scholarly journals Model Experimental Study of Carbon Fiber Heating Wire for Deicing and Snow Melting on a Bridge Deck

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yan Tan ◽  
Yuntao Zhu ◽  
Henglin Xiao
Keyword(s):  
Surface Layer ◽  
Carbon Fiber ◽  
Temperature Change ◽  
Temperature Rise ◽  
Bridge Deck ◽  
Ice Melting ◽  
Snow Melting ◽  
Change Rate ◽  
Temperature Change Rate ◽  
Heating Wire

In order to use the carbon fiber heating wire more efficiently and safely, the influence of the built-in carbon fiber heating wires (CFHWs) on the temperature changes of the bridge deck is studied in this paper. The model experiments of the temperature rise and ice melting are carried out in a room with low temperature cold storage environment, and the temperature variation of the specimens under different ambient temperatures, namely, −2, −4, and −8°C, was measured. The results show that, in the temperature rise experiment, the temperature change rate of the measuring points of the surface layer in the central part above CFHW is the most obvious, with the temperature change rate of 2.123°C/h; owing to the limited radiation range of CFHW, the temperature change rate of the measuring points between the CFHW and the CFHW of the surface layer decreases significantly, with a value of 0.703°C/h, and the temperature of the measuring points of the heating layer where CFHW is located shows a nearly linear increase, with a temperature change rate of 1.313°C/h. The temperature of the bridge deck is basically above 0°C as most of the heat generated by CFHW is transferred to the bridge deck after heating, which can effectively prevent the bridge deck from freezing. In the ice melting experiment, the temperature change rate of the measuring points of the surface layer in the central part above the CFHW is 1.406°C/h, and the maximum temperature change rate of the measuring points between the CFHW and CFHW of the surface layer is 0.408°C/h. The overall ice melting condition on the specimen surface is appreciable. When the heating power is set to 190 W/m2, the influence of the ambient temperature on the measuring points of the surface layer is negligible, but the influence of the ice melting rate at different positions from the heating wire is obvious. Therefore, it can be seen that optimizing the layout of the CFHW can effectively improve the whole uniformity and efficiency of ice melting of the bridge deck. The results from relevant research can provide a reference for the design and operation of deicing and snow melting applications on a bridge deck.

Automated serial dilutions for high-dynamic-range assays enabled by fill-level-coupled valving in centrifugal microfluidics

Lab on a Chip ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 2205-2219 ◽  
Author(s):  
Peter Juelg ◽  
Mara Specht ◽  
Elena Kipf ◽  
Michael Lehnert ◽  
Cornelia Eckert ◽  
...  
Keyword(s):  
Temperature Change ◽  
Dynamic Range ◽  
High Dynamic Range ◽  
Centrifugal Microfluidics ◽  
Microfluidic Platforms ◽  
Change Rate ◽  
Temperature Change Rate ◽  
High Dynamic ◽  
Fill Level ◽  
Serial Dilutions

Time-independent, serial valving under rotation on centrifugal microfluidic platforms by a fill-level-coupled temperature change rate (FLC-TCR) actuated principle.

Analyzing Hysteresis and Thermal Expansion Coefficient of M40/AZ91D during Thermal Cycling

2017 ◽  
Vol 898 ◽  
pp. 890-897
Author(s):  
Mei Hui Song ◽  
Yu Zhang ◽  
Yan Chun Li ◽  
Guo Qin Chen ◽  
Zi Yang Xiu
Keyword(s):  
Thermal Expansion ◽  
Thermal Cycling ◽  
Temperature Change ◽  
Residual Strain ◽  
Coefficient Of Thermal Expansion ◽  
Internal Heat ◽  
Impregnation Method ◽  
Change Rate ◽  
Temperature Range ◽  
Temperature Change Rate

In this work, AZ91D composite reinforced with M40 fiber was prepared by pressure impregnation method. Expansion behaviors of M40/AZ91D composite were studied with thermal expansion instrument in 25-150 °C and 25-150 °C temperature ranges of internal heat circulation, and then analyzed the influence law of hysteresis, residual strain and coefficient of thermal expansion (CTE) by different temperature change rate. The results revealed that residual stress and strain in process of pressure impregnation would lead to strain hysteresis and residual strain of composite in thermal cycling. At the same time, the CTE of the composites decreased with the increase of cycle times. Residual strain of the composite went up with the rise of temperature changed rate of the thermal cycling and CTE decreased with temperature change rate ascending in the 25-150°C temperature range. The CTE of the composites decreased with the increase of temperature during the heating process, which cut down with the increase of temperature in process of heating and cooling in the 25-495°C temperature range.

