We report a synthesis of non-toxic InP nanocrystals using non-pyrolytic precursors instead of pyrolytic and unstable tris(trimethylsilyl)phosphine, a popular precursor for synthesis of InP nanocrystals. In this study, InP nanocrystals are successfully synthesized using hexaethyl phosphorous triamide (HPT) and the synthesized InP nanocrystals showed a broad and weak photoluminescence (PL) spectrum. As synthesized InP nanocrystals are subjected to further surface modification process to enhance their stability and photoluminescence. Surface modification of InP nanocrystals is done at 230°C using 1-dodecanethiol, zinc acetate and fatty acid as sources of ZnS shell. After surface modification, the synthesized InP/ZnS nanocrystals show intense PL spectra centered at the emission wavelength 612 nm through 633 nm. The synthesized InP/ZnS core/shell structure is confirmed with X-ray diffraction (XRD) and Inductively Coupled Plasma - Atomic Emission Spectrometer (ICP-AES). After surface modification, InP/ZnS nanocrystals having narrow particle size distribution are observed by Field Emission Transmission Electron Microscope (FE-TEM). In contrast to uncapped InP nanocrystals, InP/ZnS nanocrystals treated with a newly developed surface modified procedure show highly enhanced PL spectra with quantum yield of 47%.

PURPOSES: It is difficult to estimate tunnel stability because of lack of timely information during tunnel excavation. Tunnel deformability refers to the capacity of rock to strain under applied loads or unloads during tunnel excavation. This study was conducted to analyze a methods of pre-evaluation of stability during tunnel construction using the critical strain concept, which is applied to the results of tunnel settlement data and unconfined compression strength of intact rock or rock mass at the tunnel construction site. METHODS: Based on the critical strain concept, the pre-evaluation of stability of a tunnel was performed in the Daegu region, at a tunnel through andesite and granite rock. The critical strain concept is a method of predicting tunnel behavior from tunnel crown settlement data using the critical strain chart that is obtained from the relationship between strain and the unconfined compression strength of intact rock in a laboratory. RESULTS: In a pre-evaluation of stability of a tunnel, only actually measured crown settlement data is plotted on the lower position of the critical strain chart, to be compared with the total displacement of crown settlement, including precedent settlement and displacement data from before the settlement measurement. However, both cases show almost the same tunnel behavior. In an evaluation using rock mass instead of intact rock, the data for the rock mass strength is plotted on the lower portion of the critical strain chart, as a way to compare to the data for intact rock strength. CONCLUSIONS : From the results of the pre-evaluation of stability of the tunnel using the critical strain chart, we reaffirmed that it is possible to promptly evaluate the stability of a tunnel under construction. Moreover, this research shows that a safety evaluation using the actual instrumented crown settlement data with the unconfined compression strength of intact rock, rather than with the unconfined compression strength of a rock mass in the tunnel working face, is more conservative.

본 연구에서는 마늘 특유의 매운 맛과 냄새를 억제하고 대표성분인 alliin을 보호하기 위해 코팅물질과 건조방법을 달리하여 미세캡슐화하였다. 코팅물질은 말토덱스트린(MD), 분리유청단백질(WPI), 전지분유(WMP), 탈지분유(SMP)로 하고 건조방법은 분무건조(spray-drying)방법과 동결건조 (freeze-drying)방법을 이용하여 캡슐화 후 코팅물질 별, 건 조방법 별 alliin 보호특성, 관능특성 그리고 분산성을 알아 보았다. 코팅물질을 증류수에 완전히 분산시키기 위해 24 시간 동안 교반한 후 동결건조 마늘분말을 천천히 첨가하 였다. 1:1 비율의 동결건조마늘분말과 코팅물질을 혼합한 용액을 균질기를 이용하여 균질화하고, 분무건조기 또는 동결건조기를 이용하여 코팅물질을 달리하여 분말화하였 다. 미세캡슐화된 마늘분말의 추출물을 HPLC로 alliin 함 량을 정량 분석하였다. HPLC 분석결과 전지분유를 코팅물 질로 하고 분무건조방법으로 캡슐화한 마늘분말의 alliin함 량이 4.131 mg/g으로 최대함량을 보였으며, 관능평가 결과 로서 코팅물질을 분리유청단백질로 하고 분무건조방법으로 캡슐화한 마늘분말이 매운 맛과 냄새를 억제하는데 효과적 이었다. 또한 혼탁도 측정을 통한 캡슐화된 마늘 분말의 분산성을 측정했을 때, 전지분유로 캡슐화한 마늘분말의 안정성이 가장 높음을 확인할 수 있었다. 코팅물질 중 유 지방과 단백질이 황화합물에서 발생하는 특유의 매운맛과 냄새를 억제해주며 alliin의 보호에도 기여함을 알 수 있었 다. 본 실험결과, 지표물질 보호특성, 이취개선 등의 기초 자료는 기능성 식품 산업에 있어서 마늘 소재 개발을 위한 기초자료가 될 수 있을 것이다.

