Continuous-wave operation of extremely low-threshold GaAs/AlGaAs broad-area injection lasers on (100)Si substrates at room temperature

Room-temperature continuous-wave operation of large-area (120 μm X 980 μm) GaAs/AlGaAs graded-refractive-index separate-confinement heterostructure lasers on (100) Si substrates has been obtained. Minimum threshold-current densities of 214 A/cm2 (1900-μm cavity length), maximum slope efficiencies of about 0.8 W/A (600-μm cavity length), and optical power in excess of 270 mW/facet (900-μm cavity length) have been observed under pulsed conditions

Adjust or invest : what is the best option to green a supply chain?

Greening a supply chain can be achieved by considering several options. However, companies lack of clear guidelines to assess and compare these options. In this paper, we propose to use multiobjective optimization to assess operational adjustment and technology investment options in terms of cost and carbon emissions. Our study is based on a multiobjective formulation of the economic order quantity model called the sustainable order quantity model. The results show that both options may be effective to lower the impacts of logistics operations. We also provide analytical conditions under which an option outperforms the other one for two classical decision rules, i.e. the carbon cap and the carbon tax cases. The results allow deriving some interesting and potentially impacting practical insight

Seroprevalence of human T-cell lymphotropic virus type 1 infection (HTLV1) in different patients in the north of Iran

Human T-cell lymphotropic virus type-1 (HTLV1) is a lymphotropic virus which can contribute to carcinogenesis in adult T-cell leukemia, myleopathy and other disorders. 20 million people are affected by this virus in the world. The aim of this study was to determine the incidence of human T-cell lymph tropic virus type 1 infection in patients referred to Emam’s hospital laboratory in Sari. A cross-sectional study was done in 2009 to 2010 based on the different patients that were referred to Emam`s hospital laboratory in Sari. Our samples were selected by simple random selection, after venous blood sample was centrifuged and reserved in -70°C. All the samples were tested by enzyme-linked immuno sorbent assay (ELISA). An ELISA positive result was checked by Western blot (WB) assays. Out of 1200 cases, 776 were female (65%) with ages between 1 and 76 years old. Most of the cases were Mazandaranian (99%); although only one person was recorded as HTLV1 positive (0.08%). He was a 41 years old man, living in Sari, with high school education. He was married (one wife) without any risk factor in past medical history, such as surgery, transfusion and abuse of injection, but he had HBV infection. Most of the females were housewives and most of the males were non-governmental employees; moreover, diabetes was more common among them. The results of the samples show that 122 women were pregnant, 92 cases had transfusion and 642 cases had different surgery. It was observed that the incidence of HTLV1 infection was very rare in the north of Iran (Sari); therefore, the routine HTLV1 screening was not recommended.Key words: Seroprevalence, human T-cell lymphotropic virus type-1 (HTLV1), patients, Iran

High speed modulation and CW operation of AlGaAs/GaAs lasers on Si

Microwave modulation and CW operation of AlGaAs lasers grown by MBE on Si substrates have been obtained for the first time. Ridge waveguide lasers(10µm×380µm) were modulated with a microwave signal up to 2.5GHz which is notable considering the structure used. Near and far field measurements indicated a single transverse mode and a narrow beam angle (4.8°). Finally, polarization measurements appear to show the solely TE nature of the emission

Paradox of Modern Pregnancy: A Phenomenological Study of Women's Lived Experiences from Assisted Pregnancy

The purpose of our study was describing the meaning of pregnancy through Assisted Reproductive Technologies (ARTs). A qualitative design with hermeneutic phenomenology approach was selected to carry out the research. Semistructured in-depth interviews were conducted with 12 women who experienced assisted pregnancy. Three themes emerged from women's experience including finding peace in life, paradoxical feelings, and struggling to realize a dream. We concluded that pregnancy is the beginning of a new and hard struggle for women with fertility problems. The findings of our study resulted in helpful implications for the health care professionals managing assisted pregnancies. Copyright © 2015 Fahimeh Ranjbar et al

Effect of enhanced external counterpulsation and cardiac rehabilitation on quality of life, plasma nitric oxide, endothelin 1 and high sensitive CRP in patients with coronary artery disease: A pilot study

