Engineering topics
Achyuthan, Komandoor
Publications and source records attributed to Achyuthan, Komandoor.
A Hydrogen Bonded Acidic Polymer (DKAP) as a Gas Chromatography Stationary Phase for Organophosphonates and Organophosphates.
Abstract not provided.
μChemLab? ? Twenty Years of Developing CBRNE Detection Systems with Low False Alarm Rates.
Abstract not provided.
μChemLab? ? Twenty Years of Developing CBRNE Detection Systems with Low False Alarm Rates.
Abstract not provided.
ChemLab? ? Twenty Years of Developing Microfabricated gas Analyzer for Chemical Detection.
Abstract not provided.
Systems for Plant Volatile Organic Compound (VOC) Analysis.
Abstract not provided.
Systems for Plant Volatile Organic Compound (VOC) Analysis.
Abstract not provided.
Investigating the chemical landscape of microalgae cultures to mitigate pond crashes.
Abstract not provided.
Toward Polymer-coated Si Nanowire FETs for Robust Biosensors.
Abstract not provided.
Volatile Metabolites Emission by In Vivo Microalgae—An Overlooked Opportunity?
Fragrances and malodors are ubiquitous in the environment, arising from natural and artificial processes, by the generation of volatile organic compounds (VOCs). Although VOCs constitute only a fraction of the metabolites produced by an organism, the detection of VOCs has a broad range of civilian, industrial, military, medical, and national security applications. The VOC metabolic profile of an organism has been referred to as its ‘volatilome’ (or ‘volatome’) and the study of volatilome/volatome is characterized as ‘volatilomics’, a relatively new category in the ‘omics’ arena. There is considerable literature on VOCs extracted destructively from microalgae for applications such as food, natural products chemistry, and biofuels. VOC emissions from living (in vivo) microalgae too are being increasingly appreciated as potential real-time indicators of the organism’s state of health (SoH) along with their contributions to the environment and ecology. This review summarizes VOC emissions from in vivo microalgae; tools and techniques for the collection, storage, transport, detection, and pattern analysis of VOC emissions; linking certain VOCs to biosynthetic/metabolic pathways; and the role of VOCs in microalgae growth, infochemical activities, predator-prey interactions, and general SoH.
Diagnostic Tools for Measuring Early Chemical Signatures of Algae Pond Crash.
Abstract not provided.
Diagnostic Tools for Measuring Early Chemical Signatures of Algae Pond Crash.
Abstract not provided.
Field Detection of Chemical Agents and VOCs as Early Symptomatic Markers.
Abstract not provided.
Non-Invasive Point-of-Care Detection of Infectious Disease.
Abstract not provided.
Parylene C Aging Studies
Parylene C is used in a device because of its conformable deposition and other advantages. Techniques to study Parylene C aging were developed, and "lessons learned" that could be utilized for future studies are the result of this initial study. Differential Scanning Calorimetry yielded temperature ranges for Parylene C aging as well as post-deposition treatment. Post-deposition techniques are suggested to improve Parylene C performance. Sample preparation was critical to aging regimen. Short-term (%7E40 days) aging experiments with free standing and ceramic-supported Parylene C films highlighted "lessons learned" which stressed further investigations in order to refine sample preparation (film thickness, single sided uniform coating, machine versus laser cutting, annealing time, temperature) and testing issues ("necking") for robust accelerated aging of Parylene C.
Development of field portable microfabricated nitrogen phosphorus and miniature pulse discharge ionization detectors for chemical and biological species.
Abstract not provided.
Spectroscopic Analyses of the Biofuels-Critical Phytochemical Coniferyl Alcohol and Its Enzyme-Catalyzed Oxidation Products
Lignin composition (monolignol types of coniferyl, sinapyl or p-coumaryl alcohol) is causally related to biomass recalcitrance. We describe multiwavelength (220, 228, 240, 250, 260, 290, 295, 300, 310 or 320 nm) absorption spectroscopy of coniferyl alcohol and its laccase- or peroxidase-catalyzed products during real time kinetic, pseudo-kinetic and endpoint analyses, in optical turn on or turn off modes, under acidic or basic conditions. Reactions in microwell plates and 100 mu L volumes demonstrated assay miniaturization and high throughput screening capabilities. Bathochromic and hypsochromic shifts along with hyperchromicity or hypochromicity accompanied enzymatic oxidations by laccase or peroxidase. The limits of detection and quantitation of coniferyl alcohol averaged 2.4 and 7.1 mu M respectively, with linear trend lines over 3 to 4 orders of magnitude. Coniferyl alcohol oxidation was evident within 10 minutes or with 0.01 mu g/mL laccase and 2 minutes or 0.001 mu g/mL peroxidase. Detection limit improved to 1.0 mu M coniferyl alcohol with Km of 978.7 +/- 150.7 mu M when examined at 260 nm following 30 minutes oxidation with 1.0 mu g/mL laccase. Our assays utilized the intrinsic spectroscopic properties of coniferyl alcohol or its oxidation products for enabling detection, without requiring chemical synthesis or modification of the substrate or product(s). These studies facilitate lignin compositional analyses and augment pretreatment strategies for reducing biomass recalcitrance.