• Title/Summary/Keyword: tubular structure

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Selective Cytotoxicity of New Platinum (II) Complex Containing 1,2-Diaminopropane (1,2-디아미노프로판을 배위자로 한 백금(II) 착체의 선택적 세포독성)

  • Rho, Young-Soo;Lee, Kyung-Tae;Chang, Sung-Goo;Jung, Jee-Chang
    • YAKHAK HOEJI
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    • v.42 no.5
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    • pp.494-499
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    • 1998
  • As part of a drug discovery program to discover more effective platinum-based anticancer drugs, a series of platinum complexes of 1,2-bis(diphenylphosphino)ethane(1,2-diaminopro pane)platinum(II)dinitrate (KHPC-070) has been evaluated in vitro against various tumor cell lines and normal kidney cells. The structure of this new compound was determined by elemental analysis, infrared spectroscopy (IR) and $^{13}carbon$ nuclear magnetic resonance (NMR). With the use of nine tumor cell lines, KHPC-070 exhibited a comparable cytotoxic to cisplatin. The cytotoxicity of KHPC-070 in normal cells was quite less than that of cisplatin using 3-(4.5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) and [$^3H$]-thymidine uptake tests in rabbit renal proximal tubular cells and human renal cortical cells. Based on these results, KHPC-070 is considered to have more selective cytotoxicity toward cancer cells than normal human/rabbit kidney cells.

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Flexural bearing capacity of diaphragm-through joints of concrete-filled square steel tubular columns

  • Rong, Bin;Liu, Rui;Zhang, Ruoyu;Chen, Zhihua;Apostolos, Fafitis
    • Steel and Composite Structures
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    • v.20 no.3
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    • pp.487-500
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    • 2016
  • In order to investigate the flexural bearing capacity of panel zone of diaphragm-through joint between concrete filled square steel tubular column and steel beam, four specimens were tested under static tension loads to study the mechanical properties and bearing capacity of diaphragm-through joints with a failure mode of panel zone. Finite element models of these specimens were developed to simulate the test and compare the predicted failure modes, load-displacement curves and bearing capacities with the experimentally observed. It was found that the tensile load from the steel beam flange is mainly shared by the square steel tube and the diaphragm. The diaphragm plastic zone appears along the cross-section lines enclosed by the square steel tube and the influence of steel beam web on the plastic zone of the steel tube is significant and cannot be neglected. Computational models of yield lines on square steel tube and diaphragm are established based on the distribution pattern of the plastic zone, and an analytical method for the evaluation of the bearing capacity of the joint is proposed. The theoretical results and the experimental data are compared and found in good agreement.

Fabrication and Characteristics of Anode-supported Tubular Solid Oxide Fuel Cell (연료극 지지체식 원통형 고체산화물 연료전지의 제조 및 특성)

  • Song, Keun-Sik;Song, Rak-Hyun;Ihm, Young-Eon
    • Korean Journal of Materials Research
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    • v.12 no.9
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    • pp.691-695
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    • 2002
  • A low temperature anode-supported tubular solid oxide fuel cell was developed. The anode-supported tube was fabricated using extrusion process. Then the electrolyte layer and the cathode layer were coated onto the anode tube by slurry dipping process, subsequently. The anode tube and electrolyte were co-fired at $140^{\circ}C$, and the cathode was sintered at $1200^{\circ}C$. The thickness and gas permeability of the electrolyte depended on the number of coating and the slurry concentration. Anode-supported tube was satisfied with SOFC requirements, related to electrical conductivity, pore structure, and gas diffusion limitations. At operating temperature of $800^{\circ}C$, open circuit voltage of the cell with gastight and dense electrolyte layer was 1.1 V and the cell showed a good performance of 450 mW/$\textrm{cm}^2$.

Design Optimization of Complex Loaded Tower Using Composite Materials in Off and On Shore (복합재료를 이용한 Off/On Shore에서의 복합하중을 받는 Tower에 대한 최적설계)

  • Son, Choong-Yul;Byun, Hyo-In;Kim, Sung-Jun
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2002.10a
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    • pp.289-294
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    • 2002
  • Unlike Tubular Steel Tower, This Composite Material Tower is a low-technology Component, whose design is easy to optimize, and which therefore during the design process-lends itself easily as an object for possible cost reduction at very little effort. This may come in useful as the cost of a tower usually significant part of the total cost of a structure. This paper is written by the Composite Materials Tower which loaded Complex loading in Off and On shore. This Composite Material Tower is made by the Method of Filament Winding, and the Component of Composite Material is used by the Roving RS220PE-535. When it loaded Complex trading, there is a results which is bigger than steel tower deflection. We controlled this 1a18e deflection by stiffeners which has thickness 20mm. At last, Off and On Shore Tower which used Composite Materials is compared with Off and On Shore Tower which used Steel.

