Recent advances in indium metallurgy: A review

The by-products of zinc refineries are used as the primary mineral resources for the commercial production of indium. The discarded LCDs containing adequate amount of indium is rather worth as its secondary resources compared to the by-products of zinc refineries. Mining and recycling rates of indium, respectively from minerals and waste LCDs are in progress to meet its huge demand. Recycling of the LCDs has been dominating over mining, as presently 480t of indium are produced annually from mining, however, that of 650t annually from recycling. Different aspects of the extractive metallurgy of indium are summarized in this review paper.     

Mechanistic study of Al electrodeposition from EMIC–AlCl3 and BMIC–AlCl3 electrolytes at low temperature

Aluminum was electrodeposited from two different ionic liquid electrolytes namely; 1-ethyl-3-methylimidazolicum chloride and AlCl₃ (EMIC–AlCl₃) and 1-butyl-3-methylimidazolium chloride (BMIC–AlCl₃) at 90 ± 2 °C. Nodular morphology of aluminum was obtained at the copper substrate. To evaluate the reaction mechanism, chronoamperometric study was adopted. From the chronoamperometric analysis, it was observed that the reaction was controlled by instantaneous three-dimensional diffusion process. The diffusion coefficient (D) of Al₂C₇⁻ was found to be 5.2–6.6 × 10⁻¹¹ m² s⁻¹ and 2.2 × 10⁻¹¹ m² s⁻¹ for EMIC–AlCl₃ and BMIC–AlCl₃ ionic liquid electrolytes, respectively. The nuclei density of electrodeposited aluminum on the copper was also confirmed by scanning electron microscope wherein uniformly distributed aluminum nodules were observed.     

Effect of the compatibilizer,on the engineering properties of TPV based on Hypalon® and PP prepared by dynamic vulcanization

Elastomeric Chlorosulfonated polyethylene (Hypalon^®) and thermoplastic Polypropylene (PP) based thermoplastic vulcanizates (TPVs) were prepared in presence of different doses of compatibilizer, maleic anhydride grafted PP (PP‐g‐MA) by employing dynamic vulcanization technique. The effect of incorporation in different proportions of compatibilizer on mechanical, spectral, morphological, thermal, and rheological properties of such TPVs was studied and the same were compared to that of virgin PP and amongst themselves. The mechanical analysis of the prepared TPVs exhibited significant improvements in stress at 25% modulus, ultimate tensile strength (UTS), and hardness values. FTIR studies revealed that a chemical interaction had taken place between Hypalon^® and functionalized compatibilizer during the process of dynamic vulcanization which led to an enhancement of interfacial adhesion between them. The two‐phase morphologies were clearly observed by scanning electron microscopic studies. The T_g values of Hypalon^® was modified in the TPVs as exhibited by differential scanning calorimetric studies. TGA studies indicated the increase in thermal stability of all TPVs with respect to the elastomeric Hypalon^®. Rheological properties showed that the compatibilizer reduces the melt viscosity of TPVs and thus facilitates the processibility of such TPVs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40312.     

Using light to control the interactions between self-rotating assemblies of active gels

Polymer gels undergoing the oscillating Belousov-Zhabotinsky (BZ) reaction exhibit an autonomous, periodic swelling and deswelling, where the mechanical oscillations are driven by the chemical reaction within the polymer network. Using computer simulations, we show that these BZ gels can undergo a form of auto-chemotaxis, enabling the gels to spontaneously move in response to self-generated chemical gradients. Focusing on four millimeter-sized pieces of these BZ gels, we show that the pieces can organize into self-rotating clusters that resemble a moving pinwheel or gear. By analyzing the factors that promote the formation of a single self-rotating cluster, we attempt to design systems of multiple, interacting gears. We show that light, which suppresses the oscillations of the gels, can be harnessed to promote the formation of two self-rotating clusters. These studies point to a novel form of photo-chemo-mechanical transduction, where light is utilized to control the conversion of chemical and mechanical energy in the system. Moreover, the interaction between the BZ gel gears reveals a new form of entrainment between these moving units. Namely, their coordinated motion is achieved through chemical coupling or communication, rather than a mechanical coupling. These findings can lead to the formation of chemically “communicating” devices that can be programmed to perform autonomous work through the use of light.     

