Cold Plasma

In this work, modern technologies use plasma jets in industrial and medical applications for their exciting effectiveness, the properties of which are determined by the type of gas and metal placed as electrodes in the system, as they operate under atmospheric pressure and generate cold plasma, and by using silicon metal and argon gas connected to a high voltage power supply, the current was changed to generate plasma and characterize the produced optical spectrum and compare the effect of this change on its parameters (temperature and electron density) and know the processes associated with its generation. With an applied voltage of 11 kV and using optical emission spectroscopy (OES), the spectral diagnostics were recorded to describe the resulting plasmonic properties. Using DC current, the peak spectral density shown by the results was higher than the alternating current. By comparing the effect of the type of current for the same gas and silicon metal on the parameters, it was found that the values of temperature and electron density at direct current were 2.22-2.67 eV, 3.238×10 16-3.305×10 16 cm-3 , at a gas flow rate of 0.5-2 L/min. At the same flow rate and by applying AC current, it was found that the temperature and electron density were 1.018-1.093 eV, 5.026×10 16-6.897×10 16 cm-3. Through the comparative study, the effect of direct current was greater on the plasma parameters than alternating current, since alternating current works in the form of an intermittent sinusoidal pulse that affects the movement of charges and thus causes a momentary interruption in the generation of plasma, which leads to cooling the plasma column and reducing the electron density.

The physicochemical properties of plasma-activated water (PAW) and the mechanism of PAW on the inactivation of Pseudomonas fluorescens were investigated. The results demonstrated that as activation time and output voltage increased, the electrical conductivity (EC) and oxidation-reduction potential (ORP) of PAW increased, while its pH decreased. When the activation condition was 20 kV for 30 min (PAW30), the content of active substances of the PAW was the highest (P < 0.05). The concentrations of NO 2-, NO 3-, and H 2 O 2 were high as 0.43 μg/mL, 2.46 μg/mL, and 0.837 μg/mL, respectively. After the PAW30 treatment for 30 min, the population of P. fluorescens was decreased by 2.27 log 10 CFU/mL when the initial inoculation volume was 4.38 log 10 CFU/mL. PAW oxidative stress disrupted the balance of the intracellular redox, ion concentration, and pH, leading to the breakdown of cell wall and membrane integrity, ultimately causing bacterial inactivation. These are important mechanisms by which PAW exerts its bactericidal effect. Industrial relevance: The aim of this study was to clarify the optimal preparation conditions for PAW, and its mechanism of killing P. fluorescens. These results contribute to our understanding of the control of spoilage organisms in aquatic products by PAW. In the raw material treatment stage of aquatic product processing, PAW can be used to clean and soak raw materials to kill microorganisms on their surfaces of raw materials. Therefore, PAW can be applied as a green cleaning technology to improve the hygienic quality of aquatic products.

Background: Vitiligo is defined as an idiopathic, autoimmune condition characterized by destruction of the melanocytes. Melanocytes in the eye are present in two layers, the uvea and retinal pigment epithelium. Ocular findings in vitiligo have been studied to a very limited extent. Aim: To study the clinical pattern of ocular manifestations in cases diagnosed with vitiligo and to reveal any demographic or clinical feature that might suggest an association or risk factor for ocular involvement in cases of vitiligo. Material and methods: It was a Prospective case control observational study. 75 cases of vitiligo and 75 controls with similar demography were included. Cases were evaluated for relation of ocular involvement with type and duration of vitiligo, location of lesions and demographic characteristics. Simultaneously ocular manifestations of the control group were tested, for significance of the demographic characteristics and analyzed using chi-square test. Results and Conclusions: Ocular involvement in vitiligo is asymptomatic. In 75 diagnosed cases of vitiligo male to female ratio was 1:1.34 and 11 to 30 years age group had maximum number of cases. Iris hypopigmentation (33.3%) was the most frequent followed by fundus changes(30.6%) and hyper-pigmentation of the anterior chamber angle(20%). In the fundus peripapillary chorioretinal atrophy(18/23 cases) is the most common, diffuse hypopigmentation, background tessellation and temporal crescent being the others. The ocular involvement was found to be more in cases with vitiligo lesions located around the orbital or oral or genital areas. The duration of vitiligo and demographic characteristics are not the risk factors for ocular involvement in vitiligo.

Presented paper describes a numerical study of discharge plasma motion. This non-stationary phenomenon with steep gradients and sharp peaks in unknowns is described as a coupled problem of convection-diffusion equation with source term for electron, ion densities and Poisson's equation for electric potential. The numerical method is 2nd order of accuracy in space and time and it uses dynamical adaptation of unstructured triangular mesh. Results of numerical studies included size of computational domain, type of boundary conditions and numerical convergence test are presented.

Ante el aumento en todo el mundo del número de infecciones bacterianas y fúngicas resistentes a fármacos, cada vez cobra mayor importancia el desarrollo de alternativas terapéuticas frente a este tipo de agentes infecciosos. El avance hacia el desarrollo de métodos sostenibles físicos, o de otro tipo, que permitan eliminar estos agentes problemáticos parece ser cada vez más esencial el tratamiento con Plasma Frío.
El plasma frío tiene múltiples aplicaciones en el campo de la medicina y la investigación científica. Las ventajas van desde su uso en tratamientos de esterilización y cicatrización de heridas como en la descomposición de
contaminantes del aire.

