• The Journal of Advanced Prosthodontics
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• v.14 no.4
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• pp.212-222
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• 2022

PURPOSE. To evaluate and compare the effect of impression type (conventional vs digital) and the number of implants on the time from the impressions to the generation of working casts of mandibular implant-supported fixed completearch frameworks, as well as on patient satisfaction. MATERIALS AND METHODS. 17 participants, 3 or 4 implants, received 2 types of digital impression methods (DI) and conventional (CI). In DI, two techniques were performed: scanning with the scan bodies (SC) and scanning with a device attached to the scan bodies (SD) (BR 10 2019 026265 6). In CI, the making of a solid index (SI) and open-tray impression (OT) were used. The outcomes were used to evaluate the time and the participant satisfaction with conventional and digital impressions. The time was evaluated through the timing of the time obtained in the workflow in the conventional and digital impression. The effect of the number of implants on time was also assessed. Satisfaction was assessed through a questionnaire based on seven. The Wilcoxon test used to identify the statistical difference between the groups in terms of time. The Mann-Whitney test was used to analyze the relationship between the time and the number of implants. Fisher's test was used to assess the patient satisfaction (P<.05). RESULTS. The time with DI was shorter than with CI (DI, $\tilde{x}=02:58$; CI, $\tilde{x}=31:48$) (P<.0001). The arches rehabilitated with 3 implants required shorter digital impression time (3: $\tilde{x}=05:36$; 4: $\tilde{x}=09:16$) (P<.0001). Regarding satisfaction, the DI was more comfortable and pain-free than the CI (P<.005). CONCLUSION. Digital impressions required shorter chair time and had higher patient acceptance than conventional impressions.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.12
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• pp.18-23
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• 2009

The effect of hydrogen-nitrogen annealing on the interface trap properties of Metal-Oxide-Nitride-Oxide-Silicon (MONOS) capacitors is investigated by analyzing the capacitors' gate leakage current and the interface trap density between the Si and $SiO_2$ layer. MONOS samples annealed at $850^{\circ}C$ for 30 s by rapid thermal annealing (RTA) are treated by additional annealing in a furnace, using annealing eases $N_2$ and 2% hydrogen and 98% nitrogen gas mixture $(N_2-H_2)$ at $450^{\circ}C$ for 30 mins. Among the three samples as-deposited, annealed in $N_2$ and $N_2-H_2$, MONOS sample annealed in an $N_2-H_2$ environment is found to have the lowest increase of interface-trap density from the capacitance-voltage experiments. The leakage current of sample annealed in $N_2-H_2$ is also lower than that of sample annealed in $N_2$.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.10
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• pp.671-677
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• 2001

A RuO$_2$ Schottky photo-detector was designed and fabricated with GaN layers on the sapphire substrate. For good absorption of UV light, an epitaxial structure with undoped GaN(0.5 ${\mu}{\textrm}{m}$)/n￣-GaN(0.1${\mu}{\textrm}{m}$)/n＋-GaN(1.5${\mu}{\textrm}{m}$) was grown by MOCVD. The structure had the carrier concentrations of 3.8$\times$10$^{18}$ cm￣$^3$, the mobility of 283$\textrm{cm}^2$/V.s. After ECR etching process for mesa structure with the diameter of about 500${\mu}{\textrm}{m}$, Al ohmic contact was formed on GaN layer. After proper passivation between the contacts with Si$_3$/N$_4$, was formed on undoped GaN layer. The fabricated Schottky diode had a specific contact resistance of 1.15$\times$10$^{-5}$ ［$\Omega$.$\textrm{cm}^2$］. It has a low leakage current of 305 pA at -5 V, which was attributed by stable characteristics of RuO$_2$ Schottky contact. In optical measurement, it showed the high UV to visible extinction ratio of 10$^{5}$ and very high responsivity of 0.23 A/W at the wavelength of 365nm.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.7
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• pp.486-493
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• 2003

