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In this study, low pressure non-thermal radiofrequency nitrogen plasma at very low power has been used to treat the artichoke seeds on the powered cathode for the first time. The influence of treatment time on the surface physical properties, germination rate, seedling growth, and enzyme activity of the seeds has been investigated. Results showed t...
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... wetting properties of the treated seeds were exam- ined by apparent contact angle measurements. The results showed that the water contact angle of the nitrogen plasma treated seeds substantially decreased, while that of the 15 min plasma treated seeds reduced to zero (Fig. 4). Generally, the chemical structure and physical properties of the seed surface govern its surface energy and contact angle. Physically, the presence of cracks and fractures on the seed husk increases the surface roughness. Moreover, it causes more leakage of water through the seed coat which decreases the water contact angle. From chemical point of view, the decrease in contact angle may be due to the surface functionalization by hydro- philic groups during plasma treatment. As can be seen from Fig. 2, the main species in the OES spectrum are N 2 þ and excited N 2 molecules. The ions are accelerated toward the cathode, due to produced negative RF self-bias, and break the surface bonding of the seed coat which creates many dangling bonds on the seed surface. This followed by the interaction of excited N 2 and residual oxygen molecules in the chamber (or in the ambient air after treatment) with the produced dangling bonds leads to generate amine, amide, and other polar groups on the surface (Fatyeyeva et al., 2014 andda Silva et al., 2017). Additionally, Shapira et al. (2017) reported that plasma treatment charges the organic surfaces that induce dipole- monopole interaction with polar water molecule which increases surface ...
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... optical emission spectrum of nitrogen plasma is shown in Fig. 2. OES is one of the fast, real time, and nonde- structive techniques for studying the produced radicals, active species, atoms, and ions in plasma. The main identified spe- cies in plasma are the N 2 second positive system from C 3 II u state to B 3 II g state N 2 (337 nm, 370.10 nm) and first negative system N 2 þ (358.21 nm, 391.40 nm, and 427.81 nm) ( Ji et al., 2015 andQayyum et al., 2005). There are two additional lines at (777 nm, 844 nm) which are related to the electron transition of oxygen atoms O * from 3p 5 P to 3s 5 S and from 3p 3 P to 3s 3 S, respectively ( Wan et al., 2017 andChau andKao, 1996). The low intensity of these two lines with respect to that of nitrogen species indicates that small amounts of oxygen atoms are remained in the chamber. Our results show that the artichoke seeds interact mainly with nitrogen excited species along with a few oxygen excited atoms. They are also bombarded by N 2 þ ions during the plasma treatment. Figure 3 shows the SEM images of surface modifica- tions of three sets of artichoke seeds: non-treated (control), vacuum treated, and nitrogen plasma treated seeds. As it can be seen in Figs. 3(a) and 3(b), the control and vacuum treated seeds' surface comprises similar rectangular type domains 25, 013525 (2018) with the little randomly distributed granules which are sup- posed to be built from proteins ( Sotomayor et al., 1999). The seed surface of control and vacuum treated samples have an ideal shape, without any defects, fractures, and ...
Citations
... Wavelengths of 388 and 436 nm correspond to CH radicals [27,28] and atomic oxygen, and the line at 559.1 nm, merging with the carbon line, belongs to molecular oxygen O2 [30]. In addition, the graph presents a nitrogen peak with a wavelength of 358.21 nm [31], which confirms the diffusion of air from the surrounding atmosphere into the reaction chamber through leaky seals. ...
We present the preliminary results of experimental studies on hydrogen production through methane pyrolysis. Based on the analytical review, the technology of methane pyrolysis in the plasma of a microwave discharge was chosen. To implement this method, an installation for applied research PM-6 was developed, and experimental data on the possibility of producing hydrogen was obtained. The methods of mass spectrometry and optical emission spectrometry were used to analyze the products of the methane decomposition reaction. It has been established that at a microwave forward power of 0.6 kW, plasma pyrolysis of methane occurs with the formation of hydrogen, carbon, and hydrocarbons. Preliminary calculations of methane conversion, as a result of the conducted studies, showed a hydrogen selectivity of 4–5%. The developed installation and the applied method are under modernization at the present time.
... The dominant Ar and oxygen species most likely etched the seed coats; nitrogen species were likely to arise during air discharge at the plasma jet tip. These results corresponded with similar studies from active ion species etching artichoke seeds, that result in enhanced germination [20]. These surface chemical modifications, to be discussed in the FTIR section, on the surfaces of our chilli seeds facilitated water absorption, which aided the seed germination. ...
