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The maximum ground level air concentration from elevated point source over simple terrain is estimated using previous work by Essa et al. (2007). The eddy diffusivities in linear forms are used. The critical of the wind speed, plume height and downwind distance are estimated. The results of the maximum concentrations are applied using meteorological data of a plant stack located in, Inshas, Egypt.

The concentration of radon has been investigated in a university campus in Nigeria to determine the health risk of the workers in the community. Seventy- eight offices were statistically selected for measurement from all the Colleges. Measurements were performed using a passive radon dosimeters comprising (CR-39) solid state nuclear track detector, for a period of six months. The detectors were chemically etched with 6.25 M solution of NaOH at 70oC for 3 hours. The track were manually counted with microscope coupled with charged coupled digital (CCD) camera. Radon concentrations were statically determined. The mean radon concentration and the effective dose obtained in this work were 18.8 Bq m-3 and 0.02 mSv y-1 respectively. The mean value for excess lung cancer risk was estimated to be 0.08 (MPY)-1. When compared with published data and international references, the results obtained in the current study were found to be within the safe limits. Our study also revealed that radon concentrations tend to be higher on the ground floor and reduced with height due air dilution.

Chemical vapour deposition (CVD) is a widely used method for depositing thin films of a large variety of advanced materials. Applications of CVD range from the fabrication of microelectronic devices to the deposition of protective coatings but also optoelectronic films, decorative coatings.

The Fourier transform infrared (FTIR) and FT - Raman spectra of 2, 6-dichlorophenyl isocyanate have been recorded in the liquid state. The molecular geometry, vibrational frequencies, and atomic charges have been calculated by using density functional theory (DFT) calculation (B3LYP) with 6-311+G(d,p) and 6-311++G(d,p) basis sets. Simulated FTIR and FT - Raman spectra for 2, 6-dichlorophenyl isocyanate showed good agreement with the observed spectra. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. The molecular stability and bond strength were investigated by applying the natural bond orbital (NBO) analysis and electrostatic potential (ESP). The isotropic chemical shift computed by 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the 2, 6-dichlorophenyl isocyanate calculated using the gauge invariant atomic orbital (GIAO) method also shows good agreement with experimental observations.

Oil and grease removal process, through the use of fenton oxidation reaction on an oil polluted wastewater from a vegetable oil plant has been studied. The study was designed to assess the effectiveness of fenton oxidation reaction process in eliminating oil and grease contaminant in the wastewater. The raw wastewater was subjected to analysis through standard methods to determine BOD, Oil and grease, phenol, salinity and sodium batch oxidation process was adopted to remove the oil and grease in which four input parameters ; ph, Fe2+, temperature and hydrogen peroxide(H2O2) were considered. Four runs of experiment were performed where each parameter was varied while the other three remained constant. In each run, oil and grease removal was determined at ten minutes interval for 60 minutes through analysis. The results showed that the highest oil and grease removal efficiencies of 96.28% 98.74%, 99.02 and 93.03%were achieved at the optimum conditions of ph=3, fe2+=3.2 g/l, temp=450C and H2O2=4.5moles respectively and the oil and grease removal was progressive with time until at the point of inflection at 50 minutes where the removal appeared steady. Oil and grease removal efficiency was highly sensitive to the operating conditions. At excess values of the operating conditions, that is, at values beyond the optimum values, the rate of formation of the hydroxyl radical (OH•) became sluggish, impairing removal process. This also explained why the removal efficiency progressed to the plateau at the optimum condition values, and then declined as the values of the operating conditions increased.

The relationship among the turning point, the critical strip and the zeros of Riemann Zeta function is Investigated and established in this paper. A theorem to prove the link between the turning point and the real part of a quadratic function with complex roots is also presented, thereby showing that the real part of the roots will always be the critical point of the quadratic function, thus establishing Riemann’s hypothesis. is shown to be the analytic continuation formula of as presented by Riemann, amidst the various presentations of in his work. A proof of the nature of the zeros is found in this work.