Se puede decir que el plasma frío es el cuarto estado de la materia, después del sólido, líquido y gaseoso. De hecho, diversas fuentes refieren que este estado de la materia tiene la particularidad de contener
partículas con diferentes niveles de energía, lo que puede ser aprovechado para diversas aplicaciones.

Escherichia coli in raw beef were assessed. A cocktail of E. coli strains was inoculated onto gamma-irradiated beef and enumerated immediately after each intervention and during storage at 4°C for 7 days. Of the physical interventions, silver-containing antimicrobial packaging and ozone gas treatment did not show significant antimicrobial effects, however cold plasma treatment reduced E. coli levels by 0.9 and 1.82 log 10 CFU/cm 2 after 2 and 5 min treatments, respectively. A phage cocktail reduced E. coli counts by 0.63 and 1.16 log 10 CFU/g after 24 h storage at 4 and 12 o C, respectively. Of the natural interventions, vinegar and lactic acid (5%) washes for 5 min caused reductions of ~1 log 10 CFU/g immediately after treatment, whereas lactoferrin and nisin treatments, separately or in combination, had insignificant antimicrobial effects. Nanoemulsions containing carvacrol or thyme essential oils caused immediate E. coli reductions of 1.41 and 1.36 log 10 CFU/g, respectively, plus a progressive reduction in viable numbers during storage at 4 o C. Our findings suggest that cold plasma, bacteriophages, vinegar, lactic acid, or carvacrol and thyme essential oil nanoemulsions could potentially be of use to the beef industry for controlling pathogenic E. coli contamination.

A plasma gas bubble-in-liquid method for high production of selectable reactive species using a nanosecond pulse generator has been developed. The gas of choice is fed through a hollow needle in a point-to-plate bubble discharge, enabling improved selection of reactive species. The increased interface reactions, between the gas-plasma and water through bubbles, give higher productivity. H 2 O 2 was the predominant species produced using Ar plasma, while predominantly NO À 3 and NO 2 were generated using air plasma, in good agreement with the observed emission spectra. This method has nearly 100% selectivity for H 2 O 2 , with seven times higher production, and 92% selectivity for NO À 3 , with nearly twice the production, compared with a plasma above the water.

We consider the interaction of subpicosecond relativistically strong short laser pulses with an underdense cold unmagnetized electron plasma. It is shown that the strong plasma inhomogeneity caused by laser pulses results in the generation of a low frequency (quasistatic) magnetic field. Since the electron density distribution is determined completely by the pump wave intensity, the generated magnetic field is negligibly small for nonrelativistic laser pulses but increases rapidly in the ultrarelativistic case. Due to the possibility of electron cavitation (complete expulsion of electrons from the central region) for narrow and intense beams, the increase in the generated magnetic field slows down as the beam intensity is increased. The structure of the magnetic field closely resembles that of the field produced by a solenoid; the field is maximum and uniform in the cavitation region, then it falls, changes polarity and vanishes. In extremely dense plasmas, highly intense laser pulses in the self-channeling regime can generate magnetic fields-100MG and greater.

Considering the urgent need for green energy carriers, hydrogen became a promising substitute for fossil fuel production via sustainable approach. Therefore, developing efficient photocatalysts using solar energy is the main issue. Here, we report experimental and computational studies on nature and influence of oxygen vacancies in different atomic layers of defective TiO 2-x nanotubes photocatalysts. Although there are several studies that opened a new avenue to understand how to fabricate suboxide TiO 2-x , there is no any comparative study reported on two main oxygen reduction techniques yet: cold plasma treatment and thermal hydrogenation. Oxygen vacancies and Ti 3+ species produced by plasma reduction in a mixed Ar/H 2 (90/10) under pressure of 10 − 3 Torr efficiently increase charge carrier life time (at optimum 15 W power) resulting in higher H 2 production rate and significant incident photon to current efficiency (60%) in comparison with point defects produced by hydrogenation treatment. Various techniques utilized to fabricate oxygen deficient TiO 2-x can lead to the creation of defects in specific atomic layers within the crystal structure. Therefore, we develop an ab initio model of the oxygen vacancies' formation at different depths of TiO 2 slabs to study the effect of defects' position in the crystal lattice on electronic structure against energy levels of water splitting reaction. This research provides a new and deep insight for designing suboxide black TiO 2-x for efficient photocatalytic reactions especially for green energy production and environmental remediation.

The Unruh effect posits that an accelerating observer perceives blackbody radiation where an inertial observer would detect none. Exploiting this phenomenon within plasma physics could unlock unprecedented control over plasma dynamics. This thesis presents a theoretical and experimental framework for using attosecond lasers to generate accelerated magnetic monopole-like excitations within a plasma, creating an intensely charged orb of light capable of defying gravitational forces. By meticulously manipulating the acceleration of these excitations, we aim to control the intensity of Unruh radiation, establishing feedback loops that influence both the plasma dynamics and the behavior of the monopole. Furthermore, we integrate the concept of force-free time-harmonic plasmoids, as explored in advanced plasma physics, into our framework. By utilizing these plasmoids, which are stable, self-contained plasma structures with force-free magnetic fields, we propose a novel method to sustain and manipulate magnetic monopole-like excitations. This integration allows for groundbreaking findings in plasma stability, energy transfer mechanisms, and could potentially lead to conditions conducive to fusion reactions at lower temperatures. This self-sustaining mechanism could revolutionize our understanding of plasma states and offers a potential pathway to achieving conditions akin to cold fusion. The work builds upon and extends the theories of Winterberg, Puthoff, Davis, White, and Pais, providing a comprehensive approach to harnessing quantum vacuum effects in practical applications.

