A viscous shock-layer flowfield analysis by an explicit-implicit method

An implicit analogue of a widely used explicit method to external axisymmetric laminar flows with strong entropy gradients is extended. The details of the "numerics" of the implicit part are provided in a body oriented coordinate system with a moving outer (shock) boundary during the transient part of the solutions. The limiting values of the Courant number are obtained when the shock boundary is treated explicitly. The solution algorithm outlined includes the treatment of the source term associated with the equations in weak conservation form. From the results obtained for two sample problems, it becomes clear that accuracy of predictions is, indeed, very good at higher values of the Courant number. There is a significant saving in overall computing time, depending on the Courant number used and the flow Reynolds number. These properties combined with the simplicity of programming the implicit analog may appeal to researchers for using it in the analysis of 3-D flow problems

Coordination Implications of Software Coupling in Open Source Projects

The effect of software coupling on the quality of software has been studied quite widely since the seminal paper on software modularity by Parnas [1]. However, the effect of the increase in software coupling on the coordination of the developers has not been researched as much. In commercial software development environments there normally are coordination mechanisms in place to manage the coordination requirements due to software dependencies. But, in the case of Open Source software such coordination mechanisms are harder to implement, as the developers tend to rely solely on electronic means of communication. Hence, an understanding of the changing coordination requirements is essential to the management of an Open Source project. In this paper we study the effect of changes in software coupling on the coordination requirements in a case study of a popular Open Source project called JBoss

The value of the human

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Excavation and Survey in the Jabbul Plain, Western Syria: The Umm el-Marra Project 1996-1997

The 1996 and 1997 seasons of the Hopkins-Amsterdam project in the Jabbul plain, western Syria, have generated new results on Bronze Age urbanism at Tell Umm el- Marra and elucidated longer-term settlement patterns in the Jabbul region. Excavation results have documented the foundation of Umm el-Marra as a regional center in the Early Bronze Age, provided new data on a period of decentralization in Middle Bronze I, and supplied evidence of the regeneration of urbanism in MB II. Faunal and archaeobotanical analysis broaden our understanding of these developments, attesting to an economy overwhelmingly dependent on the steppe environment, with an emphasis on large-scale onager hunting in MB II. Finally, a regional survey provides data on long-term demographic and socioeconomic trends, furnishing an expansive time range and spatial context for our under- standing of developmental patterns in the region. The survey results supply new information on the limits of the Uruk expansion, cycles of Bronze Age urbanization, changing patterns of steppe exploitation, and demo- graphic and agricultural extensification in the Byzantine and Early Islamic periods

The role of language in emotion: predictions from psychological constructionism

Common sense suggests that emotions are physical types that have little to do with the words we use to label them. Yet recent psychological constructionist accounts reveal that language is a fundamental element in emotion that is constitutive of both emotion experiences and perceptions. According to the psychological constructionist Conceptual Act Theory (CAT), an instance of emotion occurs when information from one’s body or other people’s bodies is made meaningful in light of the present situation using concept knowledge about emotion. The CAT suggests that language plays a role in emotion because language supports the conceptual knowledge used to make meaning of sensations from the body and world in a given context. In the present paper, we review evidence from developmental and cognitive science to reveal that language scaffolds concept knowledge in humans, helping humans to acquire abstract concepts such as emotion categories across the lifespan. Critically, language later helps individuals use concepts to make meaning of on-going sensory perceptions. Building on this evidence, we outline predictions from a psychological constructionist model of emotion in which language serves as the “glue” for emotion concept knowledge, binding concepts to embodied experiences and in turn shaping the ongoing processing of sensory information from the body and world to create emotional experiences and perceptions

Characterization of a sodium dodecyl sulphate-degrading Pseudomonas sp. strain DRY15 from Antarctic soil

A bacterium capable of biodegrading surfactant sodium dodecyl sulphate (SDS) was isolated from Antarctic soil. The isolate was tentatively identified as Pseudomonas sp. strain DRY15 based on carbon utilization profiles using Biolog GN plates and partial 16S rDNA molecular phylogeny. Growth characteristic studies showed that the bacterium grew optimally at 10 degrees C, 7.25 pH, 1 g l(-1) SDS as a sole carbon source and 2 g l(-1) ammonium sulphate as nitrogen source. Growth was completely inhibited at 5 g l(-1) SDS. At a tolerable initial concentration of 2 g l(-1), approximately 90% of SDS was degraded after an incubation period of eight days. The best growth kinetic model to fit experimental data was the Haldane model of substrate inhibition with a correlation coefficient value of 0.97. The maximum growth rate was 0.372 hr(-1) while the saturation constant or half velocity constant (Ks) and inhibition constant (Ki), were 0.094% and 11.212 % SDS, respectively. Other detergent tested as carbon sources at 1 g l(-1) was Tergitol NP9, Tergitol 15S9, Witconol 2301 (methyl oleate), sodium dodecylbenzene sulfonate (SDBS), benzethonium chloride, and benzalkonium chloride showed Tergitol NP9, Tergitol 15S9, Witconol 2301 and the anionic SDBS supported growth with the highest growth exhibited by SDBS.Fil: Halmi, M. I. E.. University of Putra; MalasiaFil: Hussin, W. S. W.. University of Putra; MalasiaFil: Aqlima, A.. University of Putra; MalasiaFil: Syed, M. A.. University of Putra; MalasiaFil: Ruberto, Lucas Adolfo Mauro. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: MacCormack, Walter P.. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Yukor, M. Y.. University of Putra; Malasi

Effect of Applied Magnetic Field on Shock Boundary Layer Interaction

The governing magneto-hydrodynamic (MHD) equations contain classical fluid dynamics equations along with coupled Maxwell’s magnetic induction equations. These equations model both advection and diffusion effects of electromagnetic field. However, available literature indicates that some previous investigations neglect the diffusion of magnetic field and considered only ideal MHD equations for modeling a typical MHD problem. In this work, the effects of magnetic field diffusion term also known as viscous magnetic term have been investigated over flow structure. Low magnetic Reynolds number approximation and ideal full MHD set of equations have been considered and solved using a four-stage modified Runge-Kutta scheme augmented with the Davis-Yee symmetric Total Variation Diminishing model in post-processing stage. Results obtained from viscous and ideal flow computations without applied magnetic field have been found in close agreement. However, results obtained from viscous MHD and ideal MHD computations substantially disagree from each other which indicate that the effect of magnetic diffusion term on overall flow structure is significant

Determinants for the success of software startups: Insights from a regional cluster

In recent years, we have seen a growing interest in technology-based companies and intensive knowledge. Several regional clusters have appeared supported in dynamic entrepreneurial ecosystems which, alongside intrinsic aspects of the business, are important determinants of the success of new companies. However, most startups created in these innovation-oriented spaces do not survive the first years of life, due to the high competitiveness of the technological market, due to deficiencies in the business model, due to the support conditions provided by the surrounding ecosystem, and finally due to a weak adjustment between all these dimensions. Among several models available, the Early-Life Decision Model (ELDM) presents itself as an interesting framework for studying the development and success conditions of software companies. This article discusses the application of the ELDM based on a series of interviews conducted to 15 Portuguese software startups installed in a technological cluster located in the northeast of Portugal. Based on the results obtained, it was appropriate to add a new dimension to the ELDM model (learning) and complementing it with the perspectives of the business type and internal versus external determinants.This work was supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT (Fundação para a Ciência e a Tecnologia) within the Project Scope: UID/CEC/00319/2013