Department of Chemical Engineering

Indian Institute of Technology Hyderabad (IITH) is a premier institute of science and technology established in 2008. IITH has been consistently ranked in the&nbsp;<a href="https://iith.ac.in/reports/" rel="noopener noreferrer">top 10 institutes</a>&nbsp;in India for Engineering&nbsp;<a href="https://www.nirfindia.org/2021/EngineeringRanking.html" rel="noopener noreferrer" target="_blank">according to NIRF</a>&nbsp;making it one of the most coveted schools for science and technology in the country.

IITH offers&nbsp;<a href="https://iith.ac.in/academics/under-graduate/">undergraduate programs</a>&nbsp;in all the classical engineering disciplines, applied sciences, design, as well as several modern interdisciplinary areas. Students are given a flexibility to explore a broad set of areas, and potentially pursue a minor or double major in a discipline that is not their own. Students who wish to seek a deeper understanding of their own discipline are strongly encouraged to get involved in cutting-edge research with the help of a faculty to mentor them, and earn an Honors in their own field.

The very foundation of IIT Hyderabad is based on&nbsp;<a href="https://iith.ac.in/research/">research and innovation</a>. The vibrant research culture is evident from the number of patents and publications that IITH produces consistently every year. IITH offers&nbsp;<a href="https://iith.ac.in/academics/programmes-offered/">graduate programs</a>&nbsp;at both a masters, and a doctoral level, in several diverse areas. There are separate programs for technology, design, science, and liberal arts. The&nbsp;<a href="https://iith.ac.in/academics/post-graduate/">MTech program</a>&nbsp;is offered in various modes and durations to cater to the ever-growing need of postgraduate level professionals in the country.

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IITH enjoys a very special relationship with Japanese universities and industries that goes beyond academic and research collaborations. In fact, some of the iconic buildings in IITH campus will carry the signature of Japanese architecture.

IITH creates a unique holistic ecosystem for education that offers interactive learning, a very flexible academic structure, cutting-edge research, strong industry collaboration, and entrepreneurship. This is an environment which enables students and faculty to translate their dreams into realities.

IIT Hyderabad

Oral administration of Amphotericin B (AmB) is abstained due to its poor bioavailability and high toxicity. Current intravenous lipid formulations are delivered as 3−5 mg AmB/kg of body weight, due to its dose dependent nephrotoxicity. In this work, we engineer the electrospun gelatin nanofibers to enable their use for controlled release of AmB in the form of oral tablets while focusing on loading realistic drug doses of AmB as per the clinical guidelines for the treatment of Visceral Leishmaniasis. A detailed study is carried out to understand the effect of different crosslinking strategies, drug concentrations, compressive loading (to form tablets) and additional protective layer of sodium alginate on release kinetics. Based on the outcome of these studies, we developed a systematic protocol to achieve the controlled release and minimizing the frequency of dosing in order to attain less toxicity at realistic body pH condition. The swelling and enzymatic degradation studies further infer the realistic stability of the tablet and its correlation with the in-vitro release kinetics of drug. © 2020 Elsevier Ltd

World University root node

Materials Today Communications

Gelatin nanofiber assisted zero order release of Amphotericin-B: A study with realistic drug loading for oral formulation

We present an analysis of the microfluidic Dean flow fractionation (DFF) method in low aspect-ratio spiral chip for high concentrations (&gt; 106 particles /mL) of sub-micron (1-3 μm) particles. We systematically analyze the particle stream profile (i.e. thickness and distance from the channel wall) as a function of downstream channel length for step-wise increase in the fluid velocity and the flow rate ratio (FRR) of the particles to the sheath fluid. © 2020 CBMS-0001

MicroTAS 2020 - 24th International Conference on Miniaturized Systems for Chemistry and Life Sciences

Effect of dean flows on sub-micron particles in low aspect ratio microchannels - analysis of dff

This work mainly aims on the investigation of phase hold-up characteristics in a column flotation at different feed solid concentrations performing for an extensive range of working conditions. Phase hold-ups are measured using the electrical resistance tomography (ERT) coupled with pressure transducers technique. Experiments are conducted for two different nature mineral particles: hydrophilic (silica) and semi-hydrophobic (oxidized coal). The impact of gas superficial velocity, feed superficial velocity and pulp slurry height for a fixed sparger and frother addition on the gas and solid dispersion are studied. Gas hold-up increases with the gas flowrate and slurry feed rate, decreases with solid concentration. Further, bubble dynamics is estimated using coupled ERT with dynamic gas disengagement (DGD) approach. It is found that the solid’s presence affect the bubble swarm velocity thereby causing local gas holdup to drop. Possible mechanisms due to solid particles on gas dispersion are discussed and verified in the light of current experimental results. © 2020, The Indian Institute of Metals - IIM.

