Underground cavities are frequently taking place in urban areas due to soil loss caused by structural defects of underground buried pipes. In this study, a field experimental program was conducted to detect ground condition using the electrical resistivity survey and the pneumatic cone penetration test. In addition, we proposed a method to estimate the weighted mean resistivity value by quantifying the electrical resistivity measurements through image analysis in order to compare the results of pneumatic cone penetration test. Consequently, it was found that as the weighted average resistivity value decreased, the smaller the N-value (penetration depth per blow number) from the pneumatic cone penetration test results. Based on the limited number of field experimental measurements, the correlation between weighted average resistivity value and the N-value of pneumatic cone penetration test is deemed promising in assessment of ground conditions associated with developing underground cavitation.

The objectives of this study were to characterize the physicochemical properties of ginger (Zingiber officinale Rosc.) and the optimum extract processing condition to increase the solubilization efficiency of 6-gingerol and polysaccharides disintegration. The physicochemical properties were investigated under high-pressure enzyme (HP) and enzyme (WB) treatment conditions such as reaction time (1, 2, 3 h), pressure (50, 70, 100 MPa) and sample types, and cell wall degradation enzyme (hemicellulase, cellulase, pectinase, glucosidase, etc.) The effect of high-pressure enzyme treatment depending on sample types was significantly highest in the freeze-dried ginger powder. The optimum condition for high-pressure enzyme treatment was with Pectinex Ultra SP-L (Pec) enzymes for 2 h at 50oC and 100 MPa. Water soluble indexes increased 4.6 and 3.8 times more compared to CON (15.35%) while total polyphenol contents increased by 1.8 and 1.7 times compared to CON (1.43%). The total contents of indicator components such as 6, 8, 10-gingerol and shogaol was 1.53%, increasing 2.7 times more compared to CON (0.57%) with a significant difference (p<0.001). The high-pressure and enzymatic approach described in this study would be beneficial to food industries for developing ginger functional product and materials.

The variations of internal temperature, relative humidity (RH) and gas concentration in the pallet modified atmosphere package (MAP), using polyamide (PA) film and linear low density polyethylene (LLDPE) film, were investigated to extend the shelf life of tomatoes and paprikas. The temperature and RH inside the MAP were higher than that in the cold room, but there was no water condensation inside the MA film. The ethylene concentration in the MAP was maintained below 10 ppm. Oxygen level was stabilized at 2 to 5% during the storage and carbon dioxide level was also stabilized at 15 to 20%. The weight loss of the MAP tomatoes and paprikas was lower than that of the control because the RH in the pallet MAP was higher than that of the cold room. The fungal decay rate in the pallet MAP was also lower than that in the control due to a low oxygen concentration rate. There were no significant differences in the soluble solids, titratable acidity and Hunter’s color, but differences did exist in the hardness between the MAP and the control. So, this pallet MAP method was effective at extending the shelf life of tomatoes and paprikas considering the weight loss, fungal decay and hardness.

As carbon material is being developed the versatile one with merits of metal, non-metal, ceramic and plastic etc., it owes to the characters of light weight and strength comparing with other metal materials. Based on these characters it is applied to vehicle lightening and aerospace industry. Furthermore thermal function utilization, removal of environmental pollution material, prevention of water pollution and the area of medicine science combining into drug as well. Therefore in this study we analyze technology paradigm home and abroad for carbon material on the basis of its relative patents and consider the establishment of technology strategy for its business commercialization

Background: It is very difficult for hemiplegic patients to effectively perform the sit-to-stand (STS) movements independently because of several factors. Moreover, the analysis of STS motion in hemiplegic patients has been thus far confined to only muscle strength evaluation with little information available on structural and environmental factors of varying chair height and foot conditions. Objects: This study aimed to analyze the change in biomechanical factors (ground reaction force, center of mass displacement, and the angle and moment of joints) of the joints in the lower extremities with varying chair height and foot conditions in hemiplegic patients while they performed the STS movements. Methods: Nine hemiplegic patients voluntarily participated in this study. Their STS movements was analyzed in a total of nine sessions (one set of three consecutive sessions) with varying chair height and foot conditions. The biomechanical factors of the joints in the lower extremities were measured during the movements. Ground reaction force was measured using a force plate; and the other abovementioned parameters were measured using an infra-red camera. Two-way repeated analysis of variance was performed to determine the changes in biomechanical factors in the lower extremities with varying chair height and foot conditions. Results: No interaction was found between chair height and foot conditions (p>.05). All measured variables with varying chair height showed a significant difference (p<.05). Maximum joint flexion angle, maximum joint moment, and the displacement of the center of mass in foot conditions showed a significant difference (p<.05); however the maximum ground reaction force did not show a significant difference (p>.05). Conclusion: The findings suggest that hemiplegic patients can more stably and efficiently perform the STS movement with increased chair height and while they are bare-foot.

