Investigation and verification of the relationship between the average temperature of the circular section of the cooling water pipe and the maximum temperature of the section in the mass concrete

The key problem of mass concrete temperature control is to effectively control the maximum temperature inside concrete, the temperature difference between inside and outside concrete, and the temperature difference between surface and environment. The size of the main tower cap of No. 3 Jinsha River Bridge is 37 m × 23.5 m × 5.5 m, and the cubic volume of concrete reaches 4782.3 m3, which is poured in two times. In order to ensure construction quality of mass concrete structure, prevent the large mass concrete temperature stress, through the numerical simulation of the temperature control and optimization scheme, by optimizing the mixture ratio design, reducing the temperature of concrete pouring into the mold, cooling water cycling, insulation keeping in good health and a series of measures to effectively achieve the control goal, and eliminating the temperature cracks. The measured data show that the maximum temperature inside concrete, the temperature difference between inside and outside, and the temperature difference between surface and environment are qualified, but the temperature difference control of cooling water inlet and outlet has hysteresis effect, and the temperature difference between inlet and outlet will be greater than 10°C, which should be noticed.

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STUDY ON ARRANGEMENT OF COOLING WATER PIPE TO CONTROL HYDRATION HEAT OF CONCRETE IN BEAM OF CABLE-STAYED BRIDGE

Stavební obzor - Civil Engineering Journal ◽

10.14311/cej.2021.02.0039 ◽

2021 ◽

Vol 30 (2) ◽

Author(s):

Long Liu ◽

Saisai Yu ◽

Wentao Xu ◽

Zhilong Wang

Keyword(s):

Finite Element ◽

Flow Rate ◽

Water Flow Rate ◽

Cooling Water ◽

Hydration Heat ◽

Inlet Temperature ◽

Mass Concrete ◽

Water Pipe ◽

Finite Element Software ◽

Joint Section

The box girder joint section of the Yangtze River Highway Bridge is taken as the research background, and the finite element software MIDAS/FEA is used to simulate the hydration heat of concrete to the layout of cooling water pipe in building mass concrete. The finite element calculation results are in well agreement with the measured data. On this basis, the influence of changing the diameter and distance of the cooling water pipe, the inlet temperature and the flow rate on the temperature of hydration heat is studied. The results show diameter of the cooling water pipe and inlet temperature have a significant effect on the temperature of hydration heat. The change of water flow rate has little effect on the temperature of hydration heat. It provides a reference for the layout of the same concrete cooling water pipe arrangement.

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Relationship between Weather Variables and New Daily COVID-19 Cases in Dhaka, Bangladesh

Sustainability ◽

10.3390/su12208319 ◽

2020 ◽

Vol 12 (20) ◽

pp. 8319

Author(s):

M. Mofijur ◽

I.M. Rizwanul Fattah ◽

A.B.M. Saiful Islam ◽

M.N. Uddin ◽

S.M. Ashrafur Rahman ◽

...

Keyword(s):

Air Quality ◽

Minimum Temperature ◽

Rank Correlation ◽

Maximum Temperature ◽

Weather Variables ◽

Strong Negative Correlation ◽

Average Temperature ◽

Climate Indicators ◽

The Relationship ◽

Spearman Rank Correlation Test

The present study investigated the relationship between the transmission of COVID-19 infections and climate indicators in Dhaka, Bangladesh, using coronavirus infections data available from the Institute of Epidemiology, Disease Control and Research (IEDCR), Bangladesh. The Spearman rank correlation test was carried out to study the association of seven climate indicators, including humidity, air quality, minimum temperature, precipitation, maximum temperature, mean temperature, and wind speed with the COVID-19 outbreak in Dhaka, Bangladesh. The study found that, among the seven indicators, only two indicators (minimum temperature and average temperature) had a significant relationship with new COVID-19 cases. The study also found that air quality index (AQI) had a strong negative correlation with cumulative cases of COVID-19 in Dhaka city. The results of this paper will give health regulators and policymakers valuable information to lessen the COVID-19 spread in Dhaka and other countries around the world.

