Damping and sound absorption not only reduce environmental pollution caused by vibration and noise, but also improves processing accuracy, resolution of precision measuring instruments and fatigue life of machine parts in various precision machines. The vibration-damping plate is largely divided into a constrained type in which the resin is confined by a plate and a non-constrained type in which a plate is made of a polymer material mainly composed of polymer. The external vibration energy is absorbed by the thermal energy required for friction, stretching and compression of resin, so that the noise and vibration generated by resonance are reduced. The vibration damping ability of the sandwich plate produced in this study was found to be somewhat superior, which may be due to the difference in adhesive force during the manufacture of the sandwich plate. In the experimental results, it was confirmed that the sandwich plate material is superior to the vibration damping ability than the 5182 aluminum single plate material, it can be seen that the sandwich plate is effective for vibration damping of the aluminum alloy plate material.

Zn-ion supercapacitors (ZICs) show high energy densities with long cycling life for use in electronic devices. Porous Zn electrodes as anodes for ZICs are fabricated by chemical etching process using optimized conditions. The structures, morphologies, chemical bonding states, porous structure, and electrochemical behavior are examined. The optimized porous Zn electrode shows a root mean square of roughness of 173 nm and high surface area of 153 μm2. As a result, ZIC using the optimized porous Zn electrode presents excellent electrochemical performance with high specific capacitance of 399 F g−1 at current density of 0.5 A g−1, high-rate performance (79 F g−1 at a current density of 10.0 A g−1), and outstanding cycling stability (99 % after 1,500 cycles). The development of energy storage performance using synergistic effects of high roughness and high surface area is due to increased electroactive sites by surface functionalization of Zn electrode. Thus, our strategy will lead to a rational design and contribute to next-generation supercapacitors in the near future.

여러 규모의 가정간편식 제조업체를 대상으로 설문조사를 통해 업체의 식품안전문화를 수행 정도와 각 업체들이 식품안전문화 요소들에 대해 인식하는 중요도를 조사 하고, 식품안전문화 측정요소들이 HACCP 선행요건프로그램을 수행하는데 미치는 영향 수준을 분석하였다. 식품 안전문화의 측정은 기업문화, 경영진의 의지, 교육·훈련 및 종업원의 참여 등 식품안전문화의 5개 요소를 지표로 평가하였다. 식품안전문화 요소가 HACCP 선행요건프로그램의 수행도에 미치는 영향은 로지스틱 회귀 분석을 실시하여 분석하였다. 식품안전문화 요소의 수행도는 기업문화, 종업원의 참여 부분에서는 업체 규모에 따른 유의적 차이가 나타나지 않았으나(p>0.05) 경영진의 의지, 자원의 투입, 교육·훈련의 경우 대규모업체에서 유의적으로(p<0.05) 높았다. 한편 기업의 문화는 대규모업체에서는 중요도가 높다고 인식하고 있었으나 소규모업체에서 중요성에 대한 인식도가 매우 낮아 업체 규모에 따른 인식도의 불균형을 보여주었다. 식품안전문화 요소들이 기업의 HACCP 선행 요건프로그램의 수행도에 미치는 영향을 조사한 결과 ‘종업원의 교육·훈련’이 HACCP 수행도에 통계적으로 유의하게(p=0.043) 영향을 미치는 식품안전문화 요소로 나타나 HACCP 내실을 기하기 위해서는 종업원들에 대한 교육· 훈련이 매우 중요함을 시사하였다.

To meet the current demand in the fields of permanent magnets for achieving a high energy density, it is imperative to prepare nano-to-microscale rare-earth-based magnets with well-defined microstructures, controlled homogeneity, and magnetic characteristics via a bottom-up approach. Here, on the basis of a microstructural study and qualitative magnetic measurements, optimized reduction conditions for the preparation of nanostructured Sm-Co magnets are proposed, and the elucidation of the reduction-diffusion behavior in the binary phase system is clearly manifested. In addition, we have investigated the microstructural, crystallographic, and magnetic properties of the Sm-Co magnets prepared under different reduction conditions, that is, H2 gas, calcium, and calcium hydride. This work provides a potential approach to prepare high-quality Sm-Co-based nanofibers, and moreover, it can be extended to the experimental design of other magnetic alloys.

