• Korean Journal of Agricultural Science
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• v.3 no.2
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• pp.214-224
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• 1976

This research was attempted as one of studies on the strength of mortar added admixtures at different curing temperatures. Variations of curing temperature to. test compressive strength, tensil strength and bending strength were $20^{\circ}C$, $30^{\circ}C$ and $35^{\circ}C$ and these results were summarized as follow : In strength of mortar added briquette ash, the compressive strength was increased: 1.58 percent, the tensile strength 0.96 percent, and the bending strength 1.26 percent compared with standard strength, by increasing one degree of celsius temperature. Also in strength of mortar added fly ash, the compressive strength increased on the average 1.3 percent, the tensile strength 0.99 percent, and the bending strength 1.18 percent at the above conditions. In case of using fly ash as admixture, maximum compressive strengths was attained at the level of 25 percent of fly ash, maximum tensile strength at the level of 20 percent of fly ash, and maximum bending strength at the level of 20 percent of fly ash. In case of using briquette ash, maximum compressive strength was attained maximum strength at 20 percent of the admixture, maximum tensile strength at the level of 15 to 20 percent of admixture and maximum bending strength at the level of 20 percent of admixture. Although addition of briquette ash was less effective in increasing the strength compared with the addition of fly ash, briquette ash might be used as one of admixtures because the control of curing temperature might affect in getting the required practical strength.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.6 no.1
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• pp.73-87
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• 1996

The mechanical properties of 2D ceramic composites fabricated bythe newly developed powder infiltration and subsequent multiple impregnation process were characterised by both 3-point flexure and tensile tests. These tests were performed with strain gauge and acoustic emission instrument. The woven fabric composites used for the test have the basic combinations of $Al_{2}$$O_{3}$ fabric/$Al_{2}$$O_{3}$ and SiC fabric (Tyranno)/SiC. Uniaxially aligned SiC fibre(Textron SCS-6)/SiC composites were also tested for comparison, The ultimate flexural strength and first-matrix cracking stress of SiC fabric/SiC composite with 73% of theoretical density were about 300 MPa and 77 MPa respectively. However, the ultimate tensile strengths of composite were generally one third of flexural strengths, and first-matrix cracking stress in a tension test was also much lower than the value obtained from flexure test. The lower mechanical properties measured by tension test were analysed quantitatively bythe differences in stressed volume using Weibull statistics. This showed that the ultimate strength and the firs-tmatrix cracking stress of woven laminate composites were mainly determined bythe gauge length of fibres and the stressed volume of matrix respectively. Incorporation of SiC whiskers into the matrix increased first-matrix cracking stress by increasing the matrix failure strain of composites.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.3 no.1
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• pp.45-58
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• 1993

Owing to consecutive start of operation of large-scale coal-fired power plants in Korea, the ash production amounts to about 2 million tons per year. The impact of rising disposal costs, looming environmental problems and increased ash tonnages has heightened the concerns about coal ash utilization. The paper mainly describes the correlation between bending strength and microstructure of brick body from fly ash and clay mixture. The results show that bending strength depends mainly on the size and quantity of pore, the sinterability of matrix, and the crack due to the coarse quarts grain, and that the brick body added 15 wt.% fly ash has the best bending strength over the whole firing range.

• Proceedings of the Materials Research Society of Korea Conference
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• 1993.11a
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• pp.48-48
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• 1993

• Journal of the Korean Wood Science and Technology
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• v.15 no.1
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• pp.12-21
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• 1987

