Optimization of Interfacial Interactions to Achieve the Nanoscale Dispersion of Clay in Polymer/Clay Nanocomposites

Polymer clay nanocomposites are a promising class of multicomponent systems where incorporation of small amount of clay results in dramatic improvement of mechanical, thermal and barrier properties. However, accomplishment of these properties necessitates molecular level dispersion of the clay platelets in the polymer matrix. This thesis presents the guidelines for obtaining thermodynamically stable nanocomposites where strong specific interactions such as hydrogen bonding between the polymer and the clay can be utilized to achieve the desired goal of nanoscale dispersion of clay sheets. In first part of the dissertation, optimization of intermolecular hydrogen bonding between the polymer and clay is carried out by controlling the distribution of hydroxyl groups on the copolymer of styrene and 4-vinyl phenol. Copolymers ranging from 0- 100% vinyl phenol are synthesized by free radical polymerization. Nanocomposites containing 50 % poly(vinyl phenol) and 40 % poly(vinyl phenol) show optimum dispersion due to large extent of intermolecular hydrogen bonding with drastic improvement in glass transition temperature. Furthermore, the effect of the nature of clay surfactant on the dispersion of clay sheets in the polymer matrix is also studied. Nanomer I.24 TL and Cloisite 25A show similar trends in dispersion for all the copolymer compositions. Increase in vinyl phenol content from 0-50% enhances the dispersion of clay platelets. However, Nanomer I.24 TL and Cloisite 25A show different morphological behavior than Cloisite Na+ towards the polymer containing 100% vinyl phenol. This behavior arises due to the fact that hydrophobic surfactants of Nanomer I.24 TL and Cloisite 25A do not find themselves very compatible with hydrophilic polymer, poly(vinyl phenol) thus giving rise to intercalated morphology in opposition to exfoliation observed for Cloisite Na+ nanocomposite with the same polymer. Cloisite Na+ is highly hydrophilic and therefore very miscible with 100% vinyl phenol, consequently a nanocomposite with improved dispersion is obtained. Next, clay loading is also optimized in the nanocomposites to obtain the best morphological and thermal improvements. Clay loadings of 1, 3, 5 and 8 wt % are mixed with copolymers ranging from 0-100 % vinyl phenol. 3 and 5 % clay loadings with PVPh40 and PVPh50 nanocomposites exhibit optimum dispersion of clay platelets with drastic improvement in glass transition temperature

A New Palm Print Recognition Approach by Using PCA & Gabor Filter

The key problems that involve in identification of palm print are searching for the better match from the test sample taken from input and also the available templates in the palm print database. The selection of the features and measuring similarity are 2 basic to be resolved. A feature that has higher discriminating ability should need to show a large variation between samples taken from totally different persons and small variation between samples taken from the palm of same person. Principal lines with information points are consider as very helpful palm print features and are successfully used for the aim of verification. Excluding these features there are many various features present in a palm print like: wrinkle features, geometry features, minutiae features and delta point features. It�s noted that each one of those features of palm are involved with the native attributes supported points or line segments. 2 key points in palm print identification are: first is to develop an efficient algorithm that extracts helpful features and second is to correctly measure the similarity of 2 features sets. In contrast to the existing technique, propose a combine selection technique for identification by using the palm print feature base pattern matching by combining native and global palm print features in some stratified fashion. In this work, use PCA, Gabor Filter and KNN for the aim of classification and matching. This work show palm print authentication system operates in 2 ways in which first is enrolment and the second is verification. In enrolment, a user needs to offer palm print samples many times to the system. The samples is captured with the use of any image capturing device that then pre-processed and so extraction of features is done to provide the templates that keep template database. For verification user is instruct to produce his/her user ID and palm print sample, then the palm print sample are pre-processed and extraction of feature is done to compared it with templates keep within the database that belonging to constant user ID

Hypocellular acute myeloid leukemia with bone marrow necrosis in young patients: two case reports

<p>Abstract</p> <p>Introduction</p> <p>Hypocellular variants of acute myeloid leukemia are very rare and almost always occur in old aged patients. In contrast, hypocellular acute lymphoblastic leukemia usually occurs in children.</p> <p>Case presentation</p> <p>We report two Indian patients with hypocellular acute myeloid leukemia, a 32-year-old woman and a 13-year-old boy. Interestingly, one of the patients also showed bone marrow necrosis.</p> <p>Conclusion</p> <p>Hypocellular acute myeloid leukemia is a rare entity and can affect young individuals. It can be considered as a rare cause of bone marrow necrosis.</p

A study of the clinical profile of 50 patients of COPD with correlation between clinical, radiological and spirometric evaluation

