Determination of body density by the hydrostatic weighting: Dynamometer versus load cell

2009 ◽  
Author(s):  
Carlos M. P. Cursino ◽  
Raimundo C. S. Freire ◽  
Joao B. A. Silva ◽  
Enilson J. L. Costa ◽  
Sebastian Y. Catunda ◽  
...  
Keyword(s):  
Load Cell ◽  
Body Density

Age trends in fat in normal and obese children

1961 ◽  
Vol 16 (1) ◽  
pp. 173-174 ◽  
Author(s):  
Jana Pařízková
Keyword(s):  
Sexual Difference ◽  
Fat Content ◽  
Dilution Method ◽  
Body Density ◽  
Obese Children ◽  
Normal Children ◽  
Nitrogen Dilution ◽  
Hydrostatic Weighing ◽  
Age Trends

Body density was determined in 151 normal boys and girls 9–17 years old by hydrostatic weighing and simultaneous determination of residual lung volume by the nitrogen dilution method. Also, 56 obese children 9–15 years old were studied. Body composition changed characteristically in the groups of normal children. In boys, density at 9 years was 1.062 (S.E. = 0.003) and fell to 1.048 (S.E. = 0.004) at 11–13 years; it rose to 1.073 (S.E. = 0.002) at 16, indicating a relative decrease in fat content and increased development of lean body mass. In girls, values were more stable-1.041–1.042 (S.E. = 0.003–0.004) on the average, except in the year 13–14 when body density increased to 1.051 (S.E. = 0.004). After the start of clinical puberty, body density again fell to 1.038 (S.E. = 0.003) indicating increased fat content. There was significant sexual difference in body density before the beginning of prepuberal acceleration of growth and later with the start of clinical puberty. Body density for obese boys 9–12 years old was 1.010 (S.E. = 0.002) and for obese girls of the same age 1.009 (S.E. = 0.002). In 13–15-year-old obese boys, density was 1.016 (S.E. = 0.003) and for girls was 1.012 (S.E. = 0.0039); i.e. in obese children no sex or age differences in body density were found. Submitted on May 9, 1960

scholarly journals Insights into one-body density matrices using deep learning

2020 ◽  
Vol 224 ◽  
pp. 265-291 ◽  
Author(s):  
Jack Wetherell ◽  
Andrea Costamagna ◽  
Matteo Gatti ◽  
Lucia Reining
Keyword(s):  
Deep Learning ◽  
Density Matrix ◽  
Reduced Density Matrix ◽  
Body Density ◽  
Density Matrices ◽  
Learning Constraints ◽  
The One ◽  
Reduced Density

Deep-learning constraints of the one-body reduced density matrix from its compressibility to enable efficient determination of key observables.

Anthropometric determination of body volume, body density and segmental volume in adult Indian women

1977 ◽  
Vol 4 (6) ◽  
pp. 565-575 ◽  
Author(s):  
Chand Raja ◽  
Raghbir Singh ◽  
H. Bharadwaj
Keyword(s):  
Body Volume ◽  
Body Density ◽  
Indian Women

DETERMINATION OF BODY DENSITY BY AIR DISPLACEMENT, HELIUM DILUTION, AND UNDERWATER WEIGHING*

2006 ◽  
Vol 110 (1) ◽  
pp. 96-108 ◽  
Author(s):  
R. H. Gnaedinger ◽  
E. P. Reineke ◽  
A. M. Pearson ◽  
W. D. Van HUSS ◽  
Janet A. Wessel ◽  
...  
Keyword(s):  
Body Density ◽  
Helium Dilution

Chemical determination of human body density in vivo: relevance to hydrodensitometry

1989 ◽  
Vol 50 (6) ◽  
pp. 1282-1289 ◽  
Author(s):  
S B Heymsfield ◽  
J Wang ◽  
J Kehayias ◽  
S Heshka ◽  
S Lichtman ◽  
...  
Keyword(s):  
Human Body ◽  
Body Density ◽  
Chemical Determination

scholarly journals LISÍMETROS DE PESAGEM PARA MEDIDAS DE EVAPOTRANSPIRAÇÃO EM ESTUFA

Irriga ◽  
2017 ◽  
Vol 22 (4) ◽  
pp. 715-722
Author(s):  
Izabela Paiva Martins ◽  
Rogério Teixeira De Faria ◽  
Luiz Fabiano Palaretti ◽  
Alexandre Barcellos Dalri ◽  
Carolina Oliverio ◽  
...  
Keyword(s):  
Water Balance ◽  
Storage System ◽  
Absolute Error ◽  
Load Cell ◽  
Calibration Data ◽  
Mass Variation ◽  
Water Balance Components ◽  
E Mail

