• Title/Summary/Keyword: addition tests

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Evaluating the settlement of lightweight coarse aggregate in self-compacting lightweight concrete

  • Mazloom, Moosa;Mahboubi, Farzan
    • Computers and Concrete
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    • v.19 no.2
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    • pp.203-210
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    • 2017
  • The purpose of this paper is to evaluate the settlement of lightweight coarse aggregate of self-compacting lightweight concrete (SCLC) after placement of concrete on its final position. To investigate this issue, sixteen samples of concrete mixes were made. The water to cementitious materials ratios of the mixes were 0.35 and 0.4. In addition to the workability tests of self-compacting concrete (SCC) such as slump flow, V-funnel and L-box tests, a laboratory experiment was made to examine the segregation of lightweight coarse aggregate in concrete. Because of the difficulties of this test, the image processing technique of MATLAB software was used to check the segregation above too. Moreover, the fuzzy logic technique of MATLAB software was utilized to improve the clarity of the borders between the coarse aggregate and the paste of the mixtures. At the end, the results of segregation tests and software analyses are given and the accuracy of the software analyses is evaluated. It is worth noting that the minimum and maximum differences between the results of laboratory tests and software analyses were 1.2% and 9.19% respectively. It means, the results of image processing technique looks exact enough for estimating the segregation of lightweight coarse aggregate in SCLC.

Diagnostic Value on the Orthopaedic Tests for Sacroiliac Joint Dysfunction (천장관절 기능부전에 대한 검사방법들의 진단적 가치 : 정형도수치료적 평가를 중심으로)

  • Yoon, Hong-Il;Sim, Hyun-Po
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.16 no.1
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    • pp.64-76
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    • 2010
  • The sacroiliac joint is difficult to appropriately examine and treat because it is extremely complex and also is difficult to distinguish dysfunctions from those of the spine and hip which are highly intergrated functionally. In addition generally traditional x-rays and CT scans also are not beneficial in detecting sacroiliac joint dysfunction. The manipulative physiotherapist should seek to establish a series of relevant finding that build into a case implicating the sacroiliac joint. When deciding to use these diagnostic tests, the examiner must determine if the test will give reliable and useful information that will help in the diagnosis and subsequent treatment. To be useful diagnostic tests must give reliable data and be valid and the most useful methods of determining whether a test is a good test for pathology under consideration are sensitivity and specificity. In the ideal world, one would want a test that has both high sensitivity and high specificity. The purpose of this review is to ascertain diagnostic value on the tests for sacroiliac joint dysfunction by literature.

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A Study on the Development of Business English Tests Based on an Analysis of the Predictive Validity of the TOEIC and a Delphi Study of Working Skills in English to be Assessed (비즈니스 영어 업무 능력에 대한 TOEIC의 예측 타당도 검증과 델파이 연구)

  • 김은상;최연희
    • Korean Journal of English Language and Linguistics
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    • v.4 no.2
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    • pp.229-252
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    • 2004
  • The TOEIC has widely used to evaluate business English proficiency in Korea, but those who achieved high scores still often face difficulties in performing their duties in English at work. This implies that the test may not evaluate business English proficiency effectively enough. With an ultimate goal of proposing an effective way of assessing business English proficiency, therefore, his study analyzed the predictive validity of the TOEIC. A correlation analysis was conducted between TOEIC scores of 64 office workers of multinational companies and their working skills in English evaluated by themselves, and their colleagues and seniors. Its results illustrated a significant correlation between their listening and reading scores and their working skills measured by all the groups, but not between their scores and their working skills in speaking and writing. In addition, the study did a delphi study to identify working skills in English to be assessed in business English tests and a contents analysis of the TOEIC. The results suggest business English tests should be able to assess working skills by work types and more direct testing of working skills in speaking and writing is needed.

