• Title/Summary/Keyword: Paris

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Finite Element Simulation of Fatigue Crack Growth: Determination of Exponent m in Paris Law (피로균열성장의 유한요소 시뮬레이션: Paris 법칙의 지수 m의 결정)

  • Chu, Seok-Jae;Liu, Cong-Hao
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.7
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    • pp.713-721
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    • 2012
  • The finite element simulations of fatigue crack growth are carried out. Using only the mechanical properties usually obtained from the tensile test as input data, we attempted to predict the fatigue crack growth behavior. The critical crack opening displacement is determined by monitoring the change in displacements at the node close to the crack tip. Crack growth is simulated by debonding the crack tip node. The exponent in the Paris law was determined and compared to the published exponent. Plotting with respect to the effective stress intensity factor range yielded more consistent results.

Expression of transforming growth factor-1 in bone regeneration after the implantation of particulate dentin and plaster of Paris

  • Huh, Young-Chul;Kim, Su-Gwan;Kim, Jeong-Sun;Yoon, Jung-Hoon;Kim, Do-Kyung
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.32 no.1
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    • pp.27-35
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    • 2006
  • Purpose: This study was performed to investigate the expression of the transforming growth factor (TGF)-1, in a rat calvarium defect model using particulate dentin and/or plaster of Paris, and correlate the bone regeneration process with the histologic events. Materials and Methods: Thirty-two Sprague-Dawley rats were divided into 4 groups of 8 animals each. A 1.0 cm-sized calvarial defects were made and the defect was filled with different graft materials as follows : Group A, the defects were filled with a mixture of particulate dentin and plaster of Paris with a 2:1 ratio; Group B, the defects were filled with plaster of Paris only; Group C, defects were filled with particulate dentin only; Group D, untreated control group. The animals were sacrificed by 1, 2, 4, 8 weeks after implantation. Excised wound tissues were processed for histology, immunohistochemistry and RT-PCR for the analysis of TGF-1 expression. Results: Gene expression of TGF-1 was detected for all experimental groups. The highest gene expression was observed in the specimen taken at the first week after implantation in Group A. According to the histologic and immunohistochemical studies, TGF-1 positive osteoblast-like cells were found in the early stage of healing after the implantation of particulate dentin and plaster of Paris. Conclusion: These findings suggest that TGF-1 may be related to new bone formation at the early healing process after the implantation of particulate dentin and plaster of Paris.

Distribution and phytomedicinal aspects of Paris polyphylla Smith from the Eastern Himalayan Region: A review

  • Sharma, Angkita;Kalita, Pallabi;Tag, Hui
    • CELLMED
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    • v.5 no.3
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    • pp.15.1-15.12
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    • 2015
  • Comparative studies have established that the North-Eastern (NE) region of India which is a part of the Eastern Himalayan region is affluent in both traditional knowledge based phytomedicine and biodiversity. About 1953 ethno-medicinal plants are detailed from the NE region of India out of which 1400 species are employed both as food and ethnopharmacological resources. Nearly 70% of species diversity has been reported from the two Indian biodiversity hotspots-The Western Ghats and the Eastern Himalayas and these hotspots are protected by tribal communities and their ancient traditional knowledge system. Paris polyphylla Smith belongs to the family Melanthiaceae and is a traditional medicinal herb which is known to cure some major ailments such as different types of Cancer, Alzheimer's disease, abnormal uterine bleeding, leishmaniasis etc. The major phytoconstituents are dioscin, polyphyllin D, and balanitin 7. Phylogeny of Paris was inferred from nuclear ITS and plastid psbA-trnH and trnL-trnF DNA sequence data. Results indicated that Paris is monophyletic in all analyses. Rhizoma Paridis, which is the dried rhizome of Paris polyphylla is mainly used in Traditional Chinese Medicine and its mode of action is known for only a few cancer cell lines. The current review determines to sketch an extensive picture of the potency, diversity, distribution and efficacy of Paris polyphylla from the Eastern Himalayan region and the future validation of its phytotherapeutical and molecular attributes by recognizing the Intellectual Property Rights of the Traditional Knowledge holders.

Calibration of frequency propagation channel sounder based on five-port reflectometer

  • Yem Van;Braga Judson;Huyart B;Begaud X;de Sousa F.R;Huyen Nguyen Bich
    • Proceedings of the IEEK Conference
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    • summer
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    • pp.23-26
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    • 2004
  • Five-port reflectometer which consists of a ring with 5 arms (two inputs, three outputs) and three RF power detectors has been used as a vector network analyser, a demodulator in the homodyne receiver as well as in Phase Looked Loop (PLL) and so on. Calibration of five-port reflectometer is an important task. In this paper, we present a calibration method of five-port for a propagation channel sounder. The method is based on measurement of the phase differences between the three voltages at the five-port's outputs in order to determine the ratio of two input incident waves. The frequency channel sounder based on five-port is calibrated for each frequency from 2.2 GHz to 2.6 GHz with 1 MHz step. This method can also determine the absolute delays of each propagation path in the propagation channel. The calibration method is validated using measurement data.

