• Journal of Korean Neurosurgical Society
• /
• 제54권2호
• /
• pp.93-99
• /
• 2013

Objective : Neurologic complications during carotid artery stenting (CAS) are usually associated with distal embolic event. These embolic incident during CAS are highly associated with the carotid plaque instability. The current study was undertaken to identify the angiographic characteristics of carotid plaque vulnerability, which was represented as filling defect in the cerebral protection filters during CAS. Methods : A total of 107 patients underwent CAS with use of a distal protection filter. Angiographic carotid plaque surface morphology was classified as smooth, irregular, and ulcerated. To determine predictable factors of filling defect in the protection filters, 11 variables were retrospectively analyzed which might influence filling defect in the protection filters during CAS. Results : Filling defects during CAS were presented in the 33 cerebral protection filters. In multivariate analysis, angiographic ulceration [odds ratio (OR), 6.60; 95% confidence interval (CI) : 2.24, 19.4; p=0.001], higher stenosis degree (OR, 1.06; 95% CI : 1.00, 1.12; p=0.039), and coexistent thrombus (OR, 7.58; 95% CI : 1.69, 34.05; p=0.08) were highly associated with filling defect in the cerebral protection devices during CAS. Among several variables, angiographic surface ulceration was the only significant factor associated with flow stagnation during CAS (OR, 4.11; 95% CI : 1.33, 12.72; p=0.014). Conclusion : Plaque surface morphology on carotid angiography can be a highly sensitive marker of plaque instability during CAS. The independent risk factors for filling defect in the filter devices during CAS were plaque ulceration, stenosis degree, and coexistent thrombus.

• 한국표면공학회지
• /
• 제46권4호
• /
• pp.153-157
• /
• 2013

The defect like the void or seam is frequently generated in the PCB (Printed Circuit Board) Via-Filling plating inside via hole. The organic additives including the accelerating agent, inhibitor, leveler, and etc. are needed for the copper Via-Filling plating without this defect for the plating bath. However, the decomposition of the organic additive reduces the lifetime of the plating bath during the plating process, or it becomes the factor reducing the reliability of the Via-Filling. In this paper, the interaction of each organic additives and the decomposition of additive were discussed. As to the accelerating agent, the bis (3-sulfopropyl) disulfide (SPS) and leveler the Janus Green B (JGB) and inhibitor used the polyethlylene glycol 8000 (PEG). The research on the interaction of the organic additives and decomposition implemented in the galvanostat method. The additive decomposition time was confirmed in the plating process from 0 Ah/l (AmpereHour/ liter) to 100 Ah/l with the potential change.

• 마이크로전자및패키징학회지
• /
• 제13권4호
• /
• pp.45-50
• /
• 2006

3D package의 SiP에서 구리의 via filling은 매우 중요한 사항으로 package밀도가 높아짐에 따라 via의 크기가 줄어들며 전기도금법을 이용한 via filling이 연구되어왔다. Via filling시 via 내부에 결함이 발생하기 쉬운데 전해액 내에 억제제, 가속제등 첨가제를 첨가하고 펄스-역펄스(PRC)의 전류파형을 인가하여 결함이 없는 via의 filling이 가능하다. 본 연구에서는 건식 식각 방법 중 하나인 DRIE법을 이용하여 깊이 $100{\sim}190\;{\mu}m$, 직경이 각각 $50{\mu}m,\;20{\mu}m$인 2가지 형태의 via을 형성하였다. DRIE로 via가 형성된 Si wafer위에 IMP System으로 Cu의 Si으로 확산을 막기 위한 Ta층과 전해도금의 씨앗층인 Cu층을 형성하였다. Via시편은 직류, 펄스-역펄스의 전류 파형과 억제제, 가속제, 억제제의 첨가제를 모두 사용하여 filling을 시도하였고, 공정 후 via의 단면을 경면 가공하여 SEM으로 관찰하였다.

• Journal of Welding and Joining
• /
• 제18권2호
• /
• pp.191-191
• /
• 2000

The mechanism of the blowhole and the pit formation in lap-jointed fillet CO₂ arc welds of Zn-coated steel sheet was established by the direct observation of the gas behavior in the molten pool with the high speed camera system. Main conclusions obtained are as follows1) Some blowholes were formed by incomplete back-filling to the pits at the last stage of the solidification. This type of blowhole was formed through four stages of gas in the molten pool, incubation, explosion, back-filling and completion of back-filling stage.2) Most of the pits was back-filled at the last stage of their formation. (Received September 27, 1999)

• Journal of Welding and Joining
• /
• 제18권2호
• /
• pp.64-68
• /
• 2000

The mechanism of the blowhole and the pit formation in lap-jointed fillet Co₂arc welds of Zn-coated steel sheet was established by the direct observation of the gas behavior in the molten pool with the high speed camera system. Main conclusions obtained are as follows: 1) Some blowholes were formed by incomplete back-filling to the pits at the last stage of the solidification. This type of blowhole was formed through four stages of gas in the molten pool, incubation, explosion, back-filling and completion of back-filling stage. 2) Most of the pits was back-filled at the last stage of their formation.

