• Title/Summary/Keyword: laboratory and field tests

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Study on the Feeding Preferences of Luciola unmunsana Larvae (운문산반딧불이(Luciola unmunsana) 유충의 먹이선호도 연구)

  • Jeong, Moon-Sun;Kim, Jong-Man;Lim, Hyun-Jeong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.27 no.3
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    • pp.19-28
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    • 2024
  • The purpose of this study is to investigate the habitat of Luciola unmunsana to understand the status of land snails, which are the larvae prey, and to evaluate the effects of larval feeding preferences and prey size for the restoration of the L. unmunsana habitat as a basis for future restoration projects. The research methods included field surveys of the habitat and laboratory experiments on feeding preferences using three types of land snails (Allopeas clavulinum kyotoense, Euphaedusa fusaniana, Pupinella rufa) observed in the habitat. Field surveys of 13 L. unmunsana habitat sites revealed a total of 24 land snail species. The experimental results regarding the larvae prey were analyzed for statistical significance of feeding preferences using Chi-square tests and independent sample t-tests. Consequently, larvae showed the highest preference for A. c. kyotoense, with statistically significant differences in feeding preferences (p<0.05). Also, statistically significant differences were observed in the size between the land snails that were eaten as prey and those that were not eaten. This research can deepen the understanding of the feeding preferences of L. unmunsana larvae and provide practical guidelines for the effective conservation and restoration strategies of the firefly habitat.

Trial Installation and Performance Evaluation of Prefabricated Concrete Slab Track on Revenue Line (프리캐스트 콘크리트 슬래브궤도의 영업선 시험시공 및 성능평가)

  • Jang, Seung-Yup;Kang, Yun-Suk;Lee, Hu-Sam;Kim, Yu-Bong;Lee, Jong-Soo
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.840-845
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    • 2008
  • To develop our original technology of concrete slab track, being widely accepted for new track, prefabricated concrete slab track, or precast concrete slab track has been developed. They have two different types according to slab shape and its dimensions, connection of slabs and connecting structure onto substructure. After the system design and successful performance evaluation in the laboratory, the trial installation on revenue line has been carried out. This paper is presenting the result of the trial installation and the performance tests in field. The performance tests have been performed as visual inspection for cracks and damages, measurement of track alignment and elastic behavior of track under passing trains. The performance test results during last 2 years have shown that no remarkable damages and settlements were found, and track alignment and elastic track behavior both exhibits good status.

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Occurrence of Root Rot and Vascular Wilt Diseases in Roselle (Hibiscus sabdariffa L.) in Upper Egypt

  • Hassan, Naglaa;Shimizu, Masafumi;Hyakumachi, Mitsuro
    • Mycobiology
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    • v.42 no.1
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    • pp.66-72
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    • 2014
  • Roselle (Hibiscus sabdariffa L.) family Malvaceae is an important crop used in food, cosmetics and pharmaceutics industries. Roselle is cultivated mainly in Upper Egypt (Qena and Aswan governorates) producing 94% of total production. Root rot disease of roselle is one of the most important diseases that attack both seedlings and adult plants causing serious losses in crop productivity and quality. The main objective of the present study is to identify and characterize pathogens associated with root rot and wilt symptoms of roselle in Qena, Upper Egypt and evaluate their pathogenicity under greenhouse and field condition. Fusarium oxysporum, Macrophomina phaseolina, Fusarium solani, Fusarium equiseti and Fusarium semitectum were isolated from the natural root rot diseases in roselle. All isolated fungi were morphologically characterized and varied in their pathogenic potentialities. They could attack roselle plants causing damping-off and root rot/wilt diseases in different pathogenicity tests. The highest pathogenicity was caused by F. oxysporum and M. phaseolina followed by F. solani. The least pathogenic fungi were F. equiseti followed by F. semitectum. It obviously noted that Baladi roselle cultivar was more susceptible to infection with all tested fungi than Sobhia 17 under greenhouse and field conditions. This is the first report of fungal pathogens causing root rot and vascular wilt in roselle in Upper Egypt.