Objective To investigate the effect of enhanced external counterpulsation (EECP) on plasma nitric oxide (NO), Endothelin 1 (ET1), high sensitive C-reactive protein (HSCRP) and quality of life (QoL) in patients with coronary artery disease (CAD).Methods We conducted a pilot randomized clinical trial in order to evaluate plasma NO, ET1, HSCRP and QoL before and after twenty sessions of EECP (group A) and cardiac rehabilitation (CR, group B) in 42 patients with CAD (21 in each group).Results Forty-two patients (33 male and 9 female) were included in the study. The mean age was 58.2±10 years. The mean HSCRP was 1.52±0.7 in the EECP group and it was reduced to 1.27±0.4 after intervention. The reduction in HSCRP was not statistically significant in EECP and CR groups with p=0.33 and p=0.27, respectively. There was not significant improvement of NO, ET1, and QoL in the EECP and CR groups shortly after therapy (p>0.05).Conclusion Although the short-term EECP treatment in CAD patients improved HSCRP, NO, ET1, and QoL compared with the baseline those improvements are not statistically significant. Further studies are necessary with large study groups and more sessions. © 2015 by Korean Academy of Rehabilitation Medicine

Almost-Tight Distributed Minimum Cut Algorithms

We study the problem of computing the minimum cut in a weighted distributed message-passing networks (the CONGEST model). Let $\lambda$ be the minimum cut, $n$ be the number of nodes in the network, and $D$ be the network diameter. Our algorithm can compute $\lambda$ exactly in $O((\sqrt{n} \log^{*} n+D)\lambda^4 \log^2 n)$ time. To the best of our knowledge, this is the first paper that explicitly studies computing the exact minimum cut in the distributed setting. Previously, non-trivial sublinear time algorithms for this problem are known only for unweighted graphs when $\lambda\leq 3$ due to Pritchard and Thurimella's $O(D)$-time and $O(D+n^{1/2}\log^* n)$-time algorithms for computing $2$-edge-connected and $3$-edge-connected components. By using the edge sampling technique of Karger's, we can convert this algorithm into a $(1+\epsilon)$-approximation $O((\sqrt{n}\log^{*} n+D)\epsilon^{-5}\log^3 n)$-time algorithm for any $\epsilon>0$. This improves over the previous $(2+\epsilon)$-approximation $O((\sqrt{n}\log^{*} n+D)\epsilon^{-5}\log^2 n\log\log n)$-time algorithm and $O(\epsilon^{-1})$-approximation $O(D+n^{\frac{1}{2}+\epsilon} \mathrm{poly}\log n)$-time algorithm of Ghaffari and Kuhn. Due to the lower bound of $\Omega(D+n^{1/2}/\log n)$ by Das Sarma et al. which holds for any approximation algorithm, this running time is tight up to a $\mathrm{poly}\log n$ factor. To get the stated running time, we developed an approximation algorithm which combines the ideas of Thorup's algorithm and Matula's contraction algorithm. It saves an $\epsilon^{-9}\log^{7} n$ factor as compared to applying Thorup's tree packing theorem directly. Then, we combine Kutten and Peleg's tree partitioning algorithm and Karger's dynamic programming to achieve an efficient distributed algorithm that finds the minimum cut when we are given a spanning tree that crosses the minimum cut exactly once

Role of the local stress systems on microstructural inhomogeneity during semisolid injection

High pressure metal die casting is an extremely dynamic process with widely ranging cooling rates and intensifying pressures, resulting in a wide range of solid fractions and deformation rates simultaneously existing in the same casting. These process parameters and their complex interplay dictate the formation of microstructural solidification defects. In this study, fast synchrotron X-ray imaging experiments simulating high pressure die casting of aluminium alloys were conducted to investigate the effect of solid fraction, loading conditions and semisolid flow on local microstructural inhomogeneity. While most of the existing literature in this field reports speeds up to 10 µm/s for in situ deformation, the present work captures much faster filling and solidification, at speeds closer to 100 µm/s and at different solid fractions. Semisolid deformation of low solid fractions reveals two typical microstructural features: (i) coarser grains in the middle and finer ones near the walls, and (ii) remelting near the solid-liquid interface due to Cu enrichment in the liquid by the flow. Ex situ scans and digital image correlation analysis of the higher solid fraction samples reveal a porosity formation mechanism based on the local state of stresses, microstructure and feeding. Four different characteristics were identified: (i) plug flow, (ii) dead zone (densified mush), (iii) shear and (iv) bulk zones. These insights will be used to develop zone-specific strategies for the numerical modelling of defect formation during die casting