The glass transition and crystallization kinetic studies on BaNaB9O15 glasses

Transparent glasses of BaNaB9O15 (BNBO) were fabricated via the conventional melt-quenching technique. The amorphous and the glassy nature of the as-quenched samples were respectively, confirmed by X-ray powder diffraction (XRD) and differential scanning calorimetry (DSC). The glass transition and crystallization parameters were evaluated under non-isothermal conditions using DSC. The correlation between the heating rate dependent glass transition and the crystallization temperatures was discussed and deduced the Kauzmann temperature for BNBO glass-plates and powdered samples. The values of the Kauzmann temperature for the plates and powdered samples were 776 K and 768 K, respectively. Approximation-free method was used to evaluate the crystallization kinetic parameters for the BNBO glass samples. The effect of the sample thickness on the crystallization kinetics of BNBO glasses was also investigated.Comment: 23 pages, 12 figure

Melting behaviour of sponge iron in induction furnace

Sponge iron with its consistency of composition, lower content of tramp elements and particularly low phosphorus and of sulphur has drawn the attention of medium/large scale foundries for producing quality steel castings. It is one of the alternative charge materials to scrap in induction furnaces. National Metallurgical Laboratory has made an attempt to melt sponge iron in induction furnaces and optimize its melting behavour. It is possible to use continuous charging arrangements for melting of 100% sponge iron in induction furnace

Environmental Management for Sustainable Growth in an Integrated Iron and Steel Plant

The manufacture of steel involves a large number of processing which lead to complex problems of environme-ntal pollution. Coke making and sintering are two of the major areas in so far as pollution is concerned. Slag constitutes the major portion of solid wastes. Waste generation adversely affects productivity and contributes to the high cost of production. It has been shown that improving the efficiency of operation and fuel saving measures help in reducing pollution in steel plants. Utilization of slag, mill scale, sludge and dusts, safe disposal of hazardous wastes and minimization of emissions of CO, C02, 502, NOx, cyanides, volatile organic compounds (VOC), NH3, suspended particulate matters (SPM) etc, are essential steps towards environmental management

Emotional voice processing: Investigating the role of genetic variation in the serotonin transporter across development

The ability to effectively respond to emotional information carried in the human voice plays a pivotal role for social interactions. We examined how genetic factors, especially the serotonin transporter genetic variation (5-HTTLPR), affect the neurodynamics of emotional voice processing in infants and adults by measuring event-related brain potentials (ERPs). The results revealed that infants distinguish between emotions during an early perceptual processing stage, whereas adults recognize and evaluate the meaning of emotions during later semantic processing stages. While infants do discriminate between emotions, only in adults was genetic variation associated with neurophysiological differences in how positive and negative emotions are processed in the brain. This suggests that genetic association with neurocognitive functions emerges during development, emphasizing the role that variation in serotonin plays in the maturation of brain systems involved in emotion recognition

Exploring employment opportunities through microtasks via cybercafes

Microwork in cybercafés is a promising tool for poverty alleviation. For those who cannot afford a computer, cybercafés can serve as a simple payment channel and as a platform to work. However, there are questions about whether workers are interested in working in cybercafés, whether cybercafé owners are willing to host such a set up, and whether workers are skilled enough to earn an acceptable pay rate? We designed experiments in internet/cyber cafes in India and Kenya to investigate these issues. We also investigated whether computers make workers more productive than mobile platforms? In surveys, we found that 99% of the users wanted to continue with the experiment in cybercafé, while 8 of 9 cybercafé owners showed interest to host this experiment. User typing speed was adequate to earn a pay rate comparable to their existing wages, and the fastest workers were approximately twice as productive usi

Magnetite ore of nagaland—its mineralogy and reduction kinetics

The magnetite body near Pokphur in the Kiphere district of Nagaland is geologically quite different and a rare type of occurrence associated with ophiolite. Mineralogical studies reveal the presence of magnetite, chromite and hematite followed by goethite, ilmentite, trevorite, pentlandite and millerrite. Magnetite grains are weathered to various degrees and sometimes fractured. Reduction studies indicate that in gas-solid system considerable reduction of magnetite ore takes place in initial 60 minutes, further the rate of reduction becomes slow. In gas-solid system the percentage reduction of magnetite ore is considerably more compared to solid-solid systems

Expressing Biologically Active Membrane Proteins in a Cell-Free Transcription-Translation Platform