Transient Thermal Stress and Temperature Change Rate Analysis of Fixed Tubesheet

2018 ◽  
Author(s):  
Zhijian Wang ◽  
Qianyu Shi ◽  
Qi Li ◽  
Liping Wan ◽  
Hui Tang
Keyword(s):  
Thermal Stress ◽  
Stress Analysis ◽  
Temperature Change ◽  
Heat Exchangers ◽  
Change Rate ◽  
Rate Analysis ◽  
Temperature Change Rate ◽  
The Difference ◽  
Transient Thermal ◽  
Ansys Workbench

Some fixed tubesheet heat exchangers suffer amount of system startup and shutdown causing large thermal stress for tubesheets. It will make an impact on the fatigue damage of the equipment. Transient thermal and stress analysis were carried out in many papers, but the geometry models were simplified, the non-expanded part of the tube and tubesheet were not modeled in detail at the end of tube. In fact, there is a tiny gap enclosed by tube, tubesheet and weld. So in this paper, a simplified model and an accurate model are established, the transient thermal and stress analysis were performed in ANSYS Workbench. The difference between two models was compared and the influence of temperature change rate on thermal stress was discussed.

scholarly journals Neural correlates of fear-induced sympathetic response associated with the peripheral temperature change rate

NeuroImage ◽  
2016 ◽  
Vol 134 ◽  
pp. 522-531 ◽  
Author(s):  
Kazufumi Yoshihara ◽  
Hiroki C. Tanabe ◽  
Hiroaki Kawamichi ◽  
Takahiko Koike ◽  
Mika Yamazaki ◽  
...  
Keyword(s):  
Temperature Change ◽  
Neural Correlates ◽  
Change Rate ◽  
Sympathetic Response ◽  
Temperature Change Rate ◽  
Peripheral Temperature

Temperature change rate actuated bubble mixing for homogeneous rehydration of dry pre-stored reagents in centrifugal microfluidics

Lab on a Chip ◽  
2018 ◽  
Vol 18 (2) ◽  
pp. 362-370 ◽  
Author(s):  
S. Hin ◽  
N. Paust ◽  
M. Keller ◽  
M. Rombach ◽  
O. Strohmeier ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Temperature Change ◽  
Nucleic Acid Amplification ◽  
Centrifugal Microfluidics ◽  
Change Rate ◽  
Temperature Change Rate

Temperature change rate as actuation principle for a bubble mixer in centrifugal microfluidics minimizes external means required. We applied the new bubble mixer to the rehydration of dry reagents for nucleic acid amplification.

Robust temperature change rate actuated valving and switching for highly integrated centrifugal microfluidics

Lab on a Chip ◽  
2017 ◽  
Vol 17 (5) ◽  
pp. 864-875 ◽  
Author(s):  
M. Keller ◽  
G. Czilwik ◽  
J. Schott ◽  
I. Schwarz ◽  
K. Dormanns ◽  
...  
Keyword(s):  
Temperature Change ◽  
Rotational Frequency ◽  
Additional Cost ◽  
Centrifugal Microfluidics ◽  
Change Rate ◽  
Thermally Induced ◽  
Temperature Change Rate

Thermally induced underpressure for temperature change rate (TCR) actuated siphon valving, which is controlled by the rotational frequency. The TCR actuated siphon valve makes use of already present air vents for implementation at no additional cost in centrifugal microfluidics.

Characterizations of (Mn, Sb) Co-Tuned PZMNS-PZT Piezoelectric Ceramics in the Morphotropic Phase Boundary and their Applications on Multi-Bulk Step-Down Piezoelectric Transformers

2015 ◽  
Vol 655 ◽  
pp. 147-152
Author(s):  
Cheng Che Tsai ◽  
Hsiang Ho Hsieh ◽  
Sheng Yuan Chu ◽  
Zong You Chen ◽  
S.K. Huang
Keyword(s):  
Phase Boundary ◽  
Temperature Change ◽  
Morphotropic Phase Boundary ◽  
Temperature Stability ◽  
Rhombohedral Phase ◽  
Maximum Efficiency ◽  
Change Rate ◽  
Temperature Change Rate ◽  
Step Down ◽  
Piezoelectric Transformers

In this study, the (Mn, Sb) co-tuned PbCa0.01[(MnxZn0.1-x)1/3(SbxNb0.1-x)2/3 (Zr0.505Ti0.4895)0.9]O3 (PCZMNSZT-100x) ceramics were prepared near the morphotropic phase boundary (MPB) using the wolframite precursor method. The phase structure evolutions, electrical and temperature stability properties were systematically investigated. As the fraction of rhombohedral phase increases, the degree of disorder in the diffused phase transition (DPT) correspondingly increased and the “hard” piezoelectric characterization would be enhanced. Moreover, the temperature change rate of k, Qm and fr can be tuned by adjusting the x content. The specimens with x=0.08 exhibit the obtained values as kp ~ 0.50, kt ~ 0.52, Qm ~ 1550, and the low temperature change rate of properties having Δfr/fr = -0.02% and ΔQm/Qm = 10.5%, up to 100 °C. To evaluate the material feasibility, the proposed multi-bulk step-down transformers using a ring/dot structure are fabricated. Their obtained electrical properties have a maximum efficiency of 92% with an output power of 15 W, a voltage gain of 0.68 and a nearly zero temperature change rate of resonant frequency are found at the load of 100 Ω.

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