scholarly journals Parametric Studies of a Mercury-Free DBD Lamp

Plasma ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 82-93
Author(s):  
Bruno Caillier ◽  
Laurent Therese ◽  
Philippe Belenguer ◽  
Philippe Guillot
Keyword(s):  
Indium Tin Oxide ◽  
High Efficiency ◽  
Barrier Discharge ◽  
Necessary Conditions ◽  
Electrical Signal ◽  
Major Interest ◽  
Xenon Mixture ◽  
Parametric Studies ◽  
Glass Plates ◽  
Alternative Solutions

Mercury discharge lamps are often used because of their high efficiency; however, the usage of mercury lamps will be restricted or forbidden for safety and environmental purposes. Finding alternative solutions to suppress mercury is of major interest. The aim of this work is to increase the luminous efficacy of a commercial-free mercury flat dielectric barrier discharge lamp (Planilum, St Gobain) in order to reach the necessary conditions for the lamp to be used as a daily lighting source. The lamp is made of two glass plates separated by a gap of 2 mm. The gap is filled by a neon xenon mixture. The external electrodes made of transparent ITO (indium tin oxide) are deposited on the lamp glass plates. The electrical signal applied to the electrodes generates a UV-emitting plasma inside the gap. Phosphors deposited on the glass allow the production of visible light. The original electrode geometry is plane-to-plane; this induces filamentary discharges. We show that changing the plane-to-plane geometry to a coplanar geometry allows the plasma to spread all over the electrode surface, and we can reach twice the efficacy of the lamp (32 lm/W) as compared to the original value. Using this new electrode geometrical configuration and changing the electrical signal from sinusoidal to a pulsed signal greatly improves the visual uniformity of the emitted light all over the lamp. Electrical and optical parametric measurements were performed to study the lamp characteristics. We show that it is possible to develop a free mercury lamp with an efficacy compatible with lighting purposes.

Comparison Between Two-Shaft Simple and Single-Shaft Recuperated Brayton Cycles Using Different Types of Gaseous Fuels

2010 ◽  
Author(s):  
A. K. Malkogianni ◽  
A. Tourlidakis ◽  
A. L. Polyzakis
Keyword(s):  
Natural Gas ◽  
Gas Turbines ◽  
Alternative Fuels ◽  
High Efficiency ◽  
Heating Value ◽  
Gaseous Fuels ◽  
Oil And Natural Gas ◽  
Parametric Studies ◽  
The Impact ◽  
Lower Heating

Geopolitical issues give rise to problems in the smooth and continuous flow of oil and natural gas from the production countries to the consumers’ development countries. In addition, severe environmental issues such as greenhouse gas emissions, eventually guide the consumers to fuels more suitable to the present situation. Alternative fuels such as biogas and coal gas have recently become more attractive because of their benefits, especially for electricity generation. On the other hand, the use of relatively low heating value fuels has a significant effect to the performance parameters of gas turbines. In this paper, the impact of using four fuels with different heating value in the gas turbine performance is simulated. Based on the high efficiency and commercialization criteria, two types of engines are chosen to be simulated: two-shaft simple and single-shaft recuperated cycle gas turbines. The heating values of the four gases investigated, correspond to natural gas and to a series of three gases with gradually lower heating values than that of natural gas. The main conclusions drawn from this design point (DP) and off-design (OD) analysis is that, for a given TET, efficiency increases for both engines when gases with low heating value are used. On the contrary, when power output is kept constant, the use of gases with low heating value will result in a decrease of thermal efficiency. A number of parametric studies are carried out and the effect of operating parameters on performance is assessed. The analysis is performed with customized software, which has been developed for this purpose.

Electron Multiplication and Electron Multipliers

2016 ◽  
pp. 9-48
Keyword(s):  
High Efficiency ◽  
Electrical Signal ◽  
Single Electron ◽  
Single Photons ◽  
Electron Avalanche ◽  
Avalanche Multiplication ◽  
Time Direction ◽  
Electron Multiplication ◽  
Position Sensitive

This chapter describes the process of electron avalanche multiplication, which is the only method known to detect the smallest possible electrical signal, a single electron at rest. Electron avalanche multiplication can advantageously be used in position sensitive photomultipliers to with high efficiency detect single photons with respect to position, time, direction and energy.

High‐efficiency indium tin oxide/indium phosphide solar cells

1989 ◽  
Vol 54 (26) ◽  
pp. 2674-2676 ◽  
Author(s):  
X. Li ◽  
M. W. Wanlass ◽  
T. A. Gessert ◽  
K. A. Emery ◽  
T. J. Coutts
Keyword(s):  
Solar Cells ◽  
Indium Phosphide ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
High Efficiency

scholarly journals Sterilizing Processes and Mechanisms for Treatment of Escherichia coli with Dielectric-Barrier Discharge Plasma

2019 ◽  
Vol 86 (1) ◽  
Author(s):  
Hao Wang ◽  
Liyang Zhang ◽  
Haiyun Luo ◽  
Xinxin Wang ◽  
Jinfeng Tie ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dielectric Barrier Discharge ◽  
High Efficiency ◽  
Barrier Discharge ◽  
Treatment Time ◽  
Survival Curve ◽  
Main Process ◽  
Dielectric Barrier ◽  
Plasma Sterilization ◽  
Preparation Period