In the current study, a square assembly of four quad-atmospheric pressure plasma jets (q-APPJ) is used to treat large-sized chilli seeds simultaneously. Germination and growth characteristics improve significantly after a 10-sec treatment of q-APPJ employing argon as the working gas. Plasma-treated chilli seed is more etched and porous than those untreated seed surface, as shown in scanning electron microscopy. The chemical changes of the plasma-treated seeds showed that the Ar plasma-treatment oxidise the seed surface to enhance their wettability, stimulate the water uptake, increase the water electrical conductivity and result in improved seed germination. In addition, optical emission spectroscopy is used to detect the different plasma species present and evaluate their plasma parameters (electron temperature and density). These positive results suggested that Ar plasma-treatment, in APPJ setup, improve seed germination, and potentially improve crop yield, and food security issues.
... These are effective elicitors that can promote seed germination, plant growth development, and metabolism. Plasma treatment has been recognized as a promising and effective technology for enhancing the germination of various plant species [9][10][11][12][13][14][15][16][17][18][19]. However, the effect of plasma treatment on kangkong seed germination has not been reported. ...
... For example, the presence of cracks in the barley seed surface widened after being exposed to DBD plasma at 40-80 W for 15 s [41]. The artichoke seed surface showed small holes and cracks; the changes were more serious when DBD plasma treatments were longer, from 3 min to 10 and 15 min [17]. The etching effect on the spinach seed surface under 5 min of DBD plasma treatment was reported [15]. ...
... This occurred due to the increased roughness and widening cracks on the kangkong seed surface after longer DBD plasma treatments, which improved wettability. These results are consistent with those reported by Hosseini et al. [17], who observed similar changes in artichoke seed surfaces following plasma treatment, resulting in a decreased water contact angle and improved wetting properties. In contrast, no structural changes in the seed surface were observed in mimosa [19], pepper, and cucumber seeds [12]. ...
Dielectric barrier discharge (DBD) plasma has been utilized as a sustainable technology to enhance seed germination in various plant species. The objective of this research was to identify the mechanism of physicochemical properties and antioxidant enzyme activities to promote kangkong (Ipomoea aquatica Forssk.) seed germination using different durations of DBD plasma treatments. Seeds were exposed to atmospheric DBD plasma from 5 to 20 min, compared to non-treated seeds as the control. According to SEM images, the seed surface had cracks and grew wider as a result of the prolonged DBD plasma treatments. A longer DBD plasma treatment exhibited a lower water contact angle and increased water absorption. DBD plasma treatments strongly improved germination percentages and hydrogen peroxide (H2O2) contents. Seeds treated with DBD plasma for 20 min showed the highest malondialdehyde (MDA) content and the lowest field emergence. Catalase (CAT) activity increased under DBD plasma treatments for 5 and 10 min. Ascorbate peroxidase (APX) and superoxide dismutase (SOD) activities were not statistically different among the treatments. This finding suggested that DBD plasma treatments stimulated the germination of kangkong seeds by modifying the seed surface, and upregulating H2O2 content and CAT activity. Five minutes was an appropriate time to treat DBD plasma.
... Various techniques, such as different fer lizers, pes cides, water treatment, heat disinfec on, etc., are being applied to increase crop yields 1-4 . However, these methods also have a certain number of problems which include adverse impacts on health crops, eventuate pollu on a er the treatments and adding toxicity to produce various disease challenges for animals and humans as well as economic impossibility etc. 2,[5][6][7] As we strive towards finding new ways of promo ng sustainable and economically viable solu ons for enhancing seed germina on and plant growth, one op on we are currently exploring is plasma ac vated water (PAW). PAW is created by transferring various reac ve oxygen-nitrogen species (RONS) from the plasma phase to water. ...
As a threat to meeting the global demand for food created by the continued growth of the population, different methods are being applied to enhance seed germination and plant growth. This study investigates the effect of hydrogen-riched water (HRW), plasma-activated water (PAW) and their combination on the seed germination of lentils. For activating water, arc discharge reactors are generated under atmospheric pressure in the air. Simulations were also performed to simulate electric field and potential, fluid flow, and arc plasma. Using optical emission spectroscopy, species were evaluated in plasma columns. Raman spectra and physicochemical properties of water were investigated. On day 3 after treatment, the fraction and length of germinated seeds were evaluated. During germination, treated water significantly increased germination parameters such as final germination percentage, mean germination time, germination index, coefficient of germination velocity, and germination rate index. It can, therefore, be concluded that seed germination can be increased using PAW and hydrogenated PAW combined.
... Various techniques, such as different fertilizers, pesticides, water treatment, heat disinfection, etc., are being applied to increase crop yields [1][2][3][4]. However, these methods also have a certain number of problems, which include adverse impacts on health crops, eventuate pollution after the treatments and adding toxicity to produce various disease challenges for animals and humans as well as economic impossibility, etc. [2,[5][6][7] As we strive towards finding new ways of promoting sustainable and economically viable solutions for enhancing seed germination and plant growth, one option we are currently exploring is plasma-activated water (PAW). PAW is created by transferring various reactive oxygen-nitrogen species (RONS) from the plasma phase to water [8]. ...