Plasma surface treatment has been extensively applied in the textile industry for the modification of polymer materials. In this study low-temperature plasma (LTP) is used for surface treatment of polyamide/ polyurethane (PA/PU) knitted fabric. The envisaged plasma effect is an increase in the surface energy of the treated textile, leading toward improved hydrophilic properties. The knitted fabric was treated by LTP using three non polymerizing gases: oxygen, air, and carbon dioxide. After plasma treatment, wettability of samples was tested through their wicking properties measuring capillary rise after water bath contact. The PA/PU knitted fabric samples treated with different plasma gases exhibited different hydrophilic performances. The influence of plasma variables (discharge power, time, pressure) was investigated. Although the chemical characteristics of elastan (PU) and nylon (PA) threads are different, the study has demonstrated that plasma treatment can in the same time alter the surface-wetting behavior of both the components of the knitted fabric. It was also shown how these treatments can be regulated to produce the desired level of hydrophilicity dependently on the request application.

Through the effort to obtain clues toward understanding of transport of cold plasma in the near-Earth magnetotail under northward IMF, we find that twocomponent protons are observed in the midnight plasma sheet (−10>X GSM >−30 R E , |Y GSM |<10 R E) under northward IMF by the Geotail spacecraft. Since the twocomponent protons are frequently observed on the duskside during northward IMF intervals but hardly on the dawnside, those found in the midnight plasma sheet are thought to come from the dusk flank. The cold proton component in the midnight region occasionally has a parallel anisotropy, which resembles that in the tail flank on the duskside. The flows in the plasma sheet with two-component protons were quite stagnant or slightly going dawnward, which supports the idea that the observed two-component protons in the midnight region are of duskside origin. Because the two-component protons in the midnight plasma sheet emerge under strongly northward IMF with the latitudinal angle larger than 45 degrees, and because the lag from the strongly northward IMF to the emergence can be as short as a few hours, we suggest that prompt plasma transport from the dusk to midnight region occurs under strongly northward IMF. We propose that the dawnward flows result from viscous interaction between the high-latitude portion of the plasma sheet and the lobe cell. Another candidate for plasma transport process from the dusk to the midnight region is turbulent flow due to vortical structures of the Kelvin-Helmholtz instability that developed around the dusk low-latitude boundary under strongly northward IMF. In addition, we also suggest that gradual cooling of hot protons under northward IMF is a global phenomenon in the near-Earth magnetotail.

This study investigated into the antioxidant and antimicrobial properties of Origanum onites essential oil (OEO) and the application of cold atmospheric plasma (CAP) on Iranian white cheese quality during storage at 4°C for 45 days. OEO contains 28.43 ± 0.34 mg GAE/g dw and exhibited antioxidant and antimicrobial activity in in vitro tests. Iranian white cheese inoculated with Escherichia coli, Listeria monocytogenes, Salmonella typhimurium, and Staphylococcus aureus followed by the addition of OEO at two concentrations of 2000 and 3000 ppm, and then treated by CAP for 3 and 7 min. Samples were stored at 4°C. pH, thiobarbituric acid value (TBA), L * , a * , b * color indexes, microbial count, and sensory properties of cheese samples were evaluated on days 0, 7, 15, 30, and 45. Te pH value, L * , a * , b * indexes and sensorial properties of all samples decreased over time, while the TBA value and bacterial count increased. Te physiochemical, microbial, and sensorial fndings suggested that a combination of OEO (2500 ppm) and CAP (3 min) could be helpful in the induction of microbial growth and oxidative reactions in Iranian white cheese.

One of the major concerns in the COVID‐19 pandemic is related to the possible transmission in poorly ventilated spaces of SARS‐CoV‐2 through aerosol microdroplets, which can remain in the air for long periods of time and be transmitted to others over distances &gt;1 m. Cold atmospheric pressure plasmas can represent a promising solution, thanks to their ability in producing a blend of many reactive species, which can inactivate the airborne aerosolized microorganisms. In this study, a dielectric barrier discharge plasma source is used to directly inactivate suitably produced bioaerosols containing Staphylococcus epidermidis or purified SARS‐CoV‐2 RNA flowing through it. Results show that for low residence times (&lt;0.2 s) in the plasma region a 3.7 log R on bacterial bioaerosol and degradation of viral RNA can be achieved.

