• Title/Summary/Keyword: foreign material

Search Result 665, Processing Time 0.03 seconds

The Physical and Mechanical Properties of No-Fines Lightweight Concrete Using Synthetic Lightweight Coarse Aggregate (인공경량조골재(人工輕量粗骨材)를 사용(使用)한 무세골재(無細骨材) 경량(輕量)콘크리트의 물리(物理)·가학적(加學的) 특성(特性))

  • Kim, Seong Wan;Min, Jeong Ki;Cho, Seung Seup;Sung, Chan Yong
    • Korean Journal of Agricultural Science
    • /
    • v.23 no.1
    • /
    • pp.39-50
    • /
    • 1996
  • The normal cement concrete is widely used material to build the construction recently, but it has a fault to increase the dead load on account of its unit weight is large compared with strength. So, many engineers are continuously searching for new materials of construction to provide greater performance at lower density. Many studies were carried out on the lightweight aggregate concrete in foreign country in the latter half of the 19th century, therefore lightweight aggregate concrete has been used successfully for many years for structural members. The main purpose of the work described in this paper were to establish its physical and mechanical properties of no-fines lightweight concrete using synthetic lightweight coarse aggregates. Test results are summarized as follows ; The water-cement ratio was shown less than 33% in use synthetic lightweight coarse aggregates, unit weights of synthetic lightweight concrete was shown less than $1,800kg/m^3$ and compressive strength was higher than $200kg/m^2$. And the pulse velocity was more than 3,000m/sec. The relationship of compressive strength between unit weight and pulse velocity was shown to be approximately linear.

  • PDF

Hydrochemical and Isotopic Properties of the Thermal Spring Water from Chonju Jukrim District, Korea (전주 죽림지역 온천수의 화학적 및 동위원소적 특성)

  • Na, Choon-Ki;Lee, Mu-Seong;Lee, In-Sung;Park, Hee-Youl;Kim, Oak-Bae
    • Economic and Environmental Geology
    • /
    • v.30 no.1
    • /
    • pp.25-33
    • /
    • 1997
  • The purpose of this study is to examine the feasibility of using stable isotopes as a hydrologic tracer, and to elucidate the groundwater circulation system and the source of S component dissolved in thermal water of the Chonju Jukrim thermal spring district based on the O, H and S isotopic variabilities of environmental materials including bedrock, rainwater, surface water, shallow subsurface water and thermal spring water. The ${\delta}^{18}O$ and ${\delta}D$ of subsurface waters and surface water show highly restricted range and plotted on the same meteoric water line as a ${\delta}D=8{\delta}^{18}O+19$ line, and derivate from the mean annual isotopic composition of the rain water but are analogous to those of rain waters precipitated during winter season, indicating that ground waters are originated from the meteoric water and are strongly affected by the seasonal variation of air mass. Thermal spring waters are more depleted in ${\delta}^{18}O$ and ${\delta}D$ than those of shallow ground water and surface water. It can be explained by the difference of recharge area. The hydrochemical properties of subsurface waters and surface water devide into two groups: $Ca(HCO_3)_2$ type including shallow subsurface water and surface water, and $Na(HCO_3)$ type of thermal spring waters. The ${\delta}^{34}S$ values of thermal spring water show very high positive and quitely distinct from those of shallow subsurface water and surface water that are similar to those of bed rocks, indicating that sulfate dissolved in thermal spring water has not only a terrigenic origin, but also originates partially from the foreign source containing very heavy ${\delta}^{34}S$ component such as an ancient sea water. However, the presence of $H_2S$ can not be ignore the affact of the isotopic fractionation to explaine the heavy ${\delta}^{34}S$ of thermal spring water. Overall, the Oxygen and Hydrogen stable isotopes can identify the source and the circulation system of the natural waters and the S-isotopes can provide a crucial clue on tracing the dissolved material transports in the circulation system of the natural water.

  • PDF

Basic Research of Self Compacting Concrete Using Alkali-Activated Slag Binder (알칼리 활성 슬래그 결합재를 이용한 자기충전 콘크리트의 기초 연구)

