772 research outputs found
Magnetothermoelectric transport in modulated and unmodulated graphene
We draw motivation from recent experimental studies and present a
comprehensive study of magnetothermoelectric transport in a graphene monolayer
within the linear response regime. We employ the modified Kubo formalism
developed for thermal transport in a magnetic field. Thermopower as well as
thermal conductivity as a function of the gate voltage of a graphene monolayer
in the presence of a magnetic field perpendicular to the graphene plane is
determined for low magnetic fields (~1 Tesla) as well as high fields (~8
Tesla). We include the effects of screened charged impurities on thermal
transport. We find good, qualitative as well as quantitative, agreement with
recent experimental work on the subject. In addition, in order to analyze the
effects of modulation, which can be induced by various means, on the thermal
transport in graphene, we evaluate the thermal transport coefficients for a
graphene monolayer subjected to a periodic electric modulation in a magnetic
field. The results are presented as a function of the magnetic field and the
gate voltage.Comment: 14 pages, 8 figure
Superconductivity in Pseudo-Binary Silicide SrNixSi2-x with AlB2-Type Structure
We demonstrate the emergence of superconductivity in pseudo-binary silicide
SrNixSi2-x. The compound exhibits a structural phase transition from the cubic
SrSi2-type structure (P4132) to the hexagonal AlB2-type structure (P6/mmm) upon
substituting Ni for Si at approximately x = 0.1. The hexagonal structure is
stabilized in the range of 0.1 < x < 0.7. The superconducting phase appears in
the vicinity of the structural phase boundary. Ni acts as a nonmagnetic dopant,
as confirmed by the Pauli paramagnetic behavior.Comment: 12 pages, 5 figure
Seroprevalence of leptospiral antibodies among market workers and food handlers in the central state of Malaysia
Objective:The high prevalence of leptospirosis in humans is of great public health concern, particularly in tropical and subtropical regions. This study aimed to determine the seroprevalence of leptospiral antibodies and distribution of serovars, and to assess the usefulness of enzyme-linked immunosorbent assay (ELISA) as a screening method for leptospiral antibodies in a high-risk healthy community. Methods: Cross-sectional study of 231 market workers and food handlers in wet markets and food premises from two localities in central Malaysia. Respondents' background information was obtained using a questionnaire. Serum samples were tested for leptospiral antibodies using ELISA and microscopic agglutination test (MAT). Results: Seroprevalence of leptospirosis among healthy workers was 46.3%. Detection of seropositivity was higher by MAT (46%) than ELISA (15%). We observed high seropositivity among local workers (49%), food handlers (49.5%), females (60.8%) and those aged 34 years and older (46.3%). Local strain LEP175 was the predominant serovar, followed by WHO strain Patoc. Conclusion: Overall seroprevalence among healthy food handlers and market workers was high in this study. The workplace places susceptible individuals at risk of leptospirosis
Oral cancer and precancer research in Malaysia - the database and tissue resource bank
Introduction: Uncoordinated data collection by different research groups prompted the initiation of Malaysian oral cancer Research Initiative (MOCRI) group. Objectives: To coordinate and standardize data and tissue collection and storage, develop a minimum dataset on risk factors, intervention techniques and quality of life of oral cancer patients. Materials and Methods: A computer software programme is currently being developed to accommodate multi-centre data collection and research activities in eight hospitals. The complete dataset includes parameters on sociodemographic, clinical, pathological, quality of life measures, details of treatment methods, vital status and dietary intake. Tissues are being collected, stored and catalogued as fresh and formalin-fixed tissues for future use in satellite researches. The networking in tissue and data collection includes the establishment of oral cancer cell-lines. These tissues are being planned for studies on genetic profile, genetic polymorphism, diagnostic and prognostic markers. Results: Tissues and data on 115 oral cancers, 9 leukoplakia and 13 lichen planus has been collected since 2003. Preliminary data from 2004 were analysed for 58 cancer patients. Majority of them are more than 60 years old (65.5%) with a mean age of 63.3. Twenty-four (41.4%) were males, 34 (58.6%) females with the majority of them being Indians (56.9%) followed by Chinese and Malays (15.5% each), Indigenous people of Sabah and Sarawak (12.1%). Eighteen (31%) respondents were smokers, 17 (29.3%) alcohol drinkers and 31 (53.4%) betel quid chewers. Five patients have had histories of family cancers where 3 included immediate family members with head and neck cancers. For the quality of life measure, only 30.2% felt that their daily activities were disrupted despite having advanced cancers. Satellite researches are in progress on genetic polymorphism and tumour markers. One oral cancer cell-line has been established. Conclusion: The establishment of oral cancer database and tissue bank in encouraging and supports on-going satellite researches. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down
Electromagnetic Interference (EMI) Analysis on Surface Roughness of 3C-Silicon Carbide (3C-SiC) Deposited on Silicon (Si) Substrate
Electronic devices may produce undesirable electromagnetic (EM) interference which can degrade the system performance and also affect human health. In this paper, the potential property of 3C-Silicon Carbide (3C-SiC) as the microwave absorbing material is investigated. The reflection coefficient, Г of 3C-SiC has been measured using an open-ended coaxial sensor. The substrates consisted of films of 3C-SiC of two different thicknesses (0.265µm and 0.285µm) with both polished and unpolished surfaces. The measurements were taken in the frequency range within 1.4 GHz to 18.8 GHz at room temperature. A continuous decrease in the reflection coefficient was measured in 3C-SiC as the frequency increased to 18.8GHz. The results have shown that the rougher surface of unpolished 3C-SiC of 0.285µm thickness could be applied as microwave absorbing material
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