Abstract/Overview In this study, the fingerprint of the acid concentration during the hydrolysis process on the optical band gap of cellulose nanocrystals (CNCs) has been systematically studied. The CNCs have been prepared using hydrochloric acid at a hydrolysis temperature of 50°C and at a constant hydrolysis time of 4 hours but with varying hydrochloric acid concentrations of 5%, 10% and 15%. The crystalline structure and phase identification of the CNCs have been studied using XRD tec...
Abstract: Nanomaterials have been used recently in food packaging as antibacterial coatings because of their desirable antibacterial and antifungal properties. The use of antimicrobial packaging is to deter the growth of microorganisms responsible for spoilage or diseases in packaged foods, therefore prolonging their shelf life. In this study, potato peel starch and ZnO-starch nanocomposite paper (ZnO-starch NC paper) were developed and evaluated for antibacterial activity against Esche...
Abstract: Vetiver grass (Chrysopogon zizanioides;CZ) is a well-known grass that can both remediate various heavy metals in soil as well as producing essential oil that is commonly used in premier perfumery, food and pharmaceutical industries. Due to this versatility property, this study was aimed at extracting essential oil from Chrysopogon zizanioides roots cultivated in SelibePhikwe mine tailings and study the quality and quantity (chemical composition and yield) of the Chrysopogon ziza...
Abstract: Composites of titanium nitride reinforced with graphite were synthesized using spark plasma sintering at 2000 °C. The effects of graphite addition on the microstructure, relative density, and mechanical properties of TiN ceramics matrix were examined. The investigation was performed on TiN powder with varying graphite content (1–5 wt.%) for 8 h using an energy ball milling equipment. Results show that TiN without and with graphite (TiN + 1 wt.% graphite) sintered at 2000 °C rec...
Abstract: Polymer waste that has been viewed as a major threat to our environment is currently gaining attention as valuables resources are being obtained from it. Researchers are now developing nanocomposites/blends from plastic wastes as a way of recycling waste plastic rather than employing incineration and landfilling methods of recycling that are not environmentally friendly. The utilization of nanofiller to recycle waste polymers will enhance the mechanical, thermal and optical propert...
Abstract: Research on semiconducting metal oxide (MO) nanostructures is a fascinating field that has received massive interest due to their significant physical and chemical properties which can be useful in the development of highly efficient nanodevices. Incorporating impurities such as metal elements into the MO matrix offers tailored properties for various applications. Doped MO nanostructures exhibit modified structural, optical, electrical and morphological properties rendering th...
Abstract: Green nanotechnology is an innovative research field with emphasis on the development of methods that minimize the use of health hazardous substances for environmental remediation. This study reports on the biosynthesis of nanostructured multilayer graphene (MLG) and zinc oxide (ZnO) from natural extracts for environmental applications. ZnO nanoparticles are fabricated for the first-time using Ageratum Houstonianum leaf extract as an effective chelating agent. Besides this, a ...
Abstract: Continuous discharge of textile wastes such as dyes into the water bodies deteriorates the quality of water. Therefore, the removal of these materials from the wastewater should be a priority due to their carcinogenic properties, which pose a health hazard to both human beings and aquatic life. The use of advanced oxidation processes (AOPs) for example heterogeneous photocatalysis has been broadly studied due to their efficacy in the removal of such organic contaminants. Engin...
Abstract: The development of transparent conducting oxide materials has gained an increased interest in the scientific community for developing efficient low cost optoelectronic devices. The effect of Cd precursor on structural and optical properties of sol-gel synthesized Zn0.9Cd0.1O nanostructured films has been studied by using XRD, AFM, optical absorption and emission spectroscopic techniques. X-ray diffraction confirms the hexagonal wurtzite crystal structure of the deposited films and ...
Abstract: Doping is an effective material re-engineering technique, which provides a possibility of improving properties of materials for different applications. Herein, a Zr-doped TiO2 thin film was deposited applying the chemical spray pyrolysis method and the influence of varying zirconium dopant concentrations on the properties of the film was studied. Morphological studies showed that the Zr–TiO2 films were homogeneous with smaller grain sizes compared to the undoped TiO2 films. As-de...
Abstract: Agricultural residue-based fibrous (ARF) materials have been identified to be a commercially viable solution for energy-efficient building insulation application. ARFs have various advantages over synthetic fibers including environmentally friendly, light weight, low cost, and competent mechanical properties. Meanwhile, in many African countries including Botswana, the expertise to manufacture building insulators by using ARFs is scarce and consequently building insulation material...
Non-renewable energy sources produced from natural coal and oil may result in climate change and global warming as greenhouse gases are to the environment. This is why the main utilization of energy sources on renewable and alternate green energy to deliver power. Thus, a microbial fuel cell device is one of the cost-effective and environmentally friendly energy conversion devices that uses renewable organic wastes as fuel source and converts this stored chemical energy in to useful b...
ABSTRACT A semi-mechanistic model for predicting the flow behaviour of Fe-Mn-Mo steels displaying transformation-induced plasticity is developed in this paper. The model, based on the law of mixtures, takes into account the work-hardening of the individual principal phases (namely, lath-martensite and austenite/epsilon martensite). The composite strength of such a steel may be given by a modified law of mixtures which incorporates a dislocation density effect. To test the validity of the m...
ABSTRACT Thermodynamic data is made use of in calculating fraction of metal solidified in solidification simulation. However, thermodynamic data for many industrial alloys in their solidification ranges are not available for most practicing engineers. It is thus desirable to develop reliable equations that can be used in calculating fraction of metal solidified for solidification simulation. This work has developed an equation to calculate fraction of metal solidified for AlSi7Mg alloy solid...