• Journal of the Korean Society of Radiology
• /
• v.12 no.6
• /
• pp.777-783
• /
• 2018

The purpose of this study was to investigate the degree of tearing of the rubber when the spike of the syringe connector was connected to the bottle of the contrast medium composed of the rubber compound type and to investigate the presence of the synthetic rubber due to tearing and grinding and the size of the pulverized product when the pulverized matters rubber was detected. As a result, in the case of tearing degree, the front side of the first contact with the end of the syringe connector was torn more than the back side by about $3.14{\pm}0.04mm$, and the pulverized matters was detected on average 7 to 15 on the 10 contrast mediums. The average particle size was measured to be about $7.89{\pm}0.31{\mu}m$. In addition, it is necessary to develop a micro_filter type automatic injection system for blocking off the pulverized matters as well as additional experiments through various experiments and analysis methods, and it is considered that interest of related organizations will be needed in preparation of fatal accidents when pulverized matters is introduced.

• Journal of Korean Society of Steel Construction
• /
• v.20 no.4
• /
• pp.519-528
• /
• 2008

A simple steel-concrete composite deck is developed for preventing the lateral torsional buckling of girders that are under construction and for reducing the term of works using H-shaped rolled beams as bridge girders. A new type of shear connectors is also developed for the composite behavior between a simple steel-concrete composite deck and the rolled beams by the connecting conditions between the deck and the girders. One is a connector bolt that is lengthened and split or tightened with two nuts and the other is an I-shaped rolled beam welded on a steel plate with a number of holes punched through the web. In this study, to estimate the shear strength of those shear connectors the push-out tests are performed and the test results are compared with that of the previous studies and the codes. The result of the push-out tests of the connector bolts showed that the shear performance is similar to that of the stud connector and revealed that the equation for the shear strength in the Korean Specification of Highway Bridge overestimates the shear capacity of the connector bolt whose diameter is larger than 19mm. From the push-out tests of punched I-shaped rolled beams with varying welding amounts, with the small amount of welding, shear capacity is governed by the shear capacity of welding. On the other hand, shear capacity is governed by the size of the punched I-shaped rolled beams, regardless of the amount of welding.

• Steel and Composite Structures
• /
• v.31 no.1
• /
• pp.53-67
• /
• 2019

This study presents finite element analysis (FEA) on a Y-type perfobond rib shear connection using Abaqus software. The performance of a shear connection is evaluated by conducting a push-out test. However, in practice, it is inefficient to verify the performance by conducting a push-out test with regard to all design variables pertaining to a shear connector. To overcome this problem, FEA is conducted on various shear connectors to accurately estimate the shear strength of the Y-type perfobond rib shear connection. Previous push-out test results for 14 typical push-out test specimens and those obtained through FEA are compared to analyze the shear behavior including consideration of the design variables. The results show that the developed finite element model successfully reflects the effects of changes in the design variables. In addition, using the developed FEA model, the shear resistance of a stubby Y-type perfobond rib shear connector is evaluated based on the concrete strength and transverse rebar size variables. Then, the existing shear resistance formula is upgraded based on the FEA results.

• Journal of electromagnetic engineering and science
• /
• v.1 no.2
• /
• pp.139-145
• /
• 2001

In this paper, a coaxial sample holder is proposed with its de-embedding and parameter extraction procedure. The S-parameters were measured up to 1 GHz using network analyzer, HP8753D, and N-type connector together with the de-embedding of N-type connector. The proposed de-embedding procedure is performed to extract electrical parameters of blood glucose, which gives the permittivity of blood glucose. We also analyzed the error of extracted parameters, which are caused by instrument error and geometrical error. Using these error analyses, we reduced the error factors of extracted parameters. We extracted electrical parameters of glucose samples through these all extraction procedure and confirmed the possibility of glucose diagnosis system based on microwave system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.11a
• /
• pp.470-471
• /
• 2007

Underground connectors in 154kV for the connection between power cables and power equipments represent a greater part of power system stability and reliability. This paper presents the performance evaluation of 154kV separable dry type plug-in connector of a company in Japan for transformers and Gas Insulated Switchgear. And the possibility of the application on domestic underground line was considered.

