• Title/Summary/Keyword: Calorimetry

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Historical Development of Nutrient and Calorimetry and Expired Gas Analysis Indirect Calorimetry (영양소와 열량측정법의 발달과정 및 간접 열량 측정법)

  • Yoon, Byung-Kon;Kim, Jong-Won;Kim, Do-Yeon
    • Journal of Life Science
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    • v.20 no.8
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    • pp.1159-1165
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    • 2010
  • Indirect calorimetry is the measurement of the amount of heat generated in an oxidation reaction by determining the intake or consumption of oxygen or by measuring the amount of carbon dioxide or nitrogen released and translating these quantities into a heat equivalent. In the last 20 years there has been significant development in both laboratory and computerized metabolic systems used in indirect calorimetry. In addition, there has been increased use of breath-by-breath EGAIC. Several researchers have suggested that breath-by-breath analysis, because of their practicality, could fulfill this need for a valid and reliable expired gas analysis indirect calorimetry instrument. It was hoped this investigation would determine the best validation for a precise measurement of breath-by-breath expired gas analysis indirect calorimetry. The problem with the available research is that few studies have examined the validity and reliability of all these different systems for breath-by-breath expired gas analysis indirect calorimetry. Therefore, there is a need to find out the most valid, reliable, and precise measurement of the breath-by-breath expired gas analysis indirect calorimetry.

Calorimetry for the Measurement of Heat Leak (열량법에 의한 열침입량의 계측)

  • 김동락;양형석;김도형;조승연;정원묵;이제묘
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2003.10a
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    • pp.328-331
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    • 2003
  • In this study, the experimental study based on calorimetry for terminal cryostat has been performed and evaluated. The experiments performed here were divided into two types, those are test without and with current lead. The former is intended for the evaluation of feasibility and precision of our calorimetry, the later for the application to terminal cryostat of our study. As a result, it was found that the calorimetry performed in this study could predict well the heat transfer rate into the terminal cryostat.

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Determining the appropriate resting energy expenditure requirement for severe trauma patients using indirect calorimetry in Korea: a retrospective observational study

  • Hak-Jae Lee;Sung-Bak Ahn;Jung Hyun Lee;Ji-Yeon Kim;Sungyeon Yoo;Suk-Kyung Hong
    • Journal of Trauma and Injury
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    • v.36 no.4
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    • pp.337-342
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    • 2023
  • Purpose: This study aimed to compare the resting energy expenditure (REE) measured using indirect calorimetry with that estimated using predictive equations in severe trauma patients to determine the appropriate caloric requirements. Methods: Patients admitted to the surgical intensive care unit between January 2020 and March 2023 were included in this study. Indirect calorimetry was used to measure the patients' REE values. These values were subsequently compared with those estimated using predictive equations: the weight-based equation (rule of thumb, 25 kcal/kg/day), Harris-Benedict, Ireton-Jones, and the Penn State 2003 equations. Results: A total of 27 severe trauma patients were included in this study, and 47 indirect calorimetric measurements were conducted. The weight-based equation (mean difference [MD], -28.96±303.58 kcal) and the Penn State 2003 equation (MD, - 3.56±270.39 kcal) showed the closest results to REE measured by indirect calorimetry. However, the REE values estimated using the Harris-Benedict equation (MD, 156.64±276.54 kcal) and Ireton-Jones equation (MD, 250.87±332.54 kcal) displayed significant differences from those measured using indirect calorimetry. The concordance rate, which the predictive REE differs from the measured REE value within 10%, was up to 36.2%. Conclusions: The REE values estimated using predictive equations exhibited substantial differences from those measured via indirect calorimetry. Therefore, it is necessary to measure the REE value through indirect calorimetry in severe trauma patients.

The Use of Semi-Adiabatic Calorimetry for Hydration Studies of Cement Paste

  • Chung, Chul-Woo;Kim, Ji-Hyun;Lee, Soo-Yong
    • Journal of the Korea Institute of Building Construction
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    • v.16 no.2
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    • pp.185-192
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    • 2016
  • The semi-adiabatic calorimetry technique is a robust and easy technique that can be used to measure the temperature rise of concrete. This method is often used for investigating the maturity of concrete, as well as to predict maximum temperature rise of mass concrete using various heat loss compensating models. Semi-adiabatic calorimetry can also be used for predicting setting time of concrete. However, it has seldom been used to investigate the hydration characteristics of various cement paste samples. In this research, semi-adiabatic calorimetry and X-ray diffraction methods were used to investigate the hydration characteristics of 3 different ASTM type I Portland cements. First derivative of temperature rise (dT/dt) curve was used to isolate individual peaks. Based on the results of the experiments, a combination of dT/dt curve with XRD could be used to successfully identify hydration at a specific time period, showing its potential to be used as an alternative tool for hydration studies of cement-based materials.

