Raghunathan Rengaswamy's research while affiliated with Indian Institute of Technology Madras and other places

Publications (280)

Article
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The onset of colorectal cancer (CRC) is often attributed to gut bacterial dysbiosis, and thus gut microbiota are highly relevant in devising treatment strategies. Certain gut microbes, like Enterococcus spp ., exhibit remarkable anti-neoplastic and probiotic properties, which can aid in silver nanoparticle (AgNPs) induced reactive oxygen species (R...
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The conversion of nuclear energy into electricity is facilitated by chemical intermediates and molecular products formed during the radiolysis of water. In this work, we hypothesize a novel radiolytic charging approach for redox flow battery electrolytes. Radiolytically produced ionic intermediates and molecular products oxidize or reduce the metal...
Article
Ambient air quality shows a high degree of spatiotemporal variation. It is known to impact human life and health. Obtaining meaningful estimates of human exposure to air pollutants is key to mitigating its ill effects. In order to ascertain individual exposure, pollutant information is required at high resolution. Current air quality monitoring app...
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The progression of tumorigenesis starts with a few mutational and structural driver events in the cell. Various cohort-based computational tools exist to identify driver genes but require multiple samples to identify less frequently mutated driver genes. Many studies use different methods to identify driver mutations/genes from mutations that have...
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Model building and parameter estimation are traditional concepts widely used in chemical, biological, metallurgical and manufacturing industries. Early modelling methodologies focused on mathematically capturing the process knowledge and domain expertise of the modeler. The models thus developed are termed first principles models (or white‐box mode...
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Droplet microfluidics provides a platform for realizing programmable and flexible devices for performing diverse process operations on a single chip. Although recent developments have incorporated basic functionalities in droplet-based devices such as droplet sorting, sequencing, synchronization, etc., the design of microfluidic networks for specif...
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Introduction The integrity of the intestinal epithelium is crucial for human health and is harmed in autism spectrum disorder (ASD). An aberrant gut microbial composition resulting in gut-derived metabolic toxins was found to damage the intestinal epithelium, jeopardizing tissue integrity. These toxins further reach the brain via the gut-brain axis...
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The ability to manipulate drops is essential for integrating multiple processes in droplet microfluidics‐based lab‐on‐a‐chip devices. Examples of such droplet manipulation operations include sorting, sequencing, synchronization, etc. Microfluidic networks are promising platforms for performing these functionalities. This work explores the design of...
Article
Neural networks with ReLU activation function have been shown to be universal function approximators and learn function mapping as non-smooth functions. Recently, there is considerable interest in the use of neural networks in applications such as optimal control. It is well-known that optimization involving non-convex, non-smooth functions are com...
Preprint
Full-text available
The progression of tumorigenesis starts with a few mutational and structural driver events in the cell. Various cohort-based computational tools exist to identify driver genes but require a large number of samples to produce reliable results. Many studies use different methods to identify driver mutations/genes from mutations that have no impact on...
Article
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An emergent area of cancer genomics is the identification of driver genes. Driver genes confer a selective growth advantage to the cell. While several driver genes have been discovered, many remain undiscovered, especially those mutated at a low frequency across samples. This study defines new features and builds a pan-cancer model, cTaG, to identi...
Chapter
Materials design for functional applications carried out using conventional trial and error methodologies is expensive and time consuming. Machine learning techniques can be used to design materials suitable for functional applications and discover materials for specific applications from existing literature. This study demonstrates a machine learn...
Preprint
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Genetic circuit design is a well-studied problem in synthetic biology. Ever since the first genetic circuits -- the repressilator and the toggle switch -- were designed and implemented, many advances have been made in this area of research. The current review systematically organizes a number of key works in this domain by employing the versatile f...
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Cylindrical polymer electrolyte membrane fuel cells are promising energy conversion devices for next generation transportation applications because of their high volumetric and gravimetric power densities. The present study is focused to evaluate the effect of a design parameter (clamping pressure) and an operational parameter (gas pressure) on the...
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Background: The prevalence of preterm birth (PTB) is high in lower and middle-income countries (LMIC) such as India. In LMIC, since a large proportion seeks antenatal care for the first time beyond 14-weeks of pregnancy, accurate estimation of gestational age (GA) using measures derived from ultrasonography scans in the second and third trimesters...
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Electrochemical energy, being a safe and clean renewable energy source, is gaining considerable attention in recent years. The electrochemical energy technologies available are numerous and the choice of technology is usually guided by heuristics. The paper presents a critical review and comparison of three competing electrochemical energy technolo...
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Background: Different formulae have been developed globally to estimate gestational age (GA) by ultrasonography in the first trimester of pregnancy. In this study, we develop an Indian population-specific dating formula and compare its performance with published formulae. Finally, we evaluate the implications of the choice of dating method on pret...
Preprint
Neural networks with ReLU activation function have been shown to be universal function approximators and learn function mapping as non-smooth functions. Recently, there is considerable interest in the use of neural networks in applications such as optimal control. It is well-known that optimization involving non-convex, non-smooth functions are com...
