A review on potentiality of nano filler/natural fiber filled polymer hybrid composites

The increasing demand for greener and biodegradable materials leading to the satisfaction of society requires a compelling towards the advancement of nano-materials science. The polymeric matrix materials with suitable and proper filler, better filler/matrix interaction together with advanced and new methods or approaches are able to develop polymeric composites which shows great prospective applications in constructions and buildings, automotive, aerospace and packaging industries. The biodegradability of the natural fibers is considered as the most important and interesting aspects of their utilization in polymeric materials. Nanocomposite shows considerable applications in different fields because of larger surface area, and greater aspect ratio, with fascinating properties. Being environmentally friendly, applications of nanocomposites offer new technology and business opportunities for several sectors, such as aerospace, automotive, electronics, and biotechnology industries. Hybrid bio-based composites that exploit the synergy between natural fibers in a nano-reinforced bio-based polymer can lead to improved properties along with maintaining environmental appeal. This review article intended to present information about diverse classes of natural fibers, nanofiller, cellulosic fiber based composite, nanocomposite, and natural fiber/nanofiller-based hybrid composite with specific concern to their applications. It will also provide summary of the emerging new aspects of nanotechnology for development of hybrid composites for the sustainable and greener environment

Malignant melanoma metastatic to the thyroid gland: a case report and review of the literature.

The thyroid gland is a relatively uncommon site for a secondary malignancy; even less common is a case of malignant melanoma metastatic to the thyroid. We describe the case of a 68-year-old man who presented with a neck mass in the posterior triangle. Fine-needle aspiration biopsy (FNAB) identified the mass as a malignant melanoma. The patient had had no known primary skin melanoma. He underwent a left modified radical neck dissection, and the mass was discovered to be a positive lymph node. Postoperatively, he declined to undergo radio- and chemotherapy. Eighteen months later, he returned with a diffusely enlarged thyroid. FNAB again attributed the enlargement to malignant melanoma. Soon thereafter, the patient began experiencing seizures, and on magnetic resonance imaging, he was found to have metastatic disease to the brain. He developed ventilator-dependent respiratory failure and required a subtotal thyroidectomy for the placement of a tracheostomy tube. Patients who present with a thyroid nodule and who have a history of malignancy present a diagnostic dilemma: Is the nodule benign, a new primary, or a distant metastasis? The findings of this case and a review of the literature strengthen the argument that any patient with a thyroid mass and a history of malignancy should be considered to have a metastasis until proven otherwise

A review on nano fibre technology in polymer composites

The enormous attention and interest by both academics and industrial field for greener, biodegradable and renewable materials implicate a persuasive trends towards the encroachment of nano-materials science and technology in the polymer composite field. Nanocomposites creates high impacts on the development of nano materials with advanced features to solve potential risks with their wider industrial applications. Nano fibres are highly engineered fibres with diameters less than 100 nm that offer several advantages over conventional fibres. One dimensional (1D) nanostructure fillers such as carbon nanofibre and cellulose nanofibre are the most common, promising and unique for developing multifunctional nanocomposites with better properties and extensive applications compared to micro size fibres. Nano fibre technology brings revolution by providing products that are completely safe, truly greener, reliable and environmentally friendly for industries, researchers and users. This review article is intended to present valuable literature data on research and trend in the fields of carbon and cellulose nano fiber, nanocomposites with specific focus on various applications for a sustainable and greener environment

Recent advances in epoxy resin, natural fiber-reinforced epoxy composites and their applications

The versatile characteristic of epoxy and its diversity made it suitable for different industrial applications such as laminated circuit board, electronic component encapsulations, surface coatings, potting, fiber reinforcement, and adhesives. However, the pervasive applications in many high-performance field limited the epoxy use because of their delamination, low impact resistance, inherent brittleness, and fracture toughness behavior. The limitations of epoxy can be overcome by incorporation and modification before their industrial applications. Currently, modified epoxy resins are extensively used in fabrication of natural fiber-reinforced composites and in making its different industrial products because of their superior mechanical, thermal, and electrical properties. Present review article designed to be a comprehensive source of recent literature on epoxy structure, synthesis, modified epoxy, bio-epoxy resin, and its applications. This review article also aims to cover the recent advances in natural fiber-based epoxy composites and nanocomposites research study, including manufacturing techniques and their different industrial applications

Fabrication of epoxy nanocomposites from oil palm nano filler: mechanical and morphological properties

The aim of this research was to fabricate epoxy nanocomposites by utilizing the developed nano filler from oil palm mills agricultural wastes oil palm empty fruit bunch (OPEFB) fibers for advanced applications. Epoxy-based polymer nanocomposites were prepared by dispersing 1, 3, and 5 wt. % nano OPEFB filler by using a high speed mechanical stirrer through hand lay-up technique. The mechanical (tensile and impact) properties and morphological properties of nano OPEFB/epoxy nanocomposites were examined and compared. Morphological properties were analyzed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) to look at the dispersion of the nano OPEFB filler in the epoxy matrix. The tensile and impact properties of nanocomposites increased until 3% nano filler loading, but beyond 3% they decreased. Overall mechanical properties reached maximum values for 3% loading, due to better stress transfer owing to homogenous dispersion of nano OPEFB filler within epoxy matrix. The observed results were also confirmed by SEM and TEM micrographs

