• 제목/요약/키워드: research excellence

검색결과 487건 처리시간 0.04초

Burst strength behaviour of an aging subsea gas pipeline elbow in different external and internal corrosion-damaged positions

  • Lee, Geon Ho;Pouraria, Hassan;Seo, Jung Kwan;Paik, Jeom Kee
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제7권3호
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    • pp.435-451
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    • 2015
  • Evaluation of the performance of aging structures is essential in the oil and gas industry, where the inaccurate prediction of structural performance can have significantly hazardous consequences. The effects of structure failure due to the significant reduction in wall thickness, which determines the burst strength, make it very complicated for pipeline operators to maintain pipeline serviceability. In other words, the serviceability of gas pipelines and elbows needs to be predicted and assessed to ensure that the burst or collapse strength capacities of the structures remain less than the maximum allowable operation pressure. In this study, several positions of the corrosion in a subsea elbow made of API X42 steel were evaluated using both design formulas and numerical analysis. The most hazardous corrosion position of the aging elbow was then determined to assess its serviceability. The results of this study are applicable to the operational and elbow serviceability needs of subsea pipelines and can help predict more accurate replacement or repair times.

Ultimate strength performance of Northern sea going non-ice class commercial ships

  • Park, Dae Kyeom;Paik, Jeom Kee;Kim, Bong Ju;Seo, Jung Kwan;Li, Chen Guang;Kim, Do Kyun
    • Structural Engineering and Mechanics
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    • 제52권3호
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    • pp.613-632
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    • 2014
  • In the early design stage of ships, the two most important structural analyses are performed to identify the structural capacity and safety. The first step is called global strength analysis (longitudinal strength analysis or hull girder strength analysis) and the second step is local buckling analysis (stiffened panel strength analysis). This paper deals with the ultimate strength performance of Arctic Sea Route-going commercial ships considering the effect of low temperature. In this study, two types of structural analyses are performed in Arctic sea conditions. Three types of ship namely oil tanker, bulk carrier and container ship with four different sizes (in total 12 vessels) are tested in four low temperatures (-20, -40, -60 and $-800^{\circ}C$), which are based on the Arctic environment and room temperature ($20^{\circ}C$). The ultimate strength performance is analysed with ALPS/HULL progressive hull collapse analysis code for ship hulls, then ALPS/ULSAP supersize finite element method for stiffened panels. The obtained results are summarised in terms of temperature, vessel type, vessel size, loading type and other effects. The important insights and outcomes are documented.

부식된 해저 원유 파이프라인의 사용적합성 평가 (Serviceability Assessment of Corroded Subsea Crude Oil Pipelines)

  • 최옥석;김동우;서정관;하연철;김봉주;백점기
    • 대한조선학회논문집
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    • 제52권2호
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    • pp.153-160
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    • 2015
  • Pipelines are one of the most important structures in subsea equipment. It is the main equipment for transportation of crude oil and natural gas to the downstream facilities. Crude oil and natural gas leak will be carry out not only political and financial issues but also pollution to the environment. Inaccurate predictions of corrosion behavior will make hazardous consequences. The serviceability assessment of corroded structures is essential especially for subsea pipelines. As corrosion is concerned, the effects of failure due to significant reduction will make it hard to the pipeline operator to maintain the serviceability of pipelines. In this paper, the serviceability assessment of corroded crude oil pipeline is performed using the industry design code (Shell92, DNV RP F101, ASME B31G, BS 7910, PCORRC) and FEA depending on corrosion area. In last step, the future integrity of the subsea crude oil pipeline is assessed to predict the remaining year in service of crude oil pipelines.

Inhibition of Proliferation of Cervical and Leukemic Cancer Cells by Penicillin G

  • Banerjee, Aditya;Dahiya, Meetu;Anand, M.T.;Kumar, Sudhir
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권3호
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    • pp.2127-2130
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    • 2013
  • Cancer, despite all the efforts, still causes one in five deaths worldwide. Surgery, chemotherapy and radiotherapy provide inadequate protection and instead affect normal cells along with cancer cells. The search for cancer cures from natural products (plants and animals) has been practice for over a decade and the use of purified chemical to treat cancer still continues. Several studies have been undertaken during last three decades to find the anti-cancerous property of various plant extract and toxins secreted by animals and micro-organism. These lead to the discovery of several promising molecule having anticancer activity, some of which are in clinical trial and may emerged to be a potential future drug in cancer therapy. In this study we have used penicillin to evaluate its anti-cancer activity. It shown significant effects at cellular and molecular levels against growth of HeLa and K562 cell lines.

A Study on Developing the Teacher Education Program for Mathematical Excellence

  • Kim, Soo-Hwan
    • 한국수학교육학회지시리즈D:수학교육연구
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    • 제7권4호
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    • pp.235-246
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    • 2003
  • To develop the content and form of the teacher education program for mathematical excellence, we reviewed several teacher education programs. CGI is an excellent model for teacher education program for mathematical excellence. We developed the 12 teacher education programs based on mathematical tasks developed for the gifted children and have applied them to teacher education. It is not so difficult to develop more programs, because we have made a lot of tasks for the gifted in mathematics for 8 years. Wooden Die for Drinking Game which is one of 12 programs is introduced in this article.