The effect of alkalization and fiber loading on the mechanical properties of bamboo fiber composites,Part 1: — Polyester resin matrix

Bamboo strips [10 cm × 1.5 cm × (1?1.5) mm] were treated with caustic solutions for 1 h at different concentrations e.g., 0, 10, 15, 20, and 25%. Bamboo strips reinforced polyester resin composites were fabricated by hand‐lay‐up technique using both alkali‐treated and untreated bamboo strips, using a room temperature curing system for the polyester resin. This study aims at the evaluation of the influence of caustic concentration on the mechanical properties of bamboo strips reinforced polyester resin composites at a constant 50% loading of reinforcement. Maximum improvement in property was achieved possibly with 20% of caustic treated strip reinforcements. Beyond 20%, there was degradation in all the strength properties because of failure in mechanical properties of the reinforcements itself. The effect of fiber loading variation upon mechanical properties was also studied. It was observed that superior mechanical properties were obtained with 60% filler loading. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Improved energy recovery from dark fermented cane molasses using microbial fuel cells

A major limitation associated with fermentative hydrogen production is the low substrate conversion efficiency. This limitation can be overcome by integrating the process with a microbial fuel cell (MFC) which converts the residual energy of the substrate to electricity. Studies were carried out to check the feasibility of this integration. Biohydrogen was produced from the fermentation of cane molasses in both batch and continuous modes. A maximum yield of about 8.23 mol H₂/kg COD_removed was observed in the batch process compared to 11.6 mol H₂/kg COD_removed in the continuous process. The spent fermentation media was then used as a substrate in an MFC for electricity generation. The MFC parameters such as the initial anolyte pH, the substrate concentration and the effect of pre-treatment were studied and optimized to maximize coulombic efficiency. Reductions in COD and total carbohydrates were about 85% and 88% respectively. A power output of 3.02 W/m³ was obtained with an anolyte pH of 7.5 using alkali pre-treated spent media. The results show that integrating a MFC with dark fermentation is a promising way to utilize the substrate energy.     

Biomolecular Template-Induced Biomimetic Coating of Hydroxyapatite on an SS 316 L Substrate

Bone, a natural composite, comprises non-stoichiometric calcium hydroxyapatite (HAp) precipitated in a controlled reaction environment of a highly aligned, anisotropic organic template (type I collagen) that leads to its exotic tensile and compressive strength. It differs from stoichiometric hydroxyapatite in composition, crystallinity, and other physical and mechanical properties. In the present study, functionalized biomolecular template-induced precipitation of HAp on an SS 316 L substrate following biomimetic route exhibits distinct alterations in crystal growth and geometry, which in turn indicates the potential of the process to develop a non-stoichiometric HAp coating on metal implants.     

Adsorption and penetration of hydrogen in W: A first principles study

In BCC crystals, such as Tungsten (W), slippage has been observed on the (1 1 0) and (1 1 2) planes. In this work, hydrogen diffusion paths from three different W surfaces ((1 0 0), (1 1 0) and (1 1 2)) have been calculated using first principles density functional theory. Equilibrium sites for H at the surfaces are identified. The energetics for H penetration from the surfaces to the solute site in the bulk is calculated. It is found that for our low surface coverage of H (3.4 × 10¹⁴ H/cm²), approximately 2 eV is required for an H atom to penetrate any of the W surfaces considered in this study.     

Social conflicts and their remedies in the distribution of canal water: Case study of the Damodar valley irrigation project,India

Lower availability of water in canals has caused damage of control structures, breach of minors and sub‐minors and erection of cross bunds to obtain water for crops. This misappropriation has resulted in inter‐ and intra‐village conflicts in the area of the Damodar Valley Irrigation Project in West Bengal. The conflicts are mostly caste based, as is prevalent in Northern India, and subject to political involvement. In the head reach the conflicts over the distribution of water are solved by the intervention of village‐level institutions with the help of community development blocks and irrigation officials. But in the tail reach the village‐level institutions and government officials have played a very limited role in resolving the conflicts. This article examines the nature and causes of the conflicts and some solutions are suggested.