摘要:

SUMMARYThe permeability coefficient of non‐woven geotextiles used for soil stabilization, erosion control and earth reinforcement is predicted from a proposed analytical method. A mathematical model is used to depict both fabric's void and soil particles histograms and related them to forecast eventual clogging level. Experimental data indicated a relationship between water permeability and fibre density of a fabric. Lastly a proposed method is presented for the prediction of the filtration performance of multi‐layer or composite fabr

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1981.tb01202.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYPicture processing using generalized instrumentation with specially developed software, and image analysis by means of a Quantimet 720 image analyser with a linear correlator, were employed in the study of rock textures. The boundaries of all individual grains from a portion of a thin section of a rock were distinguished and hand‐drafted for digitization and analysis. From the grey level image of boundaries of the profiles of the grains, obtained by hexagonal scanning of line drawings, binary images were produced for each phase and used for textural measurements. Ink drawings extracted from the boundary pattern were also used for the image analyser experiments.In picture processing experiments, programmed structuring elements of different shapes and two‐dimensional autocorrelation functions were used to characterize morphology and spatial distribution of the different phases. Transformations of binary images were programmed at the bit level to reduce storage requirements and computing time. In Quantimet 720 experiments, linear erosion and histogram of sizes were used for computing the mean dimensions of the grains. Periodical arrangements were studied by means of the covariance function.This contribution uses simple texture measures derived from mathematical morphology and picture processing methods, in order to assess the feasibility of two different technical approaches in the analysis of the same material. The extraction of image information from the material analysed, which was not attempted before, is cumbersome and technically complex. This difficulty is partly responsible of why little is known on the quantitative characterization of metamorphic textures from thin secti

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1981.tb01203.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYThis study discusses the use of automatic image analysis equipment in quantifying the structural changes during growth of rat pulmonary parenchyma. At birth the latter consists of primary septa delineating a coarse structure of alveolar sacs which are then subdivided into alveoli by outgrowth of secondary septa from day 4 onwards. This process is followed by internal restructuring of the septa in the third week which further increases the surface area by formation of small irregularities.A partial quantification of these processes was obtained by measuring the full set of parameters available with the Quantimet 720 using light microscopy on rat lung sections at the ages of 4, 10 and 21 days. This yielded basic data, e.g. volume and surface densities of air space and tissue. Using closure and opening as preprocessing operations made it possible to split up such parameters into contributions from different ranges of detail resolution.The mass of eighty‐four variables obtained could be reduced to six independent factors by Factor Analysis techniques. Interpretation through their correlation with the original variables yielded septal surface, septal volume, minor and major axes of the large air spaces, and surface detail as important structural descriptors explaining 70% of total variance. The remainder is attributed to between‐field variati

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1981.tb01204.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

ISSN:0022-2720    

DOI:10.1111/j.1365-2818.1981.tb01205.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY