PARAMETRIC MODEL OF RESISTANCE OF PLASMA-EROSIVE LOAD, ADEQUATE IN THE WIDE RANGE OF CHANGE OF APPLIED VOLTAGE

2017 ◽  
Vol 2017 (3) ◽  
pp. 3-12 ◽  
Author(s):  
N.A. Shydlovska ◽  
◽  
S.M. Zakharchenko ◽  
O.P. Cherkaskyi ◽  
◽  
...  
Keyword(s):  
Applied Voltage ◽  
Parametric Model ◽  
Wide Range

The Influence of Barrier and Applied Voltage Parameters on the Impulse Surface Discharge Characteristics

2020 ◽  
Vol 11 (11) ◽  
pp. 17-27
Author(s):  
Vadim V. VOEVODIN ◽  
◽  
Marina V. SOKOLOVA ◽  
Viktor R. SOLOV’YEV ◽  
Nikolay Yu. LYSOV ◽  
...  
Keyword(s):  
Applied Voltage ◽  
Voltage Pulse ◽  
Discharge Zone ◽  
Surface Discharge ◽  
Initial Surface ◽  
Barrier Material ◽  
Dielectric Barrier ◽  
Discharge Ignition ◽  
Study Results ◽  
Wide Range

The results from an experimental study of impulse surface discharge occurring in an electrode system containing a dielectric plate are presented. On one of its sides, the plate had a corona-producing electrode made of 50 mm thick copper foil grounded through a current shunt for measuring the discharge current. On its other side, the plate had a high-voltage electrode, to which the voltage from a pulse generator was applied. The article presents the results from measurements of the initial voltage and the sizes of the surface discharge area in air when applying single voltage pulses with different pulse front steepness in the range 0,1–3,4 kV/ms and amplitude in the range 7–15 kV. The measurements were carried out for different dielectric barrier materials with the e values from 2 to 35. The dielectric barrier thickness was 0,9–1,8 mm. The study results have shown that the initial surface discharge ignition voltage depends essentially on the voltage pulse parameters, whereas the barrier characteristics have a weaker effect on this voltage. It has been determined that the discharge has different discharge zone length and different structure depending on the dielectric barrier properties and applied voltage parameters. The streamer zone sizes decrease with increasing the barrier material e value at the same voltage pulse steepness and increase with increasing the steepness for each barrier material. The data obtained for a wide range of external conditions can be used in numerical modeling of discharge.

scholarly journals Effect of Magnetic Field and Aggregation on Electrical Characteristics of Magnetically Responsive Suspensions for Novel Hybrid Liquid Capacitor

2019 ◽  
Vol 5 (2) ◽  
pp. 38 ◽  
Author(s):  
Kunio Shimada
Keyword(s):  
Magnetic Field ◽  
Electrical Properties ◽  
Natural Rubber ◽  
Applied Voltage ◽  
Nonlinear Response ◽  
Magnetic Particles ◽  
Particle Aggregation ◽  
Electrical Characteristics ◽  
Rubber Latex ◽  
Wide Range

Magnetically responsive fluid based on polymers of natural rubber (NR-latex) involves a magnetic compound fluid (MCF) rubber liquid. For a wide range of engineering applications of suspensions or liquids with particles, their electrical characteristics of fluidic suspensions are investigated to obtain useful results that might be important in the study of devices, such as fluidic sensors and capacitors. The author of the present paper proposes that MCF rubber liquid can be produced by combining MCF and rubber latex. The influence of the aggregation of magnetic particles and rubber molecules on electrical characteristics under a magnetic field was investigated by measuring electrical properties under an applied voltage. The electrical characteristics change with a linear or a nonlinear response, based on conditions of particle aggregation. The capacity of the electric charge also changes with the conditions of particle aggregation. These results show that MCF rubber liquid is a novel hybrid capacitor.

scholarly journals The Development of an Ordinary Least Squares Parametric Model to Estimate the Cost Per Flying Hour of ‘Unknown’ Aircraft Types and a Comparative Application †

Aerospace ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 104 ◽  
Author(s):  
Ilias Lappas ◽  
Michail Bozoudis
Keyword(s):  
Least Squares ◽  
Large Scale ◽  
Ordinary Least Squares ◽  
Parametric Model ◽  
Development Programs ◽  
Cost Estimating ◽  
Life Cycle Stages ◽  
Wide Range ◽  
High Level ◽  
The Cost

