One of the solutions of the Helmholtz equation is the vortex beams. In the recent decades, production and applications of these types of beams have found serious attentions. Determination of the vortex beam topological charge and its sign are very important issues. Odd number of reflections of the vortex beam changes its vorticity. In this paper, we have used a q-plate to generate a vortex beam...

Turbidity currents in the ocean and lakes are driven by suspended sediment. The vertical profiles of velocity and excess density are shaped by interaction between the current and bed as well as between the current and the ambient water. This paper presents 48 series of experiments in which saline gravity currents flow through a laboratory sinuous flume. flume contains three successive bends wit...

background and objectives: evidence shows that transfer of hospital governance to board of trustees can positively influence hospital performance. iran has initiated implementing such a transformation and a number of hospitals have been involved in this reform. this study aimed to explore the effectiveness of such a reform by examining performance profile of a sample hospital across the interve...

background: physical wedges are still widely used as beam modifiers in external beam radiotherapy. however the presence of them in the beam trace may cause beam hardening which may not be considered in many treatment planning systems. the aim of this study is to investigate the beam hardening effect generated by physical wedges via different beam quality indexes as photon spectrum, half value l...

It is postulated that the outcomes in treating breast cancer with intraoperative radiotherapy (IORT) would be affected by the residual cancer cell distribution within the tumor bed. The three-dimensional (3D) radiation doses of IntrabeamTM (IB) IORT with a 4-cm spherical applicator at the energy of 50 and 40 kV were calculated. The modified linear quadratic model (MLQ) was used to estimate the ...

BACKGROUND To improve local control rate in patients with breast cancer receiving adjuvant radiotherapy after breast conservative surgery, additional boost dose to the tumor bed could be delivered simultaneously via the simultaneous integrated boost (SIB) modulated technique. However, the position of tumor bed kept changing during the treatment course as the treatment position was aligned to bo...

the ball and beam system is one of the most popular laboratory setups for control education. in this paper, we design a fuzzy pd cascade controller for a ball and beam system using asexual reproduction optimization (aro) technique. the ball & beam system consists of a servo motor, a grooved beam, and a rolling ball. this system utilizes a servo motor to control ball’s position on the beam. chan...

High cost of metal powders has increased the demand for recycling unmelted powder in electron beam bed fusion additive manufacturing process. However, characteristics are likely to change during manufacturing, recovery and reuse. It is important track evolution at different stages produce components with consistent properties. The present work evaluates changes Ti6Al4V properties by characteris...