Numerical investigation of highly curved turbulent flows in centrifugal compressors and in a simplified geometry

Curvature effects are investigated in terms of a recently developed curvature corrected turbulence model in turbomachinery applications. Two centrifugal compressor stages and a curved geometry modelled after a centrifugal impeller are simulated using the curvature corrected SST (SST-CC) turbulence model. This work improves the understanding of how the SST-CC model predicts curvature effects. An analysis of the SST-CC production multiplier in both centrifugal cases reveals that the model is appropriately accounting for curvature effects, showing increased production near concave surfaces and decreased production near convex surfaces. This correlates well with the simplified geometry results and demonstrates that the simplified geometry is successfully capturing the curvature effects of the centrifugal stages. A detailed investigation of turbulence quantities in the simplified geometry further demonstrated how curvature effects are predicted by the SST-CC model. Future work will include experimentation on the 1C stage and further comparison with numerical results

Democracy and the Epistemic Limits of Markets

A recent line of argument insists that replacing democracy with markets would improve social decision making due to markets’ superior use of knowledge. These arguments are flawed by unrealistic assumptions, unfair comparisons, and a neglect of the epistemic limits of markets. In reality, the epistemic advantages of markets over democracy are circumscribed and often illusory. A recognition of markets’ epistemic limits can, however, provide guidance for designing institutions in ways that capture the advantages of both

Positional Authority and Influence in Servant Leadership: A Conceptual Model

This conceptual research paper reviews how positional authority affects the servant leadership-organizational performance relationship and provides insight on how servant leadership can be implemented and effective in the absence of positional authority, i.e. through the cultivation and leveraging of influence. A review of servant leadership literature is used to propose that servant leadership is positively associated with increased organizational performance. Through the lens of upper echelon theory as well as research on the performance of organizations whose executive team practices servant leadership, we develop a model and make a case that positional authority is an important moderator of the relationship between servant leadership and organizational performance. Our model also considers the contingency that not all leaders in an organization are in a position of authority. As such, we review the servant leadership example of Jesus Christ to understand how servant leadership can be implemented in the absence of positional authority

Moral Molecules and Love Drugs: Objectivity, Understanding, and Backtracking

A case study of the ways that research on genetic and neurochemical changes that affect the social and sexual behavior of voles gets framed in the media illustrates the tensions science communicators often face between the dual goals of promoting public understanding while maintaining their objectivity. As a response to this ethical challenge, we argue that communicators could improve existing practices by striving to enable “backtracking.

The Ethics of Infection Control: Philosophical Frameworks

Recent developments that are relevant to the ethics of infection control include the patient safety movement, the appearance of new diseases (notably, severe acute respiratory syndrome) that pose threats to healthcare workers, data confirming the suspicion that infection control measures such as isolation may compromise patient care, and, in philosophy, renewed interest in virtue ethics and communitarianism. We review general ethical frameworks and relevant vocabulary for infection control practitioners and hospital epidemiologists. Frameworks for the ethics of infection control resemble those of public health more than those of clinical medicine but embrace elements of both. The optimum framework, we suggest, takes into account a virtue-based communitarianism. The virtue ethics movement stresses the need to consider not only rules and outcomes but also the character of the individual(s) involved. Communitarianism emphasizes the well-being and values of local communities, best determined by shared, democratic decision making among stakeholders. Brief discussions of 15 consecutive cases illustrate the extent to which the daily practice of infection control poses problems heavily freighted with ethical overtones

A Framework for Biometric and Interaction Performance Assessment of Automated Border Control Processes

