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دسترسی آزاد مقاله
1 - Effects of mixed electric field on characterization of electrohydrodynamics drying system
Hamid Ghomi Pourya Seyfi Ahmad Khademi Amir HeidariIn this paper, we present a new structure of applying two electrical power supplies to generate ionic wind.In this configuration, two power supplies were applied simultaneously with a modulated voltage to anelectrohydrodynamic (EHD) system then corona discharge paramete چکیده کاملIn this paper, we present a new structure of applying two electrical power supplies to generate ionic wind.In this configuration, two power supplies were applied simultaneously with a modulated voltage to anelectrohydrodynamic (EHD) system then corona discharge parameters and EHD thrust characterizationwas investigated by a corona dryer mechanism. The EHD thrust experiments were performed with a pinto plate and SDBD arrangements. The results show that with the simultaneous application of two powersupplies the drying rate in a drop of water as a standard sample was greatly enhanced and the drying time was reduced. Thus, the total evaporation was occurred in 1 minute in the SDBD structure with a power of 7 watts and in 1.5 minutes in pin to plate structure with a power of 2.5 watts. Eventually, it was observed that the use of mixed electric fields enhances the ionic wind, hence increases the non-thermal evaporation process significantly. Furthermore, the drying rate has grown notably In SDBD configuration. پرونده مقاله -
دسترسی آزاد مقاله
2 - Characterization of argon/air atmospheric pressure capacitively coupled radio frequency dielectric barrier discharge regarding parasitic capacitor at 13.56 MHz
Farshad Sohbatzadeh Saeed Mirzanejhad Hoda Mahdavi Zahra OmidiAbstractIn this paper, uniform argon glow discharge at atmospheric pressure in a diffuse mode driven by a 300-W radio-frequency (13.56 MHz) power supply based on dielectric barrier discharge was investigated. In this work, the effect of the parasitic capacitor on the el چکیده کاملAbstractIn this paper, uniform argon glow discharge at atmospheric pressure in a diffuse mode driven by a 300-W radio-frequency (13.56 MHz) power supply based on dielectric barrier discharge was investigated. In this work, the effect of the parasitic capacitor on the electrical characteristics of the capacitively coupled atmospheric pressure plasma was investigated. It was revealed that more than half of the RF current is parasitic in our system as a characteristic of the capacitively coupled plasma. It was also proved that the discharge resistance and sheath capacitance increase at higher input powers while the impedance decreases. In order to recognize plasma, optical emission spectroscopy apparatus was used. Argon, oxygen, copper, and nitrogen spectrum lines were diagnosed. The plasma gas temperature and electronic excitation temperature were investigated showing a non-equilibrium discharge. پرونده مقاله -
دسترسی آزاد مقاله
3 - Analysis of discharge parameters and optimization study of coaxial DBDs for efficient excimer light sources
Udit Narayan Pal Pooja Gulati Niraj Kumar Mahesh Kumar Vishnu Srivastava Ram PrakashAbstractIn this work, a xenon-filled quartz coaxial dielectric barrier discharge (DBD) tube (ID 6 mm, OD 12 mm) at 400-mbar pressure has been studied at different operating conditions. High-frequency sinusoidal and unipolar pulse-like voltages are applied at the dischar چکیده کاملAbstractIn this work, a xenon-filled quartz coaxial dielectric barrier discharge (DBD) tube (ID 6 mm, OD 12 mm) at 400-mbar pressure has been studied at different operating conditions. High-frequency sinusoidal and unipolar pulse-like voltages are applied at the discharge electrodes for the generation of micro-discharge plasma. Visual images of the discharge and the electrical waveform confirm the diffused-type discharge. The mechanism