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We used a pulsed green laser to activate indium gallium zinc oxide thin-film transistors (IGZO TFTs). The IGZO films with large bandgaps (>3 eV) were easily activated by heat delivered by a pulsed green laser to the gate, source, and drain metal electrodes. The IGZO TFTs were quickly and selectively activated in the absence of conventional annealing. Compared to the IGZO TFTs that were annealed at 300°C, the IGZO TFTs that were activated via pulsed green laser irradiation exhibited superior electrical characteristics: a field effect mobility of 11.98 ± 0.64 cm2 V−1 s−1, a subthreshold swing of 0.33 ± 0.02 V dec−1, and an on/off ratio of 8.28 × 109 ± 7.42 × 109, which were attributable to increases in the number of metal–oxide (M-O) bonds and oxygen vacancies, and reduced levels of OH-related species. The pulsed green laser broke weak chemical M-O bonds in the IGZO films through dihydroxylation of the OH-related species, and then strengthened the residual M-O bonds via heat transfer from the metal electrodes. This new activation process could replace conventional annealing and is expected to expand the applications of flexible and transparent devices.

Background: Recently, three-dimensional (3D) printing has been hailed as a disruptive technology in dentistry. Among 3D printers, a digital light processing (DLP) 3D printer has certain advantages, such as high precision and relatively low cost. Therefore, the latest trend in resin crown manufacturing is the use of DLP 3D printers. However, studies on the internal fitness of such resin crowns are insufficient. The recently introduced 3D evaluation method makes it possible to visually evaluate the error of the desired area. The purpose of this study is to evaluate the internal fitness of resin crowns fabricated a by DLP 3D printer using the 3D evaluation method. Methods: The working model was chosen as the maxillary molar implant model. A total of 20 resin crowns were manufactured by dividing these into two groups. One group was manufactured by subtractive manufacturing system (PMMA), while the other group was manufactured by additive manufacturing system, which uses a DLP 3D printer. Resin crowns data were measured using a 3D evaluation program. Internal fitness was calculated by root mean square (RMS). The RMS was calculated using the Geomagic Verify software, and the mean and standard deviation (SD) were measured. For statistical analysis, IBM SPSS Statistics for Windows ver. 22.0 (IBM Corp., USA) was used. Then, independent t-test was performed between the two groups. Results: The mean±SD of the RMS were 41.51±1.51 and 43.09±2.32 for PMMA and DLP, respectively. There was no statistically significant difference between PMMA and DLP. Conclusion: Evaluation of internal fitness of the resin crown made using a DLP 3D printer and subtractive manufacturing system showed no statistically significant differences, and clinically acceptable results were obtained.

Sputter-processed oxide films are typically annealed at high temperature (activation process) to achieve stable electrical characteristics through the formation of strong metal-oxide chemical bonds. For instance, indium-gallium-zinc oxide (IGZO) films typically need a thermal treatment at 300 °C for ≥1 h as an activation process. We propose an open-air plasma treatment (OPT) to rapidly and effectively activate sputter-processed IGZO films. The OPT effectively induces metal-oxide chemical bonds in IGZO films at temperatures as low as 240 °C, with a dwell time on the order of a second. Furthermore, by controlling the plasma-processing conditions (scan speed, distance a between plasma nozzle and samples, and gas flow rate), the electrical characteristics and the microstructure of the IGZO films can be easily tuned. Finally, OPT can be utilized to implement a selective activation process. Plasma-treated IGZO thin-film transistors (TFTs) exhibit comparable electrical characteristics to those of conventionally thermal treated IGZO TFTs. Through in-depth optical, chemical, and physical characterizations, we confirm that OPT simultaneously dissociates weak chemical bonds by UV radiation and ion bombardment and re-establishes the metal-oxide network by radical reaction and OPT-induced heat.

A novel organic material named ‘collodion’ was suggested as a gate insulator for amorphous indium gallium zinc oxide thin-film transistors (a-IGZO TFTs). To find the optimized condition of the collodion gate insulator (CGI), the following three parameters of collodion solution were controlled: (1) the concentration of collodion solution; (2) the number of stacked layers; and (3) the spin-coating speed. The single-layered diluted CGI (collodion:ethanol=1:1) that was fabricated with a 3 krpm spin-coating speed exhibited an acceptable dielectric strength (J

Proposed herein is a new technique of activation for the backplane of low-temperature amorphous indium gallium zinc oxide thin-film transistors (a-IGZO TFTs) by applying a bias voltage to gate, sou...