Pharmaceutical development and therapeutic delivery as they pertain to nanomedicine predominantly involve the use of nanometer-sized (1-100nm) structures or complexes comprised of two or more constituents whose goal is to deliver a specific therapeutic to a targeted site for localized treatment. This illustrates one of the predominant underlying paradigms in nanomedicine: increased efficacy through targeted therapeutic delivery. With the advent of nanobiotechnology the precisely targeted delivery of pharmaceuticals and therapeutic agents can be achieved through a myriad of approaches which can be delineated by the level of bio-activity beginning with the nano-scale dispersion of pharmaceuticals. The primary constituent of nano-scale medicinal complexes is the pharmaceutical itself with the other contributing as a uni-functional "vehicle" for transport; a bi-functional natural or synthetic biodegradable vesicle or "shell" for encapsulation and timed release; or multi-functional components which include surface modification of said vesicle/shells for target-specific binding and/or conjugated with a contrast or fluorescent agent for imaging and/or tracking of drug mobility. This review will focus on cutting-edge nanostructured drug delivery systems for various biomedical applications. In addition, nanobiotechnology and its role in mediating tissue regeneration will be introduced. Recent awarded patents and their role in nanotechnology and nanomedicine development will be discussed.

Cold atmospheric pressure plasmas have emerged as a promising new tool for medical applications. Compared to conventional thermal plasma, such as arc coagulators and desiccators, cold plasma can be more selective in its application and may be used for effective sterilization of skin and wound tissue, wound healing and tissue regeneration, cancer treatment and blood coagulation. One of the key questions that has to be answered before these plasma technologies are introduced in medical practice is the safety of plasma treatment of living tissues, i.e. toxic dose levels of plasma exposure should be determined. It is well established that porcine (pig) skin closely resembles human skin; hence we evaluated the potential toxic effects of plasma treatment on intact and wounded skin in a Yorkshire pig model. Varying doses of Floating Electrode Dielectric Barrier Discharge (FE-DBD) and microsecond Pin-to-Hole Spark Discharge (PHD) plasmas were applied to determine a dosage regime where tissue damage occurs.

A simple technique is tested to improve the contractile effect of a cold plasma jet on acute wounds of mice. Distilled water on the order of microliters is dropped onto wounds before treatment. To assess the fate of the water, an infrared thermal imager is applied. To evaluate the healing effect, macroscopic and immunohistological studies are conducted. Regarding the wound contractile effect, we show that combination treatment of plasma with dropped water seemed to have a greater effect than plasma treatment alone. Plasma may modify the wound surface through such water, chemically and physically. The histological stiffness of the wound surface during maturation and remodeling, however, may also influence the fate of the water during treatment.

Cold plasma is a novel non-thermal technology for the food and packaging industry. In this study, the effects of argon glow discharge plasma on the mechanical properties, surface topography, chemical composition, film hydrophilicity, film solubility, and barrier properties of the starch films were examined. Plasma treatment improved Tensile Strength (TS) of the starch film. In contrast to TS, elongation at the break of the plasmatreated films remained unchanged. The surface roughness of starch film increased after plasma treatment. An apparent increase in the surface hydrophilicity was observed due to formation of oxygen-containing polar groups. FTIR analysis confirmed the increase in the oxygen containing groups in plasma-treated starch film. However, film surface hydrophilicity caused no significant change in the solubility of films. No significant difference was found in the barrier properties of the starch films. The evaluation of films modifications by glow discharge plasma will contribute to in-package decontamination studies of food products by plasma.

In Europe, inappropriate user behaviours in the operation of wood-burning stoves (WBSs) results in substantial energy losses where fireplaces and conventional stoves are major contributors to undue emissions of health damaging fine particulate matter (PM2.5). The design and adoption of cleaner WBSs are relevant issues to save energy and avoid greenhouse gas (CO2e) emissions. This work compares the operating performance of 3 types of biomass stoves used in Europe in their interaction with dwellings. Field studies were conducted in 24 houses in Portugal and Denmark to analyse wood-burning behaviours and their contribution to residential heating. Laboratory and energy simulations were performed to study their thermal efficiency, PM2.5 emissions and the influence of their usage on the indoor climate. This work shows that the operation of enclosed stoves in uninsulated Iberian homes emit more PM2.5 than the Ecodesign thresholds and cannot provide a stable comfort temperature. Despite red...

Cold plasma technology is an emerging food processing treatment which devises wide range of applications especially in various food processing sectors. Cold plasma is known to have greater effects towards the microbial decontamination of various food products to ensure the food safety and shelf life to consumers. Cold plasma uses several reactive gaseous species which are likely less ionised for the inactivation of microbe’s present in meats, poultry, fruits, and vegetables. This review paper will cover the concepts and underlying principles, applications in food, critical parameters, advantages and limitations when this technique is employed. Though, cold plasma technology holds inordinate ability towards decontamination of foods, the chemistry of reactive gaseous species with foods during cold plasma treatment, effects of CPT (Cold Plasma Technology) on environment and its economic impact has to be studied evidently through further research to gain its importance among consumer.

Se evaluó el efecto de un gas oxidante sobre Salmonella enteritidis inoculada en la superficie del casacarón de huevo para plato. Se utilizó un gas de origen electrolítico, a una sola concentración y basado en su valor de potencial óxido-reductor superior a 950 mV. La exposición a este gas se llevó a cabo por tiempos de 1, 5 y 10 minutos. La carga inicial de S. enteritidis fue de 5.32 Log UFC/huevo. También se determinó el efecto de los tratamientos sobre la calidad externa e interna del huevo, esto es: resistencia mecánica y grosor del cascarón, índice de yema, pH y unidades Haugh. Todas las pruebas se realizaron a 4ºC y 30ºC, por intervalos de tiempo hasta el fin de su vida útil. El tratamiento con gas oxidante fue letal para S. enteritidis, de tal manera que esta bacteria no fue detectable desde el primer minuto de exposición al tratamiento. Los parámetos de calidad del huevo no se alteraron por efecto de los tratamientos. Se concluye que el gas oxidante es una alternativa viable y efectiva en el control sanitario del huevo para plato, particularmente en una de las bacterias más persistentes y de interés en este alimento.

