• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.62-62
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• 2015

In this study, we study the effects of CF4 plasma treatment on the characteristics of enhancement mode (E-mode) AlGaN/GaN high electron mobility transistors (HEMTs). The CF4 plasma is generated by inductively coupled plasma reactive ion etching (ICP-RIE) system. The CF4 gas is decomposed into fluorine ions by ICP-RIE and then fluorine ions will effect the AlGaN/GaN interface to inhibit the electron transport of two dimension electron gas (2DEG) and increase channel resistance. The CF4 plasma method neither like the recessed type which have to utilize Cl2/BCl3 to etch semiconductor layer nor ion implantation needed high power to implant ions into semiconductor. Both of techniques will cause semiconductor damage. In the experiment, the CF4 treatment time are 0, 50, 100, 150, 200 and 250 seconds. It was found that the devices treated 100 seconds showed best electric performance. In order to prove fluorine ions existing and CF4 plasma treatment not etch epitaxial layer, the secondary ion mass spectrometer confirmed fluorine ions truly existing in the sample which treatment time 100 seconds. Moreover, transmission electron microscopy showed that the sample treated time 100 seconds did not have etch phenomena. Atomic layer deposition is used to grow Al2O3 with thickness 10, 20, 30 and 40 nm. In electrical measurement, the device that deposited 20-nm-thickness Al2O3 showed excellent current ability, the forward saturation current of 210 mA/mm, transconductance (gm) of 44.1 mS/mm and threshold voltage of 2.28 V, ION/IOFF reach to 108. As IV concerning the breakdown voltage measurement, all kinds of samples can reach to 1450 V.

• The Journal of Advanced Prosthodontics
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• v.4 no.2
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• pp.103-108
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• 2012

PURPOSE. Debonding of a composite resin core of the fiber post often occurs at the interface between these two materials. The aim of this study was to evaluate the effects of different surface treatment methods on bond strength between fiber posts and composite core. MATERIALS AND METHODS. Sixty-four fiber posts were picked in two groups (Hetco and Exacto). Each group was further divided into four subgroups using different surface treatments: 1) silanization; 2) sandblasting; 3) Treatment with 24% $H_2O_2$, and 4) no treatment (control group). A cylindrical plexiglass matrix was placed around the post and filled with the core resin composite. Specimens were stored in 5000 thermal cycles between $5^{\circ}C$ and $55^{\circ}C$. Tensile bond strength (TBS) test and evaluation using stereomicroscope were performed on the specimen and the data were analyzed using two-way ANOVA, Post Hoc Scheffe tests and Fisher's Exact Test (${\alpha}$=.05). RESULTS. There was a significant difference between the effect of different surface treatments on TBS ($P$ <.001) but different brands of post ($P$=.743) and interaction between the brand of post and surface treatment ($P$=.922) had no significant effect on TBS. Both silanization and sandblasting improved the bonding strength of fiber posts to composite resin core, but there were not any significant differences between these groups and control group. CONCLUSION. There was not any significant difference between two brands of fiber posts that had been used in this study. Although silanization and sandblasting can improve the TBS, there was not any significant differences between surface treatments used.

• Journal of Satellite, Information and Communications
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• v.10 no.4
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• pp.83-86
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• 2015

In this paper, we propose a real-tim measurement management system UI development linked the Water treatment facilities broadband Convergence Network. The sensor and the image data received by the server develop a program to interact with Web through water treatment facilities broadband convergence network. So, Separately develop UI capable of independently operating. Building a web server for remote monitoring of the transmission sensor and the image data. And Monitoring and control is possible the sensor data and image data through the Web-based UI. We can grasp the current state such as measurement time, concentration and depth of interface through the proposed real-time measurement management system UI development liked the water treatment facilities broadband convergence network. So, we can check in whether the normal operation of water treatment facilities and whether the casualties such as fire and security. As well as real time to see the information at a glance due to UI development can be raal-time monitoring of real-time measurement management system.

