442 research outputs found
Simple equation method for nonlinear partial differential equations and its applications
AbstractIn this article, we focus on the exact solution of the some nonlinear partial differential equations (NLPDEs) such as, Kodomtsev–Petviashvili (KP) equation, the (2+1)-dimensional breaking soliton equation and the modified generalized Vakhnenko equation by using the simple equation method. In the simple equation method the trial condition is the Bernoulli equation or the Riccati equation. It has been shown that the method provides a powerful mathematical tool for solving nonlinear wave equations in mathematical physics and engineering problems
Study of the Problem of Rising Groundwater levels in Aswan City Area
Aswan city, southern part of Egypt, is currently suffering from rising groundwater levels since 2009 due to partial discontinued pumping in some main well fields and growing urbanization in high relief areas; causing severe environmental problems hindering development activities. The present study aims to examine the changes in groundwater levels in the city using recorded data from 2012 to 2017. Numerical groundwater flow modeling is used to simulate the hydrogeological conditions of the region. Hence, the calibrated model is run to examine the solution of lowering groundwater. Inversing the groundwater rising process in the model is achieved by applying imposed abstraction rates, from eight well fields, equal to that before the rising levels problem. The adopted solution succeeded to nullify the rise in groundwater levels. However, further studies are recommended to evade negative geotechnical impacts so that the final design of an engineered solution can be set and physically implemented. Keywords: Groundwater management, Groundwater modeling, Groundwater de-watering, Nile Valley. DOI: 10.7176/CER/12-9-06 Publication date:September 30th 202
Effect of thermo-mechanical processing on structure and properties of dual-phase matrix ADI with different Si-contents
The improvement in the combination between strength and ductility of austempered ductile iron with dual matrix structure was investigated in two ductile irons having different silicon contents, namely 2.6 wt% and 4.0 wt%. The structure was produced in a thermo-mechanical simulator, equipped with a dilatometry system. The effect of silicon content on the transformation kinetics and mechanical properties was studied. For both ductile irons, the influence of introducing ferrite into the matrix on the structure development and mechanical properties was investigated and compared to those of completely ausferritic matrix. Increasing the Si-content widened the intercritical region and shifted it to higher temperature range. The former effect renders the intercritical annealing process more controllable. The introduction of the ferrite phase accelerated the ausferrite transformation kinetics and improved both the ductility and the formability index (ductility × ultimate strength), while both yield and ultimate strength declined
Numerical Solutions for the Time and Space Fractional Nonlinear Partial Differential Equations
We implement relatively analytical techniques, the homotopy perturbation method, and variational iteration method to find the approximate solutions for time and space fractional Benjamin-Bona Mahony equation. The fractional derivatives are described in the Caputo sense. These methods are used in applied mathematics to obtain the analytic approximate solutions for the nonlinear Bejamin-Bona Mahoney (BBM) partial fractional differential equation. We compare between the approximate solutions obtained by these methods. Also, we present the figures to compare between the approximate solutions. Also, we use the fractional complex transformation to convert nonlinear partial fractional differential equations to nonlinear ordinary differential equations. We use the improved -expansion function method to find exact solutions of nonlinear fractional BBM equation
Thermomechanical treatment of austempered ductile iron
The production of lightweight ferrous castings with increased strength properties became unavoidable facing the serious challenge of lighter aluminum and magnesium castings. The relatively new ferrous casting alloy ADI offers promising strength prospects, and the thermo-mechanical treatment of ductile iron may suggest a new route for production of thin-wall products. This work aims at studying the influence of thermomechanical treatment, either by ausforming just after quenching and before the onset of austempering reaction or by cold rolling after austempering. In the first part of this work, ausforming of ADI up to 25% reduction in height during a rolling operation was found to add a mechanical processing component compared to the conventional ADI heat treatment, thus increasing the rate of ausferrite formation and leading to a much finer and more homogeneous ausferrite product. The kinetics of ausferrite formation was studied using both metallographic as well as XRD-techniques. The effect of ausforming on the strength was quite dramatic (up to 70% and 50% increase in the yield and ultimate strength respectively). A mechanism involving both a refined microstructural scale and an elevated dislocation density was suggested. Nickel is added to ADI to increase hardenability of thick section castings, while ausforming to higher degrees of deformation is necessary to alleviate the deleterious effect of alloy segregation on ductility. In the second part of this work, the influence of cold rolling (CR) on the mechanical properties and structural characteristics of ADI was investigated. The variation in properties was related to the amount of retained austenite (Îłr) and its mechanically induced ransformation. In the course of tensile deformation of ADI, transformation induced plasticity (TRIP) takes place, indicated by the increase of the instantaneous value of strain-hardening exponent with tensile strain. The amount of retained austenite was found to decrease due to partial transformation of Îłr to martensite under the CR strain. Such strain-induced transformation resulted in higher amounts of mechanically generated martensite. The strength and hardness properties were therefore increased, while ductility and impact toughness decreased with increasing CR reduction
Multi-criteria governmental crop planning problem based on an integrated AHP-PROMETHEE approach
The study uses analytic hierarchy process (AHP) and preference ranking organisation method for enrichment evaluations (PROMETHEE) to deal with the crop planning problem as a multi-criteria decision-making problem, for governmental lands in Gaza Strip under two conditions: the normal economy condition and the resistant economy condition. These two conditions are studied from the governmental point of view. The study goal is to rank crops according to some considered criteria. Crops are divided into eight types that include vegetables, fruits, citrus, olives, palms, export crops, field crops and medical and aromatic crops. The developed AHP and PROMETHEE compare crops with respect to seven main criteria, namely; economical, financial, marketing, environmental, technical, political and social criteria. AHP is used to obtain criteria weights to be used as input for PROMETHEE to outrank alternatives.