Activation using the simultaneous UV-thermal (U-T) treatment of sputter-processed InGaZnO (IGZO) thin-film transistors (TFTs) is suggested. This treatment was performed to lower the activation temperature from 300°C (thermal activation alone) to 150°C as well as to improve the electrical characteristics and stability. Despite the low temperature, the U-T-treated devices showed superior electrical characteristics and stability compared to the devices that were only thermally activated (300°C): the mobility improved from 5.19 ± 1.8 to 16.20 ± 1.5 cm2/Vs, the on-off ratio increased from (5.58 ± 3.21) × 108 to (2.50 ± 2.23) × 109, and the threshold voltage shift (under positive bias stress for 1000 s) decreased from 7.1 to 2.2 V. These improvements are attributed to the following two contributions: (1) generation of reactive oxygen radical at a low temperature and (2) decomposition-rearrangement of the metal oxide (MO) bonds in the IGZO active layer. Contributions (1) and (2) effectively increased the...

We fabricated wire-type indium gallium zinc oxide (IGZO) thin-film transistors (TFTs) using a self-formed cracked template based on a lift-off process. The electrical characteristics of wire-type IGZO TFTs could be controlled by changing the width and density of IGZO wires through varying the coating conditions of template solution or multi-stacking additional layers. The fabricated wire-type devices were applied to sensors after functionalizing the surface. The wire-type pH sensor showed a sensitivity of 45.4 mV/pH, and this value was an improved sensitivity compared with that of the film-type device (27.6 mV/pH). Similarly, when the wire-type device was used as a glucose sensor, it showed more variation in electrical characteristics than the film-type device. The improved sensing properties resulted from the large surface area of the wire-type device compared with that of the film-type device. In addition, we fabricated wire-type IGZO TFTs on flexible substrates and confirmed that such structures were very resistant to mechanical stresses at a bending radius of 10 mm.

동물의 에너지수지에 관한 연구는 에너지 흐름을 이해하고 동 물생태계의 기능을 파악하는데 있어 유용한 수단이 된다. 생태 계는 복잡한 먹이사슬 또는 먹이그물과 같은 영양적 구조로 집 단 간의 에너지흐름의 양에 밀접하게 관련되어 있으며, 이러한 복잡한 먹이망 속에서 그 물질의 전환에 따른 에너지 흐름을 파악하기 위해서 에너지수지를 분석하는 것이 매우 중요하다 (Klekowski and Duncan, 1975). 어느 한 생물의 개체에 유입되 는 모든 에너지는 열로써 상실하거나, 다른 영양 단계로 전이된 다. 생물학적 물질계는 물질전환에 따른 에너지 흐름에 의해서 체계화되어 있다. 그리고 먹이사슬로 또는 먹이그물과 같은 영 양적 구조는 집단의 에너지 흐름의 양에 밀접하게 관련된다. 그 러므로 에너지 흐름의 파악은 자연집단의 에너지수지를 분석하 는 것이 필요하지만, 우선 개체의 생활사에 따른 에너지수지를 정확하게 분석하는 것이 매우 중요하다(Park, 1989). 갑각류의 에너지수지에 관해서는 자연과 실험실 내 집단을 대 상으로 많은 연구가 진행되어 있으며(Clutter and Theilacker, 1971; Levine and Sulkin, 1979; Emmerson, 1984; Harms, 1987; Kim and Chin, 1991), 성장, 산소소비, 질소배설 및 섭취 에 대한 에너지 함량을 파악하여 에너지수지 방식을 통해서 그 영양적 체계를 구성해 볼 수 있다(Park, 1989). 동물의 에너지 수지에 관한 연구는 다른 영양 단계 간의 에너지 전이유형을 이 해하는 총체적 지표가 되며, 그 동물의 생산성과 생태적 효율을 예측하는 자료로서 유용하다(Vernberg and Vernverg, 1981). 가시배새우, Lebbeus groenlandicus는 십각목(Order Decapoda) 꼬마새우과(Family Hippolytidae)에 속하는 종으로 꼬마 새우과 중에서도 거대 종이며, 특히 한국산 꼬마새우과 중에서 는 가장 크다. 몸이 짧고 굵으며, 두흉갑이 짧고 거친 털로 덮여 있다. 이 종은 울릉도 근해에서 통발로 주로 어획하는데, 수심 200-400 m에 주로 서식한다. 한해성 종으로서 아한대 해역에 분포하고 있다. 우리나라 동해, 그린란드, 미국 동북부, 캐나다

