Industrialization plays a vital role in the development of a country’s economy. However, it also adversely affects the environment by discharging various unwanted and harmful substances such as heavy metals into the surface and subsurface aquifers. The current research work investigates the identification, characterization, and evaluation of specific heavy metals in industrial wastewater (IWW) and different composite samples of soil and vegetables (onion, pumpkin, lady finger, and green pepper) collected from selected agricultural fields irrigated with canals fed IWW in Mingora city of Swat (Pakistan). Obtained results were compared with the tube well water irrigated soil and vegetables grown in it. Heavy metals accumulation was tested through wet digestion method and atomic absorption spectrophotometry (AAS). The metal transfer factor (MTF) of heavy metals from soil to vegetables was also determined along with the health index (HI) to assess the potential health risk of the metals towards consumers using Monte Carlo simulation technique. Analysis of water samples showed that the concentration in mg l-1 of heavy metals in IWW follows the trend Fe (6.72) > Cr (0.537) > Pb (0.393) > Co (0.204) > Mn (0.125) > Ni (0.121). Analysis of the soil samples irrigated with IWW followed the order of Fe (47.27) > Pb (2.92) > Cr (2.90) >Ni (1.02) > Mn (0.90) > Co (0.68) and Fe (17.12) > Pb (2.12) > Cr (2.03) >Ni (0.76) > Co (0.49) > Mn (0.23) irrigated with TWW. Heavy metals concentration values found in soil irrigated with IWW were higher than the soil irrigated with TWW. Similar trends were found for agricultural produces grown on soil irrigated with IWW and found higher than the normal allowable WHO limits, indicating higher possibilities of health risks if continuously consumed. MTF values were found higher than 1 for ladyfinger and green pepper for Pb intake and pumpkin for Mn intake. The current study suggests the continuous monitoring of soil, irrigation water and agricultural products to prevent heavy metals concentration beyond allowable limits, in the food chain. Thus, concrete preventive measures must be taken to reduce heavy metal accumulation through wastewater irrigation to protect both human and animal health in the study area of Mingora Swat Pakistan.
The current work presents the development of hybrid glass fiber reinforced polyester resin (GFRPs) composite. The composite integrates functionalized carbon nanotubes (f-MWCNTs) with glass fiber (GF) using polyester resin as a media. Hand lay-up method was adopted to prepare GFRPs samples in the form of rectangular sheets. Morphological characteristics of the GFRPs were investigated through scanning electron microscopy (SEM), to analyze the f-MWCNTs distribution and agglomeration of the developed composite’s surface due to varying concentrations from 0.0 to 0.5 wt.%. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were performed to confirm the presence of f-MWCNTs in the developed GFRPs. Sample with 0.4 wt. % f-MWCNTs showed the highest tensile strength and impact energy of 79 MPa, indicating a 31.66% improvement and 1.6 Nm with 77% improvement, respectively as compared to the control sample (0.wt.% f-MWCNT). The same sample also showed the thermal stability till 390 °C as measured through thermogravimetric analysis (TGA). Deposition of extra 10 layers initially increased the composite strength from 40 MPa to 128 MPa, however further increase in layers to 15 resulted decrease in strength to 100 MPa due to the poor interaction between the polyester resin and GF. The addition of f-MWCNTs in the composite effectively strengthens the interfacial bonding, which significantly improved the tensile and impact strength of the composite, making it tougher and thermally stable. However, further increase in the concentration of f-MWCNTs degraded the mechanical properties of developed composite such as compressive strength because of agglomeration of these nanoparticles and void formation in the composite.
In this work, the effects of different fiber loadings on the mechanical properties of the composites at the sub-micron scale were studied through nanoindentation followed by physical characterization. The composites were prepared by incorporating different loadings of wheat straw, corn stalk, and rice husk in polypropylene copolymer using a melt processing method followed by thermal–hydraulic compression technique. Nanoindentation experiments in quasi-continuous stiffness mode were performed on the surfaces of produced composites to study the composites’ elastic modulus, hardness, and creep properties. The obtained results expressed the in-depth study of the micro- and macro-level structure and behavior of particle interactions. The findings demonstrated that observable shifts in composites’ hardness, elastic modulus, and creep rate had occurred. The WS-reinforced biocomposite sheet showed the highest elastic modulus of 1.09 and hardness of 0.11 GPa at 40 wt% loading in comparison to other loadings. An impact strength of 7.55 kJ/m2 was noted for the biocomposite at 40 wt% RH loading. In addition, optical microscopy, Fourier transform infrared spectroscopy, water absorption, thickness swelling, and Vicat softening point studies were conducted on biocomposite sheets to evaluate differences in physical, mechanical, and thermal properties. The outstanding mechanical performance of the newly developed composites makes them suitable for use as a biodegradable packaging material.
22 September 2014 in Journal of Electrochemical Science and Engineering
Tremendous potential for successful medical device development lies in both electrical stimulation therapies and neuronal prosthetic devices, which can be utilized in an extensive number of neurological disorders. These technologies rely on the successful electrical stimulation of biological tissue (i.e. neurons) through the use of electrodes. However, this technology faces the principal problem of poor stimulus selectivity due to the currently available electrode’s large size relative to its targeted population of neurons. Irreversible damage to both the stimulated tissue and electrode are limiting factors in miniaturization of this technology, as charge density increases with decreasing electrode size. In an attempt to find an equilibrium between these two opposing constraints (electrode size and charge density), the objective of this work was to develop a novel iridium-nickel oxide (Ir0.2-Ni0.8-oxide) coating that could intrinsically offer high charge storage capacity. Thermal decomposition was used to fabricate titanium oxide, iridium oxide, nickel oxide, and bimetallic iridium-nickel oxide coatings on titanium electrode substrates. The Ir0.2-Ni0.8-oxide coating yielded the highest intrinsic (material property) and extrinsic (material property + surface area) charge storage capacity (CSC) among the investigated materials, exceeding the performance of the current state-of-the-art neural stimulating electrode, Ir-oxide. This indicates that the Ir0.2-Ni0.8-oxide material is a promising alternative to currently used Ir-oxide, Pt, Au and carbon-based stimulating electrodes
A sustainable alternative to fossil fuels, cow dung is a renewable energy source that might considerably lower carbon emissions. By modifying its characteristics, such as its gross calorific value (GCV), it could be utilized as a flexible and effective fuel for both industrial and domestic use. To create a fuel composite with a higher heating value, this research examines the heating values and proximate analysis of local cow dung as well as the effects of blending it with agricultural waste. To provide the best heating value, the technique comprises infusing prepared agricultural biomass blends and cow dung at particular ratios. The composite’s quality was enhanced by increasing GCV from 3066 Kcal/kg to 3600 Kcal/kg, increasing volatile matter content, i.e., from 60% to 68%, as well as lowering the ash content of the resultant pellet from 19% to 11%, on average.