scholarly journals Parameter Identification for a New Circuit Model Aimed to Predict Body Water Volume

2012 ◽  
Vol 12 (4) ◽  
pp. 83-86 ◽  
Author(s):  
A.-G. GHEORGHE ◽  
C.-V. MARIN ◽  
F. CONSTANTINESCU ◽  
M. NITESCU
Keyword(s):  
Parameter Identification ◽  
Circuit Model ◽  
Body Water ◽  
Water Volume

Bioelectrical Impedance Analysis of Water Reduction in Lower-Limb Lymphedema by Lymphaticovenular Anastomosis

2018 ◽  
Vol 35 (04) ◽  
pp. 306-314 ◽  
Author(s):  
Yoshichika Yasunaga ◽  
Daisuke Yanagisawa ◽  
Erika Ohata ◽  
Kiyoshi Matsuo ◽  
Shunsuke Yuzuriha
Keyword(s):  
Lower Limb ◽  
Bioelectrical Impedance Analysis ◽  
Linear Regression Analysis ◽  
Reduction Rate ◽  
Bioelectrical Impedance ◽  
Impedance Analysis ◽  
Body Water ◽  
Volume Reduction ◽  
Water Volume ◽  
The Mean

Background Although lymphedema is fundamentally abnormal accumulation of excess water in the extracellular space, previous studies have evaluated the efficacy of physiological bypass surgery (lymphaticovenular anastomosis [LVA]) for lymphedema without measuring water volume. This study clarified the water reductive effect of LVA using bioelectrical impedance analysis (BIA). Methods The efficacy of LVA for unilateral lower-limb lymphedema was evaluated using BIA in a retrospective cohort. The water volume of affected and unaffected legs was measured using multifrequency BIA before and after LVA. Preoperative measurements were undertaken after compression therapy for at least 3 months. The follow-up period after LVA was a minimum of 6 months. Results Thirty consecutive patients with unilateral lower-limb lymphedema were enrolled. The mean water volume reduction of the affected leg by LVA (ΔLBW) was 0.86 L (standard deviation [SD]: 0.86, median: 0.65) with a mean number of 3.3 anastomoses (SD: 1.7). The mean reduction rate of edema was 45.1% (SD: 36.3). Multiple linear regression analysis revealed water volume difference between the affected and unaffected legs before LVA (excess LBW) as the strongest predictor of ΔLBW (R 2 = 0.759, p < 0.01; β = 0.500, p < 0.01). Conclusion The LVA reduces the volume of accumulated body water in lower-limb lymphedema. As excess LBW most strongly predicted the amount of water volume reduction by LVA, body water volume measurement by BIA before LVA might identify patients with low excess LBW not expected to benefit from LVA, regardless of apparent differences in limb circumference.

scholarly journals Water Intake, Water Balance, and the Elusive Daily Water Requirement

Nutrients ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1928 ◽  
Author(s):  
Lawrence Armstrong ◽  
Evan Johnson
Keyword(s):  
Water Balance ◽  
Life Stage ◽  
Body Water ◽  
Water Volume ◽  
Published Data ◽  
Water Requirements ◽  
Neuroendocrine Response ◽  
Organ Systems ◽  
Daily Water ◽  
The Brain

Water is essential for metabolism, substrate transport across membranes, cellular homeostasis, temperature regulation, and circulatory function. Although nutritional and physiological research teams and professional organizations have described the daily total water intakes (TWI, L/24h) and Adequate Intakes (AI) of children, women, and men, there is no widespread consensus regarding the human water requirements of different demographic groups. These requirements remain undefined because of the dynamic complexity inherent in the human water regulatory network, which involves the central nervous system and several organ systems, as well as large inter-individual differences. The present review analyzes published evidence that is relevant to these issues and presents a novel approach to assessing the daily water requirements of individuals in all sex and life-stage groups, as an alternative to AI values based on survey data. This empirical method focuses on the intensity of a specific neuroendocrine response (e.g., plasma arginine vasopressin (AVP) concentration) employed by the brain to regulate total body water volume and concentration. We consider this autonomically-controlled neuroendocrine response to be an inherent hydration biomarker and one means by which the brain maintains good health and optimal function. We also propose that this individualized method defines the elusive state of euhydration (i.e., water balance) and distinguishes it from hypohydration. Using plasma AVP concentration to analyze multiple published data sets that included both men and women, we determined that a mild neuroendocrine defense of body water commences when TWI is ˂1.8 L/24h, that 19–71% of adults in various countries consume less than this TWI each day, and consuming less than the 24-h water AI may influence the risk of dysfunctional metabolism and chronic diseases.

scholarly journals A Simplified Fractional Order Equivalent Circuit Model and Adaptive Online Parameter Identification Method for Lithium-Ion Batteries

