Estimating growth kinetics of Penicillium chrysogenum through the use of respirometry

The applicability of respirometry to characterize fungal growth kinetics was studied using Penicillium chrysogenum as the model microorganism. Oxygen uptake data were used in conjunction with a nonlinear parameter estimation technique to determine the kinetic parameters associated with microbial growth. The theoretical model that used the Contois equation for microbial growth was able to accurately describe experimental oxygen uptake data. Penicillium chrysogenum was characterized by average values of 0·195 h⁻¹ and 4·13 for the maximum specific growth rate, μ_max, and the Contois saturation coefficient, K_c, respectively. The average true growth yield was 0·405 mg mg⁻¹. As only oxygen uptake information is required for biokinetic parameter estimation, respirometry is a very convenient tool for studying microbial growth as high quality experimental data can be obtained with relatively little experimental effort. © 1998 SCI     

Role of Cerium on the Intricacies of Deformed State and Softening Mechanisms of Low-Carbon Steels

The present study investigates the softening kinetics of two cerium (Ce)-modified steels after 60% cold rolling and annealing at 600 °C for 2–16 h. Cold rolling accumulates substantial strain in the ferritic matrix of low Ce (LCe) steel (0.03 wt% Ce) compared to high Ce (HCe) steel (0.6 wt% Ce). The acicular ferrite and Fe₃C partition the imposed strain preferentially inside the ferrite matrix of LCe sample. Contrarily, a homogenous strain distribution in HCe sample is promoted by soft Ce₂O₃ particles embedded in ferrite. Both the steels achieve partial recovery and recrystallization even after 16 h of annealing. LCe steel experiences a softening fraction of ≈28 vol% after 16 h, inferior to HCe steel (≈34 vol%). During initial stage of annealing, nucleation of strain-free grains are observed in LCe sample due to availability of grain and interphase boundaries. Subsequently, recrystallization kinetics get delayed because of the pinning effect exerted by fine CeO₂ and Fe₃C particles. In HCe samples, the early stage of ferrite nucleation is hindered by the segregation of Ce at grain boundaries. However, at a later stage, the recrystallization kinetics are accelerated owing to the ineffective pinning of dislocations and boundaries by coarse Ce₂Fe₁₇ and Ce₂C₃ particles.     

Thermal management and simulation studies of a 200-kW calorimetric dummy load for HE11 mode at 42 GHz

The objective of this study is to design a calorimetric dummy load (CDL) containing an efficient cooling mechanism to absorb maximum power of 200 kW at 42 ± 0.2 GHz frequency for maximum duration of 3 seconds. The design is suited for microwave power propagating in HE₁₁ mode. High microwave power is generally measured and characterized by CDL, which is designed to suit the exiting modes of the gyrotron. In the current project, the output mode of the gyrotron in TE₀₃ is converted to a Gaussian HE₁₁ mode with help of series of mode converters. This study highlights thermal analysis and simulation studies using ANSYS computational fluid dynamics analysis for water coolant passing through helical teflon tubing. Analytical calculations for thermal management of water coolant are also carried out and compared with the simulation studies. A defocusing convex mirror has been designed using a quasi-optical approach. Material selection of the defocusing mirror, based on cost-effectiveness, transient thermal analysis, and microwave power absorption in the skin depth of the material, has been carried out. Finally, a comparison of analytical calculation and simulation studies has been carried out.     

A deterministic digital calibration technique for pipelined ADCs using a non-nested algorithm

Analog Integrated Circuits and Signal Processing - This paper proposes a novel deterministic technique to digitally calibrate 1.5-bits/stage and 1-bit/stage pipelined as well as algorithmic...     

Prediction of Cardiovascular Disease Using Machine Learning Technique—A Modern Approach

Cardio Vascular disease (CVD), involving the heart and blood vessels is one of the most leading causes of death throughout the world. There are several risk factors for causing heart diseases like sedentary lifestyle, unhealthy diet, obesity, diabetes, hypertension, smoking and consumption of alcohol, stress, hereditary factory etc. Predicting cardiovascular disease and improving and treating the risk factors at an early stage are of paramount importance to save the precious life of a human being. At present, the highly stressful life with bad lifestyle activities causes heart disease at a very young age. The main aim of this research is to predict the premature heart disease based on machine learning algorithms. This paper deals with a novel approach using the machine learning algorithm for predicting the cardiovascular disease at the premature stage itself. Support Vector Machine (SVM) is used for segregating the CVD patients based on their symptoms and medical observation. The experimentation results by using the proposed method will facilitate the medical practitioners to provide suitable treatment for the patients on time. A sophisticated model has been developed with the current approach to examine the various stages of CVD and the performance metrics used have given effective and fruitful results as compared to other machine learning techniques.     

