Porous silicon (PS) layers are prepared by anodization for
different etching current densities. The samples are then
characterized the nanocrystalline porous silicon layer by X-Ray
Diffraction (XRD), Atomic Force Microscopy (AFM), Fourier
Transform Infrared (FTIR). PS layers were formed on n-type Si
wafer. Anodized electrically with a 20, 30, 40, 50 and 60 mA/cm2
current density for fixed 10 min etching times. XRD confirms the
formation of porous silicon, the crystal size is reduced toward
nanometric scale of the face centered cubic structure, and peak
becomes a broader with increasing the current density. The AFM
investigation shows the sponge like structure of PS at the lower
current density porous begin to form on the crystalline silicon, when
the current density increases, pores with maximum diameter are
formed as observed all over the surface. FTIR spectroscopy shows a
high density of silicon bonds, it is very sensitive to the surrounding
ambient air, and it is possible to oxidation spontaneously.
In this research, a mathematical model of tumor treatment by radiotherapy is studied and a new modification for the model is proposed as well as introducing the check for the suggested modification. Also the stability of the modified model is analyzed in the last section.
In this study, we attempt to provide healthcare service to the pilgrims. This study describes how a multimedia courseware can be used in making the pilgrims aware of the common diseases that are present in Saudi Arabia during the pilgrimage. The multimedia courseware will also be used in providing some information about the symptoms of these diseases, and how each of them can be treated. The multimedia courseware contains a virtual representation of a hospital, some videos of actual cases of patients, and authentic learning activities intended to enhance health competencies during the pilgrimage. An examination of the courseware was conducted so as to study the manner in which the elements of the courseware are applied in real-time learn
... Show MoreThe present studier aims to study the kinetic of reaction at different experimental conditions depending on coliform bacteria concentration and hypochlorite ion. The effects that had been investigated were different of sodium hypochlorite doses, contact time, pH and temperature (20, 29, 37) o C. The water samples were taken from Al-Wathba water treatment plant in Risafa side of Tigris River in Baghdad. The biological tests included the most probable number (M.P.N) for indicating the concentration of coliform bacteria with different contact times and the total plate count (T.P.C) for indicating the amount of colonies for general bacteria. The iodimetry method (chemical test) was used for indicating the concentration of hypochlo
... Show MoreThis study assessed the advantage of using earthworms in combination with punch waste and nutrients in remediating drill cuttings contaminated with hydrocarbons. Analyses were performed on day 0, 7, 14, 21, and 28 of the experiment. Two hydrocarbon concentrations were used (20000 mg/kg and 40000 mg/kg) for three groups of earthworms number which were five, ten and twenty earthworms. After 28 days, the total petroleum hydrocarbon (TPH) concentration (20000 mg/kg) was reduced to 13200 mg/kg, 9800 mg/kg, and 6300 mg/kg in treatments with five, ten and twenty earthworms respectively. Also, TPH concentration (40000 mg/kg) was reduced to 22000 mg/kg, 10100 mg/kg, and 4200 mg/kg in treatments with the above number of earthworms respectively. The p
... Show MoreIn recent decades, global obesity has increased significantly, causing a major health problem with associated complications and major socioeconomic issues. The central nervous system (CNS), particularly the hypothalamus, regulates food intake through sensing the metabolic signals of peripheral organs and modulating feeding behaviors. The hypothalamus interacts with other brain regions such as the brain stem to perform these vital functions. The gut plays a crucial role in controlling food consumption and energy homeostasis. The gut releases orexigenic and anorexigenic hormones that interact directly with the CNS or indirectly through vagal afferent neurons. Gastrointestinal peptides (GIP) including cholecystokinin, peptide YY, Nesf
... Show MoreThe research starts from a fundamental problem about how top management team can realize the uncertainty. Strategic conversation has been introduced as a way for top management team to deal with uncertainties. Within the current research model, the strategic conversation was considered as an independent variable and uncertainty as dependent variable. The researcher used the survey method by distributed a questionnaire in the Administration and Economics College, University of Baghdad. Samples are 40 faculty participant of scientific committee members were distributed in seven scientific departments. The data were statistically analyzed by mean and the standard deviation. The hypotheses were tested through the use of correlation and regressi
... Show MoreAbstract. Shock chlorination is a well-known practice in swimming pools and domestic wells. One of the limitations for using this technique in drinking water purification facilities is the difficulty of quickly removing high chlorine concentrations in water distribution systems or production facilities. In order to use this method in the drinking water industry a shock de-chlorination method should be introduced for producing microorganism and biocide free water. De-chlorination using natural stagnant aeration (leaving the water to lose the chlorine naturally) is the safest known method if compared with chemical and charcoaling methods. Unfortunately, stagnant aeration is a slow process. Therefore, developing a process for accelerat
... Show MoreSingle long spiral tube column pressure swing adsorption (PSA) unit, 25 mm diameter, and 6 m length was constructed to study the separation of water from ethanol at azeotropic concentration of 95 wt%. The first three meters of the column length acted as a vaporizer and the remaining length acted as an adsorber filled by commercial 3A zeolite. The effect of pressure, temperature and feed flow rate on the product ethanol purity, process recovery and productivity were studied. The results showed that ethanol purity increased with temperature and pressure and decreased with feed flow rate. The purity decreased with increasing productivity. The purity range was 98.9 % to 99.6 %, the recovery range was 0.82 to 0.92 and the productivity range w
... Show MoreThis investigation was carried out to study the treatment and recycling of wastewater in the Battery industry for an effluent containing lead ion. The reuse of such effluent can only be made possible by appropriate treatment method such as electro coagulation.
The electrochemical process, which uses a cell comprised aluminum electrode as anode and stainless steel electrode as cathode was applied to simulated wastewater containing lead ion in concentration 30 – 120 mg/l, at different operational conditions such as current density 0.4-1.2 mA/cm2, pH 6 -10 , and time 10 - 180 minute.
The results showed that the best operating conditions for complete lead removal (100%) at maximum concentration 120 mg/l was found to be 1.2 mA/cm2 cur
The extraction of Basil oil from Iraqi Ocimum basillicum leaves using n-hexane and petroleum ether as organic solvents were studied and compared. The concentration of oil has been determined in a variety of extraction temperatures and agitation speed. The solvent to solid ratio effect has been studied in order to evaluate the concentration of Ocimum basillicum oil. The optimum experimental conditions for the oil extraction were established as follows: n-hexane as organic solvent, 60 °C extraction temperature, 300 rpm agitation speed and 40:1mL:g amount of solvent to solid ratio.