The main goal of this study is finding optimal place of unified power flow controller (UPFC) and phase shifter (PST) in the power systems. In other words, the main concentration is on connecting FACTS and OPF tools opinion using PST and UPFC power injection model to find the best place of setting these elements in power networks. The objective function of maximizing static voltage stability edge (system loadability factor) is discussed in this paper. Simulation results are offered on IEEE 118_ bus standard network and they suggest that proposed algorithm includes the better resolution and there is a more little time than the other placement methods.

Meningococcal disease is a severe illness with high case fatality (5-10%) and frequent sequelae. Meningococcal meningitis is a major cause of morbidity and mortality in the meningitis belt. Meningococcal disease is a major public health challenge in countries of sub-Saharan Africa lying in the meningitis belt. Human infections caused by meningococcal (Neisseria meningitidis) remain a serious health problem, infecting 500,000 to 1.2 million people and killing between 50,000 and 135,000 per year worldwide. The causative agent, Neisseria meningitidis normally lives in a commensal relationship with humans, colonizing the nasopharynx, and is transmitted between healthy persons by close contact. The most common symptoms are a stiff neck, high fever, sensitivity to light, confusion, headaches and vomiting. Low meningitis thresholds improve timely detection of epidemics. The diagnosis of meningococcal meningitis is confirmed by cerebrospinal fluid pleocytosis, Gram stain, polymerase chain reaction, culture of cerebrospinal fluid. Meningococcal disease can be treated with a number of effective antibiotics. It is important that treatment be started as soon as possible. If meningococcal disease is suspected, antibiotics are given right away. Antibiotics effective for this purpose include rifampicin, ciprofloxacin, ceftriaxone or azithromycin. Currently available meningococcal vaccines include polysaccharide vaccines against serogroups A, C, W135 & Y and newer protein polysaccharide conjugate vaccines against serogroup C. This review covers key aspects of the pathogenesis and management of meningococcal disease, as well as the very recent developments in disease epidemiology, outbreaks, and the evolution of meningococcal immunizations.

Tensile stresses on concrete leading to the formation of cracks which further leads to the spalling of concrete. To overcome this shortcoming, due to its high tensile strength, ductility, ability to arrest propagation of cracks, improved bond strength, etc. This paper investigates the different strengths of Steel Fiber Reinforced Concrete (SFRC) using Fly ash as cement replacement. Silica fume and fly ash are the by-products and so has the uncontrolled engineering properties which sometimes don’t give the required results. The objective of this paper is to study the behavior of fly ash concrete with steel fibers under shear and torsion.

The Densu River is a typical river used for drinking water source, flowing through agricultural areas in Southern Ghana. Surface water and sediment samples at 45 sampling sites from the river and its tributaries were collected and analyzed for pesticides residues using GC with ECD/FID. Sampling was over a period of 24 months covering both the wet and dry seasons of 2007 and 2008.  Pesticide residues and metabolites detected in water and sediment samples were organochlorines (dieldrin, DDT, DDE, endosulfan sulphate, ?-endosulfan, ?- HCH, ?- HCH, aldrin, ? - chlordane ,endrin, endrin ketone, endrin aldehyde, methoxychlor and  heptachlor). In an average of 13.69% of sediment and 3.30% of water samples, at least one pesticide residue was detected per sample. A total of 8 different pesticides residues were detected in water samples with concentrations ranging between 0.1µgL^-1 and 48.6µgL^-1 whiles in sediment samples 14 different types were detected with concentrations ranging between 0.10µgL^-1 and 163.00µgL^-1. The maximum levels of residues were found in downstream section of the basin. Aldrin and dieldrin levels detected were above the recommended limit of 0.03 µgL^-1 with endosulfan, endrin and chlordane registering levels above their recommended limits of 20.0µgL^-1, 0.6µgL^-1 and 0.2 µgL^-1 respectively for drinking water. The ratio of DDE/DDT  in environmental matrix were quite high indicating there old input of DDT and significant degradation. The results implicitly revealed that improper land use in the basin has led to poor water quality.