1,370 research outputs found
Nonlinear model predictive control of an Organic Rankine Cycle for exhaust waste heat recovery in automotive engines
Energy recovery from exhaust gas waste heat can be regarded as an effective way to improve the energy efficiency of automotive powertrains, thus reducing CO2 emissions. The application of Organic Rankine Cycles (ORCs) to waste heat recovery is a solution that couples effectiveness and reasonably low technological risks. On the other hand, ORC plants are rather complex to design, integrate and control, due to the presence of heat exchangers operating with phase changing fluid, and several control devices to regulate the thermodynamic states of the systems. Furthermore, the power output and efficiency of ORC systems are extremely sensitive to the operating conditions, requiring precise control of the evaporator pressure and superheat temperature. This paper presents an optimization and control design study for an Organic Rankine Cycle plant for automotive engine waste heat recovery. The analysis has been developed using a detailed Moving Boundary Model that predicts mass and energy flows through the heat exchangers, valves, pumps and expander, as well as the system performance. Starting from the model results, a nonlinear model predictive controller is designed to optimize the transient response of the ORC system. Simulation results for an acceleration-deceleration test illustrate the benefits of the proposed control strategy
The comparison of latero-medial versus dorso-palmar/plantar drilling for cartilage removal in the proximal interphalangeal joint
The aims of the present study were to compare the percentages of articular cartilage removed using a lateral drilling approach of the proximal interphalangeal joint (PIPJ) and a dorsal drilling approach, and to assess the usefulness of digital fluoroscopy when performing a lateral drilling approach. Sixty cadaveric PIPJs were drilled using a surgical drill bit to remove the articular cartilage. The limbs were divided into three groups containing 10 forelimbs and 10 hindlimbs each. One group received the dorsal drilling approach, the second one received the lateral drilling approach and the last one received the lateral drilling approach under digital fluoroscopy guidance. The percentage of articular cartilage removed from each articular surface was assessed using Adobe Photoshop® software. The percentages of removed cartilage turned out to be significantly higher with lateral approach, especially under fluoroscopic guidance, both in the forelimbs (p = 0.00712) and hindlimbs (p = 0.00962). In conclusion, the lateral drilling approach seems to be a minimally invasive technique with which to perform PIPJ arthrodesis, even more efficient than the previously reported dorsal approach
Diversity of actinobacteria in the rhizosphere of the typical mangrove tree Rhizophora mangle.
Expression of innate immune complement regulators on brain epithelial cells during human bacterial meningitis
BACKGROUND: In meningitis, the cerebrospinal fluid contains high levels of innate immune molecules (e.g. complement) which are essential to ward off the infectious challenge and to promote the infiltration of phagocytes (neutrophils, monocytes). However, epithelial cells of either the ependymal layer, one of the established niche for adult neural stem cells, or of the choroid plexus may be extremely vulnerable to bystander attack by cytotoxic and cytolytic complement components. METHODS: In this study, we assessed the capacity of brain epithelial cells to express membrane-bound complement regulators (ie, CD35, CD46, CD55 and CD59) in vitro and in situ by immunostaining of control and meningitis human brain tissue sections. RESULTS: Double immunofluorescence experiments for ependymal cell markers (GFAP, S100, ZO-1, E-cadherin) and complement regulators indicated that the human ependymal cell line model was strongly positive for CD55, CD59 compared to weak stainings for CD46 and CD35. In tissues, we found that CD55 was weakly expressed in control choroid plexus and ependyma but was abundantly expressed in meningitis. Anti-CD59 stained both epithelia in apical location while increased CD59 staining was solely demonstrated in inflamed choroid plexus. CD46 and CD35 were not detected in control tissue sections. Conversely, in meningitis, the ependyma, subependyma and choroid plexus epithelia were strongly stained for CD46 and CD35. CONCLUSION: This study delineates for the first time the capacity of brain ependymal and epithelial cells to respond to and possibly sustain the innate complement-mediated inflammatory insult
Learn to Spot Phishing URLs with the Android NoPhish App
Part 3: Tools and Applications for TeachingInternational audiencePhishing is a münich issue in today’s Internet. It can have financial or personal consequences. Attacks continue to become more and more sophisticated and the advanced ones (including spear phishing) can only be detected if people carefully check URLs – be it in messages or in the address bar of the web browser. We developed a game-based smartphone app – NoPhish – to educate people in accessing, parsing and checking URLs; i.e. enabling them to distinguish between trustworthy and non-trustworthy messages and websites. Throughout several levels of the game information is provided and phishing detection is exercised in a playful manner. Several learning principles were applied and the interfaces and texts were developed in a user-centered design
Are welders more at risk of respiratory infections? Findings from a cross-sectional survey and analysis of medical records in shipyard workers: the WELSHIP project
Background Exposure to welding fume increases the risk of pneumococcal infection; whether such susceptibility extends to other respiratory infections is unclear. We report findings from a survey and from medical consultation data for workers in a large shipyard in the Middle East. Methods Between January 2013 and December 2013, we collected cross-sectional information from 529 male workers variously exposed to welding fume. Adjusted ORs for respiratory symptoms (cough, phlegm, wheezing, shortness of breath and 'chest illness') were estimated using multivariable logistic regression. Subsequently, we examined consultation records from 2000 to 2011 for 15 954 workers who had 103 840 consultations for respiratory infections; the associations between respiratory infections and levels of welding exposure were estimated using a count regression model with a negative binomial distribution. Results 13% of surveyed workers reported respiratory symptoms with a higher prevalence in winter, particularly among welders. The adjusted OR in welders versus other manual labourers was 1.72 (95% CI 1.02 to 3.01) overall and 2.31 (1.05 to 5.10) in winter months; no effect was observed in summer. The risk of consultation for respiratory infections was higher in welders than in manual labourers, with an adjusted incidence rate ratio of 1.45 (1.59 to 1.83) overall, 1.47 (1.42 to 1.52) in winter and 1.33 (1.23 to 1.44) in summer (interaction, p<0.001). Conclusions The observation that respiratory symptoms and consultations for respiratory infection in welders are more common in winter may indicate an enhanced vulnerability to a broad range of infections. If confirmed, this would have important implications for the occupational healthcare of a very large, global workforce
Ética climática, (in)justiças e limitações do Pagamento por Serviços Ambientais no Brasil
Resumo Este artigo analisa, sob a ótica da ética climática, as políticas de Pagamento por Serviços Ambientais nas dimensões local (PSA em São Paulo) e nacional (Plano Nacional de PSA) e o nexo indissociável entre a ética e a dimensão política brasileira. Essa conexão remete a uma reflexão teórica entre as políticas de PSA e o confronto de princípios éticos, por vezes antagônicos. As práticas observadas nas arenas políticas brasileiras foram avaliadas via análise de conteúdo à luz das seguintes categorias: Pluralidade decisória, Localidade energética, Acesso ao conhecimento e ao recurso material, Naturalização planejada e Benefício geracional (PLANB Index). As análises dos resultados transferem à urgência de políticas climáticas alinhadas a um horizonte ético normativo que reduza as iniquidades sociais e climáticas simultaneamente, as quais devem considerar, em termos de escala, as perspectivas locais e o tempo de implementação em sintonia com os acordos globais multilaterais
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