Heats of combustion of the main carbohydrates contained in plant-source foods

2019 ◽  
Vol 78 (5) ◽  
pp. 382-393
Author(s):  
María Judith Sánchez-Peña ◽  
Ana Guadalupe Martínez-Navarro ◽  
Fabiola Márquez-Sandoval ◽  
Humberto Gutiérrez-Pulido ◽  
Fermín Paul Pacheco-Moisés ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Maximum Level ◽  
Metabolizable Energy ◽  
Heat Of Combustion ◽  
Calorimetric Data ◽  
Minimum Level ◽  
Plant Source ◽  
Rigorous Statistical Analysis ◽  
Bibliographic Search ◽  
Heats Of Combustion

Abstract In a previous review, the experiments of American chemist W.O. Atwater were critically examined, with the findings demonstrating certain weaknesses that could compromise the validity of the values currently used for metabolizable energy. An examination of published works on the heat of combustion of carbohydrates reveals 2 types of weaknesses: the inaccuracy and imprecision of the calorimetric data used, and the averaging procedure employed to estimate such representative values. The present review focuses on the first type of weakness, namely the inaccuracy and imprecision of the calorimetric data used in previous studies. An exhaustive bibliographic search yielded almost 100 heat of combustion values for some of the 6 main carbohydrates contained in plant-source foods (glucose, fructose, sucrose, maltose, starch, and cellulose). These heats of combustion were subjected to rigorous statistical analysis to propose the following for each carbohydrate: (1) an interval (termed a bibliographic interval) that very likely includes the actual heat of combustion value and (2) a “representative value” (calculated to produce the minimum level of inaccuracy). In addition, an estimation of the maximum level of inaccuracy that could be expected when using such a representative value is reported.

scholarly journals The energy equivalents of ATP and the energy values of food proteins and fats

1984 ◽  
Vol 51 (1) ◽  
pp. 15-28 ◽  
Author(s):  
Geoffrey Livesey
Keyword(s):  
Fatty Acid ◽  
Amino Acid ◽  
Oxidative Phosphorylation ◽  
G Protein ◽  
Compositional Data ◽  
Metabolizable Energy ◽  
Food Proteins ◽  
Protein Nitrogen ◽  
Food Composition Tables ◽  
Heats Of Combustion

1. Heats of combustion and energy equivalents of cytoplasmic ATP have been estimated for glucose, 101 food proteins and 116 food fats based on amino acid and fatty acid composition data from food composition tables and the heats of combustion and energy equivalents of cytoplasmic ATP of each individual amino acid, fatty acid, glycerol and glucose. The isodynamic equivalents of carbohydrate, fat and protein at the biochemical level have been investigated.2. Heats of combustion of food proteins and fats derived from compositional data were within 1 % of published values obtained by calorimetry.3. Cytoplasmic ATP equivalents for glucose, fat and protein range from 9·0 to 14·7, 8·6 to 14·6 and 6·4 to 13·2 mol cytoplasmic ATP/MJ of metabolizable energy respectively, depending on the choice of mitochondrial proton stoichiometries for these estimations. The range is extended further when considering the level and type of mitochondrial ‘uncoupling’.4. Isobioenergetic relationships between the efficiencies of glucose (G) and fat (F) (F = 1·05 G-0·9) and glucose and protein (P) (P = G(1·02–0·19f)-(1.8+0·5f)) energy conversions (wheref is the fraction of protein oxidized via gluconeogenesis) were obtained and were essentially independent of the choice of mitochondrial proton stoichiometry and the level and type of uncoupling of oxidative phosphorylation.5. Potential errors in previous estimates of ATP yield from protein are shown to be as much as -17·6 to < 118%; accounting for the efficiency of mitochondrial oxidative phosphorylation narrows this to between -7·9 and 17·4% and accounting for the fraction of protein oxidized via gluconeogenesis limits this further to between - 7·9 and 11·1%. Remaining uncertainty is attributed mostly to lack of knowledge about the energy cost of substrate absorption from the gut and transport across cell membranes.6. Coefficients of variation (cv) in the cytoplasmic ATP yield/g protein and /g protein nitrogen for the 101 food proteins were large (0·033 and 0·058 respectively). This is attributed mostly to variation in the metabolizable heats of combustion (cv 0·033 and 0·053 respectively) and to a much smaller extent in the efficiency with which cytoplasmic ATP equivalents are generated/MJ of metabolizable energy (cv 0·01).7. It is concluded that the current understanding of biochemical energy transduction is sufficient to permit only a crude estimate of the energy equivalents of cytoplasmic ATP but that these equivalents vary by less than 5% between both different food proteins and different food fats. Isobioenergetic equivalents for carbohydrates, fats and protein which could be applied to modify the Atwater conversion factors are possible but require first an accurate quantification of the energy equivalent of cytoplasmic ATP for glucose in vivo, and an indication that oxidative phosphorylation is similarly efficient in different individuals.

