Classification of the properties of porous materials

1986 ◽  
Vol 25 (12) ◽  
pp. 1006-1010
Author(s):  
P. A. Vityaz' ◽  
V. K. Sheleg ◽  
V. M. Kaptsevich ◽  
V. V. Savich ◽  
A. N. Sorokina
Keyword(s):  
Author(s):  
Zh.O. Petrova ◽  
V.M. Vyshnievskyi ◽  
Yu.P. Novikova ◽  
A.I. Petrov

The technology of drying colloidal capillary-porous materials to a final humidity of 6-8%, developed at the Institute of Technical Thermophysics of the NAS of Ukraine, allowed to obtain a brittle state, in which it is possible to grind this product to small particles. The most suitable for industrial grinding of the dried composite colloidal capillary-porous materials is the impact method, because when wiping and crushing the material has accumulated, stuck to the working surface. Powders are characterized by one pronounced maximum corresponding to the particle size of the powder of 0,16 mm. As the rotation speed of the shredder rotor changes, the particle size distribution of 0,16 mm increases by reducing the larger particles. The amount of powder thus obtained is directly proportional to the speed of rotation of the rotor. The study of the dispersion and classification of functional powders showed that all powders have the largest particle size of 0,16 mm. The maximum yield of this fraction is 70% and the lowest is 40%. The structural-mechanical characteristics of powders from composite colloidal capillary-porous materials were investigated for the first time.  Characteristics of different fractions were determined by such parameters as bulk density, vibration density, angle of natural slope, speed of material flow through the funnel and others. Studies to determine the structural and mechanical properties of functional powders have shown that they can be attributed to more bulk powders, as opposed to highly bound monopowders.  Creating compositions improves their structural and mechanical properties.


2007 ◽  
Vol 5 (2) ◽  
pp. 385-395 ◽  
Author(s):  
Borislav Zdravkov ◽  
Jiří Čermák ◽  
Martin Šefara ◽  
Josef Janků

AbstractClassification of pores is one of the basic requisites of comprehensive characterization of porous solids. There are various categorizations of pores described in the literature, but it is difficult to give a consistent global classification of porous substances including catalysts, adsorbents, oxides, carbons, zeolites, organic polymers, soils etc. The purpose of each of these classifications is to organize pores in classes by grouping them on the basis of their common characteristics like structure, size, accessibility, shape etc. In this study, a summary of the most used classifications of porous materials is done. Some common properties or behavior for individual classifications could be found, but many differences mainly in pore size are still subject of intensive discussions. Therefore, it is the purpose of this review to provide a general description of the concept and classification of pores in porous solids, to deal with complexity of the matter and to organise our knowledge in decision-making proccesses of pore characteristics determination.


1966 ◽  
Vol 24 ◽  
pp. 21-23
Author(s):  
Y. Fujita

We have investigated the spectrograms (dispersion: 8Å/mm) in the photographic infrared region fromλ7500 toλ9000 of some carbon stars obtained by the coudé spectrograph of the 74-inch reflector attached to the Okayama Astrophysical Observatory. The names of the stars investigated are listed in Table 1.


Author(s):  
Gerald Fine ◽  
Azorides R. Morales

For years the separation of carcinoma and sarcoma and the subclassification of sarcomas has been based on the appearance of the tumor cells and their microscopic growth pattern and information derived from certain histochemical and special stains. Although this method of study has produced good agreement among pathologists in the separation of carcinoma from sarcoma, it has given less uniform results in the subclassification of sarcomas. There remain examples of neoplasms of different histogenesis, the classification of which is questionable because of similar cytologic and growth patterns at the light microscopic level; i.e. amelanotic melanoma versus carcinoma and occasionally sarcoma, sarcomas with an epithelial pattern of growth simulating carcinoma, histologically similar mesenchymal tumors of different histogenesis (histiocytoma versus rhabdomyosarcoma, lytic osteogenic sarcoma versus rhabdomyosarcoma), and myxomatous mesenchymal tumors of diverse histogenesis (myxoid rhabdo and liposarcomas, cardiac myxoma, myxoid neurofibroma, etc.)


