Diamond/SiC composites were prepared by vacuum silica vapor-phase infiltration of in situ silicon–carbon reaction, and the thermophysical properties of the composites were modulated by controlling diamond graphitizing. The effects of diamond surface state and vacuum silicon infiltration temperature on diamond graphitization were investigated, and the micromorphology, phase composition, and properties of the composites were observed and characterized. The results show that diamond pretreatment can reduce the probability of graphitizing; when the penetration temperature is greater than 1600 °C, the diamond undergoes a graphitizing phase transition and the micro-morphology presents a lamellar shape. The thermal conductivity, density, and flexural strength of the composites increased and then decreased with the increase of penetration temperature in the experimentally designed range of penetration temperature. The variation of thermal expansion coefficients of composites prepared with different penetration temperatures ranged from 0.8 to 3.0 ppm/K when the temperature was between 50 and 400 °C.

최근 급부상한 생성형 AI는 현실적인 이미지, 텍스트, 음악 및 가상 환경 등을 만들어내는 능력 에 기반하여 엔터테인먼트, 디자인, 의료 및 교육 분야 등 다양한 산업 분야에 근본적인 변화를 가 져올 혁신 동력으로서 주목받고 있다. 오픈AI 등을 중심으로 한 글로벌 빅테크 기업들은 막강한 자 본력을 바탕으로 이 분야의 기술의 고도화와 함께 산업 생태계를 빠르게 구축하며 선도적인 지위를 굳히고 있어 한국의 생성형 AI 산업의 국가경쟁력 강화가 시급하다고 할 수 있다. 본 연구는 국가 경쟁력을 설명하는 Porter의 다이아몬드 모형에 기반해 한국의 생성형 AI 경쟁력에 영향을 미치는 다양한 요인들을 분석하여 한국의 생성형 AI 산업의 성장과 혁신을 육성하기 위한 기업의 전략적 방안과 정부의 정책적 방향성을 다음과 같이 제시하였다. 연구 결과 생성형 AI 관련 기업들의 투자 활동이 응용프로그램 개발을 우선시하고 있는 것으로 나타나 정부는 근본적인 기술 혁신 분야에 R&D 지원에 나서야 함을 알 수 있었다. 또한 기업 사용자들의 생성형 AI 수요가 제한적임에 따라 다양한 관련 교육 프로그램을 개발하고 맞춤 솔루션을 제공해야하며 개인 사용자들간의 디지털 격 차를 해소하는 정책적 노력이 필요하다는 것을 보여주었다. 생성형 AI 유관 산업 육성을 위해, 기 술경쟁력 강화와 인재 육성이 필요하고, 이와 더불어 생성형 AI 산업 에코시스템 내의 기업간 협력 을 촉진하기 위해 정부의 역할이 중요하다는 것을 확인할 수 있었다.

In this work, we have designed a novel gas inlet structure for efficient usage of growth and doping precursors. Our previous gas injection configuration is that the gas is mixed to one pipe first, then divided into two pipes, and finally entered the chamber symmetrically above the substrate without a jet nozzle. The distance between gas inlet and substrate is about 14.75 cm. Our new design is to add a new tube in the center of the susceptor, and the distance between the new tube and substrate is about 0.5 cm. In this new design, different gas injection configurations have been planned such that the gas flow in the reactor aids the transport of reaction species toward the sample surface, expecting the utilization efficiency of the precursors being improved in this method. Experiments have shown that a high doping efficiency and fast growth could be achieved concurrently in diamond growth when methane and diborane come from this new inlet, demonstrating a successful implementation of the design to a diamond microwave plasma chemical vapor deposition system. Compared to our previous gas injection configuration, the growth rate increases by 15-fold and the boron concentration increases by ~ 10 times. COMSOL simulation has shown that surface reaction and precursor supply both have a change in determining the growth rate and doping concentration. The current results could be further applied to other dopants for solving the low doping efficiency problems in ultra-wide-band-gap semiconductor materials.

