scholarly journals Cooling rate, heating rate, and aging effects in glassy water

2004 ◽  
Vol 69 (5) ◽  
Author(s):  
Nicolas Giovambattista ◽  
H. Eugene Stanley ◽  
Francesco Sciortino
Keyword(s):  
Cooling Rate ◽  
Heating Rate ◽  
Aging Effects

Microclimate Variations with Wall Configurations for Chinese Solar Greenhouses

2013 ◽  
Vol 291-294 ◽  
pp. 931-937 ◽  
Author(s):  
Hui Xu ◽  
Lan Jie Zhao ◽  
Guo Hong Tong ◽  
Yi Qing Cui ◽  
Tian Lai Li
Keyword(s):  
Thermal Stability ◽  
Fly Ash ◽  
Cooling Rate ◽  
Heating Rate ◽  
Small Hole ◽  
Brick Wall ◽  
Optimal Temperature ◽  
Clay Brick ◽  
The North ◽  
Hollow Brick

Five greenhouses with different typical wall configurations were studied, including the hollow brick wall (HB), clay brick wall composed of mural column (MCCB), wall composed of fly ash air block brick (FAABB), clay brick wall composed of plum small hole column (PSHCCB), common clay brick wall with Styrofoam wall outside (SCB) to find out the effects of the north walls on the greenhouse microclimate. The interior temperature and RH environment, as well as the heating rate, cooling rate and the correlation with the outside temperature, were tested and compared, finding that the greenhouse with FAABB exhibits the optimal temperature and RH environment, and also the highest thermal stability. The findings may provide references for greenhouse construction and insulation measures.

scholarly journals Study on Mechanism of Glass Molding Process for Fingerprint Lock Glass Plates

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 394
Author(s):  
Wuyi Ming ◽  
Haojie Jia ◽  
Heyuan Huang ◽  
Guojun Zhang ◽  
Kun Liu ◽  
...  
Keyword(s):  
Residual Stress ◽  
Heat Conduction ◽  
Cooling Rate ◽  
Heating Rate ◽  
Relaxation Model ◽  
Glass Panel ◽  
Forming Process ◽  
Molding Process ◽  
Shape Deviation ◽  
Glass Forming

Curved glass is widely used in 3C industry, and the market demand is increasing gradually. Glass molding process (GMP) is a high-precision, high-efficiency 3D glass touch panel processing technology. In this study, the processing parameters of fingerprint lock glass panels were deeply analyzed. This paper first introduces the molding process of the glass panel, discusses the glass forming device, and explains the heat conduction principle of the glass. Firstly, it introduces the forming process of the glass panel, discusses the glass forming device, and explains the heat conduction principle of the glass. Secondly, the simulation model of a fingerprint lock glass plate was simulated by MSC. Marc software. The stress relaxation model and structure relaxation model are used in the model, and the heat transfer characteristics of glass mold are combined to accurately predict the forming process of glass components. The effects of molding temperature, heating rate, holding time, molding pressure, cooling rate and other process parameters on product quality characteristics (residual stress and shape deviation) were analyzed through simulation experiments. The results show that, in a certain range, the residual stress is inversely proportional to the bending temperature and heating rate, and is directly proportional to the cooling rate, while the shape deviation decreases with the increase of temperature and heating rate. When the cooling rate decreases, the shape deviation first decreases and then increases. Furthermore, a verification experiment is designed to verify the reliability of the simulation results by measuring and calculating the surface roughness of the formed products.

scholarly journals Thermal stress, cooling-rate and fictive temperature of silicate melts

2021 ◽  
Vol 176 (10) ◽  
Author(s):  
Sharon L. Webb
Keyword(s):  
Heat Capacity ◽  
Cooling Rate ◽  
Heating Rate ◽  
Calibration Curve ◽  
Silicate Melts ◽  
Internal Stresses ◽  
Heating Rates ◽  
Fictive Temperature ◽  
Slow Cooling ◽  
Cooling Rates

