Launch disasters in Bangladesh: a geographical study

Bangladesh is a riverine country and communication by waterways is of great importance especially in the southern region of the country. From Chandpur southwards, waterway is the only means of transport and so a large number of people has to travel by motor launches in the coastal areas and inland. Since the early 1950's, motor launch services have become popular and in the period 1997-98 there were 1,853 registered launches operating 227 routes. But this important mode is ridden with tragic disasters every year, incurring a heavy toll of human lives. Since 1977, there were 248 motor launch accidents recorded by BIWTA (Bangladesh Inland Water Transport Authority) with a loss of 2,309 1ives, 374 persons injured and 208 persons missing. This paper attempts to roughly trace out the causes and the geographical distribution of the accidents through an analysis of a time series data covering the period between 1977 and 2000. It was found that the most frequent type or cause of launch accidents was collision, followed by foundering and overloading. The least frequent accident types were due to under-water currents, shoals, leaning electricity poles and country boats travelling without lights at night and manned by untrained operators, followed by cyclones. Interestingly, overcrowding did not seem to be the most typical of launch disasters in the countr

Characterization of hydroxyapatite/polypyrrole/poly (caprolactone) based solvent cast thin films

This study addressed the fabrication of thin films composed of Polypyrrole (PPy), hydroxyapatite (HA) and poly (ε-caprolactone) (PCL) via solvent casting method. The polymer and composite films were subsequently characterized in terms of morphology, wettability and water uptake properties using different techniques. The characterization of the thin films were determined using a Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), water contact angle and water uptake. The addition of HA and PPy reduced the hydrophobic properties of PCL in the thin films. An energy dispersive x-ray (EDX) analysis supported the existence of HA in composite thin films. Water uptake of PCL thin film was lower than HA/PCL and HA/PPy/PCL composite thin films. © 2006-2016 Asian Research Publishing Network (ARPN)

Fabrication and characterization of pcl/ha/ppy composite scaffold using freeze-drying technique

Bone tissue regeneration and healing could be notably quickened via applying electrical stimuli in the defected area. Hence, a conductive tissue engineer ing sc affold that is capable of delivering the electrical stimuli is greatly desirable. In this study, electrically conductive sca ffold was fabricated by using a biocompatible conductive polymer, polypyrrole (PPY) in the optimized nanocomposite scaffold of Polyc aprolactone (PCL) and Hydroxyapatite (HA) using freeze – drying technique. The sc affolds were evaluated by using a number of techniques. The morphology of the scaffolds was observed and analyzed using a scanning electron microscope (SEM) . Composite scaffolds with suitable pore size distribution were obtained by freezing the polymer solution mixture at - 18ºC, by controlling the polymer and solvent phase crystallization. The result s showed that the average pore sizes were decreased from 123.7μm for PCL scaffolds to 91.6 μm with the incorporation of HA nanoparticles. Electrical conductivity of the scaffolds was evaluated using a digital multimeter. The wettab ility and porosity of the scaffolds were increase d with the incorporation of Polypy rrole than Polycaprolactone scaffold . The newly fabricated PCL/HA/PPY scaffold showed good prospect to be employed for bone tissue engineering applications

Cellulose acetate electrospun nanofibrous membrane: fabrication, characterization, drug loading and antibacterial properties

Cellulose-based materials are one of the most commonly used materials for biomedical applications, which normally applied as carriers for pharmaceuticals and drug-releasing scaffolds. In this study, cellulose acetate (CA) was used to fabricate the nanofibrous membrane using the electrospinning technique. CA solutions at different concentrations were prepared by dissolving the polymer in a mixture of acetic acid/acetone solvents with the ratio of 3: 1. The field emission scanning electron microscope results showed that electrospinning of 10% (w/v) CA produced nanofibres with many beads. When the CA concentration was increased to 14% (w/v), bead-free nanofibres were produced. The contact angle measurement results confirmed the hydrophilic properties of nanofibres. In order to prevent common bacterial infections, a model drug, Tetracycline • HCL was incorporated into the CA nanofibres. The drug-loaded CA nanofibres showed antibacterial activity against Gram-positive and Gram-negative bacteria. CA nanofibres had high water uptake properties. The CA nanofibrous membrane was non-toxic to human skin fibroblast cells. Thus the CA nanofibres with 14% (w/v) concentration exerted suitable properties for wound healing application

Merchandising activities of ANONTEX Group

This internship report is submitted in a partial fulfillment of the requirements for the degree of Masters of Business Administration, 2015.Cataloged from PDF version of Internship report.Includes bibliographical references (page 35).This Report is prepared as per requirement of the internship phases of MBA program of BRAC University. The study is based on the problem statement, “Merchandising Activities of ANONTEX GROUP”. The main objective of the report is to find out Process which followed by AnonTex in their Merchandising activities. This report starts with a general introduction of “AnonTex group” as well as its mission, Vision and Product detail. Then this report proceeds onto the brief discussion of my Job description part where I provide the information regarding responsibilities of the jobs, Different Aspect of Job performance and about my critical observation and recommendation. My job in AnonTex was to assist commercial department in their activities. Then in the analysis part of the report, I discussed the process of merchandising of AnonTex describing the different steps of it. The steps are arranging sample development according to demand, collect L/C document, place order to supplier, monitor work progress and shipping the product and collect payment. I also provide the list of valued client of Anontex group and other information relating Anontex group merchandising activities. In findings part, I have tried to find out the satisfaction of buyer relating to AnonTex merchandising activities. Where the major outcomes are in product sample testing 50% like it instantly, 50% strongly agree that AnonTex sewing quality is excellent, 40% agrees that their packing quality is standard, but 30% has dissatisfaction regarding product delivery time, and 70% buyers pay their payment in due time. Finally I suggested some scopes of improvement process of AnonTex and in the conclusion I give a brief summary of the whole report.Ismat Ara NazninM. Business Administratio