Schottky type A $l_{0.33}$G $a_{0.67}$N ultraviolet photodetectors were fabricated on the MOCVD grown AlGaN/ $n^{＋}$-GaN and AlGaN/AlGaN interlayer/ $n^{＋}$-GaN structures. The grown layers have the carrier concentrations of -$10^{18}$, and the mobilities were 236 and 269 $\textrm{cm}^2$/V.s, respectively. After mesa etching by ICP etching system, the Si3N4 layer was deposited for passivation between the contacts and Ti/AL/Ni/Au and Pt were deposited for ohmic and Schottky contact, respectively. The fabricated Pt/A $l_{0.33}$G $a_{0.67}$N Schottky diode revealed a leakage current of 1 nA for samples with interlayer and 0.1$\mu\textrm{A}$ for samples without interlayer at a reverse bias of -5 V. In optical measurement, the Pt/A $l_{0.33}$G $a_{0.67}$N diode with interlayer showed a cut-off wavelength of 300 nm, a prominent responsivity of 0.15 A/W at 280 nm and a UV-visible extinction ratio of 1.5x$10^4./TEX>.

• Applied Chemistry for Engineering
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• v.31 no.2
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• pp.179-186
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• 2020

In this study, chitosan/zeolite composites were prepared by using basalt-based zeolite impregnated with aqueous chitosan solution for the adsorptive separation of CO₂. The prepared composites were characterized by scanning electron microscopy (SEM), Fourier-transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption analysis. In addition, the adsorption equilibrium isotherms for CO₂ and N₂ were measured at 298 K using a volumetric adsorption system, and the results were analyzed by applying adsorption isotherm equations (Langmuir, Freundlich, and Sips) and energy distribution function. It was found that CO₂ adsorption capacities were well correlated with the structural characteristics of chitosan and zeolite, and the ratio of elements [N/C, Al/(Si + Al)] formed on the surface of the composite. Moreover, the CO₂/N₂ adsorption selectivity was calculated under the mixture conditions of 15 V : 85 V, 50 V : 50 V, and 85 V : 15 V using the Langmuir equation and the ideal adsorption solution theory (IAST).

• Journal of Korean Society of Environmental Engineers
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• v.34 no.11
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• pp.735-742
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• 2012

This study tried to find a suitable method for enhancing the foam stability of cationic surfactants that normally generate less foam or no foam. Several trials were made to enhance the foam stability: addition of anionic surfactant, colloids and polymer. Cationic starch (CA-ST) did not form foam at all, while the foam stability of two other cationic surfactant also showed low levels; methyl triethanol ammonium methyl sulfate distearyl ester (CEQ90) for 46 sec. and Cetyl trimethyl ammonium chloride (CM29) for 31 seconds. Foam stability of cationic surfactants were significantly affected by addition of anionic surfactant, sodium dodecyl sulfate (SDS). Foam stability of CA-ST was significantly enhanced by addition of SDS, while those of CEQ90 and CM29 were decreased. Addition of colloids ($SiO_2$, kaolin) and polyvinyl alcohol (PVA) enhanced foam stabilities of CEQ90 and CM29. However, CA-ST did not form foam even in the presence of colloids or PVA. Effect of simultaneous addition of colloids and anionic surfactant on foam stability of cationic surfactant showed that foam stability of cationic surfactant was more influenced by addition of anionic surfactant than colloids. Effect of simultaneous addition of PVA and anionic surfactant on the foam stability of cationic surfactant also showed that presence of anionic surfactant significantly affect the foam stability of cationic surfactant. Foam stability of CA-ST was greatly increased to 8,780 seconds by addition of SDS 0.14% and PVA 2.5%. The foam stability of CA-ST was 8 times higher than CEQ 90. This study suggested that cationic surfactants not forming foam can generate foam by addition of anionic surfactant and its stability can be additionally increased by addition of colloids and PVA. The study results showed that enhancement in foam stability of cationic surfactant was prominently affected by the concentration of anionic surfactant added.

