• Title/Summary/Keyword: dry test

Search Result 1,846, Processing Time 0.026 seconds

The Frost and Defrost Performances of Fin-and-Tube Heat Exchangers with Different Surface Treatment Characteristics (서로 다른 표면특성을 갖는 핀-관 열교환기의 착상과 제상 성능평가)

  • 최봉준;황준현;신종민
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.14 no.10
    • /
    • pp.781-785
    • /
    • 2002
  • The effects of different surfaces on dry and wet frosting test were experimentally investigated. The results of experiment were compared by the performance evaluation coefficient (PEC). Results showed that the air-side pressure drop of lacquer coated evaporator increased by 5% as compared to the plasma treated one. It was also found that the Plasma coated evaporator is lower than lacquer coated one in the PEC ratio.

Evaluation of Corrosion Protective System for Reinforced Concrete Structures Constructed With Sea Sand (해사 혼입된 콘크리트 구조물의 부식도 평가)

  • 김웅희;홍기섭;오승모;장지원;최응규;최완철
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 1997.04a
    • /
    • pp.203-209
    • /
    • 1997
  • An experimental study to evaluate to evaluate corrosion protection systems was undertaken with 44 reinforced concrete slab specimens subjected to cyclic wet and dry saltwater exposure. Corrosion measurements included monitoring macrocell corrosion currents, which are genrerally accecpted in United States practice. Test results indicate that specimens containing 2 kg/$\textrm{m}^3$ of NaCl and exposed to wet(outdoor) and dry(indoor) conditions but not to saltwater show very low values of corrosion measurements regardless applying any corrosion protective systems. Corrosion currents of the specimens exposed at 10 percent of NaCl were higher than that of the specimen exposed at 5 percent of NaCl, so the density of the salt water had an influential effect on the test. For the specimens with water repellent membrane currents kept relatively low numerical values, but test specimens with surface corrosion inhibitor protective system showed high values of corrosion current. It would be expected that evaluation of the corrosion protective systems need long-term measurement.

  • PDF

Tracking Property of Polymer Suspension Insulator for Transmission line with secular variation (경년변화에 따른 송전용 폴리머 현수애자의 트래킹 성능평가)

  • Cho, Han-Goo;Lee, Un-Yong;Lee, You-Jung;Lim, Kee-Joe;Choi, In-Hyuk
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2005.07a
    • /
    • pp.558-559
    • /
    • 2005
  • Recently, polymer insulators that are used for high voltage applications have some advantages such as light weight, small size, vandalism resistance, hydrophobicity and easy making process. During outdoor service of polymer insulators, the surface of the insulating material is frequently subjected to moisture and contamination that lead to dry band arcing. Their tracking resistance, erosion resistance, end sealing and shed design are very important because dry band arcing causes degradation of polymer surface. In this paper, the tracking property of polymer suspension insulator for power transmission is investigated with CEA tracking wheel test. The diagnosis of insulator sample in tracking test has been analyzed by leakage current, STRI Guide, SEM, FTIR and thermal image.

  • PDF

Friction and Lubrication Behaviors of Rabbit Joint Cartilage (토끼 관절연골의 마찰 및 윤활 특성)

  • 이권용;이홍철
    • Tribology and Lubricants
    • /
    • v.17 no.4
    • /
    • pp.307-311
    • /
    • 2001
  • The friction and lubrication characteristics of joint cartilage were investigated using the metatarso-phalangeal joint cartilage of rabbit against rotating stainless steel disk. Friction tests were conducted by dry and bovine serum lubricated sliding at room and body temperatures. For the dry sliding tests, low friction coefficient of 0.1-0.15 was observed at the early period of test, and then the friction coefficient increased as a test continued. With increasing applied load the early period of low friction lengthens. For the lubricated sliding tests, the coefficient of friction decreased as the applied load increased. And also the coefficient of friction decreased continuously to 0.07 as the test duration increases. These results can be interpreted that the squeeze or weeping lubrication mechanism dominates the friction and lubrication characteristics in the joint cartilage of rabbit.

The Test for Verifying a Tip-Over Analysis of a Dry Storage Cask (건식저장용기에 대한 전복해석의 검증시험)

  • Kim Dong-Hak;Seo Ki-Seog;Lee Ju-Chan;Cho Chun-Hyung;Jang Hyun-Kee;Choi Byung-Il
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.4 no.3
    • /
    • pp.245-253
    • /
    • 2006
  • A test of the 1/3 scale model was conducted to verify the tip-over analysis of a dry. concrete storage cask under a hypothetical accident condition. The tip-over analysis was executed using the velocity at each point as the initial conditions of the model just before the impact. The initial velocity was determined from the initial angular velocity, which would make the equivalent kinetic energy to the potential energy. To confirm the structural integrity of the canister, the visual testing and the non-detective testings such as Liquid Penetrant testing and Ultrasonic Testing were conducted. The lid of a storage cask was plastically deformed near the impact point. The structural integrity of storage cask was maintained. To verify the tip-over analysis the strains and the accelerations acquired by the tip-over test were compared with those by the analyses. The results of the analysis were larger than the test results about two times.