본질(本質) Cement board제조(製造)를 위하여 지금까지 톱밥, 목편(木片) 및 목수(木手)(excelsior)가 사용되어 왔으나, Wafer를 사용한 제품(製品)은 아직 개발(開發)되지 않고 있는 실정이다. 따라서, 본(本) 연구(硏究)는 Cement wafer board를 압력별(壓力別), Wafer 길이별(別), Cement와 목재(木材)의 배합비별(配合比別), Wafer 배열별(排列別)로 제조(製造)하여 그 영향인자(影響因子)를 조사(調査)하고 이에 따른 제품(製品)의 물리적(物理的), 기계적(機械的) 성질(性質)을 구명(究明)하고자 실시(實施)하였으며 다음과 같은 결론(結論)을 얻었다. 1. Cement Wafer board 제품(製品)의 적정압력(壓力)은 30kg/$cm^2$이었고, 30kg/$cm^2$ 이상(以上)의 압에서는 board의 기계적 성질에 나쁜 영향을 미쳤다. 2. Cement와 목재(木材)의 배합비(配合比)가 2.1을 넘을 경우에는 board의 성질에 나쁜 영향을 끼쳤다. 3. 한쪽 방향(方向)으로 Cement-Wafer가 배열된 조건에서 제조된 CWB가 최고의 곡강도(曲强度)를 나타내었다. 4. CWB의 곡강도(曲强度)는 다른 목질(木質) Cement board보다 높은 값을 나타내었으나 박리강도(剝離强度)에 있어서는 목편 Cement board보다 약간 낮은 값을 나타내었다. 5. CWB의 난연성(難燃性) 시험(試驗)은 난연3급(難燃3級)을 만족시켰다.

• Journal of the Microelectronics and Packaging Society
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• v.9 no.3
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• pp.25-29
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• 2002

Single ion exchange process was used, and the ion exchange behavior and mechanical properties were investigated in substrate glass for flat panel display. In order to study the effects of ion exchange, ion exchange behavior with ion penetration depth, amount of ion exchange, density and thermal expansion was measured according to the time and temperature. The mechanical properties were evaluated by the three point bending test and curvature change, and then the fracture patterns were investigated by optical microscope.

• Korean Journal of Materials Research
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• v.10 no.1
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• pp.83-89
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• 2000

$Si_3N_4$ powder with 2wt% $Al_2O_3$ and 6wt% $Y_2O_3$ additives was sintered by gas pressure sintering (GPS) technique. The variations in the unlubricated wear behavior depending on sintering time were compared. Tribological properties depending on sintering time are associated with fracture toughness as well as flexural strength of materials. When increasing the sintering time, the larger elongated grains were formed as a result of exaggerated grain growth. As the fracture toughness and flexural strength decreased, the wear volume increased. On the basis of these experimental results, the unlubricated wear properties of silicon nitride were found to be governed mostly by both the fracture toughness and the flexural strength of the material.

• 한국HCI학회:학술대회논문집
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• 2007.02b
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• pp.439-444
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• 2007

