• Title/Summary/Keyword: Weak parts

Search Result 260, Processing Time 0.028 seconds

Signaling Smartness: Smart Cities and Digital Art in Public Spaces

  • Littwin, Karolina;Stock, Wolfgang G.
    • Journal of Information Science Theory and Practice
    • /
    • v.8 no.1
    • /
    • pp.20-32
    • /
    • 2020
  • Informational urbanism is a new research area in information science. In this study, art history joins informational urbanism: Are digital artworks in public urban spaces recognized as essential assets of a smart city? We employed case study research, working with the example of the huge digital media façade of the Arthouse Graz as an artwork in a public space. In a mixed-methods approach, we asked passers-by and interviewed experts on Graz as a smart city and on the Arthouse's role concerning the image of Graz as a smart city. The research found strong hints that indeed digital artworks with large screens or media façades at public spaces are parts of a city's weak location factors as well as of the city's urban structure and may symbolize the city's smartness. A practical implication of this finding is that artists, computer and information scientists, city planners, and architects should include interactive contemporary digital art into city spaces in order to demonstrate the city's way towards knowledge society.

Physical Characteristics and Antioxidative Capacity of Major Seaweeds

  • Han, Kyung-Hee;Lee, Eun-Joo;Sung, Mi-kyung
    • Preventive Nutrition and Food Science
    • /
    • v.4 no.3
    • /
    • pp.180-183
    • /
    • 1999
  • Seaweeds is a rich sources of dietary fibers exerting a number of physiological properties. However, the reported dietary fiber contents of seaweeds are not consistent and vary widely. Also. a limited number of studies on the biological effects of specific seaweeds have been reported. In this study, water-holding capacity, viscosity and antixidantive activity of major dietary seaweeds were measured to assess their physiological effects. Results showed that total dietary fiber contents ranged from 28 to 51% of dried weight, and large proportions of dietary fiber were insoluble fibers. Water-holding capacity was highest in sea mustard being 1310% , while laver, sea tangle, and green laver exhibited 943, 854 and 815%, respectively. The viscosity of seaweed samples was 20 to 40 cP in sea mustard and sea tangle, while laver and green laver possessed much lower values. All seaweed samples revealed a weak, albeit significant electron donating ability. Also, lipid peroxidation was reduced by 7 to 18%. However, there was no difference in antioxidative activity among seaweeds and sample concernations used. These results imply that most commonly used seaweeds possibly exert parts of their physiological effects through their water-holding, gel-forming , and/or antioxidative activities.

  • PDF

Effects of Insert Materials of Retaining Ring on Polishing Finish in Oxide CMP (산화막 CMP에서 리테이닝 링의 인서트 재질이 연마정밀도에 미치는 영향)

  • Park, Ki-Won;Park, Dong-Sam
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.18 no.8
    • /
    • pp.44-50
    • /
    • 2019
  • CMP is the most critical process in the manufacture of silicon wafers, and the use of retaining rings, which are consumable parts used in CMP equipment, is increasingly important. Since the retaining ring is made of plastic, it is not only weak in strength but also has the problem of taking a long time for the flattening operation of the ring itself performed before the CMP process, and of the imbalance of force due to bolt tightening causing uneven wear. In order to solve this problem, the retaining ring and the insert ring are integrally used, and the flatness of the retaining ring may be affected depending on the material of the insert ring. Also, the residual stress generated in the manufacturing process of the insert ring may cause distortion of the ring, which may adversely affect the precision polishing. In this study, when the insert ring is made of Zn or STS304, the thickness variation and the flatness of the retaining ring are compared and, finally, the material removal rate is analyzed by polishing the wafer by the oxide CMP process. Through these experiments, the effects of the insert ring material on the polishing accuracy of the wafers were investigated.

