scholarly journals Soil Electrochemical and Physical Properties in Coffee Crops in the State of Paraná, Brazil

Author(s):  
Cezar Francisco Araujo-Junior ◽  
Vinicius Cesar Sambatti ◽  
João Henrique Vieira de Almeida Junior ◽  
Henrique Hiroki Yamada
2019 ◽  
Vol 808 ◽  
pp. 27-32
Author(s):  
Miloslav Novotný ◽  
Miloslav Novotný ◽  
Karel Šuhajda

The article deals with the methodology of the assessment of the state of the external facade of the outer cladding façade from the fiber cementitious boards in view of meeting the conditions of the technical legislation valid in the Czech Republic. On a particular case, the methodology of the procedure from the visual assessment of the facade facing plates to the requirements of their mechanical and physical properties is described. The object under consideration is a civic building in a climatically challenging location in the Beskydy foothills, whose facade is completely lined with fiber-cement boards. The assessment is based on the provisions of ČSN ISO 13822 (73 0038): Design principles for structures - Evaluation exists. construction and ČSN P 74 7251: 2015 Folded cladding, tiles and panel cladding - Requirements for casting accuracy, quality and appearance. For the assessment of mechanical and physical properties, the provisions of ČSN EN 12467 - Fiber-cement flat plates - Specimen specification and test method are used. Limit values ​​of individual parameters are taken into account in the technical sheets of the manufacturer of fiber-cement boards.


2012 ◽  
Vol 1373 ◽  
Author(s):  
J. May-Crespo ◽  
P. Quintana ◽  
J. J. Alvarado-Gil ◽  
B. A. Juárez de la Rosa ◽  
A. May-Pat ◽  
...  

ABSTRACTKnowledge of the mechanical and petrographic properties of limestone rocks is an important issue to different areas of science and engineering. Sedimentary limestone rock is one of the most abundant materials in the Peninsula of Yucatán used for decorative and building construction. This work studies the petrographic, mineralogical, and physical properties of three different types of limestone slabs of the state of Yucatán.


2005 ◽  
Vol 19 (16) ◽  
pp. 779-784
Author(s):  
YUAN-XING LI ◽  
QIN-MEI WANG ◽  
JING-BO XU

The mathematical and physical properties of the states which are generated by excitations on the coherent state of a harmonic oscillator in a finite-dimensional Hilbert space are studied. It is shown that the state exhibits squeezing in one of the quadratures of the field and sub-Poissonian photon statistics.


2018 ◽  
Vol 74 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Walter Steurer

More than 35 years and 11 000 publications after the discovery of quasicrystals by Dan Shechtman, quite a bit is known about their occurrence, formation, stability, structures and physical properties. It has also been discovered that quasiperiodic self-assembly is not restricted to intermetallics, but can take place in systems on the meso- and macroscales. However, there are some blank areas, even in the centre of the big picture. For instance, it has still not been fully clarified whether quasicrystals are just entropy-stabilized high-temperature phases or whether they can be thermodynamically stable at 0 K as well. More studies are needed for developing a generally accepted model of quasicrystal growth. The state of the art of quasicrystal research is briefly reviewed and the main as-yet unanswered questions are addressed, as well as the experimental limitations to finding answers to them. The focus of this discussion is on quasicrystal structure analysis as well as on quasicrystal stability and growth mechanisms.


1819 ◽  
Vol 109 ◽  
pp. 283-299 ◽  

My Dear Sir, The substance called Tabasheer, has been long used as a medicine in Turkey, Syria, Arabia, and Hindostan. It was first made generally known in Europe by Dr. Patrick Russell, who published in the Philosophical Transactions, for 1790, a very interesting account of its natural history, and of the process by which it seems to be formed. From his en­quiries it appears, that this substance is found in the cavities of the bamboo, the Arundo bambos of Linnæus; and that it exists originally in the state of a transparent fluid, which ac­quires by degrees the consistency of a mucilage resembling honey, and is afterwards converted by gradual induration into a white solid, called Tabasheer. From the analysis of Mr. Macie (now Mr. Smithson), it appeared to be “perfectly identical with common siliceous earth.” The celebrated traveller M. Humboldt, discovered the same substance in the bamboos which grow to the west of Pinchincha, in South America, and a portion of what he brought to Europe in 1804, was analyzed by Fourcroy and Vauquelin, who found it to consist of 70 parts of silex, and 30 of potash and lime.


