significantly influences the microstructure. The microstructures produced with high laser power are similar to heat-treated samples for 316L stainless steel (SS) and Ti6Al4V. Similarly, variation in scanning speed results in distinct morphology of grains in Ti6Al4V. Moreover, different AM processes, such as SLM and EBM, produce coarse and fine β grains, respectively, in Ti6Al4V. The fabrication of AlSi10Mg yields various sizes of melt pool due to different scanning strategies. Furthermore, mechanical properties such as microhardness is higher and the yield strength is lower for Ti6Al4V fabricated at lower laser power. The corrosion behavior of SLMed Ti6Al4V is different on the perpendicular and parallel planes to the build direction. Due to the increase in grain size after heat treatment, the corrosion resistance of AMed Ti6Al4V and AlSi10Mg is reduced. In contrast, heat treatment applied on 316L, Ti6Al4V, AlSi10Mg, and Inconel 718 is beneficial for mechanical properties. After the development of materials with optimized processing parameters, the research should be conducted on replacement of the wrought alloys with the AMed alloys. It is expected that new applications such as fuel cells and biomedical devices will utilize the AM technology to build parts in the recent future.

Materials Science and Engineering: C, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Materials and Manufacturing Processes, 2019

The accurate cutting of clad-composites through conventional practices is difficult due to the in... more The accurate cutting of clad-composites through conventional practices is difficult due to the intrinsic heterogeneity of the constituent layers. Thermal cutting (gas/plasma) is commonly employed for machining of such composites. But thermal cutting yields poor cut quality, deep heat-affected regions and needs subsequent finishing operations. Wire electric discharge machining (WEDM) is a valuable substitute but the issue of low cutting rate limits its use. Therefore, this research aims to address the low cutting rate issue to justify the feasibility of WEDM for cutting of stainless-steel clad-composite. In addition to considering the workpiece and process-associated factors, zinc-coated wire is used in WEDM of cladded-workpiece. Experimental results obtained under L18 designed experiments are comprehensively analyzed through various statistical and optical microscopic analyses. Empirical model and optimal parametric combination have also been achieved and validated via confirmatory experiments. An improvement of 50.5% in cutting rate is realized with coated wire at S/N-optimal settings as compared to cutting rate achieved at L18-optimal settings using uncoated brass wire in WEDM of clad-composite. This improvement in cutting rate is attributed to the zinc-coating that pronounces the discharge capability of wire owing to its higher electrical conductivity.

Journal of Management Control, 2013

The notion of organizational commitment has been intensively discussed in many fields of contempo... more The notion of organizational commitment has been intensively discussed in many fields of contemporary management research. Current literature in the field of leadership suggests that leadership styles of top management, i.e., CEOs and business unit heads, affect the level of commitment among middle-and lower-level managers. In a parallel vein, scholars in the field of management accounting and control argue that these effects are due to an organization's management control system. This study is aimed at closing the gap between both strands of literature and examines how leadership and management control systems interact in the process of creating organizational commitment. Building on structural equation modeling, the study extends existing knowledge by analyzing whether the relations between top management's leadership styles, i.e., initiating structure and consideration, and organizational commitment are mediated by the use of formal and informal management control elements. Based on a sample of 294 German firms, the results suggest that informal control elements, such as personnel and cultural controls, act as hinges through which top management is able to positively transmit leadership behaviors and affect the development of organizational commitment.

11th IEEE Mediterranean Electrotechnical Conference (IEEE Cat. No.02CH37379)

ABSTRACT The electric utility planning process begins with the electric load forecasting, because... more ABSTRACT The electric utility planning process begins with the electric load forecasting, because of the advanced need for new utility plants. These long lead times require the utility planning horizon to be at least ten years long. Since utility decisions involve an economic analysis ...

Energy Conversion and Management, 1996

A~traet-This paper describes switching operations and the accompanying overvoltages produced on c... more A~traet-This paper describes switching operations and the accompanying overvoltages produced on composite feeders when a circuit breaker closes at the peak of the applied voltage. Transformer and linecable feeders are considered. The means of reducing such overvoltages are also included, and the effect of system parameters and factors on the initial voltage applied and accompanying overvoltages are covered.

Electric Power Systems Research, 2005

Power frequency (50/60 Hz) magnetic field exposure still draws the attention of many researchers ... more Power frequency (50/60 Hz) magnetic field exposure still draws the attention of many researchers worldwide to investigate its harmful effects on living bodies. In light of this attention, as the population increases, the overlap between the power transmission lines and the settlement areas causes a problem (as in the case of exposure in random, residential, commercial and other areas, which lie very near or under the power transmission lines). In this paper, the power frequency magnetic fields, over a human body, at different positions, near extra high voltage (EHV) transmission lines are demonstrated, both analytically and practically. For the analytical part, the human body is approximately simulated as a parallelepiped. Two different positions for a human are selected near 500 and 220 kV power transmission lines. The magnetic field intensity along the vertical center line of the human is calculated. The effects of two different line configurations (for 220 and 500 kV power systems) and human positions, with respect to the transmission line, are considered. The paper also presents the actual practical magnetic field values measured near actual power transmission lines (220 and 500 kV) using a magnetic field measuring instrument. These transmission lines represent parts of the transmission network of the Egyptian united power system, near Cairo and El-Asher of Ramadan, under the actual loads. The results obtained, from the analytical studies and practical measurements, are compared with the international standards of the magnetic field exposures.

International Journal of Advanced Computer Science and Applications

A high number of people, affected with neurolocomotor disabilities or those paralyzed by injury c... more A high number of people, affected with neurolocomotor disabilities or those paralyzed by injury cannot use computers for basic tasks such as sending or receiving messages, browsing the internet, watch their favorite TV show or movies. Through a previous research study, it was concluded that eyes are an excellent candidate for ubiquitous computing since they move anyway during interaction with computing machinery. Using this underlying information from eye movements could allow bringing the use of computers back to such patients. For this purpose, we propose an imouse gesture control system which is completely operated by human eyes only. The purpose of this work is to design an open-source generic eye-gesture control system that can effectively track eye-movements and enable the user to perform actions mapped to specific eye movements/gestures by using computer webcam. It detects the pupil from the user's face and then tracks its movements. It needs to be accurate in real-time so that the user is able to use it like other every-day devices with comfort.