The state of the respiratory system of students in conditions of high-altitude hypoxia

2022 ◽  
pp. 22-28
Author(s):  
V. A. Anzorov ◽  
◽  
Svetlana Vasilievna Moryakina ◽  
Keyword(s):  
Respiratory System ◽  
Oxygen Deficiency ◽  
Young Men ◽  
Maximum Level ◽  
Female Students ◽  
The State ◽  
Minimum Level ◽  
Respiratory Capacity ◽  
Maximum Value ◽  
Middle Mountains

The article presents the results of studies on the influence of mountain hypoxia on the state of the students’ respiratory system. When exposed to oxygen deficiency, only the respiratory capacity of the lungs undergoes significant changes. For instance, the RC level in female students under the influence of hypoxia gradually increased in conditions of medium altitude, reaching the maximum value of 0.64 liters (P ˂ 0.05), and on the plain - 0.44 liters. The RC value in young men reached the highest value of 0.74 liters in mid-altitude conditions, and on the plains, it constitutes 0.56 liters. The highest respiration rate for young men of 18.2 movements per minute was noted at an altitude of 600 meters, and the lowest - 17.4 at an altitude of 170 m. The maximum level of respiratory capacity while inhaling in girls is 1.24 liters, detected at an altitude of 600 meters, and the minimum level of 1.18 liters is noted at 170 m. The value of respiratory capacity while exhaling among young men living in the Sharoi region increased to 2.32 liters, and for those from Grozny - 2.24 liters. The highest VC level in girls - 3.87 liters - was found in the middle mountains, and on the plains, it was 3.58 liters. The VC value in young men, gradually increasing, reaches the highest value under the conditions of the Sharoi region - 4.57 liters, and in Grozny it was 4.28.

Educational Interactive Multimedia Software: Can it Effectively Teach Engineering Concepts?

1999 ◽  
Author(s):  
Derek T. Reamon ◽  
Sheri D. Sheppard
Keyword(s):  
Statistical Analysis ◽  
Direct Current ◽  
Engineering Students ◽  
Interactive Multimedia ◽  
Educational Effectiveness ◽  
Multimedia Software ◽  
Teaching Techniques ◽  
Preference Group ◽  
Dc Motors ◽  
Rigorous Statistical Analysis

Abstract This paper provides a rigorous statistical analysis of the educational effectiveness of a curriculum module pertaining to direct current (DC) motors and motorized systems. Educational interactive multimedia software played an important role in the module, which also included lectures, a design project and other more traditional pedagogics. Pre- and post-tests were administered to measure learning during the module and individual test questions targeted specific areas of the curriculum to determine the contribution of the various resources to the entire learning environment. The data indicate that the module was indeed educationally successful and that the software contributed to the curriculum’s success. The module was particularly effective for promoting learning by female engineering students in the course and mitigated some discrepancies in prior knowledge. Students were also grouped into four preference groups based on analysis of students’ preference questionnaire responses. The data indicate that each preference group responded differently to the various teaching techniques employed in the curriculum.

Simultaneous analysis of families of sigmoidal curves: application to bioassay, radioligand assay, and physiological dose-response curves.

1978 ◽  
Vol 235 (2) ◽  
pp. E97 ◽  
Author(s):  
A DeLean ◽  
P J Munson ◽  
D Rodbard
Keyword(s):  
Statistical Analysis ◽  
Dose Response ◽  
Curve Shape ◽  
Response Curves ◽  
Pharmacological Studies ◽  
Rigorous Statistical Analysis ◽  
Efficient Data ◽  
Dose Response Curves ◽  
Physiological Dose ◽  
Efficient Data Analysis

Physiological and pharmacological studies of hormones, drugs, and neurotransmitters often generate families of sigmoidal dose-response curves. Optimally efficient data analysis should involve simultaneous description of all curves, rather than fitting each one individually. We have developed a general computerized method to describe the dose-response curves in terms of basal and maximal responses, ED50, and curve shape or steepness. This facile method permits rigorous statistical analysis, provides a basis for pooling of information from separate experiments, and allows one to test which characteristics are shared by various curves.

scholarly journals The heat of combustion of the urine of sheep and cattle in relation to its chemical composition and to diet

1966 ◽  
Vol 20 (3) ◽  
pp. 449-460 ◽  
Author(s):  
K. L. Blaxter ◽  
J. L. Clapperton ◽  
A. K. Martin
Keyword(s):  
Regression Analysis ◽  
Standard Deviation ◽  
Crude Protein ◽  
Metabolizable Energy ◽  
Heat Of Combustion ◽  
Crude Protein Content ◽  
Mean Values ◽  
Residual Standard Deviation ◽  
Analytical Errors ◽  
Cattle And Sheep

