1,715 research outputs found

    Conformal solids and holography

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    We argue that a SO(d)SO(d) magnetic monopole in an asymptotically AdS space-time is dual to a dd-dimensional strongly coupled system in a solid state. In light of this, it would be remiss of us not to dub such a field configuration solidonsolidon. In the presence of mixed boundary conditions, a solidon spontaneously breaks translations (among many other symmetries) and gives rise to Goldstone excitations on the boundary-the phonons of the solid. We derive the quadratic action for the boundary phonons in the probe limit and show that, when the mixed boundary conditions preserve conformal symmetry, the longitudinal and transverse sound speeds are related to each other as expected from effective field theory arguments. We then include backreaction and calculate the free energy of the solidon for a particular choice of mixed boundary conditions, corresponding to a relevant multi-trace deformation of the boundary theory. We find such free energy to be lower than that of thermal AdS. This suggests that our solidon undergoes a solid-to-liquid first order phase transition by melting into a Schwarzschild-AdS black hole as the temperature is raised.Comment: 31 pages; v2: incorrect calculation in sec. 4 has been deleted; main results unchange

    Specific identification, biology and symptoms of whitefly species infesting sunflower in South India

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    Whitefly species related to sunflower was identified as Bemisia tabaci (Gennadius). Further the identified whitefly species was confirmed to be indigenous B. tabaci on molecular basis by using B-biotype specific SCARs and biological silver leaf assay on sensitive pumpkin (cv Big variety). None of the whitefly samples could positive for the presence of B biotype. The results of the study on the pest life cycle under the laboratory conditions showed that, B. tabaci passed through four nymphal instars before the adult stage. The mean duration values of these stages were 5.6, 4.2, 4.4 and 5.6 days respectively. The total duration of the life cycle of B. tabaci ranged from 23- 42 days at the temperature of 29±2°C with a mean of 34.5. The damage to sunflower crop caused by the whitefly species is discussed with a special emphasis on its ability to transmit leaf curl viral disease

    Feasibility of community DOT providers for tuberculosis treatment in HIV infected individuals - A pilot study

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    Background: This paper summarises our experiences about the role of community DOT providers in management of TB treatment in HIV infected persons in a mainly rural population of Tamilnadu. Objectives: To evaluate the feasibility of employing Community DOT providers for the treatment of tuberculosis in HIV infected persons, to study patients’ acceptance of Community DOT providers in the closely-knit village communities and to find out the attitude and awareness of DOT Providers on TB and DOT. Method: A total of 62 tuberculosis patients (58 males and 4 females) with HIV infection attending the Government Hospital for Thoracic Medicine, Tambaram and Chennai between July 1999 and July 2002 were selected for this study. Patients were given all the doses under supervision (clinic-based DOT) during the initial intensive phase and through Community DOT providers in the continuation phase. Data was collected both from the patients and their DOT providers about their views on DOT, advantages of DOTS, drug intake, treatment adherence, problems faced by the patients and their DOT Providers in addition to the level of awareness of Community DOT Providers on tuberculosis and DOTS. Results: Regarding treatment adherence, 95% of 62 patients had taken >75% of drugs and 39% had taken 100% drugs. DOT was appreciated both by the patients and their DOTS Providers since it is cost-effective and patient-friendly. Conclusions: Community contribution to TB care even among HIV infected population is feasible, affordable and costeffective. There is a need for greater health education and training on tuberculosis and DOTS for community DOT Providers

    A review on activated carbon: process, application and prospects

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    Activated carbon (AC) is used in different states of applications after its discovery as a strong and reliable adsorbent. An overview on AC is presented together with revisiting the sources of AC generation; methods used to generate AC comprising of pyrolysis activation; physical activation; chemical activation and steam pyrolysis. The important factors affecting the AC production, the possible applications of AC and their future prospects are also discussed. AC is applied in water, wastewater and leachate treatments in many countries, especially to polish the color, remove the odor and some heavy metals. It is cheap and available, and can be produced from agricultural waste materials, e.g. rice husk, palm oil shell and coconut shell. The AC’s fine and porous structure and an extremely large particle surface area (>1000 m2/g) results in making it possessed powerful adsorptive properties. Therefore, the adsorption process using AC is found to be a potentially viable method of removing pollutants from aqueous solutions

    Development of Cr cold spray–coated fuel cladding with enhanced accident tolerance

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    Accident-tolerant fuels (ATFs) are currently of high interest to researchers in the nuclear industry and in governmental and international organizations. One widely studied accident-tolerant fuel concept is multilayer cladding (also known as coated cladding). This concept is based on a traditional Zr-based alloy (Zircaloy-4, M5, E110, ZIRLO etc.) serving as a substrate. Different protective materials are applied to the substrate surface by various techniques, thus enhancing the accident tolerance of the fuel. This study focuses on the results of testing of Zircaloy-4 coated with pure chromium metal using the cold spray (CS) technique. In comparison with other deposition methods, e.g., Physical vapor deposition (PVD), laser coating, or Chemical vapor deposition techniques (CVD), the CS technique is more cost efficient due to lower energy consumption and high deposition rates, making it more suitable for industry-scale production. The Cr-coated samples were tested at different conditions (500°C steam, 1200°C steam, and Pressurized water reactor (PWR) pressurization test) and were precharacterized and postcharacterized by various techniques, such as scanning electron microscopy, Energy-dispersive X-ray spectroscopy (EDX), or nanoindentation; results are discussed. Results of the steady-state fuel performance simulations using the Bison code predicted the concept's feasibility. It is concluded that CS Cr coating has high potential benefits but requires further optimization and out-of-pile and in-pile testing.United States. Department of Energy (Grant DE-NE0008416

