scholarly journals Chlorosulfonic Acid Stretched Carbon Nanotube Sheet for Flexible and Low-Voltage Heating Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2132
Author(s):  
Daniel Rui Chen ◽  
Megha Chitranshi ◽  
Paa Kwasi Adusei ◽  
Mark Schulz ◽  
Vesselin Shanov ◽  
...  

The carbon nanotube (CNT) is celebrated for its electrothermal property, which indicates the capability of a material to transform electrical energy into heat due to the Joule effect. The CNT nanostructure itself, as a one-dimensional material, limits the electron conduction path, thereby creating a unique heating phenomenon. In this work, we explore the possible correlation between CNT alignment in sheets and heating performance. The alignment of carbon nanotubes is induced by immersion and stretching in chlorosulfonic acid (CSA) solution. The developed CSA-stretched CNT sheet demonstrated excellent heating performance with a fast response rate of 6.5 °C/s and reached 180 °C in less than 30 s under a low voltage of 2.5 V. The heating profile of the stretched CNT sheet remained stable after bending and twisting movements, making it a suitable heating material for wearable devices, heatable smart windows, and in de-icing or defogging applications. The specific strength and specific conductance of the CSA-stretched CNT sheet also increased five- and two-fold, respectively, in comparison to the pristine CNT sheet.

Author(s):  
Benbouza Naima ◽  
Benfarhi Louiza ◽  
Azoui Boubekeur

Background: The improvement of the voltage in power lines and the respect of the low voltage distribution transformer substations constraints (Transformer utilization rate and Voltage drop) are possible by several means: reinforcement of conductor sections, installation of new MV / LV substations (Medium Voltage (MV), Low Voltage (LV)), etc. Methods: Connection of mini-photovoltaic systems (PV) to the network, or to consumers in underserved areas, is a well-adopted solution to solve the problem of voltage drop and lighten the substation transformer, and at the same time provide clean electrical energy. PV systems can therefore contribute to this solution since they produce energy at the deficit site. Results: This paper presents the improvement of transformer substation constraints, supplying an end of low voltage electrical line, by inserting photovoltaic systems at underserved subscribers. Conclusion: This study is applied to a typical load pattern, specified to the consumers region.


2007 ◽  
Vol 124-126 ◽  
pp. 1309-1312
Author(s):  
Nguyen Duc Hoa ◽  
Nguyen Van Quy ◽  
Gyu Seok Choi ◽  
You Suk Cho ◽  
Se Young Jeong ◽  
...  

A new type of gas sensor was realized by directly depositing carbon nanotube on nano channels of the anodic alumina oxide (AAO) fabricated on p-type silicon substrate. The carbon nanotubes were synthesized by thermal chemical vapor deposition at a very high temperature of 1200 oC to improve the crystallinity. The device fabrication process was also developed. The contact of carbon nanotubes and p-type Si substrate showed a Schottky behavior, and the Schottky barrier height increased with exposure to gases while the overall conductivity decreased. The sensors showed fast response and recovery to ammonia gas upon the filling (400 mTorr) and evacuation.


2016 ◽  
Vol 28 (44) ◽  
pp. 9752-9757 ◽  
Author(s):  
Albert Tianxiang Liu ◽  
Yuichiro Kunai ◽  
Pingwei Liu ◽  
Amir Kaplan ◽  
Anton L. Cottrill ◽  
...  

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2191
Author(s):  
Hongquan Zhang ◽  
Bin Shen ◽  
Wenbin Hu ◽  
Xinlei Liu

Nano Futures ◽  
2021 ◽  
Author(s):  
Luis Portilla ◽  
Jianwen Zhao ◽  
Jing Zhao ◽  
Luigi Occhipinti ◽  
Vincenzo Pecunia

