Computer Simulation of Radiant Heat Load and Control Alternatives

AIHAJ ◽  
1974 ◽  
Vol 35 (2) ◽  
pp. 75-83 ◽  
Author(s):  
ROBERT L. HARRIS
Keyword(s):  
Computer Simulation ◽  
Heat Load ◽  
Radiant Heat ◽  
And Control

scholarly journals Evaluation and Control of Radiant Heat Load in Open-type Dairy Barns

1984 ◽  
Vol 39 (4) ◽  
pp. 281-288 ◽  
Author(s):  
Masumi OKADA ◽  
Hideo MINAGAWA ◽  
Akihiro GONDO
Keyword(s):  
Heat Load ◽  
Radiant Heat ◽  
Open Type ◽  
And Control

The influence of radiant heat load on reproduction in the Merino ewe. II. The relative effects of heating before and after insemination

1979 ◽  
Vol 30 (6) ◽  
pp. 1143 ◽  
Author(s):  
GJ Sawyer
Keyword(s):  
Reproductive Performance ◽  
Artificial Insemination ◽  
Vapour Pressure ◽  
Heat Load ◽  
Radiant Heat ◽  
Control Room ◽  
Respiration Rates ◽  
Before And After ◽  
And Control ◽  
Group 1

The effect of radiant heat load imposed both before and after artificial insemination (AI) on the reproductive performance of Merino ewes was tested in two experiments. In the first experiment ewes were allocated to four groups: controls (group 1); hot-room conditions for 5.5 days prior to AI (day 0) (groups 2 and 4); hot-room conditions for days 1–9 after AI (groups 3 and 4). Ewes in the second experiment were allocated to three groups: controls (group 1); hot-room conditions for 5.5 days prior to AI then for days 1–4 after AI and days 5–8 after AI (groups 2 and 3 respectively). Hot-room conditions for both experiments ranged over 41–43°C and 2.07–3.08 kPa vapour pressure, and control room conditions over 22–27°C and 1.19–2.10 kPa. When subjected to hot-room conditions the rectal temperatures and respiration rates for all heated ewes were significantly higher than those of controls by c. 1.0°C and 120 respirations/min. In both experiments the number of ewes exhibiting oestrus was significantly reduced by about one-third following heating. Despite this most ewes ovulated. Heated ewes which showed oestrus in experiment 2 had significantly longer oestrous cycles than control ewes (17.9 days v. 16.9 days, P < 0.01). In this experiment lack of cyclical oestrous activity was the main cause of reduced fertility in heated ewes. The number of ewes lambing was depressed in heated ewes in both experiments, but was affected most severely in experiment 1. In this experiment the poorest lambing performance of 21.5% compared with 70.6% in controls resulted from heating both before and after insemination. Interference with cyclical oestrous activity by exposure to a high radiant heat load at the time of insemination (either natural or artificial) may contribute significantly to reproductive wastage associated with ewes which mate, apparently conceive, but fail to lamb.

scholarly journals Model of 2,3-bisphosphoglycerate metabolism in the human erythrocyte based on detailed enzyme kinetic equations1: computer simulation and Metabolic Control Analysis

1999 ◽  
Vol 342 (3) ◽  
pp. 597-604 ◽  
Author(s):  
Peter J. MULQUINEY ◽  
Philip W. KUCHEL
Keyword(s):  
Computer Simulation ◽  
Metabolic Control ◽  
Energy Demand ◽  
Feedback Inhibition ◽  
Oxygen Affinity ◽  
Metabolic Control Analysis ◽  
Product Inhibition ◽  
Control Analysis ◽  
And Control