    Pulmonary tuberculosis in HIV individuals: Preliminary report on clinical features and response to treatment

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    Objectives: To study the clinical, radiological and immunological profile of pulmonary tuberculosis in HIV infected patients and assess the response to short-course chemotherapy regimens. Methods: Seventy eight patients (68 males and 10 females) with HIV infection and having symptoms suggestive of tuberculosis attending the Government Hospital for Thoracic Medicine, Tambaram or the Tuberculosis Research Centre, Chennai were studied. The diagnosis of tuberculosis was based on clinical evaluation, bacteriological examination including sputum smear and culture and chest skiagram. HIV diagnosis was based on two tests (rapid/ELISA), detecting different antigens. CD4+ T cell counts were done on all patients initially and at the end of treatment. Blood tests and skiagrams were repeated at 2 months and at the end of treatment. All the patients were treated with standard (RNTCP) short course regimens. Patients were given all the doses under supervision during the initial intensive phase and through community DOTS providers in the continuation phase. Results: Sixty five patients had culture confirmed pulmonary tuberculosis, of whom 54 had smear positive disease, initially. The radiological manifestations were varied, with 11 subjects having miliary tuberculosis, 54 with non-homogeneous opacities and 10 with cavitation. The mean CD4 cell count at intake was 192 ± 172 cells/cumm. Patients showed good initial response to treatment with significant weight gain. At the end of 2 months of treatment, 91% of patients had sputum cultures negative for Mycobacterium tuberculosis. However, the CD4 % fell significantly by the sixth month. The study is being continued to assess the long-term response to SCC of patients with HIV and tuberculosis. Conclusions: Tuberculosis has a varied clinical presentation in patients with HIV infection. The spectrum of radiographic features ranges from normal to a miliary pattern. Inspite of clinical and bacteriological improvement during treatment, immunologic deterioration may continue

    To Study the Etiopathogenesis, Clinical Presentation and Management of Patients with Colorectal Emergencies Presenting as Acute Abdomen

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    BACKGROUND: Malignancies are most leading cause of mortality in this era, colorectal malignancies are third common cause of death due to cancers, about 60% of patient have malignant growth causing lower GI obstruction (followed by volvulus 35%) and their high mortality rate atributed to late presentation. OBJECTIVE: In this article the commenest etiology, presentation and commonest procedure performed in emergency in our institution are compared with existing articles and previous study. STUDY DESIGN: Observational study a prospective and retrospective study. STUDY POPLATION: about 50 patients admitted in emergency department Rajiv Gandhi Govt. General Hospital are studied . STUDY DURATION: Datas of 8 months studied in six months April 2016 to September2016. MATERIALS AND METHODIOLOGY: Patients are subjected to detailed history taking and clinical examination. Data are collected through medical records in case of retrospective analysis. Patients presented with acute abdomen in emergency ward in general surgery department satisfying the inclusion and exclusion criteria are taken into study. Detailed history and clinical examination is done. Baseline investigations and preoperative imaging (x-ray, ultrasonogram, contrast CT) are done and pathology is localized to colorectal region. Findings during the emergency laparotomy is recorded. The disease region and performance status of the patient is noted. The etiopathogensis of the colorectal emergency leading on to acute abdomen is noted. The patients are followed up post operatively. The various parameters affecting recovery of the patient and the nature of disease and its severity and its outcome are studied. The appropriate procedure favoring to prognosis of the patient in emergencies is studied. The post operative morbidity and mortality of the patients undergoing the emergency procedure is recorded. The age group of patients, their clinical presentation and etiopathogenesis in different age group causing obstruction, perforation and peritonitis necessitating the need for emergency laparotomy are also studied. The decision regarding performing primary procedure in emergency as a life saving procedure is also analyzed. RESULTS: About 50 patients are studied with maximum number of patients were older age group presented with obstruction and cause is due to colonic growth and most commonly involved region is recto sigmoid region, the mortality is more in this segment of bowel. Despite of advanced mode of diagnosis andsurgical techniques the death rate is high due to change in biology and emerging mutations making disease very aggressive ,nutritionally improved patient got rapid recovery. Secondly sigmoid volvulus is competeing with colonic malignancies leads to second most common cause of morbidity and mortality in that region. CONCLUSION: Adequate preparation preoperatively with hydration, electrolytes and nutrition early appropriate surgical procedure will have reduced mortality in emergencies. Early presentation to hospital after getting symptoms of disease will avoid deaths among people
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