检索结果-南通市图书馆

Transient infiltration tests in pyroclastic soils with double porosity

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2023年第11期20卷 3327-3342页

作者： Ciro SEPE Domenico CALCATERRA Emilia DAMIANO Diego DI MARTIRE Roberto GRECO Lucia PAPPALARDO Massimo RAMONDINI Enza VITALE Giacomo RUSSO Department of Civil and Mechanical Engineering University of Cassino and Southern LazioCassino 03043Italy Department of Earth Science Environment and ResourcesUniversity of Napoli Federico IINapoli 80126Italy Dipartimento di Ingegneria Universitàdegli Studi della Campania“L.Vanvitelli”Aversa 81031Italy Istituto Nazionale di Geofisica e Vulcanologia Sezione di Napoli-Osservatorio VesuvianoNapoli 80124Italy Department of Civil and Environmental Engineering University of Napoli Federico IINapoli 80125Italy

Fallout volcanic deposits of SommaVesuvius(Campania,southern Italy),characterized by the presence of layers with contrasting textural and hydraulic properties,are frequently affected by shallow landslides during rainwater *** soils of the stratigraphic sequence present intraparticle pores,originated by the gases escaped during magma decompression in the volcanic conduit,thus are characterized by double porosity(i.e.,intraparticle and interparticle pores),which is expected to affect their hydraulic behaviour,and to play a key role in rainwater infiltration through layered *** understand the effect of double porosity on the hydraulic behaviour of the involved soils,controlled experiments have been carried out in an infiltration *** experimental apparatus is provided with newly designed non-invasive Time Domain Reflectometry(TDR)probes,not buried in the investigated soil layers so as to minimize disturbance to the flow,allowing water content measurement during vertical flow ***,transient flow experiments are carried out through reconstituted specimens of black scoriae and grey pumices,both loose pyroclastic granular soils from fallout deposits of Somma-Vesuvius,featuring double porosity with different pore size distributions,that were estimated by x-ray tomography and Mercury Intrusion *** experimental results highlight the effects of the double porosity and clearly indicate the different behaviour of the two soils during wetting and drying processes,mainly related to the different dimensions of intraparticle pores.

关键词： Double porosity soil Non-invasive TDR probes Vesiculated soil particles Pyroclastic soils x-ray tomography Mercury intrusion porosimetry

Modeling of Crack Development Associated with Proppant Hydraulic Fracturing in a Clay-Carbonate Oil Deposit

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2023年第2期19卷 273-284页

作者： Sergey Galkin Ian Savitckii Denis Shustov Artyom Kukhtinskii Boris Osovetsky Alexander Votinov Perm National Research Polytechnic University PermRussian Perm State National Research University PermRussian PermNIPIneft Branch of LUKOIL-Engineering LLC PermRussian

Survey and novel research data are used in the present study to classify/identify the lithological type of Verey age reservoirs’*** is shown how the use of x-ray tomography can clarify the degree of heterogeneity,porosity and permeability of these *** data are then used to elaborate a model of hydraulic *** resulting software can take into account the properties of proppant and breakdown fluid,thermal reservoir conditions,oil properties,well design data and even the filtration and elastic-mechanical properties of the *** of hydraulic fracturing crack formation are carried out and the results are compared with the data on hydraulic fracturing crack at standard *** differences in crack formation in standard and lithotype models are *** is shown that the average width of the crack development for the lithotype model is 2.3 times higher than that for the standard ***,the coverage of crack development in height for the lithotype model is almost 2 times less than that for the standard *** estimated fracture half-length for the lithotype model is 13.3%less than that of for the standard model.A higher dimensionless fracture conductivity is also obtained for the lithotype *** is concluded that the proposed approach can increase the reliability of hydraulic fracturing crack models.

