• Title/Summary/Keyword: 보 변형

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Exploring the Characteristics of Science Gifted Students' Task Commitment (과학 영재들의 과제집착력 특성 탐색)

  • Jang, Jyungeun;Chung, Yoonsook;Choi, Yanghee;Kim, Sung-Won
    • Journal of The Korean Association For Science Education
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    • v.33 no.1
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    • pp.1-16
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    • 2013
  • In this research, we tried to discover the characteristics of gifted students by analyzing their experience in showing task commitment. In order to do this, we asked science gifted students to specifically describe their experiences while deeply experimenting on a scientific cause or theory. From their responses, we inductively explored the characteristics of science gifted students by extracting and analyzing the characteristics that show task commitment. Consequentially, the characteristics of the gifted students are divided into nine categories, which are confidence, setting a challenging goal, challenging approach for solving problems, sense of potential control, loss of self-consciousness, time distortion, submission to difficult task, initiative, and endurance, all of which appear repeatedly among the gifted students. With consensus among three experts who have experience in research on gifted education, these nine characteristics can be categorized into 3 characteristics; challenge, flow, and willingness. The three characteristics such as challenge, flow, and willingness well represent a definition of task commitment. These characteristics can explain the level of task commitment exhibited by science gifted students. It is possible to develop the tool and framework for judging the task commitment of gifted students on the basis of their characteristics.

Characteristics and Phase Transition of Clay Minerals as the Results of Bentonite Weathering (벤토나이트의 풍화에 따른 점토광물의 상전이 및 광물특성)

  • 노진환;이석훈
    • Journal of the Mineralogical Society of Korea
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    • v.15 no.3
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    • pp.147-159
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    • 2002
  • Weathered bentonites occcur as surficial alterations of some domestic bentonite deposits in the Tertiary formations, with the thickness of less than about 50 cm, along naturally-formed weathering surface with slopping in gentle. 7 $\AA$-halloysite was found together with montmorillonite in the weathered bentonite. Compared to normal bentonite, the weathered one is generally more clay-rich and contains little amounts of original rock-forming minerals and residues. In the electron microscopy, fine-scale occurrence of the clay minerals tends to be somewhat discrete and segregated rather than closely associated. h curled margin of montmorillonite lamella is deformed to become obtuse in the weathered bentonite. Halloysite occurs as acicular to tubular crystals with the length of less than 2 $\mu$m and the width of about 0.3 $\mu$m, which commonly forms bundle-shaped aggregates. Electron microscopic observations on the fine-scale occurrence and texture of the wtathered bentonites indicate that the clay mineral transition from montmorillonite to halloysite has undergone without accompanying any intermediate phases of both clay minerals such as a mixed-layered type (M/H). The alteration reaction between these two clay minerals probably took place in the form of dissolution and precipitation mechanism in oxidation condition. An intense chemical leaching of SiO$_2$, Na, K and Ca might occur during the alteration reaction, forming a lot of dissolution cavity and residual concentration of A1$_2$O$_3$ and Fe, relatively. As the result of the chemical change, a fsvorable condition for halloysite formation seemed to be provided.

An Experimental Study on the Flexural Behavior of RC Beams Strengthened with NSM and EBR CFRP Strips (표면매입 및 외부부착 탄소섬유판으로 보강된 RC보의 휨 거동에 관한 실험 연구)

  • Lim, Dong-Hwan
    • Journal of the Korea Concrete Institute
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    • v.20 no.5
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    • pp.601-609
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    • 2008
  • The purpose of this study is to investigate the flexural strengthening effectiveness for the beams combined reinforced with NSM CFRP strips and EBR CFRP strips. To accomplish this objective, a total of nine concrete T beams were tested. From this study, it is found that the flexural stiffness and strength of the beams combined reinforced with NSM and EBR strips were significantly improved compared to the beams strengthened only with NSM CFRP strip. The maximum increase of flexural strength was 347% compared to the beam without CFRP strip. Failure of the beam combined reinforced with NSM and EBR strips (T shape) is initiated by debonding of EBR strips attached on the bottom face, and it was succeeded a part of separatio-n of NSM strips along the longitudinal direction and secondly failure of NSM strips was occurred, eventually sudden explosive failure with the separation of concrete cover in the shear region. This result shows that the NSM and EBR strips have good combination to resist applied load and the combined reinforcement with NSM and EBR strips can redistribute appropriately the total stress subjected concrete beam to the EBR and NSM strips.