that is involved in the ignition, development and extinction of DBDs is quantitatively explained by dynamic processes in the discharge. An equivalent electrical model representing the DBD phenomenon has also been used to validate the characteristic discharge parameters. The relative intensity analysis of the Xe continuum peak at wavelength 172 nm in the optical emission spectra of the vacuum ultraviolet region has been carried out for different operating conditions. Approximately three times increment in the radiation is observed in pulse excitation over sinusoidal excitation. It infers that the pulsed excitation of DBD sources is advantageous for excimer light sources. پرونده مقاله -
دسترسی آزاد مقاله
4 - Diagnostic of plasma discharge parameters in helium filled dielectric barrier discharge
Pooja Gulati Udit Narayan Pal Mahesh Kumar Ram Prakash Vishnu Srivastava Vimal VyasAbstractThis paper reports the plasma discharge analysis of a dielectric barrier discharge (DBD) source. Helium is used as a working gas. The analysis is performed at fixed working pressure and operating frequency. The investigations are carried out using sinusoidal sup چکیده کاملAbstractThis paper reports the plasma discharge analysis of a dielectric barrier discharge (DBD) source. Helium is used as a working gas. The analysis is performed at fixed working pressure and operating frequency. The investigations are carried out using sinusoidal supply for the generation of discharges where two current pulses have been observed with different polarities in one period. A homogeneous type of discharge has been observed for different operating conditions in this DBD source. Since in situ diagnostics are not possible due to the small geometries in the used DBD source, the electrical measurements and spectroscopic analysis of the discharge have been performed to analyse the plasma discharge. The electrical analysis has been carried out using equivalent electrical circuit model. The plasma density and temperature within the discharge have been estimated using line ratio technique of the observed visible neutral helium lines. The estimated electron plasma density is found to be in close proximity with the plasma simulation code ‘OOPIC Pro’. پرونده مقاله -
دسترسی آزاد مقاله
5 - Investigation of the effects of pulse repetition frequency in a mixed electric field on a SDBD-like plasma jet
Amir Abbas Heidari Pourya Seyfi Ahmad Khademi Hamid GhomiIn this paper, the design, performance and characterization of a low temperature argon plasma jet with a SDBD-like structure are presented. Based on this structure, the argon plasma jet is generated in a SDBD-like structure with a mixed electric field. SDBD-like structu چکیده کاملIn this paper, the design, performance and characterization of a low temperature argon plasma jet with a SDBD-like structure are presented. Based on this structure, the argon plasma jet is generated in a SDBD-like structure with a mixed electric field. SDBD-like structure, refers to the plasma jet generated by the surface dielectric barrier discharge. The effects of high frequency electric pulse as the main igniter for plasma jet generation and low frequency sinusoidal electric field in order to modify the dynamic behavior of plasma jet are investigated in this paper. The effect of these variations on the plasma jet along with the decrease in pulse repetition frequency were recorded by Schlieren imaging method. This study revealed the important role of decreasing the pulse repetition frequency in the mixed electric field in the SDBD-like plasma jet structure. Increasing the cross-sectional area of the plasma colliding with the target surface is the most important advantage of this structure for the generation of plasma jets. Also, the trend of decreasing plasma column continuity with increasing pulse repetition frequency is another result of this study. Under these conditions, the diameter of the cross section of the plasma jet increases to 9 mm without increasing the consumption of more electrical power and with equal jet length. Finally, the surface hydrophilicity was measured after treatment by plasma jet and the operation resulted in a super-hydrophilic surface. پرونده مقاله -
