Papers by Dr. Sohrab Hossain
DESALINATION AND WATER TREATMENT, 2021
ABSTRACT The objective of this study is to determine the coagulation efficiencies on total solids... more ABSTRACT The objective of this study is to determine the coagulation efficiencies on total solids (TS) removal from semiconductor wastewater by applying various locally available starches as natural coagulants. Two commercial coagulants such as alum [Al2(SO4)3•18H2O] and polyaluminium chloride (PAC) were also utilized in this study in order to compare the coagulation efficiency with the natural coagulants. The EDX analysis of the raw semiconductor wastewater showed that it contained silica dioxide (SiO2) with a concentration of 90%. It appeared that the natural coagulants employed in the study have similar coagulation characteristics with the commercial coagulants. However, the natural coagulants possess better metal adsorption capability than the commercial coagulants. A 3 level factorial experimental design was used in the Response Surface Methodology (RSM) analysis and indicated that starches are capable to remove TS from the semiconductor wastewater and the removal performance were almost similar to alum and higher than PAC.
Materials Science Forum, 2008
Page 1. Residual stress and microstructural variations in thick aluminium alloy forgings JS Robin... more Page 1. Residual stress and microstructural variations in thick aluminium alloy forgings JS Robinson 1,a CE Truman 2,b S. Hossain 2,c R. Wimpory 3,d 1Materials and Surface Science Institute, University of Limerick, Ireland. ...
Perspectives of Fullerene Nanotechnology, 2002
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Polymers, 2015
ABSTRACT Disposal Options of Bamboo Fabric-Reinforced Poly(Lactic) Acid Composites for Sustainabl... more ABSTRACT Disposal Options of Bamboo Fabric-Reinforced Poly(Lactic) Acid Composites for Sustainable Packaging: Biodegradability and Recyclability
In recent years, utilization of natural fibre as reinforced materials in polymer biocomposites ha... more In recent years, utilization of natural fibre as reinforced materials in polymer biocomposites has gained impetus. Research efforts are currently being harnessed in developing more sustainable products. Oil palm biomass contributes among the highest and most abundant wastes with high potential for energy and material resources. Oil palm consists only around 10% of oil, leaving another 90% as biomass wastes. The remainder consists of a huge amount of lignocellulosic materials in the form of fronds, trunks, empty fruit bunches (EFB), oil palm shell (OPS), palm pressed fibre (PPF), oil palm ash (OPA), etc. Biocomposites enhanced with biofiller have been used extensively in various fields because this filler behave isotropically to the matrix. Several researches have been worked on utilizing various oil palm biomasses as filler in polymer biocomposites ranging from micro to nano size. In producing high performance biocomposites, mechanical properties would mainly taking into considerati...
Industrial Crops and Products, 2015
ABSTRACT Response surface methodology (RSM) was used to determine the effects of high pressure ho... more ABSTRACT Response surface methodology (RSM) was used to determine the effects of high pressure homogenization (HPH) parameters (pressure and number of cycles) on the isolated yield, crystallinity, and diameter of kenaf bast cellulose nanofibers (CNF). Central composite design of experiments was utilized to determine the optimal pressure and number of cycles of HPS for the highest CNF yield, crystallinity, and lowest CNF diameter. The linear terms for the pressure and homogenization cycles had significant effects on the CNF yield, crystallinity, and diameter, whereas the interaction between the pressure and homogenization cycles had a significant effect on the CNF crystallinity. The optimized experimental conditions for the HPH process were a homogenization pressure of 56 MPa, 44 P homogenization cycles, and a 0.1 wt% fiber suspension concentration. Under these conditions, the isolated kenaf bast CNF yield was 89.9% with 56.5% CNF crystallinity and a CNF diameter of 8 nm.
BioResources, 2015
ABSTRACT The durability of vinyl ester composites filled with carbonized jatropha seed shell was ... more ABSTRACT The durability of vinyl ester composites filled with carbonized jatropha seed shell was investigated in 5% NaOH solution, 5% HCl solution, and distilled water for 12 months. The environmental durability of the composites was determined by measuring weight changes, flexural properties, and tensile properties. Results showed weight gain and changes in the mechanical properties of the composites due to the soaking time in alkaline, acidic, and neutral environments. It was observed that vinyl ester composites had the highest tensile properties in alkaline environments. The highest flexural properties of the vinyl ester composites were observed in an alkaline environment. Scanning electron microscope image analysis revealed that the surface of the vinyl ester composites was rough and that the original luster was lost after soaking in alkaline solution, acidic solution, and distilled water for 12 months.