Estimation of Soil Volume Conversion Factors using Nondestructive Testing Methods (비파괴시험기법을 이용한 토량환산계수 산정 방법 제시)

  • Son, Thai An;Ryu, Hee-Hwan;Cho, Gye-Chun;Hong, Eun-Soo;Jin, Gyu-Nam
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.717-721
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    • 2010
  • Soil volume conversion factors are used for estimation of an excavated the soil volume which will be removed or added in levelling the ground surface of a construction site. An accurate evaluation method will help us reduce a construction cost and time consuming. In this study, we performed the laboratory tests, including grain size measurement, water content, specific gravity, porosity, density and XRD tests, to suggest reliable soil volume conversion factors and weathering indices in field using nondestructive methods. The weathering index and soil volume conversion factor L are obtained for different types of soils. At results, the CIW index is the best method measuring the weathering index and the factor L is relative to natural porosity, void ratio, density and dry density.

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Evaluation of Tunnel Face Stability with the Consideration of Seepage Forces (침투력을 고려한 토사터널 막장의 안정성 평가방법에 대한 고찰)

  • 남석우;이인모
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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    • pp.193-200
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    • 1999
  • Since Broms and Bennermark(1967) suggested the face stability criterion based on laboratory extrusion tests and field observations, the face stability of a tunnel driven in cohesive material has been studied by several authors. And recently, more general solution for the tunnel front is given by Leca and Panet(1988). They adopted a limit state design concept to evaluate the face stability of a shallow tunnel driven into cohesionless material and showed that the calculated upper bound solution represented the actual behavior reasonably well. In this study, two factors are simultaneously considered for assessing tunnel face stability: One is the effective stress acting on the tunnel front calculated by upper bound solution; and the other is the seepage force calculated by numerical analysis under the condition of steady state ground water flow. The model tests were performed to evaluate the seepage force acting on the tunnel front and these results were compared with results of numerical analysis. Consequently, the methodology to evaluate the stability of a tunnel face including limit analysis and seepage analysis is suggested under the condition of steady state ground water flow.

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A Study on the Grouting for the Underpinning of Open Caisson of Existing Bridge (기존 교량구조물의 유지관리를 위한 우물통 기초 보강주입에 관한 연구)

  • Chun, Byung-Sik;Yeoh, Yoo-Hyeon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.4 no.1
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    • pp.131-138
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    • 2000
  • In this study, physical and engineering properties of ordinary portland cement and microcement were investigated to verify reinforcing effect of underpinning of open caisson foundation by using microcement grouting. Laboratory injection tests such as infiltration and injection in case of seepage for the stream bed soil at ${\bigcirc}{\bigcirc}$ Great Bridge in Seoul were carried out. Field injection tests to reinforce open caisson foundation at ${\bigcirc}{\bigcirc}$ Great Bridge were performed and the ability of application by microcement grouting was evaluated. From the test results, physical and engineering properties of microcement are better than those of ordinary portland cement. Also, the ability of infiltration and solidity in case of seepage is better than that of ordinary portland cement. Therefore, it is concluded that microcement is an excellent material to reinforce open caisson foundation of the existing bridge structure under the water and can be used as underpinning material of general foundations.

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Higher-order assumed stress quadrilateral element for the Mindlin plate bending problem

  • Li, Tan;Qi, Zhaohui;Ma, Xu;Chen, Wanji
    • Structural Engineering and Mechanics
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    • v.54 no.3
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    • pp.393-417
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    • 2015
  • In this paper an 8-node quadrilateral assumed stress hybrid Mindlin plate element with $39{\beta}$ is presented. The formulation is based on complementary energy principle. The proposed element is free of shear locking and is capable of passing all the patch tests, especially the non-zero constant shear enhanced patch test. To accomplish this purpose, special attention is devoted to selecting boundary displacement interpolation and stress approximation in domain. The arbitrary order Timoshenko beam function is successfully used to derive the boundary displacement interpolation. According to the equilibrium equations, an appropriate stress approximation is rationally derived. Particularly, in order to improve element's accuracy, the assumed stress field is derived by employing $39{\beta}$ rather than conventional $21{\beta}$. The resulting element can be adopted to analyze both moderately thick and thin plates, and the convergence for the very thin case can be ensured theoretically. Excellent element performance is demonstrated by a wide of experimental evaluations.

