Preparation and characterization of artificial skin using chitosan and gelatin composites for potential biomedical application
Polymer Bulletin, 2012
A bioadhesive wound-dressing material based on the combination of gelatin and chitosan with a pro... more A bioadhesive wound-dressing material based on the combination of gelatin and chitosan with a proper ratio was developed and successfully applied in biomedical fields. The composite films were prepared with increase in chitosan concentration in a fixed amount of gelatin and were evaluated for mechanical stability (e.g., tensile strength, elongation-at-break), water and buffer uptake capacity, water and buffer aging, molecular structure, morphology, thermal stability, and for biological properties (e.g., antimicrobial activity, cytotoxicity, in vivo wound-healing performance). It is noteworthy that the 10:3 (gelatin:chitosan) composite films showed the best physico-mechanical, thermal, and antimicrobial properties among the other ratios blend films. The improved mechanical and thermal stability of the 10:3 composite film suggested its promising use as carrier for controlled release drug. The composite film was evaluated using a rat model for in vivo tests to ascertain the applicability of the proper ratio of the chitosan and gelatin in the film for best wound-healing activity. Wound sites dresses with gelatin/chitosan composite films showed excellent rapid healing of the wound surface than those dressed with eco-plaster and gauze. Within a day after dressing with 10:3 composite film, the healing efficiency was found to be 80 %.
Among various thermo-chemical conversion processes, pyrolysis is considered as an emerging techno... more Among various thermo-chemical conversion processes, pyrolysis is considered as an emerging technology for liquid oil production. The conversion of biomass waste in the form of plum seed into pyrolysis oil by fixed bed pyrolysis reactor has been taken into consideration in this study. A fixed bed pyrolysis has been designed and fabricated for obtaining liquid fuel from this plum seeds. The major component of the system are fixed bed pyrolysis reactor, liquid condenser and liquid collectors. The plum seed in particle form is pyrolysed in an externally heated 7.6 cm diameter and 46 cm high fixed bed reactor with nitrogen as the carrier gas. The reactor is heated by means of a biomass source cylindrical heater from 400 0 C to 600 0 C. The products are oil, char and gas. The reactor bed temperature, running time and feed particle size are considered as process parameters. The parameters are found to influence the product yield significantly. A maximum liquid yield of 39 wt% of biomass feed is obtained with particle size of 2.36-4.75 mm at a reactor bed temperature of 520 o C with a running time of 120 minutes. The pyrolysis oil obtained at this optimum process conditions are analyzed for some fuel properties and compared with some other biomass derived pyrolysis oils and conventional fuels. The oil is found to possess favorable flash point and reasonable density and viscosity. The higher calorific value is found to be 22.39 MJ/kg which is higher than other biomass derived pyrolysis oils.
PurposeThe main purpose of this study is to assess the effects of COVID-19 on the restaurant busi... more PurposeThe main purpose of this study is to assess the effects of COVID-19 on the restaurant businesses of Bangladesh. It examines the socio-economic impacts of the humanitarian disaster of the COVID-19 pandemic from the perspective of restaurant owners. The study also intends to provide recommendations to mitigate effects on the restaurant business.Design/Methodology/ApproachA qualitative research approach was adopted to explore the effects of the COVID-19 pandemic on the restaurant businesses of Bangladesh. A total of 22 in-depth interviews were conducted with the top-ranked restaurant owners in the Rajshahi City Corporation area of Bangladesh. Thematic analysis technique was applied for analyzing the collected data.FindingsThe study found that the restaurant owners were compelled to reduce their number of employees, and forced to ensure social distancing and proper sanitization which increased the expenses. Although online orders and home delivery services have increased signific...
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Papers by Shahed Parvez