• Electrical & Electronic Materials
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• v.8 no.1
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• pp.56-63
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• 1995

MESFETs of the Ti/Au and Ti/Pd/Au gate were fabricated on n-type GaAs. Interdiffusion at Schottky interfaces, Schottky contact properties, and MESFET characteristics with heat treatment were investigated. Ti of Ti/Au contact and Pd of Ti/Pd/Au contact acted as a barrier metal against interdiffusion of Au at >$220^{\circ}C$. Pd of Ti/Pd/Au contact acted as a barrier metal even at >$360^{\circ}C$, however, Ti of Ti/Au contact promoted interdiffusion of Au instead of role of barrier metal. As the heat treatment temperature increases, in the case of both contact, saturated drain current and pinch off voltage decreased, open channel resistance increased, and degree of parameter variation in Ti/Au gate was higher than in Ti/Pd/Au gate at >$360^{\circ}C$ Schottky barrier height of Ti/Au and Ti/Pd/Au contacts was 0.69eV and 0.68eV in the as-deposited state, respectively, and Fermi level was pinned in the vicinity of 1/2Eg. As the heat treatment temperature increases, barrier height of Ti/Pd/Au contact increased, however, decreased at >$360^{\circ}C$ in the case of Ti/Au contact. Ideality factor of Ti/Au contact was nearly constant regardless of heat treatment, however, increased at >$360^{\circ}C$ in the case of Ti/Au contact. From the results above, Ti/Pd/Au was stable gate metal than Ti/Au.

• Nutrition Research and Practice
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• v.12 no.1
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• pp.29-40
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• 2018

BACKGROUND/OBJECTIVES: Ultraviolet radiation (UV) is a major cause of skin photoaging. Previous studies reported that ethanol extract (PET) of Prunus persica (L.) Batsch flowers (PPF, peach flowers) and its subfractions, particularly the ethylacetate (PEA) and n-butanol extracts (PBT), have potent antioxidant activity and attenuate the UV-induced matrix metalloproteinase (MMP) expression in human skin cells. In this study, we investigated the protective activity of PPF extract against UV-induced photoaging in a mouse model. MATERIALS/METHODS: Hairless mice were treated with PET or a mixture of PEA and PBT either topically or orally along with UV irradiation. Histological changes and biochemical alterations of mouse skin were examined. Major phenolic compounds in PPF extract were analyzed using an ACQUITY UPLC system. RESULTS: The overall effects of topical and oral treatments with PPF extract on the UV-induced skin responses exhibited similar patterns. In both experiments, the mixture of PEA and PBT significantly inhibited the UV-induced skin and epidermal thickening, while PET inhibited only the UV-induced epidermal thickening. Treatment of PET or the mixture of PEA and PBT significantly inhibited the UV-induced MMP-13 expression, but not type I collagen expression. Topical treatment of the mixture of PEA and PBT with UV irradiation significantly elevated catalase, superoxide dismutase (SOD) and glutathione-peroxidase (GPx) activities in the skin compared to those in the UV irradiated control group, while oral treatment of the mixture of PEA and PBT or PET elevated only catalase and SOD activities, but not GPx. Thirteen phytochemical compounds including 4-O-caffeoylquinic acid, cimicifugic acid E and B, quercetin-3-O-rhamnoside and kaempferol glycoside derivatives were identified in the PPF extract. CONCLUSIONS: These results demonstrate that treatment with PET or the mixture of PEA and PBT, both topically or orally, attenuates UV-induced photoaging via the cooperative interactions of phenolic components having anti-oxidative and collagen-protective activities.

• Journal of the Korean Society for Heat Treatment
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• v.9 no.1
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• pp.12-18
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• 1996

Austenite(${\gamma}$) grain size, ${\varepsilon}$ martensite volume fraction and damping capacity of Fe-17%Mn alloy have been investigated as a function of solution treatment temperature of $600^{\circ}C$ to $1100^{\circ}C$. With increasing the solution temperature, ${\gamma}$ grain size, ${\varepsilon}$ martensite content and damping capacity are increased, while the hardness is decreased. When ${\gamma}$ grains are small, ${\varepsilon}$ plates grow in only one direction in each ${\gamma}$ grain. However, if the ${\gamma}$ grains are large in accordance with high solution treating temperature, several ${\varepsilon}$ variants with different orientations are formed and intersected each other in each ${\gamma}$ grain. In spite of small ${\varepsilon}$ martensite content, the damping capacity of the specimen which was annealed at $700^{\circ}C$, followed by subzero treatment at $-196^{\circ}C$, is almost equal to that of the specimen annealed at $1000^{\circ}C$ and subsequently quenched to room temperature. From this result it is suggested that the damping capacity of Fe-17%Mn alloy having fine ${\gamma}$ grains is mainly attributed to the movement of ${\gamma}/{\varepsilon}$ interface without the operation of other damping sources such as ${\varepsilon}/{\varepsilon}$ boundaries and stacking faults in ${\varepsilon}$ reported previously.