Transactions of the Indian Institute of Metals

Measurement of Gas–Solid Dispersion Characteristics in a Slurry Flotation Column Using ERT Technique

A lot of progress has been made in rechargeable lithium-ion battery (LIB) technology research in the last decade, even so, renewed developmental efforts must be pursued to better improve energy density, capacity retention and rate capability. This review discusses the role that one-dimensional (1D) nanomaterials can play towards development of next-generation LIBs. Electrode nanoengineering, interfacial kinetics and high-volume manufacturing are critical issues limiting energy density, electrochemical performance and material viability. These points are discussed, as are the advantages of deploying these nanomaterials in rechargeable LIB devices. Current data from literature is indicative of laboratory-scale success as these 1D nanomaterials display excellent capacity retention, high-rate capability and long cycle life emanating from high mechanical strength, resilience and short charge carrier diffusion distance. However, significant advances are required to translate these achievements into commercial scale deployment. © 2020 IOP Publishing Ltd.

Journal of Physics D: Applied Physics

One-dimensional nanomaterials in lithium-ion batteries

Competition for nutrients in a polymicrobial biofilm may lead to susceptible species being subjected to nutritional stress. The influence of bacterial growth rates and interspecies interactions on their susceptibility and response to nutritional stress is not well understood. Pseudomonas aeruginosa and Staphylococcus aureus are two prevalent causative pathogens that coexist in biofilm-associated infections. Despite being the slower-growing species, P. aeruginosa dominates in a two-species biofilm by inducing phenotypic switching of S. aureus to a metabolically-challenged small colony variant (SCV) via the release of 2-heptyl-4-hydroxyquinoline N-oxide (HQNO). We hypothesize that P. aeruginosa experiences nutritional stress in competition with S. aureus, and that the release of HQNO is an adaptive response to nutritional stress. We present an individual-based two-species biofilm model in which interactions between entities induce emergent properties. As the biofilm matured, the difference in growth rates of the two species caused a non-uniform distribution of nutrients leading to nutritional stress for P. aeruginosa and a concurrent increase in the proportion of S. aureus subpopulation. The latter resulted in increased release of autoinducer, and subsequently the upregulation of P. aeruginosa cells via quorum sensing. Upregulated P. aeruginosa cells released HQNO at enhanced rates, thereby inducing phenotypic switching of S. aureus to SCVs which consume nutrient at a reduced rate. This shifted the nutrient distribution back in favor of P. aeruginosa, thereby relieving nutritional stress. Increase in nutritional stress potentiated the transformation of S. aureus into SCVs. HQNO production decreased once nutritional stress was relieved, indicating that phenotypic switching acts as a regulatory stress-adaptive response. © 2020, Indian Academy of Sciences.

Fulltext

Journal of Biosciences

Quorum sensing-induced phenotypic switching as a regulatory nutritional stress response in a competitive two-species biofilm: An individual-based cellular automata model

An increasing demand for lithium-ion batteries with high energy storage and a high-power rating, to enable applications such as electric vehicles, demands electrode materials with large charge storage capability and faster kinetics. We demonstrate the synthesis and utilization of the hierarchical porous carbon structures derived from bacterial cellulose-polyaniline nanocomposites as a promising anode material for high-rate lithium-ion batteries. Microstructural analysis of the derived carbon revealed the inheritance of fibrous backbone from bacterial cellulose along with the nanogranular structure of polyaniline. The structural characterization of as-derived porous carbon structures is performed by XRD, Raman spectroscopy, and XPS, and the electrochemical properties are analyzed by cyclic voltammetry, galvanostatic charge-discharge studies, and impedance spectroscopy. These nitrogen-doped carbon structures unveiled high reversible capacities of 432, 276, and 127 mAh/g at a 1C, 5C, and 10C rate, respectively, with an excellent capacity retention. Furthermore, first principle calculations are performed which indicate that the presence of oxidized, pyrrolic, and pyridinic nitrogen in carbon significantly enhances the lithium adsorption (nearly double than that of pristine carbon). Therefore, the enhanced electrochemical performance may be attributed to the combined effect of nitrogen doping and interconnected micromeso porous (hierarchical) network present in the hard carbon anode material. Copyright © 2020 American Chemical Society.

Department of Materials Science and Metallurgical Engineering

ACS Applied Energy Materials

Bacterial Cellulose-Polyaniline Composite Derived Hierarchical Nitrogen-Doped Porous Carbon Nanofibers as Anode for High-Rate Lithium-Ion Batteries