This study examines the changes in chlorogenic acid (CGA), an antioxidant, and one of its decomposition substances, caffeic acid, at various roasting stages and extraction conditions. Based on the CGA content for each roasting stage, at 3℃ after the beginning of the 1st crack, the CGA decreased for washed beans and natural beans by more than 50% compared to that of green coffees. The CGA continued to decrease sharply by more than 75% at the end of the 1st crack for washed beans and at 5℃ after the end of the 1st crack for natural beans. At the peak of the 2nd crack, it had decreased by more than 90% for both beans. The Caffeic acid content gradually increased for both washed and natural beans, then rapidly increased from the beginning of the 2nd crack to the peak of the 2nd crack. However, its contents were very small in quantity. Additionally, the content of CGAs for differing extraction conditions were in the order of 3-CGA, Crypto-CGA, and Neo-CGA. Crypto-CGA content was about half that of 3-CGA and Neo-CGA content was approximately 100 ppm less than that of Crypto-CGA. This study was conducted in order to help make coffee that has the most antioxidant effect.

Nb-Si-B alloys with Nb-rich compositions are fabricated by spark plasma sintering for high-temperature structural applications. Three compositions are selected: 75 at% Nb (Nb0.7), 82 at% Nb (Nb1.5), and 88 at% Nb (Nb3), the atomic ratio of Si to B being 2. The microstructures of the prepared alloys are composed of Nb and T2 phases. The T2 phase is an intermetallic compound with a stoichiometry of Nb5Si3-xBx (0 ≤ x ≤ 2). In some previous studies, Nb-Si- B alloys have been prepared by spark plasma sintering (SPS) using Nb and T2 powders (SPS 1). In the present work, the same alloys are prepared by the SPS process (SPS 2) using Nb powders and hypereutectic alloy powders with composition 67at%Nb-22at%Si-11at%B (Nb67). The Nb67 alloy powders comprise T2 and eutectic (T2 + Nb) phases. The microstructures and hardness of the samples prepared in the present work have been compared with those previously reported; the samples prepared in this study exhibit finer and more uniform microstructures and higher hardness.

TiO2-particles containing Co grains are fabricated via thermal hydrogenation and selective oxidation of Ti- Co alloy. For comparison, TiO2-Co composite powders are prepared by two kinds of methods which were the mechanical carbonization and oxidation process, and the conventional mixing process. The microstructural characteristics of the prepared composites are analyzed by X-ray diffraction, field-emission scattering electron microscopy, and transmission electron microscopy. In addition, the composite powders are sintered at 800℃ by spark plasma sintering. The flexural strength and fracture toughness of the sintered samples prepared by thermal hydrogenation and mechanical carbonization are found to be higher than those of the samples prepared by the conventional mixing process. Moreover, the microstructures of sintered samples prepared by thermal hydrogenation and mechanical carbonization processes are found to be similar. The difference in the mechanical properties of sintered samples prepared by thermal hydrogenation and mechanical carbonization processes is attributed to the different sizes of metallic Co particles in the samples.

Ti has received considerable attention for aerospace, vehicle, and semiconductor industry applications because of its acid-resistant nature, low density, and high mechanical strength. A common precursor used for preparing Ti materials is TiCl4. To prepare high-purity TiCl4, a process based on the removal of VOCl3 has been widely applied. However, VOCl3 removal by distillation and condensation is difficult because of the similar physical properties of TiCl4 and VOCl3. To circumvent this problem, in this study, we have developed a process for VOCl3 removal using Cu powder and mineral oil as purifying agents. The effects of reaction time and temperature, and ratio of purifying agents on the VOCl3 removal efficiency are investigated by chemical and structural measurements. Clear TiCl4 is obtained after the removal of VOCl3. Notably, complete removal of VOCl3 is achieved with 2.0 wt% of mineral oil. Moreover, the refined TiCl4 is used as a precursor for the synthesis of Ti powder. Ti powder is fabricated by a thermal reduction process at 1,100oC using an H2-Ar gas mixture. The average size of the Ti powder particles is in the range of 1-3 μm.