AbstractThe unknown cooling-rate history of natural silicate melts can be investigated using differential scanning heat capacity measurements together with the limiting fictive temperature analysis calculation. There are a range of processes occurring during cooling and re-heating of natural samples which influence the calculation of the limiting fictive temperature and, therefore, the calculated cooling-rate of the sample. These processes occur at the extremes of slow cooling and fast quenching. The annealing of a sample at a temperature below the glass transition temperature upon cooling results in the subsequent determination of cooling-rates which are up to orders of magnitude too low. In contrast, the internal stresses associated with the faster cooling of obsidian in air result in an added exothermic signal in the heat capacity trace which results in an overestimation of cooling-rate. To calculate cooling-rate of glass using the fictive temperature method, it is necessary to create a calibration curve determined using known cooling- and heating-rates. The calculated unknown cooling-rate of the sample is affected by the magnitude of mismatch between the original cooling-rate and the laboratory heating-rate when using the matched cooling-/heating-rate method to derive a fictive temperature/cooling-rate calibration curve. Cooling-rates slower than the laboratory heating-rate will be overestimated, while cooling-rates faster than the laboratory heating-rate are underestimated. Each of these sources of error in the calculation of cooling-rate of glass materials—annealing, stress release and matched cooling/heating-rate calibration—can affect the calculated cooling-rate by factor of 10 or more.

SOME FACTORS EFFECT ON ZERO-RESISTANCE TEMPERATURE OF SUPERCONDUCTR Y1Ba2Cu3O9−x

1987 ◽  
Vol 01 (02) ◽  
pp. 267-272 ◽  
Author(s):  
Liquan Chen ◽  
Zhili Xiao ◽  
Yuzhen Huang ◽  
Zhenhong Mai ◽  
Xi Chu ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Heating Rate ◽  
Oxygen Pressure ◽  
Sintering Temperature ◽  
Sintering Time ◽  
Zero Resistance ◽  
Temperature Heating

Some factors which might effect on Tco during the sintering procedure have been studied. These factors include the sintering time, sintering temperature, heating rate, cooling rate, oxygen pressure, annealing in different atmosphere and multiple sintering as well. The attention has also paid to the influence of Al3+ which might be introduced by using Al2O3 crucible.

Development of the Glassy State of Benzophenone and Effect of Heating Rate from the Glassy State on Solidification

1996 ◽  
Vol 455 ◽  
Author(s):  
Paul E. Thoma ◽  
John J. Boehm
Keyword(s):  
Phase Transformation ◽  
Solid State ◽  
Cooling Rate ◽  
Heating Rate ◽  
Melting Temperature ◽  
Glassy State ◽  
Equilibrium Structure ◽  
Solidification Temperature ◽  
Additional Heating ◽  
Solid State Phase Transformation

ABSTRACTBenzophenone supercools to a glass when cooled to −100°C. In fact, it is difficult to freeze benzophenone on cooling. In this investigation, the effect of cooling rate and the minimum cooling rate to obtain benzophenone as a glass is determined. From the glassy state, the influence of heating rate on the solidification temperature of benzophenone is determined. When heated at 3°C/min., solidification starts at about −29°C. Upon additional heating, melting usually starts at about +24°C, which is 23°C lower than the solid equilibrium structure melting temperature of 47°C. Occasionally the solid that forms at about −29°C undergoes a solid state phase transformation at about +22°C, when heated at 3°C/min. If this solid state phase transformation occurs, then the solid benzophenone starts to melt at 47°C. When solid benzophenone with the equilibrium structure is cooled to −100°C, no solid state phase transformation occurs. It appears that the structure that solidifies at −29°C is metastable.

Step-Sintering of Fe-(1-3)%Mn-0.8%C Steels

2020 ◽  
Vol 405 ◽  
pp. 373-378
Author(s):  
Monika Tenerowicz-Żaba ◽  
Maciej Sułowski
Keyword(s):  
Tensile Strength ◽  
Phase Transformation ◽  
Cooling Rate ◽  
Heating Rate ◽  
Microstructure Evolution ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Tensile Tests ◽  
Transformation Temperatures ◽  
Metallographic Observation

The aim of the study was to examine how the microstructure changes during heating of Fe-Mn-C system (step-sintering). Mixtures of powders containing 1 – 3 % Mn and 0.8 % C were prepared in Turbula TC2 mixer for 30 minutes. Before step-sintering, the dilatometric investigations were carried out, which allowed to obtain phase transformation temperatures of Fe-(1-3)Mn%-0.8%C system. Following dilatometric investigations, 4 steps – temperatures were determined dependently of isothermal sintering temperature. The commonly used industry temperatures – 1120 °C and 1250 °C – were set as target temperatures. For each of them, 4 heat steps were carried out. The procedure of investigations was as follows: samples were heated to the step temperature with heating rate 60 K/min, then isothermally sintered at step temperature for 5 min, and finally cooled to the room temperature with cooling rate ~ 66 K/min. Fe-Mn-C samples were mechanically (tensile) tested. After tensile tests, metallographic observations of the samples were performed. Based on the results obtained, the tensile strength was increasing with the increasing of the step temperature. The metallographic observation showed the microstructure evolution – with increasing the step temperature, decreasing of porosity was observed.