1. The results of over 500 determinations of the heat of combustion of the urine produced by cattle and sheep have been analysed statistically. 2. The analytical errors for nitrogen, carbon and heat of combustion were ±0.54, ±1.4 and ±2.2%. The error attached to an estimate of the heat of combustion of the urine produced by an individual sheep in 4 days was ± 10%.3. At the maintenance level of feeding, the heat of combustion of the urine (U kcal/ 100 kcal food) was related to the crude protein content of the diet (P%)by the equationU = 0.25P+1.6with a residual standard deviation of ±0.88 kcal/100 kcal.4. Regression analysis of the relation between the heat of combustion of urine and its N content showed significant differences with diet. The heat of combustion of the urine of sheep was 9.7 kcal/g C and of cattle 10.3 kcal/g C, and did not vary with diet. 5. It is shown that the variation in the heat of combustion of urine/g N and its relative constancy/g C arises largely from variation, from diet to diet, in the proportion of the N excreted as hippurate. 6. The results have been combined with the results of a similar analysis (Blaxter & Clapperton, 1965) of methane production by sheep to show that the ratio of metabolizable energy to digested energy varies very little from mean values of 0.82 for roughages, 0.85 for cereals and 0.79 for oilseed cakes and meals.

scholarly journals FACTORS OF SAFETY FOR THE DESIGN OF BREAKWATERS

1982 ◽  
Vol 1 (18) ◽  
pp. 125
Author(s):  
J.D. Mettam ◽  
J.G. Berry
Keyword(s):  
Statistical Analysis ◽  
Specific Gravity ◽  
Factor Of Safety ◽  
Hydraulic Model ◽  
Model Testing ◽  
Design Tool ◽  
Rigorous Statistical Analysis

This paper proposes to improve the safety of breakwaters by two important changes in the philosophy of design. When hydraulic model testing is used as a design tool the authors propose to reduce the specific gravity of the model breakwater to introduce a factor of safety in the prototype. They also recommend that the concept of testing for stability with the once in 50 year or once in 100 year wave should be replaced by a more rigorous statistical analysis to determine a design wave which has a probability of exceedence of no more than 5% in the lifetime of the structure.

scholarly journals THE SUITABILITY OF SEAWATER ON CONCRETING IN THE NIGER – DELTA ZONE

2019 ◽  
pp. 39-48
Keyword(s):  
Compressive Strength ◽  
Niger Delta ◽  
Mathematical Theory ◽  
Regression Models ◽  
Cement Content ◽  
Suitable Condition ◽  
Maximum Level ◽  
Minimum Level ◽  
Concrete Compressive Strength ◽  
Factorial Regression

This study was carried out in order to determine the suitability or otherwise of seawater for concreting. The study was carried out using the Box-Wilson symmetric composite plan B3, comprising 15 experimental points with 3 levels of treatment each. In accordance with the principle of the mathematical theory of experiment, multi-factorial regression models were evolved. The cement content at maximum level[x1 (+), water content at the minimum level [x2 (-)] and retarding admixture at minimum level of treatment [x3(-)] proved to be the most suitable condition for concreting. The result as follows were; Concrete slump: 60mm, Concrete density: 2450g/cm3, Concrete compressive strength: 22.56N/mm2, 26.65N/mm2 and 30.09N/mm2 for 7days, 14days and 28 days, respectively.

Heats of Combustion. I. The Heat of Combustion of Acetone.

1941 ◽  
Vol 45 (9) ◽  
pp. 1346-1359 ◽  
Author(s):  
C. Burke Miles ◽  
Herschel Hunt
Keyword(s):  
Heat Of Combustion ◽  
Heats Of Combustion

A new high precision calorimeter for the measurement of heats of combustion: and the heat of combustion of succinic acid

1955 ◽  
Vol 248 (938) ◽  
pp. 23-44 ◽  
Keyword(s):  
Succinic Acid ◽  
High Precision ◽  
Heat Of Combustion ◽  
Optimum Conditions ◽  
Precision Determination ◽  
Best Value ◽  
Heats Of Combustion ◽  
Time Required ◽  
High Precision Determination ◽  
Thermal Steady State

The construction, calibration and use of a high-precision bomb calorimeter of the aneroid type are described. It consists of a stainless-steel combustion bomb as designed by Garlton-Sutton (I933) in a mantle of aluminium alloy, the temperature of which is measured by a platinumresistance thermometer. A simple means of measuring the electrical ignition energy has been devised. Because the time required for the attainment of a thermal steady state is greater for this type than for the conventional water calorimeter, the theory underlying methods of allowing for heat loss from the calorimeter to its surroundings has been critically re-examined, and the limitations of the commonly used Dickinson method (1914) have been clearly stated. For high precision to be attained, it proves to be particularly necessary that the conditions under which calibrations and measurements are performed shall be as similar as possible. Working under optimum conditions, chosen after systematic trials, it is possible to reduce to 0.012 % the standard deviation of the values for the calibration constant, with benzoic acid as the standard substance. The heat of combustion of succinic acid has been redetermined as — A.US = 3020-57 +0-43 cal/g (vac.). This agrees very well with the high-precision determination by Huffmann (1938) 3020-47 ± 0.43. Succinic acid is suitable as a secondary standard for combustion calorimetry; and the best value is taken to be 3020.5 ± 0.5 cal/g (vacj <.

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