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jianlin Wang ◽  
Le Zhang ◽  
Dan Xu ◽  
Peng Zhang ◽  
Gairu Zhang
Keyword(s):  
Parameter Identification ◽  
Least Squares ◽  
Equivalent Circuit ◽  
Fractional Order ◽  
Equivalent Circuit Model ◽  
Lithium Ion ◽  
Circuit Model ◽  
Stability And Convergence ◽  
Battery Management System ◽  
Identification Method

In order to improve the battery management system performance and enhance the adaptability of the system, a fractional order equivalent circuit model of lithium-ion battery based on electrochemical test was established. The parameters of the fractional order equivalent circuit model are identified by the least squares parameter identification method. The least squares parameter identification method needs to rely on the harsh test conditions of the laboratory, and the parameter identification result is static; it cannot adapt to the characteristics of the lithium battery under dynamic conditions. Taking into account the dynamic changes of lithium batteries, a parameter adaptive online estimation algorithm for fractional equivalent circuit model is proposed. Based on the theory of fractional order calculus and indirect Lyapunov method, the stability and convergence of the estimator are analyzed. Finally, simulation experiments show that this method can continuously estimate the parameters of the fractional order equivalent circuit under UDDS conditions.

Accuracy of the tritium water dilution method for determining water flux in reindeer (Rangifer tarandus)

1976 ◽  
Vol 54 (6) ◽  
pp. 857-862 ◽  
Author(s):  
R. D. Cameron ◽  
R. G. White ◽  
J. R. Luick
Keyword(s):  
Total Body Water ◽  
Crude Protein ◽  
Tritiated Water ◽  
Water Flux ◽  
Body Water ◽  
Water Volume ◽  
Dilution Method ◽  
Wide Range ◽  
Total Body ◽  
Water Dilution

The accuracy of the tritium water dilution method in estimating water flux was evaluated in reindeer under various conditions of temperature and diet. Two non-pregnant female reindeer were restrained in metabolism stalls, within controlled-environment chambers, at temperatures of + 10, −5, and −20 °C; varying amounts of a commercial pelleted ration (crude protein, 13%) or mixed lichens (crude protein, 3%) were offered, and water was provided ad libitum either as snow or in liquid form. Total body water volume and water turnover were estimated using tritiated water, and the daily outputs of feces and urine were measured for each of 12 different combinations of diet and temperature. Statistical analysis of the data showed that the tritium water dilution technique gives accurate determinations of total body water flux over a wide range of environmental and nutritional conditions.

An Improved Supercapacitor Model and its Parameter Identification for Wind Power Flow Optimization and Control System

2010 ◽  
Vol 121-122 ◽  
pp. 916-921 ◽  
Author(s):  
Yan Lei Zhao ◽  
Hai Dong Li ◽  
Hou Sheng Zhang ◽  
Xue Ting Liu
Keyword(s):  
Control System ◽  
Parameter Identification ◽  
Wind Power ◽  
Power Flow ◽  
Circuit Model ◽  
Circuit Analysis ◽  
Operating Characteristics ◽  
Flow Optimization ◽  
Optimization And Control ◽  
And Control

According to the operating characteristics of the wind power flow optimization and control system, an improved supercapacitor euqivalent circuit model is proposed, which characterizes termimanl behavior of the supercapacitor in the time ranges from several seonds to several minutes as well as the influence of lekage current in hours range. By the method of circuit analysis, parameter identification of the model is deduced in detail. The smilation and expriment results indicate the model and its parameter idenfication method proposed in the paper are feasible and effective.

In vivo estimation of body composition of lactating dairy cattle from urea space measurements

2001 ◽  
Vol 2001 ◽  
pp. 206-206 ◽  
Author(s):  
R. E. Agnew ◽  
W J McCaughey ◽  
J.D. McEvoy ◽  
D C Patterson ◽  
M G Porter ◽  
...  
Keyword(s):  
Body Composition ◽  
Body Fat ◽  
Total Body Water ◽  
Body Water ◽  
The Body ◽  
Water Volume ◽  
Plasma Urea ◽  
Space Technique ◽  
Total Body

San Pietro and Rittenberg (1953) reported that urea appeared to meet all the requirements of a satisfactory tracer. Urea is non toxic, not foreign to the body and it shows an even and rapid distribution throughout the total body water without any physiological effect. For these reasons in addition to its easy and accurate measurement, urea is an ideal candidate tracer to estimate empty body water in vivo. Total body water volume (urea space) can be estimated by dividing the total amount of urea infused by the increase in plasma urea concentration from prior to infusion until 12 or 30 minutes after mean infusion time. Kock and Preston (1973) reported significant relationships between urea space measurements and percentage of empty body fat and water in cattle. However, Andrew et al. (1995) using 21 Holstein cows showed that prediction of empty body water using the urea space technique only explained 31 % of the variation. The objective of this experiment was to use the urea dilution technique to estimate the body composition of lactating dairy cows and produce relationships between urea space and body fat and protein content.

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