Analytical and numerical water quality model for a sinusoidally varying pollutant discharge concentration

Analytical solution has been obtained for one-dimensional advection-diffusion equation which includes terms of decay and increasing sources by using Laplace transformation. Also numerical solution has been obtained by using explicit finite difference scheme. In this study the boundary condition applied at x = 0 describes a sinusoidal variation in pollutant concentration. The analytical solution obtained produces results that are exact for any location at any time. Impact of different parameters controlling the pollutant dispersion along the river at any time has been studied separately with figures help. This publication proved mathematically the fact that the high concentration of pollutant can be reduced by releasing fresh water discharges from Delta Barrage in the Nile River. For a real situation, our simple model can give decision support for planning restrictions to be imposed on cultivating and urban practices

Developmental changes in the concentration of elements present in breast milk during lactation period: A case study of some selected sites within Kano State, Nigeria

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Remediation of pollution in a river by releasing clean water using the solution of advection-diffusion equation in two dimensions

Analytical and numerical solutions are obtained for two-dimensional advection-diffusion equation, using Laplace transformation technique and explicit finite difference method for the pollutant concentration in a river or in shallow aquifer with time-dependent dispersion coefficients. We take two cases, first case: concentration of increasing nature (mixed type or third type) is considered at the origin and initially the domain is solute free. Second case: the river’s water is polluted initially (at time t = 0 ) while at the origin, at time t \u3e 0, the source of pollution is removed by releasing fresh water. We have proved mathematically the fact that the high concentration of pollutant can be reduced by releasing adequate discharges from barrage in a river. Both the dispersion coefficients, the velocity components and first order decay term are considered exponentially decreasing function of time. The different effects of the parameters controlling the pollutant dispersion along the river at any time are studied separately with the help of figures. The parameters that have a role in removing or reducing concentration of pollutant along the river have been studied in detail. When comparing the analytical solution with the numerical solution, we found a very good agreement between them. For a real situation, our simple model can provide decision support for planning restrictions to be imposed on farming and urban practices

دراسة اقتصادية تحليلية لكفاءة استخدام أنماط الري الحديثة: دراسة ميدانية بمزارع منطقة القصيم

The study aims to estimate the efficiency of water resources use for irrigation at Al-Qassim farms by estimating the productivity and technical efficiency, under different irrigation methods (sprinkler and drip irrigation) used for the main crops which are included in the sample of study, and estimating the demand functions for resources used in the production of main crops. The analysis based on the Data Envelopment Analysis (DEA), in addition to Total Factor Productivity (TFP) and parametric programming. The DEA is used with the constant and variant returns to scale (CRS and VRS) to estimate the technical efficiency and scale efficiency of the considered crops under different irrigation methods. The study sample (consists of 124 farms) was selected from the farms at Al-Qassim region, Data collected by the personal interview through a questionnaire which was prepared for this purpose, the study sample were representative the most important field and vegetable crops at the study area. The most important findings of the study can summarize as follows: (1) By estimation the technical (TE) and scale efficiency (SE) for the field and vegetable crops at the study sample according to the concept of VRS and CRS under different irrigation methods, the results show the following: * According to CRS hypothesis the average technical efficiency (TE) under mobile sprinkler irrigation method were lower for farms of wheat, barley, winter tomatoes, corn, summer tomatoes and alfalfa, while results refers to improvement of (TE) for these crops according to VRS hypothesis. * The average of scale efficiency (SE), which is (SE=TECRS / TEVRS) amounted to about 0.91, 0.89, 0.90, 0.91, 0.90, 0.90 under the mobile sprinkler irrigation system for the farms of wheat, barley, winter tomatoes, corn, summer tomatoes and summer cucumber. * According to CRS hypothesis the average technical efficiency (TE) under drip irrigation method were lower for farms of zucchini, winter tomatoes, winter cucumber, summer potatoes, summer tomatoes and summer cucumbers, while results refers to improvement of (TE) for these crops according to VRS hypothesis. * The average of scale efficiency (SE), was to about 0.86, 0.94, 0.83, 0.94, 0.94, 0.86 under the drip irrigation system for the farms of zucchini, winter tomatoes, winter cucumber, summer potatoes, summer tomatoes and summer cucumber. (2) The change in the index of total factor productivity (TFP Ch) of the quantity of production for winter tomatoes and summer tomatoes as a shift from the mobile sprinkler system to the drip system about 119%, 112% and refers to an opportunity to increase efficiency by 19%, 12%, while the change in the index of total factor productivity (TFP Ch) of the value of production for alfalfa as a shift from the fixed sprinkler system to the mobile sprinkler system about 103%. (3) By estimating the production and economic efficiencies based on stochastic frontier Analysis (SFA) using the ordinary least square (OLS) method and the maximum likelihood estimator (MLE) method. The (MLE) method was used under both the Truncated Distribution (TD) and Half-Normal Distribution (HND) techniques. The results indicated to the preference of MLE method in case of (HND) according to significance of γ to estimate the production efficiency of wheat, zucchini and alfalfa. While MLE method in case of (TD) according to significance of γ and the highest value of the LR was the best for crops winter and summer tomatoes, and winter and summer cucumbers. The OLS method was the fit to estimate the production efficiency of barley, corn and summer potatoes. (4) Using the parametric programming to identify the value of the marginal productivity (shadow prices) for each of the nitrogenous, phosphate fertilizers, agricultural employment and water resources. The results indicated that the shadow price of the unit (50 kg) for the resource of phosphate fertilizer up to about 69.1 SAR at the optimal use of the resource in the production of winter crops which follows the mobile sprinkler irrigation system, while up to about 131.3 SAR at the optimal use of the resource in the production of summer crops. For the resource of nitrogenous fertilizers used in the production of winter crops which follows the mobile sprinkler irrigation system, the shadow price of the unit (50 kg) up to about 295.4 SAR and up to about 68.7 SAR for the summer crops. For the labor resource used in the production of winter crops which follows the mobile sprinkler irrigation system, the shadow price of the unit (man / day) is approximately 52.3 SAR at the optimum utilization of the resource, while up to about 47.5 SAR to produce the summer crops