ABSTRACT The extraction behavior of copper, zinc and iron were studied using a column in which mi... more ABSTRACT The extraction behavior of copper, zinc and iron were studied using a column in which microcapsules coated Cyanex 272 was packed. The extractions were carried out in different pH (2-5) and showed that the pH values of the feed solution were important for successful separation of the metal ions. It was observed that extraction of metal ions increased with the increasing of pH values of the feed solution and highest separation was found at higher pH levels. At pH 4, zinc and iron were completely extracted .It was found in stripping investigation that it was possible to separate all metals adsorbed into the column from eluent by selecting the sulphuric acid concentration of the stripping solution. Finally, the stability experiment showed that the microcapsules had a sufficient metal ions extraction capacity for reuse processing and extraction–stripping cycles indicated no decline in extractability. Introduction The leading consumers of copper are wire mills and brass mills, which use the copper to produce copper wire and copper alloys, respectfully. End use of copper include construction materials, electronic products, and transportation equipment. The use of zinc coating for corrosion protection of steel structure is the most important application owing to the high corrosion resistance of zinc in atmospheric and other. Nearly half of zinc produced is used for this purpose. Iron is the most used of all the metals, comprising 95% of the entire metal tonnage produced world wide. It's combinations of low cost and high strength make it indispensable, especially in applications like automobile, the hulls of large ships, and structural components for building. Steel is the best known alloy of iron. Liquid-liquid extraction has been used in many industrial fields, but has been prevented from application to new developing commercial processes due to inherent disadvantage, such as phase separation and solvent entrainment. Some potential methods can overcome theses disadvantage and immobilizing the extractant through microencapsulation is highly promising [1, 2, 3. and 4]. There are several advantages compared with conventional liquid-liquid extraction, such as large specific interfacial area, high selectivity, minimal use of organic solvents, and easy phase separation. Nishihama et al. [5] prepared a microcapsules consisting bis(2-ethylhexyl) phosphoriic acid and found that a high loading of rare earth metals up to 0.8 is achieved, but that in the liquid-liquid extraction system is limited to about 0.4 due to phase separation problems. Therefore in the present studies, microcapsules coated with Cyanex 272 was chosen to separate metals ion from the aqueous solution of mixed metal ions. Experiment Reagents Dichloromethane (DCM), polystyrene, gum Arabic, acetic acid, sulfuric acid, cupric sulphate, zinc sulphate and ferric sulphate were all analytical grade reagents. Cyanex 272 supplied by Cytec Canada was used as extractant. The aqueous of Cu(II), Zn(II) and Fe(III) were prepared by dissolving cupric sulphate, zinc sulphate and ferric sulphate in distilled water followed by adjusting pH value with H 2 SO 4 or NaOH.
ABSTRACT There is current uncertainty regarding the transient uplift capacity of skirted foundati... more ABSTRACT There is current uncertainty regarding the transient uplift capacity of skirted foundations, relative to compressive capacity, and also the time over which uplift can be sustained. In this paper, the first of these issues is addressed through half and full model tests conducted at 200g in a drum centrifuge. Undrained vertical bearing capacities in compression and uplift were measured in the full model tests, while the failure mechanisms were examined using Particle Image Velocimetry (PIV) analysis of the images captured during half model tests, aiding interpretation of the measured bearing responses. The study showed that a reverse end bearing mechanism can be mobilized in uplift and that undrained vertical bearing capacity factors of similar magnitude can be expected in compression and uplift, even for a foundation with relatively shallow embedment. The results are promising for optimizing shallow skirted foundation design for a range of offshore structures that experience transient uplift loading.
Proceedings 76th EAGE Conference and Exhibition Workshops, 2014
Renewable and Sustainable Energy Reviews, 2015
ABSTRACT In recent years, the use of plant fibers has increased tremendously due to the remarkabl... more ABSTRACT In recent years, the use of plant fibers has increased tremendously due to the remarkable variations in chemical and physical properties. Plants require light, water, and nutrients for growth, reproduction and efficient crop production. Plant nutrients are mostly absorbed by plant roots from soil. For satisfactorily plant growth, it is urgency that soil provides a favorable environment for root development that can exploit the soil sufficiently. Water exists in soil as a thin film which has very different properties to that of a bulk volume of the same water. The organic part forms complex interactions with the water, minerals, solute, and microorganisms of the soil, compounding the complexity of the system. Furthermore, soil is a dynamic open system, continually subject to inputs and losses of energy, water, organic and inorganic materials, and supports the plant structurally. The physical, chemical and biological properties of soil lead to a series of physiological, biological and chemical changes along with growth, yield and quality of the plant biomass, and thus of fibers. The purpose of this review is to summarize the impacts of the soil properties on the physical and morphological structure of plant fibers growth. The present study further demonstrated the interaction effects and sustainability of soil properties to produce quality plant fibers.
