Experimental Investigation on the Influence of Ambient Temperature on the Test Accuracy for the Differential Pressure Hydrostatic Levelling System

Hydrostatic levelling system (HLS) is widely used to monitor the settlement of major projects, such as high-speed railways, bridges, tunnels, dams, and nuclear power plants; ambient temperature is the most important influencing factor in the actual engineering settlement detection process. In order to systematically study the influence of ambient temperature TA on the test accuracy of the HLS, a test platform was built in the ambient temperature laboratory, and the influence of factors, including the amount of TA change, the rate of increase/decrease of TA, the expansion coefficient of the connecting pipe, and the distance of the measuring point, on the HLS test accuracy was quantitatively analyzed. The test results show that the elevation of a single HSL case has a linear correlation with the ambient temperature; when the temperature rise rate is greater than 0.1°C/min, the measured data are distorted due to incomplete development of material expansion. The temperature influence coefficient of a single HSL case is linearly related to the expansion coefficient deviation between the refrigerant and pipe; the test error of the double HLS case caused by TA is attributed to the expansion coefficient deviation of the pipe and the refrigerant between the base station and the measuring point. The relative temperature influence coefficient increases as distance measurement increases, and the HLS test error caused by TA will maintain a constant value when the distance measurement exceeds a certain value.

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How to correct the ambient temperature influence on the thermal response test results

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2015.02.050 ◽

2015 ◽

Vol 82 ◽

pp. 39-47 ◽

Cited By ~ 15

Author(s):

Roque Borinaga-Treviño ◽

Jose Norambuena-Contreras ◽

Daniel Castro-Fresno

Keyword(s):

Ambient Temperature ◽

Thermal Response ◽

Thermal Response Test ◽

Test Results ◽

Temperature Influence ◽

Response Test

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Creep Instability of Ice Sheets

Journal of Glaciology ◽

10.1017/s0022143000031622 ◽

1976 ◽

Vol 16 (74) ◽

pp. 278-279

Author(s):

Garry K.C. Clarke

Keyword(s):

Melting Point ◽

Ambient Temperature ◽

Finite Thickness ◽

Wave Number ◽

Slab Thickness ◽

Perturbation Equation ◽

Rate Of Increase ◽

The Stability ◽

Image Position ◽

Advection Velocity

Abstract The equation governing the growth or decay of a temperature perturbation T’ in an ice slab under shear stress σ xy is where K and k are respectively the thermal conductivity and diffusivity of ice, KB-v is the advection velocity normal to the bed and is the rate of increase of strain heating with temperature assuming a power law for flow. For a slab of infinite thickness under constant stress and at constant ambient temperature, T Fourier analysis gives -k2+a/k < o as the condition for stability where k is the wave number of a sinusoidal perturbation. When the slab has finite thickness the stability depends on the sign of the eigenvalues λm of the perturbation equation and on the boundary condition at the ice-rock interface. In general the eigenfunctions and eigenvalues must be found by approximate methods such as the Rayleigh-Ritz procedure but in the case where the stress and ambient temperature are constant over the slab thickness and there is no advection the eigenfunctions are either sines or cosines depending on the boundary conditions. In this special case the stability condition is if the bed is frozen and if it is at the melting point. The eigenvalue associated with the smallest value of m is the least stable so the maximum stable thickness is thus h = ½ π(a/K)1/2 if the bed is frozen or h = π (a/K)1/2 if it is at the melting point. For typical flow-law parameters these depths are around 250 m and 500 m respectively. The eigenvalues are related in a simple way to the growth or decay rates of the eigenfunctions: (K λm)–1 is the time constant for the mth eigenfunction. Depth-dependent stress, temperature, and advection have a marked effect on stability. A slab in which stress and temperature increase to values B and T B at the bed is considerably more stable than a slab held at constant stressσB and a constant temperature T B. Advection normal to the bed also has a major influence on stability. If the advection velocity is taken to vary linearly with depth and the bed is frozen, the effect of upward advection is to decrease stability and of downward advection to increase it. When the bed is temperate the effect of advection is more complex: downward advection increases stability but upward advection may increase or decrease it depending on the magnitude of the advection velocity.