Identification of polycyclic aromatic hydrocarbons (PAHs) sources in the environmental compartments is crucial, but there is a need for appropriate management and remediation plan in the environment. PAHs can provide useful information, because they have been utilized for source apportionment. In this study, priority 16 PAHs were determined in sediments from Yamuna River in Delhi for the assessment of their possible sources. Among 16 PAHs, the dominant compounds were fluoranthene, chrysene, fluorine, and pyrene, and their sum accounted for more than 96% of the total 16 priority PAHs. The concentrations of ∑16PAHs at locations between upstream and downstream were not showing any considerable spatial gradient. The concentration of seven probable carcinogenic PAHs ranged 236–6230 µg kg−1 with the mean value of 1897 ± 1740 µg kg−1, and accounted for 40% of the ∑16PAHs. Benzo(a)pyrene toxic equivalent factors (TEFs) used for the quantification of relative toxicity potential of priority PAHs in terms of BaP toxicity equivalency (BaPTEQ) were presented. Homolog profiles demonstrated the dominance of two-, three-, and four-ring PAHs. Composition profile and selected concentration ratios of PAHs were used as diagnostic tools for the identification of possible emission sources of PAHs. The study suggested the pyrogenic activities of petroleum, coal, and biomass combustions as a major source of PAH contamination in the river. However, marginally petrogenic sources from automobile workshops and accidental spillage cannot be ruled out. The observed levels of total PAHs and their toxicity equivalency in sediments were more or less comparable with similar studies carried out worldwide. © 2018, © 2018 Taylor & Francis Group, LLC.

Polycyclic Aromatic Compounds

Benzo(a)Pyrene Equivalency and Source Identification of Priority Polycyclic Aromatic Hydrocarbons in Surface Sediments from Yamuna River

The effect of viscosity on the behavior of a non-equilibrium bubble is investigated experimentally, in two scenarios; firstly, when the bubble is generated in the bulk of the fluid (termed as “free-field” bubble) and secondly when the bubble is generated near a free-surface (termed as “free-surface” bubble). The bubble is created using a low-voltage spark circuit and its dynamics is captured using a high-speed camera with backlit illumination. The viscosity of the surrounding fluid is varied by using different grades of silicone oil. For a “free-field” bubble, the bubble oscillates radially and as the viscosity of the liquid increases, the number of oscillations, as well as the time period of each oscillation, are increased. At high viscosities, the bubble also becomes stable and does not disintegrate into smaller bubbles. The volumetric oscillations also show good agreement with the Rayleigh-Plesset model incorporating energy loss and viscous effects. For “free-surface” bubbles, two parameters, namely, the initial distance of the bubble from the free-surface and the viscosity of the surrounding fluid are varied. It is observed that beyond a certain initial distance of the bubble from the free-surface, the bubble behaves as a “free-field” bubble with negligible influence of the free-surface on its dynamics. This limiting initial distance decreases as the liquid viscosity is increased and is not dependent on the bubble radius. For these bubbles, different behaviors of the free-surface in each liquid are also presented for distances up to the limiting initial distance. These free-surface behaviors are classified into four different regions on a plot of the Reynolds number (based on the bubble expansion) versus the non-dimensional distance of the bubble from the free-surface. © 2020 Elsevier Inc.

Department of Mechanical and Aerospace Engineering

Experimental Thermal and Fluid Science

Effect of viscosity on the volumetric oscillations of a non-equilibrium bubble in free-field and near a free-surface

A twin-fluid pneumatic injector system with coaxial liquid and air streams mixed slightly upstream of the outlet, is studied in a cross-flow arrangement to understand its working principle. The gap between the orifice and the liquid tube, where the air and liquid cross-flow occurs, is known to determine the modes of working of the atomizer for the given operating flow rates of air and liquid. The two distinct modes, namely the flow focusing (FF) and flow blurring (FB) are observed in the present study, and the transition from FF to FB mode is explored using optical visualization. The characteristics of the internal two-phase flow mixing that occurs due to backflow recirculation in FB mode are also investigated by performing large eddy simulation (LES) using the volume of fluid (VoF) approach. The results of the numerical simulation are validated with experimental observations for the length of backflow recirculation observed in the liquid tube. The present study demonstrates the development of multiple microjets, which explains experimental observations of the lack of core jet and the almost uniform distribution of radial Sauter mean diameter (SMD) reported in the literature. The high-resolution backlit image of a scaled-up transparent injector with a 6 mm orifice diameter validates the numerical results that describe the internal two-phase flow. © 2020 Elsevier Masson SAS

European Journal of Mechanics, B/Fluids

A combined experimental and computational study of flow-blurring atomization in a twin-fluid atomizer

Global energy crisis escalates the emphasis on ways to find green and sustainable solutions. Photoelectrochemical (PEC) conversion is one of the key technologies to fulfill the energy demand by converting solar energy into chemical fuels. Binary copper oxides suffer from severe photocorrosion and ternary copper oxides such as copper bismuth oxide (CuBi2O4) exhibit poor charge separation and transfer. In this work, a composite consisting of CuO annealed at 450 °C and CBO electrodeposited for 5 min on top of it (CuO-450/CBO-5) showed the best performance with a positive shift of 0.2 V in onset potential, a high current density of −0.9 mA cm−2 at 0.1 V vs RHE and high stability over pure CuO. The systematic deposition of CBO on CuO leads to intimate contact between the two semiconductors wherein, CuO acts as a hole carrier and CBO accommodates the hydrogen evolution reaction (HER). © 2020 Elsevier Inc.