Chemical Engineering Journal, 2015
ABSTRACT In the present study, steam autoclaving and supercritical carbon dioxide (SC-CO2) were u... more ABSTRACT In the present study, steam autoclaving and supercritical carbon dioxide (SC-CO2) were utilized to inactivate Enterococcus faecalis, Escherichia coli, and Bacillus sphaericus in clinical solid waste. The success of steam-based bacterial sterilization depends on temperature, treatment time, and the bacterial species present. Autoclave sterilization was found to be most effective at 121°C for 60 min and 131°C for 30 min. Complete inactivation of bacteria in clinical solid waste subjected to SC-CO2 sterilization was obtained after 30-120 min at a treatment range of 10-40 MPa and 35-80°C. The bacterial inactivation curves, which were generated using a modified Gompertz model to describe the relationship between survival rate and treatment time, was divided into three distinct phases. Scanning electron microscopy, bacterial protein, and enzymatic activity analyses showed that steam autoclaving physically inactivated bacteria by denaturing cellular enzymes, thereby inhibiting their activities. In contrast, SC-CO2 inactivated bacteria both physically and chemically. The reduction of proteins and enzymatic activity in SC-CO2-treated bacterial cells suggested that these cellular components were destroyed by the SC-CO2. The absence of re-growth after SC-CO2 sterilization and its promising bacterial inactivation efficiency suggested that it was an effective method for the treatment of infectious clinical solid waste. Therefore, SC-CO2 sterilization could be utilized in clinical solid waste management to eliminate infectious exposure and to improve the hygienic recycling and reuse of clinical solid waste materials.
Waste Management, 2015
Clinical solid waste (CSW) poses a challenge to health care facilities because of the presence of... more Clinical solid waste (CSW) poses a challenge to health care facilities because of the presence of pathogenic microorganisms, leading to concerns in the effective sterilization of the CSW for safe handling and elimination of infectious disease transmission. In the present study, supercritical carbon dioxide (SC-CO2) was applied to inactivate gram-positive Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis, and gram-negative Escherichia coli in CSW. The effects of SC-CO2 sterilization parameters such as pressure, temperature, and time were investigated and optimized by response surface methodology (RSM). Results showed that the data were adequately fitted into the second-order polynomial model. The linear quadratic terms and interaction between pressure and temperature had significant effects on the inactivation of S. aureus, E. coli, E. faecalis, and B. subtilis in CSW. Optimum conditions for the complete inactivation of bacteria within the experimental range of the studied variables were 20MPa, 60°C, and 60min. The SC-CO2-treated bacterial cells, observed under a scanning electron microscope, showed morphological changes, including cell breakage and dislodged cell walls, which could have caused the inactivation. This espouses the inference that SC-CO2 exerts strong inactivating effects on the bacteria present in CSW, and has the potential to be used in CSW management for the safe handling and recycling-reuse of CSW materials.
Journal of Water Resource and Protection, 2013
Journal of Chemical Technology & Biotechnology, 2014
ABSTRACT Recent technological advances and the development of new methods has provided an opportu... more ABSTRACT Recent technological advances and the development of new methods has provided an opportunity to obtain highly purified natural bioactive compounds extracts with potential for the treatment and prevention of human diseases. The use of hazardous and toxic solvents in extraction and processing of bioactive compounds from plant materials is considered as a big problem in health, safety and environmental pollution. Advanced technology aims to increase the production of the desired compounds and find an alternative to using toxic solvents in the extraction processes of bioactive compounds from plant materials. The ever growing interest in plant bioactive compounds and today's concern on environment issues have led to an increase need for efficient and green extraction method. This review is focused on the extraction of bioactive compounds from plant using advanced and environmental friendly methods such as supercritical fluid extraction method, microwave-assisted extraction method, ultrasound-assisted extraction and similar techniques that can give fast and organic residues free extract. An update overview of the bioactive compounds present in plant of Phaleria macrocarpa and its extraction, fractionation, purification and isolation are provided. The advantages and disadvantages of both conventional and non-conventional extraction methods are also discussed in this review.
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Papers by Dr. Sohrab Hossain