دسترسی آزاد مقاله
6 - Time-dependent one-dimensional simulation of atmospheric dielectric barrier discharge in N2/O2/H2O using COMSOL Multiphysics
F. Sohbatzadeh H. SoltaniAbstractThe results of time-dependent one-dimensional modelling of a dielectric barrier discharge (DBD) in a nitrogen–oxygen–water vapor mixture at atmospheric pressure are presented. The voltage–current characteristics curves and the production of active species are st چکیده کاملAbstractThe results of time-dependent one-dimensional modelling of a dielectric barrier discharge (DBD) in a nitrogen–oxygen–water vapor mixture at atmospheric pressure are presented. The voltage–current characteristics curves and the production of active species are studied. The discharge is driven by a sinusoidal alternating high voltage–power supply at 30 kV with frequency of 27 kHz. The electrodes and the dielectric are assumed to be copper and quartz, respectively. The current discharge consists of an electrical breakdown that occurs in each half-period. A detailed description of the electron attachment and detachment processes, surface charge accumulation, charged species recombination, conversion of negative and positive ions, ion production and losses, excitations and dissociations of molecules are taken into account. Time-dependent one-dimensional electron density, electric field, electric potential, electron temperature, densities of reactive oxygen species (ROS) and reactive nitrogen species (RNS) such as: O, O−, O+, O2-documentclass[12pt]{minimal} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{upgreek} setlength{oddsidemargin}{-69pt} egin{document}$$ { ext{O}}_{2}^{ - } $$end{document}, O2+documentclass[12pt]{minimal} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{upgreek} setlength{oddsidemargin}{-69pt} egin{document}$$ { ext{O}}_{2}^{ + } $$end{document}, O3, N,N2+documentclass[12pt]{minimal} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{upgreek} setlength{oddsidemargin}{-69pt} egin{document}$$ { ext{N}}, { ext{N}}_{2}^{ + } $$end{document}, N2s and N2-documentclass[12pt]{minimal} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{upgreek} setlength{oddsidemargin}{-69pt} egin{document}$$ { ext{N}}_{2}^{ - } $$end{document} are simulated versus time across the gas gap. The results of this work could be used in plasma-based pollutant degradation devices. پرونده مقاله -
دسترسی آزاد مقاله
7 - Inactivation of Aspergillus flavus spores in a sealed package by cold plasma streamers
F. Sohbatzadeh S. Mirzanejhad H. Shokri M. NikpourAbstractThe main objective of this study is to investigate the inactivation efficacy of cold streamers in a sealed package on pathogenic fungi Aspergillus flavus (A. flavus) spores that artificially contaminated pistachio surface. To produce penetrating cold streamers, چکیده کاملAbstractThe main objective of this study is to investigate the inactivation efficacy of cold streamers in a sealed package on pathogenic fungi Aspergillus flavus (A. flavus) spores that artificially contaminated pistachio surface. To produce penetrating cold streamers, electric power supply was adapted to deposit adequate power into the package. The plasma streamers were generated by an alternating high voltage with carrier frequency of 12.5 kHz which was suppressed by a modulated pulsed signal at frequency of 110 Hz. The plasma exposition time was varied from 8 to 18 min to show the effect of the plasma treatment on fungal clearance while the electrode and sample remained at room temperature. This proved a positive effect of the cold streamers treatment on fungal clearance. Benefits of deactivation of fungal spores by streamers inside the package include no heating, short treatment time and adaptability to existing processes. Given its ability to ensure the safety and longevity of food products, this technology has great potential for utilization in food packaging and processing industry. In this study, moisture and pH changes of pistachio samples after plasma streamers treatment were also investigated. پرونده مقاله -
