• Title/Summary/Keyword: state equations

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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.

Physicochemical properties and energy content of yellow dent corn from different climatic origins in growing pigs

  • Dong, Wenxuan;Li, Juntao;Li, Zhongchao;Zhang, Shuo;Li, Xiaozhen;Yang, Chundi;Liu, Ling;Zhang, Shuai
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.11
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    • pp.1787-1796
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    • 2020
  • Objective: The objective of this study was to determine the digestible energy (DE) and metabolizable energy (ME) of yellow dent corn sourced from different meteorological origins fed to growing pigs and develop equations to predict the DE and ME of yellow dent corn from southwestern China. Methods: Sixty crossbred barrows were allotted to 20 treatments in a triplicate 20×2 incomplete Latin square design with 3 replicated pigs per dietary treatment during 2 consecutive periods. Each period lasted for 12 days, and total feces and urine during the last 5 days of each period were collected to calculate the energy contents. Results: On dry matter (DM) basis, the DE and ME in 20 corn grain samples ranged from 15.38 to 16.78 MJ/kg and from 14.93 to 16.16 MJ/kg, respectively. Selected best-fit prediction equations for DE and ME (MJ/kg DM basis) for yellow dent corn (n = 16) sourced from southwestern China were as follows: DE = 28.58-(0.12×% hemicellulose)+(0.35×% ether extract)-(0.83×MJ/kg gross energy)+(0.20×% crude protein)+(0.49×% ash); ME = 30.42-(0.11×% hemicellulose)+(0.31×% ether extract)-(0.81×MJ/kg gross energy). Conclusion: Our results indicated that the chemical compositions, but not the meteorological conditions or physical characteristics could explain the variation of energy contents in yellow dent corn sourced from southwestern China fed to growing pigs.

Net energy and its establishment of prediction equations for wheat bran in growing pigs

  • Zhiqian, Lyu;Yifan, Chen;Fenglai, Wang;Ling, Liu;Shuai, Zhang;Changhua, Lai
    • Animal Bioscience
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    • v.36 no.1
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    • pp.108-118
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    • 2023
  • Objective: The objective of this experiment was to determine the net energy (NE) value of 6 wheat bran and 1 wheat shorts by indirect calorimetry and establish the NE prediction equations of wheat bran fed to growing barrows. Methods: Forty-eight growing barrows (28.5±2.4 kg body weight) were allotted in a completely randomized design to 8 dietary treatments that included a corn-soybean meal basal diet, 6 wheat bran diets and 1 wheat shorts diet. The inclusion level of wheat bran or wheat shorts in diets is 30%. Results: The addition of wheat bran reduced the apparent total tract digestibility (ATTD) of nutrients (p<0.05). The ATTD of gross energy, crude protein (CP) and dry matter (DM) in the wheat shorts were greater than that in the wheat bran. Addition of wheat bran or wheat shorts had no effect on total heat production and fasting heat production. The NE of wheat bran was negatively correlated with neutral detergent fiber (r = -0.84; p<0.05) and acid detergent fiber (r = -0.83; p<0.05), while it was positively correlated with CP (r = 0.92; p<0.01). The NE values of wheat bran ranged from 6.79 to 8.15 MJ/kg DM, and the NE value of wheat shorts was 12.47 MJ/kg DM. The ratio of NE to metabolizable energy for wheat bran fed to growing pigs was from 66.0% to 71.7%, whereas the value for wheat shorts was 83.7%. Conclusion: The NE values of wheat bran ranged from 6.79 to 8.15 MJ/kg DM, and the NE value of wheat shorts was 12.47 MJ/kg DM. The NE value of wheat bran can be well predicted based on energy content and proximate analysis.

Modeling of Thermodynamic Properties of Saturated state Hydrogen using Equation of State (상태방정식을 이용한 포화상태 수소의 열역학적 물성 모델링)

  • Bong-Seop Lee;Hun Yong Shin;Choong Hee Joe
    • Korean Chemical Engineering Research
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    • v.61 no.4
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    • pp.550-554
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    • 2023
  • Fossil energy sources are limited in their sustainable use and expansion due to global warming caused by carbon dioxide emissions. Hydrogen is considered as a promising alternative to traditional fossil fuels. To ensure the stable long-term storage, it is necessary to accurately predict its thermodynamic properties at cryogenic temperatures. Therefore, this study aimed to investigate thermodynamic properties, such as saturated vapor pressure and density, enthalpy, and entropy of liquid and gas, using cubic equations of state that demonstrate relatively simple relationships. Among the three types of equations of state (Redlich-Kwong (RK), Soave-Redlich-Kwong (SRK), and Peng-Robinson (PR)), the SRK model exhibited relatively accurate prediction results for various physical properties.

Inter-scale Observation and Process Optimization for Guanosine Fermentation

  • Chu, Ju;Zhang, Si-Liang;Zhuang, Ying-Ping
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 2005.06a
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    • pp.233-244
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    • 2005
  • Guanosine fermentation process can be well predicted and analyzed by the proposed state equations describing the dynamic change of a bioreactor. Pyruvate and alanine were found to be characteristically accumulated along with the decline of the guanosine formation rate during the mid-late phase of the process. The enzymological study of the main pathways in glucose catabolism and the quantitative stoichiometric calculation of metabolic flux distribution revealed that it was entirely attributed to the shift of metabolic flux from hexose monophosphate (HMP) pathway to glycolysis pathway. The process optimization by focusing on the restore of the shift of metabolic flux was conducted and the overcoming the decrease of oxygen uptake rate (OUR) was taken as the relevant factor of the trans-scale operation. As a result, the production of guanosinewas increased from 17 g/L to over 34 g/I.