For facilitated olefin/paraffin separation, poly(ethylene-alt-maleic anhydride)-g-O-(2-aminopropyl)-O′-(2-methoxyethyl) polypropylene glycol (PEMA-g-PPG) is reported by facile, cheap and moderate-condition synthesis. PEMA-g-PPG provided effective polymer matrix for partially polarized silver nanoparticles (AgNPs) and 7,7,8,8-tetracyanoquinodimethane (TCNQ). AgNPs could facilitate olefin transport through π-complexation, while TCNQ activated surface of AgNPs for partial polarization as a strong electron acceptor. The FT-IR and TEM image supported improved interactions between PEMA-g-PPG and AgNPs. The best separation performance was obtained with 1:3 wt ratio of PEMA-g-PPG:AgNPs, showing 7.8 GPU for mixed gas permeance and 17.5 selectivity for propylene/propane.

As ZIF materials have their unique properties such as high surface area, tunable pore structure, thermal and chemical stability, they can be used in gas separation. In this work, we synthesized ZIF-8 seed layer by combining ZnO coating on the support and the conversion synthesis of ZnO layer in H-mIm solution to ZIF-8 layer, followed by the secondary growth synthesis for ZIF-8 membranes. The effect of solvent on conversion seeding had been investigated to control the reaction rate combining the dissolution rate of ZnO and the crystallization rate. The optimum solvent combination (water and methanol) was studied according to the thickness of the ZnO layer used in the conversion seeding. The obtained membranes showed excellent performance for propylene/propane gas separation. The thicker the ZnO layer, the lower the permeability.

본 연구에서는 제올라이트 4A 분리막((주)파인텍)에서의 물과 알코올(메탄올, 에탄올, IPA, 부탄올)의 1성분, 2성분 그리고 3성분 투과증발 특성을 실험 및 모형을 통해 분석하였다. 다양한 온도 및 농도 조건 실험을 통해 제올라이트 4A 분리막이 알코올로 부터 물을 선택적으로 분리할 수 있음을 확인하였으며, 이때 분리계수는 각각 물/메탄올 150 이상, 물/에탄올 3,000 이상, 물/IPA 1,500 이상, 물/부탄올 1,500 이상이었다. Generalized Maxwell Stefan 모형 및 Dusty Gas 모형을 이용하여 단일성분 및 혼합물의 투과증발 거동을 모사하였으며, Genetic Algorithm을 이용한 상수추정을 통하여 비지지체의 흡착 및 확산 상수를 구하였다.

General D-glass(Dielectric glass) fibers are adaptable to PCBs(Printed circuit boards) because they have a low dielectric constant of about 3.5~4.5. However, very few papers have appeared on the physical characteristics of D-glass fibers. D-glass fibers were fabricated via continuous spinning process using bulk D-glass. In order to fabricate the D-glass, raw materials were put into a Pt crucible, melted at 1650℃ for 2 hrs, and then annealed at 521 ± 10℃ for 2 hrs. We obtained transparent clear glass. The transmittance and adaptable temperature for spinning of the bulk marble glass were characterized using a UV-visible spectrometer and a viscometer. Continuous spinning was carried out using direct melting spinning equipment as a function of the fiberizing temperature in the range of 1368℃ to 1460℃, while the winder speed was between 100 rpm and 200 rpm. We investigated the physical properties of the D-glass fibers. The average diameters of the glass fibers were measured by optical microscope and FE-SEM. The average diameters of the D-glass fibers were 21.36 um at 100 rpm and 34.06 um at 200 rpm. The mechanical properties of the fibers were confirmed using a UTM(Universal materials testing machine). The average tensile strengths of the D-glass fibers were 467.03 MPa at 100 rpm and 522.60 MPa at 200 rpm.

본 연구에서는 완도 해역에서 단기적인 수온의 변화에 영향을 주는 요인을 파악하기 위하여 시계열 분석을 실시하였다. Power spectrum 결과에서 기온은 약 24 hr에서 peak를 보였으나 수온과 조위는 약 12 hr 및 24 hr에서 peak가 나타났다. 수온과 조위의 상관 성을 파악하기 위해 coherence 분석을 실시한 결과, 두 변수는 반일주기에서 0.92로 높은 상관성을 보였다. 또한 수온의 시·공간적인 분포를 파악하기 위하여 수치실험을 실시하였다. 대조기에는 최강 낙조와 최강 창조 시의 평균 수온차가 0.3 인 반면, 소조기에는 평균 수온차가 0.13 로 작았다. 대조기의 수온차가 큰 이유는 비교적 수온이 낮은 외해수가 강한 조류에 의해 창조 시 유입되고 낙조 시 빠져나가기 때문인 것으로 판단된다. 전반적으로 수온은 외해보다 연안에서 높게 나타났다. 외해보다 연안은 수심이 얕기 때문에 일사량에 의해 수온이 빠르게 증가하기 때문인 것으로 사료된다.