Experimental study on high gravity dam strengthened with reinforcement for seismic resistance on shaking table

  • Wang, Mingming;Chen, Jianyun;Fan, Shuli;Lv, Shaolan
    • Structural Engineering and Mechanics
    • /
    • v.51 no.4
    • /
    • pp.663-683
    • /
    • 2014
  • In order to study the dynamic failure mechanism and aseismic measure for high concrete gravity dam under earthquake, the comparative models experiment on the shaking table was conducted to investigate the dynamic damage response of concrete gravity dam with and without the presence of reinforcement and evaluate the effectiveness of the strengthening measure. A new model concrete was proposed and applied for maintaining similitude with the prototype. A kind of extra fine wires as a substitute for rebar was embedded in four-points bending specimens of the model concrete to make of reinforced model concrete. The simulation of reinforcement concrete of the weak zones of high dam by the reinforced model concrete meets the similitude requirements. A tank filled with water is mounted at the upstream of the dam models to simulate the reservoir. The Peak Ground Acceleration (PGA) that induces the first tensile crack at the head of dam is applied as the basic index for estimating the overload capacity of high concrete dams. For the two model dams with and without strengthening tested, vulnerable parts of them are the necks near the crests. The results also indicate that the reinforcement is beneficial for improving the seismic-resistant capacity of the gravity dam.

A study on electronic braking expansion simulation of synchronous motor applied by Matlab & PSPICE (Matlab과 PSPICE를 이용한 동기전동기의 전기 제동 확대 시뮬레이션에 관한 연구)

  • Na, Seung-Kwon;Ku, Gi-Jun
    • Journal of the Korea Society of Computer and Information
    • /
    • v.17 no.2
    • /
    • pp.87-94
    • /
    • 2012
  • Mechanical break system used in train, that mixed air break & electronic break system. this system suggest lots of ways for modify efficiency and solution of environmental problems due to recently intend to green growth. The mechanical break system has environmental & economical problem. Environmental sides(problem) are dust and noise etc and economical sides(problem) are replaced the spare parts that are breaking shoe and lining ect. For compensate those kind of weak points, we needs a wide territories of electronic break which is from high speed range to stop. This research is estimated the load torque due to an incline and stop the train method also check the characteristic of stop the train to estimate a torque follow the sharp drop.

A Study on the Structural Analysis and Design Verification of Variable Swash Plate Piston Pump Case for Wheeled Armored Vehicle (차륜형 장갑차용 가변형 사판식 피스톤 펌프 케이스의 구조해석 및 설계검증에 관한 연구)

  • Choi, Seong Woong;Kim, Yong Seok;Yang, Soon Yong
    • Journal of Drive and Control
    • /
    • v.16 no.2
    • /
    • pp.43-50
    • /
    • 2019
  • The objective of this study was to reverse engineer a swash plate type piston pump mounted on a wheeled armored vehicle and to analyze the structure of the pump case. From the analysis, the weak parts were identified and corrected in the final design. Each element corresponding to the piston pump case was analyzed. The analytical method was given static boundary conditions, load conditions and confirmed displacement, strain, stress, and safety factor. Plastic deformation and damage were also confirmed and the component elements redesigned through structural analysis Structural analysis and vibration analysis were carried out for the components of the piston pump case. The piston pump model was finally modified by structural analysis and vibration analysis results for each component assembly, and a prototype was designed. Durability test and environmental test were carried out and the test results satisfied all of the requirements. Therefore, the analytical method presented in this study can be utilized as a methodology for element component design in the development of various piston pumps.

Variation in wind load and flow of a low-rise building during progressive damage scenario

  • Elshaer, Ahmed;Bitsuamlak, Girma;Abdallah, Hadil
    • Wind and Structures
    • /
    • v.28 no.6
    • /
    • pp.389-404
    • /
    • 2019
  • In coastal regions, it is common to witness significant damages on low-rise buildings caused by hurricanes and other extreme wind events. These damages start at high pressure zones or weak building components, and then cascade to other building parts. The state-of-the-art in experimental and numerical aerodynamic load evaluation is to assume buildings with intact envelopes where wind acts only on the external walls and correct for internal pressure through separate aerodynamic studies. This approach fails to explain the effect of openings on (i) the external pressure, (ii) internal partition walls; and (iii) the load sharing between internal and external walls. During extreme events, non-structural components (e.g., windows, doors or rooftiles) could fail allowing the wind flow to enter the building, which can subject the internal walls to lateral loads that potentially can exceed their load capacities. Internal walls are typically designed for lower capacities compared to external walls. In the present work, an anticipated damage development scenario is modelled for a four-story building with a stepped gable roof. LES is used to examine the change in the internal and external wind flows for different level of assumed damages (starting from an intact building up to a case with failure in most windows and doors are observed). This study demonstrates that damages in non-structural components can increase the wind risk on the structural elements due to changes in the loading patterns. It also highlights the load sharing mechanisms in low rise buildings.

