The present work considers the development of a computational model to simulate the dynamics of reed type valves of reciprocating compressors. Because the valve dynamics and the time dependent flow field through the valve are coupled, they are solved simultaneously. A one-degree of freedom model is adopted for the valve motion and the finite volume methodology is employed to obtain the flow fie...

This paper presents an adaptation of an existing dynamic trajectory method for unconstrained minimization to handle constrained optimization problems. This is done by the application of a dynamic penalty parameter procedure to allow for the constraints. The method is applied to structural optimization problems that involve the determination of minimum weight structures of trusses and frames, su...

The distributional k-dimensional Jacobian of a map u in the Sobolev space W 1,k−1 which takes values in the the sphere S can be viewed as the boundary of a rectifiable current of codimension k carried by (part of) the singularity of u which is topologically relevant. The main purpose of this paper is to investigate the range of the Jacobian operator; in particular, we show that any boundary M o...

AIM To determine the best method of estimating the optimum magnification needed by visually impaired patients. METHODS The magnification of low vision aids prescribed to 187 presbyopic visually impaired patients for reading newspapers or books was compared with logMAR distance and near acuity (at 25 cm) and magnification predicted by +4 D step near additions. RESULTS Distance letter (r = 0....

the doruneh fault is one of the longest and most prominent faults in iran. however, only two recorded historical earthquakes with magnitudes more than 7 might be related to this fault. for getting more information on this fault more investigation in different fields are required. fault displacement is one of the most important parameters needed to explore the fault activity. in this study, with...

the aim of the present study was to provide a clear picture of the prescribing pattern of corticosteroids in zanjan, iran. a retrospective and cross-sectional study was conducted to describe the pattern of corticosteroids prescription at beheshti pharmacy (zanjan, iran) over a period of six months between march 21 and september 22 of 2013. descriptive analyses were stratified by gender, age, typ...

A solution method is developed for a linear model of ice shelf flexural vibrations in response to ocean waves, which the thickness and seabed beneath vary over distance, shelf/sub–ice-shelf cavity are connected open ocean. The combines decomposition displacement profile at prescribed frequency motion into mode shapes free vibrations, finite-element water non-local operator connect An investigat...