As a threat to meeting the global demand for food created by the continued growth of the population, different methods are being applied to enhance seed germination and plant growth. This study investigates the effect of hydrogen-riched water (HRW), plasma-activated water (PAW) and their combination on the seed germination of lentils. For activating water, arc discharge reactors are generated under atmospheric pressure in the air. Simulations were also performed to simulate electric field and potential, fluid flow, and arc plasma. Using optical emission spectroscopy, species were evaluated in plasma columns. Raman spectra and physicochemical properties of water were investigated. On day 3 after treatment, the fraction and length of germinated seeds were evaluated. During germination, treated water significantly increased germination parameters such as final germination percentage, mean germination time, germination index, coefficient of germination velocity, and germination rate index. It can, therefore, be concluded that seed germination can be increased using PAW and hydrogenated PAW combined.
... The plasma treatment apparatus was a capacitive coupled Radiofrequency (RF) plasma system. The system consists of a stainless-steel chamber with a diameter of 30 cm and length of 35 cm and a 10 cm water-cooled power electrode which was described in detail previously (22). ...
... For each experiment, a control was prepared without plasma treatment and kept at room temperature until the next step. The schematic of the system was shown in Hosseini et al. (22). All experiments were done in triplicate. ...
Background and Objectives: Plasma radiation is a widely used technique for sterilization or decontamination in various industries, as well as in some healthcare settings such as dentistry. The primary aim of this study was to assess the potential of plasma radiation to create a new population of Staphylococcus aureus cells with distinct characteristics that could lead to novel healthcare challenges.
Materials and Methods: A homemade non-thermal plasma apparatus was applied and the effects of plasma treatment on S. aureus ATCC25923 was assessed. Plasma radiation was applied under controlled conditions to ensure that some bacterial cells remained viable. The treatment was repeated 10 times, with each round followed by a recovery phase to collect any surviving bacterial cells. To assess the potential changes in the bacterial population, we examined the antibiotic susceptibility pattern, micro-structural characteristics using scanning electron microscopy (SEM), and total protein profile using the matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) technique.
Results: The experimental results revealed slight variations in the antibiotic susceptibility patterns of certain cell wall agents (imipenem, cephalothin, and cefepime), as well as in the MALDI-TOF spectra. However, no changes were observed in the SEM images.
Conclusion: The insufficient application of non-thermal plasma in bacterial decontamination may lead to physiological changes that could enrich or select certain subpopulations of S. aureus.
... The emission from N 2 first negative system (FNS) was seen around 400 nm, which corresponds to the transition N + [44,45]. Additionally, strong emission from N 2 first positive system (FPS), corresponding to the transition N + 2 (B 3 ∏ g −A 3 ∑ u ) in the range of 478 nm to 900 nm [46][47][48][49], is mostly observed in pyramid μ-electrode DBD, making it different from the flat electrode DBD. Atomic nitrogen typically does not manifest in the OES spectrum of conventional DBD plasma. ...
Plasma-assisted nitrogen fixation has emerged as a promising alternative to conventional nitrogen fixation methods. In this study, we investigate the feasibility of plasma-assisted nitrogen fixation using an AC-driven dielectric barrier discharge generated from the micro-tips of a specially designed fast-modulated pyramid-shaped electrode. The obtained result is compared with the conventional flat electrode. Our results demonstrate that pyramid-shaped micro-tip electrodes can excite more nitrogen molecules than flat electrodes. Thus, pyramid electrodes have 58% more nitrogen oxides yield efficiency at 32% less energy cost. The highest nitrogen fixation is attained at 60% to 70% of oxygen concentration in nitrogen-feeding gas. These findings suggest that discharge through microtip is a promising and viable technology that could play a significant role in reducing the energy cost of the plasma-assisted nitrogen fixation method to meet the growing demand for sustainable nitrogen-based fertilizers.
... The N2 Second Positive System (SPS) has a main peak at a wavelength of 313 -390 nm, the N2 first negative system (FNS) at a wavelength of 390 -450 nm [23,24]. At the same time, a small peak of OH appears at a wavelength of 296.1 nm [21,25,26]. OH is generated from the dissociative excitation process of water particles [20]. ...