We report a simple benchtop method to synthesize diamonds from ethyl alcohol ( C2H6O) at ambient pressure and room temperature via solvothermal reactions in a liquid solution of table salt (NaCl) and their structural characterization using electron diffraction and high-resolution electron microscopy. In addition to the usual cubic phase of diamond, the hexagonal phase of diamond (lonsdaleite) has also been obtained and identified unambiguously. Many of the synthesized diamonds often contain structural defects including twinnings, stacking faults, and dislocations. The formation and growth of diamond under ambient conditions provide further insights into understanding of the natural existence of diamond on Earth as well as in outer space. While only nanometric diamonds have been observed in the present study, we believe this discovery will open up new ways that have long been sought to grow diamonds, including large size diamonds, in organic solutions at ambient conditions.

Scanning probe microscopy (SPM) has become an indispensable tool in efforts to develop the next generation of nanoelectronic devices, given its achievable nanometer spatial resolution and highly versatile ability to measure a variety of properties. Recently a new scanning probe microscope was developed to overcome the tip degradation problem of the classic SPM. The main advantage of this new method, called Reverse tip sample (RTS) SPM, is that a single tip can be replaced by a chip containing hundreds to thousands of tips. Generally for use in RTS SPM, pyramid-shaped diamond tips are made by molding on a silicon substrate. Combining RTS SPM with Scanning spreading resistance microscopy (SSRM) using the diamond tip offers the potential to perform 3D profiling of semiconductor materials. However, damage frequently occurs to the completed tips because of the complex manufacturing process. In this work, we design, fabricate, and evaluate an RTS tip chip prototype to simplify the complex manufacturing process, prevent tip damage, and shorten manufacturing time.

High-quality diamond films have attracted extensive attentions due to their excellent optical and electrical properties. However, several issues, such as random orientation, stress accumulation, and slow growth rate, severely limit its applications. In this paper, high-quality polycrystalline diamond films with highly ordered (100) orientation were prepared by microwave plasma chemical vapor deposition. The effects of growth parameters on the microstructure, quality and residual stress of diamond films were investigated. Experimental results indicate that relatively high temperature at low methane concentration will promote the formation of (100) oriented grains with a low compressive stress. Optimized growth parameters, a methane concentration of 2% along with a pressure of 250 Torr and temperature at 1050 ℃, were used to acquire high growth rate of 7.9 μm/h and narrow full width at half maximum of Raman peak of 5.5 cm− 1 revealing a high crystal quality. It demonstrates a promising method for rapid growth of high-quality polycrystalline diamond films with (100) orientation, which is vital for improving the diamond related applications at low cost.

This study assessed the influences of fluorine introduced into DLC films on the structural and mechanical properties of the sample. In addition, the effects of the fluorine incorporation on the compressive stress in DLC films were investigated. For this purpose, fluorinated diamond-like carbon (F-DLC) films were deposited on cobalt-chromium-molybdenum substrates using radio-frequency plasma-enhanced chemical vapor. The coatings were examined by Raman scattering (RS), Attenuated total reflectance Fourier transform infrared spectroscopic analysis (ATR-FTIR), and a combination of elastic recoil detection analysis and Rutherford backscattering (ERDA-RBS). Nano-indentation tests were performed to measure hardness. Also, the residual stress of the films was calculated by the Stony equation. The ATR-FTIR analysis revealed that F was present in the amorphous matrix mainly as C-F and C-F2 groups. Based on Raman spectroscopy results, it was determined that F made the DLC films more graphitic. Additionally, it was shown that adding F into the DLC coating resulted in weaker mechanical properties and the F-DLC coating exhibited lower stress than DLC films. These effects were attributed to the replacement of strong C = C by feebler C-F bonds in the F-DLC films. F-doping decreased the hardness of the DLC from 11.5 to 8.8 GPa. In addition, with F addition, the compressive stress of the DLC sample decreased from 1 to 0.7 GPa.

