• Title/Summary/Keyword: Tubular

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Comparative Study on Continuous Ethanol Fermentation by Immobilized Tubular Fermentor (고정화된 효모로 충전된 관형발효기에서의 에탄올 연속발효)

  • 서근학;최명호;송승구
    • Microbiology and Biotechnology Letters
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    • v.16 no.3
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    • pp.205-212
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    • 1988
  • The immobilized cell tubular tormentor was prepared by wood chips or alginate gel. Investigations of characterization of the performance of ethanol fermentation in the immobilized cell tubular tormentor were undertaken and the results were compared with those of other tormentors. The immobilized cell tormentor packed with alginate gel showed much higher ethanol productivity than that with wood chip. It was concluded that the immobilized cell tubular tormentor packed with alginate gel might offer better perspectives for continuous ethanol production than that with wood chip.

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Tubular Structures on the Guticle of Two Gordius Species (Nematomprpha, Gordopodea, Gprdoodae_ from Korea and New Zealand (한국 및 뉴질랜드산 철선충류(유선형동물문, 철선충목, 철선충과) 2종의 표피 관상구조)

  • Andreas Schmidt-Rhaesa;Alexandder Kieneke;Daniel Muschiol;Chung, Pyung-Rim
    • Animal Systematics, Evolution and Diversity
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    • v.17 no.2
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    • pp.165-169
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    • 2001
  • We describe tubular structures on the cuticle of two representatives of the genus Gordius by scanning electron microscopy. One female from Korea could not be identified further while a male from New Zealand belonged to Gordius paranensis. Other male specimens of G. paranensis did not show tubular structures or the corresponding pores on the cuticle. Therefore it is assumed that tubular structures are not species-specific structures, but also no artifacts or contaminations. They might be glandular products, but this has to be verified by further documentations and investigation of the inner structure of it.

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Tubular Colonic Duplication Presenting as Rectovestibular Fistula

  • Karkera, Parag J.;Bendre, Pradnya;D'souza, Flavia;Ramchandra, Mukunda;Nage, Amol;Palse, Nitin
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.18 no.3
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    • pp.197-201
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    • 2015
  • Complete colonic duplication is a very rare congenital anomaly that may have different presentations according to its location and size. Complete colonic duplication can occur in about 15% of all gastrointestinal duplications. Double termination of tubular colonic duplication in the perineum is even more uncommon. We present a case of a Y-shaped tubular colonic duplication which presented with a rectovestibular fistula and a normal anus. Radiological evaluation and initial exploration for sigmoidostomy revealed duplicated colons with a common vascular supply. Endorectal mucosal resection of theduplicated distal segment till the colostomy site with division of the septum of the proximal segment and colostomy closure proved curative without compromise of the continence mechanism. Tubular colonic duplication should always be ruled out when a diagnosis of perineal canal is considered in cases of vestibular fistula alongwith a normal anus.

Fabrication and Performance Evaluation of Tubular Solid Oxide Fuel Cells Stack (원통형 고체산화물 연료전지 스택 제작 및 성능평가)

  • Kim, Wanje;Lee, Seungbok;Song, Rakhyun;Park, Seokjoo;Lim, Takhyoung;Lee, Jongwon
    • Transactions of the Korean hydrogen and new energy society
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    • v.24 no.6
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    • pp.467-471
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    • 2013
  • In present work, optimized the manufacturing process of anode-supported tubular SOFCs cell and stack were studied. For this purpose, we first developed a high performance tubular SOFC cell, and then made electrical connection in series to get high voltage. The gas sealing was established by attaching single cells to alumina jig with ceramic bond. Through these process, we can obtain such high OVP as around 15V, which means that the electrical connection and gas sealing were optimized. Finally we developed a new tubular SOFC stack which shows a maximum power of 65W @ $800^{\circ}C$.

Nonlinear Iterative Solution for Adhesively Bonded Tubular Single Lap Joints with Nonlinear Shear Properties (튜브형 단면겹치기 접착조인트의 비선형 반복연산해에 관한 연구)

  • 이수정;이대길
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.7
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    • pp.1651-1656
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    • 1995
  • The adhesively bonded tubular single lap joint shows large nonlinear behavior in the loaddisplacement relation, because structural adhesives for the joint are usually rubber toughened, which endows adhesives with nonlinear shear properties. since the majority of load transfer of the adhesively bonded tubular single lap joint is accomplished by the nonlinear behavior of the adhesive, its torque transmission capability should be calculated incorporating nonlinear shear properties. However, both the analytic and numerical analyses become complicated if the nonlinear shear properties of the adhesive are included during the calculation of torque transmission capabilities. In this paper, in order to obtain the torque transmission capabilities easily, an iterative solution which includes the nonlinear shear properties of the adhesive was derived using the analytic solution with the linear shear properties of the adhesive. Since the iterative solution can be obtained very fast due to its simplicity, it has been found that it can be used in the design of the adhesively bonded tubular single lap joint.