• Journal of Chest Surgery
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• v.41 no.6
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• pp.679-686
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• 2008

Background: Cellular remnants in the bioprosthetic heart valve are known to be related to a host's immunologic response and they can form the nidus for calcification. The extracellular matrix of the decellularized valve tissue can also be used as a biological scaffold for cell attachment, endothelialization and tissue reconstitution. Thus, decellularization is the most important part in making a bioprosthetic valve and biological caffold. Many protocols and agents have been suggested for decellularization, yet there ave been few reports about the effect of a treatment with hypotonic solution prior to chemical or enzymatic treatment. This study investigated the effect of a treatment with hypotonic solution and the appropriate environments such as temperature, the treatment duration and the concentration of sodium dodecylsulfate (SDS) for achieving proper decellularization. Material and Method: Porcine aortic valves were decellularized with odium dodecylsulfate at various concentrations (0.25%, 0.5%), time durations (6, 12, 24 hours) and temperatures ($4^{\circ}C$, $20^{\circ}C$)(Group B). Same the number of porcine aortic valves (group A) was treated with hypotonic solution prior to SDS treatment at the same conditions. The duration of exposure to the hypotonic solution was 4, 7 and 14 hours and he temperature was $4^{\circ}C$ and $20^{\circ}C$, respectively. The degree of decellularization was analyzed by performing hematoxylin and eosin staining. Result: There were no differences in the degree of decellularization between the two concentrations (0.25% 0.5%) of SDS. Twenty four hours treatment with SDS revealed the best decellularization effect for both roups A and B at the temperature of $4^{\circ}C$, but there was no differences between the roups at $20^{\circ}C$. Treatment with hypotonic solution (group A) showed a better ecellularization effect at all the matched conditions. Fourteen hours treatment at $4^{\circ}C$ ith ypotonic solution prior to 80S treatment revealed the best decellularization effect. The treatment with hypotonic solution at $20^{\circ}C$ revealed a good decellularization effect, but his showed significant extracellular matrix destruction. Conclusion: The exposure of porcine heart valves to hypotonic solution prior to SDS treatment is highly effective for achieving decellularization. Osmotic treatment with hypotonic solution should be considered or achieving decellularization of porcine aortic valves. Further study should be carried out to see whether the treatment with hypotonic solution could reduce the exposure duration and concentration of chemical detergents, and also to evaluate how the structure of the extracellular matrix of the porcine valve is affected by the exposure to hypotonic solution.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.7
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• pp.7-14
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• 2009

In this paper, the effects of annealing conditions on the structural ((002) intensity, FWHM, d-spacing, grain size, (002) peak position), optical (UV peak, UV peak position) and electrical properties (carrier concentrations, resistivity, mobility) of ZnO films were investigated. ZnO films were deposited onto SiO$_2$/si substrates by RF magnetron sputtering from a ZnO target. The substrate was not heated during deposition. ZnO films were annealed in temperature ranges of $500\sim650^{\circ}C$ in the O$_2$ flow for 5$\sim$20 min. The film average thicknesses were in the range of 291 nm. The surface morphologies and structures of the samples were characterize by SEM and XRD, respectively. The optical properties were evaluated by photoluminescence (PL) measurement at room temperature (RT) using a He-Cd 325 nm laser. As the annealing temperature and time vary, the following relations were also observed: (1) proportional relationships among UV intensity (002) intensity, and grain size exist, (2) UV intensity is inversely proportional to FWHM, (3) there is no special relationship between UV intensity and electron carrier concentrations, (4) d-spacing is inversely proportional to (002) peak position, (5) UV peak position in the range of 3.20$\sim$3.24 eV means that ZnO films have a n-type conductivity which was consistent with that obtained from the electrical property, (6) the optimal conditions for the best optical and structural characteristics were found to be oxygen fraction, (O$_2$/(O$_2$+Ar)) of 0.2, RF power of 240W, substrate temperature of RT, annealing condition of 600$^{\circ}C$ for 20 min, and sputtering pressure of 20 mTorr.

• The Journal of Korean Society for Radiation Therapy
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• v.34
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• pp.21-30
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• 2022

