• 문화기술의 융합
• /
• 제8권6호
• /
• pp.667-674
• /
• 2022

침목플로팅궤도(STEDEF)의 콘크리트침목은 2개의 콘크리트블럭을 타이바로 연결하여 구성된 형태이며 침목방진패드 및 침목상자와 도상 콘크리트층에 매립되어 레일로 전달되는 열차하중을 지지하고 하중을 도상으로 분산시키는 역할을 수행하는 주요 궤도구성품이다. 침목방진패드는 열차의 반복운행에 따른 누적하중 증가, 장기간 사용에 따른 열화로 인해 재료적 성능이 저하되어 다른 궤도구성품의 손상을 유발할 수 있다. 실제 형상과 동일한 3D 모델링으로 운행하중 조건에서 발생되는 침목플로팅궤도구조의 거동을 파악하고, 수치해석을 통해 침목방진패드의 스프링강성 변화가 콘크리트침목의 손상에 미치는 영향을 분석하였다. 분석결과, 침목방진패드의 좌·우측 스프링강성 증가는 콘크리트침목의 최대 응력 및 인장응력, 변위는 증가하고 레일 직하부 침목의 최대 압축응력은 감소하며, 타이바접촉부 콘크리트에서 응력집중이 되는 것으로 분석되었다. 이는 현장조사결과의 콘크리트침목 손상유형과도 일치하는 것으로서 침목방진패드의 장기간 사용에 따른 스프링강성 변화는 콘크리트침목의 응력 증가를 초래할 수 있으며, 좌우 침목의 침하량의 차이가 증가되어 콘크리트침목의 손상에 영향을 미칠 수 있음을 해석적으로 입증하였다.

• 지질공학
• /
• 제33권4호
• /
• pp.599-609
• /
• 2023

국내 항만 방파제의 내진보강시 현장여건, 현장상황 등으로 회수율이 불확실한 경우가 많아 문제점이 지속적으로 발생하고 있다. 따라서, 본 연구에서는 저유동성 몰탈주입 공법 적용 후 그라우팅 확인방법으로 시추조사를 통한 회수율 및 개량체의 압축강도를 분석하였으며, 추가적으로 다운홀 테스트 및 토모그래피로 탄성계수를 확인하여 지반개량 후 연약지반의 보강 증대 효과를 확인하고자 하였다. 실험결과, 다운홀테스트의 경우 BH-1번과 3번공에서 심도 28.0 m까지에 대한 지반의 평균 전단파속도는 229 m/s에서 288 m/s로 증가하였고, 심도 30.0 m까지에 대한 지반의 평균 전단파속도는 224 m/s에서 282 m/s로 증가하는 경향을 보였다. 이는 보강후 지반의 강성이 증대되어 나타난 결과로 판단된다. 토모그래피 탐사 결과, Site1번의 시료의 연약지반의 Vs가 113 m/s에서 214 m/s, Site2번 시료의 Vs는 120 m/s에서 224 m/s로 증가하였다. 이는 전단파속도에 따른 암질의 분류에서 Vs값이 180~360 m/s를 만족하는 값으로 내진보강 후의 지반의 강성이 단단한 흙으로 보강됨을 확인할 수 있다.

• 한국수소및신에너지학회논문집
• /
• 제25권5호
• /
• pp.509-515
• /
• 2014

At the fuel processing system (FPS) of fuel cell vehicle, hydrogen recirculation blower (HRB) is used for the recirculation of remained hydrogen after reaction. In this paper, noise and vibration improvement of HRB is studied by changing design and control. It is checked the campbell diagram and critical speed for stability of rotor, and housing stiffness is improved using simulation of frequency response function (FRF). A method is suggested that can decrease the unbalance amount of the rotor and impeller which main source of noise and vibration. In order to reduce the noise during deceleration of blower, electrical braking is applied and tested the risk impact of durability. Founded the optimum switching frequency of the motor control, and reduced the idle rpm by increasing of aerodynamic performance. The superiority of paper is proved by measurement of the improved product's noise and vibration.