The development of a parametric model for the variable portion of the Cost Per Flying Hour (CPFH) of an ‘unknown’ aircraft platform and its application to diverse types of fixed and rotary wing aircraft development programs (F-35A, Su-57, Dassault Rafale, T-X candidates, AW189, Airbus RACER among others) is presented. The novelty of this paper lies in the utilization of a diverse sample of aircraft types, aiming to obtain a ‘universal’ Cost Estimating Relationship (CER) applicable to a wide range of platforms. Moreover, the model does not produce absolute cost figures but rather analogy ratios versus the F-16’s CPFH, broadening the model’s applicability. The model will enable an analyst to carry out timely and reliable Operational and Support (O&S) cost estimates for a wide range of ‘unknown’ aircraft platforms at their early stages of conceptual design, despite the lack of actual data from the utilization and support life cycle stages. The statistical analysis is based on Ordinary Least Squares (OLS) regression, conducted with R software (v5.3.1, released on 2 July 2018). The model’s output is validated against officially published CPFH data of several existing ‘mature’ aircraft platforms, including one of the most prolific fighter jet types all over the world, the F-16C/D, which is also used as a reference to compare CPFH estimates of various next generation aircraft platforms. Actual CPFH data of the Hellenic Air Force (HAF) have been used to develop the parametric model, the application of which is expected to significantly inform high level decision making regarding aircraft procurement, budgeting and future force structure planning, including decisions related to large scale aircraft modifications and upgrades.

scholarly journals Resonant tunneling characteristics in SiO2/Si double-barrier structures in a wide range of applied voltage

2003 ◽  
Vol 83 (7) ◽  
pp. 1456-1458 ◽  
Author(s):  
Hiroya Ikeda ◽  
Masanori Iwasaki ◽  
Yasuhiko Ishikawa ◽  
Michiharu Tabe
Keyword(s):  
Applied Voltage ◽  
Resonant Tunneling ◽  
Double Barrier ◽  
Wide Range

scholarly journals Application of the Exponentiated Log-Logistic Weibull Distribution to Censored Data

2019 ◽  
pp. 12-19
Author(s):  
Adeniyi F. Fagbamigbe ◽  
Gomolemo K. Basele ◽  
Boikanyo Makubate ◽  
Broderick O. Oluyede
Keyword(s):  
Survival Analysis ◽  
Censored Data ◽  
Life Time ◽  
Parametric Model ◽  
Exponential Distributions ◽  
Wide Range ◽  
Competitive Model ◽  
Income Data ◽  
Censored Observations ◽  
Better Than

In a recent paper, a new model called the Exponentiated Log-Logistic Weibull (ELLoGW) distribution with applications to reliability, survival analysis and income data was proposed. In this study, we applied the recently developed ELLoGW model to a wide range of censored data. We found that the ELLoGW distribution is a very competitive model for describing censored observations in life-time reliability problems such as survival analysis. This work shows that in certain cases, the ELLoGW distribution performs better than other parametric model such as the Log-Logistic Weibull, Exponentiated Log-Logistic Exponential, Log-Logistic Exponential distributions and the non-nested Gamma-Dagum (GD).

scholarly journals Electrocoagulation Treatment for Landfill Leachate using Stainless Steel Electrode

2019 ◽  
Vol 9 (1) ◽  
pp. 2851-2855
Keyword(s):  
Stainless Steel ◽  
Landfill Leachate ◽  
Applied Voltage ◽  
Metal Ion ◽  
Oxygen Demand ◽  
Stainless Steel Electrode ◽  
Electrolysis Time ◽  
Steel Electrode ◽  
Electrode Distance ◽  
Wide Range

Electrocoagulation (EC) process uses direct electric current source between metal electrode submerged in the effluent that results in electrode dissolution, with a suitable pH, metal ion can form a wide range of metal hydroxide and coagulated species that destabilized and dissolved contaminants absorbed. Electrocoagulation (EC) has been working for the percentage removal of BOD (Biochemical oxygen demand)/ chemical oxygen demand (COD) ratio, Color and COD on leachate in a batch Electrocoagulation reactor using stainless steel (SS) electrode. EC technology depends on so many factors such as electrode material, initial pH, applied voltage, inter-electrode distance, and electrolysis time. From the experimental work, results reveal that the maximum percentage of removal achieved were COD and Color 73.5% and 65.0% respectively and increasing BOD/COD ratio 0.11 to 0.62. The optimum inter-electrode distance 1cm with electrode surface area 35 cm2 and optimum electrolysis time of 120 min at optimum applied voltage 12V, stirring speed 250 rpm and pH 9.8. These results proved that the EC process is an appropriate and proficient approach for treating the landfill leachate.