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Investigation of Cutting Characteristics in the Sharp Comer for the Case of Cutting of Inconel 718 Super-alloy Sheet Using High-power CW Nd:YAG Laser (고출력 CW Nd:YAG 레이저를 이용한 인코넬 718 판재 절단시 모서리부 절단 특성 분석)

  • Ahn, Dong-Gyu;Byun, Kyung-Won
    • Journal of Welding and Joining
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    • v.26 no.5
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    • pp.90-96
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    • 2008
  • The objective of this paper is to investigate the effects of the laser power, the material thickness, comer angles, and the loop size on the formation of the comer in the cutting of Inconel 718 super-alloy sheet using high-power CW Nd: YAG laser. In order to investigate the influence of comer angles and loop sizes on the melted area and the formation of comer in the sharp comer, angular cutting tests and loop cutting tests were carried out. The results of the angular cutting tests were shown that the melted area is minimized and the melting mode is changed from nose melting in the thickness direction to the secondary melting induced by the attached dross when the comer angle is $90^{\circ}$. Through the results of loop cutting tests, the variation of the melted area and the comer shape in the sharp comer according to the loop size were examined. In addition, it was shown that a proper loop size is approximately 3 mm. The results of above experiments will be reflected on the knowledge base to generate optimal cutting path of the laser.

Dynamic characteristics of combined isolation systems using rubber and wire isolators

  • Lee, Seung-Jae;Truong, Gia Toai;Lee, Ji-Eon;Park, Sang-Hyun;Choi, Kyoung-Kyu
    • Nuclear Engineering and Technology
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    • v.54 no.3
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    • pp.1071-1084
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    • 2022
  • The present study aims to investigate the dynamic properties of a novel isolation system composed of separate rubber and wire isolators. The testing program comprised pure compressive, pure-shear, compressive-stress dependence, and shear-strain dependence tests that used full-scale test specimens according to ISO 22762-1. A total of 22 test specimens were fabricated and investigated. Among the tests, the pure compressive test was a destructive test that reached up to the failure stage, whereas the others were nondestructive tests before the failure stage. Similar to the pure-shear test, at each compressive-stress level in the compressive dependence test or at each shear-strain level in the shear-strain dependence test, the cyclic loading was conducted for three cycles. In the nondestructive tests, examination of the dynamic shear properties in the X-direction was independent of the Y-direction. The test results revealed that the increase in the shear strain increased the energy dissipation but decreased the damping ratio, whereas the increase in the compressive stress increased the damping ratio. In addition, a macro model was developed to simulate the load-displacement response of the isolation systems, and the prediction results were consistent with the experimental results.

Determination of K values from tunnel model tests in sandy ground (터널모형실험을 통한 사질토 지반에서의 K값의 산정)

  • Lee, Yong-Joo;Ryu, Chang-Youl
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.12 no.1
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    • pp.87-94
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    • 2010
  • This study mainly focused on the subsurface settlement due to shallow and deep tunneling in sandy ground. In order to figure out theoretical deformation patterns in association with the ground loss during the progress of tunneling, laboratory model tests using aluminum rods and finite element analyses using the CRISP program were carried out. As a result of comparison between the model test and the finite element analysis, the similar deformation patterns were found. In addition, it was identified that the most K values obtained from both the FEA and the model tests were distributed between Dyer et al. (1996) and Moh et al. (1996) of the field observation data. Based on the model test data, the linear equation of K for the sandy soil could be obtained.

Optimization and Quality Characteristics of Balsamic Vinegar Jelly with Various Gelling Agents (겔화제를 달리한 발사믹 식초 젤리의 품질 특성)

  • Choi, Eun-Hee;Kim, Dong-Seok;Choi, Soo-Keun;Park, Ki-Bong
    • Culinary science and hospitality research
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    • v.19 no.1
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    • pp.151-163
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    • 2013
  • The purpose of this study was to examine the optimization and quality characteristics of balsamic vinegar jelly by the addition of various gelling agents: agar, gelatin, arrowroot starch, potato starch. For this purpose, mechanical tests(moisture content, color value, pH, sugar content, texture) and sensory tests(quantitative descriptive analysis & acceptance test) were conducted, showing the following results. The moisture content of balsamic jelly was the highest in the gelatin addition group, the color intensity of the L value in the potato starch addition group, redness a value in the gelatin addition group, and the b value(yellowness) in the agar addition group. The pH of balsamic jelly was the highest values in the gelatin addition group while its sugar content was the highest values in the arrowroot starch addition group. As a result of measuring balsamic jelly texture, there were significant differences in hardness, chewiness and gumminess by gelling agents. In the quantitative descriptive analysis of sensory test, the gelatin addition group showed the most high level in purple color intensity, glossiness, transparency, and chewiness. As for the acceptance in the sensory test, the gelatin addition group showed the most high level in appearance, taste, texture, and overall acceptance, which also had a significant difference. In case of balsamic flavor, Arr added arrowroot starch showed the highest values, which also had a significant difference. The result of this study showed that the gelatin addition group made a positive acceptance and improvement of sensory and machinery quality characteristics.

