A novel approach on accelerated ageing towards reliability optimization of high concentration photovoltaic cells

2014 ◽  
Author(s):  
John A. Tsanakas ◽  
Damien Jaffre ◽  
Mathieu Sicre ◽  
Rachid Elouamari ◽  
Alexis Vossier ◽  
...  
Keyword(s):  
Photovoltaic Cells ◽  
Accelerated Ageing ◽  
Reliability Optimization ◽  
High Concentration ◽  
Novel Approach

A Novel Approach of Fabricating Monodispersed Spherical MoSiBTiC Particles for Additive Manufacturing

2021 ◽  
Author(s):  
Zhenxing Zhou ◽  
Suxia Guo ◽  
Weiwei Zhou ◽  
Naoyoki Nomura
Keyword(s):  
Additive Manufacturing ◽  
Melting Process ◽  
Industrial Applications ◽  
Elemental Distribution ◽  
Drying Process ◽  
High Concentration ◽  
Novel Approach ◽  
Composition Ratios ◽  
Mesh Structures ◽  
Ejection Method

Abstract It is very challenging to fabricate spherical refractory material powders for additive manufacturing (AM) because of their high melting points and complex compositions. In this study, a novel technique, freeze-dry pulsated orifice ejection method (FD-POEM), was developed to fabricate spherical MoSiBTiC particles without a melting process. Elemental nanopowders were dispersed in water to prepare a high-concentration slurry, which was subsequently extruded from an orifice by diaphragm vibration and frozen instantly in liquid nitrogen. After a freeze-drying process, spherical composite particles with arbitrary composition ratios were obtained. The FD-POEM particles had a narrow size range and uniform elemental distribution. Mesh structures were formed within the FD-POEM particles, which was attributed to the sublimation of ice crystals. Furthermore, owing to their spherical morphology, the FD-POEM particles had a low avalanche angle of 42.6°, exhibiting good flowability. Consequently, the combination of FD-POEM and additive manufacturing has great potential for developing complex refractory components used in industrial applications.

scholarly journals GABAA Receptor/STEP61 Signaling Pathway May Be Involved in Emulsified Isoflurane Anesthesia in Rats

2020 ◽  
Vol 21 (11) ◽  
pp. 4078 ◽  
Author(s):  
Xingkai Zhao ◽  
Guangjun Chang ◽  
Yan Cheng ◽  
Zhenlei Zhou
Keyword(s):  
Gamma Aminobutyric Acid ◽  
High Concentration ◽  
Messenger Ribonucleic Acid ◽  
Novel Approach ◽  
Nociceptive Stimulus ◽  
Mrna And Protein Expression ◽  
Ion Channel Proteins ◽  
Polymerase Chain ◽  
The Brain ◽  
Α1 Subunit

(1) Background: Emulsified isoflurane (EISO) is a type of intravenous anesthetic. How emulsified isoflurane works in the brain is still unclear. The aim of this study was to explore whether epigenetic mechanisms affect anesthesia and to evaluate the anesthetic effects of emulsified isoflurane in rats. (2) Methods: Rats were randomly divided into four groups (n = 8/group): The tail vein was injected with normal saline 0.1 mL·kg−1·min−1 for the control (Con) group, with intralipid for the fat emulsion (FE) group, with EISO at 60 mg·kg−1·min−1 for the high-concentration (HD) group, and 45 mg·kg−1·min−1 for the low-concentration (LD) group. The consciousness state, motor function of limbs, and response to nociceptive stimulus were observed after drug administration. (3) Results: Using real-time polymerase chain reaction (PCR) to assess the promoter methylation of ion channel proteins in the cerebral cortex of rats anesthetized by EISO, we demonstrated that the change in the promoters’ methylation of the coding genes for gamma-aminobutyric acid A receptor α1 subunit (GABAAα1), N-methyl-D-aspartate receptor subunit 1 (NMDAR1), and mu opioid receptor 1 (OPRM1) was accompanied by the change in messenger ribonucleic acid (mRNA) and protein expression by these genes. (4) Conclusion: These data suggest that the epigenetic factors’ modulation might offer a novel approach to explore the anesthetic mechanism of EISO.