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Informational and Methodological Approach to Ensuring the Economic Security of the State in the Banking Sphere

  • Shemayeva, Luidmila;Hladkykh, Dmytro;Mihus, Iryna;Onofriichuk, Andrii;Onofriichuk, Vitalii
    • International Journal of Computer Science & Network Security
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    • v.21 no.12spc
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    • pp.477-482
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    • 2021
  • The existing approaches to ensuring the banking security of the state do not take into account the peculiarities of the banking system in the rapid development of the information economy (increasing uncertainty, imbalance and nonlinearity of processes in the banking system under the influence of innovation, institutions, information asymmetry, etc.). A methodological approach to determining the synergetic effect in the implementation of the regulatory influence of the state on the development of innovation processes related to informatization in the banking system, based on the use of differential equations and modelling the sensitivity of innovation processes related to informatization in the banking system, to the regulatory influence of the state to prevent the deployment of risks and threats to economic security of the state in this area has been suggested in the present article.

Simulation of Combustion Phenomena at Multiple Injection in HSDI Diesel Engine Using Modified Two Dimensional Flamelet Combustion Model (개량된 2 차원 화염편 연소 모델을 이용한 고속 직분식 엔진에서의 다단 분사시 연소 현상 해석)

  • Lim, Jae-Man;Min, Kyoung-Doug
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.3300-3305
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    • 2007
  • Ignition delay of second injection of HSDI diesel engine was usually much shorter than that of first injection. It is due to the interaction between radicals generated during the combustion process, and mixed gas of second injection. In this paper, To analyze combustion phenomena of multiple injection mode in HSDI diesel engine effectively, two-dimensional flamelet combustion model was modified. To reduce calculation time, two-dimensional flamelet equations were only applied near stoichiometric region. If this region was ignited, species and temperature of other region were changed to the steady-state solutions of one dimensional flamelet equations. By this method calculation time for solving flamelet equations was reduced to 20 percents, thought the results were almost same. Modified flamelet combustion model was coupled to commercial CFD code interactively using user subroutine.

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A Study on the Analysis of Various Characteristics for the High Pressure are Discharge System (고압 아아크 방전시스템의 각종 특성 해석에 관한 연구)

  • 지철근;박왕열;이진우
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.5 no.4
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    • pp.35-42
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    • 1991
  • Recently, HID lamps have been considered as important in regard to the trend of energy saving, and increasingly and diversely used in various ways. This paper will show the simulating models concerning high-pressure arc discharge system directly applicable for its design and manufacture, and analyze its various characteristics. For warm-up characteristics, the evaporating process of inner atoms is described in terms of second-order differential equation: for the thermal conduction from are axis to discharge wall and outer bulb, its transfer process is introduced according to five first-order differential equations. Under the steady state satisfying LTE, the time-variant characteristics are suggested by means of time-dependent energy balance equation derived from fluid equations, approximation of radiation energy and material functions in the discharge tube. The simulating models concerning these equations are then applied for high-pressure mercury lamp.

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Optimal Design of Integrated Control System Considering Soil-Structure Interaction (지반-구조물 상호작용을 고려한 복합제어시스템의 최적설계)

  • Park, Kwan-Soon;Park, Jang-Ho
    • Journal of the Korean Society of Safety
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    • v.27 no.2
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    • pp.57-64
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    • 2012
  • For the vibration control of earthquake-excited buildings, an optimal design method of integrated control system considering soil-structure interaction is studied in this paper. Interaction between soils and the base of the building is simply modeled as lumped parameters and equations of motion are derived. The equations of motion are transformed into the state space equations and the probabilistic excitations such as Kanai-Tajumi power spectral density function is introduced. Then an optimization problem is formulated as finding hybrid or integrated control systems which minimizes the stochastic responses of the building structure for given constraints. In order to investigate the feasibility of the optimization method, an example design and numerical simulations are performed with tenstory building. Finally, numerical results are compared with a conventional design case that soil-structure interaction is not considered.

The effect of finite strain on the nonlinear free vibration of a unidirectional composite Timoshenko beam using GDQM

  • Ghasemi, Ahmad Reza;Mohandes, Masood
    • Advances in aircraft and spacecraft science
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    • v.3 no.4
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    • pp.379-397
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    • 2016
  • In this manuscript, free vibrations of a unidirectional composite orthotropic Timoshenko beam based on finite strain have been studied. Using Green-Lagrange strain tensor and comprising all of the nonlinear terms of the tensor and also applying Hamilton's principle, equations of motion and boundary conditions of the beam are obtained. Using separation method in single-harmonic state, time and locative variables are separated from each other and finally, the equations of motion and boundary conditions are gained according to locative variable. To solve the equations, generalized differential quadrature method (GDQM) is applied and then, deflection and cross-section rotation of the beam in linear and nonlinear states are drawn and compared with each other. Also, frequencies of carbon/epoxy and glass/epoxy composite beams for different boundary conditions on the basis of the finite strain are calculated. The calculated frequencies of the nonlinear free vibration of the beam utilizing finite strain assumption for various geometries have been compared to von Karman one.