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The present work is focused on investigating the effect of plasma-activated water (PAW) on the seed germination and seedling growth of radish, fenugreek, and pea seeds. A home-made gliding arc discharge (GAD) reactor generated in air under atmospheric pressure and operating at 50 Hz line frequency is used for water activation. PAW was prepared by exposing deionized water to GAD for 5, 10, 15, and 20 min. As a result of plasma treatment, deionized water showed substantial changes in physical characteristics such as pH and electrical conductivity along with chemical parameters such as nitrites, nitrates, and ammonia. The effect on germination was evaluated based on the fraction of germinated seeds and their length at 7 and 12 days after treatment. Seeds irrigated with PAW resulted in a higher imbibition rate than those irrigated by deionized water. When the seeds were irrigated with PAW, the germination parameters such as final germination rate, mean germination rate, coefficient of velocity of germination, germination index, and growth parameters such as shoot/seedling length and vigor index increased. In conclusion, PAW may be utilized to increase the germination rate of seeds. [ABSTRACT FROM AUTHOR]

Plasma–liquid interaction is a critical area of plasma science, mainly because much remains unknown about the physicochemical processes occurring at the plasma–liquid interface. Besides a lot of experimental studies toward the interaction, a few fluid models have also been reported in recent years. However, the interfacial boundary conditions in the models are different and the Henry's law constants therein are uncertain; hence, the accuracy and robustness of the simulation results are doubtable. In view of this, three 1D fluid models are developed for the interaction between a plasma jet and deionized water, each of which has a unique interfacial boundary condition as reported in the literature. It is found that the density distribution of reactive species is nearly independent of the interfacial boundary conditions in both the gas and liquid phases, except for that in the interfacial gas layer with a thickness of several tens of micrometers above water. The densities of the reactive species with high Henry's law constants (H > 104) are much different in such gas layers among the interfacial boundary conditions. Moreover, some Henry's law constants are changed in the models according to their uncertainty reported in the literature, and only the reactive species with low Henry's law constants (H < 1) have their aqueous densities following the change. These densities are very low in the plasma-activated water. It could be concluded that the simulation of plasma–liquid interaction is generally independent of the interfacial boundary conditions and the uncertainty in Henry's law constants. [ABSTRACT FROM AUTHOR]

To study the process by which an explosive high-speed airflow extinguishes an arc and the characteristics of arc dielectric recovery in a semienclosed space, this study investigates the principles and processes of the formation, development, and extinction of an arc under the action of a high-speed airflow. When the impact arc occurs in a semienclosed arc-extinguishing chamber, the high-speed air suppresses arc development. Due to the high-speed airflow, the arc cools at an accelerated rate; the arc energy weakens, breakpoints occur, and the continuity of the arc energy channel is broken, preventing the arc from forming in the arc-extinguishing chamber and extinguishing it. This article employs AUTODYN software to establish a model for high-speed airflow arc extinguishing in a semienclosed space and then reveals a process by which a high-speed airflow extinguishes an arc in such a space. To verify whether a high-speed airflow can extinguish an arc, we conduct experiments in which high-speed airflow extinguishes a large impact arc and a power frequency arc. We recorded the arc extinguishing process with high-speed and ordinary cameras. The time taken to extinguish the arc is approximately 7 ms, and the arc does not regenerate. [ABSTRACT FROM AUTHOR]

Fabrication of microlenses on a diamond surface is an important way to enhance the performance of the embedded nitrogen vacancy (NV) center which is a promising single light source for quantum communication and quantum-based detection. In this work, lenses with a micrometer diameter were fabricated on a diamond surface by using the inductively coupled plasma (ICP) etching technique with a mask of polystyrene (PS) balls. First, 1 µm diameter PS balls were dispersed on the surface of deionized water. Then, the balls were transferred onto a diamond surface. Third, the sample was treated using the ICP technique to form microlenses. By increasing ICP etching time, the surface of fabricated microlenses became smoother. The simulation results demonstrate that the microlenses can greatly improve the photon collection efficiency of the embedded NV center and focus more excitation light to the NV center than bulk diamond. [ABSTRACT FROM AUTHOR]

Treatments designed to intervene in conventional direct-drug-to-cell-binding communication have been hallmark approaches in designing new drug candidates. Given the random collision of molecules in living systems, this binding is laborious and too ineffective to precisely match the binding site. Therefore, it has been proposed that another non-chemical and non-electrical drug-cell communication channel, termed "bindingless" or "wired", could exist to impact signal transduction. Here we present the use of a micro-barrier well-array device to explore the unidentified bindingless anti-cancer mechanism. The device involves a 95-μm polydimethylsiloxane barrier to compartmentalize cancer cells and chemotherapeutic drugs. The lack of permeation of solutions across the device barrier was validated. Paclitaxel diluted in medium significantly inhibited the growth of prostate PC-3 cancer cells over a 95-μm barrier instead of cisplatin. The inhibition was attenuated by diluting drugs in other solvents, such as deionized water and phosphate-buffered saline. In addition, the orientation of magnetic field could partially dominate the "wired" communication. The collective data provide the experimental evidence of the postulated "wired" drug-cell communication as a potent in anti-cancer mechanism. These findings may inform cell biology investigations and stimulate studies of new physical and chemical phenomena. [ABSTRACT FROM AUTHOR]

Stability of cobalt-doped lanthanum iron silicide, La(FexCoySi1-x-y)13 have been investigated under conditions required for magnetocaloric refrigeration. The XRD analysis revealed that both milled and non-milled samples stored in water loose a few Bragg peaks corresponding to the NaZn13 phase of La(FexCoySi1-x-y)13. Samples stored in air show well-defined Bragg peaks similar to that of pristine material. The SEM-EDS of the milled and non-milled samples stored in water and air show an increased concentration of oxygen in the samples, particularly those treated with water. The course non-milled powders stored in air and water show sharp transitions at the Curie temperature TC = 300K without large magnetization above the TC. The milled, fine-particulate sample stored in air shows a slightly broadened transition at TC, and that stored in deionized water for 14 days shows significantly broadened transition from 300K and retains large magnetizations above 400 K. This is indicative of relatively fast hydrolysis and removal of some or all of La, likely as hydroxide, from fine powders, leaving behind La-poor or, potentially, La-free Fe-Co-Si containing ferromagnetic residue with much higher Curie temperature. The non-milled course sample stored in water has sharper magnetic transition and higher magnetization hence it shows the highest entropy change among all 4 type of samples. [ABSTRACT FROM AUTHOR]