• Title/Summary/Keyword: stratum

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A Study on the Stress Distribution beneath Loaded Ground Surface Area of Double Strata Ground on Soft Clay Layers (연약점토층위 이층지반 지표면 재하시 지중응력 특성연구)

  • Lim, Jong-Seok;Lee, In-Hyung
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2005.10a
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    • pp.423-428
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    • 2005
  • If the load of constructing vehicles during the construction work acts on the road or the ground surface on the soft ground, due to the excess stresses in soils the trafficability of the vehicles influences the constructing efficiency, constructing period and so on. Stress distribution in soils is the very important element to design and to solve the problems of settlement, safety of foundations and trafficability of constructing vehicle in civil engineering. This research represents the comparative estimation of the actual and theoretical measurement on the underground stress of outer layer for each soil after the observation of each top soil layer for its vertical and horizontal stress in (1)homogeneous sand ground (2) weak stratum with the sand soil (3) weak stratum with gravel of the soil model, and it also investigates the effect of subsidence of ground by the repeated load. The underground stress turn out to be different in the value of theoretical and actual measurement after the trial examination of model.

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Analysis of Dynamic Interaction between Rigid Surface Foundations by 3-D Homogeneous Strip Hyperelement (3차원 Homogeneous Strip Hyperelement를 이용한 표면 강체 기초간 상호 작용 해석)

  • 김재관
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1997.10a
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    • pp.109-116
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    • 1997
  • The contiguous or adjacent foundations are always coupled through the soil. Hence their behavior is quite different due to the interaction effects between or among the foundations. The interaction effects can be very pronounced if the distance between them is very close. An 3-D homogeneous strip hyperelement is developed to analyze the dynamic interaction between rectangular or irregular shape found ations. The effects of interaction on the dynamic behaviors of the adjacent rigid rectangular foundations. The effects of interaction on the dynamic behaviors of the adjacent rigid rectangular foundations. The effects of interaction on the dynamic behaviors of the adjacent rigid rectangular foundations resting on the surface of a stratum are stratum are studied using the newly developed method.

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Coupled Nonlinear Finite Element-Boundary Element Analysis of Nuclear Waste Storage Structures Considering Infinite Boundaries (비선형 유한요소-경계요소 조합에 의한 핵폐기구조체의 무한영역해석)

  • 김문겸;허택녕
    • Computational Structural Engineering
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    • v.6 no.4
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    • pp.89-98
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    • 1993
  • As the construction of nuclear power plants are increased, nuclear wastes disposal has been faced as a serious problem. If nuclear wastes are to be buried in the underground stratum, thermo-mechanical behavior of stratum must be analyzed, because high temperature distribution has a significant effect on tunnel and surrounding stratum. In this study, in order to analyze the structural behavior of the underground which is subject to concentrated heat sources, a coupling method of nonlinear finite elements and linear boundary elements is proposed. The nonlinear finite elements (NFE) are applied in the vicinity of nuclear depository where thermo-mechanical stress is concentrated. The boundary elements are also used in infinite domain where linear behavior is expected. Using the similar method as for the problem in mechanical field, the coupled nonlinear finite element-boundary element (NFEBE) is developed. It is found that NFEBE method is more efficient than NFE which considers nonlinearity in the whole domain for the nuclear wastes depository that is expected to exhibit local nonlinearity behavior. The effect of coefficients of the rock mass such as Poisson's ratio, elastic modulus, thermal diffusivity and thermal expansion coefficient is investigated through the developed method. As a result, it is revealed that the displacements around tunnel are largely dependent on the thermal expansion coefficients.

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Transepidermal Water Loss, Stratum Corneum Hydration and Transmission Electron Microscope Observation on Acetone Damaged Canine Skin Barrier Model (아세톤에 의해 손상된 개 피부장벽 모델에서의 경표피수분소실도 및 각질층보습도 평가와 전자현미경적 관찰)

  • Oh, Won-Seok;Park, Seong-Jun;Oh, Tae-Ho
    • Journal of Veterinary Clinics
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    • v.27 no.2
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    • pp.142-146
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    • 2010
  • The purpose of this study is to establish experimental canine skin barrier disruption model in dog. The study was designed to investigate the predictive properties of acetone damage using as effect parameters transepidermal water loss (TEWL) and stratum corneum (SC) hydration. To compare the structures of SC intercellular lipids in normal and acetone damaged skin, TEM observations were performed. Six clinically normal, male Beagles without dermatological problems were chosen for this study. Acetone damage was performed at 48hrs after clipping. Efficacy measurements for TEWL and skin hydration were performed before ($t_1$) and after ($t_2$) damage in a temperature- and humidity-controlled room ($2{0\sim}22^{\circ}C$, 50-60%). TEWL and SC hydration values were decreased in the acetone damaged model compared with non damaged skin. In TEM observation of acetone damaged sample, the intercellular lipid lamellae exhibit abnormal and incomplete structure compared with those of normal skin. It seems that acetone damage would be one of canine skin epidermal barrier disruption model for the study of canine atopic dermatitis (AD) as well as dry skin in veterinary dermatology research.

