• Title/Summary/Keyword: investigation reports

Search Result 554, Processing Time 0.032 seconds

A Study and Investigation on the Influence of Static and Dynamic Loading on the Properties of Handmade Persian Carpet (I) - The Effect of Static Loading -

  • Mirjalili S. A.;Sharzehee M.
    • Fibers and Polymers
    • /
    • v.6 no.2
    • /
    • pp.139-145
    • /
    • 2005
  • The paper reports the physical and mechanical properties of hand-woven carpets, which have been put under static force. Two groups of wool fibres, from two parts of Iran, were prepared to spin pile yams for the carpets. Each group of the fibres included both conventional and tanned wool. Then two yam counts, $N_m$ = 4/2 and 6/2, were spun for two different knot densities. After weaving the carpets, they were put under static force and their thickness variations were measured and plotted against time, in logarithm scale. The resiliency of the carpets piles after eliminating the static force, were measured and plotted against time, in logarithm scale, too. The results were compared to each other and analysed with respect to parameters such as the type and quality of the wool fibres as well as knot density of the carpets.

A Study on the New Criteria for Assessing the Insulation Deterioration of Generator Stator Winding (발전기 고정자 권선의 새로운 절연열화 판정기준 설정에 관한 연구)

  • Hwang, D.H.;Kim, Y.J.;Kim, J.B.;Jeon, J.W.;Kim, H.G.;Park, J.J.
    • Proceedings of the KIEE Conference
    • /
    • 1997.07e
    • /
    • pp.1692-1695
    • /
    • 1997
  • This paper describes the relationship between the various non-destructive parameters and the breakdown voltage for the 17 kV, 300 MVA and the 22 kV, 500 MVA generators stator bars with polyester and epoxy/mica insulation respectively. Also, this study reports the results of an investigation into the factors which can assess the insulation condition of generator stator winding. Furthermore, a new parameter, Partial Discharge Index(PDI), is introduced as the valuable parameter for the assessment of insulation condition. The ratio between partial discharge increment and the stepwise voltage increment from the Discharge Inception Voltage (DIV) at the characteristic or resonant frequency band shows the close relationship between the breakdown voltage and PDI.

  • PDF

Design Optimization of Centrifugal Pump Impellers in a Fixed Meridional Geometry using DOE

  • Kim, Sung;Choi, Young-Seok;Lee, Kyoung-Yong;Yoon, Joon-Yong
    • International Journal of Fluid Machinery and Systems
    • /
    • v.2 no.2
    • /
    • pp.172-178
    • /
    • 2009
  • This paper reports on an investigation (using RSM with commercial CFD software) of the performance characteristics of the impeller in a centrifugal pump. Geometric parameters of vane plane development were defined with the meridional shape and frontal view of the impeller. The parameters are focused on the blade-angle distributions through the impeller in a fixed meridional geometry. For screening, a $2^k$ factorial design has been used to identify the important design parameters. The objective functions are defined as the total head rise and the total efficiency at the design flow-rate. From the $2^k$ factorial design results, it is found that the incidence angles and the exit blade angle are the most important parameters influencing the performance of the pump.

Investigation on the Self-Pressurization in Cryogenic Liquid Storage System (극저온 유체 저장 시스템의 압력 증가에 대한 연구)

  • Seo, Man-Su;Kim, Young-Kwon;In, Se-Hwan;Jeong, Sang-Kwon
    • Proceedings of the SAREK Conference
    • /
    • 2008.06a
    • /
    • pp.142-147
    • /
    • 2008
  • This paper reports an analysis of self-pressurization in a closed cryogenic liquid storage system and its comparison with experimental data using liquid nitrogen. Partial equilibrium model(PEM), revised thermodynamic analysis of homogeneous model, has been applied for the pressurization in a closed tank. The vapor and liquid bulk temperature and the liquid-vapor interface temperature are separately calculated as their own representative values in this analysis. The analysis results of the partial equilibrium model are compared with the experimental data and other preceding homogeneous temperature models for validation.

  • PDF

An Improvement for Impact Factor Determination to Traffic Loads (통행차량에 의한 충격계수 산정방법 개선)

  • Koo, Bong-Kuen;Ryu, Taek-Eun;Lee, Jae-Bum;Ryu, Youn-Jong
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.6 no.2
    • /
    • pp.217-224
    • /
    • 2002
  • This paper is proposed a reasonable method for determining the dynamic properties, the impact factors caused by traffic loads on highway bridges. In addition, the impact factors obtained in previous inspection reports were classified by the span length of the bridge, kind of bridge and type of bridge and the result of the impact factor was adjusted by a statistical method and presented problems. Also, the method for determining the impact factor using traffic load is proposed and the proposed method is compared with the specification code. The method estimating the impact factors due to the traffic loads can efficiently recognize the response of the structure by providing the impact factors and help to save the investigation cost, and also it can be used for the maintenance of structures using the usual test of bridges.