Beyond Reuse Distance Analysis: Dynamic Analysis for Characterization of Data Locality Potential

Emerging computer architectures will feature drastically decreased flops/byte (ratio of peak processing rate to memory bandwidth) as highlighted by recent studies on Exascale architectural trends. Further, flops are getting cheaper while the energy cost of data movement is increasingly dominant. The understanding and characterization of data locality properties of computations is critical in order to guide efforts to enhance data locality. Reuse distance analysis of memory address traces is a valuable tool to perform data locality characterization of programs. A single reuse distance analysis can be used to estimate the number of cache misses in a fully associative LRU cache of any size, thereby providing estimates on the minimum bandwidth requirements at different levels of the memory hierarchy to avoid being bandwidth bound. However, such an analysis only holds for the particular execution order that produced the trace. It cannot estimate potential improvement in data locality through dependence preserving transformations that change the execution schedule of the operations in the computation. In this article, we develop a novel dynamic analysis approach to characterize the inherent locality properties of a computation and thereby assess the potential for data locality enhancement via dependence preserving transformations. The execution trace of a code is analyzed to extract a computational directed acyclic graph (CDAG) of the data dependences. The CDAG is then partitioned into convex subsets, and the convex partitioning is used to reorder the operations in the execution trace to enhance data locality. The approach enables us to go beyond reuse distance analysis of a single specific order of execution of the operations of a computation in characterization of its data locality properties. It can serve a valuable role in identifying promising code regions for manual transformation, as well as assessing the effectiveness of compiler transformations for data locality enhancement. We demonstrate the effectiveness of the approach using a number of benchmarks, including case studies where the potential shown by the analysis is exploited to achieve lower data movement costs and better performance.Comment: Transaction on Architecture and Code Optimization (2014

PEDOT:PSS-containing nanohydroxyapatite/chitosan conductive bionanocomposite scaffold: fabrication and evaluation

Conductive poly(3,4-ethylenedioxythiophene)-poly(4-styrene sulfonate) (PEDOT:PSS) was incorporated into nanohydroxyapatite/chitosan (nHA/CS) composite scaffolds through a freezing and lyophilization technique. The bionanocomposite conductive scaffold was then characterized using several techniques. A scanning electron microscope image showed that the nHA and PEDOT:PSS were dispersed homogeneously in the chitosan matrix, which was also confirmed by energy-dispersive X-ray (EDX) analysis. The conductive properties were measured using a digital multimeter. The weight loss and water-uptake properties of the bionanocomposite scaffolds were studied in vitro. An in vitro cell cytotoxicity test was carried out using mouse fibroblast (L929) cells cultured onto the scaffolds. Using a freezing and lyophilization technique, it was possible to fabricate three-dimensional, highly porous, and interconnected PEDOT:PSS/nHA/CS scaffolds with good handling properties. The porosity was 74% and the scaffold's conductivity was 9.72 ± 0.78 μS. The surface roughness was increased with the incorporation of nHA and PEDOT:PSS into the CS scaffold. The compressive mechanical properties increased significantly with the incorporation of nHA but did not change significantly with the incorporation of PEDOT:PSS. The PEDOT:PSS-containing nHA/CS scaffold exhibited significantly higher cell attachment. The PEDOT:PSS/nHA/CS scaffold could be a potential bionanocomposite conductive scaffold for tissue engineering

Fabrication and characterization of chitosan coated and uncoated pcl/ha/ppy composite scaffoldsusing freeze drying technique

Chitosan is an abundantly common, naturally occurring, polysaccharide biopolymer. In this study, chitosan was used to coat previously fabricated conductive Polycaprolactone/Hydroxyapatite/Polypyrrole (PCL/HA/PPY) composite scaffold and the properties of the coated and non-coated scaffolds were investigated and compared. The morphology of the chitosan coated and non-coated scaffolds were characterized using a scanning electron microscope (SEM). The wettability was determined using a water contact angle measuring system. Furthermore, water uptake was determined by measuring the water absorption of each sample before and after coated with chitosan. Water contact angle result revealed an increase in wettability of the scaffolds ranging from 108° ± 4.2 down to 59.4° ± 0.7. On the other hand, the coated sample showed a higher water uptake than the non-coated sample. The results indicated that coating with chitosan was important to increase water absorption of composite scaffold, rendering it more hydrophilic

Effects of Chitosan Alkali Pretreatment on the Preparation of Electrospun PCL/Chitosan Blend Nanofibrous Scaffolds for Tissue Engineering Application

Recently, nanofibrous scaffolds have been used in the field of biomedical engineering as wound dressings, tissue engineering scaffolds, and drug delivery applications. The electrospun nanofibrous scaffolds can be used as carriers for several types of drugs, genes, and growth factors. PCL is one of the most commonly applied synthetic polymers for medical use because of its biocompatibility and slow biodegradability. PCL is hydrophobic and has no cell recognition sites on its structure. Electrospinning of chitosan and PCL blend was investigated in formic acid/acetic acid as the solvent with different PCL/chitosan ratios. High viscosity of chitosan solutions makes difficulties in the electrospinning process. Strong hydrogen bonds in a 3D network in acidic condition prevent the movement of polymeric chains exposed to the electrical field. Consequently, the amount of chitosan in PCL/chitosan blend was limited and more challenging when the concentration of PCL increases. The treatment of chitosan in alkali condition under high temperature reduced its molecular weight. Longer treatment time further decreased the molecular weight of chitosan and hence its viscosity. Electrospinning of PCL/chitosan blend was possible at higher chitosan ratio, and SEM images showed a decrease in fiber diameter and narrower distribution with increase in the chitosan ratio