Evaluation Technique of Ground Densification on Sand Deposit using SASW and Resonant Column Tests (표면파시험과 공진주시험을 이용한 사질토지반 개량평가 시스템의 개발)

  • 김동수;박형춘;김성인
    • Journal of the Korean Geotechnical Society
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    • v.15 no.1
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    • pp.41-52
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    • 1999
  • In order to assess the quality and depth of ground densification by compaction, SPT and/or CPT are performed before and after compaction. Both methods are intrusive and one point tests, require a substantial time to evaluate a large area, and their results are quite dependent on the operation technique and soil type. In this paper, the quality and extent of ground densification by compaction was evaluated by using in situ SASW test and laboratory resonant column (RC) test results. SASW test was used to determine the shear wave velocity profiles before and after compaction, and RC test was adopted to determine the correlation between the normalized shear wave velocity and the density of the site, which is almost uniquely independent of confinement. Testing and data reduction procedures of both tests were discussed, and a simplified evaluation procedure of ground densification was proposed. Finally, the feasibility of the proposed method was verified by performing field study at Inchon International Airport Project. Field densities determined by the proposed method matched well with those determined by sand cone tests.

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Assessment of RMR with the Monte Carlo Simulation and Stability Analysis of Rock Slopes (Monte Carlo Simulation 기법을 이용한 RMR의 역산 및 그에 의한 암반시면의 안정성 분석)

  • 최성웅;정소걸
    • Tunnel and Underground Space
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    • v.14 no.2
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    • pp.97-107
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    • 2004
  • Various kinds of rock mass properties, which can be obtained from laboratory tests as well as field tests, can be reasonably applied to the design of earth structures. An extrapolation technique can be used for this application and it generally guarantee its quality from a sufficient amount of test results because it is based on the RMR value in most cases. When the confident RMR can not be obtained because of the insufficient testing results, the Monte Carlo Simulation technique can be introduced fer deducing the proper RMR and this assessed RMR can be reused fur the major input parameters. Authors' proposed method can be verified from the comparison between the results of numerical analysis and the evidences of field site.

The Evaluation on In-Situ Adaptability of Mono-layer Landfill Final Cover System (단층형 매립지 최종복토시스템의 현장 적용성 평가)

  • Yu, Chan;Yun, Sung-Wook
    • Journal of The Korean Society of Agricultural Engineers
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    • v.48 no.5
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    • pp.73-80
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    • 2006
  • The mono-layer cover system is composed of soils only as a filling material and various plants are planted on the surface to control the water balance in the cover system. In this paper, the mono-layer cover system was considered as an alternative landfill final cover system and developed a model that could utilize industrial by-product (especially, coal ash & phosphogypsum) as additive filling materials. The mixture of granite soil, coal ash, and phosphogypsum was placed as a cover material in a box constructed with cement. Laboratory tests were carried out to investigate the environmental effect on the utilization of coal ash & phosphogypsum and to determine the mxing ratio of each materials. In the leaching test, all materials showed lower heavy metal concentration than the threshold values of regulation. The optimum mixing ratio of materials which was applied to field model test was determined to soil (4) : coal ash (1) : phosphogypsum (1) on the volume base. Field model tests were continued from February to July, 2004 in the soil box that was constructed with cement block. It was verified that coal ash and phospogypsum mixed with soil was to be safe environmentally and the water balance of mono-layer cover system was reasonable.