Chapter
Li-ion batteries are a popular choice of rechargeable battery for use in many applications like portable electronics, automobiles as well as stationary applications for providing uninterruptable power supply. State of Charge (SoC) and State of Health (SoH) are important metrics of a Li-ion battery that can help in both battery prognostics and diagn...
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Frequency response analysis (FRA) of systems is a well-researched area. For years, FRA has been performed using input signals, which are a series of sinusoids or a sum of sinusoids. This results in large experimentation time, particularly when the system has to be probed at lower frequencies. In this work, we describe a previously unknown time-freq...
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Reliability based criteria are quite popular for optimal sensor network design. We present a modified definition of system reliability for sensor network design for two applications: reliable estimation of variables in a steady state linear flow process, and reliable fault detection and diagnosis for any process. Unlike the weakest-link based defin...
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In part I of this series of articles, the concept of overall system reliability was presented for two applications: reliable estimation of variables for steady state linear flow processes, and reliable fault detection and diagnosis for any process. In this part, systematic generation of the proposed system-wide reliability expression is discussed....
Preprint
Frequency response analysis (FRA) of systems is a well-researched area. Frequency response of electrochemical systems are identified using the electrochemical impedance spectroscopy (EIS) technique. EIS is unarguably the most used technique for diagnostic applications in several electrochemical systems that have relevance in renewable energy, corro...
Preprint
Model identification is a crucial problem in chemical industries. In recent years, there has been increasing interest in learning data-driven models utilizing partial knowledge about the system of interest. Most techniques for model identification do not provide the freedom to incorporate any partial information such as the structure of the model....
Article
Micro photosynthetic power cell (µPSC) is an electrochemical device that generates electricity by harnessing electrons and protons from the electron transport chains of photosynthesis (in the presence of light), and respiration (in the absence of light). µPSC is a potential power source for low and ultra-low power applications. The electron transpo...
Preprint
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An emergent area of cancer genomics has been the identification of driver genes. Driver genes confer a selective growth advantage to the cell and push it towards tumorigenesis. Functionally, driver genes can be divided into two categories, tumour suppressor genes (TSGs) and oncogenes (OGs), which have distinct mutation type profiles. While several...
Chapter
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The limited availability of conventional energy carriers has increased the demand for renewable energy sources to cater to the ever increasing energy demand. The present chapter focusses on phosphoric acid fuel cells (PAFCs) detailing their working principles and application potential. The different materials used in PAFCs, including electrolyte, c...
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Please use the following link for free access to the article pdf: https://authors.elsevier.com/c/1ajt8_8CLQ56jA
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Interfacial contact resistance in fuel cells is one of the primary challenges that needs to be overcome in the commercialization of fuel cells. This paper summarizes the governing parameters of the resistance such as surface morphology, contact pressure at the interface, electrical conductivities and corrosion resistance of gas diffusion layer and...
Article
Proton exchange membrane (PEM) fuel cells are attractive because of advantages such as low-temperature operation, no emission of harmful gases and high efficiency. However, the bipolar plates used in the state-of-the-art planar architecture are costly and increase the dead weight of the cell. In addition, the flow channels in the planar fuel cell i...
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Droplets, as they flow inside a microchannel, interact hydrodynamically to result in spatio-temporal patterns. The nature of the interaction decides the type of collective behaviour observed. In this context, we study the application of droplet microfluidics in the area of complex-shaped particle synthesis. We show how the dynamics of droplet motio...
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Colorectal cancer (CRC) is the fourth leading cause of mortality, world-wide. Gut bacterial dysbiosis being one of the major causes of CRC onset. Gut microbiota produced metabolites, e.g. folate and butyrate play crucial roles in cancer progression and treatment, and thus, need to be considered for effective CRC management. A potential cancer thera...
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Oscillation is a phenomenon very commonly observed in systems, ranging from simple ones to complex distributed network. Several techniques have been proposed in the literature for detecting oscillations to study their importance in domains ranging from physiology to climate studies. However, there is a lack of a common framework accommodative of im...
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Model predictive controllers (MPC) utilize a model of the process to optimize the future trajectory using an objective function to obtain a control move plan. Any new MPC implementation requires model identification. The quality of the identified model depends on the information content of the data. Performing step tests to obtain informative data...
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In this work, we provide a cost comparison of micro-photosynthetic power cells (µPSC) with the well-established photovoltaic (PV) cells for ultra-low power and low power applications. We also suggest avenues for the performance improvement of µPSC. To perform cost comparison, we considered two case studies, which are development of energy systems f...
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Reactive oxygen species (ROS) are primary effectors of cytotoxicity induced by many anti-cancer drugs. Rhythms in the pseudo-steady-state (PSS) levels of particular intracellular ROS in cancer cells and their relevance to drug effectiveness are unknown thus far. We report that the PSS levels of intracellular superoxide (SOX), an important ROS, exhi...
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Prediction of drug solubility is a crucial problem in pharmaceutical industries for both drug delivery and discovery purposes. Several theoretical approaches have been proposed to predict drug solubility in mixed solvent systems when the solubility values in pure solvents are known. Quantitative structure property relationship (QSPR) approaches are...