ABSTRACT With increasing attention toward novel sterilization methods, plasma sterilization has gained more and more interest. However, the underlying mechanisms are still unknown. In this paper, we investigated the inactivation of Escherichia coli using dielectric-barrier discharge (DBD) plasma in saline water. There were three processes shown in the survival curve, namely, during the preparation period, the reaction period, and the saturation period. Observations under a transmission electron microscope (TEM) and detection by Fourier transform infrared spectroscopy (FT-IR) supplied adequate details regarding these processes. Based on these results, we infer that during the preparation period, the main process is the accumulation of chemical substances. During the reaction period, adequate amounts of chemicals decompose and denature cell membranes and macromolecules to kill bacteria in large quantities. During the saturation period, the killing effect decreases because of the protection by clustered cells and the saturation of pH. This study of sterilizing processes systematically reveals the mechanisms of plasma sterilization. IMPORTANCE Compared with traditional methods, plasma sterilization has advantages of high efficiency, easy operation, and environmental protection. This may be more suitable for air and sewage sterilization in specific spaces, such as hospitals, laboratories, and pharmaceutical factories. However, the mechanisms of sterilization are still relatively unknown, especially for bactericidal activities. Knowledge of sterilization processes provides guidance for practical applications. For example, the bactericidal action mainly occurs during the reaction period, and the treatment time can be set based on the reaction period, which could save a lot of energy. The results of this study will help to improve the efficiency of plasma sterilization devices.

Dielectric Barrier Discharge Structure Design for Sewage Treatment

2014 ◽  
Vol 1037 ◽  
pp. 57-60
Author(s):  
Jian Ping Jia ◽  
Li Cai ◽  
Shou Bo Zhang ◽  
Yuan Zhao
Keyword(s):  
Dielectric Barrier Discharge ◽  
High Efficiency ◽  
Barrier Discharge ◽  
Sewage Treatment ◽  
Structure Design ◽  
Treatment Technology ◽  
Temperature Plasma ◽  
Dielectric Barrier ◽  
Discharge Structure ◽  
Treatment Research

The problem of the urban water shortage and water pollution is becoming problem more and more serious. Therefore, governments around the world pay close attention to the application of sewage treatment technology, especially that with high efficiency, low energy consumption and strong operability. Dielectric barrier discharge (DBD) can produce low temperature plasma under atmospheric pressure, and the application of the technology for sewage treatment research gradually becomes to be one of hot research. In this paper, the dielectric barrier discharge structure is designed, and the plasma produced is used for sewage treatment research. The system adopts coaxial type discharge structure. The research shows that the structure is safe and reliable. And, it has low discharge power and can discharge uniformly. So, the plasma produced by dielectric barrier discharge can be convenient and easy to used in sewage treatment, and the result is effective.

The Effect of Different Plasma Treatments on the Pigment Dyeing of Cotton Fabrics

2012 ◽  
Vol 441 ◽  
pp. 96-101 ◽  
Author(s):  
Ying Chen ◽  
Zhi Jia Wang ◽  
Fu Jia Song ◽  
Yong Hua Xu
Keyword(s):  
Plasma Treatment ◽  
High Efficiency ◽  
Barrier Discharge ◽  
Particle Diameter ◽  
Cotton Fabrics ◽  
Atmospheric Plasma ◽  
Color Fastness ◽  
Dielectric Barrier ◽  
Plasma Treatments ◽  
Vacuum Atmosphere

In this paper, the application of glow discharge (low pressure) and dielectric barrier discharge (atmospheric) prior to pigment dyeing of cotton fabric was studied. Different parameters of power and time during the process were also discussed. The dyeing effect after different plasma treatment was analyzed by SEM observations and measurements of the K/S value, levelness and color fastness. The results indicated that the particle diameter of pigment affected pigment dyeing, and the K/S value increased as particle diameter decreased. These two plasma treatments could enhance the properties of pigment dyeing with satisfied color fastnesses. Fabrics treated by plasma should be dyed within 2 hours of plasma treatment to ensure optimum results. The power of atmospheric plasma treatments was relatively high without maintaining a vacuum atmosphere, and it could be processed continuously with high efficiency and K/S value.

Design Optimization of Turbo-Machinery Components With Independent FEA and CFD Tools in an Optimization Software Environment: A Mid-Span Shroud Ring Study Case

2011 ◽  
Author(s):  
Yuan-Ting Wu ◽  
Christian K. Funk ◽  
Pei-feng Hsu ◽  
Jerome Le Moine ◽  
Ran Zhou ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Drag Force ◽  
High Efficiency ◽  
Aerodynamic Drag ◽  
Low Cycle Fatigue ◽  
Turbine Blades ◽  
Integrated Design ◽  
Software Environment ◽  
Optimization Software ◽  
Parametric Studies

Shrouds are important for damping vibrations in gas turbine blades. In modern industrial high-output, high-efficiency engines, long turbine blades can require the use of a mid-span or partial-span damping ring. However, the inclusion of a mid-span damping shroud, or “snubber,” can have negative effects on the aerodynamic performance of the gas turbine stage and engine. Therefore, a method of iterative study and optimization was applied to minimize the drag force caused by the snubber, while maximizing the structural life of the blade. The approach used integrated design environment software to perform parametric studies of the design space in preparation for optimization of the blade snubber geometry. The drivers employed in Isight 4.0/4.5 [9] optimization software carried out the parametric study and reported the results to the designer. Considering these results, the designer chose the initial seeding geometry of the optimization driver which greatly reduced analysis time and the time required to reach the design objectives. This approach provides an integrated design workflow and facilitates parametric studies of advanced gas turbine blade component geometry, and the optimization of the component to meet targets of minimized aerodynamic drag force and maximized low-cycle fatigue life, goals crucial to the development of an advanced and efficient power generation gas turbine.

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