Thermoelastic Aspects of the San Andreas Faults under Very Low Strength (낮은 강도를 갖는 산 안드레아 단층의 열탄성 특성)

  • Park, Moo-Choon;Han, Uk
    • Journal of the Korean earth science society
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    • v.21 no.3
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    • pp.315-322
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    • 2000
  • In this study, the data used for the models were a set of 56 geologic estimates of long-term fault slip rates. The hest models were those in which mantle drag was convergent on the Transverse Ranges in the San Andreas fault system, and faults had a low friction (${\mu}$= 0.3). It is clearly important to decide whether these cases of low strength are local anomalies or whether they are representative. Furthermore, it would be helpful to determine fault strength in as many tectonic settings as possible. Analysis of data was considered by unsuspected sources of pore pressure, or even to question the relevance of the friction law. To contribute to the solution of this problem, three attempts were tried to apply finite element method that would permit computational experiments with different hypothesized fault rheologies. The computed model has an assumed rheology and plate tectonic boundary conditions, and produces predictions of present surface velocity, strain rate, and stress. The results of model will be acceptably close to reality in its predictions of mean fault slip rates, stress directions and geodetic data. This study suggests some implications of the thermoelastic characteristics to interpret the relationship with very low strength of San Andreas fault system.

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Experimental Study for Structural Behavior of Embed Plate into Concrete Subjected to Welding Heat Input (매입강판 용접열에 의한 고강도 콘크리트 접합부 구조성능 영향평가에 관한 실험적 연구)

  • Chung, Kyung Soo;Kim, Ki Myon;Kim, Do Hwan;Kim, Jin Ho
    • Journal of Korean Society of Steel Construction
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    • v.25 no.5
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    • pp.569-578
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    • 2013
  • In a super-tall building construction, thick and large-sized embed plates are usually used to connect mega structural steel members to RC core wall or columns by welding a gusset plate on the face of the embed plate with T-shape. A large amount of heat input accumulated by weld passes causes the plates to expand or deform. In addition, the temperature of concrete around the plates also could be increased. Consequently, cracks and spalls occur on the concrete surface. In this study, the effect of weld heat on embed plates and 80MPa high strength concrete is investigated by considering weld position (2G and 3G position), edge distance, concrete curing time, etc. Measured temperature of the embed plates was compared with the transient thermal analysis results. Finally, push-out tests were performed to verify and compare the shear studs capacity of the embed plate with design requirement. Test result shows that the shear capacity of the plate is reduced by 14%-19% due to the weld heat effect and increased as the concrete curing time is longer.

Effect of parboiling on the physicochemical properties of immature barley kernels (Parboiling처리가 미숙보리곡립의 이화학적 특성에 미치는 영향)

  • Seog, Ho-Moon;Kim, Jong-Sang;Hong, Hee-Do;Kim, Sung-Soo;Kim, Kyung-Tack
    • Applied Biological Chemistry
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    • v.36 no.6
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    • pp.456-462
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    • 1993
  • Parboiling, a popular technology used to protect rice from nutrient loss during milling and to increase the shelf-life of rice, was applied to barley kernels, and its effect on nutrient retention and chemical composition was evaluated. Before 36 days after ear emergence, barley kernels showed water content higher than 40%, and parboiling without presoaking resulted in at least 43% of gelatinization degree. This implies that soaking, an important step of parboiling, is dispensable for barley at milky stage. Parboiling did make little change in the appearance of the kernel after 31 days from ear emergence. Nonreducing sugars such as sucrose and raffinose remained unchanged while reducing sugars of barley was decreased by parboiling, with exception that maltose increased. Pearling led to decrease in crude protein, fat, fiber and minerals of barley sampled and parboiled on 36th day from ear emergence. Free sugars in the parboiled barley also was reduced with increasing pearling rate. Vitamin $B_1$ content of the parboiled barley was $260\;{\mu}g\;per\;100\;g$ as dry basis at 50% pearling rate, compared to $36\;{\mu}g$ for raw barley at same pearling rate. Thus parboiling appeared to be very effective in the retention of vitamin $B_1$ during pearling.

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Transformation of Treasure Island in Feature Animation (애니메이션에 나타난 "보물섬" 의 변용)

  • Ahn, Young-Soon
    • Cartoon and Animation Studies
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    • s.10
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    • pp.137-148
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    • 2006
  • The purpose of this article is to study the aspects of transformation of Treasure Island(1883), Robert Louis Stevenson's novel in two feature animations (1987) of Osamu Dezaki and (2002) of Ron Clements and John Musker by analyzing characters. In the original novel, as a typical wicked villain and traitor, Long John Silver functioned as an obstacle in Jim Hawkins' Bildungsroman. And Osamu Dezaki laid great emphasis on the friendship between Jim and Stiver His might be an excellent example of the faithful adaptation. But in Disney's , from initial mistrust, to friendly co-worker, to mentor and protege, and finally, to mutual rescuers, Jim and Silver have created a permanent bond that can never be broken - their coming together has changed both their lives forever. Jim's voyage of searching for treasure is not just for the discovery of material riches unimaginable but also for the discovery of his own true worth. Making the Sliver/Jim relationship more focused, Jim ends up discovering not just an obvious treasure; he discovers an inner treasure. From this viewpoint, this feature film could be an outstanding transformative adaptation.