• Journal of Surface Science and Engineering
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• v.46 no.1
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• pp.9-15
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• 2013

The effect of the additionally applied electrical current on the adhesion strength between electroless Cu and polyimide films was investigated. Peel tests were performed after applying electrical current within the range from 0.1 to 100 mA for the duration from 1 to 30 minutes. Sample with more than 1 mA of additional electrical current for 1 minute showed higher adhesion strength than that without additional electrical current. However, samples with 10 mA of additional electrical current for more than 10 miniutes showed the degradation of adhesion strength. Ra and RMS values of the peeled polyimide surface were proportional to the adhesion strength though there were no significant changes in the morphology of the peeled surfaces with varied amount and time-length of additional electrical current. Applying electrical current could increase the density of chemical bonding, which results in increase of the adhesion strength between copper and polyimide. However, in the case of applying additional electrical current for excessive amount or time, the degradation of the adhesion strength owing to the formation of copper oxide at the interface could occur.

• Composites Research
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• v.23 no.6
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• pp.32-38
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• 2010

The effect of the atmospheric pressure plasma(APP) treatments is experimentally investigated to ascertain the optimum condition to yield the best adhesive properties between a polyamide woven fabric and acrylonitrile butadiene rubber(NBR). For the atmospheric pressure flame plasma(APFP) treatment, the optimum number of treatment at given conditions is 2 times. The thermal deformation of the fabric is more serious with increasing the number of APFP treatment. The adhesive strength of the case with APFP treated fabric is increased about 35% when compare to the case with non-APFP treated one for the interface(bonding agent one or two coatings). When the surface is coated twice with the bonding agent, the adhesive energy with APFP treated fabric is increased about 4 times. It was found that the surface modification of polyamide woven fabric by APFP treatment is a fast, economic and applicable method to improve the adhesive properties between woven fabric and rubber when compared to other APP treatments.

• Electrical & Electronic Materials
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• v.8 no.5
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• pp.619-625
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• 1995

Polycrystalline CdTe thin film has been studied for photovoltaic application due to the 1.45 eV band gap energy ideal for solar energy conversion and high absorption coefficient. The formation of low resistance contact to p-CdTe is difficult because of large work function(>5.5eV). Common methods for ohmic contact to p-CdTe are to form a p+ region under the contact by in-diffusion of contact material to reduce the barrier height and modify a p-CdTe surface layer using chemical treatment. In this study, the surface chemical treatment of p CdTe was carried out by H$\_$3/PO$\_$4/+HNO$\_$3/ or K$\_$2/Cr$\_$2/O$\_$7/+H$\_$2/SO$\_$4/ solution to provide a Te-rich surface. And various thin film contact materials such as Cu, Au, and Cu/Au were deposited by E-beam evaporation to form ohmic contact to p-CdTe. After the metallization, post annealing was performed by oven heat treatment at 150.deg. C or by RTA(Rapid Thermal Annealing) at 250-350.deg. C. Surface chemical treatments of p-CdTe thin film improved metal/p-CdTe interface properties and post heat treatment resulted in low contact resistivity to p-CdTe.Of the various contact metal, Cu/Au and Cu show low contact resistance after oven and RTA post-heat treatments, respectively.

• Journal of Physiology & Pathology in Korean Medicine
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• v.34 no.5
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• pp.269-278
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• 2020

The purpose of this study is to report the effect of the Korean acupuncture treatment and Open Wet Dressing Therapy(OPWT) for pressure ulcer. From November 2015 to January 2020, 9 patients with 3rd or 4th graded pressure ulcer over 70 years of age who were admitted to a care hospital with underlying diseases such as cerebral infarction, brain hemorrhage, and Parkinson's disease were treated by acupuncture and OPWT. Photographs of lesions were used to evaluate the changes in condition of pressure ulcer. Acupuncture was performed 4 times a week along the border between the normal epidermal region and the pressure ulcer granulation tissue in contact with the pressure ulcer interface. OPWT to create a wet environment for wounds by washing the wounds 1-2 times a day with normal saline solution and covering them with food wrap was combined. In addition, for objective treatment progress evaluation, size, stage and condition of pressure ulcer were regularly monitored using the classification method of The National Pressure Ulcer Advisory Panel (NPUAP) according to the condition and depth of the damaged tissue and The Pressure Ulcer Scale for Healing(PUSH tool 3.0). After acupuncture treatment and OPWT, the pressure ulcer of patients was cured in as short as 66 days and as long as 274 days (average 170 days). This study shows that acupuncture treatment and OPWT were effective to treat pressure ulcer.