This article reported a simple method for preparing diamond/SiC composites by polymer impregnation and pyrolysis (PIP) process, and the advantages of this method were discussed. Only diamond and SiC were contained in the diamond/SiC composite prepared by PIP process, and the diamond particles remained thermally stable up until the pyrolysis temperature was increased to 1600 °C. The pyrolysis temperature has a significant impact on the thermal conductivity and dielectric properties of composites. The thermal conductivity of the composite reaches a maximum value of 63.9 W/mK when the pyrolysis temperature is 1600 °C, and the minimum values of the real and imaginary part of the complex permittivity are 19.5 and 0.77, respectively. The PIP process is a quick and easy method to prepare diamond/SiC composites without needing expensive equipment, and it is of importance for promoting its application in the field of electric packaging substrate.

Heteroepitaxy is a better method of enlarging SCD wafer size than homoepitaxy. In this work, several aspects of the bias process for heteroepitaxial diamond nucleation are studied experimentally. First, with increasing bias time, the diamondnucleation pathway is found to transform from “isolated-crystal nucleation” to “typical domain-nucleation” and back to “isolated-crystal nucleation.” An interdependent relationship between bias voltage and bias time is proposed: the higher the bias voltage, the shorter the bias time. Second, a correlation exists between the threshold bias voltage and reactor-chamber pressure: a higher reactor chamber pressure usually requires a higher threshold bias voltage to realize “typical domain nucleation.” Third, diamond bias-enhanced nucleation and growth is observed at a high CH4 content, where the dynamic equilibrium between amorphous-carbon-layer deposition and atomic-hydrogen etching is broken. Finally, epitaxial nucleation is obtained on a substrate with ∅30 mm in a home-made MPCVD setup.

Individual multi-walled carbon nanotubes (MWCNTs) were exposed to the electron beam of 200 kV energy and high resolution transmission electron micrographs were recorded at several time intervals. Interestingly, the nucleation of diamond nanoparticles with in the highly disordered MWCNT matrix upon electron-irradiation is observed. This happens without any assistance of high pressures and temperatures. High pressure X-ray diffraction experiments were performed on core/shell structures which suggest that even the closed structures of carbon resist any inward pressure, thereby ruling out the possibility of a hypothetical internal pressure under the electron irradiation conditions. Our experiments suggest that the transformation of graphitic carbon into diamond in the size window of a few nanometers is possible due to the stability of the diamond and a selective dissolution effect of 200 kV electrons on graphite. A mechanism for the same is proposed.

Diamond reinforced silicon carbide matrix composites (diamond/SiC) with high thermal conductivity were prepared by tape casting combined with Si vapor infiltration for thermal management application. The effects of the mixing mode of bimodal diamond particles on the microstructure, thermal and mechanical properties of the composites were analyzed. The results reveal that the thermal conductivity of composites is affected significantly by mixing mode of diamond. In general, when the content of large diamond remains constant, adding a slight amount of small diamond was found to be effective in improving the thermal conductivity of the composite. However, excess small diamonds added will decrease thermal conductivity due to its high interfacial thermal resistance. The maximum thermal conductivity of obtained diamond/SiC is 469 W/(m K) when 38 vol% large diamond and 4 vol% small diamond were added. Such a result can be attributed to the formation of efficient heat transfer channels within the composite and sound interfacial bonding between diamond and SiC phase. Diamond/SiC with high thermal conductivity are expected to be the next generation of electronic packaging substrate.