Author(s):  
Feng Gao ◽  
Jianmin Qu ◽  
Matthew Yao

The carbon nanotube (CNT) is becoming a promising candidate as electrical interconnects in nanoscale electronics. This paper reports the electronic structure and the electrical conducting properties at the interface between an open-end single wall CNT (SWCNT) and various metal electrodes, such as Al, Au, Cu, and Pd. A simulation cell consisting of an SWCNT with each end connected to the metal electrode was constructed. A voltage bias is prescribed between the left- and right-electrodes to compute the electronic conductance. Due to the electronic structure, the electron density and local density of states (LDOS) are calculated to reveal the interaction behavior at the interfaces. The first-principle quantum mechanical density functional and non-equilibrium Green’s function (NEGF) approaches are adopted to compute the transport coefficient. After that, the voltage-current relation is calculated using the Landauer-Buttiker formalism. The results show that electrons are conducted through the electrode/CNT/electrode two-probe system. The contact electronic resistance is calculated by averaging the values in the low voltage bias regime (0.0–0.1 V), in which the voltage–current relationship is found to be linear. And the electrical contact conductance of electrode/CNT/electrode system show the electrode-type dependent, however, the amplitude for different electrodes is of the same order.


2007 ◽  
Vol 11 (3) ◽  
pp. 85-100
Author(s):  
Alija Lekic ◽  
Semsudin Hadziefendic

The main sources for power generation in Bosnia and Herzegovina are domestic coals, mainly lignite and brown coals, which are relatively characterized with a high content of sulphur (3-5%) and incombustibles (?30%). From the 70?s, use of this type of fuels was not allowed in the city of Sarajevo due to very unfavorable emissions to the atmosphere, during the heating period, and since then Sarajevo has been supplied with natural gas. All the heating installations in the city were reconstructed and adapted. The district heating system Toplane Sarajevo is supplied with electrical energy from the Public electrical distribution network (Elektrodistribucija Sarajevo) at low voltage (0.4 kV). The boiler-house Dobrinja III-2 (KDIII-2), from the district heating system of Sarajevo Suburb Dobrinja, which was not in use after the war 1992-1995, had a lot of advantages for the reconstruction into the co-generation plant. The Government of Canton Sarajevo financially supported this proposal. An analysis of co-generations for the district heating system and a selection of most appropriate co-generation systems were made. In the proposed conceptual design, the co-generation KDIII-2 was located in the existing boiler-house KDIII-2, connected with the heating system in Dobrinja. The operating costs of production of electricity and heat were evaluated in the study and compared with the costs of conventional energy supply to the district heating system. This analysis resulted in economic indicators, which showed that this investment was economically viable, and it also determined the payback period of the investment. In this paper results of the mentioned study and an overview of co-generation in Bosnia and Herzegovina are presented.


Author(s):  
Josifs Survilo ◽  
Antons Kutjuns

Operation Modes of HV/MV SubstationsA distribution network consists of high voltage grid, medium voltage grid, and low voltage grid. Medium voltage grid is connected to high voltage grid via substations with HV/MV transformers. The substation may contain one, mostly two but sometimes even more transformers. Out of reliability and expenditure considerations the two transformer option prevail over others mentioned. For two transformer substation, there may be made choice out of several operation modes: 1) two (small) transformers, with rated power each over 0.7 of maximum substation load, permanently in operation; 2) one (big) transformer, with rated power over maximum substation load, permanently in operation and small transformer in constant cold reserve; 3) big transformer in operation in cold season, small transformer-in warm one. Considering transformer load losses and no load losses and observing transformer loading factor β it can be said that the mode 1) is less advantageous. The least power losses has the mode 3). There may be singled out yet three extra modes of two transformer substations: 4) two big transformers in permanent operation; 5) one big transformer permanently in operation and one such transformer in cold reserve; 6) two small transformers in operation in cold season of the year, in warm season-one small transformer on duty. At present mostly two transformers of equal power each are installed on substations and in operation is one of them, hence extra mode 5). When one transformer becomes faulty, it can be changed for smaller one and the third operation mode can be practiced. Extra mode 4) is unpractical in all aspects. The mode 6) has greater losses than the mode 3) and is not considered in detail. To prove the advantage of the third mode in sense of power losses, the notion of effective utilization time of power losses was introduced and it was proven that relative value of this quantity diminishes with loading factor β. The use of advantageous substation option would make it possible to save notable amount of electrical energy but smaller transformer lifetime of this option must be taken into account as well.


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