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Clustering of data into multiple models for real time applications is an interesting and important problem. This is usually referred to as the multiple model learning (MML) problem. This MML problem has been investigated for several engineering systems. Various non-parametric algorithms have been proposed in literature to identify multiple models u...
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Micro-photosynthetic power cell (μPSC) is one of the emerging energy harvesting technologies which harvests energy using light (photosynthesis) and carbohydrate metabolism in dark (respiration) for low-power (mW range) applications. μPSC is a green technology that not only uses solar power and algae, but also provides power in both dark and light c...
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A 2D droplet assembly can undergo destabilization through a series of coalescence events that propagate like an avalanche. Multiple avalanches can get triggered during the course of an experiment, which interact as they propagate in the system. In this article, we investigate the avalanching phenomenon as a function of the number of avalanches trig...
Preprint
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Autism spectrum disorder (ASD) refers to the set of complex neurological disorders characterized by repetitive behaviour. The reported occurrence of abnormal gut bacteria, along with prevalence of gastrointestinal disorders in ASD indicate its strong correlation with the gut microflora. Our study aims to understand the role of diet and gut bacteria...
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State estimation is a widely adopted soft sensing technique that incorporates predictions from an accurate model of the process and measurements to provide reliable estimates of unmeasured variables. The reliability of such estimators is threatened by measurement related challenges and model inaccuracies. In this article, a method for benchmarking...
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Humidity regulation in fuel cells utilizing bulk mass transfer and membrane-based methodologies have drawbacks and limitations, which are undesirable during fuel cell operation. In this work, we demonstrate a rapid and nearly accurate humidity control by mixing of dry and humidified gas streams for tracking predefined relative humidity set points....
Article
In power networks, where multiple fuel cell stacks are employed in a series-parallel configuration to deliver the required power, optimal sharing of the power demand between different stacks is an important problem. This is because the total current collectively produced by all the stacks is directly proportional to the fuel utilization, through st...
Article
Solar heat collection efficiency reduces with increase in temperature of the heating media owing to heat loss. Thermal energy capture is easily carried out using heat exchangers, but there are challenges in converting this to usable power, especially at lower temperatures. An electrochemical system which has reasonable variation in free energy with...
Article
PEM Fuel Cells (PEMFC) are attractive because of advantages such as low-temperature operation, no emission of harmful gases and high efficiency. However, the bipolar plates used in the state of the art planar architecture is costly and increases the dead weight of the cell. In addition, the flow channels in the planar fuel cell lead to difficulty i...
Article
Water Distribution Networks (WDNs) are vulnerable to accidental or deliberate contamination. Such contamination can be detected and identified by deploying a network of sensors. If the sensor network detects the presence of a contaminant, it is also very important to take corrective response actions to minimize the effects of contamination on the p...
Article
Micro-photosynthetic power cells (µPSCs) are a class of renewable energy harvesting devices that are gaining popularity in recent years. µPSCs generate electricity by harnessing the electrons and protons from the electron transport chains of photosynthesis and respiration in oxygenic photosynthetic organisms. µPSCs were first introduced as a potent...
Article
Energy storage (batteries) and conversion devices (fuel cells) operate based on electrochemical principles. Electrochemical impedance spectroscopy (EIS) is an important experimental technique that can be used to optimize the performance of these devices at the design stage. Further, EIS can also be used for non-invasive, in-situ diagnostics of devi...
Article
Ineffective water management in proton exchange membrane fuel cells (PEMFCs) can cause performance degradation. A simple mathematical model capturing the effect of water on the overall performance of the fuel cell system is of immense use in developing tools for water management. In this work, a computationally efficient first principles dynamic mo...
Article
A two-dimensional concentrated emulsion exhibits spontaneous rapid destabilization through an avalanche of coalescence events which propagate through the assembly stochastically. We propose a deterministic model to explain the average dynamics of the avalanching process. The dynamics of the avalanche phenomenon is studied as a function of a composi...
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Systematic scaling analysis of model equations can be valuable as a tool for developing computationally tractable simulations of physical systems. The scaling analysis methods in literature pose difficulties in the calculation of scale and reference values, when nonlinear terms are involved in the model equations. Further, existing methods involve...
Article
In this paper, we describe a model for a micro photosynthetic power cell (μPSC). μPSC is an electrochemical device which harnesses electrons and protons from the electron transport chains of photosynthesis (in the presence of light), and respiration (in the absence of light) occurring inside an oxygenic photosynthetic organism to generate electrici...
Article
Control loop performance assessment techniques assume that the data being analyzed is generated during steady state operation with fixed plant dynamics and controller parameters. However, in industrial settings one often encounters environmental and feedstock variations which can induce significant changes in the plant dynamics. Availability of dat...
Chapter
Increasing demand for electricity, depleting reservoirs of fossil fuels and increasing environmental concerns, call for efficient and clean utilization of available energy. Electrochemical technologies such as batteries, fuel cells and flow batteries are promising alternatives for such clean and efficient energy conversion. While extensive heuristi...