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A Semiological Interpretation of the Koreaness in Paris Park, Seoul (파리공원에 반영된 한국성의 기호학적 해석 -예름슬레우 모델을 중심으로-)

  • 김동찬;유재설;김성준
    • Journal of the Korean Institute of Landscape Architecture
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    • v.28 no.3
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    • pp.53-60
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    • 2000
  • Although built-environment has not only function but also socio-cultural meanings, the latter is neglected in the modernism. People don't have the identity of their place because they can't communicate with environment. Therefore, expressing the socio-curtural meanings in landscape is one of main issues after the modern era. The meanings of phenomena can be analyzed by the Semiology based on Structurism, the methodology which has been developed in Linguistics and Anthropology since 1900's. The purpose of this study is to adapt Helmslev's model that can effectively explain the meanings of built-environment and interpret the Koreaness, one of important meanings in contemporary urban park, Paris park. The following methods are used for achieving the purpose. 1. Adaptation of the Helmslev's model for interpreting the urban park. 2. Interpretation of the Paris park. 3. Making the types of interpretion of Paris park. The results are as followings: 1. Helmslev's model can explain the content and expression of the urban park in denotation and connotation. 2. Th socio-cultural meanings of Paris park are the relationship of France, Yan and Yin theory, philosophy of Samjae, king's authority. And they are expressed in the pattern of paving, the shape of mounds, fountain, and pond, a picture of the wall, colours of lightings and columns, and a mark of bollards.

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A novel triaxial testing device for unsaturated soils with measurement of suction and volumetric strains

  • Qian-Feng Gao;Mohamad Jrad;Mahdia Hattab;Said Taibi;Jean M. Fleureau
    • Geomechanics and Engineering
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    • v.37 no.2
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    • pp.109-122
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    • 2024
  • Standard triaxial cells are commonly used to measure the mechanical behavior of saturated soils. However, this type of standard system is difficult to use for unsaturated soil specimens since it cannot measure the changes in the pore-air volume and pressure. This paper proposes to extend the measurement possibilities of the standard triaxial testing device in a simple way and to adapt it to partially saturated soils. The system is supplied by two hygrometers installed at each end of the cylindrical unsaturated specimen to measure local relative humidity, which allows the derivation of suction. The volumetric strain of the specimen is calculated by analyzing digital photos captured from the outside of the transparent cell wall. Specimens made of kaolin clay, having different hydraulic properties, were tested to verify the reliability of the measurements, and thus, the relevance of the proposed techniques to study the mechanical behavior of unsaturated soils.

The Effect of Aloe, Gelfoam, Plaster on Bone Formation in Applying to the Bone Defect (Aloe, Gelfoam, Plaster가 골결손부의 신생골 형성에 미치는 영향에 관한 실험적 연구)

  • Choi Eui-Hwan;Kim Su-Gwan
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.29 no.2
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    • pp.493-505
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    • 1999
  • Purpose: This study was to evaluate the effects of Aloe. Gelfoam. and Plaster of Paris on bone healing. Materials and Methods: Four experimental defects were created for placement of the three materials in the right femur of dogs. One defect served as an empty control site. The evaluation was performed at 1-. 6-. and 12-weeks by light microscopy and radiographs. Results: Radiographic and histologic examinations showed new bone formation in the presence of Aloe, Gelfoam. and Plaster of Paris and similar bone healing reactions. Conclusion: On the basis of these findings, it was concluded that Aloe, Gelfoam. and Plaster of Paris may be adequate agents for use in bone procurement.

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WTO, an ontology for wheat traits and phenotypes in scientific publications

  • Nedellec, Claire;Ibanescu, Liliana;Bossy, Robert;Sourdille, Pierre
    • Genomics & Informatics
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    • v.18 no.2
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    • pp.14.1-14.11
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    • 2020
  • Phenotyping is a major issue for wheat agriculture to meet the challenges of adaptation of wheat varieties to climate change and chemical input reduction in crop. The need to improve the reuse of observations and experimental data has led to the creation of reference ontologies to standardize descriptions of phenotypes and to facilitate their comparison. The scientific literature is largely under-exploited, although extremely rich in phenotype descriptions associated with cultivars and genetic information. In this paper we propose the Wheat Trait Ontology (WTO) that is suitable for the extraction and management of scientific information from scientific papers, and its combination with data from genomic and experimental databases. We describe the principles of WTO construction and show examples of WTO use for the extraction and management of phenotype descriptions obtained from scientific documents.

Experimental and numerical analysis of corrosion-induced cover cracking in reinforced concrete sample

  • Richard, Benjamin;Quiertant, Marc;Bouteiller, Veronique;Delaplace, Arnaud;Adelaide, Lucas;Ragueneau, Frederic;Cremona, Christian
    • Computers and Concrete
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    • v.18 no.3
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    • pp.421-439
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    • 2016
  • Corrosion of embedded reinforcing bars is recognized as being the major cause of deterioration of reinforced concrete structures. With regard to maintenance strategies of concrete nuclear structures, the monitoring of cracking remains of primary importance. Recently, authors have developed a post-treatment technique to extract crack features from continuous computations. In this paper, such technique is applied to carry out a numerical analysis of an accelerated corrosion test. Obtained results allow highlighting specific propagation and failure mechanisms that characterize corrosion-induced cracking.