  • Song, Keum-Il;Shin, Gyeong-Sik;Gong, Min-Ho;Song, Jin-Kyu
    • Journal of the Korea Concrete Institute
    • /
    • v.25 no.6
    • /
    • pp.657-665
    • /
    • 2013
  • The purpose of this study is the basic research of self-compacting concrete using Alkali-Activated Slag (AAS) binder in order to emphasize the durability of structures and facilitate casting the fresh concrete in field. The AAS binder emitted low carbon dioxide ($CO_2$) is eco friendly material of new concept because AAS products not only emit little $CO_2$ during production but also reuse the industrial by-products such as ground granulated blast-furnace slag (GGBS) of the steel mill. Until now, almost of domestic and foreign research are using Ordinary Portland Cement (OPC) for self-compacting concrete, and also, nonexistent research about AAS. The self-compacting concrete must get the performance of flowability, segregation resistance, filling and passing ability. Nine concrete mixes were prepared with the main parameter of unit amount of binder (400, 500, 600 $kg/m^3$) and 3 types of water-binder (W/B) ratio. The results of test were that fresh concretes were satisfied with flowability, segregation resistance, and filling ability of JSCE. But the passing ability was not meet the criteria of EFNARC because of higher viscosity of AAS paste than OPC. This high viscosity of AAS paste enables the manufacturing of self compacting concrete, segregation of which does not occur without the using of viscosity agent. It is necessary that the development of high fluidity AAS binders of higher strength and the study of better passing ability of AAS concrete mixes in order to use self compacting AAS concrete in field.

Developing a Sensory Ride Film 'Dragon Dungeon Racing' (효율적인 입체 라이드 콘텐츠 제작을 위한 연구)

  • Chae, Eel-Jin;Choi, Chul-Young;Choi, Kyu-Don;Kim, Ki-Hong
    • The Journal of the Korea Contents Association
    • /
    • v.11 no.2
    • /
    • pp.178-185
    • /
    • 2011
  • The recent development of 3D and its application contents have made it possible for people to experience more various 3D contents such as 3D/4D, VR, 3D ride film, I-max, sensory 3D games at theme parks, large-scale exhibitions, 4D cinemas and Video ride. Among them, Video ride, a motion-based genre, especially is getting more popularity, where viewers are immersed in and get indirect experiences in virtual reality. In this study, the production process of the genre of sensory 3D image getting attention recently and ride film are introduced. In the material selection of 3D images, the space and the setting up which is suitable to the fierce movement of rides are studied and some examples of the realization of creative direction ideas and effective technologies using the functions of Stereo Camera which has been first applied to MAYA 2009 are also illustrated. When experts in this 3D image production create more interesting stories with the cultural diversity and introduce enhanced 3D production techniques for excellent contents, domestic relevant companies will be sufficiently able to compete with their foreign counterparts and further establish their successfully unique and strong domains in the image contents sector.

A Study of Collection Development Policies of the University Libraries in Korea (한국의 종합대학도서관 장서개발정책에 관한 연구)

  • 손정표
    • Journal of Korean Library and Information Science Society
    • /
    • v.11
    • /
    • pp.101-142
    • /
    • 1984
  • This study is a survey of collection development policies in the 40 university libraries among 42 in Korea as of 1984. The survey used a questionnaire with 36 questions concerning the basic elements of the collection development policy. The survey results revealed many problems demanding correction. The measures to correct the problems in the university libraries are as follows. 1. It is desirable that the libraries should have a collection development policy statement written and adopted for the systematic collection building. 2. It is advisable that the libraries should include a function of the materials selection among other various functions of the Library Committee for the purpose of informing administrators of the goals of the libraries and the validity of the budgetary allocation. 3. It is desirable that each library should organize the Collection Development Committee for minimizing the possibility of personal bias on the part of the individual selectors. 4. It is advisable that the primary responsibility for materials selection should be delegated as follows: for the materials for faculty research, to the faculty members; for the other collections, to the professional staff of each department; for the final review of whether or not to purchase, to the Collection Development Committee. 5. It is desirable for the purchase priority of materials to be set up in accordance with the order of 6 levels of collection development. 6. It is advisable that the libraries should, as top priority, purchase materials in direct su n.0, pport of the undergraduate and graduate academic programs, and in subject matter areas other than languages and literature, Korean materials should have not only the higher priority than the foreign language materials, but also maintain the comprehensive collection level. 7. It is desirable that the special collections should be purchased by special funds from the authority, and the special collections librarian should have the responsibility of the materials selection under the advice of the faculty members relating to the subject area. 8. It is advisable that duplicate copies should be bought only for high use items, but for reserve books, by the program enrollment, and textbooks should not be bought in general, except as su n.0, pplemental materials for course work in which they are necessary and heavily used. 9. It is reasonable that the material budget should be distributed as follows: by the ratio for distributing funds, about 60-70% for the library and 30-40% for departments; by the type of materials, about 50% for books, 40% for periodicals and 10% for other materials, or when not bought other materials, about 50-60% for books and 40-50% for periodicals. In addition, it is desirable that undergraduate class enrollment, graduate class enrollment, undergraduate majors, graduate majors, average book cost in the discipline, number of faculty, and use rate by subject should be considered as the factors for the allocation of funds by department, and special consideration should be given to newly-founded departments so the library holdings can be adequate to su n.0, pport them.