정서 전달에는 언어적 의사소통뿐만 아니라 비언어적 의사소통이 거론되곤 한다. 하지만 지금까지의 비언어적 의사소통 연구는 대부분 언어의 음향학적 연구나 얼굴표정 연구에 국한되었다. 또한 음악의 정서에 대한 연구는 음악적 구조 혹은 스타일과 여러 성격적 특질 및 행동 간의 관계, 혹은 생리적 효과 등 어떤 음악(what music)이 특정한 효과를 일으키느냐에 중점을 두고 있었다. 따라서 본 연구에서는 Gabrielsson & Juslin(1996)의 연구에 의거, 음악을 통하여 작곡가가 아닌 연주자의 의도된 정서가 청자에게 얼마나 잘 지각될 수 있는지 알아보고자 하였다. 봉 녕구의 가설은 다음과 같다; 첫째, 연주자의 정서적 의도는 음악의 모든 물리적 변인에 영향을 준다; 둘째, 청자는 의도된 정서를 지각하는 데 일반적으로 성공적이다; 셋째, 특정 정서는 다른 정서보다 더 잘 구분된다. 본 연구에 사용된 곡은 학습 효과를 배제하기 위하여 새롭게 전문 작곡가에 의해 작곡되었으며, 전문 연주자는 동일한 곡을 7종류의 정서(행복한, 슬픈, 화난, 두려운, 다정한, 엄숙한, 정서 표현 없음)를 표현하도록 연주하였다. 하나의 완전한 음악을 표현하기 위하여 각 곡은 멜로디(악기구성: 일렉트릭 기타, 베이스, 그랜드 피아노)와 리듬(드럼)을 포함하였다. 실험참가자는 각 곡을 듣고 7개의 정서 종류 각각에 점수를 평정하였다. 그 결과 이전 연구와 마찬가지로 청자는 연주자의 의도된 정서를 일반적으로 지각하는 데 성공하였으며 7개의 정서 중 특징적인 정서("행복한", "슬픈", "화난", "다정한") 는 다른 정서 보다 더 잘 구별되었다. 본 연구에 사용된 "두려운" 정서 곡의 음향분석 결과 소리 강도의 큰 변산이 특징이었다. 이는 이전 연구에서 "두려운" 정서의 특징인 타이밍의 큰 변산과 함께, "두려운" 정서가 '불규칙적이거나 변화가 커서 예측하기 어려운' 속성을 지니고 있음을 시사한다. 또한 "다정한" 정서에 대해서 본 연구에서는 다른 모든 정서와 유의미한 차이를 보인 반면, 이전 연구에서는 "슬픈"과 유의미한 차이가 없었다. 이는 본 연구에 쓰인 "다정한" 정서의 곡은 리듬 패턴을 다른 정서 버전과는 다르게 보사노바 리듬을 사용하였다. 이전 연구와는 다르게 빠른 템포였음에도 불구하고 구별이 잘 된 이유는 이와 같이 장르 특징적인 영향이 컸기 때문이라고 할 수 있다. 이는 연주자나 음악 스타일 자체의 성격이 정서 판단에 있어 큰 영향을 준다는 사실을 시사한다. 종합적으로 음악을 통한 정서 전달에 있어 연주자, 청자, 악기, 음악 스타일의 차이가 영향을 줄 수 있다는 사실을 확인하였으며 이러한 결과는 Scherer & Oshinsky(1977)가 언급하였듯 음악 연주가 다른 비언어적 의사소통 방법과 공유하는 특징이 있음을 시사한다.

• Journal of the Korean Ceramic Society
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• v.39 no.7
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• pp.675-679
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• 2002

To produce a strengthened glass, single ion exchange properties such as three-point bend strength and residual stress were investigated in soda-lime-silicate substrate glass for display use. The present work showed that the maximum value of strength was 62.5${\times}$10$\sub$6/ kg/㎡ after, the two-step single ion exchange process at 470$^{\circ}C$ for 1 h and 450$^{\circ}C$ for 24 h. As the result of the fracture analysis after bending test, the residual stress on the fractured surface of the strengthened glass increased the flexibility by means of absorbing the elastic deformation energy in the glass. Also, the effects of absorbing the elastic deformation energy were analysed by curvature change, number of multiple crack branches and brittleness.

• Journal of the Korean Chemical Society
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• v.21 no.5
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• pp.379-383
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• 1977

Since the organophilic bentonite disperses well in polymer matrix, a composite material of polymer and bentonite was studied for its mechanical properties. To increase the degree of dispersion and the bond in forces to the polymer matrix, bentonite, encapsulated by imidazoline, was used as a filler. Polyethylene powder of particle size of 100 mesh was used, and organophilic bentonite, so-called bentone, whose particle size was 250 mesh was also used in this experiment. V-type mixer was used for mixing and Banbury mixer was used for melt-blending. The sample specimen were made by heating the mixture in the plate press, and the specimen were formed as a sheet, exactly the same as the mold on the plate. Tensile strength, bending strength and compressive strength were studied specially. Tensile strength, elongation rate, bending strength and bending rate at constant pressure were decreased as the filler content increased. Compressive strength was increased as the filler content increased.