Characteristics of polar coronal hole jets

High spatial- and temporal-resolution images of coronal hole regions show a dynamical environment where mass flows and jets are frequently observed. These jets are believed to be important for the coronal heating and the acceleration of the fast solar wind. We studied the dynamics of two jets seen in a polar coronal hole with a combination of imaging from EIS and XRT onboard Hinode. We observed drift motions related to the evolution and formation of these small-scale jets, which we tried to model as well. We found observational evidence that supports the idea that polar jets are very likely produced by multiple small-scale reconnections occurring at different times in different locations. These eject plasma blobs that flow up and down with a motion very similar to a simple ballistic motion. The associated drift speed of the first jet is estimated to be $\approx$ 27 km s$^{-1}$. The average outward speed of the first jet is $\approx 171$ km s$^{-1}$, well below the escape speed, hence if simple ballistic motion is considered, the plasma will not escape the Sun. The second jet was observed in the south polar coronal hole with three XRT filters, namely, C$_{-}$poly, Al$_{-}$poly, and Al$_{-}$mesh filters. We observed that the second jet drifted at all altitudes along the jet with the same drift speed of $\simeq$ 7 km s$^{-1}$. The enhancement in the light curves of low-temperature EIS lines in the later phase of the jet lifetime and the shape of the jet's stack plots suggests that the jet material is falls back, and most likely cools down. To support this conclusion, the observed drifts were interpreted within a scenario where reconnection progressively shifts along a magnetic structure, leading to the sequential appearance of jets of about the same size and physical characteristics. On this basis, we also propose a simple qualitative model that mimics the observations.Comment: Accepted Astronomy and Astrophysic

Management of business process reengineering projects: a case study

Business process reengineering (BPR) projects are undertaken by outward-looking companies that are looking for significant change in their performance and wanting radical changes in the chosen parameters. Generally, these companies are trendsetters in their respective industries. BPR projects take longer time for completion and may require significant capital inflows as well. This paper discusses BPR, special requirements/considerations for BPR project management and, through a case analysis, seeks to identify and emphasise the critical success factors for the implementation of a BPR projec

On Demand Feedback Analysis for Certification Process

Many companies provide certifications to other vendors to validate that the vendor’s product functions efficiently on their technology. But it so happens that the process of certification might take longer due to errors that pop up which the vendors will not be able to resolve. The vendors need to resolve the errors with the help of product owner’s engineers which is a lengthy and less efficient process. With this in regard, the solution of on-demand feedback analysis of the certification process proposed in this paper helps minimize the delay in the certification process

Carrier Recombination and Generation Rates for Intravalley and Intervalley Phonon Scattering in Graphene

Electron-hole generation and recombination rates for intravalley and intervalley phonon scattering in Graphene are presented. The transverse and the longitudinal optical phonon modes ($E_{2g}$-modes) near the zone center ($\Gamma$-point) contribute to intravalley interband carrier scattering. At the zone edge ($K(K')$-point), only the transverse optical phonon mode ($A'_{1}$-mode) contributes significantly to intervalley interband scattering with recombination rates faster than those due to zone center phonons. The calculated recombination times range from less than a picosecond to more than hundreds of picoseconds and are strong functions of temperature and electron and hole densities. The theoretical calculations agree well with experimental measurements of the recombination rates of photoexcited carriers in graphene.Comment: 6 pages, 9 figure

Multiple exposures to swine barn air induce lung inflammation and airway hyper-responsiveness