• 한국의류산업학회지
• /
• 제19권6호
• /
• pp.759-767
• /
• 2017

This study investigates the improvement of domestic compression stockings by comparing and analyzing the characteristics of materials and fabrics of medical compression stockings developed in Korea and domestic imported compression stockings. Among imported compression stockings currently available in Korea, three brands with high sales rates are selected by countries (USA, Italy, and Germany) to measure the physical and mechanical properties of the material. Medical compression stockings to be analyzed were selected as M size pantyhose included in 20-30mmHg. As a result, the tensile elongation of medical compression stockings selected in this study was the highest in Korean products in the ankle, while the highest in the US was in the thigh, and the elasticity of Italian products was low. The recovery rate of the kidneys was similar for all four ankles. The ankle weight was the highest except for Korean products that showed the highest weight of the thigh and difference from products of other countries. US product also showed high shape stability due to high recovery of tensile strength from high value RT. Italian products showed low banding and shear values; however, shape stability was poor with good drapeability. In Germany, LT and RT values were low, but clothing comfort was considered excellent. In Korea, LT and RT values, banding and shear characteristics were high, and drapeability was poor. Stiffness was good, but recoverability was excellent.

• 한국지반환경공학회 논문집
• /
• 제2권3호
• /
• pp.57-69
• /
• 2001

샌드파일 공법은 연약지반 개량을 위해 널리 사용되는 방법중의 하나이다. 샌드파일 설치에 의해 얻고자 하는 주된 목적은 압밀촉진에 있으나 이와 더불어 복합지반효과를 지니게 된다. 본 연구에서는 상대적으로 면적 치환비가 작은 연직배수재로서 적용된 샌드파일 설치지반에서의 복합지반효과를 파악하고자 하였다. 이를 위하여 원지반과 샌드파일의 지내력 확인을 위한 평판재하시험을 실시하였으며, 성토체와 지반과의 상호거동을 확인하기 위하여 토압계를 설치하여 계측관리를 실시하였다. 분석결과 면적치환비가 작은 샌드파일 설치지반에서 복합지반을 고려한 지지력은 원지반의 지지력과 비교하여 매우 작은 증가효과를 보였다. 그러나 원지반과 비교한 샌드파일 설치위치에서의 지지력 증가는 약 60% 로 나타났다. 이와 같이 샌드파일의 강성증대에 의한 파일설치 위치에서의 지지력 증대는 재하하중 작용에 의한 압밀진행 과정중 압밀특성 변화의 요인으로 작용하게 될 것이다. 따라서 샌드파일 강성증대에 따른 복합지반효과는 샌드파일 설치지반에서 압밀침하량이 감소하는 요인으로 평가될 수 있는 것으로 판단된다.

• 패션비즈니스
• /
• 제8권1호
• /
• pp.141-155
• /
• 2004

Chitosan, the natural biodegradable polymer derived from chitin by de- acetylation, has been widely applied to the textile finishing processes for excellent anti-microbial characteristic and handle improvement of fabric. The purpose of this study is to investigate the change of handle when cotton fabric is treated with chitosan-polyurethane mixed solution. The viscosity values of chitosan solutions were 8cps and 50cps, and the wet-pick-up% was maintained at 90%. In case of mixing with water soluble polyurethane, the mixture ratio of chitosan and polyurethane was settled on the solid content ratio of 1:0, 1:0.5, 1:1, 1:2. Also the change of physical properties by neutralization in NaOH solution was studied. The results can be summarized up as follows : 1. Extensibility(EM) and tensile energy(WT) of cotton fabric treated with chitosan are decreased, but bending rigidity(B) is remarkably increased. With the addition of polyurethane, the decrease of EM and WT is weakened and the increase of B is weakened. The case of neutralization is similar to the case of polyurethane addition. 2. By treating fabric with chitosan, FUKURAMI(Fullness and softness) is decreased, but KOSHI(Stiffness), SHARI(Crispness), HARI(Anti-drape Stiff ness) are increased. With the addition of polyurethane, the decrease of FUKURAMI is diminished and the increase of KOSHI, SHARI, HARI are diminished. 3. As the viscosity of chitosan solution increased, the air permeability value increased. The addition of polyurethane decreased the air permeability.

