1,718 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

    Impact of HIV Infection on Radiographic Features in Patients with Pulmonary Tuberculosis

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    Background. There is insufficient data on the radiographic presentation of tuberculosis in human immunodeficiency virus (HIV) infected patients from India. Methods. We examined the chest radiographs of 181 patients including 82 HIV positives with newly diagnosed sputum culture positive pulmonary tuberculosis before and after the completion of anti-tuberculosis treatment (ATT). Patients with smear/culture positive pulmonary tuberculosis were treated with Revised National Tuberculosis Control Programme (RNTCP) Cat-I regimen (2EHRZ3/4HR3). An independent assessor blinded to HIV and clinical status of patients read the radiographs. Results. At presentation, HIV seropositive patients were significantly more likely to have normal chest radiographs (14.2% vs 0), miliary tuberculosis (10.7% vs 1%) and pleural effusion (16.6% vs 3%), and less likely to have cavitation (17.8% vs 39.4%) as compared to HIV negative patients. At the end of treatment, HIV positive patients were more likely to have normal radiographs (42.8% vs 1.2%), and less likely to have fibrosis (17.8% vs 42.5%). Conclusions. The radiographic presentation of pulmonary tuberculosis in HIV-infected patients is atypical with less cavitation, and more dissemination. On completion of ATT, patients with HIV have less radiographic sequelae in the form of fibrosis. These features may be due to the reduced inflammatory response that patients with HIV infection may be able to mount
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