Carbon nanotubes, in different forms and architectures, have demonstrated good promise as electrode material for Li-ion batteries, owing to large surface area, shorter Li-conduction distance and high electrical conductivity. However, practical application of such Li-ion batteries demands higher volumetric capacity, which is otherwise low for most nanomaterials, used as electrodes. In order to address this urgent issue, we have developed a novel 3-dimensional (3D) anode, based on multiwall carbon nanotubes (MWCNTs), for Li-ion batteries. The unique 3D design of the electrode allowed much higher solid loading of active anode material, MWCNTs in this case and resulted in more amount of Li + ion intake in comparison to those of conventional 2D Cu current collector. Though one such 3D anode was demonstrated to offer 50% higher capacity, compared to its 2D counterpart, its ability to deliver much higher capacity, by geometrical modification, is presented. Furthermore, deposition of amorphous Si (a-Si) layer on the 3D electrode (a-Si/MWCNTs hybrid structure) offered enhancement in electrochemical response. Correlation between electrochemical performances and structural properties of the 3D anodes highlights the possible charge transfer mechanism.

A new technique is proposed for the activation of low temperature amorphous InGaZnO thin film transistor (a-IGZO TFT) backplanes through application of a bias voltage and annealing at 130 °C simultaneously. In this ‘electrical activation’, the effects of annealing under bias are selectively focused in the channel region. Therefore, electrical activation can be an effective method for lower backplane processing temperatures from 280 °C to 130 °C. Devices fabricated with this method exhibit equivalent electrical properties to those of conventionally-fabricated samples. These results are analyzed electrically and thermodynamically using infrared microthermography. Various bias voltages are applied to the gate, source, and drain electrodes while samples are annealed at 130 °C for 1 hour. Without conventional high temperature annealing or electrical activation, current-voltage curves do not show transfer characteristics. However, electrically activated a-IGZO TFTs show superior electrical characteristics, comparable to the reference TFTs annealed at 280 °C for 1 hour. This effect is a result of the lower activation energy, and efficient transfer of electrical and thermal energy to a-IGZO TFTs. With this approach, superior low-temperature a-IGZO TFTs are fabricated successfully.

We investigated the use of high-pressure gases as an activation energy source for amorphous indium-gallium-zinc-oxide (a-IGZO) thin film transistors (TFTs). High-pressure annealing (HPA) in nitrogen (N2) and oxygen (O2) gases was applied to activate a-IGZO TFTs at 100 °C at pressures in the range from 0.5 to 4 MPa. Activation of the a-IGZO TFTs during HPA is attributed to the effect of the high-pressure environment, so that the activation energy is supplied from the kinetic energy of the gas molecules. We reduced the activation temperature from 300 °C to 100 °C via the use of HPA. The electrical characteristics of a-IGZO TFTs annealed in O2 at 2 MPa were superior to those annealed in N2 at 4 MPa, despite the lower pressure. For O2 HPA under 2 MPa at 100 °C, the field effect mobility and the threshold voltage shift under positive bias stress were improved by 9.00 to 10.58 cm2/V.s and 3.89 to 2.64 V, respectively. This is attributed to not only the effects of the pressurizing effect but also the metal-oxide construction effect which assists to facilitate the formation of channel layer and reduces oxygen vacancies, served as electron trap sites.

