• Title/Summary/Keyword: 속도 이방성

Search Result 199, Processing Time 0.022 seconds

Carbonation Characteristics of Alkali Activated Blast-Furnace Slag Mortar (알칼리활성 고로슬래그 모르타르의 탄산화 특성)

  • Song, Keum-Il;Yang, Keun-Hyeok;Lee, Bang-Yeon;Song, Jin-Kyu
    • Journal of the Korea Concrete Institute
    • /
    • v.24 no.3
    • /
    • pp.315-322
    • /
    • 2012
  • Alkali-activated slag (AAS) is the most obvious alternative materials that can replace OPC. But, AAS industrial usage as a structural material should be evaluated for its durability. Carbonation resistance is one of the most important factors in durability evaluation. Test results for 18 slag-based mortars activated by sodium silicate and 6 OPC mortars were obtained in this study to verify the carbonation property. Main variables considered in the study were flow, compressive strength before and after carbonation, and carbonation depth. Mineralogical and micro-structural analysis of OPC and AAS specimens prior to and after carbonation was conducted using XRD, TGA, FTIR FE-SEM. Test results showed that CHS was major hydration products of AAS and, unlike OPC, no other hydration products were found. After carbonation, CSH of hydration product in AAS turned into an amorphous silica gel, and alumina compounds was not detected. From the analysis of the results, it was estimated that the micro-structures of CSH in AAS easily collapsed during carbonation. Also, the results showed that this collapse of chemical chain of CSH lowered the compressive strength of concrete after carbonation. By increasing the dosage of activators, carbonation resistance and compressive strength were effectively improved.

Numerical Analysis of the Change in Groundwater System with Tunnel Excavation in Discontinuous Rock Mass (불연속 암반에서의 터널굴착에 따른 지하수체계 변화에 대한 수치해석적 연구)

  • Park, Jung-Wook;Son, Bong-Ki;Lee, Chung-In;Song, Jae-Joon
    • Tunnel and Underground Space
    • /
    • v.18 no.1
    • /
    • pp.44-57
    • /
    • 2008
  • In this study, a 2D finite-element analysis, using the SEEP/W program, was carried out to estimate the amount of groundwater flawing into a tunnel, as well as the groundwater tables around wetland areas during and after a tunnel excavation through rock mass. Four sites along the Wonhyo-tunnel in Cheonseong Mountain (Gyeongnam, Korea) were analysed, where the model damain of the tunnel included both wetland and fault zone. The anisotropy of the hydraulic conductivities of the rock mass was calculated using the DFN model, and then used as an input parameter for the cantinuum model. Parametric study on the influencing factors was perofrmed to minimize uncertainties in the hydraulic properties. Moreover, the volumetric water content and hydraulic conductivity functions were applied ta the model to reflect the ability of a medium ta store and transport water under both saturated and unsaturated conditions. The conductivity of fault zone was assumed ta be $10^{-5}m/sec\;or\;10^{-6}m/sec$ and the conductivity of grouting zone was assumed as 1/10, 1/50 or 1/100 of the conductivity of rock mass. Totally $6{\sim}8$ cases of transient flow simulation were peformed at each site. The hydraulic conductivities of fault zone showed a significant influence on groundwater inflow when the fault zone crossed the tunnel. Also, groundwater table around wetland maintained in case that the hydraulic conductivity of grouting zone was reduced ta be less than 1/50 of the hydraulic conductivity of rock mass.

Exploring Different Aspects of Otherness in Korean 'Dokkaebi' (한국 도깨비와 타자성의 색다른 모습)

  • Kyung-Seop Kim;Jeong-Lae Kim
    • The Journal of the Convergence on Culture Technology
    • /
    • v.10 no.6
    • /
    • pp.1-9
    • /
    • 2024
  • This paper explores the concept of otherness through the lens of Dokkaebi, a figure in Korean folklore. Dokkaebi serves as a monster that is both familiar and distant-a 'familiar trap' or 'well-known monster'-reflecting its nature as a marginal being. Though far from divine, Dokkaebi is also not human, existing in a liminal space that allows it to wander among us even today. Outsiders, gods, and monsters often reveal the cracks within the human psyche, illustrating our divisions between consciousness and the unconscious, the familiar and the unfamiliar, and the same and the different. Outsiders and monsters emerge from our tendency to other various entities. This paper discusses how Dokkaebi embodies the characteristics of a 'subjectivized other,' a 'dual other,' and an 'other that generates a double self. As a 'subjectivized other,' Dokkaebi transcends the narrative of a monster othered by humanity, revealing the relationship between the subject and the 'internalized other.' As a 'dual other,' Dokkaebi mimics the ways in which men other women, bringing this dynamic vividly to life within the tales. Lastly, functioning as an 'other that generates a double self,' Dokkaebi prompts us to consider how we treat the other within ourselves and the dangers posed by that inner other.