본 연구에서는 보습오일 및 천연유화제를 포함한 하이드로젤 비드 및 고강도 하이드로젤 매트릭스로 구성된 알지네이트 기반의 하이드로젤 멤브레인을 제조하고 용출 특성을 평가하였다. 실험 결과, 하이드로젤 비드 및 고강도 하이드로젤 의 조성을 조절하여 보습오일 성분의 용출 속도를 원하는 범위로 제어할 수 있음을 확인하였다. 특히 상호 침투 고분자 네트워크 구조를 가지고 있는 고강도 하이드로젤과 하이드로젤 비드를 결합함으로써 멤브레인의 물리적 안정성을 높이고 동시에 보습오일의 용출 속도를 더욱 세밀하게 제어할 수 있음을 확인하였다.

본 논문에서는 이산화탄소 친화적인 PBEM-POEM (PBE) 공중합체를 기반으로 고분자 블렌드 분리막을 제조하 는 방법을 제시한다. PBE 공중합체는 자유 라디칼 중합 반응을 통해 손쉽게 합성이 가능하며, 이를 상용 고분자인 PEG와 다 양한 비율로 혼합하여 이산화탄소/질소 분리막을 제조하였다. 이산화탄소/질소 분리 성능을 테스트한 결과, PEG의 함량이 높을수록 이산화탄소 투과도는 감소하는 반면 이산화탄소/질소 선택도는 크게 증가하는 상충(trade-off) 관계가 나타났다. 그러 나 PBE/PEG (9 : 1)과 PBE/PEG (7 : 3)을 비교하면 이산화탄소 투과도는 단지 8.3% 감소한 반면에 질소 투과도는 69.1%나 감소하였다. 따라서 이산화탄소/질소 선택도가 33.8에서 100.3으로 크게 증가하였다. 이것은 PBE 공중합체의 80%를 차지하 는 POEM 사슬이 PEG와 상호작용하여 더욱 조밀한 구조가 되었기 때문이며, 이를 FT-IR, XRD, SEM 분석으로 확인하였다. PBE/PEG (7 : 3) 블렌드 막이 가장 최적의 기체 분리 성능을 가졌고, 이산화탄소투과도는 170.5 GPU, 이산화탄소/질소 선택 도는 100.3이었다.

다시마를 첨가한 건어묵 면의 수분함량의 평균값은 3.71±0.12%이었으며 수분활성도는 0.185-0.332로 다시마 분말함유량이 증가할수록 수분활성도가 낮아졌다. 재수화도는 다시마 분말함유량이 3%와 5%일 때, 각각 1.49, 1.77 g water/g solid로 대조군에 비해 증가하였다. 색도 측정결과 녹색계열의 다시마 분말함유량이 증가할수록 명도, 적색도 및 황색도 값이 낮아지는 결과를 볼 수 있었다. TPA를 이용한 조직감분석에서는 다시마 분말의 함유량이 증가할수록 탄력성은 증가하였고 경도와 씹힘성이 낮아졌다. 관능검사 결과로 5% 다시마 분말을 첨가한 어묵 면이 조직감, 맛, 전체적인 기호도 평가에서 가장 높게 나타났으며 면발의 단단함에 대한 강도에서는 다시마 분말의 함량이 많아질수록 낮은 결과를 나타내었다.

본 연구는 팽화스낵에 기능성 및 영양적으로 뛰어난 인삼의 활용도를 높이고자 각 조건별로 팽화스낵을 제조해 품질특성을 조사하였다. 수분함량(1, 4, 7, 10%)을 달리하여 pellet을 제조하고, 백미와 혼합한 뒤 팽화온도(180-220℃)를 달리하여 스낵을 제조하였다. 팽화스낵 제조 시, pellet의 수분함량과 팽화온도가 낮을수록 팽화가 잘 일어나지 않아 딱딱한 질감과 온전하지 않은 모양으로 제조되었다. 색도에서는 pellet의 수분함량과 팽화온도가 높을수록 명도, 적색도, 비체적은 증가하는 경향을 나타내었지만, 조직감에서는 감소하였다. 이에 따라 인삼을 이용한 팽화스낵 제조 시에는 적절한 수분함량과 팽화온도가 필요할 것으로 생각된다.

