• Archives of Plastic Surgery
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• 제39권3호
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• pp.257-260
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• 2012

This report describes the use of a tubularized random flap for the curative treatment of recurrent anterior urethral stricture. Under the condition of pendulous lithotomy and suprapubic cystostomy, the urethral stricture was removed via a midline ventral penile incision followed by elevation of the flap and insertion of an 18-Fr catheter. Subcutaneous buried interrupted sutures were used to reapproximate the waterproof tubularized neourethra and to coapt with the neourethra and each stump of the urethra, first proximally and then distally. The defect of the penile shaft was covered by advancement of the surrounding scrotal flap. The indwelling catheter was maintained for 21 days. A 9 month postoperative cystoscopy showed no flap necrosis, no mechanical stricture, and no hair growth on the lumen of the neourethra. The patient showed no voiding discomfort 6 months after the operation. The advantages of this procedure are the lack of need for microsurgery, shortening of admission, the use of only spinal anesthesia (no general anesthesia), and a relatively short operative time. The tubularized unilateral penile fasciocutaneous flap should be considered an option for initial flap urethroplasty as a curative technique.

• Geomechanics and Engineering
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• 제14권4호
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• pp.355-366
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• 2018

One of the significant problems in the design of onshore pipelines in seismic areas is their stability in case of liquefaction. Several model tests and numerical analyses allow investigating the behavior of pipelines when the phenomenon of liquefaction occurs. While experimental tests contribute significantly toward understanding the liquefaction mechanism, they are costly to perform compared to numerical analyses; on the other hand, numerical analyses are difficult to execute, because of the complexity of the soil behavior in case of liquefaction. This paper reports an overview of the existing computational methods to evaluate the stability of onshore pipelines in liquefied soils, with particular attention to the development of excess pore water pressures and the floatation of buried structures. The review includes the illustration of the mechanism of floating and the description of the available calculation methods that are classified in static and dynamic approaches. We also highlighted recent trends in numerical analyses. Moreover, for the static condition, referring to the American Petroleum Institute (API) Specification, we computed and compared the uplift safety factors in different cases that might have a relevant practical use.

• 박물관보존과학
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• 제6권
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• pp.17-29
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• 2005

출토복식(出土服食)이란 시신이 매장될 때 염습의 등과 함께 부장되는 것으로 발굴이나 이장 시 발견되는 피복류 일체를 말한다. 유물은 시신과 함께 땅속에서 지속적인 열화과정을 거쳤기 때문에 발견 당시 형태가 온전하더라도 매장환경과 다른 새로운 환경으로 인해 손상을 초래할 수 있다. 특히 미생물 번식이 용이하므로 수습 때부터 적절한 보관과 보존처리가 필요한 상황이다. 그러나 최근 급격한 국토개발 등으로 급증하는 출토복식은 인식과 전문처리인 부족으로 응급 보존처리 실시 예가 매우 적다. 이에 출토복식에 대하여 본 실험실에서 실시한 과학적 조사와 응급보존처리를 중심으로 서술하고자 한다.

• KSBB Journal
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• 제27권1호
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• pp.51-56
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• 2012

This research was to investigate the polyester preparation using waste ethylene glycol (EG) generated from the wastepaper pretreatment process. Waste EG was obtained from using EG five times repeatedly in the pretreatment of wastepaper. The hydroxyl value of the waste EG was 441 mg KOH/g and its composition was 0.68% cellulose, 6.5% hemicellulose, 6.1% lignin, and 86.7% EG. Maleic acid was used as carboxylic acid. The effect of reaction temperature and time except carboxyl group/hydroxyl group ratio on the crosslinkage of the prepared polyester was marginal. Citric acid, lithium hydroxide and dicumyl peroxide were used as additive or catalyst to enhance the crosslinkage of polyester. Among them, 10% of citric acid was found to be most effective. The crosslinkage was 86% when the polyester was prepared at an optimum condition such as $130^{\circ}C$ and 15 minutes, 1.5 of C/H ratio, and 10% of citric acid, and its insoluble percentage in boiling water for 6 hours was 47%. The weight loss of the prepared polyester was approximately 40% when it was buried in damp soil for 5 months, indicating that it is readily biodegradable. This results can provide some information for future development of wastepaper pretreatment by organic solvent.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전기물성,응용부문
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• pp.227-229
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• 2004

The corrosion rate of buried steel pipes for water works was investigated under soil environment. Steel pipe shows various characteristics caused by complicated environment condition of underground and especially the corrosion rate of it depends on the resistivity of soil controlled by content of water. In this paper, the corrosion behavior of steel pipe was observed by polarization test under soil and the silica sand in the water content range of 0-50%. Generally it is well known that the resistivity of soil decreased rapidly over 15% water content. In fact the corrosion rate, corrosion potential, and corrosion consumption (MPY) of steel pipe were shown very different aspects within 20% water content.