The Residual Stress after High Frequency Induction Welding with Complex Shapes WC-Co Alloy and Steel

2014 ◽  
Vol 852 ◽  
pp. 168-172 ◽  
Author(s):  
Jia Ju ◽  
Feng Xue ◽  
Jian Zhou ◽  
Jing Bai
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Cooling Rate ◽  
Heating Rate ◽  
High Strength ◽  
High Heating Rate ◽  
Element Simulation ◽  
Complex Shapes ◽  
High Frequency Induction

Residual stresses were investigation by Three-D finite element simulation and experimental method. The Three-D finite element simulation confirms large residual stress appears in seam zone because of the crack part and the maximum loading parts were not coinciding. The heating/cooling rate can seriously affect the residual stress. Along with the heating rate decrease, the residual stress reduces in material and had big drop in high heating rate range than lower range. And cooling rate influence the residual stress in cemented carbide was more sensitive than in steel. Meanwhile, far away the seam, the residual stress decrease and became stable. After heat treatment, the residual stress reduced from more than 800MPa, 300MPa to less 100MPa, 52Mpa in WC-Co side and steel side respectively and the material had better abrasion resistance and high strength.

Preliminary Study of Refined Naphthalene Production with Fractional Crystallization

2012 ◽  
Vol 554-556 ◽  
pp. 51-55
Author(s):  
Gui Ying Xu ◽  
Zhan Xian Gao ◽  
Jian Zhang ◽  
Jin Feng Bai
Keyword(s):  
Cooling Rate ◽  
Heating Rate ◽  
Fractional Crystallization ◽  
Theoretical Foundation ◽  
Holding Time ◽  
Starting Material ◽  
Operating Condition ◽  
Technology Improvement ◽  
Preliminary Study ◽  
Yield And Purity

In order to obtain optimized operating condition for industry naphthalene purification using fractional crystallizing method, the influence of heating rate, crystallizing times, holding time and cooling rate on the yield and purity of industrial naphthalene were studied. The industrial naphthalene from AISC Chemical General tar workshop was used as starting material in the study. The results show that the yield and purity of refined naphthalene can achieve 94.2％ and 99.30％ respectively, when the heating rate is 1.2°C/h, the cooling rate is 3°C/h, holding time is 5 hours and the crystallizing times is 3. The result of present study provides a theoretical foundation for the actual production and technology improvement of naphthalene purification.

Thermal adjustments to nonexertional heat stress in mature and senescent Fischer 344 rats

1990 ◽  
Vol 68 (4) ◽  
pp. 1337-1342 ◽  
Author(s):  
K. C. Kregel ◽  
C. M. Tipton ◽  
D. R. Seals
Keyword(s):  
Heat Stress ◽  
Cooling Rate ◽  
Heating Rate ◽  
Control Level ◽  
Fischer 344 Rats ◽  
Level Control ◽  
Fischer 344 ◽  
Initial Control ◽  
Rate Of Heating ◽  
Colonic Temperature

The purpose of this study was to test the hypothesis that the rise in colonic temperature (Tc) during nonexertional heat stress is exaggerated in senescent (SEN, 24 mo, n = 12) vs. mature (MAT, 12 mo, n = 15) conscious unrestrained Fischer 344 rats. On 2 separate days (48 h apart) each SEN and MAT animal was exposed to an ambient temperature (Ta) of 42 degrees C (relative humidity 20%) until a Tc of 41 degrees C was attained and then cooled at a Ta of 26 degrees C until Tc returned to the initial control level. Control Tc was similar in the two groups for both trials. The rate of Tc change during heating was 63% greater (0.070 +/- 0.005 vs. 0.043 +/- 0.004 degrees C/min, P less than 0.05) and the time to 41 degrees C reduced by 36% (54 +/- 6 vs. 85 +/- 10 min, P less than 0.05) in MAT vs. SEN animals during the first exposure, although the cooling rate was slower in the MAT (0.048 +/- 0.004 degrees C/min) vs. SEN (0.062 +/- 0.006 degrees C/min) animals (P less than 0.05). The heating rate was unchanged in MAT animals between trials 1 and 2. However, SEN animals had a 95% increase in heating rate in trial 2 compared with trial 1 (P less than 0.05), and the corresponding time to 41 degrees C was decreased by 44% (P less than 0.05). As a result, rate of heating and time to 41 degrees C were similar in the two groups during trial 2. The cooling rate was similar between trials within each group.(ABSTRACT TRUNCATED AT 250 WORDS)

Sign in / Sign up

Export Citation Format

Share Document