BACKGROUND: Swine farmers repeatedly exposed to the barn air suffer from respiratory diseases. However the mechanisms of lung dysfunction following repeated exposures to the barn air are still largely unknown. Therefore, we tested a hypothesis in a rat model that multiple interrupted exposures to the barn air will cause chronic lung inflammation and decline in lung function. METHODS: Rats were exposed either to swine barn (8 hours/day for either one or five or 20 days) or ambient air. After the exposure periods, airway hyper-responsiveness (AHR) to methacholine (Mch) was measured and rats were euthanized to collect bronchoalveolar lavage fluid (BALF), blood and lung tissues. Barn air was sampled to determine endotoxin levels and microbial load. RESULTS: The air in the barn used in this study had a very high concentration of endotoxin (15361.75 ± 7712.16 EU/m(3)). Rats exposed to barn air for one and five days showed increase in AHR compared to the 20-day exposed and controls. Lungs from the exposed groups were inflamed as indicated by recruitment of neutrophils in all three exposed groups and eosinophils and an increase in numbers of airway epithelial goblet cells in 5- and 20-day exposure groups. Rats exposed to the barn air for one day or 20 days had more total leukocytes in the BALF and 20-day exposed rats had more airway epithelial goblet cells compared to the controls and those subjected to 1 and 5 exposures (P < 0.05). Bronchus-associated lymphoid tissue (BALT) in the lungs of rats exposed for 20 days contained germinal centers and mitotic cells suggesting activation. There were no differences in the airway smooth muscle cell volume or septal macrophage recruitment among the groups. CONCLUSION: We conclude that multiple exposures to endotoxin-containing swine barn air induce AHR, increase in mucus-containing airway epithelial cells and lung inflammation. The data also show that prolonged multiple exposures may also induce adaptation in AHR response in the exposed subjects

Infrared spectra and thermal decompositions of metal acetates and dicarboxylates

The infrared spectra of rare earth acetates have been studied to examine the metal-acetate bonding. The thermal decomposition of rare earth acetates as well as lead and copper acetates have been investigated in detail by employing thermogravimetric analysis and differential thermal analysis. Thermal decomposition of calcium dicarboxylates (malonate to sebacate) have been studied employing t.g.a. and d.t.a. Infrared spectra of the dicarboxylates have also been studied. Preliminary results on the products of decomposition of dicarboxylates have been reported

Gravity-driven instability in a spherical Hele-Shaw cell

A pair of concentric spheres separated by a small gap form a spherical Hele-Shaw cell. In this cell an interfacial instability arises when two immiscible fluids flow. We derive the equation of motion for the interface perturbation amplitudes, including both pressure and gravity drivings, using a mode coupling approach. Linear stability analysis shows that mode growth rates depend upon interface perimeter and gravitational force. Mode coupling analysis reveals the formation of fingering structures presenting a tendency toward finger tip-sharpening.Comment: 13 pages, 4 ps figures, RevTex, to appear in Physical Review

A study of knowledge, attitude and practice on use of antibiotics and its resistance among the doctors and interns at urban tertiary care hospital: an interventional study

Background: Infections due to resistant micro-organisms considerably increase the mortality rate, treatment cost, disease spread and duration of illness. The development of antibiotic resistance (AMR) is increasing steadily increasing over the last 10-15 years, which is a real threat to disease management. Many studies states that about 20-50% of antibiotic use unnecessary so decreasing the use of antibiotics is the first step to curb the AMR.Methods: A questionnaire based prospective interventional study among the doctors. Systemic random sampling was applied. The pre tested structured questionnaire was used. Data’s were summarised in the excel sheet, analysed by proportions, percentages and other statistical methods like Student t test, Fisher test and Chi square test were used to check the association. The p>0.05 was considered as significant.Results: Out of 200 doctors, preliminary screening of 170 was included in the study and finally 156 participants were actively selected for analysis of results. Out of 156 participants, 55.1% were MBBS Intern and 44.9% were doctors. High significance (p=0.0001) were found between pre and post knowledge, attitude and practice of doctors.Conclusions: Further modes of studies have to perform to identify the determinants of attitude behaviour and motivation that lead people to use and misuse antibiotics. For effective outcome many more qualitative and quantitative studies are required. In addition, health care system should follow proper regulation and prescription policy as well as controls for prescription of antibiotic drugs