Review of cases of patient risk associated with ginseng abuse and misuse

  • Paik, Doo Jin;Lee, Chang Ho
    • Journal of Ginseng Research
    • /
    • v.39 no.2
    • /
    • pp.89-93
    • /
    • 2015
  • Ginseng has long been used as a functional food or therapeutic supplement and it is empirically known to be safe and nontoxic. During recent decades, a number of in vitro and in vivo experiments, as well as human studies have been conducted to prove the safety of various types of ginseng samples and their components. Clinical trials, case reports, and in vitro and in vivo research articles addressing the safety, toxicity, and other adverse events of ginseng application were selected and reviewed. Patient risks associated with ginseng abuse and misuse such as affective disorder, allergy, cardiovascular and renal toxicity, genital organ bleeding, gynecomastia, hepatotoxicity, hypertension, reproductive toxicity, and anticoagulant-ginseng interaction were reviewed and summarized. There are some cases of patient risk associated with ginseng abuse and misuse depending on patients' conditions although further investigation in more cases is required to clarify these issues.

Analysis of the Empirical Effects of Contextual Matching Advertising for Online News

  • Oh, Hyo-Jung;Lee, Chang-Ki;Lee, Chung-Hee
    • ETRI Journal
    • /
    • v.34 no.2
    • /
    • pp.292-295
    • /
    • 2012
  • Beyond the simple keyword matching methods in contextual advertising, we propose a rich contextual matching (CM) model adopting a classification method for topic targeting and a query expansion method for semantic ad matching. This letter reports on an investigation into the empirical effects of the CM model by comparing the click-through rates (CTRs) of two practical online news advertising systems. Based on the evaluation results from over 100 million impressions, we prove that the average CTR of our proposed model outperforms that of a traditional model.

The history and regulatory mechanism of the Hippo pathway

  • Kim, Wantae;Jho, Eek-hoon
    • BMB Reports
    • /
    • v.51 no.3
    • /
    • pp.106-118
    • /
    • 2018
  • How the organ size is adjusted to the proper size during development and how organs know that they reach the original size during regeneration remain long-standing questions. Based on studies using multiple model organisms and approaches for over 20 years, a consensus has been established that the Hippo pathway plays crucial roles in controlling organ size and maintaining tissue homeostasis. Given the significance of these processes, the dysregulation of the Hippo pathway has also implicated various diseases, such as tissue degeneration and cancer. By regulating the downstream transcriptional coactivators YAP and TAZ, the Hippo pathway coordinates cell proliferation and apoptosis in response to a variety of signals including cell contact inhibition, polarity, mechanical sensation and soluble factors. Since the core components and their functions of the Hippo pathway are evolutionarily conserved, this pathway serves as a global regulator of organ size control. Therefore, further investigation of the regulatory mechanisms will provide physiological insights to better understand tissue homeostasis. In this review, the historical developments and current understandings of the regulatory mechanism of Hippo signaling pathway are discussed.

Development of submersion sensors using multi-mode fibers spliced with a fiber Bragg grating (다중모드 광섬유 융착형 침수 감지 센서 개발)

  • Sohn, Kyung-Rak;Key, Kwang-Hyun;Shim, Joon-Hwan;Cho, Seok-Je
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.33 no.6
    • /
    • pp.925-931
    • /
    • 2009
  • This paper reports a preliminary experimental investigation and characterization of an optical fiber-based submersion sensor system for applications in water flooding and leakage. The sensor system comprises a multi-mode fiber spliced with fiber Bragg grating and an intensity-based interrogator. Submersion tests were conducted in water-air and Glycerin-air environments. By the refractive index of the fiber-probe surrounding materials, the reflectance and the detecting power level is determined. When the probe is dipped into the water, the optical output power dramatically decreases from -7.5dBm to -17.5dBm. But, the center of Bragg wavelength is not affected in spite of external material changes. Temporal response characteristics of the sensor system is investigated to verify the real-time reaction. When the probe is immersed into the liquid, there is no transition time.

Study on the Stability Criteria for Small Fishing Vessels and Cargo Ships (소형 어선 및 화물선의 복원성기준 연구)

  • Gwon, Su-Yeon;Lee, Hui-Jun
    • Journal of Korea Ship Safrty Technology Authority
    • /
    • s.22
    • /
    • pp.19-33
    • /
    • 2007
  • According to amendments of ship safety act which comes into force from 4 Nov. 2007, the amended stability criteria should be applied to the small vessels of 12m or more in length. In this paper, the dimensions of domestic small vessels and the casualty reports of capsizing accidents are analyzed. And 58 ships are sampled, modeled for the investigation of the stability performance. Based on the regression analysis of the model ship's allowable metacentric-heights under several stability requirements, stability criteria for small fishing vessels and cargo ships are proposed.

  • PDF