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STUDY ON RADON CONCENTRATION VARIATION DURING SUBWAY CONSTRUCTION

Radiation Protection Dosimetry ◽

10.1093/rpd/ncaa168 ◽

2020 ◽

Vol 191 (4) ◽

pp. 409-422

Author(s):

Bo Tan ◽

Guangyuan Yang ◽

Shuhui Fu ◽

Cheng Xu

Keyword(s):

Ambient Temperature ◽

Radon Concentration ◽

Comprehensive Analysis ◽

Subway Station ◽

Underground Space ◽

Measuring Point ◽

Low Level ◽

Subway Construction ◽

Under Construction ◽

High Level

Abstract The high radon concentration in the underground space of the subway station during construction often endangers the health of workers. Subway station project No. 16 in Beijing, while under construction, was selected as the main measuring point, a year’s monitoring data was obtained to analyse the change of radon concentration. It was found that the concentration of radon was basically within the range of 5 ~ 500 Bq/m3 and showing a low level in the morning and a high level at noon, and presents the seasonal rule, compared with other seasons, the summer radiation is stronger. Furthermore, among the different measuring points, the radon concentration of the heading roadway is the highest, and the construction level of the station hall is the lowest. According to the comprehensive analysis, the concentration of radon during the construction of the subway station is mainly affected by the ambient temperature and air mobility.

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Changes in Barometric Pressure and Ambient Temperature Influence Osteoarthritis Pain

The American Journal of Medicine ◽

10.1016/j.amjmed.2006.07.036 ◽

2007 ◽

Vol 120 (5) ◽

pp. 429-434 ◽

Cited By ~ 63

Author(s):

Tim McAlindon ◽

Margaret Formica ◽

Christopher H. Schmid ◽

Jeremiah Fletcher

Keyword(s):

Ambient Temperature ◽

Barometric Pressure ◽

Temperature Influence ◽

Osteoarthritis Pain

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An Analysis of Pre-Flight Warm-Up in the Sphinx Moth, Manduca Sexta

Journal of Experimental Biology ◽

10.1242/jeb.55.1.223 ◽

1971 ◽

Vol 55 (1) ◽

pp. 223-239 ◽

Cited By ~ 1

Author(s):

BERND HEINRICH ◽

GEORGE A. BARTHOLOMEW

Keyword(s):

Ambient Temperature ◽

Manduca Sexta ◽

Heat Production ◽

Blood Circulation ◽

Cardiac Activity ◽

Warm Up ◽

Ambient Temperatures ◽

Thoracic Temperature ◽

Wing Vibration ◽

Rate Of Increase

The physiology of pre-flight warm-up in Manduca sexta was analysed with regard to rate of heat production, regional partitioning of heat between thorax and abdomen, and the control of blood circulation. 1. When moths which have come to equilibrium with ambient temperature undergo pre-flight warm-up, the thoracic temperature increases linearly until flight temperature (37-39 °C) is approached. 2. The rate of increase in thoracic temperature during warm-up increases directly with ambient temperature from about 2 °C/min at 15 °C to about 7.6 °C/min at 30 °C. 3. The temperature of the abdomen remains near ambient throughout the period of warm-up, but during the initial part of post-flight cooling while thoracic temperature declines sharply abdominal temperatures rise appreciably. 4. During warm-up the rate of wing vibration increases linearly with thoracic temperature. At a thoracic temperature of 15 °C the rate is about 8/sec and at 35 °C it is about 25/sec. 5. When resting animals are held by the legs they at once begin to beat their wings through a wide angle. These wing beats at any given thoracic temperature are slower than the wing vibrations characteristic of normal warm-up, but they cause thoracic temperature to increase at almost the normal rate. 6. The removal of thoracic scales causes a decrease in rate of warm-up, but in still air this does not prevent the moths from reaching flight temperature. 7. During cooling the rate of decrease in thoracic temperature is greater in live animals than in freshly killed ones. At any given difference between thoracic and ambient temperatures cooling rates are directly related to thoracic temperature. 8. In resting moths heart pulsations are usually variable with regard to rate, amplitude, rhythm, and sometimes direction, but the records of cardiac activity simultaneously obtained from thorax and abdomen show close correspondence. 9. During warm-up the records of changes in impedance from electrodes in the abdomen indicate that pulsations of the abdominal heart are either absent, greatly reduced, or at a frequency different from that simultaneously recorded from the thorax. 10. The calculated rate of heat production during warm-up is linearly related to thoracic temperature. 11. Our data are consistent with the assumption that heat produced in the thorax during warm-up is sequestered there by reduction in blood circulation between thorax and abdomen. 12. Rates of warm-up in insects are close to the values predicted on the basis of body weight from data on heterothermic birds and animals.

