A test of models for fungal growth based on metabolic heat rate measurements

This paper presents a test of modelling of fungal growth based on the heat produced by Penicillium roqueforti growing on malt extract agar. Thermal power (heat production rate) of P. roqueforti was measured by isothermal calorimetry at 10, 15, 20, 25 and 30°C. The equivalent diameter of similar colonies growing at 20°C were measured by image analysis. Four predictive equations including time lag were tested on the thermal power curves for the accelerated growth phase. All equations were successful in fitting the growth curves and the result did not suggest that one of the equations was superior to the others. P. roqueforti had the fastest growth at 25°C as judged form the thermal power curves and simulation results. Calorimetric measurements have several advantages over conventional techniques. For example calorimetric measurements are continuous and not limited to organisms growing on agar surfaces; also growth inside of a substrate can be studied. Therefore calorimetry can be a valuable measurement technique in predictive microbiology

Real time detection of pathogenic bacteria in veterinary microbiology using isothermal microcalorimetry - A different approach.

With today's challenges regarding antibiotic resistance and the importance of the implementation of prudent use of antibiotics, fast and reliable diagnostic tools for bacterial infections and subsequent antimicrobial susceptibility testing are of utmost relevance. Isothermal microcalorimetry (IMC) is a broadly applicable method, with which metabolic heat flow in reproducing bacteria can be measured in real time. To the best of the authors' knowledge, this is the first report on examination of 124 urine samples from feline and canine urinary tract infection with an IMC-based prototype instrument. A concentration-dependent time of peak heat flow by dilution series with Escherichia coli and Enterococcus faecalis reference strains demonstrated the general good performance of the prototype for detection of these bacteria. With diagnostic culture being set as a gold standard, the diagnostic sensitivity of IMC compared to bacteriological culture was 80 %, the diagnostic specificity was 97 %. With a Cohens' kappa value (κ) of 0.80, the two methods show good concordance. The results from our study demonstrate that the IMC technology is suitable to allow reliable, but much faster detection of bacteria than conventional culture, especially for Escherichia coli. Thus, implementing IMC technology could markedly speed up the bacteriological diagnostic process in veterinary medicine

Use of isothermal microcalorimetry to monitor microbial activities

Isothermal calorimetry measures the heat flow of biological processes, which is proportional to the rate at which a given chemical or physical process takes place. Modern isothermal microcalorimeters make measurements of less than a microwatt of heat flow possible. As a result, as few as 10 000-100 000 active bacterial cells in culture are sufficient to produce a real-time signal dynamically related to the number of cells present and their activity. Specimens containing bacteria need little preparation, and isothermal microcalorimetry (IMC) is a nondestructive method. After IMC measurements, the undisturbed samples can be evaluated by any other means desired. In this review, we present a basic description of microcalorimetry and examples of microbiological applications of IMC for medical and environmental microbiology. In both fields, IMC has been used to quantify microbial activity over periods of hours or even days. Finally, the recent development of highly parallel instruments (up to 48 channels) and the constantly decreasing costs of equipment have made IMC increasingly attractive for microbiology. Miniaturization of isothermal calorimeters provides an even wider range of possibilitie

The SOX experiment in the neutrino physics

SOX (Short distance neutrino Oscillations with BoreXino) is a new experiment that takes place at the Laboratori Nazionali del Gran Sasso (LNGS) and it exploits the Borexino detector to study the neutrino oscillations at short distance. In different phases, by using two artificial sources Cr-51 and Ce-144-Pr-144, neutrino and antineutrino fluxes of measured intensity will be detected by Borexino in order to observe possible neutrino oscillations in the sterile state. In this paper an overview of the experiment is given and one of the two calorimeters that will be used to measure the source activity is described. At the end the expected sensitivity to determine the neutrino sterile mass is shown

Calorimetric systems designed for in-field nondestructive assay of plutonium-bearing materials

Conventional calorimetric design measures the temperature rise of a plutonium-containing sample chamber in contact with a large water-bath heat sink. This design lacks the mobility needed by inspection personnel. The Argonne National Laboratory air-chamber isothermal calorimeters are low-thermal capacitance devices which eliminate the need for large, constant-temperature heat sinks. A bulk calorimeter designed to measure sealed containers holding up to 3 kg Pu, and a small-sample calorimeter designed to measure mixed-oxide fuel pellets and powders are discussed. The operational characteristics of these instruments are described, and the results of sample assays are presented. (2 figs., 2 tables

Prediction criteria of thermal runaway in the acid catalyzed sterification of acetic anhydride

Sviluppo di un modello della reazione di esterificazione di anidride acetica con metanolo catalizzata da acido solforico. Conseguente applicazione di criteri per la previsione del runaway termico e simulazione di guasti e variazioni rispetto al normale comportamento del sistem

Nanocalorimetry

International audience1. Definition Calorimetry is the part of thermodynamics which aims to measure any quantity of heat (enthalpy, specific heat, heat release) stored, released or brought into play in any state of matter, in a reaction, or in phase transitions [Lavoisier1780]. More precisely, the terminology of "Nanocalorimetry" may cover different concepts depending on the area of science where it is used. It concerns any calorimetric method in which either the samples to be studied have a size in the range of the nanometer scale or the measured energies involved are of the order of the nanojoule or below

Battery Efficiency Measurement for Electrical Vehicle and Smart Grid Applications Using Isothermal Calorimeter: Method, Design, Theory and Results

The chapter primarily explores the likelihood of heat measurement by means of the calorimeter in the lithium-ion battery cells for different applications. The presented focus applications are electrical vehicle and smart grid application. The efficiency parameter for battery cell is established using state of the art isothermal calorimeter by taking the consideration of heat related measurement. The calorimeter is principally used for the determination of the heat flux of the battery cell. The main target is to achieve the precision and accuracy of measurement of battery cell thermal performance. In this chapter, the assessment of battery efficiency parameter is proposed. A newly devised efficiency calculation methodology is projected and illustrated. The procedure ensures the precision an accurate measurement of heat flux measurement and turns into more comparable efficiency parameter. In addition, the issue is to investigate thermal sensitivity to factors that influence the energy storage system performance, i.e., current rate and temperature requirements. The results provide insight into the establishment of new key performance indicator (KPI) efficiency specification of the battery system. The usage of the calorimetric experiments is presented to predict the temperature distribution over a battery cell and an array of cells