Weathering Sensitivity Characterization for Rock Slope, Considering Time Dependent Strength Changes (시간에 따른 강도변화를 고려한 암반사면의 풍화민감특성 분석)

  • Lee Jeong-Sang;Bae Seong-Ho;Yu Yeong-Il;Oh Joung-Bae;Lee Du-Hwa;Park Joon-Young
    • Tunnel and Underground Space
    • /
    • v.16 no.2 s.61
    • /
    • pp.109-134
    • /
    • 2006
  • Rocks undergo weathering processes influenced by changing in pressure-temperature condition, atmosphere, underground water, and rainfall. The weathering processes change physical and chemical characteristics of the rocks. Once the rocks are weathered, the characteristics of them are changed and, because of the changing, several disadvantages such as rock slope failures and underground water spouts are can occur. Before we cut a large rock slope, therefore, we must analyze current weathering conditions of rocks and predict weathering processes in the future. Through the results of such analyses, we can judge reinforcement works. In order to comply with such requests, chemical weathering sensitivity analysis which was analyzed from chemical weathering velocities and other characteristics of rocks has been applied in several prior construction works in Korea. But, It is defective to use directly in engineering fields because it was developed for soils(not rocks), it has too mny factors must be considered and the relationships between the factors are not clear, and it is hard to explain the weathering processes in engineering time range. Besides above, because it has been used for isotropic rocks, this method is hard to apply to anisotropic rocks such as sedimentary rocks. Acceding to studies from morphologists (e.g. Oguchi et al., 1994; Sunamura, 1996; Norwick and Dexter, 2002), time dependent strength reduction influenced by weathering shows a negative exponential function form. Appling this relation, one can synthesize the factors which influence the weathering processes to the strength reduction, and get meaningful estimates in engineering viewpoint. We suggest this weathering sensitivity characterization method as a technique that can explain time dependent weathering sensitivity characteristics through strength changes and can directly applied the rock slope design.

Influence of Microcracks in Geochang Granite on Brazilian Tensile Strength (거창화강암의 미세균열이 압열인장강도에 미치는 영향)

  • Park, Deok-Won
    • Korean Journal of Mineralogy and Petrology
    • /
    • v.34 no.3
    • /
    • pp.193-208
    • /
    • 2021
  • The characteristics of the microcrack lengths(①), microcrack spacings(②) and Brazilian tensile strengths(③) related to the six directions of rock cleavages(H2~R1) in Geochang granite were analyzed. First, the 18 cumulative graphs for the above three major factors representing unique characteristics of the rock cleavages were made. Through the general chart for these graphs classified into three planes and three rock cleavages, the 28 parameters on the length, spacing and Brazilian tensile strength have been determined. The results of correlation analysis among these parameters are summarized as follows. Second, the above parameters were classified into six groups(I~VI) according to the sorting order on the magnitude of parameter values among three rock cleavages and three planes. The values of parameters belonging to group I and II are in order of R(rift) < G(grain) < H(hardway) and H < G < R. The values of the 8 parameters on the length of line(os2, 𝚫s, 𝚫L and oSmean), the exponent(λLmean and λSmean), the slope(amean) and the anisotropy coefficient (Anmean) are in order of R < G < H and H'(hardway plane) < G'(grain plane) < R'(rift plane). Third, the noticeable differences in distribution patterns among the six types of charts for three planes and three rock cleavages are as follows. From the chart for three planes, the values of 𝚫L, 𝚫s and 𝚫σt, corresponding to the distance between two points where the two fitting lines meet on the X-axis, increase in the order of R' < H' < G'. In particular, the two graphs of R2 and G2 related to the length and Brazilian tensile strength are almost parallel to each other and show the distribution characteristics of hardway plane. Among the graphs related to the Brazilian tensile strength, the overall shape for hardway plane is similar to that for grain. From the chart for three rock cleavages, the slopes of the graphs related to the length increase in the order of R < G < H, while those of the graphs related to the spacing and Brazilian tensile strength decrease in the order of R < G < H. Lastly, the characteristics of variation among the six rock cleavages, the three planes and the three rock cleavages were visualized through the correlation chart among the above parameters from this study.