A NEW DESIGN ENHANCES HYDROGEN PRODUCTION BY G. SULFURREDUCENS PCA STRAIN IN A SINGLE-CHAMBER MICROBIAL ELECTROLYSIS CELL (MEC)

2017 ◽  
Vol 79 (5-3) ◽  
Author(s):  
Abudukeremu Kadier ◽  
Mohd Sahaid Kalil ◽  
Azah Mohamed ◽  
Aidil Abdul Hamid
Keyword(s):  
Hydrogen Production ◽  
Applied Voltage ◽  
Renewable Energy Sources ◽  
Geobacter Sulfurreducens ◽  
Electrolysis Cell ◽  
Microbial Electrolysis Cell ◽  
Single Chamber ◽  
Operational Costs ◽  
Wide Range ◽  
Microbial Electrolysis

Microbial electrolysis cell (MEC) is an innovative and green technology to generate hydrogen from a wide range of renewable energy sources and wastewater. At current stage, the performance of these systems is still far from real-world applications. The most likely limiting factors for successful commercialization of this technology are the large internal resistance, high fabrication and operational costs. The aim of the present study was to enhance hydrogen production, reduce the construction and operational costs in MECs via development of a novel MEC design. A single-chamber membrane-free MEC was designed and successfully produced hydrogen from organic substrate using a pure culture: Geobacter sulfurreducens PCA. The MEC system was operated with Platinum (Pt) cathode at applied voltage range of 0.6 V to 1.1 V. Geobacter sulfurreducens PCA strain and sodium acetate used as inoculum and a fuel sources, respectively. The conductivity of electrolyte solution in the MEC was 4.5 mS/cm. Due to an improved the MEC reactor architecture, the maximum hydrogen production rate (HPR) of 3.67 ± 0.03 m3 H2 /m3 d with volumetric current density (IV) of 293.73 ± 1.18 A/m3 was achieved under an external applied voltage (Eap): 1.1 V. The highest overall hydrogen recovery ( ) and overall energy efficiency ( ) were 91.80 ± 1.06% and 66.97 ± 0.09%, respectively. 

Revisiting statistical properties of surf parameter with characteristic wave parameters for single random waves including spectral bandwidth effects

2021 ◽  
pp. 147509022110353
Author(s):  
Dag Myrhaug ◽  
Hong Wang ◽  
Lars Erik Holmedal ◽  
Hongtao Li
Keyword(s):  
Wave Height ◽  
Joint Distribution ◽  
Parametric Model ◽  
Wave Period ◽  
Small Scale ◽  
Spectral Bandwidth ◽  
Joint Distributions ◽  
Wide Range ◽  
Rubble Mound ◽  
Rubble Mound Breakwaters

Results from a comparative study of the joint distribution of surf parameter and wave period are provided. First, two transformed joint distributions of wave height and wave period are compared. One of the distributions is a parametric model originating from a best fit to relatively broad-band field data covering a wide range of wave conditions, whilst the other distribution is theoretically based. It appears that the theoretically based distribution does not represent the features of the parametric model especially well, suggesting that parametric models should be used to describe relatively broad-banded data. Then, the theoretically based joint distribution of wave height and wave period is transformed to the joint distributions of surf parameter with wave height and wave period and it is demonstrated how these distributions are affected by the spectral bandwidth. Finally, the theoretically based distribution of wave height and wave period is also transformed to the joint distribution of wave runup time and wave period due to its relation to the stability of rubble-mound breakwaters. Comparisons are made with a limited set of data representing results from small-scale laboratory experiments related to stability of rubble-mound breakwaters. The agreement between measurements and predictions of the distribution of the surf parameter is fair, whilst the agreement is poorer for the probability of resonance.