دسترسی آزاد مقاله
8 - Study of an argon dielectric barrier discharge reactor with atmospheric pressure for material treatment
Maryam Hosseinpour Akbar ZendehnamAbstractIn this study, effects of the variation in the dielectric barrier discharge’s (DBD) gap distance and the nature of dielectric layers which cover both of the reactor electrodes on the electron density, mass fraction of excited argon atoms across the discharge gap چکیده کاملAbstractIn this study, effects of the variation in the dielectric barrier discharge’s (DBD) gap distance and the nature of dielectric layers which cover both of the reactor electrodes on the electron density, mass fraction of excited argon atoms across the discharge gap, mean electron energy, ion and electron current density, and electron temperature are investigated at atmospheric pressure. In order to find the optimal reactor gap, the DBD’s average power consumption is studied. The achievements show that when the value of dielectric constant is increased from 7.6 to 10, discharge gap of 1 mm still demonstrates the maximum power consumption, which can be considered as the optimum discharge gap. To optimize the characteristics of one-dimensional modeling of DBD system for material treatment, various types of materials with different values of the permittivity [aluminum, glass (quartz) and silicon] are embedded in the discharge gap between the two electrodes. In this case, the reactor gap is changed from 0.5 mm to 2 mm, while the dielectric constant of the dielectric layers which cover both of the metallic electrodes is assumed to be 10. Compared to the other examined materials, our numerical results illustrate that the treated material with higher value of the relative permittivity (silicon) has greater influences on the variations in the electron density, argon ion density and also total plasma current density than in the values of excited argon atom density, mass fraction of excited argon atoms and also average power consumption. پرونده مقاله -
دسترسی آزاد مقاله
9 - بررسی عوامل موثر در تصفیه اکسیدهای نیتروژن در یک راکتور پلاسمای سرد
رسول یاراحمدی سید باقر مرتضوی محمدرضا امید خواه حسن اصیلیان علی خوانینهدف از این تحقیق تصفیه و حذف اکسیدهای نیتروژن در راکتور پلاسما در شرایط اتمسفریک و غیر حرارتی است. این فن آوری علاوه بر قابلیت کاهش مصرف انرژی در فرایند حذف آلاینده ها، دارای انعطاف پذیری ویژه در تصفیه و تقلیل آلاینده های فرعی به طور هم زمان است. در این تحقیق به منظور چکیده کاملهدف از این تحقیق تصفیه و حذف اکسیدهای نیتروژن در راکتور پلاسما در شرایط اتمسفریک و غیر حرارتی است. این فن آوری علاوه بر قابلیت کاهش مصرف انرژی در فرایند حذف آلاینده ها، دارای انعطاف پذیری ویژه در تصفیه و تقلیل آلاینده های فرعی به طور هم زمان است. در این تحقیق به منظور تبدیل موثر اکسید های نیتروژن(NOX)، از فرایند پلاسمای نوع تخلیه با مانع دی الکتریک[1](DBD) استفاده شده است. در اثر برخورد الکترون ها با جریان هوای حاوی اکسید های نیتروژن، رادیکال ها و مولکول های فعال در یک حجم محدود وتحت کنترل (راکتور پلاسما) تولید و سپس در حضور هیدرو کربن احیا کننده عمل تبدیل و تصفیه انجام می شود. در این تحقیق از بین عوامل موثر بر تبدیل NOx در محیط پلاسما متغیرهای دما، سرعت فضایی، نسبت مولی گاز پروپان به اکسید های نیتروژن و ولتاژ مورد بررسی قرار گرفت. اهمیت تاثیر عامل دما، اختلاف ولتاژ و گاز احیا کنند به ترتیب مشخص شد. سرعت فضایی در محدودهh-123000-11500 تاثیر معنی داری بر تبدیل آلودگی NOx نشان نداد. بررسی نتایج نشان می دهد که شرایط بهینه به منظور تبدیل NO به N2 ، O2 و NO2 عبارتند از، دمای C °180، نسبت مولی برابر پروپان و اکسید های نیتروژن و ولتاژ 10 کیلو ولت که در این حالت درجه تبدیل بهینه 78/0 با انحراف معیار 12/0 حاصل شد . در حالی که شرایط بهینه برای تبدیل و تصفیه NOx دمای C ° 180 ، نسبت مولی گاز پرو پان به اکسید های نیتروژن برابر 3/0 با ولتاز 5 کیلو ولت می باشد . در این حالت درجه تبدیل بهینه برابر53/0 با انحراف معیاری معادل 15/0 به دست آمد. پرونده مقاله -
