A review of photovoltaic module technologies for increased performance in tropical climate

The global adoption and use of photovoltaic modules (PVMs) as the main source of energy is the key to realising the UN Millennium Development Goals on Green Energy. The technology – projected to contribute about 20% of world energy supply by 2050, over 60% by 2100 and leading to 50% reduction in global CO2 emissions – is threatened by its poor performance in tropical climate. Such performance discourages its regional acceptance. The magnitude of crucial module performance influencing factors (cell temperature, wind speed and relative humidity) reach critical values of 90 °C, 0.2 m/s and 85%, respectively in tropical climates which negatively impact module performance indices which include power output (PO), power conversion efficiency (PCE) and energy payback time (EPBT). This investigation reviews PVM technologies which include cell, contact and interconnection technologies. It identifies critical technology route(s) with potential to increase operational reliability of PVMs in the tropics when adopted. The cell performance is measured by PO, PCE and EPBT while contacts and interconnections performance is measured by the degree of recombination, shading losses and also the rate of thermo-mechanical degradation. It is found that the mono-crystalline cell has the best PCE of 25% while the Cadmium Telluride (CdTe) cell has the lowest EPBT of 8-months. Results show that the poly-crystalline cell has the largest market share amounting to 54%. The CdTe cell exhibits 0% drop in PCE at high-temperatures and low irradiance operations – demonstrating least affected PO by the conditions. Further results establish that back contacts and back-to-back interconnection technologies produce the least recombination losses and demonstrate absence of shading in addition to possessing longest interconnection fatigue life. Based on these findings, the authors propose a PVM comprising CdTe cell, back contacts and back-to-back interconnection technologies as the technology with latent capacity to produce improved performance in tropical climates

Competitiveness of Turkish hidden champions

Understanding the competitive power of small and medium sized firms in emerging economies is a challenging task. This paper aims to analyze internationally successful small and medium sized firms that are so called hidden champions of emerging economies in the same way as they appear in advanced countries such as Germany and Austria. The analysis will shed some light to what makes these hidden champions so competitive in international markets. Knowing that developing country firms struggle to overcome the country-of-origin effects arising from the consumer perceptions on the country products/services, observing the successful practices might help to understand their strategies in overcoming these effects. The assessment of company practices in terms of competition is carried out by using a comprehensive model where the assessment of firm competitiveness is carried out through the outcome/performance of competition (i.e. output), assets/factors (i.e. input) and processes that turn the assets/factors into actual performance. The paper conducts a case study by concentrating in one emerging economy: Turkey. The in-depth analysis of 10 companies by using the firm competitiveness assessment model helps to identify some innovative ways of overcoming the country-of-origin effects. The paper ends with some managerial and policy implications

A congenital soft tissue ewing sarcoma in a newborn patient

PubMedID: 29168368Congenital Ewing sarcoma is extremely rare. Here we present a newborn baby born with a mass on the left shoulder. Immunohistochemical staining showed congenital Ewing sarcoma. Chemotherapy and then surgical operation were planned, however the patient died before initiation of chemotherapy on the 30th day of life. © 2017, Turkish Journal of Pediatrics. All rights reserved

Effects of two doses of anti-T lymphocyte globulin-Fresenius given after full-match sibling stem cell transplantation in acute myeloblastic leukemia patients who underwent myeloablative fludarabine/busulfan conditioning

Objective/background: Anti-T lymphocyte globulin Fresenius (rATG-F; ATG-Fresenius) and antithymocyte globulin (thymoglobulin), which are included in transplant protocols, are used to reduce the risk of chronic graft-versus-host disease (cGVHD) or suppress allograft rejection. Available clinical studies have been conducted in heterogenous patient populations and with different administration protocols including stem cell sources. Additionally, the pharmacokinetics of ATG is variable, and the clinically effective dose of rATG-F, in particular, is not exactly known. The aim of the study was to investigate the clinical outcomes of acute myeloid leukemia (AML) patients who underwent hemopoietic peripheral stem cell transplantation from full-matched sibling donors and given two different doses of r-ATG-F. Methods: This was a single-center, retrospective chart review conducted between July 2005 and July 2016. Sixty-nine consecutive AML patients who underwent transplant with fludarabine- and busulfan-based conditioning were included in the study. Patients in Group 1 received 15 mg/kg body weight rATG-F to 2013 (n = 46), and Group 2 received 30 mg/kg of rATG-F dose begining in 2013 to reduce to cGVHD (n = 23). Cyclosporine and methotrexate were used to treat acute GVHD (aGVHD) prophylaxis. Outcome parameters were compared between the groups. Results: Although the recommended dose r-ATG-F had led to a decrease in the cumulative incidence of cGVHD (27 [58.7%] vs. 8 [34.8%]; p =.03), it also increased the infection rate at 1 year (3 [6.5%] vs. 4 [17.4%]; p =.02). The two groups were similar in terms of engraftment time, aGVHD, relapse, nonrelapse mortality, and rATG-F-related toxicity. A Cox regression model revealed that aGVHD III–IV was associated with increased nonrelapse mortality at 1 year (hazard ratio = 18.2; 95% confidence interval, 1.667–199.255; p = <.02). No patients developed rATG-F-related severe adverse events (Common Terminology Criteria grade 4 or 5). Conclusion: Dose difference of rATG-F did not influence survival parameters; however, increasing the dose to 30 mg/kg seems to be effective for reducing cGVHD with an increase in infection rate requiring close monitoring of infections in AML patients who received myeloablative fludarabine/busulfan conditioning. © 2018 King Faisal Specialist Hospital & Research Centr

Prevalence of Rheumatoid Arthritis and Spondyloarthritis in Turkey: A Nationwide Study.

OBJECTIVES: This study aims to estimate the prevalence of rheumatoid arthritis (RA) and spondyloarthritis (SpA) in Turkey using the same telephone questionnaire developed for screening RA and SpA in France and used in Serbia and Lithuania. MATERIAL AND METHODS: The study was performed in two steps. In step I, the French questionnaire was translated into Turkish and validated through a group of 200 patients (80 males, 120 females; mean age 44.0±13.1 years; range 19 to 75 years) followed up at the rheumatology departments of University Hospitals in Antalya and Ankara. In step II, the validated Turkish questionnaire was administered face-to-face to randomly selected 4,012 subjects (1,670 males, 2,342 females; mean age 41.5±16.8 years; range 16 to 97 years) by trained general practitioners across the country, in 25 prov- inces for case detection. The subjects who were suspected of having RA or SpA in accordance with the questionnaire were invited to the nearest university hospital for rheumatologic examination in order to confirm the diagnosis. RESULTS: In step II, a total of 25 subjects (2 males, 23 females) were diagnosed as RA. The standardized RA prevalence for the general population of Turkey was calculated as 0.56% (95% confidence interval [CI]; 0.33-0.79), 0.10% (95% CI; -0.05-0.25) for males and 0.89% (95% CI; 0.51-1.27) for females. A total of 18 subjects (3 males, 15 females) were diagnosed as SpA. The standardized SpA prevalence for the general population of Turkey was 0.46% (95% CI; 0.25-0.67), 0.17% (95% CI; -0.03-0.37) for males and 0.65% (95% CI; 0.32-0.98) for females. The prevalence of RA was highest in the Northern region (2.00%) and the prevalence of SpA was highest in the Central region (1.49%). CONCLUSION: The prevalences of RA and SpA in Turkey are close to each other and there are significant inter-regional variations in prevalences of both RA and SpA