• Title/Summary/Keyword: Strength of Concrete

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The Beneficial Effects of Pectin on Obesity In vitro and In vivo (In vitro 및 In vivo에서 펙틴의 비만 억제 효과)

  • Kwon, Jin-Young;Ann, In-Sook;Park, Kun-Young;Cheigh, Hong-Sik;Song, Yeong-Ok
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.1
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    • pp.13-20
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    • 2005
  • The effects of pectin on obesity was studied using 3T3-L1 pre-adipocytes and rats fed 20% high fat diets. The concentration of leptin released from 3T3-L1 adipocytes in the presence of pectin was significantly decreased by 85% compared to that of the control (p<0.05), however, glycerol concentration was not changed. These data indicate that pectin seems to inhibit lipids accumulation in the adipocytes rather than enhance the lipolytic activity. Forty Sprague Dawley rats were fed 20% high fat diet for 8 weeks to induce obesity and then divided equally into four groups. Experimental groups were normal diet group (ND), high fat diet group (HFD), HDF with 10% pectin group (HFP10), and HDF with 20% pectin group (HFP20). Diet for the each group was prepared to be iso-caloric following AIN-76 guideline. After obesity was induced, rats were placed on an restricted diet for 9 weeks. The body weight of HFD increased 50% (p<0.05) compared to the ND, while it was decreased by 12% and 16% for HFP10 and HFP20, respectively (p<0.05). The relative amount of visceral fats for HFDl0 and HFD20 were decreased by 45% and 59% compared to that of HDF (130%), respectively (p<0.05). Pectin seems to have a greater effect on reducing visceral fats accumulation than weight reduction. Significantly increased level of triglyceride, total cholesterol or LDL-cholesterol in the plasma of HFD was returned to the normal or even below the normal by pectin diet, while the level of HDL-cholesterol increased. Lipid lowering effect was also observed in the liver and heart. These effects of pectin were dosedependent. In conclusion, the beneficial effect of pectin on the obesity was observed from cell culture experiment and animal study in terms of inhibiting the accumulation of lipids in the adipocytes.

Numerical Analyses for Evaluating Factors which Influence the Behavioral Characteristics of Side of Rock Socketed Drilled Shafts (암반에 근입된 현장타설말뚝의 주면부 거동에 영향을 미치는 변수분석을 위한 수치해석)

  • Lee, Hyuk-Jin;Kim, Hong-Taek
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.6C
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    • pp.395-406
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    • 2006
  • Drilled shafts are a common foundation solution for large concentrated loads. Such piles are generally constructed by drilling through softer soils into rock and the section of the shaft which is drilled through rock contributes most of the load bearing capacity. Drilled shafts derive their bearing capacity from both shaft and base resistance components. The length and diameter of the rock socket must be sufficient to carry the loads imposed on the pile safely without excessive settlements. The base resistance component can contribute significantly to the ultimate capacity of the pile. However, the shaft resistance is typically mobilized at considerably smaller pile movements than that of the base. In addition, the base response can be adversely affected by any debris that is left in the bottom of the socket. The reliability of base response therefore depends on the use of a construction and inspection technique which leaves the socket free of debris. This may be difficult and costly to achieve, particularly in deep sockets, which are often drilled under water or drilling slurry. As a consequence of these factors, shaft resistance generally dominates pile performance at working loads. The efforts to improve the prediction of drilled shaft performance are therefore primarily concerned with the complex mechanisms of shaft resistance development. The shaft resistance only is concerned in this study. The nature of the interface between the concrete pile shaft and the surrounding rock is critically important to the performance of the pile, and is heavily influenced by the construction practices. In this study, the influences of asperity characteristics such as the heights and angles, the strength characteristics and elastic constants of surrounding rock masses and the depth and length of rock socket, et. al. on the shaft resistance of drilled shafts are investigated from elasto-plastic analyses( FLAC). Through the parametric studies, among the parameters, the vertical stress on the top layer of socket, the height of asperity and cohesion and poison's ratio of rock masses are major influence factors on the unit peak shaft resistance.