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Pyloromyotomy for infantile hypertrophic pyloric stenosis using a modification of the Tan and Bianchi circumumbilical approach
Background/purpose Different approaches have been advocated for pyloromyotomy. Since the introduction of umbilical pyloromyotomy, a number of studies have shown that it is as safe as the traditional right upper quadrant approach with superior cosmetic results. The aim of this study was to assess the feasibility and the safety of pyloromyotomy for infantile hyprtrophic pyloric stenosis using a modification of the Tan–Bianchi approach.Patients and methods Over a period of 2 years, 20 infants with infantile hypertrophic pyloric stenosis have been clinically evaluated. The umbilical approach was modified so that a transverse muscle cutting incision rather than a longitudinal midline linea alba incision was performed.Results The total number of cases included in this study was 20 [16 male (80%) and four female (20%) patients]. Their ages ranged from 23 to 60 days (average 42.6 ±13.54 days), and their weights ranged from 2700 to 4000 g (mean 3605± 437.4 g). Pyloromyotomy was performed safely with negligible blood loss. Four cases of serosal tear occurred, with an incidence of 20%. None of our cases showed significant complications. The mean operating time was 52.5 ± 5.073 min. The postoperative hospital stay ranged from 24 to 72 h. The postoperative course was uneventful in all patients, and, on follow-up, the circumumbilical incision left an almost undetectable scar.Conclusion Pyloromyotomy for infantile hypertrophic pyloric stenosis using the modified Tan and Bianchi technique is feasible and safe, having an accepted operative time, early initiation of postoperative feeding, and short hospital stay. This modification combines the advantage of circumumbilical incision with its better cosmetic results and right transverse upper abdominal approach with its easy and feasible access to the pyloric mass.Keywords: operative intervention, pyloric stenosis, Tan–Bianchi approac
Development of Smart and Portable Controllable Syringe Pump System for Medical Applications
Due to their efficiency and adaptability, automated applications are consistently gaining popularity around the world. Robotics and their applications as used in a variety of commonplace industries, such as medical applications, require a high level of precision and accuracy. This can be achieved by utilizing automated applications. In this work, the development and design of a regulated injection pump is detailed. The developed prototype is a type of robot that can be utilized in hospitals and other medical facilities. The proposed design is used to pump specific liquid volumes as specified by the user. During liquid pumping, both the fluid’s volume and velocity can be manipulated. Implementation of the proposed system required the development of a complete mechanical system and a controller. The proposed system was implemented successfully, and its operation was deemed satisfactory. According to the results, the accuracy of the system was also satisfactory. Using a flow sensor, the reference value and the measured value acquired from the designed device were compared. Compared to similar devices, the proposed system demonstrated exceptional precision, with an average error rate of less than 1.5%. The proposed model has the advantages of using a commercially available injection syringe and being significantly less expensive than similar devices on the market
Development of Smart and Portable Controllable Syringe Pump System for Medical Applications
Due to their efficiency and adaptability, automated applications are consistently gaining popularity around the world. Robotics and their applications as used in a variety of commonplace industries, such as medical applications, require a high level of precision and accuracy. This can be achieved by utilizing automated applications. In this work, the development and design of a regulated injection pump is detailed. The developed prototype is a type of robot that can be utilized in hospitals and other medical facilities. The proposed design is used to pump specific liquid volumes as specified by the user. During liquid pumping, both the fluid’s volume and velocity can be manipulated. Implementation of the proposed system required the development of a complete mechanical system and a controller. The proposed system was implemented successfully, and its operation was deemed satisfactory. According to the results, the accuracy of the system was also satisfactory. Using a flow sensor, the reference value and the measured value acquired from the designed device were compared. Compared to similar devices, the proposed system demonstrated exceptional precision, with an average error rate of less than 1.5%. The proposed model has the advantages of using a commercially available injection syringe and being significantly less expensive than similar devices on the market
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