Cilj ovog istraživanja bio je ispitati stabilnost ukupnih fenola i monomernih antocijana mutnih sokova od šipka tretiranih netoplinskim tehnikama te rezultate usporediti sa svježim i pasteriziranim sokovima tijekom 7 dana skladštenja na 4 °C. Sokovi od šipka tretirani su: (i) ultrazvukom uz variranje amplitude (75 i 100 %) i vremena tretiranja (2,5 i 5 min) te (ii) hladnom plazmom uz variranje frekvencije (60 i 90 Hz) i vremena tretiranja (2,5 i 5 min), kao i u kombinaciji svih ovih parametara prema punom faktorskom planu pokusa. Pasterizacija je provedena pri 90 °C/1 min. Ukupni fenoli i antocijani određeni su spektrofotometrijski. Za razliku od monomernih antocijana, pasterizacija nije značajno utjecala na stabilnost ukupnih fenola, dok su netermalne tehnike utjecale na značajno smanjenje udjela ukupnih fenola i monomernih antocijana u odnosu na pasterizirani i netretirani sok. Kombinirani tretman ultrazvuka i hladne plazme kao i tretman hladnom plazmom zasebno značajno je povoljn...

We discuss the electron heating in the course of magnetic reconnection by using both the Geotail observation and the particle-in-cell simulation. Geotail observes several unique non-Maxwellian velocity distribution functions during the plasma sheet crossing in association with a fast plasma flow. We find that the observed distributions can be classified into four different types depending on the position in the plasma sheet. In the boundary between the lobe and the plasma sheet, the distribution consists of the cold plasma flowing toward the X-type region and the hot plasma escaping from the X-type region along the magnetic field. In the plasma sheet side of the boundary, the distribution becomes bi-Maxwellian distribution with T > T ⊥. Inside the plasma sheet, the distribution is deformed into a hot and isotropic distribution. We discuss the physical mechanism responsible for those electron heating in a thin plasma sheet by using the kinetic reconnection simulation. We find that the dawn-dusk reconnection electric field as well as the turbulent waves excited by the strong Hall electric currents play an important role on the strong electron heating and acceleration.

Direct cold plasma treatment has been investigated as an alternative non-thermal technology as a means of maintaining and improving quality of fresh cloudy apple juice. Process variables studied included type of plasma discharge, input voltage and treatment time on polyphenol oxidase (PPO) inactivation. Spark discharge plasma at 10.5 kV for 5 min was the best treatment, with near total inactivation of PPO achieved, although good PPO inactivation was also recorded using shorter treatment times. Residual activity (RA) of PPO was 16 and 27.6% after 5 and 4 min of treatment respectively. This PPO inactivation was maintained throughout the storage trials, but decreased with samples treated for a shorter time. Plasma treatment improved key quality parameters of Golden delicious cloudy apple juice, with retention of critical quality parameters during extended storage trials. Color was the most noticeable change, which was enhanced with retention of a greener color. An increase of 69 and 64% was obtained in the total phenolic content after 4 and 5 min of treatment, respectively. Therefore, cold plasma was demonstrated to be a good alternative to traditional heat treatments for enhanced quality retention of fresh cloudy apple juice and over its storage.

The surfaces of two engineering polymers including polyamide 66 (PA66) and polytetrafluoroethylene (PTFE) were treated by diffuse coplanar surface barrier discharges in atmospheric air. We found that plasma treatment improved the adhesion of PA66 for either polymer/polymer or polymer/steel joints, however, it was selective for the investigated adhesive agents. For PTFE the adhesion was unaltered for plasma treatment regardless the type of used adhesive. Tribological properties were slightly improved for PA66, too. Both the friction coefficient and wear decreased. Significant changes, again, could not be detected for PTFE. The occurred variation in the adhesion and tribology was discussed on the basis of the occurred changes in surface chemistry, wettability and topography of the polymer surface.

In this paper, a construction microwave induced plasma jet(MIPJ) system was used to produce a non-thermal plasma jet at atmospheric pressure, at standard frequency of 2.45 GHz and microwave power of 800 W. The working gas Argon (Ar) was supplied to flow through the torch with adjustable flow rate using flow meter regulator. The influence of the MIPJ parameters such as applied voltage and argon gas flow rate on macroscopic microwave plasma parameters were studied. The macroscopic parameters results show increasing of microwave plasma jet length with increasing of applied voltage, argon gas flow rate where the plasma jet length exceed 12 cm as maximum value. While the increasing of argon gas flow rate will cause increasing into the argon gas temperature, where argon gas temperature the exceed 350 ? as maximum value and study the effect of gas flow rate on the optical properties

The present study is a hybrid method of studying the effect of plasma on the living tissue by using the image processing technique. This research explains the effect of microwave plasma on the DNA cell using the comet score application, texture analysis image processing and the effect of microwave plasma on the liver using texture analysis image processing. The study was applied on the mice cells. The exposure to the plasma is done by dividing the mice for four groups, each group includes four mice (control group, 20, 50, 90 second exposure to microwave plasma). The exposure to microwave plasma was done with voltage 175v and gas flow on 2 with room temperature; the statistical features are obtained from the comet score images and the textural features are calculated from the texture matrix energy measure. The result shows that the plasma has a clear effect on the DNA by reaper the damage cell and affecting the liver enzyme. The microwave plasma affected the ALP (Alkaline phosphatase...