• 펄프종이기술
• /
• 제47권1호
• /
• pp.10-16
• /
• 2015

Bio-binder is well known as a promising alternative binder for SB latex because it is eco-friendly and inexpensive, compared to synthetic latex. SB latex in top coating color was substituted with starch-based bio-binder to investigate its effects on the coating color and its coated paper properties. Bio-binder contributed to the increase of coating color viscosity, and the improvement of water retention. Most optical properties except opacity were deteriorated by the increase of bio-binder dosage. It was also found that the increase of bio-binder substitution in top coating color brought about the increase of roughness, and decrease of coated paper gloss, print gloss, dry and wet pick strength. However the stiffness and the ink set-off of the bio-binder coated paper were improved. Overall, mostly adverse effects of bio-binder on the properties of coating color and its paper were observed. Therefore, it is not recommended to use bio-binder as top coating color.

• 펄프종이기술
• /
• 제42권1호
• /
• pp.41-47
• /
• 2010

Increasing ash content of the paper is one of the most effective methods for saving raw materials and steam consumption and improving optical properties and better print quality. However, the increase of filler loading or filler content using a conventional wet end system is limited due to severe loss in strength properties, affecting runnability and product quality. This is because the filler has no ability to make bonding with cellulosic fibers. Therefore, if the technology to give filler the bonding ability is developed, the ash content of the paper can be increased more than ever. This study was carried out to modify PCC by coating its surface with starch contributing to better bonding with fibers. To prepare the modified PCC, cationic starch was selected as a polymer and then pretreatment was done by mixing PCC and cationic starch. Consequently, the pretreated PCC contributed to higher tensile strength, stiffness and opacity than the conventional filler, such as GCC and untreated PCC. However, CIE whiteness and ISO brightness decreased slightly compared to conventional fillers.

• 한국잠사곤충학회지
• /
• 제27권2호
• /
• pp.28-39
• /
• 1985

견직물의 실용성능(방추도, 세탁성)을 개선할 목적으로 실크하브다이(silk habutae)에 실리콘수지를 유화 가공법으로 처리하였다. 실리콘가공 하브다이의 방추도, 발수도, 유연도, 강신도, 수분율 등은 직물검사 방법에 따라서 검사하였고 가공 후 견피브로인의 구조적인 변화를 구명하기 위하여 주사전자현미경, 아미노산분석, X-선 회절강도, FT-IR 흡수분석에 의하여 검토한 결과 아래와 같은 결과를 얻었다. 1) 견하브다이 직물의 방추도는 soaping 처리오 큐어링 조건에 의하여 현저히 개선되었다. 2) 실리콘 수지 가공에 의하여 견하브다이의 발수도와 유연도가 향상되었고, 가공 후 silk fibroin을 주사전자현미경으로 관찰한 결과 견섬유 특유의 불규칙한 섬유표면은 평활하게 관찰되었다. 3) 실리콘 수지와 silk fibroin의 반응에 따라서 피브로인 조성 아미노산 중 극성기를 가지고 있는 아미노산의 감소비율이 현저하였다. 4) 실리콘 수지가공 silk habutae는 soaping에 의하여 X-선 회절강도가 높아지는 경향이었다. 5) 가공 후 견하브다이의 FT-IR 흡수곡선에 실록산등의 peak가 검출된 것으로 미루어 fibroin의 개질이 가능하다고 생각된다.

• 한국의류학회지
• /
• 제34권1호
• /
• pp.138-152
• /
• 2010

This study investigates the actual hospital-clothes consumption experience of consumers according to gender and age. An all age survey was conducted among male and female ex-patients in Korea nationally. From data collected during April and May 2009, a total of 513 responses were analyzed using descriptive statistics, chi-square analysis, two-way ANOVA, and MANOVA using SPSS 10.1.4. The results are as follows. The hospitalization ratio was higher in the male group than in the female group and increased with age. Many hospitalizations were taken to the department of orthopedics, internal treatment, obstetrics and gynecology, and surgery. The satisfaction with patient gowns was low regarding size, fabric touch, color and pattern, Psychological comfort, and holistic satisfaction, Specifically, the stiffness of the fabric, cheerless colors, and the limited number of sizes were the main complaints; size dissatisfaction was expressed strongly by females. About 35% of respondents showed a positive attitude to wear premium patient gowns. Various medical supplies were used and different items were utilized according to gender and age of patients. Uncomfortableness of medical supplies were highly related to laundry and fabric touch.