Scraped surface heat exchangers

Scraped surface heat exchangers (SSHEs) are commonly used in the food, chemical, and pharmaceutical industries for heat transfer, crystallization, and other continuous processes. They are ideally suited for products that are viscous, sticky, that contain particulate matter, or that need some degree of crystallization. Since these characteristics describe a vast majority of processed foods, SSHEs are especially suited for pumpable food products. During operation, the product is brought in contact with a heat transfer surface that is rapidly and continuously scraped, thereby exposing the surface to the passage of untreated product. In addition to maintaining high and uniform heat exchange, the scraper blades also provide simultaneous mixing and agitation. Heat exchange for sticky and viscous foods such as heavy salad dressings, margarine, chocolate, peanut butter, fondant, ice cream, and shortenings is possible only by using SSHEs. High heat transfer coefficients are achieved because the boundary layer is continuously replaced by fresh material. Moreover, the product is in contact with the heating surface for only a few seconds and high temperature gradients can be used without the danger of causing undesirable reactions. SSHEs are versatile in the use of heat transfer medium and the various unit operations that can be carried out simultaneously. This article critically reviews the current understanding of the operations and applications of SSHEs.     

Rapid extraction and detection of trace Chlorpyrifos-methyl in orange juice by surface-enhanced Raman spectroscopy

It is estimated that 20–50% of crops are saved from infestation through the use of pesticides. However, US inspectors find that more than 4% of fruits and vegetables imported exceed concentration levels considered safe for human consumption. This represents millions of tons of food brought to market annually that cannot be inspected using current hour-long laboratory methods. In an effort to provide inspectors with a simple, fast, field-usable analyzer and method, we have been developing a sampling device that includes surface-enhanced Raman spectroscopy (SERS) to detect, identify, and quantify pesticides below part-per-million (μg/mL) concentrations in approximately 10 min using a portable Raman analyzer. The entire method, including solvent extraction, solid-phase extraction, and SERS-detection, was used to detect 50 parts-per-billion (ppb) Chlorpyrifos-methyl (CPM) artificially added to orange juice in 12 min. The same method and analyzer can be readily adapted to other pesticides and foods.     

Transboundary sharing of river water: Informating the policies

This paper presents an ontological framework that concisely captures the combinatorial complexity of river water sharing and visualizes the problem in its entirety. The framework's dimensions, the dimensions' taxonomies, and the resultant pathways are a complete, closed representation of the river water sharing problem. The framework is transdisciplinary; it is grounded in the research, the legal, and the practice literature on river water sharing. The authors illustrate the method and the application of the framework with the case study of Cauvery River water dispute between the Indian states of Karnataka and Tamil Nadu. The approach can help develop innovative pathways to resolve such problems.     

Alterations in antioxidant enzyme activities and oxidative damage in alcoholic rat tissues: Protective role of Thespesia populnea

Recent advances in our understanding of the pathogenesis of alcohol-induced hepato-renal injury and the development of new approaches to its treatment have been reported in various works. This study involves alcohol-induced oxidative stress linked to the metabolism of ethanol involving both mitochondrial and peroxisomal fractions of liver and kidney. Alcohol treatment resulted in the depletion of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), Glutathione-S-Transferase (GST) activities, and reduced glutathione (GSH) content, higher level of malondialdehyde (MDA) and lower levels of protein carbonyls (PC) causing malfunction of hepatic and renal tissues, when compared to control rats. Thespesia populnea (TP) leaf extracts, administered to chronic alcohol ingested rats, were envisaged to possess significant antioxidant defence properties and help in the recovery of tissues from alcohol-induced oxidative damage. The results showed that degenerative changes in hepatic and renal cells of alcoholic groups were minimized by the administration of TP leaf extracts as also revealed by histopathological examination. The current findings indicate that treatment with TP extracts reduces alcohol-induced oxidative stress, thereby protecting the hepatic and renal tissue from alcohol-induced damage.