Short bamboo fiber reinforced polypropylene composites were prepared by incorporation of various loadings of chemically modified bamboo fibers. Maleic anhydride grafted polypropylene (MA-g-PP) was used as compatibilizer to improve fiber-matrix adhesion. The effects of bamboo fiber loading and modification of the resin on the physical, mechanical, thermal, and morphological properties of the bamboo reinforced modified PP composites were studied. Scanning electron microscopy studies of the composites were carried out on the interface and fractured surfaces. Thermogravimetric analysis and IR spectroscopy were also carried out. At 50% volume fraction of the extracted bamboo fiber in the composites, considerable increase in mechanical properties like impact, flexural, tensile, and thermal behavior like heat deflection temperature were observed.
BackgroundConcerns have been raised about the public health implications of the presence of antibiotic residues in the aquatic environment and their effect on the development of bacterial resistance. While there is information on antibiotic residue levels in hospital effluent from some other countries, information on antibiotic residue levels in effluent from Indian hospitals is not available. Also, concurrent studies on antibiotic prescription quantity in a hospital and antibiotic residue levels and resistant bacteria in the effluent of the same hospital are few. Therefore, we quantified antibiotic residues in waters associated with a hospital in India and assessed their association, if any, with quantities of antibiotic prescribed in the hospital and the susceptibility of Escherichia coli found in the hospital effluent.MethodsThis cross-sectional study was conducted in a teaching hospital outside the city of Ujjain in India. Seven antibiotics - amoxicillin, ceftriaxone, amikacin, ofloxacin, ciprofloxacin, norfloxacin and levofloxacin - were selected. Prescribed quantities were obtained from hospital records. The samples of the hospital associated water were analysed for the above mentioned antibiotics using well developed and validated liquid chromatography/tandem mass spectrometry technique after selectively isolating the analytes from the matrix using solid phase extraction. Escherichia coli isolates from these waters were tested for antibiotic susceptibility, by standard Kirby Bauer disc diffusion method using Clinical and Laboratory Standard Institute breakpoints.ResultsCiprofloxacin was the highest prescribed antibiotic in the hospital and its residue levels in the hospital wastewater were also the highest. In samples of the municipal water supply and the groundwater, no antibiotics were detected. There was a positive correlation between the quantity of antibiotics prescribed in the hospital and antibiotic residue levels in the hospital wastewater. Wastewater samples collected in the afternoon contained both a higher number and higher levels of antibiotics compared to samples collected in the morning hours. No amikacin was found in the wastewater, but E.coli isolates from all wastewater samples were resistant to amikacin. Although ciprofloxacin was the most prevalent antibiotic detected in the wastewater, E.coli was not resistant to it.ConclusionsAntibiotics are entering the aquatic environment of countries like India through hospital effluent. In-depth studies are needed to establish the correlation, if any, between the quantities of antibiotics prescribed in hospitals and the levels of antibiotic residues found in hospital effluent. Further, the effect of this on the development of bacterial resistance in the environment and its subsequent public health impact need thorough assessment.
Environmentally benign, low cost and abundantly available short pineapple leaf fibers (PALF), found mostly in the Tropical rain forest climates are ideal materials for manufacture of thermoplastic polymer-matrix composites. Here, mechanical and thermal properties of composites of maleic anhydride grafted polypropylene (MA-g-PP) and chemically modified short PALF are studied as a function of different fiber lengths at 10 vol % fibers loading with fiber orientation in the longitudinal direction. The effects of fiber lengths and fiber loading on the morphological properties are assessed via observations by scanning electron microscopy. Fiber length of 6 mm oriented longitudinally at 10 vol % fibers loading in PP is the optimum and recommended composition, where 73% increase in impact properties, 37% increase in the flexural modulus, 33% increase in flexural strength, and 14% increase in vicat softening temperature are observed.
Optical plastics have been the priority area of research for material scientists worldwide, mainly, to find alternative materials to glass, a conceptual optical material in use over the years. There are numerous advantages of using plastics for optical applications, in particular for ophthalmic applications over glass. Recently, the researchers have been putting their efforts to develop novel plastic materials to meet requirements of ophthalmic industries. The present review compiles the recent developments in the area of optical plastics. The aim is to present the current state-of-the-art in the field, besides analyzing the various aspects of developing optical plastics. The review presents various possible approaches to achieve the desired properties e.g. high refractive index of the optical plastic materials.
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