• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.6
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• pp.797-801
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• 2014

This research presented the concept of employing the punch-through diode triggered SCRs (PTTSCR) for low voltage ESD applications such as transient voltage suppression (TVS) devices. In order to demonstrate the better electrical properties, various traditional ESD protection devices, including a silicon controlled rectifier (SCR) and Zener diode, were simulated and analyzed by using the TCAD simulation software. The simulation result demonstrates that the novel PTTSCR device has better performance in responding to ESD properties, including DC dynamic resistance and capacitance, compared to SCR and Zener diode. Furthermore, the proposed PTTSCR device has a low reverse leakage current that is below $10^{-12}$ A, a low capacitance of $0.07fF/mm^2$, and low triggering voltage of 8.5 V at $5.6{\times}10^{-5}$ A. The typical properties couple with the holding voltage of 4.8 V, while the novel PTTSCR device is compatible for protecting the low voltage, high speed ESD protection applications. It proves to be good candidates as ultra-low capacitance TVS devices.

• Journal of Sensor Science and Technology
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• v.29 no.6
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• pp.365-368
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• 2020

As a green and abundant source of energy, H2 has attracted the attention of researchers for use in different applications. Nevertheless, it is highly flammable, and because of its significantly small size, extreme attention is needed to detect its leakage. In this review, we discuss different effects of noble metals on the H2 gas response and performance of metal oxide-based gas sensors. In this regard, we discuss the effects of noble metals, in combination with metal oxides, on H2 gas detection. The catalytic activity towards H2 gas and the formation of heterojunctions with metal oxides are the main contributions of noble metals to the sensing improvement of H2 gas sensors. Furthermore, in the special case of Pd and somewhat Pt, the formation of PdHx and PtHx also affects the H2 sensing performance. This review paper provides useful information for researchers working in the field of H2 gas detection.

• Biomolecules & Therapeutics
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• v.28 no.1
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• pp.25-33
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• 2020

Several recent studies have reported that reactive oxygen species (ROS), superoxide anion and hydrogen peroxide (H₂O₂), play important roles in various cellular signaling networks. NADPH oxidase (Nox) isozymes have been shown to mediate receptor-mediated ROS generation for physiological signaling processes involved in cell growth, differentiation, apoptosis, and fibrosis. Detectable intracellular levels of ROS can be induced by the electron leakage from mitochondrial respiratory chain as well as by activation of cytochrome p450, glucose oxidase and xanthine oxidase, leading to oxidative stress. The up-regulation and the hyper-activation of NADPH oxidases (Nox) also likely contribute to oxidative stress in pathophysiologic stages. Elevation of the renal ROS level through hyperglycemia-mediated Nox activation results in the oxidative stress which induces a damage to kidney tissues, causing to diabetic nephropathy (DN). Nox inhibitors are currently being developed as the therapeutics of DN. In this review, we summarize Nox-mediated ROS generation and development of Nox inhibitors for therapeutics of DN treatment.

• Horticultural Science & Technology
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• v.34 no.3
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• pp.383-395
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• 2016

This study investigated the effect of exogenous hydrogen peroxide ($H_2O_2$) on the antioxidant responses and growth of warm-season turfgrass (Zoysia japonica Steud.) and cool-season turfgrass (Poa pratensis L.) subjected to drought stress. Compared with control plants that were not pretreated with $H_2O_2$, plants pretreated with $H_2O_2$ had significantly greater fresh and dry weights of shoots and roots, and increased water content. $H_2O_2$ pretreatments before drought stress significantly decreased the concentrations of malondialdehyde and $H_2O_2$. DPPH radical scavenging and glutathione activities were significantly increased. The responsive activities of the antioxidant enzymes superoxide dismutase, ascorbate peroxidase, catalase, and peroxidase were also significantly enhanced. Our results suggest that exogenous $H_2O_2$ could improve the growth of warm-season and cool-season turfgrass under drought stress by increasing the activity of their antioxidant enzymes, while decreasing lipid peroxidation.

• Journal of the Semiconductor & Display Technology
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• v.18 no.2
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• pp.98-102
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• 2019

Direct plasma-enhanced atomic layer deposition (PEALD) are widely used for $SiO_2$ and SiON thin film process in current semiconductor industry. However, this exhibits poor step coverage for three-dimensional device structure due directionality of plasma species as well as plasma damage on the substrate. In this study, to overcome this issue, low temperature (< $300^{\circ}C$) $SiO_2$ and SiON thin film processes were studied using inductively coupled plasma (ICP) type remote PEALD with various reactant gases such as $O_2$, $H_2O$, $N_2$ and $NH_3$. It was confirmed that the interfacial properties such as fixed charge density and charge trapping behavior of thin films were considerably improved by hydrogen species in $H_2O$ and $NH_3$ plasma compared to the films grown with $O_2$ and $N_2$ plasma. Furthermore, the leakage current density of the thin films was suppressed for same reason.

• Journal of Convergence for Information Technology
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• v.9 no.5
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• pp.21-26
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• 2019

Various pipes are buried in the city as needed, such as water pipes, gas pipes and hydrogen pipes. As the time passes, buried pipes becomes aged due to crack, etc. these pipes has the risk of accidents such as explosion and leakage. To prevent the risks, many pipes are repaired or replaced, but the location of the pipes can also be changed. Failure to identify the location of the altered pipe may cause an accident by touching the pipe. In this paper, we propose a method to detect buried pipes by gathering the GPR images by using GPR and Learning with Faster R-CNN. Then experiments was carried out by raw data sets and data sets augmentation applied to increase the amount of images.