Study on the thermal Property and Aging Prediction for Pressable Plastic Bonded Explosives through ARC(Heat-Wait-Search method) & isothermal conditions (ARC(Heat-Wait-Search method)와 isothermal 조건을 이용한 압축형 복합화약의 열적 특성 및 노화 예측 연구)

  • Lee, Sojung;Kim, Jinseuk;Kim, Seunghee;Kwon, Kuktae;Chu, Chorong;Jeon, Yeongjin
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.172-178
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    • 2017
  • Thermal property is one of the important characteristic in the field of energetic materials. As the energy material is released during decomposition, DSC(Differential Scanning Calorimetry) is frequently used for the thermal analysis. In case of the dynamic DSC measurements, thermal dynamic change like melting is prevented from the thermal property measurements. And due to the predicting kg scale, the conditions of the heat exchange with the environment significantly is changed. In this study, As the method to resolve the problem, we predict the thermal aging property using the AKTS thermokinetic program from DSC measurements which performed isothermal method. Predicting the thermal aging properties from ARC(Accelerating Rate Calorimetry) measurement, we compare two results.

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The Thermal Stability Analysis of Fumes and Mists During the Drying Process of a PCB (PCB 건조공정의 흄과 미스트에 대한 열안정성 분석)

  • Chu, Chang Yeop;Lee, Jung Suk;Baek, Jong Bae
    • Journal of the Korean Society of Safety
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    • v.34 no.4
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    • pp.32-40
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    • 2019
  • During the manufacturing process of a printed circuit board(PCB), fumes and mists are generated as the ink dries on the PCB surface. The generated fumes and mists are deposited in the dryer wall and the exhaust duct. Deposited fumes and mists may present a fire hazard if the dryer temperature control system fails. In this study, the thermal stability of the fumes and mists deposited in the dryer and ducts has been analyzed by experimental methods such as thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), auto ignition temperature (AIT), and multiple mode calorimetry(MMC). According to the experimental analyses, experimental samples are likely to generate gas at the temperature ($180{\sim}240^{\circ}C$) that deviates from the normal operating temperature ($150{\sim}156^{\circ}C$). It has been shown that the thermal stability is degraded when the temperature is deviated from the normal operating temperature. In the end, engineering and management safety measures of accidental prevention have been suggested.

Study on the Thermal Property and Aging Prediction for Pressable Plastic Bonded Explosives through ARC(Heat-wait-search method) & Isothermal Conditions (ARC(Heat-wait-search method)와 Isothermal 조건을 이용한 압축형 복합화약의 열적 특성 및 노화 예측 연구)

  • Lee, Sojung;Kim, Seunghee;Kwon, Kuktae;Jeon, Yeongjin
    • Journal of the Korean Society of Propulsion Engineers
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    • v.22 no.4
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    • pp.55-60
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    • 2018
  • The thermal property is one of the most important characteristics in the field of energetic materials. Because energy materials release decomposition heat, differential scanning calorimetry (DSC) is frequently used for thermal analysis. However, thermodynamic events, such as melting can interfere with DSC kinetic analysis. In this study, we use isothermal mode for DSC measurement to avoid thermodynamic issues. We also merge accelerating rate calorimetry(ARC) data with DSC data to obtain a robust prediction results for small scale samples and for large scale samples as well. For the thermal property prediction, advanced kinetics and technology solutions(AKTS) programs are used.

Differential Scanning Calorimetry of Rice Starch (쌀 전분의 Differential Scanning Calorimetry)

  • Hyun, Chang-Kee;Park, Kwan-Hwa;Kim, Young-Bae;Yoon, In-Hwa
    • Korean Journal of Food Science and Technology
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    • v.20 no.3
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    • pp.331-337
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    • 1988
  • The thermal properties of typical five Indica and five Japonica rice varieties were investigated by Differential Scanning Calorimetry (DSC). There was no significant difference in gelatinization temperature between Indica and Japonica varieties, but the average enthalpy of gelatinization was larger in Indica types than that in Japonica. However, the enthalpy of melting of amylose-lipid complex was larger in Japonica types than that in Indica types. The DSC thermogram of hydrolyzed rice residue included a smaller peak of gelatinization with narrow range of temperature. Retrogradation of gelatinized rice kernel was also determined with DSC theremograms. The endothermic peak areas clearly increased with increasing storage time at $4^{\circ}C$ so that the area could be used as a measure of the relative degree of retrogradation. The results indicated that Samgang variety(Indica) retrograded more rapidly than Chuncheong variety(Japonica).

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