Purpose: The purpose of this study is to evaluate the effectiveness of oral positioning stent, the BinkieRT^TM in radiation treatment for head and neck cancer patients in terms of tongue positions reproducibility, tongue doses and material properties. Materials and Methods: 24 cases using BinkieRT^TM during radiation treatments were enrolled. The tongue was contoured on planning CT and CBCT images taken every 3 days during treatment, and then the DSC and center of tongue shift values were analyzed to evaluate the reproducibility of the tongue. The tongue dose was compared in terms of dose distribution when using BinkieRT^TM and different type of oral stents (mouthpiece, paraffin wax). Randomly selected respective 10 patients were measured tongue doses of initial treatment plan for nasal cavity and unilateral parotid cancer. Finally, In terms of material evaluation, HU and relative electron density were identified in RTPS. Results: As a result of DSC analysis, it was 0.8 ± 0.07, skewness -0.8, kurtosis 0.61, and 95% CI was 0.79~0.82. To analyze the deviation of the central tongue shift during the treatment period, a 95% confidence interval for shift in the LR, SI, and AP directions were indicated, and a one-sample t-test for 0, which is an ideal value in the deviation(n=144). As a result of the t-test, the mean and SD in the LR and SI directions were 0.01 ± 0.14 cm (p→.05), 0.03 ± 0.25 cm (p→.05), and -0.08 ± 0.25 cm (p ←.05) in the AP direction. In the case of unilateral parotid cancer patients, the Dmean to the tongue of patients using BinkieRT^TM was 16.92% ± 3.58% compared to the prescribed dose, and 23.99% ± 10.86% of patients with Paraffin Wax, indicating that the tongue dose was relatively lower when using BinkieRT^TM (p←.05). On the other hand, among nasal cavity cancer patients, the Dmean of tongue dose for patients who used BinkieRT^TM was 4.4% ± 5.6%, and for those who used mouthpiece, 5.9% ± 6.8%, but it was not statistically significant (p→.05). The relative electron density of Paraffin Wax, BinkieRT^TM and Putty is 0.94, 0.99, 1.26 and the mass density is 0.95, 0.99 and 1.32 (g/cc), Transmission Factor is 0.99, 0.98, 0.96 respectively. Conclusion: The result of the tongue DSC analysis over the treatment period was about 0.8 and Deviation of the center of tongue shifts were within 0.2 cm, the reproducibility was more likely excellent. In the case of unilateral head and neck cancer patients, it was found that the use of BinkieRT^TM rather than Paraffin Wax or Putty can reduce the unnecessary dose irradiated to the tongue. This study might be useful to understand of BinkieRT^TM's properties and advantages. And also it could be another considered option as oral stent to keep the reproducibility of tongue and reducing dose during head and neck radiation treatments.

• Korean Journal of Psychosomatic Medicine
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• v.10 no.1
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• pp.37-47
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• 2002

Objective : Previous studies have suggested an association between sleep-related breathing disorder (SRBD) and several psychological problems, and there were increasing recognition of the link. The purpose of this study is to evaluate the characteristic profiles of MMPI and SCL-90-R in patients with SRBD. Methods : This study consisted of 80 SRBD patients(73 men, 7 women) referred from Sleep Disorder Clinic of Dong-A University Hospital, Busan, Korea. Basic informations including demographic findings and physical examination were collected. Subjects completed the Epworth Sleepiness Scale(ESS), Minnesota Multiphasic Personality Inventory(MMPI), and Symptom Check List-90-Revision (SCL-90-R) prior to standard overnight polysomnography that was performed at hospital sleep laboratory. SRBD was divided into two groups of primary snoring(PS) and obstructive sleep apnea(OSA) according to polysomnographic findings. Results : SRBD showed significant elevation rate of Hs, D, and Hy scales of MMPI and SOM scale of SCL-90-R, which exceeded the rate expected in normal individuals(>5%, 2SD). On comparison of clinical scales of SCL-90-R, OSA group had significantly greater mean score than that of PS group in terms of O-C, DEP, PAR, GSI(p<0.05), SOM and PST(p<0.01). OSA group also showed significantly higher elevation rate in Hs scale of MMPI and SOM scale of SCL-90-R than that of PS. Among OSA group, three scales of MMPI(D, Pt, Si) and three scales of SCL-90-R(ANX, PAR, PSDI) had significant correlation with some PSG variables including total sleep time and sleep efficiency. Among PS group, two scales of MMPI(Hy and Pt), elevation rate of MMPI scales and three scales of SCL-90-R(I-S, PAR, PSDI) had significant correlation with some PSG variables including sleep efficiency, sleep latency and REM sleep percent. Conclusion : The above results suggest that SRBD show neurotic profiles in MMPI and SCL-90-R. This study also clearly indicates that PS group are suffered from clinically meaningful psychiatric symptoms, which are quantitatively lessened but qualitatively similar as compared to that of OSA group.