A direct-current, atmospheric pressure, cold plasma microjet (PMJ) sustained in a quasi-steady gas cavity in liquid was used to inactivate Staphylococcus aureus suspended in distilled water. While helium gas (with 2% O 2 as additive) was used as working gas, an effective inactivation (>99%) was achieved in 6 min. The inactivation of bacteria was further verified by surface morphology examination and LIVE/ DEAD Baclight bacterial viability test (fluorescence microscopy). The overall pH and temperature of the liquid were monitored during the plasma treatment and were found to be below the critical values for the survival of S. aureus. Hydroxyl radical (OH) was detected via electron spin resonance (ESR) spectroscopy, and alongside other intermediate reactive species, is attributed to the effective inactivation of S. aureus. End-on optical emission spectroscopy show strong atomic oxygen emission both in air and in water.

Water quality, mineralization, and chemical composition, particularly pH and nitrogen compounds each, play a crucial role in plant development and growth. Treatment of water with non-equilibrium discharges results in the change of its properties and chemical composition, which in turn may affect plant growth process and subsequently agriculture produce quality. Both thermal and non-thermal discharges generated in air or in water produce a number of reactive neutral and charged species, electric fields, and ultraviolet radiation. Plasma treatment of water results in significant change of its properties like pH, oxidationereduction potential (ORP), conductivity, and concentration of reactive oxygen and reactive nitrogen species (ROS and RNS). Here we report the results of an experimental study of the effect of water treated with different atmospheric plasmas on germination, growth rates, and overall nutritional value of various plants. In the study we have used three types of plasmas: thermal spark discharge, gliding arc discharge, and transferred arc discharge. It is shown that the effects of these plasmas on chemical composition of various types of water are qualitatively different. Non-thermal gliding arc discharge plasma results in lower (acidic) pH, and production of significant amount of oxidizing species (e.g. H 2 O 2). Gliding arc discharge also causes significant acidification of water, but it is accompanied by production of reactive nitrogen species (NO, NO 2 À and NO 3 À). Spark discharge treatment results in neutral or higher (basic) pH depending on initial water composition, and production of RNS.

In the past two decades, worldwide interest in the natural dyes obtained from plants has rapidly increased, and a diversity of health and environmental benefits were found or argued for the practice. Cloves are the aromatic flower buds of a tree in the family Myrtaceae, Syzygium aromaticum, which their chemical compounds makes them suitable for the application in dyeing process. The important essential chemical constituents of clove include acetyl eugenol, beta-caryophyllene, vanillin, crategolic acid, gallotannic acid, and methyl salicylate. In this study, clove as the plant-derived dyestuff was used for dyeing the wool yarns to be investigated the effects of the different dyeing parameters including dyeing methods, acid and mordant type, and concentration and dyeing temperature in the yielded dyeing. The dyeing capability of the samples at different concentrations and temperatures was investigated using the spectrophotometer method and Beer–Lambert law. The results show that apply...

Many of the physical and functional properties of RDX and HMX explosives are related to the crystalline structure of these materials. Crystalline defects affect the quality of the explosives. Therefore, in order to enhance the quality of these materials, it is necessary to form crystals with the lowest defects. In this research, we report the optimization of recrystallization process of RDX and HMX by statistical techniques. The solvent/anti-solvent procedure was used for recrystallization of HMX and RDX particles. The four parameters of i) ratio of anti-solvent to solvent, ii) ratio of solute to solvent, iii) aging time, and iv) cooling rate of mixture, were optimized by Taguchi analysis design. Taguchi L16 orthogonal array was used with sixteen rows corresponding to the number of tests in four columns at four levels. The apparent density of recrystallized of RDX and HMX particles was considered as the quality characteristic with the concept of "the larger-the-better". The obtained graphs showed that the studied parameters were

Many of the physical and functional properties of RDX and HMX explosives are related to the crystalline structure of these materials. Crystalline defects affect the quality of the explosives. Therefore, in order to enhance the quality of these materials, it is necessary to form crystals with the lowest defects. In this research, we report the optimization of recrystallization process of RDX and HMX by statistical techniques. The solvent/anti-solvent procedure was used for recrystallization of HMX and RDX particles. The four parameters of i) ratio of anti-solvent to solvent, ii) ratio of solute to solvent, iii) aging time, and iv) cooling rate of mixture, were optimized by Taguchi analysis design. Taguchi L16 orthogonal array was used with sixteen rows corresponding to the number of tests in four columns at four levels. The apparent density of recrystallized of RDX and HMX particles was considered as the quality characteristic with the concept of "the larger-the-better". The obtained graphs showed that the studied parameters were

A simple technique is tested to improve the contractile effect of a cold plasma jet on acute wounds of mice. Distilled water on the order of microliters is dropped onto wounds before treatment. To assess the fate of the water, an infrared thermal imager is applied. To evaluate the healing effect, macroscopic and immunohistological studies are conducted. Regarding the wound contractile effect, we show that combination treatment of plasma with dropped water seemed to have a greater effect than plasma treatment alone. Plasma may modify the wound surface through such water, chemically and physically. The histological stiffness of the wound surface during maturation and remodeling, however, may also influence the fate of the water during treatment.