Pseudo-dynamic and cyclic loading tests on a steel-concrete vertical hybrid structure

  • Wang, Bo;Wu, Tao;Dai, Huijuan;Bai, Guoliang;Wu, Jian
    • Earthquakes and Structures
    • /
    • v.17 no.4
    • /
    • pp.399-409
    • /
    • 2019
  • This paper presents the experimental investigations on the seismic performance of a peculiar steel-concrete vertical hybrid structural system referred to as steel truss-RC tubular column hybrid structure. It is typically applied as the supporting structural system to house air-cooled condensers in thermal power plants (TPPs). Firstly, pseudo-dynamic tests (PDTs) are performed on a scaled substructure to investigate the seismic performance of this hybrid structure under different hazard levels. The deformation performance, deterioration behavior and energy dissipation characteristics are analyzed. Then, a cyclic loading test is conducted after the final loading case of PDTs to verify the ultimate seismic resistant capacity of this hybrid structure. Finally, the failure mechanism is discussed through mechanical analysis based on the test results. The research results indicate that the steel truss-RC tubular column hybrid structure is an anti-seismic structural system with single-fortification line. RC tubular columns are the main energy dissipated components. The truss-to-column connections are the structural weak parts. In general, it has good ductile performance to satisfy the seismic design requirements in high-intensity earthquake regions.

Microstructures and Textures of Electrodeposited Ni/Invar Bimetal (전주도금으로 제조된 Ni/Invar 바이메탈의 미세조직과 집합조직)

  • Kang, Ji Hoon;Seo, Jeong Ho;Park, Yong Bum
    • Korean Journal of Metals and Materials
    • /
    • v.46 no.7
    • /
    • pp.420-426
    • /
    • 2008
  • By using electrodeposition, we developed a new method to produce Ni/Invar bimetal sheets, which have been used for the present study to investigate the texture evolution during annealing. The grains of electrodeposited Ni were columnar, while those of electrodeposited Fe-Ni alloy were nanocrystalline. These different parts of the bimetal underwent different evolution of textures and microstructures during annealing. In the nanocrystalline Invar, the as-deposited textures were of fiber-type characterized by strong <100>//ND and weak <111>//ND components, and the occurrence of grain growth resulted in the strong development of the <111>//ND fiber texture with the minor <100> // ND components. On the other hand, in the columnar-structured Ni part, the as-deposited <110>//ND fiber texture transformed to the <112>//ND fiber texture due to recrystallization occurring above $550^{\circ}C$. The development of microtextures which took place during annealing in the Ni/Invar interfacial regions was investigated by using the OIM analysis, and discussed in terms of the effect of atomic diffusion across the interfaces.

Constructional Verification Evaluation for Securing the Field Quality of Composite Membrane Waterproofing Material (멤브레인 복합 방수재의 현장품질 안정성 확보를 위한 시공성 실증 평가 연구)

  • Kim, Meong-Ji;Lee, Sang-Wook;Kim, Soo-Yeon;Oh, Sang-Keun
    • Journal of the Korea Institute of Building Construction
    • /
    • v.21 no.1
    • /
    • pp.87-95
    • /
    • 2021
  • In this study, seven companies(A~G) designated as new construction technology selected and evaluated KS F 2622: Method of test for performance evaluation of membrane roofing systems that are similar to field application conditions. As a result of the test, it was confirmed that although all test specimens exceeded KS standards in the basic physical, it was difficult to obtain field quality performance in weak areas such as joints and vertical parts of the adhesive coating method in water-tightness, sagging resistance, swelling resistance tests except for fatigue(crack behavior) tests.