LISÍMETROS DE PESAGEM PARA MEDIDAS DE EVAPOTRANSPIRAÇÃO EM ESTUFA  IZABELA PAIVA MARTINS; ROGÉRIO TEIXEIRA DE FARIA; LUIZ FABIANO PALARETTI; ALEXANDRE BARCELLOS DALRI; CAROLINA OLIVERIO E LUIS GUILHERME POLIZEL LIBARDI Departamento de Engenharia Rural, Universidade Estadual Paulista - Campus Jaboticabal, Via de Acesso Professor Paulo Donato Castelane, Vila Industrial, Jaboticabal, Sp, Brasil. E-mail: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected].   1 RESUMO Lisímetros de pesagem são utilizados com a finalidade de determinar os componentes do balanço hídrico, particularmente a evapotranspiração e a evaporação. Dentre as inúmeras metodologias, esta apresenta maior precisão, porém, para a obtenção de dados confiáveis, sua calibração deve ser executada in situ. Esse trabalho objetivou calibrar 12 lisímetros de pesagem, verificar a presença de linearidade e histerese das medidas, e avaliar a precisão dos equipamentos. Os lisímetros apresentavam diâmetro e profundidade de 30 cm, com uma célula de carga em cada lisímetro para a determinação da variação de massa, acoplada a um sistema de aquisição e armazenamento de dados. A calibração foi realizada comparando-se a adição e remoção de pesos com massa conhecida (em kg) com a leitura da célula de carga (em mV). Os dados de calibração foram lineares, apresentando correlação significativa da massa em resposta a voltagem. Os coeficientes angular e linear variaram de 762,78 a 1187,8 kg mV-1 e -444,99 a -798,00 kg, respectivamente. O erro absoluto variou de 0,03 a 0,54, mostrando alta precisão dos lisímetros. A precisão constatada na obtenção da variação da massa foi de 0,79 mm, com o índice de concordância de Willmott foi de 0,99, mostrando a concordância entre os valores estimados e os observados. Conclui-se que os lisímetros são adequados para a determinação da evapotranspiração de cultivo. Palavras-chave: lisimetria, célula de carga, balanço hídrico  MARTINS, I. P.; FARIA, R. T. de; PALARETTI, L. F.; DALRI, A. B.; OLIVERIO, C.; LIBARDI, L. G. P.WEIGHING LYSIMETERS FOR GREENHOUSE EVAPOTRASPIRATION MEASUREMENTS  2 ABSTRACT Weighing lysimeters are used for the purpose of determining water balance components, especially for evapotranspiration and evaporation. Within all know methods, lysimeter is considered the most accurate, but in order to obtain reliable data, their calibration must be performed in situ. The objective of this work was to calibrate 12 lysimeters to verify measurements’ linearity and the existence of hysteresis, besides evaluating the equipment's accuracy. The lysimeters had diameter and depth of 30 cm, with one load cell in each lysimeter for determination of mass variation,  connected to a data acquisition and storage system. The calibration was performed by comparing the load and unload know mass (kg) with the load cell reading (mV). The calibration data were linear, presenting a significant mass correlation in response to voltage. The angular and linear coefficients varied from 762.78 to 1187.8 kg mV-1 and -499.99 to -798.00 kg, respectively. The absolute error ranged from 0.03 to 0.54, showing a high accuracy of the lysimeters. The accuracy for mass variation was 0.79 mm and the Willmott concordance index was 0.99, showing the good agreement between the estimated and observed values. It can be concluded that lysimeters are suitable for crop evapotranspiration determination. Keywords: lisimetry, load cell, water balance 

scholarly journals Measurement of total body water using 2H dilution: impact of different calculations for determining body fat

2002 ◽  
Vol 88 (3) ◽  
pp. 325-329 ◽  
Author(s):  
J. LaForgia ◽  
R. T. Withers
Keyword(s):  
Body Composition ◽  
Body Fat ◽  
Total Body Water ◽  
Small Difference ◽  
Small Body ◽  
Body Water ◽  
Body Density ◽  
Total Body ◽  
Standard Calculation

This study estimated total body water (TBW) in four groups (twelve per group; sedentary and highly trained men and women) at the time of 2H dosing (T0) and after a 3·5 h equilibration period (Teq). Standard TBW calculations were employed at T0 (no correction for disproportionate urinary tracer loss) and Teq (correction for urinary tracer loss only), plus those calculations that corrected for a disproportionate urinary tracer loss and insensible tracer loss respectively. The measurement of body density enabled the four TBW estimates to be compared for the determination of three-compartment % body fat (BF). The very small difference between the standard and corrected T0 TBW data was not significant (P=0·914) and no Group×TBW interaction was identified (P=0·125). These results reflect the closeness of the 2H concentration in the urine produced during the equilibration period and the Teq saliva samples. The associated mean % BF values were essentially identical. Although correcting for insensible 2H losses in addition to urinary losses at Teq produced a statistically significant (P<0·001) lower mean TBW (about 200 g) than the standard calculation, this translated to a small difference in % BF (0·3). The larger difference (about 500 g, P<0·001) between the two (T0, Teq) corrected TBW calculations was also associated with a small body composition difference (0·1 % BF), which was less than the propagated error (0·3 % BF) for the three-compartment body composition model. Corrections to the standard calculations of TBW at T0 and Teq for a protocol employing a brief equilibration period (3·5 h) were therefore of marginal use for improving the accuracy of % BF estimates. The TBW difference over time (T0v. Teq) also had little impact on % BF values.

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