본 연구의 목적은 비데를 아이템으로 선정해 시니어의 특성과 니즈를 충족시키기 위한 제품기반 서비스디자인을 제안하는데 목표를 두고 진행하였다. 최근 초고령화가 급속히 진행되고 있으나 시니어에 대한 이해가 부족하고, 시 니어를 위한 PSS 개념의 서비스디자인 연구가 미흡한 편이다. 본 연구에서는 4D 더블 다이아몬드 디자인 프로세스 모델을 활용하여 시니어의 특성과 니즈를 반영한 ‘시니어 중심의 비데 제품서비스디자인’ 개선방안을 제안하고자 한다. 연구의 방법은 PSS 개념에 기반하여 ‘4단계 더블 다이아몬드 디자인 프로세스 모델’을 활용하였다. 이를 위해 시니어 대상 질적 리서치를 수행하여 시니어의 특성과 니즈에 따른 사용자 가치 요소를 도출하였으며, 이를 기반으 로 제품서비스 아이디어를 발굴하여 실무 전문가 그룹의 유용성 리뷰를 반영한 프로토타입을 제안하였다. 연구의결과는 첫째, ‘사용자 맞춤 기능 설정 가이드 스마트 앱 서비스’를 제안하였다. 사물인터넷(IoT) 기술을 접목한 비데 와 스마트 폰이 연동되어 사용자 특성 정보와 비데 제품에 대한 정보를 자동으로 해석하여 맞춤 기능을 가이드해주 는 앱 서비스를 제시하였다. 둘째, ‘사용자 중심의 제품서비스 인터페이스’를 적용한 조작부 및 리모컨 UI를 제안하 였다. 시니어의 사용성 및 인지능력을 고려하여 주 기능 중심의 구성과 과업(Task) 순서에 따른 버튼 배치, 터치 화면 형 리모컨 등 단순하고 직관적인 Physical UI를 제안하였다. 셋째, 정기적인 제품 점검뿐만 아니라 사용자 건강 및 사용 공간의 위생, 청결 등 폭넓은 서비스를 제공하는 ‘제품과 헬스/위생 케어가 연계된 비데 케어서비스’를 제안하 였다. 결론적으로 사용자(시니어)의 비데 제품 사용 과정(사용 전-중-후)에서의 페인포인트(Pain Point) 및 요구를 발 견하고 개선하여 사용자 경험과 관계 품질을 향상시킬 수 있는 제품기반 서비스디자인 방법론을 제안하였다.

Diamond-like nanocomposite (DLN) has become a promising thin film for many fields of applications due to its unique and tunable properties. However, low optical bandgap and thermal stability limits its application in many fields particularly as antireflection coating on solar cell. In the present study, the DLN thin film has been deposited using a mixed liquid precursor by rf-PECVD process. Surprisingly the presence of nc-C60 in FCC structure in DLN matrix has been observed. The degree of crystallinity and diameter of C60 have been increased significantly after annealed at 850 °C. The film has been annealed at 850 °C to primarily investigate its feasibility as antireflection coating (ARC) in compatible with industrial solar cell fabrication process. The refractive index and optical bandgap of the film were around 1.80 and 4.10 eV, respectively. Moreover, the optical bandgap has decreased to some extent to 3.92 eV even after annealing at such high temperature. The high SiOx at% and embedded nc-C60 enhanced the optical transparency and thermal stability of the DLN film. The solar-weighted average reflection of DLN-coated textured silicon was reduced significantly to 1.91%. The C60 embedded DLN film has a great potential to apply in different optoelectronic devices especially in solar cell as ARC.

A 1.8 μm thick polycrystalline diamond (PCD) thin film layer is prepared on a Si(100) substrate using hot-filament chemical vapor deposition. Thereafter, its thermal conductivity is measured using the conventional laser flash analysis (LFA) method, a LaserPIT-M2 instrument, and the newly proposed light source thermal analysis (LSTA) method. The LSTA method measures the thermal conductivity of the prepared PCD thin film layer using an ultraviolet (UV) lamp with a wavelength of 395 nm as the heat source and a thermocouple installed at a specific distance. In addition, the microstructure and quality of the prepared PCD thin films are evaluated using an optical microscope, a field emission scanning electron microscope, and a micro-Raman spectroscope. The LFA, LaserPIT-M2, and LSTA determine the thermal conductivities of the PCD thin films, which are 1.7, 1430, and 213.43 W/(m·K), respectively, indicating that the LFA method and LaserPIT-M2 are prone to errors. Considering the grain size of PCD, we conclude that the LSTA method is the most reliable one for determining the thermal conductivity of the fabricated PCD thin film layers. Therefore, the proposed LSTA method presents significant potential for the accurate and reliable measurement of the thermal conductivity of PCD thin films.