Thermal properties of oil palm nano filler/kenaf reinforced epoxy hybrid nanocomposites

The aim of this research study was to fabricate nano oil palm empty fruit bunch (OPEFB)/kenaf/epoxy hybrid nanocomposites and to make comparative study on the thermal properties of nano OPEFB/kenaf/epoxy hybrid nanocomposites with the montmorillonite (MMT)/kenaf/epoxy hybrid nanocomposites and organically modified MMT (OMMT)/kenaf/epoxy hybrid nanocomposites. Epoxy based kenaf hybrid nanocomposites was prepared by dispersing the nano filler (nano OPEFB filler, MMT, OMMT) at 3% loading through high speed mechanical stirrer followed by hand lay-up technique. Thermal properties of hybrid nanocomposites were analyzed through thermogravimetry analyzer (TGA), and differential scanning calorimetry (DSC). Obtained results specified that addition of nano OPEFB filler improves the thermal stability and char yield of kenaf/epoxy composites. Furthermore, the increase in decomposition temperature by the nano OPEFB filler was quite comparable to the MMT/kenaf/epoxy but relatively less than OMMT/kenaf/epoxy hybrid nanocomposites. We concluded from overall consequences that the nano OPEFB filler can be used as the promising and innovative alternative of existing expensive nano filler, with relatively lesser impact on the environment having marked pronounced impact on the construction, automotive, aerospace, electronics and semiconducting sectors as future industries based on bio-wastes with satisfactory light weight and thermal stability on other side

A questionnaire based institutional assessment of ‘knowledge’, ‘attitude’ and ‘practice’ about bio-ethics in clinical research among postgraduate residents

Background: Research ethics govern the standards of conduct for scientific researchers. Post graduate residents are one of the key stakeholders in clinical research. Therefore, the present study is designed to assess the Knowledge, Attitude and Practice about bio-ethics in clinical research among post-graduate residents.Methods: A self-administered pretested questionnaire was given to 40 students selected on the basis of convenience sampling. The questionnaire consists of questions related to knowledge and attitude toward principles and practice of bioethics in clinical research, informed consent, and role of the ethics committee in the institution. Descriptive statistics was used to analyse the results.Results: 70% of the students have formally taken Hippocratic Oath. Knowledge, attitude, and practice regarding Institutional Ethics Committee, and informed consent were more among final year students when compared to their juniors. Source of knowledge of bioethics were multiple. Department lectures were not a preferred mode of learning.Conclusions: There is an urgent need to include practical education of ethics to bridge the gap in the knowledge, attitude, and practices regarding ethics in clinical practice and research

An Investigation of Success and Failure Factors of Street Food Sector Entrepreneurs in Sylhet

Street food sector is rapidly growing large informal sector in Sylhet, the holy land of Bangladesh. This study attempts to investigate the success and failure factors of entrepreneurs in the street food sector of Sylhet. The study was descriptive in nature and both qualitative and quantitative data were used. In this study, a total of 50 entrepreneurs of street food business were interviewed on the basis of convenience sampling (non-probability sampling technique) from Sylhet district. A semi-structured questionnaire was used to collect the data from the entrepreneurs with a face to face half an hour interview. Mean, mode, percentile, standard deviation were used in the data analysis. The findings of the study divulge that most of the entrepreneurs of street food sectors are young and male. The study also depicts that lack of experience of the entrepreneurs is the main failure factor of this sector. Along with this insufficient capital, a large amount of bribe, intense competition, undefined location are the key failure factors of this sector. On the other hand, the key success factors include easy formation, lower startup cost, less paperwork, fewer employees. The study also interprets that the government has less regulation in this sector, which is also a crucial success factor in this sector. For the development of this sector, the local government authority should provide some specific location for this sector. A large amount of bribe in this sector also needs to be controlled. The banks and other financial institution should provide SME loan to the entrepreneurs. The study will helps local government authority, policymakers, academician and interested persons to get a better insight into this sector. Keywords: Street food sector, entrepreneurs, success and failures factors, Sylhet. DOI: 10.7176/EJBM/11-9-01 Publication date:March 31st 201

Non-global Structure of the O({\alpha}_s^2) Dijet Soft Function

High energy scattering processes involving jets generically involve matrix elements of light- like Wilson lines, known as soft functions. These describe the structure of soft contributions to observables and encode color and kinematic correlations between jets. We compute the dijet soft function to O({\alpha}_s^2) as a function of the two jet invariant masses, focusing on terms not determined by its renormalization group evolution that have a non-separable dependence on these masses. Our results include non-global single and double logarithms, and analytic results for the full set of non-logarithmic contributions as well. Using a recent result for the thrust constant, we present the complete O({\alpha}_s^2) soft function for dijet production in both position and momentum space.Comment: 55 pages, 8 figures. v2: extended discussion of double logs in the hard regime. v3: minor typos corrected, version published in JHEP. v4: typos in Eq. (3.33), (3.39), (3.43) corrected; this does not affect the main result, numerical results, or conclusion