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The Optimization of Balancing Least Squares Influence Coefficient Method Based on Particle Swarm Optimization

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.105-107.56 ◽

2011 ◽

Vol 105-107 ◽

pp. 56-61 ◽

Cited By ~ 1

Author(s):

Xing Xing Wang ◽

Guo An Yang ◽

Ya Jun Fan

Keyword(s):

Particle Swarm Optimization ◽

Least Squares ◽

Particle Swarm ◽

Influence Coefficient ◽

Residual Vibration ◽

Swarm Optimization ◽

Measuring Point ◽

Influence Coefficient Method ◽

Rotor Balancing ◽

Coefficient Method

On the basis of the rotor dynamic balancing theory, the rotor balancing least squares influence coefficient method has been discussed in detail in this paper. In order to solve the problem that the residual vibration in some of the measuring point and the balancing weight are comparatively large in the balance process with least squares influence coefficient method, particle swarm optimization algorithm with cross-factor, which is an improved swarm intelligence algorithm, is introduced into rotor balancing least squares influence coefficient method. Theoretical analysis and numerical examples show that the algorithm has a good convergence, with reducing the balancing weight and residual vibration effectively compared with basic least squares influence coefficient method. The result can achieve better balance effect in the rotor balancing process.

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Ambient temperature influence on catalytic outlet—inlet temperature difference

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1243/0954407001527259 ◽

2000 ◽

Vol 214 (1) ◽

pp. 95-100 ◽

Cited By ~ 3

Author(s):

P. N. Botsaris ◽

P. D. Sparis

Keyword(s):

Ambient Temperature ◽

Temperature Difference ◽

Inlet Temperature ◽

Temperature Influence

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Analysis of an ambient temperature influence on the thermal thin-film microsensor

Sensors and Actuators A Physical ◽

10.1016/0924-4247(94)00832-9 ◽

1994 ◽

Vol 45 (3) ◽

pp. 169-172 ◽

Cited By ~ 6

Author(s):

T.M. Berlicki ◽

E. Murawski ◽

S.J. Osadnik ◽

E.L. Prociów

Keyword(s):

Thin Film ◽

Ambient Temperature ◽

Temperature Influence

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Fall condition factor and temperature influence the incidence of metamorphosis in sea lampreys, Petromyzon marinus

Canadian Journal of Zoology ◽

10.1139/z94-151 ◽

1994 ◽

Vol 72 (6) ◽

pp. 1134-1140 ◽

Cited By ~ 42

Author(s):

John A. Holmes ◽

John H. Youson

Keyword(s):

Ambient Temperature ◽

Constant Temperature ◽

Temperature Regime ◽

Condition Factor ◽

Petromyzon Marinus ◽

Population Differences ◽

Temperature Influence ◽

Temperature Regimes ◽

Sea Lampreys ◽

Effects Of Temperature

Larval sea lampreys of immediate premetamorphic size (at least 120 mm and 3.0 g) were subjected to ambient or constant 21 °C temperature regimes for 9 months to investigate the influence of temperature and a fall condition factor (CF) of 1.50 or greater on the incidence of metamorphosis the following summer. The incidence of metamorphosis was 53% in the ambient temperature regime (29/55) and only 2% (1/55) in the constant temperature regime. About 64% (7/11) of the presumptively metamorphic larvae in the ambient temperature regime entered metamorphosis compared with 10% (1/10) in the constant temperature regime. Our predictions of metamorphosis based on CF were consistent with the observation that seven presumptively metamorphic larvae (CF ≥ 1.50) metamorphosed in the ambient temperature regime and that there was no metamorphosis among presumptively nonmetamorphic larvae in the constant temperature regime. Significantly more presumptively nonmetamorphic larvae in the ambient regime entered metamorphosis and fewer presumptively metamorphic larvae (CF < 1.50) metamorphosed in the constant temperature regime than expected. We attribute this response to the effects of temperature on metabolic processes. Larval sea lampreys of the appropriate size (≥ 120 mm and ≥ 3.0 g) with a CF of 1.50 or greater in the fall will usually enter metamorphosis the following July, but the accuracy of these predictions may be improved in some populations by using an empirically determined CF criterion that reflects seasonal or population differences in mass–length relationships.

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