언어적 측면에서 고찰한 도서관의 커뮤니케이션에 관한 연구 -의미전달을 중심으로-

  • 손연옥
    • Journal of Korean Library and Information Science Society
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    • v.8
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    • pp.69-96
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    • 1981
  • We all know that we can not keep a proper social life without language. Yet language is so much a part of our environment that we hardly realize it is there. The purpose of this study is to provide an understanding of the linguistical aspect of communication process in order to carry out a successful human relations in the operation of libraries. Human development rests upon man's capacity to digest large quantities of knowledge and it is language which allows facts to be communicated, stored, and disseminated. An attempt was made in this study to illustrate the elementary meaning-of-words aspect of communication. In order to share the most commonly agreed meanings in interpersonal communication, a careful study of semantic noises is important. In a constant struggle to meet client needs, staff and administrators, librarian must understand communication dialogues, their messages and be able to read all level of meanings. In order to perform a successful function of the librarian, to act as a link-man or communicator and to cope with its ever growing information, it is suggested that the deep understanding of the following linguistical aspect of communication elements is essential. 1. Characteristics of Language: (1) Words have different meanings to different people. (2) Words vary in the degree of abstraction. (3) Language is incomplete by its nature. (4) Language reflects not only the personality of the individual but also the culture of man's society. 2. Noises in transmitting meanings: (1) Mechanical or Technical noises. (2) Semantic Noises (3) Noises caused by the psychological factors a. attention b. perception, sensation, cognition and perceptual field. 3. Linguistic Stratum Languages differ considerably in vocabulary by the physical and cultural environment setting as well as situation of individual living. There are seven different language stratum which reflects different region, sex, age, profession, special social stratum, academic and tabooed words.

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Phospholipid Polymer, 2-Methacryloyloxyethyl Phosphorylcholine and Its Skin Barrier Function

  • LeeCho, Ae-Ri
    • Archives of Pharmacal Research
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    • v.27 no.11
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    • pp.1177-1182
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    • 2004
  • The effect of poly[2-methacryloyloxyethyl phosphorylcholine] (pMPC) on the skin permeation property was investigated by performing in vitro skin permeation study of a model drug, nicotinic acid (NA). Effect of pMPC polymer in donor solution on skin permeation rates was evaluated using side-by-side diffusion cells. Also, the structural alterations in the stratum corneum (SC), inter-lamellar bilayer (ILB) and dermis layers in pMPC-treated and -untreated skin sections were investigated with transmission electron microscopy (TEM). The permeation profile of NA without pMPC in donor solution showed biphasic mode: initial $1^{st} phase and 2^{nd}$ hydration phase. The sudden, more than 10-fold increase in flux from the initial steady state (43.5 $\mu g/cm^2$/hr) to the $2^{nd}$ hydration phase (457.3 $\mu g/cm^2$/hr) suggests the disruption of skin barrier function due to extensive hydration. The permeation profile of NA with 3% pMPC in the donor solution showed monophasic pattern: the steady state flux (10.9 $\mu g/cm^2$/hr) without abrupt increase of the flux. The degree of NA permeation rate decreased in a concentration-dependent manner of pMPC. TEM of skin equilibrated with water or 2% pMPC for 12 h showed that corneocytes are still cohesive and epidermis is tightly bound to dermis in 2% pMPC-treated skin, while wider separation between corneocytes and focal dilations in inter-cellular spaces were observed in water-treated skin. This result suggests that pMPC could protect the barrier property of the stratum corneum by preventing the disruption of ILB structure caused by extensive skin hydration during skin permeation study.

Structure and Histochemistry of Skin of Mud Loach, Misgurnus anguillicaudatus (Pisces, Cobitidae), from Korea (한국산 미꾸리 Misgumus anguillicaudatus (Pisces, Cobitidae) 피부 구조 및 조직화학적 특징)

  • Park, Jong-Young;Kim, Ik-Soo
    • Korean Journal of Ichthyology
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    • v.11 no.2
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    • pp.109-116
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    • 1999
  • The structure of skin of a mud loach Misgurnus anguillicaudatus was described in relation with their histochemical nature from four regions of the skin. The epidermis has a strongly thick layer of two glandular cells, consisting of a elongate mucous cell and club cell, and a thin layer of superficial layer. The secretion of the elongated mucous cell was acid mucopolysaccharides in nature but the club cell did not give any histochemical reaction. A well defined lymphatic system, comprising small lymphocytes was present in the stratum germinativum layer of the epidermis. A pit organ of a pear-shaped structure was present below the epithelial cells and lie directly on the basement membrane. The organ has blood vessels serving the sense organs of the epidermis. There was a definite area showing acid mucopolysaccharides in the stratum laxum layer of the dermis. Small scales are present deep in the dermis except the top of the head. A great number of blood capillaries were found just under basement membrane. These structural features of skin in M. anguillicaudatus seem to be closely related with cutaneous respiration using air.