Author(s):  
Irving Dardick

With the extensive industrial use of asbestos in this century and the long latent period (20-50 years) between exposure and tumor presentation, the incidence of malignant mesothelioma is now increasing. Thus, surgical pathologists are more frequently faced with the dilemma of differentiating mesothelioma from metastatic adenocarcinoma and spindle-cell sarcoma involving serosal surfaces. Electron microscopy is amodality useful in clarifying this problem.In utilizing ultrastructural features in the diagnosis of mesothelioma, it is essential to appreciate that the classification of this tumor reflects a variety of morphologic forms of differing biologic behavior (Table 1). Furthermore, with the variable histology and degree of differentiation in mesotheliomas it might be expected that the ultrastructure of such tumors also reflects a range of cytological features. Such is the case.


Author(s):  
Paul DeCosta ◽  
Kyugon Cho ◽  
Stephen Shemlon ◽  
Heesung Jun ◽  
Stanley M. Dunn

Introduction: The analysis and interpretation of electron micrographs of cells and tissues, often requires the accurate extraction of structural networks, which either provide immediate 2D or 3D information, or from which the desired information can be inferred. The images of these structures contain lines and/or curves whose orientation, lengths, and intersections characterize the overall network.Some examples exist of studies that have been done in the analysis of networks of natural structures. In, Sebok and Roemer determine the complexity of nerve structures in an EM formed slide. Here the number of nodes that exist in the image describes how dense nerve fibers are in a particular region of the skin. Hildith proposes a network structural analysis algorithm for the automatic classification of chromosome spreads (type, relative size and orientation).


Author(s):  
Jacob S. Hanker ◽  
Dale N. Holdren ◽  
Kenneth L. Cohen ◽  
Beverly L. Giammara

Keratitis and conjunctivitis (infections of the cornea or conjunctiva) are ocular infections caused by various bacteria, fungi, viruses or parasites; bacteria, however, are usually prominent. Systemic conditions such as alcoholism, diabetes, debilitating disease, AIDS and immunosuppressive therapy can lead to increased susceptibility but trauma and contact lens use are very important factors. Gram-negative bacteria are most frequently cultured in these situations and Pseudomonas aeruginosa is most usually isolated from culture-positive ulcers of patients using contact lenses. Smears for staining can be obtained with a special swab or spatula and Gram staining frequently guides choice of a therapeutic rinse prior to the report of the culture results upon which specific antibiotic therapy is based. In some cases staining of the direct smear may be diagnostic in situations where the culture will not grow. In these cases different types of stains occasionally assist in guiding therapy.


Author(s):  
S. Arumugam ◽  
Sarasa Bharati Arumugam

Adenoaas of the pituitary are no longer classified based on their tinctorial affinity to dyes. With the advent of the newer methods of sophisticated technology, it is now possible to classify. These depending upon the type of hormone secreted based either on histochemical techniques or on ultrastructural characteristics. The latter provides an insight into the cytoplasmic organelle morphology which offers a delightful feast to the eye as well.This paper presents the ultrastructural characters of the pituitary adenoma as seen in Madras. 171 adenomas (124 males and 47 females) were seen during 1972-1989, classified at the light microscope level as 159 chromophobe, 2 basophilic, 4 eosinophilic and 6 mixed adenomas.Ultrastructural examination showed that the sparsely granular prolactin cell adenoma is the commonest adenoma to be encountered closely followed by the growth hormone cell adenoma, null cell adenoma, the mixed cell adenoma and others.


1997 ◽  
Vol 6 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Wayne O. Olsen ◽  
Terri L. Pratt ◽  
Christopher D. Bauch
Keyword(s):  

Multichannel ABR recordings for 30 otoneurologic patients were reviewed independently by three audiologists to assess interjudge consistency in determining absolute latencies and overall interpretation of ABR results. Four months later, the tracings were reviewed a second time to evaluate intrajudge consistency in interpretation of ABR waveforms. Interjudge agreement in marking latencies for waves I, III, and V within 0.2 ms was on the order of 90% or better. Intrajudge consistency was slightly higher. Only rarely did inter- or intrajudge differences in latency measurements exceed 0.3 ms. Agreement in overall interpretation of ABR results as "normal" or "abnormal" was unanimous for 90% of the patients. Across pairs of judges, the agreement for "normal" and "abnormal" classification of the ABR tracings was 97%. Intrajudge consistency for "normal" and "abnormal" categorization of the ABR results was 100% for one judge, 97% for the other two judges.


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