• 제목/요약/키워드: addition tests

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LIMITATIONS OF SPHERE ANEMOMETRY FOR LOW GAS VELOCITY MEASUREMENTS

  • Han, J.Y.;O.F. Turan
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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    • pp.297-304
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    • 1997
  • Sphere anemometry technique is re-visited for low gas velocity measurements during full-scale fire tests. This technique has the advantage of requiring only one channel per sphere for data acquisition, in addition to being cheap and rugged, The results indicate that the technique is useful for small fuel load burns with low radiation levels. For large fuel loads, the usefulness is up to sprinkler activation temperatures.

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청국장 분말을 첨가한 어묵의 품질 특성 (Study on Quality Characteristics of Fish Paste Containing Cheonggukjang Powder)

  • 박복희;조희숙;박승희
    • 한국식생활문화학회지
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    • 제30권2호
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    • pp.213-219
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    • 2015
  • This study was conducted to promote the utilization of fish paste containing four different amounts (0%: control, 2, 4, and 6%) of cheonggukjang powder. For Hunter color values, L values of samples decreased as concentration of cheonggukjang powder increased, and a and b values increased. Folding tests for all samples showed good flexibility. In the texture meter test, hardness, cohesiveness, and springiness increased according to increasing concentrations of cheonggukjang powder. However, gumminess and brittleness of fish paste were reduced upon addition of cheonggukjang powder. In the sensory evaluation, fish paste prepared with 2% cheonggukjang powder was more preferred over other fish pastes. This study suggests that addition of 2% cheonggukjang powder to fish paste could be a good way to increase cheonggukjang powder without decreasing texture acceptability.

Enhancing mechanical and durability properties of geopolymer concrete with mineral admixture

  • Jindal, Bharat Bhushan;Singhal, Dhirendra;Sharma, Sanjay;Parveen, Parveen
    • Computers and Concrete
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    • 제21권3호
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    • pp.345-353
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    • 2018
  • This paper approaches to improve the mechanical and durability properties of low calcium fly ash geopolymer concrete with the addition of Alccofine as a mineral admixture. The mechanical and durability performance of GPC was assessed by means of compressive strength, flexural strength, permeability, water absorption and permeable voids tests. The correlation between compressive strength and flexural strength, depth of water penetration and percentage permeable voids are also reported. Test results show that addition of Alccofine significantly improves the mechanical as well as permeation properties of low calcium fly ash geopolymer concrete. Very good correlations were noted between the depth of water penetration and compressive strength, percentage permeable voids and compressive strength as well as between compressive strength and flexural strength.

단시간의 전신근력활동이 정신적 작업에 미치는 영향 (The Influences of Whole-body Activity in A Short Time Period on Mental Work)

  • 김정만
    • 한국산업경영시스템학회:학술대회논문집
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    • 한국산업경영시스템학회 2002년도 춘계학술대회
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    • pp.69-78
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    • 2002
  • This paper examines the effects on mental fatigue of changes in the intensity of physical activity. A treadmill-equipped instrument and perception tester were used to attain several levels of physical activity In this paper, In order to determine the individual levels of physical activity of subjects, Borg-RPE scale, Heart Rate(HR) and Respiratory Quotient(RQ) were used. Also, an addition test in whole-body activity on treadmill-equipped instrument as an indicator of mental fatigue were performed. In the above experiments, the scores obtained in addition test administered before and after physical activity at each intensity level used. Restricted within the limits of this paper, the results of these tests showed that mental fatigue decreased after physical activity.

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칼슘 첨가량에 따른 발포 알루미늄의 기계적 성질 (Mechanical Properties of the Foamed Aluminum According to the Quantity of Calcium)

  • 도복환;김주현
    • 한국공작기계학회논문집
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    • 제15권1호
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    • pp.113-118
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    • 2006
  • In this work, we observed the changes in mass difference according to Al-foam's amount of Ca contents which depends on the viscosity control of fusion, quality of foamed addition, mixing, temperature tests. These are crucial influencing factors in determining foam-metal's size in the manufacturing process. In order to obtain the specimen, we changed the specific gravity from 0.2 to 0.3 for the study of the light weight, and obtained the optimal values of specific gravity, and then showed the mechanical characteristics of ultra-lightweight metal according to the changing mass. The optimal conditions for aluminum foam is when the addition of Ca content in $1.5wt\%~2.0wt\%$

