Development of a mobile, open-circuit indirect calorimetry system

1994 ◽  
Vol 74 (1) ◽  
pp. 65-71 ◽  
Author(s):  
J. M. Kelly ◽  
B. Kerrigan ◽  
L. P. Milligan ◽  
B. W. McBride
Keyword(s):  
Oxygen Consumption ◽  
Energy Metabolism ◽  
Indirect Calorimetry ◽  
Rapid Determination ◽  
Accurate Determination ◽  
Standard Test ◽  
Open Circuit ◽  
Absolute Pressure ◽  
Gas Temperature

A system for the rapid determination of O2 consumption, CO2 production and subsequent indirect estimation of energy metabolism of ruminants has been updated and validated. The accurate determination of gas temperature, relative humidity, absolute pressure and flow is important to the overall use of the system. Analogue outputs from the specific analyzers were multiplexed and then routed to a data acquisition system with appropriate software control. Subsequent data processing included modification to fit LOTUS 1-2-3 files. The analyzers were calibrated with standard test gases for the gas meters. In an experimental confirmation trial, eight sheep were fed at maintenance (M) or 2× maintenance (2M) or fasted 48 h after each level of intake (MF and 2MF, respectively) and subsequent energy metabolism was determined. Oxygen consumption (mL min−1), metabolic rate (W) and CO2 production (mL min−1) were greater (P < 0.05) for animals fed 2M (111.2, 379.5 and 101.9, respectively) than for those fed M (85.4, 291.2 and 86.1, respectively). Maintenance values were, in turn, also higher (P < 0.05) than those for either MF (56.7, 193.4 and 48.0, respectively) or 2MF (54.6, 186.4 and 46.3, respectively). M sheep had a higher respiratory quotient (1.03) (P < 0.05) than either MF sheep (0.86) or 2MF sheep (0.89), with 2M sheep being intermediate (0.95). There were no differences (P > 0.05) between the two fasted states for all parameters. Results from the confirmation experiment agree with previously published work and were consistent with those from similar systems. Key words: Indirect calorimetry, oxygen consumption, sheep

scholarly journals A calorimetry system for metabolism trials

2007 ◽  
Vol 59 (2) ◽  
pp. 495-500 ◽  
Author(s):  
N.M. Rodríguez ◽  
W.E. Campos ◽  
M.L. Lachica ◽  
I. Borges ◽  
L.C. Gonçalves ◽  
...  
Keyword(s):  
Heat Production ◽  
Indirect Calorimetry ◽  
Rapid Determination ◽  
Minas Gerais ◽  
Standard Test ◽  
Medium Size ◽  
O2 Consumption ◽  
Ch4 Production ◽  
Ad Libitum

An indirect calorimetry system for rapid determination of CO2 and CH4 production and O2 consumption to estimate heat production of animals was built at Escola de Veterinária da Universidade Federal de Minas Gerais, Brazil. Procedures for determination of correction and calibration factors for gas analyzers and the whole system, using standard test gases were described. In addition, a metabolic trial was performed to evaluate heat production of lambs fed ad libitum. It is concluded that the system is suitable for heat production determinations in small and medium size animals.

Study of a-Si:H / c-Si Heterojunctions for PV Applications

1996 ◽  
Vol 420 ◽  
Author(s):  
F. Zignani ◽  
R. Galloni ◽  
R. Rizzoli ◽  
M. Ruth ◽  
C. Summonte ◽  
...  
Keyword(s):  
Gas Phase ◽  
Open Circuit Voltage ◽  
Accurate Determination ◽  
Electrical Characterization ◽  
Silicon Layer ◽  
Open Circuit ◽  
Hydrogen Dilution ◽  
Intrinsic Efficiency

Abstracta-Si:H / c-Si heterojunction diodes were produced by PECVD with varying amorphous silicon layer thickness and hydrogen dilution of the gas phase. An accurate determination of the growth rate also in the initial stages of the deposition was made possible by an original chemical method based on the dissolution of the films followed by spectroscopical analysis of the obtained solution.The electrical characterization of the diodes confirms the generation - recombination - multitunneling nature of the transport. Although H2 dilution is important, however, beyond a certain level it is detrimental for the junction quality, probably due to the transition to a microcrystalline phase deposition. Solar cells were also produced, the best results being an open circuit voltage of 610 mV and an intrinsic efficiency of 14.2%.

scholarly journals Spectrum of the Anomalous Microwave Emission in the North Celestial Pole withWMAP7-Year Data

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Anna Bonaldi ◽  
Sara Ricciardi
Keyword(s):  
Accurate Determination ◽  
Peak Frequency ◽  
Microwave Emission ◽  
Neutral Medium ◽  
Gas Temperature ◽  
The North ◽  
Celestial Pole ◽  
Hydrogen Ionization ◽  
Component Separation Method

We estimate the frequency spectrum of the diffuse anomalous microwave emission (AME) on the North Celestial Pole (NCP) region of the sky with the Correlated Component Analysis (CCA) component separation method applied toWMAP7-yr data. The NCP is a suitable region for this analysis because the AME is weakly contaminated by synchrotron and free-free emission. By modeling the AME component as a peaked spectrum we estimate the peak frequency to be21.7±0.8 GHz, in agreement with previous analyses which favoredνp< 23 GHz. The ability of our method to correctly recover the position of the peak is verified through simulations. We compare the estimated AME spectrum with theoretical spinning dust models to constrain the hydrogen densitynH. The best results are obtained with densities around 0.2–0.3 cm−3, typical of warm ionised medium (WIM) to warm neutral medium (WNM) conditions. The degeneracy with the gas temperature prevents an accurate determination ofnH, especially for low hydrogen ionization fractions, where densities of a few cm−3are also allowed.

Rapid determination of whole-body bicarbonate kinetics by use of a digital infusion

1984 ◽  
Vol 247 (4) ◽  
pp. R709-R716 ◽  
Author(s):  
C. S. Irving ◽  
W. W. Wong ◽  
W. M. Wong ◽  
T. W. Boutton ◽  
R. J. Shulman ◽  
...  
Keyword(s):  
Kinetic Parameters ◽  
Rapid Determination ◽  
Accurate Determination ◽  
Substrate Oxidation ◽  
Whole Body ◽  
Constant Infusion ◽  
External Control ◽  
Base Line ◽  
Oxidation Rates

Accurate determination of substrate oxidation rates from breath 13CO2 levels often requires information on the bicarbonate status of the subject. We have developed a rapid method to obtain a complete set of bicarbonate kinetic parameters, prime bicarbonate pools with 13C, clamp breath 13CO2 levels rapidly and accurately with predetermined ranges, and provide a steady base-line enrichment of 13C for a subsequent substrate oxidation measurement. The method consists of administering NaH13CO3 intravenously as a combination of a bolus dose, an exponentially decreasing infusion, and a constant infusion. A Harvard model 2729 microprocessor-controlled syringe pump was modified for external control and coupled to a Hewlett-Packard HP-85 desk-top computer to deliver the complex infusion. An infusion algorithm that would rapidly attain and maintain an increase of 50% 13C enrichment of breath CO2 was derived by using the SAAM-27 program to interrogate a three-compartmental model of bicarbonate kinetics in normal, fasted, resting adult subjects. When the method was tested on five adult fasted subjects who had rested for 1.5 h, plateau enrichments were achieved within 10–20 min. The bicarbonate pool sizes and kinetic parameters obtained by compartmental analysis of their 13CO2 data were used to obtain a refined infusion protocol, which resulted in more rapid attainment of plateau enrichments. If carried out immediately before a substrate oxidation test, the method can provide a complete description of bicarbonate kinetics for use in the compartmental and noncompartmental analysis of substrate catabolism.(ABSTRACT TRUNCATED AT 250 WORDS)

Validation of open-circuit method for the determination of oxygen consumption.

1973 ◽  
Vol 34 (6) ◽  
pp. 859-863 ◽  
Author(s):  
J A Wagner ◽  
S M Horvath ◽  
T E Dahms ◽  
S Reed
Keyword(s):  
Oxygen Consumption ◽  
Open Circuit

scholarly journals The respiratory quotient in the newborn pig

1969 ◽  
Vol 23 (2) ◽  
pp. 407-413 ◽  
Author(s):  
L. E. Mount
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Energy Metabolism ◽  
Respiratory Quotient ◽  
Carbon Dioxide Production ◽  
Mean Value ◽  
Open Circuit ◽  
Mean Values ◽  
The Mean ◽  
Environmental Temperatures

1. Rates of oxygen consumption and carbon dioxide production were measured in pigs from birth to 3 days of age in an open-circuit system.2. The mean respiratory quotient (RQ) during the first 6 h following birth was 0.95 in fasted pigs and 0.91 in pigs which were allowed to feed.3. The RQ fell during the remainder of the first postnatal day to mean values close to 0.85, whether the pigs were allowed to feed from birth or were fasted.4. From 1 to 3 days of age the RQ had a mean value of 0.79.5. There was little difference in the RQ of pigs exposed to environmental temperatures of either 32 or 16°.6. It is concluded that the baby pig is not exclusively dependent on carbohydrate for its energy metabolism.

Rapid Determination of Ammonia in a Perchloric Acid Supernate from Blood, by Use of an Ammonia-Specific Electrode

1973 ◽  
Vol 19 (10) ◽  
pp. 1162-1169 ◽  
Author(s):  
Henning F Proelss ◽  
Billy W Wright
Keyword(s):  
Perchloric Acid ◽  
Rapid Determination ◽  
Clinical Status ◽  
Accurate Determination ◽  
Ammonia Nitrogen ◽  
Blood Proteins ◽  
Exchange Method ◽  
Time Required ◽  
Sensitivity Specificity

Abstract A simple, rapid method was developed for accurate determination of ammonia in whole blood. Blood proteins were precipitated with perchloric acid (8 g/dl) and the free ammonia liberated in the supernate on alkalinization was measured directly with an ammonia-specific electrode after adjusting the sample temperature to 25 °C. Some variables affecting precision, accuracy, and electrode performance were studied. Sensitivity, specificity, and interferences are discussed. The tentative normal range is 28 ± 14 µg of ammonia nitrogen per deciliter. The coefficient of variation was 4.8% in the "normal," 3.6% in the "abnormal" range. Abnormal values were correlated with clinical status. Recoveries averaged 99.3%. Correlation with an established ion-exchange method for plasma ammonia was 0.994. Total time required for a complete assay is 15 min.

scholarly journals Rapid determination of 26 elements in iron meteorites using matrix removal and membrane desolvating quadrupole ICP-MS

2014 ◽  
Vol 29 (12) ◽  
pp. 2379-2387 ◽  
Author(s):  
Xiaoxia Duan ◽  
Marcel Regelous
Keyword(s):  
Rapid Determination ◽  
Accurate Determination ◽  
Iron Meteorites ◽  
Icp Ms ◽  
Matrix Removal

Rapid and accurate determination of 26 elements in iron meteorites by Q-ICPMS.

Rapid determination of the gas temperature in magnetooptical traps

2016 ◽  
Vol 61 (9) ◽  
pp. 1439-1441 ◽  
Author(s):  
A. A. Kalinichev ◽  
E. N. Borisov ◽  
A. V. Povolotskiy ◽  
T. Yu. Ivanova ◽  
D. A. Ivanov
Keyword(s):  
Rapid Determination ◽  
Gas Temperature
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