Interferometric investigations of compressible dynamic stall over a transiently pitching airfoil

The dynamic stall flow field over NACA 0012 airfoil pitching transiently from 0 - 60 at a constant rate under compressible flow conditions has been studied using the real-time technique of point diffraction interferometry. This investigation using nonintrusive diagnostics provides a quantitative description of the overall flow field, including the finer details of dynamic stall vortex formation, growth and the concomitant changes in the pressure distribution. Analysis of several hundred interferograms obtained for a range of flow conditions shows that the peak leading edge suction pressure coefficient that stall is nearly constant for a given free stream Mach number at all nondimensional pitch rates. Also, this value is below that seen in steady flow at static stall for the same Mach number, indicating that dynamic effects significantly effect the separation behavior. Further, for a given Mach number, the dynamic stall vortex seems to form rapidly at nearly the same angle of attack for all pitch rates studied. As the vortex is shed, it induces an anti-clockwise trailing edge vortex, which grows in a manner similar to that of a starting vortex. The measured peak suction pressure coefficient drops as the free stream Mach number increases. For free stream Mach numbers above 0.4, small multiple shocks appear near the leading edge

Modeling and Simulation of Coating Growth on Nanofibers

This work presents modeling and simulation results of a procedure to coat nanofibers and core-clad nanostructures with thin film materials using plasma enhanced physical vapor deposition. In the experimental effort that motivates the modeling, electrospun polymer nanofibers are coated with metallic materials under different operating conditions to observe changes in the coating morphology. The modeling effort focuses on linking simple models at the reactor, nanofiber, and atomic levels to form a comprehensive model. Numerical simulations that link the concentration field with the evolution of the coating free surface predict that as the Damkohler number is increased the coating morphology changes from a wavy to a nodular to a dendritic needle-type form as observed experimentally

Zika virus tropism and interactions in myelinating neural cell cultures: CNS cells and myelin are preferentially affected

The recent global outbreak of Zika virus (ZIKV) infection has been linked to severe neurological disorders affecting the peripheral and central nervous systems (PNS and CNS, respectively). The pathobiology underlying these diverse clinical phenotypes are the subject of intense research; however, even the principal neural cell types vulnerable to productive Zika infection remain poorly characterised. Here we used CNS and PNS myelinating cultures from wild type and Ifnar1 knockout mice to examine neuronal and glial tropism and short-term consequences of direct infection with a Brazilian variant of ZIKV. Cell cultures were infected pre- or post-myelination for various intervals, then stained with cell-type and ZIKV-specific antibodies. In bypassing systemic immunity using ex vivo culture, and the type I interferon response in Ifnar1 deficient cells, we were able to evaluate the intrinsic infectivity of neural cells. Through systematic quantification of ZIKV infected cells in myelinating cultures, we found that ZIKV infection is enhanced in the absence of the type I interferon responses and that CNS cells are considerably more susceptible to infection than PNS cells. In particular, we demonstrate that CNS axons and myelinating oligodendrocytes are especially vulnerable to injury. These results have implications for understanding the pathobiology of neurological symptoms associated with ZIKV infection. Furthermore, we provide a quantifiable ex vivo infection model that can be used for fundamental and therapeutic studies on viral neuroinvasion and its consequences

Ortaokul Öğrencilerinde Matematik Kaygısı ile Duygu Düzenleme ve Psikolojik Sağlamlık Arasındaki İlişkinin İncelenmesi