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Effects of Alloying Elements on the Surface Characteristics of Fe-38Al Intermetallic Compounds (Fe-38 at.% Al계 금속간화합물의 표면특성에 미치는 합금원소의 영향)

  • 최한철
    • Journal of the Korean institute of surface engineering
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    • v.37 no.2
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    • pp.128-136
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    • 2004
  • Effects of alloying elements on the surface characteristics of Fe-38Al intermetallic compounds were investigated using potentiostat. The specimens were casted by the vacuum arc melting. The subsequent homogenization and the stabilization led to the homogeneous DO$_3$ structure of the specimen. After the corrosion tests, the surface of the tested specimen was observed by the optical microscopy and scanning electron microscopy(SEM). For Fe-38 at.% Al intermetallic compound, the addition of Cr and Mo proved to be beneficial in decreasing the grain boundary attack by decreasing the active current density. Addition of Band Nb resulted in a higher active current density and also a higher passive current density. These results indicated the role of Cr and Mo in improving the pitting corrosion resistance of Fe-38 at.%Al intermetallic compound. Band Nb addition to Fe-38 at.%Al accelerated the granular corrosion. Fe-38 at.%Al containing Cr and Mo showed remarkably improved pitting corrosion resistance in comparison with Band Nb addition to Fe-38 at. %Al.

Enhancing the Antioxidant Activities of Wines by Addition of White Rose Extract

  • Seong, Hyunbin;Heo, Jieun;Lee, Kyun Hee;Lee, Yoon Bok;Kim, Yun Bae;Han, Nam Soo
    • Journal of Microbiology and Biotechnology
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    • v.27 no.9
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    • pp.1602-1608
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    • 2017
  • White rose petal extract (WRE) contains large amounts of phenolic compounds and is considered edible. In this study, red and white wines were prepared by the addition of WRE (0.10% or 0.25% (w/v)), followed by fermentation at $25^{\circ}C$ for 15 days. The fermentation profiles, colors, sensory test results, and antioxidant activities of the wines were compared. As reported herein, the fermentation profiles of the pH, $CO_2$ production rate, and final ethanol concentration were not affected by the addition of WRE, but a slow consumption rate of sugar was observed in 0.25% WRE-added wine. In contrast, the total polyphenol concentrations in WRE-added wines increased significantly (p < 0.05) in a dose-dependent manner, resulting in appreciable enhancement of the antioxidant activities of the wines. Chromaticity tests showed slight changes in the redness and yellowness, but sensory tests showed that the overall flavor qualities of the WRE-added wines were acceptable to the panels. This study demonstrates that addition of WRE to wine confers beneficial health effects and this treatment results in better outcome in white wine.

Comparison Analysis of Fiber Distribution and Workability for Amorphous Steel Fiber Reinforced Concrete (비정질강섬유 보강콘크리트 작업성 및 섬유 분산성 비교분석)

  • Kim, Byoung-Il;Lee, Sea-Hyun
    • Resources Recycling
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    • v.23 no.4
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    • pp.47-57
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    • 2014
  • The research was conducted to analyze workability and fiber distributions of amorphous steel fiber reinforced concrete by changing fiber length and fiber addition ratio. The inverted slump cone and vebe tests as well as slump test was performed to understand the fluidity of amorphous steel fibers which have quite different appearance compared to conventional steel fibers. Test results showed that thin plate type of amorphous steel fibers required different test approach to figure out workability since the reduction of workability from slump test was different that from inverted slump cone and vebe tests. In conclusion, fluidity of amorphous steel fibers to concrete was significantly degraded as fiber length and addition ratio increase. Also, fibers space in cement matrix was apparently reduced as the increase of fiber length and addition ratios without fiber balling.