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Search Results: 1 - 10 of 402195 matches for " Elham M. Abdalla "
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The Use of Bleaching Creams among Central Sudan Students, 2010  [PDF]
Abubakr K. Yousif, Aimun AE. Ahmed, Abdalla E. Idris, M. O. Elmustafa, Elham H. S. Ahmed
Pharmacology & Pharmacy (PP) , 2014, DOI: 10.4236/pp.2014.55063

The aim of this study was to examine the use of bleaching creams containing hydroquinone, corticosteroids and mercury for skin lightening among higher secondary school students in central Sudan. A cross-sectional epidemiological study was conducted at 19 different girls’ schools. A total of 1187 young students aged 16 - 19 years old were randomly selected and approached, using a well-structured questionnaire. The main outcome measure was a number of epidemiological factors per abusers. Results revealed that, 55.4% of the respondents misused this product, whilst 51.6% of girls used cosmetics to lighten their skin for 1 - 3 years with skin irritations prevalence of 3.3%, and the face was reported as main application site (35.4%). In conclusion, the lack of health awareness and ignorance was the main causative factor, whilst education, competent authorities awareness and prescriptions restrictions were highly recommended.

Evaluation of the Pozzolanic Activity of Sewage Sludge Ash
M. A. Tantawy,A. M. El-Roudi,Elham M. Abdalla,M. A. Abdelzaher
ISRN Chemical Engineering , 2012, DOI: 10.5402/2012/487037
Fire Resistance of Sewage Sludge Ash Blended Cement Pastes
M. A. Tantawy,A. M. El-Roudi,Elham M. Abdalla,M. A. Abdelzaher
Journal of Engineering , 2013, DOI: 10.1155/2013/361582
Abstract: The aim of the present study is to investigate the hydration characteristics and the fire resistance of sewage sludge ash blended cement pastes by the determination of compressive strength, bulk density, and total porosity in addition to XRD and SEM techniques. Sewage sludge ash modifies the hydration of cement because of its pozzolanic reaction with portlandite favoring the formation of crosslinked fibrous calcium silicate of low Ca/Si ratio. Hence, it was concluded that thermal damage of cement pastes after the exposure to high treatment temperatures (i.e., crack formation and loss of mechanical properties) was effectively reduced with sewage sludge as content up to 20?wt% because of that the presence of crosslinked fibrous calcium silicate strengthens the cement matrix. 1. Introduction Sewage water is the collection of wastewater effluents from domestic, hospital, commercial, and industrial establishments. The objective of the sewage treatment is to produce treated sewage water and sewage sludge suitable for safe discharge into the environment or reuse [1]. International environmental protection agencies recommended that incineration is an attractive disposal method of sewage sludge [2]. Sewage sludge ash has been used as an additive in the production of construction materials [3], mortars [4], and concrete [5]. The exposure of concrete to high temperatures as in an accidental fire of buildings leads to an undesirable structural quality deterioration [6]. Previous studies illustrate that hardened cement paste plays a key role in high temperatures deterioration process. The main damage mechanisms that discuss the deterioration of concrete at elevated temperatures are thermal mismatch, decomposition of hydrates, coarsening of pore structure, and pore pressure effects [7]. Siliceous aggregates expand around 575°C as a result of the α-β quartz inversion, whereas cement paste shrinks above 200°C [8]. This thermal mismatch (i.e., expansion of siliceous aggregate and shrinkage of cement paste matrix) causes a considerable tension at the aggregate-matrix interface leading eventually to interface fracture and cracking [9]. The decomposition of hydrates occurs during the thermal damage of cementitious materials including the decomposition of ettringite, C-S-H, and carboaluminate hydrates at 180–450°C and portlandite at 425–580°C [10]. The decomposition of portlandite damages the C-S-H. The decomposition of hydrates decreases stiffness and strength of cementitious materials. Volume reduction of the hydrated phases because of the loss of bound water leads to air
Evaluation of the Pozzolanic Activity of Sewage Sludge Ash
M. A. Tantawy,A. M. El-Roudi,Elham M. Abdalla,M. A. Abdelzaher
ISRN Chemical Engineering , 2012, DOI: 10.5402/2012/487037
Abstract: Raw sewage sludge was characterized by XRD, FTIR, SEM, and TGA techniques and incinerated in temperature range 650–950°C for 2?h. The effect of incineration temperature on the microstructure and pozzolanic activity of the resultant ash was investigated by techniques mentioned above as well as Chapelle test. It was concluded that incineration of sewage sludge affects the microstructure and pozzolanic activity of the resultant ash. During incineration at temperatures lower than 800°C, amorphous silica captures fixed carbon resulting from incomplete combustion conditions whereas at higher temperatures crystallization of amorphous silica was enhanced. Hydration products formed from hydrothermal treatment of silica fume with lime is amorphous whereas that of sewage sludge ash is fibrous. Hence, incineration of sewage sludge ash must be optimized at 800°C to preserve the pozzolanic activity of the resultant ash. 1. Introduction Sewage is the collection of wastewater effluents from domestic, hospital, commercial, industrial establishments, and rain water. The objective of sewage treatment is to produce treated sewage water and sewage sludge suitable for safe discharge into the environment or reuse [1]. The most common treatment options for sewage sludge include anaerobic digestion, aerobic digestion, and composting. Choice of the treatment method depends on the amount of sludge and other site-specific conditions [2]. Sewage sludge tends to accumulate heavy metals existing in the wastewater. The composition of sewage sludge and its content of heavy metals vary widely depending on the sludge origins and treatment options [3]. In past decades, sewage sludge was primarily disposed to landfills and seawaters [4]. Space limitations on existing landfills and increasing environmental concerns such as groundwater pollution from landfill leachate, odor emission and soil contamination have prompted the investigation of alternative disposal routes [5]. Sewage sludge has been used in agriculture as fertilizer and soil amendment [6]. However heavy metals such as Zn, Cu, Ni, Cd, Pb, Hg, and Cr are principal elements restricting the use of sludge for agricultural purposes [3]. The solidification/stabilization of sewage sludge in cementitious matrix has been evaluated [7]. Sewage sludge adversely affects durability of concrete, mainly due to the organic material which retards setting and heavy metals which interfere with the hardening reactions [8]. Hence, sewage sludge addition in concrete was limited to 10?wt.% and the solidified concrete was recommended for use in certain
Exact Solution and Conservation Laws for Fifth-Order Korteweg-de Vries Equation  [PDF]
Elham M. Al-Ali
Journal of Applied Mathematics and Physics (JAMP) , 2013, DOI: 10.4236/jamp.2013.15007