دسترسی آزاد مقاله
10 - Electrical Discharges: An Emerging Modality in Sterilization, Disinfection, and Therapeutics
Soumyadeep Sarkar Niharika Verma Pawan TiwariElectrical discharges are the key mechanism to the generation of atmospheric pressure plasmas which are further classified as equilibrium and non-equilibrium plasmas, also referred to as thermal and non-thermal plasmas. The technological advancement of non-thermal plasm چکیده کاملElectrical discharges are the key mechanism to the generation of atmospheric pressure plasmas which are further classified as equilibrium and non-equilibrium plasmas, also referred to as thermal and non-thermal plasmas. The technological advancement of non-thermal plasma has extended its potential clinical non-invasive applications in a multitude of disciplines such as dermatology, ophthalmology and oncology, etc. to bolster tissue generation, refraction error correction and necrosis of the cancerous cells in the domain of plasma medicine, respectively. A fundamental on the various types of discharges and their mechanism is investigated. A perspective on the application of non-thermal plasmas in the domains such as sterilization and disinfection is presented in this review. We have focused on the plasma therapeutics and its significance as a clean and dry therapy to treat superficial skin diseases via the mechanism of proliferation of basal skin cells and prothrombin stimulation to cauterize the blood through Argon Plasma generated by Argon Plasma Coagulator. We propose to fabricate atmospheric pressure plasma devices and understanding of the associated plasma radicals that aids in the activation of biochemical and biomolecular reactions to treat the cutaneous and sub-cutaneous diseases. پرونده مقاله -
دسترسی آزاد مقاله
11 - اثر پلاسمای سرد اتمسفری بر میزان رشد و قدرت تشکیل بیوفیلم در استافیلوکوکوس اورئوسهای جداشده از شیر گاو مبتلا به ورم پستان
فرهاد جهاندیده جلال شایق سمیه حسین زادهاستافیلوکوکوس اورئوس بهعنوان یکی از باکتری های مهم بیماری زا در صنعایع شیر است که قادر به تولید بیوفیلم می باشد. بیوفیلم تولید شده توسط این باکتری باعث مقاومت آن در برابر عوامل ضدمیکروبی میگردد. غیرفعال کردن میکروارگانیسم ها با استفاده از پلاسمای سرد اتمسفری یکی از رو چکیده کاملاستافیلوکوکوس اورئوس بهعنوان یکی از باکتری های مهم بیماری زا در صنعایع شیر است که قادر به تولید بیوفیلم می باشد. بیوفیلم تولید شده توسط این باکتری باعث مقاومت آن در برابر عوامل ضدمیکروبی میگردد. غیرفعال کردن میکروارگانیسم ها با استفاده از پلاسمای سرد اتمسفری یکی از روش های جدید در صنعایع غذایی می باشد. در این مطالعه جهت بررسی اثر ضدباکتریایی و ضدبیوفیلمی پلاسمای سرد اتمسفری، از دستگاه تخلیه سد دیالکتریک استفاده شد. تعداد 20 جدایه استافیلوکوکوس اورئوس بهدستآمده از شیر گاوهای مبتلا به ورمپستان بالینی، در بازه های زمانی 5 تا 20 ثانیه در معرض پلاسما قرارگرفت و اثر ضدباکتریایی آن با اندازه گیری قطر هاله مهار رشد محاسبه شد. برای ارزیابی اثرات ضدبیوفیلمی، جدایه ها بهمدت 5 ثانیه تحت تیمار با پلاسما قرار گرفتند و پس از 24 ساعت میزان تشکیل بیوفیلم بررسی شد. نتایج نشان داد که با افزایش زمان شارش پلاسما بر جدایه ها، کاهش قابلتوجهی در میزان رشد باکتری ها مشاهده میشود. همچنین آنالیز آماری نتایج حاصل از الایزا ریدر نشان داد که در معرض قرارگیری جدایه ها با پلاسما بهطور معنی داری (p < 0.05)باعث کاهش تولید بیوفیلم شده است. این نتایج حاکی از آن است که پلاسما می تواند جایگزین مناسبی برای روش های آلودگی زدایی حرارتی باشد. با اینحال، کاربرد آن مستلزم انجام مطالعات بیشتر با هدف تعیین شدت و مدتزمان مواجهه میکروارگانیسم ها با پلاسما است. پرونده مقاله
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