Multi-response optimization of crashworthiness parameters of bi-tubular structures

  • Vinayagar, K.;Kumar, A. Senthil
    • Steel and Composite Structures
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    • v.23 no.1
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    • pp.31-40
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    • 2017
  • This article aims at presenting multi objective optimization of parameters that affect crashworthiness characteristics of bi-tubular structures using Taguchi method with grey relational analysis. To design the experiments, the $L_9$ orthogonal array has been used and based on that, the inner tubes have been fabricated by varying the three influence factors such as reference diameter, length difference and numbers of sides of the polygon with three levels, but all the outer cylinders have the same diameter and length 90 mm and 135 mm respectively. Then, the tailor made bi-tubular steel structures were subjected into quasi static axial compression. From the test results it is found that the crushing behaviors of bi-tubular structures with different combinations were fairly significant. The important responses (crashworthiness indicators) specific energy absorption and crush force efficiency have been evaluated from load - displacement curve. Finally optimal levels of parameters were identified using grey relational analysis, and significance of parameters was determined by analysis of variance. The optimum crashworthiness parameters are reference diameter 80 mm, length difference 0 mm and number of sides of polygon is 3, i.e., triangle within the selected nine bi-tube combinations.

A Study on Welding Distortion and Residual Stress for Tubular Welded Joint (튜브 용접부의 용접변형 및 잔류응력에 관한 연구)

  • Jin, Hyung-Kook;Shin, Sang-Beom;Lee, Dong-Ju;Park, Dong-Hwan
    • Journal of Welding and Joining
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    • v.30 no.5
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    • pp.51-56
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    • 2012
  • The purpose of this study is to evaluate the distortion and the residual stress of GTA tubular welds between tube and head. In order to do it, the heat input model for GTA welding process was first developed by experiment and FE analyses. The welding distortion and the residual stress distribution of the tubular welds according to welding pass and various restraint degrees were evaluated by using FEA with the heat input model. From FEA results, it was found that the residual stress and the radial distortion at the weld toe of tube part decrease with a decrease in the number of welding pass. However, the maximum residual stresses in each direction of tubular welds are almost constant regardless of the external restraint degree. It was mainly due to the high internal restraint of the welds.

A Study about Applicability of Treatment for Water Treatment Residual Sludge Using Crossflow Tubular Membrane System (정수장 배출수 처리를 위한 Crossflow 관형막 여과 공정의 운전 적용에 관한 연구)

  • Kim, Young Hoon;Kim, Kwan Yeop;Kim, Ji Hoon;Lee, Yong Soo;Lee, Eui Jong;Eom, Jung Yeol;Kim, Hyung Soo;Hwang, Sun Jin
    • Journal of Korean Society of Water and Wastewater
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    • v.23 no.4
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    • pp.499-505
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    • 2009
  • Many other countries have investigated the residual sludge treatment process to save the existing water resource and produce the high suspended solid concentration sludge. There are various methods for concentrating residual sludge, but the membrane system has received the most interest for its efficiency. The objective of this study was to evaluate the application of membrane filtration system for the residual sludge treatment. The experiment equipment was composed of Lab scale Crossflow tubular membrane filtration system. Generally, crossflow operation mode demands high electric cost mainly for the pump energy. So to cut off electric cost, very low Crossflow velocity was used in this experiment. Results confirmed that suspended solid concentration of residual sludge could be concentrated to 57,000mg/L in low Crossflow velocity tubular membrane system,. This concentration can be directly injected into the dehydrator. Based on the results, we know that the Crossflow tubular membrane system should be replaced conventional residual sludge treatment system.

Tubular-shaped ZnO Crystals by Thermal Evaporation Technique in Air (공기 중에서 열증발법에 의하여 제작된 튜브 형상의 ZnO 결정)

  • Lee, Jung-Hun;Lee, Geun-Hyoung;Nahm, Choon-Woo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.27 no.3
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    • pp.141-145
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    • 2014
  • Tubular-shaped ZnO crystals were synthesized by thermal evaporation technique under air atmosphere. Mixture of Zn and Mg powder was used as the source material. The thermal evaporation and oxidation of Zn/Mg mixture were carried out for 1 hr at $1,000^{\circ}C$ and $1,200^{\circ}C$ under in air under atmospheric pressure. When only Zn powder was used as a source material, tetrapod-shaped ZnO crystals were synthesized. This provides that Mg played a key role in the formation of the tubular-shaped crystals. SEM images showed that the tubular-shaped ZnO crystals grew along [0001] direction. XRD spectrum revealed that the ZnO tubes had hexagonal wurtzite structure. Two emission peaks at 380 nm and 510 nm were observed in the room temperature cathodoluminescence spectrum.

Fire resistance of high strength concrete filled steel tubular columns under combined temperature and loading

  • Tang, Chao-Wei
    • Steel and Composite Structures
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    • v.27 no.2
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    • pp.243-253
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    • 2018
  • In recent years, concrete-filled box or tubular columns have been commonly used in high-rise buildings. However, a number of fire test results show that there are significant differences between high strength concrete (HSC) and normal strength concrete (NSC) after being subjected to high temperatures. Therefore, this paper presents an investigation on the fire resistance of HSC filled steel tubular columns (CFTCs) under combined temperature and loading. Two groups of full-size specimens were fabricated to consider the effect of type of concrete infilling (plain and reinforced) and the load level on the fire resistance of CFTCs. Prior to fire test, a constant compressive load (i.e., load level for fire design) was applied to the column specimens. Thermal load was then applied on the column specimens in form of ISO 834 standard fire curve in a large-scale laboratory furnace until the set experiment termination condition was reached. The results demonstrate that the higher the axial load level, the worse the fire resistance. Moreover, in the bar-reinforced concrete-filled steel tubular columns, the presence of rebars not only decreased the spread of cracks and the sudden loss of strength, but also contributed to the load-carrying capacity of the concrete core.