• Current Applied Physics
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• v.18 no.12
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• pp.1546-1552
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• 2018

The polymer nanocomposite as a gate dielectric film was prepared via sol-gel method. The formation of crosslinked structure among nanofillers and polymer matrix was proved by Fourier transform infrared spectroscopy (FT-IR). Differential thermal analysis (DTA) results showed significant increase in the thermal stability of the nanocomposite with respect to that of pure polymer. The nanocomposite films deposited on the p- and n-type Si substrates formed very smooth surface with rms roughness of 0.045 and 0.058 nm respectively. Deconvoluted $Si_{2s}$ spectra revealed the domination of the Si-OH hydrogen bonds and Si-O-Si covalence bonds in the structure of the nanocomposite film deposited on the p- and n-type Si semiconductor layers respectively. The fabricated n-channel field-effect-transistor (FET) showed the low threshold voltage and leakage currents because of the stronger connection between the nanocomposite and n-type Si substrate. Whereas, dominated hydroxyl groups in the nanocomposite dielectric film deposited on the p-type Si substrate increased trap states in the interface, led to the drop of FET operation.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.580-586
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• 2023

Diversified fuel types such as methanol, hydrogen, liquefied natural gas, ammonia, biofuels, have been come to fore in consideration of the limitations, regulations, environmental perception and efficient use of resources on maritime sector. NE is described as a substantial alternative energy source on the marine vessels in the sense of de-carbonization and fuel efficiency activities carried out by IMO. Although NPVs have been constructed for the merchant, navy and supply fields over the years, their numbers are few and working ranges are quite limited. NE generation techniques, reactor types, safety and security issues in case of any leakage or radiation pollution are analyzed and comparisons are performed between fossil-based fueled and NP based on icebreakers. The comparison are conducted on the basis of dimensions, resistances and operational competences by the VIKOR. NP icebreakers operated in recent years occupy a notable position in the ranking, although fossil fueled ones are most prevalent. Consequently, refueling period and emissions are the principal benefits of NPVs. Nevertheless, the use of such systems on marine vessels especially for merchant ships may come to the fore when all concerns in terms of safety, security and society are resolved since the slightest mistake can have irreversible consequences.

• Restorative Dentistry and Endodontics
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• v.25 no.1
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• pp.144-152
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• 2000

Intracoronal bleaching is currently disregarded by many clinicians because of the potential consequence of cervical resorption. To prevent this complication it is recommended that intra coronal barrier materials be placed over the root canal obturation and sodium perborate be used with water rather than with hydrogen peroxide. The purpose of this study was to evaluate the amount of the hydrogen peroxide penetration according to the difference in intracanal base materials and sodium perborate preparation. Fifty extracted intact premolars were instrumented, and filled with gutta-percha. And then the outer surface of the teeth was sealed with wax exposing the CEJ. The prepared teeth were placed in plastic tubes containing 1.5ml distilled water with their entire root submerged into the solution, The teeth were divided into the following five groups. In the first two groups gutta-percha was removed without placement of barrier, and then water or superoxole(30% $H_2O_2$) with sodium perborate were used respectively for bleaching. In the other three groups, after removal of gutta-percha, an intracanal isolating barrier(ZPC, IRM, Fuji II LC) was placed and then bleached with sodium perborate and superoxole. The bleaching procedure was performed 4 times with 1 week interval. The results were as follows : 1. All the groups showed a tendency of increasing penetration amount with increasing treatment times(P<0.05). 2. After the 1st and 2nd treatments, there was no significant difference in microleakage among the groups. 3. After the 3rd bleaching with superoxole and sodium perborate, there was no significant difference in microleakage between gutta-percha alone group and gutta-percha with ZPC, Fuji II LC barrier group. But significant difference was found between IRM barrier group and other groups(P<0.01). 4. After the 4th bleaching with superoxole and sodium perborate, there was no significant difference between gutta-percha alone group and gutta-percha with barrier groups. 5. After the 4th treatment, the group bleached with sodium perborate and water without barrier showed lower hydrogen peroxide penetration than that of other groups(P<0.01).

• Asian Journal of Turfgrass Science
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• v.25 no.1
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• pp.17-21
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• 2011

Korean bennudagrass collections showed diverse genetic variations in their morphology, growth habit, and cytological aspects. Chromosome number and nuclear DNA content of the bennudagrasses indicated a ploidy level ranging from triploid (2n=3x) to hexaploid (2n=6x). In this study, we investigated the different responses of antioxidant enzymes (superoxide dismutase, catalase, peroxidase, ascorbate peroxidase) and cell membrane stability of those bennudagrass cytotypes to lower temperature and shorter day length, which meets a dormant induction in Korea. All the antioxidant enzymes were found to be higher during dormant stage, while the heme-containing catalase which converts hydrogen peroxide ($H_2O_2$) to water and oxygen molecules was activated before dormant initiation in the three cytotypes except for hexaploid bennudagrass. The triploid and tetraploid which exhibited relatively finer leaves and a rapid establishment speed were found to show increased activities of superoxide dismutase and peroxidase enzyme. The malondialdehyde(MDA) which is a product of lipid peroxidation in the cell membrane damaged by the hydroxyl radical was increased in all cytotypes as temperature declined, and tri- and tetraploids which had more protective antioxidant enzymes demonstrated a significantly lower MDA production. Similarly electrolyte leakage was higher in penta- and hexaploidy, seemingly more damage to cell membrane when low temperature was implemented. Results indicated that antioxidant responses of different cytotypes were genetically specific, which needs to be investigated the relevance with the low temperature tolerance in the bermudagrass further at the molecular level.