The TRM method applied in this study is a method aiming at long span and low girder hight of the temporary bridge. When the preload is introduced to the girder member and the preload is removed after by welding the stiffener, a prestress is introduced through the stiffener to increase the load capacity of the member. Therefore, in this study, the structural performance improvement through the application of the TRM method was verified experimentally by the bending tests of the specimens with and without the TRM method.

The purpose of this study is to develop a carbon fiber sheet with embedded fiber optic sensor for maintenance and performance improvement of aged concrete bridges. The carbon fiber sheet bonded method has many advantages in terms of member repair and reinforcement, but it is disadvantageous in that it is necessary to directly identify the separate point generated during the bonded of the carbon fiber sheets by an artificial method. In this study, we examined the method of confirming the separate point of the carbon fiber sheets by examining the strain of the fiber optic sensor embedded in the carbon fiber sheets. The strain rate measured by the fiber optic sensor was replaced by the strain of the carbon fiber sheets derived from the FEM analysis.

In this study, tensile stresses of partially delaminated CFRP sheets were analytically evaluated. The analytical model is a 15-m long concrete beam with a rectangular cross-section of 2×3 m and uses 480 2D-plate elements and 5760 3D-solid elements for mesh construction. The elastic modulus of concrete and CFRP sheet used in the analysis are 27,536 MPa and 200,000 MPa, respectively, and the compressive strength of concrete and tensile strength of CFRP sheet are 30.0 MPa and 4,000 MPa, respectively. In order to evaluate the change of the tensile stress due to the delamination of the CFRP sheet, the whole attached model and the partially delaminated model according to the position of delamination were considered. As a result of the finite element analysis, the tensile stress of the entire attached CFRP sheet showed a constant tensile stress on the whole cross section, and the tensile stress of the partially delaminated CFRP sheet showed the maximum tensile stress on the position of delamination. Based on the results of this study, future research will be carried out to optimize the layout and shape of CFRP sheets embedded with optical fiber sensors.

본 연구는 예부터 약용으로 사용되었거나, 현재 식품공 전에 식품원료로 사용이 가능한 것으로 등록된 국내 산림 지역에 자생하는 식물을 식품산업에 활용하고자 선행연구에서 우수한 항산화 활성을 보인 갈참나무 잎을 본 연구 에서 사용하였다. 70% 에탄올을 이용하여 추출한 갈참나무 잎을 이용하여, hydrogen peroxide로 산화적 스트레스를 유도한 피부 섬유아세포에서의 세포 보호효과, 세포내 항산화 효과 및 항노화 효과를 측정하였다. 세포 독성을 평가한 결과 25, 50 및 100 μg/mL의 갈참나무 잎 추출물을 처리하였을 때 모두 독성을 나타내지 않았으며, hydrogen peroxide로 산화적 스트레스를 유도한 상태에서는 세포를 보호하여 농도 유의적으로 세포생존율이 증가하였다. 특히, 100 μg/mL의 농도에서는 양성대조군으로 사용한 50 μM ascorbic acid 수준까지 세포 생존율이 증가하였다. 세포내 항산화 효과를 확인 하기위해 사용한 H2-DCFDA assay에서는 형광현미경과 형광흡광도 측정에서 모두 농도 유의적으로 세포내 ROS 저감 활성을 확인하였고 갈참나무 잎 추출물을 100 μg/mL 농도로 처리했을 때는 50 μM ascorbic acid와 비슷한 세포내 항산화 효과를 나타내었다. 또한 SA- β-galactosidase assay를 이용한 갈참나무 잎 추출물의 피부 섬유아세포에 대한 항노화활성은 ROS 생성 억제 효과 와 유사한 경향으로 갈참나무 잎 추출물의 농도 유의적으로 세포 노화 억제효과를 확인하였다. 이상의 결과를 종 합하여 볼 때 갈참나무 잎 추출물이 hydrogen peroxide로 인한 산화적 스트레스 상태에서 세포 보호효과, 항산화 효 과 및 항노화 효과가 관찰되어 기능성 식품원료로서의 활용도가 매우 넓을 것으로 판단된다.

