124 research outputs found

    Mathematical simulation of graphene with modified c-c bond length and transfer energy

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    In nanotechnology research, allotropes of carbon like Graphene, Fullerene (Buckyball) and Carbon nanotubes are widely used due to their remarkable properties. Electrical and mechanical properties of those allotropes vary with their molecular geometry. This paper is specially based on modeling and simulation of graphene in order to calculate energy band structure in k space with varying the C-C bond length and C-C transfer energy. Significant changes have been observed in the energy band structure of graphene due to variation in C-C bond length and C-C transfer energy. In particular, this paper focuses over the electronic structure of graphene within the frame work of tight binding approximation. It has been reported that conduction and valence states in graphene only meet at two points in k-space and that dispersion around these special points is conical. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2305

    Experimental Investigation of Land Mobile Prediction Methods and Modeling of Radio Planning Tool Parameters along Indian Rail Road Rural Zones

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    Mobile communication networks in rural zones were not given enough importance and emphasis unlike their urban counter parts due to the unattractive revenues and economic considerations for the cellular operators. In order to identify the suitable prediction methods for Indian rail road rural zones, train-based measurements were conducted in the northern and western rural zones along rail roads. These were carried out by recording the carriers emitted by the trackside base stations inside the moving train. The observed signal levels converted into path losses were compared initially with various conventional prediction methods. The observed results were also compared with the predicted results of radio planning tool utilizing digital terrain data. The constants of the model incorporated in the radio planning tool were tuned separately for north Indian and west Indian base stations based on the observed results. The suitability of the models has been evaluated in terms of standard statistical parameters

    Mathematical simulation of graphene with modified c-c bond length and transfer energy

    Get PDF
    In nanotechnology research, allotropes of carbon like Graphene, Fullerene (Buckyball) and Carbon nanotubes are widely used due to their remarkable properties. Electrical and mechanical properties of those allotropes vary with their molecular geometry. This paper is specially based on modeling and simulation of graphene in order to calculate energy band structure in k space with varying the C-C bond length and C-C transfer energy. Significant changes have been observed in the energy band structure of graphene due to variation in C-C bond length and C-C transfer energy. In particular, this paper focuses over the electronic structure of graphene within the frame work of tight binding approximation. It has been reported that conduction and valence states in graphene only meet at two points in k-space and that dispersion around these special points is conical. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2305

    Interplay of Structural, Optical and Magnetic properties in Gd doped CeO2

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    In this research wok systematic investigation on the synthesis, characterization, optical and magnetic properties of Ce1-xGdxO2 (where x=0.02, 0.04, 0.06, and 0.10) synthesized using the Solid-state method. Structural, Optical and Magnetic properties of the samples were investigated by X-ray diffraction (XRD), UV-VIS-NIR spectroscopy and VSM. Fluorite structure is confirmed from the XRD measurement on Gd doped CeO2 samples. Magnetic studies showed that the Gd doped polycrystalline samples display room temperature ferromagnetism and the ferromagnetic ordering strengthens with the Gd concentration

    Donor site morbidity in oral mucosa graft urethroplasty: implications of tobacco consumption

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    <p>Abstract</p> <p>Background</p> <p>The purpose of this prospective study was to evaluate the donor site morbidity in patients who have undergone oral mucosa graft urethroplasty for stricture of the urethra. The impact of smoking and oral consumption of tobacco and/or <it>paan masala </it>on the donor site was also assessed. This study is probably the first of its kind where the affect of smoking, <it>paan masala </it>and tobacco chewing on the donor site morbidity has been documented.</p> <p>Methods</p> <p>Forty-eight patients suffering from stricture of the urethra underwent oral mucosa graft urethroplasty between July 2005 and December 2007. The patients were divided into two groups (users or non-users) based on tobacco consumption and oral hygiene. The donor site was evaluated at frequent intervals for pain, swelling, numbness, bleeding, salivation and tightness of mouth.</p> <p>Results</p> <p>Donor site morbidity was more in users with poor oral hygiene. Pain scores were higher amongst the users and the morbidity persisted longer in the users compared to non-users with good oral hygiene.</p> <p>Conclusion</p> <p>Patients who consume tobacco and have poor oral hygiene should be warned regarding poorer outcomes after oral mucosa graft urethroplasty.</p

    Peri-operative, functional and early oncologic outcomes of salvage robotic-assisted radical prostatectomy after high-intensity focused ultrasound partial ablation

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    BACKGROUND: Partial ablation of the prostate using high-intensity focussed ultrasound (HIFU-PA) is a treatment option for localised prostate cancer. When local recurrence occurs, salvage robot-assisted radical prostatectomy is a treatment option for selected patients, but there is a paucity of data on the peri-operative safety, functional and oncologic outcomes of sRARP.. The objective of this study was therefore to describe peri-operative safety, functional and early oncologic outcomes following salvage robot-assisted radical prostatectomy (sRARP) for local recurrence after HIFU-PA. METHODS: Retrospective analysis of a prospective database of 53 consecutive men who underwent sRARP after HIFU-PA from 2012 to 2018. Continence and erectile-function were reported pre-HIFU, pre-sRARP, 3-months post-sRARP and 12-months post-sRARP. Complications, PSMs and need for subsequent ADT/radiotherapy were assessed. RESULTS: 45 men were suitable for inclusion and had sufficient data for analyses. Median duration from HIFU to sRARP was 30.0 months and median follow-up post-sRARP was 17.7 months. Median age, PSA and ISUP group were 63.0 yrs., 7.2 ng/mL and 2; 88.9% were cT2. Median operative-console time, blood loss and hospital stay were 140 min, 200 ml and 1 day respectively. Clavien-Dindo grade 1, 2 and 3 complications 90d) complications occurred in 13.2%. At sRARP pathology, ISUP 3-5 occurred in 51.1%, pT3a/b in 64.5%, and PSMs in 44.4% (37.5% for pT2, 48.3% for pT3). Of men with > 3-months follow-up after sRARP, 26.3% underwent adjuvant radiotherapy/ADT for residual disease or adverse pathologic features; 5.3% experienced BCR requiring salvage ADT/radiotherapy. Freedom from ADT/radiotherapy was 66.7% at 12-months. Pad-free rates were 100% pre-HIFU, 95.3% post-HIFU, 29.4% 3-months post-sRARP, and 65.5% 12-months post-sRARP. Median IIEF-5 scores pre-HIFU, post-HIFU, 3- and 12-months post-sRARP were 23.5, 16, 5 and 5, respectively. Potency rates were 81.8, 65.5, 0 and 0%, respectively. Bilateral/unilateral nerve sparing were feasible in 7%/22%. CONCLUSION: Salvage RARP was safe with acceptable but sub-optimal continence and poor sexual-function and poor oncologic outcomes. One in three men required additional treatment within 12-months. This information may aid men and urologists with treatment selection and counselling regarding primary HIFU-PA vs primary RARP and when considering salvage RARP
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