Armor block is used to reduce wave energy. Concrete armor block is prone to be damaged under the ultimate load like typhoon. It is necessary to develop a new type of armor block to enhance to the strength. So, the research of new type armor block..

산소 분리를 위한 세라믹 중공사막을 상전이 방적기술을 통해 제조하였다. 초기 BSCF 선구물질은 고상반응법을 이용하여 합성한 상용 분말이며, 고분자 용액에 분산시킨 후 이중관형 노즐을 통해 사출하였다. 사출된 분리막은 상전이 과정을 거친 후 건조시켰으며 중공사막의 한쪽 끝을 밀봉하였다. 한쪽 끝이 막힌 중공사막의 표면에 dip coating 방법으로 LSCF를 코팅하였으며 1100 ℃에서 소결하여 치밀성을 갖는 한쪽 끝이 막힌 LSCF coated BSCF 중공사막을 제조하였다. 분리막의 공급측은 대기 중 공기를 사용하였으며 투과측은 진공상태를 유지하였다. 투과된 기체의 유량 및 산소의 농도를 측정하였으며 장기투과 실험과 EDS 분석을 통해 분리막의 안정성 평가를 진행하였다.

NiO catalysts/Al2O3/FeCrAl alloy foam for hydrogen production was prepared using atomic layer deposition (ALD)and subsequent dip-coating methods. FeCrAl alloy foam and Al2O3 inter-layer were used as catalyst supports. To improve thedispersion and stability of NiO catalysts, an Al2O3 inter-layer was introduced and their thickness was systematically controlledto 0, 20, 50 and 80nm using an ALD technique. The structural, chemical bonding and morphological properties (includingdispersion) of the NiO catalysts/Al2O3/FeCrAl alloy foam were characterized by X-ray diffraction, X-ray photoelectronspectroscopy, field-emission scanning electron microscopy and scanning electron microscopy-energy dispersive spectroscopy. Inparticular, to evaluate the stability of the NiO catalysts grown on Al2O3/FeCrAl alloy foam, chronoamperometry tests wereperformed and then the ingredient amounts of electrolytes were analyzed via inductively coupled plasma spectrometer. We foundthat the introduction of Al2O3 inter-layer improved the dispersion and stability of the NiO catalysts on the supports. Thus, whenan Al2O3 inter-layer with a 80nm thickness was grown between the FeCrAl alloy foam and the NiO catalysts, it indicatedimproved dispersion and stability of the NiO catalysts compared to the other samples. The performance improvement can beexplained by optimum thickness of Al2O3 inter-layer resulting from the role of a passivation layer.

In this study, a shape design and an analysis considering structural stability were investigated to develop an icosahedron-based hemispherical modular dome. To design this modular dome, a program that can perform icosahedron shape modeling, modularization of joint connection members, and the analysis of structural stability was developed. Furthermore, based on the adopted numerical model, the eigen buckling mode, unstable behavior characteristics according to load vector, and the critical buckling load of the modular dome under uniformly distributed load and concentrated load were analyzed, and the resistance capacities of the structure according to different load vectors were compared. The analysis results for the modular dome suggest that the developed program can perform joint modeling for shape design as well as modular member design, and adequately expressed the nonlinear behaviors of structured according to load conditions. The critical buckling load results also correctly reflected the characteristics of the load conditions. The uniformly distributed load was more advantageous to the structural stability than concentrated load.