Screening for Tuberculosis and Its Histological Pattern in Patients with Enlarged Lymph Node

Settings. Tuberculosis is a major health problem in the Republic of Yemen. Tuberculous lymphadenitis is one of the most common forms of extrapulmonary tuberculosis. Therefore, this retrospective descriptive study was conducted in Yemen to investigate the morphological pattern of tuberculous lymphadenitis, as well as to assess the reliability measures of (ZN) Ziehl-Neelsen and fluorescent methods in identification of Mycobacterium tuberculosis. Methodology. One hundred lymph nodes tissue biopsies that were previously diagnosed by conventional histopathology as having tuberculous lymphadenitis were reinvestigated. Five micron in thickness sections were obtained from formalin-fixed paraffin wax processed tissues. The sections were stained using Haematoxylin and eosin (H & E), ZN, and fluorescent methods. Results. All of the 100 specimens were proved as having histopathological pattern of tuberculosis lymphadenitis. The most major histological features were giant cell (88%), caseation (84%), epithelioid cells (80%), granuloma and caseation (68%), lymphocytes (31%), and histiocytes (4%). After staining the specimens with ZN and fluorescent, of the 100 specimens only 3 (3%) and 9 (9%) specimens were found positive, by ZN and fluorescent methods, respectively. Conclusion. Conventional ZN and fluorescent methods have limitations in diagnosis of tuberculous lymphadenitis due to their lower sensitivity. Histopathology remains the most suitable method for the diagnosis of tuberculous lymphadenitis. In cases of suspected tuberculous lymphadenitis, it is advisable to confirm with more sensitive and specific method, such as polymerase chain reaction PCR or immunohistochemistry before reporting the negative results

Light and Electron Microscopical Studies on the Hyalocytes of Turkey (Meleagris Gallopavo)

The present study aimed to investigate the light and electron microscopical structure of the hyalocytes in turkey. This study was applied on a total number of 15 (10 males and 5 females) clinically healthy turkeys of Bronze black species, collected from a local farm in Assiut Governorate, Egypt. For sampling and fixation, 30 turkey's eyeballs were enucleated and subjected to study. The hyalocytes appeared as large cell with different shapes (rounded, oval or elliptical). They located within ambushes found along the outer surface of the retino-pecteneal membrane. In these cells, present numerous cytoplasmic vacuoles and large oval nucleus located near the internal part of the cell. There were many cytoplasmic processes that joined each other as a fine meshwork enclosing several vesicles or parts of foreign materials along the external portion of the cell. On the internal or deep surface of the cell present numerous filopodia, which extended to occupy the depressions found on the outer surface of the retino-pecteneal membrane. The presence of ingested foreign materials and the appearance of filopodia in a moving condition along the internal surface of the cell insure that hyalocytes are considered highly active phagocytic cells