Mathematics anxiety is seen as one of the important obstacles to students' learning mathematics. Because when the feeling of anxiety is experienced at an intense level, it can affect brain functionality and inhibit learning. Therefore, regulating intense emotions such as anxiety, in other words, recognizing, naming, expressing and reducing them to a tolerable level, can eliminate this obstacle to learning. Psychological resilience is defined as a person's ability to successfully cope with stressful and challenging situations. Another reason for math anxiety may be low levels of psychological resilience. In this study, the relationship between emotional regulation skills and psychological resilience level and mathematics anxiety was examined. Data was collected from 937 students continuing their education in secondary schools in Bayraklı district of Izmir province. The data collection tools used in this research are the Emotion Regulation Scale for Adolescents (EDRS), Mathematics Anxiety Scale, Child and Youth Psychological Resilience Scale and Personal Information Form. The data was analyzed with the Multiple Regression Analysis technique using the SPSS 23 package program. The results showed that emotional regulation skills and psychological resilience variables explained 25% of mathematics anxiety. Additionally, there is a negative relationship between having internal functional emotion regulation skills and math anxiety; A positive relationship was found between having dysfunctional emotion regulation skills and mathematics anxiety

Heart rate changes during partial seizures: A study amongst Singaporean patients

INTRODUCTION: Studies in Europe and America showed that tachycardia, less often bradycardia, frequently accompanied partial seizures in Caucasian patients. We determine frequency, magnitude and type of ictal heart rate changes during partial seizures in non-Caucasian patients in Singapore. METHODS: Partial seizures recorded during routine EEGs performed in a tertiary hospital between 1995 and 1999 were retrospectively reviewed. All routine EEGs had simultaneous ECG recording. Heart rate before and during seizures was determined and correlated with epileptogenic focus. Differences in heart rate before and during seizures were grouped into 4 types: (1) >10% decrease; (2) -10 to +20% change; (3) 20–50% increase; (3) >50% increase. RESULTS: Of the total of 37 partial seizures, 18 were left hemisphere (LH), 13 were right hemisphere (RH) and 6 were bilateral (BL) in onset. 51% of all seizures showed no significant change in heart rate (type 2), 22% had moderate sinus tachycardia (type 3), 11% showed severe sinus tachycardia (type 4), while 16% had sinus bradycardia (type 1). Asystole was recorded in one seizure. Apart from having more tachycardia in bilateral onset seizures, there was no correlation between side of ictal discharge and heart rate response. Compared to Caucasian patients, sinus tachycardia was considerably less frequent. Frequency of bradycardia was similar to those recorded in the literature. CONCLUSIONS: Significant heart rate changes during partial seizures were seen in half of Singaporean patients. Although sinus tachycardia was the most common heart rate change, the frequency was considerably lower compared to Caucasian patients. This might be due to methodological and ethnic differences. Rates of bradycardia are similar to those recorded in the literature

Using On-Farm Demonstrations to Evaluate Newly Developed Cool-Season Forages in the Southeastern USA

Multiple demonstration sites throughout Florida were designed to evaluate and provide hands-on producer and county faculty access to newly developed cool-season winter forage crops that can be grown in the southeastern United States. Research funding for these projects was provided by the Dairy Research and Education Project, supported through the Georgia/Florida Dairy Industry check-off dollars. Early adopter producers interested in evaluating forages were identified for this cooperation. Long-term goals are to have the early adopter producer aid in the trialing and dissemination of information about improved varieties. Cool-season forages for use on southeastern US livestock operations benefit the producer in providing highly nutritional greenchop or silage crop for livestock, winter cover to provide erosion and leaching protection on cultivated acreage, potentially recycle nutrients or remove significant nutrients from the forage system, and serve as a sentinel plots to help identify new or emerging pest problems related to forage production. We also focus developing forages for both low and high end input systems that address environmental issues related to N and P in the soils. In the southeastern U.S. particularly in Florida, nitrogen and phosphorus accumulate in many production fields and these nutrients impact surface and ground water resources. We participate with the Florida Department of Agriculture and the dairy and beef cattle industry to develop “best management practices” (BMPs) that guide producers to lessen their negative impacts on the environment and improve upon their operation’s sustainability and economic returns. This effort has led to the release of new cultivars from the University of Florida’s Forage Program. While we focus, primarily, on cool-season small grains and ryegrass, our program also includes breeding other subtropical forage species for adaptation to our environment and to improve adoption of BMPs