This is the third of three papers [see also Mulquiney, Bubb and Kuchel (1999) Biochem. J. 342, 565-578; Mulquiney and Kuchel (1999) Biochem. J. 342, 579-594] for which the general goal was to explain the regulation and control of 2,3-bisphosphoglycerate (2,3-BPG) metabolism in human erythrocytes. 2,3-BPG is a major modulator of haemoglobin oxygen affinity and hence is vital in blood oxygen transport. A detailed mathematical model of erythrocyte metabolism was presented in the first two papers. The model was refined through an iterative loop of experiment and simulation and it was used to predict outcomes that are consistent with the metabolic behaviour of the erythrocyte under a wide variety of experimental and physiological conditions. For the present paper, the model was examined using computer simulation and Metabolic Control Analysis. The analysis yielded several new insights into the regulation and control of 2,3-BPG metabolism. Specifically it was found that: (1) the feedback inhibition of hexokinase and phosphofructokinase by 2,3-BPG are equally as important as the product inhibition of 2,3-BPG synthase in controlling the normal in vivo steady-state concentration of 2,3-BPG; (2) H+ and oxygen are effective regulators of 2,3-BPG concentration and that increases in 2,3-BPG concentrations are achieved with only small changes in glycolytic rate; (3) these two effectors exert most of their influence through hexokinase and phosphofructokinase; (4) flux through the 2,3-BPG shunt changes in absolute terms in response to different energy demands placed on the cell. This response of the 2,3-BPG shunt contributes an [ATP]-stabilizing effect. A ‘cost’ of this is that 2,3-BPG concentrations are very sensitive to the energy demand of the cell and; (5) the flux through the 2,3-BPG shunt does not change in response to different non-glycolytic demands for NADH.

Measurement of Radiant Heat Load on Man in Summer and Winter Alaskan Climates

1954 ◽  
Vol 7 (2) ◽  
pp. 200-211 ◽  
Author(s):  
James D. Hardy ◽  
Alice M. Stoll
Keyword(s):  
Heat Load ◽  
Radiant Heat

Modelling and Performance Assessment of an Antenna-Control System

1982 ◽  
Vol 104 (1) ◽  
pp. 41-48
Author(s):  
C. R. Burrows
Keyword(s):  
Computer Simulation ◽  
Energy Transfer ◽  
Control System ◽  
Qualitative Data ◽  
Regenerative Braking ◽  
General Interest ◽  
Continuous Control ◽  
And Performance ◽  
And Control ◽  
Search Capability

An assessment is made of a surveillance-radar control system designed to provide a sector-search capability and continuous control of antenna speed without unwanted torque-reaction on the supporting mast. These objectives are attained by utilizing regenerative braking, and control is exercised through Perbury CVTs. A detailed analysis of the system is given. The models derived for the Perbury CVTs supplement the qualitative data contained in earlier papers. Some results from a computer simulation are presented. Although the paper is concerned with a particular problem, the analysis of the CVTs, and the concept of using energy transfer to control large inertial loads, are of more general interest.

Dynamic Workspace and Control of Planar Active Tensegrity-Like Structures

2008 ◽  
Author(s):  
Andrew P. Schmalz ◽  
Sunil K. Agrawal
Keyword(s):  
Computer Simulation ◽  
Feedback Linearization ◽  
Null Space ◽  
System Dynamic ◽  
Initial Configuration ◽  
Dynamic Equations ◽  
Entire System ◽  
Tensegrity Structures ◽  
And Control

This paper addresses the issues of control and workspace determination of planar active tensegrity or tensegrity-like structures. The motion of such structures is generally produced by actuated cables, which cannot tolerate compressive forces. Hence, a controller which not only satisfies the system dynamic equations, but also maintains positive tension in cables is necessary. A null-space controller based on feedback linearization theory is developed for this purpose. This controller utilizes redundant active cables to overactuate the system. The concept of a ‘dynamic workspace’ for these structures is then introduced. This workspace consists of all configurations that are achievable from a given initial configuration while maintaining positive tensions throughout the entire system motion and is a powerful tool in analyzing the performance of a variety of tensegrity structures. This idea extends the concept of the static workspace, which consists of statically maintainable configurations, by incorporating system motion and dynamics to guarantee positive tensions during transition between the states. A critical benefit of this procedure is that it may be used to find the dynamic workspace of a system regardless of whether actuator redundancy is utilized, and thus can be used to objectively illustrate the degree to which overactuation improves mobility of a tensegrity structure. The effectiveness of the developed concepts is demonstrated through computer simulation and actual physical experimentation.

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