Development of a KDP crystal growth system based on TRM and characterization of the grown crystals

A solution growth system has been built based on temperature reduction method [1]. A few KDP crystals were grown by the system up to 160×40×38 mm dimensions. Spectrophotometer transmission spectra from (100) planes of the grown crystals show about 86 % transmission in the visible region. XRD analysis, laser damage threshold, and microhardness of the crystals were determined. The etching behavior of surface features of grown KDP single crystals was studied in different etchants

First-line therapy for post-traumatic stress disorder : a systematic review of cognitive behavioural therapy and psychodynamic approaches

Background: Despite evidence supporting cognitive behavioural therapy (CBT) based interventions as the most effective approach for treating posttraumatic stress disorder (PTSD) in randomised control trials, alternative treatment interventions are often used in clinical practice. Psychodynamic (PDT) based interventions are one example of such preferred approaches, this is despite comparatively limited available evidence supporting their effectiveness for treating PTSD. Aims: Existing research exploring effective therapeutic interventions for PTSD includes trauma-focused CBT involving exposure techniques. The present review sought to establish the treatment efficacy of CBT and PDT approaches, and considers the potential impact of selecting PDT-based techniques over CBT-based techniques for the treatment of PTSD.Results: The evidence reviewed provided examples supporting PDT-based therapy as an effective treatment for PTSD, but confirmed CBT as more effective in the treatment of this particular disorder. Comparable dropout rates were reported for both treatment approaches, suggesting that relative dropout rate should not be a pivotal factor in the selection of a PDT approach over CBT for treatment of PTSD.Conclusion/Implications: The need to routinely observe evidence-based recommendations for effective treatment of PTSD is highlighted and factors undermining practitioner engagement with CBT-based interventions for the treatment of PTSD are identified

Fatigue life of machined components

A correlation between machining process and fatigue strength of machined components clearly exists. However, a complete picture of the knowledge on this is not readily available for practical applications. This study addresses this issue by investigating the effects of machining methods on fatigue life of commonly used materials, such as titanium alloys, steel, aluminium alloys and nickel alloys from previous literature. Effects of turning, milling, grinding and different non-conventional machining processes on fatigue strength of above-mentioned materials have been investigated in detail with correlated information. It is found that the effect of materials is not significant except steel in which phase change causes volume expansion, resulting in compressive/tensile residual stresses based on the amounts of white layers. It is very complex to identify the influence of surface roughness on the fatigue strength of machined components in the presence of residual stresses. The polishing process improves the surface roughness, but removes the surface layers that contain compressive residual stresses to decrease the fatigue strength of polished specimens. The compressive and tensile residual stresses improve and reduce fatigue strength, respectively. Grinding process induces tensile residual stresses on the machined surfaces due to high temperature generation. On the other hand, milling and turning processes induce compressive residual stresses. High temperature non-conventional machining generates a network of micro-cracks on the surfaces in addition to tensile residual stresses to subsequently reduce fatigue strength of machined components. Embedded grits of abrasive water jet machining degrade the fatigue performance of components machined by this method

On the Introduction of an Agile, Temporary Workforce into a Tandem Queueing System

We consider a two-station tandem queueing system where customers arrive according to a Poisson process and must receive service at both stations before leaving the system. Neither queue is equipped with dedicated servers. Instead, we consider three scenarios for the fluctuations of workforce level. In the first, a decision-maker can increase and decrease the capacity as is deemed appropriate; the unrestricted case. In the other two cases, workers arrive randomly and can be rejected or allocated to either station. In one case the number of workers can then be reduced (the controlled capacity reduction case). In the other they leave randomly (the uncontrolled capacity reduction case). All servers are capable of working collaboratively on a single job and can work at either station as long as they remain in the system. We show in each scenario that all workers should be allocated to one queue or the other (never split between queues) and that they should serve exhaustively at one of the queues depending on the direction of an inequality. This extends previous studies on flexible systems to the case where the capacity varies over time. We then show in the unrestricted case that the optimal number of workers to have in the system is non-decreasing in the number of customers in either queue.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47647/1/11134_2005_Article_2441.pd

What is the value of orthodontic treatment?

Orthodontic treatment is as popular as ever. Orthodontists frequently have long lists of people wanting treatment and the cost to the NHS in England was £258m in 2010-2011 (approximately 10% of the NHS annual spend on dentistry). It is important that clinicians and healthcare commissioners constantly question the contribution of interventions towards improving the health of the population. In this article, the authors outline some of the evidence for and against the claims that people with a malocclusion are at a disadvantage compared with those without a malocclusion and that orthodontic treatment has significant health benefits. The authors would like to point out that this is not a comprehensive and systematic review of the entire scientific literature. Rather the evidence is presented in order to stimulate discussion and debate