The ability of Escherichia coli to become increasingly resistant to sterilization has resulted in high cases of this bacterial infection. To overcome this problem, a new method is needed. The circuit design uses 2 parallel plates of copper material. The first plate is HV electrode and second plate is ground electrode which is separated by a dielectric layer. Non-thermal plasma with surface dielectric barrier discharge is generated using a 20 VDC voltage source and then transformed into a high voltage source to generate plasma. Distance between plasma source and fixed sample is 3 mm. OES is used to observe reactive species produced in plasma indicated by magnitude of intensity at certain wavelengths. SDBD non-thermal plasma could be used to inactivate bacteria depending on treatment time. The longer treatment time, greater inactivation ability. For the number of colonies after being treated for 120 s, namely 4.33×107 CFU/mL, it was much lower than control, which was 409×107 CFU/ml. For DNA after being treated for 120 s, results of genome from Escherichia coli were no longer visible or faded, marked by a DNA concentration of 8.18 ng/ul, far lower than the control DNA concentration of 124.44 ng/ul. For the activity of the protease enzyme, the time variation of 105 s had the smallest activity value of the protease enzyme, namely 35.375 U/mL compared to control, which was 52.307 U/mL whereas for cell morphology after 120 s treatment showed increasingly severe cell damage observed using SEM. Non-thermal plasma SDBD configurations can be used to inactivate or kill bacteria. Effectiveness or capability of non-thermal plasma also depends on the treatment time. SDBD nonthermal plasma ability increases with the longer treatment time. HIGHLIGHTS In this research, a non-thermal plasma method of surface dielectric barrier discharge (SDBD) for Escherichia coli sterilization was developed. The results of research on inactivation of Escherichia coli bacteria using non-thermal plasma SDBD showed that the configuration of non-thermal plasma SDBD could be used to inactivate or kill bacteria. The effectiveness or capability of non-thermal plasma also depends on the treatment time. SDBD non-thermal plasma capability increases with longer treatment time. GRAPHICAL ABSTRACT
... In the UV region, the emission spectrum shows that N 2 and N 2 + excitation species' emission shows di erent peaks. A small peaks of OH appear at wavelengths 296,1 nm (Adhikari et al., 2021;Dhungana et al., 2020;Hosseini et al., 2018;Naz et al., 2021;Sarangapani et al., 2016). The low intensity of singlet oxygen is at a wavelength of 777.5 nm (Sarangapani et al., 2016) . ...
Research on the inactivation of Escherichia coli causing diarrheal disease using non-thermal plasma SDBD has been carried out. SDBD is a new technique for non-thermal plasma generation with several advantages: low power generation, comprehensive treatment area coverage, and reducing the potential effects of burning and drying tissue. This study aimed to analyze the effect of treatment time variations, namely 0 as control, 60, 75, 90, 105, and 120 seconds and treatment distance variations of 3, 6, 9, 12, and 15 mm of non-thermal plasma treatment of SDBD on E. coli. The results of the non-thermal plasma SDBD treatment with variations in time and distance showed that the longer the treatment time, the more bacterial cells died. Colony counts decreased to 4.33 x 107 CFU/mL compared to the control, 409 x 107 CFU/mL, with a treatment time variation of 120 seconds, yielding the best treatment results. At the same time, the results of the treatment for variations in the non-thermal plasma distance of SDBD showed that the smaller the treatment distance, the greater the bacterial death rate, with the best treatment results at a 3 mm treatment interval, with colony counts of 8 x 107 CFU/mL, compared to 409 x 107 CFU/mL in control. Based on these results, SDBD non-thermal plasma treatment can be used to inactivate or kill bacteria with effectiveness in killing bacteria depending on the length of treatment time and the distance of treatment.
... Similarly, the excited nitrogen species originate from dissociating nitrogen molecules in the surrounding environment or gas source. (Adhikari et al., 2021;Hosseini et al., 2018;Kaushik et al., 2022;Misra et al., 2015;Naz et al., 2021;Pourbagher et al., 2021;Rezaei et al., 2014;Wang et al., 2017;Zhou et al., 2015). ...
Non-thermal plasma is one of the new techniques that is being focused on in the medical world, one of which is used for sterilization because non-thermal plasma is known to have a bactericidal effect. Reactive species produced by non-thermal plasma are antimicrobial. One factor affecting plasma species' reactive composition is the gas source used. Therefore, this study aimed to determine the effect of reactive species produced from non-thermal plasma generation of SDBD using different gas sources, namely free air, oxygen, and nitrogen, in treating Escherichia Coli bacteria. The gas flow used is 1 liter/minute. Reactive species produced by plasma were characterized using Optical Emission Spectrometry (OES). SDBD Non-thermal plasma treatment for Escherichia Coli bacteria samples was repeated three times for each treatment, and then the Anova test was performed. The results of this study indicate that bacterial death at the decontamination level depends on the composition of the gas used during treatment. Plasma using an O2 gas source has a more effective inactivation ability, namely 6 x 107 CFU/ml, compared to the control, which is 409 x 107 CFU/ml. At the same time, the treatment results with free air and nitrogen gas sources were 6.33 x 107 CFU/ml and 41.67 x 107 CFU/ml. These results indicate that the composition of ROS and RNS influences bacterial inactivation, where ROS is more effective in inactivating bacteria than RNS