• 한국정밀공학회지
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• 제18권1호
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• pp.89-97
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• 2001

A microgyroscope, which vibrates in two orthogonal axes on the substrate plane, is designed and fabricated. The shuttle mass of the vibrating gyroscope consists of two parts. The one is outer shuttle mass which vibrates in driving mode guided by four folded springs attached to anchors. And the other is inner shuttle mass which vibrates in driving mode as the outer frame does and also can vibrate in sensing mode guided by four folded springs attached to the outer shuttle mass. Due to the directions of vibrating mode, it is possible to fabricate the gyroscope with simplified process by using polysilicon on insulator structure. Fabrication processes of the microgyroscope are composed of anisotropic silicon etching by RIE, gas-phase etching (GPE) of the buried sacrificial oxide layer, metal electrode formation. An eletromechanical model of the vibrating microgyroscope was modeled and bandwidth characteristics of the gyroscope operates at DC 4V and AC 0.1V in a vacuum chamber of 100mtorr. The detection circuit consists of a discrete sense amplifier and a noise canceling circuit. Using the evaluated electromechanical model, an operating condition for high performance of the gyroscope is obtained.

• 한국정보통신학회논문지
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• 제12권10호
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• pp.1890-1896
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• 2008

본 연구는 칩 표면에 수평 한 자기장을 검출하는 종형 Hall 소자를 바이폴라 기술로 제조하여 동작 및 잡음 특성을 조사하였다. P+ Isolation 댐을 설치한 소자(type B)가 설치하지 않는 소자(type A)보다 자기 감도는 약 1.2배 증가하였고, 역시 잡음도 증가하였다. 측정된 이 종형 Hall소자의 자기 검출 분해능은 f=1[KHz], 대역폭 1[Hz] 구동조건에서 type A는 약 $0.97[{\mu}T]$, type B는 $1.25[{\mu}T]$였다. 따라서 Hall 소자 구조 설계나 재료적인 면에서 볼 때, 낮은 잡음즉, 자기 검출분해능과 높은 감도 상관관계를 고려하여야 한다.

• Geomechanics and Engineering
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• 제19권3호
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• pp.283-293
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• 2019

Evaluating the stability of the excavation face of the cross-river shield tunnel with good accuracy is considered as a nonlinear and multivariable complex issue. Understanding the stability evaluation method of the shield tunnel excavation face is vital to operate and control the shield machine during shield tunneling. Considering the instability mechanism of the excavation face of the cross-river shield and the characteristics of this engineering, seven evaluation indexes of the stability of the excavation face were selected, i.e., the over-span ratio, buried depth of the tunnel, groundwater condition, soil permeability, internal friction angle, soil cohesion and advancing speed. The weight of each evaluation index was obtained by using the analytic hierarchy process and the entropy weight method. The evaluation model of the cross-river shield construction excavation face stability is established based on the idea point method. The feasibility of the evaluation model was verified by the engineering application in a cross-river shield tunnel project in China. Results obtained via the evaluation model are in good agreement with the actual construction situation. The proposed evaluation method is demonstrated as a promising and innovative method for the stability evaluation and safety construction of the cross-river shield tunnel engineerings.

• Steel and Composite Structures
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• 제38권1호
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• pp.79-86
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• 2021

Due to the complex geological conditions, a large number of high quality coal seams was buried in the western of China which cannot be mining in open-pit methods. The dynamic properties of that coal cannot be studied easily in real site for the complex working condition. The compound coal blocks made on the basis of the real situation were studied in the laboratory. The physical and mechanical properties of the compound coal blocks and the raw coal were contrasted by using the UCS tests. The results show that the compound coal blocks made by mixing coal powder, cement and water in proportion of 2.5:2:1 are the closest to that of standard raw coal. Then the propagation of strain waves and crushing effects on the coal were studied in the compound coal blocks by using the super dynamic strain test system and the numerical calculated method of ANSYS/LS-DYNA. The results show that the diameter of the crushing zone in the compound coal blocks was similar to that in the numerical results. The fractures distribution in laboratory tests also has a similar trend to the calculation results. The measured strain waves at the distance of 50 cm, 100 cm, and 150 cm from the center of the charge are mainly concerned at -1.0×104 με and have a similar trend as that in the numerical simulation.

• Computers and Concrete
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• 제29권2호
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• pp.69-79
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• 2022

For long underground box utility tunnels, post-tensioned precast concrete is often used. Between precast tunnel segments, sealed waterproof flexible joints are often specified. Fault displacement can lead to excessive deformation of the joints, which can lead to reduction in waterproofing due to diminished contact pressure between the sealant strip and the tunnel segment. This paper authenticates utilization of a finite element model for a prefabricated tunnel fault-crossing founded on ABAQUS software. In addition, material parameter selection, contact setting and boundary condition are reviewed. Analyzed under normal fault action are: the influence of fault displacement; buried depth; soil friction coefficient, and angle of crossing at the fault plane. In addition, distribution characteristics of the utility tunnel structure for vertical and longitudinal/horizontal relative displacement at segmented interface for the top and bottom slab are analyzed. It is found that the effect of increase in fault displacement on the splice joint deformation is significant, whereas the effects of changes in burial depth, pipe-soil friction coefficient and fault-crossing angle on the overall tunnel and joint deformations were not so significant.