Automated Border Control (ABC) in airports and land crossings utilize automated technology to verify passenger identity claims. Accuracy, interaction stability, user error, and the need for a harmonized approach to implementation are required. Two models proposed in this paper establish a global path through ABC processes. The first, the generic model, maps separately the enrolment and verification phases of an ABC scenario. This allows a standardization of the process and an exploration of variances and similarities between configurations across implementations. The second, the identity claim process, decomposes the verification phase of the generic model to an enhanced resolution of ABC implementations. Harnessing a human-biometric sensor interaction framework allows the identification and quantification of errors within the system's use, attributing these errors to either system performance or human interaction. Data from a live operational scenario are used to analyze behaviors, which aid in establishing what effect these have on system performance. Utilizing the proposed method will aid already established methods in improving the performance assessment of a system. Through analyzing interactions and possible behavioral scenarios from the live trial, it was observed that 30.96% of interactions included some major user error. Future development using our proposed framework will see technological advances for biometric systems that are able to categorize interaction errors and feedback appropriately

Análisis de proyección de saturación del espectro electromagnético en la banda no licenciada de 5 GHz en la ciudad de Salta y su impacto en el despliegue de otras tecnologías

Debido a la reciente experiencia en la cual la banda de 2.4 GHz se vio saturada en puntos de grandes concentraciones de personas, a causa que la tecnología Wifi es cada vez más requerida y con mayor ancho de banda, es necesario realizar un análisis de la situación actual en Salta sobre las redes inalámbricas y proyectar si la banda de 5 GHZ corre con el mismo destino. Esto nos podría dar un estimativo del tiempo en el cual se podría empezar a generar inconvenientes, evaluar alternativas de solución e implementarlas de manera precautoria y no cuando los problemas ya hayan aparecido...Fil: Cavalli Delgado, Rafael Duilio. Universidad Católica de Salta. Facultad de Ingeniería; Argentina.Fil: Lagoria, Guillermo J.. Universidad Católica de Salta. Facultad de Ingeniería; Argentina.Fil: Elliott, Kevin G.. Universidad Católica de Salta. Facultad de Ingeniería; Argentina

Mid-term functional outcome after the internal fixation of distal radius fractures

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.Abstract Background Distal radius fracture is a common injury with a variety of operative and non-operative management options. There remains debate as to the optimal treatment for a given patient and fracture. Despite the popularity of volar locking plate fixation, there are few large cohort or long term follow up studies to justify this modality. Our aim was to report the functional outcome of a large number of patients at a significant follow up time after fixation of their distal radius with a volar locking plate. Methods 180 patients with 183 fractures and a mean age of 62.4 years were followed up retrospectively at a mean of 30 months (Standard deviation = 10.4). Functional assessment was performed using the Disabilities of the Arm, Shoulder and Hand (DASH) and modified MAYO wrist scores. Statistical analysis was performed to identify possible variables affecting outcome and radiographs were assessed to determine time to fracture union. Results The median DASH score was 2.3 and median MAYO score was 90 for the whole group. Overall, 133 patients (74%) had a good or excellent DASH and MAYO score. Statistical analysis showed that no specific variable including gender, age, fracture type, post-operative immobilisation or surgeon grade significantly affected outcome. Complications occurred in 27 patients (15%) and in 11 patients were major (6%). Conclusion This single centre large population series demonstrates good to excellent results in the majority of patients after volar locking plate fixation of the distal radius, with complication rates comparable to other non-operative and operative treatment modalities. On this basis we recommend this mode of fixation for distal radius fractures requiting operative intervention.Peer Reviewe

Electrical properties of Bi-implanted amorphous chalcogenide films

The impact of Bi implantation on the conductivity and the thermopower of amorphous chalcogenide films is investigated. Incorporation of Bi in Ge-Sb-Te and GeTe results in enhanced conductivity. The negative Seebeck coefficient confirms onset of the electron conductivity in GeTe implanted with Bi at a dose of 2x1016 cm-2. The enhanced conductivity is accompanied by defect accumulation in the films upon implantation as is inferred by using analysis of the space-charge limited current. The results indicate that native coordination defects in lone-pair semiconductors can be deactivated by means of ion implantation, and higher conductivity of the films stems from additional electrically active defects created by implantation of bismuth.Comment: This is an extended version of the results presented in Proc. SPIE 8982, 898213 (2014