본 연구는 국내에 진출해 있는 외국인투자기업 본사의 경영자 파견여부가 해외자회사의 성과에 미치는 영향에 대해 관찰하였다. 이에 더하여 연구개발 활동 수준, 기업 규모, 합작설립 여부와 같은 자회사 수준 변수들의 조절 효과를 규명해 보고자 하였다. 다국적 해외진출기업 총람을 통하여 획득한 338개의 외국인투자기업을 표본으로 2011년부터 2015년까지의 5개년도 패널자료를 분석한 본 연구의 실증 결과는 다음과 같다. 첫째, 국내진출 외 국인투자기업의 최고경영자가 본사에서 파견한 외국인일 경우 성과에 긍정적인 영향을 미치는 것을 확인하였다. 둘째, 외국인투자기업 해외 자회사의 연구개발 활동이 활발할수록 본사에서 파견된 최고경영자가 해외자회사의 성과에 미치는 영향력이 강화되는 것으로 나타났다.

The Industrial Innovation Movement, based on win-win cooperation with SMEs, is a structure that enables suppliers who have struggled with corporate growth through productivity innovation due to poor manufacturing environment and lack of innovation. To this end, consultants and technical experts will support production innovation activities to improve production methods and improve productivity through process and management consulting. The purpose of this study was to explore the driving factors of the industrial innovation movement to improve the corporate ecosystem by improving the productivity of SMEs using modified IPA. The research results are as follows. First, in order to revitalize the Industrial Innovation Movement, the CEO-related elements of the participating companies should be maintained and strengthened. The motivation, education support, innovation organizational culture, the establishment of an innovation promotion system requires centralization of efforts for improvement. Second, in order to revitalize the Industrial Innovation Movement, the consultant's ability to analyze problems and suggest alternatives should be continuously strengthened. Third, in terms of the Central Promotion Headquarters, it was found that the Industrial Innovation Movement would be successful if the public information, industrial inspection for benchmarking, and provision of various information to support innovation activities were urgently improved.

본 연구에서는 가죽 스킨층에 코팅용으로 사용할 수용성 폴리우레탄의 합성을 위해 polyrupopylene mono methyl ether (PM)를 기반으로 폴리 에테르 폴리올인 폴리 프로필렌 글리콜과 이소포론 디 이소시아네이트 (isophorone diisocyanate, IPDI)를 합성 하였다. 예비 중합체의 합성 후, 점도 상승을 억제하기 위해 40 ℃에서 1M, 2M, 3M 및 4M으로 PM을 첨가하고 중화 반응 및 사슬 연장 반응을 수행하여 폴리 우레탄 시료를 준비 하였다. 준비된 시료의 인장강도와 연신율, 접착강도를 측정한 결과로 인장강도는 PM 이 1M 일 때2.109 kgf/mm2, 4M 에서 1.721kgf/mm2, 연신율은 PM이 1M일 때 496%, 4M 에서 522%, 접착력은 PM 이 1M 일 때 1.114 kgf/cm, 4M 에서 0.99 kgf/cm 로 확인 되었다.

A cold roll-bonding process is applied to fabricate an AA6061/AA5052/AA6061 three-layer clad sheet. Two AA6061 and one AA5052 sheets of 2 mm thickness, 40 mm width, and 300 mm length are stacked, with the AA5052 sheet located in the center. After surface treatment such as degreasing and wire brushing, sample is reduced to a thickness of 1.5 mm by multi-pass cold rolling. The rolling is performed at ambient temperature without lubricant using a 2-high mill with a roll diameter of 400 mm at rolling speed of 6.0 m/sec. The roll bonded AA6061/AA5052/AA6061 complex sheet is then hardened by natural aging(T4) and artificial aging(T6) treatments. The microstructures of the as-roll bonded and age-hardened Al complex sheets are revealed by optical microscopy; the mechanical properties are investigated by tensile testing and hardness testing. After rolling, the roll-bonded AA6061/AA5052/AA6061 sheets show a typical deformation structure in which grains are elongated in the rolling direction. However, after T4 and T6 aging treatment, there is a recrystallization structure consisting of coarse equiaxed grains in both AA5052 and AA6061 sheets. The as roll-bonded specimen shows a sandwich structure in which an AA5052 sheet is inserted into two AA6061 sheets with higher hardness. However, after T4 and T6 aging treatment, there is a different sandwich structure in which the hardness of the upper and lower layers of the AA6061 sheets is higher than that of the center of the AA5052 sheet. The strength values of the T4 and T6 age-treated specimens are found to increase by 1.3 and 1.4 times, respectively, compared to that value of the starting material.