• 한국전기전자재료학회논문지
• /
• 제19권2호
• /
• pp.130-138
• /
• 2006

We have investigated pattern scaling down of silicon stamps through the oxidation technique, During oxidizing the silicon stamps, silicon dioxide that has 300 nm and 500 nm thickness was grown, and critical deformations were not observed in the patterns. There was positive effect to reduce size of patterns because vertical and horizontal patterns have different orientation. We achieved pattern reduction rate of $26\%$. In addition, the formation of polymer patterns had been investigated with varied temperature and pressure conditions to improve the filling characteristics of polymers during nanoimprint lithography when pattern sizes were few micrometers. In these varied conditions, polymers had been affected by free space compensation and elastic stress relaxation for filling the cavities. Based on the results, defect control which is an important issue in the nanoimprint lithography were facilitated.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제55권5호
• /
• pp.223-230
• /
• 2006

The reliability of imprint patterns molded by stamps for industrial application of nanoimprint lithography (NIL), is an important issue. Usually, defects can be produced by incomplete filling of negative patterns and the shrinkage phenomenon of polymers in conventional NIL. In this paper, the patterns that undergo a varied temperature or varied pressure period during the thermal NIL process have been investigated, with the goal of resolving the shrinkage and defective filling problems of polymers. The effects on the formation of polymer patterns in several profiles of imprint processes are also studied. Consequently, it is observed that more precise patterns are formed by the varied temperature (VT-NIL) or varied pressure (VP-NIL). The NIL (VT-NIL or VP-NIL) process has a free space compensation effect on the polymers in stamp cavities. From the results of the experiments, the polymer's filling capability can be improved. The VT-NIL is merged with the VP-NIL for the better filling property. The patterns that have been imprinted in the merged NIL are compared with the results of conventional NIL. In this study, the improvement in the reliability for results of thermal NIL has been achieved.

• 한국임상수의학회지
• /
• 제34권6호
• /
• pp.410-413
• /
• 2017

Composites of hydroxyapatite (HAp) and chitosan (CS) have been successfully used in bone healing in humans and animals. However, the characteristics of HAp and CS are different. Therefore, the effects of HAp/CS composites on canine bone formation could differ according to their ratio. This study investigated the therapeutic effects of different contents ratios (100, 80:20, 60:40 wt%) on bone defects in a canine model. Thirty intrabony cylindrical defects were created in the humeruses and femurs of 5 beagle dogs, and then the defects were implanted with different composites. The evaluations were performed using radiographs obtained at 10 weeks post-surgery and by histological findings. In radiographic evaluation including the grades of bone filling, periosteal and endosteal reactions, pure hydroxyapatite composite had a significant effect on bone filling, and chitosan containing the composites showed vigorous responses at the periosteum and endosteum. In histological findings, the defect implanted with pure hydroxyapatite had healed completely into mature bony tissue with an obvious osteon structure, and the defect implanted with chitosan containing the composites had the amount of fibrous connective tissue increased significantly within the cortical bone tissue. The results indicate that hydroxyapatite/chitosan composites are therapeutically useful, promoting effective bone healing in defects when the ratio of hydroxyapatite is high and enhanced fibrous connective tissue formation at the periosteum as more chitosan is added.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2015년도 추계 학술논문 발표대회
• /
• pp.87-88
• /
• 2015

A defect dispute surrounding an apartment building is in constant trouble, a defect consulting is necessary that objective and impartial for solving a defect. The defect dispute about a defect lawsuit is conducted in the order that filling of lawsuit, consulting order, defect inspecting, estimating a repairing cost, writing a consulting report, submitting a consulting report, and decision by court. Of these, a step of defect inspecting is extensively investigated an occurred defect that each defect index and type from each part and place. At this time, it is collected of many data and created many information. For this, it need to organize and manage. The study is a modeling of field investigation work process that second phase of defect inspecting step. A literature study is defined a work until level 2. This study is defined the work until level 3 to 4. In addition, the modeling can do for using a job name, a place to job, a job to do, and a person concerned about defect consulting case. The modeling is expected a contribution of improving a defect consulting process and systematizing a judgment standard.

• Carbon letters
• /
• 제16권3호
• /
• pp.198-202
• /
• 2015

Carbon-supported Pt catalyst systems containing defect adsorption sites on the anode of direct methanol fuel cells were investigated, to elucidate the mechanisms of H₂ dissociation and carbon monoxide (CO) poisoning. Density functional theory calculations were carried out to determine the effect of defect sites located neighboring to or distant from the Pt catalyst on H₂ and CO adsorption properties, based on electronic properties such as adsorption energy and electronic band gap. Interestingly, the presence of neighboring defect sites led to a reduction of H₂ dissociation and CO poisoning due to atomic Pt filling the defect sites. At distant sites, H₂ dissociation was active on Pt, but CO filled the defect sites to form carbon π-π bonds, thus enhancing the oxidation of the carbon surface. It should be noted that defect sites can cause CO poisoning, thereby deactivating the anode gradually.