In 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

Zirconium carbide (ZrC) is promising candidate materials in advanced nuclear reactors as fuel cladding and plasma facing materials. It can employ to increase ductility and fracture toughness of tungsten as prominent candidate of plasma facing materials in ITER and DEMO future fusion reactors. In this study, ZrC thin films were deposited through DC magnetron sputtering at different substrate temperatures. Argon and acetylene are respectively employed as the sputtering gas and reaction gas to produce ZrC from a Zr target. The phase and structure, crystallite size, displacement density, microstrain, and lattice's constant of the produced thin films were determined using X-ray diffraction (XRD) analysis. Raman spectroscopy was also used to identify various structures and chemical bonds. Furthermore, the analysis of Raman peaks associated with amorphous carbon bonds revealed that the ratio of sp3/sp2 carbon bonds increases by increasing temperature from 100°C to 180°C, which substantially affects the hardness of the thin films. Field Emission Scanning electron microscopy (FESEM) was used to measure the cross-sectional area and thickness of the thin films, and it was discovered that increasing temperature enhances the thickness of the thin films. The elemental analysis of ZrC thin films that was performed using X-ray energy dispersive spectroscopy (EDS) demonstrated the atoms that constitute the thin film, and their changes with temperature variations. پرونده مقاله

In 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

AbstractIn this paper, we have presented a new power supply structure for ozone generation in a dielectric barrier discharge reactor, so that a high-frequency pulse electric field is applied on the reactor simultaneously with a low-frequency sinusoidal electric field, referred as mixed electric field. In this study, the effect of mixed electric field variation on ozone production efficiency has been investigated and increasing effects on ozone production have been observed when the reactor temperature decreases. This performance has been achieved by modifying the mechanism of electrical discharge and decrease in filamentary discharge in plasma. By examining the spectral lines of atomic emission spectroscopy, the highest peak of the oxygen (O I) spectral lines was observed in the spectrum of the mixed electric field structure. Also by qualitative comparison of the spectral lines, the lowest intensity for the oxygen (O II) spectral lines was observed in this spectrum. Practically, this technique allows us to achieve higher ozone efficiency with less electrical power. Eventually, with the electric field mixing, we were able to achieve a 4.5% efficiency with 7.7 g/h of ozone generation at 2 kW/m2 with 2 L/min injector oxygen. In addition, by electric field mixing, we were able to reduce the reactor temperature from 66 to 41 °C. پرونده مقاله

AbstractThe main objective of the current paper is to describe the effect of external inductance (EI) on the current discharge waveforms of HiPIMS at different pulse-on time (Pon) and its relation with static deposition rate and topographical properties of deposited titanium thin films, which is investigated by scanning electron microscope and atomic force microscope. It has shown that the higher the EI, independent of the Pon, the higher the peak power is. The delay time also extensively increases when an EI is implemented into the circuit. However, the rise time does not have a linear dependency with the EI and its behavior changes to some extent at different Pon. By increasing the EI from zero to 30 mH at Pon = 60 μs, the peak power subsequently rises from 11 to 32 kW at constant time-average power. Meanwhile, the deposition rate decreases from 8.5 to 1.5 nm/min, which is mainly attributed to the metal ions return to the target surface and nonlinear dependency of sputtering yield with applied voltage. It was also revealed that the higher peak power has no special effect on the surface roughness of titanium thin films deposited by HiPIMS. پرونده مقاله

مقدمه: به دلیل بالا بودن میزان اسیدهای چرب غیر اشباع در روغن سویا، احتمال رخداد اکسیداسیون در این محصول بالا و کاربرد آن¬ در صنعت غذا محدود می¬باشد؛ لذا جهت افزایش پایداری اکسیداتیو و توسعه کاربردهای غذایی آن، فرایندهای اصلاحی متعددی مورد توجه قرار گرفته است که در این بین فرایند هیدروژناسیون با استفاده از تکنولوژی نوین پلاسمای سرد جهت تولید روغن نیمه هیدروژنه با اسیدهای چرب ترانس بسیار پایین، مورد توجه قرار گرفته است. مواد و روش¬ها: در این پژوهش به بررسی اثر استفاده از پلاسمای سرد تخلیه مانع دی الکتریک سطحی با استفاده از تیمار 13 ساعته، ولتاژ 15کیلوولت و گاز هیدروژن 50% و نیتروژن 50% بر روی خصوصیات فیزیکیوشیمیایی روغن سویا پرداخته شد. در بازه¬های زمانی مشخص از نمونه¬های تیمار شده نمونه برداری گردید و ترکیب اسیدهای چرب، اندیس یدی، ضریب شکست، محتوی کارتنوئید، نقطه ذوب، اندیس پراکسید، محتوی توکوفرول و محتوی استرول آن¬ها اندازه گیری شد. یافته¬ها: نتایج حاصله نشان داد که در اثر استفاده از تیمار پلاسمای سرد تخلیه مانع دی الکتریک سطحی 13 ساعته، محتوی اسیدهای چرب غیر اشباع از 62/58% به 24/40%، محتوی کارتنوئید ازpmm 38/26 به ppm 32/6، ضریب شکست از 4672/1 به 4400/1، اندیس یدی حدود از 64/129 به 45/100، میزان استرول کل از pmm 51/2636 به pmm 86/2315 به طور معناداری کاهش و عدد پراکسید از 4/2 به 8/5 meq O2/kg oil و نقطه ذوب به C° 7 افزایش یافتند(p<0.05). همچنین میزان اسیدهای چرب ترانس تولید شده به صورت بسیار جزئی (85/0 %) مشاهده گردید. نتیجه گیری: با توجه به نتایج بدست آمده از بررسی¬های صورت گرفته، می¬توان از تیمار پلاسما دی¬بی¬دی سطحی به عنوان فناوری نوین جهت هیدروژناسیون روغن¬ها به همراه رنگبری استفاده نمود. پرونده مقاله