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Experimental and Numerical Studies on Application of Industrial Explosives to Explosive Welding, Explosive Forming, Shock Powder Consolidation (산업용 폭약을 이용한 폭발용접, 폭발성형과 충격분말고화에 관한 실험 및 수치해석적 연구)

  • Kim, Young-Kook;Kang, Seong-Seung;Cho, Sang-Ho
    • Tunnel and Underground Space
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    • v.22 no.1
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    • pp.69-76
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    • 2012
  • Theoretical backgrounds on the experimental methods of explosive welding, explosive forming and shock consolidation of powders are introduced. Explosive welding experiments of titanium (Ti) and stainless steel (SUS 304) plate were carried out. It was revealed that a series of waves of metal jet are generated in the contact surface between both materials; and that the optimal collision velocity and collision angle is about 2,100~2,800 m/s and $15{\sim}20^{\circ}$, respectively. Also, explosive forming experiments of Al plate were performed and compared to a conventional press forming method. The results confirmed that the shock-loaded Al plate has a larger curvature deformation than those made using conventional press forming. For shock consolidation of powders, the propagation behaviors of a detonation wave and underwater shock wave generated by explosion of an explosive are investigated by means of numerical calculation. The results revealed that the generation and convergence of reflected waves occur at the wall and center position of water column, and also the peak pressure of the converged reflected waves was 20 GPa which exceeds the detonation pressure. As results from the consolidation experiments of metal/ceramic powders ($Fe_{11.2}La_2O_3Co_{0.7}Si_{1.1}$), shock-consolidated $Fe_{11.2}La_2O_3Co_{0.7}Si_{1.1}$ bulk without cracks was successfully obtained by adapting the suggested water container and strong bonding between powder particles was confirmed through microscopic observations.

Flexural Behavior of Reinforced Concrete Beams Retrofitted with Modified Polymer Mortar System (폴리머 모르타르로 단면을 복구한 철근콘크리트 보의 휨 거동)

  • Hong Geon-Ho;Choi Eun-Gyu;Lee Su-Jin;Shin Yeong-Soo
    • Journal of the Korea Concrete Institute
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    • v.16 no.1 s.79
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    • pp.94-101
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    • 2004
  • This study shows the test results of seven RC beams retrofitted with modified polymer system and parametric study about the effects of tensile strength of retrofitting materials by analytical method on the flexural behavior. The main parameters are the retrofitted depth and length. The beams are loaded to the failure by four-point loading. Test results show that the effect of the retrofitted length on the structural behavior is more significant than that of depth. As the retrofitted depth is increased, the beams represents the brittle failure mode The non-linear analysis is carried out to grasp the effect of the tensile strength of retrofitting material on the structural behavior. As the retrofitted depth and length are increased, the tensile strength becomes more effective so these parameters should be considered to determine the retrofitted area. The analytical results show that failure strength is less than that of experimental results, but the stiffness is vice versa.

Petrology of Charnockite in Sancheong Area (산청지역에 분포하는 챠노카이트의 암석학적 연구)

  • Lee, Sang-Won;Ock, Soo-Seck;Lee, Young-Taek
    • Journal of the Korean earth science society
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    • v.25 no.4
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    • pp.251-264
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    • 2004
  • The Charnockite in Sancheong region is quarzofeldspathic rock containing orthopyroxene and garnet with a color dark than common granitic rocks. The Chamockite are mostly massive and medium to coarse-grained with K-feldspar phenocryst, but reveal weak foliation. The rock consist mainly of quartz, K-feldspar, plagioclase and orhopyroxene, with biotite, garnet, and anthophyllite. In petrochemistry, the Chamockite has 61-65% $SiO_2$ contents, varying gradually into the margin contacted with orthogneiss, which have compositions of felsic igneous rocks. Major element show almost systematical variation with those of the marginal orthogneisses, except the hornblende gneiss and anorthosite. The Charnockite and orthogneisses show the tholeiitic differentiational trend. Trace and rare earth element abundance patterns in the Charnockite show remarkable negative Sr and Eu anomalies similar to orthogneisses, but different from the hornblende gneiss and anorthosite. Eu contents of the Charnockite are richer than that of orthogneisses. The metamorphic condition of the Charnockite were tested by an orthopyroxene-garnet geotherrnorneter and a plagioclase-garnet geobarometer. Estimated P-T conditions are about $761^{\circ}C$ and 7 kbar at peak metamorphism, but $653^{\circ}C$ and 6.4 kbar at retrograde metamorphism. This suggests that the Charnockite have from an early stage of high-grade metamorphism to represent the granulite facies and then to a late stage medium-grade metamorphism belonging to the amphibolite facies.