229 research outputs found

    Effect of Thermal and Microwave Treatment on Low Temperature Mechanical Property of Glass Fiber Reinforced Polymer Composite: An Experimental Exploration

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    There has been a tremendous advancement in the science and technology of fiber reinforced polymer composites (FRP) in recent times. The low density, high strength, high stiffness to weight ratio, excellent durability, and design flexibility of fiber reinforced polymers are the primary reasons for their use in many structural components in the aircrafts, automotive, marine, transportation, sports, medical science and more recently the building and construction industries and particularly in areas that are weight and corrosion sensitive. A recent example is the Bridge-in-a-Backpack for 2014 Winter Olympics in Russia, an innovative inflatable composite-concrete arch bridge, which was developed to reduce construction time and costs, increase lifespan, reduce maintenance costs and reduce the carbon footprint of bridge construction1. But the phenomenon of the occurrence of their fracture and failure at low temperatures and under varying loading rates is a quite complex, and is not easily understandable phenomenon, because of the various types of the failure modes involved (e.g. delamination sites, debonding, fiber pullout regions, crack propagation front, striations and bubble bursting in the matrix). Thus a critical study has to be made to understand the overall phenomenon. Recently an active area of investigation related to this work is being explored by Temperature Modulated Differential Scanning Calorimetry (TMDSC) and Fourier Transform Infrared Spectroscopy (FTIR-Imaging), techniques to find out the possible causes for failure of the composite. In the present study, an attempt has been made for fractographic study of the composite material using SEM micrographs of the fractured surfaces of composites under Thermally Conditioned and post curing by Microwave treatment, followed by their exposure in ultralow temperatures, so that the origin of the crack could be analyzed and the factors affecting the locus of initiation of fracture could be determined. This would be followed by FTIR-Imaging and TMDSC to determine the alternation and deviation of Stoichiometry and the Tg values respectively, to have a better idea about the failure phenomenon

    TREND ANALYSIS OF RAINFALL, TEMPERATURE AND RUNOFF DATA: A CASE STUDY OF RANGOON WATERSHED IN NEPAL

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    Purpose: The study has been carried out to investigate and assess the significance of the potential trend of three variables viz. rainfall, temperature and runoff over the Rangoon watershed in Dadeldhura district of Nepal.Methodology: In this study, trend analysis has been carried out on monthly, seasonal and annual basis using the data period between 1979 to 2010 for rainfall and temperature and 1967 to 1996 for runoff. Mann-Kendall test and Sen’s slope estimate test were applied to identify the existing trend direction and Sen’s slope estimator test were used to detect the trend direction and magnitude of change over time.Main findings: The most important findings are, i) There is warming trends over the Rangoon watershed as Mann-Kendall statistic (Z-value) for most of the maximum temperature values are positive, ii) Rainfall and runoff affected by fluctuations every year though the annual rainfall showing a rising trend whereas runoff showing a falling trend. The rainfall seasonal trend analysis indicates that monsoon and post-monsoon period showed a positive rainfall trend with z statistics of +1.93, and +1.12 respectively, whereas pre-monsoon and winter seasons showed a negative trend with z statistics of -1.02, and -0.54 respectively. However, the annual rainfall in the Rangoon watershed showed a positive trend with a z value of +1.70.Importance of this study: This case study has been undertaken to investigate the trends of important climatic variables viz. rainfall, temperature which have a direct impact on the agriculture of the region.Originality / Novelty of study: This is an original research work undertaken under the M. Tech programme during 2016-17 at IIT Roorkee by the scholar Er. Amar Bahadur Pal from Nepal.

    Chicken pox infection in patients undergoing chemotherapy: A retrospective analysis from a tertiary care center in India

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    SummaryThere is paucity of data on the incidence, severity and management of chicken pox in patients receiving active chemotherapy for cancer.From October 2010 to October 2011, patients were included in this study if they developed a chicken pox infection during their chemotherapy. The details of patients’ cancer diagnosis and treatment along with clinical and epidemiological data of the chicken pox infections were assessed from a prospectively maintained database.Twenty-four patients had a chicken pox infection while receiving chemotherapy and/or radiotherapy. The median age of the patients was 21 years, and two-thirds of the patients had solid tumor malignancies.Overall, eight (33%) patients had complications, six (25%) patients had febrile neutropenia, four (17%) had diarrhea/mucositis, and four (17%) had pneumonia. The median time for recovery of the infection and complications in the patients was 9.5 days (5–29 days), whereas for neutropenic patients, it was 6.5 days (3–14 days). The median time for recovery from chicken pox infections in neutropenic patients was 10 days (5–21 days), compared with 8.5 days (0–29 days) in non-neutropenic patients (P=0.84). The median time for recovery from infections was 8.5 days in patients with comorbidities (N=4), which was the same for patients with no comorbidities.The clinical presentation and complication rates of chicken pox in cancer patients, who were on active chemotherapy, are similar to the normal population. The recovery from a varicella infection and complications may be delayed in patients with neutropenia. The varicella infection causes a therapy delay in 70% of patients. Aggressive antiviral therapy, supportive care and isolation of the index cases remain the backbone of treatment

    Sensitive detection of Nitrogen Dioxide using gold nanoparticles decorated Single Walled Carbon Nanotubes

