TOWARDS NANO-SCALE THERMOPHOTOVOLTAIC APPLICATIONS: DISCUSSIONS FOR MATERIAL SELECTION AND MEASURING SYSTEM

Author(s):  
Tuba Okutucu-Ozyurt ◽  
Elif Begum Elcioglu ◽  
Reha Denker ◽  
Azadeh Didari ◽  
M. Pinar Menguc
Author(s):  
Yan Xin Zhuang ◽  
Aric K. Menon

Fluorocarbon films, which can be used to minimize stiction of silicon microstructures, have been deposited by passivation process in deep reactive ion etching tool. The wettability, surface energy, nano-scale adhesive force, and thermal stability have been investigated by contact angle measuring system, atomic force microscopy (AFM) and ellipsometry. The fluorocarbon films are good for anti-stiction applications due to their high water contact angle (110°), low surface energy (14.5mJ/m2), low nano-scale adhesive force (33 nN) and high thermal stability up to 300°C.


Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3189 ◽  
Author(s):  
Shoukat Khan ◽  
Muataz Atieh ◽  
Muammer Koç

Nucleate boiling is a phase change heat transfer process with a wide range of applications i.e., steam power plants, thermal desalination, heat pipes, domestic heating and cooling, refrigeration and air-conditioning, electronic cooling, cooling of turbo-machinery, waste heat recovery and much more. Due to its quite broad range of applications, any improvement in this area leads to significant economic, environmental and energy efficiency outcomes. This paper presents a comprehensive review and critical analysis on the recent developments in the area of micro-nano scale coating technologies, materials, and their applications for modification of surface geometry and chemistry, which play an important role in the enhancement of nucleate boiling heat transfer. In many industrial applications boiling is a surface phenomenon, which depends upon its variables such as surface area, thermal conductivity, wettability, porosity, and roughness. Compared to subtractive methods, the surface coating is more versatile in material selection, simple, quick, robust in implementation and is quite functional to apply to already installed systems. The present status of these techniques for boiling heat transfer enhancement, along with their future challenges, enhancement potentials, limitations, and their possible industrial implementation are also discussed in this paper.


2013 ◽  
Vol 303-306 ◽  
pp. 435-439
Author(s):  
Jun Sheng Wu

Insulation measurement system performance influence of insulation material selection formula as well as the material production and quality. This paper introduces the insulation performance measuring system and control theory, and the ablation experiments of main technical parameters and data processing and insulation material performance evaluation standards: adiabatic index, the linear ablation rate, mass loss rate calculation and evaluation.


2020 ◽  
pp. 38-44
Author(s):  
A. V. Polyakov ◽  
M. A. Ksenofontov

Optical technologies for measuring electrical quantities attract great attention due to their unique properties and significant advantages over other technologies used in high-voltage electric power industry: the use of optical fibers ensures high stability of measuring equipment to electromagnetic interference and galvanic isolation of high-voltage sensors; external electromagnetic fields do not influence the data transmitted from optical sensors via fiber-optic communication lines; problems associated with ground loops are eliminated, there are no side electromagnetic radiation and crosstalk between the channels. The structure and operation principle of a quasi-distributed fiber-optic high-voltage monitoring system is presented. The sensitive element is a combination of a piezo-ceramic tube with an optical fiber wound around it. The device uses reverse transverse piezoelectric effect. The measurement principle is based on recording the change in the recirculation frequency under the applied voltage influence. When the measuring sections are arranged in ascending order of the measured effective voltages relative to the receiving-transmitting unit, a relative resolution of 0,3–0,45 % is achieved for the PZT-5H and 0,8–1,2 % for the PZT-4 in the voltage range 20–150 kV.


2020 ◽  
Vol 29 (8) ◽  
pp. 57-61
Author(s):  
V.Y. Chernykh ◽  
◽  
E.V. Karpushina ◽  
N. Yu. Bykova ◽  
A.S. Maksimov ◽  
...  
Keyword(s):  

2017 ◽  
Vol 2017 (45) ◽  
pp. 83-89
Author(s):  
A.A. Marusenkov ◽  

Using dedicated high-frequency measuring system the distribution of the Barkhausen jumps intensity along a reversal magnetization cycle was investigated for low noise fluxgate sensors of various core shapes. It is shown that Barkhausen (reversal magnetization) noise intensity is strongly inhomogeneous during an excitation cycle. In the traditional second harmonic fluxgate magnetometers the signals are extracted in the frequency domain, as a result, some average value of reversal magnetization noises is contributed to the output signals. In order to fit better the noise shape and minimize its transfer to the magnetometer output the new approach for demodulating signals of these sensors is proposed. The new demodulating method is based on information extraction in the time domain taking into account the statistical properties of cyclic reversal magnetization noises. This approach yields considerable reduction of the fluxgate magnetometer noise in comparison with demodulation of the signal filtered at the second harmonic of the excitation frequency.


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