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Occurrence of Thermophilic Campylobacter spp. Contamination on Vegetable Farms in Malaysia

  • Chai, L.C.;Ghazali, F.M.;Bakar, F.A.;Lee, H.Y.;Suhaimi, L.R.A.;Talib, S.A.;Nakaguchi, Y.;Nishibuchi, M.;Radu, S.
    • Journal of Microbiology and Biotechnology
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    • 제19권11호
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    • pp.1415-1420
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    • 2009
  • The aim of the present study was to examine the prevalence of thermophilic Campylobacter spp. (Campylobacter jejuni and Campylobacter coli) in soil, poultry manure, irrigation water, and freshly harvested vegetables from vegetable farms in Malaysia. C. jejuni was detected in 30.4% and 2.7% of the soil samples, 57.1 % and 0% of the manure samples, and 18.8% and 3% of the vegetable samples from farm A and farm B, respectively, when using the MPN-PCR method. Campylobacter spp. was not found in any of the irrigation water samples tested. Therefore, the present results indicate that the aged manure used by farm A was more contaminated than the composted manure used by farm B. Mostly, the leafy and root vegetables were contaminated. C. coli was not detected in any of the samples tested in the current study. Both farms tested in this study were found to be contaminated by campylobacters, thereby posing a potential risk for raw vegetable consumption in Malaysia. The present results also provide baseline data on Campylobacter contamination at the farm level.

Fatigue modeling of chopped strand mat/epoxy composites

  • Shokrieh, M.M.;Esmkhania, M.;Taheri-Behrooz, F.
    • Structural Engineering and Mechanics
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    • 제50권2호
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    • pp.231-240
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    • 2014
  • In the present research, fatigue behavior of chopped strand mat/epoxy composites has been studied with two different techniques. First, the normalized stiffness degradation approach as a well-known model for unidirectional and laminated composites was utilized to predict the fatigue behavior of chopped strand mat/epoxy composites. Then, the capability of the fatigue damage accumulation model for chopped strand mat/epoxy composites was investigated. A series of tests has been performed at different stress levels to evaluate both models with the obtained results. The results of evaluation indicate a better correlation of the normalized stiffness degradation technique with experimental results in comparison with the fatigue damage accumulation model.

Flexural fatigue modeling of short fibers/epoxy composites

  • Shokrieh, M.M.;Haghighatkhah, A.R.;Esmkhani, M.
    • Structural Engineering and Mechanics
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    • 제64권3호
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    • pp.287-292
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    • 2017
  • In the present research, an available flexural stiffness degradation model was modified and a new comprehensive model called "X-NFSD" was developed. The X-NFSD model is capable of predicting the flexural stiffness degradation of composite specimen at different states of stresses and at room temperature. The model was verified by means of different experimental data for chopped strand mat/epoxy composites under displacement controlled bending loading condition at different displacements and states of stresses. The obtained results provided by the present model are impressively in very good agreement with the experimental data and the mean value of error of 5.4% was achieved.

폭발 하중을 받는 보강된 방폭벽의 동적 구조 응답 특성에 관한 연구 (Dynamic Structural Response Characteristics of Stiffened Blast Wall under Explosion Loads)

  • 김상진;손정민;이종찬;리춘보;성동진;백점기
    • 대한조선학회논문집
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    • 제51권5호
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    • pp.380-387
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    • 2014
  • Piper Alpha disaster drew attention to the damage likely to arise from explosions and fires on an offshore platform. And great concerns have been increased to prevent these hazards. Blast wall is one of the passive safety systems; it plays a key part of minimizing the consequences. However, a buckling due to explosion loads is a factor which can reduce the strength of blast wall. The buckling often occurs between web and flange at the center of blast wall. This study aims to find a solution for reinforcing its strength by installing a flat plate at the spot where the buckling occurs. First of all, ANSYS finite element method is adopted to numerically compute the structural resistance characteristic of blast wall by using a quasi-static approach. Sequentially, the impact response characteristics of blast wall are investigated the effect on thickness of flat plate by using ANSYS/LS-DYNA. Finally, pressure-impulse diagrams (P-I diagram) are presented to permit easy assessment of structural response characteristics of stiffened blast wall. In this study, effective use is made to increase structural intensity. of blast wall and acquired important insights have been documented.

Macrophage Migration Inhibitory Factor: a Potential Marker for Cancer Diagnosis and Therapy

  • Babu, Spoorthy N.;Chetal, Gaurav;Kumar, Sudhir
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권5호
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    • pp.1737-1744
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    • 2012
  • Macrophage migration inhibitory factor (MIF) is a pluripotent cytokine which plays roles in inflammation, immune responses and cancer development. It assists macrophages in carrying out functions like phagocytosis, adherence and motility. Of late, MIF is implicated in almost all stages of neoplasia and expression is a feature of most types of cancer. The presence of MIF in almost all tumors and all stages of cancer makes it an interesting candidate for cancer therapy. This review explores the roles of MIF in neoplasia.