scholarly journals Performance of Multi Junction Photovoltaic Cells with High Concentration Ratio

2014 ◽  
Vol 61 ◽  
pp. 2258-2261 ◽  
Author(s):  
A. Aldossary ◽  
A. Algarue ◽  
S. Mahmoud ◽  
R.K. AL-Dadah
Keyword(s):  
Concentration Ratio ◽  
Photovoltaic Cells ◽  
High Concentration

Computational Analysis of Nanofluid Cooling of High Concentration Photovoltaic Cells

2014 ◽  
Vol 6 (3) ◽  
Author(s):  
Z. Xu ◽  
C. Kleinstreuer
Keyword(s):  
Reynolds Number ◽  
Energy Use ◽  
Volume Fraction ◽  
Cooling System ◽  
Optimal Parameter ◽  
Photovoltaic Cells ◽  
System Efficiency ◽  
Operational Parameters ◽  
High Concentration ◽  
Temperature Range

High concentration photovoltaic devices require effective heat rejection to keep the solar cells within a suitable temperature range and to achieve acceptable system efficiencies. Various techniques have been developed to achieve these goals. For example, nanofluids as coolants have remarkable heat transfer characteristics with broad applications; but, little is known of its performance for concentration photovoltaic cooling. Generally, a cooling system should be designed to keep the system within a tolerable temperature range, to minimize energy waste, and to maximize system efficiency. In this paper, the thermal performance of an Al2O3-water cooling system for densely packed photovoltaic cells under high concentration has been computationally investigated. The model features a representative 2D cooling channel with photovoltaic cells, subject to heat conduction and turbulent nanofluid convection. Considering a semi-empirical nanofluid model for the thermal conductivity, the influence of different system design and operational parameters, including required pumping power, on cooling performance and improved system efficiency has been evaluated. Specifically, the varied system parameters include the nanoparticle volume fraction, the inlet Reynolds number, the inlet nanofluid temperature, and different channel heights. Optimal parameter values were found based on minimizing the system's entropy generation. Considering a typical 200-sun concentration, the best performance can be achieved with a channel of 10 mm height and an inlet Reynolds number of around 30,000, yielding a modest system efficiency of 20%. However, higher nanoparticle volume fractions and lower nanofluid inlet temperatures further improve the cell efficiency. For a more complete solar energy use, a combined concentration photovoltaic and thermal heating system are suggested.

scholarly journals Using a Novel Approach to Estimate Packing Density and Related Electrical Resistance in Multiwall Carbon Nanotube Networks

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2350
Author(s):  
Usha Philipose ◽  
Yan Jiang ◽  
Gavin Farmer ◽  
Chris Howard ◽  
Michael Harcrow ◽  
...  
Keyword(s):  
Complex Network ◽  
Electrical Resistance ◽  
Mass Density ◽  
Areal Density ◽  
Multiwall Carbon Nanotube ◽  
High Concentration ◽  
Multi Wall Carbon Nanotubes ◽  
Novel Approach ◽  
Dimensional Network ◽  
Percolation Behavior

In this work, we use contrast image processing to estimate the concentration of multi-wall carbon nanotubes (MWCNT) in a given network. The fractal dimension factor (D) of the CNT network that provides an estimate of its geometrical complexity, is determined and correlated to network resistance. Six fabricated devices with different CNT concentrations exhibit D factors ranging from 1.82 to 1.98. The lower D-factor was associated with the highly complex network with a large number of CNTs in it. The less complex network, having the lower density of CNTs had the highest D factor of approximately 2, which is the characteristic value for a two-dimensional network. The electrical resistance of the thin MWCNT network was found to scale with the areal mass density of MWCNTs by a power law, with a percolation exponent of 1.42 and a percolation threshold of 0.12 μg/cm2. The sheet resistance of the films with a high concentration of MWCNTs was about six orders of magnitude lower than that of less dense networks; an effect attributed to an increase in the number of CNT–CNT contacts, enabling more efficient electron transfer. The dependence of the resistance on the areal density of CNTs in the network and on CNT network complexity was analyzed to validate a two-dimension percolation behavior.

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