  • PDF

A study of Movement on Modern Fashion (현대 의상에 나타난 움직임의 표현성)

  • 이상례;임영자
    • Journal of the Korean Society of Costume
    • /
    • v.20
    • /
    • pp.125-135
    • /
    • 1993
  • The purposes of this research are firstly to define the characteristics of movement on the costume, secondly to demonstrate that fine art, expecially in relation to kinetic art, has become a good motif in modern costume de-sign, and thirdly to examin the characteristics of movement as shown in modern costume de-sign. For this study, we selected and analyzed some costume designs among those introduced in fashion magazines, which are Collections, Fashion-Preview, Fashion Show, Collezioni, and L'Officiel that have been issued since 1988. As this research is carried out only through the analysis of pictures, it is not ac-companied by a study on material itself. The result of this study is that the ex-pression of movement on modern fashion can be shown in two ways, one is the inclusive and subordinate movement expressed on the cloth-ing according to the motion of body when they are worn, and the other is the movement caused by the very designs of clothing. And the latter can be also divided in two ways, the illusionistic movement and the actual move-ment. The expression of actual movement is made through the emphasis of direction, rhythm, and dimension of the costume. And the illusionistic movement is expressed by the de-sign to which the textile pattern or reflection of light is applied so that the movement is larger than the actual movement. A sense of direction expressed on the cos-tume by the actual movement creates a light rhythm and adds interest to the costume. This reflects a part of psychology of modern men who are not accustomed to the statics. In the rapidly changing society of information our modern men seek after movement even in the statics. It is also true in the clothing and they seem to get a psychological rest through the immediated visual change as shown in fashion design. The simple and cheerful rhythm expressed by the illusionistic movement on the costume is attempted in order to overcome the static tediousness caused by simple design. These elements of movement cause the en-largement of visible range and create another enlarged shape other than the real one, so that they come to remove the dullness and monot-ony in costume design and provoke interest in costume, as if kinetic art reveals the various aspects that transcend the closed area of fine art upon the motif of 'movement'. finally, as this paper deals with the ex-pression of movement as shown in the costume design which prevailed after 1988, it is desir-able hereafter to study more about the fashion since 1950 when kinetic art began in earnest, along with the comparative study on the ex-pression of movement in our Korean designer's and foreign designer's works.

  • PDF

Developing Wastepaper Demand-Supply Model and Policy Measures to Increase Wastepaper Recycling Rate (폐지시장(廢紙市場)의 수요(需要)·공급(供給) 모델의 개발(開發)과 회수율(回收率) 제고방안(提高方案))

  • Choi, Kwan;Han, Sang-Yoel
    • Journal of Korean Society of Forest Science
    • /
    • v.83 no.2
    • /
    • pp.133-147
    • /
    • 1994
  • Wastepaper recycling has significant implications not only in providing scarce raw material input for the paper industry but in environmental concerns such as reducing solid waste disposal, energy conservation and preservation of forest resources. The objectives of this study was (1) to develop an econometric model of demand for and supply of wastepaper, (2) to forecast wastepaper consumption and price to the year 2000 applying the econometric models estimated and (3) to estimate the elasticity of variables which are included in the wastepaper supply and demand equations. In this study wastepaper was classified into three groups, old newsprint, old corrugated and mixed For each group such as demand and supply equation were estimated. The demand equations were estimated as a function of paper and paper product consumption and wholesale price index and supply equations as a function of wastepaper price, one year lagged paper and paperproduct consumption and transportation price. Applying the econometric models to forcasting results in the future consumption and supply of wastepaper projected as 11.645 million MT and 7.396 million MT in 2000, respectively. The rate of wastepaper self-supply is forcasted about 63.5% in 2000. Especially, the rate of old neswprint self-supply is predicted about 16% which means about 2.2 million MT of old newsprint should be imported from foreign countries. Lastly, some policy measures to promote wastepaper recycling rate based upon economic and physical characteristics of wastepaper and market structure are suggested.

  • PDF

A Study of the Preferred Methods and Strategies of Science Learning in Middle School Students (중학교 학생의 과학 학습 방법 및 전략에 관한 연구)