Purpose: The purpose of this study is to lay the groundwork for the development of appropriate training courses for a rapidly changing digital technology in the field of Dental technology. Methods: The subjects of this study were dental technicians, dental technology students, a professor of dental technology in Daegu and Gyeongbuk area and a self-administered structured questionnaire survey was conducted for 350 randomly selected people. Collected data were analyzed using SPSS Win 17.0 statistics program and analysis techniques include the frequency, percentage and cross-analysis. Results: The results of the survey are as follows. The usefulness of Major subjects was Full Denture laboratory (4.72 points), Dental Morphology (4.71 points), Crown and Bridge laboratory (4.69 points) in the instructor`s group. The usefulness of Major subjects was Dental Morphology (4.56 points), Full Denture (4.36 points), Crown and Bridge laboratory (4.69 points) in the student`s group. The usefulness of Major subjects was Dental Morphology (4.58 points), Dental Morphology laboratory (4.34 points), Partial Denture laboratory (4.30 points) in the dental technician`s group. Subject with the highest usefulness of required course to open was CAD/CAM lecture and laboratory, the highest proportion of 91.2% and Implant laboratory was very useful (91.2%) in the instructor`s group. Subject with the highest usefulness of required course to open was CAD/CAM lacture and laboratory, the highest proportion of 90.0% and Implant laboratory was very useful (91.2%) in the student`s group. Subject with the highest usefulness of required course to open was CAD/CAM lacture and laboratory, the highest proportion of 91.2% and Implant laboratory was very useful (90.2%) in the dental technician`s group. Conclusion: Semester of the subjects was required establishment of CAD/CAM lecture and laboratory in the third year first semester (85.1%) and Implant laboratory in the third year second semester the third year was the highest proportion of 94.1% in the instructor`s group. 87.0% of students need to open CAD/CAM lacture and laboratory in the third year first semester, Implant laboratory in the third year second semester the third year was the highest proportion of 85.0% in the student`s group. Semester of the subjects was required establishment of CAD/CAM lecture and laboratory in the third year first semester (81.0%) and Implant laboratory in the third year second semester the third year was the highest proportion of 80.0% in the dental technician`s group.

In this study, surface characteristics and cell proliferation of mechanical sandblasted Ti-30Ta-xNb surface have been investigated. Samples with three different surface preparations were used: 0.3um polished, 50um and 100um HA sandblasted. Cell culture on the specimen surface was performed with mouse osteoblast-like cells MC3T3-E1 for 2 days. Average surface roughness and surface morphology of specimens were observed using surface roughness tester, and field-emission scanning electron microscopy. The corrosion resistance was measured using electrochemical impedance spectroscopy and potentiodynamic test at 0.9% NaCl solution at 36.5oC. The average surface roughness of Ti-30Ta-xNb (x = 5, 10, 15wt%) alloys increased with increasing blasting particle size and Nb content. Cell adhered well on the rough surface of Ti-30Ta-xNb (x = 5, 10, 15wt%) alloys. Cell growth increased as Nb content increased. From the electrochemical test, Ti-30Ta-xNb (x = 5, 10, 15wt%) alloys blasted by 100um HA particles showed lower dissolution rate than that by 50um HA particles, especially, Ti-30Ta-15Nb alloy showed lower dissolution rate.

Titanium and titanium alloys are widely used for orthopedic and dental implants for their superior mechanical properties, low modulus, excellent corrosion resistance and good biocompatibility. In this study, corrosion behaviors of nanotube formed on the bone plate of Ti-6Al-4V alloy for dental use have been investigated. nanotubes were formed on the dental bone plates by anodization in containing 0.6 wt % NaF solution at . Electrochemical experiments were performed using a conventional three-electrode configuration with a platinum counter electrode and a saturated calomel reference electrode. Anodization was carried out using a scanning potentiostat (EG&G Co, Model 263A USA), and all experiments were conducted at room temperature. The surface morphology was observed using field emission scanning electron microscopy (FE-SEM) and energy dispersive x-ray spectroscopy(EDS). The corrosion behavior of the dental bone plates was examined using potentiodynamic test(potential range of -1500~2000 mV) in a 0.9% NaCl solution by potentiostat (EG&G Co, PARSTAT 2273. USA). The inner diameter of nanotube was about 150~180 nm with wall thickness of about 20 nm. The interspace of nanotube to nanotube was 50 nm. The passive region of the nanotube formed bone plates showed the broad range compared to non-nanotube formed bone plates. The corrosion surface of sample was covered with corrosion products.

Correction for ‘A selectively processible instant glue passivation layer for indium gallium zinc oxide thin-film transistors fabricated at low temperature’ by Hyukjoon Yoo et al., J. Mater. Chem. C, 2018, 6, 6187–6193.

Ti-Zr (10, 20, 30 and 40 wt%) alloys were prepared by arc melting, followed by homogenization for 24 hr at 1000 C in an argon atmosphere. The formation of oxide nanotubes was achieved by anodizing a Ti-Zr alloy in H3PO4 electrolytes containing small amounts of uoride ions at room temperature. Electrochemical experiments were carried out using a conventional three-electrode con guration with a platinum counter electrode and a saturated calomel reference electrode. The anodization treatments were carried out using a scanning potentiostat (EG&G Co., Model 362, USA). All the experiments were conducted at room temperature. The microstructures of the alloys were examined by using optical microscopy (OM), eld-emission scanning electron microscopy (FE-SEM) and X-ray di ractometry (XRD). A TiN coating was deposited on the anodized titaniumoxide layer by reactive RF magnetron sputtering using a Ti target (99.99 %). The corrosion properties of the specimens were examined using potentiodynamic tests (potential range of 150