In the present study, common carp (Cyprinus carpio), a highly valuable worldwide commercial fish species, was used as a model. One sample group of fresh, skin-on carp fillets was placed in a bath of acidic electrolyzed oxidizing (AEO) water containing a solution of 100 mg/kg chloride ion concentration for 5 minutes. Another sample group was treated with acidic electrolyzed water and 0.5% lysozyme enzyme solution. Another set of samples were washed after the AEO water treatment. Within the study, a storage test was performed to examine the effect of the new combined treatment on the samples’ shelf-life and quality while kept at 2°C. During the storage period, chemical (chlorate) and microbiological (TVC, mesophilic anaerobic plate count, and Enterobacteriaceae count) tests and sensory evaluation were conducted. The combination of AEO water and lysozyme enzyme showed additional bactericidal efficacy on the surface of the carp fillets, which has never been reported before. Both the AEO...

A new prototype of plate Dielectric Barrier Discharge (DBD plate ) has been developed to treat liquid film falling by gravity. This approach is more pragmatic to extrapolate the technique at the pilot and industrial scale. Two modes of plasma process were adopted: (i) DBD plate alone and (ii) DBD plate coupled with TiO 2 (CDBD plate ). The addition of an optimized amount of TiO 2 to the dye solution increased the discoloration rate from 11% to 96% for 220 kJ L À1 of energy density. For the same energy density, without photo-catalyst, no mineralization has been noticed. However, in its presence, the concentration of Total Organic Carbon (TOC) has decreased by 80%. In this work, plasma process has been carried out in a single cycle of treatment to reduce the energy needed to generate the plasma. The addition of TiO 2 has intensified the DBD plate -plasma process.

Cold plasma treatment is a promising intervention in food processing to boost product safety and extend the shelf‐life. The activated chemical species of cold plasma can act rapidly against micro‐organisms at ambient temperatures without leaving any known chemical residues. This review presents an overview of the action of cold plasma against molds and mycotoxins, the underlying mechanisms, and applications for ensuring food safety and quality. The cold plasma species act on multiple sites of a fungal cell resulting in loss of function and structure, and ultimately cell death. Likewise, the species cause chemical breakdown of mycotoxins through various pathways resulting in degradation products that are known to be less toxic. We argue that the preliminary reports from cold plasma research point at good potential of plasma for shelf‐life extension and quality retention of foods. Some of the notable food sectors which could benefit from antimycotic and antimycotoxin efficacy of cold ...

In search for clues towards the understanding of the cold plasma sheet formation under northward IMF, we study the temperature anisotropy of the two-component protons in the plasma sheet near the dusk low-latitude boundary observed by the Geotail spacecraft. The two-component protons result from mixing of the cold component from the solar wind and the hot component of the magnetospheric origin, and may be the most eloquent evidence for the transport process across the magnetopause. The cold component occasionally has a strong anisotropy in the dusk flank, and the sense of the anisotropy depends on the observed locations: the parallel temperature is enhanced in the tail flank while the perpendicular temperature is enhanced on the dayside. The hot component is nearly isotropic in the tail while the perpendicular temperature is enhanced on the dayside. We discuss possible mechanism that can lead to the observed temperature anisotropies.

Cold plasma is a novel non-thermal technology that could be used for large scale leaf decontamination in food manufacturing as alternative to chlorine washing. The effect of atmospheric cold plasma apparatus on the safety, quality and antioxidant activity of radicchio (red chicory, Cichorium intybus L.) was investigated after treatment and during storage. Cold plasma treatment caused significant changes to the external appearance of the radicchio leaves during storage as assessed by a sensory and image analysis. Chroma values of radicchio leaves were also affected by the cold plasma treatments. The antioxidant activity of radicchio leaves, assessed by the ABTS and ORAC assays, was not affected by cold plasma treatments (15 and 30 min). E. coli inoculated on radicchio leaves was significantly reduced after 15 min cold plasma treatment. However, a 30 min plasma treatment was necessary to achieve a significant reduction of L. monocytogenes counts. Atmospheric cold plasma appears to be a promising technology for the decontamination of leafy vegetables when applied under the optimised conditions.

Superoxide is one of the reactive oxygen species (ROS) in non-thermal plasmas generated by electrical discharges in air at room temperature and atmospheric pressure. One important application of such plasmas is the activation of advanced oxidation processes for air and water decontaminating treatments. When in contact with aqueous media, ROS and notably superoxide can react at the plasma/liquid interface or transfer and react into the liquid. While the detection of superoxide in plasma-treated water has been reported in the literature, to the best of our knowledge, quantitative determinations are lacking. We report here the determination of superoxide rate of formation and steady-state concentration in water subjected to air non-thermal plasma in a streamer discharge reactor used previously to treat various organic contaminants. After detecting the presence of superoxide by spin-trapping and electron paramagnetic resonance analyses, we applied superoxide-selective fluorescent probes to carry out quantitative determinations. The first probe tested, 3′,6′-bis(diphenylphosphinyl) fluorescein (PF-1), was not sufficiently soluble, but the second one, fluorescein-bis-[(N-methylpyridinium-3-yl)sulfonate iodide] (FMSI), was applied successfully. Under typical plasma operating conditions, the rate of superoxide formation and its steady-state concentration were (0.27 ± 0.15) μM s −1 and (0.007 ± 0.004) nM, respectively. The procedure outlined here can be usefully applied to detect and quantify superoxide in water treated by different plasma sources in various types of plasma reactors.