• Tribology and Lubricants
• /
• v.35 no.1
• /
• pp.52-58
• /
• 2019

In the case of high-voltage connectors applied to automobiles, waterproofing has become an important issue for the safety of automobiles. In this study, structural analysis is performed on silicone rubber-type waterproof seals used in the voltage connector. For the structural analysis, the tensile properties of the actual rubber seal are evaluated using a miniaturized tensile testing machine. The Mooney-Rivlin material constants of the rubber seal are determined as follows; $D_1=0$, $C_{01}=0.241$, $C_{10}=0.0142$. The analysis shows that the contact pressure at the top of the seal where the seal and male connector are in contact is approximately three times higher than that at the bottom of the seal where the seal and female connector are in contact. It is confirmed that the waterproofing performance of the rubber seal depends on the contact pressure of the seal bottom where the seal and female connector are in contact. The contact pressure for waterproofing is found to be 4.7 bar. The strain concentration of the curved part is attributed to excessive initial tension. Therefore, a redesign is recommended for uniform stress or strain distribution in the curved section of the seal in response to the stress relaxation problem due to permanent deformation.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.3A
• /
• pp.375-381
• /
• 2008

This paper deals with the shear capacity of corrugated rib as the shear connector in composite structures. Corrugated rib is modified as perfobond rib shear connector type to evaluate the shear capacity. A total 12 push-out specimens with stud, perfobond rib, and corrugated rib connector were fabricated. Then, the influences of hole-crossing bars, concrete dowel, depth of corrugated panel and height of rib on the shear capacity were evaluated experimentally. As the results of these tests, the failure mechanisms of corrugated rib and perfobond rib specimens were associated with the bearing failure of the concrete slabs, but the failure of weld zone did not occur. The shear capacity of corrugated rib specimens improved as high to 96% compared to the perfobond rib shear connectors. Also, the hole-crossing bars were effective on the improvement of concrete dowel action, and consequently, shear capacity increased by 48%. It was also proven that the increment of the depth of corrugated panel and the height of rib increased the concrete bearing resistance, therefore increasing the shear capacity.

• Magazine of the Korea Concrete Institute
• /
• v.27 no.3
• /
• pp.43-47
• /
• 2015

• Steel and Composite Structures
• /
• v.36 no.1
• /
• pp.1-16
• /
• 2020

In steel-concrete composite beams, to improve the cracking resistance of the concrete slab in the hogging moment region, a new type of connector in the interface, named uplift-restricted and slip-permitted screw-type (URSP-S) connector has been proposed. This paper focuses on the behavior of steel-concrete composite beams with URSP-S connectors. A total of three beam specimens including a simply supported beam with URSP-S connectors and two continuous composite beams with different connectors arrangements were designed and tested. More specifically, one continuous composite beam was equipped with URSP-S connectors in negative moment region and traditional shear studs in other regions. For comparison, the other one was designed with only traditional shear studs. The failure modes, crack evolution process, ultimate capacities, strain responses at different locations as well as the interface slip of the three tested specimens were measured and evaluated in-depth. Based on the experimental study, the research findings indicate that the larger slip deformation is allowed while using URSP-S connectors. Meanwhile, the tensile stress reduces and the cracking resistance of the concrete slab improves accordingly. In addition, the overall stiffness and strength of the composite beam become slightly lower than those of the composite beam using traditional shear studs. Moreover, the arrangement suggestion of URSP-S connectors in the composite beam is discussed in this paper for its practical design and application.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.4D
• /
• pp.361-368
• /
• 2010

It is general that mostly congested sections of national backbone networks have been improved based on the national network expansion plan. However, in case of intermodal terminals which are origins of logistics, it is still so congested that travel time between origin and destination is long. Therefore, intermodal transportation systems plan of major intermodal terminals for the intermodal connector networks between intermodal terminal and national backbone network or intermodal terminal was established. With the limitation of priority methodology applying to intermodal connector facility under existing methodology, this study suggests an improved priority methodology. This study includes characteristics of terminal on the hierarchical structure and assessment list, but it does not concentrate on the specific terminal type through survey. To avoid a certain concentration, budget constraint for each terminal type was considered ahead of priority. Finally priority methodology was developed with two-step assessment under consideration that specific terminal is not involved in intermodal connector facility project. As a result of calculating weights by survey, effects such as d/c and accessibility fluctuations index through project implementation gain high weight, and degree of region underdevelopment gets next. Although the methodology in this study could not yields the priority by assessment list, it will be useful for setting the direction on policy related to intermodal connector facility projects.