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Relationship between Climate Variables and New Daily COVID-19 Cases in Dhaka, Bangladesh

10.20944/preprints202007.0699.v1 ◽

2020 ◽

Author(s):

M. Mofijur ◽

Islam Md Rizwanul Fattah ◽

A. B. M. Saiful Islam ◽

S.M. Ashrafur Rahman ◽

Mohammad Asaduzzaman Chowdhury

Keyword(s):

Air Quality ◽

Wind Speed ◽

Minimum Temperature ◽

Maximum Temperature ◽

Dhaka City ◽

Climate Variables ◽

Average Temperature ◽

Climate Indicators ◽

The World ◽

The Relationship

The present study investigates the relationship between the transmission of COVID-19 infections and climate indicators in Dhaka City, Bangladesh, using coronavirus infections data available from the Institute of Epidemiology, Disease Control and Research (IEDCR), Bangladesh. The Spearman-ranked correlation test was carried out to study the association of seven climate indicators, including humidity, air quality, minimum temperature, precipitation, maximum temperature, mean temperature and wind speed with the COVID-19 outbreak in Dhaka City, Bangladesh. The study found that, among the seven indicators, only three indicators (air quality, minimum temperature and average temperature) have a significant relationship with new COVID-19 cases. The results of this paper will give health regulators and policymakers valuable information to lessen the COVID-19 infection in Dhaka and other countries around the world.

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The Design of Cooling Water Pipe and Cooling Analysis in Mass Concrete

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.255-260.3510 ◽

2011 ◽

Vol 255-260 ◽

pp. 3510-3513

Author(s):

Pan Wu Li ◽

Qian Qian Si

Keyword(s):

Heat Transfer Performance ◽

Cooling Water ◽

Mass Concrete ◽

Water Cooling ◽

Water Pipe ◽

External Temperature ◽

Concrete Cracking ◽

Massive Concrete ◽

Water Pipe Cooling ◽

Cooling Pipes

Inconstruction process of mass concrete is apt to form excessive temperature stress and cause mass concrete cracking, because of its high inner temperature, big internal and external temperature difference. In order to prevent their cracking, in mass concrete of the internal Settings with cooling water pipe cooling is one of the commonly used massive concrete construction method. This paper presents a massive concrete design of cooling water cooling and calculation theory, based on the cooling pipes in concrete heat transfer performance, through the cooling water pipe and concrete heat exchange principle.

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Quantum Biophysics of the Atmosphere:Factor Analysis of the Annual Dynamics of Maximum, Mininum and Average Temperatures from 1879 to 2017 to Hadley English Temperature Center (Hadcet)

Journal of Environmental & Earth Sciences ◽

10.30564/jees.v3i1.2489 ◽

2021 ◽

Vol 3 (1) ◽

Author(s):

Mazurkin Peter Matveevich

Keyword(s):

Factor Analysis ◽

Air Temperature ◽

Meteorological Parameter ◽

Dependent Measure ◽

Maximum Temperature ◽

Software Environment ◽

Average Temperature ◽

Average Annual Temperature ◽

Dynamics Models ◽

The Relationship

Factor analysis of annual dynamics from 1879 to 2017 was carried out by the method of identification of stable regularities: maximum, minimum and average air temperature of Central England according to HadCET. The sample capacity was 139 rows. In factor analysis, time is excluded, and it acts only as a system-forming factor that ensures the relationship between the three parameters of climate and weather. Therefore, the adequacy of the dynamics models is taken into account in the diagonal cells of the correlation matrix. In addition to time, different lists of objects are possible in factor analysis. The coefficient of correlation variation, that is, a measure of the functional relationship between the parameters of the system (annual weather at the weather station in Central England) is 0.8230 for trends, 0.8603 taking into account the annual dynamics of the four-membered model obtained from the computational capabilities of the software environment CurveExpert-1.40, and 0.9578 for the full up to the error of measurement wavelet analysis of the dynamics of the values of three factors. In all three methods of factor analysis, the meteorological parameter «average Annual temperature» was in the first place as the influencing variable, the «Maximum temperature» was in the second place, and the «Minimum temperature» was in the third place. As the dependent measure in these areas there are three kind of temperature. The comparison shows that among the binary relations between the three temperatures, the average temperature on the maximum air temperature in the surface layer of the atmosphere has the greatest influence on the correlation coefficient 0.9765. At the same time, all six equations refer to strong connections, so there is a high quantum certainty between the three types of temperature. But when predicting the most meaningful essence showed the maximum temperature.