An Investigation of Reliability and Safety Factors in RC Flexural Members Designed by Current WSD Standard Code (현행(現行) 허용응력설계법(許容應力設計法)으로 설계(設計)되는 RC 휨부재(部材)의 신뢰성(信賴性)과 안전율(安全率) 고찰(考察))

  • Shin, Hyun Mook;Cho, Hyo Nam;Chung, Hwan Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.1 no.1
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    • pp.33-42
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    • 1981
  • Current standard code for R.C. design consists of two conventional design parts, so called WSD and USD, which are based on ACI 318-63 and 318-71 code provisions. The safety factors of our WSD and USD design criteria which are taken primarily from ACI 318-63 code are considered to be not appropriate compared to out country's design and construction practices. Furthermore, even the ACI safety factors are not determined from probabilistic study but merely from experiences and practices. This study investigates the safety level of R.C. flexural members designed by the current WSD safety provisions based on Second Moment Reliability theory, and proposes a rational but efficient way of determining the nominal safety factors and the associated flexural allowable stresses of steel bars and concretes in order to provide a consistent level of target reliability. Cornell's Mean First-Order Second Moment Method formulae by a log normal transformation of resistance and load output variables are adopted as the reliability analysis method for this study. The compressive allowable stress formulae are derived by a unique approach in which the balanced steel ratios of the resulting design are chosen to be the corresponding under-reinforced sections designed by strength design method with an optimum reinforcing ratio. The target reliability index for the safety provisions are considered to be ${\beta}=4$ that is well suited for our level of construction and design practices. From a series of numerical applications to investigate the safety and reliability of R.C. flexural members designed by current WSD code, it has been found that the design based on WSD provision results in uneconomical design because of unusual and inconsistent reliability. A rational set of reliability based safety factors and allowable stress of steel bars and concrete for flexural members is proposed by providing the appropriate target reliability ${\beta}=4$.

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A Study of the Effect of Model Characteristics on Purchasing intentions and Brand Attitudes (광고모델 특성이 구매의도와 브랜드태도에 미치는 영향)

  • Kim, Sung-Duck;Youn, Myoung-Kil;Kim, Ki-Soo
    • Journal of Distribution Science
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    • v.10 no.4
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    • pp.47-53
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    • 2012
  • Businesses make use of advertising strategy using models to give consumers efficient product information. Modern advertisements often make use of models for greater reminiscence to create messages and remind viewers of the product. The purpose of this study was to examine the characteristics of each type of model. The subjects were 230 college students in their twenties or older, and the material was collected from October 20, 2011 to November 5, 2011 to examine the effects of model characteristics on buying intention as well as attitude toward a brand. A questionnaire survey was used; investigators gave one copy to each interviewee. The study investigated the characteristics of each model using a questionnaire of each 40 copies with five kinds of photographs. The characteristics of models had great influence on buying intention and attitude toward the brand: First, factor 2 (being honest and virtuous and having good credit and a good press assessment) and factor 3 (being interesting and a good communicator and creating good memories) had great influence on buying intention. Factor 2 was explained by reliability, and factor 3 by the efficiency of the model in creating a feeling. Second, factors 1 (being attractive, smart, unique, friendly, loved by others, and popular), 2, and 3 influenced attitude toward brand. Factor 1 encapsulated the outgoing characteristics of a model, factor 2 was based on reliability, and factor 3 was based on the efficiency of the model in creating a feeling. The model's positive effects on buying intention and attitudes toward brand shall be examined. For their positive influence on buying intention, reliability and efficiency shall be given attention. For their positive influence on attitude toward brand, creating a good impression, having outgoing characteristics, being reliable, and efficiency shall be given attention. The findings were as follows: Model characteristics influencing buying intention were similar to those influencing attitude toward brand. The differences were as follows. First, reliability and efficiency influenced buying intention. When customers were asked to consider the influence on buying intention of an advertisement, regardless of the strength of the buying intention, they considered these two characteristics. Customers decided to buy based not only on the credibility of the product as presented in the advertisement but also the transmission of the contents of the advertisement. Second, outgoing characteristics, reliability, and efficiency influenced attitude toward a brand. The attitude toward a brand was said to be the attitude toward the business. The attitude is produced even after buying, so businesses view it as very important. The attitude might vary depending upon the model used rather than the brand. Therefore, a model with outgoing characteristics was thought to be important. Therefore, attitude toward a brand whose model influenced buying intention as well as attitude toward brand had outgoing characteristics. The result is that an image the model was related to attitude toward the brand. As such, customers would buy the goods advertised. However, an outgoing image of a model was also important to create a positive attitude toward a business brand. For instance, talent Park Gyeong-Rim's photo was used to promote cosmetics about 10 years ago. When she worked as a model of cosmetics products, she had to make compensation for losses and damages because she made a mistake on a talk show program. At that time, customers who had bought the cosmetics product asked for refunds of several billion won. As such, models who are said to be the face of the businesses they represent can play an important role. To advertise in the most attractive and effective way, the current image of a model should be investigated by examining current activities and news articles after selecting the model, and the model's efficiency and attitude toward the brand should be examined. Factors that stimulate customers' buying decisions can be used to plan advertisement that have positive influence on a brand. This study had the limitation of investigating mainly college students and there were insufficient copies of the questionnaire. The investigation was not done widely but in detail so that a concrete investigation could not be done. Further studies shall supplement these shortcomings and discuss new directions.

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