  • Kim, Hyo Jin;Kim, Youn Kyoo;Park, Hyun Ju
    • Journal of the Korean Chemical Society
    • /
    • v.43 no.5
    • /
    • pp.552-563
    • /
    • 1999
  • The study investigated and analyzed the middle school student's science textbook learning methods and strategies. The Preferred Mehtod of Study (PMOS) and a clinical interview method were utilized. Results indicate that there is a meaningful and significant positive correlation between the number of times students read a chapter of the science textbook and their science grade point. Students do not tend to alter learning strategies dependent upon the subject matter studied, but easily alter stratgies dependent upon the types of the test. Most students could not construct "organiztional tools" such as a summary, a chart, a talbe, or a figure when they study textbook, but might pursure and prefer only one method when they choose their learning strategise. Very few students (less than 1%) among those queried consciously try to connect between prior knowledge and new concepts in the textbook. Even though students choose the textbook for learning science in the beginning, they prefer to stick to reference and exercise materials. Therefore, detailed and direct studise of the student's learning methods and strategies, as well as research on cognitive psychology and motivational psychology, are necessary in order to develop a new textbook with student-based learning materials. By understanding the student's konwledge level through investigation of his or her learning style, an effective science education program can be realized. Finally, the role of the textbook as a tezching/learning material can be maximized by investigating and understanding the student's learning method and strategy with emphasis on reciprocal action between textbooks.

  • PDF

A Study on Oriental Embroidery through the Modern Fashion (현대(現代)패션에 나타난 동양자수(東洋刺繡)에 관(關)한 연구(硏究))

  • Kim, So-Young;Shim, Hwa-Jin
    • Journal of Fashion Business
    • /
    • v.6 no.2
    • /
    • pp.41-52
    • /
    • 2002
  • At the beginning of the modern times, orientalism and ethnic character was the main stream of current fashion. Early in the twentieth century, orientalism had a tremendous affect on various areas of society, culture, and art. Particularly, it inspired and activated the design of costume. A great variety of colors and construction of the Orient and geometrical simplicity were based on the creation of modern costume. Ethnic placed weight on the Orient because Japan strengthened competitiveness and China opened the door to foreign countries. Therefore, a large number of the oriental costume produced by a variety of fashion designers. The oriental handicraft, motif and colors of the traditional costume have been used in modern costume. In addition, they are precious ideas for designers. This thesis is about a Study on costume embroidery close to fashion through the oriental embroidery and the concept of oriental embroidery. It is also a study on patterns, skills and colors of the oriental embroidery shown in modern fashion and practical use through the designers works. First, concept, process of change, patterns, skills and colors of the oriental embroidery are mainly discussed. 1.The oriental embroidery consists of life, Buddhism, appreciation and costume embroidery. Embroidery was widely used for a variety of purposes. First, it is to make a good impression and beauty. Second, to decorate many kinds of patterns and shapes. Last, to indicate social status and stages. 2.The origin of the oriental embroidery started in Persia. was It greatly developed in Iran and was introduced in Korea via China. We are reminded of the oriental embroidery of China. China is the original place of oriental embroidery. Oriental embroidery has developed the peculiar embroidery according to each climate, custom and nationality. On the basis of these, the practical use of the oriental embroidery on modern fashion is presented through patterns, skills and colors which leads Korean designers use. Even though the oriental embroidery is not very popular among people owing to a great deal of cost and a demand for labor, the patterns and colors of the embroidery has been already familiar with the contemporaries A more profound study on the oriental embroidery will supply a great deal of material and ideas to the fashion industry. Moreover, an effort to raise self-pride in traditional culture will be also in need.

Behavior of Hybrid Stud under Compressive Load (복합스터드의 압축 좌굴 거동)

  • Lee, Sang Sup;Bae, Kyu Woong
    • Journal of Korean Society of Steel Construction
    • /
    • v.16 no.5 s.72
    • /
    • pp.609-619
    • /
    • 2004
  • An investigation was conducted on the activities around Europe in order to solve the problem of the thermal bridging of steel studs, which had caused a significant disadvantage. This study included the following: diminishing the contact area between the studs and the sheathing, lengthening the heat transfer route, replacing the steel web with a less conductive material, and placing foam insulation in locations where the thermal shorts are most critical. Although energy efficiency is usually the focus of such foreign cases because their stud application is mostly limited to low-rise residential buildings, both structural and thermal performance are taken into consideration in this study because these target middle-story buildings. A hybrid stud composed of steel and polymer was also developed. This hybrid stud, which is 150 SL in size, is made of a galvanized steel sheet (SGC58) and a glass fiber reinforced polymer (GFRP) withepoxy bonding. A total of 32 specimens were manufactured. Its parameters comprise two types of connection detail,s: the thickness of steel (1.0mm and 1.2mm) and of the GFRP (4mm-4ply and 6mm-6ply), and the ratio of the length to the depth (L/D = 3, 6, 9, 12). Steel stud specimens with the same conditions were compared to the hybrid stud. The test revealed that in the case of the steel specimen with a thickness of 1.0mm, the maximum load of hybrid studs increased an average of 1.62 times comparedto that of the steel stud. In the case of the steel specimen with a thickness of 1.2mm, on the other hand, the average increase was 1.46times. All specimens showed full composite action until the collapse.