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Experimental Study on Infrared Temperature Characteristics and Failure Modes of Marble with Prefabricated Holes under Uniaxial Compression

Energies ◽

10.3390/en14030713 ◽

2021 ◽

Vol 14 (3) ◽

pp. 713

Author(s):

Yanyan Peng ◽

Qunchao Lin ◽

Manchao He ◽

Chun Zhu ◽

Haijiang Zhang ◽

...

Keyword(s):

Uniaxial Compression ◽

Failure Modes ◽

Rock Sample ◽

Vertical Axis ◽

Maximum Temperature ◽

Thermal Imager ◽

Infrared Thermal Imaging ◽

Average Temperature ◽

Observation Area ◽

Evolution Behavior

In rock engineering, it is of great significance to study the failure mechanical behavior of rocks with holes. Using a combination of experiment and infrared detection, the strength, deformation, and infrared temperature evolution behavior of marble with elliptical holes under uniaxial compression were studied. The test results showed that as the vertical axis b of the ellipse increased, the peak intensity first decreased and then increased, and the minimum value appeared when the horizontal axis was equal to the vertical axis. The detection results of the infrared thermal imager showed that the maximum temperature, minimum temperature, and average temperature of the observation area in the loading stage showed a downward trend, and the range of change was between 0.02 °C and 1 °C. It was mainly due to the accumulation of energy in the loading process of the rock sample that caused the surface temperature of the specimen to decrease. In the brittle failure stage, macroscopic cracks appeared on the surface of the rock sample, which caused the energy accumulated inside to dissipate, thereby increasing the maximum temperature and average temperature of the rock sample. The average temperature increase was about 0.05 °C to about 0.19 °C. The evolution of infrared temperature was consistent with the mechanical characteristics of rock sample failure, indicating that infrared thermal imaging technology can provide effective monitoring for the study of rock mechanics. The research in this paper provides new ideas for further research on the basic characteristics of rock failure under uniaxial compression.

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Seed Set Patterns in East African Highland Cooking Bananas Are Dependent on Weather before, during and after Pollination

Horticulturae ◽

10.3390/horticulturae7070165 ◽

2021 ◽

Vol 7 (7) ◽

pp. 165

Author(s):

Allan Waniale ◽

Rony Swennen ◽

Settumba B. Mukasa ◽

Arthur K. Tugume ◽

Jerome Kubiriba ◽

...

Keyword(s):

Critical Period ◽

Floral Development ◽

Seed Set ◽

Correlation Coefficients ◽

Principal Component ◽

Maximum Temperature ◽

Fruit Pulp ◽

East African ◽

Average Temperature ◽

Wild Banana

Seed set in banana is influenced by weather, yet the key weather attributes and the critical period of influence are unknown. We therefore investigated the influence of weather during floral development for a better perspective of seed set increase. Three East African highland cooking bananas (EAHBs) were pollinated with pollen fertile wild banana ‘Calcutta 4′. At full maturity, bunches were harvested, ripened, and seeds extracted from fruit pulp. Pearson’s correlation analysis was then conducted between seed set per 100 fruits per bunch and weather attributes at 15-day intervals from 105 days before pollination (DBP) to 120 days after pollination (DAP). Seed set was positively correlated with average temperature (P < 0.05–P < 0.001, r = 0.196–0.487) and negatively correlated with relative humidity (RH) (P < 0.05–P < 0.001, r = −0.158–−0.438) between 75 DBP and the time of pollination. After pollination, average temperature was negatively correlated with seed set in ‘Mshale’ and ‘Nshonowa’ from 45 to 120 DAP (P < 0.05–P < 0.001, r = −0.213–−0.340). Correlation coefficients were highest at 15 DBP for ‘Mshale’ and ‘Nshonowa’, whereas for ‘Enzirabahima’, the highest were at the time of pollination. Maximum temperature as revealed by principal component analysis at the time of pollination should be the main focus for seed set increase.