OXYGEN FLUX MEASUREMENTS IN ORGANIC SOIL

1980 ◽  
Vol 60 (4) ◽  
pp. 641-650 ◽  
Author(s):  
JAMES A. CAMPBELL
Keyword(s):  
Applied Voltage ◽  
Mineral Soil ◽  
Organic Soil ◽  
Oxygen Flux ◽  
Organic Soils ◽  
Wide Range ◽  
Effective Voltage ◽  
Flux Measurements ◽  
Mineral Soils ◽  
Almost All

Many measurements of oxygen flux in mineral soils have been reported; however, few such measurements have been made in organic soil. Almost all reported measurements of oxygen flux are at constant applied voltage, despite criticism of this technique, possibly due to the complexity of existing techniques for measuring oxygen flux at effective voltage. Equipment suitable for measuring oxygen flux at applied and effective voltage in organic soil was designed, and simplified techniques were developed and tested. As reported for mineral soils, soil resistance is relatively constant spatially and with depth in individual soils. Limited poisoning of the platinum electrode surface occurred after long periods of time and, contrary to previous assumptions, cannot be detected by erratic readings. Unlike mineral soil, the amperage-voltage slopes are constant over a wide range of organic soils, simplifying the technique for estimating oxygen flux at constant effective volatage. Comparison of simultaneous measurements of oxygen flux at constant and effective voltage indicates that oxygen flux measurements at effective voltage were twice those at applied voltage and strongly correlated (r2 = 0.96, n = 22).

scholarly journals Using Of Different Electrocoagulation Cell Configuration Parameters for Treating of Abu-Ghraib Dairy Products Wastewater

2022 ◽  
Vol 961 (1) ◽  
pp. 012059
Author(s):  
Sara Mohannad Abd Al-Hamza ◽  
Hayder Mohammed Abd Al-Hamed
Keyword(s):  
Reaction Time ◽  
Removal Efficiency ◽  
Applied Voltage ◽  
Water Reuse ◽  
Anthropogenic Activities ◽  
Oxygen Demand ◽  
Cylindrical Shape ◽  
Electrode Shape ◽  
Wide Range ◽  
Population Urbanization

Abstract One of the most significant issues that people throughout the world will confront in the future years is a lack of clean and safe water. Anthropogenic activities, in particular, are polluting water systems. With rising population, urbanization, and climate change, water reuse has become a requirement in some areas of the globe, putting pressure on the development of effective water treatment methods for a range of contaminants. High biological oxygen demand (BOD), chemical oxygen demand (COD), oil-grease, and other pollutant loads define dairy sector effluent. Improved technology is required to address these issues. Electrocoagulation is a new type of therapy. It’s simple to use, ecologically friendly, and removes a wide range of contaminants from a variety of water types. The goal of this study was to see how operational factors such applied voltage, number of electrodes, distance between electrodes, electrode shape, and reaction time affected the electrocoagulation of actual dairy effluent. Aluminum and iron electrodes are used for this purpose. It was discovered that raising the applied voltage, reaction time, and decreasing the distance between electrodes improved COD, BOD, EC, TDS, color, and oil-grease removal efficiency. Moreover, switch between square, triangular electrodes and perforated cylindrical. The data show that electrocoagulation is effective at the maximum COD, BOD removal efficiency of first electrode at 20 holes of cylindrical shape is (88.03) %, (87.97) %, respectively. Second triangle shape is (100) %, (100) % respectively. Third square shape is (99.38) %, (99.42) % respectively. the maximum removal of TDS, EC efficiency of first electrode at 20 holes of cylindrical shape is (67.57) %, (62.34) %, respectively. Second triangle shape is (77.45) %, (67.68) % respectively. Third square shape is (81.96) %, (71.25) % respectively. The maximum color and oil-grease removal efficiency of first electrode at 20 holes of cylindrical shape is (100) %, (100) %, respectively. Second triangle shape is (100) %, (100) % respectively. Third square shape is (100) %, (100) % respectively. Electrocoagulation methods for the treatment of dairy wastewaters were shown to be successful in the research. Finally, the findings indicated that electrocoagulation is a technically feasible method for removing contaminants from dairy wastewaters.

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