Cell-free transcription-translation platforms have been widely utilized to express soluble proteins in basic synthetic biological circuit prototyping. From a synthetic biology point of view, it is critical to express membrane proteins in cell-free transcription-translation systems, and use them directly in biocircuits, considering the fact that histidine kinases, G-protein coupled receptors (GPCRs) and other important biosensors are all membrane proteins. Previous studies have expressed membrane proteins in cell-free systems with the help of detergents, liposomes or nanodiscs, but have not demonstrated the ability to prototype circuit behavior for the purpose of testing more complex circuit functions involving membrane-bound proteins. Built on previous efforts, in this work we demonstrated that we could co-translationally express solubilized and active membrane proteins in our cell-free TX-TL platform with membrane-like materials. We first tested the expression of several constructs with β1 and β2 adrenergic receptors in TX-TL and observed significant insoluble membrane protein production. The addition of nanodiscs to the cell free expression system enabled solubilization of membrane proteins. Nanodisc is lipoprotein- based membrane-like material. The activity of β2 adrenergic receptor was tested with both fluorescence and Surface Plasmon Resonance (SPR) binding assays by monitoring the specific binding response of small-molecule binders, carazolol and norepinephrine. Our results suggest that it is promising to use cell-free expression systems to prototype synthetic biocircuits involving single chain membrane proteins without extra procedures. This data made us one step closer to testing complex membrane protein circuits in cell-free environment

Help Supporters: Exploring the Design Space of Assistive Technologies to Support Face-to-Face Help Between Blind and Sighted Strangers

Blind and low-vision (BLV) people face many challenges when venturing into public environments, often wishing it were easier to get help from people nearby. Ironically, while many sighted individuals are willing to help, such interactions are infrequent. Asking for help is socially awkward for BLV people, and sighted people lack experience in helping BLV people. Through a mixed-ability research-through-design process, we explore four diverse approaches toward how assistive technology can serve as help supporters that collaborate with both BLV and sighted parties throughout the help process. These approaches span two phases: the connection phase (finding someone to help) and the collaboration phase (facilitating help after finding someone). Our findings from a 20-participant mixed-ability study reveal how help supporters can best facilitate connection, which types of information they should present during both phases, and more. We discuss design implications for future approaches to support face-to-face help.Comment: To Appear In Proceedings of the 2024 CHI Conference on Human Factors in Computing Systems (Honolulu, HI, USA) Association for Computing Machinery, New York, NY, USA. 24 page

Negative Poisson’s ratio polyethylene matrix and 0.5BaCa0.8Zr0.2O3-0.5Ba0.7Ca0.3TiO3 based piezocomposite for sensing and energy harvesting applications

Abstract Finite element studies were conducted on 0.5Ba(Zr0.2 Ti0.8) O3–0.5(Ba0.7 Ca0.3)TiO3 (BCZT) piezoelectric particles embedded in polyethylene matrix to create a piezocomposite having a positive and negative Poisson's ratio of −0.32 and 0.2. Polyethylene with a positive Poisson's ratio is referred to as non-auxetic while those with negative Poisson's ratio are referred to as auxetic or inherently auxetic. The effective elastic and piezoelectric properties were calculated at volume fractions of (4%, 8% to 24%) to study their sensing and harvesting performance. This study compared lead-free auxetic 0–3 piezocomposite for sensing and energy harvesting with non-auxetic one. Inherently auxetic piezocomposites have been studied for their elastic and piezoelectric properties and improved mechanical coupling, but their sensing and energy harvesting capabilities and behavior patterns have not been explored in previous literatures. The effect of Poisson's ratio ranging between −0.9 to 0.4 on the sensing and energy harvesting performance of an inherently auxetic lead free piezocomposite composite with BCZT inclusions has also not been studied before, motivating the author to conduct the present study. Auxetic piezocomposite demonstrated an overall improvement in performance in terms of higher sensing voltage and harvested power. The study was repeated at a constant volume fraction of 24% for a range of Poisson's ratio varied between −0.9 to 0.4. Enhanced performance was observed at the extreme negative end of the Poisson's ratio spectrum. This paper demonstrates the potential improvements by exploiting auxetic matrices in future piezocomposite sensors and energy harvesters

Iron making in ancient India - a critical assessment

It is a well known fact, that Indian craftsman produced quality iron products much earlier than the developed countries, making use of local reserves of iron ore. Iron produced in ancient India was mostly wrought iron. The metal was obtained in the form of a pasty mass and then shaped under hammer. Today, when India is producing several million tons of iron, primitive iron making is still exists in some parts of India. The primitive iron making furnaces declined in numbers gradually from about 500 in the beginning of 20'h century to about 150 by the middle of the century. Their present number is not known. Such furnaces are in operation deep into the forests and the tribal areas of India. The paper discusses briefly the history of iron making along with the critical assessment of the ancient processes. Some of the important measures absolutely. essential to upgrade the processes have also been discussed. Several pertinent modifications have been proposed in the design of these furnaces to make them more energy efficient and economically viable 'for tribal and rural populace