13 research outputs found

    High yield synthesis of electrolyte heating assisted electrochemically exfoliated graphene for electromagnetic interference shielding applications

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    Herein, we demonstrate a facile one pot synthesis of graphene nanosheets by electrochemical exfoliation of graphite. In the present study, we report a significant increase in the yield of graphene by electrolyte heating assisted electrochemical exfoliation method. The obtained results of heating assisted electrochemically exfoliated graphene (utilizing H2SO4 + KOH + DW) synthesis clearly exhibit that the yield increases similar to 4.5 times i.e. from similar to 17% (room temperature) to similar to 77% (at 80 degrees C). A plausible mechanism for the enhanced yield based on lattice expansion and vibration of intercalated ions has been put forward and discussed in details. The quality of graphene was examined by Raman, XPS, FTIR, AFM, SEM, TEM/HRTEM and TGA techniques. The Raman as well as morphogenesis results confirm the quality of the graphene nanosheets. We have used this graphene as electromagnetic interference shielding material where a comparatively large quantity of graphene is required. This graphene exhibits enhanced shielding effectiveness (46 dB at 1 mm thickness of stacked graphene sheets in frequency region 12.4 to 18 GHz) as compared to conventional electromagnetic interference shielding materials, which is greater than the recommended limit (similar to 30 dB) for techno-commercial applications. Thus the present work is suggestive for future studies on enhancement of yield of high quality graphene by proposed method and the use of synthesized graphene in electromagnetic interference shielding and other possible applications

    Magnetic properties of undoped YBa 2 Cu 3 O 6 + x system

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    75.30.-m Intrinsic properties of magnetically ordered materials, 74.72.Bk Y-based cuprates, 75.10.Jm Quantized spin models,

    Prevalence and Association of Mycobacterium avium subspecies paratuberculosis with Disease Course in Patients with Ulcero-Constrictive Ileocolonic Disease.

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    Association of Mycobacterium avium subspecies paratuberculosis (MAP) and Crohn's disease (CD) has been controversial due to contradictory reports. Therefore, we determined the prevalence of MAP in patients with CD and intestinal tuberculosis (ITB) and its association with clinical course.Blood and intestinal biopsies were taken from 69 CD, 32 ITB patients and 41 patients with haemorrhoidal bleed who served as controls. qPCR targeting of MAP-specific IS900 gene was used to detect the presence of MAP DNA. qPCR results were further validated by sequencing. Immunohistochemistry (IHC) was used to detect the presence of MAP antigen in biopsy specimens. CD and ITB patients were followed-up for disease course and response to therapy.The frequency of MAP-specific DNA in biopsies by qPCR was significantly higher in CD patients (23.2%, p = 0.03) as compared to controls (7.3%). No significant difference in intestinal MAP presence was observed between ITB patients (12.5%, p = 0.6) and controls (7.3%). MAP presence in blood of CD patients was 10.1% as compared to 4.9% in controls while no patients with ITB were found to be positive (p = 0.1). Using IHC for detection of MAP antigen, the prevalence of MAP in CD was 2.9%, 12.5% in ITB patients and 2.4% in controls. However, long-term follow-up of the patients revealed no significant associations between clinical characteristics and treatment outcomes with MAP positivity.We report significantly high prevalence of MAP in intestinal biopsies of CD patients. However, the presence of MAP does not affect the disease course and treatment outcomes in either CD or ITB patients
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