Estimation of Nitrogen Mineralization of Organic Amendments Affected by Nitrogen Content in Upland Soil Conditions (밭토양 조건에서 질소함량별 유기자원의 질소 무기화율 추정)

  • Lim, Jin-Soo;Lee, Bang-Hyun;Kang, Seung-Hee
    • Korean Journal of Environmental Agriculture
    • /
    • v.38 no.4
    • /
    • pp.262-268
    • /
    • 2019
  • BACKGROUND: To investigate mineralization characteristics of organic resources in the soil, five materials (rice straw, cow manure sawdust compost, microorganism compost, mixed oil-cake, and amino acid fertilizer) were treated according to the nitrogen content, and an indoor incubation experiment was conducted for 128 days. The results of this analysis were applied to determine the nitrogen mineralization pattern of these organic resources. METHODS AND RESULTS: During the constant temperature incubation period, the nitrogen net mineralization rate of the organic resources was the highest in the amino acid fertilizer with the highest nitrogen content, and the lowest in the rice straw with the lowest nitrogen content. A positive correlation (0.96) was observed between the potential nitrogen mineralization rate and total nitrogen content. The mineralization rate constant, k, was negatively correlated with the organic matter (-0.96) and carbon content (-0.97). The nitrogen mineralization rate during the first cropping season, as estimated by the model, was 6.6%, 11.6%, 30.9%, 70.7%, and 81.0% for the rice straw, the cow manure sawdust compost, the microorganism compost, the mixed oil-cake, and the amino acid fertilizer, respectively. CONCLUSION: The nitrogen mineralization rate varies depending on the type of organic resources or the nitrogen content; thus, it can be used as an index for determining the nitrogen supply characteristics of the organic resource. Organic resources such as compost with low nitrogen content or those undergoing fermentation contain organic nitrogen. Organic nitrogen is stabilized during the composting process. Therefore, as the nitrogen mineralization rate of these resources is lower than that of non-fermented organic resources, it is desirable to use the fermented organic materials only to improve soil physical properties rather than to supply nutrients for the required amount of fertilizer.

Electrical and Magnetic Properties of Magnetite Powder during a Verwey Transition (Verwey 전이와 마그네타이트의 전기적 및 자기적 특성)

  • Yoon, Sunghyun
    • New Physics: Sae Mulli
    • /
    • v.68 no.12
    • /
    • pp.1302-1307
    • /
    • 2018
  • The crystallographic, electrical and magnetic behaviors of magnetite powder in the vicinity of its Verwey transition were investigated in this study. Magnetite was prepared by synthesizing a nanoparticle precursor and then annealing it at $800^{\circ}C$ for 1 h under a dynamic vacuum. Crystallographic and morphology analyses were done by using scanning electron microscope (SEM) and X-ray diffraction (XRD). The electrical and the magnetic properties were examined by using $M{\ddot{o}}ssbauer$ spectroscopy, vibrating sample magnetometer (VSM) and resistivity measurement. Both the magnetic moment and the resistivity showed discontinuous changes at the Verwey transition temperature ($T_V$). The temperature dependence of magnetic anisotropy constant showed a monotonic decrease with increasing temperature, with slight dip near $T_V$. $M{\ddot{o}}ssbauer$ spectra showed the superposition of two sextets, one from the tetrahedral (A) and the other from the octahedral (B) sites. The results revealed that identical charge states existed in the B site at temperatures both above and below $T_V$. A coordination crossover resulted in a transition from an inverse to a normal spinel at or close to $T_V$.

A comparative study on Diaspora consciousness of polish emigrants before and after the transformation of the political system reflected in the polish literary works (2) (체제전환 이전과 이후 폴란드 문학에 나타난 폴란드 이민자들의 디아스포라적 의식 비교 연구 (2))

  • Choi, Sung Eun
    • East European & Balkan Studies
    • /
    • v.35
    • /
    • pp.153-186
    • /
    • 2013
  • Literature has been special for the Polish who suffered from the numerous invasions from surrounding countries for her geographical location at the center of Europe. In the late 18th century at a time when Poland was divided and ruled by Russia, Prussia and Austria, literature played an important role in uniting Poland. During the 2nd world war in which Poland was occupied by the Soviet Union and by Germany, and during the Cold War period under socialism system(1948~1989), the Polish literature was in the front to keep unique national culture with overseas migration community at the center. The Polish Diaspora literature from 19th century up to now has naturally embodied national sufferings from foreign powers in their literary tradition linked to the problem of 'migration'. In addition, they belong to other cultural sphere, but keep their own unique identity, which is similar to Korean Diaspora literature to a great degree. This study has two stages. In the first stage, it figures out the formation and trend of the Polish Diaspora literature followed by their meaning in the history of Polish literature. In the second stage, specific texts (two dramas) are analyzed before and after system transition in 1989. * Before system transition: S. Mrożek, Emigranci (1974), * After system transition: J. Głowacki, Antygona w Nowym Yorku (1992) Mrożek and Głowacki had themselves migration experiences with high achievement and recognition in literature not only in Poland but also in the world. In their works, hardships as 'strangers' in foreign countries, emotional wandering and agony, nostalgia to lost home land and exploration of identity were described vividly. By comparing the 2 literature texts, this study attempts to trace the change of Diaspora consciousness which Polish migrants experienced in foreign countries with different political system like socialism and capitalism.

