Diverse virtual social networks: Implications for remote software testing teams

This paper evaluates offshore outsourcing in the IT testing industry and determines what conditions determine its success. There is particular focus on the influence of diversity in teams on group relationships. Two studies are described: the first, investigated the perceptions of professional software testers on the critical factors of offshore outsourcing; and the second study looked at the ability for diverse teams to form close working relationships through virtual networks. We find that overt diversity factors inhibit interaction across nationality boundaries. The limitations of virtual networks for fostering personal communications is apparent in preventing group members from overcoming the initial aversion to mix with out-group members, which could be achieved with closer and more personal communications between members with different diversity factors in normal face to face communications. Where software testing teams are outsourced globaly, and must rely on virtual communications, there seems potential for significant difficulties in developing close working relationships, which on the one hand, can be negative for group cohesion, but one the other hand, can be positive for encouraging imparitality

Numerical study of a hybrid photovoltaic/thermal PVT solar collector using three different fluids

Hybrid photovoltaic and thermal (PV/T) systems have been widely used for the combination of PV modules and solar thermal collectors to generate both electrical energy and heat at the same time. In the present work, a numerical model has been developed to simulate the performances of a hybrid photovoltaic/thermal (PV/T) solar collector. Furthermore, a comparative study has been performed between the hybrid PV/T working with three conventional working fluids; air, water, and specified nanofluid (AL2O3+ water). The obtained results show that the use of the Alumina nanofluid is the best choice to increase the heat removal, and to improve the performances of the collector with the values of 73.28%, 10.37% and 99.21% for the thermal, the electrical and the global efficiency respectively. On the other hand, the PVT collector working with air as the primary fluid is the worst in terms of electrical, thermal, and global performances with the lowest values of 9.506 %, 41.55%, and 65.315% respectively

Titanium Nitride Coating as a Multipactor Suppressor

WEPEC002International audienceLAL-Orsay is developing an important effort on R&D and technology studies on RF power couplers for superconductive cavities. One of the most critical components of those devices is the ceramic RF window that allows the power flux to be injected in the coaxial line. The presence of a dielectric window on a high power RF line has a strong influence on the multipactor phenomena. The most important method to reduce the multipactor is to decrease the secondary emission yield of the ceramic window. Due to its low Secondary electron Emission Yield (SEY), TiN thin film is used as a multipactor suppressor coating on RF ceramic coupler windows. In this frame work, TiN deposition was made by magnetron reactive sputtering. XPS and XRD analysis were performed to control the film composition and stoechiometry. Coating thickness was optimized so that the TiN coating effectively reduces the SEY but does not cause excessive heating, due to ohmic loss. For this purpose, SEY measurements on covered and uncovered TiN Alumina substrates, multipactor level breakdown on TiN coated Cupper substrates and RRR measurements were performed for different deposit thicknesses

Titanium Nitride Coating as a Multipactor Suppressor on RF Coupler Ceramic Windows

International audienceLAL-Orsay is developing an important effort on R&D studies on RF power couplers. One of the most critical components of those devices is the ceramic RF window that allows the power flux to be injected in the coaxial line. The presence of a dielectric window on a high power RF line has a strong influence on the multipactor phenomena. To reduce this effect, the decrease the secondary emission yield (SEY)of the ceramic window is needed. Due to its low SEY coefficient, TiN coating is used for this goal. In this framework, a TiN sputtering bench has been developed in LAL. The reactive sputtering of TiN needs the optimisation of gas flow parameters and electrical one, to obtain stoechiometric deposit. XRD analysis was performed to control the film composition and stoechiometry. Measurements point out how the Nitrogen vacancy on the film can be controlled acting on the N2 flow. In addition, the coating thickness must be optimized so that the TiN coating effectively reduces the SEY coefficient but does not cause excessive heating, due to ohmic loss. For this purposes, multipactor level breakdown and resistance measurements were done for different deposit thickness

Acute One-Cigarette Smoking Decreases Ghrelin Hormone in Saliva: A Pilot Study

Cigarette smoking is commonly associated with weight loss and mechanisms for these weight changes are still elusive. Ghrelin is a peptide hormone that works in a neuroendocrine fashion to stimulate hunger and the desire for food intake. Ghrelin is also secreted in saliva, probably to enhance food taste. In the current study, we tested the direct impact of acute cigarette smoking on total ghrelin found in saliva. Methods. Blood and saliva samples were collected from 30 healthy nonsmoker male volunteers before and after one-cigarette smoke. Total ghrelin in serum and saliva was measured by ELISA based method. Results. Data showed a statistically significant reduction in salivary ghrelin after smoking ( < 0.0001). In serum, total ghrelin levels were not affected before and after smoking ( = 0.1362). Additionally, positive correlation was observed between serum and salivary ghrelin before smoking ( = 0.4143 and = 0.0158); however, this correlation was lost after smoking ( = 0.1147 and = 0.5461). Conclusion. Acute one-cigarette smoking can negatively affect ghrelin levels in saliva that might contribute to the dull food taste in smokers

Acute One-Cigarette Smoking Decreases Ghrelin Hormone in Saliva: A Pilot Study

Cigarette smoking is commonly associated with weight loss and mechanisms for these weight changes are still elusive. Ghrelin is a peptide hormone that works in a neuroendocrine fashion to stimulate hunger and the desire for food intake. Ghrelin is also secreted in saliva, probably to enhance food taste. In the current study, we tested the direct impact of acute cigarette smoking on total ghrelin found in saliva. Methods. Blood and saliva samples were collected from 30 healthy nonsmoker male volunteers before and after one-cigarette smoke. Total ghrelin in serum and saliva was measured by ELISA based method. Results. Data showed a statistically significant reduction in salivary ghrelin after smoking (P<0.0001). In serum, total ghrelin levels were not affected before and after smoking (P=0.1362). Additionally, positive correlation was observed between serum and salivary ghrelin before smoking (r=0.4143 and P=0.0158); however, this correlation was lost after smoking (r=0.1147 and P=0.5461). Conclusion. Acute one-cigarette smoking can negatively affect ghrelin levels in saliva that might contribute to the dull food taste in smokers