목적: 원데이 토릭소프트콘택트렌즈의 디자인에 따른 축안정성과 렌즈 회전회복 정도, 그리고 자각적 만족도를 각각 조사하여 비교하고자 한다. 방법: 안질환 및 안과적 수술 경험이 없는 대학생 20명(37안)을 대상으로 A사 (Accelerated Stabilization design), B사 (Prism Ballast design), C사 (Peri-Prism Ballast design)의 서로 다른 디자인의 원데이 토릭소프트렌즈를 적응 전과 후의 축안정성과 렌즈회전회복 정도를 각 각 측정하였다. 축안정성은 제 1안위에서 측정하였고, 회전회복정도는 코쪽과 귀쪽으로 각각 30˚씩 회전 시킨 후 순목에 의해 회복되는 정도를 측정하였다. 적응 후 측정은 렌즈 착용 5일 후에 실시하였다. 자각적 만족도는 적응 전과 적응 후 설문조사(5점 척도)를 통해 조사하였으 며, 착용 시간대별로 자각적 만족도를 조사하였다. 결과: A사, B사, C사 모두 우안에서는 코쪽방향으로 좌안에서는 귀쪽방향으로 축회전을 보였 지만, 적응 전에 비해 적응 후 축안정성이 더 안정화 되었다. B사의 렌즈 디자인은 순목 후 빠 른 회전회복을 보였다. 착용 시간대별 자각적 만족도는 착용감, 건조감, 충혈도에서는 3사의 제품이 별차이가 없었지만, A사의 렌즈가 타사에 비해 선명도가 높은 것으로 조사되었다. 결론: 토릭소프트콘택트렌즈는 축안정성을 위해서 일정한 적응기간을 필요로하므로 토릭렌즈를 처방시 렌즈를 적응한 후 축안정성을 재확인할 필요가 있을 것으로 고려된다.

낙동강 상류에 설치된 수중보 2곳(St.1, St.2)과 본류에 설치된 낙단보(St.3) 및 상주보(St.4)의 저서성대형무척추동물 군집구조와 군집안정성을 분석하였다. 조사는 2014년 봄, 여름, 가을 총 3회 수질조사와 병행하여 실시하였다. 분류군별 출현현황은 소형 수중보(St.1, St.2)와 대형 보(St.3, St.4)에서 각각 총 11목 32종, 14목 52종, 13목 34종, 9목 18종이 출현하였다. 군집지수 분석결과, 평균 다양도지수(Hˊ)와 풍부도지수(Rˊ)는 St.2에서 각각 2.65와 2.54로 가장 높았으며, 평균 우점도지수(DI)는 St.4(0.84)에서 가장 높게 나타났다. 섭식기능군(FFG) 분석결과, P(Predator)와 GC(Gathering Collector)의 종수 점유율은 대형보에서 88.0%~90.0%, 수중보에서 64.3%~83.3%로 나타났다. 서식기능군(FHG) 분석결과, 비교적 유수역을 선호하는 종으로 구성된 CL(Clinger)의 점유율이 소형 수중보에서는 32.3%~48.4%로 대형보의 9.7%~25.8% 보다 더 높게 나타났다. 군집안정성 분석결과, 대형 보에서 I 그룹(저항력↑, 회복력↑)과 III 그룹(저항력↓, 회복력↓)에 속하는 종들이 수중보에 비해 각각 더 높은 점유율(75.0% > 70.0%, 16.7% > 14.0%)을 나타냈다. 이화학적 수질요인과의 상관관계를 분석한 결과, 종수 및 개체수는 물리적 환경요인인 pebble입자와 양의 상관성(p<0.05)을 나타냈다. 또한 전기전도도, COD가 종수, 그리고 DO가 개체수와 음의 상관성(p<0.05)을 나타냈다.

In this study, structural stability of large diameter high density polyethylene (HDPE) pipe during installation was numerically investigated in order to investigate the effect of concrete collar dimension, water depth and tension (pulling force). From the numerical simulation results, the total stress of HDPE pipe with designed concrete collar was within 2.5%, so the total weight of concrete collar for sinking of HDPE is important rather than concrete collar dimension. Furthermore, the tension area for possible installation is decreased as the air filling rate is increased. Therefore, it is important to calculate the reasonable tension range before actual installation for safe installation of HDPE pipe.

The worldwide abundance of various jellyfish appears to have increased in coastal ecosystems in recent years. The enormous jellyfish blooms cause a variety of problems for the local ecology, fisheries, and aquatic-sports in coastal locations. In this study, jellyfish sting protection net was installed to ensure the safety and reduction of the inflow into the Haeundae beach. In order to confirm the stability of the protection net, the tension for protection net was measured from variation of current speed. The periods for maximum tension were observed correspond to the periods of maximum current speed. The maximum tension for protection net was measured up to 4,100 kg. From field evaluations, the jellyfish sting protection net has demonstrated to stability from the current and tide in the Haeundae beach.

The purpose of this study is to analyze the structural stability of pavement due to water infiltration at the road with infiltration trench as using the FEM(finite element analysis). Five cases for FEM is divided considering the amount of rainfall and rain duration time. The results of FEM show that the more rainfall in a short period time is faster the change of moisture content. Also, it is the proportional relationship between and changing area of moisture content of more than 40% due to rainfall. Case 3 and 4 are necessary to check the installation of infiltration trench because of moisture content of more than 40%, recovery time of initial moisture content, and changing area of more than 40%. Case 1,2, and 5 have no a significant effect on road pavement structure due to lower moisture content and shorter duration time of higher moisture content.