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Single-walled carbon nanotubes directly-grown from orientated carbon nanorings

  • Tojo, Tomohiro;Inada, Ryoji;Sakurai, Yoji;Kim, Yoong Ahm
    • Carbon letters
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    • v.27
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    • pp.35-41
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    • 2018
  • Surfactant-wrapped separation methods of metallic and semiconducting single-walled carbon nanotubes (SWCNTs) can result in large changes in intrinsic physical and chemical properties due to electronic interactions between a nanotube and a surfactant. Our approach to synthesize SWCNTs with an electronic feature relied on utilizing carbon nanorings, [n] cycloparaphenylenes ([n]CPPs), which are the fundamental unit of armchair type SWCNTs (a-SWCNTs) that possess a metallic feature without any surfactants. To obtain long tubular structures from [n]CPPs, the host-guest complexes formed with well-aligned [n]CPP hosts and various fullerene guests on a silicon substrate were pyrolyzed under an ethanol gas flow at a high temperature with focused-ultraviolet laser irradiation. The pyrolyzed [n]CPPs were observed to transform from nanorings to tubular structures with 1.5-1.7 nm diameters corresponding to the employed diameter of [n]CPPs. Our approach suggests that [n]CPPs are useful for structure-controlled synthesis of SWCNTs.

Ultrastructure of the Gill of the Parrot fish, Oplegnathus fasciatus (돌돔 (Oplegnathus fasciatus) 아가미의 미세구조)

  • Kim, Jae-Won;Baeck, Gun-Wook
    • Applied Microscopy
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    • v.34 no.2
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    • pp.139-143
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    • 2004
  • The ultrastructure of the gills of Oplegnathus fasciatus was examined by means of light and transmission electron microscopes. The gills have primary and secondary filaments (lamellae). The following cells are identified and described : epithelial cell, pillar cell, chloride cell and mucose cell. The simple epithelial layer consists of squamous epithelium containing a large nucleus and the surface is covered with some of microridges. The lamella pillar structures are characterized by axial microtubules and lateral membrane interdigitations. Chloride cells contain a lot of mitochondria and specifically developed tubular systems. The rough endoplasimic reticulum and golgi complex, and some of mucous granules were observed in immature mucous cells. The mature mucous cells were AB-PAS positive, globular in shape, and had mucous granules of similar size with various electron densities.

A Sphaghetti Sign in the Abdominal Radiograph Consistent with Spleno-Systemic Shunts in a Cat

  • Oh, Donghyun;Hwang, Jaewoo;Yoon, Junghee;Choi, Mincheol
    • Journal of Veterinary Clinics
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    • v.37 no.4
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    • pp.227-230
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    • 2020
  • A 8-year-old spayed female Korean short-haired cat was presented with respiratory distress. CBC, serum chemistry analysis, plain radiography, and abdominal ultrasonography were performed. Besides hypertrophic cardiomyopathy (HCM) suspected by the thoracic radiograph, a tubular, tortuous soft tissue structure was detected at the region of the left retroperitoneal cavity on the abdominal radiograph. On the abdominal ultrasonography, a shunt vessel is identified caudo-lateral to the left kidney region. These findings are consistent with spleno-systemic shunts in cats. Furthermore, portal hypertension and diffuse hepatic lesion were also identified. Although the cause of a shunt vessel is not easy to diagnose, it is important to include spleno-systemic shunt into differential diagnosis list, when convoluted, tubular soft tissue opacity is seen on the digital radiography (DR). This report will allow clinicians to raise awareness of complications of portosystemic shunt (PSS) and better treat PSS suspected feline patients when the advanced modalities such as computed tomography and magnetic resonance imaging are not available.