With the aid of Mathematica, new exact travelling wave solutions for fifth-order KdV equation are obtained by using the solitary wave ansatz method and the Wu elimination method. The derivation of conservation laws for a fifth-order KdV equation is considered.

A Centralized Energy Coordinator Reliant on BESS and DER-PV Operation  [PDF]
Joseph M. Lavalliere, Elham B. Makram
Journal of Power and Energy Engineering (JPEE) , 2016, DOI: 10.4236/jpee.2016.48005
Abstract: Many existing battery energy storage system (BESS) control schemes focus on mitigating negative impacts resulting from the operation of distributed energy resources-photovoltaic facilities (DER-PV). These include out-of-firm conditions from reverse power flow or extreme variability in the service voltage. Existing control strategies fail to consider how BESS control schemes need to operate in a consecutive day-to-day basis in order for them to be implemented in the field. In this paper, a novel energy management algorithm capable of dispatching a BESS unit upstream of a multi-megawatt DER-PV is introduced. This algorithm referenced as the Master Energy Coordinator (MEC), accepts forecasted DER-PV generation and individual feeder load to create daily charge and discharge rate schedules. Logic is integrated to the cyclic discharging event to sync with the forecasted peak load, even when it will occur during the morning of the next day. To verify the MEC operation, Quasi-Static Time Series (QSTS) simulations are conducted on a 12.47 kV distribution feeder model utilizing historical head-of-feeder and DER-PV analog DSCADA measurements.
Aquifer Characterization and Groundwater Potential Using Integrated Geoelectric Sounding and Geoinformatics in West Maghagha Area, Minia Governorate, Egypt  [PDF]
Abdulaziz M. Abdulaziz, Abdalla M. Faid
Open Journal of Geology (OJG) , 2017, DOI: 10.4236/ojg.2017.711109
Abstract: The study area is located in the western extension of the Nile Valley near the boundary with the Western Desert, where the groundwater represents the potential water resource for future land development for both industrial purposes and agricultural reclamation. Historically, geoelectric methods proved prospective and practical in exploring for groundwater resources. In this study, 17 Vertical Electric Sounding (VES) were acquired and processed to reveal the subsurface distribution of the water bearing layers and identify the groundwater potential in West Maghagha area. After routine data analysis and calibration, the preliminary results are interpreted in light of the available geological data and indicated the presence of at least four geoelectric layers with model resistivity values up to 2000 Ωm. The potential aquifer was encountered down to ~120 m depth with average thickness of 100 m and is made of argillaceous fractured carbonates. Despite the overall poor quality of this aquifer, the integrated geoelectric and hydrogeologic information indicated a possible potential occurrence of potable groundwater at the southern and northeastern parts of the study area. To improve understanding of the groundwater systems in the study area, detailed aquifer characterization is discussed through integration of the available geologic data, maps, and the geoelectric sections constructed from the VES.
Physical Factors Affecting the Interior Radon-Concentrations  [PDF]
Soliman M. S. Abdalla, Saddig D. Jastaniah
Open Journal of Biophysics (OJBIPHY) , 2013, DOI: 10.4236/ojbiphy.2013.31004