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    The modification of carbon nanotubes (CNTs) could enhance their surface and electric properties. To this purpose, we explore the impact of a thin layer of gold (Au) on the surface of single wall carbon nanotubes (SWCNTs). SWCNTs have been grown by Chemical Vapor Deposition (CVD) method and decorated with gold nanoparticles were investigated as gas sensitive materials for detecting nitrogen dioxide (NO2) at room temperature. Surface morphology and microstructure of Au-SWCNT have been characterized by FE-SEM and Raman Spectroscopy. Using the present collective approaches, the improvement in the detection of NO2 gas using Au-modified nanotubes is explained. However, Au-modified SWCNT gas sensors exhibited better performances compared to pristine SWCNTs. These changes in resistance and the shift of the Fermi level just after NO2 exposure was probably due to adsorption of NO2 molecules on the surface of Au-SWCNTs. Surface modification of nanotubes with understanding of sensing ability at atomic level opens the new way to design a selectivity gas sensor

    Neoadjuvant chemotherapy or chemoradiotherapy in head and neck cancer

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    The multidisciplinary approach to treating squamous cell carcinoma of the head and neck is complex and evolving. Chemotherapy is increasingly being incorporated into the treatment of squamous cell carcinoma of the head and neck. Previously, radiotherapy following surgery was the standard approach to the treatment of loco regionally advanced resectable disease. Data from randomized trials have confirmed the benefits of concurrent chemo radiotherapy in the adjuvant setting. Chemo radiotherapy is also the recommended approach for unresectable disease. Advanced loco regional disease is the most frequent clinical situation in Head and Neck cancer. The standard of care for most clinicians is a multidisciplinary treatment with concomitant chemotherapy plus radiotherapy (CRT). However, retrospective studies have shown that in patients treated with CRT there was a relative increase in systemic relapse due to a lack of systemic control. For this reason a renewed interest has appeared for the incorporation of induction chemotherapy in the treatment of locally advanced Head and Neck Cancer. Furthermore new combination regimens with taxanes have shown to be more active than the classical cisplatin and 5-fluorouracil induction regimen. Novel targeted agents, such as epidermal growth factor receptor antagonists, are showing promise in the treatment of patients with both loco regionally advanced and recurrent/metastatic squamous cell carcinoma of the head and neck

    Metronomic adjuvant chemotherapy evaluation in locally advanced head and neck cancers post radical chemoradiation – a randomised trial

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    Background: Locally advanced head and neck cancers treated with radical chemoradiation have unsatisfactory outcomes. Oral metronomic chemotherapy improves outcomes in comparison to maximum tolerated dose chemotherapy in the palliative setting. Limited evidence suggests that it may do so in an adjuvant setting. Hence this randomized study was conducted. Methods: Patients of head and neck (HN) cancer with primary in oropharynx, larynx or hypopharynx, with PS 0–2 post radical chemoradiation with documented complete response were randomized 1:1 to either observation or oral metronomic adjuvant chemotherapy (MAC) for 18 months. MAC consisted of weekly oral methotrexate (15 mg/m2) and celecoxib (200 mg PO BD). The primary endpoint was OS and the overall sample size was 1038. The study had 3 planned interim analyses for efficacy and futility. Trial registration- Clinical Trials Registry- India (CTRI): CTRI/2016/09/007315 [Registered on: 28/09/2016] Trial Registered Prospectively. Findings: 137 patients were recruited and an interim analysis was done. The 3 year PFS was 68.7% (95% CI 55.1–79.0) versus 60.8% (95% CI 47.9–71.4) in the observation and metronomic arm respectively (P value = 0.230). The hazard ratio was 1.42 (95% CI 0.80–2.51; P value = 0.231). The 3 year OS was 79.4% (95% CI 66.3–87.9) versus 62.4% (95% CI 49.5–72.8) in the observation and metronomic arm respectively (P value = 0.047). The hazard ratio was 1.83 (95% CI 1.0–3.36; P value = 0.051). Interpretation: In this phase 3 randomized study, oral metronomic combinations of weekly methotrexate and daily celecoxib failed to improve the PFS or OS. Hence observation post-complete response post radical chemoradiation remains the standard of care. Funding: ICON funded this study.</p

    Neoadjuvant chemotherapy or chemoradiotherapy in head and neck cancer

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    The multidisciplinary approach to treating squamous cell carcinoma of the head and neck is complex and evolving. Chemotherapy is increasingly being incorporated into the treatment of squamous cell carcinoma of the head and neck. Previously, radiotherapy following surgery was the standard approach to the treatment of loco regionally advanced resectable disease. Data from randomized trials have confirmed the benefits of concurrent chemo radiotherapy in the adjuvant setting. Chemo radiotherapy is also the recommended approach for unresectable disease. Advanced loco regional disease is the most frequent clinical situation in Head and Neck cancer. The standard of care for most clinicians is a multidisciplinary treatment with concomitant chemotherapy plus radiotherapy (CRT). However, retrospective studies have shown that in patients treated with CRT there was a relative increase in systemic relapse due to a lack of systemic control. For this reason a renewed interest has appeared for the incorporation of induction chemotherapy in the treatment of locally advanced Head and Neck Cancer. Furthermore new combination regimens with taxanes have shown to be more active than the classical cisplatin and 5-fluorouracil induction regimen. Novel targeted agents, such as epidermal growth factor receptor antagonists, are showing promise in the treatment of patients with both loco regionally advanced and recurrent/metastatic squamous cell carcinoma of the head and neck
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