Electrochemical behaviors of surface modified and MC3T3-E1 cell cultured Ti-30Ta alloys have been investigated using various electrochemical methods. The Ti alloys containing Ta were melted by using a vacuum furnace and then homogenized for 6 hrs at . MC3T3-E1 cell culture was performed with MC3T3-E1 mouse osteoblasts for 2 days. The microstructures and corrosion resistance were measured using FE-SEM, XRD, EIS and potentiodynamic test in artificial saliva solution at . Ti-Ta alloy showed the martensite structure of phase and micro-structure was changed from lamellar structure to needle-like structure as Ta content increased. Corrosion resistance increased as Ta content increased. Corrosion resistance of cell cultured Ti-Ta alloy increased predominantly in compared with non cell cultured Ti- Ta alloy due to inhibition of the dissolution of metal ion by covered cell. value of MC3T3-E1 cell cultured Ti-40 Ta alloy showed which was higher than those of other Ti alloy. Polarization resistance of cell-cultured Ti-Ta alloy increased in compared with non-cell cultured Ti alloy.

The volatile compounds of non-irradiated and 1, 3, 5, 10 and 20 kGy γ-irradiated roots of licorice (Glycyrrhiza uralensis Fischer) were isolated by simultaneous distillation–extraction (SDE) technique and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 61 volatile compounds belonging to the chemical classes of acid (2), alcohol (16), aldehyde (8), ester (6), furan (2), hydrocarbon (14), ketone (10) and N-containing compounds (3) were identified in non-irradiated licorice. The prime volatile compound of licorice was 2-ethoxy-1-propanol, which makes up to 22.82% of the total composition. Over a dose of 1 kGy, another compound, benzaldehyde appeared, whereas other compounds, 3,5-dimethyl octane and phenethyl alcohol, disappeared at the dose of 20 kGy. Though the content of several volatile compounds increased after γ-irradiation, the content of major volatile compounds such as 4-terpineol, myrtenal, tetramethylpyrazine, hexanoic acid, azulene and p-cymene decreased. In comparison to non-irradiated licorice, 10 kGy dose of irradiation induced the maximum level of total yield of volatile compounds by 12%, but slightly decreased at 20 kGy. Therefore, the application of γ-irradiation is feasible without major qualitative and quantitative loss of volatile compounds when exposed at 10 kGy.

Objectives: The purpose of this study was to analyze the incidence of indications for the removal of mini-plates over a five-year period in maxillofacial trauma patients. Materials and Methods: The medical records of 530 patients who underwent treatment with mini-plate fixation after maxillofacial trauma were reviewed for a five-year period (May 2007 to May 2012). Patients were evaluated concerning the number of mini-plates removed, age and gender distributions, time between insertion and removal, indication for removal, and site of removal. Results: The plates of 120 patients were removed (26 females and 94 males). The removal rate was 22.6%. The most frequent indication for removal was patient demand (81.7%), followed by tooth extraction (7.5%), and pain (3.3%). The most frequent removal site was the mandible (95.0%). Conclusion: The number of mini-plates removed was small, and the most common indication for removal was patient demand. There is no evidence to support a recommendation for the routine removal of titanium mini-plates.

Prunus choreiana, invalidly published without Latin description in the original text, is validated here. The species has been known as a Korean endemic plant species of deciduous shrub, and a typical calciferous plant mainly distributed in Pyeongnam Province and Hamnam Province, North Korea. However, recently new population was reported from Mt. Myon and another new population is reported here from Mt. Jabyeong in Gangwon-do.

Purpose: In advanced case of periodontitis, surgical treatment without bone contouring may result in residual pockets inaccessible to proper cleaning during post-treatment maintenance. This problem can be avoided or reduced by applying guided tissue regeneration. Materials and Methods: All of 3 patients had deep periodontal pocket depth and bleeding on probing, and radiograph revealed osseous defect, so we planned guided tissue regeneration using resorbable membrane with or without xenograft. Result: 6 months later, periodontal pocket depth and bleeding on probing was improved and gingiva was stable. Conclusion: Guided tissue regeneration using resorbable membrane with or without xenograft in osseous defect is predictable. (J Korean Acad Periodontol 2008;38:737-744)