Background: Chronic obstructive pulmonary disease (COPD) is a common, preventable and treatable disease that is characterised by persistent respiratory symptoms and airflow limitation that is due to airway and/ or alveolar abnormalities usually caused by significant exposure to noxious particles or gases. Tobacco smoking, occupational exposure to organic and inorganic dusts, chemical agents and fumes and biomass cooking are the risk factors for COPD. Chronic dyspnoea, cough, sputum production, wheezing and chest tightness are the common symptoms of COPD. The present study was undertaken to evaluate the clinical, radiological and spirometric parameters in patients with COPD and to demonstrate a correlation between them.Methods: This was a prospective study of 50 patients of COPD who presented to out- patient department. We included all patients above 40 years of age with a smoking index of 200 or more, or history of exposure to occupational dust, biomass fuel gas or exposure to other obnoxious gases; and who had history of dyspnoea and cough. Spirometry was performed to confirm the diagnosis and to grade the severity of airflow obstruction. History of dyspnoea, cough, sputum production, wheezing, chest tightness, fever, weight loss and the number of exacerbations in the previous year was noted. We then performed a detailed clinical examination. Blood was sent for haemogram and arterial blood gas analysis and all patients underwent an ECG, 2- D Echo and HRCT of the thorax. We then studied the correlation between the clinical, radiological and spirometric profiles in these patients.Results: Out of the 50 patients, majority was between 50-59 years of age, with male to female ratio of 1.94:1.00. History of smoking was present in 74% patients, exposure to biomass fuel in 12% and exposure to occupational dust in 6% patients. Commonest symptom was dyspnoea (in 100% patients) followed by cough (88%), sputum production (68%), wheezing (58%), chest tightness and fever (30%) and weight loss (28%). HRCT was positive in 75% patients, while ECG changes were seen in 42% patients and pulmonary hypertension was present in 54% patients. A significant association was observed between grade 5 dyspnoea on mMRC, hypoxia, hypercarbia, pulmonary hypertension and Gold-5 airflow obstruction.Conclusions: In the present study of 50 cases, COPD was seen predominantly in male patients, with a mean age of presentation between 50- 59 years. Tobacco smoking was the commonest etiological factor. Clinical symptoms most commonly documented were dyspnoea, cough with or without expectoration, wheezing, chest tightness, fever and weight loss. A significant association was observed between grade 5 dyspnoea on mMRC, hypoxia, hypercarbia, pulmonary hypertension and Gold-5 airflow obstruction

Computational fluid dynamics (CFD) modelling of hybrid photovoltaic thermal system

In this paper an attempt has been made to simulate and evaluate the distribution of temperature and heat flux for the hybrid photovoltaic thermal system with CFD (computational fluid dynamics) module in ANSYS 19.1 software. The simulation was carried to determine the temperature and heat flux across the different layers of HPVT (hybrid photovoltaic thermal) system. The temperature and heat flux were found to gradually decrease from the top glass layer to the bottom tedlar layer. The temperature varied from 36.4 °C (ambient) to 26.8 °C across the layers from top glass layer to bottom tedlar layer. The heat flux of (561.2 W/m2) at the glass layer due to solar insolation was also found to gradually decrease with the increasing thickness. The reduction in temperature and heat flux with increasing thickness is attributed to fluid flowing beneath the system. The water flowing beneath the tedlar layer takes the excess heat out of the photovoltaic layer, thereby increasing the efficiency of the hybrid photovoltaic thermal system

Melanotic medullary carcinoma of thyroid – report of a rare case with brief review of literature

<p>Abstract</p> <p>Background</p> <p>Melanin production in medullary carcinoma is extremely uncommon.</p> <p>Case presentation</p> <p>We report a rare variant of medullary carcinoma of thyroid with melanin production in a 52-year-old woman who presented with swelling in the thyroid of 3 months duration. This tumor recurred thrice in two years after surgery and patient died with metastasis. Microscopic examination showed typical morphology of medullary carcinoma with numerous cells loaded with melanin pigment as confirmed by bleached Fontana-Masson, negative iron and immunohistochemical stains. Tumor cells were diffusely immunopositive for calcitonin, HMB-45, chromogranin, synaptophysin, CEA but showed focal paranuclear dot positivity for cytokeratin. No C-cell hyperplasia was seen in the adjacent thyroid gland. Nature of the pigment was further confirmed on ultra structural examination.</p> <p>Conclusion</p> <p>Melanotic medullary carcinoma is an extremely uncommon entity. There is a need to report more number of cases in the literature for exact categorization and prognostication of this subtype of medullary carcinoma.</p

Metrics and Heuristics in Software Engineering

Heuristics plays an important role in software development and are widely used to provide a link between design principles and software measurement. They offer insightful information based upon experience that is known to work in practice. Heuristics are not meant to be exact; in fact, they derive their benefits from this imprecision by providing an informal guide to good and bad practices. They provide a means by which knowledge and experience can be delivered from the expert to the novice. The paper is set out to bring techniques for building maintainable object oriented software closer to the developer in the form of design heuristics. Heuristics document common design problems that developers encounter during software development. Some heuristics in software engineering can be expressed in high-level abstract terms while others are more specific. The heuristic catalogue provides a comprehensive reference point for both novice and expert developers to apply well-documented techniques for building maintainable software

Metastatic malignant melanoma in bone marrow with occult primary site – a case report with review of literature

<p>Abstract</p> <p>Background</p> <p>Metastases of malignant melanoma to the bone marrow are very rare. A few case reports are published in the literature with a known primary site.</p> <p>Case presentation</p> <p>Herein we present a case of metastatic malignant melanoma in bone marrow with occult primary site in a 22- year-old-male. Diagnosis was confirmed by morphology and immunohistochemistry. A pertinent review of literature is also presented by using relevant articles indexed in PubMed (National Library of Medicine) database. The search was based on the following terms: metastasis or metastases, malignant melanoma and bone marrow.</p> <p>Conclusion</p> <p>In this report we discuss a rare case of metastatic malignant melanoma to the bone marrow with an unknown primary. Clinicians must be aware of the varied clinical manifestations of disseminated malignant melanoma even if the primary site is not evident.</p