Influence of using Straight and Twisted Elliptical Section Heater Tubes on Stirling Engine Performance

The heat transfer area of the heater tubes is a significant factor that deeply affects net output power and thermal efficiency in Stirling engines. It is greatly affected by the input heat transfer rate, heater tube geometries, and heat transfer removal rate. The alpha Stirling engine heater is our concern in this study. An ordinary circular and straight elliptical section heater tubes having different twisting ratios with a rectangular section-connecting duct are used to study the different heater tube configurations and twisting effect on the heat transfer characteristics and working fluid motion inside the engine. Three twisting ratios of two, three, and four with each section of the heater tube are used in this study. The 3D simulation model using the SST K-ω model using ANSYS FLUENT-16 is used for simulating airflow through the hot cylinder, heater tubes, regenerator, cooler, and cold cylinder of the Stirling engine, during a complete engine cycle. The results showed that increasing the twisting value increases the net output power and the thermal efficiency. The maximum net power output occurs at the elliptical section heater tube with a two-twist ratio with a value of 1249.26 W by an increase of 86.90 W with respect to the ordinary circular heater. In addition, the maximum thermal efficiency occurs at the elliptical section heater tube with a two-twist ratio with a value of 29.55% by an increase of 1.07% with respect to the ordinary circular heater

Medical Tourism Abroad : A new challenge to Oman’s health system - Al Dakhilya region experience

Objectives: This study aimed to understand why people seek medical advice abroad given the trouble and expense this entails. The types of medical problems for which treatment abroad was sought, preferred destinations and satisfaction with the treatment were explored. A secondary aim was to give feedback to stakeholders in the health care system on how to handle this issue and meet the needs of the community. Methods: 45 patients who had recently travelled abroad for treatment were asked to complete a questionnaire or were interviewed by telephone. Results: 40 questionnaires were received. 68% of the respondents were male. Orthopaedic diseases were the most common conditions leading patients to seek treatment abroad. Thailand was the most popular destination followed by India (50% and 30% respectively). 85% of respondents went abroad for treatment only, 10% for treatment and tourism and 2.5% were healthy, but travelled abroad for a checkup. Interestingly, 15% of the participants went abroad without first seeking medical care locally. Out of those initially treated in Oman, 38.2% had no specific diagnosis and 38.2% had received treatment, but it was not effective. 73% of respondents obtained information on treatment abroad from a friend. The Internet and medical tourism offices were the least used sources of information. 15% of the patients experienced complications after their treatment abroad. Conclusion: Various facts about medical treatment abroad need to be disseminated to the public. This will necessitate greater effort in public health promotion and education. 

Xanthogranulomatous Pyelonephritis: Analysis of 18 Cases

ObjectiveTo review and evaluate patients with a clinicopathological diagnosis of xanthogranulomatous pyelonephritis (XGP) with emphasis on the diagnostic methods and the effect of socioeconomic status on disease severity.MethodsData compiled from the previous history of the patients, clinical, laboratory, radioimaging findings, preoperative, operative, histopathological diagnosis and postoperative follow-up period were analysed. On the basis of presentation, XGP was classified as complicated and simple.ResultsThere were 18 cases of XGP. The clinical characteristics included: calculi or obstruction in the urinary tract, and damage to the kidney, complication of urinary tract infection, anaemia, increased erythrocyte sedimentation rate and liver dysfunction. All patients had diffuse XGP. Associated pathological findings such as psoas abscess, nephrocutaneous fistula, renocolonic fistula and paranephric abscess were found in 33.3% of cases. Eleven of 14 patients (78.6%) who were evaluated by computed tomography (CT) had the correct diagnosis made prior to nephrectomy. Urine culture was positive in 88.9% of patients and Proteus mirabilis was the most common organism.ConclusionOur experience with a small number of patients demonstrates that low socioeconomic status could be a risk factor in the development of complicated cases of XGP. CT is considered to be the best radiological test for correct preoperative diagnosis and evaluation of XGP. Nephrectomy and removal of all surrounding affected tissue proved to be curative for XGP