关键词： Proppant hydraulic fracturing x-ray tomography porosity permeability fractured reservoir well logging carbonate deposits

Fatigue of asphalt binder,mastic and mixture at low temperature

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2012年第2期6卷 166-175页

作者： Dong WANG Linbing WANG Guoqing ZHOU Virginia Tech Transportation Institute Blacksburg VA 24061USA The Via Department of Civil and Environmental Engineering Virginia Polytechnic Institute and State UniversityBlacksburg VA 24061USA Guangxi Key Laboratory for Spatial Information Guilin University of TechnologyGuilin 541004China

The fatigue damage is one of the most common distresses observed on the asphalt concrete *** thoroughly understand the fatigue of asphalt concrete,the behaviors of the major components of asphalt concrete under cyclic loading are investigated respectively in this study.A new experiment method is developed to evaluate the performances of asphalt binder,mastic and fine aggregates mixture under cyclic tensile *** fatigue test results of asphalt binder show that the fatigue performance of asphalt binder is closely related with loading magnitude,temperature and loading *** specimens with different filler content are tested and the results indicate that mastic specimens with 30%filler content show better fatigue resistance and higher permanent *** micro-structure analysis of mastic and mixture indicates that the fatigue resistance is closely related with the air void content of specimen.3D digital specimens are developed to model the fatigue of the asphalt binder,mastic and mixture specimens based on the finite element method(FEM).Fatigue damage of asphalt concrete is simplified by a damage *** proper selection of damage parameters,the simulation results agree well with laboratory test results and can be used as a basis for future fatigue research.

关键词： fatigue asphalt mixture asphalt binder mastic finite element method(FEM) x-ray tomography

Development of 3D crystallographic orientation measurement for grain deformation analysis in aluminum alloy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2014年第7期24卷 2094-2101页

作者： M.KOBAYASHI H.TODA D.J.LECLERE T.KAMIKO K.UESUGI A.TAKEUCHI Y.SUZUKI Department of Mechanical Engineering Toyohashi University of Technology Department of Mechanical Engineering Kyushu University Japan Synchrotron Radiation Research Institute

Development of inhomogeneous deformation is an interest matter in material engineering. Synchrotron radiation tomography provides 3D distribution map of local strain in polycrystalline aluminum alloy by tracking microstructural features. To perform further deep analysis on development of inhomogeneous deformation, crystallographic grain orientation is necessary. Three-dimensional x-ray diffraction technique was developed. A new crystallographic orientation measurement method was described in 3D space, utilizing grain boundary tracking （GBT） information.

关键词： synchrotron radiation x-ray tomography x-ray diffraction plastic deformation crystallographic orientation

Micropores in G20Mn5N cast steel and their influence on stress distribution

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Southeast University(English Edition) 2024年第3期40卷 286-294页

作者： Yan Huadong Jin Hui School of Civil Engineering Southeast UniversityNanjing 211189China Jiangsu Key Laboratory of Engineering Mechanics Southeast UniversityNanjing 211189China

To accurately analyze the impact of casting pores in steel,high-resolution 3D x-ray tomography technology was used to gather detailed statistical information about *** micropores were classified as gas,shrinkage,and gas-shrinkage pores depending on their formation origin and *** tendencies and affinity parameters were defined to characterize the spatial correlations among these three types of *** 3D data from x-ray tomography scans were then integrated into finite element analysis(FEA)software to predict how micropore shape,size,and distribution influence stress distribution within the *** results show that certain inflection points with small local radii within the cast pores are major contributors to stress ***,cast pores cannot be simply modeled as ideal spherical *** sphericity and volume of pores have a significant impact on the stress concentration of the ***,lower sphericity and larger pore volumes result in higher stress ***,the internal pores of steel castings exhibit specific global distribution *** located on the surface of the specimen lead to significantly higher stress concentrations compared to those located inside the specimen.