  • PDF

Studies on the Calculating Method of Conditioned Weight by dry Weight after Boiling-off in Raw Silk (생사정량산정에 있어서 연감후 무수량의 도입에 관한 연구)

  • 김수현;이상근;김영진
    • Journal of Sericultural and Entomological Science
    • /
    • v.13 no.1
    • /
    • pp.73-78
    • /
    • 1971
  • The purpose of this study is to find out the method of conditioned weight test by which the dealing weight of raw silk can be calculated from true fiber in order to do the fair trading. The results of this study were as follows. 1. It is more reasonable than the current test that conditioned weight as a dealing weigh can be calculated by boil-off and moisture regain which is a percentage of boil-on and moisture regain to net weight. Because the boil-off and moisture regain can show directly the amount of true fiber and reproductibility in raw silk. In this study the boil-off and moisture regain is to take dry weight after boiling-off from net weight. 2. To calculate the conditioned weight from boil-of and moisture regain it would be proper that the standard additional ratio is 44 per cent of dry weight after boiling-off. 3. Boil-of percent of the sizing sample skein used in the size test did not show a statistical significance comparing with the boil-off percent of sample skeins (24 skeins) which may represent that of a lot. To observe this result boil-off percent of the sizing sample skein may represent that of a lot. 4. In Korea if conditioned weight test substitute for test of boil-off and moisture regain, we make a profit of two billion won in a year at the current market-price.

  • PDF

Experimental Performance Characteristics of Crumb Rubber-Modified(CRM) Asphalt Concrete (폐타이어활용 아스팔트 콘크리트의 실험적 공용특성)

  • Kim, Nak-Seok
    • Journal of the Korean Society of Hazard Mitigation
    • /
    • v.3 no.2 s.9
    • /
    • pp.89-97
    • /
    • 2003
  • Indirect tensile strength(IDT) test and resilient modulus(Mr) test were performed to evaluate experimental performance characteristics for the conventional and crumb rubber-modified(CRM) asphalt concrete using dry and wet processes asphalt. The IDT test was conducted under three temperatures(5, 10, 20$^{\circ}C$). According to the test results, it was shown that indirect tensile strength of CRM asphalt concrete was lower than that of the conventional one. However, toughness and maximum vortical strain of the CRM asphalt concrete were higher than those of the conventional one. The results of Mr test were presented that Mr of CRM asphalt concrete was higher than that of the conventional one. In addition, it was revealed that the overall laboratory performance characteristics of the wet-processed CRM asphalt concrete was better than those of the dry-processed one.

FRICTION CHARACTERISTICS OF A PAPER-BASED FRICTION MATERIAL

  • Gao, H.;Barber, G.-C.;Chu, H.
    • International Journal of Automotive Technology
    • /
    • v.3 no.4
    • /
    • pp.171-176
    • /
    • 2002
  • A bench test set-up is employed to simulate the friction characteristics of a paper-based friction material operating against a steel plate. Dry friction tests are run as well as tests with transmission fluids. Glazed friction material produces a negative coefficient of friction versus sliding velocity (f-v) curve for both dry friction and lubrication with transmission fluids. At low sliding speeds, the coefficient of friction when operating in transmission fluids for glazed friction materials is greater than that under dry friction. An appreciable negative f-v slope occurs at low sliding speeds for glazed friction materials when running with the transmission fluid. The friction material after running in produces a constant f-v curve under dry friction and a negative slope when lubricated with transmission fluid. At low sliding speeds, the coefficient of friction of the run-in friction material is lower than that of the glazed wet material. On the other hand, the run-in friction material has a larger friction coefficient than does the glazed friction material at higher sliding speeds.

Improvement of delayed hydride cracking assessment of PWR spent fuel during dry storage

  • Hong, Jong-Dae;Yang, Yong-Sik;Kook, Donghak
    • Nuclear Engineering and Technology
    • /
    • v.52 no.3
    • /
    • pp.614-620
    • /
    • 2020
  • In a previous study, delayed hydride cracking (DHC) assessment of pressurized water reactor (PWR) spent fuel during dry storage using the threshold stress intensity factor (KIH) was performed. However, there were a few limitations in the analysis of the cladding properties, such as oxide thickness and mechanical properties. In this study, those models were modified to include test data for irradiated materials, and the cladding creep model was introduced to improve the reliability of the DHC assessment. In this study, DHC susceptibility of PWR spent fuel during dry storage depending on the axial elevation was evaluated with the improved assessment methodology. In addition, the sensitivity of affecting parameters such as fuel burnup, hydride thickness, and crack aspect ratio are presented.

A study on the proposal of test condition for apartment bathroom dry waterproofing method for synthetic polymer based waterproof sheet (EPDM) (공동주택 욕실 건식방수공법의 성능시험조건 제안 연구 - 합성 고분자계 방수 시트(EPDM)를 대상으로 -)

  • Seo, Hyun-Jae;Lee, Jung-Hun;Song, Young-Chan;Kim, Yong-Ro;Kim, Byoung-Il;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2018.05a
    • /
    • pp.281-282
    • /
    • 2018
  • Recently, apartment houses are becoming more and more sophisticated and attention has been focused on the design of the interior of the bathrooms. As bathrooms always use water, the importance of waterproofing is very high. However, there continues to use the method that was used 30 years ago. And no one was trying to improve. It is necessary to be converted to a dry method, because waterproofing methods and materials have developed. Therefore, this study proposes the required performance before applying the dry waterproofing material to bathroom.

  • PDF