This paper aims to use a critical discourse analysis (CDA) to analyze types of online news headlines about COVID-19 on cruise ship, the Diamond Princess, and to identify different traits between conservative newspapers and progressive ones. 480 articles were collected from five major news outlets in Korea: Chosun Ilbo, Joongang Ilbo, Donga Ilbo, Hankyoreh, and Kyunghyang Shinmun. The results show that the headlines tend to contain negative or extreme vocabulary and to employ quotes from experts or even from unknown sources in order to criticize Japan and blame the Japanese government for their way of dealing with the situation. In the case of differences between politically biased sources, it was found that the conservative media inclines toward framing negative images of the Japanese government by publishing more articles than the progressive media and by using numbers and statistics to clearly describe the surge of infected people on the ship. They also published more articles than the progressive media about Korea's actions to bring Koreans back home from the ship, framing positive images about the Korean government. As can be seen, the online news headlines are politically biased and manipulatively framed, so readers' discretion is necessary.

Background: The characteristics of lateral epicondylitis (LE) are muscle strength weakness and increased common extensor tendon (CET) thickness. Ultrasonography has recently been used to evaluate tendinopathy. Diamond taping (DT) is commonly used to manage patients with LE. However, no previous studies have investigated the effects of DT on CET thickness. Objects: The aim of this study was to investigate the effects of DT applied around the lateral elbow on CET thickness, grip strength, and wrist extension force in healthy subjects. Methods: The subjects were 26 adults (13 male) in their twenties. First, the CET thickness was measured at rest. The CET thickness was measured by using ultrasonography at two points. The subjects were then instructed to perform maximal grip activities or maximal wrist extension activities before and after DT around the lateral elbow. The DT technique was applied using non-elastic tape. While the subjects performed maximal grip activities, the investigator measured the maximum grip strength (MGS) and CET thickness. Likewise, while the subjects performed maximal wrist extension activities, the investigator measured the maximum wrist extension force (MWEF) and CET thickness. Results: The MGS showed a statistically significant improvement after DT taping application in men (p < 0.05). The MWEF showed a statistically significant improvement after DT application in male (p < 0.01) and female (p < 0.05). When performing the activities, the CET thickness increased compared to that at rest. However, CET thickness didn’t show a statistically significant improvement before and after DT. Conclusion: This study shows that DT applied around the lateral elbow is effective in improving MGS and MWEF. However, it does not affect CET thickness.

Background: Lateral epicondylitis (LE) is the most common chronic musculoskeletal pain condition of the upper extremities. LE is often related to forceful grip activities that require isometric contraction of the wrist extensors. A previous study evaluated the effect of the diamond taping technique on grip strength and pain; however, there has been no report on the change in the electromyography (EMG) findings of wrist extensors. Objects: The aim of this study was to investigate the effect of diamond taping technique, using a rigid tape, on the EMG activities of the extensor carpi radialis (ECR) during grip activities. Methods: Twenty-four healthy subjects (mean age = 21.50 ± 2.76 years) volunteered to participate in this study. The subjects were instructed to perform forceful grip activities with and without diamond-type taping on the origin area of the ECR. Grip strength tests were performed at 100%, 75%, 50%, and 25% for maximal isometric contraction force. EMG data were collected from the ECR. Repeated measure analysis of variance was used to analyze the effect of grip force and taping (with and without). Statistical significance levels were set at α = 0.05. Comparison of the results with and without taping at different grip force were analyzed using independent t-test. Statistical significance levels were set at α = 0.01. Results: Statistically significant association was observed between the taping application and forceful grip activity as revealed by the EMG data of the ECR (p < 0.05). EMG of the ECR significantly reduced for all muscle strength levels (p < 0.01) after taping. Conclusion: This study shows an impressive effect of the diamond taping technique, using rigid tape, on wrist extensors during grip activities. Decreasing muscle activity via this taping approach could be utilized to enhance pain-free grip force and reduce pain in patients with LE. Our study suggested that this taping technique could be considered as an effective management strategy of LE.

The results of gas chromatography–mass spectrometry (GC–MS) demonstrate that the volatiles captured by diamond grown by chemical vapour deposition (CVD) technology contain hydrocarbons and their derivatives (72.2 rel. %). We have identified aliphatic (paraffins and olefins), cyclic (naphthenes and arenes) and oxygenated (alcohols, aldehydes, ketones and carboxylic acids) hydrocarbons, as well as nitrogenated and sulfonated compounds. Water, negligible amounts of CO2 and Ar were also detected among the volatile components.