关键词： cast steel micropores x-ray tomography 3D reconstruction finite element analysis

The Potential of Quartzitic Veins in SW Cameroon for High-Purity Quartz

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Geosciences 2022年第4期13卷 281-302页

作者： Ngambu Aloysius Afahnwie Arnold Chi Kedia Cheo Emmanuel Suh Cyrille Sigue Elisha Mutum Shemang Department of Geology Mining and Environmental Science Faculty of Science University of Bamenda Bamenda Cameroon Economic Geology Unit Department of Geology University of Buea Buea Cameroon Department of Earth and Environmental Sciences Botswana International University of Science and Technology Palapye Botswana

High-purity quartz (HPQ), the prime source of silica, is increasingly considered a strategic mineral in the world market because it is the raw material for special applications in high-tech industries owing to its unique physical and chemical properties. The expected growth in demand for HPQ implies that more sources have to be found. This is the primary motivation for this study which targets the Supe area, SW Region of Cameroon. The structural occurrences of quartz veins were mapped and samples collected. The chemical nature and textural features of these samples were subsequently analyzed by x-ray tomography, scanning electron microscopy (SEM), and electron microprobe analysis (EMPA). Three deformation events, D1 - D3 are recorded. D1 is marked by the development of the strong S1 foliation defined by the gneissic layering and schistosity. D2 is a NE-SW ductile to brittle sinistral shear that controlled the formation of tension gashes that served as subsequent pathways for quartz-rich hydrothermal fluids to circulate and eventually precipitate quartz. The presence of rutile, tourmaline, and mica inclusions in the Supe veins affects the purity of the quartz. However, quartz can be treated to improve its quality. Taking into consideration the nine determinant trace elements used to classify HPQ, three (Li, P, and B) are below detection limits, Al concentrations are within the HPQ, quartz market standard, and average natural abundance;Ti values are high above all three standards in all except one sample, while Na, Ca, K, and Fe values fluctuate, thus classifying one of the samples as high purity quartz and the others as low purity quartz. These veins define tension gashes which usually occur in an echelon arrangement covering a large surface area, suggesting that more of such veins probably exist in the Supe area. Consequently, the quality and potential quantity of HPQ veins in this area suggest a high potential

关键词： Quartz Veins High Purity Quartz x-ray tomography Rutile Tourmaline

Experimental study on meso-damage cracking characteristics of RSA by CT test

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Experimental study on meso-damage cracking characteristics o...

乳腺密度类型与年龄、生育因素及乳腺癌的相关性

中国科学院地质与地球物理研究所2015年度（第15届）学术年会

作者： Y.Wang x.Li Y.F.Wu C.Lin B.Zhang Key Laboratory of Shale Gas and Geoengineering Institute of Geology and GeophysicsChinese Academy of Sciences

This paper investigates the meso-damage mechanism and the cracking characteristics of rock and soil aggregate(RSA)by x-ray computed tomography(CT)under uniaxial compressive *** RSA specimens(50 mm diameter and 100 mm height)with rock percentage 40%were produced to perform a series of uniaxial compressive strength *** damage cracking characteristic is identified by the mean CT value,and also the meso-damage propagation law is analyzed based on the damage factor defined by the CT *** the test results,the variation of CT value for region of interest is different at the same stress level,the mean CT value for the RSA specimen,and rock block inclusions,and their adjacent soil regions decrease with the increasing stress *** is more sensitive for block inclusions than soil ***,the meso-damage evolution equation and constitutive equation for RSA are *** estimated result is in agreement with the measured ***,based on the image threshold segmentation method,length,area,and mean width of cracks obey to power function *** statistical characteristics are closely related to the rock block’s distribution and *** results confirm that the elastic mismatch of RSA is the primary reason resulting in cracking under loading,damage characteristics of RSA is progressive,cracking begins from rock-soil interfaces,and then propagate into soil matrix.

关键词： Rock and soil aggregate(RSA) x-ray tomography CT value Meso-damage mechanism Cracking evolution

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

乳腺密度类型与年龄、生育因素及乳腺癌的相关性