Tabasheer is a substance found in the cavities of the bamboo, existing originally in the state of a transparent fluid, but gradually indurating into a solid of different degrees of hardness: it consists of 70 silica, + 30 potash and lime. One variety has a milky transparency, transmitting a yellowish, and reflecting a bluish light; another is translucent, and a third opake: the two first varieties become transparent, and evolve air when immersed in water: the third evolves air also, but remains opake. If the first varieties be only slightly wetted they become quite opake. The property of acquiring transparency by the evolution of air from, and the absorption of water by its pores, belongs also to the hydrophanous opal; but the faculty of becoming opake by a small quantity, and transparent by a larger, of water, shows a singularity of structure in tabasheer. As the tabasheer disengages more air than hydrophane, its pores must be more numerous; and therefore the transmission of light, so as to form a perfect image, indicates either a very feeble refractive power or some peculiarity in the construction of its pores. To determine this, Dr. Brewster formed a prism of tabasheer with an angle of 34° 15', and upon measuring its refractive power found it very low, though various in different specimens, the index of refraction varying from 1·11 to 1·18, that of water being 1·33, of flint-glass 1·60, of sulphur 2·11, of phosphorus 2·22, and of the diamond 2·47. So that tabasheer has a lower refractive power than any other solid or liquid, and holds an intermediate place between water and the gases. Dr. Brewster then gives a formula for computing the absolute refractive power of bodies, and a table of results, from which it appears that, in this respect, the refractive power of tabasheer is so low as to be separated by a considerable interval from all other bodies. The author next proceeds to detail a variety of experiments upon the absorbent powers of the different kinds of tabasheer, in respect to several liquids, and the corresponding effects upon its optical properties and specific gravity, and concludes with observations on the cause of the paradox exhibited by the transparent tabasheer, in becoming opake by absorbing a small quantity of water, and transparent when the quantity is increased.


2019 ◽  
Vol 3 (1) ◽  
pp. 50
Author(s):  
Zakky Zakky ◽  
Bayu Satyawira ◽  
Samsol Samsol

Mud is one of the things that is very supportive in drilling operations, the design of the mud can affect the effectiveness of drilling work, the costs to be incurred, up to when the well is in production. Of course what is expected from a mud usage is low expenditure and drilling with optimal results. Drilling mud plays a very important role in a drilling operation. Drilling that can run quickly, safely and economically is greatly influenced by the conditions and sludge system used. The condition referred to here is how the properties or rheology of the mud. Whereas the mud system referred to here is a certain type of mud that must be used with regard to the state of the formation and borehole. Muddy KCl-POLYMER is a non-dispersed mud, where the hydration and dispersion process of the shale formation drilled must be maintained or maintained as much as possible. There are several ways to achieve this, the most common of which is to limit the amount of water that reacts with the shale, by covering the cutting produced by the shale with the polymer as soon as possible to prevent further reactions with water. In this study, we will analyze the use and physical properties of drilling mud using KCl-Polymer sludge which is carried out in the Trisakti University Laboratory of Petroleum Drilling and Production.


Rodriguésia ◽  
2020 ◽  
Vol 71 ◽  
Author(s):  
Marcelo Mendes Braga Júnior ◽  
Thayrine Silva Matos ◽  
Gabriele Melo de Andrade ◽  
Pâmela da Silva Ferreira ◽  
Marta César Freire Silva ◽  
...  

Abstract The aim of this study was to identify, anatomically characterize, and determine some of the physical properties of wood species that are used for boat production in the southeast region of the state of Pará in Brazil. The samples were collected during visits to shipyards in the region, then it was identified at the specie level and technologically characterized. Eight species belonging to four distinct botanical families were identified. All identified species had presented some type of deposition in its vessels and 87% of them had had medium density (0.40 to 0.75 g.cm-3). The species with higher frequency of occurrence and that had more parts used for boat production were Caryocar villosum and Apuleia leiocarpa. It was observed two different group arrangements of species, “piquiá” (Caryocar villosum and Alexa grandiflora) and “tatajuba” (Bagassa guianensis and Enterolobium schomburgkii). It was also identified the illegal commercialization of “castanheira’s” wood (Bertholletia excelsa). The results can indicate anatomical and physical similarities in woods used in boat production and can contribute as a component of a database in wood anatomy of specie used for boat production in the Amazon region, besides to subside practices that contribute to an effective supervision of the logging market in the region.


2012 ◽  
Vol 2 (3) ◽  
pp. 76-79
Author(s):  
O. N KOTKOVA

In most industrial buildings damaged in the building structures are due to violations of the properties of the subsoil. Changes in the physical properties of the soil leads to deformation aboveground structures, the state of which the examination can be viewed as a limited ability to work or even crash.


2015 ◽  
Vol 396 (6-7) ◽  
pp. 597-609 ◽  
Author(s):  
Ana C. Carreira ◽  
Ana E. Ventura ◽  
Ana R.P. Varela ◽  
Liana C. Silva

Abstract From the most simple sphingoid bases to their complex glycosylated derivatives, several sphingolipid species were shown to have a role in fundamental cellular events and/or disease. Increasing evidence places lipid-lipid interactions and membrane structural alterations as central mechanisms underlying the action of these lipids. Understanding how these molecules exert their biological roles by studying their impact in the physical properties and organization of membranes is currently one of the main challenges in sphingolipid research. Herein, we review the progress in the state-of-the-art on the biophysical properties of sphingolipid-containing membranes, focusing on sphingosine, ceramides, and glycosphingolipids.


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