탄성지반위에 놓인 S형상 점진기능재료 고차전단변형 판의 동적 불안정성에 대하여 연구하였다. 고차전단변형이론은 점진기능재료 판의 두께방향으로의 전단변형률과 전단응력의 곡선변화 효과를 고려할 수 있다. Mathieu-Hill 방정식의 형태로 유도된 지배방정식에서 Bolotin 방법을 이용하여 동적 불안정 영역을 결정하였다. 동적 불안정 영역의 경계는 동적 하중과 여기진동수와의 관계로 나타내었다. 고차전단변형이론과 탄성지반 효과가 S형상 점진기능재료 판의 동적 불안정성에 미치는 효과를 제시하였다. Winkler와 Pasternak탄성지반 매개변수의 관계를 수치해석 결과를 통하여 고찰하였다. 또한 정적 하중계수, 거듭제곱 지수 그리고 폭-두께비 등의 동적 불안정 영역에 대한 영향을 분석하였다. 본 연구의 결과를 검증하기 위해 참고문헌의 결과와 비교 분석하였다. 본 연구에서 제시한 이론적 발전과 수치결과들은 S형상 점진기능재료 구조물의 동적 불안정 해석을 위한 참고자료로 활용될 수 있을 것이다.

This study aimed to investigate the effect of the abdominal drawing-in maneuver (ADIM) and abdominal expansion maneuver (AEM) on trunk stabilization, as well as trunk muscle activities and differences in quadruple visual analogue scale, Korean Oswestry Disability Index, and Fear Avoidance Beliefs Questionnaire scores, in patients with chronic low back pain and lumbar spine instability. To increase intra-abdominal pressure during the trunk stabilization exercise, the technique of pushing the abdomen out using diaphragmatic abdominal breathing suggested by Pavel Koral was used, which we termed the AEM. Fifty patients who tested positive on more than three of the five lumbar spine instability tests were separated from 138 patients with chronic low back pain of these patients, 16 were placed in the control group (trunk stabilization exercise), 17 were placed in the ADIM group (trunk stabilization exercise with ADIM), and 17 were placed in the AEM group (trunk stabilization exercise with AEM). Each group participated in the study for 30 minutes three times weekly for 4 weeks. Surface electromyography was used to measure the trunk muscle activities during the kneeling forward and supine bridging positions, and one-way repeated analysis of variance was used to determine the statistical significance of the trunk muscle activities in the rectus abdominis, internal oblique (IO), erector spinae, and multifidus (MF) muscles. The ADIM and AEM groups showed relatively larger improvements in psychosocial and functional disability level than control group. There were significant changes among the three groups, those from the measured values of the AEM group was significantly higher than the other two groups in changes in IO and MF trunk muscle activities (p＜05). This finding demonstrates that trunk stabilization exercises with AEM is more effective than ADIM for increasing trunk deep muscle activity of chronic low back pain patients with lumbar spine instability.

The blending schemes of Saengshik powder with water were established to retain the dispersion stability of the Saengshik beverage in order to develop a ready-to-drink type product. The effect of the blending on the rheological properties and the dispersion stability of Saengshik beverage were determined. The Saengshik beverages, blended with low shear force for a short time, showed dilatant fluid characteristics, while those with high shear force for a long time had pseudoplastic fluid ones. The consistency of Saengshik beverage increased with the blending speed and time. Saengshik beverage blended at low shear showed rheopexy while becoming time independent by a highshear blending action. A logarithmic model fitted well to the changes in backscattering light flux with the rest time of Saengshik beverage. Based on sedimentation kinetics, the migration speed of clear front, and the thickness of sedimented layer, Saengshik beverage with maximum dispersion stability was obtained by a high shear blending at 15,120 rpm for 25 s.

This study aimed to investigate the changes in antioxidant activities, quality characteristics, and storage stability of mayonnaise prepared with perilla oil with the addition of mulberry powder ranging from 0 to 5%. The antioxidant activities of perilla oil mayonnaise (PM), as determined by DPPH and ABTS radical scavenging activity, as well as FRAP and total phenolics content were improved by the addition of mulberry powder compared with the control sample. Antioxidant activities were dependent on the amount of mulberry powder added. Lipid oxidation of PM decreased with a higher amount of mulberry powder, based on measurements of peroxide value. The emulsion stability of PM increased with decreases in the amount of mulberry powder level. The a-value in PM color increased with increasing amount of mulberry powder. Sensory evaluation showed that the highest score in overall acceptability of PM was achieved with 4% mulberry.