This study deals with the microstructure and tensile properties of 600 MPa-grade seismic reinforced steel bars fabricated by a pilot plant. The steel bar specimens are composed of a fully ferrite-pearlite structure because they were air-cooled after hot-rolling. The volume fraction and interlamellar spacing of the pearlite and the ferrite grain size decrease from the center region to the surface region because the surface region is more rapidly cooled than the center region. The A steel bar specimenwith a relatively high carbon content generally has a higher pearlite volume fraction and interlamellar spacing of pearlite and a finer ferrite grain size because increasing the carbon content promotes the formation of pearlite. As a result, the A steel bar specimen has a higher hardness than the B steel bar in all the regions. The hardness shows a tendency to decrease from the center region to the surface region due to the decreased pearlite volume fraction. On the other hand, the tensile-to-yield strength ratio and the tensile strength of the A steel bar specimen are higher than those of the B steel bar with a relatively low carbon content because a higher pearlite volume fraction enhances work hardening. In addition, the B steel bar specimen has higher uniform and total elongations because a lower pearlite volume fraction facilitates plastic deformation caused by dislocation slip.

To develop Taraxacum platycarpum extract (TP)-loaded particles for tablet dosage form, various TP-loaded particles composed of TP, dextrin, microcrystalline cellulose (MCC), silicon dioxide, ethanol, and water are prepared using a spray-drying method and fluid-bed-drying method. Their physical properties are evaluated using angle of repose, Hausner ratio, Carr’s index, hardness, disintegrant time, and scanning electron microscopy. Optimal TP-loaded particles improve flowability and compressibility. Furthermore, 2% silicon dioxide gives increased flowability and compressibility. The formula of TP-loaded fluid-bed-drying particles at a TP/MCC/silicon-dioxide amount of 5/5/0.2 improves the angle of repose, Hausner ratio, Carr’s index, hardness, and disintegrant time as compared with the TP-loaded spray-drying particles. The TP-loaded fluid-bed-drying particles considerably improve flowability and compressibility (35.10° vs. 40.3°, 0.97 vs. 1.17, and 18.97% vs. 28.97% for the angle of repose, Hausner ratio, and Carr’s index, respectively), hardness (11.34 vs. 4.7 KP), and disintegrant time (7.4 vs. 10.4 min) as compared with the TP-loaded spray-drying particles. Thus, the results suggest that these fluid-bed-drying particles with MCC and silicon dioxide can be used as powerful particles to improve the flowability and compressibility of the TP.

The aluminum (Al)/copper oxide (CuO) complex is known as the most promising material for thermite reactions, releasing a high heat and pressure through ignition or thermal heating. To improve the reaction rate and wettability for handling safety, nanosized primary particles are applied on Al/CuO composite for energetic materials in explosives or propellants. Herein, graphene oxide (GO) is adopted for the Al/CuO composites as the functional supporting materials, preventing a phase-separation between solvent and composites, leading to a significantly enhanced reactivity. The characterizations of Al/CuO decorated on GO(Al/CuO/GO) are performed through scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy mapping analysis. Moreover, the functional bridging between Al/CuO and GO is suggested by identifying the chemical bonding with GO in X-ray photoelectron spectroscopy analysis. The reactivity of Al/CuO/GO composites is evaluated by comparing the maximum pressure and rate of the pressure increase of Al/CuO and Al/CuO/GO. The composites with a specific concentration of GO (10 wt%) demonstrate a well-dispersed mixture in hexane solution without phase separation.