Researchers have realized that radon-contaminated air inside buildings is a principal way of human exposure to certain healthy-risks. A model is developed to estimate radon concentrations which consider various parameters: in indoor air radon (radon-222) concentration, air permeability of ground, air pressure difference between outdoor and indoor at ground level, ventilation of building ground and number of air changes per hour due to ventilation. The radon-222 transport into building might dominated by diffusion, pressure driven flow or/and a mixture of both depending on the actual values of the various parameters. So, in several and regular periods of time: January, April, July and October, radon-222 concentrations have been measured in ten rooms of five elementary schools and in five rooms of one high school at Qena city (Upper Egypt). This has been carried out using alpha scintillation counters. We have noticed that in three rooms the value has exceeded 200 Bqm -3 at the basement and only one room at the first floor, and all values have changed with respect to time and localization: They have decreased from July to January and from basement to first floor. For example, radon-222 concentrations obtained by exposing track detectors varied in the range from 20 Bqm-3 up to 100 Bqm-3. The experimental results of the present work have been well fitted with the presented model (calculations) which supports the validity of the presented model. So, to decrease the level of indoor air radon-222 concentrations and to reduce its harmful effects it is recommended to follow the suggestions in the present study and to limit as possible the use of ceramic in the building construction, increase the hours of ventilation and to restrict the use of underground floors in buildings, the underground Metro and garage parking should be carefully (and even mandatory) ventilated.

Effects of Haemorrhage on Thermoregulation, Heart Rate and Blood Constituents in Goats (Capra hircus)
Selma E. Abdalla,Abdalla M. Abdelatif
Pakistan Journal of Biological Sciences , 2008,
Abstract: The effects of two levels of bleeding (15 and 30%) on physiological responses were evaluated in adult goats. The magnitude of haemorrhage was expressed as percentage of initial total blood volume after plasma volume determination by dye dilution. The groups subjected to haemorrhage had higher rectal temperature, respiration rate and heart rate compared to the control; the responses were more marked with the higher level of bleeding. The treated groups had lower Packed Cell Volume (PCV), haemoglobin concentration (Hb) and Total Leucocyte Count (TLC) compared to the control; they were significantly lower with high level of bleeding compared to the control. The ratio of lymphocytes decreased, whereas the neutrophil ratio increased in treated groups compared to the control. The treated groups had lower serum total protein and albumin concentrations compared to the control. The plasma glucose level was higher in treated groups compared to the control and it increased with the increase of bleeding level. The treated groups had lower serum Na, Ca and Mg concentrations compared to the control. The levels of these minerals decreased with increase of bleeding level. The 15% bleeding group returned to normal values within 2 weeks, whereas the 30% bleeding group recovered within 5 weeks.
Exact S matrices and extended supersymmetry
E. Abdalla,M. C. B. Abdalla
Physics , 1993,
Abstract: In this revised version we correct some mistakes, realizing the supersymmetry algebra on the exact S matrix, taking into account several phase factros. We study the constraint imposed by supersymmetry on the exact $S$-matrix of $\Complex P^{n-1}$ model, and compute a non-trivial phase factor in the relation between the $S$-matrix and one of the supersymmetry generators. We discuss several features connected with the physical interpretation of the result. The supersymmetry current is studied in such context as well, and we find some operators appearing in the conservation equation of the supersymmetry current that might be connected with such phase factors. The relation with the literature on the subject is also discussed. hep-th/yymmnnn
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