Boundary Conditions and Fire Behavior of Concrete Filled Tubular Composite Columns

  • Rodrigues, Joao Paulo C.;Correia, Antonio J.M.;Kodur, Venkatesh
    • International Journal of High-Rise Buildings
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    • v.7 no.4
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    • pp.313-325
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    • 2018
  • Concrete-filled steel tubular (CFST) members are commonly used as composite columns in modern construction. However, the current guidelines for members' fire design (EN1994-1-2) have been proved to be unsafe in case the relative slenderness is higher than 0.5. In addition, the simplified design methods of Eurocode 4 are limited to circular and square CFST columns, while in practice columns with rectangular and elliptical hollow sections are being increasingly used because of their architectural aesthetics. In the last years a large experimental research has been carried out at Coimbra University on the topic. They have been tested concrete filled circular, square, rectangular and elliptical hollow columns with restrained thermal elongation. Some parameters such as the slenderness, the type of cross-section geometry as well as the axial and rotational restraint of the surrounding structure to the column have been tested in order to evaluate their influence on the fire resistance of such columns. In this paper it is evaluated the influence of the boundary conditions (pin-ended and semi-rigid end-support conditions) on the behavior of the columns in case of fire. In these tests it could not be seen a marked effect of the tested boundary conditions but it is believed that the increasing of rotational stiffness increases the fire resistance of the columns.

A robust approach in prediction of RCFST columns using machine learning algorithm

  • Van-Thanh Pham;Seung-Eock Kim
    • Steel and Composite Structures
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    • v.46 no.2
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    • pp.153-173
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    • 2023
  • Rectangular concrete-filled steel tubular (RCFST) column, a type of concrete-filled steel tubular (CFST), is widely used in compression members of structures because of its advantages. This paper proposes a robust machine learning-based framework for predicting the ultimate compressive strength of RCFST columns under both concentric and eccentric loading. The gradient boosting neural network (GBNN), an efficient and up-to-date ML algorithm, is utilized for developing a predictive model in the proposed framework. A total of 890 experimental data of RCFST columns, which is categorized into two datasets of concentric and eccentric compression, is carefully collected to serve as training and testing purposes. The accuracy of the proposed model is demonstrated by comparing its performance with seven state-of-the-art machine learning methods including decision tree (DT), random forest (RF), support vector machines (SVM), deep learning (DL), adaptive boosting (AdaBoost), extreme gradient boosting (XGBoost), and categorical gradient boosting (CatBoost). Four available design codes, including the European (EC4), American concrete institute (ACI), American institute of steel construction (AISC), and Australian/New Zealand (AS/NZS) are refereed in another comparison. The results demonstrate that the proposed GBNN method is a robust and powerful approach to obtain the ultimate strength of RCFST columns.

Fine Structural Study on the Salivary Glands in the Pine Moth, Dendrolimus spectabilis Butler at the Last Larval Period (솔나방(Dendrolimus spectabilis Butler) 종령유충(終齡幼蟲)의 타액선(唾液腺)에 관한 미세구조적(微細構造的) 연구(硏究))

  • Baek, Seung-Bum;Moon, Myung-Jin;Kim, Woo-Kap
    • Applied Microscopy
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    • v.18 no.2
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    • pp.153-166
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    • 1988
  • The fine structure of the salivary glands of the pine moth, Dendrolimus spectabilis Butler, at the last larval period is observed using light and electron microscopes. The moths have single paired tubular salivary glands which openings are connected to the oral cavity through the upper jaw. By the external morphology and its functions, the glands are subdivided into three regions which are anterior reabsorptive region, middle storage region and posterior secretory region. Along the inner canal of the salivary gland two columns of the large glandular cells are connected each other and oriented to ring-like forms. By this cellular orientation, the glands have long and large tubular structure. From anterior to posterior region large nuclei of the glands are ramified like twigs of the tree, and in the cytoplasm of the cell numerous mitochondria and vacuoles are seen. Moreover, basal plasma membranes of the gland cells are heavily infolded. The anterior region of the glands keeps several characteristics related to the reabsorption of the material from the inner cavity to the glandular cells whereas, main salivary material is synthesized and secreted through the long and convoluted posterior region. The apical plasma membranes of the cells are the most heavily invaginated at the posterior regoin, but trachea and tracheoles are distributed only at the middle and posterior regions. In the cytoplasm of the middle region Golgi complexes appeared at the vicinity of the vesicles, and at the posterior region of the salivary glands multivesicular bodies are also observed.

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