두유는 단백질, 지방, 다당류 등으로 구성된 에멀젼으로서 저장 중 상분리 또는 침전 현상이 발생하게 되는데, 이에 가장 큰 영향을 미치는 것은 입도크기인 것으로 알려져 있다. 최근 보고에 의하면 양친매성의 계면활성제는 두유의 이러한 현상을 억제하는 중요한 역할을 하는 것으로 알려져 있다. 따라서 본 연구에서는 두유의 가공조건과 천연 계면활성제인 사포닌(순도=80%)이 두유의 저장 안정성에 미치는 영향을 확인하고자 하였다. 실험에 사용한 두유액은 고형분을 제거한 후, 사포닌을 0%, 1%(w/w)를 각각 첨가하였으며, 고속균질기와 고압균질기를 순차적으로 사용하여 입도가 균일한 두유로 제조하였다. 두유의 저장 안정성 테스트를 위하여 15일 동안 저장(온도=4℃, 25℃ and 37 ℃) 하면서 visual appearance, microstructure, transmittance, particle size distribution, terminal velocity를 각각 측정 하였다. 두유의 상분리는 25 ℃와 37 ℃에서 GSP 0% 첨가의 경우 각각 120 및 48 h 후 GSP 1% 첨가의 경우 각각 192 및 48 h 후에 발생하였으나, 4℃에서는 저장기간 동안에 관찰되지 않았다. 저장기간 동안, 두유의 microstructure는 GSP 0% 첨가의 경우 입자가 응집되는 것이 관찰 되었으나, GSP 1%를 첨가한 경우 두유 입자의 응집 현상은 관찰되지 않았다. 모든 샘플은 저장 시간이 지남에 따라 transmittance가 증가하는 경향을 보였는데, 높은 저장온도에서 transmittance가 빠르게 증가하였다. 두유의 입도크기는 저장 0 h에서 GSP 0% 첨가의 경우 8.8 μm로서 GSP 1% 첨가의 경우(12.3 μm)보다 작은 값을 나타내었다. 이후 저장 시간이 지남에 따라 입도 크기가 감소하는 경향을 보였는데, 저장온도 25 및 37 ℃에서는 저장 2 h 이후부터 GSP 1%와 0% 간에 유의적인 차이는 나타나지 않았으나, 4 ℃ 저장의 경우 360 h에서 GSP 0% 첨가의 경우 0.99 μm로서 GSP 1% 첨가의 경우(0.72 μm)보다 큰 값을 나타내었다. GSP가 입자 침전 속도에 미치는 영향인 terminal velocity는 저장온도 25 및 37 ℃에서는 유의적인 차이는 나타나지 않았으나, 4 ℃ 저장의 경우 360 h 후 GSP 0%와 1% 첨가하였을 때 각각 0.31 mm/h, 0.16 mm/h로 측정되어, GSP를 첨가하는 경우에 terminal velocity를 낮추었다. 위의 결과를 토대로, 천연 계면활성제인 사포닌은 두유의 상분리를 억제하여 저장 안정성을 향상시키는 효과가 있음을 확인하였다.

본 연구는 딸기에서 발생하는 흰가루병 방제에 사용되는 살균제의 잔류시험을 수행하고 회귀방정 식 및 생물학적 반감기를 산출하여 한국과 일본, Codex의 잔류허용기준에 근거한 농약의 사용 및 안전한 농산물 생산에 기여하고자 수행되었다. 딸기재배 중 흰가루병 방제용 주요 살균제 boscalid, kresoxim-methyl, pyraclostrobin, pyrimethanil을 각 농약의 안전사용기준에 따라 기준량 1회 살포 후 1, 3, 5, 7, 9, 11, 13일에 딸기 시료를 채취하여 QuEChERS법을 이용하여 추출하고, NH2 SPE 카 트리지로 정제하여 HPLC/DAD로 분석하였다. 시험농약의 검출한계 및 정량한계는 4성분의 농약에서 모두 0.01과 0.03mg/kg이었으며, 평균회수율은 92.9~99.2%, 상대표준편차는≤5%로 산출되었다. 딸기 중 boscalid, kresoxim-methyl, pyraclostrobin, pyrimethanil의 생물학적 반감기는 기준량처리 시 각각 6.2, 4.0, 6.1, 6.6일로 나타났다. 이러한 결과로, 시설재배지 딸기 흰가루병 방제를 위해 사용되는 살균제의 안전 사용을 통해 국내 및 주요 수출국가의 MRL을 초과하지 않는 안전한 딸기를 생산하는데 기여할 것으로 기대된다.