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1998
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tom Vol. 24, no. 1
17-26
PL
Niszczenie kamiennych elementów budowlanych uzależnione jest od wielu czynników, zarówno naturalnych jak i antropogenicznych. Wśród tych ostatnich za jeden z najistotniejszych uznaje się wpływ zanieczyszczeń powietrza. Powodują one wzrost obecności w skałach produktów ich chemicznej korozji- m.in.soli rozpuszczalnych w wodzie. Podjęto badania próbek skał: piaskowców, wapieni i granitoidów, pochodzących z czterech budowli zabytkowych zlokalizowanych na terenie GOP i dodatkowo z ruin zamku w Mirowie (woj.częstochowskie). W wyniku analiz wykonanych za pomocą mikroanalizatora rentgenowskiego, uzupełnionych o wyniki badań mikroskopii polaryzacyjnej i rentgenografii w strefach przypowierzchniowych skał, stwierdzono obecność licznych soli, szczególnie siarczanów i chlorków, w mniejszych ilościach węglanów i soli złożonych . Na powierzchniach materiałów budowlanych zaobserwowano również silne zabrudzenia, złożone z sadzy i pyłów przemysłowych.
EN
The weathering of stone structural elements is caused several purposes, including natural and anthropogenic ones. Within the last mentioned, the air pollution is considered as the most serious one. Acid atmospheric precipitations have caused chemical corrosion: the increase of salts soluble contents in stone. Sandstone, limestone and eratic granite have been studied. Samples have been taken from four ancient buildings located in the Upper Silesia Industrial Region, and one in Częstochowa voivodeship - the ruins of the Mirów castle. Electron X-ray microanalysis were performed, supported by thin section microscopial and X-ray (DSH) analysis. In the weathering crusts some salts, especially sulfates and chlorides, in less degree carbonates and complex salts have been determined. The dark zones on the stones surface consists of soot and dust.
11
Content available remote Processes of coal fly ash weathering in waste deposits
72%
EN
In natural environment, where a long-term interaction of potentially toxic elements with surface water or groundwater systems may be of concern, ash can also be affected by weathering and certain secondary minerals can be formed. In weathering processes, the structure of fly-ash changes considerably which determines their physical and chemical properties. Simulating the weathering by the freeze-thaw test allows the changes occurring in ash particles structure to be produced. The experiment presented shows that ash solubility during a long period of time provides evidence that in the ash-water system, a variety of precipitation processes dominate the solubility of solid mass. The simulation of field conditions in laboratory research explains the behaviour of fly ash on deposits. It has been confirmed that weathering is the reason for a specific grain destruction. As a consequence, the grains are more reactive and more reaction products encircle the individual/single grain. The freeze-thaw test can be used as a helpful tool for predicting the behaviour of combustion by-product deposited on landfill, or temporal deposits and those subjected to weathering under natural conditions. The changes in ash particles observed on SEM images after 5 to 10 freeze-thaw cycles were comparable to those typical of ashes exposed to weathering during field test for a period not shorter than 12 months. The practical conclusion is that disposed fly ashes, taken from landfill site or store place for further application, are characterized by another peculiarity and therefore cannot uncritically be used for a partial replacement of cement in concrete or for other applications.
EN
In outdoor applications, all polymer materials weather which causes deterioration of their mechanical properties and has a negative influence on their appearance. In this article, the influence of UV irradiation and high temperature on polyamides PA6, PA6.6 and polypropylene PP and influence of aging parameters on their appearance (the state of surface) and chemical crystal structure have been shown. Microscopic examination of samples has shown that the biggest destruction in the surface of PP occurred in a short time after the beginning of the exposure. The examination of the surface and crystal structure of the materials clearly indicated that during exposure to UV irradiation and temperature degradation in PP materials occurred. Polyamides showed longer reaction time but after some time they also underwent radical changes in their supermolecular structure and they lost their esthetic appearance.
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