Superoxide is one of the reactive oxygen species (ROS) in non-thermal plasmas generated by electrical discharges in air at room temperature and atmospheric pressure. One important application of such plasmas is the activation of advanced oxidation processes for air and water decontaminating treatments. When in contact with aqueous media, ROS and notably superoxide can react at the plasma/liquid interface or transfer and react into the liquid. While the detection of superoxide in plasma-treated water has been reported in the literature, to the best of our knowledge, quantitative determinations are lacking. We report here the determination of superoxide rate of formation and steady-state concentration in water subjected to air non-thermal plasma in a streamer discharge reactor used previously to treat various organic contaminants. After detecting the presence of superoxide by spin-trapping and electron paramagnetic resonance analyses, we applied superoxide-selective fluorescent probes to carry out quantitative determinations. The first probe tested, 3′,6′-bis(diphenylphosphinyl) fluorescein (PF-1), was not sufficiently soluble, but the second one, fluorescein-bis-[(N-methylpyridinium-3-yl)sulfonate iodide] (FMSI), was applied successfully. Under typical plasma operating conditions, the rate of superoxide formation and its steady-state concentration were (0.27 ± 0.15) μM s −1 and (0.007 ± 0.004) nM, respectively. The procedure outlined here can be usefully applied to detect and quantify superoxide in water treated by different plasma sources in various types of plasma reactors.

Low energy electron beam (e-beam) has the ability to decontaminate or reduce bioburden and enhance the food product's safety with minimal quality loss. The current study aimed to evaluate the efficacy of e-beam on natural microbiota and quality changes in black peppercorns. The black pepper was exposed to e-beam at doses from 6-18 kGy. The microbial quality, physicochemical attributes, total phenolic compounds, and antioxidant activity were evaluated. Results demonstrated the microbial population in black pepper decreased with increasing e-beam treatment doses. Significant inactivation of Total Plate Count (TPC), yeasts, and molds were observed at dose 6 kGy by 2.3, 0.7, and 1.3 log CFU g −1 , respectively, while at 18 kGy the reduction level was 6, 2.9, and 4.4 log CFU g −1 , respectively. Similarly, 18 kGy of e-beam yielded a reduction of 3.3 and 3.1 log CFU g −1 of Salmonella Typhimurium and coliform bacteria, respectively. A significant difference (p < 0.05) was noted between doses 12, 15, and 18 kGy on Bacillus cereus and Clostridium perfringens in black pepper. During e-beam doses, the values L ⁎ , a ⁎ and b ⁎ of black peppercorn were not noticeably altered up to 18 kGy dose. No significant (p > 0.05) difference in moisture, volatile oil, and piperine content upon (6-18 kGy) treatments in comparison to the control. A slight difference in the 738 AIMS Agriculture and Food Volume 7, Issue 3, 737-749. bioactive compound, retaining >90% of total phenolic compounds and antioxidant activity. Results revealed that e-beam doses ≥ 18 kGy were influential for inactivating natural microbes and foodborne pathogens without compromising the physicochemical properties and antioxidant activity of black peppercorns.

As woods are dwindling and agriculture waste burning causes severe air pollution and releases greenhouse gases, the processing of Hemp and lignocellulosic surplus materials into chipboards and other construction elements, may substitute timber and reduce environmental pollution. The presented environmental-friendly technology has the potential of processing hemp and recycling residual materials into industrial woodchip boards and structural elements and without the use of hazardous expensive resins. By applying cold plasma pre-treatment followed by the pressing stage acceptable wood chip standard physical properties are achieved. The irradiation dosage is probably optimal since once exceeding the dosage applied, wood disintegration starts; the process improvement may be related to the pressing configuration. Since the pressing temperature and duration are probably higher than required, the element that may still be aligned is the pressing pressure. Moreover, the positive correlation between sample strength and pressing pressure did not reach a steady state value even when pressing the sample to the maximum possible pressure allowed in the existing equipment (5.5 tons). It is suggested that by increasing the pressing pressure and decreasing the pressing temperature a significant strength improvement will be attained. It is assumed that 20 tons/m2 pressing pressure will be sufficient to attain the desired properties.

Nowadays, the food industry, according to the needs of the growing population in the world, must align itself with the existing nutritional standards on the one hand and the increasing expectations of consumers on the other hand. Of course, the limitation of available resources and monitoring requirements during the process should be added to these items. For this reason, in order to overcome the upcoming challenges, the need for new technologies has been felt. The application of cold plasma in food and agriculture industries is one of these cases, which in this article tried to examine the different aspects of their use. It is worth mentioning that the use of cold plasma in the food industry is a new technology and extensive research is still being done in this regard.