A Study on the Visions of Zechariah in the Old Testament from a Perspective of Analytical Psychology (구약성서 '스가랴'서의 환상에 대한 분석심리학적 연구)

  • Sang Ick Han
    • Sim-seong Yeon-gu
    • /
    • v.29 no.1
    • /
    • pp.1-45
    • /
    • 2014
  • Mystic experience such as seeing an vision could be explained as experiencing elusive and mysterious unique existence in religious way. In depth psychology, which is based on unconsciousness like analytical psychology, this could be explained as a something that gives a meaning of life and purpose through discovering health and healing. The importance of primodial experience in depth psychology is that it can possibly discover the base of present acts. In Christian theology, symbolic mystery and truth of religious experience that appear in Christian tradition have interest on human situation. These two fields' approach methods are different, but both show common interest on unique experience which can be said properly as raw experience. Various visions appear in many parts of the Bible. Among many visions, the book of Zechariah, one of the 12 Prophets, describes rich and diverse 8 visions through chapter 1 to chapter 8. However, due to the Genre of revelation, it lacks historicity, and because of vagueness and symbolic meanings, its visions are hard to understand and interpret. Theologically, visions of Zechariah show communality of Israelites by reconstructing kingdom of Judah and church in a way of historical circumstances. Though, these visions could deliver the meaning of an ethnical aspect as reporting continuous conversation between the God and humans. Furthermore, it could mean a personal aspect of the Prophet Zechariah as reaching for a opportunity of new change. Moreover, those who read these visions could try to interpret the meanings of various images which represent meeting mysterious existences. Therefore, the Author would concentrate on the fact that 8 visions in the book of Zechariah, which has not been received much attention to neither Christians nor non-believers, develop in chiastic structure (stylistic contrast), so that tries to interpret the first, second, seventh, and the eighth visions in analytic psychology way. In visions of Zechariah, excepting the 4th vision which probably was inserted later, rest of 7 visions each shows the stage of the hours of darkness. 1st to 3rd visions represent evening, 5th vision represents deep in the night, and 6th to 8th visions represent dawn to morning. Moreover, since structure of visions arranged in chiastic way, horse appears in 1st and 8th vision, measuring rope and measure tools are used as main motif in 2nd and 7th vision. However, same motifs could have different symbolic meanings and roles as visions are formed in different situations and conditions. In the first vision, angels who ride horses look around the world and report it is calm and peaceful. Concerning the political situation back in the day, the world being calm and peaceful in the beginning of evening means that it is not ready to change to a whole new world. Psychologically, if there is no readiness to adopt new world, it means being hopeless. It is sending you a message to get out of those kinds of situation. Moreover, appearance of four angels who rode red, brown, and white horses to a myrtus tree in the valley means that it is time for individuation and it is right and good timing for changing. In second vision, you will be able to see that Israelites had long years being caught in the shadows by foreign country, and long years succumbed by the strength of four horns, which shows the progress of renewing strength and being oneness with oneself from overwhelmed situation by paternity. In seventh vision, meaning of two women bringing the godness of the sky, who were locked up in a rice basket, back to the temple in Babylon is going towards in a level of Self-actualization by separating one's ego captured excessively by matherhood and putting back to a place where it was before. In eighth vision, chariots pulled by horses are scattered far and wide, and horses which went to north had rest in the land of North. After horses and chariots are seen between two mountains of bronze with the image of Self and anima/animus. These images can be explained as the changing progress are almost completed and the God and human, in other words Self and ego are being united and is now time for rest. All of 8 visions contains the conversation between angel and Zechariah who willing to know the meaning of visions. Zechariah asks the angel actively about the meaning of visions because of his wish for Israelites to return home and rebuild church. Conversation among the God, Zechariah, who asks questions until he knows everything, an Angel, who gives answer to given questions, is conversation between ego and anima/animus. Eventually, it is a conversation between Self and ego.