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Establishing and Satisfying Thermal Requirements for Drilled Shaft Concrete Based on Durability Considerations

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198121996357 ◽

2021 ◽

pp. 036119812199635

Author(s):

Andrew Z. Boeckmann ◽

Zakaria El-tayash ◽

J. Erik Loehr

Keyword(s):

Mechanical Response ◽

Large Diameter ◽

Thermal Cracking ◽

Drilled Shafts ◽

Maximum Temperature ◽

Design Parameters ◽

Mass Concrete ◽

Temperature Differential ◽

Thermal Requirements ◽

Ettringite Formation

Some U.S. transportation agencies have recently applied mass concrete provisions to drilled shafts, imposing limits on maximum temperatures and maximum temperature differentials. On one hand, temperatures commonly observed in large-diameter drilled shafts have been observed to cause delayed ettringite formation (DEF) and thermal cracking in above-ground concrete elements. On the other, the reinforcement and confinement unique to drilled shafts should provide resistance to thermal cracking, and the provisions that have been applied are based on dated practices for above-ground concrete. This paper establishes a rational procedure for design of drilled shafts for durability requirements in response to hydration temperatures, which addresses both DEF and thermal cracking. DEF is addressed through maximum temperature differential limitations that are based on concrete mix design parameters. Thermal cracking is addressed through calculations that explicitly consider the thermo-mechanical response of concrete for predicted temperatures. Results from application of the procedure indicate consideration of DEF and thermal cracking potential for drilled shafts is prudent, but provisions that have been applied to date are overly restrictive in many circumstances, particularly the commonly adopted 35°F maximum temperature differential provision.

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The effect of average temperature on suicide rates in five urban California counties, 1999–⁠2019: an ecological time series analysis

BMC Public Health ◽

10.1186/s12889-021-11001-6 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Sierra Cheng ◽

Rebecca Plouffe ◽

Stephanie M. Nanos ◽

Mavra Qamar ◽

David N. Fisman ◽

...

Keyword(s):

Public Health ◽

Suicide Rate ◽

Minimum Temperature ◽

The United States ◽

Additive Models ◽

Maximum Temperature ◽

Mortality Data ◽

Average Temperature ◽

Suicide Rates ◽

Average Maximum

Abstract Background Suicide is among the top 10 leading causes of premature morality in the United States and its rates continue to increase. Thus, its prevention has become a salient public health responsibility. Risk factors of suicide transcend the individual and societal level as risk can increase based on climatic variables. The purpose of the present study is to evaluate the association between average temperature and suicide rates in the five most populous counties in California using mortality data from 1999 to 2019. Methods Monthly counts of death by suicide for the five counties of interest were obtained from CDC WONDER. Monthly average, maximum, and minimum temperature were obtained from nCLIMDIV for the same time period. We modelled the association of each temperature variable with suicide rate using negative binomial generalized additive models accounting for the county-specific annual trend and monthly seasonality. Results There were over 38,000 deaths by suicide in California’s five most populous counties between 1999 and 2019. An increase in average temperature of 1 °C corresponded to a 0.82% increase in suicide rate (IRR = 1.0082 per °C; 95% CI = 1.0025–1.0140). Estimated coefficients for maximum temperature (IRR = 1.0069 per °C; 95% CI = 1.0021–1.0117) and minimum temperature (IRR = 1.0088 per °C; 95% CI = 1.0023–1.0153) were similar. Conclusion This study adds to a growing body of evidence supporting a causal effect of elevated temperature on suicide. Further investigation into environmental causes of suicide, as well as the biological and societal contexts mediating these relationships, is critical for the development and implementation of new public health interventions to reduce the incidence of suicide, particularly in the face increasing temperatures due to climate change.

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