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Effect of Ginseng Saponins on the Content of Cerebral Energy Metabolites in Carbon Monoxide-intoxicated Rats and Aged Rats (인삼 사포닌이 일산화탄소중독 및 노화과정에서 흰쥐의 뇌에너지 대사물 함량 변화에 미치는 영향)

  • Shin, Jeung-Hee;Choi, Hyun-Jin;Kang, Ji-Won;Park, Hea-Young;Yun, Jae-Soon
    • YAKHAK HOEJI
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    • v.36 no.3
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    • pp.278-284
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    • 1992
  • This study was performed to investigate the effects of ginseng saponins on the cerebral energy metabolite's contents influenced by carbon monoxide(CO) intoxication. Each experimental group was divided young ($5{\sim}8$ weeks) and aged ($43{\sim}52$ weeks) rats, and they were exposed at 5,000 ppm CO (72%HbCO) for 30 min. One of the other groups was pretreated with ginseng saponins for 5 days before CO intoxication. The contents of cerebral energy metabolites in cerebral cortex, stratum and hypothalamus were measured. In cerebral cortex of both young and aged rats, the levels of ATP and creatine phosphate were significantly decreased, while those of lactate were significantly increased. There was no difference between the levels of cerebral energy metabolites of young and aged rats. Pretreatment of ginseng saponins before CO intoxication lowered decrease of the levels of cerebral energy metabolites and ATP levels were significantly recovered. On the other hands, contents of lactate in stratum and hypothalamus of young rats were significantly increased and the levels of ATP and creatine phosphate in stratum and hypothalamus were completely recovered at 2 weeks after CO intoxication. The results suggest that ginseng saponins have an ameliorating action against disturbance of the cerebral energy metabolites by CO intoxication.

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Stratum Division Effect of Consolidation Settlement Formula Using Compression Index (압축지수를 이용한 압밀침하량 계산식의 압밀층 두께 분할효과)

  • Kim, Khi-Woong
    • Journal of the Korean Geosynthetics Society
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    • v.11 no.2
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    • pp.49-54
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    • 2012
  • The final consolidation settlement is important factor in soft ground improvement because of settlement management and completion time. The compression index, which is slope of primary consolidation curve, is commonly used for the calculation of final consolidation settlement in clay layer. The existing final consolidation settlement is calculated in total consolidation layer that is assumed as one layer. This paper describes analysis result of the acquired settlement, when the consolidation layer is divided as several layer. The consolidation settlement increased according to increase of the divided layer and then it is converged. This result was unrelated to surcharge load. The division effect of layer is very high when the surcharge load is less than the consolidation layer thickness. The division effect of layer is 1.2 to 1.4 in the general surcharge load, and this value can be apply as safety factor in the calculation of final consolidation settlement.

Relation Between the Growth Habitat and the Leaf Quality of Cultivated Mulberry Plants (뽕나무의 생육특성과 엽질과의 관계)

  • 김준호
    • Journal of Plant Biology
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    • v.17 no.3
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    • pp.118-126
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    • 1974
  • Mulberry plants cultivated in mid-Korea were studied on the growth habitat, canopy type, productive structure and vertical light intensity in relation to the quality of mulberry leaves for sericulture. The growth in length of new branch of summer cut mulberry in spring was vigorous on the uppermost of old shoot. Numbers of leaves on a branch were barely 4 leaves on lower than 20th branch from base, but those were 13 leaves on higher than 24th branch. Area of leaves completely expanded was broad on high branch, but narrow on low one. The form of canopy, the type of productive structure and the vertical light distribution depend upon varieties of cultivated mulberry plants were classified according to characteristic of each variety in two groups, respectively; globular and columnar form in canopy, broad leaves and narrow leaves types in productive structure, and seriously obstructured the light and fairly transmitted the light into lower leaf stratum invertical light distribution. Out of varieties of mulberry investigated, Suwon No. 4 and Rosang were belong to the former characters, but Illchiroe and Kaeryangsubun were to the latters. The values of leaf dry matter index and dry matter production produced by leaves were increased in direct proportion to the height of leaf stratum; the leaf dry matter index of the uppermost leaf was twice as much that of the lowest, and the dry matter production by the highest leaf was 17 times compared with that by the lowest leaf. It is assumed that the meagre leaves occurred in the lower leaf stratum of Suwon No. 4 and Rosang were caused to diminished the dry matter index and dry matter production in the under leaves of plant, which were affected by receiving the weak light.

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