콘크리트용 유기혼화제의 과잉첨가 효과 (Effect of Excessive Addition of Organic Admixtures on the Properties of Concrete)

  • 최재진;박원태;김기형;최연왕
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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    • pp.631-637
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    • 1999
  • Effect of excessive addition of water reducing agent was examined by concrete tests. Water reducing agents of lignin or naphtalene base were used in the experiment. Setting of concrete was retarded according to the increase of dosage of water reducing agent and was extremely delayed at the 3 times or more use of lignin base agent and near 5 times or more use of naphtalene base agent respectively. When water reducing agent was used more than 6 times of standard dosage, early strength of concrete was very low and the strength reduction was very severe at all test ages in the concrete using lignin base agent.

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팽창재를 혼입한 시멘트 경화체의 팽창모델 (Expansion Model of Cement Paste using Expansive Additive)

  • 박선규;야구귀문;김무한
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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    • pp.789-792
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    • 2005
  • Development of high-strength concrete and improved durability has brought new opportunities to the construction industry. However, some attention was given to characteristics of such concrete, in particular with respect to their cracking sensitivity. It has been argued and demonstrated experimentally that a low water/cement ratio concrete undergoes shrinkage due to self-desiccation. This so-called autogenous shrinkage cracking is a major concern for concrete durability. One possible method to reduce cracking due to autogenous shrinkage is the addition of expansive additive. Tests conducted by many researches have shown the beneficial effects of addition of expansive for reducing the risk of shrinkage-introduced cracking. This paper aimed at forecasting deformation of high strength cement paste with expansive additive for early age.

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Polychotomous Machines;

  • Koo, Ja-Yong;Park, Heon Jin;Choi, Daewoo
    • Communications for Statistical Applications and Methods
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    • 제10권1호
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    • pp.225-232
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    • 2003
  • The support vector machine (SVM) is becoming increasingly popular in classification. The import vector machine (IVM) has been introduced for its advantages over SMV. This paper tries to improve the IVM. The proposed method, which is referred to as the polychotomous machine (PM), uses the Newton-Raphson method to find estimates of coefficients, and the Rao and Wald tests, respectively, for addition and deletion of import points. Because the PM basically follows the same addition step and adopts the deletion step, it uses, typically, less import vectors than the IVM without loosing accuracy. Simulated and real data sets are used to illustrate the performance of the proposed method.

석출상이 분산제어된 내마모성 니켈기 윤활합금 연구 (A Study on Ni Base Anti-galling alloy with Finely Dispersed Precipitates)

  • 김용규;김경탁
    • 한국주조공학회지
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    • 제26권4호
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    • pp.191-196
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    • 2006
  • The effects of Bi and Te on the anti-galling behaviors of Ni base alloy were investigated by SEM, galling test and wear test. Anti-galling characteristics depended on the structure of matrix and distribution of Bi-rich phase which was precipitated at grain boundary. The addition of 5 wt% Bi markably enhanced anti-galling properties. The addition of Te caused Bi-rich precipitates to disperse finely and casting structure to form equiaxed type. From the above tests, the concentration of 5 wt% Bi and 1 wt% Te was selected to optimize in this alloy.

에트링가이트-석회 복합계 팽창재의 수화반응 모델화 (Hydration Model of Ettringite-Gypsum Type Expansive Additive)

  • 박선규;야구귀문;송하원;김무한
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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    • pp.683-686
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    • 2004
  • In recent years, some attention was particularly given to cracking sensitivity of high performance concrete. It has been argued and demonstrated experimentally that such concrete undergoes autogenous shrinkage due to self-desiccation at early age, and, as a result, internal tensile stress may develop, leading to micro cracking and macro cracking. One possible method to reduce cracking due to autogenous shrinkage is the addition of expansive additive. Tests conducted by many researches have shown the beneficial effects of addition of expansive additive for reducing the risk of shrinkage-introduced cracking. However, the research on hydration model of expansion additive has been hardly researched up to now. This paper presents a study of the hydration model of Ettringite-Gypsum type expansive additive. Result of comparing forecast values with experiment value, proposed model is shown to expressible of hydration of expansive additive.

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